WorldWideScience

Sample records for bedding and linens

  1. China Linen Signs Agreement to Ship Fabric to Italy

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    China Linen Textile Industry, Ltd. a China-based company engaged in the production and sale of linen yarn and various types of linen fabric, announced that its wholly-owned subsidiary, Heilongjiang Lanxi Sunrise

  2. 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...

  3. Cleanliness of Linen and Clothing Items Professionally Laundered or Dry-Cleaned.

    Science.gov (United States)

    Oie, Shigeharu; Furukawa, Hiroyuki; Kobayashi, Hiroyoshi; Okubo, Takashi

    2016-01-21

    We asked 14 professional cleaners (laundry services) to clean various unused (new) linen and clothing items with a microbial contamination level of laundered or dry-cleaned items. After laundering, 6 (21.4%) of the 28 samples from 4 of the 14 cleaners (28.6%) were contaminated (1-1,200 cfu/cm(2)). After dry-cleaning, 2 (7.1%) of the 28 samples from 2 (14.3%) of the 14 cleaners were contaminated (7-10 cfu/cm(2)). The main contaminant was Bacillus cereus. No sample of the laundered or dry-cleaned items showed Staphylococcus aureus, Escherichia coli, or Pseudomonas aeruginosa contamination. All 14 cleaners investigated in this study used batch-type washing machines. Therefore, batch-type washing machines can cause contamination of linen and clothing items with B. cereus. PMID:26073734

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

    Science.gov (United States)

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

    2011-11-01

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

  5. Purification and Characterization of an Extracellular Proteinase from Brevibacterium linens ATCC 9174

    OpenAIRE

    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(deg)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. Mg(sup2+) and Ca(sup2+) activated the proteinase, as did NaCl; however, Hg(sup2+), Fe(sup2+), and Zn(sup2+) caused strong i...

  6. Identification and Functional Analysis of the Gene Encoding Methionine-γ-Lyase in Brevibacterium linens

    OpenAIRE

    Amarita, Felix; Yvon, Mireille; Nardi, Michele; Chambellon, Emilie; Delettre, Jerôme; Bonnarme, Pascal

    2004-01-01

    The enzymatic degradation of l-methionine and subsequent formation of volatile sulfur compounds (VSCs) is believed to be essential for flavor development in cheese. l-Methionine-γ-lyase (MGL) can convert l-methionine to methanethiol (MTL), α-ketobutyrate, and ammonia. The mgl gene encoding MGL was cloned from the type strain Brevibacterium linens ATCC 9175 known to produce copious amounts of MTL and related VSCs. The disruption of the mgl gene, achieved in strain ATCC 9175, resulted in a 62% ...

  7. Purification and Characterization of l-Methionine γ-Lyase from Brevibacterium linens BL2†

    OpenAIRE

    Dias, Benjamin; Weimer, Bart

    1998-01-01

    l-Methionine γ-lyase (EC 4.4.1.11) was purified to homogeneity from Brevibacterium linens BL2, a coryneform bacterium which has been used successfully as an adjunct bacterium to improve the flavor of Cheddar cheese. The enzyme catalyzes the α,γ elimination of methionine to produce methanethiol, α-ketobutyrate, and ammonia. It is a pyridoxal phosphate-dependent enzyme, with a native molecular mass of approximately 170 kDa, consisting of four identical subunits of 43 kDa each. The purified enzy...

  8. Nucleotide sequence and taxonomical distribution of the bacteriocin gene lin cloned from Brevibacterium linens M18.

    OpenAIRE

    Valdes-Stauber, N; Scherer, S

    1996-01-01

    Linocin M18 is an antilisterial bacteriocin produced by the red smear cheese bacterium Brevibacterium linens M18. Oligonucleotide probes based on the N-terminal amino acid sequence were used to locate its single copy gene, lin, on the chromosomal DNA. The amino acid composition, N-terminal sequence, and molecular mass derived from the nucleotide sequence of an open reading frame of 798 nucleotides coding for 266 amino acids found on a 3-kb BamHI restriction fragment correspond closely to thos...

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

    Science.gov (United States)

    Reddy, Narendra; Yang, Yiqi

    2007-08-01

    We report the production and characteristics of natural cellulose fibers obtained from the leaves and stems of switchgrass. In this paper, the composition, structure and properties of fibers obtained from the leaves and stem of switchgrass have been studied in comparison to the common natural cellulose fibers, such as cotton, linen and kenaf. The leaves and stems of switchgrass have tensile properties intriguingly similar to that of linen and cotton, respectively. Fibers were obtained from the leaves and stems of switchgrass using a simple alkaline extraction and the structure and properties of the fibers were studied. Fibers obtained from switchgrass leaves have crystallinity of 51%, breaking tenacity of 5.5 g per denier (715 MPa) and breaking elongation of 2.2% whereas the corresponding values for fibers obtained from switchgrass stems are 46%, 2.7 g per denier and 6.8%, respectively. Switchgrass is a relatively easy to grow and high yield biomass crop that can be source to partially substitute the natural and synthetic fibers currently in use. We hope that this research will stimulate interests in using switchgrass as a novel fiber crop in addition to being promoted as a potential source for biofuels. PMID:17221888

  10. Heterologous production of methionine-γ-lyase from brevibacterium linens in lactococcus lactis and formation of volatile sulfur compounds

    OpenAIRE

    Hanniffy, Sean; Philo, Mark; Peláez, Carmen; Gasson, M. J.; Requena, Teresa; Martínez-Cuesta, M. Carmen

    2009-01-01

    The conversion of methionine to volatile sulfur compounds (VSCs) is of great importance in flavor formation during cheese ripening and is the focus of biotechnological approaches toward flavor improvement. A synthetic mgl gene encoding methionine-γ-lyase (MGL) from Brevibacterium linens BL2 was cloned into a Lactococcus lactis expression plasmid under the control of the nisin-inducible promoter PnisA. When expressed in L. lactis and purified as a recombinant protein, MGL was shown to degrade ...

  11. Influence of Oxygen and pH on Methanethiol Production from l-Methionine by Brevibacterium linens CNRZ 918

    OpenAIRE

    Ferchichi, Mohamed; Hemme, Denis; Bouillanne, Christian

    1986-01-01

    The effects of dissolved oxygen concentration and pH on the growth of Brevibacterium linens CNRZ 918 and its production of methanethiol from l-methionine were investigated. Optimal specific methanethiol production was obtained at 25% saturation of dissolved oxygen and at a pH between 8 and 9, whereas optimal cell growth occurred at 50% oxygen saturation and when the pH was maintained constantly at 7. Methanethiol production by nonproliferating bacteria required the presence of l-methionine (7...

  12. Draft Genome Sequence of Brevibacterium linens AE038-8, an Extremely Arsenic-Resistant Bacterium.

    Science.gov (United States)

    Maizel, Daniela; Utturkar, Sagar M; Brown, Steven D; Ferrero, Marcela A; Rosen, Barry P

    2015-01-01

    To understand the arsenic biogeocycles in the groundwaters at Tucumán, Argentina, we isolated Brevibacterium linens sp. strain AE38-8, obtained from arsenic-contaminated well water. This strain is extremely resistant to arsenicals and has arsenic resistance (ars) genes in its genome. Here, we report the draft genome sequence of B. linens AE38-8. PMID:25883298

  13. Draft Genome Sequence of Brevibacterium linens AE038-8, an Extremely Arsenic-Resistant Bacterium

    OpenAIRE

    Maizel, Daniela; Utturkar, Sagar M.; Brown, Steven D.; Ferrero, Marcela A.; ROSEN, BARRY P.

    2015-01-01

    To understand the arsenic biogeocycles in the groundwaters at Tucumán, Argentina, we isolated Brevibacterium linens sp. strain AE38-8, obtained from arsenic-contaminated well water. This strain is extremely resistant to arsenicals and has arsenic resistance (ars) genes in its genome. Here, we report the draft genome sequence of B. linens AE38-8.

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

    Directory of Open Access Journals (Sweden)

    Ildar G. Shaikhiev

    2014-03-01

    Full Text Available 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 shows that along with the physical sorption process proceeds chemisorption.

  15. Bed rest and immunity

    Science.gov (United States)

    Sonnenfeld, Gerald; Aviles, Hernan; Butel, Janet S.; Shearer, William T.; Niesel, David; Pandya, Utpal; Allen, Christopher; Ochs, Hans D.; Blancher, Antoine; Abbal, Michel

    2007-02-01

    Space flight has been shown to result in altered immune responses. The current study was designed to investigate this possibility by using the bed rest model of some space flight conditions. A large number of women are included as subjects in the study. The hypothesis being tested is: 60 days head-down tilt bed rest of humans will affect the immune system and resistance to infection. Blood, urine and saliva samples will be obtained from bed rest subjects prior to, at intervals during, and after completion of 60 days of head-down tilt bed rest. Leukocyte blastogenesis, cytokine production and virus reactivation will be assessed. The ability of the subjects to respond appropriately to immunization with the neoantigen bacteriophage φX-174 will also be determined. Bed rest is being carried out at MEDES, Toulouse France, and the University of Texas Medical Branch, Galveston, TX. The studies to be carried out in France will also allow assessment of the effects of muscle/bone exercise and nutritional countermeasures on the immune system in addition to the effects of bed rest.

  16. 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.

  17. Inhibition of Brevibacterium linens by Probiotics from Dairy Products

    OpenAIRE

    Knox, Alison M.; Viljoen, Bennie C.; Lourens-Hattingh, Analie

    2005-01-01

    Brevibacterium linens is an important species in dairy products rendering a specific taste and aroma to numerous smear ripened and blue veined cheeses due to proteolysis. However, the presence of the species in South African blue veined cheeses is undesirable and consumers demand the product void of the species. Accordingly, numerous methods including microbial inhibition using fungi and bacterial probiotic cultures with possible inhibitory effects were applied in an attempt to inhibit the sp...

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

    Science.gov (United States)

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

    2015-01-01

    Twenty-two Brevibacterium linens strains isolated from 'Pecorino di Filiano' cheese ripened in two different environments (natural cave and storeroom) were characterized and differentiated for features of technological interest and by genotypic methods, in order to select strains with specific features to be used as surface starter cultures. Results showed significant differences among strains on the basis of physiological and technological features, indicating heterogeneity within the species. A middle-low level of proteolytic activity was observed in 27.3 % of strains, while a small group (9.1 %) showed a high ability. Lipolytic activity was observed at three different temperatures and the highest value was detected at 20 °C with 13.6 % of strains, while an increase in temperature produced a slightly lower lipolysis in all strains. The evaluation of diacetyl production revealed that only 22.8 % of strains showed this ability, and most of them were isolated from product ripened in the natural cave. All strains exhibited only leu-aminopeptidase activity, with values more elevated in strains coming from the natural cave product. The combined analysis of genotypic results with the data obtained by the features of technological interest study established that the random amplified polymorphic DNA (RAPD) clusters obtained were composed not only of different genotypes but of different profiles based on technological properties too. This study demonstrated the importance of the ripening environment that affects the typical features of the artisanal product, leading to the selection of a specific surface microflora. Characterized strains could be associated within surface starters to standardize the production process of cheese, but preserving its typical organoleptic and sensory characteristics and improving the quality of the final product. PMID:25147054

  19. 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...

  20. Transport of aromatic amino acids by Brevibacterium linens.

    OpenAIRE

    Boyaval, P; Moreira, E; Desmazeaud, M. J.

    1983-01-01

    Whole metabolizing Brevibacterium linens cells were used to study the transport of aromatic amino acids. Kinetic results followed the Michaelis-Menten equation with apparent Km values for phenylalanine, tyrosine, and tryptophan of 24, 3.5, and 1.8 microM. Transport of these amino acids was optimum at pH 7.5 and 25 degrees C for phenylalanine and pH 8.0 and 35 degrees C for tyrosine and tryptophan. Crossed inhibitions were all noncompetitive. The only marked stereospecificity was for the L for...

  1. An MRP system for surgical linen management at a large hospital.

    Science.gov (United States)

    O'Neill, L; Murphy, M; Gray, D; Stoner, T

    2001-02-01

    Materials Requirements Planning (MRP) has been used extensively in manufacturing and other industries to improve on-time delivery and to reduce costs. In this paper, we illustrate how an MRP-type system was developed to monitor surgical linen at a large teaching hospital. We also describe a bar-code scanning 'tag and recapture' study to estimate total inventory. The hospital implemented several changes based upon our recommendations that resulted in time savings and a smoother flow of materials throughout the surgical linen supply chain. PMID:11288482

  2. An investigation into membrane bound redox carriers involved in energy transduction mechanism in Brevibacterium linens DSM 20158 with unsequenced genome.

    Science.gov (United States)

    Shabbiri, Khadija; Botting, Catherine H; Adnan, Ahmad; Fuszard, Matthew; Naseem, Shahid; Ahmed, Safeer; Shujaat, Shahida; Syed, Quratulain; Ahmad, Waqar

    2014-04-01

    Brevibacterium linens (B. linens) DSM 20158 with an unsequenced genome can be used as a non-pathogenic model to study features it has in common with other unsequenced pathogens of the same genus on the basis of comparative proteome analysis. The most efficient way to kill a pathogen is to target its energy transduction mechanism. In the present study, we have identified the redox protein complexes involved in the electron transport chain of B. linens DSM 20158 from their clear homology with the shot-gun genome sequenced strain BL2 of B. linens by using the SDS-Polyacrylamide gel electrophoresis coupled with nano LC-MS/MS mass spectrometry. B. linens is found to have a branched electron transport chain (Respiratory chain), in which electrons can enter the respiratory chain either at NADH (Complex I) or at Complex II level or at the cytochrome level. Moreover, we are able to isolate, purify, and characterize the membrane bound Complex II (succinate dehydrogenase), Complex III (menaquinone cytochrome c reductase cytochrome c subunit, Complex IV (cytochrome c oxidase), and Complex V (ATP synthase) of B. linens strain DSM 20158. PMID:24573306

  3. 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)

  4. 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

  5. Corkscrew Yarns and Chemical Fiber Linen Imitations%碧绉线型与化纤仿麻织物

    Institute of Scientific and Technical Information of China (English)

    李旦

    2001-01-01

    On the basis of analyzing corkscrew-yarn-typed chemical fiberlinen imitations, investigations are made on how to grab market trends and determine design ideas in the development of new products.%通过对碧绉线型的化纤仿麻系列产品的解析,探讨在新产品设计中,怎样把握市场流行动态,确定新产品的设计思路,以期对企业开发新产品有所帮助。

  6. Ability of bed bug-detecting canines to locate live bed bugs and viable bed bug eggs.

    Science.gov (United States)

    Pfiester, Margie; Koehler, Philip G; Pereira, Roberto M

    2008-08-01

    The bed bug, Cimex lectularius L., like other bed bug species, is difficult to visually locate because it is cryptic. Detector dogs are useful for locating bed bugs because they use olfaction rather than vision. Dogs were trained to detect the bed bug (as few as one adult male or female) and viable bed bug eggs (five, collected 5-6 d after feeding) by using a modified food and verbal reward system. Their efficacy was tested with bed bugs and viable bed bug eggs placed in vented polyvinyl chloride containers. Dogs were able to discriminate bed bugs from Camponotus floridanus Buckley, Blattella germanica (L.), and Reticulitermes flavipes (Kollar), with a 97.5% positive indication rate (correct indication of bed bugs when present) and 0% false positives (incorrect indication of bed bugs when not present). Dogs also were able to discriminate live bed bugs and viable bed bug eggs from dead bed bugs, cast skins, and feces, with a 95% positive indication rate and a 3% false positive rate on bed bug feces. In a controlled experiment in hotel rooms, dogs were 98% accurate in locating live bed bugs. A pseudoscent prepared from pentane extraction of bed bugs was recognized by trained dogs as bed bug scent (100% indication). The pseudoscent could be used to facilitate detector dog training and quality assurance programs. If trained properly, dogs can be used effectively to locate live bed bugs and viable bed bug eggs. PMID:18767752

  7. 太行鸡与矮脚麻鸡蛋品质比较研究%Comparative Study between Taihang Chicken and Short-leg-linen Chicken's Egg Quality

    Institute of Scientific and Technical Information of China (English)

    王学静; 魏忠华; 杨树玲; 李祥龙; 李杰峰

    2012-01-01

      Random taking 100 eggs of the 214 day-old introducing breed (Short-leg-linen chichen) and local breed (Taihang chichen) to determine the egg's weight, egg-shaped index, specific gravity, yolk colour, Haugh u-nit , yolk ratio, eggshell thickness, shell strength, flesh and blood spot ratio. The results show that the two breeds' egg quality without significant difference (P>0.05) about the weight , specific gravity, yolk colour, shell thick-ness;But the Haugh unit and the egg yolk rate are very significant difference (P0.05);哈氏单位、蛋黄比率差异极显著(P<0.01);蛋形指数、蛋壳强度差异显著(P<0.05).

  8. of Legends, Denmark. Communicating Culture. Workshop Info 2, 2010, 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 of Lege...... Legends, Denmark. Communicating Culture. Workshop Info 2, 2010......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 of...

  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. Improving reactive ink jet printing via cationization of cellulosic linen fabric.

    Science.gov (United States)

    Rekaby, M; Abd-El Thalouth, J I; Abd El-Salam, Sh H

    2013-11-01

    Cellulose linen fabric samples subjected to cationization using different cationizing agents: dodecyl trimethyl ammonium bromide (DTAB), tetra methyl ammonium hydroxide (TMAH), and Quat-188, via pad batch technique, followed by ink jet printing with reactive dyes. The %N as well as the K/S of the cationized samples was found to be depends on: (a) the nature of the cationizing agent and (b) on the time of batching. As the latter increases both of the nitrogen content and K/S increases to a maximum depending on the nature of the reagent used. Further increase in the batching time up to 30 h is accompanied by a decrease in both the %N and K/S irrespective of the nature of the cationizing agent used. Cationization improves the printability of reactive dye ink jet printed linen fabrics with no remarkable effect on the overall color fastness properties. PMID:24053816

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

    OpenAIRE

    Khadija Shabbiri; Ahmad Adnan; Sania Jamil; Waqar Ahmad; Bushra Noor; H.M. Rafique

    2012-01-01

    Various cultivation parameters were optimized for the production of extra cellular protease by Brevibacterium linens DSM 20158 grown in solid state fermentation conditions using statistical approach. The cultivation variables were screened by the Plackett-Burman design and four significant variables (soybean meal, wheat bran, (NH4)2SO4 and inoculum size were further optimized via central composite design (CCD) using a response surface methodological approach. Using the optimal factors (soybea...

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

    OpenAIRE

    Shabbiri, Khadija; Adnan, Ahmad; Jamil, Sania; Ahmad, Waqar; Noor, Bushra; H.M. Rafique

    2012-01-01

    Various cultivation parameters were optimized for the production of extra cellular protease by Brevibacterium linens DSM 20158 grown in solid state fermentation conditions using statistical approach. The cultivation variables were screened by the Plackett–Burman design and four significant variables (soybean meal, wheat bran, (NH4)2SO4 and inoculum size were further optimized via central composite design (CCD) using a response surface methodological approach. Using the optimal factors (soybea...

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

    Science.gov (United States)

    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.

  14. Dependence of saltation parameters on bed roughness and bed porosity

    Czech Academy of Sciences Publication Activity Database

    Kharlamova, Irina; Vlasák, Pavel

    Prague : ITAM AS CR, v. v. i., 2012 - (Náprstek, J.; Fischer, C.), s. 625-629 ISBN 978-80-86246-40-6. [Engineering Mechanics 2012 /18./. Svratka (CZ), 14.05.2012-17.05.2012] R&D Projects: GA ČR GA103/09/1718 Institutional research plan: CEZ:AV0Z20600510 Keywords : saltation parameters * saltation length * saltation height * bed structure * normal distribution of bed particles * bed roughness Subject RIV: BK - Fluid Dynamics

  15. Container and Raised-Bed Gardening

    OpenAIRE

    Niemiera, Alexander Xavier, 1951-

    2009-01-01

    Raised beds, while requiring a high initial labor input, offer improved growing conditions and advantages compared to the existing soil. Improved plant growth, increased yields, and better accessibility are reasons to construct raised beds. This publication reviews the proper containers and plants, planting instructions, watering and potting soils, overwintering plants and more.

  16. workshop 28-30 June 2010 at Sonnerupgaard and in the Land of Legends, Denmark. Communicating Culture. Workshop Info 2, 2010, 4-6, 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 28-30......-30 June 2010 at Sonnerupgaard and in the Land of Legends, Denmark. Communicating Culture. Workshop Info 2, 2010, 4-6......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...

  17. Nail bed injuries and deformities of nail

    Directory of Open Access Journals (Sweden)

    R Ravindra Bharathi

    2011-01-01

    Full Text Available Nail bed injuries are common and management of these requires good knowledge of the nail bed anatomy. Proper management of these injuries will ensure good healing and prevent late deformities. When loss occurs it is challenging to reconstruct which can be done by grafts or microsurgical reconstruction to restore aesthetic appearance of fingers.

  18. Does Bedding Affect the Airway and Allergy?

    Directory of Open Access Journals (Sweden)

    J Crane

    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.

  19. Incipient motion of gravel and coal beds

    Indian Academy of Sciences (India)

    Subhasish Dey; Uddaraju V Raju

    2002-10-01

    An experimental study on incipient motion of gravel and coal beds under unidirectional steady-uniform flow is presented. Experiments were carried out in a flume with various sizes of gravel and coal samples. The critical bed shear stresses for the experimental runs determined using side-wall correction show considerable disagreement with the standard curves. The characteristic parameters affecting the incipient motion of particles in rough-turbulent regime, identified based on physical reasoning and dimensional analysis, are the Shields parameter, particle Froude number, non-dimensional particle diameter and non-dimensional flow depth. Equations of critical bed shear stress for the initial movement of gravel and coal beds were obtained using experimental data. The method of application of critical bed shear stress equations is also mentioned.

  20. Fluidized bed heating process and apparatus

    Science.gov (United States)

    McHale, Edward J. (Inventor)

    1981-01-01

    Capacitive electrical heating of a fluidized bed enables the individual solid particles within the bed to constitute the hottest portion thereof. This effect is achieved by applying an A. C. voltage potential between dielectric coated electrodes, one of which is advantageously the wall of the fluidized bed rejection zone, sufficient to create electrical currents in said particles so as to dissipate heat therein. In the decomposition of silane or halosilanes in a fluidized bed reaction zone, such heating enhances the desired deposition of silicon product on the surface of the seed particles within the fluidized bed and minimizes undesired coating of silicon on the wall of the reaction zone and the homogeneous formation of fine silicon powder within said zone.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2007-11-15

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

  2. Heat and Mass Transfer Enforcement of Vibrating Fluidized Bed

    Institute of Scientific and Technical Information of China (English)

    ChuZhide; YangJunhong; 等

    1994-01-01

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

  3. Specificity of an extracellular proteinase from Brevibacterium linens ATCC 9174 on bovine alpha s1-casein.

    OpenAIRE

    Rattray, F P; Fox, P. F.; Healy, A.

    1996-01-01

    The specificity of the extracellular proteinase from Brevibacterium linens ATCC 9174 on bovine alpha s1-casein was studied. Hydrolysis was monitored over time by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (PAGE) and urea-PAGE. The major pH 4.6-soluble peptides were isolated by high-performance liquid chromatography and identified by N-terminal amino acid sequencing and mass spectrometry. The time course of peptide formation indicated that His-8-Gln-9, Ser-161-Gly-162, and eithe...

  4. Specificity of an extracellular proteinase from Brevibacterium linens ATCC 9174 on bovine beta-casein.

    OpenAIRE

    Rattray, F P; Fox, P. F.; Healy, A.

    1997-01-01

    The specificity of the extracellular proteinase from Brevibacterium linens ATCC 9174 on bovine beta-casein was studied. Hydrolysis was monitored over time by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (PAGE) and urea-PAGE. The major pH 4.6-soluble peptides were isolated by high-performance liquid chromatography and identified by N-terminal amino acid sequencing and mass spectrometry. The major sites of hydrolysis were Ser-18-Ser-19, Glu-20-Glu-21, Gln-56-Ser-57, Gln-72-Asn-73, ...

  5. Cognitive and emotional functioning in BED

    OpenAIRE

    Kittel, Rebekka; Brauhardt, Anne; Hilbert, Anja

    2016-01-01

    Objective: Binge-eating disorder (BED) is characterized by recurrent episodes of binge eating and is associated with eating disorder and general psychopathology and overweight/obesity. Deficits in cognitive and emotional functioning for eating disorders or obesity have been reported. However, a systematic review on cognitive and emotional functioning for individuals with BED is lacking. Method: A systematic literature search was conducted across three databases (Medline, PubMed, and PsycI...

  6. Peering inside the granular bed: illuminating feedbacks between bed-load transport and bed-structure evolution

    Science.gov (United States)

    Houssais, M.; Jerolmack, D. J.; Martin, R. L.

    2013-12-01

    The threshold of motion is perhaps the most important quantity to determine for understanding rates of bed load transport, however it is a moving target. Decades of research show that it changes in space and in time within a river, and is highly variable among different systems; however, these differences are not mechanistically understood. Recent researchers have proposed that the critical Shields stress is strongly dependent on the local configuration of the sediment bed [Frey and Church, 2011]. Critical Shields stress has been observed to change following sediment-transporting flood events in natural rivers [e.g., Turowski et al., 2011], while small-scale laboratory experiments have produced declining bed load transport rates associated with slow bed compaction [Charru et al., 2004]. However, no direct measurements have been made of the evolving bed structure under bed load transport, so the connection between granular controls and the threshold of motion remains uncertain. A perspective we adopt is that granular effects determine the critical Shields stress, while the fluid supplies a distribution of driving stresses. In order to isolate the granular effect, we undertake laminar bed load transport experiments using plastic beads sheared by a viscous oil in a small, annular flume. The fluid and beads are refractive index matched, and the fluid impregnated with a fluorescing powder. When illuminated with a planar laser sheet, we are able to image slices of the granular bed while also tracking the overlying sediment transport. We present the first results showing how bed load transport influences granular packing, and how changes in packing influence the threshold of motion to feed back on bed load transport rates. This effect may account for much of the variability observed in the threshold of motion in natural streams, and by extension offers a plausible explanation for hysteresis in bed load transport rates observed during floods. Charru, F., H. Mouilleron, and

  7. Bed and breakfasts in Virginia :identification and success factors

    OpenAIRE

    Kaufman, Tammie J

    1994-01-01

    Virginia bed and breakfast operations were researched in order to determine the attitudes/beliefs which were necessary for success in the bed and breakfast industry. The objectives of the study were to: (1) identify demographics of Virginia bed and breakfast operations; (2) identify successful bed and breakfast operations based upon their self definition of success; (3) identify the attitudes and beliefs operators believe are necessary for success in running a bed and breakf...

  8. Hydrodynamics of circulating and bubbling fluidized beds

    International Nuclear Information System (INIS)

    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

  9. 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

  10. 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.

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

    International Nuclear Information System (INIS)

    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.

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

    Science.gov (United States)

    Garcia, Arlene; McGlone, John J

    2014-01-01

    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, 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 feed, at slopes greater than zero, decreased slips, falls and vocalizations. The total time it took to load and unload pigs was affected by bedding type, ramp angle, and season (P pigs improved animal welfare. PMID:26479010

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

    International Nuclear Information System (INIS)

    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

  14. Tinjauan Tentang Pendistribusian Linen Pada Departemen Housekeeping Di Hotel Danau Toba Internasional Medan

    OpenAIRE

    Munthe, Aris Ricardo

    2011-01-01

    Hotel Danau Toba Internasional merupakan salah satu hotel berbintang lima (*****) di kota Medan. Hotel ini mempunyai departemen housekeeping yang memegang tanggungjawab penuh dalam pendistribusian linen. Proses pendistribusian linen masih ditemukan beberapa kekurangan yaitu kurang melaksanakan standar operasional prosedur, sering mengalami keterlambatan dalam tiap shiftnya, mengalami kekurangan tenaga kerja, dan kekurangan parstock dalam memenuhi kebutuhan linnen, dan kurang mengetahui cara m...

  15. FBR and RBR particle bed space reactors

    International Nuclear Information System (INIS)

    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. 100K), high coolant-outlet temperatures (1500 to 30000K, 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 H2-cooled mode. The RBR will operate only in the open-cycle H2-cooled mode

  16. 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

  17. Loading and Unloading Finishing Pigs: Effects of Bedding Types, Ramp Angle, and Bedding Moisture

    OpenAIRE

    Arlene Garcia; McGlone, John J.

    2014-01-01

    Simple Summary Current guidelines suggest the use of ramps below 20 degrees to load and unload pigs; however, they do not suggest the use of any specific bedding. Bedding types (nothing, feed, sand, wood shavings, and hay) were tested with finishing pigs (70–120 kg) to determine which was most effective in reducing slips, falls, and vocalizations at three ramp angles, two moisture levels, over two seasons. Slips, falls, and vocalizations were summed to establish a scoring system for the types...

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

    OpenAIRE

    2014-01-01

    Simple Summary Current guidelines suggest the use of ramps below 20° to load and unload pigs; they do not suggest the use of any specific bedding. Bedding types (nothing, feed, sand, wood shavings, and hay) were tested with four week old weaned pigs to determine which was most effective in reducing slips, falls, and vocalizations at three ramp angles, two moistures, over two seasons. Slips, falls, and vocalizations were summed to establish a scoring system to evaluate treatments. Scores incre...

  19. Loading and Unloading Finishing 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 finishing pigs plays an important role in animal welfare and economics of the pork industry. Currently, the guidelines available only suggest the use of ramps with a slope below 20 degrees to load and unload pigs. However, the total time it takes to load and unload animals and slips, falls, and vocalizations are a welfare concern. Three ramp angles (0, 10 or 20 degrees, 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 = 2400 pig observations and analyzed with a scoring system. The use of bedding during summer or winter played a role in the total time it took to load and unload the ramp (p < 0.05. Bedding, bedding moisture, season, and slope significantly interacted to impact the total time to load and unload finishing pigs (p < 0.05. Heart rate and the total time it took to load and unload the ramp increased as the slope of the ramp increased (p < 0.05. Heart rates were higher during the summer than winter, and summer heart rates increased as the slope increased (p < 0.05. The current study suggests that several factors should be considered in combination to identify the appropriate bedding for the specific occasion.

  20. Prevention and Control of Bed Bugs in Residences

    Science.gov (United States)

    ... on a backpack Bed bugs along a mattress seam Bed bugs on the underside of a box ... Controlling an infestation requires very detailed work, much moving and disassembly of furniture, and specialty equipment. Careful ...

  1. 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. PMID:17867621

  2. Fluidized Bed Asbestos Sampler Design and Testing

    Energy Technology Data Exchange (ETDEWEB)

    Karen E. Wright; Barry H. O' Brien

    2007-12-01

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

  3. 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

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

    Directory of Open Access Journals (Sweden)

    Khadija Shabbiri

    2012-09-01

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

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

    OpenAIRE

    Gallucci, Fausto; Sint Annaland, van, Martin; 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 conversion and the prevailing temperature profiles have been compared. The extent of mass and heat transfer limitations in the different reactors have been evaluated, and strategies to decrease (or avoid) ...

  6. Fluctuations and time scales for bed-load sediment motion over a smooth bed

    Institute of Scientific and Technical Information of China (English)

    Francesco Ballio n; Alessio Radice

    2015-01-01

    Results are presented for experiments of bed-load sediment transport over a plane, smooth bed. The smooth-bed configuration, though not adequate for mimicking natural streams, enables the effects of bed roughness to be filtered out, thus, highlighting the role of flow turbulence for particle dynamics. Sediments were individually tracked along their paths, measuring position and velocity of the individual grains. A number of analyses were then applied to the data: probability density function, auto-correla-tion, and spectra of the grain velocity. Several Lagrangian time scales of particle motion were obtained and compared to available data for the turbulent flow field to determine a phenomenological inter-pretation of the process.

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

    Science.gov (United States)

    Moran, Robert P.

    2013-01-01

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

  8. Experimental comparison of two different ilmenites in fluidized bed and fixed bed chemical-looping combustion

    International Nuclear Information System (INIS)

    Highlights: • Two ilmenite oxygen carriers were tested in fluidized and fixed bed mode. • Activation effects were higher for coarse particles than for small particles. • The final fuel conversion found was higher in the fixed bed for CO and H2 – CH4 was not influenced. • Sintering due to temperature increase during oxidation occurred in the fixed bed. - Abstract: Carbon capture for storage or reuse is seen as one possibility to lower the emissions of anthropogenic CO2. Chemical-looping combustion (CLC) is a promising second generation technique to capture CO2 from thermochemical fuel conversion processes, such as combustion for power generation. The technical implementation of CLC can be conducted using different arrangement approaches based on fluidized or fixed bed reactor designs. When it comes to conversion of solid fuels, the lifetime of an oxygen carrier in a CLC system may be limited by side reactions with fuel ash, or by carryover losses. Therefore, low cost oxygen carriers are preferred. In that context, ilmenite, an iron titanium oxide has been the subject of a number of studies. Here, two ilmenite samples from the Lac Tio mine, Quebec, Canada, extracted from different preparation states were evaluated during activation at 900 °C using a CO–CH4–H2 gas mixture diluted in N2. The experiments were carried out both under fluidized bed and fixed bed conditions to point out qualitative differences. Generally fixed bed reduction indicated higher gas conversion although coarser particles were used. However, if oxidation is carried out in a fixed bed, particle sintering may be a substantial problem

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

    Directory of Open Access Journals (Sweden)

    M. W. Schmeeckle

    2015-02-01

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

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

    Science.gov (United States)

    Schmeeckle, M. W.

    2015-02-01

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

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

    Science.gov (United States)

    Garcia, Arlene; McGlone, John J

    2014-01-01

    The use of non-slip surfaces during loading and unloading of finishing pigs plays an important role in animal welfare and economics of the pork industry. Currently, the guidelines available only suggest the use of ramps with a slope below 20 degrees to load and unload pigs. However, the total time it takes to load and unload animals and slips, falls, and vocalizations are a welfare concern. Three ramp angles (0, 10 or 20 degrees), 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, pig observations) and analyzed with a scoring system. The use of bedding during summer or winter played a role in the total time it took to load and unload the ramp (p pigs (p < 0.05). Heart rate and the total time it took to load and unload the ramp increased as the slope of the ramp increased (p < 0.05). Heart rates were higher during the summer than winter, and summer heart rates increased as the slope increased (p < 0.05). The current study suggests that several factors should be considered in combination to identify the appropriate bedding for the specific occasion. PMID:26479134

  13. Rock bed thermal storage: Concepts and costs

    Science.gov (United States)

    Allen, Kenneth; von Backström, Theodor; Joubert, Eugene; Gauché, Paul

    2016-05-01

    Thermal storage enables concentrating solar power (CSP) plants to provide baseload or dispatchable power. Currently CSP plants use two-tank molten salt thermal storage, with estimated capital costs of about 22-30 /kWhth. In the interests of reducing CSP costs, alternative storage concepts have been proposed. In particular, packed rock beds with air as the heat transfer fluid offer the potential of lower cost storage because of the low cost and abundance of rock. Two rock bed storage concepts which have been formulated for use at temperatures up to at least 600 °C are presented and a brief analysis and cost estimate is given. The cost estimate shows that both concepts are capable of capital costs less than 15 /kWhth at scales larger than 1000 MWhth. Depending on the design and the costs of scaling containment, capital costs as low as 5-8 /kWhth may be possible. These costs are between a half and a third of current molten salt costs.

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

    Energy Technology Data Exchange (ETDEWEB)

    Kevin Whitty

    2003-12-01

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

  15. 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.

  16. CREATIVITY AND TEACHING COMPETENCY OF PROSPECTIVE B.ED TEACHERS

    OpenAIRE

    F. L. Antony GRACIOUS; F. L. Jasmine ANNE SHYLA; ANNARAJA, P.

    2011-01-01

    The present study Creativity and Teaching Competency of prospective B.Ed teachers was probed to find the relationship between Creativity and Teaching Competency of Prospective B.Ed Teachers. Data for the study were collected using self made Teaching Competency Scale and Creativity Scale. The investigator used stratified random sampling technique for selecting the sample. The sample consists of 242 Prospective B.Ed Teachers. For analyzing data; 't' test and Pearson's product moment co-efficien...

  17. A Computational Study of Surface to Bed Heat Transfer and Reactive Flows in Gas Fluidized Beds

    OpenAIRE

    Yusuf, Rahel

    2010-01-01

    This thesis presents the study of surface to bed heat transfer and reactive flows in dense phase gas-fluidized beds. The bulk of the thesis comprises of computational studies although some experimental work is also done in order to validate the model predictions. The computations are performed on the three dimensional, finite volume in-house code FLOTRACS-MP-3D in a Cartesian coordinate system. The in-house code is based on the Eulerian-Eulerian approach which treats the gas and solid phases ...

  18. Pneumatic and Hydraulic Systems in Coal Fluidized Bed Combustor

    OpenAIRE

    Z. O. Opafunso; I. I. Ozigis; I.A. Adetunde

    2009-01-01

    Problem statement: This study designed the pneumatic and hydraulic systems in coal fluidized bed combustor. These are fluidization of silica sand bed material, Air distributor, centrifugal fan, electric motor power drive and surface heat exchanger. Approach: The effects of increased gas velocity on silica sand and the resultant drag force formed the basic equations in fluidization. Air distributor was introduced to achieve pressure drop across the beds. Results: The constructed centrifugal fa...

  19. Design and characterisation of fluidised bed cooling towers

    OpenAIRE

    Mbua Egbe, Louis

    2001-01-01

    This thesis discusses the operating characteristics and design of fluidised bed cooling towers (FBCT), which may be used to cool hot water for industrial purposes. Limited data exist for such a three-phase fluidised bed acting as a cooling tower. This motivated some early workers to investigate its usefulness in cooling tower applications and they showed that the FBCT produces heat and mass transfer rates much higher than in conventional fixed-bed towers. Despite this advantage, the FBCT has ...

  20. Experimental and numerical study of spouted bed fluif dynamics

    OpenAIRE

    C. R. Duarte; V. V. Murata; M. A. S. Barrozo

    2008-01-01

    Spouted beds, originally invented in Canada by Mathur and Gishler (1955) as an alternative to fluidized beds for handling coarse particles, are now widely studied in a variety of physical operations, such as drying, coating and granulation. In this work the particle velocity, minimum spouting flow rate and characteristic fluid-dynamic curves of the spouted bed were obtained using a Eulerian granular multiphase model. The computational work was significantly reduced for axisymmetric gas-solid ...

  1. The characteristics of bed agglomeration/defluidization in fluidized bed firing palm fruit bunch and rice straw

    International Nuclear Information System (INIS)

    The behaviors of bed particle agglomeration and defluidization were investigated during the combustion of oil palm bunch and rice straw in a laboratory scale bubbling fluidized bed reactor. The study focused on (1) the effects of fuel inorganic properties and operating variables on the bed agglomeration tendency and (2) the elucidation in the behaviors of fuel inorganic elements and the governing mode of the agglomeration. It was experimentally found that the defluidization caused by the bed agglomeration was clearly detectable from the decrease of measured bed pressure. The accumulation and growth of the agglomerates provided the partial to complete defluidization. The fuel inorganic composition was the significant influence on the bed agglomeration. The combustion of palm bunch showed higher in the bed agglomeration tendency than the straw combustion in every experimental condition. The defluidization was accelerated in response to the increase in bed temperature and bed particle size, and the decrease of air velocity and static bed height. In the SEM/EDS analysis, the agglomeration was attributed to the formation of the molten substance rich in silicon and fuel derived potassium, likely the potassium silicate compounds, which presented as the adhesive coating and bonding layer. The filling of irregularity on the bed particle surface by the liquid material to form the adhesive layer was dominated by the collision with burning fuel particles. The propagation/reaction inward the bed particles by some reactive constituents was found. The thermodynamic analysis on the ternary phase diagram corroborated that the formation of the liquid material derived from the fuel inorganic elements controlled the agglomeration; the large melt fraction in the adhesive materials at the observed bed temperature range (62–99%) was estimated. - Highlights: • The bed agglomeration was investigated during the FBC of palm bunch and rice straw. • Bed temperature, sand size, air

  2. Fluidized-bed calciner with combustion nozzle and shroud

    International Nuclear Information System (INIS)

    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

  3. CREATIVITY AND TEACHING COMPETENCY OF PROSPECTIVE B.ED TEACHERS

    Directory of Open Access Journals (Sweden)

    F. L. Antony GRACIOUS

    2011-01-01

    Full Text Available The present study Creativity and Teaching Competency of prospective B.Ed teachers was probed to find the relationship between Creativity and Teaching Competency of Prospective B.Ed Teachers. Data for the study were collected using self made Teaching Competency Scale and Creativity Scale. The investigator used stratified random sampling technique for selecting the sample. The sample consists of 242 Prospective B.Ed Teachers. For analyzing data; 't' test and Pearson's product moment co-efficient were the statistical techniques used. Finding shows there was no significant relationship between Creativity and Teaching Competency of prospective B.Ed teachers.

  4. Experimental and numerical study of spouted bed fluif dynamics

    Directory of Open Access Journals (Sweden)

    C. R. Duarte

    2008-03-01

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

  5. FIELD OBSERVATIONS ON BED SEDIMENTS AND SANDWAVES IN CHANGJIANG ESTUARY

    Institute of Scientific and Technical Information of China (English)

    Jiufa LI; Xinning WAN; Ming YING; Xiaohua CHEN

    2005-01-01

    A series of advanced instruments were applied to obtain the field data of bed, bed forms and relevant dynamic factors in the 150 km-long reach of the Changjiang River from Jiangyin to Hengsha Island in March 2002. We found that well-sorted fine sand was in the majority of the bed sediment, which had a median diameter of 2φ. Well-developed sandwaves were formed because the grains jumped together on the bed, which was related to the granularity and current velocity during the flood-ebb tidal cycles.

  6. 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.

  7. Analytical model for freeboard and in-bed limestone sulfation in fluidized-bed coal combustors

    Energy Technology Data Exchange (ETDEWEB)

    Fee, D.C.; Myles, K.M.; Marroquin, G.; Fan, L.S.

    1984-01-01

    A new model, which combines in-bed and freeboard sulfation, significantly improves the ability to predict sulfur capture by limestone sorbents in fluidized-bed coal combustors. In this model, the in-bed hydrodynamics are described in terms of a bubble phase and an emulsion phase while the freeboard region has only a diluted emulsion phase. The solids, which are in the emulsion phases, are considered to be completely back-mixed; the gaseous bubble phase travels in plug-flow but exchanges with the emulsion phase. The sulfation reaction occurs principally in the emulsion phase and the reaction rate is a direct function of the sulfur dioxide concentration, the extent of the calcium oxide conversion (as measured by a thermogravimetric analyzer), and the amount of limestone present in the bed and in the freeboard. The amount present, or holdup, in the free-board is calculated from empirical correlations for elutriation and from particle-time trajectories as predicted from equations of motion. 19 references, 4 figures.

  8. Digital image analysis measurements of bed expansion and segregation dynamics in dense gas-fluidized beds

    NARCIS (Netherlands)

    Goldschmidt, M.J.V.; Link, J.M.; Mellema, S.; Kuipers, J.A.M.

    2003-01-01

    One of the most crucial steps in the development of fundamental hydrodynamic models is the validation of these models with accurate, detailed experimental data. Therefore a whole-field, non-intrusive digital image analysis technique has been developed which enables measurement of bed expansion and s

  9. The Influence of Salmonid Spawning on Grain Architecture, Critical Bed Shear Stress, and Bed Load Transport in Streams

    Science.gov (United States)

    Buxton, T.; Buffington, J. M.; Yager, E. M.; Fremier, A. K.; Hassan, M. A.

    2012-12-01

    Salmonid spawning occurs in many high to mid-order streams in North America and Europe, but the detailed mechanics of this disturbance on stream bed mobility is not well studied. We calculated and measured spawning effects on incipient bed mobility and sediment transport in a laboratory flume and found that the tailspill portion of simulated spawning nests ("redds") are less stable than unspawned beds. This result agrees with field research by others, but counters prior calculations of tailspill stability that used grain architecture relationships derived from unspawned beds. Redds have coarser and better sorted surfaces, which reduce grain exposure and protrusion compared to unspawned beds, but load cell measurements of the total resistance to movement of grains on redds were lower despite deeper grain pockets and larger pivot angles. This is because the redd-building process flushed fine sediment that had previously cemented bed material, resulting in a looser bed structure and more mobile grains. These observations are supported by force balance calculations of critical shear stress on redds being lower on average than on unspawned beds. Computational results are supported by visual observations and measurements of bed load transport from redds and unspawned beds in the flume, where redds mobilized sooner and exhibited a higher sediment transport rate than unspawned beds. Redds were observed to erode by translating, then dispersing and evacuating downstream, before grains on the unspawned bed mobilized. Further increase in discharge mobilized greater proportions of the unspawned bed but did not scour the deeper portion of redds where spawners deposit their eggs. Our results suggest both an evolutionary trade-off and advantage to large spawning populations. Namely, the structurally loose tailspill likely increases intragravel flow to eggs at the expense of tailspill instability, which may sufficiently elevate sediment yields in streams with high spawner densities

  10. Soft-bed experiments beneath Engabreen, Norway: Regelation, infiltration, basal slip and bed deformation

    Science.gov (United States)

    Iverson, N.R.; Hooyer, T.S.; Fischer, U.H.; Cohen, D.; Moore, P.L.; Jackson, M.; Lappegard, G.; Kohler, J.

    2007-01-01

    To avoid some of the limitations of studying soft-bed processes through boreholes, a prism of simulated till (1.8 m ?? 1.6 m ?? 0.45 m) with extensive instrumentation was constructed in a trough blasted in the rock bed of Engabreen, a temperate glacier in Norway. Tunnels there provide access to the bed beneath 213 m of ice. Pore-water pressure was regulated in the prism by pumping water to it. During experiments lasting 7-12 days, the glacier regelated downward into the prism to depths of 50-80 mm, accreting ice-infiltrated till at rates predicted by theory. During periods of sustained high pore-water pressure (70-100% of overburden), ice commonly slipped over the prism, due to a water layer at the prism surface. Deformation of the prism was activated when this layer thinned to a sub-millimeter thickness. Shear strain in the till was pervasive and decreased with depth. A model of slip by ploughing of ice-infiltrated till across the prism surface accounts for the slip that occurred when effective pressure was sufficiently low or high. Slip at low effective pressures resulted from water-layer thickening that increased non-linearly with decreasing effective pressure. If sufficiently widespread, such slip over soft glacier beds, which involves no viscous deformation resistance, may instigate abrupt increases in glacier velocity.

  11. 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

  12. 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 res

  13. 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 res

  14. Predicting bed load transport of sand and gravel on Goodwin Creek

    Science.gov (United States)

    Bed load transport rates are difficult to predict in channels with bed material composed of sand and gravel mixtures. The transport of bed load was measured on Goodwin Creek, and in a laboratory flume channel with a similar bed material size distribution. The range of bed load transport rates meas...

  15. Sludge reed bed facilities: operation and problems.

    Science.gov (United States)

    Nielsen, S

    2005-01-01

    Short operating periods and problems with dewatering efficiency, vegetation, mineralisation and odour are primarily caused by incorrect construction of the filter, poor capillary connections, an inadequate number of basins, insufficient basin area and overloading during commissioning and during subsequent operation. Dimensioning should be based on the sludge quality including the dewatering qualities and not solely on calculations of the sludge production. Loading after planting depends on the development level of the vegetation. The loading program should ensure that reed establishment is not impeded and should prevent the sludge residue from growing so quickly horizontally and vertically that the reeds cannot colonise the sludge residue. Overloading results in an anaerobic sludge residue with ensuing methane production. Typically, a sludge reed bed facility with a loading period of maximum 5 days, must be built with 10 basins to permit a rest phase of about 40 days. Facilities with 8 basins, where it is possible to load 1 basin for 7 days, will be able to have a 7-week rest phase before the first basin is loaded again. Facilities with for example 8-13 basins and loading period of between 4 and 10 days are able to achieve rest periods of up to 2 to 2(1/2) months, which results in the optimal evapotranspiration and minerilization. The conditions and thus the possibilities vary depending upon the type of sludge. PMID:16042248

  16. Study of heat transfer between an over-bed oil burner flame and a fluidized bed during start-up: Determination of the flame to bed convection coefficient

    International Nuclear Information System (INIS)

    A study of the heat transfer processes between an over-bed burner flame and a fluidized bed during start-up as been conducted. Owing to the difficulty of estimating the flame to bed convection coefficient in an industrial boiler, convection coefficients were determined using a laboratory bench scale unit. Such convection heat transfer coefficients are obtained for 3 kg, 4 kg and 5.5 kg initial bed inventories by combining measured temperatures and flow rates with a mathematical model representing the complex energy exchange in the system. Results show that the height of the fluidized bed and its distance to the flame are an important factor in the overall heat transfer process, both by convection and radiation. For 5.5 kg, 4 kg and 3 kg initial bed inventories, the convection coefficients obtained, at the end of start-up, are 180 ± 30 W/m2 K, 150 ± 20 W/m2 K and 95 ± 10 W/m2 K respectively. The determined convection coefficients can be utilized in the future as guides in the design of start-up systems for BFB boilers. The energy analysis performed also identified the major sources of heat losses in the bubbling fluidized bed.

  17. Effect of bed temperature and bed composition on agglomeration during gasification of high-sodium, high-sulphur lignite in a spouted fluidised bed

    Energy Technology Data Exchange (ETDEWEB)

    D.P. McCullough; P.J. Mullinger; P.J. Ashman [University of Adelaide, Adelaide, SA (Australia). Cooperative Research Centre for Clean Power from Lignite, School of Chemical Engineering

    2003-07-01

    Fluidised bed gasification (FBG) is an alternative process for coal utilisation that delivers improved efficiencies and lower temperature operation compared to conventional technology. Agglomeration and defluidisation are phenomena that have the potential to occur within fluidised bed reactors, which can interrupt stable process operation. While extensive work has been carried out investigating fluidised bed combustion of lignite, relatively little work has been carried out for lignite under fluidised bed gasification conditions. Gasification of high sodium, high sulphur content lignite in a spouted bed gasifier (SBG) indicates that agglomeration and defluidisation is only an issue when maximum bed temperature exceeds approximately 850{degree}C and air/fuel ratios of 2.5 outside of these conditions, defluidisation is not detected. It is also demonstrated that defluidisation occurs before agglomeration, rather than as a result of agglomeration as previously thought. The Rosin-Rammler method of describing particle size distribution is found to yield appropriate variables for quantification of the extent of agglomeration taking place in cases where defluidisation is a factor. However, it has been shown by this method that while initial results indicated that agglomeration extent varies directly with maximum bed temperature, further results have shown that other variables, such as superficial velocity, have a significant impact on the extent of agglomeration. Investigations are currently continuing. 9 refs., 8 figs., 9 tabs.

  18. The Effects of Agitated Beds Homogenization on Stirrer Geometry and Bed Depth via DEM

    OpenAIRE

    Kohout, M.

    2014-01-01

    In this contribution open source DEM particle simulation software LIGGGHTS was studied and tested. Collision forces are there modelled by the softsphere approach with the Hertzian collision model. As an application we studied agitated particle beds (packed from glass spherical particles of two colours – packed vertically and horizontally) mixed by different types of agitators. Dependence of degree of homogenization on particle diameter, particle properties (Young’s modulus), and on geometric...

  19. Pebble bed pebble motion: Simulation and Applications

    CERN Document Server

    Cogliati, Joshua J

    2011-01-01

    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, P...

  20. Uncertainty and sensitivity analysis of filling fraction of pebble bed in pebble bed HTR

    International Nuclear Information System (INIS)

    Highlights: • An analysis approach is proposed to conduct SAU analysis of filling fraction of pebble bed core. • The contribution of uncertainty in filling fraction to key parameters of pebble bed core is quantified. • The primary drivers of the uncertainty in the key parameters are identified by sensitivity analysis. • Mechanism of effect of uncertainty in the filling fraction to key parameters is studied in depth. - Abstract: The filling fraction of pebble bed in each small region has some uncertainty, which will contribute to the total uncertainty in the key parameters of pebble bed core, such as power peak, axial offset, keff and so on. In fact, the heavy metal content and graphite content of the corresponding region will change synchronously due to the perturbation of filling fraction but the ratio of atomic number density of moderator to the fuel (carbon–uranium) is still constant. To investigate these effects, the Chinese demonstration plant HTR-PM was selected as the research object and the VSOP code and CUSA package were used to conduct detailed analysis of the influence of the uncertainty in the filling fraction on the HTR-PM output variables of interest, based on the propagation of input uncertainties by using statistical sampling method to calculate uncertainty and sensitivity information from the simulation results. At the same time, uncertainty and sensitivity analysis of uranium loading had also been conducted for comparative analysis to study the mechanism of effect of uncertainty in the filling fraction to key parameters, and therefore only the heavy metal content of the corresponding region changes in the presence of perturbation of uranium loading. Finally, the propagated uncertainty in the power peak, axial offset and keff of HTR-PM core was obtained and the primary drivers of the uncertainty in the key parameters were identified by sensitivity analysis

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

    International Nuclear Information System (INIS)

    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

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

    Energy Technology Data Exchange (ETDEWEB)

    Nietert, R.E.

    1983-02-01

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

  3. Experimental studies and CFD simulations of conical spouted bed hydrodynamics

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Z.

    2008-07-01

    This thesis involved both experimental research and mathematical modelling of the hydrodynamics of conical spouted beds. Although conical spouted beds are commonly used for drying suspensions, solutions and pasty materials, they can also be used for catalytic partial oxidation of methane to synthesis gas, coal gasification and liquefaction, and pyrolysis of sawdust. Pressure transducers and static pressure probes were used in the experimental studies to investigate the evolution of the internal spout and the local static pressure distribution. Optical fibre probes were used to measure axial particle velocity profiles and voidage profiles. The gas mixing behaviour inside a conical spouted bed was examined using a step trace injection technique in which helium was used as the tracer and thermal conductivity cells were used as the detectors. For the mathematical modelling, a stream-tube model based on the bed structure inside a conical spouted bed was proposed to simulate partial spouting states. An adjustable parameter was introduced into the model to enable total pressure drop prediction under different operating conditions, and to estimate axial superficial gas velocity profiles and gauge pressure profiles. A mathematical model based on characteristics of conical spouted beds and FLUENT software was also developed and validated using measured experimental data. The proposed CFD model can simulate both stable spouting and partial spouting states, with an adjustable solids-phase source term. The effect of all possible factors on simulation results were investigated, including the fluid inlet profile, solid bulk viscosity, frictional viscosity, restitution coefficient, exchange coefficient, and solid phase source term. In addition to simulating the gas mixing behaviours inside a conical spouted bed, the new CFD model simulated cylindrical packed beds and cylindrical fluidized beds in one code package.

  4. A DU bed system for storing and supplying hydrogen isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Koo, Daeseo; Park, Jongchul; Ahn, Do-Hee; Chung, Hongsuk [KAERI, Daejeon (Korea, Republic of); Yun, Sei-Hun [National Fusion Research Institute, Daejeon (Korea, Republic of)

    2015-05-15

    Depleted uranium (DU) has been extensively proposed for the storage, supply, and recovery of hydrogen isotopes. SDS is used for storing hydrogen isotopes as a metal hydride form. To control the SDS, it is necessary to monitor the tritium amount in a bed. In this study, a full-sized DU bed was designed and fabricated including cylindrical-type copper foam of nine layers to study the characteristics of hydriding/dehydriding and simulate the tritium amount in a bed. The integrity and leak inspection on the welding of a primary vessel was performed using a penetration test, helium leak test, and pressure test. Auto tuning on the cable heaters of two pairs in the DU bed was also be performed. In our next study, the hydriding/dehydriding on a DU bed will be performed. A simulation on the depleted uranium hydriding will be carried out. A DU bed was designed and fabricated including cylindrical-type copper foam of nine layers to study the characteristics of hydriding/dehydriding and simulate the tritium amount in a bed. Through a penetration test, it was confirmed that the welding of the primary vessel has a good integrity. It was confirmed that the two helium tubes is sound by inspecting a helium leak test on the welding of the primary vessel. It was also confirmed that the primary vessel has a good integrity by inspecting a helium leak and conducting a pressure test on it. Vacuuming of the DU bed system was carried out. Vacuuming of the in-bed calorimetric equipment was also carried out.

  5. Ancient ice streams and their megalineated beds

    Science.gov (United States)

    Eyles, Nick; Ross, Martin

    2016-06-01

    Ice streams are corridors of fast-flowing (~ 800 m yr- 1) ice inset within otherwise sluggish-moving ice sheets. According to reported estimates, as much as 90% of the total discharge of the Antarctic Ice Sheet, for example, occurs through such corridors. Recognition of ice stream records in paleo-ice sheet research has profoundly changed the discipline of glacial geology. The key has been identification of the distinctive corrugated or 'megalineated' geomorphology of their beds, consisting of elongate ridges that are parallel to ice flow direction and often transitional to drumlins. Access to new satellite imagery has enabled mapping of megascale glacial lineations (MSGLs) over large swaths of terrain and the recognition of regional-scale ice stream flow paths and origins. At the peak of the last ice age, just after 20,000 years ago, there were more than 100 ice streams within the Laurentide Ice Sheet. Only now are we beginning to fully appreciate the fundamental role that such streams (which have been called the 'arteries' of ice sheets) have had on glaciated landscapes, by moving enormous volumes of sediment and releasing armadas of floating ice to the Arctic and Atlantic oceans. There is also a growing awareness of the erosional role of ice streams in overdeepening of lakes, fiords and other troughs along coastlines. Much remains to be learnt and new discoveries surely await. The picture of past ice sheets, like the Laurentide and Fennoscandian Ice Sheets, that is emerging today is very different from that of 20 years ago.

  6. Sunlamps and Sunlamp Products (Tanning Beds/Booths)

    Science.gov (United States)

    ... Radiation-Emitting Products and Procedures Home, Business, and Entertainment Products Sunlamps and Sunlamp Products (Tanning Beds/Booths) Share ... PDF - 71KB) [ARCHIVED] More in Home, Business, and Entertainment Products Cell Phones Health Issues Reducing Exposure: Hands-free ...

  7. Flow and combustion characteristics of a 2-dimensional spouted bed

    Science.gov (United States)

    Sawyer, R. F.; Hart, J. R.; Ohtake, K.

    1982-03-01

    A two dimensional spouted bed laboratory combustor was designed and constructed with the objective of studying the interaction among the gas flow, particle flow, and combustion. The facility, designed for a maximum thermal power of 20 kW, has a quartz front wall providing full optical access to particle flows and combustion processes. The combustor was characterized in terms of pressure, temperature, gas velocity, and particle velocity profiles and operating limits. Initial studies employed premixed propane and air and a fixed bed height, bed material, injector slot width, and combustor geometry. As in previous investigations of axisymmetric spouted beds, the ratio of particle mass circulation rate to jet mass flow rate was observed to be about ten. Combustion increased this ratio by about 10%. A pulsating mode of operation was noted with a characteristic frequency of about 10 Hz, controlled by the interaction of the particle and gas flows.

  8. RELATING WEIGHT AND COUNT DISTRIBUTIONS OF STREAM BED GRAVEL

    Science.gov (United States)

    The size distribution of particles in a stream bed reflects the stream hydrology as well as its physical and chemical water quality characteristics. In environmental assessments, gravel distribution determines habitat quality for aquatic insects and stream suitability for spawnin...

  9. Northern and Central Appalachian region assessment: The Pittsburgh coal bed

    Energy Technology Data Exchange (ETDEWEB)

    Ruppert, L.; Tewalt, S.; Bragg, L. [Geological Survey, Reston, VA (United States)

    1996-12-31

    Approximately 40% of the Nation`s coal is produced in the six states (Ohio, Pennsylvania, West Virginia, Maryland, Virginia, and Kentucky) that occupy parts of the Northern and Central Appalachian region. Coal is, and will continue to be, the primary energy commodity in this region where more than 50 coal beds and coal zones are currently being mined. About one-half of the productions is from just eight coal beds or zones. Three of these, the Pittsburgh and Upper Freeport coal beds and the Kittanning coal zone, are located in the northern part of the region. The remaining beds or zones, the Pond Creek, Fire Clay, Alma, Upper Elkhorn No. 3, and the Pocahontas No. 3, are located primarily in the central part of the region. This study is designed to utilize the data and expertise existing within the USGS and the State Geological Surveys to produce bed-specific, digital, coal resource assessments for most of the top-producing coal beds and coal zones. Unlike past USGS assessments, this study will emphasize not only the quantity of coal but also the quality of the coal. Particular attention will be paid to the geochemical parameters that are thought to adversely effect combustion characteristics and possibly have adverse effects on the environment, including ash yield, sulfur, calorific value, and, the elements listed in the 1990 Clean Air Act Amendments. Geochemical databases produced for the assessed beds will be augmented by new, representative, coal analyses of major, minor, and trace elements. Products will include stratigraphic and geochemical data bases, original and remaining source calculations, and comprehensive digital maps at a scale of 1:250,000 or 1:500,000 of crop-line, coal thickness, coal structure, overburden thickness, mined-out areas, and geochemistry for each assessed coal beds.

  10. Model of Fluidized Bed Containing Reacting Solids and Gases

    Science.gov (United States)

    Bellan, Josette; Lathouwers, Danny

    2003-01-01

    A mathematical model has been developed for describing the thermofluid dynamics of a dense, chemically reacting mixture of solid particles and gases. As used here, "dense" signifies having a large volume fraction of particles, as for example in a bubbling fluidized bed. The model is intended especially for application to fluidized beds that contain mixtures of carrier gases, biomass undergoing pyrolysis, and sand. So far, the design of fluidized beds and other gas/solid industrial processing equipment has been based on empirical correlations derived from laboratory- and pilot-scale units. The present mathematical model is a product of continuing efforts to develop a computational capability for optimizing the designs of fluidized beds and related equipment on the basis of first principles. Such a capability could eliminate the need for expensive, time-consuming predesign testing.

  11. Trends and Determinants of Time in Bed in Geneva, Switzerland

    OpenAIRE

    Gubelmann C.; Guessous I.; Theler J.M.; Haba-Rubio J.; Gaspoz J.M.; Marques-Vidal P

    2014-01-01

    STUDY OBJECTIVES: There is limited information regarding sleep duration and determinants in Switzerland. We aimed to assess the trends and determinants of time in bed as a proxy for sleep duration in the Swiss canton of Geneva. METHODS: Data from repeated, independent cross-sectional representative samples of adults (≥ 18 years) of the Geneva population were collected between 2005 and 2011. Self-reported time in bed, education, monthly income, and nationality were assessed by questionna...

  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. PMID:7916869

  13. 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.

  14. Bed capacity and surgical waiting lists: a simulation analysis

    Directory of Open Access Journals (Sweden)

    Manel Antelo

    2015-12-01

    Full Text Available Waiting time for elective surgery is a key problem in the current medical world. This paper aims to reproduce, by a Monte Carlo simulation model, the relationship between hospital capacity, inpatient activity, and surgery waiting list size in teaching hospitals. Inpatient activity is simulated by fitting a Normal distribution to real inpatient activity data, and the effect of the number of beds on inpatient activity is modelled with a linear regression model. Analysis is performed with data of the University Multi-Hospital Complex of Santiago de Compostela (Santiago de Compostela, Spain, by considering two scenarios regarding the elastiticity of demand with bed increase. If demand does not grow with an increase on bed capacity, small changes lead to drastic reductions in the waiting lists. However, if demand grows as bed capacity does, adding additional capacity merely makes waiting lists worse.

  15. Method of purifying oil and bed water from hydrogen sulfide

    Energy Technology Data Exchange (ETDEWEB)

    Dyadechko, V.N.; Kuzovatkin, R.I.; Nesterov, I.N.; Stavitskiy, B.P.

    1982-01-01

    A method is proposed for purifying oil and bed water of hydrogen sulfide by treatment with a chemical reagent. It is distinguished by the fact that in order to prevent the formation of corrosion-aggressive side products and sulfate-reducing bacteria, in the bed water the chemical reagent complex compounds of copper-hexaamine copper (II) hydroxide or tetraamine copper (II) hydroxide are used in the form of 0.05% aqueous solution.

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

    International Nuclear Information System (INIS)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2000-03-31

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

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

    Energy Technology Data Exchange (ETDEWEB)

    AYALA, R E; VENKATARAMANI, V S

    1998-09-30

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

  19. Properties of Concrete Incorporating Bed Ash from Circulating Fluidized Bed Combustion and Ground Granulates Blast-furnace Slag

    Institute of Scientific and Technical Information of China (English)

    CHENG An; HSU Hui-Mi; CHAO Sao-Jeng

    2011-01-01

    The properties of concrete incorporating circulating fluidized bed combustion (CFBC) bed ash and ground granulates blast-furnace slag (GGBS) were studied. Compressive strength,drying shrinkage, mercury intrusion porosimetry (MIP), scanning electronic microscopy (SEM), and X-ray diffraction (XRD) of concrete samples containing CFBC bed ash and GGBS were used. This work used initial surface absorption test (ISAT) and rapid chloride penetration test (RCPT) on concrete to measure the absorption and the ability of concrete to resist chloride ion characteristics for different concrete samples containing CFBC bed ash and GGBS. Open circuit potential (OCP), direct current polarization resistance were obtained to evaluate rebar corrosion. The CFBC bed ash was X-ray amorphous and consist of SiO2, A12O3 and CaO compounds. As the replacement of CFBC for sand increases, the rate of initial surface absorption (ISA) increases but compressive strength decreases.When the content of CFBC bed ash replacement for sand maintains constant, the replacement of GGBS for cement increases, compressive strength increases but the rate of ISA decreases. Chloride and corrosion resistance of rebar significantly improve by utilizing a proper amount of CFBC bed ash and GGBS in concrete.

  20. ITER Tritium Storage and Delivery Bed Development and Test

    International Nuclear Information System (INIS)

    The ITER fuel cycle plant is composed of various subsystems such as a fuel storage and delivery system (SDS), a tokamak exhaust processing system (TEP), and a hydrogen isotope separation system (ISS). The main purpose of the SDS is to store and supply the D-T gas needed for the DT plasma operation. Korea shares in the construction of the ITER fuel cycle plant with the EU, Japan and US, and is responsible for the development and supply of the SDS. We have developed an SDS bed and tested not only its performance for a hydrogen delivery and recovery but also its in-bed calorimetric performance

  1. Bedded salt in Ontario : geology, solution mining and cavern storage

    Energy Technology Data Exchange (ETDEWEB)

    Carter, T. [Ontario Ministry of Natural Resources, London, ON (Canada). Petroleum Resources Centre

    2009-07-01

    This presentation discussed bedded salt geology in Ontario in relation to cavern storage and solution mining. Ontario's salt basin forms part of the Michigan basin. The salt formed as reefs surrounding the shallow basin restricted the flow of water. Salt then formed as the water evaporated. The bedded salt occurs in several layers underlying up to 16,000 km{sup 2} in the province. Subsurface resources used in the area include salt cavern hydrocarbon storage; oil and gas reservoirs; and natural gas reservoir storage. The Salina Group stratigraphy is comprised of several separate salt beds with a maximum combined thickness of 90 m. The Salina salt beds exhibit evidence of dissolution after deposition. There are currently 20 active solution mining wells in operation in the Windsor and Goderich regions. There are currently 112 wells and 70 caverns used for cavern storage in Ontario that are used to store approximately 27 million bbl of liquefied petroleum gas (LPG) and oil. Non-salt layers in the salt beds can interfere with both solution mining and cavern storage operations. tabs., figs.

  2. Bacterial counts associated with sawdust and recycled manure bedding treated with commercial conditioners.

    Science.gov (United States)

    Hogan, J S; Bogacz, V L; Thompson, L M; Romig, S; Schoenberger, P S; Weiss, W P; Smith, K L

    1999-08-01

    Bacteria counts associated with untreated organic bedding materials were compared with those of bedding treated with either an alkaline commercial bedding conditioner, acidic commercial bedding conditioner, or hydrated lime. Bedding materials were recycled manure and kiln-dried sawdust. The effects of bedding treatments on bacteria counts differed between bedding types. Each of the bedding treatments significantly reduced bacteria in recycled manure prior to use. The alkaline conditioner and hydrated lime effectively inhibited bacteria in recycled manure for 1 d. Bedding counts and teat swabs of cows housed on recycled manure treated with the alkaline conditioner were reduced on d 2. The use of the acid conditioner in recycled manure had little effect on bacteria in bedding. Sawdust differed from recycled manure in that bacteria in untreated sawdust prior to use were minimal, and populations increased rapidly during the first 2 d after use as bedding. The acid conditioner had a bacteriostatic effect in sawdust, evident by the reduction of bacteria on d 2. The alkaline conditioner and hydrated lime did not alter bacteria counts in sawdust compared with untreated sawdust. Antibacterial activity of each conditioner deteriorated between d 2 and d 6 in both beddings. The antibacterial activities of conditioners were related to the pH of bedding materials. The use of commercial bedding conditioners initially reduced bacterial counts; however, the antibacterial effects had diminished between d 2 and 6 after use in bedding. PMID:10480094

  3. 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

  4. Modelling of seed drying in fluidised and spouted bed dryers

    OpenAIRE

    Jittanit, W.; Srzednicki, G.; Driscoll, R

    2010-01-01

    Drying experiments were conducted in the fluidised bed dryer (FBD) and spouted bed dryer (SBD) at temperature 40-80°C using maize, rice and wheat seed samples. The experimental data were fitted into four thin-layer drying models by least square method. As a result, Page’s model and two-compartment model were the best-fitted models. Due to the limitation of these models, Page’s model and the twocompartment model were modified by adding the drying temperature term. Subsequently, these models co...

  5. Effect and surfactants on three-phase fluidized bed hydrodynamics

    International Nuclear Information System (INIS)

    Experiments were conducted to discern the relationship between three-phase fluidized bed hydrodynamics and surfactant solution characteristics. The standard characteristic, equilibrium surface tension, is inadequate. A novel method for surface tension evaluation, a dynamic maximum bubble pressure technique, was found to differentiate the 12 different solutions studied. The surfactant solutions were categorized based upon a combination of the terminal bubble rise velocity reduction, the equilibrium surface tension, and the new bubble tension values. These surfactant solution categories were correlated with experimentally observed three-phase fluidized bed and bubble column hydrodynamic behavior. Specifically, empirical correlations for gas holdup are presented

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

    Directory of Open Access Journals (Sweden)

    Narinderpal Singh

    2013-11-01

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

  7. A fixed granular-bed sorber for measurement and control of alkali vapors in PFBC (pressurized fluidized-bed combustion)

    Energy Technology Data Exchange (ETDEWEB)

    Lee, S.H.D.; Swift, W.M.

    1990-01-01

    Alkali vapors (Na and K) in the hot flue gas from the pressurized fluidized-bed combustion (PFBC) of coal could cause corrosion problems with the gas turbine blades. In a laboratory-scale PFBC test with Beulah lignite, a fixed granular bed of activated bauxite sorbent was used to demonstrate its capability for measuring and controlling alkali vapors in the PFBC flue gas. The Beulah lignite was combusted in a bed of Tymochtee dolomite at bed temperatures ranging from 850 to 875{degrees}C and a system pressure of 9.2 atm absolute. The time-averaged concentration of sodium vapor in the PFBC flue gas was determined from the analysis of two identical beds of activated bauxite and found to be 1.42 and 1.50 ppmW. The potassium vapor concentration was determined to be 0.10 ppmW. The sodium material balance showed that only 0.24% of the total sodium in the lignite was released as vapor species in the PFBC flue gas. This results in an average of 1.56 ppmW alkali vapors in the PFBC flue gas. This average is more than 1.5 orders of magnitude greater than the currently suggested alkali specification limit of 0.024 ppm for an industrial gas turbine. The adsorption data obtained with the activated bauxite beds were also analyzed mathematically by use of a LUB (length of unused bed)/equilibrium section concept. Analytical results showed that the length of the bed, L{sub o} in centimeters, relates to the break through time, {theta}{sub b} in hours, for the alkali vapor to break through the bed as follows: L{sub o} = 33.02 + 1.99 {theta}{sub b}. This formula provides useful information for the engineering design of fixed-bed activated bauxite sorbers for the measurement and control of alkali vapors in PFBC flue gas. 26 refs., 4 figs., 4 tabs.

  8. 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)

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

    International Nuclear Information System (INIS)

    The Savannah River Site (SRS) tritium facilities have used first generation (Gen1) LaNi4.25Al0.75 (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)

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

    Energy Technology Data Exchange (ETDEWEB)

    Klein, J.; Estochen, E.

    2014-03-06

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

  11. Fluid Bed Technology: Overview and Parameters for Process Selection

    Directory of Open Access Journals (Sweden)

    Saurabh Srivastava

    2010-10-01

    Full Text Available Formulation development is the most emerging and upcoming face of pharmaceutical technology in the current era. It is contemporarily capturing the market leaps and bounds with recent trends and developments with its innovative techniques. The day-to-day advancements in the research have provided an edge to this brilliant branch of pharmaceutical sector for not only uplifting the pharmacy profession but also to conquer the diseased state for nurturing the health and humanity. The fluid-bed technology or air-suspension process is the potential tool to develop newer trends and implications in the sector of formulation development with maximum therapeutic efficacy. The technology is used for granulation/agglomeration, layering and coating of a wide range of particle size. In addition; the technique can be used for the drying process as well. The three patterns of the fluid-bed processes could be characterized by the position/location of the spray nozzle i.e. top spray, bottom spray or tangential spray. This article reviews the three techniques with some innovative fluid bed pelletizing technologies like CPS™, MicroPx™, ProCell™ and discusses their applications, advantages and limitations. These advanced pelletizing technologies are recentely added to complement the actual capabilities of standard fluid bed processing for development of various dosage forms of “Multiple Unit Particulate Systems” (MUPS with better therapeutic efficacy and economic benefits.

  12. Model for boiling and dryout in particle beds

    International Nuclear Information System (INIS)

    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

  13. Strength regain in soil aggregate beds by swelling and shrinkage

    Directory of Open Access Journals (Sweden)

    R. Horn

    2006-06-01

    Full Text Available Strength regain in aggregate beds as a consequence of wetting and drying cycles was studied in two Andisols and one Mollisol from Chile, collected at two depths (0-10 and 40-60 cm. In the Mollisol, wetting and drying cycles promoted an increase of mechanical parameters (cohesion and precompression stress value, associated with increase of bulk density. The Andisols showed the same tendency, but in some coarse aggregate beds the measured values decreased or remained constant. After six cycles of wetting and drying, the restructuring of the aggregate beds from the Mollisol resembled more the measured properties of non-disturbed samples than the identically prepared samples from the Andisols. The change of pore water pressure during mechanical tests depends on the soil development: the Mollisol is sensitive to external load, during compression and shear tests the pore water pressure changed intensely, while in the younger Andisol, irrespective of the stress applied, the pore water pressure did not change significantly. It is possible to find a strength regain in natural aggregate beds, but further investigations are necessary to understand the processes of pore formation and functioning in Andisols and their role in the pore water pressure behaviour.

  14. Packed bed heat storage: Continuum mechanics model and validation

    Science.gov (United States)

    Knödler, Philipp; Dreißigacker, Volker; Zunft, Stefan

    2016-05-01

    Thermal energy storage (TES) systems are key elements for various types of new power plant concepts. As possible cost-effective storage inventory option, packed beds of miscellaneous material come into consideration. However, high technical risks arise due to thermal expansion and shrinking of the packed bed's particles during cyclic thermal operation, possibly leading to material failure. Therefore, suitable tools for designing the heat storage system are mandatory. While particle discrete models offer detailed simulation results, the computing time for large scale applications is inefficient. In contrast, continuous models offer time-efficient simulation results but are in need of effective packed bed parameters. This work focuses on providing insight into some basic methods and tools on how to obtain such parameters and on how they are implemented into a continuum model. In this context, a particle discrete model as well as a test rig for carrying out uniaxial compression tests (UCT) is introduced. Performing of experimental validation tests indicate good agreement with simulated UCT results. In this process, effective parameters required for a continuous packed bed model were identified and used for continuum simulation. This approach is validated by comparing the simulated results with experimental data from another test rig. The presented method significantly simplifies subsequent design studies.

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

    Science.gov (United States)

    Environmental stressors, such as high fly density, can impact 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 conducte...

  16. Dynamics and mechanics of bed-load tracer particles

    Science.gov (United States)

    Phillips, C. B.; Jerolmack, D. J.

    2014-12-01

    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.

  17. Modelling of thermal and mechanical behaviour of pebble beds

    International Nuclear Information System (INIS)

    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)

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

    Science.gov (United States)

    Greenleaf, J. E.

    1997-01-01

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

  19. 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

  20. Investigation of debris bed formation, spreading and coolability

    International Nuclear Information System (INIS)

    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

  1. 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.

  2. EFFECT OF VERTICAL BAFFLES ON PARTICLE MIXING AND DRYING IN FLUIDIZED BEDS OF GROUP D PARTICLES

    Institute of Scientific and Technical Information of China (English)

    Chung Lim Law; Siti Masrinda Tasirin; Wan Ramli Wan Daud; Derek Geldart

    2003-01-01

    This study reports the effect of vertical baffles on the group D powder mixing and drying characteristics in a batch fluidized bed dryer. Results obtained in this study showed that operating the fluidized bed dryer with vertical baffles gave better particle mixing. This is due to the fact that the vertical baffles acted to limit the growth of small bubbles into large bubbles and the small bubbles caused more vigorous mixing in the bed of particles before finally erupting at the bed surface. Thus, insertion of vertical baffles is a useful way to process group D particles in a fluidized bed, especially when the fluidized bed is large.

  3. 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. PMID:26603379

  4. Experimental determination of bed agglomeration tendencies of some common agricultural residues in fluidized bed combustion and gasification

    Energy Technology Data Exchange (ETDEWEB)

    Natarajan, E.; Rao, A.N. [Anna University, Madras (India). Centre for New and Renewable Sources of Energy; Ohman, M.; Nordin, A. [Umea University (Sweden). Energy Technology Centre; Gabra, M. [Lulea University of Technology (Sweden). Div. of Energy Engineering; Liliedahl, T. [Royal Institute of Technology, Stockholm (Sweden). Dept. of Chemical Engineering and Technology

    1998-12-31

    Ever increasing energy demand and the polluting nature of existing fossil fuel energy sources demonstrate the need for other non-polluting and renewable sources of energy. The agricultural residues available in abundance in many countries can be used for power generation. The fluidized bed technology seems to be suitable for converting a wide range of agricultural residues into energy, due to its inherent advantages of fuel flexibility, low operating temperature and isothermal operating condition. The major ash-related problem encountered in fluidized beds is agglomeration which, in the worst case, may result in total defluidization and unscheduled downtime. The initial agglomeration temperature for some common tropical agricultural residues were experimentally determined by using a newly developed method based on the controlled fluidized bed agglomeration test. The agricultural residues chosen for the study were rice husk, bagasse, cane trash and olive flesh. The results showed that the initial agglomeration temperatures were less than the initial deformation temperature predicted by the ASTM standard ash fusion tests for all fuels considered. The initial agglomeration temperatures of rice husk and bagasse were more than 1000{sup o}C. The agglomeration of cane trash and olive flesh was encountered at relatively low temperatures and their initial agglomeration temperatures in gasification were lower than those in combustion with both bed materials. The use of lime as bed material instead of quartz improved the agglomeration temperature of cane trash and olive flesh in combustion and decreased the same in gasification. The results indicate that rice husk and bagasse can be used in the fluidized bed for energy generation since their agglomeration temperatures are sufficiently high. (author)

  5. Sleeping arrangements and mass distribution of bed nets in six districts in central and northern Mozambique

    OpenAIRE

    Plucinski, M. M.; Chicuecue, S.; Macete, E.; Chambe, G. A.; Muguande, O.; Matsinhe, G.; Colborn, J.; Yoon, S. S.; Doyle, T J; Kachur, S. P.; Aide, P; Alonso, P. L.; Guinovart, C.; Morgan, J.

    2015-01-01

    OBJECTIVE: Universal coverage with insecticide-treated bed nets is a cornerstone of modern malaria control. Mozambique has developed a novel bed net allocation strategy, where the number of bed nets allocated per household is calculated on the basis of household composition and assumptions about who sleeps with whom. We set out to evaluate the performance of the novel allocation s...

  6. Bed bugs and possible transmission of human pathogens: a systematic review.

    Science.gov (United States)

    Lai, Olivia; Ho, Derek; Glick, Sharon; Jagdeo, Jared

    2016-10-01

    The global population of bed bugs (Cimex lectularius and Cimex hemipterus, family Cimicidae) has undergone a significant resurgence since the late 1990s. This is likely due to an increase in global travel, trade, and the number of insecticide-resistant bed bugs. The global bed bug population is estimated to be increasing by 100-500 % annually. The worldwide spread of bed bugs is concerning, because they are a significant socioeconomic burden and a major concern to public health. According to the United States Environmental Protection Agency, bed bugs are "a pest of significant health importance." Additionally, 68 % of U.S. pest professionals reported that bed bugs are the most challenging pest to treat. Upwards of 45 disease pathogens have been reported in bed bugs. Recent studies report that bed bugs may be competent vectors for pathogens, such as Bartonella quintana and Trypanosoma cruzi. However, public health reports have thus far failed to produce evidence that major infectious disease outbreaks have been associated with bed bugs. Since many disease pathogens have previously been reported in bed bugs and the worldwide bed bug population is now drastically increasing, it stands to reason to wonder if bed bugs might transmit human pathogens. This review includes a literature search on recently published clinical and laboratory studies (1990-2016) investigating bed bugs as potential vectors of infectious disease, and reports the significant findings and limitations of the reviewed studies. To date, no published study has demonstrated a causal relationship between bed bugs and infectious disease transmission in humans. Also, we present and propose to expand on previous hypotheses as to why bed bugs do not transmit human pathogens. Bed bugs may contain "neutralizing factors" that attenuate pathogen virulence and, thereby, decrease the ability of bed bugs to transmit infectious disease. PMID:27295087

  7. Emissions from multiple-spouted and spout-fluid fluidized beds using rice husks as fuel

    Energy Technology Data Exchange (ETDEWEB)

    Albina, D.O. [School of Engineering and Architecture, Mindanao Polytechnic State College, Cagayan de Oro City 9000 (Philippines)

    2006-10-15

    This paper presents the experimental results of the emissions of CO and CO{sub 2} using rice husks as fuel on different configurations of spout-fluidized beds namely, multiple-spouted and spout-fluid fluidized bed. The emission of pollutants from the multiple-spouted bed and spout-fluid bed was investigated with rice husk fuel. The operating parameters considered were the different levels of excess air, different primary-to-secondary air ratios at each level of excess air and method of feeding. It was found that emission of CO from the multiple-spouted bed seemed to be lower with under-bed feeding of the rice husk fuel compared to over-bed feeding. However, the emission of CO{sub 2} did not change significantly for both methods of feeding. Changes in excess air levels influenced the emissions of CO and CO{sub 2} from the multiple-spouted bed within the excess air range investigated. It was found that emission of CO was less at 10% excess air with over-bed feeding; emission of CO in the case of under-bed feeding was lowest at 20% excess air level. It was found that the method of feeding had not significantly influenced the emission of CO and CO{sub 2} in the spout-fluid bed. The combustion efficiency however, in general, was slightly higher in the case of under-bed feeding compared to over-bed feeding. Emission of CO was less in the spout-fluid bed compared with the emission of CO in the multiple-spouted bed. The result can be likely attributed to the higher combustion efficiency attained by the spout-fluid bed compared with that of multiple-spouted bed. (author)

  8. Woody waste air gasification in fluidized bed with Ca- and Mg-modified bed materials and additives

    International Nuclear Information System (INIS)

    This study focuses on the promotion of biomass gasification for hydrogen production in a fluidized bed reactor with the bed additives zeolite, CaO, and Ca- and Mg-based silica sands. The results show that zeolite has higher capacity for enhancing hydrogen promotion abilities than CaO with the amount was 200 g in tests. Regarding the Ca- and Mg-based silica sands, Ca/SiO2 decreases the CO2 selectivity and Mg/SiO2 enhances the H2 selectivity owing to CO2 adsorption via the formation of CaO and the promotion of the water gas shift reaction, respectively. The optimal concentration of Mg-based bed materials corresponds to a Mg concentration of 0.5 wt.%. The additives play important roles in increasing the reaction rate, enhancing the biomass gasification, and promoting carbon transformation. -- Graphical abstract: The aim of this study is not only in estimation of the influence of the alkaline metals concentrations, but also in preparation of the modified fluidization mediums. A basic stoichiometric analysis of alkaline concentration for hydrogen production during biomass gasification in fluidized bed is also in consideration. Highlights: ► Various bed-additives concentrations on syngas performance are discussed. ► All additives significantly increase rate of hydrogen production in gasification. ► Zeolite has higher capacity for enhancing hydrogen production rate than CaO. ► Ca-based additives promoted the heating value and cold gas efficiency. ► The optimal concentration of Mg-based additive was 0.5 wt.% for hydrogen production

  9. Modeling and field observations of char bed processes in black liquor recovery boilers

    Energy Technology Data Exchange (ETDEWEB)

    Engblom, M.

    2010-07-01

    The char bed plays an important role in kraft black liquor combustion. Stable operation of the char bed promotes efficient and safe operation of the black liquor recovery boiler. It also plays a crucial role in the recovery of the pulping chemicals. Char bed operation involves controlling the char bed size and shape. Mathematical modeling based on computational fluid dynamics (CFD) haas been applied to recovery boilers for increased insights into the recovery furnace processes and to aid in the design of new boilers. So far, all CED-based char bed models reported in literature have used a fixed bed shape. This imposes restrictions on simulation of char bed burning by not considering inherently occurring changes in bed shape. In this thesis, a CED -based recovery furnace model is further developed to predict changes in bed shape. The new model is used in simulation of existing recovery boilers. The predictions of bed shape are compared with observations from real boilers. The furnace model is capable of correctly simulating the overall response of the char bed size to operational changes. This confirms the current quantitative overall understanding of char bed burning. In addition to modeling, visual observations of the char bed processes were made in this work. The observations provide validation data concerning the physical behavior of the char bed, and the findings from the observations can be used in further development of char bed models. Modeling and simulations of fundamental laboratory scale char bed experiments reported in literature are also carried out. The simulations complement the experimental data by providing detailed insights into gas phase reactions that can occur inside the gas boundary layer above a char bed. (orig.)

  10. Comparative studies of a circulating fluidized bed and a stationary fluidized bed

    International Nuclear Information System (INIS)

    The objectives of the test were to compare the CFB to the SFB in order to learn how they perform with various fuels, especially how the smaller fractions of the fuel influence the combustion and the NOx-emissions. The fuels used were whole and crushed peat as well as forestry waste with and without woodchips. The SFB handled all the tested fuels well at emission levels of 60-90 mg/MJfuel. The lowest levels were maintained with uncrushed peat. This CFB only performed well with uncrushed peat. Hence this is the only fuel of the ones tested impossible to feed the ordinary way. During the test uncrushed peat was fed directly into the boilerhouse bin. The reason is the variable flow of fine material generating carbon monoxide. The fine material is also transported to the cyclone and is finally burned there. Therefore the cyclone temperature is higher for fine particles than for uncrushed peat at a certain bed temperature. In the SFB, the injection level of the air influenced the NOx-emissions. When both secondary and tertiary air was used, the NOx-emission decreased from 150 to 80 mg/MJfuel. This effect is probably due to lower and more even combustion temperature in the top of the furnace. When forestry refuse is used, the tertiary air tends to increase the CO-emission. In the CFB, the NOx-emission is proportional to the cyclone temperature and the oxygen level. For practical reasons, such as possible oxygen level with CO and cyclone temperature due to fine material, the NOx-level is different, but knowing the oxygen and cyclone temperature it is possible to predict the NOx-emission. With peat as fuel the carbon residue content in the fly ash was higher in the SFB compared to the CFB. (Orig.). (3 refs., numerous figs. and tabs.)

  11. Application of ultrasonic backscattering for level measurement and process monitoring of expanded-bed adsorption columns.

    Science.gov (United States)

    Thelen, T V; Mairal, A P; Thorsen, C S; Ramirez, W F

    1997-01-01

    Expanded-bed adsorption is a newly commercialized technique for the purification of proteins from cellular debris in downstream processing. An expanded bed presents the possibility of protein recovery in a single step, eliminating the often costly clarification processing steps such as ultrafiltration, centrifugation, and precipitation. A major obstacle to the successful commercialization of this technology is the inability to accurately monitor and control the bed height in these systems. Fluctuations in the feedstock viscosity are common during normal operation and tend to make the operation and control of expanded beds for biological applications complex and difficult. We develop a level measurement technique based upon ultrasonics. It is shown that this technique has great promise for bed-height measurement in expanded-bed adsorption systems. Furthermore, the bed-height measurement can be used in feedback control strategies for bed-height regulation. The proposed ultrasonic sensor is also capable of monitoring for plugging and bubbling in the column. PMID:9336988

  12. Sand Bed Morphodynamics under Standing Waves and Vegetated Conditions

    Science.gov (United States)

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

    2010-12-01

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

  13. Median ja urheilun välinen suhde : Urheilu ja urheilijat mediassa

    OpenAIRE

    Mäkelä, Kalle; Pirttimäki, Olli

    2010-01-01

    Kalle Mäkelä & Olli Pirttimäki. Median ja urheilun välinen suhde. Urheilu ja urheilijat mediassa, Turku, syksy 2010, 68 s., 2 liitettä. Diakonia-ammattikorkeakoulu, Diak Länsi, Turun toimipaikka, viestinnän koulutusohjelma, medianomi (AMK). Opinnäytetyömme tarkoitus on selvittää, millä tavalla media vaikuttaa huippu-urheilijan työhön. Julkisessa ammatissa toimivan ihmisen on jatkuvasti oltava tietoinen omasta käytöksestään. Tutkielmamme keskittyy urheilijoiden ja median väliseen suhte...

  14. Tapahtuman järjestäminen : kansainvälinen bachatafestivaali

    OpenAIRE

    Salo, Susanna

    2009-01-01

    Opinnäytetyöni tarkoitus on kuvailla, miten kansainvälinen bachatafestivaali eli Finland 2nd International Bachata Festival järjestettiin Tampereelle ja Helsinkiin kesäkuussa 2009. Bachata on romanttinen musiikki- ja tanssityyli Dominikaanisesta tasavallasta. Tapahtuma järjestettiin toista kertaa, mutta ensimmäistä kertaa uudella konseptilla, isompana tapahtumana kahdessa kaupungissa. Tarkoituksena oli tutkia myös tapahtuman järjestäjän motiiveja tapahtuman järjestämiseen sekä tapahtuma...

  15. Study of Solids and Gas Distribution in Spouted Bed Operated In Stable and Unstable Conditions

    OpenAIRE

    G. M. Alwan; Aradhya, S.B

    2014-01-01

    A spouted bed is a special case of fluidization. It is an effective means of contacting gas with coarse solid particles. Spouted beds should be designed and operated to overcome performance instability and improves the uniform distribution of particles. Steady-state measurements were carried out in the 0.152 m ID cylindrical spouted bed made of Plexiglas that used 60° conical shape spout-air bed. The evaluation of solid and gas holdup in the two regions of spouted bed at stabl...

  16. Learning from drivers and conflicts around bedded pack barns

    OpenAIRE

    Galama, P.J.; Dooren, van, H.J.C.; Eilers, C.H.A.M.

    2012-01-01

    Due to problems with the freestall a network of dairy farmers in the Netherlands started looking for alternative housing systems for dairy cattle. Therefore researchers and dairy farmers shared ideas and looked abroad in America and Israel for housing systems without cubicles. This gave inspiration for deep bedded pack systems like in these countries. The drivers (motivations) for these housing systems were animal welfare and manure quality. However, they had to be made suitable for the Dutch...

  17. Dissolved organic carbon fluxes by seagrass meadows and macroalgal beds

    OpenAIRE

    Barrón, Cristina; Apostolaki, Eugenia T.; Duarte, Carlos M.

    2014-01-01

    Estimates of dissolved organic carbon (DOC) release by marine macrophyte communities (seagrass meadows and macroalgal beds) based on in situ benthic chambers from published and unpublished are compiled in this study. The effect of temperature and light availability on DOC release by macrophyte communities was examined. Almost 85% of the seagrass communities and all of macroalgal communities examined acted as net sources of DOC. Net DOC fluxes in seagrass communities increase positively with w...

  18. Evolution of bed form height and length during a discharge wave

    OpenAIRE

    Warmink, J.J.; Schielen, R.M.J.; Dohmen-Janssen, C.M.; Lancker, van, V.; Garlan, T.

    2013-01-01

    This research focusses on modeling the evolution of bed form during a discharge wave for application in operational flood forecasting. The objective of this research was to analyze and predict the bed form evolution during a discharge wave in a flume experiment. We analyzed the data of a flume experiment and show that dune length is determined by development of secondary bed forms during the receding limb of the discharge wave. Secondly, three models were compared to predict the bed form evol...

  19. Sleeping arrangement and house structure affect bed net use in villages along Lake Victoria

    Directory of Open Access Journals (Sweden)

    Maekawa Yoshihide

    2010-06-01

    Full Text Available Abstract Background Although insecticide-treated bed nets are effective tools, use often does not follow ownership. House structure and space arrangements may make the attempt to use bed nets difficult, especially for school age children. The objectives of this study were to explore whether an individual's sleeping arrangements and house structure affect bed net use in villages along Lake Victoria in western Kenya. Methods Sleeping arrangements of residents were directly observed for use of a bed net, use of a bed, and location. House size, number and types of rooms, bed availability, and residents' ages were estimated. The family heads and mothers were asked about the reason for not using bed nets. Individual bed net use was examined against age and sleeping arrangement. Net use at the household level was examined against four variables: bed availability, bed net availability, house size, and number of rooms. Results Bed net use by children between five and 15 years of age was lower than that among the other age classes. However, age was dropped from the final model, and sleeping arrangement was significantly associated with net use. Net use was significantly associated with bed availability, number of rooms and their interaction. Conclusion Net use was affected by sleeping arrangement and availability of suitable locations for hanging nets, in addition to net availability. Most residents had likely not realized that sleeping arrangement was a factor in net use. The ease of hanging a net is particularly important for children.

  20. Analysis and control of an anaerobic upflow Fixed bed bioreactor

    International Nuclear Information System (INIS)

    This paper presents the bifurcation analysis in an anaerobic upflow fixed bed bioreactor, which is an anaerobic digestion system useful for wastewater treatment. In the dynamic analysis part, the equilibrium points, linear stability and bifurcation curves are studied, focusing in the washout condition. For the self tuning regulator the parameter estimation and control law are designed, and an integral action is introduced in order to address the disturbances. The simulation studies show the improvement of the performance when a disturbance appears.

  1. Production of medicated bedding straw: challenges and perspectives

    OpenAIRE

    Solan, Patrick J.; Valdramidis, Vasilis P.; Androny, Camille; O'Donnell, C. P. (Colm P.); Scannell, Amalia G. M.; Curran, Thomas P.; et al.

    2011-01-01

    Previous bacteriological findings have reported that animal disease outbreaks are associated with the quality of the animal environment. Animal bedding straw is a good source of bacteria and fungi, typically contaminated with (mycelia) yeasts and filamentous fungi species such as Aspergillus, Fusarium, Alternaria, Cladosporium, Epicoccum, Penicillium, Verticillium and Enterobacteria. The objective of this work was to assess the efficacy of different technologies on the production of medica...

  2. Thorium and plutonium utilisation in pebble-bed modular reactor

    International Nuclear Information System (INIS)

    Thorium and plutonium utilisation in a high temperature gas-cooled pebble-bed reactor is investigated with the aim to predict the economic value of vast thorium reserves in Turkey. A pebble-bed reactor of the type designed by PBMR Pty. of South Africa is taken as the investigated system. The equilibrium core of a PBMR is considered and neutronics analyses of such a core are performed through the use of the SCALE-4.4 computer code system KENOV.a module. Various cross-section libraries are used to calculate the criticality of the core. Burn-up calculations of the core are performed by coupling the KENOV.a module with the ORIGEN-S module. Calculations are carried out for various U-Th, U-Pu-Th and U-Pu combinations. The results are preliminary in nature and the work is currently proceeding as planned. (author)

  3. Vertical media bed filter and method of cleaning filter panels

    International Nuclear Information System (INIS)

    A vertical media bed dust collector in which the media bed of a filter panel is rejuvenated when necessary by interrupting the gas flow through the panel, withdrawing the filter media from the panel] separating the agglomerated dust from the filter media, returing the filter media to the filter panel, and reestablishing the gas flow through the panel. The system further includes apparatus for removing collected dust from the deparating and recirculating surfaces of the media handling apparatus and also from the remote face of the filter panels before the cleaned gas is allowed to pass out of the collector so that the cleaned gas is not recontaminated by small amounts of dust adhering to those surfaces

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-07-15

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

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

    International Nuclear Information System (INIS)

    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

  6. 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

  7. Experiments and Modelling of Coal Pyrolysis under Fluidized Bed Conditions

    Institute of Scientific and Technical Information of China (English)

    ZhangYongzhe; XuXiangdong; 等

    1999-01-01

    The pyrolysis behavior of two Chinese coals has been investigated in a laboratory-scale bubbling fluidized bed system in Siegen University,Germany,Experimental equipment and procedure are introduced.The amounts of pyrolysis species of each coal were measured,calcuated and compared.A new method was presented to determine the needed parameters in FG-DVC model with the experimental results instead of other much more complicated experiments.

  8. Numerical Modeling and Prediction of Bubbling Fluidized Beds

    OpenAIRE

    England, Jonas Andrew

    2011-01-01

    Numerical modeling and prediction techniques are used to determine pressure drop, minimum fluidization velocity and segregation for bubbling fluidized beds. The computational fluid dynamics (CFD) code Multiphase Flow with Interphase eXchange (MFIX) is used to study a two-stage reactor geometry with a binary mixture. MFIX is demonstrated to accurately predict pressure drop versus inlet gas velocity for binary mixtures. A new method is developed to predict the pressure drop versus inlet gas v...

  9. Bed capacity and surgical waiting lists: a simulation analysis

    OpenAIRE

    Manel Antelo; Francisco Reyes Santias; Adela Martinez Calvo

    2015-01-01

    Waiting time for elective surgery is a key problem in the current medical world. This paper aims to reproduce, by a Monte Carlo simulation model, the relationship between hospital capacity, inpatient activity, and surgery waiting list size in teaching hospitals. Inpatient activity is simulated by fitting a Normal distribution to real inpatient activity data, and the effect of the number of beds on inpatient activity is modelled with a linear regression model. Analysis is performed with data o...

  10. Ecological functions of intertidal seagrass beds for fishes and mobile epibenthos in the northern Wadden Sea

    OpenAIRE

    Polte, Patrick

    2004-01-01

    Seagrass beds are worldwide known to represent important habitats for fishes and invertebrates. Most investigations of the role of seagrass beds as habitats for animal assemblages were carried out in subtidal zones, whereas only little information is available on intertidal seagrass beds. However, different ecological functions are to be expected between both systems.This study was to investigate whether intertidal seagrass beds fulfil vital ecological functions for common North Sea fishes an...

  11. Mineralogy and chemistry of conventional and fluidised bed coal ashes

    Directory of Open Access Journals (Sweden)

    Sulovský P

    2002-03-01

    Full Text Available Coal combustion residues represent very abundant inorganic waste materials. The change from conventional combustion of powdered North Bohemian brown coal to its combustion in fluidised bed boilers in several Czech power and heating plants calls for detailed mineralogical and geochemical characterisation of the combustion residues. The main differences between fly ashes from both combustion systems result from different burning temperatures and differing systems of desulphurisation (coeval with combustion / post-combustion. Both these factors influence the chemical and phase compositions as well as the speciation of trace elements. The study further shows that the validity of the surface enrichment model (Linton et al. 1975 can be limited.

  12. Pneumatic and Hydraulic Systems in Coal Fluidized Bed Combustor

    Directory of Open Access Journals (Sweden)

    Z. O. Opafunso

    2009-01-01

    Full Text Available Problem statement: This study designed the pneumatic and hydraulic systems in coal fluidized bed combustor. These are fluidization of silica sand bed material, Air distributor, centrifugal fan, electric motor power drive and surface heat exchanger. Approach: The effects of increased gas velocity on silica sand and the resultant drag force formed the basic equations in fluidization. Air distributor was introduced to achieve pressure drop across the beds. Results: The constructed centrifugal fan was driven by selected electric motor based on pressure and temperature changes in the reactor. The dimensions of the heat transfer tube were calculated from fluid flow and energy balance equations. The values obtained were as the follows: Fluidization velocity (1.54 m sec-­1, gas velocity through orifice (29.52 m sec-1, the fan electric motor (2 KW, 3 ph at 1500 pm, the steam temperature obtained was 160°C from water ambient temperature of 30°C and tube length 22 m was coiled into levels in the combustor. Conclusion/Recommendation: Precise specifications of pneumatic and hydraulic systems will adequately address the environment concern of coal fired power supply as a method to address epileptic power supply in Nigeria.

  13. Attrition of sorbents during fluidized bed calcination and sulphation

    Energy Technology Data Exchange (ETDEWEB)

    Scala, F.; Salatino, P. [Naples Univ. (Italy). Dipartimento di Ingegneria Chimica; Boerefijn, R.; Ghadiri, M. [Surrey Univ., Guildford (United Kingdom). Dept. of Chemical and Process Engineering

    2000-01-24

    The attrition behavior of two different limestones during calcination and sulphation in fluidized beds as been investigated by a combination of experimental techniques. The aim of the study is to shed light on the interactions between sorbent attrition and the change of particle mechanical and morphological properties associated with the progress of chemical reactions. A number of different experimental techniques have been used to characterize breakage mechanisms relevant to particle attrition in different sections of industrial fluidized bed reactors operated at atmospheric pressure. Primary fragmentation and abrasive attrition were characterized in situ by means of experiments carried out in a bench-scale fluidized bed reactor operated batchwise. Fragmentation under high velocity impact conditions was studied ex situ by means of single particle impact tests on pre-conditioned samples at room temperature. Scanning electron and optical microscopy analyses of the particles and EDX mapping of polished particle cross-sections were used to relate topography and internal composition of sorbent particles to the attrition mechanism. (orig.)

  14. 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.

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

    International Nuclear Information System (INIS)

    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

  16. Fluidized bed and method and system for gas component capture

    Energy Technology Data Exchange (ETDEWEB)

    Krutka, Holly; Wilson, Cody; Starns, Travis

    2016-05-31

    The present disclosure is directed to a process that allows dry sorbents to remove a target constituent, such as carbon dioxide (CO.sub.2), from a gas stream. A staged fluidized bed separator enables gas and sorbent to move in opposite directions. The sorbent is loaded with target constituent in the separator. It is then transferred to a regenerator where the target constituent is stripped. The temperature of the separator and regenerator are controlled. After it is removed from the regenerator, the sorbent is then transferred back to the separator.

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

    Energy Technology Data Exchange (ETDEWEB)

    Jarungthammachote, S.; Dutta, A. [Energy Field of Study, School of Environment, Resources and Development, Asian Institute of Technology, P.O. Box 4, Klongluang, Pathumthani 12120 (Thailand)

    2008-06-15

    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{sub 2}, CH{sub 4}, H{sub 2}O, H{sub 2} and N{sub 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. (author)

  18. 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.

  19. Microbial biomass and productivity in seagrass beds

    Science.gov (United States)

    Moriarty, D. J.; Boon, P. I.; Hansen, J. A.; Hunt, W. G.; Poiner, I. R.; Pollard, P. C.; Skyring, G. W.; White, D. C.

    1985-01-01

    Different methods for measuring the rates of processes mediated by bacteria in sediments and the rates of bacterial cell production have been compared. In addition, net production of the seagrass Zostera capricorni and bacterial production have been compared and some interrelationships with the nitrogen cycle discussed. Seagrass productivity was estimated by measuring the plastochrone interval using a leaf stapling technique. The average productivity over four seasons was 1.28 +/- 0.28 g C m-2 day-1 (mean +/- standard deviation, n = 4). Bacterial productivity was measured five times throughout a year using the rate of tritiated thymidine incorporated into DNA. Average values were 33 +/- 12 mg C m-2 day-1 for sediment and 23 +/- 4 for water column (n = 5). Spatial variability between samples was greater than seasonal variation for both seagrass productivity and bacterial productivity. On one occasion, bacterial productivity was measured using the rate of 32P incorporated into phospholipid. The values were comparable to those obtained with tritiated thymidine. The rate of sulfate reduction was 10 mmol SO4(-2) m-2 day-1. The rate of methanogenesis was low, being 5.6 mg CH4 produced m-2 day-1. A comparison of C flux measured using rates of sulfate reduction and DNA synthesis indicated that anaerobic processes were predominant in these sediments. An analysis of microbial biomass and community structure, using techniques of phospholipid analysis, showed that bacteria were predominant members of the microbial biomass and that of these, strictly anaerobic bacteria were the main components. Ammonia concentration in interstitial water varied from 23 to 71 micromoles. Estimates of the amount of ammonia required by seagrass showed that the ammonia would turn over about once per day. Rapid recycling of nitrogen by bacteria and bacterial grazers is probably important.

  20. Healthcare Facility Bed Types And Counts

    Data.gov (United States)

    U.S. Department of Health & Human Services — The California Department of Public Health (CDPH), Center for Health Care Quality, Licensing and Certification (L&C) Program licenses more than 30 types of...

  1. The suitability of horse manure and bedding materials for combustion

    Energy Technology Data Exchange (ETDEWEB)

    Tyni, S.; Tiainen, M. S.; Laitinen, R. S. (Univ. of Oulu, Dept. of Chemistry (Finland)). email: sanna.tyni@oulu.fi

    2009-07-01

    The number of horses has increased in Finland since 1994 approximately by 2000 horse/ year and 2008 there was almost 70000 registered horses and ponies in Finland. This has derived to a considerable number of new stables at city area where the waste management, particularly of the mixture of manure and bedding material, is a challenge. These stables have disposed their residues often by land filling. The present legislation prohibits the dispose of organic material by land filling since the anaerobic decomposition emits for example methane that is a greenhouse gas. The legislation also regulates using of manure as fertilizer in fields. This leads to the situation where stable owners have urge for new ways to dispose of residues. In Finland peat, sawdust, and straw are commonly used as a bedding material for horses in stable boxes. The more important function of the bedding material is to keep the boxes dry and clean by absorbing urine. The selection of bedding material depends on the properties of the materials such as availability, price, absorption capacity, and hygiene properties. Composting of sawdust is slower than peat, therefore mixture of manure and sawdust is not preferred for utilization as fertilizer. Additionally use of the manure residues as fertilizers is limited by impurities such as plant seeds in manure. Combustion would be attractive way to solve disposal problems of the mixture of manure and bedding materials. At the moment legislation in Finland defines manure residues as a waste. Therefore the combustion is only allowed in waste combustion units. If the combustion of the manure residues would be allowed at farms or at small local boilers, it enables farms to have better degree of self-sufficiency of energy. The utilization of these new materials as a fuel demands study of combustion properties of these biomasses. It is also essential to have knowledge of chemical composition and behaviour of ashes, when the final disposing is considered e.g. as

  2. Dimensional similitude and the hydrodynamics of three- phase fluidized beds

    Science.gov (United States)

    Safoniuk, Michael

    It is proposed that scaling of three-phase fluidized bed hydrodynamics can be carried out based on geometric similarity and matching of a set of five dimensionless groups: (i)the M-group, M = g.Δρ.μ L4/(ρL2.σ 3); (ii)an Eötvös number, Eo = g.Δρ.d p2/σ (iii)the liquid Reynolds number, Re L = ρL.dp.UL/μ L; (iv)a density ratio, βd = ρp/ρ L; and (v)a superficial velocity ratio, βu = U g/UL. These were varied in an experimental study where four dimensionless hydrodynamic parameters were measured: (i)gas hold-up, ɛ g; (ii)bed expansion ratio, βbe (iii)the ratio of mean bubble diameter to particle diameter, db/dp ; and (iv)the ratio of mean bubble rise velocity to gas superficial velocity, Ub/Ug. This approach was validated experimentally by matching the dimensionless operating conditions from a kerosene-nitrogen-ceramic three-phase system with those in an aqueous magnesium sulphate solution-air-aluminum particle fluidized bed. There was good agreement between the gas hold-ups and bed expansion ratios in the two systems. A pilot-plant scale cold-flow co-current upwards-flowing three-phase fluidized bed column of inside diameter 292 mm was built and operated using three different liquids (tap water, an aqueous 44 mass % glycerol solution, and an aqueous 60 mass % glycerol solution), air, and cylindrical aluminum particles of diameter 4 mm and length 10 mm. The fluids and solids were carefully selected to result in dimensionless group values in the range of those of an industrial hydroprocessor. Specially built conductivity probes and pressure transducers were used to measure the hydrodynamic properties for different gas and liquid superficial velocities. Special attention was required to provide for drift and calibration when recording and analyzing data from the conductivity probes. Gas hold-ups were in the range of 5 to 20% by volume and were correlated as a function of liquid-phase Reynolds number and superficial velocity ratio. The gas hold-ups were a

  3. 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. PMID:27065410

  4. Potential of Essential Oil-Based Pesticides and Detergents for Bed Bug Control.

    Science.gov (United States)

    Singh, Narinderpal; Wang, Changlu; Cooper, Richard

    2014-12-01

    The bed bug, (Cimex lectularius L.), is a difficult pest to control. Prevalence of insecticide resistance among bed bug populations and concerns over human-insecticide exposure has stimulated the development of alternative bed bug control materials. Many essential oil-based pesticides and detergent insecticides targeting bed bugs have been developed in recent years. We evaluated the efficacy of nine essential oil-based products and two detergents using direct spray and residual contact bioassays in the laboratory. Two conventional insecticides, Temprid SC (imidacloprid and β-cyfluthrin) and Demand CS (λ-cyhalothrin), were used for comparison. Among the 11 nonsynthetic insecticides tested, only EcoRaider (1% geraniol, 1% cedar extract, and 2% sodium lauryl sulfate) and Bed Bug Patrol (0.003% clove oil, 1% peppermint oil, and 1.3% sodium lauryl sulfate) caused >90% mortality of nymphs in direct spray and forced exposure residual assays. However, the efficacy of EcoRaider and Bed Bug Patrol was significantly lower than that of Temprid SC and Demand CS in choice exposure residual bioassay. Direct spray of EcoRaider caused 87% egg mortality, whereas the other nonsynthetic insecticides had little effect on bed bug eggs. EcoRaider and Bed Bug Patrol did not exhibit detectable repellency against bed bugs in the presence of a carbon dioxide source. These findings suggest that EcoRaider and Bed Bug Patrol are potentially useful pesticides for controlling bed bug infestations, but further testing in naturally infested environments is needed. PMID:26470082

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

    Directory of Open Access Journals (Sweden)

    M. M. Prado

    2008-03-01

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

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

    International Nuclear Information System (INIS)

    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 C10–C28. • 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 (⩽C44), olefins (⩽C22), aromatics (⩽C14) and alcohols (C16 and C17) 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 feedstock. 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

    influence on temperature and humidity. The discomfort associated with bed nets is likely to be most intolerable during the hottest and most humid period of the year, which frequently coincides with the peak of malaria vector densities and the force of pathogen transmission. Conclusions These observations......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...... for one night from 21.00 to 6.00 hrs inside and outside of bed nets using sensors and omni-directional thermo-anemometers. An investigator set up a bed net with a mesh size of 220 holes per inch2 in each study household and slept under the bed net to simulate a realistic environment. The attenuation...

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

    International Nuclear Information System (INIS)

    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

  9. 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.

  10. Industrial application of the technique of removing Mo by a combination of moving packed bed and fluidized bed ion exchange

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The application of the technique of removing molybdenum by moving packed bed and fluidized bed ion-exchange in a factory was described. The data showed that the Mo removal efficiency is above 99%, and the Mo content inAFT (Ammonium Paratungstate) is controlled steadily below 18 × 10-6, in the case of treating the feed liquor containing Mo1.4 g/L. The technique is simple and convenient in operation, good reusability of resin, loss consumption of desorption rea-gent and little pollution on environment. The loss of tungsten is less than 0.5%. The technique has been proved to be aneconomical and efficient process for Mo removal.

  11. Report on the development of equipment and techniques for drilling and machining bedded salt

    International Nuclear Information System (INIS)

    Equipment and techniques are being developed in the evaluation of bedded salt as a storage media for nuclear waste. Beginning with the Conceptual Design Report for the Waste Isolation Pilot Plant and continuing with field and laboratory experiments indicate the need for a more complete understanding of bedded salt as an engineering material. This report discusses various aspects of bedded salt in its comparison to other materials, machining methods in the laboratory and equipment development to support experiments in mines

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

    International Nuclear Information System (INIS)

    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

  13. Experimental investigation of thermal conductivity coefficient and heat exchange between fluidized bed and inclined exchange surface

    OpenAIRE

    Stojanovic, B.; Janevski, J.; M. Stojiljkovic

    2009-01-01

    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 us...

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

    International Nuclear Information System (INIS)

    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

  15. Research and design of 330 MW circulating fluidized bed boiler

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Xianbin; Shi, Zhenghai; Huang, Zhong [Thermal Power Research Institute, Xi' an (China); Jiang, Minhua [China Huaneg Group, Beijing (China); Yu, Long; Zhang, Yanjun; Wang, Fengjun; Zhang, Man [Harbin Boiler CO., Ltd, Harbin (China)

    2013-07-01

    Based on research and manufacture of 210MW circulating fluidized bed (CFB) boiler, the key technologies of large CFB boiler have been Research, the plan design of 330MW CFB boiler have been performed, construction design of key components and scaling up characteristics were analysed, The 330MW CFB boiler designed demonstration project has been put into commercial operation, It is the largest capacity CFB boiler operated in china now, Operation of 330MW CFB boiler was stable and good performance has been proved.

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

    Digital Repository Service at National Institute of Oceanography (India)

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

    ) of the water particles, and kinematic viscosity (ν ): ν Au R e = (2) In order to estimate R e , the semi-excursion length of the water particles needs to be estimated properly for the solitary waves. This semi-excursion of the water particle... ⎥ ⎦ ⎤ ⎢ ⎣ ⎡ =νν (8) where, z 0 is roughness height, z is depth, ν is kinematic viscosity. It was also shown that to leading order bed shear stress, τ , can be expressed as convolution integral of the depth integrated averaged horizontal velocity, u , Eq...

  17. Global- and local-scale characterisation of bed surface structure in coarse-grained alluvial rivers

    Science.gov (United States)

    Powell, Mark; Ockelford, Annie; Nguyen, Thao; Wood, Jo; Rice, Steve; Reid, Ian; Tate, Nick

    2013-04-01

    It is widely recognised that adjustments in bed surface grain size (texture) and grain arrangement (structure) exert significant controls on the stability of coarse-grained alluvial rivers. Modifications to bed surface texture and structure occur during active sediment transport and are mediated by the process of mobile armouring which concentrates coarser-than-average particles on the surface and organises them into a variety of grain- and bedform-scale configurations. Textural aspects of surface armouring are well understood to the extent that sediment transport models can be used to predict the size distribution of armours that develop under different sediment supply regimes and shear stresses. Research has also found that the adjustment of bed surface grain size is often patchy and that the development of finer-grained and coarser-grained areas of the bed has important implications for both the rate and grain size of transported sediment. The structural aspects of stream-bed armouring, however, are less well understood, largely because of the difficulty of recognising and characterising bedforms and bed-structures that have dimensions similar to their constituent particles. Moreover, bed structure is generally parameterised using global scale descriptors of the bed surface such that information on the spatial heterogeneity of the structure is lost. The aim of this poster is to characterise the structural characteristics of water-worked river gravels, paying particular attention to quantifying the spatial heterogeneity of those characteristics using local scale descriptors. Results reported from a number of flume experiments designed to simulate the spatio-temporal evolution of bed configurations (surface texture and structure) as the system adjusts to a condition of equilibrium transport are used to evaluate the spatial variability of bed surface structure and explore its significance for modelling sediment transport rates in gravel-bed rivers. Keywords: bed

  18. Variety in dustiness and hygiene quality of peat bedding.

    Science.gov (United States)

    Airaksinen, Sanna; Heiskanen, Minna-Liisa; Heinonen-Tanski, Helvi; Laitinen, Juha; Laitinen, Sirpa; Linnainmaa, Markku; Rautiala, Sirpa

    2005-01-01

    Respiratory exposure to organic dust induces chronic pulmonary diseases both in farmers and horses. The aim of this study was to examine the variation of dustiness and hygiene quality of peat moss bedding. Materials studied were weakly decomposed sphagnum peat (A), weakly decomposed sphagnum peat warmed up in storage (> 30 degrees C) (B) and two more decomposed few-flowered sedge peats (C and D). The geometric mean of mesophilic fungi, thermotolerant fungi and thermophilic actinomycetes were determined from the material. Samples of inhalable dust and endotoxins were collected with IOM samplers and respirable dust with 10M foam samplers when the peat was rotated in a cylinder. The number of particles was detected with an optical particle counter. An LAL assay was used for analysing endotoxins from the filter samples. There were differences in the hygiene quality and dustiness between peat materials (p particles were smaller in the few-flowered peats (C-D) than in the sphagnum peats (A-B). It is concluded that there are differences in the dustiness and hygiene quality of peat bedding. PMID:16028867

  19. Plasma vasopressin and renin activity in women exposed to bed rest and +G/z/ acceleration

    Science.gov (United States)

    Keil, L. C.; Ellis, S.

    1976-01-01

    To study the effect of prolonged recumbency on plasma vasopressin and renin activity, eight women were subjected to 17 days of absolute bed rest. The tolerance to +3G vertical acceleration of the subjects was tested before and after 14 days of bed rest. From day 2 and through day 17 of bed rest, plasma arginine vasopressin (AVP) levels were reduced 33%. Plasma renin activity (PRA) increased 91% above ambulatory control values from days 10 through 15 of bed rest. When compared to precentrifuge values, exposure to vertical acceleration prior to bed rest provoked a 20-fold rise in mean plasma AVP but resulted in only a slight increase in PRA. After bed rest, acceleration increased plasma AVP 7-fold; however, the magnitude of this increase was less than the post +3G acceleration value obtained prior to bed rest. After bed rest, no significant rise was noted in PRA following +3G acceleration. This study demonstrates that prolonged bed rest leads to a significant rise in the PRA of female subjects, while exposure to positive vertical acceleration provokes a marked rise in plasma AVP.

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

    International Nuclear Information System (INIS)

    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)

  1. VERIFICATION AND COMPARISON OF FORMULAS FOR BED LOAD TRANSPORT

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Several typical formulas for bed load transport are examinedbased on field data in this paper. It is concluded that, the Einstein formula provides good estimates for the bed load transport rate while other ones predict much lower transport rates. The main reason for the under-prediction is that Dp, the effective diameter of particles, is too large as a representative diameter of the bed material for gravel streams with partially movable bed. Performance of these formulas can be significantly improved if D35 is adopted instead of Dp.

  2. 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.

  3. Comparison of Fixed and Fluidized Beds Adsorber with Economic, Engineering, and Environmental approach

    Directory of Open Access Journals (Sweden)

    SEDIGHEH ATRKAR-ROSHAN

    2015-10-01

    Full Text Available Release  Volatile  organic  compounds  (VOCs  as  environmental  and  occupational  pollutant  cause  macro perspective affect such as climate change, humans and economic consequences. Although fixed bed absorber is widely used as a controlling method because of its economically and availability, but these absorbers are facing some issue like high pressure drop, non-uniform distribution of fluid, channeling and blocking. Fixed and fluidized beds adsorbent was compared from three economic, environmental and engineering perspectives using Multi Criteria Decision Making analysis (MCDA technique. An annular fluidized bed adsorber was designed and charged with 50-100 µm (100-140 ASTM mesh activated carbon (AC particles. Effects of factors like flow rate, particle size, inlet concentration and adsorption capacity of VOCs was investigated under steady state. In the flow rate less than 0.25(Lit.min-1, inlet gas slowly passes through the void spaces of the bed’s particles. By increasing the inlet flow from 0.3(Lit/min-1, bubbles start to form in the bed and the bed pressure drop decrease. The pressure drop of 6 (g of AC in minimum fluidization velocity was 20(KN.m-2. However, the pressure drop of 10 and 20(g of AC were 150 and 420(KN.m-2 respectively. “maximin” technique used for comparison of two beds indicated that minimum score of pack bed absorber are 0.37 while the minimum score of fluidized bed adsorber are 0.5. It indicated when the adsorbent particles are smaller, fluidized bed adsorber are more suitable to use. In addition, using MCDA technique indicated that annular fluidized bed adsorber could considered as an alternative of fixed beds adsorber.

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

    Science.gov (United States)

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

    1974-01-01

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

  5. NOTE FOR EDITOR: Creativity And Teaching Competency Of Prospective B.Ed Teachers

    OpenAIRE

    GRACIOUS, F. L. Antony; ANNARAJA, P.

    2011-01-01

    The present study Creativity and Teaching Competency of prospective B.Ed teachers was probed to find the relationship between Creativity and Teaching Competency of Prospective B.Ed Teachers. Data for the study were collected using self made Teaching Competency Scale and Creativity Scale. The investigator used stratified random sampling technique for selecting the sample. The sample consists of 242 Prospective B.Ed Teachers. For analyzing data; 't' test and Pearson's product moment co-efficien...

  6. 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.

  7. Bed rest decreases mechanically induced myofiber wounding and consequent wound-mediated FGF release.

    Science.gov (United States)

    Clarke, M S; Bamman, M M; Feeback, D L

    1998-08-01

    Using a terrestrial model of spaceflight (i.e., bed rest), we investigated the amount of myofiber wounding and fibroblast growth factor (FGF) release that occurs during unloading. Myofiber wounding was determined by serum levels of the creatine kinase MM (CKMM) isoform before and after bed rest. Serum levels of both acidic FGF (aFGF) and basic FGF were also determined. A second group of subjects was treated in an identical fashion except that they underwent a resistive exercise program during bed rest. Bed rest alone caused significant (P size. In contrast, bed rest plus resistive exercise resulted in significant (P < 0.05; n = 7) increases in post-bed-rest serum levels of both CKMM and aFGF, which were paralleled by inhibition of the atrophic response. These results suggest that mechanically induced, myofiber wound-mediated FGF release may play an important role in the etiology of unloading-induced skeletal muscle atrophy. PMID:9688737

  8. Acoustic observations of near-bed sediment concentration and flux statistics above migrating sand dunes

    Science.gov (United States)

    Wilson, G. W.; Hay, A. E.

    2016-06-01

    A coherent Doppler profiler was used to measure coincident time series of velocity (u,w), sediment mass concentration (c), and sediment grain size (d), above mobile sand dunes in unidirectional flow (˜1 m/s, ˜1 m water depth). The measurements are used to extract statistical distributions of sediment concentration and flux just above the bed. Observed mass fluxes (uc,wc) were well fit by quasi-exponential distributions, at all positions along the dune profile, similar to previous observations of single-particle momenta for bed load over flat beds. Observed concentrations of moving particles were well fit by negative-binomial distributions, also similar to previous observations over flat beds. These probability distributions relate to two recent stochastic theories, previously derived and verified for uniform flow over flat beds. It is hypothesized that these theories may also be used as a local approximation in natural-scale flows with bed forms.

  9. Application of Moving Bed Biofilm Process for Biological Organics and Nutrients Removal from Municipal Wastewater

    OpenAIRE

    M. Kermani; B BINA; Haji Movahedian; Amin, M. M.; M. Nikaein

    2008-01-01

    In this study, experiments have been conducted to evaluate the organics and nutrients removal from synthetic wastewater by a laboratory scale moving bed biofilm process. For nutrients removal, moving bed biofilm process has been applied in series with anaerobic, anoxic and aerobic units in four separate reactors. Moving bed biofilm reactors were operated continuously at different loading rates of nitrogen and Phosphorus. During optimum conditions, close to complete nitrification with average ...

  10. Sea Otters Homogenize Mussel Beds and Reduce Habitat Provisioning in a Rocky Intertidal Ecosystem

    OpenAIRE

    Singh, Gerald G.; Markel, Russell W.; Martone, Rebecca G.; Salomon, Anne K.; Harley, Christopher D. G.; Chan, Kai M. A.

    2013-01-01

    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 a...

  11. Pressure distension in leg vessels as influenced by prolonged bed rest and a pressure habituation regimen.

    Science.gov (United States)

    Eiken, Ola; Mekjavic, Igor B; Kounalakis, Stylianos N; Kölegård, Roger

    2016-06-15

    Bed rest increases pressure distension in arteries, arterioles, and veins of the leg. We hypothesized that bed-rest-induced deconditioning of leg vessels is governed by the removal of the local increments in transmural pressure induced by assuming erect posture and, therefore, can be counteracted by intermittently increasing local transmural pressure during the bed rest. Ten men underwent 5 wk of horizontal bed rest. A subatmospheric pressure (-90 mmHg) was intermittently applied to one lower leg [pressure habituation (PH) leg]. Vascular pressure distension was investigated before and after the bed rest, both in the PH and control (CN) leg by increasing local distending pressure, stepwise up to +200 mmHg. Vessel diameter and blood flow were measured in the posterior tibial artery and vessel diameter in the posterior tibial vein. In the CN leg, bed rest led to 5-fold and 2.7-fold increments (P tibial artery pressure-distension and flow responses, respectively, and to a 2-fold increase in tibial vein pressure distension. In the PH leg, arterial pressure-distension and flow responses were unaffected by bed rest, whereas bed rest led to a 1.5-fold increase in venous pressure distension. It thus appears that bed-rest-induced deconditioning of leg arteries, arterioles, and veins is caused by removal of gravity-dependent local pressure loads and may be abolished or alleviated by a local pressure-habituation regimen. PMID:27079693

  12. 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

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

    OpenAIRE

    Jenssen, Petter D.; Krogstad, T.; Paruch, A.M.; Mæhlum, Trond; Adam, K.; Arias, Carlos Alberto; Heistad, A.; Jonsson, L.; Hellström, D; Brix, Hans; Yli-Halla, M.; Vråle, L.; Valve, 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 constructed wetlands with pre-treatment biofilters, but do not have wetland plants with roots submerged into the saturated filter. All saturated filters contain Filtralite®P, a light-weight expanded clay aggre...

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

    OpenAIRE

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

    2006-01-01

    Spout fluidized beds are frequently used for the production of granules or particles through granulation. The products find application in a large variety of applications, for example detergents, fertilizers, pharmaceuticals and food. Spout fluidized beds have a number of advantageous properties, such as a high mobility of the particles, which prevents undesired agglomeration and yields excellent heat transfer properties. The particle growth mechanism in a spout fluidized bed as function of p...

  15. 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.

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

    DEFF Research Database (Denmark)

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

    2015-01-01

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

  17. Some discussions on uranium mineralization in and out of the red bed (basin)

    International Nuclear Information System (INIS)

    Economic uranium mineralization exists in and out of the red bed (basin). Uranium mineralization out of the red bed includes various types, such as the unconformity-related type, grainite type, carbonate-silicoeous-pelitic type, palaeokarst type, infiltration type and sandstone type, the formatoinal process and distribution of which are closely related to the red bed (basin). It is by no means the protective layer of the unconformity-related uranium mineralization. The metallogenetic model and prospecting orientation for uranium mineralization out of the red bed are also summarized

  18. 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...... particle surfaces by accumulation of liquid droplets preferentially in areas sheltered from turbulence and mechanical interaction. The composition of the film suggests melting of locally accumulated dust or aerosol mixture of ash particles and mullite. The film only locally enlarged bed particles. Large...... straw ash particles appear to have mostly been passively incorporated into the adhesive melt without melting or reaction....

  19. Fluidized-bed and fixed-bed reactor testing of methane chemical looping combustion with MgO-promoted hematite

    International Nuclear Information System (INIS)

    Highlights: • Mg-promoted hematite showed better performance than hematite for methane CLC. • Stable reaction performance was observed during cyclic CH4 CLC fluidized bed tests. • Attrition resistance was better than that with standard FCC catalysts. • 5 wt% MgO increased both the oxygen capacity and reaction rates for CH4 CLC. • Possible mechanisms for the CH4 CLC OC performance enhancement are presented. - Abstract: In this study MgO-promoted Fe2O3 hematite oxygen carriers were synthesized from various Mg sources and evaluated for methane chemical looping combustion. Particles suitable for fluidized bed flow reactor studies were prepared in the lab. Cyclic CLC tests conducted in the fluidized bed with MgO promoted hematite showed better performance than that with hematite. Attrition resistance of laboratory prepared MgO promoted hematite was excellent. Reactivity and stability of the oxygen carrier materials were also tested in the thermogravimetric analyzer and bench-scale reactors. Scanning electron microscopy and energy-dispersive X-ray spectroscopy, and X-ray diffraction were used to study the morphology and elemental compositions present in the hematite and promoted hematite oxygen carriers prior to and following the multi-cycle chemical looping reaction. The incorporation of 5 wt% MgO led to an increased reaction rate and an increase in oxygen utilized as compared to the pure hematite oxygen carrier. Possible reasons for the promotion effect by MgO were evaluated. These studies reveal that the best performing oxygen carrier was the 5 wt% MgO/Fe2O3 which exhibited no observed degradation in the kinetics and conversion performance in the methane step over 15 reduction and oxidation cycles. The Mg promoted oxygen carrier also showed reduced coke formation as compared to the pure hematite carrier

  20. Study of Solids and Gas Distribution in Spouted Bed Operated In Stable and Unstable Conditions

    Directory of Open Access Journals (Sweden)

    Alwan, G. M.,

    2014-02-01

    Full Text Available A spouted bed is a special case of fluidization. It is an effective means of contacting gas with coarse solid particles. Spouted beds should be designed and operated to overcome performance instability and improves the uniform distribution of particles. Steady-state measurements were carried out in the 0.152 m ID cylindrical spouted bed made of Plexiglas that used 60° conical shape spout-air bed. The evaluation of solid and gas holdup in the two regions of spouted bed at stable and an unstable condition was performed using optical probe. The comparison of the radial profiles at the two conditions showed that the variation was in the spout region. The annulus region had similar profiles in both the condition as it acts as a loose packed bed, moving slowly downward. Stable bed was obtained at low gas velocity of 0.74 m/s and instability of spouting was observed at high gas velocity of 1.4 m/s. The beads can fluidize homogenously at stable conditions, while pulsation of the bed was appeared at unstable spout. Different flow regimes and characteristics can be obtained with minor variations in geometry or operating conditions.

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

    International Nuclear Information System (INIS)

    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

  2. Fluid and electrolyte shifts during bed rest with isometric and isotonic exercise

    Science.gov (United States)

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

    1977-01-01

    It is difficult to separate the effects of reduction in hydrostatic pressure from that of reduced energy expenditure when investigating the confinement deconditioning problem. Experiments were conducted on seven healthy young men aged 19-21 yr with the purpose of separating these two factors by using isotonic physical exercise during bed rest to provide a daily energy expenditure greater than normal ambulatory levels. Fluid and electrolyte shifts were measured during three two-week bed rest periods, each of which being separated by a three-week ambulatory recovery period. During two of the three bed rest periods they performed isometric and isotonic exercises to compare their effects on fluid and electrolyte shifts during bed rest. It is shown that during bed rest, preservation of the extracellular volume takes precedence over maintenance of the plasma volume and that this mechanism is independent of the effects of isometric or isotonic exercise.

  3. Enhanced stability of hillslopes and channel beds to mass failure

    Science.gov (United States)

    Prancevic, Jeff; Lamb, Michael; Palucis, Marisa; Venditti, Jeremy

    2016-04-01

    The stability of inclined, unconsolidated sediments subjected to groundwater flow on hillslopes and steep channel beds is important for both landscape evolution and natural hazards. Force-balance models have been used for seven decades to predict the stability of slopes, but they generally underpredict the degree of saturation required to destabilize the sediment. Researchers often appeal to heightened stabilizing forces from root and mineral cohesion, and friction acting on the margins of the failure to explain this underprediction. Surprisingly, infinite-slope stability models in their simplest form have never been tested under controlled laboratory conditions. To address this gap in data, we perform a set of controlled laboratory experiments with slope-parallel seepage in the simplest possible configuration. We performed 47 experiments in a 5 m laboratory flume with 4 grain sizes (D50 = 0.7, 2, 5, and 15 mm) and a wide range in bed angles (20° to 43°), spanning both Darcian and turbulent subsurface flow regimes. Our experiments show that granular slopes were more stable than predicted by simple force balance models in experiments that lack root or mineral cohesion. Despite the smooth plastic walls and the long aspect ratio of our flume, we calculate wall and toe friction to be important. Including these additional resistance terms in the model reduces the model misfit with our experimental results. However, there is considerable remaining misfit (up to 50% underestimation of the saturation level required for failure). We investigate two explanations of this heightened stability: 1) standard frictional resistance terms are underestimated, and 2) seepage stresses are overestimated. Both explanations require that we modify the models used to predict slope stability.

  4. The JET ICRF antennae systems: Description and test bed results

    International Nuclear Information System (INIS)

    The main design features and test results of the prototype antennae systems for ICRF heating of JET are described. These have integral side protection, thick tilted screens, monopole or quadrupole central conductors, and are each fed by two co-axial lines of diameter varying from 100 to 230mm. The vacuum window is of a double, vacuum brazed alumina construction. The main components have been tested on the JET RF Test Bed at Fontenay-aux-Roses to maximum voltage (50kV) and current (1500 Amps). Apart from a narrow forbidden band at a low voltage due to the onset of multipactor arcs, these systems have largely met the required specifications

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

    Science.gov (United States)

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

    1994-01-01

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

  6. Steam gasification of various feedstocks at a dual fluidised bed gasifier: Impacts of operation conditions and bed materials

    Energy Technology Data Exchange (ETDEWEB)

    Pfeifer, Christoph; Koppatz, Stefan; Hofbauer, Hermann [Vienna University of Technology, Institute of Chemical Engineering, Vienna (Austria)

    2011-03-15

    Gasification of biomass is an attractive technology for combined heat and power production as well as for synthesis processes such as production of liquid and gaseous biofuels. Dual fluidised bed (DFB) technology offers the advantage of a nearly nitrogen-free product gas mainly consisting of H{sub 2}, CO, CO{sub 2} and CH{sub 4}. The DFB steam gasification process has been developed at Vienna University of Technology over the last 15 years using cold flow models, laboratory units, mathematical modelling and simulation. The main findings of the experimental work at a 100-kW pilot scale unit are presented. Different fuels (wood pellets, wood chips, lignite, coal, etc.) and different bed materials (natural minerals such as olivine, limestones, calcites, etc. as well as modified olivines) have been tested and the influence on tar content as well as gas composition was measured and compared among the different components. Moreover, the influence of operating parameters such as fuel moisture content, steam/fuel ratio and gasification temperature on the product gas has been investigated. DFB steam gasification of solid biomass coupled with CO{sub 2} capture, the so-called absorption enhanced reforming (AER) process, is highlighted. The experiments in pilot scale led to commercial realisation of this technology in demonstration scale. Summarising, the DFB system offers excellent fuel flexibility to be used in advanced power cycles as well as in polygeneration applications. (orig.)

  7. Sediment concentration profiles in bed-near-bed layers under unsteady flow and sediment conditions : a CT-Scanned flume investigation

    Science.gov (United States)

    Leclair, Suzanne; Long, Bernard

    2015-04-01

    This paper presents a case study from a CT-scan flume experiment on the variation in sediment transport (concentration) under transitional, initially high-regime (but decreasing), sub-critical flow with bed erosion or no net aggradation. The objective is to better understand sediment transport during unsteady flows such as during a wining flood. In particular, the effect of mud-aggregate transport on sediment concentration in the bed-near-bed continuum was addressed. CT-scans were taken during sediment transport, with plane beds or dunes being the bed state. The density material (water and/or sediment) in over 105 volumes (voxels, each approximately equivalent to a grain of 0.8 mm) were analysed. Computed Tomography technology provides high-resolution results, both in time and space, and allows recognition of subtle changes in the shape of relative sediment concentration profile with bed states. The migration and attrition of mud aggregates in this experiment increased the mean volume fraction sediment concentration in the bed-near-bed layer (lower 5% of the flow) by a factor of about 2, from an inital value of 0.12 up to 0.25, and back to 0.13 when the supply ended. Also, the presence of mud-aggregates in the preserved deposits (transported as bedload) increases bed porosity. This case study demonstrates the great potential of Computed Tomography in process-oriented, experimental sedimentology. The community would benefit from more collaborative research using this technology, including data sharing as suggested by initiatives such as the Sediment Experimentalists Network (http://workspace.earthcube.org/sen)

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

    International Nuclear Information System (INIS)

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

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

    OpenAIRE

    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. Th...

  10. 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. PMID:1757634

  11. Catalytic Pyrolysis of Oak via Pyroprobe and Bench Scale, Packed Bed Pyrolysis Reactors

    Science.gov (United States)

    The pyrolytic conversion of oak sawdust at 500°C in flowing He over eight proprietary catalysts is described and compared to the control bed material, quartz sand. The reactions were conducted and compared in two reactors, an analytical, ug-scale pyroprobe reactor and a bench, g-scale packed bed re...

  12. 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.; Jørgensen, BB

    1996-01-01

    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 and...

  13. 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.…

  14. Theory and technique of permeability enhancement and coal mine gas extraction by fracture network stimulation of surrounding beds and coal beds

    Directory of Open Access Journals (Sweden)

    Ma Geng

    2014-12-01

    Full Text Available The existing reservoir stimulating technologies are only applicable to hard coal but helpless for soft coal, which is one of the main factors hindering the CBM industrialization in China. Therefore, it is urgent to develop a universal stimulating technology which can increase the permeability in various coal reservoirs. Theoretical analysis and field tests were used to systematically analyze the mechanical mechanisms causing the formation of various levels and types of fractures, such as radial tensile fractures, peripheral tensile fractures, and shear fractures in hydraulic fracturing, and reveal the mechanism of permeability enhancement by fracture network stimulating in surrounding beds and coal reservoirs. The results show that multi-staged perforation fracturing of horizontal wells, hydraulic-jet staged fracturing, four-variation hydraulic fracturing and some auxiliary measures are effective technical approaches to fracture network stimulation, especially the four-variation hydraulic fracturing can stimulate the fracture network in vertical and cluster wells. It is concluded that the fracture network stimulating technology for surrounding beds has significant advantages, such as safe drilling operation, strong stimulation effect, strong adaptability to stress-sensitive and velocity-sensitive beds, and is suitable for coal reservoirs of any structure. Except for the limitation in extremely water-sensitive and high water-yield surrounding beds, the technology can be universally used in all other beds. The successful industrial tests in surface coal bed methane and underground coal mines gas extraction prove that the theory and technical system of fracture network stimulating in surrounding beds and coal reservoirs, as a universally applicable measure, will play a role in the CBM development in China.

  15. Spectral Characteristics of Common Reed Beds: Studies on Spatial and Temporal Variability

    Directory of Open Access Journals (Sweden)

    Jyrki Tuominen

    2016-02-01

    Full Text Available Reed beds are the second largest producer of biomass in Olkiluoto Island. Quantitative information on the extent and amount of reed stands is an integral part of the biosphere assessment related to long-term safety analysis of nuclear fuel repository site currently under construction. The major challenge in reed bed mapping is discrimination between reed and other green vegetation. Spectral field measurements were used to study the temporal and spatial variability of spectral characteristics of reed beds. Feasibility of discriminating reed beds from other vegetation based on hyperspectral measurements was studied as well. Results indicate that there is large temporal variation of reed bed spectra and the optimal time for data acquisition differs for old and new reed bed types. Comparing spectral characteristics of the reed bed and meadow classes in a local neighborhood indicated that the classes have high within-class spectral variability and similar mean spectra, however, 10 out of 11 targets had lower angle to the mean spectrum of the corresponding class than that of the other class when Spectral Angle Mapper (SAM was used. Comparing the spectral characteristics of reed beds at four test sites within the Olkiluoto Island indicated that while some of the sites had similar spectra, the difference between others was remarkable. This is partly explained by different density and height of dead and live reed stems at the four sites.

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

    Directory of Open Access Journals (Sweden)

    S. Heinrich

    2005-06-01

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

  17. Seston Dynamics and Food Availability on Mussel and Cockle Beds

    Science.gov (United States)

    Smaal, A. C.; Haas, H. A.

    1997-08-01

    To provide a better understanding of seston dynamics in relation to food supply to the benthos, a series of 13-h tidal cycle sampling programmes was executed in the Oosterschelde estuary (The Netherlands). Samples were taken near the surface and near the bottom on two subtidal mussel cultivation plots and on two intertidal cockle beds. Long-term annual variablity of seston concentrations was lower than coefficients of variance of the short-term tidal cycle seston data at the intertidal stations, and higher than at the subtidal stations. Near-bottom relative to surface concentrations were highest for suspended particulate matter (SPM), followed by particulate organic carbon (POC), and chlorophyll. There was no food depletion near the bottom but food quality was lower, presumably due to re-suspension of sediment, including low-quality biodeposits. Chlorophyll concentrations were lower in ebb than flood water at all stations, which was ascribed to feeding activity of the bivalves. At the subtidal stations, SPM and POC concentrations were also lower during low water, owing to sedimentation. There was a positive correlation at the intertidal stations of seston quantity with wind speed and wave action. At a wave length exceeding twice the water depth, re-suspension of low quality bottom material was observed and seston quality decreased. It was concluded that food availability for benthic suspension feeders was lower than suggested by routine monitoring data. At the intertidal stations, food quality was further reduced during periods of increased wind velocities and wave action. The low near-bottom food quality can partly be considered as an effect of the feeding activity of the benthic suspension feeders.

  18. Approximate relationship of coal bed methane and magnetic characteristics of rock via magnetic susceptibility logging

    International Nuclear Information System (INIS)

    In coal bed methane (CBM) exploration, how to improve the accuracy for locating and evaluating the CBM deposits is still a problem due to the rarity of occurrence of CBM. Combined with the distribution of the CBM content in the Huainan coalfield, the approximate relationship between the occurrence of CBM and the magnetic properties of the coal bed and adjacent mudstone have been widely discussed by magnetic logging. Experimental results show that magnetic susceptibility of the coal bed and adjacent mudstone would clearly increase with the CBM content in a coal bed. According to the results of the experiment, the prediction of the CBM content has been accomplished for different coal beds, and the results are consistent with the distribution of the CBM content throughout the whole coalfield. Preliminary data analysis reveals that there is indeed a correlation between the changes of magnetic rock characteristics and the occurrence of the CBM, and this finding may shed some light on the evaluation of CBM

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

    International Nuclear Information System (INIS)

    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

  20. Experiment and numerical simulation of water surface response to rise and depression of the sea bed

    International Nuclear Information System (INIS)

    Water surface response to rise and depression of the sea bed was investigated by a hydraulic experiment and a numerical model development based on a fully nonlinear boundary element method. First, it was found that initial water surface behavior is fairly coincident between the experimental and numerical results under the initial conditions of up-surge and down-surge. Secondly, by the experimental and the numerical results it was made clear that larger deformation speed of the sea bed, smaller sea bed deformation and smaller water depth of the sea movement cause larger response efficiency of water surface. (author)

  1. Measurement of wall and interfacial friction factors for counter-current flow in porous bed

    International Nuclear Information System (INIS)

    In the course of a severe accident, a debris bed is formed from once molten and fragmented fuel elements as observed in the Three-Mile Island unit-2 accident. The debris bed must be cooled to avoid further degradation of the core, since the degraded core releases decay heat. Even if the degraded core is in water, it cannot be judged that the degraded core would be coolable, since the degraded core may be melted again if dryout occurs. It is thus necessary to evaluate the dryout heat flux for the judgment of the coolability of the debris bed during the severe accident. Dryout phenomena in the debris bed is dominated by two-phase flow behavior in the debris bed. Especially, it is strongly affected by counter-current flow limitation (CCFL) in the debris bed. Therefore, it is important to know the flow characteristics of CCFL in the debris bed. If one hopes to analyze counter-current flow in the debris bed by using the same method as usual two-fluid model, it is necessary to know the interfacial and the wall friction factors. However, it is not clear that the correlations for interfacial and wall friction factor for a pipe can be used for counter-current flow in the debris beds. In order to determine the interfacial and wall friction factors, it is necessary to obtain wall and interfacial shear stresses. The wall and the interfacial shear stresses depend on the void fraction and differential pressure. However, at present, there is no available data for local void fraction and local pressure distribution in the debris bed at CCFL, since it is very difficult to measure the flow characteristics in the complex geometry such as the debris bed. In the present study, air-water CCFL experiment was conducted with a debris bed simulated with glass particles to measure the local void fraction and the local pressure distributions simultaneously as well as the flow rates for gas and liquid. The present experimental research succeed to measure the local void fraction under CCFL in

  2. 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

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

    NARCIS (Netherlands)

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

    2010-01-01

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

  4. 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 o

  5. Mangroves and seagrass beds as diurnal feeding habitats for juvenile Haemulon flavolineatum

    NARCIS (Netherlands)

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

    2007-01-01

    Caribbean seagrass beds supposedly 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. Therefore, we studied daytime behavior of large juvenile (

  6. 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.

    2006-01-01

    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 opportunist

  7. 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)

  8. Comparison of fixed and fluidized activated carbon beds for removal of organic vapors

    Energy Technology Data Exchange (ETDEWEB)

    Agranovski, I.E. [Faculty of Environmental Sciences, Griffith University, Brisbane (Australia); Moustafa, S.; Braddock, R.D. [School of Environmental Engineering, Griffith University, Nathan (Australia)

    2004-07-01

    Activated carbons are commonly used for removal of organic vapors from exhaust air streams. Two configurations, including fixed and fluidized carbon beds are usually employed in industry to meet various requirements of the industrial process which is being used. This paper investigates the performance of such configurations and provides a comparative analysis. It was found that for thin carbon layers, the fixed bed performs more efficiently with the difference exceeding 15 % for the layers with the thickness less than 15 mm. This difference is decreasing with increase of the layer thickness and becomes less than 5 % for the beds thicker than 100 mm. Considering various advantages of the fluidized beds over fixed beds, including lower resistance to the gas flow, excellent gas distribution and minimal possibility of clogging in case of existence of alien particles in the gas, they are recommended for use with the minimal thickness of the layer to be larger than 100 mm. (Abstract Copyright [2004], Wiley Periodicals, Inc.)

  9. Sequential experimental design for estimation and analysis of thermal parameters in a fixed bed

    International Nuclear Information System (INIS)

    The analysis of the effective radial thermal conductivity and the film heat transfer coefficient were carried out in a fixed bed. The temperature profiles were described by two-dimensional pseudo-homogeneous model. The thermal parameters were estimated using a sequential experimental design technique. The minimum volume criterion was used to design the next point for temperature measurement m the bed. The utilization of T = T0 (constant) as the boundary condition at the bed inlet resulted in an axial variation of thermal parameters, which was the factor responsible for the inadequacy of the model in fitting experimental data of different bed heights simultaneously. Using T=T(r) as the boundary condition makes the thermal parameters independent of the axial position and the model statiscally adequate to describe the axial and radial temperature profiles throughout the bed. (author)

  10. Multiscale simulations of self-organization phenomena in the formation and coolability of corium debris bed

    International Nuclear Information System (INIS)

    DECOSIM code is applied to the simulation of ex-vessel debris bed cooling in a water pool, taking into account dynamic growth of debris bed due to gradual corium melt release. It is shown that, for deep enough water pool and long enough melt discharge time (dripping mode), melt particle trajectories are distorted substantially by the natural convection flows developing in the water pool. Therefore, the shape of the debris bed is affected by the flow which, in turn, depends on the spatial distribution of heat and vapor sources in the debris bed. Such feedbacks create effects of 'self-organization' in the debris bed formation and coolability which are demonstrated for various scenarios. (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. 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)

    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)

  13. Implementation and full scale test of sand bed filter

    International Nuclear Information System (INIS)

    All French PWR's operating plants are now equipped with a containment postaccident decompression filtration system using a sand bed filter. The system also possesses a real time gamma spectrometry radioactivity monitor. First, the paper covers: the design and sizing requirements of the system resulting from a R and D program (PITEAS) carried out at the Cadarache Nuclear Studies Center jointly by Electricite de France and the French Atomic Energy Commission; the detailed description of the radioactivity monitor which would display the activity concentration for the main radioactive elements (iodine, caesium, etc) with a large range; the principles and the results of full scale tests carried out on a test loop (FUCHIA) with a representative geometry of the French plants. The aim was to know the operating limits of the system in two different kinds of tests; filtration efficiency tests with aerosols generated by means of plasma torches; thermohydraulic and thermic behaviour tests with residual power simulation by means of electrical heaters. The FUCHIA tests have definitively qualified the system showing global efficiencies of about 200 for the aerosols. In its present state the system is able to mitigate most cases of severe accident scenarios. Nevertheless, Electricite de France has decided to improve the ability of the system and to reduce the dose rate on site in still severer postaccident conditions. Therefore, the paper also covers: the design of the complementary radiological shieldings, for the 900 MW series and the first 1300 MW series these consist of glass fiber thermosetting resin containers filled with water at the right time, for all other series they consist of a concrete slab; the principle of the sand bed filter heat removal, after use the filter tank can be water sprinkled or cooled by a sufficient fresh air flow; the design of the hydrogen risk protection by preheating, this consists of heated air flow blown with a fixed fan and an electric heater

  14. 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)

  15. Moving bed biofilm reactor technology: process applications, design, and performance.

    Science.gov (United States)

    McQuarrie, James P; Boltz, Joshua P

    2011-06-01

    The moving bed biofilm reactor (MBBR) can operate as a 2- (anoxic) or 3-(aerobic) phase system with buoyant free-moving plastic biofilm carriers. These systems can be used for municipal and industrial wastewater treatment, aquaculture, potable water denitrification, and, in roughing, secondary, tertiary, and sidestream applications. The system includes a submerged biofilm reactor and liquid-solids separation unit. The MBBR process benefits include the following: (1) capacity to meet treatment objectives similar to activated sludge systems with respect to carbon-oxidation and nitrogen removal, but requires a smaller tank volume than a clarifier-coupled activated sludge system; (2) biomass retention is clarifier-independent and solids loading to the liquid-solids separation unit is reduced significantly when compared with activated sludge systems; (3) the MBBR is a continuous-flow process that does not require a special operational cycle for biofilm thickness, L(F), control (e.g., biologically active filter backwashing); and (4) liquid-solids separation can be achieved with a variety of processes, including conventional and compact high-rate processes. Information related to system design is fragmented and poorly documented. This paper seeks to address this issue by summarizing state-of-the art MBBR design procedures and providing the reader with an overview of some commercially available systems and their components. PMID:21751715

  16. Comparison of bed form variance spectra within a meander bend during flood and average discharge.

    Science.gov (United States)

    Levey, R.A.; Kjerfve, B.; Getzen, R.T.

    1980-01-01

    Time series analysis of streambed elevation in a meander bend along the Congaree River was used to determine the changes in bed form population succeeding a 16-year flood event. Variance spectra computed for a 595m longitudinal profile indicate that: a) the bed form variance for the flood record is significantly greater for all wavelengths from 5 to 30m; b) no well-demarcated bed form classes were present during the survey times, pointing to the possible existence of a continuum of bed form sizes rather than well-defined classes; and c) bed forms produced by the flood discharge were rapidly altered as the stage returned toward average level. -from Authors

  17. 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.

  18. Bubbles trapped in a fluidized bed: Trajectories and contact area

    Science.gov (United States)

    Poryles, Raphaël; Vidal, Valérie; Varas, Germán

    2016-03-01

    This work investigates the dynamics of bubbles in a confined, immersed granular layer submitted to an ascending gas flow. In the stationary regime, a central fluidized zone of parabolic shape is observed, and the bubbles follow different dynamics: either the bubbles are initially formed outside the fluidized zone and do not exhibit any significant motion over the experimental time or they are located inside the fluidized bed, where they are entrained downwards and are, finally, captured by the central air channel. The dependence of the air volume trapped inside the fluidized zone, the bubble size, and the three-phase contact area on the gas injection flow rate and grain diameter are quantified. We find that the volume fraction of air trapped inside the fluidized region is roughly constant and of the order of 2%-3% when the gas flow rate and the grain size are varied. Contrary to intuition, the gas-liquid-solid contact area, normalized by the air injected into the system, decreases when the flow rate is increased, which may have significant importance in industrial applications.

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

    International Nuclear Information System (INIS)

    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 (CCl4), 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 CO2 is not released to the environment

  20. Sympathetic discharge and vascular resistance after bed rest

    Science.gov (United States)

    Shoemaker, J. K.; Hogeman, C. S.; Leuenberger, U. A.; Herr, M. D.; Gray, K.; Silber, D. H.; Sinoway, L. I.

    1998-01-01

    The effect of -6 degrees head-down-tilt bed rest (HDBR) for 14 days on supine sympathetic discharge and cardiovascular hemodynamics at rest was assessed. Mean arterial pressure, heart rate (n = 25), muscle sympathetic nerve activity (MSNA; n = 16) burst frequency, and forearm blood flow (n = 14) were measured, and forearm vascular resistance (FVR) was calculated. Stroke distance, our index of stroke volume, was derived from measurements of aortic mean blood velocity (Doppler) and R-R interval (n = 7). With these data, an index of total peripheral resistance was determined. Heart rate at rest was greater in the post (71 +/- 2 beats/min)- compared with the pre-HDBR test (66 +/- 2 beats/min; P pressure was unchanged. Aortic stroke distance during post-HDBR (15.5 +/- 1.1 cm/beat) was reduced from pre-HDBR levels (20.0 +/- 1.5 cm/beat) (P forearm blood flow, FVR, or total peripheral resistance. Thus reductions in MSNA with HDBR were not associated with a decrease in FVR.

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

    International Nuclear Information System (INIS)

    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 C5+ 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 400degC in the dual-bed system is higher than that of the single-bed system

  2. Mechanics Principle and Engineering Application of Split Layer and Bed Separation of Mining Overburden

    Institute of Scientific and Technical Information of China (English)

    YU Guang-ming; ZHANG Chun-hui; SU Zhong-jie; FAN Xue-li; PAN Yong-zhan; LIU Fu-shun

    2005-01-01

    To control land surface subsidence caused the underground mineral exploitation and the catastrophic phenomena such as serious damage of buildings, waterbodies, cultivated lands, railways, bridges caused by land subsidence, bed separation grouting technology of overburden is put forward. To provide theoretical support for the technology, the characteristics and the mechanics mechanism of mining overburden from layer-split to formation of bed separation are studied. On the basis of elastic sheet board theory, calculation formula of rock sheet deflection is presented, and the mechanics criteria of the separation formation and the calculation formula of bed separation volume are set up. Finally, the applications and technics of bed separation grout technology of mining overburden to control land subsidence in china are introduced.

  3. Coal resources of selected coal beds and zones in the northern and central Appalachian Basin

    Energy Technology Data Exchange (ETDEWEB)

    Leslie Ruppert; Susan Tewalt; Linda Bragg

    2002-02-01

    The U.S. Geological Survey (USGS) is completing a National Coal Resource Assessment of five coal-producing regions of the United States, including the Appalachian Basin. The USGS, in cooperation with the State geological surveys of Kentucky, Maryland, Ohio, Pennsylvania, Virginia, and West Virginia, has completed a digital coal resource assessment of five of the top-producing coal beds and coal zones in the northern and central Appalachian Basin coal regions -- the Pittsburgh coal bed, the Upper Freeport coal bed, the Fire Clay and Pond Creek coal zones, and the Pocahontas No. 3 coal bed. Of the 93 billion short tons of original coal in these units, about 66 billion short tons remain. 2 refs., 5 figs., 2 tabs.

  4. Stress Tolerance of Bed Bugs: A Review of Factors That Cause Trauma to Cimex lectularius and C. Hemipterus

    OpenAIRE

    Benoit, Joshua B.

    2011-01-01

    Recent emergence of bed bugs (Cimex spp.) has prompted a significant expansion of research devoted to this pest. The ability to survive and recover from stress has significant implications on the distribution and survival of insects, and bed bugs are no exception. Research on bed bug stress tolerance has shown considerable progress and necessitates a review on this topic. Bed bugs have an extraordinary ability to resist dehydration between bloodmeals, and this represents a critical factor all...

  5. Storm Bed Imprinting on the Northern California Shelf: Interaction of Fluvial and Marine Processes.

    Science.gov (United States)

    Swift, D. J.; Fan, S.; Niedoroda, A. W.; Reed, C.; Borgeld, J. C.; Crockett, J. S.

    2001-05-01

    Seismic records and cores from ONR's STRATAFORM program indicate that the Holocene deposits on the northern California shelf consist of a succession of back-stepping, storm-generated event beds, deposited as sediment undergoes cross-shelf dispersal from intermittently flooding river mouths. The beds are modified to varying degrees by secondary processes (gravity transport, bioturbation). Box core observations show that there is "mud line" on the shelf surface at approximately the 45 m isobath. Long cores show that within the 3-dimensional sediment body, nearshore sand beds intertongue with offshore mud beds beneath this line. However, numerical simulations suggest a more complex relationship. Instead of intertonguing, most event beds begin as sand beds in the nearshore sand deposit, pass through an interbedded zone, and enter the offshore mud deposit as mud beds. Event stratification is difficult to discern both seaward and landward of the transitional zone, mainly because the Cutoff Percentage has been exceeded in these areas (percent thickness of an upward-fining bed which must be preserved to observe grain size contrast). There are thus three facies bodies present, an Amalgamated Sand Facies on the inner shelf (sand beds on sand beds), an Interbedded Sand and Mud Facies on the central shelf, and an offshore Laminated or Bioturbated Mud Facies. Several other parameters are useful for defining these facies. The degree of condensation (extent to which each bed has cannibalized its predecessor) can be measured by the Reworking Ratio (ratio of mean annual resuspension depth to deposition per event). This value decreases seaward across the shelf to a minimum in the Interbedded Facies in response to decreasing wave energy flux into the sea floor. It then increases seaward across the outer shelf, as the decrease in available sediment becomes more important. The standard deviation of bed thickness is (in part) a measure of variation in storm intensity, and is a

  6. Geochemical "fingerprints" for Olduvai Gorge Bed II tuffs and implications for the Oldowan-Acheulean transition

    Science.gov (United States)

    McHenry, Lindsay J.; Njau, Jackson K.; de la Torre, Ignacio; Pante, Michael C.

    2016-01-01

    Bed II is a critical part of early Pleistocene Olduvai Gorge, Tanzania. Its deposits include transitions from humid to more arid conditions (with associated faunal changes), from Homo habilis to erectus, and from Oldowan to Acheulean technology. Bed II (~ 1.8-1.2 Ma) is stratigraphically and environmentally complex, with facies changes, faulting, and unconformities, making site-to-site correlation over the ~ 20 km of exposure difficult. Bed II tuffs are thinner, less evenly preserved, and more reworked than those of Bed I. Five marker tuffs (Tuffs IIA-IID, Bird Print Tuff (BPT)), plus local tephra, were collected from multiple sites and characterized using stratigraphic position, mineral assemblage, and electron probe microanalysis of phenocryst (feldspar, hornblende, augite, titanomagnetite) and glass (where available) composition. Lowermost Bed II tuffs are dominantly nephelinitic, Middle Bed II tuffs (BPT, Tuff IIC) have basaltic components, and upper Bed II Tuff IID is trachytic. The BPT and Tuff IID are identified widely using phenocryst compositions (high-Ca plagioclase and high-Ti hornblende, respectively), though IID was originally (Hay, 1976) misidentified as Tuff IIC at Loc 91 (SHK Annexe) in the Side Gorge. This work helps establish a high-resolution basin-wide paleolandscape context for the Oldowan-Acheulean transition and helps link hominin, faunal and archaeological records.

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

    Directory of Open Access Journals (Sweden)

    von Seidlein Lorenz

    2012-06-01

    Full Text Available Abstract Background/Methods Qualitative studies suggest that bed nets affect the thermal comfort of users. To understand and reduce this discomfort the effect of bed nets on temperature, humidity, and airflow was measured in rural homes in Asia and Africa, as well as in an experimental wind tunnel. Two investigators with architectural training selected 60 houses in The Gambia, Tanzania, Philippines, and Thailand. Data-loggers were used to measure indoor temperatures in hourly intervals over a 12 months period. In a subgroup of 20 houses airflow, temperature and humidity were measured at five-minute intervals for one night from 21.00 to 6.00 hrs inside and outside of bed nets using sensors and omni-directional thermo-anemometers. An investigator set up a bed net with a mesh size of 220 holes per inch2 in each study household and slept under the bed net to simulate a realistic environment. The attenuation of airflow caused by bed nets of different mesh sizes was also measured in an experimental wind tunnel. Results The highest indoor temperatures (49.0 C were measured in The Gambia. During the hottest months of the year the mean temperature at night (9 pm was between 33.1 C (The Gambia and 26.2 C (Thailand. The bed net attenuated the airflow from a minimum of 27% (Philippines to a maximum of 71% (The Gambia. Overall the bed nets reduced airflow compared to un-attenuated airflow from 9 to 4 cm sec-1 or 52% (p -2 reduced airflow by 55% (mean; range 51 - 73%. A denser net (200 holes inch-2 attenuated airflow by 59% (mean; range 56 - 74%. Discussion Despite concerted efforts to increase the uptake of this intervention in many areas uptake remains poor. Bed nets reduce airflow, but have no influence on temperature and humidity. The discomfort associated with bed nets is likely to be most intolerable during the hottest and most humid period of the year, which frequently coincides with the peak of malaria vector densities and the force

  8. Connection Between Liquid Distribution and Gas-Liquid Mass Transfer in Monolithic Bed

    Institute of Scientific and Technical Information of China (English)

    许闽; 刘辉; 李成岳; 周媛; 季生福

    2011-01-01

    With a particular focus on the connection between liquid flow distribution and gas-liquid mass transfer in monolithic beds in the Taylor flow regime, hydrodynamic and gas-liquid mass transfer experiments were carriedout in a column with a monolithic bed of cell density of 50 cpsi with trio different distributors (nozzle and packed bed distributors). Liquid saturation in individual channels was measured by using self-made micro-conductivity probes. A mal-distribution factor was used to evaluate uniform degree of phase distribution in monoliths. Overall bed pressure drop and mass transfer coefficients were measured. For liquid flow distribution and gas-liquid masstransfer, it is found that the superficial liquid velocity is a crucial factor and the packed bed distributor is better than the nozzle distributor. A semi-theoretical analysis using single channel models shows that the packed bed distributor always yields shorter and uniformly distributed liquid slugs compared to the nozzle distributor, which in turn ensures a better mass transfer performance. A bed scale mass transfer model is proposed by employing the single channel models in individual channels and incorporating effects of non-uniform liquid distribution along the bedcross-section. The model predicts the overall gas-liquid mass transfer coefficient wig a relative error within +30%.

  9. Numerical simulation of gas concentration and dioxin formation for MSW combustion in a fixed bed.

    Science.gov (United States)

    Sun, Rui; Ismail, Tamer M; Ren, Xiaohan; Abd El-Salam, M

    2015-07-01

    A numerical model was employed to simulate the combustion process in a fixed porous bed of municipal solid waste (MSW). Mass, momentum, energy and species conservation equations of the waste bed were set up to describe the incineration process. The rate of moisture evaporation, volatile matter devolatilization, char combustion, NOx production, and reduction and dioxin formation were calculated and established according to the local thermal conditions and waste property characteristics. Changes in the bed volume during incineration were calculated according to the reaction rate of the process. The simulation results were compared with experimental data, which shows that the incineration process of waste in the fixed bed was reasonably simulated. The simulation results of weight loss and solid temperature in the bed agree with the experimental data, which shows that the waste combustion rate is nearly constant in the middle of the incineration process, and that moisture evaporation takes up most of the time for the overall incineration experiment. The emission of gas species from the bed surface is also agreeably simulated, with O2, CO2, and CO concentrations in flue gas agreeing with the experimental data. The simulation results benefit the understanding of the combustion process in the waste bed as well as the design of incinerator grates. PMID:25897505

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

    Energy Technology Data Exchange (ETDEWEB)

    1978-09-01

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

  11. The Effects of Agitated Beds Homogenization on Stirrer Geometry and Bed Depth via DEM

    Czech Academy of Sciences Publication Activity Database

    Kohout, M.; Trávníčková, Tereza; Havlica, Jaromír

    Prague: Orgit, 2014, s. 44. ISBN 978-80-02-02555-9. [International Congress of Chemical and Process Engineering /21./ - CHISA 2014 and Conference on Process Integration, Modelling and Optimisation for Energy Saving and Pollution Reduction /17./ - PRES 2014. Prague (CZ), 23.08.2014-27.08.2014] R&D Projects: GA ČR(CZ) GAP105/12/0664 Institutional support : RVO:67985858 Keywords : discrete element methods * mathematical modelling * particles Subject RIV: CI - Industrial Chemistry, Chemical Engineering

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

    International Nuclear Information System (INIS)

    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)

  13. Dense Pellicular Agarose-Glass Beads for Expanded Bed Application: Flow Hydrodynamics and Solid Phase Classifications

    Institute of Scientific and Technical Information of China (English)

    周鑫; 史清洪; 白姝; 孙彦

    2004-01-01

    Two dense pellicular agarose-glass matrices of different sizes and densities, i.e., AG-S and AG-L, have been characterized for their bed expansion behavior, flow hydrodynamics and particle classifications in an expanded bed system. A 26 mm ID column with side ports was used for sampling the liquid-solid suspension during expanded bed operations. Measurements of the collected solid phase at different column positions yielded the particle size and density distribution data. It was found that the composite matrices showed particle size as well as density classifications along the column axis, i.e., both the size and density of each matrix decreased with increasing the axial bed height. Their axial classifications were expressed by a correlation related to both the particle size and density as a function of the dimensionless axial bed height. The correlation was found to fairly describe the solid phase classifications in the expanded bed system. Moreover, it can also be applied to other two commercial solid matrices designed for expanded bed applications.

  14. 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...

  15. 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

  16. The Influence of Roughness and Pyrethroid Formulations on Bed Bug (Cimex lectularius L. Resting Preferences

    Directory of Open Access Journals (Sweden)

    Benjamin A. Hottel

    2015-05-01

    Full Text Available Two-choice tests were conducted to examine the effect of surface roughness on the resting preference of bed bugs, Cimex lectularius L., on copper, basswood, and acrylic materials. The influence of pyrethroid formulation applications on resting preferences was also evaluated. Bed bugs were given the choice of resting between two sanded halves of each material tested. One half was sanded with a P60 grit sandpaper and the other with a less rough P600 grit sandpaper. A significantly higher proportion of bed bugs chose to rest on the rougher P60 grit sanded half of all materials tested. Pyrethroid applications were made to either the P60 grit half or both halves of acrylic arenas and resting preferences were again assessed. Behavioral responses of bed bugs to pyrethroid formulation applications varied depending on the bed bug strain used and the formulation applied. Bed bugs would still rest on the P60 grit half when Suspend SC formulation (0.06% deltamethrin was applied; however, an avoidance response was observed from a bed bug strain susceptible to D-Force aerosol formulations (0.06% deltamethrin. The avoidance behavior is likely attributed to one, more than one, or even an interaction of multiple spray constituents and not the active ingredient.

  17. 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.

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

    International Nuclear Information System (INIS)

    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)

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

    International Nuclear Information System (INIS)

    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.

  20. Experimental studies on heat transfer and pressure drop in pebble bed test facility

    International Nuclear Information System (INIS)

    Indian program for development of high temperature reactor and its utilization to supply process heat aimed to develop alternate fuel carrier to substitute petroleum based transport fuel, which has very small reserves in India and results in large import bills. Hydrogen is an attractive energy carrier for transport applications. It can be produced by splitting water which requires either electricity or process heat at high temperatures or both depending upon the process selected. BARC is carrying out design of a 600 MWth reactor capable of supplying process heat at around 1000 °C as required for hydrogen production. For this reactor various design options with respect to fuel configurations, such as prismatic bed and pebble bed were considered for thermal hydraulics analysis. Coolant options such as molten lead and molten salt were analyzed. Studies carried out indicate selection of pebble bed reactor core with molten salt as coolant. Thermal-hydraulic studies are required for pebble bed reactor. With this in view, a pebble bed test facility has been setup to study the heat transfer and pressure drop in pebble bed. Water is used as a working medium for the facility. The paper deals with the description of the pebble bed test facility and the experimental results of heat transfer and pressure drop. It also deals with the assessment of correlations for heat transfer and pressure drop in pebble bed geometry. Pressure drop experiments in the pebble bed test facility have been performed for Raynolds number ranges from 3000-12000. Various pressure drop correlations have been compared with the experimental data. It has been found that that the correlation given by Leva et. al. matches well with the experimental data. Various heat transfer correlations have also been compared. Heat transfer experiments are nearing completion

  1. Relative role of bed roughness change and bed erosion on peak discharge increase in hyperconcentrated floods

    OpenAIRE

    Li, W.; Wang, Z. B.; van Maren, D.S.; de Vriend, H.J.; Wu, B.S.

    2014-01-01

    River floods are usually featured by a downstream flattening discharge peak whereas a downstream increasing discharge peak is observed at a rate exceeding the tributary discharge during highly silt-laden floods (hyperconcentrated floods) in China’s Yellow River. It entails a great challenge in the downstream flood defence and the underlying mechanisms need to be unravelled. Previous study on this issue only focuses on one possible mechanism, while the present work aims to reveal the relative ...

  2. Chemical and microbiological characteristics of rice husk bedding having distinct depths and used for growing-finishing swine.

    Science.gov (United States)

    Corrêa, E K; Bianchi, I; Perondi, A; de los Santos, J R G; Corrêa, M N; Castilhos, D D; Gil-Turnes, C; Lucia, T

    2009-11-01

    This study compared the effects of different bedding depths on the chemical and microbiological characteristics of the bedding material used to raise pigs during growing and finishing. The experiment was conducted in two pens housing 5 pigs from 60 to 145 days of age, with rice husk beddings 0.50 or 0.25 m deep. Four lots of pigs (replicates) were raised over time in each bedding depth: each bedding was used by two consecutive lots. Bedding samples were collected quarterly to determine the most probable number (MPN) of thermophilic and mesophilic bacteria, fungi and actinomycetes. Contents of N, P, K, C, organic, mineral and dry matter, C:N ratio and pH were also determined. The MPN of thermophilic bacteria was higher for the 0.50 m than for the 0.25 m bedding (p<0.05). The compost of 0.25 m deep bedding had a higher N, P and K content than that from the 0.50 m bedding (p<0.05). Thus, the use of the 0.25 m deep bedding would be recommended due to its greater agronomical value in comparison with the deeper bedding. PMID:19541479

  3. An overview of separation by magnetically stabilized beds: State-of-the-art and potential applications

    Institute of Scientific and Technical Information of China (English)

    Jordan Hristov; Ludmil Fachikov

    2007-01-01

    This article deals with problems relevant to implementation of magnetically stabilized beds (MSB) as separation devices. The main issues discussed are: bed mechanics, bed structure, possibilities to create controllable filter media, etc. As examples several separation techniques are discussed: dust filtration-magnetic and non-magnetic, ion-exchange, copper cementation, yeast filtration from biological liquids, particle separation by density and magnetic properties, dangerous wastes removal. Only key publications will be quoted that provide a basis for further reading and study and relevant information.

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

    Energy Technology Data Exchange (ETDEWEB)

    Bodruzzaman, M.; Essawy, M.A.

    1996-04-01

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

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

    International Nuclear Information System (INIS)

    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, P2O5 forms together with CaO thermodynamically stable Ca3(PO4)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 HPO42− and H2PO4− 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 Ca3(PO4)2 between multiple particles. - Highlights: • Coating induced agglomeration not due to K phosphates, but due to K silicates. • Melt induced agglomeration due to H2PO4− and HPO42− salts in the fuel. • Wall agglomeration corresponds to coating induced mechanism. • In-bed agglomeration corresponds to melt induced mechanism

  6. 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.; Bloomberg, J.; Mulavara, A; Seidler, R.

    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

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

    Energy Technology Data Exchange (ETDEWEB)

    Jantzen, C

    2006-09-13

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

  8. Bone metabolism and nutritional status during 30-day head-down-tilt bed rest

    OpenAIRE

    Morgan, Jennifer L. L.; Zwart, Sara R.; Heer, Martina; Ploutz-Snyder, Robert; Ericson, Karen; Smith, Scott M.

    2012-01-01

    Bed rest studies provide an important tool for modeling physiological changes that occur during spaceflight. Markers of bone metabolism and nutritional status were evaluated in 12 subjects (8 men, 4 women; ages 25–49 yr) who participated in a 30-day −6° head-down-tilt diet-controlled bed rest study. Blood and urine samples were collected twice before, once a week during, and twice after bed rest. Data were analyzed using a mixed-effects linear regression with a priori contrasts comparing all ...

  9. Mercury cycling in stream ecosystems. 2. Benthic methylmercury production and bed sediment - Pore water partitioning

    Science.gov (United States)

    Marvin-DiPasquale, M.; Lutz, M.A.; Brigham, M.E.; Krabbenhoft, D.P.; Aiken, G.R.; Orem, W.H.; Hall, B.D.

    2009-01-01

    Mercury speciation, controls on methylmercury (MeHg) production, and bed sediment - pore water partitioning of total Hg (THg) and MeHg were examined in bed sediment from eight geochemically diverse streams where atmospheric deposition was the predominant Hg input. Across all streams, sediment THg concentrations were best described as a combined function of sediment percent fines (%fines; particles water distribution coefficients (log Kd's) for both THg and MeHg were inversely related to the log-transformed ratio of pore water dissolved organic carbon (DOC) to bed sediment %fines. The stream with the highest drainage basin wetland density also had the highest pore water DOC ?? 2009 American Chemical Society.

  10. Fluidization and coating of very dense powders by fluidized bed chemical vapour deposition

    OpenAIRE

    Rodriguez, Philippe; Caussat, Brigitte; Ablitzer, Carine; Iltis, Xavière; Brothier, Méryl

    2013-01-01

    The hydrodynamic behaviour of a very dense tungsten powder, 75 µm in median diameter and 19,300 kg/m3 in grain density, has been studied in a fluidized bed at room temperature using nitrogen and argon as carrier gas. Even if fluidization was achieved, the small bed expansion indicated that it was imperfect. Then, the fluidization was studied at 400 °C in order to investigate the feasibility of coating this powder by Fluidized Bed Chemical Vapour Deposition (FBCVD). In particular, the influenc...

  11. Effects of space allocation within a deep bedded finishing system on swine growth performance, fatty acid composition and pork quality

    Science.gov (United States)

    The objectives of the current study were to determine the degree to which space allocation in a deep-bedded system influences swine performance and pork quality. The deep-bedded method employed was hoop structures which are large, tent-like shelters with cornstalks or straw for bedding. One hundred ...

  12. 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.

  13. Numerical comparison of hydrogen desorption behaviors of metal hydride beds based on uranium and on zirconium-cobalt

    Energy Technology Data Exchange (ETDEWEB)

    Kyoung, S.; Yoo, H.; Ju, H. [Department of Mechanical Engineering, Inha University, Incheon (Korea, Republic of)

    2015-03-15

    In this paper, the hydrogen delivery capabilities of uranium (U) and zirconium-cobalt (ZrCo) are compared quantitatively in order to find the optimum getter materials for tritium storage. A three-dimensional hydrogen desorption model is applied to two identically designed cylindrical beds with the different materials, and hydrogen desorption simulations are then conducted. The simulation results show superior hydrogen delivery performance and easier thermal management capability for the U bed. This detailed analysis of the hydrogen desorption behaviors of beds with U and ZrCo will help to identify the optimal bed material, bed design, and operating conditions for the storage and delivery system in ITER. (authors)

  14. Numerical comparison of hydrogen desorption behaviors of metal hydride beds based on uranium and on zirconium-cobalt

    International Nuclear Information System (INIS)

    In this paper, the hydrogen delivery capabilities of uranium (U) and zirconium-cobalt (ZrCo) are compared quantitatively in order to find the optimum getter materials for tritium storage. A three-dimensional hydrogen desorption model is applied to two identically designed cylindrical beds with the different materials, and hydrogen desorption simulations are then conducted. The simulation results show superior hydrogen delivery performance and easier thermal management capability for the U bed. This detailed analysis of the hydrogen desorption behaviors of beds with U and ZrCo will help to identify the optimal bed material, bed design, and operating conditions for the storage and delivery system in ITER. (authors)

  15. Influences on Bed Sorting and Armoring in an Upland Gravel-Cobble Bed River, Middle Fork John Day River, Oregon

    Science.gov (United States)

    McDowell, P. F.

    2014-12-01

    The Middle Fork is an unconfined to partly confined upland river with channel length of 34 km, drainage area of 250-850 km2, and channel gradients of 0.004 to 0.006 in the study area. Geology is dominated by Tertiary volcanic and volcaniclastic rocks that yield abundant coarse clasts. Surface and subsurface bed material was sampled volumetrically at twenty-five sites. The textural types range from gravelly cobbles to sandy cobbly gravels, sand content is low (2 to 13%), mud content is very low, and sorting is poor to very poor. Generally the surface layer is an open framework gravel or cobble, while the subsurface layer is a filled or partially filled framework gravel or cobble. Despite an armored appearance, only 20% of the sites are armored using the standard armor ratio (surface D50/subsurface D50). While surface layers are not coarser than their subsurface layers in terms of the median or coarse end of the distribution, they are coarser in terms of fines (ratios based on D25, D16, % sand), suggesting that alternatives to the D50armor ratio might be useful. Multivariate analysis of size fraction data reveals four distinct groups of samples, distinguished mainly by differences in proportions of coarse to fine gravels, and in abundance of sand. While one group comprises only surface samples and another subsurface samples, two of the groups are mixed. One goal of the project is to evaluate the effects of land use history on bed material characteristics and mobility. Sediment characteristics were examined in relation to distance downstream, geology, relation to debris-flow sources, land use history, and other potential influences. There are no geologic associations or downstream trends in fining or other grain size parameters. Differences in land use history, such as former dredged-mined reaches and reaches with recent restoration projects also do not explain patterns of armoring or other sediment characteristics. High variability within each reach suggests that

  16. Heat Transfer in Segregated Fluidized Beds Part 2: Particle Motion and Its Effects on the Heat transfer in the Segregated Fluidized Beds

    Science.gov (United States)

    Gu, Yihua; Satoh, Isao; Saito, Takushi; Kawaguchi, Tatsuya

    In our previous paper, particle and temperature segregations in a fluidized bed of binary particle mixtures were experimentally examined, and heat transfer in the segregated fluidized bed was investigated. As the results, it was shown that the temperature segregation results mainly from low heat transfer coefficient through the interface layer, which exists between the flotsam-rich and jetsam-rich layers, and that the heat transfer coefficient increases rapidly with increasing the excess gas velocity. Following our previous paper, particle motion in the segregated fluidized bed was experimentally investigated in this paper, in order to make quantitative discussion on the relation between the heat transfer coefficient and particle motion in the interface layer. In the experiment, the Particle Imaging Velocimetry (PIV) method was applied to study the concentration and motion of particles in the segregated fluidized bed. A modified solid circulation model was built up to model the particle motion in the segregated fluidized bed. The experiment results showed that the vertical particle exchange rate of the interface layer increases with the excess gas velocity, and that the vertical heat transfer coefficient through the interface layer is mainly determined by the average particle exchange rate in the interface layer. Variations of the apparent thermal conductivity at different height in the particle layers were also determined by the vertical variation of the particle exchange rate. It was shown that the heat transfer coefficient or the thermal conductivity in the interface layer is influenced by the densities and specific heat capacities of the particles.

  17. Esikouluikäisten lasten välinen syrjintä kasvattajan näkökulmasta

    OpenAIRE

    Voutilainen, Marjatta

    2009-01-01

    Marjatta Voutilainen. Esikouluikäisten lasten välinen syrjintä kasvattajan näkökulmasta. Helsinki, syksy 2009, 60 s., 2 liitettä. Diakonia-ammattikorkeakoulu, DIAK Etelä Helsinki. Sosiaalialan koulutusohjelma, sosionomi (AMK) + Lastentarhanopettajan virkakelpoisuus. Opinnäytetyön tavoite oli tutkia esikouluikäisten lasten syrjintään liittyviä seikkoja kasvattajan näkökulmasta. Tarkoitus oli selvittää, syrjitäänkö erilaista lasta päiväkodin vertaisryhmässä, kuinka usein ja miten mahdoll...

  18. Evaluation and Clustering Maps of Groundwater Wells in the Red Beds of Chengdu, Sichuan, China

    Directory of Open Access Journals (Sweden)

    Haijing Zhang

    2016-01-01

    Full Text Available Since the start of the 21st century, groundwater wells have been placed in red beds to solve the problem of scarce water resources in Southwest China and have rapidly expanded to other areas. By providing examples of cartography in Chengdu and Sichuan, China, and using the locations of groundwater in fractures and pores when monitoring and managing red sandstone and mudstone wells, a series of maps of groundwater wells at different scales in the red beds of Chengdu was obtained. Most of the wells located in red beds are located in Jintang, Dayi, and Qingbaijiang and exhibit different cluster features. The kernel density estimation and spatial cluster analysis classification methods were used based on the Density Based Spatial Clustering of Applications with Noise algorithm (DBSCAN in three concentrated areas. This method describes the trends of the clustering results and the relationships between the locations of residents and red bed wells. The cartography results show that the groundwater wells in red beds are mainly distributed in hilly areas and partially correspond with the locations of villages and settlements, particularly their geological and topographic factors, which satisfy the maximum requirements of water use and recycling in Southwest China. The irrigation wells located in red beds are not only reliable and efficient but also replace inefficient water resources in the recharge-runoff-discharge groundwater process, which promotes the sustainable development of groundwater resources.

  19. Upper Freeport Coal Bed County Statistics (Chemistry) in Pennsylvania, Ohio, West Virginia, and Maryland

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This dataset is a polygon coverage of counties limited to the extent of the Upper Freeport coal bed resource areas and attributed with statistics on these coal...

  20. Lower Kittanning Coal Bed County Statistics (Chemistry) in Pennsylvania, Ohio, West Virginia, and Maryland

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This dataset is a polygon coverage of counties limited to the extent of the Lower Kittanning coal bed resource areas and attributed with statistics on these coal...

  1. Pittsburgh Coal Bed County Statistics (Chemistry) in Pennsylvania, Ohio, West Virginia, and Maryland

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This dataset is a polygon coverage of counties limited to the extent of the Pittsburgh coal bed resource areas and attributed with statistics on these coal quality...

  2. Pocahontas No. 3 Coal Bed County Statistics (Geology) in Kentucky, West Virginia, and Virginia

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This dataset is a polygon coverage of counties limited to the extent of the Pocahontas No. 3 coal bed resource areas and attributed with statistics on the thickness...

  3. Pocahontas No. 3 Coal Bed County Statistics (Chemistry) in West Virginia and Virginia

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This dataset is a polygon coverage of counties limited to the extent of the Pocahontas No. 3 coal bed resource areas and attributed with statistics on these coal...

  4. Measurement of intergranular stress and porosity during dynamic compaction of porous beds of cyclotetramethylene tetranitramine

    Science.gov (United States)

    Greenaway, M. W.

    2005-05-01

    The dynamic compaction of granular beds of the propellant cyclotetramethylene tetranitramine (HMX) has been investigated using a modified split Hopkinson pressure bar system. Intergranular stress and bed porosity were simultaneously measured during controlled loading. The importance of grain size was investigated by comparing conventional HMX (mean particle size ˜260μm) to microfine HMX (hydraulically pressing the beds prior to testing. With large grains, resistance to compaction increased with the solid volume fraction. Microfine HMX behaved like low porosity conventional HMX beds in all cases. Porosity was typically reduced by 5%-10% during compaction and intergranular stresses below the yield stress were ensured. Energy dissipation to plastic flow and fracture were largely eliminated. Optical particle size analysis and electron microscopy support the experimental observations.

  5. Upper Freeport Coal Bed Remaining Resources by County in Pennsylvania, Ohio, West Virginia, and Maryland

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This dataset is a polygon coverage of counties limited to the extent of the Upper Freeport coal bed resource areas and attributed with remaining resources (millions...

  6. Pocahontas No. 3 Coal Bed Remaining Resources by County in Kentucky, West Virginia, and Virginia

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This dataset is a polygon coverage of counties limited to the extent of the Pocahontas No. 3 coal bed resource areas and attributed with remaining resource values...

  7. Upper Freeport Coal Bed Point Data (Geology) in Pennsylvania, Ohio, West Virginia, and Maryland

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This dataset is a point coverage of attributes on data location, thickness of the Upper Freeport coal bed, and its elevation, in feet. The file is also found as an...

  8. Pocahontas No. 3 Coal Bed Original Resources by County in Kentucky, West Virginia, and Virginia

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This dataset is a polygon coverage of counties limited to the extent of the Pocahontas No. 3 coal bed resource areas and attributed with original resource values...

  9. Upper Freeport Coal Bed County Statistics (Geology) in Pennsylvania, Ohio, West Virginia, and Maryland

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This dataset is a polygon coverage of counties limited to the extent of the Upper Freeport coal bed resource areas and attributed with statistics on the thickness...

  10. Pittsburgh Coal Bed Resource Areas in Pennsylvania, Ohio, West Virginia, and Maryland

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The base of the Pittsburgh Coal bed and its stratigraphically (non-coal) equivalent horizon is used to subdivide Upper Pennsylvanian Series strata into the...

  11. Pittsburgh Coal Bed County Statistics (Geology) in Pennsylvania, Ohio, West Virginia, and Maryland

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This dataset is a polygon coverage of counties limited to the extent of the Pittsburgh coal bed resource areas and attributed with statistics on the thickness of...

  12. Pittsburgh Coal Bed Original Resources by County in Pennsylvania, Ohio, West Virginia, and Maryland

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This dataset is a polygon coverage of counties limited to the extent of the Pittsburgh coal bed resource areas and attributed with original resource values...

  13. Pittsburgh Coal Bed Remaining Resources by County in Pennsylvania, Ohio, West Virginia, and Maryland

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This dataset is a polygon coverage of counties limited to the extent of the Pittsburgh coal bed resource areas and attributed with remaining resource values in...

  14. TIN Dataset Model of Overburden Above the Mahogany Bed in the Uinta Basin, Utah and Colorado

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — An ESRI TIN data model of the overburden material above the Mahogany bed was needed to perform calculations in the Uinta Basin, Utah and Colorado as part of a 2009...

  15. TIN Dataset Model of the Mahogany Bed Structure in the Uinta Basin, Utah and Colorado

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — An ESRI TIN data model of the Mahogany bed structure was needed to perform overburden calculations in the Uinta Basin, Utah and Colorado as part of a 2009 National...

  16. Raster Dataset Model of the Mahogany Bed Structure in the Uinta Basin, Utah and Colorado

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — An ESRI GRID raster data model of the Mahogany bed structure was needed to perform overburden calculations in the Uinta Basin, Utah and Colorado as part of a 2009...

  17. Raster Dataset Model of Overburden Above the Mahogany Bed in the Uinta Basin, Utah and Colorado

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — An ESRI GRID raster data model of the overburden material above the Mahogany bed was needed to perform calculations in the Uinta Basin, Utah and Colorado as part of...

  18. Pittsburgh Coal Bed Point Data (Geology) in Pennsylvania, Ohio, West Virginia, and Maryland

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This dataset is a point coverage of attributes on data location, thickness of the Pittsburgh coal bed main bench, and its elevation, in feet. The file is also found...

  19. A biphasic oxidation of alcohols to aldehydes and ketones using a simplified packed-bed microreactor

    OpenAIRE

    Andrew Bogdan; D. Tyler McQuade

    2009-01-01

    We demonstrate the preparation and characterization of a simplified packed-bed microreactor using an immobilized TEMPO catalyst shown to oxidize primary and secondary alcohols via the biphasic Anelli-Montanari protocol. Oxidations occurred in high yields with great stability over time. We observed that plugs of aqueous oxidant and organic alcohol entered the reactor as plugs but merged into an emulsion on the packed-bed. The emulsion coalesced into larger plugs upon exiting the reactor, leavi...

  20. An Experimental and Numerical Investigation of Fluidized Bed Gasification of Solid Waste

    OpenAIRE

    Sharmina Begum; Mohammad G. Rasul; Delwar Akbar; David Cork

    2013-01-01

    Gasification is a thermo-chemical process to convert carbon-based products such as biomass and coal into a gas mixture known as synthetic gas or syngas. Various types of gasification methods exist, and fluidized bed gasification is one of them which is considered more efficient than others as fuel is fluidized in oxygen, steam or air. This paper presents an experimental and numerical investigation of fluidized bed gasification of solid waste (SW) (wood). The experimental measurement of syngas...

  1. Sex of college students moderates associations among bedtime, time in bed, and circadian phase angle

    OpenAIRE

    Van Reen, Eliza; Sharkey, Katherine M.; Roane, Brandy M.; Barker, David; Seifer, Ronald; Raffray, Tifenn; Bond, Tamara L.; Carskadon, Mary A.

    2013-01-01

    Sex differences in circadian rhythms have been reported with some conflicting results. The timing of sleep and length of time in bed has not been considered, however, in previous such studies. The current study has three major aims: (1) replicate previous studies in a large sample of young adults for sex differences in sleep patterns and dim light melatonin onset (DLMO) phase; (2) in a subsample constrained by matching across sex for bedtime and time in bed, confirm sex differences in DLMO an...

  2. Reactor modeling and physicochemical properties characterization for a polyethylene fluidized bed reactor

    OpenAIRE

    F. A. N. Fernandes; L. M. F. LONA BATISTA

    1999-01-01

    A new steady state model for the fluidized bed reactor and a physicochemical characterization model were developed for the simulation of polyethylene production using gas-phase technology. The association of these models was done in order to predict the characteristics of the polymer produced in the fluidized bed reactor (molecular weight, polydispersity, melt index, and other characteristics) throughout the reactor and also to predict the growth of the polymer particle.

  3. Reactor modeling and physicochemical properties characterization for a polyethylene fluidized bed reactor

    Directory of Open Access Journals (Sweden)

    FERNANDES F. A. N.

    1999-01-01

    Full Text Available A new steady state model for the fluidized bed reactor and a physicochemical characterization model were developed for the simulation of polyethylene production using gas-phase technology. The association of these models was done in order to predict the characteristics of the polymer produced in the fluidized bed reactor (molecular weight, polydispersity, melt index, and other characteristics throughout the reactor and also to predict the growth of the polymer particle.

  4. High cell density and productivity culture of Chinese hamster ovary cells in a fluidized bed bioreactor

    OpenAIRE

    Kong, D.; Cardak, S.; Chen, M.; Gentz, R; Zhang, J.

    1999-01-01

    A recombinant Chinese hamster ovary clone was cultivated in a 2L Cytopilot Mini fluidized bed bioreactor using Cytoline 1 microcarriers and a 10L B. Braun stirred tank bioreactor with Cytodex 1 microcarriers. Cytoline 1 is a macroporous polyethylene microcarrier and Cytodex 1 is a solid DEAE-dextran microcarrier. Cytoline 1 microcarriers in the fluidized bed bioreactor were gently mixed by an uplifting flow. Circulation and sparging in Cytopilot Mini were separated from the fluidized microcar...

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

    OpenAIRE

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

    2010-01-01

    The paradigm Biometrics for Emotion Detection (BED) is introduced, which enables unobtrusive emotion recognition, taking into account varying environments. It uses the electrocardiogram (ECG) and speech, as a powerful but rarely used combination to unravel people’s emotions. BED was applied in two environments (i.e., office and home-like) in which 40 people watched 6 film scenes. It is shown that both heart rate variability (derived from the ECG) and, when people’s gender is taken into accoun...

  6. KANSAINVÄLINEN DIAKONIA PAIKALLISSEURAKUNNASSA : Tutkimus kansainvälisestä diakoniasta Suomen evankelis-luterilaisen kirkon paikallisseurakunnissa Espoon hiippakunnan alueella

    OpenAIRE

    Inkinen, Raisa

    2011-01-01

    Inkinen, Raisa. KANSAINVÄLINEN DIAKONIA PAIKALLISSEURAKUNNASSA. Tutkimus kansainvälisestä diakoniasta Suomen evankelis-luterilaisen kirkon paikallisseurakunnissa Espoon hiippakunnan alueella. Järvenpää, kevät 2011. 96 s, 2 liitettä. Diakonia-ammattikorkeakoulu, DIAK Etelä, Järvenpää. Sosiaalialan koulutusohjelma. Diakonia ja nuorisotyö. Sosionomi (ylempi AMK). Opinnäytetyössäni tutkin, mitä on kansainvälinen diakonia paikallisseurakunnassa. Tavoitteena oli tarkastella, miten...

  7. Kahden käden työtä : Lähetys ja kansainvälinen diakonia Länsi-Porin seurakunnan nuorten illoissa

    OpenAIRE

    Lahti, Tiia

    2010-01-01

    Lahti, Tiia. Kahden käden työtä. Lähetys ja kansainvälinen diakonia Länsi-Porin seurakunnan nuorten illoissa. Pori, kevät 2010. 39 sivua. 4 liitettä. Diakonia-ammattikorkeakoulu. Diak Länsi Pori. Sosiaalialan koulutusohjelma. Diakonisen sosiaalityön suuntautumisvaihtoehto, sosionomi (AMK) + diakoni. Opinnäytetyö oli kehittämishanke, joka toteutettiin yhteistyössä Länsi-Porin seurakunnan kanssa. Opinnäytetyön tavoitteena oli saada lähetys ja kansainvälinen diakonia osaksi seurakunnan n...

  8. 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

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

    DEFF Research Database (Denmark)

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

    2011-01-01

    bed rest. Research Design and Methods: Twelve young, healthy, male subjects completed 7 days of bed rest with vastus lateralis muscle biopsies taken before and after bed rest. In addition, muscle biopsies were obtained from 6 of the subjects prior to, immediately after and 3h after 45 min one......-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......-hydroxyacyl-CoA dehydrogenase and citrate synthase activity ~8% as well as miR-1 and miR-133a content ~10%. Cytochrome c and vascular endothelial growth factor (VEGF) protein content as well as capillarization did however not change significantly with bed rest. Acute exercise increased AMP-activated protein...

  10. Bed forms created by simulated waves and currents in a large flume

    Science.gov (United States)

    Lacy, Jessica R.; Rubin, David M.; Ikeda, Hiroshi; Mokudai, Kuniyasu; Hanes, Daniel M.

    2007-01-01

    The morphology and evolution of bed forms created by combinations of waves and currents were investigated using an oscillating plate in a 4-m-wide flume. Current speed ranged from 0 to 30 cm/s, maximum oscillatory velocity ranged from 20 to 48 cm/s, oscillation period was 8 s (except for one run with 12 s period), and the median grain size was 0.27 mm. The angle between oscillations and current was 90°, 60°, or 45°. At the end of each run the sand bed was photographed and ripple dimensions were measured. Ripple wavelength was also determined from sonar images collected throughout the runs. Increasing the ratio of current to wave (i.e., oscillatory) velocity decreased ripple height and wavelength, in part because of the increased fluid excursion during the wave period. Increasing the ratio of current to waves, or decreasing the angle between current and waves, increased the three-dimensionality of bed forms. During the runs, ripple wavelength increased by a factor of about 2. The average number of wave periods for evolution of ripple wavelength to 90% of its final value was 184 for two-dimensional ripples starting from a flat bed. Bed form orientations at the end of each run were compared to four potential controlling factors: the directions of waves, current, maximum instantaneous bed shear stress, and maximum gross bed form normal transport (MGBNT). The directions of waves and of MGBNT were equally good predictors of bed form orientations, and were significantly better than the other two factors.

  11. Using Acoustics to Determine Eelgrass Bed Distribution and to Assess the Seasonal Variation of Ecosystem Service

    Science.gov (United States)

    Sonoki, Shiori; Shao, Huamei; Morita, Yuka; Minami, Kenji; Shoji, Jun; Hori, Masakazu; Miyashita, Kazushi

    2016-01-01

    Eelgrass beds are an important source of primary production in coastal ecosystems. Understanding seasonal variation in the abundance and distribution of eelgrass is important for conservation, and the objectives of this study were to 1) monitor seasonal variation in eelgrass beds using an acoustic monitoring method (Quantitative echo sounder) and 2) broadly quantify the carbon circulation function. We obtained acoustic data of eelgrass beds in coastal areas north and east of Ikunojima Island. Surveys were conducted nine times over the 3-year period from 2011 to 2013 in order to monitor seasonal variation. Acoustic data were obtained and used to estimate the spatial distribution of eelgrass by geostatistical methods. To determine supporting services, we determined carbon sink and carbon fixation by eelgrass beds using data from the National Research Institute of Fisheries and Environment of Inland Sea (2011). The height and distribution of eelgrass beds were at a maximum in May and at a minimum in November of each year. Distribution trends were different between the north and east areas. Supporting services showed the same patterns throughout the year. The area of distribution was considered to be coincident with the life history of eelgrass. Distribution differed by area and changed yearly due to the effects of bottom characteristics and wind direction. Quantifying the supporting services of eelgrass beds was shown to be useful for managing the conservation of coastal ecosystems. PMID:26954673

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

    International Nuclear Information System (INIS)

    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

  13. Operating theatre scheduling with patient recovery in both operating rooms and recovery beds

    OpenAIRE

    Augusto, Vincent; Xie, Xiaolan; Perdomo, Viviana

    2010-01-01

    This paper investigates the impact of allowing patient recovery in the operating room when no recovery bed is available. Three types of identical resources are considered: transporters, operating rooms and recovery beds. A fixed number of patients must be planned over a term horizon, usually one or two weeks. The surgery process is modelled as follows: each patient is transported from the ward to the operating theatre. Then the patient visits an operating room for surgery operation and is tra...

  14. 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.

  15. 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...

  16. Relationship between the tropical seagrass beds characteristics and the structure of the associated fish community

    OpenAIRE

    Ambo-Rappe, Rohani; Nessa, Muhammad Natsir; Latuconsina, Husain; Dmitry L. LAJUS

    2013-01-01

    Structural complexity of seagrass bed including species composition and shoot density is argued to be an important factor determining fish assemblages. However statistical verification of such a relationship is possible only in areas with high species richness of seagrass and fish assemblages which is observed in tropical waters. Material for this study was collected in three seagrass beds with different structure in Inner Ambon Bay, Eastern Indonesia. This study provided evidence that higher...

  17. Seaweed farming and artisanal fisheries in an Indonesian seagrass bed - complementary or competitive usages?

    OpenAIRE

    Blankenhorn, Sven Uli

    2008-01-01

    In Indonesia, coastal villages traditionally depend on artisanal fisheries. Increasing population density and fishing pressure make alternative sources of income become more important. One possibility is seaweed farming, which has been introduced in many communities. There, algae farming is restricted to shallow waters and their natural ecosystems, e. g. seagrass beds. Seagrass beds themselves are important habitats for many fish species are the basis for fisheries. If seaweed farming causes ...

  18. The fluidized bed reactor with a prepolymerization system and its influence on polymer physicochemical characteristics

    OpenAIRE

    F. A. N. Fernandes; L. M. F. Lona

    2003-01-01

    This work addresses the influence of a prepolymerization system on the behavior of the fluidized bed reactor used for polyethylene production. Its influence on the polymer's physicochemical characteristics and production was also studied. The results indicate that the use of prepolymerized catalyst particles results in milder temperatures in the fluidized bed reactor, thus avoiding the formation of hot spots, melting of the polymer particle and reactor shutdown. Productivity can be enhanced d...

  19. 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

  20. Comments on the transition between cohesive and cohesionless sediment bed exchange

    Science.gov (United States)

    Mehta, Ashish J.; Letter, Joseph V.

    2013-10-01

    The presence of both cohesive and cohesionless particles in estuarine and lacustrine sediments makes it essential to model bed exchange of both types of particles. The usual practice is to select a purely empirical estimate of particle diameter marking the transition between the two behaviors. Based on available data on particle erosion and deposition in non-oscillating flows and viscoplastic properties of bed sediment, we have attempted to examine the likelihood of identifying the transition diameter within a less empirical framework. From the relationship between diameter and bed shear stress for a variety of cohesive and cohesionless sediments, it appears that two transition diameters can be defined. One is the largest diameter of clay mineral particles at which cohesion is considered to vanish. The other is the smallest diameter at which cohesionless behavior is assumed to end at the limit of the well-known Shields' relationship extended to very fine particles. These two diameters appear to be reasonably close for mainly inorganic mineral sediments. Assuming they are equal, six zones of bed exchange are identified in terms of diameter and bed shear stress. Depending on these two variables, zones of only erosion, no erosion or deposition, and only deposition can be designated. Realistic modeling of bed exchange of multi-size sediments requires that the full range of diameters be considered. Extension of this analysis to organic-rich sediments is pending better understanding of their rheological properties.

  1. Fabrication and test of thin double-layered annulus metal hydride bed

    International Nuclear Information System (INIS)

    Metal hydride bed for the storage and delivery of tritium is one of the essential components of tokamak fuel cycle. For the development of metal hydride bed, rapid delivery/recovery rate according to the tokamak operation scenario and accurate and rapid measurement of tritium inventory are major concerns. It has to store the tritium safely and satisfy the requirements of the facility where metal hydride bed is installed. To fulfill these requirements, we developed a thin double-layered annulus metal hydride bed. A mock-up with the capacity of 70 g tritium storage (1250 g ZrCo) is fabricated. Using hydrogen gas, the recovery and delivery performance during absorption or desorption process is tested. With 7.5 mole of H2 gas, the recovery rate of 72.5 Pa m3/s for 90% absorption and the delivery rate of 15.6 Pa m3/s for 90% desorption is achieved. The thermal insulation test and tritium inventory measurement test using in-bed gas flowing calorimetry are also performed. It took less than 24 h for the in-bed calorimetry procedure to reach the steady state.

  2. The Silurian Reservoir Bed-Differentiated Asphalts in Tarim Basin and Modeling Experiments on Their Origin

    Institute of Scientific and Technical Information of China (English)

    刘洛夫; 刘宏江; 王洪玉; 曾溅辉

    2002-01-01

    There is a type of asphalt that originated from differentiation from reservoir bed (named reservoir bed-differentiated asphalt) in the Silurian asphaltic sandstones of the Tarim Basin. These asphalts are the result of second-time charging of hydrocarbons into the Silurian reservoir, which were derived from Lower Paleozoic source rocks. Asphalt was differentiated from the reservoir bed in the hydrocarbon gathering area of secondary migration. The differen tiation is caused by changes in reservoir physical properties when pearl or chain hydrocarbons migrating through and gathering in the reservoir bed, and light components are lost and heavy ones are involved in the formation of asphalt or heavy oil. There are two kinds of occurrence of these asphalts in the Silurian system of the Tarim Basin. One is the poor heavy oil layer with lower oil saturation in trap and the other is scattered hydrocarbon distributed along the transport layer and unconformity surface. Reservoir bed-differentiated asphalts have two characteristics: total hydrocarbon content is high in extractable organic matter and the ratio of saturated to aromatic hydrocarbon is usually greater than unity. The physically modeling experiment has confirmed these characteristics and the genesis of the reservoir bed-differentiated asphalts.

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

    Science.gov (United States)

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

    2011-01-01

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

  4. 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.

  5. Packed fluidization, enhancement of heat transfer in pebble bed and thermonuclear fusion technology

    International Nuclear Information System (INIS)

    Packed fluidization is a technique in which small particles (size: 100-800 μm) are allowed to fluidize in the interstices of stationary pebbles (size: >1.0 mm). Packed fluidization enhances the rate of heat transfer in pebble bed at low operative gas velocity as well as at low pressure drop across the bed. Experiments were conducted to study heat transfer in unary packed bed and binary packed fluidized bed using lithium titanate and alumina pebbles (size: 3-10 mm) and lithium titanate and silica particles (size: 231-780 μm). It was found that due to packed fluidization the rate of heat transfer is enhanced and arms of the effective thermal conductivity this enhancement was up to 260%. Low thermal conductivity of pebble bed of solid breeder materials is one of the adverse key issues which must be addressed properly for the successful development of the thermonuclear fusion technology. Packed fluidization enhances the effective thermal conductivity of the pebble bed of solid breeder materials in the Test Blanket Module (TBM) of ITER type fusion reactor. (author)

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

    International Nuclear Information System (INIS)

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Nietert, R.E.

    1983-02-01

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

  8. 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

  9. Bed In Summer

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    In winter I get up at night And dress by yellow candle-light. In summer, quite the other way, I have to go to bed by day. I have to go to bed and see The birds still hopping on the tree, Or hear the grown-up people' s feet Still going past me in the stree

  10. Fluidized bed incinerator development

    International Nuclear Information System (INIS)

    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

  11. The COOLOCE experiments investigating the dryout power in debris beds of heap-like and cylindrical geometries

    Energy Technology Data Exchange (ETDEWEB)

    Takasuo, Eveliina, E-mail: eveliina.takasuo@vtt.fi [VTT Technical Research Centre of Finland, P.O. Box 1000, 02044 VTT, Espoo (Finland); Holmstroem, Stefan; Kinnunen, Tuomo; Pankakoski, Pekka H. [VTT Technical Research Centre of Finland, P.O. Box 1000, 02044 VTT, Espoo (Finland)

    2012-09-15

    Highlights: Black-Right-Pointing-Pointer We investigate the effect of geometry on the coolability of porous core debris beds. Black-Right-Pointing-Pointer Dryout power is measured for a heap-like (conical) and a cylindrical debris bed. Black-Right-Pointing-Pointer The coolability of the cylindrical bed is better due to the lower height of the configuration. - Abstract: The COOLOCE test facility has been used for experimental investigations of the coolability of porous core debris beds with different geometries. The main objective of the experiments was to compare the dryout behavior of conical (heap-like) and top-flooded cylindrical (evenly distributed) debris bed configurations in order to investigate the effect of geometry on the coolability of the debris bed. The experimental debris beds simulate the possible outcomes of melt discharge from the reactor pressure vessel and the formation of a core debris bed in a deep water pool during a severe accident. The results suggest that if the two debris bed configurations have equal height, the coolability of the conical bed is improved compared to the cylindrical bed due to the multi-dimensional infiltration of water through the surface of the cone. However, in case the conical and cylindrical debris beds have equal diameter and volume, the dryout power density of the conical configuration is lower than that of the cylindrical configuration by approximately 50%. This is due to the greater height of the conical configuration which leads to increased heat flux in the upper parts of the conical debris bed. According to the present results, the effect of the increased debris bed height is greater than the effect of multi-dimensional flooding. Simulations show the differences between the two-phase flow behavior of the two geometries, and the resulting difference in dryout development.

  12. The COOLOCE experiments investigating the dryout power in debris beds of heap-like and cylindrical geometries

    International Nuclear Information System (INIS)

    Highlights: ► We investigate the effect of geometry on the coolability of porous core debris beds. ► Dryout power is measured for a heap-like (conical) and a cylindrical debris bed. ► The coolability of the cylindrical bed is better due to the lower height of the configuration. - Abstract: The COOLOCE test facility has been used for experimental investigations of the coolability of porous core debris beds with different geometries. The main objective of the experiments was to compare the dryout behavior of conical (heap-like) and top-flooded cylindrical (evenly distributed) debris bed configurations in order to investigate the effect of geometry on the coolability of the debris bed. The experimental debris beds simulate the possible outcomes of melt discharge from the reactor pressure vessel and the formation of a core debris bed in a deep water pool during a severe accident. The results suggest that if the two debris bed configurations have equal height, the coolability of the conical bed is improved compared to the cylindrical bed due to the multi-dimensional infiltration of water through the surface of the cone. However, in case the conical and cylindrical debris beds have equal diameter and volume, the dryout power density of the conical configuration is lower than that of the cylindrical configuration by approximately 50%. This is due to the greater height of the conical configuration which leads to increased heat flux in the upper parts of the conical debris bed. According to the present results, the effect of the increased debris bed height is greater than the effect of multi-dimensional flooding. Simulations show the differences between the two-phase flow behavior of the two geometries, and the resulting difference in dryout development.

  13. Pattern formation in vibrated beds of dry and wet granular materials

    Science.gov (United States)

    Chuan Lim, Eldin Wee

    2014-01-01

    The Discrete Element Method was coupled with a capillary liquid bridge force model for computational studies of pattern formation in vibrated granular beds containing dry or wet granular materials. Depending on the vibration conditions applied, hexagonal, stripes, or cellular pattern was observed in the dry vibrated granular bed. In each of these cases, the same hexagonal, stripes, or cellular pattern was also observed in the spatial distribution of the magnitudes of particle-particle collision forces prior to the formation of the corresponding actual pattern in physical distributions of the particles. This seemed to suggest that the pattern formation phenomenon of vibrated granular bed systems might be the result of a two-dimensional Newton's cradle effect. In the presence of a small amount of wetness, these patterns were no longer formed in the vibrated granular beds under the same corresponding set of vibration conditions. Despite the relatively much weaker capillary forces arising from the simulated liquid bridges between particles compared with particle-particle collision forces, the spatial distributions of these collision forces, physical distributions of particles, as well as time profiles of average collision forces were altered significantly in comparison with the corresponding distributions and profiles observed for the dry vibrated granular beds. This seemed to suggest the presence of a two-dimensional Stokes' cradle effect in these wet vibrated granular bed systems which disrupted the formation of patterns in the wet granular materials that would have been observed in their dry counterparts.

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

    Directory of Open Access Journals (Sweden)

    Kamran Ansari

    2012-07-01

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

  15. Theoretical and experimental investigation on the transient coupled heat and mass transfer in a radial flow desiccant packed bed

    International Nuclear Information System (INIS)

    Highlights: ► We present theoretical and experimental investigation of desiccant bed. ► Transient coupled heat and mass transfer in a radial flow desiccant packed bed has been reported. ► A real-time model is used. ► The prediction of air exit conditions from the bed is carried out. - Abstract: Theoretical and experimental investigation on the transient coupled heat and mass transfer in a radial flow desiccant packed bed has been reported in the present work. An experimental test rig has been designed and constructed to carry out the required experimental measurements. System parameters and flowing air conditions (bed weight, air velocity, air conditions – dry and wet bulb temperatures- at exit of test rig components) are measured and analyzed. A hollow cylindrical packed bed has been used as a desiccant dehumidifier. This configuration decreases the required power to blow air through the bed. In the theoretical study, prediction of air exit conditions from the bed is carried out based on the model of Barlow for the analysis of adsorption and regeneration processes in the desiccant bed. This model uses simple effectiveness equations for steady-state heat and mass exchangers within a finite difference procedure. Air at different conditions of temperature and humidity enters the regenerated bed and the exit temperature and humidity are plotted with time. Acceptable agreement is found between the theoretical and experimental results. The most effective parameters on the system performance are the initial water content of the bed and its initial temperature. Bed cooling during adsorption improves the system performance.

  16. Quantifying the effects of hydrograph shape and flow transience on coarse sediment bed load transport

    Science.gov (United States)

    Phillips, Colin; Hill, Kimberly; Paola, Chris

    2016-04-01

    The rate of bed load transport under steady flow is known to vary both spatially and temporally due to various hydrologic and granular phenomena. Grain size distributions and riverbed properties (packing, armoring, imbrication, etc.) have been observed to affect flux for a particular value of applied flow stress while hydrology is mainly assumed to control the magnitude of the applied bed stress above the threshold for bed material entrainment. The prediction and measurement of bed load sediment transport in field settings are further complicated by the inherent transience in the flood hydrograph, but relatively little is known about how flood transience differs from a steady flow. Here we investigate the role of flood transience for gravel bed load transport through controlled laboratory experiments in a 28 m long 0.5-meter wide flume. We explore transient flow through the use of short duration hydrographs as the combination of unsteady and intermittent flow, where unsteady flow varies in magnitude over a given duration, and intermittent flow is characterized by turning the flow on and off. Experimental runs consist of sequences of steady and unsteady flood hydrographs of various shapes, but equivalent integrated excess transport capacity. These flood sequences are run for a variety of competent flow durations and peak stress magnitudes. We find that even for a narrow unimodal grain size distribution and constant sediment supply we observe clockwise hysteresis in bed load flux, different thresholds for entrainment and distrainment for the rising and falling limbs of a flood, and a threshold of entrainment that can vary from one flood hydrograph to the next. Despite complex transport phenomena at the particle scale, we find that the total bed load transported for each flood plots along a linear trend with the integrated excess transport capacity, in agreement with prior field results. These experiments indicate that while the effects of transient flow and

  17. Biochemical and hormonal changes in endurance trained volunteers during and after exposure to bed rest and chronic hyperhydration

    Science.gov (United States)

    Zorbas, Y. G.; Naexu, K. A.; Yaroshenko, Y. N.

    2000-04-01

    The objective of this investigation was to assess the effect of a daily intake of fluid and salt supplementation on biochemical and hormonal changes in endurance trained volunteers aged 19-24 yrs during 30-day bed rest and during 15 days of post bed rest period. The studies were performed on 30 long distance runners aged 19-24 yrs who had a peak oxygen uptake of 66 ml/kg/min and had taken 14.5 km/day on average prior to their participation in the study. The volunteers were divided into three groups: the volunteers in the first group were under normal ambulatory conditions (control subjects); the second group subjected to bed rest alone unsupplemented (bed rested volunteers); the third group was submitted to bed rest and consumed daily 30 ml water/kg bodyweight and 0.1 g of sodium chloride (NaCl)/kg body weight (supplemented bed rested volunteers). The second and third groups of volunteers were kept under a rigorous bed rest regime for 30 days. During the pre bed rest period of 15 days, during the bed rest period of 30 days and during the post bed rest period of 15 days cyclic adenosine monophosphate, cyclic guanosine monophosphate, prostaglandins of pressor, prostaglandins depressor groups, renin activity in plasma and aldosterone in plasma and in urine were determined. We found that in bed rested volunteers without fluid and salt supplementation intake plasma renin activity and aldosterone in plasma and urine continued to increase during the bed rest period as plasma volume decreased. Moreover, in this group, cyclic nucleotides measured as an indicator of adrenosympathetic system activity increased and prostaglandins as local vasoactive substances decreased during the bed rest period. These variables returned toward the baselines in the post bed rest period as plasma volume deficit was restituted. On the other hand, the hormonal levels in the other two groups remained rather constant during the experimental period. We concluded that daily intake of fluid and salt

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

    International Nuclear Information System (INIS)

    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/cm2. 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

  19. Pressure drops of single/two-phase flows through porous beds with multi-sizes spheres and sands particles

    International Nuclear Information System (INIS)

    Highlights: • Flow tests are performed in packed porous beds with multi-size spheres and sands. • Packed beds with similar size distributions have the similar effective particle diameters. • Reed model predicts well the pressure drop of two-phase flow through porous bed. - Abstract: This paper reports an experimental research of single and two-phase gas/liquid flow in packed porous beds composed of multi-sizes spheres and irregular particles. A test facility named DEBECO-LT is designed and constructed to investigate the friction laws of adiabatic single and two-phase flows in a porous bed. The results show that the effective diameter of multi-sizes non-spherical or irregular particles bed can be derived on the basis of bed consisted of spheres as long as they have a wide range of grain sizes and the similar size distribution. Given the effective particle diameter obtained from single-phase flow through the packed bed with multi-size spheres or irregular particles, the pressure drop of two-phase flow through the bed can be predicted by the Reed model. The experimental data provide insights for the flow characteristic of porous bed, as well as high-quality data for validation of the coolability analysis models and codes

  20. 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.

  1. Dual-Fuel Fluidized Bed Combustor Prototype for Residential Heating: Steady-State and Dynamic Behavior

    Science.gov (United States)

    Cammarota, Antonio; Chirone, Riccardo; Miccio, Michele; Sollmene, Roberto; Urcluohr, Massimo

    Fluidized bed combustion of biogenic fuels can be recognized as an attractive option for an ecologically sustainable use of biofuels in residential applications. Nevertheless, biomass combustion in fluidized bed reactors presents some drawbacks that are mainly related to mixing/segregation of fuel particles/volatile matter during devolatilization inside the bed and in the freeboard or to bed agglomeration. A prototype of a 30-50 kWth fluidized bed boiler for residential heating has been designed to burn either a gaseous combustible or a solid biomass fuel or both fuels at the same time. The prototype has been equipped with a gas burner located in the wind-box to optimize the start-up stage of the boiler and with a fluidized bed characterized by a conical geometry ("Gulf Stream" circulation) to improve the mixing of the fuel particles during both devolatilization and char burn-out. The operation of the combustor adopting wood pellets as fuel has been investigated to evaluate their use in residential combustion applications. Steady-state thermally stable regimes of operation have been recognized analyzing both boiler temperatures and gaseous emissions. The optimization of the steady-state operation of the boiler in terms of gaseous emissions has been achieved by varying the nominal thermal power and air excess. An ad-hoc experimental campaign has been carried out to analyze the dynamic performance of the prototype as a response to changes of the demanded thermal power. On the basis of the experimental data, an interpretation of the dynamic behavior of the fluidized bed boiler has been proposed.

  2. Co-firing characteristics of rice husk and coal in a cyclonic fluidized-bed combustor ({Psi}-FBC) under controlled bed temperatures

    Energy Technology Data Exchange (ETDEWEB)

    T. Madhiyanon; P. Sathitruangsak; S. Soponronnarit [Mahanakorn University of Technology, Bangkok (Thailand). Department of Mechanical Engineering

    2011-06-15

    This study extensively investigated temperature and emission characteristics, and the performance of co-firing rice husk with coal in a cyclonic fluidized-bed combustor ({Psi}-FBC) of 125 kWth nominal capacity. The {Psi}-FBC integrated the distinct features of cyclonic/vortex and fluidized-bed combustion. Fluidization, without any inert material, can be accomplished by the stirring blades and vortex ring. The combustor was equipped with a multi-passes water coil to regulate the bed temperatures, varying 800-900{sup o}C. Rice husk was co-fired with coal, a supplementary fuel, with coal blending ratios of 0-25% by thermal basis. The radial temperature profiles displayed vortex combustion along the wall, while the axial temperature profiles suggested a well-mixed condition in the lower part. The large depletion of O{sub 2} and proliferation of CO in the lower part revealed vigorous combustion beneath the vortex ring. A reducing atmosphere appeared unfavorable to NOx formation. The combustor showed satisfied E{sub c}, mostly {gt}98.5%. The optimum operating conditions with respect to NOx emissions were: (1) the thermal percentage of coal not {gt}20%, and (2) bed temperatures between 800 and 850{sup o}C. Otherwise, NOx emissions would exceed the regulations; even CO and SO{sub 2} emissions were well acceptable. 30 refs., 9 figs., 5 tabs.

  3. Getting Rid of Bed Bugs

    Science.gov (United States)

    ... how you select a company. Related Information Collaborative Strategy on Bed Bugs - highlights ways that all levels of government, community, academia and private industry can work together to reduce bed bugs across ...

  4. Circulating fluidized bed combustion in the turbulent regime: Modeling of carbon combustion efficiency and sulfur retention

    Energy Technology Data Exchange (ETDEWEB)

    Adanez, J.; Gayan, P.; Grasa, G.; Diego, L.F. de; Armesto, L.; Cabanillas, A.

    1999-07-01

    In this work carbon combustion efficiencies and sulfur retentions in CFBC under the turbulent regime were studied. Experimental results were obtained from the combustion of a lignite and an anthracite with a limestone in a CBF pilot plant with 20 cm internal diameter and 6.5 m height. The effect of operating conditions such as coal and limestone particle size distributions, temperature, excess air, air velocity and Ca/S molar ratio on carbon combustion efficiency and sulfur retention was studied. On the other hand, a mathematical model for the carbon combustion efficiencies and sulfur retentions in circulating fluidized bed combustors operating under the turbulent regime was developed. The model has been developed considering the hydrodynamics behavior of a turbulent bed, the kinetics of carbon combustion and sulfur retention in the riser. The hydrodynamics characteristics of the turbulent regime were previously studied in a cold pilot plant and equations to determine the axial and radial voidage in the bed were proposed. A core-annulus structure in the dilute region of the bed was found in this regime. Carbon combustion and sulfur retention were modeled by modifying a model developed for fast beds and taking into account turbulent regime characteristics. The experimental results of carbon combustion efficiencies and sulfur retentions were compared with those predicted by the model and a good correlation was found for all the conditions used.

  5. Do-it-yourself Bed Bug Control

    Science.gov (United States)

    ... Bed Bug Control Do-it-yourself Bed Bug Control Can you treat and eliminate the bed bugs ... all of the residents to participate. Achieving complete control can take weeks to months, depending on the ...

  6. Maximum spoutable bed height of spout-fluid bed

    Energy Technology Data Exchange (ETDEWEB)

    Wenqi Zhong; Mingyao Zhang; Baosheng Jin [Southeast University, Nanjing (China). Key Laboratory on Clean Coal Power Generation and Combustion Technology of Ministry of Education

    2006-11-15

    Experimental study on the maximum spoutable bed height of a spout-fluid bed (cross-section of 0.3 m x 0.03 m and height of 2 m) packed with Geldart group D particles has been carried out. The effects of particle size, spout nozzle size and fluidizing gas flow rate on the maximum spoutable bed height were studied. Experimental data were compared to some published experiments and predictions. The results show that the maximum spoutable bed height of spout-fluid bed decreases with increasing particle size and spout nozzle size, which appears the same trend to that of spouted beds. The increasing of fluidizing gas flow rate leads to a sharply decrease in the maximum spoutable bed height. The existent correlations of the maximum spoutable bed height in the literature were observed to involve large discrepancies. Additionally, the flow characteristics when bed materials deeper than the maximum spoutable height were summarized. Under this condition, the spout-fluid bed operated without a stable and coherent spout or fountain assembles the characteristics of jetting fluidized bed. Besides, the mechanisms of spout termination were investigated. It was found that slugging in the spout and growth of instabilities would cause the spout termination in spout-fluid bed.

  7. 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.; Phillips, T.; Platts, S. H.; Ploutz-Snyder, L. L.; Reschke, M. F.; Ryder, J. W.; Stenger, M. B.; Taylor, L. C.; Wood, S. J.

    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

  8. Systematic reviews of bed rest and advice to stay active for acute low back pain.

    Science.gov (United States)

    Waddell, G; Feder, G; Lewis, M

    1997-01-01

    BACKGROUND: In the United Kingdom (UK), 9% of adults consult their doctor annually with back pain. The treatment recommendations are based on orthopaedic teaching, but the current management is causing increasing dissatisfaction. Many general practitioners (GPs) are confused about what constitutes effective advice. AIM: To review all randomized controlled trials of bed rest and of medical advice to stay active for acute back pain. METHOD: A systematic review based on a search of MEDLINE and EMBASE from 1966 to April 1996 with complete citation tracking for randomized controlled trials of bed rest or medical advice to stay active and continue ordinary daily activities. The inclusion criteria were: primary care setting, patients with low back pain of up to 3 months duration, and patient-centred outcomes (rate of recovery from the acute attack, relief of pain, restoration of function, satisfaction with treatment, days off work and return to work, development of chronic pain and disability, recurrent attacks, and further health care use). RESULTS: Ten trials of bed rest and eight trials of advice to stay active were identified. Consistent findings showed that bed rest is not an effective treatment for acute low back pain but may delay recovery. Advice to stay active and to continue ordinary activities results in a faster return to work, less chronic disability, and fewer recurrent problems. CONCLUSION: A simple but fundamental change from the traditional prescription of bed rest to positive advice about staying active could improve clinical outcomes and reduce the personal and social impact of back pain. PMID:9474831

  9. The effect of different methods of seed bed preparation on greenhouse cucumber yield and yield components

    Directory of Open Access Journals (Sweden)

    D. Momeni

    2010-12-01

    Full Text Available To investigate the effects of different methods of seed bed preparation on yield of greenhouse cucumber, a two-year long experiment was conducted as a randomized complete block design with four replications in Jiroft from 2004. Different methods of seed bed preparation were as follows: 1 ridge with 20 cm height and 50 cm width and 2 plant rows with 40 cm distance, 2 furrow with 20 cm depth and 50 cm width and 2 plant rows inside, with 40 cm distance, and 3 planting on flat area with 40 cm distance. The results showed that the effect of planting bed on yield of greenhouse cucumber was significant. Furrow and flat area increased yield significantly, compared to the ridge treatment. Analysis of yield components such as plant height, number of pickling fruits, number of leaves, photosynthetic area and number of flowers showed that they are all correlated with fruit yield. The number of pickling fruits was significantly more in furrow and flat area than in ridge treatment. The height of cucumber plants on flat bed was significantly higher than that of the other treatments. The number of leaves and photosynthetic area of plants on flat bed were significantly greater than those in the other treatments. The least dead plants due to fungi disease were observed in ridge treatment. In view of yield and its components under the condition of this experiment, it can be concluded that flat area and furrow treatments are better than ridge treatment.

  10. Fluid-particle interaction and generation of coherent structures over permeable beds: an experimental analysis

    Science.gov (United States)

    Corvaro, Sara; Miozzi, Massimo; Postacchini, Matteo; Mancinelli, Alessandro; Brocchini, Maurizio

    2014-10-01

    We study the dynamics of the oscillatory bottom boundary layer (BBL) that develops at a porous bed under the action of propagating water waves (also known as “ventilated BBL”). In particular, experimental tests of a ventilated BBL generated over a permeable bed made of regular plastic spheres are analysed. With the purpose of characterizing typical dynamics of nearshore waves evolving over dissipative seabeds, we focus on one specific forcing condition, characterized by large nonlinearities and vorticity generation, and expect that such dynamics be qualitatively similar also for other wave regimes. Particle tracking enables an accurate definition of the hydrodynamics generated over the porous medium with specific focus on Eulerian velocity and vorticity fields and on Lagrangian particle trajectories. Nearbed velocity components are strongly influenced by the bed configuration (sphere caps) and are characterized by small-scale oscillations due to the presence of coherent structures over the interstices. Counter-rotating vortex sheets are generated and evolve during the entire wave period; their thickness grows rapidly when flow injection from the bed occurs, while it remains constant under the influence of in-bed flow suction. The evolution of near-bed particles is influenced by strain or vortex-dominated regions. When the intensity of the vortices just outside the BBL is large (generally after flow inversion), the momentum associated to the rotation of the lower layer of vortices in the BBL is comparable with that of the passive tracers, hence the particles are captured and their original trajectories are modified, jumping to a different layer. On the contrary when strain regions are dominant, particles are restricted in the same vorticity layer until sweep or ejection turbulent processes are observed and anomalous particle transport occurs from lower to higher vortex layers and vice versa. The latter occurs during the entire wave cycle, becoming the dominant

  11. Granular-bed and ceramic candle filters in commercial plants: A comparison

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, K.B.; Haas, J.C.; Eshelman, M.B.

    1993-04-01

    Advanced coal fired power cycles require the removal of coal ash at high temperature and pressure. Granular-bed and ceramic candle filters can be used for this service. Conceptual designs for commercial size applications are made for each type of filter. The filters are incorporated in the design of a Foster Wheeler 450 MWe second generation pressurized fluidized bed combustion plant which contains a pressurized fluidized combustor and carbonizer. In a second application, the inters are incorporated in the design of a 100 MWe KRW (air) gasifier based power plant. The candle filter design is state of the art as determined from the open literature with an effort to minimize the cost. The granular-bed filter design is based on test work performed at high temperature and low pressure, tests at New York University performed at high pressure and temperate, and new analysis used to simplify the scale up of the filter and reduce overall cost. The incorporation of chemically reactive granites in the granular-bed filter for the removal of additional coal derived contaminants such as alkali or sulfur is considered. The conceptual designs of the granular-bed inter and the ceramic candle filter are compared in terms of the cost of electricity, capital cost, and operating and maintenance costs for each application.

  12. Ice stream motion facilitated by a shallow-deforming and accreting bed.

    Science.gov (United States)

    Spagnolo, Matteo; Phillips, Emrys; Piotrowski, Jan A; Rea, Brice R; Clark, Chris D; Stokes, Chris R; Carr, Simon J; Ely, Jeremy C; Ribolini, Adriano; Wysota, Wojciech; Szuman, Izabela

    2016-01-01

    Ice streams drain large portions of ice sheets and play a fundamental role in governing their response to atmospheric and oceanic forcing, with implications for sea-level change. The mechanisms that generate ice stream flow remain elusive. Basal sliding and/or bed deformation have been hypothesized, but ice stream beds are largely inaccessible. Here we present a comprehensive, multi-scale study of the internal structure of mega-scale glacial lineations (MSGLs) formed at the bed of a palaeo ice stream. Analyses were undertaken at macro- and microscales, using multiple techniques including X-ray tomography, thin sections and ground penetrating radar (GPR) acquisitions. Results reveal homogeneity in stratigraphy, kinematics, granulometry and petrography. The consistency of the physical and geological properties demonstrates a continuously accreting, shallow-deforming, bed and invariant basal conditions. This implies that ice stream basal motion on soft sediment beds during MSGL formation is accommodated by plastic deformation, facilitated by continuous sediment supply and an inefficient drainage system. PMID:26898399

  13. Ice stream motion facilitated by a shallow-deforming and accreting bed

    Science.gov (United States)

    Spagnolo, Matteo; Phillips, Emrys; Piotrowski, Jan A.; Rea, Brice R.; Clark, Chris D.; Stokes, Chris R.; Carr, Simon J.; Ely, Jeremy C.; Ribolini, Adriano; Wysota, Wojciech; Szuman, Izabela

    2016-02-01

    Ice streams drain large portions of ice sheets and play a fundamental role in governing their response to atmospheric and oceanic forcing, with implications for sea-level change. The mechanisms that generate ice stream flow remain elusive. Basal sliding and/or bed deformation have been hypothesized, but ice stream beds are largely inaccessible. Here we present a comprehensive, multi-scale study of the internal structure of mega-scale glacial lineations (MSGLs) formed at the bed of a palaeo ice stream. Analyses were undertaken at macro- and microscales, using multiple techniques including X-ray tomography, thin sections and ground penetrating radar (GPR) acquisitions. Results reveal homogeneity in stratigraphy, kinematics, granulometry and petrography. The consistency of the physical and geological properties demonstrates a continuously accreting, shallow-deforming, bed and invariant basal conditions. This implies that ice stream basal motion on soft sediment beds during MSGL formation is accommodated by plastic deformation, facilitated by continuous sediment supply and an inefficient drainage system.

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

    International Nuclear Information System (INIS)

    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)

  15. 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.

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

    International Nuclear Information System (INIS)

    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. Biological and physical contributions to the accumulation of strombid gastropods in a Pliocene shell bed

    Energy Technology Data Exchange (ETDEWEB)

    Geary, D.H. (Univ. of Wisconsin, Madison (USA)); Allmon, W.D. (Univ. of South Florida, Tampa (USA))

    1990-06-01

    Before the evolutionary and ecological information contained in shell beds can be interpreted, the conditions of shell bed formation must be understood. Here the authors investigate the mode and time scale of accumulation of a dense layer of Strombus floridanus in the Pliocene Pinecrest Beds of Florida. They utilize a variety of comparative taphonomic data, including the extent of encrustation and boring on strombid shells of different ontogenetic ages, and on accompanying pelecypods of different ecological types. The taphonomic comparisons enable them to reconstruct more accurately the events of shell bed formation. The formation of the strombid shell layer involved both biological and physical components. The characteristically gregarious behavior of Strombus is reflected in the large number of individuals preserved in this layer. Based on average densities of individuals in strombid colonies today, the authors estimate that a time period of tens to hundreds of years was required to accumulate these fossils. Repeated sediment winnowing by storms, followed by rapid reburial in a regime of at least episodically high sedimentation rates, is the most likely mechanism of accumulation, and accounts for the observed patterns of encrustation and boring on the shells of Strombus and various associated pelecypods. The origin of Florida's Plio-Pleistocene shelly sands is poorly understood; analysis of this bed may provide a working model for future taphonomic studies.

  18. Linking Radial Species Segregation and Bubbling Patterns in Gas-Fluidized Beds.

    Science.gov (United States)

    Joseph, Gustavo; Hrenya, Christine; Kozlowski, Joe

    2007-11-01

    Binary mixtures of gas-fluidized Geldart Group B particles with size and/or density differences were experimentally investigated at gas velocities up to 3 times the complete fluidization velocities (ufc) of the mixtures. Steady state operation of the bed was ensured prior to data collection. Local bubbling information (mean bubble size, bubble rise velocity, and bubbling frequency) was obtained throughout the bed by means of a backscattered-light optical probe. Segregation data were obtained via bed ``freezing'' and subsequent sieving of layers. Monodisperse runs were also performed as benchmarks for the binary-mixture runs. Perceptible radial variations in species composition were encountered, with the less massive particles tending toward the bed center in most cases. For systems where the species differed in both size and density, the bottom layer presents a reversal of radial segregation pattern at gas velocities below 2ufc. At velocities below 2ufc, bubbling is seen predominantly at the bed periphery, with qualitative differences between monodisperse and mixed systems above 2ufc. A detailed analysis of the bubbling patterns at the various compositions and gas velocities is presented, and links to the observed segregation behavior are made.

  19. Evaporation and Flow of Coolant at the Bottom of a Particle-Bed modelling Relocated Debris

    International Nuclear Information System (INIS)

    Subject of the presented work is the experimental investigation of cooling-mechanisms which set in after the relocation of molten debris to the lower plenum during a nuclear accident with core melt. Emphasis is put on the influence of the bottom area of the porous debris. Experiments are carried out with a bed of steel balls (Diam = 2 and 4 mm), heated with an induction coil. The particle-bed is located inside a glass trough with inclining bottom. The particle-bed represents a section from the lower plenum of the RPV. At present, the model-fluid R134a is used and heating rates of up to 560 kW/m2 per unit horizontal cross-sectional area of the article-bed are realized. With these experiments, the evaporation inside the particle-bed and the resulting flow of liquid and gaseous coolant and the influence of an inclining bottom are investigated in detail. The results obtained in the first steady-state experiments and transient experiments are presented and discussed. (authors)

  20. Modeling and Simulation of Fixed Bed Adsorption Column using Integrated CFD Approach

    Directory of Open Access Journals (Sweden)

    A.M. Shariff

    2010-01-01

    Full Text Available The understanding of detailed fluid flow in the fixed bed adsorption column is substantially crucial since the mass and heat transfer in the bed is influenced by the column hydrodynamics. In this study, an integrated CFD model was developed to model and simulate the adsorption dynamics and hydrodynamics of gaseous fluid (CH4 and CO2 mixture in the fixed bed adsorption column. The developed integrated model was used to determine the CO2 concentration factor at the column (which indicating the CO2 adsorption capacity as a function of time, based on different operating conditions. The simulated results were compared with experimental data and found to give a good agreement with error less than 2.5%. The effect of various influencing parameters such as feed velocity, bed porosity and feed concentration were studied to investigate their influences on the CO2 adsorption capacity. Besides, the effect of inlet CO2 concentration on the bed temperature profile was also studied in the present study.

  1. 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.

  2. 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. PMID:26930351

  3. The influence of carmustine wafer implantation on tumor bed cysts and peritumoral brain edema.

    Science.gov (United States)

    Hasegawa, Yuzo; Iuchi, Toshihiko; Sakaida, Tsukasa; Yokoi, Sana; Kawasaki, Koichiro

    2016-09-01

    The development of perifocal edema and tumor bed cyst has been reported after implantation of biodegradable carmustine wafers for the treatment of malignant gliomas. We retrospectively evaluated these changes in a series of patients; 19 consecutive patients with malignant glioma who received carmustine wafer implantation at our hospital from January 2013 through July 2013, and 28 patients who underwent surgery prior to our institution's initiation of carmustine wafer implantation, as historical controls. The volume of the tumor bed cyst and perifocal edema was calculated on MRI acquired at four time points: ⩽72hours after surgery for baseline, and at 1-4, 5-8, and 9-12weeks after surgery. The volume of the tumor bed cyst in the wafer group increased significantly relative to the control group at all time points (p=0.04). Opening of the ventricle was inversely correlated with enlargement of the tumor bed cyst in the wafer group (p=0.04). The change in the volume of perifocal edema in the wafer group was not significantly different (p=0.48), but exhibited a considerable increase in patients with anaplastic oligodendroglioma relative to glioblastoma patients in the wafer group (p=0.01). We demonstrated significant enlargement of the tumor bed cyst volume after carmustine wafer implantation, as well as the development of marked perifocal edema in patients with anaplastic oligodendroglioma. PMID:27430412

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

    International Nuclear Information System (INIS)

    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)

  5. 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.

  6. The methods of tumors bed localization and boost dose delivery during conservative breast cancer treatment

    International Nuclear Information System (INIS)

    Breast-conserving therapy (BCT) consists of whole breast irradiation, usually at a dose of 50 Gy, and a boost dose of 10-20 Gy to the tumor bed. A decreased risk of local recurrence in patients administered the boost has been confirmed in a large randomized trial. The precise localization of the tumor bed (boost dose volume) is often difficult, while the recommended intraoperative placement of metal markers into the tumor cavity walls is not always performed. It is more common to localize the tumor bed using other available data, such as tumor site at the initial clinical examination or mammograms, skin scar localization, postoperative induration of the mammary gland, and histological examination. All these methods are considered less exact than the volume outlined by surgical clips. Alternative approaches allowing precise delivery of radiotherapy to the tumor bed are intraoperative placement of brachytherapy catheters or intraoperative external beam irradiation. In this review we discuss the methods used of determining the tumor bed and the different radiotherapy boost techniques used in breast cancer patients managed with BCT. We also present guidelines of the American Brachytherapy Society for the use of brachytherapy as a boost method. (author)

  7. Evaluation of packed-bed and fluidized-bed cell technology for the destruction and removal of contaminants in alkaline waste solutions. Final report

    International Nuclear Information System (INIS)

    Disposing of the large quantity of nuclear waste that has been produced within the DOE complex is an area of active research and development. Electrochemical processes have been reported for the treatment of alkaline wastes including the destruction of nitrate and nitrite and the removal of metals such as Tc and Ru. Electrolytic recovery of metals from dilute solution has been reported using conventional porous electrodes such as felt electrode and reticulated electrode, but use of such electrodes is limited. The pores of such electrodes become blocked as a consequence of metal deposition. If an attempt is made to regenerate these electrodes by dissolution of the deposited metals, oxygen evolution on the matrix competes with dissolution of metals deposited within the pores. On the other hand, the use of three dimensional packed-bed and fluidized-bed electrodes having large surface area per unit volume would offer an improvement on felt or reticulated system because of the greater ease of regeneration

  8. Evaluation of packed-bed and fluidized-bed cell technology for the destruction and removal of contaminants in alkaline waste solutions. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Hobbs, D.T. [Westinghouse Savannah River Co., Aiken, SC (United States); Bockris, J.O.M.; Kim, Jinseong [Texas A& M Univ., College Station, TX (United States). Surface Electrochemistry Laboratory

    1995-12-31

    Disposing of the large quantity of nuclear waste that has been produced within the DOE complex is an area of active research and development. Electrochemical processes have been reported for the treatment of alkaline wastes including the destruction of nitrate and nitrite and the removal of metals such as Tc and Ru. Electrolytic recovery of metals from dilute solution has been reported using conventional porous electrodes such as felt electrode and reticulated electrode, but use of such electrodes is limited. The pores of such electrodes become blocked as a consequence of metal deposition. If an attempt is made to regenerate these electrodes by dissolution of the deposited metals, oxygen evolution on the matrix competes with dissolution of metals deposited within the pores. On the other hand, the use of three dimensional packed-bed and fluidized-bed electrodes having large surface area per unit volume would offer an improvement on felt or reticulated system because of the greater ease of regeneration.

  9. Reynolds averaged theory of turbulent shear flows over undulating beds and formation of sand waves.

    Science.gov (United States)

    Bose, Sujit K; Dey, Subhasish

    2009-09-01

    Based on the Reynolds averaged Navier-Stokes (RANS) equations and the time-averaged continuity equation, a theory of turbulent shear flow over an undulating sand bed is developed addressing the instability criterion of plane sand beds in free-surface flows leading to the formation of sand waves. In the analysis, the integration of RANS equations leads to generalized Saint Venant equations, in which the time-averaged streamwise velocity is characterized by a power law obtained from turbulence closure, treating the curvilinear streamlines by the Boussinesq approximation. As a consequence, the modified pressure distribution has a departure from the traditionally linear hydrostatic pressure distribution. The instability analysis of a plane sand bed yields the curves of the Froude number versus nondimensional wave number, determining an instability zone for which at lower Froude numbers (less than 0.8), the plane bed becomes unstable with the formation of dunes; whereas at higher Froude numbers, the plane bed becomes unstable with the formation of standing waves and antidunes. For higher Froude numbers, the experimental data for antidunes lie within the unstable zone; while for lower Froude numbers, the same is found for dunes with some experimental scatter. PMID:19905209

  10. Sorting out sand and gravel : sediment transport and deposition in sand-gravel bed rivers

    NARCIS (Netherlands)

    Kleinhans, M.G.

    2002-01-01

    The general aim of this PhD-project was to gain better understanding of the sediment transport and depositional processes of sand-gravel mixtures in rivers with subaqueous dunes. The understanding of the fundamental processes of sediment transport and deposition in channel beds is crucial for morpho

  11. 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...

  12. Development and stability of bed forms: a numerical analysis of dune pattern coarsening and giant dunes

    Science.gov (United States)

    Gao, Xin; Narteau, Clement; Rozier, Olivier

    2015-04-01

    We investigate the development and stability of transverse dunes for ranges of flow depths and velocities using a cellular automaton dune model. Subsequent to the initial bed instability, dune pattern coarsening is driven by bed form interactions. Collisions lead to two types of coalescence associated with upstream or downstream dominant dunes. In addition, a single collision-ejection mechanism enhances the exchange of mass between two consecutive bed forms (through-passing dunes). The power-law increases in wavelength and amplitude exhibit the same exponents, which are independent of flow properties. Contrary to the wavelength, dune height is not only limited by flow depth but also by the strength of the flow. Superimposed bedforms may propagate and continuously destabilize the largest dunes. Then, we identify three classes of steady-state transverse dune fields according to the periodicity in crest-to-crest spacing and the mechanism of size limitation. In all cases, the steady state is reached when the bed shear stress in the dune trough regions is close to its critical value for motion inception. Such a critical shear stress value is reached and maintained through the dynamic equilibrium between flow strength and dune aspect ratio. Comparisons with natural dune fields show that many of them may have reached such a steady state. Finally, we infer that the sedimentary patterns in the model may be used to bring new constraints on the stability of modern and ancient dune fields.

  13. 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.

  14. Thermal Fatigue and Creep Assessment for the ITER Tritium SDS bed

    International Nuclear Information System (INIS)

    As the tritium is absorbed and desorbed, the primary vessel is heated to 500 .deg. C and cool down to the room temperature. During this procedure, high alternating thermal stress occurs in the primary vessel. Fatigue analysis is conducted with the information of the magnitude and the number of the calculated cyclic load. In case that the duration for which the bed stay in high temperature increases, thermal creep effects should be evaluated. This paper describes the thermal fatigue and creep assessment for the SDS bed. For the ITER tritium SDS bed, thermal fatigue and creep assessments were performed. A new operation procedure to obtain more integrity margin was recommended. On the contrary, the other operation procedure should be considered which makes the rapid heating and cooling operation possible at the cost of giving up the marginal integrity

  15. Thermal Fatigue and Creep Assessment for the ITER Tritium SDS bed

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Woo-seok; Park, Chang-kyu; Ju, Young-sun [KAERI, Daejeon (Korea, Republic of); Kang, Hyun-goo; Jang, Min-ho; Yun, Sei-hun [National Fusion Research Institute, Daejeon (Korea, Republic of)

    2015-05-15

    As the tritium is absorbed and desorbed, the primary vessel is heated to 500 .deg. C and cool down to the room temperature. During this procedure, high alternating thermal stress occurs in the primary vessel. Fatigue analysis is conducted with the information of the magnitude and the number of the calculated cyclic load. In case that the duration for which the bed stay in high temperature increases, thermal creep effects should be evaluated. This paper describes the thermal fatigue and creep assessment for the SDS bed. For the ITER tritium SDS bed, thermal fatigue and creep assessments were performed. A new operation procedure to obtain more integrity margin was recommended. On the contrary, the other operation procedure should be considered which makes the rapid heating and cooling operation possible at the cost of giving up the marginal integrity.

  16. Interactions between SO2 and NOx emissions in fluidised bed combustion of coal. Doctoral thesis

    Energy Technology Data Exchange (ETDEWEB)

    Lin, W.

    1994-01-01

    ;Contents: Introduction; The emissions of SO2 and NOx and their interactions in fluidized-bed combustion (FBC) of coal; SO2 and NOx emissions in FBC of coal: a literature survey; Oxidation of NH3 in a fixed bed; Oxidation of NH3: influence of SO2, CO and CO2; Modeling SO2 and NOx emissions in AFBC: a simple approach; Modeling SO2 and NOx emissions in CFBC; Modeling SO2 and NOx emissions in FBC: a fundamental approach; Optimization and Conclusions.

  17. The metabolic and hemodynamic effects of prolonged bed rest in normal subjects

    Science.gov (United States)

    Chobanian, A. V.; Lille, R. D.; Tercyak, A.; Blevins, P.

    1974-01-01

    Investigation in six normal subjects of the effects of chronic bed rest on the interrelationships between cardiovascular hemodynamics, catecholamine metabolism, vascular reactivity, renin and aldosterone activity, and electrolyte and fluid balance. Negative sodium and potassium balances and reductions in plasma volume were observed in all subjects, but plasma renin activity and aldosterone secretory rate showed no significant change. Other findings included the observation that major decreases in sodium balance and plasma volume occurred in the early bed rest period and did not correlate closely with the degree of orthostatic intolerance.

  18. Analysis of the in-pile operation and preliminary results of the post irradiation dismantling of the pebble bed assemblies

    Energy Technology Data Exchange (ETDEWEB)

    Magielsen, A.J.; Peeters, M.M.W.; Hegeman, J.B.J.; Stijkel, M.P.; Laan, J.G. van der [NRG-Nuclear Research and Consultancy Group (Netherlands)

    2007-07-01

    The Pebble Bed Assemblies (PBA) are four tritium breeding sub scale modules, representing a segment of the European Helium Cooled Pebble Bed Test Blanket. The objective of these experiments is the study the thermomechanical behaviour of the pebble bed assemblies during irradiation. This objective will be full- filled by the analysis of changes in the in-pile temperature profiles during irradiation and the post irradiation examination of the pebble beds in the Hot Cells. The PBA has been irradiated in the HFR in Petten for 294 Full Power Days (FPD), to a dose of 2-3 dpa in Eurofer, and estimated lithium burnup of 2-3 %. Changes in the temperature profile during in-pile operation are indication for pebble bed creep compaction during first start up and the possible formation gas gaps between the pebble beds and the structure. During progressive irradiation the radial and axial differential temperatures within the breeder and beryllium pebble beds are evaluated. During start up of the sub sequent irradiation cycles (each 26 FPD) the temperature differences within the beryllium pebble beds show a slight increase suggesting changes in the structure of the pebble beds. The PBA are transported from the HFR to the Hot Cell Laboratory in upright position to maintain the gas gaps between the pebble beds and Eurofer. Various microscopy preparation techniques are used to study the deformation state of the pebble beds (signs of creep compaction and sintering), formation of gas gaps between the pebble beds and structural materials and the interaction layers between eurofer-ceramic and eurofer-beryllium. In this paper first results on the Post Irradiation examination are given. (orig.)

  19. Instability and the formation of bubbles and the plugs in fluidized beds

    Directory of Open Access Journals (Sweden)

    Piotr Schulz

    2004-01-01

    Full Text Available This is an review paper, particulary concentrate on results not many researches by reason that are explain in the text. We consider stability of disperse, two-phase flow (gas-solid particles or liquid-solid particles linear and non-linear. In particular we discuss the result of Anderson, Sundareson and Jackson (1995 [Anderson K., Sundareson S., Jackson R.: Instabilities and the formation of bubbles in fluidized beds. J. Fluid Mech. 303 (1995, 327-366] that for vertical dispersion flow one- and two-dimensional, they attack problem growing disturbances directly by numerical integration of equations of motion from given initial conditions (using computer Cray C-90. In principle, this would allow authors to explore all aspects of dynamical behaviour of fluidized beds. It is interesting mechanism of periodic plug describing by Anderson et al. and attest by other researchers. Second part of paper is more general, dedicate the problem of linear stability of uniformly fluidized state ("fluidized bed". We make the most important stages of calculations (after to Jackson (2000 [Jackson R.: The Dynamics of Fluidized Particles. Cambridge University Press 2000] and demonstrate that the majority (but not all of fluidized beds with parameters having technical importance is unstable, or stable in narrow interval of wave numbers \\(k\\.

  20. Difficulties in access and estimates of public beds in intensive care units in the state of Rio de Janeiro

    Science.gov (United States)

    Goldwasser, Rosane Sonia; Lobo, Maria Stella de Castro; de Arruda, Edilson Fernandes; Angelo, Simone Aldrey; Silva, José Roberto Lapa e; de Salles, André Assis; David, Cid Marcos

    2016-01-01

    ABSTRACT OBJECTIVE To estimate the required number of public beds for adults in intensive care units in the state of Rio de Janeiro to meet the existing demand and compare results with recommendations by the Brazilian Ministry of Health. METHODS The study uses a hybrid model combining time series and queuing theory to predict the demand and estimate the number of required beds. Four patient flow scenarios were considered according to bed requests, percentage of abandonments and average length of stay in intensive care unit beds. The results were plotted against Ministry of Health parameters. Data were obtained from the State Regulation Center from 2010 to 2011. RESULTS There were 33,101 medical requests for 268 regulated intensive care unit beds in Rio de Janeiro. With an average length of stay in regulated ICUs of 11.3 days, there would be a need for 595 active beds to ensure system stability and 628 beds to ensure a maximum waiting time of six hours. Deducting current abandonment rates due to clinical improvement (25.8%), these figures fall to 441 and 417. With an average length of stay of 6.5 days, the number of required beds would be 342 and 366, respectively; deducting abandonment rates, 254 and 275. The Brazilian Ministry of Health establishes a parameter of 118 to 353 beds. Although the number of regulated beds is within the recommended range, an increase in beds of 122.0% is required to guarantee system stability and of 134.0% for a maximum waiting time of six hours. CONCLUSIONS Adequate bed estimation must consider reasons for limited timely access and patient flow management in a scenario that associates prioritization of requests with the lowest average length of stay. PMID:27191155

  1. MODELING MOISTURE DIFFUSIVITY AND ENERGY CONSUMPTION OF CANTALOUPE SEEDS IN FIXED AND FLUIDIZED BED CONDITIONS

    Directory of Open Access Journals (Sweden)

    Reza Amiri Chayjan

    2012-12-01

    Full Text Available   Background.The main goal in cantaloupe seed drying is the reduction of its moisture content to a safe level, allowing storage in a long period of time. Fluidized bed dryer is a drying process with better heat and mass transfer and shorter drying time. This method is a gentle and uniform drying procedure. Fluidized bed is suitable for sensitive and high moisture materials. Drying parameters of moisture diffusivity and energy are vitally important in modelling and optimizing of the seed dryer system. Material and methods. This study investigated thin layer characteristics of cantaloupe seeds under fixed, semi fluidized and fluidized bed drying with initial moisture content about 61.99% (d.b.. A laboratory fluid- ized bed dryer was utilized in this research. Air temperature levels of 45, 55, 65 and 75°C were applied in drying experiments. Effective moisture diffusivity (Deff of cantaloupe seeds was computed by Fick’s second law in diffusion. Activation energy and specific energy consumption of cantaloupe seeds under different drying conditions were calculated. Results.Calculated values of Deff for drying experiments were in the range of 2.23·10-10and 8.61·10-10m2/s. Values of Deff increased as the input air temperature increased. Activation energy values were computed be- tween 39.21 and 37.55 kJ/mol for 45°C to 75°C, respectively. Specific energy consumption for cantaloupe seeds was calculated at the boundary of 1.58·105and 6.18·105kJ/kg. Conclusion.Results indicated that applying the fluidized bed condition is more effective for convective drying of cantaloupe seeds. Increasing air velocity tends to decrease in activation energy. Decreasing in drying air temperature in different bed conditions caused increase in the energy value. The aforesaid drying parameters are necessary to optimize the operational condition of fluidized bed dryer and to perfect design of the system.  

  2. Water temperatures within spawning beds in two chalk streams and implications for salmonid egg development

    Science.gov (United States)

    Acornley, R. M.

    1999-02-01

    Water temperatures within brown trout (Salmo trutta L.) spawning gravels were measured in two Hampshire chalk streams from October 1995 to April 1996 inclusive. During the winter, mean intra-gravel water temperatures were higher than those in the stream, and increased with depth in the gravel bed. The amplitude of diel fluctuations in water temperature decreased with depth in the gravel bed, although diel fluctuations were still evident at a depth of 30 cm. Differences in intra-gravel temperature gradients between the two study sites were attributed to differences in the amplitude of stream water temperature fluctuations and there was no evidence that either of the study sites were located in zones of upwelling groundwater. Published equations are used to predict, from temperature, the timing of important stages in the development of brown trout embryos (eyeing, hatching and emergence) for eggs spawned in the autumn and winter and buried at different depths in the gravel bed.

  3. 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....

  4. Seasonal Greenland Ice Sheet ice flow variations in regions of differing bed and surface topography

    Science.gov (United States)

    Sole, A. J.; Livingstone, S. J.; Rippin, D. M.; Hill, J.; McMillan, M.; Quincey, D. J.

    2015-12-01

    The contribution of the Greenland Ice Sheet (GrIS) to future sea-level rise is uncertain. Observations reveal the important role of basal water in controlling ice-flow to the ice sheet margin. In Greenland, drainage of large volumes of surface meltwater to the ice sheet bed through moulins and hydrofracture beneath surface lakes dominates the subglacial hydrological system and provides an efficient means of moving mass and heat through the ice sheet. Ice surface and bed topography influence where meltwater can access the bed, and the nature of its subsequent flow beneath the ice. However, no systematic investigation into the influence of topographic variability on Greenland hydrology and dynamics exists. Thus, physical processes controlling storage and drainage of surface and basal meltwater, and the way these affect ice flow are not comprehensively understood. This presents a critical obstacle in efforts to predict the future evolution of the GrIS. Here we present high-resolution satellite mapping of the ice-surface drainage network (e.g. lakes, channels and moulins) and measurements of seasonal variations in ice flow in south west Greenland. The region is comprised of three distinct subglacial terrains which vary in terms of the amplitude and wavelength and thus the degree to which basal topography is reflected in the ice sheet surface. We find that the distribution of surface hydrological features is related to the transfer of bed topography to the ice sheet surface. For example, in areas of thinner ice and high bed relief, moulins occur more frequently and are more uniformly dispersed, indicating a more distributed influx of surface-derived meltwater to the ice sheet bed. We investigate the implications of such spatial variations in surface hydrology on seasonal ice flow rates.

  5. Design report on SCDAP/RELAP5 model improvements - debris bed and molten pool behavior

    International Nuclear Information System (INIS)

    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

  6. Design report on SCDAP/RELAP5 model improvements - debris bed and molten pool behavior

    Energy Technology Data Exchange (ETDEWEB)

    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.

  7. An overview of the issues: physiological effects of bed rest and restricted physical activity

    Science.gov (United States)

    Convertino, V. A.; Bloomfield, S. A.; Greenleaf, J. E.

    1997-01-01

    Reduction of exercise capacity with confinement to bed rest is well recognized. Underlying physiological mechanisms include dramatic reductions in maximal stroke volume, cardiac output, and oxygen uptake. However, bed rest by itself does not appear to contribute to cardiac dysfunction. Increased muscle fatigue is associated with reduced muscle blood flow, red cell volume, capillarization and oxidative enzymes. Loss of muscle mass and bone density may be reflected by reduced muscle strength and higher risk for injury to bones and joints. The resultant deconditioning caused by bed rest can be independent of the primary disease and physically debilitating in patients who attempt to reambulate to normal active living and working. A challenge to clinicians and health care specialists has been the identification of appropriate and effective methods to restore physical capacity of patients during or after restricted physical activity associated with prolonged bed rest. The examination of physiological responses to bed rest deconditioning and exercise training in healthy subjects has provided significant information to develop effective rehabilitation treatments. The successful application of acute exercise to enhance orthostatic stability, daily endurance exercise to maintain aerobic capacity, or specific resistance exercises to maintain musculoskeletal integrity rather than the use of surgical, pharmacological, and other medical treatments for clinical conditions has been enhanced by investigation and understanding of underlying mechanisms that distinguish physical deconditioning from the disease. This symposium presents an overview of cardiovascular and musculoskeletal deconditioning associated with reduced physical work capacity following prolonged bed rest and exercise training regimens that have proven successful in ameliorating or reversing these adverse effects.

  8. Comparison of fibre optical measurements and discrete element simulations for the study of granulation in a spout fluidized bed

    OpenAIRE

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

    2007-01-01

    Spout fluidized beds are frequently used for the production of granules or particles through granulation. The products find application in a large variety of applications, for example detergents, fertilizers, pharmaceuticals and food. Spout fluidized beds have a number of advantageous properties, such as a high mobility of the particles, which prevents undesired agglomeration and yields excellent heat transfer properties. The particle growth mechanism in a spout fluidized bed as function of p...

  9. Comparison of fibre optical measurements and discrete element simulations for the study of granulation in a spout fluidized bed

    OpenAIRE

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

    2006-01-01

    Spout fluidized beds are frequently used for the production of granules or particles through granulation. The products find application in a large variety of applications, for example detergents, fertilizers, pharmaceuticals and food. Spout fluidized beds have a number of advantageous properties, such as a high mobility of the particles, which prevents undesired agglomeration and yields excellent heat transfer properties. The particle growth mechanism in a spout fluidized bed as function of p...

  10. Comparison of the Pentax Airwayscope, Glidescope Video Laryngoscope, and Macintosh Laryngoscope During Chest Compression According to Bed Height

    Science.gov (United States)

    Kim, Wonhee; Lee, Yoonje; Kim, Changsun; Lim, Tae Ho; Oh, Jaehoon; Kang, Hyunggoo; Lee, Sanghyun

    2016-01-01

    Abstract We aimed to investigate whether bed height affects intubation performance in the setting of cardiopulmonary resuscitation and which type of laryngoscope shows the best performance at each bed height. A randomized crossover manikin study was conducted. Twenty-one participants were enrolled, and they were randomly allocated to 2 groups: group A (n = 10) and group B (n = 11). The participants underwent emergency endotracheal intubation (ETI) using the Airwayscope (AWS), Glidescope video laryngoscope, and Macintosh laryngoscope in random order while chest compression was performed. Each ETI was conducted at 2 levels of bed height (minimum bed height: 68.9 cm and maximum bed height: 101.3 cm). The primary outcomes were the time to intubation (TTI) and the success rate of ETI. The P value for statistical significance was set at 0.05 and 0.017 in post-hoc test. The success rate of ETI was always 100% regardless of the type of laryngoscope or the bed height. TTI was not significantly different between the 2 bed heights regardless of the type of laryngoscope (all P > 0.05). The time for AWS was the shortest among the 3 laryngoscopes at both bed heights (13.7 ± 3.6 at the minimum bed height and 13.4 ± 4.7 at the maximum bed height) (all P laryngoscope was not significantly shorter than that of Macintosh laryngoscope at the minimum height (17.6 ± 4.0 vs 19.6 ± 4.8; P = 0.02). The bed height, whether adjusted to the minimum or maximum setting, did not affect intubation performance. In addition, regardless of the bed height, the intubation time with the video laryngoscopes, especially AWS, was significantly shorter than that with the direct laryngoscope during chest compression. PMID:26844477

  11. A STUDY OF EMOTIONAL INTELLIGENCE OF DEGREE AND B.ED. COLLEGE TEACHERS OF RAJASTHAN IN RELATION TO GENDER

    OpenAIRE

    Rajender Kumar

    2016-01-01

    This study aimed to find out difference in emotional intelligence of degree and B.Ed. college teachers of Rajasthan. The Emotional Intelligence Scale by Dr.Vinit Khera, Ms.Puja Ahuja and Ms.Sarabjit Kaur was used to assess the emotional intelligence of degree and B.Ed. college teachers of Rajasthan. The scale was administered on 160 degree and B.Ed. college teachers. The present study revealed that there is no significant difference in emotional intelligence of degree and B.Ed. college teachers.

  12. A STUDY OF TEACHER EFFECTIVENESS OF DEGREE AND B.ED. COLLEGE TEACHERS OF RAJASTHAN IN RELATION TO LOCALITY

    OpenAIRE

    Rajender Kumar

    2016-01-01

    This study aimed to find out difference in teacher effectiveness of degree and B.Ed. college teachers of Rajasthan. The Teacher Effectiveness Scale by Dr.Shallu Puri and Prof. S.C. Gakhar was used to assess the teacher effectiveness of degree and B.Ed. college teachers of Rajasthan. The scale was administered on 160 degree and B.Ed. college teachers. The present study revealed that there is no significant difference in teacher effectiveness of degree and B.Ed. college teachers.

  13. Palynologic and petrographic variation in the Otter Creek coal beds (Stephanian, Upper Carboniferous), Western Kentucky

    Energy Technology Data Exchange (ETDEWEB)

    Helfrich, C.T.; Hower, J.C. (Eastern Kentucky University, Richmond (USA))

    1989-08-30

    The palynology and petrology of the Lisman (Lower Otter Creek) and Upper Otter Creek coals of the Stephanian portion of the Sturgis Formation of the Western Kentucky coal field was investigated in samples from mine and roadcut exposures. The Lisman coal bed exhibits an upward decrease in palynologic diversity and an upward increase in inertinite macerals. These factors suggest a change in swamp paleoecology in response to a climate which was gradually becoming drier. The Upper Creek coal bed exhibits less lateral continuity in palynomorph assemblages than does the Lisman. The Upper Otter Creek palynomorph assemblages are less diverse than the Lisman assemblages. Overall, the variation in the Upper Otter Creek coal bed cannot be attributed with certainty to any factor other than the local relief within the swamp. 17 refs., 4 figs., 3 tabs.

  14. Study of instrumentation needs for process control and safety in coal fluidized-bed combustion systems

    Energy Technology Data Exchange (ETDEWEB)

    Herzenberg, C.L.; Griggs, K.E.; Henry, R.F.; Podolski, W.F.

    1981-02-01

    A study was conducted to evaluate the current state of the art of instrumentation for planned and operating fluidized-bed combustion systems. This study is intended to identify instrumentation needs and serve as a data base for projects to develop this instrumentation. A considerable number of needs for measurements for which presently available instrumentation is not suitable were reported by respondents. The identified deficiencies are presented with the associated physical parameter ranges for FBC processes. New techniques and instrumentation under development, as well as some available alternative instruments, are discussed briefly. Also, newly instituted mechanisms for technical information exchange on instrumentation for fossil energy applications are identified. Development of instruments to meet the identified measurement deficiencies is recommended in order to ensure the feasibility of automatic control of large-scale fluidized-bed combustion systems, and to advance the state of the art of fluidized-bed combustion technology.

  15. Evaluation and Clustering Maps of Groundwater Wells in the Red Beds of Chengdu, Sichuan, China

    OpenAIRE

    Haijing Zhang; Qingyun Du; Min Yao; Fu Ren

    2016-01-01

    Since the start of the 21st century, groundwater wells have been placed in red beds to solve the problem of scarce water resources in Southwest China and have rapidly expanded to other areas. By providing examples of cartography in Chengdu and Sichuan, China, and using the locations of groundwater in fractures and pores when monitoring and managing red sandstone and mudstone wells, a series of maps of groundwater wells at different scales in the red beds of Chengdu was obtained. Most of the w...

  16. Neurogenetic and morphogenetic heterogeneity in the bed nucleus of the stria terminalis

    International Nuclear Information System (INIS)

    Neurogenesis and morphogenesis in the rat bed nucleus of the stria terminalis (strial bed nucleus) were examined with [3H]thymidine autoradiography. For neurogenesis, the experimental animals were the offspring of pregnant females given an injection of [3H]thymidine on 2 consecutive gestational days. Nine groups of embryos were exposed to [3H]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

  17. Stream and bed temperature response to partial-retention forest harvesting in a coastal headwater catchment

    Science.gov (United States)

    Moore, R. D.; Guenther, S.; Gomi, T.

    2012-12-01

    This study quantified the effects of partial-retention forest harvesting on stream and bed temperatures in a headwater catchment in coastal British Columbia, Canada. Stream temperature was recorded between 2002 and 2005 at four sites, three located within the harvested area and one upstream. Logging occurred in autumn 2004. Shallow groundwater temperatures, along with bed temperature profiles at depths of 1 to 30 cm, were recorded at 10-minute intervals in two hydrologically distinct reaches beginning in 2003 or 2004, depending on the site. The lower reach had smaller discharge contributions via lateral inflow from the hillslopes and fewer areas with upwelling and/or neutral flow across the stream bed compared to the middle reach. Based on a paired-catchment analysis, the logging treatment resulted in higher daily maximum stream and bed temperatures but smaller changes in daily minima. Changes in daily maximum stream temperature, averaged over July and August of the post-harvest year, ranged from 1.6 to 3 oC at different locations within the cut block. Post-harvest changes in bed temperature in the lower reach were lower than the changes in stream temperature, greater at sites with downwelling flow, and decreased with depth at both upwelling and downwelling sites, dropping to about 1 oC at a depth of 30 cm. In the middle reach, changes in daily maximum bed temperature, averaged over July and August, were generally about 1 oC and did not vary significantly with depth. The pre-harvest regression models for shallow groundwater were not suitable for applying the paired-catchment analysis to estimate the effects of harvesting.

  18. Processes and parameters involved in modeling radionuclide transport from bedded salt repositories. Final report. Technical memorandum

    International Nuclear Information System (INIS)

    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

  19. Sex of college students moderates associations among bedtime, time in bed, and circadian phase angle.

    Science.gov (United States)

    Van Reen, Eliza; Sharkey, Katherine M; Roane, Brandy M; Barker, David; Seifer, Ronald; Raffray, Tifenn; Bond, Tamara L; Carskadon, Mary A

    2013-12-01

    Sex differences in circadian rhythms have been reported with some conflicting results. The timing of sleep and length of time in bed have not been considered, however, in previous such studies. The current study has 3 major aims: (1) replicate previous studies in a large sample of young adults for sex differences in sleep patterns and dim light melatonin onset (DLMO) phase; (2) in a subsample constrained by matching across sex for bedtime and time in bed, confirm sex differences in DLMO and phase angle of DLMO to bedtime; (3) explore sex differences in the influence of sleep timing and length of time in bed on phase angle. A total of 356 first-year Brown University students (207 women) aged 17.7 to 21.4 years (mean = 18.8 years, SD = 0.4 years) were included in these analyses. Wake time was the only sleep variable that showed a sex difference. DLMO phase was earlier in women than men and phase angle wider in women than men. Shorter time in bed was associated with wider phase angle in women and men. In men, however, a 3-way interaction indicated that phase angles were influenced by both bedtime and time in bed; a complex interaction was not found for women. These analyses in a large sample of young adults on self-selected schedules confirm a sex difference in wake time, circadian phase, and the association between circadian phase and reported bedtime. A complex interaction with length of time in bed occurred for men but not women. We propose that these sex differences likely indicate fundamental differences in the biology of the sleep and circadian timing systems as well as in behavioral choices. PMID:24336420

  20. Co-combustion of biomass and gaseous fuel in a novel configuration of fluidized bed: Thermal characteristics

    International Nuclear Information System (INIS)

    Highlights: • Jetting-fountain fluidized bed enables smooth co-firing of biomass and gaseous fuel. • Applying jetting-fountain configuration dampens greatly freeboard overheating. • Heat gain by bed greatly increases with jetting-fountain configuration. • Increasing gaseous fuel ratio causes more reduction in freeboard overheating. • Heat gain by bed considerably increases with increasing gaseous fuel ratio. - Abstract: Experimental study on co-combustion of rice straw and natural gas has been performed in a fluidized bed. The used combustor allows the novel, jetting-fountain configuration and the conventional operation as well. In the jetting-fountain configuration, natural gas premixed with the air sufficient for combustion proceeds through the jet pipe to create a jetting-fountain zone. Whereas only the air required for rice straw combustion passes through the gas distributor. The experiments show that smooth combustion of natural gas with rice straw can be performed in the jetting-fountain fluidized bed avoiding acoustic effects and explosions of burning bubbles that occurs in conventional operation. The jetting-fountain fluidized bed is shown to dampen greatly the freeboard overheating at particularly lower bed temperatures. This is because the fountain-particles absorb a great part of heat released in the freeboard and recover it back to the bed. It is confirmed by measuring the in-bed cooling load that was found to increase considerably at lower bed temperatures. The natural gas contribution is found to play a major role when applying the jetting-fountain configuration. Increasing the natural gas contribution enlarges the fountain zone that causes greater reduction in the freeboard overheating and recovers more heat back to the bed. Measuring the in-bed cooling also approves the later conclusion

  1. 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

    contributions believed to play a prominent role in cross-shore boundary layer and sediment transport processes: (1) converging-diverging effects from bed slope, (2) wave skewness, (3) wave asymmetry, and (4) waves combined with superposed negative currents (intended to loosely represent, for example, return...... 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...... 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...

  2. Radionuclide concentrations in bed sediment and fish tissue within the Rio Grande drainage basin

    International Nuclear Information System (INIS)

    In 1992-93, Los Alamos National Laboratory collaborated with the U.S. Geological Survey in an effort to characterize radionuclide concentrations in bed sediment and fish tissue within the Rio Grande drainage basin from Colorado to Texas. Bed sediment was sampled from 18 locations for cesium (137Cs), tritium (3H), strontium (90Sr), plutonium (238Pu and 239Pu), americium (241Am), total uranium (totU) and alpha, beta, and gamma activity. Fish tissue was sampled from 12 locations for 137Cs, 90Sr, 238Pu, 239Pu and totU

  3. Radionuclide concentrations in bed sediment and fish tissue within the Rio Grande drainage basin

    Energy Technology Data Exchange (ETDEWEB)

    Booher, J.L.; Fresquez, P.R.; Carter, L.F.; Gallaher, B.M.; Mullen, M.A.

    1998-02-01

    In 1992-93, Los Alamos National Laboratory collaborated with the U.S. Geological Survey in an effort to characterize radionuclide concentrations in bed sediment and fish tissue within the Rio Grande drainage basin from Colorado to Texas. Bed sediment was sampled from 18 locations for cesium ({sup 137}Cs), tritium ({sup 3}H), strontium ({sup 90}Sr), plutonium ({sup 238}Pu and {sup 239}Pu), americium ({sup 241}Am), total uranium ({sup tot}U) and alpha, beta, and gamma activity. Fish tissue was sampled from 12 locations for {sup 137}Cs, {sup 90}Sr, {sup 238}Pu, {sup 239}Pu and {sup tot}U.

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

    Science.gov (United States)

    Hartvig, Pål; Kjelsberg, Ellen

    2009-01-01

    In 1939, Lionel Penrose published a cross-sectional study from 18 European countries, including the Nordic, in which he demonstrated an inverse relationship between the number of mental hospital beds and the number of prisoners. He also found strong negative correlations between the number of mental hospital beds and the number of deaths attributed to murder. He argued that by increasing the number of mental institution beds, a society could reduce serious crimes and imprisonment rates. The aim of the study was to test Penrose's theories longitudinally by monitoring the capacity of all psychiatric institutions and prisons in a society over time. From official statistics, we collected and systematized all relevant information regarding the number of mental institution beds and prisoners in Norway during the years 1930-2004, along with major crime statistics for the same period. During the years 1930-59, there was a 2% population-adjusted increase in mental institution beds and a 30% decrease in the prison population. During 1960-2004, there was a 74% population-adjusted decrease in mental institution beds and a 52% increase in the prison population. The same period saw a 500% increase in overall crime and a 900% increase in violent crimes, with a concurrent 94% increase in the size of the country's police force. Penrose's law proved remarkably robust in the longitudinal perspective. As opposed to Penrose, however, we argue that the rise in crime rates only to a very limited extent can be attributed to mental health de-institutionalization. PMID:18985517

  5. Flow velocities and bed shear stresses in a stone cover under an oscillatory flow

    DEFF Research Database (Denmark)

    Stenanato, F.; Nielsen, Anders Wedel; Sumer, B. Mutlu;

    2010-01-01

    I order to get a better understanding of the interaction between the wave-induced, near-bed oscillatory flow, the stome cover and the sea bed, physical model tests were carried out. The tests were conducted in an oscillating water tunnel. The bottom of the tunnes was covered by one, two and three...... layers of stones. The flow velocities in the pores of the stones were measured using LDA (Laser Doppler Anemometer). In addition to the velocity measurements, the bed shear stresses were also measured using a hotfilm (Constant Temperature Anemometry). It is found that the boundary layer of the outer flow...... current boundary layer without any externally generated turbulence. The bd shear stress is found to be very low, more than ten times smaller than in the case of a smooth base bottom without stone cover....

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

    DEFF Research Database (Denmark)

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

    2008-01-01

    tolerance of anion exchangers when binding DNA. However, more importantly. with the adsorbents examined here. attempts to reduce bed aggregation by feedstock conditioning with added salt may increase DNA binding leading to a reduction in expanded bed adsorption performance compromising protein capture...... ligand densities to be examined. Very high dynamic binding capacities at 10% breakthrough were found in the absence of added salt. However, the highest binding capacities (similar to 10 and similar to 19mg DNA ml(-1) gel) were found in buffers containing added salt at concentrations of either 0.25 or 0......) even though the dynamic binding capacity was reduced as DNA concentration was increased. The extent of bed contraction during DNA loading was found to be a function of added salt concentration and ligand density of the adsorbent. The results imply that ligand density significantly affects the salt...

  7. 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

    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...... decomposition over bed material, and homogeneous thermal decomposition was negligible. However, at higher levels in the combustor the solids concentration is lower: at the top 60% of the N2O destruction was due to thermal decomposition and in the cyclone heterogeneous destruction of N2O was insignificant. It...

  8. A Three-Point Method for Separating Incident and Reflected Waves over A Sloping Bed

    Institute of Scientific and Technical Information of China (English)

    CHANG Hsien-Kuo

    2002-01-01

    This study presents a three-point method for separating incident and reflected waves to explain normally incident waves' propagating over a sloping bed. Linear wave shoaling is used to determine changes in wave amplitude and phase in response to variations of bathymetry. The wave reflection coefficient and incident amplitude are estimated from wave heights measured at three fixed wave gauges with unequal spacing. Sensitivity analysis demonstrates that the proposed method can predict the reflection and amplitude of waves over a sloping bed more accurately than the two-point method.

  9. Behavior of Alkali Metals and Ash in a Low-Temperature Circulating Fluidized Bed (LTCFB) Gasifier

    DEFF Research Database (Denmark)

    Narayan, Vikas; Jensen, Peter Arendt; Henriksen, Ulrik Birk;

    2016-01-01

    W and a 6 MW LTCFBgasifier. Of the total fuel ash entering the system, the largest fraction (40−50%) was retained in the secondary cyclone bottoms,while a lower amount (8−10%) was released as dust in the exit gas. Most of the alkali and alkaline earth metals were retained inthe solid ash, along with Si......, the low reactor temperature ensures that high-alkali biomass fuels canbe used without risk of bed defluidization. This paper presents the first investigation of the fate of alkali metals and ash in lowtemperaturegasifiers. Measurements on bed material and product gas dust samples were made on a 100 k...

  10. Pore and surface diffusion of liquid-phase multicomponent adsorption in fixed beds I

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jae Wye; Yoon, Se Hoon; Kim, Chul [Ajou University, Suwon (Korea, Republic of); Lee, Hwo Keun; Oh, Won Zin [Korea Atomic Energy Research Insititute, Taejon (Korea, Republic of)

    1997-12-31

    The adsorption capacity were measured through two-stage adsorption experiment with the adsorption isotherm and flow system. The 3 and more activate carbons were selected with surface area and pore size distribution, the adsorption relation of cl{sub 2} were reviewed with the characteristics of the activate carbon, 500 ppm cl{sub 2} (v/v in helium, in flow system) were selected and analyzed with G. C. The variation of adsorption rate were checked with the adsorption capacity in adsorption bed (shallow bed). Through the results, it is possible to design activate carbon adsorption of single component cl{sub 2}. (author) 2 refs., 3 figs.

  11. Pore and surface diffusion of liquid-phase multicomponent adsorption in fixed beds I

    International Nuclear Information System (INIS)

    The adsorption capacity were measured through two-stage adsorption experiment with the adsorption isotherm and flow system. The 3 and more activate carbons were selected with surface area and pore size distribution, the adsorption relation of cl2 were reviewed with the characteristics of the activate carbon, 500 ppm cl2 (v/v in helium, in flow system) were selected and analyzed with G. C. The variation of adsorption rate were checked with the adsorption capacity in adsorption bed (shallow bed). Through the results, it is possible to design activate carbon adsorption of single component cl2. (author) 2 refs., 3 figs

  12. Experimental investigation of thermal conductivity coefficient and heat exchange between fluidized bed and inclined exchange surface

    Directory of Open Access Journals (Sweden)

    B. Stojanovic

    2009-06-01

    Full Text Available The paper presents experimental research of thermal conductivity coefficients of the siliceous sand bed fluidized by air and an experimental investigation of the particle size influence on the heat transfer coefficient between fluidized bed and inclined exchange surfaces. The measurements were performed for the specific fluidization velocity and sand particle diameters d p=0.3, 0.5, 0.9 mm. The industrial use of fluidized beds has been increasing rapidly in the past 20 years owing to their useful characteristics. One of the outstanding characteristics of a fluidized bed is that it tends to maintain a uniform temperature even with nonuniform heat release. On the basis of experimental research, the influence of the process's operational parameters on the obtained values of the bed's thermal conductivity has been analyzed. The results show direct dependence of thermal conductivity on the intensity of mixing, the degree of fluidization, and the size of particles. In the axial direction, the coefficients that have been treated have values a whole order higher than in the radial direction. Comparison of experimental research results with experimental results of other authors shows good agreement and the same tendency of thermal conductivity change. It is well known in the literature that the value of the heat transfer coefficient is the highest in the horizontal and the smallest in the vertical position of the heat exchange surface. Variation of heat transfer, depending on inclination angle is not examined in detail. The difference between the values of the relative heat transfer coefficient between vertical and horizontal heater position for all particle sizes reduces by approximately 15% with the increase of fluidization rate.

  13. Flow visualizing study of fluidized bed for incineration and/or coal combustion technology

    Energy Technology Data Exchange (ETDEWEB)

    Ozawa, Mamoru [Kansai Univ., Suita, Osaka (Japan). Faculty of Engineering

    1997-02-01

    A simulated fluidized-bed heat exchanger was visualized using a neutron radiography system. The void fraction distribution and its fluctuation were obtained by means of an image processing technique. On the basis of the processed image, the mechanism of a large particle movement and the flow pattern in the tube bank immersed in the bed were investigated. Observed flow pattern in the tube bank indicated an importance of the tube arrangement on the void fraction fluctuation and thus the heat transfer around tubes. (author)

  14. Status and future prospects of fluidised bed firing systems in Germany

    Energy Technology Data Exchange (ETDEWEB)

    Nies, Michael [Stadtwerke Duisburg AG, Duisburg (Germany); Niemeyer, Peter [Ahlstrom Osnabrueck GmbH, Osnabrueck (Germany); Roeper, Bernhard [RWE Power AG, Grevenbroich (Germany); Werther, Joachim [Hamburg Univ. of Technology, Hamburg (Germany); Mueller, Ludwig [VGB PowerTech e.V., Essen (Germany)

    2012-07-01

    Until the 1990s, fluidised bed combustion was restricted to 350 MW of output, today, plants up to 600 MW are possible. The most important German concepts are presented by selected examples. These comprise mainly co-generation plants and industrial power plants with process steam extraction, biomass-fired plants with 20 MW as well as waste incineration plants and sewage sludge mono combustion system. According to market conditions, it is to be expected that decentralised plants with heat utilisation and flexible duo unit plants as well as fluidised bed combustion plants are going to be competitive. (orig.)

  15. 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.)

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

    International Nuclear Information System (INIS)

    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)

  17. 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

  18. Comparison between finite volume and lattice-Boltzmann method simulations of gas-fluidised beds: bed expansion and particle-fluid interaction force

    Science.gov (United States)

    Third, J. R.; Chen, Y.; Müller, C. R.

    2016-07-01

    Lattice-Boltzmann method (LBM) simulations of a gas-fluidised bed have been performed. In contrast to the current state-of-the-art coupled computational fluid dynamics-discrete element method (CFD-DEM) simulations, the LBM does not require a closure relationship for the particle-fluid interaction force. Instead, the particle-fluid interaction can be calculated directly from the detailed flow profile around the particles. Here a comparison is performed between CFD-DEM and LBM simulations of a small fluidised bed. Simulations are performed for two different values of the superficial gas velocity and it is found that the LBM predicts a larger bed expansion for both flowrates. Furthermore the particle-fluid interaction force obtained for LBM simulations is compared to the force which would be predicted by a CFD-DEM model under the same conditions. On average the force predicted by the CFD-DEM closure relationship is found to be significantly smaller than the force obtained from the LBM.

  19. The fluidized bed reactor with a prepolymerization system and its influence on polymer physicochemical characteristics

    Directory of Open Access Journals (Sweden)

    Fernandes F.A.N.

    2003-01-01

    Full Text Available This work addresses the influence of a prepolymerization system on the behavior of the fluidized bed reactor used for polyethylene production. Its influence on the polymer's physicochemical characteristics and production was also studied. The results indicate that the use of prepolymerized catalyst particles results in milder temperatures in the fluidized bed reactor, thus avoiding the formation of hot spots, melting of the polymer particle and reactor shutdown. Productivity can be enhanced depending on the operational conditions used in the prepolymerization reactor.

  20. Condition and Extent of the Natural Oyster Beds and Barren Bottoms in the Vicinity of Apalachicola, Fla.

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — A survey of oyster beds in the vicinity of Apalachicola, FL was conducted in 1915. The area of the oyster beds is 7,135 acres, or 11.1 square miles, of which...

  1. Comparison of waste water treatment between completely mixed and fluidised bed reactor; development and structure of biomass

    Energy Technology Data Exchange (ETDEWEB)

    Toman, M.; Mejac, B.

    1988-08-01

    The aerobic biological treatment of waste water from production of semisynthetic antibiotics in a completely mixed reactor and in a fluidised bed reactor was studied. The formation and development of new biomass on the sand of a fluidised bed was observed, so that differences in the structure of organisms of the concomitant biocenosis could be detected. In a fluidised bed reactor the same quality of treatednwater was gained on account of a 4-5 times higher volumetric and hydraulic loading as it was the case with a conventional activated sludge plant. The biocenosis of the fluidised bed was abundant in individua and species. The biofilm of the sand depended on substrate degradation rate as well as on rubbing among the sand particles. An optimal biofilm developed on the sand of a fluidised bed reactor 10 to 15 days after the experiment had began, and that condition remained unchanged as the experiment continued.

  2. A review of dryout heat fluxes and coolability of particle beds. APRI 4, Stage 2 Report

    Energy Technology Data Exchange (ETDEWEB)

    Lindholm, Ilona [VTT Energy, Helsinki (Finland)

    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{sup 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{sup 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 {approx} 5 mm particles is 500 kW/m{sup 2} to 1 MW/m{sup 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

  3. Study on madder pigment dyeing linen fabric by ultrasonic method%超声波法茜草色素上染亚麻织物工艺探讨

    Institute of Scientific and Technical Information of China (English)

    伍玉娟; 王晴洁; 曹红梅

    2015-01-01

    在天然染料茜草色素上染亚麻织物时,借助超声波的作用对亚麻织物进行预处理后再染色以及超声波直接染色。探索出超声波对亚麻预处理的优化工艺:改性温度40℃,改性时间20 min,频率42.5 kHz。超声波直接染色的优化工艺:染色温度30℃,染色时间20 min,频率43.5 kHz。超声波直接染色织物的表面得色量较高,颜色鲜艳,皂洗牢度好,匀染性好,耗时短。%The madder pigment of natural dye dyes linen fabrics with dyeing after pretreatment and ultrasonic directly dyeing. Optimal conditions for linen fabric pretreatment with ultrasonic was as following: modification temperature 40℃, modification time 20 min, frequency 42.5 kHz. The optimal conditions for ultrasonic direct dyeing was that of dyeing temperature 30℃, dyeing time 20 min, frequency 43.5 kHz. The color of dyed fabrics which were dyed by ultrasonic method directly is deep and fresh. The soaping fastness and level dyeing property of dyed fabrics are excellent and the time-consuming of dyeing is short.

  4. Permeability restoration and lowering of uranium leakage from leached ore beds

    Energy Technology Data Exchange (ETDEWEB)

    Burgman, H.A.; Grant, D.C.

    1981-06-02

    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.

  5. Permeability restoration and lowering of uranium leakage from leached ore beds

    International Nuclear Information System (INIS)

    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

  6. Enuresis (Bed-Wetting)

    Science.gov (United States)

    ... get out of bed to go to the bathroom. When do most children achieve bladder control? Children ... ask questions about your child's daytime and nighttime bathroom habits. Then your doctor will do a physical ...

  7. Particle fuel bed tests

    International Nuclear Information System (INIS)

    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 H2 for 12 hours with no visible reaction or weight loss

  8. PACE: A test bed for the dynamics and control of flexible multibody systems

    Science.gov (United States)

    Kwak, Moon K.; Smith, Monty J.; Das, Alok

    1993-01-01

    The Phillips Laboratory at Edwards AFB has constructed a test bed for the validation and comparison of modeling and control theories for the dynamics and control of flexible multibody systems. This project is called the Planar Articulating Controls Experiment (PACE). This paper presents the experimental apparatus for PACE and the problem formulation. An in-depth analysis on DC motor dynamics was also performed.

  9. 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.

    1999-01-01

    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

  10. Plutonium destruction with pebble bed type HTGRs using Pu burner balls and breeder balls

    International Nuclear Information System (INIS)

    It was made clear that pebble bed type HTGRs using Pu burner balls (pu balls) and breeder balls (Th balls) possesses a potential to burn weapons-grade Pu to 740 Gwd/TPu. The total amounts of Pu and 239Pu of can reduced to about 20 and 1%, respectively. (author). 10 refs, 4 figs, 2 tabs

  11. 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...

  12. Modeling of fluidized-bed combustion of coal: Phase II, final reports. Volume V. Appendix: stability and instability in fluidized-bed combustion

    Energy Technology Data Exchange (ETDEWEB)

    Louis, J.F.; Tung, S.E.

    1980-10-01

    This document is the fifth of the seven volumes series of our Phase II Final Report. The material developed in this volume has not been incorporated into the system model. It will be used as a precursor of a transient model to be developed in the next phase of our model work. There have been various fluidized combustor models of differing complexity and scope published in the literature. Most of these models have identified and predicted - often in satisfactory agreement with results from pilot units - the key steady state combustor characteristics such as the mass of carbon in the bed (carbon loading), the combustion efficiency, the sulfur retention by the solid sorbent and the pollutant (mainly NO/sub x/) emissions. These models, however, cannot be in most instances successfully used to study the extinction and ignition characteristics of the combustor because they are isothermal in structure in the sense that the bed temperature is not an output variable but rather an input one and must be a priori specified. In order to remedy these inadequacies of the previous models, we here present a comprehensive account of the formulation and some typical results of a new nonisothermal model which has been developed in order to study, among other things, the ignition and extinction characteristics of the AFBC units. This model is able to predict the temperature patterns in the bed, the carbon loading, the combustion efficiency and the O/sub 2/ and CO concentration profiles in the combustor for the different design or operational characteristics.

  13. Fuel bed evaluations and coal properties transformation in a Sasol-Lurgi fixed bed dry bottom gasifier operating on North Dakota lignite / Setobane Jonas Mangena

    OpenAIRE

    Mangena, Setobane Jonas

    2008-01-01

    The growth in coal consumption worldwide as well as the high oil prices in the recent past has led to the current increased interest in the application of coal gasification technologies. The Sasoi-Lurgi Fixed Bed Dry Bottom (S-L FBDB) gasification technology is one such technology that has the biggest market share in the world and maintains its competitive edge particularly with regard to gasification of low grade and low rank coal. To ensure sustained competitive advantage through tech...

  14. Intermittent pool beds are permanent cyclic habitats with distinct wet, moist and dry phases.

    Directory of Open Access Journals (Sweden)

    Anthony I Dell

    Full Text Available Recognition that intermittent pools are a single habitat phase of an intermittent pool bed that cycles between aquatic and terrestrial habitat greatly enhances their usefulness for addressing general questions in ecology. The aquatic phase has served as a model system in many ecological studies, because it has distinct habitat boundaries in space and time and is an excellent experimental system, but the aquatic to terrestrial transition and terrestrial phase remain largely unstudied. We conducted a field experiment within six replicate natural intermittent pool beds to explore macroinvertebrate community dynamics during the transition from aquatic to terrestrial habitat and during the terrestrial phase. We monitored and compared macroinvertebrate communities within leaf packs that i remained wet, ii underwent drying (i.e., started wet and then dried, and iii remained dry. Our results show that i a diverse macroinvertebrate community inhabits all phases of intermittent pool beds, ii pool drying involves colonization by an assemblage of macroinvertebrates not recorded in permanently terrestrial leaf packs, iii the community within dried leaf packs remains distinct from that of permanently terrestrial leaf packs for an extended period following drying (possibly until subsequent refilling, and iv there are likely to be strong spatial and temporal resource linkages between the aquatic and terrestrial communities. The unique environmental characteristics of intermittent pool beds, which repeatedly cycle from aquatic to terrestrial habitat, should continue to make them valuable study systems.

  15. Flow of River Tigris and its Effect on the Bed Sediment within Baghdad, Iraq

    Science.gov (United States)

    Al-Ansari, Nadhir; Ali, Ammar A.; Al-Suhail, Qusay; Knutsson, Sven

    2015-12-01

    River Tigris is a major river in Iraq. Sediment at the bed of the river within a reach of about 18 km from the center of Baghdad upstream was investigated. Sixty five cross sections were surveyed, and 46 sediment samples were collected and analyzed. It was noticed that fine sand was dominant in the bed (90.74%). The average median size within the reach was 2.49 phi (0.177 mm), while the mean size was 2.58 phi (0.16 mm). In addition, the sediments were moderately sorted, fine skewed and leptokurtic. The size of the bed sediment decreased relative to previous investigations due to the construction of the Adhaim dam on tributary, which used to be the main sediment supplier to the Tigris River before entering Baghdad. Furthermore, the discharge of the Tigris River for the period 1983-2013 (715 m3/s) decreased by about 40% and 30%since 1983when compared with the periods 1931-1956 (1208 m3/s) and 1956-1980 (1015 m3/s), respectively, due to climate change and construction of dams upstream from Baghdad. This has decreased the capacity and the competence of the river. The bed elevation has increased compared to previous surveys. Itwas noticed that dredging operations and obstructions (e.g. fallen bridges and islands) have disturbed the flow of the river and sediment characteristics in several sites.

  16. Alarm pheromones and chemical communication in nymphs of the tropical bed bug Cimex hemipterus (Hemiptera: Cimicidae.

    Directory of Open Access Journals (Sweden)

    H Christoph Liedtke

    Full Text Available The recent resurge of bed bug infestations (Cimex spp.; Cimicidae and their resistance to commonly used pesticides calls for alternative methods of control. Pheromones play an important role in environmentally sustainable methods for the management of many pest insects and may therefore be applicable for the control of bed bugs. The tropical bed bug, Cimex hemipterus, is a temporary ectoparasite on humans and causes severe discomfort. Compared to the common bed bug, Cimex lectularius, little is known about the chemical signalling and pheromone-based behaviour of the tropical species. Here, we show that the antennal morphology and volatile emission of C. hemipterus closely resembles those of C. lectularius and we test their behavioural responses to conspecific odour emissions. Two major volatiles are emitted by male, female and nymph C. hemipterus under stress, (E-2-hexenal and (E-2-octenal. Notably, nymph emissions show contrasting ratios of these compounds to adults and are further characterized by the addition of 4-oxo-(E-2-hexenal and 4-oxo-(E-2-octenal. The discovery of this nymph pheromone in C. hemipterus is potentially the cause of a repellent effect observed in the bio-tests, where nymph odours induce a significantly stronger repellent reaction in conspecifics than adult odours. Our results suggest that pheromone-based pest control methods developed for C. lectularius could be applicable to C. hemipterus, with the unique nymph blend showing promising practical properties.

  17. Numerical investigation of coupled heat and mass transfer during desorption of hydrogen in metal hydride beds

    Energy Technology Data Exchange (ETDEWEB)

    Muthukumar, P.; Satheesh, A.; Madhavakrishna, U.; Dewan, Anupam [Department of Mechanical Engineering, Indian Institute of Technology Guwahati, Guwahati 781039, Assam (India)

    2009-01-15

    This paper presents a numerical investigation of two-dimensional coupled heat and mass transfer processes in MmNi{sub 4.6}Fe{sub 0.4} and MmNi{sub 4.6}Al{sub 0.4} based metal hydride beds of cylindrical configuration during desorption of hydrogen using a commercial software FLUENT 6.1.22. Temperature and concentration profiles at different radial locations, variation of average bed temperature and amount of hydrogen desorbed are presented at different hot fluid temperatures and bed thicknesses ranging from 30 to 50 C and 5 to 15 mm, respectively. The numerical results show that the dehydriding process for both the alloys depends on the temperature distribution in the metal hydride bed. At a given hot fluid temperature of 50 C, MmNi{sub 4.6}Fe{sub 0.4} and MmNi{sub 4.6}Al{sub 0.4} desorb the maximum hydrogen of about 1.11 and 1.28 wt%, respectively at the supply conditions of 30 bar and 25 C. The present computational results are also compared with the experimental data reported in the literature and a good agreement was found between the two. (author)

  18. Effects of periodicity on flow and dispersion through closely packed fixed beds of spheres

    Science.gov (United States)

    Reynolds, A. M.

    2002-02-01

    A lattice-Boltzmann formulation is used to investigate the effects of ``periodicity'' (geometry) on fluid flow and tracer-particle dispersion through fixed beds of spheres comprising of closely packed layers. In the ``period-1'' arrangement, spheres in the adjacent layers contact at their poles while the ``period-2'' and ``period-3'' arrangements correspond to hexagonal and faced-centered cubic close packing. For all three packing arrangements, there is a transition with increasing Reynolds number from a power law to a log-normal distribution of kinetic energies and, velocity and vorticity become more closely aligned giving rise to helical tracer-particle trajectories. It is suggested that these flow characteristics, unlike the stability of flow and the distribution of helicity, are largely insensitive to geometry, even when the geometry creates direct channels through the pack bed orientated along the gradient in applied pressure. For steady flows and strongly turbulent flows, such channels are predicted to provide direct routes for dispersion through a packed bed, while for weakly turbulent flows they influence dispersion primarily by destabilizing the flow and thereby promoting dispersion throughout a bed. The dispersion of tracer-particles released from a source located on or close to a ``stagnation streamline'' is predicted to be faster than ballistic in the near field and the transition to long-time Fickian diffusion is predicted to be distinguished by a regime of subdiffusion.

  19. Techniques of tumour bed boost irradiation in breast conserving therapy: Current evidence and suggested guidelines

    Energy Technology Data Exchange (ETDEWEB)

    Jalali, Rakesh; Singh, Suruchi; Budrukkar, Ashwini [Tata Memorial Hospital, Mumbai (India)

    2007-10-15

    Breast conservation surgery followed by external beam radiotherapy to breast has become the standard of care in management of early carcinoma breast. A boost to the tumour bed after whole breast radiotherapy is employed in view of the pattern of tumour bed recurrences in the index quadrant and was particularly considered in patients with some adverse histopathological characteristics such as positive margins, extensive intraductal carcinoma (EIC), lymphovascular invasion (LVI), etc. There is however, now, a conclusive evidence of improvement in local control rates after a boost radiotherapy dose in patients even without such factors and for all age groups. The maximum absolute reduction of local recurrences by the addition of boost is especially seen in young premenopausal patients. At the same time, the addition of boost is associated with increased risk of worsening of cosmesis and no clear cut survival advantage. Radiological modalities such as fluoroscopy, ultrasound and CT scan have aided in accurate delineation of tumour bed with increasing efficacy. A widespread application of these techniques might ultimately translate into improved local control with minimal cosmetic deficit. The present article discusses the role of radiotherapy boost and the means to delineate and deliver the same, identify the high risk group, optimal technique and the doses and fractionations to be used. It also discusses the extent of adverse cosmetic outcome after boost delivery, means to minimise it and relevance of tumour bed in present day scenario of advanced radiotherapy delivery techniques like (IMRT)

  20. Techniques of tumour bed boost irradiation in breast conserving therapy: Current evidence and suggested guidelines

    International Nuclear Information System (INIS)

    Breast conservation surgery followed by external beam radiotherapy to breast has become the standard of care in management of early carcinoma breast. A boost to the tumour bed after whole breast radiotherapy is employed in view of the pattern of tumour bed recurrences in the index quadrant and was particularly considered in patients with some adverse histopathological characteristics such as positive margins, extensive intraductal carcinoma (EIC), lymphovascular invasion (LVI), etc. There is however, now, a conclusive evidence of improvement in local control rates after a boost radiotherapy dose in patients even without such factors and for all age groups. The maximum absolute reduction of local recurrences by the addition of boost is especially seen in young premenopausal patients. At the same time, the addition of boost is associated with increased risk of worsening of cosmesis and no clear cut survival advantage. Radiological modalities such as fluoroscopy, ultrasound and CT scan have aided in accurate delineation of tumour bed with increasing efficacy. A widespread application of these techniques might ultimately translate into improved local control with minimal cosmetic deficit. The present article discusses the role of radiotherapy boost and the means to delineate and deliver the same, identify the high risk group, optimal technique and the doses and fractionations to be used. It also discusses the extent of adverse cosmetic outcome after boost delivery, means to minimise it and relevance of tumour bed in present day scenario of advanced radiotherapy delivery techniques like (IMRT)

  1. Process and Storage Quality of Quick Freezing Blueberries in LN2-spraying Fluidized Bed

    Directory of Open Access Journals (Sweden)

    Zhang Qinggang

    2014-07-01

    Full Text Available Liquid nitrogen spraying fluidized bed was used for Individual Quick Freezing (IQF of blue berries; processing technology and quality change of frozen samples during storage stage were analyzed in this study. Regular and mixed experimental design were used to confirm the quick freeze process of blueberries by means of setting different freezing temperature, wind velocity and the height of bed-layer. Multiple linear regression analysis indicates that the suitable process conditions for quick-freezing blueberries in LN2-spraying fluidized bed were -40°C freezing temperature, 4.5 m/sec wind speed and 3.6 cm bed height. Environmental Scanning Electron Microscopy (ESEM results show that the inner microstructure of the fluidized quick-frozen blueberries has better compactness, uniformity and destructiveness than that of the slow-frozen blueberries in -18°C refrigerator. Texture Analysis (TPA and the technology of image processing were used to analyze the different of blueberries in firmness and internal color between the fluidized quick-frozen and slow-frozen in -18°C refrigerator. The results show that the quality of the fluidized quick-frozen blueberries has better than that of the slow-frozen blueberries in -18°C refrigerator. The storage life of blueberry by LN2 spraying fluidized quick-frozen was confirmed that is around 150 days which in much better than that of the slow-frozen sample with the storage life of 100 days.

  2. FLUIDIZED BED STEAM REFORMING FOR TREATMENT AND IMMOBILIZATION OF LOW-ACTIVITY WASTE

    Energy Technology Data Exchange (ETDEWEB)

    HEWITT WM

    2011-04-08

    This report is one of four reports written to provide background information regarding immobilization technologies remaining under consideration for supplemental immobilization of Hanford's low-activity waste. This paper provides the reader a general understanding of fluidized bed steam reforming and its possible application to treat and immobilize Hanford low-activity waste.

  3. Evaluation of Heat Shields from RTS Wright Industries Magnesium and Uranium Beds

    CERN Document Server

    Korinko, P S

    2002-01-01

    Heat shields from a factory test of the furnaces that will be used to heat the magnesium and uranium beds for the tritium extraction facility (TEF) were examined to determine the cause of discoloration. The samples were examined using visual, optical microscopy, electron microscopy, x-ray spectroscopy, and Auger electron spectroscopy.

  4. Fluidized Bed Steam Reforming For Treatment And Immobilization Of Low-Activity Waste

    International Nuclear Information System (INIS)

    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.

  5. SWASH ZONE BED LEVEL CHANGES AND SEDIMENT ENTRAINMENT AT THE SURF-SWASH BOUNDARY

    DEFF Research Database (Denmark)

    Jensen, Stine Gro; Aagaard, Troels; Baldock, Tom

    2010-01-01

    detailed data on water levels and bed elevations in the swash zone. Water levels derived from the pressure transducers show that swash zone characteristics vary from the upper to lower swash. Using pressure transducers in the swash zone coupled with measurements of the hydrodynamics and sediment...

  6. Balance Analysis of Profit and Loss on Exploiting Coal-Bed Gas in China

    Institute of Scientific and Technical Information of China (English)

    肖建洪; 苗建国; 陈晓慧

    2001-01-01

    Models about four aspects according to the balance principle and practice in China were established, which involve the minimum production scale, alert production scale, safe running scale, and the goal production scale for specified profit level. It provides an effective quantitative analyzing method for the investors of coal-bed gas exploitation project.

  7. Characterization and CFD-modeling of the hydrodynamics of a prismatic spouted bed apparatus

    NARCIS (Netherlands)

    Gryczka, O.; Heinrich, S.; Deen, N.G.; Sint Annaland, van M.; Kuipers, J.A.M.; Jacob, M.; Mörl, L.

    2009-01-01

    Recently the importance of spouted bed technology has significantly increased in the context of drying processes as well as granulation, agglomeration or coating processes. However, the understanding of the complex interactions within and between the single phases is still low and needs further impr

  8. 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.

    OCM (Ocean Colour Monitor), covering the GoC region was digitally processed. False colour composites (FCC) of IRS-1C were generated and used to map coastal, near-shore geomorphic features and underwater flow-generated bed form structures. Suspended...

  9. ANALYSIS OF AN AEROBIC FLUIDIZED BED REACTOR DEGRADING MTBE AND BTEX AT REDUCED EBCTS

    Science.gov (United States)

    The purpose of this study was to investigate the biodegradation of MTBE and BTEX using a fluidized bed reactor (FBR) with granular activated carbon (GAC) as a biological attachment medium. Batch experiments were run to analyze the MTBE and TBA degradation kinetics of the culture ...

  10. The suspended sediment transport equation and its near-bed sediment flux

    Institute of Scientific and Technical Information of China (English)

    LI RuiJie; LUO Feng; ZHU WenJin

    2009-01-01

    The suspended sediment transport equation and its near-bed sediment flux are one of the key prob-lems of sediment transport research under nonequilibrium condition. Based on the three-dimensional primitive suspended transport equation, the two-dimensional suspended sediment transport equation is deduced. The derived process indicates that the physical essence of the near-bed sediment flux is right the bottom boundary condition for the suspended sediment transport equation. This paper ana-lyzes the internal relations between the two methods of sediment carrying capacity and shear stress in common use, points out the consistency of these two methods in terms of form and physical meaning, and unifies these two methods theoretically. Furthermore, based on the analysis and comparison of the expressions of the near-bed sediment flux, this paper summarizes some problems to which attention should be paid, thus offering a novel approach to the study and the solution of the problems of sus-pended sediment transport and exchange flux of near-bed water sediment.

  11. The definitive and intermediate hosts of Fasciola hepatica in the natural watercress beds in central France.

    Science.gov (United States)

    Rondelaud, D; Vignoles, P; Abrous, M; Dreyfuss, G

    2001-06-01

    Field investigations were carried out over a two-year period in 52 natural watercress beds located in the Limousin region of central France to list the mammal and bird species that frequented these sites. This enabled detection of the definitive hosts of Fasciola hepatica and determination of the prevalence of natural infection in snails. A total of 13 mammal and five bird species were listed in these watercress beds. Adult flukes were found in Lepus capensis (39.2%), Oryctolagus cuniculus (42.0%), and Sylvilagus floridanus (25.0%). No infection with F. hepatica was noted in the five species of rodents studied. Snails infected with F. hepatica were found in 14 watercress beds. The global prevalence of natural infection was 1.1% in Lymnaea truncatula and 0.3% in L. glabra. Among the other trematode larval forms detected, the most frequent was Haplometra cylindracea (0.5%). In the Limousin region, the presence of hares and rabbits in watercress beds ensured the continuation of the F. hepatica life cycle and permitted the subsequent infection of humans when this wild watercress was eaten. PMID:11411948

  12. The suspended sediment transport equation and its near-bed sediment flux

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    The suspended sediment transport equation and its near-bed sediment flux are one of the key problems of sediment transport research under nonequilibrium condition. Based on the three-dimensional primitive suspended transport equation, the two-dimensional suspended sediment transport equation is deduced. The derived process indicates that the physical essence of the near-bed sediment flux is right the bottom boundary condition for the suspended sediment transport equation. This paper analyzes the internal relations between the two methods of sediment carrying capacity and shear stress in common use, points out the consistency of these two methods in terms of form and physical meaning, and unifies these two methods theoretically. Furthermore, based on the analysis and comparison of the expressions of the near-bed sediment flux, this paper summarizes some problems to which attention should be paid, thus offering a novel approach to the study and the solution of the problems of suspended sediment transport and exchange flux of near-bed water sediment.

  13. A comparative analysis of two solid mixing models suitable for coal fluidized bed combustors and gasifiers

    Energy Technology Data Exchange (ETDEWEB)

    Abanades, J.C.; Atares, S.; Grasa, G.

    1999-07-01

    Rapid solid mixing is important to avoid undesirable temperature profiles in fluidized beds combustors and gasifiers. In this work, two alternative mathematical models for solid axial mixing are compared and their suitability for coal based fluidized beds is discussed. The two models: the Dispersion Model (May (1959)) and the Countercurrent Backmixing Model (van Deemter (1967)) were postulated early in the development of fluidized beds and both have been applied successfully despite their fundamental differences in conception. A numerical analysis investigating the convergence in the predictions of both models under practical conditions has been carried out. There is a wide area of practical interest in which both models are close (relative to typical experimental errors). Reasonable values for the bubble/slug parameters in the CCBM model are able to fit data where the dispersion model has been previously successful. This result has been confirmed with both their experimental data and other published works. The conclusion from this analysis is that the CCBM model is more reliable idealization in describing and scaling up solid mixing in coal based fluidized beds.

  14. Application of Moving Bed Biofilm Process for Biological Organics and Nutrients Removal from Municipal Wastewater

    Directory of Open Access Journals (Sweden)

    M. Kermani

    2008-01-01

    Full Text Available In this study, experiments have been conducted to evaluate the organics and nutrients removal from synthetic wastewater by a laboratory scale moving bed biofilm process. For nutrients removal, moving bed biofilm process has been applied in series with anaerobic, anoxic and aerobic units in four separate reactors. Moving bed biofilm reactors were operated continuously at different loading rates of nitrogen and Phosphorus. During optimum conditions, close to complete nitrification with average ammonium removal efficiency of 99.72% occurred in the aerobic reactor. In the aerobic reactor, the average specific nitrification rate was 1.8 g NOx-N kg VSS-1 h-1. The results of the average effluent soluble COD concentration from each reactor showed that denitrification process in the second anoxic reactor consumed most of the biodegradable organic matter. As seen from the results, denitrification rate has increased with increasing NOx-N loading in the second anoxic reactor. The aerobic phosphate removal rate showed a good correlation to the anaerobic phosphate release rate. Moreover, phosphate removal rate showed a strong correlation to the phosphate loading rate in the aerobic reactor. In optimum conditions, the average SCOD, total nitrogen and phosphorus removal efficiencies were 96.9, 84.6 and 95.8%, respectively. This study showed that the moving bed biofilm process could be used as an ideal and efficient option for the total nutrient removal from municipal wastewater.

  15. CORE ANALYSIS, DESIGN AND OPTIMIZATION OF A DEEP-BURN PEBBLE BED REACTOR

    Energy Technology Data Exchange (ETDEWEB)

    B. Boer; A. M. Ougouag

    2010-05-01

    Achieving a high burnup in the Deep-Burn pebble bed reactor design, while remaining within the limits for fuel temperature, power peaking and temperature reactivity feedback, is challenging. The high content of Pu and Minor Actinides in the Deep-Burn fuel significantly impacts the thermal neutron energy spectrum. This can result in power and temperature peaking in the pebble bed core in locally thermalized regions near the graphite reflectors. Furthermore, the interplay of the Pu resonances of the neutron absorption cross sections at low-lying energies can lead to a positive temperature reactivity coefficient for the graphite moderator at certain operating conditions. To investigate the aforementioned effects a code system using existing codes has been developed for neutronic, thermal-hydraulic and fuel depletion analysis of Deep-Burn pebble bed reactors. A core analysis of a Deep-Burn Pebble Bed Modular Reactor (400 MWth) design has been performed for two Deep-Burn fuel types and possible improvements of the design with regard to power peaking and temperature reactivity feedback are identified.

  16. SALT-4, Temperature and Stress from Radioactive Waste Disposal in Bedded Salts

    International Nuclear Information System (INIS)

    1 - Description of program or function: SALT4 is a two-dimensional, analytical/displacement-discontinuity code designed to evaluate temperatures, deformation, and stresses associated with underground disposal of radioactive waste in bedded salt. SALT4 takes into account viscoelastic behavior in the pillars adjacent to excavations, transversely isotropic elastic moduli such as those exhibited by bedded or stratified rock, and excavation sequence. SALT4 can be used for parameter sensitivity analyses of two-dimensional, repository-scale, thermal and thermomechanical response in bedded salt during the excavation, operational, and post-closure phases. It is especially useful in evaluating alternative patterns and sequences of excavation or waste canister placement. 2 - Method of solution: In SALT4, the temperature distribution and associated thermal stresses are approximated by analytic solutions for a line heat source in an elastic medium. The mechanical effects due to excavation of the repository openings are treated by the displacement-discontinuity method. 3 - Restrictions on the complexity of the problem: Although SALT4 was designed for analysis of bedded salt, it is also applicable to crystalline rock if the creep calculation is suppressed. The main disadvantage of SALT4 is that some of the assumptions made, i.e. temperature-independent material properties, render it unsuitable for canister-scale analysis or analysis of lateral deformation of the pillars

  17. Recycling manure as cow bedding: Potential benefits and risks for UK dairy farms.

    Science.gov (United States)

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

    2015-11-01

    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 anecdotal claims of improved cow comfort. Among animal health risks, only udder health has received appreciable attention. There are some circumstantial reports of difficulties of maintaining udder health on RMS, but no large scale or long term studies of effects on clinical and subclinical mastitis have been published. Existing reports do not give consistent evidence of inevitable problems, nor is there any information on clinical implications for other diseases. The scientific basis for guidelines on management of RMS bedding is limited. Decisions on optimum treatment and management may present conflicts between controls of different groups of organisms. There is no information on the influence that such 'recycling' of manure may have on pathogen virulence. The possibility of influence on genetic material conveying antimicrobial resistance is a concern, but little understood. Should UK or other non-US farmers adopt RMS, they are advised to do so with caution, apply the required strategies for risk mitigation, maintain strict hygiene of bed management and milking practices and closely monitor the effects on herd health. PMID:26388545

  18. Mapping seagrass beds and coral reefs in the coastal region of Vietnam using VNREDSAT-1 data

    Science.gov (United States)

    Lau, K. V.; Chen, C. F.; Nguyen, S. T.; Chen, C. R.; Tong Phuoc, H. S.; Nguyen, H. H.

    2015-12-01

    Seagrass beds and coral reefs are two important ecosystems in the coastal zone. They play an important role to protect and shelter various marine organisms. Both seagrass beds and coral reefs could prevent the coastline from erosion. While seagrass stabilizes sediments and acts as a biofilter, coral reefs can control carbon dioxide in the ocean water. Besides, seagrass also provides direct food for many fish and marine animals. Therefore, mapping seagrass beds and coral reefs is very important for coastal management and conservation. In May 2013, Vietnam launched the first satellite for earth observations, called Vietnam Natural Resources, Environment and Disaster Monitoring Satellite (VNREDSAT-1). It is a great opportunity for environmental monitoring in the country using the data from this satellite. The objective of this study is to use the VNREDSAT-1 data to map seagrass beds and coral reefs in the coastal region of Ninh Hai district, Ninh Thuan province, Vietnam, where the seagrass still remains in good a condition. We processed the VNREDSAT-1 image through four steps: (1) Atmospheric correction using Second Simulation of the Satellite Signal in the Solar Spectrum radiative transfer model (6S), (2) Sun glint removal by using Hedley method, (3) Water column correction using the depth-variant index (DII) proposed by Lyzenga, and (4) Image classification using the maximum likelihood algorithm. The mapping results verified with the ground reference data showed a good overall accuracy of 75% and Kappa coefficient of 0.7. The total area of seagrass beds was approximately 323.09 ha, which mainly distributed in My Hoa and Thai An villages. The total area of coral reefs was approximately 564.42 ha, located along the coast and on outer area to seagrass and shoreline reefs. This study demonstrates the applicability of VNREDSAT-1 for underwater habitat monitoring. The results could be useful for natural resources managers to devise strategies for management and

  19. Plasma volume and biochemical changes in athletes during bed rest chronic hyperhydration

    Science.gov (United States)

    Zorbas, Yan G.; Yarullin, Vladimir L.; Denogradov, Sergei D.; Afonin, Victor B.

    Daily fluid and salt supplements (FSS) may be used to reduce plasma biochemical changes during bed rest (BR). The aim of this study was to evaluate the effect of a daily intake of FSS on plasma volume (PV) and biochemical changes during BR. Studies were done during a pre BR period of 15 days and during a BR period of 30 days. Thirty male athletes aged 22-26 years were chosen as subjects. They were divided into three groups: unsupplemented ambulatory control subjects (UACS), unsupplemented bed rested subjects (UBRS) and supplemented bed rested subjects (SBRS). The UBRS and SBRS were kept under a rigorous bed rest regime for 30 days. The SBRS took 26 ml water/kg body weight and 0.1 g sodium chloride/kg body weight daily. PV, protein, albumin, sodium (Na), Chloride (Cl), potassium (K), osmolality, creatinine, glucose, and whole blood haematocrit (Hct) and haemoglobin (Hb) concentrations were measured. PV increased significantly ( P≤0.01) while plasma protein, albumin, Na, Cl, K, glucose, creatinine, osmolality, and whole blood Hb and Hct concentration decreased significantly ( P≤0.01) in the SBRS group when compared with the UBRS group. By contrast, PV decreased significantly ( P≤0.01), while plasma protein, albumin, Na, Cl, K, glucose, creatinine, osmolality and whole blood Hct and Hb concentration increased significantly ( P≤0.01) in the UBRS group when compared with the SBRS and UACS groups. The measured parameters did not change significantly in the UACS group when compared with the baseline control values. It was concluded that a daily intake of FSS may be used to attenuate PV losses and biochemical changes in endurance trained athletes during bed rest.

  20. Bed net use and associated factors in a rice farming community in Central Kenya

    Directory of Open Access Journals (Sweden)

    Kabuage Lucy

    2009-04-01

    Full Text Available Abstract Background Use of insecticide-treated nets (ITNs continues to offer potential strategy for malaria prevention in endemic areas. However their effectiveness, sustainability and massive scale up remain a factor of socio-economic and cultural variables of the local community which are indispensable during design and implementation stages. Methods An ethnographic household survey was conducted in four study villages which were purposefully selected to represent socio-economic and geographical diversity. In total, 400 households were randomly selected from the four study villages. Quantitative and qualitative information of the respondents were collected by use of semi-structured questionnaires and focus group discussions. Results Malaria was reported the most frequently occurring disease in the area (93% and its aetiology was attributed to other non-biomedical causes like stagnant water (16%, and long rains (13%. Factors which significantly caused variation in bed net use were occupant relationship to household head (χ2 = 105.705; df 14; P = 0.000, Age (χ2 = 74.483; df 14; P = 0.000, village (χ2 = 150.325; df 6; P = 0.000, occupation (χ2 = 7.955; df 3; P = 0.047, gender (χ2 = 4.254; df 1; P = 0.039 and education levels of the household head or spouse (χ2 = 33.622; df 6; P = 0.000. The same variables determined access and conditions of bed nets at household level. Protection against mosquito bite (95% was the main reason cited for using bed nets in most households while protection against malaria came second (54%. Colour, shape and affordability were some of the key potential factors which determined choice, use and acceptance of bed nets in the study area. Conclusion The study highlights potential social and economic variables important for effective and sustainable implementation of bed nets-related programmes in Sub-Saharan Africa.

  1. Model description and kinetic parameter analysis of MTBE biodegradation in a packed bed reactor

    DEFF Research Database (Denmark)

    Waul, Christopher Kevin; Arvin, Erik; Schmidt, Jens Ejbye

    2008-01-01

    A dynamic modeling approach was used to estimate in-situ model parameters, which describe the degradation of methyl tert-butyl ether (MTBE) in a laboratory packed bed reactor. The measured dynamic response of MTBE pulses injected at the reactor's inlet was analyzed by least squares and parameter ...

  2. Evaluation of Sleeping Comfort of Bed Mattresses using Physiological and Psychological Response Measurements

    Science.gov (United States)

    Aoi, Masataka; Kamijo, Masayoshi; Yoshida, Hiroaki

    The purpose of this study is to create a method of evaluating the quality of sleep based on the elastic properties of bed mattresses through measurement of physiological and psychological responses while sleeping. We gathered Profile of Mood States (POMS) results before and after sleep, and investigated changes in subjects' moods according to sleep. A total of 4 bed mattresses with different degrees of elasticity were prepared. They were all pocket coil mattresses. We conducted polysomnography (PSG) testing on subjects with a bioamplifier while they slept in each bed mattress, so that sleeping depth indicating the quality of sleep could be estimated. PSG is a comprehensive recording of the biophysiological changes that occur during sleep. As a result, the sleep depth of bed mattress with a high degree of elasticity increased in the PSG evaluation. Because the hip sinks in deeply from the waist, it is not easy to turn over on mattresses with a low degree of elasticity. We have therefore considered that the sleep depth of the subjects became shallow as a result. We have concluded that it is possible to estimate the quality of sleep through analysis of PSG and POMS results.

  3. Sage-Grouse and Coal-Bed Methane: Can They Coexist within the Powder River Basin?

    Science.gov (United States)

    Duncan, Michael B.

    2010-01-01

    Concerns are growing regarding the availability of sustainable energy sources due to a rapidly growing human population and a better understanding of climate change. In recent years, the United States has focused much attention on developing domestic energy sources, which include coal-bed methane (CBM). There are vast deposits of the natural gas…

  4. 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

    .1), respectively. Plasma concentrations of adrenaline, noradrenaline, renin and aldosterone were increased, as measured in the supine position. No significant differences were found between the two groups. Plasma concentrations of antidiuretic hormone were within normal limits. In conclusion, continuous bed rest...

  5. Study of fluidized bed boiler system based on experiments and simulation

    OpenAIRE

    Бугаєва, Людмила Миколаївна; Серебрянський, Дмитро Олександрович; Дейкун, Артем Андрійович

    2012-01-01

    The paper considers the process of burning solid fuel in boilers with a low boiling layer. The results of calculations of the basic regime characteristics of the fluid bed are given. The results of aerodynamic simulation and the distribution of solid particles in firebox are presented

  6. Conceptual design of a fluidized bed nuclear reactor: statics, dynamics and safety-related aspects

    NARCIS (Netherlands)

    Agung, A.

    2007-01-01

    In this thesis a conceptual design of an innovative high temperature reactor based on the fluidization principle (FLUBER) is proposed. The reactor should satisfy the following requirements: (a) modular and low power, (b)) large shutdown margin, (c) able to produce power when the bed of particles exp

  7. Sediment modification by seagrass beds: Muddification and sandification induced by plant cover and environmental conditions

    Science.gov (United States)

    van Katwijk, M. M.; Bos, A. R.; Hermus, D. C. R.; Suykerbuyk, W.

    2010-09-01

    Seagrasses are well-known ecosystem engineers. They reduce water dynamics and sediment resuspension, and trap fine sediments. However, exceptions of this paradigm have been reported. To test whether these exceptions could be related to plant cover and environmental conditions, we investigated sediment modification under influence of seagrass presence in various annual eelgrass ( Zostera marina) beds with varying plant cover and sediment composition. At the relatively wave-exposed, sandy sites, dense vegetation caused muddification (increase in fine sediments and organic content) of the sediments. Sparse vegetation (seagrass performance. Muddification may increase the nutrient input and, depending on the nutrient status of the system, either stimulate or reduce seagrass development. Similarly, sandification may postpone and even prevent extinction of seagrass beds when it occurs in areas that may have become too muddy for seagrass growth.

  8. The Ontogeny of Diurnal Rhythmicity in Bed-Sharing and Solitary-Sleeping Infants: A Preliminary Report

    Science.gov (United States)

    Burnham, Melissa M.

    2007-01-01

    The purpose of the current study was to investigate the development of sleep-wake and melatonin diurnal rhythms over the first 3 months of life, and the potential effect of bed-sharing on their development. It was hypothesized that increased maternal contact through bed-sharing would affect the development of rhythms in human infants. Ten…

  9. Cleaning and Heat Transfer in Heat Exchanger with Circulating Fluidized Beds

    Science.gov (United States)

    Kang, Ho Keun; Ahn, Soo Whan; Choi, Jong Woong; Lee, Byung Chang

    2010-06-01

    Fluidized bed type heat exchangers are known to increase the heat transfer and prevent the fouling. For proper design of circulating fluidized bed heat exchanger it is important to know the effect of design and operating parameters on the bed to the wall heat transfer coefficient. The present experimental and numerical study was conducted to investigate the effects of circulating solid particles on the characteristics of fluid flow, heat transfer and cleaning effect in the fluidized bed vertical shell and tube type heat exchanger with counterflow, at which a variety of solid particles such as glass (3 mmF), aluminum (2˜3 mmF), steel (2˜2.5 mmF), copper (2.5 mmF) and sand (2˜4 mmF) were used in the fluidized bed with a smooth tube. Seven different solid particles have the same volume, and the effects of various parameters such as water flow rates, particle diameter, materials and geometry were investigated. The present experimental and numerical results showed that the flow velocity range for collision of particles to the tube wall was higher with heavier density solid particles, and the increase in heat transfer was in the order of sand, copper, steel, aluminum, and glass. This behaviour might be attributed to the parameters such as surface roughness or particle heat capacity. Fouling examination using 25,500 ppm of ferric oxide (Fe2O3) revealed that the tube inside wall is cleaned by a mild and continuous scouring action of fluidized solid particles. The fluidized solid particles not only keep the surface clean, but they also break up the boundary layer improving the heat transfer coefficient even at low fluid velocities.

  10. Humidity and Cage and Bedding Temperatures in Unoccupied Static Mouse Caging after Steam Sterilization

    OpenAIRE

    Ward, Gina M; Cole, Kelly; Faerber, Jennifer; Hankenson, F Claire

    2009-01-01

    Contemporary rodent caging and equipment often are sterilized by steam autoclaves prior to use in facilities. This work assessed the microenvironment of unoccupied static mouse cages after steam sterilization to determine when internal temperatures had cooled to levels appropriate for rodent housing. Polycarbonate static cages containing food and corncob bedding were stacked (10 rows × 7 columns) in duplicate (front and back; n = 140 cages) on a storage truck and autoclaved to 249 °F (121 °C)...

  11. Design of a bed load and driftwood filtering dam, analysis of the phenomena and hydraulic design

    OpenAIRE

    Schleiss, Anton; Speerli, J.; Pfammatter, Roger; Bianco-Riccioz, Manuella; Bianco, Philippe; De Cesare, Giovanni

    2014-01-01

    Flood protection often calls on to the realization of retention works for bed load as well as wood and debris flow. Certain relatively recent arrangements did not perform according to their intended function, what shows the complexity of the design and the implementation of such works. Adaptations were necessary to reach the security objectives. The design of a retention dam for solid materials and floating driftwood requires the consideration of numerous hydraulic and material transport proc...

  12. Lake bed environments, modern sedimentation and the glacial and post-glacial history of Windermere, UK

    OpenAIRE

    Miller, Helen

    2014-01-01

    Windermere, the largest natural lake in England, is a glacial ribbon lake located in the southeast of the Lake District. High resolution geophysical datasets, combined with sediment analysis, geomorphological mapping and historical research have been used to investigate the lake bed environments, recent sediment record of pollution and glacial and post-glacial history of the lake and surrounding catchment. The data are used to generate a present-day landscape map of Windermere, revealing...

  13. Examining time trends in the Oldowan technology at Beds I and II, Olduvai Gorge.

    Science.gov (United States)

    Kimura, Yuki

    2002-09-01

    The lithic analysis of the Bed I and II assemblages from Olduvai Gorge reveals both static and dynamic time trends in early hominids' technology from 1.8 to 1.2 m.y.a. The Bed I Oldowan (1.87-1.75 m.y.a.) is characterized by the least effort strategy in terms of raw material exploitation and tool production. The inclusion of new raw material, chert, for toolmaking in the following Developed Oldowan A (DOA, 1.65-1.53 m.y.a.) facilitated more distinctive and variable flaking strategies depending on the kind of raw materials. The unique characters of DOA are explainable by this raw material factor, rather than technological development of hominids. The disappearance of chert in the subsequent Developed Oldowan B and Acheulian (1.53-1.2 m.y.a.) necessitated a shift in tool production strategy more similar to that of Bed I Oldowan than DOA. However, the evidence suggests that Bed II hominids might have been more skillful toolmakers, intensive tool-users, and engaged in more active transport of stone tools than the Bed I predecessors. Koobi Fora hominids maintained a more static tool-using behavior than their Olduvai counterparts due mainly to a stable supply of raw materials. They differed from Olduvai hominids in terms of less battering of cores, consistent transport behavior, and few productions of side-struck flakes, indicating a regional variation of toolmaking and using practice. However, they shared with Olduvai hominids a temporal trend toward the production of larger flakes from larger cores after 1.6 m.y.a. Increased intake of animal resources and the expansion of ranging area of Homo ergaster would have led to the development of technological organization. Technological changes in the Oldowan industry are attested at Olduvai Gorge, Koobi Fora, and Sterkfontein, suggesting that it was a pan-African synchronous phenomenon, beginning at 1.5 m.y.a. PMID:12234546

  14. Scour around a submerged cylinder and marine hydrokinetic (MHK) device in live-bed conditions

    Science.gov (United States)

    Beninati, Maria Laura; Volpe, Michael; Krane, Michael; Fontaine, Arnold

    2013-11-01

    Experiments are presented to explore how sediment scour around a single Marine Hydrokinetic (MHK) turbine varies with flow speed. Three Reynolds numbers, based on support structure diameter were used to induce live-bed scour conditions. Based on results from previous studies on submerged cylinders, differences in scour patterns between a single cylinder and MHK device can be determined. In the case of MHK energy, many devices are submerged in the flow. Thus, it is important to analyze the impact of both the support structure and the addition of the rotating blades. The experiments were performed in the small-scale testing platform in the hydraulic flume facility at Bucknell University. For each test case, bed form topology was measured after a three-hour time interval using a traversing two-dimensional bed profiler. During the experiment, scour depth measurements at the front face of the cylindrical support structure were taken to estimate the scour rate. Measurements of the bed form were taken across the width of the test section. Results show that the scour hole dimensions increase in the presence of the MHK device. These dimensions also increase with increasing Reynolds number.

  15. Coolability of a 3D homogeneous debris bed, experimental and numerical investigations

    International Nuclear Information System (INIS)

    Within the framework of nuclear safety analysis, we present here experimental and numerical results in the field of debris bed coolability. Experimental data are provided by the SILFIDE 3D experimental facility in which the debris bed is heated by induction, at Electricite de France (EDF). Numerical computations are obtained with MC3D-REPO which is a 3-phase and 3D code developed by the Commissariat a l'Energie Atomique (CEA). The uniform debris bed consists of 2 and 3,17 mm diameter steel beads contained in a 50 cm x 60 cm x 10 cm vessel. Water is used as a coolant and can be introduced either by the top or the bottom of the bed at a determined temperature. Due to heterogeneous power distribution within the bed, two definitions for the critical heat flux are proposed: the classical mean value and the local flux (much higher). Even in the first case, the measured dryout heat flux is higher than the Lipinsky 1-D flux. Temperature curve analyses show that the dryout phenomenon is very local, therefore one should be careful about the right flux definition to use. As the injected power is being increased stepwise, steady temperature stages above saturation temperature before dryout can be observed. A discussion is proposed. For some very high values of the induction power, some spheres melted together, leading to a bigger non-porous region. Even if the local temperature went over 1300 C, the bed was still coolable and the critical heat flux value was not impacted. Some parametric studies led to the following conclusions: bottom coolant injection leads to a twice time higher critical flux than by top injection, the influence of the height of the water pool above debris bed is negligible, a sub-cooled liquid injection has no influence on the coolability. Fluidization of surface particles is also discussed. The MC3D-REPO model assumes a thermal equilibrium between the three phases, which gives results in agreement with experiments until dryout occurs. (author)

  16. Bedmap2: improved ice bed, surface and thickness datasets for Antarctica

    Directory of Open Access Journals (Sweden)

    P. Fretwell

    2012-10-01

    Full Text Available We present Bedmap2, a new suite of gridded products describing surface elevation, ice-thickness and the seafloor and subglacial bed elevation of the Antarctic south of 60° S. We derived these products using data from a variety of sources, including many substantial surveys completed since the original Bedmap compilation (Bedmap1 in 2001. In particular, the Bedmap2 ice thickness grid is made from 25 million measurements, over two orders of magnitude more than were used in Bedmap1. In most parts of Antarctica the subglacial landscape is visible in much greater detail than was previously available and the improved coverage of data has in many areas revealed the full scale of mountain ranges, valleys, basins and troughs, only fragments of which were previously indicated in local surveys. The derived statistics for Bedmap2 show that the volume of ice contained in the Antarctic ice sheet (27 million km3 and its potential contribution to sea-level rise (58 m are similar to those of Bedmap1, but the mean thickness of the ice sheet is 4.6 % greater, the mean depth of the bed beneath the grounded ice sheet is 72 m lower and the area of ice sheet grounded on bed below sea level is increased by 10 %. The Bedmap2 compilation highlights several areas beneath the ice sheet where the bed elevation is substantially lower than the deepest bed indicated by Bedmap1. These products, along with grids of data coverage and uncertainty, provide new opportunities for detailed modelling of the past and future evolution of the Antarctic ice sheets.

  17. Bedmap2: improved ice bed, surface and thickness datasets for Antarctica

    Directory of Open Access Journals (Sweden)

    P. Fretwell

    2013-02-01

    Full Text Available We present Bedmap2, a new suite of gridded products describing surface elevation, ice-thickness and the seafloor and subglacial bed elevation of the Antarctic south of 60° S. We derived these products using data from a variety of sources, including many substantial surveys completed since the original Bedmap compilation (Bedmap1 in 2001. In particular, the Bedmap2 ice thickness grid is made from 25 million measurements, over two orders of magnitude more than were used in Bedmap1. In most parts of Antarctica the subglacial landscape is visible in much greater detail than was previously available and the improved data-coverage has in many areas revealed the full scale of mountain ranges, valleys, basins and troughs, only fragments of which were previously indicated in local surveys. The derived statistics for Bedmap2 show that the volume of ice contained in the Antarctic ice sheet (27 million km3 and its potential contribution to sea-level rise (58 m are similar to those of Bedmap1, but the mean thickness of the ice sheet is 4.6% greater, the mean depth of the bed beneath the grounded ice sheet is 72 m lower and the area of ice sheet grounded on bed below sea level is increased by 10%. The Bedmap2 compilation highlights several areas beneath the ice sheet where the bed elevation is substantially lower than the deepest bed indicated by Bedmap1. These products, along with grids of data coverage and uncertainty, provide new opportunities for detailed modelling of the past and future evolution of the Antarctic ice sheets.

  18. Two-stage dual fluidized bed gasification: Its conception and application to biomass

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Guangwen [Research Laboratory, IHI Corporation, Ltd., Isogo-Ku, Yokohama 235-8501 (Japan); Institute of Process Engineering, Chinese Academy of Sciences, Haidian, Beijing 100080 (China); Murakami, Takahiro [Research Laboratory, IHI Corporation, Ltd., Isogo-Ku, Yokohama 235-8501 (Japan); Clean Gas Group, National Institute of Advanced Science and Technology, Tsukuba, Ibaraki 305-8569 (Japan); Suda, Toshiyuki; Matsuzaw, Yoshiaki; Tani, Hidehisa [Research Laboratory, IHI Corporation, Ltd., Isogo-Ku, Yokohama 235-8501 (Japan)

    2009-01-15

    The quoted two-stage dual fluidized bed gasification (T-DFBG) devises the use of a two-stage fluidized bed (TFB) to replace the single-stage bubbling fluidized bed gasifier involved in the normally encountered dual fluidized bed gasification (N-DFBG) systems. By feeding fuel into the lower stage of the TFB, this lower stage functions as a fuel gasifier similar to that in the N-DFBG so that the upper stage of the TFB works to upgrade the produced gas in the lower stage and meanwhile to suppress the possible elutriation of fuel particles fed into the freeboard of the lower-stage bed. The heat carrier particles (HCPs) circulated from the char combustor enter first the upper stage of the TFB to facilitate the gas upgrading reactions occurring therein, and the particles are in turn forwarded into the lower stage to provide endothermic heat for fuel pyrolysis and gasification reactions. Consequently, with T-DFBG it is hopeful to increase gasification efficiency and decrease tar content in the produced gas. This anticipation was corroborated through gasifying dry coffee grounds in two 5.0kg/h experimental setups configured according to the principles of T-DFBG and N-DFBG, respectively. In comparison with the N-DFBG case, the test according to T-DFBG increased, the fuel C conversion and cold gas efficiency by about 7% and decreased tar content in the produced gas by up to 25% under similar reaction conditions. Test results demonstrated also that all these upgrading effects via adopting T-DFBG were more pronounced when a Ca-based additive was blended into the fuel. (author)

  19. Palaeogeography of Late Triassic red-beds in Singapore and the Indosinian Orogeny

    Science.gov (United States)

    Oliver, Grahame; Prave, Anthony

    2013-10-01

    A red-bed facies of the Upper Triassic Jurong Formation has been logged on Sentosa Island, Singapore. An overall coarsening and thickening-upward pattern is well developed. The lower part of the section is dominated by purple-red, massive to finely laminated illite-smectite-kaolin-rich mudstones containing thin, discontinuous lenses of fine sandstone marked by low-angle lamination and small ripples. One dinosaur-like foot print has been discovered in a loose block of red mudstone. It is concluded that this is a lacustrine sequence and it is proposed to name the lake, Lake Sentosa. The upper part of the sequence consists of flat-laminated to trough cross-bedded medium-grained sandstone and granule to cobble conglomerates alternating with purple-red mudstone. The mudstone-sandstone packages are arranged in decametre-scale coarsening-upward cycles. The channelling and decimetre-scale cross-bedding characterising the sandstone and conglomeratic beds is evidence for deposition by flashy fluvial flood processes, possibly feeding into the lake as a fresh water delta. One possible dinosaur trackway in granule size conglomerate has been located. Detrital zircon U-Pb ages vary from 2.7 Ba to 209 Ma with significant populations at ˜245 Ma and 220 Ma. These ages throw light on the timing of the Indosinian Orogeny. The molasse red-beds of the Jurong Formation were deposited in a half graben formed in the hangingwall of the Bukit Timah Fault when central Peninsular Malaysia went into extension following the climax of the Indosinian Orogeny in the Late Triassic.

  20. Optimizing fumigation efficiency by doubling drip line number and using low permeability film in raised-bed production systems

    Science.gov (United States)

    Southern California strawberries are planted in raised-beds covered by polyethylene (PE) film and typically are irrigated with two drip lines placed near the bed surface. To control soil-borne pests, fumigants are commonly applied through the drip lines prior to transplanting strawberries, but effic...