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Sample records for hydraulic ram effects

  1. Cradle modification for hydraulic ram

    International Nuclear Information System (INIS)

    Koons, B.M.

    1995-01-01

    The analysis of the cradle hydraulic system considers stress, weld strength, and hydraulic forces required to lift and support the cradle/pump assembly. The stress and weld strength of the cradle modifications is evaluated to ensure that they meet the requirements of the American Institute for Steel Construction (AISC 1989). The hydraulic forces are evaluated to ensure that the hydraulic system is capable of rotating the cradle and pump assembly to the vertical position (between 70 degrees and 90 degrees)

  2. Effect of Non-linear Velocity Loss Changes in Pumping Stage of Hydraulic Ram Pumps on Pumping Discharge Rate

    Directory of Open Access Journals (Sweden)

    Reza Fatahialkouhi

    2018-03-01

    Full Text Available The ram pump is a device which pumps a portion of input discharge to the pumping system in a significant height by using renewable energy of water hammer. The complexities of flow hydraulic on one hand and on the other hand the use of simplifying assumptions in ram pumps have caused errors in submitted analytical models for analyzing running cycle of these pumps. In this study it has been tried to modify the governing analytical model on hydraulic performance of these pumps in pumping stage. In this study by creating a logical division, the cycle of the ram pump was divided into three stages of acceleration, pumping and recoil and the governing equations on each stage of cycling are presented by using method of characteristics. Since the closing of impulse valve is nonlinear, velocity loss in pumping stage is considered nonlinearly. Also the governing equations in pumping stage were modified by considering disc elasticity of impulse valve and changing volume of the pump body when the water hammer phenomenon is occurred. In order to evaluate results and determine empirical factors of the proposed analytical model, a physical model of the ram pump is made with internal diameter of 51 mm. Results of this study are divided into several parts. In the first part, loss coefficients of the impulse valve were measured experimentally and empirical equations of drag coefficient and friction coefficient of the impulse valve were submitted by using nonlinear regression. In the second part, results were evaluated by using experimental data taken from this study. Evaluation of statistical error functions showed that the proposed model has good accuracy for predicting experimental observations. In the third part, in order to validate the results in pumping stage, the analytical models of Lansford and Dugan (1941 and Tacke (1988 were used and the error functions resulted from prediction of experimental observations were investigated through analytical models of

  3. Hydraulic ram analysis = Analyse du bélier hydraulique

    NARCIS (Netherlands)

    Verspuy, C.; Tijsseling, A.S.

    1993-01-01

    A simple mathematical model describing the operation of a hydraulic ram is presented. Predictions of the model are compared with measurements done in an earlier stage of the project. The model is used to perform a parameter variation study.

  4. Design and analysis of hydraulic ram water pumping system

    Science.gov (United States)

    Hussin, N. S. M.; Gamil, S. A.; Amin, N. A. M.; Safar, M. J. A.; Majid, M. S. A.; Kazim, M. N. F. M.; Nasir, N. F. M.

    2017-10-01

    The current pumping system (DC water pump) for agriculture is powered by household electricity, therefore, the cost of electricity will be increased due to the higher electricity consumption. In addition, the water needs to be supplied at different height of trees and different places that are far from the water source. The existing DC water pump can pump the water to 1.5 m height but it cost money for electrical source. The hydraulic ram is a mechanical water pump that suitable used for agriculture purpose. It can be a good substitute for DC water pump in agriculture use. The hydraulic ram water pumping system has ability to pump water using gravitational energy or the kinetic energy through flowing source of water. This project aims to analyze and develop the water ram pump in order to meet the desired delivery head up to 3 meter height with less operation cost. The hydraulic ram is designed using CATIA software. Simulation work has been done using ANSYS CFX software to validate the working concept. There are three design were tested in the experiment study. The best design reached target head of 3 m with 15% efficiency and flow rate of 11.82l/min. The results from this study show that the less diameter of pressure chamber and higher supply head will create higher pressure.

  5. Software for dimensioning of hydraulic ram; Software para dimensionamento de carneiro hidraulico

    Energy Technology Data Exchange (ETDEWEB)

    Borges Neto, Manuel Rangel [Centro Federal de Educacao Tecnologica de Petrolina, CE (Brazil); Borges, Grace Anne Pontes [Faculdade de Tecnologia de Sao Paulo (FATEC), Sao Paulo, SP (Brazil). Dept. de Processamento de Dados; Borges, Everton Pontes [Centro Federal de Educacao Tecnologica do Rio Grande do Norte, Natal, RN (Brazil). Curso Tecnologia em Automacao Industrial

    2004-07-01

    The search for new renewable energy sources sometimes takes us always from existing solutions applications. The hydraulic ram is equipment developed in 1796, used to water pumping, without using electricity energy and can be used for small rural producer in places where the conventional electricity grid access is limited. The objective of this work is Software introducing, developed to help a commercial hydraulic ram dimensioning, which isn't necessary previous hydraulic knowledge, and can also be used as a didactic resource at technicians and technologists courses in subjects as hydraulics or irrigation. (author)

  6. Quasi-open loop hydraulic ram incremental actuator with power conserving properties

    International Nuclear Information System (INIS)

    Raymond, E.T.; Robinson, C.W.

    1982-01-01

    An electric stepping motor, operated by command signals from a computer or a microprocessor, rotates a rotary control member of a distributor valve, for sequencing hydraulic pressure and hence flow to the cylinders of an axial piston hydraulic machine. A group of the cylinders are subjected to pressure and flow and the remaining cylinders are vented to a return line. Rotation of the rotary control valve member sequences pressurization by progressively adding a cylinder to the forward edge to the pressurized group and removing a cylinder from the trailing edge of the pressurized group. The double ended pistons of each new pressurized group function to drive a wobble plate into a new position of equilibrium and then hold it in such position until another change in the makeup of the pressurized group. These pistons also displace hydraulic fluid from the opposite cylinder head which serves as the output of a pumping element. An increment of displacement of the wobble plate occurs in direct response to each command pulse that is received by the stepping motor. Wobble plate displacement drives the rotary valve of the hydraulic power transfer unit, causing it to transfer hydraulic fluid from a first expansible chamber on one side of a piston in a hydraulic ram to a second expansible chamber on the opposite side of the piston. Reverse drive of the hydraulic power transfer unit reverses the direction of transfer of hydraulic fluid between the two expansible chambers

  7. Effect of breed and age on sexual behaviour of rams.

    Science.gov (United States)

    Simitzis, Panagiotis E; Deligeorgis, Stelios G; Bizelis, Joseph A

    2006-05-01

    The objective of this study was to highlight the problems that arise during the reproduction between thin-tailed rams and fat-tailed ewes. At the same time, particular emphasis laid on the influence of sheep breed, sheep age, time after ram introduction and day of the ewe estrus cycle on ram and ewe sexual behaviour. Rams were subjected to sexual performance tests by being individually exposed to 12 ewes for 3 h daily, 19 consecutive days. The 16 rams of the experiment were separated according to their age (9 and 21 months old) and breed (Chios and Karagouniki), and the 96 ewes of Chios fat-tailed breed, were divided by age (9 and 21 months old). The main characteristics of courtship behaviour, like sniffing, nudging, flehmen response and following were recorded and studied in detail. Mature Chios rams, which were the only one with previous experience of Chios ewes, exhibited higher rates of sexual interest per ewe than the other rams (P nudged more young than mature ewes (P behaviour when they courted with Chios fat-tailed ewes in comparison with Chios rams (P behaviour components decreased (P < 0.001). Finally, the effect of the day of the experiment was only significant in the case of sniffing, which increased during the first 2 days and then declined and stabilized (P < 0.01). As it was demonstrated, ram age and ram breed played a fundamental role in the exhibition of sexual interest elements.

  8. Fire effects in Pinus uncinata Ram plantations

    Directory of Open Access Journals (Sweden)

    Adrián Cardil Forradellas

    2016-04-01

    Full Text Available Aim of study: Understanding fire ecology of main forest species is essential for a sound, scientifically based on managing of wildlands and also to assess likely implications due to changes in fire regime under a global change scenario. Few references can be found about fire ecology of Pinus uncinata Ram. (PU. PU species grows in the Central Pyrenees where large, severe wildland fires did not occur frequently in the past. However, several fires with extreme fire behavior have affected PU stands in last years and they might disturb other PU forest in the future.Area of study: Cabdella fire (February 2012, in Lleida province, is one of the several wildland fires occurred in 2012 (winter season in the Central Pyrenees. Fire affected a large PU plantation (102 ha located at 1.800-2,100 meters above the sea.Material and methods: We have analyzed first order fire effects in three fireline intensity thresholds along three years in terms of mortality ratio, scorched height, percentage of scorched crown volume and bark char height.Main results: PU seems to be a very tolerant species to low and medium fire line intensity but fire effects were very significant when fire line intensity was high. In medium fireline intensity sites, probability of mortality ranged from 15 to 30% and the dead trees had the highest values on scorched height and percentage of scorched crown volume.Research highlights: Results from this work supports that prescribed burning might be used to efficiently decrease fuel load and fuel vertical continuity while avoiding considerable PU mortality. It also displayed that when fuel management has been implemented, PU mortality might be limited even under extreme fire behavior.Abbreviations used: PU: Pinus uncinata Ram.

  9. Fire effects in Pinus uncinata Ram plantations

    Energy Technology Data Exchange (ETDEWEB)

    Cardil Forradellas, A.; Molina Terrén, D.M.; Oliveres, J.; Castellnou, M.

    2016-07-01

    Aim of study: Understanding fire ecology of main forest species is essential for a sound, scientifically based on managing of wildlands and also to assess likely implications due to changes in fire regime under a global change scenario. Few references can be found about fire ecology of Pinus uncinata Ram. (PU). PU species grows in the Central Pyrenees where large, severe wildland fires did not occur frequently in the past. However, several fires with extreme fire behavior have affected PU stands in last years and they might disturb other PU forest in the future. Area of study: Cabdella fire (February 2012), in Lleida province, is one of the several wildland fires occurred in 2012 (winter season) in the Central Pyrenees. Fire affected a large PU plantation (102 ha) located at 1.800-2,100 meters above the sea. Material and methods: We have analyzed first order fire effects in three fireline intensity thresholds along three years in terms of mortality ratio, scorched height, percentage of scorched crown volume and bark char height. Main results: PU seems to be a very tolerant species to low and medium fire line intensity but fire effects were very significant when fire line intensity was high. In medium fireline intensity sites, probability of mortality ranged from 15 to 30% and the dead trees had the highest values on scorched height and percentage of scorched crown volume. Research highlights: Results from this work supports that prescribed burning might be used to efficiently decrease fuel load and fuel vertical continuity while avoiding considerable PU mortality. It also displayed that when fuel management has been implemented, PU mortality might be limited even under extreme fire behavior. (Author)

  10. A Study of the Failure of Joints in Composite Material Fuel Cells Due to Hydraulic Ram Loading

    Science.gov (United States)

    1976-06-01

    H co PSw Z QW <H W CO 33 PS4 o CO O CM \\ Q> 00 vO m CO CM N ra Figure VI.B.l THICKNESS MODEL 55 it acts upon on the membrane, gives the force to be...ability of the joint to carry the loads created by hydraulic ram loading. It would also make the manufacturing procedure easier, less time consuming , and...70 less expensive. Cutting holes and channels in a composite plate not only alters the behavior and load carrying capa- bility of the plate, but it is

  11. Windsock memory COnditioned RAM (CO-RAM) pressure effect: Forced reconnection in the Earth's magnetotail

    Science.gov (United States)

    Vörös, Z.; Facskó, G.; Khodachenko, M.; Honkonen, I.; Janhunen, P.; Palmroth, M.

    2014-08-01

    Magnetic reconnection (MR) is a key physical concept explaining the addition of magnetic flux to the magnetotail and closed flux lines back-motion to the dayside magnetosphere. This scenario elaborated by Dungey (1963) can explain many aspects of solar wind-magnetosphere interaction processes, including substorms. However, neither the Dungey model nor its numerous modifications were able to explain fully the onset conditions for MR in the tail. In this paper, we introduce new onset conditions for forced MR in the tail. We call our scenario the "windsock memory conditioned ram pressure effect." Our nonflux transfer-associated forcing is introduced by a combination of the large-scale windsock motions exhibiting memory effects and solar wind dynamic pressure actions on the nightside magnetopause during northward oriented interplanetary magnetic field (IMF). Using global MHD Grand Unified Magnetosphere Ionosphere Coupling Simulation version 4 simulation results, upstream data from Wind, magnetosheath data from Cluster 1 and distant tail data from the two-probe Acceleration, Reconnection, Turbulence and Electrodynamics of the Moon's Interaction with the Sun mission, we show that the simultaneous occurrence of vertical windsock motions of the magnetotail and enhanced solar wind dynamic pressure introduces strong nightside disturbances, including enhanced electric fields and persistent vertical cross-tail shear flows. These perturbations, associated with a stream interaction region in the solar wind, drive MR in the tail during episodes of northward oriented interplanetary magnetic field (IMF). We detect MR indirectly, observing plasmoids in the tail and ground-based signatures of earthward moving fast flows. We also consider the application to solar system planets and close-in exoplanets, where the proposed scenario can elucidate some new aspects of solar/stellar wind-magnetosphere interactions.

  12. The behavioral component of the ram effect: the influence of ram sexual behavior on the induction of estrus in anovulatory ewes.

    Science.gov (United States)

    Perkins, A; Fitzgerald, J A

    1994-01-01

    The objective of this study was to test whether the sexual behavior of the ram affects the ram effect. Rams exhibiting either high (HP) or low (LP) levels of sexual performance (on the basis of serving capacity tests) were exposed to 89 anestrous ewes for 28 d. Thirty-two anestrous ewes were not exposed to rams. The objective of this study was to compare the efficacy of estrus induction by HP (n = 4) vs LP (n = 4) rams. Plasma progesterone concentration was used as an index of ovarian activity. Groups of ewes were exposed to either an HP or an LP ram in a .32-ha pasture. Courtship behaviors of rams were recorded for 6 h on the initial day of exposure and for 30-min periods on alternate days thereafter. A greater percentage of ewes exposed to HP rams ovulated (95%) compared with ewes exposed to LP rams (78%) (P sexual behavior. These data imply that in addition to a pheromone the sexual behavior of the ram may be important in initiating ovarian cycle activity.

  13. Effects of breed and ram exposure on Spring estrous behavior and Summer fertility in domestic ewes

    OpenAIRE

    Nugent, Russell A., III

    1987-01-01

    The present studies were conducted to check the effects of acute ram introduction into a flock of anestrus ewes in Virginia. Ewes were bled via jugular venipuncture twice weekly and serum samples were radioimmunoassayed for progesterone (P4) content as an indicator of estrous activity. All rams were fitted with crayon equipped marking harnesses for use as an indicator of mating behavior in ewes. The first study tested the effects of introduction of vasectomized rams in...

  14. Effect of heterologous seminal plasma and semen extenders on motility of frozen-thawed ram spermatozoa

    Directory of Open Access Journals (Sweden)

    G.A. Mataveia

    2010-05-01

    Full Text Available Ram seminal plasma increases the fertility of frozen-thawed ram spermatozoa deposited into the cervix. The aim of the current study was to compare the effect of ram seminal plasma to that of bull seminal plasma, dog prostatic fluid, protein-free TALP, TrilEq (Triladyl with 0.5 mℓ of Equex STM paste added to each 100 mℓ and heat-treated skim milk on longevity and percentages of progressively motile and aberrantly motile frozen-thawed ram spermatozoa. Three ejaculates from each of 6 rams were extended in TrilEq, pooled and frozen in straws as a single batch per ram. One hundred and eight straws (3 straws from each ram for each fluid were thawed in random order. Once thawed, a straw was emptied into a tube with 0.85mℓ of the appropriate fluid at 37 °C and kept at that temperature for 6 h. Motility was assessed at x200 magnification immediately (time zero and 2, 4 and 6 h after thawing. Progressive motility decreased from each time to the next (P < 0.05 and was 39.0% (0 h, 26.0% (2 h, 19.6% (4 h and 12.6% (6 h; SEM 1.24, n=108 for each group. Ram seminal plasma resulted in higher progressive motility than bull seminal plasma, lower than milk, and similar to the other fluids. Ram seminal plasma resulted in lower aberrant motility than protein-free TALP and similar aberrant motility to other fluids. The effect of ram seminal plasma and dog prostatic fluid was very similar. The effect of ram seminal plasma on the fertility of frozen-thawed ram spermatozoa deposited into the cervix is not due an exceptionally beneficial effect on the motility of spermatozoa.

  15. Effect of semen extender and storage temperature on ram sperm motility over time

    Science.gov (United States)

    Storage of ram semen for long period of time depends on a number of factors, including type of extender and storage temperature. A study compared the effect of semen extender and storage temperature on motility of ram semen stored for 72 h. Semen collected via electroejaculator from 5 mature Katahd...

  16. The effect of cushion-ram pulsation on hot stamping

    Science.gov (United States)

    Landgrebe, Dirk; Rautenstrauch, Anja; Kunke, Andreas; Polster, Stefan; Kriechenbauer, Sebastian; Mauermann, Reinhard

    2016-10-01

    Hot stamping is an important technology for manufacturing high-strength components. This technology offers the possibility to achieve significant weight reductions. In this study, cushion-ram pulsation (CRP), a new technology for hot stamping on servo-screw presses, was investigated and applied for hot stamping. Compared to a conventional process, the tests yielded a significantly higher drawing depth. In this paper, the CRP technology and the first test results with hot stamping were described in comparison to the conventional process.

  17. the effect of freezing method on the survival of ram spermatozoa

    African Journals Online (AJOL)

    Sci.2l, 351. SALAIIiON, S., 1970. The survival of ram spermatozoa following pellet freezing below-79oC. Aust- .1. hiol..n'r. 13. 459. SALAMON, S. & BRANDON, M.R., l97l . Effect of compcition of thawing solution on sunrival of ram spernntozoa iroznn by the pellet method. Aust. J. biol. Sci. 24,355. SALAMON, S. & VISSER, D., ...

  18. Truck transport of RAM: Risk effects of avoiding metropolitan areas

    International Nuclear Information System (INIS)

    Mills, G.S.; Neuhauser, K.S.

    1997-11-01

    In the transport of radioactive material (RAM), e.g., spent nuclear fuel (SNF), stakeholders are generally most concerned about risks in high population density areas along transportation routes because of the perceived high consequences of potential accidents. The most significant portions of a transcontinental route and an alternative examined previously were evaluated again using population density data derived from US Census Block data. This method of characterizing population that adjoins route segments offers improved resolution of population density variations, especially in high population density areas along typical transport routes. Calculated incident free doses and accident dose risks for these routes, and the rural, suburban and urban segments are presented for comparison of their relative magnitudes. The results indicate that modification of this route to avoid major metropolitan areas through use of non-Interstate highways increases total risk yet does not eliminate a relatively small urban component of the accident dose risk. This conclusion is not altered by improved resolution of route segments adjoining high density populations

  19. Review of radiation effects on ReRAM devices and technology

    Science.gov (United States)

    Gonzalez-Velo, Yago; Barnaby, Hugh J.; Kozicki, Michael N.

    2017-08-01

    A review of the ionizing radiation effects on resistive random access memory (ReRAM) technology and devices is presented in this article. The review focuses on vertical devices exhibiting bipolar resistance switching, devices that have already exhibited interesting properties and characteristics for memory applications and, in particular, for non-volatile memory applications. Non-volatile memories are important devices for any type of electronic and embedded system, as they are for space applications. In such applications, specific environmental issues related to the existence of cosmic rays and Van Allen radiation belts around the Earth contribute to specific failure mechanisms related to the energy deposition induced by such ionizing radiation. Such effects are important in non-volatile memory as the current leading technology, i.e. flash-based technology, is sensitive to the total ionizing dose (TID) and single-event effects. New technologies such as ReRAM, if competing with or complementing the existing non-volatile area of memories from the point of view of performance, also have to exhibit great reliability for use in radiation environments such as space. This has driven research on the radiation effects of such ReRAM technology, on both the conductive-bridge RAM as well as the valence-change memories, or OxRAM variants of the technology. Initial characterizations of ReRAM technology showed a high degree of resilience to TID, developing researchers’ interest in characterizing such resilience as well as investigating the cause of such behavior. The state of the art of such research is reviewed in this article.

  20. CMOS/SOS RAM transient radiation upset and ''inversion'' effect investigation

    International Nuclear Information System (INIS)

    Nikiforov, A.Y.; Poljakov, I.V.

    1996-01-01

    The Complementary Metal-Oxide-Semiconductor/Silicon-on-Sapphire Random Access Memory (CMOS/SOS RAM) transient upset and inversion effect were investigated with pulsed laser, pulsed voltage generator and low-intensity light simulators. It was found that the inversion of information occurs due to memory cell photocurrents simultaneously with the power supply voltage drop transfer to memory cells outputs

  1. Reproductive performance of postpartum ewes treated with insulin or progesterone hormones in association with ram effect.

    Science.gov (United States)

    Ferreira-Silva, J C; Basto, Srl; Tenório Filho, F; Moura, M T; Silva Filho, M L; Oliveira, Mal

    2017-08-01

    The reproductive performance of postpartum Santa Inês (SI) and Morada Nova (MN) ewes treated with insulin or progesterone hormones in association with ram effect was evaluated. Ewes from SI (n = 69) and MN (n = 69) breeds were randomly allocated to three groups of each breed (T1-ram effect only; T2-ram effect + insulin; T3-ram effect + progesterone). Progesterone concentrations (ηg/ml; mean ± SD) before and after introduction of rams (n = 6) were 0.51 ± 0.22 and 3.78 ± 0.68 (T1), 0.65 ± 0.21 and 3.77 ± 0.78 (T2) and 0.52 ± 0.21 and 3.84 ± 0.84 (T3) in SI ewes and 0.74 ± 0.19 and 3.71 ± 0.56 (T1), 0.70 ± 0.21 and 3.79 ± 0.75 (T2) and 0.81 ± 0.14 and 3.87 ± 0.80 (T3) in MN ewes, respectively. Thus, lower progesterone concentrations were found before the introduction of rams (p ewes and at 64 (T1), 40 (T2) and 44 (T3) hr in MN ewes. The mean number of ovulations was similar between groups (p > .05), was 1.3 ± 0.51 (T1), 1.5 ± 0.54 (T2) and 1.6 ± 0.51 (T3) in SI ewes and 1.3 ± 0.51 (T1), 1.6 ± 0.51 (T2) and 1.6 ± 0.51 (T3) in MN ewes. In conclusion, the ram effect alone is effective at inducing and synchronizing oestrus in sheep under postpartum anoestrus, irrespective of hormone treatments. © 2017 Blackwell Verlag GmbH.

  2. Effects of Agricultural Byproducts in Ration on Productive and Reproductive Performance of Saidi Rams

    Directory of Open Access Journals (Sweden)

    G. A. Megahed

    2006-01-01

    Full Text Available The influence of selected agricultural byproducts supplementation to feed rations on the ram's body gain, reproductive performance, and subsequent fertility were investigated. Forty Saidi rams were divided into 4 groups (n = 10. Group 1 (control was fed 500 g/head/day concentrate feed mixtures (CFM plus wheat straw ad libitum. Groups 2, 3 and 4 were fed 500 g/head/day CFM plus corn cobs or sugar cane tops or sugar cane bagasse (these roughages were treated with 1% urea, respectively. Serum testosterone, glucose and total cholesterol levels were determined and semen evaluations were carried out every 15 days. Testicular size, scrotal circumference and body weight were recorded each month. At the end of the experiment, 12 rams were allowed to mount 114 healthy ewes to evaluate the pregnancy rate for each group. The results have shown that the body weight, daily body gain, testicular size and scrotal circumference increased (p p p < 0.01 as compared with group 1 (1.76 ± 0.09 ng/ml. Moreover, supplementation of treated agricultural byproducts had a significant improving effects on the semen quality. The semen volume increased, along with individual motility and live sperm percentages. Pregnancy rate in this study indicated that rams of groups 2, 3 and 4 yielded a higher pregnancy rate (83.33%, 86.67% and 81.48%, respectively than group 1 (74.07%. Agricultural byproducts such as corn cobs, sugar cane tops and sugar cane bagasse treated with 1% urea had a beneficial effect on the daily body gain and improved the reproductive performance and subsequent fertility of Saidi rams, compared to wheat straw.

  3. Características construtivas de um carneiro hidraúlico com materiais alternativos Hydraulic ram pump manufacturer features using alternative materials

    Directory of Open Access Journals (Sweden)

    Denis C. Cararo

    2007-08-01

    Full Text Available O objetivo deste trabalho foi avaliar um carneiro hidráulico construído com conexões roscáveis de PVC roscáveis e metálicas e garrafa de polietileno tereftálico (PET. O estudo foi realizado no Laboratório de Hidráulica da Universidade Federal de Lavras, MG. Testaram-se tamanhos de câmaras de ar (0,6 e 2,5L, diâmetros de furos da tampa da garrafa (5, 15 e 25mm, tipos de garrafa plástica (descartável de guaraná e descartável e retornável de refrigerante de cola, e posições da válvula de escape (vertical e horizontal, a diferentes pressões de recalque (48,39 a 483,92kPa, a cada 48,39 kPa. O desnível do reservatório de alimentação ao carneiro hidráulico foi mantido constante a 4,36m. Os resultados indicaram que a combinação de características construtivas que possibilitam melhor rendimento, maior vazão recalcada, menor vazão de alimentação e menor desperdício, foi o uso de garrafa PET descartável ou retornável com capacidade de 0,6L, válvula de escape na horizontal e tamanho de furo de 25mm na tampa da garrafa.Tests were conducted at the Hydraulics Laboratory of Universidade Federal de Lavras - UFLA, Lavras, to evaluate a hydraulic ram pump built with PVC and metallic threadable connections, and a bottle made with polyethylene tereftalic, known as PET. The manufacturer features tested were: bottle size (0.6 and 2.5L, hole size of the bottle top (5, 15 and 25mm, bottle models (disposable and returnable and valve positions (horizontal and vertical. The operational hydraulic head was 4.36m and the simulated pump elevation pressures were 48.39 to 483.92kPa and 48.39 to 48.39kPa. The best efficiency, the highest pumped water flow, the lowest operational water flow and the lowest waste water flow were obtained using the 0.6L PET disposable or returnable bottle with horizontal valve position and top size of 25mm.

  4. Effects of Aflatoxin on Liver and Protective Effectiveness of Esterified Glucomannan in Merino Rams

    Directory of Open Access Journals (Sweden)

    Fatma Colakoglu

    2012-01-01

    Full Text Available The effects of total aflatoxin (AF given orally on liver in Merino rams were studied. In addition, this study was conducted in order to evaluate the efficacy of an esterified glucomannan (EG for protection against aflatoxicosis. One-year-old 32 Merino rams were divided into four equal groups. The control group (C was fed with the commercial feed. The AF group was fed with commercial feed plus 250 μg/day of total AF. The EG group was fed with commercial feed plus 2 g/day of EG. The AF + EG group was fed with commercial feed plus 250 μg/day of total AF and 2 g/day of EG. After feeding period, tissue samples were taken from the liver in order to perform histological analyses. Vacuolar degeneration with small and large droplets and hydropic degeneration in hepatocytes were observed in the AF group. The ceroid pigmentation was observed in macrophages in groups or one by one. It was observed that the fat rate in hepatocytes was 2.6% in the C group, 35.5% in the AF group, 2.9% in the EG group, and 9.6% in the AF + EG group. In conclusion, the adverse effects caused by aflatoxicosis on the liver could be ameliorated by adding EG to the ration.

  5. Effect of different extenders on ram sperm traits during storage

    Directory of Open Access Journals (Sweden)

    Zdeňka Hegedűšová

    2012-01-01

    Full Text Available The aim of the study was to test commercial extenders used for short-term and long-term sperm preservation. Semen was collected in the reproduction season, i.e. from June to December. The ejaculates were obtained from single services and the routine analysis of the semen was performed immediately after the collection. The examination included semen volume, colour and texture, sperm concentration and motility, ejaculate turbulence and percentage of sperm with abnormal morphology. The semen was diluted with an extender in the ratio of 1:4. The processed semen was transported in an insulated container at 16–18 °C to the laboratory and stored in a stationary thermostat under the same temperature. Sperm motility tests were performed 24, 48, 72 and 96 hours after the placement in to thermostat. Ejaculates diluted with Ovipro, Optidyl, Triladyl and Andromed CSS gave very good results of viability (81.23 %–83.41 % after 24 hours of storage. After 48 hours, Ovipro, Andromed, Optidyl and Triladyl gave values above 75 %. The Triladyl extender proved to be a good stabilizing agent, showing consistent results during a long-term storage. It was chosen as a control one for overall assessment. Other preservation media did not show any improving or worsening effects. The extender Ovipro showed a high motility effect in the first 48 hours only, and hence it appears to be the best solution for the short-term preservation.

  6. RAM, an RGDS analog, exerts potent anti-melanoma effects in vitro and in vivo.

    Directory of Open Access Journals (Sweden)

    Maria Simona Aguzzi

    Full Text Available Peptides containing the RGD sequence are under continuous investigation given their ability to control cell adhesion and apoptosis. Since small peptides are quickly metabolized and degraded in vivo, developing analogs resistant to serum-induced degradation is a challenging task. RGD analogs developed so far are known as molecules mostly inhibiting cell adhesion; this feature may reduce cell proliferation and tumor development but may not induce regression of tumors or metastases already formed. In the current study, carried out in melanoma in vitro and in vivo models, we show that RAM, an RGD-non-peptide Analog-Molecule, strongly inhibits cells adhesion onto plastic, vitronectin, fibronectin, laminin and von Willebrand Factor while it does not inhibit cell adhesion onto collagen IV, similarly to the RGDS template peptide. It also strongly inhibits in vitro cell proliferation, migration and DNA-synthesis, increases melanoma cells apoptosis and reduces survivin expression. All such effects were observed in collagen IV seeded cells, therefore are most likely independent from the anti adhesive properties. Further, RAM is more stable than the template RGDS; in fact it maintains its anti-proliferation and anti-adhesion effects after long serum exposure while RGDS almost completely loses its effects upon serum exposure. In a mouse metastatic melanoma in vivo model, increasing doses of RAM significantly reduce up to about 80% lung metastases development, while comparable doses of RGDS are less potent. In conclusion these data show that RAM is a potent inhibitor of melanoma growth in vitro, strongly reduces melanoma metastases development in vivo and represents a novel candidate for further in vivo investigations in the cancer treatment field.

  7. The Effects of Ram Pressure on the Cold Clouds in the Centers of Galaxy Clusters

    Science.gov (United States)

    Li, Yuan; Ruszkowski, Mateusz; Tremblay, Grant

    2018-02-01

    We discuss the effect of ram pressure on the cold clouds in the centers of cool-core galaxy clusters, and in particular, how it reduces cloud velocity and sometimes causes an offset between the cold gas and young stars. The velocities of the molecular gas in both observations and our simulations fall in the range of 100–400 km s‑1, which is much lower than expected if they fall from a few tens of kiloparsecs ballistically. If the intracluster medium (ICM) is at rest, the ram pressure of the ICM only slightly reduces the velocity of the clouds. When we assume that the clouds are actually “fluffier” because they are co-moving with a warm-hot layer, the velocity becomes smaller. If we also consider the active galactic nucleus wind in the cluster center by adding a wind profile measured from the simulation, the clouds are further slowed down at small radii, and the resulting velocities are in general agreement with the observations and simulations. Because ram pressure only affects gas but not stars, it can cause a separation between a filament and young stars that formed in the filament as they move through the ICM together. This separation has been observed in Perseus and also exists in our simulations. We show that the star-filament offset, combined with line-of-sight velocity measurements, can help determine the true motion of the cold gas, and thus distinguish between inflows and outflows.

  8. Effect of Freezing on Spermatozoa from Tigaie Rams Belonging to the Mountain Ecotype

    Directory of Open Access Journals (Sweden)

    Vasile Miclea

    2011-05-01

    Full Text Available Our aim was to study the influence of freezing on the viability and frequency of abnormalities in frozen ram spermatozoa. Sperm was collected form 20 rams belonging to the mountain ecotype of the Tigaie breed using the artificial vagina technique and volume and motility were assessed. Afterward it was diluted with Tryladil (1:4 supplemented with 20% egg yolk and heated at 37°C. Subsequently the temperature decreased at a rate of 0.2°C/minute until reaching 4°C and an equilibration time of 2 hours followed. During this time the diluted sperm was packaged in 0.25 ml straws. After sealing these were kept 6 cm above liquid nitrogen level for 13 minutes (- 120°C and then plunged into nitrogen. Volume, motility and concentration were assessed before freezing. After thawing sperm morphology was assessed using Hancock’s method and at the same time the endurance (at 10, 30 and 60 minutes and HOST tests were performed. The highest motility (0.40 was graded at 30 minutes. It could be correlated with the increased percentage of HOST positive spermatozoa, 27.78%. The percentage of abnormal spermatozoa was also high (47.89%, 38.44% of them having acrosome flaws. Cryopreservation has a negative effect on the characteristics of sperm cells from Tigaie rams belonging to the mountain ecotype.

  9. The collaborative effect of ram pressure and merging on star formation and stripping fraction

    Science.gov (United States)

    Bischko, J. C.; Steinhauser, D.; Schindler, S.

    2015-04-01

    Aims: We investigate the effect of ram pressure stripping (RPS) on several simulations of merging pairs of gas-rich spiral galaxies. We are concerned with the changes in stripping efficiency and the time evolution of the star formation rate. Our goal is to provide an estimate of the combined effect of merging and RPS compared to the influence of the individual processes. Methods: We make use of the combined N-body/hydrodynamic code GADGET-2. The code features a threshold-based statistical recipe for star formation, as well as radiative cooling and modeling of galactic winds. In our simulations, we vary mass ratios between 1:4 and 1:8 in a binary merger. We sample different geometric configurations of the merging systems (edge-on and face-on mergers, different impact parameters). Furthermore, we vary the properties of the intracluster medium (ICM) in rough steps: the speed of the merging system relative to the ICM between 500 and 1000 km s-1, the ICM density between 10-29 and 10-27 g cm-3, and the ICM direction relative to the mergers' orbital plane. Ram pressure is kept constant within a simulation time period, as is the ICM temperature of 107 K. Each simulation in the ICM is compared to simulations of the merger in vacuum and the non-merging galaxies with acting ram pressure. Results: Averaged over the simulation time (1 Gyr) the merging pairs show a negligible 5% enhancement in SFR, when compared to single galaxies under the same environmental conditions. The SFRs peak at the time of the galaxies first fly-through. There, our simulations show SFRs of up to 20 M⊙ yr-1 (compared to 3 M⊙ yr-1 of the non-merging galaxies in vacuum). In the most extreme case, this constitutes a short-term (<50 Myr) SFR increase of 50 % over the non-merging galaxies experiencing ram pressure. The wake of merging galaxies in the ICM typically has a third to half the star mass seen in the non-merging galaxies and 5% to 10% less gas mass. The joint effect of RPS and merging, according

  10. Effect of Subsoil Compaction on Hydraulic Parameters

    DEFF Research Database (Denmark)

    Iversen, Bo Vangsø; Berisso, Feto Esimo; Schjønning, Per

    Soil compaction is a major threat to sustainable soil quality and is increasing since agricultural machinery is becoming heavier and is used more intensively. Compaction not only reduces pore volume, but also modifies the pore connectivity. The inter-Nordic research project POSEIDON (Persistent...... effects of subsoil compaction on soil ecological services and functions) put forward the hypothesis that due to a decrease in the hydraulic conductivity in the soil matrix, compaction increases the frequency of preferential flow events in macropores and therefore increases the leaching of otherwise....... In the field the near-saturated hydraulic conductivity was measured with a tension infiltrometer in the same treatments at a depth of 30 cm. In the laboratory saturated and near-saturated hydraulic conductivity and the bulk density were measured as well. Also, macropores in the large soil cores were made...

  11. Memoria RAM

    DEFF Research Database (Denmark)

    Cruz Suárez, Juan Carlos

    2013-01-01

    The present study intends to open a new theoretical means of analysis within the field of comparative memories. Through the metaphorical designation of RAM memory we will try to observe the continuous circulation of social discourses related to the collective memory of a particular community. Thi...

  12. The ram effect: New insights into neural modulation of the gonadotropic axis by male odors and socio-sexual interactions.

    Directory of Open Access Journals (Sweden)

    CLAUDE eFABRE NYS

    2015-04-01

    Full Text Available Reproduction in mammals is controlled by the hypothalamo-pituitary-gonadal (HPG axis under the influence of external and internal factors such as photoperiod, stress, nutrition, and social interactions. Sheep are seasonal breeders and stop mating when day length is increasing (anestrus. However, interactions with a sexually active ram during this period can override the steroid negative feedback responsible for the anoestrus state, stimulate LH secretion and eventually reinstate cyclicity. This is known as the ram effect and research into the mechanisms underlying it is shedding new light on HPG axis regulation. The first step in the ram effect is increased LH pulsatile secretion in anestrus ewes exposed to a sexually active male or only to its fleece, the latter finding indicating a pheromone-like effect. Estradiol secretion increases in all ewes and this eventually induces a LH surge and ovulation, just as during the breeding season. An exception is a minority of ewes that exhibit a precocious LH surge (within 4h with no prior increase in estradiol. The main olfactory system and the cortical nucleus of the amygdala are critical brain structures in mediating the ram effect since it is blocked by their inactivation. Sexual experience is also important since activation (increased c-fos expression in these and other regions is greatly reduced in sexually naïve ewes. In adult ewes kisspeptin neurons in both arcuate and preoptic regions and some preoptic GnRH neurons are activated 2h after exposure to a ram. Exposure to rams also activates noradrenergic neurons in the locus coeruleus and A1 nucleus and increased noradrenalin release occurs in the posterior preoptic area. Pharmacological modulation of this system modifies LH secretion in response to the male or his odor. Together these results show that the ram effect can be a fruitful model to promote both a better understanding of the neural and hormonal regulation of the HPG axis in general and

  13. Effects of supplemental humic acid on ruminal fermentation and blood variables in rams

    Directory of Open Access Journals (Sweden)

    Nurten Galip

    Full Text Available In this study, we particularly aimed to research the effect of supplemental humic acid on ruminal fermentation and blood variables in rams. A trial was conducted to evaluate the effect of humic acid (HA on protozoa count, percentages of different protozoa types and blood parameters. Three male Kivircik rams with ruminal cannula were used in a Latin square design, during 22 days periods (15 days for adaptation, 7 days for collection. They received 0 control group (CG, 5 g/day or 10 g/day of HA (HA5, HA10, assay groups. HA were added to the ration with grain diet. Ration was consisted of 5% grain diet and 95 % alfalfa hay. Rumen contents collected before, 3h and 6h after morning feeding on days 1 and 7 in each collection period were analyzed. Blood samples were also collected the same days. No significant difference in biochemical and hematological parameters (except eosinophils levels, P<0.05, variables of ruminal fluid (except sodium levels before feeding and species of rumen protozoa organism (except the percentage Epidinium spp. were evidenced with the addition of HA. In conclusion, we think that they might have been true the widely use in animal food of humates which don’t have any negative effect on biochemical and hematological parameters in particular.

  14. Effects of supplemental humic acid on ruminal fermentation and blood variables in rams

    Directory of Open Access Journals (Sweden)

    Umit Polat

    2010-11-01

    Full Text Available In this study, we particularly aimed to research the effect of supplemental humic acid on ruminal fermentation and blood variables in rams. A trial was conducted to evaluate the effect of humic acid (HA on protozoa count, percentages of different protozoa types and blood parameters. Three male Kivircik rams with ruminal cannula were used in a Latin square design, during 22 days periods (15 days for adaptation, 7 days for collection. They received 0 control group (CG, 5 g/day or 10 g/day of HA (HA5, HA10, assay groups. HA were added to the ration with grain diet. Ration was consisted of 5 % grain diet and 95 % alfalfa hay. Rumen contents collected before and, 3h and 6h after morning feeding on days 1 and 7 in each collection period were analyzed. Blood samples were also collected the same days. No significant difference in biochemical and hematological parameters (except eosinophils levels, P, variables of ruminal fluid (except sodium levels before feeding and species of rumen protozoa organism (except the percentage Epidinium spp. were evidenced with the addition of HA. In conclusion, we think that they might have been true the widely use in animal food of humates which don’t have any negative effect on biochemical and hematological parameters in particular. 

  15. Effects of experimental Trypanosoma congolense infection on sperm morphology in Yankasa rams

    Directory of Open Access Journals (Sweden)

    Oluyinka O. Okubanjo

    2015-10-01

    Full Text Available The objective of the study was to determine the effect of T. congolense on the sperm morphology of Yankasa rams (YKR. Nine YKR aged 24-30 months-old were assigned into two groups of 6 infected and 3 uninfected control and were monitored for 7 weeks. The infected group of YKR was each inoculated with 1 x 106 T. congolense through the jugular vein, while the control group remained uninfected. The entire infected group developed trypanosomosis post infection (pi characterized by sperm morphological abnormalities in the semen. There were significant (P<0.001 increases in the mean percentage of acrosomal, head, middle piece and tail abnormalities. Proximal and distal droplets as well detached heads were also significantly (P<0.001 increased post infection (pi. Acrosomal abnormalities, distal droplet and tail abnormalities increased from week 1 pi till the end of the study, while head abnormalities and detached heads increased from week 2 pi. Middle piece abnormalities and proximal droplets increased from week 3 and 4 pi till the end of the study respectively. The high incidence of morphological defects caused by T. congolense is capable of causing infertility from the first week pi thereby making the rams unfit for breeding at the end of the study.

  16. Carneiro hidráulico com tubulação de alimentação em aço galvanizado e em PVC Hydraulic ram pump perfomance with PVC and steel pipes

    Directory of Open Access Journals (Sweden)

    Caroline Abate

    2002-03-01

    Full Text Available A recente crise da energia convencional tem ocasionado a exploração de fontes alternativas de energia. O bombeamento de água utilizando carneiro hidráulico é amplamente empregado em propriedades onde a energia elétrica é escassa ou inexistente. Procurando dar subsídios técnicos para a utilização do PVC nos sistemas de alimentação de um carneiro hidráulico, foi desenvolvido um experimento com objetivo de avaliar o desempenho de um carneiro hidráulico quando alimentado por uma tubulação de PVC e outra de aço galvanizado, sob três alturas de queda (2,1, 3,8 e 4,7 m. Foi utilizada a equação de D'Aubussion's para a avaliação do rendimento, calculado a partir de leituras de altura de recalque, vazão de escape, vazão de recalque e altura de alimentação. Pode-se conseguir o máximo rendimento com o carneiro hidráulico utilizando-se de tubulação de PVC com até 4,2 m de desnível; além desse valor a tubulação de aço galvanizado é mais eficiente.The recent conventional energy crisis is leading to the exploration of alternative energy sources. The pumping of water using ram pumps is widely used in farms where electric energy is scarce or inexistent. This experiment was carried out to evaluate the performance of an hydraulic ram pump utilizing two kinds of supply pipes (PVC and steel using three different supply heads (2.1, 3.8 and 4.7. Delivery head, delivery discharge, waste discharge and supply head were utilized to calculate the yield of the hydraulic ram by the equation of D'Aubussion. The maximum yield of the hydraulic ram was obtained for the PVC pipe for the 4.2 m head; for heads higher than 4.2 m the steel pipe was more efficient.

  17. Negative effect of combined cysteine and glutathione in soy lecithin-based extender on post-thawed ram spermatozoa.

    Science.gov (United States)

    Zhandi, Mahdi; Sharafi, Mohsen

    2015-09-01

    This study was conducted to evaluate the effect of combined cysteine and glutathione in soy lecithin-based semen extender on post-thawed ram sperm quality. A total of 28 ejaculates were collected twice a week (from four rams) during breeding season. In each replicate, semen samples (n = 4, one ejaculate for each ram) were pooled and divided into three equal parts, and each part was diluted with one of following extender: (1) soy lecithin-based extender containing no cysteine and no glutathione (C0-G0), (2) soy lecithin-based extender containing cysteine (5 mM) and glutathione (5 mM) (C5-G5), and (3) soy lecithin-based extender containing cysteine (10 mM) and glutathione (10 mM) (C10-G10). After freeze-thawing process, motility and velocity parameters, plasma membrane integrity and functionality, mitochondrial activity, and apoptosis features of spermatozoa were evaluated. The obtained results showed that total and progressive motility, plasma membrane integrity and functionality, and live post-thawed spermatozoa was lower in C10-G10 extender compared to C0-G0 and C5-G5 extenders (P 0.05). In conclusion, it seems that high concentration of combined cysteine and glutathione in soy lecithin-based semen extender has a detrimental effect of post-thawed ram sperm quality.

  18. PC-version of RAM6-code for calculation of parameters of the effective logarithmic boundary condition at the absorbent rod surface in reactor

    International Nuclear Information System (INIS)

    Le Van Ngoc; Ngo Dang Nhan

    1990-01-01

    The RAM-6 code for calculation of parameters of the effective logarithmic boundary condition at the absorbent rod surface in reactor is suitably modofied to work on IBM PC, the instructions for its usage are presented and capabilities of the personal cpmputer oriented RAM-6 code are demonstrated. (author). 4 refs, 5 tabs, 2 figs

  19. Effects of diluting medium and holding time on sperm motility analysis by CASA in ram

    Directory of Open Access Journals (Sweden)

    Somayeh Mostafapor

    2014-06-01

    Full Text Available The aim of this study was to evaluate the effects of dilution rate and holding time on various motility parameters using computer-assisted sperm analysis (CASA. The semen samples were collected from three Ghezel rams. Samples were diluted in seminal plasma (SP, phosphate-buffered saline (PBS containing 1% bovine serum albumin (BSA and Bioexcell. The motility parameters that computed and recorded by CASA include curvilinear velocity (VCL, straight line velocity (VSL, average path velocity (VAP, straightness (STR, linearity (LIN, amplitude of lateral head displacement (ALH, and beat cross frequency (BCF. In all diluters, there was a decrease in the average of all three parameters of sperms movement velocity as the time passed, but density of this decrease was more intensive in SP. The average of ALH between diluters indicated a significant difference, as it was more in Bioexcell in comparison with the similar amount in SP and PBS. The average of LIN in the diluted sperms in Bioexcell was less than two other diluters in all three times. The motility parameters of the diluted sperms in Bioexcell and PBS indicated an important and considerable difference with the diluted sperms in SP. According to the gained results, the Bioexcell has greater ability in preserving motility of sperm in comparison with the other diluters but as SP is considered as physiological environment for sperm. It seems that the evaluation of the motility parameters in Bioexcell and PBS cannot be an accurate and comparable evaluation with SP.

  20. Effects of diluting medium and holding time on sperm motility analysis by CASA in ram.

    Science.gov (United States)

    Mostafapor, Somayeh; Farrokhi Ardebili, Farhad

    2014-01-01

    The aim of this study was to evaluate the effects of dilution rate and holding time on various motility parameters using computer-assisted sperm analysis (CASA). The semen samples were collected from three Ghezel rams. Samples were diluted in seminal plasma (SP), phosphate-buffered saline (PBS) containing 1% bovine serum albumin (BSA) and Bioexcell. The motility parameters that computed and recorded by CASA include curvilinear velocity (VCL), straight line velocity (VSL), average path velocity (VAP), straightness (STR), linearity (LIN), amplitude of lateral head displacement (ALH), and beat cross frequency (BCF). In all diluters, there was a decrease in the average of all three parameters of sperms movement velocity as the time passed, but density of this decrease was more intensive in SP. The average of ALH between diluters indicated a significant difference, as it was more in Bioexcell in comparison with the similar amount in SP and PBS. The average of LIN in the diluted sperms in Bioexcell was less than two other diluters in all three times. The motility parameters of the diluted sperms in Bioexcell and PBS indicated an important and considerable difference with the diluted sperms in SP. According to the gained results, the Bioexcell has greater ability in preserving motility of sperm in comparison with the other diluters but as SP is considered as physiological environment for sperm. It seems that the evaluation of the motility parameters in Bioexcell and PBS cannot be an accurate and comparable evaluation with SP.

  1. Protective effects of Opuntia ficus-indica extract on ram sperm quality, lipid peroxidation and DNA fragmentation during liquid storage.

    Science.gov (United States)

    Allai, Larbi; Druart, Xavier; Öztürk, Mehmet; BenMoula, Anass; Nasser, Boubker; El Amiri, Bouchra

    2016-12-01

    The present study aimed to assess the phenolic composition of the acetone extract from Opuntia ficus indica cladodes (ACTEX) and its effects on ram semen variables, lipid peroxidation and DNA fragmentation during liquid storage at 5°C for up to 72h in skim milk and Tris egg yolk extenders. Semen samples from five rams were pooled extended with Tris-egg yolk (TEY) or skim milk (SM) extenders containing ACTEX (0%, 1%, 2%, 4% and 8%) at a final concentration of 0.8×10 9 sperm/ml and stored for up to 72h at 5°C. The sperm variables were evaluated at different time periods (8, 24, 48 and 72h). Sperm total motility and viability were superior in TEY than in SM whereas the progressive motility, membrane integrity, abnormality and spontaneous lipid peroxidation were greater in SM compared to TEY (P<0.05). The results also indicated that the inclusion of 1% ACTEX in the SM or TEY extender increased the sperm motility, viability, membrane integrity, and decreased the abnormality, lipids peroxidation up to 72h in storage compared to control group. Similarly, even at 72h of storage, 1% ACTEX can efficiently decrease the negative effects of liquid storage on sperm DNA fragmentation (P<0.05). In conclusion, SM and TEY supplemented with 1% of ACTEX can improve the quality of ram semen. Further studies are required to identify the active components in ACTEX involved in its effect on ram sperm preservation. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. Experimental and simulation study of the effects of cosmic particles on CMOS/SOS RAMs

    International Nuclear Information System (INIS)

    Worley, E.; Williams, R.; Groninger, J.

    1990-01-01

    Van De Graaff particle accelerator data was taken on three different CMOS/SOS RAM cells. The resulting LET upset thresholds were then used to calculate the deposited charge needed to upset the cells. Detailed SPICE simulations of the various cells were used to determine the collected charge required for upset. A comparison of the two values indicated that the charge needed to upset the cells was greater than the deposited charge, thus confirming Rollins' results. Shorter channel lengths and higher power supply voltages caused the ratio, M, of upset charge to deposited charge to increase. As a result of this multiplication factor, actual devices are more likely to upset (i.e., upset at lower energy) than expected from an analysis of only the collected charge. A mixed mode simulator was then used to model the charge collection process. This simulator study showed that the M factor is a very fluid number which is dependent on minority carrier lifetime, drain voltage, and the switching dynamics of the cell in addition to the dependence on mobility ratio and channel length. Parasitic bipolar gain at high injection levels appears to be the primary mechanism allowing collected charge to be greater than deposited charge. In conclusion, the simulator and experimental data show that, as floating body static memory transistors are down scaled, the particle energy needed to upset the cell is reduced because of the enhanced parasitic bipolar gain effect as well as a reduction in the node capacitance. This result is shown by simulation to also apply to fully depleted SOI transistors

  3. The effect of reactive ion etch (RIE) process conditions on ReRAM device performance

    Science.gov (United States)

    Beckmann, K.; Holt, J.; Olin-Ammentorp, W.; Alamgir, Z.; Van Nostrand, J.; Cady, N. C.

    2017-09-01

    The recent surge of research on resistive random access memory (ReRAM) devices has resulted in a wealth of different materials and fabrication approaches. In this work, we describe the performance implications of utilizing a reactive ion etch (RIE) based process to fabricate HfO2 based ReRAM devices, versus a more unconventional shadow mask fabrication approach. The work is the result of an effort to increase device yield and reduce individual device size. Our results show that choice of RIE etch gas (SF6 versus CF4) is critical for defining the post-etch device profile (cross-section), and for tuning the removal of metal layers used as bottom electrodes in the ReRAM device stack. We have shown that etch conditions leading to a tapered profile for the device stack cause poor electrical performance, likely due to metal re-deposition during etching, and damage to the switching layer. These devices exhibit nonlinear I-V during the low resistive state, but this could be improved to linear behavior once a near-vertical etch profile was achieved. Device stacks with vertical etch profiles also showed an increase in forming voltage, reduced switching variability and increased endurance.

  4. Effect of Poroelasticity on Hydraulic Fracture Interactions

    DEFF Research Database (Denmark)

    Usui, Tomoya; Salimzadeh, Saeed; Paluszny, Adriana

    2017-01-01

    This study investigates, by performing finite element-based simulations, the influence of fluid leak-off and poroelasticity on growth of multiple hydraulic fractures that initiate from a single horizontal well. In this research, poroelastic deformation of the matrix is coupled with fluid flow in ...

  5. Analysis of hydraulic bearing effect for vertical-shaft pump

    International Nuclear Information System (INIS)

    Narabayashi, Tadashi; Mawatari, Katsuhiko; Uchida, Ken; Iikura, Takahiko; Hayakawa, Kiyoshi

    1999-01-01

    In inner-rotating non coaxial cylinders, axial flow causes a hydraulic being effect by which the inner cylinder is put at the center of the axis of the outer cylinder, because of the pressure distribution along the surface of the inner cylinder. When the rotating speed becomes higher, whirl force is generated by the pressure distribution in the narrow gap side. Therefore, pocket-type hydraulic being was added between the rotor and the wearing, based on an experiment and flow analysis. The pockets suck a part of discharged water of a pump and pressurize a water along the rotational direction in the pocket. The pressurized water enhance the hydraulic being effect. The analysis results showed good agreement with the experiments, and the analysis method for the hydraulic being for vertical-shaft pump was established. (author)

  6. Study of the effects of breed on some innate immunity parameters in rams

    Directory of Open Access Journals (Sweden)

    Genova Krasimira

    2013-09-01

    Full Text Available Investigations were carried out on 26 rams from the breeds Karakachan and Copper-Red Shoumen. The non-specific immune parameters, phagocytic activity of leukocytes, bactericidal activity of phagocytes systems (oxygen-dependent and oxygen independent and total plasma protein level were evaluated. Phagocytic response was evaluated against S. aureus 209-P with a certain percentage of active phagocytes (phagocytic index and the number of absorbed particles per one phagocytic cells (phagocyte number. Phagocytosis completion index was defined as the percentage of the microbial cells that have been destroyed by phagocytes after incubation. State of the oxygen-dependent bactericidal systems of phagocytes was assessed in vitro using the NBT test, which reflects the ability of superoxide restore NBT in diphormazane. NBT test was evaluated by the degree of reduction in spontaneous and stimulated reactions, taking into account the intracellular deposits diphormazane. Our studies and results shows that the rams from the two local Bulgarian breeds have a high activity of innate immune parameters and that’s may be useful and important in the breeding programs as an indicator of resistance and highly tolerance to oxidative stress.

  7. Endocrine and Ovarian Changes in Response to the Ram Effect in Medroxyprogesterone Acetate-primed Corriedale Ewes During the Breeding and Nonbreeding Season

    Directory of Open Access Journals (Sweden)

    Rubianes E

    2005-03-01

    Full Text Available Two experiments were performed to determine the endocrine and ovarian changes in medroxyprogesterone acetate (MAP-primed ewes after ram introduction. Experiment 1 was performed during the mid-breeding season with 71 ewes primed with an intravaginal MAP sponge for 12 days. While the control (C ewes (n = 35 were in permanent contact with rams, the ram effect (RE ewes (n = 36 were isolated for 34 days prior to contact with rams. At sponge withdrawal, all ewes were joined with eight sexually experienced marking Corriedale rams and estrus was recorded over the next 4 days. The ovaries were observed by laparoscopy 4–6 days after estrus. Four weeks later, pregnancy was determined by transrectal ultrasonography. In eight ewes from each group, ovaries were ultrasonographically scanned; FSH, LH, and estradiol-17β were measured every 12 hours until ovulation or 96 hours after estrus. The response to the rams was not affected by the fact that ewes had been kept or not in close contact with males before teasing. No differences were found in FSH, LH, estradiol-17β concentrations, growth of the ovulatory follicle, onset of estrus, ovulation rate, or pregnancy rate. Experiment 2 was performed with 14 ewes during the nonbreeding season. Ewes were isolated from rams for 1 month, and received a 6-day MAP priming. Ovaries were ultrasonographically scanned every 12 hours, and FSH, LH, estradiol-17β, and progesterone were measured. Ewes that ovulated and came into estrus had higher FSH and estradiol-17β levels before introduction of the rams than did ewes that had a silent ovulation. The endocrine pattern of the induced follicular phase of ewes that came into estrus was more similar to a normal follicular phase, than in ewes that had a silent ovulation. The follicle that finally ovulated tended to emerge earlier and in a more synchronized fashion in those ewes that did come into estrus. All ewes that ovulated had an LH surge and reached higher maximum FSH

  8. Effects of Oxidized Glutathione, Bovine Serum Albumin, Cysteine and Lycopene on the Quality of Frozen-Thawed Ram Semen

    Directory of Open Access Journals (Sweden)

    O. Uysal

    2007-01-01

    Full Text Available Free radicals are known to be involved in lipid peroxidation as well as DNA and sperm membrane damages that may lead to decreased sperm motility or cell death. The balance between free radical production and their detoxification may be an important factor in sperm survival and function before, during and after cryopreservation. The aim of this study was to determine the effects of the addition of the antioxidants of oxidized glutathione (GSSG, bovine serum albumin (BSA, cysteine and lycopene to freezing media on the post-thawing sperm characteristics, including motility, morphology, acrosome integrity, viability and membrane integrity. A total number of 42 ejaculates were collected using the artifi cial vagina from 4 Akkaraman rams and 10 replicates of the ejaculates were diluted with a Tris-based extender containing additives and no additives as control. GSSG (5 mM, BSA (20 mg/ml, cysteine (10 mM and lycopene (800 μg showed more positive effects than other concentrations of the supplements and controls in protecting sperm characteristics after the freezing-thawing process (P < 0.001. Many aspects of sperm protection, e.g. sperm motility, viability and membrane stabilisation of the sperm cells during relative cryopreservation, are the key factors in determining the preservation of sperm function. The results of this study provide a new approach to the cryopreservation of sperm from rams and related breeds, and thereby contribute to the improvement of these breeds for the world sheep industry.

  9. Comparative effect of different concentrations of hydro-ethanolic extract of chamomile on freeze-thawn semen quality of rams

    Directory of Open Access Journals (Sweden)

    hossein daghighkia

    2017-04-01

    Full Text Available Oxidative stress during freeze-thawing process causes reduction in motility, viability, membrane functions and finally sperm fertility. The aim of this study was to determine the effect of Chamomile extract as natural antioxidant on quality of cryopreserved ram sperm. In this study semen was collected from five mature rams twice a week using an artificial vagina and the ejaculates were pooled equally in order to eliminate the individual effects. Different levels of extract of Chamomile (0, 50, 66.66, 100 and 200 ml/dl of diluent solution were added to diluent based tris-egg yolk. After cooling, filling and sealing of the samples, they were frozen with nitrogen vapor and immersed in liquid nitrogen and were stored until evaluation time. After thawing, results showed that addition of 66.66 ml/dl of extract increased total motility, progressive motility, curvilinear velocity, straight–line velocity, linearity, viability and plasma membrane integrity of sperm compared to the control and other treatment groups (p

  10. Effect of suction on the mechanical characteristics of uniformly compacted rammed earth

    Science.gov (United States)

    El Hajjar, A.; Chauhan, P.; Prime, N.; Plé, O.

    2018-04-01

    Rammed earth, in the current environmental situation, is an alternative construction technique which can help in reducing energy and raw material consumption owing to its “sustainable” characteristics. To fully understand its behavior and properties, recent scientific investigations consider it as a compacted unsaturated material with suction as its one of the main sources of strength. Eathern constructions face, over their lifetime, variations in the suction state which have a significant impact on their mechanical characteristics. In the present contribution, unconfined compression tests are performed, with and without unload-reload cycles, on homogeneously compacted samples subjected to various suction conditions. This study shows that both the unconfined compressive strength and Young modulus reduce with the reduction of suction states. Suction also seems to influence the amount of plastic strains and damage phenomenon. Indeed, the soils analyzed are slightly active and shows both plasticity behavior and damage phenomenon.

  11. Thermal Hydraulic Integral Effect Tests for Pressurized Water Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Baek, W. P.; Song, C. H.; Kim, Y. S. and others

    2005-02-15

    The objectives of the project are to construct a thermal-hydraulic integral effect test facility and to perform various integral effect tests for design, operation, and safety regulation of pressurized water reactors. During the first phase of this project (1997.8{approx}2002.3), the basic technology for thermal-hydraulic integral effect tests was established and the basic design of the test facility was accomplished: a full-height, 1/300-volume-scaled full pressure facility for APR1400, an evolutionary pressurized water reactor that was developed by Korean industry. Main objectives of the present phase (2002.4{approx}2005.2), was to optimize the facility design and to construct the experimental facility. We have performed following researches: 1) Optimization of the basic design of the thermal-hydraulic integral effect test facility for PWRs - ATLAS (Advanced Thermal-hydraulic Test Loop for Accident Simulation) - Reduced height design for APR1400 (+ specific design features of KSNP safety injection systems) - Thermal-hydraulic scaling based on three-level scaling methodology by Ishii et al. 2) Construction of the ATLAS facility - Detailed design of the test facility - Manufacturing and procurement of components - Installation of the facility 3) Development of supporting technology for integral effect tests - Development and application of advanced instrumentation technology - Preliminary analysis of test scenarios - Development of experimental procedures - Establishment and implementation of QA system/procedure.

  12. Effect of Three Days Storage of Coated Spermatozoa at Cooling and Adding Seminal Plasma on Ram Fertility

    Directory of Open Access Journals (Sweden)

    Alireza Vaferi

    2016-08-01

    Full Text Available Introduction Artificial insemination (AI has only been used as a supplement to natural mating. AI, when used in conjunction with accurate progeny testing schemes, can substantially increase the rate of genetic progress compared with that of natural service. Moreover, the use of AI causes the limitation of the transmitted diseases. Cervical insemination with frozen-thawed ram semen has not been widely adopted, probably because of the relative poor fertility obtained. Thus using fresh and diluted semen is only approach for performing AI. AI is currently limited by the poor fertility achieved after cervical insemination with the storage of liquid semen at sub-ambient temperature. The success of this procedure in sheep is restricted by the short length of time that ram sperm can be stored in a liquid state. Moreover, the effect of cooling on sperm differs depending on species. It is also well known that ram spermatozoa are more sensitive to cold-shock stress than those of other species. Seminal plasma, as physiological secretion, is a complex mixture of secretions originating from testis, epididymis and accessory sex glands which is mixed with epididymal sperm at ejaculation; it serves as the carrier of sperm to the female genital tract. This mixture contains numerous factors such as organic and nonorganic material which play an important role in the final maturation of the spermatozoa through hormonal, enzymatic and surface-modifying events. During natural mating, a mechanism may be activated to separate spermatozoa from seminal plasma. After being ejaculated into the vagina, sperm swim through cervical mucus and enter the uterus within minutes (>30 min; cervical mucus acts as a barrier for seminal plasma. In the artificial insemination industry, seminal plasma with all the useful and harmful components is not removed from semen and is in contact with sperm throughout cooling, freezing and storage. On the other hand, it was demonstrated that the

  13. Effect of physical property of supporting media and variable hydraulic loading on hydraulic characteristics of advanced onsite wastewater treatment system.

    Science.gov (United States)

    Sharma, Meena Kumari; Kazmi, Absar Ahmad

    2015-01-01

    A laboratory-scale study was carried out to investigate the effects of physical properties of the supporting media and variable hydraulic shock loads on the hydraulic characteristics of an advanced onsite wastewater treatment system. The system consisted of two upflow anaerobic reactors (a septic tank and an anaerobic filter) accommodated within a single unit. The study was divided into three phases on the basis of three different supporting media (Aqwise carriers, corrugated ring and baked clay) used in the anaerobic filter. Hydraulic loadings were based on peak flow factor (PFF), varying from one to six, to simulate the actual conditions during onsite wastewater treatment. Hydraulic characteristics of the system were identified on the basis of residence time distribution analyses. The system showed a very good hydraulic efficiency, between 0.86 and 0.93, with the media of highest porosity at the hydraulic loading of PFF≤4. At the higher hydraulic loading of PFF 6 also, an appreciable hydraulic efficiency of 0.74 was observed. The system also showed good chemical oxygen demand and total suspended solids removal efficiency of 80.5% and 82.3%, respectively at the higher hydraulic loading of PFF 6. Plug-flow dispersion model was found to be the most appropriate one to describe the mixing pattern of the system, with different supporting media at variable loading, during the tracer study.

  14. Effect of adaptation and heat stress on reproductive performances of fat-tail Awassi rams in eastern mediterranean

    International Nuclear Information System (INIS)

    Abi Saab, S.; Darwish, W.Y.; Aad, P.; Sleiman, F.T.; Kallassy, N.; Aad, Y.

    2011-01-01

    The Awassi fat-tail sheep is desired in the Middle East and Sahara for its hardiness and resistance. In this region, the adaptability of Awassi rams to elevated heat stress is controversial. The objective of this study was to assess the effect of ambient or testicular 43 deg C heat on semen characteristics. 12 Awassi rams of 1.2 to 2 years were allowed an initial adaptation period (P0), followed by two experimental phases (P1 and P2), each including a period of heat stress (HS1 and HS2) followed by a period of recovery from heat stress (R1and R2). Heat stress conditions were considered when ambient temperature (Group 2) or testicular environment (Group 3) reached 42 to 44 deg C. Control animals (Group 1) were exposed to ambient environmental conditions. Temperature-humidity index (THI) as a relationship of ambient temperature, wet and dry humidity effect along with respiration and pulse rate, body temperature and live body weight (BW) were measured weekly as adaptation parameters. Reproductive parameters assessed included scrotum circumference and testicular volume measured twice per heat stress period, whereas semen volume density,concentration and motility were measured twice weekly. Data were analyzed using the mixed procedure of SAS under a time series analysis model, with treatment and time nested within period as main effects, and treatment by time within period as interaction terms. Treatment means were separated using Fisher protected LSD. Results showed a THI of 25.7 during therest periods (R1 and R2), 30 during HS1 and 28 during HS2. BW decreased with ambient stress, whereas respiration rate increased during heat stress periods (HS1 and HS2). Testes volume decreased with both ambient and testicular heat stress, whereas testicular circumference was not affected by these conditions. Semen concentration decreased whereas semen volume increased with ambient but not testicular heat stress. Spermatozoa abnormalities increased in R1 following heat stress (HS1

  15. Thermal Hydraulic Integral Effect Tests for Pressurized Water Reactors

    International Nuclear Information System (INIS)

    Baek, Won Pil; Song, C. H.; Kim, Y. S.

    2007-02-01

    The objectives of the project are to construct a thermal-hydraulic integral effect test facility and to perform the tests for design, operation, and safety regulation of pressurized water reactors. In the first phase of this project (1997.8∼2002.3), the basic technology for thermal-hydraulic integral effect tests was established and the basic design of the test facility was accomplished. In the second phase (2002.4∼2005.2), an optimized design of the ATLAS (Advanced Thermal-hydraulic Test Loop for Accident Simulation) was established and the construction of the facility was almost completed. In the third phase (2005.3∼2007.2), the construction and commission tests of the ATLAS are to be completed and some first-phase tests are to be conducted

  16. The effect of cargo on the crush loading of RAM transportation packages in ship collisions

    International Nuclear Information System (INIS)

    Radloff, H.D.; Ammerman, D.J.

    1998-03-01

    Recent intercontinental radioactive material shipping campaigns have focused public and regulatory attention on the safety of transport of this material by ocean-going vessels. One major concern is the response of the vessel and onboard radioactive material (RAM) packages during a severe ship-to-ship collision. These collisions occur at velocities less than the velocity obtained in the Type B package regulatory impact event and the bow of the striking ship is less rigid than the unyielding target used in those tests (Ammerman and Daidola, 1996). This implies that ship impact is not a credible scenario for damaging the radioactive material packages during ship collisions. It is possible, however, for these collisions to generate significant amounts of crush force by the bow of the impacting ship overrunning the package. It is the aim of this paper to determine an upper bound on the magnitude of this crush force taking into account the strength of the radioactive material carrying vessel and any other cargo that may be stowed in the same hold as the radioactive material

  17. Effects of model layer simplification using composite hydraulic properties

    Science.gov (United States)

    Kuniansky, Eve L.; Sepulveda, Nicasio; Elango, Lakshmanan

    2011-01-01

    Groundwater provides much of the fresh drinking water to more than 1.5 billion people in the world (Clarke et al., 1996) and in the United States more that 50 percent of citizens rely on groundwater for drinking water (Solley et al., 1998). As aquifer systems are developed for water supply, the hydrologic system is changed. Water pumped from the aquifer system initially can come from some combination of inducing more recharge, water permanently removed from storage, and decreased groundwater discharge. Once a new equilibrium is achieved, all of the pumpage must come from induced recharge and decreased discharge (Alley et al., 1999). Further development of groundwater resources may result in reductions of surface water runoff and base flows. Competing demands for groundwater resources require good management. Adequate data to characterize the aquifers and confining units of the system, like hydrologic boundaries, groundwater levels, streamflow, and groundwater pumping and climatic data for recharge estimation are to be collected in order to quantify the effects of groundwater withdrawals on wetlands, streams, and lakes. Once collected, three-dimensional (3D) groundwater flow models can be developed and calibrated and used as a tool for groundwater management. The main hydraulic parameters that comprise a regional or subregional model of an aquifer system are the hydraulic conductivity and storage properties of the aquifers and confining units (hydrogeologic units) that confine the system. Many 3D groundwater flow models used to help assess groundwater/surface-water interactions require calculating ?effective? or composite hydraulic properties of multilayered lithologic units within a hydrogeologic unit. The calculation of composite hydraulic properties stems from the need to characterize groundwater flow using coarse model layering in order to reduce simulation times while still representing the flow through the system accurately. The accuracy of flow models with

  18. A Theory for Stability and Buzz Pulsation Amplitude in Ram Jets and an Experimental Investigation Including Scale Effects

    Science.gov (United States)

    Trimpi, Robert L

    1956-01-01

    From a theory developed on a quasi-one-dimensional-flow basis, it is found that the stability of the ram jet is dependent upon the instantaneous values of mass flow and total pressure recovery of the supersonic diffuser and immediate neighboring subsonic diffuser. Conditions for stable and unstable flow are presented. The theory developed in the report is in agreement with the experimental data of NACA-TN-3506 and NACA-RM-L50K30. A simple theory for predicting the approximate amplitude of small pressure pulsation in terms of mass-flow decrement from minimum-stable mass flow is developed and found to agree with experiments. Cold-flow tests at a Mach number of 1.94 of ram-jet models having scale factors of 3.15:1 and Reynolds number ratios of 4.75:1 with several supersonic diffuser configurations showed only small variations in performance between geometrically similar models. The predominant variation in steady-flow performance resulted from the larger boundary layer in the combustion chamber of the low Reynolds number models. The conditions at which buzz originated were nearly the same for the same supersonic diffuser (cowling-position angle) configurations in both large and small diameter models. There was no appreciable variation in stability limits of any of the models when the combustion-chamber length was increased by a factor of three. The unsteady-flow performance and wave patterns were also similar when considered on a reduced-frequency basis determined from the relative lengths of the model. The negligible effect of Reynolds number on stability of the off-design configurations was not anticipated in view of the importance of boundary layer to stability, and this result should not be construed to be generally applicable. (author)

  19. effective hydraulic conductivity for a soil of variable pore size

    African Journals Online (AJOL)

    eobe

    Keywords: hydraulic conductivity, soil, infiltration, permeability, water. 1. INTRODUCTION. INTRODUCTION. INTRODUCTION. Accurate determination of hydraulic conductivity is very crucial for infiltration and runoff estimation. Factors which affect water infiltration in the soil include hydraulic conductivity, wetting front and soil.

  20. The Effect of Central American Smoke Aerosols on the Air Quality and Climate over the Southeastern United States: First Results from RAMS-AROMA

    Science.gov (United States)

    Wang, J.; Christopher, S. A.; Nair, U. S.; Reid, J.; Prins, E. M.; Szykman, J.

    2004-12-01

    Observation shows that smoke aerosols from biomass burning activities in Central America can be transported to the Southeastern United States (SEUS). In this study, the Regional Atmospheric Modeling System - Assimilation and Radiation Online Modeling of Aerosols (RAMS-AROMA) is used to investigate the effect of transported smoke aerosols on climate and air quality over the SEUS. AROMA is an aerosol transport model with capabilities of online integration of aerosol radiation effects and online assimilation of satellite-derived aerosol and emission products. It is assembled within the RAMS, so two-way interactions between aerosol fields and other meteorology fields are achieved simultaneously during each model time step. RAMS-AROMA is a unique tool that can be used to examine the aerosol radiative impacts on the surface energy budget and atmospheric heating rate and to investigate how atmospheric thermal and dynamical processes respond to such impacts and consequently affect the aerosol distribution (so called feedbacks). First results regarding air quality effects and radiative forcing of transported smoke aerosols will be presented from RAMS-AROMA based on assimilation of smoke emission products from the Fire Locating and Modeling of Burning Emissions (FLAMBE) project and aerosol optical thickness data derived from the MODIS instrument on the Terra and Aqua satellites. Comparisons with PM2.5 data collected from the EPA observation network and the aerosol optical thickness data from the DOE Atmosphere Radiation Measurements in the Southern Great Plains (ARM SGP) showed that RAMS-AROMA can predict the timing and spatial distribution of smoke events very well, with an accuracy useful for air quality forecasts. The smoke radiative effects on the surface temperature and atmospheric heating rate as well as their feedbacks will also be discussed.

  1. Effects of fines content on hydraulic conductivity and morphology of laterite soil as hydraulic barrier

    Science.gov (United States)

    Bello Yamusa, Yamusa; Yunus, Nor Zurairahetty Mohd; Ahmad, Kamarudin; Rahman, Norhan Abd; Sa'ari, Radzuan

    2018-03-01

    Laterite soil was investigated to find out the effects of fines content and to identify the micro-structural and molecular characteristics to evaluate its potentiality as a compacted soil landfill liner material. Tests were carried out on natural soil and reconstituted soil by dry weight of soil samples to determine the physical and engineering properties of the soil. All tests were carried out on the samples by adopting the British Standard 1377:1990. The possible mechanisms that contributed to the clay mineralogy were analyzed using spectroscopic and microscopic techniques such as field emission scanning electron microscopy (FESEM), energy-dispersive X-ray (EDX) and X-ray diffractometry (XRD). The laterite soil was found to contain kaolinite as the major clay minerals. A minimum of 50% fines content of laterite soil met the required result for hydraulic barriers in waste containment facilities.

  2. THE EFFECT OF SEMEN WASHING AND SOYBEAN LECITHIN LEVEL ON MOTILITY AND VIABILITY OF RAM SPERMATOZOA STORED AT 5⁰C

    Directory of Open Access Journals (Sweden)

    S. Salmin

    2014-10-01

    Full Text Available The objectives of this reserarch were to study the effect of semen washing and soybean lecithinlevel on the motility and viability of ram spermatozoa stored at 5⁰C. Semen was collected from threemature rams by artificial vagina. Semen was evaluated by macroscopic and microscopic. Semen wasdivided into ten tubes, the semen of first five tubes was unwashed (W0 and diluted with extender 0%,1%, 2%, 3% and 4% soybean lecithin (L0, L1, L2, L3 and L4. Semen of another five tubes werewashed (W1 then each diluted with similar extender levels. The diluted semen samples were stored at5⁰C and the sperm motility and viability were evaluated each day. The interaction of the semen washingand soybean lecithin levels were no significant differences (P>0.05 but the single factor of soybeanlecithin level was significant differeNces (P<0.05 and the single factor of semen washing were nosignificant differences (P>0.05 on progressive motility and viability of ram sperm.The best extenderwas 3% soybean lecithin (L3 with the percentage of ram sperm progressive motility was 63.18 ± 3.61%and viability was 71.76±2.32%.

  3. SQL-RAMS

    Science.gov (United States)

    Alfaro, Victor O.; Casey, Nancy J.

    2005-01-01

    SQL-RAMS (where "SQL" signifies Structured Query Language and "RAMS" signifies Rocketdyne Automated Management System) is a successor to the legacy version of RAMS -- a computer program used to manage all work, nonconformance, corrective action, and configuration management on rocket engines and ground support equipment at Stennis Space Center. The legacy version resided in the File-Maker Pro software system and was constructed in modules that could act as standalone programs. There was little or no integration among modules. Because of limitations on file-management capabilities in FileMaker Pro, and because of difficulty of integration of FileMaker Pro with other software systems for exchange of data using such industry standards as SQL, the legacy version of RAMS proved to be limited, and working to circumvent its limitations too time-consuming. In contrast, SQL-RAMS is an integrated SQL-server-based program that supports all data-exchange software industry standards. Whereas in the legacy version, it was necessary to access individual modules to gain insight into a particular workstatus document, SQL-RAMS provides access through a single-screen presentation of core modules. In addition, SQL-RAMS enables rapid and efficient filtering of displayed statuses by predefined categories and test numbers. SQL-RAMS is rich in functionality and encompasses significant improvements over the legacy system. It provides users the ability to perform many tasks, which in the past required administrator intervention. Additionally, many of the design limitations have been corrected, allowing for a robust application that is user centric.

  4. COST EFFECTIVE AND HIGH RESOLUTION SUBSURFACE CHARACTERIZATION USING HYDRAULIC TOMOGRAPHY

    Science.gov (United States)

    2017-08-01

    objective of this project is to provide the DoD and its remediation contractors with the HT technology for delineating the spatial distribution of...STATEMENT Approved for public release; distribution is unlimited 13. SUPPLEMENTARY NOTES 14. ABSTRACT Hydraulic Tomography ( HT ) is a high-resolution...performance of subsurface remedial actions at environmental sites. The good technical performance and cost-effectiveness of HT have been demonstrated in

  5. Protective effect of hypoxia in the ram testis during single and split-dose X-irradiation

    International Nuclear Information System (INIS)

    Vliet, J. van; Wensing, C.J.G.; Bootsma, A.L.; Peperzeel, H.A. van; Schipper, J.

    1988-01-01

    Spertogonial stem-cell survival in the ram was studied after single (6Gy) and split-dose X-irradiation both under normal and hypoxic conditions. Hypoxia was induced by inflation of an occluder implanted around the testicular artery. The occluders were inflated about 10 min before irradiation and deflated immediately after. Stem-cell survival was measured at 5 or 7 weeks after irradiation by determination of the Repopulation Index (RI) in histological testis sections. The RI-values after fractionated irradiation were only half those after single dose irradiation. Hypoxia had a protective effect on the stem-cell survival. After split-dose irradiation under hypoxic conditions two times more stem cells survived than under normal oxic conditions; the RI-values increased from 34% (oxic) to 68% (hypoxic). This effect of hypoxia was also found after single dose irradiation where the RI-values increased from 68% (oxic) to 84% (hypoxic). The development of the epithelium in repopulated tubules was also studied. Under hypoxia, a significantly higher fraction of tubules with complete epithelium was found after single (38 vs. 4%) as well as after split-dose irradiation (12 vs. 0%)

  6. Appetitive and Consummatory Sexual Behaviors of Rams Treated with Exogenous Testosterone and Exposed to Anestrus Dorper Ewes: Efficacy of the Male Effect.

    Science.gov (United States)

    Tejada, Luz M; Meza-Herrera, Cesar A; Rivas-Muñoz, Raymundo; Rodríguez-Martínez, Rafael; Carrillo, Evaristo; Mellado, Miguel; Véliz-Deras, Francisco G

    2017-04-01

    We determine whether Dorper rams treated with testosterone in the sexual resting season trigger both appetitive and consummatory sexual behaviors and sexual and reproductive outcomes in anestrous ewes at 26° North during March-April. Dorper rams (n = 12, 2.5 years) were randomly divided prior to mating in two groups: GT (treated group; n = 6), treated with testosterone propionate (25 mg i.m. every 3 days × 3 weeks) and GC (control group; n = 6), treated with saline. Thereafter, adult anovulatory Dorper ewes (n = 61) were exposed to the GT-rams while the other group (n = 60) was exposed to the GC-rams. Ram's appetitive sexual behavior was similar (50 %) in both groups, yet the GT-rams exerted 100 % of the consummatory sexual behavior. Sexual and reproductive outcomes of the anestrus females exposed to both male groups considered two phases: 0-15 and 16-25 days from exposure to males. Involved variables were: ewes in estrus, ewes ovulating, duration of estrus, pregnant ewes, and lambed ewes. All the average variables favored those ewes exposed to GT-males: ewes in estrus: 85 versus 40 %; ewes ovulating: 80 versus 53 %; duration of estrus: 37 versus 25 h; pregnant ewes: 60 versus 31 %, and lambed ewes: 57 versus 31 %. Results confirm that adult Dorper rams treated with exogenous testosterone had improved consummatory sexual behavior and induced increased ovulation and pregnancy rates when exposed to anestrus ewes. This feasible and inexpensive testosterone-based protocol through the male effect also enhanced both sexual and reproductive outcomes in previously anestrous Dorper ewes during the natural out-of-season. Results are important to speed up reproductive performance of sheep during the natural anestrous season at this latitude, while also they embrace interesting outcomes from a comparative sexual behavior stand point.

  7. The influence of hydraulic conditions on coagulation process effectiveness

    Directory of Open Access Journals (Sweden)

    Sambor Aleksandra

    2017-01-01

    Full Text Available This paper presents the impact that small changes in the hydraulic installation between the flocculation chamber and the sedimentation tanks have on coagulation process effectiveness. This study has shown significant improvements in the parameters of the treated water. The research was conducted in two treatment systems: reference and test, in order to compare the changes that were introduced in the time period between January and May 2016. The hydraulic conditions between the flocculation chamber and the sedimentation tank were changed in the test system, leaving the reference system unchanged for comparative purposes. The height-wise positioning of the sedimentation tank relative to the flocculation chamber resulted in a formation of a cascade at the flocculation chamber drain at a height of 0.60m. Air was therefore introduced into the water, forming an air-water mixture, which disturbed the flow between the devices. It was found that floc transported by the pipeline was broken down, which hampered sedimentation in the sedimentation tank. This was confirmed by the analysis of chosen parameters from treated water. After changes in the hydraulic system, changes in water turbidity were noticed, indicating an increase in post-coagulation suspension separation effectiveness. Consequently, an increase in organic carbon removal was found relative to the reference system. This change influenced changes in UV254 absorbance to a much lesser extent.

  8. The influence of hydraulic conditions on coagulation process effectiveness

    Science.gov (United States)

    Sambor, Aleksandra; Ferenc, Zbigniew

    2017-11-01

    This paper presents the impact that small changes in the hydraulic installation between the flocculation chamber and the sedimentation tanks have on coagulation process effectiveness. This study has shown significant improvements in the parameters of the treated water. The research was conducted in two treatment systems: reference and test, in order to compare the changes that were introduced in the time period between January and May 2016. The hydraulic conditions between the flocculation chamber and the sedimentation tank were changed in the test system, leaving the reference system unchanged for comparative purposes. The height-wise positioning of the sedimentation tank relative to the flocculation chamber resulted in a formation of a cascade at the flocculation chamber drain at a height of 0.60m. Air was therefore introduced into the water, forming an air-water mixture, which disturbed the flow between the devices. It was found that floc transported by the pipeline was broken down, which hampered sedimentation in the sedimentation tank. This was confirmed by the analysis of chosen parameters from treated water. After changes in the hydraulic system, changes in water turbidity were noticed, indicating an increase in post-coagulation suspension separation effectiveness. Consequently, an increase in organic carbon removal was found relative to the reference system. This change influenced changes in UV254 absorbance to a much lesser extent.

  9. Effects of electrodes on the properties of sol-gel PZT based capacitors in FeRAM

    Science.gov (United States)

    Zhang, Ming-Ming; Jia, Ze; Ren, Tian-Ling

    2009-05-01

    The effects of electrodes on the properties of capacitors applied in ferroelectric random access memories (FeRAM) are investigated in this work. Pt and Ir are used as bottom and top electrodes (BE and TE), respectively, in sol-gel Pb(Zr xTi 1-x)O 3 (PZT) based capacitors. Bottom electrodes are found to play a dominant role in the properties of PZT films and capacitors. Capacitors using Pt as bottom electrode have larger remnant polarization (2Pr) than those using Ir which may result from the different orientations of PZT films. The higher Schottky barrier, more dense film and smaller roughness are believed to be the reasons for the better leakage performance of capacitors using Pt as bottom electrodes. Different vacancies types and interface conditions are believed to be the main reasons for the better fatigue (less than 10% initial 2Pr loss after 10 11 fatigue cycles) and better imprint properties of TE/PZT/Ir capacitors. Top electrodes are found to have smaller impact on the properties of capacitors compared with bottom electrodes. A decrease in 2Pr is found when Ir is used as top electrode instead of Pt for PZT/Pt, which is believed to be caused by the stress resulting from lattice mismatch. The different thermal processes that top and bottom electrodes suffered are believed to be the reason for the different impacts they have on capacitors.

  10. Effect of the infection with the nematode Haemonchus contortus (Strongylida: Trichostrongylidae on the haematological, biochemical, clinical and reproductive traits in rams

    Directory of Open Access Journals (Sweden)

    Mariem Rouatbi

    2016-08-01

    Full Text Available This study aimed to investigate the effect of Haemonchus contortus infection on rams’ haematological, biochemical and clinical parameters and reproductive performances. A total number of 12 Barbarine rams (control and infected were included in the experiment. The infected group received 30 000 H. contortus third-stage larvae orally. Each ram’s ejaculate was immediately evaluated for volume, sperm cell concentration and mortality rate. At the end of the experiment (day 82 post-infection, which lasted 89 days, serial blood samples were collected in order to assess plasma testosterone and luteinising hormone (LH concentrations. There was an effect of time, infection and their interaction on haematological parameters (p < 0.001. In infected rams, haematocrit, red blood cell count and haemoglobin started to decrease from 21 days post-infection. There was an effect of time and infection for albumin. For total protein, only infection had a statistically significant effect. For glucose, only time had a statistically significant effect. Concentrations were significantly lower in infected rams compared to control animals. A significant effect of infection and time on sperm concentrations and sperm mortality was observed. The effect of infection appears in time for sperm concentrations at days 69 and 76 post-infection. Sperm mortality rate was significantly higher in infected animals at day 46 post-infection when compared to control group (p < 0.05. Finally, plasma testosterone traits (average concentration, cumulated levels during the sampling period and pulse frequency were depressed in infected rams when compared to control counterparts; none of these endocrine traits were affected for plasma LH.

  11. Effect of thymol and carvacrol on nutrient digestibility in rams fed high or low concentrate diets.

    Science.gov (United States)

    Zamiri, M J; Azizabadi, E; Momeni, Z; Rezvani, M R; Atashi, H; Akhlaghi, A

    2015-01-01

    Published data on the effects of essential oils (EO) on in vivo nutrient digestibility in sheep are contradictory. In 2 experiments, the effect of thymol and carvacrol on nutrient digestibility was studied in sheep fed with high (70%) or low (52%) concentrate diets, using incomplete Latin Square designs. The essential oils were mixed with the concentrate portion of the diet at the rate of 0.0, 0.3, or 0.6 g per kg dry matter (DM) diet. Supplementation of thymol had no significant effect on digestibility of dry matter (DM), organic matter (OM), crude protein (CP) and acid detergent fiber (ADF). The main effect of thymol on neutral detergent fiber (NDF) and ether extract (EE) digestibility and on nitrogen balance (NB) was significant (Pdigestibility. The main effect of carvacrol on ruminal ammonia levels and NB was significant, but within each level of dietary concentrate no significant differences were observed in ammonia levels and NB. Inclusion of 0.3 g/kg diet DM of carvacrol or thyme was more effective than 0.6 g/kg diet DM in terms of NB but neither dose affected nutrient digestibility. Future research should determine the long-term effects of essential oils on digestibility and performance in sheep, before recommendation can be made for their use under practical husbandry conditions.

  12. The effects of gelatin supplementation prior to cooling on ram semen quality and fertility.

    Science.gov (United States)

    The physical and chemical characteristics of gelatin have been used to justify its inclusion in extenders to preserve the sperm quality and improve results of cervical artificial insemination with cooled semen. The objective of this study was to evaluate the effect of gelatin supplementation in cool...

  13. Sharma, Dr Ram Swaroop

    Indian Academy of Sciences (India)

    Home; Fellowship. Fellow Profile. Elected: 1989 Section: Earth & Planetary Sciences. Sharma, Dr Ram Swaroop Ph.D. (Basel), FNA. Date of birth: 10 July 1937. Specialization: Metamorphic Petrology, Mineralogy and Precambrian Geology Address: 70/36, Pratapnagar, Sector 7, Sanganer (RHB), Jaipur 302 033, Rajasthan

  14. Effect of Hydraulic Pressure on Warm Hydro Mechanical Deep Drawing of Magnesium Alloy Sheet

    Science.gov (United States)

    Liu, Wei; Wu, Linzhi; Yuan, Shijian

    The uniaxial tensile test and hydraulic bulging test of AZ31 magnesium alloy sheets were applied to study the influence of temperature on the material properties and obtain the forming limit curves at different temperatures. Numerical simulations of warm hydro mechanical deep drawing were carried out to investigate the effect of hydraulic pressure on the formability of a cylindrical cup, and the simplified hydraulic pressure profiles were used to simulate the loading procedure of hydraulic pressure. The optimal hydraulic pressure at different temperatures were given and verified by experimental studies at temperature 100°C and 170V.

  15. The effect of freeze-thaw cycles on the hydraulic conductivity of compacted clay

    International Nuclear Information System (INIS)

    Waite, D.; Anderson, L.; Caliendo, J.; McFarland, M.

    1994-01-01

    A study was conducted to investigate the detrimental effects of freeze-thaw on the hydraulic conductivity of compacted clay. The purpose of this study was to determine the effect that molding water content has on the hydraulic conductivity of a compacted clay soil that is subjected to freeze-thaw cycles, and to determine the relationship between the number of freeze-thaw cycles and the hydraulic conductivity of the compacted clay soil. Clay soils compacted and frozen wet of optimum experienced an increase in hydraulic conductivity of approximately 140 fold. The hydraulic conductivity of clay compacted dry of optimum increased ten fold. These results are consistent with recent research which suggests that clay compacted wet of optimum experiences large increases in hydraulic conductivity while the hydraulic conductivity of clay compacted dry of optimum increases to a lesser extent. 12 refs., 9 figs

  16. Effect of season on scrotal circumference, semen characteristics, seminal plasma composition and spermatozoa motility during liquid storage in INRA180 rams.

    Science.gov (United States)

    Benmoula, Anass; Badi, Abdelmoughit; El Fadili, Moussa; El Khalil, Kaoutar; Allai, Larbi; El Hilali, Abderaouf; El Amiri, Bouchra

    2017-05-01

    The present study was undertaken to assess the effect of seasons on scrotal circumference, semen characteristics, seminal plasma composition, and sperm motility during liquid storage of INRA180 rams. The semen was collected from five mature INRA180 rams (2-3 years of age) during one year (from April 2014 to March 2015). Scrotal circumferences, semen characteristics, some biochemical parameters of seminal plasma were evaluated. Immediately after collection and evaluation, the semen was pooled and extended in skim milk (SM) at 15°C to reach 0.8×109 spermatozoa/ml. Thereafter, samples were evaluated at different storage times (0, 8, and 24h). The results showed that scrotal circumference, semen quality and the concentration of total protein in seminal plasma were relatively constant during the year (P>0.05). However, total lipid and cholesterol concentrations increased significantly (P0.05). To conclude, the INRA180 rams have the ability to produce semen with high quality all over the year. The only parameters showing seasonal variations are cholesterol, total lipid, and progressive motility. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Room-Temperature Voltage Stressing Effects on Resistive Switching of Conductive-Bridging RAM Cells with Cu-Doped SiO2 Films

    Directory of Open Access Journals (Sweden)

    Jian-Yang Lin

    2014-01-01

    Full Text Available SiO2 or Cu-doped SiO2 (Cu:SiO2 insulating films combined with Cu or W upper electrodes were constructed on the W/Si substrates to form the conductive-bridging RAM (CB-RAM cells. The CB-RAMs were then subjected to a constant-voltage stressing (CVS at room temperature. The experimental results show that the room-temperature CVS treatment can effectively affect the current conduction behavior and stabilize the resistive switching of the memory cells. After the CVS, the current conduction mechanisms in the high resistance state during the set process of the Cu/Cu:SiO2/W cell can be changed from Ohm’s law and the space charge limited conduction to Ohm’s law, the Schottky emission, and the space charge limited conduction. Presumably, it is due to the breakage of the conduction filaments during the CVS treatment that the conduction electrons cannot go back to the back electrode smoothly.

  18. Effects of biochars on hydraulic properties of clayey soil

    Science.gov (United States)

    Zhen, Jingbo; Palladino, Mario; Lazarovitch, Naftali; Bonanomi, Giuliano; Battista Chirico, Giovanni

    2017-04-01

    Biochar has gained popularity as an amendment to improve soil hydraulic properties. Since biochar properties depend on feedstocks and pyrolysis temperatures used for its production, proper selection of biochar type as soil amendment is of great importance for soil hydraulic properties improvement. This study investigated the effects of eight types of biochar on physical and hydraulic properties of clayey soil. Biochars were derived from four different feedstocks (Alfalfa hay, municipal organic waste, corn residues and wood chip) pyrolyzed at two different temperatures (300 and 550 °C). Clayey soil samples were taken from Leone farm (40° 26' 15.31" N, 14° 59' 45.54" E), Italy, and were oven-dried at 105 °C to determine dry bulk density. Biochars were mixed with the clayey soil at 5% by mass. Bulk densities of the mixtures were also determined. Saturated hydraulic conductivities (Ks) of the original clayey soil and corresponding mixtures were measured by means of falling-head method. Soil water retention measurements were conducted for clayey soil and mixtures using suction table apparatus and Richards' plate with the pressure head (h) up to 12000 cm. van Genuchten retention function was selected to evaluate the retention characteristics of clayey soil and mixtures. Available water content (AWC) was calculated by field capacity (h = - 500 cm) minus wilting pointing (h = -12000 cm). The results showed that biochar addition decreased the bulk density of clayey soil. The Ks of clayey soil increased due to the incorporation of biochars except for waste and corn biochars pyrolyzed at 550 °C. AWC of soils mixed with corn biochar pyrolyzed at 300 °C and wood biochar pyrolyzed at 550 °C, increased by 31% and 7%, respectively. Further analysis will be conducted in combination of biochar properties such as specific surface area and total pore volume. Better understanding of biochar impact on clayey soil will be helpful in biochar selection for soil amendment and

  19. PREPARATION OF TEASER RAMS BY LATERAL DEVIATION OF PREPUCE AND PENIS

    OpenAIRE

    Rashid Ahmad

    2003-01-01

    For oestrus detection in sheep while in flocks, limited exposure is given to rams with tied apron in front of their prepucial opening. For better and un-feared use of rams for oestrus detection and for effect of , ram exposure on postpartum reproductive characteristics of ewes, rams before the attainment of puberty and those sexually mature (adult rams) were operated for lateral deviation of prepuce and penis. The operations were successful, no post operative complications were recorded and t...

  20. Effect of hydraulic retention time on continuous biocatalytic calcification reactor

    International Nuclear Information System (INIS)

    Isik, Mustafa; Altas, Levent; Kurmac, Yakup; Ozcan, Samet; Oruc, Ozcan

    2010-01-01

    High calcium concentrations in the wastewaters are problematic, because they lead to clogging of pipelines, boilers and heat exchangers through scaling (as carbonate, sulfate or phosphate precipitates), or malfunctioning of aerobic and anaerobic reactors. As a remedy to this problem, the industry typically uses chemical crystallization reactors which are efficient but often require complex monitoring and control and, as a drawback, can give rise to highly alkaline effluents. Biomineralization are emerging as alternative mechanisms for the removal of calcium from aqueous environments. Biocatalytic calcification reactors (BCR) utilize microbial urea hydrolysis by bacteria for the removal of calcium, as calcite, from industrial wastewater. Hydraulic retention time (HRT) effect on calcium removal was studied with a continuous feed BCR reactor treating a simulated pulp paper wastewater. Study showed that HRT is important parameter and HRT of 5-6 h is optimum for calcium removal from calcium-rich wastewaters.

  1. Effect of polyacrylamide on soil physical and hydraulic properties

    Science.gov (United States)

    Albalasmeh, Ammar; Gharaibeh, Mamoun; Hamdan, Enas

    2017-04-01

    The effect of polyacrylamide (PAM), as a soil conditioner, on selected soil physical and hydraulic properties (infiltration rate (f(t)), hydraulic conductivity (HC), soil moisture content, aggregate stability (AS), and soil aggregation) was studied. Two types of anionic PAM were used: Low molecular weight (LPAM) (1×105 g/mol) with medium charge density (33-43) and high molecular weight (HPAM) (1-6×106 g/mol) with medium charge density (33-43). Sandy loam soil was packed into plastic columns; PAM solutions at different concentrations (100, 250, 500, and 1000 mg L-1) were used every two weeks in four wetting and drying cycles. The highest infiltration rate value was 0.16 mm s-1 at 1000 mg/L low molecular weight PAM while the highest value of infiltration rate in high PAM molecular weight was 0.11 mm s-1 compared to the control (0.01 mm s-1). Soil HC was about 3.00 cm h-1 for LPAM at 1000 mg L-1 PAM, while the highest value for HPAM was about 2 cm h-1 for the same concentration, compared to the control. The amount of water that can be held by soil increased with the addition of PAM compared to the control. Differences in water content were more pronounced in LPAM compared to HPAM. The addition of LPAM increased aggregate stability proportional to PAM concentration. Moreover, 1000 mg L-1 produced the highest aggregate stability (19{%}) compared to HPAM and control (7{%} and 5{%}), respectively. As PAM concentration increased, the geometric mean diameter (GMD) increased for both PAM molecular weights compared to control (0.4 mm). At 1000 mg L-1 the GMD values were 0.88 mm and 0.79 mm for LPAM and HPAM, respectively. The addition of PAM improved soil physical and hydraulic properties, with an advantage to LPAM owing that to its ability to penetrate soil aggregates and therefore stabilizing them.

  2. Advanced energy saving hydraulic elevator

    Energy Technology Data Exchange (ETDEWEB)

    Garrido, A.; Sevilleja, J.; Servia, A.

    1993-08-24

    An hydraulic elevator is described comprising: a counterweighted elevator comprising a car, a counterweight, and a rope connecting the car and the counterweight; a ram having a first reaction surface for driving one of the car or the counterweight upwardly and a second reaction surface for driving one of the car or the counterweight downwardly; multiplier means for moving the car a distance greater than a stroke of the ram, the multiplier means connecting the ram to the counterweighted elevator, the multiplier means comprising: a first pulley; a second pulley; means for rigidly connecting the first and second pulley, the means having a length corresponding to a rise of the hydraulic elevator, the means attaching to the ram; and a pulley rope which: has a first end attaching to a first fixed point, extends about the first pulley, extends about the second pulley, and has a second end attaching to a second fixed point.

  3. Recovery of normal testicular temperature after scrotal heat stress in rams assessed by infrared thermography and its effects on seminal characteristics and testosterone blood serum concentration.

    Science.gov (United States)

    Alves, Maíra Bianchi Rodrigues; Andrade, André Furugen Cesar de; Arruda, Rubens Paes de; Batissaco, Leonardo; Florez-Rodriguez, Shirley Andrea; Oliveira, Bruna Marcele Martins de; Torres, Mariana Andrade; Lançoni, Renata; Ravagnani, Gisele Mouro; Prado Filho, Roberto Romano do; Vellone, Vinícius Silva; Losano, João Diego de Agostini; Franci, Celso Rodrigues; Nichi, Marcílio; Celeghini, Eneiva Carla Carvalho

    2016-08-01

    Reestablishment of testicular normal temperature after testicular heat stress is unknown and its effect varies widely. The aim of this study was to investigate the impact of scrotal insulation (IN) on testicular temperature and its relation to semen quality and testosterone blood serum concentration. For this, 33 rams were used; 17 submitted to IN for 72 hours (using bags involving the testes) and 16 not submitted to IN (control group). The experiment was performed between August and December 2013 in Pirassununga, Brazil (21°56″13″ South/47°28'24″ West). Seminal characteristics, testosterone blood serum concentration, rectal temperature (RT), respiratory frequency, scrotal superficies mean temperature (SSMT), and eye area mean temperature (EAMT) were analyzed 7 days before IN and 21, 35, 49, 63, and 90 days afterward. Scrotal superficies mean temperature and EAMT were measured by thermography camera FLIR T620. Testosterone was evaluated by radioimmunoassay. Analysis of variance was used to determine the main effects of treatment, time, and treatment-by-time interaction using PROC MIXED of SAS software adding command REPEAT. Pearson correlation test was used to verify correlation between SSMT, EAMT, RT, and respiratory frequency. Significant difference was considered when P ≤ 0.05. At the end of IN, SSMT was higher (P blood serum concentration was lesser in insulated rams (P = 0.03). Thus, the difference of 1.12 °C between RT and testicular temperature impacts semen quality and testosterone blood serum concentration. Moreover, this study shows that rams can recover testes temperature efficiently toward IN and that infrared thermography is an efficient tool to identify differences on SSMT. Copyright © 2016 Elsevier Inc. All rights reserved.

  4. Progesterone concentration and lambing rate of Karakul ewes treated with prostaglandin and GnRH combined with the ram effect during breeding and non-breeding seasons.

    Science.gov (United States)

    Mirzaei, A; Mohebbi-Fani, M; Omidi, A; Boostani, A; Nazifi, S; Mahmoodian-Fard, H R; Chahardahcherik, M

    2017-09-15

    The combination of ram effect with two injections of PGF 2α 10-days apart and the same protocol plus an additional injection of GnRH prior to the first injection of PGF 2α were examined in Karakul ewes during breeding and non-breeding seasons, respectively. Plasma progesterone (P 4 ) concentrations (to detect the presence of active corpus luteum), twin lambing, litter size and synchronization of lambing were evaluated. In each study 70 ewes (2-4 years old) were divided to a treatment (n = 40) and a control (n = 30) group. During the breeding season, on days -10 and 0 before ram release, the treatment group was injected intramuscularly with PGF 2α (D-Cloprostenol; 0.15 mg). During the non-breeding season, on day -15 before ram release the treatment group was injected with GnRH (buserelin; 4.2 μg) intramuscularly followed by two injections of PGF 2α on days -10 and 0. In both studies, the rams were released into the ewe flock after the second prostaglandin injection (day 0). Blood samples of ewes were collected on days -10, 0, 20 and 70 of the study in breeding season and on days -15, -10, 0, 20 and 70 during non-breeding season. The treatment group had higher P 4 concentrations compared to the control ewes on day 0 in the breeding season (5.80 ± 0.61 vs. 5.0 ± 0.93 ng/mL) and day -10 in the non-breeding season (3.50 ± 0.33 vs. 2.70 ± 0.35 ng/mL) though the differences were not significant (P > 0.05). Based on plasma P 4 concentrations (>1 ng/mL) on day 70, in the breeding season all control ewes (100%) and 91.9% of the treatment ewes were detected to have active corpus luteum (P = 0.09). An almost inverse result (90% vs. 97.5%; P = 0.2) was detected in the non-breeding season. The lambing rate was higher (P = 0.03) in the treatment group compared to the control ewes during the non-breeding season (90% vs. 70%), but tended to be lower (P = 0.07) in the breeding season (73% vs. 90%). Twin lambing rate was higher in the

  5. RAMS data collection under Arctic conditions

    International Nuclear Information System (INIS)

    Barabadi, Abbas; Tobias Gudmestad, Ove; Barabady, Javad

    2015-01-01

    Reliability, availability, maintainability and supportability analysis is an important step in the design and operation of production processes and technology. Historical data such as time between failures and time to repairs play an important role in such analysis. The data must reflect the conditions that equipment has experienced during its operating time. To have a precise understanding of the conditions experienced, all influence factors on the failure and repair processes of a production facility in Arctic environment need to be identified and collected in the database. However, there is a lack of attention to collect the effect of influence factors in the reliability, availability, maintainability and supportability database. Hence, the aim of this paper is to discuss the challenges of the available methods of data collection and suggest a methodology for data collection considering the effect of environmental conditions. Application of the methodology will make the historical RAMS data of a system more applicable and useful for the design and operation of the system in different types of operational environments. - Highlights: • The challenges related to use of the available RAMS data is discussed. • It is important to collect information about operational condition in RAMS data. • A methodology for RAMS data collection considering environment condition is suggested. • Information about influence factors will make the result of RAMS analysis more applicable

  6. HyRAM V1.0 User Guide

    Energy Technology Data Exchange (ETDEWEB)

    Groth, Katrina M. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Zumwalt, Hannah Ruth [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Clark, Andrew Jordan [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2016-03-01

    Hydrogen Risk Assessment Models (HyRAM) is a prototype software toolkit that integrates data and methods relevant to assessing the safety of hydrogen fueling and storage infrastructure. The HyRAM toolkit integrates deterministic and probabilistic models for quantifying accident scenarios, predicting physical effects, and characterizing the impact of hydrogen hazards, including thermal effects from jet fires and thermal pressure effects from deflagration. HyRAM version 1.0 incorporates generic probabilities for equipment failures for nine types of components, and probabilistic models for the impact of heat flux on humans and structures, with computationally and experimentally validated models of various aspects of gaseous hydrogen release and flame physics. This document provides an example of how to use HyRAM to conduct analysis of a fueling facility. This document will guide users through the software and how to enter and edit certain inputs that are specific to the user-defined facility. Description of the methodology and models contained in HyRAM is provided in [1]. This User’s Guide is intended to capture the main features of HyRAM version 1.0 (any HyRAM version numbered as 1.0.X.XXX). This user guide was created with HyRAM 1.0.1.798. Due to ongoing software development activities, newer versions of HyRAM may have differences from this guide.

  7. Effect of lecithin nanoliposome or soybean lecithin supplemented by pomegranate extract on post-thaw flow cytometric, microscopic and oxidative parameters in ram semen.

    Science.gov (United States)

    Mehdipour, Mahdieh; Daghigh Kia, Hossein; Nazari, Maryam; Najafi, Abouzar

    2017-10-01

    This investigation was carried out to study the effect of soybean lecithin 1.5% (wt/vol) (0, 2.5, 5 and 7.5 mg l -1 pomegranate extract (PE)) or PE-loaded lecithin nanoliposome (0, 2.5, 5 and 7.5 mg l -1 ) to Tris-based extender. Sperm motility (CASA), viability, membrane integrity (HOS test), abnormalities, mitochondrial activity, apoptosis status, lipid peroxidation, total antioxidant capacity (TAC)) and antioxidant activities (GPX, SOD) were investigated following freeze-thawing. No significant differences were detected in motility parameters, viability, membrane integrity, and mitochondria activity after thawing sperm between soybean lecithin and lecithin nanoliposomes. It was shown that PE5 significantly improved sperm total and progressive motility, membrane integrity, viability, mitochondria activity, TAC and reduced lipid peroxidation (malondialdehyde concentration). Moreover, the percentage of apoptotic sperm in PE5 extenders was significantly the lowest among other treatments. Sperm abnormalities, SOD and GPX were not affected by the antioxidant supplements. For apoptotic status, no differences were observed between soybean lecithin and lecithin nanoliposome. We showed that lecithin nanoliposome extender can be a beneficial alternative extender to protect ram sperm during cryopreservation without any adverse effects. It was also observed that regarding pomegranate concentration, PE5 can improve the quality of ram semen after thawing. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. Field study comparing the effect of hydraulic mixing on septic tank performance and sludge accumulation.

    Science.gov (United States)

    Almomani, Fares

    2016-01-01

    This study investigates the effect of hydraulic mixing on anaerobic digestion and sludge accumulation in a septic tank. The performance of a septic tank equipped with a hydraulic mixer was compared with that of a similar standard septic tank over a period of 10 months. The study was conducted in two phases: Phase-I--from May to November 2013 (6 months); Phase-II--from January to May 2014 (4 months). Hydraulic mixing effectively reduced the effluent biological oxygen demand (BOD) and total suspended solids, and reduced the sludge accumulation rate in the septic tank. The BOD removal efficiencies during Phase-II were 65% and 75% in the standard septic tank and a septic tank equipped with hydraulic mixer (Smart Digester™), respectively. The effect of hydraulic mixing reduced the rate of sludge accumulation from 0.64 cm/day to 0.27 cm/day, and increased the pump-out interval by a factor of 3.

  9. Effect of electrode and interface oxide on the property of ReRAM composed of Pr0.7Ca0.3MnO3

    International Nuclear Information System (INIS)

    Kaji, H; Kondo, H; Fujii, T; Arita, M; Takahashi, Y

    2010-01-01

    The current-voltage (I-V) characteristics of resistance random access memories (ReRAM) composed of the [top electrode] /Pr 0.7 Ca 0.3 MnO 3 (PCMO)/Pt structure were investigated by using Au, Pt, Ag, Cr, Mo and W needles as top electrodes against the PCMO layer. Reproducible resistance switching can be recognized in devices using Cr, Mo and W. Devices using Mo and W electrode showed two type of characteristics: (A) resistance change from low resistance state to high resistance state by positive bias voltage and (B) vice versa. Since the surfaces of these needles may be oxidized, we took account of the effect by the surface oxide. To check this assumption, we annealed the W needles and Mo needles in air and investigated I-V characteristics without the PCMO layer. As a result, the characteristic-(B) was classified to be induced by a surface oxide. Meanwhile, the characteristic-(A) is from PCMO. The existence of the interface oxide between top electrode and PCMO seems to decide the type of characteristics and to influence the reproducibility of the ReRAM property.

  10. Effect of gravel on hydraulic conductivity of compacted soil liners

    International Nuclear Information System (INIS)

    Shelley, T.L.; Daniel, D.E.

    1993-01-01

    How much gravel should be allowed in low-hydraulic-conductivity, compacted soil liners? To address this question, two clayey soils are uniformly mixed with varying percentages of gravel that, by itself, has a hydraulic conductivity of 170 cm/s. Soil/gravel mixtures are compacted and then permeated. Hydraulic conductivity of the compacted gravel/soil mixtures is less than 1 x 10 -7 cm/s for gravel contents as high as 50-60%. For gravel contents ≤ 60%, gravel content is not important: all test specimens have a low hydraulic conductivity. For gravel contents > 50-60%, the clayey soils does not fill voids between gravel particles, and high hydraulic conductivity results. The water content of the nongravel fraction is found to be a useful indicator of proper moisture conditions during compaction. From these experiments in which molding water content and compactive energy are carefully controlled, and gravel is uniformly mixed with the soil, it is concluded that the maximum allowable gravel content is approximately 50%

  11. PREPARATION OF TEASER RAMS BY LATERAL DEVIATION OF PREPUCE AND PENIS

    Directory of Open Access Journals (Sweden)

    Rashid Ahmad

    2003-07-01

    Full Text Available For oestrus detection in sheep while in flocks, limited exposure is given to rams with tied apron in front of their prepucial opening. For better and un-feared use of rams for oestrus detection and for effect of , ram exposure on postpartum reproductive characteristics of ewes, rams before the attainment of puberty and those sexually mature (adult rams were operated for lateral deviation of prepuce and penis. The operations were successful, no post operative complications were recorded and these rams exhibited normal libido and were found efficient for oestrus detection in ewes.

  12. Effects of biochar on hydraulic conductivity of compacted kaolin clay.

    Science.gov (United States)

    Wong, James Tsz Fung; Chen, Zhongkui; Wong, Annie Yan Yan; Ng, Charles Wang Wai; Wong, Ming Hung

    2018-03-01

    Compacted clay is widely used as capillary barriers in landfill final cover system. Recently, biochar amended clay (BAC) has been proposed as a sustainable alternative cover material. However, the effects of biochar on saturated hydraulic conductivity (k sat ) of clay with high degree of compaction is not yet understood. The present study aims to investigate the effects of biochar on k sat of compacted kaolin clay. Soil specimens were prepared by amending kaolin clay with biochar derived from peanut-shell at 0, 5 and 20% (w/w). The k sat of soil specimens was measured using a flexible water permeameter. The effects of biochar on the microstructure of the compacted clay was also investigated using MIP. Adding 5% and 20% of biochar increased the k sat of compacted kaolin clay from 1.2 × 10 -9 to 2.1 × 10 -9 and 1.3 × 10 -8 ms -1 , respectively. The increase in k sat of clay was due to the shift in pore size distribution of compacted biochar-amended clay (BAC). MIP results revealed that adding 20% of biochar shifted the dominant pore diameter of clay from 0.01-0.1 μm (meso- and macropores) to 0.1-4 μm (macropores). Results reported in this communication revealed that biochar application increased the k sat of compacted clay, and the increment was positively correlated to the biochar percentage. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Externally Verifiable Oblivious RAM

    Directory of Open Access Journals (Sweden)

    Gancher Joshua

    2017-04-01

    Full Text Available We present the idea of externally verifiable oblivious RAM (ORAM. Our goal is to allow a client and server carrying out an ORAM protocol to have disputes adjudicated by a third party, allowing for the enforcement of penalties against an unreliable or malicious server. We give a security definition that guarantees protection not only against a malicious server but also against a client making false accusations. We then give modifications of the Path ORAM [15] and Ring ORAM [9] protocols that meet this security definition. These protocols both have the same asymptotic runtimes as the semi-honest original versions and require the external verifier to be involved only when the client or server deviates from the protocol. Finally, we implement externally verified ORAM, along with an automated cryptocurrency contract to use as the external verifier.

  14. Probability analysis of dynamical effects of axial piston hydraulic motor

    OpenAIRE

    Sapietova Alzbeta; Dekys Vladimír; Sapieta Milan; Sulka Peter; Gajdos Lukas; Rojek Izabela

    2018-01-01

    The paper presents an analysis of impact force on stopper screw in axial piston hydraulic motor. The solution contains probabilistic description of input variables. If the output parameters of probabilistic solution are compared with arbitrary values and values acquired by analytical solution, the probability of proper operation of the device can be evaluated.

  15. The effect of polyploidization on tree hydraulic functioning.

    Science.gov (United States)

    De Baerdemaeker, Niels J F; Hias, Niek; Van den Bulcke, Jan; Keulemans, Wannes; Steppe, Kathy

    2018-02-01

    Recent research has highlighted the importance of living tissue in wood. Polyploidization can impact amounts and arrangements of living cells in wood, potentially leading to increased drought tolerance. Tetraploid variants were created from the apple cultivar Malus ×domestica 'Gala' (Gala-4x), and their vulnerability to drought-induced cavitation and their hydraulic capacitance were compared to those of their diploid predecessors (Gala-2x). Assuming a positive correlation between polyploidy and drought tolerance, we hypothesized lower vulnerability and higher capacitance for the tetraploid. Vulnerability to drought-induced cavitation and the hydraulic capacitance were quantified through acoustic emission and continuous weighing of shoots during a bench-top dehydration experiment. To underpin the hydraulic trait results, anatomical variables such as vessel area, conduit diameter, cell wall reinforcement, and ray and vessel-associated parenchyma were measured. Vulnerability to drought-induced cavitation was intrinsically equal for both ploidy variants, but Gala-4x proved to be more vulnerable than Gala-2x during the early phase of desiccation as was indicated by its significantly lower air entry value. Higher change in water content of the leafy shoot, higher amount of parenchyma, and larger vessel area and size resulted in a significantly higher hydraulic capacitance and efficiency for Gala-4x compared to Gala-2x. Both ploidy variants were typified as highly sensitive to drought-induced cavitation, with no significant difference in their overall drought vulnerability. But, when water deficit is short and moderate, Gala-4x may delay a drought-induced decrease in performance by trading hydraulic safety for increased release of capacitively stored water from living tissue. © 2018 Botanical Society of America.

  16. Effects of hydraulic shellfish harvesting on benthic communities and sediment chemistry 2009-2013

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The effects of hydraulic shellfish harvesting on the ecology of biological communities and chemistry of benthic sediments were investigated through a series of...

  17. Temperature effects on geotechnical and hydraulic properties of bentonite hydrated with inorganic salt solutions

    DEFF Research Database (Denmark)

    Rashid, H. M. A.; Kawamoto, K.; Saito, T.

    2015-01-01

    © 2015, International Journal of GEOMATE. This study investigated the combined effect of temperature and single-species salt solutions on geotechnical properties (swell index and liquid limit) and hydraulic conductivity of bentonite applying different cation types, concentrations, and temperatures...

  18. Investigation on the effect of seawater to hydraulic property and wetting process of bentonite

    International Nuclear Information System (INIS)

    Hasegawa, Takuma

    2004-01-01

    On high-level waste disposal, bentonite is one of the most promising material for buffer and backfill material. The hydraulic properties and wetting process of bentonite are important not only for barrier performance assessment but also for prediction of waste disposal environment, such as resaturation time and thermal distribution. In Japan, we should consider the effect of seawater for bentonite, because radioactive waste will be disposed of in coastal area and in marine sediment where seawater remained. However, it is not enough to understand the effect of seawater. Therefore, experimental study was conducted to investigate the effect of seawater on the hydraulic conductivity and wetting process of bentonite. The effect of seawater on hydraulic conductivity is significant for Na-bentonite, the hydraulic conductivity of Na-bentonite in seawater is one order to magnitude higher than that in distilled water. On the other hand, the hydraulic conductivity of Ca-bentonite is not influenced by seawater. The hydraulic conductivity of bentonite decreases as effective montmorillonite density increases. The effective montmorillonite density is ratio between the weight of montmorillonite and volume of porosity and montmorillonite. The hydraulic conductivity of bentonite is close related to swelling property since the hydraulic conductivity decrease as the swelling pressure increase. Wetting process of compacted bentonite could be evaluated by diffusion phenomena since infiltration rate and change of saturation rate and represented by diffusion equation. The effect of seawater on water diffusivity is significant for Na-type bentonite with low effective montmorillonite density. Except for that condition, the water diffusivity of bentonite is almost constant and is not influenced by effective montmorillonite density and seawater. (author)

  19. Positive effects of melatonin treatment on the reproductive performance of young border leicester rams mated to merino ewes in spring: preliminary observations.

    Science.gov (United States)

    Kleemann, D O; Kelly, J M; Arney, L J; Farley, I L; Tilbrook, A J; Walker, S K

    2014-12-01

    Poor reproductive performance of Merino ewe flocks when mated to Border Leicester rams during spring may be due to seasonality of the Border Leicester breed. Two approaches were taken to test this assumption. Six young (12 months old) or six mixed-age (12, 24 and ≥36 months old) Border Leicester rams were either treated or not treated with melatonin implants (2 × 2 design) 6 weeks before the four groups of rams were each put with approximately 300 Merino ewes for an 8-week mating period. Implants were inserted in early September (experiment 1). The second approach was to yard or not yard ewes and mixed-age rams on several occasions during the first 3 weeks of the mating period (experiment 2). Pregnancy rate and twinning percentage were assessed by ultrasonography. In experiment 1, melatonin treatment in young rams increased (p pregnancy rate from 5.0% to 92.6%, but mixed-age rams did not respond (90.7% vs 89.5% for melatonin and non-melatonin treatments, respectively). Twinning rate was similar (p > 0.05) for ewes mated to either melatonin or non-melatonin-treated young rams (36.8% vs 40.0%, respectively), whereas melatonin significantly improved (p melatonin treatment, scrotal circumference was greater (p pregnancy rate compared with non-yarded counterparts (89.5% vs 65.5%). Twinning rate was not affected (37.7% vs 36.1%, respectively). In summary, melatonin treatment of Border Leicester rams significantly improved flock reproductive performance in spring due to improved pregnancy rates with young rams and improved litter size with mixed-age rams. © 2014 Commonwealth of Australia.

  20. Radioactive material (RAM) accident/incident data analysis program

    International Nuclear Information System (INIS)

    Emerson, E.L.; McClure, J.D.

    1985-03-01

    This report describes the development of the Radioactive Material Transportation Accident/Incident Data Base (RAM-AIDB), which contains information on the occurrences of transportation accidents and incidents, for radioactive materials (RAM) that are involved in the process of transportation, loading and unloading operation, or temporary storage. These transportation operations are in support of the nuclear fuel cycle for electrical energy generation. This study analyzes in some detail basic accident/incident statistical data, RAM packaging accident response data, and the health effects associated with RAM transport accidents/incidents. This report presents a summary of US RAM transport accident/incident experience for the period 1971 through December 1981. In addition, a sample annual summary of accident/incident experience is presented for the calendar year 1981

  1. The effect of hydraulic bed movement on the quality of chest compressions.

    Science.gov (United States)

    Park, Maeng Real; Lee, Dae Sup; In Kim, Yong; Ryu, Ji Ho; Cho, Young Mo; Kim, Hyung Bin; Yeom, Seok Ran; Min, Mun Ki

    2017-08-01

    The hydraulic height control systems of hospital beds provide convenience and shock absorption. However, movements in a hydraulic bed may reduce the effectiveness of chest compressions. This study investigated the effects of hydraulic bed movement on chest compressions. Twenty-eight participants were recruited for this study. All participants performed chest compressions for 2min on a manikin and three surfaces: the floor (Day 1), a firm plywood bed (Day 2), and a hydraulic bed (Day 3). We considered 28 participants of Day 1 as control and each 28 participants of Day 2 and Day 3 as study subjects. The compression rates, depths, and good compression ratios (>5-cm compressions/all compressions) were compared between the three surfaces. When we compared the three surfaces, we did not detect a significant difference in the speed of chest compressions (p=0.582). However, significantly lower values were observed on the hydraulic bed in terms of compression depth (p=0.001) and the good compression ratio (p=0.003) compared to floor compressions. When we compared the plywood and hydraulic beds, we did not detect significant differences in compression depth (p=0.351) and the good compression ratio (p=0.391). These results indicate that the movements in our hydraulic bed were associated with a non-statistically significant trend towards lower-quality chest compressions. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. Effect of Priangan ram seminal plasma on viability of Peranakan Etawah buck spermatozoa preserved at 3–5oC

    Directory of Open Access Journals (Sweden)

    Muhammad Rizal

    2008-03-01

    Full Text Available In processing of buck semen, seminal plasma is a problem because it contains a phospholipase A enzime produced by the Cowper gland. If this enzime interacts with egg yolk, it causes semen coagulation, and consequently death of spermatozoa. The purpose of this research was to examine the effect of Priangan ram seminal plasma on viability of Peranakan Etawah (PE buck spermatozoa preserved at 3–5oC. Semen was collected using artificial vagina once a week. Fresh semen was divided into three tubes then centrifuged at 3,000 RPM for 30 min. Supernatant of the first tube was mixed again with Pasteur pipette (treatment A or control. Supernatant of the second tube was removed (treatment B or without seminal plasma. Supernatant of the third tube was removed and changed with Priangan ram seminal plasma in the same volume (treatment C. Semen was diluted with Tris extender containing 20% egg yolk and stored in refrigerator at 3–5oC. Quality of diluted-semen including percentages of motile spermatozoa (MS, live spermatozoa (LS, and intact plasma membrane (IPM was evaluated every day during storage at 3–5oC for three days. Results of this study showed that mean volume, colour, consistency, pH, mass activity, spermatozoa concentration, MS, LS, spermatozoa abnormal, and IPM of PE buck fresh semen, respectively was 0.68 ml, cream, thick, 7, ++/+++, 4,148.57 million cell/ml, 70%, 83.89%, 7.12% and 84%. At day-4 of storage, percentages of MS, LS, and IPM for treatment C (40, 52.2 and 51.6% was significantly (P<0.05 higher than that of: treatment B (31, 44.8 and 45.2% and treatment A (11, 15.6 and 14.8%. In conclusion, seminal plasma of Priangan ram could maintain the quality of PE buck semen preserved at 3–5oC for three days, and it prevent semen from coagulation.

  3. PLC based control system for RAM assembly test facility

    International Nuclear Information System (INIS)

    Kulkarni, S.S.; Kumar, Vinaya; Chandra, Umesh

    1994-01-01

    The flexibility, expandability, ease of programming and diagnostic features makes the programmable logic controller (PLC) suitable for a variety of control applications in engineering system test facilities. A PLC based control system for RAM assembly test facility (RATF) and for testing the related hydraulic components is being developed and installed at BARC. This paper describes the approach taken for meeting the control requirements and illustrates the PLC software that has been developed. (author). 1 fig

  4. The Effect of Flywheel Unbalance on Gear Noise in the Hydraulic Power Plant Turbo-Generator

    Directory of Open Access Journals (Sweden)

    Tomeh Elias

    2017-01-01

    Full Text Available The Effect of Flywheel Unbalance on Gear Noise in the Hydraulic Power Plant Turbo-Generator. Hydraulic power plants are systems that produce electrical energy with high investment costs. In order to fulfil their goals, investments should create conditions for a safe production of energy in a long lasting and reliable way, and with the required power and quality. These goals are possible to reach by an optional control process linked to a systematic monitoring of the operating machinery state, using the method of vibration diagnostics. Lately, there has been an increase of noise level in the hydraulic power plants.

  5. The Effects of Ram-pressure Stripping and Supernova Winds on the Tidal Stirring of Disky Dwarfs: Enhanced Transformation into Dwarf Spheroidals

    International Nuclear Information System (INIS)

    Kazantzidis, Stelios; Mayer, Lucio; Callegari, Simone; Dotti, Massimo; Moustakas, Leonidas A.

    2017-01-01

    A conclusive model for the formation of dwarf spheroidal (dSph) galaxies still remains elusive. Owing to their proximity to the massive spirals Milky Way (MW) and M31, various environmental processes have been invoked to explain their origin. In this context, the tidal stirring model postulates that interactions with MW-sized hosts can transform rotationally supported dwarfs, resembling present-day dwarf irregular (dIrr) galaxies, into systems with the kinematic and structural properties of dSphs. Using N -body+SPH simulations, we investigate the dependence of this transformation mechanism on the gas fraction, f _g_a_s, in the disk of the progenitor dwarf. Our numerical experiments incorporate for the first time the combined effects of radiative cooling, ram-pressure stripping, star formation, supernova (SN) winds, and a cosmic UV background. For a given orbit inside the primary galaxy, rotationally supported dwarfs with gas fractions akin to those of observed dIrrs ( f _g_a_s ≳ 0.5), demonstrate a substantially enhanced likelihood and efficiency of transformation into dSphs relative to their collisionless ( f _g_a_s = 0) counterparts. We argue that the combination of ram-pressure stripping and SN winds causes the gas-rich dwarfs to respond more impulsively to tides, augmenting their transformation. When f _g_a_s ≳ 0.5, disky dwarfs on previously unfavorable low-eccentricity or large-pericenter orbits are still able to transform. On the widest orbits, the transformation is incomplete; the dwarfs retain significant rotational support, a relatively flat shape, and some gas, naturally resembling transition-type systems. We conclude that tidal stirring constitutes a prevalent evolutionary mechanism for shaping the structure of dwarf galaxies within the currently favored CDM cosmological paradigm.

  6. The Effects of Ram-pressure Stripping and Supernova Winds on the Tidal Stirring of Disky Dwarfs: Enhanced Transformation into Dwarf Spheroidals

    Science.gov (United States)

    Kazantzidis, Stelios; Mayer, Lucio; Callegari, Simone; Dotti, Massimo; Moustakas, Leonidas A.

    2017-02-01

    A conclusive model for the formation of dwarf spheroidal (dSph) galaxies still remains elusive. Owing to their proximity to the massive spirals Milky Way (MW) and M31, various environmental processes have been invoked to explain their origin. In this context, the tidal stirring model postulates that interactions with MW-sized hosts can transform rotationally supported dwarfs, resembling present-day dwarf irregular (dIrr) galaxies, into systems with the kinematic and structural properties of dSphs. Using N-body+SPH simulations, we investigate the dependence of this transformation mechanism on the gas fraction, f gas, in the disk of the progenitor dwarf. Our numerical experiments incorporate for the first time the combined effects of radiative cooling, ram-pressure stripping, star formation, supernova (SN) winds, and a cosmic UV background. For a given orbit inside the primary galaxy, rotationally supported dwarfs with gas fractions akin to those of observed dIrrs (f gas ≳ 0.5), demonstrate a substantially enhanced likelihood and efficiency of transformation into dSphs relative to their collisionless (f gas = 0) counterparts. We argue that the combination of ram-pressure stripping and SN winds causes the gas-rich dwarfs to respond more impulsively to tides, augmenting their transformation. When f gas ≳ 0.5, disky dwarfs on previously unfavorable low-eccentricity or large-pericenter orbits are still able to transform. On the widest orbits, the transformation is incomplete; the dwarfs retain significant rotational support, a relatively flat shape, and some gas, naturally resembling transition-type systems. We conclude that tidal stirring constitutes a prevalent evolutionary mechanism for shaping the structure of dwarf galaxies within the currently favored CDM cosmological paradigm.

  7. The Effects of Ram-pressure Stripping and Supernova Winds on the Tidal Stirring of Disky Dwarfs: Enhanced Transformation into Dwarf Spheroidals

    Energy Technology Data Exchange (ETDEWEB)

    Kazantzidis, Stelios [Section of Astrophysics, Astronomy and Mechanics, Department of Physics, National and Kapodistrian University of Athens, 15784 Zografos, Athens (Greece); Mayer, Lucio [Center for Theoretical Astrophysics and Cosmology, Institute for Computational Science, University of Zürich, CH-8057 Zürich (Switzerland); Callegari, Simone [Anthropology Institute and Museum, University of Zürich, CH-8057 Zürich (Switzerland); Dotti, Massimo [Università degli Studi di Milano-Bicocca, Piazza della Scienza 3, I-20126 Milano (Italy); Moustakas, Leonidas A., E-mail: skazantzidis@phys.uoa.gr [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States)

    2017-02-10

    A conclusive model for the formation of dwarf spheroidal (dSph) galaxies still remains elusive. Owing to their proximity to the massive spirals Milky Way (MW) and M31, various environmental processes have been invoked to explain their origin. In this context, the tidal stirring model postulates that interactions with MW-sized hosts can transform rotationally supported dwarfs, resembling present-day dwarf irregular (dIrr) galaxies, into systems with the kinematic and structural properties of dSphs. Using N -body+SPH simulations, we investigate the dependence of this transformation mechanism on the gas fraction, f {sub gas}, in the disk of the progenitor dwarf. Our numerical experiments incorporate for the first time the combined effects of radiative cooling, ram-pressure stripping, star formation, supernova (SN) winds, and a cosmic UV background. For a given orbit inside the primary galaxy, rotationally supported dwarfs with gas fractions akin to those of observed dIrrs ( f {sub gas} ≳ 0.5), demonstrate a substantially enhanced likelihood and efficiency of transformation into dSphs relative to their collisionless ( f {sub gas} = 0) counterparts. We argue that the combination of ram-pressure stripping and SN winds causes the gas-rich dwarfs to respond more impulsively to tides, augmenting their transformation. When f {sub gas} ≳ 0.5, disky dwarfs on previously unfavorable low-eccentricity or large-pericenter orbits are still able to transform. On the widest orbits, the transformation is incomplete; the dwarfs retain significant rotational support, a relatively flat shape, and some gas, naturally resembling transition-type systems. We conclude that tidal stirring constitutes a prevalent evolutionary mechanism for shaping the structure of dwarf galaxies within the currently favored CDM cosmological paradigm.

  8. Hydraulic activity of belite cement from class C coal fly ash. Effect of curing and admixtures

    OpenAIRE

    Goñi, S., Guerrero, A.

    2006-01-01

    [EN] The effect of curing method and a water-reducing additive on the hydraulic activity of high lime content (ASTM type C) fly ash belite cement (FABC-2-W) is reported. A class C fly ash was subjected to hydrothermal treatment and subsequent calcination to synthesize FABC. Hydraulic activity was evaluated in the cement paste over 180 days from the physically bound water content as determined by thermogravimetric analysis and the degree of hydration, in turn found with...

  9. Hydraulic testing around Room Q: Evaluation of the effects of mining on the hydraulic properties of Salado Evaporites

    International Nuclear Information System (INIS)

    Domski, P.S.; Upton, D.T.; Beauheim, R.L.

    1996-03-01

    Room Q is a 109-m-long cylindrical excavation in the Salado Formation at the Waste Isolation Pilot Plant (WIPP) site. Fifteen boreholes were drilled and instrumented around Room Q so that tests could be conducted to determine the effects of room excavation on the hydraulic properties of the surrounding evaporate rocks. Pressure-buildup and pressure-pulse tests were conducted in all of the boreholes before Room Q was mined. The data sets from only eight of the boreholes are adequate for parameter estimation, and five of those are of poor quality. Constant-pressure flow tests and pressure-buildup tests were conducted after Room Q was mined, producing eleven interpretable data sets, including two of poor quality. Pre-mining transmissivities interpreted from the three good-quality data sets ranged from 1 x 10 -15 to 5 x 10 -14 m 2 /s (permeability-thickness products of 2 x 10 -22 to 9 x 10 -21 m 3 ) for test intervals ranging in length from 0.85 to 1.37 m. Pre-mining average permeabilities, which can be considered representative of undisturbed, far-field conditions, were 6 x 10 -20 and 8 x 10 -20 m 2 for anhydrite, and 3 x 10 -22 m 2 for halite. Post-mining transmissivities interpreted from the good-quality data sets ranged from 1 x 10 -16 to 3 x 10 -13 m 2 /s (permeability-thickness products of 2 x 10 -23 to 5 x 10 -20 m 3 ). Post-mining average permeabilities for anhydrite ranged from 8 x 10 -20 to 1 x 10 -19 m 2 . The changes in hydraulic properties and pore pressures that were observed can be attributed to one or a combination of three processes: stress reduction, changes in pore connectivity, and flow towards Room Q. The effects of the three processes cannot be individually quantified with the available data

  10. The pattern of LH secretion and the ovarian response to the 'ram effect' in the anoestrous ewe is influenced by body condition but not by short-term nutritional supplementation.

    Science.gov (United States)

    Scaramuzzi, R J; Oujagir, L; Menassol, J-B; Freret, S; Piezel, A; Brown, H M; Cognié, J; Fabre Nys, C

    2014-10-01

    In sheep, the 'ram effect' induces out-of-season fertility and good nutrition increases prolificacy. This experiment determined if fatness or short-term nutritional supplementation modified the response to the 'ram effect'. A group of 48 Île-de-France ewes were fed diets that produced groups with body-condition scores (BCS) of >3.0 and <2.0. Within each BCS group animals were supplemented daily with 500g of lupins from Day -5 to Day 0 (ram introduction) resulting in four groups: low BCS, supplemented (n=7) and non-supplemented (n=8) and high BCS, supplemented (n=12) and non-supplemented (n=11). The blood concentrations of glucose and insulin and the LH response to gonadotrophin-releasing hormone (GnRH) were determined. After the 'ram effect' the pattern of LH pulsatility, the LH surge and ovarian responses were analysed. Low BCS ewes had lower glucose and insulin (P<0.001) and supplementation increased both (P≤0.001). The increase in LH induced by GnRH was reduced in low BCS ewes (P=0.015) but it was not affected by supplementation. Similarly, LH pulsatility was reduced in low BCS ewes (P<0.05). The LH surge and ovarian cyclicity were not affected but the follow-up cycle was delayed (P=0.034) and progesterone was reduced (P=0.029) in low BCS ewes. There was an effect of BCS on ovulation rate (P<0.05). These results show that the BCS can modify the response to the 'ram effect' and that supplementation has little effect on this response.

  11. Quantifying the Effects of Biofilm on the Hydraulic Properties of Unsaturated Soils

    Science.gov (United States)

    Volk, E.; Iden, S.; Furman, A.; Durner, W.; Rosenzweig, R.

    2017-12-01

    Quantifying the effects of biofilms on hydraulic properties of unsaturated soils is necessary for predicting water and solute flow in soil with extensive microbial presence. This can be relevant to bioremediation processes, soil aquifer treatment and effluent irrigation. Previous works showed a reduction in the hydraulic conductivity and an increase in water content due to the addition of biofilm analogue materials. The objective of this research is to quantify soil hydraulic properties of unsaturated soil (water retention and hydraulic conductivity) using real soil biofilm. In this work, Hamra soil was incubated with Luria Broth (LB) and biofilm-producing bacteria (Pseudomonas Putida F1). Hydraulic conductivity and water retention were measured by the evaporation method, Dewpoint method and a constant head permeameter. Biofilm was quantified using viable counts and the deficit of TOC. The results show that the presence of biofilms increases soil retention in the `dry' range of the curve and reduces the hydraulic conductivity (see figure). This research shows that biofilms may have a non-negligible effect on flow and transport in unsaturated soils. These findings contribute to modeling water flow in biofilm amended soil.

  12. Effect of dietary fish oil supplementation on ram semen freeze ability and fertility using soybean lecithin- and egg yolk-based extenders.

    Science.gov (United States)

    Masoudi, R; Sharafi, M; Zare Shahneh, A; Towhidi, A; Kohram, H; Zhandi, M; Esmaeili, V; Shahverdi, A

    2016-10-01

    Ram semen cryopreservation is not efficient for artificial insemination in commercial herds. Beneficial effects of dietary fish oil have been evaluated for cryopreservation of ram semen in soybean lecithin (SL) and egg yolk (EY)-based extenders. A factorial study (two diets × two extenders) was used to analyze the effects of two diets supplemented with fish oil (n-3 fatty acid) or palm oil (saturated fatty acids; [SFAs]) to freeze ram semen in two extenders containing SL or EY. Motility characteristics, membrane integrity, abnormal morphology, mitochondria activity, acrosome integrity, apoptotic status, and fertilizing ability were assessed after freeze-thawing. Although diet had significant (P ≤ 0.05) effects on the quality parameters of frozen-thawed sperm, effects of extenders on these traits were not significant (P > 0.05). The higher significant (P ≤ 0.05) percentage of total motility and progressive motility were observed in n-3/SL (44.83 ± 1.56 and 28.33 ± 1.4) and n-3/EY (43.33 ± 1.56 and 28.50 ± 1.4) than SFA/SL (32.16 ± 1.56 and 14.00 ± 1.4) and SFA/EY (31.66 ± 1.56 and 12.66 ± 1.4) groups. Moreover, n-3/SL and n-3/EY produced the higher significant (P ≤ 0.05) percentage of membrane integrity of sperm (39.83 ± 1.4 and 37.33 ± 1.4) than SFA/SL and SFA/EY (29.83 ± 1.4 and 28.5 ± 1.4). For viability results, the higher significant percentage of live sperm was observed in n-3/SL and n-3/EY (43.16 ± 1.38 and 45.66 ± 1.38) than SFA/SL and SFA/EY (28.66 ± 1.38 and 27.5 ± 1.38). For fertility trials, n-3-based diets (n-3/SL and n-3/EY) improved significantly (P ≤ 0.05) pregnancy rate (44% and 46%), parturition rate (42% and 42%), and lambing rate (46% and 44%) compared with the SFA-based diets (SFA/SL and SFA/EY). No interaction effects have been found between diets and extenders (P > 0.05). It seems that dietary fish oil can improve the semen performance after freezing-thawing process and

  13. Sustainable Hydraulic Barrier Design Technologies for Effective Infrastructure Engineering

    Directory of Open Access Journals (Sweden)

    Chitral Wijeyesekera Devapriya

    2017-01-01

    Full Text Available Migration of liquids lead to embarrassing post construction scenarios such as that of leaks from roofs, potable water leaking from water tanks/ reservoirs, rising damp in walls with groundwater seeping into basement structures, leakage of water from ornamental lakes and ponds or leachate leakage into the environment from MSW landfill sites. Such failures demand immediate and expensive maintenance. A stringent control on structural and waterproof stability is deemed necessary for long term service life of structures and in particular underground and near surface structures. On a micro scale and over a longer time scale, the phenomenon of rising dampness occurs in older buildings with the groundwater rising up through walls, floors and masonry via capillary action. Even slower rates of contaminant fluid migration occur through landfill base liners. In this paper a variety of hydraulic barrier technologies is critically discussed against a backdrop of relevant case studies. The choice of an appropriate hydraulic barrier technology for a given scenario will depend also on the sustainability, financial affordability and subjective aesthetics.

  14. EFFECTIVE APPLICATIO N OF LIDAR DATA IN T WO - DIMENSIONAL HYDRAULIC MODELLING

    Directory of Open Access Journals (Sweden)

    Bakuła Krzysztof

    2014-12-01

    Full Text Available This paper presents aspects of ALS data usage in two - dimensional hydraulic modelling including generation of high - precision digital terrain models, t heir effective processing which is a compromise between the resolution and the accuracy of the processed data, as well as information about the roughness of the land cover providing information that could compete with information from topographic databases and orthophotomaps. Still evolving ALS technology makes it possible to collect the data with constantly increasing spatial resolution that guarantees correct representation of the terrain shape and height. It also provides a reliable description of the la nd cover. However, the size of generated files may cause roblems in their effective usage in the 2D hydraulic modeling where Saint - Venant’s equations are implemented. High - resolution elevation models make it impossible or prolong the duration of the calcu lations for large areas in complex algorithms defining a model of the water movement, which is directly related to the cost of the hydraulic analysis. As far as an effective usage of voluminous datasets is concerned, the data reduction is recommended. Suc h a process should reduce the size of the data files, maintain their accuracy and keep the appropriate structure to allow their further application in the hydraulic modelling. An application of only a few percent of unprocessed datasets, selected with the use of specified filtering algorithms and spatial analysis tools, can give the same result of the hydraulic modeling obtained in a significantly shorter time than the result of the comparable operation on unprocessed datasets. Such an approach, however, is not commonly used, which means the most reliable hydraulic models are applied only in small areas in the largest cities. Another application of ALS data is its potential usage in digital roughness model creation for 2D hydraulic models. There are many po ssibilities of roughness

  15. Assessment the effect of homogenized soil on soil hydraulic properties and soil water transport

    Science.gov (United States)

    Mohawesh, O.; Janssen, M.; Maaitah, O.; Lennartz, B.

    2017-09-01

    Soil hydraulic properties play a crucial role in simulating water flow and contaminant transport. Soil hydraulic properties are commonly measured using homogenized soil samples. However, soil structure has a significant effect on the soil ability to retain and to conduct water, particularly in aggregated soils. In order to determine the effect of soil homogenization on soil hydraulic properties and soil water transport, undisturbed soil samples were carefully collected. Five different soil structures were identified: Angular-blocky, Crumble, Angular-blocky (different soil texture), Granular, and subangular-blocky. The soil hydraulic properties were determined for undisturbed and homogenized soil samples for each soil structure. The soil hydraulic properties were used to model soil water transport using HYDRUS-1D.The homogenized soil samples showed a significant increase in wide pores (wCP) and a decrease in narrow pores (nCP). The wCP increased by 95.6, 141.2, 391.6, 3.9, 261.3%, and nCP decreased by 69.5, 10.5, 33.8, 72.7, and 39.3% for homogenized soil samples compared to undisturbed soil samples. The soil water retention curves exhibited a significant decrease in water holding capacity for homogenized soil samples compared with the undisturbed soil samples. The homogenized soil samples showed also a decrease in soil hydraulic conductivity. The simulated results showed that water movement and distribution were affected by soil homogenizing. Moreover, soil homogenizing affected soil hydraulic properties and soil water transport. However, field studies are being needed to find the effect of these differences on water, chemical, and pollutant transport under several scenarios.

  16. Hydraulic testing around Room Q: Evaluation of the effects of mining on the hydraulic properties of Salado Evaporites

    Energy Technology Data Exchange (ETDEWEB)

    Domski, P.S.; Upton, D.T. [INTERA, Inc., Albuquerque, NM (United States); Beauheim, R.L. [Sandia National Laboratories, Albuquerque, NM (United States)

    1996-03-01

    Room Q is a 109-m-long cylindrical excavation in the Salado Formation at the Waste Isolation Pilot Plant (WIPP) site. Fifteen boreholes were drilled and instrumented around Room Q so that tests could be conducted to determine the effects of room excavation on the hydraulic properties of the surrounding evaporate rocks. Pressure-buildup and pressure-pulse tests were conducted in all of the boreholes before Room Q was mined. The data sets from only eight of the boreholes are adequate for parameter estimation, and five of those are of poor quality. Constant-pressure flow tests and pressure-buildup tests were conducted after Room Q was mined, producing eleven interpretable data sets, including two of poor quality. Pre-mining transmissivities interpreted from the three good-quality data sets ranged from 1 x 10{sup -15} to 5 x 10{sup -14} m{sup 2}/s (permeability-thickness products of 2 x 10{sup -22} to 9 x 10{sup -21} m{sup 3}) for test intervals ranging in length from 0.85 to 1.37 m. Pre-mining average permeabilities, which can be considered representative of undisturbed, far-field conditions, were 6 x 10{sup -20} and 8 x 10{sup -20} m{sup 2} for anhydrite, and 3 x 10{sup -22} m{sup 2} for halite. Post-mining transmissivities interpreted from the good-quality data sets ranged from 1 x 10{sup -16} to 3 x 10{sup -13} m{sup 2}/s (permeability-thickness products of 2 x 10{sup -23} to 5 x 10{sup -20} m{sup 3}). Post-mining average permeabilities for anhydrite ranged from 8 x 10{sup -20} to 1 x 10{sup -19} m{sup 2}. The changes in hydraulic properties and pore pressures that were observed can be attributed to one or a combination of three processes: stress reduction, changes in pore connectivity, and flow towards Room Q. The effects of the three processes cannot be individually quantified with the available data.

  17. Laser-propelled ram accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Sasoh, A. [Tohoku Univ., Sendai (Japan). Inst. of Fluid Science

    2000-11-01

    The concept of 'laser-propelled ram accelerator (L-RAMAC)' is proposed. Theoretically it is capable of achieving a higher launch speed than that by a chemical ram accelerator because a higher specific energy can be input to the propellant gas. The laser beam is supplied through the muzzle, focused as an annulus behind the base of the projectile. The performance of L-RAMAC is analized based on generalized Rankine-Hugoniot relations, suggesting that a superorbital muzzle speed is achievable out of this device. (orig.)

  18. A RAM: Realidade e Utopia

    OpenAIRE

    Pereira, Carlos Santos

    2003-01-01

    Evoluções tecnológicas recentes, nomeadamente em matéria de electrónica e de informática, e a busca de conceitos operacionais adaptados às novas tecnologias estão a revolucionar a arte da guerra. O êxito da “Tempestade no Deserto”, em 1991 e das sucessivas intervenções militares dos EUA nos anos seguintes mais reforçaram a ideia de que se estava perante uma verdadeira revolução – É a Revolução nos Assuntos Militares (RAM). Na realidade, a RAM é um fenómeno comple...

  19. Study of effect of in-line hydropneumatic accumulators on output characteristics of hydraulic hammer

    Science.gov (United States)

    Redelin, R. A.; Kravchenko, V. A.; Kamanin, Y. N.; Panichkin, A. V.; Bozhanov, A. A.

    2017-10-01

    The article presents the results of studies of the effect of in-line hydropneumatic accumulators on the output parameters of a hydraulic hammer during their joint operation. Based on mathematical modeling, computational experiments were performed and the output characteristics of the hammer, depending on the design and operating parameters of the in-line hydropneumatic accumulators, were obtained. It was established that for the most effective operation of the hammer, the precharge pressure of the pressure line hydropneumatic accumulator should be 70-80% of the working pressure of the hydraulic system. The utilization of a hydropneumatic accumulator without special additional devices in the discharge line is impractical.

  20. The effect of inlet conditions on the air side hydraulic resistance and flow maldistribution in industrial air heaters

    Energy Technology Data Exchange (ETDEWEB)

    Hoffmann-Vocke, Jonas, E-mail: jh63@waikato.ac.nz [University of Waikato, Energy Research Group, School of Science and Engineering, Private Bag 3105, Hamilton 3240 (New Zealand); Neale, James, E-mail: jamesn@waikato.ac.nz [University of Waikato, Energy Research Group, School of Science and Engineering, Private Bag 3105, Hamilton 3240 (New Zealand); Walmsley, Michael, E-mail: walmsley@waikato.ac.nz [University of Waikato, Department of Engineering, School of Science and Engineering, Private Bag 3105, Hamilton 3240 (New Zealand)

    2011-08-15

    Highlights: > Measured the effects of air heater inlet header geometry on hydraulic performance. > Measured the effects of inlet header flow maldistribution on hydraulic performance. > Inlet header flow maldistribution increases air heater system hydraulic resistance. - Abstract: Experimental system hydraulic resistance measurements on a scale air heater unit have highlighted the excessive hydraulic resistance of typical industry configurations. Both poor header inlet conditions and large header expansion angles are shown to contribute to system hydraulic resistance magnitudes 20-100% higher than suitable benchmark cases. Typical centrifugal fan system efficiencies well under 80% multiply the system resistance effects resulting in larger fan power penalties. Velocity profile measurements taken upstream and downstream of the test heat exchanger under flow maldistribution conditions provide insight into the flow maldistribution spreading caused by the heat exchanger resistance. The anisotropic resistance of the plate fin-and-tube heat exchanger is shown to result in resistance induced flow dispersion being concentrated in the axis parallel to the plate fins.

  1. Mohan Ram, Prof. Holenarasipur Yoganarasimham

    Indian Academy of Sciences (India)

    Mohan Ram, Prof. Holenarasipur Yoganarasimham Ph.D. (Delhi), FNA, FNASc, FNAAS Council Service: 1983-88; Vice-President: 1986-88. Date of birth: 24 September 1930. Specialization: Plant Growth & Development and Economic Botany Address: No. 174, SFS DDA Flats, Mukherjee Nagar, Delhi 110 009, U.T.

  2. Time-bin quantum RAM

    Science.gov (United States)

    Moiseev, E. S.; Moiseev, S. A.

    2016-11-01

    We have proposed a compact scheme of quantum random access memory (qRAM) based on the impedance matched multi-qubit photon echo quantum memory incorporated with the control four-level atom in two coupled QED cavities. A set of matching conditions for basic physical parameters of the qRAM scheme that provides an efficient quantum control of the fast single photon storage and readout has been found. In particular, it has been discovered that the efficient qRAM operations are determined by the specific properties of the excited photonic molecule coupling the two QED cavities. Herein, the maximal efficiency of the qRAM is realized when the cooperativity parameter of the photonic molecule equals to unity that can be experimentally achievable. We have also elaborated upon the new quantum address scheme where the multi-time-bin photon state is used for the control of the four-level atom during the readout of the photonic qubits from the quantum memory. The scheme reduces the required number of logical elements to one. Experimental implementation by means of current quantum technologies in the optical and microwave domains is also discussed.

  3. Effect of Hydraulic Activity on Crystallization of Precipitated Calcium Carbonate (PCC) for Eco-Friendly Paper

    Science.gov (United States)

    Kim, Jung-Ah; Han, Gi-Chun; Lim, Mihee; You, Kwang-Suk; Ryu, Miyoung; Ahn, Ji-Whan; Fujita, Toyohisa; Kim, Hwan

    2009-01-01

    Wt% of aragonite, a CaCO3 polymorph, increased with higher hydraulic activity (°C) of limestone in precipitated calcium carbonate (PCC) from the lime-soda process (Ca(OH)2-NaOH-Na2CO3). Only calcite, the most stable polymorph, was crystallized at hydraulic activity under 10 °C, whereas aragonite also started to crystallize over 10 °C. The crystallization of PCC is more dependent on the hydraulic activity of limestone than CaO content, a factor commonly used to classify limestone ores according to quality. The results could be effectively applied to the determination of polymorphs in synthetic PCC for eco-friendly paper manufacture. PMID:20087470

  4. Effect of temperature and hydraulic retention time on hydrogen producing granules: Homoacetogenesis and morphological characteristics

    International Nuclear Information System (INIS)

    Abreu, A. A.; Danko, A. S.; Alves, M. M.

    2009-01-01

    The effect of temperature and hydraulic retention time (HRT) on the homoacetogenesisi and on the morphological characteristics of hydrogen producing granules was investigated. Hydrogen was produced using an expanded granular sludge blanket (EGSB) reactor, fed with glucose and L-arabinose, under mesophilic (37 degree centigrade), thermophilic (55 degree centigrade), and hyper thermophilic (70 degree centigrade) conditions. (Author)

  5. Comparison of sexual performance and testicular characteristics of melatonin treated Kivircik and Charollais rams during the non-breeding season

    Directory of Open Access Journals (Sweden)

    M. Cevik

    Full Text Available ABSTRACT This study was conducted to investigate the effects of melatonin implantation on basic testicular characteristics and reproductive performance of Kivircik and Charollais rams and ewes during the non-breeding season. In this study, 8 Kivircik and 6 Charollais rams were used. Rams were implanted with 54 mg melatonin according to the manufacturer's instructions. At melatonin implantation and at ram introduction the reproductive performance and testicular characteristics were evaluated. Throughout the experimental period, rams were permanently kept outdoors under conditions of natural day length and at ambient temperature. The effects of exogenous melatonin treatments on the reproductive performances of rams and ewes, estrus response, pregnancy rate, litter size and twinning rate of ewes were evaluated in all groups. Libido values were significantly higher in Charollais rams compared to Kivircik rams (P<0.001. Testicular volume (TV was increased in both ram breeds. Scrotal length (SL was also increased in both Kivircik and Charollais rams (P<0.01. In conclusion, we showed that the treatment of rams with slow release melatonin implants increased scrotal diameters and testicular volumes in both Kivircik and Charollais rams. Furthermore, melatonin implantation improved the reproductive performances of ewes naturally mated with these melatonin implanted rams during non-breeding season.

  6. Increasing the effectiveness of the hydraulic fracturing of seams with the use of the pattern recognition method

    Energy Technology Data Exchange (ETDEWEB)

    Rasizade, Ya M; Nagiev, T M; Kuznetsov, V I; Mikerin, B P

    1977-08-01

    An examination is made of using a sequential diagnostic procedure for increasing the effectiveness of the hydraulic fracturing of seams in boreholes of the gas and oil drilling administration of the Khadyzhenneft' association. The use of the pattern recognition method was shown to make it possible to increase the effectiveness of hydraulic fracturing by up to 80%. 4 references, 1 figure, 3 tables.

  7. Evaluation of Lasting Effects of Heat Stress on Sperm Profile and Oxidative Status of Ram Semen and Epididymal Sperm

    Directory of Open Access Journals (Sweden)

    Thais Rose dos Santos Hamilton

    2016-01-01

    Full Text Available Higher temperatures lead to an increase of testicular metabolism that results in spermatic damage. Oxidative stress is the main factor responsible for testicular damage caused by heat stress. The aim of this study was to evaluate lasting effects of heat stress on ejaculated sperm and immediate or long-term effects of heat stress on epididymal sperm. We observed decrease in motility and mass motility of ejaculated sperm, as well as an increase in the percentages of sperm showing major and minor defects, damaged plasma and acrosome membranes, and a decrease in the percentage of sperm with high mitochondrial membrane potential in the treated group until one spermatic cycle. An increased enzymatic activity of glutathione peroxidase and an increase of stressed cells were observed in ejaculated sperm of the treated group. A decrease in the percentage of epididymal sperm with high mitochondrial membrane potential was observed in the treated group. However, when comparing immediate and long-term effects, we observed an increase in the percentage of sperm with low mitochondrial membrane potential. In conclusion, testicular heat stress induced oxidative stress that led to rescuable alterations after one spermatic cycle in ejaculated sperm and also after 30 days in epididymal sperm.

  8. Thermal-hydraulic effects of transition to improved System 80TM fuel

    International Nuclear Information System (INIS)

    Rodack, T.; Joffre, P.F.; Kapoor, R.K.

    2004-01-01

    ABB CE's improved System 80 TM PWR fuel design includes GUARDIAN debris-resistant features and laser-welded Zircaloy grids. The GUARDIAN features include an Inconel grid with debris-filtering features located just above the Lower End Fitting, and a solid fuel rod bottom end cap that extends above the filtering features. Tests and analyses were done to establish the impact of these design improvements on fuel assembly hydraulic performance. Further analysis was done to determine the mixed core thermal-hydraulic performance as the transition is made over two fuel cycles to a full core of the improved System 80 TM fuel. Results confirm that the Thermal-Hydraulic (T-H) effects of the reduction in hydraulic resistance between the improved and resident fuel due to the laser-welded Zircaloy grids offsets the effects of the increased resistance GUARDIAN grid. Therefore, the mechanically improved System 80 TM fuel can be implemented with no net impact on Departure from Nucleate Boiling (DNB) margin in transition cores. (author)

  9. Effect of green tea (Camellia sinensis) extract and pre-freezing equilibration time on the post-thawing quality of ram semen cryopreserved in a soybean lecithin-based extender.

    Science.gov (United States)

    Mehdipour, Mahdieh; Daghigh Kia, Hossein; Najafi, Abouzar; Vaseghi Dodaran, Hossein; García-Álvarez, Olga

    2016-12-01

    The aim of this study was to determine the effect of Camellia sinensis extract as antioxidant supplement and pre-freezing equilibration times in a soybean lecithin extender for freezing ram semen. In this study, a total of 20 ejaculates were collected from four Ghezel rams and diluted with extenders (1.5% soybean lecithin, 7% glycerol) containing no supplements (control) and Camellia sinensis extract (5, 10, and 15 mg/L) and cryopreserved, immediately after thermal equilibrium was reached at 5 °C (0 h), or 4 h after equilibration. Sperm motility characteristics, membrane integrity, abnormal morphology, mitochondria activity, apoptotic status, MDA and antioxidant activities (GPx, SOD and total antioxidant capacity (TAC)) were evaluated following freeze-thawing. Camellia sinensis extract at level 10 mg/L led to the highest total and progressive motilities percentages, in comparison to other treatments (P extract at level of 5 and 10 mg/L led to higher plasma membrane integrity, mitochondria activity and Total antioxidant capacity (TAC) in comparison to the level of 15 mg/L and control group (P extract at 10 mg/L level produced the highest percentage of live spermatozoa and the lowest apoptotic spermatozoa in comparison to all treatments (P concentration, 10 mg/L, compared to all treatments (P  0.05) were observed between equilibration times (0 h vs. 4 h) for sperm samples incubated with or without different concentrations of Camellia sinensis extract. In conclusion, addition of Camellia sinensis extract at level of 10 mg/L can improve post-thawing quality of ram semen cryopreserved in a soybean lecithin extender. However, further research is needed to standardize the process of Camellia sinensis extraction and specially for identifying which compounds are responsible of its beneficial effect on ram sperm cryopreservation. Copyright © 2016 Elsevier Inc. All rights reserved.

  10. Carbofuran biodegradation in brackish groundwater and its effect on the hydraulic properties of the porous medium

    Science.gov (United States)

    Amiaz, Yanai; Ronen, Zeev; Adar, Eilon; Weisbrod, Noam

    2015-04-01

    A chalk fractured aquitard beneath an industrial site is subjected to intense contamination due to percolation of contaminants from the different facilities operating at the site. In order to reduce further contamination, draining trenches were excavated and filled with coarse gravel (3-4 cm in diameter) forming a porous medium, to which the contaminated groundwater discharges from the fractures surrounding the trenches. This research is aimed at establishing a biodegrading process of high efficiency and performance within the draining trenches. The research includes both field and laboratory experiments. An experimental setup of five columns (50 cm length and 4.5 cm in diameter) was constructed under highly controlled conditions. Over the course of the experiments, the columns were filled with different particle sizes and placed in a temperature controlled chamber. Filtered groundwater (0.2 µm) from the site groundwater, enriched by a model contaminant carbofuran (CRF), was injected to the columns; as two of the columns were inoculated by CRF degrading microorganisms native in the site's groundwater, two columns were inoculated by CRF degrading bacteria from the external environment, and one column was used as a control. During the experiment, measurements were taken from different locations along each column. These include: (a) CRF concentration and (b) hydraulic pressure and solution viscosity (in order to obtain the changes in permeability). A tracer test using uranine was carried out in parallel, in order to obtain the changes in hydraulic parameters. Correlating CRF concentration variations to changes of hydraulic parameters enable the deduction due to the effect that biological activity (under different temperature regimes) has on the hydraulic properties of the porous medium and its effect on the process of contaminant groundwater bodies' remediation. Preliminary results suggest that although biodegradation occurs, microbial activity has minor effect on

  11. A study on the effective hydraulic conductivity of an anisotropic porous medium

    International Nuclear Information System (INIS)

    Seong, Kwan Jae

    2002-01-01

    Effective hydraulic conductivity of a statistically anisotropic heterogeneous medium is obtained for steady two-dimensional flows employing stochastic analysis. Flow equations are solved up to second order and the effective conductivity is obtained in a semi-analytic form depending only on the spatial correlation function and the anisotropy ratio of the hydraulic conductivity field, hence becoming a true intrinsic property independent of the flow field. Results are obtained using a statistically anisotropic Gaussian correlation function where the anisotropic is defined as the ratio of integral scales normal and parallel to the mean flow direction. Second order results indicate that the effective conductivity of an anisotropic medium is greater than that of an isotropic one when the anisotropy ratio is less than one and vice versa. It is also found that the effective conductivity has upper and lower bounds of the arithmetic and the harmonic mean conductivities

  12. Effect of liquid surface tension on circular and linear hydraulic jumps; theory and experiments

    Science.gov (United States)

    Bhagat, Rajesh Kumar; Jha, Narsing Kumar; Linden, Paul F.; Wilson, David Ian

    2017-11-01

    The hydraulic jump has attracted considerable attention since Rayleigh published his account in 1914. Watson (1964) proposed the first satisfactory explanation of the circular hydraulic jump by balancing the momentum and hydrostatic pressure across the jump, but this solution did not explain what actually causes the jump to form. Bohr et al. (1992) showed that the hydraulic jump happens close to the point where the local Froude number equals to one, suggesting a balance between inertial and hydrostatic contributions. Bush & Aristoff (2003) subsequently incorporated the effect of surface tension and showed that this is important when the jump radius is small. In this study, we propose a new account to explain the formation and evolution of hydraulic jumps under conditions where the jump radius is strongly influenced by the liquid surface tension. The theory is compared with experiments employing liquids of different surface tension and different viscosity, in circular and linear configurations. The model predictions and the experimental results show excellent agreement. Commonwealth Scholarship Commission, St. John's college, University of Cambridge.

  13. A Laboratory Study of the Effects of Interbeds on Hydraulic Fracture Propagation in Shale Formation

    Directory of Open Access Journals (Sweden)

    Zhiheng Zhao

    2016-07-01

    Full Text Available To investigate how the characteristics of interbeds affect hydraulic fracture propagation in the continental shale formation, a series of 300 mm × 300 mm × 300 mm concrete blocks with varying interbeds, based on outcrop observation and core measurement of Chang 7-2 shale formation, were prepared to conduct the hydraulic fracturing experiments. The results reveal that the breakdown pressure increases with the rise of thickness and strength of interbeds under the same in-situ field stress and injection rate. In addition, for the model blocks with thick and high strength interbeds, the hydraulic fracture has difficulty crossing the interbeds and is prone to divert along the bedding faces, and the fracturing effectiveness is not good. However, for the model blocks with thin and low strength interbeds, more long branches are generated along the main fracture, which is beneficial to the formation of the fracture network. What is more, combining the macroscopic descriptions with microscopic observations, the blocks with thinner and lower strength interbeds tend to generate more micro-fractures, and the width of the fractures is relatively larger on the main fracture planes. Based on the experiments, it is indicated that the propagation of hydraulic fractures is strongly influenced by the characteristics of interbeds, and the results are instructive to the understanding and evaluation of the fracability in the continental shale formation.

  14. Modified electrical survey for effective leakage detection at concrete hydraulic facilities

    Science.gov (United States)

    Lee, Bomi; Oh, Seokhoon

    2018-02-01

    Three original electrode arrays for the effective leakage detection of concrete hydraulic facilities through electrical resistivity surveys are proposed: 'cross-potential', 'direct-potential' and modified tomography-like arrays. The main differences with respect to the commonly used arrays are that the current line-sources are separated from potential pole lines and floated upon the water. The potential pole lines are located directly next to the facility in order to obtain intuitive data and useful interpretations of the internal conditions of the hydraulic facility. This modified configuration of the array clearly displays the horizontal variation of the electrical field around the damaged zones of the concrete hydraulic facility, and any anomalous regions that might be found between potential poles placed across the facilities. In order to facilitate the interpretation of these modified electrical surveys, a new and creative way of presenting the measurements is also proposed and an inversion approach is provided for the modified tomography-like array. A numerical modeling and two field tests were performed to verify these new arrays and interpretation methods. The cross and direct potential array implied an ability to detect small variations of the potential field near the measurement poles. The proposed array showed the overall potential distribution across the hydraulic facility which may be used to assist in the search of trouble zones within the structure, in combination with the traditional electrical resistivity array.

  15. Effect of soil properties on Hydraulic characteristics under subsurface drip irrigation

    Science.gov (United States)

    Fan, Wangtao; Li, Gang

    2018-02-01

    Subsurface drip irrigation (SDI) is a technique that has a high potential in application because of its high efficiency in water-saving. The hydraulic characteristics of SDI sub-unit pipe network can be affected by soil physical properties as the emitters are buried in soils. The related research, however, is not fully explored. The laboratory tests were carried out in the present study to determine the effects of hydraulic factors including operating pressure, initial soil water content, and bulk density on flow rate and its sensitivity to each hydraulic factor for two types of SDI emitters (PLASSIM emitter and Heping emitter). For this purpose, three soils with contrasting textures (i.e., light sand, silt loam, and light clay) were repacked with two soil bulk density (1.25 and1.40 g cm-3) with two initial soil water content (12% and 18%) in plexiglass columns with 40 cm in diameter and 40 cm in height. Drip emitters were buried at depth of 20 cm to measure the flow rates under seven operating pressures (60, 100, 150, 200, 250, 300, and 370 kPa). We found that the operating pressure was the dominating factor of flow rate of the SDI emitter, and flow rate increased with the increase of operating pressure. The initial soil water content and bulk density also affected the flow rate, and their effects were the most notable in the light sand soil. The sensitivity of flow rate to each hydraulic factor was dependent on soil texture, and followed a descending order of light sand>silt loam>light clay for both types of emitters. Further, the sensitivity of flow rate to each hydraulic factor decreased with the increase of operating pressure, initial soil water content, and bulk density. This study may be used to guide the soil specific-design of SDI emitters for optimal water use and management.

  16. Experimental study of hydraulic ram effects on a liquid storage tank: Analysis of overpressure and cavitation induced by a high-speed projectile.

    Science.gov (United States)

    Lecysyn, Nicolas; Bony-Dandrieux, Aurélia; Aprin, Laurent; Heymes, Frédéric; Slangen, Pierre; Dusserre, Gilles; Munier, Laurent; Le Gallic, Christian

    2010-06-15

    This work is part of a project for evaluating catastrophic tank failures caused by impacts with a high-speed solid body. Previous studies on shock overpressure and drag events have provided analytical predictions, but they are not sufficient to explain ejection of liquid from the tank. This study focuses on the hydrodynamic behavior of the liquid after collision to explain subsequent ejection of liquid. The study is characterized by use of high-velocity projectiles and analysis of projectile dynamics in terms of energy loss to tank contents. New tests were performed at two projectile velocities (963 and 1255 m s(-1)) and over a range of viscosities (from 1 to 23.66 mPa s) of the target liquid. Based on data obtained from a high-speed video recorder, a phenomenological description is proposed for the evolution of intense pressure waves and cavitation in the target liquids. Copyright 2010 Elsevier B.V. All rights reserved.

  17. [Effects of biochar and PAM application on saline soil hydraulic properties of coastal reclamation region].

    Science.gov (United States)

    Cao, Yu Tong; She, Dong Li

    2017-11-01

    Disc infiltration tests were carried out to study the soil infiltration characteristics under different rates of soil amendments application, and to investigate the effects of biochar and polyacrylamide (PAM) application on saline soil hydraulic properties, pore characteristics and contribution of each pore to soil water flow in coastal reclamation region. The results showed that soil satura-ted hydraulic conductivity increased by 46.4% when biochar was applied at 2% compared with the control, and decreased with increasing PAM application. The total effective soil porosity and r>100 μm pores were increased by 8.3% and 10.2% (PPAM application. Particularly, the total effective soil porosity decreased markedly when PAM was applied at 1‰ and the reduction was up to 88%. With the application of biochar and PAM, the contribution of r500 μm played a major role in determining water flows.

  18. Effects of temperature and thermally-induced microstructure change on hydraulic conductivity of Boom Clay

    Directory of Open Access Journals (Sweden)

    W.Z. Chen

    2017-06-01

    Full Text Available Boom Clay is one of the potential host rocks for deep geological disposal of high-level radioactive nuclear waste in Belgium. In order to investigate the mechanism of hydraulic conductivity variation under complex thermo-mechanical coupling conditions and to better understand the thermo-hydro-mechanical (THM coupling behaviour of Boom Clay, a series of permeability tests using temperature-controlled triaxial cell has been carried out on the Boom Clay samples taken from Belgian underground research laboratory (URL HADES. Due to its sedimentary nature, Boom Clay presents across-anisotropy with respect to its sub-horizontal bedding plane. Direct measurements of the vertical (Kv and horizontal (Kh hydraulic conductivities show that the hydraulic conductivity at 80 °C is about 2.4 times larger than that at room temperature (23 °C, and the hydraulic conductivity variation with temperature is basically reversible during heating–cooling cycle. The anisotropic property of Boom Clay is studied by scanning electron microscope (SEM tests, which highlight the transversely isotropic characteristics of intact Boom Clay. It is shown that the sub-horizontal bedding feature accounts for the horizontal permeability higher than the vertical one. The measured increment in hydraulic conductivity with temperature is lower than the calculated one when merely considering the changes in water kinematic viscosity and density with temperature. The nuclear magnetic resonance (NMR tests have also been carried out to investigate the impact of microstructure variation on the THM properties of clay. The results show that heating under unconstrained boundary condition will produce larger size of pores and weaken the microstructure. The discrepancy between the hydraulic conductivity experimentally measured and predicted (considering water viscosity and density changes with temperature can be attributed to the microstructural weakening effect on the thermal volume change

  19. Static and dynamic bending has minor effects on xylem hydraulics of conifer branches (Picea abies, Pinus sylvestris).

    Science.gov (United States)

    Mayr, Stefan; Bertel, Clara; Dämon, Birgit; Beikircher, Barbara

    2014-09-01

    The xylem hydraulic efficiency and safety is usually measured on mechanically unstressed samples, although trees may be exposed to combined hydraulic and mechanical stress in the field. We analysed changes in hydraulic conductivity and vulnerability to drought-induced embolism during static bending of Picea abies and Pinus sylvestris branches as well as the effect of dynamic bending on the vulnerability. We hypothesized this mechanical stress to substantially impair xylem hydraulics. Intense static bending caused an only small decrease in hydraulic conductance (-19.5 ± 2.4% in P. abies) but no shift in vulnerability thresholds. Dynamic bending caused a 0.4 and 0.8 MPa decrease of the water potential at 50 and 88% loss of conductivity in P. sylvestris, but did not affect vulnerability thresholds in P. abies. With respect to applied extreme bending radii, effects on plant hydraulics were surprisingly small and are thus probably of minor eco-physiological importance. More importantly, results indicate that available xylem hydraulic analyses (of conifers) sufficiently reflect plant hydraulics under field conditions. © 2014 The Authors. Plant, Cell & Environment published by John Wiley & Sons Ltd.

  20. Effects on saturated hydraulic conductivity and rhizome yield

    African Journals Online (AJOL)

    SERVER

    2007-09-05

    Sep 5, 2007 ... ... as recorded at. Umudike, followed the bi-modal pattern, typical of the tropical rain- ... coefficients of determination and regression equations, were used ... Effects of mulch types, rates and sampling depth on selected physical properties of an arenic hapludult. .... as the independent variable to explain the.

  1. The effect of liner hydraulic conductivity on disposal cell performance

    International Nuclear Information System (INIS)

    Yu, C.; Yuan, Y.C.; Chia, Y.P.

    1988-01-01

    Multilayered disposal cells are frequently used for the disposal of radioactive and hazardous wastes. These disposal cells consist of materials with different permeabilities that are placed in various thicknesses at the bottom as well as in the cover of the cell. Typically, a layer of permeable material is placed above a layer with low permeability; the permeable layer functions as a drainage/leachate collection system and the low-permeability layer functions as a migration barrier/liner. This paper analyzes the effects of infiltration through unsaturated soil liners on the long-term performance of the disposal cell. Based on the results of this study, it is concluded that the long-term performance of a disposal cell is dependent on a well-designed cell cover. The design should emphasize a cap with less permeable material to prevent water from infiltrating the disposal cell. An impermeable bottom liner is effective only in the short term; however, it can eventually result in saturation of the wastes and cause the bathtub effect over the long term

  2. Evaluation of scale effects on hydraulic characteristics of fractured rock using fracture network model

    International Nuclear Information System (INIS)

    Ijiri, Yuji; Sawada, Atsushi; Uchida, Masahiro; Ishiguro, Katsuhiko; Umeki, Hiroyuki; Sakamoto, Kazuhiko; Ohnishi, Yuzo

    2001-01-01

    It is important to take into account scale effects on fracture geometry if the modeling scale is much larger than the in-situ observation scale. The scale effect on fracture trace length, which is the most scale dependent parameter, is investigated using fracture maps obtained at various scales in tunnel and dam sites. We found that the distribution of fracture trace length follows negative power law distribution in regardless of locations and rock types. The hydraulic characteristics of fractured rock is also investigated by numerical analysis of discrete fracture network (DFN) model where power law distribution of fracture radius is adopted. We found that as the exponent of power law distribution become larger, the hydraulic conductivity of DFN model increases and the travel time in DFN model decreases. (author)

  3. Observations of a potential size-effect in experimental determination of the hydraulic properties of fractures

    International Nuclear Information System (INIS)

    Witherspoon, P.A.; Amick, C.H.; Gale, J.E.; Iwai, K.

    1979-05-01

    In several recent investigations, experimental studies on the effect of normal stress on the hydraulic conductivity of a single fracture were made on three rock specimens ranging in cross-sectional area from 0.02 m 2 to over 1.0 m 2 . At the maximum stress levels that could be attained (10 to 20 MPa), minimum values of the fracture hydraulic conductivity were not the same for each rock specimen. These minimum values increased with specimen size, indicating that the determination of fracture conductivity may be significantly influenced by a size effect. The implications of these results are important. Cores collected in the field are normally not larger than 0.15 m in diameter. However, the results of this work suggest that when this size core is used for laboratory investigations, the results may be nonconservative in that fracture permeabilities will be significantly lower than will be found in the field. 6 figures

  4. Effects of turbine's selection on hydraulic transients in the long pressurized water conveyance system

    International Nuclear Information System (INIS)

    Zhou, J X; Hu, M; Cai, F L; Huang, X T

    2014-01-01

    For a hydropower station with longer water conveyance system, an optimum turbine's selection will be beneficial to its reliable and stable operation. Different optional turbines will result in possible differences of the hydraulic characteristics in the hydromechanical system, and have different effects on the hydraulic transients' analysis and control. Therefore, the premise for turbine's selection is to fully understand the properties of the optional turbines and their effects on the hydraulic transients. After a brief introduction of the simulation models for hydraulic transients' computation and stability analysis, the effects of hydraulic turbine's characteristics at different operating points on the hydro-mechanical system's free vibration analysis were theoretically investigated with the hydraulic impedance analysis of the hydraulic turbine. For a hydropower station with long water conveyance system, based on the detailed hydraulic transients' computation respectively for two different optional turbines, the effects of the turbine's selection on hydraulic transients were analyzed. Furthermore, considering different operating conditions for each turbine and the similar operating conditions for these two turbines, free vibration analysis was comprehensively carried out to reveal the effects of turbine's impedance on system's vibration characteristics. The results indicate that, respectively with two different turbines, most of the controlling parameters under the worst cases have marginal difference, and few shows obvious differences; the turbine's impedances under different operating conditions have less effect on the natural angular frequencies; different turbine's characteristics and different operating points have obvious effects on system's vibration stability; for the similar operating conditions of these two turbines, system's vibration characteristics are basically consistent with

  5. Environmental effects monitoring at Cat Arm Hydraulic Development, Newfoundland, Canada

    International Nuclear Information System (INIS)

    Hill, E.L.

    1988-01-01

    The Cat Arm Dam is located on a plateau of the Long Range Mountains on Newfoundland's Great Northern Peninsula, and the 127 MW unit uses a 387 m head to produce an average of 676 GWh annually. Newfoundland and Labrador Hydro is conducting an environmental effects monitoring program in Cat Arm Reservoir to evaluate environmental impacts of the project. In the addendum to the Environmental Impact Statement of 1981, the utility agreed to a number of actions to mitigate the impacts of construction on fish populations, and to monitor the effects of reservoir creation, including the following. The mercury content of fish flesh, sediments and water would be monitored, and sampling would be undertaken prior to flooding to obtain baseline data, and for at least five years after flooding. The brook trout population would be monitored at various stages in the life of the reservoir in order to detect negative changes for which mitigative strategies could be applied. Alternative spawning habitat would be provided by removing barriers on streams or creating spawning beds if the monitoring program showed that recruitment was falling, and if these methods were ineffective, a compensatory stocking program would be considered. Extensive monitoring would be undertaken of the littoral zones, primary production in the reservoir, and of a number of limnological parameters to document long term changes in the reservoir. Although of academic interest, certain unusual characteristics of the Cat Arm reservoir, such as its low pH and dark colour, reduce its utility as a predictor of changes due to reservoir formation elsewhere in Newfoundland. 15 refs., 1 fig

  6. Thermal-Hydraulic Integral Effect Test with the ATLS for Investigation on CEDM Penetration Nozzle Integrity

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Kyoungho; Seokcho; Park, Hyunsik; Choi, Namhyun; Park, Yusun; Kim, Jongrok; Bae, Byounguhn; Kim, Yeonsik; Choi, Kiyong; Song, Chulhwa [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2013-05-15

    In this study, thermal-hydraulic integral effect test with the ATLAS (Advanced Thermal-Hydraulic Test Loop for Accident Simulation) was performed for simulating a failure of CEDM penetration nozzle. The main objectives of the present test were not only to provide physical insight into the system response during a failure of CEDM penetration nozzle but also to establish an integral effect test database for the validation of the safety analysis codes. Furthermore, present experimental data were utilized to resolve the safety issue raised by the PWSCC at the CEDM penetration nozzle of the YGN-3. Thermal-hydraulic integral effect test with the ATLAS was performed for simulating a failure of CEDM penetration nozzle. Failure of two penetration nozzles of the CEDM in the APR1400 was simulated. Initial and boundary conditions were determined with respect to the reference conditions of the APR1400. However, with an aim of corresponding to the YGN-3 situation, the safety injection water was supplied via CLI mode. Compared to the cold leg break SBLOCA, the consequences of the event were milder in terms of a loop seal clearance, break flow rate, collapsed water level, and PCT. This could be mainly attributed to the small break flow rate in case of the failure in the RPV upper head. Present experimental data were utilized to resolve the safety issue raised by the PWSCC at the CEDM penetration nozzle of the YGN-3.

  7. Effects from Unsaturated Zone Flow during Oscillatory Hydraulic Testing

    Science.gov (United States)

    Lim, D.; Zhou, Y.; Cardiff, M. A.; Barrash, W.

    2014-12-01

    In analyzing pumping tests on unconfined aquifers, the impact of the unsaturated zone is often neglected. Instead, desaturation at the water table is often treated as a free-surface boundary, which is simple and allows for relatively fast computation. Richards' equation models, which account for unsaturated flow, can be compared with saturated flow models to validate the use of Darcy's Law. In this presentation, we examine the appropriateness of using fast linear steady-periodic models based on linearized water table conditions in order to simulate oscillatory pumping tests in phreatic aquifers. We compare oscillatory pumping test models including: 1) a 2-D radially-symmetric phreatic aquifer model with a partially penetrating well, simulated using both Darcy's Law and Richards' Equation in COMSOL; and 2) a linear phase-domain numerical model developed in MATLAB. Both COMSOL and MATLAB models are calibrated to match oscillatory pumping test data collected in the summer of 2013 at the Boise Hydrogeophysical Research Site (BHRS), and we examine the effect of model type on the associated parameter estimates. The results of this research will aid unconfined aquifer characterization efforts and help to constrain the impact of the simplifying physical assumptions often employed during test analysis.

  8. Thermal hydraulic test of advanced fuel bundle with spectral shift rod (SSR) for BWR. Effect of thermal hydraulic parameters on steady state characteristics

    International Nuclear Information System (INIS)

    Kondo, Takao; Kitou, Kazuaki; Chaki, Masao; Ohga, Yukiharu; Makigami, Takeshi

    2011-01-01

    Japanese national project of next generation light water reactor (LWR) development started in 2008. Under this project, spectral shift rod (SSR) is being developed. SSR, which replaces conventional water rod (WR) of boiling water reactor (BWR) fuel bundle, was invented to enhance the BWR's merit, spectral shift effect for uranium saving. In SSR, water boils by neutron and gamma-ray direct heating and water level is formed as a boundary of the upper steam region and the lower water region. This SSR water level can be controlled by core flow rate, which amplifies the change of average core void fraction, resulting in the amplified spectral shift effect. This paper presents the steady state test results of the base geometry case in SSR thermal hydraulic test, which was conducted under the national project of next generation LWR. In the test, thermal hydraulic parameters, such as flow rate, pressure, inlet subcooling and heater rod power are changed to evaluate these effects on SSR water level and other SSR characteristics. In the test results, SSR water level rose as flow rate rose, which showed controllability of SSR water level by flow rate. The sensitivities of other thermal hydraulic parameters on SSR water level were also evaluated. The obtained data of parameter's sensitivities is various enough for the further analytical evaluation. The fluctuation of SSR water level was also measured to be small enough. As a result, it was confirmed that SSR's steady state performance was as planned and that SSR design concept is feasible. (author)

  9. HyRAM Testing Script.

    Energy Technology Data Exchange (ETDEWEB)

    Parkins, Owen

    2014-12-01

    The testing script is to provide a method of inspections to HyRAM (v1.0.0.244 Alpha) application features. This document will lead participants through the use of the application to make sure the application performs as designed. If a feature of the application becomes non-working, this script will relay useful information back to the designers of the application so that the feature can be fixed. This is essential to keep the application updated and performing as designed so that the users of this program can be satisfied. There will be frequent updates of this document to ensure proper testing of future application versions.

  10. Effects of radial diffuser hydraulic design on a double-suction centrifugal pump

    Science.gov (United States)

    Hou, H. C.; Zhang, Y. X.; Xu, C.; Zhang, J. Y.; Li, Z. L.

    2016-05-01

    In order to study effects of radial diffuser on hydraulic performance of crude oil pump, the steady CFD numerical method is applied and one large double-suction oil pump running in long-distance pipeline is considered. The research focuses on analysing the influence of its diffuser vane profile on hydraulic performance of oil pump. The four different types of cylindrical vane have been designed by in-house codes mainly including double arcs (DA), triple arcs (TA), equiangular spiral line (ES) and linear variable angle spiral line (LVS). During design process diffuser vane angles at inlet and outlet are tentatively given within a certain range and then the wrapping angle of the four types of diffuser vanes can be calculated automatically. Under the given inlet and outlet angles, the linear variable angle spiral line profile has the biggest wrapping angle and profile length which is good to delay channel diffusion but bring more friction hydraulic loss. Finally the vane camber line is thickened at the certain uniform thickness distribution and the 3D diffuser models are generated. The whole flow passage of oil pump with different types of diffusers under various flow rate conditions are numerically simulated based on RNG k-ɛ turbulent model and SIMPLEC algorithm. The numerical results show that different types of diffusers can bring about great difference on the hydraulic performance of oil pump, of which the ES profile diffuser with its proper setting angle shows the best hydraulic performance and its inner flow field is improved obviously. Compared with the head data from model sample, all designed diffusers can make a certain improvement on head characteristic. At the large flow rate conditions the hydraulic efficiency increases obviously and the best efficiency point shift to the large flow rate range. The ES profile diffuser embodies the better advantages on pump performance which can be explained theoretically that the diffuser actually acts as a diffusion

  11. Effect of the microstructure of mortars with low hydraulicity slag on their behavior in aggressive environments

    Directory of Open Access Journals (Sweden)

    Ahmed Hadj sadok

    2018-01-01

    Full Text Available Slag is one of the most used cement additives. Due to its latent hydraulic nature, attached to its hydraulicity, it can contribute to a microstructural modification and an improvement of the durability of the concrete face of aggressive environments. In this study, a low active slag is used in the manufacture of mortars as a substitute for cement, at a maximum rate of 50%. Firstly, a study of the microstructure with mercury porosimetry was used for determination of microstructural parameters (porosity, diameters and volume distribution. The behavior of mortars in aggressive environments (sodium and magnesium sulphate and seawater was studied later. Despite the low reactivity of studied slag, its presence especially at 50% rate, in the long term, has led to a refinement of the microstructure. This effect, among others, led to better resistivity of the mortars in the sulphate environnements.

  12. Fertilization with urea, ammonium and nitrate produce different effects on growth, hydraulic traits and drought tolerance in Pinus taeda seedlings.

    Science.gov (United States)

    Faustino, Laura I; Moretti, Ana P; Graciano, Corina

    2015-10-01

    Urea fertilization decreases Pinus taeda L. growth in clay soils of subtropical areas. The negative effect of urea is related to changes in some hydraulic traits, similar to those observed in plants growing under drought. The aims of this work were (i) to determine whether different sources of nitrogen applied as fertilizers produce similar changes in growth and hydraulic traits to those observed by urea fertilization and (ii) to analyze the impact of those changes in plant drought tolerance. Plants fertilized with urea, nitrate [Formula: see text] or ammonium [Formula: see text] were grown well watered or with reduced water supply. Urea and [Formula: see text] fertilization reduced plant growth and increased root hydraulic conductance scaled by root dry weight (DW). [Formula: see text] fertilization did not reduce plant growth and increased shoot hydraulic conductance and stem hydraulic conductivity. We conclude that [Formula: see text] is the ion involved in the changes linked to the negative effect of urea fertilization on P. taeda growth. [Formula: see text] fertilization does not change drought susceptibility and it produces changes in shoot hydraulic traits, therefore plants avoid the depressive effect of fertilization. Urea and [Formula: see text] fertilizers induce changes in DW and root hydraulic conductance and consequently plants are less affected by drought. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  13. Effect of the inlet throttling on the thermal-hydraulic instability of the natural circulation BWR

    International Nuclear Information System (INIS)

    Furuya, Masahiro; Inada, Fumio; Yoneda, Kimitoshi

    1997-01-01

    Although it is well-established that inlet restriction has a stabilizing for forced circulation BWR, the effect of inlet on the thermal-hydraulic stability of natural circulation BWR remains unknown since increasing inlet restriction affect thermal-hydraulic stability due to reduction of the recirculation flow rate. Therefore experiments have been conducted to investigate the effect of inlet restriction on the thermal-hydraulic stability. A test facility used in this experiments was designed and constructed to have non-dimensional values which are nearly equal to those of natural circulation BWR. Experimental results showed that driving force of the natural circulation was described as a function of heat flux and inlet subcooling independent of inlet restriction. Stability maps in reference to the channel inlet subcooling, heat flux were presented for various inlet restriction which were carried out by an analysis based on the homogeneous flow various using this function. Instability region during the inlet subcooling shifted to the higher inlet subcooling with increasing inlet restriction and became larger with increasing heat flux. (author)

  14. The effects of waste leachates on the hydraulic conductivity of natural clays

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez, F

    1989-01-01

    Sanitary land filling remains a viable alternative for disposal of the ever increasing volumes of municipal solid waste. Current landfill design practice requires the presence of a clay barrier (liner) that may consist of either a natural stratum or compacted clay borrow. The liner acts as a hydraulic barrier to control the flux of contaminants from the waste into the adjacent groundwater. In order to do this clay liners are required to have low hydraulic conductivity, k (typically 10{sup {minus}8} cm/s) that shall not increase during exposure to waste leachate. This thesis reports the assessment of compatibility between natural clays from Sarnia, Ontario, and various leachates ranging from municipal solid waste leachate to concentrated organic solvents. The studies were performed using specially designed fixed-ring permeameters that allowed controlling confining effective stresses, volume changes in the soil specimen and chemistry of the influent and effluent permeants. The Sarnia clays appeared to be compatible with domestic waste leachate, showing slight reductions in k. Extensive retardation of potassium from the leachate required long testing periods (up to twelve pore volumes) before the soils were deemed to be in chemical equilibrium. Concentrated, water-soluble organics (ethanol and dioxane) increased the hydraulic conductivity of compacted clays by 100 to 1,000-fold, thus destroying their effectiveness as liners. Water-compacted clays appeared remarkably resistant to penetration by concentrated hydrophobic solvents such as cyclohexane. Large hydraulic gradients (up to {approximately}900) were required to produce breakthrough along compaction induced fractures. However, alcohols and surfactants can facilitate the entry of hydrophobic liquids into the double layers causing large increased in k.

  15. Effects of prescribed burning on ecophysiological, anatomical and stem hydraulic properties in Pinus pinea L.

    Science.gov (United States)

    Battipaglia, Giovanna; Savi, Tadeja; Ascoli, Davide; Castagneri, Daniele; Esposito, Assunta; Mayr, Stefan; Nardini, Andrea

    2016-08-01

    Prescribed burning (PB) is a widespread management technique for wildfire hazard abatement. Understanding PB effects on tree ecophysiology is key to defining burn prescriptions aimed at reducing fire hazard in Mediterranean pine plantations, such as Pinus pinea L. stands. We assessed physiological responses of adult P. pinea trees to PB using a combination of dendroecological, anatomical, hydraulic and isotopic analyses. Tree-ring widths, xylem cell wall thickness, lumen area, hydraulic diameter and tree-ring δ(13)C and δ(18)O were measured in trees on burned and control sites. Vulnerability curves were elaborated to assess tree hydraulic efficiency or safety. Despite the relatively intense thermal treatment (the residence time of temperatures above 50 °C at the stem surface ranged between 242 and 2239 s), burned trees did not suffer mechanical damage to stems, nor significant reduction in radial growth. Moreover, the PB did not affect xylem structure and tree hydraulics. No variations in (13)C-derived water use efficiency were recorded. This confirmed the high resistance of P. pinea to surface fire at the stem base. However, burned trees showed consistently lower δ(18)O values in the PB year, as a likely consequence of reduced competition for water and nutrients due to the understory burning, which increased both photosynthetic activity and stomatal conductance. Our multi-approach analysis offers new perspectives on post-fire survival strategies of P. pinea in an environment where fires are predicted to increase in frequency and severity during the 21st century. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  16. Effect of biocrust: study of mechanical and hydraulic properties and erodibility

    Science.gov (United States)

    Slavík, Martin; Bruthans, Jiří; Schweigstillová, Jana

    2016-04-01

    It is well-known that lichens and other organisms forming crust on soil or rock surface play important role in weathering but may also protect underlying material from fast erosion. So far, there have been only few measurements comparing mechanical or hydraulic properties of biocrust with its subsurface on locked sand and friable sandstones, so the overall effect of the biocrust is not well-understood. Objective of our study is to quantify the effect of the biocrust on mechanical and hydraulic properties of friable sandstone and locked sand of Cretaceous age in six different localities with varying aspect and inclination and age of exposure in sandpit Strelec (Czech Rep.). On the artificial exposures, biocrust developed within last 10-30 years. Beside measurements of mechanical and hydraulic properties, SEM and mercury intrusion porosimetry in crust and subsurface was performed. Drilling resistance technique was found an excellent method to distinguish the biocrust from its subsurface (~3 mm thick biocrust has up to 12 times higher drilling resistance than underlying material). Surface zone with the biocrust has 3 - 25 times higher tensile strength than the subsurface material (1 - 25 kPa). In comparison with the subsurface, the biocrust is considerably less erodible (based on water jet testing). Biocrust saturated hydraulic conductivity is 15 - 240 times lower than the subsurface (6*10 -5 - 1*10 -4 m/s) and its permeability for water vapor is 4 - 9 times lower than subsurface. Presence of the biocrust slows down capillary absorption of water 4 - 25 times. The biocrust is thus forming firm surface which protects underlying material from rain and flowing water erosion and which considerably modifies its hydraulic properties. Material with crust exposed to calcination, leaching by concentrated peroxide and experiments with zymoliase enzyme strongly indicate that major contribution to crust hardening is provided by organic matter. Based on DNA sequencing the crust is

  17. Effects of subsoil compaction on hydraulic properties and preferential flow in a Swedish clay soil

    DEFF Research Database (Denmark)

    Mossadeghi-Björklund, M; Arvidsson, J.; Keller, Thomas

    2016-01-01

    in saturated hydraulic conductivity, air permeability and number of macropores at the second site. At this site, the traffic also significantly reduced the strength of preferential flow, presumably due to compaction-induced disruption of macropore continuity. In apparent contrast, some previous studies have shown......Soil compaction by vehicular traffic modifies the pore structure and soil hydraulic properties. These changes potentially influence the occurrence of preferential flow, which so far has been little studied. Our aim was to study the effect of compaction on soil hydraulic and transport properties...... transport derived from non-reactive tracer breakthrough curves and measurements of saturated hydraulic conductivity (Ks) and air permeability at the field moisture content (Ka). Although the traffic treatment did not cause any compaction effects at one of the two sites, it did result in significant reductions...

  18. The effect of inlet conditions on the air side hydraulic resistance and flow maldistribution in industrial air heaters

    International Nuclear Information System (INIS)

    Hoffmann-Vocke, Jonas; Neale, James; Walmsley, Michael

    2011-01-01

    Highlights: → Measured the effects of air heater inlet header geometry on hydraulic performance. → Measured the effects of inlet header flow maldistribution on hydraulic performance. → Inlet header flow maldistribution increases air heater system hydraulic resistance. - Abstract: Experimental system hydraulic resistance measurements on a scale air heater unit have highlighted the excessive hydraulic resistance of typical industry configurations. Both poor header inlet conditions and large header expansion angles are shown to contribute to system hydraulic resistance magnitudes 20-100% higher than suitable benchmark cases. Typical centrifugal fan system efficiencies well under 80% multiply the system resistance effects resulting in larger fan power penalties. Velocity profile measurements taken upstream and downstream of the test heat exchanger under flow maldistribution conditions provide insight into the flow maldistribution spreading caused by the heat exchanger resistance. The anisotropic resistance of the plate fin-and-tube heat exchanger is shown to result in resistance induced flow dispersion being concentrated in the axis parallel to the plate fins.

  19. Formation and hydraulic effects of deposits in high temperature sodium coolant systems

    International Nuclear Information System (INIS)

    Yunker, W.

    1976-01-01

    Deposition of sodium impurities in the high temperature (600 0 C), high flow (Reynolds Number approximately equal to 8 x 10 4 ) regions of a sodium coolant circuit is being studied to determine its possible hydraulic effects. Increases in flow impedance (pressure drop/volume flow 2 ) of up to 30 percent have been detected in an annular flow sensor. The apparatus and preliminary results of these tests are presented. Continuing tests are to specifically identify the materials involved and the system conditions under which the formations occur

  20. Software Tool for Automated Failure Modes and Effects Analysis (FMEA) of Hydraulic Systems

    DEFF Research Database (Denmark)

    Stecki, J. S.; Conrad, Finn; Oh, B.

    2002-01-01

    Offshore, marine,aircraft and other complex engineering systems operate in harsh environmental and operational conditions and must meet stringent requirements of reliability, safety and maintability. To reduce the hight costs of development of new systems in these fields improved the design...... management techniques and a vast array of computer aided techniques are applied during design and testing stages. The paper present and discusses the research and development of a software tool for automated failure mode and effects analysis - FMEA - of hydraulic systems. The paper explains the underlying...

  1. Effect of rock rheology on fluid leak- off during hydraulic fracturing

    Science.gov (United States)

    Yarushina, V. M.; Bercovici, D.; Oristaglio, M. L.

    2012-04-01

    In this communication, we evaluate the effect of rock rheology on fluid leak­off during hydraulic fracturing of reservoirs. Fluid leak-off in hydraulic fracturing is often nonlinear. The simple linear model developed by Carter (1957) for flow of fracturing fluid into a reservoir has three different regions in the fractured zone: a filter cake on the fracture face, formed by solid additives from the fracturing fluid; a filtrate zone affected by invasion of the fracturing fluid; and a reservoir zone with the original formation fluid. The width of each zone, as well as its permeability and pressure drop, is assumed to remain constant. Physical intuition suggests some straightforward corrections to this classical theory to take into account the pressure dependence of permeability, the compressibility or non-Newtonian rheology of fracturing fluid, and the radial (versus linear) geometry of fluid leak­off from the borehole. All of these refinements, however, still assume that the reservoir rock adjacent to the fracture face is non­deformable. Although the effect of poroelastic stress changes on leak-off is usually thought to be negligible, at the very high fluid pressures used in hydraulic fracturing, where the stresses exceed the rock strength, elastic rheology may not be the best choice. For example, calculations show that perfectly elastic rock formations do not undergo the degree of compaction typically seen in sedimentary basins. Therefore, pseudo-elastic or elastoplastic models are used to fit observed porosity profiles with depth. Starting from balance equations for mass and momentum for fluid and rock, we derive a hydraulic flow equation coupled with a porosity equation describing rock compaction. The result resembles a pressure diffusion equation with the total compressibility being a sum of fluid, rock and pore-space compressibilities. With linear elastic rheology, the bulk formation compressibility is dominated by fluid compressibility. But the possibility

  2. Hydraulic effects of unsealed boreholes. Numerical groundwater flow modelling of the Forsmark and Laxemar sites

    International Nuclear Information System (INIS)

    Bockgaard, Niclas

    2011-06-01

    The objective of the work was to investigate hydraulic effects of open and poorly sealed boreholes on groundwater flow conditions through simulations using a numerical groundwater model. Specifically, the boreholes KFM07A, KFM09A, and KFM09B in Forsmark and the boreholes KLX04, KLX06, and KLX10 in Laxemar were studied. The criteria for the selection of these boreholes were that the boreholes should represent typical conditions of the site, the borehole length should exceed 500 m, and that several major fractured zones should be intersected. The boreholes KFM07A and KLX06, respectively, were selected as reference boreholes for more detailed studies of different sealing schemes. The model setup of the Forsmark model followed the Forsmark 2.2 regional-scale conceptual hydrogeological model. The model domain was approximately 15 km (north-south) x 10 km (west- east) x 1.2 km (depth). The 131 deformation zones and three layers of superficial horizontal sheet joint were modelled deterministically. A stochastic discrete fracture network (DFN) representing fractures and minor deformation zones were also generated between the deterministic deformation zones inside central model volume. The side lengths of the square fractures were from 1,000 m down to 10 m. In order to resolve the details of flow in to and out from the borehole, a more detailed DFN was generated in a zone around the borehole KFM07A, where fractures down to a side length of 0.5 m were considered. The model setup of the Laxemar model followed the SDM-Site Laxemar (Laxemar 2.3) regional scale conceptual hydrogeological model. The model domain was approximately 12 km (north-south) x 20 km (west-east) x 2.1 km (depth). A number of 71 deformation zones were modelled deterministically, and one realization of a stochastic DFN, the so-called hydrogeological DFN model base case, was imported to the model. Similar to the Forsmark case, a more detailed DFN was also generated around the reference borehole KLX06. The

  3. Hydraulic effects of unsealed boreholes. Numerical groundwater flow modelling of the Forsmark and Laxemar sites

    Energy Technology Data Exchange (ETDEWEB)

    Bockgaard, Niclas [Golder Associates AB, Stockholm (Sweden)

    2011-06-15

    The objective of the work was to investigate hydraulic effects of open and poorly sealed boreholes on groundwater flow conditions through simulations using a numerical groundwater model. Specifically, the boreholes KFM07A, KFM09A, and KFM09B in Forsmark and the boreholes KLX04, KLX06, and KLX10 in Laxemar were studied. The criteria for the selection of these boreholes were that the boreholes should represent typical conditions of the site, the borehole length should exceed 500 m, and that several major fractured zones should be intersected. The boreholes KFM07A and KLX06, respectively, were selected as reference boreholes for more detailed studies of different sealing schemes. The model setup of the Forsmark model followed the Forsmark 2.2 regional-scale conceptual hydrogeological model. The model domain was approximately 15 km (north-south) x 10 km (west- east) x 1.2 km (depth). The 131 deformation zones and three layers of superficial horizontal sheet joint were modelled deterministically. A stochastic discrete fracture network (DFN) representing fractures and minor deformation zones were also generated between the deterministic deformation zones inside central model volume. The side lengths of the square fractures were from 1,000 m down to 10 m. In order to resolve the details of flow in to and out from the borehole, a more detailed DFN was generated in a zone around the borehole KFM07A, where fractures down to a side length of 0.5 m were considered. The model setup of the Laxemar model followed the SDM-Site Laxemar (Laxemar 2.3) regional scale conceptual hydrogeological model. The model domain was approximately 12 km (north-south) x 20 km (west-east) x 2.1 km (depth). A number of 71 deformation zones were modelled deterministically, and one realization of a stochastic DFN, the so-called hydrogeological DFN model base case, was imported to the model. Similar to the Forsmark case, a more detailed DFN was also generated around the reference borehole KLX06. The

  4. Effect of hydraulic hysteresis on the stability of infinite slopes under steady infiltration

    Science.gov (United States)

    Chen, Pan; Mirus, Benjamin B.; Lu, Ning; Godt, Jonathan W.

    2017-01-01

    Hydraulic hysteresis, including capillary soil water retention (SWR), air entrapment SWR, and hydraulic conductivity, is a common phenomenon in unsaturated soils. However, the influence of hydraulic hysteresis on suction stress, and subsequently slope stability, is generally ignored. This paper examines the influence of each of these three types of hysteresis on slope stability using an infinite slope stability analysis under steady infiltration conditions. First, hypothetical slopes for representative silty and sandy soils are examined. Then a monitored hillslope in the San Francisco Bay Area, California is assessed, using observed rainfall conditions and measured hydraulic and geotechnical properties of the colluvial soil. Results show that profiles of suction stress and the corresponding factor of safety are generally strongly affected by hydraulic hysteresis. Results suggest that each of the three types of hydraulic hysteresis may play a major role in the occurrence of slope failure, indicating that ignoring hydraulic hysteresis will likely lead to underestimates of failure potential and hence to inaccurate slope stability analysis.

  5. Numerical Investigation into the Effect of Natural Fracture Density on Hydraulic Fracture Network Propagation

    Directory of Open Access Journals (Sweden)

    Zhaohui Chong

    2017-07-01

    Full Text Available Hydraulic fracturing is an important method to enhance permeability in oil and gas exploitation projects and weaken hard roofs of coal seams to reduce dynamic disasters, for example, rock burst. It is necessary to fully understand the mechanism of the initiation, propagation, and coalescence of hydraulic fracture network (HFN caused by fluid flow in rock formations. In this study, a coupled hydro-mechanical model was built based on synthetic rock mass (SRM method to investigate the effects of natural fracture (NF density on HFN propagation. Firstly, the geometrical structures of NF obtained from borehole images at the field scale were applied to the model. Secondly, the micro-parameters of the proposed model were validated against the interaction between NF and hydraulic fracture (HF in physical experiments. Finally, a series of numerical simulations were performed to study the mechanism of HFN propagation. In addition, confining pressure ratio (CPR and injection rate were also taken into consideration. The results suggested that the increase of NF density drives the growth of stimulated reservoir volume (SRV, concentration area of injection pressure (CAIP, and the number of cracks caused by NF. The number of tensile cracks caused by rock matrix decrease gradually with the increase of NF density, and the number of shear cracks caused by rock matrix are almost immune to the change of NF density. The propagation orientation of HFN and the breakdown pressure in rock formations are mainly controlled by CPR. Different injection rates would result in a relatively big difference in the gradient of injection pressure, but this difference would be gradually narrowed with the increase of NF density. Natural fracture density is the key factor that influences the percentages of different crack types in HFN, regardless of the value of CPR and injection rate. The proposed model may help predict HFN propagation and optimize fracturing treatment designs in

  6. Ram and Buck Breeding Soundness Examination

    Directory of Open Access Journals (Sweden)

    Ahmed TIBARY

    2018-06-01

    Full Text Available Male breeding soundness examination (BSE is an important component of sheep and goat farming. BSE is best performed 2 months before the breeding season and is based on clinical and physical examination as well as sperm abnormalities detection. Rams are classified based on physical examination and semen evaluation finding in one of 4 categories: Unsatisfactory, questionable, satisfactory, and excellent. The satisfactory rams will achieve good reproductive performance if joined to ewes at a ratio of 1:50 for 60 days. However exceptional rams are expected to achieve good reproductive performance at a ratio of 1 ram to 100 ewes. For Buck, scrotal circumference should be at least 25 cm for breeds weighing more than 40 kg. Buck is deemed satisfactory breeder if he passes the physical examination, and has an ejaculate with at least 50% progressively motile spermatozoa and less than 30% total sperm abnormalities. This paper reviews factors affecting fertility, sperm production and quality as well as libido and mating ability in the ram. Details of genital examination and semen evaluation and interpretation of results are discussed. Classification of rams according to their reproductive potential is presented. Specific recommendations, when available for the buck, are highlighted. The main genital diseases are presented. The most frequent culling reason for ram is epididymitis due to Brucella ovis. Systematic culling of rams with epididymitis improves flock lambing rates by 10 to 15%. Overall, the examination of the reproductive capacity in the ram and the buck is an important tool for improvement of flocks/herds fertility and prevention of contagious or hereditary diseases.

  7. Effects of volume change on the unsaturated hydraulic conductivity of Sphagnum moss

    Science.gov (United States)

    Golubev, V.; Whittington, P.

    2018-04-01

    Due to the non-vascular nature of Sphagnum mosses, the capitula (growing surface) of the moss must rely solely on capillary action to receive water from beneath. Moss subsides and swells in accordance with water table levels, an effect called "mire-breathing", which has been thought to be a self-preservation mechanism, although no systematic studies have been done to demonstrate exactly how volume change affects hydrophysical properties of moss. In this study, the unsaturated hydraulic conductivity (Kunsat) and water content of two different species of Sphagnum moss were measured at different compression rates, up to the maximum of 77%. The findings show that the Kunsat increases by up to an order of magnitude (10×) with compression up to a certain bulk density of the moss, after which higher levels of compression result in lowered unsaturated hydraulic conductivity. This was coupled with an increase in soil water retention with increased compression. The increase of the Kunsat with compression suggests that the mire-breathing effect should be considered a self-preservation mechanism to provide sufficient amount of water to growing moss in times of low water availability.

  8. Photoinhibition of stem elongation by blue and red light: effects on hydraulic and cell wall properties

    Science.gov (United States)

    Kigel, J.; Cosgrove, D. J.

    1991-01-01

    The underlying mechanism of photoinhibition of stem elongation by blue (BL) and red light (RL) was studied in etiolated seedlings of pea (Pisum sativum L. cv Alaska). Brief BL irradiations resulted in fast transient inhibition of elongation, while a delayed (lag approximately 60 minutes) but prolonged inhibition was observed after brief RL. Possible changes in the hydraulic and wall properties of the growing cells during photoinhibition were examined. Cell sap osmotic pressure was unaffected by BL and RL, but both irradiations increased turgor pressure by approximately 0.05 megapascal (pressure-probe technique). Cell wall yielding was analyzed by in vivo stress relaxation (pressure-block technique). BL and RL reduced the initial rate of relaxation by 38 and 54%, while the final amount of relaxation was decreased by 48 and 10%, respectively. These results indicate that RL inhibits elongation mainly by lowering the wall yield coefficient, while most of the inhibitory effect of BL was due to an increase of the yield threshold. Mechanical extensibility of cell walls (Instron technique) was decreased by BL and RL, mainly due to a reduction in the plastic component of extensibility. Thus, photoinhibitions of elongation by both BL and RL are achieved through changes in cell wall properties, and are not due to effects on the hydraulic properties of the cell.

  9. Effect of Initial Hydraulic Conditions on Capillary Rise in a Porous Medium: Pore-Network Modeling

    KAUST Repository

    Joekar-Niasar, V.

    2012-01-01

    The dynamics of capillary rise in a porous medium have been mostly studied in initially dry systems. As initial saturation and initial hydraulic conditions in many natural and industrial porous media can be variable, it is important to investigate the influence of initial conditions on the dynamics of the process. In this study, using dynamic pore-network modeling, we simulated capillary rise in a porous medium for different initial saturations (and consequently initial capillary pressures). Furthermore, the effect of hydraulic connectivity of the wetting phase in corners on the height and velocity of the wetting front was studied. Our simulation results show that there is a trade-off between capillary forces and trapping due to snap-off, which leads to a nonlinear dependence of wetting front velocity on initial saturation at the pore scale. This analysis may provide a possible answer to the experimental observations in the literature showing a non-monotonic dependency between initial saturation and the macroscopic front velocity. © Soil Science Society of America.

  10. Thermal-hydraulics stability of natural circulation BWR under startup. Flashing effects

    International Nuclear Information System (INIS)

    Hu, Rui; Kazimi, Mujid S.

    2009-01-01

    To help achieve the necessary natural circulation flow, a fairly long chimney is installed in a boiling natural circulation reactor like the ESBWR. In such systems, thermal-hydraulic stability during low pressure start-up should be examined while considering the flashing induced by the pressure drop in the channel and the chimney due to gravity head. In this work, a BWR stability analysis code in the frequency domain, named FISTAB (Flashing-Induced STability Analysis for BWR), was developed to address the issue of flashing-induced instability. A thermal-hydraulics non-homogeneous equilibrium model (NHEM) based on a drift flux formulation along with a lumped fuel dynamics model is incorporated in the work. The vapor generation rate is derived from the mixture energy conservation equation while considering the effect of flashing. The functionality of the FISTAB code was confirmed by comparison to experimental results from SIRIUS-N facility at CRIEPI, Japan. Both stationary and perturbation results agree well with the experimental results. (author)

  11. Hydraulic structures

    CERN Document Server

    Chen, Sheng-Hong

    2015-01-01

    This book discusses in detail the planning, design, construction and management of hydraulic structures, covering dams, spillways, tunnels, cut slopes, sluices, water intake and measuring works, ship locks and lifts, as well as fish ways. Particular attention is paid to considerations concerning the environment, hydrology, geology and materials etc. in the planning and design of hydraulic projects. It also considers the type selection, profile configuration, stress/stability calibration and engineering countermeasures, flood releasing arrangements and scouring protection, operation and maintenance etc. for a variety of specific hydraulic structures. The book is primarily intended for engineers, undergraduate and graduate students in the field of civil and hydraulic engineering who are faced with the challenges of extending our understanding of hydraulic structures ranging from traditional to groundbreaking, as well as designing, constructing and managing safe, durable hydraulic structures that are economical ...

  12. Individual and combined effects of organic, toxic, and hydraulic shocks on sequencing batch reactor in treating petroleum refinery wastewater

    Energy Technology Data Exchange (ETDEWEB)

    Mizzouri, Nashwan Sh., E-mail: nashwan_mizzouri@yahoo.com [Department of Civil Engineering, University of Malaya, Lembah Pantai, 50603 Kuala Lumpur (Malaysia); Department of Civil Engineering, University of Duhok, Kurdistan (Iraq); Shaaban, Md Ghazaly [Department of Civil Engineering, University of Malaya, Lembah Pantai, 50603 Kuala Lumpur (Malaysia)

    2013-04-15

    Highlights: ► This research focuses on the combined impact of shock loads on the PRWW treatment. ► System failure resulted when combined shock of organic and hydraulic was applied. ► Recovery was achieved by replacing glucose with PRWW and OLR was decreased to half. ► Worst COD removals were 68.9, and 57.8% for organic, and combined shocks. -- Abstract: This study analyzes the effects of toxic, hydraulic, and organic shocks on the performance of a lab-scale sequencing batch reactor (SBR) with a capacity of 5 L. Petroleum refinery wastewater (PRWW) was treated with an organic loading rate (OLR) of approximately 0.3 kg chemical oxygen demand (COD)/kg MLSS d at 12.8 h hydraulic retention time (HRT). A considerable variation in the COD was observed for organic, toxic, hydraulic, and combined shocks, and the worst values observed were 68.9, 77.1, 70.2, and 57.8%, respectively. Improved control of toxic shock loads of 10 and 20 mg/L of chromium (VI) was identified. The system was adversely affected by the organic shock when a shock load thrice the normal value was used, and this behavior was repeated when the hydraulic shock was 4.8 h HRT. The empirical recovery period was greater than the theoretical period because of the inhibitory effects of phenols, sulfides, high oil, and grease in the PRWW. The system recovery rates from the shocks were in the following order: toxic, organic, hydraulic, and combined shocks. System failure occurred when the combined shocks of organic and hydraulic were applied. The system was resumed by replacing the PRWW with glucose, and the OLR was reduced to half its initial value.

  13. Effect of fin-endwall fillet on thermal hydraulic performance of airfoil printed circuit heat exchanger

    International Nuclear Information System (INIS)

    Ma, Ting; Xin, Fei; Li, Lei; Xu, Xiang-yang; Chen, Yi-tung; Wang, Qiu-wang

    2015-01-01

    Printed circuit heat exchanger (PCHE) is recommended to be used for intermediate heat exchanger in Very High Temperature Reactor (VHTR). One of the key features is that it is manufactured by the photochemical etching in order to maintain the internal structure and metal properties. In this paper, a photochemical etching experiment is conducted to manufacture the airfoil PCHE plate. The result indicates that the airfoil fin is not an ideal airfoil profile, but has a fin-endwall fillet. For the purpose of simplifying the numerical model and saving computational time, a validated model with a single fluid is used to further study the effect of fin-endwall fillet on the thermal hydraulic performance of airfoil PCHE. It is found that the fin-endwall fillet can increase the heat transfer and pressure drop in the cases with the non-dimensional longitudinal pitch being 1.63. The effect of fin-endwall fillet on thermal hydraulic performance decreases with the increase of transverse pitch, but the longitudinal pitch has little effect when the non-dimensional longitudinal pitch is greater than 1.88. In the studied cases, the maximum difference of Nusselt number and friction factor between the two models with and without fin-endwall fillet is up to 6.7% and 6.4%. - Highlights: • Fillets are formed in the endwall of airfoil fins during the photochemical etching. • Two-fluid model can be replaced by single-fluid model to perform simulation. • Fin-endwall fillet can increase heat transfer and pressure drop at ζ_l = 1.63. • Effect of fin-endwall fillet decreases as transverse pitch increases at ζ_l = 1.63. • Longitudinal pitch has little effect at ζ_l ≥ 1.88.

  14. Energy-Saving RAM-Power Tap

    Science.gov (United States)

    Bruner, Alan Roy

    1987-01-01

    Reverse-flow HEXFET(R) minimizes voltage drop and power dissipation. HEXFET(R) scheme reduces voltage drop by approximately 80 percent. Design for power tap for random-access memory (RAM) has potential application in digital systems.

  15. Effect of urea treatment on the nutritive value of local sorghum and millet straw: a comparative study on growing performance of Djallonke rams

    Directory of Open Access Journals (Sweden)

    A.B. Kanwe

    2010-04-01

    Full Text Available Two tons of and chopped millet and sorghum straws have been treated with an urea solution at 5% (100 kg of straw, sprinkled with 50 lt. of solution. Treated straws were used as basic diet (900 g day associated to 100 g of cotton cake for 24 growing Djallonke rams in comparison to non treated straws. Four groups of animals were fed for 98 days with: urea treated sorghum (UTSS, not treated sorghum straw (NTSS, treated millet (UTMS, non treated millet straw (NTMS. Treated straws presented an increase of NDF of about 9%, of total nitrogen from 2 to 3 times while digestibility of dry matter increased respectively by 8,8% and 23,0% respectively in treated sorghum and millet. Also dry matter intake increased by 4,5% and 15,5% for treated sorghum and millet respectively compared to non treated. Mean weekly weight gain were significantly higher (P<0.05 for UTSS e UTMS compared to NTSS e NTMS. While the weekly weight gain, did not differed between UTSS vs. UTMS and NTSS vs. NTMS. At the end of the trial the UTSS and UTMS group presented a weight gain of about 40% and 38.7%, of their initial weight; while the gain for both NTSS and NTMS was respectively of 31.1% and 29.5%.

  16. Shallow water effects on wave energy converters with hydraulic power take-off system

    Directory of Open Access Journals (Sweden)

    Ashank Sinha

    2016-12-01

    Full Text Available The effect of water depth on the power absorption by a single heaving point absorber wave energy converter, attached to a hydraulic power take-off system, is simulated and analysed. The wave energy flux for changing water depths is presented and the study is carried out at a location in the north-west Portuguese coast, favourable for wave power generation. This analysis is based on a procedure to modify the wave spectrum as the water depth reduces, namely, the TMA spectrum (Transformation spectrum. The present study deals with the effect of water depth on the spectral shape and significant wave heights. The reactive control strategy, which includes an external damping coefficient and a negative spring term, is used to maximize power absorption by the wave energy converter. The presented work can be used for making decisions regarding the best water depth for the installation of point absorber wave energy converters in the Portuguese nearshore.

  17. Precipitation of calcium sulphate on hot walls - influence of impurities, thermal and hydraulic effects

    International Nuclear Information System (INIS)

    Guillermin, Roger

    1973-01-01

    After some generalities on desalination by distillation processes and on problems due to scaling, this research thesis aims at a better understanding of the formation of deposits and their effects in the case of precipitation of calcium sulphate hemihydrate which precipitates above 100 C in pure solution and between 100 and 300 C in brine. Deposit growth, influence of impurities, and influence of the deposit on heat exchange and loss of load are the main issues of this research. The author addresses general principles of salt crystallization and the thermodynamic and kinetic aspects of calcium sulphate precipitation, studies the growth kinetics of the calcium sulphate hemihydrate in a transient concentration regime, reports the study of thermal and hydraulic effects of the formation of a hemihydrate deposit, notably by discussing the different phases involved in the covering of a metallic surface

  18. RAMS (Risk Analysis - Modular System) methodology

    Energy Technology Data Exchange (ETDEWEB)

    Stenner, R.D.; Strenge, D.L.; Buck, J.W. [and others

    1996-10-01

    The Risk Analysis - Modular System (RAMS) was developed to serve as a broad scope risk analysis tool for the Risk Assessment of the Hanford Mission (RAHM) studies. The RAHM element provides risk analysis support for Hanford Strategic Analysis and Mission Planning activities. The RAHM also provides risk analysis support for the Hanford 10-Year Plan development activities. The RAMS tool draws from a collection of specifically designed databases and modular risk analysis methodologies and models. RAMS is a flexible modular system that can be focused on targeted risk analysis needs. It is specifically designed to address risks associated with overall strategy, technical alternative, and `what if` questions regarding the Hanford cleanup mission. RAMS is set up to address both near-term and long-term risk issues. Consistency is very important for any comparative risk analysis, and RAMS is designed to efficiently and consistently compare risks and produce risk reduction estimates. There is a wide range of output information that can be generated by RAMS. These outputs can be detailed by individual contaminants, waste forms, transport pathways, exposure scenarios, individuals, populations, etc. However, they can also be in rolled-up form to support high-level strategy decisions.

  19. Effect of depletion of interstitial hyaluronan on hydraulic conductance in rabbit knee synovium

    Science.gov (United States)

    Coleman, P J; Scott, D; Abiona, A; Ashhurst, D E; Mason, R M; Levick, J R

    1998-01-01

    The hydraulic resistance of the synovial lining to fluid outflow from a joint cavity () is important for the retention of intra-articular lubricant. The resistance has been attributed in part to extracellular glycosaminoglycans, including hyaluronan and chondroitin sulphates. Increased permeability in joints infused with testicular hyaluronidase, which digests both chondroitin sulphates and hyaluronan, supports this view. In this study the importance of interstitial hyaluronan per se was assessed using leech and Streptomyces hyaluronidases, which degrade only hyaluronan. Ringer solution was infused into the knee joint cavity of anaesthetized rabbits for 30 min, with or without hyaluronidase, after which intra-articular pressure (Pj) was raised and the relation between pressure and outflow determined. Treatment with Streptomyces, leech or testicular hyaluronidases increased the fluid escape rates by similar factors, namely 4- to 6-fold. After Streptomyces hyaluronidase treatment the slope d/dPj, which at low pressures represents synovial hydraulic conductance, increased from a control of 0.90 ± 0.20 μl min−1 cmH2O−1 (mean ± s.e.m., n = 6) to 4.52 ± 0.70 μl min−1 cmH2O−1. The slope d/dPj increased to a similar level after testicular hyaluronidase, namely to 4.14 ± 1.06 μl min−1 cmH2O−1 (control, 0.54 ± 0.24 μl min−1 cmH2O−1). Streptomyces and leech hyaluronidases were as effective as testicular hyaluronidase (no statistically significant differences) despite differences in substrate specificity. It was shown using histochemical and immunohistochemical techniques that hyaluronan was removed from the synovium by leech, Streptomyces and testicular hyaluronidases. The binding of antibodies 2-B-6 and 3-B-3 showed that the core proteins of the chondroitin sulphate proteoglycans remained intact after treatment with hyaluronidases, and the binding of 5-D-4 showed that keratan sulphate was unaffected. An azocasein digestion assay confirmed that the

  20. The Effect of Loading Rate on Hydraulic Fracturing in Synthetic Granite - a Discrete Element Study

    Science.gov (United States)

    Tomac, I.; Gutierrez, M.

    2015-12-01

    Hydraulic fracture initiation and propagation from a borehole in hard synthetic rock is modeled using the two dimensional Discrete Element Method (DEM). DEM uses previously established procedure for modeling the strength and deformation parameters of quasi-brittle rocks with the Bonded Particle Model (Itasca, 2004). A series of simulations of laboratory tests on granite in DEM serve as a reference for synthetic rock behavior. Fracturing is enabled by breaking parallel bonds between DEM particles as a result of the local stress state. Subsequent bond breakage induces fracture propagation during a time-stepping procedure. Hydraulic fracturing occurs when pressurized fluid induces hoop stresses around the wellbore which cause rock fracturing and serves for geo-reservoir permeability enhancement in oil, gas and geothermal industries. In DEM, a network of fluid pipes and reservoirs is used for mathematical calculation of fluid flow through narrow channels between DEM particles, where the hydro-mechanical coupling is fully enabled. The fluid flow calculation is superimposed with DEM stress-strain calculation at each time step. As a result, the fluid pressures during borehole pressurization in hydraulic fracturing, as well as, during the fracture propagation from the borehole, can be simulated. The objective of this study is to investigate numerically a hypothesis that fluid pressurization rate, or the fluid flow rate, influences upon character, shape and velocity of fracture propagation in rock. The second objective is to better understand and define constraints which are important for successful fracture propagation in quasi-brittle rock from the perspective of flow rate, fluid density, viscosity and compressibility relative to the rock physical properties. Results from this study indicate that not only too high fluid flow rates cause fracture arrest and multiple fracture branching from the borehole, but also that the relative compressibility of fracturing fluid and

  1. Effect of a ballast zone on the hydraulic stability of a single-pass steam generator

    International Nuclear Information System (INIS)

    Belyakov, I.I.; Kvetnyj, M.A.; Loginov, D.A.

    1985-01-01

    A new mechanism of hydraulic instability of boiling channels with convection heating which reveals in the presence of a developed ballast zone at decreased loads of a counterflan steam generator operation is considered. It is shown that for the certain combinations of thermal and technical parameters pulsation regimes caused by the ballast zone displacement over the heating surface are possible. The parameter relation at which the ballast zone position becomes unstable is obtained. The effect of the ballast zone on the statis steam generator stability is established. A mechanism of whole-circuit pulsations revealed when developing start regimes of single-pass steam generator heated with liquid sodium is explained from the positions of the instability

  2. Treated wastewater irrigation effects on soil hydraulic conductivity and aggregate stability of loamy soils in Israel

    Directory of Open Access Journals (Sweden)

    Schacht Karsten

    2015-03-01

    Full Text Available The use of treated wastewater (TWW for agricultural irrigation becomes increasingly important in water stressed regions like the Middle East for substituting fresh water (FW resources. Due to elevated salt concentrations and organic compounds in TWW this practice has potential adverse effects on soil quality, such as the reduction of hydraulic conductivity (HC and soil aggregate stability (SAS. To assess the impact of TWW irrigation in comparison to FW irrigation on HC, in-situ infiltration measurements using mini disk infiltrometer were deployed in four different long-term experimental orchard test sites in Israel. Topsoil samples (0-10 cm were collected for analyzing SAS and determination of selected soil chemical and physical characteristics.

  3. Hydraulic noise in reactor circuits and loops, and its effect on nuclear fuel vibration

    International Nuclear Information System (INIS)

    Card, D.C.

    This paper reports the results of an investigation at WNRE to monitor noise levels in reactor circuits and loops, so as to characterize the systems and establish the importance of this noise on fuel and pressure tube vibration. Some of the techniques necessary for in-reactor installations of pressure transducers have been developed and measurements have been obtained in the vertical fuel channels of a very noisy out-reactor loop as well as in the WR-1 reactor circuits. A very quiet out-reactor loop has been constructed to study the vibration behaviour of 37-element fuel bundles in the horizontal CANDU pressurized-heavy water reactor systems. In this facility various types and levels of hydraulic noise are being generated to study their effect on the fuel bundles and flow tube at flow velocities up to approximately 13 m/s. (author)

  4. Hydraulic turbines

    International Nuclear Information System (INIS)

    Meluk O, G.

    1998-01-01

    The hydraulic turbines are defined according to the specific speed, in impulse turbines and in reaction turbines. Currently, the Pelton turbines (of impulse) and the Francis and Kaplan turbines (of reaction), they are the most important machines in the hydroelectric generation. The hydraulic turbines are capable of generating in short times, large powers, from its loads zero until the total load and reject the load instantly without producing damages in the operation. When the hydraulic resources are important, the hydraulic turbines are converted in the axle of the electric system. Its combination with thermoelectric generation systems, it allow the continuing supply of the variations in demand of energy system. The available hydraulic resource in Colombia is of 93085 MW, of which solely 9% is exploited, become 79% of all the electrical country generation, 21% remaining is provided by means of the thermoelectric generation

  5. Effects of Using Dorper, Hampshire Down, Bluefaced Leicester and German Blackheaded Rams as Terminal Sires in Extensive Low-Input Production Systems

    Directory of Open Access Journals (Sweden)

    Dinu Gavojdian

    2017-05-01

    Full Text Available The current study was conducted to evaluate Dorper, Hampshire Down, Bluefaced Leicester and German Blackheaded breeds as terminal sires in an extensive low-input production system under European temperate conditions, when crossed with native Turcana breed as a maternal genotype. The project breeding herd consisted of 300 multiparous purebred Turcana ewes, managed under extensive low-input production system. Six breeding herds were set-up, with randomly selected ewes (50/group being exposed to Dorper, Hampshire Down, Bluefaced Leicester, German Blackheaded and Turcana (control group rams. Lambs birth weight was influenced (p≤0.01 for the F1 Hampshire Down x Turcana and F1 German Blackheaded x Turcana crossbreds, compared to their counterparts. Lamb survival from birth to weaning was the lowest (88.4±3.30% for the Dorper sired lambs, and the highest (94.0±1.84% in the Bluefaced Leicester sired lambs (p≤0.01. Hampshire Down and German Blackheaded sired lambs had similar survival rates as the purebreds Turcana lambs (p>0.05. Body weight of lambs at the age of 8 months was significantly higher (p≤0.001 in Dorper (41.3±0.51, Bluefaced Leicester (41.2±0.34 and German Blackheaded (42.4±0.58 sired genotypes, while the Hampshire Down half-breeds (39.3±0.65 had intermediate body weights (p≤0.01 compared to the controls (34.6±0.49 and the better performing genotypes.

  6. Assessing Tillage Effects on Soil Hydraulic Properties via Inverse Parameter Estimation using Tension Infiltrometry

    Science.gov (United States)

    Schwen, Andreas; Bodner, Gernot; Loiskandl, Willibald

    2010-05-01

    Hydraulic properties are key factors controlling water and solute movement in soils. While several recent studies have focused on the assessment of the spatial variability of hydraulic properties, the temporal dynamics are commonly not taken into account, primarily because its measurement is costly and time-consuming. However, there is extensive empirical evidence that these properties are subject to temporal changes, particularly in the near-saturated range where soil structure strongly influences water flow. One main source of temporal variability is soil tillage. It can improve macroporosity by loosening the soil and thereby changing the pore-size distribution. Since these modifications are quite unstable over time, the pore space partially collapses after tillage. This effect should be largest for conventional tillage (CT), where the soil is ploughed after harvest every year. Assessing the effect of different tillage treatments on the temporal variability of hydraulic properties requires adequate measurement techniques. Tension infiltrometry has become a popular and convenient method providing not only the hydraulic conductivity function but also the soil rentention properties. The inverse estimation of parameters from infiltration measurements remains challenging, despite some progress since the first approach of Šimůnek et al. (1998). Measured data like the cumulative infiltration, the initial and final volumetric water content, as well as independently measured retention data from soil core analysis with laboratory methods, have to be considered to find an optimum solution describing the soil's pore space. In the present study we analysed tension infiltration measurements obtained several times between August 2008 and December 2009 on an arable field in the Moravian Basin, Lower Austria. The tillage treatments were conventional tillage including ploughing (CT), reduced tillage with chisel only (RT), and no-tillage treatment using a direct seeding

  7. Sample dimensions effect on prediction of soil water retention curve and saturated hydraulic conductivity

    Science.gov (United States)

    Soil water retention curve (SWRC) and saturated hydraulic conductivity (SHC) are key hydraulic properties for unsaturated zone hydrology and groundwater. Not only are the SWRC and SHC measurements time-consuming, their results are scale dependent. Although prediction of the SWRC and SHC from availab...

  8. PWR Blowdown Heat Transfer Separate-Effects Program. Thermal-Hydraulic Test Facility experimental data report for test 166S

    International Nuclear Information System (INIS)

    Clemons, V.D.; White, M.D.; Hedrick, R.A.

    1978-01-01

    Reduced instrument responses are presented for Thermal-Hydraulic Test Facility (THTF) test 166S, which is part of the ORNL Pressurized-Water Reactor (PWR) Blowdown Heat Transfer Separate-Effects Program. The objective of the program is to investigate the thermal-hydraulic phenomenon governing the energy transfer and transport processes that occur during a loss-of-coolant accident in a PWR system. Test 166S was conducted to obtain thermal-hydraulic and CHF information in THTF bundle 1 with an intact hot leg. The primary purpose of this report is to make the reduced instrument responses during tests 166S available. These are presented in graphical form in engineering units and have been analyzed only to the extent necessary to ensure reasonableness and consistency

  9. High bulk modulus of ionic liquid and effects on performance of hydraulic system.

    Science.gov (United States)

    Kambic, Milan; Kalb, Roland; Tasner, Tadej; Lovrec, Darko

    2014-01-01

    Over recent years ionic liquids have gained in importance, causing a growing number of scientists and engineers to investigate possible applications for these liquids because of their unique physical and chemical properties. Their outstanding advantages such as nonflammable liquid within a broad liquid range, high thermal, mechanical, and chemical stabilities, low solubility for gases, attractive tribological properties (lubrication), and very low compressibility, and so forth, make them more interesting for applications in mechanical engineering, offering great potential for new innovative processes, and also as a novel hydraulic fluid. This paper focuses on the outstanding compressibility properties of ionic liquid EMIM-EtSO4, a very important physical chemically property when IL is used as a hydraulic fluid. This very low compressibility (respectively, very high Bulk modulus), compared to the classical hydraulic mineral oils or the non-flammable HFDU type of hydraulic fluids, opens up new possibilities regarding its usage within hydraulic systems with increased dynamics, respectively, systems' dynamic responses.

  10. Ageing of fibre reinforced polymer composite selected as a bearing material for Rams of 540 MWe fuelling machine

    International Nuclear Information System (INIS)

    Limaye, P.K.; Soni, N.L.; Agrawal, R.G.

    2006-01-01

    Fibre-reinforced-polymer-composite material has been suggested as a bearing material to overcome tribological problems witnessed during the testing of Ram assembly of the 540 MWe fuelling machine at RTD. After successful trials at B-Ram the composite material has been adapted for B-RAM, C-Ram and RDB head at fuelling machines being tested at RTD, Hall 7 and at Tarapur. Laboratory evaluations were also carried out at Tribology Lab RTD to study effect of radiation on the composite. Paper deals with the various aspects of life prediction of this material in term of wear and radiation damage. (author)

  11. PWR blowdown heat transfer separate-effects program: thermal-hydraulic test facility experimental data report for test 104

    International Nuclear Information System (INIS)

    Leon, D.M.; White, M.D.; Moore, P.A.; Hedrick, R.A.

    1978-01-01

    Reduced instrument responses are presented for Thermal-Hydraulic Test Facility (THTF) test 104, which is part of the ORNL Pressurized-Water Reactor (PWR) Blowdown Heat Transfer Separate-Effects Program. The objective of the program is to investigate the thermal-hydraulic phenomenon governing the energy transfer and transport processes that occur during a loss-of-coolant accident in the PWR system. Test 104 was conducted to obtain CHF in bundle 1 under blowdown conditions. The primary purpose of this report is to make the reduced instrument responses during test 104 available

  12. Hydraulic activity of belite cement from class C coal fly ash. Effect of curing and admixtures

    Directory of Open Access Journals (Sweden)

    Guerrero, A.

    2006-09-01

    Full Text Available The effect of curing method and a water-reducing additive on the hydraulic activity of high lime content (ASTM type C fly ash belite cement (FABC-2-W is reported. A class C fly ash was subjected to hydrothermal treatment and subsequent calcination to synthesize FABC. Hydraulic activity was evaluated in the cement paste over 180 days from the physically bound water content as determined by thermogravimetric analysis and the degree of hydration, in turn found with X-ray diffraction (XRD analysis. Mechanical strength, porosity and pore size distribution were also studied in equivalent mortar samples.En este trabajo se discute la influencia del tipo de curado y de un aditivo reductor de la demanda de agua en la actividad hidráulica de un cemento belítico de cenizas volantes de alto contenido en cal denominado (CBCV-2-A. Este cemento ha sido sintetizado por una ruta húmeda hidrotermal con posterior calcinación, empleando ceniza volante de alto contenido en cal (ASTM tipo C como materia prima. La actividad hidráulica se ha estudiado en la pasta de cemento, durante un periodo de 180 días, por medio del contenido de agua combinada, determinada por análisis termogravimétrico, y el grado de hidratación por difracción de rayos X (DRX. La resistencia mecánica y la porosidad total y distribución de tamaño de poro se han estudiado en probetas equivalentes de mortero

  13. The effect on stability and thermal hydraulic quenchback of perforating the jacket of a cable-in-conduit conductor

    International Nuclear Information System (INIS)

    Dresner, L.

    1994-01-01

    This Paper continues earlier work on the reduction of the quench pressure in a doubler cable-in-conduit conductor achieved by perforating the inner jacket. The present study examines the effect of the perforations on the stability margin and on the ononset of thermal hydraulic quenchback

  14. FPS-RAM: Fast Prefix Search RAM-Based Hardware for Forwarding Engine

    Science.gov (United States)

    Zaitsu, Kazuya; Yamamoto, Koji; Kuroda, Yasuto; Inoue, Kazunari; Ata, Shingo; Oka, Ikuo

    Ternary content addressable memory (TCAM) is becoming very popular for designing high-throughput forwarding engines on routers. However, TCAM has potential problems in terms of hardware and power costs, which limits its ability to deploy large amounts of capacity in IP routers. In this paper, we propose new hardware architecture for fast forwarding engines, called fast prefix search RAM-based hardware (FPS-RAM). We designed FPS-RAM hardware with the intent of maintaining the same search performance and physical user interface as TCAM because our objective is to replace the TCAM in the market. Our RAM-based hardware architecture is completely different from that of TCAM and has dramatically reduced the costs and power consumption to 62% and 52%, respectively. We implemented FPS-RAM on an FPGA to examine its lookup operation.

  15. Basic hydraulics

    CERN Document Server

    Smith, P D

    1982-01-01

    BASIC Hydraulics aims to help students both to become proficient in the BASIC programming language by actually using the language in an important field of engineering and to use computing as a means of mastering the subject of hydraulics. The book begins with a summary of the technique of computing in BASIC together with comments and listing of the main commands and statements. Subsequent chapters introduce the fundamental concepts and appropriate governing equations. Topics covered include principles of fluid mechanics; flow in pipes, pipe networks and open channels; hydraulic machinery;

  16. A study of environmental radon levels in rammed earth dwellings in the south west of Western Australia

    International Nuclear Information System (INIS)

    Walsh, M.; Jennings, P.

    2002-01-01

    Indoor radon and thoron progeny Equilibrium Equivalent Concentrations (EEC) were measured with a portable 'Radon Sniffer' in 10 rammed earth dwellings and 10 conventional dwellings in Margaret River in the South West of Western Australia. Natural background gamma radiation was also measured within the dwellings. The results of this study show that the mean indoor radon progeny concentrations in rammed earth and non-rammed earth dwellings was 24 Bq m -3 EEC and 9.3 Bq m -3 EEC respectively. The mean indoor thoron progeny concentrations in rammed earth and non-rammed earth dwellings was 3.9 Bq m -3 EEC and 0.8 Bq m -3 EEC respectively. The ranges of combined indoor radon and thoron progeny concentrations in rammed earth and non-rammed earth dwellings were between 2.1 and 76 Bq m -3 EEC and 2.0 and 27 Bq m -3 EEC respectively. The mean annual effective radiation dose equivalents from combined indoor radon and thoron progeny concentrations EEC using UNSCEAR's (1982) conversion factors in rammed earth and non-rammed earth dwellings were 4.1 mSv y -1 and 2.2 mSv y -1 respectively. Copyright (2002) Australasian Radiation Protection Society Inc

  17. Recombination-assisted megaprimer (RAM) cloning

    Science.gov (United States)

    Mathieu, Jacques; Alvarez, Emilia; Alvarez, Pedro J.J.

    2014-01-01

    No molecular cloning technique is considered universally reliable, and many suffer from being too laborious, complex, or expensive. Restriction-free cloning is among the simplest, most rapid, and cost-effective methods, but does not always provide successful results. We modified this method to enhance its success rate through the use of exponential amplification coupled with homologous end-joining. This new method, recombination-assisted megaprimer (RAM) cloning, significantly extends the application of restriction-free cloning, and allows efficient vector construction with much less time and effort when restriction-free cloning fails to provide satisfactory results. The following modifications were made to the protocol:•Limited number of PCR cycles for both megaprimer synthesis and the cloning reaction to reduce error propagation.•Elimination of phosphorylation and ligation steps previously reported for cloning methods that used exponential amplification, through the inclusion of a reverse primer in the cloning reaction with a 20 base pair region of homology to the forward primer.•The inclusion of 1 M betaine to enhance both reaction specificity and yield. PMID:26150930

  18. EFFECT FOR A SINGLE ROUGHNESS E=5,63mm OF EXPERIMENTAL TO STUDY HYDRAULIC JUMP PROFILE IN A CHANNEL IN U A ROUGH BOTTOM

    Directory of Open Access Journals (Sweden)

    A. Ghomri

    2013-06-01

    Full Text Available This study aims to study the hydraulic jump controlled by threshold, moving in a channel profile 'U' bottomed rough for a single roughness E=5,63mm. Functional relations in dimensionless terms, linking the different characteristics of the projection, showing the effect of roughness of the bottom of the channel are obtained. The hydraulic jump is the primary means used by hydraulic structures to dissipate energy. This hydraulic jump is formed at the sharp transition from a supercritical flow a stream flow.

  19. EFFECT FOR A SINGLE ROUGHNESS E=5,63mm OF EXPERIMENTAL TO STUDY HYDRAULIC JUMP PROFILE IN A CHANNEL IN U A ROUGH BOTTOM

    Directory of Open Access Journals (Sweden)

    A. Ghomri

    2015-07-01

    Full Text Available This study aims to study the hydraulic jump controlled by threshold, moving in a channel profile 'U' bottomed rough for a single roughness E=5,63mm. Functional relations in dimensionless terms, linking the different characteristics of the projection, showing the effect of roughness of the bottom of the channel are obtained. The hydraulic jump is the primary means used by hydraulic structures to dissipate energy. This hydraulic jump is formed at the sharp transition from a supercritical flow a stream flow.

  20. Information and dialogue process on safety and environmental effects of the hydraulic fracturing technology; Der Informations- und Dialogprozess zur Sicherheit und Umweltvertraeglichkeit der Fracking-Technologie

    Energy Technology Data Exchange (ETDEWEB)

    Borchardt, Dietrich; Richter, Sandra [Helmholtz-Zentrum fuer Umweltforschung - UFZ, Magdeburg (Germany); Ewen, Christoph [team ewen, Darmstadt (Germany); Hammerbacher, Ruth [hammerbacher gmbh - beratung und projekte, Osnabrueck (Germany)

    2012-10-15

    After the big success of hydraulic fracturing in the USA, natural gas utilities are now planning natural gas production from nonconventional deposits (shale gas, coal seam gas) by hydraulic fracturing also in Germany. In order to calm public fears, an 'information and dialogue process on safety and environmental effects of the hydraulic fracturing technology' was initiated. A risk study carried out by a team of neutral experts gives recommendations for a well-founded, careful and realistic discussion of the environmental compatibility of hydraulic fracturing.

  1. Information and dialogue process on safety and environmental effects of the hydraulic fracturing technology; Der Informations- und Dialogprozess zur Sicherheit und Umweltvertraeglichkeit der Fracking-Technologie

    Energy Technology Data Exchange (ETDEWEB)

    Borchardt, Dietrich; Richter, Sandra [Helmholtz-Zentrum fuer Umweltforschung - UFZ, Magdeburg (Germany); Ewen, Christoph [team ewen, Darmstadt (Germany); Hammerbacher, Ruth [hammerbacher gmbh - beratung und projekte, Osnabrueck (Germany)

    2012-10-15

    After the big success of hydraulic fracturing in the USA, natural gas utilities are now planning natural gas production from nonconventional deposits (shale gas, coal seam gas) by hydraulic fracturing also in Germany. In order to calm public fears, an 'information and dialogue process on safety and environmental effects of the hydraulic fracturing technology' was initiated. A risk study carried out by a team of neutral experts gives recommendations for a well-founded, careful and realistic discussion of the environmental compatibility of hydraulic fracturing.

  2. Performance modeling in critical engineering systems using RAM analysis

    International Nuclear Information System (INIS)

    Sharma, Rajiv Kumar; Kumar, Sunand

    2008-01-01

    Reliability, availability and maintainability (RAM) analysis of system is helpful in carrying out design modifications, if any, required to achieve minimum failures or to increase mean time between failures (MTBF) and thus to plan maintainability requirements, optimize reliability and maximize equipment availability. To this effect, the paper presents the application of RAM analysis in a process industry. Markovian approach is used to model the system behavior. For carrying out analysis, transition diagrams for various subsystems are drawn and differential equations associated with them are formulated. After obtaining the steady state solution the corresponding values of reliability and maintainability are estimated at different mission times. The computed results are presented to plant personnel for their active consideration. The results proved helpful to them for analyzing the system behavior and thereby to improve the system performance considerably by adopting and practicing suitable maintenance policies/strategies

  3. Hydraulic Structures

    Data.gov (United States)

    Department of Homeland Security — This table is required whenever hydraulic structures are shown in the flood profile. It is also required if levees are shown on the FIRM, channels containing the...

  4. Computational and experimental study of effects of sediment shape on erosion of hydraulic turbines

    International Nuclear Information System (INIS)

    Poudel, L; Thapa, B; Shrestha, B P; Thapa, B S; Shrestha, K P; Shrestha, N K

    2012-01-01

    Hard particles as Quartz and Feldspar are present in large amount in most of the rivers across the Himalayan basins. In run-off-river hydro power plants these particles find way to turbine and cause its components to erode. Loss of turbine material due to the erosion and subsequent change in flow pattern induce several operational and maintenance problems in the power plants. Reduction in overall efficiency, vibrations and reduced life of turbine components are the major effects of sediment erosion of hydraulic turbines. Sediment erosion of hydraulic turbines is a complex phenomenon and depends upon several factors. One of the most influencing parameter is the characteristics of sediment particles. Quantity of sediment particles, which are harder than the turbine material, is one of the bases to indicate erosion potential of a particular site. Research findings have indicated that shape and size of the hard particles together with velocity of impact play a major role to decide the mode and rate of erosion in turbine components. It is not a common practice in Himalayan basins to conduct a detail study of sediment characteristics as a part of feasibility study for hydropower projects. Lack of scientifically verified procedures and guidelines to conduct the sediment analysis to estimate its erosion potential is one of the reasons to overlook this important part of feasibility study. Present study has been conducted by implementing computational tools to characterize the sediment particles with respect to their shape and size. Experimental studies have also been done to analyze the effects of different combinations of shape and size of hard particles on turbine material. Efforts have also been given to develop standard procedures to conduct similar study to compare erosion potential between different hydropower sites. Digital image processing software and sieve analyzer have been utilized to extract shape and size of sediment particles from the erosion sensitive power

  5. Physical soil properties and slope treatments effects on hydraulic excavator productivity for forest road construction.

    Science.gov (United States)

    Parsakho, Aidin; Hosseini, Seyed Ataollah; Jalilvand, Hamid; Lotfalian, Majid

    2008-06-01

    Effects of moisture, porosity and soil bulk density properties, grubbing time and terrain side slopes on pc 220 komatsu hydraulic excavator productivity were investigated in Miana forests road construction project which located in the northern forest of Iran. Soil moisture and porosity determined by samples were taken from undisturbed soil. The elements of daily works were measured with a digital stop watch and video camera in 14 observations (days). The road length and cross section profiles after each 20 m were selected to estimate earthworks volume. Results showed that the mean production rates for the pc 220 komatsu excavators were 60.13 m3 h(-1) and earthwork 14.76 m h(-1) when the mean depth of excavation or cutting was 4.27 m3 m(-1), respectively. There was no significant effects (p = 0.5288) from the slope classes' treatments on productivity, whereas grubbing time, soil moisture, bulk density and porosity had significantly affected on excavator earthworks volume (p < 0.0001). Clear difference was showed between the earthwork length by slope classes (p = 0.0060). Grubbing time (p = 0.2180), soil moisture (p = 0.1622), bulk density (p = 0.2490) and porosity (p = 0.2159) had no significant effect on the excavator earthworks length.

  6. Effect of pH on saturated hydraulic conductivity and soil dispersion

    Energy Technology Data Exchange (ETDEWEB)

    Suarez, D.L.; Roades, J.D.; Lavado, R.; Grieve, C.M.

    The adverse effects of exchangeable sodium on soil hydraulic conductivity (K) are well known, but at present only sodicity and total electrolyte concentration are used in evaluating irrigation water suitability. In arid areas, high sodicity is often associatd with high dissolved carbonate and thus high pH, but in humid areas high sodicity may be associated with low pH. To evaluate the effect of pH (as an independent variable) on K, solutions with the same SAR and electrolyte level were prepared at pH 6, 7, 8, and 9. Saturated K values were determined at constant flux in columns packed at a bulk density of 1.5 Mg m/sup -3/. At pH 9, saturated K values were lower than at pH 6 for a montmorillonitic and kaolinitic soil. For a vermiculitic soil with lower organic carbon and higher silt content, pH changes did not cause large K differences. Decreases in K were not reversible on application of waters with higher electrolyte levels. The results from the K experiments were generally consistent with optical transmission measurements of dispersion. Although anion adsorption was at or below detection limits and cation exchange capacity (CEC) was only slightly dependent on pH, differences in pH effects on K among soils are likely due to differences in quantities of variable-charge minerals and organic matter.

  7. Simulation Investigation on Application of Powder Metallurgy Damping Effect in Water Hydraulic Pump

    Directory of Open Access Journals (Sweden)

    Shi Weijie

    2018-01-01

    Full Text Available Over the years, the hydrostatic balance slipper is often used to make the hydraulic lubrication film formed between the swash plate and the slipper. In this paper, a slipper containing the powder metallurgy (PM composite material is proposed. The porous characteristics have an automatic damping effect, which can improve the tribological characteristics of the slipper. Based on the Reynolds equation, porous Darcy law and continuity equation, a lubrication model of PM damper is proposed to analyze the damping effect of PM in this paper. The proposed model is calculated using the finite volume method to capture the water film characteristics. Effects of length, diameter and porosity of the PM damper on the water film thickness are investigated. The results show that the water film can be formed by adopting the PM damper. In order to ensure the slipper with PM damper to form hydrostatic support, the length, diameter and porosity of PM damper is recommended to be 5 mm, 8 mm and 0.7, respectively.

  8. Effect of Initial Hydraulic Conditions on Capillary Rise in a Porous Medium: Pore-Network Modeling

    KAUST Repository

    Joekar-Niasar, V.; Hassanizadeh, S. M.

    2012-01-01

    The dynamics of capillary rise in a porous medium have been mostly studied in initially dry systems. As initial saturation and initial hydraulic conditions in many natural and industrial porous media can be variable, it is important to investigate

  9. Effect of wet curing duration on durability parameters of hydraulic cement concretes.

    Science.gov (United States)

    2010-01-01

    Hydraulic cement concrete slabs were cast and stored outdoors in Charlottesville, Virginia, to study the impact of wet curing duration on durability parameters. Concrete mixtures were produced using portland cement, portland cement with slag cement, ...

  10. Investigation of hydraulic fracture re-orientation effects in tight gas reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Hagemann, B.; Wegner, J.; Ganzer, L. [Technische Univ. Clausthal, Clausthal-Zellerfeld (Germany). ITE

    2013-08-01

    In tight gas formations where the low matrix permeability prevents successful and economic production rates, hydraulic fracturing is required to produce a well at economic rates. The initial fracture opens in the direction of minimum stress and propagates into the direction of maximum stress. As production from the well and its initial fracture declines, re-fracturing treatments are required to accelerate recovery. The orientation of the following hydraulic fracture depends on the actual stress-state of the formation in the vicinity of the wellbore. Previous investigations by Elbel and Mack (1993) demonstrated that the stress alters during depletion and a stress reversal region appears. This behavior causes a different fracture orientation of the re-fracturing operation. For the investigation of re-fracture orientation a two-dimensional reservoir model has been designed using COMSOL Multiphysics. The model represents a fractured vertical well in a tight gas reservoir of infinite thickness. A time dependent study was set up to simulate the reservoir depletion by the production from the fractured well. The theory of poroelasticity was used to couple the fluid flow and geo-mechanical behavior. The stress state is initially defined as uniform and the attention is concentrated to the alteration of stress due to the lowered pore pressure. Different cases with anisotropic and heterogeneous permeability are set up to determine its significance. The simulation shows that an elliptical shaped drainage area appears around the fracture. The poroelastic behavior effects that the stress re-orientates and a stress reversal region originates, if the difference between minimum and maximum horizontal stresses is small. The consideration of time indicates that the dimension of the region initially extends fast until it reaches its maximum. Subsequently, the stress reversal region's extent shrinks slowly until it finally disappears. The reservoir characteristics, e.g. the

  11. Effect of persistent high intraocular pressure on microstructure and hydraulic permeability of trabecular meshwork

    International Nuclear Information System (INIS)

    Mei Xi; Ren Lin; Xu Qiang; Liu Zhi-Cheng; Zheng Wei

    2015-01-01

    As the aqueous humor leaves the eye, it first passes through the trabecular meshwork (TM). Increased flow resistance in this region causes elevation of intraocular pressure (IOP), which leads to the occurrence of glaucoma. To quantitatively evaluate the effect of high IOP on the configuration and hydraulic permeability of the TM, second harmonic generation (SHG) microscopy was used to image the microstructures of the TM and adjacent tissues in control (normal) and high IOP conditions. Enucleated rabbit eyes were perfused at a pressure of 60 mmHg to achieve the high IOP. Through the anterior chamber of the eye, in situ images were obtained from different depths beneath the surface of the TM. Porosity and specific surface area of the TM in control and high IOP conditions were then calculated to estimate the effect of the high pressure on the permeability of tissue in different depths. We further photographed the histological sections of the TM and compared the in situ images. The following results were obtained in the control condition, where the region of depth was less than 55 μm with crossed branching beams and large pores in the superficial TM. The deeper meshwork is a silk-like tissue with abundant fluorescence separating the small size of pores. The total thickness of pathway tissues composed of TM and juxtacanalicular (JCT) is more than 100 μm. After putting a high pressure on the inner wall of the eye, the TM region progressively collapses and decreases to be less than 40 μm. Fibers of the TM became dense, and the porosity at 34 μm in the high IOP condition is comparable to that at 105 μm in the control condition. As a consequent result, the permeability of the superficial TM decreases rapidly from 120 μm 2 to 49.6 μm 2 and that of deeper TM decreases from 1.66 μm 2 to 0.57 μm 2 . Heterogeneity reflected by descent in permeability reduces from 12.4 μm of the control condition to 3.74 μm of the high IOP condition. The persistently high IOP makes the

  12. Hydraulic Simulation of In-vessel Downstream Effect Test Using MARS-KS Code

    Energy Technology Data Exchange (ETDEWEB)

    Bang, Young Seok; Lee, Joon Soo; Ryu, Seung Hoon [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of)

    2015-05-15

    In-vessel downstream effect test (IDET) has been required to evaluate the effect of debris on long term core cooling following a loss of coolant accident (LOCA) in support of resolution of Generic Safety Issue (GSI) 191. Head loss induced by debris (fiber and particle) accumulated on prototypical fuel assembly (FA) should be compared with the available driving head to the core for the various combinations of LOCA and Emergency Core Cooling System (ECCS) injection. The actual simulation was conducted using MARS-KS code. Also the influence of small difference in gap size which was found in the actual experiment is evaluated using the present model. A simple model to determine the form loss factors of FA and gap in clean state and the debris laden state is discussed based on basic fluid mechanics. Those form loss factors were applied to the hydraulic simulation of a selected IDET using MARS-KS code. The result indicated that the present model can be applied to IDET simulation. The pressure drop influenced by small difference in gap size can be evaluated by the present model with practical assumption.

  13. Convergence of the effect of root hydraulic functioning and root hydraulic redistribution on ecosystem water and carbon balance across divergent forest ecosystems

    Science.gov (United States)

    domec, J.; King, J. S.; Ogée, J.; Noormets, A.; Warren, J.; Meinzer, F. C.; Sun, G.; Jordan-Meille, L.; Martineau, E.; Brooks, R. J.; Laclau, J.; Battie Laclau, P.; McNulty, S.

    2012-12-01

    INVITED ABSTRACT: Deep root water uptake and hydraulic redistribution (HR) play a major role in forest ecosystems during drought, but little is known about the impact of climate change on root-zone processes influencing HR and its consequences on water and carbon fluxes. Using data from two old growth sites in the western USA, two mature sites in the eastern USA, one site in southern Brazil, and simulations with the process-based model MuSICA, our objectives were to show that HR can 1) mitigate the effects of soil drying on root functioning, and 2) have important implications for carbon uptake and net ecosystem exchange (NEE). In a dry, old-growth ponderosa pine (USA) and a eucalyptus stand (Brazil) both characterized by deep sandy soils, HR limited the decline in root hydraulic conductivity and increased dry season tree transpiration (T) by up to 30%, which impacted NEE through major increases in gross primary productivity (GPP). The presence of deep-rooted trees did not necessarily imply high rates of HR unless soil texture allowed large water potential gradients to occur, as was the case in the wet old-growth Douglas-fir/mixed conifer stand. At the Duke mixed hardwood forest characterized by a shallow clay-loam soil, modeled HR was low but not negligible, representing annually up to 10% of T, and maintaining root conductance high. At this site, in the absence of HR, it was predicted that annual GPP would have been diminished by 7-19%. At the coastal loblolly pine plantation, characterized by deep organic soil, HR limited the decline in shallow root conductivity by more than 50% and increased dry season T by up to 40%, which increased net carbon gain by the ecosystem by about 400 gC m-2 yr-1, demonstrating the significance of HR in maintaining the stomatal conductance and assimilation capacity of the whole ecosystem. Under future climate conditions (elevated atmospheric [CO2] and temperature), HR is predicted to be reduced by up to 50%; reducing the resilience of

  14. Effect of pore structure on chemico-osmotic, diffusion and hydraulic properties of mud-stones

    International Nuclear Information System (INIS)

    Takeda, M.; Manaka, M.; Ito, K.; Miyoshi, S.; Tokunaga, T.

    2012-01-01

    Formations in the Horonobe research area of Japan, where the Japan Atomic Energy Agency (JAEA) has been operating an Underground Research Laboratory. The rock samples are of cylindrical shape with 50 mm in diameter and 10 mm in length. The rock samples were immersed in 0.1 M NaCl solutions before experiments. The densities, specific surface area and cation exchange capacity were measured for the remains of drill cores from which the samples were taken. Pore radius distribution, average pore radius and porosity were also evaluated for each drill cores by mercury porosimetry. The permeability and chemical-osmosis experiments were performed in sequence on each rock sample under the confining pressures simulating in-situ effective stress condition. 0.1 M NaCl solution was used as permeant fluid in the permeability experiment, and the same solution was used as initial solution in the subsequent chemical-osmosis experiment. In the permeability experiment, a constant pressure was applied to the upper surface of rock sample. In the chemical-osmosis experiment, the bottom reservoir solution was replaced with 0.6 M NaCl solution. Both experiments were performed with the bottom reservoir isolated from the pressure buffer tank, and the progress of each experiment was monitored by measuring the bottom reservoir pressure. Figure 2 shows the chemico-osmotic, diffusion and hydraulic parameters determined for the Koetoi and Wakkanai mud-stone samples as functions of porosity. The diffusion and hydraulic parameters of these samples generally decrease with the decrease of porosity, while the osmotic efficiency is not a simple function of porosity. A relatively large osmotic efficiency was obtained only from a Wakkanai mud-stone sample with porosity of 0.33. The Wakkanai mud-stone samples have similar average pore radius, ranging from 6.8 to 7.6 nm; however, the Wakkanai mud-stone samples without large osmotic efficiency have bimodal pore structures. These suggest that even if small size pores

  15. Baseflow recession analysis in a large shale play: Climate variability and anthropogenic alterations mask effects of hydraulic fracturing

    Science.gov (United States)

    Arciniega-Esparza, Saúl; Breña-Naranjo, Jose Agustín; Hernández-Espriú, Antonio; Pedrozo-Acuña, Adrián; Scanlon, Bridget R.; Nicot, Jean Philippe; Young, Michael H.; Wolaver, Brad D.; Alcocer-Yamanaka, Victor Hugo

    2017-10-01

    Water resources development and landscape alteration exert marked impacts on water-cycle dynamics, including areas subjected to hydraulic fracturing (HF) for exploitation of unconventional oil and gas resources found in shale or tight sandstones. Here we apply a conceptual framework for linking baseflow analysis to changes in water demands from different sectors (e.g. oil/gas extraction, irrigation, and municipal consumption) and climatic variability in the semiarid Eagle Ford play in Texas, USA. We hypothesize that, in water-limited regions, baseflow (Qb) changes are partly due (along with climate variability) to groundwater abstraction. For a more realistic assessment, the analysis was conducted in two different sets of unregulated catchments, located outside and inside the Eagle Ford play. Three periods were considered in the analysis related to HF activities: pre-development (1980-2000), moderate (2001-2008) and intensive (2009-2015) periods. Results indicate that in the Eagle Ford play region, temporal changes in baseflow cannot be directly related to the increase in hydraulic fracturing. Instead, substantial baseflow declines during the intensive period of hydraulic fracturing represent the aggregated effects from the combination of: (1) a historical exceptional drought during 2011-2012; (2) increased groundwater-based irrigation; and (3) an intensive hydraulic fracturing activity.

  16. Thermo hydraulic analysis of narrow channel effect in supercritical-pressure light water reactor

    International Nuclear Information System (INIS)

    Zhou Tao; Chen Juan; Cheng Wanxu

    2012-01-01

    Highlights: ► Detailed thermal analysis with different narrow gaps between fuel rods is given. ► Special characteristics of narrow channels effect on heat transfer in supercritical pressure are shown. ► Reasonable size selection of gaps between fuel rods is proposed for SCWR. - Abstract: The size of the gap between fuel rods has important effects on flow and heat transfer in a supercritical-pressure light water reactor. Based on thermal analysis at different coolant flow rates, the reasonable value range of gap size between fuel rods is obtained, for which the maximum cladding temperature safety limits and installation technology are comprehensively considered. Firstly, for a given design flow rate of coolant, thermal hydraulic analysis of supercritical pressure light water reactor with different gap sizes is provided by changing the fuel rod pitch only. The results show that, by means of reducing the gap size between fuel rods, the heat transfer coefficients between coolant and fuel rod, as well as the heat transfer coefficient between coolant and water rod, would both increase noticeably. Furthermore, the maximum cladding temperature will significantly decrease when the moderator temperature is decreased but coolant temperature remains essentially constant. Meanwhile, the reduction in the maximum cladding temperature in the inner assemblies is much larger than that in the outer assemblies. In addition, the maximum cladding temperature could be further reduced by means of increasing coolant flow rate for each gap size. Finally, the characteristics of narrow channels effect are proposed, and the maximum allowable gap between fuel rods is obtained by making full use of the enhancing narrow channels effect on heat transfer, and concurrently considering installation. This could provide a theoretical reference for supercritical-pressure light water reactor design optimization, in which the effects of gap size and flow rate on heat transfer are both considered.

  17. Effects of non-linearity of material properties on the coupled mechanical-hydraulic-thermal behavior in rock mass

    International Nuclear Information System (INIS)

    Kobayashi, Akira; Ohnishi, Yuzo

    1986-01-01

    The nonlinearity of material properties used in the coupled mechanical-hydraulic-thermal analysis is investigated from the past literatures. Some nonlinearity that is respectively effective for the system is introduced into our computer code for analysis such a coupling problem by using finite element method. And the effects of nonlinearity of each material property on the coupled behavior in rock mass are examined for simple model and Stripa project model with the computer code. (author)

  18. Using Oblivious RAM in Genomic Studies

    NARCIS (Netherlands)

    Karvelas, Nikolaos P.; Peter, Andreas; Katzenbeisser, Stefan; Garcia-Alfaro, Joaquin; Navarro-Aribas, Guillermo; Hartenstein, Hannes; Herrera-Joancomarti, Jordi

    2017-01-01

    Since the development of tree-based Oblivious RAMs by Shi et al. it has become apparent that privacy preserving outsourced storage can be practical. Although most current constructions follow a client-server model, in many applications, such as Genome Wide Association Studies (GWAS), it is desirable

  19. National RAM transport regulations implementation in Russia

    International Nuclear Information System (INIS)

    Gubanov, V.A.

    1995-01-01

    A brief review is given of the main provisions of the state regulation and safety assurance of RAM transport in Russia. This appears to be useful to various persons and organisations abroad, concerned with such transport in Russia. Two aspects of the system are presented - regulatory documents (normative-technical documentation) and regulatory and control activities of state organisations. (Author)

  20. Rumenolith formation in a Bapedi ram

    Directory of Open Access Journals (Sweden)

    Rhoda Leask

    2012-04-01

    Full Text Available During a routine flock visit, a farmer observed that one of the eight tooth Bapedi rams had been losing body condition despite being separated from the flock and fed supplementary feed. The ram’s body condition score was assessed as 2 out of 5 (one point less than the average of the rest of the rams and the teeth appeared normal with no excessive wear. The rumen was assessed by auscultation, palpation and ballottement where a foreign body (approximately 20 cm × 5 cm – 10 cm was clearly palpated and ballotted. A rumenotomy was performed and a large mass of tightly compacted foreign matter and plant material was removed. The mass consisted of synthetic fibre, plant material and calcium phosphate (50.5%. It appeared to have formed as the result of the ingestion of a synthetic fibre which formed the nidus of a concretion. This was probably the result of deficient nutrition, with the rams eating the synthetic fibre in an attempt to increase feed intake. The ram recovered uneventfully after the rumenotomy was performed and supplementary feeding.

  1. Perfectly Secure Oblivious RAM without Random Oracles

    DEFF Research Database (Denmark)

    Damgård, Ivan Bjerre; Meldgaard, Sigurd Torkel; Nielsen, Jesper Buus

    2011-01-01

    We present an algorithm for implementing a secure oblivious RAM where the access pattern is perfectly hidden in the information theoretic sense, without assuming that the CPU has access to a random oracle. In addition we prove a lower bound on the amount of randomness needed for implementing...

  2. Effect of hydraulic retention time on metal precipitation in sulfate reducing inverse fluidized bed reactors

    KAUST Repository

    Villa-Gómez, Denys Kristalia

    2014-02-13

    BACKGROUND: Metal sulfide recovery in sulfate reducing bioreactors is a challenge due to the formation of small precipitates with poor settling properties. The size of the metal sulfide precipitates with the change in operational parameters such as pH, sulfide concentration and reactor configuration has been previously studied. The effect of the hydraulic retention time (HRT) on the metal precipitate characteristics such as particle size for settling has not yet been addressed. RESULTS: The change in size of the metal (Cu, Zn, Pb and Cd) sulfide precipitates as a function of the HRT was studied in two sulfate reducing inversed fluidized bed (IFB) reactors operating at different chemical oxygen demand concentrations to produce high and low sulfide concentrations. The decrease of the HRT from 24 to 9h in both IFB reactors affected the contact time of the precipitates formed, thus making differences in aggregation and particle growth regardless of the differences in sulfide concentration. Further HRT decrease to 4.5h affected the sulfate reducing activity for sulfide production and hence, the supersaturation level and solid phase speciation. Metal sulfide precipitates affected the sulfate reducing activity and community in the biofilm, probably because of the stronger local supersaturation causing metal sulfides accumulation in the biofilm. CONCLUSIONS: This study shows that the HRT is an important factor determining the size and thus the settling rate of the metal sulfides formed in bioreactors.

  3. Effect of Providing Information on Students' Knowledge and Concerns about Hydraulic Fracking.

    Science.gov (United States)

    Burger, Joanna; Nakata, Kimi; Liang, Laura; Pittfield, Taryn; Jeitner, Christian

    2015-01-01

    Governmental agencies, regulators, health professionals, and the public are faced with understanding and responding to new development practices and conditions in their local and regional environment. While hydraulic fracking (fracking) for shale gas has been practiced for over 50 years in some states, it is a relatively recent event in the northeastern United States. Providing environmental health information to the public about fracking requires understanding both the knowledge base and the perceptions of the public. The knowledge, perceptions, and concerns of college students about fracking were examined. Students were interviewed at Rutgers University in New Jersey, a state without any fracking, although fracking occurs in nearby Pennsylvania. Objectives were to determine (1) knowledge about fracking, (2) rating of concerns, (3) trusted information sources, (4) importance of fracking relative to other energy sources, and (5) the effect of a 15-min lecture and discussion on these aspects. On the second survey, students improved on their knowledge (except the components used for fracking), and their ratings changed for some concerns, perceived benefits, and trusted information sources. There was no change in support for further development of natural gas, but support for solar, wind, and wave energy decreased. Data suggest that students' knowledge and perceptions change with exposure to information, but many of these changes were due to students using the Internet to look up information immediately after the initial survey and lecture. Class discussions indicated a general lack of trust for several information sources available on the Web.

  4. EFFECT OF PROVIDING INFORMATION ON STUDENTS’ KNOWLEDGE AND CONCERNS ABOUT HYDRAULIC FRACKING

    Science.gov (United States)

    Burger, Joanna; Nakata, Kimi; Liang, Laura; Pittfield, Taryn; Jeitner, Christian

    2015-01-01

    Governmental agencies, regulators, health professionals, and the public are faced with understanding and responding to new development practices and conditions in their local and regional environment. While hydraulic fracking (fracking) for shale gas has been practiced for over 50 years in some states, it is a relatively recent event in the northeastern United States. Providing environmental health information to the public about fracking requires understanding both the knowledge base and the perceptions of the public. The knowledge, perceptions, and concerns of college students about fracking were examined. Students were interviewed at Rutgers University in New Jersey, a state without any fracking, although fracking occurs in nearby Pennsylvania. Objectives were to determine (1) knowledge about fracking, (2) rating of concerns, (3) trusted information sources, (4) importance of fracking relative to other energy sources, and (5) the effect of a 15-min lecture and discussion on these aspects. On the second survey, students improved on their knowledge (except the components used for fracking), and their ratings changed for some concerns, perceived benefits, and trusted information sources. There was no change in support for further development of natural gas, but support for solar, wind, and wave energy decreased. Data suggest that students’ knowledge and perceptions change with exposure to information, but many of these changes were due to students using the Internet to look up information immediately after the initial survey and lecture. Class discussions indicated a general lack of trust for several information sources available on the Web. PMID:25965194

  5. The coupled effect of fiber volume fraction and void fraction on hydraulic fluid absorption of quartz/BMI laminates

    Science.gov (United States)

    Hurdelbrink, Keith R.; Anderson, Jacob P.; Siddique, Zahed; Altan, M. Cengiz

    2016-03-01

    Bismaleimide (BMI) resin with quartz (AQ581) fiber reinforcement is a composite material frequently used in aerospace applications, such as engine cowlings and radomes. Various composite components used in aircrafts are exposed to different types of hydraulic fluids, which may lead to anomalous absorption behavior over the service life of the composite. Accurate predictive models for absorption of liquid penetrants are particularly important as the composite components are often exposed to long-term degradation due to absorbed moisture, hydraulic fluids, or similar liquid penetrants. Microstructural features such as fiber volume fraction and void fraction can have a significant effect on the absorption behavior of fiber-reinforced composites. In this paper, hydraulic fluid absorption characteristics of quartz/BMI laminates fabricated from prepregs preconditioned at different relative humidity and subsequently cured at different pressures are presented. The composite samples are immersed into hydraulic fluid at room temperature, and were not subjected to any prior degradation. To generate process-induced microvoids, prepregs were conditioned in an environmental chamber at 2% or 99% relative humidity at room temperature for a period of 24 hours prior to laminate fabrication. To alter the fiber volume fraction, the laminates were fabricated at cure pressures of 68.9 kPa (10 psi) or 482.6 kPa (70 psi) via a hot-press. The laminates are shown to have different levels of microvoids and fiber volume fractions, which were observed to affect the absorption dynamics considerably and exhibited clear non-Fickian behavior. A one-dimensional hindered diffusion model (HDM) was shown to be successful in predicting the hydraulic fluid absorption. Model prediction indicates that as the fabrication pressure increased from 68.9 kPa to 482.6 kPa, the maximum fluid content (M∞) decreased from 8.0% wt. to 1.0% wt. The degree of non-Fickian behavior, measured by hindrance coefficient (

  6. Micro-hydromechanical deep drawing of metal cups with hydraulic pressure effects

    Science.gov (United States)

    Luo, Liang; Jiang, Zhengyi; Wei, Dongbin; Wang, Xiaogang; Zhou, Cunlong; Huang, Qingxue

    2018-03-01

    Micro-metal products have recently enjoyed high demand. In addition, metal microforming has drawn increasing attention due to its net-forming capability, batch manufacturing potential, high product quality, and relatively low equipment cost. Micro-hydromechanical deep drawing (MHDD), a typical microforming method, has been developed to take advantage of hydraulic force. With reduced dimensions, the hydraulic pressure development changes; accordingly, the lubrication condition changes from the macroscale to the microscale. A Voronoi-based finite element model is proposed in this paper to consider the change in lubrication in MHDD according to open and closed lubricant pocket theory. Simulation results agree with experimental results concerning drawing force. Changes in friction significantly affect the drawing process and the drawn cups. Moreover, defined wrinkle indexes have been shown to have a complex relationship with hydraulic pressure. High hydraulic pressure can increase the maximum drawing ratio (drawn cup height), whereas the surface finish represented by the wear is not linearly dependent on the hydraulic pressure due to the wrinkles.

  7. High Bulk Modulus of Ionic Liquid and Effects on Performance of Hydraulic System

    Directory of Open Access Journals (Sweden)

    Milan Kambic

    2014-01-01

    Full Text Available Over recent years ionic liquids have gained in importance, causing a growing number of scientists and engineers to investigate possible applications for these liquids because of their unique physical and chemical properties. Their outstanding advantages such as nonflammable liquid within a broad liquid range, high thermal, mechanical, and chemical stabilities, low solubility for gases, attractive tribological properties (lubrication, and very low compressibility, and so forth, make them more interesting for applications in mechanical engineering, offering great potential for new innovative processes, and also as a novel hydraulic fluid. This paper focuses on the outstanding compressibility properties of ionic liquid EMIM-EtSO4, a very important physical chemically property when IL is used as a hydraulic fluid. This very low compressibility (respectively, very high Bulk modulus, compared to the classical hydraulic mineral oils or the non-flammable HFDU type of hydraulic fluids, opens up new possibilities regarding its usage within hydraulic systems with increased dynamics, respectively, systems’ dynamic responses.

  8. Semen Characteristics of the West African Dwarf Rams in The ...

    African Journals Online (AJOL)

    WAD) rams in Makurdi. Semen samples were collected from five rams twice a week by electroejaculation method over a period of two months (September to October). The ejaculate volume, concentration, mass activity, progressive motility, the ...

  9. Phenomenology and thermo-hydraulic stability of the CAREM-25 reactor: Evaluation of subcooled boiling effect

    International Nuclear Information System (INIS)

    Acuna, F.M.; Marcel, C.P.; Zanocco, P.G.; Delmastro, D.F.

    2012-01-01

    In this article the phenomenology present in self/pressurized, integral, natural circulation, low thermodynamic quality nuclear reactors similar to CAREM-25 is investigated. In particular, analytical relations for the mass flow rate, the core mean enthalpy and the location of the two phase boundary are derived in terms of the so-called natural variables of the system: the nuclear power, the condensation power and the system pressure. In addition, some consequences of the flashing phenomenon in the reactor thermal-hydraulics are discussed emphasizing those affecting the reactor stability. The reactor stability performance was studied by using the HUARPE code which is a low diffusive code. The stability results obtained by neglecting the subcooled effect in the system are presented in the so-called the stability maps in which the results are presented for a wide range of conditions. The stability effect caused by the presence of subcooled boiling in the reactor core was also examined. In order to investigate such a consequence, the code was slightly modified such that the predicted vapor profile in the hot leg is similar to that estimated by RELAP system code at steady state conditions. The simple implemented algorithm allows varying a free parameter with which a broad number of cases can be studied. This is important since the subcooled boiling predictions generally have large uncertainties and therefore to cover a large number of situations is desired to derive confident conclusions. The results show the existence of vapor created by means of subcooled boiling enhances the system stability for a wide range of conditions. For this reason from this preliminary investigation, it is concluded neglecting the subcooled effect in CAREM-25 stability studies is a conservative criterion (author))

  10. Alpha particle induced soft errors in NMOS RAMs: a review

    International Nuclear Information System (INIS)

    Carter, P.M.; Wilkins, B.R.

    1987-01-01

    The paper aims to explain the alpha particle induced soft error phenomenon using the NMOS dynamic random access memory (RAM) as a model. It discusses some of the many techniques experimented with by manufacturers to overcome the problem, and gives a review of the literature covering most aspects of soft errors in dynamic RAMs. Finally, the soft error performance of current dynamic RAM and static RAM products from several manufacturers are compared. (author)

  11. Effect of Contamination on the Lifetime of Hydraulic Oils and Systems

    Directory of Open Access Journals (Sweden)

    Marián Kučera

    2017-01-01

    Full Text Available The extensions of service‑lives regarding hydraulic fluids is gaining prominence due to several considerations including environmental pollution, conservation of natural resources and the economic benefits associated with extended service‑life. The presented methods for testing the durability and oxidation stabilities of hydraulic fluids can be simultaneously used in two ways. Firstly for comparing different hydraulic biooils and for selecting more adequate oils with higher oxidation stabilities and longer service lifetimes and secondly for the development of a prognostic model for an accurate prediction of an oil’s condition and its remaining useful lifetime, which could help to extend the service life of the oil without concerns about damaging the equipment.

  12. RELAP5 model to simulate the thermal-hydraulic effects of grid spacers and cladding rupture during reflood

    Energy Technology Data Exchange (ETDEWEB)

    Nithianandan, C.K.; Klingenfus, J.A.; Reilly, S.S. [B& W Nuclear Technologies, Lynchburg, VA (United States)

    1995-09-01

    Droplet breakup at spacer grids and a cladding swelled and ruptured locations plays an important role in the cooling of nuclear fuel rods during the reflooding period of a loss-of-coolant accident (LOCA) in a pressurized water reactor (PWR). During the reflood phase, a spacer grid affects the thermal-hydraulic system behavior through increased turbulence, droplet breakup due to impact on grid straps, grid rewetting, and liquid holdup due to grid form losses. Recently, models to simulate spacer grid effects and blockage and rupture effects on system thermal hydraulics were added to the B&W Nuclear Technologies (BWNT) version of the RELAP5/MOD2 computer code. Several FLECHT-SEASET forced reflood tests, CCTF Tests C1-19 and C2-6, SCTF Test S3-15, and G2 Test 561 were simulated using RELAP5/MOD2-B&W to verify the applicability of the model at the cladding swelled and rupture locations. The results demonstrate the importance of modeling the thermal-hydraulic effects due to grids, and clad swelling and rupture to correctly predict the clad temperature response during the reflood phase of large break LOCA. The RELAP5 models and the test results are described in this paper.

  13. Effect of AlN layer on the bipolar resistive switching behavior in TiN thin film based ReRAM device for non-volatile memory application

    Science.gov (United States)

    Prakash, Ravi; Kaur, Davinder

    2018-05-01

    The effect of an additional AlN layer in the Cu/TiN/AlN/Pt stack configuration deposited using sputtering has been investigated. The Cu/TiN/AlN/Pt device shows a tristate resistive switching. Multilevel switching is facilitated by ionic and metallic filament formation, and the nature of the filaments formed is confirmed by performing a resistance vs. temperature measurement. Ohmic behaviour and trap controlled space charge limited current (SCLC) conduction mechanisms are confirmed as dominant conduction mechanism at low resistance state (LRS) and high resistance state (HRS). High resistance ratio (102) corresponding to HRS and LRS, good write/erase endurance (105) and non-volatile long retention (105s) are also observed. Higher thermal conductivity of the AlN layer is the main reasons for the enhancement of resistive switching performance in Cu/TiN/AlN/Pt cell. The above result suggests the feasibility of Cu/TiN/AlN/Pt devices for multilevel nonvolatile ReRAM application.

  14. Effects of variations in hydraulic conductivity and flow conditions on groundwater flow and solute transport in peatlands

    Energy Technology Data Exchange (ETDEWEB)

    Kellner, Erik [Dept. of Forest Ecology, Univ. of Helsinki (Finland)

    2007-02-15

    In this report it is examined to what extent the variation in hydraulic conductivity within a peatland and adjoining sediments would affect the flow patterns within it under some certain hydraulic-head gradients and other certain border conditions. The first part of the report contains a short review of organic and mineral-soil sediment types and characteristics and what we know about present peatlands and underlying sediments in the SKB investigation areas today. In the next part, a 2-dimensional model is used to simulate flows and transports in different settings of a peatland, with the objective of studying the effects of some particular factors: 1. The magnitude of the hydraulic conductivity of the peat and of underlying layers. 2. Presence and positions of cracks in underlying clay layers. 3. Anisotropy and heterogeneity in peat hydraulic conductivity. 4. The size of the water recharge at the peatland surface. 5. The seasonal variation of the water recharge. The modelling results show that the importance of flow direction decreases with decreasing hydraulic conductivity in the peatland. This occurs as the convective flux is slowed down and the transport is taken over by the diffusive flux. Because the lowest hydraulic conductivity layer to large extent determines the size of the flow, presence of a low-conductivity layer, such as a layer of clay, is an important factor. Presence of cracks in such tight layers can increase the transport of solutes into the peat. The highest inflow rates are reached when such cracks occur in discharge areas with strong upward flow. On the other hand, a conservative solute can spread efficiently if there is a crack in low-flow locations. The effect of anisotropy is found to be small, partly because the horizontal gradients become smaller as distances are larger. The effect of layers with high or low permeability varies depending on the location and the prevailing gradients. One tight layer has a strong effect on the flow pattern

  15. Effects of variations in hydraulic conductivity and flow conditions on groundwater flow and solute transport in peatlands

    International Nuclear Information System (INIS)

    Kellner, Erik

    2007-02-01

    In this report it is examined to what extent the variation in hydraulic conductivity within a peatland and adjoining sediments would affect the flow patterns within it under some certain hydraulic-head gradients and other certain border conditions. The first part of the report contains a short review of organic and mineral-soil sediment types and characteristics and what we know about present peatlands and underlying sediments in the SKB investigation areas today. In the next part, a 2-dimensional model is used to simulate flows and transports in different settings of a peatland, with the objective of studying the effects of some particular factors: 1. The magnitude of the hydraulic conductivity of the peat and of underlying layers. 2. Presence and positions of cracks in underlying clay layers. 3. Anisotropy and heterogeneity in peat hydraulic conductivity. 4. The size of the water recharge at the peatland surface. 5. The seasonal variation of the water recharge. The modelling results show that the importance of flow direction decreases with decreasing hydraulic conductivity in the peatland. This occurs as the convective flux is slowed down and the transport is taken over by the diffusive flux. Because the lowest hydraulic conductivity layer to large extent determines the size of the flow, presence of a low-conductivity layer, such as a layer of clay, is an important factor. Presence of cracks in such tight layers can increase the transport of solutes into the peat. The highest inflow rates are reached when such cracks occur in discharge areas with strong upward flow. On the other hand, a conservative solute can spread efficiently if there is a crack in low-flow locations. The effect of anisotropy is found to be small, partly because the horizontal gradients become smaller as distances are larger. The effect of layers with high or low permeability varies depending on the location and the prevailing gradients. One tight layer has a strong effect on the flow pattern

  16. How to effectively compute the reliability of a thermal-hydraulic nuclear passive system

    International Nuclear Information System (INIS)

    Zio, E.; Pedroni, N.

    2011-01-01

    Research highlights: → Optimized LS is the preferred choice for failure probability estimation. → Two alternative options are suggested for uncertainty and sensitivity analyses. → SS for simulation codes requiring seconds or minutes to run. → Regression models (e.g., ANNs) for simulation codes requiring hours or days to run. - Abstract: The computation of the reliability of a thermal-hydraulic (T-H) passive system of a nuclear power plant can be obtained by (i) Monte Carlo (MC) sampling the uncertainties of the system model and parameters, (ii) computing, for each sample, the system response by a mechanistic T-H code and (iii) comparing the system response with pre-established safety thresholds, which define the success or failure of the safety function. The computational effort involved can be prohibitive because of the large number of (typically long) T-H code simulations that must be performed (one for each sample) for the statistical estimation of the probability of success or failure. The objective of this work is to provide operative guidelines to effectively handle the computation of the reliability of a nuclear passive system. Two directions of computation efficiency are considered: from one side, efficient Monte Carlo Simulation (MCS) techniques are indicated as a means to performing robust estimations with a limited number of samples: in particular, the Subset Simulation (SS) and Line Sampling (LS) methods are identified as most valuable; from the other side, fast-running, surrogate regression models (also called response surfaces or meta-models) are indicated as a valid replacement of the long-running T-H model codes: in particular, the use of bootstrapped Artificial Neural Networks (ANNs) is shown to have interesting potentials, including for uncertainty propagation. The recommendations drawn are supported by the results obtained in an illustrative application of literature.

  17. Effects of Salt Accumulation in Soil by Evaporation on Unsaturated Soil Hydraulic Properties

    Science.gov (United States)

    Liu, Y.; Liu, Q.

    2017-12-01

    Soil salinization is one type of soil degradation caused by saline groundwater evaporation. Salt accumulation in the soil will change the pore structure of soil, which should change the unsaturated soil hydraulic properties including the soil water characteristic curve (SWCC). To investigate the effect of salt accumulation on the SWCC and find the best suitable SWCC model to characterize the relationship of soil moisture and soil matrix potential, we have conducted laboratory SWCC experiments with the soil columns saturated by NaCl solution with different concentration (deionized water, 3 g/L, 15 g/L, 50 g/L, 100 g/L and 200 g/L). As the concentration of initial solution increases, the matrix potential corresponding to the same moisture increases. As the water was evaporated, the salt would precipitate in soil continuously, which would decrease the porosity of soils and increase the negative pressure of soils. With higher initial concentration, the more salt accumulation caused the more residual water content in the soils. For van Genuchten-Mualem model, the residual water contents θr were 0.0159, 0.0181, 0.0182, 0.0328, 0.0312, 0.0723, 0.0864 in the columns initially saturated by deionized water, 3 g/L, 15 g/L, 50 g/L, 100 g/L and 200 g/L, respectively. The van Genuchten-Mualem model, Fredlund-Xing model, Gardern model, Mckee-Bumb model and Brooks-Corey model were fitted by MATLAB with the experiments data, and the fitted coefficients were compared. The Fredlund-Xing model has the best fitting coefficients and the calculated value was consistent with the observed data.

  18. Temperature effect on the poro-mechanical or hydraulic behaviour of a carbonated rock and a mortar: experimental studies

    International Nuclear Information System (INIS)

    Lion, M.

    2004-07-01

    The main objective of this study is to evaluate the temperature effect on the hydraulic and poro-mechanical behaviour of a limestone. Many experimental tests (porosity and permeability measurements, uniaxial and hydrostatic compressions tests) were carried out in order to study the thermal treatments effect and so the thermal microcracking effect on rock behaviour. Moreover, an experimental device for permeability measurements under high temperatures (until 200 C) was realized. This experimental device permitted to study the permeability variation of the limestone under thermal stresses. Finally, the behaviour of cementitious materials was studied; the temperature effect on the permeability of a mortar was examined. (author)

  19. PWR blowdown heat transfer separate-effects program: Thermal-Hydraulic Test Facility experimental data report for test 100

    International Nuclear Information System (INIS)

    White, M.D.; Hedrick, R.A.

    1977-01-01

    Reduced instrument responses are presented for Thermal-Hydraulic Test Facility (THTF) test 100, which is part of the ORNL Pressurized-Water-Reactor (PWR) Blowdown Heat Transfer Separate-Effects Program. The objective of the program is to investigate the thermal-hydraulic phenomenon governing the energy transfer and transport processes that occur during a loss-of-coolant accident in a PWR system. Test 100 was conducted to investigate the response of heater rod bundle 1 and instrumented spool pieces with flow homogenizing screens to a double-ended rupture with equal break areas at the test section inlet and outlet. The primary purpose of this report is to make the reduced instrument responses during test 100 available. The responses are presented in graphical form in engineering units and have been analyzed only to the extent necessary to assure reasonableness and consistency

  20. Effects of the friction coefficient on the torque characteristics of a hydraulic cam-rotor vane motor

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Qiankun; Wang, Xuyong; Yuan, Fan; Chen, Liang Shen; Tao, Jian Feng [School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai (China); Miao, Zhong Hua [School of Mechatronic Engineering and Automation, Shanghai University, Shanghai (China)

    2016-08-15

    The friction coefficient between the vane and the slot is one of the most critical factors that affects the performance of a continuous rotary hydraulic cam-rotor vane motor. To study the effects of this coefficient on the torque characteristics of the motor, the mathematical model for the normal force and the disturbing torque between the cam rotors and the vanes of the motor was established by analyzing the forces exerted on the vanes. The mathematical model was simulated with MATLAB, and simulation results show that an increase in the friction coefficient would simultaneously decrease the normal force and increase the disturbing torque, which would negatively affect the performance of the motor. Further experimental research indicated that the low-speed performance of the hydraulic cam-rotor motor was significantly improved when the friction coefficient was reduced by controlling the parallelism tolerance, flatness and roughness between the vanes and the slots.

  1. Effective soil hydraulic properties in space and time: some field data analysis and modeling concepts

    Science.gov (United States)

    Soil hydraulic properties, which control surface fluxes and storage of water and chemicals in the soil profile, vary in space and time. Spatial variability above the measurement scale (e.g., soil area of 0.07 m2 or support volume of 14 L) must be upscaled appropriately to determine “effective” hydr...

  2. Effects of sand compaction and mixing on pore structure and the unsaturated soil hydraulic properties

    NARCIS (Netherlands)

    Mahmoodlu, Mojtaba Ghareh; Raoof, A.; Sweijen, T.; van Genuchten, M. Th

    2016-01-01

    The hydraulic properties of unsaturated porous media very much depend on their pore structure as defined by the size, arrangement, and connectivity of pores. Several empirical and quasi-empirical approaches have been used over the years to derive pore structure information from the particle size

  3. Three-Dimensional poroelastic effects during hydraulic fracturing in permeable rocks

    DEFF Research Database (Denmark)

    Salimzadeh, Saeed; Paluszny, Adriana; Zimmerman, Robert W.

    2017-01-01

    A fully coupled three-dimensional finite-element model for hydraulic fractures in permeable rocks is presented, and used to investigate the ranges of applicability of the classical analytical solutions that are known to be valid in limiting cases. This model simultaneously accounts for fluid flow...

  4. Effect of Hydraulic Accumulator on Pressure Surge of a Hydrostatic Transmission System

    Science.gov (United States)

    Kumar, Ajit; Das, Jayanta; Dasgupta, Kabir; Barnwal, Manish Kumar

    2018-04-01

    Hydraulic power system is generally used in off-road vehicles for power transmission such as Heavy Earth Moving Machineries (HEMM). Their energy efficiency and unsubstantial failure becomes an extensive subject of analysis. Various arrangements in the system are compassed along with the utilization of some appropriate components. Application of a hydraulic accumulator is one among them. Benefits of accumulator is its multi-purpose usages like energy saving and pressure surge damping. This paper deals with the control of pressure surges in the hydraulic system and energy saving from the surges by using accumulator. For this purpose, the simulation of the hydraulic system is done in MATLAB/SimulinkR environment and an external disturbance is introduced to generate the pressure surge. The surge absorptivity of the accumulator is studied for different sizes at different pre-charged conditions of the accumulator. The discharge characteristics of different sized accumulators are also analyzed in this paper. It is observed that the ability to absorb the surge and stabilize the system is high in the smaller capacity accumulator. However the energy delivery time of larger sized accumulator is high.

  5. Subsurface Flow and Moisture Dynamics in Response to Swash Motions: Effects of Beach Hydraulic Conductivity and Capillarity

    Science.gov (United States)

    Geng, Xiaolong; Heiss, James W.; Michael, Holly A.; Boufadel, Michel C.

    2017-12-01

    A combined field and numerical study was conducted to investigate dynamics of subsurface flow and moisture response to waves in the swash zone of a sandy beach located on Cape Henlopen, DE. A density-dependent variably saturated flow model MARUN was used to simulate subsurface flow beneath the swash zone. Values of hydraulic conductivity (K) and characteristic pore size (α, a capillary fringe property) were varied to evaluate their effects on subsurface flow and moisture dynamics in response to swash motions in beach aquifers. The site-specific modeling results were validated against spatiotemporal measurements of moisture and pore pressure in the beach. Sensitivity analyses indicated that the hydraulic conductivity and capillary fringe thickness of the beach greatly influenced groundwater flow pathways and associated transit times in the swash zone. A higher value of K enhanced swash-induced seawater infiltration into the beach, thereby resulting in a faster expansion of a wedge of high moisture content induced by swash cycles, and a flatter water table mound beneath the swash zone. In contrast, a thicker capillary fringe retained higher moisture content near the beach surface, and thus, significantly reduced the available pore space for infiltration of seawater. This attenuated wave effects on pore water flow in the unsaturated zone of the beach. Also, a thicker capillary fringe enhanced horizontal flow driven by the larger-scale hydraulic gradient caused by tides.

  6. Short-term effects of light quality on leaf gas exchange and hydraulic properties of silver birch (Betula pendula).

    Science.gov (United States)

    Niglas, Aigar; Papp, Kaisa; Sekiewicz, Maciej; Sellin, Arne

    2017-09-01

    Leaves have to acclimatize to heterogeneous radiation fields inside forest canopies in order to efficiently exploit diverse light conditions. Short-term effects of light quality on photosynthetic gas exchange, leaf water use and hydraulic traits were studied on Betula pendula Roth shoots cut from upper and lower thirds of the canopy of 39- to 35-year-old trees growing in natural forest stand, and illuminated with white, red or blue light in the laboratory. Photosynthetic machinery of the leaves developed in different spectral conditions acclimated differently with respect to incident light spectrum: the stimulating effect of complete visible spectrum (white light) on net photosynthesis is more pronounced in upper-canopy layers. Upper-canopy leaves exhibit less water saving behaviour, which may be beneficial for the fast-growing pioneer species on a daily basis. Lower-canopy leaves have lower stomatal conductance resulting in more efficient water use. Spectral gradients existing within natural forest stands represent signals for the fine-tuning of stomatal conductance and tree water relations to afford lavish water use in sun foliage and enhance leaf water-use efficiency in shade foliage sustaining greater hydraulic limitations. Higher sensitivity of hydraulic conductance of shade leaves to blue light probably contributes to the efficient use of short duration sunflecks by lower-canopy leaves. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  7. Multiscale pore networks and their effect on deformation and transport property alteration associated with hydraulic fracturing

    Science.gov (United States)

    Daigle, Hugh; Hayman, Nicholas; Jiang, Han; Tian, Xiao; Jiang, Chunbi

    2017-04-01

    clusters of organic-hosted pores prevents the overpressure from dissipating, resulting in localized overpressure at the micron scale. When the rock is subjected to a hydraulic fracture stimulation, the rock surrounding the main induced fracture experiences shear deformation. Those parts of the rock that contain overpressured fluids in the organic-hosted pores will be more likely to experience dilatancy in the form of brittle deformation; the portions of the rock lacking in organic-hosted pores will tend to experience compactive shear failure since the effective normal stresses are larger. The microcrack networks that propagate into the regions of organic-hosted porosity allow the hydrocarbons resident in those pores to migrate to the main induced tensile fractures. The disconnected nature of the microcrack networks causes only a slight increase in permeability, which is consistent with other observations. Our work illustrates how multiscale pore networks in shale interact with in situ stresses to affect the bulk shale rheology.

  8. Effects of native forest restoration on soil hydraulic properties, Auwahi, Maui, Hawaiian Islands

    Science.gov (United States)

    Perkins, Kimberlie S.; Nimmo, John R.; Medeiros, Arthur C.

    2012-01-01

    Over historic time Hawai'i's dryland forests have been largely replaced by grasslands for grazing livestock. On-going efforts have been undertaken to restore dryland forests to bring back native species and reduce erosion. The reestablishment of native ecosystems on land severely degraded by long-term alternative use requires reversal of the impacts of erosion, organic-matter loss, and soil structural damage on soil hydraulic properties. This issue is perhaps especially critical in dryland forests where the soil must facilitate native plants' optimal use of limited water. These reforestation efforts depend on restoring soil ecological function, including soil hydraulic properties. We hypothesized that reforestation can measurably change soil hydraulic properties over restoration timescales. At a site on the island of Maui (Hawai'i, USA), we measured infiltration capacity, hydrophobicity, and abundance of preferential flow channels in a deforested grassland and in an adjacent area where active reforestation has been going on for fourteen years. Compared to the nearby deforested rangeland, mean field-saturated hydraulic conductivity in the newly restored forest measured by 55 infiltrometer tests was greater by a factor of 2.0. Hydrophobicity on an 8-point scale increased from average category 6.0 to 6.9. A 4-point empirical categorization of preferentiality in subsurface wetting patterns increased from an average 1.3 in grasslands to 2.6 in the restored forest. All of these changes act to distribute infiltrated water faster and deeper, as appropriate for native plant needs. This study indicates that vegetation restoration can lead to ecohydrologically important changes in soil hydraulic properties over decadal time scales.

  9. A comparison of RAM importance measures

    International Nuclear Information System (INIS)

    Atwood, C.L.; Wolford, A.J.; Wright, R.E.

    1989-01-01

    In this paper measures of importance of components and cut sets of a system are reviewed. The measures considered are based on reliability, availability, and maintainability, the three elements of the acronym RAM. They follow the approaches of Fussell and Vesely and of Birnbaum. A new Birnbaum-type unmaintainability importance measure is proposed. The measures are compared in a simple example, and the appropriate use of unmaintainability importance is discussed

  10. Improvement of auditing technology of safety analysis through thermal-hydraulic separate effect tests

    Energy Technology Data Exchange (ETDEWEB)

    No, Hee Cheon; Moon, Young Min; Lee, Dong Won; Lee, Sang Ik; Kim, Eung Soo; Yeom, Keum Soo [Korea Advanced Institute of Science and Technology, Taejon (Korea, Republic of)

    2002-03-15

    The objective of the present research is to perform the separate effect tests and to assess the RELAP5/MOD3.2 code for the analysis of thermal-hydraulic behavior in the reactor coolant system and the improvement of the auditing technology of safety analysis. Three Separate Effect Tests (SETs) are the reflux condensation in the U-tube, the direct contact condensation in the hot-leg and the mixture level buildup in the pressurizer. The experimental data and the empirical correlations are obtained through SETs. On the ases of the three SET works, models in RELAP5 are modified and improved, which are compared with the data. The Korea Standard Nuclear Power Plant (KSNP) are assessed using the modified RELAP5. In the reflux condensation test, the data of heat transfer coefficients and flooding are obtained and the condensation models are modified using the non-iterative model, as results, modified code better predicts the data. In the direct contact condensation test, the data of heat transfer coefficients are obtained for the cocurrent and countercurrent flow between the mixture gas and the water in condition of horizontal stratified flow. Several condensation and friction models are modified, which well predict the present data. In the mixture level test, the data for the mixture level and the onset of water draining into the surge line are obtained. The standard RELAP5 over-predicts the mixture level and the void fraction in the pressurizer. Simple modification of model related to the pool void fraction is suggested. The KSNP is assessed using the standard and the modified RELAP5 resulting from the experimental and code works for the SETs. In case of the pressurizer manway opening with available secondary side of the steam generators, the modified code predicts that the collapsed level in the pressurizer is little accumulated. The presence and location of the opening and the secondary condition of the steam generators have an effect on the coolant inventory. The

  11. Shear Ram Verification Test Protocol (VTP) Best Practices

    Energy Technology Data Exchange (ETDEWEB)

    Lindley, Roy A. [Argonne National Lab. (ANL), Argonne, IL (United States); Braun, Joseph C. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2017-01-01

    A blowout preventer (BOP) is a critical component used on subsea oil and gas wells during drilling, completion, and workover operations on the U. S. outer continental shelf (OCS). The purpose of the BOP is to seal oil and gas wells, and in the case of an emergency well-control event, to prevent the uncontrolled release of hydrocarbons. One of the most important components of the BOP is the hydraulically operated blind shear ram (BSR) that shears drilling-related components, such as drill pipes, casings, tubings, and wire-related tools that may have been placed in the well. In addition to shearing these components, the BSR must form a seal to keep hydrocarbons within the well bore, even when under the highest well-fluid pressures expected. The purpose of this document is for Argonne National Laboratory (ANL) to provide an independent view, based on current regulations, and best practices for testing and confirming the operability and suitability of BSRs under realistic (or actual) well conditions.

  12. Effects of land use and management on aggregate stability and hydraulic conductivity of soils within River Njoro Watershed in Kenya

    Directory of Open Access Journals (Sweden)

    Zachary G. Mainuri

    2013-09-01

    Full Text Available There has been tremendous changes in land use and management in the River Njoro Watershed during the last three decades. Formerly large scale farms have been converted into smallholder farms and plantation forests have gradually been lost. These changes in land use and management have brought in different approaches that have triggered soil erosion and other forms of land degradation. The objective of this study was to trace the changes in land use and determine their effects on aggregate stability and hydraulic conductivity. A semi detailed soil survey of the watershed was undertaken following a three-tier approach comprising image interpretation, field surveys and laboratory analysis. The measured variables in the soil were analysed using ANOVA and correlation analysis. The major land uses were found to be forestland, agricultural land, grassland, and wetland. A strong soil type _ landscape relationship was observed within the watershed. Soils of slopes were moderately to severely eroded, shallow and less developed whereas those on summits, pen plains, uplands, plateaus and valleys were deep and well developed. Aggregate stability was the highest in forestland and decreased in the order of grassland, agricultural land and wetland respectively. The mean weight diameter under the various land use conditions was 0.68, 0.64, 0.58, and 0 41 respectively. Hydraulic conductivity was the highest in forest-land and decreased in the order of agricultural land, grassland and wetland respectively. There was significant negative correlation between hydraulic conductivity and the bulk density and clay content of the soils. Reduced aggregate stability and lowered hydraulic conductivity is likely to be responsible for some of the severe soil erosion and other forms of land degradation observed in the River Njoro Watershed.

  13. Effects of draft tube on the hydraulic performance of a Francis turbine

    International Nuclear Information System (INIS)

    Jeon, J H; Byeon, S S; Kim, Y J

    2013-01-01

    The draft tube is an important component of a Francis turbine which influences the hydraulic performance. It is located just under the runner and allowed to decelerate the flow velocity exiting the runner, thereby converting the excess of kinetic energy into static pressure. In this study, we have numerically investigated the hydraulic performance of a Francis turbine on the 15MW hydropower generation with various design parameters (three types of draft tube, thickness of guide vane) through a three-dimensional numerical method with the SST turbulent model. The vortex rope characteristics of the draft tube were confirmed. The results of the vortex flow fields and flow characteristics were graphically depicted with different design parameters and operating conditions

  14. Simple deterministic model of the hydraulic buffer effect in septic tanks

    OpenAIRE

    Forquet, N.; Dufresne, M.

    2015-01-01

    Septic tanks are widely used in on-site wastewater treatment systems. In addition to anaerobic pre-treatment, hydraulic buffering is one of the roles attributed to septic tanks. However there is still no tool for assessing it, especially in dynamic conditions. For gravity fed system, it could help both researchers and system designers. This technical note reports a simple mechanistic model based on the assumption of flow transition between the septic tank and the outflow pipe. The only parame...

  15. Hydraulic effects on nitrogen removal in a tidal spring-fed river

    Science.gov (United States)

    Hensley, Robert T.; Cohen, Matthew J.; Korhnak, Larry V.

    2015-03-01

    Hydraulic properties such as stage and residence time are important controls on riverine N removal. In most rivers, these hydraulic properties vary with stochastic precipitation forcing, but in tidal rivers, hydraulics variation occurs on a predictable cycle. In Manatee Springs, a highly productive, tidally influenced spring-fed river in Florida, we observed significant reach-scale N removal that varied in response to tidally driven variation in hydraulic properties as well as sunlight-driven variation in assimilatory uptake. After accounting for channel residence time and stage variation, we partitioned the total removal signal into assimilatory (i.e., plant uptake) and dissimilatory (principally denitrification) pathways. Assimilatory uptake was strongly correlated with primary production and ecosystem C:N was concordant with tissue stoichiometry of the dominant autotrophs. The magnitude of N removal was broadly consistent in magnitude with predictions from models (SPARROW and RivR-N). However, contrary to model predictions, the highest removal occurred at the lowest values of τ/d (residence time divided by depth), which occurred at low tide. Removal efficiency also exhibited significant counterclockwise hysteresis with incoming versus outgoing tides. This behavior is best explained by the sequential filling and draining of transient storage zones such that water that has spent the longest time in the storage zone, and thus had the most time for N removal, drains back into the channel at the end of an outgoing tide, concurrent with shortest channel residence times. Capturing this inversion of the expected relationship between channel residence time and N removal highlights the need for nonsteady state reactive transport models.

  16. Cost-Effective and High-Resolution Subsurface Characterization Using Hydraulic Tomography

    Science.gov (United States)

    2017-08-28

    of this project is to provide the Department of Defense (DoD) and its remediation contractors with the Hydraulic Tomography ( HT ) technology for...objective of this project is to provide the DoD and its remediation contractors with the HT technology for delineating the spatial distribution of the...SPONSOR/MONITOR’S REPORT NUMBER(S) ER-201212 The overall objective of this project is to provide the DoD and its remediation contractors with the

  17. EFFECT OF PROVIDING INFORMATION ON STUDENTS’ KNOWLEDGE AND CONCERNS ABOUT HYDRAULIC FRACKING

    OpenAIRE

    Burger, Joanna; Nakata, Kimi; Liang, Laura; Pittfield, Taryn; Jeitner, Christian

    2015-01-01

    Governmental agencies, regulators, health professionals, and the public are faced with understanding and responding to new development practices and conditions in their local and regional environment. While hydraulic fracking (fracking) for shale gas has been practiced for over 50 years in some states, it is a relatively recent event in the northeastern United States. Providing environmental health information to the public about fracking requires understanding both the knowledge base and the...

  18. Estimation of the effectiveness of the destruction of natural stone oversized by a hydraulic hammer

    Directory of Open Access Journals (Sweden)

    V.G. Kravets

    2017-12-01

    Full Text Available The experience of mining operations shows that even with the application of progressive methods of drilling, it is impossible to completely exclude the output of a large fraction (oversized. The percentage of oversized mass emissions from the blasting mass depending on the mining and geological conditions may vary from 5 to 20 percent. Catching an oversized piece into the receiving slit of the main crusher is associated with stopping the whole technological chain of the enterprise. Sharpening of oversized pieces of the work area during conducting of extraction or overturning works leads to a decrease in the efficiency of mining operations. Crushing of oversized materials to the required sizes can be carried out in an explosive way (by a bore or overhead charge or by non-explosive methods, most of which are based on mechanical destruction under the action of local dynamic stresses that cause stress exceeding the resistance of internal bonds in the rock. To date, manufacturers are offered many types of shock mechanisms, based on the transformation of various types of energy (from gravitational, to the energy of chemical processes into mechanical. For a number of reasons, mostly economic, to date, the most common way is the mechanical method of the destruction of oversized beams using hydraulic and hydro pneumatic hammer. That is why the work considers the main factors influencing the performance of the hydraulic hammer, among which – the specific energy consumption of the oversize and the main parameters of the hydraulic engine passport on the basis of the excavator. In the publication the power law of the hydraulic hammer changes in dependence of the size of the oversized. Also, the basic parameters of the JCB JS235 HD excavator passport are defined in the work with the use of the INDECO HP 1500 hammer hammer.

  19. Effects of prolonged drought on stem non-structural carbohydrates content and post-drought hydraulic recovery in Laurus nobilis L.: The possible link between carbon starvation and hydraulic failure.

    Science.gov (United States)

    Trifilò, Patrizia; Casolo, Valentino; Raimondo, Fabio; Petrussa, Elisa; Boscutti, Francesco; Lo Gullo, Maria Assunta; Nardini, Andrea

    2017-11-01

    Drought-induced tree decline is a complex event, and recent hypotheses suggest that hydraulic failure and carbon starvation are co-responsible for this process. We tested the possible role of non-structural carbohydrates (NSC) content on post-drought hydraulic recovery, to verify the hypothesis that embolism reversal represents a mechanistic link between carbon starvation and stem hydraulics. Measurements were performed in laurel plants subjected to similar water stress levels either over short or long term, to induce comparable embolism levels. Plants subjected to mild and prolonged water shortage (S) showed reduced growth, adjustment of turgor loss point driven by changes in both osmotic potential at full turgor and bulk modulus of elasticity, a lower content of soluble NSC and a higher content of starch with respect to control (C) plants. Moreover, S plants showed a lower ability to recover from xylem embolism than C plants, even after irrigation. Our data suggest that plant carbon status might indirectly influence plant performance during and after drought via effects on xylem hydraulic functioning, supporting the view of a possible mechanistic link between the two processes. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  20. Improvement of auditing technology of safety analysis through thermal-hydraulic separate effect tests

    Energy Technology Data Exchange (ETDEWEB)

    No, Hee Cheon; Park, Hyun Sik; Kim, Hyoung Tae; Moon, Young Min; Choi, Sung Won; Hwang, Do Hyun [Korea Advanced Institute of Science and Technology, Taejon (Korea, Republic of)

    2000-03-15

    The direct-contact condensation hear transfer coefficients are experimentally obtained in the following conditions : pure steam/steam in the presence of noncondensible gas, horizontal/slightly inclined pipe, cocurrent/countercurrent stratified flow with water. The empirical correlation for liquid Nusselt number is developed in conditions of the slightly inclined pipe and the cocurrent stratified flow. The several models - the wall friction coefficient, the interfacial friction coefficient, the correlation of direct-contact condensation with noncondensible gases, and the correlation of wall film condensation - in the RELAP5/MOD3.2 code are modified, As results, RELAP5/MOD3.2 is improved. The present experimental data is used for evaluating the improved code. The standard RELAP5/MOD3.2 code is modified using the non-iterative modeling, which is a mechanistic model and does not require any interfacial information such as the interfacial temperature, The modified RELAP5/MOD3.2 code os used to simulate the horizontally stratified in-tube condensation experiment which represents the direct-contact condensation phenomena in a hot leg of a nuclear reactor. The modeling capabilities of the modified code as well as the standard code are assessed using several hot-leg condensation experiments. The modified code gives better prediction over local experimental data of liquid void fraction and interfacial heat transfer coefficient than the standard code. For the separate effect test of the thermal-hydraulic phenomena in the pressurizer, the scaling analysis is performed to obtain a similarity of the phenomena between the Korea Standard Nuclear Power Plant(KSNPP) and the present experimental facility. The diameters and lengths of the hot-leg, the surge line and the pressurizer are scaled down with the similitude of CCFL and velocity. The ratio of gas flow rate is 1/25. The experimental facility is composed of the air-water supply tank, the horizontal pipe, the surge line and the

  1. Acrotelm pedogenesis of a Sphagnum bog is reflected in effective unsaturated hydraulic properties

    Science.gov (United States)

    Weber, Tobias K. D.; Iden, Sascha C.; Durner, Wolfgang

    2017-04-01

    In ombrotrophic peatlands, the moisture content of the vadose zone (acrotelm) controls oxygen diffusion rates, redox state, and the turnover of organic matter. Whether peatlands act as sinks or sources of atmospheric carbon thus relies on variably saturated flow processes. Modeling of these processes is crucial in assessing effects of changed environmental conditions on the future development of these ecosystems. The Richards equation (RE) is the standard model for water flow in soils, but it is not clear whether it can be applied to simulate water flow in live Sphagnum moss. To check the suitability of the RE to describe the water dynamics in drying moss and peat we conducted transient laboratory evaporation experiments on undisturbed samples from the entire acrotelm. The experimental data consisted of measured pressure heads in two depths and water fluxes, and were evaluated by inverse modelling using the RE as process model. The results showed that the measurements could be matched very well only if the soil hydraulic properties (SHPs) were represented by a suitable model. A successful parameterisation of the SHPs of the moss was based on pore-size distributions (PSD) which combine three distinct pore systems of the Sphagnum moss, reflecting an inter-, intra-, and inner-plant pore space. We had to extend the traditional van Genuchten-Mualem model to account for non-capillary water storage and flow to obtain consistent descriptions of the observations. For the deeper samples, the pedogenesis of the acrotelm, a process of compaction and biochemical degradation of the solid matrix, had considerably impact on the shape of the SHPs. The collapse of the inter-plant pores and their filling with smaller particles led gradually to bi-modal PSDs with increasing depth. This coincides with a homogenisation and a considerably reduction in horizontal variability of SHPs at greater depths. We conclude that the RE with adequate representation of SHPs is a valid process

  2. Effect of Random Natural Fractures on Hydraulic Fracture Propagation Geometry in Fractured Carbonate Rocks

    Science.gov (United States)

    Liu, Zhiyuan; Wang, Shijie; Zhao, Haiyang; Wang, Lei; Li, Wei; Geng, Yudi; Tao, Shan; Zhang, Guangqing; Chen, Mian

    2018-02-01

    Natural fractures have a significant influence on the propagation geometry of hydraulic fractures in fractured reservoirs. True triaxial volumetric fracturing experiments, in which random natural fractures are created by placing cement blocks of different dimensions in a cuboid mold and filling the mold with additional cement to create the final test specimen, were used to study the factors that influence the hydraulic fracture propagation geometry. These factors include the presence of natural fractures around the wellbore, the dimension and volumetric density of random natural fractures and the horizontal differential stress. The results show that volumetric fractures preferentially formed when natural fractures occurred around the wellbore, the natural fractures are medium to long and have a volumetric density of 6-9%, and the stress difference is less than 11 MPa. The volumetric fracture geometries are mainly major multi-branch fractures with fracture networks or major multi-branch fractures (2-4 fractures). The angles between the major fractures and the maximum horizontal in situ stress are 30°-45°, and fracture networks are located at the intersections of major multi-branch fractures. Short natural fractures rarely led to the formation of fracture networks. Thus, the interaction between hydraulic fractures and short natural fractures has little engineering significance. The conclusions are important for field applications and for gaining a deeper understanding of the formation process of volumetric fractures.

  3. Kinematics of ram filter feeding and beat-glide swimming in the northern anchovy Engraulis mordax.

    Science.gov (United States)

    Carey, Nicholas; Goldbogen, Jeremy A

    2017-08-01

    In the dense aquatic environment, the most adept swimmers are streamlined to reduce drag and increase the efficiency of locomotion. However, because they open their mouth to wide gape angles to deploy their filtering apparatus, ram filter feeders apparently switch between diametrically opposite swimming modes: highly efficient, streamlined 'beat-glide' swimming, and ram filter feeding, which has been hypothesized to be a high-cost feeding mode because of presumed increased drag. Ram filter-feeding forage fish are thought to play an important role in the flux of nutrients and energy in upwelling ecosystems; however, the biomechanics and energetics of this feeding mechanism remain poorly understood. We quantified the kinematics of an iconic forage fish, the northern anchovy, Engraulis mordax , during ram filter feeding and non-feeding, mouth-closed beat-glide swimming. Although many kinematic parameters between the two swimming modes were similar, we found that swimming speeds and tailbeat frequencies were significantly lower during ram feeding. Rather than maintain speed with the school, a speed which closely matches theoretical optimum filter-feeding speeds was consistently observed. Beat-glide swimming was characterized by high variability in all kinematic parameters, but variance in kinematic parameters was much lower during ram filter feeding. Under this mode, body kinematics are substantially modified, and E. mordax swims more slowly and with decreased lateral movement along the entire body, but most noticeably in the anterior. Our results suggest that hydrodynamic effects that come with deployment of the filtering anatomy may limit behavioral options during foraging and result in slower swimming speeds during ram filtration. © 2017. Published by The Company of Biologists Ltd.

  4. The effect of hydraulic retention time in onsite wastewater treatment and removal of pharmaceuticals, hormones and phenolic utility substances.

    Science.gov (United States)

    Ejhed, H; Fång, J; Hansen, K; Graae, L; Rahmberg, M; Magnér, J; Dorgeloh, E; Plaza, G

    2018-03-15

    Micropollutants such as pharmaceuticals, hormones and phenolic utility chemicals in sewage water are considered to be an emerging problem because of increased use and observed adverse effects in the environment. The study provides knowledge on the removal efficiency of micropollutants with a range of physical and chemical properties in three commercially available onsite wastewater treatment facilities (OWTFs), tested on influent wastewater collected from 2500 person equivalents in Bildchen, Germany. A longer hydraulic retention time would in theory be expected to have a positive effect, and this study presents results for three different OWTFs in full-scale comparable tests under natural conditions. A range of 24 different pharmaceuticals, five phenols and three hormones were analyzed. Flow-proportional consecutive sampling was performed in order to determine the removal efficiency. Twenty-eight substances were detected in the effluent wastewater out of 32 substances included. Average effluent concentrations of Simvastatin, Estrone, Estradiol and Ethinylestradiol were above the indicative critical-effect concentration of pharmacological effect on fish in all facilities. Average effluent concentrations of both Diclofenac and Estradiol were higher than the Environmental Quality Standards applied in Sweden (190-240 times and 9-35 times respectively). The removal efficiency of micropollutants was high for substances with high logK ow , which enhance the adsorption and removal with sludge. Low removal was observed for substances with low logK ow and acidic characteristics, and for substances with stabilizing elements of the chemical structure. Facilities that use activated sludge processes removed hormones more efficiently than facilities using trickling filter treatment technique. Moreover, longer hydraulic retention time increased the removal of pharmaceuticals, hormones, turbidity and total nitrogen. Removal of Caffeine, Ibuprofen, Estrone, Naproxen and Estradiol

  5. Growth performance and hematology of Djallonké rams fed haulms of four varieties of groundnut (Arachis hypogaea L.

    Directory of Open Access Journals (Sweden)

    Terry Ansah

    2017-12-01

    Full Text Available The study was conducted to assess the chemical composition of the haulms of 4 dual-purpose groundnut (Arachis hypogaea L. varieties and their effects on the growth and hematology of Djallonké rams. The groundnut varieties were ICGV 97049 (Obolo, ICGX SM 87057 (Yenyawoso, RMP 12 (Azivivi and Manipinta. Rams (live weight 15.0 ± 3.0 kg were randomly assigned to 4 sole groundnut haulm meal (GHM treatments, with 4 rams each in an individual pen per treatment (total n = 16 rams. Samples of the groundnut haulms were milled and analyzed for crude protein (CP, neutral detergent fiber (NDF and acid detergent fiber (ADF. The CP concentration was higher (P  0.05 when the Djallonké rams were fed the haulms. However, significant differences were observed in final live weight and average daily live weight gain. Rams fed the Yenyawoso variety had higher (P < 0.05 final live weight and average daily live weight gain compared with those fed Obolo and Azivivi varieties. Consumption of any of the 4 varieties of groundnut haulms by Djallonké rams did not have any harmful effect on their red and white blood cell numbers and hemoglobin concentration. The study revealed that the different varieties of groundnut haulms differ in nutrient composition and also affect the growth performance of the rams. The Yenyawoso variety may be used as a sole diet for fattening Djallonké rams.

  6. RAM-efficient external memory sorting

    DEFF Research Database (Denmark)

    Arge, Lars; Thorup, Mikkel

    2013-01-01

    In recent years a large number of problems have been considered in external memory models of computation, where the complexity measure is the number of blocks of data that are moved between slow external memory and fast internal memory (also called I/Os). In practice, however, internal memory time...... often dominates the total running time once I/O-efficiency has been obtained. In this paper we study algorithms for fundamental problems that are simultaneously I/O-efficient and internal memory efficient in the RAM model of computation....

  7. Radiation-hardened nonvolatile MNOS RAM

    International Nuclear Information System (INIS)

    Wrobel, T.F.; Dodson, W.H.; Hash, G.L.; Jones, R.V.; Nasby, R.D.; Olson, R.J.

    1983-01-01

    A radiation hardened nonvolatile MNOS RAM is being developed at Sandia National Laboratories. The memory organization is 128 x 8 bits and utilizes two p-channel MNOS transistors per memory cell. The peripheral circuitry is constructed with CMOS metal gate and is processed with standard Sandia rad-hard processing techniques. The devices have memory retention after a dose-rate exposure of 1E12 rad(Si)/s, are functional after total dose exposure of 1E6 rad(Si), and are dose-rate upset resistant to levels of 7E8 rad(Si)/s

  8. CEPRAM: Compression for Endurance in PCM RAM

    OpenAIRE

    González Alberquilla, Rodrigo; Castro Rodríguez, Fernando; Piñuel Moreno, Luis; Tirado Fernández, Francisco

    2017-01-01

    We deal with the endurance problem of Phase Change Memories (PCM) by proposing Compression for Endurance in PCM RAM (CEPRAM), a technique to elongate the lifespan of PCM-based main memory through compression. We introduce a total of three compression schemes based on already existent schemes, but targeting compression for PCM-based systems. We do a two-level evaluation. First, we quantify the performance of the compression, in terms of compressed size, bit-flips and how they are affected by e...

  9. Large Dam Effects on Flow Regime and Hydraulic Parameters of river (Case study: Karkheh River, Downstream of Reservoir Dam

    Directory of Open Access Journals (Sweden)

    Farhang Azarang

    2017-06-01

    Full Text Available Introduction: The critical role of the rivers in supplying water for various needs of life has led to engineering identification of the hydraulic regime and flow condition of the rivers. Hydraulic structures such dams have inevitable effects on their downstream that should be well investigated. The reservoir dams are the most important hydraulic structures which are the cause of great changes in river flow conditions. Materials and Methods: In this research, an accurate assessment was performed to study the flow regime of Karkheh river at downstream of Karkheh Reservoir Dam as the largest dam in Middle East. Karkheh River is the third waterful river of Iran after Karun and Dez and the third longest river after the Karun and Sefidrud. The Karkheh Dam is a large reservoir dam built in Iran on the Karkheh River in 2000. The Karkheh Reservoir Dam is on the Karkheh River in the Northwestern Khouzestan Province, the closest city being Andimeshk to the east. The part of Karkheh River, which was studied in this research is located at downstream of Karkheh Reservoir Dam. This interval is approximately 94 km, which is located between PayePol and Abdolkhan hydrometric stations. In this research, 138 cross sections were used along Karkheh River. Distance of cross sections from each other was 680m in average. The efficient model of HEC-RAS has been utilized to simulate the Karkheh flow conditions before and after the reservoir dam construction using of hydrometric stations data included annually and monthly mean discharges, instantaneous maximum discharges, water surface profiles and etc. Three defined discharges had been chosen to simulate the Karkheh River flow; maximum defined discharge, mean defined discharge and minimum defined discharge. For each of these discharges values, HEC-RAS model was implemented as a steady flow of the Karkheh River at river reach of study. Water surface profiles of flow, hydraulic parameters and other results of flow regime in

  10. Evaluation of parameters effect on the maximum fuel temperature in the core thermal and hydraulic design of HTTR

    International Nuclear Information System (INIS)

    Fujimoto, Nozomu; Maruyama, Soh; Sudo, Yukio; Fujii, Sadao; Niguma, Yoshinori.

    1988-10-01

    This report presents the results of quantitative evaluation on the effects of the dominant parameters on the maximum fuel temperature in the core thermal hydraulic design of the High Temperature Engineering Test Reactor(HTTR) of 30 MW in thermal power, 950 deg C in reactor outlet coolant temperature and 40 kg/cm 2 G in coolant pressure. The dominant parameters investigated are 1) Gap conductance. 2) Effect of eccertricity of fuel compacts in graphite sleeve. 3) Effect of spacer ribs on heat transfer coefficients. 4) Contact probability of fuel compact and graphite sleeve. 5) Validity of uniform radial power density in the fuel compacts. 6) Effect of impurity gas on gap conductance. 7) Effect of FP gas on gap conductance. The effects of these items on the maximum fuel temperature were quantitalively identified as hot spot factors. A probability of the appearance of the maximum fuel temperature was also evaluated in this report. (author)

  11. Coupling hydrologic and hydraulic models to take into consideration retention effects on extreme peak discharges in Switzerland

    Science.gov (United States)

    Felder, Guido; Zischg, Andreas; Weingartner, Rolf

    2015-04-01

    Estimating peak discharges with very low probabilities is still accompanied by large uncertainties. Common estimation methods are usually based on extreme value statistics applied to observed time series or to hydrological model outputs. However, such methods assume the system to be stationary and do not specifically consider non-stationary effects. Observed time series may exclude events where peak discharge is damped by retention effects, as this process does not occur until specific thresholds, possibly beyond those of the highest measured event, are exceeded. Hydrological models can be complemented and parameterized with non-linear functions. However, in such cases calibration depends on observed data and non-stationary behaviour is not deterministically calculated. Our study discusses the option of considering retention effects on extreme peak discharges by coupling hydrological and hydraulic models. This possibility is tested by forcing the semi-distributed deterministic hydrological model PREVAH with randomly generated, physically plausible extreme precipitation patterns. The resulting hydrographs are then used to force the hydraulic model BASEMENT-ETH (riverbed in 1D, potential inundation areas in 2D). The procedure ensures that the estimated extreme peak discharge does not exceed the physical limit given by the riverbed capacity and that the dampening effect of inundation processes on peak discharge is considered.

  12. Reforesting severely degraded grassland in the Lesser Himalaya of Nepal: Effects on soil hydraulic conductivity and overland flow production

    Science.gov (United States)

    Ghimire, Chandra Prasad; Bonell, Mike; Bruijnzeel, L. Adrian; Coles, Neil A.; Lubczynski, Maciek W.

    2013-12-01

    degraded hillslopes in the Lesser Himalaya challenge local communities as a result of the frequent occurrence of overland flow and erosion during the rainy season and water shortages during the dry season. Reforestation is often perceived as an effective way of restoring predisturbance hydrological conditions but heavy usage of reforested land in the region has been shown to hamper full recovery of soil hydraulic properties. This paper investigates the effect of reforestation and forest usage on field-saturated soil hydraulic conductivities (Kfs) near Dhulikhel, Central Nepal, by comparing degraded pasture, a footpath within the pasture, a 25 year old pine reforestation, and little disturbed natural forest. The hillslope hydrological implications of changes in Kfs with land-cover change were assessed via comparisons with measured rainfall intensities over different durations. High surface and near-surface Kfs in natural forest (82-232 mm h-1) rule out overland flow occurrence and favor vertical percolation. Conversely, corresponding Kfs for degraded pasture (18-39 mm h-1) and footpath (12-26 mm h-1) were conducive to overland flow generation during medium- to high-intensity storms and thus to local flash flooding. Pertinently, surface and near-surface Kfs in the heavily used pine forest remained similar to those for degraded pasture. Estimated monsoonal overland flow totals for degraded pasture, pine forest, and natural forest were 21.3%, 15.5%, and 2.5% of incident rainfall, respectively, reflecting the relative ranking of surface Kfs. Along with high water use by the pines, this lack of recovery of soil hydraulic properties under pine reforestation is shown to be a critical factor in the regionally observed decline in base flows following large-scale planting of pines and has important implications for regional forest management.

  13. Hydraulic manipulator

    International Nuclear Information System (INIS)

    Sinha, A.K.; Srikrishnamurty, G.

    1990-01-01

    Successful operation of nuclear plant is largely dependent on safe handling of radio-active material. In order to reduce this handling problem and minimise the exposure of radiation, various handling equipment and manipulators have been developed according to the requirements. Manufacture of nuclear fuel, which is the most important part of the nuclear industry, involves handling of uranium ingots weighing approximately 250 kg. This paper describes a specially designed hydraulic manipulator for handling of the ingots in a limited space. It was designed to grab and handle the ingots in any position. This has following drive motions: (1)gripping and releasing, (2)lifting and lowering (z-motion), (3)rotation about the horizontal axis (azimuth drive), (4)rotation about the job axis, and (5)rotation about the vertical axis. For horizontal motion (X and Y axis motion) this equipment is mounted on a motorised trolley, so that it can move inside the workshop. For all drives except the rotation about the job axis, hydraulic cylinders have been used with a battery operated power pack. Trolley drive is also given power from same battery. This paper describes the design aspects of this manipulator. (author). 4 figs

  14. Ferroelectric materials for FeRAMs; FeRAM yo kyoyudentai zairyo

    Energy Technology Data Exchange (ETDEWEB)

    Miyasaka, Y [NEC Corp., Tokyo (Japan)

    1998-10-01

    Studies to utilize bistable spontaneous polarization of ferroelectric materials for non-volatile memory have already been started in the 1950`s. Recently, a possibility was indicated on a high-speed non-volatile RAM (FeRAM) with memory cell configuration combined with switching transistors as in DRAMs. This situation has led to performing very active studies on ferroelectric materials and electrode materials used in ferroelectric film cell capacitors. This paper summarizes the above research and development circumstances, as well as their future problems. On the other hand of having shown excellent fatigue resistance in the SrBi2Ta209(SBT) system, improvement has progressed steadily on the Pb(ZR, Ti)03 (abbreviated to PZT) system, which retains the mainstream position as the ferroelectric material for FeRAMs. Aiming at realizing a high integration FeRAM in the future will require discussions on property changes due to use of lower temperature and micronization in film formation, further improvement in relation with degradation such as in imprint, and elucidation of the mechanism. 31 refs., 3 figs.

  15. SeaRAM: an evaluation of the safety of RAM transport by sea

    International Nuclear Information System (INIS)

    McConnell, P.; Sorenson, K.B.; Carter, M.H.; Keane, M.P.; Keith, V.F.; Heid, R.J.

    1995-01-01

    SeaRAM is a multi-year Department of Energy (DOE) project designed to validate the safety of shipping radioactive materials (RAM) by sea. The project has an ultimate goal of developing and demonstrating analytic tools for performing comprehensive analyses to evaluate the risks to humans and the environment due to sea transport of plutonium, vitrified high-level waste (VHLW), and spent fuel associated with reprocessing and research reactors. To achieve this end, evaluations of maritime databases and structural an thermal analyses of particular severe collision and fire accidents have been and will continue to be conducted. Program management for SeaRAM is based at the DOE's Office of Environmental Restoration. Technical activities for the project are being conducted at Sandia National Laboratories (SNL). Several private organizations are also involved in providing technical support, notably Engineering Computer Optecnomics, Inc. (ECO). The technical work performed for SeaRAM also supports DOE participation in an International Atomic Energy Agency (IAEA) Cooperative Research Program (CRP) entitled Accident Severity at Sea During Transport of Radioactive Material. This paper discusses activities performed during the first year of the project

  16. The Development of Male-Oriented Behavior in Rams

    OpenAIRE

    Roselli, Charles E.; Reddy, Radhika; Kaufman, Katherine

    2011-01-01

    The sheep offers a unique mammalian model in which to study paradoxical same-sex sexual partner preferences. Variations in sexual partner preferences occur spontaneously with as many as 8% of rams in a population exhibiting a sexual preference for other rams (male-oriented). The current review presents an overview and update of the male-oriented ram model and discusses several theories that have been invoked to explain same sex preferences in this species. Although our understanding of the bi...

  17. Numerical analysis of the performance of rock weirs: Effects of structure configuration on local hydraulics

    Science.gov (United States)

    Holmquist-Johnson, C. L.

    2009-01-01

    River spanning rock structures are being constructed for water delivery as well as to enable fish passage at barriers and provide or improve the aquatic habitat for endangered fish species. Current design methods are based upon anecdotal information applicable to a narrow range of channel conditions. The complex flow patterns and performance of rock weirs is not well understood. Without accurate understanding of their hydraulics, designers cannot address the failure mechanisms of these structures. Flow characteristics such as jets, near bed velocities, recirculation, eddies, and plunging flow govern scour pool development. These detailed flow patterns can be replicated using a 3D numerical model. Numerical studies inexpensively simulate a large number of cases resulting in an increased range of applicability in order to develop design tools and predictive capability for analysis and design. The analysis and results of the numerical modeling, laboratory modeling, and field data provide a process-based method for understanding how structure geometry affects flow characteristics, scour development, fish passage, water delivery, and overall structure stability. Results of the numerical modeling allow designers to utilize results of the analysis to determine the appropriate geometry for generating desirable flow parameters. The end product of this research will develop tools and guidelines for more robust structure design or retrofits based upon predictable engineering and hydraulic performance criteria. ?? 2009 ASCE.

  18. Membangun Sistem Linux Mandrake Minimal Menggunakan Inisial Disk Ram

    OpenAIRE

    Wagito, Wagito

    2006-01-01

    Minimal Linux system is commonly used for special systems like router, gateway, Linux installer and diskless Linux system. Minimal Linux system is a Linux system that use a few facilities of all Linux capabilities. Mandrake Linux, as one of Linux distribution is able to perform minimal Linux system. RAM is a computer resource that especially used as main memory. A part of RAM's function can be changed into disk called RAM disk. This RAM disk can be used to run the Linux system. This ...

  19. Thermal-hydraulic evaluation study of the effectiveness of emergency core cooling system for light water reactors

    International Nuclear Information System (INIS)

    Sobajima, Makoto

    1985-08-01

    In order to evaluate the core cooling capability of the emergeny core cooling system, which is a safety guard system of light water reactors for a loss-of-coolant accident, a variety of large scale test were performed. Through the results, many phenomena were investigated and the predictabity of analytical codes were examined. The tests conducted were a single-vessel blowdown test, emergency core cooling test in a PWR simulation facility, spray cooling test for a BWR, large scale reflood test and a separate effect test on countercurrent flow. These test results were examined to clarify thermal-hydraulic phenomena and the effect of various test parameters and were utilized to improve predictability of the analytical codes. Some models for flow behavior in the upper core were also developed. By evaluating the effectiveness of various emergency core cooling system configurations, more effective cooling system than the current one was proposed and demonstrated. (author)

  20. Effects of ageing on the hydraulics of water wells and the influence of non-Darcy flow

    Science.gov (United States)

    Houben, Georg J.; Wachenhausen, Julia; Guevara Morel, Carlos R.

    2018-04-01

    Well ageing is mostly caused by mechanical and biogeochemical clogging processes, which affect the gravel pack, screen slots and casing. Clogging deposits increase head losses due to a constriction of the hydraulically effective area. For this study, clogging is mimicked by systematically reducing the gravel pack porosity, the screen open area and the nominal inner casing diameter. Groundwater flow velocity strongly increases close to the well, inducing inertial and turbulent flow components. Therefore, gravel pack head losses were calculated using the Forchheimer-Engelund equation, in conjunction with the Kozeny-Carman equation, which relates gravel pack porosity and hydraulic conductivity. Screen losses were assessed using the Orifice equation and turbulent casing losses with the Darcy-Weisbach equation. For the settings chosen here, a dramatic increase of head losses occurs when the clogging has reduced the effective porosity in the gravel pack by 65%, the open area of the screen by ≥98%, and the casing diameter by 50%. Since the latter two conditions are rarely reached in actual wells, the clogging of the gravel pack is the decisive parameter that controls well ageing. Regular monitoring of the well yield is therefore needed, since processes in the gravel pack are difficult to track directly. Unlike the deposits on the casing and in the screen slots, obstructions in the gravel pack are much more difficult to remove.

  1. Growth and Carcass Physical Components of Thin Tail Rams Fed on Different Levels of Rice Bran

    OpenAIRE

    Rianto, E; Lindasari, E; Purbowati, E

    2006-01-01

    This experiment was aimed to investigate the effect of rice bran supplementation on live weight gain (LWG), the proportion of carcass meat, bone and fat of Thin Tail Rams. Twelve thin tail rams, aged about 12 months, weighed 20.95 ± 1.52 kg (CV = 7.26%) were allocated into a Randomized Block Design with 2 blocks and 3 treatments. The treatments applied were levels of rice bran supplementation, i.e. Napier grass ad libitum without rice bran (T1), Napier grass ad libitum and 200 g rice bran (T2...

  2. Effect of stiffness and movement speed on selected dynamic torque characteristics of hydraulic-actuation joystick controls for heavy vehicles.

    Science.gov (United States)

    Oliver, Michele; Rogers, Robert; Rickards, Jeremy; Tingley, Maureen; Biden, Edmund

    2006-02-22

    The purpose of this work was to quantify the effects of joystick stiffness and movement speed on the dynamic torque characteristics of hydraulic-actuation joystick controls, as found in off-road vehicles, as one of the initial steps towards the development of a joystick design protocol. Using a previously developed mathematical model in which a hydraulic-actuation joystick is assumed to rotate about two axes where the rotation origin is a universal joint, the dynamic torque characteristics incurred by an operator were predicted. Utilizing a laboratory mock-up of an excavator cab environment, three actuation torque characteristics (peak torque, angular impulse and deceleration at the hard endpoint) were quantified for nine unskilled joystick operators during the use of a commonly used North American hydraulic-actuation joystick. The six different experimental conditions included combinations of three joystick stiffnesses and two movement speeds. The highest instantaneous input torque over the course of the joystick movement (not including the hard endpoint) was evaluated using the peak torque value. Angular impulse provided an indication of the sustained exposure to force. The third indicator, deceleration at the hard endpoint, was included to provide a description of impact loading on the hand as the joystick came to a sudden stop. The most important result of this work is that the dynamic torque characteristics incurred during hydraulic-actuation joystick use are substantial. While the peak torque values were not very different between the fast and slow motion conditions, the high decelerations even for slow movements observed at maximum excursion of the joystick indicate that the dynamics do matter. On the basis of deceleration at the hard endpoint and peak torque, the joystick movements that require the highest values for a combination of torque variables are the side-to-side ones. This suggests that less stiff balance and return springs should be considered for

  3. Effect of tube bank inclination on the thermal hydraulic performance of air-cooled heat exchangers

    International Nuclear Information System (INIS)

    Monheit, M.; Freim, J.

    1987-01-01

    This paper compares the experimental thermal hydraulic performance of an inclined tube bundle of staggered high finned tubes with that of the same bank in cross flow. The data are shown on a relative basis with the conventional cross-flow arrangement used as the reference layout. The results, presented as plots of heat transfer coefficient and pressure drop per row versus face velocity, are compared with other published data for bare and extended-surface tube banks. Correction factors that account for the deviation from cross-flow performance are presented. Estimated savings in plot area are shown for typical cases. Some possible cost reduction opportunities in specific fields of application are also suggested

  4. Nonlinear Dynamical Analysis of Hydraulic Turbine Governing Systems with Nonelastic Water Hammer Effect

    Directory of Open Access Journals (Sweden)

    Junyi Li

    2014-01-01

    Full Text Available A nonlinear mathematical model for hydroturbine governing system (HTGS has been proposed. All essential components of HTGS, that is, conduit system, turbine, generator, and hydraulic servo system, are considered in the model. Using the proposed model, the existence and stability of Hopf bifurcation of an example HTGS are investigated. In addition, chaotic characteristics of the system with different system parameters are studied extensively and presented in the form of bifurcation diagrams, time waveforms, phase space trajectories, Lyapunov exponent, chaotic attractors, and Poincare maps. Good correlation can be found between the model predictions and theoretical analysis. The simulation results provide a reasonable explanation for the sustained oscillation phenomenon commonly seen in operation of hydroelectric generating set.

  5. Vorticity and turbulence effects in fluid structure interaction an application to hydraulic structure design

    CERN Document Server

    Brocchini, M

    2006-01-01

    This book contains a collection of 11 research and review papers devoted to the topic of fluid-structure interaction.The subject matter is divided into chapters covering a wide spectrum of recognized areas of research, such as: wall bounded turbulence; quasi 2-D turbulence; canopy turbulence; large eddy simulation; lake hydrodynamics; hydraulic hysteresis; liquid impacts; flow induced vibrations; sloshing flows; transient pipe flow and air entrainment in dropshaft.The purpose of each chapter is to summarize the main results obtained by the individual research unit through a year-long activity on a specific issue of the above list. The main feature of the book is to bring state of the art research on fluid structure interaction to the attention of the broad international community.This book is primarily aimed at fluid mechanics scientists, but it will also be of value to postgraduate students and practitioners in the field of fluid structure interaction.

  6. EFFECT OF HYDRAULIC AND GEOMETRICAL PROPERTIES ON STEPPED CASCADE AERATION SYSTEM

    Directory of Open Access Journals (Sweden)

    VEDHACHALAM RATHINAKUMAR

    2017-03-01

    Full Text Available Stepped cascade aeration system is commonly used to aerate the water and wastewater to increase the dissolved oxygen during pre and post treatment process. In the present research, experiments were conducted to evaluate the performance of a rectangular Cascade Aeration System with varying flow rates, risers and tread by maintaining constant width of the channel using water collected from reverse osmosis plant. The experiments were carried out with four different risers such as 0.15 m, 0.18 m, 0.225 m and 0.30 m. Each rise was investigated with five different tread of 0.60 m, 0.55 m, 0.50 m, 0.45 m and 0.40 m. Comprehensive experimental investigations were carried out for different hydraulic loading rates of 0.005 to 0.035 m3/s/m2. Results obtained from the experiments reveals that increasing dimensionless discharges promotes more aeration, attains a maximum up to dimensionless discharge= 2.22 and beyond this there was a significant decrease in aeration. In addition, the increased in number of steps significantly enhances air entertainment and surface fall rate in the Stepped Cascade Aeration System. A regression equation was derived by keeping aeration efficiency as response with dimensionless discharge and oxygen saturation concentration as influencing parameters. The dimension less discharge is a function of critical depth of the rectangular channel and step height, whereas oxygen saturation concentration represents the ratio of oxygen deficit and oxygen saturation concentration. Based on the experimental results, the optimum design and/or results such as number of steps (12 numbers and hydraulic loading rate (0.025 m3/s/m2 with fixed tread width of 0.6 m were identified to achieve maximum aeration rate (0.5-0.60 in Aeration system.

  7. Effects of varying hydraulics on the calibration of eight path chordal ultrasonic meters

    International Nuclear Information System (INIS)

    Hauser, E.; Estrada, H.; Regan, J.

    2003-01-01

    Eight path transit time ultrasonic meters are being used in the US, Europe and Japan to support measurement uncertainty power uprates of nuclear power plants. Power uprates rely on the demonstration of improved power accuracy to justify a reduction in the traditional 2% margin between operating power and the power at which loss of coolant accidents and other transients have been analyzed. The flow, density and enthalpy of the feedwater are key elements in the power calculation, and the eight path ultrasonic meters measure the flow and temperature from which these elements are derived. A key element in the uncertainty analysis for these meters is an allowance for the uncertainties that the feedwater flow profiles introduce in the meters' flow calibrations. To minimize and bound this uncertainty calibration tests are performed on each eight path element to be used in an uprate application. This paper describes extensive testing of a prototype eight path meter, results of which have be used to define the sensitivity of 8 path meters to broad variations in flow profiles, both axial and transverse and to establish a methodology whereby the impact of these changes on the uncertainty of the meters can be minimized. This testing confirms the general insensitivity of 8 path chordal systems to axial and transverse fluid velocity profiles. An 8 path chordal system provides a quantitative measurement of the flatness of the axial profile, which allows a quantitative assessment of the differences in hydraulic profile seen by a meter in a plant versus the hydraulic profile seen by that same meter in the calibration lab. Since the sensitivity of the meter's calibration can be established as a function of profile flatness in the lab through parametric testing, the profile flatness in the plant can be used to confirm or to adapt as necessary the calibration coefficient measured in the lab for use in the plant. (author)

  8. Hydraulic properties and scale effects investigation in regional rock aquifers, south-western Quebec, Canada

    Science.gov (United States)

    Nastev, M.; Savard, M. M.; Lapcevic, P.; Lefebvre, R.; Martel, R.

    This paper reports on the characterization of hydraulic properties of regional rock aquifers carried out within a groundwater resources assessment project in the St. Lawrence Lowlands of south-western Quebec. To understand the aquifer behavior at both the fracture level and at field scale, hydraulic investigations were carried out using various aquifer tests. The groundwater flow at the local scale is controlled mostly by the fracture system. Results of the constant-head injection tests show a weak decreasing trend of hydraulic conductivity with depth indicating that a major part of the groundwater flow occurs in the first meters of the rock sequence. At the regional scale, the equivalent porous media approach is applicable. The hydraulic conductivity measurements were correlated to the scale of the aquifer tests expressed with the investigated aquifer volume. A simple interpolation procedure for the hydraulic conductivity field was developed based on the distance between field measurements and the tested aquifer volumes. The regional distribution of the hydraulic conductivity for the major fractured aquifer units indicates that dolostone is the most permeable whereas sandstone and crystalline rocks are the least permeable units. Este artículo trata de la caracterización de las propiedades hidráulicas en acuíferos regionales rocosos, la cual se llevó a cabo dentro del proyecto de evaluación de los recursos de agua subterránea en St. Lawrence Lowlands al suroeste de Quebec. Para entender el comportamiento del acuífero tanto a nivel de fractura como a escala del campo, se ejecutaron investigaciones hidráulicas usando varias pruebas de acuífero. El flujo del agua subterránea a escala local está controlado principalmente por el sistema de fracturas. Los resultados de las pruebas de inyección con cabeza constante muestran una tendencia decreciente débil de la conductividad hidráulica con la profundidad, indicando que la mayor parte del flujo de agua

  9. Ultrasonic sludge disintegration for enhanced methane production in anaerobic digestion: effects of sludge hydrolysis efficiency and hydraulic retention time.

    Science.gov (United States)

    Kim, Dong-Jin; Lee, Jonghak

    2012-01-01

    Hydrolysis of waste activated sludge (WAS) has been regarded as the rate limiting step of anaerobic sludge digestion. Therefore, in this study, the effect of ultrasound and hydraulic residence time during sludge hydrolysis was investigated with the goal of enhancing methane production from anaerobic digestion (AD). WAS was ultrasonically disintegrated for hydrolysis, and it was semi-continuously fed to an anaerobic digesters at various hydraulic retention times (HRTs). The results of these experiments showed that the solids and chemical oxygen demand (COD) removal efficiencies when using ultrasonically disintegrated sludge were higher during AD than the control sludge. The longer the HRT, the higher the removal efficiencies of solids and COD, while methane production increased with lower HRT. Sludge with 30% hydrolysis produced 7 × more methane production than the control sludge. The highest methane yields were 0.350 m(3)/kg volatile solids (VS)(add) and 0.301 m(3)/kg COD(con) for 16 and 30% hydrolyzed sludge, respectively. In addition, we found that excess ultrasound irradiation may inhibit AD since the 50% hydrolyzed sludge produced lower methane yields than 16 and 30% hydrolyzed sludge.

  10. Measurement of fluid film thickness on the valve plate in oil hydraulic axial piston pumps (I): bearing pad effects

    International Nuclear Information System (INIS)

    Kim, Jong Ki; Jung, Jae Youn

    2003-01-01

    The tribological mechanism between the valve plate and the cylinder block in oil hydraulic axial piston pumps plays an important role on high power density. In this study, the fluid film thickness between the valve plate and the cylinder block was measured with discharge pressure and rotational speed by use of a gap sensor, and a slip ring system in the operating period. To investigate the effect of the valve plate shapes, we designed two valve plates with different shapes: the first valve plate was without a bearing pad, while the second valve plate had a bearing pad. It was found that both valve plates behaved differently with respect to the fluid film thickness characteristics. The leakage flow rates and the shaft torque were also experimented in order to clarify the performance difference between the valve plate without a bearing pad and the valve plate with a bearing pad. From the results of this study, we found out that in the oil hydraulic axial piston pumps, the valve plate with a bearing pad showed better film thickness contours than the valve plate without a bearing pad

  11. Methodology for assessing the safety of Hydrogen Systems: HyRAM 1.1 technical reference manual

    Energy Technology Data Exchange (ETDEWEB)

    Groth, Katrina; Hecht, Ethan; Reynolds, John Thomas; Blaylock, Myra L.; Erin E. Carrier

    2017-03-01

    The HyRAM software toolkit provides a basis for conducting quantitative risk assessment and consequence modeling for hydrogen infrastructure and transportation systems. HyRAM is designed to facilitate the use of state-of-the-art science and engineering models to conduct robust, repeatable assessments of hydrogen safety, hazards, and risk. HyRAM is envisioned as a unifying platform combining validated, analytical models of hydrogen behavior, a stan- dardized, transparent QRA approach, and engineering models and generic data for hydrogen installations. HyRAM is being developed at Sandia National Laboratories for the U. S. De- partment of Energy to increase access to technical data about hydrogen safety and to enable the use of that data to support development and revision of national and international codes and standards. This document provides a description of the methodology and models contained in the HyRAM version 1.1. HyRAM 1.1 includes generic probabilities for hydrogen equipment fail- ures, probabilistic models for the impact of heat flux on humans and structures, and computa- tionally and experimentally validated analytical and first order models of hydrogen release and flame physics. HyRAM 1.1 integrates deterministic and probabilistic models for quantifying accident scenarios, predicting physical effects, and characterizing hydrogen hazards (thermal effects from jet fires, overpressure effects from deflagrations), and assessing impact on people and structures. HyRAM is a prototype software in active development and thus the models and data may change. This report will be updated at appropriate developmental intervals.

  12. Reversible harmless interruption of testicular blood supply in the ram

    International Nuclear Information System (INIS)

    van Vliet, J.; De Ruiter-Bootsma, A.L.; Oei, Y.H.; Hoekstra, A.; De Rooij, D.G.; Wensing, C.J.

    1987-01-01

    An effective method of interrupting testicular blood flow temporarily and repeatedly in the ram has been developed. Blockade of flow has been achieved mechanically by an inflatable occluder placed around the testicular artery at the level of the spermatic cord. The effect of the blockade on total testicular blood supply was investigated using Doppler flowmetry and a percutaneous Xenon-133 injection method. With both approaches, the blood flow changes after inflation or deflation of the occluders could be estimated satisfactorily. A substantial decrease of testicular blood flow was achieved in eight of the 10 testes with inflated occluders. However, there were indications that in the remaining two testes blockade of the arterial flow was not complete. After deflation of the occluders, blood flow was restored rapidly and completely in all testes. Macro- and microscopic examinations revealed no long-term damage to the testis after blood flow interruptions lasting 30 or 60 minutes

  13. Ramón Cote Baraibar

    Directory of Open Access Journals (Sweden)

    Juan Gustavo Cobo Borda

    2005-05-01

    Full Text Available Hijo de poeta, como María Mercedes Carranza y Santiago Mutis, Ramón Cote nació en Cúcuta el 19 de mayo de 1963- Su primer libro fue publicado en 1984 por ediciones Arnao, de Madrid, donde se graduó en historia del arte en la Universidad Complutense. Al instalarse en Colombia, se dedicó a la publicidad. Ha publicado ensayos sobre poesía colombiana en revistas como ínsula, y en 1992, con el título de  |Diez de ultramar publicó una muestra de joven poesía latinoamericana que abarcaba nombres como José Luis Rivas, Coral Bracho, Raúl Zurita, Fabio Morabito, Yolanda Pantin y Eduardo Chirinos. Entre la nueva poesía colombiana, su voz es una de las más reconocibles. Vale la pena, entonces, repasar la totalidad de su trayectoria.

  14. Radiation Level Changes at RAM Package Surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Opperman, Erich [Washington Savannah River Company; Hawk, Mark B [ORNL; Kapoor, Ashok [U.S. Department of Energy, Office of Packaging and Transportation; Natali, Ronald [R. B. Natali Consulting, Inc.

    2010-01-01

    This paper will explore design considerations required to meet the regulations that limit radiation level variations at external surfaces of radioactive material (RAM) packages. The radiation level requirements at package surfaces (e.g. TS-R-1 paragraphs 531 and 646) invoke not only maximum radiation levels, but also strict limits on the allowable increase in the radiation level during transport. This paper will explore the regulatory requirements by quantifying the amount of near surface movement and/or payload shifting that results in a 20% increase in the radiation level at the package surface. Typical IP-2, IP-3, Type A and Type B packaging and source geometries will be illustrated. Variations in surface radiation levels are typically the result of changes in the geometry of the surface due to an impact, puncture or crush event, or shifting and settling of radioactive contents.

  15. Performance of growing Yankasa rams Fed graded levels of ...

    African Journals Online (AJOL)

    A feeding trial which lasted eight (8) weeks was carried out to determine the intake and nutrient digestibility by growing Yankasa rams fed graded levels of Tamarindus indica leaves. Twelve Yankasa rams with average liveweight of 17.40kg were randomly allocated to three treatments of four replicates in a Randomized ...

  16. Seasonal variation in semen quality of Dorper rams using different ...

    African Journals Online (AJOL)

    Seasonal variation in semen quality of Dorper rams using different collection ... libitum throughout the trial, and all rams being fed a 2.5 kg maintenance diet per day. ... quality collected by the AV versus the EE collection method was recorded.

  17. Design and verification of a self-timed RAM

    DEFF Research Database (Denmark)

    Nielsen, Lars Skovby; Staunstrup, Jørgen

    1995-01-01

    This paper describes a self-timed static RAM. A single bit RAM is described in the design language SYNCHRONIZED TRANSITIONS and using the verification tools supporting this language, it is shown that the design is speed-independent. Furthermore, a transistor level implementation of the design...

  18. Evaluation of semen extenders for short-term storage of ram semen at 4° C

    Science.gov (United States)

    Preliminary studies found that progressive motility of ram sperm declined ~75% when stored at 4° C for 24 h, and continued to decline over time when using extenders supplemented with 5% egg yolk. The current study evaluated the effects of different combinations of extenders, ethylene glycol (EG), eg...

  19. Recurrent 3-day cycles of water deprivation for over a month depress mating behaviour but not semen characteristics of adult rams.

    Science.gov (United States)

    Khnissi, S; Lassoued, N; Rekik, M; Ben Salem, H

    2016-02-01

    This study aimed to investigate the effect of water deprivation (WD) on reproductive traits of rams. Ten mature rams were used and allocated to two groups balanced for body weight. Control (C) rams had free access to drinking water, while water-restricted rams (WD) were deprived from water for 3 consecutive days and early on the morning of day 4, they had ad libitum access to water for 24 h, similar to C animals. The experiment lasted 32 days, that is eight 4-day cycles of water deprivation and subsequent watering. Feed and water intake were significantly affected by water deprivation; in comparison with C rams, WD rams reduced their feed intake by 18%. During the watering day of the deprivation cycle, WD rams consumed more water than C rams on the same day (11.8 (SD = 3.37) and 8.4 (SD = 1.92) l respectively; p water deprivation. However, testosterone levels were lowered as a result of water deprivation and average values were 10.9 and 6.2 (SEM 1.23) ng/ml for C and WD rams respectively (p cycles 5 and 8 of water deprivation. Several mating behaviour traits were modified as a result of water deprivation. When compared to controls, WD rams had a more prolonged time to first mount attempt (p Water deprivation may have practical implications reducing the libido and therefore the serving capacity of rams under field conditions. Journal of Animal Physiology and Animal Nutrition © 2015 Blackwell Verlag GmbH.

  20. De las Greguerias: Ah, Ramón, Ramón...

    Directory of Open Access Journals (Sweden)

    Luis Navarro

    1964-11-01

    Full Text Available Yo me pregunto qué hará a hora Ramón detrás del biombo irreversible de la muerte. Me lo figuro de espaldas a la pared, con el rostro de simulada contrición y en las manos un blok sobre el que escribe eternamente, renglón tras renglón, las palabras de castigo: "No volveré a hacer burla de las cosas trascendentes". Lope, Quevedo, Goya, Solana y el Marqués de Bradomin, liberados ya de sus respectivos sambenitos en el tiempo metafísico de los muertos, intercederán por el castigado colocando en la terrible Balanza de los Cielos, a favor de Ramón, los libros ejemplares en que este habla de aquellos. Dirán al unísono: todos hablaron de mí, pero ninguno me conoció; solo Ramón.

  1. Hydraulic Permeability of Resorcinol-Formaldehyde Ion-Exchange Resin - Effects of Oxygen Uptake and Radiation

    International Nuclear Information System (INIS)

    Taylor, Paul Allen

    2009-01-01

    An ion-exchange process, using spherical resorcinol-formaldehyde (RF) resin is the baseline process for removing cesium from the dissolved salt solution in the high-level waste tanks at the U.S. Department of Energy's (DOE) Hanford site in Washington State. The RF resin is also being evaluated for use in the proposed Small Column Ion Exchange (SCIX) system, which is an alternative treatment option at DOE's Savannah River Site (SRS)in South Carolina. Testing at ORNL will determine the impact of radiation exposure and oxygen uptake by the RF resin on the hydraulic permeability of the resin. Samples of the resin will be removed periodically to measure physical properties (bead size and compressibility) and cesium capacity. The proposed full-scale treatment system at Hanford, the Waste Treatment Plant (WTP), will use an ion-exchange column containing nominally 680 gal of resin, which will treat 30 gpm of waste solution. The ion-exchange column is designed for a typical pressure drop of 6 psig, with a maximum of 9.7 psig. The lab-scale column is 3-in. clear PVC pipe and is prototypic of the proposed Hanford column. The fluid velocity in the lab-scale test will be much higher than for the full-scale column, in order to generate the maximum pressure drop expected in that column (9.7 psig). The frictional drag from this high velocity will produce similar forces on the resin in the lab-scale column as would be expected at the bottom of the full-scale column. The chemical changes in the resin caused by radiation exposure and oxygen uptake are expected to cause physical changes in the resin that could reduce the bed porosity and reduce the hydraulic permeability of the resin bed. These changes will be monitored by measuring the pressure drop through the lab-scale column and by measuring the physical properties of samples of the resin. The test loop with the lab-scale column is currently being fabricated, and operation will start by late May. Testing will be completed by the

  2. The Two Populations of Kisspeptin Neurons Are Involved in the Ram-Induced LH Pulsatile Secretion and LH Surge in Anestrous Ewes.

    Science.gov (United States)

    Fabre-Nys, Claude; Cognié, Juliette; Dufourny, Laurence; Ghenim, Meriem; Martinet, Stephanie; Lasserre, Olivier; Lomet, Didier; Millar, Robert P; Ohkura, Satoshi; Suetomi, Yuta

    2017-11-01

    Exposure to a ram during spring stimulates luteinizing hormone (LH) secretion and can induce ovulation in sexually quiescent ewes ("ram effect"). Kisspeptin (Kiss) present in the arcuate nucleus (ARC) and the preoptic area (POA) is a potent stimulators of LH secretion. Our aim was to investigate whether Kiss neurons mediate the increase in LH secretion during the ram effect. With double immunofluorescent detection, we identified Kiss neurons (Kiss IR) activated (Fos IR) by exposure to a ram for 2 hours (M2) or 12 hours (M12) or to ewes for 2 hours (C). The density of cells Kiss + Fos IR and the proportion of Kiss IR cells that were also Fos IR cells were higher in M2 and M12 than in C in ARC (P populations of Kiss neurons are involved in the ram-induced pulsatile LH secretion and in the LH surge. Copyright © 2017 Endocrine Society.

  3. First Exploratory Study on the Ageing of Rammed Earth Material

    Science.gov (United States)

    Bui, Quoc-Bao; Morel, Jean-Claude

    2014-01-01

    Rammed earth (RE) is attracting renewed interest throughout the world thanks to its “green” characteristics in the context of sustainable building. In this study, the ageing effects on RE material are studied on the walls which have been constructed and exposed for 22 years to natural weathering. First, mechanical characteristics of the “old” walls were determined by two approaches: in-situ dynamic measurements on the walls; laboratory tests on specimens which had been cut from the walls. Then, the walls’ soil was recycled and reused for manufacturing of new specimens which represented the initial state. Comparison between the compressive strength, the Young modulus of the walls after 22 years on site and that of the initial state enables to assess the ageing of the studied walls. PMID:28787920

  4. Effects of transmembrane hydraulic pressure on performance of forward osmosis membranes.

    Science.gov (United States)

    Coday, Bryan D; Heil, Dean M; Xu, Pei; Cath, Tzahi Y

    2013-03-05

    Forward osmosis (FO) is an emerging membrane separation process that continues to be tested and implemented in various industrial water and wastewater treatment applications. The growing interests in the technology have prompted laboratories and manufacturers to adopt standard testing methods to ensure accurate comparison of membrane performance under laboratory-controlled conditions; however, standardized methods might not capture specific operating conditions unique to industrial applications. Experiments with cellulose triacetate (CTA) and polyamide thin-film composite (TFC) FO membranes demonstrated that hydraulic transmembrane pressure (TMP), common in industrial operation of FO membrane elements, could affect membrane performance. Experiments were conducted with three FO membranes and with increasing TMP up to a maximum of 50 psi (3.45 bar). The feed solution was a mixture of salts and the draw solution was either a NaCl solution or concentrated seawater at similar osmotic pressure. Results revealed that TMP minimally affected water flux, reverse salt flux (RSF), and solute rejection of the CTA membrane. However, water flux through TFC membranes might slightly increase with increasing TMP, and RSF substantially declines with increasing TMP. It was observed that rejection of feed constituents was influenced by TMP and RSF.

  5. Use of LANDSAT images of vegetation cover to estimate effective hydraulic properties of soils

    Science.gov (United States)

    Eagleson, Peter S.; Jasinski, Michael F.

    1988-01-01

    The estimation of the spatially variable surface moisture and heat fluxes of natural, semivegetated landscapes is difficult due to the highly random nature of the vegetation (e.g., plant species, density, and stress) and the soil (e.g., moisture content, and soil hydraulic conductivity). The solution to that problem lies, in part, in the use of satellite remotely sensed data, and in the preparation of those data in terms of the physical properties of the plant and soil. The work was focused on the development and testing of a stochastic geometric canopy-soil reflectance model, which can be applied to the physically-based interpretation of LANDSAT images. The model conceptualizes the landscape as a stochastic surface with bulk plant and soil reflective properties. The model is particularly suited for regional scale investigations where the quantification of the bulk landscape properties, such as fractional vegetation cover, is important on a pixel by pixel basis. A summary of the theoretical analysis and the preliminary testing of the model with actual aerial radiometric data is provided.

  6. Some considerations on the effect of xylem embolism in conductivity Hydraulic plant

    International Nuclear Information System (INIS)

    Socorro, Alfredo

    2008-01-01

    From the physical characteristics of the elements that make up the xylem tissue in the stems of plants, a hypotheses is proposed to obtain a mathematical expression that defines Water flows through these conductors systems, depending on the potential difference water between the top and bottom of the stem. It raises an expression for the number of air bubbles formed from the imperfections (pores) in the walls of the tracheids forming xylem vessels and high stresses to which it is subjected in this transpiration high activity situations. This leads to an equation for conductivity hydraulic function of water potential in the presence of xylem embolism. using data from the literature and estimated values ​​simulated values ​​is performed stream and the percentage loss of conductivity. These results are compared with evidence and practice is discussed on the basis of physiological mechanisms relating to vulnerability of plants to xylem cavitation. It analyzes how this situation can be be corrected, also valued as this phenomenon affects situations of water stress

  7. NGC 3312: A victim of ram pressure sweeping

    International Nuclear Information System (INIS)

    Mcmahon, P.M.; Richter, O.G.; Vangorkom, J.H.; Ferguson, H.C.

    1990-01-01

    Researchers are undertaking a volume limited survey of the Hydra I cluster in neutral hydrogen using the National Radio Astronomy Observatory's Very Large Array (VLA). The main purpose is to study the effects of a dense environment on the gaseous component of the galaxies. Observational evidence has been accumulating recently that ram pressure sweeping does occur in the centers of clusters, but it is possible that tidal interactions play a role as well. Results of high resolution HI imaging of NGC 3312, the large peculiar spiral near the cluster center are presented. Hydra I (= A1060) is the nearest rich cluster beyond Virgo and, as such, presents a unique opportunity to do a complete survey of a cluster. It is similar to the Virgo cluster in many of its general physical characteristics, such as size, x ray luminosity, velocity dispersion, and galaxy content (high spiral fraction). However, Hydra I appears to be more regular and relaxed. This is evident in the x ray distribution in its central region, which is radially symmetric and centered on the dominant galaxy, NGC 3311, a cD-like elliptical. The observed x ray luminosity implies a central gas density of 4.5 x 10 to the 3rd power cm(-3). Gallagher (1978) argued from optical images of NGC 3312 that this galaxy might be an ideal candidate to directly study effects of the ram pressure process; it might currently be undergoing stripping of its interstellar medium. The researchers' data are consistent with this suggestion, but other origins of the peculiar appearance cannot yet be ruled out

  8. The examination of the effects of the flow baffle on the thermal hydraulic performance of IHX shell side

    International Nuclear Information System (INIS)

    Kim, W. K.; Sim, Y. S.; Kim, S. O.; Baek, B. J.

    2002-01-01

    The effects of the flow baffle on the thermal hydraulic performance of IHX shell side has been examined using ASTEEPL, 2DHX code for the variation of baffle distance, baffle cut and baffle flow hole design data. When KALIMER design data were selected as a base for the study, a shell baffle structures does not influence on a total heat transfer rate and it is better to reduce baffle distance rather than baffle flow hole size from the view of pressure loss in the IHX. Radial thermal imbalance between tubes was reduced to 6 .deg. C when the number of baffle is beyond 13. And thermal imbalance decreased also when flow hole size decreases. If flow hole clogs perfectly, thermal imbalance can be reduced up to 2 .deg. C

  9. Project description: ORNL PWR blowdown heat transfer separate-effects program, Thermal-Hydraulic Test Facility (THTF)

    International Nuclear Information System (INIS)

    1976-02-01

    The ORNL Pressurized-Water Reactor Blowdown Heat Transfer (PWR-BDHT) Program is an experimental separate-effects study of the relations among the principal variables that can alter the rate of blowdown, the presence of flow reversal and rereversal, time delay to critical heat flux, the rate at which dryout progresses, and similar time-related functions that are important to LOCA analysis. Primary test results will be obtained from the Thermal-Hydraulic Test Facility (THTF), a large nonnuclear pressurized-water loop that incorporates a 49-rod electrically heated bundle. Supporting experiments will be carried out in two additional test loops - the Forced Convection Test Facility (FCTF), a small high-pressure facility in which single heater rods can be tested in annular geometry; and an air-water loop which is used to evaluate two-phase flow-measuring instrumentation

  10. Single failure effects of reactor coolant system large bore hydraulic snubbers for Korean Standard Nuclear Power Plant

    International Nuclear Information System (INIS)

    Choi, T.S.; Park, S.H.; Sung, K.K.; Kim, T.W.; Jheon, J.H.

    1996-01-01

    A potential snubber single failure is one of the safety significances identified in General Safety Issue 113 for Large Bore Hydraulic Snubber (LBHS) dynamic qualification. This paper investigates dynamic structural effects of single failures of the steam generator and reactor coolant pump snubbers in Korean Standard Nuclear Power Plant by performing the time history dynamic analyses for the reactor coolant system under seismic and postulated pipe break events. The seismic input motions considered are the synthesized ground time histories conforming to SRP 3.7.1, and he postulated pipe break input loadings result from steam generator main seam line and feedwater line pipe breaks which govern pipe breaks remaining after applying LBB to the main coolant line and primary side ranch lines equal to and greater than 12 inch nominal pipe size

  11. Effect of Adsorbed Protein on the Hydraulic Permeability, Membrane and Streaming Potential Values Measured across a Microporous Membrane

    DEFF Research Database (Denmark)

    Benavente, Juana; Jonsson, Gunnar Eigil

    1998-01-01

    permeability decreases strongly when the pH decreases, having its minimum value at the isoelectric point of the protein; the apparent zeta potential values are also dependent on both pH and salt concentration. Differences in the streaming potential coefficient determined for two membranes fouled under......The effect of the adsorption of a protein, bovine serum albumin (BSA), on the membrane potential, flux reduction and streaming potential measured across a microporous polysulphone membrane with different NaCl solutions and pH values is studied. From electrokinetic phenomena, information about...... the electrical properties of the membrane (fixed charge concentration and ionic transport numbers) or the membrane/solute interactions (streaming and zeta potentials) can be obtained. The influence of pH and ionic strength on volume flux and streaming potential values is considered. Results show that hydraulic...

  12. Effectiveness of Sealed Double-Ring Infiltrometers trademark and effects of changes in atmospheric pressure on hydraulic conductivity

    International Nuclear Information System (INIS)

    McMullin, S.R.

    1994-01-01

    The Savannah River Site is currently evaluating some 40 hazardous and radioactive-waste sites for remediation. Among the remedial alternatives considered is closure using a kaolin clay cap. The hydraulic conductivity suggested by the US Environmental Protection Agency is 1.0 x 10 -7 cm/sec. One instrument to measure this value is the Sealed Double-Ring Infiltrometer trademark (SDRI). Six SDRI were recently installed on a kaolin test cap. Test results demonstrated uniform performance of these instruments. However, the test data showed as much as an order of magnitude of variation over time. This variation is attributed to both internal structural heterogeneity and variable external boundary conditions. The internal heterogeneity is caused by construction variability within a specified range of moisture and density. The external influences considered are temperature and barometric pressure. Temperature was discharged as a source of heterogeneity because of a lack of correlation with test data and a negligible impact from the range of variability. However, a direct correlation was found between changes in barometric pressure and hydraulic conductivity. This correlation is most pronounced when pressure changes occur over a short period of time. Additionally, this correlation is related to a single soil layer. When the wetting front passes into a more porous foundation layer, the correlation with pressure changes disappears. Conclusions are that the SDRI performs adequately, with good repeatability of results. The duration of test is critical to assure a statistically valid data set. Data spikes resulting from pressure changes should be identified, and professional judgment used to determine the representative hydraulic conductivity. Further evaluation is recommended to determine the impact of pressure change on the actual hydraulic conductivity

  13. Hydraulically actuated artificial muscles

    Science.gov (United States)

    Meller, M. A.; Tiwari, R.; Wajcs, K. B.; Moses, C.; Reveles, I.; Garcia, E.

    2012-04-01

    Hydraulic Artificial Muscles (HAMs) consisting of a polymer tube constrained by a nylon mesh are presented in this paper. Despite the actuation mechanism being similar to its popular counterpart, which are pneumatically actuated (PAM), HAMs have not been studied in depth. HAMs offer the advantage of compliance, large force to weight ratio, low maintenance, and low cost over traditional hydraulic cylinders. Muscle characterization for isometric and isobaric tests are discussed and compared to PAMs. A model incorporating the effect of mesh angle and friction have also been developed. In addition, differential swelling of the muscle on actuation has also been included in the model. An application of lab fabricated HAMs for a meso-scale robotic system is also presented.

  14. Effect of dry density and temperature on the hydraulic conductivity of domestic compacted bentonite as a buffer material in the high level waste repository

    International Nuclear Information System (INIS)

    Cho, Won Jin; Chun, Kwan Sik; Lee, Jae Owan

    1999-02-01

    This study is intended to investigate the effect of dry density and temperature on the hydraulic conductivity of domestic calcium bentonite. The dry densities of bentonite are 1.4 Mg/m 3 , 1.6 Mg/m 3 and 1.6 Mg/m, and the temperatures are in the range of 20 dg C to 150 dg C. The hydraulic conductivities of compacted bentonite with dry densities higher than 1.4 Mg/m 3 are lower than 10 -1 1 m/s, and are low enough to inhibit the radionuclide release by advection through the buffer. The hydraulic conductivities at the temperature of 150 dg C increase up to about 1 order higher than those at 20 dg C. (author). 28 refs., 5 tabs., 20 figs

  15. Effects of Hydraulic Retention Time on the Performance of a Membrane Bioreactor Treating Municipal Wastewater

    Directory of Open Access Journals (Sweden)

    Hadi Falahati

    2017-09-01

    Full Text Available There is an increasing demand for effluents of higher quality from wastewater treatment plants due to the more stringent quality standards as well as the increasing pressure on water resources worldwide, which calls for effluent recycle and reuse. Membrane bioreactors (MBRs have been recently gaining rapid popularity as a promising technology for wastewater treatment. In order to improve the quality of the effluent from Shiraz wastewater treatment plant, an on-site pilot-scale membrane bioreactor was operated for 9 months. The pilot plant built at Shiraz wastewater treatment plant consisted of an aerobic reactor and a membrane compartment containing one submerged hollow fiber membrane module. In this study, eleven different aerobic hydraulic retention times (HRT ranging from 2 to 12 hours were tested to determine the membrane capacity and to investigate the performance of the system in removing total ammonia nitrogen, organic matter, total suspended solids, and turbidity.The system recorded a perfectly stable removal efficiency over the whole experimental period, except for the 2-hour aerobic HRT, so that its COD and BOD reductions exceeded 95% and 99%, respectively. Moreover, the system achieved complete nitrification in a stable manner during the whole study period, except for the 2-hour aerobic operation period. TSS concentration was almost zero and turbidity was less than 1 NTU. Membrane capacity measurements showed an average flux of 5.5 Lm-2h-1 with a mean trans-membrane pressure difference of 30 kPa. Results showed that the MBR outperformed the conventional sewage treatment processes. Additionally, it was not affected by aerobic HRT changes (12, 10, 8, 6, 4, and 3h. Based on the effluent qulity, teh system may be recommended for application toward water reuse in industrial and agricultural settings

  16. Hydraulic evaluation of the groundwater conditions at Finnsjoen. The effects on dilution in a domestic well

    International Nuclear Information System (INIS)

    Axelsson, C.L.; Bystroem, J.; Eriksson, Aa.; Holmen, J.; Haitjema, H.M.

    1991-09-01

    The Swedish Nuclear Fuel and Waste Management Company (SKB) is presently performing a safety analysis study, SKB 91, for a final repository for spent nuclear fuel. The study is carried out for a generic repository located to the Finnsjoen area, which is one of SKBs oldest study-areas. An important part of the safety analysis is the dose calculations. Radionuclides can be transported to the biosphere via the sea, a lake, and via extraction of groundwater from drilled or dug wells. Thus, an important scenario to study is the dilution of radionuclides in a domestic well drilled in the future close to the repository. The present study is discussing; * Localization, drilling and construction of wells. * Specific capacities and chloride content of the rock mass and wells found in the Finnsjoe are. * Risk areas for future drilled wells. * Dilution in future wells drilled in fracture zones or in the hard rock in the vicinity of the repository. The evaluations show that a well pumping 6 m 3 /day, located in a fracture zone or in the rock mass, has no influence on the local groundwater flow system except for the very vicinity of the well. Consequently, a well may be drilled in the hard rock without any risk of pumping groundwater that has passed the repository. Wells may also be located anywhere in fracture zones, except for in the very discharge area, without any risk of getting groundwater affected by the repository. Modelling indicate that a well drilled in the discharge area for contaminated groundwater, may collect all groundwater from the repository. However, this is based on assumptions of homogeneous continuous fracture zones with a high hydraulic conductivity compared to the rock mass, which will give rise to a concentrated discharge area. (44 refs., 31 figs., 6 tabs.) (au)

  17. Effects of Volute Design and Number of Impeller Blades on Lateral Impeller Forces and Hydraulic Performance

    Directory of Open Access Journals (Sweden)

    Daniel O. Baun

    2003-01-01

    Full Text Available A comparison is made between the characteristics of the measured lateral impeller forces and the hydraulic performances of a four- and a five-vane impeller, each operating in a spiral volute, a concentric volute, and a double volute. The pump's rotor was supported in magnetic bearings. In addition to supporting and controlling the rotor motion, the magnetic bearings also served as active load cells and were used to measure the impeller forces acting on the pump's rotor. The lateral impeller force characteristics, as a function of a normalized flow coefficient, were virtually identical in the four- and five-vane impellers in each respective volute type. The measured impeller forces for each volute type were compared with correlations in the literature. The measured forces from the double volute configurations agreed with the forces from a correlation model over the full flow range. Single volute configurations compared well with the predictions of a published correlation at high flow rates, ϕ/ϕn>0.5. Concentric volute configurations compared well with a published correlation at low flow rates, ϕ/ϕn<0.4. The head-versus-flow characteristics of the four-vane impeller in each volute type were stable over a greater flow range than the corresponding characteristics of the five-vane impeller. At higher flow rates in the stable region of the head's characteristic curves near the best efficiency point, the five-vane impeller produced higher head than did the four-vane impeller in each volute type.

  18. Effects of hydraulic frac fluids and formation waters on groundwater microbial communities

    Science.gov (United States)

    Krueger, Martin; Jimenez, Nuria

    2017-04-01

    Shale gas is being considered as a complementary energy resource to other fossil fuels. Its exploitation requires using advanced drilling techniques and hydraulic stimulation (fracking). During fracking operations, large amounts of fluids (fresh water, proppants and chemicals) are injected at high pressures into the formations, to create fractures and fissures, and thus to release gas from the source rock into the wellbore. The injected fluid partly remains in the formation, while up to 40% flows back to the surface, together with reservoir waters, sometimes containing dissolved hydrocarbons, high salt concentrations, etc. The aim of our study was to investigate the potential impacts of frac or geogenic chemicals, frac fluid, formation water or flowback on groudnwater microbial communities. Laboratory experiments under in situ conditions (i.e. at in situ temperature, high pressure) were conducted using groundwater samples from three different locations. Series of microcosms containing R2 broth medium or groundwater spiked with either single frac chemicals (including biocides), frac fluids, artificial reservoir water, NaCl, or different mixtures of reservoir water and frac fluid (to simulate flowback) were incubated in the dark. Controls included non-amended and non-inoculated microcosms. Classical microbiological methods and molecular analyses were used to assess changes in the microbial abundance, community structure and function in response to the different treatments. Microbial communities were quite halotolerant and their growth benefited from low concentrations of reservoir waters or salt, but they were negatively affected by higher concentrations of formation waters, salt, biocides or frac fluids. Changes on the microbial community structure could be detected by T-RFLP. Single frac components like guar gum or choline chloride were used as substrates, while others like triethanolamine or light oil distillate hydrogenated prevented microbial growth in

  19. PTA-1 computer program for treating pressure transients in hydraulic networks including the effect of pipe plasticity

    International Nuclear Information System (INIS)

    Youngdahl, C.K.; Kot, C.A.

    1977-01-01

    Pressure pulses in the intermediate sodium system of a liquid-metal-cooled fast breeder reactor, such as may originate from a sodium/water reaction in a steam generator, are propagated through the complex sodium piping network to system components such as the pump and intermediate heat exchanger. To assess the effects of such pulses on continued reliable operation of these components and to contribute to system designs which result in the mitigation of these effects, Pressure Transient Analysis (PTA) computer codes are being developed for accurately computing the transmission of pressure pulses through a complicated fluid transport system, consisting of piping, fittings and junctions, and components. PTA-1 provides an extension of the well-accepted and verified fluid hammer formulation for computing hydraulic transients in elastic or rigid piping systems to include plastic deformation effects. The accuracy of the modeling of pipe plasticity effects on transient propagation has been validated using results from two sets of Stanford Research Institute experiments. Validation of PTA-1 using the latter set of experiments is described briefly. The comparisons of PTA-1 computations with experiments show that (1) elastic-plastic deformation of LMFBR-type piping can have a significant qualitative and quantitative effect on pressure pulse propagation, even in simple systems; (2) classical fluid-hammer theory gives erroneous results when applied to situations where piping deforms plastically; and (3) the computational model incorporated in PTA-1 for predicting plastic deformation and its effect on transient propagation is accurate

  20. A simple parameterization of aerosol emissions in RAMS

    Science.gov (United States)

    Letcher, Theodore

    Throughout the past decade, a high degree of attention has been focused on determining the microphysical impact of anthropogenically enhanced concentrations of Cloud Condensation Nuclei (CCN) on orographic snowfall in the mountains of the western United States. This area has garnered a lot of attention due to the implications this effect may have on local water resource distribution within the Region. Recent advances in computing power and the development of highly advanced microphysical schemes within numerical models have provided an estimation of the sensitivity that orographic snowfall has to changes in atmospheric CCN concentrations. However, what is still lacking is a coupling between these advanced microphysical schemes and a real-world representation of CCN sources. Previously, an attempt to representation the heterogeneous evolution of aerosol was made by coupling three-dimensional aerosol output from the WRF Chemistry model to the Colorado State University (CSU) Regional Atmospheric Modeling System (RAMS) (Ward et al. 2011). The biggest problem associated with this scheme was the computational expense. In fact, the computational expense associated with this scheme was so high, that it was prohibitive for simulations with fine enough resolution to accurately represent microphysical processes. To improve upon this method, a new parameterization for aerosol emission was developed in such a way that it was fully contained within RAMS. Several assumptions went into generating a computationally efficient aerosol emissions parameterization in RAMS. The most notable assumption was the decision to neglect the chemical processes in formed in the formation of Secondary Aerosol (SA), and instead treat SA as primary aerosol via short-term WRF-CHEM simulations. While, SA makes up a substantial portion of the total aerosol burden (much of which is made up of organic material), the representation of this process is highly complex and highly expensive within a numerical

  1. Effects of grade control structures on fish passage, biological assemblages, and hydraulic environments in western Iowa streams: a multidisciplinary review

    Science.gov (United States)

    Thomas, J.T.; Culler, M.E.; Dermisis, D.C.; Pierce, Clay; Papanicolaou, A.N.; Stewart, T.W.; Larson, C.J.

    2011-01-01

    Land use changes and channelization of streams in the deep loess region of western Iowa have led to stream channel incision, altered flow regimes, increased sediment inputs, decreased habitat diversity and reduced lateral connectivity of streams and floodplains. Grade control structures (GCSs) are built in streams to prevent further erosion, protect infrastructure and reduce sediment loads. However, GCS can have a detrimental impact on fisheries and biological communities. We review three complementary biological and hydraulic studies on the effects of GCS in these streams. GCS with steep (≥1:4 rise : run) downstream slopes severely limited fish passage, but GCS with gentle slopes (≤1:15) allowed greater passage. Fish assemblages were dominated by species tolerant of degradation, and Index of Biotic Integrity (IBI) scores were indicative of fair or poor biotic integrity. More than 50% of fish species had truncated distributions. After modification of GCS to reduce slopes and permit increased passage, IBI scores increased and several species were detected further upstream than before modification. Total macroinvertebrate density, biomass and taxonomic diversity and abundance of ecologically sensitive taxa were greater at GCS than in reaches immediately upstream, downstream or ≥1 km from GCS. A hydraulic study confirmed results from fish passage studies; minimum depths and maximum current velocities at GCS with gentle slopes (≤1:15) were more likely to meet minimum criteria for catfish passage than GCS with steeper slopes. Multidisciplinary approaches such as ours will increase understanding of GCS-associated factors influencing fish passage, biological assemblage structure and other ecological relationships in streams.

  2. Effects of river morphology, hydraulic gradients, and sediment deposition on water exchange and oxygen dynamics in salmonid redds.

    Science.gov (United States)

    Schindler Wildhaber, Y; Michel, C; Epting, J; Wildhaber, R A; Huber, E; Huggenberger, P; Burkhardt-Holm, P; Alewell, C

    2014-02-01

    Fine sediment decreasing gravel permeability and oxygen supply to incubating salmonid embryos, is often considered the main contributing factor for the observed decline of salmonid populations. However, oxygen supply to salmonid embryos also depends on hydraulic conditions driving water flow through the redd. A more generalized perspective is needed to better understand the constraints on successful salmonid incubation in the many heavily modified fluvial ecosystems of the Northern Hemisphere. The effects of hydraulic gradients, riverbed and redd morphology as well as fine sediment deposition on dissolved oxygen (DO) and water exchange was studied in 18 artificial redds at three sites along a modified river. Fifty percent of the redds in the two downstream sites were lost during high flow events, while redd loss at the upstream site was substantially lower (8%). This pattern was likely related to increasing flood heights from up- to downstream. Specific water infiltration rates (q) and DO were highly dynamic and driven on multiple temporal and spatial scales. Temporally, the high permeability of the redd gravel and the typical pit-tail structure of the new built redds, leading to high DO, disappeared within a month, when fine sediment had infiltrated and the redd structure was leveled. On the scale of hours to days, DO concentrations and q increased during high flows, but decreased during the falling limb of the water level, most likely related to exfiltration of oxygen depleted groundwater or hyporheic water. DO concentrations also decreased under prolonged base flow conditions, when increased infiltration of silt and clay particles clogged the riverbed and reduced q. Spatially, artificial log steps affected fine sediment infiltration, q and interstitial DO in the redds. The results demonstrate that multiple factors have to be considered for successful river management in salmonid streams, including riverbed structure and local and regional hydrogeological

  3. Effect of temperature, hydraulic residence time and elevated PCO2 on acid neutralization within a pulsed limestone bed reactor

    Science.gov (United States)

    Watten, B.J.; Lee, P.C.; Sibrell, P.L.; Timmons, M.B.

    2007-01-01

    Limestone has potential for reducing reagent costs and sludge volume associated with treatment of acid mine drainage, but its use is restricted by slow dissolution rates and the deposition of Fe, Al and Mn-based hydrolysis products on reactive surfaces. We evaluated a pulsed limestone bed (PLB) reactor (15 L/min capacity) that uses a CO2 pretreatment step to accelerate dissolution and hydraulic shearing forces provided by intermittent fluidization to abrade and carry away surface scales. We established the effects of hydraulic residence time (HRT, 5.1-15.9 min), temperature (T, 12-22 ??C) and CO2 tension (PCO2, 34.5-206.8 kPa) on effluent quality when inlet acidity (Acy) was fixed at 440 mg/L (pH=2.48) with H2SO4. The PLB reactor neutralized all H+ acidity (N=80) while concurrently providing unusually high levels of effluent alkalinity (247-1028 mg/L as CaCO3) that allow for side-stream treatment with blending. Alkalinity (Alk) yields rose with increases in PCO2, HRT and settled bed height (BH, cm) and decreased with T following the relationship (R2=0.926; p<0.001): (Alk)non-filtered=-548.726+33.571??(PCO2)0.5+33.671??(HRT)+7.734??(BH)-5.197??(T). Numerical modeling showed CO2 feed requirements for a target Alk yield decrease with increases in HRT, T and the efficiency of off-gas (CO2) recycling. ?? 2007 Elsevier Ltd. All rights reserved.

  4. MEMBANGUN SISTEM LINUX MANDRAKE MINIMAL MENGGUNAKAN INISIAL DISK RAM

    OpenAIRE

    Wagito, Wagito

    2009-01-01

            Minimal Linux system is commonly used for special systems like router, gateway, Linux installer and diskless Linux system. Minimal Linux system is a Linux system that use a few facilities of all Linux capabilities. Mandrake Linux, as one of Linux distribution is able to perform minimal Linux system.         RAM is a computer resource that especially used as main memory. A  part of RAM’s function can be changed into disk called RAM disk. This RAM disk can be used to run the Linux syste...

  5. Development of a New Apparatus for Investigating Acoustic Effects on Hydraulic Properties of Low-Permeability Geo-Materials

    Science.gov (United States)

    Nakajima, H.; Sawada, A.; Sugita, H.; Takeda, M.; Komai, T.; Zhang, M.

    2006-12-01

    Remediation of polluted soils and groundwater contaminated by heavy metals and non-aqueous phase liquids has been one of the challenging issues in the field of geo-environments. In-situ removal of the contaminants from low permeable soils, such as clay strata, is particularly difficult because of the low mobility, strong adsorption, and/or other various interactions within soils. Thus current remediation techniques, such as pump- and-treat method and even eletrokinetic method, generally suffer from low recovery rates and/or economically unacceptable long remediation periods. A perspective improvement in remediation technology is to couple the electrokinetic method with an application of acoustic waves. This so-called Electro-Acoustic Soil Decontamination (EASD) method has been proposed by Battelle Columbus Labs.(Muralidhara et al. 1990). Simultaneous application of an electric field and an acoustic field may produce a synergistic effect and result in further enhancement of water transport by electro-osmosis in principle, but there is still no fundamental data for the design of EASD method in practical applications. A number of investigations have shown that an application of acoustic waves can increase hydraulic conductivity and mobility of non-aqueous phase liquids in porous media. Most of the prior and ongoing researches in this area have been focused on increasing production from declining oil and gas reservoirs. During several field tests by the oil and gas industries, increases in oil production rates by 20% or more have been reported. However, underlying physical mechanisms for acoustically enhanced fluid transport are not adequately understood. In addition, majority of the past investigations has dealt with applications of large amplitude of acoustic waves to relatively permeable soils or fractured rocks, and there is little information if acoustic wave effectively enhances flow and contaminant transport for less permeable clayey soils. To evaluate the

  6. Rapid and long-term effects of water deficit on gas exchange and hydraulic conductance of silver birch trees grown under varying atmospheric humidity.

    Science.gov (United States)

    Sellin, Arne; Niglas, Aigar; Õunapuu-Pikas, Eele; Kupper, Priit

    2014-03-24

    Effects of water deficit on plant water status, gas exchange and hydraulic conductance were investigated in Betula pendula under artificially manipulated air humidity in Eastern Estonia. The study was aimed to broaden an understanding of the ability of trees to acclimate with the increasing atmospheric humidity predicted for northern Europe. Rapidly-induced water deficit was imposed by dehydrating cut branches in open-air conditions; long-term water deficit was generated by seasonal drought. The rapid water deficit quantified by leaf (ΨL) and branch water potentials (ΨB) had a significant (P gas exchange parameters, while inclusion of ΨB in models resulted in a considerably better fit than those including ΨL, which supports the idea that stomatal openness is regulated to prevent stem rather than leaf xylem dysfunction. Under moderate water deficit (ΨL≥-1.55 MPa), leaf conductance to water vapour (gL), transpiration rate and leaf hydraulic conductance (KL) were higher (P water deficit (ΨLwater availability, i.e. due to higher soil water potential in H treatment. Two functional characteristics (gL, KL) exhibited higher (P water deficit in trees grown under increased air humidity. The experiment supported the hypothesis that physiological traits in trees acclimated to higher air humidity exhibit higher sensitivity to rapid water deficit with respect to two characteristics - leaf conductance to water vapour and leaf hydraulic conductance. Disproportionate changes in sensitivity of stomatal versus leaf hydraulic conductance to water deficit will impose greater risk of desiccation-induced hydraulic dysfunction on the plants, grown under high atmospheric humidity, in case of sudden weather fluctuations, and might represent a potential threat in hemiboreal forest ecosystems. There is no trade-off between plant hydraulic capacity and photosynthetic water-use efficiency on short time scale.

  7. The rapid mode of calcium uptake into heart mitochondria (RaM): comparison to RaM in liver mitochondria.

    Science.gov (United States)

    Buntinas, L; Gunter, K K; Sparagna, G C; Gunter, T E

    2001-04-02

    A mechanism of Ca(2+) uptake, capable of sequestering significant amounts of Ca(2+) from cytosolic Ca(2+) pulses, has previously been identified in liver mitochondria. This mechanism, the Rapid Mode of Ca(2+) uptake (RaM), was shown to sequester Ca(2+) very rapidly at the beginning of each pulse in a sequence [Sparagna et al. (1995) J. Biol. Chem. 270, 27510-27515]. The existence and properties of RaM in heart mitochondria, however, are unknown and are the basis for this study. We show that RaM functions in heart mitochondria with some of the characteristics of RaM in liver, but its activation and inhibition are quite different. It is feasible that these differences represent different physiological adaptations in these two tissues. In both tissues, RaM is highly conductive at the beginning of a Ca(2+) pulse, but is inhibited by the rising [Ca(2+)] of the pulse itself. In heart mitochondria, the time required at low [Ca(2+)] to reestablish high Ca(2+) conductivity via RaM i.e. the 'resetting time' of RaM is much longer than in liver. RaM in liver mitochondria is strongly activated by spermine, activated by ATP or GTP and unaffected by ADP and AMP. In heart, RaM is activated much less strongly by spermine and unaffected by ATP or GTP. RaM in heart is strongly inhibited by AMP and has a biphasic response to ADP; it is activated at low concentrations and inhibited at high concentrations. Finally, an hypothesis consistent with the data and characteristics of liver and heart is presented to explain how RaM may function to control the rate of oxidative phosphorylation in each tissue. Under this hypothesis, RaM functions to create a brief, high free Ca(2+) concentration inside mitochondria which may activate intramitochondrial metabolic reactions with relatively small amounts of Ca(2+) uptake. This hypothesis is consistent with the view that intramitochondrial [Ca(2+)] may be used to control the rate of ADP phosphorylation in such a way as to minimize the probability of

  8. Atomistic mechanisms of ReRAM cell operation and reliability

    Science.gov (United States)

    Pandey, Sumeet C.

    2018-01-01

    We present results from first-principles-based modeling that captures functionally important physical phenomena critical to cell materials selection, operation, and reliability for resistance-switching memory technologies. An atomic-scale description of retention, the low- and high-resistance states (RS), and the sources of intrinsic cell-level variability in ReRAM is discussed. Through the results obtained from density functional theory, non-equilibrium Green’s function, molecular dynamics, and kinetic Monte Carlo simulations; the role of variable-charge vacancy defects and metal impurities in determining the RS, the LRS-stability, and electron-conduction in such RS is reported. Although, the statistical electrical characteristics of the oxygen-vacancy (Ox-ReRAM) and conductive-bridging RAM (M-ReRAM) are notably different, the underlying similar electrochemical phenomena describing retention and formation/dissolution of RS are being discussed.

  9. A fully operational 1-kb variable threshold Josephson RAM

    International Nuclear Information System (INIS)

    Kurosawa, I.; Nakagawa, H.; Aoyagi, M.; Kosaks, S.; Takada, S.

    1991-01-01

    This paper describes the first fully operational Josephson RAM in LSI level integration. The chip was designed as a 4-b x 256-word data RAM unit for a 4-b Josephson computer, The variable threshold memory cell and the relating memory architecture were used. They are so simple in structure that the fabrication is satisfied by the current Josephson junction technology. A directly coupled driver gate for a resistive bit line applies an accurate and stable driving current to the memory cell array. The RAM chip was fabricated with a 3-μm Nb/Al-oxide/Nb junction technology. For obtaining reliable RAM chips, a plasma-enhanced CVD silicon dioxide layer was introduced for insulation between the ground plane and the base electrode. The thermal uniformity of the wafer was improved during the oxidation process for making a tunnel barrier in this work

  10. Study of seasonal sexual activity variations in Algerian rams: Sexual ...

    African Journals Online (AJOL)

    benia

    2013-10-09

    Oct 9, 2013 ... testosterone in sheep, even for Rembi rams, in our .... Blood samples were then transported to the laboratory, centrifuged at 3000 rpm/min for 20 min. ... homogeneity of the data was assessed and conformed to the model.

  11. Performance and carcass characteristics of Yankasa ram fed with ...

    African Journals Online (AJOL)

    Remember me ... and 50% maize and wheat offal mixture, were better when compared to the control (B0) and other test diet in terms of performance and carcass characteristics. ... Key words: Performance, carcass, biscuit waste, Yankasa ram.

  12. Proteomics analysis of ram sperm by heavy ion radiation

    International Nuclear Information System (INIS)

    He Yuxuan; Li Hongyan; Zhang Hong

    2013-01-01

    The objective of this study was to investigate the proteome changes induced by heavy ion radiation using irradiated ram sperm by a two-dimensional electrophoresis (2-DE) analysis. The 2D gels were stained with Coomassie Brilliant Blue. Differentially expressed proteins were detected by PDQuest 8.0 software and subjected to ion trap mass spectrometer equipped with a surveyor HPLC system, and differential protein spots were identified. Results showed there are five differential protein spots in irradiated sperm gels, four up-regulated protein spots and one spot missed. The differentially expressed protein spots were identified to be two up-regulated proteins including enolase, and enolase 1. It was concluded there was proteome changes induced by heavy ion radiation in ram sperm, which may be useful to clarify the physiology state of ram sperm in heavy ion radiation and provide a theoretical basis for radiation ram breeding. (authors)

  13. The effect of vapour pressure deficit on stomatal conductance, sap pH and leaf-specific hydraulic conductance in Eucalyptus globulus clones grown under two watering regimes.

    Science.gov (United States)

    Hernandez, Maria Jose; Montes, Fernando; Ruiz, Federico; Lopez, Gustavo; Pita, Pilar

    2016-05-01

    Stomatal conductance has long been considered of key interest in the study of plant adaptation to water stress. The expected increase in extreme meteorological events under a climate change scenario may compromise survival in Eucalyptus globulus plantations established in south-western Spain. We investigated to what extent changes in stomatal conductance in response to high vapour pressure deficits and water shortage are mediated by hydraulic and chemical signals in greenhouse-grown E. globulus clones. Rooted cuttings were grown in pots and submitted to two watering regimes. Stomatal conductance, shoot water potential, sap pH and hydraulic conductance were measured consecutively in each plant over 4 weeks under vapour pressure deficits ranging 0·42 to 2·25 kPa. Evapotranspiration, growth in leaf area and shoot biomass were also determined. There was a significant effect of both clone and watering regime in stomatal conductance and leaf-specific hydraulic conductance, but not in sap pH. Sap pH decreased as water potential and stomatal conductance decreased under increasing vapour pressure deficit. There was no significant relationship between stomatal conductance and leaf-specific hydraulic conductance. Stomata closure precluded shoot water potential from falling below -1·8 MPa. The percentage loss of hydraulic conductance ranged from 40 to 85 %. The highest and lowest leaf-specific hydraulic conductances were measured in clones from the same half-sib families. Water shortage reduced growth and evapotranspiration, decreases in evapotranspiration ranging from 14 to 32 % in the five clones tested. Changes in sap pH seemed to be a response to changes in atmospheric conditions rather than soil water in the species. Stomata closed after a considerable amount of hydraulic conductance was lost, although intraspecific differences in leaf-specific hydraulic conductance suggest the possibility of selection for improved productivity under water-limiting conditions

  14. Investigation of advanced propulsion technologies: The RAM accelerator and the flowing gas radiation heater

    Science.gov (United States)

    Bruckner, A. P.; Knowlen, C.; Mattick, A. T.; Hertzberg, A.

    1992-01-01

    The two principal areas of advanced propulsion investigated are the ram accelerator and the flowing gas radiation heater. The concept of the ram accelerator is presented as a hypervelocity launcher for large-scale aeroballistic range applications in hypersonics and aerothermodynamics research. The ram accelerator is an in-bore ramjet device in which a projectile shaped like the centerbody of a supersonic ramjet is propelled in a stationary tube filled with a tailored combustible gas mixture. Combustion on and behind the projectile generates thrust which accelerates it to very high velocities. The acceleration can be tailored for the 'soft launch' of instrumented models. The distinctive reacting flow phenomena that have been observed in the ram accelerator are relevant to the aerothermodynamic processes in airbreathing hypersonic propulsion systems and are useful for validating sophisticated CFD codes. The recently demonstrated scalability of the device and the ability to control the rate of acceleration offer unique opportunities for the use of the ram accelerator as a large-scale hypersonic ground test facility. The flowing gas radiation receiver is a novel concept for using solar energy to heat a working fluid for space power or propulsion. Focused solar radiation is absorbed directly in a working gas, rather than by heat transfer through a solid surface. Previous theoretical analysis had demonstrated that radiation trapping reduces energy loss compared to that of blackbody receivers, and enables higher efficiencies and higher peak temperatures. An experiment was carried out to measure the temperature profile of an infrared-active gas and demonstrate the effect of radiation trapping. The success of this effort validates analytical models of heat transfer in this receiver, and confirms the potential of this approach for achieving high efficiency space power and propulsion.

  15. Thermal-Hydraulic Effects of Stud Shape and Size on the Safety Margin of Core Catcher System

    Energy Technology Data Exchange (ETDEWEB)

    Song, Kyusang; Son, Hong Hyun; Jeong, Uiju; Kim, Sung Joong [Hanyang University, Seoul (Korea, Republic of)

    2015-10-15

    With the ERVC strategy, an additional system (core catcher system) to catch molten core penetrating the reactor pressure vessel (RPV) was proposed for advanced light water reactor. The newly engineered corium cooling system, that is, an ex-vessel core catcher system has been designed and adapted in some nuclear power plants such as VVER-1000, EPR, ESBWR, EU-APR1400 to mention a few. For example, Russia adopted a crucible-type core catcher for VVER-1000. On the other hand, a way to catch melt spreading is adopted by several countries, such as EPR in France, ESBWR in USA, ABWR in japan, and EU-APR1400 in Korea In Korea, the core catcher system has been designed and implemented for the European Advanced Power Reactor 1400 (EU-APR1400) to acquire a European license certificate. It is to confine molten materials in the reactor cavity while maintaining a coolable geometry in case that RPV failure occurs. The core catcher system consists of a carbon steel body, sacrificial material, protection material and engineered cooling channel. While installation of the studs is unavoidable, the studs tend to interfere in the smooth streamline of the core catcher channel. The distorted streamline could affect the overall thermal-hydraulic performance including two-phase heat transfer coefficient and critical heat flux (CHF) of the system. Thus, it is of importance to investigate the thermal-hydraulic effects of studs on the coolability, especially the CHF of the core catcher system. With aforementioned importance, pool boiling experiments were carried out with stud shape of, rectangular, cylinder, and elliptic and for stud sizes of 10, 15, 20, and 25 mm under the condition of atmospheric saturated water. A particular attention was focused on observing local vapor behavior around the studs and finding any hot spots, where the vapors are accumulated. The occurrence of the CHF is anticipated at the back side of the studs. The visual observation and CHF measurements indicate that the

  16. Thermal-Hydraulic Effects of Stud Shape and Size on the Safety Margin of Core Catcher System

    International Nuclear Information System (INIS)

    Song, Kyusang; Son, Hong Hyun; Jeong, Uiju; Kim, Sung Joong

    2015-01-01

    With the ERVC strategy, an additional system (core catcher system) to catch molten core penetrating the reactor pressure vessel (RPV) was proposed for advanced light water reactor. The newly engineered corium cooling system, that is, an ex-vessel core catcher system has been designed and adapted in some nuclear power plants such as VVER-1000, EPR, ESBWR, EU-APR1400 to mention a few. For example, Russia adopted a crucible-type core catcher for VVER-1000. On the other hand, a way to catch melt spreading is adopted by several countries, such as EPR in France, ESBWR in USA, ABWR in japan, and EU-APR1400 in Korea In Korea, the core catcher system has been designed and implemented for the European Advanced Power Reactor 1400 (EU-APR1400) to acquire a European license certificate. It is to confine molten materials in the reactor cavity while maintaining a coolable geometry in case that RPV failure occurs. The core catcher system consists of a carbon steel body, sacrificial material, protection material and engineered cooling channel. While installation of the studs is unavoidable, the studs tend to interfere in the smooth streamline of the core catcher channel. The distorted streamline could affect the overall thermal-hydraulic performance including two-phase heat transfer coefficient and critical heat flux (CHF) of the system. Thus, it is of importance to investigate the thermal-hydraulic effects of studs on the coolability, especially the CHF of the core catcher system. With aforementioned importance, pool boiling experiments were carried out with stud shape of, rectangular, cylinder, and elliptic and for stud sizes of 10, 15, 20, and 25 mm under the condition of atmospheric saturated water. A particular attention was focused on observing local vapor behavior around the studs and finding any hot spots, where the vapors are accumulated. The occurrence of the CHF is anticipated at the back side of the studs. The visual observation and CHF measurements indicate that the

  17. Integrated approach for combining sustainability and safety into a RAM analysis, RAM2S (Reliability, Availability, Maintainability, Sustainability and Safety) towards greenhouse gases emission targets

    Energy Technology Data Exchange (ETDEWEB)

    Alvarenga, Tobias V. [Det Norske Veritas (DNV), Hovik, Oslo (Norway)

    2009-07-01

    This paper aims to present an approach to integrate sustainability and safety concerns on top of a typical RAM Analysis to support new enterprises to find alternatives to align themselves to the greenhouse gases emission targets, measured as CO{sub 2} (carbon dioxide) equivalent. This approach can be used to measure the impact of the potential CO{sub 2} equivalent emission levels mainly related to new enterprises with high CO{sub 2} content towards environment and production, as per example, the extraction of oil and gas from the Brazilian Pre-salt layers. In this sense, this integrated approach, combining Sustainability and Safety into a RAM analysis, RAM2S (Reliability, Availability, Maintainability, Sustainability and Safety), can be used to assess the impact of CO{sub 2} 'production' along the entire enterprise life-cycle, including the impact of possible facility shutdown due to emission restrictions limits, as well as due to the occurrence of additional failures modes related to CO{sub 2} corrosion capabilities. Thus, at the end, this integrated approach would allow companies to find out a more cost-effective alternative to adapt their business into the global warming reality, overcoming the inherent threats of greenhouse gases. (author)

  18. Hydraulic Hybrid Vehicles

    Science.gov (United States)

    EPA and the United Parcel Service (UPS) have developed a hydraulic hybrid delivery vehicle to explore and demonstrate the environmental benefits of the hydraulic hybrid for urban pick-up and delivery fleets.

  19. Effects of combined drought and heavy metal stresses on xylem structure and hydraulic conductivity in red maple (Acer rubrum L.).

    Science.gov (United States)

    de Silva, Nayana Dilini Gardiyehewa; Cholewa, Ewa; Ryser, Peter

    2012-10-01

    The effects of heavy metal stress, drought stress, and their combination on xylem structure in red maple (Acer rubrum) seedlings were investigated in an outdoor pot experiment. As metal-contaminated substrate, a mixture of 1.5% slag with sand was used, with Ni, Cu, Co, and Cr as the main contaminants. Plants grown on contaminated substrate had increased leaf metal concentrations. The two stresses reduced plant growth in an additive manner. The effects of metal and drought stresses on xylem characteristics were similar to each other, with a reduced proportion of xylem tissue, reduced conduit density in stems, and reduced conduit size in the roots. This resulted, in both stems and roots, in reductions in hydraulic conductance, xylem-specific conductivity, and leaf-specific conductivity. The similarity of the responses to the two stresses suggests that the plants' response to metals was actually a drought response, probably due to the reduced water uptake capacity of the metal-exposed roots. The only plant responses specific to metal stress were decreasing trends of stomatal density and chlorophyll content. In conclusion, the exposure to metals aggravates water stress in an additive manner, making the plants more vulnerable to drought.

  20. Radiation response of two Harris semiconductor radiation hardened 1k CMOS RAMs

    International Nuclear Information System (INIS)

    Abare, W.E.; Huffman, D.D.; Moffett, G.E.

    1982-01-01

    This paper describes the testing of two types 1K CMOS static RAMs in various transient and steady state ionizing radiation environments. Type HM 6551R (256x4 bits) and type HM 6508R (1024x1 bit) RAMs were evaluated. The RAMs are radiation hardened versions of Harris' commercial RAMs. A brief description of the radiation hardened process is presented

  1. User effects on the thermal-hydraulic transient system code calculations

    International Nuclear Information System (INIS)

    Aksan, S.N.; D'Auria, F.; Staedtke, H.

    1993-01-01

    In the paper, the results of the investigations on the user effects for the thermalhydraulic transient system codes will be presented and discussed on the basis of some case studies. The general findings of the investigations show that in addition to user effects, there are other reasons that affect the results of the calculations and which are hidden under user effects. Both the hidden factors and the direct user effects will be discussed in detail and general recommendations and conclusions will be presented to control and limit them. (orig.)

  2. Effect of hydraulic retention time on deterioration/restarting of sludge anaerobic digestion: Extracellular polymeric substances and microbial response.

    Science.gov (United States)

    Wei, Liangliang; An, Xiaoyan; Wang, Sheng; Xue, Chonghua; Jiang, Junqiu; Zhao, Qingliang; Kabutey, Felix Tetteh; Wang, Kun

    2017-11-01

    In this study, the transformation of the sludge-related extracellular polymeric substances (EPS) during mesophilic anaerobic digestion was characterized to assess the effect of hydraulic retention time (HRT) on reactor deterioration/restarting. Experimental HRT variations from 20 to 15 and 10d was implemented for deterioration, and from 10 to 20d for restarting. Long-term digestion at the lowest HRT (10d) resulted in significant accumulation of hydrolyzed hydrophobic materials and volatile fatty acids in the supernatants. Moreover, less efficient hydrolysis of sludge EPS, especially of proteins related substances which contributed to the deterioration of digester. Aceticlastic species of Methanosaetaceae decreased from 36.3% to 27.6% with decreasing HRT (20-10d), while hydrogenotrophic methanogens (Methanomicrobiales and Methanobacteriales) increased from 30.4% to 38.3%. Proteins and soluble microbial byproducts related fluorophores in feed sludge for the anaerobic digester changed insignificantly at high HRT, whereas the fluorescent intensity of fulvic acid-like components declined sharply once the digestion deteriorated. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Effect of Hydraulic Retention Time on Anaerobic Digestion of Wheat Straw in the Semicontinuous Continuous Stirred-Tank Reactors

    Directory of Open Access Journals (Sweden)

    Xiao-Shuang Shi

    2017-01-01

    Full Text Available Three semicontinuous continuous stirred-tank reactors (CSTR operating at mesophilic conditions (35°C were used to investigate the effect of hydraulic retention time (HRT on anaerobic digestion of wheat straw. The results showed that the average biogas production with HRT of 20, 40, and 60 days was 46.8, 79.9, and 89.1 mL/g total solid as well as 55.2, 94.3, and 105.2 mL/g volatile solids, respectively. The methane content with HRT of 20 days, from 14.2% to 28.5%, was the lowest among the three reactors. The pH values with HRT of 40 and 60 days were in the acceptable range compared to that with HRT of 20 days. The propionate was dominant in the reactor with HRT of 20 days, inhibiting the activities of methanogens and causing the lower methane content in biogas. The degradation of cellulose, hemicellulose, and crystalline cellulose based on XRD was also strongly influenced by HRTs.

  4. The effect of nutrient enrichment on growth, photosynthesis and hydraulic conductance of dwarf mangroves in Panamá

    Science.gov (United States)

    Lovelock, C.E.; Feller, Ilka C.; McKee, K.L.; Engelbrecht, B.M.J.; Ball, M.C.

    2004-01-01

    1. Dwarf stands of the mangrove Rhizophora mangle L. are extensive in the Caribbean. We fertilized dwarf trees in Almirante Bay, Bocas del Toro Province, north-eastern Panama with nitrogen (N) and phosphorus (P) to determine (1) if growth limitations are due to nutrient deficiency; and (2) what morphological and/or physiological factors underlie nutrient limitations to growth. 2. Shoot growth was 10-fold when fertilized with P and twofold with N fertilization, indicating that stunted growth of these mangroves is partially due to nutrient deficiency. 3. Growth enhancements caused by N or P enrichment could not be attributed to increases in photosynthesis on a leaf area basis, although photosynthetic nutrient-use efficiency was improved. The most dramatic effect was on stem hydraulic conductance, which was increased sixfold by P and 2-5-fold with N enrichment. Fertilization with P enhanced leaf and stem P concentrations and reduced C:N ratio, but did not alter leaf damage by herbivores. 4. Our findings indicate that addition of N and P significantly alter tree growth and internal nutrient dynamics of mangroves at Bocas del Toro, but also that the magnitude, pattern and mechanisms of change will be differentially affected by each nutrient.

  5. Effect of hydraulic retention time on ABR tail water treatment by contact oxidation process under low oxygen condition

    Science.gov (United States)

    Huang, Xiaolong; Shi, Chunhong; Wang, Zhenbao; Jiang, Kai

    2018-02-01

    Biological contact oxidation process of low dissolved oxygen was applied to the treatment of ABR tail water, which were pretreatment effluent for Island sewage. The reactor was built and filled with polyurethane suspension filler as carrier for biofilm growth in laboratory. The dissolved oxygen in the reactor is kept at 1.3-1.8mg/L to distinguish between traditional method which is 2.5-3.5mg/L. Influence of hydraulic retention time(HRT) on ABR tail water treatment by the process was studied. Results show that the system has good effect on removal of COD and TN under this condition. When HRT is among 4h to 12h, the removal rate of COD can be maintained at 80-90%.From period 1 to period 3, the removal rate of NH4 +N and TN at the end of each period can be recovered to a higher level, and the average removal rate after stabilization is 99% and 67% respectively which can come up to first grade of the national standard GB18918-2002. It is remarkable that when HRT is 4h, the removal rate of NH4 +-N and TN showed a significant decrease trend, the concentration of effluent was 14.79mg/L and 19.5mg/L, respectively.

  6. Polyelectrolyte addition effect on the properties of setting hydraulic cements based on calcium phosphate

    International Nuclear Information System (INIS)

    Santos, Luis A. dos; Oliveira, Luci C. de; Rigo, Eliana C.S.; Boschi, Anselmo Ortega; Carrodeguas, Raul Gracia

    1997-01-01

    In the present work the effects of the addition of some poly electrolytes (sodium alginate and poly acrylic acid) on the solubility, crystalline phases, pH and mechanical strength under compression of three calcium phosphate cements were studied. (author)

  7. Nuclear-coupled thermal-hydraulic nonlinear stability analysis using a novel BWR reduced order model. Pt. 1. The effects of using drift flux versus homogeneous equilibrium models

    International Nuclear Information System (INIS)

    Dokhane, A.; Henning, D.; Chawla, R.; Rizwan-Uddin

    2003-01-01

    BWR stability analysis at PSI, as at other research centres, is usually carried out employing complex system codes. However, these do not allow a detailed investigation of the complete manifold of all possible solutions of the associated nonlinear differential equation set. A novel analytical, reduced order model for BWR stability has been developed at PSI, in several successive steps. In the first step, the thermal-hydraulic model was used for studying the thermal-hydraulic instabilities. A study was then conducted of the one-channel nuclear-coupled thermal-hydraulic dynamics in a BWR by adding a simple point kinetic model for neutron kinetics and a model for the fuel heat conduction dynamics. In this paper, a two-channel nuclear-coupled thermal-hydraulic model is introduced to simulate the out-of phase oscillations in a BWR. This model comprises three parts: spatial mode neutron kinetics with the fundamental and fist azimuthal modes; fuel heat conduction dynamics; and thermal-hydraulics model. This present model is an extension of the Karve et al. model i.e., a drift flux model is used instead of the homogeneous equilibrium model for two-phase flow, and lambda modes are used instead of the omega modes for the neutron kinetics. This two-channel model is employed in stability and bifurcation analyses, carried out using the bifurcation code BIFDD. The stability boundary (SB) and the nature of the Poincare-Andronov-Hopf bifurcation (PAF-B) are determined and visualized in a suitable two-dimensional parameter/state space. A comparative study of the homogeneous equilibrium model (HEM) and the drift flux model (DFM) is carried out to investigate the effects of the DFM parameters the void distribution parameter C 0 and the drift velocity V gi -on the SB, the nature of PAH bifurcation, and on the type of oscillation mode (in-phase or out-of-phase). (author)

  8. Asymmetric Star Formation Efficiency Due to Ram Pressure Stripping

    Directory of Open Access Journals (Sweden)

    Paulina Troncoso Iribarren

    2016-12-01

    Full Text Available Previous works have shown that a dense cluster environment affects satellite galaxy properties and accelerates or truncates their evolutionary processes. In this work, we use the EAGLE simulation to study this effect, dissecting the galaxies in two halves: the one that is falling directly to the cluster (leading half and the one behind (trailing half. Considering all galaxies within the virial radius of the most massive groups and clusters of the simulation ( M h a l o > 10 13 . 8 [ M ⊙ ] , we find that on average the leading half presents an enhancement of the star formation rate with respect to the trailing half. We conclude that galaxies falling into the intra-cluster medium experience a boost in star-formation in their leading half due to ram pressure. Sparse observations of jellyfish galaxies have revealed visually the enhancement of the star formation in the leading half. In order to confirm this effect statistically using observations, different cases must be investigated using the simulation as a test dataset.

  9. Carbamazepine behaviour and effects in an urban wastewater MBR working with high sludge and hydraulic retention time.

    Science.gov (United States)

    González-Pérez, Daniel María; Pérez, Jorge Ignacio; Nieto, Miguel Ángel Gómez

    2016-08-23

    The behaviour and fate of carbamazepine (CBZ) in urban wastewater treatment by a membrane bioreactor (MBR) and its possible effects on the system's efficiency, and on mixed microbial communities, has been studied. The experimental microfiltration MBR system, with capacity to treat 10.8 m(3) d(-1) of urban wastewater, operated with a pre-denitrification configuration with high sludge and hydraulic retention time. The CBZ concentration assayed was higher than in the usual urban wastewater, in order to provoke a strong biomass reaction. Influent, effluent, and all bioreactors of the MBR system were analysed in order to calculate a CBZ balance. Bench-scale experiments and respirometric analyses were performed, with and without the presence of CBZ, to evaluate its influence on the bacterial activity. The respirometric assays showed variations in the oxygen uptake rate (OUR) in the presence of CBZ. Negative effects were detected in the MBR bacterial community during the initial period of dosing. However, the effects were not permanent and the biomass spiked with CBZ had behaviour similar to that of the biomass without CBZ after a few hours. Biodegradation was not detected during the MBR treatment. The system showed an inefficient elimination of CBZ (less than 10%) with a high concentration in the effluent. The small percentage of CBZ removal was associated with the sludge retention and eliminated by the purge. All CBZ present in the influent was accounted for, and even an increase in the total amount of CBZ was registered in the permeate. During and after the experimental process, CBZ did not significantly affect the efficiency of the MBR system, and the quality of the effluent was not affected by the dosing of CBZ in terms of COD and nitrogen removal.

  10. Effect of tip clearance on performance of small axial hydraulic turbine

    Science.gov (United States)

    Boynton, J. L.; Rohlik, H. E.

    1976-01-01

    The first two stages of a six stage liquid oxygen turbine were tested in water. One and two stage performance was determined for one shrouded and two unshrouded blade end configurations over ranges of clearance and blade-jet speed ratio. First stage, two stage, and second stage efficiencies are included as well as the effect of clearance on mass flow for two stage operation.

  11. Cryopreservation of ram semen in extenders containing soybean lecithin as cryoprotectant and hyaluronic acid as antioxidant.

    Science.gov (United States)

    Najafi, A; Najafi, M H; Zanganeh, Z; Sharafi, M; Martinez-Pastor, F; Adeldust, H

    2014-12-01

    A soybean lecithin-based extender supplemented with hyaluronic acid (HA) was assayed for effectiveness to improve the quality of frozen-thawed ram semen. HA has not been tested yet in an extender containing soybean lecithin for freezing ram semen. Thus, the aim of this study was to analyse the effects of soybean lecithin at 1% or 1.5% along with HA at 0, 0.5 and 1 mg ml(-1) in a Tris-based extender on the motion characteristics, membrane integrity (HOST), viability, GSH peroxidase (GSH-PX) activity, lipid peroxidation and acrosomal status after freezing-thawing. Semen was collected from four Mehraban rams during the breeding season and frozen in the six lecithin×HA extenders. The extender containing 1.5% lecithin supplemented with no HA yielded higher total motility (52.5%±1.6), viability (55.8%±1.6) and membrane integrity (44.5%±1.7), but the effects of the lecithin concentration did not reach signification. Linearity-related parameters, ALH, BCF, lipid peroxidation, GSH-PX activity, morphology and acrosomal status were not affected by the extender composition. In general, adding HA significantly decreased sperm velocity (1 mg ml(-1) HA), total motility (only with 1.5% lecithin), viability (1 mg ml(-1) HA for 1% lecithin; both concentrations for 1.5% lecithin) and membrane integrity. In conclusion, adding HA to the freezing extender supplemented with soybean lecithin failed to improve quality-related variables in ram semen. Increasing the lecithin content could have a positive effect, but further studies are needed. © 2014 Blackwell Verlag GmbH.

  12. The Thermal-hydraulic Analysis for the Aging Effect of the Component in CANDU-6 Reactor

    International Nuclear Information System (INIS)

    Bae, Jun Ho; Jung, Jong Yeob

    2014-01-01

    CANDU reactor consists of a lot of components, including pressure tube, reactor pump, steam generator, feeder pipe, and so on. These components become to have the aging characteristics as the reactor operates for a long time. The aging phenomena of these components lead to the change of operating parameters, and it finally results to the decrease of the operating safety margin. Actually, due to the aging characteristics of components, CANDU reactor power plant has the operating license for the duration of 30 years and the plant regularly check the plant operating state in the overhaul period. As the reactor experiences the aging, the reactor operators should reduce the reactor power level in order to keep the minimum safety margin, and it results to the deficit of economical profit. Therefore, in order to establish the safety margin for the aged reactor, the aging characteristics for components should be analyzed and the effect of aging of components on the operating parameter should be studied. In this study, the aging characteristics of components are analyzed and revealed how the aging of components affects to the operating parameter by using NUCIRC code. Finally, by scrutinizing the effect of operating parameter on the operating safety margin, the effect of aging of components on the safety margin has been revealed

  13. Transient thermal, hydraulic, and mechanical analysis of a counter flow offset strip fin intermediate heat exchanger using an effective porous media approach

    Science.gov (United States)

    Urquiza, Eugenio

    This work presents a comprehensive thermal hydraulic analysis of a compact heat exchanger using offset strip fins. The thermal hydraulics analysis in this work is followed by a finite element analysis (FEA) to predict the mechanical stresses experienced by an intermediate heat exchanger (IHX) during steady-state operation and selected flow transients. In particular, the scenario analyzed involves a gas-to-liquid IHX operating between high pressure helium and liquid or molten salt. In order to estimate the stresses in compact heat exchangers a comprehensive thermal and hydraulic analysis is needed. Compact heat exchangers require very small flow channels and fins to achieve high heat transfer rates and thermal effectiveness. However, studying such small features computationally contributes little to the understanding of component level phenomena and requires prohibitive computational effort using computational fluid dynamics (CFD). To address this issue, the analysis developed here uses an effective porous media (EPM) approach; this greatly reduces the computation time and produces results with the appropriate resolution [1]. This EPM fluid dynamics and heat transfer computational code has been named the Compact Heat Exchanger Explicit Thermal and Hydraulics (CHEETAH) code. CHEETAH solves for the two-dimensional steady-state and transient temperature and flow distributions in the IHX including the complicating effects of temperature-dependent fluid thermo-physical properties. Temperature- and pressure-dependent fluid properties are evaluated by CHEETAH and the thermal effectiveness of the IHX is also calculated. Furthermore, the temperature distribution can then be imported into a finite element analysis (FEA) code for mechanical stress analysis using the EPM methods developed earlier by the University of California, Berkeley, for global and local stress analysis [2]. These simulation tools will also allow the heat exchanger design to be improved through an

  14. Ram Pressure Stripping Made Easy: An Analytical Approach

    Science.gov (United States)

    Köppen, J.; Jáchym, P.; Taylor, R.; Palouš, J.

    2018-06-01

    The removal of gas by ram pressure stripping of galaxies is treated by a purely kinematic description. The solution has two asymptotic limits: if the duration of the ram pressure pulse exceeds the period of vertical oscillations perpendicular to the galactic plane, the commonly used quasi-static criterion of Gunn & Gott is obtained which uses the maximum ram pressure that the galaxy has experienced along its orbit. For shorter pulses the outcome depends on the time-integrated ram pressure. This parameter pair fully describes the gas mass fraction that is stripped from a given galaxy. This approach closely reproduces results from SPH simulations. We show that typical galaxies follow a very tight relation in this parameter space corresponding to a pressure pulse length of about 300 Myr. Thus, the Gunn & Gott criterion provides a good description for galaxies in larger clusters. Applying the analytic description to a sample of 232 Virgo galaxies from the GoldMine database, we show that the ICM provides indeed the ram pressures needed to explain the deficiencies. We also can distinguish current and past strippers, including objects whose stripping state was unknown.

  15. Inherent Limitations of Hydraulic Tomography

    Science.gov (United States)

    Bohling, Geoffrey C.; Butler, J.J.

    2010-01-01

    We offer a cautionary note in response to an increasing level of enthusiasm regarding high-resolution aquifer characterization with hydraulic tomography. We use synthetic examples based on two recent field experiments to demonstrate that a high degree of nonuniqueness remains in estimates of hydraulic parameter fields even when those estimates are based on simultaneous analysis of a number of carefully controlled hydraulic tests. We must, therefore, be careful not to oversell the technique to the community of practicing hydrogeologists, promising a degree of accuracy and resolution that, in many settings, will remain unattainable, regardless of the amount of effort invested in the field investigation. No practically feasible amount of hydraulic tomography data will ever remove the need to regularize or bias the inverse problem in some fashion in order to obtain a unique solution. Thus, along with improving the resolution of hydraulic tomography techniques, we must also strive to couple those techniques with procedures for experimental design and uncertainty assessment and with other more cost-effective field methods, such as geophysical surveying and, in unconsolidated formations, direct-push profiling, in order to develop methods for subsurface characterization with the resolution and accuracy needed for practical field applications. Copyright ?? 2010 The Author(s). Journal compilation ?? 2010 National Ground Water Association.

  16. Semi-continuous anaerobic digestion of solid poultry slaughterhouse waste: effect of hydraulic retention time and loading.

    Science.gov (United States)

    Salminen, Esa A; Rintala, Jukka A

    2002-07-01

    We studied the effect of hydraulic retention time (HRT) and loading on anaerobic digestion of poultry slaughterhouse wastes, using semi-continuously fed, laboratory-scale digesters at 31 degrees C. The effect on process performance was highly significant: Anaerobic digestion appeared feasible with a loading of up to 0.8 kg volatile solids (VS)/m3 d and an HRT of 50-100 days. The specific methane yield was high, from 0.52 to 0.55 m3/kg VS(added). On the other hand, at a higher loading, in the range from 1.0 to 2.1 kg VS/m3 d, and a shorter HRT, in the range from 25 to 13 days, the process appeared inhibited and/or overloaded, as indicated by the accumulation of volatile fatty acids and long-chain fatty acids and the decline in the methane yield. However, the inhibition was reversible. The nitrogen in the feed, ca. 7.8% of total solids (TS), was organic nitrogen with little ammonia present, whereas in the digested material ammonia accounted for 52-67% (up to 3.8 g/l) of total nitrogen. The TS and VS removals amounted to 76% and 64%, respectively. Our results show that on a continuous basis under the studied conditions and with a loading of up to 0.8 kg VS/m3 d metric ton (wet weight) of the studied waste mixture could yield up to 140 m3 of methane.

  17. The effects of hydraulic works and wetlands function in the Salado-River basin (Buenos Aires, Argentina).

    Science.gov (United States)

    Bazzuri, M E; Gabellone, N A; Solari, L C

    2018-01-26

    Man-made activities exert great influences on fluvial ecosystems, with lowland rivers being substantially modified through agricultural land use and populations. The recent construction of drainage canals in the upper stretch of the Salado-River basin caused the mobilization of huge amounts of salts formerly stored in the groundwater. The main aim of this work was to analyze the effect of the discharges of those canals into the Salado-River water, under different hydrologic conditions, and the role of the wetlands and shallow lakes placed along the canals' system. Physicochemical variables were measured and water samples were taken during times of high water, mean flows, drought, and extreme drought. The environmental variables and the plankton development were related to the hydrologic regime and reached minimum values during floods because of low temperatures and dilution. Local effects on the water's ionic composition became pronounced during droughts because of groundwater input. Nutrient concentrations were mainly associated with point wastewater discharges. Conductivity, ion concentrations, total plankton biomass, and species richness increased in the Salado-River downstream site, after the canals' discharges. The artificial-drainage system definitely promotes the incorporation of salts into the Salado-River basin. In this scenario, a careful hydraulic management is needed to take into account this issue of secondary salinization that threatens the economic exploitation of the region. The wetlands present in this study acted as service environments not only helping to reduce salt, nutrient, and suspended-solid concentrations downstream but also contributing a plethora of species and plankton biomass into the Salado-River main course.

  18. Fort St. Vrain fuel-handling system RAM analysis

    International Nuclear Information System (INIS)

    Azizi, S.M.; Berg, G.E.; Burton, J.H.; Durand, R.E.; Larson, E.M.; Pepe, D.J.; Rutherford, P.D.; Novachek, F.J.

    1989-01-01

    Public Service of Company of Colorado (PSC) is planning to decommission its Fort St. Vrain plant in 1990. This requires removal of 1,500 separate assemblies from the core. With the low historical availability of the fuel-handling system (FHS), defueling time was estimated at 36 months. With plant expenses of approximately $1.6 million per month during defueling, this would mean a schedule cost of $58 million. With their contractor, Rockwell International, PSC embarked on a reliability, availability, and maintainability (RAM) analysis to reduce projected defueling time. Key elements included (a) estimating availability of the FHS using a limited historical record, (b) assessing the defueling critical path, and (c) proposing and evaluating design/operational improvements. The most cost-effective improvements are being implemented and are expected to provide a reduction of >18 months in schedule and a net savings of $20 to 25 million. The paper describes the FHS design and operation, major problems associated with fuel-handling operations, and results and recommendations

  19. Geographic Resolution Issues in RAM Transport Risk Analysis

    International Nuclear Information System (INIS)

    Mills, G.S.; Neuhauser, K.S.

    2000-01-01

    Transport risk analyses based on the RADTRAN code have been met with continual demands for increased spatial resolution of variations in population densities and other parameters employed in the calculation of risk estimates for transport of radioactive material (RAM). With the advent of geographic information systems (GISs) large quantities of data required to describe transport routes, which may extend to hundreds of kilometers, with high resolution (e.g. 1 km segments) can be handled without inordinate expense. This capability has raised a question concerning the maximum resolution of available input data and compatibility with RADTRAN computational models. Quantitative examinations are presented of spatial resolution issues in the calculation of incident-free doses and accident dose risks. For incident-free calculations, the effect of decreasing route-segment length on accuracy, in view of the model employed, is examined, and means of reducing total data input to the RADTRAN calculations, without loss of meaningful resolution of population concentrations, are presented. In the case of accident-risk calculations, the ability to detail population density under very large dispersal plumes permits comparison of plume modelling to actual data. In both types of calculations, meaningful limits to geographic extent are suggested. (author)

  20. MHD simulations of ram pressure stripping of a disc galaxy

    Science.gov (United States)

    Ramos-Martínez, Mariana; Gómez, Gilberto C.; Pérez-Villegas, Ángeles

    2018-05-01

    The removal of the interstellar medium (ISM) of disc galaxies through ram pressure stripping (RPS) has been extensively studied in numerous simulations. Nevertheless, the role of magnetic fields (MFs) on the gas dynamics in this process has been hardly studied, although the MF influence on the large-scale disc structure is well established. With this in mind, we present a 3D magnetohydrodynamic simulation of face-on RPS of a disc galaxy to study the impact of the galactic MF in the gas stripping. The main effect of including a galactic MF is a flared disc. When the intracluster medium wind hits this flared disc, oblique shocks are produced at the interaction interface, where the ISM is compressed, generating a gas inflow from large radii towards the central regions of the galaxy. This inflow is observed for {˜ } 150 {Myr} and may supply the central parts of the galaxy with material for star formation while the outskirts of the disc are being stripped of gas, thus the oblique shocks can induce and enhance the star formation in the remaining disc. We also observed that the MF alters the shape and structure of the swept gas, giving a smooth appearance in the magnetized case and clumpier and filamentary-like morphology in the hydro case. Finally, we estimated the truncation radius expected for our models using the Gunn-Gott criterion and found that that is in agreement with the simulations.

  1. Promoting water hydraulics in Malaysia: A green educational approach

    Science.gov (United States)

    Yusof, Ahmad Anas; Zaili, Zarin Syukri; Hassan, Siti Nor Habibah; Tuan, Tee Boon; Saadun, Mohd Noor Asril; Ibrahim, Mohd Qadafie

    2014-10-01

    In promoting water hydraulics in Malaysia, this paper presents research development of water hydraulics educational training system for secondary and tertiary levels in Malaysia. Water hydraulics trainer with robotic attachment has been studied in order to promote the usefulness of such educational tools in promoting sustainability and green technology in the country. The trainer is being developed in order to allow constructive curriculum development and continuous marketing research for the effectiveness and usefulness of using water in hydraulic power trainer. The research on water-based hydraulic trainer is now possible with the current development in water hydraulics technology.

  2. Effect of flow velocity, substrate concentration and hydraulic cleaning on biofouling of reverse osmosis feed channels

    KAUST Repository

    Radu, Andrea I.

    2012-04-01

    A two-dimensional mathematical model coupling fluid dynamics, salt and substrate transport and biofilm development in time was used to investigate the effects of cross-flow velocity and substrate availability on biofouling in reverse osmosis (RO)/nanofiltration (NF) feed channels. Simulations performed in channels with or without spacer filaments describe how higher liquid velocities lead to less overall biomass amount in the channel by increasing the shear stress. In all studied cases at constant feed flow rate, biomass accumulation in the channel reached a steady state. Replicate simulation runs prove that the stochastic biomass attachment model does not affect the stationary biomass level achieved and has only a slight influence on the dynamics of biomass accumulation. Biofilm removal strategies based on velocity variations are evaluated. Numerical results indicate that sudden velocity increase could lead to biomass sloughing, followed however by biomass re-growth when returning to initial operating conditions. Simulations show particularities of substrate availability in membrane devices used for water treatment, e.g., the accumulation of rejected substrates at the membrane surface due to concentration polarization. Interestingly, with an increased biofilm thickness, the overall substrate consumption rate dominates over accumulation due to substrate concentration polarization, eventually leading to decreased substrate concentrations in the biofilm compared to bulk liquid. © 2012 Elsevier B.V.

  3. Improvement of auditing technology of safety analysis through thermal-hydraulic separate effect tests

    Energy Technology Data Exchange (ETDEWEB)

    No, Hee Cheon; Park, Hyun Sik; Kim, Hyougn Tae; Moon, Young Min; Choi, Sung Won; Heo, Sun [Korea Advanced Institute Science and Technology, Taejon (Korea, Republic of)

    1999-04-15

    The loss-of-RHR accident during midloop operation has been important as results of the probabilistic safety analysis. The condensation models In RELAP5/MOD3 are not proper to analyze the midloop operation. To audit and improve the model in RELAP5/MOD3.2, several items of separate effect tests have been performed. The 29 sets of reflux condensation data is obtained and the correlation is developed with these heat transfer coefficient's data. In the experiment of the direct contact condensation in hot leg, the apparatus setting is finished and a few experimental data is obtained. Non-iterative model is used to predict the model in RELAP5/MOD3.2 with the results of reflux condensation and evaluates better than the present model. The results of the direct contact condensation in a hot leg represent to be similar with the present model. The study of the CCF and liquid entrainment in a surge line and pressurizer is selected as the third separate experiment and is on performance.

  4. Root induced changes of effective 1D hydraulic properties in a soil column.

    Science.gov (United States)

    Scholl, P; Leitner, D; Kammerer, G; Loiskandl, W; Kaul, H-P; Bodner, G

    Roots are essential drivers of soil structure and pore formation. This study aimed at quantifying root induced changes of the pore size distribution (PSD). The focus was on the extent of clogging vs. formation of pores during active root growth. Parameters of Kosugi's lognormal PSD model were determined by inverse estimation in a column experiment with two cover crops (mustard, rye) and an unplanted control. Pore dynamics were described using a convection-dispersion like pore evolution model. Rooted treatments showed a wider range of pore radii with increasing volumes of large macropores >500 μm and micropores <2.5 μm, while fine macropores, mesopores and larger micropores decreased. The non-rooted control showed narrowing of the PSD and reduced porosity over all radius classes. The pore evolution model accurately described root induced changes, while structure degradation in the non-rooted control was not captured properly. Our study demonstrated significant short term root effects with heterogenization of the pore system as dominant process of root induced structure formation. Pore clogging is suggested as a partial cause for reduced pore volume. The important change in micro- and large macropores however indicates that multiple mechanic and biochemical processes are involved in root-pore interactions.

  5. Controls of Hydraulic Wind Turbine

    Directory of Open Access Journals (Sweden)

    Zhang Yin

    2016-01-01

    Full Text Available In this paper a hydraulic wind turbine generator system was proposed based on analysis the current wind turbines technologies. The construction and principles were introduced. The mathematical model was verified using MATLAB and AMsim. A displacement closed loop of swash plate of motor and a speed closed loop of generator were setup, a PID control is introduced to maintain a constant speed and fixed frequency at wind turbine generator. Simulation and experiment demonstrated that the system can connect grid to generate electric and enhance reliability. The control system demonstrates a high performance speed regulation and effectiveness. The results are great significant to design a new type hydraulic wind turbine system.

  6. Efeito da concentração e temperatura de adição de trealose em diluentes para a congelação de sêmen ovino em palhetas Effect of the concentration and addition temperature of trehalose in extenders on freezing ram semen in straws

    Directory of Open Access Journals (Sweden)

    Adilson Moura

    1995-01-01

    Full Text Available A trealose é um dissacarídio com potencial emprego como crioprotetor quando adicionada aos meios para congelamento de sêmen ovino. Este experimento foi realizado para verificar os efeitos da temperatura de adição (30°C e 4°C e da concentração de trealose (2%, 4% e 6% sobre o sêmen ovino congelado em palhetas, utilizando como base as formulações INRA e TRIS/FRUTOSE. Os efeitos estudados em ambos experimentos foram medidos através da avaliação da motilidade espermática (MOT e da integridade de acrossomas (INTA em diferentes momentos após o descongelamento (0h, 2h e 5h. Os presentes resultados não recomendam a inclusão da trealose visando incrementar a qualidade in vitro do sêmen ovino congelado em palhetas nas concentrações e diluentes testados, porém, sugerem maiores estudos quanto a sua toxidade e possíveis interações com outros constituintes dos diluentes já formulados para o congelamento de sêmen ovino.This study was aimed to evaluate the possible effects of the addition of trehalose to extenders developed for freezing ram semen in straws. The effects of addition temperature (30°C and 4°C and concentration of trehalose (2, 4 and 6% on INRA and TRIS/FRUTOSE diluents was evaluated. Their effects were studied through motility rate and by acrosome integrity at different incubation times after thawing (0, 2 and 5h. The results do not recommend the inclusion of trehalose in these diluents. However, it would be interesting to learn more about toxicity and interactions between the components of the extenders and trehalose in ram sperm frozen in straws.

  7. Rational mapping (RAM) of in-core data

    International Nuclear Information System (INIS)

    Bonalumi, R.A.; Kherani, N.P.

    1985-01-01

    A unique processing of in-core flux detector data is described and demonstrated, such that the detailed in-core power distribution can be derived with great accuracy by combining a speciall ''smoothed-out'' set of in-core data with neutron diffusion theory. Rational Mapping (RAM) is designed in such a way that erratic detector signals are recognized very efficiently and can be eliminated from the experimental data set: This is achieved by modal expansion of the difference between theoretical fluxes and experimental fluxes at the detector sites. Sensitivity studies have shown that RAM is quite stable, does not absorb the ''wild'' detector error in the mapping procedure, and results in mapped fluxes with errors about three times smaller than would be obtained by direct interpolation of detector readings. A new method is described to infer corrections to theoretical core parameters based on the difference between the RAM fluxes and the theoretical fluxes

  8. Hydraulic and Mechanical Effects from Gas Hydrate Conversion and Secondary Gas Hydrate Formation during Injection of CO2 into CH4-Hydrate-Bearing Sediments

    Science.gov (United States)

    Bigalke, N.; Deusner, C.; Kossel, E.; Schicks, J. M.; Spangenberg, E.; Priegnitz, M.; Heeschen, K. U.; Abendroth, S.; Thaler, J.; Haeckel, M.

    2014-12-01

    The injection of CO2 into CH4-hydrate-bearing sediments has the potential to drive natural gas production and simultaneously sequester CO2 by hydrate conversion. The process aims at maintaining the in situ hydrate saturation and structure and causing limited impact on soil hydraulic properties and geomechanical stability. However, to increase hydrate conversion yields and rates it must potentially be assisted by thermal stimulation or depressurization. Further, secondary formation of CO2-rich hydrates from pore water and injected CO2 enhances hydrate conversion and CH4 production yields [1]. Technical stimulation and secondary hydrate formation add significant complexity to the bulk conversion process resulting in spatial and temporal effects on hydraulic and geomechanical properties that cannot be predicted by current reservoir simulation codes. In a combined experimental and numerical approach, it is our objective to elucidate both hydraulic and mechanical effects of CO2 injection and CH4-CO2-hydrate conversion in CH4-hydrate bearing soils. For the experimental approach we used various high-pressure flow-through systems equipped with different online and in situ monitoring tools (e.g. Raman microscopy, MRI and ERT). One particular focus was the design of triaxial cell experimental systems, which enable us to study sample behavior even during large deformations and particle flow. We present results from various flow-through high-pressure experimental studies on different scales, which indicate that hydraulic and geomechanical properties of hydrate-bearing sediments are drastically altered during and after injection of CO2. We discuss the results in light of the competing processes of hydrate dissociation, hydrate conversion and secondary hydrate formation. Our results will also contribute to the understanding of effects of temperature and pressure changes leading to dissociation of gas hydrates in ocean and permafrost systems. [1] Deusner C, Bigalke N, Kossel E

  9. Hydraulic jett mixing

    International Nuclear Information System (INIS)

    Ackerman, J.R.

    1989-01-01

    Efficient mixing of reactants into a waste stream has always been a problem in that there has been no mixer capable of combining all the elements of enhanced mixing into a single piece of equipment. Through the development of a mixing system for the mining industry to treat acid mine water containing heavy metals, a versatile new hydraulic jetting static mixer has been developed that has no moving parts and a clean bore with no internal components. This paper reports that the main goal of the development of the hydraulic jett mixer was to reduce the size of the tankage required for an acid mine drainage (AMD) treatment plant through development of a static mixing device that could coincidentally aerate the treatment flow. This process equipment being developed would simultaneously adjust the pH and oxidize the metals allowing formation of the hydroxide sludges required for sedimentation and removal of the metals from the treatment stream. In effect, the device eliminates two reaction tanks, the neutralization/mixing tank and the aeration tank

  10. Critical review of hydraulic modeling on atmospheric heat dissipation

    International Nuclear Information System (INIS)

    Onishi, Y.; Brown, S.M.

    1977-01-01

    Objectives of this study were: to define the useful roles of hydraulic modeling in understanding the predicting atmospheric effects of heat dissipation systems; to assess the state-of-the-art of hydraulic modeling of atmospheric phenomena; to inventory potentially useful existing hydraulic modeling facilities both in the United States and abroad; and to scope hydraulic model studies to assist the assessment of atmospheric effects of nuclear energy centers

  11. Low-power non-volatile spintronic memory: STT-RAM and beyond

    International Nuclear Information System (INIS)

    Wang, K L; Alzate, J G; Khalili Amiri, P

    2013-01-01

    The quest for novel low-dissipation devices is one of the most critical for the future of semiconductor technology and nano-systems. The development of a low-power, universal memory will enable a new paradigm of non-volatile computation. Here we consider STT-RAM as one of the emerging candidates for low-power non-volatile memory. We show different configurations for STT memory and demonstrate strategies to optimize key performance parameters such as switching current and energy. The energy and scaling limits of STT-RAM are discussed, leading us to argue that alternative writing mechanisms may be required to achieve ultralow power dissipation, a necessary condition for direct integration with CMOS at the gate level for non-volatile logic purposes. As an example, we discuss the use of the giant spin Hall effect as a possible alternative to induce magnetization reversal in magnetic tunnel junctions using pure spin currents. Further, we concentrate on magnetoelectric effects, where electric fields are used instead of spin-polarized currents to manipulate the nanomagnets, as another candidate solution to address the challenges of energy efficiency and density. The possibility of an electric-field-controlled magnetoelectric RAM as a promising candidate for ultralow-power non-volatile memory is discussed in the light of experimental data demonstrating voltage-induced switching of the magnetization and reorientation of the magnetic easy axis by electric fields in nanomagnets. (paper)

  12. The effect of hydraulic lift on organic matter decomposition, soil nitrogen cycling, and nitrogen acquisition by a grass species.

    Science.gov (United States)

    Armas, Cristina; Kim, John H; Bleby, Timothy M; Jackson, Robert B

    2012-01-01

    Hydraulic lift (HL) is the passive movement of water through plant roots, driven by gradients in water potential. The greater soil-water availability resulting from HL may in principle lead to higher plant nutrient uptake, but the evidence for this hypothesis is not universally supported by current experiments. We grew a grass species common in North America in two-layer pots with three treatments: (1) the lower layer watered, the upper one unwatered (HL), (2) both layers watered (W), and (3) the lower layer watered, the upper one unwatered, but with continuous light 24 h a day to limit HL (no-HL). We inserted ingrowth cores filled with enriched-nitrogen organic matter ((15)N-OM) in the upper layer and tested whether decomposition, mineralization and uptake of (15)N were higher in plants performing HL than in plants without HL. Soils in the upper layer were significantly wetter in the HL treatment than in the no-HL treatment. Decomposition rates were similar in the W and HL treatments and lower in no-HL. On average, the concentration of NH(4)(+)-N in ingrowth cores was highest in the W treatment, and NO(3)(-)-N concentrations were highest in the no-HL treatment, with HL having intermediate values for both, suggesting differential mineralization of organic N among treatments. Aboveground biomass, leaf (15)N contents and the (15)N uptake in aboveground tissues were higher in W and HL than in no-HL, indicating higher nutrient uptake and improved N status of plants performing HL. However, there were no differences in total root nitrogen content or (15)N uptake by roots, indicating that HL affected plant allocation of acquired N to photosynthetic tissues. Our evidence for the role of HL in organic matter decomposition and nutrient cycling suggests that HL could have positive effects on plant nutrient dynamics and nutrient turnover.

  13. Effect of hydraulic retention time on the biodegradation of complex phenolic mixture from simulated coal wastewater in hybrid UASB reactors

    Energy Technology Data Exchange (ETDEWEB)

    Ramakrishnan, Anushuya [Centre for Environmental Science and Engineering, Indian Institute of Technology Bombay, Powai, Mumbai 400076 (India); Gupta, Sudhir Kumar [Centre for Environmental Science and Engineering, Indian Institute of Technology Bombay, Powai, Mumbai 400076 (India)], E-mail: skgupta@iitb.ac.in

    2008-05-01

    This study describes the feasibility of anaerobic treatment of complex phenolics mixture from a simulated synthetic coal wastewater using four identical 13.5 L (effective volume) bench scale hybrid up-flow anaerobic sludge blanket (HUASB) (combining UASB + anaerobic filter) reactors at four different hydraulic retention times (HRT) under mesophilic (27 {+-} 5 {sup o}C) conditions. Synthetic coal wastewater with an average chemical oxygen demand (COD) of 2240 mg/L and phenolics concentration of 752 mg/L was used as substrate. The phenolics contained phenol (490 mg/L); m-, o-, p-cresols (123.0, 58.6, 42 mg/L); 2,4-, 2,5-, 3,4- and 3,5-dimethyl phenols (6.3, 6.3, 4.4 and 21.3 mg/L) as major phenolic compounds. The study demonstrated that at optimum HRT, 24 h, and phenolic loading rate of 0.75 g COD/(m{sup 3}-d), the phenolics and COD removal efficiency of the reactors were 96% and 86%, respectively. Bio-kinetic models were applied to data obtained from experimental studies in hybrid UASB reactor. Grau second-order multi-component substrate removal model was best fitted to the hybrid UASB reactor. The second-order substrate removal rate constant (k{sub 2(s)}) was found as 1.72 h{sup -1} for the hybrid reactor treating complex phenolic mixture. Morphological examination of the sludge revealed rod-type Methanothrix-like, cells to be dominant on the surface.

  14. Effect of hydraulic retention time on the biodegradation of complex phenolic mixture from simulated coal wastewater in hybrid UASB reactors

    International Nuclear Information System (INIS)

    Ramakrishnan, Anushuya; Gupta, Sudhir Kumar

    2008-01-01

    This study describes the feasibility of anaerobic treatment of complex phenolics mixture from a simulated synthetic coal wastewater using four identical 13.5 L (effective volume) bench scale hybrid up-flow anaerobic sludge blanket (HUASB) (combining UASB + anaerobic filter) reactors at four different hydraulic retention times (HRT) under mesophilic (27 ± 5 o C) conditions. Synthetic coal wastewater with an average chemical oxygen demand (COD) of 2240 mg/L and phenolics concentration of 752 mg/L was used as substrate. The phenolics contained phenol (490 mg/L); m-, o-, p-cresols (123.0, 58.6, 42 mg/L); 2,4-, 2,5-, 3,4- and 3,5-dimethyl phenols (6.3, 6.3, 4.4 and 21.3 mg/L) as major phenolic compounds. The study demonstrated that at optimum HRT, 24 h, and phenolic loading rate of 0.75 g COD/(m 3 -d), the phenolics and COD removal efficiency of the reactors were 96% and 86%, respectively. Bio-kinetic models were applied to data obtained from experimental studies in hybrid UASB reactor. Grau second-order multi-component substrate removal model was best fitted to the hybrid UASB reactor. The second-order substrate removal rate constant (k 2(s) ) was found as 1.72 h -1 for the hybrid reactor treating complex phenolic mixture. Morphological examination of the sludge revealed rod-type Methanothrix-like, cells to be dominant on the surface

  15. Brackish water for irrigation: IV. effects on yield of maize (zea mays l.) and saturated hydraulic conductivity of soil

    International Nuclear Information System (INIS)

    Abid, M.; Anwar-ur-Hassan; Ghafoor, A.

    2003-01-01

    The experiment was conducted to investigate the effect of brackish water irrigation on fresh biomass yield of maize variety Agati-72 and saturated hydraulic conductivity (HC) of silty clay loam soil. Total 20 treatment combinations having different EC/sub iw/ (0.65, 2.0, 4.0, 6.0 and 7.35 dS m/sup -1/), SAR/sub iw/ (3.95, 9.65, 18.0, 26.35 and 32.04 (mmol L/sup -1)/sup 1/2/) and RSC (0.65, 2.0, 4.0, 6.0 and 7.35 mmol/sub c/ L/sup -1/) were applied to 30 cm x 68 cm undisturbed and disturbed soil columns. Results indicated that biomass yield of maize decreased with an increase in EC/sub iw/ from 0.65 to 7.35 dS m/sup -1/ at coded 0 levels of SAR/sub iw/ and RSC in undisturbed soil. The maize tolerated EC/sub iw/ up to 2.0 dS m/sup-1/ at coded 0 levels of SAR/sub iw/ and RSC in disturbed soil. The SAR/sub iw/ up to 18.0 did not affect the yield of crop at coded 0 levels of EC/sub iw/ for the undisturbed and disturbed soils, respectively. The increase in HC was 48% in undisturbed and 54% in disturbed soils with EC/sub iw/ 7.35 dS m/sup -1/ over EC/sub iw/ 0.65 dS m/sup -1/ coded 0 levels of EC/sub iw/ and RSC. The HC decreased with SAR/sub iw/ and RSC at coded 0 levels of EC/sub iw/ and RSC; EC/sub iw/ and SAR/sub iw/ in both the soil columns. (author)

  16. The effect of restored and native oxbows on hydraulic loads of nutrients and stream water quality

    Science.gov (United States)

    Kalkhoff, Stephen J.; Hubbard, Laura E.; Joseph P.Schubauer-Berigan,

    2016-01-01

    The use of oxbow wetlands has been identified as a potential strategy to reduce nutrient transport from agricultural drainage tiles to streams in Iowa. In 2013 and 2014, a study was conducted in north-central Iowa in a native oxbow in the Lyons Creek watershed and two restored oxbow wetlands in the Prairie Creek watershed (Smeltzer west and Smeltzer east) to assess their effectiveness at reducing nitrogen and phosphorus loads. The tile line inlets carrying agricultural runoff to the oxbows, the outfall from the oxbows, and the surface waters in the streams receiving the outfall water were monitored for discharge and nutrients from February 2013 to September 2015. Smeltzer west and east also had four monitoring wells each, two in the upland and two between the oxbow and Prairie Creek to monitor surface water-groundwater interaction. The Smeltzer west and east oxbow sites also were instrumented to continuously measure the nitrate concentration. Rainfall was measured at one Lyons Creek and one Smeltzer site. Daily mean nitrate-N concentrations in Lyons Creek in 2013 ranged from 11.8 mg/L to 40.9 mg/L, the median daily mean nitrate-N concentration was 33.0 mg/L. Daily mean nitrate-N concentrations in Prairie Creek in 2013 ranged from 0.07 mg/L in August to 32.2 mg/L in June. In 2014, daily mean nitrate-N concentrations in Prairie Creek ranged from 0.17 mg/L in April to 26.7 mg/L in July; the daily mean nitrate-N concentration for the sampled period was 9.78 mg/L. Nutrient load reduction occurred in oxbow wetlands in Lyons and Prairie Creek watersheds in north-central Iowa but efficiency of reduction was variable. Little nutrient reduction occurred in the native Lyons Creek oxbow during 2013. Concentrations of all nutrient constituents were not significantly (P>0.05, Wilcoxon rank sum) different in water discharging from the tile line than in water leaving the Lyons Creek oxbow. A combination of physical features and flow conditions suggest that the residence time of

  17. Uncertainty in hydraulic tests in fractured rock

    International Nuclear Information System (INIS)

    Ji, Sung-Hoon; Koh, Yong-Kwon

    2014-01-01

    Interpretation of hydraulic tests in fractured rock has uncertainty because of the different hydraulic properties of a fractured rock to a porous medium. In this study, we reviewed several interesting phenomena which show uncertainty in a hydraulic test at a fractured rock and discussed their origins and the how they should be considered during site characterisation. Our results show that the estimated hydraulic parameters of a fractured rock from a hydraulic test are associated with uncertainty due to the changed aperture and non-linear groundwater flow during the test. Although the magnitude of these two uncertainties is site-dependent, the results suggest that it is recommended to conduct a hydraulic test with a little disturbance from the natural groundwater flow to consider their uncertainty. Other effects reported from laboratory and numerical experiments such as the trapping zone effect (Boutt, 2006) and the slip condition effect (Lee, 2014) can also introduce uncertainty to a hydraulic test, which should be evaluated in a field test. It is necessary to consider the way how to evaluate the uncertainty in the hydraulic property during the site characterisation and how to apply it to the safety assessment of a subsurface repository. (authors)

  18. Effect of wet-dry cycles on polymer treated bentonite in seawater : swelling ability, hydraulic conductivity and crack analysis

    NARCIS (Netherlands)

    De Camillis, Michela; Di Emidio, Gemmina; Bezuijen, Adam; Verastegui Flores, Daniel; Van Stappen, Jeroen; Cnudde, Veerle

    2017-01-01

    Waste disposal facilities are often isolated by clay liners in order to prevent pollutant migration into the ground. Bentonite is used as barrier material thanks to the low conductivity to water. However, the hydraulic performance may be impaired by contact with aggressive liquids due to cation

  19. La Palabra de Ramón Frediani: Las Retenciones

    Directory of Open Access Journals (Sweden)

    Marcelo Coser

    2008-04-01

    Full Text Available En el marco del programa "Prisma Económico" del Instituto de Economía y Finanzas (IEF, Marcelo Coser, su conductor, consulta al Profesor Ramón Osvaldo Frediani, docente de la asignatura “Economía Regional y Urbana” e investigadordel Instituto. Durante la nota, Ramón Frediani nos da sus conceptos sobre las debatidas retenciones y los propósitos que éstas persiguen, brindando su visión respecto al accionar del Gobierno Nacional.

  20. RAM R-200 - A Portable Ruggedized Radiation Monitoring System

    International Nuclear Information System (INIS)

    Wengrowicz, U.; Mazor, T.; Assido, H.; Kadmon, Y.; Tirosh, D.; Shani, G.

    1999-01-01

    RAM R-200, a new generation of ruggedized portable radiation-monitoring systems, is presented. The system which is a result of interdisciplinary research, was developed at the NRCN in collaboration with Ben-Gurion University. It consists of RAM R-200 - a portable radiation meter, and a variety of external probes for wide range gamma radiation fields and beta-gamma contamination detection and measurement. The meter or each one of the external probes can be used as a portable system or a stand-alone radiation measurement station. All the system's components were specially designed to meet severe environmental conditions

  1. A graphite based STT-RAM cell with reduction in switching current

    International Nuclear Information System (INIS)

    Varghani, Ali; Peiravi, Ali

    2015-01-01

    Spin Transfer Torque Random Access Memory (STT-RAM) is a serious candidate for “universal memory” because of its non-volatility, fast access time, high density, good scalability, high endurance and relatively low power dissipation. However, problems with low write speed and large write current are important existing challenges in STT-RAM design and there is a tradeoff between them and data retention time. In this study, a novel STT-RAM cell structure which uses perfect graphite based Magnetic Tunnel Junction (MTJ) is proposed. First, the cross-section of the structure is selected to be an ellipse of 45 nm and 180 nm dimensions and a six-layer graphite is used as tunnel barrier. By passing a lateral current with a short pulse width (before applying STT current and independent of it) through four middle graphene layers of the tunnel barrier, a 27% reduction in the amplitude of the switching current (for fast switching time of 2 ns) or a 58% reduction in its pulse width is achieved without any reduction in data retention time. Finally, the effect of downscaling of technology on the proposed structure is evaluated. A reduction of 31.6% and 9% in switching current is achieved for 90 and 22 nm cell width respectively by passing sufficient current (100 µA with 0.1 ns pulse width) through the tunnel barrier. Simulations are done using Object Oriented Micro Magnetic Framework (OOMMF). - Highlights: • A new STT-RAM cell structure which uses perfect graphite based MTJ is proposed. • The amplitude of the switching current or its pulsewidth can be reduced without any sacrifice of data retention time. • The proposed design is down-scalable from 90 nm to 22 nm. • Micromagnetic simulations are done with OOMMF

  2. Advantages of Oscillatory Hydraulic Tomography

    Science.gov (United States)

    Kitanidis, P. K.; Bakhos, T.; Cardiff, M. A.; Barrash, W.

    2012-12-01

    Characterizing the subsurface is significant for most hydrogeologic studies, such as those involving site remediation and groundwater resource explo¬ration. A variety of hydraulic and geophysical methods have been developed to estimate hydraulic conductivity and specific storage. Hydraulic methods based on the analysis of conventional pumping tests allow the estimation of conductivity and storage without need for approximate petrophysical relations, which is an advantage over most geophysical methods that first estimate other properties and then infer values of hydraulic parameters. However, hydraulic methods have the disadvantage that the head-change signal decays with distance from the pumping well and thus becomes difficult to separate from noise except in close proximity to the source. Oscillatory hydraulic tomography (OHT) is an emerging technology to im¬age the subsurface. This method utilizes the idea of imposing sinusoidally varying pressure or discharge signals at several points, collecting head observations at several other points, and then processing these data in a tomographic fashion to estimate conductivity and storage coefficients. After an overview of the methodology, including a description of the most important potential advantages and challenges associated with this approach, two key promising features of the approach will be discussed. First, the signal at an observation point is orthogonal to and thus can be separated from nuisance inputs like head fluctuation from production wells, evapotranspiration, irrigation, and changes in the level of adjacent streams. Second, although the signal amplitude may be weak, one can extract the phase and amplitude of the os¬cillatory signal by collecting measurements over a longer time, thus compensating for the effect of large distance through longer sampling period.

  3. A graphite based STT-RAM cell with reduction in switching current

    Science.gov (United States)

    Varghani, Ali; Peiravi, Ali

    2015-10-01

    Spin Transfer Torque Random Access Memory (STT-RAM) is a serious candidate for "universal memory" because of its non-volatility, fast access time, high density, good scalability, high endurance and relatively low power dissipation. However, problems with low write speed and large write current are important existing challenges in STT-RAM design and there is a tradeoff between them and data retention time. In this study, a novel STT-RAM cell structure which uses perfect graphite based Magnetic Tunnel Junction (MTJ) is proposed. First, the cross-section of the structure is selected to be an ellipse of 45 nm and 180 nm dimensions and a six-layer graphite is used as tunnel barrier. By passing a lateral current with a short pulse width (before applying STT current and independent of it) through four middle graphene layers of the tunnel barrier, a 27% reduction in the amplitude of the switching current (for fast switching time of 2 ns) or a 58% reduction in its pulse width is achieved without any reduction in data retention time. Finally, the effect of downscaling of technology on the proposed structure is evaluated. A reduction of 31.6% and 9% in switching current is achieved for 90 and 22 nm cell width respectively by passing sufficient current (100 μA with 0.1 ns pulse width) through the tunnel barrier. Simulations are done using Object Oriented Micro Magnetic Framework (OOMMF).

  4. Interaction of milk proteins and Binder of Sperm (BSP) proteins from boar, stallion and ram semen.

    Science.gov (United States)

    Plante, Geneviève; Lusignan, Marie-France; Lafleur, Michel; Manjunath, Puttaswamy

    2015-08-15

    Mammalian semen contains a family of closely related proteins known as Binder of SPerm (BSP proteins) that are added to sperm at ejaculation. BSP proteins extract lipids from the sperm membrane thereby extensively modifying its composition. These changes can ultimately be detrimental to sperm storage. We have demonstrated that bovine BSP proteins interact with major milk proteins and proposed that this interaction could be the basis of sperm protection by milk extenders. In the present study, we investigated if homologous BSP proteins present in boar, stallion and ram seminal plasma display a similar affinity for the milk proteins in order to assess whether the mechanism of sperm protection by milk for these species could be general. Skim milk was incubated with seminal plasma proteins (boar, stallion and ram), chromatographed on a Sepharose CL-4B column and protein fractions were analyzed by immunoblotting. Boar, stallion and ram BSP proteins displayed affinity for a milk protein fraction (F1) mainly composed of α-lactalbumin, β-lactoglobulin, and κ-casein. They also had affinity for another milk protein fraction (F2) composed mostly of casein micelles. However, stallion BSP showed higher affinity for the fraction (F1). These results further extend our view that the association of BSP proteins with milk proteins could be a general feature of the mechanism of mammalian sperm protection by milk to prevent detrimental effect of prolonged exposure of sperm to seminal plasma.

  5. Development of neutronic models for the thermal hydraulics coupling of the MSFR and the calculation of effective kinetic parameters

    International Nuclear Information System (INIS)

    Laureau, Axel

    2015-01-01

    In this PhD thesis, we describe the development of innovative neutronic models for their coupling with thermal hydraulics such that they combine precision and reasonable computational times. One of the main cases where this method is applied is the Molten Salt Fast Reactor (MSFR) whose combines a fast neutron spectrum with a thorium cycle. In this fourth generation reactor, the motion of the delayed neutron precursors and the associated phenomena have to be taken into account due to the liquid fuel circulation. The starting point for these developments was the preliminary design of this type of system where a dedicated multi-physical representation was needed to study the reactor performance in steady and transient conditions. As a first step, a stationary coupling was developed. A neutronic model based on a stochastic approach was associated to a CFD (Computational Fluid Dynamics) code to solve the Navier Stokes equations for turbulent flows and the transport of the delayed neutron precursors. The impact of this precursor motion is taken into account by reconstructing the prompt shower that they generate. This approach, called by shower, views the critical reactor as a prompt subcritical reactor that amplifies a source of delayed neutrons. A second step consisted in developing a neutronic model based on a time dependent version of the fission matrices (Transient Fission Matrix or TFM) so as to enable reactor transient studies. With the TFM model, an initial computation of the matrices with a stochastic code (MCNP, SERPENT) allows the characterization of the global spatial and time dependent neutronic response of the reactor with a precision close to that of a Monte Carlo calculation. The information thus obtained is then used to calculate transients, while retaining the advantage of reduced computational time. The TFM model, which can be used for various system concepts, also allows the evaluation of effective kinetic parameters such as the effective fraction of

  6. Thermally Actuated Hydraulic Pumps

    Science.gov (United States)

    Jones, Jack; Ross, Ronald; Chao, Yi

    2008-01-01

    Thermally actuated hydraulic pumps have been proposed for diverse applications in which direct electrical or mechanical actuation is undesirable and the relative slowness of thermal actuation can be tolerated. The proposed pumps would not contain any sliding (wearing) parts in their compressors and, hence, could have long operational lifetimes. The basic principle of a pump according to the proposal is to utilize the thermal expansion and contraction of a wax or other phase-change material in contact with a hydraulic fluid in a rigid chamber. Heating the chamber and its contents from below to above the melting temperature of the phase-change material would cause the material to expand significantly, thus causing a substantial increase in hydraulic pressure and/or a substantial displacement of hydraulic fluid out of the chamber. Similarly, cooling the chamber and its contents from above to below the melting temperature of the phase-change material would cause the material to contract significantly, thus causing a substantial decrease in hydraulic pressure and/or a substantial displacement of hydraulic fluid into the chamber. The displacement of the hydraulic fluid could be used to drive a piston. The figure illustrates a simple example of a hydraulic jack driven by a thermally actuated hydraulic pump. The pump chamber would be a cylinder containing encapsulated wax pellets and containing radial fins to facilitate transfer of heat to and from the wax. The plastic encapsulation would serve as an oil/wax barrier and the remaining interior space could be filled with hydraulic oil. A filter would retain the encapsulated wax particles in the pump chamber while allowing the hydraulic oil to flow into and out of the chamber. In one important class of potential applications, thermally actuated hydraulic pumps, exploiting vertical ocean temperature gradients for heating and cooling as needed, would be used to vary hydraulic pressures to control buoyancy in undersea research

  7. Study on Characteristics of Hydraulic Servo System for Force Control of Hydraulic Robots

    International Nuclear Information System (INIS)

    Kim, Hyo-gon; Han, Changsoo; Lee, Jong-won; Park, Sangdeok

    2015-01-01

    Because a hydraulic actuator has high power and force densities, this allows the weight of the robot's limbs to be reduced. This allows for good dynamic characteristics and high energy efficiency. Thus, hydraulic actuators are used in some exoskeleton robots and quadrupedal robots that require high torque. Force control is useful for robot compliance with a user or environment. However, force control of a hydraulic robot is difficult because a hydraulic servo system is highly nonlinear from a control perspective. In this study, a nonlinear model was used to develop a simulation program for a hydraulic servo system consisting of a servo valve, transmission lines, and a cylinder. The problems and considerations with regard to the force control performance for a hydraulic servo system were investigated. A force control method using the nonlinear model was proposed, and its effect was evaluated with the simulation program

  8. Study on Characteristics of Hydraulic Servo System for Force Control of Hydraulic Robots

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyo-gon; Han, Changsoo [Hanyang University, Seoul (Korea, Republic of); Lee, Jong-won [Korea University of Science and Technology, Seoul (Korea, Republic of); Park, Sangdeok [Korea Institute of Industrial Technology, Seoul (Korea, Republic of)

    2015-02-15

    Because a hydraulic actuator has high power and force densities, this allows the weight of the robot's limbs to be reduced. This allows for good dynamic characteristics and high energy efficiency. Thus, hydraulic actuators are used in some exoskeleton robots and quadrupedal robots that require high torque. Force control is useful for robot compliance with a user or environment. However, force control of a hydraulic robot is difficult because a hydraulic servo system is highly nonlinear from a control perspective. In this study, a nonlinear model was used to develop a simulation program for a hydraulic servo system consisting of a servo valve, transmission lines, and a cylinder. The problems and considerations with regard to the force control performance for a hydraulic servo system were investigated. A force control method using the nonlinear model was proposed, and its effect was evaluated with the simulation program.

  9. Prevalence of gastrointestinal parasites of rams brought into ...

    African Journals Online (AJOL)

    In an effort to gain a better understanding into the role played by food animals in the epidemiology of gastrointestinal parasites, we assessed the prevalence of gastrointestinal parasites in different breeds of rams brought into Abeokuta during a festive season by ... The only protozoan parasite identified was Eimeria spp.

  10. Timber management planning with timber ram and goal programming

    Science.gov (United States)

    Richard C. Field

    1978-01-01

    By using goal programming to enhance the linear programming of Timber RAM, multiple decision criteria were incorporated in the timber management planning of a National Forest in the southeastern United States. Combining linear and goal programming capitalizes on the advantages of the two techniques and produces operationally feasible solutions. This enhancement may...

  11. Minsk ja RAM 7 / Evelyn Müürsepp

    Index Scriptorium Estoniae

    Müürsepp, Evelyn

    2005-01-01

    Minskis toimunud RAM 7-st (Reapproaching New Media. Models of Collaboration / Ümberhinnates uut meediat. Koostöömudelid". Korraldajad Tatjana Dushina ja Denis Romanovski üritavad luua uue meedia keskust Valgevene kunstiakadeemiasse. Eestit esindasid Evelin Müürsepp ja John Grzinich (modereeris vabade ülikoolide kursust). Osalemisest fotomängus "FotoOhota"

  12. Performance and carcass characteristics of Yankasa ram fed with ...

    African Journals Online (AJOL)

    Administrator

    2011-05-30

    May 30, 2011 ... were randomly assign to the 5 dietary treatment with four rams per treatment. ... estimate dry matter intake (g/d /W 0.7 kg), daily mean life weight gain ... 1.78%) and rib eye area (6.06 and 8.29) which were obtained from the ...

  13. Measurement and analysis of the water hammer in ram pump

    Indian Academy of Sciences (India)

    This paper presents the results of experimental research of the phenomena occurring in water ram during a single cycle of its operation. Apart from a brief introduction and description of the test stand and data recording system, the work includes a broad interpretation of the obtained results. Based on the pressure ...

  14. Detecting danger labels with RAM-based neural networks

    DEFF Research Database (Denmark)

    Jørgensen, T.M.; Christensen, S.S.; Andersen, A.W.

    1996-01-01

    An image processing system for the automatic location of danger labels on the back of containers is presented. The system uses RAM-based neural networks to locate and classify labels after a pre-processing step involving specially designed non-linear edge filters and RGB-to-HSV conversion. Result...

  15. The neurobiology of sexual partner preferences in rams.

    Science.gov (United States)

    Roselli, Charles E; Stormshak, Fred

    2009-05-01

    The question of what causes a male animal to seek out and choose a female as opposed to another male mating partner is unresolved and remains an issue of considerable debate. The most developed biologic theory is the perinatal organizational hypothesis, which states that perinatal hormone exposure mediates sexual differentiation of the brain. Numerous animal experiments have assessed the contribution of perinatal testosterone and/or estradiol exposure to the development of a male-typical mate preference, but almost all have used hormonally manipulated animals. In contrast, variations in sexual partner preferences occur spontaneously in domestic rams, with as many as 8% of the population exhibiting a preference for same-sex mating partners (male-oriented rams). Thus, the domestic ram is an excellent experimental model to study possible links between fetal neuroendocrine programming of neural mechanisms and adult sexual partner preferences. In this review, we present an overview of sexual differentiation in relation to sexual partner preferences. We then summarize results that test the relevance of the organizational hypothesis to expression of same-sex sexual partner preferences in rams. Finally, we demonstrate that the sexual differentiation of brain and behavior in sheep does not depend critically on aromatization of testosterone to estradiol.

  16. A realization of the RAM digital filter. [Random Access Memory

    Science.gov (United States)

    Zohar, S.

    1976-01-01

    The digital filtering algorithm of W. D. Little, which employs a large RAM to obtain high speed, is implemented in a simple hardware configuration. The nonrecursive version of this filter is compared to the counting digital filter and found to be competitive for low-order filters up to order 7 (8 coefficients).

  17. The sexual cycle of the Impala ram Aepyceros melampus Lichtenstein

    African Journals Online (AJOL)

    The sexual cycle of the Impala ram Aepyceros melampus Lichtenstein. J.D. Skinner. Abstract. No Abstract. Full Text: EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT · AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for Authors ...

  18. The Neurobiology of Sexual Partner Preferences in Rams

    Science.gov (United States)

    Roselli, Charles E.; Stormshak, Fred

    2009-01-01

    The question of what causes a male animal to seek out and choose a female as opposed to another male mating partner is unresolved and remains an issue of considerable debate. The most developed biologic theory is the perinatal organizational hypothesis, which states that perinatal hormone exposure mediates sexual differentiation of the brain. Numerous animal experiments have assessed the contribution of perinatal testosterone and/or estradiol exposure to the development of a male-typical mate preference, but almost all have used hormonally manipulated animals. In contrast, variations in sexual partner preferences occur spontaneously in domestic rams, with as many as 8% of the population exhibiting a preference for same-sex mating partners (male-oriented rams). Thus, the domestic ram is an excellent experimental model to study possible links between fetal neuroendocrine programming of neural mechanisms and adult sexual partner preferences. In this review, we present an overview of sexual differentiation in relation to sexual partner preferences. We then summarize results that test the relevance of the organizational hypothesis to expression of same-sex sexual partner preferences in rams. Finally, we demonstrate that the sexual differentiation of brain and behavior in sheep do not depend critically on aromatization of testosterone to estradiol. PMID:19446078

  19. Semen characteristics of pubertal Yankasa rams fed Zingiber ...

    African Journals Online (AJOL)

    Ginger (Zingiber officinale) is consumed by humans and has been reported to possess medicinal uses. It possesses androgenic property with significant increase on male reproductive parameters. This study assessed the reproductive performance of Yankasa rams fed diets supplemented with different levels of ginger ...

  20. Reproductive indices of Merino rams fed sun-cured Leucaena ...

    African Journals Online (AJOL)

    Reproductive indices of Merino rams fed sun-cured Leucaena leucocephala forage. I.V. Nsahlai, B.K. Byebwa, M.L.K. Bonsi. Abstract. (South African J of Animal Science, 2000, 30, Supplement 1: 111-112). Full Text: EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT.

  1. Architecture of the sperm whale forehead facilitates ramming combat

    Directory of Open Access Journals (Sweden)

    Olga Panagiotopoulou

    2016-04-01

    Full Text Available Herman Melville’s novel Moby Dick was inspired by historical instances in which large sperm whales (Physeter macrocephalus L. sank 19th century whaling ships by ramming them with their foreheads. The immense forehead of sperm whales is possibly the largest, and one of the strangest, anatomical structures in the animal kingdom. It contains two large oil-filled compartments, known as the “spermaceti organ” and “junk,” that constitute up to one-quarter of body mass and extend one-third of the total length of the whale. Recognized as playing an important role in echolocation, previous studies have also attributed the complex structural configuration of the spermaceti organ and junk to acoustic sexual selection, acoustic prey debilitation, buoyancy control, and aggressive ramming. Of these additional suggested functions, ramming remains the most controversial, and the potential mechanical roles of the structural components of the spermaceti organ and junk in ramming remain untested. Here we explore the aggressive ramming hypothesis using a novel combination of structural engineering principles and probabilistic simulation to determine if the unique structure of the junk significantly reduces stress in the skull during quasi-static impact. Our analyses indicate that the connective tissue partitions in the junk reduce von Mises stresses across the skull and that the load-redistribution functionality of the former is insensitive to moderate variation in tissue material parameters, the thickness of the partitions, and variations in the location and angle of the applied load. Absence of the connective tissue partitions increases skull stresses, particularly in the rostral aspect of the upper jaw, further hinting of the important role the architecture of the junk may play in ramming events. Our study also found that impact loads on the spermaceti organ generate lower skull stresses than an impact on the junk. Nevertheless, whilst an impact on the

  2. Prenatal programming of sexual partner preference: the ram model.

    Science.gov (United States)

    Roselli, C E; Stormshak, F

    2009-03-01

    In our laboratory, the domestic ram is used as an experimental model to study the early programming of neural mechanisms underlying same-sex partner preference. This interest developed from the observation that approximately 8% of domestic rams are sexually attracted to other rams (male-oriented) in contrast to the majority of rams that are attracted to oestrous ewes (female-oriented). One prominent feature of sexual differentiation in many species is the presence of a sexually dimorphic nucleus (SDN) in the preoptic/anterior hypothalamus that is larger in males than in females. Lesion studies in rats and ferrets implicate the SDN in the expression of sexual preferences. We discovered an ovine SDN (oSDN) in the preoptic/anterior hypothalamus that is smaller in male- than in female-oriented rams and similar in size to the oSDN of ewes. Neurones of the oSDN show abundant aromatase expression that is also reduced in male-oriented compared to female-oriented rams. This observation suggests that sexual partner preferences are neurologically hard-wired and could be influenced by hormones. Aromatase-containing neurones constitute a nascent oSDN as early as day 60 of gestation, which becomes sexually dimorphic by day 135 of gestation when it is two-fold larger in males than in females. Exposure of fetal female lambs to exogenous testosterone from days 30-90 of gestation resulted in a masculinised oSDN. These data demonstrate that the oSDN develops prenatally and may influence adult sexual preferences. Surprisingly, inhibition of aromatase activity in the brain of ram foetuses during the critical period did not interfere with defeminisation of adult sexual partner preference or oSDN volume. These results fail to support an essential role for neural aromatase in the sexual differentiation of sheep brain and behaviour. Thus, we propose that oSDN morphology and male-typical partner preferences may instead be programmed through an androgen receptor mechanism not involving

  3. Architecture of the sperm whale forehead facilitates ramming combat.

    Science.gov (United States)

    Panagiotopoulou, Olga; Spyridis, Panagiotis; Mehari Abraha, Hyab; Carrier, David R; Pataky, Todd C

    2016-01-01

    Herman Melville's novel Moby Dick was inspired by historical instances in which large sperm whales (Physeter macrocephalus L.) sank 19th century whaling ships by ramming them with their foreheads. The immense forehead of sperm whales is possibly the largest, and one of the strangest, anatomical structures in the animal kingdom. It contains two large oil-filled compartments, known as the "spermaceti organ" and "junk," that constitute up to one-quarter of body mass and extend one-third of the total length of the whale. Recognized as playing an important role in echolocation, previous studies have also attributed the complex structural configuration of the spermaceti organ and junk to acoustic sexual selection, acoustic prey debilitation, buoyancy control, and aggressive ramming. Of these additional suggested functions, ramming remains the most controversial, and the potential mechanical roles of the structural components of the spermaceti organ and junk in ramming remain untested. Here we explore the aggressive ramming hypothesis using a novel combination of structural engineering principles and probabilistic simulation to determine if the unique structure of the junk significantly reduces stress in the skull during quasi-static impact. Our analyses indicate that the connective tissue partitions in the junk reduce von Mises stresses across the skull and that the load-redistribution functionality of the former is insensitive to moderate variation in tissue material parameters, the thickness of the partitions, and variations in the location and angle of the applied load. Absence of the connective tissue partitions increases skull stresses, particularly in the rostral aspect of the upper jaw, further hinting of the important role the architecture of the junk may play in ramming events. Our study also found that impact loads on the spermaceti organ generate lower skull stresses than an impact on the junk. Nevertheless, whilst an impact on the spermaceti organ would

  4. History of the 185-/189-D thermal hydraulics laboratory and its effects on reactor operations at the Hanford Site

    International Nuclear Information System (INIS)

    Gerber, M.S.

    1994-09-01

    The 185-D deaeration building and the 189-D refrigeration building were constructed at Hanford during 1943 and 1944. Both buildings were constructed as part of the influent water cooling system for D reactor. The CMS studies eliminated the need for 185-D function. Early gains in knowledge ended the original function of the 189-D building mission. In 1951, 185-D and 189-D were converted to a thermal-hydraulic laboratory. The experiments held in the thermal-hydraulic lab lead to historic changes in Hanford reactor operations. In late 1951, the exponential physics experiments were moved to the 189-D building. In 1958, new production reactor experiments were begun in 185/189-D. In 1959, Plutonium Recycle Test Reactor experiments were added to the 185/189-D facility. By 1960, the 185/189-D thermal hydraulics laboratory was one of the few full service facilities of its type in the nation. During the years 1961--1963 tests continued in the facility in support of existing reactors, new production reactors, and the Plutonium Recycle Test Reactor. In 1969, Fast Flux Test Facility developmental testings began in the facility. Simulations in 185/189-D building aided in the N Reactor repairs in the 1980's. In 1994 the facility was nominated to the National Register of Historic Places, because of its pioneering role over many years in thermal hydraulics, flow studies, heat transfer, and other reactor coolant support work. During 1994 and 1995 it was demolished in the largest decontamination and decommissioning project thus far in Hanford Site history

  5. Hydraulic conductivity of rock fractures

    International Nuclear Information System (INIS)

    Zimmerman, R.W.; Bodvarsson, G.S.

    1994-10-01

    Yucca Mountain, Nevada contains numerous geological units that are highly fractured. A clear understanding of the hydraulic conductivity of fractures has been identified as an important scientific problem that must be addressed during the site characterization process. The problem of the flow of a single-phase fluid through a rough-walled rock fracture is discussed within the context of rigorous fluid mechanics. The derivation of the cubic law is given as the solution to the Navier-Stokes equations for flow between smooth, parallel plates, the only fracture geometry that is amenable to exact treatment. The various geometric and kinetic conditions that are necessary in order for the Navier-Stokes equations to be replaced by the more tractable lubrication or Hele-Shaw equations are studied and quantified. Various analytical and numerical results are reviewed pertaining to the problem of relating the effective hydraulic aperture to the statistics of the aperture distribution. These studies all lead to the conclusion that the effective hydraulic aperture is always less than the mean aperture, by a factor that depends on the ratio of the mean value of the aperture to its standard deviation. The tortuosity effect caused by regions where the rock walls are in contact with each other is studied using the Hele-Shaw equations, leading to a simple correction factor that depends on the area fraction occupied by the contact regions. Finally, the predicted hydraulic apertures are compared to measured values for eight data sets from the literature for which aperture and conductivity data were available on the same fracture. It is found that reasonably accurate predictions of hydraulic conductivity can be made based solely on the first two moments of the aperture distribution function, and the proportion of contact area. 68 refs

  6. Digital switched hydraulics

    Science.gov (United States)

    Pan, Min; Plummer, Andrew

    2018-06-01

    This paper reviews recent developments in digital switched hydraulics particularly the switched inertance hydraulic systems (SIHSs). The performance of SIHSs is presented in brief with a discussion of several possible configurations and control strategies. The soft switching technology and high-speed switching valve design techniques are discussed. Challenges and recommendations are given based on the current research achievements.

  7. Hydraulic Structures : Caissons

    NARCIS (Netherlands)

    Voorendt, M.Z.; Molenaar, W.F.; Bezuyen, K.G.

    These lecture notes on caissons are part of the study material belonging to the course 'Hydraulic Structures 1' (code CTB3355), part of the Bachelor of Science education and the Hydraulic Engineering track of the Master of Science education for civil engineering students at Delft University of

  8. Effect of hydraulic retention time on hydrodynamic behavior of anaerobic-aerobic fixed bed reactor treating cattle slaughterhouse effluent

    Directory of Open Access Journals (Sweden)

    Daiane Cristina de Freitas

    2017-09-01

    Full Text Available The study of the hydrodynamic behavior in reactors provides characteristics of the flow regime and its anomalies that can reduce biological processes efficiency due to the decrease of the useful volume and the hydraulic retention time required for the performance of microbial activity. In this study, the hydrodynamic behavior of an anaerobic-aerobic fixed bed reactor, operated with HRT (hydraulic retention time of 24, 18 and 12 hours, was evaluated in the treatment of raw cattle slaughterhouse wastewater. Polyurethane foam and expanded clay were used as support media for biomass immobilization. Experimental data of pulse type stimulus-response assays were performed with eosin Y and bromophenol blue, and adjusted to the single-parameter theoretical models of dispersion and N-continuous stirred tank reactors in series (N-CSTR. N-CSTR model presented the best adjustment for the HRT and tracers evaluated. RDT (residence time distribution curves obtained with N-CSTR model in the assays with bromophenol blue resulted in better adjustment compared to the eosin Y. The predominant flow regime in AAFBR (anaerobic aerobic fixed bed reactor is the N-CSTR in series, as well as the existence of preferential paths and hydraulic short-circuiting.

  9. Effectiveness Using Circular Fibre Steel Flap Gate As a Control Structure Towards the Hydraulic Characteristics in Open Channel

    Science.gov (United States)

    Adib, M. R. M.; Amirza, A. R. M.; Wardah, T.; Junaidah, A.

    2016-07-01

    Hydraulic control gate structure plays an important role in regulating the flow of water in river, canal or water reservoir. One of the most appropriate structures in term of resolving the problem of flood occured is the construction of circular fibre steel flap gate. Therefore, an experiment has been conducted by using an open channel model at laboratory. In this case, hydraulic jump and backwater were the method to determined the hydraulic characteristics of circular fibre steel flap gate in an open channel model. From the experiment, the opening angle of flap gate can receive discharges with the highest flow rate of 0.035 m3/s with opening angle was 47°. The type of jump that occurs at the slope of 1/200 for a distance of 5.0 m is a standing jump or undulating wave. The height of the backwater can be identified based on the differences of specific force which is specific force before jump, F1 and specific force after jump, F2 from the formation of backwater. Based on the research conducted, the tendency of incident backwater wave occurred was high in every distance of water control location from water inlet is flap slope and the slope of 1/300 which is 0.84 m/s and 0.75 m/s of celerity in open channel model.

  10. Vibration of hydraulic machinery

    CERN Document Server

    Wu, Yulin; Liu, Shuhong; Dou, Hua-Shu; Qian, Zhongdong

    2013-01-01

    Vibration of Hydraulic Machinery deals with the vibration problem which has significant influence on the safety and reliable operation of hydraulic machinery. It provides new achievements and the latest developments in these areas, even in the basic areas of this subject. The present book covers the fundamentals of mechanical vibration and rotordynamics as well as their main numerical models and analysis methods for the vibration prediction. The mechanical and hydraulic excitations to the vibration are analyzed, and the pressure fluctuations induced by the unsteady turbulent flow is predicted in order to obtain the unsteady loads. This book also discusses the loads, constraint conditions and the elastic and damping characters of the mechanical system, the structure dynamic analysis, the rotor dynamic analysis and the system instability of hydraulic machines, including the illustration of monitoring system for the instability and the vibration in hydraulic units. All the problems are necessary for vibration pr...

  11. 水力冲孔有效影响半径数值模拟%Numerical Simulation on Effective Influence Radius of Hydraulic Flushing Borehole

    Institute of Scientific and Technical Information of China (English)

    魏建平; 刘英振; 王登科; 温志辉; 李向楠

    2012-01-01

    根据力学平衡方程和质量守恒定律及煤层渗透率、孔隙率、煤岩体积应变等参数的关系,建立了煤层底板巷水力冲孔气固耦合方程。通过模拟不同出煤量的水力冲孔有效影响半径变化,得出水力冲孔有效影响半径随冲出煤量和抽放时间的增加而增加。当冲出煤量为1 t/m时,有效影响半径为5.8 m,卸压增透效果十分理想。%According to the relationships among mechanics balance equation,the law of conservation of mass,permeability of coal seam,porosity,volume strain of coal,the gas-solid coupled equation of hydraulic flushing borehole in the coal seam floor is established.By simulating the changes of effective influence radius of hydraulic flushing borehole at different coal output,it obtains that the effective influence radius of hydraulic flushing borehole is increasing as the amount increasing of overflow coal and prolonging of drainage time.When the amount of overflow coal is 1t/m,effective influence radius is 5.8 m,the effects of pressure relief and antireflection are very good.

  12. Handbook of hydraulic fluid technology

    CERN Document Server

    Totten, George E

    2011-01-01

    ""The Handbook of Hydraulic Fluid Technology"" serves as the foremost resource for designing hydraulic systems and for selecting hydraulic fluids used in engineering applications. Featuring new illustrations, data tables, as well as practical examples, this second edition is updated with essential information on the latest hydraulic fluids and testing methods. The detailed text facilitates unparalleled understanding of the total hydraulic system, including important hardware, fluid properties, and hydraulic lubricants. Written by worldwide experts, the book also offers a rigorous overview of h

  13. Effects of age-related increases in sapwood area, leaf area, and xylem conductivity on height-related hydraulic costs in two contrasting coniferous species

    Science.gov (United States)

    Jean-Christophe Domec; Barbara Lachenbruch; Michele L. Pruyn; Rachel Spicer

    2012-01-01

    Introduction: Knowledge of vertical variation in hydraulic parameters would improve our understanding of individual trunk functioning and likely have important implications for modeling water movement to the leaves. Specifically, understanding how foliage area (Al), sapwood area (As), and hydraulic specific...

  14. Identification of sexually low-response rams using a libido test and ...

    African Journals Online (AJOL)

    higher levels of sex-like behaviour with their pen mates. (monosexual groups) during rearing than did normal rams. These workers thus suggested that the poor performance of such rams when exposed to an oestrous ewe was due to their inability to interpret sexual cues correctly. Working with. Karakul rams, Le Roux and ...

  15. Hydraulic characterization of " Furcraea andina

    Science.gov (United States)

    Rivera-Velasquez, M. F.; Fallico, C.; Molinari, A.; Santillan, P.; Salazar, M.

    2012-04-01

    The present level of pollution, increasingly involving groundwaters, constitutes a serious risk for environment and human health. Therefore the remediation of saturated and unsaturated soils, removing pollutant materials through innovative and economic bio-remediation techniques is more frequently required. Recent studies on natural fiber development have shown the effectiveness of these fibers for removal of some heavy metals, due to the lignin content in the natural fibers which plays an important role in the adsorption of metal cations (Lee et al., 2004; Troisi et al., 2008; C. Fallico, 2010). In the context of remediation techniques for unsaturated and/or saturated zone, an experimental approach for the hydraulic characterization of the "Furcraea andina" (i.e., Cabuya Blanca) fiber was carried out. This fiber is native to Andean regions and grows easily in wild or cultivated form in the valleys and hillsides of Colombia, Ecuador, and Peru. Fibers of "Furcraea andina" were characterized by experimental tests to determine their hydraulic conductivity or permeability and porosity in order to use this medium for bioremediation of contaminated aquifer exploiting the physical, chemical and microbial capacity of natural fiber in heavy metal adsorption. To evaluate empirically the hydraulic conductivity, laboratory tests were carried out at constant head specifically on the fibers manually extracted. For these tests we used a flow cell (used as permeameter), containing the "Furcraea andina" fibers to be characterized, suitably connected by a tygon pipe to a Marriott's bottle, which had a plastic tube that allow the adjustment of the hydraulic head for different tests to a constant value. By this experiment it was also possible to identify relationships that enable the estimation of permeability as a function of density, i.e. of the compaction degree of the fibers. Our study was carried out for three values of hydraulic head (H), namely 10, 18, and 25 cm and for each

  16. Temporal concentrations of cortisol and LH in virgin ewes acutely exposed to rams during the transition into the breeding season.

    Science.gov (United States)

    McCosh, R B; Berry, E M; Wehrman, M E; Redden, R R; Hallford, D M; Berardinelli, J G

    2015-03-01

    The objectives of this study were to determine if exposing seasonally anovular ewes to rams would alter patterns of cortisol concentrations, and if these changes are associated with changes in characteristics of LH concentrations. Seasonally anestrous ewes were assigned to be exposed to rams (RE; n=11) or wethers (NE; n=12). Blood samples were collected at 15-min intervals beginning 120 min before introduction of males (time=0 min), and continued for 360 min after male exposure. Characteristics of cortisol and LH concentrations included: mean and baseline concentrations, pulse amplitude, duration, frequency, and time to first pulse. Mean and baseline cortisol concentrations, and cortisol pulse amplitude, frequency, and time to first pulse after male exposure did not differ between RE and NE ewes. Cortisol pulse duration was longer (Pewes than in NE ewes. Mean LH and LH pulse amplitude, duration, and time to first pulse after male exposure did not differ between RE and NE ewes. Baseline LH concentrations and LH pulse frequency were greater (Pewes. In RE ewes, but not NE ewes, LH pulse frequency tended to increase (P=0.06) as pulse frequency of cortisol decreased. In conclusion, exposing ewes to mature rams during the transition into the breeding season increased LH pulse frequency which hastened ovulatory activity. However, the results do not support the hypothesis that changes in cortisol concentrations plays a significant role in the 'ram effect'. Copyright © 2015 Elsevier B.V. All rights reserved.

  17. Experimental Results and Issues on Equalization for Nonlinear Memory Channel: Pre-Cursor Enhanced Ram-DFE Canceler

    Science.gov (United States)

    Yuan, Lu; LeBlanc, James

    1998-01-01

    This thesis investigates the effects of the High Power Amplifier (HPA) and the filters over a satellite or telemetry channel. The Volterra series expression is presented for the nonlinear channel with memory, and the algorithm is based on the finite-state machine model. A RAM-based algorithm operating on the receiver side, Pre-cursor Enhanced RAM-FSE Canceler (PERC) is developed. A high order modulation scheme , 16-QAM is used for simulation, the results show that PERC provides an efficient and reliable method to transmit data on the bandlimited nonlinear channel. The contribution of PERC algorithm is that it includes both pre-cursors and post-cursors as the RAM address lines, and suggests a new way to make decision on the pre-addresses. Compared with the RAM-DFE structure that only includes post- addresses, the BER versus Eb/NO performance of PERC is substantially enhanced. Experiments are performed for PERC algorithms with different parameters on AWGN channels, and the results are compared and analyzed. The investigation of this thesis includes software simulation and hardware verification. Hardware is setup to collect actual TWT data. Simulation on both the software-generated data and the real-world data are performed. Practical limitations are considered for the hardware collected data. Simulation results verified the reliability of the PERC algorithm. This work was conducted at NMSU in the Center for Space Telemetering and Telecommunications Systems in the Klipsch School of Electrical and Computer Engineering Department.

  18. Effective hydraulic resistance of a nozzle generating hybrid-synthetic jet in an electrodynamic actuator - Part II: Analysis and correlations

    Czech Academy of Sciences Publication Activity Database

    Tesař, Václav; Kordík, Jozef

    Roč. 199, September (2013), s. 391-400 ISSN 0924-4247 R&D Projects: GA TA ČR TA02020795; GA ČR(CZ) GCP101/11/J019; GA ČR GPP101/12/P556 Institutional research plan: CEZ:AV0Z20760514 Institutional support: RVO:61388998 Keywords : nozzle * periodic jet * hydraulic resistance Subject RIV: BK - Fluid Dynamics Impact factor: 1.943, year: 2013 http://dx.doi.org/10.1016/j.sna.2013.01.003

  19. Effects of the hydraulic conductivity of the matrix/macropore interface on cumulative infiltrations into dual-permeability media

    Science.gov (United States)

    Lassabatere, L.; Peyrard, X.; Angulo-Jaramillo, R.; Simunek, J.

    2009-12-01

    Modeling of water infiltration into the vadose zone is important for better understanding of movement of water-transported contaminants. There is a great need to take into account the soil heterogeneity and, in particular, the presence of macropores or cracks that could generate preferential flow. Several mathematical models have been proposed to describe unsaturated flow through heterogeneous soils. The dual-permeability model (referred to as the 2K model) assumes that flow is governed by Richards equation in both porous regions (matrix and macropores). Water can be exchanged between the two regions following a first-order rate law. Although several studies have dealt with such modeling, no study has evaluated the influence of the hydraulic conductivity of the matrix/macropore interface on water cumulative infiltration. And this is the focus of this study. An analytical scaling method reveals the role of the following main parameters for given boundary and initial conditions: the saturated hydraulic conductivity ratio (R_Ks), the water pressure scale parameter ratio (R_hg), the saturated volumetric water content ratio (R_θs), and the shape parameters of the water retention and hydraulic conductivity functions. The last essential parameter is related to the interfacial hydraulic conductivity (Ka) between the macropore and matrix regions. The scaled 2K flow equations were solved using HYDRUS-1D 4.09 for the specific case of water infiltrating into an initially uniform soil profile and a zero pressure head at the soil surface. A sensitivity of water infiltration was studied for different sets of scale parameters (R_Ks, R_hg, R_θs, and shape parameters) and the scaled interfacial conductivity (Ka). Numerical results illustrate two extreme behaviors. When the interfacial conductivity is zero (i.e., no water exchange), water infiltrates separately into matrix and macropore regions, producing a much deeper moisture front in the macropore domain. In the opposite case

  20. Evaluation of Recent Technologies of Nonvolatile RAM

    Science.gov (United States)

    Nuns, Thierry; Duzellier, Sophie; Bertrand, Jean; Hubert, Guillaume; Pouget, Vincent; Darracq, FrÉdÉric; David, Jean-Pierre; Soonckindt, Sabine

    2008-08-01

    Two types of recent nonvolatile random access memories (NVRAM) were evaluated for radiation effects: total dose and single event upset and latch-up under heavy ions and protons. Complementary irradiation with a laser beam provides information on sensitive areas of the devices.

  1. Hydric characterisation of rammed earth samples for different lime concentrations

    Science.gov (United States)

    Soudani, Lucile; Fabbri, Antonin; Woloszyn, Monika; Grillet, Anne-Cécile; Morel, Jean-Claude

    2018-04-01

    The rehabilitation of ancient rammed earth houses, as well as the use of earthen materials in modern constructions, are a growing matter of concern, especially in area such as Rhône-Alpes, France, where 40% of old constructions are in rammed earth. A current pathology observed for this type of construction is related to the rising damps, for which the water from the ground is absorbed by the wall. This situation leads to a very saturated state. As it has been proven that the compressive strength is altered by the presence of water in the pores, a better understanding on high relative humidity range is necessary to be able to predict the mechanical behavior of buildings and thus ensure a better risk assessment. The present study describes experimental results of the water uptake experiments and moisture storage at high relative humidities.

  2. Testicular Damage following Testicular Sperm Retrieval: A Ram Model Study

    Directory of Open Access Journals (Sweden)

    Jens Fedder

    2017-01-01

    Full Text Available The aim of this study was to evaluate the possible development of histological abnormalities such as fibrosis and microcalcifications after sperm retrieval in a ram model. Fourteen testicles in nine rams were exposed to open biopsy, multiple TESAs, or TESE, and the remaining four testicles were left unoperated on as controls. Three months after sperm retrieval, the testicles were removed, fixed, and cut into 1/2 cm thick slices and systematically put onto a glass plate exposing macroscopic abnormalities. Tissue from abnormal areas was cut into 3 μm sections and stained for histological evaluation. Pathological abnormalities were observed in testicles exposed to sperm retrieval (≥11 of 14 compared to 0 of 4 control testicles. Testicular damage was found independently of the kind of intervention used. Therefore, cryopreservation of excess sperm should be considered while retrieving sperm.

  3. RAtional Mapping (RAM) of in-core data

    International Nuclear Information System (INIS)

    Bonalumi, R.A.; Kherani, N.P.

    1983-01-01

    The paper describes and demonstrates a unique processing of in-core flux detector data, such that the detailed in-core power distribution can be derived with great accuracy by combining a specially 'smoothed-out' set of in-core data with neutron diffusion theory. RAM is designed in such a way that erratic detector signals are recognized very efficiently and can be eliminated from the experimental data set: this is achieved by modal expansion of the difference between theoretical fluxes and experimental fluxes at the detector sites. Sensitivity studies have shown that RAM is quite stable, does not absorb the 'wild' detector errors in the mapping procedure and results in mapped fluxes with errors about three times smaller than would be obtained by direct interpolation of detector readings

  4. Consideraciones sobre Infortunios de Alonso Ramírez

    Directory of Open Access Journals (Sweden)

    Leonor Taiano

    2010-12-01

    Full Text Available This article attempts to provide new perspectives for approaching the study of Infortunios de Alonso Ramírez. Several researches about the text have given to Sigüenza y Góngora a character of strangeness to it, which would reduce him to the role of mere amanuensis, indicating that the discursive elaboration belongs to Ramirez. In view of that, I have performed a textual analysis, supported on the book's title and the final passage of the account, that I consider important elements that can offer a new perception on this issue. I base my research, additionally, on the study of its context of publication under the patronage of the New Spain viceroy, as well as the similarities of Infortunios de Alonso Ramírez with other contemporary texts.

  5. A 1K shadow RAM for circumvention applications

    International Nuclear Information System (INIS)

    Murray, J.R.

    1991-01-01

    This paper reports that circumvention applications require a memory that retains data through radiation (total dose and transient) and loss of power. Various memory technologies have been reviewed and none, as yet, can meet, these requirements. However, if complementary metal oxide silicon (CMOS) and silicon nitride oxide silicon (SNOS) memories are combined in a shadow RAM (random access memory) configuration, the requirements can be fulfilled

  6. Automatic track counting with an optic RAM-based instrument

    International Nuclear Information System (INIS)

    Staderini, E.M.; Castellano, Alfredo

    1986-01-01

    A new image sensor, the optic RAM, is now used in a microprocessor controlled instrument to read and digitize images from CR39 solid state nuclear track detectors. The system performs image analysis, filtering, tracks counting and evaluation in a fully automatic way, not requiring an optic microscope, nor photographic or television devices. The proposed system is a very compact and low power device. (author)

  7. Beneficial effects on water management of simple hydraulic structures in wetland systems: the Vallevecchia case study, Italy.

    Science.gov (United States)

    Carrer, G M; Bonato, M; Smania, D; Barausse, A; Comis, C; Palmeri, L

    2011-01-01

    Conflicting water uses in coastal zones demand integrated approaches to achieve sustainable water resources management, protecting water quality while allowing those human activities which rely upon aquatic ecosystem services to thrive. This case study shows that the creation and simple management of hydraulic structures within constructed wetlands can markedly reduce the non-point pollution from agriculture and, simultaneously, benefit agricultural activities, particularly during hot and dry periods. The Vallevecchia wetland system is based on a reclaimed 900 ha-large drainage basin in Northern Italy, where droughts recently impacted agriculture causing water scarcity and saltwater intrusion. Rainwater and drained water are recirculated inside the system to limit saltwater intrusion, provide irrigation water during dry periods and reduce the agricultural nutrient loads discharged into the bordering, eutrophic Adriatic Sea. Monitoring (2003-2009) of water quality and flows highlights that the construction (ended in 2005) of a gated spillway to control the outflow, and of a 200,000 m3 basin for water storage, dramatically increased the removal of nutrients within the system. Strikingly, this improvement was achieved with a minimal management effort, e.g., each year the storage basin was filled once: a simple management of the hydraulic structures would greatly enhance the system efficiency, and store more water to irrigate and limit saltwater intrusion.

  8. Hydraulic Yaw System

    DEFF Research Database (Denmark)

    Stubkier, Søren; Pedersen, Henrik C.; Mørkholt, M.

    a hydraulic soft yaw system, which is able to reduce the loads on the wind turbine significantly. A full scale hydraulic yaw test rig is available for experiments and tests. The test rig is presented as well as the system schematics of the hydraulic yaw system....... the HAWC2 aeroelastic code and an extended model of the NREL 5MW turbine combined with a simplified linear model of the turbine, the parameters of the soft yaw system are optimized to reduce loading in critical components. Results shows that a significant reduction in fatigue and extreme loads to the yaw...... system and rotor shaft when utilizing the soft yaw drive concept compared to the original stiff yaw system. The physical demands of the hydraulic yaw system are furthermore examined for a life time of 20 years. Based on the extrapolated loads, the duty cycles show that it is possible to construct...

  9. Water Hydraulic Systems

    DEFF Research Database (Denmark)

    Conrad, Finn

    2005-01-01

    The paper presents research results using IT-Tools for CAD and dynamic modelling, simulation, analysis, and design of water hydraulic actuators for motion control of machines, lifts, cranes and robots. Matlab/Simulink and CATIA are used as IT-Tools. The contributions include results from on......-going research projects on fluid power and mechatronics based on tap water hydraulic servovalves and linear servo actuators and rotary vane actuators for motion control and power transmission. Development and design a novel water hydraulic rotary vane actuator for robot manipulators. Proposed mathematical...... modelling, control and simulation of a water hydraulic rotary vane actuator applied to power and control a two-links manipulator and evaluate performance. The results include engineering design and test of the proposed simulation models compared with IHA Tampere University’s presentation of research...

  10. Hydraulic hoisting and backfilling

    Science.gov (United States)

    Sauermann, H. B.

    In a country such as South Africa, with its large deep level mining industry, improvements in mining and hoisting techniques could result in substantial savings. Hoisting techniques, for example, may be improved by the introduction of hydraulic hoisting. The following are some of the advantages of hydraulic hoisting as against conventional skip hoisting: (1) smaller shafts are required because the pipes to hoist the same quantity of ore hydraulically require less space in the shaft than does skip hoisting equipment; (2) the hoisting capacity of a mine can easily be increased without the necessity of sinking new shafts. Large savings in capital costs can thus be made; (3) fully automatic control is possible with hydraulic hoisting and therefore less manpower is required; and (4) health and safety conditions will be improved.

  11. Investigating EMIC Wave Dynamics with RAM-SCB-E

    Science.gov (United States)

    Jordanova, V. K.; Fu, X.; Henderson, M. G.; Morley, S.; Welling, D. T.; Yu, Y.

    2017-12-01

    The distribution of ring current ions and electrons in the inner magnetosphere depends strongly on their transport in realistic electric (E) and magnetic (B) fields and concurrent energization or loss. To investigate the high variability of energetic particle (H+, He+, O+, and electron) fluxes during storms selected by the GEM Surface Charging Challenge, we use our kinetic ring current model (RAM) two-way coupled with a 3-D magnetic field code (SCB). This model was just extended to include electric field calculations, making it a unique, fully self-consistent, anisotropic ring current-atmosphere interactions model, RAM-SCB-E. Recently we investigated electromagnetic ion cyclotron (EMIC) instability in a local plasma using both linear theory and nonlinear hybrid simulations and derived a scaling formula that relates the saturation EMIC wave amplitude to initial plasma conditions. Global dynamic EMIC wave maps obtained with our RAM-SCB-E model using this scaling will be presented and compared with statistical models. These plasma waves can affect significantly both ion and electron precipitation into the atmosphere and the subsequent patterns of ionospheric conductance, as well as the global ring current dynamics.

  12. Ram-pressure feeding of supermassive black holes.

    Science.gov (United States)

    Poggianti, Bianca M; Jaffé, Yara L; Moretti, Alessia; Gullieuszik, Marco; Radovich, Mario; Tonnesen, Stephanie; Fritz, Jacopo; Bettoni, Daniela; Vulcani, Benedetta; Fasano, Giovanni; Bellhouse, Callum; Hau, George; Omizzolo, Alessandro

    2017-08-16

    When a supermassive black hole at the centre of a galaxy accretes matter, it gives rise to a highly energetic phenomenon: an active galactic nucleus. Numerous physical processes have been proposed to account for the funnelling of gas towards the galactic centre to feed the black hole. There are also several physical processes that can remove gas from a galaxy, one of which is ram-pressure stripping by the hot gas that fills the space between galaxies in galaxy clusters. Here we report that six out of a sample of seven 'jellyfish' galaxies-galaxies with long 'tentacles' of material that extend for dozens of kiloparsecs beyond the galactic disks-host an active nucleus, and two of them also have galactic-scale ionization cones. The high incidence of nuclear activity among heavily stripped jellyfish galaxies may be due to ram pressure causing gas to flow towards the centre and triggering the activity, or to an enhancement of the stripping caused by energy injection from the active nucleus, or both. Our analysis of the galactic position and velocity relative to the cluster strongly supports the first hypothesis, and puts forward ram pressure as another possible mechanism for feeding the central supermassive black hole with gas.

  13. Investigation of 3D spatial effect on point kinetics estimation of the thermal hydraulics code RELAP for the analysis of MSLB accident of KK-NP

    International Nuclear Information System (INIS)

    Bera, S.; Pradhan, S.K.; Dubey, S.K.; Gupta, S.K.

    2011-01-01

    In general safety analyses of design basis accident of NPPs are being carried out using system thermal hydraulics code like RELAP. In RELAP, power is calculated based on point kinetics approximation, which virtually ignores the space and energy dependence of neutron flux. To include the space and energy dependence of neutron flux, three-dimensional neutronics code TRIHEXFA has been externally coupled with RELAP through interface program, TRIHEXFA-RELAP Interface Program (TRIP). Calculation methodology of TRIP program is based on adiabatic approximation. In the adiabatic approximation the neutron flux is being factored into spatial and amplitude part. Spatial part of flux is slowly varying with time whereas amplitude part is strongly varying function. The RELAP controls the transient time steps. Transient time is divided into several major and minor time steps. Minor time step is the sub-step of major time step. Thermal hydraulics and neutronics data are exchanged at each major time step. Spatial part of neutron flux has been updated at each major time step using TRIHEXFA code. But amplitude part of the neutron flux is calculated at each minor time step using RELAP code. Convergence of results of the coupled code, TRIP has been checked through coupling time step descritization study. This study determines the minimum coupling time step. Transient concerning VVER-1000 Main Steam Line Break, MSLB has been considered to investigate the space-time effect on point kinetics. MSLB occurs as a consequence of the rupture of one steam line upstream of main steam line isolation valves. Reference design and data from Kudankulam Nuclear Power Plant (KK-NPP) are used for the analysis. From this investigation it is found that TRIP significantly overestimates the maximum reactor power against uncoupled RELAP result. The time of scram also occur six seconds earlier in TRIP calculation compared to the RELAP. This exercise has also shown a proof of principle that coupling 3D

  14. RAM analysis of earth pressure balance tunnel boring machines: A case study

    Directory of Open Access Journals (Sweden)

    Hasel Amini Khoshalan

    2015-12-01

    Full Text Available Earth pressure balance tunnel boring machines (EPB-TBMs are favorably applied in urban tunneling projects. Despite their numerous advantages, considerable delays and high maintenance cost are the main disadvantages these machines suffer from. Reliability, availability, and maintainability (RAM analysis is a practical technique that uses failure and repair dataset obtained over a reasonable time for dealing with proper machine operation, maintenance scheduling, cost control, and improving the availability and performance of such machines. In the present study, a database of failures and repairs of an EBP-TBM was collected in line 1 of Tabriz subway project over a 26-month interval of machine operation. In order to model the reliability of the TBM, this machine was divided into five distinct subsystems including mechanical, electrical, hydraulic, pneumatic, and water systems in a series configuration. According to trend and serial correlation tests, the renewal processes were applied, for analysis of all subsystems. After calculating the reliability and maintainability functions for all subsystems, it was revealed that the mechanical subsystem with the highest failure frequency has the lowest reliability and maintainability. Similarly, estimating the availability of all subsystems indicated that the mechanical subsystem has a relatively low availability level of 52.6%, while other subsystems have acceptable availability level of 97%. Finally, the overall availability of studied machine was calculated as 48.3%.

  15. The hydraulic wheel

    International Nuclear Information System (INIS)

    Alvarez Cardona, A.

    1985-01-01

    The present article this dedicated to recover a technology that key in disuse for the appearance of other techniques. It is the hydraulic wheel with their multiple possibilities to use their energy mechanical rotational in direct form or to generate electricity directly in the fields in the place and to avoid the high cost of transport and transformation. The basic theory is described that consists in: the power of the currents of water and the hydraulic receivers. The power of the currents is determined knowing the flow and east knowing the section of the flow and its speed; they are given you formulate to know these and direct mensuration methods by means of floodgates, drains and jumps of water. The hydraulic receivers or properly this hydraulic wheels that are the machines in those that the water acts like main force and they are designed to transmit the biggest proportion possible of absolute work of the water, the hydraulic wheels of horizontal axis are the common and they are divided in: you rotate with water for under, you rotate with side water and wheels with water for above. It is analyzed each one of them, their components are described; the conditions that should complete to produce a certain power and formulate them to calculate it. There are 25 descriptive figures of the different hydraulic wheels

  16. The TN-RAM - a new cask for shipping high activity irradiated hardware

    International Nuclear Information System (INIS)

    Neider, T.; Hanson, A.S.

    1993-01-01

    Transnuclear, Inc. has developed a Type B(U) radioactive material transport packaging designed specifically for the transport of dry, irradiated, non-fuel bearing components (NFBC). The TN-RAM is a transport cask in the configuration of a right circular cylinder, fabricated from lead and stainless steel, with wood-filled impact limiters attached at both ends. The lead and stainless steel construction of the lid, walls, and bottom provides a shielding effectiveness of approximately 7.1 inches (18 cm) lead equivalent. (J.P.N.)

  17. Experimental investigation of the flow near the ram element in the brush turbine

    Directory of Open Access Journals (Sweden)

    Schmirler M.

    2015-01-01

    Full Text Available The paper focuses on the investigating of the parameters of the fluid flow around the brush turbine ram element. The flow field was evaluated qualitatively by observing changes in density using a Schlieren method. It was also evaluated the influence of the element geometry on the total aerodynamic force of the element. The aerodynamic force was measured directly using a special aerodynamic balance. The aim of the project was to find the simplest element geometry with a maximum force effect and achieve an increase in overall efficiency and reduce the manufacturing costs.

  18. Test CMOS/SOS RAM for transient radiation upset comparative research and failure analysis

    International Nuclear Information System (INIS)

    Nikiforov, A.Y.; Poljakov, I.V.

    1995-01-01

    The test Complementary Metal-Oxide-Semiconductor/Silicon-on-Sapphire Random Access Memory (CMOS/SOS RAM) with eight types of memory cells was designed and tested at high dose rates with a flash X-ray machine and laser simulator. The memory cell (MC) design with additional transistors and RC-chain was found to be upset free up to 2 x 10 12 rad(Si)/s. An inversion effect was discovered in which almost 100% logic upset was observed in poorly protected memory cell arrays at very high dose rates

  19. Hydraulic continuity and biological effects of low strength very low frequency electromagnetic waves: Case of microbial biofilm growth in water treatment.

    Science.gov (United States)

    Gérard, Merlin; Noamen, Omri; Evelyne, Gonze; Eric, Valette; Gilles, Cauffet; Marc, Henry

    2015-10-15

    This study aims to elucidate the interactions between water, subjected to electromagnetic waves of very low frequency (VLF) (kHz) with low strength electromagnetic fields (3.5 mT inside the coils), and the development of microbial biofilms in this exposed water. Experimental results demonstrate that in water exposed to VLF electromagnetic waves, the biomass of biofilm is limited if hydraulic continuity is achieved between the electromagnetic generator and the biofilm media. The measured amount of the biofilm's biomass is approximately a factor two lower for exposed biofilm than the non-exposed biofilm. Measurements of electromagnetic fields in the air and simulations exhibit very low intensities of fields (electromagnetic generator. Exposure to electric and magnetic fields of the quoted intensities cannot explain thermal and ionizing effects on the biofilm. A variable electrical potential with a magnitude close to 20 mV was detected in the tank in hydraulic continuity with the electromagnetic generator. The application of quantum field theory may help to explain the observed effects in this case. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. Data Analytics of Hydraulic Fracturing Data

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Jovan Yang [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Viswanathan, Hari [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Hyman, Jeffery [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Middleton, Richard [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-08-11

    These are a set of slides on the data analytics of hydraulic fracturing data. The conclusions from this research are the following: they proposed a permeability evolution as a new mechanism to explain hydraulic fracturing trends; they created a model to include this mechanism and it showed promising results; the paper from this research is ready for submission; they devised a way to identify and sort refractures in order to study their effects, and this paper is currently being written.

  1. Photo-fermentative hydrogen production in a 4m3 baffled reactor: Effects of hydraulic retention time.

    Science.gov (United States)

    Zhang, Quanguo; Lu, Chaoyang; Lee, Duu-Jong; Lee, Yu-Jen; Zhang, Zhiping; Zhou, Xuehua; Hu, Jianjun; Wang, Yi; Jiang, Danping; He, Chao; Zhang, Tian

    2017-09-01

    A 4m 3 pilot-scale baffled continuous-flow photoreactor with four sequential chambers (#1-#4) was established and tested to evaluate its photo-fermentative hydrogen production from wastewater that contains (10g/L glucose using a functional consortium at 30°C, under light with an intensity of 3000±200lux with a hydraulic retention time (HRT) of 24-72h. The hydrogen production rate and the broth characteristics varied significantly in the flow direction. The hydrogen production rate was highest in chamber #1, and lower in chambers #2-#4 at an HRT of 72h, while the peak production rate shifted to the latter chambers as the HRT was shortened. The overall H 2 production rate increased as HRT decreased, but was not consistent with the predictions that were based on the complete-mixing assumption. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Anaerobic co-digestion of swine manure and crude glycerol derived from animal fat - Effect of hydraulic retention time

    DEFF Research Database (Denmark)

    Lymperatou, Anna; Skiadas, Ioannis V.; Gavala, Hariklia N.

    2018-01-01

    Crude glycerol (CG), an abundant by-product of bio-diesel production, has been identified as a suitable co-substrate for improving the biogas production of livestock manure through anaerobic digestion (AD). In this study, the potential of utilizing CG generated from the esterification of animal......, biochemical methane potential tests indicated that the addition of 1% w/w CG to swine manure-AD is more efficient in terms of percent of theoretical amount of methane obtained than the addition of 3% w/w. However, in continuous experiments, co-digestion of manure with 3% w/w CG did not exhibit any sign...... fats for biogas production was studied in both batch and continuous AD experiments, with emphasis on the importance of the hydraulic retention time (HRT). Batch experiments showed that the limiting step in the methane production rate during CG mono-digestion was the 1,3-propanediol uptake. Additionally...

  3. Enhancement of anaerobic acidogenesis by integrating an electrochemical system into an acidogenic reactor: effect of hydraulic retention times (HRT) and role of bacteria and acidophilic methanogenic Archaea.

    Science.gov (United States)

    Zhang, Jingxin; Zhang, Yaobin; Quan, Xie; Chen, Shuo

    2015-03-01

    In this study, an acidogenic reactor packed with a pair of Fe-carbon electrodes (R1) was developed to enhance anaerobic acidogenesis of organic wastewater at short hydraulic retention times. The results indicated that the acidogenic efficiency was improved by settling a bio-electrochemical system. When hydraulic retention times decreased from 12 to 3h, R1 showed 18.9% more chemical oxygen demand removal and 13.8% more acidification efficiency. After cutting off the voltage of R1, the COD removal decreased by about 5%. Coupling of Fe(2+) leaching and electric field accelerated the hydrolysis of polysaccharide, relieving its accumulation in the sludge phase. Several acidophilic methanogenic Archaea such as Methanosarcina sp. were enriched in R1, which was favorable for consuming organic acids and preventing excessive pH decline. Thus, the developed acidogenic reactor with Fe-carbon electrodes is expected to be potentially effective and useful for wastewater treatment. Copyright © 2014 Elsevier Ltd. All rights reserved.

  4. THE ROLE OF RAM PRESSURE STRIPPING IN THE QUENCHING OF CLUSTER STAR FORMATION

    International Nuclear Information System (INIS)

    Book, Laura G.; Benson, Andrew J.

    2010-01-01

    Recent observations of galaxy clusters have shown that environmental effects apparently associated with the cluster begin to lower the star formation rates of galaxies at distances as great as three times the cluster virial radius. These observations may indicate preprocessing of cluster galaxies in groups or in the cluster core for galaxies on highly elliptical orbits, but may also imply that the environmental effects due to the cluster are directly affecting galaxies on their first infall. To explore these issues, we investigate different models of ram pressure stripping (RPS) as it acts on satellite galaxies in clusters and compare to observations of the radial star formation gradient in clusters. We calculate the location of the accretion shock around model clusters and use this as the radius of onset of RPS in the GALFORM semi-analytic model of galaxy formation. Comparison of the results of our model and previously considered, simpler ram pressure models with recent observations indicates that current data are unable to strongly discriminate between models of RPS due to the complex interplay of preprocessing effects at work. However, future observations of a larger sample of clusters will likely be able to place stronger constraints on the process of RPS and its role in shaping radial trends in and around clusters.

  5. Computing in Hydraulic Engineering Education

    Science.gov (United States)

    Duan, J. G.

    2011-12-01

    Civil engineers, pioneers of our civilization, are rarely perceived as leaders and innovators in modern society because of retardations in technology innovation. This crisis has resulted in the decline of the prestige of civil engineering profession, reduction of federal funding on deteriorating infrastructures, and problems with attracting the most talented high-school students. Infusion of cutting-edge computer technology and stimulating creativity and innovation therefore are the critical challenge to civil engineering education. To better prepare our graduates to innovate, this paper discussed the adaption of problem-based collaborative learning technique and integration of civil engineering computing into a traditional civil engineering curriculum. Three interconnected courses: Open Channel Flow, Computational Hydraulics, and Sedimentation Engineering, were developed with emphasis on computational simulations. In Open Channel flow, the focuses are principles of free surface flow and the application of computational models. This prepares students to the 2nd course, Computational Hydraulics, that introduce the fundamental principles of computational hydraulics, including finite difference and finite element methods. This course complements the Open Channel Flow class to provide students with in-depth understandings of computational methods. The 3rd course, Sedimentation Engineering, covers the fundamentals of sediment transport and river engineering, so students can apply the knowledge and programming skills gained from previous courses to develop computational models for simulating sediment transport. These courses effectively equipped students with important skills and knowledge to complete thesis and dissertation research.

  6. Serum testosterone level and affecting factors in Syrian Awassi ram lambs

    International Nuclear Information System (INIS)

    Zarkawi, M.

    2004-01-01

    Results showed that testosterone exists in the blood of ram lams as early as the first month of age with no significant difference between single and twin births. This level, however, increased gradually with advancing age of ram lambs, indicating that the gonads (testes) of these growing lambs were active in secreting testosterone hormone after birth, but the rate of secretion differed with age of the lambs. A sharp increase in testosterone level was recorded at age of 8 months in twin births (5.32 ± 20.99 nmol/l) and in single births (7.26 ± 3.29 nmol/l). Throughout the study period, mean testosterone serum level was 3.29 ± 2.73 and 2.54 ± 2.15 nmol/l for single and twin births, respectively, as compared with an overall mean of 3.00 ± 2.49 nmol/l. However, the monthly difference in testosterone level between single and twin births was not significant (P>0.05) throughout the study period (10 months). Results also indicated an increase in live weight of lambs with advancing age, and live weight in single births was higher, but not significantly, than in twin births throughout the study period. Results of the study showed a sharp increase in the mean live weight of single births at age of 8 months (48.5 ± 10.8 kg) as compared with an overall live weight of the lambs (35.8 ± 15.2 and 32.7 ± 15.4 kg for single and twin births, respectively). A positive and significant correlation (r= 0.95, P>0.0001) was found between serum testosterone level and lamb live weight during the first 10 months of their age. Finally and for the first time, normal serum testosterone levels in Syrian Awassi ram lambs were determined during early stages. It was concluded, based on both, testosterone level and lamb live weight, that puberty in Awassi ram lambs could be reached at 8 months of age with a mean live weight of around 47 kg. Type of birth, lamb birth weight or weaning weight had no significant effect on testosterone level. (author)

  7. Cavitation in Hydraulic Machinery

    Energy Technology Data Exchange (ETDEWEB)

    Kjeldsen, M.

    1996-11-01

    The main purpose of this doctoral thesis on cavitation in hydraulic machinery is to change focus towards the coupling of non-stationary flow phenomena and cavitation. It is argued that, in addition to turbulence, superimposed sound pressure fluctuations can have a major impact on cavitation and lead to particularly severe erosion. For the design of hydraulic devices this finding may indicate how to further limit the cavitation problems. Chapter 1 reviews cavitation in general in the context of hydraulic machinery, emphasizing the initial cavitation event and the role of the water quality. Chapter 2 discusses the existence of pressure fluctuations for situations common in such machinery. Chapter 3 on cavitation dynamics presents an algorithm for calculating the nucleation of a cavity cluster. Chapter 4 describes the equipment used in this work. 53 refs., 55 figs.,10 tabs.

  8. Characterizing material properties of cement-stabilized rammed earth to construct sustainable insulated walls

    Directory of Open Access Journals (Sweden)

    Rishi Gupta

    2014-01-01

    Full Text Available Use of local materials can reduce the hauling of construction materials over long distances, thus reducing the greenhouse gas emissions associated with transporting such materials. Use of locally available soils (earth for construction of walls has been used in many parts of the world. Owing to the thermal mass of these walls and the potential to have insulation embedded in the wall section has brought this construction material/technology at the forefront in recent years. However, the mechanical properties of the rammed earth and the parameters required for design of steel reinforced walls are not fully understood. In this paper, the author presents a case study where full-scale walls were constructed using rammed earth to understand the effect of two different types of shear detailing on the structural performance of the walls. The mechanical properties of the material essential for design such as compressive strength of the material including effect of coring on the strength, pull out strength of different rebar diameters, flexural performance and out-of-plane bending on walls was studied. These results are presented in this case study.

  9. Waste Feed Delivery System Phase 1 Preliminary RAM Analysis

    International Nuclear Information System (INIS)

    DYKES, A.A.

    2000-01-01

    This report presents the updated results of the preliminary reliability, availability, and maintainability (RAM) analysis of selected waste feed delivery (WFD) operations to be performed by the Tank Farm Contractor (TFC) during Phase I activities in support of the Waste Treatment and Immobilization Plant (WTP). For planning purposes, waste feed tanks are being divided into five classes in accordance with the type of waste in each tank and the activities required to retrieve, qualify, and transfer waste feed. This report reflects the baseline design and operating concept, as of the beginning of Fiscal Year 2000, for the delivery of feed from three of these classes, represented by source tanks 241-AN-102, 241-AZ-101 and 241-AN-105. The preliminary RAM analysis quantifies the potential schedule delay associated with operations and maintenance (OBM) field activities needed to accomplish these operations. The RAM analysis is preliminary because the system design, process definition, and activity planning are in a state of evolution. The results are being used to support the continuing development of an O and M Concept tailored to the unique requirements of the WFD Program, which is being documented in various volumes of the Waste Feed Delivery Technical Basis (Carlson. 1999, Rasmussen 1999, and Orme 2000). The waste feed provided to the WTP must: (1) meet limits for chemical and radioactive constituents based on pre-established compositional envelopes (i.e., feed quality); (2) be in acceptable quantities within a prescribed sequence to meet feed quantities; and (3) meet schedule requirements (i.e., feed timing). In the absence of new criteria related to acceptable schedule performance due to the termination of the TWRS Privatization Contract, the original criteria from the Tank Waste Remediation System (77443s) Privatization Contract (DOE 1998) will continue to be used for this analysis

  10. Hydraulics and pneumatics

    CERN Document Server

    Parr, Andrew

    2006-01-01

    Nearly all industrial processes require objects to be moved, manipulated or subjected to some sort of force. This is frequently accomplished by means of electrical equipment (such as motors or solenoids), or via devices driven by air (pneumatics) or liquids (hydraulics).This book has been written by a process control engineer as a guide to the operation of hydraulic and pneumatic systems for all engineers and technicians who wish to have an insight into the components and operation of such a system.This second edition has been fully updated to include all recent developments su

  11. HYDRAULIC SERVO CONTROL MECHANISM

    Science.gov (United States)

    Hussey, R.B.; Gottsche, M.J. Jr.

    1963-09-17

    A hydraulic servo control mechanism of compact construction and low fluid requirements is described. The mechanism consists of a main hydraulic piston, comprising the drive output, which is connected mechanically for feedback purposes to a servo control piston. A control sleeve having control slots for the system encloses the servo piston, which acts to cover or uncover the slots as a means of controlling the operation of the system. This operation permits only a small amount of fluid to regulate the operation of the mechanism, which, as a result, is compact and relatively light. This mechanism is particuiarly adaptable to the drive and control of control rods in nuclear reactors. (auth)

  12. Hydraulic Arm Modeling via Matlab SimHydraulics

    Czech Academy of Sciences Publication Activity Database

    Věchet, Stanislav; Krejsa, Jiří

    2009-01-01

    Roč. 16, č. 4 (2009), s. 287-296 ISSN 1802-1484 Institutional research plan: CEZ:AV0Z20760514 Keywords : simulatin modeling * hydraulics * SimHydraulics Subject RIV: JD - Computer Applications, Robotics

  13. The Multi-Porosity Multi-Permeability and Electrokinetic Natures of Shales and Their Effects in Hydraulic Fracturing of Unconventional Shale Reservoirs

    Science.gov (United States)

    Liu, C.; Hoang, S. K.; Tran, M. H.; Abousleiman, Y. N.

    2013-12-01

    Imaging studies of unconventional shale reservoir rocks have recently revealed the multi-porosity multi-permeability nature of these intricate formations. In particular, the porosity spectrum of shale reservoir rocks often comprises of the nano-porosity in the organic matters, the inter-particle micro-porosity, and the macroscopic porosity of the natural fracture network. Shale is also well-known for its chemically active behaviors, especially shrinking and swelling when exposed to aqueous solutions, as the results of pore fluid exchange with external environment due to the difference in electro-chemical potentials. In this work, the effects of natural fractures and electrokinetic nature of shale on the formation responses during hydraulic fracturing are examined using the dual-poro-chemo-electro-elasticity approach which is a generalization of the classical Biot's poroelastic formulation. The analyses show that the presence of natural fractures can substantially increase the leak-off rate of fracturing fluid into the formation and create a larger region of high pore pressure near the fracture face as shown in Fig.1a. Due to the additional fluid invasion, the naturally fractured shale swells up more and the fracture aperture closes faster compared to an intrinsically low permeability non-fractured shale formation as shown in Fig.1b. Since naturally fractured zones are commonly targeted as pay zones, it is important to account for the faster fracture closing rate in fractured shales in hydraulic fracturing design. Our results also show that the presence of negative fixed charges on the surface of clay minerals creates an osmotic pressure at the interface of the shale and the external fluid as shown in Fig.1c. This additional Donnan-induced pore pressure can result in significant tensile effective stresses and tensile damage in the shale as shown in Fig.1d. The induced tensile damage can exacerbate the problem of proppant embedment resulting in more fracture closure

  14. Bioleaching of spent Ni-Cd batteries by continuous flow system: Effect of hydraulic retention time and process load

    International Nuclear Information System (INIS)

    Zhao Ling; Yang Dong; Zhu Nanwen

    2008-01-01

    Spent Ni-Cd batteries bring a severe environmental problem that needs to be solved urgently. A novel continuous flow two-step leaching system based on bioleaching was introduced to dissolve heavy metals in batteries. It consists of an acidifying reactor which was used to culture indigenous thiobacilli and a leaching reactor which was used to leach metals from spent batteries. The indigenous acidophilic thiobacilli in sewage sludge was used as the microorganisms and the sludge itself as culture medium. Bioleaching tests at different hydraulic retention time (HRT) and process load in the leaching reactor were performed. The results showed that the longer the HRT (1, 3, 6, 9 and 15 days) was, the more time required to achieve the complete leaching of Ni, Cd and Co. The maximum dissolution of cadmium and cobalt was achieved at higher pH values (3.0-4.5) while the leaching of nickel hydroxide and nickel in metallic form (Ni 0 ) were obtained separately in different acidity (pH 2.5-3.5). It cost about 25, 30 and more than 40 days to remove all of the three heavy metals with the process load of two, four and eight Ni-Cd batteries under the conditions that the ingoing bio-sulphuric acid was 1 L d -1 and HRT was 3 days

  15. Bioleaching of spent Ni-Cd batteries by continuous flow system: effect of hydraulic retention time and process load.

    Science.gov (United States)

    Zhao, Ling; Yang, Dong; Zhu, Nan-Wen

    2008-12-30

    Spent Ni-Cd batteries bring a severe environmental problem that needs to be solved urgently. A novel continuous flow two-step leaching system based on bioleaching was introduced to dissolve heavy metals in batteries. It consists of an acidifying reactor which was used to culture indigenous thiobacilli and a leaching reactor which was used to leach metals from spent batteries. The indigenous acidophilic thiobacilli in sewage sludge was used as the microorganisms and the sludge itself as culture medium. Bioleaching tests at different hydraulic retention time (HRT) and process load in the leaching reactor were performed. The results showed that the longer the HRT (1, 3, 6, 9 and 15 days) was, the more time required to achieve the complete leaching of Ni, Cd and Co. The maximum dissolution of cadmium and cobalt was achieved at higher pH values (3.0-4.5) while the leaching of nickel hydroxide and nickel in metallic form (Ni0) were obtained separately in different acidity (pH 2.5-3.5). It cost about 25, 30 and more than 40 days to remove all of the three heavy metals with the process load of two, four and eight Ni-Cd batteries under the conditions that the ingoing bio-sulphuric acid was 1Ld(-1) and HRT was 3 days.

  16. Bioleaching of spent Ni-Cd batteries by continuous flow system: Effect of hydraulic retention time and process load

    Energy Technology Data Exchange (ETDEWEB)

    Zhao Ling; Yang Dong [School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240 (China); Zhu Nanwen [School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240 (China)], E-mail: nwzhu@sina.com

    2008-12-30

    Spent Ni-Cd batteries bring a severe environmental problem that needs to be solved urgently. A novel continuous flow two-step leaching system based on bioleaching was introduced to dissolve heavy metals in batteries. It consists of an acidifying reactor which was used to culture indigenous thiobacilli and a leaching reactor which was used to leach metals from spent batteries. The indigenous acidophilic thiobacilli in sewage sludge was used as the microorganisms and the sludge itself as culture medium. Bioleaching tests at different hydraulic retention time (HRT) and process load in the leaching reactor were performed. The results showed that the longer the HRT (1, 3, 6, 9 and 15 days) was, the more time required to achieve the complete leaching of Ni, Cd and Co. The maximum dissolution of cadmium and cobalt was achieved at higher pH values (3.0-4.5) while the leaching of nickel hydroxide and nickel in metallic form (Ni{sup 0}) were obtained separately in different acidity (pH 2.5-3.5). It cost about 25, 30 and more than 40 days to remove all of the three heavy metals with the process load of two, four and eight Ni-Cd batteries under the conditions that the ingoing bio-sulphuric acid was 1 L d{sup -1} and HRT was 3 days.

  17. Mine drivage in hydraulic mines

    Energy Technology Data Exchange (ETDEWEB)

    Ehkber, B Ya

    1983-09-01

    From 20 to 25% of labor cost in hydraulic coal mines falls on mine drivage. Range of mine drivage is high due to the large number of shortwalls mined by hydraulic monitors. Reducing mining cost in hydraulic mines depends on lowering drivage cost by use of new drivage systems or by increasing efficiency of drivage systems used at present. The following drivage methods used in hydraulic mines are compared: heading machines with hydraulic haulage of cut rocks and coal, hydraulic monitors with hydraulic haulage, drilling and blasting with hydraulic haulage of blasted rocks. Mining and geologic conditions which influence selection of the optimum mine drivage system are analyzed. Standardized cross sections of mine roadways driven by the 3 methods are shown in schemes. Support systems used in mine roadways are compared: timber supports, roof bolts, roof bolts with steel elements, and roadways driven in rocks without a support system. Heading machines (K-56MG, GPKG, 4PU, PK-3M) and hydraulic monitors (GMDTs-3M, 12GD-2) used for mine drivage are described. Data on mine drivage in hydraulic coal mines in the Kuzbass are discussed. From 40 to 46% of roadways are driven by heading machines with hydraulic haulage and from 12 to 15% by hydraulic monitors with hydraulic haulage.

  18. The RAM +L analysis methodology: the refinery plants case study; Analise RAM +L: um estudo integrado de varias unidades de producao de uma refinaria

    Energy Technology Data Exchange (ETDEWEB)

    Calixto, Eduardo [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil). Centro de Pesquisas (CENPES); Bretas, Rogerio [PETROBRAS S.A., Betim, MG (Brazil). Refinaria Gabriel Passos (REGAP)

    2008-07-01

    The RAM (Reliability, Availability and Maintainability) main objective is assess the system and equipment performance in order to identify the critical issues to implement system's improvements. The first step is define equipment failure modes and it's PDF as well as repair time for each failure mode. The second step is modeling system regarding diagram block logic dependency among equipment and its failures which cause system production losses. The third step is simulating model in defined period of time in order to identify critical equipment to propose system improvement. Despite being having been used constantly to assess system performances, those methodology do not consider the logistic complex assumptions in so many cases to huge systems and it RDB logic do not represent the real effect in production losses. Even if that good enough to perform system analysis it's not quite enough to complex system with logistic resources regarding system's products efficiency. By the other way round, in logistic complex system analysis methodologies, equipment failures details are not regarded in so many times, showing that there's a necessary improvement in those analysis. Therefore, the RAM + L analysis is a methodology which regards all equipment failures issues as well as logistic assumptions being a more realistic analysis. The refinery case study Will be propose to demonstrate a new vision of two recognized methodologies regarding a complex system with over than 200 equipment comprising two tanks, two pumps and five Unit Plants as Vacuum Distillation, Atmospheric Distillation, Hydrogen Generation, Diesel Hydrotreating Unit and DEA. (author)

  19. RAM investigation of coal-fired thermal power plants: A case study

    Directory of Open Access Journals (Sweden)

    D. Bose

    2012-04-01

    Full Text Available Continuous generation of electricity of a power plant depends on the higher availability of its components/equipments. Higher availability of the components/equipments is inherently associated with their higher reliability and maintainability. This paper investigates the reliability, availability and maintainability (RAM characteristics of a 210 MW coal-fired thermal power plant (Unit-2 from a thermal power station in eastern region of India. Critical mechanical subsystems with respect to failure frequency, reliability and maintainability are identified for taking necessary measures for enhancing availability of the power plant and the results are compared with Unit-1 of the same Power Station. Reliability-based preventive maintenance intervals (PMIs at various reliability levels of the subsystems are estimated also for performing their preventive maintenance (PM. The present paper highlights that in the Unit-2, Economizer (ECO & Furnace Wall Tube (FWT exhibits lower reliability as compared to the other subsystems and Economizer (ECO & Baffle Wall Tube (BWT demands more improvement in maintainability. Further, it has been observed that FSH followed Decreasing Failure Rate (DFR and Economizer (ECO is the most critical subsystem for both the plants. RAM analysis is very much effective in finding critical subsystems and deciding their preventive maintenance program for improving availability of the power plant as well as the power supply.

  20. Alpha-particle-induced soft errors in high speed bipolar RAM

    International Nuclear Information System (INIS)

    Mitsusada, Kazumichi; Kato, Yukio; Yamaguchi, Kunihiko; Inadachi, Masaaki

    1980-01-01

    As bipolar RAM (Random Access Memory) has been improved to a fast acting and highly integrated device, the problems negligible in the past have become the ones that can not be ignored. The problem of a-particles emitted from the radioactive substances in semiconductor package materials should be specifically noticed, which cause soft errors. The authors have produced experimentally the special 1 kbit bipolar RAM to investigate its soft errors. The package used was the standard 16 pin dual in-line type, with which the practical system mounting test and a-particle irradiation test have been performed. The results showed the occurrence of soft errors at the average rate of about 1 bit/700 device hour. It is concluded that the cause was due to the a-particles emitted from the package materials, and at the same time, it was found that the rate of soft error occurrence was able to be greatly reduced by shielding a-particles. The error rate significantly increased with the decrease of the stand-by current of memory cells and with the accumulated charge determined by time constant. The mechanism of soft error was also investigated, for which an approximate model to estimate the error rate by means of the effective noise charge due to a-particles and of the amount of reversible charges of memory cells is shown to compare it with the experimental results. (Wakatsuki, Y.)

  1. Observing RAM Pressure Stripping and Morphological Transformation in the Coma Cluster

    Science.gov (United States)

    Gregg, Michael; West, Michael

    2017-07-01

    The two largest spirals in the Coma cluster, NGC4911 and NGC4921, are being vigorously ram-pressure stripped by the hot intracluster medium. Our HST ACS and WFC3 images have revealed galactic scale shock fronts, giant "Pillars of Creation", rivulets of dust, and spatially coherent star formation in these grand design spirals. We have now obtained HST WFC3 imaging of five additional large Coma spirals to search for and investigate the effects of ram pressure stripping across the wider cluster environment. The results are equally spectacular as the first two examples. The geometry of the interactions in some cases allows an estimation of the various time scales involved, including gas flows out of the disk leading to creation of the ICM, and the attendant triggered star formation in the galaxy disks. The global star formation patterns yield insights into the spatial and temporal ISM-ICM interactions driving cluster galaxy evolution and ultimately transforming morphologies from spiral to S0. These processes were much more common in the early Universe when the intergalactic and intracluster components were initially created from stripping and destruction of member galaxies.

  2. Hydraulic shock absorbers

    International Nuclear Information System (INIS)

    Thatcher, G.; Davidson, D. F.

    1984-01-01

    A hydraulic shock absorber of the dash pot kind for use with electrically conducting liquid such as sodium, has magnet means for electro magnetically braking a stream of liquid discharged from the cylinder. The shock absorber finds use in a liquid metal cooled nuclear reactor for arresting control rods

  3. Preparation of hydraulic cement

    Energy Technology Data Exchange (ETDEWEB)

    1921-08-28

    A process for the preparation of hydraulic cement by the use of oil-shale residues is characterized in that the oil-shale refuse is mixed with granular basic blast-furnace slag and a small amount of portland cement and ground together.

  4. Small hydraulic turbine drives

    Science.gov (United States)

    Rostafinski, W. A.

    1970-01-01

    Turbine, driven by the fluid being pumped, requires no external controls, is completely integrated into the flow system, and has bearings which utilize the main fluid for lubrication and cooling. Torque capabilities compare favorably with those developed by positive displacement hydraulic motors.

  5. Modelling of Hydraulic Robot

    DEFF Research Database (Denmark)

    Madsen, Henrik; Zhou, Jianjun; Hansen, Lars Henrik

    1997-01-01

    This paper describes a case study of identifying the physical model (or the grey box model) of a hydraulic test robot. The obtained model is intended to provide a basis for model-based control of the robot. The physical model is formulated in continuous time and is derived by application...

  6. Manual Hydraulic Structures

    NARCIS (Netherlands)

    Molenaar, W.F.; Voorendt, M.Z.

    This manual is the result of group work and origins in Dutch lecture notes that have been used since long time. Amongst the employees of the Hydraulic Engineering Department that contributed to this work are dr.ir. S. van Baars, ir.K.G.Bezuijen, ir.G.P.Bourguignon, prof.ir.A.Glerum,

  7. Water Treatment Technology - Hydraulics.

    Science.gov (United States)

    Ross-Harrington, Melinda; Kincaid, G. David

    One of twelve water treatment technology units, this student manual on hydraulics provides instructional materials for three competencies. (The twelve units are designed for a continuing education training course for public water supply operators.) The competencies focus on the following areas: head loss in pipes in series, function loss in…

  8. Experimental and numerical investigation of ram extrusion of bread dough

    Science.gov (United States)

    Mohammed, M. A. P.; Wanigasooriya, L.; Charalambides, M. N.

    2016-10-01

    An experimental and numerical study on ram extrusion of bread dough was conducted. A laboratory ram extrusion rig was designed and manufactured, where dies with different angles and exit radii were employed. Rate dependent behaviour was observed from tests conducted at different extrusion speeds, and higher extrusion pressure was reported for dies with decreasing exit radius. A finite element simulation of extrusion was performed using the adaptive meshing technique in Abaqus. Simulations using a frictionless contact between the billet and die wall showed that the model underestimates the response at high entry angles. On the other hand, when the coefficient of friction value was set to 0.09 as measured from friction experiments, the dough response was overestimated, i.e. the model extrusion pressure was much higher than the experimentally measured values. When a critical shear stress limit, τmax, was used, the accuracy of the model predictions improved. The results showed that higher die angles require higher τmax values for the model and the experiments to agree.

  9. The modification and application of RAMS computer code. Final report

    International Nuclear Information System (INIS)

    McKee, T.B.

    1995-01-01

    The Regional Atmospheric Modeling System (RAMS) has been utilized in its most updated form, version 3a, to simulate a case night from the Atmospheric Studies in COmplex Terrain (ASCOT) experimental program. ASCOT held a wintertime observational campaign during February, 1991 to observe the often strong drainage flows which form on the Great Plains and in the canyons embedded within the slope from the Continental Divide to the Great Plains. A high resolution (500 m grid spacing) simulation of the 4-5 February 1991 case night using the more advanced turbulence closure now available in RAMS 3a allowed greater analysis of the physical processes governing the drainage flows. It is found that shear interaction above and within the drainage flow are important, and are overpredicted with the new scheme at small grid spacing (< ∼1000 m). The implication is that contaminants trapped in nighttime stable flows such as these, will be mixed too strongly in the vertical reducing predicted ground concentrations. The HYPACT code has been added to the capability at LANL, although due to the reduced scope of work, no simulations with HYPACT were performed

  10. Characterization of Malaysian Trichoderma isolates using random amplified microsatellites (RAMS).

    Science.gov (United States)

    Siddiquee, Shafiquzzaman; Tan, Soon Guan; Yusuf, Umi Kalsom; Fatihah, Nur Hasan Nudin; Hasan, Md Mainul

    2012-01-01

    Trichoderma species are commercially applied as biocontrol agents against numerous plant pathogenic fungi due to their production of antifungal metabolites, competition for nutrients and space, and mycoparasitism. However, currently the identification of Trichoderma species from throughout the world based on micro-morphological descriptions is tedious and prone to error. The correct identification of Trichoderma species is important as several traits are species-specific. The Random Amplified Microsatellites (RAMS) analysis done using five primers in this study showed different degrees of the genetic similarity among 42 isolates of this genus. The genetic similarity values were found to be in the range of 12.50-85.11% based on a total of 76 bands scored in the Trichoderma isolates. Of these 76 bands, 96.05% were polymorphic, 3.95% were monomorphic and 16% were exclusive bands. Two bands (250 bp and 200 bp) produced by primer LR-5 and one band (250 bp) by primer P1A were present in all the Trichoderma isolates collected from healthy and infected oil palm plantation soils. Cluster analysis based on UPGMA of the RAMS marker data showed that T. harzianum, T. virens and T. longibrachiatum isolates were grouped into different clades and lineages. In this study we found that although T. aureoviride isolates were morphologically different when compared to T. harzianum isolates, the UPGMA cluster analysis showed that the majority isolates of T. aureoviride (seven from nine) were closely related to the isolates of T. harzianum.

  11. Differential gene expression by RamA in ciprofloxacin-resistant Salmonella Typhimurium.

    Directory of Open Access Journals (Sweden)

    Jie Zheng

    Full Text Available Overexpression of ramA has been implicated in resistance to multiple drugs in several enterobacterial pathogens. In the present study, Salmonella Typhimurium strain LTL with constitutive expression of ramA was compared to its ramA-deletion mutant by employing both DNA microarrays and phenotype microarrays (PM. The mutant strain with the disruption of ramA showed differential expression of at least 33 genes involved in 11 functional groups. The study confirmed at the transcriptional level that the constitutive expression of ramA was directly associated with increased expression of multidrug efflux pump AcrAB-TolC and decreased expression of porin protein OmpF, thereby conferring multiple drug resistance phenotype. Compared to the parent strain constitutively expressing ramA, the ramA mutant had increased susceptibility to over 70 antimicrobials and toxic compounds. The PM analysis also uncovered that the ramA mutant was better in utilization of 10 carbon sources and 5 phosphorus sources. This study suggested that the constitutive expression of ramA locus regulate not only multidrug efflux pump and accessory genes but also genes involved in carbon metabolic pathways.

  12. Design of a 16 kbit superconducting latching/SFQ hybrid RAM

    International Nuclear Information System (INIS)

    Nagasawa, Shuichi; Hasegawa, Haruhiro; Hashimoto, Tatsunori; Suzuki, Hideo; Miyahara, Kazunori; Enomoto, Youichi

    1999-01-01

    We have designed a 16 kbit superconducting latching/SFQ hybrid (SLASH) RAM, which enables high-frequency clock operation up to 10 GHz. The 16 kbit SLASH RAM consists of four 4x4 matrix arrays of 256 bit RAM blocks, block decoders, latching block drivers, latching block senses, impedance matched lines and the powering circuits. The 256 bit RAM block is composed of a 16x16 matrix array of vortex transitional memory cells, latching drivers, SFQ NOR decoders and latching sense circuits. We have also designed and implemented an SFQ NOR decoder that is composed of magnetically coupled multi-input OR gates and RSFQ inverters. (author)

  13. Simulate speleogenesis processes with an approach based on fracturing and hydrogeological processes: effect of various hydraulic boundary conditions

    Science.gov (United States)

    Lafare, A.; Jourde, H.; Leonardi, V.; Pistre, S.; Dörfliger, N.

    2012-04-01

    the bases of groundwater flow and transport simulations. The polynomial parameters of the equation are calibrated with former speleogenesis studies (Dreybrodt 1996, Dreybrodt et al. 2005, Palmer 1991). The presented study involves two orthogonal families of fractures embedded in a carbonate matrix, in a mono-stratum setting. For each simulation, several settings of boundary conditions are tested, in terms of recharge (diffuse or concentrated, hydraulic head or flux limited) and discharge (spatial position, punctual or diffuse). The results are interpreted in terms of head fields, mean groundwater age distributions and total flow rates as a function of time. The aim is to assess the influence of the hydraulic boundary conditions on the finally obtained morphologies of the karstic networks, and on the velocity of the evolution of the drainage system. Results are discussed and perspectives are given on the application of such model to real case studies.

  14. Use of Hydraulic Model for Water Loss Reduction

    OpenAIRE

    Mindaugas Rimeika; Anželika Jurkienė

    2016-01-01

    Hydraulic modeling is the modern way to apply world water engineering experience in every day practice. Hydraulic model is an effective tool in order to perform analysis of water supply system, optimization of its operation, assessment of system efficiency potential, evaluation of water network development, fire flow capabilities, energy saving opportunities and water loss reduction and ect. Hydraulic model shall include all possible engineering elements and devices allocated in a real water ...

  15. Hydraulic fracture conductivity: effects of rod-shaped proppant from lattice-Boltzmann simulations and lab tests

    Science.gov (United States)

    Osiptsov, Andrei A.

    2017-06-01

    The goal of this study is to evaluate the conductivity of random close packings of non-spherical, rod-shaped proppant particles under the closure stress using numerical simulation and lab tests, with application to the conductivity of hydraulic fractures created in subterranean formation to stimulate production from oil and gas reservoirs. Numerical simulations of a steady viscous flow through proppant packs are carried out using the lattice Boltzmann method for the Darcy flow regime. The particle packings were generated numerically using the sequential deposition method. The simulations are conducted for packings of spheres, ellipsoids, cylinders, and mixtures of spheres with cylinders at various volumetric concentrations. It is demonstrated that cylinders provide the highest permeability among the proppants studied. The dependence of the nondimensional permeability (scaled by the equivalent particle radius squared) on porosity obtained numerically is well approximated by the power-law function: K /Rv2 = 0.204ϕ4.58 in a wide range of porosity: 0.3 ≤ ϕ ≤ 0.7. Lattice-Boltzmann simulations are cross-verified against finite-volume simulations using Navier-Stokes equations for inertial flow regime. Correlations for the normalized beta-factor as a function of porosity and normalized permeability are presented as well. These formulae are in a good agreement with the experimental measurements (including packings of rod-shaped particles) and existing laboratory data, available in the porosity range 0.3 ≤ ϕ ≤ 0.5. Comparison with correlations by other authors is also given.

  16. Effect of hydraulic retention time on biohydrogen and volatile fatty acids production during acidogenic digestion of dephenolized olive mill wastewaters

    International Nuclear Information System (INIS)

    Scoma, Alberto; Bertin, Lorenzo; Fava, Fabio

    2013-01-01

    The influence of Hydraulic Retention Time (HRT) on the performances of a recently developed biotechnological anaerobic acidogenic process fed with dephenolized Olive Mill Wastewater (OMW) was investigated. The study was carried out under mesophilic conditions in Packed Bed Biofilm Reactors (PBBRs), filled with ceramic cubes and inoculated with a characterized and acclimated acidogenic microbial consortium. The PBBRs were fed with a HRT of 7, 5, 3 or 1 day, which corresponded to Organic Loading Rates (OLRs) of about 5.5, 7.8, 12.9 and 38.8 g L −1 d −1 , respectively. A significant production of a H 2 -rich biogas was observed when shorter HRTs were applied: in particular, H 2 relative amount and productivity increased from 3% to 32% and from 0.20 to 6.10 dm 3 m −3 h −1 , respectively, by decreasing the HRT from 7 to 1 day. On the contrary, shorter HRTs turned into a lower accumulation of Volatile Fatty Acids (VFAs), whose highest amounts were found with HRTs of 7 and 5 days (about 18.4 and 19.7 g L −1 COD equivalents, respectively). The highest conversion yield of COD into VFAs (36%) was obtained with a HRT of 5 days, when VFAs represented about 78% of the effluent COD. HRT also influenced the composition of the VFA mixture: acetic, propionic and butyric acid were the most prominent VFAs, being their relative amounts higher when PBBRs were operated with shorter HRTs (up to 19, 12 and 42% of the whole mixture, respectively, when HRT was 1 day). -- Highlights: ► HRT affects the acidogenic digestion of dephenolized olive mill wastewater. ► A significant production of bioH 2 can be coupled to that of volatile fatty acids. ► Higher H 2 and lower VFA productions were obtained by shortening the HRT

  17. Ethylene glycol, but not DMSO, could replace glycerol inclusion in soybean lecithin-based extenders in ram sperm cryopreservation.

    Science.gov (United States)

    Najafi, Abouzar; Daghigh-Kia, Hossein; Dodaran, Hossein Vaseghi; Mehdipour, Mahdieh; Alvarez-Rodriguez, Manuel

    2017-02-01

    The aim of this study was to evaluate the effects of glycerol, ethylene glycol or DMSO in a soybean lecithin extender for freezing ram semen. In this study, 20 ejaculates were collected from four Ghezel rams and diluted with soybean lecithin extender with glycerol (7%), ethylene glycol (3%, 5% and 7%) or DMSO (3%, 5% and 7%). Sperm motility (CASA), membrane integrity (HOS test), viability, total abnormality, mitochondrial activity (Rhodamine 123) and apoptotic features (Annexin V/Propidium iodide) were assessed after thawing. There was no significant difference between glycerol and ethylene glycol at different concentrations (3% and 5%) regarding sperm total and progressive motility, viability, and membrane integrity. The least percentages of mitochondrial functionality were observed in samples frozen with all different DMSO concentrations tested (Plecithin extender. We propose that glycerol in a soybean lecithin based extender could be replaced by ethylene glycol at 3% or 5% concentrations. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. Estimation of the hydraulic conductivity of a two-dimensional fracture network using effective medium theory and power-law averaging

    Science.gov (United States)

    Zimmerman, R. W.; Leung, C. T.

    2009-12-01

    Most oil and gas reservoirs, as well as most potential sites for nuclear waste disposal, are naturally fractured. In these sites, the network of fractures will provide the main path for fluid to flow through the rock mass. In many cases, the fracture density is so high as to make it impractical to model it with a discrete fracture network (DFN) approach. For such rock masses, it would be useful to have recourse to analytical, or semi-analytical, methods to estimate the macroscopic hydraulic conductivity of the fracture network. We have investigated single-phase fluid flow through generated stochastically two-dimensional fracture networks. The centers and orientations of the fractures are uniformly distributed, whereas their lengths follow a lognormal distribution. The aperture of each fracture is correlated with its length, either through direct proportionality, or through a nonlinear relationship. The discrete fracture network flow and transport simulator NAPSAC, developed by Serco (Didcot, UK), is used to establish the “true” macroscopic hydraulic conductivity of the network. We then attempt to match this value by starting with the individual fracture conductances, and using various upscaling methods. Kirkpatrick’s effective medium approximation, which works well for pore networks on a core scale, generally underestimates the conductivity of the fracture networks. We attribute this to the fact that the conductances of individual fracture segments (between adjacent intersections with other fractures) are correlated with each other, whereas Kirkpatrick’s approximation assumes no correlation. The power-law averaging approach proposed by Desbarats for porous media is able to match the numerical value, using power-law exponents that generally lie between 0 (geometric mean) and 1 (harmonic mean). The appropriate exponent can be correlated with statistical parameters that characterize the fracture density.

  19. Hydraulic turbines and auxiliary equipment

    Energy Technology Data Exchange (ETDEWEB)

    Luo Gaorong [Organization of the United Nations, Beijing (China). International Centre of Small Hydroelectric Power Plants

    1995-07-01

    This document presents a general overview on hydraulic turbines and auxiliary equipment, emphasizing the turbine classification, in accordance with the different types of turbines, standard turbine series in China, turbine selection based on the basic data required for the preliminary design, general hill model curves, chart of turbine series and the arrangement of application for hydraulic turbines, hydraulic turbine testing, and speed regulating device.

  20. Hydraulic Hybrid Vehicle Publications | Transportation Research | NREL

    Science.gov (United States)

    Hydraulic Hybrid Vehicle Publications Hydraulic Hybrid Vehicle Publications The following technical papers and fact sheets provide information about NREL's hydraulic hybrid fleet vehicle evaluations . Refuse Trucks Project Startup: Evaluating the Performance of Hydraulic Hybrid Refuse Vehicles. Bob

  1. Hydraulic braking system for loads subjected to impacts and vibrations

    International Nuclear Information System (INIS)

    1980-01-01

    This invention concerns a hydraulic braking system for loads subjected to impacts and vibrations. These double acting telescopic type hydraulic braking systems possess significant drawbacks linked to possibly important hydraulic leaks due to (a) the use of many dynamic seals in such appliances and (b) the effects of the environment of the system on these seals, particularly when employed in nuclear power stations where the seals reach significant temperatures and are subjected to radiation. Under this invention a remedy is suggested to such drawbacks by integrating means to offset automatically the leaks and the accumulation of hydraulic fluid expansions, as well as facilities to show if such leaks have occurred [fr

  2. The hydraulic capacity of deteriorating sewer systems.

    Science.gov (United States)

    Pollert, J; Ugarelli, R; Saegrov, S; Schilling, W; Di Federico, V

    2005-01-01

    Sewer and wastewater systems suffer from insufficient capacity, construction flaws and pipe deterioration. Consequences are structural failures, local floods, surface erosion and pollution of receiving waters bodies. European cities spend in the order of five billion Euro per year for wastewater network rehabilitation. This amount is estimated to increase due to network ageing. The project CARE-S (Computer Aided RE-habilitation of Sewer Networks) deals with sewer and storm water networks. The final project goal is to develop integrated software, which provides the most cost-efficient system of maintenance, repair and rehabilitation of sewer networks. Decisions on investments in rehabilitation often have to be made with uncertain information about the structural condition and the hydraulic performance of a sewer system. Because of this, decision-making involves considerable risks. This paper presents the results of research focused on the study of hydraulic effects caused by failures due to temporal decline of sewer systems. Hydraulic simulations are usually carried out by running commercial models that apply, as input, default values of parameters that strongly influence results. Using CCTV inspections information as dataset to catalogue principal types of failures affecting pipes, a 3D model was used to evaluate their hydraulic consequences. The translation of failures effects in parameters values producing the same hydraulic conditions caused by failures was carried out through the comparison of laboratory experiences and 3D simulations results. Those parameters could be the input of 1D commercial models instead of the default values commonly inserted.

  3. Vibration Isolation for Parallel Hydraulic Hybrid Vehicles

    Directory of Open Access Journals (Sweden)

    The M. Nguyen

    2008-01-01

    Full Text Available In recent decades, several types of hybrid vehicles have been developed in order to improve the fuel economy and to reduce the pollution. Hybrid electric vehicles (HEV have shown a significant improvement in fuel efficiency for small and medium-sized passenger vehicles and SUVs. HEV has several limitations when applied to heavy vehicles; one is that larger vehicles demand more power, which requires significantly larger battery capacities. As an alternative solution, hydraulic hybrid technology has been found effective for heavy duty vehicle because of its high power density. The mechanical batteries used in hydraulic hybrid vehicles (HHV can be charged and discharged remarkably faster than chemical batteries. This feature is essential for heavy vehicle hybridization. One of the main problems that should be solved for the successful commercialization of HHV is the excessive noise and vibration involving with the hydraulic systems. This study focuses on using magnetorheological (MR technology to reduce the noise and vibration transmissibility from the hydraulic system to the vehicle body. In order to study the noise and vibration of HHV, a hydraulic hybrid subsystem in parallel design is analyzed. This research shows that the MR elements play an important role in reducing the transmitted noise and vibration to the vehicle body. Additionally, locations and orientations of the isolation system also affect the efficiency of the noise and vibration mitigation. In simulations, a skyhook control algorithm is used to achieve the highest possible effectiveness of the MR isolation system.

  4. Laser Boost of a Small Interstellar Ram Jet to Obtain Operational Velocity. Implications for the DM Rocket/Ram Jet Model

    Science.gov (United States)

    Walcott Beckwith, Andrew

    2010-05-01

    In other conference research papers, Beckwith obtained a maximum DM mass/energy value of up to 5 TeV, as opposed to 400 GeV for DM, which may mean more convertible power for a dark matter ram jet. The consequences are from assuming that axions are CDM, and KK gravitons are for WDM, then ρWarm-Dark-Matter would dominate not only structure formation in early universe formation, but would also influence the viability of the DM ram jet applications for interstellar travel. The increase in convertible DM mass makes the ram jet a conceivable option. This paper in addition to describing the scientific issues leading to that 5 TeV mass for DM also what are necessary and sufficient laser boost systems which would permit a ram net to become operational.

  5. THE PROPORTION OF X AND Y SPERM, VIABILITY AND MOTILITY OF RAM SPERMATOZOA AFTER SEPARATED WITH WHITE EGG ALBUMIN

    Directory of Open Access Journals (Sweden)

    Moh Takdir

    2017-02-01

    The aim of this research was to determine the proportion, viability and motility of X and Y ram spermatozoa separated with egg white albumin. Sperm samples derived from Garut ram, which was collected by using an artificial vagina. Observations were made on spermatozoa fraction above and below each medium fraction treatment. There are treatment egg white albumin as separation medium, each medium consisting of fractions top and bottom fraction with different concentration: 1 P0 = sperma before separation (control; 2 P1 = 10% above fraction + 30% lower fraction; P2 = 25% + 45%; P3 = 25% + 75%. Data proportion of X and Y, viability and motility were analyzed statistically by Completely Randomized Design patern in the direction followed by Duncan’s Multiple Range Test for data with a real difference. Separation with egg white albumin affect significantly increased the proportion of spermatozoa X and Y (P≤0.05, but tends to decrease the viability and motility of spermatozoa.The proportion of spermatozoa X and Y was highest in treatment P3,76.76% of spermatozoa X (fraction above 25% and 79.81% spermatozoa Y (75% lower fraction, with an average viability obtained respectively 68,9% (fraction above and 59,7% (bottom fraction, motility 77,5% (fraction above dan 84,0% (bottom fraction. It was concluded that the egg white albumin is very effective in changing the proportions of X and Y ram sperm with the quality of spermatozoa after separation feasible for applications insemination or processed into frozen semen.   (Keywords: Garut ram, White egg albumin, Spermatozoa X and Y

  6. Hydraulic manipulator research at ORNL

    International Nuclear Information System (INIS)

    Kress, R.L.; Jansen, J.F.; Love, L.J.

    1997-01-01

    Recently, task requirements have dictated that manipulator payload capacity increase to accommodate greater payloads, greater manipulator length, and larger environmental interaction forces. General tasks such as waste storage tank cleanup and facility dismantlement and decommissioning require manipulator life capacities in the range of hundreds of pounds rather than tens of pounds. To meet the increased payload capacities demanded by present-day tasks, manipulator designers have turned once again to hydraulics as a means of actuation. In order to successfully design, build, and deploy a new hydraulic manipulator (or subsystem), sophisticated modeling, analysis, and control experiments are usually needed. Oak Ridge National Laboratory (ORNL) has a history of projects that incorporate hydraulics technology, including mobile robots, teleoperated manipulators, and full-scale construction equipment. In addition, to support the development and deployment of new hydraulic manipulators, ORNL has outfitted a significant experimental laboratory and has developed the software capability for research into hydraulic manipulators, hydraulic actuators, hydraulic systems, modeling of hydraulic systems, and hydraulic controls. The purpose of this article is to describe the past hydraulic manipulator developments and current hydraulic manipulator research capabilities at ORNL. Included are example experimental results from ORNL's flexible/prismatic test stand

  7. Hydraulic manipulator research at ORNL

    Energy Technology Data Exchange (ETDEWEB)

    Kress, R.L.; Jansen, J.F. [Oak Ridge National Lab., TN (United States); Love, L.J. [Oak Ridge Inst. for Science and Education, TN (United States)

    1997-03-01

    Recently, task requirements have dictated that manipulator payload capacity increase to accommodate greater payloads, greater manipulator length, and larger environmental interaction forces. General tasks such as waste storage tank cleanup and facility dismantlement and decommissioning require manipulator life capacities in the range of hundreds of pounds rather than tens of pounds. To meet the increased payload capacities demanded by present-day tasks, manipulator designers have turned once again to hydraulics as a means of actuation. In order to successfully design, build, and deploy a new hydraulic manipulator (or subsystem), sophisticated modeling, analysis, and control experiments are usually needed. Oak Ridge National Laboratory (ORNL) has a history of projects that incorporate hydraulics technology, including mobile robots, teleoperated manipulators, and full-scale construction equipment. In addition, to support the development and deployment of new hydraulic manipulators, ORNL has outfitted a significant experimental laboratory and has developed the software capability for research into hydraulic manipulators, hydraulic actuators, hydraulic systems, modeling of hydraulic systems, and hydraulic controls. The purpose of this article is to describe the past hydraulic manipulator developments and current hydraulic manipulator research capabilities at ORNL. Included are example experimental results from ORNL`s flexible/prismatic test stand.

  8. Thermal-Hydraulic Integral Effect Test with ATLAS for an Intermediate Break Loss of Coolant Accident at a Pressurizer Surge Line

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Kyoung Ho; Seok Cho; Park, Hyun Sik; Choi, Nam Hyun; Park, Yu Sun; Kim, Jong Rok; Bae, Byoung Uhn; Kim, Yeon Sik; Kim, Kyung Doo; Choi, Ki Yong; Song, Chul Hwa [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2013-10-15

    The main objectives of this test were not only to provide physical insight into the system response of the APR1400 during the pressurizer surge line break accident but also to produce an integral effect test data to validate the SPACE code. In order to simulate a double-ended guillotine break of a pressurizer surge line in the APR1400, the IB-SUR-01R test was performed with ATLAS. The major thermal-hydraulic phenomena such as the system pressures, the collapsed water levels, and the break flow rate were presented and discussed. Despite the core was uncovered, no excursion in the cladding temperature was observed. The pressurizer surge line break can be classified as a hot leg break from a break location point of view. Compared with a cold leg break, coolability in the core may be better in case of a hot leg break due to the enhanced flow in the core region. This integral effect test data will be used to evaluate the prediction capability of existing safety analysis codes of the MARS and the RELAP5 as well as the SPACE code. Furthermore, this data can be utilized to identify any code deficiency for an IBLOCA simulation, especially for DVI-adapted plants. Redefinition of break size for design basis accident (DBA) based on risk information is being extensively investigated due to the potential for safety benefits and unnecessary burden reduction from current LBLOCA (large break loss of coolant accident)-based ECC (Emergency Core Cooling) Acceptance Criteria. As a transition break size (TBS), the rupture of medium-size pipe is considered to be more important than ever in risk-informed regulation (RIR)-relevant safety analysis. As plants age, are up-rated, and continue to seek improved operating efficiencies, the small break and intermediate break LOCA (IBLOCA) can become a concern. In particular, IBLOCA with DVI (Direct Vessel Injection) features will be addressed to support redefinition of a design-basis LOCA. With an aim of expanding code validation to address small

  9. Mechanics of Hydraulic Fractures

    Science.gov (United States)

    Detournay, Emmanuel

    2016-01-01

    Hydraulic fractures represent a particular class of tensile fractures that propagate in solid media under pre-existing compressive stresses as a result of internal pressurization by an injected viscous fluid. The main application of engineered hydraulic fractures is the stimulation of oil and gas wells to increase production. Several physical processes affect the propagation of these fractures, including the flow of viscous fluid, creation of solid surfaces, and leak-off of fracturing fluid. The interplay and the competition between these processes lead to multiple length scales and timescales in the system, which reveal the shifting influence of the far-field stress, viscous dissipation, fracture energy, and leak-off as the fracture propagates.

  10. High-speed nonvolatile CMOS/MNOS RAM

    International Nuclear Information System (INIS)

    Derbenwick, G.F.; Dodson, W.D.; Sokel, R.J.

    1979-01-01

    A bulk silicon technology for a high-speed static CMOS/MNOS RAM has been developed. Radiation-hardened, high voltage CMOS circuits have been fabricated for the memory array driving circuits and the enhancement-mode p-channel MNOS memory transistors have been fabricated using a native tunneling oxide with a 45 nm CVD Si 3 N 4 insulator deposited at 750 0 C. Read cycle times less than 350 ns and write cycle times of 1 μs are projected for the final 1Kx1 design. The CMOS circuits provide adequate speed for the write and read cycles and minimize the standby power dissipation. Retention times well in excess of 30 min are projected

  11. NGC 4438: Ram pressure sweeping of a tidally disrupted galaxy

    International Nuclear Information System (INIS)

    Hibbard, J.E.; Vangorkom, J.H.

    1990-01-01

    NGC 4438 is the highly HI deficient peculiar spiral in the center of the Virgo cluster. Observations are given of the neutral hydrogen emission obtained with the Very Large Array (VLA) in the D-array configuration. These observations map out the total HI as determined from single dish measurements, and show the hydrogen to be confined to a region about one third the size of the optical disk and displaced to the side of the galaxy opposite M87. The hydrogen content of the galaxy is over an order of magnitude less than that expected for a galaxy of its type. The data suggest that the HI deficiency is a result of ram pressure stripping of the gas in the outer regions of the galaxy by the hot intracluster medium after being tidally perturbed

  12. Undular Hydraulic Jump

    Directory of Open Access Journals (Sweden)

    Oscar Castro-Orgaz

    2015-04-01

    Full Text Available The transition from subcritical to supercritical flow when the inflow Froude number Fo is close to unity appears in the form of steady state waves called undular hydraulic jump. The characterization of the undular hydraulic jump is complex due to the existence of a non-hydrostatic pressure distribution that invalidates the gradually-varied flow theory, and supercritical shock waves. The objective of this work is to present a mathematical model for the undular hydraulic jump obtained from an approximate integration of the Reynolds equations for turbulent flow assuming that the Reynolds number R is high. Simple analytical solutions are presented to reveal the physics of the theory, and a numerical model is used to integrate the complete equations. The limit of application of the theory is discussed using a wave breaking condition for the inception of a surface roller. The validity of the mathematical predictions is critically assessed using physical data, thereby revealing aspects on which more research is needed

  13. Design of a ram accelerator mass launch system

    Science.gov (United States)

    Aarnio, Michael; Armerding, Calvin; Berschauer, Andrew; Christofferson, Erik; Clement, Paul; Gohd, Robin; Neely, Bret; Reed, David; Rodriguez, Carlos; Swanstrom, Fredrick

    1988-01-01

    The ram accelerator mass launch system has been proposed to greatly reduce the costs of placing acceleration-insensitive payloads into low earth orbit. The ram accelerator is a chemically propelled, impulsive mass launch system capable of efficiently accelerating relatively large masses from velocities of 0.7 km/sec to 10 km/sec. The principles of propulsion are based on those of a conventional supersonic air-breathing ramjet; however the device operates in a somewhat different manner. The payload carrying vehicle resembles the center-body of the ramjet and accelerates through a stationary tube which acts as the outer cowling. The tube is filled with premixed gaseous fuel and oxidizer mixtures that burn in the vicinity of the vehicle's base, producing a thrust which accelerates the vehicle through the tube. This study examines the requirement for placing a 2000 kg vehicle into a 500 km circular orbit with a minimum amount of on-board rocket propellant for orbital maneuvers. The goal is to achieve a 50 pct payload mass fraction. The proposed design requirements have several self-imposed constraints that define the vehicle and tube configurations. Structural considerations on the vehicle and tube wall dictate an upper acceleration limit of 1000 g's and a tube inside diameter of 1.0 m. In-tube propulsive requirements and vehicle structural constraints result in a vehicle diameter of 0.76 m, a total length of 7.5 m and a nose-cone half angle of 7 degrees. An ablating nose-cone constructed from carbon-carbon composite serves as the thermal protection mechanism for atmospheric transit.

  14. The Effect Of Ocimum Gratissimum (Ram Tulsi) On Sexual ...

    African Journals Online (AJOL)

    The suspension of the extract of Ocimum gratissimum Linn. was administered orally at the dose of 100, 250, and 500 mg / kg body weight, to different groups of male rats (n = 6) once a day for seven days. The female Swiss Albino mice involved in mating were made receptive by hormonal treatment. The general mating ...

  15. Uudised : Hortus Musicus Moskvas. TPÜ naiskoor koorikonkursil. RAM samal laval Mark Knopfleriga. "Tuuleveskid. Kerkokell" / Joosep Sang

    Index Scriptorium Estoniae

    Sang, Joosep

    2000-01-01

    Hortus Musicus esines 23. ja 24. nov. Moskvas. TPÜnaiskoor võitis II preemia XVII rahvusvahelisel F.Schuberti nim. koorikonkursil Austrias. RAM esineb 8. dets. Helsingis Hartwall Areenas heategevuskontserdil. RAM esineb 6. dets. Estonia kontserdisaalis kavaga "Tuuleveskid. Kerkokell"

  16. RANGE RAM: a long-term planning method for managing grazing lands

    Science.gov (United States)

    Henricus C. Jansen

    1976-01-01

    Range RAM (Resource Allocation Method) is a computerized planning method designed to assist range managers in developing and selecting alternatives in spatial and temporal allocation of resources. The technique is applicable at the frest or district management levels, or their equivalents. Range RAM can help formulate plans that maximize the production of range outputs...

  17. A Simplified Model of an Offset Ram Press for Sunflower Oil ...

    African Journals Online (AJOL)

    This paper presents the theoretical analysis of a simplified model of a ram press. The design of the ram press is based on the classical slider-crank mechanism. A force analysis of the press was performed for several successive positions of the driving lever (handle) and for a range of values of certain dimensionless ...

  18. Numerical simulation of the direct contact condensation phenomena for PTS-related in single and combined-effect thermal hydraulic test facilities using TransAT CMFD code

    Energy Technology Data Exchange (ETDEWEB)

    Kadi, Rabah, E-mail: kadi.rkhaled@hotmail.com [Laboratory for Thermal-Hydraulics, Nuclear Research Center of Birine (Algeria); Aissani, Slimane [Hydrocarbons and Chemistry Faculty, University of Boumerdes (Algeria); Bouam, Abdellah [Laboratory for Thermal-Hydraulics, Nuclear Research Center of Birine (Algeria)

    2015-11-15

    Highlights: • TransAT CMFD code application to DCC phenomenon. • LEIS methodology to predict the condensing steam flow rate. • Validation of interfacial phase-change heat transfer and turbulence models. • Correction of damping function at the free surface region. • Numerical validation of previous models using LIM and KAERI & KAIST test facilities. - Abstract: The use of CFD for the industrial studies related to PTS, including DCC is already possible; improvements of the two-phase modeling capabilities have to be undertaken to qualify the codes for the simulation of such flows. The DCC in horizontally stratified flow regime constitutes very considerable challenge exercises for a computational fluid dynamics (CFD) simulation of the thermal hydraulics PTS phenomenon because the interplay between turbulence and interfacial heat and mass transfer problem. The main purpose of our study is to investigate numerically the DCC in horizontally stratified steam water flow in a 2D and 3D channel using TransAT CMFD code. The new methodology known as Large-Eddy & Interface (LEIS) have been implemented for treatment of turbulence combined with interface tracking ITM (level set approach). Among of the so-called ‘coarse-grained’ ITM's models, the modified original surface divergence has been chosen as well as the treatment of the turbulence by URANS and VLES. This contribution addressed on the validation of interfacial phase-change heat transfer and turbulence models with special correction of the damping function at the free surface for single and combined-effect thermal hydraulic studies for LIM and KAERI & KAIST test facilities. The LIES methodology was found to apply successfully to predict the condensing steam flow rate in the all cases of the LIM test case involving a Smooth to Wavy turbulent, concurrent stratified steam-water flow in a 2D channel. The CMFD TransAT code predicting capability is analyzed, comparing the liquid temperature and to much the

  19. Endurance Pump Tests With Fresh and Purified MIL-PRF-83282 Hydraulic Fluid

    National Research Council Canada - National Science Library

    Sharma, Shashi

    1999-01-01

    .... Two endurance pump tests were conducted with F-16 aircraft hydraulic pumps, using both fresh and purified MIL-PRF-83282 hydraulic fluid, to determine if fluid purification had any adverse effect on pump life...

  20. Preference of redear sunfish on zebra mussels and rams-horn snails

    Science.gov (United States)

    French, John R. P.; Morgan, Michael N.

    1995-01-01

    We tested prey preferences of adult (200- to 222-mm long) redear sunfish (Lepomis microlophus) on two size classes of zebra mussels (Dreissena polymorpha) and two-ridge rams-horns (Helisoma anceps) in experimental aquaria. We also tested physical limitations on consuming these mollusks and determined prey bioenergetic profitability. Redear sunfish strongly preferred rams-horns over zebra mussels, but they displayed no size preference for either prey. Ingestion was not physically limited since both prey species up to 15-mm long fit within the pharyngeal gapes of redear sunfish. Rams-horns were more bioenergetically profitable than zebra mussels and ingestion of rams-horn shell fragments was about three times less than zebra mussels. Rams-horns were somewhat more resistant to shell-crushing, but all size ranges of both prey species tested were crushable by redear sunfish. These studies suggested that the redear sunfish should not be considered a panacea for biological control of zebra mussels.