WorldWideScience

Sample records for lose balance slip

  1. Quantifying slip balance in the earthquake cycle: Coseismic slip model constrained by interseismic coupling

    KAUST Repository

    Wang, Lifeng

    2015-11-11

    The long-term slip on faults has to follow, on average, the plate motion, while slip deficit is accumulated over shorter time scales (e.g., between the large earthquakes). Accumulated slip deficits eventually have to be released by earthquakes and aseismic processes. In this study, we propose a new inversion approach for coseismic slip, taking interseismic slip deficit as prior information. We assume a linear correlation between coseismic slip and interseismic slip deficit, and invert for the coefficients that link the coseismic displacements to the required strain accumulation time and seismic release level of the earthquake. We apply our approach to the 2011 M9 Tohoku-Oki earthquake and the 2004 M6 Parkfield earthquake. Under the assumption that the largest slip almost fully releases the local strain (as indicated by borehole measurements, Lin et al., 2013), our results suggest that the strain accumulated along the Tohoku-Oki earthquake segment has been almost fully released during the 2011 M9 rupture. The remaining slip deficit can be attributed to the postseismic processes. Similar conclusions can be drawn for the 2004 M6 Parkfield earthquake. We also estimate the required time of strain accumulation for the 2004 M6 Parkfield earthquake to be ~25 years (confidence interval of [17, 43] years), consistent with the observed average recurrence time of ~22 years for M6 earthquakes in Parkfield. For the Tohoku-Oki earthquake, we estimate the recurrence time of~500-700 years. This new inversion approach for evaluating slip balance can be generally applied to any earthquake for which dense geodetic measurements are available.

  2. 'Shooting at the sun god Apollo': the Apollonian-Dionysian balance of the TimeSlips Storytelling Project.

    Science.gov (United States)

    George, Daniel R

    2013-09-01

    In The Birth of Tragedy, Friedrich Nietzsche celebrated the dueling forces of reason and emotion as personified by the ancient Greek gods Apollo and Dionysus. A subtle Apollonian-Dionysian balance can be observed in TimeSlips, a group-based creative storytelling activity developed in the 1990s and increasingly used in dementia care settings worldwide. This article explains how the Apollonion-Dionysian aspects of TimeSlips are beneficial not only for persons with dementia, but also for their carers. Narrative data from medical students at Penn State College of Medicine who participated in TimeSlips at a local retirement community are shared.

  3. Effects of 8 Weeks of Balance or Weight Training for the Independently Living Elderly on the Outcomes of Induced Slips

    Science.gov (United States)

    Kim, Sukwon; Lockhart, Thurmon

    2010-01-01

    The study was conducted to evaluate whether the balance or weight training could alter gait characteristics of elderly contributing to a reduction in the likelihood of slip-induced falls. A total of 18 elderly were evaluated for the study. The results indicated decreases in heel contact velocities and the friction demand characteristics after 8…

  4. Effects of 8 Weeks of Balance or Weight Training for the Independently Living Elderly on the Outcomes of Induced Slips

    Science.gov (United States)

    Kim, Sukwon; Lockhart, Thurmon

    2010-01-01

    The study was conducted to evaluate whether the balance or weight training could alter gait characteristics of elderly contributing to a reduction in the likelihood of slip-induced falls. A total of 18 elderly were evaluated for the study. The results indicated decreases in heel contact velocities and the friction demand characteristics after 8…

  5. Efficient simulation of gas-liquid pipe flows using a generalized population balance equation coupled with the algebraic slip model

    KAUST Repository

    Icardi, Matteo

    2014-09-01

    The inhomogeneous generalized population balance equation, which is discretized with the direct quadrature method of moment (DQMOM), is solved to predict the bubble size distribution (BSD) in a vertical pipe flow. The proposed model is compared with a more classical approach where bubbles are characterized with a constant mean size. The turbulent two-phase flow field, which is modeled using a Reynolds-Averaged Navier-Stokes equation approach, is assumed to be in local equilibrium, thus the relative gas and liquid (slip) velocities can be calculated with the algebraic slip model, thereby accounting for the drag, lift, and lubrication forces. The complex relationship between the bubble size distribution and the resulting forces is described accurately by the DQMOM. Each quadrature node and weight represents a class of bubbles with characteristic size and number density, which change dynamically in time and space to preserve the first moments of the BSD. The predictions obtained are validated against previously published experimental data, thereby demonstrating the advantages of this approach for large-scale systems as well as suggesting future extensions to long piping systems and more complex geometries. © 2014 Elsevier Inc.

  6. Stability against backward balance loss: Age-related modifications following slip-like perturbations of multiple amplitudes.

    Science.gov (United States)

    Martelli, Dario; Aprigliano, Federica; Tropea, Peppino; Pasquini, Guido; Micera, Silvestro; Monaco, Vito

    2017-03-01

    Falls are one of the most serious problems in the elderly. Although previous studies clearly link the increased risk of falls with ageing, the mechanisms responsible for the modifications of reactive motor behaviours in response to external perturbations are not yet fully understood. This study investigated how the stability against backward balance loss is affected by aging and intensity of perturbations. The Margin of Stability (MoS) was estimated while eight young and eight elderly adults managed three slip-like perturbations of different intensities while walking at the same normalized speed. A compensatory step was necessary to regain stability. The forward swing phase of the trailing leg was rapidly interrupted and reversed in direction. Results have shown that ageing significantly affects the time required to select the most appropriate biomechanical response: even if the characteristic of the backward step was similar between groups, elderly subjects took more time to reverse the movement of their swinging limb, thus achieving a less efficient action to counteract the backward balance loss (lower MoS both during and at the end of the early compensatory reaction). In addition, young and elderly subjects scaled their reactions with respect to the perturbations intensity in a similar way by increasing the length of their backward step, thus revealing a context-dependent tuning of the biomechanical response that was not affected by aging. These behavioural features can be helpful in identifying the causes of increased fall risk among the elderly in order to define more suited intervention in fall prevention programs.

  7. A delicate balance of magmatic-tectonic interaction at Kilauea Volcano, Hawai`i, revealed from slow slip events

    Science.gov (United States)

    Montgomery-Brown, Emily; Poland, Michael; Miklius, Asta

    2015-01-01

    Eleven slow slip events (SSEs) have occurred on the southern flank of Kilauea Volcano, Hawai’i, since 1997 through 2014. We analyze this series of SSEs in the context of Kilauea’s magma system to assess whether or not there are interactions between these tectonic events and eruptive/intrusive activity. Over time, SSEs have increased in magnitude and become more regular, with interevent times averaging 2.44 ± 0.15 years since 2003. Two notable SSEs that impacted both the flank and the magmatic system occurred in 2007, when an intrusion and small eruption on the East Rift Zone were part of a feedback with a SSE and 2012, when slow slip induced 2.5 cm of East Rift Zone opening (but without any change in eruptive activity). A summit inflation event and surge in East Rift Zone lava effusion was associated with a SSE in 2005, but the inferred triggering relation is not clear due to a poorly constrained slip onset time. Our results demonstrate that slow slip along Kilauea’s décollement has the potential to trigger and be triggered by activity within the volcano’s magma system. Since only three of the SSEs have been associated with changes in magmatic activity within the summit and rift zones, both the décollement and magma system must be close to failure for triggering to occur.

  8. Protein-losing enteropathy

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/007338.htm Protein-losing enteropathy To use the sharing features on this page, please enable JavaScript. Protein-losing enteropathy is an abnormal loss of protein ...

  9. 企业人力资源结构失衡现象略析%On Phenomenon of Losing Balance of Enterprises’ Human Resource Structure

    Institute of Scientific and Technical Information of China (English)

    耿锦卉

    2014-01-01

    The lost of balance of human resource in the enterprise is a kind of inherent economic phenom-enon, which includes the negative factors and positive factors .The lost of balance of human resource in enter-prise will influence the enterprise ’ s administrative system directly .We should take some effective actions on the lost of balance of enterprise ’ s administration .%企业人力资源结构失衡是一种固有的经济现象,既有消极影响,也有积极因素。企业人力资源结构失衡将直接影响企业管理系统的正常运行。企业应在失衡管理方面积极有所作为。

  10. Does aging with a cortical lesion increase fall-risk: Examining effect of age versus stroke on intensity modulation of reactive balance responses from slip-like perturbations.

    Science.gov (United States)

    Patel, Prakruti J; Bhatt, Tanvi

    2016-10-01

    We examined whether aging with and without a cerebral lesion such as stroke affects modulation of reactive balance response for recovery from increasing intensity of sudden slip-like stance perturbations. Ten young adults, older age-match adults and older chronic stroke survivors were exposed to three different levels of slip-like perturbations, level 1 (7.75m/s(2)), Level II (12.00m/s(2)) and level III (16.75m/s(2)) in stance. The center of mass (COM) state stability was computed as the shortest distance of the instantaneous COM position and velocity relative to base of support (BOS) from a theoretical threshold for backward loss of balance (BLOB). The COM position (XCOM/BOS) and velocity (ẊCOM/BOS) relative to BOS at compensatory step touchdown, compensatory step length and trunk angle at touchdown were also recorded. At liftoff, stability reduced with increasing perturbation intensity across all groups (main effect of intensity pintensity, such a trend was absent in other groups (intensity×group interaction, plevels II and III. Further, greater stability at touchdown positively correlated with anterior XCOM/BOS however not with ẊCOM/BOS. Young adults maintained anterior XCOM/BOS by increasing compensatory step length and preventing greater trunk extension at higher perturbation intensities. The age-match group attempted to increase step length from intensity I to II to maintain stability however could not further increase step length at intensity III, resulting in lower stability on this level compared with the young group. Stroke group on the other hand was unable to modulate compensatory step length or control trunk extension at higher perturbation intensities resulting in reduced stability on levels II and III compared with the other groups. The findings reflect impaired modulation of recovery response with increasing intensity of sudden perturbations among stroke survivors compared with their healthy counter parts. Thus, aging superimposed with a

  11. How to Lose Fat

    Institute of Scientific and Technical Information of China (English)

    A. Maxwell; 钱俊

    2005-01-01

    Here is yet another article about losing body fat. The Interact is riddled with such articles, Some propose complex diets; others give worth while valuable advice and most are trying to sell something.

  12. NIH Loses a Friend

    Science.gov (United States)

    ... page please turn Javascript on. NIH Loses a Friend Past Issues / Fall 2009 Table of Contents Donald ... changingthefaceofmedicine/ . Sincerely, Donald West King, M.D., Chairman Friends of the National Library of Medicine Let Us ...

  13. BALANCE

    Science.gov (United States)

    Carmichael, H.

    1953-01-01

    A torsional-type analytical balance designed to arrive at its equilibrium point more quickly than previous balances is described. In order to prevent external heat sources creating air currents inside the balance casing that would reiard the attainment of equilibrium conditions, a relatively thick casing shaped as an inverted U is placed over the load support arms and the balance beam. This casing is of a metal of good thernnal conductivity characteristics, such as copper or aluminum, in order that heat applied to one portion of the balance is quickly conducted to all other sensitive areas, thus effectively preventing the fornnation of air currents caused by unequal heating of the balance.

  14. Role of Gastrointestinal Hormones in Energy Balance Regulatory System and Weight-losing through Exercise%胃肠激素在能量平衡调节系统及运动减肥中的作用

    Institute of Scientific and Technical Information of China (English)

    李秋雨

    2016-01-01

    食物摄入的调节是多方面的,涵盖多种复杂机制,其中基于负反馈机制的内环境稳态调节系统是其中不可缺少的一部分。在内环境稳态调节系统中,由胃肠道分泌的外周激素发挥了重要作用,我们统称其为胃肠激素。胃肠激素是营养和能量摄入情况反馈到内分泌细胞后分泌的肽类物质,直接或通过迷走神经与脑联系。胃肠激素对于调节营养摄入和能量消耗过程的平衡、维持体重的相对稳定具有重要意义。本文概述了胃肠激素在调节食欲和摄食行为以及运动减肥中发挥的作用。%Regulation of food intake is multifaceted and covers a variety of complex mechanisms.Among them, system of homeostasis which based on negative feedback mechanisms is an indispensible part.In the regulation system of homeostasis,peripheral hormones which secreted from the gastrointestinal tract plays an important role and are called gastrointestinal hormones.Gastrointestinal hormones are peptide materials secreted from enteroendocrine cells after the feedback of nutrient and energy intake,and will communicate with the brain directly or via the vagus nerve.These hormones are crucial for balancing the process of food intake and energy expenditure and maintaining a relatively stable body weight.The paper provides an overview of the role of gastrointestinal hormone in regulating appetite,food intake and weight -losing through exercise.

  15. Slip resistance of non-slip socks--an accelerometer-based approach.

    Science.gov (United States)

    Hübscher, Markus; Thiel, Christian; Schmidt, Jens; Bach, Matthias; Banzer, Winfried; Vogt, Lutz

    2011-04-01

    The present study investigated the relative slip resistance of commercially available non-slip socks during gait. Twenty-four healthy subjects (29.3±10.4 years) participated in the study. Each subject completed 4 different test conditions (barefoot, non-slip socks, conventional socks, backless slippers) in a randomized, balanced order. The slip resistance was estimated by measuring the heel deceleration time using a heel-mounted accelerometer. Repeated measures ANOVA and post hoc paired-sample t-test with Bonferroni correction were used for statistical analysis. Compared to barefoot walking absolute deceleration times [ms] were significantly increased when wearing conventional socks or slippers. No significant differences were observed between the barefoot and non-slip socks conditions. The present study shows that non-slip socks improved slip-resistance during gait when compared to conventional socks and slippers. Future investigations should verify the present findings in hospital populations prone to slip-related falls.

  16. Antidepressants: Can They Lose Effectiveness?

    Science.gov (United States)

    ... be having the same effect. Can antidepressants lose effectiveness? Answers from Daniel K. Hall-Flavin, M.D. ... Policy Notice of Privacy Practices Notice of Nondiscrimination Advertising Mayo Clinic is a not-for-profit organization ...

  17. Falls study: Proprioception, postural stability, and slips.

    Science.gov (United States)

    Sohn, Jeehoon; Kim, Sukwon

    2015-01-01

    The present study evaluated effects of exercise training on the proprioception sensitivity, postural stability, and the likelihood of slip-induced falls. Eighteen older adults (6 in balance, 6 in weight, and 6 in control groups) participated in this study. Three groups met three times per week over the course of eight weeks. Ankle and knee proprioception sensitivities and postural stability were measured. Slip-induced events were introduced for all participants before and after training. The results indicated that, overall, strength and postural stability were improved only in the training group, although proprioception sensitivity was improved in all groups. Training for older adults resulted in decreased likelihood of slip-induced falls. The study suggested that proprioception can be improved by simply being active, however, the results suggested that training would aid older adults in reducing the likelihood of slip-induced falls.

  18. Are non-slip socks really 'non-slip'? An analysis of slip resistance

    OpenAIRE

    Haines Terrence; Chari Satyan; Varghese Paul; Economidis Alyssia

    2009-01-01

    Abstract Background Non-slip socks have been suggested as a means of preventing accidental falls due to slips. This study compared the relative slip resistance of commercially available non-slip socks with other foot conditions, namely bare feet, compression stockings and conventional socks, in order to determine any traction benefit. Methods Phase one involved slip resistance testing of two commercially available non-slip socks and one compression-stocking sample through an independent blind...

  19. Hydrodynamics of slip wedge and optimization of surface slip property

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The hydrodynamic load support generated by a slip wedge of a slider bearing was studied. The surface slip property was optimized so that a maximum hydrodynamic load support could be obtained. A multi-linearity method was given for the slip control equation of two-dimensional (2-D) wall slip. We investigated 2-D wall slip and the hydrodynamics of a finite length bearing with any values of the surface limiting shear stress. It was found that the hydrodynamic effect of the slip wedge is greater than the traditional geometrical convergent-wedge. Even though the geo- metrical gap is a parallel or divergent sliding gap, the slip wedge still gives rise to a very big hydrodynamic pressure. The optimized slip wedge can give rise to a hy- drodynamic load support as high as 2.5 times of what the geometrical conver- gent-wedge can produce. Wall slip usually gives a small surface friction.

  20. Hydrodynamics of slip wedge and optimization of surface slip property

    Institute of Scientific and Technical Information of China (English)

    MA GuoJun; WU ChengWei; ZHOU Ping

    2007-01-01

    The hydrodynamic load support generated by a slip wedge of a slider bearing was studied. The surface slip property was optimized so that a maximum hydrodynamic load support could be obtained. A multi-linearity method was given for the slip control equation of two-dimensional (2-D) wall slip. We investigated 2-D wall slip and the hydrodynamics of a finite length bearing with any values of the surface limiting shear stress. It was found that the hydrodynamic effect of the slip wedge is greater than the traditional geometrical convergent-wedge. Even though the geometrical gap is a parallel or divergent sliding gap, the slip wedge still gives rise to a very big hydrodynamic pressure. The optimized slip wedge can give rise to a hydrodynamic load support as high as 2.5 times of what the geometrical convergent-wedge can produce. Wall slip usually gives a small surface friction.

  1. Tensorial hydrodynamic slip

    CERN Document Server

    Bazant, Martin Z

    2008-01-01

    We describe a tensorial generalization of the Navier slip boundary condition and illustrate its use in solving for flows around anisotropic textured surfaces. Tensorial slip can be derived from molecular or microstructural theories or simply postulated as an constitutive relation, subject to certain general constraints on the interfacial mobility. The power of the tensor formalism is to capture complicated effects of surface anisotropy, while preserving a simple fluid domain. This is demonstrated by exact solutions for laminar shear flow and pressure-driven flow between parallel plates of arbitrary and different textures. From such solutions, the effects of rotating a texture follow from simple matrix algebra. Our results may be useful to extracting local slip tensors from global measurements, such as the permeability of a textured channel or the force required to move a patterned surface, in experiments or simulations.

  2. Medical Mystery: Losing the sense of smell

    Science.gov (United States)

    ... Hearing Disorders Medical Mystery: Losing the sense of smell Past Issues / Fall 2008 Table of Contents For ... a teenager that took away her sense of smell. Photo courtesy of Malone University Imagine, if you ...

  3. The Medicaid Medically Improved Group, Losing Disability...

    Data.gov (United States)

    U.S. Department of Health & Human Services — According to findings reported in, The Medicaid Medically Improved Group, Losing Disability Status and Growing Earnings, published in Volume 4, Issue 1 of the...

  4. What It Takes to Lose Weight

    Science.gov (United States)

    ... Limit time spent online, watching TV, and playing video games to less than two hours total per day. ... Tags: diet, losing weight, nutrition, obesity, overweight, patient education, patient information, weight, weight control, weight-loss programs ...

  5. The Medicaid Medically Improved Group, Losing Disability...

    Data.gov (United States)

    U.S. Department of Health & Human Services — According to findings reported in, The Medicaid Medically Improved Group, Losing Disability Status and Growing Earnings, published in Volume 4, Issue 1 of the...

  6. Reflections on reducing insulin to lose weigh.

    Science.gov (United States)

    Wilson, Val

    Diabulimia is not a recognised medical condition, although it is thought to affect one-third of women with type 1 diabetes. Diabulimia involves deliberately omitting or reducing insulin dosages to lose weight. This article reports the reflections of women with long-duration type 1 diabetes who said that they had manipulated their insulin in the past to lose weight. Many were now dealing with serious heart and neuropathic complications, which they felt were a result of their diabulimia.

  7. Slip flow in graphene nanochannels

    Science.gov (United States)

    Kannam, Sridhar Kumar; Todd, B. D.; Hansen, J. S.; Daivis, Peter J.

    2011-10-01

    We investigate the hydrodynamic boundary condition for simple nanofluidic systems such as argon and methane flowing in graphene nanochannels using equilibrium molecular dynamics simulations (EMD) in conjunction with our recently proposed method [J. S. Hansen, B. D. Todd, and P. J. Daivis, Phys. Rev. E 84, 016313 (2011), 10.1103/PhysRevE.84.016313]. We first calculate the fluid-graphene interfacial friction coefficient, from which we can predict the slip length and the average velocity of the first fluid layer close to the wall (referred to as the slip velocity). Using direct nonequilibrium molecular dynamics simulations (NEMD) we then calculate the slip length and slip velocity from the streaming velocity profiles in Poiseuille and Couette flows. The slip lengths and slip velocities from the NEMD simulations are found to be in excellent agreement with our EMD predictions. Our EMD method therefore enables one to directly calculate this intrinsic friction coefficient between fluid and solid and the slip length for a given fluid and solid, which is otherwise tedious to calculate using direct NEMD simulations at low pressure gradients or shear rates. The advantages of the EMD method over the NEMD method to calculate the slip lengths/flow rates for nanofluidic systems are discussed, and we finally examine the dynamic behaviour of slip due to an externally applied field and shear rate.

  8. On k-hypertournament losing scores

    CERN Document Server

    Pirzada, Shariefuddin

    2010-01-01

    We give a new and short proof of a theorem on k-hypertournament losing scores due to Zhou et al. [G. Zhou, T. Yao, K. Zhang, On score sequences of k-tournaments, European J. Comb., 21, 8 (2000) 993-1000.

  9. "Losing Battles": The Tests of Endurance.

    Science.gov (United States)

    Rienstra, Phillis

    The works of Eudora Welty challenge the abilities of the oral reader who wishes to interpret them properly. Her novel, "Losing Battles," requires careful attention to the narrative point of view as a guide to its various dimensions of meaning. The narrative shifts through the consciousnesses of various characters of four generations in a rural…

  10. Are non-slip socks really 'non-slip'? An analysis of slip resistance

    Directory of Open Access Journals (Sweden)

    Haines Terrence

    2009-08-01

    Full Text Available Abstract Background Non-slip socks have been suggested as a means of preventing accidental falls due to slips. This study compared the relative slip resistance of commercially available non-slip socks with other foot conditions, namely bare feet, compression stockings and conventional socks, in order to determine any traction benefit. Methods Phase one involved slip resistance testing of two commercially available non-slip socks and one compression-stocking sample through an independent blinded materials testing laboratory using a Wet Pendulum Test. Phase two of the study involved in-situ testing among healthy adult subjects (n = 3. Subjects stood unsupported on a variable angle, inclined platform topped with hospital grade vinyl, in a range of foot conditions (bare feet, non-slip socks, conventional socks and compression stockings. Inclination was increased incrementally for each condition until slippage of any magnitude was detected. The platform angle was monitored using a spatial orientation tracking sensor and slippage point was recorded on video. Results Phase one results generated through Wet Pendulum Test suggested that non-slip socks did not offer better traction than compression stockings. However, in phase two, slippage in compression stockings was detected at the lowest angles across all participants. Amongst the foot conditions tested, barefoot conditions produced the highest slip angles for all participants indicating that this foot condition provided the highest slip resistance. Conclusion It is evident that bare feet provide better slip resistance than non-slip socks and therefore might represent a safer foot condition. This study did not explore whether traction provided by bare feet was comparable to 'optimal' footwear such as shoes. However, previous studies have associated barefoot mobilisation with increased falls. Therefore, it is suggested that all patients continue to be encouraged to mobilise in appropriate, well

  11. Handling a slip | Smokefree 60+

    Science.gov (United States)

    Plan how you will recover from a slip—before it happens. You can recover from a slip If you do go back to smoking, you are not a failure. Don't toss aside your attempt as worthless. Use it to try and succeed. Think of your quit attempt as a learning experience, and if you do slip, try again.

  12. Losing Items in the Psychogeriatric Nursing Home

    Directory of Open Access Journals (Sweden)

    J. van Hoof PhD

    2016-09-01

    Full Text Available Introduction: Losing items is a time-consuming occurrence in nursing homes that is ill described. An explorative study was conducted to investigate which items got lost by nursing home residents, and how this affects the residents and family caregivers. Method: Semi-structured interviews and card sorting tasks were conducted with 12 residents with early-stage dementia and 12 family caregivers. Thematic analysis was applied to the outcomes of the sessions. Results: The participants stated that numerous personal items and assistive devices get lost in the nursing home environment, which had various emotional, practical, and financial implications. Significant amounts of time are spent on trying to find items, varying from 1 hr up to a couple of weeks. Numerous potential solutions were identified by the interviewees. Discussion: Losing items often goes together with limitations to the participation of residents. Many family caregivers are reluctant to replace lost items, as these items may get lost again.

  13. Optimization of non-contrast-enhanced MR angiography of the renal artery with three-dimensional balanced steady-state free-precession and time-spatial labeling inversion pulse (time-SLIP) at 3T MRI, in relation to age and blood velocity.

    Science.gov (United States)

    Kurata, Yasuhisa; Kido, Aki; Fujimoto, Koji; Kiguchi, Kayo; Takakura, Kyoko; Moribata, Yusaku; Shitano, Fuki; Himoto, Yuki; Fushimi, Yasutaka; Okada, Tomohisa; Togashi, Kaori

    2016-01-01

    To determine the optimal inversion time (TI) value of three-dimensional (3D) balanced steady-state free-precession time-spatial labeling inversion pulse (time-SLIP) technique for visualization of the renal artery at 3T MRI, and to assess whether the optimal TI is affected by the subject's age and blood velocity. Forty-two healthy volunteers (range 20-67 years) were enrolled in the study and subjected to non-contrast-enhanced renal MR angiography. Five different TI values (1200, 1400, 1600, 1800, and 2000 ms) were selected for evaluation. For quantitative evaluation, the relative signal intensity (SI) of the main renal artery was compared with that of the renal medulla (Vessel-to-Kidney ratio; VKR). Blood velocity of the abdominal aorta was measured using 2D phase contrast technique. For qualitative evaluation, two radiologists scored the depiction of the renal pelvis and the quality of visualization of the renal artery. VKR is the highest at TI = 1600 ms. A strong negative correlation between age and blood velocity was demonstrated. Regarding the qualitative evaluation, the overall image scores of renal arteries were the highest at a TI = 1800 ms for both readers. The optimal TI values in subjects below 50 years of age were 1600 and 1800 ms, whereas in subjects above 50 years of age, the optimal TI value was 1800 ms. The optimal TI value for the visualization of renal arteries using time-SLIP technique at 3T MRI was 1800 ms. Subjects' age affected optimal TI and this is likely due to differences in the blood velocity of the abdominal aorta.

  14. Foods That Help You Lose Weight

    Institute of Scientific and Technical Information of China (English)

    刘伟业

    1995-01-01

    "There are no magic foods," says Kelly Streit,health-education instructor at Kaiser Permanente Medical Care Program in Portland,Ore. "But there are foods that, because of their taste, texture or density, can help you lose weight. " That’s the idea behind the following foods, which trick your body into feeling satisfied with far less fat and fewer calories than it’s used to.

  15. The "Biggest Loser" Expounds on the Benefits of Losing Pounds

    Science.gov (United States)

    ... Bar Home Current Issue Past Issues Special Section The "Biggest Loser" Expounds on the Benefits of Losing Pounds Past Issues / Winter 2008 ... 186 pounds, going from 361 to 175 pounds. The Twins on Losing Weight Bill: "The only way ...

  16. Shock slip-relations for thermal and chemical nonequilibrium flows

    Science.gov (United States)

    Jinrong, Tang

    1996-05-01

    This paper appears to be the first where the multi-temperature shock slip-relations for the thermal and chemical nonequilibrium flows are derived. The derivation is based on analysis of the influences of thermal nonequilibrium and viscous effects on the mass, momentum and emergy flux balance relations at the shock wave. When the relaxation times for all internal energy modes tend to zero, the multi-tmperature shock slip-relations are converted into single-temperature ones for thermal equilibrium flows. The present results can be applied to flow over vehicles of different geometries with or without angles of attack. In addition, the present single-temperature shock slip-relations are compared with those in the literature, and some defects and limitations in the latter are clarified.

  17. Slips of the Typewriter Key.

    Science.gov (United States)

    Berg, Thomas

    2002-01-01

    Presents an analysis of 500 submorphemic slips of the typewriter key that escaped the notice of authors and other proofreaders and thereby made their way into the published records of scientific research. (Author/VWL)

  18. Protein-losing enteropathies in dogs.

    Science.gov (United States)

    Dossin, Olivier; Lavoué, Rachel

    2011-03-01

    Protein-losing enteropathy is common in dogs but rare in cats. In the vast majority of cases, it is associated with inflammatory bowel disease, intestinal lymphoma, or intestinal lymphangiectasia. The diagnosis is based on identification of hypoalbuminemia and ruling out urinary loss and liver failure. Identification of the intestinal lesion with appropriate biopsy method is important to rule out neoplasm or infectious causes. The treatment is based on intensive nutritional support, therapy for the causative condition, and early monitoring of possibly life-threatening complications, such as hypocobalaminemia, massive pleural or abdominal fluid collection, thromboembolism, and hypocalcemia or hypomagnesemia.

  19. The effect of losing the twin and losing the partner on mortality

    DEFF Research Database (Denmark)

    Tomassini, Cecilia; Rosina, Alessandro; Billari, Francesco C

    2002-01-01

    Several studies have explored the impact of marital bereavement on mortality, while increasing emphasis has recently been placed on genetic factors influencing longevity - in this paper, we study the impact of losing the spouse and losing the co-twin, for twins aged 50 to 70. We use data from...... is similar for men and women, and it is higher for monozygotic twins. The latter confirms the influence of genetic factors on survival, while the mortality trajectory with a peak in the second year after the death of the co-twin is consistent with the existence of a twin bereavement effect....

  20. Land-losing Farmers’ Citizenization in the Process of Urbanization

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    Starting from the status of citizenization of land-losing farmers,problems in the citizenization are analyzed,such as the difficulty in land-losing farmers’ economic life after turning into citizens,employment difficulties of land-losing farmers after living in the city,and the prominent problems in social security of land-losing farmers.Causations for the citizenization problems of land-losing farmers are analyzed.Firstly,institutionalized rejection is the root of the obstacle in citizenization of land-losing farmers.Secondly,exclusion from social security system is a fundamental reason.Thirdly,exclusion of land-losing farmers from both urban citizens and themselves is the subjective factor.Fourthly,exclusion of land-losing farmers from urban employment is the objective factor.Based on these,countermeasures are put forward:formulating a reasonable price of land transfer;establishing a reasonable land compensation and benefit-sharing mechanism;setting up a multi-level social security system for land-losing farmers;increasing the human capital investment in land-losing farmers to enhance their employment status;and improving the cultural quality of land-losing farmers to realize the change in lifestyle.

  1. Misinformed leaders lose influence over pigeon flocks.

    Science.gov (United States)

    Watts, Isobel; Nagy, Máté; Burt de Perera, Theresa; Biro, Dora

    2016-09-01

    In animal groups where certain individuals have disproportionate influence over collective decisions, the whole group's performance may suffer if these individuals possess inaccurate information. Whether in such situations leaders can be replaced in their roles by better-informed group mates represents an important question in understanding the adaptive consequences of collective decision-making. Here, we use a clock-shifting procedure to predictably manipulate the directional error in navigational information possessed by established leaders within hierarchically structured flocks of homing pigeons (Columba livia). We demonstrate that in the majority of cases when leaders hold inaccurate information they lose their influence over the flock. In these cases, inaccurate information is filtered out through the rearrangement of hierarchical positions, preventing errors by former leaders from propagating down the hierarchy. Our study demonstrates that flexible decision-making structures can be valuable in situations where 'bad' information is introduced by otherwise influential individuals.

  2. Slipping rib syndrome in childhood.

    Science.gov (United States)

    Mooney, D P; Shorter, N A

    1997-07-01

    Slipping rib syndrome is an unusual cause of lower chest and upper abdominal pain in children not mentioned in major pediatric surgical texts. The syndrome occurs when the medial fibrous attachments of the eighth, ninth, or tenth ribs are inadequate or ruptured, allowing their cartilage tip to slip superiorly and impinge on the intervening intercostal nerve. This may cause a variety of somatic and visceral complaints. Although the diagnosis may be made based on history and physical examination, lack of recognition of this disorder frequently leads to extensive diagnostic evaluations before definitive therapy. The authors report on four children who have this disorder.

  3. Slip flow in graphene nanochannels

    DEFF Research Database (Denmark)

    . Kannam, Sridhar; Billy, Todd; Hansen, Jesper Schmidt

    2011-01-01

    We investigate the hydrodynamic boundary condition for simple nanofluidic systems such as argon and methane flowing in graphene nanochannels using equilibrium molecular dynamics simulations (EMD) in conjunction with our recently proposed method [J. S. Hansen, B. D. Todd, and P. J. Daivis, Phys. Rev....... E 84, 016313 (2011)10.1103/PhysRevE.84.016313]. We first calculate the fluid-graphene interfacial friction coefficient, from which we can predict the slip length and the average velocity of the first fluid layer close to the wall (referred to as the slip velocity). Using direct nonequilibrium...

  4. Whillans Ice Plain Stick Slip

    Science.gov (United States)

    Lipovsky, B.; Dunham, E. M.

    2015-12-01

    Concern about future sea level rise motivates the study of fast flowing ice. The Whillans Ice Plain (WIP) region of the West Antarctic Ice Sheet is notable for decelerating from previously fast motion during the instrumental record. Since most ice flux in Antarctica occurs through ice streams, understanding the conditions that cause ice stream stagnation is of basic importance in understanding the continent's contribution to future sea level rise. Although recent progress has been made in understanding the relationship between basal conditions and ice stream motion, direct observation of the temporal variation in subglacial conditions during ice stream stagnation has remained elusive. The Whillans Ice Plain flows to the sea mostly by way of stick-slip motion. We present numerical simulations of this stick-slip motion that capture the inertial dynamics, seismic waves, and the evolution of sliding with rate- and state-dependent basal friction. Large scale stick-slip behavior is tidally modulated and encompasses the entire WIP. Sliding initiates within one of several locked regions and then propagates outward with low average rupture velocity (~ 200 m/s). Sliding accelerates over a period of 200 s attain values as large as 65 m/d. From Newton's second law, this acceleration is ~ T / (rho H) for average shear stress drop T, ice thickness H, and ice density rho. This implies a 3 Pa stress drop that must be reconciled with the final stress drop of 300 Pa inferred from the total slip and fault dimensions. A possible explanation of this apparent discrepancy is that deceleration of the ice is associated with a substantial decrease in traction within rate-strengthening regions of the bed. During these large-scale sliding events, m-scale patches at the bed produce rapid (20 Hz) stick-slip motion. Each small event occurs over ~ 1/100 s, produces ~ 40 microns of slip, and gives rise to a spectacular form of seismic tremor. Variation between successive tremor episodes allows us

  5. The effect of losing the twin and losing the partner on mortality

    DEFF Research Database (Denmark)

    Tomassini, Cecilia; Rosina, Alessandro; Billari, Francesco C;

    2002-01-01

    Several studies have explored the impact of marital bereavement on mortality, while increasing emphasis has recently been placed on genetic factors influencing longevity - in this paper, we study the impact of losing the spouse and losing the co-twin, for twins aged 50 to 70. We use data from...... the Danish Twin Registry and the Population Register of Denmark for the period 1968 through 1999. Firstly, we use survival analysis to study mortality after the death of the spouse or the co-twin. We find that the risk of dying is highest in the first year after the death of the spouse, as well...... as in the second year after the death of the co-twin. We then use event history analysis techniques to show that there is a strong impact of the event 'losing the co-twin' even after controlling for age, sex and zygosity and that this effect is significantly higher in the second year of bereavement. The effect...

  6. On the question of whether lubricants fluidize in stick-slip friction.

    Science.gov (United States)

    Rosenhek-Goldian, Irit; Kampf, Nir; Yeredor, Arie; Klein, Jacob

    2015-06-09

    Intermittent sliding (stick-slip motion) between solids is commonplace (e.g., squeaking hinges), even in the presence of lubricants, and is believed to occur by shear-induced fluidization of the lubricant film (slip), followed by its resolidification (stick). Using a surface force balance, we measure how the thickness of molecularly thin, model lubricant films (octamethylcyclotetrasiloxane) varies in stick-slip sliding between atomically smooth surfaces during the fleeting (ca. 20 ms) individual slip events. Shear fluidization of a film of five to six molecular layers during an individual slip event should result in film dilation of 0.4-0.5 nm, but our results show that, within our resolution of ca. 0.1 nm, slip of the surfaces is not correlated with any dilation of the intersurface gap. This reveals that, unlike what is commonly supposed, slip does not occur by such shear melting, and indicates that other mechanisms, such as intralayer slip within the lubricant film, or at its interface with the confining surfaces, may be the dominant dissipation modes.

  7. Hydrodynamic slip in silicon nanochannels

    Science.gov (United States)

    Ramos-Alvarado, Bladimir; Kumar, Satish; Peterson, G. P.

    2016-03-01

    Equilibrium and nonequilibrium molecular dynamics simulations were performed to better understand the hydrodynamic behavior of water flowing through silicon nanochannels. The water-silicon interaction potential was calibrated by means of size-independent molecular dynamics simulations of silicon wettability. The wettability of silicon was found to be dependent on the strength of the water-silicon interaction and the structure of the underlying surface. As a result, the anisotropy was found to be an important factor in the wettability of these types of crystalline solids. Using this premise as a fundamental starting point, the hydrodynamic slip in nanoconfined water was characterized using both equilibrium and nonequilibrium calculations of the slip length under low shear rate operating conditions. As was the case for the wettability analysis, the hydrodynamic slip was found to be dependent on the wetted solid surface atomic structure. Additionally, the interfacial water liquid structure was the most significant parameter to describe the hydrodynamic boundary condition. The calibration of the water-silicon interaction potential performed by matching the experimental contact angle of silicon led to the verification of the no-slip condition, experimentally reported for silicon nanochannels at low shear rates.

  8. Slip rate and tremor genesis in Cascadia

    Science.gov (United States)

    Wech, Aaron G.; Bartlow, Noel M.

    2014-01-01

    At many plate boundaries, conditions in the transition zone between seismogenic and stable slip produce slow earthquakes. In the Cascadia subduction zone, these events are consistently observed as slow, aseismic slip on the plate interface accompanied by persistent tectonic tremor. However, not all slow slip at other plate boundaries coincides spatially and temporally with tremor, leaving the physics of tremor genesis poorly understood. Here we analyze seismic, geodetic, and strainmeter data in Cascadia to observe for the first time a large, tremor-generating slow earthquake change from tremor-genic to silent and back again. The tremor falls silent at reduced slip speeds when the migrating slip front pauses as it loads the stronger adjacent fault segment to failure. The finding suggests that rheology and slip-speed-regulated stressing rate control tremor genesis, and the same section of fault can slip both with and without detectable tremor, limiting tremor's use as a proxy for slip.

  9. Slipping properties of ceramic tiles / Quantification of slip resistance

    Science.gov (United States)

    Terjek, Anita

    2013-12-01

    Regarding the research and application of ceramic tiles there is a great importance of defining precisely the interaction and friction between surfaces. Measuring slip resistance of floor coverings is a complex problem; slipperiness is always interpreted relatively. In the lack of a consistent and clear EU standard, it is practical to use more method in combination. It is necessary to examine the structure of materials in order to get adequate correlation. That is why measuring techniques of surface roughness, an important contributor to slip resistance and cleaning, is fundamental in the research. By comparing the obtained test results, relationship between individual methods of analysis and values may be determined and based on these information recommendations shall be prepared concerning the selection and application of tiles.

  10. Research on the Urban Integration of Land-losing Farmers

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    Fishbone chart is used to analyze the status of the living ability of land-losing farmers, as well as its causation from the aspects of system layer, social support network, land-losing farmer themselves, and economic layer. Result shows that the system layer includes the unreasonable land compensation, the lack of social security for land-losing farmers, and the employment exclusion of land-losing farmers. Small scale and low heterogeneity are the causations for social support network. Low willingness to become citizens, low cultural quality and difficulty in role change are the causations of land-losing farmers themselves. The low expected return and high living cost are the causations for economic layer. Based on the above analysis, countermeasures to improve the urban-living ability of land-losing farmers are put forward, such as improving the land expropriation system, establishing a multi-level social security system, enhancing the training and employment mechanism of land-losing farmers, and improving the quality of land-losing farmers.

  11. [Gait analysis of adults' slips and falls based on COM equilibrium recovery response].

    Science.gov (United States)

    Su, Hailong; Zhang, Dawei; Li, Jia

    2012-02-01

    Aiming at slips and falls occurred during adults' walking, a method was proposed that could predict slips and falls based on center of mass (COM) recovery response. This method, based on the Kane's equation dynamic walking model of the lower extremities, can be used to rapidly detect dynamic parameters in each gait cycle, and analyze any instantaneous balance status of slips and falls, and the characteristic COM curves may be accomplished on the basis of the measurement data. Moreover, causations, phases and processes about gaits of adults' slips and falls could be judged and analyzed by the characteristic curves. When the distance between the projection point of COM to base of support (BOS) domain is more than 0.012-0. 015m, human gaits have a tendency to slip and fall. When COM velocity response curve value is between 0.9-2. 1m/s, human gaits are normal and stable. The experimental results of slips and falls about the two different age groups showed that the method is able to predict and revise slips and falls by the COM recovery response characteristic curves.

  12. Vegetarian Diet: Will It Help Me Lose Weight?

    Science.gov (United States)

    ... Lifestyle Weight loss If I switch to a vegetarian diet, will I lose weight? Answers from Katherine Zeratsky, R.D., L.D. Not necessarily. A vegetarian diet is not inherently a weight-loss diet, ...

  13. Diabetic Foot and Risk: How to Prevent Losing Your Leg

    Science.gov (United States)

    ... Site Content AOFAS / FootCareMD / Conditions / Diabetic Foot The Diabetic Foot and Risk: How to Prevent Losing Your ... Page Content Don't deny you are a diabetic Anyone who has ever had an elevated blood ...

  14. Hydrography - MO 2014 Losing and Gaining Stream Segments (SHP)

    Data.gov (United States)

    NSGIC State | GIS Inventory — This data set depicts stream segments classified as either losing or gaining by the Missouri Department of Natural Resources (DNR), Missouri Geological Survey (MGS)....

  15. Phase slips in superconducting weak links

    Energy Technology Data Exchange (ETDEWEB)

    Kimmel, Gregory; Glatz, Andreas; Aranson, Igor S.

    2017-01-01

    Superconducting vortices and phase slips are primary mechanisms of dissipation in superconducting, superfluid, and cold-atom systems. While the dynamics of vortices is fairly well described, phase slips occurring in quasi-one- dimensional superconducting wires still elude understanding. The main reason is that phase slips are strongly nonlinear time-dependent phenomena that cannot be cast in terms of small perturbations of the superconducting state. Here we study phase slips occurring in superconducting weak links. Thanks to partial suppression of superconductivity in weak links, we employ a weakly nonlinear approximation for dynamic phase slips. This approximation is not valid for homogeneous superconducting wires and slabs. Using the numerical solution of the time-dependent Ginzburg-Landau equation and bifurcation analysis of stationary solutions, we show that the onset of phase slips occurs via an infinite period bifurcation, which is manifested in a specific voltage-current dependence. Our analytical results are in good agreement with simulations.

  16. Revision of the new formula for book losing rate

    Institute of Scientific and Technical Information of China (English)

    TANG Zhen-yu; GENG Xiao-bing

    2005-01-01

    While the amount of book borrowing is overlooked in the calculation of book losing rate in a closed system, there are also other important overlooked elements, factors such as reader groups and the reading timetable in open book stacks. On the basis of concrete evidence, this paper revised a new formula for book losing rate with the purpose of making the estimation in management more objective and more accurate.

  17. Losing Traction and the Art of Slip-Sliding Away: Or, Getting over Education for Sustainable Development

    Science.gov (United States)

    Jickling, Bob

    2016-01-01

    This response problematizes Stefan Bengtsson's (2016) defense of education for sustainable development. He argues that sustainable development and education for sustainable development are not globalizing and hegemonic discourses, as some have claimed, and uses case-study analysis of Vietnamese policy documents to support his claims. He observes…

  18. Losing Traction and the Art of Slip-Sliding Away: Or, Getting over Education for Sustainable Development

    Science.gov (United States)

    Jickling, Bob

    2016-01-01

    This response problematizes Stefan Bengtsson's (2016) defense of education for sustainable development. He argues that sustainable development and education for sustainable development are not globalizing and hegemonic discourses, as some have claimed, and uses case-study analysis of Vietnamese policy documents to support his claims. He observes…

  19. Learning to predict slip for ground robots

    Science.gov (United States)

    Angelova, Anelia; Matthies, Larry; Helmick, Daniel; Sibley, Gabe; Perona, Pietro

    2006-01-01

    In this paper we predict the amount of slip an exploration rover would experience using stereo imagery by learning from previous examples of traversing similar terrain. To do that, the information of terrain appearance and geometry regarding some location is correlated to the slip measured by the rover while this location is being traversed. This relationship is learned from previous experience, so slip can be predicted later at a distance from visual information only.

  20. Slip resistance testing - Zones of uncertainty

    Energy Technology Data Exchange (ETDEWEB)

    Bowman, R.

    2010-07-01

    This paper considers recent and current potential developments in the international standardisation of slip resistance. It identifies some limitations of the wet barefoot ramp test, such that changes should be made if it is to be more widely used. It also identifies some limitations of the new European SlipSTD Publicly Available Specification, such as insufficient allowance for the deterioration of slip resistance as tiles inevitably wear. (Author) 22 refs.

  1. Large Slip Length over a Nanopatterned Surface

    Institute of Scientific and Technical Information of China (English)

    LI Ding; DI Qin-Feng; LI Jing-Yuan; QIAN Yue-Hong; FANG Hai-Ping

    2007-01-01

    A thermodynamic method is employed to analyse the slip length of hydrophobic nanopatterned surface.The maximal slip lengths with respect to the hydrophobicity of the nanopatterned surface are computed.It is found that the slip length reaches more than 50μm if the nanopatterned surfaces have a contact angle larger than 160°.Such results are expected to find extensive applications in micro-channels and helpful to understand recent experimental observations of the slippage of nanopatterned surfaces.

  2. Coseismic slip in the 2010 Yushu earthquake (China, constrained by wide-swath and strip-map InSAR

    Directory of Open Access Journals (Sweden)

    Y. Wen

    2013-01-01

    Full Text Available On 14 April 2010, an Mw = 6.9 earthquake occurred in the Yushu county of China, which caused ~3000 people to lose their lives. Integrated with the information from the observed surface ruptures and aftershock locations, the faulting pattern of this earthquake is derived from the descending wide-swath and ascending strip mode PALSAR data collected by ALOS satellite. We used a layered crustal model and stress drop smoothing constraint to infer the coseismic slip distribution. Our model suggests that the earthquake fault can be divided into four segments and the slip mainly occurs within the upper 12 km with a maximum slip of 2.0 m at depth of 3 km on the Jiegu segment. The rupture of the upper 12 km is dominated by left-lateral strike-slip motion. The relatively small slip along the SE region of Yushu segment suggests a slip deficit there. The inverted geodetic moment is approximately Mw = 6.9, consistent with the seismological results. The average stress drop caused by the earthquake is about 2 MPa with a maximum stress drop of 8.3 MPa. Furthermore, the calculated static Coulomb stress changes in surrounding regions show increased Coulomb stress occurred in the SE region along the Yushu segment but with less aftershock, indicating an increased seismic hazard in this region after the earthquake.

  3. Cycle slipping in phase synchronization systems

    Science.gov (United States)

    Yang, Ying; Huang, Lin

    2007-02-01

    Cycle slipping is a characteristically nonlinear phenomenon in phase synchronization systems, which is highly dependent of the initial state of the system. Slipping a cycle means that the phase error is increased to such an extent that the generator to be synchronized slips one complete cycle with respect to the input phase. In this Letter, a linear matrix inequality (LMI) based approach is proposed and the estimation of the number of cycles which slips a solution of the system is obtained by solving a quasi-convex optimization problem of LMI. Applications to phase locked loops demonstrate the validity of the proposed approach.

  4. Observation of slip flow in thermophoresis.

    Science.gov (United States)

    Weinert, Franz M; Braun, Dieter

    2008-10-17

    Two differing theories aim to describe fluidic thermophoresis, the movement of particles along a temperature gradient. While thermodynamic approaches rely on local equilibrium, hydrodynamic descriptions assume a quasi-slip-flow boundary condition at the particle's surface. Evidence for slip flow is presented for the case of thermal gradients exceeding (aS_(T)(-1) with particle radius a and Soret coefficient S_(T). Thermophoretic slip flow at spheres near a surface attracts or repels tracer particles perpendicular to the thermal gradient. Moreover, particles mutually attract and form colloidal crystals. Fluid dynamic slip explains the latter quantitatively.

  5. Balance Problems

    Science.gov (United States)

    ... you are having balance problems, see your doctor. Balance disorders can be signs of other health problems, such ... cases, treating the illness that is causing the disorder will help with the balance problem. Exercises, a change in diet, and some ...

  6. Adaptive thermogenesis can make a difference in the ability of obese individuals to lose body weight.

    Science.gov (United States)

    Tremblay, A; Royer, M-M; Chaput, J-P; Doucet, E

    2013-06-01

    The decrease in energy expenditure that occurs during weight loss is a process that attenuates over time the impact of a restrictive diet on energy balance up to a point beyond which no further weight loss seems to be possible. For some health professionals, such a diminished energy expenditure is the normal consequence of a progressive decrease in the motivation to exercise over the course of a weight-reducing program. Another explanation of decreased energy needs during weight loss is the decrease in body energy stores (that is, fat mass and muscle mass) and its related obligatory costs of living. Many studies have also documented the existence of adaptive thermogenesis in the context of weight loss, which represents a greater-than-predicted decrease in energy expenditure. In this paper, we pursue the analysis of this phenomenon by demonstrating that an adaptive decrease in thermogenesis can have a major role in the occurrence of resistance to further lose fat in weight-reduced obese individuals. Evidence is also presented to support the idea of greater hunger sensations in individuals displaying more pronounced thermogenic changes. Finally, as the decrease in thermogenesis persists over time, it is also likely associated with a greater predisposition to body-weight regain after weight loss. Globally, these observations suggest that the adaptive reduction in thermogenesis that accompanies a prolonged negative energy balance is a major determinant of the ability to spontaneously lose body fat.

  7. You Can't Reach for the Stars if You are Tripping Over the Ground! (Preventing Slips, Trips, and Falls)

    Science.gov (United States)

    Miller, Darcy; Raysich, Mark; Kirkland, Mary

    2016-01-01

    Although there are very few mishaps related to ground, vehicle or payload processing at the Kennedy Space Center (KSC), employees have experienced a significant number of injuries due to slips, trips, and falls outside of performing flight processing operations. Slips, trips, and falls are major causes of occupational injuries at KSC, the National Aeronautics and Space Administration (NASA), and in general industry. To help KSC employees avoid these injuries, and allow them to be fully productive, KSC launched an initiative in 2013 to reduce slips, trips, and falls. This initiative is based on a four-part model focusing on DATA analysis, HAZARD awareness, PREVENTIVE methods, and BALANCE.

  8. A Brief Analysis on Slips of Tongue

    Institute of Scientific and Technical Information of China (English)

    孟庆瑜

    2015-01-01

    The phenomenon of slips of tongue is very common in our daily life.And it is closely related to some psychological reasons.This paper aims to introduce the research about this phenomenon, to present the types of slips of tongue and some analysis on it.

  9. Slip versus Friction : Modifying the Navier condition

    Science.gov (United States)

    Kotsalis, Evangelos; Walther, Jens; Koumoutsakos, Petros

    2006-03-01

    The modeling of fluid-solid interfaces remains one of the key challenges in fluid mechanics. The prevailing model, attributed to Navier, defines the fluid ``slip'' velocity as proportional to the wall shear and a parameter defined as the slip length. Several works have in turn proposed models for this slip length but no universal model for the slip velocity has been accepted. We present results from large scale molecular dynamics simulations of canonical flow problems, indicating, that the inadequacy of this classic model, stems from not properly accounting for the pressure field. We propose and validate a new model, based on the fundamental observation that the finite ``slip'' velocity is a result of an imbalance between fluid and solid intermolecular forces. An excess force on the fluid elements will lead to their acceleration which in turn may result in a slip velocity at the interface. We formulate the slip velocity in terms of fluid-solid friction Ff and propose a generalized boundary condition: Ff= Fs+ Fp= λuus+ λpp where p denotes the pressure, and λuand λp the viscous and static friction coefficients, for which universal constants are presented. We demonstrate that the present model can overcome difficulties encountered by the classical slip model in canonical flow configurations.

  10. Microstructure and Slip Character in Titanium Alloys

    Directory of Open Access Journals (Sweden)

    D. Banerjee

    1986-04-01

    Full Text Available Influence of microstructures in titanium alloys on the basic parameters of deformation behaviour such as slip character, slip length and slip intensity have been explored. Commercial titanium alloys contain the hexagonal close packed (alpha and body centred cubic (bita phases. Slip in these individual phases is shown to be dependent on the nature of alloying elements through their effect on phase stability as related to decomposition into ordered or w structures. When alpha and bita coexist, their relative crystallographic orientations, size, shape and volume fraction, control the nature of slip. For a given composition, structure may be manipulated through appropriate thermomechanical treatment to obtain the desired deformation behaviour and therefore fracture mode.

  11. Living with clipped wings - patients’ experience of losing a leg

    DEFF Research Database (Denmark)

    Norlyk, Annelise; Martinsen, Bente; Kjaer-Petersen, Klaus

    2013-01-01

    This study explores the lived experience of losing a leg as described by the patients themselves post-discharge. Studies have documented that regardless of aetiology patients are faced with severe physical as well as psychosocial challenges post-amputation. However, only few studies explore in....... The essential meaning of losing a leg is a radical and existential upheaval, which restricts patients' lifestyle and irretrievably alters their lifeworld. Life after the operation is associated with despair, and a painful sense of loss, but also with the hope of regaining personal independence. The consequences...... of losing a leg gradually materialize as the patients realize how the loss of mobility limits their freedom. Patients experience the professional help as primarily directed towards physical care and rehabilitation. The findings show that the loss of a leg and, subsequently, the restricted mobility carry...

  12. Slow slip generated by dehydration reaction coupled with slip-induced dilatancy and thermal pressurization

    Science.gov (United States)

    Yamashita, Teruo; Schubnel, Alexandre

    2016-05-01

    Sustained slow slip, which is a distinctive feature of slow slip events (SSEs), is investigated theoretically, assuming a fault embedded within a fluid-saturated 1D thermo-poro-elastic medium. The object of study is specifically SSEs occurring at the down-dip edge of seismogenic zone in hot subduction zones, where mineral dehydrations (antigorite, lawsonite, chlorite, and glaucophane) are expected to occur near locations where deep slow slip events are observed. In the modeling, we introduce dehydration reactions, coupled with slip-induced dilatancy and thermal pressurization, and slip evolution is assumed to interact with fluid pressure change through Coulomb's frictional stress. Our calculations show that sustained slow slip events occur when the dehydration reaction is coupled with slip-induced dilatancy. Specifically, slow slip is favored by a low initial stress drop, an initial temperature of the medium close to that of the dehydration reaction equilibrium temperature, a low permeability, and overall negative volume change associated with the reaction (i.e., void space created by the reaction larger than the space occupied by the fluid released). Importantly, if we do not assume slip-induced dilatancy, slip is accelerated with time soon after the slip onset even if the dehydration reaction is assumed. This suggests that slow slip is sustained for a long time at hot subduction zones because dehydration reaction is coupled with slip-induced dilatancy. Such slip-induced dilatancy may occur at the down-dip edge of seismogenic zone at hot subduction zones because of repetitive occurrence of dehydration reaction there.

  13. Balance Disorders

    Science.gov (United States)

    ... going to fall Lightheadedness, faintness, or a floating sensation Blurred vision Confusion or disorientation. Other symptoms might include nausea ... if I might faint? Do I have blurred vision? Do I ever feel disoriented—losing my sense of time or location? How can I help ...

  14. Electrophoresis of particles with Navier velocity slip.

    Science.gov (United States)

    Park, Hung Mok

    2013-03-01

    In the present investigation, it is found that the electrophoretic mobility of hydrophobic particles is affected not only by the zeta potential but also by the velocity slip at the particle surface. From a physicochemical viewpoint, zeta potential represents the surface charge properties and the slip coefficient indicates the hydrophobicity of the particle surface. Thus, it is necessary to separate the contribution of zeta potential from that of slip coefficient to the particle mobility, since zeta potential can be changed by varying the bulk ionic concentration while the slip coefficient can be modified by adjusting surfactant concentration. In the present investigation, a method is devised that allows a simultaneous estimation of zeta potential and slip coefficient of micro and nanoparticles using measurements of electrophoretic mobility at various bulk ionic concentrations. Employing a nonlinear curve-fitting technique and an analytic solution of electrophoresis for a particle with velocity slip, the present technique predicts both zeta potential and slip coefficient simultaneously with reasonable accuracy using the measured values of electrophoretic mobility at various bulk ionic concentrations.

  15. Dynamical Stability of Slip-stacking Particles

    CERN Document Server

    Eldred, Jeffrey

    2014-01-01

    We study the stability of particles in slip-stacking configuration, used to nearly double proton beam intensity at Fermilab. We introduce universal area factors to calculate the available phase space area for any set of beam parameters without individual simulation. We find perturbative solutions for stable particle trajectories. We establish Booster beam quality requirements to achieve 97\\% slip-stacking efficiency. We show that slip-stacking dynamics directly correspond to the driven pendulum and to the system of two standing-wave traps moving with respect to each other.

  16. Tsunami Hazards From Strike-Slip Earthquakes

    Science.gov (United States)

    Legg, M. R.; Borrero, J. C.; Synolakis, C. E.

    2003-12-01

    Strike-slip faulting is often considered unfavorable for tsunami generation during large earthquakes. Although large strike-slip earthquakes triggering landslides and then generating substantial tsunamis are now recognized hazards, many continue to ignore the threat from submarine tectonic displacement during strike-slip earthquakes. Historical data record the occurrence of tsunamis from strike-slip earthquakes, for example, 1906 San Francisco, California, 1994 Mindoro, Philippines, and 1999 Izmit, Turkey. Recognizing that strike-slip fault zones are often curved and comprise numerous en echelon step-overs, we model tsunami generation from realistic strike-slip faulting scenarios. We find that tectonic seafloor uplift, at a restraining bend or"pop-up" structure, provides an efficient mechanism to generate destructive local tsunamis; likewise for subsidence at divergent pull-apart basin structures. Large earthquakes on complex strike-slip fault systems may involve both types of structures. The California Continental Borderland is a high-relief submarine part of the active Pacific-North America transform plate boundary. Natural harbors and bays created by long term vertical motion associated with strike-slip structural irregularities are now sites of burgeoning population and major coastal infrastructure. Significant local tsunamis generated by large strike-slip earthquakes pose a serious, and previously unrecognized threat. We model several restraining bend pop-up structures offshore southern California to quantify the local tsunami hazard. Maximum runup derived in our scenarios ranges from one to several meters, similar to runup observed from the 1994 Mindoro, Philippines, (M=7.1) earthquake. The runup pattern is highly variable, with local extremes along the coast. We only model the static displacement field for the strike-slip earthquake source; dynamic effects of moving large island or submerged banks laterally during strike-slip events remains to be examined

  17. Dynamical stability of slip-stacking particles

    Energy Technology Data Exchange (ETDEWEB)

    Eldred, Jeffrey; Zwaska, Robert

    2014-09-01

    We study the stability of particles in slip-stacking configuration, used to nearly double proton beam intensity at Fermilab. We introduce universal area factors to calculate the available phase space area for any set of beam parameters without individual simulation. We find perturbative solutions for stable particle trajectories. We establish Booster beam quality requirements to achieve 97% slip-stacking efficiency. We show that slip-stacking dynamics directly correspond to the driven pendulum and to the system of two standing-wave traps moving with respect to each other.

  18. Slow slip event at Kilauea Volcano

    Science.gov (United States)

    Poland, Michael P.; Miklius, Asta; Wilson, J. David; Okubo, Paul G.; Montgomery-Brown, Emily; Segall, Paul; Brooks, Benjamin; Foster, James; Wolfe, Cecily; Syracuse, Ellen; Thurbe, Clifford

    2010-01-01

    Early in the morning of 1 February 2010 (UTC; early afternoon 31 January 2010 local time), continuous Global Positioning System (GPS) and tilt instruments detected a slow slip event (SSE) on the south flank of Kilauea volcano, Hawaii. The SSE lasted at least 36 hours and resulted in a maximum of about 3 centimeters of seaward displacement. About 10 hours after the start of the slip, a flurry of small earthquakes began (Figure 1) in an area of the south flank recognized as having been seismically active during past SSEs [Wolfe et al., 2007], suggesting that the February earthquakes were triggered by stress associated with slip [Segall et al., 2006].

  19. Dynamical Stability of Slip-stacking Particles

    Energy Technology Data Exchange (ETDEWEB)

    Eldred, Jeffrey [Fermilab; Zwaska, Robert [Fermilab

    2014-09-04

    We study the stability of particles in slip-stacking configuration, used to nearly double proton beam intensity at Fermilab. We introduce universal area factors to calculate the available phase space area for any set of beam parameters without individual simulation. We find perturbative solutions for stable particle trajectories. We establish Booster beam quality requirements to achieve 97% slip-stacking efficiency. We show that slip-stacking dynamics directly correspond to the driven pendulum and to the system of two standing-wave traps moving with respect to each other.

  20. Learning to Lose: Weight Loss Classes and Personal Transformation

    Science.gov (United States)

    Jarvis, Christine

    2012-01-01

    Adult learning takes place not only in educational organisations, but through participation in leisure and special interest groups. Commercially operated weight management organisations recruit large numbers of adults to their classes to learn how to eat healthily and lose weight. They publish readers' "real life" success stories in their…

  1. We're Losing Our Minds: Rethinking American Higher Education

    Science.gov (United States)

    Keeling, Richard P.; Hersh, Richard H.

    2011-01-01

    America is being held back by the quality and quantity of learning in college. This is a true educational emergency! Many college graduates cannot think critically, write effectively, solve problems, understand complex issues, or meet employers' expectations. We are losing our minds--and endangering our social, economic, and scientific leadership.…

  2. 'At Least I Didn't Lose Money'

    DEFF Research Database (Denmark)

    Stephens, Thomas Alexander; Tyran, Jean-Robert Karl

    (monetary) values. Real losses may therefore loom larger in people’s minds when they lose money than when real losses are hidden by purely nominal gains. Using a survey experiment with a large and heterogeneous sample, we show that evaluations of housing transactions are systematically biased by purely...

  3. Clinical practice - Protein-losing enteropathy in children

    NARCIS (Netherlands)

    Braamskamp, M.J.A.M.; Dolman, K.M.; Tabbers, M.M.

    2010-01-01

    Protein-losing enteropathy (PLE) is a rare complication of a variety of intestinal disorders characterized by an excessive loss of proteins into the gastrointestinal tract due to impaired integrity of the mucosa. The clinical presentation of patients with PLE is highly variable, depending upon the

  4. Learning to Lose: Weight Loss Classes and Personal Transformation

    Science.gov (United States)

    Jarvis, Christine

    2012-01-01

    Adult learning takes place not only in educational organisations, but through participation in leisure and special interest groups. Commercially operated weight management organisations recruit large numbers of adults to their classes to learn how to eat healthily and lose weight. They publish readers' "real life" success stories in their…

  5. Analysis of "Babar Loses His Crown." Technical Report No. 169.

    Science.gov (United States)

    Green, G. M.; And Others

    This report presents the text analysis of "Babar Loses His Crown," a story for beginning readers. (The techniques used in arriving at the analysis are presented in a Reading Center Technical Report, Number 168, "Problems and Techniques of Text Analysis.") Tables are given for a statistical lexical analysis and for a syntactic…

  6. Losing the Battle for Balanced Bilingualism: The German-American Case.

    Science.gov (United States)

    Schiffman, Harold

    1987-01-01

    Studies the case of a religious group of German immigrants, whose German-American descendants attended German-language parochial schools but received secular instruction in English. Although the situation resulted in English-dominant children rather than the intended German-dominant bilinguals, recent sociolinguistic, psycholinguistic, and…

  7. Shrink it or lose it: balancing loss of function with shrinking genomes in the microsporidia.

    Science.gov (United States)

    Keeling, Patrick J; Corradi, Nicolas

    2011-01-01

    Microsporidia are obligate intracellular parasites that have evolved an elaborate mechanism for invading animal host cells, but which have otherwise greatly reduced biological complexity. In particular, microsporidia possess the smallest autonomous nuclear genomes known (as opposed to nucleus derived organelles, or nucleomorphs), and their 'anaerobic' core carbon metabolism is severely limited. Here we compare the extremes to which these two characteristics have evolved, and contrast how their reduction has either proceeded within the constraints of an unchanging set of functions, or has reduced the functional capabilities of the cell. Specifically, we review how the smallest known nuclear genome, the 2.3 Mbp genome of Encephalitozoon intestinalis, has arrived at this diminutive form without significantly affecting its protein-coding complexity in comparison with closely related, larger genomes. In contrast to this, Enterocytozoon bieneusi has a relatively large genome, and yet has lost all enzymes necessary to synthesize ATP from sugar - imposing a major limitation on the functional capabilities of the cell. The extremity of this reduction demands a re-evaluation of metabolic processes in other microsporidia: although pathways such as glycolysis are present, comparative genomic data suggest they may not play the cellular role that they are generally assumed to play.

  8. Balancing Acts

    Science.gov (United States)

    ... Past Issues Special Section: Focus on Communication Balancing Acts Past Issues / Fall 2008 Table of Contents For ... scientific research on hearing, balance, smell, taste, voice, speech, and language—common elements in how we perceive ...

  9. Action slips during whole-body vibration.

    Science.gov (United States)

    Ishimatsu, Kazuma; Meland, Anders; Hansen, Tor Are S; Kåsin, Jan Ivar; Wagstaff, Anthony S

    2016-07-01

    Helicopter aircrew members engage in highly demanding cognitive tasks in an environment subject to whole-body vibration (WBV). Sometimes their actions may not be according to plan (e.g. action slips and lapses). This study used a Sustained Attention to Response Task (SART) to examine whether action slips were more frequent during exposure to WBV. Nineteen participants performed the SART in two blocks. In the WBV block participants were exposed to 17 Hz vertical WBV, which is typical of larger helicopter working environments. In the No-WBV block there was no WBV. There were more responses to the rare no-go digit 3 (i.e. action slips) in the WBV block, and participants responded faster in the WBV block. These results suggest that WBV influences response inhibition, and can induce impulsive responding. WBV may increase the likelihood of action slips, mainly due to failure of response inhibition.

  10. Deterministic phase slips in mesoscopic superconducting rings

    Science.gov (United States)

    Petković, I.; Lollo, A.; Glazman, L. I.; Harris, J. G. E.

    2016-11-01

    The properties of one-dimensional superconductors are strongly influenced by topological fluctuations of the order parameter, known as phase slips, which cause the decay of persistent current in superconducting rings and the appearance of resistance in superconducting wires. Despite extensive work, quantitative studies of phase slips have been limited by uncertainty regarding the order parameter's free-energy landscape. Here we show detailed agreement between measurements of the persistent current in isolated flux-biased rings and Ginzburg-Landau theory over a wide range of temperature, magnetic field and ring size; this agreement provides a quantitative picture of the free-energy landscape. We also demonstrate that phase slips occur deterministically as the barrier separating two competing order parameter configurations vanishes. These results will enable studies of quantum and thermal phase slips in a well-characterized system and will provide access to outstanding questions regarding the nature of one-dimensional superconductivity.

  11. The slipping rib syndrome in children.

    Science.gov (United States)

    Saltzman, D A; Schmitz, M L; Smith, S D; Wagner, C W; Jackson, R J; Harp, S

    2001-11-01

    The slipping rib syndrome is an infrequent cause of thoracic and upper abdominal pain and is thought to arise from the inadequacy or rupture of the interchondral fibrous attachments of the anterior ribs. This disruption allows the costal cartilage tips to sublux, impinging on the intercostal nerves. Children with this entity are seldom described in the literature. We present a retrospective review of 12 children and young adults with slipping rib syndrome and a systematic approach for evaluation and treatment.

  12. 以一敌百Slip-on

    Institute of Scientific and Technical Information of China (English)

    王海琳

    2016-01-01

    在运动鞋爆红的当下,一种不系带的Slip-on Sneakers成为了时尚人士的必备单品。Slip-on Sneakers就是把脚放进去即可的休闲鞋,由于穿脱方便,有了一个可爱的别名——"一脚蹬"。

  13. Phase Slips in Topological Superconductor Wire Devices

    Science.gov (United States)

    Goldberg, Samuel; Bergman, Doron; Pekker, David; Refael, Gil

    2012-02-01

    We make a detailed study of phase slips in topological superconducting wires and devices based on topological wires. We begin by investigating a device composed of a topological superconducting wire connected to a non-topological wire (T-S). In the T-segment only slips of the phase by multiples of 4π are allowed, while in the S-segment slips by 2π are also allowed. We show that near the interface, 2π phase slips are also allowed and we comment on the consequences of such phase slips for the Aharonov-Casher effect. We also consider an implementation of a q-bit consisting of a T-S-T device, where the quantum information is stored in the parity of the two topological segments via the four Majorana modes. We show that the central S-segment of this type of device can support 2π phase-slips which result in the decoherence of the q-bit.

  14. Slip Development and Instability on a Heterogeneously Loaded Fault with Power-Law Slip-Weakening

    Science.gov (United States)

    Rice, J. R.; Uenishi, K.

    2002-12-01

    We consider slip initiation and rupture instability on planar faults that follow a non-linear slip-weakening relation and are subjected to a locally peaked loading stress, the level of which changes quasi-statically in time. For the case in which strength weakens linearly with slip, Uenishi and Rice [2002] (http://esag.harvard.edu/uenishi/research/nl/nl.html) have shown there exists a universal length of the slipping region at instability, independent of any length scales entering into the description of the shape of the loading stress distribution. Here we study slip development and its (in)stability for a power-law slip-weakening relation, giving fault strength as τ = τ p - Aδn where τ p is the peak strength at which slip initiates, δ is the slip, and A is a constant. Such a form with n ≈ 0.2-0.4 has been inferred, for slips from 1 to 500 mm, as an interpretation of seismological observations on the scaling of radiated energy with slip [Abercrombie and Rice, EOS, 2001; SCEC, 2002]. It is also consistent with laboratory experiments involving large rotary shear [Chambon et al., GRL, 2002]. We first employed an energy approach to give a Rayleigh-Ritz approximation for the dependence of slipping length and maximum slip on the level and shape of the loading stress distribution. That was done for a loading stress distribution τ p + Rt - κ x2 / 2 where x is distance along the fault, κ is a constant, and Rt is the stress change from that for which the peak in the loading stress distribution equals the strength τ p. Results show there is no longer a universal nucleation length, independent of κ , when n != 1, and that qualitative features of the slip development are significantly controlled by n. We also obtained full numerical solutions for the slip development. Remarkably, predictions of the simple energy approach are in reasonable quantitative agreement with them and give all qualitative features correctly. Principal results are as follows: If n > 2/3, the

  15. Nonlinear dynamical triggering of slow slip

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Paul A [Los Alamos National Laboratory; Knuth, Matthew W [WISCONSIN; Kaproth, Bryan M [PENN STATE; Carpenter, Brett [PENN STATE; Guyer, Robert A [Los Alamos National Laboratory; Le Bas, Pierre - Yves [Los Alamos National Laboratory; Daub, Eric G [Los Alamos National Laboratory; Marone, Chris [PENN STATE

    2010-12-10

    Among the most fascinating, recent discoveries in seismology have been the phenomena of triggered slip, including triggered earthquakes and triggered-tremor, as well as triggered slow, silent-slip during which no seismic energy is radiated. Because fault nucleation depths cannot be probed directly, the physical regimes in which these phenomena occur are poorly understood. Thus determining physical properties that control diverse types of triggered fault sliding and what frictional constitutive laws govern triggered faulting variability is challenging. We are characterizing the physical controls of triggered faulting with the goal of developing constitutive relations by conducting laboratory and numerical modeling experiments in sheared granular media at varying load conditions. In order to simulate granular fault zone gouge in the laboratory, glass beads are sheared in a double-direct configuration under constant normal stress, while subject to transient perturbation by acoustic waves. We find that triggered, slow, silent-slip occurs at very small confining loads ({approx}1-3 MPa) that are smaller than those where dynamic earthquake triggering takes place (4-7 MPa), and that triggered slow-slip is associated with bursts of LFE-like acoustic emission. Experimental evidence suggests that the nonlinear dynamical response of the gouge material induced by dynamic waves may be responsible for the triggered slip behavior: the slip-duration, stress-drop and along-strike slip displacement are proportional to the triggering wave amplitude. Further, we observe a shear-modulus decrease corresponding to dynamic-wave triggering relative to the shear modulus of stick-slips. Modulus decrease in response to dynamical wave amplitudes of roughly a microstrain and above is a hallmark of elastic nonlinear behavior. We believe that the dynamical waves increase the material non-affine elastic deformation during shearing, simultaneously leading to instability and slow-slip. The inferred

  16. GPS dynamic cycle slip detection and correction with baseline constraint

    Institute of Scientific and Technical Information of China (English)

    Liu Zhenkun; Huang Ahunji

    2009-01-01

    When the cycle slips take place in the attitude determination of a moving platform, the precision of the attitude will be impaired badly. A method of cycle slip detection and correction is proposed, which is suitable to the dynamic measurement using GPS carrier phase: the cycle slips detection is first achieved by triple difference observables, then the cycle slips correction is performed with baseline length constraint. The simulation results show that the proposed method is effective to the dynamic cycle slips problem.

  17. Dopamine release in ventral striatum of pathological gamblers losing money

    DEFF Research Database (Denmark)

    Linnet, J; Peterson, E; Doudet, D J;

    2010-01-01

    Linnet J, Peterson E, Doudet DJ, Gjedde A, Møller A. Dopamine release in ventral striatum of pathological gamblers losing money. Objective: To investigate dopaminergic neurotransmission in relation to monetary reward and punishment in pathological gambling. Pathological gamblers (PG) often continue...... gambling despite losses, known as 'chasing one's losses'. We therefore hypothesized that losing money would be associated with increased dopamine release in the ventral striatum of PG compared with healthy controls (HC). Method: We used Positron Emission Tomography (PET) with [(11)C]raclopride to measure...... dopamine release in the ventral striatum of 16 PG and 15 HC playing the Iowa Gambling Task (IGT). Results: PG who lost money had significantly increased dopamine release in the left ventral striatum compared with HC. PG and HC who won money did not differ in dopamine release. Conclusion: Our findings...

  18. The ambivalence of losing weight after bariatric surgery

    Directory of Open Access Journals (Sweden)

    Christine Warholm

    2014-01-01

    Full Text Available This study is grounded in a phenomenological lifeworld perspective. It aims at providing rich descriptions of lived experience of the process of losing weight after obesity surgery. Two women participated in in-depth interviews four times each during the first postoperative year. Based on the women's experiences, a meaning structure—the ambivalence of losing weight after obesity surgery—was identified across the women's processes of change. This consisted of five core themes: movement and activity—freedom but new demands and old restraints; eating habits and digestion—the complexity of change; appearance—smaller, but looser; social relations—stability and change; and being oneself—vulnerability and self-assurance. These core themes changed over time in terms of dominance. The experience of ambivalence is discussed according to a phenomenological perspective of the body as lived experience.

  19. Nothing to lose: why early career scientists make ideal entrepreneurs.

    Science.gov (United States)

    Thon, Jonathan N

    2014-12-01

    An entrepreneurial movement within science strives to invert the classical trajectory of academic research careers by positioning trainees at the apex of burgeoning industries. Young scientists today have nothing to lose and everything to gain by pursuing this 'third road', and academic institutes and established companies only stand to benefit from supporting this emerging movement of discovery research with economic purpose. Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. Losing Thomas & Ella: A Father's Story (A Research Comic).

    Science.gov (United States)

    Weaver-Hightower, Marcus B

    2015-10-14

    "Losing Thomas & Ella" presents a research comic about one father's perinatal loss of twins. The comic recounts Paul's experience of the hospital and the babies' deaths, and it details the complex grieving process afterward, including themes of anger, distance, relationship stress, self-blame, religious challenges, and resignation. A methodological appendix explains the process of constructing the comic and provides a rationale for the use of comics-based research for illness, death, and grief among practitioners, policy makers, and the bereaved.

  1. Losing a valued member of the medical practice team.

    Science.gov (United States)

    Hills, Laura

    2014-01-01

    Losing a valued member of your staff can be disruptive, painful, and costly to your medical practice. And despite your best intentions and impeccable employee management policies and skills, things will happen beyond your control, and people move on. Being prepared for that possibility will help you minimize and contain the damage and move your practice forward. This article suggests 15 strategies that you can use to mitigate the effects of losing a valued employee. These include strategies to protect your practice's interests and several that will smooth the transition for your remaining staff. This article also describes 10 ways that losing a valued employee can impact a practice. It offers 10 additional strategies to help you cope with the death of an employee, one of the most difficult challenges a practice manager may ever face. This article further suggests several easy-to-implement practice management techniques that will help you soften the blow of employee turnover. It offers a sample farewell letter to announce an employee's departure from your practice and suggests six knowledge transfer questions to ask before the employee leaves. Finally, this article provides a comprehensive list of more than 30 thoughtful, eye-opening, and revealing questions that you can ask in an employee exit interview or exit survey.

  2. Progressive slip after removal of screw fixation in slipped capital femoral epiphysis: two case reports

    Directory of Open Access Journals (Sweden)

    Engelsma Yde

    2012-11-01

    Full Text Available Abstract Introduction In slipped capital femoral epiphysis the femoral neck displaces relative to the head due to weakening of the epiphysis. Early recognition and adequate surgical fixation is essential for a good functional outcome. The fixation should be secured until the closure of the epiphysis to prevent further slippage. A slipped capital femoral epiphysis should not be confused with a femoral neck fracture. Case presentation Case 1 concerns a 15-year-old boy with an adequate initial screw fixation of his slipped capital femoral epiphysis. Unfortunately, it was thought that the epiphysis had healed and the screw was removed after 11 weeks. This caused new instability with a progressive slip of the femoral epiphysis and subsequently re-fixation and a subtrochanteric correction osteotomy was obligatory. Case 2 concerns a 13-year-old girl with persistent hip pain after screw fixation for slipped capital femoral epiphysis. The screw was removed as lysis was seen around the screw on the hip X-ray. This operation created a new unstable situation and the slip progressed resulting in poor hip function. A correction osteotomy with re-screw fixation was performed with a good functional result. Conclusion A slipped epiphysis of the hip is not considered ‘healed’ after a few months. Given the risk of progression of the slip the fixation material cannot be removed before closure of the growth plate.

  3. Balancing Audio

    DEFF Research Database (Denmark)

    Walther-Hansen, Mads

    2016-01-01

    This paper explores the concept of balance in music production and examines the role of conceptual metaphors in reasoning about audio editing. Balance may be the most central concept in record production, however, the way we cognitively understand and respond meaningfully to a mix requiring balance...... is not thoroughly understood. In this paper I treat balance as a metaphor that we use to reason about several different actions in music production, such as adjusting levels, editing the frequency spectrum or the spatiality of the recording. This study is based on an exploration of a linguistic corpus of sound...

  4. Evidence for slip partitioning and bimodal slip behavior on a single fault: Surface slip characteristics of the 2013 Mw7.7 Balochistan, Pakistan earthquake

    Science.gov (United States)

    Barnhart, W. D.; Briggs, R. W.; Reitman, N. G.; Gold, R. D.; Hayes, G. P.

    2015-06-01

    Deformation is commonly accommodated by strain partitioning on multiple, independent strike-slip and dip-slip faults in continental settings of oblique plate convergence. As a corollary, individual faults tend to exhibit one sense of slip - normal, reverse, or strike-slip - until whole-scale changes in boundary conditions reactivate preexisting faults in a new deformation regime. In this study, we show that a single continental fault may instead partition oblique strain by alternatively slipping in a strike-slip or a dip-slip sense during independent fault slip events. We use 0.5 m resolution optical imagery and sub-pixel correlation analysis of the 200 + km 2013 Mw7.7 Balochistan, Pakistan earthquake to document co-seismic surface slip characteristics and Quaternary tectonic geomorphology along the causative Hoshab fault. We find that the 2013 earthquake, which involved a ∼6:1 strike-slip to dip-slip ratio, ruptured a structurally segmented fault. Quaternary geomorphic indicators of gross fault-zone morphology reveal both reverse-slip and strike-slip deformation in the rupture area of the 2013 earthquake that varies systematically along fault strike despite nearly pure strike-slip motion in 2013. Observations of along-strike variations in range front relief and geomorphic offsets suggest that the Hoshab fault accommodates a substantial reverse component of fault slip in the Quaternary, especially along the southern section of the 2013 rupture. We surmise that Quaternary bimodal slip along the Hoshab fault is promoted by a combination of the arcuate geometry of the Hoshab fault, the frictional weakness of the Makran accretionary prism, and time variable loading conditions from adjacent earthquakes and plate interactions.

  5. Slip in viscous contact-line movement

    Science.gov (United States)

    van Lengerich, Henrik; Steen, Paul; Breuer, Kenneth

    2011-11-01

    The typical continuum fluid dynamics formulation cannot be used to model the spreading of a liquid on a solid because a stress singularity prevents contact-line motion. It is well known that this situation can be remedied by introducing a slip. We perform Stokes-flow simulations with slip and compare these with experiments. In the experiment, liquid (squalane) is forced through two parallel sapphire plates (roughness 0.6nm), and the meniscus shape and its speed are measured. The slip-length for this liquid/solid pair has been measured previously in an independent experiment absent of contact lines (T. Schmatko et. al. PRL 94, 244501). The same geometry is used in a boundary integral method simulation, accurate to within a few molecular diameters in the vicinity of the contact-line. The slip-length in the simulations can be varied such that the meniscus shape matches the experiment. Preliminary results suggest this slip-length is an order of magnitude lower than that reported by Schmatko. Now at the University of Minnesota TC

  6. Gait abnormalities following slipped capital femoral epiphysis.

    Science.gov (United States)

    Song, Kit M; Halliday, Suzanne; Reilly, Chris; Keezel, William

    2004-01-01

    The authors evaluated 30 subjects with treated unilateral slipped capital femoral epiphysis and a range of severity from mild to severe to characterize gait and strength abnormalities using instrumented three-dimensional gait analysis and isokinetic muscle testing. For slip angles less than 30 degrees, kinematic, kinetic, and strength variables were not significantly different from age- and weight-matched controls. For moderate to severe slips, as slip angle increased, passive hip flexion, hip abduction, and internal rotation in the flexed and extended positions decreased significantly. Persistent pelvic obliquity, medial lateral trunk sway, and trunk obliquity in stance increased, as did extension, adduction, and external rotation during gait. Gait velocity and step length decreased with increased amount of time spent in double limb stance. Hip abductor moment, hip extension moment, knee flexion moment, and ankle dorsiflexion moment were all decreased on the involved side. Hip and knee strength also decreased with increasing slip severity. All of these changes were present on the affected and to a lesser degree the unaffected side. Body center of mass translation or pelvic obliquity in mid-stance greater than one standard deviation above normal correlated well with the impression of compensated or uncompensated Trendelenburg gait.

  7. [An experimental study on freudian slips].

    Science.gov (United States)

    Köhler, Thomas; Simon, Patrick

    2002-01-01

    We attempted to replicate findings of a frequently cited study by Motley. This author had used a tachistoskope to present his participants pairs of words which had a meaning after exchanging the initial letters of each word ("spoonerisms"). In accordance with the psychoanalytic theory of Freudian slips, Motley was able to show that under the impression of a sexually stimulating situation more sexual words were read; under the threat of electric shock spoonerisms appeared more often in words with reference to electricity. In our study we tried to induce spoonerisms by presentation of short written texts of erotic, aggressive and neutral content. It could be shown that after reading the erotic and the aggressive text, slips were produced more often than following the text of neutral content. In addition, significantly more slips of erotic kind occurred after reading the erotic text, whereas more aggressive slips were observed immediately after lecture of the text with aggressive content. We were therefore able to replicate Motley's findings and thus also corroborated assumptions made by Freud on the origin of slips of the tongue.

  8. Slip patterns and preferred dislocation boundary planes

    DEFF Research Database (Denmark)

    Winther, G.

    2003-01-01

    The planes of deformation induced extended planar dislocation boundaries are analysed in two different co-ordinate systems, namely the macroscopic system defined by the deformation axes and the crystallographic system given by the crystallographic lattice. The analysis covers single and polycryst......The planes of deformation induced extended planar dislocation boundaries are analysed in two different co-ordinate systems, namely the macroscopic system defined by the deformation axes and the crystallographic system given by the crystallographic lattice. The analysis covers single...... and polycrystals of fcc metals in three deformation modes (rolling, tension and torsion). In the macroscopic system, boundaries lie close to the macroscopically most stressed planes. In the crystallographic system, the boundary plane depends on the grain/crystal orientation. The boundary planes in both co......-ordinate systems are rationalised based on the slip. The more the slip is concentrated on a slip plane, the closer the boundaries lie to this. The macroscopic preference arises from the macroscopic directionality of the slip. The established relations are applied to (a) prediction of boundary planes from slip...

  9. Constraining the roughness degree of slip heterogeneity

    KAUST Repository

    Causse, Mathieu

    2010-05-07

    This article investigates different approaches for assessing the degree of roughness of the slip distribution of future earthquakes. First, we analyze a database of slip images extracted from a suite of 152 finite-source rupture models from 80 events (Mw = 4.1–8.9). This results in an empirical model defining the distribution of the slip spectrum corner wave numbers (kc) as a function of moment magnitude. To reduce the “epistemic” uncertainty, we select a single slip model per event and screen out poorly resolved models. The number of remaining models (30) is thus rather small. In addition, the robustness of the empirical model rests on a reliable estimation of kc by kinematic inversion methods. We address this issue by performing tests on synthetic data with a frequency domain inversion method. These tests reveal that due to smoothing constraints used to stabilize the inversion process, kc tends to be underestimated. We then develop an alternative approach: (1) we establish a proportionality relationship between kc and the peak ground acceleration (PGA), using a k−2 kinematic source model, and (2) we analyze the PGA distribution, which is believed to be better constrained than slip images. These two methods reveal that kc follows a lognormal distribution, with similar standard deviations for both methods.

  10. Breddin's Graph For Fault and Slip Data

    Science.gov (United States)

    Célérier, B.

    A simple plot of rake versus strike of fault and slip or earthquake focal mechanism data provides insight into the stress regime that caused slippage on these faults provided one of the principal stress direction is near vertical. By overlaying an abacus on this plot, one can evaluate both the orientation of the horizontal principal stress directions and the stress tensor aspect ratio, (s1-s2)/(s1-s3), where s1, s2, s3 are the principal stress magnitudes ranked in decreasing order. The underlying geometrical properties are that the slip data that are near strike-slip, and that are mainly found on steeply dipping planes, constrain the horizontal principal stress directions whereas the slip data that are near dip-slip and that occur on shallow dipping planes striking away from the principal stress directions constrain the stress tensor aspect ratio. This abacus is an extension of the Breddin's abacus used to analyze two dimensional deformation in structural geology and it is used in a similar fashion. Its application to synthetic and natural monophase data show both its usefulness and limitation. It is not intended to replace stress inversion techniques because of limiting assumptions, but it is expected to provide insight into the complexity of natural data set from a simple viewpoint.

  11. Slip rate and slip magnitudes of past earthquakes along the Bogd left-lateral strike-slip fault (Mongolia)

    Science.gov (United States)

    Prentice, Carol S.; Rizza, M.; Ritz, J.F.; Baucher, R.; Vassallo, R.; Mahan, S.

    2011-01-01

    We carried out morphotectonic studies along the left-lateral strike-slip Bogd Fault, the principal structure involved in the Gobi-Altay earthquake of 1957 December 4 (published magnitudes range from 7.8 to 8.3). The Bogd Fault is 260 km long and can be subdivided into five main geometric segments, based on variation in strike direction. West to East these segments are, respectively: the West Ih Bogd (WIB), The North Ih Bogd (NIB), the West Ih Bogd (WIB), the West Baga Bogd (WBB) and the East Baga Bogd (EBB) segments. Morphological analysis of offset streams, ridges and alluvial fans—particularly well preserved in the arid environment of the Gobi region—allows evaluation of late Quaternary slip rates along the different faults segments. In this paper, we measure slip rates over the past 200 ka at four sites distributed across the three western segments of the Bogd Fault. Our results show that the left-lateral slip rate is∼1 mm yr–1 along the WIB and EIB segments and∼0.5 mm yr–1 along the NIB segment. These variations are consistent with the restraining bend geometry of the Bogd Fault. Our study also provides additional estimates of the horizontal offset associated with the 1957 earthquake along the western part of the Bogd rupture, complementing previously published studies. We show that the mean horizontal offset associated with the 1957 earthquake decreases progressively from 5.2 m in the west to 2.0 m in the east, reflecting the progressive change of kinematic style from pure left-lateral strike-slip faulting to left-lateral-reverse faulting. Along the three western segments, we measure cumulative displacements that are multiples of the 1957 coseismic offset, which may be consistent with a characteristic slip. Moreover, using these data, we re-estimate the moment magnitude of the Gobi-Altay earthquake at Mw 7.78–7.95. Combining our slip rate estimates and the slip distribution per event we also determined a mean recurrence interval of∼2500

  12. Balanced sampling

    NARCIS (Netherlands)

    Brus, D.J.

    2015-01-01

    In balanced sampling a linear relation between the soil property of interest and one or more covariates with known means is exploited in selecting the sampling locations. Recent developments make this sampling design attractive for statistical soil surveys. This paper introduces balanced sampling

  13. Balanced sampling

    NARCIS (Netherlands)

    Brus, D.J.

    2015-01-01

    In balanced sampling a linear relation between the soil property of interest and one or more covariates with known means is exploited in selecting the sampling locations. Recent developments make this sampling design attractive for statistical soil surveys. This paper introduces balanced sampling

  14. A viscoplastic shear-zone model for episodic slow slip events in oceanic subduction zones

    Science.gov (United States)

    Yin, A.; Meng, L.

    2016-12-01

    Episodic slow slip events occur widely along oceanic subduction zones at the brittle-ductile transition depths ( 20-50 km). Although efforts have been devoted to unravel their mechanical origins, it remains unclear about the physical controls on the wide range of their recurrence intervals and slip durations. In this study we present a simple mechanical model that attempts to account for the observed temporal evolution of slow slip events. In our model we assume that slow slip events occur in a viscoplastic shear zone (i.e., Bingham material), which has an upper static and a lower dynamic plastic yield strength. We further assume that the hanging wall deformation is approximated as an elastic spring. We envision the shear zone to be initially locked during forward/landward motion but is subsequently unlocked when the elastic and gravity-induced stress exceeds the static yield strength of the shear zone. This leads to backward/trenchward motion damped by viscous shear-zone deformation. As the elastic spring progressively loosens, the hanging wall velocity evolves with time and the viscous shear stress eventually reaches the dynamic yield strength. This is followed by the termination of the trenchward motion when the elastic stress is balanced by the dynamic yield strength of the shear zone and the gravity. In order to account for the zig-saw slip-history pattern of typical repeated slow slip events, we assume that the shear zone progressively strengthens after each slow slip cycle, possibly caused by dilatancy as commonly assumed or by progressive fault healing through solution-transport mechanisms. We quantify our conceptual model by obtaining simple analytical solutions. Our model results suggest that the duration of the landward motion increases with the down-dip length and the static yield strength of the shear zone, but decreases with the ambient loading velocity and the elastic modulus of the hanging wall. The duration of the backward/trenchward motion depends

  15. Fault Wear During Earthquake-Like Slip-Events in Laboratory Experiments

    Science.gov (United States)

    Reches, Z.; Chang, J. C.; Boneh, Y.; Lockner, D. A.

    2010-12-01

    wear (~160 microns), dilation (~300 microns), and extreme wear-rate intensity (up to 20,000 micron/m) for relatively short slip distances. These intensities and their relations to the associated friction suggest that gouge processes, in particular its formation and flow, control the weakening and strengthening of a fault patch during earthquake slip. We will use the experimental mechanical data to analyze the contributions of these processes to the energy balance in earthquake-like slip-event in our experiments.

  16. Experimental Modeling of Dynamic Shallow Dip-Slip Faulting

    Science.gov (United States)

    Uenishi, K.

    2010-12-01

    , Japan in 2008, for example, seem to support the need for careful mechanical consideration. In this contribution, utilizing two-dimensional dynamic photoelasticity in conjunction with high speed digital cinematography, we try to perform "fully controlled" laboratory experiments of dip-slip faulting and observe the propagation of interface pulses and corner waves mentioned above. A birefringent material containing a (model) dip-slip fault plane is prepared, and rupture is initiated in that material using an Nd:YAG laser system, and the evolution of time-dependent isochromatic fringe patterns (contours of maximum in-plane shear stress) associated with the dynamic process of shallow dip-slip faulting is recorded. Use of Nd:YAG laser pulses, instead of ignition of explosives, for rupture initiation may enhance the safety of laboratory fracture experiments and enable us to evaluate the energy entering the material (and hence the energy balance in the system) more precisely, possibly in a more controlled way.

  17. Quake clamps down on slow slip

    Science.gov (United States)

    Wallace, Laura M.; Bartlow, Noel; Hamling, Ian; Fry, Bill

    2014-12-01

    Using continuous GPS (cGPS) data from the Hikurangi subduction zone in New Zealand, we show for the first time that stress changes induced by a local earthquake can arrest an ongoing slow slip event (SSE). The cGPS data show that the slip rate in the northern portion of the 2013/2014 Kapiti SSE decreased abruptly following a nearby intraslab earthquake. We suggest that deceleration of the Kapiti SSE in early 2014 occurred due to a tenfold increase in the normal stress relative to shear stress in the SSE source, induced by the nearby Mw 6.3 earthquake, consistent with expectations of rate and state friction. Our observation of an abrupt halting/slowing of the SSE in response to stress changes imposed by a local earthquake has implications for the strength of fault zones hosting SSEs and supports the premise that static stress changes are an important ingredient in triggering (or delaying) fault slip.

  18. Vaporization of fault water during seismic slip

    Science.gov (United States)

    Chen, Jianye; Niemeijer, André R.; Fokker, Peter A.

    2017-06-01

    Laboratory and numerical studies, as well as field observations, indicate that phase transitions of pore water might be an important process in large earthquakes. We present a model of the thermo-hydro-chemo-mechanical processes, including a two-phase mixture model to incorporate the phase transitions of pore water, occurring during fast slip (i.e., a natural earthquake) in order to investigate the effects of vaporization on the coseismic slip. Using parameters from typical natural faults, our modeling shows that vaporization can indeed occur at the shallow depths of an earthquake, irrespective of the wide variability of the parameters involved (sliding velocity, friction coefficient, gouge permeability and porosity, and shear-induced dilatancy). Due to the fast kinetics, water vaporization can cause a rapid slip weakening even when the hydrological conditions of the fault zone are not favorable for thermal pressurization, e.g., when permeability is high. At the same time, the latent heat associated with the phase transition causes the temperature rise in the slip zone to be buffered. Our parametric analyses reveal that the amount of frictional work is the principal factor controlling the onset and activity of vaporization and that it can easily be achieved in earthquakes. Our study shows that coseismic pore fluid vaporization might have played important roles at shallow depths of large earthquakes by enhancing slip weakening and buffering the temperature rise. The combined effects may provide an alternative explanation for the fact that low-temperature anomalies were measured in the slip zones at shallow depths of large earthquakes.

  19. Momentum compaction and phase slip factor

    Energy Technology Data Exchange (ETDEWEB)

    Ng, K.Y.; /Fermilab

    2010-10-01

    Section 2.3.11 of the Handbook of Accelerator Physics and Engineering on Landau damping is updated. The slip factor and its higher orders are given in terms of the various orders of the momentum compaction. With the aid of a simplified FODO lattice, formulas are given for the alteration of the lower orders of the momentum compaction by various higher multipole magnets. The transition to isochronicity is next demonstrated. Formulas are given for the extraction of the first three orders of the slip factor from the measurement of the synchrotron tune while changing the rf frequency. Finally bunch-length compression experiments in semi-isochronous rings are reported.

  20. Slipping magnetic reconnection in coronal loops.

    Science.gov (United States)

    Aulanier, Guillaume; Golub, Leon; Deluca, Edward E; Cirtain, Jonathan W; Kano, Ryouhei; Lundquist, Loraine L; Narukage, Noriyuki; Sakao, Taro; Weber, Mark A

    2007-12-07

    Magnetic reconnection of solar coronal loops is the main process that causes solar flares and possibly coronal heating. In the standard model, magnetic field lines break and reconnect instantaneously at places where the field mapping is discontinuous. However, another mode may operate where the magnetic field mapping is continuous but shows steep gradients: The field lines may slip across each other. Soft x-ray observations of fast bidirectional motions of coronal loops, observed by the Hinode spacecraft, support the existence of this slipping magnetic reconnection regime in the Sun's corona. This basic process should be considered when interpreting reconnection, both on the Sun and in laboratory-based plasma experiments.

  1. Fault zone roughness controls slip stability

    Science.gov (United States)

    Harbord, Christopher; Nielsen, Stefan; De Paola, Nicola

    2016-04-01

    Fault roughness is an important control factor in the mechanical behaviour of fault zones, in particular the frictional slip stability and subsequent earthquake nucleation. Despite this, there is little experimental quantification as to the effects of varying roughness upon rate- and state-dependant friction (RSF). Utilising a triaxial deformation apparatus and a novel adaptation of the direct shear methodology to simulate initially bare faults in Westerly Granite, we performed a series of velocity step frictional sliding experiments. Initial root mean square roughnesses (Sq) was varied in the range 6x10-7 - 2.4x10-5 m. We also investigated the effects upon slip stability of normal stress variation in the range σn = 30 - 200 MPa, and slip velocity between 0.1 - 10 μm s-1. A transition from stable sliding to unstable slip (manifested by stick-slip and slow slip events) was observed, depending on the parameter combination, thus covering the full spectrum of fault slip behaviours. At low normal stress (σn = 30MPa) smooth faults (Sqstress drops on slow slip events upon velocity increase), with strongly velocity weakening friction. When normal stress is increased to intermediate values (σn = 100 - 150 MPa), smooth faults (Sqstress (σn = 200 MPa) a transition from unstable to stable sliding is observed for smooth faults, which is not expected using RSF stability criteria. At all conditions sliding is stable for rough faults (Sq> 1x10-6 m). We find that instability can develop when the ratio of fault to critical stiffness kf kc > 10, or, alternatively, even when a - b > 0 at σn = 150MPa, suggesting that bare surfaces may not strictly obey the R+S stability condition. Additionally we present white light interferometry and SEM analysis of experimentally deformed samples which provide information about the distribution and physical nature of frictional contact. Significantly we suggest that bare fault surfaces may require a different stability criterion (based on

  2. Numerical Analysis of the Slip Velocity and Temperature-Jump in Microchannel Using Langmuir Slip Boundary Condition

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sang Woo; Kim, Hyun Goo; Lee, Do Hyung [Hanyang University, Seoul (Korea, Republic of)

    2009-03-15

    The slip velocity and the temperature jumps for low-speed flow in microchannels are investigated using Langmuir slip boundary condition. This slip boundary condition is suggested to simulate micro flow. The current study analyzes Langmuir slip boundary condition theoretically and it analyzed numerically micro-Couette flow, micro-Poiseuille flow and grooved microchannel flow. First, to prove validity for Langmuir slip condition, an analytical solution for micro-Couette flow is derived from Navier-Stokes equations with Langmuir slip conditions and is compared with DSMC and an analytical solution with Maxwell slip boundary condition. Second, the numerical analysis is performed for micro-Poiseuille flow and grooved microchannel flow. The slip velocity and temperature distribution are compared with results of DSMC or Maxwell slip condition and those are shown in good agreement.

  3. Imbricated slip rate processes during slow slip transients imaged by low-frequency earthquakes

    Science.gov (United States)

    Lengliné, O.; Frank, W. B.; Marsan, D.; Ampuero, J.-P.

    2017-10-01

    Low Frequency Earthquakes (LFEs) often occur in conjunction with transient strain episodes, or Slow Slip Events (SSEs), in subduction zones. Their focal mechanism and location consistent with shear failure on the plate interface argue for a model where LFEs are discrete dynamic ruptures in an otherwise slowly slipping interface. SSEs are mostly observed by surface geodetic instruments with limited resolution and it is likely that only the largest ones are detected. The time synchronization of LFEs and SSEs suggests that we could use the recorded LFEs to constrain the evolution of SSEs, and notably of the geodetically-undetected small ones. However, inferring slow slip rate from the temporal evolution of LFE activity is complicated by the strong temporal clustering of LFEs. Here we apply dedicated statistical tools to retrieve the temporal evolution of SSE slip rates from the time history of LFE occurrences in two subduction zones, Mexico and Cascadia, and in the deep portion of the San Andreas fault at Parkfield. We find temporal characteristics of LFEs that are similar across these three different regions. The longer term episodic slip transients present in these datasets show a slip rate decay with time after the passage of the SSE front possibly as t - 1 / 4. They are composed of multiple short term transients with steeper slip rate decay as t-α with α between 1.4 and 2. We also find that the maximum slip rate of SSEs has a continuous distribution. Our results indicate that creeping faults host intermittent deformation at various scales resulting from the imbricated occurrence of numerous slow slip events of various amplitudes.

  4. Cool and luminous transients from mass-losing binary stars

    Science.gov (United States)

    Pejcha, Ondřej; Metzger, Brian D.; Tomida, Kengo

    2016-02-01

    We study transients produced by equatorial disc-like outflows from catastrophically mass-losing binary stars with an asymptotic velocity and energy deposition rate near the inner edge which are proportional to the binary escape velocity vesc. As a test case, we present the first smoothed-particle radiation-hydrodynamics calculations of the mass loss from the outer Lagrange point with realistic equation of state and opacities. The resulting spiral stream becomes unbound for binary mass ratios 0.06 ≲ q ≲ 0.8. For synchronous binaries with non-degenerate components, the spiral-stream arms merge at a radius of ˜10a, where a is the binary semi-major axis, and the accompanying shock thermalizes about 10 per cent of the kinetic power of the outflow. The mass-losing binary outflows produce luminosities reaching up to ˜106 L⊙ and effective temperatures spanning 500 ≲ Teff ≲ 6000 K, which is compatible with many of the class of recently discovered red transients such as V838 Mon and V1309 Sco. Dust readily forms in the outflow, potentially in a catastrophic global cooling transition. The appearance of the transient is viewing angle-dependent due to vastly different optical depths parallel and perpendicular to the binary plane. We predict a correlation between the peak luminosity and the outflow velocity, which is roughly obeyed by the known red transients. Outflows from mass-losing binaries can produce luminous (105 L⊙) and cool (Teff ≲ 1500 K) transients lasting a year or longer, as has potentially been detected by Spitzer surveys of nearby galaxies.

  5. Energy balance in obesity.

    Science.gov (United States)

    Webber, Jonathan

    2003-05-01

    The current epidemic of human obesity implies that whilst energy balance appears to be regulated, the extent of this regulatory process is being overwhelmed in large numbers of the population by environmental changes. Clearly, the shift towards positive energy balance reflects both alterations in energy intake and decreases in physical activity. Increased energy intake and, in particular, the rising proportion of energy from fat is linked with obesity. However, on a population level reduced levels of activity probably play the predominant role. It is apparent that individual susceptibility to weight gain varies enormously. The factors underlying this susceptibility are an area of intense research interest. Variations in BMR from that predicted appear to be linked to the propensity to gain weight. The genes responsible for this variation may include uncoupling proteins-2 and -3, with a number of studies showing a link with obesity. However, in vivo studies of these proteins have not yet demonstrated a physiological role for them that would explain the link with obesity. Non-exercise activity thermogenesis may also protect from weight gain, but the regulation of this type of thermogenesis is unclear, although the sympathetic nervous system may be important. A profusion of hormones, cytokines and neurotransmitters is involved in regulating energy intake, but whilst mutations in leptin and the melanocortin-3 receptor are responsible for rare monogenic forms of obesity, their wider role in common polygenic obesity is not known. Much current work is directed at examining the interplay between genetic background and environmental factors, in particular diet, that both lead to positive energy balance and seem to make it so hard for many obese subjects to lose weight.

  6. 'At Least I Didn't Lose Money'

    DEFF Research Database (Denmark)

    Stephens, Thomas Alexander; Tyran, Jean-Robert Karl

    (monetary) values. Real losses may therefore loom larger in people’s minds when they lose money than when real losses are hidden by purely nominal gains. Using a survey experiment with a large and heterogeneous sample, we show that evaluations of housing transactions are systematically biased by purely......Loss aversion is one of the most robust findings to have emerged from behavioral economics. Surprisingly little attention, however, has been devoted to nominal loss aversion, the interaction of loss aversion and money illusion. People tend to think of transactions in terms of their nominal...

  7. Protein losing enteropathy secondary to a pulmonary artery stent

    Directory of Open Access Journals (Sweden)

    Narayanswami Sreeram

    2012-01-01

    Full Text Available A 2-year-old patient with hypoplastic left heart syndrome presented 6 months following Fontan completion with protein-losing enteropathy (PLE. He had undergone stent implantation in the left pulmonary artery after the Norwood procedure, followed by redilation of the stent prior to Fontan completion. Combined bronchoscopic and catheterization studies during spontaneous breathing confirmed left bronchial stenosis behind the stent, and diastolic systemic ventricular pressure during expiration of 25 mm Hg. We postulate that the stent acts as a valve, against which the patient generates high expiratory pressures, which are reflected in the ventricular diastolic pressure. This may be the cause of PLE.

  8. Losing the boxes: fragmentation as a source of system complexity

    CSIR Research Space (South Africa)

    Baumbach, J

    2015-09-01

    Full Text Available stream_source_info Baumbach2_2015_ABSTRACT.pdf.txt stream_content_type text/plain stream_size 856 Content-Encoding UTF-8 stream_name Baumbach2_2015_ABSTRACT.pdf.txt Content-Type text/plain; charset=UTF-8 Losing the Boxes...: Fragmentation as a Source of System Complexity Johannes Baumbach, André Marais, Dr Duarte P. Gonçalves Council for Scientific and Industrial Research (CSIR) P.O Box 395 Pretoria, South Africa 0001 Abstract. Despite the advances in mature engineering...

  9. The Distribution of Fault Slip Rates and Oblique Slip Patterns in the Greater Los Angeles, CA Region

    Science.gov (United States)

    Harper, H.; Marshall, S. T.

    2014-12-01

    The Los Angeles basin is host to a complex network of active strike-slip, reverse, and oblique slip faults. Because of the large metropolitan region occupying the basin, even moderately large earthquakes (M6+) pose a significant natural hazard. Since geologic estimates have not fully characterized the distribution of active fault slip rates in the region, we use a mechanical model driven by geodetically-measured shortening rates to calculate the full three-dimensional fault slip rate distributions in the region. The modeled nonplanar fault geometries are relatively well-constrained, and use data from the SCEC community fault model. Area-weighted average fault slip rates predicted by the model match previously measured geologic slip rates in most cases; however, some geologic measurements were made in locations where the slip rate is non-characteristic of the fault (e.g. near a fault tip) and the geologic slip rate estimate disagrees with the model-predicted average slip rate. The largest discrepancy between the model predictions and geologic estimates occurs on the Sierra Madre fault, which has a model-predicted slip rate approximately 2 mm/yr greater than the geologic estimates. An advantage of the model is that it can predict the full three-dimensional mechanically compatible slip distribution along all modeled faults. The fault surface slip distribution maps show complex oblique slip patterns that arise due to the nonplanar geometries and mechanical interactions between intersecting and neighboring faults. For example, the Hollywood fault exhibits a net slip of 0.7 mm/yr at depth which increases to 1.6 mm/yr where it is intersected by the Santa Monica fault in the near-surface. Model results suggest that nearly all faults in the region have an oblique component of slip at depth, so slip rate estimates of only dip or strike-slip may underestimate the total net slip rates and seismic hazards in the region.

  10. Game related statistics which discriminate between winning and losing under-16 male basketball games.

    Science.gov (United States)

    Lorenzo, Alberto; Gómez, Miguel Ángel; Ortega, Enrique; Ibáñez, Sergio José; Sampaio, Jaime

    2010-01-01

    The aim of the present study was to identify the game-related statistics which discriminate between winning and losing teams in under-16 years old male basketball games. The sample gathered all 122 games in the 2004 and 2005 Under-16 European Championships. The game-related statistics analysed were the free-throws (both successful and unsuccessful), 2- and 3-points field-goals (both successful and unsuccessful) offensive and defensive rebounds, blocks, assists, fouls, turnovers and steals. The winning teams exhibited lower ball possessions per game and better offensive and defensive efficacy coefficients than the losing teams. Results from discriminant analysis were statistically significant and allowed to emphasize several structure coefficients (SC). In close games (final score differences below 9 points), the discriminant variables were the turnovers (SC = -0.47) and the assists (SC = 0.33). In balanced games (final score differences between 10 and 29 points), the variables that discriminated between the groups were the successful 2-point field-goals (SC = -0.34) and defensive rebounds (SC = -0. 36); and in unbalanced games (final score differences above 30 points) the variables that best discriminated both groups were the successful 2-point field-goals (SC = 0.37). These results allowed understanding that these players' specific characteristics result in a different game-related statistical profile and helped to point out the importance of the perceptive and decision making process in practice and in competition. Key pointsThe players' game-related statistical profile varied according to game type, game outcome and in formative categories in basketball.The results of this work help to point out the different player's performance described in U-16 men's basketball teams compared with senior and professional men's basketball teams.The results obtained enhance the importance of the perceptive and decision making process in practice and in competition.

  11. Balance Problems

    Science.gov (United States)

    ... fall may affect an older adult's life. BPPV (Benign Paroxysmal Positional Vertigo) There are many types of balance disorders. One of the most common is benign paroxysmal positional vertigo, or BPPV. In BPPV, you experience a brief, ...

  12. Hydrodynamic slip length as a surface property

    Science.gov (United States)

    Ramos-Alvarado, Bladimir; Kumar, Satish; Peterson, G. P.

    2016-02-01

    Equilibrium and nonequilibrium molecular dynamics simulations were conducted in order to evaluate the hypothesis that the hydrodynamic slip length is a surface property. The system under investigation was water confined between two graphite layers to form nanochannels of different sizes (3-8 nm). The water-carbon interaction potential was calibrated by matching wettability experiments of graphitic-carbon surfaces free of airborne hydrocarbon contamination. Three equilibrium theories were used to calculate the hydrodynamic slip length. It was found that one of the recently reported equilibrium theories for the calculation of the slip length featured confinement effects, while the others resulted in calculations significantly hindered by the large margin of error observed between independent simulations. The hydrodynamic slip length was found to be channel-size independent using equilibrium calculations, i.e., suggesting a consistency with the definition of a surface property, for 5-nm channels and larger. The analysis of the individual trajectories of liquid particles revealed that the reason for observing confinement effects in 3-nm nanochannels is the high mobility of the bulk particles. Nonequilibrium calculations were not consistently affected by size but by noisiness in the smallest systems.

  13. Hydrodynamic slip length as a surface property.

    Science.gov (United States)

    Ramos-Alvarado, Bladimir; Kumar, Satish; Peterson, G P

    2016-02-01

    Equilibrium and nonequilibrium molecular dynamics simulations were conducted in order to evaluate the hypothesis that the hydrodynamic slip length is a surface property. The system under investigation was water confined between two graphite layers to form nanochannels of different sizes (3-8 nm). The water-carbon interaction potential was calibrated by matching wettability experiments of graphitic-carbon surfaces free of airborne hydrocarbon contamination. Three equilibrium theories were used to calculate the hydrodynamic slip length. It was found that one of the recently reported equilibrium theories for the calculation of the slip length featured confinement effects, while the others resulted in calculations significantly hindered by the large margin of error observed between independent simulations. The hydrodynamic slip length was found to be channel-size independent using equilibrium calculations, i.e., suggesting a consistency with the definition of a surface property, for 5-nm channels and larger. The analysis of the individual trajectories of liquid particles revealed that the reason for observing confinement effects in 3-nm nanochannels is the high mobility of the bulk particles. Nonequilibrium calculations were not consistently affected by size but by noisiness in the smallest systems.

  14. Self-consistent dynamics of wall slip

    NARCIS (Netherlands)

    Dubbeldam, J.L.A.; Molenaar, J.

    2003-01-01

    A simple molecular model is studied to explain wall slip in a polymer melt. We consider a tube model for tethered chains in which the most important relaxation mechanisms: convective constraint release and chain stretching (retraction), are incorporated. Furthermore, we take the interactions between

  15. Disseminated Langerhans' cell histiocytosis and massive protein-losing enteropathy

    Directory of Open Access Journals (Sweden)

    Santos-Machado T.M.

    1999-01-01

    Full Text Available Symptomatic involvement of the gastrointestinal (GI tract as a prominent symptom in Langerhans' cell histiocytosis (LCH is uncommon, occurring in less than 1 to 5% of all cases, even when the disease is in its disseminated form. Up to now, there have been reports of 18 cases of LCH with GI manifestations, including our 2 cases, with diarrhea (77.7%, protein-losing enteropathy (33.3% and bloody stool being the most frequent findings. The authors present two patients with severe diarrhea and refractory hypoalbuminemia, and with the protein-losing enteropathy documented by Cr51-labeled albumin studies. A review of the literature indicated that the presence of GI symptoms is often associated with systemic disease as well as with poor prognosis, mainly under 2 years of age. Radioisotopes are useful for documenting protein loss in several diseases with high specificity and sensitivity, and their utilization in the cases reviewed here permitted diagnoses in 6 children, as well as improved therapeutic management.

  16. Cool and Luminous Transients from Mass-Losing Binary Stars

    CERN Document Server

    Pejcha, Ondrej; Tomida, Kengo

    2015-01-01

    We study transients produced by equatorial disk-like outflows from catastrophically mass-losing binary stars with an asymptotic velocity and energy deposition rate near the inner edge which are proportional to the binary escape velocity v_esc. As a test case, we present the first smoothed-particle radiation-hydrodynamics calculations of the mass loss from the outer Lagrange point with realistic equation of state and opacities. The resulting spiral stream becomes unbound for binary mass ratios 0.06 < q < 0.8. For synchronous binaries with non-degenerate components, the spiral-stream arms merge at a radius of ~10a, where a is the binary semi-major axis, and the accompanying shock thermalizes 10-20% of the kinetic power of the outflow. The mass-losing binary outflows produce luminosities proportional to the mass loss rate and v_esc, reaching up to ~10^6 L_Sun. The effective temperatures depend primarily on v_esc and span 500 < T_eff < 6000 K. Dust readily forms in the outflow, potentially in a catast...

  17. Next generation GNSS single receiver cycle slip reliability

    NARCIS (Netherlands)

    Teunissen, P.J.G.; De Bakker, P.F.

    2009-01-01

    In this contribution we study the multi-frequency, carrier-phase slip detection capabilities of a single receiver. Our analysis is based on an analytical expression that we present for themulti-frequencyminimal detectable carrier phase cycle slip.

  18. Effects of mental fatigue on biomechanics of slips.

    Science.gov (United States)

    Lew, Fui Ling; Qu, Xingda

    2014-01-01

    The objective of this study was to investigate the effects of mental fatigue on biomechanics of slips. A total of 44 healthy young participants were evenly categorised into two groups: no fatigue and mental fatigue. Mental fatigue was induced by performing an AX-continuous performance test. The participants in both groups were instructed to walk on a linear walkway, and slips were induced unexpectedly during walking. We found that mental fatigue has adverse effects in all the three phases of slips. In particular, it leads to increased likelihood of slip initiation, poorer slip detection and a more insufficient reactive recovery response to slips. Based on the findings from the present study, we can conclude that mental fatigue is a risk factor for slips and falls. In order to prevent slip-induced falls, interventions, such as providing frequent rest breaks, could be applied in the workplace to avoid prolonged exposures to cognitively demanding activities.

  19. Flexural-slip during visco-elastic buckle folding

    Science.gov (United States)

    Damasceno, Davi R.; Eckert, Andreas; Liu, Xiaolong

    2017-07-01

    Flexural-slip is considered as an important mechanism during folding and a general conceptual and qualitative understanding has been provided by various field studies. However, quantitative evidence of the importance of the flexural-slip mechanism during fold evolution is sparse due to the lack of suitable strain markers. In this study, 2D finite element analysis is used to overcome these disadvantages and to simulate flexural-slip during visco-elastic buckle folding. Variations of single and multilayer layer fold configurations are investigated, showing that flexural-slip is most likely to occur in effective single layer buckle folds, where slip occurs between contacts of competent layers. Based on effective single layer buckle folds, the influence of the number of slip surfaces, the degree of mechanical coupling (based on the friction coefficient), and layer thickness, on the resulting slip distribution are investigated. The results are in agreement with the conceptual flexural-slip model and show that slip is initiated sequentially during the deformation history and is maximum along the central slip surface of the fold limb. The cumulative amount of slip increases as the number of slip surfaces is increased. For a lower degree of mechanical coupling increased slip results in different fold shapes, such as box folds, during buckling. In comparison with laboratory experiments, geometrical relationships and field observations, the numerical modeling results show similar slip magnitudes. It is concluded that flexural-slip should represent a significant contribution during buckle folding, affecting the resulting fold shape for increased amounts of slip.

  20. Characterization of slip lines in single edge notched tension specimens

    OpenAIRE

    Van Gerven, Filip; De Waele, Wim; Belato Rosado, Diego; Hertelé, Stijn

    2015-01-01

    The application of slip line analysis in weld failure assessment has not gained much attention to date. The presented research aims to predict slip line patterns taking into account the complex heterogeneous structure of the weld. A preliminary study based on Single Edge Notched Tension (SENT) test results sampling pure base material, i.e. not containing any welds is conducted to assess the impact of side grooves on slip line behaviour and to validate slip line theory and finite element analy...

  1. Evidence for Truncated Exponential Probability Distribution of Earthquake Slip

    KAUST Repository

    Thingbaijam, Kiran K. S.

    2016-07-13

    Earthquake ruptures comprise spatially varying slip on the fault surface, where slip represents the displacement discontinuity between the two sides of the rupture plane. In this study, we analyze the probability distribution of coseismic slip, which provides important information to better understand earthquake source physics. Although the probability distribution of slip is crucial for generating realistic rupture scenarios for simulation-based seismic and tsunami-hazard analysis, the statistical properties of earthquake slip have received limited attention so far. Here, we use the online database of earthquake source models (SRCMOD) to show that the probability distribution of slip follows the truncated exponential law. This law agrees with rupture-specific physical constraints limiting the maximum possible slip on the fault, similar to physical constraints on maximum earthquake magnitudes.We show the parameters of the best-fitting truncated exponential distribution scale with average coseismic slip. This scaling property reflects the control of the underlying stress distribution and fault strength on the rupture dimensions, which determines the average slip. Thus, the scale-dependent behavior of slip heterogeneity is captured by the probability distribution of slip. We conclude that the truncated exponential law accurately quantifies coseismic slip distribution and therefore allows for more realistic modeling of rupture scenarios. © 2016, Seismological Society of America. All rights reserverd.

  2. Optimization of Partial Slip Surface at Lubricated-MEMS

    NARCIS (Netherlands)

    Tauviqirrahman, M.; Ismail, R.; Schipper, D.J.; Jamari, J.; Suprijanto, Dr.

    2011-01-01

    This work reports the hydrodynamic performance (load support, friction force, friction coefficient, and volume flow) generated by a partial slip surface at lubricated-MEMS. The partial slip surface is optimized so that a maximum hydrodynamic load support could be obtained. The partial slip is applie

  3. Collagenous Colitis Associated with Protein Losing Enteropathy in a Toddler

    Directory of Open Access Journals (Sweden)

    Osama F. Almadhoun

    2014-01-01

    Full Text Available Collagenous mucosal inflammatory disease is a rare gastrointestinal disorder that involves the columnar lining of gastric and intestinal mucosa and is characterized by a distinct subepithelial collagen deposition. Recent clinical and pathological evidence have indicated that collagenous mucosal inflammatory disease can be extensive disease that may concomitantly involve several gastrointestinal sites at the same time. This entity, however, occurs infrequently in children. It is even less common to find concomitant depositions of collagen in the mucosa of gastrointestinal sites other than the colon. Only two cases in pediatric literature reported concomitant involvement, one with gastric and colonic involvement and the other one with gastroduodenocolitis. We are reporting a 15-month-old boy who presented with severe diarrhea and diffuse edema secondary to hypoalbuminemia. Further testing documented protein losing enteropathy (PLE associated with collagenous colitis.

  4. Who will benefit and who will lose from Obamacare?

    Directory of Open Access Journals (Sweden)

    Mathew M

    2013-08-01

    Full Text Available No abstract available. Article truncated at 150 words. The debate continues over the Patient Protection and Affordable Care Act (ACA, Obamacare (1. One the one hand the White House and their Democratic supporters say the law will: 1. Expand coverage to the poor; 2. Control costs; and 3. Improve care. On the other hand, opponents say the law is a job killer. Employers will be forced to eliminate positions, or reduce staffers to part-time hours to save costs. A recent article stated that Obamacare is certain to create a number of new positions but that seemed to be only part of the story (2. Below we offer our short lists of who will benefit and who will lose under Obamacare. Who Will Benefit 1.Uninsured patients. Many patients who are uninsured or underinsured will benefit because their lack of health insurance results in delays in diagnosis and treatment. Uninsured patients often seek care in the hospital emergency department…

  5. Phase Slips in Oscillatory Hair Bundles

    Science.gov (United States)

    Roongthumskul, Yuttana; Shlomovitz, Roie; Bruinsma, Robijn; Bozovic, Dolores

    2013-01-01

    Hair cells of the inner ear contain an active amplifier that allows them to detect extremely weak signals. As one of the manifestations of an active process, spontaneous oscillations arise in fluid immersed hair bundles of in vitro preparations of selected auditory and vestibular organs. We measure the phase-locking dynamics of oscillatory bundles exposed to low-amplitude sinusoidal signals, a transition that can be described by a saddle-node bifurcation on an invariant circle. The transition is characterized by the occurrence of phase slips, at a rate that is dependent on the amplitude and detuning of the applied drive. The resultant staircase structure in the phase of the oscillation can be described by the stochastic Adler equation, which reproduces the statistics of phase slip production. PMID:25167040

  6. Surface slip during large Owens Valley earthquakes

    KAUST Repository

    Haddon, E. K.

    2016-01-10

    The 1872 Owens Valley earthquake is the third largest known historical earthquake in California. Relatively sparse field data and a complex rupture trace, however, inhibited attempts to fully resolve the slip distribution and reconcile the total moment release. We present a new, comprehensive record of surface slip based on lidar and field investigation, documenting 162 new measurements of laterally and vertically displaced landforms for 1872 and prehistoric Owens Valley earthquakes. Our lidar analysis uses a newly developed analytical tool to measure fault slip based on cross-correlation of sublinear topographic features and to produce a uniquely shaped probability density function (PDF) for each measurement. Stacking PDFs along strike to form cumulative offset probability distribution plots (COPDs) highlights common values corresponding to single and multiple-event displacements. Lateral offsets for 1872 vary systematically from approximate to 1.0 to 6.0 m and average 3.31.1 m (2 sigma). Vertical offsets are predominantly east-down between approximate to 0.1 and 2.4 m, with a mean of 0.80.5 m. The average lateral-to-vertical ratio compiled at specific sites is approximate to 6:1. Summing displacements across subparallel, overlapping rupture traces implies a maximum of 7-11 m and net average of 4.41.5 m, corresponding to a geologic M-w approximate to 7.5 for the 1872 event. We attribute progressively higher-offset lateral COPD peaks at 7.12.0 m, 12.8 +/- 1.5 m, and 16.6 +/- 1.4 m to three earlier large surface ruptures. Evaluating cumulative displacements in context with previously dated landforms in Owens Valley suggests relatively modest rates of fault slip, averaging between approximate to 0.6 and 1.6 mm/yr (1 sigma) over the late Quaternary.

  7. On the mechanism of cross slip in Ni3Al

    Science.gov (United States)

    Milligan, Walter W.; Antolovich, Stephen D.

    1989-01-01

    The mechanical properties of L1(2) intermetallic alloys have been previously described by models based on the assumption that cube cross slip is the rate-limiting step. In this study, it was demonstrated that the cube cross-slip event must be reversible under a change in loading direction. This observation allows the cross-slip models to remain consistent with cyclic deformation data. Additionally, this observation was used as a critical test of the available cross-slip models. It was demonstrated that the rate-limiting step cannot be a total cross-slip event, in which both a/2 110-line superpartial dislocations cross slip to the cube plane. Conversely, the limited cross-slip event proposed by Paidar et al. (1984), was demonstrated to be consistent with the reversibility constraint. This lends additional experimental support to this model.

  8. Behaviors of small heterogeneity controlled by surrounding aseismic slip

    Science.gov (United States)

    Aochi, Hideo; Ide, Satoshi

    2017-04-01

    Numerical simulations of slow slip events on a fault interface characterized by multi-scale heterogeneity (fractal patch model; Ide and Aochi, JGR, 2005; Ide, Proc. Jpn Acad. Ser. B, 2014) are carried out, supposing that characteristic distance in the slip-dependent frictional law is scale-dependent. We also consider slip-dependent stress accumulation on patches prior to the weakening process. Slip on small patches is enhanced significantly when background is releasing stress in the case of two patches model. Slip behaviors becomes complex when fractal patch model is considered. It is then difficult to detect the accentuation of slips on small patches. On the other hand, they are quiet (detectable statistically) when background slip is characterized by strengthening process.

  9. Balancing device

    NARCIS (Netherlands)

    Van Dorsser, W.D.; Herder, J.L.; Wisse B.M.; Barents, R.

    2007-01-01

    The invention relates to a balancing device for a mass, comprising an arm that is adjustable about a pivoting point and with which the mass is coupled, and an adjustable spring system that is coupled with the arm, which spring system comprises at least one spring, wherein the spring system comprises

  10. Balancing Audio

    DEFF Research Database (Denmark)

    Walther-Hansen, Mads

    2016-01-01

    is not thoroughly understood. In this paper I treat balance as a metaphor that we use to reason about several different actions in music production, such as adjusting levels, editing the frequency spectrum or the spatiality of the recording. This study is based on an exploration of a linguistic corpus of sound...

  11. Effective slip for flow in a rotating channel bounded by stick-slip walls

    Science.gov (United States)

    Ng, Chiu-On

    2016-12-01

    This paper aims to look into how system rotation may modify the role played by boundary slip in controlling flow through a rotating channel bounded by stick-slip walls. A semianalytical model is developed for pressure-driven flow in a slit channel that rotates about an axis perpendicular to its walls, which are superhydrophobic surfaces patterned with periodic alternating no-shear and no-slip stripes. The cases where the flow is driven by a pressure gradient parallel or normal to the stripes are considered. The effects of the no-shear area fraction on the velocities and effective slip lengths for the primary and secondary flows are investigated as functions of the rotation rate and the channel height. It is mathematically proved that the secondary flow rate is exactly the same in the two cases, irrespective of whether the primary flow is parallel or normal to the wall stripes. For any rotation speed, there is an optimal value of the no-shear area fraction at which the primary flow rate is maximum. This is a consequence of two competing effects: the no-shear part of the wall may serve to reduce the wall resistance, thereby enhancing the flow especially at low rotation, but it also weakens the formation of the near-wall Ekman layer, which is responsible for pumping the flow especially at high rotation. Wall slip in a rotating environment is to affect flow in the Ekman layer, but not flow in the geostrophic core.

  12. Suppression of strike-slip fault systems

    Science.gov (United States)

    Curren, I. S.

    2012-12-01

    In orogens elongated parallel to a great circle about the Euler pole for the two bounding plates, theory requires simple-shear deformation in the form of distributed deformation or velocity discontinuities across strike-slip faults. This type of deformation, however, does not develop at all plate boundaries requiring toroidal motion. Using the global plate boundary model, PB2002 [Bird, 2003], as the basis for identifying areas where expected simple-shear deformation is absent or underdeveloped, it was also possible to identify two potential causes for this behavior: (1) the presence of extensive fracturing at right angles to the shear plane and (2) regional cover of flood basalts or andesites with columnar joints. To test this hypothesis, a new plane-stress finite-strain model was developed to study the effects of such pre-existing structures on the development of simple shear in a clay cake. A homogenous kaolinite-water mixture was poured into a deforming parallelogram box and partially dried to allow for brittle and plastic deformation at and below the surface of the clay, respectively. This was floated on a dense fluid foundation, effectively removing basal friction, and driven by a motor in a sinistral direction from the sides of the box. Control experiments produced classic Riedel model fault assemblages and discrete, through-going primary deformation zones (PDZs); experiments with pre-existing structures developed the same, though subdued and distributed, fault assemblages but did not develop through-going PDZs. Although formation of strike-slip faults was underdeveloped at the surface in clay with pre-existing structures, offset within the clay cake (measured, with respect to a fixed point, by markers on the clay surface) as a fraction of total offset of the box was consistently larger than that of the control experiments. This suggests that while the extent of surface faulting was lessened in clay with pre-existing structures, slip was still occurring at

  13. Balance (or Vestibular) Rehabilitation

    Science.gov (United States)

    ... the Public / Hearing and Balance Balance (or Vestibular) Rehabilitation Audiologic (hearing), balance, and medical diagnostic tests help ... whether you are a candidate for vestibular (balance) rehabilitation. Vestibular rehabilitation is an individualized balance retraining exercise ...

  14. Boundary conditions for fluids with internal orientational degrees of freedom: apparent velocity slip associated with the molecular alignment.

    Science.gov (United States)

    Heidenreich, Sebastian; Ilg, Patrick; Hess, Siegfried

    2007-06-01

    Boundary effects are investigated for fluids with internal orientational degrees of freedom such as molecular liquids, thermotropic and lyotropic liquid crystals, and polymeric fluids. The orientational degrees of freedom are described by the second rank alignment tensor which is related to the birefringence. We use a standard model to describe the orientational dynamics in the presence of flow, the momentum balance equations, and a constitutive law for the pressure tensor to describe our system. In the spirit of irreversible thermodynamics, boundary conditions are formulated for the mechanical slip velocity and the flux of the alignment. They are set up such that the entropy production at the wall inferred from the entropy flux is positive definite. Even in the absence of a true mechanical slip, the coupling between orientation and flow leads to flow profiles with an apparent slip. This has consequences for the macroscopically measurable effective velocity. In analytical investigations, we consider the simplified case of an isotropic fluid in the Newtonian and stationary flow regime. For special geometries such as plane and cylindrical Couette flow, plane Poiseuille flow, and a flow down an inclined plane, we demonstrate explicitly how the boundary conditions lead to an apparent slip. Furthermore, we discuss the dependence of the effective viscosity and of the effective slip length on the model parameters.

  15. Nonlinear contact between pipeline's outer wall and slip-on buckle arrestor's inner wall during buckling process

    Science.gov (United States)

    Ma, Weilin; Liu, Jiande; Dong, Sheng; Zhang, Xin; Ma, Xiaozhou

    2017-02-01

    In order to theoretically study the buckle propagation of subsea pipelines with slip-on buckle arrestors, a two-dimensional ring model was set up to represent the pipeline and a nonlinear spring model was adopted to simulate the contact between pipeline's inner walls and between pipeline's outer wall and slip-on buckle arrestor's inner wall during buckle propagation. In addition, some reverse springs are added to prevent the wall of left and right sides separating from the inner wall of slip-on buckle arrestors. Considering large deformation kinematics relations and the elastic-plastic constitutive relation of material, balance equations were established with the principle of virtual work. The variation of external pressure with respect to the cross-sectional area of pipelines was analyzed, and the lower bound of the crossover pressure of slip-on buckle arrestors was calculated based on Maxwell's energy balance method. By comparing the theoretical results with experiment and finite element numerical simulation, the theoretical method is proved to be correct and reliable.

  16. Balancing priorities

    DEFF Research Database (Denmark)

    Mønsted, Troels; Johansen, Andreas Kaas; Lauridsen, Frederik Vahr Bjarnø

    2016-01-01

    a heterogeneous ensemble of care providers. In this paper, we present findings from a field study of coordinative work in distributed elder care in Denmark. The purpose of this study is to further our understanding of the coordinative challenges of distributed elder care, and to inform design of new care......, that are needed by the healthcare system, but also the work involved in balancing priorities....

  17. Fault Scaling Relationships Depend on the Average Geological Slip Rate

    Science.gov (United States)

    Anderson, J. G.; Biasi, G. P.; Wesnousky, S. G.

    2016-12-01

    This study addresses whether knowing the geological slip rates on a fault in addition to the rupture length improves estimates of magnitude (Mw) of continental earthquakes that rupture the surface, based on a database of 80 events that includes 57 strike-slip, 12 reverse, and 11 normal faulting events. Three functional forms are tested to relate rupture length L to magnitude Mw: linear, bilinear, and a shape with constant static stress drop. The slip rate dependence is tested as a perturbation to the estimates of magnitude from rupture length. When the data are subdivided by fault mechanism, magnitude predictions from rupture length are improved for strike-slip faults when slip rate is included, but not for reverse or normal faults. This conclusion is robust, independent of the functional form used to relate L to Mw. Our preferred model is the constant stress drop model, because teleseismic observations of earthquakes favor that result. Because a dependence on slip rate is only significant for strike-slip events, a combined relationship for all rupture mechanisms is not appropriate. The observed effect of slip rate for strike-slip faults implies that the static stress drop, on average, tends to decrease as the fault slip rate increases.

  18. Progressive slippage after pinning for slipped capital femoral epiphysis.

    Science.gov (United States)

    Sanders, James O; Smith, William J; Stanley, Earl A; Bueche, Matthew J; Karol, Lori A; Chambers, Henry G

    2002-01-01

    The authors retrospectively reviewed seven cases of progressive slipped capital femoral epiphysis after screw fixation. All seven patients initially presented with chronic symptoms, and five had an acute exacerbation of symptoms with the appearance of an acute-on-chronic slip. Of the other two, one had obvious motion at the proximal femoral physis and the other had increased symptoms but did not have an obvious acute slip radiographically. All underwent percutaneous screw fixation. In four patients a single screw was placed, and in three patients two screws were placed. No patient became symptom-free after surgery. Slip progression was noted on average 5 months after treatment. Radiographs in all patients revealed an increase in slip severity and loss of screw purchase in the femoral neck while fixation in the proximal femoral epiphysis remained secure. One patient had hypothyroidism and another Cushing disease, both diagnosed after the slipped epiphysis. Slips occurring in children with underlying endocrinopathies, and unstable slips in children with a history of antecedent knee or hip pain (commonly called an acute-on-chronic slip) may be susceptible to screw fixation failure. In such patients, close radiographic follow-up, particularly in the presence of continued symptoms, is required to document slip progression and fixation failure as soon as possible.

  19. Coseismic slip distribution of the 1923 Kanto earthquake, Japan

    Science.gov (United States)

    Pollitz, F.F.; Nyst, M.; Nishimura, T.; Thatcher, W.

    2005-01-01

    The slip distribution associated with the 1923 M = 7.9 Kanto, Japan, earthquake is reexamined in light of new data and modeling. We utilize a combination of first-order triangulation, second-order triangulation, and leveling data in order to constrain the coseismic deformation. The second-order triangulation data, which have not been utilized in previous studies of 1923 coseismic deformation, are associated with only slightly smaller errors than the first-order triangulation data and expand the available triangulation data set by about a factor of 10. Interpretation of these data in terms of uniform-slip models in a companion study by Nyst et al. shows that a model involving uniform coseismic slip on two distinct rupture planes explains the data very well and matches or exceeds the fit obtained by previous studies, even one which involved distributed slip. Using the geometry of the Nyst et al. two-plane slip model, we perform inversions of the same geodetic data set for distributed slip. Our preferred model of distributed slip on the Philippine Sea plate interface has a moment magnitude of 7.86. We find slip maxima of ???8-9 m beneath Odawara and ???7-8 m beneath the Miura peninsula, with a roughly 2:1 ratio of strike-slip to dip-slip motion, in agreement with a previous study. However, the Miura slip maximum is imaged as a more broadly extended feature in our study, with the high-slip region continuing from the Miura peninsula to the southern Boso peninsula region. The second-order triangulation data provide good evidence for ???3 m right-lateral strike slip on a 35-km-long splay structure occupying the volume between the upper surface of the descending Philippine Sea plate and the southern Boso peninsula. Copyright 2005 by the American Geophysical Union.

  20. Complicated Recurrence of Slip Events on a Uniform Circular Asperity

    Science.gov (United States)

    Kato, N.

    2012-12-01

    Numerical simulation of repeated occurrence of slip events on a fault patch (asperity) is conducted to understand the mechanism of irregularity of the events. Seismic and geodetic observations indicate that episodic seismic/aseismic slip events repeatedly occur at almost the same area. For instance, magnitude of about 4.8 earthquakes had repeatedly occurred at intervals of 4.7 to 6.7 years off Kamaishi, northern Honshu, Japan. Quasi-periodic recurrence of episodic aseismic slip events (slow earthquakes) was found at the Nankai subduction zone, southwestern Japan, the Cascadia subduction zone, North America, etc. The recurrence intervals and magnitudes of slip events in each sequence are not constant, but some variability exists. Some researchers suggested that the variation in aseismic slip rate around a patch of slip events causes variation of loading rate. This results in variation of recurrence intervals. In the present study, we focus on irregularity of recurrence of slip events that originates from dynamics of fault slip. A two-dimensional planar fault in an infinite elastic medium is considered. The fault is uniformly shear loaded at a constant rate, and frictional stress acting on the fault is assumed to obey a rate- and state-dependent friction (RSF) law. A circular patch of radius r with velocity-weakening frictional property is embedded on a fault with velocity-strengthening frictional property elsewhere. A numerical simulation is conducted by varying the characteristic slip distance L of the RSF law. The critical radius rc for occurrence of unstable slip can be defined, and rc is proportional to L. When r >> rc, seismic slip events (earthquakes) repeatedly occur at a constant time interval. When r is a little larger than rc, recurrence of slip events becomes complex. We observe a period-2 cycle of slip events, where large and small events alternately occur. The cycle becomes more complex as r approaches rc and finally aperiodic (chaotic) slip pattern

  1. Losing track of time through delayed body representations

    Directory of Open Access Journals (Sweden)

    Thomas Hans Fritz

    2015-04-01

    Full Text Available The ability to keep track of time is perceived as crucial in most human societies. However, to lose track of time may also serve an important social role, associated with recreational purpose. To this end a number of social technologies are employed, some of which may relate to a manipulation of time perception through a modulation of body representation. Here we investigated an influence of real-time or delayed videos of own-body representations on time perception in an experimental setup with virtual mirrors. Seventy participants were asked to either stay in the installation until they thought that a defined time (90 s had passed, or they were encouraged to stay in the installation as long as they wanted and after exiting were asked to estimate the duration of their stay. Results show that a modulation of body representation by time-delayed representations of the mirror-video displays influenced time perception. Furthermore, these time-delayed conditions were associated with a greater sense of arousal and intoxication. We suggest that feeding in references to the immediate past into working memory could be the underlying mental mechanism mediating the observed modulation of time perception. We argue that such an influence on time perception would probably not only be achieved visually, but might also work with acoustic references to the immediate past (e.g., with music.

  2. Marginal Zone Lymphoma Complicated by Protein Losing Enteropathy

    Directory of Open Access Journals (Sweden)

    Nadine Stanek

    2016-01-01

    Full Text Available Protein losing enteropathy (PLE refers to excessive intestinal protein loss, resulting in hypoalbuminemia. Underlying pathologies include conditions leading to either reduced intestinal barrier or lymphatic congestion. We describe the case of a patient with long-lasting diffuse abdominal problems and PLE. Repetitive endoscopies were normal with only minimal lymphangiectasia in biopsies. Further evaluations revealed an indolent marginal zone lymphoma with minor bone marrow infiltration. Monotherapy with rituximab decreased bone marrow infiltration of the lymphoma but did not relieve PLE. Additional treatments with steroids, octreotide, a diet devoid of long-chain fatty-acids, and parenteral nutrition did not prevent further clinical deterioration with marked weight loss (23 kg, further reduction in albumin concentrations (nadir 8 g/L, and a pronounced drop in performance status. Finally, immunochemotherapy with rituximab and bendamustine resulted in hematological remission and remarkable clinical improvement. 18 months after therapy the patient remains free of gastrointestinal complaints and has regained his body weight with normal albumin levels. We demonstrate a case of PLE secondary to indolent marginal zone lymphoma. No intestinal pathologies were detected, contrasting a severe and almost lethal clinical course. Immunochemotherapy relieved lymphoma and PLE, suggesting that a high suspicion of lymphoma is warranted in otherwise unexplained cases of PLE.

  3. Pathophysiology and clinical presentations of salt-losing tubulopathies.

    Science.gov (United States)

    Seyberth, Hannsjörg W

    2016-03-01

    At least three renal tubular segments are involved in the pathophysiology of salt-losing tubulopathies (SLTs). Whether the pathogenesis starts either in the thick ascending limb of the loop of Henle (TAL) or in the distal convoluted tubule (DCT), it is the function of the downstream-localized aldosterone sensitive distal tubule (ASDT) to contribute to the adaptation process. In isolated TAL defects (loop disorders) ASDT adaptation is supported by upregulation of DCT, whereas in DCT disorders the ASDT is complemented by upregulation of TAL function. This upregulation has a major impact on the clinical presentation of SLT patients. Taking into account both the symptoms and signs of primary tubular defect and of the secondary reactions of adaptation, a clinical diagnosis can be made that eventually leads to an appropriate therapy. In addition to salt wasting, as occurs in all SLTs, characteristic features of loop disorders are hypo- or isosthenuric polyuria and hypercalciuria, whereas characteristics of DCT disorders are hypokalemia and (symptomatic) hypomagnesemia. In both SLT categories, replacement of urinary losses is the primary goal of treatment. In loop disorders COX inhibitors are also recommended to mitigate polyuria, and in DCT disorders magnesium supplementation is essential for effective treatment. Of note, the combination of a salt- and potassium-rich diet together with an adequate fluid intake is always the basis of long-term treatment in all SLTs.

  4. Microbiota fingerprints lose individually identifying features over time.

    Science.gov (United States)

    Wilkins, David; Leung, Marcus H Y; Lee, Patrick K H

    2017-01-09

    Humans host individually unique skin microbiota, suggesting that microbiota traces transferred from skin to surfaces could serve as forensic markers analogous to fingerprints. While it is known that individuals leave identifiable microbiota traces on surfaces, it is not clear for how long these traces persist. Moreover, as skin and surface microbiota change with time, even persistent traces may lose their forensic potential as they would cease to resemble the microbiota of the person who left them. We followed skin and surface microbiota within households for four seasons to determine whether accurate microbiota-based matching of individuals to their households could be achieved across long time delays. While household surface microbiota traces could be matched to the correct occupant or occupants with 67% accuracy, accuracy decreased substantially when skin and surface samples were collected in different seasons, and particularly when surface samples were collected long after skin samples. Most OTUs persisted on skin or surfaces for less than one season, indicating that OTU loss was the major cause of decreased matching accuracy. OTUs that were more useful for individual identification persisted for less time and were less likely to be deposited from skin to surface, suggesting a trade-off between the longevity and identifying value of microbiota traces. While microbiota traces have potential forensic value, unlike fingerprints they are not static and may degrade in a way that preferentially erases features useful in identifying individuals.

  5. Towards a No-Lose Theorem for Naturalness

    CERN Document Server

    Curtin, David

    2015-01-01

    We derive a phenomenological no-lose theorem for naturalness up to the TeV scale, which applies when quantum corrections to the Higgs mass from top quarks are canceled by perturbative BSM particles (top partners) of similar multiplicity due to to some symmetry. Null results from LHC searches already seem to disfavor such partners if they are colored. Any partners with SM charges and ~TeV masses will be exhaustively probed by the LHC and a future 100 TeV collider. Therefore, we focus on neutral top partners. While these arise in Twin Higgs theories, we analyze neutral top partners as model-independently as possible using EFT and Simplified Model methods. We classify all perturbative neutral top partner structures in order to compute their irreducible low-energy signatures at proposed future lepton and hadron colliders, as well as the irreducible tunings suffered in each scenario. Central to our theorem is the assumption that SM-charged BSM states appear in the UV completion of neutral naturalness, which is the...

  6. Indemnification: Win/lose or win/win

    Energy Technology Data Exchange (ETDEWEB)

    Booth, G.M.

    1996-08-01

    Some of you may be wondering how an oil company employee came to be speaking on indemnity. I`ve been wondering that myself and have even considered the possibility that the conference thought it might be interesting to have a presentation in which the sacrificial lamb is led to the slaughter. I hope that`s not the case. I am not speaking today as a representative of Conoco or as a spokesperson for the operator perspective. I do not intend to tell you what position to take with respect to contractual indemnification. My purpose is to share with you some of my thoughts on indemnification and provide you with some perspective in which to consider your own objectives in structuring indemnities and evaluate whether your current positions meet those objectives. What is contractual indemnification? To some, it is a vehicle by which to transfer all the risk inherent in their operations to another party. Others view it as a means of protecting a deductible or self-insured retention. Some think of it as a bloodbath. There are a few who believe that it is a game in which the only way to win is to ensure the other party loses. The states of Texas and Louisiana believe contractual indemnities are {open_quotes}inequities foisted on certain contractors.{close_quotes} I would like to propose that indemnity can be nothing more than an economic transaction which attempts to allocate risk in a cost effective manner.

  7. DEM simulation of growth normal fault slip

    Science.gov (United States)

    Chu, Sheng-Shin; Lin, Ming-Lang; Nien, Wie-Tung; Chan, Pei-Chen

    2014-05-01

    Slip of the fault can cause deformation of shallower soil layers and lead to the destruction of infrastructures. Shanchiao fault on the west side of the Taipei basin is categorized. The activities of Shanchiao fault will cause the quaternary sediments underneath the Taipei basin to become deformed. This will cause damage to structures, traffic construction, and utility lines within the area. It is determined from data of geological drilling and dating, Shanchiao fault has growth fault. In experiment, a sand box model was built with non-cohesive sand soil to simulate the existence of growth fault in Shanchiao Fault and forecast the effect on scope of shear band development and ground differential deformation. The results of the experiment showed that when a normal fault containing growth fault, at the offset of base rock the shear band will develop upward along with the weak side of shear band of the original topped soil layer, and this shear band will develop to surface much faster than that of single top layer. The offset ratio (basement slip / lower top soil thickness) required is only about 1/3 of that of single cover soil layer. In this research, it is tried to conduct numerical simulation of sand box experiment with a Discrete Element Method program, PFC2D, to simulate the upper covering sand layer shear band development pace and scope of normal growth fault slip. Results of simulation indicated, it is very close to the outcome of sand box experiment. It can be extended to application in water pipeline project design around fault zone in the future. Keywords: Taipei Basin, Shanchiao fault, growth fault, PFC2D

  8. Boundary Slip and Surface Interaction: A Lattice Boltzmann Simulation

    Institute of Scientific and Technical Information of China (English)

    CHEN Yan-Yan; YI Hou-Hui; LI Hua-Bing

    2008-01-01

    The factors affecting slip length in Couette geometry flows are analysed by means of a two-phase mesoscopic lattice Boltzmann model including non-ideal fluid-fluid and fluid-wall interactions.The main factors influencing the boundary slip are the strength of interactions between fluid-fluid and fluid-wall particles.Other factors,such as fluid viscosity,bulk pressure may also change the slip length.We find that boundary slip only occurs under a certain density(bulk pressure).If the density is large enough,the slip length will tend to zero.In our simulations,a low density layer near the wall does not need to be postulated a priori but emerges naturally from the underlying non-ideal mesoscopic dynamics.It is the low density layer that induces the boundary slip.The results may be helpful to understand recent experimental observations on the slippage of micro flows.

  9. Closed central slip injuries--a missed diagnosis?

    LENUS (Irish Health Repository)

    Nugent, N

    2011-09-01

    The extensor apparatus of the finger is a complex structure and injury can lead to significant digital dysfunction. Closed central slip injuries may be missed or diagnosis delayed because of lack of an open wound and often no radiographic abnormality, and can result in boutonniere deformities if untreated. This study aimed to quantify the number of patients attending with closed central slip injuries and to ascertain if the initial diagnosis was correct. The number of patients presenting to us over a 6 month period was recorded. The original diagnosis, time to diagnosis of central slip injury and the presence\\/absence of a boutonniere deformity were recorded. Ten patients were included in the study. Seven (70%) injuries were due to sport. Eight (80%) had a delayed diagnosis of central slip injury. Six (60%) had previously presented to general practitioners or emergency departments. Seven (70%) had boutonniere deformities. Closed central slip injuries can be missed. Simple clinical tests can diagnose central slip disruption.

  10. Slip-deficit on the Levant fault estimated by paleoseismological investigations

    Science.gov (United States)

    Lefevre, Marthe; Klinger, Yann; Al-Qaryouti, Mahmoud; Le Béon, Maryline; Moumani, Khaled; Thomas, Marion; Baize, Stephane

    2016-04-01

    also rupture together, or in a short period, during earthquake series. Combining our results with previous paleaoseismological studies in the region, we estimated lateral extent of earthquakes and we built regional rupture scenarios. The lateral extent of earthquake ruptures was also used to estimate the average co-seismic slip, using classical scaling laws, thus to assess the cumulated slip related to each rupture scenarios. Eventually, we tried to balance long-term tectonic loading with the computed cumulated slip to estimate the accumulated slip deficit for the Levant fault, from Aqaba to the south of Lebanon, over the documented period. The seismic-moment budget shows that levels of slip deficit, both north and south of the Dead Sea basin, are similarly high, which could suggest that a seismic crisis could happen over the entire region in a near future.

  11. Social Balance Theory

    OpenAIRE

    Hokky Situngkir; Deni Khanafiah

    2004-01-01

    We construct a model based on social balance theory proposed by Fritz Heider to analyze the interpersonal network among social agents. The model of social balance theory provides us an interesting tool to see how a social group evolves to the possible balance state. We introduce the balance index that can be used to measure social balance in macro structure level (global balance index) or in micro structure (local balance index) to see how the local balance index influences the global balance...

  12. Leaders as combat fighter pilots. Research project targets leaders who support money-losing business strategies.

    Science.gov (United States)

    Mitlyng, J W; Francis, D M; Wenzel, F J

    2001-01-01

    When strategic plans go awry and begin losing money, the smart thing to do is change course. But some leaders get so involved with the plan, they fail to navigate properly and fly right into the target. The organization can lose millions. Examine why this happens and what you can do to prevent it from happening in your organization.

  13. 25 CFR 115.808 - Could trust fund investments made by OTFM lose money?

    Science.gov (United States)

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false Could trust fund investments made by OTFM lose money? 115.808 Section 115.808 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR FINANCIAL ACTIVITIES... § 115.808 Could trust fund investments made by OTFM lose money? The value of trust fund investments...

  14. Prediction of fluid velocity slip at solid surfaces

    DEFF Research Database (Denmark)

    Hansen, Jesper Schmidt; Todd, Billy; Daivis, Peter

    2011-01-01

    methods, it allows us to directly compute the intrinsic wall-fluid friction coefficient rather than an empirical friction coefficient that includes all sources of friction for planar shear flow. The slip length predicted by our method is in excellent agreement with the slip length obtained from direct......The observed flow enhancement in highly confining geometries is believed to be caused by fluid velocity slip at the solid wall surface. Here we present a simple and highly accurate method to predict this slip using equilibrium molecular dynamics. Unlike previous equilibrium molecular dynamics...

  15. Inverting measurements of surface slip on the Superstition Hills fault

    Science.gov (United States)

    Boatwright, J.; Budding, K.E.; Sharp, R.V.

    1989-01-01

    We derive and test a set of inversions of surface-slip measurements based on the empirical relation u(t)=uf/(1 + T/t)c proposed by Sharp and Saxton (1989) to estimate the final slip uf, the power-law exponent c, and the power-law duration T. At short times, Sharp's relation behaves like the simple power law, u(t)~u1tc, where u1 is the initial slip, that is, the slip at 1 day after the earthquake. At long times, the slip approaches the final slip asymptotically. The inversions are designed in part to exploit the accuracy of measurements of differential slip; that is, measurements of surface slip which are made relative to a set of nails or stakes emplaced after the earthquake. We apply the inversions to slip measurements made at 53 sites along the Superstition Hills fault for the 11 months following the M=6.2 and 6.6 earthqakes of 24 November 1987. -from Authors

  16. On Slip Transmission Criteria in Experiments and Crystal Plasticity Models

    CERN Document Server

    Bayerschen, E; Reddy, B D; Böhlke, T

    2015-01-01

    A comprehensive overview is given on the slip transmission criteria for grain boundaries in the experimental literature, with a focus on slip system and grain boundary orientation. The use of these geometric criteria in continuum crystal plasticity models is briefly discussed. Perspectives on additional experimentally motivated criteria used in computational simulations are given. The theoretical framework of Gurtin (2008, J. Mech. Phys. Solids 56, p. 640) is reviewed for the single slip case with the aim of showing explicitly the connections to the experimentally developed criteria for slip transmission that are not discussed in the work itself.

  17. Slip and flow of hard-sphere colloidal glasses.

    Science.gov (United States)

    Ballesta, P; Besseling, R; Isa, L; Petekidis, G; Poon, W C K

    2008-12-19

    We study the flow of concentrated hard-sphere colloidal suspensions along smooth, nonstick walls using cone-plate rheometry and simultaneous confocal microscopy. In the glass regime, the global flow shows a transition from Herschel-Bulkley behavior at large shear rate to a characteristic Bingham slip response at small rates, absent for ergodic colloidal fluids. Imaging reveals both the "solid" microstructure during full slip and the local nature of the "slip to shear" transition. Both the local and global flow are described by a phenomenological model, and the associated Bingham slip parameters exhibit characteristic scaling with size and concentration of the hard spheres.

  18. Stochastic Wheel-Slip Compensation Based Robot Localization and Mapping

    Directory of Open Access Journals (Sweden)

    SIDHARTHAN, R. K.

    2016-05-01

    Full Text Available Wheel slip compensation is vital for building accurate and reliable dead reckoning based robot localization and mapping algorithms. This investigation presents stochastic slip compensation scheme for robot localization and mapping. Main idea of the slip compensation technique is to use wheel-slip data obtained from experiments to model the variations in slip velocity as Gaussian distributions. This leads to a family of models that are switched depending on the input command. To obtain the wheel-slip measurements, experiments are conducted on a wheeled mobile robot and the measurements thus obtained are used to build the Gaussian models. Then the localization and mapping algorithm is tested on an experimental terrain and a new metric called the map spread factor is used to evaluate the ability of the slip compensation technique. Our results clearly indicate that the proposed methodology improves the accuracy by 72.55% for rotation and 66.67% for translation motion as against an uncompensated mapping system. The proposed compensation technique eliminates the need for extro receptive sensors for slip compensation, complex feature extraction and association algorithms. As a result, we obtain a simple slip compensation scheme for localization and mapping.

  19. Fontan-associated protein-losing enteropathy and plastic bronchitis.

    Science.gov (United States)

    Schumacher, Kurt R; Stringer, Kathleen A; Donohue, Janet E; Yu, Sunkyung; Shaver, Ashley; Caruthers, Regine L; Zikmund-Fisher, Brian J; Fifer, Carlen; Goldberg, Caren; Russell, Mark W

    2015-04-01

    To characterize the medical history, disease progression, and treatment of current-era patients with the rare diseases Fontan-associated protein-losing enteropathy (PLE) and plastic bronchitis. A novel survey that queried demographics, medical details, and treatment information was piloted and placed online via a Facebook portal, allowing social media to power the study. Participation regardless of PLE or plastic bronchitis diagnosis was allowed. Case control analyses compared patients with PLE and plastic bronchitis with uncomplicated control patients receiving the Fontan procedure. The survey was completed by 671 subjects, including 76 with PLE, 46 with plastic bronchitis, and 7 with both. Median PLE diagnosis was 2.5 years post-Fontan. Hospitalization for PLE occurred in 71% with 41% hospitalized ≥ 3 times. Therapy varied significantly. Patients with PLE more commonly had hypoplastic left ventricle (62% vs 44% control; OR 2.81, 95% CI 1.43-5.53), chylothorax (66% vs 41%; OR 2.96, CI 1.65-5.31), and cardiothoracic surgery in addition to staged palliation (17% vs 5%; OR 4.27, CI 1.63-11.20). Median plastic bronchitis diagnosis was 2 years post-Fontan. Hospitalization for plastic bronchitis occurred in 91% with 61% hospitalized ≥ 3 times. Therapy was very diverse. Patients with plastic bronchitis more commonly had chylothorax at any surgery (72% vs 51%; OR 2.47, CI 1.20-5.08) and seasonal allergies (52% vs 36%; OR 1.98, CI 1.01-3.89). Patient-specific factors are associated with diagnoses of PLE or plastic bronchitis. Treatment strategies are diverse without clear patterns. These results provide a foundation upon which to design future therapeutic studies and identify a clear need for forming consensus approaches to treatment. Copyright © 2015 Elsevier Inc. All rights reserved.

  20. Triathletes Lose Their Advantageous Pain Modulation under Acute Psychosocial Stress.

    Science.gov (United States)

    Geva, Nirit; Pruessner, Jens; Defrin, Ruth

    2017-02-01

    Triathletes, who constantly engage in intensely stressful sport, were recently found to exhibit greater pain tolerance and more efficient pain inhibition capabilities than nonathletes. However, pain inhibition correlated negatively with retrospective reports of mental stress during training and competition. The aim of the current study was to test pain inhibition capabilities of triathletes under acute, controlled psychological stress manipulation. Participants were 25 triathletes and ironman triathletes who underwent the measurement of pain threshold, pain intolerance, tonic suprathreshold pain, and conditioned pain modulation before and during exposure to the Montreal Imaging Stress Task (MIST). Perceived ratings of stress and anxiety, autonomic variables, and salivary cortisol levels were obtained as indices of stress. The MIST induced a significant stress reaction manifested in the subjective and objective indices. Overall, a significant reduction in pain threshold and in conditioned pain modulation efficacy was observed after the MIST, which reached the baseline levels observed previously in nonathletes. Paradoxically, the magnitude of this stress-induced hyperalgesia (SIH) correlated negatively with the magnitude of the stress response; low-stress responders exhibited greater SIH than high-stress responders. The results suggest that under acute psychological stress, triathletes not only react with SIH and a reduction in pain modulation but also lose their advantageous pain modulation over nonathletes. The stronger the stress response recorded, the weaker the SIH. It appears that triathletes are not resilient to stress, responding with an increase in the sensitivity to pain as well as a decrease in pain inhibition. The possible effects of athletes' baseline pain profile and stress reactivity on SIH are discussed.

  1. RISKS OF LOSING CONTROLLABILITY WHILE LIBERALIZING THE ELECTRIC POWER INDUSTRY

    Directory of Open Access Journals (Sweden)

    Yu. S. Petrusha

    2015-01-01

    Full Text Available The paper analyses controllability qua a reliability characteristic of the electric-power grid controlling system. The following notions are used: the object (environment susceptibility towards the control stimuli, the controlling system adequacy, environment of the secure functioning. The author points to the necessity of accounting for the limitations of technological and organizational character. While liberalizing the electric-power industry, the backbone control-principle “the industry functioning reliability” is being replaced with the principle of “profit-making” that requires complete restatement of the control philosophy.The conflict between commercial benefit gaining and the reliability assurance expenses leads to losing controllability in all the managerial links and to probable catastrophic consequences. The recapitulation of the Russian Federation power industry privatization substantiates concerns of the liberal ideas poor survivability in the ex-Soviet territories. The results of degradation of the secure-functioning environment demonstrate affinity of the mechanisms that triggered the Chernobyl NPP, Fukusima NPP, and Sayan-Shushenskya HPP disasters. Securing reliability of the strategic objects leaves the competence boundaries of the electricpower industry.The topical issue of Belorussian electric-power industry functioning and developing is the combination of technical re-equipment (developing the operational dispatch management and the control-system organizational modernizing in general with gradual and controllable transition to the market mechanisms of functioning. Herewith, preserving the state monopoly on regime provision for the operation of the electric-power system should not leave out the industry appeal for outside investment and is regulated by the optimal degree and intensity of the state participation in governing the electric-power supply industry. The distinction of privatization models and the stages

  2. Fluid pressures at the shoe-floor-contaminant interface during slips: effects of tread and implications on slip severity.

    Science.gov (United States)

    Beschorner, Kurt E; Albert, Devon L; Chambers, April J; Redfern, Mark S

    2014-01-22

    Previous research on slip and fall accidents has suggested that pressurized fluid between the shoe and floor is responsible for initiating slips yet this effect has not been verified experimentally. This study aimed to (1) measure hydrodynamic pressures during slipping for treaded and untreaded conditions; (2) determine the effects of fluid pressure on slip severity; and (3) quantify how fluid pressures vary with instantaneous resultant slipping speed, position on the shoe surface, and throughout the progression of the slip. Eighteen subjects walked on known dry and unexpected slippery floors, while wearing treaded and untreaded shoes. Fluid pressure sensors, embedded in the floor, recorded hydrodynamic pressures during slipping. The maximum fluid pressures (mean+/-standard deviation) were significantly higher for the untreaded conditions (124+/-75 kPa) than the treaded conditions (1.1+/-0.29 kPa). Maximum fluid pressures were positively correlated with peak slipping speed (r=0.87), suggesting that higher fluid pressures, which are associated with untreaded conditions, resulted in more severe slips. Instantaneous resultant slipping speed and position of sensor relative to the shoe sole and walking direction explained 41% of the fluid pressure variability. Fluid pressures were primarily observed for untreaded conditions. This study confirms that fluid pressures are relevant to slipping events, consistent with fluid dynamics theory (i.e. the Reynolds equation), and can be modified with shoe tread design. The results suggest that the occurrence and severity of unexpected slips can be reduced by designing shoes/floors that reduce underfoot fluid pressures. © 2013 Published by Elsevier Ltd.

  3. Frictional Behavior and Slip Localization in Simulated Faults of Halite at Sub-seismic to Seismic Slip Rates

    Science.gov (United States)

    Kim, J.; Ree, J.; Han, R.; Shimamoto, T.

    2007-12-01

    Halite exhibits deformation behavior ranging from brittle to plastic at room temperature and at low pressures, and has been used to simulate deformation processes of the brittle-ductile transition zone. However, previous experiments on halite were performed at very low slip rates (10-9-10-3 m/s), requiring friction data at seismic slip rates for a more complete assessment of the applicability of the experimental results to natural earthquakes. We conducted friction experiments on halite at slip rate of 0.02-1.3 m/s and normal stresses of 0.8- 10.0 MPa using a high-velocity rotary shear apparatus. A thin layer (0.6-1.0 mm thick) of halite gouge was inserted between precut rock cylinders jacketed with Teflon sleeve. We found that mechanical behavior and deformation processes of halite gouge are remarkably different depending on slip rate and that frictional melting and dislocation creep can occur simultaneously at seismic slip rates. At sub-seismic slip rates of 0.02 to 0.05 m/sec, peak friction (μp = 0.76-0.85) was followed by steady-state friction (μss = 0.35-0.37). Gouge layer consists of a thin slip localization zone at the halite gouge-rock contact and a thick low slip-rate zone. The low slip-rate zone shows evidence for cataclastic flow with angular fragments set in a fine matrix. In contrast, the slip localization zone consists of very fine gouge with some remnants of fragments. At seismic slip rates of 0.1 to 1.3 m/sec, μp (0.64-0.99) was followed by μss (0.36-0.03). μss decreases with increasing slip rate. The shear zone consists of a thin slip localization zone at the halite gouge-rock contact and a thick low slip-rate zone. The low slip-rate zone consists of polycrystalline halite ribbons highly elongated obliquely to shear zone boundary and the oblique foliation is dragged into the thin slip localization zone. Each ribbon is also defined as a lattice preferred orientation domain by electron back-scattered diffraction (EBSD) analysis. Individual

  4. Surface fault slip associated with the 2004 Parkfield, California, earthquake

    Science.gov (United States)

    Rymer, M.J.; Tinsley, J. C.; Treiman, J.A.; Arrowsmith, J.R.; Ciahan, K.B.; Rosinski, A.M.; Bryant, W.A.; Snyder, H.A.; Fuis, G.S.; Toke, N.A.; Bawden, G.W.

    2006-01-01

    Surface fracturing occurred along the San Andreas fault, the subparallel Southwest Fracture Zone, and six secondary faults in association with the 28 September 2004 (M 6.0) Parkfield earthquake. Fractures formed discontinuous breaks along a 32-km-long stretch of the San Andreas fault. Sense of slip was right lateral; only locally was there a minor (1-11 mm) vertical component of slip. Right-lateral slip in the first few weeks after the event, early in its afterslip period, ranged from 1 to 44 mm. Our observations in the weeks following the earthquake indicated that the highest slip values are in the Middle Mountain area, northwest of the mainshock epicenter (creepmeter measurements indicate a similar distribution of slip). Surface slip along the San Andreas fault developed soon after the mainshock; field checks in the area near Parkfield and about 5 km to the southeast indicated that surface slip developed more than 1 hr but generally less than 1 day after the event. Slip along the Southwest Fracture Zone developed coseismically and extended about 8 km. Sense of slip was right lateral; locally there was a minor to moderate (1-29 mm) vertical component of slip. Right-lateral slip ranged from 1 to 41 mm. Surface slip along secondary faults was right lateral; the right-lateral component of slip ranged from 3 to 5 mm. Surface slip in the 1966 and 2004 events occurred along both the San Andreas fault and the Southwest Fracture Zone. In 1966 the length of ground breakage along the San Andreas fault extended 5 km longer than that mapped in 2004. In contrast, the length of ground breakage along the Southwest Fracture Zone was the same in both events, yet the surface fractures were more continuous in 2004. Surface slip on secondary faults in 2004 indicated previously unmapped structural connections between the San Andreas fault and the Southwest Fracture Zone, further revealing aspects of the structural setting and fault interactions in the Parkfield area.

  5. Characteristics and evolution of strike-slip tectonics of the Liaohe Western Sag,Bohai Bay Basin

    Institute of Scientific and Technical Information of China (English)

    Tong Hengmao; Yu Fusheng; Geng Changbo

    2008-01-01

    Because of its rich oil and gas resources and the special tectonic location of the Liaohe Western Sag(the Tanlu Fault traverses the sag),Bohai Bay Basin,a detailed study of its strike-slip tectonics is significant in revealing the sag's tectonic evolution,its control on hydrocarbon accumulation,and the activity history of the northern section of the Tanlu Fault in the Cenozoic.Through systematic structure analysis of 3D seismic data of the Liaohe Western Sag,combined with balanced section analysis,a variety of structural features in relation to right-lateral strike-slip faults,such as echelon normal faults, "comb"structure," flower"structure, "interpretable" and "buried" strike-slip faults have been revealed exist in the Liaohe Western Sag.According to the research in this paper,the complex structural phenomena in the Liaohe Western Sag could be reasonably interpreted as right-lateral strike-slip activity and the strikeo-slip activities of the Liaohe Western Sag began in the early Oligocene.The activity was weak at the beginning(E3S1-2),then strengthened gradually and reached its strongest level in the late Oligocene(E3dl).In the Miocene,the strike-slip activity was low and then strengthened significantly once again from the Pliocene to the present.It is speculated that the entire northern section of the Tanlu Fault has had a similar evolution history since the Oligocene.

  6. Dynamic Dislocation Mechanisms For the Anomalous Slip in a Single-Crystal BCC Metal Oriented for "Single Slip"

    Energy Technology Data Exchange (ETDEWEB)

    Hsiung, L; La Cruz, C

    2007-01-11

    Dislocation substructures of high-purity Mo single crystals deformed under uniaxial compression at room temperature to an axial strain of 0.6% were investigated in order to elucidate the underlying mechanisms for the {l_brace}0{bar 1}1{r_brace} anomalous slip in bcc metals [1], which is also known as the violation of Schmid law [2]. The test sample was oriented with the stress axis parallel to a nominal ''single-slip'' orientation of [{bar 2} 9 20], in which ({bar 1}01) [111] is the primary slip system that has a maximum Schmid factor (m = 0.5), which requires the lowest stress to operate among the twelve {l_brace}{bar 1}10{r_brace} <111> slip systems. Nevertheless, the recorded stress-strain curve reveals no easy-glide or single-slip stage; work hardening starts immediately after yielding. Moreover, the result of slip trace analysis indicates the occurrence of anomalous slip on both the (011) and (0{bar 1}1) planes, which according to the Schmid law requires relatively higher stresses to operate. TEM examinations of dislocation structures formed on the (101) primary slip plane reveal that in addition to the ({bar 1}01) [111] slip system, the coplanar ({bar 1}01) [1{bar 1}1] slip system which has a much smaller Schmid factor (m = 0.167) is also operative. Similarly, (0{bar 1}1) [111] (m = 0.25) is cooperative with the coplanar (0{bar 1}1) [{bar 1}11] slip system (m = 0.287) on the (0{bar 1}1) slip plane, and (011) [1{bar 1}1] (m = 0.222) is cooperative with the coplanar (011) [11{bar 1}] slip system (m = 0.32) on the (011) plane. The occurrence of {l_brace}0{bar 1}1{r_brace} anomalous slip is accordingly proposed to be originated from the cooperative dislocation motion of the {+-} 1/2 [111] and {+-} 1/2 [1{bar 1}1] dislocations on the ({bar 1}01) slip plane; the mutual interaction and blocking of {+-} 1/2 [111] and {+-} 1/2 [1{bar 1}1] dislocations not only cause an increase of glide resistance to the dislocation motion on the ({bar 1}01) plane

  7. Theoretical Proposals of Quantum Phase-slip Devices

    NARCIS (Netherlands)

    Hriscu, A.M.

    2012-01-01

    This thesis describes a series of theoretical proposals of novel circuits that embed ultrathin superconducting nanowires with coherent quantum phase-slips (QPS). The motivation for our proposals is twofold: firstly, to facilitate unambiguous experimental verification of coherent phase-slips. Secondl

  8. Friction and stick-slip in a telescope construction

    NARCIS (Netherlands)

    Hammerschlag, R.H.

    1986-01-01

    Stick-slip in high resolution telescopes should be avoided. The contact places where stick-slip can occur are described. Some contact places require a high friction coefficient, others a low friction coefficient. Some experiments have been carried out to find lubricants for contact places which comb

  9. Slipping and rolling on an inclined plane

    Energy Technology Data Exchange (ETDEWEB)

    Aghamohammadi, Cina [Department of Electrical Engineering, Sharif University of Technology, PO Box 11365-11155, Tehran (Iran, Islamic Republic of); Aghamohammadi, Amir, E-mail: mohamadi@alzahra.ac.ir [Department of Physics, Alzahra University, Tehran 19938-91176 (Iran, Islamic Republic of)

    2011-07-15

    In the first part of the paper, using a direct calculation two-dimensional motion of a particle sliding on an inclined plane is investigated for general values of friction coefficient ({mu}). A parametric equation for the trajectory of the particle is also obtained. In the second part of the paper, the motion of a sphere on the inclined plane is studied. It is shown that the evolution equation for the contact point of a sliding sphere is similar to that of a point particle sliding on an inclined plane whose friction coefficient is 7/2 {mu}. If {mu} > 2/7 tan {theta}, for any arbitrary initial velocity and angular velocity, the sphere will roll on the inclined plane after some finite time. In other cases, it will slip on the inclined plane. In the case of rolling, the centre of the sphere moves on a parabola. Finally the velocity and angular velocity of the sphere are exactly computed.

  10. Slip Effects in Compressible Turbulent Channel Flow

    CERN Document Server

    Skovorodko, P A

    2012-01-01

    The direct numerical simulation of compressible fully developed turbulent Couette flow between two parallel plates with equal temperatures moving in opposite directions with some velocity was performed. The algorithm was tested on well known numerical solution for incompressible Poiseuille channel flow and found to provide its well description. The slip effects in studied flow are found to be negligibly small at the values of accommodation coefficients for velocity and temperature of the order of unity. The considerable increase of mean temperature with decreasing the accommodation coefficient for temperature was discovered. The effect may be important in the problems of heat exchange in compressible turbulent boundary layer for some combinations of flowing gas, surface and adsorbing gas.

  11. Slip effects in compressible turbulent channel flow

    Science.gov (United States)

    Skovorodko, P. A.

    2012-11-01

    The direct numerical simulation of compressible fully developed turbulent Couette flow between two parallel plates with temperature Tw moving with velocities ±Uw was performed. The algorithm was tested on well known numerical solution for incompressible Poiseuille channel flow and found to provide its well description. The slip effects in studied flow are found to be negligibly small at the values of accommodation coefficients αu and αT of the order of unity. The considerable increase of mean temperature with decreasing the accommodation coefficient αT for fixed value of αu = 1 was discovered. The effect may be important in the problems of heat exchange in compressible turbulent boundary layer for some combinations of flowing gas, surface and adsorbing gas.

  12. Slipping and Rolling on an Inclined Plane

    CERN Document Server

    Aghamohammadi, Cina; 10.1088/0143-0807/32/4/017

    2011-01-01

    In the first part of the article using a direct calculation two-dimensional motion of a particle sliding on an inclined plane is investigated for general values of friction coefficient ($\\mu$). A parametric equation for the trajectory of the particle is also obtained. In the second part of the article the motion of a sphere on the inclined plane is studied. It is shown that the evolution equation for the contact point of a sliding sphere is similar to that of a point particle sliding on an inclined plane whose friction coefficient is $2/7}\\ \\mu$. If $\\mu> 2/7 \\tan\\theta$, for any arbitrary initial velocity and angular velocity the sphere will roll on the inclined plane after some finite time. In other cases, it will slip on the inclined plane. In the case of rolling center of the sphere moves on a parabola. Finally the velocity and angular velocity of the sphere are exactly computed.

  13. Slipped capital femoral epiphysis in down syndrome.

    Science.gov (United States)

    Dietz, Frederick R; Albanese, Stephen A; Katz, Danielle A; Dobbs, Matthew B; Salamon, Peter B; Schoenecker, Perry L; Sussman, Michael D

    2004-01-01

    Slipped capital femoral epiphysis (SCFE) and Down syndrome are both uncommon in the population at large, and rarely are both conditions present in a single individual. Institutional records were searched for both Down syndrome and SCFE. At least 2 years of follow-up was required. Eight patients were identified. At presentation four patients could not walk due to pain and four could walk. Six of eight hips presented with grade III SCFE. Four hips were treated with internal fixation in situ and four were manipulatively reduced in the operating room at the time of fixation with percutaneous screws or pins. Three hips healed uneventfully. Five hips developed aseptic necrosis (three partial, two whole head). This small retrospective study suggests an extremely high rate of complications in adolescents with Down syndrome and SCFE.

  14. Slipped upper femoral epiphysis with hemophilia A

    Directory of Open Access Journals (Sweden)

    Iyer Deepa

    2007-01-01

    Full Text Available A 13-year-old boy who had hemophilia A was reported with pain in the left thigh and hip on walking. He had no history of trauma. Severe hemophilia A is diagnosed with a Factor VIII level of < 1 iu/dl. The presumptive diagnosis was that of a spontaneous bleed into the hip joint. Factor VIII mutational analysis revealed a C to G substitution at nucleotide 6683 which results in a cystine change at codon 2194. However, the symptoms persisted and an X-ray demonstrated the presence of an acute on chronic slip of the upper femoral epiphysis. The patient was transferred to the center treating his hemophilia where the hip was pinned in situ under cover with Factor VIII. This case demonstrates the need to be aware of a possible traumatic diagnosis of hip pain in a hemophiliac child with a longstanding history of spontaneous bleeding into joints.

  15. Quantifying effective slip length over micropatterned hydrophobic surfaces

    CERN Document Server

    Tsai, Peichun; Pirat, Christophe; Wessling, Matthias; Lammertink, Rob G H; Lohse, Detlef

    2009-01-01

    We employ micro-particle image velocimetry ($\\mu$-PIV) to investigate laminar micro-flows in hydrophobic microstructured channels, in particular the slip length. These microchannels consist of longitudinal micro-grooves, which can trap air and prompt a shear-free boundary condition and thus slippage enhancement. Our measurements reveal an increase of the slip length when the width of the micro-grooves is enlarged. The result of the slip length is smaller than the analytical prediction by Philip et al. [1] for an infinitely large and textured channel comprised of alternating shear-free and no-slip boundary conditions. The smaller slip length (as compared to the prediction) can be attributed to the confinement of the microchannel and the bending of the meniscus (liquid-gas interface). Our experimental studies suggest that the curvature of the meniscus plays an important role in microflows over hydrophobic micro-ridges.

  16. The experimentalanalysis of the slip in the rubber belt CVT

    Science.gov (United States)

    Grzegożek, W.; Kot, A.

    2016-09-01

    This work deals with the analysis of the speed losses in CVT. The bench tests have been conducted on the scooter CVT equipped with the centrifugal regulation system. This solution is typical for this type of vehicles so the conducted experiments refer to real exploitation conditions. The slip has been defined on the base of the difference between speed ratios obtained from the angular speeds and the belt pitch radii. This approach corresponds with the Dittrich model. The non-linear dependence between the slip and the transmitted torque has been obtained for the constant gear ratio. Also non-linear dependence between the slip and the gear ratio has been received for constant torque. The amount of slip value indicates that this is significant part of the total power losses as it has been described by Bertini. However it clashes with the Chen researches, where the slip corresponds with the marginal part of the overall losses.

  17. The Slip Hypothesis: Tactile Perception and its Neuronal Bases.

    Science.gov (United States)

    Schwarz, Cornelius

    2016-07-01

    The slip hypothesis of epicritic tactile perception interprets actively moving sensor and touched objects as a frictional system, known to lead to jerky relative movements called 'slips'. These slips depend on object geometry, forces, material properties, and environmental factors, and, thus, have the power to incorporate coding of the perceptual target, as well as perceptual strategies (sensor movement). Tactile information as transferred by slips will be encoded discontinuously in space and time, because slips sometimes engage only parts of the touching surfaces and appear as discrete and rare events in time. This discontinuity may have forced tactile systems of vibrissae and fingertips to evolve special ways to convert touch signals to a tactile percept.

  18. Proposed Cavity for Reduced Slip-Stacking Loss

    Energy Technology Data Exchange (ETDEWEB)

    Eldred, J. [Indiana U.; Zwaska, R. [Fermilab

    2015-06-01

    This paper employs a novel dynamical mechanism to improve the performance of slip-stacking. Slip-stacking in an accumulation technique used at Fermilab since 2004 which nearly double the proton intensity. During slip-stacking, the Recycler or the Main Injector stores two particles beams that spatially overlap but have different momenta. The two particle beams are longitudinally focused by two 53 MHz 100 kV RF cavities with a small frequency difference between them. We propose an additional 106 MHz 20 kV RF cavity, with a frequency at the double the average of the upper and lower main RF frequencies. In simulation, we find the proposed RF cavity significantly enhances the stable bucket area and reduces slip-stacking losses under reasonable injection scenarios. We quantify and map the stability of the parameter space for any accelerator implementing slip-stacking with the addition of a harmonic RF cavity.

  19. Effect of slip on circulation inside a droplet

    CERN Document Server

    Thalakkottor, Joseph J

    2013-01-01

    Internal recirculation in a moving droplet plays an important role in several droplet-based microfluidic devices as it enhances mixing, chemical reaction and heat transfer. The occurrence of fluid slip at the wall, which becomes prominent at high shear rates and lower length scales, results in a significant change in droplet circulation. Using molecular dynamics (MD) simulations, the presence of circulation in droplets is demonstrated and quantified. Circulation is shown to vary inversely with slip length, which is a measure of interface wettability. A simple circulation model is established that captures the effect of slip on droplet circulation. Scaling parameters for circulation and slip length are identified from the circulation model which leads to the collapse of data for droplets with varying aspect ratio (AR) and slip length. The model is validated using continuum and MD simulations and is shown to be accurate for droplets with high AR.

  20. Thermal slip for liquids at rough solid surfaces

    Science.gov (United States)

    Zhang, Chengbin; Chen, Yongping; Peterson, G. P.

    2014-06-01

    Molecular dynamics simulation is used to examine the thermal slip of liquids at rough solid surfaces as characterized by fractal Cantor structures. The temperature profiles, potential energy distributions, thermal slip, and interfacial thermal resistance are investigated and evaluated for a variety of surface topographies. In addition, the effects of liquid-solid interaction, surface stiffness, and boundary condition on thermal slip length are presented. Our results indicate that the presence of roughness expands the low potential energy regions in adjacent liquids, enhances the energy transfer at liquid-solid interface, and decreases the thermal slip. Interestingly, the thermal slip length and thermal resistance for liquids in contact with solid surfaces depends not only on the statistical roughness height, but also on the fractal dimension (i.e., topographical spectrum).

  1. Numerical Investigations of Slip Phenomena in Centrifugal Compressor Impellers

    Science.gov (United States)

    Huang, Jeng-Min; Luo, Kai-Wei; Chen, Ching-Fu; Chiang, Chung-Ping; Wu, Teng-Yuan; Chen, Chun-Han

    2013-03-01

    This study systematically investigates the slip phenomena in the centrifugal air compressor impellers by CFD. Eight impeller blades for different specific speeds, wrap angles and exit blade angles are designed by compressor design software to analyze their flow fields. Except for the above three variables, flow rate and number of blades are the other two. Results show that the deviation angle decreases as the flow rate increases. The specific speed is not an important parameter regarding deviation angle or slip factor for general centrifugal compressor impellers. The slip onset position is closely related to the position of the peak value in the blade loading factor distribution. When no recirculation flow is present at the shroud, the variations of slip factor under various flow rates are mainly determined by difference between maximum blade angle and exit blade angle, Δβmax-2. The solidity should be of little importance to slip factor correlations in centrifugal compressor impellers.

  2. Stick-slip substructure in rapid tape peeling

    KAUST Repository

    Thoroddsen, Sigurdur T.

    2010-10-15

    The peeling of adhesive tape is known to proceed with a stick-slip mechanism and produces a characteristic ripping sound. The peeling also produces light and when peeled in a vacuum, even X-rays have been observed, whose emissions are correlated with the slip events. Here we present direct imaging of the detachment zone when Scotch tape is peeled off at high speed from a solid surface, revealing a highly regular substructure, during the slip phase. The typical 4-mm-long slip region has a regular substructure of transverse 220 μm wide slip bands, which fracture sideways at speeds over 300 m/s. The fracture tip emits waves into the detached section of the tape at ∼100 m/s, which promotes the sound, so characteristic of this phenomenon.

  3. Kinetic Energy Corrections for Slip-Stick Behavior in Brittle Adhesives

    Science.gov (United States)

    Macon, David J.; Anderson, Greg L.; McCool, Alex (Technical Monitor)

    2001-01-01

    Fracture mechanics is the study of the failure of a body that contains a flaw. In the energy balance approach to fracture mechanics, contributions from the external work and elastic strain energy are accounted for but rarely are corrections for the kinetic energy given. Under slip-stick conditions, part of the external work is expended as kinetic energy. The magnitude of this kinetic energy depends upon the shape of the crack. A specimen with a blunt crack will fail at a high load and the crack will catastrophically travel through the material until the kinetic energy is dissipated. Material with a sharp crack will fail at a lower load but will still be catastrophic in nature. A kinetic term is incorporated into the energy balance approach. This term accounts for the velocity of the crack after failure and how far the crack travels before arresting. This correction makes the shape of the initiation crack irrelevant. When applied to data generated by tapered double cantilever beam specimens under slip-stick conditions, the scatter in the measured critical strain energy release rate is significantly reduced.

  4. Polydimethylsiloxane SlipChip for mammalian cell culture applications.

    Science.gov (United States)

    Chang, Chia-Wen; Peng, Chien-Chung; Liao, Wei-Hao; Tung, Yi-Chung

    2015-11-07

    This paper reports a polydimethylsiloxane (PDMS) SlipChip for in vitro cell culture applications, multiple-treatment assays, cell co-cultures, and cytokine detection assays. The PDMS SlipChip is composed of two PDMS layers with microfluidic channels on each surface that are separated by a thin silicone fluid (Si-fluid) layer. The integration of Si-fluid enables the two PDMS layers to be slid to different positions; therefore, the channel patterns can be re-arranged for various applications. The SlipChip design significantly reduces the complexity of sample handling, transportation, and treatment processes. To apply the developed SlipChip for cell culture applications, human lung adenocarcinoma epithelial cells (A549) and lung fibroblasts (MRC-5) were cultured to examine the biocompatibility of the developed PDMS SlipChip. Moreover, embryonic pluripotent stem cells (ES-D3) were also cultured in the device to evaluate the retention of their stemness in the device. The experimental results show that cell morphology, viability and proliferation are not affected when the cells are cultured in the SlipChip, indicating that the device is highly compatible with mammalian cell culture. In addition, the stemness of the ES-D3 cells was highly retained after they were cultured in the device, suggesting the feasibility of using the SlipChip for stem cell research. Various cell experiments, such as simultaneous triple staining of cells and co-culture of MRC-5 with A549 cells, were also performed to demonstrate the functionalities of the PDMS SlipChip. Furthermore, we used a cytokine detection assay to evaluate the effect of endotoxin (lipopolysaccharides, LPS) treatment on the cytokine secretion of A549 cells using the SlipChip. The developed PDMS SlipChip provides a straightforward and effective platform for various on-chip in vitro cell cultures and consequent analysis, which is promising for a number of cell biology studies and biomedical applications.

  5. Preslip and cascade processes initiating laboratory stick slip

    Science.gov (United States)

    McLaskey, Gregory C.; Lockner, David A.

    2014-08-01

    Recent modeling studies have explored whether earthquakes begin with a large aseismic nucleation process or initiate dynamically from the rapid growth of a smaller instability in a "cascade-up" process. To explore such a case in the laboratory, we study the initiation of dynamic rupture (stick slip) of a smooth saw-cut fault in a 76 mm diameter cylindrical granite laboratory sample at 40-120 MPa confining pressure. We use a high dynamic range recording system to directly compare the seismic waves radiated during the stick-slip event to those radiated from tiny (M -6) discrete seismic events, commonly known as acoustic emissions (AEs), that occur in the seconds prior to each large stick slip. The seismic moments, focal mechanisms, locations, and timing of the AEs all contribute to our understanding of their mechanics and provide us with information about the stick-slip nucleation process. In a sequence of 10 stick slips, the first few microseconds of the signals recorded from stick-slip instabilities are nearly indistinguishable from those of premonitory AEs. In this sense, it appears that each stick slip begins as an AE event that rapidly (~20 µs) grows about 2 orders of magnitude in linear dimension and ruptures the entire 150 mm length of the simulated fault. We also measure accelerating fault slip in the final seconds before stick slip. We estimate that this slip is at least 98% aseismic and that it both weakens the fault and produces AEs that will eventually cascade-up to initiate the larger dynamic rupture.

  6. Dynamics and mass balance of Taylor Glacier, Antarctica: 3. State of mass balance

    Science.gov (United States)

    Kavanaugh, J. L.; Cuffey, K. M.; Morse, D. L.; Bliss, A. K.; Aciego, S. M.

    2009-11-01

    Taylor Glacier flows from the East Antarctic Ice Sheet and terminates in the McMurdo Dry Valleys, where it has left a geomorphologic record of past incursions. Here we use new data on the flow, thickness, and surface balance of Taylor Glacier to calculate ice fluxes and assess the current state of mass balance. Overall, the glacier is close to a state of zero net balance, and has largely adjusted to reduced snowfall on the Taylor Dome source region in the mid Holocene. One region of the upper ablation zone appears to be losing mass. Evidence from ice surface morphology and stable isotope profiles suggests that this mass loss is a long-term phenomenon, hence probably a lingering response to the earlier drying of Taylor Dome. Our data give a general indication of the size of ablation or accumulation changes needed for ice to advance far into Taylor Valley, as occurred 70 to 130 ka ago.

  7. Constitutive relations between dynamic physical parameters near a tip of the propagating slip zone during stick-slip shear failure

    Science.gov (United States)

    Ohnaka, Mitiyasu; Kuwahara, Yasuto; Yamamoto, Kiyohiko

    1987-12-01

    Constitutive relations between physical parameters in the cohesive zone during stick-slip shear failure are experimentally investigated. Stick-slip was generated along a 40 cm long precut fault in Tsukuba granite samples using a servocontrolled biaxial loading apparatus. Dynamic behavior during local breakdown processes near a tip of the slipping zone is revealed; the slip velocity and acceleration are given as a function of the slip displacement and the cohesive (or breakdown) shear stress as a function of the slip velocity. A cycle of the breakdown and restrengthening process of stick-slip is composed of five phases characterized in terms of the cohesive strength and the slip velocity. The cohesive strength can degrade regardless of the slip velocity during slip instabilities. The maximum slip acceleration ümax and the maximum slip velocity u˙max are obtained experimentally as: ümax= {2}/{u cu˙max2}andu˙max= {Δτ b}/{G}v where u c is the critical displacement, Δτb the breakdown stress drop, G the rigidity and v the rupture velocity. These relations are consistent with Ida's theoretical estimation based on the cohesive zone model. The above formula gives good estimates for the maximum slip acceleration of actual earthquakes. The cutoff frequency ƒ maxof the power spectral density of the slip acceleration increases with increasing normal stress; in particular, ƒ maxis found to be directly proportional to the normal stress σn within the normal stress range less than 17 MPa as: ƒ max(kHz) = 4.0σ n(MPa) σn<17(MPa) ƒ maxincrease with an increase in u˙max or ümax. All these results lead to the conclusion that ümax, u˙max and ƒ max increase with increasing normal stress. This is consistent with a previous observation that τb increases with increasing normal stress. The above empirical linear relation between ƒ max and σn can be explained by a linear dependence of Δτb on σn. The size-scale dependence of physical parameters is discussed, and such

  8. Loading and texture bias on the competitive slip activity for basal and prismatic slip systems in HCP alloys

    Science.gov (United States)

    Saxena, A. K.; Tewari, A.; Pant, P.

    2015-04-01

    Asymmetry in hexagonal crystal structure makes the occurrence of slip strongly dependent on the texture of sample. In titanium, which has a c/a ratio less than ideal, slip occurs preferentially on prismatic slip system. However other slip systems may get activated depending on the resolved shear stresses. In this paper we present results from plane strain compression experiments where the same area of the sample was imaged before and after deformation to document changes in microstructure. We then compare these results with a simple calculation of plastic strain based on activation of various slip systems depending on their respective critical resolved shear stresses. We show that incorporation of a strain rate dependent hardening parameter provides a reasonable match with the experimentally observed deformation behaviour of various grain orientations.

  9. Observations of premonitory acoustic emission and slip nucleation during a stick slip experiment in smooth faulted Westerly granite

    Science.gov (United States)

    Thompson, B.D.; Young, R.P.; Lockner, D.A.

    2005-01-01

    To investigate laboratory earthquakes, stick-slip events were induced on a saw-cut Westerly granite sample by triaxial loading at 150 MPa confining pressure. Acoustic emissions (AE) were monitored using an innovative continuous waveform recorder. The first motion of each stick slip was recorded as a large-amplitude AE signal. These events source locate onto the saw-cut fault plane, implying that they represent the nucleation sites of the dynamic failure stick-slip events. The precise location of nucleation varied between events and was probably controlled by heterogeneity of stress or surface conditions on the fault. The initial nucleation diameter of each dynamic instability was inferred to be less than 3 mm. A small number of AE were recorded prior to each macro slip event. For the second and third slip events, premonitory AE source mechanisms mimic the large scale fault plane geometry. Copyright 2005 by the American Geophysical Union.

  10. 'Obesity Gene' Doesn't Affect Ability to Lose Weight: Report

    Science.gov (United States)

    ... page: https://medlineplus.gov/news/fullstory_161090.html 'Obesity Gene' Doesn't Affect Ability to Lose Weight: ... 21, 2016 (HealthDay News) -- Having the so-called "obesity gene" doesn't affect people's ability to shed ...

  11. loses M. Kirigia“, Luis G. Sambo', W. Aldis' and Gerrnano M. Mwabuz

    African Journals Online (AJOL)

    The Burden of Natural and Technological Disaster—related Mortality on. Gross Domestic Product (GDP) in the WHO Africa Region loses M. Kirigia“, Luis G. Sambo', ..... health, reduces likelihood of smoking. [l8], increases the likelihood of toilet.

  12. Protein-Losing Enteropathy as a Complication of the Ketogenic Diet.

    Science.gov (United States)

    Ahn, Won Kee; Park, Soyoung; Kim, Heung Dong

    2017-07-01

    The ketogenic diet is an effective treatment for the patients with intractable epilepsy, however, the diet therapy can sometimes be discontinued by complications. Protein-losing enteropathy is a rarely reported serious complication of the ketogenic diet. We present a 16-month-old Down syndrome baby with protein-losing enteropathy during the ketogenic diet as a treatment for West syndrome. He suffered from diarrhea, general edema and hypoalbuminemia which were not controlled by conservative care for over 1 month. Esophagogastroduodenoscopy and stool alpha-1 antitrypsin indicated protein-losing enteropathy. Related symptoms were relieved after cessation of the ketogenic diet. Unexplained hypoalbuminemia combined with edema and diarrhea during ketogenic suggests the possibility of protein-losing enteropathy, and proper evaluation is recommended in order to expeditiously detect it and to act accordingly. © Copyright: Yonsei University College of Medicine 2017.

  13. Balancing cost and precision in hospital accountability sampling.

    Science.gov (United States)

    Perla, Rocco J; Allen, Bradford D

    2011-01-01

    The purpose of this article is to examine the relationship between sample size and cost using a benefit to cost ratio in the context of hospital accountability measures. We argue that the decision to use larger samples should include an assessment of the marginal benefit in terms of the cost to obtain the samples. Our main conclusion is that without recognizing and balancing the cost of different sampling schemes and developing reasonable cost limits we lose an opportunity at efficiency.

  14. Slip-behavior transitions of a heterogeneous linear fault

    Science.gov (United States)

    Yabe, S.; Ide, S.

    2016-12-01

    Shear-slip behavior on the fault has diversity, such as ordinary earthquakes, afterslips, and shallow and deep slow earthquakes. Although the cause of this diversity is a hot topic in seismology, one possibility is the friction varying with tectonic environments (e.g., Blanpied et al., 1991). It is often explained that negative, neutral, and positive a-b of rate and state friction law corresponds to seismogenic zone, slow earthquake, and creeps in subduction zones, respectively. However, the frictional heterogeneity is expected to exist on the fault because of the fractal irregular fault surface in a wide scale range (Candela et al., 2012), which fluctuate rupture propagations. To understand the slip behavior of such heterogeneous fault, we have conducted the simplest numerical simulations with an infinite linear fault embedded in the 2D elastic medium, on which frictional parameters have cyclic bimodal distributions. As a result, we have observed several types of slip behavior changing with the density of velocity weakening zone (VWZ) on the fault. At low densities with VWZ smaller than the nucleation size (Rubin and Ampuero, 2005), the fault slips stably. At medium densities, where the spatial average of a-b is positive, seismic slip occurs in VWZ followed by an afterslip in velocity-strengthening zone (VSZ). At high densities where the spatial average of a-b is negative, the entire fault including VSZ slips seismically. When the spatial average of a-b is close to zero, the transitional behavior is observed, in which seismic slip in VWZ and fast aseismic slip in VSZ are strongly interacted, and relatively slower deformation dominates. We also provide some examples with more complex distributions of frictional parameter to explore the possibility that the frictional heterogeneity may explain not only the diverse seismic phenomena, but also the scaling of slip weakening distance of ordinary earthquakes.

  15. EDITORIAL: Advanced fractions? or use it or lose it

    Science.gov (United States)

    Dobson, Ken

    1997-09-01

    kind of mixture of skill, knowledge and understanding required for successful mathematical operations is use it or lose it. We went `decimal' a long time ago, and the ideas of pence as 12ths of a shilling and shillings as 20ths of a pound are positively mediaeval for everyone under 40 or so. Remember farthings? In those days fractions were everywhere. Nowadays they are somewhat esoteric for the average citizen - and physicist. Yet fractions are vital in advanced mathematics, e.g. involving the differentiation and integration of polynomial fractions, as Peter Gill pointed out. This is why he was teaching simple fractions to his students, and possibly why their competence at these was such a good indicator of success in their end-of-year mathematics exam. What can we conclude from all this? I suggest two things. First, that fractions as illustrated above might well be considered as advanced mathematics, a fit and intriguing topic for an A-level course. Ordinary citizens should be taught - very thoroughly - to understand and use that useful kind of fraction based on dividing things into 100 parts, called percentages. Secondly, and more fundamentally, we should learn from this example to take a hard look at what we teach and what we need to teach, removing or adapting those things that exist in syllabuses and the National Curriculum for reasons of purely historical inertia. I hope that the IoP Working Party on Mathematics and Physics, due to report in the autumn, has looked hard at issues like this. And, of course, anyone interested in this topic is cordially invited to the Education Group's 16 - 19 Day Conference, which this year is about this vexed question of what mathematics physics learners need - and how they get it. At IoP Headquarters on Saturday, 15 November 1997. Details from Catherine Wilson.

  16. Simulation of the frictional stick-slip instability

    Science.gov (United States)

    Mora, Peter; Place, David

    1994-03-01

    A lattice solid model capable of simulating rock friction, fracture and the associated seismic wave radiation is developed in order to study the origin of the stick-slip instability that is responsible for earthquakes. The model consists of a lattice of interacting particles. In order to study the effect of surface roughness on the frictional behavior of elastic blocks being rubbed past one another, the simplest possible particle interactions were specified corresponding to radially dependent elastic-brittle bonds. The model material can therefore be considered as round elastic grains with negligible friction between their surfaces. Although breaking of the bonds can occur, fracturing energy is not considered. Stick-slip behavior is observed in a numerical experiment involving 2D blocks with rough surfaces being rubbed past one another at a constant rate. Slip is initiated when two interlocking asperities push past one another exciting a slip pulse. The pulse fronts propagate with speeds ranging from the Rayleigh wave speed up to a value between the shear and compressional wave speeds in agreement with field observations and theoretical analyses of mode-II rupture. Slip rates are comparable to seismic rates in the initial part of one slip pulse whose front propagates at the Rayleigh wave speed. However, the slip rate is an order of magnitude higher in the main part of pulses, possibly because of the simplified model description that neglected intrinsic friction and the high rates at which the blocks were driven, or alternatively, uncertainty in slip rates obtained through the inversion of seismograms. Particle trajectories during slip have motions normal to the fault, indicating that the fault surfaces jump apart during the passage of the slip pulse. Normal motion is expected as the asperities on the two surfaces ride over one another. The form of the particle trajectories is similar to those observed in stick-slip experiments involving foam rubber blocks ( Brune

  17. Detection of slip from multiple sites in an artificial finger

    Science.gov (United States)

    Muridan, N.; Chappell, P. H.; Cotton, D. P. J.; Cranny, A.; White, N. M.

    2009-07-01

    A Piezoelectric thick-film sensor is a good candidate for the extraction of information from object slip in hand prosthesis. Five slip sensors were fabricated on different linkages of an artificial hand. The signals from each sensor were compared to the output from the sensor mounted on the fingertip. An analysis of the output signals from all the sensors indicates that the linkage sensors also produce similar output signals to the fingertip sensor. In the next phase of the research, velocity and acceleration of the slipped object will be considered in the analysis.

  18. Pengurangan Hambatan Aliran pada Celah Silinder Koaksial Akibat Slip

    OpenAIRE

    Yanuar; Gunawan; M. Baqi

    2010-01-01

    Slip effect which occurs at the wall due to the layer of water repellent wall can reduce the pressure drop. The highly water repellent wall coating on the inside coaxial viscometer slip will be occur. The aim of experiment is proving drag reducing of the torque on the cylinder and the coefficient of velocity slip due to the water repellent coating on the wall. Teflon and wax materials are used to coat the surface of the wall. Contact angle of water droplets with a Teflon-coated walls and waxe...

  19. Simulation of engine auxiliary drive V-belt slip motion. Part 1. Development of belt slip model; Engine hoki V belt slip kyodo no simulation. 1. Belt slip model no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    Kurisu, T. [Mazda Motor Corp., Hiroshima (Japan)

    1997-10-01

    V-belts are widely used for driving auxiliary components of an engine. Inadequet design of such belt system sometimes results in troubles such as belt squeak, side rubber separation and/or bottom rubber crack. However, there has been no design tools which can predict belt slip quantitatively. The author developed a motion simulation program of Auxiliary Drive V-Belt System considering belt slip. The program showed good prediction accuracy for belt slip motion. This paper describes the simulation model. 1 ref., 12 figs.

  20. Efficient Numerical Modeling of Slow-Slip and Quasi-Dynamic Earthquake Ruptures

    Science.gov (United States)

    Bradley, A. M.; Segall, P.

    2010-12-01

    Motivated by the hypothesis that dilatancy plays a critical role in faulting in subduction zones, we are developing FDRA, a software package to simulate two-dimensional quasi-dynamic faulting that includes rate-state friction, thermal pressurization, dilatancy (following Segall and Rice [1995]), and flash heating [Rice, 2006]. FDRA accommodates full- and half-space models of faults having physical properties that vary in both the fault and fault-normal dimensions. Simulations reveal generic behavior over a broad range of property values: a typical earthquake cycle consists of a dynamic event (DE), a quiescent period, and then a long sequence of slow-slip events (SSE) preceding the next DE. The behavior for a model of a subduction zone bears many similarities to SSE in Cascadia, as described in Segall and Bradley [this meeting]. Partial differential equations in pressure and temperature are solved on profiles normal to the fault. The diffusion equations are discretized in space using finite differences on a nonuniform mesh having greater density near the fault. The full system of equations is a semiexplicit index-1 differential algebraic equation (DAE) in slip, state, fault zone porosity, pressure, and temperature. We integrate state, porosity, and slip explicitly; solve the stress-balance equation on the fault; and integrate pressure and temperature implicitly. For speed, we adaptively switch between this DAE time-integration technique and a pure-ODE approach; the latter is faster but less accurate. We use relative error control to calculate the time step adaptively over approximately twelve orders of magnitude. The nonlinear equations in pressure, temperature, and slip speed decouple by fault cell. Therefore, at each time stage, many relatively small nonlinear equations are solved rather than one large one. This decoupling is in itself faster and also provides opportunities for additional speedups. The primary work is solving linear systems associated with solving

  1. Scaling and jumping: gravity loses grip on small jumpers.

    Science.gov (United States)

    Scholz, Melanie N; Bobbert, Maarten F; Knoek van Soest, A J

    2006-06-21

    There are several ways to quantify jumping performance, a common definition being the height gained by the body's centre of mass (CM) in the airborne phase. Under this definition, jump height is determined by take-off velocity. According to the existing literature on jumping and scaling, take-off velocity, and hence jumping performance is independent of size because the energy that differently sized geometrically scaled jumpers can generate with their muscles is proportional to their mass. In this article it is shown, based on a simple energy balance, that it is incorrect to presume that jump height does not depend on size. Contrary to common belief, size as such has does have an effect on take-off velocity, putting small jumpers at a mechanical advantage, as is shown analytically. To quantify the effect of size on take-off velocity, a generic jumper model was scaled geometrically and evaluated numerically. While a 70-kg jumper took off at 2.65 m/s and raised its CM by 0.36 m after take-off, a perfectly geometrically similar jumper of 0.7 g reached a take-off velocity of 3.46 m/s and raised its CM by 0.61 m. The reason for the better performance of small jumpers is their higher efficacy in transforming the energy generated by the actuators into energy due to vertical velocity of the CM. Considering the ecological and evolutionary relevance of different definitions of jump height, size-dependent efficacy might explain why habitual jumping is especially prominent among small animals such as insects.

  2. Laboratory study of electromagnetic initiation of slip

    Directory of Open Access Journals (Sweden)

    V. Chikhladze

    2002-06-01

    Full Text Available Recently Russian seismologists reported the triggering effect of MHD soundings on microseismic activity in the Central Asia test area.The paper focuses on an experimental test of the possibility of triggering the mechanical instability of a system that is close to critical state by a series of electromagnetic pulses.The mechanical system consisted of two pieces of rock;the upper piece can slip on the fixed supporting sample if the latter one is tilted up to the critical angle.In this state,the triggering of mechanical instability by some weak impact such as electrical pulse became more probable.The slope of support in the experiment is an analogue of tectonic stress in natural conditions.The preliminary experiments,carried out in a dry environment,at the humidity of atmosphere 30-50%,show that a strong EM-pulse induces sliding of a sample of rock (granite,basalt,labradoriteplaced on the supporting sample which is inclined at the slope close to,but less than,the critical angle with a probability 0.07.

  3. Vertically bounded double diffusive convection in the fingering regime: comparing no-slip vs free-slip boundary conditions

    CERN Document Server

    Yang, Yantao; Lohse, Detlef

    2016-01-01

    Vertically bounded fingering double diffusive convection (DDC) is numerically investigated, focusing on the influences of different velocity boundary conditions, i.e. the no-slip condition which is inevitable in the lab-scale experimental research, and the free-slip condition which is an approximation for the interfaces in many natural environments, such as the oceans. For both boundary conditions the flow is dominated by fingers and the global responses follow the same scaling laws, with enhanced prefactors for the free-slip cases. Therefore, the laboratory experiments with the no-slip boundaries serve as a good model for the finger layers in the ocean. Moreover, in the free-slip case although the tangential shear stress is eliminated at the boundaries, the local dissipation rate in the near-wall region may exceed the value found in the no-slip cases, which is caused by the stronger vertical motions of fingers and sheet structures near the free-slip boundaries. This counter intuitive result might be relevant...

  4. Dizziness and Balance

    Science.gov (United States)

    AUDIOLOGY Dizziness and Balance Inform ation Seri es Our balance system helps us walk, run, and move without falling. ... if I have a problem with balance or dizziness? It is important to see your doctor if ...

  5. Slip distribution, strain accumulation and aseismic slip on the Chaman Fault system

    Science.gov (United States)

    Amelug, F.

    2015-12-01

    The Chaman fault system is a transcurrent fault system developed due to the oblique convergence of the India and Eurasia plates in the western boundary of the India plate. To evaluate the contemporary rates of strain accumulation along and across the Chaman Fault system, we use 2003-2011 Envisat SAR imagery and InSAR time-series methods to obtain a ground velocity field in radar line-of-sight (LOS) direction. We correct the InSAR data for different sources of systematic biases including the phase unwrapping errors, local oscillator drift, topographic residuals and stratified tropospheric delay and evaluate the uncertainty due to the residual delay using time-series of MODIS observations of precipitable water vapor. The InSAR velocity field and modeling demonstrates the distribution of deformation across the Chaman fault system. In the central Chaman fault system, the InSAR velocity shows clear strain localization on the Chaman and Ghazaband faults and modeling suggests a total slip rate of ~24 mm/yr distributed on the two faults with rates of 8 and 16 mm/yr, respectively corresponding to the 80% of the total ~3 cm/yr plate motion between India and Eurasia at these latitudes and consistent with the kinematic models which have predicted a slip rate of ~17-24 mm/yr for the Chaman Fault. In the northern Chaman fault system (north of 30.5N), ~6 mm/yr of the relative plate motion is accommodated across Chaman fault. North of 30.5 N where the topographic expression of the Ghazaband fault vanishes, its slip does not transfer to the Chaman fault but rather distributes among different faults in the Kirthar range and Sulaiman lobe. Observed surface creep on the southern Chaman fault between Nushki and north of City of Chaman, indicates that the fault is partially locked, consistent with the recorded MBalochistan and the populated areas such as the city of Quetta.

  6. The Slip History and Source Statistics of Major Slow Slip Events along the Cascadia Subduction Zone from 1998 to 2008

    Science.gov (United States)

    Gao, H.; Schmidt, D. A.

    2008-12-01

    We estimate the time dependent slip distribution of 16 prominent slow slip events along the northern half of the Cascadia subduction zone from 1998 to 2008. We process continuous GPS data from the PBO, PANGA and WCDA networks from the past decade using GAMIT/GLOBK processing package. Transient surface displacements are interpreted as slip on the plate interface using the Extended Network Inversion Filter. Of these 16 events, 10 events are centered north of Puget Sound, 4 events are resolved around the Columbia River and 1 event is located near Cape Blanco. The February 2003 event is complex, extending from Portland to southern Vancouver Island. Other smaller events beneath Northern Vancouver Island, Oregon and Northern California are not well resolved because of the limited station coverage. We identify two characteristic segments based on the along-strike extent of individual transient slip events in northern Washington. One segment is centered around Port Angeles. Another segment is between the Columbia River and the southern end of Puget Sound. The propagation direction of slow slip events is variable from one event to the next. The maximum cumulative slip for these 16 events is ~ 27 cm, which is centered beneath Port Angeles. This indicates that the strain release by transient slip is not uniform along-strike. In northwestern Washington where cumulative slip is a maximum, the subduction zone bends along-strike and dip of the plate is lower compared to the north and south. We hypothesize that the geometry of the slab plays an important role for focusing transient strain release at this location along the subduction zone. We explore the relationship of source parameters of slow slip using our catalogue of 16 events. The estimated moment magnitude ranges between 6.1 and 6.7. The average stress drop of 0.06-0.1 MPa is nearly two orders of magnitude smaller than that found for normal earthquakes (1-10 MPa). Standard earthquakes follow a scaling relationship where

  7. METHOD FOR DETECTING AND REPAIRING CYCLE SLIPS IN GPS NAVIGATION

    Institute of Scientific and Technical Information of China (English)

    CHAIYan-ju; OUJi-kun; RENChao

    2005-01-01

    A new method is proposed for detecting and repairing cycle slips in GPS navigation based on the dual frequency observations. It can be implemented through the following three steps: (1) The integer ambiguities of the current epoch are substituted by that of the previous epoch, so the ambiguity parameters are removed from the observation equations. (2) The abnormal observations are detected using the quasi accurate detection (QUAD) method and the satellite pairs of these abnormal observations are determined. Then the coefficient matrix of these satellite pairs is recovered. (3) The cycle slips of these satellite pairs are calculated using the LAMBDA method and integer ambiguities of the current epoch can be determined by adding the cycle slips into the integer ambiguities of the previous epoch. The key of this method is that the abnormal observations must accurately he detected, i.e. , the satellites having cycle slips must correctly be judged. Finally, compared with other methods the feasibility of the method is verified.

  8. Wheel slip dump valve for railway braking system

    Science.gov (United States)

    Zhang, Xuan; Zhang, LiHao; Li, QingXuan; Shi, YanTao

    2017-09-01

    As we all know, pneumatic braking system plays an important role in the safety of the whole vehicle. In the anti slip braking system, the pressure of braking cylinder can be adjusted by the quick power response of wheel slip dump valve, so that the lock situation won’t occur during vehicle service. During the braking of railway vehicles, the braking force provided by braking disc reduces vehicle’s speed. But the locking slip will happen due to the oversize of braking force or the reduction of sticking coefficient between wheel and rail. It will cause not only the decline of braking performance but also the increase of braking distance. In the meanwhile, it will scratch the wheel and influence the stable running of vehicles. Now, the speed of passenger vehicle has been increased. In order to shorten the braking distance as far as possible, sticking stickiness must be fully applied. So the occurrence probability of wheel slip is increased.

  9. Accurate speed and slip measurement of induction motors

    Energy Technology Data Exchange (ETDEWEB)

    Ho, S.Y.S.; Langman, R. [Tasmania Univ., Hobart, TAS (Australia)

    1996-03-01

    Two alternative hardware circuits, for the accurate measurement of low slip in cage induction motors, are discussed. Both circuits compare the periods of the fundamental of the supply frequency and pulses from a shaft-connected toothed-wheel. The better of the two achieves accuracy to 0.5 percent of slip over the range 0.1 to 0.005, or better than 0.001 percent of speed over the range. This method is considered useful for slip measurement of motors supplied by either constant frequency mains of variable speed controllers with PMW waveforms. It is demonstrated that accurate slip measurement supports the conclusions of work previously done on the detection of broken rotor bars. (author). 1 tab., 6 figs., 13 refs.

  10. Some sources for a slip in a translation by Freud.

    Science.gov (United States)

    Grossman, W I

    1988-01-01

    Among Freud's papers, we find instances in which Freud describes the "psychopathology of everyday life" as he found it in himself and in others. "A Religious Experience" (Freud, 1928) contains examples of both kinds. In addition, this paper contains a slip of which Freud appears to have been unaware. Freud's paper interprets a religious conversion described in a letter written to him in English. In the translation of this letter into German, Freud inserted material that was not present in the original. He mentions another slip he made in speaking about the letter. These slips and some associated details in the paper indicate persisting unconscious conflict. The content of these slips and details points to an association with Freud's childhood anxiety dream reported in The Interpretation of Dreams (Freud, 1900). Freud's associations and discussion of that dream lead to the Philippson Bible of his childhood, which provides additional connections to the paper of 1928.

  11. Analytical approximations for stick-slip vibration amplitudes

    DEFF Research Database (Denmark)

    Thomsen, Jon Juel; Fidlin, A.

    2003-01-01

    The classical "mass-on-moving-belt" model for describing friction-induced vibrations is considered, with a friction law describing friction forces that first decreases and then increases smoothly with relative interface speed. Approximate analytical expressions are derived for the conditions......, the amplitudes, and the base frequencies of friction-induced stick¿slip and pure-slip oscillations. For stick¿slip oscillations, this is accomplished by using perturbation analysis for the finite time interval of the stick phase, which is linked to the subsequent slip phase through conditions of continuity...... and periodicity. The results are illustrated and tested by time-series, phase plots and amplitude response diagrams, which compare very favorably with results obtained by numerical simulation of the equation of motion, as long as the difference in static and kinetic friction is not too large....

  12. Slip Updip of Tremor during the 2012 Cascadia ETS Event

    Science.gov (United States)

    Hall, K.; Houston, H.

    2014-12-01

    The interplay between tremor and slow slip during ETS has implications for the slip budget of the Cascadia subduction zone. In particular, it can constrain the downdip edge of the locked zone, which informs the hazard assessments for major cities including Seattle, Tacoma, and Vancouver. As shown by Houston (AGU abstract, 2012), slip inferred from GPS extended updip of the seismically-detected tremor in the 2010 M6.8 ETS event. Following the methods used on the 2010 ETS event, we used the PANGA GPS to measure the displacement vectors for 71 stations to analyze a large ETS event in 2012 that extended from Vancouver Island to Southern Washington. We implemented Principal Component Analysis to automatically select the direction and magnitude of the maximum displacement vector. We then inverted these GPS displacements for slip, using the Okada formulation of buried rectangular faults in a halfspace with a grid of 8 by 8 km subfaults based on the McCrory slab model. We performed inversions with either 0th or 2nd order Tikhonov regularization and found that over the 6 weeks of propagation, the 2012 ETS event released moment corresponding to M6.7, in three high-slip regions. We compared two different inversions, one where slip was allowed on a broad regional grid and a tremor-restricted inversion (TRI) where slip was restricted to grid locations where tremor had been detected in the 2012 ETS. We found that the TRI forced the slip to the updip edge of the grid where it reached above 10 cm, which is physically implausible given that this exceeds the slip that can accumulate in an inter-ETS time period. Additionally, the regional grid inversion indicates that 1 to 2 cm of slip occurred 10's of km updip of the western edge of tremor. This further supports the inference from the 2010 event that in northern Washington, the slow slip during an ETS event extends many kilometers updip of the western edge of tremor.

  13. Wheel rolling constraints and slip in mobile robots

    Energy Technology Data Exchange (ETDEWEB)

    Shekhar, S. [Oak Ridge National Lab., TN (United States). Robotics and Process Systems Div.

    1996-06-01

    It is widely accepted that dead-reckoning based on the rolling with no-slip condition on the wheels is not a reliable method to ascertain the position and orientation of a mobile robot for any reasonable distance. The authors establish that wheel slip is inevitable under the dynamic model of motion using classical results on the accessibility and controllability in nonlinear control theory and an analytical model of rolling of two linearly elastic bodies.

  14. Slipping Rib Syndrome as Persistent Abdominal and Chest Pain.

    Science.gov (United States)

    Bolaños-Vergaray, Juan Javier; de la Gala García, Francisco; Obaya Rebollar, Juan Carlos; Bové Alvarez, Maria

    2015-11-01

    Slipping rib syndrome is an overlooked cause of persistent abdominal or chest pain. The etiology of this syndrome is not well understood, but the characteristic pain is from hypermobility of the false ribs. Although it is a diagnosis of exclusion, misdiagnosis may lead to an excessive workup. A simple clinical examination via the hooking maneuver is the most significant feature of its diagnosis. We describe the case of a 41-year-old woman with slipping rib syndrome.

  15. The Crawford Slip Method: An Organizational Development Technique

    Science.gov (United States)

    1987-09-01

    This thesis is dedicated to the memory of Professor John Demidovich , whose interest and research inspired this study. - Debra Trent ii i ,I...According to Demidovich and Crawford (undated), the Crawford Slip Method is a system aimed at handling a large amount of inputs from a large number of...Ross Clayton, in an article by Crawford and Demidovich (1983a), states that few management techniques have the potential of the Crawford Slip Method as

  16. A non-slip boundary condition for lattice Boltzmann simulations

    CERN Document Server

    Inamuro, T; Ogino, F; Inamuro, Takaji; Yoshino, Masato; Ogino, Fumimaru

    1995-01-01

    A non-slip boundary condition at a wall for the lattice Boltzmann method is presented. In the present method unknown distribution functions at the wall are assumed to be an equilibrium distribution function with a counter slip velocity which is determined so that fluid velocity at the wall is equal to the wall velocity. Poiseuille flow and Couette flow are calculated with the nine-velocity model to demonstrate the accuracy of the present boundary condition.

  17. Foreshocks during the nucleation of stick-slip instability

    Science.gov (United States)

    McLaskey, Gregory C.; Kilgore, Brian D.

    2013-06-01

    report on laboratory experiments which investigate interactions between aseismic slip, stress changes, and seismicity on a critically stressed fault during the nucleation of stick-slip instability. We monitor quasi-static and dynamic changes in local shear stress and fault slip with arrays of gages deployed along a simulated strike-slip fault (2 m long and 0.4 m deep) in a saw cut sample of Sierra White granite. With 14 piezoelectric sensors, we simultaneously monitor seismic signals produced during the nucleation phase and subsequent dynamic rupture. We observe localized aseismic fault slip in an approximately meter-sized zone in the center of the fault, while the ends of the fault remain locked. Clusters of high-frequency foreshocks (Mw ~ -6.5 to -5.0) can occur in this slowly slipping zone 5-50 ms prior to the initiation of dynamic rupture; their occurrence appears to be dependent on the rate at which local shear stress is applied to the fault. The meter-sized nucleation zone is generally consistent with theoretical estimates, but source radii of the foreshocks (2 to 70 mm) are 1 to 2 orders of magnitude smaller than the theoretical minimum length scale over which earthquake nucleation can occur. We propose that frictional stability and the transition between seismic and aseismic slip are modulated by local stressing rate and that fault sections, which would typically slip aseismically, may radiate seismic waves if they are rapidly stressed. Fault behavior of this type may provide physical insight into the mechanics of foreshocks, tremor, repeating earthquake sequences, and a minimum earthquake source dimension.

  18. Slip Magnetohydrodynamic Viscous Flow over a Permeable Shrinking Sheet

    Institute of Scientific and Technical Information of China (English)

    FANG Tie-Gang; ZHANG Ji; YAO Shan-shan

    2010-01-01

    @@ The magnetohydrodynamic(MHD)flow under slip conditions over a shrinMng sheet js solved analytically.The solution is given in a closed form equation and is an exact solution of the full governing Navier-Stokes equations.Interesting solution behavior is observed with muiriple solution branches for certain parameter domain.The effects of the mass transfer,slip,andmagnetic parameters are discussed.

  19. Wheel rolling constraints and slip in mobile robots

    Energy Technology Data Exchange (ETDEWEB)

    Shekhar, S.

    1997-03-01

    It is widely accepted that dead reckoning based on the rolling with no slip condition on wheels is not a reliable method to ascertain the position and orientation of a mobile robot for any reasonable distance. We establish that wheel slip is inevitable under the dynamic model of motion using classical results on the accessibility and controllability in nonlinear control theory and an analytical model of rolling of two linearly elastic bodies.

  20. Wheel rolling constraints and slip in mobile robots

    Energy Technology Data Exchange (ETDEWEB)

    Shekhar, S.

    1997-03-01

    It is widely accepted that dead reckoning based on the rolling with no slip condition on wheels is not a reliable method to ascertain the position and orientation of a mobile robot for any reasonable distance. The author establishes that wheel slip is inevitable under the dynamic model of motion using classical results on the accessibility and controllability in nonlinear control theory and an analytical model of rolling of two linearly elastic bodies.

  1. Molecular Dynamics Simulations of Slip on Curved Surfaces

    Directory of Open Access Journals (Sweden)

    Ross D.A.

    2016-07-01

    Full Text Available We present Molecular Dynamics (MD simulations of liquid water confined within nanoscale geometries, including slit-like and cylindrical graphitic pores. These equilibrium results are used for calculating friction coefficients, which in turn can be used to calculate slip lengths. The slip length is a material property independent of the fluid flow rate. It is therefore a better quantity for study than the fluid velocity at the wall, also known as the slip velocity. Once the slip length has been found as a function of surface curvature, it can be used to parameterise Lattice Boltzmann (LB simulations. These larger scale simulations are able to tell us about how fluid transport is affected by slip in complex geometries; not just limited to single pores. Applications include flow and transport in nano-porous engine valve deposits and gas shales. The friction coefficient is found to be a function of curvature and is higher for fluid on convex surfaces and lower for concave surfaces. Both concave and convex surfaces approach the same value of the friction coefficient, which is constant above some critical radius of curvature, here found to be 7.4 ± 2.9 nm. The constant value of the friction coefficient is 10,000 ± 600 kg m−2 s−1, which is equivalent to a slip length of approximately 67 ± 4 nm.

  2. Small sized slip-ring capsule endurance testing

    Science.gov (United States)

    Mondier, Jean-Bernard

    2005-07-01

    Slip-ring capsules are mechanical units used to carry electrical signals or power currents through a rotating joint. They are used either in solar array drive mechanisms (SADM) or in scientific instruments like radiometers. Analyses of the latest missions show that the slip-rings requirements are more and more demanding. For example, the number of in-orbit mechanical cycles keeps increasing. As a result, a signal slip-ring technology, which had been successfully tested for a given need, now has to improve its performances. It was therefore interesting to try to reach the slip-rings technical limits by testing them beyond the required performance of already known space missions. Slip-rings units are currently used in mechanisms such as SADM for the CNES Proteus and Myriade satellite family. They can be also found in the payload instruments of the Megha-Tropiques satellite project, namely Madras and Scarab. A selected hardware was tested at the mechanism endurance laboratory of the CNES, in Toulouse. The typical in-orbit rotation speed was increased in order to limit the test duration to 2 years. The main interest of this work was to provide a continuous slip-ring performance status and a large set of engineering data. The main test results are presented and discussed. The following lines also report a part of the hardware detailed inspection and the lessons learned.

  3. Efficient Numerical Modeling of 3D, Half-Space, Slow-Slip and Quasi-Dynamic Earthquake Ruptures

    Science.gov (United States)

    Bradley, A. M.; Segall, P.

    2011-12-01

    Motivated by the hypothesis that dilatancy plays a critical role in faulting in subduction zones, we are developing FDRA2 (Fault Dynamics with the Radiation-damping Approximation), a software package to simulate three-dimensional quasi-dynamic faulting that includes rate-state friction, thermal pressurization, and dilatancy (following Segall and Rice [1995]) in a finite-width shear zone. This work builds on the two-dimensional simulations performed by FDRA1 (Bradley and Segall [AGU 2010], Segall and Bradley [submitted]). These simulations show that at lower background effective normal stress (\\bar σ), slow slip events occur spontaneously, whereas at higher \\bar σ , slip is inertially limited. At intermediate \\bar σ , dynamic events are followed by quiescent periods and then long durations of repeating slow slip events. Models with depth-dependent properties produce sequences similar to those observed in Cascadia. Like FDRA1, FDRA2 solves partial differential equations in pressure and temperature on profiles normal to the fault. The diffusion equations are discretized in space using finite differences on a nonuniform mesh having greater density near the fault. The full system of equations is a semiexplicit index-1 differential algebraic equation (DAE) in slip, slip rate, state, fault zone porosity, pressure, and temperature. We integrate state, porosity, and slip explicitly; solve the momentum balance equation on the fault for slip rate; and integrate pressure and temperature implicitly. Adaptive time steps are limited by accuracy and the stability criterion governing explicit integration of hyperbolic, but not the more stringent one governing parabolic, PDE. To compute elasticity in a 3D half-space, FDRA2 compresses the large, dense matrix arising from the boundary element method using an H-matrix. The work to perform a matrix-vector product scales almost linearly, rather than quadratically, in the number of fault cells. A new technique to relate the error

  4. Numerical Treatments of Slipping/No-Slip Zones in Cold Rolling of Thin Sheets with Heavy Roll Deformation

    Directory of Open Access Journals (Sweden)

    Yukio Shigaki

    2015-04-01

    Full Text Available In the thin sheet cold rolling manufacturing process, a major issue is roll elastic deformation and its impact on roll load, torque and contact stresses. As in many systems implying mechanical contact under high loading, a central part is under “sticking friction” (no slip while both extremities do slip to accommodate the material acceleration of the rolled metal sheet. This is a crucial point for modeling of such rolling processes and the numerical treatment of contact and friction (“regularized” or not, of the transition between these zones, does have an impact on the results. Two ways to deal with it are compared (regularization of the stick/slip transition, direct imposition of a no-slip condition and recommendations are given.

  5. A Multicoefficient Slip-Corrected Reynolds Equation for Micro-Thin Film Gas Lubrication

    Directory of Open Access Journals (Sweden)

    Ng Eddie Yin-Kwee

    2005-01-01

    Full Text Available This work investigates and analyzes the performance of conventional slip models among various regimes of Knudsen number and developes a new multicoefficient slip-velocity model, by using Taguchi quality control techniques and numerical analysis. A modified Reynolds equation is also derived based on the new slip-flow model. The multicoefficient slip model and its slip-corrected Reynolds equation are suitable to a wide Knudsen range from slip to transition regime. In comparison with other conventional slip models, it is found that the current results have a better agreement with the solution obtained from the linearized Boltzmann equation and direct simulation of Monte Carlo method (DSMC.

  6. From "no big deal" to "losing oneself": different meanings of mastectomy.

    Science.gov (United States)

    Fallbjörk, Ulrika; Salander, Pär; Rasmussen, Birgit H

    2012-01-01

    Because of early detection and advanced treatment options, more women with breast cancer survive after mastectomy and thus have to face the choice of living with or without a reconstructed breast for many years to come. This article investigates these women's narratives about the impact of mastectomy on their lives, as well as their reflections on breast reconstruction. Fifteen women were strategically chosen from a previous population-based study on mastectomy. They were contacted for further exploration in thematic narrative-inspired interviews 4.5 years after mastectomy. Three types of storylines were identified. In the first storyline, the mastectomy was described as "no big deal"; losing a breast did not disturb the women's view of themselves as women, and breast reconstruction was not even worth consideration. In the second storyline, the women described the mastectomy as shattering their identity. Losing a breast implied losing oneself as a sexual being, a woman, and a person. The third storyline fell in between the other two; the sense of femininity was wounded, but not to the extent that they felt lost as women. Our findings suggest that the experience of mastectomy due to breast cancer is very much individual and contextual. Losing a breast may be of minor or major importance. Healthcare practitioners should be attentive to how the women themselves experience the personal meaning of losing a breast and guard against vague preconceptions based on the breast-sexuality-femininity discourse and its connection to what the patient needs.

  7. Balance in Assessment

    Science.gov (United States)

    White, Richard

    2007-01-01

    The review by Black and Wiliam of national systems makes clear the complexity of assessment, and identifies important issues. One of these is "balance": balance between local and central responsibilities, balance between the weights given to various purposes of schooling, balance between weights for various functions of assessment, and balance…

  8. Evolving sensitivity balances Boolean Networks.

    Directory of Open Access Journals (Sweden)

    Jamie X Luo

    Full Text Available We investigate the sensitivity of Boolean Networks (BNs to mutations. We are interested in Boolean Networks as a model of Gene Regulatory Networks (GRNs. We adopt Ribeiro and Kauffman's Ergodic Set and use it to study the long term dynamics of a BN. We define the sensitivity of a BN to be the mean change in its Ergodic Set structure under all possible loss of interaction mutations. In silico experiments were used to selectively evolve BNs for sensitivity to losing interactions. We find that maximum sensitivity was often achievable and resulted in the BNs becoming topologically balanced, i.e. they evolve towards network structures in which they have a similar number of inhibitory and excitatory interactions. In terms of the dynamics, the dominant sensitivity strategy that evolved was to build BNs with Ergodic Sets dominated by a single long limit cycle which is easily destabilised by mutations. We discuss the relevance of our findings in the context of Stem Cell Differentiation and propose a relationship between pluripotent stem cells and our evolved sensitive networks.

  9. Living with clipped wings-patients' experience of losing a leg

    DEFF Research Database (Denmark)

    Norlyk, Annelise; Martinsen, Bente; Kjaer-Petersen, Klaus

    2013-01-01

    This study explores the lived experience of losing a leg as described by the patients themselves post-discharge. Studies have documented that regardless of aetiology patients are faced with severe physical as well as psychosocial challenges post-amputation. However, only few studies explore in....... The essential meaning of losing a leg is a radical and existential upheaval, which restricts patients' lifestyle and irretrievably alters their lifeworld. Life after the operation is associated with despair, and a painful sense of loss, but also with the hope of regaining personal independence. The consequences...... of losing a leg gradually materialize as the patients realize how the loss of mobility limits their freedom. Patients experience the professional help as primarily directed towards physical care and rehabilitation. The findings show that the loss of a leg and, subsequently, the restricted mobility carry...

  10. Slipping of the foot on the floor when pulling a pallet truck.

    Science.gov (United States)

    Li, Kai Way; Chang, Chien-Chi; Chang, Wen-Ruey

    2008-11-01

    Workers pulling pallet trucks are likely to slip when pulling and stepping on a low-friction floor. This study investigated the slipping of male participants when pulling a pallet truck, walking backward, and stepping on either a dry, wet, or glycerol-contaminated vinyl surface. The weight of the load on the truck was either low (0 kg), medium (295 kg), or high (568 kg). A motion-tracking system was used to collect the three-dimensional coordinates of the markers on the shoes. It was found that subjects might slip either upon landing of the leading foot on the toe (slip I) or before taking off of the lagging foot on the heel (slip II). The results indicated that the slip distances for both types of slip were significantly affected by the load and surface conditions and their interactions. Micro-slips (slips between 0.1 and 3 cm) and midi-slips (slips between 3 and 10 cm) were more common in slip I than in slip II. On glycerol-contaminated surfaces, the probabilities of a slide, or a slip more than 10 cm, for both slips I and II were over 40%. The implications of the results were discussed.

  11. DIFFERENCES IN GAME STATISTICS BETWEEN WINNING AND LOSING RUGBY TEAMS IN THE SIX NATIONS TOURNAMENT

    Directory of Open Access Journals (Sweden)

    José M. Palao

    2009-12-01

    Full Text Available The objective of the present study was to analyze the differences in rugby game statistics between winning and losing teams. The data from 58 games of round robin play from the Six Nations tournament from the 2003-2006 seasons were analyzed. The groups of variables studied were: number of points scored, way in which the points were scored; way teams obtained the ball and how the team used it; and technical and tactical aspects of the game. A univariate (t-test and multivariate (discriminant analysis of data was done. Winning teams had average values that were significantly higher in points scored, conversions, successful drops, mauls won, line breaks, possessions kicked, tackles completed, and turnovers won. Losing teams had significantly higher averages for the variables scrums lost and line-outs lost. The results showed that: a in the phases of obtaining the ball and more specifically in scrummage and line-out, winning teams lose fewer balls than losing teams (winning teams have an efficacy of 90% in both actions; b the winning team tends to play more with their feet when they obtain the ball, to utilize the maul as a way of attacking, and to break the defensive line more often than the losing team does; and c On defence, winning teams recovered more balls and completed more tackles than losing teams, and the percentage of tackles completed by winning teams was 94%. The value presented could be used as a reference for practice and competition in peak performance teams

  12. Attempts to lose weight among overweight and non-overweight adolescents: a cross-national survey

    Directory of Open Access Journals (Sweden)

    Tynjälä Jorma

    2007-10-01

    Full Text Available Abstract Background Despite the global obesity epidemic, few studies have performed cross-national comparisons of adolescents' attempts to lose weight and weight control practices. This study aims to investigate matters mentioned above by weight status in Europe, Israel, and North America. Methods Nationally representative samples of adolescents from over 30 countries completed an anonymous, standardized questionnaire as part of the Health Behaviour in School-aged Children 2001/2002 survey. The prevalence and likelihood of attempts to lose weight were determined. The effect of weight status, self-perception of overweight, age and country of residence upon the likelihood of current attempts to lose weight were evaluated using multilevel multivariate logistic regression in separate analyses for boys and girls. The study also presented the prevalence of weight control practices of overweight and non-overweight adolescents who had controlled their weight in seven countries. Results In general, overweight and obese adolescents were more likely to be engaged in current attempts to lose weight and had tried to control their weight during the past 12 months more often than non-overweight adolescents. Besides weight status, self-perception of overweight and age were significant individual-level factors determining current attempts to lose weight. Country of residence was a significant second-level factor but no clear geographical pattern was found. Several gender-related differences existed. Conclusion The findings indicated that most overweight adolescents were motivated to reduce their weight. The importance of promoting a healthy body image for all adolescents was highlighted by the fact that self-perception of overweight was found to be the most important factor leading to attempts to lose weight.

  13. Hot, Fast Faults: Evidence for High-Temperature Slip on Exhumed Faults, and Insights into Seismic Slip Processes

    Science.gov (United States)

    Evans, J. P.; Ault, A. K.; Janecke, S. U.; Prante, M. R.

    2015-12-01

    Microstructural and geochemical techniques combined with prior observations of naturally occurring faults provide insights into slip rates and slip dimensions of seismicity. We review four indicators for high coseismic paleotemperatures in brittle to semi-brittle faults from a wide range of tectonic settings with mm to km of slip. Thin, high-gloss, Fe-rich slip surfaces indicate high-temperature slip occurred on mm- to m-scales. Elliptical and circular zones of concentric iridescence indicate localized sites of elevated temperature that may be caused by heating at asperity contacts. The surface iridescence is associated with changes in Fe oxidation states detected by X-Ray photoelectron spectroscopy. Minimum temperature increases of 300 °C above ambient are supported by geochemical arguments and up to 800 °C are supported by analogs to high-speed friction experiments in steels and ceramics firing in reduced conditions. The presence of clay-rich foliated fault-related rocks, and the presence of nm- to mm-thick clay coatings indicate that syn-kinematic endothermic reactions occur at a range of scales. We suggest these features reflect temperature increases of ≥100-200 °C for activation energy required to drive the clay alteration is sourced from seismic energy and Schleicher-van der Pluijm-type slip surfaces to record instantaneous slip. Dense, low porosity planar porcelainite zones mm- to cm-thick along fault surfaces are the result of sintering of quartz-clay-feldspar mixtures and indicate T≥1000 °C localized along the surfaces, the result of post-slip cooling. Highly indurated, ultrafine fault-related rocks often consists of comminuted grains, vein fragments, and neocrystallized grains that represent retrograde cooling or alteration after peak heating. These observations and those of other recent workers indicate that many naturally occurring exhumed faults record elevated temperatures. In many cases, careful observations can delineate fault slip

  14. Win-stay-lose-learn promotes cooperation in the prisoner's dilemma game with voluntary participation.

    Science.gov (United States)

    Chu, Chen; Liu, Jinzhuo; Shen, Chen; Jin, Jiahua; Shi, Lei

    2017-01-01

    Voluntary participation, demonstrated to be a simple yet effective mechanism to promote persistent cooperative behavior, has been extensively studied. It has also been verified that the aspiration-based win-stay-lose-learn strategy updating rule promotes the evolution of cooperation. Inspired by this well-known fact, we combine the Win-Stay-Lose-Learn updating rule with voluntary participation: Players maintain their strategies when they are satisfied, or players attempt to imitate the strategy of one randomly chosen neighbor. We find that this mechanism maintains persistent cooperative behavior, even further promotes the evolution of cooperation under certain conditions.

  15. Cytomegalovirus-induced transient protein-losing hypertrophic gastropathy in an immunocompetent adult.

    Science.gov (United States)

    Suter, W R; Neuweiler, J; Borovicka, J; Binek, J; Fantin, A C; Meyenberger, C

    2000-01-01

    Transient protein-losing hypertrophic gastropathy with similarity to Ménétrier's disease is described. Acute infection with cytomegalovirus (CMV) could be shown to play a causative role. Immunodeficiency was ruled out. The 34-year-old patient had complete resolution of the disease without antiviral treatment. To our knowledge the present report is the first case of CMV-associated protein-losing hypertrophic gastropathy in an immunocompetent adult. To date, a similar disorder has only been described in children. CMV infection should be considered in patients with acute and symptomatic protein loss of gastrointestinal origin. Copyright 2000 S. Karger AG, Basel

  16. Your money or your self-esteem: threatened egotism promotes costly entrapment in losing endeavors.

    Science.gov (United States)

    Zhang, Liqing; Baumeister, Roy F

    2006-07-01

    The present research explored egotism-maintaining favorable views of the self-as a motivation underlying entrapment in losing endeavors. Four studies suggested that threatened selfesteem would cause decision makers to invest and lose more money in a previously chosen course of action. Ego-threatened participants consistently lost more money than nonthreatened participants across diverse entrapping situations regardless of whether the outcome was ostensibly determined by luck (Experiments 1 and 4), ability (Experiment 2), or interpersonal competition (Experiment 3). Thus, pursuing favorable views of the self could be costly to decision makers' financial well-being and may produce self-defeating behaviors.

  17. The Impact of Losing in a Competition on the Willingness to Seek Further Challenges

    OpenAIRE

    Buser, Thomas

    2014-01-01

    How do people react to setbacks and successes? I introduce a new measure of challenge-seeking to determine the effect of winning and losing in a competition on the willingness to seek further challenges. Participants in a lab experiment compete in two-person tournaments and are then informed of their score and the outcome of the competition. Conditional on the score, winning or losing is random. Participants then have to decide on a performance target for a second round: the higher the target...

  18. Nonoperative treatment of slipped capital femoral epiphysis: a scientific study

    Directory of Open Access Journals (Sweden)

    Pinheiro Pedro

    2011-02-01

    Full Text Available Abstract Background Treatment of the Slipped Capital Femoral Epiphysis remains a cause of concern due to the fact that the true knowledge of the etiopathogeny is unknown, as well as one of its major complications: chondrolysis. The conservative treatment remains controversial; it has been overlooked in the studies and subjected to intense criticism. The purpose of this study is to investigate the results of treatment on the hip of patients displaying slipped capital femoral epiphysis, using the plaster cast immobilization method and its link to chondrolysis. Methods The research was performed based on the study of the following variables: symptomatology, and the degree of slipping. A hip spica cast and bilateral short/long leg casts in abduction, internal rotation with anti-rotational bars were used for immobilizing the patient's hip for twelve weeks. Statistical analysis was accomplished by Wilcoxon's marked position test and by the Fisher accuracy test at a 5% level. Results A satisfactory result was obtained in the acute group, 70.5%; 94%; in the chronic group (chronic + acute on chronic. Regarding the degree of the slipping, a satisfactory result was obtained in 90.5% of hips tested with a mild slip; in 76% with moderate slip and 73% in the severe slip. The statistical result revealed that a significant improvement was found for flexion (p = 0.0001, abduction (p = 0.0001, internal rotation (p = 0.0001 and external rotation (p = 0.02. Chondrolysis was present in 11.3% of the hips tested. One case of pseudoarthrosis with aseptic capital necrosis was presented. There was no significant variation between age and chondrolysis (p = 1.00.Significant variation between gender/non-white patients versus chondrolysis (p = 0.031 and (p = 0.037, respectively was verified. No causal association between plaster cast and chondrolysis was observed (p = 0.60. In regard to the symptomatology group and the slip degree versus chondrolysis, the p value was not

  19. Scaling analysis for the investigation of slip mechanisms in nanofluids

    Directory of Open Access Journals (Sweden)

    Savithiri S

    2011-01-01

    Full Text Available Abstract The primary objective of this study is to investigate the effect of slip mechanisms in nanofluids through scaling analysis. The role of nanoparticle slip mechanisms in both water- and ethylene glycol-based nanofluids is analyzed by considering shape, size, concentration, and temperature of the nanoparticles. From the scaling analysis, it is found that all of the slip mechanisms are dominant in particles of cylindrical shape as compared to that of spherical and sheet particles. The magnitudes of slip mechanisms are found to be higher for particles of size between 10 and 80 nm. The Brownian force is found to dominate in smaller particles below 10 nm and also at smaller volume fraction. However, the drag force is found to dominate in smaller particles below 10 nm and at higher volume fraction. The effect of thermophoresis and Magnus forces is found to increase with the particle size and concentration. In terms of time scales, the Brownian and gravity forces act considerably over a longer duration than the other forces. For copper-water-based nanofluid, the effective contribution of slip mechanisms leads to a heat transfer augmentation which is approximately 36% over that of the base fluid. The drag and gravity forces tend to reduce the Nusselt number of the nanofluid while the other forces tend to enhance it.

  20. Measurement of Quantum Phase-Slips in Josephson Junction Chains

    Science.gov (United States)

    Guichard, Wiebke

    2011-03-01

    Quantum phase-slip dynamics in Josephson junction chains could provide the basis for the realization of a new type of topologically protected qubit or for the implementation of a new current standard. I will present measurements of the effect of quantum phase-slips on the ground state of a Josephson junction chain. We can tune in situ the strength of the phase-slips. These phase-slips are the result of fluctuations induced by the finite charging energy of each junction in the chain. Our measurements demonstrate that a Josephson junction chain under phase bias constraint behaves in a collective way. I will also show evidence of coherent phase-slip interference, the so called Aharonov-Casher effect. This phenomenon is the dual of the well known Aharonov-Bohm interference. In collaboration with I.M. Pop, Institut Neel, C.N.R.S. and Universite Joseph Fourier, BP 166, 38042 Grenoble, France; I. Protopopov, L. D. Landau Institute for Theoretical Physics, Kosygin str. 2, Moscow 119334, Russia and Institut fuer Nanotechnologie, Karlsruher Institut fuer Technologie, 76021 Karlsruhe, Germany; and F. Lecocq, Z. Peng, B. Pannetier, O. Buisson, Institut Neel, C.N.R.S. and Universite Joseph Fourier. European STREP MIDAS, ANR QUANTJO.

  1. Scaling analysis for the investigation of slip mechanisms in nanofluids

    Science.gov (United States)

    Savithiri, S.; Pattamatta, Arvind; Das, Sarit K.

    2011-07-01

    The primary objective of this study is to investigate the effect of slip mechanisms in nanofluids through scaling analysis. The role of nanoparticle slip mechanisms in both water- and ethylene glycol-based nanofluids is analyzed by considering shape, size, concentration, and temperature of the nanoparticles. From the scaling analysis, it is found that all of the slip mechanisms are dominant in particles of cylindrical shape as compared to that of spherical and sheet particles. The magnitudes of slip mechanisms are found to be higher for particles of size between 10 and 80 nm. The Brownian force is found to dominate in smaller particles below 10 nm and also at smaller volume fraction. However, the drag force is found to dominate in smaller particles below 10 nm and at higher volume fraction. The effect of thermophoresis and Magnus forces is found to increase with the particle size and concentration. In terms of time scales, the Brownian and gravity forces act considerably over a longer duration than the other forces. For copper-water-based nanofluid, the effective contribution of slip mechanisms leads to a heat transfer augmentation which is approximately 36% over that of the base fluid. The drag and gravity forces tend to reduce the Nusselt number of the nanofluid while the other forces tend to enhance it.

  2. How Orogen-scale Exhumed Strike-slip Faults Initiate

    Science.gov (United States)

    Cao, S.; Neubauer, F.

    2015-12-01

    Orogen-scale strike-slip faults present one the most important geodynamic processes affecting the lithosphere-asthenosphere system. In specific subtypes, faulting is virtually initiated along hot-to-cool boundaries, e.g. at such of hot granite intrusions or metamorphic core complexes to cool country rocks. Such fault zones are often subparallel to mountain ranges and expose a wide variety of mylonitic, cataclastic and non-cohesive fault rocks, which were formed at different structural levels of the crust and are stacked within each other ("telescoping"). Exhumation of rocks is, therefore, a common feature of such strike-slip faults implying major transtensive and/or transpressive processes accompanying pure strike-slip motion. The hot-to-cool thermal structure across the fault zone significantly influences the physical fault rock properties. One major question is how and where a major strike-slip initiates and further development. Here, we propose a model in which major continental exhumed strike-slip faults potentially evolve along rheologically weak zones such as plutons or margins of metamorphic complexes. As an example, we propose a model for the Ailao Shan-Red River (ASRR) fault, SE Asia, which initiated along the edge of a plutonic belt and evolved in response to India-Asia collision with four tectonic phases.

  3. 6.5 Years of Slow Slip Events in Cascadia: A Catalogue of SSE Surface Expressions, Interface Slip Distributions, Event Magnitudes and Relationship to Tremor.

    Science.gov (United States)

    Dimitrova, L. L.; Wallace, L. M.; Haines, A. J.; Bartlow, N. M.

    2015-12-01

    Slow slip events (SSEs) in Cascadia occur at ~30-50 km depth, every 10-19 months, and typically involve slip of a few cm, producing surface displacements on the order of a few mm up to ~1cm. Are there smaller SSE signals that are currently not recognized geodetically? What is the spatial, temporal and size distribution of SSEs, and how are SSE related to tremor? We address these questions with a catalogue of all detectable SSEs spanning the last 6.5 years using a new methodology based on Vertical Derivatives of Horizontal Stress (VDoHS) rates obtained from cGPS times series. VDoHS rates, calculated by solving the force balance equations at the Earth's surface, represent the most inclusive and spatially compact surface expressions of subsurface deformation sources: VDoHS rate vectors are tightly localized above the sources and point in the direction of push or pull. We compare our results with those from the Network Inversion Filter (NIF) for selected events. We identify and characterize a spectrum of SSEs, including events with moment release at least two orders of magnitudes smaller than has been previously identified with GPS data. We catalogue events timing, interface slip distribution and moment release, and compare our results with existing tremor catalogues. VDoHS rates also reveal the boundaries between the locked and unlocked portions of the megathrust, and we can track how this varies throughout the SSE cycle. Above the locked interface, the pull of the subducted plate generates shear tractions in the overlying plate in the direction of subduction, while above the creeping section shear tractions are in the opposite direction, which is reflected in the VDoHS rates. We show that sections of the Cascadia megathrust unlock prior to some SSEs and lock thereafter, with the locked zone propagating downdip and eastward after the SSEs over weeks to months. The catalogue and movies of events will be available at http://www.ig.utexas.edu/people/staff/lada/SSEs.

  4. What causes an icy fault to slip? Investigating strike-slip failure conditions on Ganymede at Dardanus and Tiamat Sulcus.

    Science.gov (United States)

    Cameron, M. E.; Smith-Konter, B. R.; Burkhard, L. M.; Collins, G. C.; Seifert, F.; Pappalardo, R. T.

    2015-12-01

    Ganymede exhibits two geologically distinct terrains known as dark and light (grooved) terrain. The mechanism for a transition from dark to light terrain remains unclear; however, inferences of strike-slip faulting and distributed shear zones suggest that strike-slip tectonism may be important to the structural development of Ganymede's surface and in this transition. Here we investigate the role of tidal stresses on Ganymede in the formation and evolution of strike-slip structures in both dark and grooved terrains. Using numerical code SatStress, we calculate both diurnal and non-synchronous rotation (NSR) tidal stresses at Ganymede's surface. Specifically, we investigate the role of fault friction and orbital eccentricity in the development of ~45 km of right-lateral offset at Dardanus Sulcus and a possible case of Sulcus. We compute Coulomb failure conditions for these target fractures and consider tidal stress scenarios for both present eccentricity (0.0013) and possible past high (~0.05) eccentricity of Ganymede. We find that while diurnal stresses are not large enough to support strike-slip failure at present or past eccentricities, models that include both diurnal and NSR stress readily generate shear and normal stress magnitudes that could give rise to shear failure. Results for a past high eccentricity assuming a low coefficient of friction (μf = 0.2) suggest shear failure is possible down to depths of 1-2 km along both Dardanus and Tiamat. For a high coefficient of friction (μf = 0.6), failure is limited to about 1 km depth at Dardanus and Tiamat, although confined to small episodic slip windows for the latter. Moreover, our models predict a right-lateral sense of slip, in agreement with inferred offset observed at both regions. Based on these results, we infer that past shear failure on Ganymede is possible when NSR is a driving stress mechanism. We complement this study with a detailed morphological mapping of strike-slip morphologies (en echelon

  5. Atomistic Determination of Cross-Slip Pathway and Energetics

    DEFF Research Database (Denmark)

    Rasmussen, Torben; Jacobsen, Karsten Wedel; Leffers, Torben

    1997-01-01

    The mechanism for cross slip of a screw dislocation in Cu is determined by atomistic simulations that only presume the initial and final states of the process. The dissociated dislocation constricts in the primary plane and redissociates into the cross-slip plane while still partly in the primary...... plane. The transition state and activation energy for cross slip as well as the energies of the involved dislocation constrictions are determined. One constriction has a negative energy compared to parallel partials. The energy vs splitting width for recombination of parallel partials into a perfect...... dislocation is determined. The breakdown of linear elasticity theory for small splitting widths is studied. [S0031-9007(97)04444-X]....

  6. SLIP VELOCITY IN PULSED DISC AND DOUGHNUT EXTRACTION COLUMN

    Directory of Open Access Journals (Sweden)

    Mohammad Outokesh

    2011-09-01

    Full Text Available In the present work, slip velocity has been measured in a 76 mm diameter pulsed disc and doughnut extraction column for four different liquid-liquid systems. The effects of operating variables including pulsation intensity and dispersed and continuous phase flow rates on slip velocity have been investigated. The existence of three different operational regimes, namely mixersettler, transition, and emulsion regimes, was observed when the energy input was changed. Empirical correlations are derived for prediction of the slip velocity in terms of operating variables, physical properties of the liquid systems, and column geometry for different regimes. Good agreement between prediction and experiments was found for all operating conditions that were investigated.

  7. Preliminary soil-slip susceptibility maps, southwestern California

    Science.gov (United States)

    Morton, Douglas M.; Alvarez, Rachel M.; Campbell, Russell H.; Digital preparation by Bovard, Kelly R.; Brown, D.T.; Corriea, K.M.; Lesser, J.N.

    2003-01-01

    This group of maps shows relative susceptibility of hill slopes to the initiation sites of rainfall-triggered soil slip-debris flows in southwestern California. As such, the maps offer a partial answer to one part of the three parts necessary to predict the soil-slip/debris-flow process. A complete prediction of the process would include assessments of “where”, “when”, and “how big”. These maps empirically show part of the “where” of prediction (i.e., relative susceptibility to sites of initiation of the soil slips) but do not attempt to show the extent of run out of the resultant debris flows. Some information pertinent to “when” the process might begin is developed. “When” is determined mostly by dynamic factors such as rainfall rate and duration, for which local variations are not amenable to long-term prediction. “When” information is not provided on the maps but is described later in this narrative. The prediction of “how big” is addressed indirectly by restricting the maps to a single type of landslide process—soil slip-debris flows. The susceptibility maps were created through an iterative process from two kinds of information. First, locations of sites of past soil slips were obtained from inventory maps of past events. Aerial photographs, taken during six rainy seasons that produced abundant soil slips, were used as the basis for soil slip-debris flow inventory. Second, digital elevation models (DEM) of the areas that were inventoried were used to analyze the spatial characteristics of soil slip locations. These data were supplemented by observations made on the ground. Certain physical attributes of the locations of the soil-slip debris flows were found to be important and others were not. The most important attribute was the mapped bedrock formation at the site of initiation of the soil slip. However, because the soil slips occur in surficial materials overlying the bedrocks units, the bedrock formation can only serve as

  8. Quantum Nucleation of Phase Slips in 1-d Superfluids

    Science.gov (United States)

    Arovas, Daniel

    1998-03-01

    The rate for quantum nucleation of phase slips past an impurity in a one-dimensional superfluid is computed. Real time evolution of the nonlinear Schrödinger equation shows that there is a critical velocity vc below which solutions are time-independent [1,2]; this is the regime of quantum phase slip nucleation. We start with the Gross-Pitaevskii model in the presence of an impurity potential, and derive the Euclidean action for a space-time vortex-antivortex pair, which describes a phase slip event. The action is computed as a function of the superfluid velocity v and the impurity potential width and depth.l [1] V. Hakim, Phys. Rev. E 55, 2835 (1997).l [1] J. A. Freire, D. P. Arovas, and H. Levine, Phys. Rev. Lett (in press, 1997).l

  9. Offset of latest pleistocene shoreface reveals slip rate on the Hosgri strike-slip fault, offshore central California

    Science.gov (United States)

    Johnson, Samuel Y.; Hartwell, Stephen R.; Dartnell, Peter

    2014-01-01

    The Hosgri fault is the southern part of the regional Hosgri–San Gregorio dextral strike‐slip fault system, which extends primarily in the offshore for about 400 km in central California. Between Morro Bay and San Simeon, high‐resolution multibeam bathymetry reveals that the eastern strand of the Hosgri fault is crossed by an ∼265  m wide slope interpreted as the shoreface of a latest Pleistocene sand spit. This sand spit crossed an embayment and connected a western fault‐bounded bedrock peninsula and an eastern bedrock highland, a paleogeography resembling modern coastal geomorphology along the San Andreas fault. Detailed analysis of the relict shoreface with slope profiles and slope maps indicates a lateral slip rate of 2.6±0.9  mm/yr, considered a minimum rate for the Hosgri given the presence of an active western strand. This slip rate indicates that the Hosgri system takes up the largest share of the strike‐slip fault budget and is the most active strike‐slip fault west of the San Andreas fault in central California. This result further demonstrates the value and potential of high‐resolution bathymetry in characterization of active offshore faults.

  10. Evaluation of the "Lose Your Excuse" Public Service Advertising Campaign for Tweens to Save Energy

    Science.gov (United States)

    Bertrand, Jane T.; Goldman, Patty; Zhivan, Natalia; Agyeman, Yaw; Barber, Erin

    2011-01-01

    This study evaluates the 2008-2009 "Lose your Excuse" public service advertising (PSA) campaign on energy efficiency targeting 8- to 12-year-olds, intended to increase knowledge, foster proactive attitudes, and change energy usage behaviors. Baseline and two follow-up surveys were conducted with online samples representative of the national…

  11. Predicting losing and gaining river reaches in lowland New Zealand based on a statistical methodology

    Science.gov (United States)

    Yang, Jing; Zammit, Christian; Dudley, Bruce

    2017-04-01

    The phenomenon of losing and gaining in rivers normally takes place in lowland where often there are various, sometimes conflicting uses for water resources, e.g., agriculture, industry, recreation, and maintenance of ecosystem function. To better support water allocation decisions, it is crucial to understand the location and seasonal dynamics of these losses and gains. We present a statistical methodology to predict losing and gaining river reaches in New Zealand based on 1) information surveys with surface water and groundwater experts from regional government, 2) A collection of river/watershed characteristics, including climate, soil and hydrogeologic information, and 3) the random forests technique. The surveys on losing and gaining reaches were conducted face-to-face at 16 New Zealand regional government authorities, and climate, soil, river geometry, and hydrogeologic data from various sources were collected and compiled to represent river/watershed characteristics. The random forests technique was used to build up the statistical relationship between river reach status (gain and loss) and river/watershed characteristics, and then to predict for river reaches at Strahler order one without prior losing and gaining information. Results show that the model has a classification error of around 10% for "gain" and "loss". The results will assist further research, and water allocation decisions in lowland New Zealand.

  12. Living with clipped wings—Patients’ experience of losing a leg

    Directory of Open Access Journals (Sweden)

    Annelise Norlyk

    2013-10-01

    Full Text Available This study explores the lived experience of losing a leg as described by the patients themselves post-discharge. Studies have documented that regardless of aetiology patients are faced with severe physical as well as psychosocial challenges post-amputation. However, only few studies explore in-depth the patients’ perspective on the various challenges following the loss of a leg. The study uses the phenomenological approach of Reflective Lifeworld Research (RLR. Data were collected from 24 in-depth interviews with 12 Danish patients. Data analysis was performed according to the guidelines given in RLR. The essential meaning of losing a leg is a radical and existential upheaval, which restricts patients’ lifestyle and irretrievably alters their lifeworld. Life after the operation is associated with despair, and a painful sense of loss, but also with the hope of regaining personal independence. The consequences of losing a leg gradually materialize as the patients realize how the loss of mobility limits their freedom. Patients experience the professional help as primarily directed towards physical care and rehabilitation. The findings show that the loss of a leg and, subsequently, the restricted mobility carry with them an existential dimension which refers to limitation of action space and loss of freedom experienced as an exclusion from life. Our findings demonstrate a need for complementary care and stress the importance of an increased awareness of the psychosocial and existential consequences of losing a limb.

  13. 2007 Presidential Address: Fear of Losing Control--Power, Perfectionism, and the Psychology of Women

    Science.gov (United States)

    Chrisler, Joan C.

    2008-01-01

    Anecdotal evidence and popular culture suggest that fear of losing control of oneself is common among North American women, yet there is little in the way of data or theory to show why so many women fear loss of control or how to help them to leave that fear behind. In this article a commonly accepted definition of self-regulation is examined…

  14. 20 CFR 663.565 - May an eligible training provider lose its eligibility?

    Science.gov (United States)

    2010-04-01

    ... of title I of WIA or the WIA regulations, including 29 CFR part 37, may be removed from the list in... training to appeal a denial of eligibility under this subpart according to the requirements of 20 CFR 667... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false May an eligible training provider lose...

  15. A series of transient slip events on Kilauea volcano, Hawaii.

    Science.gov (United States)

    Desmarais, E. K.; Segall, P.; Miklius, A.; Cervelli, P.

    2005-12-01

    Deformation on Kilauea volcano, Hawaii is monitored by a network of continuously recording GPS stations, among other methds. Since its installation in 1996, the GPS network has detected four spatially coherent accelerations on Kilauea's south flank that are not caused by either intrusions or earthquakes. These events, each lasting several hours to two days, occurred in September 1998, November 2000, July 2003, and January 2005. Previously, Cervelli et al., (Nature, 2002) interpreted the 2000 event as a silent earthquake due to slip on a sub-horizontal fault beneath Kilauea's south flank. We inverted the cumulative displacements ( less than 2 cm) using a simulated annealing algorithm for each event and found similarly sized, near horizontal, uniform slip source locations for all four events at depths of ~6 km. The estimated slip magnitudes are between 9 and 15 cm, with the upper block moving seaward. The 2005 event is the largest detected to date. Volcano-tectonic (VT) earthquakes on the south flank of Kilauea are typically restricted to the volume between the East Rift Zone and the Hilina and Poliokeawe Palis. Seismicity in this volume increased significantly during the silent events at depths of 5-10 km. However, all of the VT earthquakes were small ( less than M3) and their cumulative moment does not account for the moment released during the silent slip events. We are currently examining seismic waveform data for evidence of other signals, such as non-volcanic tremor, that might be associated with the slip events. To determine the exact onset and duration of the silent earthquakes, we invert for slip as a function of time directly from raw GPS phase and pseudorange observations. The November 2000 silent earthquake was preceded 9 days earlier by nearly 1 m of rainfall, which was speculated in Cervelli et al., (Nature, 2002) to have reduced fault stability through surface loading or pore pressure increase. In contrast, both the 2003 and 2005 events occurred

  16. Volcano instability induced by strike-slip faulting

    Science.gov (United States)

    Lagmay, A. M. F.; van Wyk de Vries, B.; Kerle, N.; Pyle, D. M.

    2000-09-01

    Analogue sand cone experiments were conducted to study instability generated on volcanic cones by basal strike-slip movement. The results of the analogue models demonstrate that edifice instability may be generated when strike-slip faults underlying a volcano move as a result of tectonic adjustment. This instability occurs on flanks of the volcano above the strike-slip shear. On the surface of the volcano this appears as a pair of sigmoids composed of one reverse and one normal fault. In the interior of the cone the faults form a flower structure. Two destabilised regions are created on the cone flanks between the traces of the sigmoidal faults. Bulging, intense fracturing and landsliding characterise these unstable flanks. Additional analogue experiments conducted to model magmatic intrusion show that fractures and faults developed within the volcanic cone due to basal strike-slip motions strongly control the path of the intruding magma. Intrusion is diverted towards the areas where previous development of reverse and normal faults have occurred, thus causing further instability. We compare our model results to two examples of volcanoes on strike-slip faults: Iriga volcano (Philippines), which underwent non-magmatic collapse, and Mount St. Helens (USA), where a cryptodome was emplaced prior to failure. In the analogue and natural examples, the direction of collapse takes place roughly parallel to the orientation of the underlying shear. The model presented proposes one mechanism for strike-parallel breaching of volcanoes, recently recognised as a common failure direction of volcanoes found in regions with transcurrent and transtensional deformation. The recognition of the effect of basal shearing on volcano stability enables prediction of the likely direction of eventual flank failure in volcanoes overlying strike-slip faults.

  17. Phase-field slip-line theory of plasticity

    Science.gov (United States)

    Freddi, Francesco; Royer-Carfagni, Gianni

    2016-09-01

    A variational approach to determine the deformation of an ideally plastic substance is proposed by solving a sequence of energy minimization problems under proper conditions to account for the irreversible character of plasticity. The flow is driven by the local transformation of elastic strain energy into plastic work on slip surfaces, once that a certain energetic barrier for slip activation has been overcome. The distinction of the elastic strain energy into spherical and deviatoric parts is used to incorporate in the model the idea of von Mises plasticity and isochoric plastic strain. This is a "phase field model" because the matching condition at the slip interfaces is substituted by the evolution of an auxiliary phase field that, similar to a damage field, is unitary on the elastic phase and null on the yielded phase. The slip lines diffuse in bands, whose width depends upon a material length-scale parameter. Numerical experiments on representative problems in plane strain give solutions with noteworthy similarities with the results from classical slip-line field theory, but the proposed model is much richer because, accounting for elastic deformations, it can describe the formation of slip bands at the local level, which can nucleate, propagate, widen and diffuse by varying the boundary conditions. In particular, the solution for a long pipe under internal pressure is very different from the one obtainable from the classical macroscopic theory of plasticity. For this case, the location of the plastic bands may be an insight to explain the premature failures that are sometimes encountered during the manufacturing process. This practical example enhances the importance of this new theory based on the mathematical sciences.

  18. Possible Stick-Slip Mechanism for Whillans Ice Stream

    Science.gov (United States)

    Bindschadler, Robert; King, Matt; Vornberger, Patricia

    2003-01-01

    Tidally-induced stick-slip motion in the mouth of Whillans Ice Stream provides a unique natural experiment in ice-stream response behavior and from which we might learn a great deal about subglacial till properties and sub-ice-stream conditions. At the IGS Symposium on Fast Glacier Flow (Yakutat, 2002), we reported our observations of stick- slip motion and demonstrated its synchronicity with tidal forcing. Recently, we have completed additional processing of our GPS data in differential mode. It reveals more details of the stick-slip events and illustrates that within 30 seconds, the temporal interval of our data, the ice stream accelerates to a speed corresponding to a completely lubricated bed. While details of individual events vary, there seems to be strong evidence of an elastic rebound on the time scale of one hour following most events. This suggests the event involves the release of stored elastic strain energy in the ice. The similar displacements of events suggest further that till or subglacial hydrologic properties limit the amount of elastic strain released in any single event. We follow a line of reasoning that dilatant strengthening limits the slip displacement and present model of the stick-slip process. To match the observed delay between the peak ocean tide and stick-slip events, our model includes a propagating pressure wave in the subglacial hydrologic system between the grounding line, where the rising tide first increases the subglacial water pressure and regions upstream where stored elastic strain increases the basal shear stress. This high-tide event is released when the increased water pressure reaches the region of increased shear stress. Dilatant strengthening stops the event by increasing pore volume and lowering the water pressure. Following this event, falling tide increases the normal forces, compresses the till and increases pore pressure again, leading to the second falling-tide event we observe every tidal cycle.

  19. Global strike-slip faults: Bounds from plate tectonics

    Science.gov (United States)

    Gordon, R. G.; Argus, D. F.

    2006-12-01

    According to the tenets of plate tectonics, a transform fault is a strike-slip fault along which neither convergence nor divergence occurs. Analysis of global plate motion data indicates that the only true transform faults are the strike-slip faults that offset segments of mid-ocean ridges. Thus, many of Earth's major strike-slip fault systems are not true transform faults as they accommodate large components of oblique convergence or oblique divergence. This is particularly true for several important ocean-continent systems such as the San Andreas, the strike-slip systems bounding the northern and southern Caribbean plate, the Alpine fault system of New Zealand, the Anatolian fault system, and the Azores-Gibraltar-Alboran sea system. These strike-slip systems are commonly sites of large scale mountain building and basin formation. Here we examine the far-field constraints on the motions of the plates bounding several of these strike-slip systems using both conventional plate motion circuits and results from global positioning system and other space geodetic data. We pay particular attention to the San Andreas fault system in central and northern California, where the San Andreas system is part of the boundary between the Sierran microplate and the Pacific plate. Most of the fault system accommodates obliquely convergent motion, giving rise to the California Coast Range, but in the northern San Francisco Bay Area it is obliquely divergent, producing San Pablo Bay and a gap in the Coast Range that permits the Sierran watershed to drain to the Pacific through the Golden Gate.

  20. Back analysis of fault-slip in burst prone environment

    Science.gov (United States)

    Sainoki, Atsushi; Mitri, Hani S.

    2016-11-01

    In deep underground mines, stress re-distribution induced by mining activities could cause fault-slip. Seismic waves arising from fault-slip occasionally induce rock ejection when hitting the boundary of mine openings, and as a result, severe damage could be inflicted. In general, it is difficult to estimate fault-slip-induced ground motion in the vicinity of mine openings because of the complexity of the dynamic response of faults and the presence of geological structures. In this paper, a case study is conducted for a Canadian underground mine, herein called "Mine-A", which is known for its seismic activities. Using a microseismic database collected from the mine, a back analysis of fault-slip is carried out with mine-wide 3-dimensional numerical modeling. A back analysis is conducted to estimate the physical and mechanical properties of the causative fracture or shear zones. One large seismic event has been selected for the back analysis to detect a fault-slip related seismic event. In the back analysis, the shear zone properties are estimated with respect to moment magnitude of the seismic event and peak particle velocity (PPV) recorded by a strong ground motion sensor. The estimated properties are then validated through comparison with peak ground acceleration recorded by accelerometers. Lastly, ground motion in active mining areas is estimated by conducting dynamic analysis with the estimated values. The present study implies that it would be possible to estimate the magnitude of seismic events that might occur in the near future by applying the estimated properties to the numerical model. Although the case study is conducted for a specific mine, the developed methodology can be equally applied to other mines suffering from fault-slip related seismic events.

  1. Superplastic flow lubricates carbonate faults during earthquake slip

    Science.gov (United States)

    De Paola, Nicola; Holdsworth, Robert; Viti, Cecilia; Collettini, Cristiano; Faoro, Igor; Bullock, Rachael

    2014-05-01

    Tectonic earthquakes are hosted in the shallower portion of crustal fault zones, where fracturing and cataclasis are thought to be the dominant processes during frictional sliding. Aseismic shear in lower crust and lithospheric mantle shear zones is accomplished by crystal plasticity, including superplastic flow acting at low strain rates on ultrafine-grained rocks. Superplasticity has also been observed at high strain rates for a range of nano-phase alloys and ceramics, and could potentially occur in fine-grained geological materials, if deformed at high strain rates and temperatures. We performed a set of displacement-controlled experiments to explore whether superplastic flow can effectively weaken faults, and facilitate earthquake propagation. The experiments were performed on fine-grained synthetic gouges (63 lubrication mechanisms. When T ≥ 800 °C are attained, micro-textures diagnostic of diffusion-dominated grain boundary sliding are widespread within the slip zone, and suggest bulk superplastic flow. Flow stresses predicted by superplasticity constitutive laws at the slip zone temperatures, grain sizes and strain rates attained during the experiments match those we measured in the laboratory (μ = 0.16). We propose therefore that the activation of diffusion creep at high temperatures (T ≥ 800 °C) leads to slip zone-localised superplastic flow and that this causes the dynamic weakening of carbonate faults at seismic slip rates. Note, however, that both cataclasis and dislocation creep operating at lower temperatures, during the earlier stages of slip, are critical, precursory processes needed to produce the nanoscale grain sizes required to activate grainsize sensitive mechanisms during superplastic flow. Finally, the re-strengthening observed during the decelerating phase of deformation can be explained by the falling temperature "switching off" slip zone-localized superplasticity, leading to a return to frictional sliding. These results indicate

  2. Strength and Balance Exercises

    Science.gov (United States)

    ... Peripheral Artery Disease Venous Thromboembolism Aortic Aneurysm More Strength and Balance Exercises Updated:Sep 8,2016 If ... Be Safe While Being Active - Stretching & Flexibility Exercises - Strength & Balance Exercises - Problems & Solutions for Being Active - FAQs ...

  3. Balanced Scorecard voor inkoop

    NARCIS (Netherlands)

    Honing, van der R.; Schotanus, F.

    2003-01-01

    Een Balanced Scorecard kan ontwikkeld worden voor de hele organisatie, maar ook voor onderdelen daarvan. In dit artikel wordt ingegaan op de ontwikkeling van een Balanced Scorecard voor de inkoopafdeling

  4. A unified slip boundary condition for flow over a surface

    CERN Document Server

    Thalakkottor, Joseph John

    2015-01-01

    Interface between two phases of matter are ubiquitous in nature and technology. Determining the correct velocity condition at an interface is essential for understanding and designing of flows over a surface. We demonstrate that both the widely used no-slip and the Navier and Maxwell slip boundary conditions do not capture the complete physics associated with complex problems, such as spreading of liquids or corner flows. Hence, we present a unified boundary condition that is applicable to a wide-range of flow problems.

  5. Slip effects on shearing flows in a porous medium

    Institute of Scientific and Technical Information of China (English)

    M.Khan; T.Hayat; Y.Wang

    2008-01-01

    This paper deals with the magnetohydrodynamic (MHD)flow of an Oldroyd 8-constant fluid in a porous mediam when no-slip condition is no longer valid.Modified Darcy's law is used in the flow modelling.The non-linear differential equation with non-linear boundary conditions is solved numerically using finite difference scheme in combination with an iterative technique.Numerical results are obtained for the Conette,Poiseuille and generalized Couette flows.The effects of slip parameters on the velocity profile are discussed.

  6. Stokes Flow with Slip and Kuwabara Boundary Conditions

    Indian Academy of Sciences (India)

    Sunil Datta; Satya Deo

    2002-08-01

    The forces experienced by randomly and homogeneously distributed parallel circular cylinder or spheres in uniform viscous flow are investigated with slip boundary condition under Stokes approximation using particle-in-cell model technique and the result compared with the no-slip case. The corresponding problem of streaming flow past spheroidal particles departing but little in shape from a sphere is also investigated. The explicit expression for the stream function is obtained to the first order in the small parameter characterizing the deformation. As a particular case of this we considered an oblate spheroid and evaluate the drag on it.

  7. The seasonal dependence of cycle slip occurrence of GPS data over China low latitude region

    Institute of Scientific and Technical Information of China (English)

    ZHANG DongHe; FENG Man; XIAO Zuo; HAO YongQiang; SHI LiQin; YANG GuangLin; SUO YuCheng

    2007-01-01

    The relationship of daily accumulated cycle slip occurrence with the season is analyzed using the GPS data observed in six GPS stations located in China low latitude region in 2001. It is found that the seasonal dependence of cycle slip occurrence is evident. The cycle slip mainly occurs during the periods of two equinox months (March to May and September to October), and some correlative changes of the cycle slip occurrences over all six stations are exhibited in some special days. Considering the diurnal dependence of cycle slip, it can be inferred that the cycle slip occurrence with certain elevation limitation is related with the ionospheric irregularities over this region.

  8. Losing control

    DEFF Research Database (Denmark)

    Leppink, Eric; Odlaug, Brian Lawrence; Lust, Katherine

    2014-01-01

    with respondents without lifetime assaultive behavior, those with a history of assaultive or destructive behavior reported more depressive symptoms, more stress, and higher rates of a range of impulse control disorders (intermittent explosive disorder, compulsive sexual behavior, compulsive buying, and skin...

  9. Uniform Strike-Slip Rate along the Xianshuihe-Xiaojiang Fault System and Its Implications for Active Tectonics in Southeastern Tibet

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Recent studies on the Xianshuihe-Xiaojiang fault system suggest that the Late Quaternary strike-slip rate is approximately uniform along the entire length of the fault zone, about 15±2 mm/a.This approximately uniform strike slip rate strongly supports the clockwise rotation model of the southeastern Tibetan crust. By approximating the geometry of the arc-shaped Xianshuihe-Xiaojiang fault system as a portion of a small circle on a spherical Earth, the 15±2 mm/a strike slip rate corresponds to clockwise rotation of the Southeastern Tibetan Block at the (5.2±0.7)×10-7 deg/a angular velocity around the pole (21°N, 88°E) relative to the Northeast Tibetan Block. The approximately uniform strike slip rate along the Xianshuihe-Xiaojiang fault system also implies that the Longmenshan thrust zone is not active, or at least its activity has been very weak since the Late Quaternary. Moreover,the total offset along the Xianshuihe-Xiaojiang fault system suggests that the lateral extrusion of the Southeastern Tibetan Block relative to Northeastern Tibetan Block is about 160 km and 200-240 km relative to the Tarim-North China block. This amount of lateral extrusion of the Tibetan crust should have accommodated about 13-24% convergence between India and Eurasia based on mass balance calculations. Assuming that the slip rate of 15±2 mm/a is constant throughout the entire history of the Xianshuihe-Xiaojiang fault system, 11±1.5 Ma is needed for the Xianshuihe-Xiaojiang fault system to attain the 160 km of total offset. This implies that left-slip faulting on the Xianshuihe-Xiaojiang fault system might start at 11±1.5 Ma.

  10. Fault Slip Embedded in Creep: Insight into Tectonic Tremors and Slow Slip Events from Acoustic and Optical Monitoring of Fractures

    Science.gov (United States)

    Elkhoury, J. E.; Lengline, O.; Ampuero, J. P.; Schmittbuhl, J.

    2010-12-01

    Observations of temporal and spatial correlations between slow slip earthquakes and tectonic tremor activity suggest a physical relation between them. Early descriptions of mechanisms relating these phenomena simply attributed the relation between seismic and aseismic events to fluid mediated processes. More recent hypotheses suggest that tectonic tremors are bursts of seismic energy due to the rupturing of small asperities within slow slipping regions. Here we present laboratory results of a unique experimental setting aimed at understanding the response to transient loads of a system of small asperities embedded in creep as a model of tectonic tremor activity triggered by slow slip and modulated by tides. We performed mode I crack propagation experiments on glass bead blasted and annealed 2D interfaces of transparent material (Polymethylmethacrylate) where fracture fronts were confined to the 2D weakness plane of the heterogeneous interface. We monitored acoustic emissions (AE) with piezo-electric sensors surrounding the crack front line. We also optically monitored the rupture front line with up to 1000 frames per second. The experimental loading conditions produce quasi-static front propagation at slow average speeds. Image processing reveals de-pinning along the front that we characterize as intermittent opening during slow front propagation. AE locations strongly correlate to the spatiotemporal clustering of the de-penning events along the front. Moreover, this correlation is preserved at the time of imposed transient fluctuations in loading during front propagation. Using the analogy between mode I and modes II and III fractures, our results translate into intermittent slip on faults linked to clustering of seismic activity produced by the breakage of asperities embedded in creeping regions with no need of invoking fluid mediated processes. Thus our experiments help reveal the interplay between aseismic and seismic slip on faults. We also observe qualitative

  11. Offset of Latest Pleistocene Shoreface Reveals Slip Rate on the Hosgri Strike-Slip Fault, Offshore Central California

    Science.gov (United States)

    Johnson, S. Y.; Hartwell, S. R.; Dartnell, P.

    2014-12-01

    The Hosgri fault is the southern part of the regional Hosgri-San Gregorio dextral strike-slip fault system, which extends primarily in the offshore region for about 400 km in central California. Between Morro Bay and San Simeon, high-resolution multibeam bathymetry reveals that the eastern strand of the Hosgri fault is crossed by a ~265-m-wide slope interpreted as the shoreface of a relict sand spit that formed during a period of relatively slower sea-level rise (Younger Dryas stadial) in the latest Pleistocene. This sand spit crossed an embayment and connected a western fault-bounded bedrock peninsula and an eastern bedrock highland, a paleogeography similar to modern geomorphology along coastal segments of the San Andreas fault. Detailed analysis of the relict shoreface with slope profiles and slope maps indicates a lateral slip rate of 2.6 ± 0.9 mm/yr. Because the Hosgri fault locally includes an active western strand, and regionally converges with several other faults, this slip rate should be considered a minimum for the Hosgri fault in central California and should not be applied for the entire Hosgri-San Gregorio fault system. This slip rate indicates that the Hosgri system takes up the largest share of the strike-slip fault budget and is the most active strike-slip fault west of the San Andreas fault in central California. This result further demonstrates the value and potential of high-resolution bathymetry in earthquake-hazard characterization of active offshore faults.

  12. Transformation of fault slip modes in laboratory experiments

    Science.gov (United States)

    Martynov, Vasilii; Alexey, Ostapchuk; Markov, Vadim

    2017-04-01

    Slip mode of crust fault can vary because of many reasons. It's well known that fault structure, material of fault gouge, pore fluid et al. in many ways determines slip modes from creep and slow slip events to mega-earthquakes [1-3]. Therefore, the possibility of fault slip transformation due to external action is urgent question. There is popular and developing approach of fluid injection into central part of fault. The phenomenon of earthquakes induced due to pumping of water was investigated on small and large scales [4, 5]. In this work the laboratory experiments were conducted to study the evolution of the experimental fault slip when changing the properties of the interstitial fluid. The scheme of experiments is the classical slider-model set-up, in which the block under the shear force slips along the interface. In our experiments the plexiglas block 8x8x3 cm3 in size was put on the plexiglas base. The contact of the blocks was filled with a thin layer (about 3 mm thick) of a granular material. The normal load varied from 31 to 156 kPa. The shear load was applied through a spring with stiffness 60 kN/m, and the rate of spring deformation was 20 or 5 mcm/s. Two parameters were recorded during experiments: the shear force acting on the upper block (with an accuracy of 1 N) and its displacement relatively the base (with an accuracy of 0.1 μm). The gouge was composed of quartz sand (97.5%) and clay (2.5%). As a moisturizer were used different fluids with viscosity varying from 1 to 103 mPa x s. Different slip modes were simulated during slider-experiments. In our experiments slip mode is the act of instability manifested in an increase of slip velocity and a drop of shear stress acting on a movable block. The amplitude of a shear stress drop and the peak velocity of the upper block were chosen as the characteristics of the slip mode. In the laboratory experiments, slip events of one type can be achieved either as regularly recurring (regular mode) or as random

  13. Effect of the dose of oral Hydrocortisone on growth rate during long-term treatment of children with salt losing congenital adrenal hyperplasia

    Directory of Open Access Journals (Sweden)

    M. Ciaccio

    2002-12-01

    Full Text Available The effect of the dose of oral hydrocortisone on stature growth rate of patients with the salt losing form of congenital adrenal hyperplasia and adequate electrolyte balance was here assessed. Thirty patients (21 girls and 9 boys were followed longitudinally for 0.52 to 8.64 years, between chronological ages 0.35 and 8.64 years. Nine consecutive periods (Ps of follow up were defined in order to compare two auxological parameters, height (H at the end of a follow up P and DH standard deviation score (SDS. According to growth rate during a particular P, two types of Ps were defined: Ps with DH SDS > -0.5 (Group 1, satisfactory growth rate and Ps with DH SDS = or 18 mg/m²/day and grew poorly, but they were able to recover, at least temporarily, when the dose was adjusted during the following years.

  14. PTHA Slip Models in the Aftermath of the 2011 Tohoku Earthquake and Tsunami

    Science.gov (United States)

    Geist, E. L.; Parsons, T.; Oglesby, D. D.

    2011-12-01

    Inter-plate thrust slip models used in Probabilistic Tsunami Hazard Analysis (PTHA) are re-evaluated in light of the 2011 Tohoku earthquake and tsunami. Whereas recurrence is typically linked to seismic moment in PTHA, the magnitude and distribution of slip are the primary variables that affect tsunami generation. Because of the self-similar nature of rupture, the slip model is dependent on other scaling relationships, such as magnitude-area and magnitude-mean slip. In the past, various slip models have been used to calculate tsunami generation, ranging from uniform slip to stochastic models. Uniform slip models systematically underestimate the amplitude and leading-wave steepness for the local, broadside tsunami. Stochastic slip models, constrained by the seismic displacement spectrum, produce a range of possible slip distributions for a given seismic moment and slip spectrum and more accurately represent heterogeneous earthquake ruptures. Conventional stochastic slip models based on a k-2 slip spectrum and Gaussian random variables result in a coefficient of variation (c.v.) approximately equal to 0.5. However, slip inversion results of recent tsunamigenic earthquakes indicate that the observed c.v. is significantly greater than 0.5. This is particularly evident for the 2011 Tohoku earthquake, in which the c.v. for slip is approximately 1.0. Recent updates to the stochastic slip model can retain a k-2 slip spectrum, but use non-Gaussian distributed random variables. The updated stochastic slip model is more consistent with the observed fluctuations in slip. We investigate how these models can be applied in a PTHA framework. In addition, dynamic effects such as amplification of slip near the free surface, partitioning of slip between different overlapping fault segments, and dynamic overshoot can strongly modify the slip pattern in ways that may be correlated with geometrical and frictional properties on the fault; such effects potentially may be predictable prior

  15. Sensitivity of vehicle handling to combined slip tyre characteristics

    NARCIS (Netherlands)

    Jansen, S.T.H.; Oosten, J.J.M. van; Pacejka, H.B.; Pauwelussen, J.P.

    1996-01-01

    The sensitivity of vehicle handling to combined slip tyre characteristics is investigated using two simulation models with different interaction between lateral and longitudinal tyre forces. The standard method for the braking in a turn test is simulated with both models, and differences in the outc

  16. Friction at seismic slip rates: testing thermal weakening models experimentally

    Science.gov (United States)

    Nielsen, S. B.; Spagnuolo, E.; Violay, M.; Di Toro, G.

    2013-12-01

    Recent experiments systematically explore rock friction under crustal earthquake conditions (fast slip rate 1desing an efficient and accurate wavenumber approximation for a solution of the temperature evolution on the fault. Finally, we propose a compact and paractical model based on a small number of memory variables for the implementation of thermal weakening friction in seismic fault simulations.

  17. Quantifying effective slip length over micropatterned hydrophobic surfaces

    NARCIS (Netherlands)

    Tsai, Peichun; Peters, Alisia M.; Pirat, Christophe; Wessling, Matthias; Lammertink, Rob G.H.; Lohse, Detlef

    2009-01-01

    We employ microparticle image velocimetry to investigate laminar microflows in hydrophobic microstructured channels, in particular the slip length. These microchannels consist of longitudinal microgrooves, which can trap air and prompt a shear-free boundary condition and thus slippage enhancement. O

  18. Analysing earthquake slip models with the spatial prediction comparison test

    KAUST Repository

    Zhang, L.

    2014-11-10

    Earthquake rupture models inferred from inversions of geophysical and/or geodetic data exhibit remarkable variability due to uncertainties in modelling assumptions, the use of different inversion algorithms, or variations in data selection and data processing. A robust statistical comparison of different rupture models obtained for a single earthquake is needed to quantify the intra-event variability, both for benchmark exercises and for real earthquakes. The same approach may be useful to characterize (dis-)similarities in events that are typically grouped into a common class of events (e.g. moderate-size crustal strike-slip earthquakes or tsunamigenic large subduction earthquakes). For this purpose, we examine the performance of the spatial prediction comparison test (SPCT), a statistical test developed to compare spatial (random) fields by means of a chosen loss function that describes an error relation between a 2-D field (‘model’) and a reference model. We implement and calibrate the SPCT approach for a suite of synthetic 2-D slip distributions, generated as spatial random fields with various characteristics, and then apply the method to results of a benchmark inversion exercise with known solution. We find the SPCT to be sensitive to different spatial correlations lengths, and different heterogeneity levels of the slip distributions. The SPCT approach proves to be a simple and effective tool for ranking the slip models with respect to a reference model.

  19. Determination of the of rate cross slip of screw dislocations

    DEFF Research Database (Denmark)

    Vegge, Tejs; Rasmussen, Torben; Leffers, Torben;

    2000-01-01

    The rate for cross slip of screw dislocations during annihilation of screw dipoles in copper is determined by molecular dynamics simulations. The temperature dependence of the rate is seen to obey an Arrhenius behavior in the investigated temperature range: 225-375 K. The activation energy...

  20. Interfacial Slip in Soap Films with Hydrosoluble Polymer

    Science.gov (United States)

    Adelizzi, E. A.; Berg, S.; Troian, S. M.

    2003-11-01

    The thickness of a Newtonian soap film entrained at small capillary number should scale as Ca^2/3 provided the bounding surfaces are rigid. Previous studies show that soap films containing associating, low concentration, high molecular weight (M_w) polymer exhibit strong deviations from this scaling. We report results by laser interferometry of the entrained film thickness for the associating pair SDS/PEO over a large range in polymer molecular weight. Direct comparison to predictions of hydrodynamic models based on viscoelastic behavior shows poor agreement.Modification of the Frankel analysis to account for mobile films through a Navier slip condition yields good agreement. In addition, the slip length Ls increases as M_w^3/5, consistent with a correlation based on a polymer chain size for freely jointed chains with excluded volume effects. Although developed to explain slip at liquid-solid interfaces, the Tolstoi-Larson prediction that Ls scales as the polymer size agrees favorably with our results. Whether the slip behavior is due to Marangoni effects cannot be ruled out.

  1. Investigation of torque control using a variable slip induction generator

    Energy Technology Data Exchange (ETDEWEB)

    Bossanyi, E.A.; Gamble, C.R.

    1991-07-01

    An investigation of the possibilities of using a variable slip induction generator to control wind turbine transmission torque has been carried out. Such a generator consists of a wound rotor induction generator with its rotor winding connected to an external variable resistance circuit. By controlling the external resistance, the torque-slip characteristic of the generator can be modified, allowing efficient, low-slip operation below rated wind speed and compliant, high-slip operation above rated, where the additional losses are of no consequence but the resulting compliance allows a much reduced duty to be specified for the transmission and gearbox. A number of hardware options have been investigated for the variable resistance rotor circuit, the main options being either a rectifier and DC chopper or an AC regulator. Both of these options use semiconductor switching devices, for which the relative merits of thyristors, MOSFETs, GTOs and transistors have been investigated. A favoured scheme consisting of an AC regulator using GTOs has been provisionally selected. This choice uses some non-standard equipment but is expected to give negligible problems with harmonics. A comprehensive simulation model has been set up and used to investigate the behaviour of the whole system. (author).

  2. Dynamic Action Units Slip in Speech Production Errors

    Science.gov (United States)

    Goldstein, Louis; Pouplier, Marianne; Chen, Larissa; Saltzman, Elliot; Byrd, Dani

    2007-01-01

    In the past, the nature of the compositional units proposed for spoken language has largely diverged from the types of control units pursued in the domains of other skilled motor tasks. A classic source of evidence as to the units structuring speech has been patterns observed in speech errors--"slips of the tongue". The present study reports, for…

  3. Slip and flow dynamics of polydisperse thin polystyrene films.

    Science.gov (United States)

    Sabzevari, Seyed Mostafa; McGraw, Joshua D.; Jacobs, Karin; Wood-Adams, Paula M.

    2015-03-01

    We investigate the slip of binary and ternary mixtures of nearly monodisperse polystyrene samples on Teflon-coated (AF2400) silicon wafers using dewetting experiments. Binary mixtures of long and short chains along with ternary mixtures with a fixed weight-average molecular weight Mw but different number-average molecular weight Mn were prepared. Thin films of ca. 200 nm were spin coated on mica from polymer solutions and transferred to Teflon substrates. Above the glass transition temperature Tg the films break up via nucleation and growth of holes. The hole growth rate and rim morphology are monitored as a function of Mn and annealing protocol of the films before transfer to Teflon substrates. Slip properties, accessed using hydrodynamic models, and flow dynamics are then examined and compared. We found that the rim morphology and slip of polystyrene blends on Teflon depends on the molecular weight distribution. Similarly, flow dynamics is affected by the presence of short chains in mixture. Moreover, we can provoke differences in slip by choosing appropriate annealing and film transfer protocols for PS films that have first been spin cast on mica surfaces.

  4. Analytical solutions for squeeze flow with partial wall slip

    DEFF Research Database (Denmark)

    Laun, HM; Rady, M; Hassager, Ole

    1999-01-01

    Squeeze flow between parallel plates of a purely viscous material is considered for small gaps both for a Newtonian and power law fluid with partial wall slip. The results for the squeeze force as a function of the squeezing speed reduce to the Stefan and Scott equations in the no slip limit......, respectively. The slip velocity at the plate increases linearly with the radius up to the rim slip velocity upsilon(s). For small Saps H, the resulting apparent Newtonian rim shear rate-measured for a constant rim shear stress, i.e. an imposed force increasing proportional to 1/H-yields a straight line...... if plotted versus 1/H. The slope of the straight line is equal to 6 upsilon(s) whereas the intersect with the ordinate yields the effective Newtonian rim shear rate to be converted into the true rim shear rate by means of the power law exponent. The advantage of the new technique is the separation of bulk...

  5. Nucleation and growth of strike slip faults in granite.

    Science.gov (United States)

    Segall, P.; Pollard, D.P.

    1983-01-01

    Fractures within granodiorite of the central Sierra Nevada, California, were studied to elucidate the mechanics of faulting in crystalline rocks, with emphasis on the nucleation of new fault surfaces and their subsequent propagation and growth. Within the study area the fractures form a single, subparallel array which strikes N50o-70oE and dips steeply to the S. Some of these fractures are identified as joints because displacements across the fracture surfaces exhibit dilation but no slip. The joints are filled with undeformed minerals, including epidote and chlorite. Other fractures are identified as small faults because they display left-lateral strike slip separations of up to 2m. Slickensides, developed on fault surfaces, plunge 0o-20o to the E. The faults occur parallel to, and in the same outcrop with, the joints. The faults are filled with epidote, chlorite, and quartz, which exhibit textural evidence of shear deformation. These observations indicate that the strike slip faults nucleated on earlier formed, mineral filled joints. Secondary, dilational fractures propagated from near the ends of some small faults contemporaneously with the left-lateral slip on the faults. These fractures trend 25o+ or -10o from the fault planes, parallel to the direction of inferred local maximum compressive stress. The faults did not propagate into intact rock in their own planes as shear fractures. -from Authors

  6. On the Modeling of Contact Interfaces with Frictional Slips

    Directory of Open Access Journals (Sweden)

    Ligia Munteanu

    2013-09-01

    Full Text Available The paper analyses the contact interfaces between the scatterers and the matrix into the sonic composites, in the presence of the frictional slips. The sonic composite is a sonic liner designed in order to provide suppression of unwanted noise for jet engines, with emphases on the nacelle of turbofan engines for commercial aircraft.

  7. Scaling of the critical slip distance in granular layers

    CERN Document Server

    Hatano, Takahiro

    2009-01-01

    We investigate the nature of friction in granular layers by means of numerical simulation focusing on the critical slip distance, over which the system relaxes to a new stationary state. Analyzing a transient process in which the sliding velocity is instantaneously changed, we find that the critical slip distance is proportional to the sliding velocity. We thus define the relaxation time, which is independent of the sliding velocity. It is found that the relaxation time is proportional to the layer thickness and inversely proportional to the square root of the pressure. An evolution law for the relaxation process is proposed, which does not contain any length constants describing the surface geometry but the relaxation time of the bulk granular matter. As a result, the critical slip distance is scaled with a typical length scale of a system. It is proportional to the layer thickness in an instantaneous velocity change experiment, whereas it is scaled with the total slip distance in a spring-block system on gr...

  8. Evidence Based Prevention of Occupational Slips, Trips and Falls

    DEFF Research Database (Denmark)

    Jensen, Olaf Chresten

    2009-01-01

    It is estimated that about one third of the compensated occupational injuries and half of the most serious occupational injuries in merchant seafaring are related to slips, trips and falls (STF)-events. Among the elderly, STF is the risk factor that causes the largest number of inpatient days...

  9. Micro-vibration-based slip detection in tactile force sensors.

    Science.gov (United States)

    Fernandez, Raul; Payo, Ismael; Vazquez, Andres S; Becedas, Jonathan

    2014-01-03

    Tactile sensing provides critical information, such as force, texture, shape or temperature, in manipulation tasks. In particular, tactile sensors traditionally used in robotics are emphasized in contact force determination for grasping control and object recognition. Nevertheless, slip detection is also crucial to successfully manipulate an object. Several approaches have appeared to detect slipping, the majority being a combination of complex sensors with complex algorithms. In this paper, we deal with simplicity, analyzing how a novel, but simple, algorithm, based on micro-vibration detection, can be used in a simple, but low-cost and durable, force sensor. We also analyze the results of using the same principle to detect slipping in other force sensors based on flexible parts. In particular, we show and compare the slip detection with: (i) a flexible finger, designed by the authors, acting as a force sensor; (ii) the finger torque sensor of a commercial robotic hand; (iii) a commercial six-axis force sensor mounted on the wrist of a robot; and (iv) a fingertip piezoresistive matrix sensor.

  10. Flash Heating of Crustal Rocks at Seismic Slip Rates

    Science.gov (United States)

    Goldsby, D. L.; Spagnuolo, E.; Smith, S. A.; Beeler, N. M.; Tullis, T. E.; Di Toro, G.; Nielsen, S. B.

    2012-12-01

    Recent experiments have demonstrated that rocks undergo extreme frictional weakening at near-earthquake slip rates due to the thermal degradation of the strength, or even melting, of microscopic asperity contacts on their sliding surfaces (Goldsby and Tullis, 2012). These previous experiments, conducted at constant normal stress and slip rates of up to ~0.4 m/s, revealed a 1/V dependence of friction on slip rate above a characteristic weakening velocity, Vw, in accord with theories of flash heating (e.g., Rice, 2006). The weakening velocity obtains values of ~0.1 m/s for many crustal silicate rocks (Goldsby and Tullis, 2012). Here we test two further predictions of flash-heating theory - that the degree of weakening saturates at slip rates approaching 1 m/s, and that the weakening behavior due to flash heating is independent of normal stress - by testing samples at slip rates of up to 1 m/s at different normal stresses. Experiments were conducted in a 1-atm, high-velocity friction apparatus at the Istituto Nazionale di Geofisica e Vulcanologia in Rome. A sample consisted of a pair of hollow cylinders of Westerly granite or Frederick diabase subjected to a nominally constant normal stress of from 1 to 30 MPa and subjected to a variety of rate-stepping sequences. Data were acquired at rates of up to 1 MHz. As predicted, the experiments demonstrate that the degree of weakening due to flash heating saturates at slip rates approaching 1 m/s; in a few cases, friction even increases slightly with increasing slip rate near 1 m/s. The experiments also demonstrate that, within the scatter of the data, the value of Vw and the friction coefficient in the weakened state is independent of normal stress, the expected result if average contact sizes and contact stresses are independent of normal stress. The data thus further corroborate existing theories and experimental data for flash heating, allowing for a more reliable determination of the conditions under which flash heating

  11. The 3-D surface deformation, coseismic fault slip and after-slip of the 2010 Mw6.9 Yushu earthquake, Tibet, China

    Science.gov (United States)

    Zhang, Guohong; Shan, Xinjian; Feng, Guangcai

    2016-07-01

    Using SAR interferometry on C band Envisat descending track and L band ALOS ascending track SAR images, respectively, we firstly obtain two coseismic deformation fields and one postseismic deformation of the 2010 Yushu earthquake, Tibet, China. In the meanwhile, we also obtain the azimuthal coseismic deformation of the Yushu event by Multi Aperture Interferometry (MAI) technique. With the 3 components of one-dimensional coseismic InSAR measurements, we resolve the complete 3-dimensional deformation of the 2010 Yushu event, which shows conformity and complexity to left lateral slip mechanism. The horizontal deformation is basically consistent with a sinistral slip event; whereas the vertical displacement does show certain level of complexity, which we argue is indicative of local fault geometry variation. Based on the InSAR data and elastic dislocation assumption, we invert for coseismic fault slip and early after-slip of the Yushu event. Our inversion results show major coseismic left lateral strike slip with only minor thrust component. The after-slip model fills most of the slip gaps left by the coseismic fault slip and finds a complementary slip distribution to the coseismic fault slip, which is a good indicator that future earthquake potential on the Yushu segment has been significantly reduced.

  12. Direct measurement of wall slip and slip layer thickness of non-Brownian hard-sphere suspensions in rectangular channel flows

    Science.gov (United States)

    Jesinghausen, Steffen; Weiffen, Rene; Schmid, Hans-Joachim

    2016-09-01

    Wall slip is a long-known phenomenon in the field of rheology. Nevertheless, the origin and the evolution are not completely clear yet. Regarding suspensions, the effect becomes even more complicated, because different mechanisms like pure slip or slip due to particle migration have to be taken into account. Furthermore, suspensions themselves show many flow anomalies and the isolation of slip is complicated. In order to develop working physical models, further insight is necessary. In this work, we measured experimentally the wall slip velocities of different highly filled suspensions in a rectangular slit die directly with respect to the particle concentration and the particle size. The slip velocities were obtained using a particle image velocimetry (PIV) system. The suspensions consisting of a castor oil-cinnamon oil blend and PMMA particles were matched in terms of refractive indexes to appear transparent. Hereby, possible optical path lengths larger than 15 mm were achieved. The slip velocities were found to be in a quadratic relation to the wall shear stress. Furthermore, the overall flow rate as well as the particle concentration has a direct influence on the slip. Concerning the shear stress, there seem to be two regions of slip with different physical characteristics. Furthermore, we estimated the slip layer thickness directly from the velocity profiles and propose a new interpretation. The PIV technique is used to investigate the viscosity and implicit the concentration profile in the slit die. It is shown that the particle migration process is quite fast.

  13. Comparisons of Limit Analysis Solutions and Random Search Solutions on Slope Critical Slip SUrface

    Institute of Scientific and Technical Information of China (English)

    JianfengWANG

    1998-01-01

    The object of this paper is twofold:to present a kinematics limit analysis for assessing the safety of slope or its critical slip surface,and to compare the searched slip surface with that by limit analysis.

  14. Quasi-steady-state linearisation of the racing vehicle acceleration envelope: a limited slip differential example

    Science.gov (United States)

    Tremlett, A. J.; Assadian, F.; Purdy, D. J.; Vaughan, N.; Moore, A. P.; Halley, M.

    2014-11-01

    In the motorsport environment, passive limited slip differentials are a well-established means of improving the traction limitation imposed by the open differential. Torque sensing types are highly adjustable, and can alter both the stability and agility of the vehicle in the various cornering phases of a typical manoeuvre. In this paper, an adjustable clutch plate or 'Salisbury' differential model is presented, which can significantly alter its torque bias characteristics through adjustments in the drive/coast ramp angle, the number of friction faces and preload. To allow robust evaluation of differential parameter changes on ultimate vehicle performance and handling balance, a unified acceleration or 'GG' diagram framework is then described. This builds on traditional GG diagram approaches, by using nonlinear constrained optimisation to define both the vehicle acceleration limits and a 'feasibility' region within the performance envelope. By linearising a seven degrees of freedom vehicle model at multiple operating points, eigenvalue and yaw rate response analysis is then used to establish contours of stability and agility throughout the GG envelope. This brings new insights into the way in which handling balance changes below and up to the vehicle's acceleration limits.

  15. A slow slip event along the northern Ecuadorian subduction zone

    Science.gov (United States)

    Nocquet, J.; Mothes, P. A.; Vallee, M.; Regnier, M.

    2009-12-01

    Rapid subduction of the Nazca plate beneath the Ecuador-Colombia margin (~58 mm/yr) has produced one of the largest megathrust earthquake sequence during the last century. The 500-km-long rupture zone of the 1906 (Mw = 8.8) event was partially reactivated by three thrust events; in 1942 (Mw = 7.8), 1958 (Mw = 7.7), and 1979 (Mw = 8.2), whose rupture zones abut one another. New continuously-recording GPS stations installed along the Ecuadorian coast, together with campaign sites observed since 1994 indicate that the current velocities results from the superimposition of a NNE motion the crustal North Andean Block occurring at ~8 mm/yr in Ecuador and the elastic deformation involved by partial locking of the subduction interface. We first estimate the long-term kinematics of the North Andean block in a joint inversion including GPS data, earthquake slip vectors and quaternary slip rates on major faults. The inversion provides a Euler pole located at long. -107.8°E, lat. 36.2°N, 0.091°/Ma and indicates little internal deformation of the North Andean Block (wrms=1.3 mm/yr). Residual velocities with respect to the North Andean Block are then modeled in terms of elastic locking along the subduction interface. Models indicate that the subduction interface is partially locked (50%) up to a depth of 40 km. Finally, we report a transient event that occurred in early 2008 near the Ecuador-Colombia border. The magnitude of the trenchward displacement is 13 mm, with uplift of similar magnitude. While the total duration of the slip event is 5 months, the horizontal time series clearly shows two sub-phases of slip with approximatively similar magnitud of displacement and duration, separated by 6 weeks. Modelling indicates that the slip occurs at 40 km depth, immediately below downdip extension of the locked zone.

  16. Slip and fall risk on ice and snow:identification, evaluation and prevention

    OpenAIRE

    Gao, Chuansi

    2004-01-01

    Slip and fall accidents and associated injuries on ice and snow are prevalent among outdoor workers and the general public in winter in many regions of the world. To understand and tackle this multi-factorial problem, a multidisciplinary approach was used to identify and evaluate slip and fall risks, and to propose recommendations for prevention of slips and falls on icy and snowy surfaces. Objectives were to present a systems perspective of slip and fall accidents and related risk factors; t...

  17. Functional balance tests

    Directory of Open Access Journals (Sweden)

    Parvin Raji

    2012-12-01

    Full Text Available Background and Aim: All activities of daily living need to balance control in static and dynamic movements. In recent years, a numerous increase can be seen in the functional balance assessment tools. Functional balance tests emphasize on static and dynamic balance, balance in weight transfer, the equilibrium response to the imbalances, and functional mobility. These standardized and available tests assess performance and require minimal or no equipment and short time to run. Functional balance is prerequisite for the most static and dynamic activities in daily life and needs sufficient interaction between sensory and motor systems. According to the critical role of balance in everyday life, and wide application of functional balance tests in the diagnosis and assessment of patients, a review of the functional balance tests was performed.Methods: The Google Scholar, PubMed, Science Direct, Scopus, Magiran, Iran Medex, and IranDoc databases were reviewed and the reliable and valid tests which were mostly used by Iranian researchers were assessed.Conclusion: It seems that Berg balance scale (BBS have been studied by Iranian and foreign researches more than the other tests. This test has high reliability and validity in elderly and in the most neurological disorders.

  18. Development of Severe Hyponatremia due to Salt-Losing Nephropathy after Esophagectomy for Esophageal Cancer

    Directory of Open Access Journals (Sweden)

    Katsunobu Yoshioka

    2009-01-01

    Full Text Available A 72-year-old woman was admitted to our hospital for esophagectomy for esophageal cancer. On the third postoperative day, she developed polyuria (3.8 L/day, massive natriuresis, hyponatremia (112 mEq/L, hyperkalemia (5.6 mEq/L, and decreased central venous pressure, which was refractory to isotonic saline infusion. Laboratory findings indicated proximal tubular injury (high urinary β2-microglobulin, coexistence of hypouricemia together with reduced aldosterone action at the cortical collecting duct. A diagnosis of salt-losing nephropathy was made and sodium correction was done with 3% saline and fludrocortisone. She responded well to therapy. The cause of hyponatremia was considered renal tubular dysfunction together with elevated antidiuretic hormone level. Postoperatively, it is important to look for the development of salt-losing nephropathy.

  19. Losing one twin in the NICU - A case study of parental experience

    DEFF Research Database (Denmark)

    Aagaard, Hanne; Storm, Ida; Klitgaard, Jeannett

    2016-01-01

    and revealed tree overall themes. These themes indicate that besides struggling with grief related to the loss of one infant, the parents were challenged by the medical discourse, the lack of staff continuity and space to develop parenthood. This case study emphasizes how the loss of a premature twin......The aim of this case study was to generate a deeper understanding of parents’ experiences of losing one twin in the NICU. In an in-depth interview the parents told their story of giving birth to twins born extremely preterm and shortly after losing one of them. A thematic analysis was conducted...... reinforced the parents’ need of an understandable dialogue with a team of nurses. Furthermore the nurses have to offer a close partnership and create the necessary space for parents to develop parenthood while simultaneously dealing with the unexpected and traumatising circumstances related to the loss...

  20. Win-stay lose-shift strategy in formation changes in football

    CERN Document Server

    Tamura, Kohei

    2015-01-01

    Managerial decision making is likely to be a dominant determinant of performance of teams in team sports. Here we use Japanese and German football data to investigate correlates between temporal patterns of formation changes across matches and match results. We found that individual teams and managers both showed win-stay lose-shift behavior, a type of reinforcement learning. In other words, they tended to stick to the current formation after a win and switch to a different formation after a loss. In addition, formation changes did not affect the results of succeeding matches in most cases. The results indicate that a swift implementation of a new formation in the win-stay lose-shift manner may not be a successful managerial rule of thumb.

  1. Giardia infection: Protein-losing enteropathy in an adult with immunodeficiency

    Institute of Scientific and Technical Information of China (English)

    Alexandre Khodr Furtado; Virginia Lucia Ribeiro Cabral; Thiago Nunes Santos; Eli Mansour; Cristiane Kibune Nagasako; Sonia Leticia Lorena; Rogerio Antunes Pereira-Filho

    2012-01-01

    The case of a 52-year-old woman with a past history of thymoma resection who presented with chronic diarrhea and generalized edema is the focal point of this article.A diagnosis of Giardia lamblia infection was established,which was complicated by protein-losing enteropathy and severely low serum protein level in a patient with no urinary protein loss and normal liver function.After anti-helmintic treatment,there was recovery from hypoalbuminemia,though immunoglobulins persisted at low serum levels leading to the hypothesis of an immune system disorder.Good's syndrome is a rare cause of immunodeficiency characterized by the association of hypogammaglobulinemia and thymoma.This primary immune disorder may be complicated by severe infectious diarrhea secondary to disabled humoral and cellular immune response.This is the first description in the literature of an adult patient with an immunodeficiency syndrome who presented with protein-losing enteropathy secondary to giardiasis.

  2. The effect of losing and gaining flow conditions on hyporheic exchange in heterogeneous streambeds

    Science.gov (United States)

    Fox, A.; Laube, G.; Schmidt, C.; Fleckenstein, J. H.; Arnon, S.

    2016-09-01

    Bed form-induced hyporheic exchange flux (qH) is increasingly viewed as a key process controlling water fluxes and biogeochemical processes in river networks. Despite the fact that streambeds are inherently heterogeneous, the majority of bed form flume-scale studies were done on homogeneous systems. We conducted salt and dye tracer experiments to study the effects of losing and gaining flow conditions on qH using a laboratory recirculating flume system packed with a heterogeneous streambed, and equipped with a drainage system that enabled us to apply losing or gaining fluxes. We found that when either losing or gaining fluxes increased (regardless of whether the flux was upward or downward), qH followed an exponential decline, the volume of the hyporheic flow cell drastically reduced, and the mean residence times declined moderately. A numerical flow model for the heterogeneous streambed was set up and fitted against the experimental data in order to test whether an equivalent homogeneous case exists. The measured qH were accurately predicted with the heterogeneous model, while it was underestimated using a homogeneous model characterized by the geometric mean of the hydraulic conductivity. It was also shown that in order to produce the results of the heterogeneous model with an equivalent hydraulic conductivity, the latter had to be increased as the losing or gaining fluxes increase. The results strongly suggest that it is critical to adequately account for the heterogeneous streambed structure in order to accurately predict the effect of vertical exchange fluxes between the stream and groundwater on hyporheic exchange.

  3. Innovation in multi–channel retail banking. The bank wins or loses customers

    OpenAIRE

    Gentiana Gjino; Orkida Ilollari

    2012-01-01

    'For many institutions, Internet is a dilemma. Embrace it and still will find yourself losing ground in your business or at least, can see your earnings falter. But ignoring it can be fatal' (The Economist) New technologies are changing the functionality of society and its various components: from one person to multinational companies. We are facing a complete change of paradigm not in vertical type, which belongs to a single sector, but the indirect type. If in the first case it is essential...

  4. Role of multiscale heterogeneity in fault slip from quasi-static numerical simulations

    Science.gov (United States)

    Aochi, Hideo; Ide, Satoshi

    2017-07-01

    Quasi-static numerical simulations of slip along a fault interface characterized by multiscale heterogeneity (fractal patch model) are carried out under the assumption that the characteristic distance in the slip-dependent frictional law is scale-dependent. We also consider slip-dependent stress accumulation on patches prior to the weakening process. When two patches of different size are superposed, the slip rate of the smaller patch is reduced when the stress is increased on the surrounding large patch. In the case of many patches over a range of scales, the slip rate on the smaller patches becomes significant in terms of both its amplitude and frequency. Peaks in slip rate are controlled by the surrounding larger patches, which may also be responsible for the segmentation of slip sequences. The use of an explicit slip-strengthening-then-weakening frictional behavior highlights that the strengthening process behind small patches weakens their interaction and reduces the peaks in slip rate, while the slip deficit continues to accumulate in the background. Therefore, it may be possible to image the progress of slip deficit at larger scales if the changes in slip activity on small patches are detectable.

  5. Stick-slip to sliding transition of dynamic contact lines under AC electrowetting

    NARCIS (Netherlands)

    Mannetje, 't D.J.C.M.; Mugele, F.; Ende, van den D.

    2013-01-01

    We show that at low velocities the dynamics of a contact line of a water drop moving over a Teflon-like surface under ac electrowetting must be described as stick–slip motion, rather than one continuous movement. At high velocities we observe a transition to a slipping regime. In the slipping regime

  6. Seizures Associated With Hypocalcemia in a Yorkshire Terrier With Protein-Losing Enteropathy.

    Science.gov (United States)

    Whitehead, Jim; Quimby, Jessica; Bayliss, Danielle

    2015-01-01

    A 7 yr old, male, castrated, Yorkshire terrier was presented on emergency for an acute onset of seizure activity. The owner also reported that the dog had previously exhibited other symptoms, including intermittent vomiting, diarrhea, and anorexia for several yr. The initial workup revealed a marked decrease in ionized calcium and total protein. Further diagnostics revealed decreases in magnesium, 25 hydroxyvitamin D, albumin, and globulins, and an increased parathyroid hormone level. Intestinal biopsies revealed inflammatory bowel disease and lymphangiectasia. The dog received intravenous calcium gluconate for treatment of hypocalcemia followed by oral calcium and vitamin D supplementation. Seizure activity ceased once calcium levels approached the normal range. Medical and dietary therapy for lymphangiectasia and inflammatory bowel disease consisted of prednisone, rutin, and a low-fat diet. Decreased serum total ionized calcium levels have been reported previously in dogs with protein-losing enteropathies. Typically, the hypocalcemia is not associated with clinical signs. Severe clinical signs of hypocalcemia are rarely reported in dogs with protein-losing enteropathy, but seizures, facial twitching, and tremors can occur. When presented with a dog with a history of seizure activity, panhypoproteinemia, and hypocalcemia, protein-losing enteropathy should be included on the list of differential diagnoses.

  7. Winning and losing tree species of reassembly in Minnesota's mixed and broadleaf forests.

    Science.gov (United States)

    Hanberry, Brice B; Palik, Brian J; He, Hong S

    2013-01-01

    We examined reassembly of winning and losing tree species, species traits including shade and fire tolerance, and associated disturbance filters and forest ecosystem types due to rapid forest change in the Great Lakes region since 1850. We identified winning and losing species by changes in composition, distribution, and site factors between historical and current surveys in Minnesota's mixed and broadleaf forests. In the Laurentian Mixed Forest, shade-intolerant aspen replaced shade-intolerant tamarack as the most dominant tree species. Fire-tolerant white pine and jack pine decreased, whereas shade-tolerant ashes, maples, and white cedar increased. In the Eastern Broadleaf Forest, fire-tolerant white oaks and red oaks decreased, while shade-tolerant ashes, American basswood, and maples increased. Tamarack, pines, and oaks have become restricted to sites with either wetter or sandier and drier soils due to increases in aspen and shade-tolerant, fire-sensitive species on mesic sites. The proportion of shade-tolerant species increased in both regions, but selective harvest reduced the applicability of functional groups alone to specify winners and losers. Harvest and existing forestry practices supported aspen dominance in mixed forests, although without aspen forestry and with fire suppression, mixed forests will transition to a greater composition of shade-tolerant species, converging to forests similar to broadleaf forests. A functional group framework provided a perspective of winning and losing species and traits, selective filters, and forest ecosystems that can be generalized to other regions, regardless of species identity.

  8. Winning and Losing Tree Species of Reassembly in Minnesota’s Mixed and Broadleaf Forests

    Science.gov (United States)

    Hanberry, Brice B.; Palik, Brian J.; He, Hong S.

    2013-01-01

    We examined reassembly of winning and losing tree species, species traits including shade and fire tolerance, and associated disturbance filters and forest ecosystem types due to rapid forest change in the Great Lakes region since 1850. We identified winning and losing species by changes in composition, distribution, and site factors between historical and current surveys in Minnesota’s mixed and broadleaf forests. In the Laurentian Mixed Forest, shade-intolerant aspen replaced shade-intolerant tamarack as the most dominant tree species. Fire-tolerant white pine and jack pine decreased, whereas shade-tolerant ashes, maples, and white cedar increased. In the Eastern Broadleaf Forest, fire-tolerant white oaks and red oaks decreased, while shade-tolerant ashes, American basswood, and maples increased. Tamarack, pines, and oaks have become restricted to sites with either wetter or sandier and drier soils due to increases in aspen and shade-tolerant, fire-sensitive species on mesic sites. The proportion of shade-tolerant species increased in both regions, but selective harvest reduced the applicability of functional groups alone to specify winners and losers. Harvest and existing forestry practices supported aspen dominance in mixed forests, although without aspen forestry and with fire suppression, mixed forests will transition to a greater composition of shade-tolerant species, converging to forests similar to broadleaf forests. A functional group framework provided a perspective of winning and losing species and traits, selective filters, and forest ecosystems that can be generalized to other regions, regardless of species identity. PMID:23613911

  9. Winning and losing tree species of reassembly in Minnesota's mixed and broadleaf forests.

    Directory of Open Access Journals (Sweden)

    Brice B Hanberry

    Full Text Available We examined reassembly of winning and losing tree species, species traits including shade and fire tolerance, and associated disturbance filters and forest ecosystem types due to rapid forest change in the Great Lakes region since 1850. We identified winning and losing species by changes in composition, distribution, and site factors between historical and current surveys in Minnesota's mixed and broadleaf forests. In the Laurentian Mixed Forest, shade-intolerant aspen replaced shade-intolerant tamarack as the most dominant tree species. Fire-tolerant white pine and jack pine decreased, whereas shade-tolerant ashes, maples, and white cedar increased. In the Eastern Broadleaf Forest, fire-tolerant white oaks and red oaks decreased, while shade-tolerant ashes, American basswood, and maples increased. Tamarack, pines, and oaks have become restricted to sites with either wetter or sandier and drier soils due to increases in aspen and shade-tolerant, fire-sensitive species on mesic sites. The proportion of shade-tolerant species increased in both regions, but selective harvest reduced the applicability of functional groups alone to specify winners and losers. Harvest and existing forestry practices supported aspen dominance in mixed forests, although without aspen forestry and with fire suppression, mixed forests will transition to a greater composition of shade-tolerant species, converging to forests similar to broadleaf forests. A functional group framework provided a perspective of winning and losing species and traits, selective filters, and forest ecosystems that can be generalized to other regions, regardless of species identity.

  10. Slow slip events and seismic tremor at circum-Pacific subduction zones

    Science.gov (United States)

    Schwartz, Susan Y.; Rokosky, Juliana M.

    2007-09-01

    It has been known for a long time that slip accompanying earthquakes accounts for only a fraction of plate tectonic displacements. However, only recently has a fuller spectrum of strain release processes, including normal, slow, and silent earthquakes (or slow slip events) and continuous and episodic slip, been observed and generated by numerical simulations of the earthquake cycle. Despite a profusion of observations and modeling studies the physical mechanism of slow slip events remains elusive. The concurrence of seismic tremor with slow slip episodes in Cascadia and southwestern Japan provides insight into the process of slow slip. A perceived similarity between subduction zone and volcanic tremor has led to suggestions that slow slip involves fluid migration on or near the plate interface. Alternatively, evidence is accumulating to support the notion that tremor results from shear failure during slow slip. Global observations of the location, spatial extent, magnitude, duration, slip rate, and periodicity of these aseismic slip transients indicate significant variation that may be exploited to better understand their generation. Most slow slip events occur just downdip of the seismogenic zone, consistent with rate- and state-dependent frictional modeling that requires unstable to stable transitional properties for slow slip generation. At a few convergent margins the occurrence of slow slip events within the seismogenic zone makes it highly likely that transitions in frictional properties exist there and are the loci of slow slip nucleation. Slow slip events perturb the surrounding stress field and may either increase or relieve stress on a fault, bringing it closer to or farther from earthquake failure, respectively. This paper presents a review of slow slip events and related seismic tremor observed at plate boundaries worldwide, with a focus on circum-Pacific subduction zones. Trends in global observations of slow slip events suggest that (1) slow slip is a

  11. Spatial and Temporal Comparisons of Tremor and Slow Slip in Cascadia

    Science.gov (United States)

    Hall, K.; Houston, H.; Schmidt, D. A.

    2015-12-01

    Tremor is often thought to be a proxy for slip during ETS events and has been shown to have a relatively abrupt updip boundary, implying an abrupt updip limit of slip. However, as shown by Houston (AGU abstract, 2012) and Hall and Houston (AGU abstract, 2014), slip inferred from GPS extended updip of the seismically-detected tremor in the 2010 M6.8 and 2012 M6.7 ETS events. If slip extending updip of tremor is a persistent phenomena, tremor cannot be directly used as a proxy for slip. Following the methods used on the 2010 and 2012 ETS event, we found that the August 2009 ETS around Portland, OR also showed slip updip of tremor. Principal Component Analysis was implemented to automatically select the direction and magnitude of the maximum displacement vector. Our Green's functions use the Okada formulation of buried rectangular faults in a halfspace for a grid of 8x8 km subfaults based on the McCrory slab model. We then performed static inversions with 2nd order Tikhonov regularization to find slip on the fault surface. We also compared two different inversions for 2009, one where slip was allowed on a broad regional grid and a tremor-restricted inversion (TRI) where slip was restricted to subfaults in which tremor occurred. We found the 2009 ETS event released the equivalent of a M6.8 in slip. We also found that, as in the previous ETSs, the TRI forced up to 10 cm of slip to the updip edge of the grid, which is exceeds the amount of plate convergence expected in the inter-ETS periods and is therefore physically unsustainable over several ETS events. The excess slip along the updip edge in the TRI models also suggests that the geodetic data prefer slip with a larger footprint than the spatial pattern of tremor, and supports our conclusion that tremor does not represent all of the slip during an ETS event. We see consistent and clear spatial relationship between tremor and slip with some slip occurring updip of tremor. Our static inversions show where slip is

  12. The Balanced Company

    DEFF Research Database (Denmark)

    through control or trust. Human resource specialists need to make balanced decisions about how to design tasks and jobs in order to make them attractive as well as motivating. Marketers need to make balanced decisions about how to market products in the light of what is now important in consumers...... in their environments. Communication specialists need to make balanced decisions which take the different value systems and assumptions of stakeholders into consideration. Change specialists need to balance the need for continuity and change. Managers need to make balanced decisions about whether to achieve goals......' and other stakeholder's eyes. Leaders also have to acknowledge that there are times when organizations have to be taken out of balance, since it is necessary to 'unfreeze' existing relationships in organizations during change. Therefore, there are decision and organizing processes involved in both...

  13. Detailed balance condition and effective free energy in the primitive chain network model

    Science.gov (United States)

    Uneyama, Takashi; Masubuchi, Yuichi

    2011-11-01

    We consider statistical mechanical properties of the primitive chain network (PCN) model for entangled polymers from its dynamic equations. We show that the dynamic equation for the segment number of the PCN model does not reduce to the standard Langevin equation which satisfies the detailed balance condition. We propose heuristic modifications for the PCN dynamic equation for the segment number, to make it reduce to the standard Langevin equation. We analyse some equilibrium statistical properties of the modified PCN model, by using the effective free energy obtained from the modified PCN dynamic equations. The PCN effective free energy can be interpreted as the sum of the ideal Gaussian chain free energy and the repulsive interaction energy between slip-links. By using the single chain approximation, we calculate several distribution functions of the PCN model. The obtained distribution functions are qualitatively different from ones for the simple slip-link model without any direct interactions between slip-links.

  14. Detailed balance condition and effective free energy in the primitive chain network model.

    Science.gov (United States)

    Uneyama, Takashi; Masubuchi, Yuichi

    2011-11-14

    We consider statistical mechanical properties of the primitive chain network (PCN) model for entangled polymers from its dynamic equations. We show that the dynamic equation for the segment number of the PCN model does not reduce to the standard Langevin equation which satisfies the detailed balance condition. We propose heuristic modifications for the PCN dynamic equation for the segment number, to make it reduce to the standard Langevin equation. We analyse some equilibrium statistical properties of the modified PCN model, by using the effective free energy obtained from the modified PCN dynamic equations. The PCN effective free energy can be interpreted as the sum of the ideal Gaussian chain free energy and the repulsive interaction energy between slip-links. By using the single chain approximation, we calculate several distribution functions of the PCN model. The obtained distribution functions are qualitatively different from ones for the simple slip-link model without any direct interactions between slip-links.

  15. Evaporation of Sessile Droplets on Slippery Liquid-Infused Porous Surfaces (SLIPS).

    Science.gov (United States)

    Guan, Jian H; Wells, Gary G; Xu, Ben; McHale, Glen; Wood, David; Martin, James; Stuart-Cole, Simone

    2015-11-03

    Over the past decade, the most common approach to creating liquid shedding surfaces has been to amplify the effects of nonwetting surface chemistry, using micro/nanotexturing to create superhydrophobic and superoleophobic surfaces. Recently, an alternative approach using impregnation of micro/nanotextured surfaces with immiscible lubricating liquids to create slippery liquid-infused porous surfaces (SLIPS) has been developed. These types of surfaces open up new opportunities to study the mechanism of evaporation of sessile droplets in zero contact angle hysteresis situations where the contact line is completely mobile. In this study, we fabricated surfaces consisting of square pillars (10-90 μm) of SU-8 photoresist arranged in square lattice patterns with the center-to-center separation between pillars of 100 μm, on which a hydrophobic coating was deposited and the textures impregnated by a lubricating silicone oil. These surfaces showed generally low sliding angles of 1° or less for small droplets of water. Droplet profiles were more complicated than on nonimpregnated surfaces and displayed a spherical cap shape modified by a wetting ridge close to the contact line due to balancing the interfacial forces at the line of contact between the droplet, the lubricant liquid and air (represented by a Neumann triangle). The wetting ridge leads to the concept of a wetting "skirt" of lubricant around the base of the droplet. For the SLIP surfaces, we found that the evaporation of small sessile droplets (∼2 mm in diameter) followed an ideal constant contact angle mode where the apparent contact angle was defined from the intersection of the substrate profile with the droplet spherical cap profile. A theoretical model based on diffusion controlled evaporation was able to predict a linear dependence in time for the square of the apparent contact radius. The experimental data was in excellent quantitative agreement with the theory and enabled estimates of the diffusion

  16. Balance and flexibility.

    Science.gov (United States)

    2003-12-01

    The 'work-life balance' and flexible working are currently key buzz terms in the NHS. Those looking for more information on these topics should visit Flexibility at www.flexibility.co.uk for a host of resources designed to support new ways of working, including information on flexible workers and flexible rostering, the legal balancing act for work-life balance and home working.

  17. Subgroup Balancing Propensity Score

    OpenAIRE

    DONG, JING; Zhang, Junni L; Li, Fan

    2017-01-01

    We investigate the estimation of subgroup treatment effects with observational data. Existing propensity score matching and weighting methods are mostly developed for estimating overall treatment effect. Although the true propensity score should balance covariates for the subgroup populations, the estimated propensity score may not balance covariates for the subgroup samples. We propose the subgroup balancing propensity score (SBPS) method, which selects, for each subgroup, to use either the ...

  18. Modeling of Slow Slip Events at the Hikurangi Subduction Margin

    Science.gov (United States)

    Williams, C. A.; Wallace, L. M.; Beavan, R. J.; Lohman, R. B.; Ellis, S. M.; Marson-Pidgeon, K.; Eberhart-Phillips, D. M.; Reyners, M.; Henrys, S. A.; Bell, R. E.

    2011-12-01

    Slow slip events (SSEs) occur along nearly the entire Hikurangi subduction margin adjacent to the North Island, New Zealand. Long duration (1-2 years), deep (40- 60 km depth), large events (equivalent to Mw ~7.0) occur at the southern Hikurangi margin, while shallow (10-15 km depth), short (1-2 weeks), smaller events (equivalent to Mw ~6.5) occur at the northern and central Hikurangi margin. A recently-initiated shallow event (Castle Point) lies further to the south than previous shallow events and appears to be rupturing a portion of the plate interface that was previously thought to be locked. Since 2000, three major slow slip events have been identified at the southern Hikurangi margin; the 2003 Kapiti SSE, the 2004/2005 Manawatu SSE, and the 2007/2008 Kapiti SSE (which ended in early 2009). A repeat of the 2004/2005 Manawatu event is presently underway. In some cases, these SSEs may have triggered moderate seismicity within the subducting Pacific plate (e.g., Reyners and Bannister, 2007). To date, all of the inferred slip distributions for the SSEs have been obtained using elastic half-space dislocation models. Numerous recent studies of coseismic displacement fields have shown that variations in elastic properties and surface topography can influence the predicted deformation. In our initial work, we used a finite element model to evaluate the influence of material property variations on the predicted surface deformation field. Elastic properties were assigned based on a seismic velocity model, and slip distributions inferred from an elastic half-space model were applied. When compared to the elastic half- space model, we found that the heterogeneous models generally predict larger amounts of surface deformation, indicating that the half-space models may be overestimating the amount of slip. As the next phase in our study, we are using finite element models that include material property variations and topography to generate Green's functions for use in an

  19. Spacing and strength of active continental strike-slip faults

    Science.gov (United States)

    Zuza, Andrew V.; Yin, An; Lin, Jessica; Sun, Ming

    2017-01-01

    Parallel and evenly-spaced active strike-slip faults occur widely in nature across diverse tectonic settings. Despite their common existence, the fundamental question of what controls fault spacing remains unanswered. Here we present a mechanical model for the generation of parallel strike-slip faults that relates fault spacing to the following parameters: (1) brittle-crust thickness, (2) fault strength, (3) crustal strength, and (4) crustal stress state. Scaled analogue experiments using dry sand, dry crushed walnut shells, and viscous putty were employed to test the key assumptions of our quantitative model. The physical models demonstrate that fault spacing (S) is linearly proportional to brittle-layer thickness (h), both in experiments with only brittle materials and in two-layer trials involving dry sand overlying viscous putty. The S / h slope in the two-layer sand-putty experiments may be controlled by the (1) rheological/geometric properties of the viscous layer, (2) effects of distributed basal loading caused by the viscous shear of the putty layer, and/or (3) frictional interaction at the sand-putty interface (i.e., coupling between the viscous and brittle layers). We tentatively suggest that this third effect exerts the strongest control on fault spacing in the analogue experiments. By applying our quantitative model to crustal-scale strike-slip faults using fault spacing and the seismogenic-zone thickness obtained from high-resolution earthquake-location data, we estimate absolute fault friction of active strike-slip faults in Asia and along the San Andreas fault system in California. We show that the average friction coefficient of strike-slip faults in the India-Asia collisional orogen is lower than that of faults in the San Andreas fault system. Weaker faults explain why deformation penetrates >3500 km into Asia from the Himalaya and why the interior of Asia is prone to large (M > 7.0) devastating earthquakes along major intra-continental strike-slip

  20. Trying to lose weight among non-overweight university students from 22 low, middle and emerging economy countries.

    Science.gov (United States)

    Peltzer, Karl; Pengpid, Supa

    2015-01-01

    The aim of this study was to assess the prevalence of trying to lose weight among non-overweight in university students and its sociodemographic and behavioural factors from 22 low and middle income and emerging economy countries. In a cross-sectional survey we took anthropometric measurements and used a self-administered questionnaire among 15997 undergraduate university students (mean age 20.8, Standard deviation=2.8, age range of 16-30 years) from 22 universities in 22 countries. Body mass index (BMI) was used for weight status. Results indicate that 27.1% non-overweight students were trying to lose weight, 34.6% among women and 16.5% among men. Among underweight or normal weight students, 19.0% perceived themselves to be overweight, 11.3% were dieting to lose weight, and 53.5% considered to lose weight of high importance. Multivariate logistic regression found that being female, coming from a low income country, the perception of being overweight, high importance of losing weight, dieting to lose weight, trying to eat fibre, and avoiding foods with fat and cholesterol were associated with trying to lose weight in non-overweight university students. The study found a high prevalence of weight control practices and several specific risk factors were identified that can be utilized in interventions to target unhealthy weight control measures.

  1. Motion of the Tippe Top : Gyroscopic Balance Condition and Stability

    OpenAIRE

    Ueda, Takahiro(Nikhef Theory Group, Science Park 105, 1098 XG, Amsterdam, The Netherlands); Sasaki, Ken; Watanabe, Shinsuke

    2005-01-01

    We reexamine a very classical problem, the spinning behavior of the tippe top on a horizontal table. The analysis is made for an eccentric sphere version of the tippe top, assuming a modified Coulomb law for the sliding friction, which is a continuous function of the slip velocity $\\vec v_P$ at the point of contact and vanishes at $\\vec v_P=0$. We study the relevance of the gyroscopic balance condition (GBC), which was discovered to hold for a rapidly spinning hard-boiled egg by Moffatt and S...

  2. An Automatic Cycle-Slip Processing Method and Its Precision Analysis

    Institute of Scientific and Technical Information of China (English)

    ZHENG Zuoya; LU Xiushan

    2006-01-01

    On the basis of analyzing and researching the current algorithms of cycle-slip detection and correction, a new method of cycle-slip detection and correction is put forward in this paper, that is, a reasonable cycle-slip detection condition and algorithm with corresponding program COMPRE (COMpass PRE-processing) to detect and correct cycle-slip automatically, compared with GIPSY and GAMIT software, for example, it is proved that this method is effective and credible to cycle-slip detection and correction in GPS data pre-processing.

  3. Numerical study of the effect of Navier slip on the driven cavity flow

    KAUST Repository

    He, Qiaolin

    2009-10-01

    We study the driven cavity flow using the Navier slip boundary condition. Our results have shown that the Navier slip boundary condition removes the corner singularity induced by the no-slip boundary condition. In the low Reynolds number case, the behavior of the tangential stress is examined and the results are compared with the analytic results obtained in [14]. For the high Reynolds number, we study the effect of the slip on the critical Reynolds number for Hopf bifurcation. Our results show that the first Hopf bifurcation critical Reynolds number is increasing with slip length. © 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. A NEW CRITERION FOR OCCURRENCE OF STICK-SLIP MOTION IN DRIVE MECHANISM

    Institute of Scientific and Technical Information of China (English)

    Ding Wenjing; Fan Shichao; Lu Mingwan

    2000-01-01

    This paper, using Karnopp's model of friction force and phase plane method, studies the stick-slip motion of the flexible drive mechanism. It is explained that a sudden drop of friction force is the essential source of stick-slip motion when the sliding is impending. A new criterion for occurrence of stick-slip motion is established.The stick-slip region and the stable region in a parameter plane are separated by a critical parameter curve. Moreover, for the stick-slip motion of the flexible drive mechanism without viscous damping, a parameter expression is obtained. The results may be used in design of the flexible drive mechanism.

  5. Identifying Balance in a Balanced Scorecard System

    Science.gov (United States)

    Aravamudhan, Suhanya; Kamalanabhan, T. J.

    2007-01-01

    In recent years, strategic management concepts seem to be gaining greater attention from the academicians and the practitioner's alike. Balanced Scorecard (BSC) concept is one such management concepts that has spread in worldwide business and consulting communities. The BSC translates mission and vision statements into a comprehensive set of…

  6. Water generation and transport below Europa's strike-slip faults

    Science.gov (United States)

    Kalousová, Klára; Souček, Ondřej; Tobie, Gabriel; Choblet, Gaël.; Čadek, Ondřej

    2016-12-01

    Jupiter's moon Europa has a very young surface with the abundance of unique terrains that indicate recent endogenic activity. Morphological models as well as spectral observations suggest that it might possess shallow lenses of liquid water within its outer ice shell. Here we investigate the generation and possible accumulation of liquid water below the tidally activated strike-slip faults using a numerical model of two-phase ice-water mixture in two-dimensional Cartesian geometry. Our results suggest that generation of shallow partially molten regions underneath Europa's active strike-slip faults is possible, but their lifetime is constrained by the formation of Rayleigh-Taylor instabilities due to the negative buoyancy of the melt. Once formed, typically within a few million years, these instabilities efficiently transport the meltwater through the shell. Consequently, the maximum water content in the partially molten regions never exceeds 10% which challenges their possible detection by future exploration mission.

  7. Slip-stick excitation and travelling waves excite silo honking

    Science.gov (United States)

    Vriend, Nathalie; Warburton, Kasia; Porte, Elze

    2016-11-01

    Industrial storage silos filled with PET-particles can create a sound upon discharge. The sound forms a nuisance for the environment when the structure starts to act as a loudspeaker and may ultimately result in structural failure. This work investigates the phenomenon experimentally-the deployment of a microphone, an accelerometer and high-speed imaging on a laboratory set-up reveal the driving mechanism for the structural resonance: stick-slip at the wall. Particle image velocimetry shows an asymmetric, upwards travelling wave (at 50 m/s) which contains the dynamic "slip"-region. The frequency of the mechanical motion of the grains is successfully correlated to the frequency of the emitted sound. Friction models are explored to describe and quantify the frictional interaction between the grains and the wall.

  8. FABRICATION OF FINE GRAINED DENSE HAP THROUGH SLIP CASTING ROUTE

    Directory of Open Access Journals (Sweden)

    HOWA BEGAM

    2011-02-01

    Full Text Available The purpose of this study is to synthesize nano-grained Calcium Hydroxyapatite (HAp through slip casting technique. For this, hydroxyapatite powders were synthesized using two methods, wet chemical method and Ammoniacal method. The as-prepared powders and calcined powders were characterized using XRD, FTIR, to study the phases of the powders. The hydroxyapatite powder calcined at 1000°C for 2hr was used to prepare 50 vol% slurry using DN40 (sodium olyacrylate as dispersing agent. After slip casting, the green bodies were sintered at different temperatures, 1100, 1200, 1250 and 1300°C with 2hr soaking time. The sintered dense samples were characterized for physical and mechanical behavior.Dense HaP samples were obtained at 1250C.

  9. Soft matter dynamics: Accelerated fluid squeeze-out during slip

    Science.gov (United States)

    Hutt, W.; Persson, B. N. J.

    2016-03-01

    Using a Leonardo da Vinci experimental setup (constant driving force), we study the dependency of lubricated rubber friction on the time of stationary contact and on the sliding distance. We slide rectangular rubber blocks on smooth polymer surfaces lubricated by glycerol or by a grease. We observe a remarkable effect: during stationary contact the lubricant is only very slowly removed from the rubber-polymer interface, while during slip it is very rapidly removed resulting (for the grease lubricated surface) in complete stop of motion after a short time period, corresponding to a slip distance typically of order only a few times the length of the rubber block in the sliding direction. For an elastically stiff material, poly(methyl methacrylate), we observe the opposite effect: the sliding speed increases with time (acceleration), and the lubricant film thickness appears to increase. We propose an explanation for the observed effect based on transient elastohydrodynamics, which may be relevant also for other soft contacts.

  10. Cytoplasmic streaming in plant cells: the role of wall slip.

    Science.gov (United States)

    Wolff, K; Marenduzzo, D; Cates, M E

    2012-06-01

    We present a computer simulation study, via lattice Boltzmann simulations, of a microscopic model for cytoplasmic streaming in algal cells such as those of Chara corallina. We modelled myosin motors tracking along actin lanes as spheres undergoing directed motion along fixed lines. The sphere dimension takes into account the fact that motors drag vesicles or other organelles, and, unlike previous work, we model the boundary close to which the motors move as walls with a finite slip layer. By using realistic parameter values for actin lane and myosin density, as well as for endoplasmic and vacuole viscosity and the slip layer close to the wall, we find that this simplified view, which does not rely on any coupling between motors, cytoplasm and vacuole other than that provided by viscous Stokes flow, is enough to account for the observed magnitude of streaming velocities in intracellular fluid in living plant cells.

  11. Slipped capital femoral epiphysis caused by neurogenic heterotopic ossification.

    Science.gov (United States)

    Chang, Sam Yeol; Yoo, Won Joon; Park, Moon Seok; Chung, Chin Youb; Choi, In Ho; Cho, Tae-Joon

    2013-11-01

    Slipped capital femoral epiphysis (SCFE) is rare in nonambulatory patients, as mechanical factors play important roles in the development of the disease. We report a case of SCFE, which occurred in a 12-year-old girl with a nonambulatory status after cerebral infarction. SCFE occurred after she received passive range of motion exercise and extracorporeal shock wave treatment for neurogenic heterotopic ossification around the hip joint. The patient was successfully managed by a stepwise approach, with radiological and clinical improvements.

  12. Implications of Fault Curvature for Slip Distributions, Opening, and Damage

    Science.gov (United States)

    Ritz, E.; Pollard, D. D.; Griffith, W. A.

    2010-12-01

    In his seminal 1905 paper on the dynamics of faulting, E.M. Anderson idealized faults as planar structures. Although the theory of fault mechanics has developed from this idealization, abundant evidence from geological and geophysical investigations shows that fault surfaces exhibit geometric irregularities on many scales. Understanding the mechanical behavior of non-planar fault surfaces is a fundamental problem for scientists working on the brittle deformation of Earth’s crust and is of practical importance to disciplines such as rock mechanics, geotechnical engineering, and earthquake science. Geologic observations of exhumed meter-scale strike-slip faults in the Bear Creek drainage, Sierra Nevada, CA, provide insights into the relationship between non-planar fault geometry and frictional slip at depth. These faults have smoothly curving surface expressions which may be approximated as sinusoidal curves. We numerically investigate both the natural fault geometries and model sinusoidal faults. Earlier models for the stress and deformation near a sinusoidal fault assume boundary conditions and fault characteristics that are not observed in nature. The 2D displacement discontinuity boundary element method is combined with a complementarity algorithm to model quasi-static slip on non-planar faults, and the resulting deformation of the nearby rock. This numerical technique can provide an accurate solution for any boundary value problem regarding crack-like features in an otherwise homogeneous and isotropic elastic material. Both field and numerical investigations indicate that non-planar fault geometry perturbs the along-fault slip form the distribution predicted for planar faults. In addition, both field observations and numerical modeling show that sliding along curved faults at depth may lead to localized fault opening, affecting local permeability and fluid migration.

  13. Weakly nonlinear stability of ultra-thin slipping films

    Institute of Scientific and Technical Information of China (English)

    HU Guohui

    2005-01-01

    A weakly nonlinear theory is presented to study the effects of slippage on the stability of the ultra-thin polymer films.The nonlinear mathematical model is constructed for perturbations of small finite amplitude based on hydrodynamic equations with the long wave approximation. Results reveal that the nonlinearity always accelerates the rupture of the films. The influences of the slip length, film thickness, and initial amplitude of perturbations on the rupture of the films are investigated.

  14. Keeping Your Balance

    Science.gov (United States)

    ... News & Events Press Releases NOF in the News Osteoporosis in the News Press/Media Kit NOF Events Blog Advocacy NOF Store Shopping Cart Home › Patients › Fractures/Fall Prevention › Exercise/Safe Movement › Keeping Your Balance Keeping Your Balance ...

  15. Conclusion: The balanced company

    DEFF Research Database (Denmark)

    2013-01-01

    This concluding chapter brings together the various research findings of the book "The balanced company - organizing for the 21st Century" and develops a general overview of their implications for our understanding of the balancing processes unfolding in companies and organizations....

  16. Leadership: A Balancing Act

    Science.gov (United States)

    Hines, Thomas E.

    2011-01-01

    Maintaining balance in leadership can be difficult because balance is affected by the personality, strengths, and attitudes of the leader as well as the complicated environment within and outside the community college itself. This article explores what being a leader at the community college means, what the threats are to effective leadership, and…

  17. A smartphone inertial balance

    Science.gov (United States)

    Barrera-Garrido, Azael

    2017-04-01

    In order to measure the mass of an object in the absence of gravity, one useful tool for many decades has been the inertial balance. One of the simplest forms of inertial balance is made by two mass holders or pans joined together with two stiff metal plates, which act as springs.

  18. Research Development and Perspective on Slow Slip, Tremors, and Slow Earthquakes

    Institute of Scientific and Technical Information of China (English)

    Wang Yanzhao; Shen Zhengkang

    2007-01-01

    Seismological and geodetic observations indicate that slow slip sometimes occurs in active fault zones beneath the seismogenic depth, and large slow slip can result in transient ground motion.Slow earthquakes, on the other hand, emit tremor-like signals within a narrow frequency band, and usually produce no catastrophic consequences. In general, slow slip and slow earthquakes probably correspond to deformation processes associated with releasing elastic energy in fault zones, and understanding their mechanisms may help improve our understanding of fault zone dynamic processes. This article reviews the research progress on slow slip and slow earthquakes over the last decade. Crustal motion and tremor activities associated with slow slip and slow earthquakes have been investigated extensively, mainly involving locating sources of slow slip and slow earthquakes and numerical modeling of their processes. In the meantime, debates have continued about slow slip and slow earthquakes,such as their origins, relationship, and mechanisms.

  19. Hydrodynamics beyond Navier-Stokes: the slip flow model.

    Science.gov (United States)

    Yudistiawan, Wahyu P; Ansumali, Santosh; Karlin, Iliya V

    2008-07-01

    Recently, analytical solutions for the nonlinear Couette flow demonstrated the relevance of the lattice Boltzmann (LB) models to hydrodynamics beyond the continuum limit [S. Ansumali, Phys. Rev. Lett. 98, 124502 (2007)]. In this paper, we present a systematic study of the simplest LB kinetic equation-the nine-bit model in two dimensions--in order to quantify it as a slip flow approximation. Details of the aforementioned analytical solution are presented, and results are extended to include a general shear- and force-driven unidirectional flow in confined geometry. Exact solutions for the velocity, as well as for pertinent higher-order moments of the distribution functions, are obtained in both Couette and Poiseuille steady-state flows for all values of rarefaction parameter (Knudsen number). Results are compared with the slip flow solution by Cercignani, and a good quantitative agreement is found for both flow situations. Thus, the standard nine-bit LB model is characterized as a valid and self-consistent slip flow model for simulations beyond the Navier-Stokes approximation.

  20. Enhanced Dynamical Stability with Harmonic Slip-stacking

    CERN Document Server

    Eldred, Jeffrey

    2016-01-01

    We develop a configuration of radio-frequency (rf) cavities to dramatically improve the performance of slip-stacking. Slip-stacking is an accumulation technique used at Fermilab to nearly double proton intensity by maintaining two beams of different momenta in the same storage ring. The two particle beams are longitudinally focused in the Recycler by two 53 MHz 100 kV rf cavities with a small frequency difference between them. We propose an additional 106 MHz 20 kV rf cavity with a frequency at the double the average of the upper and lower main rf frequencies. We show the harmonic rf cavity cancels out the resonances generated between the two main rf cavities and we derive the relationship between the harmonic rf voltage and the main rf voltage. We find the area factors that can be used to calculate the available phase space area for any set of beam parameters without individual simulation. We establish Booster beam quality requirements to achieve 99\\% slip-stacking efficiency. We measure the longitudinal dis...

  1. Surface Slip Gradients and Fault Connectivity at Depth

    Science.gov (United States)

    Oglesby, D. D.

    2012-12-01

    Observational and numerical evidence has implied that it is difficult for earthquake rupture to jump stepovers with widths significantly larger than 4 km [e.g., Harris et al., 1991; Harris and Day, 1999; Wesnousky, 2006]. It has also been shown observationally that if surface slip tapers to zero over a small along-strike distance on the primary fault segment at a stepover, an earthquake has a significantly increased likelihood of jumping the stepover and propagating to a secondary fault segment [Elliott et al., 2009]. This latter result has been attributed to a high slip gradient on the primary segment generating a strong dynamic stress concentration on the second segment, which can facilitate rupture renucleation [Oglesby, 2008]. Recent 3D dynamic earthquake simulations, however, provide an alternative interpretation for this effect: an earthquake on a fault that is disconnected at the surface but is connected (i.e., is a throughgoing structure) at depth also will tend to produce a higher surface slip gradient at the edges of the segments than will a system that is fully disconnected, at least for relatively long segments that are connected at relatively shallow depth. This result raises the possibility that many of the rupture "jumps" that we see at fault stepovers on the surface may in fact reflect through-going ruptures on a continuous subsurface fault. These results may have implications for the pervasiveness of fault connectivity at depth, the likelihood of throughgoing rupture at surface stepovers, ground motion estimates, and seismic hazard.

  2. Slip Flow in Elliptic Microducts with Constant Heat Flux

    Directory of Open Access Journals (Sweden)

    Marco Spiga

    2012-01-01

    Full Text Available This paper outlines a numerical model for determining the dynamic and thermal performances of a rarefied fluid flowing in a microduct with elliptical cross-section. A slip flow is considered, in laminar steady state condition, in fully developed forced convection, with Knudsen number in the range 0.001−0.1, in H1 boundary conditions. The velocity and temperature distributions are determined in the elliptic cross-section, for different values of both aspect ratio γ and Knudsen number, resorting to the Comsol Multiphysics software, to solve the momentum and energy equations. The friction factors (or Poiseuille numbers and the convective heat transfer coefficients (or Nusselt numbers are calculated and presented in graphs and tables. The numerical solution is validated resorting to data available in literature for continuum flow in elliptic cross-sections (Kn = 0 and for slip flow in circular ducts (γ=1. A further benchmark is carried out for the velocity profile for slip flow in ellipticalcross-sections, thanks to a recent analytical solution obtained using elliptic cylinder coordinates and the separation of variables method. The Poiseuille and Nusselt numbers for elliptic cross-sections are discussed. The results may be used to predict pressure drop and heat transfer performance in metallic microducts with elliptic cross-section, produced by microfabrication for microelectromechanical systems (MEMS.

  3. Onset of aseismic creep on major strike-slip faults

    KAUST Repository

    Çakir, Ziyadin

    2012-10-02

    Time series analysis of spaceborne synthetic aperture radar (SAR) data, GPS measurements, and fi eld observations reveal that the central section of the Izmit (Turkey) fault that slipped with a supershear rupture velocity in the A.D. 1999, Mw7.4, Izmit earthquake began creeping aseismically following the earthquake. Rapid initial postseismic afterslip decayed logarithmically with time and appears to have reached a steady rate comparable to the preearthquake full fault-crossing rate, suggesting that it may continue for decades and possibly until late in the earthquake cycle. If confi rmed by future monitoring, these observations identify postseismic afterslip as a mechanism for initiating creep behavior along strike-slip faults. Long-term afterslip and/or creep has signifi cant implications for earthquake cycle models, recurrence intervals of large earthquakes, and accordingly, seismic hazard estimation along mature strike-slip faults, in particular for Istanbul which is believed to lie adjacent to a seismic gap along the North Anatolian fault in the Sea of Marmara. © 2012 Geological Society of America.

  4. Residual hip growth after pinning of slipped capital femoral epiphysis.

    Science.gov (United States)

    Breaud, Jean; Rubio, Amandine; Leroux, Julien; Griffet, Jacques

    2009-01-01

    Screwing of slipped capital femoral epiphysis must prevent its further slipping by prematurely fusing the physis. Whichever material is used, persistent femoral growth has been described, thereby increasing the risk of bone deformation. The objective of this study is to evaluate the residual growth after screwing of slipped capital femoral epiphysis. This study concerned 26 children, among which 13 children have been included, and 13 children excluded because of an incomplete clinical or radiological follow-up, or treatment by another technique. The pathological hip was treated with one screw (in eight cases) or two screws (in five cases). The controlateral hip was fixed with one screw. The different measures were taken on anteroposterior radiographs done the days after surgery, and on the first radiograph on which the growth plate had fused. Growth plate fusion was obtained after an average of 20 months. Each patient had presented a residual growth of at least one hip, thus 85% of the 26 fixed screws. Among the four hips, which did not grow, three were pathological, and were fixed by one screw (in one case) or two screws (in two cases), in a central or medial position. There was not any statistical relationship between the growth persistence and the other studied criteria. These results, proving the growth persistency, suggest that the follow-up must be extremely careful, as the number of threads crossing the growth plate will decrease, with the risk of loss of mechanical stability and reappearance of the femoral epiphysis slippage.

  5. Water slip flow in superhydrophobic microtubes within laminar flow region

    Institute of Scientific and Technical Information of China (English)

    Zhijia Yu; Xinghua Liu; Guozhu Kuang

    2015-01-01

    The fabrication of superhydrophobic surfaces and the studies on water flow characteristics therein are of great significance to many industrial areas as wel as to science and technology development. Experiments were car-ried out to investigate slip characteristics of water flowing in circular superhydrophobic microtubes within lam-inar flow region. The superhydrophobic microtubes of stainless steel were fabricated with chemical etching–fluorination treatment. An experimental setup was designed to measure the pressure drop as function of water flow rate. For comparison, superhydrophilic tubes were also tested. Poiseuille number Po was found to be smaller for the superhydrophobic microtubes than that for superhydrophilic ones. The pressure drop reduc-tion ranges from 8%to 31%. It decreases with increasing Reynolds number when Re b 900, owing to the transition from Cassie state to Wenzel state. However, it is almost unchanged with further increasing Re after Re N 900. The slip length in superhydrophobic microtubes also exhibits a Reynolds number dependence similarly to the pressure drop reduction. The relation between slip length and Darcy friction factor is theoretically analyzed with consideration of surface roughness effect, which was testified with the experimental results.

  6. Stick-slip advance of the Kohat Plateau in Pakistan

    Science.gov (United States)

    Satyabala, S. P.; Yang, Zhaohui; Bilham, Roger

    2012-02-01

    Throughout most of the Himalaya, slip of the Indian Plate is restrained by friction on the interface between the plate and the overlying wedge of Himalayan rocks. Every few hundred years, this interface--or décollement--ruptures in one or more Mw >=8 earthquakes. In contrast, in the westernmost Himalaya, the Indian Plate slips aseismically beneath wide plateaux fronting the Kohistan Mountains. The plateaux are underlain by viscous décollements that are unable to sustain large earthquakes. Potwar, the widest of these plateaux is underlain by viscous salt, which currently permits it to slide at rates of about 3mmyr-1 (refs , ), much slower than its 2 Myr average. This deceleration has been attributed to recently increased friction through the loss of salt from its décollement. Here we use interferometric synthetic aperture radar and seismic data to assess movement of the Kohat Plateau--the narrowest and thickest plateau. We find that in 1992 an 80 km2 patch of the décollement ruptured in a rare Mw 6.0 earthquake, suggesting that parts of the décollement are locally grounded. We conclude that this hybrid seismic and aseismic behaviour represents an evolution of the mode of slip of the plateaux from steady creep towards increasingly widespread seismic rupture.

  7. Balancing Trust and Control

    DEFF Research Database (Denmark)

    Jagd, Søren

    This paper focuses on the leadership challenge of balancing trust and control. The relation between trust and control has for a long time been a puzzling issue for management researchers. In the paper I first show that there has been a dramatic change in the way the relation between trust...... and control has been conceptualized in trust research. While the relation between trust and control earlier was conceptualized as a more or less stable balance between trust and control, more recent research conceptualizes the relation between trust and control more as a dynamical process that involves...... an ongoing process of balancing the relation between trust and control. Second, taking the departure in the recent conceptualization of the balance between trust and control as an interactive process I discuss the challenges for management in handling this more subtle balancing of trust and control...

  8. Surface slip associated with the 2004 Parkfield, California, earthquake measured on alinement arrays

    Science.gov (United States)

    Lienkaemper, J.J.; Baker, B.; McFarland, F.S.

    2006-01-01

    Although still continuing, surface slip from the 2004 Parkfield earth-quake as measured on alinement arrays appears to be approaching about 30-35 cm between Parkfield and Gold Hill. This includes slip along the main trace and the Southwest Fracture Zone (SWFZ). Slip here was higher in 1966 at about 40 cm. The distribution of 2004 slip appears to have a shape similar to that of the 1966 event, but final slip is expected to be lower in 2004 by about 3-15 cm, even when continuing slip is accounted for. Proportionately, this difference is most notable at the south end at Highway 46, where the 1966 event slip was 13 cm compared to the 2004 slip of 4 cm. Continuous Global Positioning System and creepmeters suggest that significant surface coseismic slip apparently occurred mainly on the SWFZ and perhaps on Middle Mountain (the latter possibly caused by shaking) (Langbein et al., 2005). Creepmeters indicate only minor (<0.2 cm) surface coseismic slip occurred on the main trace between Parkfield and Gold Hill. We infer that 3-6 cm slip accumulated across our arrays in the first 24 hr. At Highway 46, slip appears complete, whereas the remaining sites are expected to take 2-6 years to reach their background creep rates. Following the 1966 event, afterslip at one site persisted as much as 5-10 years. The much longer recurrence intervals between the past two Parkfield earthquakes and the decreasing slip per event may suggest that larger slip deficits are now growing along the Parkfield segment.

  9. Episodic tremor and slip in Northern Sumatra subduction zone

    Science.gov (United States)

    Sianipar, Dimas; Subakti, Hendri

    2017-07-01

    The first reported observation of non-volcanic tremor in Sunda Arc in Sumbawa, Indonesia open a possibility of discovery of episodic tremor and slip (ETS) from out of Pacific Rim. Non-volcanic tremor gives some important information about dynamic of plate boundaries. The characteristics of these tremors are visually as non-impulsive, high frequency, long-duration and low-amplitude signals. Tectonic tremor occurred in a transition part of brittle-ductile of a fault and frequently associated with the shearing mechanism of slow slip. Tectonic tremor is a seismic case that also very interested, because it shows strong sensitivity to stress changes. Deep non-volcanic tremor is usually associated with episodic slow-slip events. Tectonic tremor is found in close association with geodetically observed slow-slip events (SSE) in subduction zones. One research found that there is possibility of SSE occurrence on Banyak Islands, North Sumatra revealed from coral observation. The SSE occurred on the Banyak Islands portion of the megathrust at 30-55 km depth, within the downdip transition zone. We do a systematic search of episodic tremor and its possible relationship with slow-slip phenomena in Northern Sumatra subduction zone. The spectrogram analysis is done to analyze the potential tremor signals. We use three component broadband seismic stations with 20, 25, and 50 sampling per second (BH* and SH* channels). We apply a butterworth 5 Hz highpass filter to separate the signal as local tremor and teleseismic/regional earthquakes. Before computing spectrogram to avoid high-frequency artifacts to remote triggering, we apply a 0.5 Hz filter. We also convert the binary seismic data into sound waves to make sure that these events meet the tectonic tremor criterion. We successfully examine 3 seismic stations with good recording i.e. GSI, SNSI and KCSI. We find there are many evidences of high frequency episodic tremor like signals. This include an analysis of potential triggered

  10. The Slumgullion Natural Laboratory for Observing Slip Phenomena

    Science.gov (United States)

    Gomberg, J. S.; Schulz, W. H.; Bodin, P.; Kean, J. W.; Wang, G.; Coe, J. A.; MacQueen, P.; Foster, K.; Creager, K.

    2009-12-01

    Many natural systems release stresses by failure and sliding across surfaces; examples include landslides, glaciers, crustal- and plate-scale faults. Observational advances continue to reveal diversity in the seismic signals associated with fault slip and how such stress relaxation can occur, even on a single fault system. A particularly rich example are the episodes of slow fault slip near major subduction and transform plate boundaries that manifest as geodetically observed aseismic deformation abetted by a family of seismic signals depleted in high-frequencies relative to those from earthquakes (named ‘episodic tremor and slip’ or ETS). While the driving forces and scales differ, there are striking parallels between some observations and models of ETS and of landslide behaviors; e.g. in both, postulated key controls include rate-dependent friction and strength modulated by pore-pressure changes, dilatancy during rapid shear, and subsequent consolidation. To explore common features and the underlying processes we are studying the Slumgullion landslide, an ideal natural laboratory for observing fault slip and associated seismic and aseismic phenomena. Unlike crustal- or plate-scale studies significant deformation can be measured within a single field season, because the Slumgullion moves at average rates of cm/day. Moreover, pore pressures, displacements, material properties, and environmental variables may be measured directly and continuously at several locations on the landslide (albeit not at the basal sliding surface). We have just completed a field experiment on the Slumgullion to test several hypotheses, particularly that slip along the basal surface and side-bounding faults occurs with comparable richness of aseismic and seismic modes as crustal- and plate-scale boundaries. To do so from August 18-26, 2009 we continuously monitored the displacement-field using a robotic electronic displacement meter and the seismic radiation with 88 vertical

  11. Perspective: border security in the age of globalization: how can we protect ourselves without losing the benefits of openness?

    OpenAIRE

    Peter Andreas

    2003-01-01

    Border security has become increasingly important since 9-11. Yet the benefits of globalization depend on moving people and goods across national boundaries. How can we improve border security without losing the benefits of openness?

  12. From Losing to Loss: Exploring the Expressive Capacities of Videogames Beyond Death as Failure

    Directory of Open Access Journals (Sweden)

    Sabine Harrer

    2013-12-01

    Full Text Available In games, loss is as ubiquitous as it is trivial. One reason for this has been found in the established convention of on-screen character death as a signifier for failure (Klastrup 2006; Grant 2011; Johnson 2011. If that’s all that games have to offer in terms of addressing an existential trope of human experience, the worried protectionist concludes, shouldn’t we dismiss this intrinsically flat medium as inferior to more established media forms such as film or literature? (Ebert 2010. Contrary to this view, this paper discusses gameplay examples that shed light on how this medium might leverage its expressive resources to arrive at rich representations of loss. First, the notion of loss implied in Sigmund Freud’s work “Mourning and Melancholia” (1917 will be discussed in relation to losing in games. Looking at procedurality, fictional alignment and experiential metaphor as three expressive gameplay devices identified by Doris Rusch (2009 will help explain the expressive shortcoming of losing and lay out what is at stake with profound gameplay expression. Moreover, it will serve as the keywords structuring the following analysis of three videogames, Final Fantasy VII (1997, Ico (2001 and Passage (2007, and their design decisions fostering deep representations of loss. Keeping the Freudian notion of loss in mind, we can trace its repercussions on the three expressive dimensions respectively. Following a separate analysis of each gameplay example, the last section will discuss some commonalities and differences and arrive at the identification of desired object, permanent disruption and linearity as design aspects modeling loss in more compelling ways than losing.

  13. Extreme multi-millennial slip rate variations on the Garlock fault, California: geomorphology and geochronology of slip rate constraints

    Science.gov (United States)

    Rhodes, Edward; Dolan, James; McGill, Sally; McAuliffe, Lee; Zinke, Robert

    2016-04-01

    Combining existing paleoseismology with new geomorphic constraints for the same part of the Central Garlock fault in California, USA, allows us to demonstrate pronounced variations in slip rate during the Holocene for this left-lateral strike-slip system. Our results have basic implications for understanding how faults store and release strain energy in large earthquakes, and for Probabilistic Seismic Hazard Assessment (PSHA). A series of well-preserved fluvial terraces within alluvial fans provide offset markers, and newly developed single grain K-feldspar IRSL dating allows us to constrain depositional ages and subsequent erosion of terrace risers with good precision, using multiple samples from several different locations. This new dating approach has wide applicability for paleoseismology and slip rate studies, besides understanding environmental response to climatic events; agreement with independent age control provided by C-14 and Be-10 profiles comes from sites in the USA, Mexico, Tibet and Mongolia. Sediments dominated by a range of grain sizes from silt to boulders can be dated, and the technique is often applicable in locations where quartz OSL does not work well. We examine the interplay and coupling between climate and tectonics at millennial timescales, along with sedimentary and geomorphic responses, and consider how our understanding of fault dynamics can be improved with the benefit of these new approaches.

  14. Extreme multi-millennial slip rate variations on the Garlock fault, California: Strain super-cycles, potentially time-variable fault strength, and implications for system-level earthquake occurrence

    Science.gov (United States)

    Dolan, James F.; McAuliffe, Lee J.; Rhodes, Edward J.; McGill, Sally F.; Zinke, Robert

    2016-07-01

    Pronounced variations in fault slip rate revealed by new measurements along the Garlock fault have basic implications for understanding how faults store and release strain energy in large earthquakes. Specifically, dating of a series of 26.0+3.5/-2.5 m fault offsets with a newly developed infrared-stimulated luminescence method shows that the fault was slipping at >14.0+2.2/-1.8 mm /yr, approximately twice as fast as the long-term average rate, during a previously documented cluster of four earthquakes 0.5-2.0 ka. This elevated late Holocene rate must be balanced by periods of slow or no slip such as that during the ca. 3300-yr-long seismic lull preceding the cluster. Moreover, whereas a comparison of paleoseismic data and stress modeling results suggests that individual Garlock earthquakes may be triggered by periods of rapid San Andreas fault slip or very large-slip events, the ;on-off; behavior of the Garlock suggests a longer-term mechanism that may involve changes in the rate of elastic strain accumulation on the fault over millennial time scales. This inference is consistent with most models of the geodetic velocity field, which yield slip-deficit rates that are much slower than the average latest Pleistocene-early Holocene (post-8-13 ka) Garlock slip rate of 6.5 ± 1.5 mm /yr. These observations indicate the occurrence of millennia-long strain ;super-cycles; on the Garlock fault that may be associated with temporal changes in elastic strain accumulation rate, which may in turn be controlled by variations in relative strength of the various faults in the Garlock-San Andreas-Eastern California Shear Zone fault system and/or changes in relative plate motion rates.

  15. Protein-losing nephropathy associated with Borrelia burgdorferi seropositivity in a soft-coated wheaten terrier: response to therapy.

    Science.gov (United States)

    Horney, Barbara S; Stojanovic, Vladimir

    2013-04-01

    A soft-coated wheaten terrier was examined for lameness with subsequent identification of protein-losing nephropathy, hypoalbuminemia, hyperglobulinemia, and seroconversion to Borrelia burgdorferi. Following doxycycline therapy, the urine protein loss decreased significantly and serum albumin concentration remained close to or within the reference interval for over 3 years, contrary to the reported poor prognosis for renal disease associated with B. burgdorferi or protein-losing nephropathy of soft-coated wheaten terriers.

  16. Late post liver transplant protein losing enteropathy: Rare complication of incisional hernia

    Science.gov (United States)

    Evans, Jonathan D; Perera, M Thamara PR; Pal, CY; Neuberger, James; Mirza, Darius F

    2013-01-01

    Development of oedema and hypoproteinaemia in a liver transplant recipient may be the first signs of graft dysfunction and should prompt a full assessment. We report the novel case of a patient who, years after liver transplantation developed a functional blind loop in an incisional hernia, which manifested as oedema and hypoproteinaemia secondary to protein losing enteropathy. After numerous investigations, the diagnosis was made by flurodeoxyglucose positron emmision tomography (FDG-PET) imaging. Surgical repair of the incisional hernia was followed several months later by resolution of the protein loss, and confirmed at a post operative FDG-PET scan at one year. PMID:23885154

  17. A unique case of collagenous colitis presenting as protein-losing enteropathy successfully treated with prednisolone

    Institute of Scientific and Technical Information of China (English)

    Soichi Sano; Katsunobu Yoshioka; Keiko Yamagami; Ayako Tanaka; Minako Nishio; Tomoyuki Nakamura; Yuki Kubo; Takeshi Inoue; Wataru Ueda; Kiyotaka Okawa

    2008-01-01

    A 76-year-old woman with a 5-mo history of recurrent diarrhea and generalized edema was admitted to our hospital. Colonoscopy revealed edematous mucosa, and histopathological examination was compatible with collagenous colitis. Protein leakage from the colon, particularly in the ascending portion, was identified on 99mTc-human serum albumin scintigraphy. Collagenous colitis associated with protein-losing enteropathy (PLE) without small bowel disease was diagnosed. Prednisolone treatment ameliorated diarrhea and hypoproteinemia. Collagenous colitis should be included in the differential diagnosis of chronic diarrhea with hypoproteinemia for appropriate management.

  18. Load Balancing Scientific Applications

    Energy Technology Data Exchange (ETDEWEB)

    Pearce, Olga Tkachyshyn [Texas A & M Univ., College Station, TX (United States)

    2014-12-01

    The largest supercomputers have millions of independent processors, and concurrency levels are rapidly increasing. For ideal efficiency, developers of the simulations that run on these machines must ensure that computational work is evenly balanced among processors. Assigning work evenly is challenging because many large modern parallel codes simulate behavior of physical systems that evolve over time, and their workloads change over time. Furthermore, the cost of imbalanced load increases with scale because most large-scale scientific simulations today use a Single Program Multiple Data (SPMD) parallel programming model, and an increasing number of processors will wait for the slowest one at the synchronization points. To address load imbalance, many large-scale parallel applications use dynamic load balance algorithms to redistribute work evenly. The research objective of this dissertation is to develop methods to decide when and how to load balance the application, and to balance it effectively and affordably. We measure and evaluate the computational load of the application, and develop strategies to decide when and how to correct the imbalance. Depending on the simulation, a fast, local load balance algorithm may be suitable, or a more sophisticated and expensive algorithm may be required. We developed a model for comparison of load balance algorithms for a specific state of the simulation that enables the selection of a balancing algorithm that will minimize overall runtime.

  19. Coupled Flow and Geomechanics Modeling of Slow Earthquakes: Application to Slow Slip Events (SSE) in the Guerrero Gap, Mexico

    Science.gov (United States)

    Alves da Silva Junior, J.; Frank, W.; Castineira, D.; Jha, B.; Juanes, R.

    2016-12-01

    Three major cycles of slow slip events (SSE) have been reported since the early 2000s in the Guerrero gap, Mexico, on the boundary between the Cocos and North American plates. Analysis of teleseismic waveforms recorded on a dense temporary seismic network in the Guerrero gap have found low S-wave velocity and high Vp/Vs ratios at the depths corresponding to the sources of SSE, implying the possible presence of fluids and thus an active dewatering process that may result in near-lithostatic pore pressure at the plate interface. Here we use coupled flow and geomechanics analysis of the Guerrero gap to model transient changes in the stress field in the subduction zone as a result of pore pressure fluctuations and potential fluid flow along the subduction interface. Our computational modeling approach couples a multiphase flow simulator with a mechanical simulator using the unconditionally stable fixed stress scheme for the sequential solution of the two-way coupling between flow and geomechanics (Jha and Juanes, 2014). We assume quasi-static mechanical deformation and neglect the inertial term in the solid momentum balance equation—an approximation that is valid to model SSE assuming aseismic slip. We represent the subducting Cocos fault as a surface embedded in a three-dimensional medium, and use zero thickness interface elements to accurately model stick-slip behavior under dynamically evolving fluid pressure and fault strength. We employ the rate- and state-dependent friction model in the evolution of the coefficient of friction. We calibrate our model using two distinct datasets—GPS data and tremor catalogs in the area of Guerrero gap—and by separately constraining the rate of water production from a model of mineral hydration with depth. Our quantitative modeling approach furnishes a mechanistic understanding of the relationship between pore pressure evolution, stress transfer and tremor migration, and helps elucidate the origin of SSE in this area.

  20. Neural mechanisms underlying balance control in Tai Chi.

    Science.gov (United States)

    Gatts, Strawberry

    2008-01-01

    The efficacy of Tai Chi (TC) to improve neuromuscular response characteristics underlying dynamic balance recovery in balance-impaired seniors at high risk for falling was examined during perturbed walking. Twenty-two subjects were randomized into TC or control groups. Nineteen subjects (68-92 years, BERG 44 or less) completed the study. TC training incorporated repetitive exercises using TC's essential motor/biomechanical strategies, techniques, and postural components. Control training used axial exercises, balance awareness/education and stress reduction. Groups trained 1.5 h/day, 5 days/week for 3 weeks. After post-testing, controls received TC training. Subjects walked across a force plate triggered to move forward 15 cm at 40 cm/s at heelstrike. Tibialis anterior and medial gastrocnemius responses during balance recovery were recorded from electromyograms. Four clinical measures of balance were also examined. TC subjects, but not controls, significantly reduced tibialis anterior response time from 148.92 +/- 45.11 ms to 98.67 +/- 17.22 ms (p < or = 0.004) and decreased co-contraction of antagonist muscles (p < or = 0.003) of the perturbed leg. All clinical balance measures significantly improved after TC. TC training transferred to improved neuromuscular responses controlling the ankle joint during perturbed gait in balance-impaired seniors who had surgical interventions to their back, hips, knees and arthritis. The fast, accurate neuromuscular activation crucial for efficacious response to slips also transferred to four clinical measures of functional balance. Significant enhancement was achieved with 3 weeks of training.

  1. Consideration of Dynamical Balances

    Science.gov (United States)

    Errico, Ronald M.

    2015-01-01

    The quasi-balance of extra-tropical tropospheric dynamics is a fundamental aspect of nature. If an atmospheric analysis does not reflect such balance sufficiently well, the subsequent forecast will exhibit unrealistic behavior associated with spurious fast-propagating gravity waves. Even if these eventually damp, they can create poor background fields for a subsequent analysis or interact with moist physics to create spurious precipitation. The nature of this problem will be described along with the reasons for atmospheric balance and techniques for mitigating imbalances. Attention will be focused on fundamental issues rather than on recipes for various techniques.

  2. Viscoelasticity, Postseismic Slip, Fault Interactions, and the Recurrence of Large Earthquakes

    Science.gov (United States)

    Michael, A. J.

    2003-12-01

    Since Reid formulated the elastic rebound hypothesis, our view of earthquake occurrence has been based on the idea of uniform loading leading to recurrent failures. This view was reinforced by the discovery of plate tectonics but, recently, many studies have demonstrated the existence of transient, high deformation rates after large earthquakes due to either viscoelastic processes or post-seismic slip. Viscoelastic response of the lower crust and upper mantle to large earthquakes results in temporarily higher deformation rates in the region surrounding the mainshock. These higher deformation rates will result in faster than average reloading of strain energy onto the mainshock fault. If post-seismic slip is a planar downward extension of the mainshock, then the post-seismic slip will increase the stress stored on the mainshock fault plane. Again, this will result in faster than average loading of strain energy onto the mainshock fault plane for some time immediately following the mainshock. Thus, the loading of strain energy onto seismogenic faults is not temporally uniform and, in this study, I consider the effects of transient deformation on the estimation of earthquake probabilities by modifying the Brownian Passage Time (BPT) model of earthquake recurrence. The BPT inter-event time distribution is derived from a process where a state variable starts at 0, evolves by a superposition of a linear trend and Gaussian white noise until reaching a value of 1 when failure occurs and state is reset to 0. For earthquake recurrence the linear trend represents the uniform deformation due to plate motions and the noise represents fault interactions and other unknown perturbations to the process. To approximate the effects of viscoelasticity and post-seismic slip; I add a decaying exponential term to the BPT model's uniform loading term. The resulting inter-event time distributions remain approximately lognormal but the balance between the level of "noise"and the coefficient

  3. Fault slip and earthquake recurrence along strike-slip faults — Contributions of high-resolution geomorphic data

    KAUST Repository

    Zielke, Olaf

    2015-01-01

    Understanding earthquake (EQ) recurrence relies on information about the timing and size of past EQ ruptures along a given fault. Knowledge of a fault\\'s rupture history provides valuable information on its potential future behavior, enabling seismic hazard estimates and loss mitigation. Stratigraphic and geomorphic evidence of faulting is used to constrain the recurrence of surface rupturing EQs. Analysis of the latter data sets culminated during the mid-1980s in the formulation of now classical EQ recurrence models, now routinely used to assess seismic hazard. Within the last decade, Light Detection and Ranging (lidar) surveying technology and other high-resolution data sets became increasingly available to tectono-geomorphic studies, promising to contribute to better-informed models of EQ recurrence and slip-accumulation patterns. After reviewing motivation and background, we outline requirements to successfully reconstruct a fault\\'s offset accumulation pattern from geomorphic evidence. We address sources of uncertainty affecting offset measurement and advocate approaches to minimize them. A number of recent studies focus on single-EQ slip distributions and along-fault slip accumulation patterns. We put them in context with paleoseismic studies along the respective faults by comparing coefficients of variation CV for EQ inter-event time and slip-per-event and find that a) single-event offsets vary over a wide range of length-scales and the sources for offset variability differ with length-scale, b) at fault-segment length-scales, single-event offsets are essentially constant, c) along-fault offset accumulation as resolved in the geomorphic record is dominated by essentially same-size, large offset increments, and d) there is generally no one-to-one correlation between the offset accumulation pattern constrained in the geomorphic record and EQ occurrence as identified in the stratigraphic record, revealing the higher resolution and preservation potential of

  4. Modeling stick-slip-separation dynamics in a bimodal standing wave ultrasonic motor

    Science.gov (United States)

    Li, Xiang; Yao, Zhiyuan; Lv, Qibao; Liu, Zhen

    2016-11-01

    Ultrasonic motor (USM) is an electromechanical coupling system with ultrasonic vibration, which is driven by the frictional contact force between the stator (vibrating body) and the rotor/slider (driven body). Stick-slip motion can occur at the contact interface when USM is operating, which may affect the performance of the motor. This paper develops a physically-based model to investigate the complex stick-slip-separation dynamics in a bimodal standing wave ultrasonic motor. The model includes both friction nonlinearity and intermittent separation nonlinearity of the system. Utilizing Hamilton's principle and assumed mode method, the dynamic equations of the stator are deduced. Based on the dynamics of the stator and the slider, sticking force during the stick phase is derived, which is used to examine the stick-to-slip transition. Furthermore, the stick-slip-separation kinematics is analyzed by establishing analytical criteria that predict the transition between stick, slip and separation of the interface. Stick-slip-separation motion is observed in the resulting model, and numerical simulations are performed to study the influence of parameters on the range of possible motions. Results show that stick-slip motion can occur with greater preload and smaller voltage amplitude. Furthermore, a dimensionless parameter is proposed to predict the occurrence of stick-slip versus slip-separation motions, and its role in designing ultrasonic motors is discussed. It is shown that slip-separation motion is favorable for the slider velocity.

  5. Fault Slip Model of 2013 Lushan Earthquake Retrieved Based on GPS Coseismic Displacements

    Institute of Scientific and Technical Information of China (English)

    Mengkui Li; Shuangxi Zhang; Chaoyu Zhang; Yu Zhang

    2015-01-01

    Lushan Earthquake (~Mw 6.6) occurred in Sichuan Province of China on 20 April 2013, was the largest earthquake in Longmenshan fault belt since 2008 Wenchuan Earthquake. To better understand its rupture pattern, we focused on the influences of fault parameters on fault slips and performed fault slip inversion using Akaike’s Bayesian Information Criterion (ABIC) method. Based on GPS coseismic data, our inverted results showed that the fault slip was mainly confined at depths. The maximum slip amplitude is about 0.7 m, and the scalar seismic moment is about 9.47×1018 N·m. Slip pattern reveals that the earthquake occurred on the thrust fault with large dip-slip and small strike-slip, such a simple fault slip represents no second sub-event occurred. The Coulomb stress changes (DCFF) matched the most aftershocks with negative anomalies. The in-verted results demonstrated that the source parameters have significant impacts on fault slip distri-bution, especially on the slip direction and maximum displacement.

  6. Interfacial slip on a transverse-shear mode acoustic wave device

    Science.gov (United States)

    Ellis, Jonathan S.; Hayward, Gordon L.

    2003-12-01

    This article describes a mathematical relationship between the slip parameter α and the slip length b for a slip boundary condition applied to the transverse-shear model for a quartz-crystal acoustic wave device. The theory presented here reduces empirical determination of slip to a one-parameter fit. It shows that the magnitude and phase of the slip parameter, which describes the relative motion of the surface and liquid in the transverse-shear model, can be linked to the slip length. Furthermore, the magnitude and phase of the slip parameter are shown to depend on one another. An experiment is described to compare the effects of liquid-surface affinity on the resonant properties of a transverse-shear mode wave device by applying different polar and nonpolar liquids to surfaces of different polarity. The theory is validated with slip values determined from the transverse-shear model and compared to slip length values from literature. Agreement with literature values of slip length is within one order of magnitude.

  7. Estimators of wheel slip for electric vehicles using torque and encoder measurements

    Science.gov (United States)

    Boisvert, M.; Micheau, P.

    2016-08-01

    For the purpose of regenerative braking control in hybrid and electrical vehicles, recent studies have suggested controlling the slip ratio of the electric-powered wheel. A slip tracking controller requires an accurate slip estimation in the overall range of the slip ratio (from 0 to 1), contrary to the conventional slip limiter (ABS) which calls for an accurate slip estimation in the critical slip area, estimated at around 0.15 in several applications. Considering that it is not possible to directly measure the slip ratio of a wheel, the problem is to estimate the latter from available online data. To estimate the slip of a wheel, both wheel speed and vehicle speed must be known. Several studies provide algorithms that allow obtaining a good estimation of vehicle speed. On the other hand, there is no proposed algorithm for the conditioning of the wheel speed measurement. Indeed, the noise included in the wheel speed measurement reduces the accuracy of the slip estimation, a disturbance increasingly significant at low speed and low torque. Herein, two different extended Kalman observers of slip ratio were developed. The first calculates the slip ratio with data provided by an observer of vehicle speed and of propeller wheel speed. The second observer uses an original nonlinear model of the slip ratio as a function of the electric motor. A sinus tracking algorithm is included in the two observers, in order to reject harmonic disturbances of wheel speed measurement. Moreover, mass and road uncertainties can be compensated with a coefficient adapted online by an RLS. The algorithms were implemented and tested with a three-wheel recreational hybrid vehicle. Experimental results show the efficiency of both methods.

  8. Assessing the Updip Spatial Offset of Tremor and Slip during ETS Events in Cascadia

    Science.gov (United States)

    Krogstad, R. D.; Schmidt, D. A.

    2015-12-01

    We investigate the updip spatial overlap of tremor and slip during recent episodic tremor and slip (ETS) events in Cascadia using a combination of forward and inverse models constrained by GPS, strainmeter, and tremor observations. Results from major ETS events in northern Cascadia suggest that, although there is significant spatial overlap, slow slip tends to extend further updip than tremor. ETS activity is thought to be dependent on a range of parameters, such as variable fluid pressures, temperature dependent physical properties, and facies changes. A spatial offset would indicant that tremor and slip are reflective of different physical conditions. While a clear offset of tremor and slip has been observed in multiple other subduction zones, a similar offset in Cascadia has remained difficult to constrain. Here we seek to establish whether the updip spatial offset is real in Cascadia and to quantify its extent. To complement GPS observations in Cascadia, we incorporate high fidelity strainmeter observations into inversions and sensitivity tests of iterative forward models. Tremor distributions are used as a proxy for slip and incorporated into slip models where parameters affecting the distribution and magnitude of slip are allowed to vary. These slip models are used to forward predict surface displacements and strains, which are then compared to the geodetic observations and inferred slip based on geodetic inversions. Results indicate that, while the tremor-derived slip distributions do a good job predicting the broad-scale surface deformation, the best-fit models have slip updip of the peak tremor activity. The fine-scale relationship of tremor and slip appears to vary on an event-by-event basis, where areas of high tremor density do not always correlate with increased surface displacements and vice-versa.

  9. Slow Slip History for the MEXICO Subduction Zone: 2005 Through 2011

    Science.gov (United States)

    Graham, Shannon; DeMets, Charles; Cabral-Cano, Enrique; Kostoglodov, Vladimir; Rousset, Baptiste; Walpersdorf, Andrea; Cotte, Nathalie; Lasserre, Cécile; McCaffrey, Robert; Salazar-Tlaczani, Luis

    2016-10-01

    To further our understanding of the seismically hazardous Mexico subduction zone, we estimate the first time-dependent slip distributions and Coulomb failure stress changes for the six major slow slip events (SSEs) that occurred below Mexico between late 2005 and mid-2011. Slip dist ributions are the first to be estimated from all continuous GPS data in central and southern Mexico, which better resolves slow slip in space and time than was previously possible in this region. Below Oaxaca, slip during previously un-modeled SSEs in 2008/9 and 2010/11 extended farther to the west than previous SSEs. This constitutes the first evidence that slow slip accounts for deep slip within a previously noted gap between the Oaxaca and Guerrero SSE source regions. The slip that we estimate for the two SSEs that originated below Guerrero between 2005 and 2011 agrees with slip estimated in previous, mostly static-offset SSE modeling studies; however, we show that both SSEs migrated eastward toward the Oaxaca SSE source region. In accord with previous work, we find that slow slip below Guerrero intrudes up-dip into the potentially seismogenic region, presumably accounting for some of the missing slip within the well-described Guerrero seismic gap. In contrast, slow slip below Oaxaca between 2005 and 2011 occurred mostly down-dip from the seismogenic regions defined by the rupture zones of large thrust earthquakes in 1968 and 1978 and released all of the slip deficit that accumulated in the down-dip region during this period.

  10. Modeling shallow slip deficit in large strike-slip earthquakes using simulations of spontaneous earthquake sequences in elasto-plastic media

    Science.gov (United States)

    Kaneko, Y.; Fialko, Y.

    2010-12-01

    Slip inversions of several large strike-slip earthquakes point to coseismic slip deficit at shallow depths (Sierra El Mayor (Mexico) earthquake. Determining the origin of shallow slip deficit is important both for understanding physics of earthquakes and for estimating seismic hazard, as suppression of shallow rupture could greatly influence strong ground motion in the vicinity of active faults. Several mechanisms may be invoked to explain the deficit. A widely accepted interpretation is the presence of velocity-strengthening fault friction at shallow depths where the coseismic slip deficit is compensated by afterslip and interseismic creep. However, geodetic observations indicate that the occurrence of interseismic creep and afterslip at shallow depths is rather uncommon, except for certain locations near major creeping segments of mature faults and/or in areas with thick sedimentary covers with overpressurized pore fluids (e.g., Wei et al., 2009). Fialko et al. (2005) proposed that extensive inelastic failure of the shallow crust in the interseismic period or during earthquakes may result in coseismic slip deficit at shallow depths. In this work, we investigate whether inelastic failure of the shallow crust can lead to shallow coseismic slip deficit using simulations of spontaneous earthquake sequences on vertical planar strike-slip faults. To account for inelastic deformation, we incorporate off-fault plasticity into 2-D models of earthquake sequences on faults governed by laboratory-derived rate and state friction (Kaneko et al., 2010). Our preliminary results suggest that coseismic slip deficit could occur in a wide range of parameters that characterize inelastic material properties. We will report on our current efforts on identifying key parameters of fault friction and bulk rheology that link to the degree of coseismic slip deficit over multiple earthquake cycles.

  11. The Balanced Company

    DEFF Research Database (Denmark)

    Controlling the sustainability of production processes and ethical employment of the work force in suppliers' production facilities far away from the home country has resulted in new challenges for managers. They now have to consider how important it is for customers, investors and employees to see...... that a company is respected in wider society and behaves according to ethical standards. Strategists and Leaders need to make balanced choices about long-term goals and the allocation of resources. They need to analyse, understand and adjust strategies to market, political, value and technology related changes...... in their environments. Communication specialists need to make balanced decisions which take the different value systems and assumptions of stakeholders into consideration. Change specialists need to balance the need for continuity and change. Managers need to make balanced decisions about whether to achieve goals...

  12. Energy balance measurement

    DEFF Research Database (Denmark)

    Dhurandhar, N V; Schoeller, D; Brown, A W;

    2014-01-01

    Energy intake (EI) and physical activity energy expenditure (PAEE) are key modifiable determinants of energy balance, traditionally assessed by self-report despite its repeated demonstration of considerable inaccuracies. We argue here that it is time to move from the common view that self-reports...... of energy balance.International Journal of Obesity advance online publication, 23 December 2014; doi:10.1038/ijo.2014.199.......Energy intake (EI) and physical activity energy expenditure (PAEE) are key modifiable determinants of energy balance, traditionally assessed by self-report despite its repeated demonstration of considerable inaccuracies. We argue here that it is time to move from the common view that self......-reports of EI and PAEE are imperfect, but nevertheless deserving of use, to a view commensurate with the evidence that self-reports of EI and PAEE are so poor that they are wholly unacceptable for scientific research on EI and PAEE. While new strategies for objectively determining energy balance...

  13. Pascal's Wager, infective endocarditis and the "no-lose" philosophy in medicine.

    Science.gov (United States)

    Shaw, D; Conway, D I

    2010-01-01

    Doctors and dentists have traditionally used antibiotic prophylaxis in certain patient groups in order to prevent infective endocarditis (IE). New guidelines, however, suggest that the risk to patients from using antibiotics is higher than the risk from IE. This paper analyses the relative risks of prescribing and not prescribing antibiotic prophylaxis against the background of Pascal's Wager, the infamous assertion that it is better to believe in God regardless of evidence, because of the prospective benefits should He exist. Many doctors seem to believe the parallel proposition that it is better to prescribe antibiotics, regardless of evidence, because of the prospective benefit conferred upon the patient. This has been called the "no lose philosophy" in medicine: better safe than sorry, even if the evidence inconveniently suggests that following this mantra is potentially more likely to result in sorry than safe. It transpires that, just as Pascal's Wager fails to convince because of a lack of evidence to support it and the costs incurred by trying to believe, so the "belts and braces" approach of prescribing antibiotic prophylaxis is unjustifiable given the actual evidence of potential risk and benefit to the patient. Ultimately, there is no no-lose if your clinical decisions, like Pascal's Wager, are based on faith rather than evidence.

  14. Win-stay-lose-learn promotes cooperation in the spatial prisoner's dilemma game.

    Science.gov (United States)

    Liu, Yongkui; Chen, Xiaojie; Zhang, Lin; Wang, Long; Perc, Matjaž

    2012-01-01

    Holding on to one's strategy is natural and common if the later warrants success and satisfaction. This goes against widespread simulation practices of evolutionary games, where players frequently consider changing their strategy even though their payoffs may be marginally different than those of the other players. Inspired by this observation, we introduce an aspiration-based win-stay-lose-learn strategy updating rule into the spatial prisoner's dilemma game. The rule is simple and intuitive, foreseeing strategy changes only by dissatisfied players, who then attempt to adopt the strategy of one of their nearest neighbors, while the strategies of satisfied players are not subject to change. We find that the proposed win-stay-lose-learn rule promotes the evolution of cooperation, and it does so very robustly and independently of the initial conditions. In fact, we show that even a minute initial fraction of cooperators may be sufficient to eventually secure a highly cooperative final state. In addition to extensive simulation results that support our conclusions, we also present results obtained by means of the pair approximation of the studied game. Our findings continue the success story of related win-stay strategy updating rules, and by doing so reveal new ways of resolving the prisoner's dilemma.

  15. Win-stay-lose-learn promotes cooperation in the spatial prisoner's dilemma game.

    Directory of Open Access Journals (Sweden)

    Yongkui Liu

    Full Text Available Holding on to one's strategy is natural and common if the later warrants success and satisfaction. This goes against widespread simulation practices of evolutionary games, where players frequently consider changing their strategy even though their payoffs may be marginally different than those of the other players. Inspired by this observation, we introduce an aspiration-based win-stay-lose-learn strategy updating rule into the spatial prisoner's dilemma game. The rule is simple and intuitive, foreseeing strategy changes only by dissatisfied players, who then attempt to adopt the strategy of one of their nearest neighbors, while the strategies of satisfied players are not subject to change. We find that the proposed win-stay-lose-learn rule promotes the evolution of cooperation, and it does so very robustly and independently of the initial conditions. In fact, we show that even a minute initial fraction of cooperators may be sufficient to eventually secure a highly cooperative final state. In addition to extensive simulation results that support our conclusions, we also present results obtained by means of the pair approximation of the studied game. Our findings continue the success story of related win-stay strategy updating rules, and by doing so reveal new ways of resolving the prisoner's dilemma.

  16. Application of integral pumping tests to investigate the influence of a losing stream on groundwater quality

    Science.gov (United States)

    Leschik, S.; Musolff, A.; Krieg, R.; Martienssen, M.; Bayer-Raich, M.; Reinstorf, F.; Strauch, G.; Schirmer, M.

    2009-10-01

    Losing streams that are influenced by wastewater treatment plant effluents and combined sewer overflows (CSOs) can be a source of groundwater contamination. Released micropollutants such as pharmaceuticals, endocrine disrupters and other ecotoxicologically relevant substances as well as inorganic wastewater constituents can reach the groundwater, where they may deteriorate groundwater quality. This paper presents a method to quantify exfiltration mass flow rates per stream length unit Mex of wastewater constituents from losing streams by the operation of integral pumping tests (IPTs) up- and downstream of a target section. Due to the large sampled water volume during IPTs the results are more reliable than those from conventional point sampling. We applied the method at a test site in Leipzig (Germany). Wastewater constituents K+ and NO3- showed Mex values of 1241 to 4315 and 749 to 924 mg mstream-1 d-1, respectively, while Cl- (16.8 to 47.3 g mstream-1 d-1) and SO42- (20.3 to 32.2 g mstream-1 d-1) revealed the highest observed Mex values at the test site. The micropollutants caffeine and technical-nonylphenol were dominated by elimination processes in the groundwater between upstream and downstream wells. Additional concentration measurements in the stream and a connected sewer at the test site were performed to identify relevant processes that influence the concentrations at the IPT wells.

  17. [Having and losing friends: necessary social-emotional competencies in adolescents].

    Science.gov (United States)

    von Salisch, Maria; Lüpschen, Nadine; Kanevski, Rimma

    2013-01-01

    Supportive friendships are an invaluable resource for adolescents because of their various developmental tasks, but establishing and maintaining them requires particular interpersonal skills. In order to identify social-emotional competencies associated with having and losing friends, N = 206 early adolescents (12-14 years of age) were examined longitudinally right after the transition to secondary school in the beginning of grade 7 and again at the end of this school year. Adolescents who had at least one reciprocal friend at both times were compared to those who lost all their friends over the school year. Repeated-measures MANOVAs indicate effects of time (and development) that underline an increase of self-disclosure, explanations and humor as well as a general decrease of openly aggressive behavior when angry at the friend. Interaction effects suggest that adolescents who lost their friend(s) intensified their use of physically and relationally aggressive behavior and of fantasies of revenge over time while continuously befriended adolescents decreased in their aggressive behavior when coping with anger in their friendships. Adolescents who had friends at both times were more willing to disclose private information whereas the self-disclosure of adolescents who lost their friends stagnated. These results are discussed in terms of deficient social-emotional competencies as the cause and the consequence of losing friends.

  18. Strategy changes in subsequent fights as consequences of winning and losing in fruit fly fights.

    Science.gov (United States)

    Trannoy, Séverine; Kravitz, Edward A

    2016-11-11

    In competition for food, territory and mates, male fruit flies (Drosophila melanogaster) engage in agonistic encounters with conspecifics. The fighting strategies used to obtain these resources are influenced by previous and present experience, environmental cues, and the internal state of the animal including hormonal and genetic influences. Animals that experience prior defeats show submissive behavior and are more likely to lose 2(nd) contests, while animals that win 1(st) fights are more aggressive and have a higher probability of winning 2(nd) contests. In a recent report, we examined these loser and winner effects in greater detail and demonstrated that both winners and losers show short-term memory of the results of previous bouts while only losers demonstrate a longer-term memory that requires protein synthesis. The recent findings also suggested that an individual recognition mechanism likely exists that can serve important roles in evaluating the fighting ability of opponents and influencing future fighting strategy. In this article, we follow up on these results by asking how previous defeated and victorious flies change their fighting strategies in the presence of 2(nd) losing and winning flies, by searching for evidence of territory marking, and discussing the existing literature in light of our findings.

  19. Protein-losing enteropathy as a rare complication of the ketogenic diet.

    Science.gov (United States)

    Moriyama, Kengo; Watanabe, Mio; Yamada, Yoshiyuki; Shiihara, Takashi

    2015-05-01

    The ketogenic diet is a valuable therapy for patients with intractable epilepsy, but it can result in a variety of complications that sometimes limits its usefulness. Hypoproteinemia is one of the common adverse effects of this diet, although the underling mechanism is largely unknown except for the diet's reduced protein intake. Only one case of protein-losing enteropathy during the ketogenic diet has been reported. A previously healthy 9-year-old girl experienced fever for 5 days then suddenly developed convulsive seizures that subsequently evolved to severe refractory status epilepticus. After multiple antiepileptic drugs failed to improve the patient's condition, we introduced the ketogenic diet. Although her seizures diminished, her course was complicated by hypoproteinemia. An abdominal dynamic scintigraphy and colonoscopy findings indicated protein-losing enteropathy with nonspecific mucosal inflammation. Her nutritional status deteriorated; thus, we discontinued the ketogenic diet. Her nutritional status gradually improved, whereas her seizures increased. Hypoproteinemia during the ketogenic diet is common, but the underlying etiologies are not well understood. Abdominal dynamic scintigraphy could be valuable for clarifying the etiology of hypoproteinemia during the ketogenic diet. Copyright © 2015 Elsevier Inc. All rights reserved.

  20. Technical and Tactical Aspects that Differentiate Winning and Losing Performances in Elite Male Karate Fighters.

    Science.gov (United States)

    Vidranski, Tihomir; Sertić, Hrvoje; Jukić, Josefina

    2015-07-01

    The purpose of this research was to identify the fighters' technical and tactical activity indicators in order to determine indicator significance regarding situational efficiency and designation between winning and losing performances in a karate match. We scientifically observed a sample of 274 male contesters of 137 karate matches during the 2008 World Karate Championship in Tokyo. Each individual competitor was observed in maximum of three matches. The matches were recorded using a DVD camera in order to collect data for further analysis, and the sample was further described using 48 technical and tactical indicators of situational efficiency and match outcome variables. The obtained results indicate that a karate match is composed of 91% of non-scoring techniques and 9% of scoring techniques in the total technique frequency. On this basis a significant difference in the situational efficiency between the match winners and the losing contesters has been discovered. Those two groups of fighters exhibit a statistically significant difference (pkarate match are in the largest extent defined by non-scoring techniques. Therefore, it would be a grave mistake to disregard non-scoring karate techniques in any future situational efficiency studies. It has been discovered that the winners differ from the defeated contesters by a higher level of situational efficiency in their executed techniques, which incorporate versatility, biomechanical and structural complexity, topological diversity and a specific tactical concept of technique use in the attack phase.

  1. The cost of defeat: Capuchin groups travel further, faster and later after losing conflicts with neighbors.

    Science.gov (United States)

    Crofoot, Margaret C

    2013-09-01

    Although competition between social groups is central to hypotheses about the evolution of human social organization, competitive interactions among group-mates are thought to play a more dominant role in shaping the behavior and ecology of other primate species. However, few studies have directly tested the impact of intergroup conflicts in non-human primates. What is the cost of defeat? To address this question, the movements of six neighboring white-faced capuchin (Cebus capucinus) social groups living on Barro Colorado Island, Panama were tracked simultaneously using an Automated Radio Telemetry System (ARTS), for a period of six months. Groups moved 13% (441 m) further on days they lost interactions compared with days they won interactions. To cover these larger distances, they traveled faster, stopped less frequently, and remained active later in the evening. Defeat also caused groups to alter their patterns of space use. Losing groups had straighter travel paths than winning groups, larger net displacements and were more likely to change their sleeping site. These results demonstrate that losing groups pay increased travel costs and suggest that they forage in low-quality areas. They provide some of the first direct evidence that intergroup conflicts have important energetic consequences for members of competitively unsuccessful primate social groups. A better understanding of how intergroup competition impacts patterns of individual fitness is thus needed to clarify the role that this group-level process plays in shaping the evolution of human- and non-human primate behavior.

  2. Win-Stay-Lose-Learn Promotes Cooperation in the Spatial Prisoner's Dilemma Game

    Science.gov (United States)

    Liu, Yongkui; Chen, Xiaojie; Zhang, Lin; Wang, Long; Perc, Matjaž

    2012-01-01

    Holding on to one's strategy is natural and common if the later warrants success and satisfaction. This goes against widespread simulation practices of evolutionary games, where players frequently consider changing their strategy even though their payoffs may be marginally different than those of the other players. Inspired by this observation, we introduce an aspiration-based win-stay-lose-learn strategy updating rule into the spatial prisoner's dilemma game. The rule is simple and intuitive, foreseeing strategy changes only by dissatisfied players, who then attempt to adopt the strategy of one of their nearest neighbors, while the strategies of satisfied players are not subject to change. We find that the proposed win-stay-lose-learn rule promotes the evolution of cooperation, and it does so very robustly and independently of the initial conditions. In fact, we show that even a minute initial fraction of cooperators may be sufficient to eventually secure a highly cooperative final state. In addition to extensive simulation results that support our conclusions, we also present results obtained by means of the pair approximation of the studied game. Our findings continue the success story of related win-stay strategy updating rules, and by doing so reveal new ways of resolving the prisoner's dilemma. PMID:22363470

  3. 2013 social balance sheet

    OpenAIRE

    Pierrette Heuse

    2014-01-01

    The transposition into national law of Directive 2013/34/EU on the annual financial statements of companies, expected by no later than July 2015, could alter the statistical obligations on small firms in connection with the filing of their annual accounts. In any case, the social balance sheet can no longer form an integral part of their accounts. Nevertheless, it contains original information whose usefulness is highlighted, on the basis of the social balance sheets for 2012, by examining th...

  4. Balance Function Disorders

    Science.gov (United States)

    1991-01-01

    Researchers at the Balance Function Laboratory and Clinic at the Minneapolis (MN) Neuroscience Institute on the Abbot Northwestern Hospital Campus are using a rotational chair (technically a "sinusoidal harmonic acceleration system") originally developed by NASA to investigate vestibular (inner ear) function in weightlessness to diagnose and treat patients with balance function disorders. Manufactured by ICS Medical Corporation, Schaumberg, IL, the chair system turns a patient and monitors his or her responses to rotational stimulation.

  5. Balances instruments, manufacturers, history

    CERN Document Server

    Robens, Erich; Kiefer, Susanne

    2014-01-01

    The book deals mainly with direct mass determination by means of a conventional balances. It covers the history of the balance from the beginnings in Egypt earlier than 3000 BC to recent developments. All balance types are described with emphasis on scientific balances. Methods of indirect mass determination, which are applied to very light objects like molecules and the basic particles of matter and celestial bodies, are included.  As additional guidance, today’s manufacturers are listed and the profile of important companies is reviewed. Several hundred photographs, reproductions and drawings show instruments and their uses. This book includes commercial weighing instruments for merchandise and raw materials in workshops as well as symbolic weighing in the ancient Egyptian’s ceremony of ‘Weighing of the Heart’, the Greek fate balance, the Roman  Justitia, Juno Moneta and Middle Ages scenes of the Last Judgement with Jesus or St. Michael and of modern balances. The photographs are selected from the...

  6. Vibration Analysis of Steel-Concrete Composite Box Beams considering Shear Lag and Slip

    Directory of Open Access Journals (Sweden)

    Zhou Wangbao

    2015-01-01

    Full Text Available In order to investigate dynamic characteristics of steel-concrete composite box beams, a longitudinal warping function of beam section considering self-balancing of axial forces is established. On the basis of Hamilton principle, governing differential equations of vibration and displacement boundary conditions are deduced by taking into account coupled influencing of shear lag, interface slip, and shear deformation. The proposed method shows an improvement over previous calculations. The central difference method is applied to solve the differential equations to obtain dynamic responses of composite beams subjected to arbitrarily distributed loads. The results from the proposed method are found to be in good agreement with those from ANSYS through numerical studies. Its validity is thus verified and meaningful conclusions for engineering design can be drawn as follows. There are obvious shear lag effects in the top concrete slab and bottom plate of steel beams under dynamic excitation. This shear lag increases with the increasing degree of shear connections. However, it has little impact on the period and deflection amplitude of vibration of composite box beams. The amplitude of deflection and strains in concrete slab reduce as the degree of shear connections increases. Nevertheless, the influence of shear connections on the period of vibration is not distinct.

  7. Slipped upper femoral epiphysis: imaging of complications after treatment

    Energy Technology Data Exchange (ETDEWEB)

    Tins, B. [Robert Jones and Agnes Hunt Orthopaedic and District Hospital, Twmpath Lane, Oswestry, Shropshire (United Kingdom)], E-mail: bernhard.tins@rjah.nhs.uk; Cassar-Pullicino, V.; McCall, I. [Robert Jones and Agnes Hunt Orthopaedic and District Hospital, Twmpath Lane, Oswestry, Shropshire (United Kingdom)

    2008-01-15

    Slipped upper femoral epiphysis (SUFE) is a multifactorial condition usually affecting adolescents. Obesity is one risk factor, and as this is increasing the incidence of SUFE is likely to rise. Diagnosis and treatment are usually straightforward and carried out by orthopaedic surgeons. However, the recognition of post-treatment complications poses a much greater challenge. This article focuses on possible complications of surgical treatment of SUFE particularly. Chondrolysis, avascular necrosis, as well as other complications of treatment and conditions leading to premature osteoarthritis are discussed. Checklists for a systematic approach to post-treatment imaging are provided.

  8. Parameter identification and slip estimation of induction machine

    Science.gov (United States)

    Orman, Maciej; Orkisz, Michal; Pinto, Cajetan T.

    2011-05-01

    This paper presents a newly developed algorithm for induction machine rotor speed estimation and parameter detection. The proposed algorithm is based on spectrum analysis of the stator current. The main idea is to find the best fit of motor parameters and rotor slip with the group of characteristic frequencies which are always present in the current spectrum. Rotor speed and parameters such as pole pairs or number of rotor slots are the results of the presented algorithm. Numerical calculations show that the method yields very accurate results and can be an important part of machine monitoring systems.

  9. Dynamic Weakening by Acoustic Fluidization during Stick-Slip Motion.

    Science.gov (United States)

    Giacco, F; Saggese, L; de Arcangelis, L; Lippiello, E; Pica Ciamarra, M

    2015-09-18

    The unexpected weakness of some faults has been attributed to the emergence of acoustic waves that promote failure by reducing the confining pressure through a mechanism known as acoustic fluidization, also proposed to explain earthquake remote triggering. Here we validate this mechanism via the numerical investigation of a granular fault model system. We find that the stick-slip dynamics is affected only by perturbations applied at a characteristic frequency corresponding to oscillations normal to the fault, leading to gradual dynamical weakening as failure is approaching. Acoustic waves at the same frequency spontaneously emerge at the onset of failure in the absence of perturbations, supporting the relevance of acoustic fluidization in earthquake triggering.

  10. Photoinduced "stick-slip" on superhydrophilic semiconductor surfaces.

    Science.gov (United States)

    Denison, Kieth R; Boxall, Colin

    2007-04-10

    Transparent mesoporous TiO2 (M-TiO2) thin films were prepared on quartz via a reverse micelle, sol-gel, spin-coating technique. Films were characterized by atomic force microscopy (AFM) and Raman and UV-vis spectroscopies and were found to be mostly anatase with low surface roughness (Rt approximately 5 nm). The time dependence of film photoinduced superhydrophilicity (PISH) was measured by observation of the spreading of a sessile water drop using a new, continuous measurement technique wherein the drop was first applied to the semiconductor surface and then was filmed while it and the underlying substrate were illuminated by 315 nm ultraband gap light. Results obtained at 100% relative humidity (RH) at 293 K showed that drops on M-TiO2 surfaces exhibited a photoinduced "stick-slip" behavior, the first time such an effect has been observed. The thermodynamic driving force for this photoinduced stick-slip was the departure of the system from capillary equilibrium as, with increasing illumination time, the concentration of surface Ti-OH groups increased and the equilibrium contact angle of the drop, theta0, decreased. A simple theoretical description of photoinduced stick-slip is derived and is used to calculate a value of the potential energy barrier associated with surface inhomogeneities that oppose onset of movement of the triple line, U = 6.63 x 10(-6) J m(-1). This is the first time that U has been quantified for a surface with photoinduced superhydrophilicity. Triple line retreat measurements on an evaporating drop on M-TiO2 in the dark, RH = 60%, T = 293 K, gave a value of U = 9.4 x 10(-6) J m(-1), indicating that U decreases upon UV illumination and that U in the light is primarily associated with inhomogeneities that are unaffected by an increase in the surface Ti-OH population, such as the physical roughness of the surface. In the dark evaporation experiment, the drop was found to retreat with an areal velocity of 1.48 x 10(-8) m2 s(-1). However, under UV

  11. Thermophoresis at a charged surface: the role of hydrodynamic slip.

    Science.gov (United States)

    Morthomas, Julien; Würger, Alois

    2009-01-21

    By matching boundary layer hydrodynamics with slippage to the force-free flow at larger distances, we obtain the thermophoretic mobility of charged particles as a function of the Navier slip length b. A moderate value of b augments Ruckenstein's result by a term 2b/λ, where λ is the Debye length. If b exceeds the particle size a, the enhancement coefficient a/λ is independent of b but proportional to the particle size. Similar effects occur for transport driven by a salinity gradient or by an electric field.

  12. Additional slip of pectoralis major muscle – the costohumeralis

    Directory of Open Access Journals (Sweden)

    Rao TR

    2009-03-01

    Full Text Available We present a rare case of costohumeralis muscle, an accessory slip originating from the sixth rib near costochondral junction and running along the lower border of the pectoralis major muscle, inserting onto the medial epicondyle of the humerus on the right side. The occurrence of this costohumeralis muscle also showed a coincidental loss of the classical twisting of the tendinous insertion of the pectoralis major muscle, which proves that this muscle is variable in its development and attachment. Clinical considerations of such a variation include ulnar nerve entrapment and functionally limited abduction of humerus.

  13. Slip systems, dislocation boundaries and lattice rotations in deformed metals

    DEFF Research Database (Denmark)

    Winther, Grethe

    2009-01-01

    strains at room temperature are analysed. A major result is that, by contrast to previous beliefs, the boundaries align with specific crystallographic planes, which depend on the crystallographic grain orientation. This grain orientation dependence originates from an underlying dependence of the active...... of the mechanical anisotropy of rolled sheets. The rotation of the crystallographic lattice in each grain during deformation also exhibits grain orientation dependence, originating from the slip systems. A combined analysis of dislocation boundaries and lattice rotations concludes that the two phenomena are coupled...

  14. Theory of fluid slip in charged capillary nanopores

    CERN Document Server

    Catalano, J; Biesheuvel, P M

    2016-01-01

    Based on the capillary pore model (space-charge theory) for combined fluid and ion flow through cylindrical nanopores or nanotubes, we derive the continuum equations modified to include wall slip. We focus on the ionic conductance and streaming conductance, cross-coefficients of relevance for electrokinetic energy conversion and electro-osmotic pumping. We combine the theory with a Langmuir-Stern 1-pK charge regulation boundary condition resulting in a non-monotonic dependence of the cross-coefficients on salt concentration.

  15. Fatigue Hardening and Nucleation of Persistent Slip Bands in Copper

    DEFF Research Database (Denmark)

    Pedersen, Ole Bøcker; Winter, A. T.

    1982-01-01

    that there is a large volume fraction of obstacles to plastic flow which are essentially non-deformable and give rise to inclusion stresses of considerable magnitude. The much lower hardening rates in cycles after saturation when persistent slip bands have formed suggest a lower volume fraction of obstacles......, as is observed by transmission electron microscopy. A simple composite model involving an inclusion stress, a bowing stress and a passing, stress accounts for the workhardening rates semi-quantitatively in terms of observed dislocation microstructures. Possible implications for polycrystals are considered....

  16. Topological Effects on Quantum Phase Slips in Superfluid Spin Transport

    Science.gov (United States)

    Kim, Se Kwon; Tserkovnyak, Yaroslav

    2016-03-01

    We theoretically investigate effects of quantum fluctuations on superfluid spin transport through easy-plane quantum antiferromagnetic spin chains in the large-spin limit. Quantum fluctuations result in the decaying spin supercurrent by unwinding the magnetic order parameter within the easy plane, which is referred to as phase slips. We show that the topological term in the nonlinear sigma model for the spin chains qualitatively differentiates the decaying rate of the spin supercurrent between the integer versus half-odd-integer spin chains. An experimental setup for a magnetoelectric circuit is proposed, in which the dependence of the decaying rate on constituent spins can be verified by measuring the nonlocal magnetoresistance.

  17. Slip effects associated with Knudsen transport phenomena in porous media

    Science.gov (United States)

    Frederking, T. H. K.; Hepler, W. A.; Khandhar, P. K.

    1988-01-01

    Porous media used in phase separators and thermomechanical pumps have been the subject of characterization efforts based on the Darcy permeability of laminar continuum flow. The latter is not always observed at low speed, in particular at permeabilities below 10 to the -9th/squared cm. The present experimental and theoretical studies address questions of slip effects associated with long mean free paths of gas flow at room temperature. Data obtained are in good agreement, within data uncertainty, with a simplified asymptotic Knudsen equation proposed for porous plugs on the basis of Knudsen's classical flow equation for long mean free paths.

  18. Abating Earthquake Effects on Buildings by Active Slip Brace Devices

    Directory of Open Access Journals (Sweden)

    Zekai Akbay

    1995-01-01

    Full Text Available A hybrid control system for reducing building vibration under a spectrum of earthquake load amplitudes is presented. The hybrid control is accomplished by an energy dissipation device called the active slip brace device (ASBD. The hybrid control system uses the ASBD to regulate the energy dissipation characteristics of the building during its response to earthquakes by utilizing active control principles. The ASBD consists of a Coulomb friction interface with a clamping mechanism on the interface. The clamping force on the friction interface is altered at short time intervals during building vibration. Computer simulations of building response with and without ASBD are compared.

  19. Corrected second-order slip boundary condition for fluid flows in nanochannels.

    Science.gov (United States)

    Zhang, Hongwu; Zhang, Zhongqiang; Zheng, Yonggang; Ye, Hongfei

    2010-06-01

    A corrected second-order slip boundary condition is proposed to solve the Navier-Stokes equations for fluid flows confined in parallel-plate nanochannels. Compared with the classical second-order slip boundary condition proposed by Beskok and Karniadakis, the corrected slip boundary condition is not only dependent on the Knudsen number and the tangential momentum accommodation coefficient, but also dependent on the relative position of the slip surface in the Knudsen layer. For the fluid flows in slip-flow regime with the Knudsen number less than 0.3, Couette cell is investigated using molecular-dynamics simulations to verify Newtonian flow behaviors by examining the constitutive relationship between shear stress and strain rate. By comparing the velocity profiles of Poiseuille flows predicted from the Navier-Stokes equations with the corrected slip boundary condition with that from molecular-dynamics simulations, it is found that the flow behaviors in our models can be effectively captured.

  20. The seasonal dependence of cycle slip occurrence of GPS data over China low latitude region

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The relationship of daily accumulated cycle slip occurrence with the season is analyzed using the GPS data observed in six GPS stations located in China low latitude region in 2001. It is found that the seasonal dependence of cycle slip oc-currence is evident. The cycle slip mainly occurs during the periods of two equinox months (March to May and September to October), and some correlative changes of the cycle slip occurrences over all six stations are exhibited in some special days. Considering the diurnal dependence of cycle slip, it can be inferred that the cycle slip occurrence with certain elevation limitation is related with the iono-spheric irregularities over this region.

  1. Slow slip hidden in the noise: the intermittence of tectonic release

    Science.gov (United States)

    Frank, W.

    2016-12-01

    Referred to as slow slip events, the transient aseismic slip that occurs along plate boundaries can be indirectly characterized through colocated seismicity, such as tectonic tremor and low-frequency earthquakes (LFEs). Using the timing of cataloged LFE and tremor activity in Guerrero, Mexico and northern Cascadia, I decompose the inter-aseismic GPS displacement, defined as the surface deformation between previously detected slow slip events, into separate regimes of tectonic loading and release. In such a way, previously undetected slow slip events that produce on average less than a millimeter of surface deformation are extracted from the geodetic noise. These new observations demonstrate that the inter-aseismic period is not quiescent and that slow slip occurs much more often than previously thought. This suggests that the plate interface where slow slip and tremor occur is in fact strongly coupled and undergoes rapid cycles of stress accumulation and release.

  2. Large fault slip peaking at trench in the 2011 Tohoku-oki earthquake

    Science.gov (United States)

    Sun, Tianhaozhe; Wang, Kelin; Fujiwara, Toshiya; Kodaira, Shuichi; He, Jiangheng

    2017-01-01

    During the 2011 magnitude 9 Tohoku-oki earthquake, very large slip occurred on the shallowest part of the subduction megathrust. Quantitative information on the shallow slip is of critical importance to distinguishing between different rupture mechanics and understanding the generation of the ensuing devastating tsunami. However, the magnitude and distribution of the shallow slip are essentially unknown due primarily to the lack of near-trench constraints, as demonstrated by a compilation of 45 rupture models derived from a large range of data sets. To quantify the shallow slip, here we model high-resolution bathymetry differences before and after the earthquake across the trench axis. The slip is determined to be about 62 m over the most near-trench 40 km of the fault with a gentle increase towards the trench. This slip distribution indicates that dramatic net weakening or strengthening of the shallow fault did not occur during the Tohoku-oki earthquake.

  3. NUMERICAL STUDY OF THE RELATIONSHIP BETWEEN APPARENT SLIP LENGTH AND CONTACT ANGLE BY LATTICE BOLTZMANN METHOD

    Institute of Scientific and Technical Information of China (English)

    ZHANG Ren-liang; DI Qin-feng; WANG Xin-liang; DING Wei-peng; GONG Wei

    2012-01-01

    The apparent slip between solid wall and liquid is studied by using the Lattice Boltzmann Method (LBM) and the Shan-Chen multiphase model in this paper.With a no-slip bounce-back scheme applied to the interface,flow regimes under different wall wettabilities are investigated.Because of the wall wettability,liquid apparent slip is observed.Slip lengths for different wall wettabilities are found to collapse nearly onto a single curve as a function of the static contact angle,and thereby a relationship between apparent slip length and contact angle is suggested.Our results also show that the wall wettability leads to the formation of a low-density layer between solid wall and liquid,which produced apparent slip in the micro-scale.

  4. Watt and joule balances

    Science.gov (United States)

    Robinson, Ian A.

    2014-04-01

    The time is fast approaching when the SI unit of mass will cease to be based on a single material artefact and will instead be based upon the defined value of a fundamental constant—the Planck constant—h . This change requires that techniques exist both to determine the appropriate value to be assigned to the constant, and to measure mass in terms of the redefined unit. It is important to ensure that these techniques are accurate and reliable to allow full advantage to be taken of the stability and universality provided by the new definition and to guarantee the continuity of the world's mass measurements, which can affect the measurement of many other quantities such as energy and force. Up to now, efforts to provide the basis for such a redefinition of the kilogram were mainly concerned with resolving the discrepancies between individual implementations of the two principal techniques: the x-ray crystal density (XRCD) method [1] and the watt and joule balance methods which are the subject of this special issue. The first three papers report results from the NRC and NIST watt balance groups and the NIM joule balance group. The result from the NRC (formerly the NPL Mk II) watt balance is the first to be reported with a relative standard uncertainty below 2 × 10-8 and the NIST result has a relative standard uncertainty below 5 × 10-8. Both results are shown in figure 1 along with some previous results; the result from the NIM group is not shown on the plot but has a relative uncertainty of 8.9 × 10-6 and is consistent with all the results shown. The Consultative Committee for Mass and Related Quantities (CCM) in its meeting in 2013 produced a resolution [2] which set out the requirements for the number, type and quality of results intended to support the redefinition of the kilogram and required that there should be agreement between them. These results from NRC, NIST and the IAC may be considered to meet these requirements and are likely to be widely debated

  5. Losing water in temporary streams on a Mediterranean island: Effects of climate and land-cover changes

    Science.gov (United States)

    Garcia, Celso; Amengual, Arnau; Homar, Víctor; Zamora, Alberto

    2017-01-01

    Temporary streams are unique, sensitive and threatened fluvial systems. They periodically dry up and contribute to biodiversity by supporting different species. In Mediterranean regions, human pressures and climate change increase the duration of the dry period for the streams. We analysed the annual and seasonal trends on streamflow data from 14 gauging stations on temporary streams on the island of Mallorca. We used a Mann-Kendall trend test on data from 1977 to 2009 (33 years) to identify trends in discharge, number of days with water, accumulated precipitation, potential evapotranspiration (PET), and land cover change. Results show a general decreasing trend of streamflow during spring and summer, with flows reduced between 4 and 17% in some basins. Although the inter-annual variability is high for both seasons, the decrease in annual precipitation, the increase in temperature, and the effects of colonization and growth of forests explain the reduction in the number of days with running water. Correlation and elasticity analyses show that precipitation is the main driver for streamflow reduction, but the increase in temperature and land-cover changes also play a significant role in the decreasing of flows. These seasonal changes especially affect the headwaters of the basins, which are located in a mountainous area. The Kendall regional test, applied to the 12 basins considered in the Tramuntana range, reveals a significant decreasing annual trend in the number of days with measured flow. The forest expansion and the warmer conditions cause a higher vegetation water demand, increasing the real evapotranspiration and, consequently, reducing the runoff and thus increasing the losses in the water balance. In addition, the increase in the number of days during which channels and parafluvial habitats are disconnected negatively affects the aquatic habitat. This paper provides the first evidence of a consistent long-term reduction in flow in temporary streams in the

  6. Slip-stacking Dynamics for High-Power Proton Beams at Fermilab

    Energy Technology Data Exchange (ETDEWEB)

    Eldred, Jeffrey Scott [Indiana Univ., Bloomington, IN (United States)

    2015-12-01

    Slip-stacking is a particle accelerator configuration used to store two particle beams with different momenta in the same ring. The two beams are longitudinally focused by two radiofrequency (RF) cavities with a small frequency difference between them. Each beam is synchronized to one RF cavity and perturbed by the other RF cavity. Fermilab uses slip-stacking in the Recycler so as to double the power of the 120 GeV proton beam in the Main Injector. This dissertation investigates the dynamics of slip-stacking beams analytically, numerically and experimentally. In the analytic analysis, I find the general trajectory of stable slip-stacking particles and identify the slip-stacking parametric resonances. In the numerical analysis, I characterize the stable phase-space area and model the particle losses. In particular, I evaluate the impact of upgrading the Fermilab Booster cycle-rate from 15 Hz to 20 Hz as part of the Proton Improvement Plan II (PIP-II). The experimental analysis is used to verify my approach to simulating slip-stacking loss. I design a study for measuring losses from the longitudinal single-particle dynamics of slip-stacking as a function of RF cavity voltage and RF frequency separation. I further propose the installation of a harmonic RF cavity and study the dynamics of this novel slip-stacking configuration. I show the harmonic RF cavity cancels out parametric resonances in slip-stacking, reduces emittance growth during slip-stacking, and dramatically enhances the stable phase-space area. The harmonic cavity is expected to reduce slip-stacking losses to far exceed PIP-II requirements. These results raise the possibility of extending slip-stacking beyond the PIP-II era.

  7. A Network Inversion Filter combining GNSS and InSAR for tectonic slip modeling

    OpenAIRE

    Bekaert, D.; P. Segall; Wright, TJ; Hooper, A.

    2016-01-01

    Studies of the earthquake cycle benefit from long-term time-dependent slip modeling, as it can be a powerful means to improve our understanding on the interaction of earthquake cycle processes such as interseismic, coseismic, postseismic, and aseismic slip. Observations from Interferometric Synthetic Aperture Radar (InSAR) allow us to model slip at depth with a higher spatial resolution than when using GNSS alone. While the temporal resolution of InSAR has typically been limited, the recent f...

  8. Neotectonics of interior Alaska and the late Quaternary slip rate along the Denali fault system

    Science.gov (United States)

    Haeussler, Peter J.; Matmon, Ari; Schwartz, David P.; Seitz, Gordon G.

    2017-01-01

    The neotectonics of southern Alaska (USA) are characterized by a several hundred kilometers–wide zone of dextral transpressional that spans the Alaska Range. The Denali fault system is the largest active strike-slip fault system in interior Alaska, and it produced a Mw 7.9 earthquake in 2002. To evaluate the late Quaternary slip rate on the Denali fault system, we collected samples for cosmogenic surface exposure dating from surfaces offset by the fault system. This study includes data from 107 samples at 19 sites, including 7 sites we previously reported, as well as an estimated slip rate at another site. We utilize the interpreted surface ages to provide estimated slip rates. These new slip rate data confirm that the highest late Quaternary slip rate is ∼13 mm/yr on the central Denali fault near its intersection with the eastern Denali and the Totschunda faults, with decreasing slip rate both to the east and west. The slip rate decreases westward along the central and western parts of the Denali fault system to 5 mm/yr over a length of ∼575 km. An additional site on the eastern Denali fault near Kluane Lake, Yukon, implies a slip rate of ∼2 mm/yr, based on geological considerations. The Totschunda fault has a maximum slip rate of ∼9 mm/yr. The Denali fault system is transpressional and there are active thrust faults on both the north and south sides of it. We explore four geometric models for southern Alaska tectonics to explain the slip rates along the Denali fault system and the active fault geometries: rotation, indentation, extrusion, and a combination of the three. We conclude that all three end-member models have strengths and shortcomings, and a combination of rotation, indentation, and extrusion best explains the slip rate observations.

  9. Slip Model Used for Prediction of r Value of BCC Metal Sheets from ODF Coefficients

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Different slip models were used for prediction of rvalue of BCC metal sheets from ODF coefficients. According to the maximum plastic work theory developed by Bishop and Hill, it is expected that the higher of Taylor factors given by a slip model, the better predictio nobtained based on the model. From this point of view, a composed slip model of BCC metals was presented. Based on the model, the agreement of predicted rvalues for deep drawing steels with experimental ones is excellent.

  10. Analysis of boundary layer flow over a porous nonlinearly stretching sheet with partial slip at

    Directory of Open Access Journals (Sweden)

    Swati Mukhopadhyay

    2013-12-01

    Full Text Available The boundary layer flow of a viscous incompressible fluid toward a porous nonlinearly stretching sheet is considered in this analysis. Velocity slip is considered instead of no-slip condition at the boundary. Similarity transformations are used to convert the partial differential equation corresponding to the momentum equation into nonlinear ordinary differential equation. Numerical solution of this equation is obtained by shooting method. It is found that the horizontal velocity decreases with increasing slip parameter.

  11. Application of Integral Pumping Tests to estimate the influence of losing streams on groundwater quality

    Science.gov (United States)

    Leschik, S.; Musolff, A.; Reinstorf, F.; Strauch, G.; Schirmer, M.

    2009-05-01

    Urban streams receive effluents of wastewater treatment plants and untreated wastewater during combined sewer overflow events. In the case of losing streams substances, which originate from wastewater, can reach the groundwater and deteriorate its quality. The estimation of mass flow rates Mex from losing streams to the groundwater is important to support groundwater management strategies, but is a challenging task. Variable inflow of wastewater with time-dependent concentrations of wastewater constituents causes a variable water composition in urban streams. Heterogeneities in the structure of the streambed and the connected aquifer lead, in combination with this variable water composition, to heterogeneous concentration patterns of wastewater constituents in the vicinity of urban streams. Groundwater investigation methods based on conventional point sampling may yield unreliable results under these conditions. Integral Pumping Tests (IPT) can overcome the problem of heterogeneous concentrations in an aquifer by increasing the sampled volume. Long-time pumping (several days) and simultaneous sampling yields reliable average concentrations Cav and mass flow rates Mcp for virtual control planes perpendicular to the natural flow direction. We applied the IPT method in order to estimate Mex of a stream section in Leipzig (Germany). The investigated stream is strongly influenced by combined sewer overflow events. Four pumping wells were installed up- and downstream of the stream section and operated for a period of five days. The study was focused on four inorganic (potassium, chloride, nitrate and sulfate) and two organic (caffeine and technical-nonylphenol) wastewater constituents with different transport properties. The obtained concentration-time series were used in combination with a numerical flow model to estimate Mcp of the respective wells. The difference of the Mcp's between up- and downstream wells yields Mex of wastewater constituents that increase

  12. Hall and ion slip effects on peristaltic flow of Jeffrey nanofluid with Joule heating

    Science.gov (United States)

    Hayat, T.; Shafique, Maryam; Tanveer, A.; Alsaedi, A.

    2016-06-01

    This paper addresses mixed convective peristaltic flow of Jeffrey nanofluid in a channel with complaint walls. The present investigation includes the viscous dissipation, thermal radiation and Joule heating. Hall and ion slip effects are also taken into account. Related problems through long wavelength and low Reynolds number are examined for stream function, temperature and concentration. Impacts of thermal radiation, Hartman number, Brownian motion parameter, thermophoresis, Joule heating, Hall and ion slip parameters are investigated in detail. It is observed that velocity increases and temperature decreases with Hall and ion slip parameters. Further the thermal radiation on temperature has qualitatively similar role to that of Hall and ion slip effects.

  13. Flow past superhydrophobic surfaces with cosine variation in local slip length

    CERN Document Server

    Asmolov, Evgeny S; Harting, Jens; Vinogradova, Olga I

    2012-01-01

    Anisotropic super-hydrophobic surfaces have the potential to greatly reduce drag and enhance mixing phenomena in microfluidic devices. Recent work has focused mostly on cases of super-hydrophobic stripes. Here, we analyze a relevant situation of cosine variation of the local slip length. We derive approximate formulae for maximal (longitudinal) and minimal (transverse) directional effective slip lengths that are in good agreement with the exact numerical solution and lattice-Bolzmann simulations for any surface slip fraction. The cosine texture can provide a very large effective (forward) slip, but it was found to be less efficient in generating a transverse flow as compared to super-hydrophobic stripes.

  14. Slip of polymer melts over micro/nano-patterned metallic surfaces.

    Science.gov (United States)

    Ebrahimi, Marzieh; Konaganti, Vinod Kumar; Moradi, Sona; Doufas, Antonios K; Hatzikiriakos, Savvas G

    2016-12-06

    The slip behavior of high-density polyethylenes (HDPEs) is studied over surfaces of different topology and surface energy. Laser ablation has been used to micro/nano-pattern the surface of dies in order to examine the effect of surface roughness on slip. In addition, fluoroalkyl silane-based coatings on smooth and patterned substrates were used to understand the effect of surface energy on slip. Surface roughness and surface energy effects were incorporated into the double reptation slip model (Ebrahimi et al., J. Rheol., 2015, 59, 885-901) in order to predict the slip velocity of studied polymers on different substrates. It was found that for dies with rough surfaces, polymer melt penetrates into the cavities of the substrate (depending on the depth and the distance between the asperities), thus decreasing wall slip. On the other hand, silanization of the surface increases the slip velocity of polymers in the case of smooth die, although it has a negligible effect on rough dies. Interestingly, the slip velocity of the studied polymers on various substrates of different degrees of roughness and surface energy, were brought into a mastercurve by modifying the double reptation slip velocity model.

  15. Evidence for 115 kilometers of right slip on the san gregorio-hosgri fault trend.

    Science.gov (United States)

    Graham, S A; Dickinson, W R

    1978-01-13

    The San Gregorio-Hosgri fault trend is a component of the San Andreas fault system on which there may have been about 115 kilometers of post-early Miocene right-lateral strike slip. If so, right slip on the San Andreas and San Gregorio-Hosgri faults accounts for most of the movement between the Pacific and North American plates since mid-Miocene time. Furthermore, the magnitude of right slip on a Paleogene proto-San Andreas fault inferred from the present distribution of granitic basement is reduced considerably when Neogene-Recent San Gregorio-Hosgri right slip is taken into account.

  16. Flow and heat transfer of nanofluid past stretching/shrinking sheet with partial slip boundary conditions

    Institute of Scientific and Technical Information of China (English)

    S MANSUR; A ISHAK; I POP

    2014-01-01

    The boundary layer flow of a nanofluid past a stretching/shrinking sheet with hydrodynamic and thermal slip boundary conditions is studied. Numerical solutions to the governing equations are obtained using a shooting method. The results are found for the skin friction coefficient, the local Nusselt number, and the local Sherwood number as well as the velocity, temperature, and concentration profiles for some values of the velocity slip parameter, thermal slip parameter, stretching/shrinking parameter, thermophoresis parameter, and Brownian motion parameter. The results show that the local Nusselt number, which represents the heat transfer rate, is lower for higher values of thermal slip parameter, thermophoresis parameter, and Brownian motion parameter.

  17. The phase slip factor of the electrostatic cryogenic storage ring CSR

    Science.gov (United States)

    Grieser, Manfred; von Hahn, Robert; Vogel, Stephen; Wolf, Andreas

    2017-07-01

    To determine the momentum spread of an ion beam from the measured revolution frequency distribution, the knowledge of the phase slip factor of the storage ring is necessary. The slip factor was measured for various working points of the cryogenic storage ring CSR at MPI for Nuclear Physics, Heidelberg and was compared with simulations. The predicted functional relationship of the slip factor and the horizontal tune depends on the different islands of stability, which has been experimentally verified. This behavior of the slip factor is in clear contrast to that of magnetic storage rings.

  18. Bond-slip behavior of CFRP plate-concrete interface

    Science.gov (United States)

    Cho, D. Y.; Park, S. K.; Hong, S. N.

    2011-11-01

    The paper deals with evaluation of the bond performance between a CFRP plate and concrete with respect to various compressive strengths of concrete and bond lengths of the CFRP plate as parameters. To consider stress conditions in the tensile zone of reinforced concrete (RC) structures, double-lap axial tension tests were conducted for eight specimens with CFRP plates bonded to concrete prisms. In addition, a simple linear bond-slip model for the CFRP plate/concrete joints, developed from the bond tests, was used. To verify the model proposed, a total of seven RC beams were strengthened with CFRP plates and tested in flexure employing various bond lengths, strengthening methods, and numbers of CFRP plates. A nonlinear finite-element analysis, with the bond-slip model incorporated in the DIANA program, was performed for the strengthened RC beams. Also, the results of flexural test and analytical predictions are found to be in close agreement in terms of yield and ultimate loads and ductility.

  19. Valgus Slipped Capital Femoral Epiphysis in Patient with Hypopituitarism

    Science.gov (United States)

    Fujiwara, Yasuhiro; Hayashida, Tatsuro; Murakami, Koji; Makio, Satoshi; Shimizu, Yuichi; Oka, Yoshinobu; Kim, Wook-Choel; Ogura, Taku; Kubo, Toshikazu

    2017-01-01

    Slipped capital femoral epiphysis (SCFE) is a common disease of adolescent and the epiphysis is positioned more posteromedially in relation to the femoral neck shaft with varus SCFE; however, posterolateral displacement of the capital epiphysis, valgus SCFE, occurs less frequently. We report a case of valgus SCFE in a 17-year-old boy with hypopituitarism. After falling down, he experienced difficulty in walking. The radiographs were inconclusive; however three-dimensional computed tomography images showed lateral displacement of the epiphysis on the right femoral head. Valgus SCFE was diagnosed. The patient underwent in situ pinning of both sides. In situ pinning on the left side was performed as a prophylactic pinning because of endocrine abnormalities. At the 1-year follow-up, he could walk without any difficulty and there were no signs of pain. The epiphysis is commonly positioned more posteromedially in relation to the femoral neck shaft with most SCFE, but, in this case, the epiphysis slipped laterally. Differential diagnosis included femoral neck fracture (Delbet-Colonna type 1); however, this was less likely due to the absence of other clinical signs. Therefore, we diagnosed the patient as SCFE. When children complain of leg pain and limp, valgus SCFE that may not be visualized on anteroposterior radiographs needs to be considered. PMID:28154765

  20. Valgus Slipped Capital Femoral Epiphysis in Patient with Hypopituitarism

    Directory of Open Access Journals (Sweden)

    Yoshihiro Kotoura

    2017-01-01

    Full Text Available Slipped capital femoral epiphysis (SCFE is a common disease of adolescent and the epiphysis is positioned more posteromedially in relation to the femoral neck shaft with varus SCFE; however, posterolateral displacement of the capital epiphysis, valgus SCFE, occurs less frequently. We report a case of valgus SCFE in a 17-year-old boy with hypopituitarism. After falling down, he experienced difficulty in walking. The radiographs were inconclusive; however three-dimensional computed tomography images showed lateral displacement of the epiphysis on the right femoral head. Valgus SCFE was diagnosed. The patient underwent in situ pinning of both sides. In situ pinning on the left side was performed as a prophylactic pinning because of endocrine abnormalities. At the 1-year follow-up, he could walk without any difficulty and there were no signs of pain. The epiphysis is commonly positioned more posteromedially in relation to the femoral neck shaft with most SCFE, but, in this case, the epiphysis slipped laterally. Differential diagnosis included femoral neck fracture (Delbet-Colonna type 1; however, this was less likely due to the absence of other clinical signs. Therefore, we diagnosed the patient as SCFE. When children complain of leg pain and limp, valgus SCFE that may not be visualized on anteroposterior radiographs needs to be considered.

  1. Episodic Tremor and Slip (ETS) as a chaotic multiphysics spring

    Science.gov (United States)

    Veveakis, E.; Alevizos, S.; Poulet, T.

    2017-03-01

    Episodic Tremor and Slip (ETS) events display a rich behaviour of slow and accelerated slip with simple oscillatory to complicated chaotic time series. It is commonly believed that the fast events appearing as non volcanic tremors are signatures of deep fluid injection. The fluid source is suggested to be related to the breakdown of hydrous phyllosilicates, mainly the serpentinite group minerals such as antigorite or lizardite that are widespread in the top of the slab in subduction environments. Similar ETS sequences are recorded in different lithologies in exhumed crustal carbonate-rich thrusts where the fluid source is suggested to be the more vigorous carbonate decomposition reaction. If indeed both types of events can be understood and modelled by the same generic fluid release reaction AB(solid) ⇌A(solid) +B(fluid) , the data from ETS sequences in subduction zones reveal a geophysically tractable temporal evolution with no access to the fault zone. This work reviews recent advances in modelling ETS events considering the multiphysics instabilities triggered by the fluid release reaction and develops a thermal-hydraulic-mechanical-chemical oscillator (THMC spring) model for such mineral reactions (like dehydration and decomposition) in Megathrusts. We describe advanced computational methods for THMC instabilities and discuss spectral element and finite element solutions. We apply the presented numerical methods to field examples of this important mechanism and reproduce the temporal signature of the Cascadia and Hikurangi trench with a serpentinite oscillator.

  2. Botulinum toxin treatment for slipping rib syndrome: a case report.

    Science.gov (United States)

    Pirali, Caterina; Santus, Gianna; Faletti, Sofia; De Grandis, Domenico

    2013-10-01

    Slipping rib syndrome (SRS) is a musculoskeletal cause of severe and recurrent thoracic or abdominal pain. The etiology of SRS is unknown, it seems to arise from costal hypermobility with a tendency of one of the ribs (usually from 8th to 10th but also 11th and 12th have been described) to slip under the superior adjacent rib. Its prevalence is underestimated because SRS is mainly a clinical diagnosis, frequently missed. The critical aspect of the diagnosis is knowledge of the condition itself, which, when lacking, often results in the patient being referred to many different specialists and exposed to unnecessary and costly investigations. The management of the condition includes conservative techniques such as manipulation, localized anesthetic, and steroid or anesthetic nerve block. However, where conservative therapy fails, surgical treatment, with excision of the rib, may be performed. In this paper we describe the case of a patient with persistent and debilitating flank pain who, after many investigations, was diagnosed with SRS. The usual conservative treatment failed, after which we treated the patient with injections of incobotulinumtoxin A into muscles inserting on the inferior side of the rib cage (quadratus lumborum muscle, muscle transversus abdomini, abdominal external oblique muscle, and recto abdomini) achieving a complete relief from pain. To our knowledge botulinum toxin has never been proposed before for the treatment of SRS. We believe that it should be considered as a therapeutic option, especially where other medical treatments have failed or as an intermediate step before surgical intervention.

  3. Nonstationary Stokes System in Cylindrical Domains Under Boundary Slip Conditions

    Science.gov (United States)

    Zaja¸czkowski, Wojciech M.

    2017-03-01

    Existence and uniqueness of solutions to the nonstationary Stokes system in a cylindrical domain {Ωsubset{R}^3} and under boundary slip conditions are proved in anisotropic Sobolev spaces. Assuming that the external force belong to {L_r(Ω×(0,T))} and initial velocity to {W_r^{2-2/r}(Ω)} there exists a solution such that velocity belongs to {W_r^{2,1}(Ω×(0,T))} and gradient of pressure to {L_r(Ω×(0,T))}, {rin(1,∞)}, {T > 0}. Thanks to the slip boundary conditions and a partition of unity the Stokes system is transformed to the Poisson equation for pressure and the heat equation for velocity. The existence of solutions to these equations is proved by applying local considerations. In this case we have to consider neighborhoods near the edges which by local mapping can be transformed to dihedral angle {π/2}. Hence solvability of the problem bases on construction local Green functions (near an interior point, near a point of a smooth part of the boundary, near a point of the edge) and their appropriate estimates. The technique presented in this paper can also work in other functional spaces: Sobolev-Slobodetskii, Besov, Nikolskii, Hölder and so on.

  4. Empirical slip and viscosity model performance for microscale gas flows.

    Energy Technology Data Exchange (ETDEWEB)

    Gallis, Michail A.; Boyd, Iain D. (University of Michigan, Ann Arbor, MI); McNenly, Matthew J. (University of Michigan, Ann Arbor, MI)

    2004-07-01

    For the simple geometries of Couette and Poiseuille flows, the velocity profile maintains a similar shape from continuum to free molecular flow. Therefore, modifications to the fluid viscosity and slip boundary conditions can improve the continuum based Navier-Stokes solution in the non-continuum non-equilibrium regime. In this investigation, the optimal modifications are found by a linear least-squares fit of the Navier-Stokes solution to the non-equilibrium solution obtained using the direct simulation Monte Carlo (DSMC) method. Models are then constructed for the Knudsen number dependence of the viscosity correction and the slip model from a database of DSMC solutions for Couette and Poiseuille flows of argon and nitrogen gas, with Knudsen numbers ranging from 0.01 to 10. Finally, the accuracy of the models is measured for non-equilibrium cases both in and outside the DSMC database. Flows outside the database include: combined Couette and Poiseuille flow, partial wall accommodation, helium gas, and non-zero convective acceleration. The models reproduce the velocity profiles in the DSMC database within an L{sub 2} error norm of 3% for Couette flows and 7% for Poiseuille flows. However, the errors in the model predictions outside the database are up to five times larger.

  5. Recent geodynamics of major strike-slip zones

    Directory of Open Access Journals (Sweden)

    Vladimir G. Trifonov

    2015-09-01

    In all of the cases mentioned above, strike-slip deformation was expressed only or mainly during strong earthquakes. At other times, the rate of its accumulation was small and the dominant stress conditions led to transverse shortening, rarely resulting in local lengthening of the tectonic zone. These variations are caused by the tectonic peculiarities of these zones. The sinistral component of the deformation is related to the shift of the Arabian Plate relative to the African one, but also the transverse component is related to the continental slope and is expressed by the Coastal range shortening that exists in the El Ghab segment zone. There is not only a dextral deformation component, but also a transverse component, expressed by shortening of the Fergana and Talas ranges existing in the Talas-Fergana fault zone. In both zones, the shortening component became appreciable or dominant when the strike-slip deformation rate decreased. Similar, but more local, relationships were expressed in the epicentral area of the 2003 Altai earthquake and in the Western Palmyrides.

  6. Constructing constitutive relationships for seismic and aseismic fault slip

    Science.gov (United States)

    Beeler, N.M.

    2009-01-01

    For the purpose of modeling natural fault slip, a useful result from an experimental fault mechanics study would be a physically-based constitutive relation that well characterizes all the relevant observations. This report describes an approach for constructing such equations. Where possible the construction intends to identify or, at least, attribute physical processes and contact scale physics to the observations such that the resulting relations can be extrapolated in conditions and scale between the laboratory and the Earth. The approach is developed as an alternative but is based on Ruina (1983) and is illustrated initially by constructing a couple of relations from that study. In addition, two example constitutive relationships are constructed; these describe laboratory observations not well-modeled by Ruina's equations: the unexpected shear-induced weakening of silica-rich rocks at high slip speed (Goldsby and Tullis, 2002) and fault strength in the brittle ductile transition zone (Shimamoto, 1986). The examples, provided as illustration, may also be useful for quantitative modeling.

  7. Seismic slip deficit in the Kashmir Himalaya from GPS observations

    Science.gov (United States)

    Schiffman, Celia; Bali, Bikram Singh; Szeliga, Walter; Bilham, Roger

    2013-11-01

    measurements in Kashmir Himalaya reveal range-normal convergence of 11 ± 1 mm/yr with dextral shear of 5 ± 1 mm/yr. The transition from a fully locked 170 km wide décollement to the unrestrained descending Indian plate occurs at ~25 km depth over an ~23 km wide transition zone. The convergence rate is consistent with the lower bounds of geological estimates for the Main Frontal Thrust, Riasi, and Balapora fault systems, on which no surface slip has been reported in the past millennium. Of the 14 damaging Kashmir earthquakes since 1123, none may have exceeded Mw = 7.6. Therefore, either a seismic moment deficit equivalent to a Mw ≈ 8.7 earthquake exists or the historical earthquake magnitudes have been underestimated. Alternatively, these earthquakes have occurred on reverse faults in the Kashmir Valley, and the décollement has been recently inactive. Although this can reconcile the inferred and theoretical moment release, it is quantitatively inconsistent with observed fault slip in Kashmir.

  8. An Analytical Tire Model with Flexible Carcass for Combined Slips

    Directory of Open Access Journals (Sweden)

    Nan Xu

    2014-01-01

    Full Text Available The tire mechanical characteristics under combined cornering and braking/driving situations have significant effects on vehicle directional controls. The objective of this paper is to present an analytical tire model with flexible carcass for combined slip situations, which can describe tire behavior well and can also be used for studying vehicle dynamics. The tire forces and moments come mainly from the shear stress and sliding friction at the tread-road interface. In order to describe complicated tire characteristics and tire-road friction, some key factors are considered in this model: arbitrary pressure distribution; translational, bending, and twisting compliance of the carcass; dynamic friction coefficient; anisotropic stiffness properties. The analytical tire model can describe tire forces and moments accurately under combined slip conditions. Some important properties induced by flexible carcass can also be reflected. The structural parameters of a tire can be identified from tire measurements and the computational results using the analytical model show good agreement with test data.

  9. The odontoid synchondrotic slip: an injury unique to young children

    Energy Technology Data Exchange (ETDEWEB)

    Connolly, B. [Dept. of Diagnostic Imaging, The Hospital for Sick Children, Univ. of Toronto, ON (Canada); Emery, D. [Dept. of Diagnostic Imaging, The Hospital for Sick Children, Univ. of Toronto, ON (Canada); Armstrong, D. [Dept. of Diagnostic Imaging, The Hospital for Sick Children, Univ. of Toronto, ON (Canada)

    1995-11-01

    We report seven children (three female, four male) diagnosed with traumatic synchrondrotic slip of the odontoid. The clinical records, plain films, and CT scans were evaluated retrospectively. The patients ranged in age between 3 and 5 years. Their injuries resulted from a motor vehicle accident in four cases and from a fall from a height in three. The injury was isolated in five; it was associated with a closed head injury in one and with facial and brachial plexus trauma in another. Radiographs showed anterior angulation with or without displacement in all seven cases. Axial CT with sagittal reformation and 3D reconstructions were performed in six cases. This confirmed the synchrondrotic slip and, in addition, identified a rotary component to the injury in three cases, with compromise of the canal in two. Other additional injuries were also noted. All cases were treated conservatively and the injuries healed. Only one child had a neurological deficit attributable to her head injury rather than to her cervical injury (MR of the cervical cord was normal). The presence of the synchondrosis between the dens and the body of C-2 makes this injury unique to children under 7 years of age; by the age of 7 the synchrondrosis has fused. (orig.)

  10. Stick-slip nanofriction in cold-ion traps

    Science.gov (United States)

    Mandelli, Davide; Vanossi, Andrea; Tosatti, Erio

    2013-03-01

    Trapped cold ions are known to form linear or planar zigzag chains, helices or clusters depending on trapping conditions. They may be forced to slide over a laser induced corrugated potential, a mimick of sliding friction. We present MD simulations of an incommensurate 101 ions chain sliding subject to an external electric field. As expected with increasing corrugation, we observe the transition from a smooth-sliding, highly lubric regime to a strongly dissipative stick-slip regime. Owing to inhomogeneity the dynamics shows features reminiscent of macroscopic frictional behaviors. While the chain extremities are pinned, the incommensurate central part is initially free to slide. The onset of global sliding is preceded by precursor events consisting of partial slips of chain portions further from the center. We also look for frictional anomalies expected for the chain sliding across the linear-zigzag structural phase transition. Although the chain is too short for a proper critical behavior, the sliding friction displays a frank rise near the transition, due to opening of a new dissipative channel via excitations of transverse modes. Research partly sponsored by Sinergia Project CRSII2 136287/1.

  11. Slip Validation and Prediction for Mars Exploration Rovers

    Directory of Open Access Journals (Sweden)

    Jeng Yen

    2008-04-01

    Full Text Available This paper presents a novel technique to validate and predict the rover slips on Martian surface for NASA’s Mars Exploration Rover mission (MER. Different from the traditional approach, the proposed method uses the actual velocity profile of the wheels and the digital elevation map (DEM from the stereo images of the terrain to formulate the equations of motion. The six wheel speed from the empirical encoder data comprises the vehicle's velocity, and the rover motion can be estimated using mixed differential and algebraic equations. Applying the discretization operator to these equations, the full kinematics state of the rover is then resolved by the configuration kinematics solution in the Rover Sequencing and Visualization Program (RSVP. This method, with the proper wheel slip and sliding factors, produces accurate simulation of the Mars Exploration rovers, which have been validated with the earth-testing vehicle. This computational technique has been deployed to the operation of the MER rovers in the extended mission period. Particularly, it yields high quality prediction of the rover motion on high slope areas. The simulated path of the rovers has been validated using the telemetry from the onboard Visual Odometry (VisOdom. Preliminary results indicate that the proposed simulation is very effective in planning the path of the rovers on the high-slope areas.

  12. Evaluation of the "Lose Your Excuse" public service advertising campaign for tweens to save energy.

    Science.gov (United States)

    Bertrand, Jane T; Goldman, Patty; Zhivan, Natalia; Agyeman, Yaw; Barber, Erin

    2011-10-01

    This study evaluates the 2008-2009 "Lose your Excuse" public service advertising (PSA) campaign on energy efficiency targeting 8- to 12-year-olds, intended to increase knowledge, foster proactive attitudes, and change energy usage behaviors. Baseline and two follow-up surveys were conducted with online samples representative of the national population of households with kids with online access. Almost half (47%) of the tweens recognized at least one ad from the campaign. Ad recognition was positively associated with knowledge, proactive attitudes, and energy-saving behavior. Propensity score analysis confirmed a small but measurable and statistically significant effect on energy-saving behavior. The discussion section compares these results to public health campaigns in terms of ghost awareness, reach, and effect size.

  13. A Simple Method for Labeling Human Embryonic Stem Cells Destined to Lose Undifferentiated Potency.

    Science.gov (United States)

    Kumagai, Ayako; Suga, Mika; Yanagihara, Kana; Itoh, Yumi; Takemori, Hiroshi; Furue, Miho K

    2016-03-01

    Mitochondrial oxidative phosphorylation is a major source of cellular ATP. Its usage as an energy source varies, not only according to the extracellular environment, but also during development and differentiation, as indicated by the reported changes in the flux ratio of glycolysis to oxidative phosphorylation during embryonic stem (ES) cell differentiation. The fluorescent probe JC-1 allows visualization of changes in the mitochondrial membrane potential produced by oxidative phosphorylation. Strong JC-1 signals were localized in the differentiated cells located at the edge of H9 ES colonies that expressed vimentin, an early differentiation maker. The JC-1 signals were further intensified when individual adjacent colonies were in contact with each other. Time-lapse analyses revealed that JC-1-labeled H9 cells under an overconfluent condition were highly differentiated after subculture, suggesting that monitoring oxidative phosphorylation in live cells might facilitate the prediction of induced pluripotent stem cells, as well as ES cells, that are destined to lose their undifferentiated potency.

  14. Stochastic Win-Stay-Lose-Shift with dynamic aspirations in evolutionary social dilemmas

    CERN Document Server

    Amaral, Marco A; Perc, Matjaz; da Silva, Jafferson K L

    2016-01-01

    In times of plenty expectations rise, just as in times of crisis they fall. This can be mathematically described as a Win-Stay-Lose-Shift strategy with dynamic aspiration levels, where individuals aspire to be as wealthy as their average neighbor. Here we investigate this model in the realm of evolutionary social dilemmas on the square lattice and scale-free networks. By using the master equation and Monte Carlo simulations, we find that cooperators coexist with defectors in the whole phase diagram, even at high temptations to defect. We study the microscopic mechanism that is responsible for the striking persistence of cooperative behavior and find that cooperation spreads through second-order neighbors, rather than by means of network reciprocity that dominates in imitation-based models. For the square lattice the master equation can be solved analytically in the large temperature limit of the Fermi function, while for other cases the resulting differential equations must be solved numerically. Either way, ...

  15. Lung Cancer Stem Cell Lose Their Stemness Default State after Exposure to Microgravity

    Directory of Open Access Journals (Sweden)

    Maria Elena Pisanu

    2014-01-01

    Full Text Available Microgravity influences cell differentiation by modifying the morphogenetic field in which stem cells are embedded. Preliminary data showed indeed that stem cells are committed to selective differentiation when exposed to real or simulated microgravity. Our study provides evidence that a similar event occurs when cancer stem cells (CSCs are cultured in microgravity. In the same time, a significant increase in apoptosis was recorded: those data point out that microgravity rescues CSCs from their relative quiescent state, inducing CSCs to lose their stemness features, as documented by the decrease in ALDH and the downregulation of both Nanog and Oct-4 genes. Those traits were stably acquired and preserved by CSCs when cells were placed again on a 1 g field. Studies conducted in microgravity on CSCs may improve our understanding of the fundamental role exerted by biophysical forces in cancer cell growth and function.

  16. Technical Skills Leading in Winning or Losing Volleyball Matches During Beijing Olympic Games

    Directory of Open Access Journals (Sweden)

    ASTERIOS PATSIAOURAS

    2011-06-01

    Full Text Available Volleyball is included in sports where individual success of final efforts such as a successful attack or aneffective block, is achieved by the harmonious collaboration of the preceded players’ efforts. The purpose of thispresent study was to evaluate the importance of technical skills that led to the success of the national teams thattook part in the Olympic Games of Beijing 2008. The sample was constituted by all the matches of the volleyballmen teams that participated in the Beijing Olympic Games. Overall, 29 games were videotaped and evaluated.Collection of data included the use of the statistical recording program Data Volley 2. The parameters that wereevaluated were: a service, b service reception, c attack, and d attack blocked. The statistical treatment of datawas realised through non parametric statistical analysis. The results showed that, service points, reception errors,and attacks blocked emerged as important factors that were decisive for wining or losing a match

  17. A pediatric non-protein losing Menetrier's disease successfully treated with octreotide long acting release

    Institute of Scientific and Technical Information of China (English)

    Giovanni Di Nardo; Salvatore Oliva; Marina Aloi; Federica Ferrari; Simone Frediani; Adriana Marcheggiano; Salvatore Cucchiara

    2012-01-01

    Pediatric Menetrier's disease (MD) is an uncommon,acute,self-limited hypertrophic gastropathy characterized by enlarged gastric folds associated with epithelial hyperplasia and usually accompanied by protein losing gastropathy.Gastric cytomegalovirus infection is found in one third of MD children and its treatment is often associated with remission.Diagnosis often requires fullthickness biopsy due to inability to detect typical histological findings with conventional endoscopic biopsy.We report an uncommon case of non self-limited pediatric MD needing endoscopic mucosal resection for diagnosis which was then successfully treated with octreotide long-acting release (LAR).To the best of our knowledge,this is the first pediatric MD case successfully treated with octreotide LAR.Our experience suggests octreotide LAR as treatment for refractory MD before gastrectomy.

  18. Application of integral pumping tests to investigate the influence of a losing stream on groundwater quality

    Directory of Open Access Journals (Sweden)

    S. Leschik

    2009-06-01

    Full Text Available Losing streams that are influenced by wastewater treatment plant effluents and combined sewer overflows (CSO's can be a source of groundwater contamination. Released micropollutants such as pharmaceuticals, endocrine disrupters and other ecotoxicologically relevant substances as well as inorganic wastewater constituents can reach the groundwater, where they may deteriorate groundwater quality. This paper presents a method to quantify exfiltration mass flow rates Mex of wastewater constituents from losing streams by the operation of integral pumping tests (IPT's up- and downstream of a target section. Due to the large sampled water volume during IPT's the results are more reliable than those from conventional point sampling. We applied the method at a test site in Leipzig (Germany. Wastewater constituents K+ and NO3 showed Mex values of 1241 to 4315 and 749 to 924 mg m−1stream d−1, respectively, while Cl (16.8 to 47.3 g m−1stream d−1 and SO42− (20.3 to 32.2 g m−1stream d−1 revealed the highest observed Mex values at the test site. The micropollutants caffeine and technical-nonylphenol were dominated by elimination processes in the groundwater between upstream and downstream wells. Additional concentration measurements in the stream and a connected sewer at the test site were performed to identify relevant processes that influence the concentrations at the IPT wells.

  19. Application of integral pumping tests to investigate the influence of a losing stream on groundwater quality

    Directory of Open Access Journals (Sweden)

    S. Leschik

    2009-10-01

    Full Text Available Losing streams that are influenced by wastewater treatment plant effluents and combined sewer overflows (CSOs can be a source of groundwater contamination. Released micropollutants such as pharmaceuticals, endocrine disrupters and other ecotoxicologically relevant substances as well as inorganic wastewater constituents can reach the groundwater, where they may deteriorate groundwater quality. This paper presents a method to quantify exfiltration mass flow rates per stream length unit Mex of wastewater constituents from losing streams by the operation of integral pumping tests (IPTs up- and downstream of a target section. Due to the large sampled water volume during IPTs the results are more reliable than those from conventional point sampling. We applied the method at a test site in Leipzig (Germany. Wastewater constituents K+ and NO3 showed Mex values of 1241 to 4315 and 749 to 924 mg mstream−1 d−1, respectively, while Cl (16.8 to 47.3 g mstream−1 d−1 and SO42− (20.3 to 32.2 g mstream−1 d−1 revealed the highest observed Mex values at the test site. The micropollutants caffeine and technical-nonylphenol were dominated by elimination processes in the groundwater between upstream and downstream wells. Additional concentration measurements in the stream and a connected sewer at the test site were performed to identify relevant processes that influence the concentrations at the IPT wells.

  20. A balanced team generating model

    NARCIS (Netherlands)

    van de Water, Tara; van de Water, Henny; Bukman, Cock

    2007-01-01

    This paper introduces a general team balancing model. It first summarizes existing balancing methods. It is shown that for these methods it is difficult to meet all the conditions posed by Belbin on balanced teams. This mainly is caused by the complexity of the balancing problem. A mathematical mode

  1. Fleksibilitet og balance

    OpenAIRE

    2014-01-01

    Fleksibilitet og balance Dette projekt undersøger, hvordan arbejdstidsmæssig fleksibilitet påvirker medarbejderens individuelle balance mellem arbejde og privatliv, og om en ændring af dennes mindset kan forbedre balancen. Centralt i projektet er en afdækning af fordele og ulemper ved den arbejdstidsmæssige fleksibilitet. I forlængelse heraf er det interessant, hvordan disse fordele og ulemper påvirker balancen mellem arbejde og privatliv. Ydermere er det interessant om den enkelte medarb...

  2. Finding Your Balance

    CERN Document Server

    (CCL), Center for Creative Leadership; Patterson, Gordon

    2011-01-01

    Balance isn't an issue of time, but an issue of choice. It's about living your values by aligning your behavior with what you believe is really important. Aligning your behavior with your values is much like any other developmental experience; the basic process involves assessment, challenge, and support. You need to determine where you are, define where you want to go, and then put into place the tools you need to get there.Balance is about more than how you spend your time. It's about how you live your life. It's about recognizing that you have control over the choices you make and aligning

  3. Rotary and Magnus balances

    Science.gov (United States)

    Malcolm, G. N.

    1981-01-01

    Two wind tunnel techniques for determining part of the aerodynamic information required to describe the dynamic bahavior of various types of vehicles in flight are described. Force and moment measurements are determined with a rotary-balance apparatus in a coning motion and with a Magnus balance in a high-speed spinning motion. Coning motion is pertinent to both aircraft and missiles, and spinning is important for spin stabilized missiles. Basic principles of both techniques are described, and specific examples of each type of apparatus are presented. Typical experimental results are also discussed.

  4. Application of Balanced Scorecard

    OpenAIRE

    Langpaulová, Irena

    2011-01-01

    The concept of the Balanced Scorecard taking a part in the strategic management of a company, is a main focus of this thesis. There are the theoretical and methodological parts of the Balanced Scorecard characterized individually, as well as the development and the history of this concept. This thesis is dealing with a draft of the practical implementation of the mentioned methods. The practical part of the thesis is following the theoretical introduction where the practical part is focused o...

  5. Yin-Yang Balancing

    DEFF Research Database (Denmark)

    Li, Peter Ping

    The potential contribution of the Eastern frame of Yin-Yang Balancing lies in the mindset of "either/and", in contrast to Aristotle's either/or logic and Hegel's "both/or". Implications of this either/and thinking for science and management will be explored.......The potential contribution of the Eastern frame of Yin-Yang Balancing lies in the mindset of "either/and", in contrast to Aristotle's either/or logic and Hegel's "both/or". Implications of this either/and thinking for science and management will be explored....

  6. Dynamic rupture simulation with an experimentally-determined friction law leads to slip-pulse propagation

    Science.gov (United States)

    Liao, Z.; Chang, J. C.; Reches, Z.

    2013-12-01

    We simulate the dynamic rupture along a vertical, strike-slip fault in an elastic half-space. The fault has frictional properties that were determined in high-velocity, rotary shear apparatus Sierra-White granite. The experimental fault was abruptly loaded by a massive flywheel, which is assumed to simulate the loading of a fault patch during an earthquake, and termed Earthquake-Like-Slip Event (ELSE) (Chang et al., 2012). The experiments revealed systematic alteration between slip-weakening and slip-strengthening (Fig. 1A), and were considered as proxies of fault-patch behavior during earthquakes of M = 4-8. We used the friction-distance relations of these experiments to form an empirical slip-dependent friction model, ELSE-model (Fig. 1B). For the dynamic rupture simulation, we used the program of Ampuero (2002) (2D spectral boundary integral elements) designed for anti-plane (mode III) shear fracturing. To compare with published works, the calculations used a crust with mechanical properties and stress state of Version 3 benchmark of SCEC (Harris et al., 2004). The calculations with a fault of ELSE-model friction revealed: (1) Rupture propagation in a slip-pulse style with slip cessation behind the pulse; (2) Systematic decrease of slip distance away from the nucleation zone; and (3) Spontaneous arrest of the dynamic rupture without a barrier. These features suggest a rupture of a self-healing slip-pulse mode (Fig. 1C), in contrast to rupturing of a fault with linear slip-weakening friction (Fig. 1B) (Rojas et al., 2008) in crack-like mode and no spontaneous arrest. We deduce that the slip-pulse in our simulation results from the fast recovery of shear strength as observed in ELSE experiments, and argue that incorporating this experimentally-based friction model to rupture modeling produces realistic propagation style of earthquake rupture. Figure 1 Fault patch behavior during an earthquake. (A) Experimental evolution of frictional stress, slip velocity, and

  7. Predicting the probability of slip in gait: methodology and distribution study.

    Science.gov (United States)

    Gragg, Jared; Yang, James

    2016-01-01

    The likelihood of a slip is related to the available and required friction for a certain activity, here gait. Classical slip and fall analysis presumed that a walking surface was safe if the difference between the mean available and required friction coefficients exceeded a certain threshold. Previous research was dedicated to reformulating the classical slip and fall theory to include the stochastic variation of the available and required friction when predicting the probability of slip in gait. However, when predicting the probability of a slip, previous researchers have either ignored the variation in the required friction or assumed the available and required friction to be normally distributed. Also, there are no published results that actually give the probability of slip for various combinations of required and available frictions. This study proposes a modification to the equation for predicting the probability of slip, reducing the previous equation from a double-integral to a more convenient single-integral form. Also, a simple numerical integration technique is provided to predict the probability of slip in gait: the trapezoidal method. The effect of the random variable distributions on the probability of slip is also studied. It is shown that both the required and available friction distributions cannot automatically be assumed as being normally distributed. The proposed methods allow for any combination of distributions for the available and required friction, and numerical results are compared to analytical solutions for an error analysis. The trapezoidal method is shown to be highly accurate and efficient. The probability of slip is also shown to be sensitive to the input distributions of the required and available friction. Lastly, a critical value for the probability of slip is proposed based on the number of steps taken by an average person in a single day.

  8. The Effects on Tsunami Hazard Assessment in Chile of Assuming Earthquake Scenarios with Spatially Uniform Slip

    Science.gov (United States)

    Carvajal, Matías; Gubler, Alejandra

    2016-12-01

    We investigated the effect that along-dip slip distribution has on the near-shore tsunami amplitudes and on coastal land-level changes in the region of central Chile (29°-37°S). Here and all along the Chilean megathrust, the seismogenic zone extends beneath dry land, and thus, tsunami generation and propagation is limited to its seaward portion, where the sensitivity of the initial tsunami waveform to dislocation model inputs, such as slip distribution, is greater. We considered four distributions of earthquake slip in the dip direction, including a spatially uniform slip source and three others with typical bell-shaped slip patterns that differ in the depth range of slip concentration. We found that a uniform slip scenario predicts much lower tsunami amplitudes and generally less coastal subsidence than scenarios that assume bell-shaped distributions of slip. Although the finding that uniform slip scenarios underestimate tsunami amplitudes is not new, it has been largely ignored for tsunami hazard assessment in Chile. Our simulations results also suggest that uniform slip scenarios tend to predict later arrival times of the leading wave than bell-shaped sources. The time occurrence of the largest wave at a specific site is also dependent on how the slip is distributed in the dip direction; however, other factors, such as local bathymetric configurations and standing edge waves, are also expected to play a role. Arrival time differences are especially critical in Chile, where tsunamis arrive earlier than elsewhere. We believe that the results of this study will be useful to both public and private organizations for mapping tsunami hazard in coastal areas along the Chilean coast, and, therefore, help reduce the risk of loss and damage caused by future tsunamis.

  9. Fuzzy anti-slip control based on optimal slip control%基于最优滑转率的电动车辆驱动防滑控制策略

    Institute of Scientific and Technical Information of China (English)

    冯彦彪; 杨珏; 季智燚; 张文明

    2015-01-01

    to the wheel is increasing or decreasing correspondingly. So the driving torque on wheel can be balanced with the resistance torque on wheel, which means the truck can operated at a steady state. The fuzzy control system adjusts the torque distribution of the wheel-motors to maintain the optimal slip rate. The system is modeled with Matlab/Simulink software. Using this model, serial tests are simulated on various terrains including the road with low attachment coefficient, the bisectional road and the joint road. In the road with low attachment coefficient, the slip rate without control is very high that can reach 1, which means the wheel is rotating but truck wouldn’t move. After applying the control, the slip rate can stabilize at a given reference value. Meanwhile, the attachment coefficient can be controlled at an optimal level. In the bisectional road, the slip rate is ideal when the truck’s wheel is at the side of the road with high attachment coefficient;but when the truck moves into the road with low attachment coefficient, the slip rate sharply increases. At this moment, the truck can’t ensure the direction of stability. So the danger coefficient is high. But the slip rate with control is stabilized at a given value. The result shows that the fuzzy control system can raise the utilization attachment coefficient and improve the power, stability and safety. Finally, to verify the controller’s feasibility and calculation efficiency, the hardware-in-loop (HIL) simulation system is implemented. The national instrument (NI) embedded system is used. The truck’s model that includes the dynamic model and the AC motor’s control model is operated in PXI8110. And the control algorithm is running in CompactRIO-9024 which is an excellent controller to simulate the real-time situation. All the simulation operations are run again in the HIL system, and the road with low attachment coefficient, the bisectional road and the joint road are included. In the HIL

  10. A point-by-point analysis of performance in a fencing match: psychological processes associated with winning and losing streaks.

    Science.gov (United States)

    Doron, Julie; Gaudreau, Patrick

    2014-02-01

    This study aimed to revisit the complex nature of serial dependency of performance during a match, examining the prospective associations between psychological processes and subsequent performance at the within-person level of analysis, and explore whether psychological processes are associated with the likelihood of winning series of points. A process-oriented sequential approach was used with 16 elite fencers during a simulated competition. Multilevel regression analyses revealed that serial dependency of performance fluctuates within a match. Results of a Bayesian multilevel structural equation model showed that prior performance subsequently influenced psychological processes. Although psychological processes did not predict performance in the subsequent point, successive winnings were associated with higher perceived control and task-oriented coping and lower negative affectivity compared with both losing streaks and nonstreaks. Overall, serial dependencies of performance are nonstationary during a match whereas psychological processes significantly differ in episodes of winning after winning versus losing after losing.

  11. Characteristics and habitat of deep vs. shallow slow slip events

    Science.gov (United States)

    Wallace, L. M.; Saffer, D. M.

    2016-12-01

    It is well-known that slow slip events (SSEs) occur over a large depths range at subduction zones, from near the trench to 40-50 km depth. We review the characteristics and in situ conditions of shallow vs. deep SSEs, including duration, magnitude, seismic signatures, and inferences about the rock properties and stress state in their source regions. Deep SSEs (>15 km depth) exhibit a range of durations (days to years), while shallow SSEs (Mexico, Cascadia), although shallow SSEs offshore Costa Rica and Nankai have also been linked to tremor and/or very low frequency earthquakes. Shallow SSEs in central Japan (Boso), Hikurangi, and Ecuador are associated with bursts of microseismicity. Deep SSEs occur at the inferred down-dip limit of the locked seismogenic zone, whereas many shallow SSEs occur at mostly creeping plate boundaries (Hikurangi, Ecuador), or updip of the seismogenic zone (Nankai, Costa Rica). Despite the differences, there are many similarities between deep and shallow SSEs, suggesting that common physical mechanisms may be responsible for slow slip in these vastly different environments. Deep and shallow SSEs span a range of temperature and pressure conditions, implying that the physical conditions hosting SSEs are broad. Seismic imaging of shallow and deep SSE regions indicate likely fluid overpressure, supporting the idea that low effective normal stress may be a common factor promoting SSE behavior. High fluid pressure in shallow SSE zones is largely from disequilibrium compaction of low permeability marine sediments, while fluids in deep SSE regions are likely sourced from metamorphic dehydration reactions. That all shallow SSEs observed thus far are shorter in duration than many deep SSEs may be due to a number of factors, including higher effective stress on the plate boundary in deep vs. shallow regions, and differing degrees of subduction interface heterogeneity. Tremor vs. microseismicity may be related to the scale and distribution of

  12. In the balance

    DEFF Research Database (Denmark)

    Kluth, Michael Friederich; Pilegaard, Jess

    The present paper seeks to make sense of recent EU naval capability changes by applying neo-realist theory on the EU as an international actor in the global balance of power. The paper compares three different strands of Neo-realist theory by deducting key predictions about the expected defense...

  13. Balancing beyond the horizon?

    DEFF Research Database (Denmark)

    Kluth, Michael Friederich; Pilegaard, Jess

    2011-01-01

    The present article seeks to make sense of recent European Union (EU) naval capability changes by applying neo-realist theory to the EU as a collective actor in the global balance of power. The paper compares two different strands of neorealist theory by deducing key predictions about the expecte...

  14. Ballet Balance Strategies

    DEFF Research Database (Denmark)

    Pedersen, Camilla; Erleben, Kenny; Sporring, Jon

    2006-01-01

    Animating physically realistic human characters is challenging, since human observers are highly tuned to recognize human cues such as emotion and gender from motion patterns. The main contribution of this paper is a new model firmly based on biomechanics, which is used to animate balance and basic...

  15. Frihed, anerkendelse og balance

    DEFF Research Database (Denmark)

    Anker, Thomas Boysen

    2008-01-01

    Artiklen argumenterer for, at selv ikke den absolut mest familievenlige arbejdsplads vil kunne løse det psykologiske problem med at skabe balance mellem familie og arbejdsliv, fordi ubalancen grundlæggende handler om en anerkendelseskonflikt, som individet ikke altid selv er interesseret i at komme...

  16. Strategic Balanced Scorecard Simulation

    DEFF Research Database (Denmark)

    Nielsen, Steen; Nielsen, Erland Hejn

    2012-01-01

    The purpose of this article is to show how a System Dynamics Modelling approach can be integrated into the Balanced Scorecard (BSC) for a case company with special focus on the handling of causality in a dynamic perspective. The case company’s BSC model includes five perspectives and a number...

  17. Win-stay-lose-learn promotes cooperation in the prisoner’s dilemma game with voluntary participation

    Science.gov (United States)

    Chu, Chen; Liu, Jinzhuo; Shen, Chen; Jin, Jiahua; Shi, Lei

    2017-01-01

    Voluntary participation, demonstrated to be a simple yet effective mechanism to promote persistent cooperative behavior, has been extensively studied. It has also been verified that the aspiration-based win-stay-lose-learn strategy updating rule promotes the evolution of cooperation. Inspired by this well-known fact, we combine the Win-Stay-Lose-Learn updating rule with voluntary participation: Players maintain their strategies when they are satisfied, or players attempt to imitate the strategy of one randomly chosen neighbor. We find that this mechanism maintains persistent cooperative behavior, even further promotes the evolution of cooperation under certain conditions. PMID:28182707

  18. Approximate solutions of the equation of motion’s of the rigid rod which rocks on the circular surface without slipping

    Directory of Open Access Journals (Sweden)

    Md. Alal Hosen

    2014-09-01

    Full Text Available In this paper, a modified harmonic balance method based an analytical technique has been developed to determine approximate solutions for a strongly nonlinear oscillator with a discontinuous term which is arising from the motion of rigid rod on the surface without slipping. Usually, a set of nonlinear algebraic equations is solved in this method. However, analytical solutions of these algebraic equations are not always possible, especially in the case of a large oscillation. We have been compared the solution results of this method with the numerical solution in order to validate the approach and assess the accuracy of the solutions has been demonstrated and discussed. We found that, a second order modified harmonic balance method works very well for the whole range of initial amplitudes. The advantage of the using method is its simple procedure and gives almost similar results in comparison with the exact solution.

  19. The Graetz–Nusselt problem extended to continuum flows with finite slip

    NARCIS (Netherlands)

    Haase, A. Sander; Chapman, S. Jonathan; Tsai, Peichun Amy; Lohse, Detlef; Lammertink, Rob G.H.

    2015-01-01

    Graetz and Nusselt studied heat transfer between a developed laminar fluid flow and a tube at constant wall temperature. Here, we extend the Graetz–Nusselt problem to dense fluid flows with partial wall slip. Its limits correspond to the classical problems for no-slip and no-shear flow. The amount o

  20. 33 CFR 165.751 - Security Zone: LNG mooring slip, Savannah River, Savannah, Georgia.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Security Zone: LNG mooring slip... § 165.751 Security Zone: LNG mooring slip, Savannah River, Savannah, Georgia. (a) Security zone. The... security zone; or (4) Actively engaged in escort, maneuvering, or support duties for an LNG tankship....

  1. Investigation of active slip systems in high purity single crystal niobium

    Science.gov (United States)

    Baars, Derek

    The superconducting radio-frequency (SRF) community uses high purity niobium to manufacture SRF cavities for a variety of accelerator applications. Cavities are either made from large-grain sheets cut directly from the ingot and formed, or the ingot microstructure is broken down to form polycrystalline sheets or tubes. Reducing the number of costly electron beam welds to assemble the cavities is also desired. A greater understanding of the active slip systems and their relation to subsequent dislocation substructure would be of use in all these areas, to better understand how large grain niobium deforms and to develop more accurate computational models that will aid in the design and use of more cost-effective forming methods. Studies of slip in high-purity niobium suggest that temperature, material purity, and crystal orientation affect which slip systems are active during deformation, though have not examined the somewhat lesser purity niobium used for SRF cavities. As a step toward these goals, two sets of SRF-purity single crystal niobium samples were deformed to 40% strain in tension at room temperature. The first set was cut and welded back together. The second set consisted of deliberately orientated samples that resolved shear stress onto desired slip systems to evaluate different combinations of slip. Determining likely active slip systems was complex, though the evidence suggests that {112} slip may be dominant at yield at room temperature as suggested by theory, though {110} slip could not be ruled out.

  2. Slip Torque Investigation and Magnetic Redesign of Motor Integrated Permanent Magnet Gear

    DEFF Research Database (Denmark)

    Frandsen, Tommy Vestergaard; Rasmussen, Peter Omand

    2015-01-01

    This paper presents an investigation of 20% difference between the measured and calculated slip torque of a Motor Integrated Permanent Magnet Gear (MIPMG) prototype. The High Speed (HS) side of the Magnetic Gear (MG) was fixed by loading the motor when conducting the slip torque measurement...

  3. Do faults preserve a record of seismic slip: A second opinion

    Science.gov (United States)

    Rowe, Christie D.; Griffith, W. Ashley

    2015-09-01

    Exhumed fault zones offer insights into deformation processes associated with earthquakes in unparalleled spatial resolution; however it can be difficult to differentiate seismic slip from slow or aseismic slip based on evidence in the rock record. Fifteen years ago, Cowan (1999) defined the attributes of earthquake slip that might be preserved in the rock record, and he identified pseudotachylyte as the only reliable indicator of past earthquakes found in ancient faults. This assertion was based on models of frictional heat production (Sibson, 1975, 1986) providing evidence for fast slip. Significant progress in fault rock studies has revealed a range of reaction products which can be used to detect frictional heating at peak temperatures less than the melt temperature of the rock. In addition, features formed under extreme transient stress conditions associated with the propagating tip of an earthquake rupture can now be recognized in the rock record, and are also uniquely seismic. Thus, pseudotachylyte is no longer the only indicator of fossilized earthquake ruptures. We review the criteria for seismic slip defined by Cowan (1999), and we determine that they are too narrow. Fault slip at rates in the range 10-4-101 m/s is almost certainly dynamic. This implies that features reproduced in experiments at rates as low as 10-4 m/s may be indicators of seismic slip. We conclude with a summary of the rock record of seismic slip, and lay out the current challenges in the field of earthquake geology.

  4. Apparent slip of shear thinning fluid in a microchannel with a superhydrophobic wall

    Science.gov (United States)

    Patlazhan, Stanislav; Vagner, Sergei

    2017-07-01

    The peculiarities of simple shear flow of shear thinning fluids over a superhydrophobic wall consisting of a set of parallel gas-filled grooves and solid stripes (domains with slip and stick boundary conditions) are studied numerically. The Carreau-Yasuda model is used to provide further insight into the problem of the slip behavior of non-Newtonian fluids having a decreasing viscosity with a shear rate increase. This feature is demonstrated to cause a nonlinear velocity profile leading to the apparent slip. The corresponding transverse and longitudinal apparent slip lengths of a striped texture are found to be noticeably larger than the respective effective slip lengths of Newtonian liquids in microchannels of various thicknesses and surface fractions of the slip domains. The viscosity distribution of the shear thinning fluid over the superhydrophobic wall is carefully investigated to describe the mechanism of the apparent slip. Nonmonotonic behavior of the apparent slip length as a function of the applied shear rate is revealed. This important property of shear thinning fluids is considered to be sensitive to the steepness of the viscosity flow curve, thus providing a way to decrease considerably the flow resistance in microchannels.

  5. QUARRY STABILITY ANALYSIS FOR COMPLEX SLIP SURFACES USING THE MATHSLOPE METHOD

    Directory of Open Access Journals (Sweden)

    Petar Hrženjak

    2004-12-01

    Full Text Available Due to the specific characteristics of rock mass compared to other geological materials, the calculation of rock slope stability is very complex. One of the basic characteristics of rock masses is discontinuity, which, to the most degree, is formed by the geological structure and its elements. Because of discontinuities the slip surfaces of complex shapes are formed in rock slopes, mostly of straight and curved segments. The calculation of the stability factor of rock slopes for complex shapes of slip surfaces has been made possible by the development of the MathSlope method. The complex shape of slip surface has been achieved by introduction of planes of discontinuities in the slip surface. Thus, the setting up and searching procedure of critical slip surfaces of complex shapes is very different in the MathSlope method than in other ones. The example of back analysis for the quarry Vukov Dol shows the successfulness in determining the critical slip surface, as well as the calculation factor of stability for the complex shape of slip surface. Apart from calculating the factor of stability for the complex slip surface, the solution for the position of discontinuity on the slope is obtained, which matches with the real position on the quarry.

  6. On a credit oscillatory system with the inclusion of stick-slip

    Directory of Open Access Journals (Sweden)

    Parovik Roman

    2016-01-01

    Full Text Available The work was a mathematical model that describes the effect of the sliding attachment (stick-slip, taking into account hereditarity. This model can be regarded as a mechanical model of earthquake preparation. For such a model was proposed explicit finite- difference scheme, on which were built the waveform and phase trajectories hereditarity effect of stick-slip.

  7. Aseismic slip on the San Andreas Fault south of Loma Prieta

    Science.gov (United States)

    Behr, J.; Bilham, R.; Bodin, P.; Burfoid, R. O.; Bürgmann, R.

    Two digital creepmeters installed within the San Andreas fault zone after the 18 Oct 1989 Loma Prieta main shock show less than 1 cm of post seismic right-lateral slip in the four months following the earthquake. At Mt. Madonna road a 23 mm coseismic fracture slipped a further 3 mm after heavy rain, and at Nyland Ranch near San Juan Bautista the fault slipped approximately 9 mm starting 42 days after the main shock. If the current trend at Nyland Ranch persists, more than 2 cm of post seismic slip will develop by 1991. At both sites minor left-lateral displacements occurred which are attributed to near-surface soil effects. The abutments of the railroad bridge across the Pajaro River at Chittenden, which were extended by the 1906 earthquake, were not extended during the Loma Prieta event although they have evidently moved apart by more than 7 cm since bridge reconstruction in 1940. This corresponds to 10 cm of right-lateral slip which could be related to M>5 events in mid-century or could be due to aseismic slip at a mean rate of 2.1 mm/a. The absence of significant surface slip within the fault zone in the decades before and the months following the Loma Prieta event suggests either that near-surface deformation is distributed over a wide zone or that a slip deficit remains. Several authors have proposed this region as a future location for M≈5 events.

  8. The transition from strike slip to oblique subduction in southeastern Alaska from seismological studies

    Science.gov (United States)

    Doser, Diane I.; Lomas, Rodolfo

    2000-01-01

    Body waveform modeling of 11 moderate to large earthquakes within southeastern Alaska has been incorporated with earthquake relocations and the results of previous seismicity studies to examine the transition from strike-slip to oblique subduction in southeastern Alaska. In the Sitka region of extreme southeastern Alaska, earthquakes indicate seismic slip is parallel to the direction of motion between North America and the Pacific plate. As the plate margin begins to bend to the west near Cross Sound and encounters the southeastern edge of the Yakutat Block, partitioning of seismic slip is evident both onshore and offshore. Although the largest earthquakes (magnitude>6.0) in this region have slip parallel to plate motion, most moderate sized events have slip vectors rotated clockwise from plate motion. Offshore, the 1973 Cross Sound sequence indicates that the southern end of the Transition zone is seismogenic, with the Pacific plate being thrust beneath the Yakutat block, while onshore, strike-slip faulting has occurred along the Fairweather, Border Ranges and Denali faults. In the St. Elias region, thrust faulting is occurring along and above the plate interface. Moderate sized events in the St. Elias show a mix of slip vector orientations. In the Pamplona zone slip vectors of offshore earthquakes and deformation directions determined onshore from GPS studies show a counter-clockwise rotation relative to plate motion, suggesting that a change in strain field occurs just west of the St. Elias region.

  9. "A Chance Child": Jill Paton Walsh and the Re-Invention of the Time Slip Story

    Science.gov (United States)

    Hall, Linda Marian

    2011-01-01

    In this study of Jill Paton Walsh's one time-slip novel, I attempt to show how she reinvents the genre by giving as much prominence to the dislocated present as she does to the sufferings of children caught up in the horrors of the Industrial Revolution. Where previous time-slip authors had concentrated on the past, she addresses clearly unwelcome…

  10. Effects of multi-joint muscular fatigue on biomechanics of slips.

    Science.gov (United States)

    Lew, Fui Ling; Qu, Xingda

    2014-01-03

    The objective of the present study was to investigate the effects of multi-joint muscular fatigue on biomechanics of slips. Both lower-limb fatigue and upper-limb fatigue were examined, and the fatiguing exercises involved multi-joint movements to replicate muscular fatigue in realistic scenarios. Sixty healthy young adults participated in the study, and were evenly categorized into three groups: no fatigue, lower-limb fatigue, and upper-limb fatigue. These participants were instructed to walk on a linear walkway, and slips were induced unexpectedly during walking. The results showed that multi-joint muscular fatigue affects biomechanics of slips in all three phases of slips (i.e. initiation, detection, and recovery). In particular, adaptive safer postural control strategies were adopted with the application of both lower-limb fatigue and upper-limb fatigue to maintain the likelihood of slip initiation as in the no fatigue condition. In the phases of detection and recovery, lower-limb fatigue was found to compromise biomechanics of slips while upper-limb fatigue did not show any effects. Based on these findings, minimizing exposures to lower-limb fatigue should be given higher priority compared to upper-limb fatigue when developing interventions to prevent slip-induced falls. In addition, these findings also suggest that interventions aimed at enhancing proprioceptive acuity and increasing muscular strength in the lower limb could also be effective in slip-induced fall prevention.

  11. Incompressible viscous flow near the leading edge of a flat plate admitting slip

    NARCIS (Netherlands)

    Vooren, A.I. van de; Veldman, A.E.P.

    1975-01-01

    The shear stress at the leading edge, calculated on basis of the Navier-Stokes equations and the no-slip boundary condition, approaches infinity. However, taking into account the mean free path of the molecules, which implies admitting a certain slip, the shear stress becomes inversely proportional

  12. A 2D analytical multiple slip model for continuum texture development and plastic spin

    NARCIS (Netherlands)

    Giessen, E. van der; Houtte, P. van

    1992-01-01

    A two-dimensional continuum slip model is presented which accounts in an approximate way for texture development in polycrystalline metals during large strain plastic deformations. The basic kinematic model is that of a rigid-plastic laminated material deforming predominantly by slip along its conta

  13. "A Chance Child": Jill Paton Walsh and the Re-Invention of the Time Slip Story

    Science.gov (United States)

    Hall, Linda Marian

    2011-01-01

    In this study of Jill Paton Walsh's one time-slip novel, I attempt to show how she reinvents the genre by giving as much prominence to the dislocated present as she does to the sufferings of children caught up in the horrors of the Industrial Revolution. Where previous time-slip authors had concentrated on the past, she addresses clearly unwelcome…

  14. Slipping motion of large neutrally-buoyant particles in turbulence

    CERN Document Server

    Cisse, Mamadou; Bec, Jeremie

    2013-01-01

    Direct numerical simulations are used to investigate the individual dynamics of large spherical particles suspended in a developed homogeneous turbulent flow. A definition of the direction of the particle motion relative to the surrounding flow is introduced and used to construct the mean fluid velocity profile around the particle. This leads to an estimate of the particle slipping velocity and its associated Reynolds number. The flow modifications due to the particle are then studied. The particle is responsible for a shadowing effect that occurs in the wake up to distances of the order of its diameter: the particle pacifies turbulent fluctuations and reduces the energy dissipation rate compared to its average value in the bulk. Dimensional arguments are presented to draw an analogy between particle effects on turbulence and wall flows. Evidence is obtained on the presence of a logarithmic sublayer at distances between the thickness of the viscous boundary layer and the particle diameter $\\Dp$. Finally, asym...

  15. NONLINEAR ESTIMATION METHODS FOR AUTONOMOUS TRACKED VEHICLE WITH SLIP

    Institute of Scientific and Technical Information of China (English)

    ZHOU Bo; HAN Jianda

    2007-01-01

    In order to achieve precise, robust autonomous guidance and control of a tracked vehicle, a kinematic model with longitudinal and lateral slip is established. Four different nonlinear filters are used to estimate both state vector and time-varying parameter vector of the created model jointly. The first filter is the well-known extended Kalman filter. The second filter is an unscented version of the Kalman filter. The third one is a particle filter using the unscented Kalman filter to generate the importance proposal distribution. The last one is a novel and guaranteed filter that uses a linear set-membership estimator and can give an ellipsoid set in which the true state lies. The four different approaches have different complexities, behavior and advantages that are surveyed and compared.

  16. Element free Galerkin formulation of composite beam with longitudinal slip

    Energy Technology Data Exchange (ETDEWEB)

    Ahmad, Dzulkarnain; Mokhtaram, Mokhtazul Haizad [Department of Civil Engineering, Universiti Selangor, Bestari Jaya, Selangor (Malaysia); Badli, Mohd Iqbal; Yassin, Airil Y. Mohd [Faculty of Civil Engineering, Universiti Teknologi Malaysia, Skudai, Johor (Malaysia)

    2015-05-15

    Behaviour between two materials in composite beam is assumed partially interact when longitudinal slip at its interfacial surfaces is considered. Commonly analysed by the mesh-based formulation, this study used meshless formulation known as Element Free Galerkin (EFG) method in the beam partial interaction analysis, numerically. As meshless formulation implies that the problem domain is discretised only by nodes, the EFG method is based on Moving Least Square (MLS) approach for shape functions formulation with its weak form is developed using variational method. The essential boundary conditions are enforced by Langrange multipliers. The proposed EFG formulation gives comparable results, after been verified by analytical solution, thus signify its application in partial interaction problems. Based on numerical test results, the Cubic Spline and Quartic Spline weight functions yield better accuracy for the EFG formulation, compares to other proposed weight functions.

  17. Magma storage in a strike-slip caldera

    Science.gov (United States)

    Saxby, J.; Gottsmann, J.; Cashman, K.; Gutiérrez, E.

    2016-07-01

    Silicic calderas form during explosive volcanic eruptions when magma withdrawal triggers collapse along bounding faults. The nature of specific interactions between magmatism and tectonism in caldera-forming systems is, however, unclear. Regional stress patterns may control the location and geometry of magma reservoirs, which in turn may control the spatial and temporal development of faults. Here we provide new insight into strike-slip volcano-tectonic relations by analysing Bouguer gravity data from Ilopango caldera, El Salvador, which has a long history of catastrophic explosive eruptions. The observed low gravity beneath the caldera is aligned along the principal horizontal stress orientations of the El Salvador Fault Zone. Data inversion shows that the causative low-density structure extends to ca. 6 km depth, which we interpret as a shallow plumbing system comprising a fractured hydrothermal reservoir overlying a magmatic reservoir with vol% exsolved vapour. Fault-controlled localization of magma constrains potential vent locations for future eruptions.

  18. Heat transfer from cylinders in subsonic slip flows

    Science.gov (United States)

    Nagabushana, K. A.; Stainback, P. C.

    1992-01-01

    The heat transfer in heated wires was measured using a constant temperature anemometer over a Mach number range from 0.05 to 0.4 and pressures from 0.5 to 8.0 atmospheres. The total temperature ranged from 80 to 120 F and the wire diameters were 0.00015, 0.00032, and 0.00050 inch. The heat transfer data is presented in the form of a corrected Nusselt number. Based on suggested criteria, much of the data was obtained in the slip flow regime. Therefore, the data is compared with data having comparable flow conditions. The possible application of the heat transfer data to hot wire anemometry is discussed. To this end, the sensitivity of the wires to velocity, density, and total temperature is computed and compared using two different types of correlations.

  19. Magma storage in a strike-slip caldera.

    Science.gov (United States)

    Saxby, J; Gottsmann, J; Cashman, K; Gutiérrez, E

    2016-07-22

    Silicic calderas form during explosive volcanic eruptions when magma withdrawal triggers collapse along bounding faults. The nature of specific interactions between magmatism and tectonism in caldera-forming systems is, however, unclear. Regional stress patterns may control the location and geometry of magma reservoirs, which in turn may control the spatial and temporal development of faults. Here we provide new insight into strike-slip volcano-tectonic relations by analysing Bouguer gravity data from Ilopango caldera, El Salvador, which has a long history of catastrophic explosive eruptions. The observed low gravity beneath the caldera is aligned along the principal horizontal stress orientations of the El Salvador Fault Zone. Data inversion shows that the causative low-density structure extends to ca. 6 km depth, which we interpret as a shallow plumbing system comprising a fractured hydrothermal reservoir overlying a magmatic reservoir with vol% exsolved vapour. Fault-controlled localization of magma constrains potential vent locations for future eruptions.

  20. Asynchronous slip-ring motor synchronized with permanent magnets

    Directory of Open Access Journals (Sweden)

    Glinka Tadeusz

    2017-03-01

    Full Text Available The electric LSPMSM motor presented in the paper differs from standard induction motor by rotor design. The insulated start-up winding is located in slots along the rotor circumference. The winding ends are connected to the slip-rings. The rotor core contains permanent magnets. The electromechanical characteristics for synchronous operation were calculated, as were the start-up characteristics for operation with a short-circuited rotor winding. Two model motors were used for the calculations, the V-shaped Permanent Magnet (VPM – Fig. 3, and the Linear Permanent Magnet (IPM – Fig. 4, both rated at 14.5 kW. The advantages of the investigated motor are demonstrated in the conclusions.