WorldWideScience

Sample records for horizontal stress direction

  1. Difference in the Minimum Horizontal Stress Magnitudes Between Direct Measurements and Poroelastic Equation-Based Calculation

    Science.gov (United States)

    Vo, U. D.; Chang, C.

    2016-12-01

    Horizontal stress profile with depth is needed for hydraulic fracture design, wellbore stability analysis, and sanding potential assessment. While vertical stress (Sv) can be calculated from overburden, horizontal stresses normally have to be measured. A conventional alternative is to use a linear poroelasticity equation derived based on the assumption of uniaxially strained basins, which gives minimum horizontal stress magnitude (Shmin) as a function of Sv, pore pressure and Poisson's ratio (ν). In order to check the reliability of the equation, we compare the calculated Shmin with measured values through e.g., leak-off tests (LOT). We compile Shmin and pore pressure data from 6 major petroleum fields worldwide (Cuu Long basin, offshore Vietnam; Champion field, offshore Brunei; Visund field, North Sea; Gippsland basin, offshore SE Australia; St. Lawrence Lowlands basin, East Canada; Popeye basin, Gulf of Mexico) for this comparison. For calculation of Shmin via the equation, we assume ν of 0.25 and Biot's constant of unity. The comparison shows that the calculated Shmin values generally underestimate the measured values by a range between 4% and as much as 29% depending on the regions. We attempt to explain qualitatively the gaps between the measured and the calculated Shmin (ΔShmin) in terms of tectonic stress. In Cuu Long, although tectonically active, ΔShmin is quite low (4%) throughout the 4.3 km depth investigated. In contrast, Visund and St. Lawrence Lowlands, although tectonically stable, show appreciable ΔShmin (average 9% and 22% respectively). These results imply that ΔShmin may not depend solely on tectonic stress. In Popeye where tectonics is active, ΔShmin is as high as 24%. Popeye is the only one among the fields investigated that exhibits high ΔShmin likely attributed to tectonic stress. The measured Shmin values in Champion and Gippsland are so scattered that any prediction on magnitudes might not be feasible. The wide variation of

  2. Exploration of joint systems and major horizontal stress direction in HDR drillholes of the Soultz site (Alsace, France)

    Energy Technology Data Exchange (ETDEWEB)

    Genter, A. [BRGM/GIG, Orleans (France); Tenzer, H. [Stadtwerke Bad Urach (Germany)

    1997-12-01

    Borehole imaging logs enable continuous recording of natural and artificial planar discontinuities on the drillhole wall and data of the drillhole geometry to be made. Efforts were made to resolve the orientation and characterization of the natural joint system, the active fault pattern, the alteration zones, the orientation of microcracks and the direction of maximum horizontal stress. Intense logging operations and measurements were carried out in the HDR drillholes GPK1 and EPS1 between 1000 and 3600 m depth in the Muschelkalk, Bunter and Granite at Soultz sous Forets. With the help of investigations on subvertical fractures the orientation of the maximum horizontal stress direction was determined as N175 E{+-}17 . These results are consistent with previous investigations performed in the horeholes GPK-1 and EPS-1. (orig./AKF) [Deutsch] Bohrlochmessungen mit dem akustschen Borehole Televiewer und elektrischen Formation MicroScanner (Imager) sowie dem Azimuthal Resistivity Imager und verschiedenen Sonic-Sonden ermoeglichen eine kontinuierliche Aufnahme sowohl von natuerlichen und kuenstlich erzeugten planaren Diskontinuitaeten an der Bohrlochwand als auch der Bohrlochgeometrie. Es wurden die Orientierung und Charakterisierung des natuerlichen Kluftsystems, das aktive Stoerungsmuster, die Alterationszonen, die Orientierung von Mikrorissen und die Orientierung der maximalen horizontalen Hauptspannungsrichtung ermittelt. Die Verfuegbarkeit von Strukturdaten aus Bohrloechern durch Bohrlochmessungen und hydraulischen Testen ermoeglicht die Bestimmung von hydraulisch aktiven Klueften und deren Beziehung zum regionalen Spannungsfeld. Mit Hilfe spezieller Bohrloch-Logs wurden die Orientierung und Haeufigkeit planarer Diskontinuitaeten und ihre scheinbare Oeffnungsweite sowie die Vorzugsrichtung der verschiedenen scheinbaren Weiten bestimmt. Innerhalb des gemeinsamen europaeischen Hot-Dry-Rock-Geothermal-Forschungsprogramms wurden vielfaeltige Bohrlochmessungen in den

  3. Moment tensor inversion for moderate earthquakes and horizontal direction of tectonic stress in and around the south korea peninsula

    Science.gov (United States)

    Cho, ChangSoo

    2015-04-01

    Moment tensor inversion method using waveform is not widely used in identification of fault direction for earthquake but also in identification of explosion experiment such as north korea nuclear test. TDMT inversion code as open source was used for 1-D focal mechanism to moderate earthquake. But TDMT code caused some problems to fit waveform data of earthquake. This software was modified and improved with using the extraction bandwidth for event data and using waveform fitting of maximum cross-correlation with limit of shifting time. Improved algorithm was applied to moderate earthquakes occurred in and around the korean peninsula and showed the result of good data fitting in deriving focal mechanism. CMT centeroid locations were calculated with this algorithm. Earthquakes occurred rarely in the korean peninsula and instrumental recording started from 1990's late. But quality of measurement ground motion is very good after the beginning of instrumental recording. 61 moderate earthquakes occurred analyzed between 2000 to present were analyzed. most of all focal mechanism of earthquake showed strike slip or reverse fault as intraplate earthquake. The horizontal direction of tectonic stress of the korean peninsula is ENE-WSW derived with focal mechanisms that were calculated with 1D moment tensor inversion for moderate earthquake by Zoback(1992)'s method of tectonic stress. 3D-moment tensor inversion method was also developed with simulation code of 3-D viscoelastic finite difference method with ADE(auxiliary differential equation)-PML(perfectly matched layer) and applied to main moderate earthquakes. Forward modeling of 3D seismic wave propagation for moment tensor inversion require much time and expensive cost. Forward simulation with domain decomposition of having only thin model between source and receiver in moment tensor inversion could reduce much time, memory and computational cost in 3D moment tensor inversion even though this method was not more effective

  4. Horizontal stresses below two agricultural vehicles

    DEFF Research Database (Denmark)

    Lamande, Mathieu André Maurice; Munkholm, Lars Juhl; Nielsen, Janne Aalborg

    below the edge of tires. Stress distribution at the tire/soil contact is not uniform. Dimensions and inflation pressure are key factors for the ability of agricultural tires to distribute the wheel load. Our hypothesis was that the risk of shearing increases with the tire inflation pressure...... and the number of wheels. We measured horizontal stress at two depths (0.3 and 0.5 m) below tires of two slurry spreaders: one self-propelled machine equipped with wide tires (1.050 m) and low inflation pressure (150 kPa) but carrying a high wheel load (120 kN), and one tractor towing a three-axle slurry...... confounded (wheel load, inflation...

  5. The 'horizontal direct effect' of EU international agreements

    DEFF Research Database (Denmark)

    Gáspár-Szilágyi, Szilárd

    2015-01-01

    in proceedings involving private individuals/professionals against the private regulatory bodies of a profession or a State owned and controlled entity. However, direct effect has not yet been expressly confirmed in cases involving veritable horizontal relationships, between private parties of equal positions...

  6. Research and application on the horizontal tectonic stress influence on the stability of deep roadway

    Science.gov (United States)

    CAO, Jian-jun; YAO, Zhuang-zhuang

    2017-04-01

    According to the test result of ground stress of -817.0m Horizontal shaft station in Huainan mine area, the stress field distribution characteristic of mainly with horizontal tectonic stress was analyzed, the deep roadway surrounding rock deformation and failure regularity under the situation of the maximum horizontal stress and roadway axis in the different angle were studied by using the FLAC3D simulation software, and then specific way of supporting and its parameters were designed combined with the shaft station layout conditions. The result shows that: the roadway stability is relatively good when its tunnel axis the maximum horizontal stress direction within 30° angle, surrounding rock deformation and the plastic zone at the top and bottom are significantly increasing along with the angle increased from 30° to 90°, the major form of deep soft rock deformation and failure is the floor heave. According to the simulation results, the conditions under the layout condition of the shaft station roadway, support methods and support parameters have been designed and determined. The supporting method can be referenced by the similar mines.

  7. Horizontal Directional Drilling (HDD) for shore approach applications

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Neil [MGI do Brasil Ltda., Rio de Janeiro, RJ (Brazil)

    2003-07-01

    Horizontal directional drilling (HDD) has become a commonly used construction method for pipeline shore approaches. HDD can mitigate environmental impact, provide greater burial depths and minimize construction schedules. The risks that are associated with HDD river crossings, which are generally well recognized, also apply to HDD shore approaches where they are combined with specific risks occurring from working in the marine environment. The shore approach projects of The Bronx and Hunts Point provide good practical examples of the benefits of this technology in spite of the various challenges encountered. (author)

  8. Effect of occlusion, directionality and age on horizontal localization

    Science.gov (United States)

    Alworth, Lynzee Nicole

    Localization acuity of a given listener is dependent upon the ability discriminate between interaural time and level disparities. Interaural time differences are encoded by low frequency information whereas interaural level differences are encoded by high frequency information. Much research has examined effects of hearing aid microphone technologies and occlusion separately and prior studies have not evaluated age as a factor in localization acuity. Open-fit hearing instruments provide new earmold technologies and varying microphone capabilities; however, these instruments have yet to be evaluated with regard to horizontal localization acuity. Thus, the purpose of this study is to examine the effects of microphone configuration, type of dome in open-fit hearing instruments, and age on the horizontal localization ability of a given listener. Thirty adults participated in this study and were grouped based upon hearing sensitivity and age (young normal hearing, >50 years normal hearing, >50 hearing impaired). Each normal hearing participant completed one localization experiment (unaided/unamplified) where they listened to the stimulus "Baseball" and selected the point of origin. Hearing impaired listeners were fit with the same two receiver-in-the-ear hearing aids and same dome types, thus controlling for microphone technologies, type of dome, and fitting between trials. Hearing impaired listeners completed a total of 7 localization experiments (unaided/unamplified; open dome: omnidirectional, adaptive directional, fixed directional; micromold: omnidirectional, adaptive directional, fixed directional). Overall, results of this study indicate that age significantly affects horizontal localization ability as younger adult listeners with normal hearing made significantly fewer localization errors than older adult listeners with normal hearing. Also, results revealed a significant difference in performance between dome type; however, upon further examination was not

  9. Reliability of poroelastic equation in determination of minimum horizontal stress in sedimentary basins: implication of tectonic strain

    Science.gov (United States)

    Vo, Uy; Chang, Chandong

    2017-04-01

    Minimum horizontal stress (Shmin) magnitude, normally one of the three principal stresses, provides vital information in various stages of petroleum development such as hydraulic fracture design, wellbore stability analysis, and sand production prediction. Mini-frac or leak-off tests (LOT) are considered to be the technique used to measure Shmin magnitudes directly in the formation. Still, other than being time-consuming and costly, LOT does not give a continuous Shminprofile. A conventional alternative is to use a linear poroelasticity equation derived based on the assumption of uniaxially strained basins, which provides minimum horizontal stress magnitude (Shmin) as a function of vertical stress, pore pressure and Poisson's ratio (ν). In this study, we inspect the reliability of poroelastic equation-based calculation by comparing measured data of Shmin, pore pressure with log-based minimum horizontal stress magnitude in 6 major sedimentary basins worldwide. For calculation of Shmin via the equation, we assume ν of 0.25 and Biot's constant of unity. The comparison shows that the predicted Shmin values generally underestimate the measured values by a range between 4% and as high as 29% depending on the regions. The wide variation of horizontal stress may imply unpredictable complications in the stress states in the sedimentary basins. Besides, we also collect the data of maximum horizontal stress magnitudes and Young's modulus to estimate local tectonic strains, which are responsible for additional stresses over the induced horizontal stresses. The result reveals that the tectonic strain magnitudes are not consistent with the difference between measured and calculated values in minimum horizontal stress. Our results suggest that rock mechanical property such as Young's modulus is a more dominant factor that controls tectonic stress.

  10. Geological-geotechnical investigation for large horizontal directional drilling

    Energy Technology Data Exchange (ETDEWEB)

    Martins, Pedro R.R.; Rocha, Ronaldo; Avesani Neto, Jose Orlando; Placido, Rafael R.; Ignatius, Scandar G.; Galli, Vicente Luiz [Instituto de Pesquisas Tecnologicas do Estado de Sao Paulo (IPT), Sao Paulo, SP (Brazil); Amaral, Claudio S. [Centro de Pesquisa Leopoldo A. Miguez de Melo (CENPES/PETROBRAS), Rio de Janeiro, RJ (Brazil)

    2009-07-01

    Use of Horizontal Directional Drilling - HDD for large diameter (OD>20 inches) pipeline installation started in the second half of the seventies. Since then the method became the preferred alternative for situations in which it is necessary an underground pipeline but there are concerns about digging trenches. Crossings of roadways, water bodies and environmental sensitive areas are typical examples of its application. Technical and economic feasibility of HDD depends significantly on the properties of the materials that will be drilled. Lack of information about these materials can lead to several problems as: schedule delays, cost elevation, pipeline damage, unforeseen environmental impacts and even the failure of the entire operation. Ground investigation campaigns for HDD should define a consistent geological-geotechnical model, which must include determination of behaviour parameters for soil and rock masses that will be drilled. Thus it is proposed an investigation in tree stages: review of available geological-geotechnical information, site reconnaissance, and field survey. (author)

  11. Horizonte

    OpenAIRE

    BABIANO MARTÍNEZ, CARLOS JOSÉ

    2015-01-01

    Este proyecto intenta ahondar en la idea de horizonte tratado desde la filosofía japonesa y de su nexo con el mundo occidental. De la necesidad latente de una restructuración de la educación para convertirla en una educación estética capaz de permitir a los individuos completarse plenamente como personas. A través de las enseñanzas orientales del zen, del haiku, de filósofos como Tanizaki, y sus ideas sobre la sombra y la sugerencia, frente a Kierkegaard o Schiller en el lado occidental y sus...

  12. Effects of horizontal console position on operator muscular stress during abdominal ultrasonic diagnosis.

    Science.gov (United States)

    Suzuki, Hiroyuki; Saito, Takayoshi; Shimomura, Yoshihiro; Katsuura, Tetsuo

    2014-04-01

    Ultrasound examinations may require sonographers to adopt unnatural postures, which can lead to musculoskeletal disorders. We previously assessed the effect of a vertical operation panel on muscular stress. In this study, we focused on the horizontal positioning of the control panel of a diagnostic ultrasound system to quantitatively assess the influence of work plane position on musculoskeletal stress during scanning. Five subjects were asked to perform a simulated scanning task that involved touching five points on the control panel, with the work plane set at different positions in space. Electromyograms of each part of the body and wrist joint angles indicated that the least stressful position of the left hand was about 350 mm from the center of the trunk in the longitudinal (front-back) direction and 100 mm left of the center of the trunk in the lateral (right-left) direction.

  13. Effects of horizontal console position on operator muscular stress during cardiac ultrasonic diagnosis.

    Science.gov (United States)

    Suzuki, Hiroyuki; Saito, Takayoshi; Shimomura, Yoshihiro; Katsuura, Tetsuo

    2015-10-01

    Ultrasound examinations tend to put sonographers in unnatural postures, which may lead to musculoskeletal disorders. In order to address this issue, in this study, we focused on the horizontal position of the console of a diagnostic ultrasound system to quantitatively assess the influence of the work plane position on musculoskeletal stress cardiac ultrasonic diagnosis in the bed-sitting position. Five subjects were asked to simulate a scanning task that involved touching five points on the console, setting the work plane at different positions in the space. Electromyogram of each part of the body indicated that the least stressful position of the left hand was about 350 mm from the center of the trunk in the longitudinal (front-rear) direction and 100 mm left from the center of the trunk in the lateral (left-right) direction. It is necessary to rotate the console in front of the operator for this purpose.

  14. Direct Numerical Simulation Sediment Transport in Horizontal Channel

    Energy Technology Data Exchange (ETDEWEB)

    Uhlmann, M.

    2006-07-01

    We numerically simulate turbulent flow in a horizontal plane channel over a bed of mobile particles. All scales of fluid motion are resolved without modeling and the phase interface is accurately represented. Our results indicate a possible scenario for the onset of erosion through collective motion induced by buffer-layer streaks. (Author) 27 refs.

  15. Crosswell Imaging Technology & Advanced DSR Navigation for Horizontal Directional Drilling

    Energy Technology Data Exchange (ETDEWEB)

    Larry Stolarczyk

    2008-08-08

    The objective of Phase II is to develop and demonstrate real-time measurement-while-drilling (MWD) for guidance and navigation of drill strings during horizontal drilling operations applicable to both short and long holes. The end product of Phase II is a functional drill-string assembly outfitted with a commercial version of Drill String Radar (DSR). Project Objectives Develop and demonstrate a dual-phase methodology of in-seam drilling, imaging, and structure confirmation. This methodology, illustrated in Figure 1, includes: (1) Using RIM to image between drill holes for seam thickness estimates and in-seam structures detection. Completed, February 2005; and (2) Using DSR for real-time MWD guidance and navigation of drillstrings during horizontal drilling operations. Completed, November 2008. As of November 2008, the Phase II portion of Contract DE-FC26-04NT42085 is about 99% complete, including milestones and tasks original outlined as Phase II work. The one percent deficiency results from MSHA-related approvals which have yet to be granted (at the time of reporting). These approvals are pending and are do not negatively impact the scope of work or project objectives.

  16. Stress and nurses' horizontal mobbing: moderating effects of group identity and group support.

    Science.gov (United States)

    Topa, Gabriela; Moriano, Juan A

    2013-01-01

    Horizontal mobbing is a process of systematic and repeated aggression towards a worker by coworkers. Among others, stress has been pointed out as one of the antecedents that favors the onset of horizontal mobbing, whereas group support to the target could act as a buffer. Moreover, the social identity approach emphasizes that group identity is an antecedent of group support. This study explores the interaction of group support and group identity in the explanation of horizontal mobbing in a sample (N = 388) of registered nurses and licensed practical nurses employed at two large hospitals in Madrid and Navarre (Spain). The results show that stress is positively associated to horizontal mobbing, whereas group support and group identity were negative predictors of horizontal mobbing. Furthermore, the combination of low group identity and low group support precipitated HM among nurses. Copyright © 2013 Elsevier Inc. All rights reserved.

  17. Horizontal principal stress orientation in the Costa Rica Seismogenesis Project (CRISP) transect from borehole breakouts

    Science.gov (United States)

    Malinverno, A.; Saito, S.; Vannucchi, P.

    2016-01-01

    The Costa Rica Seismogenesis Project (CRISP) drilled the Pacific margin of the Middle America Trench just north of where the Cocos Ridge enters the subduction zone, resulting in basal erosion of the upper plate. Here we report the orientations of the maximum horizontal principal stress (SHmax) from borehole breakouts detected by logging-while-drilling and wireline downhole measurements. All SHmax directions were estimated in the sediment cover of the margin, above the deeper rocks of the deformed margin wedge. We observe three overall SHmax orientations: NNE-SSW (25° azimuth) in the deepest interval drilled at the upper slope Site U1379; ENE-WSW (82°) in the rest of Site U1379 and in Site U1413, also drilled in the upper slope; and NNW-SSE (157°) in the mid-slope Site U1378. Our preferred interpretation is that the deepest interval of Site U1379 records the stress conditions in the underlying margin wedge, as SHmax is parallel to the direction of the Cocos-Caribbean plate convergence and of the compressional axes of plate boundary fault earthquakes. The variable SHmax directions observed elsewhere are likely due to the effect of a network of normal faults that subdivide the sediment cover into a number of independently deforming blocks. In addition, the observed SHmax directions may be influenced by the subducting Cocos Ridge, which acts as an indenter causing oblique deformation, and by the transition to seismogenic subduction along the plate boundary fault.

  18. Methodology for definition of bending radius and pullback force in HDD (Horizontal Directional Drilling) operations

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Danilo Machado L. da; Rodrigues, Marcos V. [Det Norske Veritas (DNV), Rio de Janeiro, RJ (Brazil); Venaas, Asle [Det Norske Veritas (DNV), Oslo (Norway); Medeiros, Antonio Roberto de [Subsea 7 (Brazil)

    2009-12-19

    Bending is a primary loading experienced by pipelines during installation and operation. Significant bending in the presence of tension is experienced during installation by the S-lay method, as the pipe conforms to the curvature of the stinger and beyond in the over bend region. Bending in the presence of external pressure is experienced in the sag bend of all major installation methods (e.g., reeling, J-lay, S-lay) as well as in free-spans on the sea floor. Bending is also experienced by pipelines during installation by horizontal directional drilling. HDD procedures are increasingly being utilized around the world not only for crossings of rivers and other obstacles but also for shore approach of offshore pipelines. During installation the pipeline experience a combination of tensile, bending, and compressive stresses. The magnitude of these stresses is a function of the approach angle, bending radius, pipe diameter, length of the borehole, and the soil properties at the site. The objective of this paper is to present an overview of some aspects related to bending of the product pipe during HDD operations, which is closely related to the borehole path as the pipeline conforms to the curvature of the hole. An overview of the aspects related to tensile forces is also presented. The combined effect of bending and tensile forces during the pullback operation is discussed. (author)

  19. On the use of horizontal acoustic doppler profilers for continuous bed shear stress monitoring

    NARCIS (Netherlands)

    Vermeulen, B.; Hoitink, A.J.F.; Sassi, M.G.

    2013-01-01

    Continuous monitoring of bed shear stress in large river systems may serve to better estimate alluvial sediment transport to the coastal ocean. Here we explore the possibility of using a horizontally deployed acoustic Doppler current profiler (ADCP) to monitor bed shear stress, applying a prescribed

  20. Process analysis and optimization of direct horizontal-row roughing filtration

    NARCIS (Netherlands)

    Ahsan, T.

    1995-01-01

    There is a growing demand for appropriate water treatment technology for towns and small cities in developing countries. This study developed a pretreatment technology for highly turbid river water, called direct horizontal-flow roughing filtration, by combining the principles of direct filtration

  1. Horizontal directional drilling: a green and sustainable technology for site remediation.

    Science.gov (United States)

    Lubrecht, Michael D

    2012-03-06

    Sustainability has become an important factor in the selection of remedies to clean up contaminated sites. Horizontal directional drilling (HDD) is a relatively new drilling technology that has been successfully adapted to site remediation. In addition to the benefits that HDD provides for the logistics of site cleanup, it also delivers sustainability advantages, compared to alternative construction methods.

  2. Static postural control with aging in a vertical direction and on a horizontal plane

    OpenAIRE

    Yumi, Asano; Ichiro, Shimoyama; Atsushi, Murata

    2009-01-01

    Postural control in standing balance was analyzed in 80 volunteers, aged 31 to 92 years, who were free from equilibrium disease. Center of foot pressure (COP) was measured on a horizontal plane and in a vertical direction, during 20 sec with eyes open and 20 sec with eyes closed. COP-path length and COP-path area were obtained on the horizontal plane, and coefficient of correlation was tested for them with age, body weight and height. Integrated power between 0 and 10 Hz was tested for the ho...

  3. Rivulet flow round a horizontal cylinder subject to a uniform surface shear stress

    KAUST Repository

    Paterson, C.

    2014-09-14

    © 2014 © The Author, 2014. Published by Oxford University Press; all rights reserved. For Permissions, please email: journals.permissions@oup.com. The steady flow of a slowly varying rivulet with prescribed flux in the azimuthal direction round a large stationary horizontal cylinder subject to a prescribed uniform azimuthal surface shear stress is investigated. In particular, we focus on the case where the volume flux is downwards but the shear stress is upwards, for which there is always a solution corresponding to a rivulet flowing down at least part of one side of the cylinder. We consider both a rivulet with constant non-zero contact angle but slowly varying width (that is, de-pinned contact lines) and a rivulet with constant width but slowly varying contact angle (that is, pinned contact lines), and show that they have qualitatively different behaviour. When shear is present, a rivulet with constant non-zero contact angle can never run all the way from the top to the bottom of the cylinder, and so we consider the scenario in which an infinitely wide two-dimensional film of uniform thickness covers part of the upper half of the cylinder and \\'breaks\\' into a single rivulet with constant non-zero contact angle. In contrast, a sufficiently narrow rivulet with constant width can run all the way from the top to the bottom of the cylinder, whereas a wide rivulet can do so only if its contact lines de-pin, and so we consider the scenario in which the contact lines of a wide rivulet de-pin on the lower half of the cylinder.

  4. Environmental Measurement-While-Drilling System and Horizontal Directional Drilling Technology Demonstration, Hanford Site

    Energy Technology Data Exchange (ETDEWEB)

    Williams, C.V.; Lockwood, G.J.; Normann, R.A.; Myers, D.A.; Gardner, M.G.; Williamson, T.; Huffman, J.

    1999-06-01

    The Environmental Measurement-While-Drilling (EMWD) system and Horizontal Directional Drilling (HDD) were successfully demonstrated at the Mock Tank Leak Simulation Site and the Drilling Technology Test Site, Hanford, Washington. The use of directional drilling offers an alternative to vertical drilling site characterization. Directional drilling can develop a borehole under a structure, such as a waste tank, from an angled entry and leveling off to horizontal at the desired depth. The EMWD system represents an innovative blend of new and existing technology that provides the capability of producing real-time environmental and drill bit data during drilling operations. The technology demonstration consisted of the development of one borehole under a mock waste tank at a depth of {approximately} {minus}8 m ({minus}27 ft.), following a predetermined drill path, tracking the drill path to within a radius of {approximately}1.5 m (5 ft.), and monitoring for zones of radiological activity using the EMWD system. The purpose of the second borehole was to demonstrate the capability of drilling to a depth of {approximately} {minus}21 m ({minus}70 ft.), the depth needed to obtain access under the Hanford waste tanks, and continue drilling horizontally. This report presents information on the HDD and EMWD technologies, demonstration design, results of the demonstrations, and lessons learned.

  5. Horizontal directional drilling method for pipeline installation and rehabilitation; Aplicacao de perfuracao direcional horizontal na implantacao e reabilitacao da malha dutoviaria

    Energy Technology Data Exchange (ETDEWEB)

    Pimenta, Carlos Fugazzola; Miura, Kazumi; Jardim, Eduardo de A.P. [Intech Engenharia Ltda., Rio de Janeiro, RJ (BRazil)

    2003-07-01

    In order to modernize Brazilian pipelines, built among the last decades, PETROBRAS has been executing coating repair services, substituting sections internally and externally corroded and also replacing aerial pipelines by buried pipelines. For the execution of such jobs, the Horizontal Directional Drilling method has been largely used for reasons such difficult of access, environmental preservation and quick execution. The present abstract relates Intech Engenharia Ltda and HDI - Horizontal Drilling International S.A. experience during the replacement of seven aerial pipelines for buried pipelines, connecting REDUC (Duque de Caxias Refinery) to TEDUC (Duque de Caxias Distribution Tanks Terminal) in the city of Duque de Caxias, State of Rio de Janeiro. (author)

  6. Performance of a Direct Horizontal Roughing Filtration (DHRF System in Treatment of Highly Turbid Water

    Directory of Open Access Journals (Sweden)

    A H Mahvi, M Ahmadi Moghaddam, S Nasseri, K Naddafi

    2004-07-01

    Full Text Available Vertical or horizontal flow gravel beds can be used in water treatment as roughing filters. In order to improve the performance of horizontal flow roughing filtration (HRF this process has been modified earlier by applying a constant coagulant dose prior to filtration named direct horizontal roughing filtration (DHRF. In this research a lab scale DHRF pilot plant was used for investigate DHRF performance. The study results indicated that DHRF (6.5 m long consisting of 2.5 m first compartment with 12-18 mm diameter grain, 2 m/s compartment with 8-12 mm diameter and 1.5m third compartment with 4-8 mm diameter was systematically yielded good effluent quality (<2NTU, C.I=0.95 with raw water quality of 200-400 NTU. DHRF is a versatile pretreatment process capable of handling wide fluctuation in raw water turbidity (200-400 NTU while operating condition such as coagulant dose [2mg Fe (III/L], mixing intensity, time and filtration rate remained unchangeable.

  7. Modeling of particle removal in the first coarse media of direct horizontal-flow roughing filtration.

    Science.gov (United States)

    Ahn, H W; Park, N S; Kim, S; Park, S Y; Wang, C K

    2007-03-01

    Horizontal-Flow Roughing Filtration (HRF) is an alternative pretreatment method e.g. prior to Slow Sand Filtration (SSF). However, some of its limitations are that the effluent quality drops drastically at higher turbidity (>200NTU) and at higher filtration rate (>1 m h(-1)). To overcome these drawbacks, we suggested Direct Horizontal-Flow Roughing Filtration (DHRF), which is a modified system of Horizontal-Flow Roughing Filtration (HRF) by addition of a low dose of coagulant prior to filtration. To optimize the DHRF configuration, a conceptual and mathematical model for the coarse compartment has been developed in analogy with multi-plate settler. Data from simple column settling test can be used in the model to predict the filter performance. Furthermore, the model developed herein has been validated by successive experiments. The conventional column settling test has been found to be handy and useful to predict the performance of DHRF for different raw water characteristics (e.g. coagulated or uncoagulated water, different amounts of organic matter, etc.) and different initial process conditions (e.g. coagulant dose, mixing time and intensity, etc.). An optimum filter design for the coarse compartment (grain size 20 mm) has been found to be of 3m h(-1) filtration rate with filter length of 4-4.5 m.

  8. Study of a pipe-scanning robot for use in post-construction evaluation during horizontal directional drilling.

    Science.gov (United States)

    2015-06-01

    Trenchless Technology has become an increasingly popular underground utility construction method, beginning in : the early 1900s with pipe jacking beneath railroad lines. One method, horizontal directional drilling (HDD), became : more common in the ...

  9. Survey of horizontal stresses in coal mines from available measurements and mapping.

    CSIR Research Space (South Africa)

    Frith, R

    2002-09-01

    Full Text Available _______________________________________________________________________________ ___ STRATA ENGINEERING (Australia) Pty Ltd 3 A detailed description of the project outcomes will now be given. SIMRAC: Final Report, Project COL802 (Horizontal Stress Survey) 27th September 2002... of Inertia (m4) e = eccentricity (m) u = lateral displacement of buckling beam (m) l = beam length (m) 0 1 2 3 4 5 6 7 0 5 10 15 20 25 30 35 40 45 50 Displacement (mm) He ig ht in to R oo f ( m ) SIMRAC: Final Report, Project COL802...

  10. Directionally dependent horizontal-to-vertical spectral ratios of microtremors at Onahama, Fukushima, Japan

    Science.gov (United States)

    Matsushima, Shinichi; Kosaka, Hiroyuki; Kawase, Hiroshi

    2017-07-01

    As observational evidence of 3-D microtremor horizontal-to-vertical spectral ratios (MHVRs), previous studies have shown that a significant directional dependency is observed in and around Uji campus, Kyoto University, Japan. This directional dependence is considered to be the result of 2-D basin structure. In this study, we observed microtremors around a strong motion observation site of the Port and Harbor Research Institute in Onahama, Japan, and found that directional dependence of MHVRs exists in some parts of the area around the site. The directional dependence is more apparent and has a higher dominant frequency, at around 5 Hz, relative to those observed in Uji, at around 0.5 Hz. We defined a parameter γ, which we refer to as the "directionally dependent coefficient" to indicate the magnitude of difference between the two orthogonal components which implies the directional dependence of the MHVRs. We rotated the axes and calculated γ for each angle and searched for the orientation that gave the largest γ at a point. Points for which the axis with larger MHVR amplitude among the two axes is oriented in the NS direction are aligned in the NS direction, while points for which the axis with larger MHVR amplitude is oriented in the EW direction are aligned in the EW direction. The distribution of points with large γ formed a T-shaped distribution. We calculated the analytical and numerical MHVRs in order to simulate the observed MHVRs and succeeded in showing the existence of a narrow wedge. From these results, we conclude that a wedge-like lateral heterogeneity exists in the shallow subsurface of the studied area, parallel to the direction of the axis of the larger MHVR amplitude.

  11. Sprinting, Change of Direction Ability and Horizontal Jump Performance in Youth Runners According to Gender

    Directory of Open Access Journals (Sweden)

    Yanci Javier

    2017-12-01

    Full Text Available The purpose of the study was to assess straight sprinting, change of direction ability and horizontal jump performance in youth runners according to age and gender. Two hundred and fifty-five youth runners (116 boys and 139 girls participated in this study. The athletes were divided according to their age into five groups: under 8 yr (U8, under 10 yr (U10, under 12 yr (U12, under 14 yr (U14 and under 16 yr (U16. Significant differences (p 0.05, d = 0.29-1.17 between U14 and U16 were observed in any of the tests. With regard to age and gender, in U8 and U10 groups there were no significant differences (p > 0.05, d = 0.02-0.76 between boys and girls in any test. However, in U12 and U14 groups, significant gender differences (p < 0.05, d = 0.85-1.24 were found in the MAT. Likewise, the boys obtained better results than girls in the horizontal jump tests (p < 0.05, d = 1.01-1.26. After the classification by age, some differences were observed between both genders, depending on the fitness variable evaluated.

  12. Horizontal environmental assessment of building products in relation to the construction products directive (CPD).

    Science.gov (United States)

    Schiopu, Nicoleta; Jayr, Emmanuel; Méhu, Jacques; Barna, Ligia; Moszkowicz, Pierre

    2007-01-01

    According to the European Construction Products Directive (89/106/EC), construction products must satisfy specified essential requirements (ER). To comply with ER 3, on hygiene, health and environment, the construction works must be designed and built in such a way that they will not be a threat to the hygiene and health of the occupants and neighbours, nor to the environment. Standardised test methods for the release of substances that are hazardous to health and environment need to be developed at the European level. A horizontal approach is considered the best route for such test development and consists of the development of a test method applicable for different products used in a certain scenario (across the fields of different Technical Committees). The work presented here regards the emission of pollutants towards soil and water and has been carried out on monolith products, based on three types of matrices: concrete, wood and metal (zinc). The aim of the work is to study the parameters (nature of leachant, temperature, liquid-to-solid ratio) that could influence the release behaviour of substances in water. The knowledge acquired from these tests will allow the identification of some parameters needed for the development of a horizontal test.

  13. A numerical study of the direct contact condensation on a horizontal surface

    Science.gov (United States)

    Hasan, M. M.; Lin, C. S.

    1991-01-01

    The results of a numerical study of the direct contact condensation on a slowly moving horizontal liquid surface are presented. The geometrical configuration and the input conditions used to obtain numerical solutions are representative to those of experiments of Celata et al. The effects of Prandtl number (Pr), inflow Reynolds number, and Richardson number on the condensation rate are investigated. Numerical predictions of condensation rate for laminar flow are in good agreement with experimental data. The effect of buoyancy on the condensation rate is characterized by Richardson number. A correlation based on the numerical solutions is developed to predict the average condensation Nusselt number in terms of Richardson number, Peclet number, and inflow Reynolds number.

  14. Intercomparison of 51 radiometers for determining global horizontal irradiance and direct normal irradiance measurements

    Energy Technology Data Exchange (ETDEWEB)

    Habte, Aron; Sengupta, Manajit; Andreas, Afshin; Wilcox, Stephen; Stoffel, Thomas

    2016-08-01

    Accurate solar radiation measurements require properly installed and maintained radiometers with calibrations traceable to the World Radiometric Reference. This study analyzes the performance of 51 commercially available and prototype radiometers used for measuring global horizontal irradiances or direct normal irradiances. These include pyranometers, pyrheliometers, rotating shadowband radiometers, and a pyranometer with an internal shading mask deployed at the National Renewable Energy Laboratory's (NREL) Solar Radiation Research Laboratory. The radiometers in this study were deployed for one year (from April 1, 2011, through March 31, 2012), and their measurements were compared under clear-sky, partly cloudy, and mostly cloudy conditions to reference values of low estimated measurement uncertainties. The intent of this paper is to present a general overview of each radiometer's performance based on the instrumentation and environmental conditions available at NREL.

  15. Macrosegregation in horizontal direct chill casting of ternary Al alloys: Investigation of solid motion

    Science.gov (United States)

    Vušanović, I.; Krane, M. J. M.

    2012-01-01

    Macrosegregation in direct chill casting processes is controlled by fluid flow due to the thermosolutal natural and forced convection, shrinkage, and transport of unattached solid grains. Because grain refinement is usually used in aluminum direct chill casting, some effort must be made to model free-floating solid grains, and their attachment to a rigid mushy zone. Criteria for attachment vary, but many are based on using a critical solid packing fraction, which is treated as uniform and constant throughout the domain. In the case of horizontal casting (HDC), gravity acts perpendicularly to the casting direction, and the assumption of a uniform packing fraction cannot be applied because the solid particles attach to some surfaces by settling and others by being swept into the rigid solid from below. In this simulation of HDC casting of an Al-Cu-Mg alloy, the rigid and unattached solid is tracked separately, and a rule set is developed to determine the attachment of free-floating solid. Comparison between cases with and without unattached solid movement shows qualitatively different results, particularly in bottom part of slab. Non-uniform packing fractions cause very different segregation patterns in the lower half of the ingot compared to the cases with no solid movement, less segregation near centerline compared to uniform packing fraction cases, and positive segregation near the place where inlet jet impinges on the mushy zone.

  16. Horizontal Directional Drilling-Length Detection Technology While Drilling Based on Bi-Electro-Magnetic Sensing

    Science.gov (United States)

    Wang, Yudan; Wen, Guojun; Chen, Han

    2017-01-01

    The drilling length is an important parameter in the process of horizontal directional drilling (HDD) exploration and recovery, but there has been a lack of accurate, automatically obtained statistics regarding this parameter. Herein, a technique for real-time HDD length detection and a management system based on the electromagnetic detection method with a microprocessor and two magnetoresistive sensors employing the software LabVIEW are proposed. The basic principle is to detect the change in the magnetic-field strength near a current coil while the drill stem and drill-stem joint successively pass through the current coil forward or backward. The detection system consists of a hardware subsystem and a software subsystem. The hardware subsystem employs a single-chip microprocessor as the main controller. A current coil is installed in front of the clamping unit, and two magneto resistive sensors are installed on the sides of the coil symmetrically and perpendicular to the direction of movement of the drill pipe. Their responses are used to judge whether the drill-stem joint is passing through the clamping unit; then, the order of their responses is used to judge the movement direction. The software subsystem is composed of a visual software running on the host computer and a software running in the slave microprocessor. The host-computer software processes, displays, and saves the drilling-length data, whereas the slave microprocessor software operates the hardware system. A combined test demonstrated the feasibility of the entire drilling-length detection system. PMID:28448445

  17. Horizontal Directional Drilling-Length Detection Technology While Drilling Based on Bi-Electro-Magnetic Sensing.

    Science.gov (United States)

    Wang, Yudan; Wen, Guojun; Chen, Han

    2017-04-27

    The drilling length is an important parameter in the process of horizontal directional drilling (HDD) exploration and recovery, but there has been a lack of accurate, automatically obtained statistics regarding this parameter. Herein, a technique for real-time HDD length detection and a management system based on the electromagnetic detection method with a microprocessor and two magnetoresistive sensors employing the software LabVIEW are proposed. The basic principle is to detect the change in the magnetic-field strength near a current coil while the drill stem and drill-stem joint successively pass through the current coil forward or backward. The detection system consists of a hardware subsystem and a software subsystem. The hardware subsystem employs a single-chip microprocessor as the main controller. A current coil is installed in front of the clamping unit, and two magneto resistive sensors are installed on the sides of the coil symmetrically and perpendicular to the direction of movement of the drill pipe. Their responses are used to judge whether the drill-stem joint is passing through the clamping unit; then, the order of their responses is used to judge the movement direction. The software subsystem is composed of a visual software running on the host computer and a software running in the slave microprocessor. The host-computer software processes, displays, and saves the drilling-length data, whereas the slave microprocessor software operates the hardware system. A combined test demonstrated the feasibility of the entire drilling-length detection system.

  18. Exploring direct 3D interaction for full horizontal parallax light field displays using leap motion controller.

    Science.gov (United States)

    Adhikarla, Vamsi Kiran; Sodnik, Jaka; Szolgay, Peter; Jakus, Grega

    2015-04-14

    This paper reports on the design and evaluation of direct 3D gesture interaction with a full horizontal parallax light field display. A light field display defines a visual scene using directional light beams emitted from multiple light sources as if they are emitted from scene points. Each scene point is rendered individually resulting in more realistic and accurate 3D visualization compared to other 3D displaying technologies. We propose an interaction setup combining the visualization of objects within the Field Of View (FOV) of a light field display and their selection through freehand gesture tracked by the Leap Motion Controller. The accuracy and usefulness of the proposed interaction setup was also evaluated in a user study with test subjects. The results of the study revealed high user preference for free hand interaction with light field display as well as relatively low cognitive demand of this technique. Further, our results also revealed some limitations and adjustments of the proposed setup to be addressed in future work.

  19. Project for Offshore Horizontal Directional Drilling (HDD for Pipeline Crossing in Bukit Tua, Indonesia

    Directory of Open Access Journals (Sweden)

    Yusuf Sofyan

    2016-09-01

    Full Text Available Horizontal Directional Drilling (HDD is commonly associated with well exploration activity, onshore road crossing, nearshore pipeline installation, and offshore pipeline crossing which requires precise alignment of two barges from one to the other. Here, the purpose of this study was to show one of the projects that was successfully performed on December 2013 for the Bukit Tua Project in East Java, Indonesia costing USD 8 Million. From this project experience, there are 6 Best Practices in HDD Offshore Project for Pipeline Crossing Application (first in region which will serve as a guide to future projects in replicating similar success. Out from 6 Best practices, there are two main recipes for success of HDD offshore for offshore crossings which are the drilling fluid also known as mud, and the Gyro Steering Tool (GST. First, mud parameter varies on case by case basis depending on the soil condition at the location where HDD will be performed. Failure to maintain the above parameters may result in catastrophic failure whereby the bore hole may collapse and pipe may get stuck underneath the seabed. Secondly, the beauty of GST is extremely accurate and unaffected by other metal anomalies during drilling process, thus ensuring the curve profile and direction of drilling are as per design throughout the whole process.

  20. Exploring Direct 3D Interaction for Full Horizontal Parallax Light Field Displays Using Leap Motion Controller

    Directory of Open Access Journals (Sweden)

    Vamsi Kiran Adhikarla

    2015-04-01

    Full Text Available This paper reports on the design and evaluation of direct 3D gesture interaction with a full horizontal parallax light field display. A light field display defines a visual scene using directional light beams emitted from multiple light sources as if they are emitted from scene points. Each scene point is rendered individually resulting in more realistic and accurate 3D visualization compared to other 3D displaying technologies. We propose an interaction setup combining the visualization of objects within the Field Of View (FOV of a light field display and their selection through freehand gesture tracked by the Leap Motion Controller. The accuracy and usefulness of the proposed interaction setup was also evaluated in a user study with test subjects. The results of the study revealed high user preference for free hand interaction with light field display as well as relatively low cognitive demand of this technique. Further, our results also revealed some limitations and adjustments of the proposed setup to be addressed in future work.

  1. Towards quantifying horizontal stresses of free-polling pneumatic rubber tyres on road surfaces

    CSIR Research Space (South Africa)

    De Beer, Morris

    2008-07-01

    Full Text Available Multi-dimensional forces (and stresses) inside the contact patch of a freerolling pneumatic rubber tyre generally occur as a direct result of a complex interaction between flexible rubber and a rigid test surface or road surface. These forces...

  2. Horizontal Directional Drilling-Length Detection Technology While Drilling Based on Bi-Electro-Magnetic Sensing

    Directory of Open Access Journals (Sweden)

    Yudan Wang

    2017-04-01

    Full Text Available The drilling length is an important parameter in the process of horizontal directional drilling (HDD exploration and recovery, but there has been a lack of accurate, automatically obtained statistics regarding this parameter. Herein, a technique for real-time HDD length detection and a management system based on the electromagnetic detection method with a microprocessor and two magnetoresistive sensors employing the software LabVIEW are proposed. The basic principle is to detect the change in the magnetic-field strength near a current coil while the drill stem and drill-stem joint successively pass through the current coil forward or backward. The detection system consists of a hardware subsystem and a software subsystem. The hardware subsystem employs a single-chip microprocessor as the main controller. A current coil is installed in front of the clamping unit, and two magneto resistive sensors are installed on the sides of the coil symmetrically and perpendicular to the direction of movement of the drill pipe. Their responses are used to judge whether the drill-stem joint is passing through the clamping unit; then, the order of their responses is used to judge the movement direction. The software subsystem is composed of a visual software running on the host computer and a software running in the slave microprocessor. The host-computer software processes, displays, and saves the drilling-length data, whereas the slave microprocessor software operates the hardware system. A combined test demonstrated the feasibility of the entire drilling-length detection system.

  3. Work ability and stress in a bus transportation company in Belo Horizonte, Brazil.

    Science.gov (United States)

    Sampaio, Rosana Ferreira; Coelho, Cecília Martins; Barbosa, Fábio Bonfim; Mancini, Marisa Cotta; Parreira, Verônica Franco

    2009-01-01

    Demographic, occupational and psychosocial characteristics affect the health and occupational performance of workers. The objective of the present study was to elaborate a profile of the work ability and factors that affect it in a bus transportation company in Belo Horizonte, Brazil. The instruments used included a socio-demographic and occupational questionnaire, the Work Ability Index and the Job Stress Scale. Demographic information revealed that 85.7% of the 126 employees of the company were active workers, 98% were males, with an average of 39 years of age (SD= 10) and 79 months working in the company (SD= 68); more than half reported having a low schooling level. In terms of personal habits, 88% were exposed to one or more risk factors, especially a sedentary lifestyle. The average strain value (as a consequence of stress) was 0.78 (SD= 0.2) and 75.3% reported episodes of violence at the workplace. The work ability was good to excellent among 89% of the workers. Results from the logistic regression analysis showed that strain was the only significant variable in relation to the Work Ability Index, (estimated odds ratio of 0.02). The results suggest that psychosocial factors presented the greatest association with work ability, and preventive and/or corrective measures should be implemented.

  4. Literature review of the benefits and obstacle of horizontal directional drilling

    Science.gov (United States)

    Norizam, M. S. Mohd; Nuzul Azam, H.; Helmi Zulhaidi, S.; Aziz, A. Abdul; Nadzrol Fadzilah, A.

    2017-11-01

    In this new era the construction industry not only need to be completed within budget, timely, at acceptable quality and safety but the stakeholders especially the local authorities and the public realises for the important need of sustainable construction method to be used for our younger generation to heritage if not better a safer world for them to live and raise up their children’s. Horizontal Directional Drilling method is the most commonly recognised trenchless utilities method as a preferred construction method in this age. Among the reasons HDD method offers less disturbance on traffic, the public, business activities and neighbourhood, lower restoration cost, less noise, dust and minimum import/export of the construction materials. In addition HDD method can drill through congested utilities areas with minimum cutting and shorter time. This paper aims to appraise the benefits and obstacle of HDD method in construction industry. It is an endeavour to fulfil the local authorities cry for alternative method that less damages to the roads, road furniture’s and public complaints compared to the conventional open cut method. In addition HDD method is seem to be in line with sustainable development requirements e.g. reduce, reuse, recycle and etc. Hence, it is important to determine the benefits and obstacle factors of HDD implementation. The factors are based on the literature review conducted by the author on the subject matters gathered from previous studies, journals, text books, guidelines, magazine articles, newspaper cutting and etc.

  5. Stress distribution in maxillary first molar periodontium using straight pull headgear with vertical and horizontal tubes: A finite element analysis

    Directory of Open Access Journals (Sweden)

    Masood Feizbakhsh

    2017-01-01

    Conclusion: Based on the results, when force applied to the straight pull headgear with a vertical tube, Von Mises stress was reduced significantly in comparison with the horizontal tube. Therefore, to correct the mesiolingual movement of the maxillary first molar, vertical headgear tube is recommended.

  6. Nieuwe boortechnieken kleine infra : Modelling the soil pipeline interaction during the pull back operation of horizontal directional drilling

    NARCIS (Netherlands)

    Pruiksma, J.P.; Kruse, H.M.G.

    2009-01-01

    The pull back operation is the most important stage of horizontal directional drilling (HDD). The cost of jammed pipelines, damaged pipelines and the costs for additional measures during and after the pull back operation can be considerable. Recently in the Netherlands several problems occurred

  7. Stress distribution in maxillary first molar periodontium using straight pull headgear with vertical and horizontal tubes: A finite element analysis.

    Science.gov (United States)

    Feizbakhsh, Masood; Kadkhodaei, Mahmoud; Zandian, Dana; Hosseinpour, Zahra

    2017-01-01

    One of the most effective ways for distal movement of molars to treat Class II malocclusion is using extraoral force through a headgear device. The purpose of this study was the comparison of stress distribution in maxillary first molar periodontium using straight pull headgear in vertical and horizontal tubes through finite element method. Based on the real geometry model, a basic model of the first molar and maxillary bone was obtained using three-dimensional imaging of the skull. After the geometric modeling of periodontium components through CATIA software and the definition of mechanical properties and element classification, a force of 150 g for each headgear was defined in ABAQUS software. Consequently, Von Mises and Principal stresses were evaluated. The statistical analysis was performed using T-paired and Wilcoxon nonparametric tests. Extension of areas with Von Mises and Principal stresses utilizing straight pull headgear with a vertical tube was not different from that of using a horizontal tube, but the numerical value of the Von Mises stress in the vertical tube was significantly reduced ( P 0/05). Based on the results, when force applied to the straight pull headgear with a vertical tube, Von Mises stress was reduced significantly in comparison with the horizontal tube. Therefore, to correct the mesiolingual movement of the maxillary first molar, vertical headgear tube is recommended.

  8. Variation in community structure across vertical intertidal stress gradients: how does it compare with horizontal variation at different scales?

    Directory of Open Access Journals (Sweden)

    Nelson Valdivia

    Full Text Available In rocky intertidal habitats, the pronounced increase in environmental stress from low to high elevations greatly affects community structure, that is, the combined measure of species identity and their relative abundance. Recent studies have shown that ecological variation also occurs along the coastline at a variety of spatial scales. Little is known, however, on how vertical variation compares with horizontal variation measured at increasing spatial scales (in terms of sampling interval. Because broad-scale processes can generate geographical patterns in community structure, we tested the hypothesis that vertical ecological variation is higher than fine-scale horizontal variation but lower than broad-scale horizontal variation. To test this prediction, we compared the variation in community structure across intertidal elevations on rocky shores of Helgoland Island with independent estimates of horizontal variation measured at the scale of patches (quadrats separated by 10s of cm, sites (quadrats separated by a few m, and shores (quadrats separated by 100s to 1000s of m. The multivariate analyses done on community structure supported our prediction. Specifically, vertical variation was significantly higher than patch- and site-scale horizontal variation but lower than shore-scale horizontal variation. Similar patterns were found for the variation in abundance of foundation taxa such as Fucus spp. and Mastocarpus stellatus, suggesting that the effects of these canopy-forming algae, known to function as ecosystem engineers, may explain part of the observed variability in community structure. Our findings suggest that broad-scale processes affecting species performance increase ecological variability relative to the pervasive fine-scale patchiness already described for marine coasts and the well known variation caused by vertical stress gradients. Our results also indicate that experimental research aiming to understand community structure on

  9. Behavior of the reflection function of a plane-parallel medium for directions of incidence and reflection tending to horizontal directions

    OpenAIRE

    Stam, J. W. Hovenier D. M.

    2008-01-01

    The atmospheres of (exo) planets and moons, as well as reflection nebulae, contain in general independently scattering particles in random orientation and are often supposed to be plane-parallel. Relations are presented for the (bidirectional) reflection function and several related functions of such a medium in case the directions of incidence and reflection both tend to horizontal directions. The results are quite general. The medium may be semi-infinite or finite, with or without a reflect...

  10. Stress distribution in maxillary first molar periodontium using straight pull headgear with vertical and horizontal tubes: A finite element analysis

    OpenAIRE

    Feizbakhsh, Masood; Kadkhodaei, Mahmoud; Zandian, Dana; Hosseinpour, Zahra

    2017-01-01

    Background: One of the most effective ways for distal movement of molars to treat Class II malocclusion is using extraoral force through a headgear device. The purpose of this study was the comparison of stress distribution in maxillary first molar periodontium using straight pull headgear in vertical and horizontal tubes through finite element method. Materials and Methods: Based on the real geometry model, a basic model of the first molar and maxillary bone was obtained using three-dimen...

  11. Mixed-order Ambisonics recording and playback for improving horizontal directionality

    DEFF Research Database (Denmark)

    Favrot, Sylvain Emmanuel; Marschall, Marton; Käsbach, Johannes

    2011-01-01

    Planar (2D) and periphonic (3D) higher-order Ambisonics (HOA) systems are widely used to reproduce spatial properties of acoustic scenarios. Mixed-order Ambisonics (MOA) systems combine the benet of higher order 2D systems, i.e. a high spatial resolution over a larger usable frequency bandwidth...... in the horizontal plane and the usable frequency bandwidth for playback as well as recording. Hence the described MOA scheme provides a promising method for improving the performance of current 3D sound reproduction systems....

  12. A directional model of tropospheric horizontal gradients in Global Positioning System and its application for particular weather scenarios

    Science.gov (United States)

    Masoumi, Salim; McClusky, Simon; Koulali, Achraf; Tregoning, Paul

    2017-04-01

    Improper modeling of horizontal tropospheric gradients in GPS analysis induces errors in estimated parameters, with the largest impact on heights and tropospheric zenith delays. The conventional two-axis tilted plane model of horizontal gradients fails to provide an accurate representation of tropospheric gradients under weather conditions with asymmetric horizontal changes of refractivity. A new parametrization of tropospheric gradients whereby an arbitrary number of gradients are estimated as discrete directional wedges is shown via simulations to significantly improve the accuracy of recovered tropospheric zenith delays in asymmetric gradient scenarios. In a case study of an extreme rain event that occurred in September 2002 in southern France, the new directional parametrization is able to isolate the strong gradients in particular azimuths around the GPS stations consistent with the "V" shape spatial pattern of the observed precipitation. In another study of a network of GPS stations in the Sierra Nevada region where highly asymmetric tropospheric gradients are known to exist, the new directional model significantly improves the repeatabilities of the stations in asymmetric gradient situations while causing slightly degraded repeatabilities for the stations in normal symmetric gradient conditions. The average improvement over the entire network is ˜31%, while the improvement for one of the worst affected sites P631 is ˜49% (from 8.5 mm to 4.3 mm) in terms of weighted root-mean-square (WRMS) error and ˜82% (from -1.1 to -0.2) in terms of skewness. At the same station, the use of the directional model changes the estimates of zenith wet delay by 15 mm (˜25%).

  13. Directed growth of horizontally aligned gallium nitride nanowires for nanoelectromechanical resonator arrays.

    Science.gov (United States)

    Henry, Tania; Kim, Kyungkon; Ren, Zaiyuan; Yerino, Christopher; Han, Jung; Tang, Hong X

    2007-11-01

    We report the growth of horizontally aligned arrays and networks of GaN nanowires (NWs) as resonant components in nanoelectromechanical systems (NEMS). A combination of top-down selective area growth (SAG) and bottom-up vapor-liquid-solid (VLS) synthesis enables flexible fabrication of highly ordered nanowire arrays in situ with no postgrowth dispersion. Mechanical resonance of free-standing nanowires are measured, with quality factors (Q) ranging from 400 to 1000. We obtained a Young's modulus (E) of approximately 338 GPa from an array of NWs with varying diameters and lengths. The measurement allows detection of nanowire motion with a rotating frame and reveals dual fundamental resonant modes in two orthogonal planes. A universal ratio between the resonant frequencies of these two fundamental modes, irrespective of their dimensions, is observed and attributed to an isosceles cross section of GaN NWs.

  14. Angle and rotational direction dependent horizontal loop shift in epitaxial Co/CoO bilayers on MgO(100

    Directory of Open Access Journals (Sweden)

    Andrea Ehrmann

    2017-11-01

    Full Text Available Co/CoO belongs to the typical exchange bias systems which have been investigated for decades. Surprisingly, Co/CoO thin film systems epitaxially grown on MgO(100 substrates show a strong influence of the relative orientation of the average uncompensated antiferromagnetic magnetization with respect to the cooling field direction, giving rise to unexpected asymmetric angular dependencies of the horizontal loop shift as well as the sign of the transverse magnetization peaks in magneto-optical Kerr effect (MOKE experiments. In this paper, we provide a broad overview of the influence of cooling field orientation and sample orientation on magnetization reversal processes in this system.

  15. Experimental and numerical investigations on the direct contact condensation phenomenon in horizontal flow channels and its implications in nuclear safety

    Energy Technology Data Exchange (ETDEWEB)

    Ceuca, Sabin Cristian [Gesellschaft fuer Anlagen- und Reaktorsicherheit (GRS) gGmbH, Garching (Germany); Laurinavicius, Darius [Lithuanian Energy Institute, Kaunas (Lithuania)

    2016-11-15

    The complex direct contact condensation phenomenon is investigated in horizontal flow channels both experimentally and numerically with special emphasis on its implications on safety assessment studies. Under certain conditions direct contact condensation can act as the driving force for the water hammer phenomenon with potentially local devastating results, thus posing a threat to the integrity of the affected NPP components. New experimental results of in-depth analysis of the direct contact condensation phenomena obtained in Kaunas at the Lithuanian Energy Institute will be presented. The German system code ATHLET employing for the calculation of the heat transfer coefficient a mechanistic model accounting for two different eddy length scales, combined with the interfacial area transport equation will be assessed against condensation induced water hammer experimental data from the integral thermal-hydraulic experimental facility PMK-2, located at the KFKI Atomic Energy Research Institute in Budapest Hungary.

  16. Rules to fly by: pigeons navigating horizontal obstacles limit steering by selecting gaps most aligned to their flight direction.

    Science.gov (United States)

    Ros, Ivo G; Bhagavatula, Partha S; Lin, Huai-Ti; Biewener, Andrew A

    2017-02-06

    Flying animals must successfully contend with obstacles in their natural environments. Inspired by the robust manoeuvring abilities of flying animals, unmanned aerial systems are being developed and tested to improve flight control through cluttered environments. We previously examined steering strategies that pigeons adopt to fly through an array of vertical obstacles (VOs). Modelling VO flight guidance revealed that pigeons steer towards larger visual gaps when making fast steering decisions. In the present experiments, we recorded three-dimensional flight kinematics of pigeons as they flew through randomized arrays of horizontal obstacles (HOs). We found that pigeons still decelerated upon approach but flew faster through a denser array of HOs compared with the VO array previously tested. Pigeons exhibited limited steering and chose gaps between obstacles most aligned to their immediate flight direction, in contrast to VO navigation that favoured widest gap steering. In addition, pigeons navigated past the HOs with more variable and decreased wing stroke span and adjusted their wing stroke plane to reduce contact with the obstacles. Variability in wing extension, stroke plane and wing stroke path was greater during HO flight. Pigeons also exhibited pronounced head movements when negotiating HOs, which potentially serve a visual function. These head-bobbing-like movements were most pronounced in the horizontal (flight direction) and vertical directions, consistent with engaging motion vision mechanisms for obstacle detection. These results show that pigeons exhibit a keen kinesthetic sense of their body and wings in relation to obstacles. Together with aerodynamic flapping flight mechanics that favours vertical manoeuvring, pigeons are able to navigate HOs using simple rules, with remarkable success.

  17. 3D Simulations of Deep Directional Electromagnetic Tools in High-angle and Horizontal Wells

    OpenAIRE

    Puzyrev, Vladimir; Torres-Verdin, Carlos

    2016-01-01

    The first author acknowledges the RISE Horizon 2020 European Project GEAGAM (644202) for the travel support and the Repsol-BSC Research Center for funding. All numerical tests were performed on the MareNostrum supercomputer of the Barcelona Supercomputing Center. We also acknowledge the University of Texas at Austin’s Research Consortium on Formation Evaluation. A new generation of deep directional electromagnetic imaging tools is being adopted by the industry to enhance the efficiency ...

  18. Horizontal Directionality of Ambient Sea Noise in the North Pacific Ocean

    Science.gov (United States)

    1976-05-01

    directionalities for tihe high , mecan ,ard •,i• low beam responses foi all 40-Hz TASS polygon legs at n-3. (C) C.ONFIDENTI -53 $1 ft7’ 777777 I ~CONFI...the beamformer in high gain or low gain, a 20-dB gain differince. The mecan intensity of each s-equence except the Hansen-Woodyard endfire beam data...mechanisms which will introduce into the SOFAR channel noise from ships along the basin boundaries and at high latitudes. Once trapped in the channel

  19. Horizontal direction drill shore approach - a unique field joint coating system

    Energy Technology Data Exchange (ETDEWEB)

    Buchanan, Robert; Lemuchi, Andre; Gudme, Carl [Canusa-CPS, Toronto, ON (Canada)

    2005-07-01

    High performance pipeline coatings such as 3-layer polypropylene (3LPP) have been developed to meet the more demanding applications of today's pipelines. For offshore applications, this coating type is ideal because it offers lay contractors a tough, virtually holiday free coating, which enhances lay speeds. However, the field joint on polypropylene-coated pipe is one of the challenges for contractors who want to maximize lay speed and minimize cost. In recent years, a polypropylene-based heat-shrinkable sleeve has been developed to overcome some of the issues that lay contractors had, and the system is in widespread use globally. At the point where offshore pipelines transition to onshore sections the construction has also been a major challenge. Recently, contractors have used a system whereby they trench or directionally drill the pipeline up the shore approach then directionally drill through sensitive areas beyond the beach. This minimizes the environmental impact at the shoreline and can be quite cost effective. Again, the challenge of a more universally accepted field joint solution for polypropylene-coated pipelines that could withstand the rigours of the construction method was present. (author)

  20. Prosocial Motivation, Stress and Burnout among Direct Support Workers

    Science.gov (United States)

    Hickey, Robert

    2014-01-01

    Aim: This study explores whether the desire to engage in work that is beneficial to others moderates the effects of stress on burnout. Method: Based on a survey of 1570 direct support professionals in Ontario, this study conducted linear regression analyses and tested for the interaction effects of prosocial motivation on occupational stress and…

  1. Correlation between the horizontal wind direction and orientation of cross-field anisotropy of small-scale irregularities in the F region of midlatitude ionosphere

    Science.gov (United States)

    Romanova, N. Yu.

    2017-07-01

    Radio sounding of midlatitude ionosphere shows that natural small-scale electron density irregularities in the F region are cross-field anisotropic. The orientation of the cross-field anisotropy is different under different geophysical conditions. The cross-field anisotropy orientation is matched with the horizontal wind direction calculated within the HWM07 model for each event. It is ascertained that natural irregularities in a plane perpendicular to the magnetic field are stretched along the horizontal wind direction under different geophysical conditions.

  2. Stress and strain provide positional and directional cues in development.

    Directory of Open Access Journals (Sweden)

    Behruz Bozorg

    2014-01-01

    Full Text Available The morphogenesis of organs necessarily involves mechanical interactions and changes in mechanical properties of a tissue. A long standing question is how such changes are directed on a cellular scale while being coordinated at a tissular scale. Growing evidence suggests that mechanical cues are participating in the control of growth and morphogenesis during development. We introduce a mechanical model that represents the deposition of cellulose fibers in primary plant walls. In the model both the degree of material anisotropy and the anisotropy direction are regulated by stress anisotropy. We show that the finite element shell model and the simpler triangular biquadratic springs approach provide equally adequate descriptions of cell mechanics in tissue pressure simulations of the epidermis. In a growing organ, where circumferentially organized fibers act as a main controller of longitudinal growth, we show that the fiber direction can be correlated with both the maximal stress direction and the direction orthogonal to the maximal strain direction. However, when dynamic updates of the fiber direction are introduced, the mechanical stress provides a robust directional cue for the circumferential organization of the fibers, whereas the orthogonal to maximal strain model leads to an unstable situation where the fibers reorient longitudinally. Our investigation of the more complex shape and growth patterns in the shoot apical meristem where new organs are initiated shows that a stress based feedback on fiber directions is capable of reproducing the main features of in vivo cellulose fiber directions, deformations and material properties in different regions of the shoot. In particular, we show that this purely mechanical model can create radially distinct regions such that cells expand slowly and isotropically in the central zone while cells at the periphery expand more quickly and in the radial direction, which is a well established growth pattern

  3. Magnetic Field - Horizontal Component of the Total Field Intensity for the Epoch 2010.0 - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This map layer shows lines of equal horizontal intensity of the Earth's magnetic field, derived from the International Geomagnetic Reference Field (IGRF) for the...

  4. Direct stress measurements in a shallow, sinuous estuary

    Science.gov (United States)

    Seim, Harvey E.; Blanton, Jackson O.; Gross, Thomas

    2002-07-01

    Observations from a 4 element mooring array collected in a bend of a shallow, sinuous estuary are used to describe the flow, density structure and momentum balance over a 10-day period. In general, the flow in the lower 3 m is stratified on ebb and unstratified on flood and shear is concentrated near the bed on flood and nearly uniform throughout the water column on ebb. At spring tides stratification is reduced and the flows 1 m above bottom (mab) are consistently greatest at the downstream end of the bend. The along-channel density gradient is weakest during spring tides owing to zero gradient over most of ebb flow. At neap tides vertical stratification is strong enough to raise the gradient Richardson number well above 0.25 for most of the ebb tide. Currents are weaker and do not display a regular along-channel pattern. The variation in density and current structure is interpreted to result from variations in cross-channel circulation associated with the channel bend. At spring tides, the cross-channel circulation appears to be strong enough to overturn the water column whereas at neap tides stratification is strong enough to halt the overturning. Reynolds stress measured with a Benthic Acoustic Stress Sensor undergoes a four-fold increase between neap and spring tide. The drag coefficient relative to flow at 1 mab is 0.0015-0.0025. Bed stress in the bend is estimated using this drag coefficient and the maximum instantaneous velocity at 1 mab over the array. Because of the along-channel variability in current speed, the estimated bed stress is roughly twice as large as the measured Reynolds stress in the middle of the bend. The estimated bed stress is found to balance the horizontal pressure gradient and local acceleration, implying that a depth-averaged linear momentum balance adequately describes the dynamics on the bend when the impact of the cross-channel circulation is taken into account in the estimate of the bottom stress.

  5. Pressure Transient Analysis and Flux Distribution for Multistage Fractured Horizontal Wells in Triple-Porosity Reservoir Media with Consideration of Stress-Sensitivity Effect

    Directory of Open Access Journals (Sweden)

    Jingjing Guo

    2015-01-01

    Full Text Available Triple-porosity model is usually adopted to describe reservoirs with multiscaled pore spaces, including matrix pores, natural fractures, and vugs. Multiple fractures created by hydraulic fracturing can effectively improve the connectivity between existing natural fractures and thus increase well deliverability. However, little work has been done on pressure transient behavior of multistage fractured horizontal wells in triple-porosity reservoirs. Based on source/sink function method, this paper presents a triple-porosity model to investigate the transient pressure dynamics and flux distribution for multistage fractured horizontal wells in fractured-vuggy reservoirs with consideration of stress-dependent natural fracture permeability. The model is semianalytically solved by discretizing hydraulic fractures and Pedrosa’s transformation, perturbation theory, and integration transformation method. Type curves of transient pressure dynamics are generated, and flux distribution among hydraulic fractures for a fractured horizontal well with constant production rate is also discussed. Parametric study shows that major influential parameters on transient pressure responses are parameters pertinent to reservoir properties, interporosity mass transfer, and hydraulic fractures. Analysis of flux distribution indicates that flux density gradually increases from the horizontal wellbore to fracture tips, and the flux contribution of outermost fractures is higher than that of inner fractures. The model can also be extended to optimize hydraulic fracture parameters.

  6. The effect of multi-channel wide dynamic range compression, noise reduction, and the directional microphone on horizontal localization performance in hearing aid wearers.

    Science.gov (United States)

    Keidser, Gitte; Rohrseitz, Kristin; Dillon, Harvey; Hamacher, Volkmar; Carter, Lyndal; Rass, Uwe; Convery, Elizabeth

    2006-10-01

    This study examined the effect that signal processing strategies used in modern hearing aids, such as multi-channel WDRC, noise reduction, and directional microphones have on interaural difference cues and horizontal localization performance relative to linear, time-invariant amplification. Twelve participants were bilaterally fitted with BTE devices. Horizontal localization testing using a 360 degrees loudspeaker array and broadband pulsed pink noise was performed two weeks, and two months, post-fitting. The effect of noise reduction was measured with a constant noise present at 80 degrees azimuth. Data were analysed independently in the left/right and front/back dimension and showed that of the three signal processing strategies, directional microphones had the most significant effect on horizontal localization performance and over time. Specifically, a cardioid microphone could decrease front/back errors over time, whereas left/right errors increased when different microphones were fitted to left and right ears. Front/back confusions were generally prominent. Objective measurements of interaural differences on KEMAR explained significant shifts in left/right errors. In conclusion, there is scope for improving the sense of localization in hearing aid users.

  7. Horizontal visibility graph transfer entropy (HVG-TE): A novel metric to characterize directed connectivity in large-scale brain networks.

    Science.gov (United States)

    Yu, Meichen; Hillebrand, Arjan; Gouw, Alida A; Stam, Cornelis J

    2017-08-01

    We propose a new measure, horizontal visibility graph transfer entropy (HVG-TE), to estimate the direction of information flow between pairs of time series. HVG-TE quantifies the transfer entropy between the degree sequences of horizontal visibility graphs derived from original time series. Twenty-one Rössler attractors unidirectionally coupled in the posterior-to-anterior direction were used to simulate 21-channel Electroencephalography (EEG) brain networks and validate the performance of the HVG-TE. We showed that the HVG-TE is robust to different levels of coupling strengths between the coupled Rössler attractors, a wide range of time delays, different sample sizes, the effects of noise and linear mixing, and the choice of reference for EEG data. We also applied HVG-TE to EEG data in 20 healthy controls and compared its performance to a recently introduces phase-based TE measure (PTE). We found that compared with PTE, HVG-TE consistently detected stronger posterior-to-anterior information flow patterns in the alpha-band (8-13Hz) EEG brain networks for three different references. Moreover, in contrast to PTE, HVG-TE does not require an assumption on the periodicity of input signals, therefore it can be more widely applicable, even for non-periodic signals. This study shows that the HVG-TE is a directed connectivity measure to characterise the direction of information flow in large-scale brain networks. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. Horizontal Accelerator

    Data.gov (United States)

    Federal Laboratory Consortium — The Horizontal Accelerator (HA) Facility is a versatile research tool available for use on projects requiring simulation of the crash environment. The HA Facility is...

  9. Work ability and stress in a bus transportation company in Belo Horizonte, Brazil Avaliação da capacidade para o trabalho e estresse em uma empresa de transporte coletivo de Belo Horizonte, Brasil

    Directory of Open Access Journals (Sweden)

    Rosana Ferreira Sampaio

    2009-02-01

    Full Text Available Demographic, occupational and psychosocial characteristics affect the health and occupational performance of workers. The objective of the present study was to elaborate a profile of the work ability and factors that affect it in a bus transportation company in Belo Horizonte, Brazil. The instruments used included a socio-demographic and occupational questionnaire, the Work Ability Index and the Job Stress Scale. Demographic information revealed that 85.7% of the 126 employees of the company were active workers, 98% were males, with an average of 39 years of age (SD= 10 and 79 months working in the company (SD= 68; more than half reported having a low schooling level. In terms of personal habits, 88% were exposed to one or more risk factors, especially a sedentary lifestyle. The average strain value (as a consequence of stress was 0.78 (SD= 0.2 and 75.3% reported episodes of violence at the workplace. The work ability was good to excellent among 89% of the workers. Results from the logistic regression analysis showed that strain was the only significant variable in relation to the Work Ability Index, (estimated odds ratio of 0.02. The results suggest that psychosocial factors presented the greatest association with work ability, and preventive and/or corrective measures should be implemented.Características demográficas, ocupacionais e psicossociais afetam a saúde e o desempenho dos trabalhadores. O objetivo deste estudo foi elaborar um perfil da capacidade para o trabalho e fatores que a afetam em uma empresa de transporte coletivo de Belo Horizonte, Brasil. Os instrumentos utilizados foram o Índice de Capacidade para o Trabalho, a Job Stress Scale e um questionário sociodemográfico e ocupacional. Dos 126 trabalhadores, 14,3% estavam aposentados ou afastados, todos por doença. Entre os ativos, a maioria era do sexo masculino (98%, com idade média de 39 anos (DP=10, baixa escolaridade (acima de 50% e tempo médio na empresa de 79 meses

  10. Collecting underground seawater with directed horizontal drains on the coast; Captacion en el litroal de agua marina subterranea con drenes horizontales dirigidos

    Energy Technology Data Exchange (ETDEWEB)

    Camps Querol, J.

    2007-07-01

    On the face of it, given the huge amount of seawater available on the sea coast, obtaining such water for use as a raw material should be a relatively simple task. It certainly is when we collect some in a bucket at the beach, but it is not so simple when large quantities are required so that they can be desalinised, as there are various factors that make collecting it more difficult. That is why this article presents a collection technique that uses directed horizontal drains under the sea bed which makes it possible to collect seawater that is unclouded and free of organic matter, properties that greatly facilities its subsequent treatment with membrane techniques. (Author) 7 refs.

  11. Marine environmental pollution stress detection through direct viable counts of bacteria

    Digital Repository Service at National Institute of Oceanography (India)

    Ramaiah, N.; Kenkre, V.D.; Verlecar, X.N.

    Direct viable counts (DVC) of bacteria were quantified from polluted and relatively less/non-polluted coastal locations during different seasons to assess whether they can be routinely monitored for an understanding of environmental stress(es...

  12. The Salmonella enterica PhoP directly activates the horizontally acquired SPI-2 gene sseL and is functionally different from a S. bongori ortholog.

    Directory of Open Access Journals (Sweden)

    Ohad Gal-Mor

    Full Text Available To establish a successful infection within the host, a pathogen must closely regulate multiple virulence traits to ensure their accurate temporal and spatial expression. As a highly adapted intracellular pathogen, Salmonella enterica has acquired during its evolution various virulence genes via numerous lateral transfer events, including the acquisition of the Salmonella Pathogenicity Island 2 (SPI-2 and its associated effectors. Beneficial use of horizontally acquired genes requires that their expression is effectively coordinated with the already existing virulence programs and the regulatory set-up in the bacterium. As an example for such a mechanism, we show here that the ancestral PhoPQ system of Salmonella enterica is able to regulate directly the SPI-2 effector gene sseL (encoding a secreted deubiquitinase in an SsrB-independent manner and that PhoP plays a part in a feed-forward regulatory loop, which fine-tunes the cellular level of SseL. Additionally, we demonstrate the presence of conserved cis regulatory elements in the promoter region of sseL and show direct binding of purified PhoP to this region. Interestingly, in contrast to the S. enterica PhoP, an ortholog regulator from a S. bongori SARC 12 strain was found to be impaired in promoting transcription of sseL and other genes from the PhoP regulon. These findings have led to the identification of a previously uncharacterized residue in the DNA-binding domain of PhoP, which is required for the transcriptional activation of PhoP regulated genes in Salmonella spp. Collectively our data demonstrate an interesting interface between the acquired SsrB regulon and the ancestral PhoPQ regulatory circuit, provide novel insights into the function of PhoP, and highlight a mechanism of regulatory integration of horizontally acquired genes into the virulence network of Salmonella enterica.

  13. Numerical Investigation of Wind Conditions for Roof-Mounted Wind Turbines: Effects of Wind Direction and Horizontal Aspect Ratio of a High-Rise Cuboid Building

    Directory of Open Access Journals (Sweden)

    Takaaki Kono

    2016-11-01

    Full Text Available From the viewpoint of installing small wind turbines (SWTs on rooftops, this study investigated the effects of wind direction and horizontal aspect ratio (HAR = width/length of a high-rise cuboid building on wind conditions above the roof by conducting large eddy simulations (LESs. The LES results confirmed that as HAR decreases (i.e., as the building width decreases, the variation in wind velocity over the roof tends to decrease. This tendency is more prominent as the angle between the wind direction and the normal vector of the building’s leeward face with longer roof edge increases. Moreover, at windward corners of the roof, wind conditions are generally favorable at relatively low heights. In contrast, at the midpoint of the roof's windward edge, wind conditions are generally not favorable at relatively low heights. At leeward representative locations of the roof, the bottoms of the height range of favorable wind conditions are typically higher than those at the windward representative locations, but the favorable wind conditions are much better at the leeward representative locations. When there is no prevailing wind direction, the center of the roof is more favorable for installing SWTs than the corners or the edge midpoints of the roof.

  14. Sixteen year variation of horizontal phase velocity and propagation direction of mesospheric and thermospheric waves in airglow images at Shigaraki, Japan

    Science.gov (United States)

    Takeo, D.; Shiokawa, K.; Fujinami, H.; Otsuka, Y.; Matsuda, T. S.; Ejiri, M. K.; Nakamura, T.; Yamamoto, M.

    2017-08-01

    We analyzed the horizontal phase velocity of gravity waves and medium-scale traveling ionospheric disturbances (MSTIDs) by using the three-dimensional fast Fourier transform method developed by Matsuda et al. (2014) for 557.7 nm (altitude: 90-100 km) and 630.0 nm (altitude: 200-300 km) airglow images obtained at Shigaraki MU Observatory (34.8°N, 136.1°E, dip angle: 49°) over ˜16 years from 16 March 1999 to 20 February 2015. The analysis of 557.7 nm airglow images shows clear seasonal variation of the propagation direction of gravity waves in the mesopause region. In spring, summer, fall, and winter, the peak directions are northeastward, northeastward, northwestward, and southwestward, respectively. The difference in east-west propagation direction between summer and winter is probably caused by the wind filtering effect due to the zonal mesospheric jet. Comparison with tropospheric reanalysis data shows that the difference in north-south propagation direction between summer and winter is caused by differences in the latitudinal location of wave sources due to convective activity in the troposphere relative to Shigaraki. The analysis of 630.0 nm airglow images shows that the propagation direction of MSTIDs is mainly southwestward with a minor northeastward component throughout the 16 years. A clear negative correlation is seen between the yearly power spectral density of MSTIDs and F10.7 solar flux. This negative correlation with solar activity may be explained by the linear growth rate of the Perkins instability and secondary wave generation of gravity waves in the thermosphere.

  15. Generation of operational maps of global solar irradiation on horizontal plan and of direct normal irradiation from Meteosat imagery by using SOLARMET

    Energy Technology Data Exchange (ETDEWEB)

    Cogliani, E.; Maccari, A. [ENEA, Agency for New Technologies, Energy and Environment, C.R. Casaccia, TER/Solterm-Svil, P.O. Box 117, Via Anguillarese 301, 00123 Santa Maria di Galeria, Rome (Italy); Ricchiazzi, P. [ICESS, Institute for Computational Earth System Science, University of California at Santa Barbara, Santa Barbara, CA 93106-3060 (United States)

    2008-06-15

    The physical model SOLARMET, elaborated in ENEA (Italian National Agency for New Technologies, Energy and Environment), provides hourly average global solar irradiance on a horizontal surface (GHi) and hourly average direct normal solar irradiance (DNi) for Italy based on primary satellite images in the visible band. In the present study, the hourly estimates of surface radiation generated by SOLARMET have been summed up to produce monthly average daily irradiation maps. Hourly and monthly maps were done for the years 1996 and 2002. The parameters of this model were obtained by comparing the Meteosat satellite data with ground data gathered in 2002. Differences, relative to 1996, between SOLARMET estimates and observations obtained over two radiation networks of Italian ground sites are presented: the Meteorological Service of the Italian Air Force and National Agro-Meteorological Network; In total 51 ground stations. The comparison between SOLARMET and the previous Italian method carried out in ENEA shows an improvement due to SOLARMET. Such comparison between the values derived using SOLARMET and previous ENEA methodologies and with data from ground-based stations was possible only for monthly averages of daily global radiation due to an almost total lack of direct radiation ground data in Italy. The operational monthly solar radiation maps, showing solar energy potentials, permit the selection of construction sites to solar energy project developers. In Italy, these data are necessary for installing solar thermal concentration power plants in support of the R and S program recently funded to demonstrate the possibility of these technologies. (author)

  16. Evolution of consumer protection law in the light of the Proposal for a Horizontal Directive on Consumer Rights and Rome I Regulation

    Directory of Open Access Journals (Sweden)

    Anna Łuczak

    2011-12-01

    Full Text Available The aim of this paper is to give a broad analysis of changes in the field of consumer protection law in the European Union over three decades. In 2004, the European Commission launched a project of reviewing consumer law in order to strengthen consumers’ confidence in the internal market and to encourage businesses to conduct cross-border trading. The EU consumer protection regulatory framework is based on directives including a minimum harmonization clause. This clause allows Member States to maintain or adopt stricter consumer protection rules and leads to fragmentation in their national laws. For instance, it was found that the notion and definition of a consumer has been designed for use by a specific directive, depending on which area is covered by the regulation of the personal scope. The definition of the so-called weaker party in a contractual relationship is understood in a narrow way, which is highlighted in the established line of the European Court of Justice case law. A brief outline of the history of the shaping of consumer protection policy in the European Union is presented to demonstrate how the problem of amending consumer protection law has evolved in the EU as well as increased in importance; this has been demonstrated in several programs and resolutions of the European Parliament and communications of the European Commission, which discuss the need to reform consumer contract law. The Proposal for a Horizontal Directive on Consumer Rights is the result of a review of consumer law acquis communautaire, referred to as the Consumer Acquis, and aims at introducing a full harmonization clause where feasible. Until recently, the norms governing the determination of the law applicable to consumer contracts have been defined by the Rome Convention of 1980 on the law applicable to contract relations. Due to its overly casuistic nature and outdated provisions relating to consumer contracts, it was decided to amend the Convention

  17. Real-time monitoring of methanol concentration using a shear horizontal surface acoustic wave sensor for direct methanol fuel cell without reference liquid measurement

    Science.gov (United States)

    Tada, Kyosuke; Nozawa, Takuya; Kondoh, Jun

    2017-07-01

    In recent years, there has been an increasing demand for sensors that continuously measure liquid concentrations and detect abnormalities in liquid environments. In this study, a shear horizontal surface acoustic wave (SH-SAW) sensor is applied for the continuous monitoring of liquid concentrations. As the SH-SAW sensor functions using the relative measurement method, it normally needs a reference at each measurement. However, if the sensor is installed in a liquid flow cell, it is difficult to measure a reference liquid. Therefore, it is important to establish an estimation method for liquid concentrations using the SH-SAW sensor without requiring a reference measurement. In this study, the SH-SAW sensor is installed in a direct methanol fuel cell to monitor the methanol concentration. The estimated concentration is compared with a conventional density meter. Moreover, the effect of formic acid is examined. When the fuel temperature is higher than 70 °C, it is necessary to consider the influence of liquid conductivity. Here, an estimation method for these cases is also proposed.

  18. Left-handers' struggle in a rightward wor(l)d: The relation between horizontal spatial bias and effort in directed movements.

    Science.gov (United States)

    Suitner, Caterina; Maass, Anne; Bettinsoli, Maria Laura; Carraro, Luciana; Kumar, Serena

    2017-01-01

    Five studies investigated the role of handedness and effort in horizontal spatial bias related to agency (Spatial Agency Bias, SAB). A Pilot Study (n = 33) confirmed the basic assumption that rightward writing requires greater effort from left- than from right-handers. In three studies, Italian students (n = 591 right-handed, n = 115 left-handed) were found to start drawings on the left, proceeding rightward (Study 1a, 1b), and to draw moving objects with a rightward orientation in line with script direction (Study 1c). These spatial asymmetries were displayed stronger by left- than by right-handed primacy school children, arguably due to the greater effort involved in learning how to write in a rightward fashion. Once writing has become fully automatic (high school) right- and left-handed students showed comparable spatial bias (Study 1c). The hypothesized role of effort was tested explicitly in Study 2 in which 99 right-handed adults learned a new (leftward) spatial trajectory through an easy or difficult motor exercise. The habitual rightward bias was reliably reduced, especially among those who performed a difficult task requiring greater effort. Together, findings are largely in line with the body specificity hypothesis (Casasanto, 2011 ) and suggest that spatial asymmetries are learned and unlearned most efficiently through effortful motor exercises.

  19. Burnout, Stress and Direct Student Services among School Counselors

    Science.gov (United States)

    Mullen, Patrick R.; Gutierrez, Daniel

    2016-01-01

    The burnout and stress experienced by school counselors is likely to have a negative influence on the services they provide to students, but there is little research exploring the relationship among these variables. Therefore, we report findings from our study that examined the relationship between practicing school counselors' (N = 926) reported…

  20. The stressed prefrontal cortex and goal-directed behaviour: acute psychosocial stress impairs the flexible implementation of task goals.

    Science.gov (United States)

    Plessow, Franziska; Kiesel, Andrea; Kirschbaum, Clemens

    2012-02-01

    Goals are often at the basis of human actions. As an essential mechanism of behavioural adaptation, individuals need to be able to flexibly implement new task goals so as to alter their actions (switch tasks) in response to contextual changes. The present study investigated the effect of acute psychosocial stress on cognitive control processes of flexible task-goal implementation with temporal focus on the occurrence interval of the hypothalamus-pituitary-adrenal (HPA) stress response. For this, forty-eight healthy volunteers were either challenged with a standardised stress-induction protocol (the Trier Social Stress Test) or underwent a standardised control situation. Subsequently, they were exposed to a task-switching procedure with two tasks alternating in random order. Participants of the stress group displayed increased salivary α-amylase activity immediately after stress exposure as well as elevations of salivary cortisol from 10 min after stress cessation, reflecting the typical stress-related activity increases in the sympathetic nervous system and the HPA axis, respectively. At the time interval of elevated cortisol levels, stressed individuals persistently showed larger performance differences between task switches and task repetitions (switch costs) than controls. This effect was reliably evident when tested 5-20 min as well as 25-40 min following treatment cessation. These results indicate that acute psychosocial stress impairs cognitive control processes of flexible task-goal implementation essential for voluntary goal-directed behaviour.

  1. Magnetic Field - Secular Variation of the Horizontal Component of the Total Field Intensity for the Epoch 2010.0 - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This map layer shows lines of equal annual change (secular variation) in the horizontal component of the total field intensity of the Earth's magnetic field, derived...

  2. Stress Dependence of Ultrasonic Velocity in Unidirectional Graphite/Epoxy Composites for Longitudinal Waves Propagating Along the Direction of Stress

    Science.gov (United States)

    Prosser, William H.

    1990-01-01

    The first measurements of the stress induced velocity changes for propagation directions along the direction of applied stress in gr/ep composites have been presented. For propagation and stress direction perpendicular to the fiber direction, the data demonstrated a linear relation between normalized velocity shift and stress. After corrections for the delay line were made, the slope or SAC was determined and compared favorably with the expected value calculated from the previously determined nonlinear coefficients of this material. The ratio of the SAC to the elastic compliance for this direction of loading was evaluated and found to have a value similar to numerous other materials which have very different linear elastic properties. Measurements with stress and propagation along the fibers yielded unusual behavior. The curves were very nonlinear and even shifted direction at higher loads. The large scatter in the data due to bond variations made separation of material effects from bond induced artifacts impossible. Thus the SAC, R, and the remaining two unknown TOEC's could not be determined for this direction of propagation. These measurements further expand the basis of determining nonlinear elastic properties of composite materials. These properties may be useful in developing much needed NDE techniques to determine such important parameters as residual stress after cure and residual strength after impact damage. Additional study is needed to measure the nonlinear behavior in other composite materials including angle ply laminates. Also, other techniques to measure elastic nonlinearity such as harmonic generation should be applied to composites to improve the understanding of these properties and their importance.

  3. The direction of word stress processing in German: evidence from a working memory paradigm

    OpenAIRE

    Frank eDomahs; Marion eGrande; Walter eHuber; Ulrike eDomahs

    2014-01-01

    There are contradicting assumptions and findings on the direction of word stress processing in German. To resolve this question, we asked participants to read tri-syllabic nonwords and stress ambiguous words aloud. Additionally, they also performed a working memory task (2-back task). In nonword reading, participants’ individual working memory capacity was positively correlated with assignment of main stress to the antepenultimate syllable, which is most distant to the word’s right edge, whil...

  4. Occupational stress in intensive care nurses who provide direct care to critical patients

    National Research Council Canada - National Science Library

    Inoue, Kelly Cristina; Versa, Gelena Lucinéia Gomes da Silva; Murassaki, Ana Cláudia Yassuko; Melo, Willian Augusto de; Matsuda, Laura Misue

    2013-01-01

    In order to identify the stress level of nurses that provide direct care to critically ill patients, it was carried out a descriptive and exploratory study in five hospitals of the western region of the state of Paraná...

  5. Stages of Learning during a Self-Directed Stress Management Experience

    Science.gov (United States)

    Larson, Karl L.

    2015-01-01

    Purpose: The purpose of the study was to document the stages of learning reflected through student journaling during a self-directed experience in stress management, and the relationship of those stages to a historical model. Methods: College students participating in a full-semester course in stress management theory were required to select a…

  6. Comparative study for salt stress among seed, root stock and direct ...

    African Journals Online (AJOL)

    The experiments were carried out to evaluate the comparative study for salt stress among seed, root stock and direct regenerated violet (Viola odorata L.) seedlings. Violet seedlings propagated through tissue culture (direct regeneration) had significantly higher salicylic acid (SA) concentrations from seed and rootstock ...

  7. The direction of word stress processing in German: Evidence from a working memory paradigm

    Directory of Open Access Journals (Sweden)

    Frank eDomahs

    2014-06-01

    Full Text Available There are contradicting assumptions and findings on the direction of word stress processing in German. To resolve this question, we asked participants to read tri-syllabic nonwords and stress ambiguous words aloud. Additionally, they also performed a working memory task (2-back task. In nonword reading, participants’ individual working memory capacity was positively correlated with assignment of main stress to the antepenultimate syllable, which is most distant to the word’s right edge, while a (complementary negative correlation was observed with assignment of stress to the ultimate syllable. There was no significant correlation between working memory capacity and stress assignment to the penultimate syllable, which has been claimed to be the default stress pattern in German. In reading stress ambiguous words a similar but non-significant pattern was observed as in nonword reading. In sum, our results provide first psycholinguistic evidence supporting leftward stress processing in German. Our results do not lend support to the assumption of penultimate default stress in German. A specification of the lemma model is proposed which seems able to reconcile our findings and apparently contradicting assumptions and evidence.

  8. DIRECT CALCULUS FORMULAS FOR THE LATHE TOOL EQUIVALENT STRESS VALUES DURING THE MANUFACTURING OF STEEL SHAFTS

    Directory of Open Access Journals (Sweden)

    Catălin ROŞU

    2015-05-01

    Full Text Available In this paper, starting from the stress values presented in Roşu (2015 [1], a method for determining direct calculus formulas for the lathe tool equivalent stress values during the manufacturing of steel shafts is established. There is used the regression analysis for the formulas determination. The equivalent stress will be dependant on the cutting depth. The obtained formulas will be verified by using an analytical model from Strength of Materials. The results and the calculus formulas are presented from an original point of view.

  9. 49 CFR 192.929 - What are the requirements for using Direct Assessment for Stress Corrosion Cracking (SCCDA)?

    Science.gov (United States)

    2010-10-01

    ... Assessment for Stress Corrosion Cracking (SCCDA)? 192.929 Section 192.929 Transportation Other Regulations... requirements for using Direct Assessment for Stress Corrosion Cracking (SCCDA)? (a) Definition. Stress Corrosion Cracking Direct Assessment (SCCDA) is a process to assess a covered pipe segment for the presence...

  10. Natural vibration frequencies of horizontal tubes partially filled with liquid

    Science.gov (United States)

    Santisteban Hidalgo, Juan Andrés; Gama, Antonio Lopes; Moreira, Roger Matsumoto

    2017-11-01

    This work presents an experimental and numerical study on the flexural vibration of horizontal circular tubes partially filled with liquid. The tube is configured as a free-free beam with attention being directed to the case of small amplitudes of transverse oscillation whereas the axial movements of the tube and liquid are disregarded. At first vertical and horizontal polarizations of the flexural tube are investigated experimentally for different amounts of filling liquid. In contrast with the empty and fully-filled tubes, it is observed that natural frequencies of the vertical and horizontal polarizations are different due to asymmetry induced by the liquid layer, which acts like an added mass. Less mass of liquid is added to the tube when oscillating horizontally; as a consequence, eigenfrequencies for the horizontal polarization are found to be greater than the case of the vertically polarized tube. A simple method to calculate the natural vibration frequencies using coefficients of added mass of liquid is proposed. It is shown that the added mass coefficient increases with the liquid's level and viscosity. At last a numerical investigation of the interaction between the liquid and the tube is carried out by solving in two-dimensions the full Navier-Stokes equations via a finite volume method, with the free-surface flow being modeled with a homogeneous multiphase Eulerian-Eulerian fluid approach. Vertical and horizontal polarizations are imposed to the tube with pressure and shear stresses being determined numerically to assess the liquid's forcing onto the tube's wall. The coefficient of added mass of liquid is then estimated by the ratio between the resulting force and the acceleration imposed to the wall. A good agreement is found between experimental and numerical results, especially for the horizontally oscillating tube. It is also shown that viscosity can noticeably affect the added mass coefficients, particularly at low filling levels.

  11. Work Stress, Burnout, and Social and Personal Resources among Direct Care Workers

    Science.gov (United States)

    Gray-Stanley, Jennifer A.; Muramatsu, Naoko

    2011-01-01

    Work stress is endemic among direct care workers (DCWs) who serve people with intellectual and developmental disabilities. Social resources, such as work social support, and personal resources, such as an internal locus of control, may help DCWs perceive work overload and other work-related stressors as less threatening and galvanize them to cope…

  12. Residual stress determination of direct metal laser sintered (DMLS) inconel specimens and parts

    Energy Technology Data Exchange (ETDEWEB)

    Watkins, Thomas R. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Unocic, Kinga A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Maziasz, Philip J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Bunn, Jeffrey R. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Fancher, Christopher M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Peralta, Alonso [Honeywell Aerospace, Phoenix, AZ (United States); Sundarraj, Suresh [Honeywell Aerospace, Phoenix, AZ (United States); Neumann, James [Honeywell Aerospace, Phoenix, AZ (United States)

    2018-01-01

    Residual stress determinations and microstructural studies were performed on a series of Inconel 718Plus prisms built using Direct Metal Laser Sintering (DMLS) at Honeywell Aerospace (hereafter also referred to as Honeywell). The results are being used to validate and improve existing models at Honeywell, and ultimately will expedite the implementation of DMLS throughout various industrial sectors (automotive, biomedical, etc.).

  13. Software for determining the direction of movement, shear and normal stresses of a fault under a determined stress state

    Science.gov (United States)

    Álvarez del Castillo, Alejandra; Alaniz-Álvarez, Susana Alicia; Nieto-Samaniego, Angel Francisco; Xu, Shunshan; Ochoa-González, Gil Humberto; Velasquillo-Martínez, Luis Germán

    2017-07-01

    In the oil, gas and geothermal industry, the extraction or the input of fluids induces changes in the stress field of the reservoir, if the in-situ stress state of a fault plane is sufficiently disturbed, a fault may slip and can trigger fluid leakage or the reservoir might fracture and become damaged. The goal of the SSLIPO 1.0 software is to obtain data that can reduce the risk of affecting the stability of wellbores. The input data are the magnitudes of the three principal stresses and their orientation in geographic coordinates. The output data are the slip direction of a fracture in geographic coordinates, and its normal (σn) and shear (τ) stresses resolved on a single or multiple fracture planes. With this information, it is possible to calculate the slip tendency (τ/σn) and the propensity to open a fracture that is inversely proportional to σn. This software could analyze any compressional stress system, even non-Andersonian. An example is given from an oilfield in southern Mexico, in a region that contains fractures formed in three events of deformation. In the example SSLIPO 1.0 was used to determine in which deformation event the oil migrated. SSLIPO 1.0 is an open code application developed in MATLAB. The URL to obtain the source code and to download SSLIPO 1.0 are: http://www.geociencias.unam.mx/ alaniz/main_code.txt, http://www.geociencias.unam.mx/ alaniz/ SSLIPO_pkg.exe.

  14. [Environmental uncertainty and arousal/stress as the direct determinants of animal behaviour].

    Science.gov (United States)

    Popov, S V

    2010-01-01

    A model of direct behavioural mechanisms is suggested. The suggestion is founded on the following prerequisites: the law of optimum arousal by Yerkes-Dodson; the data on animals' purposeful striving towards the optimum; and the data on effect of stimuli uncertainty (unpredictability and/or uncontrollability) on susceptibility to the stimuli. The key postulate of the model is animals' ability to affect the environment uncertainty with their behaviour and, hence, to change their susceptibility to various stimuli and optimize their stress/arousal level. This function of behaviour had never been discussed and seems to be rather important for proximal behavioural mechanisms and for forming direct motives of behaviour. Optimization of arousal level may be viewed as "universal benefit" at the level of direct behavioural mechanisms (similar to "joint genetic fitness" at the level of evolutional mechanisms). Within the model framework it is possible to take up some sophisticated aspects of ethology such as social relations forming, "begging for punishment", "zoo stereotypy", and so on. Among verifiable predictions that can be derived from its analysis, the following ones are worthwhile: (1) the stronger of two similar social relations cannot be more stressful than the weaker one; (2) the intensity of marking activity never increases as arousal/stress level decreases; (3) stress/arousal level of an animal having been experienced "zoo stereotypy" for a long time can never be higher than that of a conspecific individual showing the behaviour for the first time; (4) the rate of "begging for punishment" behaviour of an individual should positively correlate with environmental uncertainty; (5) arousal/stress level of an individual looking for novelty can never be higher than arousal/stress level of the same individual when avoiding novelty; (6) the striving of a specimen for displaying the behaviour promoting an increase in uncertainty can be suppressed by raising the

  15. Do infants have the horizontal bias?

    NARCIS (Netherlands)

    van Renswoude, D.R.; Johnson, S.P.; Raijmakers, M.E.J.; Visser, I.

    2016-01-01

    A robust set of studies show that adults make more horizontal than vertical and oblique saccades, while scanning real-world scenes. In this paper we study the horizontal bias in infants. The directions of eye movements were calculated for 41 infants (M = 8.40 months, SD = 3.74, range = 3.48–15.47)

  16. Efecto de un calentamiento con estiramientos estáticos y dinámicos sobre el salto horizontal y la capacidad para repetir esprint con cambio de dirección. [Effect of warm-up with static and dynamic stretching on the horizontal jump and repeated sprint ability with changes of direction].

    Directory of Open Access Journals (Sweden)

    Javier Sánchez-Sánchez

    2017-01-01

    Full Text Available El objetivo de este trabajo ha sido comparar el efecto de tres calentamientos diferentes (calentamiento aeróbico de baja intensidad, estiramiento estático y estiramiento dinámico sobre el salto horizontal y la capacidad de repetir esprint con cambios de dirección. Diecisiete practicantes de deportes de equipo de 20.8±1.1 años realizaron 3 tipos de calentamiento (10 min: ejercicio aeróbico sin estiramiento (CAE, con estiramiento estático (CAES y con estiramiento dinámico (CAED. Se estudió el efecto agudo de cada calentamiento sobre el rendimiento en una prueba de salto horizontal (SH y un test de repetición de esprint con cambio de dirección (RSCOD. No se obtuvieron diferencias significativas (p>0,05 en ninguna de las variables en función del calentamiento realizado. El tamaño del efecto (TE indicó que probablemente el RSCODmejor sea más sensible al CAE que al CAES (TE: 0,52 y al CAED (TE: 0,44. El escaso efecto de los estiramientos estáticos sobre el rendimiento en SH y RSCOD puede ser debido a la dosis, la intensidad y el tiempo de recuperación empleado. Los estiramientos dinámicos no mejoraron el rendimiento en SH y RSCOD. Abstract The purpose of this study was to compare the effect of three different warm-ups (low intensity aerobic warm-up, static stretching and dynamic stretching on the horizontal jump and repeated sprint ability with changes of direction. Seventeen players of team sports whose age was 20.8±1.1 years old performed three types of warm up (10 minutes: aerobic exercise without stretching (WU, with static stretching (WUSS and with dynamic stretching (WUDS. The acute effect of each warming over performance was studied in a test of horizontal jump (HJ and repeat sprint test with change of direction (RSCD. No significant differences were obtained (p>0.05 in any of the variables studied according to the warming developed. The effect size (ES indicated that probably RSCDbest was more sensitive to WU than WUDS (ES

  17. Cognitive appraisals and problem-directed coping: a prospective study of stress.

    Science.gov (United States)

    Krantz, S E

    1983-03-01

    Information-seeking and problem-directed coping behaviors following a stressful event were observed as a function of cognitive appraisals of coping resources. Subjectively defined failure on a college exam served as an example of a mild stressor. Prior to the first midterm exam, students generated alternative strategies that could be used in the event of dissatisfaction with performance and rated the feasibility of using these strategies. Academic coping behaviors were measured by self-report and direct observation during the 3 weeks prior to the next exam. Coping cognitions were found to predict academic behaviors but not exam scores.

  18. Stress relaxation at a gelatin hydrogel-glass interface in direct shear sliding

    Science.gov (United States)

    Gupta, Vinit; Singh, Arun K.

    2018-01-01

    In this paper, we study experimentally the stress relaxation behavior of soft solids such as gelatin hydrogels on a smooth glass surface in direct shear sliding. It is observed experimentally that irrespective of pulling velocity, the sliding block relaxes to the same level of nonzero residual stress. However, residual stress increases with increasing gelatin concentration in the hydrogels. We have also validated a friction model for strong bond formation during steady relaxation in light of the experimental observations. Our theoretical analysis establishes that population of dangling chains at the sliding interface significantly affects the relaxation process. As a result, residual stress increases with increasing gelatin concentration or decreasing mesh size of the three-dimensional structures in the hydrogels. It is also found that the transition time, at which a weak bond converts to strong bond, increases with increasing mesh size of the hydrogels. Moreover, relaxation time constant of a strong bond decreases with increasing mesh size. However, activation length of a strong bond increases with mesh size. Finally, this study signifies the role of residual strength in frictional shear sliding and it is believed that these results should be useful to understand the role of residual stress in stick-slip instability.

  19. DIRECT EVALUATION OF OXIDATIVE STRESS AND ANTIOXIDANT DEFENSE PARAMETERS IN EXPERIMENT WITH THE AXIAL PUMP

    Directory of Open Access Journals (Sweden)

    N. V. Kuncevich

    2011-01-01

    Full Text Available It is established that increased parameters of oxidative stress result from an imbalance between reactive oxygen molecules and endogenous antioxidants. Oxidative stress parameters may be considered to be biomarkers of heart failure. The aim of our study was to asses oxidative stress and antioxidant system parameters in experi- mental model with the axial pump. Our study included 7 calves (the mean age 120.33 days, the mean weight 99.17 kg. We used «FORM Plus CR3000» analyzer (Callegary, Italy and heparinized venous blood samples for the evaluation of the oxidative status (FORT test and the total antioxidant capacity (FORD test. In healthy animals oxidative system parameters differ from those in humans (FORT – 0.42 ± 0.11 versus 1.74 ± 0.32 mmol/l H2O2; FORD/FORT – 3.92 ± 1.30 versus 1.33 ± 0.27, p < 0.05 what should be taken into consideration when interpreting the results of clinical and experimental studies. In three calves with experimental assisted circulation maximal oxidative stress values were observed on 1–3 days after the axial pump connection with the subsequent normalization of these parameters. Direct evaluation of oxidative stress parameters may be used as monitoring tool for estimation of assisted circulation adequacy in experiment (animal model. 

  20. Work stress, burnout, and social and personal resources among direct care workers.

    Science.gov (United States)

    Gray-Stanley, Jennifer A; Muramatsu, Naoko

    2011-01-01

    Work stress is endemic among direct care workers (DCWs) who serve people with intellectual and developmental disabilities. Social resources, such as work social support, and personal resources, such as an internal locus of control, may help DCWs perceive work overload and other work-related stressors as less threatening and galvanize them to cope more effectively to prevent burnout. However, little is known about what resources are effective for coping with what types of work stress. Thus, we examined how work stress and social and personal resources are associated with burnout for DCWs. We conducted a survey of DCWs (n = 323) from five community-based organizations that provide residential, vocational, and personal care services for adults with intellectual and developmental disabilities. Participants completed a self-administered survey about their perceptions of work stress, work social support, locus of control, and burnout relative to their daily work routine. We conducted multiple regression analysis to test both the main and interaction effects of work stress and resources with respect to burnout. Work stress, specifically work overload, limited participation decision-making, and client disability care, was positively associated with burnout (p social support and burnout depended on the levels of work overload (p burnout depended on the levels of work overload (p social support and locus of control make a difference depends on the kinds and the levels of work stressors. The findings underscore the importance of strong work-based social support networks and stress management resources for DCWs. Copyright © 2011 Elsevier Ltd. All rights reserved.

  1. Micromechanical modeling of stress-induced strain in polycrystalline Ni–Mn–Ga by directional solidification

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Yuping, E-mail: zhuyuping@126.com [Seismic Observation and Geophysical Imaging Laboratory, Institute of Geophysics, China Earthquake Administration, Beijing 100081 (China); Shi, Tao; Teng, Yao [Faculty of Civil Engineering and Mechanics, Jiangsu University, Zhenjiang 212013 (China)

    2015-10-05

    Highlights: • A micromechanical model of directional solidification Ni–Mn–Ga is developed. • The stress–strain curves in different directions are tested. • The martensite Young’s moduli in different directions are predicted. • The macro reorientation strains in different directions are investigated. - Abstract: Polycrystalline ferromagnetic shape memory alloy Ni–Mn–Ga produced by directional solidification possess unique properties. Its compressive stress–strain behaviors in loading–unloading cycle show nonlinear and anisotropic. Based on the self-consistent theory and thermodynamics principle, a micromechanical constitutive model of polycrystalline Ni–Mn–Ga by directional solidification is developed considering the generating mechanism of the macroscopic strain and anisotropy. Then, the stress induced strains at different angles to solidification direction are calculated, and the results agree well with the experimental data. The predictive curves of martensite Young’s modulus and macro reorientation strain in different directions are investigated. It may provide theoretical guidance for the design and use of ferromagnetic shape memory alloy.

  2. Techniques for determining subsurface stress direction and assessing hydraulic fracture azimuth

    Energy Technology Data Exchange (ETDEWEB)

    Hill, R.E.; Peterson, R.E.; Warpinski, N.R.; Lorenz, J.C.; Teufel, L.W. [Sandia National Labs., Albuquerque, NM (United States); Aslakson, J.K.

    1994-12-31

    This reference paper reviews and describes 15 techniques for determining hydraulic fracture azimuth. The techniques described are categorized into core-based, borehole-based, near-wellbore, and regional geologic indicators that can be used to predict or measure hydraulic fracture azimuth. The core based methods include: (1) circumferential velocity anisotropy, (2) anelastic strain recovery, (3) differential strain curve analysis, (4) axial point load tests, (5) petrographic examination of microcracks, (6) overcoming of archived core, (7) drilling-induced fractures in core, and (8) direct observation of over-cored open-hole stress test fractures. The borehole based techniques include: (9) borehole breakouts, (10) borehole deformation, (11) borehole imaging of drilling induced fractures, and (12) directional gamma ray logging. The near-wellbore techniques provided data on the orientation of the fracture induced during an actual fracture treatment and include: (13) microseismic logging and (14) earth tilt surveys. Finally there are the geologic indicators (Method 15) including earthquake focal mechanisms, fault slip data, surface mapping of neotectonic joints, and volcanic vent alignment. These regional data have been compiled for the World Stress Mapping Project and many maps are available that can be used as a first approximation of stress direction. Experience has shown that the more techniques that can be used in a single well or field, the more reliable the result. The concept or theoretical basis for each technique as well as the benefits and limitations of the techniques are described.

  3. Experimental Study on the Anisotropic Stress-Strain Behavior of Polycrystalline Ni-Mn-Ga in Directional Solidification

    Science.gov (United States)

    Teng, Yao; Shi, Tao; Zhu, Yuping; Li, Zongbin; Deng, Tao; Bai, Guonan

    2016-03-01

    A polycrystalline Ni-Mn-Ga ferromagnetic shape memory alloy produced by directional solidification is the subject of this research paper. The compressive stress-strain curves of the material for different cutting angles to the solidification direction are tested. The martensite Young's modulus, macroscopic reorientation strain, and phase transition critical stress are analyzed experimentally. The results show that mechanical behaviors in the loading-unloading cycle of the material present nonlinear and anisotropic characteristics, which are all closely related to the material's orientation to the solidification direction. The martensite Young's modulus, macroscopic reorientation strain, and phase transition critical stress achieve maximum values in the solidification direction. A 50° orientation to the solidification direction is the cut-off direction of the mechanical properties, where the martensite Young's modulus and reorientation start critical stress reach minimum values. The present study is expected to provide sound guidance for practical applications.

  4. Stress Related Fracturing in Dimension Stone Quarries

    Science.gov (United States)

    Hamdi Deliormanli, Ahmet; Maerz, Norbert H.

    2016-10-01

    In Missouri, the horizontal stresses (pressures) in the near surface rock are uncommonly high. While the vertical stresses in rock are simply a function of the weight of the overlying rock, near surface stresses can be many times higher. The near surface horizontal stresses can be in excess of 5 times greater than the vertical stresses. In this research, Flatjack method was used to measure horizontal stress in Red Granite Quarry in Missouri. The flat jack method is an approved method of measuring ground stresses. A saw cut is used to “relax” the stress in the ground by allowing the rock to deform inwards the cut. A hydraulic flat jack is used to inflate the slot; to push the rock back to its stressed position, as measured by a strain gauge on either side of the slot. The pressure in the jack, when the rock is exactly back to its original position, is equal to the ground stress before the saw cut was made. According to the results, present production direction for each pit is not good because the maximum stress direction is perpendicular with production direction. This case causes unintentional breakage results in the loss rock. The results show that production direction should be changed.

  5. Directed Forgetting in Post-Traumatic-Stress-Disorder: A study of refugee immigrants in Germany

    Directory of Open Access Journals (Sweden)

    Michaela eBaumann

    2013-08-01

    Full Text Available People with post-traumatic stress disorder (PTSD often suffer from memory disturbances. In particular, previous studies suggest that PTSD patients perform atypically on tests of directed forgetting, which may be mediated by an altered emotional appraisal of the presented material. Also, a special role of dissociative symptoms in traumatized individuals’ memory performance has been suggested. Here, we investigate these issues in traumatized immigrants in Germany. In an item-method directed forgetting task, pictures were presented individually, each followed by an instruction to either remember or forget it. Later, recognition memory was tested for all pictures, regardless of initial instruction. Overall, the PTSD group’s discrimination accuracy was lower than the control group’s, as PTSD participants produced fewer hits and more false alarms, but the groups did not differ in directed forgetting itself. Moreover, the more negatively participants evaluated the stimuli, the less they were able to discriminate old from new items. Participants with higher dissociation scores were particularly poor at recognizing to-be-forgotten items. Results confirm PTSD patients’ general discrimination deficits, but provide no evidence for a distinct directed forgetting pattern in PTSD. Furthermore, data indicate that, in general, more negatively perceived items are discriminated with less accuracy than more positively appraised ones. Results are discussed in the larger context of emotion and stress-related modulations of episodic memory, with particular focus on the role of dissociative symptoms.

  6. Direct Shear Tests of Sandstone Under Constant Normal Tensile Stress Condition Using a Simple Auxiliary Device

    Science.gov (United States)

    Cen, Duofeng; Huang, Da

    2017-06-01

    Tension-shear failure is a typical failure mode in the rock masses in unloading zones induced by excavation or river incision, etc., such as in excavation-disturbed zone of deep underground caverns and superficial rocks of high steep slopes. However, almost all the current shear failure criteria for rock are usually derived on the basis of compression-shear failure. This paper proposes a simple device for use with a servo-controlled compression-shear testing machine to conduct the tension-shear tests of cuboid rock specimens, to test the direct shear behavior of sandstone under different constant normal tensile stress conditions ( σ = -1, -1.5, -2, -2.5 and -3 MPa) as well as the uniaxial tension behavior. Generally, the fracture surface roughness decreases and the proportion of comminution areas in fracture surface increases as the change of stress state from tension to tension-shear and to compression-shear. Stepped fracture is a primary fracture pattern in the tension-shear tests. The shear stiffness, shear deformation and normal deformation (except the normal deformation for σ = -1 MPa) decrease during shearing, while the total normal deformation containing the pre-shearing portion increases as the normal tensile stress level (| σ|) goes up. Shear strength is more sensitive to the normal tensile stress than to the normal compressive stress, and the power function failure criterion (or Mohr envelope form of Hoek-Brown criterion) is examined to be the optimal criterion for the tested sandstone in the full region of tested normal stress in this study.

  7. Effects Of The Direct Renin Inhibitor Aliskiren On Oxidative Stress In Isolated Rat Heart

    Directory of Open Access Journals (Sweden)

    Plecevic Sasa

    2015-09-01

    Full Text Available Increased activity of the renin-angiotensin-aldosterone system (RAAS plays a significant role in the development and progression of various cardio-metabolic diseases, such as hypertension, atherosclerosis and heart failure. Aliskiren is the newest antihypertensive drug and the first orally active direct renin inhibitor to become available for clinical use. This study investigated the acute and direct effects of Aliskiren on different parameters of oxidative stress on isolated rat heart. The hearts of male Wistar albino rats (n = 24, 8 per experimental group, age 8 weeks, body mass 180–200 g, were excised and retrogradely perfused according to the Langendorfftechnique at a gradually increasing perfusion pressure (40-120 cmH2O. Markers of oxidative stress (NO2−, TBARS, H2O2 and O2− were measured spectrophotometrically after perfusion with three different concentrations of Aliskiren (0.1 μM, 1 μM, and 10 μM. The results demonstrated possible dose-dependent cardioprotective properties of Aliskiren, particularly with higher CPP. Lipid peroxidation (TBARS levels decreased with the highest dose of Aliskiren and higher CPP, and the same trend was observed in nitrite (NO2− and hydrogen peroxide (H2O2 levels. These findings indicate that the acute effects of Aliskiren do not likely promote the production of reactive oxygen species upon higher pressure with the highest dose. Aliskiren may exert beneficial effects on oxidative stress biomarkers.

  8. Nanoscale tensile stress approach for the direct writing of plasmonic nanostructures.

    Science.gov (United States)

    Zhai, Tianrui; Lin, Yuanhai; Liu, Hongmei; Feng, Shengfei; Zhang, Xinping

    2013-10-21

    One- and two-dimensional plasmonic nanostructures can be fabricated using nanoscale tensile stress. A polymer layer, coated with a thin metal film, is exposed to an interference pattern produced by ultraviolet laser beams. Crosslinking is induced between the polymeric molecules located within the bright fringes. This process not only increases the refractive index but also reduces the polymer layer thickness. Corrugations occur on the continuous thin metal film due to the nanoscale stress in the polymer layer. Thus, a periodic nanostructure of area 3 × 3 mm and depth 50 nm is created both in the polymer and metal films with excellent homogeneity and reproducibility. This method enables direct writing of a large-area plasmonic nanostructure at low cost which can be used in the design of optoelectronic devices and sensors.

  9. DNA Damage Response Pathway and Replication Fork Stress During Oligonucleotide Directed Gene Editing

    Directory of Open Access Journals (Sweden)

    Melissa Bonner

    2012-01-01

    Full Text Available Single-stranded DNA oligonucleotides (ODNs can be used to direct the exchange of nucleotides in the genome of mammalian cells in a process known as gene editing. Once refined, gene editing should become a viable option for gene therapy and molecular medicine. Gene editing is regulated by a number of DNA recombination and repair pathways whose natural activities often lead to single- and double-stranded DNA breaks. It has been previously shown that introduction of a phosphorotioated ODN, designed to direct a gene-editing event, into cells results in the activation of γH2AX, a well-recognized protein biomarker for double-stranded DNA breakage. Using a single copy, integrated mutant enhanced green fluorescent protein (eGFP gene as our target, we now demonstrate that several types of ODNs, capable of directing gene editing, also activate the DNA damage response and the post-translational modification of proliferating cell nuclear antigen (PCNA, a signature modification of replication stress. We find that the gene editing reaction itself leads to transient DNA breakage, perhaps through replication fork collapse. Unmodified specific ODNs elicit a lesser degree of replication stress than their chemically modified counterparts, but are also less active in gene editing. Modified phosphothioate oligonucleotides (PTOs are detrimental irrespective of the DNA sequence. Such collateral damage may prove problematic for proliferation of human cells genetically modified by gene editing.

  10. Effects of psychosocial stress on the goal-directed and habit memory systems during learning and later execution.

    Science.gov (United States)

    Fournier, Marion; d'Arripe-Longueville, Fabienne; Radel, Rémi

    2017-03-01

    Instrumental learning occurs through both goal-directed and habit memory systems, which are supported by anatomically distinct brain systems. Interestingly, stress may promote habits at the expense of goal-directed performance, since stress before training in an instrumental task was found to cause individuals to carry on with the learned association in spite of a devalued outcome. These findings nevertheless left pending questions, and it has been difficult to determine which system is primarily affected by stress (an improved habit system, an impaired goal-directed system, or both) and at what point the stress acts (at the moment of learning by making more resistant habits, or after devaluation by making individuals less sensitive to change in the outcome value). The present study (N=72 participants, 63 males and 9 females) aimed to answer these questions with (i) an instrumental task that dissociates the two memory systems and (ii) three conditions of psychosocial stress exposure (Trier Social Stress Test): stress induced before learning, before devaluation, and not induced for the control group. The study confirms that exposure to psychosocial stress leads to habitual performance. Moreover, it provides new insight into this effect by locating its origin as an impairment in the capacity of the goal-directed system rather than a reinforcement in habit learning. These results are discussed in light of recent neurobiological models of stress and memory. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Satellite-Based All-Sky and Clear-Sky Direct Normal Irradiance: Application of a Global-to-Beam Model to the NASA GEWEX SRB Global Horizontal Irradiance and Validation against the BSRN Data

    Science.gov (United States)

    Zhang, T.; Stackhouse, P. W., Jr.; Westberg, D. J.

    2016-12-01

    The NASA GEWEX SRB Release 3.0 provides, among other things, surface downwelling solar irradiance, or global horizontal irradiance (GHI), on a global grid system of 1 degree latitude by 1 degree longitude. The dataset spans a 24.5-year period at 3-hourly temporal resolution from July 1983 to December 2007. The 3-hourly GHIs and daily and monthly means derived therefrom have been extensively validated against surface-based observations from the Baseline Surface Radiation Network (BSRN), the Pacific Marine Environmental Laboratory (PMEL), the World Radiation Data Centre (WRDC), and the Global Energy Balance Archive (GEBA). The DIRINDEX model is an empirical global-to-beam model which derives hourly direct normal irradiances (DNIs) from GHIs. We have applied this model to the GEWEX SRB Release 3.0 3-hourly GHIs and derived a set of DNIs at the same spatiotemporal resolution and time span. The model input includes both all-sky and clear-sky GHIs. Additional inputs include the Modern-Era Retrospective Analysis for Research and Applications (MERRA) atmospheric data and the Max-Planck Aerosol Climatology Version 1 (MAC-v1). The output DNIs are for both all-sky and clear-sky conditions as well. The all-sky 3-hourly, daily and monthly DNIs have been validated against their BSRN counterparts and good agreement has been achieved. The clear-sky DNIs were initially not in as good agreement with their BSRN counterparts. Based on the comparison statistics, we corrected the parameters of the DIRINDEX model relevant to the clear-sky DNIs and improved the output clear-sky DNIs. In this presentation, we show how the DNIs were derived and how they compare with the BSRN data. Intercomparison of the derived direct horizontal irradiance with that of the Clouds and the Earth's Radiant Energy System (CERES) will also be presented.

  12. Combining stress transfer and source directivity: the case of the 2012 Emilia seismic sequence.

    Science.gov (United States)

    Convertito, Vincenzo; Catalli, Flaminia; Emolo, Antonio

    2013-11-01

    The Emilia seismic sequence (Northern Italy) started on May 2012 and caused 17 casualties, severe damage to dwellings and forced the closure of several factories. The total number of events recorded in one month was about 2100, with local magnitude ranging between 1.0 and 5.9. We investigate potential mechanisms (static and dynamic triggering) that may describe the evolution of the sequence. We consider rupture directivity in the dynamic strain field and observe that, for each main earthquake, its aftershocks and the subsequent large event occurred in an area characterized by higher dynamic strains and corresponding to the dominant rupture direction. We find that static stress redistribution alone is not capable of explaining the locations of subsequent events. We conclude that dynamic triggering played a significant role in driving the sequence. This triggering was also associated with a variation in permeability and a pore pressure increase in an area characterized by a massive presence of fluids.

  13. Combining stress transfer and source directivity: the case of the 2012 Emilia seismic sequence

    Science.gov (United States)

    Convertito, Vincenzo; Catalli, Flaminia; Emolo, Antonio

    2013-11-01

    The Emilia seismic sequence (Northern Italy) started on May 2012 and caused 17 casualties, severe damage to dwellings and forced the closure of several factories. The total number of events recorded in one month was about 2100, with local magnitude ranging between 1.0 and 5.9. We investigate potential mechanisms (static and dynamic triggering) that may describe the evolution of the sequence. We consider rupture directivity in the dynamic strain field and observe that, for each main earthquake, its aftershocks and the subsequent large event occurred in an area characterized by higher dynamic strains and corresponding to the dominant rupture direction. We find that static stress redistribution alone is not capable of explaining the locations of subsequent events. We conclude that dynamic triggering played a significant role in driving the sequence. This triggering was also associated with a variation in permeability and a pore pressure increase in an area characterized by a massive presence of fluids.

  14. Do infants have the horizontal bias?

    Science.gov (United States)

    Van Renswoude, D R; Johnson, S P; Raijmakers, M E J; Visser, I

    2016-08-01

    A robust set of studies show that adults make more horizontal than vertical and oblique saccades, while scanning real-world scenes. In this paper we study the horizontal bias in infants. The directions of eye movements were calculated for 41 infants (M=8.40 months, SD=3.74, range=3.48-15.47) and 47 adults (M=21.74 years, SD=4.54, range=17.89-39.84) while viewing 28 real-world scenes. Saccade directions were binned to study the proportion of saccades in the horizontal, vertical and oblique directions. In addition, saccade directions were also modeled using a mixture of Von Mises distributions, to account for the relatively large amount of variance in infants data. Horizontal bias was replicated in adults and also found in infants, using both the binning and Von Mises approach. Moreover, a developmental pattern was observed in which older infants are more precise in targeting their saccades than younger infants. That infants have a horizontal bias is important in understanding infants' eye movements. Future studies should account for the horizontal bias in their designs and analyses. Copyright © 2016 Elsevier Inc. All rights reserved.

  15. Sensor for Direct Measurement of the Boundary Shear Stress in Fluid Flow

    Science.gov (United States)

    Bao, Xiaoqi; Badescu, Mircea; Bar-Cohen, Yoseph; Lih, Shyh-Shiuh; Sherrit, Stewart; Chang, Zensheu; Chen, Beck; Widholm, Scott; Ostlund, Patrick

    2011-01-01

    The formation of scour patterns at bridge piers is driven by the forces at the boundary of the water flow. In most experimental scour studies, indirect processes have been applied to estimate the shear and normal stress using measured velocity profiles. The estimations are based on theoretical models and associated assumptions. However, the turbulence flow fields and boundary layer in the pier-scour region are very complex. In addition, available turbulence models cannot account accurately for the bed roughness effect. Direct measurement of the boundary shear and normal stress and their fluctuations are attractive alternatives. However, this approach is a challenging one especially for high spatial resolution and high fidelity measurements. The authors designed and fabricated a prototype miniature shear stress sensor including an EDM machined floating plate and a high-resolution laser optical encoder. Tests were performed both in air as well as operation in water with controlled flow. The sensor sensitivity, stability and signal-to-noise level were measured and evaluated. The detailed test results and a discussion of future work will be presented in this paper.

  16. Work Stress and Depression among Direct Support Professionals: The Role of Work Support and Locus of Control

    Science.gov (United States)

    Gray-Stanley, J. A.; Muramatsu, N.; Heller, T.; Hughes, S.; Johnson, T. P.; Ramirez-Valles, J.

    2010-01-01

    Background: Although work stress can impede the capacity of direct support professionals and contribute to mental health challenges, external (i.e. work social support) and internal resources (i.e. an internal locus of control) have been shown to help DSPs cope more actively. We examined how work stress was associated with depression, with a…

  17. High-resolution compact shear stress sensor for direct measurement of skin friction in fluid flow

    Science.gov (United States)

    Xu, Muchen; Kim, Chang-Jin ``Cj''

    2015-11-01

    The high-resolution measurement of skin friction in complex flows has long been of great interest but also a challenge in fluid mechanics. Compared with indirect measurement methods (e.g., laser Doppler velocimetry), direct measurement methods (e.g., floating element) do not involve any analogy and assumption but tend to suffer from instrumentation challenges, such as low sensing resolution or misalignments. Recently, silicon micromachined floating plates showed good resolution and perfect alignment but were too small for general purposes and too fragile to attach other surface samples repeatedly. In this work, we report a skin friction sensor consisting of a monolithic floating plate and a high-resolution optical encoder to measure its displacement. The key for the high resolution is in the suspension beams, which are very narrow (e.g., 0.25 mm) to sense small frictions along the flow direction but thick (e.g., 5 mm) to be robust along all other directions. This compact, low profile, and complete sensor is easy to use and allows repeated attachment and detachment of surface samples. The sheer-stress sensor has been tested in water tunnel and towing tank at different flow conditions, showing high sensing resolution for skin friction measurement. Supported by National Science Foundation (NSF) (No. 1336966) and Defense Advanced Research Projects Agency (DARPA) (No. HR0011-15-2-0021).

  18. ALSPEN: a mathematical model for thermal stresses in direct chill casting of aluminium billets

    Directory of Open Access Journals (Sweden)

    Hallvard G. Fjær

    1993-10-01

    Full Text Available This paper presents the mathematical model ALSPEN, in which the thermally induced strains and stresses which develop during direct chill (DC semicontinuous casting of aluminium billets are calculated by a finite-element method. The metal is assumed to be an isotropic elastic-viscoplastic material with strongly temperature-dependent properties. In the material description, the viscoplastic strain is treated in a 'unified' manner, in which low-temperature (approximately time-independent plasticity and creep at high temperatures occur as special cases. Furthermore, in the numerical time stepping procedure, all of these plastic material properties which are present simultaneously in the solution domain as a result of the large temperature differences, are treated in a similar way. To demonstrate some of the capabilities of ALSPEN, we have modeled the casting of an AlMgSi alloy, AA6063. The material properties of this alloy have been studied in parallel with the development of the mathematical model.

  19. Repeated Thermal Stress, Shading, and Directional Selection in the Florida Reef Tract

    Directory of Open Access Journals (Sweden)

    Robert van Woesik

    2017-06-01

    Full Text Available Over the last three decades reef corals have been subjected to an unprecedented frequency and intensity of thermal-stress events, which have led to extensive coral bleaching, disease, and mortality. Over the next century, the climate is predicted to drive sea-surface temperatures to even higher levels, consequently increasing the risk of mass bleaching and disease outbreaks. Yet, there is considerable temporal and spatial variation in coral bleaching and in disease prevalence. Using data collected from 2,398 sites along the Florida reef tract from 2005 to 2015, this study examined the temporal and spatial patterns of coral bleaching and disease in relation to coral-colony size, depth, temperature, and chlorophyll-a concentrations. The results show that coral bleaching was most prevalent during the warmest years in 2014 and 2015, and disease was also most prevalent in 2010, 2014, and 2015. Although the majority of the corals surveyed were found in habitats with low chlorophyll-a concentrations, and high irradiance, these same habitats showed the highest prevalence of coral bleaching and disease outbreaks during thermal-stress events. These results suggest that directional selection in a warming ocean may favor corals able to tolerate inshore, shaded environments with high turbidity and productivity.

  20. IRF8 directs stress induced autophagy in macrophages and promotes clearance of Listeria monocytogenes

    Science.gov (United States)

    Gupta, Monica; Shin, Dong-Mi; Ramakrishna, Lakshmi; Goussetis, Dennis J.; Platanias, Leonidas C.; Xiong, Huabao; Morse, Herbert C.; Ozato, Keiko

    2015-01-01

    Autophagy, activated by many stresses, plays a critical role in innate immune responses. Here we show that Interferon Regulatory Factor 8 (IRF8) is required for expression of autophagy-related genes in dendritic cells. Furthermore in macrophages, IRF8 is induced by multiple autophagy-inducing stresses, including IFNγ and toll like receptor stimulation, bacterial infection, starvation and by macrophage colony-stimulating factor. IRF8 directly activates many genes involved in various steps of autophagy, promoting autophagosome formation and lysosomal fusion. Consequently, Irf8-/- macrophages are deficient in autophagic activity, and excessively accumulate SQSTM1 and ubiquitin-bound proteins. We show that clearance of Listeria monocytogenes in macrophages requires IRF8-dependent activation of autophagy genes and subsequent autophagic capturing and degradation of Listeria antigens. These processes are defective in Irf8-/- macrophages where uninhibited bacterial growth ensues. Together, these data suggest that IRF8 is a major autophagy regulator in macrophages, essential for macrophage maturation, survival and innate immune responses. PMID:25775030

  1. Earthquake Directivity, Orientation, and Stress Drop Within the Subducting Plate at the Hikurangi Margin, New Zealand

    Science.gov (United States)

    Abercrombie, Rachel E.; Poli, Piero; Bannister, Stephen

    2017-12-01

    We develop an approach to calculate earthquake source directivity and rupture velocity for small earthquakes, using the whole source time function rather than just an estimate of the duration. We apply the method to an aftershock sequence within the subducting plate beneath North Island, New Zealand, and investigate its resolution. We use closely located, highly correlated empirical Green's function (EGF) events to obtain source time functions (STFs) for this well-recorded sequence. We stack the STFs from multiple EGFs at each station, to improve the stability of the STFs. Eleven earthquakes (M 3.3-4.5) have sufficient azimuthal coverage, and both P and S STFs, to investigate directivity. The time axis of each STF in turn is stretched to find the maximum correlation between all pairs of stations. We then invert for the orientation and rupture velocity of both unilateral and bilateral line sources that best match the observations. We determine whether they are distinguishable and investigate the effects of limited frequency bandwidth. Rupture orientations are resolvable for eight earthquakes, seven of which are predominantly unilateral, and all are consistent with rupture on planes similar to the main shock fault plane. Purely unilateral rupture is rarely distinguishable from asymmetric bilateral rupture, despite a good station distribution. Synthetic testing shows that rupture velocity is the least well-resolved parameter; estimates decrease with loss of high-frequency energy, and measurements are best considered minimum values. We see no correlation between rupture velocity and stress drop, and spatial stress drop variation cannot be explained as an artifact of varying rupture velocity.

  2. Putrescine production via the ornithine decarboxylation pathway improves the acid stress survival of Lactobacillus brevis and is part of a horizontally transferred acid resistance locus.

    Science.gov (United States)

    Romano, Andrea; Ladero, Victor; Alvarez, Miguel A; Lucas, Patrick M

    2014-04-03

    Decarboxylation pathways are widespread among lactic acid bacteria; their physiological role is related to acid resistance through the regulation of the intracellular pH and to the production of metabolic energy via the generation of a proton motive force and its conversion into ATP. These pathways include, among others, biogenic amine (BA) production pathways. BA accumulation in foodstuffs is a health risk; thus, the study of the factors involved in their production is of major concern. The analysis of several lactic acid bacterial strains isolated from different environments, including fermented foods and beverages, revealed that the genes encoding these pathways are clustered on the chromosome, which suggests that these genes are part of a genetic hotspot related to acid stress resistance. Further attention was devoted to the ornithine decarboxylase pathway, which affords putrescine from ornithine. Studies were performed on three lactic acid bacteria belonging to different species. The ODC pathway was always shown to be involved in cytosolic pH alkalinisation and acid shock survival, which were observed to occur with a concomitant increase in putrescine production. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. Stope Stability Assessment and Effect of Horizontal to Vertical Stress Ratio on the Yielding and Relaxation Zones Around Underground Open Stopes Using Empirical and Finite Element Methods

    Science.gov (United States)

    Sepehri, Mohammadali; Apel, Derek; Liu, Wei

    2017-09-01

    Predicting the stability of open stopes can be a challenging task for underground mine engineers. For decades, the stability graph method has been used as the first step of open stope design around the world. However, there are some shortcomings with this method. For instance, the stability graph method does not account for the relaxation zones around the stopes. Another limitation of the stability graph is that this method cannot to be used to evaluate the stability of the stopes with high walls made of backfill materials. However, there are several analytical and numerical methods that can be used to overcome these limitations. In this study, both empirical and numerical methods have been used to assess the stability of an open stope located between mine levels N9225 and N9250 at Diavik diamond underground mine. It was shown that the numerical methods can be used as complementary methods along with other analytical and empirical methods to assess the stability of open stopes. A three dimensional elastoplastic finite element model was constructed using Abaqus software. In this paper a sensitivity analysis was performed to investigate the impact of the stress ratio "k" on the extent of the yielding and relaxation zones around the hangingwall and footwall of the understudy stope.

  4. Stress perturbation associated with the Amazonas and other ancient continental rifts

    Science.gov (United States)

    Zoback, M.L.; Richardson, R.M.

    1996-01-01

    The state of stress in the vicinity of old continental rifts is examined to investigate the possibility that crustal structure associated with ancient rifts (specifically a dense rift pillow in the lower crust) may modify substantially the regional stress field. Both shallow (2.0-2.6 km depth) breakout data and deep (20-45 km depth) crustal earthquake focal mechanisms indicate a N to NNE maximum horizontal compression in the vicinity of the Paleozoic Amazonas rift in central Brazil. This compressive stress direction is nearly perpendicular to the rift structure and represents a ???75?? rotation relative to a regional E-W compressive stress direction in the South American plate. Elastic two-dimensional finite element models of the density structure associated with the Amazonas rift (as inferred from independent gravity modeling) indicate that elastic support of this dense feature would generate horizontal rift-normal compressional stresses between 60 and 120 MPa, with values of 80-100 MPa probably most representative of the overall structure. The observed ???75?? stress rotation constrains the ratio of the regional horizontal stress difference to the rift-normal compressive stress to be between 0.25 and 1.0, suggesting that this rift-normal stress may be from 1 to 4 times larger than the regional horizontal stress difference. A general expression for the modification of the normalized local horizontal shear stress (relative to the regional horizontal shear stress) shows that the same ratio of the rift-normal compression relative to the regional horizontal stress difference, which controls the amount of stress rotation, also determines whether the superposed stress increases or decreases the local maximum horizontal shear stress. The potential for fault reactivation of ancient continental rifts in general is analyzed considering both the local stress rotation and modification of horizontal shear stress for both thrust and strike-slip stress regimes. In the Amazonas

  5. Direct and Indirect Effects of Five Factor Personality and Gender on Depressive Symptoms Mediated by Perceived Stress.

    Science.gov (United States)

    Kim, Song E; Kim, Han-Na; Cho, Juhee; Kwon, Min-Jung; Chang, Yoosoo; Ryu, Seungho; Shin, Hocheol; Kim, Hyung-Lae

    2016-01-01

    This study was designed to investigate associations among five factor personality traits, perceived stress, and depressive symptoms and to examine the roles of personality and perceived stress in the relationship between gender and depressive symptoms. The participants (N = 3,950) were part of a cohort study for health screening and examination at the Kangbuk Samsung Hospital. Personality was measured with the Revised NEO Personality Inventory (NEO-PI-R). Depressive symptoms were assessed using the Center for Epidemiologic Studies Depression Scale (CES-D). Perceived stress level was evaluated with a self-reported stress questionnaire developed for the Korea National Health and Nutrition Examination Survey. A higher degree of neuroticism and lower degrees of extraversion, agreeableness, and conscientiousness were significantly associated with greater perceived stress and depressive symptoms. Neuroticism and extraversion had significant direct and indirect effects (via stress as a mediator) on depressive symptoms in both genders. Agreeableness and conscientiousness had indirect effects on depression symptoms in both genders. Multiple mediation models were used to examine the mediational roles of each personality factor and perceived stress in the link between gender and depressive symptoms. Four of the personality factors (except openness) were significant mediators, along with stress, on the relationship between gender and depressive symptoms. Our findings suggest that the links between personality factors and depressive symptoms are mediated by perceived stress. As such, personality is an important factor to consider when examining the link between gender and depression.

  6. Direct and Indirect Effects of Five Factor Personality and Gender on Depressive Symptoms Mediated by Perceived Stress.

    Directory of Open Access Journals (Sweden)

    Song E Kim

    Full Text Available This study was designed to investigate associations among five factor personality traits, perceived stress, and depressive symptoms and to examine the roles of personality and perceived stress in the relationship between gender and depressive symptoms. The participants (N = 3,950 were part of a cohort study for health screening and examination at the Kangbuk Samsung Hospital. Personality was measured with the Revised NEO Personality Inventory (NEO-PI-R. Depressive symptoms were assessed using the Center for Epidemiologic Studies Depression Scale (CES-D. Perceived stress level was evaluated with a self-reported stress questionnaire developed for the Korea National Health and Nutrition Examination Survey. A higher degree of neuroticism and lower degrees of extraversion, agreeableness, and conscientiousness were significantly associated with greater perceived stress and depressive symptoms. Neuroticism and extraversion had significant direct and indirect effects (via stress as a mediator on depressive symptoms in both genders. Agreeableness and conscientiousness had indirect effects on depression symptoms in both genders. Multiple mediation models were used to examine the mediational roles of each personality factor and perceived stress in the link between gender and depressive symptoms. Four of the personality factors (except openness were significant mediators, along with stress, on the relationship between gender and depressive symptoms. Our findings suggest that the links between personality factors and depressive symptoms are mediated by perceived stress. As such, personality is an important factor to consider when examining the link between gender and depression.

  7. Belo Horizonte em recortes

    Directory of Open Access Journals (Sweden)

    Ivete Lara Camargos Walty

    1998-03-01

    Full Text Available A partir do conceito de rizoma de Deleuze e Guatari, faz-se uma montagem de trechos de textos literários sobre Belo Horizonte, intercalados com extratos do livro As cidades invisíveis, de Italo Calvino, como objetivo de se esboçar faces/retratos da cidade.

  8. Horizontal violence in Nursing

    Directory of Open Access Journals (Sweden)

    Tsimoulaki Evangelia

    2017-01-01

    Full Text Available One’s effort to clarify the definition of horizontal labour violence is of great importance, due to the variety of definitions that are mentioned in the worldwide scientific literature. Furthermore, the reference of multiple forms of such violence herein the nurse professional group is challenging, as well. Another fact of great importance is that, any form of professional violence (horizontal violence, horizontal mobbing in the work place environment can be possibly escalated and include even physical abuse (Bullying, besides the psychological and emotional impact for the victim. The definitions of Horizontal violence, Mobbing and Bullying, include a repeated negative behaviour emanating from at least one “predator” towards at least one “victim”, with work status differences and the existence or lack of physical abuse (Bullying. Horizontal violence is a hostile, aggressive and harmful behaviour which is either overt or concealed and is pointed from an individual to another individual of the same working rank and causes intense emotional pain at the victim. The manifestations vary from humiliating tasks assignment or the victim’s efforts undermining to clearly aggressive behaviors (criticism, intimidation, sarcasm etc.. The reason behind this phenomenon is multifactorial extended not only towards the working environment but also to the personal characteristics of the “predator” as well as the possible “victim”. The researchers emphasize the high incidence of the phenomenon, as well as the cost that is induced by the violent behaviors to both the health professionals and the hospital. Finally, they point out the paradox of the presence of violence inside a system that is designed to promote health.

  9. Determining the delamination propensity of pharmaceutical glass vials using a direct stress method.

    Science.gov (United States)

    Sloey, Christopher; Gleason, Camille; Phillips, Joseph

    2013-01-01

    An accelerated lamellae formation (ALF) methodology has been developed to determine the delamination propensity and susceptibility of pharmaceutical glass vials. The ALF process consists of a vial wash and depyrogenation mimic procedure followed by stressing glass vials with 20 mM glycine pH 10.0 solution at 50 °C for 24 h and analyzing the resulting solutions by visual inspection for glass lamellae. ALF results demonstrate that while vial delamination propensity generally correlates with glass hydrolytic resistance, ALF is a more direct test of glass delamination propensity and is not affected by post-production vial washing that can affect results obtained using hydrolytic resistance tests. ALF can potentially be used by pharmaceutical companies to evaluate and screen incoming vial lots to minimize the risk of delamination during the shelf life of parenteral therapeutics, and by glass vial manufacturers to monitor and improve their vial manufacturing processes. Glass flakes can sometimes appear in liquid pharmaceutical drugs contained in glass vials. These glass flakes are a result of several factors related to the glass vial production process, glass vial sterilization procedures, and the formulation of the liquid pharmaceutical drug. Vial testing is routinely done in order to select glass vials that are less likely to form glass flakes. The factors leading to the formation of glass flakes were studied and applied to a method designed to directly screen vials for their propensity to form glass flakes. The washing of vials followed immediately by sterilization at high temperatures was determined to be a critical factor in the formation of glass flakes. As a result, a laboratory mimic of this procedure was incorporated into the newly developed method for screening vials. This mimic procedure as well as robust accelerated incubation conditions and a sensitive visual inspection procedure are key aspects of this vial screening method.

  10. RNA recognition motif 2 directs the recruitment of SF2/ASF to nuclear stress bodies.

    Science.gov (United States)

    Chiodi, Ilaria; Corioni, Margherita; Giordano, Manuela; Valgardsdottir, Rut; Ghigna, Claudia; Cobianchi, Fabio; Xu, Rui-Ming; Riva, Silvano; Biamonti, Giuseppe

    2004-01-01

    Heat shock induces the transcriptional activation of large heterochromatic regions of the human genome composed of arrays of satellite III DNA repeats. A number of RNA-processing factors, among them splicing factor SF2/ASF, associate with these transcription factors giving rise to nuclear stress bodies (nSBs). Here, we show that the recruitment of SF2/ASF to these structures is mediated by its second RNA recognition motif. Amino acid substitutions in the first alpha-helix of this domain, but not in the beta-strand regions, abrogate the association with nSBs. The same mutations drastically affect the in vivo activity of SF2/ASF in the alternative splicing of adenoviral E1A transcripts. Sequence analysis identifies four putative high-affinity binding sites for SF2/ASF in the transcribed strand of the satellite III DNA. We have verified by gel mobility shift assays that the second RNA-binding domain of SF2/ASF binds at least one of these sites. Our analysis suggests that the recruitment of SF2/ASF to nSBs is mediated by a direct interaction with satellite III transcripts and points to the second RNA-binding domain of the protein as the major determinant of this interaction.

  11. Longevity of direct restorations in stress-bearing posterior cavities: a retrospective study.

    Science.gov (United States)

    Rho, Y-J; Namgung, C; Jin, B-H; Lim, B-S; Cho, B-H

    2013-01-01

    The aims of this retrospective clinical study were to compare the longevities of direct posterior amalgam restorations (AMs) and resin composite restorations (RCs) that were subjected to occlusal stresses and to investigate variables predictive of their outcome. A total of 269 AMs and RCs filled in Class I and II cavities of posterior teeth were evaluated with Kaplan-Meier survival estimator and multivariate Cox proportional hazard model. Seventy-one retreated restorations were reviewed from dental records. The other 198 restorations still in use were evaluated according to modified US Public Health Service (USPHS) criteria by two investigators. The longevity of RCs was significantly lower than that of AMs (AM = 8.7 years and RC = 5.0 years, page, restorative material, tooth type, operator group, diagnosis, cavity classification, and gender, affected the longevity of the restorations (multivariate Cox regression analysis, phappens in a rapid progression. As posterior esthetic restorations, RCs must be observed carefully with periodic follow-ups for early detection and timely repair of failures.

  12. The flavanol (-)-epicatechin and its metabolites protect against oxidative stress in primary endothelial cells via a direct antioxidant effect.

    Science.gov (United States)

    Ruijters, Erik J B; Weseler, Antje R; Kicken, Cécile; Haenen, Guido R M M; Bast, Aalt

    2013-09-05

    Accumulating evidence suggests that foods rich in flavanols decrease the risk of developing cardiovascular diseases. Attenuation of oxidative stress was suggested to contribute to the cardiovascular benefit of flavanols. Up to now it was unclear whether flavanol metabolites can also protect cells from oxidative stress. The aim of the present study was to determine the potential contribution of several glucuronidated, methylated and sulfated metabolites of (-)-epicatechin (EC) and (+)-catechin (Cat) to the protection of human vascular endothelial cells (HUVECs) against oxidative stress. The relative potency of the tested compounds to scavenge superoxide anion radicals showed that a free catechol moiety in the molecule is important for the direct antioxidant activity. EC and Cat (0.5, 1, 10µM) were potent radical scavengers and provided protection against intracellular oxidative stress induced by hydrogen peroxide. Although the metabolites provided less intracellular protection compared to EC and Cat, the tested methylated and glucuronidated metabolites reduced oxidative stress significantly in HUVECs. Our results indicate that the metabolites have a relevant contribution in the intracellular protection of EC and Cat against oxidative stress. Also, the direct antioxidant activity plays an important role in this protection. © 2013 Elsevier B.V. All rights reserved.

  13. Teaching Activities on Horizontal Nuclear Proliferation.

    Science.gov (United States)

    Zola, John

    1990-01-01

    Provides learning activities concerning the horizontal proliferation of nuclear weapons. Includes step-by-step directions for four activities: (1) the life cycle of nuclear weapons; (2) nuclear nonproliferation: pros and cons; (3) the nuclear power/nuclear weapons connection; and (4) managing nuclear proliferation. (NL)

  14. Effects of Motivation, Academic Stress and Age in Predicting Self-Directed Learning Readiness (SDLR): Focused on Online College Students

    Science.gov (United States)

    Heo, JeongChul; Han, Sumi

    2018-01-01

    The purpose of this study is to determine whether the self-directed learning readiness (SDLR) among online students might be significantly predicted by motivation, academic stress, and age. To complete the purpose of this study, the Pearson correlation and multiple-regression are analyzed. The participants for this study are college students who…

  15. Horizontal drilling activity in Manitoba

    Energy Technology Data Exchange (ETDEWEB)

    Fox, J.

    1997-04-01

    An update of horizontal well drilling in Manitoba was provided. Manitoba`s productive formations are: (1) the Bakken Formation, (2) the Lodgepole Formation, (3) the Mission Canyon Formation, (4) the Amaranth Formation, and (5) the Melita Formation. A total of 28 exploratory wells and 29 development wells, including 11 horizontal wells were drilled in 1996. The 11 horizontal wells accounted for 30 per cent of the drilling meterage. The leading drillers for horizontal wells in Manitoba are Tundra Oil and Gas, Chevron, Anderson and HCO. Production from horizontal wells in 1996 totaled 310 cubic meter per day. To date, no horizontal wells have been drilled in the Bakken Formation. The least successful horizontal well application has been in the Lodgepole Formation. A summary of horizontal well production was provided for each Formation. 4 tabs., 10 figs.

  16. Convection flow study within a horizontal fluid layer under the action of gas flow

    Directory of Open Access Journals (Sweden)

    Kreta Aleksei

    2016-01-01

    Full Text Available Experimental investigation of convective processes within horizontal evaporating liquid layer under shear–stress of gas flow is presented. It is found the structures of the convection, which move in opposite direction relative to each other. First convective structure moves in reverse direction with the flow of gas, and the second convective structure moves towards the gas flow. Convection flow within the liquid layer is registered with help of PIV technique. Average evaporation flow rate of Ethanol liquid layer under Air gas flow is measured. Influence of the gas velocity, at a constant temperature of 20 °C, on the evaporation flow rate has been studied.

  17. Stability analysis of a horizontal coalbed methane well in the Rocky Mountain Front Ranges of southeast British Columbia, Canada

    Energy Technology Data Exchange (ETDEWEB)

    Gentzis, Thomas [Petron Resources, L.P., Suite 400, 3000 Internet Boulevard, Frisco, TX 75034 (United States)

    2009-01-31

    This study describes a wellbore stability analysis undertaken for a horizontal coalbed methane well in the Mist Mountain Formation, SE British Columbia, Canada. Three triaxial compression tests, with ultrasonic velocities, were conducted on 38-mm-diameter core plugs taken from a large, fresh block of Seam 7. Due to the small size of the tested samples, the laboratory-derived strength values were reduced to reflect the in-situ stress conditions considered relevant for a 156-mm-diameter horizontal well. The vertical stress gradient was calculated by integrating a bulk density log from an offset well. Horizontal maximum and minimum stresses were estimated from regional stress data, whereas formation pressure was estimated on the basis of a local hydrological study. The 2D elastoplastic STABView trademark numerical modeling code was used to forecast horizontal wellbore stability. The sensitivity of the predicted yielded zone size was examined for varying linear and non-linear rock strength criteria, horizontal in-situ stresses, bottom-hole pressures, formation pressure, drilling depth, and wall-coating efficiency. Stability analysis was performed at bottom-hole pressures ranging from overbalanced to underbalanced in order to simulate the conditions expected during drilling and production. The effects of weak bedding planes and varying well trajectories were also investigated. When drilling at 650 m depth under underbalanced to slightly overbalanced conditions, a high probability of getting the drill pipe stuck was predicted. STABView trademark showed that, if the 38-mm-diameter core plug strengths were used directly for forecasting purposes, the predicted yielded zone would be almost 20% overgauge when drilling at balanced conditions. When peak cohesion of coal was reduced by 50% to reflect the conditions expected along weak intervals of a horizontal wellbore, the predicted enlarged borehole was almost 85% overgauge under the same drilling conditions. The most unstable

  18. Stress

    Science.gov (United States)

    ... natural disaster. This type of stress can cause post-traumatic stress disorder (PTSD). Different people may feel stress in different ways. Some people experience digestive symptoms. Others may have headaches, sleeplessness, depressed mood, anger, ...

  19. Does Stress Result in You Exercising Less? Or Does Exercising Result in You Being Less Stressed? Or Is It Both? Testing the Bi-directional Stress-Exercise Association at the Group and Person (N of 1) Level.

    Science.gov (United States)

    Burg, Matthew M; Schwartz, Joseph E; Kronish, Ian M; Diaz, Keith M; Alcantara, Carmela; Duer-Hefele, Joan; Davidson, Karina W

    2017-03-13

    Psychosocial stress contributes to heart disease in part by adversely affecting maintenance of health behaviors, while exercise can reduce stress. Assessing the bi-directional relationship between stress and exercise has been limited by lack of real-time data and theoretical and statistical models. This lack may hinder efforts to promote exercise maintenance. We test the bi-directional relationship between stress and exercise using real-time data for the average person and the variability-individual differences-in this relationship. An observational study was conducted within a single cohort randomized controlled experiment. Healthy young adults, (n = 79) who reported only intermittent exercise, completed 12 months of stress monitoring by ecological momentary assessment (at the beginning of, end of, and during the day) and continuous activity monitoring by Fitbit. A random coefficients linear mixed model was used to predict end-of-day stress from the occurrence/non-occurrence of exercise that day; a logistic mixed model was used to predict the occurrence/non-occurrence of exercise from ratings of anticipated stress. Separate regression analyses were also performed for each participant. Sensitivity analysis tested all models, restricted to the first 180 days of observation (prior to randomization). We found a significant average inverse (i.e., negative) effect of exercise on stress and of stress on exercise. There was significant between-person variability. Of N = 69, exercise was associated with a stress reduction for 15, a stress increase for 2, and no change for the remainder. We also found that an increase in anticipated stress reported the previous night or that morning was associated with a significant 20-22% decrease (OR = 0.78-0.80) in the odds of exercising that day. Of N = 69, this increase in stress reduced the likelihood of exercise for 17, increased the odds for 1, and had no effect for the remainder. We were unable to identify psychosocial

  20. Efecto de un calentamiento con estiramientos estáticos y dinámicos sobre el salto horizontal y la capacidad para repetir esprint con cambio de dirección. [Effect of warm-up with static and dynamic stretching on the horizontal jump and repeated sprint ability with changes of direction

    National Research Council Canada - National Science Library

    Sánchez-Sánchez, Javier; Rodríguez-Fernández, Alejandro; Villa-Vicente, J. Gerardo; Petisco-Rodríguez, Cristina; Ramírez-Campillo, Rodrigo; Gonzalo-Skok, Oliver

    2017-01-01

    ... aeróbico sin estiramiento (CAE), con estiramiento estático (CAES) y con estiramiento dinámico (CAED). Se estudió el efecto agudo de cada calentamiento sobre el rendimiento en una prueba de salto horizontal...

  1. Horizontal bridges in polar dielectric liquids

    Energy Technology Data Exchange (ETDEWEB)

    Woisetschlaeger, Jakob [Graz University of Technology, Experimental Turbomachinery Research and Optical Measurement Group, Institute for Thermal Turbomachinery and Machine Dynamics, Graz (Austria); Wexler, Adam D.; Fuchs, Elmar C. [Wetsus, Center of Excellence for Sustainable Water Technology, Leeuwarden (Netherlands); Holler, Gert [Graz University of Technology, Institute of Electrical Measurement and Measurement Signal Processing, Graz (Austria); Eisenhut, Mathias [Graz University of Technology, Institute of Analytical Chemistry and Food Chemistry, Graz (Austria); Gatterer, Karl [Graz University of Technology, Institute of Physical and Theoretical Chemistry, Graz (Austria)

    2012-01-15

    When a high-voltage direct-current is applied to two beakers filled with polar liquid dielectrica like water or methanol, a horizontal bridge forms between the two beakers. By repeating a version of Pellat's experiment, it is shown that a horizontal bridge is stable by the action of electrohydrodynamic pressure. Thus, the static and dynamic properties of the phenomenon called a 'floating water bridge' can be explained by the gradient of Maxwell pressure, replenishing the liquid within the bridge against any drainage mechanism. It is also shown that a number of liquids can form stable and long horizontal bridges. The stability of such a connection, and the asymmetry in mass flow through such bridges caused by the formation of ion clouds in the vicinity of the electrodes, is also discussed by two further experiments. (orig.)

  2. Açaí (Euterpe oleracea Mart.) modulates oxidative stress resistance in Caenorhabditis elegans by direct and indirect mechanisms.

    Science.gov (United States)

    Bonomo, Larissa de Freitas; Silva, David Nunes; Boasquivis, Patrícia Ferreira; Paiva, Franciny Aparecida; Guerra, Joyce Ferreira da Costa; Martins, Talita Alves Faria; de Jesus Torres, Álvaro Gustavo; de Paula, Igor Thadeu Borges Raposo; Caneschi, Washington Luiz; Jacolot, Philippe; Grossin, Nicolas; Tessier, Frederic J; Boulanger, Eric; Silva, Marcelo Eustáquio; Pedrosa, Maria Lúcia; Oliveira, Riva de Paula

    2014-01-01

    Açaí (Euterpe oleracea Mart.) has recently emerged as a promising source of natural antioxidants. Despite its claimed pharmacological and nutraceutical value, studies regarding the effects of açaí in vivo are limited. In this study, we use the Caenorhabditis elegans model to evaluate the in vivo antioxidant properties of açaí on an organismal level and to examine its mechanism of action. Supplementation with açaí aqueous extract (AAE) increased both oxidative and osmotic stress resistance independently of any effect on reproduction and development. AAE suppressed bacterial growth, but this antimicrobial property did not influence stress resistance. AAE-increased stress resistance was correlated with reduced ROS production, the prevention of sulfhydryl (SH) level reduction and gcs-1 activation under oxidative stress conditions. Our mechanistic studies indicated that AAE promotes oxidative stress resistance by acting through DAF-16 and the osmotic stress response pathway OSR-1/UNC-43/SEK-1. Finally, AAE increased polyglutamine protein aggregation and decreased proteasome activity. Our findings suggest that natural compounds available in AAE can improve the antioxidant status of a whole organism under certain conditions by direct and indirect mechanisms.

  3. Açaí (Euterpe oleracea Mart. modulates oxidative stress resistance in Caenorhabditis elegans by direct and indirect mechanisms.

    Directory of Open Access Journals (Sweden)

    Larissa de Freitas Bonomo

    Full Text Available Açaí (Euterpe oleracea Mart. has recently emerged as a promising source of natural antioxidants. Despite its claimed pharmacological and nutraceutical value, studies regarding the effects of açaí in vivo are limited. In this study, we use the Caenorhabditis elegans model to evaluate the in vivo antioxidant properties of açaí on an organismal level and to examine its mechanism of action. Supplementation with açaí aqueous extract (AAE increased both oxidative and osmotic stress resistance independently of any effect on reproduction and development. AAE suppressed bacterial growth, but this antimicrobial property did not influence stress resistance. AAE-increased stress resistance was correlated with reduced ROS production, the prevention of sulfhydryl (SH level reduction and gcs-1 activation under oxidative stress conditions. Our mechanistic studies indicated that AAE promotes oxidative stress resistance by acting through DAF-16 and the osmotic stress response pathway OSR-1/UNC-43/SEK-1. Finally, AAE increased polyglutamine protein aggregation and decreased proteasome activity. Our findings suggest that natural compounds available in AAE can improve the antioxidant status of a whole organism under certain conditions by direct and indirect mechanisms.

  4. Oxidative Stress and Methods for Its Correction in Patients with Acute Coronary Circulatory Disorders During Perioperative Direct Myocardial Revascularization

    Directory of Open Access Journals (Sweden)

    M. V. Chumakov

    2008-01-01

    Full Text Available Objective: to study the effect of the antioxidant and cardioprotector mexicor on oxidative stress in patients with acute coronary circulatory disorders (ACCD during perioperative direct myocardial revascularization. Subjects and methods. The study included 33 patients with ACCD who had undergone coronary bypass surgery. Two groups (a study group and a control one were formed. Prior to surgery, all the patients received the maximum doses of antianginal and antihypertensive drugs. The study group patients additionally took mexicor. All patients were operated on under extracorporeal circulation and moderate hypothermia. Lipid peroxidation (LPO indices were estimated via measurements of the serum levels of dienic conjugates, malonic dialdehyde, and the degree of serum lipid oxidability. The serum antioxidative system (AOS was judged from the concentration of а-tocopherol and cerulo-plasmin. The oxidative stress coefficient K, an integral index, was calculated to evaluate LPO-AOS imbalance. Results. High oxidative stress was found to be detectable in patients with ACCD. Mexicor lowers oxidative stress, diminishes LPO-AOS imbalance, improves oxygen balance and cardiac contractility, and reduces the number of life-threatening cardiac arrhythmias. Conclusion. Mexicor diminishes oxidative stress in patients with ACCD in the perioperative period of coronary bypass surgery. Mexicor-induced stabilization of LPO positively affects better oxygen balance and cardiac contractility, thus reducing the number of perioperative complications. Key words: oxidative stress, dienic conjugates, malonic dialdehyde, а-tocopherol, ceruloplasmin, coronary bypass, acute coronary circulatory disorder, hemodynamics.

  5. Direct measurement of the alpha-epsilon transition stress and kinetics for shocked iron

    Energy Technology Data Exchange (ETDEWEB)

    Jensen, Brian J [Los Alamos National Laboratory; Gray, Ill, George T [Los Alamos National Laboratory; Hixson, Robert S [NAVAL POST-GRADUATE COLLEGE

    2009-01-01

    Iron undergoes a polymorphic phase transformation from alpha phase (bcc) to the epsilon phase (hcp) when compressed to stresses exceeding 13 CPa. Bccause the epsilon phase is denser than the alpha phase, a single shock wave is unstable and breaks up into an elastic wave, a plastic wave, and a phase transition wave. Examination of this structured wave coupled with various phase transformation models has been used to indirectly examine the transition kinetics. Recently, multimillion atom simulations (molecular dynamics) have been used to examine the shock-induced transition in single crystal iron illustrating an orientation dependence of the transition stress, mechanisms, and kinetics. The objective of the current work was to perform plate impact experiments to examine the shock-response of polycrystalline and single crystal iron with nanosecond resolution for impact stresses spanning the {alpha} - {epsilon} transition. The current data reveal an orientation dependence of the transition stress coupled with a transition time that is nonlinearly dependent on the impact stress with a duration ranging from picoseconds to hundreds of nanoseconds. The higher transition stress for iron[100] is in agreement with the predictions from MD calculations that describe an orientation dependence of the transition stress. However, MD calculations do not capture the complexity of the continuum states achieved or the transition kinetics. Further results and implications are discussed in this paper.

  6. Direct bed stress measurements under solitary tsunami-type waves and breaking tsunami wave fronts

    Digital Repository Service at National Institute of Oceanography (India)

    JayaKumar, S.; Baldock, T.E.

    steepen and eventually break, thereby generating large pressure gradients that could enhance the likelihood of liquefaction of the seabed. In the drawdown, high shear stresses could trigger debris flow in submarine canyons and on steep ridges. Therefore...

  7. A 24.5-Year Global Dataset of Direct Normal Irradiance: Result from the Application of a Global-to-Beam Model to the NASA GEWEX SRB Global Horizontal Irradiance

    Science.gov (United States)

    Zhang, T.; Stackhouse, P. W.; Chandler, W.; Hoell, J. M., Jr.; Westberg, D. J.

    2015-12-01

    The DIRINDEX model has previously been applied to the NASA GEWEX SRB Release 3.0 global horizontal irradiances (GHIs) to derive 3-hourly, daily and monthly mean direct normal irradiances (DNIs) for the period from 2000 to 2005 (http://dx.doi.org/10.1016/j.solener.2014.09.006), though the model was originally designed to estimate hourly DNIs from hourly GHIs. Input to the DIRINDEX model comprised 1.) the 3-hourly all-sky and clear-sky GHIs from the GEWEX SRB dataset; 2.) the surface pressure and the atmospheric column water vapor from the GEOS4 dataset; and 3.) daily mean aerosol optical depth at 700 nm derived from the daily mean aerosol data from the Model of Atmospheric Transport and CHemistry (MATCH). The GEWEX SRB data is spatially available on a quasi-equal-area global grid system consisting of 44016 boxes ranging from 1 degree latitude by 1 degree longitude around the Equator to 1 degree latitude by 120 degree longitude next to the poles. The derived DNIs were on the same grid system. Due to the limited availability of the MATCH aerosol data, the model was applied to the years from 2000 to 2005 only. The results were compared with ground-based measurements from 39 sites of the Baseline Surface Radiation Network (BSRN). The comparison statistics show that the results were in better agreement with their BSRN counterparts than the current Surface meteorology and Solar Energy (SSE) Release 6.0 data (https://eosweb.larc.nasa.gov/sse/). In this paper, we present results from the model over the entire time span of the GEWEX SRB Release 3.0 data (July 1983 to December2007) in which the MERRA atmospheric data were substituted for the GEOS4 data, and the Max-Planck Aerosol Climatology Version 1 (MAC-v1) data for the MATCH data. As a consequence, we derived a 24.5-year DNI dataset of global coverage continuous from July 1983 to December 2007. Comparisons with the BSRN data show that the results are comparable in quality with that from the earlier application.

  8. Sensitivity Analysis for Residual Stress on DVI (Direct Vessel Injection) Nozzle Welded Joint

    Energy Technology Data Exchange (ETDEWEB)

    Noh, Byeong Wook; Chung, Sung Ho; Lee, Jung Hun; Kim, Oak Sug [DOOSAN Heavy Industries and Construction Co. LTD, Reactor Design Team, 555 Guygok-dong Changwon (Korea, Republic of)

    2008-07-01

    Generally, any welding process produces high compressive or tensile residual stresses in the heat affected zone depending on the method, shape and procedures of the weldment. In particular, the tensile residual stresses have a considerable effect on the material strength, fatigue strength and corrosion cracking. For this reason, it is important that some knowledge of the internal stress state be deduced either from measurements or from modeling predictions. In this study, the residual stresses after a multi-pass welding process for DVI nozzle welding joint were evaluated by a numerical simulation method. The welding joint considered three weld joint angles of 40 deg., 6 deg. and 2 deg. Computations were made using a 2-D finite element model based on the simulation of cooling from the heat treatment temperature to room temperature with two cooling conditions at the inside surface. In these results, it is shown that the residual stress increased at the inner surface, when water cooling was applied to the inner surface, and axial compressive residual stress increased at the inner surface when the joint angle was decreased. (authors)

  9. HORIZONTAL BOILING REACTOR SYSTEM

    Science.gov (United States)

    Treshow, M.

    1958-11-18

    Reactors of the boiling water type are described wherein water serves both as the moderator and coolant. The reactor system consists essentially of a horizontal pressure vessel divided into two compartments by a weir, a thermal neutronic reactor core having vertical coolant passages and designed to use water as a moderator-coolant posltioned in one compartment, means for removing live steam from the other compartment and means for conveying feed-water and water from the steam compartment to the reactor compartment. The system further includes auxiliary apparatus to utilize the steam for driving a turbine and returning the condensate to the feed-water inlet of the reactor. The entire system is designed so that the reactor is self-regulating and has self-limiting power and self-limiting pressure features.

  10. PRODUCTIVITY OF FRACTURED HORIZONTAL WELLS

    Directory of Open Access Journals (Sweden)

    Stjepan Antolović

    2009-12-01

    Full Text Available The interest and performance of horizontal drilling and completions has increased during the last two decades. Horizontal wells are advantageous compared to vertical wells in thin reservoirs, reservoirs with favorable vertical permeability and reservoirs with water and gas coning problems. In many reservoirs, the ratio of horizontal permeability to the vertical permeability is substantially larger than one and often is close to 10. Thus, these reservoirs are very good candidates for hydraulic fracturing. By hydraulic fracturing one or more fractures are created, which can be longitudinal or orthogonal. By that, flow is altered and it mostly conducts horizontally through reservoir toward horizontal wellbore. With this altered flow, fluid is produced faster, with less pressure loss by fluid unit of produced fluid. Some of the existing mathematical models to determine the productivity of multifractured horizontal wells are presented in this work (the paper is published in Croatian.

  11. Transcription Factors and Plants Response to Drought Stress: Current Understanding and Future Directions

    Science.gov (United States)

    Joshi, Rohit; Wani, Shabir H.; Singh, Balwant; Bohra, Abhishek; Dar, Zahoor A.; Lone, Ajaz A.; Pareek, Ashwani; Singla-Pareek, Sneh L.

    2016-01-01

    Increasing vulnerability of plants to a variety of stresses such as drought, salt and extreme temperatures poses a global threat to sustained growth and productivity of major crops. Of these stresses, drought represents a considerable threat to plant growth and development. In view of this, developing staple food cultivars with improved drought tolerance emerges as the most sustainable solution toward improving crop productivity in a scenario of climate change. In parallel, unraveling the genetic architecture and the targeted identification of molecular networks using modern “OMICS” analyses, that can underpin drought tolerance mechanisms, is urgently required. Importantly, integrated studies intending to elucidate complex mechanisms can bridge the gap existing in our current knowledge about drought stress tolerance in plants. It is now well established that drought tolerance is regulated by several genes, including transcription factors (TFs) that enable plants to withstand unfavorable conditions, and these remain potential genomic candidates for their wide application in crop breeding. These TFs represent the key molecular switches orchestrating the regulation of plant developmental processes in response to a variety of stresses. The current review aims to offer a deeper understanding of TFs engaged in regulating plant’s response under drought stress and to devise potential strategies to improve plant tolerance against drought. PMID:27471513

  12. Transcription factors and plant response to drought stress: Current understanding and future directions

    Directory of Open Access Journals (Sweden)

    Rohit Joshi

    2016-07-01

    Full Text Available Increasing vulnerability of plants to a variety of stresses such as drought, salt and extreme temperatures poses a global threat to sustained growth and productivity of major crops. Of these stresses, drought represents a considerable threat to plant growth and development. In view of this, developing staple food cultivars with improved drought tolerance emerges as the most sustainable solution towards improving crop productivity in a scenario of climate change. In parallel, unraveling the genetic architecture and the targeted identification of molecular networks using modern OMICS analyses, that can underpin drought tolerance mechanisms, is urgently required. Importantly, integrated studies intending to elucidate complex mechanisms can bridge the gap existing in our current knowledge about drought stress tolerance in plants. It is now well established that drought tolerance is regulated by several genes, including transcription factors (TFs that enable plants to withstand unfavorable conditions, and these remain potential genomic candidates for their wide application in crop breeding. These TFs represent the key molecular switches orchestrating the regulation of plant developmental processes in response to a variety of stresses. The current review aims to offer a deeper understanding of TFs engaged in regulating plant’s response under drought stress and to devise potential strategies to improve plant tolerance against drought.

  13. Investigating the Influence of Regional Stress on Fault and Fracture Permeability at Pahute Mesa, Nevada National Security Site

    Energy Technology Data Exchange (ETDEWEB)

    Reeves, Donald M. [Desert Research Inst. (DRI), Reno, NV (United States); Smith, Kenneth D. [Univ. of Nevada, Reno, NV (United States); Parashar, Rishi [Desert Research Inst. (DRI), Reno, NV (United States); Collins, Cheryl [Desert Research Inst. (DRI), Las Vegas, NV (United States); Heintz, Kevin M. [Desert Research Inst. (DRI), Las Vegas, NV (United States)

    2017-05-24

    Regional stress may exert considerable control on the permeability and hydraulic function (i.e., barrier to and/or conduit for fluid flow) of faults and fractures at Pahute Mesa, Nevada National Security Site (NNSS). In-situ measurements of the stress field are sparse in this area, and short period earthquake focal mechanisms are used to delineate principal horizontal stress orientations. Stress field inversion solutions to earthquake focal mechanisms indicate that Pahute Mesa is located within a transtensional faulting regime, represented by oblique slip on steeply dipping normal fault structures, with maximum horizontal stress ranging from N29°E to N63°E and average of N42°E. Average horizontal stress directions are in general agreement with large diameter borehole breakouts from Pahute Mesa analyzed in this study and with stress measurements from other locations on the NNSS.

  14. Misdirected horizontal saccades in pan-cerebellar atrophy.

    Science.gov (United States)

    Shaikh, Aasef G; Ghasia, Fatema F

    2015-08-15

    Saccadic dysmetria is a sensitive marker of cerebellar dysfunction. We discovered misdirected horizontal saccades due to cross-coupled orthogonal (vertical) saccades in siblings with pan-cerebellar atrophy. There was an upward drift in vertical eye position after each cross-coupled downward saccade. Such drifts brought the eyes back to the desired target. Due to strong upward bias, downward compensatory slow movements did not follow cross-coupled upward saccades. There was minimal horizontal cross-coupling associated with vertical saccades. There was a reduced gain of horizontal pursuit causing lag in the horizontal eye movement and subsequent catch-up horizontal saccades. The horizontal catch-up saccades were also associated with vertical cross-coupled eye movements and subsequent drifts. There was no cross-coupling of pursuit eye movements. Our results support the hypothesis emphasizing adaptive cerebellar control of saccade direction. Commands for horizontal saccades trigger not only the activity of the horizontal burst generators, but also the vertical burst neurons. The activity of orthogonal (vertical) burst neurons is canceled by opposing signals under cerebellar supervision. Cerebellar lesions could disrupt such balance between opposing orthogonal signals leading to vertical cross-coupling during horizontal saccade. We speculate that upward drift might result from an imbalance in opposing orthogonal signals at the level of neural integrators. Copyright © 2015 Elsevier B.V. All rights reserved.

  15. Gender Effect According to Item Directionality on the Perceived Stress Scale for Adults with Multiple Sclerosis

    Science.gov (United States)

    Gitchel, W. Dent; Roessler, Richard T.; Turner, Ronna C.

    2011-01-01

    Assessment is critical to rehabilitation practice and research, and self-reports are a commonly used form of assessment. This study examines a gender effect according to item wording on the "Perceived Stress Scale" for adults with multiple sclerosis. Past studies have demonstrated two-factor solutions on this scale and other scales measuring…

  16. Determination of in-situ rock stresses related to petroleum activities on the Norwegian Continental Shelf

    Energy Technology Data Exchange (ETDEWEB)

    Fejerskov, Morten

    1996-12-31

    In-situ rock stresses have proved to be important for exploration and production of hydrocarbons. This thesis uses various stress determination techniques to characterize the in-situ stress field on the Norwegian Continental Shelf. Leak off tests and borehole breakouts have been used to determine the in-situ stress in deep well bores. Overcoring and earthquake focal mechanisms data have also been compiled and evaluated together with stress information from petroleum wells. A new test procedure is suggested to improve the quality of leak off tests that emphasises the importance of accurate pressure determination, longer test periods and digital data sampling. Four-arm calliper logs are used to identify borehole breakouts on the Tampen Spur and Horda Platform. However, it proved difficult to distinguish borehole breakouts from other drilling processes since the elongations of the borehole consistently appeared in the direction of hole azimuth; drilling-induced key seats are here observed in vertical wells. This behaviour is discussed but not fully understood. This reduces the number of reliable stress data and their quality enormously and even casts some doubt about the quality of previous breakout studies from the North Sea. A highly compressive horizontal stress field seems to be present onshore and offshore Norway. Different stress determination techniques yield very consistent stress orientation, regional and internal variation. A 1. order stress direction is identified, where the maximum horizontal stress direction is rotating from N-S in the Barents Sea to NW-SE in the Norwegian Sea and WNW-ESE in the northern North Sea. At Tampen Spur, a dominant WNW-ESE maximum horizontal stress direction, normal to the major tectonic structures is identified as well as a minimum stress close to the vertical stress, the latter indicating high horizontal stresses. 250 refs., 91 figs., 14 tabs.

  17. Efecto de un calentamiento con estiramientos estáticos y dinámicos sobre el salto horizontal y la capacidad para repetir esprint con cambio de dirección. [Effect of warm-up with static and dynamic stretching on the horizontal jump and repeated sprint ability with changes of direction].

    OpenAIRE

    Javier Sánchez-Sánchez; Alejandro Rodríguez-Fernández; J. Gerardo Villa-Vicente; Cristina Petisco-Rodríguez; Rodrigo Ramírez-Campillo; Oliver Gonzalo-Skok

    2017-01-01

    El objetivo de este trabajo ha sido comparar el efecto de tres calentamientos diferentes (calentamiento aeróbico de baja intensidad, estiramiento estático y estiramiento dinámico) sobre el salto horizontal y la capacidad de repetir esprint con cambios de dirección. Diecisiete practicantes de deportes de equipo de 20.8±1.1 años realizaron 3 tipos de calentamiento (10 min): ejercicio aeróbico sin estiramiento (CAE), con estiramiento estático (CAES) y con estiramiento dinámico (CAED). Se estudió...

  18. Ethanol adaptation induces direct protection and cross-protection against freezing stress in Salmonella enterica serovar Enteritidis.

    Science.gov (United States)

    He, S; Zhou, X; Shi, C; Shi, X

    2016-03-01

    Salmonella enterica serovar Enteritidis (Salm. Enteritidis) encounters mild ethanol stress during its life cycle. However, adaptation to a stressful condition may affect bacterial resistance to subsequent stresses. Hence, this work was undertaken to investigate the influences of ethanol adaptation on stress tolerance of Salm. Enteritidis. Salmonella Enteritidis was subjected to different ethanol adaptation treatments (2·5-10% ethanol for 1 h). Cellular morphology and tolerance to subsequent environmental stresses (15% ethanol, -20°C, 4°C, 50°C and 10% NaCl) were evaluated. It was found that 10% was the maximum ethanol concentration that allowed growth of the target bacteria. Ethanol adaptation did not cause cell-surface damage in Salm. Enteritidis as revealed by membrane permeability measurements and electron micrograph analysis. Salmonella Enteritidis adapted with 2·5-10% ethanol displayed an enhanced resistance to a 15%-ethanol challenge compared with an unchallenged control. The maximum ethanol resistance was observed when ethanol concentration used for ethanol adaptation was increased to 5·0%. Additionally, pre-adaptation to 5·0% ethanol cross-protected Salm. Enteritidis against -20°C, but not against 4°C, 50°C or 10% NaCl. Ethanol adaptation provided Salm. Enteritidis direct protection from a high level ethanol challenge and cross-protection from freezing, but not other stresses tested (low temperature, high salinity or high temperature). The results are valuable in developing adequate and efficient control measures for Salm. Enteritidis in foods. © 2016 The Society for Applied Microbiology.

  19. Teacher-Directed Violence in Relation to Social Support and Work Stress

    Science.gov (United States)

    Bounds, Christina; Jenkins, Lyndsay N.

    2016-01-01

    Teacher-directed violence, or violence found in a school setting that involves teacher victimization (Espelage et al. in "The American Psychologist," 68(2), 75-87, 2011), is a relatively new area of study in education. Teacher-directed violence or teacher victimization includes obscene gestures/remarks, harassment, verbal threats, and…

  20. Posttraumatic stress disorder-like induction elevates β-amyloid levels, which directly activates corticotropin-releasing factor neurons to exacerbate stress responses.

    Science.gov (United States)

    Justice, Nicholas J; Huang, Longwen; Tian, Jin-Bin; Cole, Allysa; Pruski, Melissa; Hunt, Albert J; Flores, Rene; Zhu, Michael X; Arenkiel, Benjamin R; Zheng, Hui

    2015-02-11

    Recent studies have found that those who suffer from posttraumatic stress disorder (PTSD) are more likely to experience dementia as they age, most often Alzheimer's disease (AD). These findings suggest that the symptoms of PTSD might have an exacerbating effect on AD progression. AD and PTSD might also share common susceptibility factors such that those who experience trauma-induced disease were already more likely to succumb to dementia with age. Here, we explored these two hypotheses using a mouse model of PTSD in wild-type and AD model animals. We found that expression of human familial AD mutations in amyloid precursor protein and presenilin 1 leads to sensitivity to trauma-induced PTSD-like changes in behavioral and endocrine stress responses. PTSD-like induction, in turn, chronically elevates levels of CSF β-amyloid (Aβ), exacerbating ongoing AD pathogenesis. We show that PTSD-like induction and Aβ elevation are dependent on corticotropin-releasing factor (CRF) receptor 1 signaling and an intact hypothalamic-pituitary-adrenal axis. Furthermore, we show that Aβ species can hyperexcite CRF neurons, providing a mechanism by which Aβ influences stress-related symptoms and PTSD-like phenotypes. Consistent with Aβ causing excitability of the stress circuitry, we attenuate PTSD-like phenotypes in vivo by lowering Aβ levels during PTSD-like trauma exposure. Together, these data demonstrate that exposure to PTSD-like trauma can drive AD pathogenesis, which directly perturbs CRF signaling, thereby enhancing chronic PTSD symptoms while increasing risk for AD-related dementia. Copyright © 2015 the authors 0270-6474/15/352612-12$15.00/0.

  1. Prevention of Post-Traumatic Stress Disorder After Trauma: Current Evidence and Future Directions.

    Science.gov (United States)

    Qi, Wei; Gevonden, Martin; Shalev, Arieh

    2016-02-01

    Post-traumatic stress disorder (PTSD) is a frequent, tenacious, and disabling consequence of traumatic events. The disorder's identifiable onset and early symptoms provide opportunities for early detection and prevention. Empirical findings and theoretical models have outlined specific risk factors and pathogenic processes leading to PTSD. Controlled studies have shown that theory-driven preventive interventions, such as cognitive behavioral therapy (CBT), or stress hormone-targeted pharmacological interventions, are efficacious in selected samples of survivors. However, the effectiveness of early clinical interventions remains unknown, and results obtained in aggregates (large groups) overlook individual heterogeneity in PTSD pathogenesis. We review current evidence of PTSD prevention and outline the need to improve the disorder's early detection and intervention in individual-specific paths to chronic PTSD.

  2. Standard practice for preparation and use of direct tension stress-corrosion test specimens

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    1985-01-01

    1.1 This practice covers procedures for designing, preparing, and using ASTM standard tension test specimens for investigating susceptibility to stress-corrosion cracking. Axially loaded specimens may be stressed quantitatively with equipment for application of either a constant load, constant strain, or with a continuously increasing strain. 1.2 Tension test specimens are adaptable for testing a wide variety of product forms as well as parts joined by welding, riveting, or various other methods. 1.3 The exposure of specimens in a corrosive environment is treated only briefly because other standards are being prepared to deal with this aspect. Meanwhile, the investigator is referred to Practices G35, G36, G37, and G44, and to ASTM Special Technical Publication 425 (1).

  3. Direct measurement of cell wall stress-stiffening and turgor pressure in live bacterial cells

    CERN Document Server

    Deng, Yi; Shaevitz, Joshua W

    2011-01-01

    The mechanical properties of gram-negative bacteria are governed by a rigid peptidoglycan (PG) cell wall and the turgor pressure generated by the large concentration of solutes in the cytoplasm. The elasticity of the PG has been measured in bulk and in isolated sacculi and shown to be compliant compared to the overall stiffness of the cell itself. However, the stiffness of the cell wall in live cells has not been measured. In particular, the effects that pressure-induced stress might have on the stiffness of the mesh-like PG network have not been addressed even though polymeric materials often exhibit large amounts of stress-stiffening. We study bulging Escherichia coli cells using atomic force microscopy to separate the contributions of the cell wall and turgor pressure to the overall cell stiffness. We find strong evidence of power-law stress-stiffening in the E. coli cell wall, with an exponent of $1.07 \\pm 0.25$, such that the wall is significantly stiffer in live cells ($E\\sim32\\pm10$ MPa) than in unpres...

  4. Comparative study for salt stress among seed, root stock and direct ...

    African Journals Online (AJOL)

    USER

    2010-04-05

    Apr 5, 2010 ... Direct regenerated violet showed better plant growth significantly both in saline and .... carefully under running tap water and plants with good shoot and root were allowed to grow. ...... Hydroponic treatment with salicylic acid ...

  5. Direct observation of binding stress-induced crystalline orientation change in piezoelectric plate sensors

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Wei; Shih, Wei-Heng [Department of Materials Science and Engineering, Drexel University, Philadelphia, Pennsylvania 19104 (United States); Shih, Wan Y., E-mail: shihwy@drexel.edu [School of Biomedical Engineering, Science and Health Systems, Drexel University, Philadelphia, Pennsylvania 19104 (United States)

    2016-03-28

    We have examined the mechanism of the detection resonance frequency shift, Δf/f, of a 1370 μm long and 537 μm wide [Pb(Mg{sub 1/3}Nb{sub 2/3})O{sub 3}]{sub 0.65}[PbTiO{sub 3}]{sub 0.35} (PMN-PT) piezoelectric plate sensor (PEPS) made of a 8-μm thick PMN-PT freestanding film. The Δf/f of the PEPS was monitored in a three-step binding model detections of (1) binding of maleimide-activated biotin to the sulfhydryl on the PEPS surface followed by (2) binding of streptavidin to the bound biotin and (3) subsequent binding of biotinylated probe deoxyribonucleic acid to the bound streptavidin. We used a PMN-PT surrogate made of the same 8-μm thick PMN-PT freestanding film that the PEPS was made of but was about 1 cm in length and width to carry out crystalline orientation study using X-ray diffraction (XRD) scan around the (002)/(200) peaks after each of the binding steps. The result of the XRD studies indicated that each binding step caused the crystalline orientation of the PMN-PT thin layer to switch from the vertical (002) orientation to the horizontal (200) orientation, and most of the PEPS detection Δf/f was due to the change in the lateral Young's modulus of the PMN-PT thin layer as a result of the crystalline orientation change.

  6. Horizontal motions, bedrock incision, and the structure of relief in growing folds and orogens

    Science.gov (United States)

    Seixas, G.; Alejandre, J.; Hilley, G. E.

    2013-12-01

    Topographic divide asymmetry may arise from gradients in rock erodibility and orographic precipitation across a mountain belt, and/or tectonic displacement fields that uplift and translate rock horizontally during orogenesis. While simple models exploring relief in active orogens typically consider tectonic motions that are uniform and vertical, the displacement field at Earth's surface generated by slip on finite-length faults is inherently inhomogeneous and contains vertical and horizontal components, which may play an important role in divide asymmetry. In this study, we consider channel profiles that evolve according to the shear stress rule for bedrock fluvial erosion and that experience inhomogeneous horizontal and vertical components of tectonic motion. Dimensional analysis of our revised shear stress rule reveals a dimensionless coefficient that relates bedrock erodibility and basin geometry to slip rate on the underlying fault. We implement our model in a series of 1D non-dimensional numerical experiments that calculate river profile geometry on either side of a topographic divide that is free to advect through the model domain in response to horizontal motion. We drive the models with displacements calculated over a dipping, buried edge dislocation, and examine non-dimensional relief and divide asymmetry resulting from variations in fault dip, non-dimensional fault tip location and non-dimensional model extent. We find that asymmetry results from the full displacement field and from the vertical displacement field alone. Fault dip plays a strong role in the magnitude and direction of divide asymmetry, both in models that include the horizontal motions and those that neglect them. The greatest divide asymmetry resulting from the full displacement field is achieved over dislocations with shallow non-dimensional upper tip depths and small dip angles, although steeply-dipping faults produce asymmetry in the opposite direction. By setting the horizontal

  7. Thermal stress induced dislocation distribution in directional solidification of Si for PV application

    Science.gov (United States)

    Jiptner, Karolin; Gao, Bing; Harada, Hirofumi; Miyamura, Yoshiji; Fukuzawa, Masayuki; Kakimoto, Koichi; Sekiguchi, Takashi

    2014-12-01

    This paper presents the limitation of the cast technique for silicon growth and the obstacle to reduce the dislocation density below 103 cm-2. The thermal stress induced dislocation density, independent of other dislocation sources, is determined and the result suggests that local dislocation densities as high as 104 cm-2 are readily introduced alone in the cooling period of the crystal growth. Areas of high residual strain and dislocation densities are identified and presented. The experimental results are correlated with numerical simulation based on a three-dimensional Haasen-Alexander-Sumino (HAS) model. The dislocation introduction is caused by an activation of different slip systems in different ingot areas.

  8. Horizontal gene transfer in the acquisition of novel traits by metazoans.

    Science.gov (United States)

    Boto, Luis

    2014-02-22

    Horizontal gene transfer is accepted as an important evolutionary force modulating the evolution of prokaryote genomes. However, it is thought that horizontal gene transfer plays only a minor role in metazoan evolution. In this paper, I critically review the rising evidence on horizontally transferred genes and on the acquisition of novel traits in metazoans. In particular, I discuss suspected examples in sponges, cnidarians, rotifers, nematodes, molluscs and arthropods which suggest that horizontal gene transfer in metazoans is not simply a curiosity. In addition, I stress the scarcity of studies in vertebrates and other animal groups and the importance of forthcoming studies to understand the importance and extent of horizontal gene transfer in animals.

  9. Surgical procedures and pediatric medical traumatic stress (PMTS) syndrome: Assessment and future directions.

    Science.gov (United States)

    Ari, Amichai Ben; Peri, Tuvia; Margalit, Daniella; Galili-Weisstub, Esti; Udassin, Raphael; Benarroch, Fortu

    2017-10-16

    Surgical procedures involve traumatic stress. Children may develop chronic psychological distress and dysfunction after surgery, with consequent reluctance to comply with medical follow-up care. A literature review of this topic shows that it has been understudied. Our study aims to assess the frequency and characteristics of symptoms of persistent psychological distress in children following surgery, which have not been documented before, in order to promote its awareness and its early identification. Parents of 79 children (aged 1-6) that were hospitalized in a pediatric surgical ward, comprising a representative sample, completed three validated questionnaires assessing their children's psychological symptoms 3-5months after the hospitalization. A significant portion of children suffer from psychological distress 3-5months after hospitalization. Moreover, 10.39% of the children exhibited symptoms of PTSD, and 28.6% of parents reported that the child's distress causes dysfunction. Additionally, our findings emphasize the parents' concerns regarding the child's behavior, function, and health following hospitalization. Since a significant prevalence of hospitalization-related traumatic stress is documented, the awareness to it has to be improved, in order to reduce its frequency and increase adherence to medical follow-up care. Prognosis study. 1. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. Epigenetics of Posttraumatic Stress Disorder: Current Evidence, Challenges, and Future Directions.

    Science.gov (United States)

    Zannas, Anthony S; Provençal, Nadine; Binder, Elisabeth B

    2015-09-01

    Posttraumatic stress disorder (PTSD) is a stress-related psychiatric disorder that is thought to emerge from complex interactions among traumatic events and multiple genetic factors. Epigenetic regulation lies at the heart of these interactions and mediates the lasting effects of the environment on gene regulation. An increasing body of evidence in human subjects with PTSD supports a role for epigenetic regulation of distinct genes and pathways in the pathogenesis of PTSD. The role of epigenetic regulation is further supported by studies examining fear conditioning in rodent models. Although this line of research offers an exciting outlook for future epigenetic research in PTSD, important limitations include the tissue specificity of epigenetic modifications, the phenomenologic definition of the disorder, and the challenge of translating molecular evidence across species. These limitations call for studies that combine data from postmortem human brain tissue and animal models, assess longitudinal epigenetic changes in living subjects, and examine dimensional phenotypes in addition to diagnoses. Moreover, examining the environmental, genetic, and epigenetic factors that promote resilience to trauma may lead to important advances in the field. Copyright © 2015 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

  11. A comparison of stresses in molar teeth restored with inlays and direct restorations, including polymerization shrinkage of composite resin and tooth loading during mastication.

    Science.gov (United States)

    Dejak, Beata; Młotkowski, Andrzej

    2015-03-01

    Polymerization shrinkage of composites is one of the main causes of leakage around dental restorations. Despite the large numbers of studies there is no consensus, what kind of teeth reconstruction--direct or indirect composite restorations are the most beneficial and the most durable. The aim was to compare equivalent stresses and contact adhesive stresses in molar teeth with class II MOD cavities, which were restored with inlays and direct restorations (taking into account polymerization shrinkage of composite resin) during simulated mastication. The study was conducted using the finite elements method with the application of contact elements. Three 3D models of first molars were created: model A was an intact tooth; model B--a tooth with a composite inlay, and model C--a tooth with a direct composite restoration. Polymerization linear shrinkage 0.7% of a direct composite restoration and resin luting cement was simulated (load 1). A computer simulation of mastication was performed (load 2). In these 2 situations, equivalent stresses according to the modified von Mises criterion (mvM) in the materials of mandibular first molar models with different restorations were calculated and compared. Contact stresses in the luting cement-tooth tissue adhesive interface around the restorations were also assessed and analyzed. Equivalent stresses in a tooth with a direct composite restoration (the entire volume of which was affected by polymerization shrinkage) were many times higher than in the tooth restored with a composite inlay (where shrinkage was present only in a thin layer of the luting cement). In dentin and enamel the stress values were 8-14 times higher, and were 13 times higher in the direct restoration than in the inlay. Likewise, contact stresses in the adhesive bond around the direct restoration were 6.5-7.7 times higher compared to an extraorally cured restoration. In the masticatory simulation, shear contact stresses in the adhesive bond around the direct

  12. Acute shear stress direction dictates adherent cell remodeling and verifies shear profile of spinning disk assays.

    Science.gov (United States)

    Fuhrmann, Alexander; Engler, Adam J

    2015-01-26

    Several methods have been developed to quantify population level changes in cell attachment strength given its large heterogeneity. One such method is the rotating disk chamber or 'spinning disk' in which a range of shear forces are applied to attached cells to quantify detachment force, i.e. attachment strength, which can be heterogeneous within cell populations. However, computing the exact force vectors that act upon cells is complicated by complex flow fields and variable cell morphologies. Recent observations suggest that cells may remodel their morphology and align during acute shear exposure, but contrary to intuition, shear is not orthogonal to the radial direction. Here we theoretically derive the magnitude and direction of applied shear and demonstrate that cells, under certain physiological conditions, align in this direction within minutes. Shear force magnitude is also experimentally verified which validates that for spread cells shear forces and not torque or drag dominate in this assay, and demonstrates that the applied force per cell area is largely independent of initial morphology. These findings suggest that direct quantified comparison of the effects of shear on a wide array of cell types and conditions can be made with confidence using this assay without the need for computational or numerical modeling.

  13. Crack edge collocation for the direct computation of stress intensity factors using the displacement discontinuity method

    CSIR Research Space (South Africa)

    Napier, JAL

    2002-09-01

    Full Text Available intensity factors to be solved directly at the crack edges. This is achieved by employing an enhanced edge collocation procedure. The limiting interpretation of the governing integral equations is discussed and two simple examples are presented to illustrate...

  14. Buoyancy Driven Natural Ventilation through Horizontal Openings

    DEFF Research Database (Denmark)

    Heiselberg, Per; Li, Zhigang

    2009-01-01

    An experimental study of the phenomenon of buoyancy driven natural ventilation through single-sided horizontal openings was performed in a full-scale laboratory test rig. The measurements were made for opening ratios L/D ranging from 0.027 to 4.455, where L and D are the length of the opening...... and the diameter of the opening, respectively. The basic nature of airflow through single-sided openings, including airflow rate, air velocity, temperature difference between the rooms and the dimensions of the horizontal openings, were measured. A bi-directional airflow rate was measured using the constant...... quite well with the Epstein's formula but in other cases the measured data show clear deviations from the Epstein's formula. Thus, revised formulas for natural ventilation are proposed....

  15. Buoyancy Driven Natural Ventilation through Horizontal Openings

    DEFF Research Database (Denmark)

    Heiselberg, Per

    2009-01-01

    An experimental study of the phenomenon of buoyancy driven natural ventilation through single-sided horizontal openings was performed in a full-scale laboratory test rig. The measurements were made for opening ratios L/D ranging from 0.027 to 4.455, where L and D are the length of the opening...... and the diameter of the opening, respectively. The basic nature of airflow through single-sided openings, including airflow rate, air velocity, temperature difference between the rooms and the dimensions of the horizontal openings, were measured. A bi-directional airflow rate was measured using the constant...... quite well with the Epstein's formula ratio are presented. In some cases the measured airflow rates fit quite well with the Epstein's formula but in other cases the measured data show clear deviations from the Epstein's formula. Thus, revised formulas for natural ventilation are proposed....

  16. Study on Horizontally Polarized Omnidirectional Microstrip Antenna

    Directory of Open Access Journals (Sweden)

    Kun Wei

    2016-01-01

    Full Text Available A horizontally polarized omnidirectional microstrip antenna is proposed in this paper. The structure of designed antenna is with two back-to-back horizontally polarized microstrip antenna elements. Gain variation on main radiation plane of this new antenna is analyzed and radiation theory is deduced; formula of directivity on main radiation plane is given. Better omnidirectional characteristic of this antenna can be obtained by decreasing patch physical length. Both simulated and measured results verify the omnidirectional radiation patterns and input impedance characteristics. Good omnidirectional radiation patterns (gain variation in E-plane less than ±0.4 dBi and input impedance characteristics are obtained; moreover, cross polarization less than −20 dBi is achieved.

  17. Cold-Cracking Assessment in AA7050 Billets during Direct-Chill Casting by Thermomechanical Simulation of Residual Thermal Stresses and Application of Fracture Mechanics

    NARCIS (Netherlands)

    Lalpoor, M.; Eskin, D.G.; Katgerman, L.

    2009-01-01

    Thermally induced strains and stresses developed during direct-chill (DC) semicontinuous casting of high strength aluminum alloys can result in formation of micro-cracks in different locations of the billet. Rapid propagation of such micro-cracks in tensile thermal stress fields can lead to

  18. Horizontal and Vertical Line Designs.

    Science.gov (United States)

    Johns, Pat

    2003-01-01

    Presents an art lesson in which students learn about the artist Piet Mondrian and create their own abstract artworks. Focuses on geometric shapes using horizontal and vertical lines. Includes background information about the artist. (CMK)

  19. DNA Damage Response Pathway and Replication Fork Stress During Oligonucleotide Directed Gene Editing

    OpenAIRE

    Bonner, Melissa; Strouse,Bryan; Applegate, Mindy; Livingston, Paula; Kmiec, Eric B.

    2012-01-01

    Single-stranded DNA oligonucleotides (ODNs) can be used to direct the exchange of nucleotides in the genome of mammalian cells in a process known as gene editing. Once refined, gene editing should become a viable option for gene therapy and molecular medicine. Gene editing is regulated by a number of DNA recombination and repair pathways whose natural activities often lead to single- and double-stranded DNA breaks. It has been previously shown that introduction of a phosphorotioated ODN, desi...

  20. Combining stress transfer and source directivity: the case of the 2012 Emilia seismic sequence

    OpenAIRE

    Vincenzo Convertito; Flaminia Catalli; Antonio Emolo

    2013-01-01

    The Emilia seismic sequence (Northern Italy) started on May 2012 and caused 17 casualties, severe damage to dwellings and forced the closure of several factories. The total number of events recorded in one month was about 2100, with local magnitude ranging between 1.0 and 5.9. We investigate potential mechanisms (static and dynamic triggering) that may describe the evolution of the sequence. We consider rupture directivity in the dynamic strain field and observe that, for each main earthquake...

  1. Radiation effects on bifurcation and dual solutions in transient natural convection in a horizontal annulus

    National Research Council Canada - National Science Library

    Luo, Kang; Yi, Hong-Liang; Tan, He-Ping

    2014-01-01

    Transitions and bifurcations of transient natural convection in a horizontal annulus with radiatively participating medium are numerically investigated using the coupled lattice Boltzmann and direct...

  2. Stress

    DEFF Research Database (Denmark)

    Keller, Hanne Dauer

    2015-01-01

    Kapitlet handler om stress som følelse, og det trækker primært på de få kvalitative undersøgelser, der er lavet af stressforløb.......Kapitlet handler om stress som følelse, og det trækker primært på de få kvalitative undersøgelser, der er lavet af stressforløb....

  3. Notes on the horizontal cohomology

    OpenAIRE

    Verbovetsky, Alexander

    1998-01-01

    This paper is devoted to the horizontal (``characteristic'') cohomology of systems of differential equations. Recent results on computing the horizontal cohomology via the compatibility complex are generalized. New results on the Vinogradov C-spectral sequence and the Krasil'shchik C-cohomology are obtained. As an application of general theory, the examples of an evolution equation and a p-form gauge theory are explicitly worked out.

  4. Mechanisms of Horizontal Gene Transfer

    OpenAIRE

    Cafini Barrado, Fabio; Medrano Romero, Verónica; Morikawa, Kazuya

    2017-01-01

    Horizontal gene transfer plays important roles in the evolution of S. aureus, and indeed, a variety of virulence factors and antibiotic resistance genes are embedded in a series of mobile genetic elements. In this chapter, we review the mechanisms of horizontal gene transfer, including recent findings on the natural genetic competence. Then, we consider the transfer of two important antibiotic resistance genes: the methicillin resistance gene, mecA (in Staphylococcal Cassette Chromosome) and ...

  5. Investigating biological traces of traumatic stress in changing societies: challenges and directions from the ESTSS Task Force on Neurobiology.

    Science.gov (United States)

    Thomaes, Kathleen; de Kloet, Carien; Wilker, Sarah; El-Hage, Wissam; Schäfer, Ingo; Kleim, Birgit; Schmahl, Christian; van Zuiden, Mirjam

    2016-01-01

    Traumatic stress can have severe consequences for both mental and physical health. Furthermore, both psychological and biological traces of trauma increase as a function of accumulating traumatic experiences. Neurobiological research may aid in limiting the impact of traumatic stress, by leading to advances in preventive and treatment interventions. To promote the possibility for clinical implementation of novel research findings, this brief review describes timely conceptual and methodological challenges and directions in neurobiological trauma research on behalf of the Task Force "Neurobiology of Traumatic Stress" of the European Society for Traumatic Stress Studies (ESTSS). The most important conceptual challenges are the heterogeneity of disorders and existence of subtypes across diagnostic categories: differential latent profiles and trajectories regarding symptom expression and neural correlates are being unraveled; however, similar latent classes' approaches for treatment response and neurobiological data remain scarce thus far. The key to improving the efficacy of currently available preventive interventions and treatments for trauma-related disorders lies in a better understanding and characterization of individual differences in response to trauma and interventions. This could lead to personalized treatment strategies for trauma-related disorders, based on objective information indicating whether individuals are expected to benefit from them. The most important methodological challenge identified here is the need for large consortia and meta-analyses or, rather, mega-analyses on existent data as a first step. In addition, large multicenter studies, combining novel methods for repeated sampling with more advanced statistical modeling techniques, such as machine learning, should aim to translate identified disease mechanisms into molecular blood-based biomarker combinations to predict disorder vulnerability and treatment responses.

  6. Healing and Shear Stress Reduction on Single Fracture of Rock Salt and Limestone under Slide-Hold-Slide Direct Shear Condition

    Science.gov (United States)

    Kishida, K.; Yano, T.; Yasuhara, H.

    2012-12-01

    In order to clarify the influence of the holding state on the shear strength in the shear process of a single rock fracture, slide-hold-slide (SHS) direct shear-flow coupling tests were carried out on single rock fractures at several confining stresses and under saturated/unsaturated conditions (Kishida, et al., 2011). Consequently, the mortar specimen could be confirmed as the significant shear strength recovery on the SHS process. In this research, the SHS direct shear tests are carried out on the halite (rock salt) and the limestone. In the case of rock salt, a single tensile fracture is artificially created by cutting away. On the other hand, the limestone has a natural rock joint. The experiments are carried out under various normal confining stress conditions and are employed various holding period at the residual state. Figure 1 shows the shear stress - shear displacement of the SHS direct shear experiments on the rock salt. From all cases, the shear stress increases at the initial phase of the experiments, and then, the shear stress reaches at the peak shear strength. After that, the shear stress slightly decreases such as strain softening. Finally, the shear stress reaches to the residual stress state. In every SHS processes, the shear stress is reducing in various hold period. And then, the shear stress is increasing in the process of re-sliding. The shear stress in the process of re-sliding takes over the value at the start time of the holding process. The shear stress reaches at the peak, and then, it reaches the residual stress state. In all cases, as the holding period becomes longer, it is confirmed that the decrement of the shear stress in the holding process is increasing and the increment of the shear stress at the re-sliding process is increasing. Therefore, it is confirmed that the time dependence of shear strength recovery can be observed. In addition, Dieterich's A constant value for the regression lines (Dieterich, 1972, 1994) is plotted

  7. Poverty, Stress, and Brain Development: New Directions for Prevention and Intervention

    Science.gov (United States)

    Blair, Clancy; Raver, C. Cybele

    2018-01-01

    We review some of the growing evidence of the costs of poverty to children’s neuroendocrine function, early brain development, and cognitive ability. We underscore the importance of addressing the negative consequences of poverty-related adversity early in children’s lives, given evidence supporting the plasticity of executive functions and associated physiologic processes in response to early intervention and the importance of higher order cognitive functions for success in school and in life. Finally, we highlight some new directions for prevention and intervention that are rapidly emerging at the intersection of developmental science, pediatrics, child psychology and psychiatry, and public policy. PMID:27044699

  8. Poverty, Stress, and Brain Development: New Directions for Prevention and Intervention.

    Science.gov (United States)

    Blair, Clancy; Raver, C Cybele

    2016-04-01

    We review some of the growing evidence of the costs of poverty to children's neuroendocrine function, early brain development, and cognitive ability. We underscore the importance of addressing the negative consequences of poverty-related adversity early in children's lives, given evidence supporting the plasticity of executive functions and associated physiologic processes in response to early intervention and the importance of higher order cognitive functions for success in school and in life. Finally, we highlight some new directions for prevention and intervention that are rapidly emerging at the intersection of developmental science, pediatrics, child psychology and psychiatry, and public policy. Copyright © 2016 Academic Pediatric Association. Published by Elsevier Inc. All rights reserved.

  9. Modeling of inelastic deformation around vertical and horizontal wells

    Science.gov (United States)

    Stefanov, Yu. P.; Myasnikov, A. V.

    2015-10-01

    The paper presents numerical modeling results on plastic deformation development around vertical and horizontal wells in rocks for four lithologies typical of the Bazhenov formation. Estimates of irreversible deformation were obtained depending on wellbore pressure, in-situ stress distribution and rock dilation factor. Computational results showed that for the considered lithology borehole pressure management does not always provide wellbore stability if the contrast between principal stresses is large enough.

  10. Portable top drive cuts horizontal drilling costs

    Energy Technology Data Exchange (ETDEWEB)

    Jackson, B. [Saskoil, Regina, Saskatchewan (Canada); Yager, D. [Tesco Drilling Tech., Calgary, Alberta (Canada)

    1993-11-01

    Economic analysis of a seven-well, long-reach horizontal drilling program into an unconsolidated, heavy-oil-bearing reservoir in Winter field near the Alberta/Saskatchewan border in Canada reveals that -- in the right application -- renting a portable top drive drilling system can reduce total drilling costs. Use of the portable top drive combined with other cost-saving measures enabled Saskoil, one of Canada`s larger independents, to drill more cheaply, on a cost-per-meter basis, in 1993 than in 1992. This was despite significant rental rates for drilling rigs and directional drilling services caused by increased demand in Western Canada. Total cost savings of 10% on wells that would otherwise cost in the (C) $500,000 range are believed realistic. Based on this year`s performance, Saskoil recommends top drive for the company`s future horizontal wells in this area. This article describes the operator`s horizontal well program, advantages of top drive in that program and how it was installed and applied. Estimated time savings for six wells, plus other ways top drive can cut costs and improve operations are discussed.

  11. Stress

    OpenAIRE

    Jensen, Line Skov; Lova, Lotte; Hansen, Zandra Kulikovsky; Schønemann, Emilie; Larsen, Line Lyngby; Colberg Olsen, Maria Sophia; Juhl, Nadja; Magnussen, Bogi Roin

    2012-01-01

    Stress er en tilstand som er meget omdiskuteret i samfundet, og dette besværliggør i en vis grad konkretiseringen af mulige løsningsforslag i bestræbelsen på at forebygge den såkaldte folkesygdom. Hovedkonklusionen er, at selv om der bliver gjort meget for at forebygge, er der ikke meget der aktivt kan sættes i værk for at reducere antallet af stressramte, før en fælles forståelse af stressårsager og effektiv stresshåndtering er fremlagt. Problemformuleringen er besvaret gennem en undersø...

  12. Combining stress transfer and source directivity: the case-study of the 2012 Emilia seismic sequence, Northern Italy

    Science.gov (United States)

    Convertito, V.; Catalli, F.; Emolo, A.

    2013-12-01

    The Emilia region in the Northern Italy was struck by a seismic sequence that started on May 19, 2012 May with a Mw 3.8 earthquake. It produced about 2100 events during the following month, affecting an area of about 60 km x 30 km elongated in the EW direction. It caused 17 casualties, severe damage to dwellings and forced the closure of several factories. The largest events (Mw 5.6 and 5.4) occurred on 20 May and 29 May, respectively, and were followed by 6 Mw>4.5 earthquakes over the next 2 weeks. We investigate potential mechanisms (both static and dynamic triggering) that may describe the evolution of the sequence. We consider rupture directivity in the dynamic strain field and observe that, for each main earthquake, its related aftershocks and the subsequent large event occurred in an area characterized by higher dynamic strains and corresponding to the dominant rupture direction associated with the previous earthquake. We find that static stress redistribution alone is not capable of explaining the locations of subsequent events and then the evolution of the seismic sequence. We conclude that dynamic triggering played a significant role in driving the sequence. This triggering was also associated with a variation in permeability and a pore pressure increase in an area characterized by a massive presence of fluids.

  13. Hydrodynamic optimization of membrane bioreactor by horizontal geometry modification using computational fluid dynamics.

    Science.gov (United States)

    Yan, Xiaoxu; Wu, Qing; Sun, Jianyu; Liang, Peng; Zhang, Xiaoyuan; Xiao, Kang; Huang, Xia

    2016-01-01

    Geometry property would affect the hydrodynamics of membrane bioreactor (MBR), which was directly related to membrane fouling rate. The simulation of a bench-scale MBR by computational fluid dynamics (CFD) showed that the shear stress on membrane surface could be elevated by 74% if the membrane was sandwiched between two baffles (baffled MBR), compared with that without baffles (unbaffled MBR). The effects of horizontal geometry characteristics of a bench-scale membrane tank were discussed (riser length index Lr, downcomer length index Ld, tank width index Wt). Simulation results indicated that the average cross flow of the riser was negatively correlated to the ratio of riser and downcomer cross-sectional area. A relatively small tank width would also be preferable in promoting shear stress on membrane surface. The optimized MBR had a shear elevation of 21.3-91.4% compared with unbaffled MBR under same aeration intensity. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Investigating biological traces of traumatic stress in changing societies: challenges and directions from the ESTSS Task Force on Neurobiology

    Directory of Open Access Journals (Sweden)

    Kathleen Thomaes

    2016-03-01

    Full Text Available Traumatic stress can have severe consequences for both mental and physical health. Furthermore, both psychological and biological traces of trauma increase as a function of accumulating traumatic experiences. Neurobiological research may aid in limiting the impact of traumatic stress, by leading to advances in preventive and treatment interventions. To promote the possibility for clinical implementation of novel research findings, this brief review describes timely conceptual and methodological challenges and directions in neurobiological trauma research on behalf of the Task Force “Neurobiology of Traumatic Stress” of the European Society for Traumatic Stress Studies (ESTSS. The most important conceptual challenges are the heterogeneity of disorders and existence of subtypes across diagnostic categories: differential latent profiles and trajectories regarding symptom expression and neural correlates are being unraveled; however, similar latent classes’ approaches for treatment response and neurobiological data remain scarce thus far. The key to improving the efficacy of currently available preventive interventions and treatments for trauma-related disorders lies in a better understanding and characterization of individual differences in response to trauma and interventions. This could lead to personalized treatment strategies for trauma-related disorders, based on objective information indicating whether individuals are expected to benefit from them. The most important methodological challenge identified here is the need for large consortia and meta-analyses or, rather, mega-analyses on existent data as a first step. In addition, large multicenter studies, combining novel methods for repeated sampling with more advanced statistical modeling techniques, such as machine learning, should aim to translate identified disease mechanisms into molecular blood-based biomarker combinations to predict disorder vulnerability and treatment responses.

  15. Rate limits in silicon sheet growth - The connections between vertical and horizontal methods

    Science.gov (United States)

    Thomas, Paul D.; Brown, Robert A.

    1987-01-01

    Meniscus-defined techniques for the growth of thin silicon sheets fall into two categories: vertical and horizontal growth. The interactions of the temperature field and the crystal shape are analyzed for both methods using two-dimensional finite-element models which include heat transfer and capillarity. Heat transfer in vertical growth systems is dominated by conduction in the melt and the crystal, with almost flat melt/crystal interfaces that are perpendicular to the direction of growth. The high axial temperature gradients characteristic of vertical growth lead to high thermal stresses. The maximum growth rate is also limited by capillarity which can restrict the conduction of heat from the melt into the crystal. In horizontal growth the melt/crystal interface stretches across the surface of the melt pool many times the crystal thickness, and low growth rates are achievable with careful temperature control. With a moderate axial temperature gradient in the sheet a substantial portion of the latent heat conducts along the sheet and the surface of the melt pool becomes supercooled, leading to dendritic growth. The thermal supercooling is surpressed by lowering the axial gradient in the crystal; this configuration is the most desirable for the growth of high quality crystals. An expression derived from scaling analysis relating the growth rate and the crucible temperature is shown to be reliable for horizontal growth.

  16. Stress-induced activation of protein kinase CK2 by direct interaction with p38 mitogen-activated protein kinase

    DEFF Research Database (Denmark)

    Sayed, M; Kim, S O; Salh, B S

    2000-01-01

    in the human cervical carcinoma HeLa cells by up to 8-fold, and this could be blocked by the p38 MAP kinase inhibitor SB203580. We show that p38alpha MAP kinase, in a phosphorylation-dependent manner, can directly interact with the alpha and beta subunits of CK2 to activate the holoenzyme through what appears......Protein kinase CK2 has been implicated in the regulation of a wide range of proteins that are important in cell proliferation and differentiation. Here we demonstrate that the stress signaling agents anisomycin, arsenite, and tumor necrosis factor-alpha stimulate the specific enzyme activity of CK2...... to be an allosteric mechanism. Furthermore, we demonstrate that anisomycin- and tumor necrosis factor-alpha-induced phosphorylation of p53 at Ser-392, which is important for the transcriptional activity of this growth suppressor protein, requires p38 MAP kinase and CK2 activities....

  17. Stress-induced indirect to direct band gap transition in β-FeSi2 nanocrystals embedded in Si

    Science.gov (United States)

    Shevlyagin, A. V.; Goroshko, D. L.; Chusovitin, E. A.; Balagan, S. A.; Dotsenko, S. A.; Galkin, K. N.; Galkin, N. G.; Shamirzaev, T. S.; Gutakovskii, A. K.; Iinuma, M.; Terai, Y.

    2017-09-01

    Embedded in silicon β-FeSi2 nanocrystals (NCs) were grown on Si(111) by solid phase epitaxy of a thin iron film followed by Si molecular beam epitaxy. After solid phase epitaxy, a mixture of β-FeSi2 and ɛ-FeSi nanocrystals is formed on the surface, sometimes β and ɛ phases coexist inside one nanocrystal. During initial stage of Si molecular beam epitaxy all ɛ-FeSi transforms into β-FeSi2. β-FeSi2 nanocrystals tend to move following Si growth front. By adjusting growth condition, we manage to prevent the nanocrystals from moving and to fabricate 7-layer n-Si(111)/β-FeSi2_NCs/p+-Si silicon heterostructure with embedded β-FeSi2 NCs. An epitaxial relationship and a stress induced in the nanocrystals by silicon matrix were found to be suitable for indirect to direct band gap transition in β-FeSi2. Of the heterostructure, a n-i-p avalanche photodetector and a light-emitting diode were formed. They have shown relatively good performance: ultrabroadband photoresponse from the visible (400 nm) to short-wavelength infrared (1800 nm) ranges owing to quantum-confined Stark effect in the nanocrystals and optical emission power of up to 25 µW at 9 A/cm2 with an external quantum efficiency of 0.009% at room temperature owing to a direct fundamental transition in stressed β-FeSi2 nanocrystals.

  18. DRILL BITS FOR HORIZONTAL WELLS

    Directory of Open Access Journals (Sweden)

    Paolo Macini

    1996-12-01

    Full Text Available This paper underlines the importance of the correct drill bit application in horizontal wells. Afler the analysis of the peculiarities of horizontal wells and drainholes drilling techniques, advantages and disadvantages of the application of both roller cone and fixed cutters drill bits have been discussed. Also, a review of the potential specific featuries useful for a correct drill bit selection in horizontal small diameter holes has been highlighted. Drill bits for these special applications, whose importance is quickly increasing nowadays, should be characterised by a design capable to deliver a good penetration rate low WOB, and, at the same time, be able to withstand high RPM without premature cutting structure failure and undergauge. Formation properties will also determine the cutting structure type and the eventual specific features for additional gauge and shoulder protection.

  19. Nuclear component horizontal seismic restraint

    Science.gov (United States)

    Snyder, Glenn J.

    1988-01-01

    A nuclear component horizontal seismic restraint. Small gaps limit horizontal displacement of components during a seismic occurrence and therefore reduce dynamic loadings on the free lower end. The reactor vessel and reactor guard vessel use thicker section roll-forged rings welded between the vessel straight shell sections and the bottom hemispherical head sections. The inside of the reactor guard vessel ring forging contains local vertical dovetail slots and upper ledge pockets to mount and retain field fitted and installed blocks. As an option, the horizontal displacement of the reactor vessel core support cone can be limited by including shop fitted/installed local blocks in opposing alignment with the reactor vessel forged ring. Beams embedded in the wall of the reactor building protrude into apertures in the thermal insulation shell adjacent the reactor guard vessel ring and have motion limit blocks attached thereto to provide to a predetermined clearance between the blocks and reactor guard vessel ring.

  20. Nurses’ Perceptions of Horizontal Violence

    Directory of Open Access Journals (Sweden)

    Rosemary Taylor

    2016-04-01

    Full Text Available In this article, I describe a study exploring horizontal violence and nurses’ perceptions of the phenomenon within the context of two 28-bed inpatient hospital units. The purpose of the study was to develop a clearer understanding of horizontal violence, incorporating observation and inquiry to identify the language nurses use to describe their experiences and factors in the nursing work environment that may perpetuate the phenomenon. Observation, review and analysis of policies, and interviews with staff were completed between June and November 2012. Thematic analysis resulted in five themes: (a behaviors are minimized and not recognized, (b fear inhibits all reporting, (c avoidance and isolation are coping strategies, (d lack of respect and support, and (e organizational chaos. The findings suggest future interventions must address a range of factors that perpetuate horizontal violence within the nursing work environment with consideration for the embeddedness and complexity of the phenomenon.

  1. Speckle Imaging Over Horizontal Paths

    Energy Technology Data Exchange (ETDEWEB)

    Carrano, C J

    2002-05-21

    Atmospheric aberrations reduce the resolution and contrast in surveillance images recorded over horizontal or slant paths. This paper describes our recent horizontal and slant path imaging experiments of extended scenes as well as the results obtained using speckle imaging. The experiments were performed with an 8-inch diameter telescope placed on either a rooftop or hillside and cover ranges of interest from 0.5 km up to 10 km. The scenery includes resolution targets, people, vehicles, and other structures. The improvement in image quality using speckle imaging is dramatic in many cases, and depends significantly upon the atmospheric conditions. We quantify resolution improvement through modulation transfer function measurement comparisons.

  2. Characteristic Value Method of Well Test Analysis for Horizontal Gas Well

    Directory of Open Access Journals (Sweden)

    Xiao-Ping Li

    2014-01-01

    Full Text Available This paper presents a study of characteristic value method of well test analysis for horizontal gas well. Owing to the complicated seepage flow mechanism in horizontal gas well and the difficulty in the analysis of transient pressure test data, this paper establishes the mathematical models of well test analysis for horizontal gas well with different inner and outer boundary conditions. On the basis of obtaining the solutions of the mathematical models, several type curves are plotted with Stehfest inversion algorithm. For gas reservoir with closed outer boundary in vertical direction and infinite outer boundary in horizontal direction, while considering the effect of wellbore storage and skin effect, the pseudopressure behavior of the horizontal gas well can manifest four characteristic periods: pure wellbore storage period, early vertical radial flow period, early linear flow period, and late horizontal pseudoradial flow period. For gas reservoir with closed outer boundary both in vertical and horizontal directions, the pseudopressure behavior of the horizontal gas well adds the pseudosteady state flow period which appears after the boundary response. For gas reservoir with closed outer boundary in vertical direction and constant pressure outer boundary in horizontal direction, the pseudopressure behavior of the horizontal gas well adds the steady state flow period which appears after the boundary response. According to the characteristic lines which are manifested by pseudopressure derivative curve of each flow period, formulas are developed to obtain horizontal permeability, vertical permeability, skin factor, reservoir pressure, and pore volume of the gas reservoir, and thus the characteristic value method of well test analysis for horizontal gas well is established. Finally, the example study verifies that the new method is reliable. Characteristic value method of well test analysis for horizontal gas well makes the well test analysis

  3. Release of program Win-Tensor 4.0 for tectonic stress inversion: statistical expression of stress parameters

    Science.gov (United States)

    Delvaux, D.

    2012-04-01

    The Win-Tensor program is an interactive computer program for fracture analysis and crustal stress reconstruction, freely distributed to the scientific and academic community and widely used by structural geologists. It was developed with a constant feed-back from the users and is regularly upgraded. Version 4.0 released in January 2012 provides as a new feature the standard deviation of the horizontal stress axes (SHmax/SHmin) and the stress regime Index R'. The latter expresses the relative stress magnitudes and the nature of the vertical stress in a continuous scale, ranging from 1 to 3. Computation of the standard deviations is based on the examination of all possible reduced stress tensors for a particular stress solution obtained from the inversion of fault-slip or focal mechanism data. They are defined by combining the possible values of each individual stress axes (sigma 1, sigma 2, sigma 3) and the stress ratio R = (sigma2-sigma3)/(sigma1-sigma3). For each possible reduced tensors, the horizontal paleostress directions (SHmax/SHmin) and regime (R') are computed and the related 1 sigma standard deviations determined. This way, the 4 dimensions of the reduced stress tensor are reduced to a two dimensional expression with is commonly used to depict the horizontal stress trajectories as in the World Stress Map project. This procedure has been implemented for the three different methods for reconstructing the reduced stress tensors in Win-Tensor: PBT Right Dihedron and Rotational Optimisation. The advantages of this statistical expression of stress parameters are demonstrated using practical examples. Win-Tensor program can be downloaded from the Tensor web site: http://www.damiendelvaux.be/Tensor/tensor-index.html

  4. Stressful life events, perceived stress, and 12-month course of geriatric depression: direct effects and moderation by the 5-HTTLPR and COMT Val158Met polymorphisms.

    Science.gov (United States)

    Zannas, Anthony S; McQuoid, Douglas R; Steffens, David C; Chrousos, George P; Taylor, Warren D

    2012-07-01

    Although the relation between stressful life events (SLEs) and risk of major depressive disorder is well established, important questions remain about the effects of stress on the course of geriatric depression. Our objectives were (1) to examine how baseline stress and change in stress is associated with course of geriatric depression and (2) to test whether polymorphisms of serotonin transporter (5-HTTLPR) and catechol-O-methyltransferase (COMT Val158Met) genes moderate this relation. Two-hundred and sixteen depressed subjects aged 60 years or older were categorized by remission status (Montgomery-Asberg depression rating scale≤6) at 6 and 12 months. At 6 months, greater baseline numbers of self-reported negative and total SLEs and greater baseline perceived stress severity were associated with lower odds of remission. At 12 months, only baseline perceived stress predicted remission. When we examined change in stress, 12-month decrease in negative SLEs and level of perceived stress were associated with improved odds of 12-month remission. When genotype data were included, COMT Val158Met genotype did not influence these relations. However, when compared with 5-HTTLPR L/L homozygotes, S allele carriers with greater baseline numbers of negative SLEs and with greater decrease in negative SLEs were more likely to remit at 12 months. This study demonstrates that baseline SLEs and perceived stress severity may influence the 12-month course of geriatric depression. Moreover, changes in these stress measures over time correlate with depression outcomes. 5-HTTLPR S carriers appear to be more susceptible to both the effects of enduring stress and the benefit of interval stress reduction.

  5. Stress.

    Science.gov (United States)

    Chambers, David W

    2008-01-01

    We all experience stress as a regular, and sometimes damaging and sometimes useful, part of our daily lives. In our normal ups and downs, we have our share of exhaustion, despondency, and outrage--matched with their corresponding positive moods. But burnout and workaholism are different. They are chronic, dysfunctional, self-reinforcing, life-shortening habits. Dentists, nurses, teachers, ministers, social workers, and entertainers are especially susceptible to burnout; not because they are hard-working professionals (they tend to be), but because they are caring perfectionists who share control for the success of what they do with others and perform under the scrutiny of their colleagues (they tend to). Workaholics are also trapped in self-sealing cycles, but the elements are ever-receding visions of control and using constant activity as a barrier against facing reality. This essay explores the symptoms, mechanisms, causes, and successful coping strategies for burnout and workaholism. It also takes a look at the general stress response on the physiological level and at some of the damage American society inflicts on itself.

  6. Some Considerations on Horizontal Displacement and Horizontal Displacement Coefficient B

    Directory of Open Access Journals (Sweden)

    Tajduś Krzysztof

    2015-12-01

    Full Text Available Mining-induced deformations of the ground surface and within the rock mass may pose danger not only for surface constructions but also for underground objects (e.g., tunnels, underground storages, garages, diverse types of pipelines, electric cables, etc. For a proper evaluation of hazard for surface and underground objects, such parameters as horizontal displacement and horizontal deformations, especially their maximum values, are of crucial importance. The paper is an attempt at a critical review of hitherto accomplished studies and state of the art of predicting horizontal displacement u, in particular the coefficient B, whose value allows determination of the value of maximum displacement if the value of maximum slope is known, or the value of maximum deformation if the value of maximum trough slope is recognized. Since the geodesic observations of fully developed subsidence troughs suggest that the value of the coefficient depends on the depth H, radius of main influences range r and properties of overburden rock, in particular the occurrence of sub-eras Paleogene and Neogene layers (old name: Quaternary and Tertiary with low strength parameters, therefore a formula is provided in the present paper allowing for the estimation of the influence of those factors on the value of coefficient B.

  7. Determining the Potential Role of Regional Stress on Preferential Flow and Transport at Pahute Mesa, Nevada National Security Site

    Science.gov (United States)

    Reeves, D. M.; Smith, K. D.; Parashar, R.; Kevin, H. M.

    2016-12-01

    Pahute Mesa is a structurally complex region on the Nevada National Security Site consisting of multiple calderas and faults associated with Basin and Range tectonics. Ground water flows primarily through fractured volcanic rocks in a northeast to southwest direction. Kilometer-scale tritium and plutonium migration from the Benham underground test suggests ground water velocities on the order of 50 m/yr. Regional stress may exert considerable control on the hydraulic properties of large faults and smaller fractures at Pahute Mesa. In-situ measurements of the stress field are sparse, and short period earthquake focal mechanisms are used in this study to delineate principal horizontal stress orientations. Overall, event depths and short period mechanisms in the Pahute Mesa area are often poorly constrained. Stress field inversion solutions from the earthquake focal mechanism data indicate that Pahute Mesa is within a transtensional faulting regime with a maximum horizontal stress direction ranging from N29°E to N63°E with an average of N42°E. This maximum horizontal stress trend is supported by breakout data from large diameter boreholes. A computer code that incorporates stress field inversion solutions is used to compute dilation and slip tendency metrics for digitized fault and caldera structural margin segments according to both average and space-varying horizontal stress directions. Faults with the highest dilation trend NE-SW for both average and space-varying stress field solutions, and are lowest for NW-SE structures. The distribution of slip tendency is similar with maximum values below that required for a critically stressed designation. This implies that the resolution of normal stress acting on fault planes in Pahute Mesa may play a larger role on fault permeability than shear stress within the modern stress field. Inflow locations along boreholes and a series of large-scale aquifer tests are currently being analyzed to investigate potential

  8. Direct Assessment of Wall Shear Stress by Signal Intensity Gradient from Time-of-Flight Magnetic Resonance Angiography.

    Science.gov (United States)

    Han, Kap-Soo; Lee, Sang Hyuk; Ryu, Han Uk; Park, Se-Hyoung; Chung, Gyung-Ho; Cho, Young I; Jeong, Seul-Ki

    2017-01-01

    The aim of the study was to calculate the arterial wall signal intensity gradient (SIG) from time-of-flight MR angiography (TOF-MRA) and represent arterial wall shear stress. We developed a new algorithm that uses signal intensity (SI) of a TOF-MRA to directly calculate the signal intensity gradient (SIG). The results from our phantom study showed that the TOF-MRA SIG could be used to distinguish the magnitude of blood flow rate as high (mean SIG ± SD, 2.2 ± 0.4 SI/mm for 12.5 ± 2.3 L/min) and low (0.9 ± 0.3 SI/mm for 8.5 ± 2.6 L/min) in vessels (p SIG values were highly correlated with various flow rates (β = 0.96, p SIG was greater than 0.8 in each section at the carotid artery (p SIG and thereby the WSS. Thus, the TOF-MRA SIG can provide clinicians with an accurate and efficient screening method for making rapid decisions on the risk of vascular disease for a patient in clinical practice.

  9. Investigation of gravity waves using horizontally resolved radial velocity measurements

    Science.gov (United States)

    Stober, G.; Sommer, S.; Rapp, M.; Latteck, R.

    2013-10-01

    The Middle Atmosphere Alomar Radar System (MAARSY) on the island of Andøya in Northern Norway (69.3° N, 16.0° E) observes polar mesospheric summer echoes (PMSE). These echoes are used as tracers of atmospheric dynamics to investigate the horizontal wind variability at high temporal and spatial resolution. MAARSY has the capability of pulse-to-pulse beam steering allowing for systematic scanning experiments to study the horizontal structure of the backscatterers as well as to measure the radial velocities for each beam direction. Here we present a method to retrieve gravity wave parameters from these horizontally resolved radial wind variations by applying velocity azimuth display and volume velocity processing. Based on the observations a detailed comparison of the two wind analysis techniques is carried out in order to determine the zonal and meridional wind as well as to measure first-order inhomogeneities. Further, we demonstrate the possibility to resolve the horizontal wave properties, e.g., horizontal wavelength, phase velocity and propagation direction. The robustness of the estimated gravity wave parameters is tested by a simple atmospheric model.

  10. Investigation of gravity waves using horizontally resolved radial velocity measurements

    Directory of Open Access Journals (Sweden)

    G. Stober

    2013-10-01

    Full Text Available The Middle Atmosphere Alomar Radar System (MAARSY on the island of Andøya in Northern Norway (69.3° N, 16.0° E observes polar mesospheric summer echoes (PMSE. These echoes are used as tracers of atmospheric dynamics to investigate the horizontal wind variability at high temporal and spatial resolution. MAARSY has the capability of pulse-to-pulse beam steering allowing for systematic scanning experiments to study the horizontal structure of the backscatterers as well as to measure the radial velocities for each beam direction. Here we present a method to retrieve gravity wave parameters from these horizontally resolved radial wind variations by applying velocity azimuth display and volume velocity processing. Based on the observations a detailed comparison of the two wind analysis techniques is carried out in order to determine the zonal and meridional wind as well as to measure first-order inhomogeneities. Further, we demonstrate the possibility to resolve the horizontal wave properties, e.g., horizontal wavelength, phase velocity and propagation direction. The robustness of the estimated gravity wave parameters is tested by a simple atmospheric model.

  11. Stress regimes in the northwest of Iran from stress inversion of earthquake focal mechanisms

    Science.gov (United States)

    Afra, Mahsa; Moradi, Ali; Pakzad, Mehrdad

    2017-11-01

    Northwestern Iran is one of the seismically active regions with a high seismic risk in the world. This area is a part of the complex tectonic system due to the interaction between Arabia, Anatolia and Eurasia. The purpose of this study is to deduce the stress regimes in the northwestern Iran and surrounding regions from stress inversion of earthquake focal mechanisms. We compile 92 focal mechanisms data from the Global CMT catalogue and other sources and also determine the focal mechanisms of 14 earthquakes applying the moment tensor inversion. We divide the studied region into 9 zones using similarity of the horizontal GPS velocities and existing focal mechanisms. We implement two stress inversion methods, Multiple Inverse Method and Iterative Joint Inversion Method, which provide comparable results in terms of orientations of maximum horizontal stress axes SHmax. The similar results of the two methods should make us more confident about the interpretations. We consider zones of exclusion surrounding all the earthquakes according to independent focal mechanisms hypothesis. The hypothesis says that the inversion should involve events that are far enough from each other in order that any previous event doesn't affect the stress field near the earthquake under consideration. Accordingly we deal with the matter by considering zones of exclusion around all the events. The result of exclusion is only significant for eastern Anatolia. The stress regime in this region changes from oblique to strike slip faulting because of the exclusion. In eastern Anatolia, the direction of maximum horizontal stress is nearly north-south. The direction alters to east-west in Talesh region. Errors of σ1 are lower in all zones comparing with errors of σ2 and σ3 and there is a trade-off between data resolution and covariance of the model. The results substantiate the strike-slip and thrust faulting stress regimes in the northwest of Iran.

  12. Horizontal and vertical resistance strength of infrazygomatic mini-implants.

    Science.gov (United States)

    Wu, J-H; Lu, P-C; Lee, K-T; Du, J-K; Wang, H-C; Chen, C-M

    2011-05-01

    This study assessed the adequacy of anchorage strength of infrazygomatic mini-implants in vertical and horizontal directions. Each brand of infrazygomatic mini-implant tested provided acceptable skeletal anchorage. Copyright © 2011 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

  13. Horizontal mantle flow controls subduction dynamics.

    Science.gov (United States)

    Ficini, E; Dal Zilio, L; Doglioni, C; Gerya, T V

    2017-08-08

    It is generally accepted that subduction is driven by downgoing-plate negative buoyancy. Yet plate age -the main control on buoyancy- exhibits little correlation with most of the present-day subduction velocities and slab dips. "West"-directed subduction zones are on average steeper (~65°) than "East"-directed (~27°). Also, a "westerly"-directed net rotation of the lithosphere relative to the mantle has been detected in the hotspot reference frame. Thus, the existence of an "easterly"-directed horizontal mantle wind could explain this subduction asymmetry, favouring steepening or lifting of slab dip angles. Here we test this hypothesis using high-resolution two-dimensional numerical thermomechanical models of oceanic plate subduction interacting with a mantle flow. Results show that when subduction polarity is opposite to that of the mantle flow, the descending slab dips subvertically and the hinge retreats, thus leading to the development of a back-arc basin. In contrast, concordance between mantle flow and subduction polarity results in shallow dipping subduction, hinge advance and pronounced topography of the overriding plate, regardless of their age-dependent negative buoyancy. Our results are consistent with seismicity data and tomographic images of subduction zones. Thus, our models may explain why subduction asymmetry is a common feature of convergent margins on Earth.

  14. Bi-directional effect of cholecystokinin receptor-2 overexpression on stress-triggered fear memory and anxiety in the mouse.

    Directory of Open Access Journals (Sweden)

    Qian Chen

    Full Text Available Fear, an emotional response of animals to environmental stress/threats, plays an important role in initiating and driving adaptive response, by which the homeostasis in the body is maintained. Overwhelming/uncontrollable fear, however, represents a core symptom of anxiety disorders, and may disturb the homeostasis. Because to recall or imagine certain cue(s of stress/threats is a compulsory inducer for the expression of anxiety, it is generally believed that the pathogenesis of anxiety is associated with higher attention (acquisition selectively to stress or mal-enhanced fear memory, despite that the actual relationship between fear memory and anxiety is not yet really established. In this study, inducible forebrain-specific cholecystokinin receptor-2 transgenic (IF-CCKR-2 tg mice, different stress paradigms, batteries of behavioral tests, and biochemical assays were used to evaluate how different CCKergic activities drive fear behavior and hormonal reaction in response to stresses with different intensities. We found that in IF-CCKR-2 tg mice, contextual fear was impaired following 1 trial of footshock, while overall fear behavior was enhanced following 36 trials of footshock, compared to their littermate controls. In contrast to a standard Yerkes-Dodson (inverted-U shaped stress-fear relationship in control mice, a linearized stress-fear curve was observed in CCKR-2 tg mice following gradient stresses. Moreover, compared to 1 trial, 36 trials of footshock in these transgenic mice enhanced anxiety-like behavior in other behavioral tests, impaired spatial and recognition memories, and prolonged the activation of adrenocorticotropic hormone (ACTH and glucocorticoids (CORT following new acute stress. Taken together, these results indicate that stress may trigger two distinctive neurobehavioral systems, depending on both of the intensity of stress and the CCKergic tone in the brain. A "threshold theory" for this two-behavior system has been

  15. Bi-Directional Effect of Cholecystokinin Receptor-2 Overexpression on Stress-Triggered Fear Memory and Anxiety in the Mouse

    Science.gov (United States)

    Chen, Qian; Tang, Mingxi; Mamiya, Takayoshi; Im, Heh-In; Xiong, Xiaoli; Joseph, Anu; Tang, Ya-Ping

    2010-01-01

    Fear, an emotional response of animals to environmental stress/threats, plays an important role in initiating and driving adaptive response, by which the homeostasis in the body is maintained. Overwhelming/uncontrollable fear, however, represents a core symptom of anxiety disorders, and may disturb the homeostasis. Because to recall or imagine certain cue(s) of stress/threats is a compulsory inducer for the expression of anxiety, it is generally believed that the pathogenesis of anxiety is associated with higher attention (acquisition) selectively to stress or mal-enhanced fear memory, despite that the actual relationship between fear memory and anxiety is not yet really established. In this study, inducible forebrain-specific cholecystokinin receptor-2 transgenic (IF-CCKR-2 tg) mice, different stress paradigms, batteries of behavioral tests, and biochemical assays were used to evaluate how different CCKergic activities drive fear behavior and hormonal reaction in response to stresses with different intensities. We found that in IF-CCKR-2 tg mice, contextual fear was impaired following 1 trial of footshock, while overall fear behavior was enhanced following 36 trials of footshock, compared to their littermate controls. In contrast to a standard Yerkes-Dodson (inverted-U shaped) stress-fear relationship in control mice, a linearized stress-fear curve was observed in CCKR-2 tg mice following gradient stresses. Moreover, compared to 1 trial, 36 trials of footshock in these transgenic mice enhanced anxiety-like behavior in other behavioral tests, impaired spatial and recognition memories, and prolonged the activation of adrenocorticotropic hormone (ACTH) and glucocorticoids (CORT) following new acute stress. Taken together, these results indicate that stress may trigger two distinctive neurobehavioral systems, depending on both of the intensity of stress and the CCKergic tone in the brain. A “threshold theory” for this two-behavior system has been suggested. PMID

  16. Panspermia and horizontal gene transfer

    Science.gov (United States)

    Klyce, Brig

    2009-08-01

    Evidence that extremophiles are hardy and ubiquitous is helping to make panspermia a respectable theory. But even if life on Earth originally came from space, biologists assume that the subsequent evolution of life is still governed by the darwinian paradigm. In this review we show how panspermia could amend darwinism and point to a cosmic source for, not only extremophiles but, all of life. This version of panspermia can be called "strong panspermia." To support this theory we will discuss recent evidence pertaining to horizontal gene transfer, viruses, genes apparently older than the Earthly evolution of the features they encode, and primate-specific genes without identifiable precursors.

  17. Shear stress affects the intracellular distribution of eNOS: Direct demonstration by a novel in vivo technique

    NARCIS (Netherlands)

    C. Cheng (Caroline (Ka Lai)); M.J. van Haperen (Rien); M.C. de Waard (Monique); L.C.A. van Damme (Luc); D. Tempel (Dennie); R. Hanemaaijer (Roeland); W.A. van Cappellen (Gert); J.A. Bos (Joop); C.J. Slager (Cornelis); D.J.G.M. Duncker (Dirk); A.F.W. van der Steen (Ton); M.P.G. de Crom (Rini); R. Krams (Rob)

    2005-01-01

    textabstractThe focal location of atherosclerosis in the vascular tree is correlated with local variations in shear stress. We developed a method to induce defined variations in shear stress in a straight vessel segment of a mouse. To this end, a cylinder with a tapered lumen was placed around the

  18. Evaluation of physiological stress in Australian wildlife: Embracing pioneering and current knowledge as a guide to future research directions.

    Science.gov (United States)

    Narayan, Edward J

    2017-04-01

    Australia has a rich terrestrial and marine biodiversity and high species endemism. However, the oceanic continent is facing the biodiversity extinction crisis. The primary factors are anthropogenic induced environmental changes, including wildlife habitat destruction through urbanisation and predation by feral animals (e.g. red foxes and feral cats), increased severity of diseases (e.g. chytridiomycosis and chlamydia), and increased occurrence of summer heat waves and bush fires. Stress physiology is a dynamic field of science based on the studies of endocrine system functioning in animals. The primary stress regulator is the hypothalamo-pituitary adrenal (interrenal) axis and glucocorticoids (corticosterone and/or cortisol) provide stress index across vertebrate groups. This review paper focuses on physiological stress assessments in Australian wildlife using examples of amphibians, reptiles, birds and marsupials. I provide a thorough discussion of pioneering studies that have shaped the field of stress physiology in Australian wildlife species. The main findings point towards key aspects of stress endocrinology research, such as quantification of biologically active levels of glucocorticoids, development of species-specific GC assays and applications of stress physiology approaches in field ecology and wildlife conservation programs. Furthermore, I also discuss the importance of chronic stress assessment in wildlife populations. Finally, I provide a conceptual framework presenting key research questions in areas of wildlife stress physiology research. In conclusion, wildlife management programs can immensely benefit from stress physiology assessments to gauge the impact of human interventions on wildlife such as species translocation and feral species eradication. Copyright © 2015 Elsevier Inc. All rights reserved.

  19. Biomechanical effects of two different collar implant structures on stress distribution under cantilever fixed partial dentures.

    Science.gov (United States)

    Merıç, Gökçe; Erkmen, Erkan; Kurt, Ahmet; Eser, Atilim; özden, Ahmet Utku

    2011-11-01

    The purpose of the study was to compare the effects of two distinct collar geometries of implants on stress distribution in the bone around the implants supporting cantilever fixed partial dentures (CFPDs) as well as in the implant-abutment complex and superstructures. The three-dimensional finite element method was selected to evaluate the stress distribution. CFPDs which was supported by microthread collar structured (MCS) and non-microthread collar structured (NMCS) implants was modeled; 300 N vertical, 150 N oblique and 60 N horizontal forces were applied to the models separately. The stress values in the bone, implant-abutment complex and superstructures were calculated. In the MCS model, higher stresses were located in the cortical bone and implant-abutment complex in the case of vertical load while decreased stresses in cortical bone and implant-abutment complex were noted within horizontal and oblique loading. In the case of vertical load, decreased stresses have been noted in cancellous bone and framework. Upon horizontal and oblique loading, a MCS model had higher stress in cancellous bone and framework than the NMCS model. Higher von Mises stresses have been noted in veneering material for NMCS models. It has been concluded that stress distribution in implant-supported CFPDs correlated with the macro design of the implant collar and the direction of applied force.

  20. The use of GPS horizontals for loading studies, with applications to northern California and southeast Greenland

    NARCIS (Netherlands)

    Wahr, J.; Khan, S.A.; van Dam, T.; Liu, Lin; van Angelen, J.H.|info:eu-repo/dai/nl/325922470; van den Broeke, M.R.|info:eu-repo/dai/nl/073765643; Meertens, C.M.

    2013-01-01

    We describe how GPS measurements of horizontal crustal motion can be used to augment vertical crustal motion measurements, to improve and extend GPS studies of surface loading. We show that the ratio of the vertical displacement to the horizontal displacement, combined with the direction of the

  1. Horizontal gene transfer in chromalveolates

    Directory of Open Access Journals (Sweden)

    Bhattacharya Debashish

    2007-09-01

    Full Text Available Abstract Background Horizontal gene transfer (HGT, the non-genealogical transfer of genetic material between different organisms, is considered a potentially important mechanism of genome evolution in eukaryotes. Using phylogenomic analyses of expressed sequence tag (EST data generated from a clonal cell line of a free living dinoflagellate alga Karenia brevis, we investigated the impact of HGT on genome evolution in unicellular chromalveolate protists. Results We identified 16 proteins that have originated in chromalveolates through ancient HGTs before the divergence of the genera Karenia and Karlodinium and one protein that was derived through a more recent HGT. Detailed analysis of the phylogeny and distribution of identified proteins demonstrates that eight have resulted from independent HGTs in several eukaryotic lineages. Conclusion Recurring intra- and interdomain gene exchange provides an important source of genetic novelty not only in parasitic taxa as previously demonstrated but as we show here, also in free-living protists. Investigating the tempo and mode of evolution of horizontally transferred genes in protists will therefore advance our understanding of mechanisms of adaptation in eukaryotes.

  2. Pre-sowing Seed Treatments in Direct-seeded Early Rice: Consequences for Emergence, Seedling Growth and Associated Metabolic Events under Chilling Stress

    Science.gov (United States)

    Wang, Weiqin; Chen, Qian; Hussain, Saddam; Mei, Junhao; Dong, Huanglin; Peng, Shaobing; Huang, Jianliang; Cui, Kehui; Nie, Lixiao

    2016-01-01

    Double direct-seeding for double rice cropping is a simplified, labor saving, and efficient cropping system to improve multiple-crop index and total rice production in central China. However, poor crop establishment of direct-seeded early rice due to chilling stress is the main obstacle to wide spread of this system. A series of experiments were conducted to unravel the effects of pre-sowing seed treatments on emergence, seedling growth and associated metabolic events of direct-seeded early rice under chilling stress. Two seed priming treatments and two seed coating treatments were used in all the experiments. A non-treated control treatment was also maintained for comparison. In both the field and growth chamber studies, seed priming with selenium or salicylic acid significantly enhanced the emergence and seedling growth of rice compared with non-treated control. Nevertheless, such positive effects were not apparent for seed coating treatments. Better emergence and vigorous seedling growth of rice after seed priming was associated with enhanced α-amylase activity, higher soluble sugars contents, and greater respiration rate in primed rice seedlings under chilling stress. Taking together, these findings may provide new avenues for understanding and advancing priming-induced chilling tolerance in direct-seeded early rice in double rice cropping system.

  3. Horizontal Shear Wave Imaging of Large Optics

    Energy Technology Data Exchange (ETDEWEB)

    Quarry, M J

    2007-09-05

    When complete the National Ignition Facility (NIF) will be the world's largest and most energetic laser and will be capable of achieving for the first time fusion ignition in the laboratory. Detecting optics features within the laser beamlines and sizing them at diameters of 0.1 mm to 10 mm allows timely decisions concerning refurbishment and will help with the routine operation of the system. Horizontally polarized shear waves at 10 MHz were shown to accurately detect, locate, and size features created by laser operations from 0.5 mm to 8 mm by placing sensors at the edge of the optic. The shear wave technique utilizes highly directed beams. The outer edge of an optic can be covered with shear wave transducers on four sides. Each transducer sends a pulse into the optic and any damage reflects the pulse back to the transmitter. The transducers are multiplexed, and the collected time waveforms are enveloped and replicated across the width of the element. Multiplying the data sets from four directions produces a map of reflected amplitude to the fourth power, which images the surface of the optic. Surface area can be measured directly from the image, and maximum depth was shown to be correlated to maximum amplitude of the reflected waveform.

  4. Direction of post-prandial ghrelin response associated with cortisol response, perceived stress and anxiety, and self-reported coping and hunger in obese women.

    Science.gov (United States)

    Sarker, Marjana R; Franks, Susan; Caffrey, James

    2013-11-15

    The neurobiological mechanisms modulating stress may share common pathways with appetite regulation and consequent obesity. The orexigenic hormone, ghrelin may moderate anxiety and stress-related eating behavior. This study was designed to investigate humoral (ghrelin, cortisol) and psychological/behavioral characteristics (subjective hunger, anxiety, and stress; eating behavior; coping ability) among obese subjects in a fasting state and after eating a standard meal. Subjects included 18 obese but otherwise healthy adult women. Subjects were divided into two groups based on the relative direction of ghrelin response to a standard meal. A meal mediated suppression in serum ghrelin (post/pre1.0) was designated as faulty ghrelin response (FG) (n=9). Ghrelin and cortisol responses were correlated, r(18)=0.558, p=.016. FG subjects had lower ratings of coping ability [t(2,16)=2.437, p=.027 and higher ratings of hunger cues in the expected direction [t(2,16)=-2.061, p=.056] compared to NG subjects. Meal mediated declines in subjective hunger were observed for both NG [t(1,8)=4.141, p=.003] and FG [t(1,8)=2.718, p=.026]. NG also showed declines in subjective anxiety [t(1,8)=2.977, p=.018], subjective stress [t(1,8)=2.321, p=.049], and cortisol [t(1,8)=4.214, p=.003]. In conclusion, changes in ghrelin, cortisol and selected psychological and behavioral indices are closely associated with one another suggesting that ghrelin may influence stress related eating and thus, the consequent observed relationship among stress, mood and obesity. Copyright © 2013 Elsevier B.V. All rights reserved.

  5. The horizontal planar structure of kinetic energy in a model vertical-axis wind turbine array

    Science.gov (United States)

    Craig, Anna; Zeller, Robert; Zarama, Francisco; Weitzman, Joel; Dabiri, John; Koseff, Jeffrey

    2013-11-01

    Recent studies have indicated that arrays of vertical axis wind turbines (VAWTs) could potentially harvest significantly more power per unit land area than arrays composed of conventional horizontal axis wind turbines. However, to design VAWT arrays for optimal power conversion, a more comprehensive understanding of inter-turbine energy transfer is needed. In the presented study, a geometrically scaled array of rotating circular cylinders is used to model a VAWT array. The horizontal inter-cylinder mean fluid velocities and Reynolds stresses are measured on several cross-sections using 2D particle image velocimetry in a flume. Two orientations of the array relative to the incoming flow are tested. The results indicate that cylinder rotation drives asymmetric mean flow patterns within and above the array, resulting in non-uniform distributions of turbulent kinetic energy. The variability is observed to be directly related to the ratio of the cylinder rotation speed to the streamwise water velocity. Emphasis is placed on the implications of the asymmetries for power production. Work supported by a Stanford Graduate Fellowship to A.E.C, by funding to J.O.D. from ONR N000141211047 and the Gordon and Betty Moore Foundation through Grant GBMF2645, and by funding from the Environmental Fluid Mechanics Laboratory, Stanford University.

  6. Horizontal gene transfer in choanoflagellates.

    Science.gov (United States)

    Tucker, Richard P

    2013-01-01

    Horizontal gene transfer (HGT), also known as lateral gene transfer, results in the rapid acquisition of genes from another organism. HGT has long been known to be a driving force in speciation in prokaryotes, and there is evidence for HGT from symbiotic and infectious bacteria to metazoans, as well as from protists to bacteria. Recently, it has become clear that as many as a 1,000 genes in the genome of the choanoflagellate Monosiga brevicollis may have been acquired by HGT. Interestingly, these genes reportedly come from algae, bacteria, and other choanoflagellate prey. Some of these genes appear to have allowed an ancestral choanoflagellate to exploit nutrient-poor environments and were not passed on to metazoan descendents. However, some of these genes are also found in animal genomes, suggesting that HGT into a common ancestor of choanozoans and animals may have contributed to metazoan evolution. Copyright © 2012 Wiley Periodicals, Inc.

  7. Hue geometry and horizontal connections.

    Science.gov (United States)

    Ben-Shahar, Ohad; Zucker, Steven W

    2004-01-01

    Primate visual systems support an elaborate specialization for processing color information. Concentrating on the hue component, we observe that, contrary to Mondrian-like assumptions, hue varies in a smooth manner for ecologically important natural imagery. To represent these smooth variations, and to support those information processing tasks that utilize hue, a piecewise smooth hue field is postulated. The geometry of hue-patch interactions is developed analogously to orientation-patch interactions in texture. The result is a model for long-range (horizontal) interactions in the color domain, the power of which is demonstrated on a number of examples. Implications for computer image processing, computer vision, visual neurophysiology and psychophysics are discussed.

  8. Explorando nuevos horizontes en NASA

    Science.gov (United States)

    Villanueva, G. L.

    A pesar de la incesante expansión del Universo iniciada con el Big Bang 14 mil millones de años atrás, nuestro Universo se siente cada día más cercano. La inquebrantable vocación de la humanidad por descubrir nuevos horizontes ha permitido el acercamiento de civilizaciones en nuestro planeta y nos ha permitido conocer nuestro lugar en el Universo como nunca antes. En este artículo presento una breve sinopsis de nuestro trabajo que se relaciona con diversas investigaciones con implicaciones astrobiológicas, desde el origen de los ingredientes de la "sopa de la vida", hasta la evolución y composición de la atmósfera de Marte.

  9. α-Tocopherol, ascorbic acid, and β-carotene protect against oxidative stress but reveal no direct influence on p53 expression in rats subjected to stress.

    Science.gov (United States)

    Wawrzyniak, Agata; Górnicka, Magdalena; Hamułka, Jadwiga; Gajewska, Małgorzata; Drywień, Małgorzata; Pierzynowska, Jolanta; Gronowska-Senger, Anna

    2013-10-01

    We hypothesized that α-tocopherol, ascorbic acid, and β-carotene, either applied individually or in combination, would modulate redox homeostasis and affect the regulation of genes involved in DNA repair under stress conditions. To test this hypothesis, we analyzed the influence of these vitamins, either supplied individually or in combination, on the plasma lipid peroxide level and the hepatic level of 8-hydroxy-2'-deoxyguanosine in rats. We also evaluated the expression of p53 and Mdm2 protein in the intestinal epithelium, as these proteins are involved in the cellular regulation of DNA damage repair. Male Wistar rats (n = 112) were supplemented with α-tocopherol (2 mg), ascorbic acid (12 mg), and β-carotene (1 mg), both individually and in combination, for 14 days; 32 control rats were treated with placebo. Half of the animals in each group (n = 8) were subjected to 15-minute treadmill running at 20 m/min to cause exercise-induced oxidative stress. A statistically significant reduction in lipid peroxide levels was observed in the plasma of rats subjected to exercise and given 2 or 3 of the antioxidants (P p53 protein expression were observed both in exercised and nonexercised animals, especially when the studied vitamins were administered in combination. Our findings suggest that α-tocopherol, ascorbic acid, and β-carotene, when given concurrently, have primarily antioxidant effects on lipids under stress but do not significantly affect the regulation of p53 gene expression. © 2013 Elsevier Inc. All rights reserved.

  10. Geopotential Stress

    DEFF Research Database (Denmark)

    Schiffer, Christian; Nielsen, S.B.

    Density heterogeneity in the Earth’s lithosphere causes lateral pressure variations. Horizontal gradients of the vertically integrated lithostatic pressure, the Geopotential Energy (GPE), are a source of stresses (Geopotential Stress) that contribute to the Earth’s Stress Field. In theory the GPE...... is linearly related to the lithospheric part of the Geoid. The Geopotential Stress can be calculated if either the density structure and as a consequence the GPE or the lithospheric contribution to the Geoid is known. The lithospheric Geoid is usually obtained by short pass filtering of satellite Geoid...... are not entirely suitable for the stress calculations but can be compiled and adjusted. We present an approach in which a global lithospheric density model based on CRUST2.0 is obtained by simultaneously fitting topography and surface heat flow in the presence of isostatic compensation and long-wavelength lateral...

  11. Effects of Nitrogen and Tensile Direction on Stress Corrosion Cracking Susceptibility of Ni-Free FeCrMnC-Based Duplex Stainless Steels.

    Science.gov (United States)

    Ha, Heon-Young; Lee, Chang-Hoon; Lee, Tae-Ho; Kim, Sangshik

    2017-03-15

    Stress corrosion cracking (SCC) behavior of Ni-free duplex stainless steels containing N and C (Fe balance -19Cr-8Mn-0.25C-(0.03, 0.21)N, in wt %) was investigated by using a slow strain rate test (SSRT) in air and aqueous NaCl solution with different tensile directions, including parallel (longitudinal) and perpendicular (transverse) to the rolling direction. It was found that alloying N was effective in increasing the resistance to SCC, while it was higher along the longitudinal direction than the transverse direction. The SCC susceptibility of the two alloys was assessed based on the electrochemical resistance to pitting corrosion, the corrosion morphology, and the fractographic analysis.

  12. Effects of Nitrogen and Tensile Direction on Stress Corrosion Cracking Susceptibility of Ni-Free FeCrMnC-Based Duplex Stainless Steels

    Directory of Open Access Journals (Sweden)

    Heon-Young Ha

    2017-03-01

    Full Text Available Stress corrosion cracking (SCC behavior of Ni-free duplex stainless steels containing N and C (Febalance-19Cr-8Mn-0.25C-(0.03, 0.21N, in wt % was investigated by using a slow strain rate test (SSRT in air and aqueous NaCl solution with different tensile directions, including parallel (longitudinal and perpendicular (transverse to the rolling direction. It was found that alloying N was effective in increasing the resistance to SCC, while it was higher along the longitudinal direction than the transverse direction. The SCC susceptibility of the two alloys was assessed based on the electrochemical resistance to pitting corrosion, the corrosion morphology, and the fractographic analysis.

  13. Evidence for extensive horizontal gene transfer from the draft genome of a tardigrade

    OpenAIRE

    Boothby, Thomas C.; Tenlen, Jennifer R.; Smith, Frank W.; Wang, Jeremy R; Patanella, Kiera A.; Osborne Nishimura, Erin; Tintori, Sophia C.; Li, Qing; Corbin D Jones; Yandell, Mark; Messina, David N.; Glasscock, Jarret; Goldstein, Bob

    2015-01-01

    Despite fascinating scientists for over 200 years, little at the molecular level is known about tardigrades, microscopic animals resistant to extreme stresses. We present the genome of a tardigrade. Approximately one-sixth of the genes in the tardigrade genome were found to have been acquired through horizontal transfer, a proportion nearly double the proportion of previous known cases of extreme horizontal gene transfer (HGT) in animals. Foreign genes have impacted the composition of the tar...

  14. Lexical processes in the recognition of Japanese horizontal and vertical compounds

    NARCIS (Netherlands)

    Miwa, K.; Dijkstra, A.F.J.

    2017-01-01

    This lexical decision eye-tracking study investigated whether horizontal and vertical readings elicit comparable behavioral patterns and whether reading directions modulate lexical processes. Response times and eye movements were recorded during a lexical decision task with Japanese bimorphemic

  15. Gas reservoir evaluation for underbalanced horizontal drilling

    National Research Council Canada - National Science Library

    Li Gao; Meng Ying-Feng; Wei Na; Xu Zhao-Yang; Li Hong-Tao; Xiao Gui-Lin; Zhang Yu-Rui

    2014-01-01

    .... Based on drilling operation parameters, well structure and monitored parameters, the wellbore pressure and the gas reservoir permeability could be predicted theoretically for underbalanced horizontal drilling...

  16. Composite Coiled Tubing for Extended Reach in Horizontal Oil Wells

    DEFF Research Database (Denmark)

    Costache, Andrei; Berggreen, Christian

    2017-01-01

    Conventional steel coiled tubing cannot reach along the entire length of very long horizontal oil wells. A lighter and more buoyant coiled tube is made possible using composite materials. The high stiffness to weight ratio of fiber reinforced polymers, coupled with a lower coefficient of friction......, has the potential of greatly extending the reach in horizontal oil wells. This study shows how to design composite coiled tubing and gives a comprehensive discussion about the most influential parameters. Several solutions, using glass-fiber and carbon are considered. Finite element models are used...... to calculate the buckling loads and the corresponding interlaminar stresses. The very positive results obtained during this study show that composite coiled tubing systems are vastly superior to their steel counterparts, and that in the future, these will become the new industry standard....

  17. Announcing the arrival of enrichment increases play behaviour and reduces weaning-stress-induced behaviours of piglets directly after weaning

    NARCIS (Netherlands)

    Dudink, S.; Simonse, H.; Marks, I.; Jonge, de F.H.; Spruijt, B.M.

    2006-01-01

    Piglets have difficulties with the abrupt changes at weaning associated with conventional pig production systems. Previously, it has been shown in rats that reward and announcement of reward counteracts impact of stress effects. In the present study, it was investigated if announcement of an

  18. Evidence for a Direct Link between Glutathione Biosynthesis and Stress Defense Gene Expression in ArabidopsisW⃞

    Science.gov (United States)

    Ball, Louise; Accotto, Gian-Paolo; Bechtold, Ulrike; Creissen, Gary; Funck, Dietmar; Jimenez, Ana; Kular, Baldeep; Leyland, Nicola; Mejia-Carranza, Jaime; Reynolds, Helen; Karpinski, Stanislaw; Mullineaux, Philip M.

    2004-01-01

    The mutant regulator of APX2 1-1 (rax1-1) was identified in Arabidopsis thaliana that constitutively expressed normally photooxidative stress-inducible ASCORBATE PEROXIDASE2 (APX2) and had ≥50% lowered foliar glutathione levels. Mapping revealed that rax1-1 is an allele of γ-GLUTAMYLCYSTEINE SYNTHETASE 1 (GSH1), which encodes chloroplastic γ-glutamylcysteine synthetase, the controlling step of glutathione biosynthesis. By comparison of rax1-1 with the GSH1 mutant cadmium hypersensitive 2, the expression of 32 stress-responsive genes was shown to be responsive to changed glutathione metabolism. Under photo-oxidative stress conditions, the expression of a wider set of defense-related genes was altered in the mutants. In wild-type plants, glutathione metabolism may play a key role in determining the degree of expression of defense genes controlled by several signaling pathways both before and during stress. This control may reflect the physiological state of the plant at the time of the onset of an environmental challenge and suggests that changes in glutathione metabolism may be one means of integrating the function of several signaling pathways. PMID:15308753

  19. Direct and Indirect Effects of Child Abuse and Environmental Stress: A Lifecourse Perspective on Adversity and Depressive Symptoms.

    Science.gov (United States)

    Sousa, Cindy; Mason, W Alex; Herrenkohl, Todd I; Prince, Dana; Herrenkohl, Roy C; Russo, M Jean

    2017-08-17

    There is a great deal of evidence about the mental health implications of physical child abuse and environmental stressors, or hardships that people experience at the household and neighborhood level (e.g., neighborhood violence; economic hardship, substance abuse, or conflict among family members). Yet, studies often focus on either abuse or environmental stress, not both, or examine abuse and environmental stressors as a combined set of experiences. Less is known, therefore, about how child abuse and environmental stress might work as either distinct or interrelated risks to diminish mental health over time. In this longitudinal study, we used path analyses to examine the cumulative effects of physical child abuse and environmental stressors on adult depressive symptoms among a sample of children followed into adulthood (N = 356). The goal was to assess whether chronic physical child abuse remains an independent predictor of adult outcomes once we accounted for the cumulative effects of household and neighborhood stressors across the lifecourse. Cumulative measures of physical child abuse and environmental stress each independently predicted a higher likelihood of adult depressive symptoms (ß = .122, p environmental stress on the relationship between cumulative physical abuse and adult depressive symptoms were marginally statistically significant. Results add to literature that examines child abuse, adversity, and lifecourse perspectives on health. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  20. Neuropeptide Y acts directly in the periphery on fat tissue and mediates stress-induced obesity and metabolic syndrome.

    Science.gov (United States)

    Kuo, Lydia E; Kitlinska, Joanna B; Tilan, Jason U; Li, Lijun; Baker, Stephen B; Johnson, Michael D; Lee, Edward W; Burnett, Mary Susan; Fricke, Stanley T; Kvetnansky, Richard; Herzog, Herbert; Zukowska, Zofia

    2007-07-01

    The relationship between stress and obesity remains elusive. In response to stress, some people lose weight, whereas others gain. Here we report that stress exaggerates diet-induced obesity through a peripheral mechanism in the abdominal white adipose tissue that is mediated by neuropeptide Y (NPY). Stressors such as exposure to cold or aggression lead to the release of NPY from sympathetic nerves, which in turn upregulates NPY and its Y2 receptors (NPY2R) in a glucocorticoid-dependent manner in the abdominal fat. This positive feedback response by NPY leads to the growth of abdominal fat. Release of NPY and activation of NPY2R stimulates fat angiogenesis, macrophage infiltration, and the proliferation and differentiation of new adipocytes, resulting in abdominal obesity and a metabolic syndrome-like condition. NPY, like stress, stimulates mouse and human fat growth, whereas pharmacological inhibition or fat-targeted knockdown of NPY2R is anti-angiogenic and anti-adipogenic, while reducing abdominal obesity and metabolic abnormalities. Thus, manipulations of NPY2R activity within fat tissue offer new ways to remodel fat and treat obesity and metabolic syndrome.

  1. Volume fracturing of deep shale gas horizontal wells

    Directory of Open Access Journals (Sweden)

    Tingxue Jiang

    2017-03-01

    Full Text Available Deep shale gas reservoirs buried underground with depth being more than 3500 m are characterized by high in-situ stress, large horizontal stress difference, complex distribution of bedding and natural cracks, and strong rock plasticity. Thus, during hydraulic fracturing, these reservoirs often reveal difficult fracture extension, low fracture complexity, low stimulated reservoir volume (SRV, low conductivity and fast decline, which hinder greatly the economic and effective development of deep shale gas. In this paper, a specific and feasible technique of volume fracturing of deep shale gas horizontal wells is presented. In addition to planar perforation, multi-scale fracturing, full-scale fracture filling, and control over extension of high-angle natural fractures, some supporting techniques are proposed, including multi-stage alternate injection (of acid fluid, slick water and gel and the mixed- and small-grained proppant to be injected with variable viscosity and displacement. These techniques help to increase the effective stimulated reservoir volume (ESRV for deep gas production. Some of the techniques have been successfully used in the fracturing of deep shale gas horizontal wells in Yongchuan, Weiyuan and southern Jiaoshiba blocks in the Sichuan Basin. As a result, Wells YY1HF and WY1HF yielded initially 14.1 × 104 m3/d and 17.5 × 104 m3/d after fracturing. The volume fracturing of deep shale gas horizontal well is meaningful in achieving the productivity of 50 × 108 m3 gas from the interval of 3500–4000 m in Phase II development of Fuling and also in commercial production of huge shale gas resources at a vertical depth of less than 6000 m.

  2. The stress field and its sources in the North Atlantic Realm and Europe

    DEFF Research Database (Denmark)

    Nielsen, S.B.; Schiffer, Christian; Stephenson, Randell Alexander

    in the convecting mantle cause mantle tractions at the base of the lithosphere. The radial component can cause dynamic topography and an anomalous state of lithospheric pressure, whereas the horizontal component might influence the plate movements directly. Relative plate movements and stress transmission through...... the rigid plates result in forces along plate boundaries. The relative importance and absolute magnitudes of the single stress sources is still matter of considerable discussion. Whereas the crustal structure is relatively well constrained for the estimation of the geopotential stress component...... and temperature variations at the base of the lithosphere that result in dynamic topography, and an anomalous geopotential energy. We do not include horizontal basal tractions or plate boundary forces. Nevertheless we can indirectly discuss the importance of additional stress sources for the lithospheric state...

  3. On the strength of oceanic fracture zones and their influence on the intraplate stress field

    Science.gov (United States)

    Bergman, Eric A.; Solomon, Sean C.

    1992-01-01

    We use the locations and source mechanisms of oceanic intraplate earthquakes to test the hypothesis that the strength of oceanic fracture zones is less than that of normal oceanic lithosphere. The 77 earthquakes selected for the study have well-determined focal mechanisms and epicenters in regions where fracture zones are well mapped. We have search for dependence of faulting style, fault orientation, or principal stress direction on the distance from the nearest fracture zone. If fracture zones were generally weaker than the surrounding lithosphere, one of the principal horizontal stresses would be oriented nearly perpendicular to the fracture zone; we find no evidence that principal stresses near fracture zones are oriented preferentially in this manner. There is a slight tendency for earthquakes to occur near fracture zones, and patterns of fault orientation and sense of slip support the view that differential cooling and horizontal contraction on fracture zones may contribute seismogenic stress.

  4. Horizontal vortex single chamber hydroturbine

    Directory of Open Access Journals (Sweden)

    Sergio Antonio Zarate-Orrego

    2016-01-01

    Full Text Available Se evaluó una máquina con alta resistencia de forma para extraer energía de una quebrada, río o corriente marina, y generar electricidad. Sin instrumentos adecuados, la investigación fue cualitativa. Se supuso que si aun así funcionaba, su comportamiento podía mejorar suavizándose la forma. El aparato tiene una tobera semi-convergente de paredes planas, una cámara de vórtice cilíndrica y un rodete. Capta agua por su sección mayor y la descarga tangencialmente por su sección menor en la cámara de vórtice; ésta tiene un orificio en una de sus paredes laterales. Así forma un vórtice horizontal que hace girar un rodete cuyo eje acciona un generador eléctrico. El trabajo experimental realizado mostró que sí es posible producir energía eléctrica con este dispositivo pese a las condiciones adversas en que se ensayó.

  5. HTGR core model response to simultaneous horizontal and vertical excitations

    Energy Technology Data Exchange (ETDEWEB)

    Bezler, P.; Curreri, J.R.

    1978-01-01

    An experimental program was undertaken to investigate the effects of simultaneous horizontal and vertical excitation on the response of the HTGR core. The tests were conducted with block array models of the core excited with both fixed frequency and sweeping frequency harmonic forcing functions. The effects on both free standing block arrays and on block arrays preloaded in the vertical direction were investigated. The results of the tests as well as their importance as regards to the full core response, are presented.

  6. A novel dataset on horizontal property rights in 126 jurisdictions

    OpenAIRE

    Dari-Mattiacci, Giuseppe; Guerriero, Carmine

    2017-01-01

    The law and the economy are deeply influenced by horizontal property rights, which are the rules regulating legal direct and indirect takings between private parties. To foster research on the determinants and impact of these institutions, we illustrate here a novel data set partially employed in (Dari-Mattiacci, Giuseppe, Carmine Guerriero, 2015; Dari-Mattiacci, Giuseppe, Carmine Guerriero, Zhenxing Huang, 2016) [3], [4], and (Guerriero Carmine, 2016) [6] and describing the acquisition of ow...

  7. A mechanical property and stress corrosion evaluation of VIM-ESR-VAR work strengthened and direct double aged Inconel 718 bar material

    Science.gov (United States)

    Montano, J. W.

    1986-01-01

    Presented are the mechanical properties and the stress corrosion resistance of triple melted vacuum induction melted (VIM), electro-slag remelted (ESR), and vacuum arc remelted (VAR), solution treated, work strengthened and direct double aged Inconel 718 alloy bars 4.00 in. (10.16) and 5.75 in. (14.60 cm) diameter. Tensile, charpy v-notched impact, and compact tension specimens were tested at ambient temperature in both the longitudinal and transverse directions. Longitudinal tensile and yield strengths in excess of 220 ksi (1516.85 MPa) and 200 ksi (1378.00 MPa) respectively, were realized at ambient temperature. Additional charpy impact and compact tension tests were performed at -100 F (-73 C). Longitudinal charpy impact strength equalled or exceeded 12.0 ft-lbs (16.3 Joules) at ambient and at -100 F(-73 C) while longitudinal compact (LC) tension fracture toughness strength remained above 79 ksi (86.80 MPa) at ambient and at -100 F(-73 C) temperatures. No failures occurred in the longitudinal or transverse tensile specimens stressed to 75 and 100 percent of their respective yield strengths and exposed to a salt fog environment for 180 days. Tensile tests performed after the stress corrosion test indicated no mechanical property degradation.

  8. Horizontal cooperation in logistics : Opportunities and impediments

    NARCIS (Netherlands)

    Cruijssen, Frans; Cools, Martine; Dullaert, Wout

    This paper presents the results of a large-scale survey on the potential benefits of and impediments for horizontal cooperation in Flanders. The main findings are that in general Logistics Service Providers strongly believe in the potential benefits of horizontal cooperation to increase their

  9. Rectifying Horizontal Inequalities: Lessons from African Conflict ...

    African Journals Online (AJOL)

    One of the most prevalent and underrepresented root causes of conflict in Africa and worldwide is that of horizontal inequalities. In that light, the goal of this paper is to provide practical solutions for the long-term resolution of conflict by addressing one of its root causes, that of horizontal inequalities. Reference will be made ...

  10. Rectifying Horizontal Inequalities: Lessons from African Conflict

    African Journals Online (AJOL)

    and horizontal (between groups) inequalities. A number of scholars have addressed the question of inequalities. Frances Stewart, for example, deals with the problem of horizontal inequalities in a number of papers.2 Stewart. (2002:3) argues that 'unequal access to political/economic/social resources. 1 The social contract ...

  11. The Process of Horizontal Differentiation: Two Models.

    Science.gov (United States)

    Daft, Richard L.; Bradshaw, Patricia J.

    1980-01-01

    Explores the process of horizontal differentiation by examining events leading to the establishment of 30 new departments in five universities. Two types of horizontal differentiation processes--administrative and academic--were observed and each was associated with different organizational conditions. (Author/IRT)

  12. Direct and indirect effects of parent stress on child obesity risk and added sugar intake in a sample of Southern California adolescents.

    Science.gov (United States)

    Shonkoff, Eleanor T; Dunton, Genevieve F; Chou, Chih-Ping; Leventhal, Adam M; Bluthenthal, Ricky; Pentz, Mary Ann

    2017-12-01

    Research indicates that children are at higher risk for obesity if their parents have been exposed to a larger number of stressors, yet little is known about effects of parents' subjective, perceived experience of stress on children's eating behaviours and adiposity and whether weight-related parenting practices (i.e. parent rules and positive family meal practices) mediate this relationship. The present study evaluated the direct and mediated relationship between parent perceived stress and child waist circumference and parent stress and child consumption of added sugars one year later. Longitudinal panel data. Eleven communities in Southern California, USA. Data were collected over two waves from parent-child dyads (n 599). Most parents were female (81 %) and Hispanic (51 %); children were 11 years old on average (sd 1·53; range 7-15 years) and 31 % received free school lunch. Perceived parent stress was not significantly associated with child waist circumference or consumption of added sugars one year later, and mediating pathways through parenting practices were not significant. However, parent rules were significantly associated with lower child consumption of added sugars (β=-0·14, Pchild consumption of added sugars but not necessarily lead to changes in obesity risk. Parent- and family-based interventions that support development of healthy rules about child eating have the potential to improve child dietary nutrient intake.

  13. RETRACTED: Rift-related active fault-system and a direction of maximum horizontal stress in the Cairo-Suez district, northeastern Egypt: A new approach from EMR-Technique and Cerescope data

    Science.gov (United States)

    Hagag, Wael; Obermeyer, Hennes

    2016-09-01

    This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal). This article has been retracted at the request of Editor-in-Chief Read Mapeo in agreement with Editor-in-Chief Damien Delvaux. The authors have plagiarized part of the following papers. The introduction and methodology sections of the paper are similar and in places slightly modified versions of the abstract, introduction and sections 2.4.2.1 and 2.4.2.2 of the PhD Thesis of Michael Krumbholz (2010) https://ediss.uni-goettingen.de/handle/11858/00-1735-0000-0006-B2EB-A. Text from the sections of introduction, methodology and "EMR-measurements in the Cairo-Suez district" is found also in the paper "Detection of active faults using EMR-Technique and Cerescope at Landau area in central Upper Rhine Graben, SW Germany" that was published by the authors in the Journal of Applied Geophysics 124 (2016) 117-129 http://dx.doi.org/10.1016/j.jappgeo.2015.11.019. One of the conditions of submission of a paper for publication is that authors declare explicitly that their work is original and has not appeared in a publication elsewhere. Re-use of any data should be appropriately cited. As such this article represents a severe abuse of the scientific publishing system. The scientific community takes a very strong view on this matter and apologies are offered to readers of the journal that this was not detected during the submission process.

  14. Horizontal gene transfer in human pathogens.

    Science.gov (United States)

    Juhas, Mario

    2015-02-01

    Horizontal gene transfer has a tremendous impact on the genome plasticity, adaptation and evolution of bacteria. Horizontally transferred mobile genetic elements are involved in the dissemination of antibiotic resistance and virulence genes, thus contributing to the emergence of novel "superbugs". This review provides update on various mechanisms of horizontal gene transfer and examines how horizontal gene transfer contributes to the evolution of pathogenic bacteria. Special focus is paid to the role horizontal gene transfer plays in pathogenicity of the emerging human pathogens: hypervirulent Clostridium difficile and Escherichia coli (including the most recent haemolytic uraemic syndrome outbreak strain) and methicillin-resistant Staphylococcus aureus (MRSA), which have been associated with largest outbreaks of infection recently.

  15. Direct and Indirect Selection for Forage Yield and Its Components in Sainfoin under Normal and Drought Stress Conditions

    Directory of Open Access Journals (Sweden)

    M. M. Majidi

    2014-08-01

    Full Text Available Selection based on indices is an effective method for breeding complex traits. To assess the efficiency of different selection methods, twenty one accessions of Sainfoin (Onobrychis viciifolia were evaluated in two environments including drought stress and non-stress conditions according to a randomized complete block design with three replications in 2010. In this study, the selection indices of Smith-Hazel and Pesek-Baker were determined based on the percentage of dry matter yield, stem percent, plant height and number of stem per plant under both conditions. Also response to selection and relative selection efficiency were estimated for studied traits and dry matter yield. The highest estimated selection efficiency for genetically improvement of dry matter yield was obtained via selection for stem percent and number of stem per plant. Therefore, these traits can be used as an appropriate selection criterion for improvement of forage yield. In Smith-Hazel indices under normal environment plant height and under stress environment stem percent had the highest gain, while in Pesek-Baker index, under both moisture conditions percentage of dry matter yield had the highest gain. The results indicated that Smith-Hazel index 1 had the most selection efficiency and could be used in sainfoin breeding programs.

  16. Stress controlled pulsed direct current co-sputtered Al1−xScxN as piezoelectric phase for micromechanical sensor applications

    Directory of Open Access Journals (Sweden)

    Simon Fichtner

    2015-11-01

    Full Text Available Scandium alloyed aluminum nitride (Al1−xScxN thin films were fabricated by reactive pulsed direct current co-sputtering of separate scandium and aluminum targets with x ≤ 0.37. A significant improvement of the clamped transversal piezoelectric response to strain e31,f from −1.28 C/m2 to −3.01 C/m2 was recorded, while dielectric constant and loss angle remain low. Further, the built-in stress level of Al1−xScxN was found to be tuneable by varying pressure, Ar/N2 ratio, and Sc content. The thus resulting enhancement of the expectable signal to noise ratio by a factor of 2.1 and the ability to control built-in stress make the integration of Al1−xScxN as the piezoelectric phase of micro-electro-mechanical system sensor applications highly attractive.

  17. Horizontal drilling pilot in a shallow heavy oil reservoir in the Suplac Field in Northwestern Romania

    Energy Technology Data Exchange (ETDEWEB)

    Lavelle, J.; Yaghoobi, A. [OMV Petrom S.A. (Romania)

    2011-07-01

    The Suplac field situated in north-western Romania is a shallow and heavy oil deposit lying at depths of between 40 and 200 meters. The deposit has been exploited since 1964 using different techniques but some areas of the reservoir located beneath villages and steep hills were never reached. The aim of this paper is to describe a project using horizontal alternating steam drive (HASD) to harvest oil from these areas by turning from vertical to horizontal. A pilot test was conducted over 4 months in 2010 with 3 parallel horizontal wells. The rig equipment, the well path designs and the directional difficulties are discussed herein. Results showed that horizontals could be drilled using a vertical mast rig and all the expectations were met. The success of this pilot project was highlighted herein and the company is now planning on continuing with a horizontal development program; however wellbore clean out is a remaining challenge.

  18. Simulations and scaling of horizontal convection

    Directory of Open Access Journals (Sweden)

    Mehmet ILIcak

    2012-05-01

    Full Text Available In this paper we describe the results of various numerical simulations of sideways or horizontal convection. Specifically, a two-dimensional Boussinesq fluid is both heated and cooled from its upper surface, but the walls and the bottom of the tank are insulating and have no flux of heat through them. We perform experiments with a range of Rayleigh numbers up to 1011, obtained by systematically reducing the diffusivity. We also explore the effects of a nonlinear equation of state and of a mechanical force imposed on the top surface at a fixed Rayleigh number. We find that, when there is no mechanical forcing, both the energy dissipation and the strength of the circulation itself monotonically fall with decreasing diffusivity. At Rayleigh numbers greater than 1010 the flow is unsteady; however, the eddying flow is still much weaker than the steady flow at smaller Rayleigh numbers. At high Rayleigh numbers, the stratification and the mean circulation are increasingly confined to a thin layer at the upper surface, with the layer thickness decreasing according to Ra−1/5. There is no evidence that the flow ever enters a regime that is independent of Rayleigh number. Using a nonlinear equation of state makes little difference to the flow phenomenology at a moderate Rayleigh number. The addition of an imposed stress at the upper surface makes a significant difference in the flow. A strong, energy-dissipating circulation can be maintained even at Ra = 109, and the stratification extends more deeply into the fluid than in the unstressed case. Overall, our results are consistent with the notion that in the absence of mechanical forcing a fluid that is heated and cooled from above cannot maintain a deep stratification or a strong sustained flow at high Rayleigh numbers, even if the interior flow is unsteady.

  19. The use of parabolic variations and the direct determination of stress intensity factors using the BIE method. [Boundary Integral Equation

    Science.gov (United States)

    Mendelson, A.

    1977-01-01

    Two advances in the numerical techniques of utilizing the BIE method are presented. The boundary unknowns are represented by parabolas over each interval which are integrated in closed form. These integrals are listed for easy use. For problems involving crack tip singularities, these singularities are included in the boundary integrals so that the stress intensity factor becomes just one more unknown in the set of boundary unknowns thus avoiding the uncertainties of plotting and extrapolating techniques. The method is applied to the problems of a notched beam in tension and bending, with excellent results.

  20. Semi-analytical representation of the activation level in stress fibre directions as alternative to the angular representation in the bio-chemo-mechanical model for cell contractility.

    Science.gov (United States)

    Bahls, Christian Rüdiger; Truong, Duy; Rienen, Ursula van

    2018-01-01

    The bio-chemo-mechanical model has many applications in modelling cell contractility. In simulations this model usually is coupled to the continuum mechanics of the cell by defining a large number of directions for stress fibres at each point. In this paper, another representation for coupling the biochemical processes in the bio-chemo-mechanical model is introduced. Using a quadratic form to represent the angular dependency of the activation level, the model's number of degrees of freedom is significantly reduced. Numerical results similar to the original representation are obtained while a significant improvement in computation time is achieved. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Study on the abrasion property of the anvil inside a hydraulic DTH hammer fitted with horizontal oriented sliders

    Directory of Open Access Journals (Sweden)

    J. He

    2017-10-01

    Full Text Available Hydraulic hammers have been extensively applied to horizontal directional well drilling in hard rock formations. However, the service life of a hydraulic hammer is still unsatisfactory due to the heavy wear or abrasion of the horizontal anvil, which leads to the failure and the reduction of service life in directional well drilling. In order to improve the performance life of a hydraulic hammer, the new type of anvil with a horizontal oriented slider has been designed. The abrasion property of the horizontal oriented slider have been numerically simulated and analyzed by Finite Element Analysis. Simulation and experimental results have shown that the abrasion rate exponentially varies with the mass of the anvil and the friction coefficient of horizontal oriented slider, nevertheless the abrasion rate of horizontal anvil is almost logarithmically varies with moving velocity of oriented slider. The maximum abrasion rate of horizontal oriented sliders will exceed 4% while moving velocity of the horizontal anvil is larger than 3m/s. While the mass of the anvil is 100kg, the maximum abrasion rate of horizontal oriented slider is 7.5?. However, the maximum abrasion rate of a horizontal oriented slider will be up to 16.5% while the friction coefficient is more than 0.2

  2. Stress-induced lipids are unsuitable as a direct biodiesel feedstock: a case study with Chlorella pyrenoidosa.

    Science.gov (United States)

    Shekh, Ajam Yakub; Shrivastava, Preeti; Krishnamurthi, Kannan; Mudliar, Sandeep N; Devi, Sivanesan Saravana; Kanade, Gajanan S; Lokhande, Satish K; Chakrabarti, Tapan

    2013-06-01

    The effects of various stresses on the suitability of lipid synthesized by Chlorella pyrenoidosa for biodiesel production were investigated. Lipids were characterized for detailed fatty acid methyl ester profiling and biodiesel properties like cetane number (CN), iodine value, cold filter plugging point (CFPP). Maximum biomass productivity (106.63 mgL(-1)d(-1)) and lipid content (29.68%) were obtained at indoor cultivation (nitrate sufficient, pH 8-10, 24h illumination). However, compared to this condition, other nitrate sufficient cultures [pH 6-8 and 10-12 (24h illumination), and at ambient CO2 and 16:8h light:dark photoperiod (pH unadjusted)] showed ∼12-14% lower lipid productivity. Upon 50% nitrate depletion (at indoor and outdoor; pH unadjusted) lipid content has increased by 7.62% and 17%, respectively. Though stress conditions helped enhancing lipid accumulation, there was two-fold increase in PUFA content compared to that observed at pH 8-10. This resulted in fuel properties which did not comply with the biodiesel standards. Copyright © 2013 Elsevier Ltd. All rights reserved.

  3. Integrated In Situ Stress Estimation by Hydraulic Fracturing, Borehole Observations and Numerical Analysis at the EXP-1 Borehole in Pohang, Korea

    Science.gov (United States)

    Kim, Hanna; Xie, Linmao; Min, Ki-Bok; Bae, Seongho; Stephansson, Ove

    2017-12-01

    It is desirable to combine the stress measurement data produced by different methods to obtain a more reliable estimation of in situ stress. We present a regional case study of integrated in situ stress estimation by hydraulic fracturing, observations of borehole breakouts and drilling-induced fractures, and numerical modeling of a 1 km-deep borehole (EXP-1) in Pohang, South Korea. Prior to measuring the stress, World Stress Map (WSM) and modern field data in the Korean Peninsula are used to construct a best estimate stress model in this area. Then, new stress data from hydraulic fracturing and borehole observations is added to determine magnitude and orientation of horizontal stresses. Minimum horizontal principal stress is estimated from the shut-in pressure of the hydraulic fracturing measurement at a depth of about 700 m. The horizontal stress ratios ( S Hmax/ S hmin) derived from hydraulic fracturing, borehole breakout, and drilling-induced fractures are 1.4, 1.2, and 1.1-1.4, respectively, and the average orientations of the maximum horizontal stresses derived by field methods are N138°E, N122°E, and N136°E, respectively. The results of hydraulic fracturing and borehole observations are integrated with a result of numerical modeling to produce a final rock stress model. The results of the integration give in situ stress ratios of 1.3/1.0/0.8 ( S Hmax/ S V/ S hmin) with an average azimuth of S Hmax in the orientation range of N130°E-N136°E. It is found that the orientation of S Hmax is deviated by more than 40° clockwise compared to directions reported for the WSM in southeastern Korean peninsula.

  4. Daylighting provided by horizontal openings using the illumination vector

    Energy Technology Data Exchange (ETDEWEB)

    Navarro, J.; Sendra, J.J. [Instituto Universitario de Ciencias de la Construccion, Universidad de Sevilla (Spain)

    2006-12-15

    Stemming from the expressions of the illumination vector provided by vertical openings at any point of the interior space, this article proposes and solves the equivalent expressions for openings in horizontal planes, thus completing the expressions of Navarro [Sobre iluminacion natural en arquitectura. Ed. Secretariado de Publicaciones de la Universidad de Sevilla; 1983] and offering algorithms which give the value of the illumination vector for CIE skies [Natural daylight official recommendations. Paris: CIE COMMITE 3.2.; 1955] at any point of the interior space and for any size of window whether vertical or horizontal. This constitutes a highly potential tool of computerized calculation of the direct component of natural illumination which is eminently more flexible and precise than those systems which are based on finite elements. (author)

  5. Recompletion by horizontal drilling pays off

    Energy Technology Data Exchange (ETDEWEB)

    Holifield, R.H.; Rehm, B.

    1989-03-01

    More than 20 wells have been recompleted in the Giddings field by drilling a new, horizontal interval from existing 5 1/2-in. cased wells for distances of 300 to 1,250 ft. Recompleting existing wells is much cheaper than drilling a new well. Plus, the new completions, overall, produce better. The horizontal wells are routinely profitable now, and pay out occurs in 3 to 24 months. During this program, the techniques for slim-hole- medium-radius, horizontal drilling in Giddings have been mastered and costs have dropped 75%. It is believed that this program may be the first (or among the first) continuing horizontal project drilled out of cased wells with repeatable profitability as opposed to projected viability.

  6. Productivity and injectivity of horizontal wells

    Energy Technology Data Exchange (ETDEWEB)

    Aziz, Khalid

    2000-03-06

    One of the key issues addressed was pressure drop in long horizontal wells and its influence on well performance. Very little information is available in the literature on flow in pipes with influx through pipe walls. Virtually all of this work has been in small diameter pipes and with single-phase flow. In order to address this problem new experimental data on flow in horizontal and near horizontal wells have been obtained. Experiments were conducted at an industrial facility on typical 6 1/8 ID, 100 feet long horizontal well model. The new data along with available information in the literature have been used to develop new correlations and mechanistic models. Thus it is now possible to predict, within reasonable accuracy, the effect of influx through the well on pressure drop in the well.

  7. Stress magnitudes in the crust: constraints from stress orientation and relative magnitude data

    Science.gov (United States)

    Zoback, M.L.; Magee, M.

    1991-01-01

    The World Stress Map Project is a global cooperative effort to compile and interpret data on the orientation and relative magnitudes of the contemporary in situ tectonic stress field in the Earth's lithosphere. The intraplate stress field in both the oceans and continents is largely compressional with one or both of the horizontal stresses greater than the vertical stress. The regionally uniform horizontal intraplate stress orientations are generally consistent with either relative or absolute plate motions indicating that plate-boundary forces dominate the stress distribution within the plates. Current models of stresses due to whole mantle flow inferred from seismic topography models predict a general compressional stress state within continents but do not match the broad-scale horizontal stress orientations. The broad regionally uniform intraplate stress orientations are best correlated with compressional plate-boundary forces and the geometry of the plate boundaries. -from Authors

  8. Thin section casting program. Volume 2: Horizontal TSC (Thin-Section Casting) approach

    Science.gov (United States)

    1989-01-01

    In horizontal thin-section casting (HTSC), 1-inch-thick steel sections are produced at speeds up to 600 ipm or about 60 tons per hour per foot of width (tphf). Liquid steel is fed from the ladle, and flows through a specially designed tundish, then flows through a refractory feeding tube and nozzle, with approximately the same external dimensions as the cast section, into a near-horizontal rectangular mold whose all four sides are traveling in the same direction and speed as the steel casting. This report is the second of a six volume set on thin section casting. This volume covers the research on horizontal thin section casting (TSC).

  9. Exploration of horizontal intrinsic spin resonances with two partial Siberian snakes

    Directory of Open Access Journals (Sweden)

    F. Lin

    2007-04-01

    Full Text Available Two partial Siberian snakes were used to avoid all the spin imperfection and vertical intrinsic resonances in the alternating gradient synchrotron (AGS at Brookhaven National Laboratory. However, the horizontal betatron motion can cause polarization loss resulting from the nonvertical stable spin direction in the presence of two partial snakes. This type of resonance, called a horizontal intrinsic spin resonance, was observed and systematically studied in the AGS. A simplified analytic model and numerical simulation have been developed to compare with experimental data. Properties of the horizontal intrinsic resonance are discussed.

  10. Mud peeling and horizontal crack formation in drying clays

    KAUST Repository

    Style, Robert W.

    2011-03-01

    Mud peeling is a common phenomenon whereby horizontal cracks propagate parallel to the surface of a drying clay. Differential stresses then cause the layer of clay above the crack to curl up to form a mud peel. By treating the clay as a poroelastic solid, we analyze the peeling phenomenon and show that it is caused by the gradient in tensile stress at the surface of the clay, analogously to the spalling of thermoelastic materials. For a constant water evaporation rate at the clay surface we derive equations for the depth of peeling and the time of peeling as functions of the evaporation rate. Our model predicts a simple relationship between the radius of curvature of a mud peel and the depth of peeling. The model predictions are in agreement with the available experimental data. Copyright 2011 by the American Geophysical Union.

  11. Horizontal Compilations of Nuclear Data III

    Science.gov (United States)

    Soroko, Z. N.; Sukhoruchkin, S. I.; Sukhoruchkin, D. S.

    2001-11-01

    Compilations of resonance parameters for all nuclei (horizontal-type compilations) derived from study of reactions with neutrons and charge particles are described. Systematic trends in experimental data due to the differences in energy scales of spectrometers were found after comparison of data for many nuclei. The combination of data from horizontal-type compilations with data from the well-known file ENSDF expands the usefulness of these data files.

  12. Horizontal Brand Extension and Customer perception

    OpenAIRE

    Khan, Khalid; Janthimapornkij, Rattanawilai

    2011-01-01

    Company use different method for extended their business to different market and to different segment. They use different method; brand extension is one of popular strategy for extension of business. Brand extension does not become successful for every brand, it is very risky. The purpose of this thesis is to study horizontal brand extension and customer perception. We will discuss horizontal brand extension and its two main types franchise brand extension and line extension. Brand extension ...

  13. Stress field models from Maxwell stress functions: southern California

    Science.gov (United States)

    Bird, Peter

    2017-08-01

    The lithospheric stress field is formally divided into three components: a standard pressure which is a function of elevation (only), a topographic stress anomaly (3-D tensor field) and a tectonic stress anomaly (3-D tensor field). The boundary between topographic and tectonic stress anomalies is somewhat arbitrary, and here is based on the modeling tools available. The topographic stress anomaly is computed by numerical convolution of density anomalies with three tensor Green's functions provided by Boussinesq, Cerruti and Mindlin. By assuming either a seismically estimated or isostatic Moho depth, and by using Poisson ratio of either 0.25 or 0.5, I obtain four alternative topographic stress models. The tectonic stress field, which satisfies the homogeneous quasi-static momentum equation, is obtained from particular second derivatives of Maxwell vector potential fields which are weighted sums of basis functions representing constant tectonic stress components, linearly varying tectonic stress components and tectonic stress components that vary harmonically in one, two and three dimensions. Boundary conditions include zero traction due to tectonic stress anomaly at sea level, and zero traction due to the total stress anomaly on model boundaries at depths within the asthenosphere. The total stress anomaly is fit by least squares to both World Stress Map data and to a previous faulted-lithosphere, realistic-rheology dynamic model of the region computed with finite-element program Shells. No conflict is seen between the two target data sets, and the best-fitting model (using an isostatic Moho and Poisson ratio 0.5) gives minimum directional misfits relative to both targets. Constraints of computer memory, execution time and ill-conditioning of the linear system (which requires damping) limit harmonically varying tectonic stress to no more than six cycles along each axis of the model. The primary limitation on close fitting is that the Shells model predicts very sharp

  14. Stress analysis of different prosthesis materials in implant-supported fixed dental prosthesis using 3D finite element method

    Directory of Open Access Journals (Sweden)

    Pedram Iranmanesh

    2014-01-01

    Full Text Available Introduction: In the present study, the finite element method (FEM was used to investigate the effects of prosthesis material types on stress distribution of the bone surrounding implants and to evaluate stress distribution in three-unit implant-supported fixed dental prosthesis (FDP. Materials and Methods: A three-dimensional (3D finite element FDP model of the maxillary second premolar to the second molar was designed. Three load conditions were statically applied on the functional cusps in horizontal (57.0 N, vertical (200.0 N, and oblique (400.0 N, θ = 120° directions. Four standard framework materials were evaluated: Polymethyl methacrylate (PMMA, base-metal, porcelain fused to metal, andporcelain. Results: The maximum of von Mises stress in the oblique direction was higher than the vertical and horizontal directions in all conditions. In the bone-crestal section, the maximum von Mises stress (53.78 MPa was observed in PMMA within oblique load. In FDPs, the maximum stress was generated at the connector region in all conditions. Conclusion: A noticeable difference was not observed in the bone stress distribution pattern with different prosthetic materials. Although, higher stress value could be seen in polymethyl methacrylate, all types of prosthesis yielded the same stress distribution pattern in FDP. More clinical studies are needed to evaluate the survival rate of these materials.

  15. Effects of Acid Stress on Aerobic Decomposition of Algal and Aquatic Macrophyte Detritus: Direct Comparison in a Radiocarbon Assay

    Science.gov (United States)

    Schoenberg, Steven A.; Benner, Ronald; Armstrong, Anthony; Sobecky, Patricia; Hodson, Robert E.

    1990-01-01

    Radiolabeled phytoplankton and macrophyte lignocelluloses were incubated at pHs 4 and 7 in water from a naturally acidic freshwater wetland (Okefenokee Swamp; ambient pH, 3.8 to 4.2), a freshwater reservoir (L-Lake; pH 6.7 to 7.2), and a marine marsh (Sapelo Island; pH ∼7.8). The data suggest that acidity is an important factor in explaining the lower decomposition rates of algae in Okefenokee Swamp water relative to L-Lake or Sapelo Island water. The decomposition of algal substrate was less sensitive to low pH (∼5 to 35% inhibition) than was the decomposition of lignocellulose (∼30 to 70% inhibition). These substrate-dependent differences were greater and more consistent in salt marsh than in L-lake incubations. In both freshwater sites, the extent to which decomposition was suppressed by acidity was greater for green algal substrate than for mixed diatom or blue-green algal (cyanobacteria) substrates. The use of different bases to adjust pH or incubation in a defined saltwater medium had no significant effect on substrate-dependent differences. Although pH differences with lignocellulose were larger in marine incubations, amendment of lakewater with marine bacteria or with calcium, known to stabilize exoenzymes in soils, did not magnify the sensitivity of decomposition to acid stress. PMID:16348097

  16. Pure shear horizontal SAW biosensor on langasite.

    Science.gov (United States)

    Berkenpas, Eric; Bitla, Shivashanker; Millard, Paul; da Cunha, Mauricio Pereira

    2004-11-01

    The undetected introduction of pathogens into food or water supplies can produce grave consequences in terms of economic loss and human suffering. Sensitive and selective sensors capable of quickly detecting microbial pathogens are urgently needed to limit the effects of bioterrorist incidents, accidents, or pollution. Shear horizontal surface acoustic wave (SH SAW) devices provide an attractive platform for the design of microbial biosensors that function in liquid media, where Rayleigh-type modes are rapidly attenuated. This paper reports on an exploratory SH SAW delay line designed and fabricated on langasite, La3Ga5SiO14 (LGS), along the novel Euler propagation direction (0 degrees, 22 degrees, 90 degrees). A liquid chamber was fabricated and attached to the top surface, and the device was submitted to liquid and biochemical tests. Moderate (6 dB) additional attenuation of the transmission coefficient, /S21/, was consistently observed when the SH SAW delay line was assembled in the test fixture and submitted to the liquid tests, indicating that LGS is an attractive candidate for liquid sensing. Sensor selectivity can be achieved by integrating the LGS SH SAW delay line with a biochemical recognition layer. A test setup was implemented for the characterization of LGS SH SAW-based biosensors. The delay line response to biomolecule binding was shown by detection of sequential binding of proteins to the SH SAW device delay path. The biotinylated sensor was exposed sequentially to biotin-binding deglycosylated avidin, biotin-modified rabbit IgG, and goat anti-rabbit IgG antibody. As each protein was bound to the sensing surface, marked changes in the delay-line phase were recorded. The reported results demonstrate the capability of these devices to act as biochemical detectors in aqueous solutions, and this work represents the first effort using the novel material LGS in SAW-based biosensor technology.

  17. Human balance responses to perturbations in the horizontal plane.

    Science.gov (United States)

    Fritschi, Michael; Jelinek, Herbert F; McGloughlin, Tim; Khalaf, Kinda; Khandoker, Ahsan H; Vallery, Heike

    2014-01-01

    Human balance strategies during standing have been studied extensively. Most of these studies rely on perturbations to the feet, for example by moving platforms or treadmills, and focus on the sagittal plane. Less research has been done on reactions to perturbations to the upper body, and the direction dependence of stabilizing strategies is still an open question. Here, we describe an experiment where we apply horizontal static pulling forces to the upper body of standing human subjects in different directions by means of an overhead robotic device, the FLOAT. Based on a simplified mechanical model, we propose the normalized displacement of the center of pressure, the ΔCoPn, as a measure of the selected balance strategy. We find that existing neuromechanical models do not fully explain responses to these static horizontal forces, because they predict too much CoP movement. Further, we found a tendency to particularly reduce CoP movement in anterior-posterior direction, indicating that reconfiguration of the body may play a larger role in this direction.

  18. Measurement of the stress field of a tunnel through its rock EMR

    Science.gov (United States)

    Qiu, Liming; Wang, Enyuan; Song, Dazhao; Liu, Zhentang; Shen, Rongxi; Lv, Ganggang; Xu, Zhaoyong

    2017-08-01

    In order to quantitatively study the relationship between the disturbance stress of coal mine roadways and the electromagnetic radiation (EMR) of rocks, and further evaluate their internal stress distributions, we first examined the characteristics of EMR signals emitted from rock mass under uniaxial compression, analyzed the relationship between the stress inside the rock mass and its emitted EMR intensity, and put forward a new disturbance stress testing method by monitoring the EMR from the rock mass to retrieve its surrounding stress field. Then, we applied the method to monitor EMR intensity from the no.11803 rock roadway of the Nuodong coal mine, China, and inversely retrieved its stress field. Lastly, we analyzed the causes of local stress anomalies in the Nuodong area by testing the EMR intensity of its nearby areas, and we examined the geology of the whole region. The results showed that: (1) in the rock roadway and the surrounding area of the Nuodong coal mine, the disturbance stress was in the range of 4.8 ∼ 9.1 MPa, the angle between the direction of the stress field and the horizontal plane of the roadway was 35 ± 2.5°, the lateral pressure coefficient was 1.30 ∼ 1.57 (2) the Laoguishan and Yulong anticlines in the vicinity of the Nuodong coal mine caused great horizontal tectonic stress in the region, and the existence of the auxiliary roadway and F12 normal fault resulted in the formation of two high stress zones in the no.11803 rock roadway. Overall, monitoring the EMR from rock mass could ascertain the state, direction, size and distribution of disturbance stress in a roadway and further obtain the distribution of the stress field of an underground structure.

  19. 3D geomechanical modeling and numerical simulation of in-situ stress fields in shale reservoirs: A case study of the lower Cambrian Niutitang formation in the Cen'gong block, South China

    Science.gov (United States)

    Liu, Jingshou; Ding, Wenlong; Yang, Haimeng; Wang, Ruyue; Yin, Shuai; Li, Ang; Fu, Fuquan

    2017-08-01

    An analysis of the in-situ state of stress in a shale reservoir was performed based on comprehensive information about the subsurface properties from wellbores established during the development of an oil and gas field. Industrial-level shale gas production has occurred in the Niutitang formation of the lower Cambrian Cen'gong block, South China. In this study, data obtained from hydraulic fracturing, drilling-induced fractures, borehole breakout, global positioning system (GPS), and well deviation statistics have been used to determine the orientation of the maximum horizontal principal stress. Additionally, hydraulic fracturing and multi-pole array acoustic logging (XMAC) were used to determine the vertical variations in the in-situ stress magnitude. Based on logging interpretation and mechanical experiments, the spatial distributions of mechanical parameters were obtained by seismic inversion, and a 3D heterogeneous geomechanical model was established using a finite element stress analysis approach to simulate the in-situ stress fields. The effects of depth, faults, rock mechanics, and layer variations on the principal stresses, horizontal stress difference (Δσ), horizontal stress difference coefficient (Kh), and stress type coefficient (Sp) were determined. The results show that the direction of the maximum principal stress is ESE 120°. Additionally, the development zones of natural fractures appear to correlate with regions with high principal stress differences. At depths shallower than 375 m, the stress type is mainly a thrust faulting stress regime. At depths ranging from 375 to 950 m, the stress type is mainly a strike-slip faulting stress regime. When the depth is > 950 m, the stress type is mainly a normal faulting stress regime. Depth, fault orientation, and rock mechanics all affect the type of stress. The knowledge regarding the Cen'gong block is reliable and can improve borehole stability, casing set point determination, well deployment

  20. Characterization and modeling of in situ stress heterogeneity

    Science.gov (United States)

    Day-Lewis, Amy D. F.

    Through a series of related projects, the work described in this dissertation strives to better constrain, describe, and explain in situ stress heterogeneity. Although each project has specific goals, approaches, and outcomes, combined they represent important progress in the ongoing effort to understand stress heterogeneity at a variety of scales. In the first study we analyze multi-scale variations in the direction of maximum horizontal compressive stress as a function of depth in four scientific research boreholes located in a variety of tectonic environments. Our results provide insight into the mechanisms controlling in situ crustal stress heterogeneity over scales from centimeters to kilometers. We show that the orientation of the maximum, horizontal compressive stress determined from stress-induced wellbore failures displays scale-invariant, fractal distributions with spectral exponents between 1 and 2. The scaling of the stress variations is remarkably similar to the spatial scaling of earthquakes as a function of fault size in the individual study areas. Consequently, we suggest that wellbore stress heterogeneity is controlled by slip on a fractal distribution of active faults in the surrounding crust. The observed correlation between the amount of stress heterogeneity and local fault behavior may prove useful in models of dynamic earthquake rupture, where many of the key parameters including stress and fault strength appear to vary spatially. In the second study we develop two models---a two-dimensional, analytical model and a three-dimensional, numerical model---to explain the rotation of in situ stresses resulting from a pore pressure change on one side of an impermeable boundary (for example, near an impermeable fault in a depleted reservoir). Our models show clearly that near the boundary depletion will induce the maximum horizontal compressive stress to become more parallel to the boundary, whereas injection will have the opposite effect. We find a

  1. Overcoming horizontal depolarizing resonances with multiple tune jumps

    Directory of Open Access Journals (Sweden)

    H. Huang

    2014-08-01

    Full Text Available In a medium energy proton synchrotron, strong enough partial Siberian snakes can be used to avoid both imperfection and vertical intrinsic depolarizing resonances. However, partial snakes tilt the stable spin direction away from vertical, which generates depolarizing resonances associated with horizontal tune. The relatively weak but numerous horizontal intrinsic resonances are the main source of the residual polarization losses. A pair of horizontal tune jump quads have been used in the Brookhaven Alternating Gradient Synchrotron to overcome these weak resonances. The locations of the two quads have to be chosen such that the disturbance to the beam optics is minimum. The emittance growth has to be mitigated for this method to work. In addition, this technique needs very accurate jump timing. Using two partial Siberian snakes, with vertical tune inside the spin tune gap and 80% polarization at the Alternating Gradient Synchrotron injection, polarized proton beam had reached 1.5×10^{11} proton per bunch with 65% polarization. With the tune jump timing optimized and emittance preserved, more than 70% polarization with 2×10^{11} protons per bunch has been achieved. The polarization transport efficiency is close to 90%.

  2. Tectonic stress in the plates

    Science.gov (United States)

    Richardson, R. M.; Solomon, S. C.; Sleep, N. H.

    1979-01-01

    In the present paper, the basic set of global intraplate stress orientation data is plotted and tabulated. Although the global intraplate stress field is complicated, several large-scale patterns can be seen. Much of stable North America is characterized by an E-W to NE-SW trend for the maximum compressive stress. South American lithosphere beneath the Andes, and perhaps farther east in the stable interior, has horizontal compressive stresses trending E-W to NW-SE. Western Europe north of the Alps is characterized by a NW-SE trending maximum horizontal compression, while Asia has the maximum horizontal compressive stress trending more nearly N-S, especially near the Himalayan front.

  3. Horizontal alveolar bone loss: A periodontal orphan

    Science.gov (United States)

    Jayakumar, A.; Rohini, S.; Naveen, A.; Haritha, A.; Reddy, Krishnanjeneya

    2010-01-01

    Background: Attempts to successfully regenerate lost alveolar bone have always been a clinician’s dream. Angular defects, at least, have a fairer chance, but the same cannot be said about horizontal bone loss. The purpose of the present study was to evaluate the prevalence of horizontal alveolar bone loss and vertical bone defects in periodontal patients; and later, to correlate it with the treatment modalities available in the literature for horizontal and vertical bone defects. Materials and Methods: The study was conducted in two parts. Part I was the radiographic evaluation of 150 orthopantomographs (OPGs) (of patients diagnosed with chronic periodontitis and seeking periodontal care), which were digitized and read using the AutoCAD 2006 software. All the periodontitis-affected teeth were categorized as teeth with vertical defects (if the defect angle was ≤45° and defect depth was ≥3 mm) or as having horizontal bone loss. Part II of the study comprised search of the literature on treatment modalities for horizontal and vertical bone loss in four selected periodontal journals. Results: Out of the 150 OPGs studied, 54 (36%) OPGs showed one or more vertical defects. Totally, 3,371 teeth were studied, out of which horizontal bone loss was found in 3,107 (92.2%) teeth, and vertical defects were found only in 264 (7.8%) of the teeth, which was statistically significant (P<.001). Search of the selected journals revealed 477 papers have addressed the treatment modalities for vertical and horizontal types of bone loss specifically. Out of the 477 papers, 461 (96.3%) have addressed vertical bone loss, and 18 (3.7%) have addressed treatment options for horizontal bone loss. Two papers have addressed both types of bone loss and are included in both categories. Conclusion: Horizontal bone loss is more prevalent than vertical bone loss but has been sidelined by researchers as very few papers have been published on the subject of regenerative treatment modalities for

  4. Horizontal integration in the development strategy of mining companies

    Directory of Open Access Journals (Sweden)

    Jan Kudełko

    2016-01-01

    Full Text Available Integration strategy is one option in the development of mining companies and is implemented through a connection of either processes or economic entities which operate or may operate separately. Usually this strategy is carried out by companies that occupy a very strong competitive position. Considering its direction, it may be horizontal or vertical. Horizontal integration strategy stems from a desire to increase market share by an entrepreneur or create a new company based on common know-how and combined operational processes. It can be realized in an external dimension through a merger or takeover, as well as in the internal dimension based on its own resources. The external dimension is based on capital or contractual integration of a company with external economic entities performing related or conglomerate activity. The targets of such integration have a resource, a market effectiveness, or a competence nature. In the case of mining companies, it covers all important activity areas, including geology, mining, processing, environmental protection, and waste management, and is carried out with due diligence. In the internal dimension, the strategy of horizontal integration consists in consolidating the strategic targets of all business units around the company’s (corporation’s targets. The authors focused on two trends most relevant to pursuing a horizontal integration strategy, including increasing the company’s flexibility and undertaking joint activities. Flexibility consists in the potential ability of the company to adapt quickly to changed environment conditions. Joint activity includes co-operation of its respective units in terms of products, markets, and functions.

  5. Horizontal bone augmentation: the decision tree.

    Science.gov (United States)

    Fu, Jia-Hui; Wang, Hom-Lay

    2011-01-01

    The emergence of implant dentistry has led to the need for bone augmentation procedures. With the removal of a tooth, there is an inevitable three-dimensional (3D) loss of alveolar bone. More often than not, horizontal bone loss occurs at a faster rate and to a greater extent compared to vertical bone loss. This led to the development of several horizontal bone augmentation techniques, such as guided bone regeneration, ridge expansion, distraction osteogenesis, and block grafts. These proposed augmentation techniques aim to place the implant in an ideal 3D position for successful restorative therapy. The literature has shown that horizontal bone augmentation is fairly predictable if certain criteria are fulfilled. However, with numerous techniques and materials currently available, it is difficult to choose the most suitable treatment modality. A search of the literature available was conducted to validate the decision-making process when planning for a horizontal ridge augmentation procedure. The decision tree proposed in this paper stems from the 3D buccolingual bone width available at the site of implant placement (⋝ 3.5 mm, factors such as the tissue thickness, the arch position, and the availability of autogenous bone. The decision tree provides insight on how clinicians can choose the most appropriate and predictable horizontal ridge augmentation procedure to minimize unnecessary complications.

  6. Numerical Investigation on the Heat Extraction Capacity of Dual Horizontal Wells in Enhanced Geothermal Systems Based on the 3-D THM Model

    Directory of Open Access Journals (Sweden)

    Zhixue Sun

    2018-01-01

    Full Text Available The Enhanced Geothermal System (EGS constructs an artificial thermal reservoir by hydraulic fracturing to extract heat economically from hot dry rock. As the core element of the EGS heat recovery process, mass and heat transfer of working fluid mainly occurs in fractures. Since the direction of the natural and induced fractures are generally perpendicular to the minimum principal stress in the formation, as an effective stimulation approach, horizontal well production could increase the contact area with the thermal reservoir significantly. In this paper, the thermal reservoir is developed by a dual horizontal well system and treated as a fractured porous medium composed of matrix rock and discrete fracture network. Using the local thermal non-equilibrium theory, a coupled THM mathematical model and an ideal 3D numerical model are established for the EGS heat extraction process. EGS heat extraction capacity is evaluated in the light of thermal recovery lifespan, average outlet temperature, heat production, electricity generation, energy efficiency and thermal recovery rate. The results show that with certain reservoir and production parameters, the heat production, electricity generation and thermal recovery lifespan can achieve the commercial goal of the dual horizontal well system, but the energy efficiency and overall thermal recovery rate are still at low levels. At last, this paper puts forward a series of optimizations to improve the heat extraction capacity, including production conditions and thermal reservoir construction design.

  7. Stress controlled pulsed direct current co-sputtered Al{sub 1−x}Sc{sub x}N as piezoelectric phase for micromechanical sensor applications

    Energy Technology Data Exchange (ETDEWEB)

    Fichtner, Simon, E-mail: sif@tf.uni-kiel.de [Institute of Material Science, Christian-Albrechts-Universität, Kaiserstr. 2, 24143 Kiel (Germany); Reimer, Tim; Chemnitz, Steffen; Wagner, Bernhard [Institute of Material Science, Christian-Albrechts-Universität, Kaiserstr. 2, 24143 Kiel (Germany); Fraunhofer Institute for Silicon Technology, Fraunhoferstr. 1, 25524 Itzehoe (Germany); Lofink, Fabian [Fraunhofer Institute for Silicon Technology, Fraunhoferstr. 1, 25524 Itzehoe (Germany)

    2015-11-01

    Scandium alloyed aluminum nitride (Al{sub 1−x}Sc{sub x}N) thin films were fabricated by reactive pulsed direct current co-sputtering of separate scandium and aluminum targets with x ≤ 0.37. A significant improvement of the clamped transversal piezoelectric response to strain e{sub 31,f} from −1.28 C/m{sup 2} to −3.01 C/m{sup 2} was recorded, while dielectric constant and loss angle remain low. Further, the built-in stress level of Al{sub 1−x}Sc{sub x}N was found to be tuneable by varying pressure, Ar/N{sub 2} ratio, and Sc content. The thus resulting enhancement of the expectable signal to noise ratio by a factor of 2.1 and the ability to control built-in stress make the integration of Al{sub 1−x}Sc{sub x}N as the piezoelectric phase of micro-electro-mechanical system sensor applications highly attractive.

  8. [Instability pattern of acromioclavicular joint dislocations type Rockwood III: relevance of horizontal instability].

    Science.gov (United States)

    Wellmann, M; da Silva, G; Lichtenberg, S; Magosch, P; Habermeyer, P

    2013-04-01

    There is no evidence-based treatment algorithm established for acromioclavicular joint (AC joint) dislocation classified as type Rockwood III injury. Recent meta-analyses revealed no advantage of surgical treatment compared to the non-operative approach. Both surgical and non-surgical approaches have been reported with inconsistent results. Therefore, the hypothesis of the current study was that patients classified as having Rockwood grade III injury may have different degrees of horizontal AC joint instability. A total of 18 consecutive patients who had sustained a dislocation of the AC joint classified as Rockwood III were evaluated radiologically to quantify the horizontal instability of the AC joint. The specific radiological investigation included lateral stress x-rays (Alexander view) und axial stress x-rays with the affected arm in a horizontal adduction position. The dynamic horizontal instability of the AC joint was found to be independent of the vertical dislocation measured in the Rockwood classification. For further treatment studies Rockwood III injuries should be distinguished in patients presenting with or without a substantial horizontal AC joint instability.

  9. Experimental evolution of recombination and crossover interference in Drosophila caused by directional selection for stress-related traits.

    Science.gov (United States)

    Aggarwal, Dau Dayal; Rashkovetsky, Eugenia; Michalak, Pawel; Cohen, Irit; Ronin, Yefim; Zhou, Dan; Haddad, Gabriel G; Korol, Abraham B

    2015-11-27

    Population genetics predicts that tight linkage between new and/or pre-existing beneficial and deleterious alleles should decrease the efficiency of natural selection in finite populations. By decoupling beneficial and deleterious alleles and facilitating the combination of beneficial alleles, recombination accelerates the formation of high-fitness genotypes. This may impose indirect selection for increased recombination. Despite the progress in theoretical understanding, interplay between recombination and selection remains a controversial issue in evolutionary biology. Even less satisfactory is the situation with crossover interference, which is a deviation of double-crossover frequency in a pair of adjacent intervals from the product of recombination rates in the two intervals expected on the assumption of crossover independence. Here, we report substantial changes in recombination and interference in three long-term directional selection experiments with Drosophila melanogaster: for desiccation (~50 generations), hypoxia, and hyperoxia tolerance (>200 generations each). For all three experiments, we found a high interval-specific increase of recombination frequencies in selection lines (up to 40-50% per interval) compared to the control lines. We also discovered a profound effect of selection on interference as expressed by an increased frequency of double crossovers in selection lines. Our results show that changes in interference are not necessarily coupled with increased recombination. Our results support the theoretical predictions that adaptation to a new environment can promote evolution toward higher recombination. Moreover, this is the first evidence of selection for different recombination-unrelated traits potentially leading, not only to evolution toward increased crossover rates, but also to changes in crossover interference, one of the fundamental features of recombination.

  10. High pressures and asymmetrical stresses in the scoliotic disc in the absence of muscle loading

    Directory of Open Access Journals (Sweden)

    Fairbank Jeremy CT

    2007-02-01

    Full Text Available Abstract Background Loads acting on scoliotic spines are thought to be asymmetric and involved in progression of the scoliotic deformity; abnormal loading patterns lead to changes in bone and disc cell activity and hence to vertebral body and disc wedging. At present however there are no direct measurements of intradiscal stresses or pressures in scoliotic spines. The aim of this study was to obtain quantitative measurements of the intradiscal stress environment in scoliotic intervertebral discs and to determine if loads acting across the scoliotic spine are asymmetric. We performed in vivo measurements of stresses across the intervertebral disc in patients with scoliosis, both parallel (termed horizontal and perpendicular (termed vertical to the end plate, using a side mounted pressure transducer (stress profilometry Methods Stress profilometry was used to measure horizontal and vertical stresses at 5 mm intervals across 25 intervertebral discs of 7 scoliotic patients during anterior reconstructive surgery. A state of hydrostatic pressure was defined by identical horizontal and vertical stresses for at least two consecutive readings. Results were compared with similar stress profiles measured during surgery across 10 discs of 4 spines with no lateral curvature and with data from the literature. Results Profiles across scoliotic discs were very different from those of normal, young, healthy discs of equivalent age previously presented in the literature. Hydrostatic pressure regions were only seen in 14/25 discs, extended only over a short distance. Non-scoliotic discs of equivalent age would be expected to show large centrally placed hydrostatic nuclear regions in all discs. Mean pressures were significantly greater (0.25 MPa than those measured in other anaesthetised patients ( Conclusion Intradiscal pressures and stresses in scoliotic discs are abnormal, asymmetrical and high in magnitude even in the absence of significant applied muscle

  11. HORIZONTAL WELL DRILL-IN FLUIDS

    Directory of Open Access Journals (Sweden)

    Nediljka Gaurina-Međimurec

    1998-12-01

    Full Text Available Main objective of horizontal driling is to place a drain-hole for a long distance within the pay zone to enhance productivity or injectivity. In drilling horizontal wells, more serious problems appear than in drilling vertical wells. These problems are: poor hole cleaning, excessive torque and drag, hole filling, pipe stucking, wellbore instability, loss of circulation, formation damage, poor cement job, and difficulties at logging jobs. From that reason, successful drilling and production of horizontal well depends largely on the fluid used during drilling and completion phases. Several new fluids, that fulfill some or all of required properties (hole cleaning, cutting suspension, good lubrication, and relative low formation damage, are presented in this paper.

  12. Fourth international seminar on horizontal steam generators

    Energy Technology Data Exchange (ETDEWEB)

    Tuomisto, H. [ed.] [IVO Group, Vantaa (Finland); Purhonen, H. [ed.] [VTT, Espoo (Finland); Kouhia, V. [ed.] [Lappeenranta Univ. of Technology (Finland)

    1997-12-31

    The general objective of the International Seminars of Horizontal Steam Generator Modelling has been the improvement in understanding of realistic thermal hydraulic behaviour of the generators when performing safety analyses for VVER reactors. The main topics presented in the fourth seminar were: thermal hydraulic experiments and analyses, primary collector integrity, feedwater distributor replacement, management of primary-to-secondary leakage accidents and new developments in the VVER safety technology. The number of participants, representing designers and manufacturers of the horizontal steam generators, plant operators, engineering companies, research organizations, universities and regulatory authorities, was 70 from 10 countries.

  13. Energy harvesting from coherent resonance of horizontal vibration of beam excited by vertical base motion

    Energy Technology Data Exchange (ETDEWEB)

    Lan, C. B.; Qin, W. Y. [Department of Engineering Mechanics, Northwestern Polytechnical University, Xi' an 710072 (China)

    2014-09-15

    This letter investigates the energy harvesting from the horizontal coherent resonance of a vertical cantilever beam subjected to the vertical base excitation. The potential energy of the system has two symmetric potential wells. So, under vertical excitation, the system can jump between two potential wells, which will lead to the large vibration in horizontal direction. Two piezoelectric patches are pasted to harvest the energy. From experiment, it is found that the vertical excitation can make the beam turn to be bistable. The system can transform vertical vibration into horizontal vibration of low frequency when excited by harmonic motion. The horizontal coherence resonance can be observed when excited by a vertical white noise. The corresponding output voltages of piezoelectric films reach high values.

  14. Effects of horizontal acceleration on the superconducting gravimeter CT #036 at Ishigakijima, Japan

    Science.gov (United States)

    Imanishi, Yuichi; Nawa, Kazunari; Tamura, Yoshiaki; Ikeda, Hiroshi

    2018-01-01

    In the gravity sensor of a superconducting gravimeter, a superconducting sphere as a test mass is levitated in a magnetic field. Such a sensor is susceptible to applied horizontal as well as vertical acceleration, because the translational degrees of freedom of the mass are not perfectly limited to the vertical direction. In the case of the superconducting gravimeter CT #036 installed at Ishigakijima, Japan, horizontal ground acceleration excited by the movements of a nearby VLBI antenna induces systematic step noise within the gravity recordings. We investigate this effect in terms of the static and dynamic properties of the gravity sensor using data from a collocated seismometer. It is shown that this effect can be effectively modeled by the coupling between the horizontal and vertical components in the gravity sensor. It is also found that the mechanical eigenfrequency for horizontal translation of the levitating sphere is approximately 3 Hz.[Figure not available: see fulltext.

  15. Next-generation sequencing reveals recent horizontal transfer of a DNA transposon between divergent mosquitoes.

    Science.gov (United States)

    Diao, Yupu; Qi, Yumin; Ma, Yajun; Xia, Ai; Sharakhov, Igor; Chen, Xiaoguang; Biedler, Jim; Ling, Erjun; Tu, Zhijian Jake

    2011-02-10

    Horizontal transfer of genetic material between complex organisms often involves transposable elements (TEs). For example, a DNA transposon mariner has been shown to undergo horizontal transfer between different orders of insects and between different phyla of animals. Here we report the discovery and characterization of an ITmD37D transposon, MJ1, in Anopheles sinensis. We show that some MJ1 elements in Aedes aegypti and An. sinensis contain intact open reading frames and share nearly 99% nucleotide identity over the entire transposon, which is unexpectedly high given that these two genera had diverged 145-200 million years ago. Chromosomal hybridization and TE-display showed that MJ1 copy number is low in An. sinensis. Among 24 mosquito species surveyed, MJ1 is only found in Ae. aegypti and the hyrcanus group of anopheline mosquitoes to which An. sinensis belongs. Phylogenetic analysis is consistent with horizontal transfer and provides the basis for inference of its timing and direction. Although report of horizontal transfer of DNA transposons between higher eukaryotes is accumulating, our analysis is one of a small number of cases in which horizontal transfer of nearly identical TEs among highly divergent species has been thoroughly investigated and strongly supported. Horizontal transfer involving mosquitoes is of particular interest because there are ongoing investigations of the possibility of spreading pathogen-resistant genes into mosquito populations to control malaria and other infectious diseases. The initial indication of horizontal transfer of MJ1 came from comparisons between a 0.4x coverage An. sinensis 454 sequence database and available TEs in mosquito genomes. Therefore we have shown that it is feasible to use low coverage sequencing to systematically uncover horizontal transfer events. Expanding such efforts across a wide range of species will generate novel insights into the relative frequency of horizontal transfer of different TEs and

  16. Next-generation sequencing reveals recent horizontal transfer of a DNA transposon between divergent mosquitoes.

    Directory of Open Access Journals (Sweden)

    Yupu Diao

    2011-02-01

    Full Text Available Horizontal transfer of genetic material between complex organisms often involves transposable elements (TEs. For example, a DNA transposon mariner has been shown to undergo horizontal transfer between different orders of insects and between different phyla of animals. Here we report the discovery and characterization of an ITmD37D transposon, MJ1, in Anopheles sinensis. We show that some MJ1 elements in Aedes aegypti and An. sinensis contain intact open reading frames and share nearly 99% nucleotide identity over the entire transposon, which is unexpectedly high given that these two genera had diverged 145-200 million years ago. Chromosomal hybridization and TE-display showed that MJ1 copy number is low in An. sinensis. Among 24 mosquito species surveyed, MJ1 is only found in Ae. aegypti and the hyrcanus group of anopheline mosquitoes to which An. sinensis belongs. Phylogenetic analysis is consistent with horizontal transfer and provides the basis for inference of its timing and direction. Although report of horizontal transfer of DNA transposons between higher eukaryotes is accumulating, our analysis is one of a small number of cases in which horizontal transfer of nearly identical TEs among highly divergent species has been thoroughly investigated and strongly supported. Horizontal transfer involving mosquitoes is of particular interest because there are ongoing investigations of the possibility of spreading pathogen-resistant genes into mosquito populations to control malaria and other infectious diseases. The initial indication of horizontal transfer of MJ1 came from comparisons between a 0.4x coverage An. sinensis 454 sequence database and available TEs in mosquito genomes. Therefore we have shown that it is feasible to use low coverage sequencing to systematically uncover horizontal transfer events. Expanding such efforts across a wide range of species will generate novel insights into the relative frequency of horizontal transfer of

  17. Large-scale direct shear testing of municipal solid waste.

    Science.gov (United States)

    Zekkos, Dimitrios; Athanasopoulos, George A; Bray, Jonathan D; Grizi, Athena; Theodoratos, Andreas

    2010-01-01

    Large direct shear testing (300 mm x 300 mm box) of municipal solid waste (MSW) collected from a landfill located in the San Francisco Bay area was performed to gain insight on the shear response of MSW. The study investigated the effects of waste composition, confining stress, unit weight, and loading rate on the stress-displacement response and shear strength of MSW. The amount and orientation of the fibrous waste materials in the MSW were found to play a critical role. The fibrous material had little effect on the MSW's strength when it was oriented parallel to the shear surface, as is typically the case when waste material is compressed vertically and then tested in a direct shear apparatus. Tests in which the fibrous material was oriented perpendicular to the horizontal shear surface produced significantly stronger MSW specimens. The test results indicate that confining stress and loading rate are also important factors. Based on 109 large-scale direct shear tests, the shear strength of MSW at low moisture contents is best characterized by cohesion=15 kPa, friction angle=36 degrees at a normal stress of 1 atmosphere, and a decrease in the friction angle of 5 degrees for every log-cycle increase in normal stress. 2010 Elsevier Ltd. All rights reserved.

  18. Horizontal gene transfer from Agrobacterium to plants

    Directory of Open Access Journals (Sweden)

    Tatiana V. Matveeva

    2014-08-01

    Full Text Available Most genetic engineering of plants uses Agrobacterium mediated transformation to introduce novel gene content. In nature, insertion of T-DNA in the plant genome and its subsequent transfer via sexual reproduction has been shown in several species in the genera Nicotiana and Linaria. In these natural examples of horizontal gene transfer from Agrobacterium to plants, the T-DNA donor is assumed to be a mikimopine strain of A.rhizogenes. A sequence homologous to the T-DNA of the Ri plasmid of Agrobacterium rhizogenes was found in the genome of untransformed Nicotiana glauca about 30 years ago, and was named cellular T-DNA (cT-DNA. It represents an imperfect inverted repeat and contains homologues of several T-DNA oncogenes (NgrolB, NgrolC, NgORF13, NgORF14 and an opine synthesis gene (Ngmis. A similar cT-DNA has also been found in other species of the genus Nicotiana. These presumably ancient homologues of T-DNA genes are still expressed, indicating that they may play a role in the evolution of these plants. Recently T-DNA has been detected and characterized in Linaria vulgaris and L. dalmatica. In Linaria vulgaris the cT-DNA is present in two copies and organized as a tandem imperfect direct repeat, containing LvORF2, LvORF3, LvORF8, LvrolA, LvrolB, LvrolC, LvORF13, LvORF14, and the Lvmis genes. All L. vulgaris and L. dalmatica plants screened contained the same T-DNA oncogenes and the mis gene. Evidence suggests that there were several independent T-DNA integration events into the genomes of these plant genera. We speculate that ancient plants transformed by A. rhizogenes might have acquired a selective advantage in competition with the parental species. Thus, the events of T-DNA insertion in the plant genome might have affected their evolution, resulting in the creation of new plant species. In this review we focus on the structure and functions of cT-DNA in Linaria and Nicotiana and discuss their possible evolutionary role.

  19. Temperature prediction model for a producing horizontal well

    Science.gov (United States)

    Dawkrajai, Pinan

    Distributed temperature sensors (DTS) are increasingly used for monitoring producing sections of horizontal wells. The temperature data from DTS are reliable, accurate and continuous in time (readings every few minutes) and space (readings every meter). One of the potential uses of DTS is to infer the amount and types of fluid entering horizontal sections. To perform such an inference requires a temperature model. A new analytical model was developed here for predicting the inflow temperature of a fluid entering a horizontal wellbore during production. The distinguishing aspect of the model is that it accounts for subtle thermal energy effects including fluid expansion, viscous dissipative heating, and thermal conduction. Reservoir inflow and wellbore flow are coupled by modeling the reservoir as multi-segmented reservoirs in which the direction of flow in the reservoir is perpendicular (not parallel) to the wellbore. The coupled model is then used to simulate several examples to illustrate how temperature changes with flow rate and type of fluid entering a wellbore. We further develop a numerical temperature model of a bottom water drive reservoir to demonstrate the uses of temperature profiles in detecting water entries. Water in this numerical model is initially located in a deeper and warmer zone below a horizontal well. Results show that oil or water can enter the wellbore 2-3 °F higher, while gas can enter with 5-6 °F lower, than the geothermal temperature. Inflow temperature causes the slope of the wellbore temperature profile to change notably, depending on the flow rates and types of fluid entering. The temperature profile can locate a zone that is producing excessive water or gas if the rate is large. The size of the temperature changes on the profiles is obviously detectable by DTS, which has a resolution as fine as 0.0045 °F for the time and spatial average of 1 hour and 50 feet if the cable range is less than 3,000 feet. This study has confirmed the

  20. Flow mapping for ESS horizontal target

    Energy Technology Data Exchange (ETDEWEB)

    Takeda, Y.; Kikura, H.; Taishi, T. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1997-09-01

    Flow behaviour for ESS horizontal target is studied experimentally using two dimensional water model. A velocity field of stationary flow in reaction zone has been obtained. Three dimensional effect was also studied as a spanwise flow structure. (author) 3 figs., 3 refs.

  1. Horizontal transfer of a plant transposon.

    Directory of Open Access Journals (Sweden)

    Xianmin Diao

    2006-01-01

    Full Text Available The majority of well-documented cases of horizontal transfer between higher eukaryotes involve the movement of transposable elements between animals. Surprisingly, although plant genomes often contain vast numbers of these mobile genetic elements, no evidence of horizontal transfer of a nuclear-encoded transposon between plant species has been detected to date. The most mutagenic known plant transposable element system is the Mutator system in maize. Mu-like elements (MULEs are widespread among plants, and previous analysis has suggested that the distribution of various subgroups of MULEs is patchy, consistent with horizontal transfer. We have sequenced portions of MULE transposons from a number of species of the genus Setaria and compared them to each other and to publicly available databases. A subset of these elements is remarkably similar to a small family of MULEs in rice. A comparison of noncoding and synonymous sequences revealed that the observed similarity is not due to selection at the amino acid level. Given the amount of time separating Setaria and rice, the degree of similarity between these elements excludes the possibility of simple vertical transmission of this class of MULEs. This is the first well-documented example of horizontal transfer of any nuclear-encoded genes between higher plants.

  2. Horizontal Transfer of a Plant Transposon.

    Directory of Open Access Journals (Sweden)

    2005-12-01

    Full Text Available The majority of well-documented cases of horizontal transfer between higher eukaryotes involve the movement of transposable elements between animals. Surprisingly, although plant genomes often contain vast numbers of these mobile genetic elements, no evidence of horizontal transfer of a nuclear-encoded transposon between plant species has been detected to date. The most mutagenic known plant transposable element system is the Mutator system in maize. Mu-like elements (MULEs are widespread among plants, and previous analysis has suggested that the distribution of various subgroups of MULEs is patchy, consistent with horizontal transfer. We have sequenced portions of MULE transposons from a number of species of the genus Setaria and compared them to each other and to publicly available databases. A subset of these elements is remarkably similar to a small family of MULEs in rice. A comparison of noncoding and synonymous sequences revealed that the observed similarity is not due to selection at the amino acid level. Given the amount of time separating Setaria and rice, the degree of similarity between these elements excludes the possibility of simple vertical transmission of this class of MULEs. This is the first well-documented example of horizontal transfer of any nuclear-encoded genes between higher plants.

  3. Determinants Of Vertical And Horizontal Export Diversification ...

    African Journals Online (AJOL)

    This implies that not all types of natural resource endowment have a 'Dutch disease' effect. While inflation, exchange rate, and foreign aid variables have a mixed effect on vertical and horizontal export diversification, political instability however has a strong adverse effect on export diversification; especially for SSA. The key ...

  4. Horizontal Axis Levitron--A Physics Demonstration

    Science.gov (United States)

    Michaelis, Max M.

    2014-01-01

    After a brief history of the Levitron, the first horizontal axis Levitron is reported. Because it is easy to operate, it lends itself to educational physics experiments and analogies. Precession and nutation are visualized by reflecting the beam from a laser pointer off the "spignet". Precession is fundamental to nuclear magnetic…

  5. Third international seminar on horizontal steam generators

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-12-31

    The Third International Seminar on Horizontal Steam Generators held on October 18-20, 1994 in Lappeenranta, consisted of six sessions dealing with the topics: thermal hydraulic experiments and analyses, primary collector integrity, management of primary-to-secondary leakage accidents, feedwater collector replacement and discussion of VVER-440 steam generator safety issues.

  6. Parametric study for horizontal steam generator modelling

    Energy Technology Data Exchange (ETDEWEB)

    Ovtcharova, I. [Energoproekt, Sofia (Bulgaria)

    1995-12-31

    In the presentation some of the calculated results of horizontal steam generator PGV - 440 modelling with RELAP5/Mod3 are described. Two nodalization schemes have been used with different components in the steam dome. A study of parameters variation on the steam generator work and calculated results is made in cases with separator and branch.

  7. Evaluation of horizontal magnification on panoramic images

    Directory of Open Access Journals (Sweden)

    Maryam Raoof

    2013-01-01

    Full Text Available Aims: This study evaluated the horizontal magnification of images taken from adults and pediatrics with PM 2002 CC Planmeca analogue machine. Materials and Methods: A series of 120 panoramic radiographs were obtained of 60 adults and 60 pediatrics. For all patients, negative impressions were used to make positive casts of the teeth. A caliper was used to measure the maximum mesiodistal length of the buccal surface of all teeth except canines on both casts and radiographs. The horizontal magnification factor was calculated for incisor, premolar, and molar regions by dividing the values obtained from the casts by the values obtained from the radiographs. Statistical Analysis: Independent t-test and one-way analysis of variance (ANOVA were used. Results: The results indicated that with regard to adults, maxillary and mandibular incisor regions, unlike the other two sessions, didn′t show significant difference of the mean magnification of horizontal dimension (P = 0.5. In pediatrics, the comparison between mean magnification factors of all subgroups showed significant difference (P < 0.0001. Despite the adults′ radiographs, the results of pediatrics′ radiographs showed significantly higher magnification than the index listed by the manufacturer of the radiographic machine used. Conclusion: The present study results point to the fact that PM 2002 CC Proline panoramic machine makes possible precise measurements on radiographs of adults′ jaws in the horizontal dimension.

  8. Horizontal gene transfer in the phytosphere

    NARCIS (Netherlands)

    Elsas, van J.D.; Turner, S.; Bailey, M.J.

    2003-01-01

    Here, the ecological aspects of gene transfer processes between bacteria in the phytosphere are examined in the context of emerging evidence for the dominant role that horizontal gene transfer (HGT) has played in the evolutionary shaping of bacterial communities. Moreover, the impact of the putative

  9. Detecting Highways of Horizontal Gene Transfer

    Science.gov (United States)

    Bansal, Mukul S.; Gogarten, J. Peter; Shamir, Ron

    In a horizontal gene transfer (HGT) event a gene is transferred between two species that do not share an ancestor-descendant relationship. Typically, no more than a few genes are horizontally transferred between any two species. However, several studies identified pairs of species between which many different genes were horizontally transferred. Such a pair is said to be linked by a highway of gene sharing. We present a method for inferring such highways. Our method is based on the fact that the evolutionary histories of horizontally transferred genes disagree with the corresponding species phylogeny. Specifically, given a set of gene trees and a trusted rooted species tree, each gene tree is first decomposed into its constituent quartet trees and the quartets that are inconsistent with the species tree are identified. Our method finds a pair of species such that a highway between them explains the largest (normalized) fraction of inconsistent quartets. For a problem on n species, our method requires O(n 4) time, which is optimal with respect to the quartets input size. An application of our method to a dataset of 1128 genes from 11 cyanobacterial species, as well as to simulated datasets, illustrates the efficacy of our method.

  10. Horizontal gene transfer and bacterial diversity

    Indian Academy of Sciences (India)

    Unknown

    introduction of novel physiological traits from distantly related organisms, horizontal gene transfer often causes drastic changes in the ecological ..... degradation by host restriction endonucleases. (iii) Conjugation: In this mechanism, ... mosome, formation of a conjugative bridge and trans- position into the recipient strain.

  11. comparative evaluation of pressure distribution between horizontal ...

    African Journals Online (AJOL)

    user

    Green and source function were used to evaluate the performance of horizontal well and vertical well, eventually, compared based dimensionless pressures and pressure derivatives computed by varying the reservoir geometry. Results presented as type curves show that the rate of decline of the pressure derivative curve is.

  12. Comparative evaluation of pressure distribution between horizontal ...

    African Journals Online (AJOL)

    Green and source function were used to evaluate the performance of horizontal well and vertical well, eventually, compared based dimensionless pressures and pressure derivatives computed by varying the reservoir geometry. Results presented as type curves show that the rate of decline of the pressure derivative curve is ...

  13. A horizontal vane radiometer: Experiment, theory, and simulation

    Energy Technology Data Exchange (ETDEWEB)

    Wolfe, David; Larraza, Andres, E-mail: larraza@nps.edu [Department of Physics, Naval Postgraduate School, Monterey, California 93940 (United States); Garcia, Alejandro [Department of Physics and Astronomy, San Jose State University, San Jose, California 95152 (United States)

    2016-03-15

    The existence of two motive forces on a Crookes radiometer has complicated the investigation of either force independently. The thermal creep shear force in particular has been subject to differing interpretations of the direction in which it acts and its order of magnitude. In this article, we provide a horizontal vane radiometer design which isolates the thermal creep shear force. The horizontal vane radiometer is explored through experiment, kinetic theory, and the Direct Simulation Monte Carlo (DSMC) method. The qualitative agreement between the three methods of investigation is good except for a dependence of the force on the width of the vane even when the temperature gradient is narrower than the vane which is present in the DSMC method results but not in the theory. The experimental results qualitatively resemble the theory in this regard. The quantitative agreement between the three methods of investigation is better than an order of magnitude in the cases examined. The theory is closer to the experimental values for narrow vanes and the simulations are closer to the experimental values for the wide vanes. We find that the thermal creep force acts from the hot side to the cold side of the vane. We also find the peak in the radiometer’s angular speed as a function of pressure is explained as much by the behavior of the drag force as by the behavior of the thermal creep force.

  14. Memory control in post-traumatic stress disorder: evidence from item method directed forgetting in civil war victims in Northern Uganda.

    Science.gov (United States)

    Zwissler, B; Hauswald, A; Koessler, S; Ertl, V; Pfeiffer, A; Wöhrmann, C; Winkler, N; Kissler, J

    2012-06-01

    Traumatized individuals and particularly post-traumatic stress disorder (PTSD) patients are characterized by memory disturbances that suggest altered memory control. The present study investigated the issue using an item method, directed forgetting (DF) paradigm in 51 civil war victims in Uganda. All participants had been exposed to severe traumatic stress and 26 additionally suffered from PTSD. In an item cued, DF paradigm photographs were presented, each followed by an instruction to either remember or forget it. A recognition test for all initially presented photographs and thematically similar distracters followed. DF patterns were compared between the non-PTSD and the PTSD groups. Post-experimental ratings of picture valence and arousal were collected and correlated with DF. Results revealed DF, that is, reduced recognition for 'to-be-forgotten' items in the non-PTSD but not in the PTSD group. Moreover, in the non-PTSD, but not in the PTSD group, false alarms were reduced for 'to-be-remembered' items. Finally, DF was reduced in those participants who rated the pictures as more arousing, the PTSD group giving, on average, higher arousal ratings. Data indicate that DF is reduced in PTSD and that the reduction is related to stimulus arousal. Furthermore, individuals with PTSD are characterized by a more global encoding style than individuals without PTSD, reflected in a higher false alarm rate. In sum, traumatized individuals with (but not without) PTSD are impaired in their ability to selectively control episodic memory encoding. This impairment may contribute to clinical features of the disorder such as intrusions and flashbacks.

  15. Functional Characterization of Dihydroflavonol-4-Reductase in Anthocyanin Biosynthesis of Purple Sweet Potato Underlies the Direct Evidence of Anthocyanins Function against Abiotic Stresses

    Science.gov (United States)

    Wang, Hongxia; Fan, Weijuan; Li, Hong; Yang, Jun; Huang, Jirong; Zhang, Peng

    2013-01-01

    Dihydroflavonol-4-reductase (DFR) is a key enzyme in the catalysis of the stereospecific reduction of dihydroflavonols to leucoanthocyanidins in anthocyanin biosynthesis. In the purple sweet potato (Ipomoea batatas Lam.) cv. Ayamurasaki, expression of the IbDFR gene was strongly associated with anthocyanin accumulation in leaves, stems and roots. Overexpression of the IbDFR in Arabidopsis tt3 mutants fully complemented the pigmentation phenotype of the seed coat, cotyledon and hypocotyl. Downregulation of IbDFR expression in transgenic sweet potato (DFRi) using an RNAi approach dramatically reduced anthocyanin accumulation in young leaves, stems and storage roots. In contrast, the increase of flavonols quercetin-3-O-hexose-hexoside and quercetin-3-O-glucoside in the leaves and roots of DFRi plants is significant. Therefore, the metabolic pathway channeled greater flavonol influx in the DFRi plants when their anthocyanin and proanthocyanidin accumulation were decreased. These plants also displayed reduced antioxidant capacity compared to the wild type. After 24 h of cold treatment and 2 h recovery, the wild-type plants were almost fully restored to the initial phenotype compared to the slower recovery of DFRi plants, in which the levels of electrolyte leakage and hydrogen peroxide accumulation were dramatically increased. These results provide direct evidence of anthocyanins function in the protection against oxidative stress in the sweet potato. The molecular characterization of the IbDFR gene in the sweet potato not only confirms its important roles in flavonoid metabolism but also supports the protective function of anthocyanins of enhanced scavenging of reactive oxygen radicals in plants under stressful conditions. PMID:24223813

  16. Finite element modeling of the residual stress evolution in forged and direct-aged alloy 718 turbine disks during manufacturing and its experimental validation

    Science.gov (United States)

    Drexler, Andreas; Ecker, Werner; Hessert, Roland; Oberwinkler, Bernd; Gänser, Hans-Peter; Keckes, Jozef; Hofmann, Michael; Fischersworring-Bunk, Andreas

    2017-10-01

    In this work the evolution of the residual stress field in a forged and heat treated turbine disk of Alloy 718 and its subsequent relaxation during machining was simulated and measured. After forging at around 1000 °C the disks were natural air cooled to room temperature and direct aged in a furnace at 720 °C for 8 hours and at 620 °C for 8 hours. The machining of the Alloy 718 turbine disk was performed in two steps: The machining of the Alloy 718 turbine disk was performed in two steps: First, from the forging contour to a contour used for ultra-sonic testing. Second, from the latter to the final contour. The thermal boundary conditions in the finite element model for air cooling and furnace heating were estimated based on analytical equations from literature. A constitutive model developed for the unified description of rate dependent and rate independent mechanical material behavior of Alloy 718 under in-service conditions up to temperatures of 1000 °C was extended and parametrized to meet the manufacturing conditions with temperatures up to 1000 °C. The results of the finite element model were validated with measurements on real-scale turbine disks. The thermal boundary conditions were validated in-field with measured cooling curves. For that purpose holes were drilled at different positions into the turbine disk and thermocouples were mounted in these holes to record the time-temperature curves during natural cooling and heating. The simulated residual stresses were validated by using the hole drilling method and the neutron diffraction technique. The accuracy of the finite element model for the final manufacturing step investigated was ±50 MPa.

  17. Joint development in perturbed stress fields near faults

    Science.gov (United States)

    Rawnsley, K. D.; Rives, T.; Petti, J.-P.; Hencher, S. R.; Lumsden, A. C.

    1992-09-01

    Field evidence is presented for complex spatial and temporal perturbations of an otherwise systematic joint pattern around faults from well exposed faulted rock platforms. Joints propagating in perturbed stress fields will curve to follow the directions of the stress field trajectories. A progressive change in joint direction is observed from unperturbed regions away from faults, to strongly perturbed zones adjacent to faults. This indicates that the joint pattern can reflect perturbations of the regional stress field around faults. In the examples, the stress field perturbations are probably due to points of high friction on the fault plane which concentrate stress and distort the stress field in the surrounding rock. The corresponding joints converge at these points and are sub-parallel to the fault along the remainder of the fault plane. The possibility that a fault plane acts as a free surface contained within an elastic body is considered. In this situation the fault plane induces a rotation of the principal stress axes to become either perpendicular or parallel to the fault. The free surface model seems to explain the metre-scale curvature of joints in the vicinity of existing joints, but at the kilometre scale of a large fault plane the model becomes unrealistic unless the fault is open at the Earth's surface. Two examples are investigated from the Lias of Great Britain; at Nash Point and Robin Hood's Bay. Both comprise sub-horizontal strata of relatively homogeneous lithology and bed thickness, which provide striking examples of joints developed near faults.

  18. Plasma Enhanced Chemical Vapour Deposition of Horizontally Aligned Carbon Nanotubes

    Directory of Open Access Journals (Sweden)

    Matthew T. Cole

    2013-05-01

    Full Text Available A plasma-enhanced chemical vapour deposition reactor has been developed to synthesis horizontally aligned carbon nanotubes. The width of the aligning sheath was modelled based on a collisionless, quasi-neutral, Child’s law ion sheath where these estimates were empirically validated by direct Langmuir probe measurements, thereby confirming the proposed reactors ability to extend the existing sheath fields by up to 7 mm. A 7 mbar growth atmosphere combined with a 25 W plasma permitted the concurrent growth and alignment of carbon nanotubes with electric fields of the order of 0.04 V μm−1 with linear packing densities of up to ~5 × 104 cm−1. These results open up the potential for multi-directional in situ alignment of carbon nanotubes providing one viable route to the fabrication of many novel optoelectronic devices.

  19. Stress determination in active thrust belts: An alternative leak-off pressure interpretation

    Science.gov (United States)

    Couzens-Schultz, Brent A.; Chan, Alvin W.

    2010-08-01

    In thrust belts, fluid flow through critically stressed fractures will occur at pressures less than the overburden stress, which is the minimum stress. We propose that low leak-off pressures obtained in active thrust belts may result from this mechanism, leading workers to infer that apparent minimum stresses are 30-60% less than the overburden stress in some compressional settings. Traditionally, leak-off pressure data have been used to constrain the magnitude of minimum stress, assuming that the rock is dilating against the minimum stress during a leak-off test. In our new interpretation, we constrain the stress state by assuming that the leak-off test causes shear failure along pre-existing weaknesses rather than tensile opening. While this mechanism has been discussed in a small number of borehole stability and hydraulic fracture papers, it has not been directly applied to leak-off tests. We considered this interpretation because we observed that some leak-off tests imply an apparent contradiction between the stress states from the standard interpretation of leak-off tests versus the stress state inferred from geologic and geophysical evidence in tectonically active thrust belts. We present two examples with one in an onshore fold-thrust belt and one in a deepwater fold-thrust belt. Our new interpretation of stresses based on shear failure resolves the contradiction and also provides a constraint on the maximum horizontal stress in the fold-thrust belts.

  20. Horizontal sliding of kilometre-scale hot spring area during the 2016 Kumamoto earthquake

    Science.gov (United States)

    Tsuji, Takeshi; Ishibashi, Jun'Ichiro; Ishitsuka, Kazuya; Kamata, Ryuichi

    2017-02-01

    We report horizontal sliding of the kilometre-scale geologic block under the Aso hot springs (Uchinomaki area) caused by vibrations from the 2016 Kumamoto earthquake (Mw 7.0). Direct borehole observations demonstrate the sliding along the horizontal geological formation at ~50 m depth, which is where the shallowest hydrothermal reservoir developed. Owing to >1 m northwest movement of the geologic block, as shown by differential interferometric synthetic aperture radar (DInSAR), extensional open fissures were generated at the southeastern edge of the horizontal sliding block, and compressional deformation and spontaneous fluid emission from wells were observed at the northwestern edge of the block. The temporal and spatial variation of the hot spring supply during the earthquake can be explained by the horizontal sliding and borehole failures. Because there was no strain accumulation around the hot spring area prior to the earthquake and gravitational instability could be ignored, the horizontal sliding along the low-frictional formation was likely caused by seismic forces from the remote earthquake. The insights derived from our field-scale observations may assist further research into geologic block sliding in horizontal geological formations.

  1. Neotectonic stresses in Fennoscandia: field observations and modelling

    Science.gov (United States)

    Pascal, Christophe

    2013-04-01

    The present-day stress state of Fennoscandia is traditionally viewed as the combination of far field sources and residual glacial loading stresses. Investigations were conducted in different regions of Norway with the purpose of detecting and measuring stress-relief features and to derive from them valuable information on the crustal stress state. Stress-relief features are induced by blasting and sudden rock unloading in road construction and quarrying operations and are common in Norway and very likely in other regions of Fennoscandia. Stress relief at the Earth's surface is diagnostic of anomalously high stress levels at shallow depths in the crust and appears to be a characteristic of the formerly glaciated Baltic and Canadian Precambrian shields. The studied stress-relief features are, in general, indicative of NW-SE compression, suggesting ridge-push as the main source of stress. Our derived stress directions are also in excellent agreement with the ones derived from other kinds of stress indicators, including focal mechanisms from deep earthquakes, demonstrating that stress-relief features are valuable for neotectonic research. As a second step we applied numerical modelling techniques to simulate the neotectonic stress field in Fennoscandia with particular emphasis to southern Norway. A numerical method was used to reconstruct the structure of the Fennoscandian lithosphere. The numerical method involves classical steady-state heat equations to derive lithosphere thickness, geotherm and density distribution and, in addition, requires the studied lithosphere to be isostatically compensated at its base. The a priori crustal structure was derived from previous geophysical studies. Undulations of the geoid were used to calibrate the models. Once the density structure of the Fennoscandian lithosphere is reconstructed it is straightforward to quantify its stress state and compare modelling results with existing stress indicators. The modelling suggests that

  2. The ambient stress field in the continental margin around the Korean Peninsula and Japanese islands

    Science.gov (United States)

    Lee, J.; Hong, T. K.; Chang, C.

    2016-12-01

    The ambient stress field is mainly influenced by regional tectonics. The stress field composition is crucial information for seismic hazard assessment. The Korean Peninsula, Japanese Islands and East Sea comprise the eastern margin of the Eurasian plate. The regions are surrounded by the Okhotsk, Pacific, and Philippine Sea plates. We investigate the regional stress field around the Korean Peninsula and Japanese islands using the focal mechanism solutions of regional earthquakes. Complex lateral and vertical variations of regional crustal stress fields are observed around a continental margin. The dominant compression directions are ENE-WSW around the Korean Peninsula and eastern China, E-W in the central East Sea and northern and southern Japan, NW-SE in the central Japan, and N-S around the northern Nankai trough. The horizontal compression directions are observed to be different by fault type, suggesting structure-dependent stress field distortion. The regional stress field change by depth and location, suggesting that the compression and tension stress may alternate in local region. The stress field and structures affect mutually, causing stress field distortion and reactivation of paleo-structures. These observation may be useful for understanding of local stress-field perturbation for seismic hazard mitigation of the region.

  3. Can the Ocean's Heat Engine Control Horizontal Circulation? Insights From the Caspian Sea

    Science.gov (United States)

    Bruneau, Nicolas; Zika, Jan; Toumi, Ralf

    2017-10-01

    We investigate the role of the ocean's heat engine in setting horizontal circulation using a numerical model of the Caspian Sea. The Caspian Sea can be seen as a virtual laboratory—a compromise between realistic global models that are hampered by long equilibration times and idealized basin geometry models, which are not constrained by observations. We find that increases in vertical mixing drive stronger thermally direct overturning and consequent conversion of available potential to kinetic energy. Numerical solutions with water mass structures closest to observations overturn 0.02-0.04 × 106 m3/s (sverdrup) representing the first estimate of Caspian Sea overturning. Our results also suggest that the overturning is thermally forced increasing in intensity with increasing vertical diffusivity. Finally, stronger thermally direct overturning is associated with a stronger horizontal circulation in the Caspian Sea. This suggests that the ocean's heat engine can strongly impact broader horizontal circulations in the ocean.

  4. Pengaruh Komunikasi Horizontal Terhadap Kinerja Pegawai Pada Badan Pemberdayaan Masyarakat Kampung di Kabupaten Jayawijaya

    Directory of Open Access Journals (Sweden)

    Siti Khikmatul Rizqi

    2017-04-01

    Full Text Available This article discusses the effect of Horizontal Communication on Employee Performance at the Office of Community Empowerment Agency (BPMK Jayawijaya Regency. This study consists of two variables, namely as a horizontal free communication variable with research indicators: coordination, problem solving and information exchange. While the dependent variable of employee performance with research indicator: result, benefit and impact. In the sampling of the authors using saturated samples in which the entire population is used as a sample of 27 employees. And data analysis technique that writer use is statistical data analysis with type of associative research and data processed by using simple regression model. The results showed horizontal communication is very strong and direct 0.795 (significant with employee performance at 95% confidence level. Horizontal communication contributes to employee performance of 32.0%.   Artikel ini membahas tentang pengaruh Komunikasi Horizontal Terhadap Kinerja Pegawai pada Kantor Badan Pemberdayaan Masyarakat Kampung (BPMK Kabupaten Jayawijaya. Penelitian ini terdiri dari dua variable yaitu sebagai variabel bebas komunikasi horizontal dengan indikator penelitian: koordinasi, pemecahan masalah dan pertukaran informasi. Sementara variabel terikat kinerja  pegawai dengan indikator penelitian : hasil, manfaat dan dampak. Dalam penarikan sampel penulis menggunakan sampel jenuh dimana seluruh populasi dijadikan sampel yaitu berjumlah 27 pegawai. Dan teknik analisa data yang penulis gunakan adalah analisa data statistik dengan jenis penelitian asosiatif dan data diolah menggunakan model regresi sederhana. Hasil penelitian menunjukkan komunikasi horizontal  berhubungan sangat kuat dan searah sebesar 0,795 (signifikan dengan kinerja pegawai pada taraf kepercayaan 95%. Komunikasi horizontal memberikan kontribusi terhadap kinerja pegawai sebesar 32,0%.

  5. Horizontal gene transfer between bacteria and animals

    Science.gov (United States)

    Dunning Hotopp, Julie C.

    2011-01-01

    Horizontal gene transfer is increasingly described between bacteria and animals. Such transfers that are vertically inherited have the potential to influence the evolution of animals. One classic example is the transfer of DNA from mitochondria and chloroplasts to the nucleus after the acquisition of these organelles by eukaryotes. Even today, many of the described instances of bacteria to animal transfer occur as part of intimate relationships like those of endosymbionts and their invertebrate hosts, particularly insects and nematodes, while numerous transfers are also found in asexual animals. Both of these observations are consistent with modern evolutionary theory, in particular the serial endosymbiotic theory and Muller’s ratchet. While it is tempting to suggest that these particular lifestyles might promote horizontal gene transfer, it is difficult to ascertain given the non-random sampling of animal genome sequencing projects and the lack of a systematic analysis of animal genomes for such transfers. PMID:21334091

  6. Horizontal modular dry irradiated fuel storage system

    Science.gov (United States)

    Fischer, Larry E.; McInnes, Ian D.; Massey, John V.

    1988-01-01

    A horizontal, modular, dry, irradiated fuel storage system (10) includes a thin-walled canister (12) for containing irradiated fuel assemblies (20), which canister (12) can be positioned in a transfer cask (14) and transported in a horizontal manner from a fuel storage pool (18), to an intermediate-term storage facility. The storage system (10) includes a plurality of dry storage modules (26) which accept the canister (12) from the transfer cask (14) and provide for appropriate shielding about the canister (12). Each module (26) also provides for air cooling of the canister (12) to remove the decay heat of the irradiated fuel assemblies (20). The modules (26) can be interlocked so that each module (26) gains additional shielding from the next adjacent module (26). Hydraulic rams (30) are provided for inserting and removing the canisters (12) from the modules (26).

  7. Effects of Ginsenoside Rg1 on Learning and Memory in a Reward-directed Instrumental Conditioning Task in Chronic Restraint Stressed Rats.

    Science.gov (United States)

    Kezhu, Wang; Pan, Xu; Cong, Lu; Liming, Dong; Beiyue, Zhang; Jingwei, Lu; Yanyan, Yang; Xinmin, Liu

    2017-01-01

    Ginsenoside Rg1 is one of the major active ingredients of Panax ginseng and has showed notable improving learning and memory effects in several behavioral tasks, such as water maze, shuttle-box, and step-through, based on avoidance. However, there was no report about the role of Rg1 on the performance of reward-directed instrumental conditioning, which could reflect the adaptive capacity to ever-changing environments. Thus, in this study, the reward devaluation test and conditional visual discrimination task were conducted to study the ameliorating effects of Rg1 on cognitive deficits, especially the loss of adaptation capacity in chronic restraint stress (CRS) rat model. Our results showed that rat subjected to CRS became insensitive to the changes in outcome value, and it significantly harmed the rat's performance in conditional visual discrimination task. Moreover, the levels of BDNF, TrkB, and Erk phosphorylation were decreased in the prefrontal cortex of CRS rats. However, these changes were effectively reversed by Rg1 (5 and 10 mg/kg, i.p.). Therefore, it demonstrated that Rg1 has a good ability to improve learning and memory and also ameliorate impaired adaptive capacity induced by CRS. This amelioration effect of Rg1 might be mediated partially by BDNF/TrkB/Erk pathway in prefrontal cortex. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  8. Mechanical and mathematical models of multi-stage horizontal fracturing strings and their application

    Directory of Open Access Journals (Sweden)

    Zhanghua Lian

    2015-03-01

    Full Text Available Multi-stage SRV fracturing in horizontal wells is a new technology developed at home and abroad in recent years to effectively develop shale gas or low-permeability reservoirs, but on the other hand makes the mechanical environment of fracturing strings more complicated at the same time. In view of this, based on the loading features of tubing strings during the multi-stage fracturing of a horizontal well, mechanical models were established for three working cases of multiple packer setting, open differential-pressure sliding sleeve, and open ball-injection sliding sleeve under a hold-down packer. Moreover, mathematical models were respectively built for the above three cases. According to the Lame formula and Von Mises stress calculation formula for the thick-walled cylinder in the theory of elastic mechanics, a mathematical model was also established to calculate the equivalent stress for tubing string safety evaluation when the fracturing string was under the combined action of inner pressure, external squeezing force and axial stress, and another mathematical model was built for the mechanical strength and safety evaluation of multi-stage fracturing strings. In addition, a practical software was developed for the mechanical safety evaluation of horizontal well multi-stage fracturing strings according to the mathematical model developed for the mechanical calculation of the multi-packer string in horizontal wells. The research results were applied and verified in a gas well of Tahe Oilfield in the Tarim Basin with excellent effects, providing a theoretical basis and a simple and reliable technical means for optimal design and safety evaluation of safe operational parameters of multi-stage fracturing strings in horizontal wells.

  9. Gas reservoir evaluation for underbalanced horizontal drilling

    Directory of Open Access Journals (Sweden)

    Li Gao

    2014-01-01

    Full Text Available A set of surface equipment for monitoring the parameters of fluid and pressure while drilling was developed, and mathematical models for gas reservoir seepage and wellbore two-phase flow were established. Based on drilling operation parameters, well structure and monitored parameters, the wellbore pressure and the gas reservoir permeability could be predicted theoretically for underbalanced horizontal drilling. Based on the monitored gas production along the well depth, the gas reservoir type could be identified.

  10. Surgical treatment for paralytic horizontal strabismus

    Directory of Open Access Journals (Sweden)

    Feng Zhou*

    2015-08-01

    Full Text Available AIM: To observe the effect of surgery for paralytic horizontal strabismus and the paralytic horizontal strabismus performed by Jensen procedure with antagonist muscle of paralytic muscle recession and medial or lateral rectus extra large resection/recession.METHODS: Fifteen cases(17 eyeswith complete or nearly complete paralytic horizontal strabismus from January 2005 to August. 2014 in our hospital were assessed retrospectively,7 eyes of 7 cases with treatment group A were performed Jensen procedure combined antagonist muscle of paralytic muscle recession, 10 eyes of 8 cases with treatment group B were performed medial or lateral rectus extra large resection/recession. seventeen eyes of 15 cases with an average of 21±8.71mo follow-up were observed.RESULTS: All 17 eyes of 15 cases after the operation obtained satisfied effects, 16 eyes of 14 cases obtained ideal long-term effect. One eye of a patient with a 6mo follow-up was undercorrected of 30△. We found a varying degree of postoperative improvement in visual function. There was a significant reduction in the strabismus angle for distance and near(t=28.71, Pt=36.21, Pt=17.96, Pt=9.20,PCONCLUSION: Jensen procedure combined antagonist muscle of paralytic muscle recession and medial or lateral rectus extra large resection/recession is a safe and successful method of treatment in complete or nearly complete paralysis horizontal strabismus. Patients achieve orthophoria, improvement of the motor ability, and larger field of binocular single vision for long time.

  11. Vertical and horizontal seismometric observations of tides

    Science.gov (United States)

    Lambotte, S.; Rivera, L.; Hinderer, J.

    2006-01-01

    Tidal signals have been largely studied with gravimeters, strainmeters and tiltmeters, but can also be retrieved from digital records of the output of long-period seismometers, such as STS-1, particularly if they are properly isolated. Horizontal components are often noisier than the vertical ones, due to sensitivity to tilt at long periods. Hence, horizontal components are often disturbed by local effects such as topography, geology and cavity effects, which imply a strain-tilt coupling. We use series of data (duration larger than 1 month) from several permanent broadband seismological stations to examine these disturbances. We search a minimal set of observable signals (tilts, horizontal and vertical displacements, strains, gravity) necessary to reconstruct the seismological record. Such analysis gives a set of coefficients (per component for each studied station), which are stable over years and then can be used systematically to correct data from these disturbances without needing heavy numerical computation. A special attention is devoted to ocean loading for stations close to oceans (e.g. Matsushiro station in Japon (MAJO)), and to pressure correction when barometric data are available. Interesting observations are made for vertical seismometric components; in particular, we found a pressure admittance between pressure and data 10 times larger than for gravimeters for periods larger than 1 day, while this admittance reaches the usual value of -3.5 nm/s 2/mbar for periods below 3 h. This observation may be due to instrumental noise, but the exact mechanism is not yet understood.

  12. The horizontal plane appearances of scoliosis

    DEFF Research Database (Denmark)

    Illés, Tamás S.; Burkus, Máté; Somoskeőy, Szabolcs

    2017-01-01

    Purpose: A posterior-anterior vertebral vector is proposed to facilitate visualization and understanding of scoliosis. The aim of this study was to highlight the interest of using vertebral vectors, especially in the horizontal plane, in clinical practice. Methods: We used an EOS two-/three-dimen......Purpose: A posterior-anterior vertebral vector is proposed to facilitate visualization and understanding of scoliosis. The aim of this study was to highlight the interest of using vertebral vectors, especially in the horizontal plane, in clinical practice. Methods: We used an EOS two...... cases of a normal spine and a thoracic scoliosis are presented. Results: For a normal spine, vector projections in the transverse plane are aligned with the posterior-anterior anatomical axis. For a scoliotic spine, vector projections in the horizontal plane provide information on the lateral...... of scoliosis. The approach used is simple. These results are sufficient for a first visual analysis furnishing significant clinical information in all three anatomical planes. This visualization represents a reasonable compromise between mathematical purity and practical use....

  13. Construction of preheaters with horizontal tubes

    Energy Technology Data Exchange (ETDEWEB)

    Goetze

    1944-09-27

    This report involved construction of preheaters for distillation and cracking plants in the oil industry, particularly in America. The use of heat transmission by radiation was also a consideration here. The recycling of waste gases occurred, but was not the rule. A convection section was often built next to the radiation section, in which the discharge gases were used for heating the incoming product. The general arrangement of the preheaters was discussed. The first form was a rectangular box with fireproof lining with tubes arranged in a single row along the outer walls and sometimes in a double row on the ceiling. It consisted of smooth and finned tubes. From the simple form a double preheater was developed that allowed one or two common discharge flues to provide as large a heating surface as possible within a reasonable space. Other items discussed were recycling of waste gases, reasons for the choice of horizontal preheaters with radiation heating, the use of vertical tubes in the U.S.A. and elsewhere in the oil industry, details of horizontal preheater tubes, end closures, material, suspension, protection against overloading by radiation, circulation heating, burners, use of horizontal radiation preheaters in hydrogenation in the U.S.A., rebuilding I. G. preheaters, construction, tube supports, and masonry. A list of references on cracking, preheaters, heat transmission, and alloyed steels was given.

  14. A direct comparison of a depth-dependent Radiation stress formulation and a Vortex force formulation within a three-dimensional coastal ocean model

    Science.gov (United States)

    Moghimi, Saeed; Klingbeil, Knut; Gräwe, Ulf; Burchard, Hans

    2013-10-01

    In this study a model system consisting of the three-dimensional General Estuarine Transport Model (GETM) and the third generation wind wave model SWAN was developed. Both models were coupled in two-way mode. The effects of waves were included into the ocean model by implementing the depth-dependent Radiation stress formulation (RS) of Mellor (2011a) and the Vortex force formulation (VF) presented by Bennis et al. (2011). Thus, the developed model system offers a direct comparison of these two formulations. The enhancement of the vertical eddy viscosity due to the energy transfer by white capping and breaking waves was taken into account by means of injecting turbulent kinetic energy at the surface. Wave-current interaction inside the bottom boundary layer was considered as well. The implementation of both wave-averaged formulations was validated against three flume experiments. One of these experiments with long period surface waves (swell), had not been evaluated before. The validation showed the capability of the model system to reproduce the three-dimensional interaction of waves and currents. For the flume test cases the wave-induced water level changes (wave set-up and set-down) and the corresponding depth-integrated wave-averaged velocities were similar for RS and VF. Both formulations produced comparable velocity profiles for short period waves. However, for large period waves, VF overestimated the wave set-down near the main breaking points and RS showed artificial offshore-directed transport at the surface where wave shoaling was taking place. Finally the validated model system was applied to a realistic barred beach scenario. For RS and VF the resulting velocity profiles were similar after being significantly improved by a roller evolution method. Both wave-averaged formulations generally provided similar results, but some shortcomings were revealed. Although VF partly showed significant deviations from the measurements, its results were still physically

  15. Mapping Proprioception across a 2D Horizontal Workspace

    Science.gov (United States)

    Wilson, Elizabeth T.; Wong, Jeremy; Gribble, Paul L.

    2010-01-01

    Relatively few studies have been reported that document how proprioception varies across the workspace of the human arm. Here we examined proprioceptive function across a horizontal planar workspace, using a new method that avoids active movement and interactions with other sensory modalities. We systematically mapped both proprioceptive acuity (sensitivity to hand position change) and bias (perceived location of the hand), across a horizontal-plane 2D workspace. Proprioception of both the left and right arms was tested at nine workspace locations and in 2 orthogonal directions (left-right and forwards-backwards). Subjects made repeated judgments about the position of their hand with respect to a remembered proprioceptive reference position, while grasping the handle of a robotic linkage that passively moved their hand to each judgement location. To rule out the possibility that the memory component of the proprioceptive testing procedure may have influenced our results, we repeated the procedure in a second experiment using a persistent visual reference position. Both methods resulted in qualitatively similar findings. Proprioception is not uniform across the workspace. Acuity was greater for limb configurations in which the hand was closer to the body, and was greater in a forward-backward direction than in a left-right direction. A robust difference in proprioceptive bias was observed across both experiments. At all workspace locations, the left hand was perceived to be to the left of its actual position, and the right hand was perceived to be to the right of its actual position. Finally, bias was smaller for hand positions closer to the body. The results of this study provide a systematic map of proprioceptive acuity and bias across the workspace of the limb that may be used to augment computational models of sensory-motor control, and to inform clinical assessment of sensory function in patients with sensory-motor deficits. PMID:20686612

  16. Direct microscopic observation of striations in a fractured section of a sirolimus-eluting stent (Cypher Bx Velocity®) indicates induction of stent fracture by continuous shear stress.

    Science.gov (United States)

    Endo, Akira; Ishikawa, Tetsuya; Suzuki, Teruhiko; Kashiwagi, Yusuke; Mutoh, Makoto

    2011-01-01

    A 73-year-old woman with severe congestive heart failure was treated by implantation with a sirolimus-eluting stent (SES; Cypher Bx Velocity(®)) in the left main coronary artery (LMCA) using the staged T-stent, kissing balloon, and hugging balloon techniques. Follow-up coronary multislice computed tomography after 10 months revealed that SES was completely fractured in 2 directions; the fractured stent appeared in the shape of the letter "L" and had migrated into the aorta. An SES fragment was surgically removed and subsequent electron microscopy revealed striations (striped patterns in fractured sections) on the fracture plane, indicating continuous shear stress after SES implantation in the LMCA. This case provides direct evidence of continuous shear stress on the SES and indicates the necessity of improving the structure of the stent such that it can withstand shear stress.

  17. Well test analysis of horizontal wells in a two-layered reservoir ...

    African Journals Online (AJOL)

    In this paper, a well test analysis procedure is discussed for a two-layered oil reservoir drained from each layer by a horizontal well. Reservoir mathematical model are derived for each layer so that analysis can be done strictly for each layered reservoir. Procedures for obtaining all the directional permeabilities, wellbore ...

  18. Motions of deformable inclusions in a horizontally oscillating vessel with a compressible fluid

    DEFF Research Database (Denmark)

    Demidov, I.V.; Sorokin, Vladislav

    2016-01-01

    The paper is concerned with the analysis of rigid particle and compressible gas bubble motion in a horizontally oscillating vessel with a compressible fluid. A nonlinear differential equation describing motion of inclusions with respect to the vessel is derived and solved by the method of direct ...

  19. Horizontal Strain Field for the Bohemian Massif, Central Europe

    Science.gov (United States)

    Schenk, V.; Pichl, R.; Schenkova, Z.; Marek, T.

    2010-12-01

    The horizontal strain field of the Bohemian Massif, central Europe, was assessed from GNSS data monitored on permanent stations of the Geodynamic Network of the Academy of Science of the Czech Republic (GEONAS) and of the Czech Office for Surveying, Mapping and Cadastre (CZEPOS). For every area a representative motion velocity was determined. Their comparison with general motions of the Eurasian plate ascertained by the NNR-NUVEL-1A model gave deviations characterizing recent influence of the Alps to the northern geological units, in our case the Bohemian Massif. From these motions a regional pattern of the horizontal strain field for the Bohemian Massif had been calculated. It was found that (i) the northern part of the Massif is under dominant E-W extensions and (ii) slight contractions were detected for the NNE-SSW direction in eastern regions of the Massif. Obtained results will be presented and discussed from a viewpoint of the Alpine structural unit actions to surrounding geological units.

  20. Fuzzy Number Addition with the Application of Horizontal Membership Functions

    Directory of Open Access Journals (Sweden)

    Andrzej Piegat

    2015-01-01

    Full Text Available The paper presents addition of fuzzy numbers realised with the application of the multidimensional RDM arithmetic and horizontal membership functions (MFs. Fuzzy arithmetic (FA is a very difficult task because operations should be performed here on multidimensional information granules. Instead, a lot of FA methods use α-cuts in connection with 1-dimensional classical interval arithmetic that operates not on multidimensional granules but on 1-dimensional intervals. Such approach causes difficulties in calculations and is a reason for arithmetical paradoxes. The multidimensional approach allows for removing drawbacks and weaknesses of FA. It is possible thanks to the application of horizontal membership functions which considerably facilitate calculations because now uncertain values can be inserted directly into equations without using the extension principle. The paper shows how the addition operation can be realised on independent fuzzy numbers and on partly or fully dependent fuzzy numbers with taking into account the order relation and how to solve equations, which can be a difficult task for 1-dimensional FAs.

  1. The formation of sporadic E layers by a vortical perturbation excited in a horizontal wind shear flow

    Directory of Open Access Journals (Sweden)

    G. G. Didebulidze

    2008-06-01

    Full Text Available The formation of the mid-latitude sporadic E layers (Es layers by an atmospheric vortical perturbation excited in a horizontal shear flow (horizontal wind with a horizontal linear shear is investigated. A three-dimensional atmospheric vortical perturbation (atmospheric shear waves, whose velocity vector is in the horizontal plane and has a vertical wavenumber kz≠0, can provide a vertical shear of the horizontal wind. The shear waves influence the vertical transport of heavy metallic ions and their convergence into thin and dense horizontal layers. The proposed mechanism takes into account the dynamical influence of the shear wave velocity in the horizontal wind on the vertical drift velocity of the ions. It also can explain the multi-layer structure of Es layers. The pattern of the multi-layer structure depends on the value of the shear-wave vertical wavelength, the ion-neutral collision frequency and the direction of the background horizontal wind. The modelling of formation of sporadic E layers with a single and a double peak is presented. Also, the importance of shear wave coupling with short-period atmospheric gravity waves (AGWs on the variations of sporadic E layer ion density is examined and discussed.

  2. An experimental study on the resistance and movement of short pile installed in sands under horizontal pullout load

    Directory of Open Access Journals (Sweden)

    Oh Kyun Kwon

    2014-03-01

    Full Text Available In this study, the model tests were conducted on the short piles installed in sands under a horizontal pullout load to investigate their behavior characteristics. From the horizontal loading tests where dimensions of the pile diameter and length, and loading point were varied, the horizontal pullout resistance and the rotational and translational movement pattern of the pile were investigated. As a result, the horizontal pullout resistance of the pile embedded in sands was dependent on the pile length, diameter, loading point, etc. The ultimate horizontal pullout load tended to increase as the loading point (h/L moved to the bottom from the top of the pile, regardless of the ratio between the pile length and diameter (L/D, reached the maximum value at the point of h/L = 0.75, and decreased afterwards. When the horizontal pullout load acted on the upper part above the middle of the pile, the pile rotated clockwise and moved to the pullout direction, and the pivot point of the pile was located at 150–360mm depth below the ground surface. On the other hand, when the horizontal pullout load acted on the lower part of the pile, the pile rotated counterclockwise and travelled horizontally, and the rotational angle was very small.

  3. The Potential for Horizontal Gene Transfer in Sea Ice

    Science.gov (United States)

    Collins, R. E.; Deming, J. W.

    2010-04-01

    Sea ice is a potential hotspot for horizontal gene transfer due to physical concentration of bacteria, viruses, and extracellular DNA. An ice-affiliated bacterium, "Colwellia psychrerythraea," has acquired genes for compatible solute degradation via horizontal gene transfer.

  4. Genetics Home Reference: horizontal gaze palsy with progressive scoliosis

    Science.gov (United States)

    ... Health Conditions HGPPS Horizontal gaze palsy with progressive scoliosis Printable PDF Open All Close All Enable Javascript ... collapse boxes. Description Horizontal gaze palsy with progressive scoliosis ( HGPPS ) is a disorder that affects vision and ...

  5. Present-day stress state analysis on the Big Island of Hawaíi, USA

    Science.gov (United States)

    Pierdominici, Simona; Kueck, Jochem; Millett, John; Planke, Sverre; Jerram, Dougal A.; Haskins, Eric; Thomas, Donald

    2017-04-01

    : borehole breakouts (bidirectional enlargements) (BB) and drilling induced tensile fractures (DIF). BB and DIF occur when the stresses around the borehole exceed the compressive and tensile yield stress of the borehole wall rock respectively causing failure. A breakout is caused by the development of intersecting conjugate shear planes that cause pieces of the borehole wall to spall off. For a breakout to develop, the stress concentration around a vertical borehole is largest in the direction of the minimum horizontal stress. Hence, BB develops approximately parallel to the orientation of the minimum horizontal stress. For the DIF, the stress concentration around a vertical borehole is at a minimum in the maximum horizontal stress direction. Hence, DIF develop approximately parallel to the orientation of the maximum horizontal stress. Based on the World Stress Map, the present-day stress in this area is defined only by focal mechanism solutions. These data give a unique opportunity to characterize the orientation of the present-day stress field between two large volume shield volcanoes on an active volcanic island using a different approach and stress indicators.

  6. Stress transmission in soil

    DEFF Research Database (Denmark)

    Lamandé, Mathieu; Schjønning, Per

    We urgently need increased quantitative knowledge on stress transmission in real soils loaded with agricultural machinery. 3D measurements of vertical stresses under tracked wheels were performed in situ in a Stagnic Luvisol (clay content 20 %) continuously cropped with small grain cereals......). Seven load cells were inserted horizontally from a pit with minimal disturbance of soil in each of three depths (0.3, 0.6 and 0.9 m), covering the width of the wheeled area. The position of the wheel relative to the transducers was recorded using a laser sensor. Finally, the vertical stresses near...... the soil-tyre interface were measured in separate tests by 17 stress transducers across the width of the tyres. The results showed that the inflation pressure controlled the level of maximum stresses at 0.3 m depth, while the wheel load was correlated to the measured stresses at 0.9 m depth. This supports...

  7. Spatial organization of linear vestibuloocular reflexes of the rat: responses during horizontal and vertical linear acceleration.

    Science.gov (United States)

    Hess, B J; Dieringer, N

    1991-12-01

    1. The spatial properties of linear vestibuloocular reflexes (LVOR) were studied in pigmented rats in response to sinusoidal linear acceleration on a sled. The orientation of the animal on the sled was altered in 15 degrees steps over the range of 360 degrees. Horizontal, vertical, and torsional components of eye movements were recorded with the magnetic field search coil technique in complete darkness. Conjugacy of the two eyes was studied in the horizontal movement plane. 2. Acceleration along the optic axis of one eye (approximately 50 degrees lateral) induced maximal vertical responses in the ipsilateral eye and, at the same time, maximal torsional responses in the contralateral eye. These vertical and torsional responses of the LVOR coincide with those obtained when the respective coplanar vertical semicircular canals are stimulated. Such a congruence suggests a common reference frame for LVOR and angular vestibuloocular reflexes (AVOR), with the result that direct combination of signals indicating apparent and real head tilt is facilitated. 3. Transformations of vertical and torsional responses into head coordinates (pitch and roll) show that these movements are compensatory in direction for any combination of apparent head tilt in pitch and roll planes. 4. Gain (rotation of the eye/apparent rotation of the gravity direction) was approximately 0.3 at 0.1 Hz and decreased to approximately 0.1 at 1.0 Hz. Vertical responses tended to have a larger gain than torsional responses. Phase lag relative to peak acceleration increased from about -9 degrees to about -47 degrees over the same frequency range. 5. Vertical linear acceleration evoked only vertical eye movements at a frequency of 1.0 Hz. 6. Horizontal responses of both eyes were symmetric or asymmetric in amplitude and in-phase (conjugate) or out-of-phase (disconjugate) with respect to each other, depending on the direction of linear acceleration. Translation in the transverse direction evoked conjugate

  8. Cuttings Transport Models and Experimental Visualization of Underbalanced Horizontal Drilling

    OpenAIRE

    Na Wei; YingFeng Meng; Gao Li; LiPing Wan; ZhaoYang Xu; XiaoFeng Xu; YuRui Zhang

    2013-01-01

    Aerated underbalanced horizontal drilling technology has become the focus of the drilling industry at home and abroad, and one of the engineering core issues is the horizontal borehole cleaning. Therefore, calculating the minimum injection volume of gas and liquid accurately is essential for the construction in aerated underbalanced horizontal drilling. This paper establishes a physical model of carrying cuttings and borehole cleaning in wellbore of horizontal well and a critical transport ma...

  9. Sand cracks, horizontal fissures, and other conditions affecting the wall of the bovine claw.

    Science.gov (United States)

    Greenough, P R

    2001-03-01

    The wall of the bovine claw is created only by the dermis beneath the coronary band. Keratogenic tissues in this region are susceptible to nutritional changes or stress, which changes the characteristics of the horn produced. Horizontal grooves or fissures result that weaken the claw wall and are instrumental in generating many vertical fissures. The rate at which the claw grows can be used to calculate the date of a nutritional insult.

  10. Horizontal gene transfer among genomes: The complexity hypothesis

    OpenAIRE

    Jain, Ravi; Rivera, Maria C.; Lake, James A.

    1999-01-01

    Increasingly, studies of genes and genomes are indicating that considerable horizontal transfer has occurred between prokaryotes. Extensive horizontal transfer has occurred for operational genes (those involved in housekeeping), whereas informational genes (those involved in transcription, translation, and related processes) are seldomly horizontally transferred. Through phylogenetic analysis of six complete prokaryotic genomes and the identification of 312 sets of orthologous genes present i...

  11. Erosion Characteristics and Horizontal Variability for Small Erosion Depths in the Sacramento - San Joaquin River Delta, California, USA

    Science.gov (United States)

    Schoellhamer, D. H.; Manning, A. J.; Work, P. A.

    2015-12-01

    Cohesive sediment in the Sacramento-San Joaquin River Delta affects pelagic fish habitat, contaminant transport, and marsh accretion. Observations of suspended-sediment concentration in the delta indicate that about 0.05 to 0.20 kg/m2 are eroded from the bed during a tidal cycle. If erosion is horizontally uniform, the erosion depth is about 30 to 150 microns, the typical range in diameter of suspended flocs. Application of an erosion microcosm produces similarly small erosion depths. In addition, core erodibility in the microcosm calculated with a horizontally homogeneous model increases with depth, contrary to expectations for a consolidating bed, possibly because the eroding surface area increases as applied shear stress increases. Thus, field observations and microcosm experiments, combined with visual observation of horizontally varying biota and texture at the surface of sediment cores, indicate that a conceptual model of erosion that includes horizontally varying properties may be more appropriate than assuming horizontally homogeneous erosive properties. To test this hypothesis, we collected five cores and measured the horizontal variability of shear strength within each core in the top 5.08 cm with a shear vane. Small tubes built by a freshwater worm and macroalgae were observed on the surface of all cores. The shear vane was inserted into the sediment until the top of the vane was at the top of the sediment, torque was applied to the vane until the sediment failed and the vane rotated, and the corresponding dial reading in Nm was recorded. The dial reading was assumed to be proportional to the surface strength. The horizontal standard deviation of the critical shear stress was about 30% of the mean. Results of the shear vane test provide empirical evidence that surface strength of the bed varies horizontally. A numerical simulation of erosion with an areally heterogeneous bed reproduced erosion characteristics observed in the microcosm.

  12. Geological background of the estimation of natural stresses in soil body

    Directory of Open Access Journals (Sweden)

    Chernyshev Sergey Nikolaevich

    2015-01-01

    Full Text Available Initial and boundary conditions are always given for solving the problem of calculating the interaction of tunnels and other underground structures with soil and rocks. The same conditions are set for calculating the surface buildings. These initial data for calculation are divided into three groups: 1 the geometrical shape of the layers of rocks (geological structure; 2 the parameters of the strength and compressibility of rocks; 3 compressive stresses in the array. These data all over the world are set with engineering surveys. In engineering surveys there are good methods of determining the source of the data 1 and 2. But there is no available methodology for determining the natural stress state. Therefore, compressive and tensile stresses are usually determined by mathematical modeling. The calculation of the compressive stresses is done on the basis of the following hypotheses: compressive stresses are created by the weight of rocks; they go down in proportion to the density of rocks; the main normal stress is has a vertical direction; normal stress in horizontal direction is smaller. The value of the horizontal stress is was calculated using Poisson’s ratio. This hypothesis of the nineteenth century was used another 50 years ago, when it was not known exactly about the movement of the continents and when compressive stresses in the earth’s crust have not yet been measured. Today a universal application of this hypothesis is not correct. Now the application of this hypothesis in many cases is not correct. In this research paper an attempt is made to specify the area, in which the above hypothesis can be used. This is done on the basis of current scientific evidence. Abroad this way of calculating tunnels and other underground structures and bases of buildings should be done taking into account the real field of natural stresses. The geological characteristics of the location of the axes of stresses in soil body are based on the study of

  13. Excitation of the shear horizontal mode in a monolayer by inelastic helium atom scattering

    DEFF Research Database (Denmark)

    Bruch, L. W.; Hansen, Flemming Yssing

    2005-01-01

    Inelastic scattering of a low-energy atomic helium beam (HAS) by a physisorbed monolayer is treated in the one-phonon approximation using a time-dependent wave,packet formulation. The calculations show that modes with shear horizontal polarization can be excited near high symmetry azimuths...... experimental trends for relative excitation probability of the shear horizontal and longitudinal acoustic phonon branches. The inelastic scattering at beam energies near 8 meV is exceedingly sensitive to small misalignment between the scattering plane and the high symmetry directions of the monolayer solid...

  14. Direct renin inhibitor ameliorates insulin resistance by improving insulin signaling and oxidative stress in the skeletal muscle from post-infarct heart failure in mice.

    Science.gov (United States)

    Fukushima, Arata; Kinugawa, Shintaro; Takada, Shingo; Matsumoto, Junichi; Furihata, Takaaki; Mizushima, Wataru; Tsuda, Masaya; Yokota, Takashi; Matsushima, Shouji; Okita, Koichi; Tsutsui, Hiroyuki

    2016-05-15

    Insulin resistance can occur as a consequence of heart failure (HF). Activation of the renin-angiotensin system (RAS) may play a crucial role in this phenomenon. We thus investigated the effect of a direct renin inhibitor, aliskiren, on insulin resistance in HF after myocardial infarction (MI). MI and sham operation were performed in male C57BL/6J mice. The mice were divided into 4 groups and treated with sham-operation (Sham, n=10), sham-operation and aliskiren (Sham+Aliskiren; 10mg/kg/day, n=10), MI (n=11), or MI and aliskiren (MI+Aliskiren, n=11). After 4 weeks, MI mice showed left ventricular dilation and dysfunction, which were not affected by aliskiren. The percent decrease of blood glucose after insulin load was significantly smaller in MI than in Sham (14±5% vs. 36±2%), and was ameliorated in MI+Aliskiren (34±5%) mice. Insulin-stimulated serine-phosphorylation of Akt and glucose transporter 4 translocation were decreased in the skeletal muscle of MI compared to Sham by 57% and 69%, and both changes were ameliorated in the MI+Aliskiren group (91% and 94%). Aliskiren administration in MI mice significantly inhibited plasma renin activity and angiotensin II (Ang II) levels. Moreover, (pro)renin receptor expression and local Ang II production were upregulated in skeletal muscle from MI and were attenuated in MI+Aliskiren mice, in tandem with a decrease in superoxide production and NAD(P)H oxidase activities. In conclusion, aliskiren ameliorated insulin resistance in HF by improving insulin signaling in the skeletal muscle, at least partly by inhibiting systemic and (pro)renin receptor-mediated local RAS activation, and subsequent NAD(P)H oxidase-induced oxidative stress. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. A novel dataset on horizontal property rights in 126 jurisdictions.

    Science.gov (United States)

    Dari-Mattiacci, Giuseppe; Guerriero, Carmine

    2017-04-01

    The law and the economy are deeply influenced by horizontal property rights, which are the rules regulating legal direct and indirect takings between private parties. To foster research on the determinants and impact of these institutions, we illustrate here a novel data set partially employed in (Dari-Mattiacci, Giuseppe, Carmine Guerriero, 2015; Dari-Mattiacci, Giuseppe, Carmine Guerriero, Zhenxing Huang, 2016) [3], [4], and (Guerriero Carmine, 2016) [6] and describing the acquisition of ownership through adverse possession of personal and real property and the use of government takings to transfer real property from a private party to another private party in 126 jurisdictions. These data are based on the laws and judicial decisions prevailing in each jurisdiction between 1981 and 2011.

  16. Kinetics of carbendazim degradation in a horizontal tubular biofilm reactor.

    Science.gov (United States)

    Alvarado-Gutiérrez, María Luisa; Ruiz-Ordaz, Nora; Galíndez-Mayer, Juvencio; Santoyo-Tepole, Fortunata; Curiel-Quesada, Everardo; García-Mena, Jaime; Ahuatzi-Chacón, Deifilia

    2017-04-01

    The fungicide carbendazim is an ecotoxic agent affecting aquatic biota. Due to its suspected hormone-disrupting effects, it is considered a "priority hazard substance" by the Water Framework Directive of the European Commission, and its degradation is of major concern. In this work, a horizontal tubular biofilm reactor (HTBR) operating in plug-flow regime was used to study the kinetics of carbendazim removal by an acclimated microbial consortium. The reactor was operated in steady state continuous culture at eight different carbendazim loading rates. The concentrations of the fungicide were determined at several distances of the HTBR. At the loading rates tested, the highest instantaneous removal rates were observed in the first section of the tubular biofilm reactor. No evidence of inhibition of the catabolic activity of the microbial community was found. Strains of the genera Flectobacillus, Klebsiella, Stenotrophomonas, and Flavobacterium were identified in the biofilm; the last three degrade carbendazim in axenic culture.

  17. A novel dataset on horizontal property rights in 126 jurisdictions

    Directory of Open Access Journals (Sweden)

    Giuseppe Dari-Mattiacci

    2017-04-01

    Full Text Available The law and the economy are deeply influenced by horizontal property rights, which are the rules regulating legal direct and indirect takings between private parties. To foster research on the determinants and impact of these institutions, we illustrate here a novel data set partially employed in (Dari-Mattiacci, Giuseppe, Carmine Guerriero, 2015; Dari-Mattiacci, Giuseppe, Carmine Guerriero, Zhenxing Huang, 2016 [3,4], and (Guerriero Carmine, 2016 [6] and describing the acquisition of ownership through adverse possession of personal and real property and the use of government takings to transfer real property from a private party to another private party in 126 jurisdictions. These data are based on the laws and judicial decisions prevailing in each jurisdiction between 1981 and 2011.

  18. Search for horizontal bosons at the SSC

    Energy Technology Data Exchange (ETDEWEB)

    Albright, C.H.; Deshpande, N.G.; Gunion, J.F.; Haber, H.E.

    1984-01-01

    The production process anti p p ..-->.. l/sup -/l'/sup +/ + X, where the leptons belong to two different generations and X refers to spectator jets, provides a clear signature for horizontal (generation-changing) bosons when the leptons are emitted nearly back-to-back and p/sub T//sup miss/ = 0. Cross sections and p/sub T/ distributions for each lepton are presented, and discovery limits on M/sub H/ are extracted for several different channels.

  19. Variation in terminology: capoeira in Belo Horizonte

    Directory of Open Access Journals (Sweden)

    César Nardelli Cambraia

    2014-12-01

    Full Text Available In this pilot study we analyzed the variation in the terminology of capoeira in Belo Horizonte. The terms referring to 69 videotaped movements of capoeira were collected from 10 informants (5 men and 5 women, aged between 25 and 32 years, capoeira teachers. As a result we obtained 294 different terms whose patterns of variation are distributed among 15 types. We tested the hypothesis that the figurative terms tend to be replaced by non-figurative ones, and it was confirmed by the collected data. This trend was the result of a search for transparency in terminology, making the terms more descriptive in relation to capoeira’s movements.

  20. A New Numerical Simulation technology of Multistage Fracturing in Horizontal Well

    Science.gov (United States)

    Cheng, Ning; Kang, Kaifeng; Li, Jianming; Liu, Tao; Ding, Kun

    2017-11-01

    Horizontal multi-stage fracturing is recognized the effective development technology of unconventional oil resources. Geological mechanics in the numerical simulation of hydraulic fracturing technology occupies very important position, compared with the conventional numerical simulation technology, because of considering the influence of geological mechanics. New numerical simulation of hydraulic fracturing can more effectively optimize the design of fracturing and evaluate the production after fracturing. This paper studies is based on the three-dimensional stress and rock physics parameters model, using the latest fluid-solid coupling numerical simulation technology to engrave the extension process of fracture and describes the change of stress field in fracturing process, finally predict the production situation.

  1. Feedback from luminosity horizontal cells mediates depolarizing responses of chromaticity horizontal cells in the Xenopus retina.

    OpenAIRE

    Witkovsky, P; Gabriel, R; Krizaj, D; Akopian, A.

    1995-01-01

    It has been proposed that the depolarizing responses of chromaticity horizontal cells (C-HCs) to red light depend on a feedback signal from luminosity horizontal cells (L-HCs) to short-wavelength-sensitive cones in the retinas of lower vertebrates. In this regard we studied the C-HCs of the Xenopus retina. C-HCs and L-HCs were identified by physiological criteria and then injected with neurobiotin. The retina then was incubated with peanut agglutinin, which stains red-but not blue-sensitive c...

  2. Radiologically defining horizontal gaze using EOS imaging-a prospective study of healthy subjects and a retrospective audit.

    Science.gov (United States)

    Hey, Hwee Weng Dennis; Tan, Kimberly-Anne; Ho, Vivienne Chien-Lin; Azhar, Syifa Bte; Lim, Joel-Louis; Liu, Gabriel Ka-Po; Wong, Hee-Kit

    2017-10-18

    As sagittal alignment of the cervical spine is important for maintaining horizontal gaze, it is important to determine the former for surgical correction. However, horizontal gaze remains poorly-defined from a radiological point of view. The objective of this study was to establish radiological criteria to define horizontal gaze. This study was conducted at a tertiary health-care institution over a 1-month period. A prospective cohort of healthy patients was used to determine the best radiological criteria for defining horizontal gaze. A retrospective cohort of patients without rigid spinal deformities was used to audit the incidence of horizontal gaze. Two categories of radiological parameters for determining horizontal gaze were tested: (1) the vertical offset distances of key identifiable structures from the horizontal gaze axis and (2) imaginary lines convergent with the horizontal gaze axis. Sixty-seven healthy subjects underwent whole-body EOS radiographs taken in a directed standing posture. Horizontal gaze was radiologically defined using each parameter, as represented by their means, 95% confidence intervals (CIs), and associated 2 standard deviations (SDs). Subsequently, applying the radiological criteria, we conducted a retrospective audit of such radiographs (before the implementation of a strict radioimaging standardization). The mean age of our prospective cohort was 46.8 years, whereas that of our retrospective cohort was 37.2 years. Gender was evenly distributed across both cohorts. The four parameters with the lowest 95% CI and 2 SD were the distance offsets of the midpoint of the hard palate (A) and the base of the sella turcica (B), the horizontal convergents formed by the tangential line to the hard palate (C), and the line joining the center of the orbital orifice with the internal occipital protuberance (D). In the prospective cohort, good sensitivity (>98%) was attained when two or more parameters were used. Audit using Criterion B

  3. A critical discussion of the electromagnetic radiation (EMR method to determine stress orientations within the crust

    Directory of Open Access Journals (Sweden)

    M. Krumbholz

    2012-11-01

    Full Text Available In recent years, the electromagnetic radiation (EMR method has been used to detect faults and to determine main horizontal stress directions from variations in intensities and directional properties of electromagnetic emissions, which are assumed to be generated during micro-cracking. Based on a large data set taken from an area of about 250 000 km2 in Northern Germany, Denmark, and southern Sweden with repeated measurements at one location during a time span of about 1.5 yr, the method was systematically tested. Reproducible observations of temporary changes in the signal patterns, as well as a strongly concentric spatial pattern of the main directions of the magnetic component of the EMR point to very low frequency (VLF transmitters as the main source and hence raise serious concerns about the applicability of the method to determine recent crustal stresses. We conclude that the EMR method, at its current stage of development, does not allow determination of the main horizontal stress directions.

  4. Posttraumatic Stress Disorder

    Science.gov (United States)

    ... stress can lead to PTSD. It often develops after a direct experience in which someone is seriously injured or threatened with injury or death. It also can happen to people who witness stressful events or learn ...

  5. Applying GPS to check horizontal control quality

    Directory of Open Access Journals (Sweden)

    Jakub Vincent

    2004-03-01

    Full Text Available GPS technologies can also be used for check quality in available horizontal point set with coordinates CJ of the frame S-JTSK. When survey and setting-out tasks should be performed in certain area, one can found in it allways some points of the fundamental and detail state controls. To use these points for some actual aims, it is necessary to investigate their compatibility (among the point mark positions and the point coordinate of control points. This can be done using GPS surveying that may be at the same time employed to determine the new point in the relevant area.Principle of quality investigatingf an existing control is founded on determination of point coordinates CJt from GPS measurements. Then, based on discrepancies among the "official" netpoint coordinates CJ and coordinates CJt "given by GPS", it can be estimated the degree and the real compatibility dislocations in the network structure of the existing points.Realisation procedure for the introduced investigation is demonstrated on GPS checking (by SOKKIA STRATUS receivers horizontal control for reconstruction of a railway bridge on river Bodrog in East Slovakia.It can be shown from the results in Table 3, that points P3 and P7 are useless due to their incompatibility (inconsistency in the inspected point set. For other 7 points (Table 7 the average measure of incompatibility reads 9.8 mm that make possible applying these points for precise setting-out

  6. Effects of reverse waves on the hydrodynamic pressure acting on a dual porous horizontal plate

    Directory of Open Access Journals (Sweden)

    Kweon Hyuck-Min

    2014-03-01

    Full Text Available The seaward reverse wave, occurring on the submerged dual porous horizontal plate, can contribute to the reduction of the transmitted wave as it reflects the propagating wave. However, the collision between the propa¬gating and seaward reverse waves increases the water level and acts as a weight on the horizontal plate. This study investigated the characteristics of the wave pressure created by the seaward reverse wave through the analysis of expe¬rimental data. The analysis confirmed the following results: 1 the time series of the wave pressure showed reverse phase phenomena due to the collision, and the wave pressures acted simultaneously on both upper and lower surfaces of the horizontal plate; 2 the horizontal plate became repeatedly compressed and tensile before and after the occur¬rence of the seaward reverse wave; and 3 the seaward reverse wave created the total wave pressure to the maximum towards the direction of gravity, primarily on the upper plate. It was also confirmed that the wave distributions showed a similar trend to the wave steepness. Such outcome of the analysis will provide basic information to the structural analysis of the horizontal plate as a wave dissipater of the steel-type breakwater (STB.

  7. Effects of reverse waves on the hydrodynamic pressure acting on a dual porous horizontal plate

    Directory of Open Access Journals (Sweden)

    Hyuck-Min Kweon

    2014-03-01

    Full Text Available The seaward reverse wave, occurring on the submerged dual porous horizontal plate, can contribute to the reduction of the transmitted wave as it reflects the propagating wave. However, the collision between the propagating and seaward reverse waves increases the water level and acts as a weight on the horizontal plate. This study investigated the characteristics of the wave pressure created by the seaward reverse wave through the analysis of experimental data. The analysis confirmed the following results: 1 the time series of the wave pressure showed reverse phase phenomena due to the collision, and the wave pressures acted simultaneously on both upper and lower surfaces of the horizontal plate; 2 the horizontal plate became repeatedly compressed and tensile before and after the occurrence of the seaward reverse wave; and 3 the seaward reverse wave created the total wave pressure to the maximum towards the direction of gravity, primarily on the upper plate. It was also confirmed that the wave distributions showed a similar trend to the wave steepness. Such outcome of the analysis will provide basic information to the structural analysis of the horizontal plate as a wave dissipater of the steel-type breakwater (STB.

  8. Horizontal dual-point excitation and fatigue test of full-scale wind turbine blade

    Science.gov (United States)

    Pan, Zujin; Wu, Jianzhong; Zhao, Xinhua; Xie, Yan

    2017-06-01

    In order to meet the requirements of large-blade fatigue testing, a horizontal dual-point linear exciter loading program is developed. In this paper, Lagrange’s equation and FEM method are used to simulate the dual-point excitation theory model. The horizontal dual-point excitation characteristics of the blade are validated by the experimental method. The relationship among the dual-point exciting force, cycle time and bending moment during blade fatigue test in flap wise direction is studied. The advantages of horizontal dual-point excitation in blade fatigue test are analysed. Compared with vertical single-point excitation when the equal bending moment is reached, the exciting force and energy consumption required for dual-point excitation are reduced by 60.0% and 96.8%. Resonant frequency of the test system is improved by reducing the dead weight because of dual-point horizontal excitation. The entire blade fatigue test time is shortened by 7.4%. The use of horizontal dual-point excitation could save energy and shorten the entire fatigue test time.

  9. THE FIELD OF RECENT TECTONIC STRESSES IN CENTRAL AND SOUTH-EASTERN ASIA

    Directory of Open Access Journals (Sweden)

    Yu. L. Rebetsky

    2014-01-01

    Global CMT Database, reconstructions based on the first catalog are mapped. In the maps showing consolidated patterns of the state of stresses, spacious areas of horizontal extension of the crust in Tibet are clearly identified. In the south, such areas are bordered by regions of horizontal compression of the crust in Himalaya; in the north and north-east, they are bordered by regions of horizontal shear of the crust in East Kunlun. According to results of calculations at stage 2 of the method of cataclastic analyses, the crust in the central part of Tibet is subject to intensive confining pressure and lateral compression that is reduced in the neighboring regions. The crust in the southern and northern parts of Pamir is also subject to horizontal extension and shear. Regions of horizontal compression are located to the north, west and south of Pamir. Regulations of the field of recent tectonic stresses of Tibet and Pamir, which are revealed in this study, can be explained by the concept of ‘tectonic spreading’ of these regions due to gravity, which causes intensive horizontal spreading of the crust in Himalaya when the southern boundary of Tibet bends outwards and spreads over the Indian ‘indenter’ moving in the north–north-eastern direction. It is suggested by the data on horizontal extension of the crust in Tibet and underthrusting shear stresses over the horizontal zones that the impact Indian ‘indenter’ does not go beyond the crust of Pamir and the crust of the central parts of Tibet which is located above the long-term active mantle plume.  

  10. Trolox and ascorbic acid reduce direct and indirect oxidative stress in the IPEC-J2 cells, an in vitro model for the porcine gastrointestinal tract.

    Science.gov (United States)

    Vergauwen, Hans; Tambuyzer, Bart; Jennes, Karen; Degroote, Jeroen; Wang, Wei; De Smet, Stefaan; Michiels, Joris; Van Ginneken, Chris

    2015-01-01

    Oxidative stress in the small intestinal epithelium is a major cause of barrier malfunction and failure to regenerate. This study presents a functional in vitro model using the porcine small intestinal epithelial cell line IPEC-J2 to examine the effects of oxidative stress and to estimate the antioxidant and regenerative potential of Trolox, ascorbic acid and glutathione monoethyl ester. Hydrogen peroxide and diethyl maleate affected the tight junction (zona occludens-1) distribution, significantly increased intracellular oxidative stress (CM-H2DCFDA) and decreased the monolayer integrity (transepithelial electrical resistance and FD-4 permeability), viability (neutral red) and wound healing capacity (scratch assay). Trolox (2 mM) and 1 mM ascorbic acid pre-treatment significantly reduced intracellular oxidative stress, increased wound healing capacity and reduced FD-4 permeability in oxidatively stressed IPEC-J2 cell monolayers. All antioxidant pre-treatments increased transepithelial electrical resistance and viability only in diethyl maleate-treated cells. Glutathione monoethyl ester (10 mM) pre-treatment significantly decreased intracellular oxidative stress and monolayer permeability only in diethyl maleate-treated cells. These data demonstrate that the IPEC-J2 oxidative stress model is a valuable tool to screen antioxidants before validation in piglets.

  11. Gravitational stresses in anisotropic rock masses

    Science.gov (United States)

    Amadei, B.; Savage, W.Z.; Swolfs, H.S.

    1987-01-01

    This paper presents closed-form solutions for the stress field induced by gravity in anisotropic rock masses. These rocks are assumed to be laterally restrained and are modelled as a homogeneous, orthotropic or transversely isotropic, linearly elastic material. The analysis, constrained by the thermodynamic requirement that strain energy be positive definite, gives the following important result: inclusion of anisotropy broadens the range of permissible values of gravity-induced horizontal stresses. In fact, for some ranges of anisotropic rock properties, it is thermodynamically admissible for gravity-induced horizontal stresses to exceed the vertical stress component; this is not possible for the classical isotropic solution. Specific examples are presented to explore the nature of the gravity-induced stress field in anisotropic rocks and its dependence on the type, degree and orientation of anisotropy with respect to the horizontal ground surface. ?? 1987.

  12. Erosion characteristics and horizontal variability for small erosion depths in the Sacramento-San Joaquin River Delta, California, USA

    Science.gov (United States)

    Schoellhamer, David H.; Manning, Andrew J.; Work, Paul

    2017-01-01

    Erodibility of cohesive sediment in the Sacramento-San Joaquin River Delta (Delta) was investigated with an erosion microcosm. Erosion depths in the Delta and in the microcosm were estimated to be about one floc diameter over a range of shear stresses and times comparable to half of a typical tidal cycle. Using the conventional assumption of horizontally homogeneous bed sediment, data from 27 of 34 microcosm experiments indicate that the erosion rate coefficient increased as eroded mass increased, contrary to theory. We believe that small erosion depths, erosion rate coefficient deviation from theory, and visual observation of horizontally varying biota and texture at the sediment surface indicate that erosion cannot solely be a function of depth but must also vary horizontally. We test this hypothesis by developing a simple numerical model that includes horizontal heterogeneity, use it to develop an artificial time series of suspended-sediment concentration (SSC) in an erosion microcosm, then analyze that time series assuming horizontal homogeneity. A shear vane was used to estimate that the horizontal standard deviation of critical shear stress was about 30% of the mean value at a site in the Delta. The numerical model of the erosion microcosm included a normal distribution of initial critical shear stress, a linear increase in critical shear stress with eroded mass, an exponential decrease of erosion rate coefficient with eroded mass, and a stepped increase in applied shear stress. The maximum SSC for each step increased gradually, thus confounding identification of a single well-defined critical shear stress as encountered with the empirical data. Analysis of the artificial SSC time series with the assumption of a homogeneous bed reproduced the original profile of critical shear stress, but the erosion rate coefficient increased with eroded mass, similar to the empirical data. Thus, the numerical experiment confirms the small-depth erosion hypothesis. A linear

  13. NUMERICAL DETERMINATION OF HORIZONTAL SETTLERS PERFORMANCE

    Directory of Open Access Journals (Sweden)

    M. M. Biliaiev

    2015-08-01

    Full Text Available Purpose.Horizontal settlers are one of the most important elements in the technological scheme of water purification. Their use is associated with the possibility to pass a sufficiently large volume of water. The important task at the stage of their designing is evaluating of their effectiveness. Calculation of the efficiency of the settler can be made by mathematical modeling. Empirical, analytical models and techniques that are currently used to solve the problem, do not allow to take into account the shape of the sump and various design features that significantly affects the loyalty to a decision on the choice of the size of the settling tank and its design features. The use of analytical models is limited only to one-dimensional solutions, does not allow accounting for nonuniform velocity field of the flow in the settler. The use of advanced turbulence models for the calculation of the hydrodynamics in the settler complex forms now requires very powerful computers. In addition, the calculation of one variant of the settler may last for dozens of hours. The aim of the paper is to build a numerical model to evaluate the effectiveness of horizontal settling tank modified design. Methodology. Numerical models are based on: 1 equation of potential flow; 2 equation of inviscid fluid vortex flow; 3 equation of viscous fluid dynamics; 4 mass transfer equation. For numerical simulation the finite difference schemes are used. The numerical calculation is carried out on a rectangular grid. For the formation of the computational domain markers are used. Findings.The models allow calculating the clarification process in the settler with different form and different configuration of baffles. Originality. A new approach to investigate the mass transfer process in horizontal settler was proposed. This approach is based on the developed CFD models. Three fluid dynamics models were used for the numerical investigation of flows and waste waters purification

  14. Phylogeny poorly predicts the utility of a challenging horizontally transferred gene in Methylobacterium strains.

    Science.gov (United States)

    Michener, Joshua K; Vuilleumier, Stéphane; Bringel, Françoise; Marx, Christopher J

    2014-06-01

    Horizontal gene transfer plays a crucial role in microbial evolution. While much is known about the mechanisms that determine whether physical DNA can be transferred into a new host, the factors determining the utility of the transferred genes are less clear. We have explored this issue using dichloromethane consumption in Methylobacterium strains. Methylobacterium extorquens DM4 expresses a dichloromethane dehalogenase (DcmA) that has been acquired through horizontal gene transfer and allows the strain to grow on dichloromethane as the sole carbon and energy source. We transferred the dcmA gene into six Methylobacterium strains that include both close and distant evolutionary relatives. The transconjugants varied in their ability to grow on dichloromethane, but their fitness on dichloromethane did not correlate with the phylogeny of the parental strains or with any single tested physiological factor. This work highlights an important limiting factor in horizontal gene transfer, namely, the capacity of the recipient strain to accommodate the stress and metabolic disruption resulting from the acquisition of a new enzyme or pathway. Understanding these limitations may help to rationalize historical examples of horizontal transfer and aid deliberate genetic transfers in biotechnology for metabolic engineering.

  15. Identification of natural fractures and in situ stress at Rantau Dedap geothermal field

    Science.gov (United States)

    Artyanto, Andika; Sapiie, Benyamin; Idham Abdullah, Chalid; Permana Sidik, Ridwan

    2017-12-01

    Rantau Dedap Area is a geothermal field which is located in Great Sumatra Fault (GSF). The fault and fracture are main factor in the permeability of the geothermal system. However, not all faults and fractures have capability of to flow the fluids. Borehole image log is depiction of the borehole conditions, it is used to identify the natural fractures and drilling induced fracture. Both of them are used to identify the direction of the fracture, direction of maximum horizontal stress (SHmax), and geomechanics parameters. The natural fractures are the results of responses to stress on a rock and permeability which controlling factor in research area. Breakouts is found in this field as a trace of drilling induced fracture due to in situ stress work. Natural fractures are strongly clustered with true strike trending which first, second, and third major direction are N170°E – N180°E (N-S), N60°E – N70°E (NE-SW), and N310°E – N320°E (NW-SE), while the dominant dip is 80° –90°. Based on borehole breakout analysis, maximum horizontal stress orientation is identified in N162°E – N204°E (N-S) and N242°E (NE-SW) direction. It’s constantly similar with regional stress which is affected by GSF. Several parameters have been identified and analyzed are SHmax, SHmin, and Sy. It can be concluded that Rantau Dedap Geothermal Field is affected by strike-slip regime. The determination of in situ stress and natural fractures are important to study the pattern of permeability which is related to the fault in reservoir of this field.

  16. Horizontal Gene Transfer, Dispersal and Haloarchaeal Speciation

    Science.gov (United States)

    Papke, R. Thane; Corral, Paulina; Ram-Mohan, Nikhil; de la Haba, Rafael R.; Sánchez-Porro, Cristina; Makkay, Andrea; Ventosa, Antonio

    2015-01-01

    The Halobacteria are a well-studied archaeal class and numerous investigations are showing how their diversity is distributed amongst genomes and geographic locations. Evidence indicates that recombination between species continuously facilitates the arrival of new genes, and within species, it is frequent enough to spread acquired genes amongst all individuals in the population. To create permanent independent diversity and generate new species, barriers to recombination are probably required. The data support an interpretation that rates of evolution (e.g., horizontal gene transfer and mutation) are faster at creating geographically localized variation than dispersal and invasion are at homogenizing genetic differences between locations. Therefore, we suggest that recurrent episodes of dispersal followed by variable periods of endemism break the homogenizing forces of intrapopulation recombination and that this process might be the principal stimulus leading to divergence and speciation in Halobacteria. PMID:25997110

  17. Horizontal gene exchange in environmental microbiota

    Directory of Open Access Journals (Sweden)

    Rustam I Aminov

    2011-07-01

    Full Text Available Horizontal gene transfer (HGT plays an important role in the evolution of life on the Earth. This view is supported by numerous occasions of HGT that are recorded in the genomes of all three domains of living organisms. HGT-mediated rapid evolution is especially noticeable among the Bacteria, which demonstrate formidable adaptability in the face of recent environmental changes imposed by human activities, such as the use of antibiotics, industrial contamination, and intensive agriculture. At the heart of the HGT-driven bacterial evolution and adaptation are highly sophisticated natural genetic engineering tools in the form of a variety of mobile genetic elements (MGEs. The main aim of this review is to give a brief account of the occurrence and diversity of MGEs in natural ecosystems and of the environmental factors that may affect MGE-mediated HGT.

  18. Modelling the horizontal steam generator with APROS

    Energy Technology Data Exchange (ETDEWEB)

    Ylijoki, J. [VTT Energy, Espoo (Finland); Palsinajaervi, C.; Porkholm, K. [IVO International Ltd, Vantaa (Finland)

    1995-12-31

    In this paper the capability of the five- and six-equation models of the simulation code APROS to simulate the behaviour of the horizontal steam generator is discussed. Different nodalizations are used in the modelling and the results of the stationary state runs are compared. Exactly the same nodalizations have been created for the five- and six-equation models. The main simulation results studied in this paper are void fraction and mass flow distributions in the secondary side of the steam generator. It was found that quite a large number of simulation volumes is required to simulate the distributions with a reasonable accuracy. The simulation results of the different models are presented and their validity is discussed. (orig.). 4 refs.

  19. Horizontal Gene Transfer, Dispersal and Haloarchaeal Speciation

    Directory of Open Access Journals (Sweden)

    R. Thane Papke

    2015-05-01

    Full Text Available The Halobacteria are a well-studied archaeal class and numerous investigations are showing how their diversity is distributed amongst genomes and geographic locations. Evidence indicates that recombination between species continuously facilitates the arrival of new genes, and within species, it is frequent enough to spread acquired genes amongst all individuals in the population. To create permanent independent diversity and generate new species, barriers to recombination are probably required. The data support an interpretation that rates of evolution (e.g., horizontal gene transfer and mutation are faster at creating geographically localized variation than dispersal and invasion are at homogenizing genetic differences between locations. Therefore, we suggest that recurrent episodes of dispersal followed by variable periods of endemism break the homogenizing forces of intrapopulation recombination and that this process might be the principal stimulus leading to divergence and speciation in Halobacteria.

  20. Horizontal gene transfer, dispersal and haloarchaeal speciation.

    Science.gov (United States)

    Papke, R Thane; Corral, Paulina; Ram-Mohan, Nikhil; Haba, Rafael R de la; Sánchez-Porro, Cristina; Makkay, Andrea; Ventosa, Antonio

    2015-05-19

    The Halobacteria are a well-studied archaeal class and numerous investigations are showing how their diversity is distributed amongst genomes and geographic locations. Evidence indicates that recombination between species continuously facilitates the arrival of new genes, and within species, it is frequent enough to spread acquired genes amongst all individuals in the population. To create permanent independent diversity and generate new species, barriers to recombination are probably required. The data support an interpretation that rates of evolution (e.g., horizontal gene transfer and mutation) are faster at creating geographically localized variation than dispersal and invasion are at homogenizing genetic differences between locations. Therefore, we suggest that recurrent episodes of dispersal followed by variable periods of endemism break the homogenizing forces of intrapopulation recombination and that this process might be the principal stimulus leading to divergence and speciation in Halobacteria.

  1. Horizontal gene transfer in eukaryotic plant pathogens.

    Science.gov (United States)

    Soanes, Darren; Richards, Thomas A

    2014-01-01

    Gene transfer has been identified as a prevalent and pervasive phenomenon and an important source of genomic innovation in bacteria. The role of gene transfer in microbial eukaryotes seems to be of a reduced magnitude but in some cases can drive important evolutionary innovations, such as new functions that underpin the colonization of different niches. The aim of this review is to summarize published cases that support the hypothesis that horizontal gene transfer (HGT) has played a role in the evolution of phytopathogenic traits in fungi and oomycetes. Our survey of the literature identifies 46 proposed cases of transfer of genes that have a putative or experimentally demonstrable phytopathogenic function. When considering the life-cycle steps through which a pathogen must progress, the majority of the HGTs identified are associated with invading, degrading, and manipulating the host. Taken together, these data suggest HGT has played a role in shaping how fungi and oomycetes colonize plant hosts.

  2. Influence of the lithosphere-asthenosphere boundary on the stress field northwest of the Alps

    Science.gov (United States)

    Maury, J.; Cornet, F. H.; Cara, M.

    2014-11-01

    In 1356, a magnitude 6-7 earthquake occurred near Basel, in Switzerland. But recent compilations of GPS measurements reveal that measured horizontal deformation rates in northwestern continental Europe are smaller than error bars on the measurements, proving present tectonic activity, if any, is very small in this area. We propose to reconcile these apparently antinomic observations with a mechanical model of the lithosphere that takes into account the geometry of the lithosphere-asthenosphere boundary, assuming that the only loading mechanism is gravity. The lithosphere is considered to be an elastoplastic material satisfying a Von Mises plasticity criterion. The model, which is 400 km long, 360 km wide and 230 km thick, is centred near Belfort in eastern France, with its width oriented parallel to the N145°E direction. It also takes into account the real topography of both the ground surface and that of the Moho discontinuity. Not only does the model reproduce observed principal stress directions orientations, it also identifies a plastic zone that fits roughly the most seismically active domain of the region. Interestingly, a somewhat similar stress map may be produced by considering an elastic lithosphere and an ad-hoc horizontal `tectonic' stress field. However, for the latter model, examination of the plasticity criterion suggests that plastic deformation should have taken place. It is concluded that the present-day stress field in this region is likely controlled by gravity and rheology, rather than by active Alpine tectonics.

  3. Demonstration of river crossing technology for installation of environmental horizontal wells: AMH-6 and AMH-7 installation report

    Energy Technology Data Exchange (ETDEWEB)

    Moore, D. B.

    1993-07-01

    The Department of Energy`s (DOE) Office of Technology Development initiated an integrated demonstration of innovative technologies and systems for cleanup of volatile organic compounds (VOCs) in soils and groundwater. This drilling project is part of the directional drilling task for the integrated technology demonstration at the Savannah River Site (SRS). One of the objectives of the drilling task is the demonstration of multiple drilling technologies. The technologies can then be compared and evaluated in terms of technical performance and cost effectiveness. Petroleum horizontal well technology and utility industry horizontal well technology have been previously demonstrated at the SRS. The petroleum industry directional drilling technology was demonstrated by Eastman Christensen Environmental Corporation (ECEC). ECEC directionally drilled and installed four horizontal wells in the M Area. Charles Machine Works, working with Sandia National Laboratory, demonstrated a utility industry directional drilling technology by installing one horizontal well in the M Area. The demonstration that is the subject of this report involved river crossing horizontal well technology for the installation of two M-Area Settling Basin soil gas extraction wells.

  4. Vertical and horizontal surface displacements near Jakobshavn Isbræ driven by melt-induced and dynamic ice loss

    DEFF Research Database (Denmark)

    Nielsen, Karina; Khan, Shfaqat Abbas; Spada, G.

    2013-01-01

    We analyze Global Positioning System (GPS) time series of relative vertical and horizontal surface displacements from 2006 to 2012 at four GPS sites located between ∼5 and ∼150 km from the front of Jakobshavn Isbræ (JI) in west Greenland. Horizontal displacements during 2006–2010 at KAGA, ILUL, a...... to 2006–2010. The sudden change in vertical and horizontal displacements is due to enhanced melt-induced ice loss in 2010 and 2012....... of surface elevations from 2006, 2009, and 2010. However, horizontal displacements during 2010–2012 at KAGA and ILUL are directed more towards the west suggesting a change in the spatial distribution of the ice mass loss. In addition, we observe an increase in the uplift rate during 2010–2012 as compared...

  5. Characterization of interfacial waves in horizontal core-annular flow

    Science.gov (United States)

    Tripathi, Sumit; Bhattacharya, Amitabh; Singh, Ramesh; Tabor, Rico F.

    2016-11-01

    In this work, we characterize interfacial waves in horizontal core annular flow (CAF) of fuel-oil and water. Experimental studies on CAF were performed in an acrylic pipe of 15.5mm internal diameter, and the time evolution of the oil-water interface shape was recorded with a high speed camera for a range of different flow-rates of oil (Qo) and water (Qw). The power spectrum of the interface shape shows a range of notable features. First, there is negligible energy in wavenumbers larger than 2 π / a , where a is the thickness of the annulus. Second, for high Qo /Qw , there is no single dominant wavelength, as the flow in the confined annulus does not allow formation of a preferred mode. Third, for lower Qo /Qw , a dominant mode arises at a wavenumber of 2 π / a . We also observe that the power spectrum of the interface shape depends weakly on Qw, and strongly on Qo, perhaps because the net shear rate in the annulus appears to depend weakly on Qw as well. We also attempt to build a general empirical model for CAF by relating the interfacial stress (calculated via the mean pressure gradient) to the flow rate in the annulus, the annular thickness and the core velocity. Authors are thankful to Orica Mining Services (Australia) for the financial support.

  6. The energetics of rotating wind-forced horizontal convection

    Science.gov (United States)

    Zemskova, Varvara; White, Brian; Scotti, Alberto

    2017-11-01

    We present numerical results for rotating, wind-forced horizontal convection as a simple model for the Southern Ocean branch of the Meridional Overturning Circulation. The flow is driven by differential buoyancy forcing applied at the top surface, with cooling at one end (to represent the pole) and warming at the other (the equatorial region) and a zonally re-entrant channel to represent the Antarctic Circumpolar Current. Zonal wind forcing is applied with a similar pattern to the westerlies and with varying magnitude relative to the buoyancy forcing. The problem is solved numerically using a 3D DNS model based on a finite-volume solver for the Boussinesq Navier-Stokes equations with rotation. The overall dynamics, such as large-scale overturning, baroclinic eddying, turbulent mixing, and energy cascades are investigated using the local Available Potential Energy framework introduced in [Scotti and White, JFM, 2014]. We find that the magnitude and shape of the zonal wind stress profile are important to the spatial pattern of the overturning circulation. However, the essential circulation and the energetics in cases with wind are similar to the base case with buoyancy forcing alone, suggesting that surface APE generation by buoyancy forcing is dominant in setting the circulation. This research is part of the Blue Waters sustained-petascale computing project, supported by the NSF (awards OCI-0725070, ACI-1238993 and ACI-14-44747) and the state of Illinois.

  7. Effect of stress fields on magma chamber stability and the formation of collapse calderas

    Science.gov (United States)

    Bosworth, William; Burke, Kevin; Strecker, Manfred

    2003-08-01

    The summits of many of the Earth's and other planets' larger volcanoes are occupied by calderas that formed by collapse into an evacuating, underlying magma chamber. These collapse calderas are typically several tens of square kilometers in area and are commonly elliptical in shape. We show that the long axes of late Quaternary collapse calderas in the Kenya rift valley, the western Basin and Range province, the Snake River-Yellowstone Plateau, and the Iceland rift zone are parallel to the upper crustal minimum horizontal stress direction (Sh) as determined by independent criteria. We suggest that circular magma chambers beneath these volcanoes became elliptical by stress-induced spalling of their chamber walls, by a mechanism that is analogous to the formation of breakouts in boreholes and tunnels. In breakouts, the hole becomes elongate parallel to the far-field minimum stress. In the Kenya rift, Late Pleistocene caldera collapse was accompanied by a 45° rotation of Sh and an increase in the magnitude of the maximum horizontal stress (SH). The breakout model predicts increasingly unstable caldera walls under these conditions, a possible explanation for the sudden appearance of so many collapse events in a volcanic setting that had never experienced them before. This mechanism of stress change-induced collapse may have played a role in other caldera settings.

  8. Crustal stress field perturbations in the continental margin around the Korean Peninsula and Japanese islands

    Science.gov (United States)

    Lee, Junhyung; Hong, Tae-Kyung; Chang, Chandong

    2017-10-01

    Seismic activity and focal mechanisms are governed by the effective stress field that is a combined result of regional tectonic processes and local stress perturbation. This study investigates the regional variation in the stress field in the eastern continental margin of the Eurasian plate around the Korean Peninsula and Japanese islands using a damped stress inversion technique based on the focal mechanism solutions of regional earthquakes. The dominant compressional stress is directed ENE-WSW around the Korean Peninsula and eastern China, E-W at the central East Sea and northern and southern Japan, NW-SE at central Japan, and N-S around the northern Nankai trough. The dominant compression direction changes rapidly in the East Sea and Japanese islands, which may be due to the combined effects of tectonic loading in the subduction zones off the Japanese islands and the India-Eurasia plate boundary. The crustal stress fields around the subduction zones off the Japanese islands present characteristic depth-dependent orientations. The orientations of the largest horizontal stress components, σH, in the subduction zones are subparallel with the plate convergence directions at shallow depths. The σH orientations are observed to rotate clockwise with the depth owing to slab subduction and lithospheric deformation. The regional stress field around the Japanese islands was perturbed temporally by the 2011 M9.0 Tohoku-Oki megathrust earthquake. The regional stress field was recovered in a couple of years. The stress field and tectonic structures are mutually affected, causing stress field distortion and a localized mixture of earthquakes in different faulting types.

  9. Horizontal gene transfer in evolution: facts and challenges

    OpenAIRE

    Boto, Luis

    2009-01-01

    The contribution of horizontal gene transfer to evolution has been controversial since it was suggested to be a force driving evolution in the microbial world. In this paper, I review the current standpoint on horizontal gene transfer in evolutionary thinking and discuss how important horizontal gene transfer is in evolution in the broad sense, and particularly in prokaryotic evolution. I review recent literature, asking, first, which processes are involved in the evolutionary success of tran...

  10. Capillary-contacting horizontal cells in the rodent retina

    OpenAIRE

    Mojumder, Deb Kumar

    2008-01-01

    Horizontal cells, the interneurons in the distal retina, provide feedback control of the photoreceptor synaptic output at the first synapse in the visual pathway. This article, using immunohistological and confocal microscopy techniques, presents anatomical evidence that in rat and mouse retina, the horizontal cell processes are in contact with retinal capillaries as are retinal glial cells. This glia-like property of horizontal cells in these two species, also previously reported in tree shr...

  11. ROS-induced oxidative stress and apoptosis-like event directly affect the cell viability of cryopreserved embryogenic callus in Agapanthus praecox.

    Science.gov (United States)

    Zhang, Di; Ren, Li; Chen, Guan-Qun; Zhang, Jie; Reed, Barbara M; Shen, Xiao-Hui

    2015-09-01

    Oxidative stress and apoptosis-like programmed cell death, induced in part by H 2 O 2 , are two key factors that damage cells during plant cryopreservation. Their inhibition can improve cell viability. We hypothesized that oxidative stress and apoptosis-like event induced by ROS seriously impact plant cell viability during cryopreservation. This study documented changes in cell morphology and ultrastructure, and detected dynamic changes in ROS components (O 2 (·-) , H2O2 and OH·), antioxidant systems, and programmed cell death (PCD) events during embryonic callus cryopreservation of Agapanthus praecox. Plasmolysis, organelle ultrastructure changes, and increases in malondialdehyde (a membrane lipid peroxidation product) suggested that oxidative damage and PCD events occurred at several early cryopreservation steps. PCD events including autophagy, apoptosis-like, and necrosis also occurred at later stages of cryopreservation, and most were apoptosis. H2O2 is the most important ROS molecule mediating oxidative damage and affecting cell viability, and catalase and AsA-GSH cycle are involved in scavenging the intracellular H2O2 and protecting the cells against stress damage in the whole process. Gene expression studies verified changes of antioxidant system and PCD-related genes at the main steps of the cryopreservation process that correlated with improved cell viability. Reducing oxidative stress or inhibition of apoptosis-like event by deactivating proteases improved cryopreserved cell viability from 49.14 to 86.85 % and 89.91 %, respectively. These results verify our model of ROS-induced oxidative stress and apoptosis-like event in plant cryopreservation. This study provided a novel insight into cell stress response mechanisms in cryopreservation.

  12. From the horizontal to the vertical genealogical image of the Nemanjić dynasty

    Directory of Open Access Journals (Sweden)

    Vojvodić Dragan

    2007-01-01

    iconographic scheme. It is possible to notice significant contextual differences between the two types of the Serbian dynastic picture, especially regarding the presentation of the rulers' wives or the rulers' daughters, or male relatives from the lateral branches. A number of questions that had earlier been of particular importance, such as the order of succession to the throne through the direct bloodline, became submerged in a multitude of new messages and slowly lost significance. The 'vertical' family tree of the Nemanjići focused far more on the proclamation of general dynastic messages. As a more developed and complex picture than the 'horizontal' genealogy, it was able to convey more carefully nuanced details about what effect dynastic history had on the awareness of the court. Apart from that, in contrast to the presentations of XIII century 'horizontal genealogies' that illustrated Nemanja and his direct successors as monks, the new type of dynastic picture quite clearly stressed the 'imperial' nature of the ruler's family. A similar change of meaning can also be noted in contemporaneous royal charters. One should view this interesting phenomenon through the prism of the increasingly tangible influences of Byzantine imperial ideology on Serbian dynastic thought. The distinct influence of Byzantine perceptions can also be recognized in the motive of the ruler's investiture being performed by God himself, depicted at the top of the Nemanjić family tree. Therefore, the new Serbian genealogical picture reflected much more clearly than its predecessor, the Byzantine teachings about power, which blended the 'dynastic principle' with dogma regarding the providential election of the ruler. In later monuments, where a composite family tree was depicted, linking the Nemanjić dynasty to the Byzantine and the Bulgarian royal families (Mateič, and perhaps even Studenica, the concept of the 'new Israel' was redefined in Serbian imperial ideology, according to the

  13. Characterizing local variability in long‐period horizontal tilt noise

    Science.gov (United States)

    Rohde, M.D.; Ringler, Adam; Hutt, Charles R.; Wilson, David; Holland, Austin; Sandoval, L.D; Storm, Tyler

    2017-01-01

    Horizontal seismic data are dominated by atmospherically induced tilt noise at long periods (i.e., 30 s and greater). Tilt noise limits our ability to use horizontal data for sensitive seismological studies such as observing free earth modes. To better understand the local spatial variability of long‐period horizontal noise, we observe horizontal noise during quiet time periods in the Albuquerque Seismological Laboratory (ASL) underground vault using four small‐aperture array configurations. Each array comprises eight Streckeisen STS‐2 broadband seismometers. We analyze the spectral content of the data using power spectral density and magnitude‐squared coherence (γ2‐coherence). Our results show a high degree of spatial variability and frequency dependence in the long‐period horizontal wavefield. The variable nature of long‐period horizontal noise in the ASL vault suggests that it might be highly local in nature and not easily characterized by simple physical models when overall noise levels are low, making it difficult to identify locations in the vault with lower horizontal noise. This variability could be limiting our ability to apply coherence analysis for estimating horizontal sensor self‐noise and could also complicate various indirect methods for removing long‐period horizontal noise (e.g., collocated rotational sensor or microbarograph).

  14. The Impact of Horizontal Mergers on Competition: A Literature Survey

    Directory of Open Access Journals (Sweden)

    Sevilay SARICA

    2012-06-01

    Full Text Available A large number of studies have been devoted to the effects of horizontal mergers on competition. This survey intends to review some selected studies about the effects of competition on horizontal mergers with a special attention given the horizontal integration. One of the important results obtained from this literature survey is that the findings of many researches have largely been controversial due to the different approaches and the time periods used in their studies. In these studies, even though it has been proved that horizontal mergers have negative effects on competition, it is not possible to make any precise comment on the dimension of this effect.

  15. Cuttings Transport Models and Experimental Visualization of Underbalanced Horizontal Drilling

    Directory of Open Access Journals (Sweden)

    Na Wei

    2013-01-01

    Full Text Available Aerated underbalanced horizontal drilling technology has become the focus of the drilling industry at home and abroad, and one of the engineering core issues is the horizontal borehole cleaning. Therefore, calculating the minimum injection volume of gas and liquid accurately is essential for the construction in aerated underbalanced horizontal drilling. This paper establishes a physical model of carrying cuttings and borehole cleaning in wellbore of horizontal well and a critical transport mathematical model according to gas-liquid-solid flow mechanism and large plane dunes particle transport theory.

  16. Lusin approximation for horizontal curves in step 2 Carnot groups

    OpenAIRE

    Donne, Enrico Le; Speight, Gareth

    2016-01-01

    A Carnot group $\\mathbb{G}$ admits Lusin approximation for horizontal curves if for any absolutely continuous horizontal curve $\\gamma$ in $\\mathbb{G}$ and $\\varepsilon>0$, there is a $C^1$ horizontal curve $\\Gamma$ such that $\\Gamma=\\gamma$ and $\\Gamma'=\\gamma'$ outside a set of measure at most $\\varepsilon$. We verify this property for free Carnot groups of step 2 and show that it is preserved by images of Lie group homomorphisms preserving the horizontal layer. Consequently, all step 2 Car...

  17. 33 CFR 86.07 - Directional properties.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Directional properties. 86.07... properties. The sound pressure level of a directional whistle shall be not more than 4 dB below the sound pressure level specified in § 86.05 in any direction in the horizontal plane within ±45 degrees of the...

  18. Evaluation of the stress-strain state of a twisted rod made from an anisotropic material in the shear direction at creep

    Science.gov (United States)

    Banshchikova, I. A.

    2017-10-01

    Torsion of circular samples cut out in the longitudinal direction of a plate from a transversally-isotropic alloy with reduced resistance to creep in a direction at angle of 45° to the direction of the plate normal is simulated. To verify the calculations in the finite-element program, a lower and upper estimate of the torsion angle was obtained based on the principles of minimum of the total power and minimum of the additional dissipation power.

  19. Crustal Stress in the Flinders Ranges, South Australia, From Earthquake First Motion Data

    Science.gov (United States)

    Cummins, P. R.; Balfour, N.; Love, D.

    2010-12-01

    We have used data recorded by a temporary seismograph deployment to infer constraints on the state of crustal stress in the Flinders Ranges in south-central Australia. Previous stress estimates for the region have been poorly constrained due to the lack of large events and limited station coverage for focal mechanisms. New data allowed 65 events with 544 first motions to be used in a stress inversion to estimate the principal stress directions and stress ratio.While our initial inversion suggested that stress in the region was not homogeneous, we found that discarding data for events in the top 2km of the crust resulted in a well-constrained stress orientation that is consistent with the assumption of homogeneous stress throughout the Flinders Ranges. We speculate that the need to screen out shallow events may be due to the presence in the shallow crust of either: (1) small-scale velocity heterogeneity that would bias the ray parameter estimates, or (2) heterogeneity in the stress field itself, possibly due to the influence of the relatively pronounced topographic relief. The stress derived from earthquakes in the Flinders Ranges show an oblique reverse faulting stress regime, which contrasts with the pure thrust and pure strike slip regimes suggested by earlier studies. However, the roughly E-W direction of maximum horizontal compressive stress we obtain supports the conclusion of virtually all previous studies that the Flinders Ranges are undergoing E-W compression due to orogenic events at the boundaries of the Australian and Indian Plates.

  20. The blind faith deep water horizontal pipeline tie-in project

    Energy Technology Data Exchange (ETDEWEB)

    Charalambides, John Nicos [Oceaneering International, Inc., Houston, TX (United States)

    2009-12-19

    This presentation will concentrate on the design challenges, experience and learning from the SIT and offshore installation of two deepwater pipeline tie-ins using first-of-its-kind subsea technology and installation methodologies on the 'Blind Faith' project. The Blind Faith Subsea Tie-Ins join the Blind Faith oil and gas pipelines with the Canyon Chief gas pipeline and the Mountaineer oil pipeline in 5100 feet of water. Both of the Blind Faith oil and gas pipelines are terminated with conventional PLEMs providing a horizontal connector for the tie-in and a vertical connector for a future tie-in connection point. The connectors are ROV operable/installable clamp style connectors. The method of joining to the Canyon Chief oil and gas pipelines and the type of jumper employed are unique to the tie-in. An ROV operable / installable mechanical pipe end connector connects the bare ends of the Canyon Chief and Mountaineer pipelines. The mechanical pipe end connector is fitted with an integral clamp connector hub and rests on an ROV installed mud mat. After installation of the mechanical connector, metrology was performed to create a neutral state horizontal jumper for joining the mechanical connector hub and the Blind Faith PLEM. The neutral state horizontal jumper is a compliant 'Z-Bend' design. During installation the jumper was elastically pre-deformed using a bowstring system. Pre-deformation of the jumper provided installation clearances and facilitated the neutral stress state after installation. Once landed the jumper bowstring was relaxed, allowing the jumper to expand to fit between the hubs. After expansion and make-up, the clamp connectors were tightened via an ROV operated hydraulic torque wrench. A seal test verified the integrity of the connections. After installation the jumper remains in a minimal residual stress state atypical of most horizontal jumpers. The horizontal jumper was chosen over the vertical jumper because it provides a

  1. Directional dependence of binaural loudness

    DEFF Research Database (Denmark)

    Ellermeier, Wolfgang; Sivonen, Ville Pekka

    2006-01-01

    of experiments determining the effect of sound incidence angle on loudness[1,2,3,4]. The basic experiment to be reported on here was conducted in an anechoic chamber, in which loudspeakers were mounted to present sounds from a number of directions both in the horizontal, and median planes. The subject’s task...

  2. Yaw dynamics of horizontal axis wind turbines

    Energy Technology Data Exchange (ETDEWEB)

    Hansen, A.C. (Utah Univ., Salt Lake City, UT (United States))

    1992-05-01

    Designers of a horizontal axis wind turbine yaw mechanism are faced with a difficult decision. They know that if they elect to use a yaw- controlled rotor then the system will suffer increased initial cost and increased inherent maintenance and reliability problems. On the other hand, if they elect to allow the rotor to freely yaw they known they will have to account for unknown and random, though bounded, yaw rates. They will have a higher-risk design to trade-off against the potential for cost savings and reliability improvement. The risk of a yaw-free system could be minimized if methods were available for analyzing and understanding yaw behavior. The complexity of yaw behavior has, until recently, discouraged engineers from developing a complete yaw analysis method. The objectives of this work are to (1) provide a fundamental understanding of free-yaw mechanics and the design concepts most effective at eliminating yaw problems, and (2) provide tested design tools and guidelines for use by free-yaw wind systems manufacturers. The emphasis is on developing practical and sufficiently accurate design methods.

  3. Bubble growth in a narrow horizontal space

    Energy Technology Data Exchange (ETDEWEB)

    Stutz, Benoit; Goulet, Remi [CETHIL, UMR5008, CNRS, INSA-Lyon, Universite Lyon1 (France); Passos, Julio Cesar [Universidade Federal de Santa Catarina (UFSC), Florianopolis, SC (Brazil). Dept. de Engenharia Mecanica. LABSOLAR

    2009-07-01

    The purpose of this work is to develop an axis-symmetric two-phase flow model describing the growth of a single bubble squeezed between a horizontal heated upward-facing disc and an insulating surface placed parallel to the heated surface. Heat transfers at the liquid-vapour interfaces are predicted by the kinetic limit of vaporisation. The depths of the liquid films deposed on the surfaces (heated surface and confinement space) are determined using the Moriyama and Inoue correlation (1996). Transient heat transfers within the heated wall are taken into account. The model is applied to pentane bubble growth. The influence of the gap size, the initial temperature of the system, the thermal effusivity of the heated wall and the kinetic limit of vaporisation are studied. The results show that the expansion of the bubbles strongly depends on the gap size and can be affected by the effusivity of the material. Mechanical inertia effects are mainly dominant at the beginning of the bubble expansion. Pressure drop induced by viscous effects have to be taken into account for high capillary numbers. Heat transfers at the meniscus are negligible except at the early stages of the bubble growth. (author)

  4. Effects of gravity modulation on convection in a horizontal annulus

    Energy Technology Data Exchange (ETDEWEB)

    Dyko, Mark P. [Aircraft Braking Systems Corporation, Akron, Ohio (United States). Research and Technology; Vafai, Kambiz [University of California, Riverside, CA (United States). Department of Mechanical Engineering

    2007-01-15

    Convection in the annulus between two horizontal coaxial cylinders resulting from gravity modulation in a microgravity environment is investigated for the first time. The three-dimensional transient equations of fluid motion and heat transfer are solved to study the unsteady flow structures in a large-gap annulus. The gravity fluctuations are shown to induce recirculating flows that reverse direction of rotation in response to the gravitational reversals. Except for a short period of time following flow reversal, at low modulation frequencies the centers of rotation of these flows are below and above the horizontal angular plane when the acceleration acts in the upward and downward directions, respectively, whereas at high frequencies they are above and below this plane. The effects of gravity modulation on development of secondary flows that arise in narrow- and moderate-gap annuli owing to thermal instability are also investigated. It is found that supercritical transverse rolls repeatedly form, dissipate, and re-form in the upper and lower regions of a narrow-gap annulus as a result of the fluctuating gravity field. At the same frequency, the supercritical rolls in a moderate-gap annulus are much slower to develop between flow reversals. The results show that gravity modulation has a stabilizing effect on the secondary flows compared to the case of a constant gravity force, and this effect diminishes with reduction in either frequency or annulus radius ratio R. The effects of frequency on heat transfer in large-, moderate-, and narrow-gap annuli are also studied. It is found that the time-averaged Nusselt number approaches that of pure conduction at high frequencies and increases toward that for terrestrial natural convection as frequency is reduced. As R is decreased, the increase in time-averaged Nusselt number brought about by reducing frequency becomes a smaller percentage of the value for terrestrial natural convection. The results for large-, moderate

  5. Receiving beam patterns in the horizontal plane of a harbor porpoise (Phocoena phocoena)

    Science.gov (United States)

    Kastelein, Ronald A.; Janssen, Mirjam; Verboom, Willem C.; de Haan, Dick

    2005-08-01

    Receiving beam patterns of a harbor porpoise were measured in the horizontal plane, using narrow-band frequency modulated signals with center frequencies of 16, 64, and 100 kHz. Total signal duration was 1000 ms, including a 200 ms rise time and 300 ms fall time. The harbor porpoise was trained to participate in a psychophysical test and stationed itself horizontally in a specific direction in the center of a 16-m-diameter circle consisting of 16 equally-spaced underwater transducers. The animal's head and the transducers were in the same horizontal plane, 1.5 m below the water surface. The go/no-go response paradigm was used; the animal left the listening station when it heard a sound signal. The method of constants was applied. For each transducer the 50% detection threshold amplitude was determined in 16 trials per amplitude, for each of the three frequencies. The beam patterns were not symmetrical with respect to the midline of the animal's body, but had a deflection of 3-7° to the right. The receiving beam pattern narrowed with increasing frequency. Assuming that the pattern is rotation-symmetrical according to an average of the horizontal beam pattern halves, the receiving directivity indices are 4.3 at 16 kHz, 6.0 at 64 kHz, and 11.7 dB at 100 kHz. The receiving directivity indices of the porpoise were lower than those measured for bottlenose dolphins. This means that harbor porpoises have wider receiving beam patterns than bottlenose dolphins for the same frequencies. Directivity of hearing improves the signal-to-noise ratio and thus is a tool for a better detection of certain signals in a given ambient noise condition.

  6. Short-radius horizontal well re-entry learning curve: prize, cost and operational experience

    Energy Technology Data Exchange (ETDEWEB)

    Boote, K. [Ocelot Energy Inc., Calgary, AB (Canada); MacDonald, R. [Lauron Engineering Ltd, Calgary, AB (Canada)

    1997-12-01

    Six mature vertical wells in Alberta belonging to Ocelot Energy Inc., were reentered and drilled horizontally. Experiences gained, the modifications made to the drilling program and the rewards in the form of incremental oil, were discussed. Details of pre- and post-performance, operational experiences with exiting the casing, building the curve, overbalance versus underbalanced drilling, motors, directional equipment, setting liners, remedial workovers and the cost of the operation were part of the discussion.

  7. Exploration of Horizontal Information Transmission through Social Learning in Juvenile Atlantic Spotted Dolphins (Stenella frontalis

    Directory of Open Access Journals (Sweden)

    Gaïane L. B. De Brabanter

    2017-11-01

    Full Text Available Although vertical (mother-to-offspring information transfer has been reported in dolphins, it is unclear whether horizontal information transfer takes place between peers of non-parental individuals. We hypothesized that horizontal information transmission takes place within juvenile social play-forage subgroups and within pairs of juveniles in the form of social learning, as a way for older juveniles to contribute to the further development of younger juveniles’ foraging skills. Since 1985, a long-term study in the Bahamas has involved the collection of underwater videos and sound recordings on the social structure of a resident community of free-ranging Atlantic spotted dolphins Stenella frontalis. Foraging behaviors of juvenile dolphins were analyzed in 24 independent foraging events recorded on video from 1994 to 2013. Forty-nine juveniles in total were observed, including eight individually identified juveniles foraging alone, eight individually identified juveniles foraging in pairs, and 33 juveniles foraging in eight subgroups of three or more dolphins. The comparison of older juveniles' behavior against younger juveniles' behavior in juvenile play-forage subgroups suggested the potential for horizontal transmission of information about prey location. However, we found no direct evidence for social learning or of teaching in pairs. This new information about wild Atlantic spotted dolphin social structure is a starting point in horizontal information transmission research and is important in terms of cognitive processes and welfare implications.

  8. Staged fracturing of horizontal shale gas wells with temporary plugging by sand filling

    Directory of Open Access Journals (Sweden)

    Xing Liang

    2017-03-01

    Full Text Available Due to downhole complexities, shale-gas horizontal well fracturing in the Sichuan Basin suffered from casing deformation and failure to apply the technique of cable-conveyed perforation bridge plug. In view of these problems, a new technique of staged volume fracturing with temporary plugging by sand filling is employed. Based on theoretical analyses and field tests, a design of optimized parameters of coiled tubing-conveyed multi-cluster sand-blasting perforation and temporary plugging by sand filling was proposed. It was applied in the horizontal Well ZJ-1 in which casing deformation occurred. The following results are achieved in field operations. First, this technique enables selective staged fracturing in horizontal sections. Second, this technique can realize massive staged fracturing credibly without mechanical plugging, with the operating efficiency equivalent to the conventional bridge plug staged fracturing. Third, full-hole is preserved after fracturing, thus it is possible to directly conduct an open flow test without time consumption of a wiper trip. The staged volume fracturing with temporary plugging by sand filling facilitated the 14-stage fracturing in Well ZJ-1, with similar SRV to that achieved by conventional bridge plug staged fracturing and higher gas yield than neighboring wells on the same well pad. Thus, a new and effective technique is presented in multi-cluster staged volume fracturing of shale gas horizontal wells.

  9. Guided Growth of Horizontal p-Type ZnTe Nanowires.

    Science.gov (United States)

    Reut, Gilad; Oksenberg, Eitan; Popovitz-Biro, Ronit; Rechav, Katya; Joselevich, Ernesto

    2016-08-04

    A major challenge toward large-scale integration of nanowires is the control over their alignment and position. A possible solution to this challenge is the guided growth process, which enables the synthesis of well-aligned horizontal nanowires that grow according to specific epitaxial or graphoepitaxial relations with the substrate. However, the guided growth of horizontal nanowires was demonstrated for a limited number of materials, most of which exhibit unintentional n-type behavior. Here we demonstrate the vapor-liquid-solid growth of guided horizontal ZnTe nanowires and nanowalls displaying p-type behavior on four different planes of sapphire. The growth directions of the nanowires are determined by epitaxial relations between the nanowires and the substrate or by a graphoepitaxial effect that guides their growth along nanogrooves or nanosteps along the surface. We characterized the crystallographic orientations and elemental composition of the nanowires using transmission electron microscopy and photoluminescence. The optoelectronic and electronic properties of the nanowires were studied by fabricating photodetectors and top-gate thin film transistors. These measurements showed that the guided ZnTe nanowires are p-type semiconductors and are photoconductive in the visible range. The guided growth of horizontal p-type nanowires opens up the possibility of parallel nanowire integration into functional systems with a variety of potential applications not available by other means.

  10. Inclinometer Assembly Error Calibration and Horizontal Image Correction in Photoelectric Measurement Systems

    Directory of Open Access Journals (Sweden)

    Xiaofang Kong

    2018-01-01

    Full Text Available Inclinometer assembly error is one of the key factors affecting the measurement accuracy of photoelectric measurement systems. In order to solve the problem of the lack of complete attitude information in the measurement system, this paper proposes a new inclinometer assembly error calibration and horizontal image correction method utilizing plumb lines in the scenario. Based on the principle that the plumb line in the scenario should be a vertical line on the image plane when the camera is placed horizontally in the photoelectric system, the direction cosine matrix between the geodetic coordinate system and the inclinometer coordinate system is calculated firstly by three-dimensional coordinate transformation. Then, the homography matrix required for horizontal image correction is obtained, along with the constraint equation satisfying the inclinometer-camera system requirements. Finally, the assembly error of the inclinometer is calibrated by the optimization function. Experimental results show that the inclinometer assembly error can be calibrated only by using the inclination angle information in conjunction with plumb lines in the scenario. Perturbation simulation and practical experiments using MATLAB indicate the feasibility of the proposed method. The inclined image can be horizontally corrected by the homography matrix obtained during the calculation of the inclinometer assembly error, as well.

  11. Towards a new natural theology based on horizontal transcendence ...

    African Journals Online (AJOL)

    As a result the article rejects absolute transcendence, replacing it with a horizontal transcendence that accords with humans' biological makeup and with presentday scientifi c thinking. In the framework of horizontal transcendence the pivotal problem of the human condition is no longer death, but life. This has radical ...

  12. The Interplay of Different Types of Governance in Horizontal Cooperations

    DEFF Research Database (Denmark)

    Raue, Jan Simon; Wieland, Andreas

    2015-01-01

    Purpose – Over the last decades, horizontal cooperations between logistics service providers (LSPs) have become a well-established organizational form and their use is expected to grow even further in the future. In spite of this increasing importance of horizontal LSP cooperations, little research...

  13. Horizontal cooperation in transport and logistics : A literature review

    NARCIS (Netherlands)

    Cruijssen, Frans; Dullaert, Wout; Fleuren, Hein

    This article presents a broad review of horizontal cooperation in transport and logistics. This topic is fast gaining momentum in the logistics sector and is thus highly relevant from a practical point of view. Moreover, horizontal cooperation is also interesting from a theoretical perspective

  14. Horizontal Cooperation in Transport and Logistics: A Literature Review

    NARCIS (Netherlands)

    Cruijssen, Frans; Dullaert, Wout; Fleuren, Hein

    2007-01-01

    This article presents a broad review of horizontal cooperation in transport and logistics. This topic is fast gaining momentum in the logistics sector and is thus highly relevant from a practical point of view. Moreover, horizontal cooperation is also interesting from a theoretical perspective

  15. District Power Equalization, Horizontal Equity and the Property Mix.

    Science.gov (United States)

    Hilley, John

    1980-01-01

    Argues that the traditional district power equalization (DPE) grant formula achieves horizontal equity, that the formula must be modified when the measure of fiscal capacity differs from the legal tax base, and that the inclusion of a tax exporting variable leads to the breakdown of horizontal equity. (Author/IRT)

  16. Processing woody biomass with a modified horizontal grinder

    Science.gov (United States)

    Dana Mitchell; John Klepac

    2008-01-01

    This study documents the production rate and cost of producing woody biomass chips for use in a power plant. The power plant has specific raw material handling requirements. Output from a 3-knife chipper, a tub grinder, and a horizontal grinder was considered. None of the samples from these machines met the specifications needed. A horizontal grinder was modified to...

  17. Investigation of blade performance of horizontal axis wind turbine ...

    African Journals Online (AJOL)

    The shape of rotor blade plays an important role in determining the overall aerodynamic performance of a horizontal axis wind turbine. In this work, blade is designed for a 5KW horizontal axis wind turbine which is already in market. For designing blade, blade element momentum theory (BEMT) is used and a computer ...

  18. Artificial remisión de V. horizonte artificial.

    OpenAIRE

    2011-01-01

    [ES] Definición del término Artificial remisión de V. horizonte artificial. en el diccionario Dicter. [EN] Definition of the word Artificial remisión de V. horizonte artificial. in the dictionary Dicter.

  19. Wheel running alters patterns of uncontrollable stress-induced cfos mRNA expression in rat dorsal striatum direct and indirect pathways: a possible role for plasticity in adenosine receptors

    Science.gov (United States)

    Clark, Peter J.; Ghasem, Parsa R.; Mika, Agnieszka; Day, Heidi E.; Herrera, Jonathan J.; Greenwood, Benjamin N.; Fleshner, Monika

    2014-01-01

    Emerging evidence indicates that adenosine is a major regulator of striatum activity, in part, through the antagonistic modulation of dopaminergic function. Exercise can influence adenosine and dopamine activity, which may subsequently promote plasticity in striatum adenosine and dopamine systems. Such changes could alter activity of medium spiny neurons and impact striatum function. The purpose of this study was two-fold. The first was to characterize the effect of long-term wheel running on adenosine 1 (A1R), adenosine 2A (A2AR), dopamine 1 (D1R), and dopamine 2 (D2R) receptor mRNA expression in adult rat dorsal and ventral striatum structures using in situ hybridization. The second was to determine if changes to adenosine and dopamine receptor mRNA from running are associated with altered cfos mRNA induction in dynorphin- (direct pathway) and enkephalin- (indirect pathway) expressing neurons of the dorsal striatum following stress exposure. We report that chronic running, as well as acute uncontrollable stress, reduced A1R and A2AR mRNA levels in the dorsal and ventral striatum. Running also modestly elevated D2R mRNA levels in striatum regions. Finally, stress-induced cfos was potentiated in dynorphin and attenuated in enkephalin expressing neurons of running rats. These data suggest striatum adenosine and dopamine systems are targets for neuroplasticity from exercise, which may contribute to changes in direct and indirect pathway activity. These findings may have implications for striatum mediated motor and cognitive processes, as well as exercise facilitated stress-resistance. PMID:25017571

  20. Stress Reduction, Bacterial Style.

    Science.gov (United States)

    Gottesman, Susan

    2017-10-15

    Bacteria have robust responses to a variety of stresses. In particular, bacteria like Escherichia coli have multiple cell envelope stress responses, and generally we evaluate what these responses are doing by the repair systems they induce. However, probably at least as important in interpreting what is being sensed as stress are the genes that these stress systems downregulate, directly or indirectly. This is discussed here for the Cpx and sigma E systems of E. coli. Copyright © 2017 American Society for Microbiology.

  1. Dynamic Response in Transient Stress-Field Behavior Induced by Hydraulic Fracturing

    Science.gov (United States)

    Jenkins, Andrew

    Hydraulic fracturing is a technique which is used to exploit geologic features and subsurface properties in an effort to increase production in low-permeability formations. The process of hydraulic fracturing provides a greater surface contact area between the producing formation and the wellbore and thus increases the amount of recoverable hydrocarbons from within the reservoir. The use of this stimulation technique has brought on massive applause from the industry due to its widespread success and effectiveness, however the dynamic processes that take part in the development of hydraulic fractures is a relatively new area of research with respect to the massive scale operations that are seen today. The process of hydraulic fracturing relies upon understanding and exploiting the in-situ stress distribution throughout the area of study. These in-situ stress conditions are responsible for directing fracture orientation and propagation paths throughout the period of injection. The relative magnitude of these principle stresses is key in developing a successful stimulation plan. In horizontal well plan development the interpretation of stress within the reservoir is required for determining the azimuth of the horizontal well path. These horizontal laterals are typically oriented in a manner such that the well path lies parallel to the minimum horizontal stress. This allows for vertical fractures to develop transversely to the wellbore, or normal to the least principle stress without the theoretical possibility of fractures overlapping, creating the most efficient use of the fluid energy during injection. The orientation and magnitude of these in-situ stress fields however can be dynamic, controlled by the subsequent fracture propagation and redistribution of the surrounding stresses. That is, that as the fracture propagates throughout the reservoir, the relative stress fields surrounding the fractures may see a shift and deviate from their original direction or

  2. Horizontal Gene Transfer of Functional Type VI Killing Genes by Natural Transformation.

    Science.gov (United States)

    Thomas, Jacob; Watve, Samit S; Ratcliff, William C; Hammer, Brian K

    2017-07-25

    Horizontal gene transfer (HGT) can have profound effects on bacterial evolution by allowing individuals to rapidly acquire adaptive traits that shape their strategies for competition. One strategy for intermicrobial antagonism often used by Proteobacteria is the genetically encoded contact-dependent type VI secretion system (T6SS), a weapon used to kill heteroclonal neighbors by direct injection of toxic effectors. Here, we experimentally demonstrate that Vibrio cholerae can acquire new T6SS effector genes via horizontal transfer and utilize them to kill neighboring cells. Replacement of one or more parental alleles with novel effectors allows the recombinant strain to dramatically outcompete its parent. Using spatially explicit modeling, we examine how this process could affect the ecology and evolution of surface-attached microbial populations. HGT of T6SS effector-immunity pairs is risky: transformation brings a cell into conflict with its former clone mates but can be adaptive when superior T6SS alleles are acquired. More generally, we find that these costs and benefits are not symmetric and that high rates of HGT can act as a hedge against competitors with unpredictable T6SS efficacy. We conclude that antagonism and horizontal transfer drive successive rounds of weapon optimization and selective sweeps, dynamically shaping the composition of microbial communities. IMPORTANCE The contact-dependent type VI secretion system (T6SS) is frequently used by Proteobacteria to kill adjacent competitors. While DNA released by T6 killing can be horizontally acquired, it remains untested whether T6 genes themselves can be horizontally acquired and then utilized to compete with neighboring cells. Using naturally transformable Vibrio cholerae , we provide the first direct empirical support for the hypothesis that T6 genes are exchanged horizontally (e.g., from dead competitors) and functionally deployed to compete with neighboring cells. Using computational simulations, we

  3. Results from the first ARM diffuse horizontal shortwave irradiance comparison

    Energy Technology Data Exchange (ETDEWEB)

    Michalsky, J J.(New York, State Univ Of); Dolce, R (Zipp and Zonen, Inc.); Dutton, E. G.(NOAA/CMDL); Haeffelin, Martial (VISITORS); Major, G (Budabest University of Economic Sciences); Schlemmer, J A.; Slater, Donald W.(BATTELLE (PACIFIC NW LAB)); Hickey, J R.(The Eppley Laboratory, Inc.); Jeffries, W Q.(Yankee Environmental Systems); Los, A (Kipp and Zonen, Inc.); Mathias, D (Carter-Scott Design); McArthur, LJ B.(Meteorlogical Service of Canada); Philipona, R (Physikalish - Meteorologiisches Observatorium and World); Reda, I (National Renewable Energy Laboratory); Stoffel, T (National Renewable Energy Laboratory)

    2003-02-07

    The first intensive observation period (IOP) dedicated exclusively to the measurement of diffuse horizontal shortwave irradiance was held in the Fall 2001 at the central facility of the Atmospheric Radiation Measurement (ARM) Southern Great Plains (SGP) site with the cooperation of the Baseline Surface Radiation Network (BSRN) community. Fourteen simultaneous measurements were obtained over a two-week period under mostly clear skies with low to moderate aerosol loading. Overcast data were obtained during the morning of one day. The purpose of the comparison was to assess the level of agreement in diffuse irradiance measurements among most commercial pyranometers and a few prototypes calibrated independently using current practices. The hope was to achieve a consensus for this measurement with the goal of improving the uncertainty of shortwave diffuse irradiance measurements. All diffuse broadband measurements were made using the same type of two-axis tracker with the direct beam blocked by shading balls. Tracking was very good during the IOP with no outages associated with tracker problems. Five of the measurements are reproducible to about 2 W/m2 at the 95% confidence level. Four more agree with the most consistent group to about 4 W/m2 at the 95% confidence level after correction for thermal offsets. The prototypes agree less well with the most consistent group.

  4. Effects of Horizontal Acceleration on Human Visual Acuity and Stereopsis

    Science.gov (United States)

    Horng, Chi-Ting; Hsieh, Yih-Shou; Tsai, Ming-Ling; Chang, Wei-Kang; Yang, Tzu-Hung; Yauan, Chien-Han; Wang, Chih-Hung; Kuo, Wu-Hsien; Wu, Yi-Chang

    2015-01-01

    The effect of horizontal acceleration on human visual acuity and stereopsis is demonstrated in this study. Twenty participants (mean age 22.6 years) were enrolled in the experiment. Acceleration from two different directions was performed at the Taiwan High-Speed Rail Laboratory. Gx and Gy (0.1 g) were produced on an accelerating platform where the subjects stood. The visual acuity and stereopsis of the right eye were measured before and during the acceleration. Acceleration stereopsis. Vision decreased (mean from 0.02 logMAR to 0.25 logMAR) and stereopsis declined significantly (mean from 40 s to 60.2 s of arc) when Gx > 0.1 g. Visual acuity worsened (mean from 0.02 logMAR to 0.19 logMAR) and poor stereopsis was noted (mean from 40 s to 50.2 s of arc) when Gy > 0.1 g. The effect of acceleration from the X-axis on the visual system was higher than that from the Y-axis. During acceleration, most subjects complained of ocular strain when reading. To our knowledge, this study is the first to report the exact levels of visual function loss during Gx and Gy. PMID:25607601

  5. Lidar-Observed Stress Vectors and Veer in the Atmospheric Boundary Layer

    DEFF Research Database (Denmark)

    Berg, Jacob; Mann, Jakob; Patton, Edward G.

    2013-01-01

    This study demonstrates that a pulsed wind lidar is a reliable instrument for measuring angles between horizontal vectors of significance in the atmospheric boundary layer. Three different angles are considered: the wind turning, the angle between the stress vector and the mean wind direction......, and the angle between the stress vector and the vertical gradient of the mean velocity vector. The latter is assumed to be zero by the often applied turbulent-viscosity hypothesis, so that the stress vector can be described through the vertical gradient of velocity. In the atmospheric surface layer, where...... the Coriolis force is negligible, this is supposedly a good approximation. High-resolution large-eddy simulation data show that this is indeed the case even beyond the surface layer. In contrast, through analysis of WindCube lidar measurements supported by sonic measurements, the study shows that it is only...

  6. Horizontal oil well applications and oil recovery assessment. Volume 1: Success of horizontal well technology, Final report

    Energy Technology Data Exchange (ETDEWEB)

    Deskins, W.G.; McDonald, W.J.; Knoll, R.G.; Springer, S.J.

    1995-03-01

    Horizontal technology has been applied in over 110 formations in the USA. Volume I of this study addresses the overall success of horizontal technology, especially in less-publicized formations, i.e., other than the Austin Chalk, Bakken, and Niobrara. Operators in the USA. and Canada were surveyed on a formation-by-formation basis by means of a questionnaire. Response data were received describing horizontal well projects in 58 formations in the USA. and 88 in Canada. Operators responses were analyzed for trends in technical and economic success based on lithology (clastics and carbonates) and resource type (light oil, heavy oil, and gas). The potential impact of horizontal technology on reserves was also estimated. A forecast of horizontal drilling activity over the next decade was developed.

  7. Fracture analysis and determination of in-situ stress direction from resistivity and acoustic image logs and core data in the Wenchuan Earthquake Fault Scientific Drilling Borehole-2 (50-1370 m)

    Science.gov (United States)

    Nie, Xin; Zou, Changchun; Pan, Li; Huang, Zhaohui; Liu, Dongming

    2013-05-01

    After the Wenchuan Earthquake on May 12th, 2008, the Wenchuan Earthquake Fault Scientific Drilling Project (WFSD) was initiated in order to investigate the structure of the fault zones and the mechanism of the earthquake. The WFSD contains four boreholes (WFSD-1, WFSD-2, WFSD-3 and WFSD-4) lying at the maximum displacement locations along the Yingxiu-Beichuan fault zone and the Guanxian-Anxian fault zone, and WFSD-2 is the second borehole and is still being drilled. Core samples, resistivity and acoustic image logging data were acquired from 50 to 1370 m. The natural fractures, borehole breakouts, drilling-induced fractures and drilling-enhanced natural fractures were identified from the cores and the image logs and were statistically analyzed. The strikes of the natural fractures systematically vary and can be sorted into four groups according to depth: (1) above 637 m, mainly striking ENE-WSW; (2) in the interval of 637-932.6 m, striking NNE-SSW; (3) in the interval of 932.6-1200 m, directed ENE-WSW then to WNW-ESE, while striking NE-SW from 1030 m to 1150 m; (4) from 1200 m to 1370 m, maintaining a strike of WNW-ESE. The natural fractures from 50 m to 637 m seem to be reverse faults which strike approximately parallelly to the main fault. Two sets of conjugate fractures around 1002.4 m indicating subvertical maximum principal paleo-stress direction may be a subordinate structure of the main fault caused by a local stress field, and it reveals the complex stress field of Yingxiu-Beichuan fault zone when the fractures formed. A total of 12 BOs, 2 sets of DIFs and one set of DEFs with an overall length of 30.4 m were interpreted from 960 m to 1370 m in WFSD-2. The average SHmax orientation interpreted for WFSD-2 (960-1370 m) is 120.7°-300.7°N (i.e. WNW-ESE) with the standard deviation of 9.2° and it is consistent with the stress status of Yingxiu-Beichuan fault zone which is one of the main fault zones in the 2008 Wenchuan Earthquake. Well logging data and

  8. Stress evolution and fault stability during the Weichselian glacial cycle

    Energy Technology Data Exchange (ETDEWEB)

    Lund, Bjoern; Schmidt, Peter; Hieronymus, Christoph (Dept. of Earth Sciences, Uppsala Univ., Uppsala (Sweden))

    2009-10-15

    layered models tend to fit the data better than the few models with laterally varying lithosphere thickness, where especially the horizontal velocities vary significantly between models and between the models and the data. The regional patterns of stress distribution and stress directions are remarkably similar for all earth models, while the magnitude of the induced stresses vary significantly between models, mainly due to variations in the stiffness of the uppermost layer. The temporal stress evolution at 500 m depth in Forsmark and Oskarshamn is determined by the ice sheet evolution whereas the magnitude of the induced stresses depend on the earth model. For models with realistic stiffness distributions, the induced horizontal stresses both in Forsmark and in Oskarshamn are similar to the magnitude of the vertical stress of the ice load. Stress histories for the Paervie fault, which is located close to the western edge of the ice sheet, show that although the Paervie fault is the largest known endglacial fault, the induced stress magnitudes are not very high, which is due to the relatively modest thickness of the ice sheet here all through the glacial history. In the fault stability analysis we use mainly two synthetic background stress fields, one reverse and one strike-slip. In agreement with previous studies we find that the background stress field is important for the resulting stability field. We show that in a reverse state of stress at 9.5 km depth, with a glacially induced pore pressure head of 50% of the local ice weight, both Forsmark and Oskarshamn would experience fault instability at the end of glaciation. In a strike-slip stress state, the stability field is more sensitive to variations in the direction of the background field, but for our reference field both Forsmark and Oskarshamn show mostly stable conditions. Stability analysis at the Paervie fault shows that in a strike-slip background field the Paervie fault would be stable all through the

  9. Effect of direct current sputtering power on the behavior of amorphous indium-gallium-zinc-oxide thin-film transistors under negative bias illumination stress: A combination of experimental analyses and device simulation

    Energy Technology Data Exchange (ETDEWEB)

    Jang, Jun Tae; Kim, Dong Myong; Choi, Sung-Jin; Kim, Dae Hwan, E-mail: khs3297@cnu.ac.kr, E-mail: drlife@kookmin.ac.kr [School of Electrical Engineering, Kookmin University, Seoul 136-702 (Korea, Republic of); Park, Jozeph [Department of Materials Science and Engineering, KAIST, Daejeon 305-701 (Korea, Republic of); Ahn, Byung Du [School of Electrical and Electronic Engineering, Yonsei University, Seodaemun-gu, Seoul 120-749 (Korea, Republic of); Kim, Hyun-Suk, E-mail: khs3297@cnu.ac.kr, E-mail: drlife@kookmin.ac.kr [Department of Materials Science and Engineering, Chungnam National University, Daejeon 305-764 (Korea, Republic of)

    2015-03-23

    The effect of direct current sputtering power of indium-gallium-zinc-oxide (IGZO) on the performance and stability of the corresponding thin-film transistor devices was studied. The field effect mobility increases as the IGZO sputter power increases, at the expense of device reliability under negative bias illumination stress (NBIS). Device simulation based on the extracted sub-gap density of states indicates that the field effect mobility is improved as a result of the number of acceptor-like states decreasing. The degradation by NBIS is suggested to be induced by the formation of peroxides in IGZO rather than charge trapping.

  10. A comparative analysis of vertical and horizontal fixation disparity in sentence reading.

    Science.gov (United States)

    Jainta, S; Blythe, H I; Nikolova, M; Jones, M O; Liversedge, S P

    2015-05-01

    Humans have two, frontally placed eyes and during reading oculomotor and sensory processes are needed to combine the two inputs into a unified percept of the text. Generally, slight vergence errors, i.e., fixation disparities, occur but do not cause double vision since disparate retinal inputs fall into Panum's fusional area, that is, a range of disparity wherein sensory fusion of the two retinal images is achieved. In this study, we report benchmark data with respect to the mean magnitude and range of vertical compared to horizontal fixation disparities for natural reading. Our data clearly fit to an elliptical pattern of Panum's fusional area that corresponds with theoretical estimates. Furthermore, when we examined disparity-driven vergence adjustments during fixations by comparing monocular with binocular reading conditions, we found that only horizontal fixation disparities increased significantly under conditions of monocular stimulation. Also, no significant vertical fine-tuning (vergence adjustment) was observed for vergence eye movements during reading fixations. Thus, horizontal and vertical fixation disparities and vergence adjustments during reading showed quite different characteristics, and this dissociation is directly related to the functional role of vergence adjustments: vertical fusion - and vertical vergence - subserve the maintenance of a single percept and stereopsis by keeping the eyes in register and allowing for horizontal fusional processes to successfully operate over a vertically aligned input. A reliable and stable vertical alignment is, thus, a pre-requisite over which horizontal fusional responses (and depth perception) can work most efficiently - even in a task like reading. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. Stress estimation around the survey wells in Hanshin-Awaji area by means of AE/DR and DSCA experiments; AE/DR ho to DSCA ho ni yoru Hanshin Awaji chiiki chosa kui shuhen no chikaku oryoku sokutei

    Energy Technology Data Exchange (ETDEWEB)

    Ito, H.; Kuwahara, Y.; Nishizawa, O. [Geological Survey of Japan, Tsukuba (Japan); Yamamoto, K. [Tohoku University, Sendai (Japan). Faculty of Science; Sano, O. [Yamaguchi University, Yamaguchi (Japan). Faculty of Engineering; Yokoyama, T.; Kudo, R. [OYO Corp., Tokyo (Japan); Xue, Z. [Kiso-Jiban Consultants Co. Ltd., Tokyo (Japan)

    1996-05-01

    A total of 5 wells were excavated in the Hanshin-Awaji area (Ikeda, Takarazuka, Tarumi, Hirabayashi and Ikunami) to collect the core samples, which were analyzed by the AE/DR and DSCA methods to determine crustal stresses. For the AE/DR analysis, the core sample was cut in the vertical direction, and in the horizontal direction at intervals of 45{degree}. The sample of unknown orientation was provided with a datum line common for both methods, to compare the results by these methods. A load was applied to the sample, provided with an AE sensor and strain gauge on the sides, in the longitudinal direction. For the DSCA analysis, the core sample was cut into a cube having a side length of 33mm, with a pair of planes directed in parallel to the datum line. A total of 18 strain gauges, 10mm in gauge length, were attached to the cube. The AE/DR analysis gave the maximum and minimum principal stresses in the horizontal plane and stresses in the vertical direction, whereas the DSCA the maximum, intermediate and minimum principal stresses. 3 refs., 7 figs.

  12. Horizontal gene acquisitions by eukaryotes as drivers of adaptive evolution.

    Science.gov (United States)

    Schönknecht, Gerald; Weber, Andreas P M; Lercher, Martin J

    2014-01-01

    In contrast to vertical gene transfer from parent to offspring, horizontal (or lateral) gene transfer moves genetic information between different species. Bacteria and archaea often adapt through horizontal gene transfer. Recent analyses indicate that eukaryotic genomes, too, have acquired numerous genes via horizontal transfer from prokaryotes and other lineages. Based on this we raise the hypothesis that horizontally acquired genes may have contributed more to adaptive evolution of eukaryotes than previously assumed. Current candidate sets of horizontally acquired eukaryotic genes may just be the tip of an iceberg. We have recently shown that adaptation of the thermoacidophilic red alga Galdieria sulphuraria to its hot, acid, toxic-metal laden, volcanic environment was facilitated by the acquisition of numerous genes from extremophile bacteria and archaea. Other recently published examples of horizontal acquisitions involved in adaptation include ice-binding proteins in marine algae, enzymes for carotenoid biosynthesis in aphids, and genes involved in fungal metabolism. Editor's suggested further reading in BioEssays Jumping the fine LINE between species: Horizontal transfer of transposable elements in animals catalyses genome evolution Abstract. © 2014 WILEY Periodicals, Inc.

  13. The scale and evolutionary significance of horizontal gene transfer in the choanoflagellate Monosiga brevicollis.

    Science.gov (United States)

    Yue, Jipei; Sun, Guiling; Hu, Xiangyang; Huang, Jinling

    2013-10-25

    It is generally agreed that horizontal gene transfer (HGT) is common in phagotrophic protists. However, the overall scale of HGT and the cumulative impact of acquired genes on the evolution of these organisms remain largely unknown. Choanoflagellates are phagotrophs and the closest living relatives of animals. In this study, we performed phylogenomic analyses to investigate the scale of HGT and the evolutionary importance of horizontally acquired genes in the choanoflagellate Monosiga brevicollis. Our analyses identified 405 genes that are likely derived from algae and prokaryotes, accounting for approximately 4.4% of the Monosiga nuclear genome. Many of the horizontally acquired genes identified in Monosiga were probably acquired from food sources, rather than by endosymbiotic gene transfer (EGT) from obsolete endosymbionts or plastids. Of 193 genes identified in our analyses with functional information, 84 (43.5%) are involved in carbohydrate or amino acid metabolism, and 45 (23.3%) are transporters and/or involved in response to oxidative, osmotic, antibiotic, or heavy metal stresses. Some identified genes may also participate in biosynthesis of important metabolites such as vitamins C and K12, porphyrins and phospholipids. Our results suggest that HGT is frequent in Monosiga brevicollis and might have contributed substantially to its adaptation and evolution. This finding also highlights the importance of HGT in the genome and organismal evolution of phagotrophic eukaryotes.

  14. Complexity of genetic sequences modified by horizontal gene transfer and degraded-DNA uptake

    Science.gov (United States)

    Tremberger, George; Dehipawala, S.; Nguyen, A.; Cheung, E.; Sullivan, R.; Holden, T.; Lieberman, D.; Cheung, T.

    2015-09-01

    Horizontal gene transfer has been a major vehicle for efficient transfer of genetic materials among living species and could be one of the sources for noncoding DNA incorporation into a genome. Our previous study of lnc- RNA sequence complexity in terms of fractal dimension and information entropy shows a tight regulation among the studied genes in numerous diseases. The role of sequence complexity in horizontal transferred genes was investigated with Mealybug in symbiotic relation with a 139K genome microbe and Deinococcus radiodurans as examples. The fractal dimension and entropy showed correlation R-sq of 0.82 (N = 6) for the studied Deinococcus radiodurans sequences. For comparison the Deinococcus radiodurans oxidative stress tolerant catalase and superoxide dismutase genes under extracellular dGMP growth condition showed R-sq ~ 0.42 (N = 6); and the studied arsenate reductase horizontal transferred genes for toxicity survival in several microorganisms showed no correlation. Simulation results showed that R-sq transferred genes in Mealybug. The mild correlation of R-sq ~ 0.5 for fractal dimension versus transcription level in the studied Deinococcus radiodurans sequences upon extracellular dGMP growth condition would suggest that lower fractal dimension with less electron density fluctuation favors higher transcription level.

  15. Increasing the repeating units of ethylene glycol-based dimethacrylates directed toward reduced oxidative stress and co-stimulatory factors expression in human monocytic cells.

    Science.gov (United States)

    Tamura, Atsushi; Fukumoto, Izumi; Yui, Nobuhiko; Matsumura, Mitsuaki; Miura, Hiroyuki

    2015-03-01

    The ethylene glycol-based dimethacrylates are commonly used in biomaterials and dental restorative materials as a cross-linking agent. In this study, toxic effect of triethylene glycol dimethacrylate (TEGDMA) and poly(ethylene glycol) dimethacrylates (PEG-DMAs) with various ethylene glycol repeating units was investigated in terms of cytotoxicity, oxidative stress, and the expression of co-stimulatory factors in human leukemia cell line (THP-1 cells) to verify the effect of ethylene glycol repeating units. Note that the 1-octanol/water partition coefficient of PEG-based dimethacrylates decreased with increasing the ethylene glycol repeating units, indicating that the hydrophilicity of PEG-DMAs increased with ethylene glycol repeating units. The toxic effect of PEG-DMAs such as cytotoxicity, oxidative stress, and the expression of CD86 in treated THP-1 cells are reduced with increasing the ethylene glycol repeating units in PEG-DMAs. However, the expression of CD54 in treated THP-1 cells was not influenced with the ethylene glycol repeating units and the maximal expression level of CD54 was observed at the concentration range of 2-4 mM for all samples. Accordingly, hydrophilic character of PEG-DMAs with long ethylene glycol chains definitely alleviates the some toxic aspect of PEG-based DMAs. This finding would provide important insight into the design of new biomaterials and dental materials with superior biocompatibility. © 2014 Wiley Periodicals, Inc.

  16. Horizontal Transfer and the Evolution of Host-Pathogen Interactions

    Science.gov (United States)

    de la Casa-Esperón, Elena

    2012-01-01

    Horizontal gene transfer has been long known in viruses and prokaryotes, but its importance in eukaryotes has been only acknowledged recently. Close contact between organisms, as it occurs between pathogens and their hosts, facilitates the occurrence of DNA transfer events. Once inserted in a foreign genome, DNA sequences have sometimes been coopted by pathogens to improve their survival or infectivity, or by hosts to protect themselves against the harm of pathogens. Hence, horizontal transfer constitutes a source of novel sequences that can be adopted to change the host-pathogen interactions. Therefore, horizontal transfer can have an important impact on the coevolution of pathogens and their hosts. PMID:23227424

  17. Capillary-contacting horizontal cells in the rodent retina.

    Science.gov (United States)

    Mojumder, Deb Kumar

    2008-06-01

    Horizontal cells, the interneurons in the distal retina, provide feedback control of the photoreceptor synaptic output at the first synapse in the visual pathway. This article, using immunohistological and confocal microscopy techniques, presents anatomical evidence that in rat and mouse retina, the horizontal cell processes are in contact with retinal capillaries as are retinal glial cells. This glia-like property of horizontal cells in these two species, also previously reported in tree shrews by Knabe and Ochs (1999), appear to be a more common theme for these neurons than previously appreciated.

  18. Stress and stress counselling.

    OpenAIRE

    Matheson, K. H.

    1990-01-01

    This is a report by the 1989 National Association of Clinical Tutors Wyeth Travelling Fellow to the United States of America. The stresses of postgraduate training and attempts to modify these are described, including stress counselling. The significance of stress and the relevance of the findings for postgraduate training in the United Kingdom are considered.

  19. Management of Horizontal Root Fracture in the Middle Third via Intraradicular Splinting Using a Fiber Post

    Directory of Open Access Journals (Sweden)

    Ishani Karhade

    2016-01-01

    Full Text Available Radicular fractures in permanent teeth are uncommon injuries and account for only 0.5–7% of dental traumas. These fractures commonly result from a horizontal impact and are transverse to oblique in direction. Their incidence is more in the middle third of the root than at the apical and cervical thirds. This paper describes a case of complicated crown fracture of maxillary incisors along with horizontal root fracture at the middle third of maxillary right central and lateral incisor. The fractured root fragments of the upper right central and lateral incisor were united with the help of a glass fiber post after receiving an endodontic treatment. The other two incisors were treated endodontically followed by post endodontic restorations. Eventually the four incisors were restored with porcelain fused to metal crowns. A one-year follow-up revealed a well stabilized assembly of the root fragments and the post.

  20. Effective use of a horizontally-transferred pathway for dichloromethane catabolism requires post-transfer refinement.

    Science.gov (United States)

    Michener, Joshua K; Camargo Neves, Aline A; Vuilleumier, Stéphane; Bringel, Françoise; Marx, Christopher J

    2014-11-24

    When microbes acquire new abilities through horizontal gene transfer, the genes and pathways must function under conditions with which they did not coevolve. If newly-acquired genes burden the host, their utility will depend on further evolutionary refinement of the recombinant strain. We used laboratory evolution to recapitulate this process of transfer and refinement, demonstrating that effective use of an introduced dichloromethane degradation pathway required one of several mutations to the bacterial host that are predicted to increase chloride efflux. We then used this knowledge to identify parallel, beneficial mutations that independently evolved in two natural dichloromethane-degrading strains. Finally, we constructed a synthetic mobile genetic element carrying both the degradation pathway and a chloride exporter, which preempted the adaptive process and directly enabled effective dichloromethane degradation across diverse Methylobacterium environmental isolates. Our results demonstrate the importance of post-transfer refinement in horizontal gene transfer, with potential applications in bioremediation and synthetic biology.

  1. Childhood Stress

    Science.gov (United States)

    ... Safe Videos for Educators Search English Español Childhood Stress KidsHealth / For Parents / Childhood Stress What's in this ... and feel stress to some degree. Sources of Stress Stress is a function of the demands placed ...

  2. Stress Management

    Science.gov (United States)

    Healthy Lifestyle Stress management By Mayo Clinic Staff Stress basics Stress is a normal psychological and physical ... of life. Start practicing stress management techniques today. Stress relief The pace and challenges of modern life ...

  3. Presenting directions with a vibrotactile torso display

    NARCIS (Netherlands)

    Erp, J.B.F. van

    2005-01-01

    Vibrotactile displays covering the torso present spatial information in an intuitive way since the stimuli are directly mapped to the body coordinates; left is left, front is front, etc. The present study investigated the direction in the horizontal plane to which a specific torso location is mapped

  4. Strong horizontal photospheric magnetic field in a surface dynamo simulation

    NARCIS (Netherlands)

    SchÜssler, M.; Vögler, A.|info:eu-repo/dai/nl/323397212

    2008-01-01

    Context. Observations with the Hinode spectro-polarimeter have revealed strong horizontal internetwork magnetic fields in the quiet solar photosphere. Aims. We aim to interpret the observations with results from numerical simulations. Methods. Radiative MHD simulations of dynamo action by

  5. Horizontal running mattress suture modified with intermittent simple loops.

    Science.gov (United States)

    Chacon, Anna H; Shiman, Michael I; Strozier, Narissa; Zaiac, Martin N

    2013-01-01

    Using the combination of a horizontal running mattress suture with intermittent loops achieves both good eversion with the horizontal running mattress plus the ease of removal of the simple loops. This combination technique also avoids the characteristic railroad track marks that result from prolonged non-absorbable suture retention. The unique feature of our technique is the incorporation of one simple running suture after every two runs of the horizontal running mattress suture. To demonstrate its utility, we used the suturing technique on several patients and analyzed the cosmetic outcome with post-operative photographs in comparison to other suturing techniques. In summary, the combination of running horizontal mattress suture with simple intermittent loops demonstrates functional and cosmetic benefits that can be readily taught, comprehended, and employed, leading to desirable aesthetic results and wound edge eversion.

  6. Vertical and horizontal spheroidal boundary-value problems

    Science.gov (United States)

    Šprlák, Michal; Tangdamrongsub, Natthachet

    2017-12-01

    Vertical and horizontal spheroidal boundary-value problems (BVPs), i.e., determination of the external gravitational potential from the components of the gravitational gradient on the spheroid, are discussed in this article. The gravitational gradient is decomposed into the series of the vertical and horizontal vector spheroidal harmonics, before being orthogonalized in a weighted sense by two different approaches. The vertical and horizontal spheroidal BVPs are then formulated and solved in the spectral and spatial domains. Both orthogonalization methods provide the same analytical solutions for the vertical spheroidal BVP, and give distinct, but equivalent, analytical solutions for the horizontal spheroidal BVP. A closed-loop simulation is performed to test the correctness of the analytical solutions, and we investigate analytical properties of the sub-integral kernels. The systematic treatment of the spheroidal BVPs and the resulting mathematical equations extend the theoretical apparatus of geodesy and of the potential theory.

  7. Effect of horizontal wave barriers on ground vibration propagation.

    Science.gov (United States)

    Grau, L; Laulagnet, B

    2015-09-01

    The aim of this article is to introduce a method to mitigate ground surface vibration through a flexural plate coupled to the ground and acting as a horizontal wave barrier. Using the thin plate hypothesis, two flexural plates are coupled to the ground, the first plate being the excited plate and the second plate the horizontal wave barrier. For instance, the first plate may represent a slab track and be excited by the tramway wheels. A solution to the problem can be found using a spatial two-dimensional Fourier transform of the elastodynamics equation for the ground and a modal decomposition for the flexural plate vibration. The authors show that vibration is substantially mitigated by the horizontal wave barrier and depends on its thickness and width. When the top surface wavelength becomes smaller than twice the plate width, the horizontal wave barrier acts as a wave barrier in the frequency range of interest, i.e., from 20 Hz.

  8. Determination of Elastic Twist in Horizontal Axis Wind Turbines (HAWTs)

    Energy Technology Data Exchange (ETDEWEB)

    Stoddard, F.; Nelson, V.; Starcher, K.; Andrews, B.

    2006-06-01

    This report presents the results of a project at the Alternative Energy Institute (AEI) which measured and calculated the elastic twist of three representative composite horizontal-axis blades: Carter 300, Gougeon ESI 54, and UTRC 8 kW.

  9. Horizontal Branch stars as AmFm/HgMn stars

    OpenAIRE

    Michaud, G.; Richer, J.

    2008-01-01

    Recent observations and models for horizontal branch stars are briefly described and compared to models for AmFm stars. The limitations of those models are emphasized by a comparison to observations and models for HgMn stars.

  10. A dynamic framework for managing horizontal cooperation in logistics

    NARCIS (Netherlands)

    Verstrepen, Sven; Cools, Martine; Cruijssen, Frans; Dullaert, Wout

    2009-01-01

    This paper first explores the motives and drivers that Logistic Service Providers (LSPs) may feel to start up horizontal cooperation. Secondly, a classification supporting LSPs in their search for a suitable collaboration structure is developed based on distinguishing cooperation characteristics

  11. Determination of horizontal and vertical distribution of tree species in ...

    African Journals Online (AJOL)

    Determination of horizontal and vertical distribution of tree species in Turkey via Shuttle Radar Topography Mission (SRTM) satellite data and geographic information system: the case of Crimean pine ( Pinus nigra )

  12. Plasmid Diversity and Horizontal Transfer in Marine Sediment Microbial Communities

    National Research Council Canada - National Science Library

    Sobecky, Patricia

    2002-01-01

    .... While plasmid exchange is an important mechanism by which bacterial populations can evolve and adapt, there remains a lack of information regarding the role of horizontal plasmid-mediated transfer...

  13. [Horizontal transfer of antibiotic resistance genes in the environment].

    Science.gov (United States)

    Yang, Feng-Xia; Mao, Da-Qing; Luo, Yi; Wang, Qing; Mu, Quan-Hua

    2013-10-01

    The transfer of antibiotic resistance genes (ARGs), a new type of environmental pollutants, could have more adverse effects on the environment than the ARGs themselves, while the horizontal gene transfer (HGT) could be the most important propagation pathways of the ARGs, being one of the reasons for the growing pollution of ARGs in the environment. This paper systematically elaborated the molecular elements of the horizontal transfer of ARGs and the related affecting factors, which was of significance for investigating the molecular mechanisms of the horizontal transfer of the ARGs. In combining with the phylogenetic mechanisms of multiple antibiotic resistances, this paper also provided effective strategies to reduce the transfer and proliferation of ARGs in the environment. Based on the present contamination situations, the further researches on the horizontal transfer of ARGs in the environment were prospected.

  14. Rare occurrence of the left maxillary horizontal third molar impaction ...

    African Journals Online (AJOL)

    Rare occurrence of the left maxillary horizontal third molar impaction, the right maxillary third molar vertical impaction and the left mandibular third molar vertical impaction with inferior alveolar nerve proximity in a 30 year old female: a case report.

  15. Elasto-plastic frame under horizontal and vertical Gaussian excitation

    DEFF Research Database (Denmark)

    Ditlevsen, Ove Dalager; Tarp-Johansen, Niels Jacob; Randrup-Thomsen, S.

    1999-01-01

    /compression axial force. Assuming that the horizontal excitationof the traverse is Gaussian white noise, statistics related to the plastic displacement response are determinedby use of simulation based on the Slepian modelprocess method combined with envelope excursion properties. Besidesgiving physical insight...

  16. Influence of horizontal resolution and ensemble size on model performance

    CSIR Research Space (South Africa)

    Dalton, A

    2014-10-01

    Full Text Available model forecast fields onto observed gridded mid-summer rainfall over South Africa. Spearman rank correlations are initially used to compare the performance of models with varying horizontal resolution as well as ensemble size. Further verification...

  17. Research-, development- and demonstrationprogram for a KBS-3 repository with horizontal deposition; Forsknings-, utvecklings- och demonstrationsprogram foer ett KBS-3-foervar med horisontell deponering

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-12-01

    This report gives an account of what RD and D efforts that would be necessary in order to make a full comparison between a KBS-3 repository with horizontal deposition of several canisters in each deposition hole, and the reference design with vertical deposition. A horizontal repository has no deposition tunnels, since the canisters are deposited directly from the transport tunnels. This means that the excavated rock mass is much reduced, compared to vertical deposition. Economically, it is calculated that horizontal deposition can be about 1 billion SEK (about 100 million USD) cheaper. The costs for performing the RD and D program are estimated to 150 million SEK.

  18. Horizontal gaze palsy with progressive scoliosis: CT and MR findings

    Energy Technology Data Exchange (ETDEWEB)

    Bomfim, Rodrigo C.; Tavora, Daniel G.F.; Nakayama, Mauro; Gama, Romulo L. [Sarah Network of Rehabilitation Hospitals, Department of Radiology, Ceara (Brazil)

    2009-02-15

    Horizontal gaze palsy with progressive scoliosis (HGPPS) is a rare congenital disorder characterized by absence of conjugate horizontal eye movements and progressive scoliosis developing in childhood and adolescence. We present a child with clinical and neuroimaging findings typical of HGPPS. CT and MRI of the brain demonstrated pons hypoplasia, absence of the facial colliculi, butterfly configuration of the medulla and a deep midline pontine cleft. We briefly discuss the imaging aspects of this rare entity in light of the current literature. (orig.)

  19. Horizontal Coherence of Wave Forces on Vertical Wall Breakwaters

    DEFF Research Database (Denmark)

    Archetti, R.; Frigaard, Peter; Lamberti, A.

    2001-01-01

    of breaking waves for increasing wave height are estimated and compared with existing empirical formulae. The horizontal dimension of the breaker is investigated using two different methodologies: the first analyses the decreasing of the highest 1/250 force with increasing horizontal dimension of the caisson......, with special attention to the effects of wave spreading, and the second analyses the spatial correlation of impulsive force per unit length along the breakwater....

  20. SATURATED-SUBCOOLED STRATIFIED FLOW IN HORIZONTAL PIPES

    Energy Technology Data Exchange (ETDEWEB)

    Richard Schultz

    2010-08-01

    Advanced light water reactor systems are designed to use passive emergency core cooling systems with horizontal pipes that provide highly subcooled water from water storage tanks or passive heat exchangers to the reactor vessel core under accident conditions. Because passive systems are driven by density gradients, the horizontal pipes often do not flow full and thus have a free surface that is exposed to saturated steam and stratified flow is present.

  1. Targeting Horizontal Inequalities: Ethnicity, Equity, and Entrepreneurship in Malaysia

    OpenAIRE

    Edmund Terence Gomez

    2012-01-01

    This study examines whether the horizontal inequality policies in Malaysia that preferentially target the indigenous ethnic groups (Bumiputera) are the ideal tool to reduce racial conflict. It also reviews whether the employment of race-based (Bumiputera-biased) policies is an effective method to help nurture highly entrepreneurial small- and medium-sized enterprises (SMEs). The case of large Bumiputera enterprises indicates that horizontal inequality-based policies has unproductive outcomes....

  2. Widespread of horizontal gene transfer in the human genome.

    Science.gov (United States)

    Huang, Wenze; Tsai, Lillian; Li, Yulong; Hua, Nan; Sun, Chen; Wei, Chaochun

    2017-04-04

    A fundamental concept in biology is that heritable material is passed from parents to offspring, a process called vertical gene transfer. An alternative mechanism of gene acquisition is through horizontal gene transfer (HGT), which involves movement of genetic materials between different species. Horizontal gene transfer has been found prevalent in prokaryotes but very rare in eukaryote. In this paper, we investigate horizontal gene transfer in the human genome. From the pair-wise alignments between human genome and 53 vertebrate genomes, 1,467 human genome regions (2.6 M bases) from all chromosomes were found to be more conserved with non-mammals than with most mammals. These human genome regions involve 642 known genes, which are enriched with ion binding. Compared to known horizontal gene transfer regions in the human genome, there were few overlapping regions, which indicated horizontal gene transfer is more common than we expected in the human genome. Horizontal gene transfer impacts hundreds of human genes and this study provided insight into potential mechanisms of HGT in the human genome.

  3. Should sex-ratio distorting parasites abandon horizontal transmission?

    Science.gov (United States)

    2011-01-01

    Background Sex-ratio distorting parasites are of interest due to their effects upon host population dynamics and their potential to influence the evolution of host sex determination systems. In theory, the ability to distort host sex-ratios allows a parasite with efficient vertical (hereditary) transmission to dispense completely with horizontal (infectious) transmission. However, recent empirical studies indicate that some sex-ratio distorting parasites have retained the capability for horizontal transmission. Results Numerical simulations using biologically realistic parameters suggest that a feminising parasite is only likely to lose the capability for horizontal transmission if its host occurs at low density and/or has a male-biased primary sex ratio. It is also demonstrated that even a small amount of horizontal transmission can allow multiple feminising parasites to coexist within a single host population. Finally it is shown that, by boosting its host's rate of population growth, a feminising parasite can increase its own horizontal transmission and allow the invasion of other, more virulent parasites. Conclusions The prediction that sex-ratio distorting parasites are likely to retain a degree of horizontal transmission has important implications for the epidemiology and host-parasite interactions of these organisms. It may also explain the frequent co-occurrence of several sex-ratio distorting parasite species in nature. PMID:22188680

  4. Should sex-ratio distorting parasites abandon horizontal transmission?

    Directory of Open Access Journals (Sweden)

    Ironside Joseph E

    2011-12-01

    Full Text Available Abstract Background Sex-ratio distorting parasites are of interest due to their effects upon host population dynamics and their potential to influence the evolution of host sex determination systems. In theory, the ability to distort host sex-ratios allows a parasite with efficient vertical (hereditary transmission to dispense completely with horizontal (infectious transmission. However, recent empirical studies indicate that some sex-ratio distorting parasites have retained the capability for horizontal transmission. Results Numerical simulations using biologically realistic parameters suggest that a feminising parasite is only likely to lose the capability for horizontal transmission if its host occurs at low density and/or has a male-biased primary sex ratio. It is also demonstrated that even a small amount of horizontal transmission can allow multiple feminising parasites to coexist within a single host population. Finally it is shown that, by boosting its host's rate of population growth, a feminising parasite can increase its own horizontal transmission and allow the invasion of other, more virulent parasites. Conclusions The prediction that sex-ratio distorting parasites are likely to retain a degree of horizontal transmission has important implications for the epidemiology and host-parasite interactions of these organisms. It may also explain the frequent co-occurrence of several sex-ratio distorting parasite species in nature.

  5. Field synergy characteristics in condensation heat transfer with non-condensable gas over a horizontal tube

    Directory of Open Access Journals (Sweden)

    Junxia Zhang

    2017-05-01

    Full Text Available Field synergy characteristics in condensation heat transfer with non-condensable gas (NCG over a horizontal tube were numerically simulated. Consequently, synergy angles between velocity and pressure or temperature gradient fields, gas film layer thickness, and induced velocity and shear stress on gas–liquid interface were obtained. Results show that synergy angles between velocity and temperature gradient fields are within 73.2°–88.7° and ascend slightly with the increment in mainstream velocity and that the synergy is poor. However, the synergy angle between velocity and pressure gradient fields decreases intensively with the increase in mainstream velocity at θ ≤ 30°, thereby improving the pressure loss. As NCG mass fraction increases, the gas film layer thickness enlarges and the induced velocity and shear stress on gas–liquid interface decreases. The synergy angles between velocity and temperature gradient fields increase, and the synergy angles between velocity and pressure gradient fields change at θ = 70°, decrease at θ 70°. When the horizontal tube circumference angle increases, the synergy angles between velocity and temperature or pressure gradient fields decrease, the synergy between velocity and pressure fields enhances, and the synergy between velocity and temperature fields degrades.

  6. Fully coupled simulation of multiple hydraulic fractures to propagate simultaneously from a perforated horizontal wellbore

    Science.gov (United States)

    Zeng, Qinglei; Liu, Zhanli; Wang, Tao; Gao, Yue; Zhuang, Zhuo

    2017-05-01

    In hydraulic fracturing process in shale rock, multiple fractures perpendicular to a horizontal wellbore are usually driven to propagate simultaneously by the pumping operation. In this paper, a numerical method is developed for the propagation of multiple hydraulic fractures (HFs) by fully coupling the deformation and fracturing of solid formation, fluid flow in fractures, fluid partitioning through a horizontal wellbore and perforation entry loss effect. The extended finite element method (XFEM) is adopted to model arbitrary growth of the fractures. Newton's iteration is proposed to solve these fully coupled nonlinear equations, which is more efficient comparing to the widely adopted fixed-point iteration in the literatures and avoids the need to impose fluid pressure boundary condition when solving flow equations. A secant iterative method based on the stress intensity factor (SIF) is proposed to capture different propagation velocities of multiple fractures. The numerical results are compared with theoretical solutions in literatures to verify the accuracy of the method. The simultaneous propagation of multiple HFs is simulated by the newly proposed algorithm. The coupled influences of propagation regime, stress interaction, wellbore pressure loss and perforation entry loss on simultaneous propagation of multiple HFs are investigated.

  7. Translational Control of the SigR-Directed Oxidative Stress Response inStreptomycesvia IF3-Mediated Repression of a Noncanonical GTC Start Codon.

    Science.gov (United States)

    Feeney, Morgan A; Chandra, Govind; Findlay, Kim C; Paget, Mark S B; Buttner, Mark J

    2017-06-13

    The major oxidative stress response in Streptomyces is controlled by the sigma factor SigR and its cognate antisigma factor RsrA, and SigR activity is tightly controlled through multiple mechanisms at both the transcriptional and posttranslational levels. Here we show that sigR has a highly unusual GTC start codon and that this leads to another level of SigR regulation, in which SigR translation is repressed by translation initiation factor 3 (IF3). Changing the GTC to a canonical start codon causes SigR to be overproduced relative to RsrA, resulting in unregulated and constitutive expression of the SigR regulon. Similarly, introducing IF3* mutations that impair its ability to repress SigR translation has the same effect. Thus, the noncanonical GTC sigR start codon and its repression by IF3 are critical for the correct and proper functioning of the oxidative stress regulatory system. sigR and rsrA are cotranscribed and translationally coupled, and it had therefore been assumed that SigR and RsrA are produced in stoichiometric amounts. Here we show that RsrA can be transcribed and translated independently of SigR, present evidence that RsrA is normally produced in excess of SigR, and describe the factors that determine SigR-RsrA stoichiometry. IMPORTANCE In all sigma factor-antisigma factor regulatory switches, the relative abundance of the two proteins is critical to the proper functioning of the system. Many sigma-antisigma operons are cotranscribed and translationally coupled, leading to a generic assumption that the sigma and antisigma factors are produced in a fixed 1:1 ratio. In the case of sigR - rsrA , we show instead that the antisigma factor is produced in excess over the sigma factor, providing a buffer to prevent spurious release of sigma activity. This excess arises in part because sigR has an extremely rare noncanonical GTC start codon, and as a result, SigR translation initiation is repressed by IF3. This finding highlights the potential significance

  8. Crustal stress pattern in China and its adjacent areas

    Science.gov (United States)

    Hu, Xingping; Zang, Arno; Heidbach, Oliver; Cui, Xiaofeng; Xie, Furen; Chen, Jiawei

    2017-11-01

    During the update of the World Stress Map (WSM) database, we integrated the China stress database by strictly using the internationally developed quality ranking scheme for each individual stress data record. This effort resulted in a comprehensive and reliable dataset for the crustal stress of China and its adjacent areas with almost double the amount of data records from the WSM database release 2008, i.e., a total of 8228 data records with reliable A-C qualities in the region of 45-155° East and 0-60° North. We use this dataset for an analysis of the stress pattern for the orientation of maximum compressive horizontal stress (SHmax). In contrast to earlier findings that suggested that the mean SHmax orientation would be aligned with the direction of plate motion, we clearly see from our results that the plate boundary forces, as well as topography and faulting, are important control factors for the overall stress pattern. Furthermore, the smoothing results indicate that the SHmax orientation in China rotates clockwise from the west to the east, which results in a fan-shaped crustal stress pattern for the continental scale. The plate boundary forces around China, which are the Indian-Eurasian plate collision in the west and the Pacific plate subduction and the push from the Philippine plate in the east, can still be seen as the key driving processes and the first-order controls for the crustal stress pattern. The South-North seismic zone can be seen as the separation zone for the western and eastern plate boundary forces. Topographic variation and faulting activity, however, provide second-order changes, and lead to local variations and different inhomogeneity scales for the stress pattern. Due to differences in these factors, Northeast China and the central part of the Tibetan plateau have notably homogeneous stress patterns, while the South-North seismic zone, the Hindu Kush-Pamir region, and the Taiwan region have extremely inhomogeneous stress patterns

  9. Reconstruction of orientation of stresses acting in infinity within the Kovdor ore body based on field determinations

    Directory of Open Access Journals (Sweden)

    Rybin V. V.

    2017-03-01

    Full Text Available Mining Institute KSC RAS has conducted research which aim is to study the possibilities of increasing the tilt angles of pit walls in massifs of solid rock. One of the problems the solution of which will contribute to achieving this goal is to determine the direction of the maximum component of principal stresses in intact massif on the "infinity" necessary to work out mathematical models of rock massif including quarry recess. To solve this problem it has been proposed to use the results of parameters' measurement of stress state by the unloading method in near-wall rock massif. The basic research of near-wall rock massif has been conducted on mine quarry "Zhelezny" (JSC "Kovdor ore processing plant". The measurements have been performed by the discharge method in option of end measurements directly from the quarry ledges on special observation stations using horizontal wells. The direction of maximum compression acting in sub-meridional course in the Kovdor apatiteshtafelyte-baddeleite deposit (the Kovdor ore cluster has been determined by the conformal mapping method on the basis of experimental estimations of stress parameters in the rock massif. The results obtained are of great importance for assessing a level of stresses acting directly in a near open-pit zone. They are applied to set boundary conditions when modeling stress-strain state of near-wall rock massif and assess slope stability.

  10. Stress and Health

    DEFF Research Database (Denmark)

    Rod, Naja Hulvej

    2014-01-01

    and the pathways underlying these potential health effects are far from elucidated. The dissertation contributions to the literature on stress and health by empirically testing the relationship between stress and major chronic disorders and by providing new evidence on the underlying physiological, psychological...... of pathways. The physiological stress response has the ability to directly affect vital body systems including the cardiovascular, immune, and metabolic systems. Further, stress can lead to unfavorable changes in health-related behavior, impaired sleep and poor mental health. An increasing number of well......Background Stress is an important public health issue. One in ten Danish adults experience high levels of stress in their daily lives and stress is one of the main occupational health problems in Europe. The link between stress and health is still debated in the scientific literature...

  11. Stress and Health

    DEFF Research Database (Denmark)

    Rod, Naja Hulvej

    2014-01-01

    Background Stress is an important public health issue. One in ten Danish adults experience high levels of stress in their daily lives and stress is one of the main occupational health problems in Europe. The link between stress and health is still debated in the scientific literature......, breast cancer, Parkinson’s disease and atopic disorders. The dissertation also aims to empirically test the relationship between measures of stress and total and cause-specific mortality, which provides a measure of the combined public health burden. Understanding the mechanisms linking stress to chronic...... of pathways. The physiological stress response has the ability to directly affect vital body systems including the cardiovascular, immune, and metabolic systems. Further, stress can lead to unfavorable changes in health-related behavior, impaired sleep and poor mental health. An increasing number of well...

  12. Descentralização, clientelismo e capital social na governança urbana: comparando Belo Horizonte e Salvador

    Directory of Open Access Journals (Sweden)

    Boschi Renato Raul

    1999-01-01

    Full Text Available In this comparison of Belo Horizonte?s and Salvador?s experiences within three arenas of local government, the article focuses on the viability of institutional arrangements based on decentralization and citizen participation. It concludes that the relative success achieved when inaugurating city master plans, participatory budgeting (where civil society has direct input in budget definitions, and sectoral councils (councils for decentralized policy issue areas is linked to three factors: prior decentralization processes; articulation between different decision-making units; and, above all, the neutralization of clientelistic control mechanisms through the introduction of horizontal loyalty networks and spaces of representation that in the final analysis will foster greater social capital and accountability.

  13. Replacing and Additive Horizontal Gene Transfer in Streptococcus

    Science.gov (United States)

    Choi, Sang Chul; Rasmussen, Matthew D.; Hubisz, Melissa J.; Gronau, Ilan; Stanhope, Michael J.; Siepel, Adam

    2012-01-01

    The prominent role of Horizontal Gene Transfer (HGT) in the evolution of bacteria is now well documented, but few studies have differentiated between evolutionary events that predominantly cause genes in one lineage to be replaced by homologs from another lineage (“replacing HGT”) and events that result in the addition of substantial new genomic material (“additive HGT”). Here in, we make use of the distinct phylogenetic signatures of replacing and additive HGTs in a genome-wide study of the important human pathogen Streptococcus pyogenes (SPY) and its close relatives S. dysgalactiae subspecies equisimilis (SDE) and S. dysgalactiae subspecies dysgalactiae (SDD). Using recently developed statistical models and computational methods, we find evidence for abundant gene flow of both kinds within each of the SPY and SDE clades and of reduced levels of exchange between SPY and SDD. In addition, our analysis strongly supports a pronounced asymmetry in SPY–SDE gene flow, favoring the SPY-to-SDE direction. This finding is of particular interest in light of the recent increase in virulence of pathogenic SDE. We find much stronger evidence for SPY–SDE gene flow among replacing than among additive transfers, suggesting a primary influence from homologous recombination between co-occurring SPY and SDE cells in human hosts. Putative virulence genes are correlated with transfer events, but this correlation is found to be driven by additive, not replacing, HGTs. The genes affected by additive HGTs are enriched for functions having to do with transposition, recombination, and DNA integration, consistent with previous findings, whereas replacing HGTs seen to influence a more diverse set of genes. Additive transfers are also found to be associated with evidence of positive selection. These findings shed new light on the manner in which HGT has shaped pathogenic bacterial genomes. PMID:22617954

  14. Nonlinear Dynamics of River Runoff Elucidated by Horizontal Visibility Graphs

    Science.gov (United States)

    Lange, Holger; Rosso, Osvaldo A.

    2017-04-01

    We investigate a set of long-term river runoff time series at daily resolution from Brazil, monitored by the Agencia Nacional de Aguas. A total of 150 time series was obtained, with an average length of 65 years. Both long-term trends and human influence (water management, e.g. for power production) on the dynamical behaviour are analyzed. We use Horizontal Visibility Graphs (HVGs) to determine the individual temporal networks for the time series, and extract their degree and their distance (shortest path length) distributions. Statistical and information-theoretic properties of these distributions are calculated: robust estimators of skewness and kurtosis, the maximum degree occurring in the time series, the Shannon entropy, permutation complexity and Fisher Information. For the latter, we also compare the information measures obtained from the degree distributions to those using the original time series directly, to investigate the impact of graph construction on the dynamical properties as reflected in these measures. Focus is on one hand on universal properties of the HVG, common to all runoff series, and on site-specific aspects on the other. Results demonstrate that the assumption of power law behaviour for the degree distribtion does not generally hold, and that management has a significant impact on this distribution. We also show that a specific pretreatment of the time series conventional in hydrology, the elimination of seasonality by a separate z-transformation for each calendar day, is highly detrimental to the nonlinear behaviour. It changes long-term correlations and the overall dynamics towards more random behaviour. Analysis based on the transformed data easily leads to spurious results, and bear a high risk of misinterpretation.

  15. Comparison of Beijing MST radar and radiosonde horizontal wind measurements

    Science.gov (United States)

    Tian, Yufang; Lü, Daren

    2017-01-01

    To determine the performance and data accuracy of the 50 MHz Beijing Mesosphere-Stratosphere-Troposphere (MST) radar, comparisons of radar measured horizontal winds in the height range 3-25 km with radiosonde observations were made during 2012. A total of 427 profiles and 15 210 data pairs were compared. There was very good agreement between the two types of measurement. Standard deviations of difference (mean difference) for wind direction, wind speed, zonal wind and meridional wind were 24.86° (0.77°), 3.37 (-0.44), 3.33 (-0.32) and 3.58 (-0.25) m s-1, respectively. The annual standard deviations of differences for wind speed were within 2.5-3 m s-1 at all heights apart from 10-15 km, the area of strong winds, where the values were 3-4 m s-1. The relatively larger differences were mainly due to wind field variations in height regions with larger wind speeds, stronger wind shear and the quasi-zero wind layer. A lower MST radar SNR and a lower percentage of data pairs compared will also result in larger inconsistencies. Importantly, this study found that differences between the MST radar and radiosonde observations did not simply increase when balloon drift resulted in an increase in the real-time distance between the two instruments, but also depended on spatiotemporal structures and their respective positions in the contemporary synoptic systems. In this sense, the MST radar was shown to be a unique observation facility for atmospheric dynamics studies, as well as an operational meteorological observation system with a high temporal and vertical resolution.

  16. Synaptic elements for GABAergic feed-forward signaling between HII horizontal cells and blue cone bipolar cells are enriched beneath primate S-cones.

    Science.gov (United States)

    Puller, Christian; Haverkamp, Silke; Neitz, Maureen; Neitz, Jay

    2014-01-01

    The functional roles and synaptic features of horizontal cells in the mammalian retina are still controversial. Evidence exists for feedback signaling from horizontal cells to cones and feed-forward signaling from horizontal cells to bipolar cells, but the details of the latter remain elusive. Here, immunohistochemistry and confocal microscopy were used to analyze the expression patterns of the SNARE protein syntaxin-4, the GABA receptor subunits α1 and ρ, and the cation-chloride cotransporters NKCC and KCC2 in the outer plexiform layer of primate retina. In macaque retina, as observed previously in other species, syntaxin-4 was expressed on dendrites and axon terminals of horizontal cells at cone pedicles and rod spherules. At cones, syntaxin-4 appeared densely clustered in two bands, at horizontal cell dendritic tips and at the level of desmosome-like junctions. Interestingly, in the lower band where horizontal cells may synapse directly onto bipolar cells, syntaxin-4 was highly enriched beneath short-wavelength sensitive (S) cones and colocalized with calbindin, a marker for HII horizontal cells. The enrichment at S-cones was not observed in either mouse or ground squirrel. Furthermore, high amounts of both GABA receptor and cation-chloride cotransporter subunits were found beneath primate S-cones. Finally, while syntaxin-4 was expressed by both HI and HII horizontal cell types, the intense clustering and colocalization with calbindin at S-cones indicated an enhanced expression in HII cells. Taken together, GABA receptors beneath cone pedicles, chloride transporters, and syntaxin-4 are putative constituents of a synaptic set of proteins which would be required for a GABA-mediated feed-forward pathway via horizontal cells carrying signals directly from cones to bipolar cells.

  17. Stress field modelling from digital geological map data

    Science.gov (United States)

    Albert, Gáspár; Barancsuk, Ádám; Szentpéteri, Krisztián

    2016-04-01

    calculated from the fracture criterion. The calculation includes the gravitational acceleration, the average density of rocks and the experimental 60 degree of the fracture angle from the normal of the fault plane. This way, the stress tensors are calculated as absolute pressure values per square meters on both sides of the faults. If the stress from the overburden is greater than 1 bar (i.e. the faults are buried), a confined compression would be present. Modelling this state of stress may result a confusing pattern of vectors, because in a confined position the horizontal stress vectors may point towards structures primarily associated with extension. To step over this, and to highlight the variability in the stress-field, the model calculates the vectors directly from the differential stress (practically subtracting the minimum principal stress from the critical stress). The result of the modelling is a vector map, which theoretically represents the minimum tectonic pressure in the moment, when the rock body breaks from an initial state. This map - together with the original fault-map - is suitable for determining those areas where unrevealed tectonic, sedimentary and lithological structures are possibly present (e.g. faults, sub-basins and intrusions). With modelling different deformational phases on the same area, change of the stress vectors can be detected which reveals not only the varying directions of the principal stresses, but the tectonic-driven sedimentation patterns too. The decrease of necessary critical stress in the case of a possible reactivation of a fault in subsequent deformation phase can be managed with the down-ranking of the concerning structural elements. Reference: Albert G., Ungvári ZS., Szentpéteri K. 2014: Modeling the present day stress field of the Pannonian Basin from neotectonic maps - In: Beqiraj A, Ionescu C, Christofides G, Uta A, Beqiraj Goga E, Marku S (eds.) Proceedings XX Congress of the Carpathian-Balkan Geological Association

  18. Stress-Induced Borehole Failure in the SAFOD Pilot Hole: Implications for the Strength of the San Andreas Fault at Parkfield

    Science.gov (United States)

    Hickman, S.; Zoback, M.

    2002-12-01

    The San Andreas Fault Observatory at Depth (SAFOD) is a comprehensive project to drill, core and instrument an inclined borehole across the San Andreas Fault Zone to a depth of 4 km. A 2.2-km-deep vertical pilot hole was drilled in the summer of 2002 at the same surface location planned for SAFOD. This site is 1.8 km southwest of the San Andreas Fault near Parkfield, CA, on a segment of the fault that moves through a combination of aseismic creep and repeating microearthquakes. One of the primary goals of the pilot hole was to better define the thermomechanical setting of the San Andreas Fault Zone at Parkfield prior to drilling of the main SAFOD hole. Ultrasonic borehole televiewer logs acquired in the SAFOD pilot hole reveal extensive stress-induced borehole breakouts at depths from 0.8 to 2.2 km. Preliminary analysis of the orientations of these breakouts indicates that the direction of the maximum horizontal compressive stress, SHmax, is approximately 30° from the strike of the San Andreas Fault to a depth of ~1.6 km. However, a clockwise stress rotation is observed with increasing depth such that the SHmax direction approaches 70° to the strike of the fault at 2.0 to 2.2 km. This lowermost stress orientation is in fairly good agreement with SHmax directions seen at much greater distances (>10-20 km) from the San Andreas Fault in central California. Although the absolute magnitudes of the horizontal principal stresses will not be known until hydraulic fracturing tests are conducted in the pilot hole next year, observations of drilling-induced tensile fractures in a Formation Micro-Imager log confirm these stress orientations and indicate that the horizontal differential stress in the crust adjacent to the fault may be quite high. If so, then the upper ~1.6 km of the San Andreas Fault at Parkfield is supporting the levels of shear stress predicted by Byerlee's law for those depths. However, the rotation of SHmax toward fault-normal compression at greater depth

  19. Cleanup/stimulation of a horizontal wellbore using propellants

    Energy Technology Data Exchange (ETDEWEB)

    Rougeot, J.E.; Lauterbach, K.A.

    1993-01-01

    This report documents the stimulation/cleanup of a horizontal well bore (Wilson 25) using propellants. The Wilson 25 is a Bartlesville Sand well located in the Flatrock Field, Osage County, Oklahoma. The Wilson 25 was drilled to determine if horizontal drilling could be used as a means to economically recover primary oil that had been left in place in a mostly abandoned oil field because of the adverse effects of water coning. Pump testing of the Wilson 25 horizontal well bore before cleanup or stimulation produced 6 barrels of oil and .84 barrels of water per day. The high percentage of daily oil production to total daily fluid production indicated that the horizontal well bore had accessed potentially economical oil reserves if the fluid production rate could be increased by performing a cleanup/stimulation treatment. Propellants were selected as an inexpensive means to stimulate and cleanup the near well bore area in a uniform manner. The ignition of a propellant creates a large volume of gas which penetrates the formation, creating numerous short cracks through which hydrocarbons can travel into the well bore. More conventional stimulation/cleanup techniques were either significantly more expensive, less likely to treat uniformly, or could not be confined to the near well bore area. Three different propellant torpedo designs were tested with a total of 304' of horizontal well bore being shot and producible. The initial test shot caused 400' of the horizontal well bore to become plugged off, and subsequently it could not be production tested. The second and third test shots were production tested, with the oil production being increased 458% and 349%, respectively, on a per foot basis. The Wilson 25 results indicate that a propellant shot treatment is an economically viable means to cleanup/stimulate a horizontal well bore.

  20. Effective Stress Approximation using Geomechanical Formulation of Fracturing Technology (GFFT) in Petroleum Reservoirs

    Science.gov (United States)

    Haghi, A.; Asef, M.; Kharrat, R.

    2010-12-01

    Recently, rock mechanics and geophysics contribution in petroleum industry has been significantly increased. Wellbore stability analysis in horizontal wells, sand production problem while extracting hydrocarbon from sandstone reservoirs, land subsidence due to production induced reservoir compaction, reservoir management, casing shearing are samples of these contributions. In this context, determination of the magnitude and orientation of the in-situ stresses is an essential parameter. This paper is presenting new method to estimate the magnitude of in-situ stresses based on fracturing technology data. Accordingly, kirsch equations for the circular cavities and fracturing technology models in permeable formations have been used to develop an innovative Geomechanical Formulation (GFFT). GFFT introduces a direct reasonable relation between the reservoir stresses and the breakdown pressure of fracture, while the concept of effective stress was employed. Thus, this complex formula contains functions of some rock mechanic parameters such as poison ratio, Biot’s coefficient, Young’s modulus, rock tensile strength, depth of reservoir and breakdown/reservoir pressure difference. Hence, this approach yields a direct method to estimate maximum and minimum effective/insitu stresses in an oil field and improves minimum in-situ stress estimation compared to previous studies. In case of hydraulic fracturing; a new stress analysis method is developed based on well known Darcy equations for fluid flow in porous media which improves in-situ stress estimation using reservoir parameters such as permeability, and injection flow rate. The accuracy of the method would be verified using reservoir data of a case history. The concepts discussed in this research would eventually suggest an alternative methodology with sufficient accuracy to derive in-situ stresses in hydrocarbon reservoirs, while no extra experimental work is accomplished for this purpose.

  1. Una propuesta de horizontal verdadera: Estudio preliminar A proposal of True Horizontal. A preliminary study

    Directory of Open Access Journals (Sweden)

    Alma Lucía Castro Lara

    2004-04-01

    Full Text Available El propósito de este estudio fue abordar una propuesta de horizontal verdadera a través del punto T y compararla con los planos de Frankfort y Silla-Nasion. La muestra estuvo conformada por 15 jóvenes de 19-24 años y de ambos sexos, con oclusión normal, procedentes de Culiacán, Sinaloa, México. Las radiografías laterales de cráneo se obtuvieron ubicando al paciente con referencia a la posición natural de la cabeza. Los planos FH y SN se relacionaron con los puntos A, B y Pogonion para establecer diferencias entre las mediciones angulares y lineales. Al analizar el plano de FH en relación con la vertical verdadera, detectamos 8,4º± 3,0 de inclinación y el plano SN mostró igualmente una inclinación de 11,4º. En las variables lineales a la vertical de cada uno de los planos resultaron con diferencias estadísticas; se observó que para VFH-A (p The purpose of this study was to undertake a proposal of True Horizontal through the point "T" and compare it with the Frankfort and Sella-Nasion planes. The sample was composed of 15 young adults aged 19-24 years, both sexes, from Culiacán, Sinaloa, Mexico. They all had normal occlusion. The lateral skull x-rays were made by placing the patient with reference to the natural head position. FH and SN planes were related to points A,B and Pogonion to set differences between angle and linear measurements. In analyzing the FH plane in respect to True Vertical, there were 8.4° ± 3.0 inclination in FH plane and 11.4° in plane SN. The linear variables to the vertical of each of the planes showed statistical differences VFH-A (p< 0.0166, VSN-A (p< 0.0217 and those values related to point B were observed. A similar behavior was found in variables at point Pg where the values of VFH-Pg with VTH-Pg compared to VSN-Pg with VTH-Pg showed statistical differences, finding that they matched with the clinical characteristics of the studied sample. It is necessary to go deeper into these studies so as to

  2. Korea's Horizontal and Vertical Intra-Industry Trade and FDI in Trade with East Asian Countries

    Directory of Open Access Journals (Sweden)

    Taegi Kim

    2007-06-01

    Full Text Available This paper examines Korea's intra-industry trade (IIT by disentangling vertical from horizontal IIT, and analyzes the determinants of both IIT types in trade with East Asian countries during the period of 1991-2005. Korea's IIT with East Asian countries has increased rapidly, especially its high quality IIT, which has increased faster than horizontal IIT and low quality IIT, implying that Korea's product quality has improved over time. Korea's high quality IIT is larger in trade with developing countries, but its low quality IIT is larger in trade with Japan. The regression results show that the income differences between countries have a negative effect on horizontal IIT, and that Korea's high quality IIT becomes larger when Korea's income is higher than the income of partner countries. This supports the theory of IIT. Foreign direct investment (FDI inflow has had a positive effect on increases in IIT, but the effects of FDI outflow are not certain. This suggests a policy implication that FDI inflow has a more positive effect on IIT than FDI outflow.

  3. Allelic ROBO3 heterogeneity in Tunisian patients with horizontal gaze palsy with progressive scoliosis.

    Science.gov (United States)

    Amouri, Rim; Nehdi, Houda; Bouhlal, Yosr; Kefi, Mounir; Larnaout, Abdelmajid; Hentati, Fayçal

    2009-11-01

    Horizontal gaze palsy with progressive scoliosis (HGPPS) is a rare autosomal recessive disorder characterized by the congenital absence of horizontal gaze, progressive scoliosis, and failure of the corticospinal and somatosensory axon tracts to decussate in the medulla. HGPPS is caused by mutations of the ROBO3 gene, which encodes a protein that shares homology with the roundabout family of transmembrane receptors that are important in axon guidance and neuronal migration. To date, over 15 mutations have been found in consanguineous families of Greek, Italian, Turkish, Pakistani, Saudi Arabian, and Indian descent. To detail clinical, cerebral magnetic resonance imaging (MRI) and genetic findings of ten HGPPS patients from four unrelated Tunisian families. Four unrelated consanguineous Tunisian families with a total of ten patients suffering from horizontal gaze palsy with progressive scoliosis. Genetic linkage analysis and direct sequencing of the ROBO3 gene. All patients shared similar clinical gaze movement abnormalities and variable degrees of scoliosis. Four distinct homozygous mutations were identified. This study extends the molecular spectrum of the ROBO3 gene and the geographic origin of patients with ROBO3 gene mutations, and underlines the homogeneity of the motor ocular syndrome whatever type of mutation is encountered.

  4. Horizontal nystagmus and multiple sclerosis using 3-Tesla magnetic resonance imaging.

    Science.gov (United States)

    Iyer, P M; Fagan, A J; Meaney, J F; Colgan, N C; Meredith, S D; Driscoll, D O; Curran, K M; Bradley, D; Redmond, J

    2016-11-01

    Nystagmus in patients with multiple sclerosis (MS) is generally attributed to brainstem disease. Lesions in other regions may result in nystagmus. The identification of these other sites is enhanced by using 3-Tesla magnetic resonance imaging (3TMRI) due to increased signal-to-noise ratio. We sought to evaluate the distribution of structural lesions and disruption of tracts in patients with horizontal nystagmus secondary to MS using 3TMRI. Twenty-four patients (20 women, 4 men; age range 26-55 years) with horizontal nystagmus secondary to MS underwent 3TMRI brain scans; and 18 patients had diffusion tensor imaging (DTI) for tractography. Nystagmus was bidirectional in 11, right-sided in 6 and left-sided in 7. We identified 194 lesions in 20 regions within the neural integrator circuit in 24 patients; 140 were within the cortex and 54 were within the brainstem. Only two patients had no lesions in the cortex, and 9 had no lesions in the brainstem. There was no relationship between side of lesion and direction of nystagmus. Thirteen of 18 (72 %) had tract disruption with fractional anisotropy (FA) values below 0.2. FA was significantly lower in bidirectional compared to unidirectional nystagmus (p = 0.006). In MS patients with horizontal nystagmus, lesions in all cortical eye fields and their descending connections were evident. Technical improvements in tractography may help identify the specific site(s) resulting in nystagmus in MS.

  5. First successful multistage hydraulic fracture monitoring for a horizontal well in Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Gutierrez, Guillermo; Rios, Austreberto; Riano, Juan M. [PEMEX, Mexico, DF (Mexico); Sanchez, Adrian; Bustos, Tomas [Schlumberger, Mexico DF (Mexico)

    2008-07-01

    In their constant effort to increase the production from Chicontepec, PEMEX drilled a multilateral well with three horizontal lateral sections; the intention was to increase the production in comparison with vertical wells. In the second arm of this well four intervals were identified to be fractured, this was a new approach since it was the first occasion that multiple fractures were planned in a horizontal well. An important part of the project was the evaluation of the effectiveness of the hydraulic fracturing. This evaluation was performed by micro seismic monitoring during the treatment. This technology allows the detection of events generated during the fluid injection in the reservoir, with receivers located in a nearby monitoring well. The interpretation of this data allows the identification in 3 D space of the fracture locations. This information is valuable for optimization of subsequent treatments and for planning the field development. The data is recorded in real time and can be used to make decisions during the fracturing operation. In this paper we describe the results of the hydraulic fracturing monitoring performed in four intervals in a horizontal well showing the geometry and direction of each one of the fractures. (author)

  6. Optimizing for Large Planar Fractures in Multistage Horizontal Wells in Enhanced Geothermal Systems Using a Coupled Fluid and Geomechanics Simulator

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Xiexiaomen; Tutuncu, Azra; Eustes, Alfred; Augustine, Chad

    2017-05-01

    Enhanced Geothermal Systems (EGS) could potentially use technological advancements in coupled implementation of horizontal drilling and multistage hydraulic fracturing techniques in tight oil and shale gas reservoirs along with improvements in reservoir simulation techniques to design and create EGS reservoirs. In this study, a commercial hydraulic fracture simulation package, Mangrove by Schlumberger, was used in an EGS model with largely distributed pre-existing natural fractures to model fracture propagation during the creation of a complex fracture network. The main goal of this study is to investigate optimum treatment parameters in creating multiple large, planar fractures to hydraulically connect a horizontal injection well and a horizontal production well that are 10,000 ft. deep and spaced 500 ft. apart from each other. A matrix of simulations for this study was carried out to determine the influence of reservoir and treatment parameters on preventing (or aiding) the creation of large planar fractures. The reservoir parameters investigated during the matrix simulations include the in-situ stress state and properties of the natural fracture set such as the primary and secondary fracture orientation, average fracture length, and average fracture spacing. The treatment parameters investigated during the simulations were fluid viscosity, proppant concentration, pump rate, and pump volume. A final simulation with optimized design parameters was performed. The optimized design simulation indicated that high fluid viscosity, high proppant concentration, large pump volume and pump rate tend to minimize the complexity of the created fracture network. Additionally, a reservoir with 'friendly' formation characteristics such as large stress anisotropy, natural fractures set parallel to the maximum horizontal principal stress (SHmax), and large natural fracture spacing also promote the creation of large planar fractures while minimizing fracture complexity.

  7. Two-Component Signaling System VgrRS Directly Senses Extracytoplasmic and Intracellular Iron to Control Bacterial Adaptation under Iron Depleted Stress.

    Directory of Open Access Journals (Sweden)

    Li Wang

    2016-12-01

    Full Text Available Both iron starvation and excess are detrimental to cellular life, especially for animal and plant pathogens since they always live in iron-limited environments produced by host immune responses. However, how organisms sense and respond to iron is incompletely understood. Herein, we reveal that in the phytopathogenic bacterium Xanthomonas campestris pv. campestris, VgrS (also named ColS is a membrane-bound receptor histidine kinase that senses extracytoplasmic iron limitation in the periplasm, while its cognate response regulator, VgrR (ColR, detects intracellular iron excess. Under iron-depleted conditions, dissociation of Fe3+ from the periplasmic sensor region of VgrS activates the VgrS autophosphorylation and subsequent phosphotransfer to VgrR, an OmpR-family transcription factor that regulates bacterial responses to take up iron. VgrR-VgrS regulon and the consensus DNA binding motif of the transcription factor VgrR were dissected by comparative proteomic and ChIP-seq analyses, which revealed that in reacting to iron-depleted environments, VgrR directly or indirectly controls the expressions of hundreds of genes that are involved in various physiological cascades, especially those associated with iron-uptake. Among them, we demonstrated that the phosphorylated VgrR tightly represses the transcription of a special TonB-dependent receptor gene, tdvA. This regulation is a critical prerequisite for efficient iron uptake and bacterial virulence since activation of tdvA transcription is detrimental to these processes. When the intracellular iron accumulates, the VgrR-Fe2+ interaction dissociates not only the binding between VgrR and the tdvA promoter, but also the interaction between VgrR and VgrS. This relieves the repression in tdvA transcription to impede continuous iron uptake and avoids possible toxic effects of excessive iron accumulation. Our results revealed a signaling system that directly senses both extracytoplasmic and intracellular

  8. Horizontally resolved structures of polar mesospheric echoes obtained with the Middle Atmosphere Alomar Radar System

    Science.gov (United States)

    Latteck, Ralph; Zecha, Marius; Rapp, Markus; Stober, Gunter; Singer, Werner

    2012-07-01

    Polar Mesosphere Summer Echoes have been observed in Andenes/Norway (69°N, 16°E) for more than 18 years using the Alomar SOUSY and the ALWIN VHF radars. In 2011 the Leibniz-Institute of Atmospheric Physics in Kühlungsborn completed the installation of the Middle Atmosphere Alomar Radar System ({MAARSY}). The new radar is designed for atmospheric studies from the troposphere up to the lower thermosphere, especially for the investigation of horizontal structures of polar mesospheric echoes. The system is composed of an active phased antenna consisting of 433 array elements and an identical number of transceiver modules individually controllable in frequency, phase, and output power on a pulse-to-pulse basis. This arrangement allows very high flexibility of beam forming and beam steering with a symmetric 3.6° small radar beam and arbitrary beam pointing directions down to 30° off-zenith. The monitoring of polar mesosphere echoes using a vertical pointed radar beam has been continued already during the construction period of MAARSY in order to complete the long term data base available for Andenes. Additionally first multi-beam scanning experiments using up to 97 beams quasi-simultaneously in the mesosphere have been carried out during several campaigns starting in summer 2010. Sophisticated wind analysis methods such as an extended velocity azimuth display have been applied to retrieve additional parameters from the wind field, e.g. horizontal divergence, vertical velocity, stretching and shearing deformation. The results provide a first insight into the strong horizontal variability of scattering structures occurring in the polar mesosphere over Andenes during summer and winter time. The implementation of interferometric radar imaging methods offers further improvement of the horizontal and the vertical resolution.

  9. Large-Actuator-Number Horizontal Path Correction of Atmospheric Turbulence utilizing an Interferometric Phase Conjugate Engine

    Energy Technology Data Exchange (ETDEWEB)

    Baker, K L; Stappaerts, E A; Gavel, D; Tucker, J; Silva, D A; Wilks, S C; Olivier, S S; Olsen, J

    2004-08-25

    An adaptive optical system used to correct horizontal beam propagation paths has been demonstrated. This system utilizes an interferometric wave-front sensor and a large-actuator-number MEMS-based spatial light modulator to correct the aberrations incurred by the beam after propagation along the path. Horizontal path correction presents a severe challenge to adaptive optics systems due to the short atmospheric transverse coherence length and the high degree of scintillation incurred by laser propagation along these paths. Unlike wave-front sensors that detect phase gradients, however, the interferometric wave-front sensor measures the wrapped phase directly. Because the system operates with nearly monochromatic light and uses a segmented spatial light modulator, it does not require that the phase be unwrapped to provide a correction and it also does not require a global reconstruction of the wave-front to determine the phase as required by gradient detecting wave-front sensors. As a result, issues with branch points are eliminated. Because the atmospheric probe beam is mixed with a large amplitude reference beam, it can be made to operate in a photon noise limited regime making its performance relatively unaffected by scintillation. The MEMS-based spatial light modulator in the system contains 1024 pixels and is controlled to speeds in excess of 800 Hz, enabling its use for correction of horizontal path beam propagation. In this article results are shown of both atmospheric characterization with the system and open loop horizontal path correction of a 1.53 micron laser by the system. To date Strehl ratios of greater than 0.5 have been achieved.

  10. Influence of pavement condition on horizontal curve safety.

    Science.gov (United States)

    Buddhavarapu, Prasad; Banerjee, Ambarish; Prozzi, Jorge A

    2013-03-01

    Crash statistics suggest that horizontal curves are the most vulnerable sites for crash occurrence. These crashes are often severe and many involve at least some level of injury due to the nature of the collisions. Ensuring the desired pavement surface condition is one potentially effective strategy to reduce the occurrence of severe accidents on horizontal curves. This study sought to develop crash injury severity models by integrating crash and pavement surface condition databases. It focuses on developing a causal relationship between pavement condition indices and severity level of crashes occurring on two-lane horizontal curves in Texas. In addition, it examines the suitability of the existing Skid Index for safety maintenance of two-lane curves. Significant correlation is evident between pavement condition and crash injury severity on two-lane undivided horizontal curves in Texas. Probability of a crash becoming fatal is appreciably sensitive to certain pavement indices. Data suggested that road facilities providing a smoother and more comfortable ride are vulnerable to severe crashes on horizontal curves. In addition, the study found that longitudinal skid measurement barely correlates with injury severity of crashes occurring on curved portions. The study recommends exploring the option of incorporating lateral friction measurement into Pavement Management System (PMS) databases specifically at curved road segments. Copyright © 2012 Elsevier Ltd. All rights reserved.

  11. A Comparison between Horizontal and Vertical Interchannel Decorrelation

    Directory of Open Access Journals (Sweden)

    Christopher Gribben

    2017-11-01

    Full Text Available The perceptual effects of interchannel decorrelation on perceived image spread have been investigated subjectively in both horizontal and vertical stereophonic reproductions, looking specifically at the frequency dependency of decorrelation. Fourteen and thirteen subjects graded the horizontal and vertical image spreads of a pink noise sample, respectively. The pink noise signal had been decorrelated by a complementary comb-filter decorrelation algorithm, varying the frequency-band, time-delay and decorrelation factor for each sample. Results generally indicated that interchannel decorrelation had a significant effect on auditory image spread both horizontally and vertically, with spread increasing as correlation decreases. However, it was found that the effect of vertical decorrelation was less effective than that of horizontal decorrelation. The results also suggest that the decorrelation effect was frequency-dependent; changes in horizontal image spread were more apparent in the high frequency band, whereas those in vertical image spread were in the low band. Furthermore, objective analysis suggests that the perception of vertical image spread for the low and middle frequency bands could be associated with a floor reflection; whereas for the high band, the results appear to be related to spectral notches in the ear input signals.

  12. Maxillary repositioning according to Frankfort horizontal plane during orthognathic surgery.

    Science.gov (United States)

    Ghoreishian, Mehdi; Hasheminia, Dariush; Hashemzehi, Hadi; Khazaei, Saber

    2013-01-01

    There are a lot of disagreements among surgeons over controlling the maxillary position during orthognathic surgery. To investigate maxillary repositioning according to Frankfort horizontal plane in orthognathic surgery. Fourteen patients were selected who were submitted to maxillary or bimaxillary surgery. Maxillary model surgery was performed based on the treatment planning and an intermediate splint was made. The surgical technique in this study was based on maxillary osteotomy according to the findings of the model surgery, in a manner that the osteotomy line was parallel to the Frankfort horizontal plane. Intermediate splint was used for repositioning of the maxilla in the new position and the vertical position of that was determined according to external reference point and fixed on this position. The upper central incisor designed from prediction tracing and post-operative cephalometry on the first tracing. The new position of maxilla was evaluated horizontally and vertically. A paired t-test was used to compare the predicted maxillary position and the actual position. Association between these two groups of variables was evaluated with Pearson correlation. The mean difference between the maxillary planned position and post-operative cephalometric radiography varied between 0.3 mm and 0.9 mm vertically (P value = 0.315) and 0.0 mm and 0.9 mm horizontally (P value = 0.034). The averages of horizontally and vertically observed changes were 0.3 mm and 0.17 mm respectively (P surgery. By eliminating the ramping effect the accuracy of surgery increases.

  13. Regadenoson, a Novel Pharmacologic Stress Agent for Use in Myocardial Perfusion Imaging, Does Not Have a Direct Effect on the QT Interval in Conscious Dogs

    Science.gov (United States)

    Zhao, Gong; Serpllion, Sabrina; Shryock, John; Messina, Eric; Xu, Xiaobin; Ochoa, Manuel; Belardinelli, Luiz; Hintze, Thomas H

    2009-01-01

    Our goal was to determine the effect of regadenoson (a novel A2A adenosine receptor agonist) on the QT interval in conscious dogs. Eleven mongrel dogs were chronically instrumented for measurements of blood pressure and ECG. Regadenoson (2.5, 5 and 10 μg/kg, IV) caused a dose-dependent QT interval shortening (ΔQT: 14±3, 24±5 and 27±5 ms, mean±SEM, n=7-11, all pRegadenoson- and pacing-induced shortenings in the QT interval were significantly correlated with the R-R interval (r= 0.67 and 0.8, both pRegadenoson at 5 and 10 μg/kg did not cause a significant change in HR or QT interval either during atrial pacing at 165 bpm or after administration of propranolol and atropine to prevent HR from changing, or after treatment of dogs with hexamethonium to block autonomic ganglia. Regadenoson (5-10 μg/kg) caused no significant changes of QT interval in the heart in which HR was kept constant via physiological or pharmacological procedures, indicating that regadenoson has no a direct effect on the QT interval. PMID:19033827

  14. Regadenoson, a novel pharmacologic stress agent for use in myocardial perfusion imaging, does not have a direct effect on the QT interval in conscious dogs.

    Science.gov (United States)

    Zhao, Gong; Serpllion, Sabrina; Shryock, John; Messina, Eric; Xu, Xiaobin; Ochoa, Manuel; Belardinelli, Luiz; Hintze, Thomas H

    2008-11-01

    Our goal was to determine the effect of regadenoson (a novel A2A adenosine receptor agonist) on the QT interval in conscious dogs. Sixteen mongrel dogs were chronically instrumented for measurements of blood pressure and ECG. Regadenoson (2.5, 5, and 10 microg/kg, IV) caused a dose-dependent QT interval shortening (DeltaQT: 14 +/- 3, 24 +/- 5, and 27 +/- 5 ms, mean +/- SEM; n = 7 to 11; all P Regadenoson- and pacing-induced shortenings in the QT interval were significantly correlated with the R-R interval (r = 0.67 and 0.8, both P Regadenoson at 5 and 10 microg/kg did not cause a significant change in HR or QT interval either during atrial pacing at 165 bpm or after administration of propranolol and atropine to prevent HR from changing or after treatment of dogs with hexamethonium to block autonomic ganglia. Regadenoson (5 to 10 microg/kg) caused no significant changes of QT interval in the heart in which HR was kept constant via physiological or pharmacological procedures, indicating that regadenoson has no direct effect on the QT interval.

  15. Direct-contact closed-loop heat exchanger

    Energy Technology Data Exchange (ETDEWEB)

    Berry, Gregory F. (Naperville, IL); Minkov, Vladimir (Skokie, IL); Petrick, Michael (Joliet, IL)

    1984-01-01

    A high temperature heat exchanger with a closed loop and a heat transfer liquid within the loop, the closed loop having a first horizontal channel with inlet and outlet means for providing direct contact of a first fluid at a first temperature with the heat transfer liquid, a second horizontal channel with inlet and outlet means for providing direct contact of a second fluid at a second temperature with the heat transfer liquid, and means for circulating the heat transfer liquid.

  16. Manage Stress

    Science.gov (United States)

    ... Manage Stress Print This Topic En español Manage Stress Browse Sections The Basics Overview Signs and Health ... and Health Effects What are the signs of stress? When people are under stress, they may feel: ...

  17. Stress Incontinence

    Science.gov (United States)

    Stress incontinence Overview Urinary incontinence is the unintentional loss of urine. Stress incontinence happens when physical movement or activity — such ... coughing, sneezing, running or heavy lifting — puts pressure (stress) on your bladder. Stress incontinence is not related ...

  18. Measuring Environmental Stress

    Science.gov (United States)

    Walker, John E.; Dahm, Douglas B.

    1975-01-01

    Infrared remote sensors, plus photometric interpretation and digital data analysis are being used to record the stresses on air, water, vegetation and soil. Directly recorded photographic information has been the most effective recording media for remote sensing. (BT)

  19. Statistical Analysis of Nitrogen in the Soil of Constructed Wetland with Horizontal Sub-Surface Flow

    Directory of Open Access Journals (Sweden)

    Jakubaszek Anita

    2014-06-01

    Full Text Available The removal of nitrogen compounds in constructed wetlands depends on various physical, chemical and biomechanical factors as well as on conditions of the environment. The paper presents the results of a statistical analysis of the depositing of nitrogen at HSSF (horizontal subsurface flow construcred wetland. The results of the substrate showed that the highest contents of nitrogen existed in the surface soil layer up to 20 cm of the depth. Nitrogen accumulation decreased in the deposit with depth, and in the direction of the wastewater flow.

  20. Investigation of the Geokinetics horizontal in situ oil-shale-retorting process. Fourth annual report, 1980

    Energy Technology Data Exchange (ETDEWEB)

    Hutchinson, D.L. (ed.)

    1981-03-01

    The Geokinetics in situ shale oil project is a cooperative venture between Geokinetics Inc. and the US Department of Energy. The objective is to develop a true in situ process for recovering shale oil using a fire front moving in a horizontal direction. The project is being conducted at a field site, Kamp Kerogen, located 70 miles south of Vernal, Utah. This Fourth Annual Report covers work completed during the calendar year 1980. During 1980 one full-size retort was blasted. Two retorts, blasted the previous year, were burned. A total of 4891 barrels of oil was produced during the year.