WorldWideScience

Sample records for bedding and linens

  1. 7 CFR 2902.15 - Bedding, bed linens, and towels.

    Science.gov (United States)

    2010-01-01

    ... PROCUREMENT Designated Items § 2902.15 Bedding, bed linens, and towels. (a) Definition. (1) Bedding is that... minimum biobased content is 12 percent and shall be based on the amount of qualifying biobased carbon in..., and silk are not qualifying biobased feedstocks for the purpose of determining the biobased content of...

  2. Cost containment in laundry and linen service.

    Science.gov (United States)

    Ellis, B

    1978-03-16

    One major problem looms among all others in the area of laundry and linen service, whether a hospital has an in-house operation, is part of a shared or central laundry, or uses a commercial service. That is the costly problem of controling linen consumption and replacement. A recent seminar offers some insight into reasons for the problem and some possible solutions.

  3. Evaluation of Whiteness in Linen and Semi-linen Fabrics

    Directory of Open Access Journals (Sweden)

    Liucina Kot

    2015-03-01

    Full Text Available Whiteness of textiles is one of the main "white" product quality indicators described by the following parameters: lightness of a colour, colour tone (white shade, white uniformity and stability under the influence of physical factors. “White” textile products can be perceived by comparing them with a white standard (Pantone colour palette. On the other hand, the whiteness of the fabric can be estimated using the colorimeter and determining lightness of a fabric L. The purpose of a research is to assess the whiteness of a linen and semi-linen fabric using two different methods, to carry out a comparative analysis of the results and to associate fabric whiteness with the fabric structure parameters. Two methods were used for experiment (colorimeter Spectraflash SF450X and expert assessment of whiteness. The analysed colours of a fabric were divided into five colours: white, whitish, light grey, grey and dark grey. The examination of the two methods, different results were obtained: testing with colorimeter, white colour was found in only one fabric, while the experts found the fabrics of white colour much more. The opinions of experts vary also. Fabric lightness L was associated with fabric structure parameters – the warp and weft settings and fabric weave. It was found that these fabric structure parameters affect the lightness of a colour of a fabric L very little.DOI: http://dx.doi.org/10.5755/j01.ms.21.1.5348

  4. Evaluation of Whiteness in Linen and Semi-linen Fabrics

    OpenAIRE

    Liucina Kot; Eglė KUMPIKAITĖ; Audronė RAGAIŠIENĖ; Žaneta RUKUIŽIENĖ

    2015-01-01

    Whiteness of textiles is one of the main "white" product quality indicators described by the following parameters: lightness of a colour, colour tone (white shade), white uniformity and stability under the influence of physical factors. “White” textile products can be perceived by comparing them with a white standard (Pantone colour palette). On the other hand, the whiteness of the fabric can be estimated using the colorimeter and determining lightness of a fabric L. The purpose of a research...

  5. Quality control in linen and laundry service at a tertiary care teaching hospital in India.

    Science.gov (United States)

    Singh, Dara; Qadri, Gj; Kotwal, Monica; Syed, At; Jan, Farooq

    2009-01-01

    The clean bedding and clean clothes installs psychological confidence in the patients and the public and enhances their faith in the services rendered by the hospital. Being an important Component in the management of the patients, a study was carried out to find out the current quality status and its conformity with the known standards and identify the areas of intervention in order to further increase the patient and staff satisfaction regarding the services provided by linen and laundry department Quality control practised in the Linen and Laundry Service was studied by conducting a prospective study on the concept of Donabedian model of structure, process and outcome. Study was done by pre-designed Proforma along with observation / Interviews / Questionnaire and study of records. The input studied included physical facilities, manpower, materials, equipments and environmental factors. The various elements of manpower studied consisted of number of staff working, their qualification, training, promotion avenues, motivation and job satisfaction. Process was studied by carrying out observations in linen and laundry service through a predesigned flow chart which was supplemented by interviews with different category of staff. Patient satisfaction, staff satisfaction and microbial count of laundered linen (quality dimensions) were studied in the outcome. The current study found that in spite of certain deficiencies in the equipment, manpower and process, the linen and laundry service is providing a satisfactory service to its users. However the services can be further improved by removing the present deficiencies both at structure and process level.

  6. 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.

  7. 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.

  8. 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

  9. 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...

  10. [Specialty specific reference values in linen use in public health and social service as a basis for determining laundry capacities].

    Science.gov (United States)

    Rietdorf, M; Häse, I

    1990-01-01

    The use of linen in health and social care should primarily be seen from a hygienic angle. Disproportions between the use of linen in the various fields of health care and the available laundry capacities have a negative hygienic and economic effect. Laundry capacities should, therefore, be calculated on the basis of specialty-specific guidevalues. The authors propose indicators suitable to this aim and present the results of a comprehensive analysis for the inpatient departments of internal medicine, surgery, urology, ophthalmology and otorhinolaryngology.

  11. 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.

  12. 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, ...

  13. Linen Fire as Biosorbent to Remove Heavy Metal Ions From Wastewater Modeling

    OpenAIRE

    Ildar G. Shaikhiev

    2014-01-01

    The possibility of using linen fires – lnopererabotk i waste as a sorption material for the extraction of heavy metal ions from wastewater modeling. It is shown that treatment with acid solutions linen fires a low concentration increases the surface area of linen fires and thus sorption capacity for heavy metal ions. The values of the maximum sorption capacity ions Fe (III), Co (II), Ni (II) and Zn (II) under static and dynamic conditions. IR spectroscopy...

  14. Bed Bugs and Schools

    Science.gov (United States)

    Bed bugs have long been a pest – feeding on blood, causing itchy bites and generally irritating their human hosts. They are successful hitchhikers, and can move from an infested site to furniture, bedding, baggage, boxes, and clothing.

  15. 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.

  16. Life and the laundromat: reflections on dirty linen and everyday private life.

    Science.gov (United States)

    Lawler, J

    1997-09-01

    This is a paper in which I reflect on, and draw issues from, an unplanned ethnographic experience in a London laundromat. The concept of 'everyday life' has a kind of simple, even benign, quality. However, there are many events in everyday life that are complex and complicating. Everyday life can be mundane--boring even. But it can also confront and trouble us, even when it concerns such apparently ordinary matters like doing the laundry. This paper is about how the ordinary matters of everyday life can become problematic and how our involvement in them can confront us with dilemmas that are unwanted yet require our attention and judgement as participants in social life.

  17. 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 Ca2+ 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. PMID:25969769

  18. 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.

  19. Karg S. (ed.) Flax (Linum usitatissimum L.) - a natural resource for food and textiles for 8000 years. Cross-disciplinary investigations on the evolution and cultural history of flax and linen. Programme and abstracts of the second workshop 28-30 June 2010 at Sonnerupgaard and in the Land

    DEFF Research Database (Denmark)

    Karg, Sabine

    2010-01-01

    Karg S. (ed.) Flax (Linum usitatissimum L.) - a natural resource for food and textiles for 8000 years. Cross-disciplinary investigations on the evolution and cultural history of flax and linen. Programme and abstracts of the second workshop 28-30 June 2010 at Sonnerupgaard and in the Land...

  20. 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.

  1. Karg, S. New projects within the FLAX Network. In: Karg S. (ed.) Flax (Linum usitatissimum L.) - a natural resource for food and textiles for 8000 years. Cross-disciplinary investigations on the evolution and cultural history of flax and linen. Programme and abstracts of the second

    DEFF Research Database (Denmark)

    Karg, Sabine

    2010-01-01

    Karg, S. New projects within the FLAX Network. In: Karg S. (ed.) Flax (Linum usitatissimum L.) - a natural resource for food and textiles for 8000 years. Cross-disciplinary investigations on the evolution and cultural history of flax and linen. Programme and abstracts of the second workshop 28...

  2. Flax (Linum usitatissimum L.) - a natural resource for food and textiles for 8000 years. Cross-disciplinary investigations on the evolution and cultural history of flax and linen. Programme and abstracts of the first workshop 24-26 November 2009 in the Carlsberg Academy Copenhagen, Denmark

    DEFF Research Database (Denmark)

    Karg, Sabine

    Flax (Linum usitatissimum L.) - a natural resource for food and textiles for 8000 years. Cross-disciplinary investigations on the evolution and cultural history of flax and linen. Programme and abstracts of the first workshop 24-26 November 2009 in the Carlsberg Academy Copenhagen, Denmark...

  3. Infant's bed climate and bedding in the Japanese home.

    Science.gov (United States)

    Nakamura Ikeda, Rie; Fukai, Kiyoko; Okamoto Mizuno, Kazue

    2012-06-01

    to assess the bed climate of infants in their homes in Japan. descriptive, exploratory, non-experimental research design. the data were collected at the participants' homes under normal circumstances. nineteen healthy infants between the ages of two and five months. Their mothers, who joined a parenting class organised by a maternity clinic in Okayama, Japan, consented to participate in this study. we visited the infants' homes and interviewed their mothers concerning the types and use of bedding. The temperature and relative humidity of the bed climate at the back and foot of the bedding, and in the room were measured every minute for four consecutive days. Differences among the bed climates measured during three seasons (spring, summer, and autumn) were assessed by one-way analysis of variance. The bed temperature was higher for infants than for adults. No significant difference in temperature was noted among the three seasons. The bed temperature was about 36.0°C when waterproof sheets and futon mattresses for children or adult were used. The average relative humidity of the bed climate at the back was highest in summer, followed by that in spring and autumn; the differences were significant. The use of waterproof sheets and futon mattresses for children in summer increased the relative humidity to 80% or more. The use of infant beds, sunoko drainboards, and cotton futon mattresses in summer was effective in reducing the bed humidity. these results suggest that nurse-midwives should advise the parents on comfortable bed climates for their infants, as well as how to select and use bedding for them. Copyright © 2010 Elsevier Ltd. All rights reserved.

  4. 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)

  5. 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

  6. Bed diameter effects and incipient slugging in gas fluidized beds

    International Nuclear Information System (INIS)

    Agarwal, P.K.

    1986-01-01

    The coalescence and growth of bubble swarms formed at the distributor of a fluidized bed gives rise to lateral as well as vertical distributions of bubble properties. However, existing models employ average bubble properties obtained largely from semi-empirical considerations. In a recent Paper, the author developed a bubble growth model based on a population balance approach. Analytical expressions were derived for the bubble characteristic distributions and averages. However, the model, developed for unconstrained growth, did not take into account the effect of the bed diameter and the possibility of slugging. In this Paper, the model is extended to take these aspects into account. A slugging criterion is also developed which is expected to be valid for the regime where incipient slugging depends on the bed height as well as the region where bed height does not significantly affect minimum slugging conditions

  7. Using multiple bed load measurements: Toward the identification of bed dilation and contraction in gravel-bed rivers

    Science.gov (United States)

    Marquis, G. A.; Roy, A. G.

    2012-02-01

    This study examines bed load transport processes in a small gravel-bed river (Béard Creek, Québec) using three complementary methods: bed elevation changes between successive floods, bed activity surveys using tags inserted into the bed, and bed load transport rates from bed load traps. The analysis of 20 flood events capable of mobilizing bed material led to the identification of divergent results among the methods. In particular, bed elevation changes were not consistent with the bed activity surveys. In many cases, bed elevation changes were significant (1 to 2 times the D50) even if the bed surface had not been activated during the flood, leading to the identification of processes of bed dilation and contraction that occurred over 10% to 40% of the bed surface. These dynamics of the river bed prevent accurate derivation of bed load transport rates from topographic changes, especially for low magnitude floods. This paper discusses the mechanisms that could explain the dilation and contraction of particles within the bed and their implications in fluvial dynamics. Bed contraction seems to be the result of the winnowing of the fine sediments under very low gravel transport. Bed dilation seems to occur on patches of the bed at the threshold of motion where various processes such as fine sediment infiltration lead to the maintenance of a larger sediment framework volume. Both processes are also influenced by flood history and the initial local bed state and in turn may have a significant impact on sediment transport and morphological changes in gravel-bed rivers.

  8. 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.

  9. 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.

  10. Method and apparatus for a combination moving bed thermal treatment reactor and moving bed filter

    Energy Technology Data Exchange (ETDEWEB)

    Badger, Phillip C.; Dunn, Jr., Kenneth J.

    2015-09-01

    A moving bed gasification/thermal treatment reactor includes a geometry in which moving bed reactor particles serve as both a moving bed filter and a heat carrier to provide thermal energy for thermal treatment reactions, such that the moving bed filter and the heat carrier are one and the same to remove solid particulates or droplets generated by thermal treatment processes or injected into the moving bed filter from other sources.

  11. 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

  12. 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.

  13. Debridement and wound bed preparation.

    Science.gov (United States)

    Falabella, Anna F

    2006-01-01

    Debridement can play a vital role in wound bed preparation and the removal of barriers that impair wound healing. In accordance with the TIME principles, debridement can help remove nonviable tissue, control inflammation or infection, decrease excess moisture, and stimulate a nonadvancing wound edge. There are many types of debridement, each with a set of advantages and disadvantages that must be clearly understood by the healthcare team. Failure to use the correct debridement method for a given type of wound may lead to further delays in healing, increase patient suffering, and unnecessarily increase the cost of care. This review article discusses the various methods of debridement, describes currently available debriding agents, evaluates the clinical data regarding their efficacy and safety, and describes strategies for the management of problematic nonhealing wounds.

  14. 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 Coal biosolubilisation was investigated in stirred tank reactor, fluidised bed and fixed bed bioreactors with a view to highlight the advantages and shortcomings of each of these reactor configurations. The stirred aerated bioreactor and fluidised...

  15. 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.

  16. Does bedding affect the airway and allergy?

    Science.gov (United States)

    Siebers, R W; Crane, J

    2011-04-01

    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.

  17. 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.

  18. Hydrodynamics of circulating and bubbling fluidized beds

    International Nuclear Information System (INIS)

    Gidaspow, D.P.; Tsuo, Y.P.; Ding, J.

    1991-01-01

    This paper reports that a review of modeling of the hydrodynamics of fluidization of bubbling beds showed that inviscid two-fluid models were able to predict a great deal of the behavior of bubbling beds because the dominant mechanism of energy dissipation is the drag between the particles and the fluid. The formation, the growth and the bursting of bubbles were predicted. Predicted wall-to-bed heat transfer coefficients and velocity profiles of jets agreed with measurements. Time average porosity distributions agreed with measurements done using gamma-ray densitometers without the use of any adjustable parameters. However, inviscid models could not correctly predict rates of erosion around tubes immersed into fluidized beds. To correctly model such behavior, granular stresses involving solids viscosity were added into the computer model. This viscosity arises due to random collision of particles. Several models fro this viscosity were investigated and the results compared to measurements of solids distributions in two-dimensional beds and to particle velocities reported in the literature. While in the case of bubbling beds the solids viscosity plays the role of a correction, modeling of a circulating fluidized bed (CFB) without a viscosity is not possible. Recent experimental data obtained at IIT and at IGT show that in CFB the solids viscous dissipation is responsible for as much as half of the pressure drop. From such measurement, solids viscosities were computed. These were used in the two fluid hydrodynamic model, to predict radial solids distributions and solids velocities which matched the experimental distributions. Most important, the model predicted cluster formation and transient internal circulation which is responsible for the favorable characteristics of CFBs, such as good wall-to-bed heat transfer. Video tape movies of computations compared favorably with high speed movies of the experiments

  19. Fluid bed dryer and Aeropep solidification system

    International Nuclear Information System (INIS)

    1975-01-01

    Performance measurements were made on the model of the Fluidized-bed Calciner developed by Aerojet Liquid Rocket Co. The measurements were made over the period August 11-19, 1975, at the Sacramento location of the calciner. The purpose of the tests was to evaluate the performance of the ALRC Fluidized Bed Concentrator for the processing of simulated waste containing realistic concentrations and chemical forms of radioiodine. (auth)

  20. 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.

  1. 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

  2. Synthetic bedding and wheeze in childhood.

    Science.gov (United States)

    Ponsonby, Anne-Louise; Dwyer, Terence; Kemp, Andrew; Cochrane, Jennifer; Couper, David; Carmichael, Allan

    2003-01-01

    The reasons for the increase in childhood asthma over time are unclear. The indoor environment is of particular concern. An adverse role for synthetic bedding on asthma development in childhood has been suggested by cross-sectional studies that have found an association between synthetic pillow use and childhood wheeze. Prospective data on infant bedding have not been available. Bedding data at 1 month of age were available from an infant survey for children who were participating in a 1995 follow-up study (N = 863; 78% traced). The 1995 follow-up was embedded in a larger cross-sectional survey involving 6,378 seven year olds in Tasmania (N = 92% of eligible). Outcome measures included respiratory symptoms as defined in the International Study of Asthma and Allergies in Childhood protocol. Frequent wheeze was defined as more than 12 wheeze episodes over the past year compared with no wheeze. Synthetic pillow use at 1 month of age was associated with frequent wheeze at age 7 (adjusted relative risk [aRR] = 2.5; 95% confidence interval [CI] = 1.2-5.5) independent of childhood exposure. Current synthetic pillow and quilt use was strongly associated with frequent wheeze (aRR = 5.2; CI = 1.3-20.6). Substantial trends were evident for an association of increasing number of synthetic bedding items with frequent wheeze and with increasing wheeze frequency. Among children with asthma, the age of onset of asthma occurred earlier if synthetic bedding was used in infancy. In this cohort, synthetic bedding was strongly and consistently associated with frequent childhood wheeze. The association did not appear to be attributable to bedding choice as part of an asthma management strategy.

  3. 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.

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

    International Nuclear Information System (INIS)

    Hansen, E. K.

    2015-01-01

    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.

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

    International Nuclear Information System (INIS)

    Gui, Nan; Yang, Xingtuan; Tu, Jiyuan; Jiang, Shengyao

    2014-01-01

    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

  6. Advection and dispersion of bed load tracers

    Science.gov (United States)

    Lajeunesse, Eric; Devauchelle, Olivier; James, François

    2018-05-01

    We use the erosion-deposition model introduced by Charru et al. (2004) to numerically simulate the evolution of a plume of bed load tracers entrained by a steady flow. In this model, the propagation of the plume results from the stochastic exchange of particles between the bed and the bed load layer. We find a transition between two asymptotic regimes. The tracers, initially at rest, are gradually set into motion by the flow. During this entrainment regime, the plume is strongly skewed in the direction of propagation and continuously accelerates while spreading nonlinearly. With time, the skewness of the plume eventually reaches a maximum value before decreasing. This marks the transition to an advection-diffusion regime in which the plume becomes increasingly symmetrical, spreads linearly, and advances at constant velocity. We analytically derive the expressions of the position, the variance, and the skewness of the plume and investigate their asymptotic regimes. Our model assumes steady state. In the field, however, bed load transport is intermittent. We show that the asymptotic regimes become insensitive to this intermittency when expressed in terms of the distance traveled by the plume. If this finding applies to the field, it might provide an estimate for the average bed load transport rate.

  7. 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.

  8. 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...

  9. A Study of the Linen and Laundry Control Procedures at the U.S. Air Force Medical Center, Wright-Patterson Air Force Base, Ohio.

    Science.gov (United States)

    1980-08-01

    effective accounting system for "tracking" of inventory and its ccsts is a very real requirement. S ecurity A matter of considerable concern should be...The Wash. Modern Nursing Home; March 1971. Danks , R.T. Automation For A New Central Laundry. Hospitals; J.A.TI.A.; 16 September 1971. Durham, R.C

  10. Bed Bugs

    Science.gov (United States)

    Prevent, identify, and treat bed bug infestations using EPA’s step-by-step guides, based on IPM principles. Find pesticides approved for bed bug control, check out the information clearinghouse, and dispel bed bug myths.

  11. 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

  12. Bed Load Variability and Morphology of Gravel Bed Rivers Subject to Unsteady Flow: A Laboratory Investigation

    Science.gov (United States)

    Redolfi, M.; Bertoldi, W.; Tubino, M.; Welber, M.

    2018-02-01

    Measurement and estimation of bed load transport in gravel bed rivers are highly affected by its temporal fluctuations. Such variability is primarily driven by the flow regime but is also associated with a variety of inherent channel processes, such as flow turbulence, grain entrainment, and bed forms migration. These internal and external controls often act at comparable time scales, and are therefore difficult to disentangle, thus hindering the study of bed load variability under unsteady flow regime. In this paper, we report on laboratory experiments performed in a large, mobile bed flume where typical hydromorphological conditions of gravel bed rivers were reproduced. Data from a large number of replicated runs, including triangular and square-wave hydrographs, were used to build a statistically sound description of sediment transport processes. We found that the inherent variability of bed load flux strongly depends on the sampling interval, and it is significantly higher in complex, wandering or braided channels. This variability can be filtered out by computing the mean response over the experimental replicates, which allows us to highlight two distinctive phenomena: (i) an overshooting (undershooting) response of the mean bed load flux to a sudden increase (decrease) of discharge, and (ii) a clockwise hysteresis in the sediment rating curve. We then provide an interpretation of these findings through a conceptual mathematical model, showing how both phenomena are associated with a lagging morphological adaptation to unsteady flow. Overall, this work provides basic information for evaluating, monitoring, and managing gravel transport in morphologically active rivers.

  13. 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.

  14. 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

  15. Theoretical comparison of packed bed and fluidized bed membrane reactors for methane reforming

    NARCIS (Netherlands)

    Gallucci, F.; van Sint Annaland, M.; Kuipers, J.A.M.

    2010-01-01

    In this theoretical work the performance of different membrane reactor concepts, both fluidized bed and packed bed membrane reactors, has been compared for ultra-pure hydrogen production via methane reforming. Using detailed theoretical models, the required membrane area to reach a given conversion

  16. Comparison of packed bed and fluidized bed membrane reactors for methane reforming

    NARCIS (Netherlands)

    Gallucci, F.; van Sint Annaland, M.; Kuipers, J.A.M.

    2009-01-01

    In this work the performance of different membrane reactor concepts, both fluidized bed and packed bed membrane reactors, have been compared for the reforming of methane for the production of ultra-pure hydrogen. Using detailed theoretical models, the required membrane area to reach a given

  17. Incipient motion of gravel and coal beds

    Indian Academy of Sciences (India)

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

    2. 1Department of Civil Engineering, Indian Institute of Technology, ... the particle size distribution curve following the relationship by Christensen .... where f = friction factor, ρ = mass density of fluid, and V = mean velocity of flow. .... for the incipient motion of gravel and coal beds have been represented by simple empirical.

  18. Response of bed mobility to sediment supply in natural gravel bed channels: A detailed examination and evaluation of mobility parameters

    Science.gov (United States)

    T. E. Lisle; J. M. Nelson; B. L. Barkett; J. Pitlick; M. A. Madej

    1998-01-01

    Recent laboratory experiments have shown that bed mobility in gravel bed channels responds to changes in sediment supply, but detailed examinations of this adjustment in natural channels have been lacking, and practical methodologies to measure bed mobility have not been tested. We examined six gravel-bed, alternate-bar channels which have a wide range in annual...

  19. A System Approach to Navy Medical Education and Training. Appendix 30. Curriculum for General Hospital Corpsman.

    Science.gov (United States)

    1974-08-31

    individual patient needs; e.g., blind, bedridden , post ierative Make an unoccupied (standing) bed 340037 Change linens; e.g., bed, examination table...males, common in elderly people and alcoholics; excessive physical exertion in environment with high humidity and temperature, and cessation of sweating...drainage system with/without suction 150046 Arrange room/unit for individual patient’s needs, e.g., blind, bedridden , postoperative 250025 Read

  20. 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.

  1. Investigation of heat transfer in bed and freeboard of fluidized bed combustors

    International Nuclear Information System (INIS)

    Mitor, V.V.; Matsnev, V.V.; Sorokin, A.P.

    1986-01-01

    Experimental results for heat transfer between immersed bundles of bare tubes and fluidized beds are reported. The experimental results are obtained on industrial boilers with a bed area from 2,5 to 4 m/sup 2/ under conditions of long term operation. The bed temperature range has been 1073 0 K-1233 0 K, gas velocity between 1,8-4,5 m/s, mean particle size from 1,5 mm to 6,0 mm, freeboard furnace height of 2,3 and 5 m. The obtained data are compared with experimental results from literature

  2. 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

  3. 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.

  4. FBR and RBR particle bed space reactors

    International Nuclear Information System (INIS)

    Powell, J.R.; Botts, T.E.

    1983-01-01

    Compact, high-performance nuclear reactor designs based on High-Temperature Gas Reactors (HTGRs) particulate fuel are investigated. The large surface area available with the small-diameter (approx. 500 microns) particulate fuel allows very high power densities (MW's/liter), small temperature differences between fuel and coolant (approx. 10 0 K), high coolant-outlet temperatures (1500 to 3000 0 K, depending on design), and fast reactor startup (approx. 2 to 3 seconds). Two reactor concepts are developed - the Fixed Bed Reactor (FBR), where the fuel particles are packed into a thin annular bed between two porous cylindrical drums, and the Rotating Bed Reactor (RBR), where the fuel particles are held inside a cold rotating (typically approx. 500 rpm) porous cylindrical drum. The FBR can operate steady-state in the closed-cycle He-cooled mode or in the open-cycle H 2 -cooled mode. The RBR will operate only in the open-cycle H 2 -cooled mode

  5. 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...

  6. 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.

  7. "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.

  8. Thermal-hydraulic and characteristic models for packed debris beds

    International Nuclear Information System (INIS)

    Mueller, G.E.; Sozer, A.

    1986-12-01

    APRIL is a mechanistic core-wide meltdown and debris relocation computer code for Boiling Water Reactor (BWR) severe accident analyses. The capabilities of the code continue to be increased by the improvement of existing models. This report contains information on theory and models for degraded core packed debris beds. The models, when incorporated into APRIL, will provide new and improved capabilities in predicting BWR debris bed coolability characteristics. These models will allow for a more mechanistic treatment in calculating temperatures in the fluid and solid phases in the debris bed, in determining debris bed dryout, debris bed quenching from either top-flooding or bottom-flooding, single and two-phase pressure drops across the debris bed, debris bed porosity, and in finding the minimum fluidization mass velocity. The inclusion of these models in a debris bed computer module will permit a more accurate prediction of the coolability characteristics of the debris bed and therefore reduce some of the uncertainties in assessing the severe accident characteristics for BWR application. Some of the debris bed theoretical models have been used to develop a FORTRAN 77 subroutine module called DEBRIS. DEBRIS is a driver program that calls other subroutines to analyze the thermal characteristics of a packed debris bed. Fortran 77 listings of each subroutine are provided in the appendix

  9. Staged fluidized-bed combustion and filter system

    International Nuclear Information System (INIS)

    Mei, J.S.; Halow, J.S.

    1994-01-01

    A staged fluidized-bed combustion and filter system are described for substantially reducing the quantity of waste through the complete combustion into ash-type solids and gaseous products. The device has two fluidized-bed portions, the first primarily as a combustor/pyrolyzer bed, and the second as a combustor/filter bed. The two portions each have internal baffles to define stages so that material moving therein as fluidized beds travel in an extended route through those stages. Fluidization and movement is achieved by the introduction of gases into each stage through a directional nozzle. Gases produced in the combustor/pyrolyzer bed are permitted to travel into corresponding stages of the combustor/filter bed through screen filters that permit gas flow but inhibit solids flow. Any catalyst used in the combustor/filter bed is recycled. The two beds share a common wall to minimize total volume of the system. A slightly modified embodiment can be used for hot gas desulfurization and sorbent regeneration. Either side-by-side rectangular beds or concentric beds can be used. The system is particularly suited to the processing of radioactive and chemically hazardous waste. 10 figures

  10. 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.

  11. 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.)

  12. Biodegradation of phenolic waste liquors in stirred-tank, packed-bed, and fluidized-bed bioreactors

    Energy Technology Data Exchange (ETDEWEB)

    Holladay, D W; Hancher, G W; Chilcote, D D; Scott, C D

    1978-11-01

    The biological degradation of phenolic scrub liquors similar to those that arise in coal conversion processes was studied for symbiotic bacterial populations contained in a continuously stirred tank bioreactor, a three-phase packed-bed bioreactor, and a three-phase, fluidized-bed bioreactor. The conversions of phenol compounds were comparable in the three-phase, packed-bed bioreactor and the continuously stirred tank bioreactor; however, the packed-bed bioreactor degradation rates were as much as twice those in the continuously stirred tank bioreactor, and packed-bed bioreactor retention times were as low as one- tenth those of the continuously stirred tank bioreactors (minimum time was 12 hours).

  13. 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.

  14. 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)

  15. 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

  16. Bed occupancy monitoring: data processing and clinician user interface design.

    Science.gov (United States)

    Pouliot, Melanie; Joshi, Vilas; Goubran, Rafik; Knoefel, Frank

    2012-01-01

    Unobtrusive and continuous monitoring of patients, especially at their place of residence, is becoming a significant part of the healthcare model. A variety of sensors are being used to monitor different patient conditions. Bed occupancy monitoring provides clinicians a quantitative measure of bed entry/exit patterns and may provide information relating to sleep quality. This paper presents a bed occupancy monitoring system using a bed pressure mat sensor. A clinical trial was performed involving 8 patients to collect bed occupancy data. The trial period for each patient ranged from 5-10 weeks. This data was analyzed using a participatory design methodology incorporating clinician feedback to obtain bed occupancy parameters. The parameters extracted include the number of bed exits per night, the bed exit weekly average (including minimum and maximum), the time of day of a particular exit, and the amount of uninterrupted bed occupancy per night. The design of a clinical user interface plays a significant role in the acceptance of such patient monitoring systems by clinicians. The clinician user interface proposed in this paper was designed to be intuitive, easy to navigate and not cause information overload. An iterative design methodology was used for the interface design. The interface design is extendible to incorporate data from multiple sensors. This allows the interface to be part of a comprehensive remote patient monitoring system.

  17. A note on acoustic measurements of turbulence, suspended sediment, and bed forms in mobile bed experiments

    Science.gov (United States)

    One of the challenges of hydraulic experimentation is designing experiments that are complex enough to capture relevant processes while retaining the simplicity necessary for useful, accurate measurements. The intricacy of the interactions between turbulent flows and mobile beds in rivers and stream...

  18. Anoxic environments and oil source bed genesis

    Energy Technology Data Exchange (ETDEWEB)

    Demaison, G J [Chevron Overseas Petroleum Inc., San Francisco, CA; Moore, G T

    1980-01-01

    The anoxic, aquatic, environment is a mass of water so depleted in oxygen that virtually all aerobic biological activity has ceased. Anoxic conditions occur where the demand for oxygen in the water column exceeds the supply. The specific cause for preferential lipid enrichment probably relates to the biochemistry of anaerobic bacterial activity. Recent evidence suggests that ancient organic-rich sediments containing hydrogen-rich kerogens (potential oil source beds) were deposited in similar anoxic environments. We propose the following classification for modern aquatic anoxic settings: (1) Large anoxic lakes - Permanent stratification promotes development of anoxic bottom water, particularly in large, deep lakes, which are not subject to seasonal overturn, e.g., Lake Tanganyika. (2) Anoxic silled basins - Landlocked silled basins with positive water balance tend to become anoxic. Typical are the Baltic and Black Seas. In arid region seas (Red and Mediterranean Seas), evaporation exceeds river inflow, causing negative water balance and well-aerated, nutrient-depleted bottom waters. (3) Anoxic layers caused by upwelling - Develop only when the oxygen supply in deep water cannot match demand by decaying organisms. Examples are the Benguela current and Peru coastal upwelling. (4) Open ocean anoxic layers - Found at intermediate depths in the northeastern Pacific and northern Indian Oceans; due to distance from deep, oxygenated polar water sources. Analogous to world-wide anoxic events at times of global climatic warm-ups and major transgressions, as in late Jurassic and middle Cretaceous time. Petroleum exploration can be greatly assisted by using geochemistry to identify paleo-anoxic events in the stratigraphic record. Recognition of the proposed anoxic models in ancient sedimentary basins should help in regional mapping of oil shales and oil-source beds. 17 figures.

  19. 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

  20. 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

  1. 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

  2. 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

  3. 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.

  4. Use of bed nets and factors that influence bed net use among Jinuo Ethnic Minority in southern China.

    Science.gov (United States)

    Xu, Jian-wei; Liao, Yuan-mei; Liu, Hui; Nie, Ren-hua; Havumaki, Joshua

    2014-01-01

    Insecticide-treated nets (ITNs) are an integral part of vector control recommendations for malaria elimination in China. This study investigated the extent to which bed nets were used and which factors influence bed net use among Jinuo Ethnic Minority in China-Myanmar-Laos border areas. This study combined a quantitative household questionnaire survey and qualitative semi-structured in-depth interviews (SDI). Questionnaires were administered to 352 heads of households. SDIs were given to 20 key informants. The bed net to person ratio was 1∶2.1 (i.e., nearly one net for every two people), however only 169 (48.0%) households owned at least one net and 623 (47.2%) residents slept under bed nets the prior night. The percentages of residents who regularly slept under nets (RSUN) and slept under nets the prior night (SUNPN) were similar (48.0% vs. 47.2%, P>0.05), however the percentage correct use of nets (CUN) was significantly lower (34.5%, Pcash income per person (ACIP) was an independent factor that influenced bed net use (PHigh bed net availability does not necessarily mean higher coverage or bed net use. Household income, house type and knowledge of the ability of bed nets to prevent malaria are all independent factors that influence bed net use among Jinuo Ethnic Minority.

  5. China Pakistan Economic Corridor (CPEC): Challenges and the Way Forward

    Science.gov (United States)

    2017-06-01

    Report-30.pdf. 21 2001.105 The agreements included cooperation in tourism , economic, and technical initiatives; a lease on the Saindak gold and...access to cotton, bed linens, agricultural produce, marble, sporting goods, and raw materials from Pakistan and provided Pakistan with access to...will help boost the tourism sector as 185 Nazir, “Macro and Micro Dividends of CPEC.” 186 Esteban

  6. Bedding material affects mechanical thresholds, heat thresholds and texture preference

    Science.gov (United States)

    Moehring, Francie; O’Hara, Crystal L.; Stucky, Cheryl L.

    2015-01-01

    It has long been known that the bedding type animals are housed on can affect breeding behavior and cage environment. Yet little is known about its effects on evoked behavior responses or non-reflexive behaviors. C57BL/6 mice were housed for two weeks on one of five bedding types: Aspen Sani Chips® (standard bedding for our institute), ALPHA-Dri®, Cellu-Dri™, Pure-o’Cel™ or TEK-Fresh. Mice housed on Aspen exhibited the lowest (most sensitive) mechanical thresholds while those on TEK-Fresh exhibited 3-fold higher thresholds. While bedding type had no effect on responses to punctate or dynamic light touch stimuli, TEK-Fresh housed animals exhibited greater responsiveness in a noxious needle assay, than those housed on the other bedding types. Heat sensitivity was also affected by bedding as animals housed on Aspen exhibited the shortest (most sensitive) latencies to withdrawal whereas those housed on TEK-Fresh had the longest (least sensitive) latencies to response. Slight differences between bedding types were also seen in a moderate cold temperature preference assay. A modified tactile conditioned place preference chamber assay revealed that animals preferred TEK-Fresh to Aspen bedding. Bedding type had no effect in a non-reflexive wheel running assay. In both acute (two day) and chronic (5 week) inflammation induced by injection of Complete Freund’s Adjuvant in the hindpaw, mechanical thresholds were reduced in all groups regardless of bedding type, but TEK-Fresh and Pure-o’Cel™ groups exhibited a greater dynamic range between controls and inflamed cohorts than Aspen housed mice. PMID:26456764

  7. 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

  8. 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...

  9. Statistical description of flume experiments on mixed-size bed-load transport and bed armoring processes

    Science.gov (United States)

    Chen, D.; Zhang, Y.

    2008-12-01

    The objective of this paper is to describe the statistical properties of experiments on non-uniform bed-load transport as well as the mechanism of bed armoring processes. Despite substantial effort made over the last two decades, the ability to compute the bed-load flux in a turbulent system remains poor. The major obstacles include the poor understanding of the formation of armor lays on bed surfaces. Such a layer is much flow-resistible than the underlying material and therefore significantly inhibits sediment transport from the reach. To study the problem, we conducted a flume study for mixed sand/gravel sediments. We observed that aggregated sediment blocks were the most common characters in armor layers - the largest sizes resist hydraulic forces, while the smaller sizes add interlocking support and prevent loss of fine material through gaps between the larger particles. Fractional transport rates with the existing of armor layers were measured with time by sediment trapping method at the end of flume. To address the intermittent and time-varying behavior of bed-load transport during bed armoring processes, we investigated the probability distribution of the fractional bed-load transport rates, and the underlying dynamic model derived from the continuous time random walk framework. Results indicate that it is critical to consider the impact of armor layers when a flow is sufficient to move some of the finer particles and yet insufficient to move all the larger particles on a channel bed.

  10. 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...

  11. Wall-to-bed heat transfer in gas-solid fluidized beds: a computational and experimental study

    NARCIS (Netherlands)

    Patil, D.J.; Smit, J.; van Sint Annaland, M.; Kuipers, J.A.M.

    2006-01-01

    The wall-to-bed heat transfer in gas-solid fluidized beds is mainly determined by phenomena prevailing in a thermal boundary layer with a thickness in the order of magnitude of the size of a single particle. In this thermal boundary layer the temperature gradients are very steep and the local

  12. [Patient-related color preference and color design in the hospital].

    Science.gov (United States)

    Schuschke, G; Christiansen, H

    1994-06-01

    Colour-physiological studies involving volunteers and colour-psychological interviewing of patients with varied diagnoses revealed that, currently, no compelling scientific reasons can be given for coloration in the hospital. Interviewing 68 patients from a number of clinics on the coloration of sick-rooms yielded the following preferred colours, irrespective of the patients' classing into groups by various criteria: Light colours were consistently preferred for all objects such as ceiling, walls, floor, curtains, furniture, and bed linen. It should be emphasized that even white was a desirable colour for ceilings and bed linen. Beige was found to rank first for walls, floors, curtains, and furniture, whereas the colours of wood and grey shared the second rank for floors and furniture. Green and pink ranked second for bed linen. White and green ranked second for walls and curtains, respectively. In view of the heterogeneity, the findings may not be converted into an absolute just as the recommendations by other workers. Still, the patients' wish should be given priority over decreed recommendations by experts when basic considerations of illumination (reflectance!) are allowed for in the particular overall colour design project.

  13. 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 ...

  14. Endotoxin, coliform, and dust levels in various types of rodent bedding.

    Science.gov (United States)

    Whiteside, Tanya E; Thigpen, Julius E; Kissling, Grace E; Grant, Mary G; Forsythe, Diane

    2010-03-01

    Endotoxins in grain dust, household dust, and animal bedding may induce respiratory symptoms in rodents and humans. We assayed the endotoxin, coliform, and dust levels in 20 types of rodent bedding. Endotoxin concentrations were measured by using a commercial test kit, coliform counts were determined by using conventional microbiologic procedures, and dust content was evaluated by using a rotating-tapping shaker. Paper bedding types contained significantly less endotoxin than did other bedding types; the highest levels of endotoxin were detected in hardwood and corncob beddings. The range of endotoxin content for each bedding type was: corncob bedding, 1913 to 4504 endotoxin units per gram (EU/g); hardwood bedding, 3121 to 5401 EU/g; corncob-paper mixed bedding, 1586 to 2416 EU/g; and paper bedding, less than 5 to 105 EU/g. Coliform counts varied from less than 10 to 7591 cfu/g in corncob beddings, 90 to 4010 cfu/g in corncob-paper mixed beddings, less than 10 to 137 cfu/g in hardwood beddings, and less than 10 cfu/g in paper beddings. Average dust content was less than 0.15% in all commercial bedding types. We conclude that paper bedding is the optimal bedding type for conducting LPS inhalation studies and that rodent bedding containing high levels of endotoxin may alter the results of respiratory and immunologic studies in rodents.

  15. Prevention and Control of Bed Bugs in Residences

    Science.gov (United States)

    ... in other rooms, including bathrooms, living rooms and laundry rooms. Look for spots or smears Dark blood ... having the inspection done by a pest control service provider (exterminator). If you find a bed bug, ...

  16. 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

  17. Limestone fragmentation and attrition during fluidized bed oxyfiring

    Energy Technology Data Exchange (ETDEWEB)

    Fabrizio Scala; Piero Salatino [Istituto di Ricerche sulla Combustione - CNR, Napoli (Italy)

    2010-04-15

    Attrition/fragmentation of limestone under simulated fluidized bed oxyfiring conditions was investigated by means of an experimental protocol that had been previously developed for characterization of attrition/fragmentation of sorbents in air-blown atmospheric fluidized bed combustors. The protocol was based on the use of different and mutually complementary techniques. The extent and pattern of attrition by surface wear in the dense phase of a fluidized bed were assessed in experiments carried out with a bench scale fluidized bed combustor under simulated oxyfiring conditions. Sorbent samples generated during simulated oxyfiring tests were further characterized from the standpoint of fragmentation upon high velocity impact by means of a purposely designed particle impactor. Results showed that under calcination-hindered conditions attrition and fragmentation patterns are much different from those occurring under air-blown atmospheric combustion conditions. Noteworthy, attrition/fragmentation enhanced particle sulfation by continuously regenerating the exposed particle surface. 13 refs., 8 figs.

  18. Temperature distribution in spouted bed and heat transfer

    International Nuclear Information System (INIS)

    Takeda, Hiroshi; Yamamoto, Yutaka

    1976-01-01

    Temperature distribution in spouted bed was measured by using brass and graphite spouted beds so as to investigate heat transfer characteristic of spouted bed applied to an apparatus of PyC coating. These spouted beds are batch type and are spouted by air or nitrogen gas of room temperature, and the outer wall of beds are heated by nichrome or graphite heater. Particles used for experiments are alumina spherical particles and the diameter is 0.80 -- 1.12 mm. Temperature condition is in the range of 400 -- 1,400 0 C. In the neighborhood of 400 0 C, the spouting condition is stable, while the spouting condition becomes unstable in the case of above 1,000 0 C. This is caused by abrupt temperature increase of spouting gas. It was found that heat transfer coefficient h sub(w) of our low temperature experiments was closer to the calculated from Malek et al.'s equation, h sub(p) of our experiments was several times greater than the calculated from Uemaki et al.'s equation. On the other hand, h sub(p) of high temperature experiments was compared with an experimental relation for convective heat transfer of fluidized bed, it was found that Nu sub(p) of our experiments was nearly equal to or greater than the calculated from the relation, this would be caused by radiant heat transfer. (auth.)

  19. 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

  20. 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...

  1. Acidification of calf bedding reduces fly development and bacterial abundance.

    Science.gov (United States)

    Calvo, M S; Gerry, A C; McGarvey, J A; Armitage, T L; Mitloehner, F M

    2010-03-01

    Environmental stressors, such as high fly density, can affect calf well-being. Sodium bisulfate (SBS) is an acidifier that reduces the pH of flooring and bedding, creating a medium that neither bacteria nor immature flies (also known as larvae or maggots) can thrive in. Two experiments were conducted to investigate the application of SBS to a mixture of rice hull calf bedding and calf slurry (BED) to reduce house fly (Musca domestica L.) larval density and the abundance of bacteria. In experiment 1, dish pans containing 1L of BED and 3,000 house fly eggs were treated with SBS at concentrations of 0, 8.9, 17.7, and 26.5g of SBS/0.05m(2) of BED (CON, LOW, MED, and HIGH, respectively), with each SBS concentration applied to 4 individual pans (16 pans total). Reapplication of the same SBS concentrations in each pan occurred 3 times/wk throughout the 23-d trial. Larval house fly survival was significantly reduced in all pans with SBS relative to CON pans, with lowest survival rates in the MED and HIGH pans (99% and 100% reduction, respectively). The mean pH for each treatment was inversely related to the SBS concentration. In experiment 2, pans containing 1L of BED and 3,000 house fly eggs were treated with either 0g of SBS (CON), 8.9g of SBS/0.05m(2) of BED with reapplication of the acidifier 3 times/wk (SB3x), or 8.9g of SBS/0.05m(2) of BED applied only once at 48h before the end of the 8 d-trial (SB48). Larval house fly survival and bacterial concentrations were reduced (90% larval reduction and 68% bacterial reduction) in the SB3x treatment relative to the CON. Mean pH was also reduced in SB3x pans relative to CON or SB48 pans. Overall, acidification of calf BED using the acidifier SBS resulted in a reduction of bacteria and house fly larval survival. This form of fly control might be expected to reduce adult fly production and, therefore, fly-related stress in calves.

  2. 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....

  3. HE3 outgassing from four working palladium and uranium beds

    International Nuclear Information System (INIS)

    Souers, P. C.; Coronado, P. R.; Fearon, F. M.; Garza, R. G.; Shaw , J. F.; Stump, R. K.; Tsugawa, R. T.

    1988-01-01

    The He 3 output from two palladium and two uranium beds storing T 2 and D-T was studied as a function of time. Three of the beds were started new and watched for a year; the fourth bed was twelve years old. All four were beds used in routine tritium handling. Initial stoichiometries were PdT/sub 0.3/ and UT/sub 0.7/ so that both operated at similar 1 to 130 kPa pressures. The He 3 from palladium ranged from the 0.002 mo1% lower level of sensitivity to 0.01% for PdT 2 at one year of age. The UT system showed 0.1% He 3 at 4 to 62 days and 0.1 to 10% at longer times, with the first cuts being high in He 3 . The palladium bed with 95 to 97% pure T 2 enriches the output to as high as 97 to 99%. 9 refs., 1 fig., 2 tabs

  4. Theory and measurements of electrophoretic effects in monolith, fixed-bed, and fluidized-bed plasma reactors

    International Nuclear Information System (INIS)

    Morin, T.J.

    1989-01-01

    Pressure gradients and secondary flow fields generated by the passage of electrical current in a d.c. gas discharge or gas laser are topics of longstanding interest in the gaseous electronics literature. These hydrodynamic effects of space charge fields and charged particle density gradients have been principally exploited in the development of gas separation and purification processes. In recent characterization studies of fixed-bed and fluidized-bed plasma reactors several anomalous flow features have been observed. These reactors involve the contacting of a high-frequency, resonantly-sustained, disperse gas discharge with granular solids in a fixed or fluidized bed. Anomalies in the measured pressure drops and fluidization velocities have motivated the development of an appropriate theoretical approach to, and some additional experimental investigations of electrophoretic effects in disperse gas discharges. In this paper, a theory which includes the effects of space charge and diffusion is used to estimate the electric field and charged particle density profiles. These profiles are then used to calculate velocity fields and gas flow rates for monolith, fixed-bed, and fluidized-bed reactors. These results are used to rationalize measurements of gas flow rates and axial pressure gradients in high-frequency disperse gas discharges with and without an additional d.c. axial electric field

  5. Potential health impacts of burning coal beds and waste banks

    Science.gov (United States)

    Finkelman, R.B.

    2004-01-01

    Uncontrolled release of pollutants from burning coal beds and waste banks presents potential environmental and human health hazards. On a global scale, the emissions of large volumes of greenhouse gases from burning coal beds may contribute to climate change that alters ecosystems and patterns of disease occurrence. On regional and local scales, the emissions from burning coal beds and waste banks of acidic gases, particulates, organic compounds, and trace elements can contribute to a range of respiratory and other human health problems. Although there are few published reports of health problems caused by these emissions, the potential for problems can be significant. In India, large numbers of people have been displaced from their homes because of health problems caused by emissions from burning coal beds. Volatile elements such as arsenic, fluorine, mercury, and selenium are commonly enriched in coal deposits. Burning coal beds can volatilize these elements, which then can be inhaled, or adsorbed on crops and foods, taken up by livestock or bioaccumulated in birds and fish. Some of these elements can condense on dust particles that can be inhaled or ingested. In addition, selenium, arsenic, lead, tin, bismuth, fluorine, and other elements condense where the hot gaseous emissions come in contact with ambient air, forming mats of concentrated efflorescent minerals on the surface of the ground. These mats can be leached by rainwater and washed into local water bodies providing other potential routes of exposure. Although there are little data linking burning coal beds and waste banks to known health problems, a possibly analogous situation exists in rural China where mineralized coal burned in a residential environment has caused widespread and severe health problems such as fluorosis and arseniasis. ?? 2004 Elsevier B.V. All rights reserved.

  6. Modeling and Simulation of a lab-scale Fluidised Bed

    Directory of Open Access Journals (Sweden)

    Britt Halvorsen

    2002-04-01

    Full Text Available The flow behaviour of a lab-scale fluidised bed with a central jet has been simulated. The study has been performed with an in-house computational fluid dynamics (CFD model named FLOTRACS-MP-3D. The CFD model is based on a multi-fluid Eulerian description of the phases, where the kinetic theory for granular flow forms the basis for turbulence modelling of the solid phases. A two-dimensional Cartesian co-ordinate system is used to describe the geometry. This paper discusses whether bubble formation and bed height are influenced by coefficient of restitution, drag model and number of solid phases. Measurements of the same fluidised bed with a digital video camera are performed. Computational results are compared with the experimental results, and the discrepancies are discussed.

  7. Odorous volatile organic compounds, Escherichia coli, and nutrient concentrations when kiln-dried pine chips and corn stover bedding are used in beef bedded manure packs

    Science.gov (United States)

    Pine (Pinus spp.) bedding has been shown to lower the concentration of odorous volatile organic compounds (VOCs) and pathogenic bacteria compared with corn (Zea mays L.) stover bedding, but availability and cost limit the use of pine bedding in cattle confinement facilities. The objectives of this s...

  8. 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.

  9. 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

  10. Baby Boomers and Beds: a Demographic Challenge for the Ages.

    Science.gov (United States)

    Song, Zirui; Ferris, Timothy G

    2018-03-01

    The United States is facing a significant demographic transition, with about 10,000 baby boomers turning age 65 each day. At the same time, the nation is experiencing a similarly striking transition in hospital capacity, as the supply of hospital beds has declined in recent decades. The juxtaposition of population aging and hospital capacity portends a potentially widening divergence between supply and demand for hospital care. We provide a closer look at current hospital capacity and a rethinking of the future role of hospital beds in meeting the needs of an aging population.

  11. Numerical Simulations of the Effects of a Tidal Turbine Array on Near-Bed Velocity and Local Bed Shear Stress

    Directory of Open Access Journals (Sweden)

    Philip A. Gillibrand

    2016-10-01

    Full Text Available We apply a three-dimensional hydrodynamic model to consider the potential effects of energy extraction by an array of tidal turbines on the ambient near-bed velocity field and local bed shear stress in a coastal channel with strong tidal currents. Local bed shear stress plays a key role in local sediment dynamics. The model solves the Reynold-averaged Navier-Stokes (RANS equations on an unstructured mesh using mixed finite element and finite volume techniques. Tidal turbines are represented through an additional form drag in the momentum balance equation, with the thrust imparted and power generated by the turbines being velocity dependent with appropriate cut-in and cut-out velocities. Arrays of 1, 4 and 57 tidal turbines, each of 1.5 MW capacity, were simulated. Effects due to a single turbine and an array of four turbines were negligible. The main effect of the array of 57 turbines was to cause a shift in position of the jet through the tidal channel, as the flow was diverted around the tidal array. The net effect of this shift was to increase near-bed velocities and bed shear stress along the northern perimeter of the array by up to 0.8 m·s−1 and 5 Pa respectively. Within the array and directly downstream, near-bed velocities and bed shear stress were reduced by similar amounts. Changes of this magnitude have the potential to modify the known sand and shell banks in the region. Continued monitoring of the sediment distributions in the region will provide a valuable dataset on the impacts of tidal energy extraction on local sediment dynamics. Finally, the mean power generated per turbine is shown to decrease as the turbine array increased in size.

  12. 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...

  13. Petrology and geochemistry of samples from bed-contact zones in Tunnel Bed 5, U12g-Tunnel, Nevada Test Site

    International Nuclear Information System (INIS)

    Connolly, J.R.; Keil, K.; Mansker, W.L.; Allen, C.C.; Husler, J.; Lowy, R.; Fortney, D.R.; Lappin, A.R.

    1984-10-01

    This report summarizes the detailed geologic characterization of samples of bed-contact zones and surrounding nonwelded bedded tuffs, both within Tunnel Bed 5, that are exposed in the G-Tunnel complex beneath Rainier Mesa on the Nevada Test Site (NTS). Original planning studies treated the bed-contact zones in Tunnel Bed 5 as simple planar surfaces of relatively high permeability. Detailed characterization, however, indicates that these zones have a finite thickness, are depositional in origin, vary considerably over short vertical and horizontal distances, and are internally complex. Fluid flow in a sequence of nonwelded zeolitized ash-flow or bedded tuffs and thin intervening reworked zones appears to be a porous-medium phenomenon, regardless of the presence of layering. There are no consistent differences in either bulk composition or detailed mineralogy between bedded tuffs and bed-contact zones in Tunnel Bed 5. Although the original bulk composition of Tunnel Bed 5 was probably peralkaline, extensive zeolitization has resulted in a present peraluminous bulk composition of both bedded tuffs and bed-contact zones. The major zeolite present, clinoptilolite, is intermediate (Ca:K:Na = 26:35:39) and effectively uniform in composition. This composition is similar to that of clinoptilolite from the tuffaceous beds of Calico Hills above the static water level in hole USW G-1, but somewhat different from that reported for zeolites from below the static water level in USW G-2. Tunnel Bed 5 also contains abundant hydrous manganese oxides. The similarity in composition of the clinoptilolites from Tunnel Bed 5 and those above the static water level at Yucca Mountain indicates that many of the results of nuclide-migration experiments in Tunnel Bed 5 would be transferrable to zeolitized nonwelded tuffs above the static water level at Yucca Mountain

  14. 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

  15. Characterization of the extremely arsenic-resistant Brevibacterium linens strain AE038-8 isolated from contaminated groundwater in Tucumán, Argentina

    Science.gov (United States)

    Maizel, Daniela; Blum, Jodi S.; Ferrero, Marcela A.; Utturkar, Sagar M.; Brown, Steven D.; Rosen, Barry P.; Oremland, Ronald S.

    2015-01-01

    Brevibacterium linens AE038-8, isolated from As-contaminated groundwater in Tucumán (Argentina), is highly resistant to arsenic oxyanions, being able to tolerate up to 1 M As(V) and 75 mM As(III) in a complex medium. Strain AE038-8 was also able to reduce As(V) to As(III) when grown in complex medium but paradoxically it could not do this in a defined minimal medium with sodium acetate and ammonium sulfate as carbon and nitrogen sources, respectively. No oxidation of As(III) to As(V) was observed under any conditions. Three copies of the ars operon comprising arsenic resistance genes were found on B. linens AE038-8 genome. In addition to the well known arsC, ACR3 andarsR, two copies of the arsO gene of unknown function were detected.

  16. Aerobic exercise deconditioning and countermeasures during bed rest.

    Science.gov (United States)

    Lee, Stuart M C; Moore, Alan D; Everett, Meghan E; Stenger, Michael B; Platts, Steven H

    2010-01-01

    Bed rest is a well-accepted model for spaceflight in which the physiologic adaptations, particularly in the cardiovascular system, are studied and potential countermeasures can be tested. Bed rest without countermeasures results in reduced aerobic capacity and altered submaximal exercise responses. Aerobic endurance and factors which may impact prolonged exercise, however, have not been well studied. The initial loss of aerobic capacity is rapid, occurring in parallel with the loss of plasma volume. Thereafter, the reduction in maximal aerobic capacity proceeds more slowly and is influenced by central and peripheral adaptation. Exercise capacity can be maintained during bed rest and may be improved during recovery with appropriate countermeasures. Plasma volume restoration, resistive exercise, orthostatic stress, aerobic exercise, and aerobic exercise plus orthostatic stress all have been tested with varying levels of success. However, the optimal combination of elements-exercise modality, intensity, duration, muscle groups exercised and frequency of aerobic exercise, orthostatic stress, and supplementary resistive or anaerobic exercise training-has not been systematically evaluated. Currently, frequent (at least 3 days per week) bouts of intense exercise (interval-style and near maximal) with orthostatic stress appears to be the most efficacious method to protect aerobic capacity during bed rest. Further refinement of protocols and countermeasure hardware may be necessary to insure the success of countermeasures in the unique environment of space.

  17. 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)

  18. Model for boiling and dryout in particle beds

    International Nuclear Information System (INIS)

    Lipinski, R.J.

    1982-06-01

    Over the last ten years experiments and modeling of dryout in particle beds have produced over fifty papers. Considering only volume-heated beds, over 250 dryout measurements have been made, and are listed in this work. In addition, fifteen models to predict dryout have been produced and are discussed. A model is developed in this report for one-dimensional boiling and dryout in a porous medium. It is based on conservation laws for mass, momentum, and energy. The initial coupled differential equations are reduced to a single first-order differential equation with an algebraic equation for the upper boundary condition. The model includes the effects of both laminar and turbulent flow, two-phase friction, and capillary force. The boundary condition at the bed bottom includes the possibility of inflowing liquid and either an adiabatic or a bottom-cooled support structure. The top of the bed may be either channeled or subcooled. In the first case the channel length and the saturation at the base of the channels are predicted. In the latter case, a criterion for penetration of the subcooled zone by channels is obtained

  19. Scheduling admissions and reducing variation in bed demand

    NARCIS (Netherlands)

    Bekker, R.; Out, P.

    2011-01-01

    Variability in admissions and lengths of stay inherently leads to variability in bed occupancy. The aim of this paper is to analyse the impact of these sources of variability on the required amount of capacity and to determine admission quota for scheduled admissions to regulate the occupancy

  20. Impact and Your Death Bed: Playing the Long Game

    Science.gov (United States)

    Goldhaber, Dan

    2018-01-01

    Educational researchers want to engage in, or with, research that matters--research that helps education institutions improve the academic and life outcomes of students. This essay is about whether education research matters for students. The author defines "death-bed impact" as the direct line between education research and student…

  1. Developing and evaluating a meeting assistant test bed

    NARCIS (Netherlands)

    Post, W.M.; Lincoln, M.

    2008-01-01

    A test bed has been developed in which participants are tasked to work in simulated, scenario based, projects in which face-to-face and remote meetings of about 45 minutes have to be held. Measures on performance, team factors and remote aspects are automatically collected with electronic

  2. 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.

  3. Numerical modelling of river processes: flow and river bed deformation

    NARCIS (Netherlands)

    Tassi, P.A.

    2007-01-01

    The morphology of alluvial river channels is a consequence of complex interaction among a number of constituent physical processes, such as flow, sediment transport and river bed deformation. This is, an alluvial river channel is formed from its own sediment. From time to time, alluvial river

  4. 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

  5. Use of tanning beds and incidence of skin cancer.

    Science.gov (United States)

    Zhang, Mingfeng; Qureshi, Abrar A; Geller, Alan C; Frazier, Lindsay; Hunter, David J; Han, Jiali

    2012-05-10

    We sought to evaluate the risk effect of tanning bed use on skin cancers among teenage and young adults. We also expected to determine whether a dose-response relationship was evident. We observed 73,494 female nurses for 20 years (from 1989 to 2009) in a large and well-characterized cohort in the United States and investigated whether frequency of tanning bed use during high school/college and at ages 25 to 35 years were associated with a risk of basal cell carcinoma (BCC), squamous cell carcinoma (SCC), and melanoma. We used Cox proportional hazards models and carefully adjusted for host risk factors, ultraviolet index of residence, and sun exposure behaviors at a young age. During follow-up, 5,506 nurses were diagnosed with BCC, 403 with SCC, and 349 with melanoma. The multivariable-adjusted hazard ratio (HR) of skin cancer for an incremental increase in use of tanning beds of four times per year during both periods was 1.15 (95% CI, 1.11 to 1.19; P tanning bed use at ages 25 to 35 years, we found a significantly higher risk of BCC for use during high school/college (multivariable-adjusted HR for use more than six times per year compared with no use was 1.73 during high school/college v 1.28 at ages 25 to 35 years; P for heterogeneity tanning bed use and the risk of skin cancers, especially BCC, and the association is stronger for patients with a younger age at exposure.

  6. 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.

  7. 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...

  8. Modelling of thermal and mechanical behaviour of pebble beds

    International Nuclear Information System (INIS)

    Boccaccini, L.V.; Buehler, L.; Hermsmeyer, S.; Wolf, F.

    2001-01-01

    FZK (Forshungzentrum Karlsruhe) is developing a Helium Cooled Pebble Bed (HCPB) Blanket Concept for fusion power reactors based on the use of ceramic breeder materials and beryllium multiplier in the form of pebble beds. The design of such a blanket requires models and computer codes describing the thermal-mechanical behavior of pebble beds to evaluate the temperatures, stresses, deformations and mechanical interactions between pebble beds and the structure with required accuracy and reliability. The objective to describe the beginning of life condition for the HCPB blanket seems near to be reached. Mechanical models that describe the thermo-mechanical behavior of granular materials used in form of pebble beds are implemented in a commercial structure code. These models have been calibrated using the results of a large series of dedicated experiments. The modeling work is practically concluded for ceramic breeder; it will be carried on in the next year for beryllium to obtain the required correlations for creep and the thermal conductivity. The difficulties for application in large components (such as the HCPB blanket) are the limitations of the present commercial codes to manage such a set of constitutive equations under complex load conditions and large mesh number. The further objective is to model the thermal cycles during operation; the present correlations have to be adapted for the release phase. A complete description of the blanket behavior during irradiation is at the present out of our capability; this objective requires an extensive R and D program that at the present is only at the beginning. (Y.Tanaka)

  9. 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

  10. 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

  11. Mass and heat transfer between a fluidized bed and a freely moving submerged sphere

    NARCIS (Netherlands)

    Prins, W.; Valk, M.

    1995-01-01

    For fluidized bed combustion and gasification of solid fuels, but also for various other fluidized bed processes such as drying, granulation and evaporation, mass and heat transport to (or from) a particle freely moving in the fluidized bed is of great importance. The combustion rate of a

  12. 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.

  13. 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.

  14. Effects of near-bed turbulence and micro-topography on macroinvertebrate movements across contrasting gravel-bed surfaces (Invited)

    Science.gov (United States)

    Buffin-Belanger, T. K.; Rice, S. P.; Reid, I.; Lancaster, J.

    2009-12-01

    Fluvial habitats can be described from a series of physical variables but to adequately address the habitat quality it becomes necessary to develop an understanding that combines the physical variables with the behaviour of the inhabitating organisms. The hypothesis of flow refugia provide a rational that can explain the persistence of macroinvertebrate communities in gravel-bed rivers when spates occur. The movement behaviour of macroinvertebrates is a key element to the flow refugia hypothesis, but little is known about how local near-bed turbulence and bed microtopography may affect macroinvertebrate movements. We reproduced natural gravel-bed substrates with contrasting gravel bed textures in a large flume where we were able to document the movement behaviour of the cased caddisfly Potamophylax latipennis for a specific discharge. The crawling paths and drift events of animals were analysed from video recordings. Characteristics of movements differ from one substrate to another. The crawling speed is higher for the small grain-size substrates but the mean travel distance remains approximately the same between substrates. For each substrate, the animals tended to follow consistent paths across the surface. The number of drift events and mean distance drifted is higher for the small grain-size substrate. ADV measurements close to the boundary allow detailed characterisation of near-bed hydraulic variables, including : skewness coefficients, TKE, UV correlation coefficients and integral time scales from autocorrelation analysis. For these variables, the vertical patterns of turbulence parameters are similar between the substrates but the amplitude of the average values and standard errors vary significantly. The spatial distribution of this variability is considered in relation to the crawling paths. It appears that the animals tend to crawl within areas of the substrate where low flow velocities and low turbulent kinetic energies are found, while sites that

  15. 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...

  16. 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.

  17. Does bedding promote pine survival and growth on ditched wet sands?

    Science.gov (United States)

    Ralph A. Klawitter

    1970-01-01

    Results from a study of prepared beds for planting slash pine on a wet sandy flat in Florida were inconclusive. Early growth was improved, but survival was not; and differences between a bedded site and an unbedded site were slight.

  18. 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.

  19. 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.

    period, the bottom currents pull sediment (sand) particles supplied by major and minor rivers, rolling along the Gulf bed. These sediments perhaps participate in the formation of bed form structures. The topography of the Gulf bottom comprises of numerous...

  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. Chemical characteristics of beddings for swine: effects of bedding depths and of addition of inoculums in a pilot-scale.

    Science.gov (United States)

    Corrêa, E K; Corezzolla, J L; Corrêa, M N; Bianchi, I; Gil-Turnes, C; Lucia, T

    2012-11-01

    The effect of depths and of addition of inoculums on the chemical content of swine beddings was evaluated. For beddings 0.25m (25D) and 0.50m (50D) deep, three treatments were tested in two repeats with the same beddings: control (no inoculums); T1 (250g of Bacillus cereus var. toyoii at 8.4×10(7)CFU/g); and T2 (250g of a pool of Bacillus sp. at 8.4×10(7)CFU/g) (250g for 25D and 500g for 50D). For 25D, the C:N ratio was lower, but N, K and C contents were greater than for 50D (P0.05). In the second repeat, beddings presented lower C:N ratio and greater N, P and K contents than in the first repeat (P<0.05). Thus, the compost produced after using 25D twice had greater fertilizer value than that of 50D. Copyright © 2012 Elsevier Ltd. All rights reserved.

  2. Comparisons of housing, bedding, and cooling options for dairy calves.

    Science.gov (United States)

    Hill, T M; Bateman, H G; Aldrich, J M; Schlotterbeck, R L

    2011-04-01

    Housing, bedding, and summer cooling were management options evaluated. Holstein calves (42±2 kg of body weight) initially 2 to 5 d of age were managed in southwest Ohio in poly hutches or wire mesh pens in a curtain-sided nursery with no supplemental heat. Calves were fed milk replacer (27% crude protein, 17% fat fed at 0.657 kg of dry matter per calf daily), starter (20% crude protein dry matter, textured, fed free-choice), and water (free-choice). Measurements were for 56 d. In trial 1, 28 calves per treatment were bedded with straw and housed in either hutches or nursery pens. This trial was conducted from September to March; the average temperature was 8°C and ranged from -17 to 31°C. In trial 2a, 16 calves per treatment were managed in nursery pens bedded with straw, in nursery pens bedded with sand, or in hutches bedded with sand. This trial was conducted from May to September; the average temperature was 21°C and ranged from 7 to 33°C. In trial 2b, 26 calves per treatment were housed in nursery pens and bedded with straw. This trial was conducted from May to September; the average temperature was 22°C and ranged from 8 to 34°C. One treatment was cooled with fans between 0800 and 1700 h and the other was not. Data were analyzed as repeated measures in a completely randomized block design by trial, with calf as the experimental unit. In trial 3, air in the nursery and calf hutches used above was sampled 35 d apart for calves aged 5 and 40 d. Air in individual hutches on 2 commercial farms was sampled for 5- and 40-d-old calves for 2 hutch types. Air in the multi-calf hutches was sampled for calves of 75 and 110 d of age. Bacterial concentrations of air samples were analyzed (log10) as odds ratios by Proc Logistic in SAS software (SAS Institute Inc., Cary, NC); differences were declared at Pbedding were greater and scouring was less than that in calves bedded with sand in the nursery or hutches. The relative humidity was greater in the hutches than in

  3. [Skin care and prevention of bed sores in bedridden patients].

    Science.gov (United States)

    Martínez Cuervo, Fernando; Soldevilla Agreda, J Javier; Verdú Soriano, José; Segovia Gómez, Teresa; García Fernández, Francisco Pedro; Pancorbo Hidalgo, Pedro Luís

    2007-12-01

    The aging process and environmental aggressions will leave their imprints on the state of a person's skin, possibly compromising some of its functions. Age is a risk factor for the development of bed sores, but not the only factor nor the most important one; therefore, we need to develop prevention programs directed to all patients who spend long periods of time sedentary or bedridden. Prevention programs for bed sores must be based on the best evidence available and include a risk evaluation on these factors: suffering a lesion due to pressure, specific skin treatment, incontinence control, excessive humidity posture changes and the use of special surfaces to manage pressure during an increase in mobility or activity by the patient, local pressure reducing devices as well as paying attention to special situations. All of these care measures have to be developed based on a continuity of treatment among the institutions and caretakers involved with treating each patient.

  4. Recipient Wound Bed Characteristics Affect Scarring and Skin Graft Contraction

    Science.gov (United States)

    2015-02-13

    wound debridement followed by coverage with split thickness skin grafts (STSGs). As a consequence, skin replacement therapy has been a topic of intense...number. 1. REPORT DATE 13 FEB 2015 2. REPORT TYPE N/A 3. DATES COVERED - 4. TITLE AND SUBTITLE Recipient wound bed characteristics affect...E), Verhoeff’s Elas- tic Masson’s Tricrhome for total collagen and elastin, or picrosirius red for differential detection of Type I and III collagen

  5. Role of vision and mechanoreception in bed bug, Cimex lectularius L. behavior.

    Directory of Open Access Journals (Sweden)

    Narinderpal Singh

    Full Text Available The role of olfactory cues such as carbon dioxide, pheromones, and kairomones in bed bug, Cimex lectularius L. behavior has been demonstrated. However, the role of vision and mechanoreception in bed bug behavior is poorly understood. We investigated bed bug vision by determining their responses to different colors, vertical objects, and their ability to detect colors and vertical objects under low and complete dark conditions. Results show black and red paper harborages are preferred compared to yellow, green, blue, and white harborages. A bed bug trapping device with a black or red exterior surface was significantly more attractive to bed bugs than that with a white exterior surface. Bed bugs exhibited strong orientation behavior toward vertical objects. The height (15 vs. 30 cm tall and color (brown vs. black of the vertical object had no significant effect on orientation behavior of bed bugs. Bed bugs could differentiate color and detect vertical objects at very low background light conditions, but not in complete darkness. Bed bug preference to different substrate textures (mechanoreception was also explored. Bed bugs preferred dyed tape compared to painted tape, textured painted plastic, and felt. These results revealed that substrate color, presence of vertical objects, and substrate texture affect host-seeking and harborage-searching behavior of bed bugs. Bed bugs may use a combination of vision, mechanoreception, and chemoreception to locate hosts and seek harborages.

  6. Fluidized bed and pulverized coal combustion residues for secondary pavements

    International Nuclear Information System (INIS)

    Ghafoori, N.; Diawara, H.; Wang, L.

    2009-01-01

    The United States produced nearly 125 million tons of coal combustion products in 2006. These by-products include fly ash, flue gas desulphurization materials, bottom ash, boiler slag, and other power plant by-products. The expense associated with waste disposal, lack of disposal sites, and significant environmental damage linked with the disposal of coal combustion residues have encouraged innovative utilization strategies such as the fluidized bed combustion (FBC) unit. This paper presented the results of a laboratory investigation that examined the properties of composites developed with different proportions of pre-conditioned FBC spent bed, pulverized coal combustion fly ash, natural fine aggregate, and Portland cement. The purpose of the study was to examine the extent to which the by-product composites could replace currently used materials in secondary roads. The paper presented the research objectives and experimental programs, including matrix constituent and proportions; mixture proportions; and mixing, curing, sampling, and testing. The discussion of results centered around compressive strength and expansion by internal sulfate attack. It was concluded that with proper proportioning, by-products of pulverized and fluidized bed combustion promote binding of sand particles and provide adequate strength under various curing and moisture conditions 4 refs., 6 tabs.

  7. 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

  8. The upper pennsylvanian pittsburgh coal bed: Resources and mine models

    Science.gov (United States)

    Watson, W.D.; Ruppert, L.F.; Tewalt, S.J.; Bragg, L.J.

    2001-01-01

    The U.S. Geological Survey recently completed a digital coal resource assessment model of the Upper Pennsylvanian Pittsburgh coal bed, which indicates that after subtracting minedout coal, 16 billion short tons (14 billion tonnes) remain of the original 34 billion short tons (31 billion tonnes) of coal. When technical, environmental, and social restrictions are applied to the remaining Pittsburgh coal model, only 12 billion short tons (11 billion tonnes) are available for mining. Our assessment models estimate that up to 0.61 billion short tons (0.55 billion tonnes), 2.7 billion short tons (2.4 billion tonnes), and 8.5 billion short tons (7.7 billion tonnes) could be available for surface mining, continuous mining, and longwall mining, respectively. This analysis is an example of a second-generation regional coal availability study designed to model recoverability characteristics for all the major coal beds in the United States. ?? 2001 International Association for Mathematical Geology.

  9. The bedding environment, sleep position, and frequent wheeze in childhood.

    Science.gov (United States)

    Ponsonby, Anne-Louise; Dwyer, Terence; Trevillian, Leigh; Kemp, Andrew; Cochrane, Jennifer; Couper, David; Carmichael, Allan

    2004-05-01

    Synthetic quilt use has been associated with increased childhood wheeze in previous studies. Our aim was to examine whether the adverse effect of synthetic quilt use on frequent wheeze differed by usual sleep position. A population-based cross-sectional study of 6378 (92% of those eligible) 7-year-olds in Tasmania, Australia, was conducted in 1995. Exercise-challenge lung function was obtained on a subset of 414 children from randomly selected schools. Child bedding including pillow and overbedding composition and usual sleep position by parental questionnaire. Frequent wheeze (>12 wheeze episodes over the past year), using the International Study of Asthma and Allergies in Childhood parental questionnaire, and baseline and postexercise forced expiratory volume in 1 second lung-function measures. Frequent wheeze (n = 117) was positively associated with synthetic quilts, synthetic pillows, electric blankets, and sleeping in a bottom bunk bed but did not vary by sleep position. In a nested case-control analysis, the association between synthetic quilt use and frequent wheeze differed by sleep position. Among children who slept supine, synthetic (versus feather) quilt use was associated with frequent wheeze (adjusted odds ratio: 2.37 [1.08, 5.23]). However, among nonsupine sleepers, overlying synthetic quilt use was not associated with frequent wheeze (adjusted odds ratio: 1.06 [0.60, 1.88]). This difference in quilt effect by sleep position was highly significant. Similarly, synthetic quilt use was associated with lower postexercise forced expiratory volume in 1 second measures among supine but not nonsupine sleeping children. An increasing focus on the bedding environment immediately adjacent to the nose and mouth is required for respiratory disorders provoked by bedding, such as child asthma characterized by frequent wheeze.

  10. 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

  11. 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.

  12. The Bulgarian coal and the fluid bed technology

    International Nuclear Information System (INIS)

    Konstantinov, M.; Georgiev, J.; Lebedov, K.; Petrov, N.

    2000-01-01

    Because of low-quality of the most of Bulgarian coal and more rigorous ecological restrictions for decreasing of greenhouse gases the fluidized bed technology is the most appropriate combustion technology. A study with a pilot plant aiming to establish the values of technological parameters in view to maintain stable process of fluidized bed combustion at the specific burning characteristics of the Bulgarian coal was carried out. Coal of different quality and particle size production of 'Marbas' LTD mines were used. Series of experiments with batches of strictly determined content were carried out at minimal, average and maximal load. The technological factors as: layer's aerodynamics, layer's height, fuel's quantity and quantity of inert material were changed at each batch. The ecological factors were optimized considering coal's quality, plant's parameters, limestone's dosing and layer's aerodynamics. A regressive model for optimization of technological and ecological factors was created. An average coefficient of performance was achieved, resp. 82.27 % at combustion of coal from mines 'Maritsa-West' and 90 % from mine 'Lev'. A coefficient of sulfur oxides' capture 70 % was obtained at coal with sulfur content 3.1-3.9 %. In conclusion the fluidized bed technology is very suitable for combustion's characteristics of the Bulgarian coal

  13. 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...

  14. 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 ru...

  15. 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

  16. Self-Esteem and Emotional Intelligence among B.Ed Trainees of Tsunami Affected Coastal Belt

    Science.gov (United States)

    Babu M, Sameer

    2008-01-01

    Through this study the author investigates the relationship between self-esteem and emotional intelligence among B.Ed trainees of Tsunami affected coastal belt of Alappey district of Kerala, India. Stream of study, marital status and age based comparisons were made among the B.Ed trainees. 92 B.Ed trainees were the participants in the study. It…

  17. 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

  18. Thermal hydraulic and neutronic interaction in the rotating bed reactor

    International Nuclear Information System (INIS)

    Lee, C.C.

    1986-01-01

    Power transient characteristics in a rotating fluidized bed reactor (RBR) are investigated theoretically. A propellant flow perturbation is assumed to occur in an initially equilibrium state of the core. Transfer functions representing quasi-one-dimensional mutual feedback between thermal hydraulics and neutronics are developed and analyzed in the frequency domain. Neutronic responses are determined by Fermi-age theory for slowing down of fast neutrons and diffusion theory for thermal neutron distribution. Neutron leakage through the exhaust nozzle is accounted for by applying diffuse view factors similar to those applied in radiative heat transfer. The bed expansion behavior is described by a kinematic wave equation derived from the continuity of the gas phase. The drift flux approach is used to determine the yield fractions in the equilibrium bed. Thermal responses of fuel are evaluated by dividing it into several volume-averaged zones to better account for the transient effects over single zone models. Sample calculations are undertaken for the various operation conditions and design parameters of the RBR based on 250 MW/sub t/, 1000 MW/sub t/, and 5000 MW/sub t/ power reactors. The results show that power transients are dependent on the parametric changes of optical thickness and view factors

  19. Flow and fracture in water-saturated, unconstrained granular beds

    Directory of Open Access Journals (Sweden)

    Germán eVaras

    2015-06-01

    Full Text Available The injection of gas in a liquid-saturated granular bed gives rise to a wide variety of invasion patterns. Many studies have focused on constrained porous media, in which the grains are fixed in the bed and only the interstitial fluid flows when the gas invades the system. With a free upper boundary, however, the grains can be entrained by the ascending gas or fluid motion, and the competition between the upward motion of grains and sedimentation leads to new patterns. We propose a brief review of the experimental investigation of the dynamics of air rising through a water-saturated, unconstrained granular bed, in both two and three dimensions. After describing the invasion pattern at short and long time, a tentative regime-diagram is proposed. We report original results showing a dependence of the fluidized zone shape, at long times, on the injection flow rate and grain size. A method based on image analysis makes it possible to detect not only the fluidized zone profile in the stationary regime, but also to follow the transient dynamics of its formation. Finally, we describe the degassing dynamics inside the fluidized zone, in the stationary regime. Depending on the experimental conditions, regular bubbling, continuous degassing, intermittent regime or even spontaneous flow-to-fracture transition are observed.

  20. Coal bed methane: current status and outlook - Panorama 2008

    International Nuclear Information System (INIS)

    2008-01-01

    In many parts of the world, there is growing interest in coal bed methane (CBM), which has been exploited for years in the United States. One reason is undoubtedly that some new gas producing countries, including India and China, are seeking to limit the level of their gas dependence. Another is the need to control greenhouse gas emissions, especially using mechanisms set up under the Kyoto Protocol. Finally, the increase in gas prices on international markets also encourages this trend

  1. Bed Bugs Appearance and Life Cycle

    Science.gov (United States)

    Identify these bugs accurately, from egg to nymph to adult. Adults are about the size of an apple seed, brown and oval-shaped, and either flat or balloon-like depending on how recently fed. Nymphs are a bit smaller and translucent or whitish yellow.

  2. Firing in fluid beds and burners

    Energy Technology Data Exchange (ETDEWEB)

    Frandsen, F.; Lans, R. van der; Storm Pedersen, L.; Philbert Nielsen, H.; Aslaug Hansen, L.; Lin, W.; Johnsson, J.E.; Dam-Johansen, K.

    1998-02-01

    An investigation of the effect of co-firing straw and pulverized coal was performed. Based on experiments from pilot-scale and full-scale it was concluded that a higher fraction of straw in the fuel feedstock mixture results in lower NO and SO{sub 2} emissions. The lower NO emission was mainly due to the higher volatile content of the straw, which leads to lower stoichiometry in the gas phase and in subsequent suppression of NO{sub x} formation. This conclusion is consistent with experimental and modeling results for pure coal combustion. The effect of coal quality on NO emissions has been investigated with three coals of different characteristics in three furnaces: in the Funen power station, unit 7 (FVO7), the Midtkraft Studstrup power station, unit 4 (MKS4), and the Mitsui Babcock Energy Ltd (MBEL) test-rig. The MBEL test-rig was able to reproduce qualitatively the emissions from the MKS4 plant, and quantitatively the emissions from the FVO7 plant. The better agreement between the MBEL test-rig and FVO7 is presumed to be related to the existence of a large primary zone with a relatively low stoichiometry, diminishing the influence of near burner air and fuel mixing rate on the NO emissions. An engineering model has been developed for the prediction of NO emissions and burnout from pulverized fuel combustion in swirl burners. A simplified model for reduction of N{sub 2}O in CFBC has been developed, and simulation results are in good agreement with experimental data from a 12 MW{sub th} CFB-boiler. (EG) EFP-94. 108 refs.

  3. Development and Design of Sludge Freezing Beds

    Science.gov (United States)

    1988-12-01

    Wastewater Treatment/Disposal/Reuse. New York: McGraw Hill, 2nd ed. Morin, W., R. Lewandowski and R. Zaloum (1986) Le traitement des boues a l’aide du gel...degel naturel et epandage des boues en foret. Draft report for Environment Canada, Mon- treal. National Oceanic and Atmospheric Administration (1984

  4. Bed Rest and Orthostatic-Hypotensive Intolerance

    Science.gov (United States)

    Schneider, Suzanne M.

    2000-01-01

    Orthostatic tolerance may be defined as the ability of humans to maintain cerebral perfusion and consciousness upon movement from a supine or sitting position to the upright posture; for example, subjects can stand suddenly or be tilted to the head-up body position. Similar but not identical physiological responses can be induced by positive G(sub Z) (head to foot) acceleration or exposure to lower body negative pressure (LBNP). The objective is to suddenly shift blood to the lower body to determine how effectively cardiovascular and neural-hormonal compensatory responses react to maintain blood pressure. In the most precise method for measuring tolerance, individuals would be stressed until they faint (syncope). However, the potential consequences and discomforts of such a test usually prohibit such a procedure so that few investigators actually induce syncope. In a more common approach, subjects are exposed to a given level of stress, for example, head-up tilt for 15 min, and any increases in heart rate or decreases in blood pressure are interpreted as indicators of progress toward syncope. Presumably, the greater the perturbation of heart rate and blood pressure, the closer to "tolerance," i.e., point of unconsciousness. Another more appropriate approach is to induce a progressively increasing hypotensive stress until pre-determined physiological responses or pre-syncopal symptoms appear. The physiological criteria may include a sudden drop in systolic blood pressure (greater than 25 mm/min), a sudden drop in heart rate (greater than 15 beats/min), or a systolic blood pressure less than 70 mmHg. The most common pre-syncopal symptoms include lightheadedness, stomach awareness or distress, feelings of warmth, tingly skin, and light to profuse sweating. Usually a combination of physiological responses and symptoms occurs such that, on different days, the tolerance time to the same orthostatic protocol is reproducible for a given individual. The assumption is that

  5. 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

  6. Use of soft hydrothermal processing to improve and recycle bedding for laboratory animals.

    Science.gov (United States)

    Miyamoto, T; Li, Z; Kibushi, T; Yamasaki, N; Kasai, N

    2008-10-01

    Cage bedding for laboratory rodents can influence animal wellbeing and thus the experimental data. In addition, a large amount of used bedding containing excrement is discharged as medical waste from life science institutes and breeding companies. We developed a ground-breaking system to improve fresh bedding and recycle used bedding by applying a soft hydrothermal process with high-temperature and high-pressure dry steam. The system removes both harmful organic components and aromatic hydrocarbons that can affect animals' metabolism. The purpose of the present study was to evaluate the chemical and physical properties of the improved fresh bedding and the recycled used bedding treated by the system. The results showed that 68-99% of the predominant aromatic hydrocarbons were removed from fresh bedding treated at 0.35 MPa and 140 degrees C for 120 min ('improved bedding'). In addition, 59.4-99.0% of predominant harmful organic compounds derived from excrement were removed from used bedding treated at 0.45 MPa and 150 degrees C for 60 min ('recycled bedding'). The soft hydrothermal treatment increased the number of acidic functional groups on the bedding surface and gave it the high adsorptive efficiency of ammonia gas. Harmful substances such as microorganisms, heavy metals and pesticides decreased below the detection limit. The results clearly showed that the improved and recycled bedding is safer for laboratory rodents and has the potential to ameliorate conditions in primary and secondary enclosures (e.g. cages and animal rooms) used for maintaining laboratory animals. This process may be one of the most advanced techniques in providing an alternative to softwood and other bedding, economizing through the recycling of used bedding and reducing bedding waste from animal facilities.

  7. Effect of a powered drive on pushing and pulling forces when transporting bariatric hospital beds.

    Science.gov (United States)

    Wiggermann, Neal

    2017-01-01

    Powered drives designed to assist with moving hospital beds are commercially available but no studies have evaluated whether they reduce the push and pull forces likely contributing to injury in caregivers. This study measured hand forces of 10 caregivers maneuvering a manual and powered bariatric bed through simulated hospital environments (hallway, elevator, and ramp). Peak push and pull forces exceeded previously established psychophysical limits for all activities with the manual bed. For the powered bed, peak forces were significantly (p pushing did not differ between beds. Powered drive may reduce the risk of injury or the number of caregivers needed for transport. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. 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.

  9. 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.

  10. Accuracy of determining the elements for occurrence of beds and curvature of well according to measurement data by the apparatus of a bed tiltmeter NID-1

    Energy Technology Data Exchange (ETDEWEB)

    Krivonosov, R.I.; Karabel' nikova, G.N.; Khatuntsev, V.G.; Salov, Ye.A.

    1979-01-01

    Questions are examined of the accuracy of determining elements for occurrence of beds and curvature of wells using data of measurement by apparatus of a bed tiltmeter NID-1. Calculated formulas and graphs are presented for different conditions of occurrence of a bed, angle of inclination of the well and its diameter. The presented data make it possible to have a differentiated approach to evaluating the results of incline measurement.

  11. Comparison of the Effects of Fluidized-Bed and Fixed-Bed Reactors in Microwave-Assisted Catalytic Decomposition of TCE by Hydrogen

    Directory of Open Access Journals (Sweden)

    Lili Ren

    2012-01-01

    Full Text Available Trichloroethylene (TCE decomposition by hydrogen with microwave heating under different reaction systems was investigated. The activities of a series of catalysts for microwave-assisted TCE hydrodechlorination were tested through the fixed-bed and the fluidized-bed reactor systems. This study found that the different reaction system is suitable for different catalyst type. And there is an interactive relationship between the catalyst type and the reaction bed type.

  12. 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

  13. Modeling N2O Reduction and Decomposition in a Circulating Fluidized bed Boiler

    DEFF Research Database (Denmark)

    Johnsson, Jan Erik; Åmand, Lars-Erik; Dam-Johansen, Kim

    1996-01-01

    The N2O concentration was measured in a circulating fluidized bed boiler of commercial size. Kinetics for N2O reduction by char and catalytic reduction and decomposition over bed material from the combustor were determined in a laboratory fixed bed reactor. The destruction rate of N2O in the comb......The N2O concentration was measured in a circulating fluidized bed boiler of commercial size. Kinetics for N2O reduction by char and catalytic reduction and decomposition over bed material from the combustor were determined in a laboratory fixed bed reactor. The destruction rate of N2O...... in the combustion chamber and the cyclone was calculated taking three mechanisms into account: Reduction by char, catalytic decomposition over bed material and thermal decomposition. The calculated destruction rate was in good agreement with the measured destruction of N2O injected at different levels in the boiler...

  14. Temporal and spatial variability in thalweg profiles of a gravel-bed river

    Science.gov (United States)

    Madej, Mary Ann

    1999-01-01

    This study used successive longitudinal thalweg profiles in gravel-bed rivers to monitor changes in bed topography following floods and associated large sediment inputs. Variations in channel bed elevations, distributions of residual water depths, percentage of channel length occupied by riffles, and a spatial autocorrelation coefficient (Moran's I) were used to quantify changes in morphological diversity and spatial structure in Redwood Creek basin, northwestern California. Bed topography in Redwood Creek and its major tributaries consists primarily of a series of pools and riffles. The size, frequency and spatial distribution of the pools and riffles have changed significantly during the past 20 years. Following large floods and high sediment input in Redwood Creek and its tributaries in 1975, variation in channel bed elevations was low and the percentage of the channel length occupied by riffles was high. Over the next 20 years, variation in bed elevations increased while the length of channel occupied by riffles decreased. An index [(standard deviation of residual water depth/bankfull depth) × 100] was developed to compare variations in bed elevation over a range of stream sizes, with a higher index being indicative of greater morphological diversity. Spatial autocorrelation in the bed elevation data was apparent at both fine and coarse scales in many of the thalweg profiles and the observed spatial pattern of bed elevations was found to be related to the dominant channel material and the time since disturbance. River reaches in which forced pools dominated, and in which large woody debris and bed particles could not be easily mobilized, exhibited a random distribution of bed elevations. In contrast, in reaches where alternate bars dominated, and both wood and gravel were readily transported, regularly spaced bed topography developed at a spacing that increased with time since disturbance. This pattern of regularly spaced bed features was reversed

  15. Transient core-debris bed heat-removal experiments and analysis

    International Nuclear Information System (INIS)

    Ginsberg, T.; Klein, J.; Klages, J.; Schwarz, C.E.; Chen, J.C.

    1982-08-01

    An experimental investigation is reported of the thermal interaction between superheated core debris and water during postulated light-water reactor degraded core accidents. Data are presented for the heat transfer characteristics of packed beds of 3 mm spheres which are cooled by overlying pools of water. Results of transient bed temperature and steam flow rate measurements are presented for bed heights in the range 218 mm-433 mm and initial particle bed temperatures between 530K and 972K. Results display a two-part sequential quench process. Initial frontal cooling leaves pockets or channels of unquenched spheres. Data suggest that heat transfer process is limited by a mechanism of countercurrent two-phase flow. An analytical model which combines a bed energy equation with either a quasisteady version of the Lipinski debris bed model or a critical heat flux model reasonably well predicts the characteristic features of the bed quench process. Implications with respect to reactor safety are discussed

  16. Tanning beds: A call to action for further educational and legislative efforts.

    Science.gov (United States)

    Farley, Clara; Alimi, Yewande; Espinosa, Lauren R; Perez, Sebastian; Knechtle, William; Hestley, Andrea; Carlson, Grant W; Russell, Maria C; Delman, Keith A; Rizzo, Monica

    2015-08-01

    Melanoma is steadily increasing over the past decade. Recent studies confirmed a link between tanning bed use and melanoma. We sought to determine the prevalence and frequency of tanning bed among young patients with melanoma. We retrospectively analyzed tanning bed use among young melanoma patients compared to controls selected from the hospital medical records. A telephone survey investigated family history of melanoma or skin cancer, hair color, eye color, skin type, tanning bed use, and patient awareness of dangers of tanning bed use. A total of 601 melanoma cases were identified; 265 (44%) completed the telephone survey as did 195 (31%) controls. Of these 460 subjects, 260 were female. Females were 3.0 times more likely to have used a tanning bed. Melanoma patients had natural light color hair, blue-green eyes, and 2.0 times more likely to use a tanning bed than controls. Among the tanning bed users, 90% were aware of danger of tanning bed. Our study found that tanning beds were more likely to be used by young women, the majority of whom are aware of the associated risks. Eliminating the use of tanning beds should be considered to decrease the incidence of melanoma. © 2015 Wiley Periodicals, Inc.

  17. 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)

  18. Experimental and theoretical investigation of anaerobic fluidized bed biofilm reactors

    Directory of Open Access Journals (Sweden)

    M. Fuentes

    2009-09-01

    Full Text Available This work presents an experimental and theoretical investigation of anaerobic fluidized bed reactors (AFBRs. The bioreactors are modeled as dynamic three-phase systems. Biochemical transformations are assumed to occur only in the fluidized bed zone. The biofilm process model is coupled to the system hydrodynamic model through the biofilm detachment rate; which is assumed to be a first-order function of the energy dissipation parameter and a second order function of biofilm thickness. Non-active biomass is considered to be particulate material subject to hydrolysis. The model includes the anaerobic conversion for complex substrate degradation and kinetic parameters selected from the literature. The experimental set-up consisted of two mesophilic (36±1ºC lab-scale AFBRs (R1 and R2 loaded with sand as inert support for biofilm development. The reactor start-up policy was based on gradual increments in the organic loading rate (OLR, over a four month period. Step-type disturbances were applied on the inlet (glucose and acetic acid substrate concentration (chemical oxygen demand (COD from 0.85 to 2.66 g L-1 and on the feed flow rate (from 3.2 up to 6.0 L d-1 considering the maximum efficiency as the reactor loading rate switching. The predicted and measured responses of the total and soluble COD, volatile fatty acid (VFA concentrations, biogas production rate and pH were investigated. Regarding hydrodynamic and fluidization aspects, variations of the bed expansion due to disturbances in the inlet flow rate and the biofilm growth were measured. As rate coefficients for the biofilm detachment model, empirical values of 3.73⋅10(4 and 0.75⋅10(4 s² kg-1 m-1 for R1 and R2, respectively, were estimated.

  19. River sedimentation and channel bed characteristics in northern Ethiopia

    Science.gov (United States)

    Demissie, Biadgilgn; Billi, Paolo; Frankl, Amaury; Haile, Mitiku; Lanckriet, Sil; Nyssen, Jan

    2016-04-01

    Excessive sedimentation and flood hazard are common in ephemeral streams which are characterized by flashy floods. The purposes of this study was to investigate the temporal variability of bio-climatic factors in controlling sediment supply to downstream channel reaches and the effect of bridges on local hydro-geomorphic conditions in causing the excess sedimentation and flood hazard in ephemeral rivers of the Raya graben (northern Ethiopia). Normalized Difference Vegetation Index (NDVI) was analyzed for the study area using Landsat imageries of 1972, 1986, 2000, 2005, 2010, and 2012). Middle term, 1993-2011, daily rainfall data of three meteorological stations, namely, Alamata, Korem and Maychew, were considered to analyse the temporal trends and to calculate the return time intervals of rainfall intensity in 24 hours for 2, 5, 10 and 20 years using the log-normal and the Gumbel extreme events method. Streambed gradient and bed material grain size were measured in 22 river reaches (at bridges and upstream). In the study catchments, the maximum NDVI values were recorded in the time interval from 2000 to 2010, i.e. the decade during which the study bridges experienced the most severe excess sedimentation problems. The time series analysis for a few rainfall parameters do not show any evidence of rainfall pattern accountable for an increase in sediment delivery from the headwaters nor for the generation of higher floods with larger bedload transport capacities. Stream bed gradient and bed material grain size data were measured in order to investigate the effect of the marked decrease in width from the wide upstream channels to the narrow recently constructed bridges. The study found the narrowing of the channels due to the bridges as the main cause of the thick sedimentation that has been clogging the study bridges and increasing the frequency of overbank flows during the last 15 years. Key terms: sedimentation, ephemeral streams, sediment size, bridge clogging

  20. Comparative study between fluidized bed and fixed bed reactors in methane reforming with CO2 and O2 to produce syngas

    International Nuclear Information System (INIS)

    Jing Qiangshan; Lou Hui; Mo Liuye; Zheng Xiaoming

    2006-01-01

    Reforming of methane with carbon dioxide and oxygen was investigated over Ni/MgO-SiO 2 catalysts using fixed bed and fluidized bed reactors. The conversions of CH 4 and CO 2 in a fluidized bed reactor were close to thermodynamic equilibrium. The activity and stability of the catalyst in the fixed bed reactor were lower than that in the fluidized bed reactor due to carbon deposition and nickel sintering. TGA and TEM techniques were used to characterize the spent catalysts. The results showed that a lot of whisker carbon was found on the catalyst in the rear of the fixed bed reactor, and no deposited carbon was observed on the catalysts in the fluidized bed reactor after reaction. It is suggested that this phenomenon is related to a permanent circulation of catalyst particles between the oxygen rich and oxygen free zones. That is, fluidization of the catalysts in the fluidized bed reactor favors inhibiting deposited carbon and thermal uniformity in the reactor

  1. 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

  2. Addition of Bacillus sp. inoculums in bedding for swine on a pilot scale: effect on microbial population and bedding temperature.

    Science.gov (United States)

    Corrêa, E K; Ulguim, R R; Corrêa, L B; Castilhos, D D; Bianchi, I; Gil-Turnes, C; Lucia, T

    2012-10-01

    Thermal and microbiological characteristics of beddings for swine were compared according to their depth and of addition of inoculums. Bedding was added to boxes at 0.25 (25D) and 0.50 m (50D), with three treatments: control (no inoculums); T1, with 250 g of Bacillus cereus var. toyoii at 8.4 × 10(7) CFU; and T2, with 250 g of a pool of B. subtilis, Bacillus licheniformis and Bacillus polymyxa at 8.4 × 10(7) CFU (250 g for 25D and 500 g for 50D). Mean temperatures were 28.5 ± 3.9 at the surface and 35.2 ± 8.9 inside the beddings. The most probable number (MPN) of thermophilic bacteria was higher for T1 and T2 than for the control (P<0.05). The MPN of thermophilic bacteria and fungi was greater for D50 than for D25 (P<0.05). The use of 25D without inoculums is recommended due to the reduction of thermophilic microbiota. Copyright © 2012 Elsevier Ltd. All rights reserved.

  3. 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.

  4. 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

  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. Flaser and wavy bedding in ephemeral streams: a modern and an ancient example

    Science.gov (United States)

    Martin, A. J.

    2000-10-01

    Flaser and wavy bedding are sedimentary structures characterized by alternating rippled sand and mud layers. These structures often are considered to form mostly in tidally influenced environments; published examples from fluvial environments are rare. Flaser and wavy bedding were found in two ephemeral stream deposits: the Jurassic Kayenta Formation and the modern wash in Seven Mile Canyon, both located in southeastern Utah, USA. These examples demonstrate that flaser bedding can form and be preserved in ephemeral streams.

  7. 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

  8. 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.

  9. 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.

  10. Development and Evaluation of a Wide-Bed Former for Vegetable Cultivation in Controlled Tractor Traffic

    Science.gov (United States)

    Dixit, Anoop; Khurana, Rohinish; Verma, Aseem; Singh, Arshdeep; Manes, G. S.

    2018-05-01

    India is the second largest producer of vegetables in the world. For vegetable cultivation, a good seed bed preparation is an important task which involves 6-10 different operations. To tackle the issue of multiple operations, a prototype of tractor operated wide bed former was developed and evaluated. The machine comprises of a rotary tiller and a bed forming setup. It forms bed of 1000 mm top width which is suitable as per the track width of an average sized tractor in India. The height of the beds formed is 130 mm whereas the top and bottom width of channel formed on both sides of the bed is 330 and 40 mm respectively at soil moisture content of 12.5-16% (db). The forward speed of 2.75 km/h was observed to be suitable for proper bed formation. The average fuel consumption of the machine was 5.9 l/h. The average bulk density of soil before and after the bed formation was 1.46 and 1.63 g/cc respectively. Field capacity of the machine was found to be 0.31 ha/h. The machine resulted in 93.8% labour saving and 80.4% saving in cost of bed preparation as compared to conventional farmer practice. Overall performance of wide-bed former was found to be satisfactory.

  11. Cyclic Sediment Trading Between Channel and River Bed Sediments

    Science.gov (United States)

    Haddadchi, A.

    2015-12-01

    Much of the previous work on sediment tracing has focused on determining either the initial sources of the sediment (soils derive from a particular rock type) or the erosion processes generating the sediment. However, alluvial stores can be both a source and sink for sediment transported by streams. Here geochemical and fallout radionuclide tracing of river-bed and alluvial sediments are used to determine the role of secondary sources, sediment stores, as potential sources of sediment leaving Emu Creek catchment, southeastern Queensland, Australia. Activity concentrations of 137Cs on the river sediments are consistent with channel erosion being the dominant source at all sites sampled along the river. To characterise the deposition and remobilisation cycles in the catchment, a novel geochemical tracing approach was used. Successive pockets of alluvium were treated as discrete sink terms within geochemical mixing models and their source contributions compared with those of river bed sediments collected adjacent to each alluvial pocket. Three different size fractions were examined; silts and clays (banks indicates a high degree of 'trading' between the fluvial space and the alluvial space. Hence, management works aimed at primarily reducing the supply of sediments to the outlet of Emu Creek should focus on rehabilitation of channel banks in the lower catchment.

  12. Dryout heat flux and flooding phenomena in debris beds consisting of homogeneous diameter particles

    International Nuclear Information System (INIS)

    Maruyama, Yu; Abe, Yutaka; Yamano, Norihiro; Soda, Kunihisa

    1988-08-01

    Since the TMI-2 accident, which occurred in 1979, necessity of understanding phenomena associated with a severe accident have been recognized and researches have been conducted in many countries. During a severe accident of a light water reactor, a debris bed consisting of the degraded core materials would be formed. Because the debris bed continues to release decay heat, the debris bed would remelt when the coolable geometry is not maintained. Thus the degraded core coolability experiments to investigate the influence of the debris particle diameter and coolant flow conditions on the coolability of the debris bed and the flooding experiments to investigate the dependence of flooding phenomena on the configuration of the debris bed have been conducted in JAERI. From the degraded core coolability experiments, the following conclusions were derived; the coolability of debris beds would be improved by coolant supply into the beds, Lipinski's 1-dimensional model shows good agreement with the measured dryout heat flux for the beds under stagnant and forced flow conditions from the bottom of the beds, and the analytical model used for the case that coolant is fed by natural circulation through the downcomer reproduces the experimental results. And the following conclusions were given from the flooding experiments ; no dependence between bed height and the flooding constant exists for the beds lower than the critical bed height, flooding phenomena of the stratified beds would be dominated by the layer consisting of smaller particles, and the predicted dryout heat flux by the analytical model based on the flooding theory gives underestimation under stagnant condition. (author)

  13. Improved Gasifier Availability with Bed Material and Additives

    Energy Technology Data Exchange (ETDEWEB)

    Grootjes, A.J.; Van der Meijden, C.M.; Visser, H.J.M.; Van der Drift, A. [ECN Biomass and Energy Efficiency, Petten (Netherlands)

    2013-07-15

    In order to valorize several feedstock, gasification is one of the technologies developed over the past decades. ECN developed the MILENA gasifier. In order for MILENA to become a commercial success, the gasifier needs to be feedstock flexible, robust and economically sound, operating with high availability. One of the characteristics of MILENA is high efficiency but with a higher tar content, compared to some other Dual Fluidized Bed (DFB) gasifiers. In order to reduce the issues that are associated with high tar levels in the product gas, the effect of a number of primary measures was studied. This paper presents results obtained in the last two years, focused on improving the gasifier availability by conducting experiments in a 25 kWth lab scale MILENA gasifier. Amongst others, gas composition, tar content and calorific value of the product gas were compared. Scanning Electron Microscope analysis was used to investigate bed material changes. Results show that Austrian olivine can be activated by Fuel B as well as by Additive A and B. The water-gas shift reaction is enhanced and the tar content is reduced significantly, especially the heavy tars that dominate the tar dew point. Activated olivine has a calcium-rich layer. The results show that with MILENA, we are able to lower and control the tar dew point, which will possibly increase the availability of a MILENA gasifier.

  14. 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.

  15. Experimental study on coolability of particulate core-metal debris bed with oxidization, (2). Fragmentation and enhanced heat transfer in zircaloy debris bed

    International Nuclear Information System (INIS)

    Su, Guanghui; Sugiyama, Ken-ichiro; Aoki, Hiroomi; Kimura, Iichi

    2006-01-01

    The oxidization and coolability characteristics of the particulate Zircaloy debris bed, which is deposited under the hard debris and through which first vapor penetrates and then water penetrates, are studied in the present paper. In the vapor penetration experiments, it is found that Zircaloy debris particles are effectively broken into small pieces after making thick oxidized layer with deep clacks by rapid oxidization under the condition that vapor with 20 cm/s penetrates for 30 to 70 min at an initial debris bed temperature of 1,030degC. It is also confirmed in the water penetration experiments that the oxidized particle debris bed has potentially of high coolability when water penetrates through the fully oxidized particle bed because of a high capillary force originating from those particles with deep cracks on their surfaces. Based on the present study, a new scenario for the appearance and disappearance of the hot spot in the TMI-2 accident is possible. The particulate core-metal core-metal debris bed is first heated up by rapid oxidization with heat generation when vapor can penetrate through the debris bed with porosities. This corresponds to the appearance of the hot spot. The resultant oxidized particulate debris bed causes a high coolability due to its high capillary force when the water can touch the debris bed at wet condition. This corresponds to the disappearance of the hot spot. (author)

  16. Management and characteristics of recycled manure solids used for bedding in Midwest freestall dairy herds.

    Science.gov (United States)

    Husfeldt, A W; Endres, M I; Salfer, J A; Janni, K A

    2012-04-01

    Interest in using recycled manure solids (RMS) as a bedding material for dairy cows has grown in the US Midwest. Cost of common bedding materials has increased in recent years and availability has decreased. Information regarding the composition of RMS and its use as a bedding material for dairy cows in the Midwest is very limited. The objectives of this study were to characterize RMS as a bedding material, observe bedding management practices, document methods of obtaining RMS, and describe housing facilities. We visited 38 Midwest dairy operations bedding freestalls with RMS to collect data. Methods of obtaining RMS for bedding included separation of anaerobic digested manure, separation of raw manure, and separation of raw manure followed by mechanical drum-composting for 18 to 24 h. Average bedding moisture of unused RMS was 72.4% with a pH of 9.16. Unused samples contained (on a dry basis) 1.4% N, 44.9% C, 32.7C:N ratio, 0.44% P, 0.70% K, 76.5% neutral detergent fiber, 9.4% ash, 4.4% nonfiber carbohydrates, and 1.1% fat. Moisture was lowest for drum-composted solids before and after use as freestall bedding. After use in the stalls, digested solids had lower neutral detergent fiber content (70.5%) than drum-composted (75.0%) and separated raw (73.1%) solids. Total N content was greater in digested solids (2.0%) than in separated raw (1.7%) solids. Total bacterial populations in unused bedding were greatest in separated raw manure solids but were similar between digested and drum-composted manure solids. Drum-composted manure solids had no coliform bacteria before use as freestall bedding. After use as bedding, digested manure solids had lower total bacteria counts compared with drum-composted and separated raw manure solids, which had similar counts. Used bedding samples of digested solids contained fewer environmental streptococci than drum-composted and separated raw solids and had reduced Bacillus counts compared with separated raw solids. Coliform counts

  17. 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

  18. 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.

  19. 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.

  20. Novel instrumentation to detect sliding and erratic bed load motion

    CSIR Research Space (South Africa)

    Ilgner, HJ

    2014-09-01

    Full Text Available stationary beds on thick-walled pipes within a minute, only the 2 mm-thin spool pieces were able to detect erratic bed motions due to the sensors’ fast response capability. This required additional features to focus the sensing area directly onto the pipe...

  1. 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.

  2. 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...

  3. Scaling relationships between bed load volumes, transport distances, and stream power in steep mountain channels

    Science.gov (United States)

    Schneider, Johannes M.; Turowski, Jens M.; Rickenmann, Dieter; Hegglin, Ramon; Arrigo, Sabrina; Mao, Luca; Kirchner, James W.

    2014-03-01

    Bed load transport during storm events is both an agent of geomorphic change and a significant natural hazard in mountain regions. Thus, predicting bed load transport is a central challenge in fluvial geomorphology and natural hazard risk assessment. Bed load transport during storm events depends on the width and depth of bed scour, as well as the transport distances of individual sediment grains. We traced individual gravels in two steep mountain streams, the Erlenbach (Switzerland) and Rio Cordon (Italy), using magnetic and radio frequency identification tags, and measured their bed load transport rates using calibrated geophone bed load sensors in the Erlenbach and a bed load trap in the Rio Cordon. Tracer transport distances and bed load volumes exhibited approximate power law scaling with both the peak stream power and the cumulative stream energy of individual hydrologic events. Bed load volumes scaled much more steeply with peak stream power and cumulative stream energy than tracer transport distances did, and bed load volumes scaled as roughly the third power of transport distances. These observations imply that large bed load transport events become large primarily by scouring the bed deeper and wider, and only secondarily by transporting the mobilized sediment farther. Using the sediment continuity equation, we can estimate the mean effective thickness of the actively transported layer, averaged over the entire channel width and the duration of individual flow events. This active layer thickness also followed approximate power law scaling with peak stream power and cumulative stream energy and ranged up to 0.57 m in the Erlenbach, broadly consistent with independent measurements.

  4. Endotoxin, Coliform, and Dust Levels in Various Types of Rodent Bedding

    OpenAIRE

    Whiteside, Tanya E; Thigpen, Julius E; Kissling, Grace E; Grant, Mary G; Forsythe, Diane B

    2010-01-01

    Endotoxins in grain dust, household dust, and animal bedding may induce respiratory symptoms in rodents and humans. We assayed the endotoxin, coliform, and dust levels in 20 types of rodent bedding. Endotoxin concentrations were measured by using a commercial test kit, coliform counts were determined by using conventional microbiologic procedures, and dust content was evaluated by using a rotating–tapping shaker. Paper bedding types contained significantly less endotoxin than did other beddin...

  5. 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)

  6. Peach and apricot stone combustion in a bubbling fluidized bed

    Energy Technology Data Exchange (ETDEWEB)

    Kaynak, B.; Atimtay, Aysel T. [Department of Environmental Engineering, Middle East Technical University, Ankara 06531 (Turkey); Topal, H. [Department of Mechanical Engineering, Engineering and Architecture Faculty, Gazi University, Ankara 06570 (Turkey)

    2005-07-25

    In this study, a bubbling fluidized bed combustor (BFBC) of 102 mm inside diameter and 900 mm height was used to investigate the combustion characteristics of peach and apricot stones produced as a waste from the fruit juice industry. A lignite coal was also burned in the same combustor. The combustion characteristics of the wastes were compared with that of a lignite coal that is most widely used in Turkey. On-line concentrations of O{sub 2}, CO, CO{sub 2}, SO{sub 2}, NO{sub X} and total hydrocarbons (C{sub m}H{sub n}) were measured in the flue gas during combustion experiments. By changing the operating parameters (excess air ratio, fluidization velocity, and fuel feed rate), the variation of emissions of various pollutants was studied. Temperature distribution along the bed was measured with thermocouples. During the combustion tests, it was observed that the volatile matter from peach and apricot stones quickly volatilizes and mostly burn in the freeboard. The temperature profiles along the bed and the freeboard also confirmed this phenomenon. It was found that as the volatile matter of fruit stones increases, the combustion takes place more in the freeboard region. The results of this study have shown that the combustion efficiencies ranged between 98.8% and 99.1% for coal, 96.0% and 97.5% for peach stone and 93.4% and 96.3% for apricot stones. The coal has zero CO emission, but biomass fuels have very high CO emission which indicates that a secondary air addition is required for the system. SO{sub 2} emission of the coal is around 2400-2800 mg/Nm{sup 3}, whereas the biomass fuels have zero SO{sub 2} emission. NO{sub x} emissions are all below the limits set by the Turkish Air Quality Control Regulation of 1986 (TAQCR) for all tests. As the results of combustion of two biomass fuels are compared with each other, peach stones gave lower CO and NO{sub x} emissions but the SO{sub 2} emissions are a little higher than for apricot stones. These results suggest that

  7. 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

  8. Changes in markers of bone formation and resorption in a bed rest model of weightlessness

    Science.gov (United States)

    Lueken, S. A.; Arnaud, S. B.; Taylor, A. K.; Baylink, D. J.

    1993-01-01

    To study the mechanism of bone loss in physical unloading, we examined indices of bone formation and bone resorption in the serum and urine of eight healthy men during a 7 day -6 degrees head-down tilt bed rest. Prompt increases in markers of resorption--pyridinoline (PD), deoxypyridinoline (DPD), and hydroxyproline (Hyp)/g creatinine--during the first few days of inactivity were paralleled by tartrate-resistant acid phosphatase (TRAP) with significant increases in all these markers by day 4 of bed rest. An index of formation, skeletal alkaline phosphatase (SALP), did not change during bed rest and showed a moderate 15% increase 1 week after reambulation. In contrast to SALP, serum osteocalcin (OC) began increasing the day preceding the increase in Hyp, remained elevated for the duration of the bed rest, and returned to pre-bed rest values within 5 days of reambulation. Similarly, DPD increased significantly at the onset of bed rest, remained elevated for the duration of bed rest, and returned to pre-bed rest levels upon reambulation. On the other hand, the other three indices of resorption, Hyp, PD, and TRAP, remained elevated for 2 weeks after reambulation. The most sensitive indices of the levels of physical activity proved to be the noncollagenous protein, OC, and the collagen crosslinker, DPD. The bed rest values of both these markers were significantly elevated compared to both the pre-bed rest values and the post-bed rest values. The sequence of changes in the circulating markers of bone metabolism indicated that increases in serum OC are the earliest responses of bone to head-down tilt bed rest.

  9. Sediment Transport on Continental Shelves: Storm Bed Formation and Preservation in Heterogeneous Sediments

    Science.gov (United States)

    2012-01-01

    occurred during the Cretaceous period. The simulated storm bed for such an extratropical cyclone that lasts 4 days was deposited as deep as 75 m and had...Int. Assoc. Sedimentol. Spec. Publ. (2012) 44, 295-310 Sediment transport on continental shelves: storm bed formation and preservation in...xDept. of Earth Science, Memorial University of Newfoundland, St. Johns, Newfoundland, Canada ABSTRACT Many storm beds are constructed of silt/sand

  10. 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.

  11. 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.

  12. Brief analysis on relationship between red beds and sandstone-type uranium ore-formation

    International Nuclear Information System (INIS)

    Ji Zengxian

    2006-01-01

    Red beds are sandy gravel beds deposited under the arid and hot climates and correspondent to the oxidation environment of continental basins. As an exogenetic epigenetic uranium deposit, the formation of the sandstone-type uranium deposit needs a large chronologic gap between the diagenesis and the subsequent uranium metallogenesis of the ore-hosting target layer with a sedimentary discontinuity and an alternative humid-arid climate. Red beds are the product of this time. The evolutionary times of red beds are in accordance with the formation of the sandstone-type uranium deposit. Both domestic and abroad researches indicate that each times evolution of a red bed might be associated with uranium ore-formation in one or more sandstone layers in the region. In China, red beds are developed in many geologic periods, but sandstone-type uranium mineralization occurs mostly in Mesozoic-Cenozoic. Taking five known sandstone-type uranium deposits as examples, the author makes a primary analysis on the relationship between red beds and the subsequent sandstone-type uranium mineralization. It is suggested that the deposition of red beds and sandstone-type uranium metallogenesis are of 'cogenesis and coexistence' and that the deposition of red beds and its evolutionary times can be regarded as the prerequisites to judge the potential of sandstone-type uranium mineralization in a Mesozoic-Cenozoic sedimentary basin. (authors)

  13. Chemical Characterization of Bed Material Coatingsby LA-ICP-MS and SEM-EDS

    Science.gov (United States)

    Piispanen, M. H.; Mustonen, A. J.; Tiainen, M. S.; Laitinen, R. S.

    Bed material coatings and the consequent agglomeration of bed material are main ash-related problems in FB-boilers. The bed agglomeration is a particular problem when combusting biofuels and waste materials. Whereas SEM-EDS together with automated image processing has proven to be a convenient method to study compositional distribution in coating layers and agglomerates, it is a relatively expensive technique and is not necessarily widely available. In this contribution, we explore the suitability of LA-ICP-MS to provide analogous information of the bed.

  14. 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.

  15. 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.

  16. Sorting it out: bedding particle size and nesting material processing method affect nest complexity.

    Science.gov (United States)

    Robinson-Junker, Amy; Morin, Amelia; Pritchett-Corning, Kathleen; Gaskill, Brianna N

    2017-04-01

    As part of routine husbandry, an increasing number of laboratory mice receive nesting material in addition to standard bedding material in their cages. Nesting material improves health outcomes and physiological performance in mice that receive it. Providing usable nesting material uniformly and efficiently to various strains of mice remains a challenge. The aim of this study was to determine how bedding particle size, method of nesting material delivery, and processing of the nesting material before delivery affected nest building in mice of strong (BALB/cAnNCrl) and weak (C3H/HeNCrl) gathering abilities. Our data suggest that processing nesting material through a grinder in conjunction with bedding material, although convenient for provision of bedding with nesting material 'built-in', negatively affects the integrity of the nesting material and subsequent nest-building outcomes. We also found that C3H mice, previously thought to be poor nest builders, built similarly scored nests to those of BALB/c mice when provided with unprocessed nesting material. This was true even when nesting material was mixed into the bedding substrate. We also observed that when nesting material was mixed into the bedding substrate, mice of both strains would sort their bedding by particle size more often than if it were not mixed in. Our findings support the utility of the practice of distributing nesting material mixed in with bedding substrate, but not that of processing the nesting material with the bedding in order to mix them.

  17. Integrated drying and incineration of wet sewage sludge in combined bubbling and circulating fluidized bed units.

    Science.gov (United States)

    Li, Shiyuan; Li, Yunyu; Lu, Qinggang; Zhu, Jianguo; Yao, Yao; Bao, Shaolin

    2014-12-01

    An original integrated drying and incineration technique is proposed to dispose of sewage sludge with moisture content of about 80% in a circulating fluidized bed. This system combines a bubbling fluidized bed dryer with a circulating fluidized bed incinerator. After drying, sewage sludge with moisture less than 20% is transported directly and continuously from the fluidized bed dryer into a circulating fluidized bed incinerator. Pilot plant results showed that integrated drying and incineration is feasible in a unique single system. A 100 t/d Sewage Sludge Incineration Demonstration Project was constructed at the Qige sewage treatment plant in Hangzhou City in China. The operational performance showed that the main operation results conformed to the design values, from which it can be concluded that the scale-up of this technique is deemed both feasible and successful. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. 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.

  19. A survey of attitudes, beliefs, and behavior regarding tanning bed use, sunbathing, and sunscreen use.

    Science.gov (United States)

    Mawn, V B; Fleischer, A B

    1993-12-01

    Although cosmetic tanning and unprotected solar exposure are common, little is known about general attitudes, beliefs, and behavior regarding sunbathing, sunscreen use, and tanning salon use. We sought to determine the frequency of UV exposure in a select sample and to assess the knowledge and beliefs of the effects of UV irradiation. A written, anonymous questionnaire was distributed to a sample of 477 persons in a shopping mall, at a social gathering, and on a vacation cruise ship. The instrument explored demographic information, sunscreen use, sunbathing habits, tanning bed use, and cutaneous solar effects. Forty-two percent of respondents seldom or never used sunscreen, and 33% sunbathed at least once a week. Although the three sample populations differed in education, sunbathing habits, sunscreen use, and tanning bed use, they were equally informed about UV light hazards. Compared with those who had not used tanning beds, tanning bed users were more likely to be female and more knowledgeable about the long-term effects of UV. Tanning beds were most commonly used in tanning or hair salons, (mean 23 +/- 7 minutes at 2.3 +/- 1.1 times per week). Reported positive psychologic sequelae from tanning bed use were more common than negative physical sequelae. At least 10% would continue to use tanning beds if these were proved to cause skin cancer. In this select sample, sunbathing and tanning bed use were common. No group surveyed universally practiced sun protection and avoidance. Clientele of tanning beds may be aware of the damaging effects of the sun, but may not be aware that tanning bed use is associated with skin damage.

  20. 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.

  1. BedMachine v3: Complete Bed Topography and Ocean Bathymetry Mapping of Greenland From Multibeam Echo Sounding Combined With Mass Conservation

    DEFF Research Database (Denmark)

    Morlighem, M.; Williams, C. N.; Rignot, E.

    2017-01-01

    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...

  2. Water holding capacity and evaporative loss from organic bedding materials used in livestock facilities

    Science.gov (United States)

    Physical and chemical characteristics of organic bedding materials determine how well they will absorb and retain moisture and may influence the environment in livestock facilities where bedding is used. The objective of this study was to determine water holding capacity (WHC) and rate of evaporativ...

  3. 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

  4. Process and technological wastes compaction through a fluidized bed incineration process

    International Nuclear Information System (INIS)

    Guiroy, J.J.

    1993-01-01

    The various fluidized bed systems (dense or circulating) are reviewed and the advantages of the circulation fluidized bed are highlighted (excellent combustion performance, clean combustion, large operating range, poly-functionality with regards to waste type, ...). Applications to contaminated graphite (with the problem of ash management) and to plant process wastes (ion exchangers, technological wastes, aqueous effluents); study of the neutralization and chlorine emission

  5. 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.…

  6. Effect of Bedding Material on Dust and Ammonia Emission from Broiler Houses

    NARCIS (Netherlands)

    Harn, van J.; Aarnink, A.J.A.; Mosquera Losada, J.; Riel, van J.W.; Ogink, N.W.M.

    2012-01-01

    Ammonia emission, Bedding material, Broilers, Dust emission The objective of this study was to determine the effects of different bedding materials on fine dust (PM10 and PM2.5) and ammonia emissions from broiler houses. The effects on broiler performance and footpad lesions were also studied. The

  7. Decisions of black parents about infant bedding and sleep surfaces: a qualitative study.

    Science.gov (United States)

    Ajao, Taiwo I; Oden, Rosalind P; Joyner, Brandi L; Moon, Rachel Y

    2011-09-01

    The goal of this qualitative study was to examine factors influencing decisions by black parents regarding use of soft bedding and sleep surfaces for their infants. We conducted focus groups and individual interviews with black mothers of lower and higher socioeconomic status (SES). Mothers were asked about many infant care practices, including sleep surface and bedding. Eighty-three mothers were interviewed, 73 (47 lower and 26 higher SES) in focus groups and 10 (7 lower and 3 higher SES) in individual interviews. The primary reason for using soft surfaces was infant comfort. Parents perceived that infants were uncomfortable if the surface was not soft. Many parents also interpreted "firm sleep surface" to mean taut; they were comfortable with and believed that they were following recommendations for a firm sleep surface when they placed pillows/blankets on the mattress as long as a sheet was pulled tautly over the pillows/blankets. The primary reasons for using soft bedding (including bumper pads) were comfort, safety, and aesthetics. In addition to using bedding to soften sleep surfaces, bedding was used to prevent infant rollover and falls, particularly for infants sleeping on a bed or sofa. Some parents used soft bedding to create an attractive space for the infant. Many black parents believe that soft bedding will keep their infant safe and comfortable. There is much misunderstanding about the meaning of a "firm" sleep surface. Additional educational messages apparently are needed to change parental perceptions and practices.

  8. 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.

  9. Suppressing immature house and stable flies in outdoor calf hutches with sand, gravel, and sawdust bedding.

    Science.gov (United States)

    Schmidtmann, E T

    1991-11-01

    Sand, gravel, sawdust, and pine shavings were used as bedding in outdoor calf hutches and compared with straw relative to the density of immature (maggot) house flies, Musca domestica, and stable flies, Stomoxys calcitrans. In 6-wk field trials, average densities of house and stable fly maggots in concrete mix sand ranged from only .3 to 1.6 and 0 to .1 maggots/L, respectively; pea size gravel bedding also strongly suppressed densities from less than .1 to .3 and less than .1 to .1 maggots/L, respectively. These densities represent reductions of 76 to greater than 99% relative to straw bedding, but both sand and gravel compacted and became soiled with calf feces, which resulted in unacceptable bedding sanitation and foul odors. Densities of house and stable fly maggots in pine shavings did not differ from those in straw bedding. Nevertheless, in sawdust bedding, maggot density was limited to averages of 1.4 to 8.3 house and 9.8 to 11.8 stable fly maggots/L; this represented reductions of 45 to 91% relative to straw. In a follow-up trial, house and stable fly maggot densities in sawdust averaged 11.3 and 43.9 maggots/L, respectively, reductions of 77 and 46%. These findings suggest that bedding calf hutches with sawdust during warm weather can be useful as an ecologically sound approach to controlling muscoid fly populations on dairy farms.

  10. Experimental Study of the Flooding and Appearance of a Bubble Bed on Top of a Countercurrent Packed-Bed Column

    Czech Academy of Sciences Publication Activity Database

    Jiřičný, Vladimír; Staněk, Vladimír; Svoboda, Petr; Ondráček, Jakub

    2001-01-01

    Roč. 40, č. 1 (2001), s. 407-412 ISSN 0888-5885 R&D Projects: GA ČR GA203/97/1174 Institutional research plan: CEZ:AV0Z4072921 Keywords : appearance * bubble-bed * packed bed column Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 1.351, year: 2001

  11. Visual observations of individual particle behaviour in gas and liquid fluidized beds

    NARCIS (Netherlands)

    Hartholt, G.P; Hoffmann, A.C; Janssen, L.P.B.M.

    The behaviour of the individual particles in dense gas and liquid fluidized beds and the behaviour of the jetsam particles in gas fluidized beds containing binary mixtures of different density group B powders has been observed. These visualizations have been made by means of an optical probe fitted

  12. Sampling interval analysis and CDF generation for grain-scale gravel bed topography

    Science.gov (United States)

    In river hydraulics, there is a continuing need for characterizing bed elevations to arrive at quantitative roughness measures that can be used in predicting flow depth and for improved prediction of fine-sediment transport over and through coarse beds. Recently published prediction methods require...

  13. A mathematical model of the flow and bed topography in curved channels

    NARCIS (Netherlands)

    Olesen, K.W.

    1985-01-01

    A two-dimensional horizontal mathematical model of the flow and bed topography in alluvial channel bends is presented. The applicability of the model is restricted to channels of which the width-depth ratio is large, the Froude number is small, bed load is dominant and grain sorting effects are

  14. Combustion and co-combustion of biomass in a bubbling fluidized bed boiler

    NARCIS (Netherlands)

    Khan, A.A.

    2007-01-01

    This PhD dissertation concerns the study of different aspects of biomass (co)-combustion in small-scale fluidized bed boilers for heat generation. The most renowned gaseous emissions from fluidized bed combustion, namely, CO and NO, are investigated with the help of experimental and theoretical

  15. 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%.

  16. Feather bedding and childhood asthma associated with house dust mite sensitisation : a randomised controlled trial

    NARCIS (Netherlands)

    Glasgow, Nicholas J.; Ponsonby, Anne-Louise; Kemp, Andrew; Tovey, Euan; van Asperen, Peter; McKay, Karen; Forbes, Samantha

    Introduction Observational studies report inverse associations between the use of feather upper bedding (pillow and/or quilt) and asthma symptoms but there is no randomised controlled trial (RCT) evidence assessing the role of feather upper bedding as a secondary prevention measure. Objective To

  17. 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.

  18. Fluidised bed combustion: a new route to power and heat from coal

    Energy Technology Data Exchange (ETDEWEB)

    Schilling, H D [Bergbau-Forschung G.m.b.H., Essen (Germany, F.R.)

    1978-02-01

    The functioning of fluidized-bed firings and their advantages with regard to SO/sub 2/ emissions are described. The principle of design of a fluidized-bed boiler and a gas/steam turbine power plant with fluidized-bed firing under pressure is outlined. The application and their economics in heat and power generation and marketing potential of fluidized-bed firings and their economics in heat and power generation is pointed out. The construction of waste-fired incinerators has already become possible, but there is still a lot of development work to be done until fluidized-bed firings can be used in central heatings, combined-cycle power plants, and large power plants.

  19. 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

  20. 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

  1. 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.

  2. 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

  3. 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

  4. Models for dryout in debris beds. Review and application to the analysis of PAHR

    International Nuclear Information System (INIS)

    Yamakoshi, Yoshinori

    2000-03-01

    There are many models for dryout in debiris beds and various conditions under which these models are applicable. For a reliable analysis of post-accident heat removal (PAHR), it is important that characteristics and applicability of each model should be made clear. In this report, formulation of the models for dryout and applicability of them are studied through comparing with experimental data. A new model for dryout prediction is also discussed here. It is difficult to predict the dryout power especially for a relatively shallow bed using a conventional model for channeled beds. The new model, which is based on the one-dimensional model derived by Lipinski, has permeability of channels in the governing equation, and enables us to predict the dryout power for relatively shallow beds. The following conclusions are derived from comparing the predicted dryout power with experimental data. The model for series heat removal is applicable to a packed bed while the DEBRIS-MD underestimates the dryout power for it. Either the original model assuming channel formation on the top of the bed or the modified model is applicable to a relatively deep bed with channels. For a relatively shallow bed with channels, the dryout power predicted by the modified model agrees with the experimental data in comparison with other models. (author)

  5. 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 ...

  6. Phase lags in oscillatory sheet flow: experiments and bed load modelling

    NARCIS (Netherlands)

    Dohmen-Janssen, Catarine M.; Kroekenstoel, D.F.; Kroekenstoel, D.F.; Hassan, Wael; Ribberink, Jan S.

    2002-01-01

    Sheet flow corresponds to the high velocity regime when small bed ripples are washed out and sand is transported in a thin layer close to the bed. Therefore, it is often assumed that sand transport in oscillatory sheet flow behaves quasi-steady: time-dependent transport rates are assumed to be

  7. Control, data acquisition and analysis for the JET neutral injection test bed

    International Nuclear Information System (INIS)

    Jones, T.T.C.; Brenan, P.R.; Rodgers, M.E.; Stork, D.; Young, I.D.

    1984-01-01

    The Neutral Injection Test-Bed (NITB) is a major experimental assembly in support of the Neutral Beam Heating Programme for JET. In addition to its prime function of testing the Neutral Injection hardware, the Test Bed serves as the prototype to test the computer control and data acquisition system, which is described. (author)

  8. Vertical sorting and the morphodynamics of bed form-dominated rivers : a sorting evolution model

    NARCIS (Netherlands)

    Blom, Astrid; Ribberink, Jan S.; Parker, Gary

    2008-01-01

    Existing sediment continuity models for nonuniform sediment suffer from a number of shortcomings, as they fail to describe vertical sorting fluxes other than through net aggradation or degradation of the bed and are based on a discrete representation of the bed material interacting with the flow. We

  9. Heat transfer between a fluidized bed and an immersed horizontal tube

    International Nuclear Information System (INIS)

    Beasley, D.E.; Figliola, R.S.

    1986-01-01

    Reliable predictions will require a better understanding of the heat transfer mechanisms and bed hydrodynamics in the neighborhood of the submerged surface. In this investigation measurements of the instantaneous heat transfer between a submerged surface and a gas fluidized bed operating in the bubbling regime are presented. The experimental results are compared to existing predictive models for the particle convective and the overall heat transfer coefficients. For the range of particle size and flow velocity studied, the particle convective component of heat transfer dominates the overall heat transfer between the bed and the submerged surface. Experimental studies into particle size distribution effects on heat transfer suggest that mixtures augment the bed to surface heat transfer. Documentation of bed particle size distribution is necessary if heat transfer data are to be compared or predicted

  10. 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)

  11. 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

  12. 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

  13. 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)

  14. 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.

  15. Method and apparatus for adding and mixing second cohesive powders in a fluidized bed blender

    International Nuclear Information System (INIS)

    Larson, R.I.; Brassfield, H.C.; Adomitis, J.T.

    1981-01-01

    Injection and uniform dispersion of a second cohesive powdered ingredient or ingredients having hydrophobic, hydrophilic or hydroscopic properties into a fluidized bed of UO 2 powder is effected by impinging the second ingredient against a deflection plate 21 mounted within the fluidized bed. The apparatus also includes an eductor, a pressurised vortex mill 11 and a pneumatic conveying system. Before entering the fluidized bed, the second ingredient is entrained in a gas and conveyed under pressure to the vortex mill 11 where the particles of the second ingredient are propelled radially outwardly through channels 28 and collide against tungsten carbide impact, blocks 32 causing comminution of the particles. (author)

  16. 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)

  17. 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.

  18. 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)

  19. Enhanced stability of steep channel beds to mass failure and debris flow initiation

    Science.gov (United States)

    Prancevic, J.; Lamb, M. P.; Ayoub, F.; Venditti, J. G.

    2015-12-01

    Debris flows dominate bedrock erosion and sediment transport in very steep mountain channels, and are often initiated from failure of channel-bed alluvium during storms. While several theoretical models exist to predict mass failures, few have been tested because observations of in-channel bed failures are extremely limited. To fill this gap in our understanding, we performed laboratory flume experiments to identify the conditions necessary to initiate bed failures in non-cohesive sediment of different sizes (D = 0.7 mm to 15 mm) on steep channel-bed slopes (S = 0.45 to 0.93) and in the presence of water flow. In beds composed of sand, failures occurred under sub-saturated conditions on steep bed slopes (S > 0.5) and under super-saturated conditions at lower slopes. In beds of gravel, however, failures occurred only under super-saturated conditions at all tested slopes, even those approaching the dry angle of repose. Consistent with theoretical models, mass failures under super-saturated conditions initiated along a failure plane approximately one grain-diameter below the bed surface, whereas the failure plane was located near the base of the bed under sub-saturated conditions. However, all experimental beds were more stable than predicted by 1-D infinite-slope stability models. In partially saturated sand, enhanced stability appears to result from suction stress. Enhanced stability in gravel may result from turbulent energy losses in pores or increased granular friction for failures that are shallow with respect to grain size. These grain-size dependent effects are not currently included in stability models for non-cohesive sediment, and they may help to explain better the timing and location of debris flow occurrence.

  20. Sealing considerations for repository shafts in bedded and dome salt

    International Nuclear Information System (INIS)

    1981-12-01

    The report reviews the geologic and hydrologic data base for penetration seal designs referenced to the Los Medanos bedded salt site in New Mexico and to four candidate salt domes in the Gulf Interior. Experience with existing shafts highlights the importance, for shaft decommissioning as well as operation, of achieving an adequate seal at and immediately below the top of salt. Possible construction procedures for repository shafts are reviewed, noting advantages and disadvantages with respect to repository sealing. At this stage, there does not appear to be a clear preference for excavation by drill and blast or by drilling. If conventional drill and blast methods are used, it may be necessary to grout in permeable zones above the salt. An important consideration with respect to sealing is that grouting operations (or freezing should it be used) should not establish connections between the top of salt and water-bearing zones higher in the stratigraphic section. Generally, it is concluded that Los Medanos and the dome salt sites are favorable candidate repository sites from the point of view of sealing

  1. 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.

  2. 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.

  3. Nitrogen utilization and biomass yield in trickle bed air biofilters.

    Science.gov (United States)

    Kim, Daekeun; Sorial, George A

    2010-10-15

    Nitrogen utilization and subsequent biomass yield were investigated in four independent lab-scale trickle bed air biofilters (TBABs) fed with different VOCs substrate. The VOCs considered were two aromatic (toluene, styrene) and two oxygenated (methyl ethyl ketone (MEK), methyl isobutyl ketone (MIBK)). Long-term observations of TBABs performances show that more nitrogen was required to sustain high VOC removal, but the one fed with a high loading of VOC utilized much more nitrogen for sustaining biomass yield. The ratio N(consumption)/N(growth) was an effective indicator in evaluating nitrogen utilization in the system. Substrate VOC availability in the system was significant in determining nitrogen utilization and biomass yield. VOC substrate availability in the TBAB system was effectively identified by using maximum practical concentrations in the biofilm. Biomass yield coefficient, which was driven from the regression analysis between CO(2) production rate and substrate consumption rate, was effective in evaluating the TBAB performance with respect to nitrogen utilization and VOC removal. Biomass yield coefficients (g biomass/g substrate, dry weight basis) were observed to be 0.668, 0.642, 0.737, and 0.939 for toluene, styrene, MEK, and MIBK, respectively. 2010 Elsevier B.V. All rights reserved.

  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. 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

  6. Investigation of Adsorbed Gases Content in Coal Beds in Bosnia and Herzegovina

    Directory of Open Access Journals (Sweden)

    Sadadinovic, J.

    2008-09-01

    Full Text Available Investigation of the gas fraction in coal beds in Bosnia & Herzegovina has been performed systematically since 1988. Gas in coal beds can be present in free or adsorbed form, and dissolved in water. Methods of investigation are based on the direct approach, according to which the gas fraction is determined in the undisturbed coal bed.The quantity of the adsorbed and free gas in the coal bed is directly proportional to the gas pressure. Dependence is hyperbolic. The quantity of the free gas in mining conditions is being determined by measurement of the desorption index (Δp2. The desorption index for the Srednjobosanski coal basin ranges to 1571 Pa, and the free gas pressure in this coal basin amounts up to 3.75 MPa. The desorption index for coal beds in “Kreka” and “Banoviće” coal basins has negative values, which means that the free gas fraction within the coal beds is negligible, while separation of adsorbed gases is diffuse. The free gas pressure in the mentioned coal basins is below 0.1 MPa. Adsorbed gases within the coal are connected by physical adsorption according to Langmuir’s isothermal adsorption curve. Langmuir’s quantities, for coal bed conditions, ranges as follows: am from 0.826 to 9.52 m3 t–1 pcs, and b from 6.65 10–3 to 0.247 MPa–1. Adsorbed gas within Miocene coal beds contains methane in amounts of 1.49 m3 t–1 čus CH4 andcarbon(IVoxide in amounts of 0.15 m3 t–1 čus CO2. Adsorbed gas within Pliocene coal beds, without methane, dominant is content of carbon(IVoxide.The investigation of the gas content in coal beds of BiH conducted in this article reveal that the coal beds primarily contain methane, while others hydrocarbons such as ethane, ethene, propane, propene and butane are present sporadically in fraction below φ/10–6. Based on the investigation results conducted in this article, simple mathematical forms were obtained for quick calculation of the free gas quantity by measurement of the

  7. 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...... discomfort is a factor limiting bed net use and open a range of architectural possibilities to overcome this limitation. Keywords: Malaria; Bed nets; Africa; Tanzania; The Gambia; Asia; Thailand; Philippines; Airflow; Temperature; Humidity; Climate...... 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...

  8. The underlying reasons for very high levels of bed net use, and higher malaria infection prevalence among bed net users than non-users in the Tanzanian city of Dar es Salaam: a qualitative study.

    Science.gov (United States)

    Msellemu, Daniel; Shemdoe, Aloysia; Makungu, Christina; Mlacha, Yeromini; Kannady, Khadija; Dongus, Stefan; Killeen, Gerry F; Dillip, Angel

    2017-10-23

    Bed nets reduce malaria-related illness and deaths, by forming a protective barrier around people sleeping under them. When impregnated with long-lasting insecticide formulations they also repel or kill mosquitoes attempting to feed upon sleeping humans, and can even suppress entire populations of malaria vectors that feed predominantly upon humans. Nevertheless, an epidemiological study in 2012 demonstrated higher malaria prevalence among bed net users than non-users in urban Dar es Salaam, Tanzania. Focus group discussions were conducted with women from four selected wards of Dar es Salaam city, focusing on four major themes relating to bed net use behaviours: (1) reasons for bed net use, (2) reasons for not using bed nets, (3) stimuli or reminders for people to use a bed net (4) perceived reasons for catching malaria while using a bed net. An analytical method by framework grouping of relevant themes was used address key issues of relevance to the study objectives. Codes were reviewed and grouped into categories and themes. All groups said the main reason for bed net use was protection against malaria. Houses with well-screened windows, with doors that shut properly, and that use insecticidal sprays against mosquitoes, were said not to use bed nets, while frequent attacks from malaria was the main stimulus for people to use bed nets. Various reasons were mentioned as potential reasons that compromise bed net efficacy, the most common of which were: (1) bed net sharing by two or more people, especially if one occupant tends to come to bed late at night, and does not tuck in the net 71%; (2) one person shares the bed but does not use the net, moving it away from the side on which s/he sleeps 68%; (3) ineffective usage habits, called ulalavi, in which a sprawling sleeper either touches the net while sleeping up against it or leaves a limb hanging outside of it 68%. Less common reasons mentioned included: (1) Small bed nets which become un-tucked at night (31%); (2

  9. 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.

  10. [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.

  11. 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

  12. 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

    Reactor fuel rod surface area that is perpendicular to coolant flow direction (+S) i.e. perpendicular to the P creates areas of coolant stagnation leading to increased coolant temperatures resulting in localized changes in fluid properties. Changes in coolant fluid properties caused by minor increases in temperature lead to localized reductions in coolant mass flow rates leading to localized thermal instabilities. Reductions in coolant mass flow rates result in further increases in local temperatures exacerbating changes to coolant fluid properties leading to localized thermal runaway. Unchecked localized thermal runaway leads to localized fuel melting. Reactor designs with randomized flow paths are vulnerable to localized thermal instabilities, localized thermal runaway, and localized fuel melting.

  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. Bronx River bed sediments phosphorus pool and phosphorus compound identification

    Science.gov (United States)

    Wang, J.; Pant, H. K.

    2008-12-01

    Phosphorus (P) transport in the Bronx River degraded water quality, decreased oxygen levels, and resulted in bioaccumulation in sediment potentially resulting in eutrophication, algal blooms and oxygen depletion under certain temperature and pH conditions. The anthropogenic P sources are storm water runoff, raw sewage discharge, fertilizer application in lawn, golf course and New York Botanical Garden; manure from the Bronx zoo; combined sewoverflows (CSO's) from parkway and Hunts Point sewage plant; pollutants from East River. This research was conducted in the urban river system in New York City area, in order to control P source, figure out P transport temporal and spatial variations and the impact on water quality; aimed to regulate P application, sharing data with Bronx River Alliance, EPA, DEP and DEC. The sediment characteristics influence the distribution and bioavailbility of P in the Bronx River. The P sequential extraction gave the quantitative analysis of the P pool, quantifying the inorganic and organic P from the sediments. There were different P pool patterns at the 15 sites, and the substantial amount of inorganic P pool indicated that a large amount P is bioavailable. The 31P- NMR (Nuclear Magnetic Resonance Spectroscopy) technology had been used to identify P species in the 15 sites of the Bronx River, which gave a qualitative analysis on phosphorus transport in the river. The P compounds in the Bronx River bed sediments are mostly glycerophophate (GlyP), nucleoside monophosphates (NMP), polynucleotides (PolyN), and few sites showed the small amount of glucose-6-phosphate (G6P), glycerophosphoethanoamine (GPEA), phosphoenopyruvates (PEP), and inosine monophosphate (IMP). The land use spatial and temporal variations influence local water P levels, P distributions, and P compositions.

  15. 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.

  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. Bed rest attenuates sympathetic and pressor responses to isometric exercise in antigravity leg muscles in humans.

    Science.gov (United States)

    Kamiya, Atsunori; Michikami, Daisaku; Shiozawa, Tomoki; Iwase, Satoshi; Hayano, Junichiro; Kawada, Toru; Sunagawa, Kenji; Mano, Tadaaki

    2004-05-01

    Although spaceflight and bed rest are known to cause muscular atrophy in the antigravity muscles of the legs, the changes in sympathetic and cardiovascular responses to exercises using the atrophied muscles remain unknown. We hypothesized that bed rest would augment sympathetic responses to isometric exercise using antigravity leg muscles in humans. Ten healthy male volunteers were subjected to 14-day 6 degrees head-down bed rest. Before and after bed rest, they performed isometric exercises using leg (plantar flexion) and forearm (handgrip) muscles, followed by 2-min postexercise muscle ischemia (PEMI) that continues to stimulate the muscle metaboreflex. These exercises were sustained to fatigue. We measured muscle sympathetic nerve activity (MSNA) in the contralateral resting leg by microneurography. In both pre- and post-bed-rest exercise tests, exercise intensities were set at 30 and 70% of the maximum voluntary force measured before bed rest. Bed rest attenuated the increase in MSNA in response to fatiguing plantar flexion by approximately 70% at both exercise intensities (both P antigravity leg muscles.

  18. Trpc2-deficient lactating mice exhibit altered brain and behavioral responses to bedding stimuli.

    Science.gov (United States)

    Hasen, Nina S; Gammie, Stephen C

    2011-03-01

    The trpc2 gene encodes an ion channel involved in pheromonal detection and is found in the vomeronasal organ. In tprc2(-/-) knockout (KO) mice, maternal aggression (offspring protection) is impaired and brain Fos expression in females in response to a male are reduced. Here we examine in lactating wild-type (WT) and KO mice behavioral and brain responses to different olfactory/pheromonal cues. Consistent with previous studies, KO dams exhibited decreased maternal aggression and nest building, but we also identified deficits in nighttime nursing and increases in pup weight. When exposed to the bedding tests, WT dams typically ignored clean bedding, but buried male-soiled bedding from unfamiliar males. In contrast, KO dams buried both clean and soiled bedding. Differences in brain Fos expression were found between WT and KO mice in response to either no bedding, clean bedding, or soiled bedding. In the accessory olfactory bulb, a site of pheromonal signal processing, KO mice showed suppressed Fos activation in the anterior mitral layer relative to WT mice in response to clean and soiled bedding. However, in the medial and basolateral amygdala, KO mice showed a robust Fos response to bedding, suggesting that regions of the amygdala canonically associated with pheromonal sensing can be active in the brains of KO mice, despite compromised signaling from the vomeronasal organ. Together, these results provide further insights into the complex ways by which pheromonal signaling regulates the brain and behavior of the maternal female. Copyright © 2010 Elsevier B.V. All rights reserved.

  19. Steam and sodium leak simulation in a fluidized-bed steam generator

    International Nuclear Information System (INIS)

    Vaux, W.G.; Keeton, A.R.; Keairns, D.L.

    1977-01-01

    A fluidized-bed steam generator for the liquid metal fast breeder reactor enhances plant availability and minimizes the probability of a water/sodium reaction. An experimental test program was conceived to assess design criteria and fluidized-bed operation under conditions of water, steam, and sodium leaks. Sodium, steam, and water were leaked into helium-fluidized beds of metal and ceramic particles at 900 F. Test results show the effects of leaks on the heat transfer coefficient, quality of fluidization, leak detection, and cleanup procedures

  20. Production of renewable energy from biomass and waste materials using fluidized bed technologies

    International Nuclear Information System (INIS)

    Rozainee, M.; Rashid, M.; Looi, S.

    2000-01-01

    Malaysian industries generate substantial amount of biomass and waste materials such as wastes from agricultural and wood based industries, sludge waste from waste-water treatment plants and solid waste from municipals. Incinerating these waste materials not only produces renewable energy, but also solving their disposal problems. Fluidized bed combustors are widely used for incinerating these biomass materials. The significant advantages of fluidized bed incineration include simple design, efficient, and ability to reduce air pollution emissions. This paper discusses the opportunities and challenges of producing the green energy from biomass materials using the fluidized bed technologies. (Author)

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

    International Nuclear Information System (INIS)

    Jantzen, C

    2006-01-01

    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 s ign) 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; (3) compressive strength; and (4

  2. Coating and melt induced agglomeration in a poultry litter fired fluidized bed combustor

    International Nuclear Information System (INIS)

    Billen, Pieter; Creemers, Benji; Costa, José; Van Caneghem, Jo; Vandecasteele, Carlo

    2014-01-01

    The combustion of poultry litter, which is rich in phosphorus, in a fluidized bed combustor (FBC) is associated with agglomeration problems, which can lead to bed defluidization and consequent shutdown of the installation. Whereas earlier research indicated coating induced agglomeration as the dominant mechanism for bed material agglomeration, it is shown experimentally in this paper that both coating and melt induced agglomeration occur. Coating induced agglomeration mainly takes place at the walls of the FBC, in the freeboard above the fluidized bed, where at the prevailing temperature the bed particles are partially molten and hence agglomerate. In the ash, P 2 O 5 forms together with CaO thermodynamically stable Ca 3 (PO 4 ) 2 , thus reducing the amount of calcium silicates in the ash. This results in K/Ca silicate mixtures with lower melting points. On the other hand, in-bed agglomeration is caused by thermodynamically unstable, low melting HPO 4 2− and H 2 PO 4 − salts present in the fuel. In the hot FBC these salts may melt, may cause bed particles to stick together and may subsequently react with Ca salts from the bed ash, forming a solid bridge of the stable Ca 3 (PO 4 ) 2 between multiple particles. - Highlights: • Coating induced agglomeration not due to K phosphates, but due to K silicates. • Melt induced agglomeration due to H 2 PO 4 − and HPO 4 2− salts in the fuel. • Wall agglomeration corresponds to coating induced mechanism. • In-bed agglomeration corresponds to melt induced mechanism

  3. Glaciation of Siberia and the problem of massive ice beddings

    Directory of Open Access Journals (Sweden)

    V. S. Sheinkman

    2017-01-01

    Full Text Available As a result of many years of the author’s studies of glaciers and ground ices, a great amount of factual material has been collected for a purpose to analyze a possibility of burying the glaciers in the permafrost zone and to esti‑ mate a time of their stay in such а condition. According to the author’s opinion, the Siberian glaciers were mainly the valley ones; ice sheets were never formed, and any existence of buried glaciers could not be real in the geo‑ logical time scale. However, some researchers still believe that in the Quaternary ice sheets occurred in the North of Siberia, and, in addition, they consider the local massive ice beddings as relics of these sheets. No clear expla‑ nation of the similar origin of such ice structures exists at the present time, so development and variety of this ice could be easier explained by the permafrost genesis. Basing on results of observations carried out in all glacier regions of Siberia, the author concludes that glaciers cannot exist in the form of buried ice for a long time. This is unrealistic even in the North‑East of Siberia, where the absolute minimum temperature is −67.8 °C, and the mean annual air temperature drops below −17 °C. The characteristic feature of the Siberia continental climate is short, but hot summer. In such a situation, the coarse fragmental morainic material, covering glaciers by the layer up to 3 m thick, cannot preserve the underlying ice from melting because the heat penetrates down with the air, liquid precipitation, and the melt water. When glaciers reduce, the dead ice, buried under a moraine, may be preserved in the coldest areas of Siberia for only 100–150 years. Therefore, despite the resemblance of the scarps of the ice bodies having the permafrost or glacial origin, consideration of them as relics of ancient glaciers would be wrong.

  4. 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

  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. Maintenance of an obstruction-forced pool in a gravel-bed channel: streamflow, channel morphology, and sediment transport.

    Science.gov (United States)

    Richard D. Woodsmith; Marwan A. Hassan

    2005-01-01

    Maintenance of pool morphology in a stream channel with a mobile bed requires hydraulic conditions at moderate to high flows that route bed load through the pool as it is delivered from upstream. Through field measurements of discharge, vertical velocity profiles, bed load transport, and streambed scour, fill, and grain-size distribution, we found that maintenance of a...

  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. The flooding phenomenon and its connection with dry-out in boiling particle beds

    International Nuclear Information System (INIS)

    Macbeth, R.V.; Anderson, A.R.

    1986-03-01

    Experimental studies of boiling in particle beds representing reactor core debris have been restricted to very small beds compared with those that may be found in a reactor. The use of air and water to simulate some of the many features of boiling in a particle bed has given results that were inconclusive. The work reported here is that carried out at Winfrith to extend the dryout data to larger particle diameters, and to provide new experimental data which removes earlier doubts, and makes the air-water analogue position much clearer. (U.K.)

  10. Fluidised bed combustion system

    International Nuclear Information System (INIS)

    McKenzie, E.C.

    1976-01-01

    Fluidized bed combustion systems that facilitates the maintenance of the depth of the bed are described. A discharge pipe projects upwardly into the bed so that bed material can flow into its upper end and escape downwardly. The end of the pipe is surrounded by an enclosure and air is discharged into the enclosure so that material will enter the pipe from within the enclosure and have been cooled in the enclosure by the air discharged into it. The walls of the enclosure may themselves be cooled

  11. 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.

  12. 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.

  13. 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...

  14. 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)

  15. Fluid bed dryer and Aeropep solidification system. Amendment 1 to topical report

    International Nuclear Information System (INIS)

    1975-01-01

    Information is presented on interfaces between the aerojet fluid bed dryer and the liquid radwaste system, plant ventilation system, and radioactive solid waste handling system for BWR and PWR type reactors. (U.S.)

  16. 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

  17. Real time test bed development for power system operation, control and cyber security

    Science.gov (United States)

    Reddi, Ram Mohan

    The operation and control of the power system in an efficient way is important in order to keep the system secure, reliable and economical. With advancements in smart grid, several new algorithms have been developed for improved operation and control. These algorithms need to be extensively tested and validated in real time before applying to the real electric power grid. This work focuses on the development of a real time test bed for testing and validating power system control algorithms, hardware devices and cyber security vulnerability. The test bed developed utilizes several hardware components including relays, phasor measurement units, phasor data concentrator, programmable logic controllers and several software tools. Current work also integrates historian for power system monitoring and data archiving. Finally, two different power system test cases are simulated to demonstrate the applications of developed test bed. The developed test bed can also be used for power system education.

  18. Hydrodynamic and thermal modelling of gas-particle flow in fluidized beds

    International Nuclear Information System (INIS)

    Abdelkawi, O.S; Abdalla, A.M.; Atwan, E.F; Abdelmonem, S.A.; Elshazly, K.M.

    2009-01-01

    In this study a mathematical model has been developed to simulate two dimensional fluidized bed with uniform fluidization. The model consists of two sub models for hydrodynamic and thermal behavior of fluidized bed on which a FORTRAN program entitled (NEWFLUIDIZED) is devolved. The program is used to predict the volume fraction of gas and particle phases, the velocity of the two phases, the gas pressure and the temperature distribution for two phases. Also the program calculates the heat transfer coefficient. Besides the program predicts the fluidized bed stability and determines the optimum input gas velocity for fluidized bed to achieve the best thermal behavior. The hydrodynamic model is verified by comparing its results with the computational fluid dynamic code MFIX . While the thermal model was tested and compared by the available previous experimental correlations.The model results show good agreement with MFIX results and the thermal model of the present work confirms Zenz and Gunn equations

  19. 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.

  20. Effects of pressure drop and superficial velocity on the bubbling fluidized bed incinerator.

    Science.gov (United States)

    Wang, Feng-Jehng; Chen, Suming; Lei, Perng-Kwei; Wu, Chung-Hsing

    2007-12-01

    Since performance and operational conditions, such as superficial velocity, pressure drop, particles viodage, and terminal velocity, are difficult to measure on an incinerator, this study used computational fluid dynamics (CFD) to determine numerical solutions. The effects of pressure drop and superficial velocity on a bubbling fluidized bed incinerator (BFBI) were evaluated. Analytical results indicated that simulation models were able to effectively predict the relationship between superficial velocity and pressure drop over bed height in the BFBI. Second, the models in BFBI were simplified to simulate scale-up beds without excessive computation time. Moreover, simulation and experimental results showed that minimum fluidization velocity of the BFBI must be controlled in at 0.188-3.684 m/s and pressure drop was mainly caused by bed particles.

  1. The effects of baffles and gas superficial velocity on a bubble fluidized bed reactor's applications

    International Nuclear Information System (INIS)

    Ghorbanpour, A.; Ghannadi Maragheh, M.; Mallah, M. H.

    2008-01-01

    Baffles are used for decreasing bubbles diameter in order to increase the conversion rate along the bubbling fluidized bed reactors. The appearance of this phenomenon is due to bursting of the bubbles during the pass of bubbles from baffles. In this work, a computerized modeling and simulation have been performed in order to obtain a fundamental knowledge of the influence of the baffles on the bubble diameter and the specific mass transfer area. The height of the bed is 5 meters and its diameter is 0.3 meter. Baffles are located at 1 and 2 meters from the bottom of the bed. A two phase model together with a comprehensive fluid dynamical description of bubbling fluidized is presented. The effects of baffles and gas superficial velocity on the operating behavior of fluidized bed reactors are considered. The results are compared to the previously reported documents, and the experiments which have been carried out. MATLAB software is used in this simulation

  2. 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

  3. Non-intrusive measurement and hydrodynamics characterization of gas–solid fluidized beds: a review

    OpenAIRE

    Sun, Jingyuan; Yan, Yong

    2016-01-01

    Gas-solid fluidization is a well-established technique to suspend or transport particles and has been applied in a variety of industrial processes. Nevertheless, our knowledge of fluidization hydrodynamics is still limited for the design, scale-up and operation optimization of fluidized bed reactors. It is therefore essential to characterize the two-phase flow behaviours in gas-solid fluidized beds and monitor the fluidization processes for control and optimization. A range of non-intrusive t...

  4. Effects of Drawdown and Structures on Bed-Load Transport in Pool 8 Navigation Channel

    National Research Council Canada - National Science Library

    Abraham, David; Hendrickson, Jon

    2003-01-01

    ... of a pool drawdown and structures on bed-load transport in the Pool 8 navigation channel. Work was conducted as part of the Monitoring of Completed Navigation Projects (MCNP) program. BACKGROUND...

  5. 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.

  6. 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

  7. Induced venous pooling and cardiorespiratory responses to exercise after bed rest

    Science.gov (United States)

    Convertino, V. A.; Sandler, H.; Webb, P.; Annis, J. F.

    1982-01-01

    Venous pooling induced by a specially constructed garment is investigated as a possible means for reversing the reduction in maximal oxygen uptake regularly observed following bed rest. Experiments involved a 15-day period of bed rest during which four healthy male subjects, while remaining recumbent in bed, received daily 210-min venous pooling treatments from a reverse gradient garment supplying counterpressure to the torso. Results of exercise testing indicate that while maximal oxygen uptake endurance time and plasma volume were reduced and maximal heart rate increased after bed rest in the control group, those parameters remained essentially unchanged for the group undergoing venous pooling treatment. Results demonstrate the importance of fluid shifts and venous pooling within the cardiovascular system in addition to physical activity to the maintenance of cardiovascular conditioning.

  8. Governing equations for heat and mass transfer in heat-generating porous beds

    International Nuclear Information System (INIS)

    Chawla, T.C.; Pedersen, D.R.; Minkowycz, W.J.

    1985-01-01

    Upon dryout of the bed, the dominant modes of heat transfer are conduction and radiation. Radiation is modeled through the Rosseland approximation. The melting of stainless-steel particulate imbedded in the fuel is modeled by assuming the bed to be a continuum with conduction and radiation as the dominant modes of heat transfer. The molten steel, after it drains to the bottom of the bed, is assumed to disappear into cracks and mortar joints of the MgO bricks. The melting of fuel in the interior of the bed is modeled identically to the steel particulate, except for the bed settling which is more pronounced in the case of fuel melting and is assumed to be instantaneous owing to the significant weight of overlying bed and sodium pool. The molten layer of fuel, as it collects at the bottom of the bed, causes the heatup of the MgO lining to the eutectic temperature (2280 0 C), and the MgO lining begins to dissolve. The density gradient caused by the dissolution of MgO leads to natural convection and mixing in the molten layer. The submerged fuel particulate also begins to dissolve in the molten solution and ultimately leads to the conversion of debris to a molten pool of fuel and MgO. The process of penetration of the MgO lining continues until the mixing process lowers the concentration of fuel in the volume of the pool to the level where the internal heat rate per unit volume is not enough to keep the body of the pool molten and leads to freezing in the cooler part of the pool. As the molten pool reaches a frozen or a quiescent state, the MgO brick lining thickness provided is deemed 'safe' for a given bed loading and the external rate of cooling. (author)

  9. 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.

  10. 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

  11. 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.

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

    Science.gov (United States)

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

    2016-08-20

    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.

  13. 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

  14. 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.

  15. 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_2O_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 slow

  16. Parent-child bed-sharing: The good, the bad, and the burden of evidence.

    Science.gov (United States)

    Mileva-Seitz, Viara R; Bakermans-Kranenburg, Marian J; Battaini, Chiara; Luijk, Maartje P C M

    2017-04-01

    The practice of parent and child sharing a sleeping surface, or 'bed-sharing', is one of the most controversial topics in parenting research. The lay literature has popularized and polarized this debate, offering on one hand claims of dangers, and on the other, of benefits - both physical and psychological - associated with bed-sharing. To address the scientific evidence behind such claims, we systematically reviewed 659 published papers (peer-reviewed, editorial pieces, and commentaries) on the topic of parent-child bed-sharing. Our review offers a narrative walkthrough of the many subdomains of bed-sharing research, including its many correlates (e.g., socioeconomic and cultural factors) and purported risks or outcomes (e.g., sudden infant death syndrome, sleep problems). We found general design limitations and a lack of convincing evidence in the literature, which preclude making strong generalizations. A heat-map based on 98 eligible studies aids the reader to visualize world-wide prevalence in bed-sharing and highlights the need for further research in societies where bed-sharing is the norm. We urge for multiple subfields - anthropology, psychology/psychiatry, and pediatrics - to come together with the aim of understanding infant sleep and how nightly proximity to the parents influences children's social, emotional, and physical development. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Apparatus for controlling fluidized beds

    Science.gov (United States)

    Rehmat, A.G.; Patel, J.G.

    1987-05-12

    An apparatus and process are disclosed 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. 2 figs.

  18. A depositional model for the Taylor coal bed, Martin and Johnson counties, eastern Kentucky

    Science.gov (United States)

    Andrews, W.M.; Hower, J.C.; Ferm, J.C.; Evans, S.D.; Sirek, N.S.; Warrell, M.; Eble, C.F.

    1996-01-01

    This study investigated the Taylor coal bed in Johnson and Martin counties, eastern Kentucky, using field and petrographic techniques to develop a depositional model of the coal bed. Petrography and chemistry of the coal bed were examined. Multiple benches of the Taylor coal bed were correlated over a 10 km distance. Three sites were studied in detail. The coal at the western and eastern sites were relatively thin and split by thick clastic partings. The coal at the central site was the thickest and unsplit. Two major clastic partings are included in the coal bed. Each represents a separate and distinct fluvial splay. The Taylor is interpreted to have developed on a coastal plain with periodic flooding from nearby, structurally-controlled fluvial systems. Doming is unlikely due to the petrographic and chemical trends, which are inconsistent with modern Indonesian models. The depositional history and structural and stratigraphic setting suggest contemporaneous structural influence on thickness and quality of the Taylor coal bed in this area.

  19. 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

    Background: The aim was to test the hypothesis that one week of bed rest will reduce mitochondrial number and expression and activity of oxidative proteins in human skeletal muscle, but that exercise-induced intracellular signaling as well as mRNA and microRNA (miR) responses are maintained after......-legged knee extensor exercise performed before and after bed rest. Results: Maximal oxygen uptake decreased 5% and exercise endurance decreased non-significantly 25% by bed rest. Bed rest reduced skeletal muscle mitochondrial DNA/nuclear DNA content 15%, hexokinase II and sirtuin 1 protein content ~45%, 3...... 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...

  20. 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.

  1. 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.

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

    International Nuclear Information System (INIS)

    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

  3. 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.

  4. The research and development of pressurized ash agglomerating fluidized bed coal gasification

    Energy Technology Data Exchange (ETDEWEB)

    Fang Yitian; Wu Jinhu; Chen Hanshi [Chinese Academy of Sciences, Taiyuan (China). Institute of Coal Chemistry

    1999-11-01

    Coal gasification tests in a pressurized ash agglomeration fluidized bed coal gasifier were carried out. The effects of pressure and temperature on the gasification capacity, carbon conversion, carbon content in discharged ash and gas composition were investigated. Gasification capacity was shown to be in direct proportion to operation pressure. Tests of hot gas dedusting using a moving granular bed were also carried out. 3 refs., 6 figs., 2 tabs.

  5. 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...

  6. Accumulation of Arsenic and Mercury in Different Bio-bed Padding Materials

    Directory of Open Access Journals (Sweden)

    LIU Tian-yu

    2016-07-01

    Full Text Available In order to study the accumulation and distribution of As, Hg in different bio-bed padding materials while implementing bio-bed raising method, three kinds of bio-bed padding materials were well designed, which consisted of sawdust(S, sawdust + rice husk(SR and sawdust + rice husk + straw(SRS. For a year and a half, the contents of As, Hg at different depth were measured when four groups of fattening pig breeding had finished to analyze the accumulation and distribution of As, Hg in different bio-bed padding materials, which could provide a theoretical basis for follow-up application of bio-bed padding materials in agriculture. The results showed that, the accumulation of As and Hg, at different levels, occurred during four pig-raising cycles. When 4 groups of fattening pig breeding finished, the largest accumulation of As and Hg occurred in SRS bio-beds, respectively reached 1921.7 mg per sty and 21.1 mg per sty. The As and Hg contents of S, SR,SRS were 2.921, 2.190, 2.621 mg·kg-1 and 0.048, 0.036, 0.042 mg·kg-1, respectively, which met the China's Organic Fertilizer Agriculture Standards(NY 525-2012, and Farmland Environmental Quality Evaluation Standards For Edible Agricultural Products(HJ/T 332-2006.

  7. 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.

  8. 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.

  9. Use of electric bedding devices and risk of breast cancer in African-American women.

    Science.gov (United States)

    Zhu, Kangmin; Hunter, Sandra; Payne-Wilks, Kathleen; Roland, Chanel L; Forbes, Digna S

    2003-10-15

    In this case-control study, the authors aimed to examine whether use of an electric bedding device increased breast cancer risk in African-American women. Cases were 304 African-American patients diagnosed with breast cancer during 1995-1998 who were aged 20-64 years and lived in one of three Tennessee counties. Controls were 305 African-American women without breast cancer who were selected through random digit dialing and frequency-matched to cases by age and county. Information on the use of an electric blanket or heated water bed and other risk factors was collected through telephone interviews. Breast cancer risk associated with use of an electric bedding device increased with the number of years of use, the number of seasons of use, and the length of time of use during sleep. When women who used an electric bedding device for more than 6 months per year (and therefore were more likely to have used a heated water bed, which generates lower magnetic fields) were excluded, the corresponding dose-response relations were more striking. Similar trends in dose response were shown in both premenopausal and postmenopausal women and for both estrogen receptor-positive and estrogen receptor-negative tumors. The use of electric bedding devices may increase breast cancer risk in African-American women aged 20-64 years. Such an association might not vary substantially by menopausal status or estrogen receptor status.

  10. BedMachine v3: Complete Bed Topography and Ocean Bathymetry Mapping of Greenland From Multibeam Echo Sounding Combined With Mass Conservation

    DEFF Research Database (Denmark)

    Morlighem, M.; Williams, C. N.; Rignot, E.

    2017-01-01

    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...

  11. 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.

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

    Directory of Open Access Journals (Sweden)

    Mette Mogensen

    2010-10-01

    Full Text Available Mette Mogensen1, Gregor BE Jemec21Department of Dermatology, Gentofte Hospital, Hellerup, Denmark; 2Department of Dermatology, Roskilde Hospital, Health Sciences Faculty, University of Copenhagen, Roskilde, DenmarkIntroduction: 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.Methods: A narrative review of the literature was conducted based on both PubMed and Medline searches and on literature review of the retrieved papers.Results: 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.Discussion: 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.Keywords: tanning beds, skin cancers, melanoma, nonmelanoma

  13. 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

  14. 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.

  15. Survival of bacteria of laboratory animal origin on cage bedding and inactivation by hydrogen peroxide vapour.

    Science.gov (United States)

    Benga, Laurentiu; Benten, W Peter M; Engelhardt, Eva; Gougoula, Christina; Schulze-Röbbecke, Roland; Sager, Martin

    2017-08-01

    This study aims to determine the ability of laboratory animal bacteria to resist desiccation and inactivation by hydrogen peroxide vapour (HPV) on paper bedding pieces. Bedding pieces were saturated with bacterial suspensions in water or 2% (w/v) bovine serum albumin (BSA) in water, and held in a mouse facility. Viable counts showed variable survival rates over time for the bacterial species used ([ Pasteurella] pneumotropica, Muribacter muris, Pseudomonas aeruginosa, Acinetobacter redioresistens, Escherichia coli, Klebsiella oxytoca, Bordetella bronchiseptica, Bordetella hinzii, Enterococcus faecalis, β-haemolytic Streptococcus spp., Staphylococcus aureus and Staphylococcus xylosus). Overall, BSA increased bacterial survival in the bedding pieces. The survival rates of Bacillus safensis were not influenced by BSA but depended on sporulation. When bedding pieces and Petri dishes inoculated with E. coli, P. aeruginosa and S. aureus were subjected to HPV disinfection, all bacterial species on the bedding pieces inoculated with bacterial suspensions in water were readily inactivated. By contrast, S. aureus and P. aeruginosa, but not E. coli cells survived HPV treatment in high numbers when inoculated on bedding pieces as a BSA suspension. Notably, all three bacterial species were readily inactivated by HPV even in the presence of BSA when smeared on smooth surfaces. In conclusion, the suspension medium and the carrier can influence the environmental survival and susceptibility of bacterial species to HPV. Our results may help to develop standard protocols that can be used to ensure the microbiological quality of experimental rodent housing.

  16. 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.

  17. Body dissatisfaction and socio-cultural factors in women with and without BED: their relation with eating psychopathology.

    Science.gov (United States)

    Bautista-Díaz, M L; Franco-Paredes, K; Mancilla-Díaz, J M; Alvarez-Rayón, G; López-Aguilar, X; Ocampo Téllez-Girón, T; Soto-González, Y

    2012-06-01

    The goal of the present study was to assess the role of body dissatisfaction and socio-cultural factors on eating psychopathology in women with Binge Eating Disorder (BED) and women without BED. Seventy obese women consecutively evaluated participated: 35 with BED and 35 without BED who attended for the first time in a weight loss program. All participants completed a battery of questionnaires, including: Body Shape Questionnaire, Questionnaire of Influences on the Aesthetic Body Shape Model, Questionnaire on Eating and Weight Patterns, Three Factor Eating Questionnaire, and they were interviewed with the Interview for the Diagnosis of Eating Disorder-IV. The Body Mass Index, Waist-to-Hip Ratio and Body Fat were calculated. The results showed that 21% of obese women who participated in a weight reduction program met BED criteria. The scores of body dissatisfaction, influences of socio-cultural factors and eating psychopathology were higher in women with BED compared with women without BED. In the same way, significantly stronger correlations were found among influences of socio-cultural factors, specifically, influence of advertisement, social relations and eating psychopathology in women with BED than women without BED. It is concluded that the high body dissatisfaction as well as stronger associations among influence of socio-cultural factors and eating psychopathology could play an important role in women with BED.

  18. Fluidized bed drying characteristics and modeling of ginger ( zingiber officinale) slices

    Science.gov (United States)

    Parlak, Nezaket

    2015-08-01

    In this study fluidized bed drying characteristics of ginger have been investigated. The effects of the fluidizing air temperature, velocity, humidity and bed height on the drying performance of ginger slices have been found. The experimental moisture loss data of ginger slices has been fitted to the eight thin layer drying models. Two-term model drying model has shown a better fit to the experimental data with R2 of 0.998 as compared to others.

  19. Recycling manure as cow bedding: potential benefits and risks for UK dairy farms

    OpenAIRE

    Lech, Katharine. A.; Archer, Simon C.; Breen, James E.; Green, Martin J.; Ohnstad, Ian C.; Tuer, Sally; Bradley, Andrew J.

    2015-01-01

    Material obtained from physical separation of slurry (recycled manure solids; RMS) has been used as bedding for dairy cows in dry climates in the US since the 1970s. Relatively recently, the technical ability to produce drier material has led to adoption of the practice in Europe under different climatic conditions. This review collates the evidence available on benefits and risks of using RMS bedding on dairy farms, with a European context in mind. There was less evidence than expected for a...

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

    OpenAIRE

    Syed Farman Ali Shah; Aziza Aftab; Noorullah Soomro; Mir Shah Nawaz; Kambiz Vafai

    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 c...

  1. 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."

  2. 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

  3. The Space Station Module Power Management and Distribution automation test bed

    Science.gov (United States)

    Lollar, Louis F.

    1991-01-01

    The Space Station Module Power Management And Distribution (SSM/PMAD) automation test bed project was begun at NASA/Marshall Space Flight Center (MSFC) in the mid-1980s to develop an autonomous, user-supportive power management and distribution test bed simulating the Space Station Freedom Hab/Lab modules. As the test bed has matured, many new technologies and projects have been added. The author focuses on three primary areas. The first area is the overall accomplishments of the test bed itself. These include a much-improved user interface, a more efficient expert system scheduler, improved communication among the three expert systems, and initial work on adding intermediate levels of autonomy. The second area is the addition of a more realistic power source to the SSM/PMAD test bed; this project is called the Large Autonomous Spacecraft Electrical Power System (LASEPS). The third area is the completion of a virtual link between the SSM/PMAD test bed at MSFC and the Autonomous Power Expert at Lewis Research Center.

  4. 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

  5. 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

  6. 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

  7. Numerical simulation and experimental verification of gas flow through packed beds

    International Nuclear Information System (INIS)

    Natarajan, S.; Zhang, C.; Briens, C.

    2003-01-01

    This work is concerned with finding out an effective way of eliminating oxygen from a packed bed of monomer particles. This process finds application in industries involved in the manufacture of Nylon12. In the manufacture of the polymer Nylon12, the polymerization reaction is hindered by the presence of oxygen. Therefore, the main objective of this study is to get rid of the oxygen by injecting nitrogen to displace the oxygen from the voids in-between the monomer particles before they are introduced into the polymerization reactor. This work involves the numerical simulation and experimental verification of the flow in a packed bed. In addition, a parametric study is carried out for the parameters such as the number of injectors, the radial position of injectors, and the position of the injectors along the circumference of the packed bed to find out the best possible combination for effective elimination of the oxygen. Nitrogen does not interact with the monomer particles and hence there is no chemical reaction involved in this process. The nitrogen is introduced into the packed bed at a flow rate which will keep the superficial velocity well below the minimum fluidization velocity of the monomer particles. The packed bed will be modeled using a porous medium approach available in the commercial computational fluid dynamics (CFD) software FLUENT. The fluid flow inside the packed bed will be a multicomponent gas flow through a porous medium. The simulation results are validated by comparing with the experimental results. (author)

  8. 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...... be allocated to researching the causes and effects of bed shortages, with the aim of creating greater interest in exploring new methods to avoid or reduce bed shortages....

  9. Effects of Bed Rest on Conduction Velocity of the Triceps Surae Stretch Reflex and Postural Control

    Science.gov (United States)

    Reschke, M. F.; Wood, S. J.; Cerisano, J. M.; Kofman, I. S.; Fisher, E. A.; Esteves, J. T.; Taylor, L. C.; DeDios, Y. E.; Harm, D. L.

    2011-01-01

    Despite rigorous exercise and nutritional management during space missions, astronauts returning from microgravity exhibit neuromuscular deficits and a significant loss in muscle mass in the postural muscles of the lower leg. Similar changes in the postural muscles occur in subjects participating in long-duration bed rest studies. These adaptive muscle changes manifest as a reduction in reflex conduction velocity during head-down bed rest. Because the stretch reflex encompasses both the peripheral (muscle spindle and nerve axon) and central (spinal synapse) components involved in adaptation to calf muscle unloading, it may be used to provide feedback on the general condition of neuromuscular function, and might be used to evaluate the effectiveness of countermeasures aimed at preserving muscle mass and function during periods of unloading. Stretch reflexes were measured on 18 control subjects who spent 60 to 90 days in continuous 6 deg head-down bed rest. Using a motorized system capable of rotating the foot around the ankle joint (dorsiflexion) through an angle of 10 degrees at a peak velocity of about 250 deg/sec, a stretch reflex was recorded from the subject's left triceps surae muscle group. Using surface electromyography, about 300 reflex responses were obtained and ensemble-averaged on 3 separate days before bed rest, 3 to 4 times in bed, and 3 times after bed rest. The averaged responses for each test day were examined for reflex latency and conduction velocity (CV) across gender. Computerized posturography was also conducted on these same subjects before and after bed rest as part of the standard measures. Peak-to-peak sway was measured during Sensory Organization Tests (SOTs) to evaluate changes in the ability to effectively use or suppress visual, vestibular, and proprioceptive information for postural control. Although no gender differences were found, a significant increase in reflex latency and a significant decrease in CV were observed during the bed

  10. 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'')

  11. 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

  12. 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

  13. Getting Rid of Bed Bugs

    Science.gov (United States)

    ... Directory Planning, Budget and Results Jobs and Internships Headquarters Offices Regional Offices Labs and Research Centers Bed ... to be careful in how you select a company. Related Information Collaborative Strategy on Bed Bugs - highlights ...

  14. 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....

  15. 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

  16. Experimental and Computational Study of Multiphase Flow Hydrodynamics in 2D Trickle Bed Reactors

    Science.gov (United States)

    Nadeem, H.; Ben Salem, I.; Kurnia, J. C.; Rabbani, S.; Shamim, T.; Sassi, M.

    2014-12-01

    Trickle bed reactors are largely used in the refining processes. Co-current heavy oil and hydrogen gas flow downward on catalytic particle bed. Fine particles in the heavy oil and/or soot formed by the exothermic catalytic reactions deposit on the bed and clog the flow channels. This work is funded by the refining company of Abu Dhabi and aims at mitigating pressure buildup due to fine deposition in the TBR. In this work, we focus on meso-scale experimental and computational investigations of the interplay between flow regimes and the various parameters that affect them. A 2D experimental apparatus has been built to investigate the flow regimes with an average pore diameter close to the values encountered in trickle beds. A parametric study is done for the development of flow regimes and the transition between them when the geometry and arrangement of the particles within the porous medium are varied. Liquid and gas flow velocities have also been varied to capture the different flow regimes. Real time images of the multiphase flow are captured using a high speed camera, which were then used to characterize the transition between the different flow regimes. A diffused light source was used behind the 2D Trickle Bed Reactor to enhance visualizations. Experimental data shows very good agreement with the published literature. The computational study focuses on the hydrodynamics of multiphase flow and to identify the flow regime developed inside TBRs using the ANSYS Fluent Software package. Multiphase flow inside TBRs is investigated using the "discrete particle" approach together with Volume of Fluid (VoF) multiphase flow modeling. The effect of the bed particle diameter, spacing, and arrangement are presented that may be used to provide guidelines for designing trickle bed reactors.

  17. Experimental study and modelling of pressure losses during reflooding of a debris beds

    International Nuclear Information System (INIS)

    Clavier, Remi

    2015-01-01

    This work deals with single and two-phase flow pressure losses in porous media. The aim is to improve understanding and modeling of momentum transfer inside particle beds, in relation with nuclear safety issues concerning the reflooding of debris beds during severe nuclear accidents. Indeed, the degradation of the core during such accidents can lead to the collapse of the fuel assemblies, and to the formation of a debris bed, which can be described as a hot porous medium. This thesis is included in a nuclear safety research project on coolability of debris beds during reflooding sequences. An experimental study of single and two-phase cold-flow pressure losses in particle beds is proposed. The geometrical characteristics of the debris and the hydrodynamic conditions are representative of the real case, in terms of granulometry, particle shapes, and flow velocities. The new data constitute an important contribution. In particular, they contain pressure losses and void fraction measurements in two-phase air-water flows with non-zero liquid Reynolds numbers, which did not exist before. Predictive models for pressure losses in single and two-phase flow through particle beds have been established from experimental data. Their structures are based on macroscopic equations obtained from the volume averaging of local conservation equations. Single-phase flow pressure losses can be described by a Darcy-Forchheimer law with a quadratic correction, in terms of filtration velocity, with a better-than-10 % precision. Numerical study of single-phase flows through porous media shows that this correlation is valid for disordered smooth particle beds. Two-phase flow pressure losses are described using a generalized Darcy-Forchheimer structure, involving inertial and cross flow terms. A new model is proposed and compared to the experimental data and to the usual models used in severe accident simulation codes. (author)

  18. 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.

  19. 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.

  20. 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.

  1. 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

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

    Energy Technology Data Exchange (ETDEWEB)

    Blacker, P T; McLain, D R [Reactor Development Division, Atomic Energy Establishment, Winfrith, Dorchester, Dorset (United Kingdom)

    1962-04-15

    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{sup 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.

  3. Role of hydraulic retention time and granular medium in microbial removal in tertiary treatment reed beds.

    Science.gov (United States)

    García, Joan; Vivar, Joan; Aromir, Maria; Mujeriego, Rafael

    2003-06-01

    The main objective of this paper is to evaluate the role of hydraulic retention time (HRT) and granular medium in faecal coliform (FC) and somatic coliphage (SC) removal in tertiary reed beds. Experiments were carried out in a pilot plant with four parallel reed beds (horizontal subsurface flow constructed wetlands), each one containing a different type of granular medium. This pilot plant is located in a wastewater treatment plant in Montcada i Reixac, near Barcelona, in northeastern Spain. The microbial inactivation ratios obtained in the different beds are compared as a function of three selected HRTs. Secondary effluent from the wastewater treatment plant was used as the influent of the pilot system. The microbial inactivation ratio ranged between 0.1 and 2.7 log-units for FC and from 0.5 to 1.7 log-units for SC in beds with coarser granular material (5-25mm), while it ranged between 0.7 and 3.4 log-units for FC and from 0.9 to 2.6 log-units for SC in the bed with finer material (2-13mm). HRT and granular medium are both key factors in microbial removal in the tertiary reed beds. The microbial inactivation ratio rises as the HRT increases until it reaches a saturation value (in general at an HRT of 3 days). The value of the microbial inactivation ratio at the saturation level depends on the granular medium contained in the bed. The specific surface area necessary to reach 2-3 log-units of FC and SC is approximately 3m(2)/person-equivalent.

  4. Persistence of exponential bed thickness distributions in the stratigraphic record: Experiments and theory

    Science.gov (United States)

    Straub, K. M.; Ganti, V. K.; Paola, C.; Foufoula-Georgiou, E.

    2010-12-01

    Stratigraphy preserved in alluvial basins houses the most complete record of information necessary to reconstruct past environmental conditions. Indeed, the character of the sedimentary record is inextricably related to the surface processes that formed it. In this presentation we explore how the signals of surface processes are recorded in stratigraphy through the use of physical and numerical experiments. We focus on linking surface processes to stratigraphy in 1D by quantifying the probability distributions of processes that govern the evolution of depositional systems to the probability distribution of preserved bed thicknesses. In this study we define a bed as a package of sediment bounded above and below by erosional surfaces. In a companion presentation we document heavy-tailed statistics of erosion and deposition from high-resolution temporal elevation data recorded during a controlled physical experiment. However, the heavy tails in the magnitudes of erosional and depositional events are not preserved in the experimental stratigraphy. Similar to many bed thickness distributions reported in field studies we find that an exponential distribution adequately describes the thicknesses of beds preserved in our experiment. We explore the generation of exponential bed thickness distributions from heavy-tailed surface statistics using 1D numerical models. These models indicate that when the full distribution of elevation fluctuations (both erosional and depositional events) is symmetrical, the resulting distribution of bed thicknesses is exponential in form. Finally, we illustrate that a predictable relationship exists between the coefficient of variation of surface elevation fluctuations and the scale-parameter of the resulting exponential distribution of bed thicknesses.

  5. 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.

  6. 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...

  7. The Devil is in the Details: Using X-Ray Computed Tomography to Develop Accurate 3D Grain Characteristics and Bed Structure Metrics for Gravel Bed Rivers

    Science.gov (United States)

    Voepel, H.; Hodge, R. A.; Leyland, J.; Sear, D. A.; Ahmed, S. I.

    2014-12-01

    Uncertainty for bedload estimates in gravel bed rivers is largely driven by our inability to characterize the arrangement and orientation of the sediment grains within the bed. The characteristics of the surface structure are produced by the water working of grains, which leads to structural differences in bedforms through differential patterns of grain sorting, packing, imbrication, mortaring and degree of bed armoring. Until recently the technical and logistical difficulties of characterizing the arrangement of sediment in 3D have prohibited a full understanding of how grains interact with stream flow and the feedback mechanisms that exist. Micro-focus X-ray CT has been used for non-destructive 3D imaging of grains within a series of intact sections of river bed taken from key morphological units (see Figure 1). Volume, center of mass, points of contact, protrusion and spatial orientation of individual surface grains are derived from these 3D images, which in turn, facilitates estimates of 3D static force properties at the grain-scale such as pivoting angles, buoyancy and gravity forces, and grain exposure. By aggregating representative samples of grain-scale properties of localized interacting sediment into overall metrics, we can compare and contrast bed stability at a macro-scale with respect to stream bed morphology. Understanding differences in bed stability through representative metrics derived at the grain-scale will ultimately lead to improved bedload estimates with reduced uncertainty and increased understanding of interactions between grain-scale properties on channel morphology. Figure 1. CT-Scans of a water worked gravel-filled pot. a. 3D rendered scan showing the outer mesh, and b. the same pot with the mesh removed. c. vertical change in porosity of the gravels sampled in 5mm volumes. Values are typical of those measured in the field and lab. d. 2-D slices through the gravels at 20% depth from surface (porosity = 0.35), and e. 75% depth from

  8. Introducing DRG-based financing in Hungary : a study into the relationship between supply of hospital beds and use of these beds under changing institutional circumstances

    NARCIS (Netherlands)

    Kroneman, Madelon W.; Nagy, Júlia

    2001-01-01

    Most hospital reforms carried out in Europe over the past few decades concern the supply of hospital beds and hospital financing systems. In Hungary, financing was not tied to hospital input or output until a Diagnosis-Related-Group system was introduced. This change provided an opportunity to study

  9. Introducing DRG-based financing in Hungary: a study into the relationship between supply of hopsital beds and use of these beds under changing instituonal circumstances.

    NARCIS (Netherlands)

    Kroneman, M.; Nagy, J.

    2001-01-01

    Most hospital reforms carried out in Europe over the past few decades concern the supply of hospital beds and hospital financing systems. In Hungary, financing was not tied to hospital input or output until a Diagnosis-Related-Group system was introduced. This change provided an opportunity to study

  10. [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.

  11. 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

  12. 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.

  13. Insecticide resistance and resistance mechanisms in bed bugs, Cimex spp. (Hemiptera: Cimicidae).

    Science.gov (United States)

    Dang, Kai; Doggett, Stephen L; Veera Singham, G; Lee, Chow-Yang

    2017-06-29

    The worldwide resurgence of bed bugs [both Cimex lectularius L. and Cimex hemipterus (F.)] over the past two decades is believed in large part to be due to the development of insecticide resistance. The transcriptomic and genomic studies since 2010, as well as morphological, biochemical and behavioral studies, have helped insecticide resistance research on bed bugs. Multiple resistance mechanisms, including penetration resistance through thickening or remodelling of the cuticle, metabolic resistance by increased activities of detoxification enzymes (e.g. cytochrome P450 monooxygenases and esterases), and knockdown resistance by kdr mutations, have been experimentally identified as conferring insecticide resistance in bed bugs. Other candidate resistance mechanisms, including behavioral resistance, some types of physiological resistance (e.g. increasing activities of esterases by point mutations, glutathione S-transferase, target site insensitivity including altered AChEs, GABA receptor insensitivity and altered nAChRs), symbiont-mediated resistance and other potential, yet undiscovered mechanisms may exist. This article reviews recent studies of resistance mechanisms and the genes governing insecticide resistance, potential candidate resistance mechanisms, and methods of monitoring insecticide resistance in bed bugs. This article provides an insight into the knowledge essential for the development of both insecticide resistance management (IRM) and integrated pest management (IPM) strategies for successful bed bug management.

  14. 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.

  15. 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)

  16. 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

  17. Adsorption of ciprofloxacin and norfloxacin from aqueous solution onto granular activated carbon in fixed bed column.

    Science.gov (United States)

    Darweesh, Teeba M; Ahmed, Muthanna J

    2017-04-01

    Carbonization of Phoenix dactylifera L stones followed by microwave K 2 CO 3 activation was adopted for preparation of granular activated carbon (KAC). High yield and favorable pore characteristics in terms of surface area and pore volume were reported for KAC as follows: 44%, 852m 2 /g, and 0.671cm 3 /g, respectively. The application of KAC as adsorbent for attraction of ciprofloxacin (CIP) and norfloxacin (NOR) was investigated using fixed bed systems. The effect of flow rate (0.5-1.5ml/min), bed height (15-25cm), and initial drug concentration (75-225mg/l) on the behavior of breakthrough curves was explained. The fixed bed analysis showed the better correlation of breakthrough data by both Thomas and Yoon-Nelson models. Inlet drug concentration was of greatest effect on breakthrough data compared to other fixed bed variables. Experimental and calculated breakthrough data were obtained for CIP and NOR adsorption on KAC, thus being important for design of fixed bed column. Copyright © 2016 Elsevier Inc. All rights reserved.

  18. Experimental and theoretical study of large scale debris bed reflood in the PEARL facility

    Energy Technology Data Exchange (ETDEWEB)

    Chikhi, Nourdine, E-mail: nourdine.chikhi@irsn.fr; Fichot, F.

    2017-02-15

    Highlights: • Five reflooding tests have been carried out with an experimental bed, 500 mm in height and 500 mm in diameter, made of 4 mm stainless steel balls. • For the first time, such a large bed was heated practically homogenously. • The quench front velocity was determined according to thermocouple measurements inside the bed. • An analytical model, assuming a quasi-steady progression of the quench front, allows to predict the conversion ratio in most cases. • It appears that the efficiency of cooling can be increased only up to a certain limit when increasing the inlet water flow rate. - Abstract: During a severe accident in a nuclear power plant, the degradation of fuel rods and melting of materials lead to the accumulation of core materials, which are commonly, called “debris beds”. To stop core degradation and avoid the reactor vessel rupture, the main accident management procedure consists in injecting water. In the case of debris bed, the reflooding models used for Loss of Coolant Accident are not applicable. The IRSN has launched an experimental program on debris bed reflooding to develop new models and to validate severe accident codes. The PEARL facility has been designed to perform, for the first time, the reflooding of large scale debris bed (Ø540 mm, h = 500 mm and 500 kg of steel debris) in a pressurized containment. The bed is heated by means of an induction system. A specific instrumentation has been developed to measure the debris bed temperature, pressure drop inside the bed and the steam flow rate during the reflooding. In this paper, the results of the first integral reflooding tests performed in the PEARL facility at atmospheric pressure up to 700 °C are presented. Focus is made on the quench front propagation and on the steam flow rate during reflooding. The effect of water injection flow rate, debris initial temperature and residual power are also discussed. Finally, an analytical model providing the steam flow rate and

  19. 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.

  20. 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.

  1. 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.

  2. Comparing ownership and use of bed nets at two sites with differential malaria transmission in western Kenya.

    Science.gov (United States)

    Ernst, Kacey C; Hayden, Mary H; Olsen, Heather; Cavanaugh, Jamie L; Ruberto, Irene; Agawo, Maurice; Munga, Stephen

    2016-04-14

    Challenges persist in ensuring access to and optimal use of long-lasting, insecticidal bed nets (LLINs). Factors associated with ownership and use may differ depending on the history of malaria and prevention control efforts in a specific region. Understanding how the cultural and social-environmental context of bed net use may differ between high- and low-risk regions is important when identifying solutions to improve uptake and appropriate use. Community forums and a household, cross-sectional survey were used to collect information on factors related to bed net ownership and use in western Kenya. Sites with disparate levels of transmission were selected, including an endemic lowland area, Miwani, and a highland epidemic-prone area, Kapkangani. Analysis of ownership was stratified by site. A combined site analysis was conducted to examine factors associated with use of all available bed nets. Logistic regression modelling was used to determine factors associated with ownership and use of owned bed nets. Access to bed nets as the leading barrier to their use was identified in community forums and cross-sectional surveys. While disuse of available bed nets was discussed in the forums, it was a relatively rare occurrence in both sites. Factors associated with ownership varied by site. Education, perceived risk of malaria and knowledge of individuals who had died of malaria were associated with higher bed net ownership in the highlands, while in the lowlands individuals reporting it was easy to get a bed net were more likely to own one. A combined site analysis indicated that not using an available bed net was associated with the attitudes that taking malaria drugs is easier than using a bed net and that use of a bed net will not prevent malaria. In addition, individuals with an unused bed net in the household were more likely to indicate that bed nets are difficult to use, that purchased bed nets are better than freely distributed ones, and that bed nets should only

  3. Identification and Characterization of Trichoderma Species Damaging Shiitake Mushroom Bed-Logs Infested by Camptomyia Pest.

    Science.gov (United States)

    Kim, Jun Young; Kwon, Hyuk Woo; Yun, Yeo Hong; Kim, Seong Hwan

    2016-05-28

    The shiitake mushroom industry has suffered from Camptomyia (gall midges) pest, which feeds on the mycelium of shiitake mushroom during its cultivation. It has been postulated that fungal damage of shiitake bed-logs is associated with infestation by the insect pest, but this is not well understood. To understand the fungal damage associated with Camptomyia pest, various Trichoderma species were isolated, identified, and characterized. In addition to two previously known Trichoderma species, T. citrinoviride and T. deliquescens, two other Trichoderma species, T. harzianum and T. atroviride, were newly identified from the pestinfested bed-log samples obtained at three mushroom farms in Cheonan, Korea. Among these four species, T. harzianum was the most evident. The results of a chromogenic media-based assay for extracellular enzymes showed that these four species have the ability to produce amylase, carboxyl-methyl cellulase, avicelase, pectinase, and β-glucosidase, thus indicating that they can degrade wood components. A dual culture assay on PDA indicated that T. harzianum, T. atroviride, and T. citrinoviride were antagonistic against the mycelial growth of a shiitake strain (Lentinula edodes). Inoculation tests on shiitake bed-logs revealed that all four species were able to damage the wood of bed-logs. Our results provide evidence that the four green mold species are the causal agents involved in fungal damage of shiitake bed-logs infested by Camptomyia pest.

  4. 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.

  5. Coupling fine particle and bedload transport in gravel-bedded streams

    Science.gov (United States)

    Park, Jungsu; Hunt, James R.

    2017-09-01

    Fine particles in the silt- and clay-size range are important determinants of surface water quality. Since fine particle loading rates are not unique functions of stream discharge this limits the utility of the available models for water quality assessment. Data from 38 minimally developed watersheds within the United States Geological Survey stream gauging network in California, USA reveal three lines of evidence that fine particle release is coupled with bedload transport. First, there is a transition in fine particle loading rate as a function of discharge for gravel-bedded sediments that does not appear when the sediment bed is composed of sand, cobbles, boulders, or bedrock. Second, the discharge at the transition in the loading rate is correlated with the initiation of gravel mobilization. Third, high frequency particle concentration and discharge data are dominated by clockwise hysteresis where rising limb discharges generally have higher concentrations than falling limb discharges. These three observations across multiple watersheds lead to a conceptual model that fine particles accumulate within the sediment bed at discharges less than the transition and then the gravel bed fluidizes with fine particle release at discharges above the transition discharge. While these observations were individually recognized in the literature, this analysis provides a consistent conceptual model based on the coupling of fine particle dynamics with filtration at low discharges and gravel bed fluidization at higher discharges.

  6. 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.

  7. Effects of Surface and Subsurface Bed Material Composition on Gravel Transport and Flow Competence Relations—Possibilities for Prediction

    Science.gov (United States)

    Bunte, K.; Abt, S. R.; Swingle, K. W.; Cenderelli, D. A.; Gaeuman, D. A.

    2014-12-01

    Bedload transport and flow competence relations are difficult to predict in coarse-bedded steep streams where widely differing sediment supply, bed stability, and complex flow hydraulics greatly affect amounts and sizes of transported gravel particles. This study explains how properties of bed material surface and subsurface size distributions are directly related to gravel transport and may be used for prediction of gravel transport and flow competence relations. Gravel transport, flow competence, and bed material size were measured in step-pool and plane-bed streams. Power functions were fitted to gravel transport QB=aQb and flow competence Dmax=cQd relations; Q is water discharge. Frequency distributions of surface FDsurf and subsurface FDsub bed material were likewise described by power functions FDsurf=hD j and FDsub=kDm fitted over six 0.5-phi size classes within 4 to 22.4 mm. Those gravel sizes are typically mobile even in moderate floods. Study results show that steeper subsurface bed material size distributions lead to steeper gravel transport and flow competence relations, whereas larger amounts of sediment contained in those 6 size bedmaterial classes (larger h and k) flatten the relations. Similarly, steeper surface size distributions decrease the coefficients of the gravel transport and flow competence relations, whereas larger amounts of sediment within the six bed material classes increase the intercepts of gravel transport and flow competence relations. Those relations are likely causative in streams where bedload stems almost entirely from the channel bed as opposed to direct (unworked) contributions from hillslopes and tributaries. The exponent of the subsurface bed material distribution m predicted the gravel transport exponent b with r2 near 0.7 and flow competence exponent d with r2 near 0.5. The intercept of bed surface distributions h increased the intercept a of gravel transport and c of the flow competence relations with r2 near 0.6.

  8. 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.

  9. 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.

  10. Lewis pressurized, fluidized-bed combustion program. Data and calculated results

    Science.gov (United States)

    Rollbuhler, R. J.

    1982-03-01

    A 200 kilowatt (thermal), pressurized, fluidized bed (PFB) reactor and research test facility were designed, constructed, and operated. The facility was established to assess and evaluate the effect of PFB hot gas effluent on aircraft turbine engine materials that may have applications in stationary powerplant turbogenerators. The facility was intended for research and development work and was designed to operate over a wide range of conditions. These conditions included the type and rate of consumption of fuel (e.g., coal) and sulfur reacting sorbent material: the ratio of feed fuel to sorbent material; the ratio of feed fuel to combustion airflow; the depth of the fluidized reaction bed; the temperature and pressure in the reaction bed; and the type of test unit that was exposed to the combustion exhaust gases.

  11. Fundamental Study of Bed Bath Technique : Subjective and Objective Evaluations of Epidermal Effects of Bed Bathing Using Bar Soap and Water-Dissolved Liquid Soap

    OpenAIRE

    月田, 佳寿美; 竹田, 千佐子; 長谷川, 智子; 白川, かおる

    2003-01-01

    Purpose: To clarify epidermal effects of bed bathing using bar soap and water-dissolved liquid soap (liquid soap). Method: The subjects were 33 healthy female college students. Subjects' arms were cleaned by two methods, using bar soap and liquid soap. The following objective data were collected from the subjects: skin sebum, moisturization, pH, and feelings of skin conditions (rashes, redness, itchiness, and irritation). Results : 1. Cleansing effects of both methods on oily dirt seemed no d...

  12. Ash behavior and de-fluidization in low temperature circulating fluidized bed biomass gasifier

    DEFF Research Database (Denmark)

    Narayan, Vikas

    ensures that high-alkali biomass fuels can be used without risks of bed de-fluidization. This thesis aims to understand the behavior of alkali metals and ash in the LTCFB system. The thesis work involved measurements made on bed material and product gas dust samples on a 100kW LTCFB gasifier placed......Biomass is increasingly used as a fuel for power generation. Herbaceous fuels however, contain high amounts of alkali metals which get volatilized at high temperatures and forms salts with low melting points and thus condense on pipelines, reactor surfaces and may cause de-fluidization. A Low......-Temperature Circulating Fluidized Bed System (LTCFB) gasifier allows pyrolysis and gasification of biomass to occur at low temperatures thereby improving the retention of alkali and other ash species within the system and minimizing the amount of ash species in the product gas. In addition, the low reactor temperature...

  13. 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)

  14. Työntekijöiden ja lähiesimiehen välinen yhteistyö Kissanmaan perhetukikeskuksessa

    OpenAIRE

    Salonen, Jenni

    2009-01-01

    Opinnäytetyöni tavoitteena oli selvittää lähiesimiehen ja työntekijöiden välistä yhteistyötä tamperelaisen Kissanmaan perhetukikeskuksen lastenpäivystys- ja lastenpsykiatrisella kuntoutusosastolla. Tutkimuksessa selvitin yhteistyöaiheita ja mitkä asiat siinä sujuvat ja mitkä vaativat kehittämistä. Lisäksi selvitin, millaista tukea työntekijät lähiesimieheltään saavat. Tarkoitukseni oli myös selvittää, miten työntekijöiden kuuleminen ja työntekijän ja lähiesimiehen välinen yhteistyö liittyvät ...

  15. 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.

  16. Emission performance and combustion efficiency of a conical fluidized-bed combustor firing various biomass fuels

    International Nuclear Information System (INIS)

    Permchart, W.; Kouprianov, V.I.

    2004-01-01

    This paper summarizes the results of an experimental study on combustion of three distinct biomass fuels (sawdust, rice husk and pre-dried sugar cane bagasse) in a single fluidized-bed combustor (FBC) with a conical bed using silica sand as the inert bed material. Temperature, CO, NO and O 2 concentrations along the combustor height as well as in flue (stack) gas were measured in the experimental tests. The effects of fuel properties and operating conditions (load and excess air) on these variables were investigated. Both CO and NO axial profiles were found to have a maximum whose location divides conventionally the combustor volume into formation (lower) and reduction (upper) regions for these pollutants. Based on CO emission and unburned carbon content in fly ash, the combustion efficiency of the conical FBC was quantified for the selected biomass fuels fired under different operating conditions. (Author)

  17. Middle Stone Age bedding construction and settlement patterns at Sibudu, South Africa.

    Science.gov (United States)

    Wadley, Lyn; Sievers, Christine; Bamford, Marion; Goldberg, Paul; Berna, Francesco; Miller, Christopher

    2011-12-09

    The Middle Stone Age (MSA) is associated with early behavioral innovations, expansions of modern humans within and out of Africa, and occasional population bottlenecks. Several innovations in the MSA are seen in an archaeological sequence in the rock shelter Sibudu (South Africa). At ~77,000 years ago, people constructed plant bedding from sedges and other monocotyledons topped with aromatic leaves containing insecticidal and larvicidal chemicals. Beginning at ~73,000 years ago, bedding was burned, presumably for site maintenance. By ~58,000 years ago, bedding construction, burning, and other forms of site use and maintenance intensified, suggesting that settlement strategies changed. Behavioral differences between ~77,000 and 58,000 years ago may coincide with population fluctuations in Africa.

  18. Empirical correlations for axial dispersion coefficient and Peclet number in fixed-bed columns.

    Science.gov (United States)

    Rastegar, Seyed Omid; Gu, Tingyue

    2017-03-24

    In this work, a new correlation for the axial dispersion coefficient was obtained using experimental data in the literature for axial dispersion in fixed-bed columns packed with particles. The Chung and Wen correlation, the De Ligny correlation are two popular empirical correlations. However, the former lacks the molecular diffusion term and the latter does not consider bed voidage. The new axial dispersion coefficient correlation in this work was based on additional experimental data in the literature by considering both molecular diffusion and bed voidage. It is more comprehensive and accurate. The Peclet number correlation from the new axial dispersion coefficient correlation on the average leads to 12% lower Peclet number values compared to the values from the Chung and Wen correlation, and in many cases much smaller than those from the De Ligny correlation. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Design and control of the precise tracking bed based on complex electromechanical design theory

    Science.gov (United States)

    Ren, Changzhi; Liu, Zhao; Wu, Liao; Chen, Ken

    2010-05-01

    The precise tracking technology is wide used in astronomical instruments, satellite tracking and aeronautic test bed. However, the precise ultra low speed tracking drive system is one high integrated electromechanical system, which one complexly electromechanical design method is adopted to improve the efficiency, reliability and quality of the system during the design and manufacture circle. The precise Tracking Bed is one ultra-exact, ultra-low speed, high precision and huge inertial instrument, which some kind of mechanism and environment of the ultra low speed is different from general technology. This paper explores the design process based on complex electromechanical optimizing design theory, one non-PID with a CMAC forward feedback control method is used in the servo system of the precise tracking bed and some simulation results are discussed.

  20. Hydriding and dehydriding characteristics of small-scale DU and ZrCo beds

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Dongyou; Lee, Jungmin; Koo, Daeseo [Korea Atomic Energy Research Institute, 989-111 Daedeokdaero, Yuseong, Daejeon 305-353 (Korea, Republic of); Chung, Hongsuk, E-mail: hschung1@kaeri.kr [Korea Atomic Energy Research Institute, 989-111 Daedeokdaero, Yuseong, Daejeon 305-353 (Korea, Republic of); Kim, Ki Hwan [Korea Atomic Energy Research Institute, 989-111 Daedeokdaero, Yuseong, Daejeon 305-353 (Korea, Republic of); Kang, Hyun-Goo; Chang, Min Ho [National Fusion Research Institute, 113 Gwahakro, Yuseong, Daejeon 305-333 (Korea, Republic of); Camp, Patrick [ITER Organization, Route de Vinon sur Verdon, 13115 Saint Paul Lez Durance (France); Jung, Ki Jung; Cho, Seungyon; Yun, Sei-Hun; Kim, Chang Shuk [National Fusion Research Institute, 113 Gwahakro, Yuseong, Daejeon 305-333 (Korea, Republic of); Yoshida, Hiroshi [Fusion Science Consultant, 3288-10 Sakado-cho, Mito-shi 310-0841, Ibakaki-ken (Japan); Paek, Seungwoo; Lee, Hansoo [Korea Atomic Energy Research Institute, 989-111 Daedeokdaero, Yuseong, Daejeon 305-353 (Korea, Republic of)

    2013-10-15

    Highlights: • We have designed and fabricated a twosome small-scale getter bed for a comparison of ZrCo with DU on the hydriding/dehydriding properties. • We provide preliminary experimental results of our ZrCo and DU beds. -- Abstract: With the development of fusion technology, it will be necessary to store large amounts of tritium during the nuclear fusion fuel cycle. Stable metal tritides are viewed as potential candidates for the high-density storage of tritium. Metal tritide formers offer a safe and convenient method for tritium storage. For the storage, supply, and recovery of hydrogen isotopes, zirconium cobalt (ZrCo) and depleted uranium (DU) have been extensively proposed. Thus, we have designed and fabricated two identical small-scale getter beds for a comparison of ZrCo with DU on the hydriding/dehydriding properties. After the powderization of the metals, the hydriding/dehydriding performance at different stoichiometries of ZrCo and DU was measured. We provide preliminary experimental results of our ZrCo and DU beds.

  1. Performance and metallography of a uranium tritide bed operated at elevated temperatures and tritium pressures

    International Nuclear Information System (INIS)

    Mote, M.W. Jr.; Mintz, J.M.

    1986-12-01

    A uranium gettering bed was cycled between room temperature/zero pressure and 600C/275 psi (D 2 ) for 210 cycles over a period of 8 months. Metallographic examination of the hardware revealed an acceptable amount of reaction between the uranium and the stainless steel container. This exposure is estimated to represent about ten years of normal use

  2. 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

  3. Ammonia, total reduced sulfides, and greenhouse gases of pine chip and corn stover bedding packs

    Science.gov (United States)

    Bedding materials may affect air quality in livestock facilities. The objective of this study was to compare headspace concentrations of ammonia (NH3), total reduced sulfides (TRS), carbon dioxide (CO2),methane (CH4), and nitrous oxide (N2O) when pine wood chips and corn stover were mixed in various...

  4. Sediment and Hydraulic Measurements with Computed Bed Load on the Missouri River, Sioux City to Hermann, 2014

    Science.gov (United States)

    2017-05-01

    ER D C /C HL T R- 17 -8 Sediment and Hydraulic Measurements with Computed Bed Load on the Missouri River , Sioux City to Hermann, 2014...Hydraulic Measurements with Computed Bed Load on the Missouri River , Sioux City to Hermann, 2014 David Abraham, Marielys Ramos-Villanueva, Thad Pratt...Engineers, Omaha and Kansas City Districts, in quantifying sediment bed load and suspended load at several sites on the Missouri River for the

  5. 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.

  6. Distribution of physicians and hospital beds based on Gini coefficient and Lorenz curve: A national survey

    Directory of Open Access Journals (Sweden)

    Satar Rezaei

    2016-06-01

    Full Text Available Introduction: Inequality is prevalent in all sectors, particularly in distribution of and access to resources in the health sector. The aim of current study was to investigate the distribution of physicians and hospital beds in Iran in 2001, 2006 and 2011. Methods: This retrospective, cross-sectional study evaluated the distribution of physicians and hospital beds in 2001, 2006 and 2011 using Gini coefficient and Lorenz curve. The required data, including the number of physicians (general practitioners and specialists, number of hospital beds and number of hospitalized patients were obtained from the statistical yearbook of Iranian Statistical Center (ISC. The data analysis was performed by DASP software. Results: The Gini Coefficients for physicians and hospital beds based on population in 2001 were 0.19 and 0.16, and based on hospitalized patients, were 0.48 and 0.37, respectively. In 2006, these values were found to be 0.18 and 0.15 based on population, and 0.21 and 0.21 based on hospitalized patients, respectively. In 2011, however, the Gini coefficients were reported to be 0.16 and 0.13 based on population, and 0.47 and 0.37 based on hospitalized patients, respectively. Although distribution status had improved in 2011compared with 2001 in terms of population and number of hospitalized patients, there was more inequality in distribution based on the number of hospitalized patients than based on population. Conclusion: This study indicated that inequality in distribution of physicians and hospital beds was declined in 2011 compared with 2001. This distribution was based on the population, so it is suggested that, in allocation of resource, the health policymakers consider such need indices as the pattern of diseases and illness-prone areas, number of inpatients, and mortality.

  7. 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....

  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

    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.

  10. 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.

  11. Design and evaluation of fluidized bed heat recovery for diesel engine systems

    Science.gov (United States)

    Hamm, J. R.; Newby, R. A.; Vidt, E. J.; Lippert, T. E.

    1985-01-01

    The potential of utilizing fluidized bed heat exchangers in place of conventional counter-flow heat exchangers for heat recovery from adiabatic diesel engine exhaust gas streams was studied. Fluidized bed heat recovery systems were evaluated in three different heavy duty transport applications: (1) heavy duty diesel truck; (2) diesel locomotives; and (3) diesel marine pushboat. The three applications are characterized by differences in overall power output and annual utilization. For each application, the exhaust gas source is a turbocharged-adiabatic diesel core. Representative subposed exhaust gas heat utilization power cycles were selected for conceptual design efforts including design layouts and performance estimates for the fluidized bed heat recovery heat exchangers. The selected power cycles were: organic rankine with RC-1 working fluid, turbocompound power turbine with steam injection, and stirling engine. Fuel economy improvement predictions are used in conjunction with capital cost estimates and fuel price data to determine payback times for the various cases.

  12. 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

  13. 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\\.

  14. Volatile Removal Assembly Flight Experiment and KC-135 Packed Bed Experiment: Results and Lessons Learned

    Science.gov (United States)

    Holder, Donald W.; Parker, David

    2000-01-01

    The Volatile Removal Assembly (VRA) is a high temperature catalytic oxidation process that will be used as the final treatment for recycled water aboard the International Space Station (ISS). The multiphase nature of the process had raised concerns as to the performance of the VRA in a microgravity environment. To address these concerns, two experiments were designed. The VRA Flight Experiment (VRAFE) was designed to test a full size VRA under controlled conditions in microgravity aboard the SPACEHAB module and in a 1 -g environment and compare the performance results. The second experiment relied on visualization of two-phase flow through small column packed beds and was designed to fly aboard NASA's microgravity test bed plane (KC-135). The objective of the KC-135 experiment was to understand the two-phase fluid flow distribution in a packed bed in microgravity. On Space Transportation System (STS) flight 96 (May 1999), the VRA FE was successfully operated and in June 1999 the KC-135 packed bed testing was completed. This paper provides an overview of the experiments and a summary of the results and findings.

  15. 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

  16. Bed Bug Information Clearinghouse

    Science.gov (United States)

    Its purpose is to help states, communities, and consumers in efforts to prevent and control bed bug infestations. Currently includes only reviewed material from federal/state/local government agencies, extension services, and universities.

  17. Geochemistry of bed and suspended sediment in the Mississippi river system: provenance versus weathering and winnowing.

    Science.gov (United States)

    Piper, D Z; Ludington, Steve; Duval, J S; Taylor, H E

    2006-06-01

    Stream-bed sediment for the size fraction less than 150 microm, examined in 14,000 samples collected mostly from minor tributaries to the major rivers throughout the Mississippi River drainage system, is composed of 5 mineral fractions identified by factor analysis-Al-silicate minerals, quartz, calcite and dolomite, heavy minerals, and an Fe-Mn fraction. The Al-silicate fraction parallels its distribution in the regolith, emphasizing the local sediment source as a primary control to its distribution. Quartz and the heavy-mineral fraction, and associated trace elements, exhibit a complementary distribution to that of the Al-silicate fraction, with a level of enrichment in the bed sediment that is achieved through winnowing and sorting. The carbonate fraction has a distribution suggesting its dissolution during transport. Trace elements partitioned onto the Fe-Mn, possibly amorphous oxyhydride, fraction are introduced to the streams, in part, through human activity. Except for the heavy-mineral fraction, these fractions are identified in suspended sediment from the Mississippi River itself. Although comparison of the tributary bed sediment with the riverine suspended sediment is problematic, the geochemistry of the suspended sediment seems to corroborate the interpretation of the geochemistry of the bed sediment.

  18. The effect of stable bedding materials on dust levels, microbial air contamination and equine respiratory health.

    Science.gov (United States)

    Kwiatkowska-Stenzel, Agnieszka; Witkowska, Dorota; Sowińska, Janina; Stopyra, Artur

    2017-12-01

    The choice of bedding material affects the quality of air in a stable and, consequently, the respiratory health of horses and humans. The risk of respiratory problems can be mitigated by improving the quality of air in the stable. The choice of bedding material is particularly important in cold climate conditions where horses are kept indoors throughout the year. This study examined the impact of three bedding materials: straw (S), peat with shavings (PS), and crushed wood pellets (CWP). The investigated factors were air contamination, including dust contamination and microbial (bacterial and fungal) contamination, and the condition of the equine respiratory tract. The condition of the respiratory tract was evaluated based on the results of arterial blood biochemistry tests and endoscopic evaluations of the upper respiratory tract. Mechanical dust contamination was lowest for PS (1.09mg/m 3 ) and highest for CWP (4.07mg/m 3 ). Bacterial contamination (in CFU - colony forming units) was highest for PS (5.14log 10 CFU/m 3 ) and lowest for CWP (4.81log 10 CFU/m 3 ). Fungal air contamination was lowest for CWP (4.54log 10 CFU/m 3 ) and highest for S (4.82log 10 CFU/m 3 ) and PS (4.88log 10 CFU/m 3 ). An analysis of physiological indicators revealed that all horses were clinically healthy regardless of the type of applied bedding. The type of bedding material did not exert a clear influence on arterial blood biochemistry or the results of endoscopic evaluations of the respiratory tract; however, the use of alternative for straw bedding materials improved endoscopy results. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. 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

  20. Experimental and theoretical studies on hydrogenation of olefins in multiphase fixed bed reactors

    Energy Technology Data Exchange (ETDEWEB)

    Battsengel, B.; Datsevitch, L.; Jess, A. [Bayreuth Univ. (Germany). Dept. of Chemical Engineering

    2003-07-01

    Multi phase reactors like trickle bed systems are frequently used for gas-liquid reactions. In general, they have complex mass and heat transfer characteristics; scale-up is therefore difficult. The present work focuses on the role of mass transfer on the effective reaction rate, taking catalytic octene hydrogenation as a model reaction. The reaction rate in a trickle bed reactor is by a factor of about 20 smaller than (theoretically) in the absence of any mass transfer limitations. Based on the experimental results, the so-called pre-saturation concept is presented, where only the liquid saturated with hydrogen is fed into the reactor. The effective reaction rate in this two phase system (liquid and solid cat.) is equal or even higher than in a trickle bed reactor. Scale-up problems do not occur, and the pre-saturation concept has also other advantages (lower energy consumption), as discussed in detail in this paper. (orig.)

  1. 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.

  2. Regional Variation in Neonatal Intensive Care Admissions and the Relationship to Bed Supply.

    Science.gov (United States)

    Harrison, Wade N; Wasserman, Jared R; Goodman, David C

    2018-01-01

    To characterize geographic variation in neonatal intensive care unit (NICU) admission rates across the entire birth cohort and evaluate the relationship between regional bed supply and NICU admission rates. This was a population-based, cross-sectional study. 2013 US birth certificate and 2012 American Hospital Association data were used to assign newborns and NICU beds to neonatal intensive care regions. Descriptive statistics of admission rates were calculated across neonatal intensive care regions. Multilevel logistic regression was used to examine the relationship between bed supply and individual odds of admission, with adjustment for maternal and newborn characteristics. Among 3 304 364 study newborns, the NICU admission rate was 7.2 per 100 births and varied across regions for all birth weight categories. IQRs in admission rates were 84.5-93.2 per 100 births for 500-1499 g, 35.3-46.1 for 1500-2499 g, and 3.5-5.5 for ≥2500 g. Adjusted odds of admission for newborns of very low birth weight were unrelated to regional bed supply; however, newborns ≥2500 g in regions with the highest NICU bed supply were significantly more likely to be admitted to a NICU than those in regions with the lowest (aOR 1.20 [1.03-1.40]). There is persistent underuse of NICU care for newborns of very low birth weight that is not associated with regional bed supply. Among larger newborns, we find evidence of supply-sensitive care, raising concerns about the potential overuse of expensive and unnecessary care. Rather than improving access to needed care, NICU expansion may instead further deregionalize neonatal care, exacerbating underuse. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. Test-element assembly and loading parameters for the in-pile test of HCPB ceramic pebble beds

    Energy Technology Data Exchange (ETDEWEB)

    Laan, J.G. van der E-mail: vanderlaan@nrg-nl.com; Boccaccini, L.V.; Conrad, R.; Fokkens, J.H.; Jong, M.; Magielsen, A.J.; Pijlgroms, B.J.; Reimann, J.; Stijkel, M.P.; Malang, S

    2002-11-01

    In the framework of developing the helium cooled pebble-bed (HCPB) blanket an irradiation test of pebble-bed assemblies is prepared at the HFR Petten. The test objective is to concentrate on the effect of neutron irradiation on the thermal-mechanical behaviour of the HCPB breeder pebble-bed at DEMO representative levels of temperature and defined thermal-mechanical loads. The paper reports on the project status, and presents the results of pre-tests, material characteristics, the manufacturing of the pebble-bed assemblies, and the nuclear and thermo-mechanical loading parameters.

  4. 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.

  5. Conversion of metallurgical coke and coal using a Coal Direct Chemical Looping (CDCL) moving bed reactor

    International Nuclear Information System (INIS)

    Luo, Siwei; Bayham, Samuel; Zeng, Liang; McGiveron, Omar; Chung, Elena; Majumder, Ankita; Fan, Liang-Shih

    2014-01-01

    Highlights: • Accumulated more than 300 operation hours were accomplished for the moving bed reducer reactor. • Different reactor operation variables were investigated with optimal conditions identified. • High conversions of sub-bituminous coal and bituminous coal were achieved without flow problems. • Co-current and counter-current contact modes were tested and their applicability was discussed. - Abstract: The CLC process has the potential to be a transformative commercial technology for a carbon-constrained economy. The Ohio State University Coal Direct Chemical Looping (CDCL) process directly converts coal, eliminating the need for a coal gasifier oran air separation unit (ASU). Compared to other solid-fuel CLC processes, the CDCL process is unique in that it consists of a countercurrent moving bed reducer reactor. In the proposed process, coal is injected into the middle of the moving bed, whereby the coal quickly heats up and devolatilizes, splitting the reactor roughly into two sections with no axial mixing. The top section consists of gaseous fuel produced from the coal volatiles, and the bottom section consists of the coal char mixed with the oxygen carrier. A bench-scale moving bed reactor was used to study the coal conversion with CO 2 as the enhancing gas. Initial tests using metallurgical cokefines as feedstock were conducted to test the effects of operational variables in the bottom section of the moving bed reducer, e.g., reactor temperature, oxygen carrier to char ratio, enhancer gas CO 2 flow rate, and oxygen carrier flow rates. Experiments directly using coal as the feedstock were subsequently carried out based on these test results. Powder River Basin (PRB) coal and Illinois #6 coal were tested as representative sub-bituminous and bituminous coals, respectively. Nearly complete coal conversion was achieved using composite iron oxide particles as the oxygen carriers without any flow problems. The operational results demonstrated that a

  6. Bed slope effects on turbulent wave boundary layers: 2. Comparison with skewness, asymmetry, and other effects

    DEFF Research Database (Denmark)

    Fuhrman, David R.; Fredsøe, Jørgen; Sumer, B. Mutlu

    2009-01-01

    currents or undertow). The effects from each of the four components are isolated and quantified using a standard set of bed shear stress quantities, allowing their easy comparison. For conditions representing large shallow-water waves on steep slopes, the results suggest that converging-diverging effects......A numerical model solving incompressible Reynolds-averaged Navier-Stokes equations, combined with a two-equation k-omega model for turbulence closure, is used to systematically compare the relative strength of bed shear stress quantities and boundary layer streaming under wave motions from four...... from beach slope may make a significant onshore bed load contribution. Generally, however, the results suggest wave skewness (in addition to conventional steady streaming) as the most important onshore contribution outside the surf zone. Streaming induced within the wave boundary layer is also...

  7. 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.

  8. 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

  9. Experimental analysis and evaluation of the mass transfer process in a trickle-bed reactor

    OpenAIRE

    Silva, J.D.; Lima, F.R.A.; Abreu, C.A.M.; Knoechelmann, A.

    2003-01-01

    A transient experimental analysis of a three-phase descendent-cocurrent trickle-bed H2O/CH4-Ar/g -Al2O3 system was made using the stimulus-response technique, with the gas phase as a reference. Methane was used as a tracer and injected into the argon feed and the concentration vs time profiles were obtained at the entrance and exit of the bed, which were maintained at 298K and 1.013 10(5) Pa. A mathematical model for the tracer was developed to estimate the axial dispersion overall gas-liquid...

  10. 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

  11. 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

  12. 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...

  13. 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.

  14. Bed Rest and Hypoxic Exposure Affect Sleep Architecture and Breathing Stability

    Science.gov (United States)

    Morrison, Shawnda A.; Mirnik, Dani; Korsic, Spela; Eiken, Ola; Mekjavic, Igor B.; Dolenc-Groselj, Leja

    2017-01-01

    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. PMID:28676764

  15. Bed Bugs FAQs

    Science.gov (United States)

    ... Europe. Bed bugs have been found in five-star hotels and resorts and their presence is not ... Health – Division of Parasitic Diseases Email Recommend Tweet YouTube Instagram Listen Watch RSS ABOUT About CDC Jobs ...

  16. Short communication: Environmental mastitis pathogen counts in freestalls bedded with composted and fresh recycled manure solids.

    Science.gov (United States)

    Cole, K J; Hogan, J S

    2016-02-01

    An experiment was conducted to compare bacterial counts of environmental mastitis pathogens in composted recycled manure solids bedding with those in fresh recycled manure solids. Eighteen Holstein cows were housed in 1 pen with 18 stalls. One row of 9 freestalls included mattresses and was bedded weekly with composted recycled manure solids. The second row of 9 freestalls included mattresses and was bedded weekly with fresh recycled manure solids. The back one-third of stalls toward the alleyway was covered in 25 to 50 mm of bedding. Samples were taken from the back one-third of 4 stalls for both treatments on d 0, 1, 2, and 6 of each week. After 3 wk, bedding treatments were switched between rows, making the total duration 6 wk. Mean total gram-negative bacterial counts were approximately 0.5 log10 cfu/g of dry matter lower in the composted recycled manure solids on d 0 compared with fresh recycled manure solids. Klebsiella species, coliform, and Streptococcus species counts were at least 1.0 log10 cfu/g of dry matter lower in composted compared with fresh recycled manure solids on d 0. Only gram-negative bacterial counts on d 1 were reduced in composted recycled manure solids compared with fresh recycled manure solids. Differences were not observed between treatments in gram-negative bacterial, coliform, Klebsiella species, or Streptococcus species counts on d 2 and 6. Ash content was higher in composted recycled manure solids compared with fresh recycled manure solids on d 0, 1, 2, and 6. Despite the increase in ash after composting, bacterial counts of mastitis pathogens in composted recycled manure solids were comparable with those in fresh recycled manure when used as freestall bedding. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  17. 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.

  18. Fluid bed porosity equation for an inverse fluidized bed bioreactor with particles growing biofilm

    International Nuclear Information System (INIS)

    Campos-Diaz, K. E.; Limas-Ballesteros, R.

    2009-01-01

    Fluid Bed Bioreactor performance is strongly affected by bed void fraction or bed porosity fluctuations. Particle size enlargement due to biofilm growth is an important factor that is involved in these variations and until now there are no mathematical equations that consider biofilm growth. In this work a mathematical equation is proposed to calculate bed void fraction in an inverse fluid bed bioreactor. (Author)

  19. 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

  20. The red bed-type and sandstone-type uranium deposits in the inland basins of the northwest China

    International Nuclear Information System (INIS)

    Wang Zhilong.

    1988-01-01

    On the basis of the study on the relationship between the red bed-type and sandstone-type uranium deposits in the inland basins of the northwest China, a classification of red beds based on sedimentary facies and redding origin is presented. Red beds in the inland badins can be divided into six types: 1. alluvial plain and 2. shallow lake red beds formed at the stage of continental disintegration; 3. fluvial alluvial red bed, 4. delta plain and 5. desert red beds formed at the diagenetic-epigenetic stage; 6. spattered red (secondaty red beds) formed at the hypergenic weathering stage. According to the characteristics, structural environments of these six types of red beds, and changes of various geochemical characteristic values (Eh, pH, Th/U, Fe 3+ /Fe 2+ , Sr/Ba, etc.) from host rocks to different kinds of red beds , the relationship between these values and sandstone-type uranium deposits was determined. it is an open system, the mobile uranium is easily leached, thus it is unfavoutable for mineralization; but when the rock reddens at the diagenetic epigenetic stage (closed system) that is favourable for mineraizaltion, the mobile uranium can be concentrated to form uranium deposits

  1. Research and application of packing density for pebble bed in HTR

    International Nuclear Information System (INIS)

    Yu Fujiang; Xie Fei; Sun Ximing

    2015-01-01

    The pebble bed high temperature gas-cooled reactor is one of the major types of reactors developed by Chinese nuclear technology. The statistical analysis for packing density in the pebble bed is an important issue of physical-thermal calculation and safety analysis. Aimed to this problem, a new kind of method was set up to solve this problem. Compared with the traditional lattice-fill method and the experiment, its efficiency and accuracy were verified, while helping to find out the best length of unit in the traditional lattice-fill method. This method was used to analyze the boundary effects observed by experiments. (authors)

  2. Complex burrows of the mud shrimp Callianassa truncata and their geochemical impact in the sea bed

    DEFF Research Database (Denmark)

    Ziebis, W.; Forster, S.; Huettel, M.

    1996-01-01

    the overlying water and rapid consumption within the sea bed, Macrofauna organisms living within the sea bed affect the physical structure of the sea floor, its chemical zonations and the exchange processes across the sediment-water interface(3,4). Thalassinidean mud-shrimps are often abundant in tropical......). Here we report the use of a diver observatory within the seabed, along with in situ measurements, to assess the geochemical impact of the mud-shrimp Callianassa truncata Giard and Bonnier (Decapoda, Thalassinidea), a species that commonly inhabits sandy sediments in the Mediterranean sea....

  3. Gaseous emissions in pressurised fluidised-bed combustion. Analysis and summary of the pilot experiments

    International Nuclear Information System (INIS)

    Korpela, T.; Hippinen, I.; Konkola, M.

    1996-01-01

    The influence of operating conditions on gaseous emissions in pressurised fluidised-bed combustion have been studied. The research objectives have been behaviour of sulphur absorbents and reduction of sulphur dioxide emissions, reduction of nitrogen oxide emissions, release of vapour-phase alkalimetals and carbon monoxide emissions. The sulphur capture capacities of calcium-based sorbents under PFBC conditions have been studied at a pressurised fluidised-bed reactor and at a pressurised thermogravimetric apparatus. The project has also connected results of the experimental PFBC at HUT/EVO. (author)

  4. Modeling Non-Fickian Transport and Hyperexponential Deposition for Deep Bed Filtration

    DEFF Research Database (Denmark)

    Yuan, Hao; Shapiro, Alexander

    2010-01-01

    An integral model of the deep bed filtration process has been developed. It incorporates pore and particle size distributions, as well as the particle residence time distribution in the framework of the continuous time random walk theory. Numerical modeling is carried out to study the factors...... influencing breakthrough curves and deposition profiles for the deep bed filtration systems. Results are compared with a large set of experimental observations. Our findings show that highly dispersed breakthrough curves, e.g. those with early arrivals and large ending tails, correspond to large dispersion...

  5. 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.)

  6. 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

  7. 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

  8. 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

  9. 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.

  10. 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.

  11. Control, data acquisition and analysis for the JET neutral injection test bed

    International Nuclear Information System (INIS)

    Jones, T.T.C.; Brenan, P.R.; Rodgers, M.E.; Stork, D.; Young, I.D.

    1985-01-01

    The Neutral Injection Test-Bed (NITB) is a major experimental assembly in support of the Neutral Beam Heating Programme for JET. In addition to its prime function of testing the Neutral Injection hardware, the Test Bed serves as the prototype to test the computer control and data acquisition system, which is described in this paper. The software system has been written in a portable, data-driven manner with the aim to adapt it, with only minor modifications to the operation of the first. Neutral Injection Beamline on JET, which will involve operation both synchronous and asynchronous with that of the JET Tokamak

  12. 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

  13. 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

  14. 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.

  15. 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...NUMBER 62601F 6. AUTHOR(S) Norman Fitz-Coy 5d. PROJECT NUMBER 4846 5e. TASK NUMBER PPM00015968 5f. WORK UNIT NUMBER EF125135 7. PERFORMING

  16. 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

  17. 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

  18. Channel change and bed-material transport in the Lower Chetco River, Oregon

    Science.gov (United States)

    Wallick, J. Rose; Anderson, Scott W.; Cannon, Charles; O'Connor, Jim E.

    2010-01-01

    The lower Chetco River is a wandering gravel-bed river flanked by abundant and large gravel bars formed of coarse bed-material sediment. Since the early twentieth century, the large gravel bars have been a source of commercial aggregate for which ongoing permitting and aquatic habitat concerns have motivated this assessment of historical channel change and sediment transport rates. Analysis of historical channel change and bed-material transport rates for the lower 18 kilometers shows that the upper reaches of the study area are primarily transport zones, with bar positions fixed by valley geometry and active bars mainly providing transient storage of bed material. Downstream reaches, especially near the confluence of the North Fork Chetco River, are zones of active sedimentation and channel migration.Multiple analyses, supported by direct measurements of bedload during winter 2008–09, indicate that since 1970 the mean annual flux of bed material into the study reach has been about 40,000–100,000 cubic meters per year. Downstream tributary input of bed-material sediment, probably averaging 5–30 percent of the influx coming into the study reach from upstream, is approximately balanced by bed-material attrition by abrasion. Probably little bed material leaves the lower river under natural conditions, with most net influx historically accumulating in wider and more dynamic reaches, especially near the North Fork Chetco River confluence, 8 kilometers upstream from the Pacific Ocean.The year-to-year flux, however, varies tremendously. Some years may have less than 3,000 cubic meters of bed material entering the study area; by contrast, some high-flow years, such as 1982 and 1997, likely have more than 150,000 cubic meters entering the reach. For comparison, the estimated annual volume of gravel extracted from the lower Chetco River for commercial aggregate during 2000–2008 has ranged from 32,000 to 90,000 cubic meters and averaged about 59,000 cubic meters per

  19. BedMachine v3: Complete Bed Topography and Ocean Bathymetry Mapping of Greenland From Multibeam Echo Sounding Combined With Mass Conservation

    DEFF Research Database (Denmark)

    Morlighem, M.; Williams, C. N.; Rignot, E.

    2017-01-01

    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...... 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....

  20. 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.

  1. The relationship between bedding and face-down death in infancy: mathematical analysis of a respiratory simulation system using an infant mannequin to assess gas diffusibility in bedding.

    Science.gov (United States)

    Sakai, Jun; Funayama, Masato; Kanetake, Jun

    2007-02-14

    Rebreathing is a model for the relationship between a prone sleeping position and sudden infant death syndrome. This study used a mechanical simulation model to establish the relationship between types of bedding and rebreathing potential for an infant placed prone (face down) at different postnatal ages. The infant mannequin was connected to a respirator set to deliver physiologically appropriate combinations of tidal volume (V(T)) and respiratory rates (RR) across a range of postnatal ages (0-18 months). Before measurements were made, CO(2) flow was regulated to 5+/-0.1% of end-tidal PCO(2) (EtCO(2)). After the model was placed in a prone position, any increase in the fractional concentration of inspired CO(2) (FiCO(2)) was measured. FiCO(2) increased immediately and rapidly, and reached a maximum value within a few minutes. The maximum FiCO(2) ranged from under 2% to over 10%, depending on the bedding. FiCO(2) was also affected by V(T) and RR. This model is not applicable to actual infants because of the large tissue stores of CO(2) in infants; however, it is useful for evaluation of gas diffusibility of bedding and will simplify the investigation of sleeping environments when a baby is found dead with its face covered by soft bedding. In general, the higher the FiCO(2), the greater the rebreathing potential. Theoretically, considering the paucity of body stores of O(2), changes in FiO(2) would be affected not by changes in FiCO(2), but by CO(2) production and gas movement around the infant's face. The rapid decrease of FiO(2) is approximated at the inverse of the FiCO(2) timecourse, suggesting the significance of not only CO(2) accumulation but also O(2) deprivation in the potential space around the baby's face.

  2. 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

  3. 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

  4. 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.

  5. 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.

  6. Separating bathymetric data representing multiscale rhythmic bed forms : a geostatistical and spectral method compared

    NARCIS (Netherlands)

    van Dijk, Thaiënne A.G.P.; Lindenbergh, Roderik C.; Egberts, Paul J.P.

    2008-01-01

    The superimposition of rhythmic bed forms of different spatial scales is a common and natural phenomenon on sandy seabeds. The dynamics of such seabeds may interfere with different offshore activities and are therefore of interest to both scientists and offshore developers. State-of-the-art echo

  7. 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...

  8. 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

  9. The phenomenon of diminishing –returns in the use of bed nets and ...

    African Journals Online (AJOL)

    2014-03-01

    Mar 1, 2014 ... treated bed nets and prompt malaria therapy in Tororo. Uganda, concluded the .... namely vaccination, cure and quarantine and yet cure for malaria actually ..... It is therefore the anti-malarial medicines given to their children that are .... his great assistance in the preparation of the electronic version of this ...

  10. 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...

  11. House dust mites on skin, clothes, and bedding of atopic dermatitis patients.

    Science.gov (United States)

    Teplitsky, Valery; Mumcuoglu, Kosta Y; Babai, Ilan; Dalal, Ilan; Cohen, Rifka; Tanay, Amir

    2008-08-01

    Atopic dermatitis is a common allergic condition in children, often associated with a positive skin reaction to house dust mite allergens. To determine the presence of house dust mites on the skin, clothes, and bedding of patients with atopic dermatitis. Nineteen patients with atopic dermatitis were examined during a 2-year period. Samples from affected and healthy skin surfaces were obtained with adhesive tape, and dust samples from bedding and clothes were collected with a vacuum cleaner at the start of the study and 3-6 weeks later, and examined for the presence of house dust mites. The findings were compared with those of 21 healthy controls. The most common mite species on skin were Dermatophagoides pteronyssinus and Dermatophagoides farinae, which were found in nine patients and three controls. The patient group showed a significantly larger percentage of samples with mites than did the control group (34.9% and 7.9%, respectively) (P bedding of patients, or between patients and controls with regard to the number of mites on the clothes and bedding. Patients with atopic dermatitis showed a higher prevalence of mites on their skin than did healthy individuals, which could be involved in allergic sensitization and disease exacerbation.

  12. 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.

  13. 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.

  14. Investigation of hydrodynamic parameters in a novel expanded bed configuration: local axial dispersion characterization and an empirical correlation study

    Directory of Open Access Journals (Sweden)

    E. S. Taheri

    2012-12-01

    Full Text Available Study of liquid behavior in an expanded bed adsorption (EBA system is important for understanding, modeling and predicting nanobioproduct/biomolecule adsorption performance in such processes. In this work, in order to analyze the local axial dispersion parameters, simple custom NBG (Nano Biotechnology Group expanded bed columns with 10 and 26 mm inner diameter were modified by insertion of sampling holes. Based on this configuration, the particles and liquid can be withdrawn directly from various axial positions of the columns. Streamline DEAE particles were used as solid phase in this work. The effects of factors such as liquid velocity, viscosity, settled bed height and column diameter on the hydrodynamic parameters were investigated. Local bed voidages in different axial bed positions were measured by a direct procedure within the column with 26 mm diameter. Increasing trend of voidage with velocity at a certain position of the bed and with bed height at a certain degree of expansion was observed. Residence time distribution (RTD analysis at various bed points showed approximately uniform hydrodynamic behavior in the column with 10 mm diameter while a decreasing trend of mixing/dispersion along the bed height at a certain degree of expansion was seen in the column with 26 mm diameter. Also lower mixing/dispersion occured in the smaller diameter column. Finally, a combination of two empirical correlations proposed by Richardson-Zaki and Tong-Sun was successfully employed for identification of the bed voidage at various bed heights (RSSE=99.9%. Among the empirical correlations presented in the literatures for variation of the axial dispersion coefficient, the Yun correlation gave good agreement with our experimental data (RSSE=87% in this column.

  15. 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.

  16. 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

  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. 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

  19. Identification and MPC control of a circulation fluidized bed boiler using an LPV model

    NARCIS (Netherlands)

    Huang, J.; Ji, G.; Zhu, Y.; Lin, W.; Kothare, M.; Tade, M.; Vande Wouwer, A.; Smets, I.

    2010-01-01

    This work studies the identification and control of circulation fluidized bed (CFB) boilers. The CFB boiler under investigation shows strong nonlinearity due to big changes of steam load. A linear parameter varying (LPV) model is used to represent the process dynamics and used in control. The steam

  20. Experience gained in bench scale and pilot scale fluidised bed processing

    CSIR Research Space (South Africa)

    Hadley, TD

    2005-01-01

    Full Text Available of titanium dioxide. Expertise in the design and commissioning of industrial-scale plants has led to the supply (through licensees) of a biomass sludge incinerator/boiler generating 26t/h steam, a 20 MW high-sulphur pitch incinerator and a 12 MW fluidised bed...

  1. Modeling river dune development and dune transition to upper stage plane bed

    NARCIS (Netherlands)

    Naqshband, Suleyman; van Duin, Olav; Ribberink, Jan S.; Hulscher, Suzanne J.M.H.

    2016-01-01

    Large asymmetric bedforms known as dunes commonly dominate the bed of sand rivers. Due to the turbulence generation over their stoss and lee sides, dunes are of central importance in predicting hydraulic roughness and water levels. During floods in steep alluvial rivers, dunes are observed to grow

  2. 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.

  3. Distribution of volatile sulphur containing products during fixed bed pyrolysis and gasification of coals

    Energy Technology Data Exchange (ETDEWEB)

    Furimsky, E.

    1991-08-01

    Various coals were used to study the evolution of H{sub 2}S COS, and SO{sub 2} in a fixed bed reactor. For all types of coal, most of H{sub 2}S and SO{sub 2} were released during the devolatilization stage. COS was formed only during the gasification stage in the presence of CO{sub 2}.

  4. Nature and characteristics of pulsing flow in trickle-bed reactors

    NARCIS (Netherlands)

    Boelhouwer, J.G.; Piepers, H.W.; Drinkenburg, A.A.H.

    2002-01-01

    Pulsing flow is well known for its advantages in terms of an increase in mass and heat transfer rates, complete catalyst wetting and a decrease in axial dispersion compared to trickle flow. The operation of a trickle-bed reactor in the pulsing flow regime is favorable in terms of a capacity increase

  5. 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...

  6. 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...

  7. 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.

  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. High School Students’ Use of Sunscreen and Tanning Beds

    Centers for Disease Control (CDC) Podcasts

    This podcast is an interview with Corey Basch, EdD, MPH, assistant professor in the Department of Public Health at William Paterson University. Dr. Basch discusses her study on high school students’ use of sunscreen and tanning beds between 2001 and 2011.

  10. "Ten in a Bed": Literacy, Intermediality and the Potentials of Low-Tech

    Science.gov (United States)

    Beswick, Katie

    2016-01-01

    "Ten in Bed" was a project led by participatory arts organisation Phakama, in partnership with Queen Mary University of London. Over an eight-week period we ran a series of intermedial arts workshops and staged a performance with under five-year-olds and their families at a community centre in Bethnal Green, London. We attempted to…

  11. 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