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Sample records for ground forces study

  1. Government Applications Task Force ground truth study of WAG 4

    Energy Technology Data Exchange (ETDEWEB)

    Evers, T.K.; Smyre, J.L.; King, A.L.

    1997-06-01

    This report documents the Government Applications Task Force (GATF) Buried Waste Project. The project was initiated as a field investigation and verification of the 1994 Strategic Environmental Research and Development Program`s (SERDP) Buried Waste Identification Project results. The GATF project team included staff from three US Department of Energy (DOE) Laboratories [Oak Ridge National Laboratory (ORNL), Los Alamos National Laboratory (LANL), and the Savannah River Technology Center (SRTC)] and from the National Exploitation Laboratory. Similar studies were conducted at each of the three DOE laboratories to demonstrate the effective use of remote sensing technologies. The three locations were selected to assess differences in buried waste signatures under various environmental conditions (i.e., climate, terrain, precipitation, geology, etc.). After a brief background discussion of the SERDP Project, this report documents the field investigation (ground truth) results from the 1994--1995 GATF Buried Waste Study at ORNL`s Waste Area Grouping (WAG) 4. Figures for this report are located in Appendix A.

  2. Comparison of vertical ground reaction forces during overground and treadmill running. A validation study

    Directory of Open Access Journals (Sweden)

    Kluitenberg Bas

    2012-11-01

    Full Text Available Abstract Background One major drawback in measuring ground-reaction forces during running is that it is time consuming to get representative ground-reaction force (GRF values with a traditional force platform. An instrumented force measuring treadmill can overcome the shortcomings inherent to overground testing. The purpose of the current study was to determine the validity of an instrumented force measuring treadmill for measuring vertical ground-reaction force parameters during running. Methods Vertical ground-reaction forces of experienced runners (12 male, 12 female were obtained during overground and treadmill running at slow, preferred and fast self-selected running speeds. For each runner, 7 mean vertical ground-reaction force parameters of the right leg were calculated based on five successful overground steps and 30 seconds of treadmill running data. Intraclass correlations (ICC(3,1 and ratio limits of agreement (RLOA were used for further analysis. Results Qualitatively, the overground and treadmill ground-reaction force curves for heelstrike runners and non-heelstrike runners were very similar. Quantitatively, the time-related parameters and active peak showed excellent agreement (ICCs between 0.76 and 0.95, RLOA between 5.7% and 15.5%. Impact peak showed modest agreement (ICCs between 0.71 and 0.76, RLOA between 19.9% and 28.8%. The maximal and average loading-rate showed modest to excellent ICCs (between 0.70 and 0.89, but RLOA were higher (between 34.3% and 45.4%. Conclusions The results of this study demonstrated that the treadmill is a moderate to highly valid tool for the assessment of vertical ground-reaction forces during running for runners who showed a consistent landing strategy during overground and treadmill running. The high stride-to-stride variance during both overground and treadmill running demonstrates the importance of measuring sufficient steps for representative ground-reaction force values. Therefore, an

  3. Comparison of vertical ground reaction forces during overground and treadmill running. A validation study

    NARCIS (Netherlands)

    Kluitenberg, Bas; Bredeweg, Steef W.; Zijlstra, Sjouke; Zijlstra, Wiebren; Buist, Ida

    2012-01-01

    Background: One major drawback in measuring ground-reaction forces during running is that it is time consuming to get representative ground-reaction force (GRF) values with a traditional force platform. An instrumented force measuring treadmill can overcome the shortcomings inherent to overground te

  4. Comparison of vertical ground reaction forces during overground and treadmill running. A validation study

    NARCIS (Netherlands)

    Kluitenberg, Bas; Bredeweg, Steef W.; Zijlstra, Sjouke; Zijlstra, Wiebren; Buist, Ida

    2012-01-01

    Background: One major drawback in measuring ground-reaction forces during running is that it is time consuming to get representative ground-reaction force (GRF) values with a traditional force platform. An instrumented force measuring treadmill can overcome the shortcomings inherent to overground te

  5. Ambulatory Measurement of Ground Reaction Forces

    NARCIS (Netherlands)

    Veltink, Petrus H.; Liedtke, C.B.; Droog, Adriaan

    2004-01-01

    The measurement of ground reaction forces is important in the biomechanical analysis of gait and other motor activities. It is the purpose of this study to show the feasibility of ambulatory measurement of ground reaction forces using two six degrees of freedom sensors mounted under the shoe. One

  6. History of the Army Ground Forces. Study Number 24. History of the Mountain Training Center

    Science.gov (United States)

    1948-01-01

    An ex- ample Is afforded by the action of men in setting out to retrieve para- chuted loads which had grounded on P potentially dangerous snow slope...skiers in the Office of the Quartermaeter Generar. On 20 May 1943 the Mountain and Winter Warfare Board submitted a list of aug- gestions to the Special...Winter Varfare Board subaitted a list of sug- gestions to the Special Forces Section of the Quartermaster General in Washington regarding a proposed

  7. History of the Army Ground Forces. Study Number 11. Training in the Ground Army 1942-1945

    Science.gov (United States)

    1948-01-01

    Special Staff Seas, Jan 44. 125. History of AGF, Study No 21, Preparation of Units for Overseas Movement, p 6. 126. Memo of Maj David W. Gray for G-3, ACF...the responsibility for developing it reposed in the ’unit omander ." This principle was re- garded as fundamental by General McNair, and when over a

  8. Ambulatory measurement of ground reaction forces

    NARCIS (Netherlands)

    Veltink, Petrus H.; Liedtke, C.B.; Droog, Adriaan; van der Kooij, Herman

    2005-01-01

    The measurement of ground reaction forces is important in the biomechanical analysis of gait and other motor activities. Many applications require full ambulatory measurement of these forces, but this is not supported by current measurement systems. We propose the use of two six-degrees-of-freedom f

  9. Grounding-Induced Sectional Forces and Residual Strength of Grounded Ship Hulls

    DEFF Research Database (Denmark)

    Paik, Jeom Kee; Pedersen, Preben Terndrup

    1996-01-01

    The aim of the present study is to determine the sectional forces induced by ship grounding and also to assess the residual strength of groundedship hulls. An analytical approach is used to estimate the grounding-induced sectional forces of ships. The extent and location of structural damage due...... to grounding is defined based on the ABS Safe Hull guide. The residual strength of damaged hulls is calculated by using a simple analytical formula. The method is applied to residual strength assessment of a damaged double hull tanker of 38,400 dwt due to grounding....

  10. Unmanned ground vehicles for integrated force protection

    Science.gov (United States)

    Carroll, Daniel M.; Mikell, Kenneth; Denewiler, Thomas

    2004-09-01

    The combination of Command and Control (C2) systems with Unmanned Ground Vehicles (UGVs) provides Integrated Force Protection from the Robotic Operation Command Center. Autonomous UGVs are directed as Force Projection units. UGV payloads and fixed sensors provide situational awareness while unattended munitions provide a less-than-lethal response capability. Remote resources serve as automated interfaces to legacy physical devices such as manned response vehicles, barrier gates, fence openings, garage doors, and remote power on/off capability for unmanned systems. The Robotic Operations Command Center executes the Multiple Resource Host Architecture (MRHA) to simultaneously control heterogeneous unmanned systems. The MRHA graphically displays video, map, and status for each resource using wireless digital communications for integrated data, video, and audio. Events are prioritized and the user is prompted with audio alerts and text instructions for alarms and warnings. A control hierarchy of missions and duty rosters support autonomous operations. This paper provides an overview of the key technology enablers for Integrated Force Protection with details on a force-on-force scenario to test and demonstrate concept of operations using Unmanned Ground Vehicles. Special attention is given to development and applications for the Remote Detection Challenge and Response (REDCAR) initiative for Integrated Base Defense.

  11. Quantifying plyometric intensity via rate of force development, knee joint, and ground reaction forces.

    Science.gov (United States)

    Jensen, Randall L; Ebben, William P

    2007-08-01

    Because the intensity of plyometric exercises usually is based simply upon anecdotal recommendations rather than empirical evidence, this study sought to quantify a variety of these exercises based on forces placed upon the knee. Six National Collegiate Athletic Association Division I athletes who routinely trained with plyometric exercises performed depth jumps from 46 and 61 cm, a pike jump, tuck jump, single-leg jump, countermovement jump, squat jump, and a squat jump holding dumbbells equal to 30% of 1 repetition maximum (RM). Ground reaction forces obtained via an AMTI force plate and video analysis of markers placed on the left hip, knee, lateral malleolus, and fifth metatarsal were used to estimate rate of eccentric force development (E-RFD), peak ground reaction forces (GRF), ground reaction forces relative to body weight (GRF/BW), knee joint reaction forces (K-JRF), and knee joint reaction forces relative to body weight (K-JRF/BW) for each plyometric exercise. One-way repeated measures analysis of variance indicated that E-RFD, K-JRF, and K-JRF/BW were different across the conditions (p 0.05). Results indicate that there are quantitative differences between plyometric exercises in the rate of force development during landing and the forces placed on the knee, though peak GRF forces associated with landing may not differ.

  12. Analysis of dynamic foot pressure distribution and ground reaction forces

    Science.gov (United States)

    Ong, F. R.; Wong, T. S.

    2005-04-01

    The purpose of this study was to assess the relationship between forces derived from in-shoe pressure distribution and GRFs during normal gait. The relationship served to demonstrate the accuracy and reliability of the in-shoe pressure sensor. The in-shoe pressure distribution from Tekscan F-Scan system outputs vertical forces and Centre of Force (COF), while the Kistler force plate gives ground reaction forces (GRFs) in terms of Fz, Fx and Fy, as well as vertical torque, Tz. The two systems were synchronized for pressure and GRFs measurements. Data was collected from four volunteers through three trials for both left and right foot under barefoot condition with the in-shoe sensor. The forces derived from pressure distribution correlated well with the vertical GRFs, and the correlation coefficient (r2) was in the range of 0.93 to 0.99. This is a result of extended calibration, which improves pressure measurement to give better accuracy and reliability. The COF from in-shoe sensor generally matched well with the force plate COP. As for the maximum vertical torque at the forefoot during toe-off, there was no relationship with the pressure distribution. However, the maximum torque was shown to give an indication of the rotational angle of the foot.

  13. Systematic review of ground reaction force measurements in cats.

    Science.gov (United States)

    Schnabl, E; Bockstahler, B

    2015-10-01

    Although orthopaedic abnormalities in cats are frequently observed radiographically, they remain clinically underdiagnosed, and kinetic motion analysis, a fundamental aspect of orthopaedic research in dogs and horses, is not commonly performed. More information obtained with non-invasive measurement techniques to assess normal and abnormal gait in cats would provide a greater insight into their locomotion and biomechanics and improve the objective measurement of disease alterations and treatment modalities. In this systematic review, 12 previously performed studies that investigated ground reaction force measurements in cats during locomotion were evaluated. The aims of these studies, the measurement methods and equipment used, and the outcomes of parameters used to assess both sound and diseased cats are summarised and discussed. All reviewed studies used pressure sensitive walkways to gain data and all provided an acclimatisation period as a prerequisite for measurements. In sound cats during walking, the forelimb peak vertical force was greater than in the hindlimb and the peak vertical force in the hindlimb was greater in cats than in dogs. This review confirms that ground reaction forces can be used to evaluate lameness and treatment effects in the cat.

  14. 溜冰机器人地面反作用力的建模研究%Modeling Study of Ground Reaction Force for a Biped Skating Robot

    Institute of Scientific and Technical Information of China (English)

    李金良; 孙友霞

    2014-01-01

    The ground reaction force for a biped skating robot was calculated and analyzed,and a modeling method for the ground reaction force by using convex optimization was proposed. On the basis of reasonable assumption,the modeling of ground reaction force was transformed as a minimization problem of robot kinetic energy after collision under condition with certain constrains,and as a stand-ard convex optimization form. By using CVX software of convex optimization to calculate and simulate the ground reaction force,the re-sults prove the effectiveness of the method.%对两足溜冰机器人的地面反作用力进行了分析与计算,提出了应用凸优化方法进行地面反作用力的建模方法。在合理假设的基础上,将地面反作用力建模问题转换为在一定约束条件下使碰撞后的溜冰机器人动能达到最小的问题,并转化为凸优化的标准形式。应用凸优化程序CVX进行了地面反作用力的计算与仿真,结果证明了该方法的有效性。

  15. System of gait analysis based on ground reaction force assessment

    Directory of Open Access Journals (Sweden)

    František Vaverka

    2015-12-01

    Full Text Available Background: Biomechanical analysis of gait employs various methods used in kinematic and kinetic analysis, EMG, and others. One of the most frequently used methods is kinetic analysis based on the assessment of the ground reaction forces (GRF recorded on two force plates. Objective: The aim of the study was to present a method of gait analysis based on the assessment of the GRF recorded during the stance phase of two steps. Methods: The GRF recorded with a force plate on one leg during stance phase has three components acting in directions: Fx - mediolateral, Fy - anteroposterior, and Fz - vertical. A custom-written MATLAB script was used for gait analysis in this study. This software displays instantaneous force data for both legs as Fx(t, Fy(t and Fz(t curves, automatically determines the extremes of functions and sets the visual markers defining the individual points of interest. Positions of these markers can be easily adjusted by the rater, which may be necessary if the GRF has an atypical pattern. The analysis is fully automated and analyzing one trial takes only 1-2 minutes. Results: The method allows quantification of temporal variables of the extremes of the Fx(t, Fy(t, Fz(t functions, durations of the braking and propulsive phase, duration of the double support phase, the magnitudes of reaction forces in extremes of measured functions, impulses of force, and indices of symmetry. The analysis results in a standardized set of 78 variables (temporal, force, indices of symmetry which can serve as a basis for further research and diagnostics. Conclusions: The resulting set of variable offers a wide choice for selecting a specific group of variables with consideration to a particular research topic. The advantage of this method is the standardization of the GRF analysis, low time requirements allowing rapid analysis of a large number of trials in a short time, and comparability of the variables obtained during different research measurements.

  16. Air Force Implementation is Off the Ground

    Science.gov (United States)

    2013-10-01

    actions taken by the Air Force that have a permanent, positive effect resulting from a particular action area of BBP 2.0. The KC-46 Tanker, F-22 Raptor ...in Europe was able to save $57 million on a back-to-basics approach on its six largest acquisitions by en- couraging early industry involvement to

  17. Solar energy assessment in the Alpine area: satellite data and ground instruments integration for studying the radiative forcing of aerosols.

    Science.gov (United States)

    Castelli, M.; Petitta, M.; Emili, E.

    2012-04-01

    measurement site of Bolzano, where we installed an AERONET sun-photometer for measuring aerosol optical properties and column water-vapor amount. The impact of aerosols on the surface irradiance was already demonstrated, in fact the literature shows that the daily aerosol direct forcing on the surface radiation in the Italian Po valley amounts on average to -12.2 Wm-2, with extremes values beyond -70 Wm-2. In particular here we examine the role in the radiation budget of the Alpine valleys of aerosol microphysical characteristics, such as size distribution, and optical properties, such as phase function, derived from the inversion of spectrally resolved sky radiances. After provided evidence of the radiative impact of atmospheric aerosols on solar energy availability in the Alpine area, the final step will be the enhancement of the most advanced existent algorithm for retrieving SIS in the Alpine area from satellite data, developed by MeteoSwiss in the framework of CM-SAF, which thoroughly considers the effect of topography and clouds, while can still be improved in terms of atmospheric input data.

  18. Forelimb and hindlimb ground reaction forces of walking cats: Assessment and comparison with walking dogs

    NARCIS (Netherlands)

    Corbee, Ronald; Hazewinkel, Herman; Doornenbal, Arie; Maas, Huub

    2014-01-01

    The primary aim of this study was to assess the potential of force plate analysis for describing the stride cycle of the cat. The secondary aim was to define differences in feline and canine locomotion based on force plate characteristics. Ground reaction forces of 24 healthy cats were measured and

  19. Forelimb and hindlimb ground reaction forces of walking cats: Assessment and comparison with walking dogs

    NARCIS (Netherlands)

    Corbee, Ronald; Hazewinkel, Herman; Doornenbal, Arie; Maas, Huub

    2014-01-01

    The primary aim of this study was to assess the potential of force plate analysis for describing the stride cycle of the cat. The secondary aim was to define differences in feline and canine locomotion based on force plate characteristics. Ground reaction forces of 24 healthy cats were measured and

  20. Flexible Forces: US Ground Forces in Future War

    Science.gov (United States)

    2009-03-20

    simply design and create a force we believe to be appropriate. We start not from tabula rasa , but from an established organization whose equipment...increasing pressures of non-national economic interdependency seem to have eroded the role of the traditional nation-state in security affairs. Some...efforts of other countries who resist the roles they have been assigned.” Ibid, pg.44. 13 announced enemy whose capabilities and intentions can drive

  1. Ground reaction forces in ballet dancers landing in flat shoes versus pointe shoes.

    Science.gov (United States)

    Walter, Heather L; Docherty, Carrie L; Schrader, John

    2011-06-01

    Reports in the literature suggest an abundance of lower extremity injuries in ballet dancers; however, few studies have identified the underlying causes of these injuries. Excessive ground reaction forces and shoe type are two potential contributing factors. Eighteen collegiate female ballet majors volunteered for this study. Each participant performed 12 trials of a basic ballet jump, six trials in flat shoes and 6 trials in pointe shoes, landing on a force plate. Ground reaction force (Newtons) and jump height (centimeters) were assessed for each trial. The mean ground reaction force and jump height for each shoe condition was used for statistical analysis. Two dependent t-tests were conducted to determine differences between the shoe types, one for ground reaction force and one for jump height. Alpha level was set at p < .05. We found that the ground reaction force was significantly higher when landing in flat shoes than in pointe shoes (p = .003). There was no significant difference in jump height between the two shoe conditions. This leads us to believe that the increase in ground reaction force was produced primarily by the shoe type.

  2. Bilateral contact ground reaction forces and contact times during plyometric drop jumping.

    Science.gov (United States)

    Ball, Nick B; Stock, Christopher G; Scurr, Joanna C

    2010-10-01

    Drop jumping (DJ) is used in training programs aimed to improve lower extremity explosive power. When performing double-leg drop jumps, it is important to provide an equal stimulus to both legs to ensure balanced development of the lower legs. The aim of this study was to bilaterally analyze the ground reactions forces and temporal components of drop jumping from 3 heights. Ten recreationally active male subjects completed 3 bounce-drop jumps from 3 starting heights (0.2, 0.4, and 0.6 m). Two linked force platforms were used to record left- and right-leg peak vertical force, time to peak force, average force, ground contact time, impulse and time differential. Between-height and between-leg comparisons for each variable were made using a multivariate analysis of variance with post hoc Wilcoxon tests (p vertical forces and temporal components occur; however, shorter contact times were found at the lower heights.

  3. Does an instrumented treadmill correctly measure the ground reaction forces?

    Directory of Open Access Journals (Sweden)

    Patrick A. Willems

    2013-11-01

    Since the 1990s, treadmills have been equipped with multi-axis force transducers to measure the three components of the ground reaction forces during walking and running. These measurements are correctly performed if the whole treadmill (including the motor is mounted on the transducers. In this case, the acceleration of the treadmill centre of mass relative to the reference frame of the laboratory is nil. The external forces exerted on one side of the treadmill are thus equal in magnitude and opposite in direction to the external forces exerted on the other side. However, uncertainty exists about the accuracy of these measures: due to friction between the belt and the tread-surface, due to the motor pulling the belt, some believe that it is not possible to correctly measure the horizontal components of the forces exerted by the feet on the belt. Here, we propose a simple model of an instrumented treadmill and we demonstrate (1 that the forces exerted by the subject moving on the upper part of the treadmill are accurately transmitted to the transducers placed under it and (2 that all internal forces – including friction – between the parts of the treadmill are cancelling each other.

  4. Bolster Ground Force Capabilities in the Asia-Pacific Region

    Science.gov (United States)

    2016-05-12

    Defense, China is “exploiting a power vacuum [in Asia ] with a Cold War mindset. It is tilting the balance of power in its favor against weak...NAVAL WAR COLLEGE Newport, R.I. BOLSTER GROUND FORCE CAPABILITIES IN THE ASIA -PACIFIC REGION by Bryan Dunker Major, United States Army...created them.” – Albert Einstein INTRODUCTION Following the collapse of the Soviet Union and the end of the Cold War in 1991, the United States

  5. The influence of cricket fast bowlers' front leg technique on peak ground reaction forces.

    Science.gov (United States)

    Worthington, Peter; King, Mark; Ranson, Craig

    2013-01-01

    High ground reaction forces during the front foot contact phase of the bowling action are believed to be a major contributor to the high prevalence of lumbar stress fractures in fast bowlers. This study aimed to investigate the influence of front leg technique on peak ground reaction forces during the delivery stride. Three-dimensional kinematic data and ground reaction forces during the front foot contact phase were captured for 20 elite male fast bowlers. Eight kinematic parameters were determined for each performance, describing run-up speed and front leg technique, in addition to peak force and time to peak force in the vertical and horizontal directions. There were substantial variations between bowlers in both peak forces (vertical 6.7 ± 1.4 body weights; horizontal (braking) 4.5 ± 0.8 body weights) and times to peak force (vertical 0.03 ± 0.01 s; horizontal 0.03 ± 0.01 s). These differences were found to be linked to the orientation of the front leg at the instant of front foot contact. In particular, a larger plant angle and a heel strike technique were associated with lower peak forces and longer times to peak force during the front foot contact phase, which may help reduce the likelihood of lower back injuries.

  6. Forelimb and hindlimb ground reaction forces of walking cats: assessment and comparison with walking dogs.

    Science.gov (United States)

    Corbee, R J; Maas, H; Doornenbal, A; Hazewinkel, H A W

    2014-10-01

    The primary aim of this study was to assess the potential of force plate analysis for describing the stride cycle of the cat. The secondary aim was to define differences in feline and canine locomotion based on force plate characteristics. Ground reaction forces of 24 healthy cats were measured and compared with ground reaction forces of 24 healthy dogs. Force-time waveforms in cats generated by force plate analysis were consistent, as reflected by intra-class correlation coefficients for peak vertical force, peak propulsive force and peak braking force (0.94-0.95, 0.85-0.89 and 0.89-0.90, respectively). Compared with dogs, cats had a higher peak vertical force during the propulsion phase (cat, 3.89 ± 0.19 N/kg; dog, 3.03 ± 0.16 N/kg), and a higher hindlimb propulsive force (cat, -1.08 ± 0.13 N/kg; dog, (-0.87 ± 0.13 N/kg) and hindlimb impulse (cat, -0.18 ± 0.03 N/kg; dog, -0.14 ± 0.02 N/kg). Force plate analysis is a valuable tool for the assessment of locomotion in cats, because it can be applied in the clinical setting and provides a non-invasive and objective measurement of locomotion characteristics with high repeatability in cats, as well as information about kinetic characteristics. Differences in force-time waveforms between cats and dogs can be explained by the more crouched position of cats during stance and their more compliant gait compared with dogs. Feline waveforms of the medio-lateral ground reaction forces also differ between cats and dogs and this can be explained by differences in paw supination-pronation. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. Hydrogeology, simulated ground-water flow, and ground-water quality, Wright-Patterson Air Force Base, Ohio

    Science.gov (United States)

    Dumouchelle, D.H.; Schalk, C.W.; Rowe, G.L.; De Roche, J.T.

    1993-01-01

    Ground water is the primary source of water in the Wright-Patterson Air Force Base area. The aquifer consists of glacial sands and gravels that fill a buried bedrock-valley system. Consolidated rocks in the area consist of poorly permeable Ordovician shale of the Richmondian stage, in the upland areas, the Brassfield Limestone of Silurian age. The valleys are filled with glacial sediments of Wisconsinan age consisting of clay-rich tills and coarse-grained outwash deposits. Estimates of hydraulic conductivity of the shales based on results of displacement/recovery tests range from 0.0016 to 12 feet per day; estimates for the glacial sediments range from less than 1 foot per day to more than 1,000 feet per day. Ground water flow from the uplands towards the valleys and the major rivers in the region, the Great Miami and the Mad Rivers. Hydraulic-head data indicate that ground water flows between the bedrock and unconsolidated deposits. Data from a gain/loss study of the Mad River System and hydrographs from nearby wells reveal that the reach of the river next to Wright-Patterson Air Force Base is a ground-water discharge area. A steady-state, three-dimensional ground-water-flow model was developed to simulate ground-water flow in the region. The model contains three layers and encompasses about 100 square miles centered on Wright-Patterson Air Force Base. Ground water enters the modeled area primarily by river leakage and underflow at the model boundary. Ground water exits the modeled area primarily by flow through the valleys at the model boundaries and through production wells. A model sensitivity analysis involving systematic changes in values of hydrologic parameters in the model indicates that the model is most sensitive to decreases in riverbed conductance and vertical conductance between the upper two layers. The analysis also indicates that the contribution of water to the buried-valley aquifer from the bedrock that forms the valley walls is about 2 to 4

  8. BILATERAL GROUND REACTION FORCES AND JOINT MOMENTS FOR LATERAL SIDESTEPPING AND CROSSOVER STEPPING TASKS

    Directory of Open Access Journals (Sweden)

    William I. Sellers

    2009-03-01

    Full Text Available Racquet sports have high levels of joint injuries suggesting the joint loads during play may be excessive. Sports such as badminton employ lateral sidestepping (SS and crossover stepping (XS movements which so far have not been described in terms of biomechanics. This study examined bilateral ground reaction forces and three dimensional joint kinetics for both these gaits in order to determine the demands of the movements on the leading and trailing limb and predict the contribution of these movements to the occurrence of overuse injury of the lower limbs. A force platform and motion-analysis system were used to record ground reaction forces and track marker trajectories of 9 experienced male badminton players performing lateral SS, XS and forward running tasks at a controlled speed of 3 m·s-1 using their normal technique. Ground reaction force and kinetic data for the hip, knee and ankle were analyzed, averaged across the group and the biomechanical variables compared. In all cases the ground reaction forces and joint moments were less than those experienced during moderate running suggesting that in normal play SS and XS gaits do not lead to high forces that could contribute to increased injury risk. Ground reaction forces during SS and XS do not appear to contribute to the development of overuse injury. The distinct roles of the leading and trailing limb, acting as a generator of vertical force and shock absorber respectively, during the SS and XS may however contribute to the development of muscular imbalances which may ultimately contribute to the development of overuse injury. However it is still possible that faulty use of these gaits might lead to high loads and this should be the subject of future work

  9. Kinematic and ground reaction force accommodation during weighted walking.

    Science.gov (United States)

    James, C Roger; Atkins, Lee T; Yang, Hyung Suk; Dufek, Janet S; Bates, Barry T

    2015-12-01

    Weighted walking is a functional activity common in daily life and can influence risks for musculoskeletal loading, injury and falling. Much information exists about weighted walking during military, occupational and recreational tasks, but less is known about strategies used to accommodate to weight carriage typical in daily life. The purposes of the study were to examine the effects of weight carriage on kinematics and peak ground reaction force (GRF) during walking, and explore relationships between these variables. Twenty subjects walked on a treadmill while carrying 0, 44.5 and 89 N weights in front of the body. Peak GRF, sagittal plane joint/segment angular kinematics, stride length and center of mass (COM) vertical displacement were measured. Changes in peak GRF and displacement variables between weight conditions represented accommodation. Effects of weight carriage were tested using analysis of variance. Relationships between peak GRF and kinematic accommodation variables were examined using correlation and regression. Subjects were classified into sub-groups based on peak GRF responses and the correlation analysis was repeated. Weight carriage increased peak GRF by an amount greater than the weight carried, decreased stride length, increased vertical COM displacement, and resulted in a more extended and upright posture, with less hip and trunk displacement during weight acceptance. A GRF increase was associated with decreases in hip extension (|r|=.53, p=.020) and thigh anterior rotation (|r|=.57, p=.009) displacements, and an increase in foot anterior rotation displacement (|r|=.58, p=.008). Sub-group analysis revealed that greater GRF increases were associated with changes at multiple sites, while lesser GRF increases were associated with changes in foot and trunk displacement. Weight carriage affected walking kinematics and revealed different accommodation strategies that could have implications for loading and stability.

  10. Ground Reaction Forces During Reduced Gravity Running in Parabolic Flight.

    Science.gov (United States)

    Cavanagh, Peter; Rice, Andrea; Glauberman, Molly; Sudduth, Amanda; Cherones, Arien; Davis, Shane; Lewis, Michael; Hanson, Andrea; Wilt, Grier

    2017-08-01

    Treadmills have been employed as both a form of exercise and a countermeasure to prevent changes in the musculoskeletal system on almost all NASA missions and many Russian missions since the early Space Shuttle flights. It is possible that treadmills may also be part of exercise programs on future Mars missions and that they may be a component of exercise facilities in lunar or Martian habitats. In order to determine if the ambient gravity on these destinations will provide osteogenic effects while performing exercise on a treadmill, ground reactions forces (GRFs) were measured on eight subjects (six women and two men) running at 6 mph during parabolic flight in Martian and lunar gravity conditions. On average, stride length increased as gravity decreased. The first and second peaks of the GRFs decreased by 0.156 and 0.196 bodyweights, respectively, per 1/10 g change in ambient gravity. Based on comparisons with previously measured GRF during loaded treadmill running on the International Space Station, we conclude that unloaded treadmill running under lunar and Martian conditions during exploration missions is not likely to be an osteo-protective exercise.Cavanagh P, Rice A, Glauberman M, Sudduth A, Cherones A, Davis S, Lewis M, Hanson A, Wilt G. Ground reaction forces during reduced gravity running in parabolic flight. Aerosp Med Hum Perform. 2017; 88(8):730-736.

  11. Running-specific prostheses limit ground-force during sprinting

    Science.gov (United States)

    Grabowski, Alena M.; McGowan, Craig P.; McDermott, William J.; Beale, Matthew T.; Kram, Rodger; Herr, Hugh M.

    2010-01-01

    Running-specific prostheses (RSP) emulate the spring-like behaviour of biological limbs during human running, but little research has examined the mechanical means by which amputees achieve top speeds. To better understand the biomechanical effects of RSP during sprinting, we measured ground reaction forces (GRF) and stride kinematics of elite unilateral trans-tibial amputee sprinters across a range of speeds including top speed. Unilateral amputees are ideal subjects because each amputee's affected leg (AL) can be compared with their unaffected leg (UL). We found that stance average vertical GRF were approximately 9 per cent less for the AL compared with the UL across a range of speeds including top speed (p < 0.0001). In contrast, leg swing times were not significantly different between legs at any speed (p = 0.32). Additionally, AL and UL leg swing times were similar to those reported for non-amputee sprinters. We infer that RSP impair force generation and thus probably limit top speed. Some elite unilateral trans-tibial amputee sprinters appear to have learned or trained to compensate for AL force impairment by swinging both legs rapidly. PMID:19889694

  12. Do ground reaction forces during unilateral and bilateral movements exhibit compensation strategies following ACL reconstruction?

    NARCIS (Netherlands)

    Baumgart, Christian; Schubert, Markus; Hoppe, Matthias W.; Gokeler, Alli; Freiwald, Juergen

    The aims of the study were (1) to evaluate the leg asymmetry assessed with ground reaction forces (GRFs) during unilateral and bilateral movements of different knee loads in anterior cruciate ligament (ACL) reconstructed patients and (2) to investigate differences in leg asymmetry depending on the

  13. Validation of vertical ground reaction forces on individual limbs calculated from kinematics of horse locomotion.

    Science.gov (United States)

    Bobbert, Maarten F; Gómez Alvarez, Constanza B; van Weeren, P René; Roepstorff, Lars; Weishaupt, Michael A

    2007-06-01

    The purpose of this study was to determine whether individual limb forces could be calculated accurately from kinematics of trotting and walking horses. We collected kinematic data and measured vertical ground reaction forces on the individual limbs of seven Warmblood dressage horses, trotting at 3.4 m s(-1) and walking at 1.6 m s(-1) on a treadmill. First, using a segmental model, we calculated from kinematics the total ground reaction force vector and its moment arm relative to each of the hoofs. Second, for phases in which the body was supported by only two limbs, we calculated the individual reaction forces on these limbs. Third, we assumed that the distal limbs operated as linear springs, and determined their force-length relationships using calculated individual limb forces at trot. Finally, we calculated individual limb force-time histories from distal limb lengths. A good correspondence was obtained between calculated and measured individual limb forces. At trot, the average peak vertical reaction force on the forelimb was calculated to be 11.5+/-0.9 N kg(-1) and measured to be 11.7+/-0.9 N kg(-1), and for the hindlimb these values were 9.8+/-0.7 N kg(-1) and 10.0+/-0.6 N kg(-1), respectively. At walk, the average peak vertical reaction force on the forelimb was calculated to be 6.9+/-0.5 N kg(-1) and measured to be 7.1+/-0.3 N kg(-1), and for the hindlimb these values were 4.8+/-0.5 N kg(-1) and 4.7+/-0.3 N kg(-1), respectively. It was concluded that the proposed method of calculating individual limb reaction forces is sufficiently accurate to detect changes in loading reported in the literature for mild to moderate lameness at trot.

  14. Effects of Cooling on Ankle Muscle Strength, Electromyography, and Gait Ground Reaction Forces

    Directory of Open Access Journals (Sweden)

    Amitava Halder

    2014-01-01

    Full Text Available The effects of cooling on neuromuscular function and performance during gait are not fully examined. The purpose of this study was to investigate the effects of local cooling for 20 min in cold water at 10°C in a climate chamber also at 10°C on maximal isometric force and electromyographic (EMG activity of the lower leg muscles. Gait ground reaction forces (GRFs were also assessed. Sixteen healthy university students participated in the within subject design experimental study. Isometric forces of the tibialis anterior (TA and the gastrocnemius medialis (GM were measured using a handheld dynamometer and the EMG was recorded using surface electrodes. Ground reaction forces during gait and the required coefficient of friction (RCOF were recorded using a force plate. There was a significantly reduced isometric maximum force in the TA muscle (P<0.001 after cooling. The mean EMG amplitude of GM muscle was increased after cooling (P<0.003, indicating that fatigue was induced. We found no significant changes in the gait GRFs and RCOF on dry and level surface. These findings may indicate that local moderate cooling 20 min of 10°C cold water, may influence maximal muscle performance without affecting activities at sub-maximal effort.

  15. Acute fatigue effects on ground reaction force of lower limbs during countermovement jumps

    OpenAIRE

    Carlos Gabriel Fábrica; González,Paula V.; Jefferson Fagundes Loss

    2013-01-01

    Parameters associated with the performance of countermovement jumps were identified from vertical ground reaction force recordings during fatigue and resting conditions. Fourteen variables were defined, dividing the vertical ground reaction force into negative and positive external working times and times in which the vertical ground reaction force values were lower and higher than the participant's body weight. We attempted to explain parameter variations by considering the relationship betw...

  16. Grizzly bear (Ursus arctos horribilis) locomotion: gaits and ground reaction forces.

    Science.gov (United States)

    Shine, Catherine L; Penberthy, Skylar; Robbins, Charles T; Nelson, O Lynne; McGowan, Craig P

    2015-10-01

    Locomotion of plantigrade generalists has been relatively little studied compared with more specialised postures even though plantigrady is ancestral among quadrupeds. Bears (Ursidae) are a representative family for plantigrade carnivorans, they have the majority of the morphological characteristics identified for plantigrade species, and they have the full range of generalist behaviours. This study compared the locomotion of adult grizzly bears (Ursus arctos horribilis Linnaeus 1758), including stride parameters, gaits and analysis of three-dimensional ground reaction forces, with that of previously studied quadrupeds. At slow to moderate speeds, grizzly bears use walks, running walks and canters. Vertical ground reaction forces demonstrated the typical M-shaped curve for walks; however, this was significantly more pronounced in the hindlimb. The rate of force development was also significantly higher for the hindlimbs than for the forelimbs at all speeds. Mediolateral forces were significantly higher than would be expected for a large erect mammal, almost to the extent of a sprawling crocodilian. There may be morphological or energetic explanations for the use of the running walk rather than the trot. The high medial forces (produced from a lateral push by the animal) could be caused by frontal plane movement of the carpus and elbow by bears. Overall, while grizzly bears share some similarities with large cursorial species, their locomotor kinetics have unique characteristics. Additional studies are needed to determine whether these characters are a feature of all bears or plantigrade species.

  17. Ground reaction forces during walking with different load and slope combinations in rats.

    Science.gov (United States)

    Bravenboer, N; van Rens, B T T M; van Essen, H W; van Dieën, J H; Lips, P

    2017-08-31

    Treadmill animal models are commonly used to study effects of exercise on bone. Since mechanical loading induces bone strain, resulting in bone formation, exercise that induces higher strains is likely to cause more bone formation. Our aim was to investigate the effect of slope and additional load on limb bone strain. Horizontal and vertical ground reaction forces on left fore-limb (FL) and hind-limb (HL) of twenty 23-week old female Wistar rats (weight 279 ± 26 g) were measured for six combinations of SLOPE (-10°, 0°, +10°) and LOAD (0 to 23% of body mass). Peak force (Fmax), rate of force rise (RC), stance time (Tstance) and impulse (Fint) on FLs and HLs were analyzed. For the FL, peak ground reaction forces and rate of force rise were highest when walking downward -10° with load (Fmax = 2.09±0.05 N, FLRC = 34±2 N/s) For the HL, ground reaction forces and rate of force rise were highest when walking upward +10°, without load (Fmax = 2.20±0.05 N, HLRC = 34±1 N/s). Load increased stance time. Without additional load, estimates for the highest FL loading (slope is -10°) were larger than for the highest HL loading (slope is +10°) relative to level walking. Thus, walking downward has a higher impact on FL bones, while walking upward is a more optimal HL exercise. Additional load may have a small effect on FL loading.

  18. Exercise Countermeasures for Bone Loss During Space Flight: A Method for the Study of Ground Reaction Forces and their Implications for Bone Strain

    Science.gov (United States)

    Peterman, M.; McCrory, J. L.; Sharkey, N. A.; Piazza, S.; Cavanagh, P. R.

    1999-01-01

    already scheduled for hip surgery. Lu et al. (1997) used an instrumented massive proximal femoral prosthesis along with electromyographic measurements to demonstrate that femoral forces depend on muscular activity. These analyses of in vivo bone mechanics are valuable. The invasive nature of the procedures involved, however, limits both the number of subjects and the number of strain gauge locations. Further, the results of these studies may be confounded by the inclusion of subjects with pathological conditions. Gross et al. (1992) measured strain at three locations on the equine third metacarpal and used those data to construct a computer model of the internal strain environment of the bone. An analogous placement of multiple gauges in living humans would be difficult and potentially hazardous because of the depth of soft tissue overlying the tibia and femur.

  19. Ambulatory assessment of 3D ground reaction force using plantar pressure distribution.

    Science.gov (United States)

    Rouhani, H; Favre, J; Crevoisier, X; Aminian, K

    2010-07-01

    This study aimed to use the plantar pressure insole for estimating the three-dimensional ground reaction force (GRF) as well as the frictional torque (T(F)) during walking. Eleven subjects, six healthy and five patients with ankle disease participated in the study while wearing pressure insoles during several walking trials on a force-plate. The plantar pressure distribution was analyzed and 10 principal components of 24 regional pressure values with the stance time percentage (STP) were considered for GRF and T(F) estimation. Both linear and non-linear approximators were used for estimating the GRF and T(F) based on two learning strategies using intra-subject and inter-subjects data. The RMS error and the correlation coefficient between the approximators and the actual patterns obtained from force-plate were calculated. Our results showed better performance for non-linear approximation especially when the STP was considered as input. The least errors were observed for vertical force (4%) and anterior-posterior force (7.3%), while the medial-lateral force (11.3%) and frictional torque (14.7%) had higher errors. The result obtained for the patients showed higher error; nevertheless, when the data of the same patient were used for learning, the results were improved and in general slight differences with healthy subjects were observed. In conclusion, this study showed that ambulatory pressure insole with data normalization, an optimal choice of inputs and a well-trained nonlinear mapping function can estimate efficiently the three-dimensional ground reaction force and frictional torque in consecutive gait cycle without requiring a force-plate.

  20. Evaluation of instrumented shoes for ambulatory assessment of ground reaction forces

    NARCIS (Netherlands)

    Liedtke, Christian; Fokkenrood, Steven A.W.; Menger, Jasper T.; Kooij, van der Herman; Veltink, Peter H.

    2007-01-01

    Currently, force plates or pressure sensitive insoles are the standard tools to measure ground reaction forces and centre of pressure data during human gait. Force plates, however, impose constraints on foot placement, and the available pressure sensitive insoles measure only one component of force.

  1. Measured and estimated ground reaction forces for multi-segment foot models.

    Science.gov (United States)

    Bruening, Dustin A; Cooney, Kevin M; Buczek, Frank L; Richards, James G

    2010-12-01

    Accurate measurement of ground reaction forces under discrete areas of the foot is important in the development of more advanced foot models, which can improve our understanding of foot and ankle function. To overcome current equipment limitations, a few investigators have proposed combining a pressure mat with a single force platform and using a proportionality assumption to estimate subarea shear forces and free moments. In this study, two adjacent force platforms were used to evaluate the accuracy of the proportionality assumption on a three segment foot model during normal gait. Seventeen right feet were tested using a targeted walking approach, isolating two separate joints: transverse tarsal and metatarsophalangeal. Root mean square (RMS) errors in shear forces up to 6% body weight (BW) were found using the proportionality assumption, with the highest errors (peak absolute errors up to 12% BW) occurring between the forefoot and toes in terminal stance. The hallux exerted a small braking force in opposition to the propulsive force of the forefoot, which was unaccounted for by the proportionality assumption. While the assumption may be suitable for specific applications (e.g. gait analysis models), it is important to understand that some information on foot function can be lost. The results help highlight possible limitations of the assumption. Measured ensemble average subarea shear forces during normal gait are also presented for the first time.

  2. Gender Differences among Sagittal Plane Knee Kinematic and Ground Reaction Force Characteristics during a Rapid Sprint and Cut Maneuver

    Science.gov (United States)

    James, C. Roger; Sizer, Phillip S.; Starch, David W.; Lockhart, Thurmon E.; Slauterbeck, James

    2004-01-01

    Women are more prone to anterior cruciate ligament (ACL) injury during cutting sports than men. The purpose of this study was to examine knee kinematic and ground reaction forces (GRF) differences between genders during cutting. Male and female athletes performed cutting trials while force platform and video data were recorded (180 Hz).…

  3. Determination of the vertical ground reaction forces acting upon individual limbs during healthy and clinical gait.

    Science.gov (United States)

    Meurisse, Guillaume M; Dierick, Frédéric; Schepens, Bénédicte; Bastien, Guillaume J

    2016-01-01

    In gait lab, the quantification of the ground reaction forces (GRFs) acting upon individual limbs is required for dynamic analysis. However, using a single force plate, only the resultant GRF acting on both limbs is available. The aims of this study are (a) to develop an algorithm allowing a reliable detection of the front foot contact (FC) and the back foot off (FO) time events when walking on a single plate, (b) to reconstruct the vertical GRFs acting upon each limb during the double contact phase (DC) and (c) to evaluate this reconstruction on healthy and clinical gait trials. For the purpose of the study, 811 force measurements during DC were analyzed based on walking trials from 27 healthy subjects and 88 patients. FC and FO are reliably detected using a novel method based on the distance covered by the centre of pressure. The algorithm for the force reconstruction is a revised version of the approach of Davis and Cavanagh [24]. In order to assess the robustness of the algorithm, we compare the resulting GRFs with the real forces measured with individual force plates. The median of the relative error on force reconstruction is 1.8% for the healthy gait and 2.5% for the clinical gait. The reconstructed and the real GRFs during DC are strongly correlated for both healthy and clinical gait data (R(2)=0.998 and 0.991, respectively).

  4. Validity and reliability of pressure-measurement insoles for vertical ground reaction force assessment in field situations.

    Science.gov (United States)

    Koch, Markus; Lunde, Lars-Kristian; Ernst, Michael; Knardahl, Stein; Veiersted, Kaj Bo

    2016-03-01

    This study aimed to test the validity and reliability of pressure-measurement insoles (medilogic® insoles) when measuring vertical ground reaction forces in field situations. Various weights were applied to and removed from the insoles in static mechanical tests. The force values measured simultaneously by the insoles and force plates were compared for 15 subjects simulating work activities. Reliability testing during the static mechanical tests yielded an average interclass correlation coefficient of 0.998. Static loads led to a creeping pattern of the output force signal. An individual load response could be observed for each insole. The average root mean square error between the insoles and force plates ranged from 6.6% to 17.7% in standing, walking, lifting and catching trials and was 142.3% in kneeling trials. The results show that the use of insoles may be an acceptable method for measuring vertical ground reaction forces in field studies, except for kneeling positions.

  5. Acute fatigue effects on ground reaction force of lower limbs during countermovement jumps

    Directory of Open Access Journals (Sweden)

    Carlos Gabriel Fábrica

    2013-12-01

    Full Text Available Parameters associated with the performance of countermovement jumps were identified from vertical ground reaction force recordings during fatigue and resting conditions. Fourteen variables were defined, dividing the vertical ground reaction force into negative and positive external working times and times in which the vertical ground reaction force values were lower and higher than the participant's body weight. We attempted to explain parameter variations by considering the relationship between the set of contractile and elastic components of the lower limbs. We determined that jumping performance is based on impulsion optimization and not on instantaneous ground reaction force value: the time in which the ground reaction force was lower than the body weight, and negative external work time was lower under fatigue. The results suggest that, during fatigue, there is less contribution from elastic energy and from overall active state. However, the participation of contractile elements could partially compensate for the worsening of jumping performance.

  6. Does walking in a virtual environment induce unstable gait? An examination of vertical ground reaction forces.

    Science.gov (United States)

    Hollman, John H; Brey, Robert H; Bang, Tami J; Kaufman, Kenton R

    2007-07-01

    Virtual reality (VR) can induce postural instability in standing and walking, as quantified with kinematic parameters. This study examines the effect of a VR environment on kinetic gait parameters. Ten healthy volunteers walked on an instrumented treadmill in a VR environment and a non-VR environment. In the VR environment, a corridor with colored vertical stripes comprising the walls was projected onto a concave screen placed in front of the treadmill. The speed of the moving image was perceptually equivalent to the speed of the treadmill, creating an illusion that subjects walked through the corridor. Vertical ground reaction forces were sampled. Kinetic parameters that reflect gait stability (weight acceptance peak force, weight acceptance rate, push-off peak force and push-off rate) were compared between the VR and non-VR environments. Subjects walked in the VR environment with increased magnitudes and rates of weight acceptance force and with increased rates of push-off force. Variability in weight acceptance rates and peak forces, and variability in push-off peak forces, were also increased in the VR environment. The gait deviations reflect a compensatory response to visual stimulation that occurs in the VR environment, suggesting that walking in a VR environment may induce gait instability in healthy subjects.

  7. GROUND REACTION FORCE DIFFERENCES BETWEEN RUNNING SHOES, RACING FLATS, AND DISTANCE SPIKES IN RUNNERS

    Directory of Open Access Journals (Sweden)

    Suzanna Logan

    2010-03-01

    Full Text Available Various shoes are worn by distance runners throughout a training season. This study measured the differences in ground reaction forces between running shoes, racing flats, and distance spikes in order to provide information about the potential effects of footwear on injury risk in highly competitive runners. Ten male and ten female intercollegiate distance runners ran across a force plate at 6.7 m·s-1 (for males and 5.7 m·s-1 (for females in each of the three types of shoes. To control for differences in foot strike, only subjects who exhibited a heel strike were included in the data analysis. Two repeated-measures ANOVAs with Tukey's post-hoc tests (p < 0.05 were used to detect differences in shoe types among males and females. For the males, loading rate, peak vertical impact force and peak braking forces were significantly greater in flats and spikes compared to running shoes. Vertical stiffness in spikes was also significantly greater than in running shoes. Females had significantly shorter stance times and greater maximum propulsion forces in racing flats compared to running shoes. Changing footwear between the shoes used in this study alters the loads placed on the body. Care should be taken as athletes enter different phases of training where different footwear is required. Injury risk may be increased since the body may not be accustomed to the differences in force, stance time, and vertical stiffness

  8. Comparisons of peak ground reaction force and rate of force development during variations of the power clean.

    Science.gov (United States)

    Comfort, Paul; Allen, Mark; Graham-Smith, Phillip

    2011-05-01

    The aim of this investigation was to determine the differences in vertical ground reaction forces and rate of force development (RFD) during variations of the power clean. Elite rugby league players (n = 11; age 21 ± 1.63 years; height 181.56 ± 2.61 cm; body mass 93.65 ± 6.84 kg) performed 1 set of 3 repetitions of the power clean, hang-power clean, midthigh power clean, or midthigh clean pull, using 60% of 1-repetition maximum power clean, in a randomized order, while standing on a force platform. Differences in peak vertical ground reaction forces (F(z)) and instantaneous RFD between lifts were analyzed via 1-way analysis of variance and Bonferroni post hoc analysis. Statistical analysis revealed a significantly (p < 0.001) greater peak F(z) during the midthigh power clean (2,801.7 ± 195.4 N) and the midthigh clean pull (2,880.2 ± 236.2 N) compared to both the power clean (2,306.24 ± 240.47 N) and the hang-power clean (2,442.9 ± 293.2 N). The midthigh power clean (14,655.8 ± 4,535.1 N·s⁻¹) and the midthigh clean pull (15,320.6 ± 3,533.3 N·s⁻¹) also demonstrated significantly (p < 0.001) greater instantaneous RFD when compared to both the power clean (8,839.7 ± 2,940.4 N·s⁻¹) and the hang-power clean (9,768.9 ± 4,012.4 N·s⁻¹). From the findings of this study, when training to maximize peak F(z) and RFD the midthigh power clean and midthigh clean pull appear to be the most advantageous variations of the power clean to perform.

  9. Ground reaction forces and kinematics in distance running in older-aged men.

    Science.gov (United States)

    Bus, Sicco A

    2003-07-01

    The biomechanics of distance running has not been studied before in older-aged runners but may be different than in younger-aged runners because of musculoskeletal degeneration at older age. This study aimed at determining whether the stance phase kinematics and ground reaction forces in running are different between younger- and older-aged men. Lower-extremity kinematics using three-dimensional motion analysis and ground reaction forces (GRF) using a force plate were assessed in 16 older-aged (55-65 yr) and 13 younger-aged (20-35 yr) well-trained male distance runners running at a self-selected (SRS) and a controlled (CRS) speed of 3.3 m.s-1. The older subjects ran at significantly lower self-selected speeds than the younger subjects (mean 3.34 vs 3.77 m.s-1). In both speed conditions, the older runners exhibited significantly more knee flexion at heel strike and significantly less knee flexion and extension range of motion. No age group differences were present in subtalar joint motion. Impact peak force (1.91 vs 1.70 BW) and maximal initial loading rate (107.5 vs 85.5 BW.s-1) were significantly higher in the older runners at the CRS. Maximal peak vertical and anteroposterior forces and impulses were significantly lower in the older runners at the SRS. The biomechanics of running is different between older- and younger-aged runners on several relevant parameters. The larger impact peak force and initial loading rate indicate a loss of shock-absorbing capacity in the older runners. This may increase their susceptibility to lower-extremity overuse injuries. Moreover, it emphasizes the focus on optimizing cushioning properties in the design and prescription of running shoes and suggests that older-aged runners should be cautious with running under conditions of high impact.

  10. Comparison of natural and artificial forcing to study the dynamic behaviour of bell towers in low wind context by means of ground-based radar interferometry: the case of the Leaning Tower in Pisa

    Science.gov (United States)

    Marchisio, Mario; Piroddi, Luca; Ranieri, Gaetano; Calcina, Sergio V.; Farina, Paolo

    2014-10-01

    The study of Cultural Heritage assets needs the application of non-destructive and non-invasive monitoring techniques. In particular, monuments and historical buildings which are open to the visitors and/or subject to important stress must be studied for their dynamic response. In the last 10 years the new ground-based radar interferometry technology has been developed allowing to monitor displacements from a point of sight far from the studied targets. It virtually provides a continuous mapping of displacements of the observed structures up to 10 µm with a range resolution of 0.75 m. In this paper, the application of ground-based interferometry on one very important historical building, the Leaning Tower of Pisa in Italy, is reported. The analysis of these kind of structures is important to catch their dynamic response to natural actions in general, and also to assess the effects due to pedestrian and users, and consequently to define functional capabilities and levels of acceptable dynamic stress. The studied structure was subject to artificial loading by synchronous movement of about 20 people. Artificial forcing led the structure to a resonance condition with the same frequency of the one due to the natural noise excitation, which was separately measured, and with an oscillation amplitude more than thirty times greater than the natural one (in conditions of weak wind). During the passive stages of the survey the recorded structural vibrations were very closed to the instrumental sensitivity, making difficult to distinguish vibration amplitudes amplifications of various segments at various heights. Through the spectral analysis of the acquired data it was possible to estimate the vibration frequencies of the first modal shapes of the structure along two orthogonal directions. The power spectra of the passive survey data have the same maximum frequency of the active but contain more noise at low frequency.

  11. Software for analysis of equine ground reaction force data

    NARCIS (Netherlands)

    Schamhardt, H.C.; Merkens, H.W.; Lammertink, J.L.M.A.

    1986-01-01

    Software for analysis of force plate recordings of the horse at normal walk is described. The data of a number of stance phases are averaged to obtain a representative tracing of that horse. The amplitudes of a number of characteristic peaks in the force-time curves are used to compare left and righ

  12. Ground reaction force differences between running shoes, racing flats, and distance spikes in runners.

    Science.gov (United States)

    Logan, Suzanna; Hunter, Ian; J Ty Hopkins, J T; Feland, J Brent; Parcell, Allen C

    2010-01-01

    Various shoes are worn by distance runners throughout a training season. This study measured the differences in ground reaction forces between running shoes, racing flats, and distance spikes in order to provide information about the potential effects of footwear on injury risk in highly competitive runners. Ten male and ten female intercollegiate distance runners ran across a force plate at 6.7 m·s(-1) (for males) and 5.7 m·s(-1) (for females) in each of the three types of shoes. To control for differences in foot strike, only subjects who exhibited a heel strike were included in the data analysis. Two repeated-measures ANOVAs with Tukey's post-hoc tests (p force and peak braking forces were significantly greater in flats and spikes compared to running shoes. Vertical stiffness in spikes was also significantly greater than in running shoes. Females had significantly shorter stance times and greater maximum propulsion forces in racing flats compared to running shoes. Changing footwear between the shoes used in this study alters the loads placed on the body. Care should be taken as athletes enter different phases of training where different footwear is required. Injury risk may be increased since the body may not be accustomed to the differences in force, stance time, and vertical stiffness. Key pointsTo determine the differences in ground reaction forces between regular running shoes and competitive footwear, force plate data was obtained from 10 males (6.7 m·s(-1)) and 10 females (5.7 m·s(-1)) for each of three shoe types.Data from men and women were analyzed in two separate groups, and significant differences were found for various GRF components between the three types of shoes.The significant increases in GRF components in competitive footwear suggest that the body must deal with greater impact forces in these shoes than in running shoes at the same running speed.The results from this study warrant the recommendation that runners transition gradually from

  13. Force Employment Study (FES)

    Science.gov (United States)

    1991-02-01

    E-2 E-6 Snow Removal, Providence .. ....... ...........E-2 E-7 Tornado, Hopkinville, KY .. ....... ...........E-2 E-8 Volcano , Mt...Del Valle. The National Assembly met late on 25 Feb and replaced Del Valle with a Noriega-supported president, Solis- Palma . On 16 March, there was a... volcano eruption. Force composition: See Figure 3-18 Component: Active Army Man-day expenditure: 426 soldiers; 8,086 man-days Mode of deployment

  14. Vertical peak ground force in human infant crawling.

    Science.gov (United States)

    Yozu, Arito; Haga, Nobuhiko; Tojima, Michio; Zhang, Yasu; Sumitani, Masahiko; Otake, Yuko

    2013-02-01

    Quadrupedalism is a common mode of locomotion in land animals. The load distribution between the forelimbs (FL) and hindlimbs (HL) in quadrupedalism has been of great interest to researchers, and a database of the vertical peak force (Vpk) for FL and HL has been created for various species. However, Vpk in human infant crawling, a natural form of human quadrupedalism, has not been evaluated. We aimed to study Vpk in human infant crawling. Eight healthy infants who used a typical crawling style (i.e., crawling on the hands and knees) were included. The infants were encouraged to crawl over pressure mats placed on the floor, and Vpk of FL and HL were calculated. FL Vpk was 0.631±0.087 (per BW), and HL Vpk was 0.638±0.089 (per BW). No significant difference was observed between FL and HL Vpk. The mean FL/HL Vpk ratio was -0.011 on a natural logarithmic scale. These data could be added to the current database on Vpk for quadrupedalism.

  15. (Environmental investigation of ground water contamination at Wright-Patterson Air Force Base, Ohio)

    Energy Technology Data Exchange (ETDEWEB)

    1991-10-01

    This report presents information concerning field procedures employed during the monitoring, well construction, well purging, sampling, and well logging at the Wright-Patterson Air Force Base. Activities were conducted in an effort to evaluate ground water contamination.

  16. Isokinetic analysis of ankle and ground reaction forces in runners and triathletes

    National Research Council Canada - National Science Library

    Luna, Natália Mariana Silva; Alonso, Angelica Castilho; Brech, Guilherme Carlos; Mochizuki, Luis; Nakano, Eduardo Yoshio; Greve, Júlia Maria D'Andrea

    2012-01-01

    OBJECTIVE: To analyze and compare the vertical component of ground reaction forces and isokinetic muscle parameters for plantar flexion and dorsiflexion of the ankle between long-distance runners, triathletes, and nonathletes. METHODS...

  17. Ground reaction forces and lower-limb joint kinetics of turning gait in typically developing children.

    Science.gov (United States)

    Dixon, Philippe C; Stebbins, Julie; Theologis, Tim; Zavatsky, Amy B

    2014-11-28

    Turning is a common locomotor task essential to daily activity; however, very little is known about the forces and moments responsible for the kinematic adaptations occurring relative to straight-line gait in typically developing children. Thus, the aims of this study were to analyse ground reaction forces (GRFs), ground reaction free vertical torque (TZ), and the lower-limb joint kinetics of 90° outside (step) and inside (spin) limb turns. Step, spin, and straight walking trials from fifty-four typically developing children were analysed. All children were fit with the Plug-in Gait and Oxford Foot Model marker sets while walking over force plates embedded in the walkway. Net internal joint moments and power were computed via a standard inverse dynamics approach. All dependent variables were statistically analysed over the entire curves using the mean difference 95% bootstrap confidence band approach. GRFs were directed medially for step turns and laterally for spin turns during the turning phase. Directions were reversed and magnitudes decreased during the approach phase. Step turns showed reduced ankle power generation, while spin turns showed large TZ. Both strategies required large knee and hip coronal and transverse plane moments during swing. These kinetic differences highlight adaptations required to maintain stability and reorient the body towards the new walking direction during turning. From a clinical perspective, turning gait may better reveal weaknesses and motor control deficits than straight walking in pathological populations, such as children with cerebral palsy, and could potentially be implemented in standard gait analysis sessions.

  18. Comparison of ground reaction forces during the Basic Step on the Core Board platform at various levels of stability.

    Science.gov (United States)

    Karczewska, Magdalena; Madej, Anna; Sadowska, Aleksandra; Mastalerz, Andrzej; Urbanik, Czesław

    2016-01-01

    The aim of this paper was to examine and compare the changes of ground reaction forces observed during the Basic Step on the Core Board fitness device at various levels of stability. The study involved 10 female students. Participants stepped on and off the Core Board 10 times at 3 levels of stability. After completing a series of steps, the Core Board's stability was modified and the participant repeated the whole series. The measurement platform to examine three components of the reaction force (horizontal in the sagittal and frontal planes, and vertical) was used. The ground reaction force (GRF) observed on the Core Board, in the vertical and horizontal components is higher at all three levels of stability than on the platform without the device. Significant differences in GRF were observed in the horizontal component in the frontal plane (Fz) at all three levels of mobility as well as in impulse, measured on platforms with the device. The results on the Core Board training device present highest horizontal ground reaction forces in frontal plane at the highest level of Core Board mobility and this showing little medio-lateral stability and a more reactive way of movement regulation of the participants. As a consequence of the force patterns found it may be suggested that fitness training concepts should focus more possibly higher strains on the locomotor system most likely caused by changed ground reaction force patterns, an idea that has to be further analyzed with more complex measurement approaches.

  19. Ground Reaction Forces Generated by Twenty-eight Hatha Yoga Postures.

    Science.gov (United States)

    Wilcox, Sylvia J; Hager, Ron; Lockhart, Barbara; Seeley, Matthew K

    Adherents claim many benefits from the practice of yoga, including promotion of bone health and prevention of osteoporosis. However, no known studies have investigated whether yoga enhances bone mineral density. Furthermore, none have estimated reaction forces applied by yoga practitioners. The purpose of this study was to collect ground reaction force (GRF) data on a variety of hatha yoga postures that would commonly be practiced in fitness centers or private studios. Twelve female and eight male volunteers performed a sequence of 28 hatha yoga postures while GRF data were collected with an AMTI strain-gauge force platform. The sequence was repeated six times by each study subject. Four dependent variables were studied: peak vertical GRF, mean vertical GRF, peak resultant GRF, and mean resultant GRF. Univariate analysis was used to identify mean values and standard deviations for the dependent variables. Peak vertical and resultant values of each posture were similar for all subjects, and standard deviations were small. Similarly, mean vertical and resultant values were similar for all subjects. This 28 posture yoga sequence produced low impact GRF applied to upper and lower extremities. Further research is warranted to determine whether these forces are sufficient to promote osteogenesis or maintain current bone health in yoga practitioners.

  20. (Environmental investigation of ground water contamination at Wright-Patterson Air Force Base, Ohio)

    Energy Technology Data Exchange (ETDEWEB)

    1992-03-01

    This report presents information related to the sampling of ground water at the Wright-Patterson Air Force Base. It is part of an investigation into possible ground water contamination. Information concerns well drilling/construction; x-ray diffraction and sampling; soil boring logs; and chain-of-custody records.

  1. Forcing factors of cloud-to-ground lightning over Iberia: regional-scale assessments

    Directory of Open Access Journals (Sweden)

    J. A. Santos

    2013-07-01

    Full Text Available Cloud-to-ground lightning in a sector covering the Iberian Peninsula, the Balearic Islands and nearby seas (36–44° N, 10° W–5° E is analysed in the period from 2003 to 2009 (7 yr. Two Iberian lightning detection networks, composed of 18 sensors over Portugal and Spain, are combined for the first time in the present study. The selected characteristics are cloud-to-ground flashes (CGFs, first stroke peak current, polarity and multiplicity (number of strokes in a given flash. This study examines the temporal (on hourly, monthly and seasonal timescales and spatial variability of CGFs. The influence of five forcing factors on lightning (elevation, lifted index, convective available potential energy and daily minimum and maximum near-surface air temperatures over the Iberian sector is also assessed. For regional-scale assessments, six subsectors with different climatic conditions were analysed separately. Despite important regional differences, the strongest lightning activity occurs from late spring to early autumn, and mostly in the afternoon. Furthermore, CGFs are mainly located over high-elevation areas in late spring to summer, while they tend to occur over the sea in autumn. The results suggest that (1 orographically forced thunderstorms over mountainous areas, mostly from May to September, (2 tropospheric buoyancy forcing over western-central and northern regions in summer and over the Mediterranean regions in autumn, and (3 near-surface thermal contrasts from October to February largely control the location of lightning in Iberia. There is no evidence of different forcings by polarity. A clear correspondence between summertime precipitation patterns and CGFs is also found.

  2. The Enemy Below: Preparing Ground Forces for Subterranean Warfare

    Science.gov (United States)

    2013-12-01

    can endanger the lives of U.S. forces and render mechanical breaching tools inoperable. Air blowers can be used as a hasty means to ventilate a... Penguin Books, 1996). 179 Tom Mangold, The Tunnels of Cu Chi (New York, NY: Random House, 1985). 147 6. A Historical Analysis of Tunnel Warfare and... Penguin Group, 1996. 157 Lester, W. G., & Ali, A. J. “Underground Combat: Stereophonic Blasting, tunnel Rats, and the Soviet-Afghan War.” Engineer

  3. The Effects of Opposition and Gender on Knee Kinematics and Ground Reaction Force during Landing from Volleyball Block Jumps

    Science.gov (United States)

    Hughes, Gerwyn; Watkins, James; Owen, Nick

    2010-01-01

    The aim of this study was to examine the effect of opposition and gender on knee kinematics and ground reaction force during landing from a volleyball block jump. Six female and six male university volleyball players performed two landing tasks: (a) an unopposed and (b) an opposed volleyball block jump and landing. A 12-camera motion analysis…

  4. The Effects of Opposition and Gender on Knee Kinematics and Ground Reaction Force during Landing from Volleyball Block Jumps

    Science.gov (United States)

    Hughes, Gerwyn; Watkins, James; Owen, Nick

    2010-01-01

    The aim of this study was to examine the effect of opposition and gender on knee kinematics and ground reaction force during landing from a volleyball block jump. Six female and six male university volleyball players performed two landing tasks: (a) an unopposed and (b) an opposed volleyball block jump and landing. A 12-camera motion analysis…

  5. Automatic classification of pathological gait patterns using ground reaction forces and machine learning algorithms.

    Science.gov (United States)

    Alaqtash, Murad; Sarkodie-Gyan, Thompson; Yu, Huiying; Fuentes, Olac; Brower, Richard; Abdelgawad, Amr

    2011-01-01

    An automated gait classification method is developed in this study, which can be applied to analysis and to classify pathological gait patterns using 3D ground reaction force (GRFs) data. The study involved the discrimination of gait patterns of healthy, cerebral palsy (CP) and multiple sclerosis subjects. The acquired 3D GRFs data were categorized into three groups. Two different algorithms were used to extract the gait features; the GRFs parameters and the discrete wavelet transform (DWT), respectively. Nearest neighbor classifier (NNC) and artificial neural networks (ANN) were also investigated for the classification of gait features in this study. Furthermore, different feature sets were formed using a combination of the 3D GRFs components (mediolateral, anterioposterior, and vertical) and their various impacts on the acquired results were evaluated. The best leave-one-out (LOO) classification accuracy 85% was achieved. The results showed some improvement through the application of a features selection algorithm based on M-shaped value of vertical force and the statistical test ANOVA of mediolateral and anterioposterior forces. The optimal feature set of six features enhanced the accuracy to 95%. This work can provide an automated gait classification tool that may be useful to the clinician in the diagnosis and identification of pathological gait impairments.

  6. Assessment of changes in gait parameters and vertical ground reaction forces after total hip arthroplasty

    Directory of Open Access Journals (Sweden)

    Bhargava P

    2007-01-01

    Full Text Available The principal objectives of arthroplasty are relief of pain and enhancement of range of motion. Currently, postoperative pain and functional capacity are assessed largely on the basis of subjective evaluation scores. Because of the lack of control inherent in this method it is often difficult to interpret data presented by different observers in the critical evaluation of surgical method, new components and modes of rehabilitation. Gait analysis is a rapid, simple and reliable method to assess functional outcome. This study was undertaken in an effort to evaluate the gait characteristics of patients who underwent arthroplasty, using an Ultraflex gait analyzer. Materials and Methods: The study was based on the assessment of gait and weight-bearing pattern of both hips in patients who underwent total hip replacement and its comparison with an age and sex-matched control group. Twenty subjects of total arthroplasty group having unilateral involvement, operated by posterior approach at our institution with a minimum six-month postoperative period were selected. Control group was age and sex-matched, randomly selected from the general population. Gait analysis was done using Ultraflex gait analyzer. Gait parameters and vertical ground reaction forces assessment was done by measuring the gait cycle properties, step time parameters and VGRF variables. Data of affected limb was compared with unaffected limb as well as control group to assess the weight-bearing pattern. Statistical analysis was done by′t′ test. Results: Frequency is reduced and gait cycle duration increased in total arthroplasty group as compared with control. Step time parameters including Step time, Stance time and Single support time are significantly reduced ( P value < .05 while Double support time and Single swing time are significantly increased ( P value < .05 in the THR group. Forces over each sensor are increased more on the unaffected limb of the THR group as compared to

  7. Effect of starting distance on vertical ground reaction forces in the normal dog.

    Science.gov (United States)

    DuLaney, D; Purinton, T; Dookwah, H; Budsberg, S

    2005-01-01

    The purpose of this study was to evaluate the effect of starting distance on the peak vertical force (PVF) and associated vertical impulses (VI) of normal dogs. Five dogs of similar weight and body type were trotted at a velocity of 1.6-2.2 m/s from each of three starting distances; 2, 4, and 6 m, from the first plate in a two plate test field. A total of ten trials were recorded from each starting distance, five left first contacts and five right first contacts. Each ground reaction force (GRF) of interest was evaluated both within and between the three starting distances using a complete block ANOVA. There was not any significant effect of distance found on peak vertical forces in our study. However, distance did affect VI. Forelimb VI generated at a 2 m trot was significantly less than VI generated at a 6 m trot. Neither extreme distance was found to be significantly different than the 4 m VI. The VI of the hind limb was not significantly affected.

  8. A ground reaction force analysis for designing a sustainable energy-harvesting stairway

    Science.gov (United States)

    Puspitarini, Debrina; Suzianti, Amalia; Rasyid, Harun Al; Priscandy, Nabila

    2016-06-01

    There are many issues of how energy is currently generated and consumed. These include the cost of harvesting energy, the ever-growing demand for it, and the ever-decreasing reserve of current most applicable energy resources. Numerous ways to exploit new sustainable potential energy sources have been pursued, one of which is to create an energy-harvester; a device that captures free potential energy, scattered around in its environment, and transform it into another form of energy. Using NPD approach, Puspitarini, Suzianti, and Al Rasyid (2016) has developed a conceptual design of an energy-harvesting device, which includes a selection of product specification options and a gear set layout design. In this study, a mockup was built for the experiment based on those product specification options. The experiment was conducted using AMTI Force Platform, and its results were processed using Factorial Design. This effort is to test which product specification option contributes the most to Ground Reaction Force (GRF) generation. The greater the generated GRF, the greater amount of electricity produced. A theoretical calculation of electromotive force was also conducted based on the experiment result and the gear set layout design. The result of this study was later discussed and used as a basis to develop further the stairway design.

  9. A New Method of Desired Gait Synthesis for Biped Walking Robot Based on Ground Reaction Force

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A new method of desired gait synthesis for biped walking robot based on the ground reaction force was proposed. The relation between the ground reaction force and joint motion is derived using the D'Almbert principle. In view of dynamic walking with high stability, the ZMP(Zero Moment Point)stability criterion must be considered in the desired gait synthesis. After that, the joint trajectories of biped walking robot are decided by substituting the ground reaction force into the aforesaid relation based on the ZMP criterion. The trajectory of desired ZMP is determined by a fuzzy logic based upon the body posture of biped walking robot. The proposed scheme is simulated and experimented on a 10 degree of freedom biped walking robot. The results indicate that the proposed method is feasible.

  10. Effect of firefighter boots and viscoelastic insoles on the impact force of the ground reaction force’s vertical component

    Directory of Open Access Journals (Sweden)

    Jesús Cámara-Tobalina

    2011-12-01

    Full Text Available The aims of the present study were to determine the effect of firefighter's boots on the vertical component of the ground reaction force (GRF at heel strike, also known as heel strike transient and to analyze the effect of the viscoelastic insoles placed into the firefighter’s boots on this force during the gait. The magnitude of the impact force (FZI from the vertical ground reaction force, the time to the production of this force (TZI and the loading rate (GC were registered. 39 firefighters without any pathology during 2 years before the study were recruited. Three different walking conditions were tested: 1 gait with firefighter's boots, 2 gait with firefighter's boots and viscoelastic insoles and 3 gait with sport shoes. The results showed a higher production and magnitude of the impact force during gait with firefighter's boots than during gait with sport shoes (13,1 vs. 2,6 % of occurrence of the impact force and 61,39 ± 35,18 %BW (body weight vs. 49,38 ± 22,99 %BW, respectively. The gait with viscoelastic insoles placed into the firefighter's boots did not show significant differences in any of the parameters characterizing the impact force compared to the gait without insoles. The results of this study show a lower cushioning of the impact force during the gait with firefighter's boots in comparison to the gait with sport shoes and the inefficiency of the viscoelastic insoles placed inside the firefighter's boots to ameliorate the cushioning of the impact force at natural walking speed.

  11. Effects of backpack weight on posture, gait patterns and ground reaction forces of male children with obesity during stair descent.

    Science.gov (United States)

    Song, Qipeng; Yu, Bing; Zhang, Cui; Sun, Wei; Mao, Dewei

    2014-01-01

    This study investigates the effects of backpack weight on posture, gait pattern, and ground reaction forces for children with obesity in an attempt to define a safe backpack weight limit for them. A total of 16 obese (11.19 ± 0.66 years of age) and 21 normal body weight (11.13 ± 0.69 years of age) schoolboys were recruited. Two force plates and two video cameras were used. Multivariate analysis of variance with repeated measures was employed. Obese children showed increased trunk and head forward inclination angle, gait cycle duration and stance phase, decreased swing phase, and increased ground reaction force in the medial-lateral and anterior-posterior directions when compared with male children with a normal body weight. The changes were observed even with an empty backpack in comparison with normal body weight children and a 15% increase in backpack weight led to further instability and damage on their already strained bodies.

  12. Force spectroscopy in studying infection

    CERN Document Server

    Zhou, Zhaokun

    2016-01-01

    Biophysical force spectroscopy tools - for example optical tweezers, magnetic tweezers, atomic force microscopy, - have been used to study elastic, mechanical, conformational and dynamic properties of single biological specimens from single proteins to whole cells to reveal information not accessible by ensemble average methods such as X-ray crystallography, mass spectroscopy, gel electrophoresis and so on. Here we review the application of these tools on a range of infection-related questions from antibody-inhibited protein processivity to virus-cell adhesion. In each case we focus on how the instrumental design tailored to the biological system in question translates into the functionality suitable for that particular study. The unique insights that force spectroscopy has gained to complement knowledge learned through population averaging techniques in interrogating biomolecular details prove to be instrumental in therapeutic innovations such as those in structure-based drug design.

  13. Mechanical stimulation of the foot sole in a supine position for ground reaction force simulation

    OpenAIRE

    2014-01-01

    Background:\\ud To promote early rehabilitation of walking, gait training can start even when patients are on bed rest. Supine stepping in the early phase after injury is proposed to maximise the beneficial effects of gait restoration. In this training paradigm, mechanical loading on the sole of the foot is required to mimic the ground reaction forces that occur during overground walking. A pneumatic shoe platform was developed to produce adjustable forces on the heel and the forefoot with an ...

  14. Structuring U.S. Ground Forces to Meet All Threats

    Science.gov (United States)

    2008-04-30

    79 Martin Samuels , Doctrine and Dogma: German and...83 J.H. Boraston, ed. Sir Douglas Haig Despatches. (London: J.M. Dent and Sons LTD, 1919), 322. 84 Samuels , 149. 85 Edmonds, History of the...Regular Army in 1914,” in A Nation in Arms: A Social Study of the British Army in the First World War, ed. Ian Beckett and Keith Simpson (Manchester

  15. In-Shoe Plantar Pressures and Ground Reaction Forces during Overweight Adults' Overground Walking

    Science.gov (United States)

    de Castro, Marcelo P.; Abreu, Sofia C.; Sousa, Helena; Machado, Leandro; Santos, Rubim; Vilas-Boas, João Paulo

    2014-01-01

    Purpose: Because walking is highly recommended for prevention and treatment of obesity and some of its biomechanical aspects are not clearly understood for overweight people, we compared the absolute and normalized ground reaction forces (GRF), plantar pressures, and temporal parameters of normal-weight and overweight participants during…

  16. Use of pressure insoles to calculate the complete ground reaction forces

    NARCIS (Netherlands)

    Forner Cordero, A.; Koopman, H.F.J.M.; Helm, van der F.C.T.

    2004-01-01

    A method to calculate the complete ground reaction force (GRF) components from the vertical GRF measured with pressure insoles is presented and validated. With this approach it is possible to measure several consecutive steps without any constraint on foot placement and compute a standard inverse dy

  17. Analysis of kinematic data and determination of ground reaction force of foot in slow squat

    Institute of Scientific and Technical Information of China (English)

    Xu-Shu Zhang; Yuan Guo; Mei-Wen An; Wei-Yi Chen

    2013-01-01

    In the present paper,the ground reaction force (GRF) acting on foot in slow squat was determined through a force measuring system,and at the same time,the kinematic data of human squat were obtained by analyzing the photographed image sequences.According to the height and body weight,six healthy volunteers were selected,three men in one group and the other three women in another group,and the fundamental parameters of subjects were recorded,including body weight,height and age,etc.Based on the anatomy characteristics,some markers were placed on the right side of joints.While the subject squatted at slow speed on the force platform,the ground reaction forces on the forefoot and heel for each foot were obtained through calibrated force platform.The analysis results show that the reaction force on heel is greater than that on forefoot,and double feet have nearly constant force.Moreover,from processing and analyzing the synchronously photographed image sequences in squat,the kinematic data of human squat were acquired,including mainly the curves of angle,angular velocity and angular acceleration varied with time for knee,hip and ankle joints in a sagittal plane.The obtained results can offer instructive reference for photographing and analyzing the movements of human bodies,diagnosing some diseases,and establishing in the future appropriate mathematical models for the human motion.

  18. Analysis of kinematic data and determination of ground reaction force of foot in slow squat

    Science.gov (United States)

    Zhang, Xu-Shu; Guo, Yuan; An, Mei-Wen; Chen, Wei-Yi

    2013-02-01

    In the present paper, the ground reaction force (GRF) acting on foot in slow squat was determined through a force measuring system, and at the same time, the kinematic data of human squat were obtained by analyzing the photographed image sequences. According to the height and body weight, six healthy volunteers were selected, three men in one group and the other three women in another group, and the fundamental parameters of subjects were recorded, including body weight, height and age, etc. Based on the anatomy characteristics, some markers were placed on the right side of joints. While the subject squatted at slow speed on the force platform, the ground reaction forces on the forefoot and heel for each foot were obtained through calibrated force platform. The analysis results show that the reaction force on heel is greater than that on forefoot, and double feet have nearly constant force. Moreover, from processing and analyzing the synchronously photographed image sequences in squat, the kinematic data of human squat were acquired, including mainly the curves of angle, angular velocity and angular acceleration varied with time for knee, hip and ankle joints in a sagittal plane. The obtained results can offer instructive reference for photographing and analyzing the movements of human bodies, diagnosing some diseases, and establishing in the future appropriate mathematical models for the human motion.

  19. Locomotion Strategy and Magnitude of Ground Reaction Forces During Treadmill Training on ISS.

    Science.gov (United States)

    Fomina, Elena; Savinkina, Alexandra

    2017-09-01

    Creation of the cosmonaut in-flight physical training process is currently based on the leading role of support afferents in the development of hypogravity changes in the motor system. We assume that the strength of support afferents is related to the magnitude of the ground reaction forces (GRF). For this purpose it was necessary to compare the GRF magnitude on the Russian BD-2 treadmill for different locomotion types (walking and running), modes (active and passive), and subjects. Relative GRF values were analyzed while subjects performed walking and running during active and passive modes of treadmill belt movement under 1 G (N = 6) and 0 G (N = 4) conditions. For different BD-2 modes and both types of locomotion, maximum GRF values varied in both 0 G and 1 G. Considerable individual variations were also found in the locomotion strategies, as well as in maximum GRF values. In 0 G, the smallest GRF values were observed for walking in active mode, and the largest during running in passive mode. In 1 G, GRF values were higher during running than while walking, but the difference between active and passive modes was not observed; we assume this was due to the uniqueness of the GRF profile. The maximum GRF recorded during walking and running in active and passive modes depended on the individual pattern of locomotion. The maximum GRF values that we recorded on BD-2 were close to values found by other researchers. The observations from this study could guide individualized countermeasures prescriptions for microgravity.Fomina E, Savinkina A. Locomotion strategy and magnitude of ground reaction forces during treadmill training on ISS. Aerosp Med Hum Perform. 2017; 88(9):841-849.

  20. A COMPARISON OF GOLF SHOE DESIGNS HIGHLIGHTS GREATER GROUND REACTION FORCES WITH SHORTER IRONS

    Directory of Open Access Journals (Sweden)

    Paul Worsfold

    2007-12-01

    Full Text Available In an effort to reduce golf turf damage the traditional metal spike golf shoe has been redesigned, but shoe-ground biomechanical evaluations have utilised artificial grass surfaces. Twenty-four golfers wore three different golf shoe traction designs (traditional metal spikes, alternative spikes, and a flat-soled shoe with no additional traction when performing shots with a driver, 3 iron and 7 iron. Ground action forces were measured beneath the feet by two natural grass covered force platforms. The maximum vertical force recorded at the back foot with the 3 iron and 7 iron was 0.82 BW (body weight and at the front foot 1.1 BW approximately in both the metal spike and alternative spike golf shoe designs. When using the driver these maximal vertical values were 0.49 BW at the back foot and 0.84 BW at the front foot. Furthermore, as performance of the backswing and then downswing necessitates a change in movement direction the range of force generated during the complete swing was calculated. In the metal spike shoe the vertical force generated at the back foot with both irons was 0.67 BW and at the front foot 0.96 BW with the 3 iron and 0.92 BW with the 7 iron. The back foot vertical force generated with the driver was 0.33 BW and at the front foot 0.83 BW wearing the metal spike shoe. Results indicated the greater force generation with the irons. When using the driver the more horizontal swing plane associated with the longer club reduced vertical forces at the back and front foot. However, the mediolateral force generated across each foot in the metal and alternative spike shoes when using the driver was greater than when the irons were used. The coefficient of friction was 0. 62 at the back and front foot whichever shoe was worn or club used

  1. Effect of short-term fatigue, induced by high-intensity exercise, on the profile of the ground reaction force during single-leg anterior drop-jumps

    Science.gov (United States)

    Watanabe, Saya; Aizawa, Junya; Shimoda, Manabu; Enomoto, Mitsuhiro; Nakamura, Tomomasa; Okawa, Atushi; Yagishita, Kazuyoshi

    2016-01-01

    [Purpose] Fatigue may be an important contributing factor to non-contact anterior cruciate ligament injuries in sports. The purpose of this study was to evaluate the effects of controlled lower limb fatigue, induced by a short-term, high-intensity exercise protocol, on the profile of the ground reaction force during landings from single-leg anterior drop-jumps. [Subjects and Methods] Twelve healthy males, 18 to 24 years old, performed single-leg anterior drop-jumps, from a 20 cm height, under two conditions, ‘fatigue’ and ‘non-fatigue’. Short-term fatigue was induced by high-intensity interval cycling on an ergometer. Effects of fatigue on peak vertical ground reaction force, time-to-peak of the vertical ground reaction force, and loading rate were evaluated by paired t-test. [Results] Fatigue shortened the time-to-peak duration of the vertical ground reaction force by 10% (non-fatigue, 44.0 ± 16.8 ms; fatigue, 39.6 ± 15.8 ms). Fatigue also yielded a 3.6% lowering in peak vertical ground reaction force and 9.4% increase in loading rate, although these effects were not significant. [Conclusion] The effects of fatigue in reducing time-to-peak of the vertical ground reaction force during single-leg anterior drop-jumps may increase the risk for non-contact anterior cruciate ligament injury in males. PMID:28174454

  2. Force Reconnaissance: A Key Enabler in the Marine Air Ground Task Force and Beyond

    Science.gov (United States)

    2012-03-13

    Vietnam – Stingray /Keyhole………………………………………………..........13 MSPF – Direct Action/VBSS……………………………………………………15 OIF/OEF – Direct Action/VBSS/COIN...or “combat patrol.” Based on the leadership of General Lewis Walt (USMC), he led to the establishment of Keyhole and Stingray missions. General Walt...their mission. ( Stingray combat patrols were organized to make contact with enemy forces through ambush or supporting fire. Stingray patrols were

  3. ERA-Interim forced H-TESSEL and WRF schemes for modeling ground

    Science.gov (United States)

    Rocha, M. J.; Dutra, E.; Vieira, G.; Miranda, P.; Fragoso, M.; Ramos, M.

    2009-04-01

    Permafrost is central to the carbon cycle and to the climate system and is recognized by the WCRP/WMO as a key element of the Earth System in which research efforts should focus. Compared with the Arctic, very little is known about the distribution, thickness, and properties of permafrost in the Antarctic. The main reason for this is the scarce network of permafrost temperature monitoring boreholes, as well as the short number of active layer monitoring sites. According to the IPCC in the last decades regions underlain by permafrost have been reduced in extent, and a warming of the ground has been observed in many areas. This study focus on Livingston and Deception Islands (South Shetlands), located in the Antarctic Peninsula region, one of the Earth's regions where warming has been more significant in the last 50 years. Our work is integrated in a project focusing on studying the influence of climate change on permafrost temperatures, which includes systematic and long-term terrain monitoring and also modeling using mesoscale meteorological models. A significant contribution will be the evaluation of the possibilities for using the mesoscale modeling approaches to other areas of the Antarctic Peninsula where no data exist on permafrost temperatures. Climate variability of the Antarctic Peninsula region was studied using the new reanalysis product from ECMWF Era-Interim and observational data from meteorological monitoring sites and boreholes run by our group. Monthly and annual cycles of near surface climate variables are compared. The modeling approach includes the H-TESSEL (Hydrology Tiled ECMWF Scheme for Surface Exchanges over Land) and the WRF (Weather Research and Forecasting), both forced with ERA-Interim for modeling ground temperatures in the study region. Simulations of both land surface and mesoscale models are compared with the observational data of soil temperatures. Preliminary results are presented and show that our approach can provide a good tool

  4. Sagittal Plane Knee Biomechanics and Vertical Ground Reaction Forces Are Modified Following ACL Injury Prevention Programs

    Science.gov (United States)

    Padua, Darin A.; DiStefano, Lindsay J.

    2009-01-01

    Context: Injuries to the anterior cruciate ligament (ACL) occur because of excessive loading on the knee. ACL injury prevention programs can influence sagittal plane ACL loading factors and vertical ground reaction force (VGRF). Objective: To determine the influence of ACL injury prevention programs on sagittal plane knee biomechanics (anterior tibial shear force, knee flexion angle/moments) and VGRF. Data Sources: The PubMed database was searched for studies published between January 1988 and June 2008. Reference lists of selected articles were also reviewed. Study Selection: Studies were included that evaluated healthy participants for knee flexion angle, sagittal plane knee kinetics, or VGRF after performing a multisession training program. Two individuals reviewed all articles and determined which articles met the selection criteria. Approximately 4% of the articles fulfilled the selection criteria. Data Extraction: Data were extracted regarding each program’s duration, frequency, exercise type, population, supervision, and testing procedures. Means and variability measures were recorded to calculate effect sizes. One reviewer extracted all data and assessed study quality using PEDro (Physiotherapy Evidence Database). A second reviewer (blinded) verified all information. Results: There is moderate evidence to indicate that knee flexion angle, external knee flexion moment, and VGRF can be successfully modified by an ACL injury prevention program. Programs utilizing multiple exercises (ie, integrated training) appear to produce the most improvement, in comparison to that of single-exercise programs. Knee flexion angle was improved following integrated training (combined balance and strength exercises or combined plyometric and strength exercises). Similarly, external knee flexion moment was improved following integrated training consisting of balance, plyometric, and strength exercises. VGRF was improved when incorporating supervision with instruction and

  5. Determining the Forces Generated by the Contact of an Electrically-Operated Vehicle with the Ground

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    In this paper we analyse the motion of an electric vehicle,when there is only the pure rolling of the wheels on the ground.The equations of holonomic and non-holonomic constraints have been rendered explicitly obtaining 27 equations algebraic-differential system with the same number of unknowns.Besides,this system supplies a model to calculate the bonding reaction forces.

  6. Estimating youth locomotion ground reaction forces using an accelerometer-based activity monitor.

    Directory of Open Access Journals (Sweden)

    Jennifer M Neugebauer

    Full Text Available To address a variety of questions pertaining to the interactions between physical activity, musculoskeletal loading and musculoskeletal health/injury/adaptation, simple methods are needed to quantify, outside a laboratory setting, the forces acting on the human body during daily activities. The purpose of this study was to develop a statistically based model to estimate peak vertical ground reaction force (pVGRF during youth gait. 20 girls (10.9 ± 0.9 years and 15 boys (12.5 ± 0.6 years wore a Biotrainer AM over their right hip. Six walking and six running trials were completed after a standard warm-up. Average AM intensity (g and pVGRF (N during stance were determined. Repeated measures mixed effects regression models to estimate pVGRF from Biotrainer activity monitor acceleration in youth (girls 10-12, boys 12-14 years while walking and running were developed. Log transformed pVGRF had a statistically significant relationship with activity monitor acceleration, centered mass, sex (girl, type of locomotion (run, and locomotion type-acceleration interaction controlling for subject as a random effect. A generalized regression model without subject specific random effects was also developed. The average absolute differences between the actual and predicted pVGRF were 5.2% (1.6% standard deviation and 9% (4.2% standard deviation using the mixed and generalized models, respectively. The results of this study support the use of estimating pVGRF from hip acceleration using a mixed model regression equation.

  7. Hydrogeology and simulation of ground-water flow at Arnold Air Force Base, Coffee and Franklin counties, Tennessee

    Science.gov (United States)

    Haugh, C.J.; Mahoney, E.N.

    1994-01-01

    The U.S. Air Force at Arnold Air Force Base (AAFB), in Coffee and Franklin Counties, Tennessee, is investigating ground-water contamination in selected areas of the base. This report documents the results of a comprehensive investigation of the regional hydrogeology of the AAFB area. Three aquifers within the Highland Rim aquifer system, the shallow aquifer, the Manchester aquifer, and the Fort Payne aquifer, have been identified in the study area. Of these, the Manchester aquifer is the primary source of water for domestic use. Drilling and water- quality data indicate that the Chattanooga Shale is an effective confining unit, isolating the Highland Rim aquifer system from the deeper, upper Central Basin aquifer system. A regional ground-water divide, approximately coinciding with the Duck River-Elk River drainage divide, underlies AAFB and runs from southwest to northeast. The general direction of most ground-water flow is to the north- west or to the northwest or to the southeast from the divide towards tributary streams that drain the area. Recharge estimates range from 4 to 11 inches per year. Digital computer modeling was used to simulate and provide a better understanding of the ground-water flow system. The model indicates that most of the ground-water flow occurs in the shallow and Manchester aquifers. The model was most sensitive to increases in hydraulic conductivity and changes in recharge rates. Particle-tracking analysis from selected sites of ground-water contamination indicates a potential for contami- nants to be transported beyond the boundary of AAFB.

  8. Gender difference in older adult's utilization of gravitational and ground reaction force in regulation of angular momentum during stair descent.

    Science.gov (United States)

    Singhal, Kunal; Kim, Jemin; Casebolt, Jeffrey; Lee, Sangwoo; Han, Ki-Hoon; Kwon, Young-Hoo

    2015-06-01

    Angular momentum of the body is a highly controlled quantity signifying stability, therefore, it is essential to understand its regulation during stair descent. The purpose of this study was to investigate how older adults use gravity and ground reaction force to regulate the angular momentum of the body during stair descent. A total of 28 participants (12 male and 16 female; 68.5 years and 69.0 years of mean age respectively) performed stair descent from a level walk in a step-over-step manner at a self-selected speed over a custom made three-step staircase with embedded force plates. Kinematic and force data were used to calculate angular momentum, gravitational moment, and ground reaction force moment about the stance foot center of pressure. Women show a significantly greater change in normalized angular momentum (0.92Nms/Kgm; p=.004) as compared to men (0.45Nms/Kgm). Women produce higher normalized GRF (p=.031) during the double support phase. The angular momentum changes show largest backward regulation for Step 0 and forward regulation for Step 2. This greater difference in overall change in the angular momentum in women may explain their increased risk of fall over the stairs.

  9. Squat Ground Reaction Force on a Horizontal Squat Device, Free Weights, and Smith Machine

    Science.gov (United States)

    Scott-Pandorf, Melissa M.; Newby, Nathaniel J.; Caldwell, Erin; DeWitt, John K.; Peters, Brian T.

    2010-01-01

    Bed rest is an analog to spaceflight and advancement of exercise countermeasures is dependent on the development of exercise equipment that closely mimic actual upright exercise. The Horizontal Squat Device (HSD) was developed to allow a supine exerciser to perform squats that mimic upright squat exercise. PURPOSE: To compare vertical ground reaction force (GRFv) on the HSD with Free Weight (FW) or Smith Machine (SM) during squat exercise. METHODS: Subjects (3F, 3M) performed sets of squat exercise with increasing loads up to 1-repetition (rep) maximum. GRF data were collected and compared with previous GRF data for squat exercise performed with FW & SM. Loads on the HSD were adjusted to magnitudes comparable with FW & SM by subtracting the subject s body weight (BW). Peak GRFv for 45-, 55-, 64-, & 73-kg loads above BW were calculated. Percent (%) difference between HSD and the two upright conditions were computed. Effect size was calculated for the 45-kg load. RESULTS: Most subjects were unable to lift >45 kg on the HSD; however, 1 subject completed all loads. Anecdotal evidence suggested that most subjects shoulders or back failed before their legs. The mean % difference are shown. In the 45-kg condition, effect sizes were 0.37 & 0.83 (p>0.05) for HSD vs. FW and HSD vs. SM, respectively, indicating no differences between exercise modes. CONCLUSION: When BW was added to the target load, results indicated that vertical forces were similar to those in FW and SM exercise. The exercise prescription for the HSD should include a total external resistance equivalent to goal load plus subject BW. The HSD may be used as an analog to upright exercise in bed rest studies, but because most subjects were unable to lift >45 kg, it may be necessary to prescribe higher reps and lower loads to better target the leg musculature

  10. Ground reaction force estimates from ActiGraph GT3X+ hip accelerations.

    Directory of Open Access Journals (Sweden)

    Jennifer M Neugebauer

    Full Text Available Simple methods to quantify ground reaction forces (GRFs outside a laboratory setting are needed to understand daily loading sustained by the body. Here, we present methods to estimate peak vertical GRF (pGRFvert and peak braking GRF (pGRFbrake in adults using raw hip activity monitor (AM acceleration data. The purpose of this study was to develop a statistically based model to estimate pGRFvert and pGRFbrake during walking and running from ActiGraph GT3X+ AM acceleration data. 19 males and 20 females (age 21.2 ± 1.3 years, height 1.73 ± 0.12 m, mass 67.6 ± 11.5 kg wore an ActiGraph GT3X+ AM over their right hip. Six walking and six running trials (0.95-2.19 and 2.20-4.10 m/s, respectively were completed. Average of the peak vertical and anterior/posterior AM acceleration (ACCvert and ACCbrake, respectively and pGRFvert and pGRFbrake during the stance phase of gait were determined. Thirty randomly selected subjects served as the training dataset to develop generalized equations to predict pGRFvert and pGRFbrake. Using a holdout approach, the remaining 9 subjects were used to test the accuracy of the models. Generalized equations to predict pGRFvert and pGRFbrake included ACCvert and ACCbrake, respectively, mass, type of locomotion (walk or run, and type of locomotion acceleration interaction. The average absolute percent differences between actual and predicted pGRFvert and pGRFbrake were 8.3% and 17.8%, respectively, when the models were applied to the test dataset. Repeated measures generalized regression equations were developed to predict pGRFvert and pGRFbrake from ActiGraph GT3X+ AM acceleration for young adults walking and running. These equations provide a means to estimate GRFs without a force plate.

  11. External Load Affects Ground Reaction Force Parameters Non-uniformly during Running in Weightlessness

    Science.gov (United States)

    DeWitt, John; Schaffner, Grant; Laughlin, Mitzi; Loehr, James; Hagan, R. Donald

    2004-01-01

    Long-term exposure to microgravity induces detrimefits to the musculcskdetal system (Schneider et al., 1995; LeBlanc et al., 2000). Treadmill exercise is used onboard the International Space Station as an exercise countermeasure to musculoskeletal deconditioning due to spaceflight. During locomotive exercise in weightlessness (0G), crewmembers wear a harness attached to an external loading mechanism (EL). The EL pulls the crewmember toward the treadmill, and provides resistive load during the impact and propulsive phases of gait. The resulting forces may be important in stimulating bone maintenance (Turner, 1998). The EL can be applied via a bungee and carabineer clip configuration attached to the harness and can be manipulated to create varying amounts of load levels during exercise. Ground-based research performed using a vertically mounted treadmill found that peak ground reaction forces (GRF) during running at an EL of less than one body weight (BW) are less than those that occur during running in normal gravity (1G) (Davis et al., 1996). However, it is not known how the GRF are affected by the EL in a true OG environment. Locomotion while suspended may result in biomechanics that differ from free running. The purpose of this investigation was to determine how EL affects peak impact force, peak propulsive force, loading rate, and impulse of the GRF during running in 0G. It was hypothesized that increasing EL would result in increases in each GRF parameter.

  12. Isokinetic analysis of ankle and ground reaction forces in runners and triathletes

    Directory of Open Access Journals (Sweden)

    Natália Mariana Silva Luna

    2012-09-01

    Full Text Available OBJECTIVE: To analyze and compare the vertical component of ground reaction forces and isokinetic muscle parameters for plantar flexion and dorsiflexion of the ankle between long-distance runners, triathletes, and nonathletes. METHODS: Seventy-five males with a mean age of 30.26 (±6.5 years were divided into three groups: a triathlete group (n=26, a long-distance runner group (n = 23, and a non-athlete control group. The kinetic parameters were measured during running using a force platform, and the isokinetic parameters were measured using an isokinetic dynamometer. RESULTS: The non-athlete control group and the triathlete group exhibited smaller vertical forces, a greater ground contact time, and a greater application of force during maximum vertical acceleration than the long-distance runner group. The total work (180º/s was greater in eccentric dorsiflexion and concentric plantar flexion for the non-athlete control group and the triathlete group than the long-distance runner group. The peak torque (60º/s was greater in eccentric plantar flexion and concentric dorsiflexion for the control group than the athlete groups. CONCLUSIONS: The athlete groups exhibited less muscle strength and resistance than the control group, and the triathletes exhibited less impact and better endurance performance than the runners.

  13. Estimation of ground reaction force and zero moment point on a powered ankle-foot prosthesis.

    Science.gov (United States)

    Martinez-Villalpando, Ernesto C; Herr, Hugh; Farrell, Matthew

    2007-01-01

    The ground reaction force (GRF) and the zero moment point (ZMP) are important parameters for the advancement of biomimetic control of robotic lower-limb prosthetic devices. In this document a method to estimate GRF and ZMP on a motorized ankle-foot prosthesis (MIT Powered Ankle-Foot Prosthesis) is presented. The method proposed is based on the analysis of data collected from a sensory system embedded in the prosthetic device using a custom designed wearable computing unit. In order to evaluate the performance of the estimation methods described, standing and walking clinical studies were conducted on a transtibial amputee. The results were statistically compared to standard analysis methodologies employed in a gait laboratory. The average RMS error and correlation factor were calculated for all experimental sessions. By using a static analysis procedure, the estimation of the vertical component of GRF had an averaged correlation coefficient higher than 0.94. The estimated ZMP location had a distance error of less than 1 cm, equal to 4% of the anterior-posterior foot length or 12% of the medio-lateral foot width.

  14. A wearable force plate system for the continuous measurement of triaxial ground reaction force in biomechanical applications

    Science.gov (United States)

    Liu, Tao; Inoue, Yoshio; Shibata, Kyoko

    2010-08-01

    The ambulatory measurement of ground reaction force (GRF) and human motion under free-living conditions is convenient, inexpensive and never restricted to gait analysis in a laboratory environment and is therefore much desired by researchers and clinical doctors in biomedical applications. A wearable force plate system was developed by integrating small triaxial force sensors and three-dimensional (3D) inertial sensors for estimating dynamic triaxial GRF in biomechanical applications. The system, in comparison to existent systems, is characterized by being lightweight, thin and easy-to-wear. A six-axial force sensor (Nitta Co., Japan) was used as a verification measurement device to validate the static accuracy of the developed force plate. To evaluate the precision during dynamic gait measurements, we compared the measurements of the triaxial GRF and the center of pressure (CoP) by using the developed system with the reference measurements made using a stationary force plate and an optical motion analysis system. The root mean square (RMS) differences of the two transverse components (x- and y-axes) and the vertical component (z-axis) of the GRF were 4.3 ± 0.9 N, 6.0 ± 1.3 N and 12.1 ± 1.1 N, respectively, corresponding to 5.1 ± 1.1% and 6.5 ± 1% of the maximum of each transverse component and 1.3 ± 0.2% of the maximum vertical component of GRF. The RMS distance between the two systems' CoP traces was 3.2 ± 0.8 mm, corresponding to 1.2 ± 0.3% of the length of the shoe. Moreover, based on the results of the assessment of the influence of the system on natural gait, we found that gait was almost never affected. Therefore, the wearable system as an alternative device can be a potential solution for measuring CoP and triaxial GRF in non-laboratory environments.

  15. Principal component analysis in ground reaction forces and center of pressure gait waveforms of people with transfemoral amputation.

    Science.gov (United States)

    Soares, Denise Paschoal; de Castro, Marcelo Peduzzi; Mendes, Emilia Assunção; Machado, Leandro

    2016-12-01

    The alterations in gait pattern of people with transfemoral amputation leave them more susceptible to musculoskeletal injury. Principal component analysis is a method that reduces the amount of gait data and allows analyzing the entire waveform. To use the principal component analysis to compare the ground reaction force and center of pressure displacement waveforms obtained during gait between able-bodied subjects and both limbs of individuals with transfemoral amputation. This is a transversal study with a convenience sample. We used a force plate and pressure plate to record the anterior-posterior, medial-lateral and vertical ground reaction force, and anterior-posterior and medial-lateral center of pressure positions of 12 participants with transfemoral amputation and 20 able-bodied subjects during gait. The principal component analysis was performed to compare the gait waveforms between the participants with transfemoral amputation and the able-bodied individuals. The principal component analysis model explained between 74% and 93% of the data variance. In all ground reaction force and center of pressure waveforms relevant portions were identified; and always at least one principal component presented scores statistically different (p amputation compared to the able-bodied participants. Principal component analysis reduced the amount of data, allowed analyzing the whole waveform, and identified specific sub-phases of gait that were different between the groups. Therefore, this approach seems to be a powerful tool to be used in gait evaluation and following the rehabilitation status of people with transfemoral amputation. © The International Society for Prosthetics and Orthotics 2015.

  16. Adaptive method for real-time gait phase detection based on ground contact forces.

    Science.gov (United States)

    Yu, Lie; Zheng, Jianbin; Wang, Yang; Song, Zhengge; Zhan, Enqi

    2015-01-01

    A novel method is presented to detect real-time gait phases based on ground contact forces (GCFs) measured by force sensitive resistors (FSRs). The traditional threshold method (TM) sets a threshold to divide the GCFs into on-ground and off-ground statuses. However, TM is neither an adaptive nor real-time method. The threshold setting is based on body weight or the maximum and minimum GCFs in the gait cycles, resulting in different thresholds needed for different walking conditions. Additionally, the maximum and minimum GCFs are only obtainable after data processing. Therefore, this paper proposes a proportion method (PM) that calculates the sums and proportions of GCFs wherein the GCFs are obtained from FSRs. A gait analysis is then implemented by the proposed gait phase detection algorithm (GPDA). Finally, the PM reliability is determined by comparing the detection results between PM and TM. Experimental results demonstrate that the proposed PM is highly reliable in all walking conditions. In addition, PM could be utilized to analyze gait phases in real time. Finally, PM exhibits strong adaptability to different walking conditions.

  17. The analysis of three-dimensional ground reaction forces during gait in children with autism spectrum disorders.

    Science.gov (United States)

    Hasan, C Z C; Jailani, Rozita; Md Tahir, N; Ilias, Suryani

    2017-03-08

    Minimal information is known about the three-dimensional (3D) ground reaction forces (GRF) on the gait patterns of individuals with autism spectrum disorders (ASD). The purpose of this study was to investigate whether the 3D GRF components differ significantly between children with ASD and the peer controls. 15 children with ASD and 25 typically developing (TD) children had participated in the study. Two force plates were used to measure the 3D GRF data during walking. Time-series parameterization techniques were employed to extract 17 discrete features from the 3D GRF waveforms. By using independent t-test and Mann-Whitney U test, significant differences (p<0.05) between the ASD and TD groups were found for four GRF features. Children with ASD demonstrated higher maximum braking force, lower relative time to maximum braking force, and lower relative time to zero force during mid-stance. Children with ASD were also found to have reduced the second peak of vertical GRF in the terminal stance. These major findings suggest that children with ASD experience significant difficulties in supporting their body weight and endure gait instability during the stance phase. The findings of this research are useful to both clinicians and parents who wish to provide these children with appropriate treatments and rehabilitation programs.

  18. Lower Extremity Kinematics and Ground Reaction Forces After Prophylactic Lace-Up Ankle Bracing

    Science.gov (United States)

    DiStefano, Lindsay J; Padua, Darin A; Brown, Cathleen N; Guskiewicz, Kevin M

    2008-01-01

    Context: Long-term effects of ankle bracing on lower extremity kinematics and kinetics are unknown. Ankle motion restriction may negatively affect the body's ability to attenuate ground reaction forces (GRFs). Objective: To evaluate the immediate and long-term effects of ankle bracing on lower extremity kinematics and GRFs during a jump landing. Design: Experimental mixed model (2 [group] × 2 [brace] × 2 [time]) with repeated measures. Setting: Sports medicine research laboratory. Patients or Other Participants: A total of 37 healthy subjects were assigned randomly to either the intervention (n  =  11 men, 8 women; age  =  19.63 ± 0.72 years, height  =  176.05 ± 10.58 cm, mass  =  71.50 ± 13.15 kg) or control group (n  =  11 men, 7 women; age  =  19.94 ± 1.44 years, height  =  179.15 ± 8.81 cm, mass  =  74.10 ± 10.33 kg). Intervention(s): The intervention group wore braces on both ankles and the control group did not wear braces during all recreational activities for an 8-week period. Main Outcome Measure(s): Initial ground contact angles, maximum joint angles, time to reach maximum joint angles, and joint range of motion for sagittal-plane knee and ankle motion were measured during a jump-landing task. Peak vertical GRF and the time to reach peak vertical GRF were assessed also. Results: While participants were wearing the brace, ankle plantar flexion at initial ground contact (brace  =  35° ± 13°, no brace  =  38° ± 15°, P  =  .024), maximum dorsiflexion (brace  =  21° ± 7°, no brace  =  22° ± 6°, P  =  .04), dorsiflexion range of motion (brace  =  56° ± 14°, no brace  =  59° ± 16°, P  =  .001), and knee flexion range of motion (brace  =  79° ± 16°, no brace  =  82° ± 16°, P  =  .036) decreased, whereas knee flexion at initial ground contact increased (brace  =  12° ± 9°, no brace  =  9° ± 9°, P  =  .0001). Wearing the brace for 8

  19. Ground-based measurements of aerosol optical properties and radiative forcing in North China

    Institute of Scientific and Technical Information of China (English)

    Hongbin Chen; Xiangao Xia; Pucai Wang; Wenxing Zhang

    2007-01-01

    In order to gain an insight into the aerosol properties and their climatic effect over the continental source regions of China, it is of significance to carry out long-term ground-based measurements of aerosol optical properties and radiative forcing. A couple of temporary and permanent Aerosol Robotic Network (AERONET) sites and three comprehensive radiative sites were established in China as a result of international cooperation in recent years. Heavy aerosol loading and significant temporal and spatial variation over North China are revealed by the AERONET data.Aerosol-induced reductions in surface radiation budget are examined on the basis of collocated observations by sun photometers and pyranometers.

  20. (Environmental investigation of ground water contamination at Wright- Patterson Air Force Base, Ohio)

    Energy Technology Data Exchange (ETDEWEB)

    1991-10-01

    This Health and Safety Plan (HSP) was developed for the Environmental Investigation of Ground-water Contamination Investigation at Wright-Patterson Air Force Base near Dayton, Ohio, based on the projected scope of work for the Phase 1, Task 4 Field Investigation. The HSP describes hazards that may be encountered during the investigation, assesses the hazards, and indicates what type of personal protective equipment is to be used for each task performed. The HSP also addresses the medical monitoring program, decontamination procedures, air monitoring, training, site control, accident prevention, and emergency response.

  1. NUMBER OF TRIALS NECESSARY TO ACHIEVE PERFORMANCE STABILITY OF SELECTED GROUND REACTION FORCE VARIABLES DURING LANDING

    Directory of Open Access Journals (Sweden)

    C. Roger James

    2007-03-01

    Full Text Available The objectives were to determine the number of trials necessary to achieve performance stability of selected ground reaction force (GRF variables during landing and to compare two methods of determining stability. Ten subjects divided into two groups each completed a minimum of 20 drop or step-off landings from 0.60 or 0.61 m onto a force platform (1000 Hz. Five vertical GRF variables (first and second peaks, average loading rates to these peaks, and impulse were quantified during the initial 100 ms post-contact period. Test-retest reliability (stability was determined using two methods: (1 intra-class correlation coefficient (ICC analysis, and (2 sequential averaging analysis. Results of the ICC analysis indicated that an average of four trials (mean 3.8 ± 2.7 Group 1; 3.6 ± 1.7 Group 2 were necessary to achieve maximum ICC values. Maximum ICC values ranged from 0.55 to 0.99 and all were significantly (p < 0. 05 different from zero. Results of the sequential averaging analysis revealed that an average of 12 trials (mean 11.7 ± 3.1 Group 1; 11.5 ± 4.5 Group 2 were necessary to achieve performance stability using criteria previously reported in the literature. Using 10 reference trials, the sequential averaging technique required standard deviation criterion values of 0.60 and 0.49 for Groups 1 and 2, respectively, in order to approximate the ICC results. The results of the study suggest that the ICC might be a less conservative, but more objective method for determining stability, especially when compared to previous applications of the sequential averaging technique. Moreover, criteria for implementing the sequential averaging technique can be adjusted so that results closely approximate the results from ICC. In conclusion, subjects in landing experiments should perform a minimum of four and possibly as many as eight trials to achieve performance stability of selected GRF variables. Researchers should use this information to plan future

  2. Case study on ground water flow (8)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-02-01

    The report comprises research activities made in fiscal year 1997 under the contract of Japan Nuclear Fuel Cycle Development Center and the main items are: (1) Evaluation of water permeability through discontinuous hard bedrock in deep strata in relevant with underground disposal of radioactive wastes, (2) Three dimensional analysis of permeated water in bedrock, including flow analysis in T ono district using neuro-network and modification of Evaporation Logging System, (3) Development of hydraulic tests and necessary equipment applicable to measurements of complex dielectric constants of contaminated soils using FUDR-V method, this giving information on soil component materials, (4) Investigation methods and modeling of hydraulics in deep strata, (5) Geological study of ground water using environmental isotopes such as {sup 14}C, {sup 36}Cl and {sup 4}He, particularly measurement of ages of ground water using an accelerator-mass spectrometer, and (6) Re-submerging phenomena affecting the long-term geological stability. (S. Ohno)

  3. Case study on ground water flow (8)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-02-01

    The report comprises research activities made in fiscal year 1997 under the contract of Japan Nuclear Fuel Cycle Development Center and the main items are: (1) Evaluation of water permeability through discontinuous hard bedrock in deep strata in relevant with underground disposal of radioactive wastes, (2) Three dimensional analysis of permeated water in bedrock, including flow analysis in T ono district using neuro-network and modification of Evaporation Logging System, (3) Development of hydraulic tests and necessary equipment applicable to measurements of complex dielectric constants of contaminated soils using FUDR-V method, this giving information on soil component materials, (4) Investigation methods and modeling of hydraulics in deep strata, (5) Geological study of ground water using environmental isotopes such as {sup 14}C, {sup 36}Cl and {sup 4}He, particularly measurement of ages of ground water using an accelerator-mass spectrometer, and (6) Re-submerging phenomena affecting the long-term geological stability. (S. Ohno)

  4. Self-Described Differences Between Legs in Ballet Dancers: Do They Relate to Postural Stability and Ground Reaction Force Measures?

    Science.gov (United States)

    Mertz, Laura; Docherty, Carrie

    2012-12-01

    Ballet technique classes are designed to train dancers symmetrically, but they may actually create a lateral bias. It is unknown whether dancers in general are functionally asymmetrical, or how an individual dancer's perceived imbalance between legs might manifest itself. The purpose of this study was to examine ballet dancers' lateral preference by analyzing their postural stability and ground reaction forces in fifth position when landing from dance-specific jumps. Thirty university ballet majors volunteered to participate in this study. The subjects wore their own ballet technique shoes and performed fundamental ballet jumps out of fifth position on a force plate. The force plate recorded center of pressure (COP) and ground reaction force (GRF) data. Each subject completed a laterality questionnaire that determined his or her preferred landing leg for ballet jumps, self-identified stronger leg, and self-identified leg with better balance. All statistical comparisons were made between the leg indicated on the laterality questionnaire and the other leg (i.e., if the dancer's response to a question was "left," the comparison was made with the left leg as the "preferred" leg and the right leg as the "non-preferred leg"). No significant differences were identified between the limbs in any of the analyses conducted (all statistical comparisons produced p values > 0.05). The results of this study indicate that a dancer's preferential use of one limb over the other has no bearing on GRFs or balance ability after landing jumps in ballet. Similarly, dancers' opinions of their leg characteristics (such as one leg being stronger than the other) seem not to correlate with the dancers' actual ability to absorb GRFs or to balance when landing from ballet jumps.

  5. Estimation of sitting posture by using the combination of ground reaction force

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Hye Ob; Park, Suk Yung [KAIST, Daejeon (Korea, Republic of)

    2015-04-15

    To avoid back pain and related diseases, an appropriate sitting posture should be maintained. Inertial measurement units (IMUs) or marker-less motion cameras, such as Kinect, has recently been used to achieve simpler posture measurements than optical motion capture camera systems. However, multiple IMUs can affect the natural posture of users. The space requirement to guarantee reliable camera data is also somewhat excessive (>1 m) for some personal space setups. Therefore, we propose an unobtrusive method for estimating sitting posture on the basis of ground reaction force measurement, which can be achieved without the use of markers or additional space for measurement. To eliminate additional measurement information other than the ground reaction force underneath the chair and desk, we modeled the posture as a multi-segment rigid body. Several assumptions were proposed and verified to simplify the model and data processing without deteriorating the posture information. Furthermore, to examine whether the combined GRF information provides the appropriateness of the posture, we performed sitting tests for various postures. Results showed that the combinations of GRF measurement could reasonably estimate the sitting posture by the simplified rigid body model and could reliably differentiate the inappropriate forward bent posture. The results showed that the proposed method could serve as a sensing mechanism of posture monitoring systems.

  6. Investigation of spinal posture signatures and ground reaction forces during landing in elite female gymnasts.

    Science.gov (United States)

    Wade, Melanie; Campbell, Amity; Smith, Anne; Norcott, Joanne; O'Sullivan, Peter

    2012-12-01

    The link between static and dynamic landing lumbar postures, when gymnasts are exposed to large ground reaction forces, has not been established. This investigation aimed to (a) determine if a relationship exists between sagittal static and dynamic landing lumbar spine angles at peak ground reaction force (GRF) and (b) quantify how close to end-range postures the gymnasts were at landing peak GRF. Twenty-one female gymnasts' upper and lower lumbar spine angles were recorded: statically in sitting and standing, during landing of three gymnastic skills, and during active end-range lumbar flexion. Pearson's correlations were used to investigate relationships between the angles in different postures. Significant correlations (r = .77-.89, p postures in the lower lumbar spine angle, while fewer and less significant upper lumbar spine correlations were reported. Thirty percent of gymnasts landed a backsault with their lower lumbar spine flexed beyond their active end-range while experiencing GRF 6.8-13.3 times their body weight. These results inform low back pain prevention and management strategies in this population and highlight areas for future research.

  7. "Emergence" vs. "Forcing" of Empirical Data? A Crucial Problem of "Grounded Theory" Reconsidered

    Directory of Open Access Journals (Sweden)

    Udo Kelle

    2005-05-01

    Full Text Available Since the late 1960s Barney GLASER and Anselm STRAUSS, developers of the methodology of "Grounded Theory" have made several attempts to explicate, clarify and reconceptualise some of the basic tenets of their methodological approach. Diverging concepts and understandings of Grounded Theory have arisen from these attempts which have led to a split between its founders. Much of the explication and reworking of Grounded Theory surrounds the relation between data and theory and the role of previous theoretical assumptions. The book which initially established the popularity of GLASER's and STRAUSS' methodological ideas, "The Discovery of Grounded Theory", contains two conflicting understandings of the relation between data and theory—the concept of "emergence" on the one hand and the concept of "theoretical sensitivity" on the other hand. Much of the later developments of Grounded Theory can be seen as attempts to reconcile these prima facie diverging concepts. Thereby GLASER recommends to draw on a variety of "coding families" while STRAUSS proposes the use of a general theory of action to build an axis for an emerging theory. This paper first summarises the most important developments within "Grounded Theory" concerning the understanding of the relation between empirical data and theoretical statements. Thereby special emphasis will be laid on differences between GLASER's and STRAUSS' concepts and on GLASER's current critique that the concepts of "coding paradigm" and "axial coding" described by STRAUSS and Juliet CORBIN lead to the "forcing" of data. It will be argued that GLASER's critique points out some existing weaknesses of STRAUSS' concepts but vastly exaggerates the risks of the STRAUSSian approach. A main argument of this paper is that basic problems of empirically grounded theory construction can be treated much more effectively if one draws on certain results of contemporary philosophical and epistemological discussions and on widely

  8. (Environmental investigation of ground water contamination at Wright-Patterson Air Force Base, Ohio)

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, Bill

    1991-10-01

    In April 1990, Wright-Patterson Air Force Base (WPAFB), initiated an investigation to evaluate a potential Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) removal action to prevent, to the extent practicable, the offsite migration of contaminated ground water from WPAFB. WPAFB retained the services of the Environmental Management Operations (EMO) and its principle subcontractor, International Technology Corporation (IT) to complete Phase 1 of the environmental investigation of ground-water contamination at WPAFB. Phase 1 of the investigation involves the short-term evaluation and potential design for a program to remove ground-water contamination that appears to be migrating across the western boundary of Area C, and across the northern boundary of Area B along Springfield Pike. Primarily, Task 4 of Phase 1 focuses on collection of information at the Area C and Springfield Pike boundaries of WPAFB. This Sampling and Analysis Plan (SAP) has been prepared to assist in completion of the Task 4 field investigation and is comprised of the Quality Assurance Project Plan (QAPP) and the Field Sampling Plan (FSP).

  9. Effects of Prophylactic Ankle Supports on Vertical Ground Reaction Force During Landing: A Meta-Analysis

    Directory of Open Access Journals (Sweden)

    Wenxin Niu, Tienan Feng, Lejun Wang, Chenghua Jiang, Ming Zhang

    2016-03-01

    Full Text Available There has been much debate on how prophylactic ankle supports (PASs may influence the vertical ground reaction force (vGRF during landing. Therefore, the primary aims of this meta-analysis were to systematically review and synthesize the effect of PASs on vGRF, and to understand how PASs affect vGRF peaks (F1, F2 and the time from initial contact to peak loading (T1, T2 during landing. Several key databases, including Scopus, Cochrane, Embase, PubMed, ProQuest, Medline, Ovid, Web of Science, and the Physical Activity Index, were used for identifying relevant studies published in English since inception to April 1, 2015. The computerized literature search and cross-referencing the citation list of the articles yielded 3,993 articles. Criteria for inclusion required that 1 the study was conducted on healthy adults; 2 the subject number and trial number were known; 3 the subjects performed landing with and without PAS; 4 the landing movement was in the sagittal plane; 5 the comparable vGRF parameters were reported; and 6 the F1 and F2 must be normalized to the subject’s body weight. After the removal of duplicates and irrelevant articles, 6, 6, 15 and 11 studies were respectively pooled for outcomes of F1, T1, F2 and T2. This study found a significantly increased F2 (.03 BW, 95% CI: .001, .05 and decreased T1 (-1.24 ms, 95% CI: -1.77, -.71 and T2 (-3.74 ms, 95% CI: -4.83, -2.65 with the use of a PAS. F1 was not significantly influenced by the PAS. Heterogeneity was present in some results, but there was no evidence of publication bias for any outcome. These changes represented deterioration in the buffering characteristics of the joint. An ideal PAS design should limit the excessive joint motion of ankle inversion, while allowing a normal range of motion, especially in the sagittal plane.

  10. Modeling of ground temperatures in South Shetlands (Antarctic Peninsula): Forcing a land surface model with the reanalysis ERA-Interim

    Science.gov (United States)

    João Rocha, Maria; Dutra, Emanuel; Vieira, Gonçalo; Miranda, Pedro; Ramos, Miguel

    2010-05-01

    This study focus on Livingston Island (South Shetlands Antarctic Peninsula), one of the Earth's regions where warming has been more significant in the last 50 years. Our work is integrated in a project focusing on studying the influence of climate change on permafrost temperatures, which includes systematic and long-term terrain monitoring and also modeling using land surface models. A contribution will be the evaluation of the possibilities for using land surface modeling approaches to areas of the Antarctic Peninsula with lack of data on observational meteorological forcing data, as well as on permafrost temperatures. The climate variability of the Antarctic Peninsula region was studied using the new reanalysis product from European Centre for Medium-Range Weather Forecasts (ECMWF) Era-Interim and observational data from boreholes run by our group. Monthly and annual cycles of near surface climate variables are compared. The modeling approach includes the HTESSEL (Hydrology Tiled ECMWF Scheme for Surface Exchanges over Land) forced with ERA-Interim for modeling ground temperatures in the study region. The simulation results of run of HTESSEL are compared against soil temperature observations. The results show a favorable match between simulated and observed soil temperatures. The use of different forcing parameters is compared and the model vs. observation results from different results is analyzed. The main variable needing further improvement in the modeling is snow cover. The developed methodology provides a good tool for the analysis of the influence of climate variability on permafrost of the Maritime Antarctic.

  11. 2D study of wind forces around multiple cooling towers using ...

    African Journals Online (AJOL)

    user

    2D study of wind forces around multiple cooling towers using computational ... Due to the complexity of wind turbulence near ground (Atmospheric Boundary. Layer), the .... In the past, before the computer revolution, the analysis used to be.

  12. Machine learning techniques for gait biometric recognition using the ground reaction force

    CERN Document Server

    Mason, James Eric; Woungang, Isaac

    2016-01-01

    This book focuses on how machine learning techniques can be used to analyze and make use of one particular category of behavioral biometrics known as the gait biometric. A comprehensive Ground Reaction Force (GRF)-based Gait Biometrics Recognition framework is proposed and validated by experiments. In addition, an in-depth analysis of existing recognition techniques that are best suited for performing footstep GRF-based person recognition is also proposed, as well as a comparison of feature extractors, normalizers, and classifiers configurations that were never directly compared with one another in any previous GRF recognition research. Finally, a detailed theoretical overview of many existing machine learning techniques is presented, leading to a proposal of two novel data processing techniques developed specifically for the purpose of gait biometric recognition using GRF. This book · introduces novel machine-learning-based temporal normalization techniques · bridges research gaps concerning the effect of ...

  13. Metabolic Rate and Ground Reaction Force During Motorized and Non-Motorized Treadmill Exercise

    Science.gov (United States)

    Everett, Meghan E.; Loehr, James A.; DeWitt, John K.; Laughlin, Mitzi; Lee, Stuart M. C.

    2010-01-01

    PURPOSE: To measure vertical ground reaction force (vGRF) and oxygen consumption (VO2) at several velocities during exercise using a ground-based version of the ISS treadmill in the M and NM modes. METHODS: Subjects (n = 20) walked or ran at 0.89, 1.34, 1.79, 2.24, 2.68, and 3.12 m/s while VO2 and vGRF data were collected. VO2 was measured using open-circuit spirometry (TrueOne 2400, Parvo-Medics). Data were averaged over the last 2 min of each 5-min stage. vGRF was measured in separate 15-s bouts at 125 Hz using custom-fitted pressure-sensing insoles (F-Scan Sport Sensors, Tekscan, Inc). A repeated-measures ANOVA was used to test for differences in VO2 and vGRF between M and NM and across speeds. Significance was set at P < 0.05. RESULTS: Most subjects were unable to exercise for 5 min at treadmill speeds above 1.79 m/s in the NM mode; however, vGRF data were obtained for all subjects at each speed in both modes. VO2 was approx.40% higher during NM than M exercise across treadmill speeds. vGRF increased with treadmill speed but was not different between modes. CONCLUSION: Higher VO2 with no change in vGRF suggests that the additional metabolic cost associated with NM treadmill exercise is accounted for in the horizontal forces required to move the treadmill belt. Although this may limit the exercise duration at faster speeds, high-intensity NM exercise activates the hamstrings and plantarflexors, which are not specifically targeted or well protected by other in-flight countermeasures.

  14. Pooling sexes when assessing ground reaction forces during walking: Statistical Parametric Mapping versus traditional approach.

    Science.gov (United States)

    Castro, Marcelo P; Pataky, Todd C; Sole, Gisela; Vilas-Boas, Joao Paulo

    2015-07-16

    Ground reaction force (GRF) data from men and women are commonly pooled for analyses. However, it may not be justifiable to pool sexes on the basis of discrete parameters extracted from continuous GRF gait waveforms because this can miss continuous effects. Forty healthy participants (20 men and 20 women) walked at a cadence of 100 steps per minute across two force plates, recording GRFs. Two statistical methods were used to test the null hypothesis of no mean GRF differences between sexes: (i) Statistical Parametric Mapping-using the entire three-component GRF waveform; and (ii) traditional approach-using the first and second vertical GRF peaks. Statistical Parametric Mapping results suggested large sex differences, which post-hoc analyses suggested were due predominantly to higher anterior-posterior and vertical GRFs in early stance in women compared to men. Statistically significant differences were observed for the first GRF peak and similar values for the second GRF peak. These contrasting results emphasise that different parts of the waveform have different signal strengths and thus that one may use the traditional approach to choose arbitrary metrics and make arbitrary conclusions. We suggest that researchers and clinicians consider both the entire gait waveforms and sex-specificity when analysing GRF data. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. An individual and dynamic Body Segment Inertial Parameter validation method using ground reaction forces.

    Science.gov (United States)

    Hansen, Clint; Venture, Gentiane; Rezzoug, Nasser; Gorce, Philippe; Isableu, Brice

    2014-05-01

    Over the last decades a variety of research has been conducted with the goal to improve the Body Segment Inertial Parameters (BSIP) estimations but to our knowledge a real validation has never been completely successful, because no ground truth is available. The aim of this paper is to propose a validation method for a BSIP identification method (IM) and to confirm the results by comparing them with recalculated contact forces using inverse dynamics to those obtained by a force plate. Furthermore, the results are compared with the recently proposed estimation method by Dumas et al. (2007). Additionally, the results are cross validated with a high velocity overarm throwing movement. Throughout conditions higher correlations, smaller metrics and smaller RMSE can be found for the proposed BSIP estimation (IM) which shows its advantage compared to recently proposed methods as of Dumas et al. (2007). The purpose of the paper is to validate an already proposed method and to show that this method can be of significant advantage compared to conventional methods.

  16. Reproducibility of the spatio-temporal variables and the ground reaction forces walking with fire fighting boots

    Directory of Open Access Journals (Sweden)

    Jesús Cámara Tobalina

    2010-11-01

    Full Text Available AbstractThe aim of this study is to analyze the reproducibility of the spatio-temporal variables and the ground reaction forces (GRF when walking with fire fighting boots in comparison to walking with low calf shoes. Spatio-temporal parameters and the variables related to the three components of the GRF of 39 people were recorded under two different walking conditions. A T-test to contrast the difference between the coefficients of variation (CV in both conditions was used. The CV of the spatio-temporal variables (i.e velocity (V, condition I = 2.01%; condition II = 1.81%, of the vertical (i.e. contact force (FZA of the left foot, condition I = 2.54%; condition II = 2.73% and of the antero-posterior GRF (i.e. maximum force (FXMAX of the left foot, condition I = 4.47%; condition II = 4.59% was lower than 12.5%, suggesting that these variables could be used to analyze the influence of fire fighting boots on the gait. However, the low reproducibility showed by medium-lateral parameters does not allow to use them. Apart from the bipodal phase no differences were found between the two walking conditions. Key words: biomechanics, footwear, variability.

  17. Effects of simulated genu valgum and genu varum on ground reaction forces and subtalar joint function during gait.

    Science.gov (United States)

    Van Gheluwe, Bart; Kirby, Kevin A; Hagman, Friso

    2005-01-01

    The mechanical effects of genu valgum and varum deformities on the subtalar joint were investigated. First, a theoretical model of the forces within the foot and lower extremity during relaxed bipedal stance was developed predicting the rotational effect on the subtalar joint due to genu valgum and varum deformities. Second, a kinetic gait study was performed involving 15 subjects who walked with simulated genu valgum and genu varum over a force plate and a plantar pressure mat to determine the changes in the ground reaction force vector within the frontal plane and the changes in the center-of-pressure location on the plantar foot. These results predicted that a genu varum deformity would tend to cause a subtalar pronation moment to increase or a supination moment to decrease during the contact and propulsion phases of walking. With genu valgum, it was determined that during the contact phase a subtalar pronation moment would increase, whereas in the early propulsive phase, a subtalar supination moment would increase or a pronation moment would decrease. However, the current inability to track the spatial position of the subtalar joint axis makes it difficult to determine the absolute direction and magnitudes of the subtalar joint moments.

  18. Time-series ground-water-level and aquifer-system compaction data, Edwards Air Force Base, Antelope Valley, California, January 1991 through September 1993

    Science.gov (United States)

    Freeman, L.A.

    1996-01-01

    As part of a study by the U.S. Geological Survey, a monitoring program was implemented to collect time-series ground-water-level and aquifer-system compaction data at Edwards Air Force Base, California. The data presented in this report were collected from 18 piezometers, 3 extensometers, 1 barometer, and 1 rain gage from January 1991 through September 1993. The piezometers and extensometers are at eight sites in the study area. This report discusses the ground-water-level and aquifer-system compaction monitoring networks, and presents the recorded data in graphs. The data reported are available in the data base of the U.S. Geological Survey.

  19. The decay characteristic of $^{22}$Si and its ground-state mass significantly affected by three-nucleon forces

    CERN Document Server

    Xu, X X; Sun, L J; Wang, J S; Lam, Y H; Lee, J; Fang, D Q; Li, Z H; Smirnova, N A; Yuan, C X; Yang, L; Wang, Y T; Li, J; Ma, N R; Wang, K; Zang, H L; Wang, H W; Li, C; Liu, M L; Wang, J G; Shi, C Z; Nie, M W; Li, X F; Li, H; Ma, J B; Ma, P; Jin, S L; Huang, M R; Bai, Z; Yang, F; Jia, H M; Liu, Z H; Wang, D X; Yang, Y Y; Zhou, Y J; Ma, W H; Chen, J; Hu, Z G; Zhang, Y H; Ma, X W; Zhou, X H; Ma, Y G; Xu, H S; Xiao, G Q; Zhang, H Q

    2016-01-01

    The decay of the proton-rich nucleus $^{22}$Si was studied by a silicon array coupled with germanium clover detectors. Nine charged-particle groups are observed and most of them are recognized as $\\beta$-delayed proton emission. A charged-particle group at 5600 keV is identified experimentally as $\\beta$-delayed two-proton emission from the isobaric analog state of $^{22}$Al. Another charged-particle emission without any $\\beta$ particle at the low energy less than 300 keV is observed. The half-life of $^{22}$Si is determined as 27.5 (18) ms. The experimental results of $\\beta$-decay of $^{22}$Si are compared and in nice agreement with shell-model calculations. The mass excess of the ground state of $^{22}$Si deduced from the experimental data shows that three-nucleon (3N) forces with repulsive contributions have significant effects on nuclei near the proton drip line.

  20. Vessel grounding in entrance channels: case studies and physical model tests

    CSIR Research Space (South Africa)

    Tulsi, K

    2014-05-01

    Full Text Available Physical model studies were conducted of a 250K DWT fully laden iron ore vessel grounding on the side slopes of the outbound channel at a major Australian port. A key deliverable of the study was to estimate the tug force required to pull the vessel...

  1. The ground state of medium-heavy nuclei with non central forces

    CERN Document Server

    Fabrocini, A

    1997-01-01

    We study microscopically the ground state properties of 16O and 40Ca nuclei within correlated basis function theory. A truncated version of the realistic Urbana v14 (U14) potential, without momentum dependent terms, is adopted with state dependent correlations having spin, isospin and tensor components. Fermi hypernetted chain integral equations and single operator chain approximation are used to evaluate one- and two-body densities and ground state energy. The results are in good agreement with the available variational MonteCarlo data, providing a first substantial check for the accuracy of the cluster expansion method with state dependent correlations. The finite nuclei treatment of non central interactions and correlations has, at least, the same level of accuracy as in infinite nuclear matter. The binding energy for the full U14+TNI interaction is computed, addressing its small momentum dependent contributions in local density approximation. The nuclei are underbound by about 1 MeV per nucleon. Further e...

  2. Withdrawal reflexes examined during human gait by ground reaction forces: site and gait phase dependency.

    Science.gov (United States)

    Emborg, Jonas; Spaich, Erika G; Andersen, Ole K

    2009-01-01

    The objective of this study was to investigate the modulation of the nociceptive withdrawal reflex during gait measured using Force Sensitive Resistors (FSR). Electrical stimulation was delivered to four locations on the sole of the foot at three different time points between heel-off and toe-off. Peak force changes were measured by FSRs attached to the big toe, distal to the first and fourth metatarsophalangeal joints, and the medial process of the calcaneus on both feet. Force changes were assessed in five gait sub-phases. The painful stimulation led to increased ipsilateral unloading (10 +/- 1 N) and contralateral loading (12 +/- 1 N), which were dependent on stimulation site and phase. In contrast, the hallux of the ipsilateral foot plantar flexed, thus facilitating the push-off. The highest degree of plantar flexion (23 +/- 10 N; range, 8-44 N) was seen in the second double support phase following the stimulation. Site and phase modulation of the reflex were detected in the force signals from all selected anatomical landmarks. In the kinematic responses, both site and phase modulation were observed. For stimulations near toe-off, withdrawal was primarily accomplished by ankle dorsiflexion, while the strategy for stimulations at heel-off was flexion of the knee and hip joints.

  3. Step-to-step spatiotemporal variables and ground reaction forces of intra-individual fastest sprinting in a single session.

    Science.gov (United States)

    Nagahara, Ryu; Mizutani, Mirai; Matsuo, Akifumi; Kanehisa, Hiroaki; Fukunaga, Tetsuo

    2017-10-07

    We aimed to investigate the step-to-step spatiotemporal variables and ground reaction forces during the acceleration phase for characterising intra-individual fastest sprinting within a single session. Step-to-step spatiotemporal variables and ground reaction forces produced by 15 male athletes were measured over a 50-m distance during repeated (three to five) 60-m sprints using a long force platform system. Differences in measured variables between the fastest and slowest trials were examined at each step until the 22nd step using a magnitude-based inferences approach. There were possibly-most likely higher running speed and step frequency (2nd to 22nd steps) and shorter support time (all steps) in the fastest trial than in the slowest trial. Moreover, for the fastest trial there were likely-very likely greater mean propulsive force during the initial four steps and possibly-very likely larger mean net anterior-posterior force until the 17th step. The current results demonstrate that better sprinting performance within a single session is probably achieved by 1) a high step frequency (except the initial step) with short support time at all steps, 2) exerting a greater mean propulsive force during initial acceleration, and 3) producing a greater mean net anterior-posterior force during initial and middle acceleration.

  4. A New Proxy Measurement Algorithm with Application to the Estimation of Vertical Ground Reaction Forces Using Wearable Sensors

    Directory of Open Access Journals (Sweden)

    Yuzhu Guo

    2017-09-01

    Full Text Available Measurement of the ground reaction forces (GRF during walking is typically limited to laboratory settings, and only short observations using wearable pressure insoles have been reported so far. In this study, a new proxy measurement method is proposed to estimate the vertical component of the GRF (vGRF from wearable accelerometer signals. The accelerations are used as the proxy variable. An orthogonal forward regression algorithm (OFR is employed to identify the dynamic relationships between the proxy variables and the measured vGRF using pressure-sensing insoles. The obtained model, which represents the connection between the proxy variable and the vGRF, is then used to predict the latter. The results have been validated using pressure insoles data collected from nine healthy individuals under two outdoor walking tasks in non-laboratory settings. The results show that the vGRFs can be reconstructed with high accuracy (with an average prediction error of less than 5.0% using only one wearable sensor mounted at the waist (L5, fifth lumbar vertebra. Proxy measures with different sensor positions are also discussed. Results show that the waist acceleration-based proxy measurement is more stable with less inter-task and inter-subject variability than the proxy measures based on forehead level accelerations. The proposed proxy measure provides a promising low-cost method for monitoring ground reaction forces in real-life settings and introduces a novel generic approach for replacing the direct determination of difficult to measure variables in many applications.

  5. Peak Vertical Ground Reaction Force during Two-Leg Landing: A Systematic Review and Mathematical Modeling

    Directory of Open Access Journals (Sweden)

    Wenxin Niu

    2014-01-01

    Full Text Available Objectives. (1 To systematically review peak vertical ground reaction force (PvGRF during two-leg drop landing from specific drop height (DH, (2 to construct a mathematical model describing correlations between PvGRF and DH, and (3 to analyze the effects of some factors on the pooled PvGRF regardless of DH. Methods. A computerized bibliographical search was conducted to extract PvGRF data on a single foot when participants landed with both feet from various DHs. An innovative mathematical model was constructed to analyze effects of gender, landing type, shoes, ankle stabilizers, surface stiffness and sample frequency on PvGRF based on the pooled data. Results. Pooled PvGRF and DH data of 26 articles showed that the square root function fits their relationship well. An experimental validation was also done on the regression equation for the medicum frequency. The PvGRF was not significantly affected by surface stiffness, but was significantly higher in men than women, the platform than suspended landing, the barefoot than shod condition, and ankle stabilizer than control condition, and higher than lower frequencies. Conclusions. The PvGRF and root DH showed a linear relationship. The mathematical modeling method with systematic review is helpful to analyze the influence factors during landing movement without considering DH.

  6. Ground reaction force analysed with correlation coefficient matrix in group of stroke patients.

    Science.gov (United States)

    Szczerbik, Ewa; Krawczyk, Maciej; Syczewska, Małgorzata

    2014-01-01

    Stroke is the third cause of death in contemporary society and causes many disorders. Clinical scales, ground reaction force (GRF) and objective gait analysis are used for assessment of patient's rehabilitation progress during treatment. The goal of this paper is to assess whether signal correlation coefficient matrix applied to GRF can be used for evaluation of the status of post-stroke patients. A group of patients underwent clinical assessment and instrumented gait analysis simultaneously three times. The difference between components of patient's GRF (vertical, fore/aft, med/lat) and normal ones (reference GRF of healthy subjects) was calculated as correlation coefficient. Patients were divided into two groups ("worse" and "better") based on the clinical functional scale tests done at the beginning of rehabilitation process. The results obtained by these two groups were compared using statistical analysis. An increase of median value of correlation coefficient is observed in all components of GRF, but only in non-paretic leg. Analysis of GRF signal can be helpful in assessment of post-stroke patients during rehabilitation. Improvement in stroke patients was observed in non-paretic leg of the "worse" group. GRF analysis should not be the only tool for objective validation of patient's improvement, but could be used as additional source of information.

  7. Ground reaction forces and osteogenic index of the sport of cyclocross.

    Science.gov (United States)

    Tolly, Brian; Chumanov, Elizabeth; Brooks, Alison

    2014-01-01

    Weight-bearing activity has been shown to increase bone mineral density. Our purpose was to measure vertical ground reaction forces (GRFs) during cyclocross-specific activities and compute their osteogenic index (OI). Twenty-five healthy cyclocross athletes participated. GRF was measured using pressure-sensitive insoles during seated and standing cycling and four cyclocross-specific activities: barrier flat, barrier uphill, uphill run-up, downhill run-up. Peak and mean GRF values, according to bodyweight, were determined for each activity. OI was computed using peak GRF and number of loading cycles. GRF and OI were compared across activities using repeated-measures ANOVA. Number of loading cycles per activity was 6(1) for barrier flat, 8(1) barrier uphill, 7(1) uphill run-up, 12(3) downhill run-up. All activities had significantly (P < 0.01) higher peak GRF, mean GRF values and OI when compared to both seated and standing cycling. The barrier flat condition (P < 0.01) had highest peak (2.9 times bodyweight) and mean GRF values (2.3 times bodyweight). Downhill run-up (P < 0.01) had the highest OI (6.5). GRF generated during the barrier flat activity is similar in magnitude to reported GRFs during running and hopping. Because cyclocross involves weight bearing components, it may be more beneficial to bone health than seated road cycling.

  8. Surface forces studied with colloidal probe atomic force microscopy

    NARCIS (Netherlands)

    Giesbers, M.

    2001-01-01

    Forces between surfaces are a determining factor for the performance of natural as well as synthetic colloidal systems, and play a crucial role in industrial production processes. Measuring these forces is a scientific and experimental challenge and over the years several techniques have been develo

  9. Surface forces studied with colloidal probe atomic force microscopy

    NARCIS (Netherlands)

    Giesbers, M.

    2001-01-01

    Forces between surfaces are a determining factor for the performance of natural as well as synthetic colloidal systems, and play a crucial role in industrial production processes. Measuring these forces is a scientific and experimental challenge and over the years several techniques have

  10. Adaptive locomotor training on an end-effector gait robot: evaluation of the ground reaction forces in different training conditions.

    Science.gov (United States)

    Tomelleri, Christopher; Waldner, Andreas; Werner, Cordula; Hesse, Stefan

    2011-01-01

    The main goal of robotic gait rehabilitation is the restoration of independent gait. To achieve this goal different and specific patterns have to be practiced intensively in order to stimulate the learning process of the central nervous system. The gait robot G-EO Systems was designed to allow the repetitive practice of floor walking, stair climbing and stair descending. A novel control strategy allows training in adaptive mode. The force interactions between the foot and the ground were analyzed on 8 healthy volunteers in three different conditions: real floor walking on a treadmill, floor walking on the gait robot in passive mode, floor walking on the gait robot in adaptive mode. The ground reaction forces were measured by a Computer Dyno Graphy (CDG) analysis system. The results show different intensities of the ground reaction force across all of the three conditions. The intensities of force interactions during the adaptive training mode are comparable to the real walking on the treadmill. Slight deviations still occur in regard to the timing pattern of the forces. The adaptive control strategy comes closer to the physiological swing phase than the passive mode and seems to be a promising option for the treatment of gait disorders. Clinical trials will validate the efficacy of this new option in locomotor therapy on the patients.

  11. Geodetic Study of Ground Instability at Active Geothermal Reservoirs

    Science.gov (United States)

    Aly, M. H.; Bawner, E.; Nanis, H.; Alotaibi, M.; Suwihli, S.

    2016-12-01

    Active geothermal systems may cause substantial crustal deformation that can damage the precious infrastructure and increase the frequency and magnitude of earthquakes in the surrounding region. Geothermal production practices commonly contribute to surface motions triggered by natural tectonic and volcanic forces at active geothermal fields and may intensify their significance over years. Hence, routine monitoring of active geothermal sites is required to evaluate the impact of production activities and assess associated ground instabilities. Knowledge of the reservoir geometry, compaction, and response to production behaviors will aid in identifying ideal locations for new production and recharge wells to advance the performance of such a reservoir. This study investigates active geothermal processes and recent seismic events and their impacts on crustal deformation at the Raft River Geothermal Power Plant (RGP) in southeastern Idaho and at the Coso Geothermal (CG) field in eastern California. Contemporary geodetic observations from Synthetic Aperture Radar Interferometry (InSAR) and Global Positioning System (GPS) imply a rapid rate of ground subsidence ( 7 cm/yr) across the Raft River Valley with a local anomaly of ample uplift (3 cm/yr) near RGP. The measured rate of deflation at CG is 3.1 cm/yr throughout a large area ( 55 sq km) that is directly correlating with the extent of active geothermal production. These rapid rates of ground deformation indicate considerable depressurization of the two reservoirs. Volumetric analysis and modeling are currently underway to characterize the two reservoirs and to infer their deformation source parameters. Understanding the hydrothermal-geomechanical response of the reservoirs to fluid production and injection is crucial for their management and development.

  12. Computerized identification and classification of stance phases as made by front or hind feet of walking cows based on 3-dimensional ground reaction forces

    DEFF Research Database (Denmark)

    Skjøth, Flemming; Thorup, V. M.; do Nascimento, Omar Feix

    2013-01-01

    Lameness is a frequent disorder in dairy cows and in large dairy herds manual lameness detection is a time-consuming task. This study describes a method for automatic identification of stance phases in walking cows, and their classification as made by a front or a hind foot based on ground reaction...... force information. Features were derived from measurements made using two parallel 3-dimensional force plates. The approach presented is based on clustering of Centre of Pressure (COP) trace points over space and time, combined with logical sequencing of stance phases based on the dynamics...

  13. Air Force Studies Board Block 00 Studies

    Science.gov (United States)

    2016-07-14

    maintenance UESC Utility Energy Service Contract USAF U.S. Air Force WAGES water, air, gas, electricity, steam DISTRIBUTION A: Distribution approved for...dashboard display system for tracking water, air, gas, electricity, and steam ( WAGES ) consumption on a monthly basis and comparing it to budget targets...Install Hanging Door Seals in High Traffic Areas Use Ceiling Fans to Eliminate Stratification of Air in High Ceiling Areas Install Adequate Building

  14. Dimensional analysis and ground reaction forces for stair climbing: effects of age and task difficulty.

    Science.gov (United States)

    Bertucco, Matteo; Cesari, Paola

    2009-02-01

    Altered perception-action capability is often associated with falls and diminished self-efficacy in older people. This study evaluated and compared perception-action capability in stair-climbing performance of 18 healthy volunteers assigned to two age groups (mean age, 26.3+/-4.3 years and 66.4+/-4.7 years, respectively). The experimental set-up included 14 stairs (50 cm wide, 60 cm deep, riser height 35-90 cm) positioned at the edge of a force platform. The task was to climb the stair with the greatest riser height subjects thought they could climb without outside support or use of hands. Dimensional and dynamic data were collected and analyzed to reveal the invariant relationships that sustain action preparation and execution. All subjects chose the same proportion between stair height and distance covered before mounting the stair, as expressed by the invariant angle (alpha). While the geometric invariant relationship was picked up as a visual guide prior to action, there was a dynamic invariance in the forces applied during actual execution. To establish whether the invariance still held in extreme cases, two perturbed conditions were introduced in which stair distances were changed, forcing subjects to execute a foot-strike, either very far from or near to the stair, before climbing it, so as to reveal any significant adaptations the climber would undertake to avoid slips or falls. Older and younger subjects applied appropriate visual and motor guidance by scaling their motor capabilities to the environmental dimensions.

  15. Assessment of Clear Sky Radiative Forcing in the Caribbean Region Using an Aerosol Dispersion Model and Ground Radiometry During Puerto Rico Dust Experiment

    Science.gov (United States)

    Gasso, Santiago; Qi, Qiang; Westpthal, Douglas; Reid, Jeffery; Tsay, Si-Chee

    2004-01-01

    This study investigates the surface and top of the atmosphere solar radiative forcing by long-range transport of Saharan dust. The calculations of radiative forcing are based on measurements collected in the Puerto Rico Dust Experiment (PRIDE) carried out during July, 2000. The purpose of the experiment was the characterization of the Saharan dust plume, which frequently reaches the Caribbean region during the summer. The experiment involved the use of three approaches to study the plume: space and ground based remote sensing, airborne and ground based in-situ measurements and aerosol dispersion modeling. The diversity of measuring platforms provides an excellent opportunity for determination of the direct effect of dust on the clear sky radiative forcing. Specifically, comparisons of heating rates, surface and TOA fluxes derived from the Navy global aerosol dispersion model NAAPS (NRL Aerosol Analysis and Prediction System) and actual measurements of fluxes from ground and space based platforms are shown. In addition, the direct effect of dust on the clear sky radiative forcing is modeled. The extent and time of evolution of the radiative properties of the plume are computed with the aerosol concentrations modeled by NAAPS. Standard aerosol parameterizations, as well as in-situ composition and size distributions measured during PRIDE, are utilized to compute the aerosol optical depth, single scattering albedo and asymmetry factor. Radiative transfer computations are done with an in-house modified spectral radiative transfer code (Fu-Liou). The code includes gas absorption and cloud particles (ice and liquid phase) and it allows the input of meteorological data. The code was modified to include modules for the aerosols contribution to the calculated fluxes. This comparison study helps to narrow the current uncertainty in the dust direct radiative forcing, as recently reported in the 2001 IPCC assessment.

  16. Association of sprint performance with ground reaction forces during acceleration and maximal speed phases in a single sprint.

    Science.gov (United States)

    Nagahara, Ryu; Mizutani, Mirai; Matsuo, Akifumi; Kanehisa, Hiroaki; Fukunaga, Tetsuo

    2017-09-27

    We aimed to clarify the mechanical determinants of sprinting performance during acceleration and maximal speed phases of a single sprint, using ground reaction forces (GRFs). While 18 male athletes performed a 60-m sprint, GRF was measured at every step over a 50-m distance from the start. Variables during the entire acceleration phase were approximated with a fourth-order polynomial. Subsequently, accelerations at 55%, 65%, 75%, 85%, and 95% of maximal speed, and running speed during the maximal speed phase were determined as sprinting performance variables. Ground reaction impulses and mean GRFs during the acceleration and maximal speed phases were selected as independent variables. Stepwise multiple regression analysis selected propulsive and braking impulses as contributors to acceleration at 55%-95% (β > 0.724) and 75%-95% (β > 0.176), respectively, of maximal speed. Moreover, mean vertical force was a contributor to maximal running speed (β = 0.481). The current results demonstrate that exerting a large propulsive force during the entire acceleration phase, suppressing braking force when approaching maximal speed, and producing a large vertical force during the maximal speed phase are essential for achieving greater acceleration and maintaining higher maximal speed, respectively.

  17. Force Limiting Vibration Tests Evaluated from both Ground Acoustic Tests and FEM Simulations of a Flight Like Vehicle System Assembly

    Science.gov (United States)

    Smith, Andrew; LaVerde, Bruce; Waldon, James; Hunt, Ron

    2014-01-01

    Marshall Space Flight Center has conducted a series of ground acoustic tests with the dual goals of informing analytical judgment, and validating analytical methods when estimating vibroacoustic responses of launch vehicle subsystems. The process of repeatedly correlating finite element-simulated responses with test-measured responses has assisted in the development of best practices for modeling and post-processing. In recent work, force transducers were integrated to measure interface forces at the base of avionics box equipment. Other force data was indirectly measured using strain gauges. The combination of these direct and indirect force measurements has been used to support and illustrate the advantages of implementing the Force Limiting approach for equipment qualification tests. The comparison of force response from integrated system level tests to measurements at the same locations during component level vibration tests provides an excellent illustration. A second comparison of the measured response cases from the system level acoustic tests to finite element simulations has also produced some principles for assessing the suitability of Finite Element Models (FEMs) for making vibroacoustics estimates. The results indicate that when FEM models are employed to guide force limiting choices, they should include sufficient detail to represent the apparent mass of the system in the frequency range of interest.

  18. Preparing to be unprepared: ground force commander decision making in a volatile, uncertain, complex, and ambiguous world

    OpenAIRE

    Karaoguz, Adam A.

    2016-01-01

    Approved for public release; distribution is unlimited What are the characteristics of effective ground force commander (GFC) decision making? What commonalities do we see? What are best practices for pre-mission preparation and mission execution? This thesis focuses on GFC decision making in order to investigate how to better prepare leaders for the current operating environment. It examines tactical-level decision making under conditions of uncertainty. It does so by drawing on interview...

  19. Extraction of primitive representation from captured human movements and measured ground reaction force to generate physically consistent imitated behaviors.

    Science.gov (United States)

    Ariki, Yuka; Hyon, Sang-Ho; Morimoto, Jun

    2013-04-01

    In this paper, we propose an imitation learning framework to generate physically consistent behaviors by estimating the ground reaction force from captured human behaviors. In the proposed framework, we first extract behavioral primitives, which are represented by linear dynamical models, from captured human movements and measured ground reaction force by using the Gaussian mixture of linear dynamical models. Therefore, our method has small dependence on classification criteria defined by an experimenter. By switching primitives with different combinations while estimating the ground reaction force, different physically consistent behaviors can be generated. We apply the proposed method to a four-link robot model to generate squat motion sequences. The four-link robot model successfully generated the squat movements by using our imitation learning framework. To show generalization performance, we also apply the proposed method to robot models that have different torso weights and lengths from a human demonstrator and evaluate the control performances. In addition, we show that the robot model is able to recognize and imitate demonstrator movements even when the observed movements are deviated from the movements that are used to construct the primitives. For further evaluation in higher-dimensional state space, we apply the proposed method to a seven-link robot model. The seven-link robot model was able to generate squat-and-sway motions by using the proposed framework.

  20. Vertical ground reaction force-based analysis of powered exoskeleton-assisted walking in persons with motor-complete paraplegia.

    Science.gov (United States)

    Fineberg, Drew B; Asselin, Pierre; Harel, Noam Y; Agranova-Breyter, Irina; Kornfeld, Stephen D; Bauman, William A; Spungen, Ann M

    2013-07-01

    To use vertical ground reaction force (vGRF) to show the magnitude and pattern of mechanical loading in persons with spinal cord injury (SCI) during powered exoskeleton-assisted walking. A cross-sectional study was performed to analyze vGRF during powered exoskeleton-assisted walking (ReWalk™: Argo Medical Technologies, Inc, Marlborough, MA, USA) compared with vGRF of able-bodied gait. Veterans Affairs Medical Center. Six persons with thoracic motor-complete SCI (T1-T11 AIS A/B) and three age-, height-, weight- and gender-matched able-bodied volunteers participated. SCI participants were trained to ambulate over ground using a ReWalk™. vGRF was recorded using the F-Scan™ system (TekScan, Boston, MA, USA). Peak stance average (PSA) was computed from vGRF and normalized across all participants by percent body weight. Peak vGRF was determined for heel strike, mid-stance, and toe-off. Relative linear impulse and harmonic analysis provided quantitative support for analysis of powered exoskeletal gait. Participants with motor-complete SCI, ambulating independently with a ReWalk™, demonstrated mechanical loading magnitudes and patterns similar to able-bodied gait. Harmonic analysis of PSA profile by Fourier transform contrasted frequency of stance phase gait components between able-bodied and powered exoskeleton-assisted walking. Powered exoskeleton-assisted walking in persons with motor-complete SCI generated vGRF similar in magnitude and pattern to that of able-bodied walking. This suggests the potential for powered exoskeleton-assisted walking to provide a mechanism for mechanical loading to the lower extremities. vGRF profile can be used to examine both magnitude of loading and gait mechanics of powered exoskeleton-assisted walking among participants of different weight, gait speed, and level of assist.

  1. Gait Phases Recognition from Accelerations and Ground Reaction Forces: Application of Neural Networks

    Directory of Open Access Journals (Sweden)

    S. Rafajlović

    2009-06-01

    Full Text Available The goal of this study was to test the applicability of accelerometer as the sensor for assessment of the walking. We present here the comparison of gait phases detected from the data recorded by force sensing resistors mounted in the shoe insoles, non-processed acceleration and processed acceleration perpendicular to the direction of the foot. The gait phases in all three cases were detected by means of a neural network. The output from the neural network was the gait phase, while the inputs were data from the sensors. The results show that the errors were in the ranges: 30 ms (2.7% – force sensors; 150 ms (13.6% – nonprocessed acceleration, and 120 ms (11% – processed acceleration data. This result suggests that it is possible to use the accelerometer as the gait phase detector, however, with the knowledge that the gait phases are time shifted for about 100 ms with respect the neural network predicted times.

  2. Effect of Five-Finger Shoes on Vertical Ground Reaction Force Loading Rates and Perceived Comfort during the Stance Phase of the Running

    Directory of Open Access Journals (Sweden)

    Seyede Zeynab Hoseini

    2016-06-01

    Full Text Available Objective:  Increased vertical ground reaction force loading rates and lack of comfort footwear in the early stance phase can increase the risk of overuse injuries. The purpose of this study was to investigate the effect of Five-finger shoes on vertical ground reaction force loading rate and perceived comfort during the stance phase of running. Methods: 15 male students (aged 24 ± 5/24 years, weight 75/8 ± 4/61 kg, height 178/6 ± 6/64 cm were selected. Subjects were asked to run over a force plate, in control shoe, five finger shoe and barefoot conditions. Loading rate using the slope of the vertical reaction force and perceived comfort were determined using a visual analogue scale. One factor repeated measures ANOVA was used to test the loading rate hypothesis and Paired t-tests was used to test the meaningfulness of perceived comfort (P<0/05. Results: The effect of shoes on loading rate was found to be not significant (P=0.1. However, comfort of control shoes increased by 10. 92% as compared to that of five-finger shoes (P=0.001.  Conclusion: The loading rate of five-finger shoes is the same as that of barefoot during running; however, as subjects did not perceive them as comfortable as regular shoes are five-finger shoes cannot be advised as a desirable choice in exercises.

  3. Large General Purpose Frame for Studying Force Vectors

    Science.gov (United States)

    Heid, Christy; Rampolla, Donald

    2011-01-01

    Many illustrations and problems on the vector nature of forces have weights and forces in a vertical plane. One of the common devices for studying the vector nature of forces is a horizontal "force table," in which forces are produced by weights hanging vertically and transmitted to cords in a horizontal plane. Because some students have…

  4. Multi-body simulation of a canine hind limb: model development, experimental validation and calculation of ground reaction forces

    Directory of Open Access Journals (Sweden)

    Wefstaedt Patrick

    2009-11-01

    Full Text Available Abstract Background Among other causes the long-term result of hip prostheses in dogs is determined by aseptic loosening. A prevention of prosthesis complications can be achieved by an optimization of the tribological system which finally results in improved implant duration. In this context a computerized model for the calculation of hip joint loadings during different motions would be of benefit. In a first step in the development of such an inverse dynamic multi-body simulation (MBS- model we here present the setup of a canine hind limb model applicable for the calculation of ground reaction forces. Methods The anatomical geometries of the MBS-model have been established using computer tomography- (CT- and magnetic resonance imaging- (MRI- data. The CT-data were collected from the pelvis, femora, tibiae and pads of a mixed-breed adult dog. Geometric information about 22 muscles of the pelvic extremity of 4 mixed-breed adult dogs was determined using MRI. Kinematic and kinetic data obtained by motion analysis of a clinically healthy dog during a gait cycle (1 m/s on an instrumented treadmill were used to drive the model in the multi-body simulation. Results and Discussion As a result the vertical ground reaction forces (z-direction calculated by the MBS-system show a maximum deviation of 1.75%BW for the left and 4.65%BW for the right hind limb from the treadmill measurements. The calculated peak ground reaction forces in z- and y-direction were found to be comparable to the treadmill measurements, whereas the curve characteristics of the forces in y-direction were not in complete alignment. Conclusion In conclusion, it could be demonstrated that the developed MBS-model is suitable for simulating ground reaction forces of dogs during walking. In forthcoming investigations the model will be developed further for the calculation of forces and moments acting on the hip joint during different movements, which can be of help in context with the in

  5. Refugee and Forced Migration Studies Online

    DEFF Research Database (Denmark)

    Andersson, Vibeke

    the research, instruction, whether tradition, hybrid or online, and policy practice in the field of refugee and forced migration studies. The Roundtable will feature the principal collaborators of the ORTT & PF who will outline how they have utilize this new open source website in their research and courses...... developments in communications technologies and the Internet and the proliferation of websites such as the CARFMS – Online Research and Teaching Tool and Practitioners Forum (ORTT & PF) and the Refugee Research Network (RRN), as examples, have contributed to the accessibility of information, knowledge...... and the convergence of expertise amongst practitioners has transformed the nature of both research, teaching and policy-making in the field of refugee and forced migration studies. The amassing of concentrations of detailed information sources on the Internet or “the cloud” has created new modes and methods...

  6. Results of soil, ground-water, surface-water, and streambed-sediment sampling at Air Force Plane 85, Columbus, Ohio, 1996

    Science.gov (United States)

    Parnell, J.M.

    1997-01-01

    The U.S. Geological Survey (USGS), in cooperation with Aeronautical Systems Center, Environmental Management Directorate, Restoration Division, prepared the Surface- and Ground- Water Monitoring Work Plan for Air Force Plant 85 (AFP 85 or Plant), Columbus, Ohio, under the Air Force Installation Restoration Program to characterize any ground-water, surface-water, and soil contamination that may exist at AFP 85. The USGS began the study in November 1996. The Plant was divided into nine sampling areas, which included some previously investi gated study sites. The investigation activities included the collection and presentation of data taken during drilling and water-quality sampling. Data collection focused on the saturated and unsatur ated zones and surface water. Twenty-three soil borings were completed. Ten monitoring wells (six existing wells and four newly constructed monitoring wells) were selected for water-quality sam pling. Surface-water and streambed-sediment sampling locations were chosen to monitor flow onto and off of the Plant. Seven sites were sampled for both surface-water and streambed-sediment quality. This report presents data on the selected inorganic and organic constituents in soil, ground water, surface water, and streambed sediments at AFP 85. The methods of data collection and anal ysis also are included. Knowledge of the geologic and hydrologic setting could aid Aeronautical Systems Center, Environmental Management Directorate, Restoration Division, and its governing regulatory agencies in future remediation studies.

  7. A Wearable Ground Reaction Force Sensor System and Its Application to the Measurement of Extrinsic Gait Variability

    Science.gov (United States)

    Liu, Tao; Inoue, Yoshio; Shibata, Kyoko

    2010-01-01

    Wearable sensors for gait analysis are attracting wide interest. In this paper, a wearable ground reaction force (GRF) sensor system and its application to measure extrinsic gait variability are presented. To validate the GRF and centre of pressure (CoP) measurements of the sensor system and examine the effectiveness of the proposed method for gait analysis, we conducted an experimental study on seven volunteer subjects. Based on the assessment of the influence of the sensor system on natural gait, we found that no significant differences were found for almost all measured gait parameters (p-values < 0.05). As for measurement accuracy, the root mean square (RMS) differences for the two transverse components and the vertical component of the GRF were 7.2% ± 0.8% and 9.0% ± 1% of the maximum of each transverse component and 1.5% ± 0.9% of the maximum vertical component of GRF, respectively. The RMS distance between both CoP measurements was 1.4% ± 0.2% of the length of the shoe. The area of CoP distribution on the foot-plate and the average coefficient of variation of the triaxial GRF, are the introduced parameters for analysing extrinsic gait variability. Based on a statistical analysis of the results of the tests with subjects wearing the sensor system, we found that the proposed parameters changed according to walking speed and turning (p-values < 0.05). PMID:22163468

  8. A Wearable Ground Reaction Force Sensor System and Its Application to the Measurement of Extrinsic Gait Variability

    Directory of Open Access Journals (Sweden)

    Kyoko Shibata

    2010-11-01

    Full Text Available Wearable sensors for gait analysis are attracting wide interest. In this paper, a wearable ground reaction force (GRF sensor system and its application to measure extrinsic gait variability are presented. To validate the GRF and centre of pressure (CoP measurements of the sensor system and examine the effectiveness of the proposed method for gait analysis, we conducted an experimental study on seven volunteer subjects. Based on the assessment of the influence of the sensor system on natural gait, we found that no significant differences were found for almost all measured gait parameters (p-values < 0.05. As for measurement accuracy, the root mean square (RMS differences for the two transverse components and the vertical component of the GRF were 7.2% ± 0.8% and 9.0% ± 1% of the maximum of each transverse component and 1.5% ± 0.9% of the maximum vertical component of GRF, respectively. The RMS distance between both CoP measurements was 1.4% ± 0.2% of the length of the shoe. The area of CoP distribution on the foot-plate and the average coefficient of variation of the triaxial GRF, are the introduced parameters for analysing extrinsic gait variability. Based on a statistical analysis of the results of the tests with subjects wearing the sensor system, we found that the proposed parameters changed according to walking speed and turning (p-values < 0.05.

  9. The preparatory state of ground reaction forces in defending against a dribbler in a basketball 1-on-1 dribble subphase.

    Science.gov (United States)

    Fujii, Keisuke; Yoshioka, Shinsuke; Isaka, Tadao; Kouzaki, Motoki

    2015-03-01

    We previously demonstrated the relationship between sidestepping performance and the preparatory state of ground reaction forces (GRFs). The present study investigated the effect of the preparatory state of GRFs on defensive performance in 1-on-1 subphase of basketball. Ten basketball players participated in 1-on-1 dribble game of basketball. The outcomes (penetrating and guarding) and the preparatory state of GRFs (non-weighted and weighted states, i.e. vertical GRFs below and above 120% of body weight, respectively) were assessed by separating the phases. In the non-weighted state and the weighted state to determine the outcome, the probability of successful guarding was 78.8% and 29.6%, respectively. The non-weighted state prevented delay of the defensive step in the determination phase. Both the non-weighted and weighted states, immediately before the determination phase, were likely to change to the weighted state in the determination phase; during this time, the defender's preparatory state would be destabilised, presumably by the dribbler's movement. These results revealed that the preparatory GRFs before the defensive step help to explain the outcome of the 1-on-1 subphase, and suggest a better way to prevent delaying initiation of the defensive step and thereby to guard more effectively against a dribbler.

  10. Resolution of Forces and Strain Measurements from an Acoustic Ground Test

    Science.gov (United States)

    Smith, Andrew M.; LaVerde, Bruce T.; Hunt, Ronald; Waldon, James M.

    2013-01-01

    The Conservatism in Typical Vibration Tests was Demonstrated: Vibration test at component level produced conservative force reactions by approximately a factor of 4 (approx.12 dB) as compared to the integrated acoustic test in 2 out of 3 axes. Reaction Forces Estimated at the Base of Equipment Using a Finite Element Based Method were Validated: FEM based estimate of interface forces may be adequate to guide development of vibration test criteria with less conservatism. Element Forces Estimated in Secondary Structure Struts were Validated: Finite element approach provided best estimate of axial strut forces in frequency range below 200 Hz where a rigid lumped mass assumption for the entire electronics box was valid. Models with enough fidelity to represent diminishing apparent mass of equipment are better suited for estimating force reactions across the frequency range. Forward Work: Demonstrate the reduction in conservatism provided by; Current force limited approach and an FEM guided approach. Validate proposed CMS approach to estimate coupled response from uncoupled system characteristics for vibroacoustics.

  11. Study of borehole probing methods to improve the ground characterization

    Science.gov (United States)

    Naeimipour, Ali

    partially condition of discontinuities. Two of the more promising tools have been tested during this project, which are QL40OBI Optical TV and Slim Borehole Scanner (SBS) manufacture by ALT-Mount Sopris and DMT, respectively. The field experiment with QL40OBI showed that the images generated for downward and sub-horizontal boreholes are of good quality and can be used to evaluate the joint conditions. However, this device is not suitable for use inside the upward drillholes. The Slim Borehole Scanner (SBS) manufactured by DMT in Germany has the required features for borescoping the roofbolt holes. This includes the ease of operation and suitable geometry along with an unwrapped 360-degree picture of the borehole wall. This instrument was concluded to be the best option yet for obtaining images from boreholes with any arbitrary orientation. In addition, a new tool, called Rock Strength Borehole Probe (RSBP), was developed for estimation of the rock strength through scratching the rock surface in the borehole. This device is designed to be a light, flexible, quick, non-disruptive, and cost effective alternative to estimate the rock strength inside the boreholes in underground mines and tunnels. An extensive number of laboratory tests under variable conditions were conducted to develop equations to estimate the Uniaxial Compressive Strength (UCS) and Brazilian Tensile Strength (BTS) of the rock from measured cutting forces. In these experiments, 27 different rock types were tested by full scale scratch tests, including the cutting tests by a miniature disc. The results show a good correlation between the normal force and the compressive strength of sedimentary/metamorphic rock if the depth of scratch is known. No significant correlation was observed for igneous rocks, due to the impacts of grain size. Current studies show promising results for using RSBP. The laboratory and field tests proved the functionality of this tool. This probe is capable of entering boreholes of 45 mm

  12. Study of the aerodynamic forces evaluation methods

    Directory of Open Access Journals (Sweden)

    Stelian GALETUSE

    2011-06-01

    Full Text Available This paper reviews some of the different formulations of the force exerted on a submerged body by the fluid flowing around it. The study is particularly focused on identifying the most appropriate formulations and their inherent assumptions and experimental conditions that fit the current experimental techniques. Several force formulations are derived using different assumptions such as finite and infinite domain, simple and double connected domains. The aim was to obtain formulations that can benefit from the data gathered through the particle image velocimetry method, more explicitly the velocity field around the body and its derivatives. The equations were afterwards discussed in terms of their exposure to error magnification due to the limitations of the experimental method and recommendations were made for appropriate situations in which different formulations should be used. In conclusion, all different force formulations are valid and can be used with the Particle Image Velocimetry data but the accuracy of each outcome depends on the problem definition. As a future objective, experimental work should be performed and test the different equations for different flow conditions, steady, unsteady, quasi-steady, and also for different domain ranges.

  13. Special Operations Forces and Elusive Enemy Ground Targets: Lessons from Vietnam and the Persian Gulf War

    Science.gov (United States)

    2001-01-01

    Enemy Ground Targets team members to fire their weapons as they were lifted from the forest floor . 4 9 Moving through and searching the jungle...MACVSOG headquarters, and as bartenders and waitresses at MACVSOG compounds, where they 61Prados, Blood Road, p. 274. Yearly totals for SHINING BRASS

  14. Repulsion forces of superplasticizers on ground granulated blast furnace slag in alkaline media, from AFM measurements to rheological properties

    Directory of Open Access Journals (Sweden)

    Palacios, M.

    2012-12-01

    Full Text Available The electrostatic and steric repulsion induced by different superplasticizers on ground granulated blast furnace slag in alkaline media have been studied. The superplasticizers were sulfonated naphthalene, sulfonated melamine, vinyl copolymer, and polycarboxylate- based admixtures. With these superplasticizers the slag suspensions had negative zeta potentials, ranging from -3 to -10 mV. For the first time the adsorbed layer thicknesses for superplasticizers on slag using colloidal probe atomic force microscopy has been measured. To model the interparticle force interactions an effective Hamaker constant was computed from dielectric properties measured on a dense slag sample produced by spark plasma sintering. The obtained results conclude that the dispersion mechanism for all the superplasticizers studied in the present work is mainly dominated by the steric repulsion. Results were then used in a yield stress model, YODEL, to predict the yield stress with and without the superplasticizers. Predictions of the yield stress agreed well with experimental results.

    En este trabajo se ha estudiado la repulsión electrostática y estérica inducida por diferentes aditivos superplastificantes en sistemas de escoria de horno alto en medios alcalinos. Se han estudiado aditivos superplastificantes basados en naftaleno, melamina, copolímeros vinílicos y basados en policarboxilato. Estos aditivos inducen en la escoria un potencial zeta negativo, entre -3 y -10 mV. Por primera vez, se ha determinado el grosor de la capa de aditivo adsorbido sobre la escoria mediante microscopía de fuerzas atómicas (AFM. Para modelizar las fuerzas de interacción entre partículas, se ha determinado la constante efectiva de Hamaker de la escoria a partir de las propiedades dieléctricas de una muestra de escoria obtenida mediante sinterización spark plasma sintering. Los resultados obtenidos concluyen que el mecanismo de dispersión de los superplastificantes

  15. The influence of gait cadence on the ground reaction forces and plantar pressures during load carriage of young adults.

    Science.gov (United States)

    Castro, Marcelo P; Figueiredo, Maria Cristina; Abreu, Sofia; Sousa, Helena; Machado, Leandro; Santos, Rubim; Vilas-Boas, João Paulo

    2015-07-01

    Biomechanical gait parameters--ground reaction forces (GRFs) and plantar pressures--during load carriage of young adults were compared at a low gait cadence and a high gait cadence. Differences between load carriage and normal walking during both gait cadences were also assessed. A force plate and an in-shoe plantar pressure system were used to assess 60 adults while they were walking either normally (unloaded condition) or wearing a backpack (loaded condition) at low (70 steps per minute) and high gait cadences (120 steps per minute). GRF and plantar pressure peaks were scaled to body weight (or body weight plus backpack weight). With medium to high effect sizes we found greater anterior-posterior and vertical GRFs and greater plantar pressure peaks in the rearfoot, forefoot and hallux when the participants walked carrying a backpack at high gait cadences compared to walking at low gait cadences. Differences between loaded and unloaded conditions in both gait cadences were also observed.

  16. [Environmental investigation of ground water contamination at Wright-Patterson Air Force Base, Ohio]. Volume 5, Appendix A, Part 1, Field Investigation report

    Energy Technology Data Exchange (ETDEWEB)

    1992-03-01

    This report presents information related to the sampling of ground water at the Wright-Patterson Air Force Base. It is part of an investigation into possible ground water contamination. Information concerns well drilling/construction; x-ray diffraction and sampling; soil boring logs; and chain-of-custody records.

  17. Ground motion input in seismic evaluation studies

    Energy Technology Data Exchange (ETDEWEB)

    Sewell, R.T.; Wu, S.C.

    1996-07-01

    This report documents research pertaining to conservatism and variability in seismic risk estimates. Specifically, it examines whether or not artificial motions produce unrealistic evaluation demands, i.e., demands significantly inconsistent with those expected from real earthquake motions. To study these issues, two types of artificial motions are considered: (a) motions with smooth response spectra, and (b) motions with realistic variations in spectral amplitude across vibration frequency. For both types of artificial motion, time histories are generated to match target spectral shapes. For comparison, empirical motions representative of those that might result from strong earthquakes in the Eastern U.S. are also considered. The study findings suggest that artificial motions resulting from typical simulation approaches (aimed at matching a given target spectrum) are generally adequate and appropriate in representing the peak-response demands that may be induced in linear structures and equipment responding to real earthquake motions. Also, given similar input Fourier energies at high-frequencies, levels of input Fourier energy at low frequencies observed for artificial motions are substantially similar to those levels noted in real earthquake motions. In addition, the study reveals specific problems resulting from the application of Western U.S. type motions for seismic evaluation of Eastern U.S. nuclear power plants.

  18. Evaluation of a size-resolved aerosol model based on satellite and ground observations and its implication on aerosol forcing

    Science.gov (United States)

    Ma, Xiaoyan; Yu, Fangqun

    2016-04-01

    The latest AeroCom phase II experiments have showed a large diversity in the simulations of aerosol concentrations, size distribution, vertical profile, and optical properties among 16 detailed global aerosol microphysics models, which contribute to the large uncertainty in the predicted aerosol radiative forcing and possibly induce the distinct climate change in the future. In the last few years, we have developed and improved a global size-resolved aerosol model (Yu and Luo, 2009; Ma et al., 2012; Yu et al., 2012), GEOS-Chem-APM, which is a prognostic multi-type, multi-component, size-resolved aerosol microphysics model, including state-of-the-art nucleation schemes and condensation of low volatile secondary organic compounds from successive oxidation aging. The model is one of 16 global models for AeroCom phase II and participated in a couple of model inter-comparison experiments. In this study, we employed multi-year aerosol optical depth (AOD) data from 2004 to 2012 taken from ground-based Aerosol Robotic Network (AERONET) measurements and Moderate Resolution Imaging Spectroradiometer (MODIS), Multiangle Imaging SpectroRadiometer (MISR) and Sea-viewing Wide Field-of-view Sensor (SeaWiFS) satellite retrievals to evaluate the performance of the GEOS-Chem-APM in predicting aerosol optical depth, including spatial distribution, reginal variation and seasonal variabilities. Compared to the observations, the modelled AOD is overall good over land, but quite low over ocean possibly due to low sea salt emission in the model and/or higher AOD in satellite retrievals, specifically MODIS and MISR. We chose 72 AERONET sites having at least 36 months data available and representative of high spatial domain to compare with the model and satellite data. Comparisons in various representative regions show that the model overall agrees well in the major anthropogenic emission regions, such as Europe, East Asia and North America. Relative to the observations, the modelled AOD is

  19. Space station operations task force. Panel 2 report: Ground operations and support systems

    Science.gov (United States)

    1987-01-01

    The Ground Operations Concept embodied in this report provides for safe multi-user utilization of the Space Station, eases user integration, and gives users autonomy and flexibility. It provides for meaningful multi-national participation while protecting U.S. interests. The concept also supports continued space operations technology development by maintaining NASA expertise and enabling technology evolution. Given attention here are pre/post flight operations, logistics, sustaining engineering/configuration management, transportation services/rescue, and information systems and communication.

  20. Prediction of ground reaction forces and moments during various activities of daily living

    NARCIS (Netherlands)

    Fluit, R.; Andersen, M.S.; Kolk, S.; Verdonschot, N.J.J.; Koopman, H.F.J.M.

    2014-01-01

    Inverse dynamics based simulations on musculoskeletal models is a commonly used method for the analysis of human movement. Due to inaccuracies in the kinematic and force plate data, and a mismatch between the model and the subject, the equations of motion are violated when solving the inverse dynami

  1. Humanitarian nursing challenges: a grounded theory study.

    Science.gov (United States)

    Almonte, Angelica L C

    2009-05-01

    In response to the 2004 tsunami disaster in the Indian Ocean, the U.S. Navy deployed teams aboard the USNS Mercy to provide aid during Operation Unified Assistance (OUA). To date, few research studies have examined how Navy nurses prepared for and clinically performed during this relief operation. The current article describes the challenges faced by Navy nurses throughout OUA. A purposive convenience sample was recruited; 11 participated. Data were collected from interviews, observations, field notes, memos, and a demographic tool. Information was categorized, coded, compared to incoming data, then analyzed using Strauss and Corbin's open coding, axial coding, and selective coding methods. A theoretical model was developed to illustrate how participants experienced the mission. Key lessons learned were that most were unprepared for providing pediatric care, and saying "No" in delivering care. Recommendations include: deployment of advanced-practice nurses (specialists in pediatrics and well-mental health) and predeployment training on moral distress.

  2. Force

    CERN Document Server

    Graybill, George

    2007-01-01

    Forces are at work all around us. Discover what a force is, and different kinds of forces that work on contact and at a distance. We use simple language and vocabulary to make this invisible world easy for students to ""see"" and understand. Examine how forces ""add up"" to create the total force on an object, and reinforce concepts and extend learning with sample problems.

  3. Study on the effect of ground motion direction on the response of engineering structure

    Science.gov (United States)

    Sun, Menghan; Fan, Feng; Sun, Baitao; Zhi, Xudong

    2016-12-01

    Due to the randomness of earthquake wave magnitude and direction, and the uncertain direction of strong axis and weak axis in the construction of engineering structures, the effect of the direction of ground motion on a structure are studied herein. Ground motion records usually contain three vertical ground motion data, which are obtained by sensors arranged in accordance with the EW (East -West) direction, NS (South- North) direction and perpendicular to the surface ( z) direction, referring to the construction standard of seismic stations. The seismic records in the EW and NS directions are converted to Cartesian coordinates in accordance with the rotation of θ = 0°-180°, and consequently, a countless group of new ground motion time histories are obtained. Then, the characteristics of the ground motion time history and response spectrum of each group were studied, resulting in the following observations: (1) the peak and phase of ground motion are changed with the rotation of direction θ, so that the direction θ of the maximum peak ground motion can be determined; (2) response spectrum values of each group of ground motions change along with the direction θ, and their peak, predominant period and declining curve are also different as the changes occur; then, the angle θ in the direction of the maximum peak value or the widest predominant period can be determined; and (3) the seismic response of structures with different directions of ground motion inputs has been analyzed under the same earthquake record, and the results show the difference. For some ground motion records, such as the Taft seismic wave, these differences are significant. Next, the Lushan middle school gymnasium structure was analyzed and the calculation was checked using the proposed method, where the internal force of the upper space truss varied from 25% to 28%. The research results presented herein can be used for reference in choosing the ground motion when checking the actual damage

  4. Sudden drop in ground support produces force-related unload response in human overground walking

    DEFF Research Database (Denmark)

    Af Klint, Richard; Nielsen, Jens Bo; Sinkjaer, Thomas

    2009-01-01

    healthy volunteers. Subjects walked unrestrained over a hydraulically actuated platform. On random trials the platform was accelerated downward at 0.8 g, unloading the plantar flexor muscles in midstance or late stance. The drop of the platform resulted in a significant depression of the soleus muscle...... was decreased starting 22 ms (SD 15) after the drop. To investigate the role of length- and velocity-sensitive afferents on the depression in soleus muscle activity, the ankle rotation was arrested by using an ankle foot orthotic as the platform was dropped. Preventing the ankle movement did not significantly...... change the soleus depression in late stance [-18.2% (SD 15)], whereas the depression in midstance was removed [+4.9% (SD 13)]. It is concluded that force feedback from ankle extensors increases the locomotor output through positive feedback in late stance. In midstance the effect of force feedback...

  5. A Systems Engineering Approach in Providing Air Defense Support to Ground Combat Vehicle Maneuver Forces

    Science.gov (United States)

    2015-03-01

    http://www.strategypage.com/dls/ articles /SLAMRAAM-Dies-From-Loneliness-2- 5-2011.asp. Federation of American Scientists . 2000. “M6 Bradley Linebacker...MANPADS-under-armor (MUA) concept was adopted to provide mobile air defense to maneuver forces (Federation of American Scientists 2000). This involved... swim in water. The functional hierarchy for the Move function is shown in Figure 17. 39 Figure 17. Functional Hierarchy for F.3 Move d

  6. You’ve got to be Kidding: Empowering the JFACC with Selected Ground Reconnaissance Forces

    Science.gov (United States)

    2007-11-02

    headquarters as well. The other organization that is a powerful aid to the success of airpower is the Joint Warfare Analysis Center (JWAC). This...organization made up of multidiscipline analysts, engineers, and scientists whose primary mission is to perform material-based systems analysis focused...Forces Attack” ( FOFA ) doctrine. While not mutually exclusive doctrines, they did create friction in whether the focus of air operations was the

  7. Transforming America’s Military: Integrating Unconventional Ground Forces into Combat Air Operations

    Science.gov (United States)

    2007-11-02

    the Vietnam War, Operation Desert One (the failed Iranian hostage rescue attempt), and Operation Urgent Fury (the disjointed Grenada operation) was...airpower could have in the upcoming operation to liberate Kuwait. The former commander of JSOC , Army General (Ret.) Wayne Downing, believed that “no...Operations Air Component Commander JSOC —Joint Special Operations Command JSOTF—Joint Special Operations Task Force 22 JSTARS—Joint Surveillance Target

  8. How Chairpersons Enhance Faculty Research: A Grounded Theory Study.

    Science.gov (United States)

    Creswell, John W.; Brown, Martha L.

    1992-01-01

    A study examined how department chairpersons enhanced research performance of college and university faculty. By applying grounded theory methods to a corpus of 33 interviews with chairpersons, the study resulted in a typology of chair roles (administrative, advocacy, interpersonal), then assessed the process of assistance for faculty at four…

  9. How Chairpersons Enhance Faculty Research: A Grounded Theory Study.

    Science.gov (United States)

    Creswell, John W.; Brown, Martha L.

    1992-01-01

    A study examined how department chairpersons enhanced research performance of college and university faculty. By applying grounded theory methods to a corpus of 33 interviews with chairpersons, the study resulted in a typology of chair roles (administrative, advocacy, interpersonal), then assessed the process of assistance for faculty at four…

  10. A Grounded Theory Study of Supervision of Preservice Consultation Training

    Science.gov (United States)

    Newman, Daniel S.

    2012-01-01

    The purpose of this study was to explore a university-based supervision process for consultants-in-training (CITs) engaged in a preservice level consultation course with applied practicum experience. The study was approached from a constructivist worldview using a grounded theory methodology. Data consisted of supervision session transcripts,…

  11. Air Force Support of Army Ground Operations Lessons Learned during World War II, Korea, and Vietnam

    Science.gov (United States)

    1989-03-06

    Th ;e 8epre--cdin this paper .rv thoe. of ’:ceauhor IDep 2rtmt-nt of Diefense rayo t gr: s hsPcC % FOC, O P 0- C GOUND OP!-txA’TONS ’A NS tTAI.D 11...NOTE S T edder, Wi.th Preudice: The War Memoirs . - y Air Force. Lord Tedaer. rr- 40-43. 2.".~ : X :"~ , M~.c, ’ = A r Power in Three Wars WW 7:, Kora...that FEAF assume operational control over land based Marine air units and over carri.er bjdsed aviation operating over Korea effective as soon as X

  12. A History of the Army Ground Forces; Study Number 16. The Army Ground Forces History of the Second Army

    Science.gov (United States)

    1945-09-01

    artillery with infantry was poor, orders were verbose, and time and space factors were not -sufficiently considered. Genera.. Fredndall observed pungently ...practicable, he must be subjected in training to every eight, sound, and sensation of battle. He must be trained to act calmly and with sound judgment

  13. EFFECTS OF FATIGUE ON FRONTAL PLANE KNEE MOTION, MUSCLE ACTIVITY, AND GROUND REACTION FORCES IN MEN AND WOMEN DURING LANDING

    Directory of Open Access Journals (Sweden)

    Michael P. Smith

    2009-09-01

    Full Text Available Women tear their Anterior Cruciate Ligament (ACL 2-8 times more frequently than men. Frontal plane knee motion can produce a pathological load in the ACL. During a state of fatigue the muscles surrounding the knee joint may lose the ability to protect the joint during sudden deceleration while landing. The purpose of this study was to investigate the effects of fatigue and gender on frontal plane knee motion, EMG amplitudes, and GRF magnitudes during drop- jump landing. Pretest-posttest comparison group design was used. Twenty-six volunteers (14 women; 12 Men; Mean ± standard deviation age = 24.5 ± 2.7 yrs; height = 1.73 ± 0.09 m; mass = 74.3 ± 11.8 kg participated in the study. Knee frontal plane ranges of motion and positions, ground reaction force peak magnitudes, and surface EMG RMS amplitudes from five lower extremity muscles (vastus medialis, vastus lateralis, medial hamstring, lateral hamstring, and lateral gastrocnemius were obtained during the landing phase of a drop-jump. MANOVA and ANOVA indicated that peak GRF significantly (p < 0.05; 2.50 ± 0.75 BW vs. 2.06 ± 0.93 BW decreased during fatigued landings. No other variables exhibited a fatigue main effect, although there was a significant (p < 0.05 fatigue by gender interaction for the frontal plane range of motion from initial contact to max knee flexion variable. Follow-up analyses failed to reveal significant gender differences at the different levels of fatigue for this variable. Additionally, no variables exhibited a significant gender main effect. Single subject analysis indicated that fatigue significantly altered frontal plane knee motion, peak GRF, and EMG in some subjects and the direction of differences varied by individual. Fatigue altered some aspects of landing performance in both men and women, but there were no gender differences. Additionally, both group and single subject analyses provided valuable but different information about factors representing

  14. Satisfaction with College Major: A Grounded Theory Study

    Science.gov (United States)

    Milsom, Amy; Coughlin, Julie

    2015-01-01

    All college students must eventually choose and complete a major. Many switch majors, and some change it multiple times. Despite extensive literature addressing factors that influence students' initial choice of major, few scholars have examined students' experiences after enrollment in a selected major. In this study, we used a grounded theory…

  15. Response to the society of toxicology task force re-examination of the ED01 study.

    Science.gov (United States)

    Kodell, R L; Gaylor, D W; Greenman, D L; Littlefield, N A; Farmer, J H

    1983-01-01

    This communication has re-examined and justified certain of the NCTR's analyses and recommendations from the ED01 Study, which were either misunderstood or misinterpreted by the SOT Task Force. In addition, we have shown that some of the Task Force's own analyses and interpretations are subject to review on scientific grounds. The Task Force's rejection of the linear extrapolation method recommended by the NCTR was stated because of a suspected force-fitting of a linear model to data, an approach that is not part of the NCTR procedure. In suspecting a protective effect of 2-AAF against bladder tumors, the Task Force used an inappropriate model that overpredicted the background bladder tumor rate in control mice. Contrary to the Task Force's belief, a failure to account adequately for time to tumor response was more characteristic of analyses performed by the Task Force rather than those performed by the NCTR. The Task Force's questioning of the multistage model for risk assessment was based on its use of inappropriate, crude tumor data rather than upon NCTR's use of the multistage model with time-adjusted tumor data. The Hartley-Sielken model did not fit the ED01 tumor data as well as the Task Force had presumed. In a risk extrapolation comparison by the Task Force, a coarse time partition of the ED01 data that had been questioned by the Task Force actually produced more stable results than a finer partition proposed by the Task Force. Another problem in the Task Force report concerns the change of protocol. Instead of resulting in a loss of strength as anticipated by the Task Force, the change of protocol during the ED01 Study resulted in an increase in information as alluded to by the Task Force. If the Task Force's proposal for restricting the length of feeding studies had been followed in the ED01 Study, most of the dose related tumor information would not have been obtained. Also, the Task Force's belief that low doses of 2-AAF had some effect on the

  16. Unattended wireless proximity sensor networks for counterterrorism, force protection, littoral environments, PHM, and tamper monitoring ground applications

    Science.gov (United States)

    Forcier, Bob

    2003-09-01

    This paper describes a digital-ultrasonic ground network, which forms an unique "unattended mote sensor system" for monitoring the environment, personnel, facilities, vehicles, power generation systems or aircraft in Counter-Terrorism, Force Protection, Prognostic Health Monitoring (PHM) and other ground applications. Unattended wireless smart sensor/tags continuously monitor the environment and provide alerts upon changes or disruptions to the environment. These wireless smart sensor/tags are networked utilizing ultrasonic wireless motes, hybrid RF/Ultrasonic Network Nodes and Base Stations. The network is monitored continuously with a 24/7 remote and secure monitoring system. This system utilizes physical objects such as a vehicle"s structure or a building to provide the media for two way secure communication of key metrics and sensor data and eliminates the "blind spots" that are common in RF solutions because of structural elements of buildings, etc. The digital-ultrasonic sensors have networking capability and a 32-bit identifier, which provide a platform for a robust data acquisition (DAQ) for a large amount of sensors. In addition, the network applies a unique "signature" of the environment by comparing sensor-to-sensor data to pick up on minute changes, which would signal an invasion of unknown elements or signal a potential tampering in equipment or facilities. The system accommodates satellite and other secure network uplinks in either RF or UWB protocols. The wireless sensors can be dispersed by ground or air maneuvers. In addition, the sensors can be incorporated into the structure or surfaces of vehicles, buildings, or clothing of field personnel.

  17. A comparative study of satellite and ground-based phenology.

    Science.gov (United States)

    Studer, S; Stöckli, R; Appenzeller, C; Vidale, P L

    2007-05-01

    Long time series of ground-based plant phenology, as well as more than two decades of satellite-derived phenological metrics, are currently available to assess the impacts of climate variability and trends on terrestrial vegetation. Traditional plant phenology provides very accurate information on individual plant species, but with limited spatial coverage. Satellite phenology allows monitoring of terrestrial vegetation on a global scale and provides an integrative view at the landscape level. Linking the strengths of both methodologies has high potential value for climate impact studies. We compared a multispecies index from ground-observed spring phases with two types (maximum slope and threshold approach) of satellite-derived start-of-season (SOS) metrics. We focus on Switzerland from 1982 to 2001 and show that temporal and spatial variability of the multispecies index correspond well with the satellite-derived metrics. All phenological metrics correlate with temperature anomalies as expected. The slope approach proved to deviate strongly from the temporal development of the ground observations as well as from the threshold-defined SOS satellite measure. The slope spring indicator is considered to indicate a different stage in vegetation development and is therefore less suited as a SOS parameter for comparative studies in relation to ground-observed phenology. Satellite-derived metrics are, however, very susceptible to snow cover, and it is suggested that this snow cover should be better accounted for by the use of newer satellite sensors.

  18. Community hoarding task forces: a comparative case study of five task forces in the United States.

    Science.gov (United States)

    Bratiotis, Christiana

    2013-05-01

    During the past decade, many community task forces have formed to address hoarding problems that come to public attention. Such task forces provide a societal-level intervention to assist people with the most severe cases of hoarding, who do not voluntarily seek or want help for their hoarding behaviour. This qualitative study of five U.S. hoarding task forces included sites selected for their diversity of purpose, approaches to hoarding intervention and community geography, composition and resources. Data were collected during the period of September 2007-March 2008. The case study methodology used multiple forms of data, including semi-structured interviews, analysis of documents, small group interviews and investigator observation. This study captured the perspectives of public and private sector service providers such as mental health, housing, social service, public health agencies and community enforcement organisations (fire, police, legal, animal control) to examine how task forces organise and operate and the emerging practice and policy changes. Study findings suggest that structural factors (e.g. leadership, purpose, funding and membership) impact hoarding task force viability, that participation on a task force influences practice and policy decisions about hoarding, and that social work can expand its role in task force leadership. Task forces may be a mechanism for improving community policies about hoarding and mechanisms for addressing other social problems across multiple sectors.

  19. Temporal coordination between ground reaction forces generated by leading and trailing limbs for propulsion during double stance phase in human walking.

    Science.gov (United States)

    Sato, Yoichiro; Yamada, Norimasa

    2017-05-01

    Although it was reported that ground reaction forces (GRFs) are generated simultaneously by the leading and trailing limbs during the double stance phase, the finding was not examined by temporal analyses. Therefore, the purpose of the present study is to clarify how GRFs can act to propel the body in a forward direction during the double stance phase. GRFs were recorded during the double stance phase in eleven healthy volunteers. We calculated the instantaneous phase of the GRFs for vertical and anterior-posterior (AP) components, and then calculated the relative phase between the leading and trailing limbs for each component. The relative phase of the vertical component was approximately 180° (i.e., anti-phase), indicating that the lower limb transfers weight smoothly from the trailing limb to the leading limb. The relative phase of the AP component ranged from 40 to 55°, indicating that the AP component of the forces do not occur simultaneously, but instead has a lag. This finding suggests that the forces exerted by the leading and trailing limbs would temporally coordinate to propel the body in the forward direction. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Ground-water conditions and studies in Georgia, 2001

    Science.gov (United States)

    Leeth, David C.; Clarke, John S.; Craigg, Steven D.; Wipperfurth, Caryl J.

    2003-01-01

    The U.S. Geological Survey (USGS) collects ground-water data and conducts studies to monitor hydrologic conditions, to better define ground-water resources, and address problems related to water supply and water quality. Data collected as part of ground-water studies include geologic, geophysical, hydraulic property, water level, and water quality. A ground-water-level network has been established throughout most of the State of Georgia, and ground-water-quality networks have been established in the cities of Albany, Savannah, and Brunswick and in Camden County, Georgia. Ground-water levels are monitored continuously in a network of wells completed in major aquifers of the State. This network includes 17 wells in the surficial aquifer, 12 wells in the upper and lower Brunswick aquifers, 73 wells in the Upper Floridan aquifer, 10 wells in the Lower Floridan aquifer and underlying units, 12 wells in the Claiborne aquifer, 1 well in the Gordon aquifer, 11 wells in the Clayton aquifer, 11 wells in the Cretaceous aquifer system, 2 wells in Paleozoic-rock aquifers, and 7 wells in crystalline-rock aquifers. In this report, data from these 156 wells were evaluated to determine whether mean-annual ground-water levels were within, below, or above the normal range during 2001, based on summary statistics for the period of record. Information from these summaries indicates that water levels during 2001 were below normal in almost all aquifers monitored, largely reflecting climatic effects from drought and pumping. In addition, water-level hydrographs for selected wells indicate that water levels have declined during the past 5 years (since 1997) in almost all aquifers monitored, with water levels in some wells falling below historical lows. In addition to continuous water-level data, periodic measurements taken in 52 wells in the Camden County-Charlton County area, and 65 wells in the city of Albany-Dougherty County area were used to construct potentiometric-surface maps for

  1. Ground-source heat pump case studies and utility programs

    Energy Technology Data Exchange (ETDEWEB)

    Lienau, P.J.; Boyd, T.L.; Rogers, R.L.

    1995-04-01

    Ground-source heat pump systems are one of the promising new energy technologies that has shown rapid increase in usage over the past ten years in the United States. These systems offer substantial benefits to consumers and utilities in energy (kWh) and demand (kW) savings. The purpose of this study was to determine what existing monitored data was available mainly from electric utilities on heat pump performance, energy savings and demand reduction for residential, school and commercial building applications. In order to verify the performance, information was collected for 253 case studies from mainly utilities throughout the United States. The case studies were compiled into a database. The database was organized into general information, system information, ground system information, system performance, and additional information. Information was developed on the status of demand-side management of ground-source heat pump programs for about 60 electric utility and rural electric cooperatives on marketing, incentive programs, barriers to market penetration, number units installed in service area, and benefits.

  2. Influence of pressure-relief insoles developed for loaded gait (backpackers and obese people) on plantar pressure distribution and ground reaction forces.

    Science.gov (United States)

    Peduzzi de Castro, Marcelo; Abreu, Sofia; Pinto, Viviana; Santos, Rubim; Machado, Leandro; Vaz, Mario; Vilas-Boas, João Paulo

    2014-07-01

    The aims of this study were to test the effects of two pressure relief insoles developed for backpackers and obese people on the ground reaction forces (GRF) and plantar pressure peaks during gait; and to compare the GRF and plantar pressures among normal-weight, backpackers, and obese participants. Based on GRF, plantar pressures, and finite element analysis two insoles were manufactured: flat cork-based insole with (i) corkgel in the rearfoot and forefoot (SLS1) and with (ii) poron foam in the great toe and lateral forefoot (SLS2). Gait data were recorded from 21 normal-weight/backpackers and 10 obese participants. The SLS1 did not influence the GRF, but it relieved the pressure peaks for both backpackers and obese participants. In SLS2 the load acceptance GRF peak was lower; however, it did not reduce the plantar pressure peaks. The GRF and plantar pressure gait pattern were different among the normal-weight, backpackers and obese participants.

  3. Ground Reaction Force Differences in the Countermovement Jump in Girls with Different Levels of Performance

    Science.gov (United States)

    Floría, Pablo; Harrison, Andrew J.

    2013-01-01

    Purpose: The aim of this study was to ascertain the biomechanical differences between better and poorer performers of the vertical jump in a homogeneous group of children. Method: Twenty-four girls were divided into low-scoring (LOW; M [subscript age] = 6.3 ± 0.8 years) and high-scoring (HIGH; M [subscript age] = 6.6 ± 0.8 years) groups based on…

  4. Study of Radiative Forcing of Dust Aerosols and its impact on Climate Characteristics

    KAUST Repository

    Qureshi, Fawwad H

    2012-12-01

    The purpose of following project is to study the effect of dust aerosols on the radiative forcing which is directly related to the surface temperature. A single column radiative convective model is used for simulation purpose. A series of simulations have been performed by varying the amount of dust aerosols present in the atmosphere to study the trends in ground temperature, heating rate and radiative forcing for both its longwave and shortwave components. A case study for dust storm is also performed as dust storms are common in Arabian Peninsula. A sensitivity analyses is also performed to study the relationship of surface temperature minimum and maximum against aerosol concentration, single scattering albedo and asymmetry factor. These analyses are performed to get more insight into the role of dust aerosols on radiative forcing.

  5. Do runners who suffer injuries have higher vertical ground reaction forces than those who remain injury-free? A systematic review and meta-analysis

    NARCIS (Netherlands)

    van der Worp, Henk; Vrielink, Jelte W.; Bredeweg, Steef W.

    2016-01-01

    Background Vertical ground reaction force (VGRF) parameters have been implicated as a cause of several running-related injuries. However, no systematic review has examined this relationship. Aim We systematically reviewed evidence for a relation between VGRF parameters and specific running-related i

  6. Do runners who suffer injuries have higher vertical ground reaction forces than those who remain injury-free? : A systematic review and meta-analysis

    NARCIS (Netherlands)

    van der Worp, Henk; Vrielink, Jelte W.; Bredeweg, Steef W.

    2016-01-01

    BACKGROUND: Vertical ground reaction force (VGRF) parameters have been implicated as a cause of several running-related injuries. However, no systematic review has examined this relationship. AIM: We systematically reviewed evidence for a relation between VGRF parameters and specific running-related

  7. The vertical ground reaction force and the pressure distribution on the claws of dairy cows while walking on a flat substrate

    NARCIS (Netherlands)

    Tol, van der P.P.J.; Metz, J.H.M.; Noordhuizen-Stassen, E.N.; Back, W.; Braam, C.R.; Weijs, W.A.

    2003-01-01

    The pressure distribution under the bovine claw while walking was measured to test the hypotheses that the vertical ground reaction force is unevenly distributed and makes some (regions of the) claws more prone to injuries due to overloading than others. Each limb of nine recently trimmed Holstein F

  8. Physical fitness and nutritional status of polish ground force unit recruits.

    Science.gov (United States)

    Tomczak, A; Bertrandt, J; Kłos, A

    2012-12-01

    The purpose of the work was to conduct an examination of the physical fitness and nutritional status of recruits (221 men beginning military service in the infantry unit). Soldiers' physical efficiency was estimated using 4 tests: standing long jump, pull-ups on bar, 30-second sit-ups and 1000-metre run. The nutritional status assessment was done based on anthropometric measurements including measurements of body height, body mass and selected skin fold thickness. The study group of soldiers were the best at sit-ups (46.33 points). They got over 40 points for the 1000-metre run (43.68 points) and for pull-ups on bar (41.69 points). They obtained the lowest scores for standing long jumps (30.77 points). About 14% of recruits were overweight and 4.1% underweight. Recruits enrolling in the infantry unit present a low physical fitness level. Overweight and obesity occurrence, and particularly underweight, in recruits testify to improper nutrition before beginning military service.

  9. Intermolecular forces between acetylcholine and acetylcholinesterases studied with atomic force microscopy

    Institute of Scientific and Technical Information of China (English)

    张英鸽; 白春礼; 王琛; 赵德禄; 苏明; 林璋; 田芳

    1999-01-01

    With the aid of atomic force microscopy, the intermolecular forces between acetyleholinesterases (AChE) and its natural substrate acetylcholine (ACh) have been studied. Through force spectrum measurement based on imaging of AChE molecules it was found that the attraction force between individual molecule pairs of ACh and AChE was (10±1) pN just before the quaternary ammonium head of ACh got into contact with the negative end of AChE and the decaying distance of attraction was (4±1) nm from the surface of ACHE. The adhesion force between individual ACh and AChE molecule pairs was (25±2) pN, which had a decaying feature of fast-slow-fast (FSF). The attraction forces between AChE and choline (Ch), the quaternary ammonium moiety and hydrolysate of ACh molecule, were similar to those between AChE and ACh. The adhesion forces between AChE and Ch were (20±2) pN, a little weaker than that between ACh and ACHE. These results indicated that AChE had a steering role for the diffusion of ACh toward it and had r

  10. Vertical ground reaction force responses to different head-out aquatic exercises performed in water and on dry land.

    Science.gov (United States)

    Alberton, Cristine Lima; Finatto, Paula; Pinto, Stephanie Santana; Antunes, Amanda Haberland; Cadore, Eduardo Lusa; Tartaruga, Marcus Peikriszwili; Kruel, Luiz Fernando Martins

    2015-01-01

    The purpose was to analyse the vertical ground reaction forces (Fz) of head-out aquatic exercises [stationary running (SR), frontal kick (FK), cross-country skiing (CCS), jumping jacks (JJ), adductor hop (ADH) and abductor hop (ABH)] at two cadences in both aquatic and dry land environments. Twelve young women completed two sessions in each environment, each consisting of three exercises performed at two cadences (first and second ventilatory thresholds - C1 and C2, respectively). Two-way and three-way repeated measures analysis of variance were used to the statistical analysis. The results showed that the peak Fz and impulse were significantly lower in the aquatic environment, resulting in values from 28.2% to 58.5% and 60.4% to 72.8% from those obtained on dry land, respectively. In the aquatic environment, the peak Fz was lower and the impulse was higher at the C1 than at the C2. Furthermore, it was observed that SR and FK (0.9-1.1 BW) elicited a significantly higher peak Fz values compared to the ADH and JJ exercises (0.5-0.8 BW). It can be concluded that the aquatic environment reduces the Fz during head-out aquatic exercises. It should be noted that its magnitude is also dependent on the intensity and the identity of the exercise performed.

  11. Ground-water levels and water-quality data for wells in the Spring Creek area near Arnold Air Force Base, Tennessee, April and May 2000

    Science.gov (United States)

    Williams, Shannon D.; Aycock, Robert A.

    2001-01-01

    Arnold Air Force Base (AAFB) occupies about 40,000 acres in Coffee and Franklin Counties, Tennessee. Numerous site-specific ground-water contamination investigations have been conducted at designated solid waste management units (SWMU?s) at AAFB. Several synthetic volatile organic compounds (VOC?s), primarily chlorinated solvents, have been identified in groundwater samples collected from monitoring wells near SWMU 8 in the Spring Creek area. During April and May 2000, a study of the groundwater resources in the Spring Creek area was conducted to determine if VOC?s from AAFB have affected local private water supplies and to advance understanding of the ground-water-flow system in this area. The study focused on sampling private wells located within the Spring Creek area that are used as a source of drinking water. Ground-water-flow directions were determined by measuring water levels in wells and constructing a potentiometric-surface map of the Manchester aquifer in the study area. Data were collected from a total of 35 private wells and 22 monitoring wells during the period of study. Depths to ground water were determined for 22 of the private wells and all 22 of the monitoring wells. The wells ranged in depth from 21 to 105 feet. Water-level altitudes ranged from 930 to 1,062 feet above sea level. Depths to water ranged from 8 to 83 feet below land surface. Water-quality samples were collected from 29 private wells which draw water from either gravel zones in the upper part of the Manchester aquifer, fractured bedrock in the lower part of the Manchester aquifer, or a combination of these two zones. Concentrations of 50 of the 55 VOC?s analyzed for were less than method detection limits. Chloroform, acetone, chloromethane, 2-butanone, and tetrachloroethylene were detected in concentrations exceeding the method detection limits. Only chloroform and acetone were detected in concentrations equal to or exceeding reporting limits. Chloroform was detected in a sample

  12. Computational Studies of Lobed Forced Mixer Flows

    Institute of Scientific and Technical Information of China (English)

    H.Hu; S.C.M.Yu; 等

    1998-01-01

    Full Navier-Stokes Analyses have been conducted for the flows behind the trailing edge of a lobed forced mixer,The governing equations are derived from the time-dependent compressible Navier-Stokes equations and discretized in the finite-difference form.A simple two-layer eddy viscosity model has also been used to account for the turbulence.Computed results are compared with some of the velocity measurements using a laser-Doppler anemomter(Yu and Yip (1997),In General,good agreement can be obtained in the streamwise mean velocity distribution but the decay of the streamwise circulation is underpredicted.Some suggestions to the discrepancy are proposed.

  13. Apical force distribution due to orthodontic forces: a finite element study.

    Science.gov (United States)

    Mathur, Anirudh K; Gupta, Vikas; Sarmah, Anirban; Pai, Vinaya S; Chandrashekar, G

    2011-03-01

    This finite element study was conducted to calculate the distribution of stresses in the periodontal ligament when various orthodontic forces were applied, with emphasis on the effect on root apex. An in vitro finite element method was used to construct a three-dimensional finite element model of a maxillary central incisor, its periodontal ligament and alveolar bone was constructed on the basis of average anatomic morphology. To this model, five types of orthodontic forces namely tipping, bodily movement, intrusion, extrusion and rotations were applied at various points on the crown of the tooth model. After the application of the forces, initial stress and initial displacements of the periodontal ligament were evaluated. The principal stress obtained on the periodontal ligament due to various orthodontic loadings on the maxillary central incisor was analyzed using ANSYS 10 finite element software. It showed that the greatest amount of relative stress at the apex of maxillary central incisor occurred with intrusion, extrusion and rotation. Bodily movement and tipping forces produce stress concentrated at the alveolar crest and not at the root apex. Clinical implications of this study suggest that if the clinician is concerned about placing heavy stresses on the root apex, then vertical and rotational forces must be applied with caution. If heavy stresses are to be placed on the root apex, then vertical and rotational forces must be applied with caution during orthodontic therapy.

  14. Assessment of dairy cow locomotion in a commercial farm setting: the effects of walking speed on ground reaction forces and temporal and linear stride characteristics.

    Science.gov (United States)

    Walker, A M; Pfau, T; Channon, A; Wilson, A

    2010-02-01

    Objectives of this study were to determine the effects of walking speed on ground reaction force (GRF) parameters and to explore inter- and intra-individual variability with unsupervised data collection in a commercial farm setting. We used eight high producing loose-housed Holstein Friesian cows consistently scored sound, with no veterinary treatment during the collection period. Cows walked freely (0.52-1.37 m/s) over a five force platform array, twice daily, following milking. GRF data were split into speed categories and temporal and kinetic gait parameters extracted. A general linear model was carried out to determine effects of speed. Variation in parameters between cows is inconsistent, while between speed categories (containing data from multiple cows) the parameters which vary are consistent. Stance and stride time were reduced with increasing speed but no change in peak vertical GRF or duty factor was found. This ability to track parameters within an individual over time aids detection of subtle changes associated with lameness. Copyright 2009 Elsevier Ltd. All rights reserved.

  15. Experimental study on working parameters of earth pressure balance shield machine tunneling in soft ground

    Institute of Scientific and Technical Information of China (English)

    Hehua ZHU; Shaoming LIAO; Qianwei XU; Qizhen ZHENG

    2008-01-01

    Deep sedimentary deposits of soft clays are widely distributed in coastal areas as well as many interior major cities in China. In order to study the stratum adapt-ability of earth pressure balance (EPB) shield machine tunneling in such types of soft ground, model tests of tunneling excavation, using the running tunnel of the Shanghai Metro Line M8 as a background, are carried out with different over burden ratios, opening rates of cutter head, driving speeds and rotation speeds of screw conveyor. Based on the test results, the interrelationships between chamber pressure and mucking efficiency, muck-ing rate and driving speed, thrust force and torque are obtained. The influences of tunnel depth, opening rate of cutter head and driving speed on thrust force and tor-que are revealed. Such findings can not only facilitate establishing relationships between shield working para-meters and soil properties, but also serve as a guide for the design and construction of shield tunnel in soft ground.

  16. Concurrent validity and reliability of using ground reaction force and center of pressure parameters in the determination of leg movement initiation during single leg lift.

    Science.gov (United States)

    Aldabe, Daniela; de Castro, Marcelo Peduzzi; Milosavljevic, Stephan; Bussey, Melanie Dawn

    2016-09-01

    Postural adjustment evaluations during single leg lift requires the initiation of heel lift (T1) identification. T1 measured by means of motion analyses system is the most reliable approach. However, this method involves considerable workspace, expensive cameras, and time processing data and setting up laboratory. The use of ground reaction forces (GRF) and centre of pressure (COP) data is an alternative method as its data processing and setting up is less time consuming. Further, kinetic data is normally collected using frequency samples higher than 1000Hz whereas kinematic data are commonly captured using 50-200Hz. This study describes the concurrent-validity and reliability of GRF and COP measurements in determining T1, using a motion analysis system as reference standard. Kinematic and kinetic data during single leg lift were collected from ten participants. GRF and COP data were collected using one and two force plates. Displacement of a single heel marker was captured by means of ten Vicon(©) cameras. Kinetic and kinematic data were collected using a sample frequency of 1000Hz. Data were analysed in two stages: identification of key events in the kinetic data, and assessing concurrent validity of T1 based on the chosen key events with T1 provided by the kinematic data. The key event presenting the least systematic bias, along with a narrow 95% CI and limits of agreement against the reference standard T1, was the Baseline COPy event. Baseline COPy event was obtained using one force plate and presented excellent between-tester reliability.

  17. Forcing an entire bifurcation diagram: Case studies in chemical oscillators

    Science.gov (United States)

    Kevrekidis, I. G.; Aris, R.; Schmidt, L. D.

    1986-12-01

    We study the finite amplitude periodic forcing of chemical oscillators. In particular, we examine systems that, when autonomous, (i.e. for zero forcing amplitude) exhibit a single stable oscillation. Using one of the system parameters as a forcing variable by varying it periodically, we show through extensive numerical work how the bifurcation diagram of the autonomous system with respect to this parameter affects the qualitative response of the full forced system. As the forcing variable oscillates around its midpoint, its instantaneous values may cross points (such as Hopf bifurcation poiints) of the autonomous bifurcation diagram so that the characterization of the system as a simple forced oscillator is no longer valid. Such a neighboring Hopf bifurcation of the unforced system is found to set the scene for the interaction of resonance horns and the loss of tori in the full forced system as the amplitude of the forcing grows. Our test case presented here is the Continuous Stirred Tank Reactor (CSTR) with periodically forced coolant temperature.

  18. Newly-graduated midwives transcending barriers: a grounded theory study.

    Science.gov (United States)

    Barry, Michele J; Hauck, Yvonne L; O'Donoghue, Thomas; Clarke, Simon

    2013-12-01

    Midwifery has developed its own philosophy to formalise its unique identity as a profession. Newly-graduated midwives are taught, and ideally embrace, this philosophy during their education. However, embarking in their career within a predominantly institutionalised and the medically focused health-care model may challenge this application. The research question guiding this study was as follows: 'How do newly graduated midwives deal with applying the philosophy of midwifery in their first six months of practice?' The aim was to generate a grounded theory around this social process. This Western Australian grounded theory study is conceptualised within the social theory of symbolic interactionism. Data were collected by means of in-depth, semi-structured interviews with 11 recent midwifery graduates. Participant and interviewer's journals provided supplementary data. The 'constant comparison' approach was used for data analysis. The substantive theory of transcending barriers was generated. Three stages in transcending barriers were identified: Addressing personal attributes, Understanding the 'bigger picture', and finally, 'Evaluating, planning and acting' to provide woman-centred care. An overview of these three stages provides the focus of this article. The theory of transcending barriers provides a new perspective on how newly-graduated midwives deal with applying the philosophy of midwifery in their first six months of practice. A number of implications for pre and post registration midwifery education and policy development are suggested, as well as recommendations for future research. Copyright © 2013 Elsevier Ltd. All rights reserved.

  19. Influence of force feedback on grasp force modulation in prosthetic applications: a preliminary study.

    Science.gov (United States)

    Godfrey, Sasha B; Bianchi, Matteo; Bicchi, Antonio; Santello, Marco

    2016-08-01

    In typical movement, humans use a combination of feed-forward and feedback motor control strategies to interact with the world around them. However, when sensory input is impaired or absent, as in the case of various neuropathies or amputation, the ability to perform everyday tasks, like modulating grip force to object weight, can be affected. In this study, we show the results of a preliminary study using a pressure cuff-like force feedback device (CUFF) with the SoftHand Pro (SHP) prosthetic hand. Subjects lifted an object of various weights using their own hand, with the SHP without feedback, and the SHP with force feedback. As expected, significant differences were found between the two SHP conditions and the native hand, but surprisingly not between the SHP conditions. A closer look at the data suggests the feedback may help diminish the overall grip force used during grasping even if it does not alter the grip force modulation to object weight. The lack of significance may be due in part to high intra- and inter-subject variability. Additional training with the CUFF and/or customization of the feedback may enhance the effects and warrants further study.

  20. A study on forces acting on a flapping wing

    Directory of Open Access Journals (Sweden)

    Cetiner O.

    2013-04-01

    Full Text Available In order to study the forces acting on a flapping wing, an experimental investigation is performed in steady water flow. In this study, a SD7003 airfoil undergoes combined pitching and plunging motion which simulates the forward flight of small birds. The frequency of pitching motion is equal to the frequency of plunging motion and pitch leads the plunge by a phase angle of 90 degrees. The experiments are conducted at Reynolds numbers of 2500 ≤ Re ≤ 13700 and the vortex formation is recorded using the digital particle image velocimetry (DPIV technique. A prediction of thrust force and efficiency is calculated from the average wake deficit of DPIV data, the near-wake vorticity patterns and time dependent velocity vectors are determined to comment on the thrust and drag indication. Direct force measurements are attempted using a Force/Torque sensor which is capable of measuring forces and moments in three axial directions.

  1. Statistical Studies of Ground-Based Optical Lightning Signatures

    Science.gov (United States)

    Hunt, C. R.; Nemzek, R. J.; Suszcynsky, D. M.

    2005-12-01

    Most extensive optical studies of lightning have been conducted from orbit, and the statistics of events collected from earth are relatively poorly documented. The time signatures of optical power measured in the presence of clouds are inevitably affected by scattering,which can distort the signatures by extending and delaying the amplitude profile in time. We have deployed two all-sky photodiode detectors, one in New Mexico and one in Oklahoma, which are gathering data alongside electric field change monitors as part of the LANL EDOTX Great Plains Array. Preliminary results show that the photodiode is sensitive to approximately 50% or more of RF events detected at ranges of up to 30 km, and still has some sensitivity at ranges in excess of 60 km (distances determined by the EDOTX field-change array). The shapes of events within this range were assessed, with focus on rise time, width, peak power, and their correlation to corresponding electric field signatures, and these are being compared with published on-orbit and ground-based data. Initial findings suggest a mean characteristic width (ratio of total detected optical energy to peak power) of 291 +/- 12 microseconds and a mean delay between the RF signal peak and optical peak of 121 +/- 17 microseconds. These values fall between prior ground-based measurements of direct return stroke emissions, and scattering-dominated on-orbit measurements. This work will promote better understanding of the correspondence between radio and optical measurements of lightning.

  2. How to do a grounded theory study: a worked example of a study of dental practices

    Directory of Open Access Journals (Sweden)

    Evans R

    2011-09-01

    Full Text Available Abstract Background Qualitative methodologies are increasingly popular in medical research. Grounded theory is the methodology most-often cited by authors of qualitative studies in medicine, but it has been suggested that many 'grounded theory' studies are not concordant with the methodology. In this paper we provide a worked example of a grounded theory project. Our aim is to provide a model for practice, to connect medical researchers with a useful methodology, and to increase the quality of 'grounded theory' research published in the medical literature. Methods We documented a worked example of using grounded theory methodology in practice. Results We describe our sampling, data collection, data analysis and interpretation. We explain how these steps were consistent with grounded theory methodology, and show how they related to one another. Grounded theory methodology assisted us to develop a detailed model of the process of adapting preventive protocols into dental practice, and to analyse variation in this process in different dental practices. Conclusions By employing grounded theory methodology rigorously, medical researchers can better design and justify their methods, and produce high-quality findings that will be more useful to patients, professionals and the research community.

  3. Unsteady-State Grinding Technology (II) Experimental Studies of Grinding Forces and Force Ratio

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    As is known to all, grinding force is one of the most important parameters to evaluate the whole process of grinding. Generally, the grinding force is resolved to three component forces, namely, normal grinding force F n, tangential grinding force F t and a component force acting along the direction of longitudinal feed which is usually neglected because of insignificance. The normal grinding force F n has influence upon surface deformation and roughness of workpiece, while the tangential grinding force ...

  4. Study on equivalent velocity pulse of nearfault ground motions

    Institute of Scientific and Technical Information of China (English)

    李新乐; 朱晞

    2004-01-01

    Near-fault strong ground motions that resulted in serious structural damage are characterized by directivity effect and pulse-type motion. Large-amplitude and long-period pulses are contained in the velocity time-history traces of near-fault pulse-type records. A reasonable model of equivalent velocity pulse is proposed on the basis of the existed models in this paper to simplify the calculation and analysis. Based on the large amount of collected near-fault strong earthquakes records, the parameters describing equivalent velocity pulse model such as pulse period, pulse intensity and number of predominant pulses are studied, and comparison is made with the results obtained by others models. The proposed model is contributive to the seismic design for structures in near-fault areas.

  5. Assertiveness process of Iranian nurse leaders: a grounded theory study.

    Science.gov (United States)

    Mahmoudirad, Gholamhossein; Ahmadi, Fazlollah; Vanaki, Zohreh; Hajizadeh, Ebrahim

    2009-06-01

    The purpose of this study was to explore the assertiveness process in Iranian nursing leaders. A qualitative design based on the grounded theory approach was used to collect and analyze the assertiveness experiences of 12 nurse managers working in four hospitals in Iran. Purposeful and theoretical sampling methods were employed for the data collection and selection of the participants, and semistructured interviews were held. During the data analysis, 17 categories emerged and these were categorized into three themes: "task generation", "assertiveness behavior", and "executive agents". From the participants' experiences, assertiveness theory emerged as being fundamental to the development of a schematic model describing nursing leadership behaviors. From another aspect, religious beliefs also played a fundamental role in Iranian nursing leadership assertiveness. It was concluded that bringing a change in the current support from top managers and improving self-learning are required in order to enhance the assertiveness of the nursing leaders in Iran.

  6. Becoming an Older Volunteer: A Grounded Theory Study

    Directory of Open Access Journals (Sweden)

    Janet Witucki Brown

    2011-01-01

    Full Text Available This Grounded Theory study describes the process by which older persons “become” volunteers. Forty interviews of older persons who volunteered for Habitat for Humanity were subjected to secondary content analysis to uncover the process of “becoming” a volunteer. “Helping out” (core category for older volunteers occurs within the context of “continuity”, “commitment” and “connection” which provide motivation for volunteering. When a need arises, older volunteers “help out” physically and financially as health and resources permit. Benefits described as “blessings” of volunteering become motivators for future volunteering. Findings suggest that older volunteering is a developmental process and learned behavior which should be fostered in older persons by personally inviting them to volunteer. Intergenerational volunteering projects will allow older persons to pass on knowledge and skills and provide positive role modeling for younger volunteers.

  7. Marshaling Resources: A Classic Grounded Theory Study of Online Learners

    Directory of Open Access Journals (Sweden)

    Barbara Yalof

    2014-06-01

    Full Text Available Classic grounded theory (CGT was used to identify a main concern of online students in higher education. One of the main impediments to studying online is a sense of isolation and lack of access to support systems as students navigate through complex requirements of their online programs. Hypothetical probability statements illustrate the imbalance between heightened needs of virtual learners and perceived inadequate support provided by educational institutions. The core variable, marshaling resources, explains how peer supports sustain motivation toward successful program completion. Understanding the critical contribution virtual interpersonal networks make towards maximizing resources by group problem solving is a significant aspect of this theory. Keywords: Online learning, e-learning, personal learning networks, peer networks

  8. ANALYSIS OF THE VERTICAL GROUND REACTION FORCES AND TEMPORAL FACTORS IN THE LANDING PHASE OF A COUNTERMOVEMENT JUMP

    Directory of Open Access Journals (Sweden)

    Daniel Rojano Ortega

    2010-06-01

    Full Text Available In most common bilateral landings of vertical jumps, there are two peak forces (F1 and F2 in the force-time curve. The combination of these peak forces and the high frequency of jumps during sports produce a large amount of stress in the joints of the lower limbs which can be determinant of injury. The aim of this study was to find possible relationships between the jump height and F1 and F2, between F1 and F2 themselves, and between F1, F2, the time they appear (T1 and T2, respectively and the length of the impact absorption phase (T. Thirty semi-professional football players made five countermovement jumps and the highest jump of each player was analyzed. They were instructed to perform the jumps with maximum effort and to land first with the balls of their feet and then with their heels. All the data were collected using a Kistler Quattro Jump force plate with a sample rate of 500 Hz. Quattro Jump Software, v.1.0.9.0., was used. There was neither significant correlation between T1 and F1 nor between T1 and F2. There was a significant positive correlation between flight height (FH and F1 (r = 0.584, p = 0.01 but no significant correlation between FH and F2. A significant positive correlation between F1 and T2 (r = 0.418, p < 0.05 and a significant negative correlation between F2 and T2 (r = -0.406, p < 0.05 were also found. There is a significant negative correlation between T2 and T (r = -0. 443, p < 0.05. T1 has a little effect in the impact absorption process. F1 increases with increasing T2 but F2 decreases with increasing T2. Besides, increasing T2, with the objective of decreasing F2, makes the whole impact absorption shorter and the jump landing faster.

  9. Report of NASA Lunar Energy Enterprise Case Study Task Force

    Science.gov (United States)

    Kearney, John J.

    1989-01-01

    The Lunar Energy Enterprise Case Study Task Force was asked to determine the economic viability and commercial potential of mining and extracting He-3 from the lunar soil, and transporting the material to Earth for use in a power-generating fusion reactor. Two other space energy projects, the Space Power Station (SPS) and the Lunar Power Station (LPS), were also reviewed because of several interrelated aspects of these projects. The specific findings of the Task Force are presented. Appendices contain related papers generated by individual Task Force Members.

  10. Use of empathy in psychiatric practice: constructivist grounded theory study

    Science.gov (United States)

    Watling, Chris

    2017-01-01

    Background Psychiatry has faced significant criticism for overreliance on the Diagnostic and Statistical Manual of Mental Disorders (DSM) and medications with purported disregard for empathetic, humanistic interventions. Aims To develop an empirically based qualitative theory explaining how psychiatrists use empathy in day-to-day practice, to inform practice and teaching approaches. Method This study used constructivist grounded theory methodology to ask (a) ‘How do psychiatrists understand and use empathetic engagement in the day-to-day practice of psychiatry?’ and (b) ‘How do psychiatrists learn and teach the skills of empathetic engagement?’ The authors interviewed 17 academic psychiatrists and 4 residents and developed a theory by iterative coding of the collected data. Results This constructivist grounded theory of empathetic engagement in psychiatric practice considered three major elements: relational empathy, transactional empathy and instrumental empathy. As one moves from relational empathy through transactional empathy to instrumental empathy, the actions of the psychiatrist become more deliberate and interventional. Conclusions Participants were described by empathy-based interventions which are presented in a theory of ’empathetic engagement’. This is in contrast to a paradigm that sees psychiatry as purely based on neurobiological interventions, with psychotherapy and interpersonal interventions as completely separate activities from day-to-day psychiatric practice. Declaration of interest None. Copyright and usage © The Royal College of Psychiatrists 2017. This is an open access article distributed under the terms of the Creative Commons Non-Commercial, No Derivatives (CC BY-NC-ND) license. PMID:28243463

  11. Effects of the tensor force on the ground and first $2^{+}$ states of the magic $^{54}$Ca nucleus

    CERN Document Server

    Yüksel, E; Khan, E; Bozkurt, K

    2014-01-01

    The magic nature of the $^{54}$Ca nucleus is investigated in the light of the recent experimental results. We employ both HFB and HF+BCS methods using Skyrme-type SLy5, SLy5+T and T44 interactions. The evolution of the single-particle spectra is studied for the N=34 isotones: $^{60}$Fe, $^{58}$Cr, $^{56}$Ti and $^{54}$Ca. An increase is obtained in the neutron spin-orbit splittings of $p$ and $f$ states due to the effect of the tensor force which also makes $^{54}$Ca a magic nucleus candidate. QRPA calculations on top of HF+BCS are performed to investigate the first $J^{\\pi}$=$2^{+}$ states of the calcium isotopic chain. A good agreement for excitation energies is obtained when we include the tensor force in the mean-field part of the calculations. The first $2^{+}$ states indicate a subshell closure for both $^{52}$Ca and $^{54}$Ca nuclei. We confirm that the tensor part of the interaction is quite essential in explaining the neutron subshell closure in $^{52}$Ca and $^{54}$Ca nuclei.

  12. 基于足地接触力跟踪的单足机器人弹跳运动控制%Hopping Control of Single leg Robot on Compliant Ground Based on Ground Force Control

    Institute of Scientific and Technical Information of China (English)

    尹鹏; 李满天; 王俊; 查富生; 孙立宁

    2015-01-01

    The performance of legged hopping robot is subjected to the influence of the ground stiffness feature during the contact phase.To avoid the influence and insulate the ground stiffness disturbance we first established the simplified single leg hopping model with elastic featured ground,then an analysis about the relation of ground stiffness with moving trajectory and contact force profile is made.Based on this a control strategy to utilized to compensate the ground contact force to be the same as that of an undisturbed system via active extension or retraction of the leg during contact.The validity is demonstrated by simulation result.%为了使足式弹跳机器人在运动中避免由于地面接触刚度的变化对弹跳运动产生的影响,首先建立了单足弹跳机器人在弹性地面条件下的运动简化模型,进而分析了地面弹簧刚度变化对机体重心运动轨迹以及着地相中足地接触力的影响。采用足地接触力补偿控制的手段,通过主动控制单腿的伸缩,使模型中弹簧系统的足力输出与期望保持一致,消除了地面刚度变化对机体运动的干扰。利用仿真实验表明了控制方法的可行性。

  13. Are buckling force measurements reliable in nocturnal penile tumescence studies?

    Science.gov (United States)

    Nofzinger, E A; Fasiczka, A L; Thase, M E; Reynolds, C F; Frank, E; Jennings, J R; Garamoni, G L; Matzzie, J V; Kupfer, D J

    1993-02-01

    The study of nocturnal penile tumescence (NPT) is frequently used to evaluate male erectile dysfunction. Buckling force, a measure of rigidity, is an important part of this evaluation, but its reliability is unknown. Accordingly, we studied the reliability of buckling force measurement and the stability of "maximum buckling force" between consecutive NPT series repeated in the same subject. For individual subjects, we correlated buckling forces for separate episodes of sleep-related tumescence that were of comparable fullness (0-100%) as rated by a technician's visual estimates. For healthy control subjects, test-retest correlations were > 0.8 both within-night and across study series separated by an average of 70 weeks. In depressed men, correlations within nights were > 0.9, but fell to 0.64 across study series separated by an average of 21 weeks. Despite the high reliability of buckling force measurement, we found little stability of "maximum buckling force" between NPT series for individual subjects. Considerable variability in the maximum degree of penile rigidity was seen over time despite a constant level of reported daytime erectile function. We conclude that although penile rigidity is one of the more important variables in the assessment of male erectile dysfunction and can be measured reliably, the instability of maximum rigidity during sleep-related erections suggests that it is, at best, an imprecise correlate of daytime erectile function.

  14. Force-Depending Radiation Reaction study in an undulator devise

    CERN Document Server

    López, Gustavo V

    2016-01-01

    The effect of force-depending radiation reaction on charge motion traveling inside an undulator is studied using the new force approach for radiation reaction. The effect on the dynamics of a charged particle is determined with the hope that this one can be measured experimentally and can be determined whether or not this approach points on the right direction to understand the nature of radiation reaction.

  15. Lower limb joint angles and ground reaction forces in forefoot strike and rearfoot strike runners during overground downhill and uphill running.

    Science.gov (United States)

    Kowalski, Erik; Li, Jing Xian

    2016-11-01

    This study investigated the normal and parallel ground reaction forces during downhill and uphill running in habitual forefoot strike and habitual rearfoot strike (RFS) runners. Fifteen habitual forefoot strike and 15 habitual RFS recreational male runners ran at 3 m/s ± 5% during level, uphill and downhill overground running on a ramp mounted at 6° and 9°. Results showed that forefoot strike runners had no visible impact peak in all running conditions, while the impact peaks only decreased during the uphill conditions in RFS runners. Active peaks decreased during the downhill conditions in forefoot strike runners while active loading rates increased during downhill conditions in RFS runners. Compared to the level condition, parallel braking peaks were larger during downhill conditions and parallel propulsive peaks were larger during uphill conditions. Combined with previous biomechanics studies, our findings suggest that forefoot strike running may be an effective strategy to reduce impacts, especially during downhill running. These findings may have further implications towards injury management and prevention.

  16. Dynamical study of low Earth orbit debris collision avoidance using ground based laser

    Directory of Open Access Journals (Sweden)

    N.S. Khalifa

    2015-06-01

    Full Text Available The objective of this paper was to investigate the orbital velocity changes due to the effect of ground based laser force. The resulting perturbations of semi-major axis, miss distance and collision probability of two approaching objects are studied. The analytical model is applied for low Earth orbit debris of different eccentricities and area to mass ratio and the numerical test shows that laser of medium power ∼5 kW can perform a small change ΔV‾ of an average magnitude of 0.2 cm/s which can be accumulated over time to be about 3 cm/day. Moreover, it is confirmed that applying laser ΔV‾ results in decreasing collision probability and increasing miss distance in order to avoid collision.

  17. Studying the Formation Mechanism of New Ground Strike Points in Natural Negative Cloud-to-Ground Lightning

    Science.gov (United States)

    Campos, L. Z. D. S.; Cummins, K. L.; Pinto, O., Jr.

    2015-12-01

    Data from three-dimensional VHF mapping, high-speed video and slow electric field antenna of multiple ground contact flashes (MGCFs) have been analyzed in an attempt to characterize the process through which new ground terminations in natural lightning are formed. The three-dimensional VHF mapping data (obtained by a Lightning Mapping Array, LMA) provided valuable information on the processes that occurred inside the cloud during the interval between strokes. Detailed case studies of over 30 MGCFs observed in the vicinity of a wind farm in Kansas, USA, have allowed the identification and qualitative description of three mechanisms through which a given flash may touch ground at different locations. In events of Type I, the dart leader that initiates the subsequent stroke starts in the original channel and then diverges from the original path of the first stroke, ionizing a new channel and reaching ground at a different location. In high-speed video records, these events eventually have their "diverging" point visible below cloud base and their strike locations are separated by a few hundreds of meters. Type II, on the other hand, comprises flashes in which the subsequent stroke is initiated in an in-cloud branch that is farther from the inception region of the first return stroke, moving in another direction and touching ground at farther distances (up to more than 10 km from the initial strike location). Finally, Type III flashes typically gave rise to several return strokes, each with different ground strike points. Stepped leaders initiated in the same general region in the cloud give rise to these strokes with typical interstroke intervals below 100 milliseconds but no common channel branches among them could be conclusively identified. Representative events of each type are discussed in detail.

  18. Size Distributions and Characterization of Native and Ground Samples for Toxicology Studies

    Science.gov (United States)

    McKay, David S.; Cooper, Bonnie L.; Taylor, Larry A.

    2010-01-01

    This slide presentation shows charts and graphs that review the particle size distribution and characterization of natural and ground samples for toxicology studies. There are graphs which show the volume distribution versus the number distribution for natural occurring dust, jet mill ground dust, and ball mill ground dust.

  19. A study of the acoustical radiation force considering attenuation

    Science.gov (United States)

    Wu, RongRong; Liu, XiaoZhou; Gong, XiuFen

    2013-07-01

    Acoustical tweezer is a primary application of the radiation force of a sound field. When an ultrasound focused beam passes through a micro-particle, like a cell or living biological specimens, the particle will be manipulated accurately without physical contact and invasion, due to the three-dimensional acoustical trapping force. Based on the Ray acoustics approach in the Mie regime, this work discusses the effects on the particle caused by Gaussian focused ultrasound, studies the acoustical trapping force of spherical Mie particles by ultrasound in any position, and analyzes the numerical calculation on the two-dimensional acoustical radiation force. This article also analyzes the conditions for the acoustical trapping phenomenon, and discusses the impact of the initial position and size of the particle on the magnitude of the acoustical radiation force. Furthermore, this paper considers the ultrasonic attenuation in a particle in the case of two-dimension, studies the attenuation's effects on the acoustical trapping force, and amends the calculation to the ordinary case with attenuation.

  20. De-tabooing dying control - a grounded theory study

    National Research Council Canada - National Science Library

    Thulesius, Hans O; Scott, Helen; Helgesson, Gert; Lynöe, Niels

    2013-01-01

    ...?" What emerged was to eventually present a grounded theory of control of dying focusing specifically on how people react in relation to issues about euthanasia and physician-assisted suicide (PAS...

  1. Study on simulating strong ground motion by fractal stochastic method

    Institute of Scientific and Technical Information of China (English)

    GUO Meng-qiu; WANG Bin; XU Zhao-yong

    2005-01-01

    @@ The time history of strong ground motion can be synthesized by empirical Green's function (EGF) method.Firstly a large seismic event is discretized into a series of subevents; secondly recordings of earthquakes with proper size and spatial distribution are chosen as time history (EGF) of those subevents; finally the EGFs are summated to get the time history of ground motion caused by the large event.

  2. Ground-water-level monitoring, basin boundaries, and potentiometric surfaces of the aquifer system at Edwards Air Force Base, California, 1992

    Science.gov (United States)

    Rewis, D.L.

    1995-01-01

    A ground-water-level monitoring program was implemented at Edwards Air Force Base, California, from January through December 1992 to monitor spatial and temporal changes in poten-tiometric surfaces that largely are affected by ground-water pumping. Potentiometric-surface maps are needed to determine the correlation between declining ground- water levels and the distribution of land subsidence. The monitoring program focused on areas of the base where pumping has occurred, especially near Rogers Lake, and involved three phases of data collection: (1) well canvassing and selection, (2) geodetic surveys, and (3) monthly ground-water-level measurements. Construction and historical water- level data were compiled for 118 wells and pi-ezometers on or near the base, and monthly ground-water-level measurements were made in 82 wells and piezometers on the base. The compiled water-level data were used in conjunction with previously collected geologic data to identify three types of no-flow boundaries in the aquifer system: structural boundaries, a principal-aquifer boundary, and ground-water divides. Heads were computed from ground-water-level measurements and land-surface altitudes and then were used to map seasonal potentiometric surfaces for the principal and deep aquifers underlying the base. Pumping has created a regional depression in the potentiometric surface of the deep aquifer in the South Track, South Base, and Branch Park well-field area. A 15-foot decline in the potentiometric surface from April to September 1992 and 20- to 30-foot drawdowns in the three production wells in the South Track well field caused locally unconfined conditions in the deep aquifer.

  3. De-tabooing dying control - a grounded theory study

    Science.gov (United States)

    2013-01-01

    Background Dying is inescapable yet remains a neglected issue in modern health care. The research question in this study was “what is going on in the field of dying today?” What emerged was to eventually present a grounded theory of control of dying focusing specifically on how people react in relation to issues about euthanasia and physician-assisted suicide (PAS). Methods Classic grounded theory was used to analyze interviews with 55 laypersons and health care professionals in North America and Europe, surveys on attitudes to PAS among physicians and the Swedish general public, and scientific literature, North American discussion forum websites, and news sites. Results Open awareness of the nature and timing of a patient’s death became common in health care during the 1960s in the Western world. Open dying awareness contexts can be seen as the start of a weakening of a taboo towards controlled dying called de-tabooing. The growth of the hospice movement and palliative care, but also the legalization of euthanasia and PAS in the Benelux countries, and PAS in Montana, Oregon and Washington further represents de-tabooing dying control. An attitude positioning between the taboo of dying control and a growing taboo against questioning patient autonomy and self-determination called de-paternalizing is another aspect of de-tabooing. When confronted with a taboo, people first react emotionally based on “gut feelings” - emotional positioning. This is followed by reasoning and label wrestling using euphemisms and dysphemisms - reflective positioning. Rarely is de-tabooing unconditional but enabled by stipulated positioning as in soft laws (palliative care guidelines) and hard laws (euthanasia/PAS legislation). From a global perspective three shapes of dying control emerge. First, suboptimal palliative care in closed awareness contexts seen in Asian, Islamic and Latin cultures, called closed dying. Second, palliative care and sedation therapy, but not euthanasia

  4. De-tabooing dying control - a grounded theory study.

    Science.gov (United States)

    Thulesius, Hans O; Scott, Helen; Helgesson, Gert; Lynöe, Niels

    2013-03-13

    Dying is inescapable yet remains a neglected issue in modern health care. The research question in this study was "what is going on in the field of dying today?" What emerged was to eventually present a grounded theory of control of dying focusing specifically on how people react in relation to issues about euthanasia and physician-assisted suicide (PAS). Classic grounded theory was used to analyze interviews with 55 laypersons and health care professionals in North America and Europe, surveys on attitudes to PAS among physicians and the Swedish general public, and scientific literature, North American discussion forum websites, and news sites. Open awareness of the nature and timing of a patient's death became common in health care during the 1960s in the Western world. Open dying awareness contexts can be seen as the start of a weakening of a taboo towards controlled dying called de-tabooing. The growth of the hospice movement and palliative care, but also the legalization of euthanasia and PAS in the Benelux countries, and PAS in Montana, Oregon and Washington further represents de-tabooing dying control. An attitude positioning between the taboo of dying control and a growing taboo against questioning patient autonomy and self-determination called de-paternalizing is another aspect of de-tabooing. When confronted with a taboo, people first react emotionally based on "gut feelings" - emotional positioning. This is followed by reasoning and label wrestling using euphemisms and dysphemisms - reflective positioning. Rarely is de-tabooing unconditional but enabled by stipulated positioning as in soft laws (palliative care guidelines) and hard laws (euthanasia/PAS legislation). From a global perspective three shapes of dying control emerge. First, suboptimal palliative care in closed awareness contexts seen in Asian, Islamic and Latin cultures, called closed dying. Second, palliative care and sedation therapy, but not euthanasia or PAS, is seen in Europe and North

  5. Surface aerosol radiative forcing derived from collocated ground-based radiometric observations during PRIDE, SAFARI, and ACE-Asia.

    Science.gov (United States)

    Hansell, Richard A; Tsay, Si-Chee; Ji, Qiang; Liou, K N; Ou, Szu-Cheng

    2003-09-20

    An approach is presented to estimate the surface aerosol radiative forcing by use of collocated cloud-screened narrowband spectral and thermal-offset-corrected radiometric observations during the Puerto Rico Dust Experiment 2000, South African Fire Atmosphere Research Initiative (SAFARI) 2000, and Aerosol Characterization Experiment-Asia 2001. We show that aerosol optical depths from the Multiple-Filter Rotating Shadowband Radiometer data match closely with those from the Cimel sunphotometer data for two SAFARI-2000 dates. The observed aerosol radiative forcings were interpreted on the basis of results from the Fu-Liou radiative transfer model, and, in some cases, cross checked with satellite-derived forcing parameters. Values of the aerosol radiative forcing and forcing efficiency, which quantifies the sensitivity of the surface fluxes to the aerosol optical depth, were generated on the basis of a differential technique for all three campaigns, and their scientific significance is discussed.

  6. Academic learning for specialist nurses: a grounded theory study.

    Science.gov (United States)

    Millberg, Lena German; Berg, Linda; Brämberg, Elisabeth Björk; Nordström, Gun; Ohlén, Joakim

    2014-11-01

    The aim was to explore the major concerns of specialist nurses pertaining to academic learning during their education and initial professional career. Specialist nursing education changed in tandem with the European educational reform in 2007. At the same time, greater demands were made on the healthcare services to provide evidence-based and safe patient-care. These changes have influenced specialist nursing programmes and consequently the profession. Grounded Theory guided the study. Data were collected by means of a questionnaire with open-ended questions distributed at the end of specialist nursing programmes in 2009 and 2010. Five universities were included. Further, individual, pair and group interviews were used to collect data from 12 specialist nurses, 5-14 months after graduation. A major concern for specialist nurses was that academic learning should be "meaningful" for their professional future. The specialist nurses' "meaningful academic learning process" was characterised by an ambivalence of partly believing in and partly being hesitant about the significance of academic learning and partly receiving but also lacking support. Specialist nurses were influenced by factors in two areas: curriculum and healthcare context. They felt that the outcome of contribution to professional confidence was critical in making academic learning meaningful.

  7. The journey into fatherhood: A grounded theory study.

    Science.gov (United States)

    Sansiriphun, Nantaporn; Kantaruksa, Kannika; Klunklin, Areewan; Baosuang, Chavee; Liamtrirat, Saowanee

    2015-12-01

    The objective of this study was to explore the process of transition into fatherhood for Thai men from childbirth to the postpartum period. Forty-one first-time Thai fathers were voluntarily recruited from two hospitals in Chiang Mai, Thailand, from December 2012 to June 2013. In-depth interviews were used to collect the data, which were analyzed based on grounded theory methodology. The basic social process that emerged as the core category was termed: "the journey into fatherhood." This process was divided into three phases: labor, delivery, and family beginning. Within this process, there were various situations, challenges, and pressures, which caused many changes of mood and feelings for the first-time fathers. Throughout this process, they applied various strategies to manage their concerns and needs, in order to develop into masterly fathers. Identifying the process of the journey into fatherhood provides nurses and midwives insight into the new fathers' experiences, which will enable them to be more sensitive, respectful, and effective caregivers.

  8. Infrared remote sensing of Earth degassing - Ground study

    Directory of Open Access Journals (Sweden)

    P. Strobl

    2005-06-01

    Full Text Available Geodynamical processes e.g., volcanoes, often cause degassing at the Earth surface. The geogas emanates via mineral springs, water mofettes, or dry mofettes. It is assumed that the emerging gas influences the temperature of the spring or mofette water, respectively and the surface temperature of the soil at and around the dry gas vents. This causes a thermal anomaly in comparison to the close vicinity. Under specific conditions this effect should be extractable from remotely acquired infrared images allowing detection, mapping and monitoring of gas vents/springs within large areas and short times. This article describes preparatory investigations for which emanating Earth gas was simulated by leading compressed air into the ground and releasing it in some depth via a metal lance. The thermal effect at the surface was observed from a nearby thermovision camera in summer and winter under varying meteorological conditions. A procedure was developed to reliably identify gas release areas within the recorded thermal images of the scene. The investigations are aiming at studies to be performed later in the Western Bohemia (Czech Republic earthquake swarm region where especially CO2 of magmatic origin from European SubContinental Mantle (ESCM emanates.

  9. Multi-Level Wild Land Fire Fighting Management Support System for an Optimized Guidance of Ground and Air Forces

    Science.gov (United States)

    Almer, Alexander; Schnabel, Thomas; Perko, Roland; Raggam, Johann; Köfler, Armin; Feischl, Richard

    2016-04-01

    Climate change will lead to a dramatic increase in damage from forest fires in Europe by the end of this century. In the Mediterranean region, the average annual area affected by forest fires has quadrupled since the 1960s (WWF, 2012). The number of forest fires is also on the increase in Central and Northern Europe. The Austrian forest fire database shows a total of 584 fires for the period 2012 to 2014, while even large areas of Sweden were hit by forest fires in August 2014, which were brought under control only after two weeks of intense fire-fighting efforts supported by European civil protection modules. Based on these facts, the improvements in forest fire control are a major international issue in the quest to protect human lives and resources as well as to reduce the negative environmental impact of these fires to a minimum. Within this paper the development of a multi-functional airborne management support system within the frame of the Austrian national safety and security research programme (KIRAS) is described. The main goal of the developments is to assist crisis management tasks of civil emergency teams and armed forces in disaster management by providing multi spectral, near real-time airborne image data products. As time, flexibility and reliability as well as objective information are crucial aspects in emergency management, the used components are tailored to meet these requirements. An airborne multi-functional management support system was developed as part of the national funded project AIRWATCH, which enables real-time monitoring of natural disasters based on optical and thermal images. Airborne image acquisition, a broadband line of sight downlink and near real-time processing solutions allow the generation of an up-to-date geo-referenced situation map. Furthermore, this paper presents ongoing developments for innovative extensions and research activities designed to optimize command operations in national and international fire

  10. Pounding Effects in Simply Supported Bridges Accounting for Spatial Variability of Ground Motion: A Case Study

    Directory of Open Access Journals (Sweden)

    G. Tecchio

    2012-01-01

    Full Text Available This study carries out a parametrical analysis of the seismic response to asynchronous earthquake ground motion of a long multispan rc bridge, the Fener bridge, located on a high seismicity area in the north-east of Italy. A parametrical analysis has been performed investigating the influence of the seismic input correlation level on the structural response: a series of nonlinear time history analyses have been executed, in which the variation of the frequency content in the accelerograms at the pier bases has been described by considering the power spectral density function (PSD and the coherency function (CF. In order to include the effects due to the main nonlinear behaviours of the bridge components, a 3D finite element model has been developed, in which the pounding of decks at cap-beams, the friction of beams at bearings, and the hysteretic behaviour of piers have been accounted for. The sensitivity analysis has shown that the asynchronism of ground motion greatly influences pounding forces and deck-pier differential displacements, and these effects have to be accurately taken into account for the design and the vulnerability assessment of long multispan simply supported bridges.

  11. Brown Carbon: Results From Ground and Airborne Studies

    Science.gov (United States)

    Weber, R. J.; Forrister, H.; Liu, J.; Nenes, A.

    2015-12-01

    Brown carbon (BrC) is directly measured with high sensitivity by isolating it from black carbon in aerosol extracts and using long path wave-guide spectrophotometry. Ambient measurements by this approach show that BrC is pervasive and can be found in almost all locations, ranging from urban environments to remote continental sites and upper reaches of the free troposphere. Biomass burning appears to be the major source in many urban and rural locations, but other sources of incomplete combustion, such as vehicle emissions in urban environments also play a role. Secondary aerosols not associated with combustion sources may also contribute, but are likely of lesser importance. Studies of ambient wildfire smoke plumes show that BrC levels decrease as it ages, with a half-life of approximately 10 hours. However, a small fraction of the emitted BrC is stable and may account for much of the BrC observed throughout the atmosphere due to widely dispersed and ubiquitous smoke. A radiative transfer model indicates that this background BrC reduced US continental TOA forcing by 20 percent. Human health studies point to similar chemical components linked to BrC (i.e., HULIS), of this same ubiquitous smoke, as a significant source of adverse cardiorespiratory effects. This talk will summarize findings on BrC sources, transformations and estimates of environmental effects based on bulk measurements.

  12. Student nurse socialisation in compassionate practice: a Grounded Theory study.

    Science.gov (United States)

    Curtis, Katherine; Horton, Khim; Smith, Pam

    2012-10-01

    Compassionate practice is expected of Registered Nurses (RNs) around the world while at the same time remaining a contested concept. Nevertheless, student nurses are expected to enact compassionate practice in order to become RNs. In order for this to happen they require professional socialisation within environments where compassion can flourish. However, there is concern that student nurse socialisation is not enabling compassion to flourish and be maintained upon professional qualification. In order to investigate this further, a glaserian Grounded Theory study was undertaken using in-depth, digitally recorded interviews with student nurses (n=19) at a university in the north of England during 2009 and 2010. Interviews were also undertaken with their nurse teachers (n=5) and data from National Health Service (NHS) patients (n=72,000) and staff (n=290,000) surveys were used to build a contextual picture of the student experience. Within the selected findings presented, analysis of the data indicates that students aspire to the professional ideal of compassionate practice although they have concerns about how compassionate practice might fit within the RN role because of constraints on RN practice. Students feel vulnerable to dissonance between professional ideals and practice reality. They experience uncertainty about their future role and about opportunities to engage in compassionate practice. Students manage their vulnerability and uncertainty by balancing between an intention to uphold professional ideals and challenge constraints, and a realisation they might need to adapt their ideals and conform to constraints. This study demonstrates that socialisation in compassionate practice is compromised by dissonance between professional idealism and practice realism. Realignment between the reality of practice and professional ideals, and fostering student resilience, are required if students are to be successfully socialised in compassionate practice and enabled

  13. Atomic force microscopy studies of human rhinovirus topology and molecular forces.

    Science.gov (United States)

    Kienberger, Ferry; Zhu, Rong; Rankl, Christian; Gruber, Hermann J; Blaas, Dieter; Hinterdorfer, Peter

    2010-01-01

    Dynamic force microscopy (DFM) allows for imaging of the structure and assessment of the function of biological specimens in their physiological environment. In DFM, the cantilever is oscillated at a given frequency and touches the sample only at the end of its downward movement. Accordingly, the problem of lateral forces displacing or even destroying biomolecules is virtually inexistent as the contact time and friction forces are greatly reduced. Here, we describe the use of DFM in studies of human rhinovirus serotype 2 (HRV2). The capsid of HRV2 was reproducibly imaged without any displacement of the virus. Release of the genomic RNA from the virions was initiated by exposure to low-pH buffer and snapshots of the extrusion process were obtained. DFM of the single-stranded RNA genome of an HRV showed loops protruding from a condensed RNA core, 20-50 nm in height. The mechanical rigidity of the RNA was determined by single molecule pulling experiments. From fitting RNA stretching curves to the worm-like-chain (WLC) model a persistence length of 1.0+/-0.17 nm was obtained.

  14. A method to study precision grip control in viscoelastic force fields using a robotic gripper.

    Science.gov (United States)

    Lambercy, Olivier; Metzger, Jean-Claude; Santello, Marco; Gassert, Roger

    2015-01-01

    Instrumented objects and multipurpose haptic displays have commonly been used to investigate sensorimotor control of grasping and manipulation. A major limitation of these devices, however, is the extent to which the experimenter can vary the interaction dynamics to fully probe sensorimotor control mechanisms. We propose a novel method to study precision grip control using a grounded robotic gripper with two moving, mechanically coupled finger pads instrumented with force sensors. The device is capable of stably rendering virtual mechanical properties with a wide dynamic range of achievable impedances. Eight viscoelastic force fields with different combinations of stiffness and damping parameters were implemented, and tested on eight healthy subjects performing 30 consecutive repetitions of a grasp, hold, and release task with time and position constraints. Rates of thumb and finger force were found to be highly correlated (r>0.9) during grasping, revealing that, despite the mechanical coupling of the two finger pads, subjects performed grasping movements in a physiological fashion. Subjects quickly adapted to the virtual dynamics (within seven trials), but, depending on the presented force field condition, used different control strategies to correctly perform the task. The proof of principle presented in this paper underscores the potential of such a one-degree-of-freedom robotic gripper to study neural control of grasping, and to provide novel insights on sensorimotor control mechanisms.

  15. [Environmental investigation of ground water contamination at Wright-Patterson Air Force Base, Ohio]. Volume 3, Appendix A, Draft standard operating procedures and elements: Sampling and Analysis Plan (SAP): Phase 1, Task 4, Field Investigation, Draft

    Energy Technology Data Exchange (ETDEWEB)

    1991-10-01

    This report presents information concerning field procedures employed during the monitoring, well construction, well purging, sampling, and well logging at the Wright-Patterson Air Force Base. Activities were conducted in an effort to evaluate ground water contamination.

  16. Optical tweezers force measurements to study parasites chemotaxis

    Science.gov (United States)

    de Thomaz, A. A.; Pozzo, L. Y.; Fontes, A.; Almeida, D. B.; Stahl, C. V.; Santos-Mallet, J. R.; Gomes, S. A. O.; Feder, D.; Ayres, D. C.; Giorgio, S.; Cesar, C. L.

    2009-07-01

    In this work, we propose a methodology to study microorganisms chemotaxis in real time using an Optical Tweezers system. Optical Tweezers allowed real time measurements of the force vectors, strength and direction, of living parasites under chemical or other kinds of gradients. This seems to be the ideal tool to perform observations of taxis response of cells and microorganisms with high sensitivity to capture instantaneous responses to a given stimulus. Forces involved in the movement of unicellular parasites are very small, in the femto-pico-Newton range, about the same order of magnitude of the forces generated in an Optical Tweezers. We applied this methodology to investigate the Leishmania amazonensis (L. amazonensis) and Trypanossoma cruzi (T. cruzi) under distinct situations.

  17. Minority nursing student success: A grounded theory case study

    Science.gov (United States)

    Mister, Brenda J.

    There has been a dramatic increase in the nation's racial and ethnic minority populations over recent years. This increase is placing a higher demand on the health care industry to provide culturally competent care to these diverse populations. This challenge is met with yet another problem as the nation faces a critical shortage of nurses, particularly minority nurses. This shortage is only expected to worsen over the next several years. As schools of nursing across the country are being asked to increase the number of nursing program graduates, specifically minorities, they are confronted with a double edged sword as retention rates are decreasing, and attrition rates are increasing. This is particularly troublesome when many racial and ethnic minority nursing students do not graduate. This qualitative study was implemented to assess and understand the perceived educational experiences of racial and ethnic minority nursing students enrolled in a rural community college nursing program on the Eastern Shore of Maryland. Eight voluntary nursing students who identified themselves as either a racial or ethnic minority participated in the study. Data were collected by: individual audio-taped interview sessions; audio-taped focus group sessions; and documentation of field notes. Participants also provided demographic information and were asked to provide a brief written response to a scenario regarding increasing the recruitment and retention rates of minority nursing students. All data were analyzed utilizing the constant comparative method. Results of the study revealed six different themes: personal support systems and peer relationships; college services and academic resources; faculty support; cultural understanding versus cultural insensitivity; personal attributes of self-efficacy/advice for future nursing students; and suggestions for college and nursing program improvement. After the major themes were examined one central theme, a grounded theory, was born. The

  18. An RNA toolbox for single-molecule force spectroscopy studies

    NARCIS (Netherlands)

    Vilfan, I.D.; Kamping, W.; Van den Hout, M.; Candelli, A.; Hage, S.; Dekker, N.H.

    2007-01-01

    Precise, controllable single-molecule force spectroscopy studies of RNA and RNA-dependent processes have recently shed new light on the dynamics and pathways of RNA folding and RNAenzyme interactions. A crucial component of this research is the design and assembly of an appropriate RNA construct. Su

  19. Student Understanding of Intermolecular Forces: A Multimodal Study

    Science.gov (United States)

    Cooper, Melanie M.; Williams, Leah C.; Underwood, Sonia M.

    2015-01-01

    The ability to use representations of molecular structure to predict the macroscopic properties of a substance is central to the development of a robust understanding of chemistry. Intermolecular forces (IMFs) play an important role in this process because they provide a mechanism for how and why molecules interact. In this study, we investigate…

  20. [Environmental investigation of ground water contamination at Wright- Patterson Air Force Base, Ohio]. Volume 4, Health and Safety Plan (HSP); Phase 1, Task 4 Field Investigation report: Draft

    Energy Technology Data Exchange (ETDEWEB)

    1991-10-01

    This Health and Safety Plan (HSP) was developed for the Environmental Investigation of Ground-water Contamination Investigation at Wright-Patterson Air Force Base near Dayton, Ohio, based on the projected scope of work for the Phase 1, Task 4 Field Investigation. The HSP describes hazards that may be encountered during the investigation, assesses the hazards, and indicates what type of personal protective equipment is to be used for each task performed. The HSP also addresses the medical monitoring program, decontamination procedures, air monitoring, training, site control, accident prevention, and emergency response.

  1. Study on distribution rule of sliding pushing force and remnant resistant sliding force acting on anti-sliding pile

    Institute of Scientific and Technical Information of China (English)

    Qingyang YU; Lei NIE

    2006-01-01

    Anti-slide pile is one of the important methods to administer landslide geological disaster because of its advantages. It plays important role in administering landslide. It is a premise of reasonable economy and technological advance to know the distribution rule and feature of the force between anti-sliding pile and surrounding rock. To determine the sliding force and remnant resistant sliding force, according to need of study, this paper sets up the geological model and mechanics model in term of a typical landslide, and analyzes the effect rule of sliding body distortion, strength and gravity to the pushing force and remnant resistant sliding force by use of the numerical model. The distribution rule of pushing force and remnant resistant sliding force of the type of landslide is given.

  2. Objective Lightning Forecasting at Kennedy Space Center/Cape Canaveral Air Force Station using Cloud-to-Ground Lightning Surveillance System Data

    Science.gov (United States)

    Lambert, Winifred; Wheeler, Mark

    2004-01-01

    The 45th Weather Squadron (45 WS) forecasters at Cape Canaveral Air Force Station (CCAFS) in Florida include a probability of thunderstorm occurrence in their daily morning briefings. This information is used by personnel involved in determining the possibility of violating Launch Commit Criteria, evaluating Flight Rules for the Space Shuttle, and daily planning for ground operation activities on Kennedy Space Center (KSC)/CCAFS. Much of the current lightning probability forecast is based on a subjective analysis of model and observational data. The forecasters requested that a lightning probability forecast tool based on statistical analysis of historical warm-season (May - September) data be developed in order to increase the objectivity of the daily thunderstorm probability forecast. The tool is a set of statistical lightning forecast equations that provide a lightning occurrence probability for the day by 1100 UTC (0700 EDT) during the warm season. This study used 15 years (1989-2003) of warm season data to develop the objective forecast equations. The local CCAFS 1000 UTC sounding was used to calculate stability parameters for equation predictors. The Cloud-to-Ground Lightning Surveillance System (CGLSS) data were used to determine lightning occurrence for each day. The CGLSS data have been found to be more reliable indicators of lightning in the area than surface observations through local informal analyses. This work was based on the results from two earlier research projects. Everitt (1999) used surface observations and rawinsonde data to develop logistic regression equations that forecast the daily thunderstorm probability at CCAFS. The Everitt (1999) equations showed an improvement in skill over the Neumann-Pfeffer thunderstorm index (Neumann 1971), which uses multiple linear regression, and also persistence and climatology forecasts. Lericos et al. (2002) developed lightning distributions over the Florida peninsula based on specific flow regimes. The

  3. [Biomechanical study on dento-alveolar arch forces].

    Science.gov (United States)

    Onu, Brînduşa; Burlui, V

    2009-01-01

    This study has two major objectives. The first one is to draw attention in an original device especially conceived and designed to measure bite force; the second purpose of the study is represented by proper measurements of individual bite force during bilateral clenching for two lots of patients using this device and comparing the outcomes to those of other similar studies, in order to prove its practical utility. 62 young (20-35 years of age) healthy patients were tested: 35 fully dentured subjects in control group and 27 subjects with various single unit treated edentation, in test group. The two potentiometers from the lateral side of the device are connected to a computer which would measure, register and interpret the outcomes during three different sessions of clenching for each patient. Measured values showed that the mean maximum bilateral bite force in patients with no edentation was, in all cases, higher than in patients with single unit treated edentation for all three sessions. Because the device allows simultaneous bilateral registration of the bite force, during the same session, it is obvious that it can measure also the asymmetry between left and right dental hemi-arches. Therefore, in control group, mean values found in left side were higher (369.36N - 399.75N) than right side (352.18N - 392.15N); an opposite situation was found in test group: higher values were found in right side (313.75N - 329.43N) comparing to left side (310.54N -321.53N). The device proved to be usefull not only for measuring bite force in one region of dental arches, but it is designed to simultaneous register parameters from various regions; the values obtained in this study are similar to those reported by others authors who used more sophisticated devices, so that this simple device proves its usefulness.

  4. Study on influence of ground settlement in bored metro tunnel

    Institute of Scientific and Technical Information of China (English)

    FANG Jiang-hua; ZHANG Zhi-hong

    2006-01-01

    At present the bored construction method is one of the main construction methods of metro and tunnel construction in China. The empirical estimated formulas of tunnel ground surface settlement using the bored construction method were obtained,combining the mechanical stimulant calculated result of tunnel model of different embedded depth, different cross section and different construction method and the actual measurement data of Beijing metro construction. According to the regressed analysis of calculated data, the calculated equations of ground surface settlement value and settlement range of tunnel section under the condition of different embedded depth, different cross section and different construction method were gained. Among them there are some empirical formulas can apply to the construction design ofmetro tunnel directly.

  5. Wind tunnel studies of gas dispersion from ground level source

    Directory of Open Access Journals (Sweden)

    Michálek Petr

    2015-01-01

    Full Text Available Measurements of gas dispersion from ground source were performed in a boundary layer wind tunnel in VZLU Prague. The measurements include non-buoyant gas dispersion behind a ground level source on a flat plane, on a simple rectangular building model and behind a model hill and rectangular barrier. These measurements will serve for verification of a new gas dispersion software being developed in VZLU. The dispersion model is intended for use by firemen and ambulance services in the case of an accident for immediate estimation of the area with dangerous gas concentration. The dispersion model will use precalculated results for chosen areas in the Czech Republic with industrial plants and residential building in the neighborhood. The size of contaminated area will be estimated using actual meteorological situation, i.e. wind speed and direction etc. and precalculated data of flow and dispersion in the chosen location.

  6. Wind tunnel studies of gas dispersion from ground level source

    Science.gov (United States)

    Michálek, Petr; Zacho, David

    2015-05-01

    Measurements of gas dispersion from ground source were performed in a boundary layer wind tunnel in VZLU Prague. The measurements include non-buoyant gas dispersion behind a ground level source on a flat plane, on a simple rectangular building model and behind a model hill and rectangular barrier. These measurements will serve for verification of a new gas dispersion software being developed in VZLU. The dispersion model is intended for use by firemen and ambulance services in the case of an accident for immediate estimation of the area with dangerous gas concentration. The dispersion model will use precalculated results for chosen areas in the Czech Republic with industrial plants and residential building in the neighborhood. The size of contaminated area will be estimated using actual meteorological situation, i.e. wind speed and direction etc. and precalculated data of flow and dispersion in the chosen location.

  7. Spectral invariance hypothesis study of polarized reflectance with Ground-based Multiangle SpectroPolarimetric Imager (GroundMSPI)

    Science.gov (United States)

    Bradley, Christine L.; Kupinski, Meredith; Diner, David J.; Xu, Feng; Chipman, Russell A.

    2015-09-01

    Many models used to represent the boundary condition for the separation of atmospheric scattering from the surface reflectance in polarized remote sensing measurements assume that the polarized surface reflectance is spectrally neutral. The Spectral Invariance Hypothesis asserts that the magnitude and shape of the polarized bidirectional reflectance factor (pBRF) is equal for all wavelengths. In order to test this hypothesis, JPL's Ground-based Multiangle SpectroPolarimetric Imager (GroundMSPI) is used to measure polarization information of different outdoor surface types. GroundMSPI measures the linear polarization Stokes parameters (I, Q, U), at three wavelengths, 470 nm, 660 nm, and 865 nm. The camera is mounted on a two-axis gimbal to accurately select the view azimuth and elevation directions. On clear sky days we acquired day-long scans of scenes that contain various surface types such as grass, dirt, cement, brick, and asphalt and placed a Spectralon panel in the camera field of view to provide a reflectance reference. Over the course of each day, changing solar position in the sky provides a large range of scattering angles for this study. The polarized bidirectional reflectance factor (pBRF) is measured for the three wavelengths and the best fit slope of the spectral correlation is reported. This work reports the range of best fit slopes measured for five region types.

  8. Effect of ground motion from nuclear excavation: interim canal studies

    Energy Technology Data Exchange (ETDEWEB)

    King, C. Y.; Nadolski, M. E.

    1969-09-01

    The effect of ground motion due to nuclear excavation of a sea-level canal at two alternative routes, 17A and 25E, are discussed from the aspects of motion prediction and structural response. The importance of the high-rise building problem is stressed because of its complexity. Several damage criteria are summarized for advance planning of excavation and operation. The 1964 shot schedule and the latest revised schedule are included for comparison.

  9. Regression relationships of landing height with ground reaction forces, knee flexion angles, angular velocities and joint powers during double-leg landing.

    Science.gov (United States)

    Yeow, C H; Lee, Peter V S; Goh, James C H

    2009-10-01

    Ground reaction forces (GRF), knee flexion angles, angular velocities and joint powers are unknown at large landing heights, which are infeasible for laboratory testing. However, this information is important for understanding lower extremity injury mechanisms. We sought to determine regression relationships of landing height with these parameters during landing so as to facilitate estimation of these parameters at large landing heights. Five healthy male subjects performed landing tasks from heights of 0.15-1.05 m onto a force-plate. Motion capture system was used to obtain knee flexion angles during landing via passive markers placed on the lower body. An iterative regression model, involving simple linear/exponential/natural logarithmic functions, was used to fit regression equations to experimental data. Peak GRF followed an exponential regression relationship (R(2)=0.90-0.99, p<0.001; power=0.987-0.998). Peak GRF slope and impulse also had an exponential relationship (R(2)=0.90-0.96, p<0.001; power=0.980-0.997 and R(2)=0.90-0.99, p<0.001; power=0.990-1.000 respectively) with landing height. Knee flexion angle at initial contact and at peak GRF had an inverse-exponential regression relationship (R(2)=0.81-0.99, p<0.001-p=0.006; power=0.834-0.978 and R(2)=0.84-0.97, p<0.001-p=0.004; power=0.873-0.999 respectively). There was also an inverse-exponential relationship between peak knee flexion angular velocity and landing height (R(2)=0.86-0.96, p<0.001; power=0.935-0.994). Peak knee joint power demonstrated a substantial linear relationship (R(2)=0.98-1.00, p<0.001; power=0.990-1.000). The parameters analyzed in this study are highly dependent on landing height. The exponential increase in peak GRF parameters and the relatively slower increase in knee flexion angles, angular velocities and joint power may synergistically lead to an exacerbated lower extremity injury risk at large landing heights.

  10. Studies on deposition, adhesion and resuspension of radioactive substances on the ground surface and ground cover

    Energy Technology Data Exchange (ETDEWEB)

    Kurita, Susumu; Kurihara, Kazuo [Meteorological Research Inst., Tsukuba, Ibaraki (Japan)

    1999-03-01

    After the Chernobyl` nuclear power plant accident, resuspension of radioactive nuclei into the atmosphere is recognized as the one of the important processes that must be considered in the estimation of inhalation doses to humans. In this study, resuspensions of particles from soil and grass have been studied. The resuspension of particles from bare soil was modelized by using Shao`s method. The resuspension of particles from grass was studied by a wind tunnel and a field experiment. Dependencies of the resuspension rate on time and on friction velocity were obtained clearly. And it was also found that the other meteorological parameters, such as temperature, relative humidity, solar radiation and condensation, affected the resuspension rate in the field. (author)

  11. Shifting Ground(s): Surveying the contested terrain of LGBT studies and queer theory.

    Science.gov (United States)

    Lovaas, Karen E; Elia, John P; Yep, Gust A

    2006-01-01

    While queer theory initially grew out of lesbian, gay, bisexual, and transgender (LGBT) studies, there are numerous points of contestation between these two approaches, originating mostly from their disparate positions on (sexual) identity politics. To describe, analyze, and contextualize this contested terrain, we begin this piece by providing some historical notes on LGBT studies and queer theory. Next, we turn to an explication of some enduring tensions to identify the criticisms generated by LGBT scholars toward queer theory approaches and vice versa. What follows is our rationale for producing LGBT Studies and Queer Theory: New Conflicts, Collaborations, and Contested Terrain. In this section we discuss how this project originated and the specific objectives we hope this volume will meet. The contributions of the individual articles in this volume are identified and summarized next. Finally, in the context of LGBT studies' and queer theory's similar qualities and points of difference, we offer ideas for potential directions of scholarship in the future that would explore three major areas: identity and difference; community and community organizing; and political engagement and social change.

  12. Numerical studies of a plasma diode with external forcing

    Science.gov (United States)

    Rekaa, V. L.; Pécseli, H. L.; Trulsen, J. K.

    2012-08-01

    With reference to laboratory Q-machine studies we analyze the dynamics of a plasma diode under external forcing. Assuming a strong axial magnetic field, the problem is analyzed in one spatial dimension by a particle-in-cell code. The cathode is assumed to be operated in electron rich conditions, supplying an abundance of electrons. We compare different forcing schemes with the results obtained by solving the van der Pol equation. In one method of forcing we apply an oscillation in addition to the DC end plate bias and consider both amplitude and frequency variations. An alternative method of perturbation consists of modelling an absorbing grid at some internal position. Also in this case we can have a constant frequency with varying amplitude or alternatively an oscillation with chirped frequency but constant amplitude. We find that the overall features of the forced van der Pol equation are recovered, but the details in the plasma response need more attention to the harmonic responses, requiring extensions of the model equation. The analysis is extended by introducing collisional effects, where we emphasize charge exchange collisions of ions, since these processes usually have the largest cross sections and give significant modifications of the diode performance. In particular we find a reduction in oscillator frequency, although a linear scaling of the oscillation time with the system length remains also in this case.

  13. Forces affecting orbital floor reconstruction materials--a cadaver study.

    Science.gov (United States)

    Birkenfeld, Falk; Steiner, Martin; Kern, Matthias; Wiltfang, Jörg; Möller, Björn; Lucius, Ralph; Becker, Stephan Thomas

    2013-01-01

    The objectives of this study were: (i) to evaluate the applied force and the displacement of the orbital contents after orbital floor reconstruction using artificially aged reconstruction materials in fresh frozen human heads and (ii) to analyze the puncture strength of the materials. Six fresh frozen human heads were used, and orbital floor defects in the right and left orbit were created by 3.0 J direct impacts on the globe and infraorbital rim. The orbital floor defect sizes and displacements were evaluated after a Le-Fort-I osteotomy. The orbital floor defect sizes were 208.3(SD, 33.4) mm(2) for the globe impacts and 221.8(SD, 53.1) mm(2) for the infraorbital impacts. The forces on the incorporated materials were approximately 0.003 N and 0.03 N for the PDS-foil and collagen membrane, respectively. The displacements of the materials were +0.9 mm and +0.7 mm for the PDS-foil and collagen membrane, respectively. The puncture strengths of the PDS-foil and collagen membrane decreased from approximately 70 N and 12 N at week 1 to approximately 5 N and 1.5 N at week 8 of artificial aging. The force applied to the orbital content is minimal, and the puncture strengths of the artificially aged materials are more than sufficient for the measured forces. Copyright © 2012 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

  14. Biosensors for EVA: Improved Instrumentation for Ground-based Studies

    Science.gov (United States)

    Soller, B.; Ellerby, G.; Zou, F.; Scott, P.; Jin, C.; Lee, S. M. C.; Coates, J.

    2010-01-01

    During lunar excursions in the EVA suit, real-time measurement of metabolic rate is required to manage consumables and guide activities to ensure safe return to the base. Metabolic rate, or oxygen consumption (VO2), is normally measured from pulmonary parameters but cannot be determined with standard techniques in the oxygen-rich environment of a spacesuit. Our group has developed novel near infrared spectroscopic (NIRS) methods to calculate muscle oxygen saturation (SmO 2), hematocrit, and pH, and we recently demonstrated that we can use our NIRS sensor to measure VO 2 on the leg during cycling. Our NSBRI project has 4 objectives: (1) increase the accuracy of the metabolic rate calculation through improved prediction of stroke volume; (2) investigate the relative contributions of calf and thigh oxygen consumption to metabolic rate calculation for walking and running; (3) demonstrate that the NIRS-based noninvasive metabolic rate methodology is sensitive enough to detect decrement in VO 2 in a space analog; and (4) improve instrumentation to allow testing within a spacesuit. Over the past year we have made progress on all four objectives, but the most significant progress was made in improving the instrumentation. The NIRS system currently in use at JSC is based on fiber optics technology. Optical fiber bundles are used to deliver light from a light source in the monitor to the patient, and light reflected back from the patient s muscle to the monitor for spectroscopic analysis. The fiber optic cables are large and fragile, and there is no way to get them in and out of the test spacesuit used for ground-based studies. With complimentary funding from the US Army, we undertook a complete redesign of the sensor and control electronics to build a novel system small enough to be used within the spacesuit and portable enough to be used by a combat medic. In the new system the filament lamp used in the fiber optic system was replaced with a novel broadband near infrared

  15. Biosensors for EVA: Improved Instrumentation for Ground-based Studies

    Science.gov (United States)

    Soller, B.; Ellerby, G.; Zou, F.; Scott, P.; Jin, C.; Lee, S. M. C.; Coates, J.

    2010-01-01

    During lunar excursions in the EVA suit, real-time measurement of metabolic rate is required to manage consumables and guide activities to ensure safe return to the base. Metabolic rate, or oxygen consumption (VO2), is normally measured from pulmonary parameters but cannot be determined with standard techniques in the oxygen-rich environment of a spacesuit. Our group has developed novel near infrared spectroscopic (NIRS) methods to calculate muscle oxygen saturation (SmO 2), hematocrit, and pH, and we recently demonstrated that we can use our NIRS sensor to measure VO 2 on the leg during cycling. Our NSBRI project has 4 objectives: (1) increase the accuracy of the metabolic rate calculation through improved prediction of stroke volume; (2) investigate the relative contributions of calf and thigh oxygen consumption to metabolic rate calculation for walking and running; (3) demonstrate that the NIRS-based noninvasive metabolic rate methodology is sensitive enough to detect decrement in VO 2 in a space analog; and (4) improve instrumentation to allow testing within a spacesuit. Over the past year we have made progress on all four objectives, but the most significant progress was made in improving the instrumentation. The NIRS system currently in use at JSC is based on fiber optics technology. Optical fiber bundles are used to deliver light from a light source in the monitor to the patient, and light reflected back from the patient s muscle to the monitor for spectroscopic analysis. The fiber optic cables are large and fragile, and there is no way to get them in and out of the test spacesuit used for ground-based studies. With complimentary funding from the US Army, we undertook a complete redesign of the sensor and control electronics to build a novel system small enough to be used within the spacesuit and portable enough to be used by a combat medic. In the new system the filament lamp used in the fiber optic system was replaced with a novel broadband near infrared

  16. [Environmental investigation of ground water contamination at Wright-Patterson Air Force Base, Ohio]. Volume 3, Sampling and analysis plan (SAP): Phase 1, Task 4, Field Investigation: Draft

    Energy Technology Data Exchange (ETDEWEB)

    1991-10-01

    In April 1990, Wright-Patterson Air Force Base (WPAFB), initiated an investigation to evaluate a potential Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) removal action to prevent, to the extent practicable, the offsite migration of contaminated ground water from WPAFB. WPAFB retained the services of the Environmental Management Operations (EMO) and its principle subcontractor, International Technology Corporation (IT) to complete Phase 1 of the environmental investigation of ground-water contamination at WPAFB. Phase 1 of the investigation involves the short-term evaluation and potential design for a program to remove ground-water contamination that appears to be migrating across the western boundary of Area C, and across the northern boundary of Area B along Springfield Pike. Primarily, Task 4 of Phase 1 focuses on collection of information at the Area C and Springfield Pike boundaries of WPAFB. This Sampling and Analysis Plan (SAP) has been prepared to assist in completion of the Task 4 field investigation and is comprised of the Quality Assurance Project Plan (QAPP) and the Field Sampling Plan (FSP).

  17. Study of ground handling characteristics of a maritime patrol airship

    Science.gov (United States)

    1981-01-01

    Mooring concepts appropriate for maritime patrol airship (MPA) vehicles are investigated. The evolution of ground handling systems and procedures for all airship types is reviewed to ensure that appropriate consideration is given to past experiences. A tri-rotor maritime patrol airship is identified and described. Wind loads on a moored airship and the effects of these loads on vehicle design are analyzed. Several mooring concepts are assessed with respect to the airship design, wind loads, and mooring site considerations. Basing requirements and applicability of expeditionary mooring also are addressed.

  18. Studying Convective Events Over Southern Arizona by Using Ground GPS Receivers and Cloud to Ground Lightning

    Science.gov (United States)

    Orduño, A. M.; Sosa, C. M.; Jacobo, R. A.

    2013-05-01

    Over the last decades, Global Position System (GPS) satellites have been used for in various fields of the Earth Sciences. In particular, "GPS Meteorology" was born in the attempt to retrieve water vapor, specifically column-integrated water vapor or, precipitable water vapor (PWV), that results from the noise induced by the atmosphere in the GPS signal. Monitoring PWV with GPS is relatively inexpensive, works under all weather conditions, and has a high time resolution which complements traditional techniques such as radiosondes and satellite-based retrievals. The North American Monsoon (NAM) is a seasonal system that affects the southwestern of United States and northwestern Mexico. Atmospheric Water Vapor is transported from the Gulf of California, Pacific Ocean and the Gulf of Mexico to the continental areas and this contribute to the genesis of convective systems that develop over this region. In many cases, these systems are characterized by relatively short lifetimes, a great amount of precipitation accompanied with lightning making it difficult to study with radiosondes, given their limited time resolution (operationally twice a day). On the other hand, GOES satellite has better time resolution (one hour), but does not provide water vapor in cloudy conditions, precisely when the data are needed. This makes GPS a great tool to study deep atmospheric convection over during the NAM. During the monsoon season 2002 and 2003, we noted that local GPS and the radiosondes launched in Tucson, Arizona showed, for some cases, a significant discrepancy in their PWV estimation. In determining the causes of these discrepancies we discovered that the GPS was detecting convective events in its vicinity that the radiosondes could not detect, a strength that had not considered before. Convective activity in Southern Arizona often produces gust fronts that result in dramatic changes of temperature and humidity. These gust fronts also generate a shift in wind direction and

  19. Theoretical Study on the Capillary Force between an Atomic Force Microscope Tip and a Nanoparticle

    Institute of Scientific and Technical Information of China (English)

    LI Zhao-Xia; ZHANG Li-Juan; YI Hou-Hui; FANG Hai-Ping

    2007-01-01

    @@ Considering that capillary force is one of the most important forces between nanoparticles and atomic force microscope (AFM) tips in ambient atmosphere, we develop an analytic approach on the capillary force between an AFM tip and a nanoparticle. The results show that the capillary forces are considerably affected by the geometry of the AFM tip, the humidity of the environment, the vertical distance between the AFM tip and the nanoparticle, as well as the contact angles of the meniscus with an AFM tip and a nanoparticle. It is found that the sharper the AFM tip, the smaller the capillary force. The analyses and results are expected to be helpful for the quantitative imaging and manipulating of nanoparticles by AFMs.

  20. The Adriatic response to the bora forcing. A numerical study

    Energy Technology Data Exchange (ETDEWEB)

    Rachev, N. [Sofia Univ., Sofia (Bulgaria). Dept. of Meteorology and Geophysics; Purini, R. [Consiglio Nazionale delle Ricerche, Istituto Talassografico, Trieste (Italy)

    2001-04-01

    This paper deals with the bora wind effect on the Adriatic Sea circulation as simulated by a 3-D numerical code (the DieCAST model). The main result of this forcing is the formation of intense upwelling along the eastern coast in agreement with previous theoretical studies and observations. Different numerical experiments are discussed for various boundary and initial conditions to evaluate their influence on both circulation and upwelling patterns.

  1. Evapo-transpiration, role of aerosol radiative forcing: a study over a dense canopy

    Science.gov (United States)

    Bhanage, VInayak; Latha, R.; Murthy, B. S.

    2016-05-01

    Current study uses Satellite and Reanalysis data to quantify the effect of aerosol on ET at various space and time scales. All the data are obtained for the period June 2008 to May 2009 over Dibrugarh district, Assam, Indi a where NDVI has limited change of through the year. Monthly Evapo-Transpiration (ET, cumulative), Normalized Difference Vegetation Index (NDVI) and Aerosol Optical Depth (AOD) are retrieved from satellite images of Terra-MODIS. The AOD data are evaluated against in-situ observations. Maximum values of AOD are observed in the pre-monsoon season while minimum AOD values are perceived in October and November. Aerosol Radiative Forcing (ARF) is calculated by using the MERRA data sets of `clean-clear radiation' and `clear-radiation' at surface over the study area. Maximum aerosol radiative forcing is observed during the pre-monsoon season; this is in tune with ground observations. Strong positive correlation (r=0.75) between ET and NDVI is observed and it is found that the dense vegetative surfaces exhibit higher rate of evapo-transpiration. A strong positive correlation (r= -0.85) between ARF at surface and AOD is observed with radiative forcing efficiency of 35 W/m2. A statistical regression equation of ET a s a function of NDVI and AOD i.e. ET = 0.25 + (-84.27) * AOD + (131.51) * NDVI, is obtained that shows a correlation of 0.824.

  2. Adhesion, unfolding forces, and molecular elasticity of fibronectin coatings: An atomic force microscopy study.

    Science.gov (United States)

    Sumarokova, Maria; Iturri, Jagoba; Toca-Herrera, José L

    2017-10-07

    Fibronectin is an extracellular matrix protein that is involved in cell adhesion, growth, migration, differentiation, and wound healing. Fibronectin coatings are currently used in many laboratories for biomedical and biotechnology purposes. In this study we have investigated the adhesion and mechanical properties of fibronectin coatings. The coatings were also used to study the role of the residence time and the influence of the loading rate in nonspecific interactions. The results showed that the adhesion force between silica and fibronectin increased with loading rate delivering similar values for residence times of 1 and 2 s. Further analysis indicated that the distance to the transition state was about 0.5 nm. Moreover, the adhesion force did not vary with the loading rate for contact time of 0 s. The unfolding of fibronectin domains also depended of the Dwell time (no unfolding events were observed for zero residence time). Applied loads of 2 nN were able to stretch the fibronectin layer up to 200 nm and to unfold the three fibronectin domains, which were similar for a Dwell time of 1 and 2 s. However, the unfolding length increased with loading rate: below 2.5 µm s(-1) the obtained lengths matched the value of FN I (13.5 nm), while for higher speeds the measured values corresponded to the lengths of FN II (18 nm) and FN III (27 nm). This investigation has answered and opened new questions about the mechanical stability and function of fibronectin coatings. The results have also raised theoretical questions about the difference between specific and nonspecific interactions to be addressed in future work. © 2017 Wiley Periodicals, Inc.

  3. Experimental Study of Ground Effect on Three-Dimensional Insect-Like Flapping Motion

    Science.gov (United States)

    Zhang, Xiaohu; Lua, Kim Boon; Chang, Rong; Lim, Tee Tai; Yeo, Khoon Seng

    2014-11-01

    This paper focuses on an experimental investigation aimed at evaluating the aerodynamics force characteristics of three-dimensional (3D) insect-like flapping motion in the vicinity of ground. The purpose is to establish whether flapping wing insects can derive aerodynamic benefit from ground effect similar to that experienced by a fixed wing aircraft. To evaluate this, force measurements were conducted in a large water tank using a 3D flapping mechanism capable of executing various insect flapping motions. Here, we focus on three types of flapping motions, namely simple harmonic flapping motion, hawkmoth-like hovering motion and fruitfly-like hovering motion, and two types of wing planforms (i.e. hawkmoth-like wing and fruitfly-like wing). Results show that hawkmoth-like wing executing simple harmonic flapping motion produces average lift to drag ratio (\\bar C\\bar L/\\bar C\\bar D) similar to that of fruitfly wing executing the same motion. In both cases, they are relatively independent of the wing distance from the ground. On the other hand, a hawkmoth wing executing hawkmoth flapping motion produces (\\bar C\\bar L/\\bar C\\bar D) characteristic different from that of fruitfly wing executing fruitfly motion. While the (\\bar C\\bar L/\\bar C\\bar D) value of the former is a function of the wing distance from the ground, the latter is minimally affected by ground effect. Unlike fixed wing aerodynamics, all the flapping wing cases considered here do not show a monotonic increase in (\\bar C\\bar L/\\bar C\\bar D) with decreasing wing distance from the ground.

  4. Fundamental study of phosphor separation by controlling magnetic force

    Energy Technology Data Exchange (ETDEWEB)

    Wada, Kohei, E-mail: kohei@qb.see.eng.osaka-u.ac.jp; Mishima, Fumihito; Akiyama, Yoko, E-mail: yoko-ak@qb.see.eng.osaka-u.ac.jp; Nishijima, Shigehiro

    2013-11-15

    Highlights: •We tried to separate the phosphor using the magnetic Archimedes separation method. •In this method, vertical and radial components of the magnetic force were used. •We succeeded to separate HP and developed the continuous separation system. •The separation system enables successive separation and recovery of HP. -- Abstract: The phosphor wastes consist of phosphors with different emission colors, green (LAP), red (YOX), blue (BAM) and white (HP). It is required to recover and reuse the rare earth phosphors with high market value. In this study, we tried to separate the phosphor using the magnetic separation by HTS bulk magnet utilizing the differences of magnetic susceptibility by the type of phosphors. We succeeded in the successive separation of HP with low market value from YOX and BAM including the rare earth using the magnetic Archimedes method. In this method, vertical and radial components of the magnetic force were used.

  5. Parametric study on sequential deconvolution for force identification

    Science.gov (United States)

    Lai, Tao; Yi, Ting-Hua; Li, Hong-Nan

    2016-09-01

    The force identification can be mathematically viewed as the mapping from the observed responses to external forces through a matrix filled with system Markov parameters, which makes it difficult or even impossible for long time duration. A potentially efficient solution is to sequentially perform the identification processing. This paper presents a parametric study on the sequential deconvolution input reconstruction (SDR) method, which was proposed by Bernal. The behavior of the SDR method due to the effects of window parameters, noise levels and sensor configurations is investigated. In addition, a new normalized standard deviation of the reconstruction error over time is derived to cover the effect of only independent noise entries. The sinusoidal and band-limited white noise excitations are tested to be identified with good accuracy even with 10% noise. The simulation results yield various conclusions that may be helpful to engineering practitioners.

  6. Laboratory study of forced rotating shallow water turbulence

    Science.gov (United States)

    Espa, Stefania; Di Nitto, Gabriella; Cenedese, Antonio

    2011-12-01

    During the last three decades several authors have studied the appearance of multiple zonal jets in planetary atmospheres and in the Earths oceans. The appearance of zonal jets has been recovered in numerical simulations (Yoden & Yamada, 1993), laboratory experiments (Afanasyev & Wells, 2005; Espa et al., 2008, 2010) and in field measurements of the atmosphere of giant planets (Galperin et al., 2001). Recent studies have revealed the presence of zonation also in the Earths oceans, in fact zonal jets have been found in the outputs of Oceanic General Circulation Models-GCMs (Nakano & Hasumi, 2005) and from the analysis of satellite altimetry observations (Maximenko et al., 2005). In previous works (Espa et al., 2008, 2010) we have investigated the impact of the variation of the rotation rate and of the fluid depth on jets organization in decaying and forced regimes. In this work we show results from experiments performed in a bigger domain in which the fluid is forced continuously. The experimental set-up consists of a rotating tank (1m in diameter) where the initial distribution of vorticity has been generated via the Lorentz force in an electromagnetic cell. The latitudinal variation of the Coriolis parameter has been simulated by the parabolic profile assumed by the free surface of the rotating fluid. Flow measurements have been performed using an image analysis technique. Experiments have been performed changing the tank rotation rate and the fluid thickness. We have investigated the flow in terms of zonal and radial flow pattern, flow variability and jet scales.

  7. The study of magnetization of the spin systm in the ground state

    Institute of Scientific and Technical Information of China (English)

    Jiang Wei; Wang Xi-Kun; Zhao Qiang

    2006-01-01

    Within the framework of the effective-field theory with self-spin correlations and the differential operator technique,the ground state magnetizations of the biaxial crystal field spin system on the honeycomb lattices have been studied.The influences of the biaxial crystal field on the magnetization in the ground state have been investigated in detail.

  8. Theoretical study on thermal decomposition of azoisobutyronitrile in ground state

    Institute of Scientific and Technical Information of China (English)

    SUN Chengke; ZHAO Hongmei; LI Zonghe

    2004-01-01

    The thermal decomposition mechanisms of azoisobutyronitrile (AIBN) in the ground state have been investigated systematically. Based on the potential energy surfaces (PES) of various possible dissociation paths obtained using the semiempirical AM1 method with partial optimization, the density function theory B3LYP/6-311G* method was employed to optimize the geometric parameters of the reactants, the intermediates, the products and the transition states,which were further confirmed by the vibrational analysis. The obtained results show that the reaction process of the two-bond (three-body) simultaneous cleavage Me2(CN)C-N=Nleading to the reaction proceeding in the former pathway. The calculation results were consistent with all the experimental facts.

  9. Dissipation and oscillatory solvation forces in confined liquids studied by small-amplitude atomic force spectroscopy

    NARCIS (Netherlands)

    Beer, de Sissi; Ende, van den Dirk; Mugele, Frieder

    2010-01-01

    We determine conservative and dissipative tip–sample interaction forces from the amplitude and phase response of acoustically driven atomic force microscope (AFM) cantilevers using a non-polar model fluid (octamethylcyclotetrasiloxane, which displays strong molecular layering) and atomically flat su

  10. PRELIMINARY STUDIES OF RIVETED JOINTS AT FEED FORCE

    Directory of Open Access Journals (Sweden)

    Radosław Bielawski

    2015-08-01

    Full Text Available The aim of the study was to determine the feasibility of riveted joints in composites materials. Static tensile test method was used. In the test one type of glass fabric was used (Interglas 92140 from which two types of composite samples were prepared. In each sample the same type of fiber with the same fiber orientation – 3 layers - was used. The samples had dimensions of 100×100 mm and thickness of approximately 1 mm. The composite probes were located in a metal frame with a screw connection which was made of screws with nominal thread pitch M5. Screws were tightened with constant torque. It was to provide an axial force to the sample during the tensile test. The frame was placed between cross-bars of tensile machine INSTRON 8516. The samples were stretched at a speed of 0.05 mm/s at a distance up to 16 mm. During the tensile test displacement of the samples and pull force were registered. Depending on the fibre orientations and the value of feed force, damage models were described. On the basis of the results the possibility of usage of aluminium rivet nuts connections in composite materials was determined.

  11. STATIC STUDY OF CANTILEVER BEAM STICTION UNDER ELECTROSTATIC FORCE INFLUENCE

    Institute of Scientific and Technical Information of China (English)

    ZhangYin; ZhaoYa-pu

    2004-01-01

    The model and analysis of the cantilever beam adhesion problem under the action of electrostatic force are given. Owing to the nonlinearity of electrostatic force, the analytical solution for this kind of problem is not available. In this paper, a systematic method of generating polynomials which are the exact beam solutions of the loads with different distributions is provided. The polynomials are used to approximate the beam displacement due to electrostatic force. The equilibrium equation offers an answer to how the beam deforms but no information about the unstuck length. The derivative of the functional with respect to the unstuck length offers such information. But to compute the functional it is necessary to know the beam deformation, So the problem is iteratively solved until the results are converged. Galerkin and Newton-Raphson methods are used to solve this nonlinear problem. The effects of dielectric layer thickness and electrostatic voltage on the cantilever beam stiction are studied. The method provided in this paper exhibits good convergence. For the adhesion problem of cantilever beam without electrostatic voltage, the analytical solution is available and is also exactly matched by the computational results given by the method presented in this paper.

  12. Megacity Radiative Forcing: A Mexico City Case Study

    Science.gov (United States)

    Dubey, M.; Olsen, S.; Mazzoleni, C.; Chylek, P.; Zhang, Y.; Randerson, J. T.; Horowitz, L.

    2007-05-01

    We assess the radiative forcing of the largest megacity in North America, Mexico City. While particular aspects of the regional environmental impacts of cities on their surroundings have been thoroughly investigated, e.g., air quality and acid rain, relatively little effort has been focused on the net radiative impact of a megacity on global climate. The range of radiative impacts from a megacity covers many spatial and temporal scales from short-term regional-scale effects due to aerosols and relatively short-lived gases (ozone) to long-term global-scale impacts due to longer-lived trace gases (e.g., carbon dioxide, methane). In this study we combine chemistry-transport model simulations from the Model for Ozone And Related Chemical Tracers (MOZART-2) with in situ and satellite observations from the Aerosol Robotic Network (AERONET) and the Moderate Resolution Imaging Spectroradiometer (MODIS) to calculate the global radiative forcing of megacity emissions. We also explore the radiative impact of various emission control strategies that focus on improving regional air quality. Our results suggest that the warming by greenhouse gases like carbon dioxide and ozone can be moderated or exacerbated by aerosols depending on their optical properties. As the size and number of megacities increase and clean air regulations are implemented, metrics such as the net radiative forcing may become increasingly important in comparing the impact of urban centers and assessing the trade-offs between improving local air quality and minimizing global radiative impacts.

  13. A study on forces acting on a flapping wing

    OpenAIRE

    Cetiner O.; Fenercioglu I.; Vuruskan A.

    2013-01-01

    In order to study the forces acting on a flapping wing, an experimental investigation is performed in steady water flow. In this study, a SD7003 airfoil undergoes combined pitching and plunging motion which simulates the forward flight of small birds. The frequency of pitching motion is equal to the frequency of plunging motion and pitch leads the plunge by a phase angle of 90 degrees. The experiments are conducted at Reynolds numbers of 2500 ≤ Re ≤ 13700 and the vortex formation is recorded ...

  14. Numerical Study of Wake Vortex Interaction with the Ground Using the Terminal Area Simulation System

    Science.gov (United States)

    Proctor, Fred H.; Han, Jongil

    1999-01-01

    A sensitivity study for the in-ground effect on aircraft wake vortices has been conducted using a validated large eddy simulation model. The numerical results are compared with observed data and show good agreement for vortex decay and lateral vortex transport. The vortex decay rate is strongly influenced by the ground, but appears somewhat insensitive to ambient turbulence. In addition, the results show that the ground can affect the trajectory and descent-rate of a wake vortex pair at elevations up to about 3 b(sub o) (where b(sub o) is the initial vortex separation). However, the ground does not influence the average circulation of the vortices until the cores descend to within about 0.6 b(sub o), after which time the ground greatly enhances their rate of demise. Vortex rebound occurs in the simulations, but is more subtle than shown in previous numerical studies.

  15. The CMS Experiment: on and under Ground Motions of Structures Due to the Magnetic Field Forces as Observed by the Link Alignment System

    Energy Technology Data Exchange (ETDEWEB)

    Alberdi, J.; Arce, J.; Barcala, J. M.; Calvo, E.; Ferrando, A.; Josa, M. I.; Molinero, A.; Navarrete, J.; Oller, J. C.; Yuste, C.; Brochero, J.; Calderon, A.; Fernandez, M. G.; Gomez, G.; Gonzalez-Sanchez, F. J.; Martinez-Ribero, C.; Matorras, F.; Rodrigo, T.; Rui-Arbol, P.; Scodellaro, L.; Sobron, M.; Vila, I.; Virto, A. L.; Fernandez, J.

    2010-05-01

    This document describes results obtained from the Link Alignment System data recorded during the CMS Magnet Test (at SX5 on ground Hall) and the CRAFT08 and 09 periods data taking in the point P5 (UX5), 100 m underground. A brief description of the system is followed by the discussion of the detected relative displacements (from micrometres to centimetres) between detector elements and rotation of detector structures (from microradiants to milliradiants). Observed motions are studied as functions of the magnetic fi eld intensity. Comparisons between recorded data on and under ground are made. (Author) 23 refs.

  16. Is it really theoretical? A review of sampling in grounded theory studies in nursing journals.

    Science.gov (United States)

    McCrae, Niall; Purssell, Edward

    2016-10-01

    Grounded theory is a distinct method of qualitative research, where core features are theoretical sampling and constant comparative analysis. However, inconsistent application of these activities has been observed in published studies. This review assessed the use of theoretical sampling in grounded theory studies in nursing journals. An adapted systematic review was conducted. Three leading nursing journals (2010-2014) were searched for studies stating grounded theory as the method. Sampling was assessed using a concise rating tool. A high proportion (86%) of the 134 articles described an iterative process of data collection and analysis. However, half of the studies did not demonstrate theoretical sampling, with many studies declaring or indicating a purposive sampling approach throughout. Specific reporting guidelines for grounded theory studies should be developed to ensure that study reports describe an iterative process of fieldwork and theoretical development. © 2016 John Wiley & Sons Ltd.

  17. A Study of Ground Deformation in the Guangzhou Urban Area with Persistent Scatterer Interferometry

    Directory of Open Access Journals (Sweden)

    Qing Zhao

    2009-01-01

    Full Text Available TheInterferometric Point Target Analysis (IPTA technique and Advanced Synthetic Aperture Radar (ASAR images acquired over Hong Kong from 2007–2008 were used to detect ground deformation in the urban area of Guangzhou city in South China. A ground deformation rate map with scattered distribution of point targets shows the maximum subsidence (rise rate as high as -26 to -20 mma-1 (16–21 mma-1, implying that the study area is an active zone for ground deformation. Based on the point target map, a contour ground deformation rate map is generated. The map shows three major subsidence zones located in the middle-west, the east, and the southwest of the study area, respectively. All the six ground collapse accidents that occurred in 2007–2008 fall within the subsidence zones, qualitatively validating the IPTA results. Ground subsidence and geological conditions on Datansha Island are examined. The results indicate that the local geological conditions, such as limestone Karst geomorphology as well as silt layers characterized by high water content, high void ratio, high compressibility, low bearing capacity and low shear strength, and underground engineering projects are responsible for ground subsidence and ground collapse accidents occurred there.

  18. A study of ground deformation in the guangzhou urban area with persistent scatterer interferometry.

    Science.gov (United States)

    Zhao, Qing; Lin, Hui; Jiang, Liming; Chen, Fulong; Cheng, Shilai

    2009-01-01

    The Interferometric Point Target Analysis (IPTA) technique and Advanced Synthetic Aperture Radar (ASAR) images acquired over Hong Kong from 2007-2008 were used to detect ground deformation in the urban area of Guangzhou city in South China. A ground deformation rate map with scattered distribution of point targets shows the maximum subsidence (rise) rate as high as -26 to -20 mma(-1) (16-21 mma(-1)), implying that the study area is an active zone for ground deformation. Based on the point target map, a contour ground deformation rate map is generated. The map shows three major subsidence zones located in the middle-west, the east, and the southwest of the study area, respectively. All the six ground collapse accidents that occurred in 2007-2008 fall within the subsidence zones, qualitatively validating the IPTA results. Ground subsidence and geological conditions on Datansha Island are examined. The results indicate that the local geological conditions, such as limestone Karst geomorphology as well as silt layers characterized by high water content, high void ratio, high compressibility, low bearing capacity and low shear strength, and underground engineering projects are responsible for ground subsidence and ground collapse accidents occurred there.

  19. Grounded theory.

    Science.gov (United States)

    Harris, Tina

    2015-04-29

    Grounded theory is a popular research approach in health care and the social sciences. This article provides a description of grounded theory methodology and its key components, using examples from published studies to demonstrate practical application. It aims to demystify grounded theory for novice nurse researchers, by explaining what it is, when to use it, why they would want to use it and how to use it. It should enable nurse researchers to decide if grounded theory is an appropriate approach for their research, and to determine the quality of any grounded theory research they read.

  20. A taxonomy of dignity: a grounded theory study

    Directory of Open Access Journals (Sweden)

    Jacobson Nora

    2009-02-01

    Full Text Available Abstract Background This paper has its origins in Jonathan Mann's insight that the experience of dignity may explain the reciprocal relationships between health and human rights. It follows his call for a taxonomy of dignity: "a coherent vocabulary and framework to characterize dignity." Methods Grounded theory procedures were use to analyze literature pertaining to dignity and to conduct and analyze 64 semi-structured interviews with persons marginalized by their health or social status, individuals who provide health or social services to these populations, and people working in the field of health and human rights. Results The taxonomy presented identifies two main forms of dignity–human dignity and social dignity–and describes several elements of these forms, including the social processes that violate or promote them, the conditions under which such violations and promotions occur, the objects of violation and promotion, and the consequences of dignity violation. Together, these forms and elements point to a theory of dignity as a quality of individuals and collectives that is constituted through interaction and interpretation and structured by conditions pertaining to actors, relationships, settings, and the broader social order. Conclusion The taxonomy has several implications for work in health and human rights. It suggests a map to possible points of intervention and provides a language in which to talk about dignity.

  1. Wavelet analysis for ground penetrating radar applications: a case study

    Science.gov (United States)

    Javadi, Mehdi; Ghasemzadeh, Hasan

    2017-10-01

    Noises may significantly disturb ground penetrating radar (GPR) signals, therefore, filtering undesired information using wavelet analysis would be challenging, despite the fact that several methods have been presented. Noises are gathered by probe, particularly from deep locations, and they may conceal reflections, suffering from small altitudes, because of signal attenuation. Multiple engineering fields need data analysis to distinguish valued material, based on information obtained by underground observations. Using wavelets as one of the useful methods for analyzing data is considered in this paper. However, optimal wavelet analysis would be challenging in the realm of exploring GPR signals. There is no doubt that accounting for wavelet function, decomposition level, threshold estimation method and threshold transformation, in the matter of de-noising and investigating signals, is of great importance; they must be chosen with judgment as they influence the results enormously if they are not carefully designated. Multiple wavelet functions are applied to perform de-noising and reconstruction on synthetic noisy signals generated by the finite-difference time-domain (FDTD) method to account for the most appropriate function for the purpose. In addition, various possible decomposition levels, threshold estimation methods and threshold transformations in the de-noising procedure are tested. The optimal wavelet analysis is also evaluated by examining real data acquired from several antenna frequencies which are common in engineering practice.

  2. Prognostics for Ground Support Systems: Case Study on Pneumatic Valves

    Science.gov (United States)

    Daigle, Matthew; Goebel, Kai

    2011-01-01

    Prognostics technologies determine the health (or damage) state of a component or sub-system, and make end of life (EOL) and remaining useful life (RUL) predictions. Such information enables system operators to make informed maintenance decisions and streamline operational and mission-level activities. We develop a model-based prognostics methodology for pneumatic valves used in ground support equipment for cryogenic propellant loading operations. These valves are used to control the flow of propellant, so failures may have a significant impact on launch availability. Therefore, correctly predicting when valves will fail enables timely maintenance that avoids launch delays and aborts. The approach utilizes mathematical models describing the underlying physics of valve degradation, and, employing the particle filtering algorithm for joint state-parameter estimation, determines the health state of the valve and the rate of damage progression, from which EOL and RUL predictions are made. We develop a prototype user interface for valve prognostics, and demonstrate the prognostics approach using historical pneumatic valve data from the Space Shuttle refueling system.

  3. Atomic force microscopy to study intermolecular forces and bonds associated with bacteria.

    Science.gov (United States)

    Lower, Steven K

    2011-01-01

    Atomic force microscopy (AFM) operates on a very different principle than other forms of microscopy, such as optical microscopy or electron microscopy. The key component of an AFM is a cantilever that bends in response to forces that it experiences as it touches another surface. Forces as small as a few picoNewtons can be detected and probed with AFM. AFM has become very useful in biological sciences because it can be used on living cells that are immersed in water. AFM is particularly useful when the cantilever is modified with chemical groups (e.g. amine or carboxylic groups), small beads (e.g. glass or latex), or even a bacterium. This chapter describes how AFM can be used to measure forces and bonds between a bacterium and another surface. This paper also provides an example of the use of AFM on Staphylococcus aureus, a Gram-positive bacterium that is often associated with biofilms in humans.

  4. Study on Simulation of Machining Errors Caused by Cutting Force

    Institute of Scientific and Technical Information of China (English)

    SHAO Xiaodong; ZHANG Liu; LIN Zhaoxu

    2006-01-01

    Machining errors caused by cutting force are studied in this paper, and an algorithm to simulate errors is putted forward. In the method, continuous machining process is separated into many machining moments. The deformation of work-piece and cutter at every moment is calculated by finite element method. The machined work-piece is gained by Boolean operation between deformed work-piece and cutter. By analyzing data of final work-piece, machining errors are predicted. The method is proved true by experiment.

  5. Living with coeliac disease: a grounded theory study.

    Science.gov (United States)

    Rose, C; Howard, R

    2014-02-01

    Coeliac disease can be controlled only through adherence to a gluten-free diet. This diet is highly restrictive and can be challenging to maintain. It has been linked with elevated levels of psychological distress, including depression, anxiety and social phobia. Narratives on living with coeliac disease were written by 130 adult members of Coeliac UK (mean age 52.7 years; mean time since diagnosis 10.2 years; 67% sample female; 28% male). Qualitative analysis using grounded theory methods identified five key categories: living with widespread ignorance; social invisibility; creating a coeliac community; a changed identity; grief - and accepting the trade-off. A psychosocial model of living with coeliac disease was constructed from the findings, the central category of which was the changed identity of those diagnosed with the condition. Grief was experienced in relation to a loss of the former diet, changed personal and social identities, loss of social confidence and loss of social activities. Grief was generally mitigated over time as adjustments were made to changes in identity and lifestyle. Creating (or becoming part of) a coeliac community was a strategy enabling those with coeliac disease to re-establish their identities and increase social recognition and acceptance of the condition. Gluten-free living entails a substantial restriction of food choice. The losses and changes entailed impact on the personal and social identities of those living with coeliac disease, and on the behaviour of others towards them. Psychosocial interventions focussed on facilitating coping and adjustment may benefit those experiencing difficulties. © 2013 The Authors Journal of Human Nutrition and Dietetics © 2013 The British Dietetic Association Ltd.

  6. The cost of leg forces in bipedal locomotion: a simple optimization study.

    Directory of Open Access Journals (Sweden)

    John R Rebula

    Full Text Available Simple optimization models show that bipedal locomotion may largely be governed by the mechanical work performed by the legs, minimization of which can automatically discover walking and running gaits. Work minimization can reproduce broad aspects of human ground reaction forces, such as a double-peaked profile for walking and a single peak for running, but the predicted peaks are unrealistically high and impulsive compared to the much smoother forces produced by humans. The smoothness might be explained better by a cost for the force rather than work produced by the legs, but it is unclear what features of force might be most relevant. We therefore tested a generalized force cost that can penalize force amplitude or its n-th time derivative, raised to the p-th power (or p-norm, across a variety of combinations for n and p. A simple model shows that this generalized force cost only produces smoother, human-like forces if it penalizes the rate rather than amplitude of force production, and only in combination with a work cost. Such a combined objective reproduces the characteristic profiles of human walking (R² = 0.96 and running (R² = 0.92, more so than minimization of either work or force amplitude alone (R² = -0.79 and R² = 0.22, respectively, for walking. Humans might find it preferable to avoid rapid force production, which may be mechanically and physiologically costly.

  7. The cost of leg forces in bipedal locomotion: a simple optimization study.

    Science.gov (United States)

    Rebula, John R; Kuo, Arthur D

    2015-01-01

    Simple optimization models show that bipedal locomotion may largely be governed by the mechanical work performed by the legs, minimization of which can automatically discover walking and running gaits. Work minimization can reproduce broad aspects of human ground reaction forces, such as a double-peaked profile for walking and a single peak for running, but the predicted peaks are unrealistically high and impulsive compared to the much smoother forces produced by humans. The smoothness might be explained better by a cost for the force rather than work produced by the legs, but it is unclear what features of force might be most relevant. We therefore tested a generalized force cost that can penalize force amplitude or its n-th time derivative, raised to the p-th power (or p-norm), across a variety of combinations for n and p. A simple model shows that this generalized force cost only produces smoother, human-like forces if it penalizes the rate rather than amplitude of force production, and only in combination with a work cost. Such a combined objective reproduces the characteristic profiles of human walking (R² = 0.96) and running (R² = 0.92), more so than minimization of either work or force amplitude alone (R² = -0.79 and R² = 0.22, respectively, for walking). Humans might find it preferable to avoid rapid force production, which may be mechanically and physiologically costly.

  8. Study of Atmospheric Forcing and Responses (SAFAR campaign: overview

    Directory of Open Access Journals (Sweden)

    A. Jayaraman

    2010-01-01

    Full Text Available Study of Atmospheric Forcing and Responses (SAFAR is a five year (2009–2014 research programme specifically to address the responses of the earth's atmosphere to both natural and anthropogenic forcings using a host of collocated instruments operational at the National Atmospheric Research Laboratory, Gadanki (13.5° N, 79.2° E, India from a unified viewpoint of studying the vertical coupling between the forcings and responses from surface layer to the ionosphere. As a prelude to the main program a pilot campaign was conducted at Gadanki during May–November 2008 using collocated observations from the MST radar, Rayleigh lidar, GPS balloonsonde, and instruments measuring aerosol, radiation and precipitation, and supporting satellite data. We show the importance of the large radiative heating caused by absorption of solar radiation by soot particles in the lower atmosphere, the observed high vertical winds in the convective updrafts extending up to tropopause, and the difficulty in simulating the same with existing models, the upward traveling waves in the middle atmosphere coupling the lower atmosphere with the upper atmosphere, their manifestation in the mesospheric temperature structure and inversion layers, the mesopause height extending up to 100 km, and the electro-dynamical coupling between mesosphere and the ionosphere which causes irregularities in the ionospheric F-region. The purpose of this communication is not only to share the knowledge that we gained from the SAFAR pilot campaign, but also to inform the international atmospheric science community about the SAFAR program as well as to extend our invitation to join in our journey.

  9. A BASIC STUDY FOR GRAVITY SURVEY USING A FORCE-BALANCED-TYPE ACCELEROMETER

    Science.gov (United States)

    Matsuo, Hiroko; Morikawa, Hitoshi; Matsuda, Shigeo; Tokue, Satoshi; Komazawa, Masao; Kusumoto, Shigekazu

    The gravity survey is applied to model a ground structure. For this purpose, a spring-type relative gravimeter is usually used. Though this type of gravimeter can provide very accurate data, it is very expensive and difficult to handle. This means that a simple and inexpensive sensor to measure the gravity is required. For this, we began to develop a new gravimeter using a force-balanced-type accelerometer. In this study, we develop a preliminary system and calibrate it. Then, a simple measurements is carried out on an observation wheel, on a car, and on a ship. The gravity data is contaminated by vibration of carriers, though we found a technique of blind source separation can be hopeful to pick up gravity data from the observed data. However, we also recognized some problems that needs to be solved.

  10. An Experimental Study of the Cutting Forces in Metal Turning

    Directory of Open Access Journals (Sweden)

    Zoltan Iosif Korka

    2013-09-01

    Full Text Available Cutting forces are classified among the most important technological parameters in machining process. Cutting forces are the background for the evaluation of the necessary machining power, as well as for dimensioning of the tools. Cutting forces are also having a major influence on the deformation of the work piece machined, its dimensional accuracy, and machining system stability.

  11. Self-perceived participation among adults with spinal cord injury: a grounded theory study

    National Research Council Canada - National Science Library

    Ripat, J D; Woodgate, R L

    2012-01-01

    A grounded theory study of 19 adults with spinal cord injury was conducted. Participants engaged in individual in-depth interviews, and took photographs of aspects of their environment that promoted and restricted participation...

  12. Study area boundary for the Death Valley regional ground-water flow system, Nevada and California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital data set represents the Death Valley regional ground-water flow system (DVRFS) study area which encompasses approximately 100,000-square kilometers in...

  13. Study area boundary for the Death Valley regional ground-water flow system, Nevada and California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital data set represents the Death Valley regional ground-water flow system (DVRFS) study area which encompasses approximately 100,000-square kilometers in...

  14. A numerical study of microparticle acoustophoresis driven by acoustic radiation forces and streaming-induced drag forces

    DEFF Research Database (Denmark)

    Muller, Peter Barkholt; Barnkob, Rune; Jensen, Mads Jakob Herring;

    2012-01-01

    We present a numerical study of the transient acoustophoretic motion of microparticles suspended in a liquid-filled microchannel and driven by the acoustic forces arising from an imposed standing ultrasound wave: the acoustic radiation force from the scattering of sound waves on the particles...... parameters using a numerical particle-tracking scheme. The model shows the transition in the acoustophoretic particle motion from being dominated by streaming-induced drag to being dominated by radiation forces as a function of particle size, channel geometry, and material properties....

  15. Reproducibility of the spatio-temporal variables and the ground reaction forces walking with fire fighting boots REPRODUCIBILIDAD DE LAS VARIABLES ESPACIO-TEMPORALES Y DE LAS COMPONENTES DE LA FUERZA DE REACCIÓN DEL SUELO EN LA MARCHA CON BOTAS DE BOMBERO [Reproducibility of the spatio-temporal variables and the ground reaction forces walking with fire fighting boo

    Directory of Open Access Journals (Sweden)

    Begoña Gavilanes

    2010-11-01

    Full Text Available AbstractThe aim of this study is to analyze the reproducibility of the spatio-temporal variables and the ground reaction forces (GRF when walking with fire fighting boots in comparison to walking with low calf shoes. Spatio-temporal parameters and the variables related to the three components of the GRF of 39 people were recorded under two different walking conditions. A T-test to contrast the difference between the coefficients of variation (CV in both conditions was used. The CV of the spatio-temporal variables (i.e velocity (V, condition I = 2.01%; condition II = 1.81%, of the vertical (i.e. contact force (FZA of the left foot, condition I = 2.54%; condition II = 2.73% and of the antero-posterior GRF (i.e. maximum force (FXMAX of the left foot, condition I = 4.47%; condition II = 4.59% was lower than 12.5%, suggesting that these variables could be used to analyze the influence of fire fighting boots on the gait. However, the low reproducibility showed by medium-lateral parameters does not allow to use them. Apart from the bipodal phase no differences were found between the two walking conditions. Key words: biomechanics, footwear, variability.ResumenEl objetivo del presente trabajo es analizar la reproducibilidad de las variables espacio-temporales y de la fuerza de reacción del suelo (FRS durante la marcha con botas de bombero y compararla con la mostrada durante la marcha con calzado de cuero sin caña. Se registraron las variables espacio-temporales de 39 personas así como las variables que definen las tres componentes de la FRS con dos tipos de calzado diferente. Se utilizó la prueba T para contrastar la hipótesis referida a la diferencia del coeficiente de variación (CV entre los dos tipos de calzado. El CV de las variables espacio-temporales (p. ej. velocidad (V, condición I = 2,01%; condición II = 1,81%, así como de las que definen la componente vertical (p. ej. fuerza de apoyo (FZA del pie izquierdo, condición I = 2

  16. Atomic force microscope study of three-dimensional nanostructure sidewalls

    Energy Technology Data Exchange (ETDEWEB)

    Hussain, Muhammad Mustafa [SEMATECH, 2706 Montopolis Drive, Austin, TX 78741 (United States); Gondran, Carolyn F H [Advanced Technology Development Facility, 2706 Montopolis Drive, Austin, TX 78741 (United States); Michelson, Diane K [International SEMATECH Manufacturing Initiative, 2706 Montopolis Drive, Austin, TX 78741 (United States)

    2007-08-22

    Next generation planar and non-planar complementary metal oxide semiconductor (CMOS) structures are three-dimensional nanostructures with multi-layer stacks that can contain films thinner than ten atomic layers. The high resolution of transmission electron microscopy (TEM) is typically chosen for studying properties of these stacks such as film thickness, interface and interfacial roughness. However, TEM sample preparation is time-consuming and destructive, and TEM analysis is expensive and can provide problematic results for surface and interface roughness. Therefore, in this paper, we present the use of direct measurements of sidewall surface structures by conventional atomic force microscopy (AFM) as an alternative or complementary method for studying multi-layer film stacks and as the preferred method for studying FinFET sidewall surface roughness. In addition to these semiconductor device applications, this AFM sidewall measurement technique could be used for other three-dimensional nanostructures.

  17. The advances in airglow study and observation by the ground-based airglow observation network over China

    Science.gov (United States)

    Xu, Jiyao; Li, Qinzeng; Yuan, Wei; Liu, Xiao; Liu, Weijun; Sun, Longchang

    2017-04-01

    Ground-based airglow observation networks over China used to study airglow have been established, which contains 15 stations. Some new results were obtained using the networks. For OH airglow observations, firstly, an unusual outbreak of Concentric Gravity Wave (CGW) events were observed by the first no-gap network nearly every night during the first half of August 2013. Combination of the ground imager network with satellites provides multilevel observations of the CGWs from the troposphere to the mesopause region. Secondly, three-year OH airglow images (2012-2014) from Qujing (25.6°N, 103.7°E) were used to study how orographic features of the Tibetan Plateau (TP) affect the geographical distributions of gravity wave (GW) sources. We find the orographic forcings have a significant impact on the gravity wave propagation features. Thirdly, ground-based observations of the OH (9-4, 8-3, 6-2, 5-1, 3-0) band airglow over Xinglong (40°2N, 117°4E) in northern China from 2012 to 2014 are used to calculate rotational temperatures. By comparing the ground-based OH rotational temperature with SABER's observations, five Einstein coefficient datasets are evaluated. We find rotational temperatures determined using any of the available Einstein coefficient datasets have systematic errors. We have obtained a set of optimal Einstein coefficients ratios for rotational temperature derivation using three years data from ground-based OH spectra and SABER temperatures. For the OI 630.0 nm airglow observations, we used three-year (2011-2013) observations of thermospheric winds (at 250 km) by Fabry-Perot interferometers at Xinglong to study the climatology of atmospheric planetary wave-type oscillations (PWTOs) with periods of 4-19 days. We found these PWTOs occur more frequently in the months from May to October. They are consistent with the summertime preference of middle-latitude ionospheric electron density oscillations noted in other studies. By using an all-sky airglow imager

  18. Brown algal morphogenesis: Atomic Force Microscopy as a tool to study the role of mechanical forces

    Directory of Open Access Journals (Sweden)

    Benoit eTesson

    2014-09-01

    Full Text Available Over the last few years, a growing interest has been directed toward the use of macroalgae as a source of energy, food and molecules for the cosmetic and pharmaceutical industries. Besides this, macroalgal development remains poorly understood compared to other multicellular organisms. Brown algae (Phaeophyceae form a monophyletic lineage of usually large multicellular algae which evolved independently from land plants. In their environment, they are subjected to strong mechanical forces (current, waves and tide, in response to which they modify rapidly and reversibly their morphology. Because of their specific cellular features (cell wall composition, cytoskeleton organization, deciphering how they cope with these forces might help discover new control mechanisms of cell wall softening and cellulose synthesis. Despite the current scarcity in knowledge on brown algal cell wall dynamics and protein composition, we will illustrate, in the light of methods adapted to Ectocarpus siliculosus, to what extent atomic force microscopy can contribute to advance this field of investigation.

  19. Study of Slope Reinforcement Force Based on FLAC

    Institute of Scientific and Technical Information of China (English)

    HUANG Xian-wu; MAO xian-biao; MIAO Xie-xing; CHEN Zhan-qing

    2006-01-01

    A slope will slide if the unbalanced force does not tend to zero when the stability of the slope is analyzed with the help of FLAC. Thus the ultimate reason of slope sliding is the unbalanced force determined by FLAC. The slope will remain stable if the unbalanced force is counterbalanced by a reinforcement force which is produced by a suitable reinforcement method. In this paper, the stability of the slope was analyzed by using FLAC, and the unbalanced force of the slope was obtained through the FISH function in FLAC. According to the equilibrium conditions, the relationship between the reinforcement force and unbalanced force was derived and accordingly the reinforcement force was determined. The reinforcement design was adopted by using pre-stressed anchor bars on the basis of the reinforcement force. An example is used to show that the effect of slope reinforcement based on the reinforcement force is safe and economical. The method doesn't need to suppose a sliding surface to obtain the reinforcement force, and it is also clear in physical meaning. So this method realized the organic unification of the stability analysis and the slope reinforcement

  20. Estimation of shortwave direct aerosol radiative forcing at four locations on the Indo-Gangetic plains: Model results and ground measurement

    Science.gov (United States)

    Bibi, Humera; Alam, Khan; Bibi, Samina

    2017-08-01

    This study provides observational results of aerosol optical and radiative characteristics over four locations in IGP. Spectral variation of Aerosol Optical Depth (AOD), Single Scattering Albedo (SSA) and Asymmetry Parameter (AP) were analysed using AErosol RObotic NETwork (AERONET) data. The analysis revealed that coarse particles were dominant in summer and pre-monsoon, while fine particles were more pronounced in winter and post-monsoon. Furthermore, the spatio-temporal variations of Shortwave Direct Aerosol Radiative Forcing (SDARF) and Shortwave Direct Aerosol Radiative Forcing Efficiency (SDARFE) at the Top Of Atmosphere (TOA), SURface (SUR) and within ATMosphere (ATM) were calculated using SBDART model. The atmospheric Heating Rate (HR) associated with SDARFATM were also computed. It was observed that the monthly averaged SDARFTOA and SDARFSUR were found to be negative leading to positive SDARFATM during all the months over all sites. The increments in net atmospheric forcing lead to maximum HR in November-December and May. The seasonal analysis of SDARF revealed that SDARFTOA and SDARFSUR were negative during all seasons. The SW atmospheric absorption translates to highest atmospheric HR during summer over Karachi and during pre-monsoon over Lahore, Jaipur and Kanpur. Like SDARF, the monthly and seasonal variations of SDARFETOA and SDARFESUR were found to be negative, resulting in positive atmospheric forcing. Additionally, to compare the model estimated forcing against AERONET derived forcing, the regression analysis of AERONET-SBDART forcing were carried out. It was observed that SDARF at SUR and TOA showed relatively higher correlation over Lahore, moderate over Jaipur and Kanpur and lower over Karachi. Finally, the analysis of National Oceanic and Atmospheric Administration Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) model revealed that air masses were arriving from multiple source locations.

  1. Theoretical and Experimental Study on Ground Coupled Heat Pump with Vertical Spiral Coil

    Institute of Scientific and Technical Information of China (English)

    李新国; 周倩; 赵军; 朱强; 胡璟

    2003-01-01

    The numerical simulation study on the temperature distribution of underground field for the ground coupled heat pump (GCHP) with vertical spiral coil was carried out by using finite element. The distribution and recovery of underground field temperature under different operation ratio and the optimal operation ratio were simulated. The performance parameters, i.e. inlet and outlet temperature of the ground spiral coil in heating and cooling modes were tested, the heat extracted or emitted by the heat pump to the ground was calculated, and the coefficients of performance (COP) of GCHP at heating and cooling modes were analyzed.

  2. Atomic force microscope chamber for in situ studies of ice

    Science.gov (United States)

    Zepeda, Salvador; Yeh, Yin; Orme, Christine A.

    2001-11-01

    To investigate the surface morphologies of biological systems in a controlled gaseous environment (e.g., the temperature, humidity and composition), most commercial atomic force microscopes require modification. We have designed a double-jacketed environmental chamber specifically for a Nanoscope IIIa (Digital Instruments, Santa Barbara, CA) force microscope. We use cold nitrogen and thermoelectric devices to control the temperature in the chamber; the nitrogen simultaneously serves to create an inert environment. We have also designed a temperature controlled sample stage utilizing thermoelectric devices for fine temperature regulation. A variation of this sample stage allows us to image samples in fluids at cold temperatures with an O-ringless configuration. The relative humidity within the chamber is also measured with commercially available relative humidity sensors. We investigate the surface morphology of ice Ih in its pure phase and shall extend the study to ice in the presence of biological molecules, such as antifreeze proteins. We present a detailed description of our design and our first images of polycrystalline ice and single crystals of ice grown in situ from the vapor.

  3. Tribology studies of organic thin films by scanning force microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Bar, G. [Albert-Ludwigs Univ., Freiburg (Germany). Freiburger Materialforschungszentrum; Rubin, S.; Parikh, A.N.; Swanson, B.I.; Zawodzinski, T.A. [Los Alamos National Lab., NM (United States)

    1996-06-01

    The use of organic thin films as lubricants on solid surfaces is important in many modern technologies including magnetic storage and micromachines. Langmuir-Blodgett (LB) films and self-assembled monolayers (SAMs) are attractive candidates for lubricant layers and for model studies of lubrication because of their strong adsorption to the surface. The recent interest on the properties of LB films and SAMs has been also motivated by their potential applications in sensors, non-linear optical devices, lithography and microelectronics. Using the micro-contact printing method the authors prepared patterned SAMs consisting of methyl-terminated alkanethiols of different chain lengths. The samples were characterized using lateral force microscopy (LFM) and the force modulation technique (FMT). In general, higher friction is observed over the short chain regions than over the long chain regions when a low or moderate load is applied to the SFM tip. For such cases the high friction (short chain) regions are also ``softer`` as measured by FMT. A high loads, a reversal of the image contrast is observed and the short chain regions show a lower friction than the long chain regions. This image contrast is reversible upon reduction of the applied load.

  4. Numerical study of forced convective heat transfer around airships

    Science.gov (United States)

    Dai, Qiumin; Fang, Xiande

    2016-02-01

    Forced convective heat transfer is an important factor that affects the thermal characteristics of airships. In this paper, the steady state forced convective heat transfer around an ellipsoid is numerically investigated. The numerical simulation is carried out by commercial computational fluid dynamic (CFD) software over the extended Re range from 20 to 108 and the aspect ratio from 2 to 4. Based on the regression and optimization with software, a new piecewise correlation of the Nusselt number at constant wall temperature for ellipsoid is proposed, which is suitable for applications to airships and other ellipse shaped bodies such as elliptical balloons. The thermal characteristics of a stratospheric airship in midsummer located in the north hemisphere are numerical studied. The helium temperature predicated using the new correlation is compared to those predicted by correlations applicable for spheres and flat plates. The results show that the helium temperature obtained using the new correlation at noon is about 5.4 K lower than that using the correlation of spheres and about 2.1 K higher than that of flat plates.

  5. Nanomechanics of Cells and Biomaterials Studied by Atomic Force Microscopy.

    Science.gov (United States)

    Kilpatrick, Jason I; Revenko, Irène; Rodriguez, Brian J

    2015-11-18

    The behavior and mechanical properties of cells are strongly dependent on the biochemical and biomechanical properties of their microenvironment. Thus, understanding the mechanical properties of cells, extracellular matrices, and biomaterials is key to understanding cell function and to develop new materials with tailored mechanical properties for tissue engineering and regenerative medicine applications. Atomic force microscopy (AFM) has emerged as an indispensable technique for measuring the mechanical properties of biomaterials and cells with high spatial resolution and force sensitivity within physiologically relevant environments and timescales in the kPa to GPa elastic modulus range. The growing interest in this field of bionanomechanics has been accompanied by an expanding array of models to describe the complexity of indentation of hierarchical biological samples. Furthermore, the integration of AFM with optical microscopy techniques has further opened the door to a wide range of mechanotransduction studies. In recent years, new multidimensional and multiharmonic AFM approaches for mapping mechanical properties have been developed, which allow the rapid determination of, for example, cell elasticity. This Progress Report provides an introduction and practical guide to making AFM-based nanomechanical measurements of cells and surfaces for tissue engineering applications.

  6. History of the Army Ground Forces. Study Number 27. History of the Armored Force, Command and Center

    Science.gov (United States)

    1946-01-01

    At.ten degrees farenheit , the turret seo- tion was not sufficiently heated although the other compartments were satisfactorily i4U.j? heated. The Board... 451 ADR (AFRTC) (M) 29 Dec 42. G-3 files 353/9. 39. Memo of ExO OD&T to Hist Off, 19 Sep 45. Hist Off files. 40. Ltr Gen Scott to CG R&SC, 28 Mar 44

  7. Atmospheric aerosol radiative forcing over a semi-continental location Tripura in North-East India: Model results and ground observations.

    Science.gov (United States)

    Dhar, Pranab; De, Barin Kumar; Banik, Trisanu; Gogoi, Mukunda M; Babu, S Suresh; Guha, Anirban

    2017-02-15

    Northeast India (NEI) is located within the boundary of the great Himalayas in the north and the Bay of Bengal (BoB) in the southwest, experiences the mixed influence of the westerly dust advection from the Indian desert, anthropogenic aerosols from the highly polluted Indo-Gangetic Plains (IGP) and marine aerosols from BoB. The present study deals with the estimation and characterization of aerosol radiative forcing over a semi-continental site Tripura, which is a strategic location in the western part of NEI having close proximity to the outflow of the IGP. Continuous long term measurements of aerosol black carbon (BC) mass concentrations and columnar aerosol optical depth (AOD) are used for the estimation of aerosol radiative forcing in each monthly time scale. The study revealed that the surface forcing due to aerosols was higher during both winter and pre-monsoon seasons, having comparable values of 32W/m(2) and 33.45W/m(2) respectively. The atmospheric forcing was also higher during these months due to increased columnar aerosol loadings (higher AOD ~0.71) shared by abundant BC concentrations (SSA ~0.7); while atmospheric forcing decreased in monsoon due to reduced magnitude of BC (SSA ~0.94 in July) as well as columnar AOD. The top of the atmosphere (TOA) forcing is positive in pre-monsoon and monsoon months with the highest positive value of 3.78W/m(2) in June 2012. The results are discussed in light of seasonal source impact and transport pathways from adjacent regions.

  8. Study of mine stability using records of ground tilting

    CSIR Research Space (South Africa)

    Spottiswoode, SM

    2006-06-01

    Full Text Available to estimate tilting from mining, assuming elastic rock mass behaviour. Some suggestions for further work are made. These include studying changes in a seismic tilting following tilt events associated with shrinking pillars. This might provide more direct...

  9. Study on cogging force of permanent magnet linear synchronous motor

    Institute of Scientific and Technical Information of China (English)

    SHANGGUAN Xuan-feng; YUAN Shi-ying; LI Qing-fu

    2005-01-01

    Presented the methods to obtain the cogging force of permanent magnet linear synchronous motors(PMLSMs), analyzed the characteristics of the cogging force,and provided a basis for reducing the effect of the cogging force. 2-dimensional finite element method(2D FEM) was used to solve the whole motor when its mover was at different position, so that the relation was derived between the cogging force and the mover position. The analysis results show that the cogging force between the two ends of the primary iron-core and the secondary permanent magnets (PMs) is sinusoidal function of the mover position under certain conditions only. Two proposed methods,namely direct and indirect methods, are applied to calculate the cogging force between the primary iron-core teeth and the secondary PMs. The agreement of the two methods is validated.

  10. Effect of head and neck position on vertical ground reaction forces and interlimb coordination in the dressage horse ridden at walk and trot on a treadmill.

    Science.gov (United States)

    Weishaupt, M A; Wiestner, T; von Peinen, K; Waldern, N; Roepstorff, L; van Weeren, R; Meyer, H; Johnston, C

    2006-08-01

    Little is known in quantitative terms about the influence of different head-neck positions (HNPs) on the loading pattern of the locomotor apparatus. Therefore it is difficult to predict whether a specific riding technique is beneficial for the horse or if it may increase the risk for injury. To improve the understanding of forelimb-hindlimb balance and its underlying temporal changes in relation to different head and neck positions. Vertical ground reaction force and time parameters of each limb were measured in 7 high level dressage horses while being ridden at walk and trot on an instrumented treadmill in 6 predetermined HNPs: HNP1 - free, unrestrained with loose reins; HNP2 - neck raised, bridge of the nose in front of the vertical; HNP3 - neck raised, bridge of the nose behind the vertical; HNP4 - neck lowered and flexed, bridge of the nose considerably behind the vertical; HNP5 - neck extremely elevated and bridge of the nose considerably in front of the vertical; HNP6 - neck and head extended forward and downward. Positions were judged by a qualified dressage judge. HNPs were assessed by comparing the data to a velocity-matched reference HNP (HNP2). Differences were tested using paired t test or Wilcoxon signed rank test (Pwalk, stride duration and overreach distance increased in HNP1, but decreased in HNP3 and HNP5. Stride impulse was shifted to the forehand in HNP1 and HNP6, but shifted to the hindquarters in HNP5. At the trot, stride duration increased in HNP4 and HNP5. Overreach distance was shorter in HNP4. Stride impulse shifted to the hindquarters in HNP5. In HNP1 peak forces decreased in the forelimbs; in HNP5 peak forces increased in fore- and hindlimbs. HNP5 had the biggest impact on limb timing and load distribution and behaved inversely to HNP1 and HNP6. Shortening of forelimb stance duration in HNP5 increased peak forces although the percentage of stride impulse carried by the forelimbs decreased. An extremely high HNP affects functionality much

  11. Assessment of Simulated Ground Motions in Earthquake Engineering Practice: A Case Study for Duzce (Turkey)

    Science.gov (United States)

    Karimzadeh, Shaghayegh; Askan, Aysegul; Yakut, Ahmet

    2017-07-01

    Simulated ground motions can be used in structural and earthquake engineering practice as an alternative to or to augment the real ground motion data sets. Common engineering applications of simulated motions are linear and nonlinear time history analyses of building structures, where full acceleration records are necessary. Before using simulated ground motions in such applications, it is important to assess those in terms of their frequency and amplitude content as well as their match with the corresponding real records. In this study, a framework is outlined for assessment of simulated ground motions in terms of their use in structural engineering. Misfit criteria are determined for both ground motion parameters and structural response by comparing the simulated values against the corresponding real values. For this purpose, as a case study, the 12 November 1999 Duzce earthquake is simulated using stochastic finite-fault methodology. Simulated records are employed for time history analyses of frame models of typical residential buildings. Next, the relationships between ground motion misfits and structural response misfits are studied. Results show that the seismological misfits around the fundamental period of selected buildings determine the accuracy of the simulated responses in terms of their agreement with the observed responses.

  12. Detailed Study of Amplitude Nonlinearity in Piezoresistive Force Sensors

    OpenAIRE

    Pablo Gonzalez De Santos; Elena Garcia; Luis Emmi; Leonel Paredes-Madrid

    2011-01-01

    This article upgrades the RC linear model presented for piezoresistive force sensors. Amplitude nonlinearity is found in sensor conductance, and a characteristic equation is formulated for modeling its response under DC-driving voltages below 1 V. The feasibility of such equation is tested on four FlexiForce model A201-100 piezoresistive sensors by varying the sourcing voltage and the applied forces. Since the characteristic equation proves to be valid, a method is presented for obtaining a s...

  13. Microfluidic traction force microscopy to study mechanotransduction in angiogenesis.

    Science.gov (United States)

    Boldock, Luke; Wittkowske, Claudia; Perrault, Cecile M

    2017-07-01

    The formation of new blood vessels from existing vasculature, angiogenesis, is driven by coordinated endothelial cell migration and matrix remodeling in response to local signals. Recently, a growing body of evidence has shown that mechanotransduction, along with chemotransduction, is a major regulator of angiogenesis. Mechanical signals, such as fluid shear stress and substrate mechanics, influence sprouting and network formation, but the mechanisms behind this relationship are still unclear. Here, we present cellular traction forces as possible effectors activated by mechanosensing to mediate matrix remodeling, and encourage the use of TFM to study mechanotransduction in angiogenesis. We also suggest that deciphering the response of EC to mechanical signals could reveal an optimal angiogenic mechanical environment, and provide insight into development, wound healing, the initiation and growth of tumors, and new strategies for tissue engineering. © 2017 John Wiley & Sons Ltd.

  14. Effects of Ground Motion Input on the Derived Fragility Functions: Case study of 2010 Haiti Earthquake

    Science.gov (United States)

    Hancilar, Ufuk; Harmandar, Ebru; Çakti, Eser

    2014-05-01

    Empirical fragility functions are derived by statistical processing of the data on: i) Damaged and undamaged buildings, and ii) Ground motion intensity values at the buildings' locations. This study investigates effects of different ground motion inputs on the derived fragility functions. The previously constructed fragility curves (Hancilar et al. 2013), which rely on specific shaking intensity maps published by the USGS after the 2010 Haiti Earthquake, are compared with the fragility functions computed in the present study. Building data come from field surveys of 6,347 buildings that are grouped with respect to structural material type and number of stories. For damage assessment, the European Macroseismic Scale (EMS-98) damage grades are adopted. The simplest way to account for the variability in ground motion input could have been achieved by employing different ground motion prediction equations (GMPEs) and their standard variations. However, in this work, we prefer to rely on stochastically simulated ground motions of the Haiti earthquake. We employ five different source models available in the literature and calculate the resulting strong ground motion in time domain. In our simulations we also consider the local site effects by published studies on NEHRP site classes and micro-zoning maps of the city of Port-au-Prince. We estimate the regional distributions from the waveforms simulated at the same coordinates that we have damage information from. The estimated spatial distributions of peak ground accelerations and velocities, PGA and PGV respectively, are then used as input to fragility computations. The results show that changing the ground motion input causes significant variability in the resulting fragility functions.

  15. Influence of foundation type and soil stratification on ground vibration - a parameter study

    DEFF Research Database (Denmark)

    Andersen, Lars Vabbersgaard; Prins, Joeri Nithan; Persson, Kent

    2016-01-01

    Vibration of machinery and construction work are major sources of noise and vibration pollution in the urban environment. The frequencies dominating the vibration, and the distances over which it spreads via the ground, depend on the source. However, soil stratification and foundation type have...... a significant influence. Thus, in order to achieve fair accuracy in the prediction of ground vibration caused by sources vibrating on a foundation, accurate models of the ground and foundation may be required. However, for assessment of vibration in the design phase, simple models may be preferred. The paper...... provides a parameter study regarding the influence of soil stratification and foundation type on the ground vibration at different distances away from the source. Especially, vibration levels caused by sources placed on surface footings and piles are compared, employing a three-dimensional numerical model...

  16. Correlation study between ground motion intensity measure parameters and deformation demands for bilinear SDOF systems

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The correlation between ground motion intensity measures (IM) and single-degree-of-freedom (SDOF) deformation demands is described in this study. Peak ground acceleration (APG), peak ground velocity (VPG), peak ground displacement (DPG), spectral acceleration at the first-mode period of vibration [As(T1)] and ratio of VPG to APG are used as IM parameters, and the correlation is characterized by correlation coefficients ρ. The numerical results obtained by nonlinear dynamic analyses have shown good correlation between As(T1) or VPG and deformation demands. Furthermore, the effect of As(T1) and VPG as IM on the dispersion of the mean value of deformation demands is also investigated for SDOF systems with three different periods T=0.3 s, 1.0 s, 3.0 s respectively.

  17. Precision study of ground state capture in the 14N(p,gamma)15O reaction

    CERN Document Server

    Marta, M; Gyurky, Gy; Bemmerer, D; Broggini, C; Caciolli, A; Corvisiero, P; Costantini, H; Elekes, Z; Fülöp, Z; Gervino, G; Guglielmetti, A; Gustavino, C; Imbriani, G; Junker, M; Kunz, R; Lemut, A; Limata, B; Mazzocchi, C; Menegazzo, R; Prati, P; Roca, V; Rolfs, C; Romano, M; Alvarez, C Rossi; Somorjai, E; Straniero, O; Strieder, F; Terrasi, F; Trautvetter, H P; Vomiero, A

    2008-01-01

    The rate of the hydrogen-burning carbon-nitrogen-oxygen (CNO) cycle is controlled by the slowest process, 14N(p,gamma)15O, which proceeds by capture to the ground and several excited states in 15O. Previous extrapolations for the ground state contribution disagreed by a factor 2, corresponding to 15% uncertainty in the total astrophysical S-factor. At the Laboratory for Underground Nuclear Astrophysics (LUNA) 400 kV accelerator placed deep underground in the Gran Sasso facility in Italy, a new experiment on ground state capture has been carried out at 317.8, 334.4, and 353.3 keV center-of-mass energy. Systematic corrections have been reduced considerably with respect to previous studies by using a Clover detector and by adopting a relative analysis. The previous discrepancy has been resolved, and ground state capture no longer dominates the uncertainty of the total S-factor.

  18. Task Force Report on Social Studies Education in Maryland: The Challenge and the Imperative

    Science.gov (United States)

    Maryland State Department of Education, 2010

    2010-01-01

    In November 2004, State Superintendent of Schools Nancy S. Grasmick convened the Maryland Social Studies Task Force. The Task Force was charged with examining issues related to social studies education and recommending ways to improve social studies instruction in Maryland's public schools. The Task Force formed four Subcommittees, each examining…

  19. Applicability of Performance Assessment Tools to Marine Corps Air Ground Task Force C4 System of Systems Performance Assessment

    Science.gov (United States)

    2010-09-01

    Fiebrandt & Dryer , 2009, p. 3). The six steps of the CTM provide a basic framework for any SoS evaluation. Outlined in JTEM’s Action Officer’s...commercial software tools such as Solar Winds’ Orion Network Performance Monitor associated with the Joint Network Management System (JNMS) program of...and virtualization technology may help expedite this effort. Finally, virtualization technology may serve as a fruitful area of study from two

  20. Ground Reaction Force and Mechanical Differences Between the Interim Resistive Exercise Device (iRED) and Smith Machine While Performing a Squat

    Science.gov (United States)

    Amonette, William E.; Bentley, Jason R.; Lee, Stuart M. C.; Loehr, James A.; Schneider, Suzanne

    2004-01-01

    Musculoskeletal unloading in microgravity has been shown to induce losses in bone mineral density, muscle cross-sectional area, and muscle strength. Currently, an Interim Resistive Exercise Device (iRED) is being flown on board the ISS to help counteract these losses. Free weight training has shown successful positive musculoskeletal adaptations. In biomechanical research, ground reaction forces (GRF) trajectories are used to define differences between exercise devices. The purpose of this evaluation is to quantify the differences in GRF between the iRED and free weight exercise performed on a Smith machine during a squat. Due to the differences in resistance properties, inertial loading and load application to the body between the two devices, we hypothesize that subjects using iRED will produce GRF that are significantly different from the Smith machine. There will be differences in bar/harness range of motion and the time when peak GRF occurred in the ROMbar. Three male subjects performed three sets of ten squats on the iRED and on the Smith Machine on two separate days at a 2-second cadence. Statistically significant differences were found between the two devices in all measured GRF variables. Average Fz and Fx during the Smith machine squat were significantly higher than iRED. Average Fy (16.82 plus or minus.23; p less than .043) was significantly lower during the Smith machine squat. The mean descent/ascent ratio of the magnitude of the resultant force vector of all three axes for the Smith machine and iRED was 0.95 and 0.72, respectively. Also, the point at which maximum Fz occurred in the range of motion (Dzpeak) was at different locations with the two devices.

  1. Opportunizing: A classic grounded theory study on business and management

    Directory of Open Access Journals (Sweden)

    Ólavur Christiansen

    2006-11-01

    Full Text Available Opportunizing emerged as the core variable of this classic GT study on business and management. Opportunizing is the recurrent main concern that businesses have to continually resolve, and it explains how companies recurrently create, identify, seize or exploit situations to maintain their growth or survival. Opportunizing is the recurrent creation and re-creation of opportunities in business. Opportunizing is basically what business managers do and do all the time. The problematic nature of opportunizing is resolved by a core social process ofopportunizing and its attached sub-processes that account for change over time and for the variations of the problematic nature of its resolution.Opportunizing has five main facets. These are conditional befriending (confidence building & modifying behavior,prospecting (e.g. information gaining, weighing up (information appraisal & decision-making, moment capturing (quick intervention for seizing strategic opportunities, andconfiguration matching (adjusting the business organization to abet the other activities of opportunizing.On a more abstract level, opportunizing has three more organizational facets: the physically boundary-less, the valuehierarchical, and the physically bounded. The first of these called perpetual opportunizing. This emerges from the conjunction of conditional befriending and prospecting. The second facet is called triggering opportunizing. It arises from the coming together of weighing up and moment capturing. The final facet is called spasmodic opportunizing. This happens when moment capturing and configuration matching unite.

  2. Novel Bioreactors to Study Forces on Bronchial Epithelial Cultures

    Science.gov (United States)

    Carpenter, Jerome; Millard, Mike; Cozon, Matthew; Superfine, Richard

    2008-10-01

    Studying cells in a physiologically relevant environment is an important tool in understanding cell signaling and gene expression. Human bronchial epithelial cells (HBECs) are responsible for mucociliary clearance, which removes pathogens from the air we breathe. Recreating the in vivo conditions of HBECs is difficult; they are polarized and undergo a variety of forces. Polarization is required for organ-specific systems such as cilia motility and mucus regulation. We achieve polarization by growing cells on an electrospun nanoporous scaffold which we attach to a silastic annulus. Using this geometry we apply vacuum to the annulus and stretch the cells. This bioreactor allows us to study polarized HBECs as they experience cyclic strain similar to breathing. We've grown polarized cultures on the scaffold and are evaluating the scaffold's mechanical properties. In a second bioreactor, we place the scaffold into a microfluidics channel to study the affect of shear stress on polarized cells. We also reproduce the branching structure found in the lungs to investigate the regulation of mucus as it ascends the airway tree.

  3. Leading Critically: A Grounded Theory of Applied Critical Thinking in Leadership Studies

    Science.gov (United States)

    Jekins, Daniel M.; Cutchens, Amanda B.

    2011-01-01

    This study describes the development of a grounded theory of applied critical thinking in leadership studies and examines how student-centered experiential learning in leadership education bridged critical thinking with action. Over three semester undergraduate students in an upper level leadership studies course at a large four-year public…

  4. Leading Critically: A Grounded Theory of Applied Critical Thinking in Leadership Studies

    Science.gov (United States)

    Jekins, Daniel M.; Cutchens, Amanda B.

    2011-01-01

    This study describes the development of a grounded theory of applied critical thinking in leadership studies and examines how student-centered experiential learning in leadership education bridged critical thinking with action. Over three semester undergraduate students in an upper level leadership studies course at a large four-year public…

  5. Comparative study on the microorganisms present in ground meat in supermarkets and local markets in Ecatepec

    Directory of Open Access Journals (Sweden)

    Adriana Rosales-Garnica

    2011-06-01

    Full Text Available Meat is one of the most perishable foods due to that are high in the water and nutrients that promotes the growth of microorganisms. Ground meat tends to have more contamination than fresh meat because of the milling process where the microorganisms that were polluting the inside surface. Five stores were sampled from a supermarket chain and five markets in the municipality of Ecatepec. Ground beef was used for analysis of aerobic plate counts, total coliforms, Staphylococcos, fungi and yeasts. The results show that aerobic mesophilic count is within the limits of the Standard (NOM-092-SSA1-1994, the amount of Staphylococcos exceeds the Standard in the markets but within the limits of the Standard in supermarkets, coliforms and molds and yeasts are present in markets and supermarkets but are not considered in the Standard. We conclude that ground beef is sold in markets and supermarkets in the municipality of Ecatepec has lots of coliforms and Staphylococcos, which are responsible for many toxic infections. It is necessary to update the regulations in force, to be given greater monitoring.

  6. Influence of different head-neck positions on vertical ground reaction forces, linear and time parameters in the unridden horse walking and trotting on a treadmill.

    Science.gov (United States)

    Waldern, N M; Wiestner, T; von Peinen, K; Gómez Alvarez, C G; Roepstorff, L; Johnston, C; Meyer, H; Weishaupt, M A

    2009-03-01

    It is believed that the head-neck position (HNP) has specific effects on the loading pattern of the equine locomotor system, but very few quantitative data are available. To quantify the effects of 6 different HNPs on forelimb-hindlimb loading and underlying temporal changes. Vertical ground reaction forces of each limb and interlimb coordination were measured in 7 high level dressage horses walking and trotting on an instrumented treadmill in 6 predetermined HNPs: HNP1--unrestrained; HNP2--elevated neck, bridge of the nose in front of the vertical; HNP3--elevated neck, bridge of the nose behind the vertical; HNP4--low and flexed neck; HNP5--head and neck in extreme high position; and HNP6--forward downward extension of head and neck. HNP1 served as a velocity-matched control. At the walk, the percentage of vertical stride impulse carried by the forehand (Iz(fore)) as well as stride length and overreach distance were decreased in HNP2, HNP3, HNP4 and HNP5 when compared to HNP1. At the trot, Iz(fore) was decreased in HNP2, HNP3, HNP4 and HNP5. Peak forces in the forelimbs increased in HNP5 and decreased in HNP6. Stance duration in the forelimbs was decreased in HNP2 and HNP5. Suspension duration was increased in HNP2, HNP3 and HNP5. Overreach distance was shorter in HNP4 and longer in HNP6. In comparison to HNP1 and HNP6, HNPs with elevation of the neck with either flexion or extension at the poll as well as a low and flexed head and neck lead to a weight shift from the forehand to the hindquarters. HNP5 had the biggest effect on limb timing and load distribution. At the trot, shortening of forelimb stance duration in HNP5 increased peak vertical forces although Iz(fore) decreased. Presented results contribute to the understanding of the value of certain HNPs in horse training.

  7. Procedures for addressing uncertainty and variability in exposure to characterize potential health risk from trichloroethylene contaminated ground water at Beale Air Force Base in California

    Energy Technology Data Exchange (ETDEWEB)

    Daniels, J I; Bogen, K T; Hall, L C

    1999-10-05

    Conservative deterministic, screening-level calculations of exposure and risk commonly are used in quantitative assessments of potential human-health consequences from contaminants in environmental media. However, these calculations generally are based on multiple upper-bound point estimates of input parameters, particularly for exposure attributes, and can therefore produce results for decision makers that actually overstate the need for costly remediation. Alternatively, a more informative and quantitative characterization of health risk can be obtained by quantifying uncertainty and variability in exposure. This process is illustrated in this report for a hypothetical population at a specific site at Beale Air Force Base in California, where there is trichloroethylene (TCE) contaminated ground water and a potential for future residential use. When uncertainty and variability in exposure were addressed jointly for this case, the 95th-percentile upper-bound value of individual excess lifetime cancer risk was a factor approaching 10 lower than the most conservative deterministic estimate. Additionally, the probability of more than zero additional cases of cancer can be estimated, and in this case it is less than 0.5 for a hypothetical future residential population of up to 26,900 individuals present for any 7.6-y interval of a 70-y time period. Clearly, the results from application of this probabilistic approach can provide reasonable and equitable risk-acceptability criteria for a contaminated site.

  8. History of the Army Ground Forces. Study Number 25. The Airborne Command and Center

    Science.gov (United States)

    1946-01-01

    installation of external racks, voicing the opinion that the suspension of bundl,.3 from external racks would mterially affect the flying...fouled the suspension lines of parachutes, resulting in injury to the parachutist, and that the conbat boot was inferior to the parachute boot for field...and the Cushman Scooter . The product finally standardized was known as the Motorcycle, Solo, Extra Light. Development by the Indian Motorcycle Copany

  9. A History of the Army Ground Forces; Study Number 29. The Tank Destroyer History

    Science.gov (United States)

    1946-01-01

    bove, was nore particularly directed to the second and third missiona. Temporary offices were astabli;hed in varioue buildings in the Temple busi ... familtes in the area, many of them representing four generations, were somewhat dazod when oconronted, in Jawmary with the fact, first: that their land

  10. History of the Army Ground Forces. Study Number 12. The Building and Training of Infantry Divisions

    Science.gov (United States)

    1946-01-01

    coenande.s, for the March divi- sions, was the subject of a pungent letter from 1eeral ’arshall to General Lear in xhich The Chief of Staff said: "I have...sight, sound, and sensation of battle,". and to train him "tp act calmly with sound judgent regardless of noise, confusion, and surprise," The

  11. Single-molecule force spectroscopy studies of fibrin 'A-a' polymerization interactions via the atomic force microscope

    Science.gov (United States)

    Averett, Laurel E.

    Fibrin, the polymerized form of the soluble plasma protein fibrinogen, plays a critical role in hemostasis as the structural scaffold of blood clots. The primary functions of fibrin are to withstand the shear forces of blood flow and provide mechanical stability to the clot, protecting the wound. While studies have investigated the mechanical properties of fibrin constructs, the response to force of critical polymerization interactions such as the 'A--a' knob--hole interaction remains unclear. Herein, the response of the 'A--a' bond to force was examined at the single-molecule level using the atomic force microscope. Force spectroscopy methodology was developed to examine the 'A--a' interaction while reducing the incidence of both nonspecific and multiple molecule interactions. The rupture of this interaction resulted in a previously unreported characteristic force profile comprised of up to four events. We hypothesized that the first event represented reorientation of the fibrinogen molecule, the second and third represented unfolding of structures in the D region of fibrinogen, and the last event was the rupture of the 'A--a' bond weakened by prior structural unfolding. The configuration, molecular extension, and kinetic parameters of each event in the characteristic pattern were examined to compare the unfolding of fibrin to other proteins unfolded by force. Fitting the pattern with polymer models showed that the D region of fibrinogen could lengthen by ˜50% of the length of a fibrin monomer before rupture of the 'A--a' bond. Analysis showed that the second and third events had kinetic parameters similar to other protein structures unfolded by force. Studies of the dependence of the characteristic pattern on calcium, concentration of sodium chloride, pH, and temperature demonstrated that the incidence of the last event was affected by solution conditions. However, only low pH and high temperatures reduced the probability that an interaction was characteristic

  12. Atomic force microscopy study of biaxially oriented polypropylene films

    Science.gov (United States)

    Nie, H.-Y.; Walzak, M. J.; McIntyre, N. S.

    2004-08-01

    Atomic force microscopy (AFM) uses a very sharp pointed mechanical probe to collect real-space morphological information of solid surfaces. AFM was used in this study to image the surface morphology of a biaxially oriented polypropylene film. The polymer film is characterized by a nanometer-scale, fiberlike network structure, which reflects the drawing process used during the fabrication of the film. AFM was used to study polymer-surface treatment to improve wettability by exposing the polymer to ozone with or without ultraviolet (UV) irradiation. Surface-morphology changes observed by AFM are the result of the surface oxidation induced by the treatment. Due to the topographic features of the polymer film, the fiberlike structure has been used to check the performance of the AFM tip. An AFM image is a mixture of the surface morphology and the shape of the AFM tip. Therefore, it is important to check the performance of a tip to ensure that the AFM image collected reflects the true surface features of the sample, rather than contamination on the AFM tip.

  13. Polyelectrolyte brushes in mixed ionic medium studied via intermolecular forces

    Science.gov (United States)

    Farina, Robert; Laugel, Nicolas; Pincus, Philip; Tirrell, Matthew

    2011-03-01

    The vast uses and applications of polyelectrolyte brushes make them an attractive field of research especially with the growing interest in responsive materials. Polymers which respond via changes in temperature, pH, and ionic strength are increasingly being used for applications in drug delivery, chemical gating, etc. When polyelectrolyte brushes are found in either nature (e.g., surfaces of cartilage and mammalian lung interiors) or commercially (e.g., skin care products, shampoo, and surfaces of medical devices) they are always surrounded by mixed ionic medium. This makes the study of these brushes in varying ionic environments extremely relevant for both current and future potential applications. The polyelectrolyte brushes in this work are diblock co-polymers of poly-styrene sulfonate (N=420) and poly-t-butyl styrene (N=20) which tethers to a hydrophobic surface allowing for a purely thermodynamic study of the polyelectrolyte chains. Intermolecular forces between two brushes are measured using the SFA. As multi-valent concentrations are increased, the brushes collapse internally and form strong adhesion between one another after contact (properties not seen in a purely mono-valent environment).

  14. An Experimental and Computational Study of Breaking Wave Impact Forces

    CERN Document Server

    Fu, Thomas C; Brewton, Susan; Brucker, Kyle A; Dommermuth, Douglas G

    2014-01-01

    The impact forces generated by the impact of a breaking wave are poorly understood. These impulsive hydrodynamic loads to a ship's hull are of short duration relative to ship motions and buoyant wave loads and often result in extremely high pressures. The physics of breaking waves is a poorly understood, complex, multiphase phenomenon involving violent jet sprays, strong free-surface turbulence, air entrainment and bubble generation, all of which interact with the flow field and the adjacent structure. This paper will describe a set of experiments that were performed, at the Naval Surface Warfare Center, Carderock Division (NSWCCD), in 2006, to measure the hydrodynamic loads of regular nonbreaking and focused breaking waves on a 0.305 m x 0.305 m (1.0 ft x 1.0 ft) square plate and discuss the results of this study. The paper will also discuss Computational Fluid Dynamics (CFD) code predictions of breaking waves and wave impact loads. The CFD code utilized in this study is Numerical Flow Analysis (NFA).

  15. Ground Forces Modernization in China.

    Science.gov (United States)

    1987-08-11

    Soviets reasserted control in Manchuria , as far south as the old Chinese Eastern Railway line (Tsitsihar- Harbin -Vladivostock), they could cripple much...of China’s capability to challenge {. Soviet control of all of Manchuria . Because there is very little defensible terrain between Manchuria and the...Yangtze River, a Soviet conquest of Manchuria would effectively destroy Chinese military power throughout northern China and give the Soviet Union

  16. A numerical study of momentum and forced convection heat transfer ...

    African Journals Online (AJOL)

    temperature fields, axial velocity profiles, local and average Nusselt numbers, and skin frictions were ... Key words: Finite volume method - Turbulent flow - Forced convection - Waved baffles. .... numerical simulations are conducted in a two-.

  17. STUDY OF HYDRODYNAMIC FORCES OF SHIPS IN NARROW WATERWAY

    Institute of Scientific and Technical Information of China (English)

    Zhang Xie-dong; Wu Xiu-heng

    2003-01-01

    The collision of ships in narrow waterway may occur for a variety of reasons. The hydrodynamic forces between two ships change the maneuvering characteristics of ships greatly. So based on the boundary element method, this paper proposes a calculation method for hydrodynamic interaction forces between ships under meeting and passing conditions in narrow waterway. The results from this method are compared with the existing results obtained from other theoretical approaches, and they are in good agreement.

  18. Discovering Shared Experiences of Second Generation Community College Employees: A Grounded Theory Study

    Science.gov (United States)

    Studebaker, Eric J.

    2012-01-01

    The second generation community college employee had not been a target population of any previous research in the field of higher education. This study added to a broader understanding of employees, their various characteristics, and the implications of those characteristics. The purpose of this study was to develop a grounded theory defining the…

  19. The Role of Professional School Counselors in Working with Students in Gangs: A Grounded Theory Study

    Science.gov (United States)

    Barrow, Jennifer Cahoon

    2011-01-01

    The purpose of this study was to propose a grounded theory that contributed to the understanding of the professional school counselor's role at the secondary school level in working with students in gangs. The study explored the role of the professional school counselor from the first person perspective of the professional school counselor and…

  20. Exploring Attitude Transformation: A Grounded Theory Study of Romanian Teachers of Roma Students

    Science.gov (United States)

    Jones, Laura Estella

    2016-01-01

    The purpose of this systematic grounded theory study was to explore the process of change in teacher attitudes toward including Roma ("Gypsy") students in non-segregated schools in Romania. The theories guiding this study included Mezirow's (1991, 2000) theory of transformation, Gay's (2002, 2013) theory of culturally responsive…

  1. A Grounded Theory Study of Effective Global Leadership Development Strategies: Perspectives from Brazil, India, and Nigeria

    Science.gov (United States)

    Lokkesmoe, Karen Jane

    2009-01-01

    This qualitative, grounded theory study focuses on global leadership and global leadership development strategies from the perspective of people from three developing countries, Brazil, India, and Nigeria. The study explores conceptualizations of global leadership, the skills required to lead effectively in global contexts, and recommended…

  2. Exploring Attitude Transformation: A Grounded Theory Study of Romanian Teachers of Roma Students

    Science.gov (United States)

    Jones, Laura Estella

    2016-01-01

    The purpose of this systematic grounded theory study was to explore the process of change in teacher attitudes toward including Roma ("Gypsy") students in non-segregated schools in Romania. The theories guiding this study included Mezirow's (1991, 2000) theory of transformation, Gay's (2002, 2013) theory of culturally responsive…

  3. Sitewide feasibility study Eielson Air Force Base, Alaska

    Energy Technology Data Exchange (ETDEWEB)

    Last, G.V.; Lanigan, D.C.; Josephson, G.B.; Bagaasen, L.M.

    1995-09-01

    The Sitewide Feasibility Study (FS) is required under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), the National Contingency Plan (NCP), and the Federal Facility Agreement (FFA) for Eielson Air Force Base (AFB). It is based on findings presented in the Sitewide Remedial Investigation (RI) Report (USAF 1995a), and the Sitewide Baseline Risk Assessment (BLRA) Report (USAF 1995b). Under the FFA, 64 potential source areas were placed in one of six operable units, based on similar contaminant and environmental characteristics, or were included for evaluation under a Source Evaluation Report (SER). The sitewide RI was directed at contamination that was not confined to an operable unit (OU) or SER source area. The objectives of the sitewide RI were to: Provide information about site characteristics to support individual OU RI/FS efforts and the sitewide RI/FS, including site hydrogeology and determination of background soil and groundwater characteristics; identify and characterize contamination that is not confined or attributable to a specific source area through sitewide monitoring of groundwater and surface water; evaluate cumulative risks to human health and the environment from contamination on a sitewide basis; and provide a mechanism for continued cohesive sitewide monitoring.

  4. A comparative study of satellite estimation for solar insolation in Albania with ground measurements

    Energy Technology Data Exchange (ETDEWEB)

    Mitrushi, Driada, E-mail: driadamitrushi@yahoo.com; Berberi, Pëllumb, E-mail: pellumb.berberi@gmail.com; Muda, Valbona, E-mail: vmuda@hotmail.com; Buzra, Urim, E-mail: rimibuzra@yahoo.com [Department of Engineering Physics, Faculty of Engineering Mathematics and Engineering Physics, Polytechnic University of Tirana, Tirana (Albania); Bërdufi, Irma, E-mail: irmaberdufi@gmail.com [Institute of Applied Nuclear Physics, Tirana University, Street “Th. Filipeu”, Tirana (Albania); Topçiu, Daniela, E-mail: topciudaniela@yahoo.com [Department of Physics, Faculty of Natural Physics, “Aleksander Xhuvani” University, Elbasan (Albania)

    2016-03-25

    The main objective of this study is to compare data provided by Database of NASA with available ground data for regions covered by national meteorological net NASA estimates that their measurements of average daily solar radiation have a root-mean-square deviation RMSD error of 35 W/m{sup 2} (roughly 20% inaccuracy). Unfortunately valid data from meteorological stations for regions of interest are quite rare in Albania. In these cases, use of Solar Radiation Database of NASA would be a satisfactory solution for different case studies. Using a statistical method allows to determine most probable margins between to sources of data. Comparison of mean insulation data provided by NASA with ground data of mean insulation provided by meteorological stations show that ground data for mean insolation results, in all cases, to be underestimated compared with data provided by Database of NASA. Converting factor is 1.149.

  5. A study on the nondestructive test optimum design for a ground tracked combat vehicle

    Energy Technology Data Exchange (ETDEWEB)

    Kim Byeong Ho; Seo, Jae Hyun; Gil, Hyeon Jun [Defence Agency for Technology and Quality, Seoul (Korea, Republic of); Kim, Seon Hyeong [Hanwha Techwin Co.,Ltd., Changwon (Korea, Republic of); Seo, Sang Chul [Changwon National University, Changwon (Korea, Republic of)

    2015-10-15

    In this study, a nondestructive test (NDT) is performed to inspect the optimal design of a ground tracked combat vehicle for self-propelled artillery, tank, and armored vehicles. The minimum qualification required for personnel performing the NDT of a ground tracked combat vehicle was initially established in US military standards, and then applied to the Korean defense specifications to develop a ground tracked combat vehicle. However, the qualification standards of an NDT inspector have been integrated into NAS410 through the military and commercial specifications unification project that were applied in the existing aerospace/defense industry public standard. The design method for this study was verified by applying the optimal design to the liquid penetrant testing Al forging used in self-propelled artillery. This confirmed the reliability and soundness of the product.

  6. The Development of Air Force Undergraduate Space Training. LTTC Special Study.

    Science.gov (United States)

    Levy, Michael H.

    This historical study traces the development of an undergraduate program at Lowry Technical Training Center (LTTC) situated in the Lowry Air Force Base, Colorado, to train Air Force officers and enlisted personnel for the space operations career field. The report begins in the 1950s when Air Force Systems Command examined the concept of a manned…

  7. The study of coastal ground surfaces to predict the ways of increasing efficiency of research mobile robots

    Science.gov (United States)

    Makarov, Vladimir; Kurkin, Andrey; Belyalov, Vladimir; Tyugin, Dmitry; Zezyulin, Denis

    2017-04-01

    The increase in spatial scales of studying coastal areas can be achieved by the use of mobile robotic systems (MRS) equipped with scanning equipment, video inspection system and positioning system. The project aims at increasing the capabilities for designing effective ground MRS through the use of advanced methods of forecasting characteristics of vehicle-terrain interaction in coastal zones, where hydrosphere, lithosphere, atmosphere and biosphere interact. In the period from 14 May to 18 June 2016 there was organized the expedition to Sakhalin Island for conducting full-scale testing autonomous MRS for coastal monitoring and forecasting marine natural disasters [Kurkin A.A., Zeziulin D.V., Makarov V.S., Zaitsev A.I., Belyaev A.M., Beresnev P.O., Belyakov V.V., Pelinovsky E.N., Tyugin D.Yu. Investigations of coastal areas of the Okhotsk sea using a ground mobile robot // Ecological systems and devices. 2016. No. 8. P. 11-17]. Within the framework of the expedition specific areas of terrain in the vicinity of Cape Svobodny were investigated (with the support of SRB AMR FEB RAS). Terrain areas were studied from the standpoint of possibility of the MRS movement. As a result of measuring all the necessary data on the physical-mechanical and geometric characteristics of the coastal zones, required to calculate the force factors acting on the MRS, and, accordingly, the parameters of its motion were received. The obtained data will be used for developing new statistical models of the physical-mechanical and geometrical characteristics of the coastal ground surfaces, creating methodology for assessing the efficiency and finding ways to optimize the design of the MRS.

  8. Pilot Study on the Effect of Grounding on Delayed-Onset Muscle Soreness

    Science.gov (United States)

    Brown, Dick; Hill, Michael

    2010-01-01

    Abstract Objectives The purpose of this pilot study was to determine whether there are markers that can be used to study the effects of grounding on delayed-onset muscle soreness (DOMS). Design and subjects Eight (8) healthy subjects were exposed to an eccentric exercise that caused DOMS in gastrocnemius muscles of both legs. Four (4) subjects were grounded with electrode patches and patented conductive sheets connected to the earth. Four (4) control subjects were treated identically, except that the grounding systems were not connected to the earth. Outcome measures Complete blood counts, blood chemistry, enzyme chemistry, serum and saliva cortisols, magnetic resonance imaging and spectroscopy and pain levels were taken at the same time of day before the eccentric exercise and 24, 48, and 72 hours afterwards. Parameters consistently differing by 10% or more, normalized to baseline, were considered worthy of further study. Results Parameters that differed by these criteria included white blood cell counts, bilirubin, creatine kinase, phosphocreatine/inorganic phosphate ratios, glycerolphosphorylcholine, phosphorylcholine, the visual analogue pain scale, and pressure measurements on the right gastrocnemius. Conclusions In a pilot study, grounding the body to the earth alters measures of immune system activity and pain. Since this is the first intervention that appears to speed recovery from DOMS, the pilot provides a basis for a larger study. PMID:20192911

  9. Ground state atomic oxygen in high-power impulse magnetron sputtering: a quantitative study

    Science.gov (United States)

    Britun, Nikolay; Belosludtsev, Alexandr; Silva, Tiago; Snyders, Rony

    2017-02-01

    The ground state density of oxygen atoms in reactive high-power impulse magnetron sputtering discharges has been studied quantitatively. Both time-resolved and space-resolved measurements were conducted. The measurements were performed using two-photon absorption laser-induced fluorescence (TALIF), and calibrated by optical emission actinometry with multiple Ar emission lines. The results clarify the dynamics of the O ground state atoms in the discharge afterglow significantly, including their propagation and fast decay after the plasma pulse, as well as the influence of gas pressure, O2 admixture, etc.

  10. Detailed Study of Amplitude Nonlinearity in Piezoresistive Force Sensors

    Directory of Open Access Journals (Sweden)

    Pablo Gonzalez De Santos

    2011-09-01

    Full Text Available This article upgrades the RC linear model presented for piezoresistive force sensors. Amplitude nonlinearity is found in sensor conductance, and a characteristic equation is formulated for modeling its response under DC-driving voltages below 1 V. The feasibility of such equation is tested on four FlexiForce model A201-100 piezoresistive sensors by varying the sourcing voltage and the applied forces. Since the characteristic equation proves to be valid, a method is presented for obtaining a specific sensitivity in sensor response by calculating the appropriate sourcing voltage and feedback resistor in the driving circuit; this provides plug-and-play capabilities to the device and reduces the start-up time of new applications where piezoresistive devices are to be used. Finally, a method for bypassing the amplitude nonlinearity is presented with the aim of reading sensor capacitance.

  11. Detailed study of amplitude nonlinearity in piezoresistive force sensors.

    Science.gov (United States)

    Paredes-Madrid, Leonel; Emmi, Luis; Garcia, Elena; de Santos, Pablo Gonzalez

    2011-01-01

    This article upgrades the RC linear model presented for piezoresistive force sensors. Amplitude nonlinearity is found in sensor conductance, and a characteristic equation is formulated for modeling its response under DC-driving voltages below 1 V. The feasibility of such equation is tested on four FlexiForce model A201-100 piezoresistive sensors by varying the sourcing voltage and the applied forces. Since the characteristic equation proves to be valid, a method is presented for obtaining a specific sensitivity in sensor response by calculating the appropriate sourcing voltage and feedback resistor in the driving circuit; this provides plug-and-play capabilities to the device and reduces the start-up time of new applications where piezoresistive devices are to be used. Finally, a method for bypassing the amplitude nonlinearity is presented with the aim of reading sensor capacitance.

  12. Inter-reader variability in alternate forced choice studies

    Science.gov (United States)

    Huda, W.; Ogden, K. M.; Samei, E.; Scalzetti, E. M.; Lavallee, R. L.; Roskopf, M. L.

    2008-03-01

    In this study, we investigated differences in detection performance for twelve observers who each generated a CT contrast detail curve. An anthropomorphic newborn phantom's abdomen was imaged using a GE Light Speed CT scanner (4-slice). Alternate Forced Choice (AFC) experiments were performed with lesions sizes ranging from 2.5 to 12.5 mm to determine the intensity needed to achieve 92% correct (I 92%). Following training, twelve readers consisting of (2 technologists, 4 college students, 4 medical students, and 2 radiology residents) generated a single contrast detail curve. Eight readers produced approximately linear contrast detail curves while the remaining four readers required a second order polynomial fit because of reduced performance when detecting the largest (i.e., 12.5 mm) lesion. For the three smallest lesions, the coefficient of variation between the twelve readers was ~12%, which increases with increasing lesion size to ~23% for 12.5 mm lesion size. The ratio of the maximum I 92% to minimum I 92% values was ~1.6 for the smallest lesions, which increased to a factor of ~2.1 for the 12.5 mm lesion. Our results show that minimizing inter-reader variability in our AFC experiments could be achieved by eliminating the largest lesion that cause detection problems in one third of observers. The combined experimental data showed that the slope of the contrast detail curve was -0.42, lower than the value of -1.0 predicted by the Rose model, suggesting that the noise texture in CT associated with both quantum mottle and anatomic structure is an important factor affecting detection of these lesions.

  13. The Remodeling Process: A Grounded Theory Study of Perceptions of Treatment among Adult Male Incest Offenders.

    Science.gov (United States)

    Scheela, Rochelle A.

    1992-01-01

    Conducted grounded theory study to explore incest offender perceptions of treatment to generate explanatory theory of sexual abuse treatment process. Findings from theoretical sampling of 20 adult male incest offenders revealed that offenders felt remodeling process occurred as they faced discovery of their abuse and went through treatment.…

  14. Constructing Grounded Theory: Reflections on a Case Study of a Professor of Architectural Design.

    Science.gov (United States)

    Janesick, Valerie J.

    1982-01-01

    Discusses a case study describing the philosophy of teaching design to architecture students as practiced by one professor. A model of his architectural design curriculum emerged. Three issues arose: constructing theory from data grounded in experience, posing appropriate research questions, and understanding the roots of ethnographic inquiry.…

  15. Factors Affecting Christian Parents' School Choice Decision Processes: A Grounded Theory Study

    Science.gov (United States)

    Prichard, Tami G.; Swezey, James A.

    2016-01-01

    This study identifies factors affecting the decision processes for school choice by Christian parents. Grounded theory design incorporated interview transcripts, field notes, and a reflective journal to analyze themes. Comparative analysis, including open, axial, and selective coding, was used to reduce the coded statements to five code families:…

  16. Factors Affecting Christian Parents' School Choice Decision Processes: A Grounded Theory Study

    Science.gov (United States)

    Prichard, Tami G.; Swezey, James A.

    2016-01-01

    This study identifies factors affecting the decision processes for school choice by Christian parents. Grounded theory design incorporated interview transcripts, field notes, and a reflective journal to analyze themes. Comparative analysis, including open, axial, and selective coding, was used to reduce the coded statements to five code families:…

  17. Culturally Responsive Teaching in the Context of Mathematics: A Grounded Theory Case Study

    Science.gov (United States)

    Bonner, Emily P.; Adams, Thomasenia L.

    2012-01-01

    In this grounded theory case study, four interconnected, foundational cornerstones of culturally responsive mathematics teaching (CRMT), communication, knowledge, trust/relationships, and constant reflection/revision, were systematically unearthed to develop an initial working theory of CRMT that directly informs classroom practice. These…

  18. Mixed Waste Management Facility (MWMF) Old Burial Ground (OBG) source control technology and inventory study

    Energy Technology Data Exchange (ETDEWEB)

    Flach, G.P.; Rehder, T.E.; Kanzleiter, J.P.

    1996-10-02

    This report has been developed to support information needs for wastes buried in the Burial Ground Complex. Information discussed is presented in a total of four individual attachments. The general focus of this report is to collect information on estimated source inventories, leaching studies, source control technologies, and to provide information on modeling parameters and associated data deficiencies.

  19. Technology Solutions Case Study: Ground Source Heat Pump Research, TaC Studios Residence, Atlanta, Georigia

    Energy Technology Data Exchange (ETDEWEB)

    None

    2014-09-01

    This case study describes the construction of a new test home that demonstrates current best practices for the mixed-humid climate, including a high performance ground source heat pump for heating and cooling, a building envelope featuring advanced air sealing details and low-density spray foam insulation, and glazing that exceeds ENERGY STAR requirements.

  20. Theoretical study of the ground state of (EDO-TTF)(2)PF6

    NARCIS (Netherlands)

    Linker, Gerrit-Jan; van Duijnen, Piet Th.; van Loosdrecht, Paul H.M.; Broer, Ria

    2015-01-01

    In this paper we present a theoretical study of the nature of the ground state of the (EDO-TTF)(2)PF6 charge transfer salt by using ab initio quantum chemical theory for clusters in vacuum, for embedded clusters and for the periodic system. Exemplary for other organic charge transfer systems, we sho

  1. Attractive forces study in macromolecules and critical systems; Etude des forces attractives dans les macromolecules et les systemes critiques

    Energy Technology Data Exchange (ETDEWEB)

    Penninckx-Sans, A.

    1995-07-10

    The attractive forces effect is particularly interesting at the proximity of a critical point. In a liquid system, there are two kinds of attractive forces in presence : the forces bound to the solution volume and those generated by the presence of the solution surface or by a solution interface. In the first case, the attractive forces are the more important as the system is in a critical field. For this study, the selected example is a polymer solution in a two solvents mixture. A formulation in terms of way integrals as part of statistical physics has lead us to find again some known results on the polymer chain conformation in the presence of two solvents (collapse of the polymer on itself) far from the critical point and to extend these results to the critical field. In the case of attractive forces created by the surface in some critical systems (polymer of infinite size in solution and binary mixture near the de mixture point), the adsorption profile created by the attraction of one specie by the surface, follows a scale law. The optical methods usually used for the study of these systems do not give characteristic sign of concentration profile in power law. In the case where the interaction potential between radiation and matter is attractive, the reflectivity gives a separate mark of the existence of the scale law in the form of a resonance. After some theoretical forecasts, the author has used this method on the binary mixture methanol-cyclohexane in order to reveal experimentally a reflectivity pseudo-discontinuity and then the existence of the power law in the critical adsorption profile. (O.L.). 69 refs., 60 tabs.

  2. Synchronizing atomic force microscopy force mode and fluorescence microscopy in real time for immune cell stimulation and activation studies

    Energy Technology Data Exchange (ETDEWEB)

    Cazaux, Séverine; Sadoun, Anaïs; Biarnes-Pelicot, Martine; Martinez, Manuel; Obeid, Sameh [Aix Marseille Université, LAI UM 61, Marseille F-13288 (France); Inserm, UMR-S 1067, Marseille F-13288 (France); CNRS, UMR 7333, Marseille F-13288 (France); Bongrand, Pierre [Aix Marseille Université, LAI UM 61, Marseille F-13288 (France); Inserm, UMR-S 1067, Marseille F-13288 (France); CNRS, UMR 7333, Marseille F-13288 (France); APHM, Hôpital de la Conception, Laboratoire d’Immunologie, Marseille F-13385 (France); Limozin, Laurent [Aix Marseille Université, LAI UM 61, Marseille F-13288 (France); Inserm, UMR-S 1067, Marseille F-13288 (France); CNRS, UMR 7333, Marseille F-13288 (France); Puech, Pierre-Henri, E-mail: pierre-henri.puech@inserm.fr [Aix Marseille Université, LAI UM 61, Marseille F-13288 (France); Inserm, UMR-S 1067, Marseille F-13288 (France); CNRS, UMR 7333, Marseille F-13288 (France)

    2016-01-15

    A method is presented for combining atomic force microscopy (AFM) force mode and fluorescence microscopy in order to (a) mechanically stimulate immune cells while recording the subsequent activation under the form of calcium pulses, and (b) observe the mechanical response of a cell upon photoactivation of a small G protein, namely Rac. Using commercial set-ups and a robust signal coupling the fluorescence excitation light and the cantilever bending, the applied force and activation signals were very easily synchronized. This approach allows to control the entire mechanical history of a single cell up to its activation and response down to a few hundreds of milliseconds, and can be extended with very minimal adaptations to other cellular systems where mechanotransduction is studied, using either purely mechanical stimuli or via a surface bound specific ligand. - Highlights: • A signal coupling AFM and fluorescence microscopy was characterized for soft cantilevers. • It can be used as an intrinsic timer to synchronize images and forces. • Mechanical stimulation of single immune cells while recording calcium fluxes was detailed. • Light-induced mechanical modifications of lymphocytes using a PA-Rac protein were demonstrated. • The precautions and limitations of use of this effect were presented.

  3. Adolescent girls' experiences of underlying social processes triggering stress in their everyday life: a grounded theory study.

    Science.gov (United States)

    Haraldsson, Katarina; Lindgren, Eva-Carin; Mattsson, Bengt; Fridlund, Bengt; Marklund, Bertil

    2011-04-01

    The aim of this study was to generate a theoretical model of underlying social processes that trigger stress in adolescent girls' everyday life. In-depth interviews regarding the experiences of stress at home, school and during leisure time were conducted with 14 17-year-old schoolgirls. Data were analysed by means of the grounded theory method. Stress was triggered in the interaction between responsibility and the way in which the girls were encountered. Triggered emotional reactions took the form of four dimensions of stress included ambivalence, frustration, despair and downheartedness. These reactions were dependent on whether the girls voluntary assumed responsibility for various situations or whether they were forced, or felt they were being forced, to assume responsibility in interaction with an encounter characterized by closeness or distance. These forms of stress reactions could appear in one dimension and subsequently shift to another. From the public health perspective, the generated stress model can be used in the planning and implementation of future actions to prevent stress and promote well-being related to stress in adolescent girls.

  4. A Study of Slovenian Armed Forces Ammunition Forecasting Methodology

    Science.gov (United States)

    2012-12-14

    multiplying factor that addressed the operation type, either defense or offence , with additional variants depending on high, moderate, or low...level planning method, consumption rates based on NATO consumption rates for defense, offence , and delay operation. SAF Force Command is...systems, detection and kill probabilities, 32 terrain and environmental data, the Combat Sample Generator will use doctrine and tactics to describe the

  5. Cross-check for completeness: exploring a novel use of Leximancer in a Grounded Theory study

    OpenAIRE

    Harwood, I.A.; Gapp, R.; Stewart, H.

    2015-01-01

    This paper investigates the potential for Leximancer software to actively support the Grounded Theory (GT) analyst in assessing the ‘completeness’ of their study. The case study takes an existing GT study and retrospectively analyzes the data with Leximancer. The Leximancer output showed encouraging similarities to the main themes emerging from the GT analysis; but not sufficiently at the selective coding level to justifiably claim a definitive cross-check for overall theoretical saturation. ...

  6. A study of ground-structure interaction in dynamic plate load testing

    Science.gov (United States)

    Guzina, Bojan B.; Nintcheu Fata, Sylvain

    2002-10-01

    A mathematical treatment is presented for the forced vertical vibration of a padded annular footing on a layered viscoelastic half-space. On assuming a depth-independent stress distribution for the interfacial buffer, the set of triple integral equations stemming from the problem is reduced to a Fredholm integral equation of the second kind. The solution method, which is tailored to capture the stress concentrations beneath footing edges, is highlighted. To cater to small-scale geophysical applications, the model is used to investigate the near-field effects of ground-loading system interaction in dynamic geotechnical and pavement testing. Numerical results indicate that the uniform-pressure assumption for the contact load between the composite disc and the ground which is customary in dynamic plate load testing may lead to significant errors in the diagnosis of subsurface soil and pavement conditions. Beyond its direct application to non-intrusive site characterization, the proposed solution can be used in the seismic analysis of a variety of structures involving annular foundation geometries.

  7. NUMERICAL ANALYSIS OF THE GROUND EFFECT ON INSECT HOVERING

    Institute of Scientific and Technical Information of China (English)

    GAO Tong; LIU Nan-sheng; LU Xi-yun

    2008-01-01

    The ground effect on insect hovering is investigated using an immersed boundary-lattice Boltzmann method to solve the two-dimensional incompressible Navier-Stokes equations. A virtual model of an elliptic foil with oscillating translation and rotation near a ground is used. The objective of this study is to deal with the ground effect on the unsteady forces and vortical structures and to get the physical insights in the relevant mechanisms. Two typical insect hovering modes, I.e., normal and dragonfly hovering mode, are examined. Systematic computations have been carried out for some parameters, and the ground effect on the unsteady forces and vortical structures is analyzed.

  8. Implementation of Organizational Change in the Air Force: a Case Study

    Science.gov (United States)

    1989-09-01

    ve) Lfl DTIC &’ELECTE IMPLEMENTATION OF ORGANIZATIONAL CHANGE IN THE AIR FORCE: A CASE STUDY THESIS Ronald D. Taylor First Lieutenant, USAF AFIT/GLM...022 AFIT/GLM/LSR/89S-66 IMPLEMENTATION OF ORGANIZATIONAL CHANGE IN THE AIR FORCE: A CASE STUDY THESIS Ronald D. Taylor First Lieutenant, USAF AFIT/GLM...Department of Defense. AFIT/GLM/LSR/89S-66 IMPLEMENTATION OF ORGANIZATIONAL CHANGE IN THE AIR FORCE: A CASE STUDY THESIS Presented to the Faculty of the

  9. A Numerical Study on the Screening of Blast-Induced Waves for Reducing Ground Vibration

    Science.gov (United States)

    Park, Dohyun; Jeon, Byungkyu; Jeon, Seokwon

    2009-06-01

    Blasting is often a necessary part of mining and construction operations, and is the most cost-effective way to break rock, but blasting generates both noise and ground vibration. In urban areas, noise and vibration have an environmental impact, and cause structural damage to nearby structures. Various wave-screening methods have been used for many years to reduce blast-induced ground vibration. However, these methods have not been quantitatively studied for their reduction effect of ground vibration. The present study focused on the quantitative assessment of the effectiveness in vibration reduction of line-drilling as a screening method using a numerical method. Two numerical methods were used to analyze the reduction effect toward ground vibration, namely, the “distinct element method” and the “non-linear hydrocode.” The distinct element method, by particle flow code in two dimensions (PFC 2D), was used for two-dimensional parametric analyses, and some cases of two-dimensional analyses were analyzed three-dimensionally using AUTODYN 3D, the program of the non-linear hydrocode. To analyze the screening effectiveness of line-drilling, parametric analyses were carried out under various conditions, with the spacing, diameter of drill holes, distance between the blasthole and line-drilling, and the number of rows of drill holes, including their arrangement, used as parameters. The screening effectiveness was assessed via a comparison of the vibration amplitude between cases both with and without screening. Also, the frequency distribution of ground motion of the two cases was investigated through fast Fourier transform (FFT), with the differences also examined. From our study, it was concluded that line-drilling as a screening method of blast-induced waves was considerably effective under certain design conditions. The design details for field application have also been proposed.

  10. Bugetary Perspective on Police Force: A Case Study on Slovenia

    Directory of Open Access Journals (Sweden)

    Uroš PINTERIČ

    2011-06-01

    Full Text Available The author explores some of the generally overlooked roles of police force in contemporary world. The last decade was strongly marked by a need for increased safety, and police forces were strongly motivated to change the security paradigm. However, a connection between police and security can be seen as well, through the budget, where the activity of the police is measured using the amount of revenues obtained from fees and fines. In the case of the Slovenian security situation and fine revenues, police has both the main role in providing a certain level of national internal security and an important budgetary role by providing 1% of the Slovenian budgetary revenues that are sufficient to cover the expenses of approximately 15 main institutions belonging to the political system.

  11. A Study of Nucleate Boiling with Forced Convection in Microgravity

    Science.gov (United States)

    Merte, Herman, Jr.

    1999-01-01

    The ultimate objective of basic studies of flow boiling in microgravity is to improve the understanding of the processes involved, as manifested by the ability to predict its behavior. This is not yet the case for boiling heat transfer even in earth gravity, despite the considerable research activity over the past 30 years. The elements that constitute the nucleate boiling process - nucleation, growth, motion, and collapse of the vapor bubbles (if the bulk liquid is subcooled) - are common to both pool and flow boiling. It is well known that the imposition of bulk liquid motion affects the vapor bubble behavior relative to pool boiling, but does not appear to significantly influence the heat transfer. Indeed, it has been recommended in the past that empirical correlations or experimental data of pool boiling be used for design purposes with forced convection nucleate boiling. It is anticipated that such will most certainly not be possible for boiling in microgravity, based on observations made with pool boiling in microgravity. In earth gravity buoyancy will act to remove the vapor bubbles from the vicinity of the heater surface regardless of how much the imposed bulk velocity is reduced, depending, of course, on the geometry of the system. Vapor bubbles have been observed to dramatically increase in size in pool boiling in microgravity, and the heat flux at which dryout took place was reduced considerably below what is generally termed the critical heat flux (CHF) in earth gravity, depending on the bulk liquid subcooling. However, at heat flux levels below dryout, the nucleate pool boiling process was enhanced considerably over that in earth gravity, in spite of the large vapor bubbles formed in microgravity and perhaps as a consequence. These large vapor bubbles tended to remain in the vicinity of the heater surface, and the enhanced heat transfer appeared to be associated with the presence of what variously has been referred to as a liquid microlayer between the

  12. Atomic Force Microscopy Application in Biological Research: A Review Study

    Directory of Open Access Journals (Sweden)

    Surena Vahabi

    2013-06-01

    Full Text Available Atomic force microscopy (AFM is a three-dimensional topographic technique with a high atomic resolution to measure surface roughness. AFM is a kind of scanning probe microscope, and its near-field technique is based on the interaction between a sharp tip and the atoms of the sample surface. There are several methods and many ways to modify the tip of the AFM to investigate surface properties, including measuring friction, adhesion forces and viscoelastic properties as well as determining the Young modulus and imaging magnetic or electrostatic properties. The AFM technique can analyze any kind of samples such as polymers, adsorbed molecules, films or fibers, and powders in the air whether in a controlled atmosphere or in a liquid medium. In the past decade, the AFM has emerged as a powerful tool to obtain the nanostructural details and biomechanical properties of biological samples, including biomolecules and cells. The AFM applications, techniques, and -in particular- its ability to measure forces, are not still familiar to most clinicians. This paper reviews the literature on the main principles of the AFM modality and highlights the advantages of this technique in biology, medicine, and- especially- dentistry. This literature review was performed through E-resources, including Science Direct, PubMed, Blackwell Synergy, Embase, Elsevier, and Scholar Google for the references published between 1985 and 2010.

  13. Study on Some Physico-Chemical Characteristics of Ground Water of District Rampur - A Statistical Approach

    OpenAIRE

    Susheel Kumar Sindhu; Amit Sharma

    2007-01-01

    A systematic study has been carried out to explore the water quality index of ground water of various tehsils of Rampur district. Twenty five water samples from tube wells, open wells and hand pumps at various locations were collected and analyzed for pH, nitrate, turbidity, total dissolve solid, chlorides, total hardness, alkalinity and fluoride. In this study overall water quality of Rampur district is very poor and unsuitable for drinking purpose. Water quality of Bilaspur, Shahabad and Ra...

  14. Synchronous Study of Ferroresonance and Inrush Current Phenomena and their Related Reasons in Ground Power Networks

    Science.gov (United States)

    Akrami, Amin; Ghaderi, Mohammad; Ghadi, Saeed

    2010-01-01

    Energizing the power transformers usually results in flowing very high inrush currents. This harmful current can be minimized using controlled switching and considering the value of residual flux. But nowadays, developing the ground power networks results in high increment of ferroresonance phenomenon occurrence due to the line' capacitance reactance and nonlinear inductive reactance of power transformer's core. In this study, these transient phenomena and their cause have studied synchronously.

  15. Theoretical Studies on Thermal Decomposition of Benzoyl Peroxide in Ground State

    Institute of Scientific and Technical Information of China (English)

    SUN Cheng-ke; YANG Si-ya; LIN Xue-fei; MA Si-yu; LI Zong-he

    2003-01-01

    Systematic studies of the thermal decomposition mechanism of benzoyl peroxide(BPO) in ground state, leading to various intermediates, products and the potential energy surface(PES) of possible dissociation reactions were made computationally. The structures of the transition states and the activation energies for all the paths causing the formation of the reaction products mentioned above were calculated by the AM1 semi-empirical method. This method is shown to to be one predict correctly the preferred pathway for the title reaction. It has been found that in ground state, the thermal decomposition of benzoyl peroxide has two kinds of paths. The first pathway PhC(O)O-OC(O)Ph→PhC(O)O*→Ph*+CO2 produces finally phenyl radicals and carbon dioxide. And the second pathway PhC(O)OO-C(O)Ph→PhC(O)OO*+PhC(O)*→PhC(O)*+O2→Ph*+CO+O2, via which the reaction takes place only in two steps, produces oxygen and PhC(O)* radicals, and the further thermal dissociation of PhC(O)* is quite difficult because of the high activation energy in ground state. The calculated activation energies and reaction enthalpies are in good agreement with the experimental values. The research results also show that also the thermal dissociation process of the two bonds or the three bonds for the benzoyl peroxide doesn′t take place in ground state.

  16. Railway cuttings and embankments: Experimental and numerical studies of ground vibration.

    Science.gov (United States)

    Kouroussis, Georges; Connolly, David P; Olivier, Bryan; Laghrouche, Omar; Costa, Pedro Alves

    2016-07-01

    Railway track support conditions affect ground-borne vibration generation and propagation. Therefore this paper presents a combined experimental and numerical study into high speed rail vibrations for tracks on three types of support: a cutting, an embankment and an at grade section. Firstly, an experimental campaign is undertaken where vibrations and in-situ soil properties are measured at three Belgian rail sites. A finite element model is then developed to recreate the complex ground topology at each site. A validation is performed and it is found that although the at-grade and embankment cases show a correlation with the experimental results, the cutting case is more challenging to replicate. Despite this, each site is then analysed to determine the effect of earthworks profile on ground vibrations, with both the near and far fields being investigated. It is found that different earthwork profiles generate strongly differing ground-borne vibration characteristics, with the embankment profile generating lower vibration levels in comparison to the cutting and at-grade cases. Therefore it is concluded that it is important to consider earthwork profiles when undertaking vibration assessments.

  17. Is air transport of stroke patients faster than ground transport? A prospective controlled observational study.

    Science.gov (United States)

    Hesselfeldt, Rasmus; Gyllenborg, Jesper; Steinmetz, Jacob; Do, Hien Quoc; Hejselbæk, Julie; Rasmussen, Lars S

    2014-04-01

    Helicopters are widely used for interhospital transfers of stroke patients, but the benefit is sparsely documented. We hypothesised that helicopter transport would reduce system delay to thrombolytic treatment at the regional stroke centre. In this prospective controlled observational study, we included patients referred to a stroke centre if their ground transport time exceeded 30 min, or they were transported by a secondarily dispatched, physician-staffed helicopter. The primary endpoint was time from telephone contact to triaging neurologist to arrival in the stroke centre. Secondary endpoints included modified Rankin Scale at 3 months, 30-day and 1-year mortality. A total of 330 patients were included; 265 with ground transport and 65 with helicopter, of which 87 (33%) and 22 (34%), received thrombolysis, respectively (p=0.88). Time from contact to triaging neurologist to arrival in the regional stroke centre was significantly shorter in the ground group (55 (34-85) vs 68 (40-85) min, pground group (67 (42-136) km) than in the helicopter group (83 (46-143) km) (pground and helicopter transport. We found significantly shorter time from contact to triaging neurologist to arrival in the regional stroke centre if stroke patients were transported by primarily dispatched ground ambulance compared with a secondarily dispatched helicopter.

  18. Study of polonium isotopes ground state properties by simultaneous atomic- and nuclear-spectroscopy

    CERN Multimedia

    Koester, U H; Kalaninova, Z; Imai, N

    2007-01-01

    We propose to systematically study the ground state properties of neutron deficient $^{192-200}$Po isotopes by means of in-source laser spectroscopy using the ISOLDE laser ion source coupled with nuclear spectroscopy at the detection setup as successfully done before by this collaboration with neutron deficient lead isotopes. The study of the change in mean square charge radii along the polonium isotope chain will give an insight into shape coexistence above the mid-shell N = 104 and above the closed shell Z = 82. The hyperfine structure of the odd isotopes will also allow determination of the nuclear spin and the magnetic moment of the ground state and of any identifiable isomer state. For this study, a standard UC$_{x}$ target with the ISOLDE RILIS is required for 38 shifts.

  19. Conducting a Grounded Theory Study in a Language Other Than English

    Directory of Open Access Journals (Sweden)

    Intansari Nurjannah

    2014-03-01

    Full Text Available Translation can be a problem area for researchers conducting qualitative studies in languages other than English who intend to publish the results in an English-language journal. Analyzing the data is also complex when the research team consists of people from different language backgrounds. Translation must be considered as an issue in its own right to maintain the integrity of the research, especially in a grounded theory study. In this article, we offer guidelines for the process of translation for data analysis in a grounded theory study in which the research was conducted in a language other than English (Indonesian. We make recommendations about procedures to choose when, who, and how to translate data. The translation procedure is divided into four steps which are as follows: translation in the process of coding, translation in the process of team discussion, translation in the process of advanced coding, and ensuring the accuracy of translation.

  20. Study of high-definition and stereoscopic head-aimed vision for improved teleoperation of an unmanned ground vehicle

    Science.gov (United States)

    Tyczka, Dale R.; Wright, Robert; Janiszewski, Brian; Chatten, Martha Jane; Bowen, Thomas A.; Skibba, Brian

    2012-06-01

    Nearly all explosive ordnance disposal robots in use today employ monoscopic standard-definition video cameras to relay live imagery from the robot to the operator. With this approach, operators must rely on shadows and other monoscopic depth cues in order to judge distances and object depths. Alternatively, they can contact an object with the robot's manipulator to determine its position, but that approach carries with it the risk of detonation from unintentionally disturbing the target or nearby objects. We recently completed a study in which high-definition (HD) and stereoscopic video cameras were used in addition to conventional standard-definition (SD) cameras in order to determine if higher resolutions and/or stereoscopic depth cues improve operators' overall performance of various unmanned ground vehicle (UGV) tasks. We also studied the effect that the different vision modes had on operator comfort. A total of six different head-aimed vision modes were used including normal-separation HD stereo, SD stereo, "micro" (reduced separation) SD stereo, HD mono, and SD mono (two types). In general, the study results support the expectation that higher resolution and stereoscopic vision aid UGV teleoperation, but the degree of improvement was found to depend on the specific task being performed; certain tasks derived notably more benefit from improved depth perception than others. This effort was sponsored by the Joint Ground Robotics Enterprise under Robotics Technology Consortium Agreement #69-200902 T01. Technical management was provided by the U.S. Air Force Research Laboratory's Robotics Research and Development Group at Tyndall AFB, Florida.

  1. Near fault broadband ground motion simulation with empirical Green's functions: the Upper Rhine Graben case study

    Science.gov (United States)

    Del Gaudio, Sergio; Hok, Sébastian; Causse, Mathieu; Festa, Gaetano; Lancieri, Maria

    2016-04-01

    A fundamental stage in seismic hazard assessment is the prediction of realistic ground motion for potential future earthquakes. To do so, one of the steps is to make an estimation of the expected ground motion level and this is commonly done by the use of ground motion prediction equations (GMPEs). Nevertheless GMPEs do not represent the whole variety of source processes and this can lead to incorrect estimates for some specific case studies, such as in the near-fault range because of the lack of records of large earthquakes at short distances. In such cases, ground motion simulations can be a valid tool to complement prediction equations for scenario studies, provided that both source and propagation are accurately described and uncertainties properly addressed. Such simulations, usually referred to as "blind", require the generation of a population of ground motion records that represent the natural variability of the source process for the target earthquake scenario. In this study we performed simulations using the empirical Green's function technique, which consists in using records of small earthquakes as the medium transfer function provided the availability of small earthquakes located close to the target fault and recorded at the target site. The main advantage of this technique is that it does not require a detailed knowledge of the propagation medium, which is not always possible, but requires availability of high quality records of small earthquakes in the target area. We couple this empirical approach with a k-2 kinematic source model, which naturally let us to introduce high frequency in the source description. Here we present an application of our technique to the Upper Rhine Graben. This is an active seismic region with a moderate rate of seismicity and for which it is interesting to provide ground motion estimation in the vicinity of the faults to be compared with estimations traditionally provided by GMPEs in a seismic hazard evaluation study. We

  2. Implications of male circumcision for women in Papua New Guinea: a transformational grounded theory study.

    Science.gov (United States)

    Redman-MacLaren, Michelle; Mills, Jane; Tommbe, Rachael; MacLaren, David; Speare, Rick; McBride, William J H

    2017-07-27

    Male circumcision reduces the risk of female-to-male transmission of human immunodeficiency virus (HIV) and is being explored for HIV prevention in Papua New Guinea (PNG). PNG has a concentrated HIV epidemic which is largely heterosexually transmitted. There are a diverse range of male circumcision and penile modification practices across PNG. Exploring the implications of male circumcision for women in PNG is important to inform evidence-based health policy that will result in positive, intended consequences. The transformational grounded theory study incorporated participatory action research and decolonizing methodologies. In Phase One, an existing data set from a male circumcision study of 861 male and 519 female participants was theoretically sampled and analyzed for women's understanding and experience of male circumcision. In Phase Two of the study, primary data were co-generated with 64 women in seven interpretive focus group discussions and 11 semi-structured interviews to develop a theoretical model of the processes used by women to manage the outcomes of male circumcision. In Phase Three participants assisted to refine the developing transformational grounded theory and identify actions required to improve health. Many women know a lot about male circumcision and penile modification and the consequences for themselves, their families and communities. Their ability to act on this knowledge is determined by numerous social, cultural and economic factors. A transformational grounded theory was developed with connecting categories of: Women Know a Lot, Increasing Knowledge; Increasing Options; and Acting on Choices. Properties and dimensions of each category are represented in the model, along with the intervening condition of Safety. The condition of Safety contextualises the overarching lived realty for women in PNG, enables the inclusion of men in the transformational grounded theory model, and helps to explain relationships between men and women. The

  3. ATOMIC FORCE MICROSCOPY STUDIES OF POLYCAPROLACTONE RINGED SPHERULITES

    Institute of Scientific and Technical Information of China (English)

    Jian-bin Zhang; De-zhu Ma; Hua Zhong; Xiao-lie Luo

    2000-01-01

    The surface morphology of free-surface PCL ringed spherulites was investigated by using atomic force microscopy. The spherulites were obtained by crystallization of PCL/PVC blends of different compositions. It was found that the ringed spherulite exhibited regularly fluctuating rings on its surface. Compared with the bright-dark ring pattern of the spherulite under a polarizing microscope, it was proved that the optical characteristics of the ringed spherulite under polarizing microscope coincided with its surface characteristics. The bright rings in polarizing micrographs of the spherulite coincided with the convex rings on its surface, while the dark rings coincided with the concave rings.

  4. A case study using grounded theory of environmental education in an alternative school

    Science.gov (United States)

    Lyle, Laurina Isabella

    This study examines the appropriate practices of an alternative school in west Tennessee in educating middle and high school students in long- and short-term alternative school placement. The participants included 23 students in grades 7-12 who had been classified as disruptive or failing academically, thus requiring intervention. The study's aim was to determine the effect of environmental education on the academic progress of these students. Data were obtained through multi-triangulation methodology and analyzed by grounded theory methodology. Four concepts emerged: social dynamics, relevance, conversion, and affirmation. A grounded theory for effective alternative education through environmental education based on the emergent concepts is proposed, including a new learning framework from which alternative school educators can design curricula and instructional units.

  5. Eurajoki Olkiluoto study on species of ground beetles and ants 2008

    Energy Technology Data Exchange (ETDEWEB)

    Santaharju, J.; Helminen, S.-L.; Yrjoelae, R. (Environmental Research Yrjoelae Ltd, Helsinki (Finland))

    2009-02-15

    The species of ants and Ground beetles at Olkiluoto in Eurajoki were studied in the summer of 2008 during two trapping periods: in June and August. The research goal was to clarify the species on Olkiluoto island of the earlier mentioned groups, at least at the family level, and to collect samples for further examination by Posiva. The trapping areas were selected at Olkiluoto in Posiva test monitoring sectors, a part of the trapping areas was the same as the earlier study. Species of ants, depending on their particular species, are a very dominating group of insects. The ants are the most important predators, scavengers and soil movers in Finnish forests. It looks as if the biomass of ants may be more than 10% of the biomass of all animals in certain areas of Finnish forests. In Finland there are about 60 species of ants that have been observed. They have been divided into four sub-groups, which are Myrmicinae, Formicinae, Ponerinae and Dolichoderinae. In Finland there are close to 300 species of ground beetles (Carabidae), which are divided into dozens of different families. The species, to a great extent, consist mostly of predatory insects that prey on microbes in field layers, but a part of them are specialized in feeding on flora. Ground beetles are usually divided into three groups according to their choice of habitat: Species that favour open biotopes, species that favour forests, and generalist species that can thrive in a variety of environments. Ground beetles also reflect changes in their living environment, and possibly they can be significant as socalled bio-indicators. Pitfall traps were used as the method of research. The preservative fluid used was ethanol (50%) with dishwashing liquid to remove surface tension. The points were located in various different biotopes in fields, meadows and forests. The data collected was defined as a minimum for the family level of Ground beetles and for ants to the species or species pairs. The species of Ground

  6. Questions Arising about Emergence, Data Collection, and Its Interaction with Analysis in a Grounded Theory Study

    Directory of Open Access Journals (Sweden)

    Catherine Bruce

    2007-03-01

    Full Text Available There has been a strong call for increased clarity and transparency of method in qualitative research. Although qualitative data analysis has been detailed, data management has not been made as transparent in the literature. How do data collection and analysis interact in practical terms? What constitutes sufficient data? And can research be both planful and emergent? In this paper, the author highlights several methodological strategies for addressing data management challenges in a grounded theory study of preservice mathematics teachers.

  7. Perinatal Toxicity and Carcinogenicity Studies of Styrene –Acrylonitrile Trimer, A Ground Water Contaminant

    OpenAIRE

    Behl, Mamta; Elmore, Susan A.; Malarkey, David E.; Hejtmancik, Milton R.; Gerken, Diane K.; Chhabra, Rajendra S.

    2013-01-01

    Styrene Acrylonitrile (SAN) Trimer is a by-product in the production of acrylonitrile styrene plastics. Following a report of a childhood cancer cluster in the Toms River section of Dover Township, New Jersey, SAN Trimer was identified as one of the groundwater contaminants at Reich Farm Superfund site in the township. The contaminants from the Reich Farm site’s ground water plume impacted two wells at the Parkway well field. The National Toxicology Program (NTP) studied the toxicity and carc...

  8. Factors Relating to the Success or Failure of College Algebra Internet Students: A Grounded Theory Study

    OpenAIRE

    Walker, Christine

    2008-01-01

    The purpose of this grounded theory study was to discover the factors that contribute to the success or failure of college algebra for students taking college algebra by distance education Internet, and then generate a theory of success or failure of the group of College Algebra Internet students at one Utah college. Qualitative data were collected and analyzed on students’ perceptions and perspectives of a College Algebra Internet course that they took during the spring or summer 2006 semest...

  9. Study of Ground Treatment on Improvement of Pile Foundation Response in Liquefiable Soils

    OpenAIRE

    Yulong, Chen

    2016-01-01

    International audience; In light of the disastrous the 2011 Tohoku Pacific Earthquake, the government of Japan has conducted studies to revise the seismic design code, and elevated peak ground accelerations have been adopted. Consequently, revisions on existing design to comply with the updated code are required for public projects that are still undergoing. The design safety needs to be reassessed, and implementation of strengthening measures is required if deemed necessary. For liquefaction...

  10. Study on the Driving Forces of Rocky Desertification in Guizhou Province Based on Variation Coefficient Method

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    [Objective] The aim was to study the driving forces of rocky desertification in Guizhou Province. [Method] Based on GIS and RS technology, the main driving forces of rocky desertification in Guizhou Province were analyzed by means of correlation analysis and variation coefficient method, and then the distribution of rocky desertification in Guizhou Province was assessed synthetically. [Result] The main driving forces of rocky desertification in Guizhou Province were vegetation cover, rainfall, peasant incom...

  11. A preliminary study on surface ground deformation near shallow foundation induced by strike-slip faulting

    Science.gov (United States)

    Wong, Pei-Syuan; Lin, Ming-Lang

    2016-04-01

    According to investigation of recent earthquakes, ground deformation and surface rupture are used to map the influenced range of the active fault. The zones of horizontal and vertical surface displacements and different features of surface rupture are investigated in the field, for example, the Greendale Fault 2010, MW 7.1 Canterbury earthquake. The buildings near the fault rotated and displaced vertically and horizontally due to the ground deformation. Besides, the propagation of fault trace detoured them because of the higher rigidity. Consequently, it's necessary to explore the ground deformation and mechanism of the foundation induced by strike-slip faulting for the safety issue. Based on previous study from scaled analogue model of strike-slip faulting, the ground deformation is controlled by material properties, depth of soil, and boundary condition. On the condition controlled, the model shows the features of ground deformation in the field. This study presents results from shear box experiment on small-scale soft clay models subjected to strike-slip faulting and placed shallow foundations on it in a 1-g environment. The quantifiable data including sequence of surface rupture, topography and the position of foundation are recorded with increasing faulting. From the result of the experiment, first en echelon R shears appeared. The R shears rotated to a more parallel angle to the trace and cracks pulled apart along them with increasing displacements. Then the P shears crossed the basement fault in the opposite direction appears and linked R shears. Lastly the central shear was Y shears. On the other hand, the development of wider zones of rupture, higher rising surface and larger the crack area on surface developed, with deeper depth of soil. With the depth of 1 cm and half-box displacement 1.2 cm, en echelon R shears appeared and the surface above the fault trace elevated to 1.15 mm (Dv), causing a 1.16 cm-wide zone of ground-surface rupture and deformation

  12. Laboratory study of low-β forces in arched, line-tied magnetic flux ropes

    Science.gov (United States)

    Myers, C. E.; Yamada, M.; Ji, H.; Yoo, J.; Jara-Almonte, J.; Fox, W.

    2016-11-01

    The loss-of-equilibrium is a solar eruption mechanism whereby a sudden breakdown of the magnetohydrodynamic force balance in the Sun's corona ejects a massive burst of particles and energy into the heliosphere. Predicting a loss-of-equilibrium, which has more recently been formulated as the torus instability, relies on a detailed understanding of the various forces that hold the pre-eruption magnetic flux rope in equilibrium. Traditionally, idealized analytical force expressions are used to derive simplified eruption criteria that can be compared to solar observations and modeling. What is missing, however, is a validation that these idealized analytical force expressions can be applied to the line-tied, low-aspect-ratio conditions of the corona. In this paper, we address this shortcoming by using a laboratory experiment to study the forces that act on long-lived, arched, line-tied magnetic flux ropes. Three key force terms are evaluated over a wide range of experimental conditions: (1) the upward hoop force; (2) the downward strapping force; and (3) the downward toroidal field tension force. First, the laboratory force measurements show that, on average, the three aforementioned force terms cancel to produce a balanced line-tied equilibrium. This finding validates the laboratory force measurement techniques developed here, which were recently used to identify a dynamic toroidal field tension force that can prevent flux rope eruptions [Myers et al., Nature 528, 526 (2015)]. The verification of magnetic force balance also confirms the low-β assumption that the plasma thermal pressure is negligible in these experiments. Next, the measured force terms are directly compared to corresponding analytical expressions. While the measured and analytical forces are found to be well correlated, the low-aspect-ratio, line-tied conditions in the experiment are found to both reduce the measured hoop force and increase the measured tension force with respect to analytical

  13. Thermal structure of Venus upper atmosphere by a ground-to-thermosphere GCM: a preliminary study

    Science.gov (United States)

    Gilli, G.; Lebonnois, S.; Salmi, L.; Gonzalez-Galindo, F.; Lopez-Valverde, M. A.; Eymet, V.; Forget, F.

    2014-04-01

    We present here preliminary results of the thermal structure of the upper atmosphere of Venus simulated by a ground-to thermosphere General Circulation Model (GCM). The GCM developed at the Laboratoire de Meteorologie Dynamique (LMD) [1] has been recently improved and extended vertically from 100 to 150 km, with the inclusion of the physical processes which mostly contribute to the thermal balance in the mesosphere/thermosphere of Venus (i.e near IR heating by CO2, 15 μm thermal cooling, extreme UV heating, thermal conduction). We also focus on recent Venus Express and ground-based temperature measurements above 100 km, both at daytime and nighttime, and we interpret the observed main features with the help of model simulations. This ongoing study may indicate that both radiative and dynamical effects play a crucial role in determining the thermal structure of those upper layers of Venus atmosphere.

  14. Study on shift schedule saving energy of automatic transmission of ground vehicles

    Institute of Scientific and Technical Information of China (English)

    龚捷; 赵丁选; 陈鹰; 陈宁

    2004-01-01

    To improve ground vehicle efficiency, shift schedule energy saving was proposed for the ground vehicle automatic transmission by studying the function of the torque converter and transmission in the vehicular drivetrain. The shift schedule can keep the torque converter working in the high efficiency range under all the working conditions except in the low efficiency range on the left when the transmission worked at the lowest shift, and in the low efficiency range on the right when the transmission worked at the highest shift. The shift quality key factors were analysed. The automatic trans-mission's bench-test adopting this shift schedule was made on the automatic transmission's test-bed. The experimental results showed that the shift schedule was correct and that the shift quality was controllable.

  15. Study of ground and excited state decays in N ≈ Z Ag nuclei

    Directory of Open Access Journals (Sweden)

    Moschner K.

    2015-01-01

    Full Text Available A decay spectroscopy experiment was performed within the EURICA campaign at RIKEN in 2012. It aimed at the isomer and particle spectroscopy of excited states and ground states in the mass region below the doubly magic 100Sn. The N = Z nuclei 98In, 96Cd and 94Ag were of particular interest for the present study. Preliminary results on the neutron deficient nuclei 93Ag and 94Ag are presented. In 94Ag a more precise value for the half-life of the ground state’s superallowed Fermi transition was deduced. In addition the energy spectra of the mentioned decay could be reproduced through precise Geant4 simulations of the used active stopper SIMBA. This will enable us to extract Qβ values from the measured data. The decay of 93Ag is discussed based on the observed implantation-decay correlation events.

  16. [Medicoecological studies in the assessment of biogeochemical province in the area of a toxic waste ground].

    Science.gov (United States)

    Nagornyĭ, S V; Maĭmulov, V G; Tsybul'skaia, E A; Tigden, V P; Gorbanev, S A

    2007-01-01

    The paper presents the results of complex sanitary-and-epidemiological, toxicological-and-hygienic, and medical diagnostic studies of health and the environment, by taking into account the activity of a toxic industrial waste ground. Toxic waste burning on primitive unfiltered apparatuses was shown to lead to the formation of a biogeochemical province that is characterized by pollution of soil, bottom sediment, subsoil well water and snow with heavy metals, the components of toxic waste. Burning of waste and its storage in the open trenches resulted in ambient air pollution with organic solvents, nitric oxide and sulfur oxide had a negative impact on the health of children living at a distance of 3 km from the ground.

  17. The Logical Structure of Data in ATLAS.ti and its Advantage for Grounded Theory Studies

    Directory of Open Access Journals (Sweden)

    Agnes Mühlmeyer-Mentzel

    2011-01-01

    Full Text Available Qualitative data analysis software is quite similar regarding the fundamental steps and procedures of data analysis, but the way in which the results of the analysis are stored is different. This article focuses on the fit of grounded theory methodology (GTM and a network-like storage, as is used in ATLAS.ti. Using data from an ongoing research study as an example, a description is provided of how the analytical steps of GTM are implemented in ATLAS.ti and how results are stored as a net of nodes. This code net represents the developed "grounded theory" as structured conceptualized information. Exported as an XML file the code net can be used in other applications by other researchers. This has the potential to support data quality and scientific cooperation between qualitative researchers. URN: http://nbn-resolving.de/urn:nbn:de:0114-fqs1101325

  18. Study on shift schedule saving energy of automatic transmission of ground vehicles

    Institute of Scientific and Technical Information of China (English)

    龚捷; 赵丁选; 陈鹰; 陈宁

    2004-01-01

    To improve ground vehicle efficiency,shift schedule energy saving was proposed for the ground vehicle automatic transmission by studying the function of the torque converter and transmission in the vehicular drivetrain.The shift schedule can keep the torque converter working in the high efficiency range under all the working conditions except in the low efficiency range on the left when the transmission worked at the lowest shift,and in the low efficiency range on the right when the transmission worked at the highest shift.The shift quality key factors were analysed.The automatic transmission's bench-test adopting this shift schedule was made on the automatic transmission's test-bed.The experimental results showed that the shift schedule was correct and that the shift quality was controllable.

  19. Heat as a tool for studying the movement of ground water near streams

    Science.gov (United States)

    Stonestrom, David A.; Constantz, Jim

    2003-01-01

    and practical constraints. As an alternative, naturally occurring variations in temperature can be used to track (or trace) the heat carried by flowing water. The hydraulic transport of heat enables its use as a tracer. Differences between temperatures in the stream and surrounding sediments are now being analyzed to trace the movement of ground water to and from streams. As shown in the subsequent chapters of this circular, tracing the transport of heat leads to a better understanding of the magnitudes and mechanisms of stream/ground-water exchanges, and helps quantify the resulting effects on stream and streambed temperatures. Chapter 1 describes the general principals and procedures by which the natural transport of heat can be utilized to infer the movement of subsurface water near streams. This information sets the foundation for understanding the advanced applications in chapters 2 through 8. Each of these chapters provides a case study, using heat tracing as a tool, of interactions between surface water and ground water for a different location in the western United States. Technical details of the use of heat as an environmental tracer appear in appendices.

  20. An Experimental Study of Several Special Issues Regarding the Ice Force on Conical Structures

    Institute of Scientific and Technical Information of China (English)

    史庆增; 宋安; 黄焱

    2002-01-01

    The effect of the cone spacing of a conical structure on the ice force is studied by model experiments. The ice force reduction coefficient presented in this paper expresses the relationship between the ice force and the arrangement of cones. The experiments prove that the mode of the ice failure before the boundary of upward-downward bending cone (UDBC) is crushing. A conclusion can also be drawn from the experiments that the ice force on the boundary of UDBC is by far less than that on a vertical pile with the same diameter. Moreover, the ice force frequencies on upright and inverted cones are obtained under the field condition of the platform JZ20-2, respectively. The results show that the alternation of the ice force on UDBC can hardly induce resonance of platform JZ20-2.

  1. Structural Studies of Metastable and Ground State Vortex Lattice Domains in MgB2

    Science.gov (United States)

    de Waard, E. R.; Kuhn, S. J.; Rastovski, C.; Eskildsen, M. R.; Leishman, A.; Dewhurst, C. D.; Debeer-Schmitt, L.; Littrell, K.; Karpinski, J.; Zhigadlo, N. D.

    2015-03-01

    Small-angle neutron scattering (SANS) studies of the vortex lattice (VL) in the type-II superconductor MgB2 have revealed an unprecedented degree of metastability that is demonstrably not due to vortex pinning, [C. Rastovski et al . , Phys. Rev. Lett. 111, 107002 (2013)]. Application of an AC magnetic field to drive the VL to the ground state revealed a two-step power law behavior, indicating a slow nucleation of ground state domains followed by a faster growth. The dependence on the number of applied AC cycles is reminiscent of jamming of soft, frictionless spheres. Here, we report on detailed structural studies of both metastable and ground state VL domains. These include measurements of VL correlation lengths as well as spatially resolved SANS measurements showing the VL domain distribution within the MgB2 single crystal. We discuss these results and how they may help to resolve the mechanism responsible for stabilizing the metastable VL phases. This work is supported by the U.S. Department of Energy, Office of Basic Energy Sciences under Award DE-FG02-10ER46783.

  2. A Study of Ion Drag for Ground and Microgravity Dusty Plasma Experiments

    Science.gov (United States)

    Hall, Taylor; Thomas, Edward

    2015-11-01

    This presentation presents the results of a recent study of the interaction between charged dust particles and plasma ions through the ion drag force in a dc glow discharge plasma. Measurements of the dust particles motion are carried out using Particle Image Velocimetry (PIV). When an electrostatic perturbation is applied to the dust cloud, the particle motion, in response to the perturbation, is shown to reverse direction as the gas pressure is increased. An analysis of the dust particle motion and background plasma parameters suggests that there is a competition between the ion drag and electric forces on the particles. These forces are calculated for a range of pressures using detailed measurements of the plasma parameters carried out by a single Langmuir probe. The analysis of these measurements suggests that a change in the relative magnitude of the Coulomb collision ion drag compared to the electric force is a probable explanation for the observed reversal of direction of motion as the neutral gas pressure is increased. The application of these results to microgravity studies of dusty plasmas will be discussed. Support provided by NASA-JPL (JPL-RSA 1471384).

  3. Estimation of regression laws for ground motion parameters using as case of study the Amatrice earthquake

    Science.gov (United States)

    Tiberi, Lara; Costa, Giovanni

    2017-04-01

    The possibility to directly associate the damages to the ground motion parameters is always a great challenge, in particular for civil protections. Indeed a ground motion parameter, estimated in near real time that can express the damages occurred after an earthquake, is fundamental to arrange the first assistance after an event. The aim of this work is to contribute to the estimation of the ground motion parameter that better describes the observed intensity, immediately after an event. This can be done calculating for each ground motion parameter estimated in a near real time mode a regression law which correlates the above-mentioned parameter to the observed macro-seismic intensity. This estimation is done collecting high quality accelerometric data in near field, filtering them at different frequency steps. The regression laws are calculated using two different techniques: the non linear least-squares (NLLS) Marquardt-Levenberg algorithm and the orthogonal distance methodology (ODR). The limits of the first methodology are the needed of initial values for the parameters a and b (set 1.0 in this study), and the constraint that the independent variable must be known with greater accuracy than the dependent variable. While the second algorithm is based on the estimation of the errors perpendicular to the line, rather than just vertically. The vertical errors are just the errors in the 'y' direction, so only for the dependent variable whereas the perpendicular errors take into account errors for both the variables, the dependent and the independent. This makes possible also to directly invert the relation, so the a and b values can be used also to express the gmps as function of I. For each law the standard deviation and R2 value are estimated in order to test the quality and the reliability of the found relation. The Amatrice earthquake of 24th August of 2016 is used as case of study to test the goodness of the calculated regression laws.

  4. Exploring Sources of Variation in Studies of Knowledge Structure Coherence: Comparing Force Meanings and Force Meaning Consistency across Two Turkish Cities

    Science.gov (United States)

    Clark, Douglas B.; Menekse, Muhsin; Ozdemir, Gokhan; D'Angelo, Cynthis M.; Price Schleigh, Sharon

    2014-01-01

    Substantial variation has been observed across an international series of studies examining the consistency of students' explanations of force and the most common meanings of force apparent in those explanations. On the surface, the variations among studies might be attributed to differences at the national level, but the studies also demonstrate…

  5. Exploring Sources of Variation in Studies of Knowledge Structure Coherence: Comparing Force Meanings and Force Meaning Consistency across Two Turkish Cities

    Science.gov (United States)

    Clark, Douglas B.; Menekse, Muhsin; Ozdemir, Gokhan; D'Angelo, Cynthis M.; Price Schleigh, Sharon

    2014-01-01

    Substantial variation has been observed across an international series of studies examining the consistency of students' explanations of force and the most common meanings of force apparent in those explanations. On the surface, the variations among studies might be attributed to differences at the national level, but the studies also demonstrate…

  6. Ground Truth Studies - A hands-on environmental science program for students, grades K-12

    Science.gov (United States)

    Katzenberger, John; Chappell, Charles R.

    1992-01-01

    The paper discusses the background and the objectives of the Ground Truth Studies (GTSs), an activity-based teaching program which integrates local environmental studies with global change topics, utilizing remotely sensed earth imagery. Special attention is given to the five key concepts around which the GTS programs are organized, the pilot program, the initial pilot study evaluation, and the GTS Handbook. The GTS Handbook contains a primer on global change and remote sensing, aerial and satellite images, student activities, glossary, and an appendix of reference material. Also described is a K-12 teacher training model. International participation in the program is to be initiated during the 1992-1993 school year.

  7. Exact integral constraint requiring only the ground-state electron density as input on the exchange-correlation force - partial differential(V)(xc)(r)/partial differential(r) for spherical atoms.

    Science.gov (United States)

    March, N H; Nagy, A

    2008-11-21

    Following some studies of integral(n)(r)inverted DeltaV(r)dr by earlier workers for the density functional theory (DFT) one-body potential V(r) generating the exact ground-state density, we consider here the special case of spherical atoms. The starting point is the differential virial theorem, which is used, as well as the Hiller-Sucher-Feinberg [Phys. Rev. A 18, 2399 (1978)] identity to show that the scalar quantity paralleling the above vector integral, namely, integral(n)(r) partial differential(V)(r)/partial differential(r)dr, is determined solely by the electron density n(0) at the nucleus for the s-like atoms He and Be. The force - partial differential(V)/ partial differential(r) is then related to the derivative of the exchange-correlation potential V(xc)(r) by terms involving only the external potential in addition to n(r). The resulting integral constraint should allow some test of the quality of currently used forms of V(xc)(r). The article concludes with results from the differential virial theorem and the Hiller-Sucher-Feinberg identity for the exact many-electron theory of spherical atoms, as well as for the DFT for atoms such as Ne with a closed p shell.

  8. Study on the Performance of a Ground Source Heat Pump System Assisted by Solar Thermal Storage

    Directory of Open Access Journals (Sweden)

    Yu Jin Nam

    2015-11-01

    Full Text Available A ground source heat pump system (GSHPS utilizes a relatively stable underground temperature to achieve energy-saving for heating and cooling in buildings. However, continuous long-term operation will reduce the soil temperature in winter, resulting in a decline in system performance. In this research, in order to improve the system performance of a GSHPS, a ground heat pump system integrated with solar thermal storage was developed. This solar-assisted ground heat pump system (SAGHPS can both maintain the balance of the soil temperature effectively and achieve higher system performance than the conventional system. In this paper, in order to examine the characteristics of the system, a dynamic simulation was conducted under various conditions. The results of our case study provide specific operation data such as heat exchange rate, heat source temperature, and heat pump COP. As a result, the heat pump COP of SAGHPS was 4.7%, 9.3% higher than that of the GSHPS.

  9. A Grounded Theory Study on Journeying through the Shield to Sacredness: "Ni'hokaa' Diyin Dine'e Idliini Dolzin"

    Science.gov (United States)

    Garrity, Geraldine

    2013-01-01

    In doing a grounded theory study, the researcher does not identify a hypothesis, formulate research questions, or state a specific problem at the beginning of the research. Grounded theory research begins with data collection, minimizing preconceptions about outcomes to the greatest extent possible. I began my research with this attitude of not…

  10. Areal studies aid protection of ground-water quality in Illinois, Indiana, and Wisconsin

    Science.gov (United States)

    Mills, Patrick C.; Kay, Robert T.; Brown, Timothy A.; Yeskis, Douglas J.

    1999-01-01

    In 1991, the U.S. Geological Survey, in cooperation with the U.S. Environmental Protection Agency, initiated studies designed to characterize the ground-water quality and hydrogeology in northern Illinois, and southern and eastern Wisconsin (with a focus on the north-central Illinois cities of Belvidere and Rockford, and the Calumet region of northeastern Illinois and northwestern Indiana). These areas are considered especially susceptible to ground-water contamination because of the high density of industrial and waste-disposal sites and the shallow depth to the unconsolidated sand and gravel aquifers and the fractured, carbonate bedrock aquifers that underlie the areas. The data and conceptual models of ground-water flow and contaminant distribution and movement developed as part of the studies have allowed Federal, State, and local agencies to better manage, protect, and restore the water supplies of the areas. Water-quality, hydrologic, geologic, and geophysical data collected as part of these areal studies indicate that industrial contaminants are present locally in the aquifers underlying the areas. Most of the contaminants, particularly those at concentrations that exceeded regulatory water-quality levels, were detected in the sand and gravel aquifers near industrial or waste-disposal sites. In water from water-supply wells, the contaminants that were present generally were at concentrations below regulatory levels. The organic compounds detected most frequently at concentrations near or above regulatory levels varied by area. Trichloroethene, tetrachloroethene, and 1,1,1-trichloroethane (volatile chlorinated compounds) were most prevalent in north-central Illinois; benzene (a petroleum-related compound) was most prevalent in the Calumet region. Differences in the type of organic compounds that were detected in each area likely reflect differences in the types of industrial sites that predominate in the areas. Nickel and aluminum were the trace metals

  11. The 2 Degrees of Freedom facility in Firenze for the study of weak forces

    Science.gov (United States)

    Marconi, L.; Stanga, R.; Lorenzini, M.; Grimani, C.; Bassan, M.; Pucacco, G.; Di Fiore, L.; De Rosa, R.; Garufi, F.; Milano, L.

    2010-05-01

    The LISA test-mass (TM) is sensitive to weak forces along all 6 Degrees of Freedom (DoFs). Extensi ve ground test ing is required in order to evaluate the influence of cross-talks of read-outs and actuators operating on different DoFs. To best represent the flight conditions, we developed in Firenze a facility with 2 soft DoFs. Using this facility we measure the forces and stiffnesses acting simultaneously along the 2 soft DoFs, and, more specifically, we will be able to de b ug residual couplings between the TM and the capacitive position sensor that reads the TM position, and to measure actuation cross talks with closed feedback loop. The facility is now ready, and here we report on the co mmi ssioning test s, and on the first measurements.

  12. Emergency Nursing Experiences in Assisting People With Suicidal Behavior: A Grounded Theory Study.

    Science.gov (United States)

    Vedana, Kelly Graziani Giacchero; Magrini, Daniel Fernando; Miasso, Adriana Inocenti; Zanetti, Ana Carolina Guidorizzi; de Souza, Jacqueline; Borges, Tatiana Longo

    2017-08-01

    To understand emergency nursing experiences in assisting people with suicidal behavior. Grounded theory study with symbolic interactionism conducted in 2015 to 2016 in Brazil with 19 nurses. Assistance for people with suicidal behavior is critical, challenging, evokes different feelings and requires knowledge, skills and emotional control. Nurses did not feel prepared or supported, and identified recurrent gaps and problems. Nurses occupied a limited role, restricted to attending to physical needs. They predominantly manifested opposition, judgments and incomprehension about patients. This study presents key elements to be addressed in interventions and investigations regarding nursing support, training and supervision. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. A Study of Bite Force and Various Variables in Children Segregated by Angle's Classification

    Science.gov (United States)

    Sandhu, Navreet; Kashyap, Rita

    2012-01-01

    ABSTRACT The stomatographic system has been studied by several researchers, yet it is still unclear, weather a genetically determined facial morphology decides the strength of masticatory muscles,1 or weather a strong musculature influences the form of the face. This formed the basis of present study to relate muscle activity with various malocclusions. Thus, 60 samples of younger age group were divided according to Angle classification and maximum bite force was recorded among the groups. Newly designed bite force recorder was used for recording bite force at molar and at incisal region. Influence of various independent variables like gender, overjet and overbite of the subjects on the bite force was also checked. It was concluded that maximum bite force at intercuspal position (molar) and anterior bite position (incisal) were not significantly different between normal, class I, class II div 1 and class III malocclusion groups. There was no significant correlation between incisal bite force and overjet or overbite, but there was a highly significant difference (p < 0.001) between the males and females for maximum bite force at intercuspal position, with males biting harder than the females. How to cite this article: Singh S, Sandhu N, Kashyap R. A Study of Bite Force and Various Variables in Children Segregated by Angle's Classification. Int J Clin Pediatr Dent 2012;5(2):118-123. PMID:25206150

  14. A study of design spectra based on attenuation relationship of ground motion

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    @@In recent years, more and more studies are focused on the performance in seismic design instead of the strength of structures. People have realized that the structure deformation (displacement) can describe the damage more properly and directly than the strength (force). The displacement design spectra need to be constructed within more wide range of the period and the damping for the displacement-based seismic design.

  15. Forces in initial archwires during leveling and aligning: An in-vitro study

    Science.gov (United States)

    Reddy, Rajesh Kumar; Katari, Pavan K.; Bypureddy, Tarun T.; Anumolu, Venkata Naga Sri Harsha; Kartheek, Yenugupalli; Sairam, Nemala. R. V.

    2016-01-01

    Aim: This in-vitro study measured the force deflection behavior of selected initial alignment archwires by conducting three-point bending tests under controlled tests. The study tested three wire designs, namely, co-axial multistranded stainless steel wires, nickel–titanium, and copper–nickel–titanium archwires. Materials and Methods: The archwires were ligated to a specially designed metal jig, simulating the arch. A testing machine (Instron) recorded activation and deactivation forces of different deflections at 37°C. Forces on activation and deactivation were compared by one-way analysis of variance (ANOVA). Results: Significant differences (P < 0.05) in activation and deactivation forces were observed among the tested wires. The co-axial multistranded wire had the lowest mean activation and deactivation forces, whereas conventional nickel–titanium wires had more mean activation and deactivation forces at different deflections. Conclusion: The activation and deactivation forces were higher for nickel–titanium followed by copper–nickel titanium and co-axial wires. The amount of percentage force loss was more for co-axial wire, indicating that these wires are not ideal for initial leveling and aligning. PMID:27891306

  16. An Archaeological Curation-Needs Assessment for Fort Irwin, Naval Air Station, North Island, Edwards Air Force Base, Marine Corps Air-Ground Combat Center, Twentynine Palms

    National Research Council Canada - National Science Library

    Trimble, Michael

    1997-01-01

    .... Louis District, conducted an investigation of all archaeological materials and associated records in the care of NAS North Island, Edwards Air Force Base, Fort Irwin, and MCAGCC Twentynine Palms...

  17. Interior noise control ground test studies for advanced turboprop aircraft applications

    Science.gov (United States)

    Simpson, Myles A.; Cannon, Mark R.; Burge, Paul L.; Boyd, Robert P.

    1989-01-01

    The measurement and analysis procedures are documented, and the results of interior noise control ground tests conducted on a DC-9 aircraft test section are summarized. The objectives of these tests were to study the fuselage response characteristics of treated and untreated aircraft with aft-mount advanced turboprop engines and to analyze the effectiveness of selected noise control treatments in reducing passenger cabin noise on these aircraft. The results of fuselage structural mode surveys, cabin cavity surveys and sound intensity surveys are presented. The performance of various structural and cabin sidewall treatments is assessed, based on measurements of the resulting interior noise levels under simulated advanced turboprop excitation.

  18. Ground roll attenuation using a curvelet-SVD filter: a case study from the west of Iran

    Science.gov (United States)

    Boustani, Bahareh; Torabi, Siyavash; Javaherian, Abdorahim; Mortazavi, Seyed Ahmad

    2013-10-01

    In reflection seismology, a ground roll is a low frequency, low velocity and high amplitude surface wave. It usually has stronger amplitude than reflections, and masks valuable information carried by signals. Many filters in different domains have been used for ground roll attenuation such as tau-p and f-k filters. Recently, in many studies, the curvelet transform has been used for ground roll attenuation. The curvelet transform creates a good separation between ground roll and reflections in dip and frequency, especially in high frequency subbands. In this paper, based on the adaptive curvelet filter, a new method is introduced through a combination of the adaptive curvelet and adaptive singular value decomposition (ASVD) filters and is called a curvelet-SVD filter. In this filter, the subbands in a curvelet domain are divided into three categories based on the ground roll energy in each subband. These categories are subbands (1) with high energy containing only ground roll, (2) with medium energy that contains both ground roll and reflections, and (3) with low energy containing only reflections. The category that contains only ground roll will be muted, as in common usage of the adaptive curvelet filter. If the category that contains both ground roll and reflections is unchanged, part of the ground roll will not be attenuated. If this category is muted, part of the reflections will be damaged. To overcome this problem, ASVD is applied to attenuate ground roll in the subbands of this category. The category that contains only reflections will not be touched. This filter was applied to a synthetic and to a real data set from the west of Iran. The synthetic data contained dispersed and aliased ground roll. A curvelet-SVD filter could attenuate dispersed ground roll but it could not completely attenuate aliased ground roll. Because of the damage to the reflections, the energy threshold for applying ASVD in the curvelet domain could not be selected any lower. In real

  19. Study on Characteristics of Hydraulic Servo System for Force Control of Hydraulic Robots

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyo-gon; Han, Changsoo [Hanyang University, Seoul (Korea, Republic of); Lee, Jong-won [Korea University of Science and Technology, Seoul (Korea, Republic of); Park, Sangdeok [Korea Institute of Industrial Technology, Seoul (Korea, Republic of)

    2015-02-15

    Because a hydraulic actuator has high power and force densities, this allows the weight of the robot's limbs to be reduced. This allows for good dynamic characteristics and high energy efficiency. Thus, hydraulic actuators are used in some exoskeleton robots and quadrupedal robots that require high torque. Force control is useful for robot compliance with a user or environment. However, force control of a hydraulic robot is difficult because a hydraulic servo system is highly nonlinear from a control perspective. In this study, a nonlinear model was used to develop a simulation program for a hydraulic servo system consisting of a servo valve, transmission lines, and a cylinder. The problems and considerations with regard to the force control performance for a hydraulic servo system were investigated. A force control method using the nonlinear model was proposed, and its effect was evaluated with the simulation program.

  20. EXPERIMENTAL STUDY ON TOTAL UPLIFT FORCES OF WAVES ON HORIZONTAL PLATES

    Institute of Scientific and Technical Information of China (English)

    ZHOU Yi-ren; CHEN Guo-ping; WANG Deng-ting

    2004-01-01

    The total uplift forces of waves acting on hori zontal plates are the important basis for the design of maritime hollow-trussed structures. In this paper, an experimental study on the total uplift forces of waves on horizontal plates was conducted by a series of model tests. The results show that the maximum total uplift forces do not necessarily occur with the maximum impact pressure intensity synchronously.On the basis of the test results, formation mechanism of the total uplift forces of waves as well as its influencing factors were analyzed in detail, and an equation for calculation of the maximum total uplift forces of waves on plates was put forward. Lots of test data shows the present equation is in good agreement with the test results.

  1. Force-controlled balance perturbations associated with falls in older people: a prospective cohort study.

    Directory of Open Access Journals (Sweden)

    Daina L Sturnieks

    Full Text Available Balance recovery from an unpredictable postural perturbation can be a challenging task for many older people and poor recovery could contribute to their risk of falls. This study examined associations between responses to unpredictable perturbations and fall risk in older people. 242 older adults (80.0 ± 4.4 years underwent assessments of stepping responses to multi-directional force-controlled waist-pull perturbations. Participants returned monthly falls calendars for the subsequent 12 months. Future falls were associated with lower force thresholds for stepping in the posterior and lateral but not anterior directions. Those with lower posterior force thresholds for stepping were 68% more likely to fall at home than those with higher force thresholds for stepping. These results suggest that amount of force that can be withstood following an unpredictable balance perturbation predicts future falls in community-dwelling older adults. Perturbations in the posterior direction best discriminated between future fallers and non-fallers.

  2. A validation study of a new instrument for low cost bite force measurement.

    Science.gov (United States)

    Testa, Marco; Di Marco, Anna; Pertusio, Raffaele; Van Roy, Peter; Cattrysse, Erik; Roatta, Silvestro

    2016-10-01

    Quantitative assessment of force in masticatory muscles is not a routine clinical test, probably due to the lack of an "easy-to-use" device. Aim of this study is (1) to present a low cost bite force instrument located in a custom-made housing, designed to guarantee a comfortable and effective bite action, (2) to evaluate its mechanical characteristics, in order to implement it in clinical settings and in experimental setups. Linearity, repeatability and adaptation over time were assessed on a set of four different sensors in bare and housed condition. Application of the housing to the transducer may appreciably alter the transducer's response. Calibration of the housed transducer is thus necessary in order to correctly record real bite force. This solution may represent a low cost and reliable option for biting force measurement and objective assessment of individual force control in the scientific and clinical setting.

  3. Grounded Theory in studies on health of the elderly: integrative review

    Directory of Open Access Journals (Sweden)

    Karina Oliveira de Mesquita

    2015-12-01

    Full Text Available : It is an integrative literature review in order to analyze national scientific production on the health of the elderly who used the Grounded Theory (DFT or Grounded Theory. We conducted a search in the Virtual Library databases Health considering all publications until March 2015. The search resulted in the selection of 11 articles by keywords: Grounded Theory and Aging Health. A Grounded Theory has contributed in the development of theories and meanings of experiences.  

  4. Study on the quality of ground, spring and river waters in south-east Serbia

    Directory of Open Access Journals (Sweden)

    Stojanović Zorica S.

    2015-01-01

    Full Text Available The study deals with mineral characterization of natural waters from South-East Serbia. The contents of aluminium, arsenic, calcium, cadmium, cobalt, chromium, cooper, iron, potassium, magnesium, manganese, sodium, nickel, lead and zinc were analysed in spring, ground and river waters by inductively coupled plasma-atomic emission spectrometry (ICP-AES technique. The study area was in the Southern Serbia, and included slopes of Rtanj, Ozren, Bukovik, Vrdenik and Čemernik mountains, and the valley of South Morava. Obtained contents were compared with Serbian regulations on the quality of water for human use, and directive of World Health Organization (WHO for maximum allowed concentrations of chemical substances. High contents of macro-elements, namely calcium, magnesium and potassium, were detected in several spring and ground water samples which are believed to be due to direct influence of rock minerals. Some water samples contained iron, manganese and copper in concentration up to 84.2 μg dm-3, 8.10 μg dm-3 and 14.9 μg dm-3, respectively, but within the permissible limits. Other heavy metals were not detected in analysed samples. Based on the derived results, tested ground and spring water samples have significant potential to be used as sources for the production of bottled water, but further investigations are necessary. Additional investigations have to be focused on complete physical, chemical and microbiological assessments of water resources. Systematic hydrogeological assessment also should be performed in all seasons. In the meantime, precautionary measures should be immediately taken to protect and preserve these water resources. [Projekat Ministarstva nauke Republike Srbije, br. TR 31014

  5. Review of seismicity and ground motion studies related to development of seismic design at SRS

    Energy Technology Data Exchange (ETDEWEB)

    Stephenson, D.E. [Westinghouse Savannah River Co., Aiken, SC (United States); Acree, J.R. [Westinghouse Environmental and Geotechnical Services, Inc., Columbia, SC (United States)

    1992-08-01

    The NRC response spectra developed in Reg. Guide 1.60 is being used in the studies related to restarting of the existing Savannah River Site (SRS) reactors. Because it envelopes all the other site specific spectra which have been developed for SRS, it provides significant conservatism in the design and analysis of the reactor systems for ground motions of this value or with these probability levels. This spectral shape is also the shape used for the design of the recently licensed Vogtle Nuclear Station, located south of the Savannah River from the SRS. This report provides a summary of the data base used to develop the design basis earthquake. This includes the seismicity, rates of occurrence, magnitudes, and attenuation relationships. A summary is provided for the studies performed and methodologies used to establish the design basis earthquake for SRS. The ground motion response spectra developed from the various studies are also summarized. The seismic hazard and PGA`s developed for other critical facilities in the region are discussed, and the SRS seismic instrumentation is presented. The programs for resolving outstanding issues are discussed and conclusions are presented.

  6. Case study for ARRA-funded ground-source heat pump (GSHP) demonstration at Oakland University

    Energy Technology Data Exchange (ETDEWEB)

    Im, Piljae [ORNL; Liu, Xiaobing [ORNL

    2015-09-01

    High initial costs and lack of public awareness of ground-source heat pump (GSHP) technology are the two major barriers preventing rapid deployment of this energy-saving technology in the United States. Under the American Recovery and Reinvestment Act (ARRA), 26 GSHP projects have been competitively selected and carried out to demonstrate the benefits of GSHP systems and innovative technologies for cost reduction and/or performance improvement. This paper highlights the findings of a case study of one of the ARRA-funded GSHP demonstration projects, a ground-source variable refrigerant flow (GS-VRF) system installed at the Human Health Building at Oakland University in Rochester, Michigan. This case study is based on the analysis of measured performance data, maintenance records, construction costs, and simulations of the energy consumption of conventional central heating, ventilation, and air-conditioning (HVAC) systems providing the same level of space conditioning as the demonstrated GS-VRF system. The evaluated performance metrics include the energy efficiency of the heat pump equipment and the overall GS-VRF system, pumping performance, energy savings, carbon emission reductions, and cost-effectiveness of the GS-VRF system compared with conventional HVAC systems. This case study also identified opportunities for reducing uncertainties in the performance evaluation, improving the operational efficiency, and reducing the installed cost of similar GSHP systems in the future.

  7. Comparative study of ground water treatment plants sludges to remove phosphorous from wastewater.

    Science.gov (United States)

    Bal Krishna, K C; Aryal, Ashok; Jansen, Troy

    2016-09-15

    Alum- and iron-based sludge obtained from water treatment plant produced during a unit treatment process (coagulation and flocculation) have been widely tested as a low-cost adsorbent to remove phosphorous (P) from wastewater. However, the effectiveness of iron-based sludge generated from the oxidation of iron which naturally occurs in the ground water has not been investigated. Moreover, influences of dominant metals ions comprised in the treatment plants sludges on P adsorption capacity and rate from wastewater are not yet known. This study, therefore, employed four different groundwater treatment plants sludges iron-based (from the oxidation of iron) and alum-based (from coagulation and flocculation process) to determine their P adsorption capacities and adsorption rates from the synthetic wastewater (SWW) and secondary effluent wastewater (SEWW). Although metals ions concentrations were the highest in the iron-based sludge amongst the sludge used in this study, it appeared to have the lowest P adsorption capacity and adsorption rate. A good correlation between aluminium to iron mass ratio and adsorption capacity for both types of waters were noted. However, a poor relation between aluminium to iron mass ratio and adsorption rates for the SEWW was observed. Further, the tested sludges were found to have a better P removal efficiency and adsorption capacity from the SEWW than from the SWW. Thus, this study demonstrates the ground water treatment plants sludges could be a low cost and effective adsorbent in removing P from wastewater. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. This too shall pass: a grounded theory study of Filipino cancer survivorship.

    Science.gov (United States)

    de Guzman, Allan B; Jimenez, Benito Christian B; Jocson, Kathlyn P; Junio, Aileen R; Junio, Drazen E; Jurado, Jasper Benjamin N; Justiniano, Angela Bianca F

    2013-03-01

    Considering the paucity of studies dealing with the holistic aspect of the cancer experience, this grounded theory study seeks to conceptualize the process of cancer survivorship among Filipinos. Twenty-seven Filipino cancer survivors were purposively selected, and a two-part instrument, specifically robotfoto and focus group interviews, was used to gather data. The Glaserian method of grounded theory analysis was used, and extended texts were analyzed inductively via a dendrogram. Member checking and correspondence were observed to validate the surfacing stages, leading to the conceptualization of a theoretical model termed as the Ribbon of Cancer Survivorship. The said model describes the trifling (living before), transfusing (accepting the reality), transforming (being strong), and transcending (living beyond) phases of cancer survivorship. Ten interesting substages were also identified, namely: tainting, desolating, disrupting, and embracing for the transfusing phase; tormenting, distressing, awakening, and transfiguring for the transforming phase, and trembling and enlivening for the transcending phase. The resulting theoretical model has clearly and successfully described the entire process of cancer survivorship among Filipinos. It is hoped that the model be used as a reference for future studies about cancer survivorship and as a guide for nurses in providing a more empathetic care among cancer patients.

  9. Development of forced degradation and stability indicating studies of drugs-A review

    Institute of Scientific and Technical Information of China (English)

    Blessy Mn; Ruchi D. Patel; Prajesh N. Prajapati; Y.K. Agrawal

    2014-01-01

    Forced degradation is a degradation of new drug substance and drug product at conditions more severe than accelerated conditions. It is required to demonstrate specificity of stability indicating methods and also provides an insight into degradation pathways and degradation products of the drug substance and helps in elucidation of the structure of the degradation products. Forced degradation studies show the chemical behavior of the molecule which in turn helps in the development of formulation and package. In addition, the regulatory guidance is very general and does not explain about the performance of forced degradation studies. Thus, this review discusses the current trends in performance of forced degradation studies by providing a strategy for conducting studies on degradation mechanisms and also describes the analytical methods helpful for development of stability indicating method.

  10. A microfabricated magnetic force transducer-microaspiration system for studying membrane mechanics

    Science.gov (United States)

    Stark, D. J.; Killian, T. C.; Raphael, R. M.

    2011-10-01

    The application of forces to cell membranes is a powerful method for studying membrane mechanics. To apply controlled dynamic forces on the piconewton scale, we designed and characterized a microfabricated magnetic force transducer (MMFT) consisting of current-carrying gold wires patterned on a sapphire substrate. The experimentally measured forces applied to paramagnetic and ferromagnetic beads as a function of applied current agree well with theoretical models. We used this device to pull tethers from microaspirated giant unilamellar vesicles and measure the threshold force for tether formation. In addition, the interlayer drag coefficient of the membrane was determined from the tether-return velocity under magnetic force-free conditions. At high levels of current, vesicles expanded as a result of local temperature changes. A finite element thermal model of the MMFT provided absolute temperature calibration, allowing determination of the thermal expansivity coefficient of stearoyl-oleoyl-phosphatidycholine vesicles (1.7 ± 0.4 × 10-3 K-1) and characterization of the Joule heating associated with current passing through the device. This effect can be used as a sensitive probe of temperature changes on the microscale. These studies establish the MMFT as an effective tool for applying precise forces to membranes at controlled rates and quantitatively studying membrane mechanical and thermo-mechanical properties.

  11. Coordinated Ground- and Space-based Multispectral Campaign to Study Equatorial Spread-F Formation

    Science.gov (United States)

    Finn, S. C.; Geddes, G.; Aryal, S.; Stephan, A. W.; Budzien, S. A.; Duggirala, P. R.; Chakrabarti, S.; Valladares, C.

    2016-12-01

    We present a concept for a multispectral campaign using coordinated data from state-of-the-art instruments aboard the International Space Station (ISS) and multiple ground-based spectrometers and digisondes deployed at low-latitudes to study the formation and development of Equatorial Spread-F (ESF). This extended observational campaign utilizes ultraviolet, visible, and radio measurements to develop a predictive capability for ESF and to study the coupling of the ionosphere-thermosphere (I-T) system during geomagnetically quiet and disturbed times. The ground-based instruments will be deployed in carefully chosen locations in the American and Indian sectors while the space-based data will provide global coverage spanning all local times and longitudes within ±51° geographic latitudes. The campaign, over an extended period covering a range of geophysical conditions, will provide the extensive data base necessary to address the important science questions. The space-based instrument suite consists of the Limb-imaging Ionospheric and Thermospheric Extreme-ultraviolet Spectrograph (LITES) and the GPS Radio Occultation and Ultraviolet Photometry-Colocated (GROUP-C) instruments, scheduled to launch to the ISS in November 2016. LITES is a compact imaging spectrograph for remote sensing of the upper atmosphere and ionosphere from 60 to 140nm and GROUP-C has a nadir-viewing FUV photometer. The ground-based instruments to be deployed for this campaign are three high-resolution imaging spectrographs capable of continuous round-the-clock airglow observations: Multiwavelength Imaging Spectrograph using Echelle grating (MISE) in India and two High Throughput and Multi-slit Imaging Spectrographs (HiT&MIS) to be deployed in Colombia and Argentina, the Low-Latitude Ionosphere Sensor Network (LISN), and the Global Ionospheric Radio Observatory (GIRO) digisondes network. We present data from the ground-based instruments, initial results from the LITES and GROUP-C instruments on

  12. A STUDY ON APPLICABILITY OF GROUND RESPONSE ACCELERATION METHOD TO DEEP VERTICAL UNDERGROUND STRUCTURES

    Science.gov (United States)

    Matsumoto, Mai; Shiba, Yukio; Watanabe, Kazuaki

    This paper discusses the applicability of ground response acceleration method to seismic analysis for deep vertical underground structures. To examine the applicability, an analysis of relationships between response of ground and the shaft was conducted. It was found from the analysis that vertical axial stress of the shaft was not correspond with shear stress of ground. Accordingly, it was concluded that the axial stress was not evaluated correctly by the existing method. Therefore, to extend the applicability of the method, ground responses correlated with the axial stress were analyzed and a new method using these ground responses was proposed.

  13. Ground nesting in recultivated forest habitats - a study with artificial nests

    Energy Technology Data Exchange (ETDEWEB)

    Purger, J.J.; Meszaros, L.A.; Purger, D. [University of Pecs, Pecs (Hungary). Faculty of Science

    2004-01-01

    The study was carried out in the outskirts of the town of Pecs (southern Hungary) in a recultivated former coal mine. Bordered by Turkey Oak forests, this open area forms a wedge-shaped clearing in that woodland. Since trees and taller shrubs are rare in the area, it is mainly ground nesting bird species that occur in the clearing. In order to discover whether it is more advantageous to nest in the recultivated area (clearing) than in the nearby forest or at its edges, 150 artificial ground nests were constructed. On 7 May 2002, one quail egg and a plasticine egg of similar size were placed in each of the artificial nests. After a week it was found that 24% of nests in the clearing, 30% of those in the forest edge, and 44% of the ones inside the forest had suffered depredation. The proportions of damaged plasticine and quail eggs inside the forest and at the forest edge were similar, whereas the quail eggs in the clearings were significantly less damaged than plasticine eggs. Of all the experimental eggs, significantly more plasticine eggs (29%) were damaged than quail eggs (17%), which suggests that small-bodied predators are unable to break the quail eggs. 18% of the plasticine eggs attacked, and 72% of the quail eggs attacked were removed from the nest by the predator. Among the predators, small mammals were dominant in the clearing and inside the forest, and birds at the forest edge. Based on the predation of quail eggs, the survival chances of ground nests in the clearing are greater than at the forest edge or inside the forest.

  14. Theoretical study of the ground-state structures and properties of niobium hydrides under pressure

    Science.gov (United States)

    Gao, Guoying; Hoffmann, Roald; Ashcroft, N. W.; Liu, Hanyu; Bergara, Aitor; Ma, Yanming

    2013-11-01

    As part of a search for enhanced superconductivity, we explore theoretically the ground-state structures and properties of some hydrides of niobium over a range of pressures and particularly those with significant hydrogen content. A primary motivation originates with the observation that under normal conditions niobium is the element with the highest superconducting transition temperature (Tc), and moreover some of its compounds are metals again with very high Tc's. Accordingly, combinations of niobium with hydrogen, with its high dynamic energy scale, are also of considerable interest. This is reinforced further by the suggestion that close to its insulator-metal transition, hydrogen may be induced to enter the metallic state somewhat prematurely by the addition of a relatively small concentration of a suitable transition metal. Here, the methods used correctly reproduce some ground-state structures of niobium hydrides at even higher concentrations of niobium. Interestingly, the particular stoichiometries represented by NbH4 and NbH6 are stabilized at fairly low pressures when proton zero-point energies are included. While no paired H2 units are found in any of the hydrides we have studied up to 400 GPa, we do find complex and interesting networks of hydrogens around the niobiums in high-pressure NbH6. The Nb-Nb separations in NbHn are consistently larger than those found in Nb metal at the respective pressures. The structures found in the ground states of the high hydrides, many of them metallic, suggest that the coordination number of hydrogens around each niobium atom grows approximately as 4n in NbHn (n = 1-4), and is as high as 20 in NbH6. NbH4 is found to be a plausible candidate to become a superconductor at high pressure, with an estimated Tc ˜ 38 K at 300 GPa.

  15. Ground-based SMART-COMMIT Measurements for Studying Aerosol and Cloud Properties

    Science.gov (United States)

    Tsay, Si-Chee

    2008-01-01

    From radiometric principles, it is expected that the retrieved properties of extensive aerosols and clouds from reflected/emitted measurements by satellite (and/or aircraft) should be consistent with those retrieved from transmitted/emitted radiance observed at the surface. Although space-borne remote sensing observations cover large spatial domain, they are often plagued by contamination of surface signatures. Thus, ground-based in-situ and remote-sensing measurements, where signals come directly from atmospheric constituents, the sun, and/or the Earth-atmosphere interactions, provide additional information content for comparisons that confirm quantitatively the usefulness of the integrated surface, aircraft, and satellite data sets. The development and deployment of SMARTCOMMIT (Surface-sensing Measurements for Atmospheric Radiative Transfer - Chemical, Optical & Microphysical Measurements of In-situ Troposphere) mobile facilities are aimed for the optimal utilization of collocated ground-based observations as constraints to yield higher fidelity satellite retrievals and to determine any sampling bias due to target conditions. To quantify the energetics of the surface-atmosphere system and the atmospheric processes, SMART-COMMIT instruments fall into three categories: flux radiometer, radiance sensor and in-situ probe. In this paper, we will demonstrate the capability of SMART-COMMIT in recent field campaigns (e.g., CRYSTAL-FACE, UAE 2, BASEASIA, NAMMA) that were designed and executed to study the compelling variability in temporal scale of both anthropogenic and natural aerosols (e.g., biomass-burning smoke, airborne dust) and cirrus clouds. We envision robust approaches in which well-collocated ground-based measurements and space-borne observations will greatly advance our knowledge of extensive aerosols and clouds.

  16. An Analysis of Changeability Grounds in Iranian Public Organizations: A Case Study in the Cities of Lamerd and Mohr

    National Research Council Canada - National Science Library

    Ali Naghi Amiri; Rasool Rasaeefard; Bahram Dastan

    2011-01-01

    .... To devise a proper model, we initially study the theoretical literature of change management and the resistance against change to determine the dimensions of changeability grounds (the first stage...

  17. Women's self-management of chronic illnesses in the context of caregiving: a grounded theory study.

    Science.gov (United States)

    Martinez-Marcos, Mercedes; De la Cuesta-Benjumea, Carmen

    2015-06-01

    Uncover how women self-manage their own chronic illness while taking care of a dependent relative. International policies place special emphasis in promoting interventions addressed to control, prevent and care for people with chronic health conditions. Self-management is a crucial part of this care. Caregivers are more prone to have chronic illness than non-caregivers. They are confronted with dilemmas about taking care of themselves while taking care of their dependent relative and the rest of their families. Caregivers articulate strategies to enable them to focus their energy on caring. Qualitative study using constructivist grounded theory. Thirty-nine women caregivers with a chronic illness participated in the study. Twenty-three semi-structured interviews and two focus groups were carried out between April 2010-December 2011. Data were analysed using grounded theory procedures. Self-management helps women caregivers with a chronic illness to balance the demands of their own illness and those of the dependent relative. They self-manage their illness by self-regulating the treatment, by regulating their strength and by controlling their emotions. Women caregivers integrate effectively and creatively the management of their chronic illnesses within the complexities of family care. This renders their health needs invisible and reaffirms them as capable caregivers. Identifying self-management strategies of women caregivers allow health professionals to acknowledge and reinforce effective self-care measures and to deter those that are ineffective and lessen their quality of life. © 2014 John Wiley & Sons Ltd.

  18. [Deep-sea research ground for the study of living matter properties in extreme conditions].

    Science.gov (United States)

    Polikarpov, G G

    2011-01-01

    The Black Sea hollow bottom is a promising research ground in the field of deep-sea radiochemoecology and exobiology. It has turned out to be at the intersection of the earth and cosmic scientific interests such as deep-sea marine radiochemoecology from the perspective of the study of extreme biogeocenological properties of the Earth biosphere and exobiology from the standpoint of the study of life phenomena (living matter) outside the Earth biosphere, i.e. on other planets and during hypothetical transfer of spores in the outer space. The potential of this ground is substantiated with the data published by the author and co-workers on accumulation of 90Sr, 137Cs and Pu isotopes with silts of bathyal pelo-contour, on the quality of deep-sea hydrogen sulphide waters (after their contact with air) for vital functions of planktonic and benthic aerobes, as well as the species composition of marine, freshwater and terrestrial plants grown from the spores collected from the bottom sediments of the Black Sea bathyal. Discussion was based on V.I. Vernadsky's ideas about the living matter and biosphere, which allowed conclusions about the biospheric and outer space role of the described phenomena.

  19. Ground state study of the thin ferromagnetic nano-islands for artificial spin ice arrays

    Energy Technology Data Exchange (ETDEWEB)

    Vieira Júnior, D. S., E-mail: damiao.vieira@ifsudestemg.edu.br [Departamento Acadêmico de Matemática, Física e Estatística, Instituto Federal de Educação, Ciência e Tecnologia do Sudeste de Minas Gerais - Câmpus Rio Pomba, Rio Pomba, Minas Gerais 36180-000 (Brazil); Departamento de Física, Laboratório de Simulação Computacional, Universidade Federal de Juiz de Fora, Juiz de Fora, Minas Gerais 36036-330 (Brazil); Leonel, S. A., E-mail: sidiney@fisica.ufjf.br; Dias, R. A., E-mail: radias@fisica.ufjf.br; Toscano, D., E-mail: danilotoscano@fisica.ufjf.br; Coura, P. Z., E-mail: pablo@fisica.ufjf.br; Sato, F., E-mail: sjfsato@fisica.ufjf.br [Departamento de Física, Laboratório de Simulação Computacional, Universidade Federal de Juiz de Fora, Juiz de Fora, Minas Gerais 36036-330 (Brazil)

    2014-09-07

    In this work, we used numerical simulations to study the magnetic ground state of the thin elongated (elliptical) ferromagnetic nano-islands made of Permalloy. In these systems, the effects of demagnetization of dipolar source generate a strong magnetic anisotropy due to particle shape, defining two fundamental magnetic ground state configurations—vortex or type C. To describe the system, we considered a model Hamiltonian in which the magnetic moments interact through exchange and dipolar potentials. We studied the competition between the vortex states and aligned states—type C—as a function of the shape of each elliptical nano-islands and constructed a phase diagram vortex—type C state. Our results show that it is possible to obtain the elongated nano-islands in the C-state with aspect ratios less than 2, which is interesting from the technological point of view because it will be possible to use smaller islands in spin ice arrays. Generally, the experimental spin ice arrangements are made with quite elongated particles with aspect ratio approximately 3 to ensure the C-state.

  20. Study of role of meniscus and viscous forces during liquid-mediated contacts separation

    Science.gov (United States)

    Dhital, Prabin

    Menisci may form between two solid surfaces with the presence of an ultra-thin liquid film. When the separation operation is needed, meniscus and viscous forces contribute to an adhesion leading stiction, high friction, possibly high wear and potential failure of the contact systems, for instance microdevices, magnetic head disks and diesel fuel injectors. The situation may become more pronounced when the contacting surfaces are ultra-smooth and the normal load is small. Various design parameters, such as contact angle, initial separation height, surface tension and liquid viscosity, have been investigated during liquid-mediated contact separation. However, how the involved forces will change roles for various liquid is of interest and is necessary to be studied. In this study, meniscus and viscous forces due to water and liquid lubricants during separation of two flat surfaces are studied. Previously established mathematical model for meniscus and viscous forces during flat on flat contact separation is simulated. The effect of meniscus and viscous force on critical meniscus area at which those forces change role is studied with different liquid properties for flat on flat contact surfaces. The roles of the involved forces at various meniscus areas are analyzed. Experiments are done in concerns to studying the effect of surface roughness on contact angle. The impact of liquid properties, initial separation heights and contact angle on critical meniscus area for different liquid properties are analyzed. The study provides a fundamental understanding of the forces of the separation process and its value for the design of interfaces. The effect of surface roughness and liquid properties on contact angle are studied.

  1. Nursing students' time management, reducing stress and gaining satisfaction: a grounded theory study.

    Science.gov (United States)

    Mirzaei, Tayebeh; Oskouie, Fatemeh; Rafii, Forough

    2012-03-01

    In the course of their studies, nursing students must learn many skills and acquire the knowledge required for their future profession. This study investigates how Iranian nursing students manage their time according to the circumstances and obstacles of their academic field. Research was conducted using the grounded theory method. Twenty-one nursing students were purposefully chosen as participants. Data was collected through semi-structured interviews and analyzed using the method suggested by Corbin and Strauss. One of the three processes that the nursing students used was "unidirectional time management." This pattern consists of accepting the nursing field, overcoming uncertainty, assessing conditions, feeling stress, and trying to reduce stress and create satisfaction. It was found that students allotted most of their time to academic tasks in an attempt to overcome their stress. The findings of this study indicate the need for these students to have time for the extra-curricular activities and responsibilities that are appropriate to their age.

  2. Study on Some Physico-Chemical Characteristics of Ground Water of District Rampur - A Statistical Approach

    Directory of Open Access Journals (Sweden)

    Susheel Kumar Sindhu

    2007-01-01

    Full Text Available A systematic study has been carried out to explore the water quality index of ground water of various tehsils of Rampur district. Twenty five water samples from tube wells, open wells and hand pumps at various locations were collected and analyzed for pH, nitrate, turbidity, total dissolve solid, chlorides, total hardness, alkalinity and fluoride. In this study overall water quality of Rampur district is very poor and unsuitable for drinking purpose. Water quality of Bilaspur, Shahabad and Rampur city shows that water may not be used for drinking as well as domestic purpose. Present study recommends that the top priority should be given to water quality monitoring and indigenous technologies should be adopted to make water fit for drinking after treatment such as defluoridation, desalination.

  3. Integrated ground-based and remotely sensed data to support global studies of environmental change

    Energy Technology Data Exchange (ETDEWEB)

    Olson, R.J.; Turner, R.S.; Garten, C.T.

    1994-09-15

    Data centers routinely archive and distribute large databases of high quality and with rigorous documentation but, to meet the needs of global studies effectively and efficiently, data centers must go beyond these traditional roles. Global studies of environmental change require integrated databases of multiple data types that are accurately coordinated in terms of spatial, temporal and thematic properties. Such datasets must be designed and developed jointly by scientific researchers, computer specialists, and policy analysts. The presentation focuses on our approach for organizing data from ground-based research programs so that the data can be linked with remotely sensed data and other map data into integrated databases with spatial, temporal, and thematic characteristics relevant to global studies. The development of an integrated database for Net Primary Productivity is described to illustrate the process.

  4. Violence against Teachers: Case Studies from the APA Task Force

    Science.gov (United States)

    Reddy, Linda A.; Espelage, Dorothy; McMahon, Susan D.; Anderman, Eric M.; Lane, Kathleen Lynne; Brown, Veda Evanell; Reynolds, Cecil R.; Jones, Abraham; Kanrich, Jaclyn

    2013-01-01

    Violence directed toward teachers has been understudied despite significant media and empirical investigation on school violence, such as student-to-student victimization and bullying. To date, there are relatively few published studies scattered across many countries. To address this void, the American Psychological Association, in collaboration…

  5. Boundary of the ground-water flow model by IT Corporation (1996), for the Death Valley regional ground-water flow system study, Nevada and California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital data set defines the boundary of the steady-state ground-water flow model built by IT Corporation (1996). The regional, 20-layer ground-water flow...

  6. Risk and Resilience in Deployed Air Force Medical Personnel Study

    Science.gov (United States)

    2011-09-15

    Kronenberg, Many, & Ososfsky, 2008, p. 211). The importance of taking an active role is high- lighted by Hobfoll, Canetti -Nisim, Galea, Johnson, and... Canetti , D., Johnson, R., Palmieri, P., & Galea, S. (2010). Exploring the association between posttraumatic growth and PTSD: National Study of Jews and...797–816. doi:10.1037/0022-006X.74.5.797 Hobfoll, S., Hall, B., Canetti -Nisim, D., Galea, S., Johnson, R., & Palmieri, P. (2007). Refining our

  7. Ecological study requirements for Vandenberg Air Force Base, California

    Energy Technology Data Exchange (ETDEWEB)

    Wooten, R.C. Jr. (Air Force Weapons Lab., Albuquerque, NM); Meyer, G.F.; Sigler, J.W.; Scott, C.L.

    1975-01-23

    The impact of the Space Transportation System on the ecology of Vandenberg and the need and direction of future land management are determined. Vandenberg has a variety of vegetative communities which support various species of animal and bird life. The coastal areas may support a rich abundance of marine life. Recommendations include a systematic approach and multidiscipline study to determine the significance and associativity of the various forms of biota.

  8. The Lavelle Affair: An Air Force Case Study in Ethics

    Science.gov (United States)

    2016-06-01

    November 1971 and March 1972 under a liberal interpretation of the Rules of Engagement (ROE) and subsequently directed reporting procedures “to...present may continue to remember General John Lavelle as a wartime commander who defied rules of engagement and directed his subordinates to falsify...studying the physical sciences and playing basketball for two years on a partial scholarship. Lavelle maintained full-time employment at the local

  9. Studies of FAUNA at Eglin Air Force Base

    Science.gov (United States)

    2006-07-01

    competition between them. Population Studies of Amphibians Eglin is home to a diverse suite of amphibians and reptiles including the federally...birds that might otherwise have been available for translocation (i.e., juveniles of both sexes , helper males and floater females) away from their...required them. By allocating greater effort to cavity management in 2005 we were able to “catch up” with losses to hurricanes the previous year, as

  10. A Comparative Study of Ground and Underground Vibrations Induced by Bench Blasting

    Directory of Open Access Journals (Sweden)

    Xiuzhi Shi

    2016-01-01

    Full Text Available Ground vibrations originating from bench blasting may cause damage to slopes, structures, and underground workings in close proximity to an operating open-pit mine. It is important to monitor and predict ground vibration levels induced by blasting and to take measures to reduce their hazardous effects. The aims of this paper are to determine the weaker protection objects by comparatively studying bench blasting induced vibrations obtained at surface and in an underground tunnel in an open-pit mine and thus to seek vibration control methods to protect engineering objects at the site. Vibrations arising from measurement devices at surface and in an underground tunnel at the Zijinshan Open-Pit Mine were obtained. Comparative analysis of the peak particle velocities shows that, in the greatest majority of cases, surface values are higher than underground values for the same vibration distance. The transmission laws of surface and underground vibrations were established depending on the type of rock mass, the explosive charge, and the distance. Compared with the Chinese Safety Regulations for Blasting (GB6722-2014, the bench blasting induced vibrations would not currently cause damage to the underground tunnel. According to the maximum allowable peak particle velocities for different objects, the permitted maximum charges per delay are obtained to reduce damage to these objects at different distances.

  11. Demonstration/Validation of the Snap Sampler Passive Ground Water Sampling Device for Sampling Inorganic Analytes at the Former Pease Air Force Base

    Science.gov (United States)

    2009-07-01

    it starts to undergo biodegradation . Also, because diffusion samplers typically require at least several days for equilibration to occur, they... PAHs ), and metals have been found in soils on the base. The ground wa- ter has been found to be contaminated with volatile organic compounds ERDC...CRREL TR-09-12 14 (VOCs) including trichloroethylene (TCE) and tetrachloroethylene (PCE). PAHs , pesticides, and heavy metals have been found in the

  12. Investigating the combined impact of plasticizer and shear force on the efficiency of low temperature reclaiming of ground tire rubber (GTR)

    OpenAIRE

    Formela, Krzysztof; Klein, Marek; Colom Fajula, Xavier; Reza Saeb, Mohammad

    2016-01-01

    In the present work, ground tire rubber (GTR) was mechano-chemically reclaimed at ambient temperature using two-roll mills. Road bitumen and styrene-butadiene-styrene (SBS)-modified bitumen at variable content (in range: 2.5-20 phr) were applied as reactive plasticizers to enhance reclaiming of GTR. For better understanding the plasticizing effect of bitumen on the quality of obtained reclaimed rubber, mechano-chemically reclaimed GTR has been compared with GTR after thermo-mechanical reclaim...

  13. Experimental study of frost heaving force based on transient shock response using piezoceramic sensors

    Science.gov (United States)

    Wang, Ruolin; Peng, Tongxiao; Wang, Ming L.

    2016-04-01

    In seasonally frozen soil regions, the frost heaving problem made it difficult to monitor or evaluate the pile safety for long term. So far, no mature tool can be utilized to monitor the frost heaving force, which was unevenly distributed along the pile. In this paper, a piezoceramic sensing based transient excitation response approach was proposed to monitor the frost heaving force in real time. Freeze-thaw cycles can result in great changes of soil engineering properties, including the frost heaving force. So, the freeze-thaw cycle was repeated fourth to study its effect. In the experiment, transient horizontal shock on the top of the pile will be detected by the 6 PZT sensors glued on the pile. The signal data received by the 6 PZT sensors can be used to illustrate the frost heaving force distribution along the pile. Moisture content effect is also one of the important reasons that cause the variation of soil mechanical properties. So three different moisture content (6%, 12%, 18%) testing soil were used in this experiment to detect the variance of the frost heaving force. An energy indicator was developed to quantitatively evaluate the frost heaving force applied on the pile. The experimental results showed that the proposed method was effective in monitoring the uneven distribution of frost heaving force along the pile.

  14. A test on reactive force fields for the study of silica dimerization reactions

    Energy Technology Data Exchange (ETDEWEB)

    Moqadam, Mahmoud; Riccardi, Enrico; Trinh, Thuat T.; Åstrand, Per-Olof; Erp, Titus S. van, E-mail: titus.van.erp@ntnu.no [Department of Chemistry, Norwegian University of Science and Technology (NTNU), Høgskoleringen 5, Realfagbygget D3-117, 7491 Trondheim (Norway)

    2015-11-14

    We studied silica dimerization reactions in the gas and aqueous phase by density functional theory (DFT) and reactive force fields based on two parameterizations of ReaxFF. For each method (both ReaxFF force fields and DFT), we performed constrained geometry optimizations, which were subsequently evaluated in single point energy calculations using the other two methods. Standard fitting procedures typically compare the force field energies and geometries with those from quantum mechanical data after a geometry optimization. The initial configurations for the force field optimization are usually the minimum energy structures of the ab initio database. Hence, the ab initio method dictates which structures are being examined and force field parameters are being adjusted in order to minimize the differences with the ab initio data. As a result, this approach will not exclude the possibility that the force field predicts stable geometries or low transition states which are realistically very high in energy and, therefore, never considered by the ab initio method. Our analysis reveals the existence of such unphysical geometries even at unreactive conditions where the distance between the reactants is large. To test the effect of these discrepancies, we launched molecular dynamics simulations using DFT and ReaxFF and observed spurious reactions for both ReaxFF force fields. Our results suggest that the standard procedures for parameter fitting need to be improved by a mutual comparative method.

  15. Effect of intrusive and retraction forces in labial and lingual orthodontics: A finite element study

    Directory of Open Access Journals (Sweden)

    Rohan Mascarenhas

    2014-01-01

    Full Text Available Objectives: Lingual orthodontics differs in biomechanics as compared to labial system and has biomechanical advantages. Although theoretical approaches have explained the differences between labial and lingual orthodontics, the finite element method (FEM may be better suited to analyze these differences. This study analyzes the effect of vertical and horizontal forces together on the tooth using FEM. Materials and Methods: An extracted right maxillary central incisor was radiographed and was used to create a solid model using ANSYS. The geometric model was converted into a finite element model with the help of ANSYS software. The model consists of 27,000 elements and 30,000 nodes. Two force vectors (vertical and horizontal were applied labially and lingually at 3 different heights- 4 mm, 5 mm and 6 mm from the incisal edge. Results: In the labial system, the net force vector passes through the center of resistance (CR and brings about intrusion. The net force vector in lingual orthodontics does not pass through the center of resistance and produces lingual tipping of the incisors. Conclusion: Intrusion and retraction forces bring about tipping of incisors in lingual orthodontics. The same amount of intrusion and retraction forces brings about intrusion of incisors in labial orthodontics. Therefore, direction and amount of forces should be carefully and judiciously applied after taking into consideration the resultant biomechanical differences.

  16. Mid-latitude wind forced ocean circulation studies

    Science.gov (United States)

    Harrison, D. E.

    1981-01-01

    A simple barotropic vorticity equation model was developed to study some of the various modeling factors that affect the characteristics of strong western boundary currents like the Gulf Stream and Kuroshio. Successful prediction of sea surface temperature, both in the climatological mean and over periods as short as 1 month requires that the heating tendency, due to horizontal advection of heat by these currents, be accurately modeled. Conventional, coarse resolution ocean models do not satisfactorily reproduce the dominant features of these currents. It is concluded that it is important to understand why they do not and what must be done to do so in the future.

  17. A Medicosocial Study Of Paraplegics In Armed Forces

    Directory of Open Access Journals (Sweden)

    Dutta Col P.K

    1986-01-01

    Full Text Available A cross sectional study of 81 paraplegics was carried out to determine various medical and psychosocial aspects of the disability. Majority of the cases were results of preventable external injuries, which mostly affected the young productive age group. A large number of cases had permanent impairment of mobility, bowel, bladder and sexual functions. Psychological reactions of anxiety and denial were most frequently encountered in initial stages, but gradually declined in successive stages of rehabilitation. Individuals with independent vocations were psychologically and socially well adjusted.

  18. Cellulose fibril aggregation studies of eucalyptus dissolving pulps using atomic force microscopy

    CSIR Research Space (South Africa)

    Chunilall, Viren

    2006-11-01

    Full Text Available STUDIES OF Eucalyptus DISSOLVING PULPS USING ATOMIC FORCE MICROSCOPY V. Chunilall1, J.Wesley-Smith2, T. Bush1 1CSIR, Forestry and Forest Product Research Centre, P.O. Box 17001, Congella, 4013, South Africa. 2Electron Microscope Unit, University of Kwa... pulp using atomic force microscopy (AFM) have reported increased cellulose fibril aggregation during processing, and a concomitant decrease in surface area available for chemical reaction1,2. These findings were subsequently confirmed...

  19. A Case Study On Human Capital Mismanagement In The United States Air Force

    Science.gov (United States)

    2016-05-08

    AIR COMMAND AND STAFF COLLEGE AIR UNIVERSITY A Case Study on Human Capital Mismanagement in the United States Air Force By John P...Force does not effectively manage its human capital to develop and retain a technically literate acquisitions workforce. A detailed look at the...Several solutions are suggested to improve the human capital management and increase the quality and relevancy of the acquisitions community at

  20. Atomic force microscopy study of cellulose surface interaction controlled by cellulose binding domains

    OpenAIRE

    Nigmatullin, R.; Lovitt, R.; Wright, C; Linder, M.; Nakari-Setälä, T; Gama, F. M.

    2004-01-01

    Colloidal probe microscopy has been used to study the interaction between model cellulose surfaces and the role of cellulose binding domain (CBD), peptides specifically binding to cellulose, in interfacial interaction of cellulose surfaces modified with CBDs. The interaction between pure cellulose surfaces in aqueous electrolyte solution is dominated by double layer repulsive forces with the range and magnitude of the net force dependent on electrolyte concentration. AFM imaging reve...

  1. Developing a Taxonomy of Dark Triad Triggers at Work – A Grounded Theory Study Protocol

    Science.gov (United States)

    Nübold, Annika; Bader, Josef; Bozin, Nera; Depala, Romil; Eidast, Helena; Johannessen, Elisabeth A.; Prinz, Gerhard

    2017-01-01

    In past years, research and corporate scandals have evidenced the destructive effects of the dark triad at work, consisting of narcissism (extreme self-centeredness), psychopathy (lack of empathy and remorse) and Machiavellianism (a sense of duplicity and manipulativeness). The dark triad dimensions have typically been conceptualized as stable personality traits, ignoring the accumulating evidence that momentary personality expressions – personality states – may change due to the characteristics of the situation. The present research protocol describes a qualitative study that aims to identify triggers of dark triad states at work by following a grounded theory approach using semi-structured interviews. By building a comprehensive categorization of dark triad triggers at work scholars may study these triggers in a parsimonious and structured way and organizations may derive more effective interventions to buffer or prevent the detrimental effects of dark personality at work. PMID:28326048

  2. Study of temperature rises and forces on drilling bone

    Science.gov (United States)

    Srikanth Venkataraman, Ananya

    Many different approaches have been used to prepare, store and test bone samples in order to determine its physical properties. The need to establish a standard method of specimen preparation and storage prior to experimental testing, contributed greatly to the primary part of this study. When mechanized cutting tools such as saws and drills are used, heat is produced and this raises the temperature of both the tool and the material being cut. In orthopedic and dental practices, high-speed tools are often applied to bones and teeth, and heat from these operations may result in thermal necrosis [1]. Since this can have a negative impact on the outcome of an orthopedic procedure, temperatures must be kept below the threshold that results in bone necrosis. The initial set of experiments was performed to determine the conditions under which the mechanical properties of the bone changed so as to establish the most suitable testing conditions. The hardness variation of the bone samples, under different annealing treatment conditions was used as the indicating parameter for evaluation of the change in the mechanical properties. Establishing the most appropriate section of the metacarpal sample for testing, by studying the anisotropy of the bone was another determining parameter. The second step was to examine the effects of conventional drilling as well as modulation assisted drilling on the temperature rise generated in the bone during these machining processes. In addition to this, a set of experiments were performed to ascertain how lubrication affected the temperature rise during drilling. The dynamic portions of the torque and thrust traces as well as the specific energies were compared for the different drilling conditions. Modulation showed no significant effect on the mean torque, thrust, specific energies of cutting, or temperature rise. Lubrication (flooding and misting) in both the modulation and no modulation cases drastically reduced the temperature rise

  3. Nutritional status assessment in semiclosed environments: ground-based and space flight studies in humans

    Science.gov (United States)

    Smith, S. M.; Davis-Street, J. E.; Rice, B. L.; Nillen, J. L.; Gillman, P. L.; Block, G.

    2001-01-01

    Adequate nutrition is critical during long-term spaceflight, as is the ability to easily monitor dietary intake. A comprehensive nutritional status assessment profile was designed for use before, during and after flight. It included assessment of both dietary intake and biochemical markers of nutritional status. A spaceflight food-frequency questionnaire (FFQ) was developed to evaluate intake of key nutrients during spaceflight. The nutritional status assessment protocol was evaluated during two ground-based closed-chamber studies (60 and 91 d; n = 4/study), and was implemented for two astronauts during 4-mo stays on the Mir space station. Ground-based studies indicated that the FFQ, administered daily or weekly, adequately estimated intake of key nutrients. Chamber subjects maintained prechamber energy intake and body weight. Astronauts tended to eat 40--50% of WHO-predicted energy requirements, and lost >10% of preflight body mass. Serum ferritin levels were lower after the chamber stays, despite adequate iron intake. Red blood cell folate concentrations were increased after the chamber studies. Vitamin D stores were decreased by > 40% on chamber egress and after spaceflight. Mir crew members had decreased levels of most nutritional indices, but these are difficult to interpret given the insufficient energy intake and loss of body mass. Spaceflight food systems can provide adequate intake of macronutrients, although, as expected, micronutrient intake is a concern for any closed or semiclosed food system. These data demonstrate the utility and importance of nutritional status assessment during spaceflight and of the FFQ during extended-duration spaceflight.

  4. Study of the pairing force in nuclei; Etude de la force d'appariement dans les noyaux

    Energy Technology Data Exchange (ETDEWEB)

    Duguet, T

    1999-01-01

    This work is dedicated to the study of the pairing potential for the nuclei in the stability valley and for the super-deformed isotope groups. The purpose is to propose a pairing force that could be considered as a reference in order to explore the exotic nuclei on safer basis. The domain on which the potential parameters have been studied is defined by: ecut = 5 {+-} 2 MeV, dcut = 0.5 MeV, V{sub 0} = 1000 {+-} 200 MeV for 1 cut, V{sub 0} = 1200 {+-} 200 MeV for 2 cuts. As for the choice of nuclei 3 crosses in the (N,Z) plane have been defined, each centered around a doubly magic isotope: N=Z=28, N=Z=50 and N=Z=82. The results are presented for the nuclei around Ni{sup 56}. It is shown that the best choice for potential parameters is V{sub 0} = 1000 MeV and ecut = 4 MeV, but the pairing effect remains underestimated for the nuclei between N=28 and N=32. For the nuclei N {<=} 26 or N {>=} 38 the disagreement is more important and it requires more than an optimization of the pairing effect for being corrected, the causes of the discrepancy seem to be an insufficient mean field and a lack of accuracy in the Hartree-Fock part. (A.C.)

  5. Sifting, sorting and saturating data in a grounded theory study of information use by practice nurses: a worked example.

    Science.gov (United States)

    Hoare, Karen J; Mills, Jane; Francis, Karen

    2012-12-01

    The terminology used to analyse data in a grounded theory study can be confusing. Different grounded theorists use a variety of terms which all have similar meanings. In the following study, we use terms adopted by Charmaz including: initial, focused and axial coding. Initial codes are used to analyse data with an emphasis on identifying gerunds, a verb acting as a noun. If initial codes are relevant to the developing theory, they are grouped with similar codes into categories. Categories become saturated when there are no new codes identified in the data. Axial codes are used to link categories together into a grounded theory process. Memo writing accompanies this data sifting and sorting. The following article explains how one initial code became a category providing a worked example of the grounded theory method of constant comparative analysis. The interplay between coding and categorization is facilitated by the constant comparative method.

  6. Molecular dynamics simulation study of friction force and torque on a rough spherical particle.

    Science.gov (United States)

    Kohale, Swapnil C; Khare, Rajesh

    2010-06-21

    Recent developments in techniques of micro- and nanofluidics have led to an increased interest in nanoscale hydrodynamics in confined geometries. In our previous study [S. C. Kohale and R. Khare, J. Chem. Phys. 129, 164706 (2008)], we analyzed the friction force experienced by a smooth spherical particle that is translating in a fluid confined between parallel plates. The magnitude of three effects--velocity slip at particle surface, the presence of confining surfaces, and the cooperative hydrodynamic interactions between periodic images of the moving particle--that determine the friction force was quantified in that work using molecular dynamics simulations. In this work, we have studied the motion of a rough spherical particle in a confined geometry. Specifically, the friction force experienced by a translating particle and the torque experienced by a rotating particle are studied using molecular dynamics simulations. Our results demonstrate that the surface roughness of the particle significantly reduces the slip at the particle surface, thus leading to higher values of the friction force and hence a better agreement with the continuum predictions. The particle size dependence of the friction force and the torque values is shown to be consistent with the expectations from the continuum theory. As was observed for the smooth sphere, the cooperative hydrodynamic interactions between the images of the sphere have a significant effect on the value of the friction force experienced by the translating sphere. On the other hand, the torque experienced by a spherical particle that is rotating at the channel center is insensitive to this effect.

  7. A study on the characteristics of strong ground motions in southern Korea

    Energy Technology Data Exchange (ETDEWEB)

    Bang, Chang Eob; Lee, Kie Hwa; Kang, Tae Seob [Seoul National Univ., Seoul (Korea, Republic of)

    2001-12-15

    Ground motion characteristics in southern Korea are analyzed such as the variations of ground motion durations depending on the hypocentral distance, the earthquake magnitude and the frequency contents of the motion, and the predominant frequency of the maximum ground motion, the ratio of the horizontal to the vertical component amplitudes, the frequency dependence of the Coda Q values, the local distribution of Lg Q values using recorded data sets.

  8. Desarrollo cultural en las organizaciones. Un modelo de estudio basado en la Grounded Theory Cultural development in organizations. A model study based on the Grounded Theory

    Directory of Open Access Journals (Sweden)

    Manuel SÁNCHEZ-SANVICENTE

    2012-08-01

    Full Text Available La cultura organizacional se configura a partir de la interrelación de los procesos de apropiación de la filosofía, la pertenencia, la adaptación, la satisfacción y el liderazgo compartidos por un grupo. Este conjunto de categorías puede ser reconocido mediante el uso de una matriz que incluye en su estructura subcategorías o conceptos y un conjunto de propiedades observables en el público interno. El presente artículo tiene por objetivo describir un modelo de estudio construido a partir de la Grounded Theory o Teoría Fundamentada que nos permita comprender el desarrollo cultural de las organizaciones. El estudio de caso se realizó en una compañía líder en Europa del sector de la distribución.AbstractThe organizational culture is set from the interplay of the processes of appropriation of philosophy, membership, adaptation, satisfaction and leadership shared by a group. This set of categories can be recognized by using a matrix that includes in its structure or sub-concepts and a set of observable properties in the workforce. This article aims to describe a study model built from the Grounded Theory that allows us to understand the cultural development of organizations. The case study was conducted in a European leader in the distribution sector.

  9. The Rediscovery and Resurrection of Bunk Johnson – a Grounded Theory Approach: A case study in jazz historiography

    Directory of Open Access Journals (Sweden)

    Richard Ekins, Ph.D., FRSA

    2011-12-01

    Full Text Available This paper was written in the beginning phase of my transitioning from grounded theory sociologist (Ekins, 19971 to grounded theory musicologist (Ekins, 20102. In particular, it provides preliminary data for a grounded theory of ‘managing authenticity’, the core category/basic social process (Glaser, 1978 that has emerged from my ongoing grounded theory work in jazz historiography. It was written whilst I was ‘credentialising’ (Glaser, 2010 my transition to popular music studies and popular musicology. In consequence, it incorporates many aspects that are inimical to classic grounded theory. As with so much of Straussian and so-called constructivist grounded theory (Bryant and Charmaz, 2007, it roots itself in G.H. Mead and a social constructivist symbolic interactionism – inter alia, a legitimising (authenticating strategy. Moreover, as is typical of this mode of conceptualising, the paper fills the void of inadequate classic grounded theorising with less conceptual theorising and more conceptual description. Nevertheless, the article does introduce a number of categories that ‘fit and work’, and have ‘conceptual grab’ (Glaser, 1978; Glaser, 1992. In particular, in terms of my own continuing credentialising as a classic grounded theorist, it sets forth important categories to be integrated into my ongoing work on managing authenticity in New Orleans revivalist jazz, namely, ‘trailblazing’, ‘mythologizing’, ‘debunking’, and ‘marginalising’, in the context of the ‘rediscovering’ and ‘resurrecting’ of a jazz pioneer. More specifically, the paper is offered to classic grounded theorists as a contribution to preliminary generic social process analysis in the substantive area of jazz historiography.

  10. Large atmospheric shortwave radiative forcing by Mediterranean aerosols derived from simultaneous ground-based and spaceborne observations and dependence on the aerosol type and single scattering albedo

    Science.gov (United States)

    di Biagio, Claudia; di Sarra, Alcide; Meloni, Daniela

    2010-05-01

    Aerosol optical properties and shortwave irradiance measurements at the island of Lampedusa (central Mediterranean) during 2004-2007 are combined with Clouds and the Earth's Radiant Energy System observations of the outgoing shortwave flux at the top of the atmosphere (TOA). The measurements are used to estimate the surface (FES), the top of the atmosphere (FETOA), and the atmospheric (FEATM) shortwave aerosol forcing efficiencies for solar zenith angle (θ) between 15° and 55° for desert dust (DD), urban/industrial-biomass burning aerosols (UI-BB), and mixed aerosols (MA). The forcing efficiency at the different atmospheric levels is derived by applying the direct method, that is, as the derivative of the shortwave net flux versus the aerosol optical depth at fixed θ. The diurnal average forcing efficiency at the surface/TOA at the equinox is (-68.9 ± 4.0)/(-45.5 ± 5.4) W m-2 for DD, (-59.0 ± 4.3)/(-19.2 ± 3.3) W m-2 for UI-BB, and (-94.9 ± 5.1)/(-36.2 ± 1.7) W m-2 for MA. The diurnal average atmospheric radiative forcing at the equinox is (+7.3 ± 2.5) W m-2 for DD, (+8.4 ± 1.9) W m-2 for UI-BB, and (+8.2 ± 1.9) W m-2 for MA, suggesting that the mean atmospheric forcing is almost independent of the aerosol type. The largest values of the atmospheric forcing may reach +35 W m-2 for DD, +23 W m-2 for UI-BB, and +34 W m-2 for MA. FETOA is calculated for MA and 25° ≤ θ ≤ 35° for three classes of single scattering albedo (0.7 ≤ ω < 0.8, 0.8 ≤ ω < 0.9, and 0.9 ≤ ω ≤ 1) at 415.6 and 868.7 nm: FETOA increases, in absolute value, for increasing ω. A 0.1 increment in ω determines an increase in FETOA by 10-20 W m-2.

  11. Ground-Water Recharge in Humid Areas of the United States--A Summary of Ground-Water Resources Program Studies, 2003-2006

    Science.gov (United States)

    Delin, Geoffrey N.; Risser, Dennis W.

    2007-01-01

    Increased demands on water resources by a growing population and recent droughts have raised awareness about the adequacy of ground-water resources in humid areas of the United States. The spatial and temporal variability of ground-water recharge are key factors that need to be quantified to determine the sustainability of ground-water resources. Ground-water recharge is defined herein as the entry into the saturated zone of water made available at the water-table surface, together with the associated flow away from the water table within the saturated zone (Freeze and Cherry, 1979). In response to the need for better estimates of ground-water recharge, the Ground-Water Resources Program (GWRP) of the U.S. Geological Survey (USGS) began an initiative in 2003 to estimate ground-water recharge rates in the relatively humid areas of the United States.

  12. Model Study of Three-Body Forces in the Three-Body Bound State

    CERN Document Server

    Liu, H; Glöckle, W; Elster, Ch.

    2003-01-01

    The Faddeev equations for the three-body bound state with two- and three-body forces are solved directly as three-dimensional integral equation. The numerical feasibility and stability of the algorithm, which does not employ partial wave decomposition is demonstrated. The three-body binding energy and the full wave function are calculated with Malfliet-Tjon-type two-body potentials and scalar Fujita-Miyazawa type three-body forces. The influence of the strength and range of the three-body force on the wave function, single particle momentum distributions and the two-body correlation functions are studied in detail. The extreme case of pure three-body forces is investigated as well.

  13. STUDY OF INFLUENCE OF EFFLUENT ON GROUND WATER USING REMOTE SENSING, GIS AND MODELING TECHNIQUES

    Directory of Open Access Journals (Sweden)

    S. Pathak

    2012-07-01

    Full Text Available The area lies in arid zone of western Rajasthan having very scanty rains and very low ground water reserves. Some of the other problems that are faced by the area are disposal of industrial effluent posing threat to its sustainability of water resource. Textiles, dyeing and printing industries, various mechanical process and chemical/synthetic dyes are used and considerable wastewater discharged from these textile units contains about high amount of the dyes into the adjoining drainages. This has caused degradation of water quality in this water scarce semi-arid region of the country. Pali city is located South-West, 70 Kms from Jodhpur in western Rajasthan (India. There are four Common Effluent Treatment Plant (CETP treating wastewater to meet the pollutant level permissible to river discharge, a huge amount of effluent water of these factories directly meets the into the river Bandi – a tributary of river Luni. In order to monitor the impact of industrial effluents on the environment, identifying the extent of the degradation and evolving possible means of minimizing the impacts studies on quality of effluents, polluted river water and water of adjoining wells, the contamination migration of the pollutants from the river to ground water were studied. Remote sensing analysis has been carried out using Resourcesat −1 multispectral satellite data along with DEM derived from IRS P5 stereo pair. GIS database generated of various thematic layers viz. base layer – inventorying all waterbodies in the vicinity, transport network and village layer, drainage, geomorphology, structure, land use. Analysis of spatial distribution of the features and change detection in land use/cover carried out. GIS maps have been used to help factor in spatial location of source and hydro-geomorphological settings. DEM & elevation contour helped in delineation of watershed and identifying flow modelling boundaries. Litholog data analysis carried out for aquifer

  14. Study of Influence of Effluent on Ground Water Using Remote Sensing, GIS and Modeling Techniques

    Science.gov (United States)

    Pathak, S.; Bhadra, B. K.; Sharma, J. R.

    2012-07-01

    The area lies in arid zone of western Rajasthan having very scanty rains and very low ground water reserves. Some of the other problems that are faced by the area are disposal of industrial effluent posing threat to its sustainability of water resource. Textiles, dyeing and printing industries, various mechanical process and chemical/synthetic dyes are used and considerable wastewater discharged from these textile units contains about high amount of the dyes into the adjoining drainages. This has caused degradation of water quality in this water scarce semi-arid region of the country. Pali city is located South-West, 70 Kms from Jodhpur in western Rajasthan (India). There are four Common Effluent Treatment Plant (CETP) treating wastewater to meet the pollutant level permissible to river discharge, a huge amount of effluent water of these factories directly meets the into the river Bandi - a tributary of river Luni. In order to monitor the impact of industrial effluents on the environment, identifying the extent of the degradation and evolving possible means of minimizing the impacts studies on quality of effluents, polluted river water and water of adjoining wells, the contamination migration of the pollutants from the river to ground water were studied. Remote sensing analysis has been carried out using Resourcesat -1 multispectral satellite data along with DEM derived from IRS P5 stereo pair. GIS database generated of various thematic layers viz. base layer - inventorying all waterbodies in the vicinity, transport network and village layer, drainage, geomorphology, structure, land use. Analysis of spatial distribution of the features and change detection in land use/cover carried out. GIS maps have been used to help factor in spatial location of source and hydro-geomorphological settings. DEM & elevation contour helped in delineation of watershed and identifying flow modelling boundaries. Litholog data analysis carried out for aquifer boundaries using specialized

  15. A study of Iranian immigrants’ experiences of accessing Canadian health care services: a grounded theory

    Directory of Open Access Journals (Sweden)

    Dastjerdi Mahdieh

    2012-09-01

    Full Text Available Abstract Background Immigration is not a new phenomenon but, rather, has deep roots in human history. Documents from every era detail individuals who left their homelands and struggled to reestablish their lives in other countries. The aim of this study was to explore and understand the experience of Iranian immigrants who accessed Canadian health care services. Research with immigrants is useful for learning about strategies that newcomers develop to access health care services. Methods The research question guiding this study was, “What are the processes by which Iranian immigrants learn to access health care services in Canada?” To answer the question, a constructivist grounded theory approach was applied. Initially, unstructured interviews were conducted with 17 participants (11 women and six men who were adults (at least 18 years old and had immigrated to Canada within the past 15 years. Eight participants took part in a second interview, and four participants took part in a third interview. Results Using a constructivist grounded theory approach, “tackling the stumbling blocks of access” emerged as the core category. The basic social process (BSP, becoming self-sufficient, was a transitional process and had five stages: becoming a stranger; feeling helpless; navigating/seeking information; employing strategies; and becoming integrated and self-sufficient. We found that “tackling the stumbling blocks of access” was the main struggle throughout this journey. Some of the immigrants were able to overcome these challenges and became proficient in accessing health care services, but others were unable to make the necessary changes and thus stayed in earlier stages/phases of transition, and sometimes returned to their country of origin. Conclusion During the course of this journey a substantive grounded theory was developed that revealed the challenges and issues confronted by this particular group of immigrants. This process explains

  16. Building COPD care on shaky ground: a mixed methods study from Swedish primary care professional perspective.

    Science.gov (United States)

    Lundell, Sara; Tistad, Malin; Rehn, Börje; Wiklund, Maria; Holmner, Åsa; Wadell, Karin

    2017-07-10

    Chronic obstructive pulmonary disease (COPD) is a public health problem. Interprofessional collaboration and health promotion interventions such as exercise training, education, and behaviour change are cost effective, have a good effect on health status, and are recommended in COPD treatment guidelines. There is a gap between the guidelines and the healthcare available to people with COPD. The aim of this study was to increase the understanding of what shapes the provision of primary care services to people with COPD and what healthcare is offered to them from the perspective of healthcare professionals and managers. The study was conducted in primary care in a Swedish county council during January to June 2015. A qualitatively driven mixed methods design was applied. Qualitative and quantitative findings were merged into a joint analysis. Interviews for the qualitative component were performed with healthcare professionals (n = 14) from two primary care centres and analysed with qualitative content analysis. Two questionnaires were used for the quantitative component; one was answered by senior managers or COPD nurses at primary care centres (n = 26) in the county council and the other was answered by healthcare professionals (n = 18) at two primary care centres. The questionnaire data were analysed with descriptive statistics. The analysis gave rise to the overarching theme building COPD care on shaky ground. This represents professionals driven to build a supportive COPD care on 'shaky' organisational ground in a fragmented and non-compliant healthcare organisation. The shaky ground is further represented by uninformed patients with a complex disease, which is surrounded with shame. The professionals are autonomous and pragmatic, used to taking responsibility for their work, and with limited involvement of the management. They wish to provide high quality COPD care with interprofessional collaboration, but they lack competence and are hindered by

  17. A grounded theory for unaccompanied foreign minors in Italy: the case study of Egyptian minors

    Directory of Open Access Journals (Sweden)

    Lavinia Bianchi

    2017-06-01

    Full Text Available The article suggests to share a research first emerging categories according to methodological universe of the "Grounded Theory" based on a mental construction/orientation process. The main target is to investigate in the educational relationship between an unaccompanied minor (MSNA and his educator, and so has also to consider the progressive changes in the learning of the language and the corresponding humanization of the same, so well the continued definition and shared construction of the intercultural practice. At this stage of doctoral research, some categories are emerging that are particularly pertinent to the Egyptian participants in the study. The egyptians are the main nationality present in italian system of host. The theory which is emergeting will be a scratch theory and has not a validation target of preconceived hypothesis.

  18. A 14-day ground-based hypokinesia study in nonhuman primates: A compilation of results

    Science.gov (United States)

    Kazarian, L.; Cann, C. E.; Parfitt, M.; Simmons, D.; Morey-Holton, E.

    1981-01-01

    A 14 day ground based hypokinesia study with rhesus monkeys was conducted to determine if a spaceflight of similar duration might affect bone remodeling and calcium homeostatis. The monkeys were placed in total body casts and sacrificed either immediately upon decasting or 14 days after decasting. Changes in vertebral strength were noted and further deterioration of bone strength continued during the recovery phase. Resorption in the vertebrae increased dramatically while formation decreased. Cortical bone formation was impaired in the long bones. The immobilized animals showed a progressive decrease in total serum calcium which rebounded upon remobilization. Most mandibular parameters remained unchanged during casting except for retardation of osteon birth or maturation rate and density distribution of matrix and mineral moieties.

  19. Optimum metallic-bond scheme: Theoretical study ofgeometric structures for ground-state sodium clusters

    Institute of Scientific and Technical Information of China (English)

    苏长荣; 李家明

    2002-01-01

    We present an optimum metallic-bond scheme to study the geometric structures of sodium clusters Nan (n≤15) systematically by combining the characteristics of metallic bonds and the first principle molecular dynamics simulation. The scheme provides an optimum way to examine almost all stable structures of sodium clusters and to determine their ground state structures. It is interesting to note that for the larger sodium clusters (13≤n≤15), there are some plane-like substructures on their surfaces, which resemble the fragments of the (110) plane with the highest atomic area density in the bulk bcc sodium crystal. We also propose a possible way to understand the formation of large icosahedral sodium clusters (1500<n<22000).

  20. Decision-making processes for the self-management of persistent pain: a grounded theory study.

    Science.gov (United States)

    Fenwick, Clare; Chaboyer, Wendy; St John, Winsome

    2012-08-01

    Persistent pain negatively impacts upon the individual suffering this condition. Almost all care related to persistent pain is self-managed. Decision-making is a critical skill of the self-manager and without these skills it would be improbable that effective self-management would emerge. However, current theories regarding decision-making and self-management have not adequately accounted for the many difficulties faced by individuals enduring persistent pain and the consequences of these experiences for the decision-maker. This grounded theory study revealed that individuals will transform into three distinct types of decision-makers using three different styles of decision-making in response to the many and varied problems related to the experience of persistent pain. These findings will provide nurses with valuable information to better equip individuals with persistent pain through the decision-making processes necessary for successful self-management.

  1. An Archaeological Curation-Needs Assessment for Fort Irwin, Naval Air Station, North Island, Edwards Air Force Base, Marine Corps Air-Ground Combat Center, Twentynine Palms

    Science.gov (United States)

    1997-01-01

    Management of Archaeological Collections (MCX-CMAC), located at the St. Louis District, conducted an investigation of all archaeological materials and...evidence documenting widespread deterioration and neglect of many of the Air Force, Army, and Navy archaeological collections. None of the 18...repositories are in full compliance with 36 CFR Part 79 (Curation of Federally-Owned and Administered Archaeological Collections) and one-half were not designed for, or adapted to, the requirements of a modem curation center.

  2. Can nurse teachers manage student incivility by guided democracy? A grounded theory study.

    Science.gov (United States)

    Rad, Mostafa; Karimi Moonaghi, Hossein; Ildarabadi, Eshagh

    2017-07-17

    Managing incivility in academic settings is among the basic concerns and challenges of most educational systems, including nursing education. Incivility management cannot be considered devoid of disruptive behaviors. However, incivility management is a complexphenomenon upon which few studies are conducted. The present study aims at discovering teachers and students' experiences regarding incivility and developing an approach to manage nursing students' incivility. The present study was conducted based on the qualitative research design of the grounded theory methodology. This study was conducted at schools of nursing in academic settings in Iran. Study participants in the present study include nurse teachers (N=20) and nursing students (N=9). In-depth semi-structured interviews were conducted using theoretical and purposive sampling. Constant comparative analysis was used for data analysis. The results include four main categories; (1) deterioration of learning; (2) dominant individual and organisational culture; (3) guided democracy; and (4) movement toward professionalism. Guided democracy is recognised as the main basic psychosocial process for incivility management. Incivility management is pursued to help learners develop professional performance. As indicated by the results of the present study, guided democracy is an effective strategy for incivility management in nursing education. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  3. Can nurse teachers manage student incivility by guided democracy? A grounded theory study

    Science.gov (United States)

    Rad, Mostafa; Ildarabadi, Eshagh

    2017-01-01

    Introduction Managing incivility in academic settings is among the basic concerns and challenges of most educational systems, including nursing education. Incivility management cannot be considered devoid of disruptive behaviors. However, incivility management is a complexphenomenon upon which few studies are conducted. Objectives The present study aims at discovering teachers and students’ experiences regarding incivility and developing an approach to manage nursing students’ incivility. Design The present study was conducted based on the qualitative research design of the grounded theory methodology. Settings This study was conducted at schools of nursing in academic settings in Iran. Participants Study participants in the present study include nurse teachers (N=20) and nursing students (N=9). Method In-depth semi-structured interviews were conducted using theoretical and purposive sampling. Constant comparative analysis was used for data analysis. Results The results include four main categories; (1) deterioration of learning; (2) dominant individual and organisational culture; (3) guided democracy; and (4) movement toward professionalism. Guided democracy is recognised as the main basic psychosocial process for incivility management. Conclusions Incivility management is pursued to help learners develop professional performance. As indicated by the results of the present study, guided democracy is an effective strategy for incivility management in nursing education. PMID:28716787

  4. Dynamical response of the Galileo Galilei on the ground rotor to test the equivalence principle: Theory, simulation, and experiment. II. The rejection of common mode forces

    Science.gov (United States)

    Comandi, G. L.; Toncelli, R.; Chiofalo, M. L.; Bramanti, D.; Nobili, A. M.

    2006-03-01

    "Galileo Galilei on the ground" (GGG) is a fast rotating differential accelerometer designed to test the equivalence principle (EP). Its sensitivity to differential effects, such as the effect of an EP violation, depends crucially on the capability of the accelerometer to reject all effects acting in common mode. By applying the theoretical and simulation methods reported in Part I of this work, and tested therein against experimental data, we predict the occurrence of an enhanced common mode rejection of the GGG accelerometer. We demonstrate that the best rejection of common mode disturbances can be tuned in a controlled way by varying the spin frequency of the GGG rotor.

  5. How People Reason: A Grounded Theory Study of Scientific Reasoning about Global Climate Change

    Science.gov (United States)

    Liu, Shiyu

    Scientific reasoning is crucial in both scientific inquiry and everyday life. While the majority of researchers have studied "how people reason" by focusing on their cognitive processes, factors related to the underpinnings of scientific reasoning are still under-researched. The present study aimed to develop a grounded theory that captures not only the cognitive processes during reasoning but also their underpinnings. In particular, the grounded theory and phenomenographic methodologies were integrated to explore how undergraduate students reason about competing theories and evidence on global climate change. Twenty-six undergraduate students were recruited through theoretical sampling. Constant comparative analysis of responses from interviews and written assessments revealed that participants were mostly drawn to the surface features when reasoning about evidence. While prior knowledge might not directly contribute to participants' performance on evidence evaluation, it affected their level of engagement when reading and evaluating competing arguments on climate issues. More importantly, even though all participants acknowledged the relative correctness of multiple perspectives, they predominantly favored arguments that supported their own beliefs with weak scientific reasoning about the opposing arguments. Additionally, factors such as personal interests, religious beliefs, and reading capacity were also found to have bearings on the way participants evaluated evidence and arguments. In all, this work contributes to the current endeavors in exploring the nature of scientific reasoning. Taking a holistic perspective, it provides an in-depth discussion of factors that may affect or relate to scientific reasoning processes. Furthermore, in comparison with traditional methods used in the literature, the methodological approach employed in this work brought an innovative insight into the investigation of scientific reasoning. Last but not least, this research may

  6. Ground-penetrating radar study of the Rahivere peat bog, eastern Estonia

    Directory of Open Access Journals (Sweden)

    Jüri Plado

    2011-03-01

    Full Text Available The current case study presents results of the ground-penetrating radar (GPR profiling at one of the Saadjärve drumlin field interstitial troughs, the Rahivere bog, eastern Estonia. The study was conducted in order to identify the bog morphology, and the thickness and geometry of the peat body. The method was also used to describe the applicability of GPR in the evaluation of the peat deposit reserve as the Rahivere bog belongs among the officially registered peat reserves. Fourteen GPR profiles, ~ 100 m apart and oriented perpendicular to the long axis of the depression, covering the bog and its surrounding areas, were acquired. In order to verify the radar image interpretation as well as to evaluate the velocity of electromagnetic waves in peat, a common source configuration was utilized and thirteen boreholes were drilled on the GPR profiles. A mean value of 0.036 m ns–1 corresponding to relative dielectric permittivity of 69.7 was used for the time–depth conversion. Radar images reveal major reflection from the peat–soil interface up to a depth of about 4 m, whereas drillings showed a maximum thickness of 4.5 m of peat. Minor reflections appear from the upper peat and mineral soil. According to the borehole data, undecomposed peat is underlain by decomposed one, but identifying them by GPR is complicated. Mineral soil consists of glaciolimnic silty sand in the peripheral areas of the trough, overlain by limnic clay in the central part. The calculated peat volumes (1 200 000 m3 were found to exceed the earlier estimation (979 000 m3 that was based solely on drilling data. Ground-penetrating radar, as a method that allows mapping horizontal continuity of the sub-peat interface in a non-destructive way, was found to provide detailed information for evaluating peat depth and extent.

  7. Study on the System Design of a Solar Assisted Ground Heat Pump System Using Dynamic Simulation

    Directory of Open Access Journals (Sweden)

    Min Gyung Yu

    2016-04-01

    Full Text Available Recently, the use of hybrid systems using multiple heat sources in buildings to ensure a stable energy supply and improve the system performance has gained attention. Among them, a heat pump system using both solar and ground heat was developed and various system configurations have been introduced. However, establishing a suitable design method for the solar-assisted ground heat pump (SAGHP system including a thermal storage tank is complicated and there are few quantitative studies on the detailed system configurations. Therefore, this study developed three SAGHP system design methods considering the design factors focused on the thermal storage tank. Using dynamic energy simulation code (TRNSYS 17, individual performance analysis models were developed and long-term quantitative analysis was carried out to suggest optimum design and operation methods. As a result, it was found that SYSTEM 2 which is a hybrid system with heat storage tank for only a solar system showed the highest average heat source temperature of 14.81 °C, which is about 11 °C higher than minimum temperature in SYSTEM 3. Furthermore, the best coefficient of performance (COP values of heat pump and system were 5.23 and 4.32 in SYSYEM 2, using high and stable solar heat from a thermal storage tank. Moreover, this paper considered five different geographical and climatic locations and the SAGHP system worked efficiently in having high solar radiation and cool climate zones and the system COP was 4.51 in the case of Winnipeg (Canada where the highest heating demand is required.

  8. Effects of ground and joint reaction force exercise on lumbar spine and femoral neck bone mineral density in postmenopausal women: a meta-analysis of randomized controlled trials

    Directory of Open Access Journals (Sweden)

    Kelley George A

    2012-09-01

    Full Text Available Abstract Background Low bone mineral density (BMD and subsequent fractures are a major public health problem in postmenopausal women. The purpose of this study was to use the aggregate data meta-analytic approach to examine the effects of ground (for example, walking and/or joint reaction (for example, strength training exercise on femoral neck (FN and lumbar spine (LS BMD in postmenopausal women. Methods The a priori inclusion criteria were: (1 randomized controlled trials, (2 exercise intervention ≥ 24 weeks, (3 comparative control group, (4 postmenopausal women, (5 participants not regularly active, i.e., less than 150 minutes of moderate intensity (3.0 to 5.9 metabolic equivalents weight bearing endurance activity per week, less than 75 minutes of vigorous intensity (> 6.0 metabolic equivalents weight bearing endurance activity per week, resistance training g was calculated for each FN and LS BMD result and pooled using random-effects models. Z-score alpha values, 95%confidence intervals (CI and number-needed-to-treat (NNT were calculated for pooled results. Heterogeneity was examined using Q and I2. Mixed-effects ANOVA and simple meta-regression were used to examine changes in FN and LS BMD according to selected categorical and continuous variables. Statistical significance was set at an alpha value ≤0.05 and a trend at >0.05 to ≤ 0.10. Results Small, statistically significant exercise minus control group improvements were found for both FN (28 g’s, 1632 participants, g = 0.288, 95% CI = 0.102, 0.474, p = 0.002, Q = 90.5, p I2 = 70.1%, NNT = 6 and LS (28 g’s, 1504 participants, g = 0.179, 95% CI = −0.003, 0.361, p = 0.05, Q = 77.7, p I2 = 65.3%, NNT = 6 BMD. Clinically, it was estimated that the overall changes in FN and LS would reduce the 20-year relative risk of osteoporotic fracture at any site by approximately 11% and 10%, respectively. None of the mixed

  9. Dispersion Forces

    CERN Document Server

    Buhmann, Stefan Yoshi

    2012-01-01

    In this book, a modern unified theory of dispersion forces on atoms and bodies is presented which covers a broad range of advanced aspects and scenarios. Macroscopic quantum electrodynamics is shown to provide a powerful framework for dispersion forces which allows for discussing general properties like their non-additivity and the relation between microscopic and macroscopic interactions. It is demonstrated how the general results can be used to obtain dispersion forces on atoms in the presence of bodies of various shapes and materials. Starting with a brief recapitulation of volume I, this volume II deals especially with bodies of irregular shapes, universal scaling laws, dynamical forces on excited atoms, enhanced forces in cavity quantum electrodynamics, non-equilibrium forces in thermal environments and quantum friction. The book gives both the specialist and those new to the field a thorough overview over recent results in the field. It provides a toolbox for studying dispersion forces in various contex...

  10. Methods and applications of electrical simulation in ground-water studies in the lower Arkansas and Verdigris River Valleys, Arkansas and Oklahoma

    Science.gov (United States)

    Bedinger, M.S.; Reed, J.E.; Wells, C.J.; Swafford, B.F.

    1970-01-01

    The Arkansas River Multiple-Purpose Plan will provide year-round navigation on the Arkansas River from near its mouth to Muskogee, Okla., and on the Verdigris River from Muskogee to Catoosa, Okla. The altered regimen in the Arkansas and Verdigris Rivers will affect ground-water conditions in the adjacent alluvial aquifers. In 1957 the U.S. Geological Survey and U.S. Army Corps of Engineers entered into a cooperative agreement for a comprehensive ground-water study of the lower Arkansas and Verdigris River valleys. At the request of the Corps of Engineers, the Geological Survey agreed to provide (1) basic ground-water data before, during, and after construction of the Multiple-Purpose Plan and (2) interpretation and projections of postconstruction ground-water conditions. The data collected were used by the Corps of Engineers in preliminary foundation and excavation estimates and by the Geological Survey as the basis for defining the hydrologic properties of, and the ground-water conditions in, the aquifer. The projections of postconstruction ground-water conditions were used by the Corps of Engineers in the planning, design, construction, and operation of the Multiple-Purpose Plan. Analysis and projections of ground-water conditions were made by use of electrical analog models. These models use the analogy between the flow of electricity in a resistance-capacitance circuit and the flow of a liquid in a porous and permeable medium. Verification provides a test of the validity of the analog to perform as the aquifer would, within the range of historic forces. The verification process consists of simulating the action of historic forces which have acted upon the aquifer and of duplicating the aquifer response with the analog. The areal distribution of accretion can be treated as an unknown and can be determined by analog simulation of the piezometric surface in an aquifer. Comparison of accretion with depth to piezometric surface below land surface shows that

  11. Postural And Eye-Positional Effects On Human Biting Force: An Experimental Study

    Directory of Open Access Journals (Sweden)

    Altay Tabancacı

    2012-06-01

    Full Text Available Muscle groups affected on biting force are called temporal muscle as a major and masseter muscle as a minor. According to the human posture stability, forces of these muscles vary with the force directions. In this case, experimental investigation is strictly important such that biting force under different postural and eye- positional situations is changed. In this study, seven-male and seven-female within the age-range of 17-24 are considered corresponding to having with restorated molar tooth and without that type of tooth. With the help of specially designed biting fork, different posture- and eye-positions are investigated for experimental biting force analysis. Changes in eye-positions are not indicated significant difference for all postural positions. On one hand, it is obtained that biting force of no-filling tooth in men becomes maximum if facial muscles give full effort to biting. On the other hand, effect of facial muscles for women is not clearly noticed depending on the postural differences.

  12. A computational study of the aerodynamic forces and power requirements of dragonfly Aeschna juncea hovering

    CERN Document Server

    Sun, M; Sun, Mao; Lan, Shi Long

    2004-01-01

    Aerodynamic force generation and mechanical power requirements of a dragonfly (Aeschna juncea) in hovering flight are studied. The method of numerically solving the Navier-Stokes equations in moving overset grids is used. There are two large vertical force peaks in one flapping cycle. One is in the first half of the cycle, which is mainly due to the hindwings in their downstroke; the other is in the second half of the cycle, which is mainly due to the forewings in their downstroke. Hovering with a large stroke plane angle, the dragonfly uses drag as a major source for its weight supporting force (approximately 65% of the total vertical force is contributed by the drag and 35% by the lift of the wings). The vertical force coefficient of a wing is twice as large as the quasi-steady value. The interaction between the fore- and hindwings is not very strong and is detrimental to the vertical force generation. Compared with the case of a single wing in the same motion, the interaction effect reduces the vertical fo...

  13. Force majeure clauses and the threat of nuclear disaster. A Japanese case study

    Energy Technology Data Exchange (ETDEWEB)

    Guderian, Stephan Michael

    2011-07-22

    Force majeure clauses can be found in any commercial contract. Though more or less clear guidelines for the applicability of force majeure (clauses) exist in the form of international and national law, the applicability and enforceability of force majeure clauses with respect to nuclear incidents or disasters, however, remain ambiguous. Until the Japanese nuclear disaster, no major trade region was affected by any of the historical nuclear incidents. This case-study is based on the events surrounding the Tohoku earthquake, respective tsunami and nuclear incidents, especially at the Daiichi NPP and radiological contamination released there. The applicability and enforceability of force majeure clauses with their wide legal and economical implications are analyzed and evaluated according to the CISG and national domestic Japanese law. It is found that the assertion of force majeure is generally highly fact-specific and circumstance-sensitive. In general, the potential of nuclear disaster as an event triggering the force majeure defence is clearly evident, according to both international and Japanese law. Any claim must, however, be substantiated according to the principles of the different legal regimes under which the contract falls. In consequence, a company located within the evacuated areas will probably be able to successfully assert for majeure, whilst the success of any other claim will depend on the presentation of evidence, such as radiation levels and its effects in hindering performance of contractual obligations.

  14. Maximum clenching force of patients with moderate loss of posterior tooth support: a pilot study.

    Science.gov (United States)

    Gibbs, Charles H; Anusavice, Kenneth J; Young, Henry M; Jones, Jack S; Esquivel-Upshaw, Josephine F

    2002-11-01

    Patients who have lost moderate posterior tooth support may also lose clenching force as a result of sensitivity to increased loading to the remaining teeth and possibly a loss of muscle strength, because clenching forces are limited to avoid stress to the remaining teeth. Few studies have correlated moderate posterior tooth loss with maximum clenching force. The purpose of this pilot study was to test the hypothesis that moderate loss of posterior tooth support will have a significant effect on maximum clenching force. The maximum clenching force of 44 adults, ages 28 to 76 (mean 46), with posterior tooth loss was compared with the maximum clenching force of a control group of 20 healthy full dentition adults, ages 18 to 55 (mean 30), by use of a bilateral strain-gauged transducer. The transducer consisted of 2 stainless steel plates separated by a steel sphere that balanced occlusal forces between right and left sides. Acrylic resin pads were fabricated for each patient to protect the cusps of the teeth. The overall accuracy was found to be within 2.3% of full scale over a range of 0 to 4000 N (0 to 900 lbs). The calibration reliability of the system was checked frequently by use of a dead weight of 222 N (50 lbs). Clenching forces were supported by first and second molars and second premolars when possible. The instrumentation, methods, and operator were the same for both groups. A 2-tailed Student t test (alpha=0.01) and a pooled estimate of the mean were used to determine possible statistical significance. To test for possible correlations between clenching force and lost tooth support and between clenching force and age, a linear regression correlation coefficient R was calculated. For the 44 subjects with posterior tooth loss, the mean clenching force was 462 N (104 lbs), with a range of 98 to 1031 N (22 to 232 lbs). This compares with a mean of 720 N (162 lbs) with a range of 244 to 1243 N (55 to 280 lbs) for the full-dentition subjects. A 2-tailed t test

  15. Case Study for the ARRA-Funded Ground Source Heat Pump Demonstration at Ball State University

    Energy Technology Data Exchange (ETDEWEB)

    Im, Piljae [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Liu, Xiaobing [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Henderson, Jr., Hugh [CDH Energy Corp., Beijing (China)

    2016-12-01

    With funding provided by the American Recovery and Reinvestment Act (ARRA), 26 ground-source heat pump (GSHP) projects were competitively selected in 2009 to demonstrate the benefits of GSHP systems and innovative technologies for cost reduction and/or performance improvement. One of the selected demonstration projects is a district central GSHP system installed at Ball State University (BSU) in Muncie, IN. Prior to implementing the district GSHP system, 47 major buildings in BSU were served by a central steam plant with four coal-fired and three natural-gas-fired steam boilers. Cooling was provided by five water-cooled centrifugal chillers at the District Energy Station South (DESS). The new district GSHP system replaced the existing coal-fired steam boilers and conventional water-cooled chillers. It uses ground-coupled heat recovery (HR) chillers to meet the simultaneous heating and cooling demands of the campus. The actual performance of the GSHP system was analyzed based on available measured data from August 2015 through July 2016, construction drawings, maintenance records, personal communications, and construction costs. Since Phase 1 was funded in part by the ARRA grant, it is the focus of this case study. The annual energy consumption of the GSHP system was calculated based on the available measured data and other related information. It was compared with the performance of a baseline scenario— a conventional water-cooled chiller and natural-gas-fired boiler system, both of which meet the minimum energy efficiencies allowed by the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE 90.1-2013). The comparison was made to determine source energy savings, energy cost savings, and CO2 emission reductions achieved by the GSHP system. A cost analysis was performed to evaluate the simple payback of the GSHP system. The following sections summarize the results of the analysis, the lessons learned, and recommendations for improvement

  16. A Grounded Theory Study of the Mentoring Process Involved With Undergraduate Athletic Training Students.

    Science.gov (United States)

    Pitney, William A; Ehlers, Greg G

    2004-12-01

    OBJECTIVE: To gain insight regarding the mentoring processes involving students enrolled in athletic training education programs and to create a mentoring model. DESIGN AND SETTING: We conducted a grounded theory study with students and mentors currently affiliated with 1 of 2 of the athletic training education programs accredited by the Commission on Accreditation of Allied Health Education Programs. PARTICIPANTS: Sixteen interviews were conducted, 13 with athletic training students and 3 with individuals identified as mentors. The students ranged in age from 20 to 24 years, with an average of 21.6 years. The mentors ranged from 24 to 38 years of age, with an average of 33.3 years. Participants were purposefully selected based on theoretic sampling and availability. DATA ANALYSIS: The transcribed interviews were analyzed using open-, axial-, and selective-coding procedures. Member checks, peer debriefings, and triangulation were used to ensure trustworthiness. RESULTS: Students who acknowledged having a mentor overwhelmingly identified their clinical instructor in this role. The open-coding procedures produced 3 categories: (1) mentoring prerequisites, (2) interpersonal foundations, and (3) educational dimensions. Mentoring prerequisites included accessibility, approachability, and protege initiative. Interpersonal foundations involved the mentor and protege having congruent values, trust, and a personal relationship. The educational dimensions category involved the mentor facilitating knowledge and skill development, encouraging professional perspectives, and individualizing learning. Although a student-certified athletic trainer relationship can be grounded in either interpersonal or educational aspects, the data support the occurrence of an authentic mentoring relationship when the dimensions coalesced. CONCLUSIONS: Potential mentors must not only be accessible but also approachable by a prospective protege. Mentoring takes initiative on behalf of a student and

  17. Characterizing topological order by studying the ground States on an infinite cylinder.

    Science.gov (United States)

    Cincio, L; Vidal, G

    2013-02-08

    Given a microscopic lattice Hamiltonian for a topologically ordered phase, we propose a numerical approach to characterize its emergent anyon model and, in a chiral phase, also its gapless edge theory. First, a tensor network representation of a complete, orthonormal set of ground states on a cylinder of infinite length and finite width is obtained through numerical optimization. Each of these ground states is argued to have a different anyonic flux threading through the cylinder. Then a quasiorthogonal basis on the torus is produced by chopping off and reconnecting the tensor network representation on the cylinder. From these two bases, and by using a number of previous results, most notably the recent proposal of Y. Zhang et al. [Phys. Rev. B 85, 235151 (2012)] to extract the modular U and S matrices, we obtain (i) a complete list of anyon types i, together with (ii) their quantum dimensions d(i) and total quantum dimension D, (iii) their fusion rules N(ij)(k), (iv) their mutual statistics, as encoded in the off-diagonal entries S(ij) of S, (v) their self-statistics or topological spins θ(i), (vi) the topological central charge c of the anyon model, and, in a chiral phase (vii) the low energy spectrum of each sector of the boundary conformal field theory. As a concrete application, we study the hard-core boson Haldane model by using the two-dimensional density matrix renormalization group. A thorough characterization of its universal bulk and edge properties unambiguously shows that it realizes a ν=1/2 bosonic fractional quantum Hall state.

  18. Opening up to learning spiritual care of patients: a grounded theory study of nursing students.

    Science.gov (United States)

    Giske, Tove; Cone, Pamela H

    2012-07-01

    To determine undergraduate nursing students' perspectives on spiritual care and how they learn to assess and provide spiritual care to patients. Nursing is concerned with holistic care. Systematic teaching and supervision of students to prepare them to assist patients spiritually is a growing focus. However, there is limited consensus about the competences students need to develop and little is written related to students learning processes. Grounded theory was used to identify students' main concern and develop a substantive grounded theory. Data collected during semi-structured interviews at three Norwegian University Colleges in eight focus groups with 42 undergraduate nursing students were analysed through constant comparison of transcribed interviews until categories were saturated. The participants' main concern was 'How to create a professional relationship with patients and maintain rapport when spiritual concerns were recognised'. Participants resolved this by 'Opening up to learning spiritual care'. This basic social process has three iterative phases that develop as a spiral throughout the nursing programme: 'Preparing for connection', 'Connecting with and supporting patients' and 'Reflecting on experiences'. Nurses need a wide range of competences to fulfil the nursing focus on holistic patient care. Nursing education should prepare students to recognise and act on spiritual cues. A trusting relationship and respectful and sensitive communication assist students to discover what is important to patients. An educational focus on spiritual and existential themes throughout the nursing programme will assist students to integrate theoretical learning into clinical practice. Study participants reported seeing few role models in clinical settings. Making spiritual assessment and interventions more visible and explicit would facilitate student learning in clinical practice. Evaluative discussions in clinical settings that include spiritual concerns will

  19. The persistence of women in STEM: A constructivist grounded theory study

    Science.gov (United States)

    Gamm, Ryan

    Men and women have reached relative parity in most sectors of the United States workforce. Yet women remain underrepresented in science, technology, engineering, and mathematics (STEM) fields (AAUW, 2010). Underrepresentation persists despite several decades of research, legislation, and intervention focused on gender equality in STEM fields (Clewell, 2002). The underrepresentation or shortage of women in STEM fields is identifiable primarily in degree attainment, in workforce demographics, and in a gender wage gap. Situated in constructivist grounded theory, this study asks how do women in science, technology, engineering, and mathematics (STEM) fields, particularly those in established career positions, persist when encountering personal and institutional barriers, resistance, and hostility? I use an interpretive-constructivist lens to conduct a grounded theory study exploring the experiences of women who persist in STEM fields, their relation to extant literature on this topic, and the connections to K-12 education practices, specifically curriculum. To understand the connections to curriculum I employ Pinar's (2012) method of currere. Pinar (2012) contends currere "provides a strategy for students of curriculum to study the relations between academic knowledge and life history in the interests of self-understanding and social reconstruction" (p.44). This qualitative study explored nine female STEM workers stories of persistence as each respondent works in STEM fields were gender parity has yet to be established. This study presents a substantive theory: As women persist in STEM fields they reframe themselves to be situated in the overlapping intersection of the social processes that correspond to "engagement" and "persistence." This reframing is possible by interpreting one's present day circumstances by independently removing oneself from current circumstances to understand the cumulative effect of both past and present. The findings highlight the importance

  20. Molecular dynamics study of the potential of mean force of SDS aggregates

    Science.gov (United States)

    Kawada, Shinji; Fujimoto, Kazushi; Yoshii, Noriyuki; Okazaki, Susumu

    2017-08-01

    In our previous study, all-atomistic molecular dynamics (MD) calculations have been carried out for the aggregation of ionic sodium dodecyl sulfate in water [S. Kawada et al., Chem. Phys. Lett. 646, 36 (2016)]. Aggregates of 20-30 dodecyl sulfate ions were formed within a short MD run for 10 ns. However, further aggregation did not occur despite a long MD calculation for more than 100 ns. This suggests that strong electrostatic repulsive interactions between the aggregates prevent the fusion of the aggregates. In the present study, mean force and potential of mean force acting between two aggregates with aggregation number N = 30 were evaluated as a function of their separation by MD calculations. The repulsive force becomes strong with decreasing distance between the two aggregates before they merge into one. An origin of the repulsive force is an electric double layer formed by the sulfate group and counter sodium ions. Strength of the repulsive force is in good agreement with the theoretical value given by the Derjaguin-Landau-Verwey-Overbeek (DLVO) theory. Once the aggregates establish contact, the force between them turns to be a large attractive force that can be explained by the interfacial tension. In order to form a single micelle from the two aggregates, it is necessary for them to climb over a free energy barrier of 23 kJ/mol. Once, the barrier is overcome, the micelle is stabilized by ˜200 kJ/mol. The time constant of aggregation evaluated from the calculated free energy barrier was about 28 μs at the concentration in our previous study.