WorldWideScience

Sample records for solid golf ball

  1. Golf Ball

    Science.gov (United States)

    1998-01-01

    The Ultra 500 Series golf balls, introduced in 1995 by Wilson Sporting Goods Company, has 500 dimples arranged in a pattern of 60 spherical triangles. The design employs NASA's aerodynamics technology analysis of air loads of the tank and Shuttle orbiter that was performed under the Space Shuttle External Tank program. According to Wilson, this technology provides 'the most symmetrical ball surface available, sustaining initial velocity longer and producing the most stable ball flight for unmatched accuracy and distance.' The dimples are in three sizes, shapes and depths mathematically positioned for the best effect. The selection of dimples and their placement optimizes the interaction of opposing forces of lift and drag. Large dimples reduce air drag, enhance lift, and maintain spin for distance. Small dimples prevent excessive lift that destabilizes the ball flight and the medium size dimples blend the other two.

  2. 2012 Problem 15: Frustrating Golf Ball

    Science.gov (United States)

    Huang, Shan; Zhu, Zheyuan; Gao, Wenli; Wang, Sihui

    2015-10-01

    This paper studies the condition for a golf ball to escape from a hole. The two determining factors are the ball's initial velocity v0 and its deviation from the center of the hole d. There is a critical escaping velocity vc for every deviation d. The ball's motion is analyzed by calculating the change of velocity whenever the ball collides with the hole. The critical conditions predicted by our theory are verified through experiment.

  3. Flight trajectory of a rotating golf ball with grooves

    Science.gov (United States)

    Baek, Moonheum; Kim, Jooha; Choi, Haecheon

    2014-11-01

    Dimples are known to reduce drag on a sphere by the amount of 50% as compared to a smooth surface. Despite the advantage of reducing drag, dimples deteriorate the putting accuracy owing to their sharp edges. To minimize this putting error but maintain the same flight distance, we have devised a grooved golf ball (called G ball hereafter) for several years. In this study, we modify the shape and pattern of grooves, and investigate the flow characteristics of the G ball by performing wind-tunnel experiments at the Reynolds numbers of 0 . 5 ×105 - 2 . 5 ×105 and the spin ratios (ratio of surface velocity to the free-stream velocity) of 0 - 0.6 that include the real golf-ball velocity and rotational speed. We measure the drag and lift forces on the rotating G ball and compare them with those of a smooth ball and two well-known dimpled balls. The lift-to-drag ratio of the G ball is much higher than that of a smooth ball and is in between those of the two dimpled balls. The trajectories of flying golf balls are computed. The flight distance of G ball is almost the same as that of one dimpled ball but slightly shorter than that of the other dimpled ball. The fluid-dynamic aspects of these differences will be discussed at the talk. Supported by 2011-0028032, 2014M3C1B1033980.

  4. Assessment of head injury of children due to golf ball impact.

    Science.gov (United States)

    Lee, Heow Pueh; Wang, Fang

    2010-10-01

    Head trauma injury due to impact by a flying golf ball is one of the most severe possible injury accidents on the golf course. Numerical simulations based on the finite element method are presented to investigate head injury in children due to impact by a flying golf ball. The stress and energy flow patterns in a head model during the golf ball impact are computed for various combinations of striking speed, falling angle of the golf ball before impact, and impact location. It is found that a child is more prone to head injury due to golf ball impact on the frontal and side/temporal areas. The simulated results are found to conform to the clinical reports on children's head injuries from flying golf balls.

  5. 76 FR 66328 - Callaway Golf Ball Operations, Inc., Including On-Site Leased Workers From Reliable Temp Services...

    Science.gov (United States)

    2011-10-26

    ... DEPARTMENT OF LABOR Employment and Training Administration [TA-W-80,110] Callaway Golf Ball... Golf Ball Operations, Inc., including on-site leased workers from Reliable Temp Services, Inc., and... production of golf balls. The notice was published in the Federal Register on July 8, 2011 (76 FR 40401). At...

  6. On the origin of the drag force on golf balls

    Science.gov (United States)

    Balaras, Elias; Beratlis, Nikolaos; Squires, Kyle

    2017-11-01

    It is well establised that dimples accelerate the drag-crisis on a sphere. The result of the early drag-crisis is a reduction of the drag coefficient by more than a factor of two when compared to a smooth sphere at the same Reynolds number. However, when the drag coefficients for smooth and dimpled spheres in the supercritical regime are compared, the latter is higher by a factor of two to three. To understand the origin of this behavior we conducted direct numerical simulations of the flow around a dimpled sphere, which is similar to commercially available golf balls, in the supercritical regime. By comparing the results to those for a smooth sphere it is found that dimples, although effective in accelerating the drag crisis, impose a local drag-penalty, which contributes significantly to the overall drag force. This finding challenges the broadly accepted view, that the dimples only indirectly affect the drag force on a golf ball by manipulating the structure of the turbulent boundary layer near the wall and consequently affect global separation. Within this view, typically the penalty on the drag force imposed by the dimples is assumed to be small and coming primarily from skin friction. The direct numerical simulations we will report reveal a very different picture.

  7. Golf Balls, Boomerangs and Asteroids The Impact of Missiles on Society

    CERN Document Server

    Kaye, Brian H

    1996-01-01

    Exciting reading for anyone with a curious mind!. 'Walking one day by a golf course in Wisconsin, I was startled to hear a sharp bang as a golf ball narrowly missed my head and hit a tree. My companion cheerfully remarked, 'That could have killed you, you know.' I picked up the innocent looking little white ball and looked at it with new respect.'. Prompted by this perilous experience, Brian Kaye has written a delightful and informative book on the design and behavior of different kinds of missiles from golf balls, arrows, and slingshots to comets and rockets to outer space. You'll learn about

  8. Numerical study on the aerodynamics of a golf ball and its comparison with a smooth sphere

    Science.gov (United States)

    Li, Jing; Tsubokura, Makoto; Tsunoda, Masaya

    2014-11-01

    The present study has numerically investigated the flow over a golf ball and a smooth sphere by conducting large-eddy simulation (LES) using hundreds of millions of unstructured elements. Simulations were conducted at various Reynolds numbers ranging from the subcritical to the supercritical regimes. Special attention was paid to the phenomenon of drag crisis as well as the effect of surface roughness on the drag crisis. The simulation result shows that the surface roughness introduced by the dimples of the golf ball causes a local instability of the flow around the ball and subsequently leads to a momentum transfer in the near-wall region inside the dimples. The flow with high momentum in the near-wall region travels further downstream, which consequently results in the drag crisis occurring at a relatively lower Reynolds number compared with that of the smooth sphere. Moreover, the Magnus effect resulting from the rotating motion of a sphere was also one of the main concerns in this study. The simulation result shows that lift forces are imposed on both the rotating smooth sphere and rotating golf ball. For most cases the lift force points to the positive direction, however, the negative lift force appears also under certain conditions.

  9. The Influence of Face Angle and Club Path on the Resultant Launch Angle of a Golf Ball

    Directory of Open Access Journals (Sweden)

    Paul Wood

    2018-02-01

    Full Text Available A two-part experimental study was conducted in order to better understand how the delivered face angle and club path of a golf club influences the initial launch direction of a golf ball for various club types. A robust understanding of how these parameters influence the ball direction has implications for both coaches and club designers. The first study used a large sample of golfers hitting shots with different clubs. Initial ball direction was measured with a Foresight Sports camera system, while club delivery parameters were recorded with a Vicon motion capture system. The second study used a golf robot and Vision Research camera to measure club and ball parameters. Results from these experiments show that the launch direction fell closer to face angle than club path. The percent toward the face angle ranged from 61% to 83%, where 100% designates a launch angle entirely toward the face angle.

  10. Reliability of an experimental method to analyse the impact point on a golf ball during putting.

    Science.gov (United States)

    Richardson, Ashley K; Mitchell, Andrew C S; Hughes, Gerwyn

    2015-06-01

    This study aimed to examine the reliability of an experimental method identifying the location of the impact point on a golf ball during putting. Forty trials were completed using a mechanical putting robot set to reproduce a putt of 3.2 m, with four different putter-ball combinations. After locating the centre of the dimple pattern (centroid) the following variables were tested; distance of the impact point from the centroid, angle of the impact point from the centroid and distance of the impact point from the centroid derived from the X, Y coordinates. Good to excellent reliability was demonstrated in all impact variables reflected in very strong relative (ICC = 0.98-1.00) and absolute reliability (SEM% = 0.9-4.3%). The highest SEM% observed was 7% for the angle of the impact point from the centroid. In conclusion, the experimental method was shown to be reliable at locating the centroid location of a golf ball, therefore allowing for the identification of the point of impact with the putter head and is suitable for use in subsequent studies.

  11. Visual and anatomic outcomes of golf ball-related ocular injuries.

    Science.gov (United States)

    Park, S J; Park, K H; Heo, J W; Woo, S J

    2014-03-01

    To investigate the characteristics and prognoses of golf ball-related ocular injuries (GROIs) using standardized terminology, classification, and scoring systems. Twenty-two GROI patients were assessed using the Birmingham Eye Trauma Terminology, Ocular Trauma Classification Group (OTCG) classification, and Ocular Trauma Score. Globe preservation and final visual acuity (FVA) were assessed according to the injury severity categorical designation. Fourteen patients were injured on golf courses and eight on driving ranges. Nine patients (40.9%) had open-globe injuries (five ruptures (22.7%), four penetrating injuries (18.2%)). All rupture cases required enucleation, whereas penetrating injury cases did not (the FVA ranged from 20/100 to no light perception). In open-globe injuries, wearing glasses protected against rupture (P=0.008). Thirteen patients sustained closed-globe injuries that were accompanied by lens subluxation (38.5%), choroidal rupture (30.8%), macular commotio retinae (38.5%), and traumatic optic neuropathy (7.7%). Twelve (54.5%) patients had orbital wall fractures. The mean number of related surgeries required was 1.5±1.7 across all patients. Eyes with GROIs had devastating FVA and globe preservation status, especially those with open-globe injuries. Observing golf rules and improving driving-range facilities are essential for preventing GROIs. Protective eyewear may reduce ocular damage from GROIs, especially globe rupture.

  12. Numerical investigation of the flow over a golf ball in the subcritical and supercritical regimes

    International Nuclear Information System (INIS)

    Smith, C.E.; Beratlis, N.; Balaras, E.; Squires, K.; Tsunoda, M.

    2010-01-01

    In order to understand the role of surface dimpling on the flow over a golf ball, direct numerical simulations (DNS) are conducted within the framework of an immersed boundary approach for two physical regimes. Computations of the flow over a non-rotating golf ball are reported for a subcritical flow at a Reynolds number of 2.5 x 10 4 and a supercritical case at a Reynolds number of 1.1 x 10 5 . Grid refinement studies for both Reynolds numbers indicated that characteristics of the subcritical flow could be captured using a mesh of 337 x 10 6 points, and for the supercritical case using a grid with 1.2 x 10 9 points. Flow visualizations reveal the differences in separation characteristics between the two Reynolds numbers. Profiles of the mean velocity indicate that the flow detaches completely at approximately 84 o in the subcritical case (measured from the stagnation point at the front of the ball), while in the supercritical regime there are alternating regions of reattachment and separation within dimples with complete detachment around 110 o . Energy spectra highlight frequencies associated with vortex formation over the dimples prior to complete detachment in the supercritical regime. Reynolds stresses quantify momentum transport in the near-wall region, showing that the axial stress increases around 90 o for the subcritical case. In the supercritical regime these stress components alternately increase and decrease, corresponding to local separation and reattachment. Prediction of the drag coefficient for both Reynolds numbers is in reasonable agreement with measurements.

  13. The relationship between the golf swing plane and ball impact characteristics using trajectory ellipse fitting.

    Science.gov (United States)

    Morrison, Andrew; McGrath, Denise; Wallace, Eric S

    2018-02-01

    The trajectory of the clubhead close to ball impact during the golf swing has previously been shown to be planar. However, the relationship between the plane orientation and the orientation characteristics of the clubhead at ball impact has yet to be defined. Fifty-two male golfers (27 high skilled, 25 intermediate skilled) hit 40 drives each in an indoor biomechanics laboratory. This study successfully fitted the trajectory of the clubhead near impact to an ellipse for each swing for players of different skill levels to help better explain this relationship. Additionally, the eccentricities of the ellipses were investigated for links to skill level. The trajectory of the clubhead was found to fit to an ellipse with RMSE of 1.2 mm. The eccentricity of the ellipse was found to be greater in the high-skilled golfers. The club path and angle of attack generated from the ellipse fitted clubhead trajectory were found to have a normalised bias-corrected RMSE of 2% and 3%, respectively. A set of "rule of thumb" values for the relationship between the club path, angle of attack and delivery plane angle was generated for use by coaches.

  14. Golf Club

    CERN Multimedia

    Golf Club

    2011-01-01

    Golf Initiation CERN Golf Club invites you to a golf initiation session in collaboration with the Albatross Golf Academy. Where: Les Serves Golf, St Genis (situated behind the CERN football and rugby pitches) When: 30-July 2011 at 16:00 On offer: An experienced golf professional will take you through the basics of hitting golf balls on the practice area. As part of a group of 3 players and accompanied by an experienced CERN golf club member you will play a round of golf on the small 5 hole practice course enabling you to get a true experience of the sport. You will finish with the a drink in the 19th hole and share your day’s experience with other participants and CERN golf club members. Inscriptions by email are now open and should be sent to Mats.Wilhelmsson@cern.ch. There are a limited number of places and participants will be welcomed on a first come first served basis. The cost of the session will be Euro15 and equipment and golf balls will be provided. Training or jogging shoes...

  15. Disc Golf: Teaching a Lifetime Activity

    Science.gov (United States)

    Eastham, Susan L.

    2015-01-01

    Disc golf is a lifetime activity that can be enjoyed by students of varying skill levels and abilities. Disc golf follows the principles of ball golf but is generally easier for students to play and enjoy success. The object of disc golf is similar to ball golf and involves throwing a disc from the teeing area to the target in as few throws as…

  16. The Optimal Golf Stroke

    DEFF Research Database (Denmark)

    Buchinger, Mikael; Durigen, Susan; Dahl, Johan Rambech

    2006-01-01

    The paper presents a preliminary investigation into aspects of the game of golf. A series of models is proposed for the golf stroke, the momentum transfer between club and ball and the flight of the ball.Numerical and asymptotic solutions are presented reproducing many of the features observed in...

  17. Video Golf

    Science.gov (United States)

    1995-01-01

    George Nauck of ENCORE!!! invented and markets the Advanced Range Performance (ARPM) Video Golf System for measuring the result of a golf swing. After Nauck requested their assistance, Marshall Space Flight Center scientists suggested video and image processing/computing technology, and provided leads on commercial companies that dealt with the pertinent technologies. Nauck contracted with Applied Research Inc. to develop a prototype. The system employs an elevated camera, which sits behind the tee and follows the flight of the ball down range, catching the point of impact and subsequent roll. Instant replay of the video on a PC monitor at the tee allows measurement of the carry and roll. The unit measures distance and deviation from the target line, as well as distance from the target when one is selected. The information serves as an immediate basis for making adjustments or as a record of skill level progress for golfers.

  18. Solid lubricant mass contact transfer technology usage for vacuum ball bearings longevity increasing

    Science.gov (United States)

    Arzymatov, B.; Deulin, E.

    2016-07-01

    A contact mass transfer technological method of solid lubricant deposition on components of vacuum ball bearings is presented. Physics-mathematical model of process contact mass transfer is being considered. The experimental results of ball bearings covered with solid lubricant longevity in vacuum are presented. It is shown that solid lubricant of contact mass transfer method deposition is prospective for ball bearing longevity increasing.

  19. Golf Injuries

    Science.gov (United States)

    ... Our Newsletter Donate Blog Skip breadcrumb navigation Preventing Golf Injuries Golf looks like an easy game to ... WHAT TYPES OF INJURIES ARE MOST COMMON IN GOLF? Acute injuries are usually the result of a ...

  20. 76 FR 58108 - Safety Zone; Ryder Cup Captain's Duel Golf Shot, Chicago River, Chicago, IL

    Science.gov (United States)

    2011-09-20

    ...-AA00 Safety Zone; Ryder Cup Captain's Duel Golf Shot, Chicago River, Chicago, IL AGENCY: Coast Guard... the Chicago River during a golfing event that will involve hitting golf balls from land onto a... vessels from the hazards associated with golf balls being hit from land onto a stationary barge in the...

  1. Solid charged-core model of ball lightning

    Science.gov (United States)

    Muldrew, D. B.

    2010-01-01

    In this study, ball lightning (BL) is assumed to have a solid, positively-charged core. According to this underlying assumption, the core is surrounded by a thin electron layer with a charge nearly equal in magnitude to that of the core. A vacuum exists between the core and the electron layer containing an intense electromagnetic (EM) field which is reflected and guided by the electron layer. The microwave EM field applies a ponderomotive force (radiation pressure) to the electrons preventing them from falling into the core. The energetic electrons ionize the air next to the electron layer forming a neutral plasma layer. The electric-field distributions and their associated frequencies in the ball are determined by applying boundary conditions to a differential equation given by Stratton (1941). It is then shown that the electron and plasma layers are sufficiently thick and dense to completely trap and guide the EM field. This model of BL is exceptional in that it can explain all or nearly all of the peculiar characteristics of BL. The ES energy associated with the core charge can be extremely large which can explain the observations that occasionally BL contains enormous energy. The mass of the core prevents the BL from rising like a helium-filled balloon - a problem with most plasma and burning-gas models. The positively charged core keeps the negatively charged electron layer from diffusing away, i.e. it holds the ball together; other models do not have a mechanism to do this. The high electrical charges on the core and in the electron layer explains why some people have been electrocuted by BL. Experiments indicate that BL radiates microwaves upon exploding and this is consistent with the model. The fact that this novel model of BL can explain these and other observations is strong evidence that the model should be taken seriously.

  2. The physics of golf

    CERN Document Server

    Jorgensen, Theodore P

    1999-01-01

    Improve your golf game by learning the underlying fundamentals of the golf swing in this acclaimed, unique contribution to the sport Finally, you’ll understand why shortening your backswing doesn’t substantially decrease clubhead velocity what components contribute to the optimal swing and what variations are acceptable how and why properly shifting your weight adds to distance why a golf ball behaves and spins as it does and much more Written by a physicist after some twenty years of research, Physics of Golf is the only book devoted exclusively to explaining the science behind a successful golf game Technical appendices offer details for the so inclined The revised and expanded second now offers you -new material on high-tech club designs -a complete new chapter on short putts -additional applications of physics to the problems every player faces "Jorgensen tells golfers what they ought to be doing and why, the correct technique according to the principles of physics" -Golf Weekly "…gives new insights...

  3. The science of golf

    CERN Document Server

    Wesson, John

    2009-01-01

    This book gives a scientific account of all aspects of the game of golf and answers the questions which occur to all who play the game. The mechanics of the swing and the impact of the club on the ball are explained. Together these decide the range of the ball - which is shown to be the most important factor for success. The aerodynamics of the ball's flight has several surprises, including the effects of dimples and spin. Understanding these effects allows a calculation of the ball's flight and explains how the range depends on the clubhead speed and the characteristics of the club. Putting is analyzed to find the optimum strategy and to understand how winds, slopes, and mud affect the run of the ball. Handicaps are perhaps the most discussed topic in golf and the book examines the handicaps system to identify their consequences in matches and competitions, with results which will surprise many players. The famous question - "what is the probability of a hole-in-one?" is discussed and a neat way of answering...

  4. Golf Club

    CERN Multimedia

    CERN Golf Club

    2017-01-01

    Would you like to learn a new sport and meet new people? The CERN Golf Club organises golf lessons for beginners starting in August or September. The lesson series consist of 6 lessons of 1h30 each week, in a group of 6 people and given by the instructor Cedric Steinmetz at the Jiva Hill golf course in Crozet: http://www.jivahillgolf.com The cost for the golf lessons is 40 euros for CERN employees or family members plus the golf club membership fee of 30 CHF. If you are interested in participating in these lessons or need more details, please contact us by email at: club-golf-committee@cern.ch

  5. Design and fabrication hazard stakes golf course polymeric foam material empty bunch (EFB) fiber reinforced

    Science.gov (United States)

    Zulfahmi; Syam, B.; Wirjosentono, B.

    2018-02-01

    A golf course with obstacles in the forms of water obstacle and lateral water obstacle marked with the stakes which are called golf course obstacle stake in this study. This study focused on the design and fabrication of the golf course obstacle stake with a solid cylindrical geometry using EFB fiber-reinforced polimeric foam composite materials. To obtain the EFB fiber which is free from fat content and other elements, EFB is soaked in the water with 1% (of the watre total volume) NaOH. The model of the mould designed is permanent mould that can be used for the further refabrication process. The mould was designed based on resin-compound paste materials with talc powder plus E-glass fiber to make the mould strong. The composition of polimeric foam materials comprised unsaturated resin Bqtn-Ex 157 (70%), blowing agent (10%), fiber (10%), and catalyst (10%). The process of casting the polimeric foam composit materials into the mould cavity should be at vertical casting position, accurate interval time of material stirring, and periodical casting. To find out the strength value of the golf course obstacle stake product, a model was made and simulated by using the software of Ansys workbench 14.0, an impact loading was given at the height of 400 mm and 460 mm with the variation of golf ball speed (USGA standard) v = 18 m/s, v = 35 m/s, v = 66.2 m/s, v = 70 m/s, and v = 78.2 m/s. The clarification showed that the biggest dynamic explicit loading impact of Fmax = 142.5 N at the height of 460 mm with the maximum golf ball speed of 78.2 m/s did not experience the hysteresis effect and inertia effect. The largest deformation area occurred at the golf ball speed v = 66.2 mm/s, that is 18.029 mm (time: 2.5514e-004) was only concentrated around the sectional area of contact point of impact, meaning that the golf course obstacle stakes made of EFB fiber-reinforced polymeric foam materials have the geometric functional strength that are able to absorb the energy of golf ball

  6. A comparison of the performance of solid and liquid lubricants in oscillating spacecraft ball bearings

    Science.gov (United States)

    Gill, S.

    1994-01-01

    The European Space Tribology Laboratory (ESTL) has been engaged in a program to compare the performance of oscillating ball bearings when lubricated by a number of space lubricants, both liquid and solid. The results have shown that mean torque levels are increased by up to a factor of five above the normal running torque, and that often torque peaks of even greater magnitudes are present at the ends of travel. It is believed that these effects are caused by a build-up of compacted debris in the contact zone, thus reducing the ball/race conformity ratio.

  7. BIOMEHANICAL MODEL OF THE GOLF SWING TECHNIQUE

    Directory of Open Access Journals (Sweden)

    Milan Čoh

    2011-08-01

    Full Text Available Golf is an extremely complex game which depends on a number of interconnected factors. One of the most important elements is undoubtedly the golf swing technique. High performance of the golf swing technique is generated by: the level of motor abilities, high degree of movement control, the level of movement structure stabilisation, morphological characteristics, inter- and intro-muscular coordination, motivation, and concentration. The golf swing technique was investigated using the biomechanical analysis method. Kinematic parameters were registered using two synchronised high-speed cameras at a frequency of 2,000 Hz. The sample of subjects consisted of three professional golf players. The study results showed a relatively high variability of the swing technique. The maximum velocity of the ball after a wood swing ranged from 233 to 227 km/h. The velocity of the ball after an iron swing was lower by 10 km/h on average. The elevation angle of the ball ranged from 11.7 to 15.3 degrees. In the final phase of the golf swing, i.e. downswing, the trunk rotators play the key role.

  8. Effects of special composite stretching on the swing of amateur golf players.

    Science.gov (United States)

    Lee, Joong-Chul; Lee, Sung-Wan; Yeo, Yun-Ghi; Park, Gi Duck

    2015-04-01

    [Purpose] The study investigated stretching for safer a golf swing compared to present stretching methods for proper swings in order to examine the effects of stretching exercises on golf swings. [Subjects] The subjects were 20 amateur golf club members who were divided into two groups: an experimental group which performed stretching, and a control group which did not. The subjects had no bone deformity, muscle weakness, muscle soreness, or neurological problems. [Methods] A swing analyzer and a ROM measuring instrument were used as the measuring tools. The swing analyzer was a GS400-golf hit ball analyzer (Korea) and the ROM measuring instrument was a goniometer (Korea). [Results] The experimental group showed a statistically significant improvement in driving distance. After the special stretching training for golf, a statistically significant difference in hit-ball direction deviation after swings were found between the groups. The experimental group showed statistically significant decreases in hit ball direction deviation. After the special stretching training for golf, statistically significant differences in hit-ball speed were found between the groups. The experimental group showed significant increases in hit-ball speed. [Conclusion] To examine the effects of a special stretching program for golf on golf swing-related factors, 20 male amateur golf club members performed a 12-week stretching training program. After the golf stretching training, statistically significant differences were found between the groups in hit-ball driving distance, direction deviation, deflection distance, and speed.

  9. Golf in the Wind: Exploring the Effect of Wind on the Accuracy of Golf Shots

    Science.gov (United States)

    Yaghoobian, Neda; Mittal, Rajat

    2015-11-01

    Golf play is highly dependent on the weather conditions with wind being the most significant factor in the unpredictability of the ball landing position. The direction and strength of the wind alters the aerodynamic forces on a ball in flight, and consequently its speed, distance and direction of travel. The fact that local wind conditions on any particular hole change over times-scales ranging all the way from a few seconds to minutes, hours and days introduces an element of variability in the ball trajectory that is not understood. Any such analysis is complicated by the effect of the local terrestrial and vegetation topology, as well as the inherent complexity of golf-ball aerodynamics. In the current study, we use computational modeling to examine the unpredictability of the shots under different wind conditions over Hole-12 at the Augusta National Golf Club, where the Masters Golf Tournament takes place every year. Despite this being the shortest hole on the course, the presence of complex vegetation canopy around this hole introduces a spatial and temporal variability in wind conditions that evokes uncertainty and even fear among professional golfers. We use our model to examine the effect of wind direction and wind-speed on the accuracy of the golf shots at this hole and use the simulations to determine the key aerodynamic factors that affect the accuracy of the shot.

  10. Akademi Golf di Surabaya

    OpenAIRE

    Santoso, Indra Purnama

    2013-01-01

    Golf adalah salah satu olahraga yang mulaipopular pada tahun-tahun ini. Popularitasnya makinmeningkat yang berdampak pada meningkatnya jumlahpemain golf padahal fasilitas yang mewadahinya sangatminim. Dalam Perancangan Akademi Golf di Surabaya,diharapkan dapat menambah fasilitas khususnya dalambidang pendidikan mengingat penggunanya mulaibanyak pada kaum muda. Fasilitas-fasilitas yangdirencanakan secara keseluruhan berhubungan denganpendidikan golf dimana juga mempertahankan kondisieksisting ...

  11. Golf club

    CERN Document Server

    Golf club

    2016-01-01

    The CERN Golf Club Members are herewith invited to the: Annual General Meeting Which takes place Wednesday evening the 10th February 2016 at 18 h 00 in the Conference room in building 13-2-005. A committee member will be at CERN gate B, 17 h 50 and accompany “external” CGC members to the conference room. Agenda: President’s report Treasurer’s report Election of the Committee for 2016 Election of  Auditors Draft schedule for 2016 CGC-competitions and other events “Corpo” report Report from lessons organized by CGC    Proposals and any other business Please forward any proposals (to any of the committee members) you have, including candidature for the 2016 committee minimum three days in advance before the meeting. Welcome !

  12. Commercial golf glove effects on golf performance and forearm muscle activity.

    Science.gov (United States)

    Sorbie, Graeme G; Darroch, Paul; Grace, Fergal M; Gu, Yaodong; Baker, Julien S; Ugbolue, Ukadike C

    2017-01-01

    The study aimed to determine whether or not commercial golf gloves influence performance variables and forearm muscle activity during golf play. Fifteen golfers participated in the laboratory based study, each performing 8 golf swings with a Driver and 7-iron whilst wearing a glove and 8 without wearing the glove. Club head speed, ball speed and absolute carry distance performance variables were calculated. Surface electromyography was recorded from the flexor digitorum superficialis and extensor carpi radialis brevis on both forearm muscles. Club head speed, ball speed and absolute carry distance was significantly higher when using the Driver with the glove in comparison to the Driver without the glove (p < 0.05). No significant differences were evident when using the 7-iron and no significant differences were displayed in muscle activity in either of the conditions. Findings from this study suggest that driving performance is improved when wearing a glove.

  13. Play Golf with the CERN Golf Club

    CERN Multimedia

    Golf Club

    2014-01-01

    The snow has gone, the grass is getting greener and the golf courses open up to hibernating golfers; The CERN golf club committee has been busy organising the program for the coming golf season, with many attractive outings to nearby courses. Are you new to CERN? And you play golf? or would like to learn ? then join us, playing golf and having fun. You can find all you need to know on our web-page; don’t hesitate to contact any of the committee members who will answer your questions.  Take a look at the provisional schedule below, sign-up and take part!  Besides these regular outings, as a CERN Golf Club member, you have also the opportunity to play in our “Corpo” team, in the competitions organised by the Golf Entreprise Rhone-Alpes. You can also play in our match play-tournament, and for new to the game, we organise some group–lessons with a local Pro. See:  http://club-golf.web.cern.ch/club-golf/index.php

  14. Golf Club

    CERN Multimedia

    Golf Club

    2012-01-01

      The CERN Golf Club Members are herewith invited to the Annual General Meeting which takes place Wednesday evening the 8th February at 18 h 00 in the Conference room in bldg 13-2-005. A committee member will be at CERN gate B, 17h50 and accompany “external” CGC members to the conference room. Agenda 1. President’s report 2. Treasurer’s report 3. Election of the Committee for 2012 4. Election of  Auditors 5. Draft schedule for 2012 CGC  competitions and other events 6. “Corpo” report     7. Proposals and any other business Please forward any proposals (to any of the committee members) you have, including candidature for the 2012 committee minimum three days in advance before the meeting. After the meeting we will book a table at the restaurant "Red Café", St-Genis. Please confirm to Alasdair Ross (Alasdair.Ross@cern.ch) if you would like to eat so th...

  15. Golf Club

    CERN Document Server

    Golf Club

    2013-01-01

    The CERN Golf Club Members are herewith invited to the: Annual General Meeting Which takes place Wednesday evening the 6th February 2013 at 18h00 in the Conference room in building 13-2-005. A committee member will be at CERN gate B, 17h50 and accompany “external” CGC members to the conference room. Agenda: President’s report Treasurer’s report Election of the Committee for 2013 Election of  Auditors Draft schedule for 2013 CGC-competitions and other events “Corpo” report     Proposals and any other business Please forward any proposals (to any of the committee members) you have, including candidature for the 2013 committee minimum three days in advance before the meeting. After the meeting we will book a table at the restaurant "Red Café", St. Genis. Please confirm to Alasdair Ross (Alasdair.Ross@cern.ch) if you would like to eat so that he can make the res...

  16. [Shoulder injuries in golf].

    Science.gov (United States)

    Liem, D; Gosheger, G; Schmidt, C

    2014-03-01

    Due to its growing popularity golf has now come into the focus of orthopedic sports medicine. With a wide range of age groups and playing levels, orthopedic surgeons will encounter a wide range of musculoskeletal problems which are usually the result of overuse rather than trauma. The shoulder joint plays an important role in the golf swing whereby not only the muscles around the glenohumeral joint but also the scapula stabilizing muscles are extremely important for an effective golf swing. Golf is strictly not considered to be an overhead sport; however, the extreme peak positions of the golf swing involve placing the shoulder joint in maximum abduction and adduction positions which can provoke impingement, lesions of the pulley system or even a special form of posterior shoulder instability. Even after complex shoulder operations, such as rotator cuff repair or shoulder arthroplasty, a return to the golf course at nearly the same level of play can be expected.

  17. Upper extremity golf injuries.

    Science.gov (United States)

    Cohn, Michael A; Lee, Steven K; Strauss, Eric J

    2013-01-01

    Golf is a global sport enjoyed by an estimated 60 million people around the world. Despite the common misconception that the risk of injury during the play of golf is minimal, golfers are subject to a myriad of potential pathologies. While the majority of injuries in golf are attributable to overuse, acute traumatic injuries can also occur. As the body's direct link to the golf club, the upper extremities are especially prone to injury. A thorough appreciation of the risk factors and patterns of injury will afford accurate diagnosis, treatment, and prevention of further injury.

  18. A big win for the CERN Golf Club at the ASCERI tournament

    CERN Multimedia

    Katarina Anthony

    2010-01-01

    The CERN Golf Club returned victorious from the autumn ASCERI (Association of the Sports Communities of the European Research Institutes) tournament which was held from 17 to 20 September.   The CERN Golf Team (left to right: Peter Jones, Alasdair Ross, Claes Frisk and Per Werner) celebrates its victories at ASCERI. Competitions took place on the Dreihof Golf Club at Essingen in southern Germany, starting with the singles Stableford competition on the first day and a 4 ball, better ball Stableford group competition the next day. CERN’s four-man team – Peter Jones, Per Werner, Claes Frisk and Alasdair Ross – came first in the group competition, with Peter Jones, CERN’s star golfer from the IT Department, winning the individual competition. The autumn ASCERI tournament included competitions in football, tennis and cart racing as well as golf. Over 230 representatives of research institutes across Europe took part. “The CERN Golf Club only began p...

  19. Playing Golf Is Elementary

    Science.gov (United States)

    Goldman, Jill S.; Pfluge, Kevin F.

    2010-01-01

    Golf is a lifelong activity that people of all ages can enjoy if they experience success and have fun. Early involvement in the sport facilitates the development of the ability to strike an object with an implement. Striking with implements can be challenging for young children and teachers, but golf can be taught in all elementary school settings…

  20. Golf-related injuries treated in United States emergency departments.

    Science.gov (United States)

    Walsh, Brittany A; Chounthirath, Thiphalak; Friedenberg, Laura; Smith, Gary A

    2017-11-01

    This study investigates unintentional non-fatal golf-related injuries in the US using a nationally representative database. This study analyzed golf-related injuries treated in US hospital emergency departments from 1990 through 2011 using the National Electronic Injury Surveillance System database. Injury rates were calculated using golf participation data. During 1990 through 2011, an estimated 663,471 (95% CI: 496,370-830,573) individuals ≥7years old were treated in US emergency departments for golf-related injuries, averaging 30,158 annually or 12.3 individuals per 10,000 golf participants. Patients 18-54years old accounted for 42.2% of injuries, but injury rates per 10,000 golf participants were highest among individuals 7-17years old (22.1) and ≥55years old (21.8) compared with 18-54years old (7.6). Patients ≥55years old had a hospital admission rate that was 5.01 (95% CI: 4.12-6.09) times higher than that of younger patients. Injured by a golf club (23.4%) or struck by a golf ball (16.0%) were the most common specified mechanisms of injury. The head/neck was the most frequently injured body region (36.2%), and sprain/strain (30.6%) was the most common type of injury. Most patients were treated and released (93.7%) and 5.9% required hospitalization. Although golf is a source of injury among all age groups, the frequency and rate of injury were higher at the two ends of the age spectrum. Given the higher injury and hospital admission rates of patients ≥55years, this age group merits the special attention of additional research and injury prevention efforts. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. A Scoping Review of the Associations of Golf with Eye Injuries in Adults and Children

    Science.gov (United States)

    2016-01-01

    Introduction. Sport presents a risk of ocular trauma and accounts for a significant number of eye injuries that require hospital admission. The sport of golf presents a risk to eyesight from fast moving objects such as golf clubs and balls. This study aims to investigate the associations of golf with eye injuries and the reasons that these injuries occur. Material/Methods. A literature search was conducted using the databases MEDLINE, Web of Science, SPORTDiscus, and PsycINFO. Grey literature was searched using the WHO international clinical trials registry platform, Google Scholar, and ProQuest. Data was extracted using a standardised form and summarised into a report. Results and Discussion. Twenty-three studies were found relating to eye injuries in golf. Injuries appear to be rare, but more frequent in men and children. Injuries resulted in high rates of enucleation and visual impairment. Children sustained more injury from golf clubs whereas adults sustained more injuries from golf balls. Conclusion. Efforts are needed to encourage golf participants to understand the risks of ocular and indeed other head injuries. Initiatives to provide appropriate supervision and education on this topic are merited. Further research is needed to investigate the circumstances of eye injury in golf and assess the effects of interventions aimed at reducing risk of injury. PMID:27504485

  2. Physicochemical properties of direct compression tablets with spray dried and ball milled solid dispersions of tadalafil in PVP-VA.

    Science.gov (United States)

    Wlodarski, K; Tajber, L; Sawicki, W

    2016-12-01

    The aim of this research was to develop immediate release tablets comprising solid dispersion (IRSDTs) of tadalafil (Td) in a vinylpyrrolidone and vinyl acetate block copolymer (PVP-VA), characterized by improved dissolution profiles. The solid dispersion of Td in PVP-VA (Td/PVP-VA) in a weight ratio of 1:1 (w/w) was prepared using two different processes i.e. spray drying and ball milling. While the former process has been well established in the formulation of IRSDTs the latter has not been exploited in these systems yet. Regardless of the preparation method, both Td/PVP-VA solid dispersions were amorphous as confirmed by PXRD, DSC and FTIR. However, different morphology of particles (SEM) resulted in differences in water apparent solubility and disk intrinsic dissolution rate (DIDR). Both solid dispersions and crystalline Td were successfully made into directly compressible tablets at three doses of Td, i.e. 2.5mg, 10mgand20mg, yielding nine different formulations (D 1 -D 9 ). Each of the lots met the requirements set by Ph.Eur. and was evaluated with respect to appearance, diameter, thickness, mass, hardness, friability, disintegration time and content of Td. IRSDTs performed as supersaturable formulations and had significantly improved water dissolution profiles in comparison with equivalent tablets containing crystalline Td and the marketed formulations. Tablets with both spray dried and ball milled Td/PVP-VA revealed the greatest improvement in dissolution depending on the investigated doses, i.e. 2.5mgand20mg, respectively. Also, dissolution of Td from Td/PVP-VA delivered in different forms occurred in the following order: powders>tablets>capsules. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. Golf and upper limb injuries: a summary and review of the literature

    Directory of Open Access Journals (Sweden)

    Pollard Henry P

    2005-05-01

    Full Text Available Abstract Background Golf is a popular past time that provides exercise with social interaction. However, as with all sports and activities, injury may occur. Many golf-related injuries occur in the upper limb, yet little research on the potential mechanisms of these injuries has been conducted. Objective To review the current literature on golf-related upper limb injuries and report on potential causes of injury as it relates to the golf swing. Discussion An overview of the golf swing is described in terms of its potential to cause the frequently noted injuries. Most injuries occur at impact when the golf club hits the ball. This paper concludes that more research into golf-related upper limb injuries is required to develop a thorough understanding of how injuries occur. Types of research include epidemiology studies, kinematic swing analysis and electromyographic studies of the upper limb during golf. By conducting such research, preventative measures maybe developed to reduce golf related injury.

  4. The spinning ball spiral

    International Nuclear Information System (INIS)

    Dupeux, Guillaume; Le Goff, Anne; Quere, David; Clanet, Christophe

    2010-01-01

    We discuss the trajectory of a fast revolving solid ball moving in a fluid of comparable density. As the ball slows down owing to drag, its trajectory follows an exponential spiral as long as the rotation speed remains constant: at the characteristic distance L where the ball speed is significantly affected by the drag, the bending of the trajectory increases, surprisingly. Later, the rotation speed decreases, which makes the ball follow a second kind of spiral, also described in the paper. Finally, the use of these highly curved trajectories is shown to be relevant to sports.

  5. Ball clay

    Science.gov (United States)

    Virta, R.L.

    2001-01-01

    Part of the 2000 annual review of the industrial minerals sector. A general overview of the ball clay industry is provided. In 2000, sales of ball clay reached record levels, with sanitary ware and tile applications accounting for the largest sales. Ball clay production, consumption, prices, foreign trade, and industry news are summarized. The outlook for the ball clay industry is also outlined.

  6. Marketing of cocrete golf course

    OpenAIRE

    Krausová, Lenka

    2011-01-01

    This thesis deals with the marketing of golf services. The main goal is to propose a marketing strategy for concrete golf course. Prior to its implementation were needed to work out individual analysis - SWOT analysis, competitor analysis and survey of customer satisfaction. Furthermore, the identified individual operating costs and revenues of golf course. When creating marketing strategy was put stress on the Internet. It proposes a new form and structure of the website, Facebook profile an...

  7. Cern Golf Club

    CERN Document Server

    Cern Golf Club

    2014-01-01

      The Cern Golf Club   Members are here with invited to the: Annual General Meeting which takes place Wednesday evening the 5th February 2014 at 18h00 in the Conference room in bldg 13-2-005. A committee member will be at CERN gate B, 17h50 and accompany “external” CGC members to the conference room. Agenda: 1. President’s report 2. Treasurer’s report 3. Election of the Committee for 2014 4. Election of  Auditors 5. Draft schedule for 2014 CGC-competitions and other events 6. “Corpo” report    7. Proposals and any other business Please forward any proposals (to any of the committee members) you have, including candidature for the 2014 committee minimum three days in advance before the meeting.      Cern Golf Club   Les membres de club de golf de CERN sont invités à l’Assemblée Géné...

  8. Cost management of golf courses

    OpenAIRE

    Černický, Marek

    2010-01-01

    The thesis focuses on costs incurred during the golf course construction and also on operating costs. Types of these costs and options of cost cutting are described. The final part of the thesis analyzes and models usage yield and capacity of golf courses.

  9. Golf: A Game of Inclusion

    Science.gov (United States)

    Dempsey, Dana

    2009-01-01

    Golf has become a popular sport for kids throughout the world; however, many do not realize that it is also a sport that offers benefits to children with physical challenges. Golf can be used for recreational purposes and as a motivational tool for rehabilitation. These two principles serve as the foundation upon which Texas Scottish Rite Hospital…

  10. The Sequence of Hip and Selected Upper-Extremity Joint Movements During the Golf Drive.

    Science.gov (United States)

    Hunter, Charles L.

    This study analyzed wrist, elbow, and hip actions of golfers who were accurately driving a golf ball a maximum distance. Electrogoniometry and cinematography were used to measure wrist, forearm, elbow, and hip actions during the downswing of 10 low-handicap golfers who were attempting to drive a minimum of 225 yards within a 50-yard corridor.…

  11. Correlation of Titleist Performance Institute (TPI) level 1 movement screens and golf swing faults.

    Science.gov (United States)

    Gulgin, Heather R; Schulte, Brian C; Crawley, Amy A

    2014-02-01

    Although some research in the past has examined how physical limitations in strength or flexibility affect a golfer's performance, the performance outcome most measured was driving distance. Currently, there are no data that have examined the relationship between selected strength and flexibility variables and golf swing faults. The purpose of this study was to examine the relationship between Titleist Performance Institute (TPI) level 1 movement screen variables and 14 common golf swing faults. Thirty-six male and female golfers (mean age, 25.4 ± 9.9 years; height, 175.9 ± 16.2 cm; mass, 76.2 ± 14.6 kg; handicap, 14.2 ± 10.4) participated. Twelve physical tests of strength, flexibility, and balance were assessed using the TPI level 1 golf fitness screening tool. Golfers then hit 4 golf shots (with a 5-iron) while being videoed, and those were then analyzed for 14 different golf swing faults (using V1Pro software). Three significant associations between a physical limitation and a particular golf swing fault were found: toe touch and early hip extension (p = 0.015), bridge on right side with both early hip extension (p = 0.050), and loss of posture (p = 0.028). In addition, an odds ratio showed that when a golfer could not overhead deep squat or single leg balance on left side, they were 2-3 times more likely to exhibit a early hip extension, loss of posture, or slide during the golf swing, as compared with those who could perform a correct overhead deep squat. Based on our findings, it is important for the golf fitness professional to particularly address a golfer's core strength, balance, and hamstring flexibility to help avoid common golf swing faults, which affect a golfer's ball striking ability and ultimately their performance.

  12. Difference in peak weight transfer and timing based on golf handicap.

    Science.gov (United States)

    Queen, Robin M; Butler, Robert J; Dai, Boyi; Barnes, C Lowry

    2013-09-01

    Weight shift during the golf swing has been a topic of discussion among golf professionals; however, it is still unclear how weight shift varies in golfers of different performance levels. The main purpose of this study was to examine the following: (a) the changes in the peak ground reaction forces (GRF) and the timing of these events between high (HHCP) and low handicap (LHCP) golfers and (b) the differences between the leading and trailing legs. Twenty-eight male golfers were recruited and divided based on having an LHCP 9. Three-dimensional GRF peaks and the timing of the peaks were recorded bilaterally during a golf swing. The golf swing was divided into different phases: (a) address to the top of the backswing, (b) top of the backswing to ball contact, and (c) ball contact to the end of follow through. Repeated measures analyses of variance (α = 0.05) were completed for each study variable: the magnitude and the timing of peak vertical GRF, peak lateral GRF, and peak medial GRF (α = 0.05). The LHCP group had a greater transfer of vertical force from the trailing foot to the leading foot in phase 2 than the HHCP group. The LHCP group also demonstrated earlier timing of peak vertical force throughout the golf swing than the HHCP group. The LHCP and HHCP groups demonstrated different magnitudes of peak lateral force. The LHCP group had an earlier timing of peak lateral GRF in phase 2 and earlier timing of peak medial GRF in phases 1 and 2 than the HHCP group. In general, LHCP golfers demonstrated greater and earlier force generation than HHCP golfers. It may be relevant to consider both the magnitude of the forces and the timing of these events during golf-specific training to improve performance. These data reveal weight shifting differences that can be addressed by teaching professionals to help their students better understand weight transfer during the golf swing to optimize performance.

  13. The Biomechanics of the Modern Golf Swing: Implications for Lower Back Injuries.

    Science.gov (United States)

    Cole, Michael H; Grimshaw, Paul N

    2016-03-01

    The modern golf swing is a complex and asymmetrical movement that places an emphasis on restricting pelvic turn while increasing thorax rotation during the backswing to generate higher clubhead speeds at impact. Increasing thorax rotation relative to pelvic rotation preloads the trunk muscles by accentuating their length and allowing them to use the energy stored in their elastic elements to produce more power. As the thorax and pelvis turn back towards the ball during the downswing, more skilled golfers are known to laterally slide their pelvis toward the target, which further contributes to final clubhead speed. However, despite the apparent performance benefits associated with these sequences, it has been argued that the lumbar spine is incapable of safely accommodating the forces they produce. This notion supports a link between the repeated performance of the golf swing and the development of golf-related low back injuries. Of the complaints reported by golfers, low back injuries continue to be the most prevalent, but the mechanism of these injuries is still poorly understood. This review highlights that there is a paucity of research directly evaluating the apparent link between the modern golf swing and golf-related low back pain. Furthermore, there has been a general lack of consensus within the literature with respect to the methods used to objectively assess the golf swing and the methods used to derived common outcome measures. Future research would benefit from a clear set of guidelines to help reduce the variability between studies.

  14. Where do golf driver swings go wrong? Factors influencing driver swing consistency.

    Science.gov (United States)

    Zhang, X; Shan, G

    2014-10-01

    One of the challenging skills in golfing is the driver swing. There have been a large number of studies characterizing golf swings, yielding insightful instructions on how to swing well. As a result, achieving a sub-18 handicap is no longer the top problem for golfers. Instead, players are now most troubled by a lack of consistency during swing execution. The goal of this study was to determine how to consistently execute good golf swings. Using 3D motion capture and full-body biomechanical modeling, 22 experienced golfers were analysed. For characterizing both successful and failed swings, 19 selected parameters (13 angles, 4 time parameters, and 2 distances) were used. The results showed that 14 parameters are highly sensitive and/or prone to motor control variations. These parameters sensitized five distinct areas of swing to variation: (a) ball positioning, (b) transverse club angle, (c) transition, (d) wrist control, and (e) posture migration between takeaway and impact. Suggestions were provided for how to address these five distinct problem areas. We hope our findings on how to achieve consistency in golf swings will benefit all levels of golf pedagogy and help maintain/develop interests to involve more golf/physical activity for a healthy lifestyle. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  15. Orbital fracture and eyeball rupture caused by golf-club injury.

    Science.gov (United States)

    Hwang, Kun; Kim, Joo Ho

    2014-05-01

    We report a case of an orbital fracture and an eyeball rupture caused by a golf-club injury. A 75-year-old man was struck in his right eye by a golf club while watching behind his son swinging a hybrid-type golf club at his home. A 70-mm muscle-depth laceration was present in the infraorbital area with active bleeding. Computed tomographic imaging of the face revealed a rupture of the right eyeball; fractures in the superior, medial, lateral, and inferior wall of the right orbit; a fracture in the right zygomaticofrontal junction; and a small amount of pneumocephalus in the parafalx region. Under general anesthesia, evisceration of the right eyeball was performed. Not only golfers but also people just watching or passing by can be injured by an errantly struck golf ball or swung golf club. Elderly people as well as children should be instructed in technique and safety and also be supervised when playing golf. Also, the public should be educated about the risk of eye injuries and the benefits of wearing a protective eyewear.

  16. Lignocellulose fermentation and residual solids characterization for senescent switchgrass fermentation by Clostridium thermocellum in the presence and absence of continuous in situ ball-milling

    Energy Technology Data Exchange (ETDEWEB)

    Balch, Michael L.; Holwerda, Evert K.; Davis, Mark F.; Sykes, Robert W.; Happs, Renee M.; Kumar, Rajeev; Wyman, Charles E.; Lynd, Lee R.

    2017-04-12

    Milling during lignocellulosic fermentation, henceforth referred to as cotreatment, is investigated as an alternative to thermochemical pretreatment as a means of enhancing biological solubilization of lignocellulose. We investigate the impact of milling on soluble substrate fermentation by Clostridium thermocellum with comparison to yeast, document solubilization for fermentation of senescent switchgrass with and without ball milling, and characterize residual solids. Soluble substrate fermentation by C. thermocellum proceeded readily in the presence of continuous ball milling but was completely arrested for yeast. Total fractional carbohydrate solubilization achieved after fermentation of senescent switchgrass by C. thermocellum for 5 days was 0.45 without cotreatment or pretreatment, 0.81 with hydrothermal pretreatment (200 degrees C, 15 minutes, severity 4.2), and 0.88 with cotreatment. Acetate and ethanol were the main fermentation products, and were produced at similar ratios with and without cotreatment. Analysis of solid residues was undertaken using molecular beam mass spectrometry (PyMBMS) and solid-state nuclear magnetic resonance spectroscopy (NMR) in order to provide insight into changes in plant cell walls during processing via various modes. The structure of lignin present in residual solids remaining after fermentation with cotreatment appeared to change little, with substantially greater changes observed for hydrothermal pretreatment - particularly with respect to formation of C-C bonds. The observation of high solubilization with little apparent modification of the residue is consistent with cotreatment enhancing solubilization primarily by increasing the access of saccharolytic enzymes to the feedstock, and C. thermocellum being able to attack all the major linkages in cellulosic biomass provided that these linkages are accessible.

  17. The green game: investigating golf management practices

    Directory of Open Access Journals (Sweden)

    Bianca de Klerk

    2014-01-01

    Full Text Available Worldwide, golf is the largest sports-related travel market segment showing tremendous economic growth. Unfortunately, tourism and the so-called ‘green game’ contribute to environmental damage. Golf tourism is a rapidly expanding special interest activity linked to tourism. With a degraded physical environment, a destination may be in danger of losing its original appeal, which may force ‘naturebased’ tourists to move on to other destinations. The private sector, governments and the environment will benefit from responsible and sustainable practices including the management of golf courses. This will ensure that destinations continue to attract tourists for future generations. Therefore, green golf tourism is the only logical option placing the responsibility on golf course management to take a second look at the nature of this game. The study focused on the effects that golf course management might have on the environment and the adaptation methods implemented to reduce environmental damage. The management of George Golf Club and Pinnacle Point, located along the Garden Route, one of South Africa’s prime attractions were included in the study. Results indicated that management did not specifically monitor the impact of the golf course on the environment and did not educate golf tourists about environmental friendly practices on golf courses. Little was also done to motivate golf tourists to demand environmental friendly golf courses.

  18. Distance and slope constraints: adaptation and variability in golf putting.

    Science.gov (United States)

    Dias, Gonçalo; Couceiro, Micael S; Barreiros, João; Clemente, Filipe M; Mendes, Rui; Martins, Fernando M

    2014-07-01

    The main objective of this study is to understand the adaptation to external constraints and the effects of variability in a golf putting task. We describe the adaptation of relevant variables of golf putting to the distance to the hole and to the addition of a slope. The sample consisted of 10 adult male (33.80 ± 11.89 years), volunteers, right handed and highly skilled golfers with an average handicap of 10.82. Each player performed 30 putts at distances of 2, 3 and 4 meters (90 trials in Condition 1). The participants also performed 90 trials, at the same distances, with a constraint imposed by a slope (Condition 2). The results indicate that the players change some parameters to adjust to the task constraints, namely the duration of the backswing phase, the speed of the club head and the acceleration at the moment of impact with the ball. The effects of different golf putting distances in the no-slope condition on different kinematic variables suggest a linear adjustment to distance variation that was not observed when in the slope condition.

  19. Analysis of Golf Swing Motion and Applied Loads on the Human Body Using Soft-Golf TM Club

    International Nuclear Information System (INIS)

    Kwak, Ki Young; So, Ha Ju; Kim, Sung Hyeon; Kim, Dong Wook; Kim, Nam Gyun

    2011-01-01

    The purpose of this study was to analyze the kinetic effect of Soft-golf TM instrument on the human body structure. To analyze the kinetic effect of Soft-golf TM instrument, Golf swing using Soft-golf TM instrument and regular golf instrument was captured. And then Upper limbs and lumbar joint torques was calculated via computer simulation. Five man participated this study. Subjects performed golf swing using a regular golf and Soft-golf TM instrument. Golf swing motion was captured using three position sensor, active infrared LED maker and force plate. Golf swing model was generated and simulated using ADAMS/LifeMOD program. As a results, joint torque during Soft-golf swing were lower than regular golf swing. Thus soft-golf swing have joint load lower than regular golf swing and contribute to reduce joint injury

  20. LUMBAR CORSETS CAN DECREASE LUMBAR MOTION IN GOLF SWING

    Directory of Open Access Journals (Sweden)

    Koji Hashimoto

    2013-03-01

    Full Text Available Swinging a golf club includes the rotation and extension of the lumbar spine. Golf-related low back pain has been associated with degeneration of the lumbar facet and intervertebral discs, and with spondylolysis. Reflective markers were placed directly onto the skin of 11young male amateur golfers without a previous history of back pain. Using a VICON system (Oxford Metrics, U.K., full golf swings were monitored without a corset (WOC, with a soft corset (SC, and with a hard corset (HC, with each subject taking 3 swings. Changes in the angle between the pelvis and the thorax (maximum range of motion and angular velocity in 3 dimensions (lumbar rotation, flexion-extension, and lateral tilt were analyzed, as was rotation of the hip joint. Peak changes in lumbar extension and rotation occurred just after impact with the ball. The extension angle of the lumbar spine at finish was significantly lower under SC (38° or HC (28° than under WOC (44° conditions (p < 0.05. The maximum angular velocity after impact was significantly smaller under HC (94°/sec than under SC (177°/sec and WOC (191° /sec conditions, as were the lumbar rotation angles at top and finish. In contrast, right hip rotation angles at top showed a compensatory increase under HC conditions. Wearing a lumbar corset while swinging a golf club can effectively decrease lumbar extension and rotation angles from impact until the end of the swing. These effects were significantly enhanced while wearing an HC

  1. Experience mapping and multifunctional golf course development

    DEFF Research Database (Denmark)

    Caspersen, Ole H.; Jensen, Frank Søndergaard; Jensen, Anne Mette Dahl

    This report describes the development of a method for mapping and describing recreational experiences on golf courses. The objective is to provide a planning tool that can facilitate development of a broader multifunctional use of the golf course landscape. The project has produced several results....... The main output is this report, which provides a detailed description of the mapping procedure. This process is illustrated using examples from five test golf courses. In addition to this mapping report, a catalogue has been developed providing hands-on guidance for adapting the method in a golf club...... without the use of a specialist. During the project period, the research team has participated in a number of workshops that included representatives from golf courses, STERF, the Norwegian Golf Federation and the Danish Golf Union. At these workshops, the method was presented and discussed. This has been...

  2. Relationships between field-based measures of strength and power and golf club head speed.

    Science.gov (United States)

    Read, Paul J; Lloyd, Rhodri S; De Ste Croix, Mark; Oliver, Jon L

    2013-10-01

    Increased golf club head speed (CHS) has been shown to result in greater driving distances and is also correlated with golf handicap. The purpose of this study was to investigate the relationships between field-based measures of strength and power and golf CHS with a secondary aim to determine the reliability of the selected tests. A correlation design was used to assess the following variables: anthropometrics, squat jump (SJ) height and squat jump peak power (SJPP), unilateral countermovement jump (CMJ) heights (right leg countermovement jump and left leg countermovement jump [LLCMJ]), bilateral CMJ heights, countermovement jump peak power (CMJPP), and medicine ball seated throw (MBST) and medicine ball rotational throw (MBRT). Fouty-eight male subjects participated in the study (age: 20.1 ± 3.2 years, height: 1.76 ± 0.07 m, mass: 72.8 ± 7.8 kg, handicap: 5.8 ± 2.2). Moderate significant correlations were reported between CHS and MBRT (r = 0.67; p golf athletes using the proposed battery of field tests. Additionally, movements that are more concentrically dominant in nature may display stronger relationships with CHS due to MBST and SJ displaying the highest explained variance after a stepwise linear regression.

  3. Launch Velocities in Successful Golf Putting: An Analytical Analysis

    Directory of Open Access Journals (Sweden)

    John F. Mahoney

    2017-04-01

    Full Text Available Background: This study is concerned with the special case of a putted ball intersecting a standard golf hole at its diameter. The velocity of the ball at the initial rim of the hole is termed the launch velocity and depending upon its value the ball may either be captured or it may escape capture by jumping over the hole. The critical value of the launch velocity (V is such that lesser values result in capture while greater values produce escape. Purpose: Since the value of the V entered prominently in some theoretical studies of putting, the aim of the current study is to provide an original re-evaluation of V and to contrast our results with existing results. Method: This analytical analysis relies on trigonometry in conjunction with Newtonian mechanics and the mathematics of projectiles. The results of a recent study into the mathematics of a bouncing ball which included the notions of restitution and friction were also employed in the analysis. Results: If bouncing and slipping do not occur when the ball hits the far rim of the hole our analysis produces a value of V of 1.356 m/s. When bouncing and slipping are present we find that V is at least 1.609 m/s but increases beyond this value as slipping and friction become greater. Useful relations which relate the dynamics and geometry of the ball to V are provided. Conclusion: Since ambient conditions may influence the extent of bounce and slippage we conjecture that the value of V is not unique.

  4. Golf Injuries to the Hand, Wrist, or Elbow

    Science.gov (United States)

    ... Therapist? Media Find a Hand Surgeon Home Anatomy Golf Injuries to the Hand, Wrist or Elbow Email ... enjoyment of the game injury free. Types of Golf Injuries Golf injuries can include tendonitis, sprains or ...

  5. Real-ear acoustical characteristics of impulse sound generated by golf drivers and the estimated risk to hearing: a cross-sectional study.

    Science.gov (United States)

    Zhao, Fei; Bardsley, Barry

    2014-01-21

    This study investigated real-ear acoustical characteristics in terms of the sound pressure levels (SPLs) and frequency responses in situ generated from golf club drivers at impact with a golf ball. The risk of hearing loss caused by hitting a basket of golf balls using various drivers was then estimated. Cross-sectional study. The three driver clubs were chosen on the basis of reflection of the commonality and modern technology of the clubs. The participants were asked to choose the clubs in a random order and hit six two-piece range golf balls with each club. The experiment was carried out at a golf driving range in South Wales, UK. 19 male amateur golfers volunteered to take part in the study, with an age range of 19-54 years. The frequency responses and peak SPLs in situ of the transient sound generated from the club at impact were recorded bilaterally and simultaneously using the GN Otometric Freefit wireless real-ear measurement system. A swing speed radar system was also used to investigate the relationship between noise level and swing speed. Different clubs generated significantly different real-ear acoustical characteristics in terms of SPL and frequency responses. However, they did not differ significantly between the ears. No significant correlation was found between the swing speed and noise intensity. On the basis of the SPLs measured in the present study, the percentage of daily noise exposure for hitting a basket of golf balls using the drivers described above was less than 2%. The immediate danger of noise-induced hearing loss for amateur golfers is quite unlikely. However, it may be dangerous to hearing if the noise level generated by the golf clubs exceeded 116 dBA.

  6. The role of biomechanics in maximising distance and accuracy of golf shots.

    Science.gov (United States)

    Hume, Patria A; Keogh, Justin; Reid, Duncan

    2005-01-01

    Golf biomechanics applies the principles and technique of mechanics to the structure and function of the golfer in an effort to improve golf technique and performance. A common recommendation for technical correction is maintaining a single fixed centre hub of rotation with a two-lever one-hinge moment arm to impart force on the ball. The primary and secondary spinal angles are important for conservation of angular momentum using the kinetic link principle to generate high club-head velocity. When the golfer wants to maximise the distance of their drives, relatively large ground reaction forces (GRF) need to be produced. However, during the backswing, a greater proportion of the GRF will be observed on the back foot, with transfer of the GRF on to the front foot during the downswing/acceleration phase. Rapidly stretching hip, trunk and upper limb muscles during the backswing, maximising the X-factor early in the downswing, and uncocking the wrists when the lead arm is about 30 degrees below the horizontal will take advantage of the summation of force principle. This will help generate large angular velocity of the club head, and ultimately ball displacement. Physical conditioning will help to recruit the muscles in the correct sequence and to optimum effect. To maximise the accuracy of chipping and putting shots, the golfer should produce a lower grip on the club and a slower/shorter backswing. Consistent patterns of shoulder and wrist movements and temporal patterning result in successful chip shots. Qualitative and quantitative methods are used to biomechanically assess golf techniques. Two- and three-dimensional videography, force plate analysis and electromyography techniques have been employed. The common golf biomechanics principles necessary to understand golf technique are stability, Newton's laws of motion (inertia, acceleration, action reaction), lever arms, conservation of angular momentum, projectiles, the kinetic link principle and the stretch

  7. Russian Golf Profile with the Perspective of Golf Tourism in South East Asia

    OpenAIRE

    Nikiforova, Tatiana

    2010-01-01

    The aim of the study was to formulate Russian golf profile and evaluate it from the perspective of golf tourism in South East Asian countries concentrating on five countries: Indonesia, Malaysia, Thailand, the Philippines and Singapore. The research discovered and analyzed the factors that accelerate and prevent Russian golf players from traveling to South East Asia region with golf and tourism purposes. In the theoretical part of the study the main issue was to describe the current situation...

  8. Methodological considerations for the 3D measurement of the X-factor and lower trunk movement in golf.

    Science.gov (United States)

    Joyce, Christopher; Burnett, Angus; Ball, Kevin

    2010-09-01

    It is believed that increasing the X-factor (movement of the shoulders relative to the hips) during the golf swing can increase ball velocity at impact. Increasing the X-factor may also increase the risk of low back pain. The aim of this study was to provide recommendations for the three-dimensional (3D) measurement of the X-factor and lower trunk movement during the golf swing. This three-part validation study involved; (1) developing and validating models and related algorithms (2) comparing 3D data obtained during static positions representative of the golf swing to visual estimates and (3) comparing 3D data obtained during dynamic golf swings to images gained from high-speed video. Of particular interest were issues related to sequence dependency. After models and algorithms were validated, results from parts two and three of the study supported the conclusion that a lateral bending/flexion-extension/axial rotation (ZYX) order of rotation was deemed to be the most suitable Cardanic sequence to use in the assessment of the X-factor and lower trunk movement in the golf swing. The findings of this study have relevance for further research examining the X-factor its relationship to club head speed and lower trunk movement and low back pain in golf.

  9. Advances in Solid-State Transformations of Coordination Bonds: From the Ball Mill to the Aging Chamber

    Directory of Open Access Journals (Sweden)

    Cristina Mottillo

    2017-01-01

    Full Text Available Controlling the formation of coordination bonds is pivotal to the development of a plethora of functional metal-organic materials, ranging from coordination polymers, metal-organic frameworks (MOFs to metallodrugs. The interest in and commercialization of such materials has created a need for more efficient, environmentally-friendly routes for making coordination bonds. Solid-state coordination chemistry is a versatile greener alternative to conventional synthesis, offering quantitative yields, enhanced stoichiometric and topological selectivity, access to a wider range of precursors, as well as to molecules and materials not readily accessible in solution or solvothermally. With a focus on mechanochemical, thermochemical and “accelerated aging” approaches to coordination polymers, including pharmaceutically-relevant materials and microporous MOFs, this review highlights the recent advances in solid-state coordination chemistry and techniques for understanding the underlying reaction mechanisms.

  10. CFD Study of Drag and Lift of Sepak Takraw Ball at Different Face Orientations

    Directory of Open Access Journals (Sweden)

    Abdul Syakir Abdul Mubin

    2015-01-01

    Full Text Available There have been a significant number of researches on computational fluid dynamic (CFD analysis of balls used in sports such as golf balls, tennis balls, and soccer balls. Sepak takraw is a high speed court game predominantly played in Southeast Asia using mainly the legs and head. The sepak takraw ball is unique because it is not enclosed and made of woven plastic. Hence a study of its aerodynamicswould give insight into its behaviour under different conditions of play. In this study the dynamics of the fluid around a static sepak takraw ball was investigated at different wind speeds for three different orientations using CFD. It was found that although the drag did not differ very much, increasing the wind velocity causes an increase in drag. The lift coefficientvaries as the velocity increases and does not show a regular pattern. The drag and lift coefficients are influenced by the orientation of the sepak takraw ball.

  11. Learning Technology and Engineering Principles through Golf

    Science.gov (United States)

    Yoshikawa, Emily; Bartholomew, Scott R.

    2018-01-01

    While the physical exercise of playing golf and the sheer enjoyment of the sport are both positive benefits, there are subtler opportunities for golf to be used in conjunction with other ideas for learning in K-12 education; the mechanics and details behind the sport, as well as the variety of clubs, courses, and swings are all potential…

  12. Return to golf after spine surgery.

    Science.gov (United States)

    Abla, Adib A; Maroon, Joseph C; Lochhead, Richard; Sonntag, Volker K H; Maroon, Adara; Field, Melvin

    2011-01-01

    no published evidence indicates when patients can resume golfing after spine surgery. The objective of this study is to provide data from surveys sent to spine surgeons. a survey of North American Spine Society members was undertaken querying the suggested timing of return to golf. Of 1000 spine surgeons surveyed, 523 responded (52.3%). The timing of recommended return to golf and the reasons were questioned for college/professional athletes and avid and recreational golfers of both sexes. Responses were tallied for lumbar laminectomy, lumbar microdiscectomy, lumbar fusion, and anterior cervical discectomy with fusion. the most common recommended time for return to golf was 4-8 weeks after lumbar laminectomy and lumbar microdiscectomy, 2-3 months after anterior cervical fusion, and 6 months after lumbar fusion. The results showed a statistically significant increase in the recommended time to resume golf after lumbar fusion than after cervical fusion in all patients (p golf after spine surgery depends on many variables, including the general well-being of patients in terms of pain control and comfort when golfing. This survey serves as a guide that can assist medical practitioners in telling patients the average times recommended by surgeons across North America regarding return to golf after spine surgery.

  13. A synoptic view of golf course management

    Science.gov (United States)

    Katula, Robert L.

    1996-03-01

    The maintenance, construction, and redesign of private, public, and municipal golf courses in the United States is a multi-billion dollar industry. The entire golf course maintenance market, according to the National Golf Foundation, was 6.2 billion per year in 1991. The average maintenance cost in the United States was approximately 40,000 per hole per year for the over 15,000 golf courses in the United States in 1991. Golf course maintenance costs have risen 500 percent from 1971 to 1991. These costs are projected to continue to increase at a rate of 8 percent per year due to the demand for quality playing surfaces, increased use of non-potable water, and taxes on water and chemicals required to maintain turfgrass. The golf course construction and redesign market continues to maintain a rate of over 300 new golf courses and redesigned courses completed each year. The average construction costs run from 4 to 6 million and the average redesign costs 2 to 3 million per course. In order to create a perfectly maintained golf course, golf course managers may use as many as 25 different pesticides, fertilizers, and herbicides to control insects and turf disease. Further, turfgrass is often stressed to its limits when kept at the unnatural heights required to obtain firm and fast greens and fairways. The daily practice of living on the edge is often done with limited knowledge of changes taking place on the golf course, of the location of soil types and fertility, of surface and subsurface drainage, and of previous maintenance practices. There is a growing concern in the golf course industry that the concentration of chemicals and water required to maintain today's golf course may endanger ground water supplies for the surrounding ecosystem. This paper will describe the general methodology PTS used to develop a new management system for the maintenance, construction, and redesign of golf courses. The management system integrates remote sensing technology, geographic

  14. Three-dimensional trunk kinematics in golf: between-club differences and relationships to clubhead speed.

    Science.gov (United States)

    Joyce, Christopher; Burnett, Angus; Cochrane, Jodie; Ball, Kevin

    2013-06-01

    The aims of this study were (i) to determine whether significant three-dimensional (3D) trunk kinematic differences existed between a driver and a five-iron during a golf swing; and (ii) to determine the anthropometric, physiological, and trunk kinematic variables associated with clubhead speed. Trunk range of motion and golf swing kinematic data were collected from 15 low-handicap male golfers (handicap = 2.5 +/- 1.9). Data were collected using a 10-camera motion capture system operating at 250 Hz. Data on clubhead speed and ball velocity were collected using a real-time launch monitor. Paired t-tests revealed nine significant (p golf swing kinematics, namely trunk and lower trunk flexion/extension and lower trunk axial rotation. Multiple regression analyses explained 33.7-66.7% of the variance in clubhead speed for the driver and five-iron, respectively, with both trunk and lower trunk variables showing associations with clubhead speed. Future studies should consider the role of the upper limbs and modifiable features of the golf club in developing clubhead speed for the driver in particular.

  15. Effects of physical randomness training on virtual and laboratory golf putting performance in novices.

    Science.gov (United States)

    Pataky, T C; Lamb, P F

    2018-06-01

    External randomness exists in all sports but is perhaps most obvious in golf putting where robotic putters sink only 80% of 5 m putts due to unpredictable ball-green dynamics. The purpose of this study was to test whether physical randomness training can improve putting performance in novices. A virtual random-physics golf-putting game was developed based on controlled ball-roll data. Thirty-two subjects were assigned a unique randomness gain (RG) ranging from 0.1 to 2.0-times real-world randomness. Putter face kinematics were measured in 5 m laboratory putts before and after five days of virtual training. Performance was quantified using putt success rate and "miss-adjustment correlation" (MAC), the correlation between left-right miss magnitude and subsequent right-left kinematic adjustments. Results showed no RG-success correlation (r = -0.066, p = 0.719) but mildly stronger correlations with MAC for face angle (r = -0.168, p = 0.358) and clubhead path (r = -0.302, p = 0.093). The strongest RG-MAC correlation was observed during virtual training (r = -0.692, p golf putting kinematics. Adaptation to external physical randomness during virtual training may therefore help golfers adapt to external randomness in real-world environments.

  16. Implementace marketingového mixu Prague City Golf Club

    OpenAIRE

    Čmakal, Tomáš

    2012-01-01

    Title: Marketing mix implementation of Prague City Golf Club Objective: Analysis of marketing mix of the golf resort Prague City Golf Club and addresses proposals for its further improvement Methods: PEST analysis SWOT analysis Porter five forces analysis In-depth interview Results: The results of assessment of the marketing mix instruments of the Prague City Golf Club have shown that it is a high-quality golf resort with elaborate and numerous components of the marketing mix. In terms of com...

  17. Analysis of impact noise induced by hitting of titanium head golf driver.

    Science.gov (United States)

    Kim, Young Ho; Kim, Young Chul; Lee, Jun Hee; An, Yong-Hwi; Park, Kyung Tae; Kang, Kyung Min; Kang, Yeon June

    2014-11-01

    The hitting of titanium head golf driver against golf ball creates a short duration, high frequency impact noise. We analyzed the spectra of these impact noises and evaluated the auditory hazards from exposure to the noises. Noises made by 10 titanium head golf drivers with five maximum hits were collected, and the spectra of the pure impact sounds were studied using a noise analysis program. The noise was measured at 1.7 m (position A) and 3.4 m (position B) from the hitting point in front of the hitter and at 3.4 m (position C) behind the hitting point. Average time duration was measured and auditory risk units (ARUs) at position A were calculated using the Auditory Hazard Assessment Algorithm for Humans. The average peak levels at position A were 119.9 dBA at the sound pressure level (SPL) peak and 100.0 dBA at the overall octave level. The average peak levels (SPL and overall octave level) at position B were 111.6 and 96.5 dBA, respectively, and at position C were 111.5 and 96.7 dBA, respectively. The average time duration and ARUs measured at position A were 120.6 ms and 194.9 units, respectively. Although impact noises made by titanium head golf drivers showed relatively low ARUs, individuals enjoying golf frequently may be susceptible to hearing loss due to the repeated exposure of this intense impact noise with short duration and high frequency. Unprotected exposure to impact noises should be limited to prevent cochleovestibular disorders.

  18. INJURIES IN DISC GOLF - A DESCRIPTIVE CROSS-SECTIONAL STUDY

    DEFF Research Database (Denmark)

    Rahbek, Martin Amadeus; Nielsen, Rasmus Oestergaard

    2016-01-01

    BACKGROUND: Disc golf is rapidly increasing in popularity and more than two million people are estimated to regularly participate in disc golf activities. Despite this popularity, the epidemiology of injuries in disc golf remains under reported. PURPOSE: The purpose of the present study...... was to investigate the prevalence and anatomic distribution of injuries acquired through disc-golf participation in Danish disc golf players. METHODS: The study was a cross-sectional study conducted on Danish disc-golf players. In May 2015, invitations to complete a web-based questionnaire were spread online via...... social media, and around disc-golf courses in Denmark. The questionnaire included questions regarding disc-golf participation and the characteristics of injuries acquired through disc golf participation. The data was analyzed descriptively. RESULTS: An injury prevalence of 13.3% (95% CI: 6.7% to 19...

  19. Electromyographic Patterns during Golf Swing: Activation Sequence Profiling and Prediction of Shot Effectiveness.

    Science.gov (United States)

    Verikas, Antanas; Vaiciukynas, Evaldas; Gelzinis, Adas; Parker, James; Olsson, M Charlotte

    2016-04-23

    This study analyzes muscle activity, recorded in an eight-channel electromyographic (EMG) signal stream, during the golf swing using a 7-iron club and exploits information extracted from EMG dynamics to predict the success of the resulting shot. Muscles of the arm and shoulder on both the left and right sides, namely flexor carpi radialis, extensor digitorum communis, rhomboideus and trapezius, are considered for 15 golf players (∼5 shots each). The method using Gaussian filtering is outlined for EMG onset time estimation in each channel and activation sequence profiling. Shots of each player revealed a persistent pattern of muscle activation. Profiles were plotted and insights with respect to player effectiveness were provided. Inspection of EMG dynamics revealed a pair of highest peaks in each channel as the hallmark of golf swing, and a custom application of peak detection for automatic extraction of swing segment was introduced. Various EMG features, encompassing 22 feature sets, were constructed. Feature sets were used individually and also in decision-level fusion for the prediction of shot effectiveness. The prediction of the target attribute, such as club head speed or ball carry distance, was investigated using random forest as the learner in detection and regression tasks. Detection evaluates the personal effectiveness of a shot with respect to the player-specific average, whereas regression estimates the value of target attribute, using EMG features as predictors. Fusion after decision optimization provided the best results: the equal error rate in detection was 24.3% for the speed and 31.7% for the distance; the mean absolute percentage error in regression was 3.2% for the speed and 6.4% for the distance. Proposed EMG feature sets were found to be useful, especially when used in combination. Rankings of feature sets indicated statistics for muscle activity in both the left and right body sides, correlation-based analysis of EMG dynamics and features

  20. Electromyographic Patterns during Golf Swing: Activation Sequence Profiling and Prediction of Shot Effectiveness

    Directory of Open Access Journals (Sweden)

    Antanas Verikas

    2016-04-01

    Full Text Available This study analyzes muscle activity, recorded in an eight-channel electromyographic (EMG signal stream, during the golf swing using a 7-iron club and exploits information extracted from EMG dynamics to predict the success of the resulting shot. Muscles of the arm and shoulder on both the left and right sides, namely flexor carpi radialis, extensor digitorum communis, rhomboideus and trapezius, are considered for 15 golf players (∼5 shots each. The method using Gaussian filtering is outlined for EMG onset time estimation in each channel and activation sequence profiling. Shots of each player revealed a persistent pattern of muscle activation. Profiles were plotted and insights with respect to player effectiveness were provided. Inspection of EMG dynamics revealed a pair of highest peaks in each channel as the hallmark of golf swing, and a custom application of peak detection for automatic extraction of swing segment was introduced. Various EMG features, encompassing 22 feature sets, were constructed. Feature sets were used individually and also in decision-level fusion for the prediction of shot effectiveness. The prediction of the target attribute, such as club head speed or ball carry distance, was investigated using random forest as the learner in detection and regression tasks. Detection evaluates the personal effectiveness of a shot with respect to the player-specific average, whereas regression estimates the value of target attribute, using EMG features as predictors. Fusion after decision optimization provided the best results: the equal error rate in detection was 24.3% for the speed and 31.7% for the distance; the mean absolute percentage error in regression was 3.2% for the speed and 6.4% for the distance. Proposed EMG feature sets were found to be useful, especially when used in combination. Rankings of feature sets indicated statistics for muscle activity in both the left and right body sides, correlation-based analysis of EMG

  1. Estonian Golf & Country Club / Urmas Oja

    Index Scriptorium Estoniae

    Oja, Urmas, 1981-2012

    2005-01-01

    Konkursil "Eesti parim puitehitis 2005" pälvis voodrilaua eripreemia Jõelähtme Estonian Golf & Country Club'i katus. Arhitekt Andres Siim. Sisearhitekt Juta Lember. Konstruktor: AS Resand. 11 värv. ill

  2. Tourism Areas - MDC_GolfCourse

    Data.gov (United States)

    NSGIC Local Govt | GIS Inventory — A polygon feature class of all known Golf Courses within Miami-Dade County. Data was extracted from U.S. GDT Large Area Landmarks dataset, which represents common...

  3. Different centre of pressure patterns within the golf stroke II: group-based analysis.

    Science.gov (United States)

    Ball, K A; Best, R J

    2007-05-01

    Although the golf coaching literature stresses the importance of weight transfer during the swing, research has been conflicting or lacking statistical support. A potential problem with previous studies is that no attempt was made to account for different movement strategies in the golf swing. This study evaluated the relationship between centre of pressure measures and club head velocity within two previously identified swing styles, the "Front Foot" and "Reverse" styles. Thirty-nine Front Foot golfers and 19 Reverse golfers performed swings with a driver while standing on two force plates. From the force plate data, centre of pressure displacement, velocity, range, and timing parameters were calculated. Correlation and regression analysis indicated that a larger range of centre of pressure and a more rapid centre of pressure movement in the downswing was associated with a larger club head velocity at ball contact for the Front Foot group. For the Reverse golfers, positioning the centre of pressure further from the back foot at late backswing and a more rapid centre of pressure transfer towards the back foot at ball contact was associated with a larger club head velocity at ball contact. This study has highlighted the importance of identifying different movement strategies before evaluating performance measures, as different parameters were found to be important for the Front Foot and Reverse styles.

  4. Effects of golf courses on local biodiversity.

    OpenAIRE

    Gange, A.C.; Tanner, R.A.

    2005-01-01

    There are approximately 2600 golf courses in the UK, occupying 0.7% of the total land cover. However, it is unknown whether these represent a significant resource, in terms of biodiversity conservation, or if they are significantly less diverse than the surrounding habitats. The diversity of vegetation (tree and herbaceous species) and three indicator taxa (birds, ground beetles (Coleoptera, Carabidae) and bumblebees (Hymenoptera, Apidae)) was studied on nine golf courses and nine adja...

  5. Golf hand prosthesis performance of transradial amputees.

    Science.gov (United States)

    Carey, Stephanie L; Wernke, Matthew M; Lura, Derek J; Kahle, Jason T; Dubey, Rajiv V; Highsmith, M Jason

    2015-06-01

    Typical upper limb prostheses may limit sports participation; therefore, specialized terminal devices are often needed. The purpose of this study was to evaluate the ability of transradial amputees to play golf using a specialized terminal device. Club head speed, X-factor, and elbow motion of two individuals with transradial amputations using an Eagle Golf terminal device were compared to a non-amputee during a golf swing. Measurements were collected pre/post training with various stances and grips. Both prosthesis users preferred a right-handed stance initially; however, after training, one preferred a left-handed stance. The amputees had slower club head speeds and a lower X-factor compared to the non-amputee golfer, but increased their individual elbow motion on the prosthetic side after training. Amputees enjoyed using the device, and it may provide kinematic benefits indicated by the increase in elbow flexion on the prosthetic side. The transradial amputees were able to swing a golf club with sufficient repetition, form, and velocity to play golf recreationally. Increased elbow flexion on the prosthetic side suggests a potential benefit from using the Eagle Golf terminal device. Participating in recreational sports can increase amputees' health and quality of life. © The International Society for Prosthetics and Orthotics 2014.

  6. Berkeley High-Resolution Ball

    International Nuclear Information System (INIS)

    Diamond, R.M.

    1984-10-01

    Criteria for a high-resolution γ-ray system are discussed. Desirable properties are high resolution, good response function, and moderate solid angle so as to achieve not only double- but triple-coincidences with good statistics. The Berkeley High-Resolution Ball involved the first use of bismuth germanate (BGO) for anti-Compton shield for Ge detectors. The resulting compact shield permitted rather close packing of 21 detectors around a target. In addition, a small central BGO ball gives the total γ-ray energy and multiplicity, as well as the angular pattern of the γ rays. The 21-detector array is nearly complete, and the central ball has been designed, but not yet constructed. First results taken with 9 detector modules are shown for the nucleus 156 Er. The complex decay scheme indicates a transition from collective rotation (prolate shape) to single- particle states (possibly oblate) near spin 30 h, and has other interesting features

  7. Immediate Effects of Sports Taping Applied on the Lead Knee of Low- and High-Handicapped Golfers During Golf Swing.

    Science.gov (United States)

    Kim, Tae-Gyu; Kim, Eun-Kuk; Park, Jong-Chul

    2017-04-01

    Kim, T-G, Kim, E-K, and Park, J-C. Immediate effects of sports taping applied on the lead knee of low- and high-handicapped golfers during golf swing. J Strength Cond Res 31(4): 981-989, 2017-Elite golf athletes suffer from various musculoskeletal injuries due to repeated golf swings. Repetitive varus moment during golf swing has been suggested as a possible cause of injuries to the lead knee. The aim of this study was to objectively and quantitatively evaluate the immediate effects of sports taping on the lead knee of elite golfers to restrict varus moment. Thirty-one elite golfers were assigned to the low- (LHG, n = 15) or high-handicapped group (HHG, n = 16). Using 3-dimensional motion analysis, the lead knee position on the frontal plane with and without rigid taping (RT), elastic taping (ET), and placebo taping was identified in 4 separate phases by the 5 events of golf swing as follows: the peak of the backswing (E1), parallel to the ground during downswing (E2), ball impact (E3), parallel to the ground during follow-through (E4), and finish (E5). The LHG when using a driver club had decreased movement toward knee varus with RT and ET than that without it from E1 to E2 (p = 0.001). The LHG when using a 5-iron club decreased movement toward knee varus with RT than that without it from E1 to E2 (p = 0.006) and from E2 to E3 (p = 0.019). The HHG when using a driver club had decreased movement toward knee varus with RT from E1 to E2 (p = 0.014). Sports taping may be helpful for elite golfers in terms of reducing varus moment of the lead knee during the downswing and be useful for the development of preventive strategies for golf-related knee injuries.

  8. Archery - Golf Guide with Official Rules. June 1972 - June 1974.

    Science.gov (United States)

    Driscoll, Margaret L., Ed.; Michalson, Doddy, Ed.

    This guide for women's archery and golf dated June 1972 - June 1974 details rules and standards as well as the Division for Girls and Women's Sports (DGWS) statement of beliefs. Articles on archery nomenclature, archery interest builders, and archery golf are included in the section on archery. Articles dealing with golf take up such topics as…

  9. Having a Ball with Fitness Balls

    Science.gov (United States)

    McNulty, Betty

    2011-01-01

    Fitness programs can be greatly enhanced with the addition of fitness balls. They are a fun, challenging, economical, and safe way to incorporate a cardiovascular, strength, and stretching program for all fitness levels in a physical education setting. The use of these balls has become more popular during the last decade, and their benefits and…

  10. The Goldenrod Ball Gall

    Science.gov (United States)

    Fischer, Richard B.

    1974-01-01

    The paper presents a generalized life history of the goldenrod ball gall, a ball-shaped swelling found almost exclusively on the Canada goldenrod, Solidago canadensis, and caused by a peacock fly know as Eurosta soldiaginis. (KM)

  11. The incredible shrinking ball

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Maurice

    2011-12-15

    In the oil and gas industry, the implementation of fracture systems using ball and seat technology helped make multistage fracturing possible. However, frac balls can obstruct later production flow by staying in the well. Baker Hughes Inc. developed a technology to solve this problem: IN-Tallic frac balls. The unique feature of these frac balls is that they are made of an electrolytic metallic nanostructured material which is light and strong and which melts away with salt water or brine through a decomposition process governed by electrochemical reactions controlled by nanoscale coatings. These balls need to be kept away from moisture in order to prevent degradation. This technology is more expensive than traditional frac balls but it prevents the need to mill out obstructions created by the balls. The IN-Tallic frac balls are a new technology which provides operators with peace of mind.

  12. Ball Screw Actuator Including a Compliant Ball Screw Stop

    Science.gov (United States)

    Wingett, Paul T. (Inventor); Hanlon, Casey (Inventor)

    2017-01-01

    An actuator includes a ball nut, a ball screw, and a ball screw stop. The ball nut is adapted to receive an input torque and in response rotates and supplies a drive force. The ball screw extends through the ball nut and has a first end and a second end. The ball screw receives the drive force from the ball nut and in response selectively translates between a retract position and a extend position. The ball screw stop is mounted on the ball screw proximate the first end to translate therewith. The ball screw stop engages the ball nut when the ball screw is in the extend position, translates, with compliance, a predetermined distance toward the first end upon engaging the ball nut, and prevents further rotation of the ball screw upon translating the predetermined distance.

  13. Pärnu Bay Golf Club = Pärnu Bay Golf Club / Arhitekt11

    Index Scriptorium Estoniae

    2016-01-01

    Pärnu Bay Golf Club, arhitektid Jürgen Lepper, Anto Savi, Margus Soonets, Janar Toomesso (Arhitekt11), sisearhitektid Liina Vaino, Kaari Metslang, Hannelore Kääramees (Arhitekt11). Kultuurkapitali Arhitektuuri sihtkapitali aastapreemia nominent 2016

  14. Coefficient of restitution of sports balls: A normal drop test

    International Nuclear Information System (INIS)

    Haron, Adli; Ismail, K A

    2012-01-01

    Dynamic behaviour of bodies during impact is investigated through impact experiment, the simplest being a normal drop test. Normally, a drop test impact experiment involves measurement of kinematic data; this includes measurement of incident and rebound velocity in order to calculate a coefficient of restitution (COR). A high speed video camera is employed for measuring the kinematic data where speed is calculated from displacement of the bodies. Alternatively, sensors can be employed to measure speeds, especially for a normal impact where there is no spin of the bodies. This paper compares experimental coefficients of restitution (COR) for various sports balls, namely golf, table tennis, hockey and cricket. The energy loss in term of measured COR and effects of target plate are discussed in relation to the material and construction of these sports balls.

  15. Imaging the Sport of Golf – Envisioning Communities

    Directory of Open Access Journals (Sweden)

    Emese Ivan

    2008-01-01

    Full Text Available Hungary also has seen a tremendous increase in quality golf facilities in the last decade. The sport of golf – including golf tourism – in Hungary also makes it first moves to be officially (reunified with its historical partners in Western Europe and in the USA. This paper looks at developments in Hungarian Golf community in the last decades. While focusing on the ongoing economic, financial, and political changes surrounding the Hungarian National Golf Federation, this study also poses some questions. To what extent mushrooming of golf communities could be seen as a result of Europeanization of the country? Is it just a new achievement in PGA America’s global explosion? Can we see it as the benefit of the European Team’s astronomical success at the Ryder Cup tournaments?

  16. Sensorimotor Rhythm Neurofeedback Enhances Golf Putting Performance.

    Science.gov (United States)

    Cheng, Ming-Yang; Huang, Chung-Ju; Chang, Yu-Kai; Koester, Dirk; Schack, Thomas; Hung, Tsung-Min

    2015-12-01

    Sensorimotor rhythm (SMR) activity has been related to automaticity during skilled action execution. However, few studies have bridged the causal link between SMR activity and sports performance. This study investigated the effect of SMR neurofeedback training (SMR NFT) on golf putting performance. We hypothesized that preelite golfers would exhibit enhanced putting performance after SMR NFT. Sixteen preelite golfers were recruited and randomly assigned into either an SMR or a control group. Participants were asked to perform putting while electroencephalogram (EEG) was recorded, both before and after intervention. Our results showed that the SMR group performed more accurately when putting and exhibited greater SMR power than the control group after 8 intervention sessions. This study concludes that SMR NFT is effective for increasing SMR during action preparation and for enhancing golf putting performance. Moreover, greater SMR activity might be an EEG signature of improved attention processing, which induces superior putting performance.

  17. An operation management system for golf tournament

    OpenAIRE

    Yuan Yijun; Luo Hanwen

    2017-01-01

    In this paper,an operation management system for golf tournament is designed to calculate the beginning and finishing dates of the preparation automatically.The efficiency of management work during preparatory period,such as meetings before match and task announcement,is raised by nearly 40% after using our system than using traditional management tools or other software systems.And the probability of occurrence of delay and omission of work are controlled within 5%.It is proved to be helpful...

  18. Going golfing in Norway: consumer motivation

    OpenAIRE

    Mukhamodeev, Maxim

    2012-01-01

    Master's thesis in International hotel and tourism management Golf development has been quite rapid in the past years all over the world. The purpose of this study is to analyze the validity and reliability of Motivation Sport Consumer scale proposed by McDonald et al. and its applicability to Holt‘s typology of consumption metaphors. The results of reliability tests and factor analysis confirm that the present instrumentation has demonstrated satisfactory psychometric properties overall t...

  19. Return to Golf After Lumbar Fusion.

    Science.gov (United States)

    Shifflett, Grant D; Hellman, Michael D; Louie, Philip K; Mikhail, Christopher; Park, Kevin U; Phillips, Frank M

    Spinal fusion surgery is being increasingly performed, yet few studies have focused on return to recreational sports after lumbar fusion and none have specifically analyzed return to golf. Most golfers successfully return to sport after lumbar fusion surgery. Case series. Level 4. All patients who underwent 1- or 2-level primary lumbar fusion surgery for degenerative pathologies performed by a single surgeon between January 2008 and October 2012 and had at least 1-year follow-up were included. Patients completed a specifically designed golf survey. Surveys were mailed, given during follow-up clinic, or answered during telephone contact. A total of 353 patients met the inclusion and exclusion criteria, with 200 responses (57%) to the questionnaire producing 34 golfers. The average age of golfers was 57 years (range, 32-79 years). In 79% of golfers, preoperative back and/or leg pain significantly affected their ability to play golf. Within 1 year from surgery, 65% of patients returned to practice and 52% returned to course play. Only 29% of patients stated that continued back/leg pain limited their play. Twenty-five patients (77%) were able to play the same amount of golf or more than before fusion surgery. Of those providing handicaps, 12 (80%) reported the same or an improved handicap. More than 50% of golfers return to on-course play within 1 year of lumbar fusion surgery. The majority of golfers can return to preoperative levels in terms of performance (handicap) and frequency of play. This investigation offers insight into when golfers return to sport after lumbar fusion surgery and provides surgeons with information to set realistic expectations postoperatively.

  20. Golf Plus - more space and more functionality; Golf Plus: Raumangebot auf Kundenwunsch

    Energy Technology Data Exchange (ETDEWEB)

    Martin, F.; Jaeschke, J.; Repmann, C.; Tinschert, T. [Volkswagen AG, Wolfsburg (Germany)

    2005-01-01

    A decisive factor in the design of cars in the Golf class, which have a relatively small floor area, is to make the best possible use of the interior space. The objective behind the development of the Golf Plus was to offer even more space than the Golf V. The length and width of the car remained unchanged, but the height was raised by 95 mm to 1580 mm, which allowed the head and shoulder room to be increased significantly. The improve all-round visibility, the front seats were raised by 75 mm and the rear seats by 85 mm. The result is a more comfortable sitting position, in particular for passengers in the back of the car, and easier access to the interior of the car. In order to obtain detailed information about the aerodynamic properties of the Golf Plus at an early stage of development, a numerical simulation was carried out at the beginning of the project to evaluate the flows around the outer skin of the design model using CAD descriptions. Later in the project, wind tunnel tests gradually replaced the calculations. For these tests, a 1:1 scale wind tunnel model with all the component groups was built on the original platform. This allowed the flow of cool air to the radiator and the front brakes to be optimised at an early stage. As the Golf Plus is based on the same platform as the Golf V, it benefits form the aerodynamic development work already carried out on the underside of the car. In order to reduce drag, the position and size of the front spoiler were improved. The rear spoiler lip has an effect both on drag and on the lift on the rear axle, which is decisive for the car's handling. Taking these factors into account, the spoiler lip was designed to produce a rear lift coefficient of c{sub AH}<0.1. (orig.)

  1. Micro structrual characterization and analysis of ball milled silicon carbide

    Science.gov (United States)

    Madhusudan, B. M.; Raju, H. P.; Ghanaraja., S.

    2018-04-01

    Mechanical alloying has been one of the prominent methods of powder synthesis technique in solid state involving cyclic deformation, cold welding and fracturing of powder particles. Powder particles in this method are subjected to greater mechanical deformation due to the impact of ball-powder-ball and ball-powder-container collisions that occurs during mechanical alloying. Strain hardening and fracture of particles decreases the size of the particles and creates new surfaces. The objective of this Present work is to use ball milling of SiC powder for different duration of 5, 10, 15 and 20 hours by High energy planetary ball milling machine and to evaluate the effect of ball milling on SiC powder. Micro structural Studies using Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD) and EDAX has been investigated.

  2. Compact Q-balls

    Energy Technology Data Exchange (ETDEWEB)

    Bazeia, D., E-mail: bazeia@fisica.ufpb.br [Departamento de Física, Universidade Federal da Paraíba, 58051-970 João Pessoa, PB (Brazil); Losano, L.; Marques, M.A. [Departamento de Física, Universidade Federal da Paraíba, 58051-970 João Pessoa, PB (Brazil); Menezes, R. [Departamento de Ciências Exatas, Universidade Federal da Paraíba, 58297-000 Rio Tinto, PB (Brazil); Departamento de Física, Universidade Federal de Campina Grande, 58109-970 Campina Grande, PB (Brazil); Rocha, R. da [Centro de Matemática, Computação e Cognição, Universidade Federal do ABC, 09210-580 Santo André (Brazil)

    2016-07-10

    In this work we deal with non-topological solutions of the Q-ball type in two space–time dimensions, in models described by a single complex scalar field that engenders global symmetry. The main novelty is the presence of stable Q-balls solutions that live in a compact interval of the real line and appear from a family of models controlled by two distinct parameters. We find analytical solutions and study their charge and energy, and show how to control the parameters to make the Q-balls classically and quantum mechanically stable.

  3. Mapping soil water content on golf course greens with GPR

    Science.gov (United States)

    Ground-penetrating radar (GPR) can be an effective and efficient method for high-resolution mapping of volumetric water content in the sand layer directly beneath the ground surface at a golf course green. This information could potentially be very useful to golf course superintendents for determi...

  4. Leidos Reclaims Defelice Cup at Annual Golf Tournament | Poster

    Science.gov (United States)

    By Ashley DeVine, Staff Writer Leidos Biomedical Research reclaimed the Defelice Cup trophy from NCI at the eighth annual Ronald H. Defelice golf tournament, held October 14. The final score was 15–7, with Leidos Biomed tying the series 4 to 4. Fourteen players on each team battled it out at Rattlewood golf course in Mount Airy, Md.

  5. Using Sport Education to Teach the Lifetime Sport of Golf

    Science.gov (United States)

    Scarboro, Shot; Pritchard, Tony

    2015-01-01

    Golf is a lifetime sport activity that can be taught in physical education classes. How one teaches golf in physical education could influence whether students will want to continue to participate outside of physical education. The sport education model (SEM) is an instructional model that promotes student learning in all three domains by ensuring…

  6. Lower extremity work is associated with club head velocity during the golf swing in experienced golfers.

    Science.gov (United States)

    McNally, M P; Yontz, N; Chaudhari, A M

    2014-08-01

    While the golf swing is a complex whole body movement requiring coordination of all joints to achieve maximum ball velocity, the kinetic contribution of the lower extremities to club head velocity has not been quantified, despite the perception that the legs are a primary source of power during the swing. Mechanical power at the hips, knees, and ankles was estimated during the downswing phase of a full swing with a driver using a passive optical motion capture system and 2 force plates for adult males across a range of age and self-reported skill levels. Total work by the lower extremities was calculated by integrating the powers of all 6 joints over the downswing. Regression analyses showed that total lower extremity work was a strong predictor of club head velocity (R=0.63). Secondary analyses showed different relationships to club head velocity in lead and trail leg lower extremity joints, but none of these were as predictive of club head velocity as the total work performed by the lower extremities. These results provide quantitative evidence that the lower body's kinetic contribution may be an important factor in achieving greater club head velocity, contributing to greater driving distance and overall golf performance. © Georg Thieme Verlag KG Stuttgart · New York.

  7. 75 FR 52360 - Upper Truckee River Restoration and Golf Course Reconfiguration Project, El Dorado County, CA

    Science.gov (United States)

    2010-08-25

    ... DEPARTMENT OF THE INTERIOR Bureau of Reclamation Upper Truckee River Restoration and Golf Course... and comment the draft EIR/EIS for the Upper Truckee River Restoration and Golf Course Reconfiguration... include continuing existing golf course use, removal of the entire Lake Tahoe Golf Course, or...

  8. Movement Variability in the Golf Swing: Theoretical, Methodological, and Practical Issues

    Science.gov (United States)

    Glazier, Paul

    2011-01-01

    Movement variability in the golf swing has recently been identified as a priority for future research in golf science. Although this ubiquitous aspect of golf performance has featured in previous empirical investigations of the golf swing, it has tended to be subordinate and studied as an adjunct to other more conventional research questions.…

  9. In vivo kinematics of healthy male knees during squat and golf swing using image-matching techniques.

    Science.gov (United States)

    Murakami, Koji; Hamai, Satoshi; Okazaki, Ken; Ikebe, Satoru; Shimoto, Takeshi; Hara, Daisuke; Mizu-uchi, Hideki; Higaki, Hidehiko; Iwamoto, Yukihide

    2016-03-01

    Participation in specific activities requires complex ranges of knee movements and activity-dependent kinematics. The purpose of this study was to investigate dynamic knee kinematics during squat and golf swing using image-matching techniques. Five healthy males performed squats and golf swings under periodic X-ray images at 10 frames per second. We analyzed the in vivo three-dimensional kinematic parameters of subjects' knees, namely the tibiofemoral flexion angle, anteroposterior (AP) translation, and internal-external rotation, using serial X-ray images and computed tomography-derived, digitally reconstructed radiographs. During squat from 0° to 140° of flexion, the femur moved about 25 mm posteriorly and rotated 19° externally relative to the tibia. Screw-home movement near extension, bicondylar rollback between 20° and 120° of flexion, and medial pivot motion at further flexion were observed. During golf swing, the leading and trailing knees (the left and right knees respectively in the right-handed golfer) showed approximately five millimeters and four millimeters of AP translation with 18° and 26° of axial rotation, respectively. A central pivot motion from set-up to top of the backswing, lateral pivot motion from top to ball impact, and medial pivot motion from impact to the end of follow-through were observed. The medial pivot motion was not always recognized during both activities, but a large range of axial rotation with bilateral condylar AP translations occurs during golf swing. This finding has important implications regarding the amount of acceptable AP translation and axial rotation at low flexion in replaced knees. IV. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. An operation management system for golf tournament

    Directory of Open Access Journals (Sweden)

    Yuan Yijun

    2017-02-01

    Full Text Available In this paper,an operation management system for golf tournament is designed to calculate the beginning and finishing dates of the preparation automatically.The efficiency of management work during preparatory period,such as meetings before match and task announcement,is raised by nearly 40% after using our system than using traditional management tools or other software systems.And the probability of occurrence of delay and omission of work are controlled within 5%.It is proved to be helpful for reducing management costs and improving efficiency of tournament management company.

  11. The bowling balls

    CERN Multimedia

    CERN Bulletin

    2010-01-01

    10 November 1972: CERN’s Bent Stumpe places an order for 12 bowling balls for a total cost of 95 US dollars. Although not evident at first sight, he is buying the heart of some of the first tracking devices to be used in the SPS control room. Today, Bent Stumpe’s device would be called a desktop mouse…   The first order for 4 bowling balls later changed to 12 balls. The bowling balls became the heart of Bent Stumpe's mouse. Almost 40 years ago, the web, Wikipedia and Google did not exist and it was much more difficult to know whether other people in other parts of the world or even in the same laboratory were facing the same problems or developing the same tools. At that time, Bent Stumpe was an electronics engineer, newly recruited to work on developments for the SPS Central Control room. One of the things his supervisor asked him to build as soon as possible was a device to control a pointer on a screen, also called a tracker ball. The heart of the device was the...

  12. Some applications of mathematics in golf.

    Science.gov (United States)

    Otto, S R

    2017-08-01

    At its core, like many other sports, golf is a game of integers. The minimization of the number of strokes played is generally what determines the winner, whether each of these are associated with the shortest of putts or the longest of drives. The outcomes of these shots are influenced by very slight changes, but hopefully in a deterministic sense. Understanding the mechanics of golf necessitates the development of models and this is coupled more often than not to the use of statistics. In essence, the individual aspects of the sport can be modelled adequately via fairly simplistic models, but the presence of a human at one end of the kinematic chain has a significant impact on the variability of the entire process. In this paper, we will review some of the ways that mathematics has been used to develop the understanding of the physical processes involved in the sport, including some of the analysis which is exploited within the Equipment Rules. We will also discuss some of the future challenges.

  13. THE SOCIAL LEGITIMACY OF GOLF TOURISM: AN APPLICATION TO THE GOLF COURSES OF ANDALUSIA

    Directory of Open Access Journals (Sweden)

    Francisco Riquel-Ligero

    2011-12-01

    Full Text Available Today, respect for the natural environmental is a variable that plays animportant role when it comes to configuring a tourist destination orproduct, particularly since this is an industry for which the location isirrevocably fixed. Andalusia, in particular, has become well-establishedas a major golf tourism destination. It has more golf courses than anyother of the 17 Spanish Autonomous Regions. This has stimulated adebate on the environmental impacts of sporting facilities of this type,with attention consequently focused on the need of these tourismcompanies to achieve and maintain social legitimacy. In the workdescribed here, the Partial Least Squares (PLS technique is applied to analyse the impact of the institutional context on the implementation of environmental practices and the achievement of social legitimacy by these organisations.

  14. Golf science research at the beginning of the twenty-first century.

    Science.gov (United States)

    Farrally, M R; Cochran, A J; Crews, D J; Hurdzan, M J; Price, R J; Snow, J T; Thomas, P R

    2003-09-01

    At the beginning of the twenty-first century, there are 30,000 golf courses and 55 million people who play golf worldwide. In the USA alone, the value of golf club memberships sold in the 1990s was US dollar 3.2 billion. Underpinning this significant human activity is a wide variety of people researching and applying science to sustain and develop the game. The 11 golf science disciplines recognized by the World Scientific Congress of Golf have reported 311 papers at four world congresses since 1990. Additionally, scientific papers have been published in discipline-specific peer-reviewed journals, research has been sponsored by the two governing bodies of golf, the Royal and Ancient Golf Club of St. Andrews and the United States Golf Association, and confidential research is undertaken by commercial companies, especially equipment manufacturers. This paper reviews much of this human endeavour and points the way forward for future research into golf.

  15. Laboratory demonstration of ball lightning

    International Nuclear Information System (INIS)

    Egorov, Anton I; Stepanov, Sergei I; Shabanov, Gennadii D

    2004-01-01

    A common laboratory facility for creating glowing flying plasmoids akin to a natural ball lightning, allowing a number of experiments to be performed to investigate the main properties of ball lightning, is described. (methodological notes)

  16. Golf tourism in South Africa: Profiling attendees at a major ...

    African Journals Online (AJOL)

    Golf tourism in South Africa: Profiling attendees at a major championship event. ... from the less developed and developing context from an impact perspective. ... participated in various tourism activities that contributed to the local economy.

  17. Ejection of a rear facing, golf cart passenger.

    Science.gov (United States)

    Schau, Kyle; Masory, Oren

    2013-10-01

    The following report details the findings of a series of experiments and simulations performed on a commercially available, shuttle style golf cart during several maneuvers involving rapid accelerations of the vehicle. It is determined that the current set of passive restraints on these types of golf carts are not adequate in preventing ejection of a rear facing passenger during rapid accelerations in the forward and lateral directions. Experimental data and simulations show that a hip restraint must be a minimum of 13 in. above the seat in order to secure a rear facing passenger during sharp turns, compared to the current restraint height of 5 in. Furthermore, it is determined that a restraint directly in front of the rear facing passenger is necessary to prevent ejection. In addressing these issues, golf cart manufacturers could greatly reduce the likelihood of injury due to ejection of a rear facing, golf cart passenger. Copyright © 2013 Elsevier Ltd. All rights reserved.

  18. Golf in the United States: an evolution of accessibility.

    Science.gov (United States)

    Parziale, John R

    2014-09-01

    Golf affords physical and psychological benefits to persons who are physically challenged. Advances in adaptive technology, changes in golf course design, and rules modifications have enabled persons with neurological, musculoskeletal, and other impairments to play golf at a recreational, elite amateur, or professional level. The Americans with Disabilities Act has been cited in both federal and US Supreme Court rulings that have improved access for physically challenged golfers. Medical specialties, including physiatry, have played an important role in this process. This article reviews the history of golf's improvements in accessibility, and provides clinicians and physically challenged golfers with information that will facilitate participation in the sport. Copyright © 2014 American Academy of Physical Medicine and Rehabilitation. Published by Elsevier Inc. All rights reserved.

  19. Relationships between clubshaft motions and clubface orientation during the golf swing.

    Science.gov (United States)

    Takagi, Tokio; Yokozawa, Toshiharu; Inaba, Yuki; Matsuda, Yuji; Shiraki, Hitoshi

    2017-09-01

    Since clubface orientation at impact affects ball direction and ball spin, the ability to control clubface orientation is one of the most important skills for golfers. This study presents a new method to describe clubface orientation as a function of the clubshaft motions (i.e., swing plane orientation, clubshaft angle in the swing plane, and clubshaft rolling angle) during a golf swing and investigates the relationships between the clubshaft motions and clubface orientation at impact. The club motion data of driver shots were collected from eight skilled golfers using a three-dimensional motion capture system. The degrees of influence of the clubshaft motions on the clubface orientation were investigated using sensitivity analysis. The sensitivity analysis revealed that the swing plane horizontal angle affected the clubface horizontal angle to an extent of 100%, that the clubshaft angle in the swing plane affected both the clubface vertical and horizontal angles to extents of 74 and 68%, respectively, and that the clubshaft rolling angle affected both the clubface vertical and horizontal angles to extents of -67 and 75%, respectively. Since the method presented here relates clubface orientation to clubshaft motions, it is useful for understanding the clubface control of a golfer.

  20. Increasing Minority Golf Participation Through PGA Education Initiatives

    Directory of Open Access Journals (Sweden)

    Jill Fjelstul

    2011-07-01

    Full Text Available The article provides a report on the successful acquisition of the Professional Golfers Association of America (PGA golf management university program by the University of Maryland, Eastern Shore (UMES. The PGA’s accredited program is housed at 20 universities with UMES being the first predominantly Black college to offer the coveted program. The article provides interview excerpts on the process undertaken by UMES. The article also identifies initiatives by programs and associations to increase minority golf participation.

  1. The role of physiology in the development of golf performance.

    Science.gov (United States)

    Smith, Mark F

    2010-08-01

    The attainment of consistent high performance in golf requires effective physical conditioning that is carefully designed and monitored in accordance with the on-course demands the player will encounter. Appreciating the role that physiology plays in the attainment of consistent performance, and how a player's physicality can inhibit performance progression, supports the notion that the application of physiology is fundamental for any player wishing to excel in golf. With cardiorespiratory, metabolic, hormonal, musculoskeletal and nutritional demands acting on the golfer within and between rounds, effective physical screening of a player will ensure physiological and anatomical deficiencies that may influence performance are highlighted. The application of appropriate golf-specific assessment methods will ensure that physical attributes that have a direct effect on golf performance can be measured reliably and accurately. With the physical development of golf performance being achieved through a process of conditioning with the purpose of inducing changes in structural and metabolic functions, training must focus on foundation whole-body fitness and golf-specific functional strength and flexibility activities. For long-term player improvement to be effective, comprehensive monitoring will ensure the player reaches an optimal physical state at predetermined times in the competitive season. Through continual assessment of a player's physical attributes, training effectiveness and suitability, and the associated adaptive responses, key physical factors that may impact most on performance success can be determined.

  2. Frictional performance of ball screw

    International Nuclear Information System (INIS)

    Nakashima, Katuhiro; Takafuji, Kazuki

    1985-01-01

    As feed screws, ball screws have become to be adopted in place of trapezoidal threads. The structure of ball screws is complex, but those are the indispensable component of NC machine tools and machining centers, and are frequently used for industrial robots. As the problems in the operation of ball screws, there are damage, life and the performance related to friction. As to the damage and life, though there is the problem of the load distribution on balls, the results of the research on rolling bearings are applied. The friction of ball screws consists of the friction of balls and a spiral groove, the friction of a ball and a ball, the friction in a ball-circulating mechanism and the viscous friction of lubricating oil. It was decided to synthetically examine the frictional performance of ball screws, such as driving torque, the variation of driving torque, efficiency, the formation of oil film and so on, under the working condition of wide range, using the screws with different accuracy and the nuts of various circuit number. The experimental setup and the processing of the experimental data, the driving performance of ball screws and so on are reported. (Kako, I.)

  3. Ball check valve

    International Nuclear Information System (INIS)

    Bevilacqua, F.

    1978-01-01

    A pressurized nuclear reactor having an instrument assembly sheathed in a metallic tube which is extended vertically upward into the reactor core by traversing a metallic guide tube which is welded to the wall of the vessel is described. Sensors in each instrument assembly are connected to instruments outside the vessel to manifest the conditions within the core. Each instrument assembly probe is moved into position within a metallic guide channel. The guide channel penetrates the wall of the vessel and forms part of the barrier to the environment within the pressure vessel. Each channel includes a ball check valve which is opened by the instrument assembly probe when the probe passes through the valve. A ball valve element is moved from its seat by the probe to a position lateral of the bore of the channel and is guided to its seat along a sloped path within the valve body when the probe is removed. 5 claims, 3 figures

  4. Improved hydrogen sorption kinetics in wet ball milled Mg hydrides

    Energy Technology Data Exchange (ETDEWEB)

    Meng, Li

    2011-05-04

    In this work, wet ball milling method is used in order to improve hydrogen sorption behaviour due to its improved microstructure of solid hydrogen materials. Compared to traditional ball milling method, wet ball milling has benefits on improvement of MgH{sub 2} microstructure and further influences on its hydrogen sorption behavior. With the help of solvent tetrahydrofuran (THF), wet ball milled MgH{sub 2} powder has much smaller particle size and its specific surface area is 7 times as large as that of dry ball milled MgH{sub 2} powder. Although after ball milling the grain size is decreased a lot compared to as-received MgH{sub 2} powder, the grain size of wet ball milled MgH{sub 2} powder is larger than that of dry ball milled MgH{sub 2} powder due to the lubricant effect of solvent THF during wet ball milling. The improved particle size and specific surface area of wet ball milled MgH{sub 2} powder is found to be determining its hydrogen sorption kinetics especially at relatively low temperatures. And it also shows good cycling sorption behavior, which decides on its industrial applicability. With three different catalysts MgH{sub 2} powder shows improved hydrogen sorption behavior as well as the cyclic sorption behavior. Among them, the Nb{sub 2}O{sub 5} catalyst is found to be the most effective one in this work. Compared to the wet ball milled MgH{sub 2} powder, the particle size and specific surface area of the MgH{sub 2} powder with catalysts are similar to the previous ones, while the grain size of the MgH{sub 2} with catalysts is much finer. In this case, two reasons for hydrogen sorption improvement are suggested: one is the reduction of the grain size. The other may be as pointed out in some literatures that formation of new oxidation could enhance the hydrogen sorption kinetics, which is also the reason why its hydrogen capacity is decreased compared to without catalysts. After further ball milling, the specific surface area of wet ball milled Mg

  5. Estimated Colorado Golf Course Irrigation Water Use, 2005

    Science.gov (United States)

    Ivahnenko, Tamara

    2009-01-01

    Golf course irrigation water-use data were collected as part of the U.S. Geological Survey National Water Use Program's 2005 compilation to provide baseline information, as no golf course irrigation water-use data (separate from crop irrigation) have been reported in previous compilations. A Web-based survey, designed by the U.S. Geological Survey, in cooperation with the Rocky Mountain Golf Course Superintendents Association (RMGCSA), was electronically distributed by the association to the 237 members in Colorado. Forty-three percent of the members returned the survey, and additional source water information was collected by telephone for all but 20 of the 245 association member and non-member Colorado golf courses. For golf courses where no data were collected at all, an average 'per hole' coefficient, based on returned surveys from that same county, were applied. In counties where no data were collected at all, a State average 'per hole' value of 13.2 acre-feet was used as the coefficient. In 2005, Colorado had 243 turf golf courses (there are 2 sand courses in the State) that had an estimated 2.27 acre-feet per irrigated course acre, and 65 percent of the source water for these courses was surface water. Ground water, potable water (public supply), and reclaimed wastewater, either partially or wholly, were source waters for the remaining courses. Fifty-three of the 64 counties in Colorado have at least one golf course, with the greatest number of courses in Jefferson (23 courses), Arapahoe (22 courses), and El Paso Counties (20 courses). In 2005, an estimated 5,647.8 acre-feet in Jefferson County, 5,402 acre-feet in Arapahoe County, and 4,473.3 acre-feet in El Paso County were used to irrigate the turf grass.

  6. Burrowing owl nesting productivity: A comparison between artificial and natural burrows on and off golf courses

    Science.gov (United States)

    Smith, M.D.; Conway, C.J.; Ellis, L.A.

    2005-01-01

    Burrowing owl (Athene cunicularia) populations are declining in many portions of their range, and lack of suitable nesting burrows is thought to be one reason for observed declines. Burrowing owls are attracted to golf courses because the birds generally nest and forage in short-grass, open areas, yet golf courses seldom have suitable nesting burrows. We examined the efficacy of installing artificial nesting burrows on golf courses as a way to help restore local burrowing owl populations. From 2001-2004 we monitored over 175 natural burrows off golf courses, 14 natural burrows on golf courses, 86 artificial burrows off golf courses, and 130 artificial burrows on golf courses. Owls located and used 8 of the 130 artificial burrows installed on golf courses (4 were used as nests). Owls selected burrows that were closer to existing natural burrows, farther from maintained areas (areas receiving turf maintenance by golf course staff), and farther from sprinkler heads. All 4 of the artificial burrows used as nests successfully fledged young, and annual site fidelity for owls nesting on golf courses was higher than for owls nesting off golf courses. However, annual fecundity of owls nesting on golf courses was lower than that of owls nesting off golf courses. If golf courses have sufficiently large nonmaintained areas and there are nesting owls nearby, course managers potentially can help in restoring local burrowing owl populations by installing artificial nesting burrows on the periphery of the course. However, the low fecundity on golf courses reported here should be more thoroughly examined before artificial burrows are used to attract owls to golf courses.

  7. Neutrons and the crystal ball experiments

    International Nuclear Information System (INIS)

    Alyea, J.; Grosnick, D.; Koetke, D.; Manweiler, R.; Spinka, H.; Stanislaus, S.

    1997-01-01

    The Crystal Ball detector, as originally constructed, consisted of a set of 672 optically-isolated NaI crystals, forming an approximately spherical shell and each crystal viewed by a photomultiplier, a charged-particle tracker within the NaI shell, and two endcaps to cover angles close to two colliding beams. The detector geometry subtends a solid angle of about 93% of 4π st (20 degree le θ le 160degree and 0degree le φ le 360degree) from the center. The Crystal Ball detector was used for two long series of experiments at the e + e - colliding beam accelerators SPEAR [1, 2, 3, 4] at SLAC and DORIS [5, 6, 7, 8] at DESY. A new set of measurements using the Crystal Ball detector is planned at the Brookhaven National Laboratory Alternating Gradient Synchrotrons (BNL AGS). These new experiments will use the 672 NaI crystals from the original detector, but neither the tracker nor endcaps. The ''Crystal Ball'' in this note will refer only to the set of NaI crystals. Initially, the reactions to be studied will include π - pr a rrow neutrals with pion beam momenta approximately400-750 MeV/c and K - pr a rrow neutrals with kaon beam momenta approximately600-750 MeV/c. Each of these reactions will include a neutron in the final state. whereas the fraction of e + e - interactions with neutrons at SLAC or DESY was quite small. Consequently, there is relatively little experience understanding the behavior of neutrons in the Crystal Ball

  8. Evaluation of children with ADHD on the Ball-Search Field Task.

    Science.gov (United States)

    Rosetti, Marcos F; Ulloa, Rosa E; Vargas-Vargas, Ilse L; Reyes-Zamorano, Ernesto; Palacios-Cruz, Lino; de la Peña, Francisco; Larralde, Hernán; Hudson, Robyn

    2016-01-25

    Searching, defined for the purpose of the present study as the displacement of an individual to locate resources, is a fundamental behavior of all mobile organisms. In humans this behavior underlies many aspects of everyday life, involving cognitive processes such as sustained attention, memory and inhibition. We explored the performance of 36 treatment-free children diagnosed with attention-deficit hyperactivity disorder (ADHD) and 132 children from a control school sample on the ecologically based ball-search field task (BSFT), which required them to locate and collect golf balls in a large outdoor area. Children of both groups enjoyed the task and were motivated to participate in it. However, performance showed that ADHD-diagnosed subjects were significantly less efficient in their searching. We suggest that the BSFT provides a promising basis for developing more complex ecologically-derived tests that might help to better identify particular cognitive processes and impairments associated with ADHD.

  9. Korean Golf Tourism in China: Place, Perception and Narratives

    Directory of Open Access Journals (Sweden)

    Jinah Park

    2018-04-01

    Full Text Available Tourism is a critical, cross-cultural social behavior in contemporary society and provides diverse experiences based on different regional resources in destinations. This research identified the attributes associated with Korean golf tourists’ images of seven destination regions in Mainland China. A content analysis of 328 golf tourists’ blogs indicated that each region had different combinations of destination attributes, but these were partially hidden in vivid descriptions of playing experiences. The narratives were coded with 15 golf destination attributes with 136 headwords and they reflected both place-centred images and interactions through perceptual experiences with different social groups. The golfers greatly appreciated congestion control at courses and social interaction during their tours, including the services of local human resources and play partners. The seven Chinese golf destinations had different perceived characteristics and relationships with South Korean society. Thus, they had dissimilar destination images for Korean golf tourists. Historical ties and geographical proximity played important roles, including, for example, the significant presence of ethnic Koreans in northeast China.

  10. WORK AND POWER ANALYSIS OF THE GOLF SWING

    Directory of Open Access Journals (Sweden)

    Steven M. Nesbit

    2005-12-01

    Full Text Available A work and power (energy analysis of the golf swing is presented as a method for evaluating the mechanics of the golf swing. Two computer models were used to estimate the energy production, transfers, and conversions within the body and the golf club by employing standard methods of mechanics to calculate work of forces and torques, kinetic energies, strain energies, and power during the golf swing. A detailed model of the golf club determined the energy transfers and conversions within the club during the downswing. A full-body computer model of the golfer determined the internal work produced at the body joints during the downswing. Four diverse amateur subjects were analyzed and compared using these two models. The energy approach yielded new information on swing mechanics, determined the force and torque components that accelerated the club, illustrated which segments of the body produced work, determined the timing of internal work generation, measured swing efficiencies, calculated shaft energy storage and release, and proved that forces and range of motion were equally important in developing club head velocity. A more comprehensive description of the downswing emerged from information derived from an energy based analysis

  11. Reuse of reclaimed wastewater for golf course irrigation in Tunisia.

    Science.gov (United States)

    Bahri, A; Basset, C; Oueslati, F; Brissaud, F

    2001-01-01

    In Tunisia, golf courses are irrigated with secondary treated effluent stored in landscape impoundments. The impact of the conveyance and storage steps on the physical-chemical and biological quality of irrigation water was evaluated on three golf courses over two years. It was found that the water quality varies all along the water route, from the wastewater treatment plant up to the irrigation site: nutrient and bacteria contents decreased along the route in the three cases. This variation depends on the wastewater quality, the length of the pipes conveying water, the number of regulation reservoirs and ponds, the water residence time in pipes, reservoirs and ponds, and the operation of the ponds. The bacteriological quality of irrigation water deteriorates during the irrigation period in the three golf courses as the ponds are operated as continuous flow reactors. The results obtained in this study indicate the inability of golf water supplies, as currently managed, to properly sanitize reclaimed wastewater and meet target quality criteria recommended by WHO (1989) for water intended for recreational use. For a safe reuse of reclaimed wastewater for golf course irrigation, changes in the design and operation of the ponds should be planned or additional treatment steps provided.

  12. Golf Blue-e-Motion. The electric Volkswagen; Golf Blue-e-Motion. Der elektrische Volkswagen

    Energy Technology Data Exchange (ETDEWEB)

    Hadler, Jens; Neusser, Heinz-Jakob; Jelden, Hanno; Lueck, Peter; Tousen, Jonas [Volkswagen AG, Wolfsburg (Germany)

    2012-11-01

    The particular challenges of our time require a consistent focus on the development activities of powertrain technologies with continuously reduced fuel consumption and CO2 emissions. The past years have seen many technological milestones by Volkswagen's Powertrain Development as illustrated by the exceptional success of the TSI and TDI engines as well as the double clutch transmissions. As a part of this comprehensive list of powertrain strategy, the development of drivetrains for alternative fuels, such as CNG, has also been included. With particular emphasis Volkswagen is pressing forward the electrification of the drivetrain with the goal of appealing to more customers through these new technologies. A milestone of the electrification activity is the Golf Blue-e-Motion, in which the comfort and especially the city driving performance are improved compared with the conventional vehicle. This driving performance is achieved by an electric drivetrain which consists of a permanent magnet synchronous electric motor together with associated power electronics and a Li-Ion battery. This presentation will pay particular attention to the characteristics of the drivetrain system and its components. The efficient powertrain including the recovering of braking energy (recuperation) as well as the attention paid on optimising all system components, has increased the driving range of the vehicle. Environmental awareness and driving pleasure - the electric drivetrain of the Golf Blue-e-Motion shows that these both requirements are possible to be realised by an electric drivetrain. (orig.)

  13. BLEACHING NEPTUNE BALLS

    Directory of Open Access Journals (Sweden)

    BONET Maria Angeles

    2014-05-01

    Full Text Available Posidonia Oceanic is a seaweed from Mediterranean Sea and it is more concentrated at the Balerian SEA. This implies the Valencian Community also. It forms vaste underwater meadows in the sea and are part of the Mediterranean ecosystem. It is a sea-grass specie with fruits and flowers. Leaves are ribbon-like and they grow in winter and at the end of summer some of them are separated and arrive to some sea line. Fuit is separated and can floate, it is known as “the olive of the sea” mainly in Italy, or as the Neptune Balls. As it can be used in different fields, it is is being studied in order ro have the precitice tests. Some authors have reported the manufacturing of fully bio-based comites with a gluten matrix by hot-press molding. And it has been considered as an effective insulator for building industry or even though to determine the presence of mercure in the Mediterranean sea some years ago. As many applications can be designed from that fibers, it has been considered to be bleached in order to used them in fashionable products. Consequently, its original brown color is not the most suitable one and it should be bleached as many other cellulosic fibers. The aim of this paper is to bleache neptune balls however, the inner fibers were not accessible at all and it implied not to bleach the inner fibers in the neptune ball. Further studiesd will consider bleaching the individualized fibers.

  14. Verbal-motor attention-focusing instructions influence kinematics and performance on a golf-putting task.

    Science.gov (United States)

    Munzert, Jörn; Maurer, Heiko; Reiser, Mathias

    2014-01-01

    The authors examined how varying the content of verbal-motor instructions and requesting an internal versus external focus influenced the kinematics and outcome of a golf putting task. On Day 1, 30 novices performed 120 trials with the instruction to focus attention either on performing a pendulum-like movement (internal) or on the desired ball path (external). After 20 retention trials on Day 2, they performed 20 transfer trials with the opposite instruction. Group differences for retention and a group by block interaction showed that external instruction enhanced movement outcome. Kinematic data indicated that specific instruction content influenced outcomes by eliciting changes in movement execution. Switching from the external to the internal focus instruction resulted in a more pendulum-like movement.

  15. Dynamics of a Bouncing Ball

    Science.gov (United States)

    Liang, Shiuan-Ni; Lan, Boon Leong

    The dynamics of a bouncing ball undergoing repeated inelastic impacts with a table oscillating vertically in a sinusoidal fashion is studied using Newtonian mechanics and general relativistic mechanics. An exact mapping describes the bouncing ball dynamics in each theory. We show, contrary to expectation, that the trajectories predicted by Newtonian mechanics and general relativistic mechanics from the same parameters and initial conditions for the ball bouncing at low speed in a weak gravitational field can rapidly disagree completely. The bouncing ball system could be realized experimentally to test which of the two different predicted trajectories is correct.

  16. Individual ball possession in soccer.

    Directory of Open Access Journals (Sweden)

    Daniel Link

    Full Text Available This paper describes models for detecting individual and team ball possession in soccer based on position data. The types of ball possession are classified as Individual Ball Possession (IBC, Individual Ball Action (IBA, Individual Ball Control (IBC, Team Ball Possession (TBP, Team Ball Control (TBC und Team Playmaking (TPM according to different starting points and endpoints and the type of ball control involved. The machine learning approach used is able to determine how long the ball spends in the sphere of influence of a player based on the distance between the players and the ball together with their direction of motion, speed and the acceleration of the ball. The degree of ball control exhibited during this phase is classified based on the spatio-temporal configuration of the player controlling the ball, the ball itself and opposing players using a Bayesian network. The evaluation and application of this approach uses data from 60 matches in the German Bundesliga season of 2013/14, including 69,667 IBA intervals. The identification rate was F = .88 for IBA and F = .83 for IBP, and the classification rate for IBC was κ = .67. Match analysis showed the following mean values per match: TBP 56:04 ± 5:12 min, TPM 50:01 ± 7:05 min and TBC 17:49 ± 8:13 min. There were 836 ± 424 IBC intervals per match and their number was significantly reduced by -5.1% from the 1st to 2nd half. The analysis of ball possession at the player level indicates shortest accumulated IBC times for the central forwards (0:49 ± 0:43 min and the longest for goalkeepers (1:38 ± 0:58 min, central defenders (1:38 ± 1:09 min and central midfielders (1:27 ± 1:08 min. The results could improve performance analysis in soccer, help to detect match events automatically, and allow discernment of higher value tactical structures, which is based on individual ball possession.

  17. Export of nutrients from golf courses on the Precambrian Shield

    International Nuclear Information System (INIS)

    Winter, Jennifer G.; Dillon, Peter J.

    2006-01-01

    Annual export rates, or fluxes, of total nitrogen (TN), nitrate, total phosphorus (TP) and potassium from four streams on two golf courses on the Precambrian Shield were compared with those from forested reference locations. Overall, the mean annual fluxes of K, TN, NO 3 and TP from golf courses were greater than from forested areas by 10, 2, 6 and 2 times, respectively. The overall mean export coefficients (kg/ha/yr) were 16 for K, 5.2 for TN, 2.1 for NO 3 and 0.14 for TP. For TN and TP, these are similar to those reported from cropland in Canada by Chambers and Dale (1997. Contribution of industrial, municipal, agricultural and groundwater sources to nutrient export, Athabasca, Wapiti and Smoky Rivers, 1980 to 1993. Northern River Basins Study Project Report No. 110. Northern River Basins Study, Edmonton, Alberta). -- Golf courses increase nutrient loads in receiving streams

  18. KARAKTERISTIK KOMUNITAS NEMATODA DI PADANG GOLF SUKARAME (PGS BANDAR LAMPUNG

    Directory of Open Access Journals (Sweden)

    I Gede Swibawa dan Titik Nur Aeny .

    2012-02-01

    Full Text Available ABSTRACT Characteristic of  Nematodes Community at PGS Golf Course Bandar Lampung. Golf course is a unique ecosystem where plant parasitic nematodes inhabit and become  important pest because they reduce the quality of the grass.  The pest problems on golf course can be indicated by its characteristics of nematode community.  Survey on nematodes community at PGS Golf Course Bandar Lampung was conducted from March to December 2004.  The objective was to study the characteristics of nematode community in the part of golf courses hole (green, collar, apron, and fairway.  Soil samples were taken from five holes each of it consists of green, collar, apron, and fairway, respectiveley.  Nematodes extraction was done in Laboratory of Arthropod Pest, Department of Plant Protection University of Lampung.   The result showed that at least 50 nematodes genera of 28 families inhabit PGS. The number of plant parasitic nematode genera was higher than the free-living one.  The characteristic of nematodes community on green and collar was different than on faiway. Nematode abundance and diversity on green and collar were higher than on fairway.  Based on abundance of nematode feeding group, maturity index of free-living nematodes (MI and that of plant parasitic nematodes (PPI, green and collar part seemed to be more favorable to plant parasitic nematodes than free-living nematodes. The contrary happened for fairway.  Four most dominant genera of plant parasitic nematodes on PGS golf course were Helicotylenchus, Hoplolaimus, Criconemella, and Xiphinema.

  19. Energy expenditure and sex differences of golf playing.

    Science.gov (United States)

    Zunzer, Stefan C; von Duvillard, Serge P; Tschakert, Gerhard; Mangus, Brent; Hofmann, Peter

    2013-01-01

    The purpose of the study was to assess the average physical intensity and energy expenditure during a single round of golf on hilly and flat courses in a heterogeneous group of healthy men and women of varying age and golf handicap. Forty-two males and 24 females completed an incremental cycle-ergometer exercise test to determine exercise performance markers. The heart rate (HR), duration, distance, walking speed, ascent and descent were measured via a global positioning system (GPS)/HR monitor during the game and energy expenditure was calculated. Playing 9 or 18-holes of golf, independent of the golf course design, the average HR was not significantly different between sexes or the subgroups. The intensities were light with respect to the percentage of maximal HR and metabolic equivalents of task (METs). Total energy expenditure of all participants was not significantly different for hilly (834 ± 344 kcal) vs. flat courses (833 ± 295 kcal) whereas male players expended significantly greater energy than female players (926 ± 292 vs. 556 ± 180 kcal), but did not have significantly greater relative energy expenditure (2.8 ± 0.8 vs. 2.2 ± 0.7 METs). As a high volume physical activity, playing golf is suggested to yield health benefits. Since the intensity was well below recommended limits, golf may have health related benefits unrelated to the intensity level of the activity.

  20. A comparative study of golf industry between Yangtze River Delta, China and Central Japan

    Science.gov (United States)

    Yang, Yangfan; Jin, Pingbin; Gong, Huiwen

    2018-03-01

    As a competition event of the 2016 Olympic Game, golf sport has aroused great attention around the world. And the Yangtze River Delta(YRD) in China, has already got certain basis and qualifications of developing golf industry, but somehow far from meeting the great potential demand of the market. This research selects the Yangtze River Delta (YRD) and Central Japan (CJ), which are indifferent golf developing stages, as the objectives. Comparative studies are being carried out with an aim of revealing the discrepancies of golf industry in selected regions. The correlations between golf industry and regional economic developing level have been explored as well. Mainly based on a geographical perspective, this research presents an initial effort to combine approaches of setting comparative indexes and spatial analysis, so that golf industry of selected regions will be compared in all directions. The results reveal that great gaps exist in YRD and CJ in terms of golf construction, service, and golf consumption. Problems in developing golf industry in YRD are identified based on the empirical results. A long-term golf development in YRD that deviating from the realistic demand is attributed to both government policies and the operational principles that the market subjects hold. Based on a comparative empirical study, suggestions relating to the government as well as the market players are put forward, with an aim of guiding the golf industry to develop in a sustainable way.

  1. Experimental research on ball lightning

    International Nuclear Information System (INIS)

    Ofuruton, H.; Ohtsuki, Y.H.

    1990-01-01

    Experiments on producing ball lightning were made with discharge in flammable gas and/or aerosol. A long lifetime (2 s) ball lightning was observed in 2.7 % ethane and 100 cm 3 cotton fibers, and in 1.5 % methane and 1.9 % ethane

  2. Crystal Ball at PEP

    International Nuclear Information System (INIS)

    Bartel, W.; Bulos, F.; Luke, D.; Peck, C.; Strauch, K.

    1975-01-01

    The modifications to the SPEAR version of the Crystal Ball required by the higher energies at PEP are discussed. Since the hadron multiplicity is expected to rise as log s, their average energy must rise. On the other hand, if the hadrons are produced in jets, the low energy part of their spectrum is not heavily depleted. This implies that modifications for high energy particles should not deteriorate low energy performance. An external iron calorimeter for measuring the high energy hadrons, charged and neutral, is considered. To improve the angular resolution on γ's, an active internal converter has been studied, estimates have been made of its expected performance, and difficulties requiring further study have been outlined

  3. Cost Benefit Analysis of the Monterey Pines Golf Course

    National Research Council Canada - National Science Library

    Zielinski, Matthew

    2000-01-01

    ..., the government-operated course in the Monterey area. The main purpose of this thesis is to examine the costs and benefits of having a government-operated course in Monterey, where the golf market is extremely competitive, and to examine alternatives...

  4. Estonian Golf & Country Club / Liina Jänes

    Index Scriptorium Estoniae

    Jänes, Liina, 1977-

    2005-01-01

    Estonian Golf & Country Club'i etnomodernistlik golfikeskus ja klubihoone Jõelähtmel. Projekteerija: Arhitektuuristuudio Siim & Kreis. Autor Andres Siim. Konstruktor: Resand. Sisekujundaja Juta Lember (SAB Lember & Padar). Projekt 2004, valmis 2005. Ill.: I ja II korruse plaan, 3 värv. välis ja 3 sisevaadet

  5. Estonian Golf & Country Clubi klubihoone / Andres Siim, Alar Just

    Index Scriptorium Estoniae

    Siim, Andres

    2005-01-01

    Harjumaal Jõelähtme vallas rajab Estonian Golf & Country Club uut Jägala-Jõesuu spordi- ja puhkekeskust, mille südameks saab puidust golgiklubi hoone, mida tutvustavad klubihoone arhitekt ja üks inseneridest. Ill.: vaade ehitusele, projekti kaks vaadet, lõige

  6. Acrchery-Golf Guide. June 1974-June 1976.

    Science.gov (United States)

    Shick, Jacqueline, Ed.; Hague, Andrea, Ed.

    This guide is a collection of essays by various authors on archery and golf. There is a separate section for each sport. In the archery section, the topics covered include archery coaching, aiming, the spine of the arrow, do-it-yourself ideas for archery instruction, archery visual aids, and official rules for various archery activities. The…

  7. Effects of Terrestrial Buffer Zones on Amphibians on Golf Courses

    Science.gov (United States)

    Puglis, Holly J.; Boone, Michelle D.

    2012-01-01

    A major cause of amphibian declines worldwide is habitat destruction or alteration. Public green spaces, such as golf courses and parks, could serve as safe havens to curb the effects of habitat loss if managed in ways to bolster local amphibian communities. We reared larval Blanchard's cricket frogs (Acris blanchardi) and green frogs (Rana clamitans) in golf course ponds with and without 1 m terrestrial buffer zones, and released marked cricket frog metamorphs at the golf course ponds they were reared in. Larval survival of both species was affected by the presence of a buffer zone, with increased survival for cricket frogs and decreased survival for green frogs when reared in ponds with buffer zones. No marked cricket frog juveniles were recovered at any golf course pond in the following year, suggesting that most animals died or migrated. In a separate study, we released cricket frogs in a terrestrial pen and allowed them to choose between mown and unmown grass. Cricket frogs had a greater probability of using unmown versus mown grass. Our results suggest that incorporating buffer zones around ponds can offer suitable habitat for some amphibian species and can improve the quality of the aquatic environment for some sensitive local amphibians. PMID:22761833

  8. The variable and chaotic nature of professional golf performance.

    Science.gov (United States)

    Stöckl, Michael; Lamb, Peter F

    2018-05-01

    In golf, unlike most other sports, individual performance is not the result of direct interactions between players. Instead decision-making and performance is influenced by numerous constraining factors affecting each shot. This study looked at the performance of PGA TOUR golfers in 2011 in terms of stability and variability on a shot-by-shot basis. Stability and variability were assessed using Recurrence Quantification Analysis (RQA) and standard deviation, respectively. About 10% of all shots comprised short stable phases of performance (3.7 ± 1.1 shots per stable phase). Stable phases tended to consist of shots of typical performance, rather than poor or exceptional shots; this finding was consistent for all shot categories. Overall, stability measures were not correlated with tournament performance. Variability across all shots was not related to tournament performance; however, variability in tee shots and short approach shots was higher than for other shot categories. Furthermore, tee shot variability was related to tournament standing: decreased variability was associated with better tournament ranking. The findings in this study showed that PGA TOUR golf performance is chaotic. Further research on amateur golf performance is required to determine whether the structure of amateur golf performance is universal.

  9. Electromyography variables during the golf swing: a literature review.

    Science.gov (United States)

    Marta, Sérgio; Silva, Luís; Castro, Maria António; Pezarat-Correia, Pedro; Cabri, Jan

    2012-12-01

    The aim of the study was to review systematically the literature available on electromyographic (EMG) variables of the golf swing. From the 19 studies found, a high variety of EMG methodologies were reported. With respect to EMG intensity, the right erector spinae seems to be highly activated, especially during the acceleration phase, whereas the oblique abdominal muscles showed moderate to low levels of activation. The pectoralis major, subscapularis and latissimus dorsi muscles of both sides showed their peak activity during the acceleration phase. High muscle activity was found in the forearm muscles, especially in the wrist flexor muscles demonstrating activity levels above the maximal voluntary contraction. In the lower limb higher muscle activity of the trail side was found. There is no consensus on the influence of the golf club used on the neuromuscular patterns described. Furthermore, there is a lack of studies on average golf players, since most studies were executed on professional or low handicap golfers. Further EMG studies are needed, especially on lower limb muscles, to describe golf swing muscle activation patterns and to evaluate timing parameters to characterize neuromuscular patterns responsible for an efficient movement with lowest risk for injury. Copyright © 2012 Elsevier Ltd. All rights reserved.

  10. Age, psychological skills, and golf performance: a prospective investigation.

    Science.gov (United States)

    Hayslip, Bert; Petrie, Trent A

    2014-03-01

    This study explored the influence of age in understanding mental skills utilization in the context of performance at a major national golf competition. Participants, who ranged in age and in skill level, included 1150 male and 170 female amateur golfers competing in the Dupont World Amateur Golf Championship in Myrtle Beach, South Carolina. Measures targeted general mental skills used in competitions, golf-specific skills, and competitive trait anxiety. Hierarchical linear regression was utilized to explore the potential moderating role that chronological age may play in influencing the impact of psychological skills and anxiety on competitive tournament performance across the adult life span. Findings suggested no significant age-moderating effects and instead pointed to the importance of developing golf-specific psychological skills to enhance or maintain performance, irrespective of age. Although automaticity (performance feels "automatic") predicted performance for all golfers, commitment to the game and confidence in one's putting did so only for the men. These findings reinforce the age-irrelevant role of such skills in fostering the experience of peak performance in a competitive sport context and underscore the importance of interventions targeting older players to help maintain or facilitate the use of psychological skills in helping them manage their games.

  11. [Application of near-infrared spectroscopy in golf turfgrass management].

    Science.gov (United States)

    Li, Shu-Ying; Han, Jian-Guo

    2008-07-01

    The management of golf course is different from other turfs. Its particularity lies in its higher and more precise requirement during maintenance compare with other turfs. In case something happened to turf of golf course, more effective and higher speed detecting and resolution are required. Only the data about turf growth and environment were mastered precisely in time, the friendly environmental and scientific management goal could be completed effectively and economically. The near infrared spectroscopy is a new kind of effective, convenient and non-destructive analytical method in the turfgrass management of golf course in recent years. Many factors of turf-soil system in golf course could be determined by near infrared spectroscopy at the same time. In this paper, the existing literature that use of near infrared spectroscopy to study turfgrass and soil nutrient content, soil hygroscopic moisture, feasible fertilizer application time and rate, to fix the time and volume of irrigation, turfgrass visual quality evaluation, turfgrass disease prediction and prevention were reviewed. Most researchers considered the nutrition condition of turf impacted the visual and playing quality of golf course directly and then indirectly influenced most of assistant cultivation such as fertilization, mowing and irrigation and so on. The using of NIRS can detect the nutrient content of turfgrass effectively and estimate the nutrient is excessive or deficient quickly. And then the feasible time and rate of fertilizers can be decided. Comparing with the common judgment ways based on the season fertilization and visual estimation, the using of NIRS can reduce the application of fertilizers on the base of keeping the same turf quality simultaneously. NIRS can analysis many items of soil such as moisture, elements concentration, textures on the spot by the thousands. This method can get lots of cover-all data non-destructively. What's more, NIRS can analysis soil betimes quickly

  12. Hazardous materials on golf courses: Experience and knowledge of golf course superintendents and grounds maintenance workers from seven states

    Science.gov (United States)

    Arcury-Quandt, Alice E.; Gentry, Amanda L.; Marín, Antonio J.

    2011-01-01

    Background The golf course industry has a growing Latino work force. Little occupational health research has addressed this work force. This paper examines golf course superintendents’ and Latino grounds maintenance workers’ pesticide knowledge, beliefs, and safety training. In particular, it focuses on knowledge of and adherence to OSHA Right-to-Know regulations. Methods In person, in-depth interviews were conducted with ten golf course superintendents in five states and with sixteen Latino grounds maintenance workers in four states. Results Few superintendents were in compliance with Right-to-Know regulations or did pesticide safety training with all of their workers. Few workers had any pesticide safety knowledge. Most safety training on golf courses was rudimentary and focused on machine safety, and was usually conducted in the off-season or on rainy days, not before workers were assigned tasks. Conclusions More Right-to-Know training is necessary for superintendents and grounds maintenance workers. Culturally and linguistically appropriate Spanish language materials need to be developed or made more widely available to train workers. Better enforcement of safety and training regulations is necessary. PMID:21360723

  13. Are inertial forces ever of significance in cricket, golf and other sports?

    Science.gov (United States)

    Robinson, Garry; Robinson, Ian

    2017-04-01

    In previous papers we investigated the motion of a spherical projectile rotating about an arbitrary axis, subject to a drag force, a lift or Magnus force, and in the presence of a wind. The aim was to determine the motion of balls used in sporting games, primarily cricket. Newton’s laws of motion apply in an inertial (unaccelerated) coordinate system, but the rotating Earth is not an inertial system. In such a non-inertial system two additional forces are present, the Coriolis force which produces a side-ways movement, and the centrifugal force. Generally these two inertial forces produce noticeable effects only on the large scale, when either the time of travel and/or the path length is large. In this paper we have added both of these forces to the equations of motion. In addition, we have also included a ground friction force in order to simulate a ball rolling over a surface or, more generally, a body moving through a resistive medium such as water. Here we quantitatively investigate the magnitude and direction of the effect of the inertial forces in a number of cases. It is found that, as expected, the effects of the inertial forces are generally small for ball games. In cricket the side-ways movement is ≲1 cm for a throw from the boundary and ≲1 mm for a slow bowler’s delivery, and for a long drive in golf it is ≲10 cm. In lawn bowls the side-ways movement can be ∼2.8 cm, which may be significant, given the nature of this sport. The inertial forces are also potentially of relevance in sporting events not employing spherical projectiles. For example, in Olympic rowing we find that the side-ways movement can be more than 40 m for a 2 km race if it is not compensated for, and nearly 20 m for a 4 min mile event in athletics. The effect is also of significance in events such as swimming and horse racing. The importance of this is that athletes may not be aware of the effect and, in the case of rowing for example, may attribute it to side-ways currents

  14. LHC gets the ball rolling

    CERN Multimedia

    2007-01-01

    A technique involving a small ball with a transmitter embedded inside it has been successfully tested in Sector 7-8. The ball is sent through the LHC beam pipes to check the LHC interconnections. The multidisciplinary team responsible for the RF ball project to check the interconnections. From left to right: Rhodri Jones (AB/BI), Eva Calvo (AB/BI), Francesco Bertinelli (AT/MCS), Sonia Bartolome Jimenez (TS/IC), Sylvain Weisz (TS/IC), Paul Cruikshank (AT/VAC), Willemjan Maan (AT/VAC), Alain Poncet (AT/MCS), Marek Gasior (AB/BI). During the tests the ball is inserted very carefully into the vacuum chamber.A game of ping-pong at the LHC? On 13 September a rather unusual test was carried out in Sector 7-8 of the accelerator. A ball just a bit smaller than a ping-pong ball was carefully introduced into one of the accelerator’s two vacuum pipes, where it travelled 800 metres in the space of a few mi...

  15. Golf cart prototype development and navigation simulation using ROS and Gazebo

    Directory of Open Access Journals (Sweden)

    Shimchik Ilya

    2016-01-01

    Full Text Available This paper presents our approach to development of an autonomous golf cart, which will navigate in inaccessible by regular vehicles private areas. For this purpose, we have built a virtual golf course terrain and golf cart model in Gazebo, selected and modernized ROS-based packages in order to use them with Ackermann steering vehicle simulation. To verify our simulation and algorithms, we navigated the golf cart model from one golf hole to another within a virtual 3D golf course. For the real world algorithms’ verification, we developed a small-size vehicle prototype based on Traxxas radio-controlled car model, which is equipped with an on-board controller and sensors. The autonomous navigation of Traxxas-based vehicle prototype has been tested in indoor environment, where it utilized sensory data about environment and vehicle states, and performed localization, optimal trajectory computation and dynamic obstacles’ recognition with adjusting the route in real time.

  16. Morbidity associated with golf-related injuries among children: findings from a pediatric trauma center.

    Science.gov (United States)

    Vitale, Melissa A; Mertz, Kristen J; Gaines, Barbara; Zuckerbraun, Noel S

    2011-01-01

    To describe injuries due to golf-related activities among pediatric patients requiring hospital admission. We conducted a retrospective analysis of all sports-related injuries from 2000 to 2006 using a level 1 trauma center database. Of 1005 children admitted with sports-related injuries, 60 (6%) had golf-related injuries. The mean injury severity score was significantly higher for golf-related injuries (11.0) than that for all other sports-related injuries (6.8). Most golf-related injuries occurred in children younger than 12 years (80%), at home (48%), and by a strike from a club (57%) and resulted in trauma to the head or neck (68%). Golf-related injuries, although an infrequent cause of sports-related injuries, have the potential to result in severe injuries, especially in younger children. Preventive efforts should target use of golf clubs by younger children in the home setting.

  17. Effect of Putting Grip on Eye and Head Movements During the Golf Putting Stroke

    Directory of Open Access Journals (Sweden)

    George K. Hung

    2003-01-01

    Full Text Available The objective of this article is to determine the effect of three different putting grips (conventional, cross-hand, and one-handed on variations in eye and head movements during the putting stroke. Seven volunteer novice players, ranging in age from 21 to 22 years, participated in the study. During each experimental session, the subject stood on a specially designed platform covered with artificial turf and putted golf balls towards a standard golf hole. The three different types of grips were tested at two distances: 3 and 9 ft. For each condition, 20 putts were attempted. For each putt, data were recorded over a 3-s interval at a sampling rate of 100 Hz. Eye movements were recorded using a helmet-mounted eye movement monitor. Head rotation about an imaginary axis through the top of the head and its center-of-rotation was measured by means of a potentiometer mounted on a fixed frame and coupled to the helmet. Putter-head motion was measured using a linear array of infrared phototransistors embedded in the platform. The standard deviation (STD, relative to the initial level was calculated for eye and head movements over the duration of the putt (i.e., from the beginning of the backstroke, through the forward stroke, to impact. The averaged STD for the attempted putts was calculated for each subject. Then, the averaged STDs and other data for the seven subjects were statistically compared across the three grip conditions. The STD of eye movements were greater (p < 0.1 for conventional than cross-hand (9 ft and one-handed (3 and 9 ft grips. Also, the STD of head movements were greater (p < 0.1; 3 ft for conventional than cross-hand and one-handed grips. Vestibulo-ocular responses associated with head rotations could be observed in many 9 ft and some 3 ft putts. The duration of the putt was significantly longer (p < 0.05; 3 and 9 ft for the one-handed than conventional and cross-hand grips. Finally, performance, or percentage putts made, was

  18. Efeitos do contínuo de níveis de interferência contextual na aprendizagem do "putt" do golfe Effects of a contextual interference continuum on golf putting task

    Directory of Open Access Journals (Sweden)

    Gonçalo Dias

    2010-12-01

    experiment. During the acquisition they putted 126 trails from three distances (2, 2.75 and 3.5 meters for the same golf hole target. In retention test they performed 30 trials in a random order. In the transfer test the subjects performed 20 trials: 10 at 2.5 meters and 10 to 2.5 meters with 10 degrees of deviation from the starting point towards the hole. The apparatus of this study consisted of one artificial putting indoor golf carpet. All participants putt the same golf ball with the same right-handed putter. The data of retention and transfer tests were analyzed using separate one-way ANOVAs. Although it is observed in the absolute error a trend of superiority of performance of the group or increasing CI practice schedule on transfer test, the analysis didn't reveal a significant main effect for practice conditions. The effect of increasing CI was not found in this experiment.

  19. Simulation and Test of a Fuel Cell Hybrid Golf Cart

    Directory of Open Access Journals (Sweden)

    Jingming Liang

    2014-01-01

    Full Text Available This paper establishes the simulation model of fuel cell hybrid golf cart (FCHGC, which applies the non-GUI mode of the Advanced Vehicle Simulator (ADVISOR and the genetic algorithm (GA to optimize it. Simulation of the objective function is composed of fuel consumption and vehicle dynamic performance; the variables are the fuel cell stack power sizes and the battery numbers. By means of simulation, the optimal parameters of vehicle power unit, fuel cell stack, and battery pack are worked out. On this basis, GUI mode of ADVISOR is used to select the rated power of vehicle motor. In line with simulation parameters, an electrical golf cart is refitted by adding a 2 kW hydrogen air proton exchange membrane fuel cell (PEMFC stack system and test the FCHGC. The result shows that the simulation data is effective but it needs improving compared with that of the real cart test.

  20. Suppressing Heavy Metal Leaching through Ball Milling of Fly Ash

    Directory of Open Access Journals (Sweden)

    Zhiliang Chen

    2016-07-01

    Full Text Available Ball milling is investigated as a method of reducing the leaching concentration (often termed stablilization of heavy metals in municipal solid waste incineration (MSWI fly ash. Three heavy metals (Cu, Cr, Pb loose much of their solubility in leachate by treating fly ash in a planetary ball mill, in which collisions between balls and fly ash drive various physical processes, as well as chemical reactions. The efficiency of stabilization is evaluated by analysing heavy metals in the leachable fraction from treated fly ash. Ball milling reduces the leaching concentration of Cu, Cr, and Pb, and water washing effectively promotes stabilization efficiency by removing soluble salts. Size distribution and morphology of particles were analysed by laser particle diameter analysis and scanning electron microscopy. X-ray diffraction analysis reveals significant reduction of the crystallinity of fly ash by milling. Fly ash particles can be activated through this ball milling, leading to a significant decrease in particle size, a rise in its BET-surface, and turning basic crystals therein into amorphous structures. The dissolution rate of acid buffering materials present in activated particles is enhanced, resulting in a rising pH value of the leachate, reducing the leaching out of some heavy metals.

  1. The role of anxiety in golf putting performance

    OpenAIRE

    Kenny, Ian; MacNamara, Aine; Shafat, Amir; Dunphy, Orla; Murphy, Sinead; O'Connor, Kenneth; Ryan, Tara; Waldron, Gerry

    2009-01-01

    peer-reviewed INTRODUCTION: Anxiety???s influence on performance continues to be one of the main research interests for sport psychologists (Hanin, 2000). It is apparent, though, that there is a lack of empirical research characterising the multi-disciplinary effect of anxiety on sports performance. The current study aimed to ascertain biomechanical (accuracy, movement variability) and psychological (anxiety) markers to determine how anxiety affects golf putting. METHOD: 22 healthy s...

  2. Epidemiology of golf related musculo-skeletal injuries

    Directory of Open Access Journals (Sweden)

    Dhillon Mandeep

    2006-01-01

    Full Text Available Background : Golfing has become an increasingly popular sport enjoyed by both men and women. Although the game is not viewed as hazardous, golfers do sustain injuries connected with the game. However, golf injuries have received little attention in the literature and there is no study from Asia. Methods : A prospective study was undertaken to analyze the incidence, cause and type of injury among amateur golfers. Open ended questionnaires were sent to 1000 golfers; 240 responded (Av age 51 years, 200 males and 40 females. The respondents played an average of 2 rounds per week. Results : One hundered and ten (46% responders had sustained one or more orthopaedic injuries. Both among men and women, the lower back was the most common site of injury followed by shoulder and dorsal spine. There was a difference in the injury pattern in skilled and relatively unskilled players. Lack of warm up, excessive practice and improper swing mechanics were the most common causes. Conclusion : Golf injuries perhaps could be prevented or reduced by proper technique, controlled practice routines, physical conditioning and pre-play stretching exercises. The most important factor in this playing population seems to be prevention.

  3. Brain networks governing the golf swing in professional golfers.

    Science.gov (United States)

    Kim, Jin Hyun; Han, Joung Kyue; Kim, Bung-Nyun; Han, Doug Hyun

    2015-01-01

    Golf, as with most complex motor skills, requires multiple different brain functions, including attention, motor planning, coordination, calculation of timing, and emotional control. In this study we assessed the correlation between swing components and brain connectivity from the cerebellum to the cerebrum. Ten female golf players and 10 age-matched female controls were recruited. In order to determine swing consistency among participants, the standard deviation (SD) of the mean swing speed time and the SD of the mean swing angle were assessed over 30 swings. Functional brain connectivity was assessed by resting state functional MRI. Pro-golfers showed greater positive left cerebellum connectivity to the occipital lobe, temporal lobe, parietal lobe and both frontal lobes compared to controls. The SD of play scores was positively correlated with the SD of the impact angle. Constant swing speed and back swing angle in professional golfers were associated with functional connectivity (FC) between the cerebellum and parietal and frontal lobes. In addition, the constant impact angle in professional golfers was associated with improved golf scores and additional FC of the thalamus.

  4. Motor abundance and control structure in the golf swing.

    Science.gov (United States)

    Morrison, A; McGrath, D; Wallace, E S

    2016-04-01

    Variability and control structure are under-represented areas of golf swing research. This study investigated the use of the abundant degrees of freedom in the golf swing of high and intermediate skilled golfers using uncontrolled manifold (UCM) analysis. The variance parallel to (VUCM) and orthogonal to (VOrth) the UCM with respect to the orientation and location of the clubhead were calculated. The higher skilled golfers had proportionally higher values of VUCM than lower skilled players for all measured outcome variables. Motor synergy was found in the control of the orientation of the clubhead and the combined outcome variables but not for clubhead location. Clubhead location variance zeroed-in on impact as has been previously shown, whereas clubhead orientation variance increased near impact. Both skill levels increased their control over the clubhead location leading up to impact, with more control exerted over the clubhead orientation in the early downswing. The results suggest that to achieve higher skill levels in golf may not lie simply in optimal technique, but may lie more in developing control over the abundant degrees of freedom in the body. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. Thermal Analysis of Ball screw Systems by Explicit Finite Difference Method

    Energy Technology Data Exchange (ETDEWEB)

    Min, Bog Ki [Hanyang Univ., Seoul (Korea, Republic of); Park, Chun Hong; Chung, Sung Chong [KIMM, Daejeon (Korea, Republic of)

    2016-01-15

    Friction generated from balls and grooves incurs temperature rise in the ball screw system. Thermal deformation due to the heat degrades positioning accuracy of the feed drive system. To compensate for the thermal error, accurate prediction of the temperature distribution is required first. In this paper, to predict the temperature distribution according to the rotational speed, solid and hollow cylinders are applied for analysis of the ball screw shaft and nut, respectively. Boundary conditions such as the convective heat transfer coefficient, friction torque, and thermal contact conductance (TCC) between balls and grooves are formulated according to operating and fabrication conditions of the ball screw. Explicit FDM (finite difference method) is studied for development of a temperature prediction simulator. Its effectiveness is verified through numerical analysis.

  6. Evaluation of solar-assisted, electric and gas golf carts, Bathurst Glen golf course, Richmond Hill, Ontario

    International Nuclear Information System (INIS)

    2010-08-01

    Municipalities try to limit air pollution resulting from the use of small gasoline engines. Indeed, these engines participate in the smog and greenhouse gas (GHG) emissions and they present operating costs more important than electric equivalents. The potential positive impacts of the use of electric or solar electric golf carts instead of gasoline carts are analyzed through a study that compares two solar-assisted electric golf carts, two standard electric golf carts and two gas-powered golf carts. The energy use and related Co2 emissions, the dependability, and the relative costs were evaluated and Golfer preference was also considered thanks to a feedback survey. The comparison between the solar-assisted and the standard electric carts was made on the basis of electricity measures at three points: alternating current (AC) electricity taken from the grid, direct current (DC) electricity flowing into and out of the batteries, and DC electricity generated by the solar panels. The data collected during this study suggested that other factors associated with cart condition or driver behaviours can be more important than the solar panels in determining overall energy consumption. Choosing an area with full sun exposure to install the solar panel and connecting directly to the grid would also maximize generation potential. The comparison of performance between electric carts and gas carts showed the most considerable positive findings. Indeed, fuel costs and emissions are significantly lower in the case of the electric carts, which also present a better fuel efficiency. Switching the 20 percent of gas-powered carts counted within a 100 km radius of Toronto with electric carts could be comparable to removing 155 mid-sized gasoline cars of the road. The electric golf carts present many important financial and environmental benefits when compared to gas carts. The performance is marginally enhanced with the use of solar panels on electric carts and the date collected from

  7. IMPROVED MOTOR-TIMING: EFFECTS OF SYNCHRONIZED METRO-NOME TRAINING ON GOLF SHOT ACCURACY

    Directory of Open Access Journals (Sweden)

    Louise Rönnqvist

    2009-12-01

    Full Text Available This study investigates the effect of synchronized metronome training (SMT on motor timing and how this training might affect golf shot accuracy. Twenty-six experienced male golfers participated (mean age 27 years; mean golf handicap 12.6 in this study. Pre- and post-test investigations of golf shots made by three different clubs were conducted by use of a golf simulator. The golfers were randomized into two groups: a SMT group and a Control group. After the pre-test, the golfers in the SMT group completed a 4-week SMT program designed to improve their motor timing, the golfers in the Control group were merely training their golf-swings during the same time period. No differences between the two groups were found from the pre-test outcomes, either for motor timing scores or for golf shot accuracy. However, the post-test results after the 4-weeks SMT showed evident motor timing improvements. Additionally, significant improvements for golf shot accuracy were found for the SMT group and with less variability in their performance. No such improvements were found for the golfers in the Control group. As with previous studies that used a SMT program, this study's results provide further evidence that motor timing can be improved by SMT and that such timing improvement also improves golf accuracy

  8. Nitrous oxide emissions from a golf course fairway and rough following application of different nitrogen fertilizers

    Science.gov (United States)

    Nitrous oxide (N2O) is a potent greenhouse gas that destroys stratospheric ozone. There is limited research of golf course N2O emission and the effects of frequent fertilization and irrigation. Three enhanced efficiency nitrogen fertilizers (EENFs) were applied to a Colorado golf course fairway and ...

  9. Promoting Golf as a Lifetime Physical Activity for Persons with Disabilities

    Science.gov (United States)

    Sandt, Dawn D.; Flynn, Erin; Turner, Tiffany A.

    2014-01-01

    Golf is one of the most accessible and versatile physical activities and is a viable choice for young adults with disabilities to engage in the recommended levels of physical activity. Teaching golf to youth with disabilities requires more than making accommodations regarding equipment, technique, and rules in the physical education setting. For…

  10. ENVIRONMENTAL EFFECTS OF A GOLF COMPLEX ON COASTAL WETLANDS IN THE GULF OF MEXICO

    Science.gov (United States)

    The increasing density of golf courses represents a potential source of contamination to nearby coastal wetlands and other near-shore areas. The chemical and biological magnitude of the problem is almost unknown. To provide perspective on this issue, the effects of golf complex r...

  11. Ground penetrating radar water content mapping of golf course green sand layers

    Science.gov (United States)

    Information on the spatial distribution of water content across the sand layer component of a golf course green can be important to golf course superintendents for evaluating drainage effectiveness and scheduling irrigation. To estimate the bulk water content of the sand layer at point locations ac...

  12. Golf Tournament Drives in a Win for the Children’s Inn | Poster

    Science.gov (United States)

    By Carolynne Keenan, Contributing Writer On September 23, golfers took to the Clustered Spires golf course in Frederick, Md., for a cause. The R&W Club Frederick hosted its inaugural golf tournament, with proceeds benefiting the National Institutes of Health (NIH) Children’s Inn.

  13. Bridging the Generation Gap: "Growing Golf" through an Action Learning Activity

    Science.gov (United States)

    Elbert, Norb; Cumiskey, Kevin J.

    2014-01-01

    This paper describes an action learning simulation designed for a Professional Golf Management (PGM) program housed in a College of Business of a public university. The PGA Golf Management University Program, a 4.5- to 5-year college curriculum for aspiring PGA Professionals is offered at 19 PGA accredited universities nationwide. The program…

  14. Omanikud lõpetavad skandaalse firma Kuressaare Golf tegevuse / Andres Sepp

    Index Scriptorium Estoniae

    Sepp, Andres, 1976-

    2004-01-01

    AS Kuressaare Golf likvideeritakse, sest Põduste jõe äärde kavandatud golfiväljaku ehitamise plaanid sumbusid, kuna firma aktsionäride vahel tekitas tüli rahakantimise kahtlus. Kommenteerib AS-i Kuressaare Golf juhatuse liige Meelis Põlda

  15. Shufflegolf: Teaching Golf Strategies and Etiquette to Young Children and Learners with Intellectual Disabilities

    Science.gov (United States)

    Kozub, Francis M.

    2010-01-01

    The purpose of this article is to share a unique curricular idea with physical educators interested about adding golf concepts to their curriculum. The focus is on a modified golf game that helps teach tactics, strategies, rules, and etiquette to young learners and those with intellectual disabilities. The specific content for this unit focuses on…

  16. Evaluating poverty grass (Danthonia spicata) for golf courses in the Midwest

    Science.gov (United States)

    Nadia E. Navarrete-Tindall; J.W. Van Sambeek

    2010-01-01

    Poverty grass (Danthonia spicata (L.) P. beauv. Ex Roem & Schult. ) results presented here are part of ongoing studies to evaluate its adaptation for golf courses as part of low maintenance natural communities at Lincoln University of Missouri. Because its natural adaptation to shade and poor soils, poverty grass could be established in golf...

  17. A good walk spoiled: on the disappearance of golf as an active sport in America.

    Science.gov (United States)

    Puterbaugh, James S

    2011-07-01

    During the past 60 years, there has been a major transition in the way golf is played in America. Its potential as exercise largely has been negated by the increase in motorized golf cart usage to approximately two of every three rounds played in this country. Accidents in golf carts have increased rapidly, which, by making the sport more dangerous, will likely bring future regulations. Consequently, playing golf has gradually become more of a public health threat than a benefit. The motorized cart also has resulted in an almost doubling of the size of golf courses, which now occupy a large amount of the built environment designated for activity. These changes are a major loss to society, portend future problems, and call for the sport to reevaluate its current model.

  18. LHC gets the ball rolling

    CERN Multimedia

    2007-01-01

    1. The multidisciplinary team responsible for the RF ball project to check the interconnections. From left to right: Rhodri Jones (AB/BI), Eva Calvo (AB/BI), Francesco Bertinelli (AT/MCS), Sonia Bartolome Jimenez (TS/IC), Sylvain Weisz (TS/IC), Paul Cruikshank (AT/VAC), Willemjan Maan (AT/VAC), Alain Poncet (AT/MCS), Marek Gasior (AB/BI).2. During the tests the ball is inserted very carefully into the vacuum chamber.1. Le groupe pluridisciplinaire qui a mené le projet de balle RF pour vérifier les interconnexions avec, de gauche à droite, Rhodri Jones (AB/BI), Eva Calvo (AB/BI), Francesco Bertinelli (AT/MCS), Sonia Bartolome Jimenez (TS/IC), Sylvain Weisz (TS/IC), Paul Cruikshank (AT/VAC), Willemjan Maan (AT/VAC), Alain Poncet (AT/MCS) et Marek Gasior (AB/BI).2. Lors des tests, la balle est insérée dans la chambre à vide avec beaucoup de précaution.

  19. The correct "ball bearings" data.

    Science.gov (United States)

    Caroni, C

    2002-12-01

    The famous data on fatigue failure times of ball bearings have been quoted incorrectly from Lieblein and Zelen's original paper. The correct data include censored values, as well as non-fatigue failures that must be handled appropriately. They could be described by a mixture of Weibull distributions, corresponding to different modes of failure.

  20. Reflections on a Disco Ball

    Science.gov (United States)

    Ribeiro, Jair Lúcio Prados

    2016-01-01

    A disco ball is a spherical object covered with small plane mirrors. When light reflects on these mirrors, it is scattered in many directions, producing a novel effect. The mirror globe is usually set to rotate, creating a profusion of moving spots (Fig. 1). In this article, we present a geometrical description of the movement of these spots and…

  1. Analysis of grease contamination influence on the internal radial clearance of ball bearings by thermographic inspection

    Directory of Open Access Journals (Sweden)

    Mišković Žarko Z.

    2016-01-01

    Full Text Available One of the most important factors influencing ball bearings service life is its internal radial clearance. However, this parameter is also very complex because it depends on applied radial load and ball bearings dimensions, surface finish and manufacturing materials. Thermal condition of ball bearings also significantly affects internal radial clearance. Despite many researches performed in order to find out relevant facts about different aspects of ball bearings thermal behaviour, only few of them are dealing with the real working conditions, where high concentration of solid contaminant particles is present. That’s why the main goal of research presented in this paper was to establish statistically significant correlation between ball bearings temperatures, their working time and concentration of contaminant particles in their grease. Because of especially difficult working conditions, the typical conveyor idlers bearings were selected as representative test samples and appropriate solid particles from open pit coal mines were used as artificial contaminants. Applied experimental methodology included thermographic inspection, as well as usage of custom designed test rig for ball bearings service life testing. Finally, by obtained experimental data processing in advanced software, statistically significant mathematical correlation between mentioned bearings characteristics was determined and applied in commonly used internal radial clearance equation. That is the most important contribution of performed research - the new equation and methodology for ball bearings internal clearance determination which could be used for eventual improvement of existing bearings service life equations. [Projekat Ministarstva nauke Republike Srbije, br. TR35029 i br. TR14033

  2. Encapsulated Ball Bearings for Rotary Micro Machines

    Science.gov (United States)

    2007-01-01

    occurrence as well as the overall tribological properties of the bearing mechanism. Firstly, the number of stainless steel balls influences not only the load...stacks.iop.org/JMM/17/S224 Abstract We report on the first encapsulated rotary ball bearing mechanism using silicon microfabrication and stainless steel balls...The method of capturing stainless steel balls within a silicon race to support a silicon rotor both axially and radially is developed for rotary micro

  3. The "swing-ding": a golf-related head injury in children.

    Science.gov (United States)

    Wang, Arthur; Cohen, Alan R; Robinson, Shenandoah

    2011-01-01

    In recent years there has been an increased incidence of golf-associated head injuries in children and adolescents. At the authors' institution, they have identified a unique pattern of head injury associated with a swinging golf club. In this study, the authors highlight the mechanism of this injury and report their experience treating it. The authors reviewed the database of Rainbow Babies and Children's Hospital Trauma Center and performed a retrospective analysis of golf injuries recorded over a 10-year period (January 2000-April 2010). They identified 13 children (9 boys and 4 girls) who sustained head injuries in golfing accidents. All patients were 10 years of age or younger. The medical charts were reviewed and follow-up interviews were conducted to better delineate the details of the injuries. Injuries included 13 depressed skull fractures, 7 epidural hematomas, and 1 cerebral contusion. All 13 patients sustained their injuries after being struck in the head by a golf club. Seven sustained injuries on the follow-through of the initial swing and 3 sustained injuries on the backswing. All but one patient required neurosurgical intervention. Five patients developed neurological sequelae. None of the children had prior experience with golf equipment. All but one injury occurred in the child's own backyard. There was no direct supervision by an adult in any of the cases. Golfing can lead to serious head injuries in children. The authors noticed a unique pattern of golf-related head injuries, previously not described, that they have termed the "swing-ding." This golf club-inflicted injury occurs when a child stands too close to a swinging golfer and is struck in the head, subsequently sustaining a comminuted depressed skull fracture in the frontal or temporal region, with or without further intracranial injury. The study suggests that a lack of adult supervision, minimal previous golf experience, and proximity of the child to the swinging golfer are all

  4. Ceramic ball grid array package stress analysis

    Science.gov (United States)

    Badri, S. H. B. S.; Aziz, M. H. A.; Ong, N. R.; Sauli, Z.; Alcain, J. B.; Retnasamy, V.

    2017-09-01

    The ball grid array (BGA), a form of chip scale package (CSP), was developed as one of the most advanced surface mount devices, which may be assembled by an ordinary surface ball bumps are used instead of plated nickel and gold (Ni/Au) bumps. Assembly and reliability of the BGA's printed circuit board (PCB), which is soldered by conventional surface mount technology is considered in this study. The Ceramic Ball Grid Array (CBGA) is a rectangular ceramic package or square-shaped that will use the solder ball for external electrical connections instead of leads or wire for connections. The solder balls will be arranged in an array or grid at the bottom of the ceramic package body. In this study, ANSYS software is used to investigate the stress on the package for 2 balls and 4 balls of the CBGA package with the various force range of 1-3 Newton applied to the top of the die, top of the substrate and side of the substrate. The highest maximum stress was analyzed and the maximum equivalent stress was observed on the solder ball and the die. From the simulation result, the CBGA package with less solder balls experience higher stress compared to the package with many solder balls. Therefore, less number of solder ball on the CBGA package results higher stress and critically affect the reliability of the solder balls itself, substrate and die which can lead to the solder crack and also die crack.

  5. Supersymmetric Q-balls theory and cosmology

    CERN Document Server

    Kusenko, A

    1999-01-01

    MSSM predicts the existence of Q-balls, some of which can be entirely stable. Both stable and unstable Q-balls can play an important role in cosmology. In particular, Affleck-Dine baryogenesis can result in a copious production of stable baryonic Q-balls, which can presently exist as a form of dark matter.

  6. Peer pressure and thai amateur golfers' gambling on their games: the mediating effect of golf self-efficacy.

    Science.gov (United States)

    Ariyabuddhiphongs, Vanchai; Promsakha Na Sakolnakorn, Chomnad

    2014-09-01

    Our study hypothesizes that Thai amateur golfers gamble on their game because of peer pressure and their golf self-efficacy. To support our hypothesis, we conducted a study to examine the mediating effect of golf self-efficacy on the peer pressure-golf gambling relationship among 387 amateur golfers in Thailand. Peer pressure was operationally defined as fellow players' influence on the individual golfer to gamble; golf self-efficacy as the judgment of the golfer's skills to play golf; and golf gambling as the frequency and amounts of gambling. Regression analysis with bootstrapping was used to test the mediation effect of golf self-efficacy on the peer pressure-golf gambling relationship. The results support our hypothesis; peer pressure predicted golf gambling, and the indirect effect of peer pressure to golf gambling through the mediation of golf self-efficacy was significant. The results support the influence of peer pressure on gambling, and the social cognitive theory reciprocal relationship model.

  7. Results from the crystal ball detector at SPEAR

    International Nuclear Information System (INIS)

    Bloom, E.D.

    1979-11-01

    The Crystal Ball detector is a device particularly suited to the measurement of photons with energies lower than 1 GeV. The detector has as its principal component a 16 radiation length thick, highly segmented shell of NaI(Tl) surrounding cylindrical, proportional, and magnetostrictive spark chambers. The main Ball and various elements of the central chambers cover 94% of 4π sr. Segmented endcap NaI(Tl) detectors of 20 radiation lengths behind magneto strictive spark chambers supplement the main Ball. The Ball and endcaps close the solid angle for charged particle and photon detection to 98% of 4π sr. In addition, detectors of interspersed iron and proportional tubes provide for μ-π separation over 15% of 4π sr, about theta/sub CM/ = 90 0 . In this report preliminary results are presented from the data obtained. In particular, QED at E/sub CM/ = 6.5 GeV, R/sub hadron/ and related inclusive distributions, eta branching fractions at J/psi and psi'', and a detailed study of the psionium system are discussed

  8. Ball mounting fixture for a roundness gage

    Science.gov (United States)

    Gauler, Allen L.; Pasieka, Donald F.

    1983-01-01

    A ball mounting fixture for a roundness gage is disclosed. The fixture includes a pair of chuck assemblies oriented substantially transversely with respect to one another and mounted on a common base. Each chuck assembly preferably includes a rotary stage and a wobble plate affixed thereto. A ball chuck affixed to each wobble plate is operable to selectively support a ball to be measured for roundness, with the wobble plate permitting the ball chuck to be tilted to center the ball on the axis of rotation of the rotary stage. In a preferred embodiment, each chuck assembly includes a vacuum chuck operable to selectively support the ball to be measured for roundness. The mounting fixture enables a series of roundness measurements to be taken with a conventional rotating gagehead roundness instrument, which measurements can be utilized to determine the sphericity of the ball.

  9. Ceramic Rail-Race Ball Bearings

    Science.gov (United States)

    Balzer, Mark A.; Mungas, Greg S.; Peters, Gregory H.

    2010-01-01

    Non-lubricated ball bearings featuring rail races have been proposed for use in mechanisms that are required to function in the presence of mineral dust particles in very low-pressure, dry environments with extended life. Like a conventional ball bearing, the proposed bearing would include an inner and an outer ring separated by balls in rolling contact with the races. However, unlike a conventional ball bearing, the balls would not roll in semi-circular or gothic arch race grooves in the rings: instead, the races would be shaped to form two or more rails (see figure). During operation, the motion of the balls would push dust particles into the spaces between the rails where the particles could not generate rolling resistance for the balls

  10. Trunk muscle activation during golf swing: Baseline and threshold.

    Science.gov (United States)

    Silva, Luís; Marta, Sérgio; Vaz, João; Fernandes, Orlando; Castro, Maria António; Pezarat-Correia, Pedro

    2013-10-01

    There is a lack of studies regarding EMG temporal analysis during dynamic and complex motor tasks, such as golf swing. The aim of this study is to analyze the EMG onset during the golf swing, by comparing two different threshold methods. Method A threshold was determined using the baseline activity recorded between two maximum voluntary contraction (MVC). Method B threshold was calculated using the mean EMG activity for 1000ms before the 500ms prior to the start of the Backswing. Two different clubs were also studied. Three-way repeated measures ANOVA was used to compare methods, muscles and clubs. Two-way mixed Intraclass Correlation Coefficient (ICC) with absolute agreement was used to determine the methods reliability. Club type usage showed no influence in onset detection. Rectus abdominis (RA) showed the higher agreement between methods. Erector spinae (ES), on the other hand, showed a very low agreement, that might be related to postural activity before the swing. External oblique (EO) is the first being activated, at 1295ms prior impact. There is a similar activation time between right and left muscles sides, although the right EO showed better agreement between methods than left side. Therefore, the algorithms usage is task- and muscle-dependent. Copyright © 2013 Elsevier Ltd. All rights reserved.

  11. Hybrid markerless tracking of complex articulated motion in golf swings.

    Science.gov (United States)

    Fung, Sim Kwoh; Sundaraj, Kenneth; Ahamed, Nizam Uddin; Kiang, Lam Chee; Nadarajah, Sivadev; Sahayadhas, Arun; Ali, Md Asraf; Islam, Md Anamul; Palaniappan, Rajkumar

    2014-04-01

    Sports video tracking is a research topic that has attained increasing attention due to its high commercial potential. A number of sports, including tennis, soccer, gymnastics, running, golf, badminton and cricket have been utilised to display the novel ideas in sports motion tracking. The main challenge associated with this research concerns the extraction of a highly complex articulated motion from a video scene. Our research focuses on the development of a markerless human motion tracking system that tracks the major body parts of an athlete straight from a sports broadcast video. We proposed a hybrid tracking method, which consists of a combination of three algorithms (pyramidal Lucas-Kanade optical flow (LK), normalised correlation-based template matching and background subtraction), to track the golfer's head, body, hands, shoulders, knees and feet during a full swing. We then match, track and map the results onto a 2D articulated human stick model to represent the pose of the golfer over time. Our work was tested using two video broadcasts of a golfer, and we obtained satisfactory results. The current outcomes of this research can play an important role in enhancing the performance of a golfer, provide vital information to sports medicine practitioners by providing technically sound guidance on movements and should assist to diminish the risk of golfing injuries. Copyright © 2013 Elsevier Ltd. All rights reserved.

  12. Amounts of mercury in soil of some golf course sites

    Energy Technology Data Exchange (ETDEWEB)

    MacLean, A J; Stone, B; Cordukes, W E

    1973-01-01

    Mercurial compounds are widely used for controlling diseases of turfgrass of golf courses, but the fungicides are usually confined to the greens. Composite soil samples were obtained from three golf courses in the Ottawa and Ontario region of Canada. Samples from the turf and surface layer of soil were analyzed and high amounts of mercury were found. The soil of No.I course was a sand; No.II was a sandy loam in the surface and a loam below; and No. III was a loam in the surface layer and a clay loam below. The pH of the surface layer was 6.4 in No. I, 7.5 in No. II, and 6.0 in No. III. The amounts of Hg in the turf were high near the green but they decreased with distance. Fairway III contained the highest amounts of Hg and there was evidence of it leaching to a depth of 90 cm at the edge of the green. The particularly high amounts of Hg in no III were in accord with the liberal use of mercurial fungicides on this course in the period 1912-64. The leaching of Hg depends on amounts of organic matter and the clay in the soil.

  13. Suitability of Strain Gage Sensors for Integration into Smart Sport Equipment: A Golf Club Example.

    Science.gov (United States)

    Umek, Anton; Zhang, Yuan; Tomažič, Sašo; Kos, Anton

    2017-04-21

    Wearable devices and smart sport equipment are being increasingly used in amateur and professional sports. Smart sport equipment employs various sensors for detecting its state and actions. The correct choice of the most appropriate sensor(s) is of paramount importance for efficient and successful operation of sport equipment. When integrated into the sport equipment, ideal sensors are unobstructive, and do not change the functionality of the equipment. The article focuses on experiments for identification and selection of sensors that are suitable for the integration into a golf club with the final goal of their use in real time biofeedback applications. We tested two orthogonally affixed strain gage (SG) sensors, a 3-axis accelerometer, and a 3-axis gyroscope. The strain gage sensors are calibrated and validated in the laboratory environment by a highly accurate Qualisys Track Manager (QTM) optical tracking system. Field test results show that different types of golf swing and improper movement in early phases of golf swing can be detected with strain gage sensors attached to the shaft of the golf club. Thus they are suitable for biofeedback applications to help golfers to learn repetitive golf swings. It is suggested that the use of strain gage sensors can improve the golf swing technical error detection accuracy and that strain gage sensors alone are enough for basic golf swing analysis. Our final goal is to be able to acquire and analyze as many parameters of a smart golf club in real time during the entire duration of the swing. This would give us the ability to design mobile and cloud biofeedback applications with terminal or concurrent feedback that will enable us to speed-up motor skill learning in golf.

  14. [Golf handicap score is a suitable scale for monitoring rehabilitation after apoplexia cerebri].

    Science.gov (United States)

    Jensen, Per; Meden, Per; Knudsen, Lars V; Knudsen, G M; Thomsen, Carsten; Feng, Ling; Pinborg, Lars H

    2015-12-21

    A 67-year-old male was examined nine, 35 and 135 days after stroke using conventional stroke scales, 18 holes of golf, functional MRI (fist closures) and translocator protein imaging of microglial function in the brain using single photon emission computed tomography. The data showed that the over 100-year-old golf handicap scale is better suited for quantifying recovery after stroke than conventional stroke assessment scales, which are prone to ceiling effect. We suggest that rating with golf handicap should be used more widely in stroke research, and we find it tremendously important that these new findings are published before Christmas.

  15. Reliability of P mode event classification using contemporaneous BiSON and GOLF observations

    International Nuclear Information System (INIS)

    Simoniello, R; Chaplin, W J; Elsworth, Y P; Garcia, R A

    2008-01-01

    We carried out a comparison of the signals seen in contemporaneous BiSON and GOLF data sets. Both instruments perform Doppler shift velocity measurements in integrated sunlight, although BiSON perform measurements from the two wings of potassium absorption line and GOLF from one wing of the NaD1 line. Discrepancies between the two datasets have been observed. We show,in fact, that the relative power depends on the wing in which GOLF data observes. During the blue wing period, the relative power is mugh higher than in BiSON datasets, while a good agreement has been observed during the red period.

  16. ANALISA INVESTASI DALAM PENGAMBILAN KEPUTUSAN INVESTASI PADA PENGEMBANGAN LAPANGAN GOLF DAN PERUMAHAN CITRARAYA

    Directory of Open Access Journals (Sweden)

    Njo Anastasia

    2001-01-01

    Full Text Available Investment in the real estate sector has a great risk, therefore a developer needs to do investment analysis before making a decision. The decision is made by considering the returns from two investment alternatives. The first alternative examined is a 9-hole golf course and housing in proximity to the golf. The second alternative is residential property. Given the above conditions, the purpose of this research is to help the developer to make the proper investment decision, based on which alternative has the higher return. Two data collection methods are used in this research, including interviews and a survey which was done by distributing questionnaires to develop a profile of golfers and purchasers as well as potential residential purchasers. Forecasting analysis using the Holt-Winters model was used for forecasting the number of golfers. The Box-Jenkins model was utilized to forecast residential sales. The forecasting results were used for cash flow analysis. The results show that the first alternative produces a higher IRR (25,16% per year and NPV of Rp.25.056.800.000 , relative to the the second alternative with an IRR of 16,72% per year and NPV of Rp.4.794.945.000. Thus, the first alternative, a 9-hole golf course and housing in proximity to the golf, was selected. Abstract in Bahasa Indonesia : Investasi di bidang real estat mengandung risiko besar, sehingga pengembang perlu melakukan analisa investasi sebelum mengambil keputusan. Pengambilan keputusan adalah dengan mempertimbangkan tingkat pengembalian dua alternatif investasi. Alternatif pertama adalah properti 9-hole lapangan golf dan perumahan dalam bentuk kavling golf. Alternatif kedua adalah properti perumahan saja. Dengan kondisi di atas, maka tujuan dari penelitian ini adalah membantu pengembang untuk memutuskan menginvestasikan dananya di alternatif pertama jika tingkat pengembalian investasinya lebih tinggi dibanding alternatif kedua. Metode penelitian yang digunakan adalah

  17. The science of golf putting a complete guide for researchers, players and coaches

    CERN Document Server

    Dias, Gonçalo

    2015-01-01

    This SpringerBrief explores the motor performance and biomechanics of golf putting, providing methodologies, studies and approaches to this concept. Presenting outcomes of research published over the past six years, it offers guidelines from a scientifically oriented perspective, and employs new technologies and mathematical methods to assess golf putting. The chapters cover aspects such as pendulum-like motion in sports, setting up the experimental design, and performance metrics for putting variables. Paving the way for an improved understanding of what leads to failure and success in golf putting, this book offers an invaluable reference source for sports scientists, engineers and mathematicians, as well as golfers.

  18. Ball Screw Actuator Including a Stop with an Integral Guide

    Science.gov (United States)

    Wingett, Paul T. (Inventor); Perek, John (Inventor); Geck, Kellan (Inventor)

    2015-01-01

    An actuator includes a housing assembly, a ball nut, a ball screw, and a ball screw stop. The ball nut is rotationally mounted in the housing assembly, is adapted to receive an input torque, and is configured, upon receipt thereof, to rotate and supply a drive force. The ball screw is mounted within the housing assembly and extends through the ball nut. The ball screw has a first end and a second end, and is coupled to receive the drive force from the ball nut. The ball screw is configured, upon receipt of the drive force, to selectively translate between a stow position and a deploy position. The ball screw stop is mounted on the ball screw to translate therewith and is configured to at selectively engage the housing assembly while the ball screw is translating, and engage the ball nut when the ball screw is in the deploy position.

  19. Synthesis of Randomly Substituted Anionic Cyclodextrins in Ball Milling

    Directory of Open Access Journals (Sweden)

    László Jicsinszky

    2017-03-01

    Full Text Available A number of influencing factors mean that the random substitution of cyclodextrins (CD in solution is difficult to reproduce. Reaction assembly in mechanochemistry reduces the number of these factors. However, lack of water can improve the reaction outcomes by minimizing the reagent’s hydrolysis. High-energy ball milling is an efficient, green and simple method for one-step reactions and usually reduces degradation and byproduct formation. Anionic CD derivatives have successfully been synthesized in the solid state, using a planetary ball mill. Comparison with solution reactions, the solvent-free conditions strongly reduced the reagent hydrolysis and resulted in products of higher degree of substitution (DS with more homogeneous DS distribution. The synthesis of anionic CD derivatives can be effectively performed under mechanochemical activation without significant changes to the substitution pattern but the DS distributions were considerably different from the products of solution syntheses.

  20. Water quality, pesticide occurrence, and effects of irrigation with reclaimed water at golf courses in Florida

    Science.gov (United States)

    Swancar, Amy

    1996-01-01

    Reuse of treated wastewater for golf course irrigation is an increasingly popular water management option in Florida, where growth has put stress on potable water supplies. Surface water, ground water, and irrigation water were sampled at three pairs of golf courses quarterly for one year to determine if pesticides were present, and the effect of irrigation with treated effluent on ground-water quality, with an emphasis on interactions of effluent with pesticides. In addition to the six paired golf courses, which were in central Florida, ground water was sampled for pesticides and other constituents at three more golf courses in other parts of the State. This study was the first to analyze water samples from Florida golf courses for a broad range of pesticides. Statistical methods based on the percentage of data above detection limits were used to determine the effects of irrigation with reclaimed water on ground-water quality. Shallow ground water at golf courses irrigated with treated effluent has higher concentrations of chloride, lower concentrations of bicarbonate, and lower pH than ground water at golf courses irrigated with water from carbonate aquifers. There were no statistically significant differences in nutrient concentrations in ground water between paired golf courses grouped by irrigation water type at a 95 percent confidence level. The number of wells where pesticides occurred was significantly higher at the paired golf courses using ground water for irrigation than at ones using reclaimed water. However, the limited occurrences of individual pesticides in ground water make it difficult to correlate differences in irrigation- water quality with pesticide migration to the water table. At some of the golf courses, increased pesticide occurrences may be associated with higher irrigation rates, the presence of well-drained soils, and shallow depths to the surficial aquifer. Pesticides used by golf courses for turf grass maintenance were detected in

  1. Off site transport of fungicides with snowmelt and rainfall runoff from golf course fairway turf

    Science.gov (United States)

    Pesticides associated with the turfgrass industry have been detected in storm runoff and surface waters of urban watersheds; inferring contaminant contributions from residential, urban, and recreational sources. Golf course turf often requires multiple applications of pesticides at rates that exceed...

  2. Improving performance in golf: current research and implications from a clinical perspective.

    Science.gov (United States)

    Evans, Kerrie; Tuttle, Neil

    2015-01-01

    Golf, a global sport enjoyed by people of all ages and abilities, involves relatively long periods of low intensity exercise interspersed with short bursts of high intensity activity. To meet the physical demands of full swing shots and the mental and physical demands of putting and walking the course, it is frequently recommended that golfers undertake golf-specific exercise programs. Biomechanics, motor learning, and motor control research has increased the understanding of the physical requirements of the game, and using this knowledge, exercise programs aimed at improving golf performance have been developed. However, while it is generally accepted that an exercise program can improve a golfer's physical measurements and some golf performance variables, translating the findings from research into clinical practice to optimise an individual golfer's performance remains challenging. This paper discusses how biomechanical and motor control research has informed current practice and discusses how emerging sophisticated tools and research designs may better assist golfers improve their performance.

  3. Golf Tourism: A Research Profile and Security Perceptions in Belek, Antalya, Turkey.

    Directory of Open Access Journals (Sweden)

    Akın Aksu

    2017-01-01

    Full Text Available Our study aim to determine the current profile of sampled golf tourists visiting Belek, Antalya in high season and their perceptions of security using questionnaires to survey golf tourists in the sample were evaluated separately. The sample consisted of a survey profile of 280 golf tourists and their responses regarding security perceptions for Belek, Antalya. Chi-square testing and descriptive statistics were used to analyze the data. Despite some negative developments in Turkey (such as terrorist attacks, the majority of golf tourists still remain satisfied and motivated to recommend the destination to others. The results of the study would be of help for tourism professionals, academicians and decision makers especially in developing future marketing strategies for Belek.

  4. Apparatus Would Measure Temperatures Of Ball Bearings

    Science.gov (United States)

    Gibson, John C.; Fredricks, Thomas H.

    1995-01-01

    Rig for testing ball bearings under radial and axial loads and measuring surface temperatures undergoing development. Includes extensible thermocouples: by means of bellows as longitudinal positioners, thermocouples driven into contact with bearing balls to sense temperatures immediately after test run. Not necessary to disassemble rig or to section balls to obtain indirect indications of maximum temperatures reached. Thermocouple measurements indicate temperatures better than temperature-sensitive paints.

  5. Multifractal properties of ball milling dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Budroni, M. A., E-mail: mabudroni@uniss.it; Pilosu, V.; Rustici, M. [Dipartimento di Chimica e Farmacia, Università degli Studi di Sassari, Via Vienna 2, Sassari 07100 (Italy); Delogu, F. [Dipartimento di Ingegneria Meccanica, Chimica, e dei Materiali, Università degli Studi di Cagliari, via Marengo 2, Cagliari 09123 (Italy)

    2014-06-15

    This work focuses on the dynamics of a ball inside the reactor of a ball mill. We show that the distribution of collisions at the reactor walls exhibits multifractal properties in a wide region of the parameter space defining the geometrical characteristics of the reactor and the collision elasticity. This feature points to the presence of restricted self-organized zones of the reactor walls where the ball preferentially collides and the mechanical energy is mainly dissipated.

  6. Physical applications of homogeneous balls

    CERN Document Server

    Scarr, Tzvi

    2005-01-01

    One of the mathematical challenges of modern physics lies in the development of new tools to efficiently describe different branches of physics within one mathematical framework. This text introduces precisely such a broad mathematical model, one that gives a clear geometric expression of the symmetry of physical laws and is entirely determined by that symmetry. The first three chapters discuss the occurrence of bounded symmetric domains (BSDs) or homogeneous balls and their algebraic structure in physics. The book further provides a discussion of how to obtain a triple algebraic structure ass

  7. The Soccer-Ball Problem

    Science.gov (United States)

    Hossenfelder, Sabine

    2014-07-01

    The idea that Lorentz-symmetry in momentum space could be modified but still remain observer-independent has received quite some attention in the recent years. This modified Lorentz-symmetry, which has been argued to arise in Loop Quantum Gravity, is being used as a phenomenological model to test possibly observable effects of quantum gravity. The most pressing problem in these models is the treatment of multi-particle states, known as the 'soccer-ball problem'. This article briefly reviews the problem and the status of existing solution attempts.

  8. Crystal ball data acquisition system

    International Nuclear Information System (INIS)

    Chestnut, R.; Kiesling, C.; Bloom, E.; Bulos, F.; Gaiser, J.; Godfrey, G.; Oreglia, M.; Partridge, R.; Peck, C.; Porter, F.; Aschman, D.; Cavali-Sforza, M.; Coyne, D.; Sadrozinski, H.; Kollmann, W.; Richardson, M.

    1979-01-01

    The data acquisition system for the Crystal Ball project at SLAC is described. A PDP-11/t55 using RSX-11M connected to the SLAC Triplex is the basis of the system. A ''physics pipeline'' allows physicists to write their own equipment-monitoring or physics tasks which require event sampling. As well, an interactive analysis package (MULTI) is in the pipeline. Histogram collection and display on the PDP are implemented using the Triplex histogramming package. Various interactive event displays are also implemented

  9. Microstructural Evolution, Thermodynamics, and Kinetics of Mo-Tm2O3 Powder Mixtures during Ball Milling

    Directory of Open Access Journals (Sweden)

    Yong Luo

    2016-10-01

    Full Text Available The microstructural evolution, thermodynamics, and kinetics of Mo (21 wt % Tm2O3 powder mixtures during ball milling were investigated using X-ray diffraction and transmission electron microscopy. Ball milling induced Tm2O3 to be decomposed and then dissolved into Mo crystal. After 96 h of ball milling, Tm2O3 was dissolved completely and the supersaturated nanocrystalline solid solution of Mo (Tm, O was obtained. The Mo lattice parameter increased with increasing ball-milling time, opposite for the Mo grain size. The size and lattice parameter of Mo grains was about 8 nm and 0.31564 nm after 96 h of ball milling, respectively. Ball milling induced the elements of Mo, Tm, and O to be distributed uniformly in the ball-milled particles. Based on the semi-experimental theory of Miedema, a thermodynamic model was developed to calculate the driving force of phase evolution. There was no chemical driving force to form a crystal solid solution of Tm atoms in Mo crystal or an amorphous phase because the Gibbs free energy for both processes was higher than zero. For Mo (21 wt % Tm2O3, it was mechanical work, not the negative heat of mixing, which provided the driving force to form a supersaturated nanocrystalline Mo (Tm, O solid solution.

  10. Effects of golf course management on subsurface soil properties in Iowa

    Science.gov (United States)

    Streeter, Matthew T.; Schilling, Keith E.

    2018-05-01

    Currently, in the USA and especially in the Midwest region, urban expansion is developing turfgrass landscapes surrounding commercial sites, homes, and recreational areas on soils that have been agriculturally managed for decades. Often, golf courses are at the forefront of conversations concerning anthropogenic environmental impacts as they account for some of the most intensively managed soils in the world. Iowa golf courses provide an ideal location to evaluate whether golf course management is affecting the quality of soils at depth. Our study evaluated how soil properties relating to soil health and resiliency varied with depth at golf courses across Iowa and interpreted relationships of these properties to current golf course management, previous land use, and inherent soil properties. Systematic variation in soil properties including sand content, NO3, and soil organic matter (SOM) were observed with depth at six Iowa golf courses among three landform regions. Variability in sand content was identified between the 20 and 50 cm depth classes at all courses, where sand content decreased by as much as 37 %. Highest concentrations of SOM and NO3 were found in the shallowest soils, whereas total C and P variability was not related to golf course management. Sand content and NO3 were found to be directly related to golf course management, particularly at shallow depths. The effects of golf course management dissipated with depth and deeper soil variations were primarily due to natural geologic conditions. The two abovementioned soil properties were very noticeably altered by golf course management and may directly impact crop productivity, soil health, and water quality, and while NO3 may be altered relatively quickly in soil through natural processes, particle size of the soil may not be altered without extensive mitigation. Iowa golf courses continue to be developed in areas of land use change from historically native prairies and more recently agriculture to

  11. A model of greenhouse gas emissions from the management of turf on two golf courses

    International Nuclear Information System (INIS)

    Bartlett, Mark D.; James, Iain T.

    2011-01-01

    An estimated 32,000 golf courses worldwide (approximately 25,600 km 2 ), provide ecosystem goods and services and support an industry contributing over $124 billion globally. Golf courses can impact positively on local biodiversity however their role in the global carbon cycle is not clearly understood. To explore this relationship, the balance between plant-soil system sequestration and greenhouse gas emissions from turf management on golf courses was modelled. Input data were derived from published studies of emissions from agriculture and turfgrass management. Two UK case studies of golf course type were used, a Links course (coastal, medium intensity management, within coastal dune grasses) and a Parkland course (inland, high intensity management, within woodland). Playing surfaces of both golf courses were marginal net sources of greenhouse gas emissions due to maintenance (Links 0.4 ± 0.1 Mg CO 2 e ha -1 y -1 ; Parkland 0.7 ± 0.2 Mg CO 2 e ha -1 y -1 ). A significant proportion of emissions were from the use of nitrogen fertiliser, especially on tees and greens such that 3% of the golf course area contributed 16% of total greenhouse gas emissions. The area of trees on a golf course was important in determining whole-course emission balance. On the Parkland course, emissions from maintenance were offset by sequestration from trees which comprised 48% of total area, resulting in a net balance of -4.3 ± 0.9 Mg CO 2e ha -1 y -1 . On the Links course, the proportion of trees was much lower (2%) and sequestration from links grassland resulted in a net balance of 0.0 ± 0.2 Mg CO 2e ha -1 y -1 . Recommendations for golf course management and design include the reduction of nitrogen fertiliser, improved operational efficiency when mowing, the inclusion of appropriate tree-planting and the scaling of component areas to maximise golf course sequestration capacity. The findings are transferrable to the management and design of urban parks and gardens, which range

  12. A model of greenhouse gas emissions from the management of turf on two golf courses

    Energy Technology Data Exchange (ETDEWEB)

    Bartlett, Mark D., E-mail: m.d.bartlett@cranfield.ac.uk; James, Iain T., E-mail: i.t.james@cranfield.ac.uk

    2011-03-15

    An estimated 32,000 golf courses worldwide (approximately 25,600 km{sup 2}), provide ecosystem goods and services and support an industry contributing over $124 billion globally. Golf courses can impact positively on local biodiversity however their role in the global carbon cycle is not clearly understood. To explore this relationship, the balance between plant-soil system sequestration and greenhouse gas emissions from turf management on golf courses was modelled. Input data were derived from published studies of emissions from agriculture and turfgrass management. Two UK case studies of golf course type were used, a Links course (coastal, medium intensity management, within coastal dune grasses) and a Parkland course (inland, high intensity management, within woodland). Playing surfaces of both golf courses were marginal net sources of greenhouse gas emissions due to maintenance (Links 0.4 {+-} 0.1 Mg CO{sub 2}e ha{sup -1} y{sup -1}; Parkland 0.7 {+-} 0.2 Mg CO{sub 2}e ha{sup -1} y{sup -1}). A significant proportion of emissions were from the use of nitrogen fertiliser, especially on tees and greens such that 3% of the golf course area contributed 16% of total greenhouse gas emissions. The area of trees on a golf course was important in determining whole-course emission balance. On the Parkland course, emissions from maintenance were offset by sequestration from trees which comprised 48% of total area, resulting in a net balance of -4.3 {+-} 0.9 Mg CO{sub 2e} ha{sup -1} y{sup -1}. On the Links course, the proportion of trees was much lower (2%) and sequestration from links grassland resulted in a net balance of 0.0 {+-} 0.2 Mg CO{sub 2e} ha{sup -1} y{sup -1}. Recommendations for golf course management and design include the reduction of nitrogen fertiliser, improved operational efficiency when mowing, the inclusion of appropriate tree-planting and the scaling of component areas to maximise golf course sequestration capacity. The findings are transferrable to the

  13. Utilizing Kolb’s Experiential Learning Theory to Implement a Golf Scramble

    OpenAIRE

    Glenna G. Bower

    2013-01-01

    This study introduced how Kolb’s Experiential Learning Theory was used across the four-mode learning cycle of abstract conceptualization, active experimentation, concrete experience and reflective observation as a pedagogical tool for implementing a golf scramble. The primary research question was to see whether Kolb’s Experiential Learning Theory four-mode learning cycle was an effective means for implementing a the golf scramble. The participants of the experiential learning experience wer...

  14. Root-knot nematodes in golf course greens of the western United States

    Science.gov (United States)

    A survey of 238 golf courses in ten of the Western U.S. found root-knot nematodes (Meloidogyne spp.) in 60 % of the putting greens sampled. Sequence and phylogenetic analyses of 18S rRNA, D2-D3 of 28S rRNA, ITS-rRNA and mtDNA gene sequences were used to identify specimens from 110 golf courses. The...

  15. O golfe e os rumos do Cabo Verde independente = Golfing and the independent Cape Verde directions = El golf y los caminos del Cabo Verde independiente

    Directory of Open Access Journals (Sweden)

    Melo, Victor Andrade de

    2016-01-01

    Full Text Available Em função de uma série de peculiaridades, o golfe tem desempenhado um importante papel na história de Cabo Verde. A prática, que tem uma longa trajetória no arquipélago, em diversas ocasiões foi mobilizada a fim de materializar a ideia de que o cabo-verdiano era portador de um alto padrão civilizacional. No período colonial, essa foi uma das estratégias pelos nativos usada para lidar com o jugo da metrópole, argumento utilizado para requisitar maior respeito às especificidades e atenção às necessidades locais. O que terá mudado nas considerações sobre esse esporte quando chegou a independência (1975? Que diferenças podem ser sentidas nas décadas seguintes? Neste artigo, argumentamos que os discursos sobre a modalidade nos ajudam a lançar um olhar sobre os debates acerca dos rumos do país insular nos últimos 40 anos

  16. The most important "factor" in producing clubhead speed in golf.

    Science.gov (United States)

    Joyce, Christopher

    2017-10-01

    Substantial experiential research into x-factor, and to a lesser extent crunch-factor has been undertaken with the aim of increasing clubhead speed. However, a direct comparison of the golf swing kinematics associated with each 'factor' has not, and possible differences when using a driver compared to an iron. Fifteen low handicap male golfers who displayed a modern swing had their golf swing kinematic data measured when hitting their own driver and five-iron, using a 10-camera motion analysis system operating at 250Hz. Clubhead speed was collected using a validated launch monitor. No between-club differences in x-factor and crunch-factor existed. Correlation analyses revealed within-club segment (trunk and lower trunk) interaction was different for the driver, compared to the five-iron, and that a greater number of kinematic variables associated with x-factor, compared to crunch-factor were shown to be correlated with faster clubhead speeds. This was further explained in the five-iron regression model, where a significant amount of variance in clubhead speed was associated with increased lower trunk x-factor stretch, and reduced trunk lateral bending. Given that greens in regulation was shown to be the strongest correlated variable with PGA Tour earnings (1990-2004), the findings suggests a link to player performance for approach shots. These findings support other empiric research into the importance of x-factor as well as anecdotal evidence on how crunch-factor can negatively affect clubhead speed. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Kinetic constrained optimization of the golf swing hub path.

    Science.gov (United States)

    Nesbit, Steven M; McGinnis, Ryan S

    2014-12-01

    This study details an optimization of the golf swing, where the hand path and club angular trajectories are manipulated. The optimization goal was to maximize club head velocity at impact within the interaction kinetic limitations (force, torque, work, and power) of the golfer as determined through the analysis of a typical swing using a two-dimensional dynamic model. The study was applied to four subjects with diverse swing capabilities and styles. It was determined that it is possible for all subjects to increase their club head velocity at impact within their respective kinetic limitations through combined modifications to their respective hand path and club angular trajectories. The manner of the modifications, the degree of velocity improvement, the amount of kinetic reduction, and the associated kinetic limitation quantities were subject dependent. By artificially minimizing selected kinetic inputs within the optimization algorithm, it was possible to identify swing trajectory characteristics that indicated relative kinetic weaknesses of a subject. Practical implications are offered based upon the findings of the study. Key PointsThe hand path trajectory is an important characteristic of the golf swing and greatly affects club head velocity and golfer/club energy transfer.It is possible to increase the energy transfer from the golfer to the club by modifying the hand path and swing trajectories without increasing the kinetic output demands on the golfer.It is possible to identify relative kinetic output strengths and weakness of a golfer through assessment of the hand path and swing trajectories.Increasing any one of the kinetic outputs of the golfer can potentially increase the club head velocity at impact.The hand path trajectory has important influences over the club swing trajectory.

  18. Golf-Related Low Back Pain: A Review of Causative Factors and Prevention Strategies

    Science.gov (United States)

    Lindsay, David M.; Vandervoort, Anthony A.

    2014-01-01

    Golf is a popular sport with both perceived and real health benefits. However, certain injury risks are also prevalent, particularly to the lower back. Epidemiological studies have shown that lower back pain (LBP) from golf account for between 18% and 54% of all documented ailments, leading many researchers to regard the condition as the most common golf injury. The purpose of this review was to examine the scientific literature to ascertain the risk factors associated with the development of LBP from playing golf and suggest methods to modify or limit these factors. Results of the review indicate that the high frequency of LBP appears multi-factorial although the asymmetrical and forceful nature of the swing along with excessive play and practice, particularly amongst elite players, appear to be common factors. Other factors include swing flaws leading to excessive side-bend and over-rotation of the spine, abnormal muscle recruitment, poor trunk endurance, restricted lead hip internal rotation and the use of unnecessarily stressful club transportation methods. Methods to help control or eliminate excessive stress on the lower back would include reducing the amount spent playing or practicing, seeking professional assistance to assess and adjust swing mechanics, improve trunk and hip flexibility, increase the strength and endurance of the trunk musculature, consider different footwear options and avoid carrying the golf bag. Adopting some or all of these recommendations should allow players to continue to enjoy the sport of golf well into their senior years. PMID:25741420

  19. Ball Nut Preload Diagnosis of the Hollow Ball Screw through Support Vector Machine

    Directory of Open Access Journals (Sweden)

    Yi-Cheng Huang

    2018-01-01

    Full Text Available This paper studies the diagnostic results of hollow ball screws with different ball nut preload through the support vector machine (SVM process. The method is testified by considering the use of ball screw pretension and different ball nut preload. SVM was used to discriminate the hollow ball screw preload status through the vibration signals and servo motor current signals. Maximum dynamic preloads of 2%, 4%, and 6% ball screws were predesigned, manufactured, and conducted experimentally. Signal patterns with different preload features are separatedby SVM. The irregularity development of the ball screw driving motion current and rolling balls vibration of the ball screw can be discriminated via SVM based on complexity perception. The experimental results successfully show that the prognostic status of ball nut preload can be envisaged by the proposed methodology. The smart reasoning for the health of the ball screw is available based on classification of SVM. This diagnostic method satisfies the purposes of prognostic effectiveness on knowing the ball nut preload status

  20. R&W Club Frederick Hosts Second Annual Golf Tourney for The Children’s Inn | Poster

    Science.gov (United States)

    By Carolynne Keenan, Contributing Writer On Sept. 8, more than 40 NCI at Frederick and Leidos Biomedical Research employees, along with family and friends, swapped work clothes for golf gear at Maryland National Golf Club in Middletown. The golfers didn’t just play for fun; they participated in the second annual R&W Club Frederick Golf Tournament to support The Children’s Inn

  1. R&W Club Frederick Raises $1,500 for The Children’s Inn at Annual Golf Tournament | Poster

    Science.gov (United States)

    Forty-four government and contractor employees, along with their friends and family members, took to the Maryland National Golf Club course this fall for a cause. The R&W Club Frederick held its third annual golf tournament at the Middletown, Md., golf course on Sept. 14 to raise funds for The Children’s Inn at NIH, which celebrated its 25th anniversary this year. The Inn

  2. Ball mill tool for crushing coffee and cocoa beans base on fraction size sieving results

    Science.gov (United States)

    Haryanto, B.; Sirait, M.; Azalea, M.; Alvin; Cahyani, S. E.

    2018-02-01

    Crushing is one of the operation units that aimed to convert the size of solid material to be smoother particle’s size. The operation unit that can be used in this crushing is ball mill. The purpose of this study is to foresee the effect of raw material mass, grinding time, and the number of balls that are used in the ball mill tool related to the amount of raw material of coffee and cocoa beans. Solid material that has become smooth is then sieved with sieve mesh with size number: 50, 70, 100, and 140. It is in order to obtain the mass fraction that escaped from each sieve mesh. From the experiment, it can be concluded that mass percentage fraction of coffee powder is bigger than cocoa powder that escaped from the mesh. Hardness and humidity of coffee beans and cocoa beans have been the important factors that made coffee beans is easier to be crushed than cocoa beans.

  3. Preparation of tungsten-iron carbide by ball milling

    International Nuclear Information System (INIS)

    Wang, G.M.; Campbell, S.J.; Calka, A.; Kaczmarek, W.A.

    1996-01-01

    Several sets of elemental powder mixtures of Fe-W-C (W 46 Fe 46 C 8 , W 60 Fe 20 C 20 and W 34 Fe 33 C 33 ) were ball milled using Uni-Ball mill for periods of up to 550 h in vacuum with a ball - to - powder ratio of about 35:1. Depending on the milling time, the main component of the as-milled materials was found to be solid solutions of Fe-W-C or Fe-C. Ternary phase W 3 Fe 3 C was obtained on annealing the as-milled materials at about 700 deg C. This product was then found to transfer to (FeW) 6 C on heat treatment at about 800 deg C. The resultant products of the annealing processes were found to depend not only on the annealing temperature, but also the starting composition, especially the initial carbon concentration. Detailed information on the structural and phase evolution during thermal treatment as measured using x-ray diffraction, Moessbauer spectroscopy and thermal analysis is presented. Special interest is focused on the competition for formation in this system between the Fe-C, W-Fe and W-C phases

  4. Structural and dynamical properties of Yukawa balls

    International Nuclear Information System (INIS)

    Block, D; Kroll, M; Arp, O; Piel, A; Kaeding, S; Ivanov, Y; Melzer, A; Henning, C; Baumgartner, H; Ludwig, P; Bonitz, M

    2007-01-01

    To study the structural and dynamical properties of finite 3D dust clouds (Yukawa balls) new diagnostic tools have been developed. This contribution describes the progress towards 3D diagnostics for measuring the particle positions. It is shown that these diagnostics are capable of investigating the structural and dynamical properties of Yukawa balls and gaining insight into their basic construction principles

  5. Soccer Ball Lift Coefficients via Trajectory Analysis

    Science.gov (United States)

    Goff, John Eric; Carre, Matt J.

    2010-01-01

    We performed experiments in which a soccer ball was launched from a machine while two high-speed cameras recorded portions of the trajectory. Using the trajectory data and published drag coefficients, we extracted lift coefficients for a soccer ball. We determined lift coefficients for a wide range of spin parameters, including several spin…

  6. Study of soccer ball flight trajectory

    Directory of Open Access Journals (Sweden)

    Javorova Juliana

    2018-01-01

    Full Text Available In this paper the trajectories of a soccer ball for the most important kicks in the football game - a corner kick and a direct free kick are studied. The soccer ball is modelled as an ideal rigid hollow spherical body with six degrees of freedom, which performs a general motion in an immovable air environment with constant parameters. The ball 3D orientation is determined by the three Cardan angles. The aerodynamic forces and moments with which the air environment acts to the ball are taken into account. Two of the most dangerous areas of the football goal are defined. Differential equations which describe the motion of the soccer ball are solved numerically by MatLab-Simulink.

  7. A model for ball lightning

    International Nuclear Information System (INIS)

    Fryberger, D.

    1994-10-01

    A model for ball lightning (BL) is described. It is based upon the vorton model for elementary particles, which exploits the symmetry between electricity and magnetism. The core, or driving engine, of BL in this model is comprised of a vorton-antivorton plasma. The energy of BL, which derives from nucleon decay catalyzed by this plasma, leads, through various mechanisms, to BL luminosity as well as to other BL features. It is argued that this model could also be a suitable explanation for other luminous phenomena, such as the unidentified atmospheric light phenomena seen at Hessdalen. It is predicted that BL and similar atmospheric luminous phenomena should manifest certain features unique to this model, which would be observable with suitable instrumentation

  8. La balle et la plume

    Directory of Open Access Journals (Sweden)

    Peter Marquis

    2012-06-01

    Full Text Available Fin octobre 2008, la nouvelle fit l’effet d’une bombe : Barack Obama, alors candidat à la présidence américaine, demanda à la chaîne câblée Fox News de retarder le début du sixième match de la World Series de base-ball afin de diffuser un spot de campagne. Son adversaire, John McCain, soutenu par le camp républicain et une partie de la population, monta aussitôt au créneau pour dénoncer l’hérésie : s’arroger le droit de perturber cette grande finale du championnat au déroulement immuable reve...

  9. Effect of spinal manipulative therapy with stretching compared with stretching alone on full-swing performance of golf players: a randomized pilot trial☆

    Science.gov (United States)

    Costa, Soraya M.V.; Chibana, Yumi E.T.; Giavarotti, Leandro; Compagnoni, Débora S.; Shiono, Adriana H.; Satie, Janice; Bracher, Eduardo S.B.

    2009-01-01

    Abstract Objective There has been a steady growth of chiropractic treatment using spinal manipulative therapy (SMT) that aims to increase the performance of athletes in various sports. This study evaluates the effect of SMT by chiropractors on the performance of golf players. Methods Golfers of 2 golf clubs in São Paulo, Brazil, participated in this study. They were randomized to 1 of 2 groups: Group I received a stretch program, and group II received a stretch program in addition to SMT. Participants in both groups performed the same standardized stretching program. Spinal manipulative therapy to dysfunctional spinal segments was performed on group II only. All golfers performed 3 full-swing maneuvers. Ball range was considered as the average distance for the 3 shots. Treatment was performed after the initial measurement, and the same maneuvers were performed afterward. Each participant repeated these procedures for a 4-week period. Student t test, Mann-Whitney nonparametric test, and 1-way analysis of variance for repeated measures with significance level of 5% were used to analyze the study. Results Forty-three golfers completed the protocol. Twenty participants were allocated to group I and 23 to group II. Average age, handicap, and initial swing were comparable. No improvement of full-swing performance was observed during the 4 sessions on group I (stretch only). An improvement was observed at the fourth session of group II (P = .005); when comparing the posttreatment, group II had statistical significance at all phases (P = .003). Conclusions Chiropractic SMT in association with muscle stretching may be associated with an improvement of full-swing performance when compared with muscle stretching alone. PMID:19948307

  10. Effect of Caffeine on Golf Performance and Fatigue during a Competitive Tournament.

    Science.gov (United States)

    Mumford, Petey W; Tribby, Aaron C; Poole, Christopher N; Dalbo, Vincent J; Scanlan, Aaron T; Moon, Jordan R; Roberts, Michael D; Young, Kaelin C

    2016-01-01

    This study aimed to determine the effect of a caffeine-containing supplement on golf-specific performance and fatigue during a 36-hole competitive golf tournament. Twelve male golfers (34.8 ± 13.9 yr, 175.9 ± 9.3 cm, 81.23 ± 13.14 kg) with a United States Golf Association handicap of 3-10 participated in a double-blind, placebo-controlled, crossover design in which they played an 18-hole round of golf on two consecutive days (36-hole tournament) and were randomly assigned to consume a caffeine-containing supplement (CAF) or placebo (PLA). CAF/PLA was consumed before and after nine holes during each 18-hole round. Total score, drive distance, fairways and greens in regulation, first putt distance, HR, breathing rate, peak trunk acceleration, and trunk posture while putting were recorded. Self-perceived ratings of energy, fatigue, alertness and concentration were also recorded. Total score (76.9 ± 8.1 vs 79.4 ± 9.1, P = 0.039), greens in regulation (8.6 ± 3.3 vs 6.9 ± 4.6, P = 0.035), and drive distance (239.9 ± 33.8 vs 233.2 ± 32.4, P = 0.047) were statistically better during the CAF condition compared with those during PLA. Statistically significant main effects for condition (P golf. There were no substantial differences in HR or breathing rates, peak trunk acceleration, or putting posture between conditions or over the round (P > 0.05). A moderate dose (1.9 ± 0.3 mg · kg(-1)) of caffeine consumed before and during a round of golf improves golf-specific measures of performance and reduces fatigue in skilled golfers.

  11. Performance Study of Graphite Anode Slurry in Lithium-ion Flow Battery by Ball Milling

    Directory of Open Access Journals (Sweden)

    FENG Cai-mei

    2018-02-01

    Full Text Available Graphite anode slurry of lithium-ion flow battery was prepared by the method of ball milling. The morphology, conductivity, specific capacity and cycle performance of graphite anode slurry were studied. Results show that the addition of conductive carbon material can improve the suspension stability of the electrode slurry; the ball milling process can not only improve the suspension stability but also reduce the resistivity of the mixed powders of graphite and conductive carbon materials, the ball milling effect is satisfactory when the mass ratio of the balls and the solid particles is 5:1, but too high ratio of the milling ball and the solid materials can destroy the layer structure of the graphite and affect the stability of the slurry. Increasing the fraction of the graphite and conductive carbon materials can form stable electrical network structure in the slurry and improve the reversible capacity; at the premise of keeping the flowability of the electrode slurry, the reversible specific capacity can be more than 40mAh/g. The capacity loss of graphite anode slurry mainly occurs in the first charging-discharging process, as the increase of the cycles, the capacity loss rate decreases, the capacity goes stable after 5 cycles.

  12. BALL - biochemical algorithms library 1.3

    Directory of Open Access Journals (Sweden)

    Stöckel Daniel

    2010-10-01

    Full Text Available Abstract Background The Biochemical Algorithms Library (BALL is a comprehensive rapid application development framework for structural bioinformatics. It provides an extensive C++ class library of data structures and algorithms for molecular modeling and structural bioinformatics. Using BALL as a programming toolbox does not only allow to greatly reduce application development times but also helps in ensuring stability and correctness by avoiding the error-prone reimplementation of complex algorithms and replacing them with calls into the library that has been well-tested by a large number of developers. In the ten years since its original publication, BALL has seen a substantial increase in functionality and numerous other improvements. Results Here, we discuss BALL's current functionality and highlight the key additions and improvements: support for additional file formats, molecular edit-functionality, new molecular mechanics force fields, novel energy minimization techniques, docking algorithms, and support for cheminformatics. Conclusions BALL is available for all major operating systems, including Linux, Windows, and MacOS X. It is available free of charge under the Lesser GNU Public License (LPGL. Parts of the code are distributed under the GNU Public License (GPL. BALL is available as source code and binary packages from the project web site at http://www.ball-project.org. Recently, it has been accepted into the debian project; integration into further distributions is currently pursued.

  13. A model of greenhouse gas emissions from the management of turf on two golf courses.

    Science.gov (United States)

    Bartlett, Mark D; James, Iain T

    2011-11-01

    An estimated 32,000 golf courses worldwide (approximately 25,600 km2), provide ecosystem goods and services and support an industry contributing over $124 billion globally. Golf courses can impact positively on local biodiversity however their role in the global carbon cycle is not clearly understood. To explore this relationship, the balance between plant–soil system sequestration and greenhouse gas emissions from turf management on golf courses was modelled. Input data were derived from published studies of emissions from agriculture and turfgrass management. Two UK case studies of golf course type were used, a Links course (coastal, medium intensity management, within coastal dune grasses) and a Parkland course (inland, high intensity management, within woodland).Playing surfaces of both golf courses were marginal net sources of greenhouse gas emissions due to maintenance (Links −2.2 ± 0.4 Mg CO2e ha(−1) y(−1); Parkland − 2.0 ± 0.4 Mg CO2e ha(−1) y(−1)). A significant proportion of emissions were from the use of nitrogen fertiliser, especially on tees and greens such that 3% of the golf course area contributed 16% of total greenhouse gas emissions. The area of trees on a golf course was important in determining whole-course emission balance. On the Parkland course, emissions from maintenance were offset by sequestration from turfgrass, and trees which comprised 48% of total area, resulting in a net balance of −5.4 ± 0.9 Mg CO2e ha(−1) y(−1). On the Links course, the proportion of trees was much lower (2%) and sequestration from links grassland resulted in a net balance of −1.6 ± 0.3 Mg CO2e ha(−1) y(−1). Recommendations for golf course management and design include the reduction of nitrogen fertiliser, improved operational efficiency when mowing, the inclusion of appropriate tree-planting and the scaling of component areas to maximise golf course sequestration capacity. The findings are transferrable to the management and design of

  14. Pesticide-free management of weed on golf courses: Current situation and future challenges, European Journal of Turfgrass Science 45(2/14)

    DEFF Research Database (Denmark)

    Jensen, Anne Mette Dahl; Norman Petersen, Karin; Aamlid, Trygve

    2014-01-01

    Restrictions on use of pesticides on recreational areas including golf courses are encouraged by EU legislation. Denmark has introduced legislation in 2013 and set an upper limit on how much pesticide can be used on golf courses. Weeds can impair on golf course quality and must be controlled, esp...

  15. Preferential location for arterial dissection presenting as golf-related stroke.

    Science.gov (United States)

    Choi, M H; Hong, J M; Lee, J S; Shin, D H; Choi, H A; Lee, K

    2014-02-01

    Golf-related stroke has not been systematically reviewed. The purpose of our study was to describe in detail this particular stroke syndrome. Seven patients were analyzed at a university hospital and 7 patients were reviewed from MEDLINE literature. General demographics, symptom onset, neurologic signs, radiologic findings, and outcome were investigated. A total of 14 patients including 7 patients from the MEDLINE search were analyzed; all were men, with a mean age of 46.9 ± 12.8 years. Symptom onset was classified as during the golf swing (n = 9), unknown (n = 3), and after playing golf (n = 2). Most patients (n = 12) showed involvement of the vertebral artery and 2 patients showed involvement of the internal carotid artery (P = .008). Nine dissections were found on the right side, 3 on the left side, and 2 were bilateral (P = .046). Twelve patients had extracranial involvement and 2 patients had intracranial involvement (P = .008). Seven patients returned to normal, 5 returned to independence, 1 had unknown status, and 1 died. The anatomic preference of golf-related craniocervical arterial dissection is associated with the extracranial and vertebrobasilar system with a right-sided tendency as the result of stereotypical rotational movement during a golf swing.

  16. Synchronized metronome training induces changes in the kinematic properties of the golf swing.

    Science.gov (United States)

    Sommer, Marius; Häger, Charlotte; Rönnqvist, Louise

    2014-03-01

    The purpose of this study was to evaluate possible effects of synchronized metronome training (SMT) on movement dynamics during golf-swing performance, as captured by kinematic analysis. A one-group, between-test design was applied on 13 male golfers (27.5 +/- 4.6 years old, 12.7 +/- 4.9 handicap) who completed 12 sessions of SMT over a four-week period. Pre- and post-assessments of golf swings with three different clubs (4-iron, 7-iron, and pitching wedge) were performed using a three-dimensional motion capture system. Club velocity at three different swing phases (backswing, downswing, and follow-through) was measured and cross-correlation analysis of time-series signals were made on joint couplings (wrist-elbow-shoulder) of both arms, and between joints and the club, during the full golf swing. There were significantly higher cross-correlations between joint-couplings and concomitant changes of the associated phase-shift differences, as well as reduced phase-shift variability at post-test. No significant effect of SMT was found for the club velocities. We suggest that domain-general influences of SMT on the underlying brain-based motor control strategies lead to a more coordinated movement pattern of the golf-swing performance, which may explain previous observations of significantly improved golf-shot accuracy and decreased variability after SMT.

  17. Estimating Wear Of Installed Ball Bearings

    Science.gov (United States)

    Keba, John E.; Mcvey, Scott E.

    1993-01-01

    Simple inspection and measurement technique makes possible to estimate wear of balls in ball bearing, without removing bearing from shaft on which installed. To perform measurement, one observes bearing cage while turning shaft by hand to obtain integral number of cage rotations and to measure, to nearest 2 degrees, number of shaft rotations producing cage rotations. Ratio between numbers of cages and shaft rotations depends only on internal geometry of bearing and applied load. Changes in turns ratio reflect changes in internal geometry of bearing provided measurements made with similar bearing loads. By assuming all wear occurs on balls, one computes effective value for this wear from change in turns ratio.

  18. Q-balls in flat potentials

    International Nuclear Information System (INIS)

    Copeland, Edmund J.; Tsumagari, Mitsuo I.

    2009-01-01

    We study the classical and absolute stability of Q-balls in scalar field theories with flat potentials arising in both gravity-mediated and gauge-mediated models. We show that the associated Q-matter formed in gravity-mediated potentials can be stable against decay into their own free particles as long as the coupling constant of the nonrenormalizable term is small, and that all of the possible three-dimensional Q-ball configurations are classically stable against linear fluctuations. Three-dimensional gauge-mediated Q-balls can be absolutely stable in the thin-wall limit, but are completely unstable in the thick-wall limit.

  19. 76 FR 41691 - Safety Zone; BGSU Football Gridiron Classic Golf and Dinner Fireworks, Catawba Island Club, Port...

    Science.gov (United States)

    2011-07-15

    ...-AA00 Safety Zone; BGSU Football Gridiron Classic Golf and Dinner Fireworks, Catawba Island Club, Port.... This zone is intended to restrict vessels from portions of Lake Erie during the BGSU Football Gridiron... Purpose On July 25, 2011, Bowling Green State University will hold its BGSU Football Gridiron Classic Golf...

  20. The Effect of Biological Movement Variability on the Performance of the Golf Swing in High- and Low-Handicapped Players

    Science.gov (United States)

    Bradshaw, Elizabeth J.; Keogh, Justin W. L.; Hume, Patria A.; Maulder, Peter S.; Nortje, Jacques; Marnewick, Michel

    2009-01-01

    The purpose of this study was to examine the role of neuromotor noise on golf swing performance in high- and low-handicap players. Selected two-dimensional kinematic measures of 20 male golfers (n = 10 per high- or low-handicap group) performing 10 golf swings with a 5-iron club was obtained through video analysis. Neuromotor noise was calculated…

  1. Effect of Cyber-Golfing on Balance Amongst the Elderly in Hong Kong: A Pilot Randomised Trial

    Directory of Open Access Journals (Sweden)

    Daniel H.K. Chow

    2015-12-01

    Conclusion: The results of this study suggest that cyber-golfing might be an alternative to golfing, which is capable of enhancing balance ability amongst community-dwelling elderly. The potential of exergaming as a clinical tool for geriatric rehabilitation was discussed.

  2. Penelitian mutu kulit sarung tangan golf samak krom

    Directory of Open Access Journals (Sweden)

    Sri Untari

    1992-12-01

    Full Text Available The Study aimed at improving the quality of chrome-tanned leather for golf floves producted by Indonesian tanners. Samples used in this study were 32. They were visually inspected and tested on their chemical and physical properties. The results of the chemical and physical tests were analyzed using deviation standard in descriptive statistics. It was obtained from the visual inspection of the samples taken that the leather was soft enough, the colour was even, their hair was not loose, and it was flexible but not elastic. While from the Chemical Tests, the results obtained were : water content (13,78 – 16,94 %; Fat Content (6,04 – 11,38 % and pH Valueness (4,43 – 5,19. It was obtained from the physical tests that Thickness (0,32 – 0,64 mm; well tanned; Tensile Strength resistence (106,07 – 109,73 kg/cm2; Flexibility (53,11 – 103,07 %; Slit Tear Resistance (13,48 – 39,22 kgf/cm; Stitch Tear Strength (74,51 – 137,79 kgf/cm, wet rub fastness tst shown a little discolourisation while dry rub fastness test shown no discolourisation.

  3. Think aloud: acute stress and coping strategies during golf performances.

    Science.gov (United States)

    Nicholls, Adam R; Polman, Remco C J

    2008-07-01

    A limitation of the sport psychology coping literature is the amount of time between a stressful episode and the recall of the coping strategies used in the stressful event (Nicholls & Polman, 2007). The purpose of this study was to develop and implement a technique to measure acute stress and coping during performance. Five high-performance adolescent golfers took part in Level 2 verbalization think aloud trials (Ericsson & Simon, 1993), which involved participants verbalizing their thoughts, over six holes of golf. Verbal reports were audio-recorded during each performance, transcribed verbatim, and analyzed using protocol analysis (Ericsson & Simon, 1993). Stressors and coping strategies varied throughout the six holes, which support the proposition that stress and coping is a dynamic process that changes across phases of the same performance (Lazarus, 1999). The results also revealed information regarding the sequential patterning of stress and coping, suggesting that the golfers experienced up to five stressors before reporting a coping strategy. Think aloud appears a suitable method to collect concurrent stress and coping data.

  4. Kinetic Constrained Optimization of the Golf Swing Hub Path

    Directory of Open Access Journals (Sweden)

    Steven M. Nesbit

    2014-12-01

    Full Text Available This study details an optimization of the golf swing, where the hand path and club angular trajectories are manipulated. The optimization goal was to maximize club head velocity at impact within the interaction kinetic limitations (force, torque, work, and power of the golfer as determined through the analysis of a typical swing using a two-dimensional dynamic model. The study was applied to four subjects with diverse swing capabilities and styles. It was determined that it is possible for all subjects to increase their club head velocity at impact within their respective kinetic limitations through combined modifications to their respective hand path and club angular trajectories. The manner of the modifications, the degree of velocity improvement, the amount of kinetic reduction, and the associated kinetic limitation quantities were subject dependent. By artificially minimizing selected kinetic inputs within the optimization algorithm, it was possible to identify swing trajectory characteristics that indicated relative kinetic weaknesses of a subject. Practical implications are offered based upon the findings of the study.

  5. Rheological characterization of nuclear waste using falling-ball rheometry

    International Nuclear Information System (INIS)

    Abbott, J.R.; Unal, C.; Stephens, T.; Pasamehmetoglu, K.O.; Graham, A.L.; Edwards, J.N.

    1994-01-01

    Knowledge of the rheological properties of saturated solutions containing solid particles is very important in nuclear waste management technology. For example, the nuclear waste in the Hanford Site high-level radioactive waste tanks contains strong electrolyte solutions with a high concentration of solids. Previous attempt using rotational viscometers to determine the rheology has shown unusual thixotropic and shear thinning behaviors with a lack of reproducibility. Using falling-ball rheometry, the rheology of the undisturbed simulant may be determined with much better reproducibility. In this study, a well-mixed simulant which has similar chemical composition to the actual waste will be tested. Falling-ball size and density will be varied to get data in a wide range of shear rates. To determine the rheogram, several methods will be tried to match the observed data. Based on these tests, a rheogram can be determined from the model and its best-fit parameters. The simulant shows shear-thinning behavior and a yield stress. This would suggest a H-B model. But when fitting to one of the simulants which showed a very low yield stress, the predictions assuming no yield and assuming yield resulted in no improvement in the fit when assuming yield

  6. Crystal ball single event display

    International Nuclear Information System (INIS)

    Grosnick, D.; Gibson, A.; Allgower, C.; Alyea, J.; Argonne National Lab., IL

    1997-01-01

    The Single Event Display (SED) is a routine that is designed to provide information graphically about a triggered event within the Crystal Ball. The SED is written entirely in FORTRAN and uses the CERN-based HICZ graphing package. The primary display shows the amount of energy deposited in each of the NaI crystals on a Mercator-like projection of the crystals. Ten different shades and colors correspond to varying amounts of energy deposited within a crystal. Information about energy clusters is displayed on the crystal map by outlining in red the thirteen (or twelve) crystals contained within a cluster and assigning each cluster a number. Additional information about energy clusters is provided in a series of boxes containing useful data about the energy distribution among the crystals within the cluster. Other information shown on the event display include the event trigger type and data about π o 's and η's formed from pairs of clusters as found by the analyzer. A description of the major features is given, along with some information on how to install the SED into the analyzer

  7. Static Load Distribution in Ball Bearings

    Science.gov (United States)

    Ricci, Mario

    2010-01-01

    A numerical procedure for computing the internal loading distribution in statically loaded, single-row, angular-contact ball bearings when subjected to a known combined radial and thrust load is presented. The combined radial and thrust load must be applied in order to avoid tilting between inner and outer rings. The numerical procedure requires the iterative solution of Z + 2 simultaneous nonlinear equations - where Z is the number of the balls - to yield an exact solution for axial and radial deflections, and contact angles. Numerical results for a 218 angular-contact ball bearing have been compared with those from the literature and show significant differences in the magnitudes of the ball loads, contact angles, and the extent of the loading zone.

  8. On the formation of ball lightning

    International Nuclear Information System (INIS)

    Silberg, P.A.

    1981-01-01

    A plasma continuum model for the formation of ball lightning is developed based on a substantial number of reports that the ball is often in the discharge column of a previous lightning stroke. The usual method of setting up the plasma equation for a one-component electron plasma is used. An approximate equation for the plasma is derived from the describing equation which is then solved exactly in terms of the Jacobi elliptic functions. The formation of the ball is based on a nonlinearity of the plasma equation which uner certain circumstances permits the field to collapse into a small region. This collapse is interpreted to be ball lightning. The approximate equation derived for the plasma has the same form as a previous equation used to describe the formation of the fireball plasma. (author)

  9. Dolphin underwater bait-balling behaviors in relation to group and prey ball sizes.

    Science.gov (United States)

    Vaughn-Hirshorn, Robin L; Muzi, Elisa; Richardson, Jessica L; Fox, Gabriella J; Hansen, Lauren N; Salley, Alyce M; Dudzinski, Kathleen M; Würsig, Bernd

    2013-09-01

    We characterized dusky dolphin (Lagenorhynchus obscurus) feeding behaviors recorded on underwater video, and related behaviors to variation in prey ball sizes, dolphin group sizes, and study site (Argentina versus New Zealand, NZ). Herding behaviors most often involved dolphins swimming around the side or under prey balls, but dolphins in Argentina more often swam under prey balls (48% of passes) than did dolphins in NZ (34% of passes). This result may have been due to differences in group sizes between sites, since groups are larger in Argentina. Additionally, in NZ, group size was positively correlated with proportion of passes that occurred under prey balls (pdolphins in Argentina more often swam through prey balls (8% of attempts) than did dolphins in NZ (4% of attempts). This result may have been due to differences in prey ball sizes between sites, since dolphins fed on larger prey balls in Argentina (>74m(2)) than in NZ (maximum 33m(2)). Additionally, in NZ, dolphins were more likely to swim through prey balls to capture fish when they fed on larger prey balls (p=0.025). Copyright © 2013 Elsevier B.V. All rights reserved.

  10. Hermitian harmonic maps into convex balls

    International Nuclear Information System (INIS)

    Li Zhenyang; Xi Zhang

    2004-07-01

    In this paper, we consider Hermitian harmonic maps from Hermitian manifolds into convex balls. We prove that there exist no non-trivial Hermitian harmonic maps from closed Hermitian manifolds into convex balls, and we use the heat flow method to solve the Dirichlet problem for Hermitian harmonic maps when the domain is compact Hermitian manifold with non-empty boundary. The case where the domain manifold is complete(noncompact) is also studied. (author)

  11. Thermoelastoplastic Deformation of a Multilayer Ball

    Science.gov (United States)

    Murashkin, E. V.; Dats, E. P.

    2017-09-01

    The problem of centrally symmetric deformation of a multilayer elastoplastic ball in the process of successive accretion of preheated layers to its outer surface is considered in the framework of small elastoplastic deformations. The problems of residual stress formation in the elastoplastic ball with an inclusion and a cavity are solved under various mechanical boundary conditions on the inner surface and for prescribed thermal compression distributions. The graphs of residual stress and displacement fields are constructed.

  12. Hip joint torques during the golf swing of young and senior healthy males.

    Science.gov (United States)

    Foxworth, Judy L; Millar, Audrey L; Long, Benjamin L; Way, Michael; Vellucci, Matthew W; Vogler, Joshua D

    2013-09-01

    Descriptive, laboratory study. To compare the 3-D hip torques during a golf swing between young and senior healthy male amateur golfers. The secondary purpose was to compare the 3-D hip joint torques between the trail leg and lead leg. The generation of hip torques from the hip musculature is an important aspect of the golf swing. Golf is a very popular activity, and estimates of hip torques during the golf swing have not been reported. Twenty healthy male golfers were divided into a young group (mean ± SD age, 25.1 ± 3.1 years) and a senior group (age, 56.9 ± 4.7 years). All subjects completed 10 golf swings using their personal driver. A motion capture system and force plates were used to obtain kinematic and kinetic data. Inverse dynamic analyses were used to calculate 3-D hip joint torques of the trail and lead limbs. Two-way analyses of covariance (group by leg), with club-head velocity as a covariate, were used to compare peak hip torques between groups and limbs. Trail-limb hip external rotator torque was significantly greater in the younger group compared to the senior group, and greater in the trail leg versus the lead leg. When adjusting for club-head velocity, young and senior healthy male amateur golfers generated comparable hip torques during a golf swing, with the exception of the trail-limb hip external rotator torque. The largest hip torque found was the trail-limb hip extensor torque.

  13. Evaluation of golf courses water demand in southern of Portugal for the last three decades

    Science.gov (United States)

    Gago Pedras, Celestina M.; Lança, Rui M.; Martins, Fernando; Fernandez, Helena; Vieira, Cristina; Monteiro, José Paulo; Guerrero, Carlos

    2014-05-01

    Golf is an economic activity with a prominent position in the tourist-sport offer in the region of Algarve. Located in southern of Portugal, this region is the most suitable region for the growth of the golf industry. The climate is characterized by mild winters with slight rainfall and hot and dry summers. The region has an annual average temperature of 14oC and annual precipitation that rarely exceeds 500 mm year-1. Since most of the rainfall occurs concentrated in the winter, irrigation is needed during the remaining months of the year to meet the water demand from plants. A proper irrigation management will allow to optimize the use water, thus it constitutes a key issue for the sustainability of this activity in areas subjected to water scarcity. Currently, remote sensing provides the tools to assess the evolution of the greenish quality of the area in the golf courses. In this study, based on Landsat images, vegetation indices were calculated the Normalized Difference Vegetation Index (NDVI), for the spring and summer seasons during the last 30 years. For the same period, according the data collected from weather stations distributed in the region, maps of precipitation, temperature, solar radiation, relative humidity and wind were produced. According the current maintenance practices and irrigation cycles, maps of potential and real evapotranspiration and with basis on the water balance were calculated, and water deficit maps estimated. Upon crossing this information with the NDVI maps, trends were identified in the consumption of water for irrigation due to the growth of the occupied area by golf courses in the region of Algarve. Since drought problems tend to increase due to climate changes, it becomes relevant the need to conduct this study aiming the research of strategies to ensure the beneficial use of water on golf courses and other turfgrass areas. Keywords: evapotranspiration, golf, irrigation, NDVI, water deficit

  14. The motion of an arbitrarily rotating spherical projectile and its application to ball games

    Science.gov (United States)

    Robinson, Garry; Robinson, Ian

    2013-07-01

    In this paper the differential equations which govern the motion of a spherical projectile rotating about an arbitrary axis in the presence of an arbitrary ‘wind’ are developed. Three forces are assumed to act on the projectile: (i) gravity, (ii) a drag force proportional to the square of the projectile's velocity and in the opposite direction to this velocity and (iii) a lift or ‘Magnus’ force also assumed to be proportional to the square of the projectile's velocity and in a direction perpendicular to both this velocity and the angular velocity vector of the projectile. The problem has been coded in Matlab and some illustrative model trajectories are presented for ‘ball-games’, specifically golf and cricket, although the equations could equally well be applied to other ball-games such as tennis, soccer or baseball. Spin about an arbitrary axis allows for the treatment of situations where, for example, the spin has a component about the direction of travel. In the case of a cricket ball the subtle behaviour of so-called ‘drift’, particularly ‘late drift’, and also ‘dip’, which may be produced by a slow bowler's off or leg-spin, are investigated. It is found that the trajectories obtained are broadly in accord with those observed in practice. We envisage that this paper may be useful in two ways: (i) for its inherent scientific value as, to the best of our knowledge, the fundamental equations derived here have not appeared in the literature and (ii) in cultivating student interest in the numerical solution of differential equations, since so many of them actively participate in ball-games, and they will be able to compare their own practical experience with the overall trends indicated by the numerical results. As the paper presents equations which can be further extended, it may be of interest to research workers. However, since only the most basic principles of fundamental mechanics are employed, it should be well within the grasp of first

  15. The motion of an arbitrarily rotating spherical projectile and its application to ball games

    International Nuclear Information System (INIS)

    Robinson, Garry; Robinson, Ian

    2013-01-01

    In this paper the differential equations which govern the motion of a spherical projectile rotating about an arbitrary axis in the presence of an arbitrary ‘wind’ are developed. Three forces are assumed to act on the projectile: (i) gravity, (ii) a drag force proportional to the square of the projectile's velocity and in the opposite direction to this velocity and (iii) a lift or ‘Magnus’ force also assumed to be proportional to the square of the projectile's velocity and in a direction perpendicular to both this velocity and the angular velocity vector of the projectile. The problem has been coded in Matlab and some illustrative model trajectories are presented for ‘ball-games’, specifically golf and cricket, although the equations could equally well be applied to other ball-games such as tennis, soccer or baseball. Spin about an arbitrary axis allows for the treatment of situations where, for example, the spin has a component about the direction of travel. In the case of a cricket ball the subtle behaviour of so-called ‘drift’, particularly ‘late drift’, and also ‘dip’, which may be produced by a slow bowler's off or leg-spin, are investigated. It is found that the trajectories obtained are broadly in accord with those observed in practice. We envisage that this paper may be useful in two ways: (i) for its inherent scientific value as, to the best of our knowledge, the fundamental equations derived here have not appeared in the literature and (ii) in cultivating student interest in the numerical solution of differential equations, since so many of them actively participate in ball-games, and they will be able to compare their own practical experience with the overall trends indicated by the numerical results. As the paper presents equations which can be further extended, it may be of interest to research workers. However, since only the most basic principles of fundamental mechanics are employed, it should be well within the grasp of first

  16. Scintigraphic diagnosis of sport injuries: Multiple fractures of ribs by golf-players

    International Nuclear Information System (INIS)

    Pohle, W.; Schuemichen, C.; Hoffmann, G.; Keul, J.; Kluemper, A.

    1981-01-01

    Three untrained golf-players suffered from pain in the dorsal region of the left thorax after some training hours. Three to four weeks after the pains had begun serial fractures of ribs were diagnosed by sup(99m)Tc-MDP bonescan-examinations. All fractures were localized near the costal angulus (paravertebral) of these ribs. The fractures are caused by manual tensions. The difficulties in timing the bone-scan and in identifying the morphologic substrate are demonstrated. It is recommended, that golf-players suffering from thoracic pain ought to be examined by bone scan. (orig.) [de

  17. High resolution electrical resistivity tomography of golf course greens irrigated with reclaimed wastewater: Hydrological approach

    Science.gov (United States)

    Tapias, Josefina C.; Lovera, Raúl; Himi, Mahjoub; Gallardo, Helena; Sendrós, Alexandre; Marguí, Eva; Queralt, Ignasi; Casas, Albert

    2014-05-01

    Actually, there are over 300 golf courses and more than three thousand licensed players in Spain. For this reason golf cannot be considered simply a hobby or a sport, but a very significant economic activity. Considered as one of the most rapidly expanding land-use and water demanding business in the Mediterranean, golf course development generates controversy. In the recent years there has been a considerable demand for golf courses to adopt environmentally sustainable strategies and particularly water authorities are forcing by law golf managers to irrigate with alternative water resources, mainly reclaimed wastewater. Watering practices must be based on soil properties that are characterized by samples removed from the different zones of the golf course and submitted to an accredited physical soil testing laboratory. Watering schedules are critical on greens with poor drainage or on greens with excessively high infiltration rates. The geophysical survey was conducted over the greens of the Girona Golf Club. Eighteen electrical resistivity tomographies were acquired using a mixed Wenner-Schlumberger configuration with electrodes placed 0.5 meter apart. Small stainless-steel nails were used as electrodes to avoid any damage in the fine turfgrass of greens The resistivity meter was set for systematically and automatically selects current electrodes and measurement electrodes to sample apparent resistivity values. Particle size analysis (PSA) has been performed on soil materials of any putting green. The PSA analysis has been composed of two distinct phases. The first has been the textural analysis of the soils for determining the content of sand, silt, and clay fraction via the use of a stack of sieves with decreasing sized openings from the top sieve to the bottom. Subsequently, the hydraulic conductivity of the substrates has been evaluated by means of Bredding and Hazen empirical relationships. The results of this research show that the electrical resistivity

  18. Manufacturing of golf club using wood-plastic combination produced by γ-irradiation

    International Nuclear Information System (INIS)

    Yamagami, Masayuki; Tsujii, Yukio; Ohnishi, Tokuhiro; Miyoshi, Hirofumi; Chubachi, Mitsuo; Takada, Hisatoshi.

    1992-01-01

    Wood-plastic combination (WPC) was produced by γ-irradiation of persimmon impregnated with acrylonitrile and styrene. The hardness and strength of WPC obtained were higher than those of an unmodified wood. Thus, it was found that the WPC is suited for a head of golf club, because the Shore hardness value of WPC is 36% greater than that of unmodified wood. An impregnation method of monomers with some pigments could produce colored WPC without diminishing natural grain. Head of golf club could be manufactured from colored WPC in practice. (auhtor)

  19. Scintigraphic diagnosis of sport injuries: Multiple fractures of ribs by golf-players

    Energy Technology Data Exchange (ETDEWEB)

    Pohle, W; Schuemichen, C; Hoffmann, G; Keul, J; Kluemper, A

    1981-02-01

    Three untrained golf-players suffered from pain in the dorsal region of the left thorax after some training hours. Three to four weeks after the pains had begun serial fractures of ribs were diagnosed by sup(99m)Tc-MDP bonescan-examinations. All fractures were localized near the costal angulus (paravertebral) of these ribs. The fractures are caused by manual tensions. The difficulties in timing the bone-scan and in identifying the morphologic substrate are demonstrated. It is recommended, that golf-players suffering from thoracic pain ought to be examined by bone scan.

  20. Effect of high-energy ball milling in the structural and textural properties of kaolinite

    Directory of Open Access Journals (Sweden)

    E. C. Leonel

    2014-06-01

    Full Text Available Through the process of high-energy ball milling it is possible to obtain solid materials with higher surface area and different particle sizes. These characteristics are very important for some application such as adsorption. Besides, applications of some clays depend on the functionalization which, for kaolinite, takes place in the aluminol groups. Modification in the structural and textural properties of kaolinite by high-energy milling can improve functionalization of kaolinite due to the exposure of aluminol groups. In this work studies were done on the influence of high-energy ball milling on the morphological properties of kaolinite, taking into account parameters such as filling of the miller, number of balls and amount of mass to be milled. Moreover, studies involving milling kinetics of purified kaolinite were carried out to verify modification in the morphology of kaolinite with milling time.

  1. Everyday Engineering: Ain't She Sweet--Bats, Rackets, Golf Clubs, and All

    Science.gov (United States)

    Moyer, Richard; Everett, Susan

    2011-01-01

    The pitcher throws the ball and the batter takes a mighty swing. Crack! The ball is hit on the sweet spot and soars to the outfield. Or, you hear a thud! This time, the ball dribbles along the infield ground and the batter's hands sting. Everyone who has played baseball or softball has probably experienced both of these outcomes. This may not seem…

  2. Influences of preload on the friction and wear properties of high-speed instrument angular contact ball bearings

    Directory of Open Access Journals (Sweden)

    Tao ZHANG

    2018-03-01

    Full Text Available For starved-oil or solid lubrication of high-speed instrument angular contact ball bearings, friction heating and wear are the main reasons of bearing failures. This paper presents a dynamic wear simulation model to investigate the impacts of different preload methods and the changes of preload caused by wear on bearing wear life. The integral value QV of stress and sliding velocity in the contact ellipses between a ball and the inner and outer races determines friction heating and wear. The changes of QV with the friction coefficient and the wear volume under constant-force preload and fixed-position preload are analyzed. Results show that under the same initial preload, the QV decreases with an increase of the friction coefficient for both preload methods, and the latter is slightly larger. The wear of the ball and the race is equivalent to the ball diameter reduction. The QV of constant-force preload is almost not changed with a decrease of the ball diameter, but for fixed-position preload, the value decreases firstly and then increases substantially due to insufficient preload, and slipping occurs, the ball diameter is reduced by 0.025%, while the preload is reduced by 60.33%. An estimation of the bearing wear life under different preload methods requires a consideration of the changes in the wear rate of bearing parts. Keywords: Angular contact ball bearings, Bearing life, Dynamic model, Preload methods, Wear rate

  3. Triazole Fungicides Sensitivity of Sclerotinia homoeocarpa in Korean Golf Courses

    Directory of Open Access Journals (Sweden)

    Ji Won Lee

    2017-12-01

    Full Text Available Chemical management of dollar spot in turf may lead to the development of Sclerotinia homoeocarpa populations with reduced fungicide sensitivity. The objective of this study was to investigate resistance of S. homoeocarpa isolates to triazole fungicides and to test cross-resistance among three triazole fungicides. A total of 66 isolates of S. homoeocarpa were collected from 15 golf courses across Korea, and tested via in vitro sensitivity assay against hexaconazole, propiconazole and tebuconazole. EC₅₀ values of the isolates to these fungicides were distributed in the range of 0.001–1.1 a. i. μg ml−1. Based on the EC₅₀ values, twelve representative strains were selected as sensitive isolates including control and insensitive isolates with respect to each fungicide. At a concentration of 0.1 a. i. μg ml−1 for all fungicides, the selected strains were distinguished as sensitive or resistant isolates with the mycelial growth inhibition rate of 50% as the criterion. The EC₅₀ values of resistant strains exposed to hexaconazole, propiconazole and tebuconazole were 20–50 times, 50–70 times, and 77 times greater, respectively, than that of the control strains. Two isolates of S. homoeocarpa S0–41 and Sh14-2-1 showed sensitivity toward all the fungicides used, while two other isolates Sh7-5-1 and Sh2-1-1 showed resistance to all fungicides. Each isolate showed similar resistance to the three types of triazole fungicides, whereby cross-resistance of isolates was confirmed in the present study; all three triazole fungicide combinations displayed significant correlation coefficients equivalent to or greater than 0.8.

  4. Aerodynamic drag of modern soccer balls.

    Science.gov (United States)

    Asai, Takeshi; Seo, Kazuya

    2013-12-01

    Soccer balls such as the Adidas Roteiro that have been used in soccer tournaments thus far had 32 pentagonal and hexagonal panels. Recently, the Adidas Teamgeist II and Adidas Jabulani, respectively having 14 and 8 panels, have been used at tournaments; the aerodynamic characteristics of these balls have not yet been verified. Now, the Adidas Tango 12, having 32 panels, has been developed for use at tournaments; therefore, it is necessary to understand its aerodynamic characteristics. Through a wind tunnel test and ball trajectory simulations, this study shows that the aerodynamic resistance of the new 32-panel soccer ball is larger in the high-speed region and lower in the middle-speed region than that of the previous 14- and 8-panel balls. The critical Reynolds number of the Roteiro, Teamgeist II, Jabulani, and Tango 12 was ~2.2 × 10(5) (drag coefficient, C d  ≈ 0.12), ~2.8 × 10(5) (C d  ≈ 0.13), ~3.3 × 10(5) (C d  ≈ 0.13), and ~2.4 × 10(5) (C d  ≈ 0.15), respectively. The flight trajectory simulation suggested that the Tango 12, one of the newest soccer balls, has less air resistance in the medium-speed region than the Jabulani and can thus easily acquire large initial velocity in this region. It is considered that the critical Reynolds number of a soccer ball, as considered within the scope of this experiment, depends on the extended total distance of the panel bonds rather than the small designs on the panel surfaces.

  5. Effect of a ball skill intervention on children's ball skills and cognitive functions

    NARCIS (Netherlands)

    Westendorp-Haverdings, Marieke; Houwen, Suzanne; Hartman, Esther; Mombarg, Remo; Smith, Joanne; Visscher, Chris

    Purpose: This study examined the effect of a 16-wk ball skill intervention on the ball skills, executive functioning (in terms of problem solving and cognitive flexibility), and in how far improved executive functioning leads to improved reading and mathematics performance of children with learning

  6. Optical and Acoustic Sensor-Based 3D Ball Motion Estimation for Ball Sport Simulators †

    Directory of Open Access Journals (Sweden)

    Sang-Woo Seo

    2018-04-01

    Full Text Available Estimation of the motion of ball-shaped objects is essential for the operation of ball sport simulators. In this paper, we propose an estimation system for 3D ball motion, including speed and angle of projection, by using acoustic vector and infrared (IR scanning sensors. Our system is comprised of three steps to estimate a ball motion: sound-based ball firing detection, sound source localization, and IR scanning for motion analysis. First, an impulsive sound classification based on the mel-frequency cepstrum and feed-forward neural network is introduced to detect the ball launch sound. An impulsive sound source localization using a 2D microelectromechanical system (MEMS microphones and delay-and-sum beamforming is presented to estimate the firing position. The time and position of a ball in 3D space is determined from a high-speed infrared scanning method. Our experimental results demonstrate that the estimation of ball motion based on sound allows a wider activity area than similar camera-based methods. Thus, it can be practically applied to various simulations in sports such as soccer and baseball.

  7. Effect of a ball skill intervention on children's ball skills and cognitive functions.

    Science.gov (United States)

    Westendorp, Marieke; Houwen, Suzanne; Hartman, Esther; Mombarg, Remo; Smith, Joanne; Visscher, Chris

    2014-02-01

    This study examined the effect of a 16-wk ball skill intervention on the ball skills, executive functioning (in terms of problem solving and cognitive flexibility), and in how far improved executive functioning leads to improved reading and mathematics performance of children with learning disorders. Ninety-one children with learning disorders (age 7-11 yr old) were recruited from six classes in a Dutch special-needs primary school. The six classes were assigned randomly either to the intervention or to the control group. The control group received the school's regular physical education lessons. In the intervention group, ball skills were practiced in relative static, simple settings as well as in more dynamic and cognitive demanding settings. Both groups received two 40-min lessons per week. Children's scores on the Test of Gross Motor Development-2 (ball skills), Tower of London (problem solving), Trail Making Test (cognitive flexibility), Dutch Analysis of Individual Word Forms (reading), and the Dutch World in Numbers test (mathematics) at pretest, posttest, and retention test were used to examine intervention effects. The results showed that the intervention group significantly improved their ball skills, whereas the control group did not. No intervention effects were found on the cognitive parameters. However, within the intervention group, a positive relationship (r = 0.41, P = 0.007) was found between the change in ball skill performance and the change in problem solving: the larger children's improvement in ball skills, the larger their improvement in problem solving. The present ball skill intervention is an effective instrument to improve the ball skills of children with learning disorders. Further research is needed to examine the effect of the ball skill intervention on the cognitive parameters in this population.

  8. Laser Sintering Technology and Balling Phenomenon.

    Science.gov (United States)

    Oyar, Perihan

    2018-02-01

    The aim of this review was to evaluate the balling phenomenon which occurs typically in Selective Laser Sintering (SLS). The balling phenomenon is a typical SLS defect, and observed in laser sintered powder, significantly reduces the quality of SLS, and hinders the further development of SLS Technology. Electronic database searches were performed using Google Scholar. The keywords "laser sintering, selective laser sintering, direct metal laser melting, and balling phenomenon" were searched in title/abstract of publications, limited to December 31, 2016. The inclusion criteria were SLS, balling phenomenon, some alloys (such as Cr-Co, iron, stainless steel, and Cu-based alloys) mechanical properties, microstructure and bond strength between metal-ceramic crown, laboratory studies, full text, and in English language. A total of 100 articles were found the initial search and yielded a total of 50 studies, 30 of which did not fulfill the inclusion criteria and were therefore excluded. In addition, 20 studies were found by screening the reference list of all included publications. Finally, 40 studies were selected for this review. The method in question is regulated by powder material characteristics and the conditions of laser processing. The procedure of formation, affecting factors, and the mechanism of the balling effect are very complex.

  9. Scale-up of organic reactions in ball mills: process intensification with regard to energy efficiency and economy of scale.

    Science.gov (United States)

    Stolle, Achim; Schmidt, Robert; Jacob, Katharina

    2014-01-01

    The scale-up of the Knoevenagel-condensation between vanillin and barbituric acid carried out in planetary ball mills is investigated from an engineering perspective. Generally, the reaction proceeded in the solid state without intermediate melting and afforded selectively only one product. The reaction has been used as a model to analyze the influence and relationship of different parameters related to operation in planetary ball mills. From the viewpoint of technological parameters the milling ball diameter, dMB, the filling degree with respect to the milling balls' packing, ΦMB,packing, and the filling degree of the substrates with respect to the void volume of the milling balls' packing, ΦGS, have been investigated at different reaction scales. It was found that milling balls with small dMB lead to higher yields within shorter reaction time, treaction, or lower rotation frequency, rpm. Thus, the lower limit is set considering the technology which is available for the separation of the milling balls from the product after the reaction. Regarding ΦMB,packing, results indicate that the optimal value is roughly 50% of the total milling beakers' volume, VB,total, independent of the reaction scale or reaction conditions. Thus, 30% of VB,total are taken by the milling balls. Increase of the initial batch sizes changes ΦGS significantly. However, within the investigated parameter range no negative influence on the yield was observed. Up to 50% of VB,total can be taken over by the substrates in addition to 30% for the total milling ball volume. Scale-up factors of 15 and 11 were realized considering the amount of substrates and the reactor volume, respectively. Beside technological parameters, variables which influence the process itself, treaction and rpm, were investigated also. Variation of those allowed to fine-tune the reaction conditions in order to maximize the yield and minimize the energy intensity.

  10. Managing phosphorus export from golf courses using industrial byproducts as filter materials

    Science.gov (United States)

    Golf courses, and in particular the tees, fairways, and putting greens, are vulnerable to loss of phosphorus (P) as dissolved reactive P (DRP) through sandy, porous grass rooting media and subsurface tile drainage. Excess levels of phosphorus (P) in surface waters promotes eutrophication, which in t...

  11. CHEMICAL CONTAMINATION AND TOXICITY ASSOCIATED WITH A COASTAL GOLF COURSE COMPLEX

    Science.gov (United States)

    The increasing density of golf courses represents a potential source of contamination to nearby coastal areas, the chemical and biological magnitude of which is almost unknown. The objective of this study was to compare the concentrations of contaminants and toxicities of sedime...

  12. A new method to identify the location of the kick point during the golf swing.

    Science.gov (United States)

    Joyce, Christopher; Burnett, Angus; Matthews, Miccal

    2013-12-01

    No method currently exists to determine the location of the kick point during the golf swing. This study consisted of two phases. In the first phase, the static kick point of 10 drivers (having identical grip and head but fitted with shafts of differing mass and stiffness) was determined by two methods: (1) a visual method used by professional club fitters and (2) an algorithm using 3D locations of markers positioned on the golf club. Using level of agreement statistics, we showed the latter technique was a valid method to determine the location of the static kick point. In phase two, the validated method was used to determine the dynamic kick point during the golf swing. Twelve elite male golfers had three shots analyzed for two drivers fitted with stiff shafts of differing mass (56 g and 78 g). Excellent between-trial reliability was found for dynamic kick point location. Differences were found for dynamic kick point location when compared with static kick point location, as well as between-shaft and within-shaft. These findings have implications for future investigations examining the bending behavior of golf clubs, as well as being useful to examine relationships between properties of the shaft and launch parameters.

  13. Evaluation of a Florida coastal golf complex as a local and watershed source of bioavailable contaminants

    Science.gov (United States)

    Lewis, Michael A., Robert L. Quarles, Darrin D. Dantin and James C. Moore. 2004. Evaluation of a Coastal Golf Complex as a Local and Watershed Source of Bioavailable Contaminants. Mar. Pollut. Bull. 48(3-4):254-262. (ERL,GB 1183). Contaminant fate in coastal areas impacte...

  14. A methodological approach for the biomechanical cause analysis of golf-related lumbar spine injuries.

    Science.gov (United States)

    Sim, Taeyong; Jang, Dong-Jin; Oh, Euichaul

    2014-01-01

    A new methodological approach employing mechanical work (MW) determination and relative portion of its elemental analysis was applied to investigate the biomechanical causes of golf-related lumbar spine injuries. Kinematic and kinetic parameters at the lumbar and lower limb joints were measured during downswing in 18 golfers. The MW at the lumbar joint (LJ) was smaller than at the right hip but larger than the MWs at other joints. The contribution of joint angular velocity (JAV) to MW was much greater than that of net muscle moment (NMM) at the LJ, whereas the contribution of NMM to MW was greater rather than or similar to that of JAV at other joints. Thus, the contribution of JAV to MW is likely more critical in terms of the probability of golf-related injury than that of NMM. The MW-based golf-related injury index (MWGII), proposed as the ratio of the contribution of JAV to MW to that of NMM, at the LJ (1.55) was significantly greater than those at other joints ( golf-related injuries around the lumbar spine. Therefore, both MW and MWGII should be considered when investigating the biomechanical causes of lumbar spine injuries.

  15. Biochar-compost mixtures added to simulated golf greens increase creeping bentgrass growth

    Science.gov (United States)

    Mixtures of 85% sand and 15% mixtures of peat (control), a commercial biochar, a commercial biochar-compost product (CarbonizPN), and seven biochar-commercial compost mixtures were tested on the growth of creeping bentgrass (Agrostis stolonifera L. "007") in simulated golf greens. Physical properti...

  16. A pilot study of indoor air quality in screen golf courses.

    Science.gov (United States)

    Goung, Sun-Ju Nam; Yang, Jinho; Kim, Yoon Shin; Lee, Cheol Min

    2015-05-01

    The aims of this study were to provide basic data for determining policies on air quality for multi-user facilities, including the legal enrollment of the indoor air quality regulation as designated by the Ministry of Environment, and to establish control plans. To this end, concentrations of ten pollutants (PM10, carbon monoxide (CO), carbon dioxide (CO2), nitrogen dioxide (NO2), formaldehyde (HCHO), total volatile organic compounds (TVOCs), radon (Rn), oxone (O3), total bacteria counts (TBC), and asbestos) in addition to nicotine, a smoking index material used to determine the impact of smoking on the air quality, were investigated in indoor game rooms and lobbies of 64 screen golf courses. The average concentration of none of the ten pollutants in the game rooms and lobbies of screen golf courses was found to exceed the limit set by the law. There were, however, pollutant concentrations exceeding limits in some screen golf courses, in order to establish a control plan for the indoor air quality of screen golf courses, a study on the emission sources of each pollutant was conducted. The major emission sources were found to be facility users' activities such as smoking and the use of combustion appliances, building materials, and finishing materials.

  17. Grating Oriented Line-Wise Filtration (GOLF) for Dual-Energy X-ray CT

    Science.gov (United States)

    Xi, Yan; Cong, Wenxiang; Harrison, Daniel; Wang, Ge

    2017-12-01

    In medical X-ray Computed Tomography (CT), the use of two distinct X-ray source spectra (energies) allows dose-reduction and material discrimination relative to that achieved with only one source spectrum. Existing dual-energy CT methods include source kVp-switching, double-layer detection, dual-source gantry, and two-pass scanning. Each method suffers either from strong spectral correlation or patient-motion artifacts. To simultaneously address these problems, we propose to improve CT data acquisition with the Grating Oriented Line-wise Filtration (GOLF) method, a novel X-ray filter that is placed between the source and patient. GOLF uses a combination of absorption and filtering gratings that are moved relative to each other and in synchronization with the X-ray tube kVp-switching process and/or the detector view-sampling process. Simulation results show that GOLF can improve the spectral performance of kVp-switching to match that of dual-source CT while avoiding patient motion artifacts and dual imaging chains. Although significant flux is absorbed by this pre-patient filter, the proposed GOLF method is a novel path for cost-effectively extracting dual-energy or multi-energy data and reducing radiation dose with or without kVp switching.

  18. Addition of biochar to simulated golf greens promotes creeping bentgrass growth

    Science.gov (United States)

    Organic amendments such as peat moss and various composts are typically added to sand-based root zones such as golf greens to increase water and nutrient retention. However, these attributes are generally lost as these amendments decompose in a few years. Biochar is a high carbon, extremely porous ...

  19. EFFECTS OF A COASTAL GOLF COMPLEX ON WATER QUALITY, PERIPHYTON, AND SEAGRASS.

    Science.gov (United States)

    The objective of this study was to determine the effects of a golf course complex on water quality, colonized periphyton and seagrass meadows in adjacent freshwater, near-coastal and wetland areas. The environmental impact of the recreational facility, which uses spray wastewater...

  20. Performance processes within affect-related performance zones: a multi-modal investigation of golf performance.

    Science.gov (United States)

    van der Lei, Harry; Tenenbaum, Gershon

    2012-12-01

    Individual affect-related performance zones (IAPZs) method utilizing Kamata et al. (J Sport Exerc Psychol 24:189-208, 2002) probabilistic model of determining the individual zone of optimal functioning was utilized as idiosyncratic affective patterns during golf performance. To do so, three male golfers of a varsity golf team were observed during three rounds of golf competition. The investigation implemented a multi-modal assessment approach in which the probabilistic relationship between affective states and both, performance process and performance outcome, measures were determined. More specifically, introspective (i.e., verbal reports) and objective (heart rate and respiration rate) measures of arousal were incorporated to examine the relationships between arousal states and both, process components (i.e., routine consistency, timing), and outcome scores related to golf performance. Results revealed distinguishable and idiosyncratic IAPZs associated with physiological and introspective measures for each golfer. The associations between the IAPZs and decision-making or swing/stroke execution were strong and unique for each golfer. Results are elaborated using cognitive and affect-related concepts, and applications for practitioners are provided.

  1. SEDIMENT CHEMICAL CONTAMINATION AND TOXICITY ASSOCIATED WITH A COASTAL GOLF COURSE COMPLEX.

    Science.gov (United States)

    The increasing density of golf courses represents a potential source of sediment contamination to nearby coastal areas, the chemical and biological magnitude of which is almost unknown. The objective of this study was to determine the concentrations of contaminants and toxicities...

  2. GOLF COURSES AS A SOURCE OF COASTAL CONTAMINATION AND TOXICITY: A FLORIDA EXPERIENCE

    Science.gov (United States)

    The chemical and biological impacts of two coastal golf courses that receive wastewater spray irrigation were determined during a two-year period. A variety of techniques were used to assess the spatial and temporal variability of contaminant levels and their bioavailability in t...

  3. You Don't Have to Be a Professional Golfer to Teach Golf

    Science.gov (United States)

    Hill, Kory; Thornburg, Roland

    2005-01-01

    Although physical educators cannot be experts on every sport or activity, there is still a need to include specialized activities in the curriculum that a physical educator may not initially feel comfortable teaching because of inexperience and a lack of expertise. Golf, like other activities such as tennis, requires a specificity of training that…

  4. Assessment of management of a golf course by means of sustainability indicators

    Directory of Open Access Journals (Sweden)

    Gaio Cesare Pacini

    2016-06-01

    Full Text Available Golf courses are supposed to produce remarkable negative effects on the environment, due to some techniques involved in their management. To provide data useful for the proper assessment of the agro-environmental sustainability of a golf course, the framework agro-environmental sustainability information system (AESIS was used, utilizing a set of indicators suitable to evaluate different dimensions of sustainability (physical, ecological, productive and social. The management of areal golf course located in Tuscany (central Italy was compared to an alternative land use of the same area represented by an ordinary farm based on a sunflower-wheat rotation. Assessment indicators were selected by applying a conceptual model based on ecology theory and were calculated considering site-specific production and pedo-climatic features of the area. Different weighting scenarios were hypothesized in order to have different management options assessed and to carry out a targeted sensitivity analysis. Main results confirmed the significant impact of golf management on some ecological characteristics but the holistic assessment of AESIS approach permitted an overall evaluation that comprised a wide range of different issues. AESIS demonstrated to be a practical and adaptive tool able to perform an efficient comparison of possible land destinations.

  5. Etiologies of pediatric craniofacial injuries: a comparison of injuries involving all-terrain vehicles and golf carts.

    Science.gov (United States)

    White, Lauren C; McKinnon, Brian J; Hughes, C Anthony

    2013-03-01

    To determine incidence and etiologies of craniofacial injuries in the pediatric population through comparison of injuries caused by all-terrain vehicles and golf cart trauma. Case series with chart review. Level 1 trauma center. Retrospective review of pediatric traumas at a tertiary academic medical center from 2003 to 2012 identified 196 patients whose injuries resulted from accidents involving either all-terrain vehicles or golf carts. Data was collected and variables such as age, gender, driver vs. passenger, location of accident, Glasgow coma scale, Injury severity scale, Abbreviated injury scale, and presence or absence of helmet use were examined. 196 pediatric patients were identified: 68 patients had injuries resulting from golf cart accidents, and 128 patients from ATV accidents. 66.4% of ATV-related traumas were male, compared to 52.9% of golf cart-related traumas. Ages of injured patients were similar between the two modalities with average age of ATV traumas 10.8 (±4.0) years and golf cart traumas 10.0 (±4.6) years. Caucasians were most commonly involved in both ATV (79.7%) and golf cart traumas (85.3%). 58.6% of all ATV related trauma and 69.1% of all golf cart trauma resulted in craniofacial injuries. The most common craniofacial injury was a closed head injury with brief loss of consciousness, occurring in 46.1% of the ATV traumas and 54.4% of the golf cart traumas. Temporal bone fractures were the second most common type of craniofacial injury, occurring in 5.5% of ATV accidents and 7.4% of the golf cart traumas. Length of hospital stay and, cases requiring surgery and severity scores were similar between both populations. Intensive care admissions and injury severity scores approached but not reach statistical significance (0.096 and 0.083, respectively). The only statistically significant differences between the two modalities were helmet use (P=0.00018%) and days requiring ventilator assistance (P=0.025). ATVs and golf carts are often exempt

  6. Procedimiento y viabilidad para el envío de paquetes en campos de Golf mediante tecnologia drone

    OpenAIRE

    Pedrosa Cabello, Sergio

    2017-01-01

    The main objective of this project is to study the feasibility of using drones in golf courses and designing an operative use. The first step was to conduct a search for the existence of drones with the ability to carry packages and see if this service currently exists on some golf course. After this search it was concluded that the technology needed to make a delivery of a package with dron exists and that there is no golf course in Europe that performs an operation of this style. The next s...

  7. Skin cancer prevention and detection campaign at golf courses on Spain's Costa del Sol.

    Science.gov (United States)

    del Boz, J; Fernández-Morano, T; Padilla-España, L; Aguilar-Bernier, M; Rivas-Ruiz, F; de Troya-Martín, M

    2015-01-01

    Skin cancer prevention and detection campaigns targeting specific groups are necessary and have proven to be more effective than those aimed at the general population. Interventions in outdoor tourist spots have proven successful, although none have specifically targeted golf courses. The aims of this study were to describe the risk profile of golfers and golf course workers and evaluate the impact of a skin cancer prevention and early detection intervention. This was a cross-sectional descriptive study conducted at 6 golf courses. The intervention included a skin examination and completion of a questionnaire about demographic details, risk factors, and sun exposure and sun protection habits. Participants were also given advice on sun protection measures, self-examination, and use of sunscreens, and were asked about their satisfaction with the intervention and their intention to change their current behaviors. The effect was measured in terms of the diagnoses made, satisfaction with the intervention, reported intention to change, and potential effect in terms of existing risk factors. Of the 351 participants (57% golfers and 43% golf course workers), 70.4% had fair skin, 11.7% had a family history of skin cancer, and 8.5% had a personal history of skin cancer. Skin cancer and actinic keratoses were diagnosed in 10.7% and 40% of the golfers, respectively. The session was rated positively by 99.4% of the participants; 93.9% stated that they intended to improve their sun exposure habits and 93.4% said that they planned to examine their skin more frequently. Our findings confirm that golf course workers and, in particular, golfers are an important target for skin cancer prevention campaigns. This is the first intervention to specifically target golf courses, and it proved to be both feasible and useful. Its success appears to be attributable to numerous factors: it was conducted at golf courses, had multiple components, and was preceded by a motivational campaign

  8. The Development and Validation of a Golf Swing and Putt Skill Assessment for Children

    Science.gov (United States)

    Barnett, Lisa M.; Hardy, Louise L.; Brian, Ali S.; Robertson, Sam

    2015-01-01

    The aim was to describe development of a process-oriented instrument designed to assess the golf swing and putt stroke, and to assess the instrument’s discriminative validity in terms of age and reliability (intra-rater and re-test). A Delphi consultation (with golf industry professionals and researchers in movement skill assessment) was used to develop an assessment for each skill based on existing skill assessment protocols. Each skill had six components to be marked as present/absent. Individual scores were based on the number of performance components successfully demonstrated over two trials for each skill (potential score range 0 to 24). Children (n = 43) aged 6-10 years (M = 7.8 years, SD = 1.3) were assessed in both skills live in the field by one rater at Time 1(T1). A subset of children (n = 28) had consent for assessments to be videoed. Six weeks later 19 children were reassessed, five days apart (T2, T3). An ANOVA assessed discriminative validity i.e. whether skill competence at T1 differed by age (6 years, 7/8 years and 9/10 years). Intraclass correlations (ICC) assessed intra-rater reliability between the live and video assessment at T1 and test-retest reliability (between T2 and T3). Paired t-tests assessed any systematic differences between live and video assessments (T1) and between T2 and T3. Older children were more skilled (F (2, 40) = 11.18, p golf coaches and physical education teachers as part of systematic early player assessment and feedback. Key points Golf is becoming an increasingly popular sport among young children, however there is no standard protocol available to assess and identify skill deficits, mastery level, and talent identification in beginner young golf players. Process rather than product oriented outcomes better identify areas of skill deficit in young children. The proposed swing and putt instrument can reliably identify skill deficits in children of elementary school age who are new to golf and can be used by a range

  9. The development and validation of a golf swing and putt skill assessment for children.

    Science.gov (United States)

    Barnett, Lisa M; Hardy, Louise L; Brian, Ali S; Robertson, Sam

    2015-03-01

    The aim was to describe development of a process-oriented instrument designed to assess the golf swing and putt stroke, and to assess the instrument's discriminative validity in terms of age and reliability (intra-rater and re-test). A Delphi consultation (with golf industry professionals and researchers in movement skill assessment) was used to develop an assessment for each skill based on existing skill assessment protocols. Each skill had six components to be marked as present/absent. Individual scores were based on the number of performance components successfully demonstrated over two trials for each skill (potential score range 0 to 24). Children (n = 43) aged 6-10 years (M = 7.8 years, SD = 1.3) were assessed in both skills live in the field by one rater at Time 1(T1). A subset of children (n = 28) had consent for assessments to be videoed. Six weeks later 19 children were reassessed, five days apart (T2, T3). An ANOVA assessed discriminative validity i.e. whether skill competence at T1 differed by age (6 years, 7/8 years and 9/10 years). Intraclass correlations (ICC) assessed intra-rater reliability between the live and video assessment at T1 and test-retest reliability (between T2 and T3). Paired t-tests assessed any systematic differences between live and video assessments (T1) and between T2 and T3. Older children were more skilled (F (2, 40) = 11.18, p < 0.001). The live assessment reflected the video assessment (ICC = 0.79, 95% CI 0.59, 0.90) and scores did not differ between live and video assessments. Test retest reliability was acceptable (ICC = 0.60, 95% CI 0.23, 0.82), although the mean score was slightly higher at retest. This instrument could be used reliably by golf coaches and physical education teachers as part of systematic early player assessment and feedback. Key pointsGolf is becoming an increasingly popular sport among young children, however there is no standard protocol available to assess and identify skill deficits, mastery level

  10. Electrostatic charge bounds for ball lightning models

    International Nuclear Information System (INIS)

    Stephan, Karl D

    2008-01-01

    Several current theories concerning the nature of ball lightning predict a substantial electrostatic charge in order to account for its observed motion and shape (Turner 1998 Phys. Rep. 293 1; Abrahamson and Dinniss 2000 Nature 403 519). Using charged soap bubbles as a physical model for ball lightning, we show that the magnitude of charge predicted by some of these theories is too high to allow for the types of motion commonly observed in natural ball lightning, which includes horizontal motion above the ground and movement near grounded conductors. Experiments show that at charge levels of only 10-15 nC, 3-cm-diameter soap bubbles tend to be attracted by induced charges to the nearest grounded conductor and rupture. We conclude with a scaling rule that can be used to extrapolate these results to larger objects and surroundings

  11. Ball-and-socket ankle joint

    International Nuclear Information System (INIS)

    Pistoia, F.; Ozonoff, M.B.; Wintz, P.; Hartford Hospital, CT

    1987-01-01

    The ball-and-socket ankle joint is a malformation of the ankle in which the articular surface of the talus is hemispherical in both the anteroposterior and lateral projections and has a congruent, concave tibial articular surface. Fourteen patients with this condition were identified retrospectively. Thirteen patients were thought to have the congenital type of ball-and-socket ankle joint which in many was associated with tarsal coalition, short limb, and ray fusion and deletion anomalies. One case of the acquired type, demonstrating less geometric rounding of the talar margins, was seen in a patient with myelomeningocele, probably resulting from sensory and motor deficits. Although the exact etiology of the congenital type is unknown, its association with other malformations suggests that the ball-and-socket ankle joint results from an overall maldevelopment of the ankle and foot. (orig.)

  12. Kinematic relationship between rotation of lumbar spine and hip joints during golf swing in professional golfers.

    Science.gov (United States)

    Mun, Frederick; Suh, Seung Woo; Park, Hyun-Joon; Choi, Ahnryul

    2015-05-14

    Understanding the kinematics of the lumbar spine and hip joints during a golf swing is a basic step for identifying swing-specific factors associated with low back pain. The objective of this study was to examine the kinematic relationship between rotational movement of the lumbar spine and hip joints during a golf swing. Fifteen professional golfers participated in this study with employment of six infrared cameras to record their golf swings. Anatomical reference system of the upper torso, pelvis and thigh segments, and the location of each hip and knee joint were defined by the protocols of the kinematic model of previous studies. Lumbar spine and hip joint rotational angle was calculated utilizing the Euler angle method. Cross-correlation and angle-angle plot was used to examine the degree of kinematic relationship between joints. A fairly strong coupling relationship was shown between the lumbar spine and hip rotational movements with an average correlation of 0.81. Leading hip contribution to overall rotation was markedly high in the early stage of the downswing, while the lumbar spine contributed greater towards the end of the downswing; however, the relative contributions of the trailing hip and lumbar spine were nearly equal during the entire downswing. Most of the professional golfers participated in this study used a similar coordination strategy when moving their hips and lumbar spine during golf swings. The rotation of hips was observed to be more efficient in producing the overall rotation during the downswing when compared to the backswing. These results provide quantitative information to better understand the lumbar spine and hip joint kinematic characteristics of professional golfers. This study will have great potential to be used as a normal control data for the comparison with kinematic information among golfers with low back pain and for further investigation of golf swing-specific factors associated with injury.

  13. Evaluation of water demand in golf courses from southern Portugal during the last three decades

    Science.gov (United States)

    Gago Pedras, Celestina M.; Lança, Rui M.; Granja-Martins, Fernando M.; Neto-Paixão, Helena M.; Vieira, Cristina; Monteiro, José P.; Guerrero, Carlos

    2014-05-01

    Golf is an economic activity with a prominent position in the tourist-sport offer in the region of Algarve. Located in southern of Portugal, this region is the most suitable region for the growth of the golf industry. The climate is characterized by mild winters with slight rainfall and hot and dry summers. The region has an annual average temperature of 14oC and annual precipitation that rarely exceeds 500 mm year-1. Since most of the rainfall occurs concentrated in the winter, irrigation is needed during the remaining months of the year to meet the water demand from plants. A proper irrigation management will allow to optimize the use water, thus it constitutes a key issue for the sustainability of this activity in areas subjected to water scarcity. Currently, remote sensing provides the tools to assess the evolution of the greenish quality of the area in the golf courses. In this study, based on Landsat images, vegetation indices were calculated the Normalized Difference Vegetation Index (NDVI), for the spring and summer seasons during the last 30 years. For the same period, according the data collected from weather stations distributed in the region, maps of precipitation, temperature, solar radiation, relative humidity and wind were produced. According the current maintenance practices and irrigation cycles, maps of potential and real evapotranspiration and with basis on the water balance were calculated, and water deficit maps estimated. Upon crossing this information with the NDVI maps, trends were identified in the consumption of water for irrigation due to the growth of the occupied area by golf courses in the region of Algarve. Since drought problems tend to increase due to climate changes, it becomes relevant the need to conduct this study aiming the research of strategies to ensure the beneficial use of water on golf courses and other turfgrass areas.

  14. Golf Course Irrigation with Reclaimed Water in the Mediterranean: A Risk Management Matter

    Directory of Open Access Journals (Sweden)

    Miquel Salgot

    2012-04-01

    Full Text Available Controversy regarding the amount of water consumed or saved as a result of human activity is currently paramount in water-scarce areas. In recent decades, golf—a land and water consuming activity—has been implanted in several areas of the Mediterranean basin, where the scarcity of water resources is well-known. As a result, the use of conventional water resources for golf course irrigation is increasingly contested and its replacement by reclaimed water has become essential. This paper examines the wide range of issues involved in its use on golf courses, including hazards—due to the presence of microorganisms and pollutants—and the corresponding risks that can appear. The resulting biological, chemical and physical water quality concerns are analyzed. Legal aspects related to the use of reclaimed water are also discussed and good reuse practices are suggested, including a detailed examination of risk assessment procedures and tools through observation or chemical, physical and microbiological analysis. The HACCP system—which focuses on quality determination in water samples from relevant control points—is described in detail, as it is generally accepted as one of the most scientific ways to detect health problems on a golf course. The paper concludes that, given the increasing availability of treated and reclaimed water and the water needs of golf courses, the future development of the sport in areas without surplus water resources—such as the Mediterranean basin—will predictably depend upon the use of reclaimed water. In recent years, risk assessment or analysis has emerged as an essential tool to guarantee the application of reclaimed water at an acceptable risk level. There certainly have been considerable advances and improvements in the tools that guarantee the safe use of reclaimed water, although current methods available require simplification for their practical application. Nevertheless, protocols applied at present

  15. On longevity of I-ball/oscillon

    Energy Technology Data Exchange (ETDEWEB)

    Mukaida, Kyohei [Kavli IPMU (WPI), UTIAS, The University of Tokyo,Kashiwa, Chiba 277-8583 (Japan); Takimoto, Masahiro [Theory Center, KEK,1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan); Department of Particle Physics and Astrophysics, Weizmann Institute of Science,Rehovot 7610001 (Israel); Yamada, Masaki [Institute of Cosmology, Department of Physics and Astronomy, Tufts University,Medford, MA 02155 (United States); Department of Physics, Tohoku University,Sendai, Miyagi 980-8578 (Japan)

    2017-03-23

    We study I-balls/oscillons, which are long-lived, quasi-periodic, and spatially localized solutions in real scalar field theories. Contrary to the case of Q-balls, there is no evident conserved charge that stabilizes the localized configuration. Nevertheless, in many classical numerical simulations, it has been shown that they are extremely long-lived. In this paper, we clarify the reason for the longevity, and show how the exponential separation of time scales emerges dynamically. Those solutions are time-periodic with a typical frequency of a mass scale of a scalar field. This observation implies that they can be understood by the effective theory after integrating out relativistic modes. We find that the resulting effective theory has an approximate global U(1) symmetry reflecting an approximate number conservation in the non-relativistic regime. As a result, the profile of those solutions is obtained via the bounce method, just like Q-balls, as long as the breaking of the U(1) symmetry is small enough. We then discuss the decay processes of the I-ball/oscillon by the breaking of the U(1) symmetry, namely the production of relativistic modes via number violating processes. We show that the imaginary part is exponentially suppressed, which explains the extraordinary longevity of I-ball/oscillon. In addition, we find that there are some attractor behaviors during the evolution of I-ball/oscillon that further enhance the lifetime. The validity of our effective theory is confirmed by classical numerical simulations. Our formalism may also be useful to study condensates of ultra light bosonic dark matter, such as fuzzy dark matter, and axion stars, for instance.

  16. Soccer ball lift coefficients via trajectory analysis

    International Nuclear Information System (INIS)

    Goff, John Eric; Carre, Matt J

    2010-01-01

    We performed experiments in which a soccer ball was launched from a machine while two high-speed cameras recorded portions of the trajectory. Using the trajectory data and published drag coefficients, we extracted lift coefficients for a soccer ball. We determined lift coefficients for a wide range of spin parameters, including several spin parameters that have not been obtained by today's wind tunnels. Our trajectory analysis technique is not only a valuable tool for professional sports scientists, it is also accessible to students with a background in undergraduate-level classical mechanics.

  17. Soccer ball lift coefficients via trajectory analysis

    Energy Technology Data Exchange (ETDEWEB)

    Goff, John Eric [Department of Physics, Lynchburg College, Lynchburg, VA 24501 (United States); Carre, Matt J, E-mail: goff@lynchburg.ed [Department of Mechanical Engineering, University of Sheffield, Sheffield S1 3JD (United Kingdom)

    2010-07-15

    We performed experiments in which a soccer ball was launched from a machine while two high-speed cameras recorded portions of the trajectory. Using the trajectory data and published drag coefficients, we extracted lift coefficients for a soccer ball. We determined lift coefficients for a wide range of spin parameters, including several spin parameters that have not been obtained by today's wind tunnels. Our trajectory analysis technique is not only a valuable tool for professional sports scientists, it is also accessible to students with a background in undergraduate-level classical mechanics.

  18. The Effects of Resistance Training on Golf Performance and Physiological Stress Response During Competition in Intercollegiate Golfers

    National Research Council Canada - National Science Library

    Doan, Brandon

    2002-01-01

    ...) on clubhead speed, consistency, and putting distance control. 2) To investigate the effects of 36 continuous holes of competitive golf on testosterone and cortisol response and their relation to performance. Study #1...

  19. Optimum condition determination of Rirang uranium ores grinding using ball mill

    International Nuclear Information System (INIS)

    Affandi, Kosim; Waluyo, Sugeng; Sarono, Budi; Sujono; Muhammad

    2002-01-01

    The grinding experiment on Rirang Uranium ore has been carried out with the aim is to find out the optimum condition of wet grinding using ball mill to produce particle size -325, -200 and -100 mesh. This will be used for decomposition feed the test was done by examine the parameters comparison of ore's weight against ball's weight and time of grinding. The test shown that the product of particle size -325 meshes was achieved optimum condition at the comparison ore's weight: ball = 1:3, grinding time 150 minutes, % solid 60, speed rotation of ball mill 60 rpm and recovery of grinding was 93.51 % of -325 mesh. The product of particle size -200 mesh was achieved optimum condition at comparison ore's weight: ball = 1:2, time of grinding 60 minutes, the fraction of + 200 mesh was regrind, the recovery of grinding 6.82% at particle size of (-200 + 250) mesh, 5.75 % at (-250 + 325)m mesh and, 47.93 % -325 mesh. The product of particle size -100 mesh was achieved the optimum condition at comparison ore's weight: ball = 1:2, time of grinding at 30 minutes particle size +100 mesh regrinding using mortar grinder, recovery of grinding 30.10% at particle size (-100 + 150) m, 12.28 % at (-150 + 200) mesh, 15.92 % at (-200 + 250) mesh, 12.44 % at (-250 + 325) mesh and 29.26 % -325 mesh. The determination of specific gravity of Rirang uranium ore was between 4.15 - 4.55 g/cm 3

  20. Ball-milling-induced crystallization and ball-milling effect on thermal crystallization kinetics in an amorphous FeMoSiB alloy

    International Nuclear Information System (INIS)

    Guo, F.Q.; Lu, K.

    1997-01-01

    Microstructure evolution in a melt-spun amorphous Fe 77.2 Mo 0.8 Si 9 B 13 alloy subjected to high-energy ball milling was investigated by means of X-ray diffraction (XRD), a transmission electron microscope (TEM), and a differential scanning calorimeter (DSC). It was found that during ball milling, crystallization occurs in the amorphous ribbon sample with precipitation of an α-Fe solid solution, and the amorphous sample crystallizes completely into a single α-Fe nanostructure (rather than α-Fe and borides as in the usual thermal crystallization products) when the milling time exceeds 135 hours. The volume fraction of material crystallized was found to be approximately proportional to the milling time. The fully crystallized sample with a single α-Fe nanophase exhibits an intrinsic thermal stability against phase separation upon annealing at high temperatures. The ball-milling effect on the subsequent thermal crystallization of the amorphous phase in an as-milled sample was studied by comparison of the crystallization products and kinetic parameters between the as-quenched amorphous sample and the as-milled sample was studied by comparison of the crystallization products and kinetic parameters between the as-quenched amorphous sample and the as-milled partially crystallized samples. The crystallization temperatures and activation energies for the crystallization processes of the residual amorphous phase were considerably decreased due to ball milling, indicating that ball milling has a significant effect on the depression of thermal stability of the residual amorphous phase

  1. From a Ball Game to Incompleteness

    Indian Academy of Sciences (India)

    We present a ball game that can be continued as long as wewish. It looks as though the game would never end. But byapplying a result on trees, we show that the game nonethelessends in some finite number of moves. We then point out somedeep results on the natural number system connected withthe game.

  2. 4 π physics with the plastic ball

    International Nuclear Information System (INIS)

    Gutbrod, H.H.; Loehner, H.; Poskanzer, A.M.; Renner, T.; Riedesel, H.; Ritter, H.G.; Warwick, A.; Weik, F.; Wieman, H.

    1982-10-01

    4 π data taken with the Plastic Ball show that cluster production in relativistic nuclear collisions depends on both the size of the participant volume and the finite size of the cluster. The measurement of the degree of thermalization and the search for collective flow will permit the study of the applicability of macroscopic concepts such as temperature and density

  3. Crystal Ball results on tau decays

    International Nuclear Information System (INIS)

    Lowe, S.T.

    1987-10-01

    This report reviews measurements and upper limit determinations for a number of exclusive 1-prong tau decay modes using the Crystal Ball detector. These results are important input to the apparent discrepancy between the topological and sum-of-exclusive branching fractions in 1-prong tau decays

  4. A plasma ball in the Microcosm museum

    CERN Multimedia

    Maximilien Brice

    2005-01-01

    Plasma balls, like the one shown here, are displayed in the Microcosm exhibition where families can visit to learn more about the experiments carried out in a research institute like CERN. Hands-on activities allow visitors to get a step closer to the research activities carried out at CERN.

  5. Fractal Aggregates in Tennis Ball Systems

    Science.gov (United States)

    Sabin, J.; Bandin, M.; Prieto, G.; Sarmiento, F.

    2009-01-01

    We present a new practical exercise to explain the mechanisms of aggregation of some colloids which are otherwise not easy to understand. We have used tennis balls to simulate, in a visual way, the aggregation of colloids under reaction-limited colloid aggregation (RLCA) and diffusion-limited colloid aggregation (DLCA) regimes. We have used the…

  6. Soccer Ball Production for Nike in Pakistan

    NARCIS (Netherlands)

    K.A. Siegmann (Karin Astrid)

    2008-01-01

    textabstractThis paper looks at how Nike’s soccer ball suppliers (previous and current) in Sialkot (Pakistan) fare in relation to the company’s code of ethics. While minimum required working conditions are implemented, the criteria for social and environmental compliance are not met with. The

  7. When Two Balls Are Just One

    Science.gov (United States)

    Kulp, Christopher W.; Biermann, Mark L.; Howard, Timothy; Klingenberg, Kurtis; Ramsey, Paul

    2008-01-01

    A camcorder can be a powerful tool in pedagogical settings, such as in an introductory physics course or in introducing undergraduates to data collection. In this paper, we discuss our experience using a Panasonic PV-GS150 digital camcorder to analyze the motion of a falling steel ball, with the goal of determining the acceleration due to gravity,…

  8. On the dynamics of ball bearings

    NARCIS (Netherlands)

    Wensing, J.A.

    1998-01-01

    This investigation on the dynamic behaviour of ball bearings was motivated by the demand for silent bearings in noise-sensitive applications, especially in the household appliance and automotive industry. The present investigations are intended to provide a clear understanding of the role of the

  9. Treatment of Travel Expenses by Golf Course Patrons: Sunk or Bundled Costs and the First and Third Laws of Demand

    OpenAIRE

    Matt, Brown; Daniel, Rascher; Chad, McEvoy; Mark, Nagel

    2007-01-01

    To attract golf patrons, sport managers must understand consumption patterns of the golfer. Importantly, the treatment of travel costs must be understood. According to the Alchian-Allen (1964) theorem, golfers treat travel costs as bundled costs (third law of economic demand) whereas classical consumer theory indicates that golfers treat travel costs as sunk costs (first law of economic demand). The purpose of this study was to determine if golf patrons treated travel costs as sunk costs o...

  10. R&W Club Frederick Hosts 4th Annual Golf Tournament Benefiting The Children’s Inn at NIH | Poster

    Science.gov (United States)

    The R&W Club Frederick’s 4th Annual Golf Tournament to benefit the Children’s Inn at NIH teed off on time despite cloudy weather and scattered showers. Employees from NCI at Frederick, the main NIH campus, and Leidos Biomed, along with family and friends, came to enjoy an afternoon at the beautiful Maryland National Golf Club in Middletown and to support a wonderful charity.

  11. Effects of golf course construction and operation on water chemistry of headwater streams on the Precambrian Shield

    International Nuclear Information System (INIS)

    Winter, Jennifer G.; Dillon, Peter J.

    2005-01-01

    To investigate the effects of golf course construction and operation on the water chemistry of Shield streams, we compared the water chemistry in streams draining golf courses under construction (2) and in operation (5) to streams in forested reference locations and to upstream sites where available. Streams were more alkaline and higher in base cation and nitrate concentrations downstream of operational golf courses. Levels of these parameters and total phosphorus increased over time in several streams during golf course construction through to operation. There was evidence of inputs of mercury to streams on two of the operational courses. Nutrient (phosphorus and nitrogen) concentrations were significantly related to the area of unmanaged vegetation in a 30 x 30 m area on either side of the sampling sites, and to River Bank Quality Index scores, suggesting that maintaining vegetated buffers along the stream on golf courses will reduce in-stream nutrient concentrations. - Golf course construction and operation had a significant impact on alkalinity, nitrogen and base cation concentrations of streams

  12. Validity and Reliability of a Medicine Ball Explosive Power Test.

    Science.gov (United States)

    Stockbrugger, Barry A.; Haennel, Robert G.

    2001-01-01

    Evaluated the validity and reliability of a medicine ball throw test to evaluate explosive power. Data on competitive sand volleyball players who performed a medicine ball throw and a standard countermovement jump indicated that the medicine ball throw test was a valid and reliable way to assess explosive power for an analogous total-body movement…

  13. Anti-collapse mechanism of CBM fuzzy-ball drilling fluid

    Directory of Open Access Journals (Sweden)

    Lihui Zheng

    2016-03-01

    Full Text Available Although fuzzy-ball drilling fluid has been successfully applied in CBM well drilling, it is necessary to study its anti-collapse mechanism so that adjustable coalbed sealing effects, controllable sealing strength, rational sealing cost and controllable reservoir damage degree can be realized. In this paper, laboratory measurement was performed on the uniaxial compressive strength of the plungers of No. 3 coalbed in the Qinshui Basin and the inlet pressure of Ø38 mm coal plunger displacement. The strengths of coal plungers were tested and compared after 2% potassium chloride solution, low-solids polymer drilling fluid and fuzzy-ball drilling fluid were injected into the coal plungers respectively. It is shown that coal strength rises by 38.46% after the fuzzy-ball drilling fluid is injected (in three groups; and that no fuzzy-ball drilling fluid is lost at the displacement pressures of 20.73 and 21.46 MPa, nor 2% potassium chloride solution is leaked at such pressures of 24.79 and 25.64 MPa after the plunger was sealed by the fuzzy-ball drilling fluid. This indicates that the fuzzy-ball drilling fluid can increase the formation resistance to fluid. Indoor microscopic observation was conducted on the sealing process of the fuzzy-ball drilling fluid in sand packs with coal cuttings of three grain sizes (60–80, 80–100 and 100–120 mesh. It is shown that the leakage pathways of different sizes are sealed by the vesicles in the form of accumulation, stretch and blockage. And there are vesicles at the inlet ends of the flowing pathways in the shape of beaded blanket. The impact force of drilling tools on the sidewalls is absorbed by the vesicles due to their elasticity and tenacity, so the sidewall instability caused by drilling tools is relieved. It is concluded that the main anti-collapse mechanisms of the CBM fuzzy-ball drilling fluid are to raise the coal strength, increase the formation resistance to fluid, and buffer the impact of

  14. Replacing by numbers - computer aided installation of ball screws in a CANDU

    International Nuclear Information System (INIS)

    Granz, R.; Georgas, J.

    1992-01-01

    Performing repair procedures on a commissioned nuclear reactor is a critical maintenance task and certainly not one suitable for on-the-job experimentation. That was our dilemma when the engineering staff developed what was thought would be a better way to replace the ball screws in the fuelling machine support bridges of a CANDU nuclear plant. The 40ft long ball screws must be installed vertically into square cavities that are less than 40ft from the ''ceiling'' of the room where they are located. Standard operating procedures for replacing the ball screw involve opening up the feeder cabinet located above to provide clearance. But this practice risks damage to delicate piping located inside the cabinet. The new concept involved walking the ball screw in by tilting it at a series of angles. Unfortunately, there was no simple way that we could determine with pencil and paper whether or not this approach would work or exactly how to do it in practice. Using the solid modelling capabilities of the Aries Concept Station mechanical computer-aided engineering system, we proved the new procedure and developed a series of illustrations offering step-by-step visual instructions to guide the maintenance crew performing the task. (Author)

  15. Campos de golf y medio ambiente. Una interacción necesaria

    Directory of Open Access Journals (Sweden)

    Cayetano Espejo Marín

    2004-01-01

    Full Text Available Desde finales de la década de los años ochenta del siglo pasado hay una preocupación generalizada por el impacto de los campos de golf sobre el medio ambiente. Varias Comunidades Autónomas españolas han redactado una normativa que permite controlar la incidencia de los campos de golf sobre dos aspectos fundamentales: las transformaciones paisajísticas y la procedencia del agua consumida. Las evaluaciones de impacto ambiental y el uso cada vez más generalizado de aguas depuradas contribuyen a minimizar los efectos sobre el entorno de estas instalaciones, que constituyen una interesante oferta turística de calidad sin estacionalidad.

  16. Quasi-stiffness of the knee joint in flexion and extension during the golf swing.

    Science.gov (United States)

    Choi, Ahnryul; Sim, Taeyong; Mun, Joung Hwan

    2015-01-01

    Biomechanical understanding of the knee joint during a golf swing is essential to improve performance and prevent injury. In this study, we quantified the flexion/extension angle and moment as the primary knee movement, and evaluated quasi-stiffness represented by moment-angle coupling in the knee joint. Eighteen skilled and 23 unskilled golfers participated in this study. Six infrared cameras and two force platforms were used to record a swing motion. The anatomical angle and moment were calculated from kinematic and kinetic models, and quasi-stiffness of the knee joint was determined as an instantaneous slope of moment-angle curves. The lead knee of the skilled group had decreased resistance duration compared with the unskilled group (P golf swing and developing rehabilitation strategies following surgery.

  17. Putting Like a Pro: The Role of Positive Contagion in Golf Performance and Perception

    Science.gov (United States)

    Lee, Charles; Linkenauger, Sally A.; Bakdash, Jonathan Z.; Joy-Gaba, Jennifer A.; Profitt, Dennis R.

    2011-01-01

    Many amateur athletes believe that using a professional athlete's equipment can improve their performance. Such equipment can be said to be affected with positive contagion, which refers to the belief of transference of beneficial properties between animate persons/objects to previously neutral objects. In this experiment, positive contagion was induced by telling participants in one group that a putter previously belonged to a professional golfer. The effect of positive contagion was examined for perception and performance in a golf putting task. Individuals who believed they were using the professional golfer's putter perceived the size of the golf hole to be larger than golfers without such a belief and also had better performance, sinking more putts. These results provide empirical support for anecdotes, which allege that using objects with positive contagion can improve performance, and further suggest perception can be modulated by positive contagion. PMID:22028804

  18. NCI Takes Back the Defelice Cup at Ninth Annual Golf Tournament | Poster

    Science.gov (United States)

    By Ashley DeVine, Staff Writer After being down by a point in the morning, NCI reclaimed the Defelice Cup trophy from Leidos Biomedical Research, with a final score of 12 ½ to 11 ½, at the ninth annual Ronald H. Defelice Golf Tournament, held Oct. 13. “The tightest matches in the nine-year history of this cup competition resulted in a narrow victory for NCI and allowed NCI to

  19. SOCIAL LEGITIMACY VERSUS BUSINESS PERFORMANCE IN THE ENVIRONMENTAL SOCIAL RESPONSIBILITY POLICIES OF ANDALUSIAN GOLF COURSES

    Directory of Open Access Journals (Sweden)

    Francisco José, Riquel Ligero

    2012-01-01

    Full Text Available This paper attempts an analysis of organizational motivations when developing policies for environmental liability. Specifically, to compare the production of social legitimacy to the improvement of organizational performance, we proceeded to test two models in a sector which in recent years has opened a wide debate on environmental sustainability. We refer to golf tourism in Andalusia, in which there has been a considerable increase in such facilities. We have used the statistical technique Partial Least Square (PLS.

  20. Helioseismic inferences of the solar cycles 23 and 24: GOLF and VIRGO observations

    Science.gov (United States)

    Salabert, D.; García, R. A.; Jiménez, A.

    2014-12-01

    The Sun-as-a star helioseismic spectrophotometer GOLF and photometer VIRGO instruments onboard the SoHO spacecraft are collecting high-quality, continuous data since April 1996. We analyze here these unique datasets in order to investigate the peculiar and weak on-going solar cycle 24. As this cycle 24 is reaching its maximum, we compare its rising phase with the rising phase of the previous solar cycle 23.

  1. The Analysis of Knee Joint Movement During Golf Swing in Professional and Amateur Golfers

    OpenAIRE

    M.Somjarod; V. Tanawat; l. Weerawat

    2011-01-01

    The understanding of knee movement during swing importance for golf swing improving and preventing injury. Thirty male professional and amateur golfers were assigned to swing time by time for 3 times. Data from a vedio-based motion capture were used to compute knee joint movement variables. The results showed that professional and amateur golfers were significantly in left knee flexion angle at the impact point and mid follow through phase. Nevertheless, left knee externa...

  2. 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

  3. How does gravity save or kill Q-balls?

    International Nuclear Information System (INIS)

    Tamaki, Takashi; Sakai, Nobuyuki

    2011-01-01

    We explore stability of gravitating Q-balls with potential V 4 (φ)=(m 2 /2)φ 2 -λφ 4 +(φ 6 /M 2 ) via catastrophe theory, as an extension of our previous work on Q-balls with potential V 3 (φ)=(m 2 /2)φ 2 -μφ 3 +λφ 4 . In flat spacetime Q-balls with V 4 in the thick-wall limit are unstable and there is a minimum charge Q min , where Q-balls with Q min are nonexistent. If we take self-gravity into account, on the other hand, there exist stable Q-balls with arbitrarily small charge, no matter how weak gravity is. That is, gravity saves Q-balls with small charge. We also show how stability of Q-balls changes as gravity becomes strong.

  4. Waste minimization assessment for a manufacturer of baseball bats and golf clubs. Environmental research brief

    Energy Technology Data Exchange (ETDEWEB)

    Fleischman, M.; Kirsch, F.W.; Maginn, J.C.

    1993-09-01

    The U.S. Environmental Protection Agency (EPA) has funded a pilot project to assist small and medium-size manufacturers who want to minimize their generation of waste but who lack the expertise to do so. Waste Minimization Assessment Center (WMAC) at the University of Louisville performed an assessment at a plant manufacturing baseball bats and golf clubs -- approximately 1,500,000 bats/yr and 550,000 golf clubs/yr. To make the bats, wood billets are oven-dried and machined to a standard dimension. After sanding they are branded and finished. The golf clubs are made by finishing and assembling purchased heads and shafts. The team's report detailing findings and recommendations, indicated that the most waste, other than rinse water discharged to the publicly owned treatment works (POTW) and wood turnings which are sold, consists of scrap cardboard and paper from the shop and offices, and that the greatest savings, including new income, could be obtained by segregating the cardboard and paper wastes for sale to a local recycler.

  5. Examination of the suitability of collecting in event cognitive processes using Think Aloud protocol in golf.

    Directory of Open Access Journals (Sweden)

    Amy Elizabeth Whitehead

    2015-07-01

    Full Text Available Two studies examined the use of think aloud (TA protocol as a means for collecting data of cognitive processes during performance in golf. In study 1, TA was employed to examine if different verbalisation (Level 2 or Level 3 TA instructions influence performance of high and low skilled golfers. Participants performed 30 putts using TA at either Level 2, Level 3, or no verbalization condition. Although Level 3 verbalization produced a higher volume of verbal data than Level 2, TA at either level 2 or 3 did not impair putting performance compared to no verbalization. Study 2 examined the congruence between data collected via TA at Level 3 and cued retrospective recall of cognitive processes during golf performance. Experienced golfers performed six holes of golf whilst engaging in Level 3 TA. After performance, three semi-structured retrospective interviews were conducted (ten minutes after performance, 24 hours after performance and 48 hours after performance. A comparison of the themes identified large discrepancies between the information reported during TA and at interview, with only 38-41% similarity in variables reported to influence decision making on each hole. Both studies suggest TA is a valuable method for recording cognitive processes of individuals during task performance. TA provides richer verbal data regarding decisions than cued retrospective recall, and TA does not negatively impact performance.

  6. Relationships between golf range users’ participation motivation, satisfaction, and exercise adherence intention

    Directory of Open Access Journals (Sweden)

    Kyoung-Ran Shim

    2017-05-01

    Full Text Available Purpose - This paper aims to identify the relationship between participation motivation, satisfaction and exercise adherence intention of golf range users on the basis of self-determination theory. Design/methodology/approach - For this purpose, the authors proposed research questions and a conceptual research model as well. Then, the authors surveyed users of golf ranges located in Seoul Metropolitan City and Gyeonggi-do province. Findings - By applying convenience sampling, the authors received a total of 313 questionnaires. Results were as follows. First, among the participation motivation sub-factors, health-oriented motivation, achievement motivation, pleasure-oriented motivation and self-displayed motivation had a significant effect on emotional satisfaction, while achievement motivation and pleasure-orientation motivation had a significant effect on performance satisfaction. Second, the following participation motivation factors had a significant effect on exercise adherence intention: health-orientation motivation, achievement motivation and pleasure-orientation motivation. Third, among the satisfaction factors, emotional satisfaction and performance satisfaction both had a significant effect on exercise adherence intention. Originality/value - This is one of the first papers to examine the relationships that exist between golf range users’ participation motivation, satisfaction and exercise adherence intention.

  7. In Their Own Words: Stakeholder Perceptions of the Golf World Cup, 2006

    Directory of Open Access Journals (Sweden)

    Wendy Sealy

    2015-06-01

    Full Text Available This paper presents a framework for the formulation of a sport tourism event policy for the island of Barbados. Although some research has been conducted on the residents’ perceptions of major sporting events including the Olympic Games, smaller but globally significant events such as the Golf World Cup have received little attention from researchers. Less attention has been given to sport events in the Caribbean. This dearth in knowledge has inspired the direction of this study, which is, to explore the stakeholder perceptions of the Golf World Cup which was hosted in Barbados in December 2006. The data collection process adopted included semi-structured interviews with the Barbados tourism private sector. The 65 participants in this study highlighted a diversity of mainly congruent views. Private sector participants contend that the Golf World Cup was socially exclusive and perpetuated social divisions rather than ameliorated them. Many stakeholders felt that the event was culturally alienating and highlighted the failure of the organisers to undertake stakeholder consultations. The findings in this study can make a worthwhile contribution to the marketing, management and design of future events and the direction of policy formulation for sport events on the island of Barbados and the wider Caribbean.

  8. Golf-course and funnel energy landscapes: Protein folding concepts in martensites

    Science.gov (United States)

    Shankaraiah, N.

    2017-06-01

    We use protein folding energy landscape concepts such as golf course and funnel to study re-equilibration in athermal martensites under systematic temperature quench Monte Carlo simulations. On quenching below a transition temperature, the seeded high-symmetry parent-phase austenite that converts to the low-symmetry product-phase martensite, through autocatalytic twinning or elastic photocopying, has both rapid conversions and incubation delays in the temperature-time-transformation phase diagram. We find the rapid (incubation delays) conversions at low (high) temperatures arises from the presence of large (small) size of golf-course edge that has the funnel inside for negative energy states. In the incubating state, the strain structure factor enters into the Brillouin-zone golf course through searches for finite transitional pathways which close off at the transition temperature with Vogel-Fulcher divergences that are insensitive to Hamiltonian energy scales and log-normal distributions, as signatures of dominant entropy barriers. The crossing of the entropy barrier is identified through energy occupancy distributions, Monte Carlo acceptance fractions, heat emission, and internal work.

  9. Evaluation of a Florida coastal golf complex as a local and watershed source of bioavailable contaminants

    International Nuclear Information System (INIS)

    Lewis, Michael A.; Quarles, Robert L.; Dantin, Darrin D.; Moore, James C.

    2004-01-01

    Contaminant fate in coastal areas impacted by golf course runoff is not well understood. This report summarizes trace metal, pesticide and PCB residues for colonized periphyton, Ruppia maritima (widgeon grass), Callinectes sapidus Rathbun (blue crabs) and Crassostrea virginica Gemlin (Eastern oyster) collected from areas adjacent to a Florida golf course complex which receive runoff containing reclaimed municipal wastewater. Concentrations of 19 chlorinated pesticides and 18 PCB congeners were usually below detection in the biota. In contrast, 8 trace metals were commonly detected although concentrations were not usually significantly different for biota collected from reference and non-reference coastal areas. Residue concentrations in decreasing order were typically: zinc, arsenic, copper, chromium, lead, nickel, cadmium and mercury. Mean BCF values for the eight trace metals ranged between 160-57 000 (periphyton), 79-11 033 (R. maritima), 87-162 625 (C. virginica) and 12-9800 (C. sapidus). Most trace metal residues in periphyton colonized adjacent to the golf complex, were either similar to or significantly less than those reported for periphyton colonized in nearby coastal areas impacted by urban stormwater runoff and treated municipal and industrial wastewater discharges. Consequently, the recreational complex does not appear to be a major source of bioavailable contaminants locally nor in the immediate watershed based on results for the selected biota

  10. Electromyographic analyses of the erector spinae muscles during golf swings using four different clubs.

    Science.gov (United States)

    Sorbie, Graeme G; Grace, Fergal M; Gu, Yaodong; Baker, Julien S; Ugbolue, Ukadike C

    2018-04-01

    The purpose of this study was to compare the electromyography (EMG) patterns of the thoracic and lumbar regions of the erector spinae (ES) muscle during the golf swing whilst using four different golf clubs. Fifteen right-handed male golfers performed a total of twenty swings in random order using the driver, 4-iron, 7-iron and pitching-wedge. Surface EMG was recorded from the lead and trail sides of the thoracic and lumbar regions of the ES muscle (T8, L1 and L5 lateral to the spinous-process). Three-dimensional high-speed video analysis was used to identify the backswing, forward swing, acceleration, early and late follow-through phases of the golf swing. No significant differences in muscle-activation levels from the lead and trail sides of the thoracic and lumbar regions of the ES muscle were displayed between the driver, 4-iron, 7-iron and pitching-wedge (P > 0.05). The highest mean thoracic and lumbar ES muscle-activation levels were displayed in the forward swing (67-99% MVC) and acceleration (83-106% MVC) phases of the swing for all clubs tested. The findings from this study show that there were no significant statistical differences between the driver, 4-iron, 7-iron and pitching-wedge when examining muscle activity from the thoracic and lumbar regions of the ES muscle.

  11. The effects of golf training in patients with stroke: a pilot study.

    Science.gov (United States)

    Schachten, Tobias; Jansen, Petra

    2015-05-01

    Stroke is the most common neurological disease and the primary cause of lifelong disability in industrialized countries. Because of this it is important to investigate any kind of successful therapy. From the 24 recruited stroke patients who were between 23 and 72 years old, 14 patients were separated either in a golf training group (EG), or a social communication meeting (CG). Both groups met for one hour sessions, twice a week, for ten weeks. All participants completed assessment tests before and after the experimental period: cognitive tests measuring attention (Go/No-Go task), visual-spatial memory (Block-Tapping test) and mental rotation performance (MRT); a balance test (Berg Balance Scale), and an emotional well-being test (CES-D-Scale). The results show that both groups improved in the CES Scale, the block-tapping test and the balance test. In addition, stroke patients who received a golf training showed a significant improvement in the MRT comparing to the control group (CG). It is indicated that golf training can improve visual imagery ability in stroke patients, even late after stroke.

  12. PREFERENSI PENGHUNI TINGGAL DI APARTEMEN BERSUBSIDI THE MODERN GOLF KOTA TANGERANG

    Directory of Open Access Journals (Sweden)

    Prima Dea Arijani

    2017-06-01

    Full Text Available Pemenuhan kebutuhan perumahan layak bagi masyarakat menengah kebawah dan pembangunan perumahan vertikal menjadi sangat penting dalam mengurangi kepadatan. The Modern Golf Apartement menjadi apartemen bersubsidi pertama yang dibangun di kota Tangerang dengan statusnya yang bersubsidi memiliki daya tarik tersendiri bagi para penghuni untuk tinggal. Tujuan dari penelitian ini adalah untuk mengetahui preferensi dan tujuan penghuni untuk tinggal di apartemen bersubsidi The Modern Golf. Metode analisis yang digunakan dalam penelitian ini adalah metode deskriptif kuantitatif dengan teknik sampling stratified random sampling. Berdasarkan analisis, diketahui bahwa faktor penghuni tinggal di apartemen bersubsidi The Modern Golf yang memiliki preferensi paling tinggi berdasakan nilai rata-ratanya yaitu faktor kemudahan aksesibilitas menuju sarana perdagangan dengan nilai rata-rata 4,63. Hal ini diperkuat dengan adanya berbagai jenis sarana perdagangan yang dapat memudahkan penghuni untuk memenuhi kebutuhannya tanpa perlu keluar dari kawasan The Modernland, serta terdapat kecenderungan aktivitas bahwa penghuni akan menuju ke sarana perdagangan baik mall maupun pusat pertokoan setelah pulang bekerja. Hal tersebut menunjukkan bahwa adanya fenomena masyarakat perkotaan yang cenderung konsumtif serta tingginya minat masyarakat terhadap hunian yang berada di pusat kota dengan dilengkapi dengan sarana prasarana pendukung.

  13. El impacto ambiental de campos de golf. Un caso real en Toledo

    Directory of Open Access Journals (Sweden)

    Sobrini, I. M.

    2001-12-01

    Full Text Available We expose the environmental impact statement (EIS of a future golf course in Toledo city (Spain. This golf course is included in an ambitious scientific-medical research project concerning new therapies through the practice of golf for medullary handicapped persons, in addition with a cultural approach between the three big monotheistic religions that have historically lived together in Toledo. The methodology used to carry out the EIS was very particular and easy to be extrapolated to similar cases, but not to be generalized. It was based in comparing the future project. with the actual intensive irrigation farming of the land, and with the future urban consequences due lo its position next to Toledo city. The comparison between the different environmental impacts of this project and a the actual use of the land, suffering a very intensive irrigation farming, and b the future without the project, was favourable to the golf course, because it was concerned as less aggressive. An appropriate water managing will allow reducing the consumption from the actual 99 l/s authorised for agricultural use, until 54 l/s required for the golf course, improving the environment of this section of the Tajo river: The turf management will be less harmful than the irrigation farming, this one being held nowadays with a high pesticide consumption. Later on, environmental management practice will allow to reduce costs and will help to increase golf-players environmental consciousness. This new golf course will provide the integration o/ this section of Tajo River in the future urban development of Toledo city, creating a green island in its west side, profitable for all city dwellers. This change will be a great improvement, not only for Toledo’s environment, but also for the development of different economical sectors. due to the golf course implantation.Se expone el estudio realizado sobre la incidencia ambiental de un futuro campo de golf en Toledo

  14. Peran Pemerintah dalam Perencanaan Pembangunan Lapangan Golf Kintamani dengan Prinsip Pariwisata Berkelanjutan

    Directory of Open Access Journals (Sweden)

    Rila Hilma

    2013-05-01

    Full Text Available Planning a tourist destination, some aspects need to be considered concerning government’s role, surrounding society, and sustainable development principles. The project of golf court in caldera Gunung Batur must be analysed by some experts. This study aims to anticipate some new troubles that might come up when the construction of golf court begins. Above it all, every study has opportunity to be applied whether by regional or national government, who responsibly takes control of the region, once they approved the project. Based on it, the plan of golf court construction in Kintamani, Bangli regency, Bali Province (as cited by www.bisnisbali.com on 27th January 2011 proposed by Ministre Jero Wacik and approved by the parlement members of DPRD Bangli, concerns the principles of sustainable tourism which could prevent, especially Kintamani region, from deconstructed side effects of the development. This research applies qualitative-descriptive method supported by literature review and news from media, especially online media which are able to provide the actual news from Kintamani region.

  15. Casimir Energies for Isorefractive or Diaphanous Balls

    Directory of Open Access Journals (Sweden)

    Kimball A. Milton

    2018-03-01

    Full Text Available It is known that the Casimir self-energy of a homogeneous dielectric ball is divergent, although a finite self-energy can be extracted through second order in the deviation of the permittivity from the vacuum value. The exception occurs when the speed of light inside the spherical boundary is the same as that outside, so the self-energy of a perfectly conducting spherical shell is finite, as is the energy of a dielectric-diamagnetic sphere with ε μ = 1 , a so-called isorefractive or diaphanous ball. Here we re-examine that example and attempt to extend it to an electromagnetic δ -function sphere, where the electric and magnetic couplings are equal and opposite. Unfortunately, although the energy expression is superficially ultraviolet finite, additional divergences appear that render it difficult to extract a meaningful result in general, but some limited results are presented.

  16. Relative locality and the soccer ball problem

    International Nuclear Information System (INIS)

    Amelino-Camelia, Giovanni; Freidel, Laurent; Smolin, Lee; Kowalski-Glikman, Jerzy

    2011-01-01

    We consider the behavior of macroscopic bodies within the framework of relative locality [G. Amelino-Camelia, L. Freidel, J. Kowalski-Glikman, and L. Smolin, arXiv:1101.0931]. This is a recent proposal for Planck scale modifications of the relativistic dynamics of particles which are described as arising from deformations in the geometry of momentum space. We consider and resolve a common objection against such proposals, which is that, even if the corrections are small for elementary particles in current experiments, they are huge when applied to composite systems such as soccer balls, planets, and stars, with energies E macro much larger than M P . We show that this soccer ball problem does not arise within the framework of relative locality because the nonlinear effects for the dynamics of a composite system with N elementary particles appear at most of order E macro /N·M P .

  17. Ball-thrower's fracture of the humerus

    International Nuclear Information System (INIS)

    Callaghan, Eric B.; Bennett, D. Lee; El-Khoury, Georges Y.; Ohashi, Kenjirou

    2004-01-01

    A relatively rare case of ball-thrower's fracture of the humerus is presented. Severe muscular action is an uncommon cause of humeral fractures but has been well documented in the orthopedic literature. To our knowledge, this fracture has not been described in the radiology literature, and awareness of this entity could preclude further unnecessary workup. The mechanism of injury and its typical radiographic appearance is described. (orig.)

  18. From a Ball Game to Incompleteness

    Indian Academy of Sciences (India)

    tree is a tree in which each node has a finite number of children. In a rooted tree, the sequence of nodes from the root to a leaf, where the (j + 1)th node is a child of the jth node, is called a. 'path'. For instance, in the above tree, the root contains 2, and all leafs are the nodes that contain 0. Since any ball is replaced with a fi-.

  19. CVD carbon powders modified by ball milling

    Directory of Open Access Journals (Sweden)

    Kazmierczak Tomasz

    2015-09-01

    Full Text Available Carbon powders produced using a plasma assisted chemical vapor deposition (CVD methods are an interesting subject of research. One of the most interesting methods of synthesizing these powders is using radio frequency plasma. This method, originally used in deposition of carbon films containing different sp2/sp3 ratios, also makes possible to produce carbon structures in the form of powder. Results of research related to the mechanical modification of these powders have been presented. The powders were modified using a planetary ball mill with varying parameters, such as milling speed, time, ball/powder mass ratio and additional liquids. Changes in morphology and particle sizes were measured using scanning electron microscopy and dynamic light scattering. Phase composition was analyzed using Raman spectroscopy. The influence of individual parameters on the modification outcome was estimated using statistical method. The research proved that the size of obtained powders is mostly influenced by the milling speed and the amount of balls. Powders tend to form conglomerates sized up to hundreds of micrometers. Additionally, it is possible to obtain nanopowders with the size around 100 nm. Furthermore, application of additional liquid, i.e. water in the process reduces the graphitization of the powder, which takes place during dry milling.

  20. 3D Printing of Ball Grid Arrays

    Science.gov (United States)

    Sinha, Shayandev; Hines, Daniel; Dasgupta, Abhijit; Das, Siddhartha

    Ball grid arrays (BGA) are interconnects between an integrated circuit (IC) and a printed circuit board (PCB), that are used for surface mounting electronic components. Typically, lead free alloys are used to make solder balls which, after a reflow process, establish a mechanical and electrical connection between the IC and the PCB. High temperature processing is required for most of these alloys leading to thermal shock causing damage to ICs. For producing flexible circuits on a polymer substrate, there is a requirement for low temperature processing capabilities (around 150 C) and for reducing strain from mechanical stresses. Additive manufacturing techniques can provide an alternative methodology for fabricating BGAs as a direct replacement for standard solder bumped BGAs. We have developed aerosol jet (AJ) printing methods to fabricate a polymer bumped BGA. As a demonstration of the process developed, a daisy chain test chip was polymer bumped using an AJ printed ultra violet (UV) curable polymer ink that was then coated with an AJ printed silver nanoparticle laden ink as a conducting layer printed over the polymer bump. The structure for the balls were achieved by printing the polymer ink using a specific toolpath coupled with in-situ UV curing of the polymer which provided good control over the shape, resulting in well-formed spherical bumps on the order of 200 um wide by 200 um tall for this initial demonstration. A detailed discussion of the AJ printing method and results from accelerated life-time testing will be presented

  1. Relation Between Hertz Stress-Life Exponent, Ball-Race Conformity, and Ball Bearing Life

    Science.gov (United States)

    Zaretsky, Erwin V.; Poplawski, Joseph V.; Root, Lawrence E.

    2008-01-01

    ANSI/ABMA and ISO standards based on Lundberg-Palmgren bearing life theory are normalized for ball bearings having inner- and outerrace conformities of 52 percent (0.52) and made from pre-1940 bearing steel. The Lundberg-Palmgren theory incorporates an inverse 9th power relation between Hertz stress and fatigue life for ball bearings. The effect of race conformity on ball set life independent of race life is not incorporated into the Lundberg-Palmgren theory. In addition, post-1960 vacuum-processed bearing steel exhibits a 12th power relation between Hertz stress and life. The work reported extends the previous work of Zaretsky, Poplawski, and Root to calculate changes in bearing life--that includes the life of the ball set--caused by race conformity, Hertz stress-life exponent, ball bearing type and bearing series. The bearing fatigue life in actual application will usually be equal to or greater than that calculated using the ANSI/ABMA and ISO standards that incorporate the Lundberg-Palmgren theory. The relative fatigue life of an individual race is more sensitive to changes in race conformity for Hertz stress-life exponent n of 12 than where n = 9. However, when the effects are combined to predict actual bearing life for a specified set of conditions and bearing geometry, the predicted life of the bearing will be greater for a value of n = 12 than n = 9.

  2. Aerodynamics in the classroom and at the ball park

    Science.gov (United States)

    Cross, Rod

    2012-04-01

    Experiments suitable for classroom projects or demonstrations are described concerning the aerodynamics of polystyrene balls. A light ball with sufficient backspin can curve vertically upward through the air, defying gravity and providing a dramatic visual demonstration of the Magnus effect. A ball projected with backspin can also curve downward with a vertical acceleration greater than that due to gravity if the Magnus force is negative. These effects were investigated by filming the flight of balls projected in an approximately horizontal direction so that the lift and drag forces could be easily measured. The balls were also fitted with artificial raised seams and projected with backspin toward a vertical target in order to measure the sideways deflection over a known horizontal distance. It was found that (a) a ball with a seam on one side can deflect either left or right depending on its launch speed and (b) a ball with a baseball seam can also deflect sideways even when there is no sideways component of the drag or lift forces acting on the ball. Depending on the orientations of the seam and the spin axis, a sideways force on a baseball can arise either if there is rough patch on one side of the ball or if there is a smooth patch. A scuff ball with a rough patch on one side is illegal in baseball. The effect of a smooth patch is a surprising new observation.

  3. Biomechanics of Heading a Soccer Ball: Implications for Player Safety

    Directory of Open Access Journals (Sweden)

    Charles F. Babbs

    2001-01-01

    Full Text Available To better understand the risk and safety of heading a soccer ball, the author created a set of simple mathematical models based upon Newton�s second law of motion to describe the physics of heading. These models describe the player, the ball, the flight of the ball before impact, the motion of the head and ball during impact, and the effects of all of these upon the intensity and the duration of acceleration of the head. The calculated head accelerations were compared to those during presumably safe daily activities of jumping, dancing, and head nodding and also were related to established criteria for serious head injury from the motor vehicle crash literature. The results suggest heading is usually safe but occasionally dangerous, depending on key characteristics of both the player and the ball. Safety is greatly improved when players head the ball with greater effective body mass, which is determined by a player�s size, strength, and technique. Smaller youth players, because of their lesser body mass, are more at risk of potentially dangerous headers than are adults, even when using current youth size balls. Lower ball inflation pressure reduces risk of dangerous head accelerations. Lower pressure balls also have greater “touch” and “playability”, measured in terms of contact time and contact area between foot and ball during a kick. Focus on teaching proper technique, the re-design of age-appropriate balls for young players with reduced weight and inflation pressure, and avoidance of head contact with fast, rising balls kicked at close range can substantially reduce risk of subtle brain injury in players who head soccer balls.

  4. A general theory for ball lightning structure and light output

    Science.gov (United States)

    Morrow, R.

    2018-03-01

    A general theory for free-floating ball lightning is presented which unifies the phantom plasma ball theory involving the production of very little light, with theories for ball lightning involving light output produced by burning particles from the soil. The mechanism for the formation of plasma balls is shown to be quite general, producing very similar plasma balls independent of initial ion densities over four orders of magnitude. All that is required is an excess of positive ions in the initial ball of ions. The central plasma density after 1 s is shown to be the reciprocal of the ion neutralization coefficient for all cases, both analytically and computationally. Further, the plasma region has zero electric field in all cases. Surrounding the plasma ball is a sphere of positive ions moving away from the centre via their own space-charge field; this space-charge field, which is the same in all cases near the plasma ball, drives negative ions and negative particles towards the plasma centre. The connection with burning particle theories is the proposition that the burning particles are highly-charged which is very likely after a lightning strike. Burning negatively charged particles would be driven into the plasma ball region and trapped while any positively charged particles would be driven away. The plasma ball structure is shown to last more than 10 s and the ‘burnout time’ for a typical coal particle (as an example) has been measured at 5-10 s this is comparable with the lifetimes observed for ball lightning. The light output from a few hundred particles is estimated to be ~1 W, a typical output for ball lightning. Finally, suggestions are made for the generation of ball lightning in the laboratory.

  5. Occurrence of Meloidogyne fallax in North America, and molecular characterization of M. fallax and M. minor from U.S. golf course greens

    Science.gov (United States)

    Several species of root-knot nematodes (Meloidogyne spp.) are known to have significant presence on turf grass in golf course greens, particularly in the western United States. Nematodes isolated from a golf course in King Co., Washington were identified as Meloidogyne minor based on analysis of the...

  6. Mucormycosis (Mucor fungus ball) of the maxillary sinus.

    Science.gov (United States)

    Cho, Hang Sun; Yang, Hoon Shik; Kim, Kyung Soo

    2014-01-01

    A fungus ball is an extramucosal fungal proliferation that completely fills one or more paranasal sinuses and usually occurs as a unilateral infection. It is mainly caused by Aspergillus spp in an immunocompetent host, but some cases of paranasal fungal balls reportedly have been caused by Mucor spp. A Mucor fungus ball is usually found in the maxillary sinus and/or the sphenoid sinus and may be black in color. Patients with mucormycosis, or a Mucor fungal ball infection, usually present with facial pain or headache. On computed tomography, there are no pathognomonic findings that are conclusive for a diagnosis of mucormycosis. In this article we report a case of mucormycosis in a 56-year-old woman and provide a comprehensive review of the literature on the "Mucor fungus ball." To the best of our knowledge, 5 case reports (8 patients) have been published in which the fungus ball was thought to be caused by Mucor spp.

  7. LOW COMPRESSION TENNIS BALLS AND SKILL DEVELOPMENT

    Directory of Open Access Journals (Sweden)

    John Hammond

    2006-12-01

    Full Text Available Coaching aims to improve player performance and coaches have a number of coaching methods and strategies they use to enhance this process. If new methods and ideas can be determined to improve player performance they will change coaching practices and processes. This study investigated the effects of using low compression balls (LCBs during coaching sessions with beginning tennis players. In order to assess the effectiveness of LCBs on skill learning the study employed a quasi-experimental design supported by qualitative and descriptive data. Beginner tennis players took part in coaching sessions, one group using the LCBs while the other group used standard tennis balls. Both groups were administered a skills at the beginning of a series of coaching sessions and again at the end. A statistical investigation of the difference between pre and post-test results was carried out to determine the effect of LCBs on skill learning. Additional qualitative data was obtained through interviews, video capture and the use of performance analysis of typical coaching sessions for each group. The skill test results indicated no difference in skill learning when comparing beginners using the LCBs to those using the standard balls. Coaches reported that the LCBs appeared to have a positive effect on technique development, including aspects of technique that are related to improving power of the shot. Additional benefits were that rallies went on longer and more opportunity for positive reinforcement. In order to provide a more conclusive answer to the effects of LCBs on skill learning and technique development recommendations for future research were established including a more controlled experimental environment and larger sample sizes across a longer period of time

  8. The methodology of composing the exercises system with fit balls.

    Directory of Open Access Journals (Sweden)

    Voronov N.P.

    2011-02-01

    Full Text Available The original methodology of composing the exercises system with fit balls was considered. More than 10 publications were analysed. On the lesson with fit balls the problem was revealed. In the experiment took part 30 students at the age from 18 till 21. All the famous exercises were systematized. As a result, a big attractiveness and assimilability of the proposed complex was revealed. The effectiveness of the complex of physical exercises with fit balls for students was proved.

  9. Random power series in the unit ball of Cn

    International Nuclear Information System (INIS)

    Shi Jihuai.

    1989-07-01

    The random power series in the unit disc has been studied by many authors. In this paper, we studied the random power series in the unit ball of C n and generalized some results in the unit disc to the unit ball, in particular, the result obtained recently by Duren has been generalized to the unit ball. The main tool used here is the generalized Salem-Zygmund's theorem. (author). 12 refs

  10. Amebiasis in four ball pythons, Python reginus.

    Science.gov (United States)

    Kojimoto, A; Uchida, K; Horii, Y; Okumura, S; Yamaguch, R; Tateyama, S

    2001-12-01

    Between September 13th and November 18th in 1999, four ball pythons, Python reginus kept in the same display, showed anorexia and died one after another. At necropsy, all four snakes had severe hemorrhagic colitis. Microscopically, all snakes had severe necrotizing hemorrhagic colitis, in association with ameba-like protozoa. Some of the protozoa had macrophage-like morphology and others formed protozoal cysts with thickened walls. These protozoa were distributed throughout the wall in the large intestine. Based on the pathological findings, these snakes were infested with a member of Entamoeba sp., presumably with infection by Entamoeba invadens, the most prevalent type of reptilian amoebae.

  11. Collective flow measured with the Plastic Ball

    International Nuclear Information System (INIS)

    Ritter, H.G.; Gutbrod, H.H.; Kampert, K.H.; Kolb, B.; Poskanzer, A.M.; Schicker, R.; Schmidt, H.R.; Siemiarczuk, T.

    1989-08-01

    The experimental results from the Plastic Ball detector have contributed vastly to the understanding of the reaction mechanism of nuclear collisions at several hundred MeV per nucleon. The discovery of the collective flow phenomena (bounce-off of spectator fragments, side-splash in the reaction plane, and squeeze-out out of the reaction plane), as they were predicted by hydrodynamical models, has led to the experimental observation of compressed nuclear matter, which is a necessary condition before one can study the equation of state in detail and search for phase transitions at higher energies. 39 refs., 9 figs., 1 tab

  12. A proposed experiment on ball lightning model

    International Nuclear Information System (INIS)

    Ignatovich, Vladimir K.; Ignatovich, Filipp V.

    2011-01-01

    Highlights: → We propose to put a glass sphere inside an excited gas. → Then to put a light ray inside the glass in a whispering gallery mode. → If the light is resonant to gas excitation, it will be amplified at every reflection. → In ms time the light in the glass will be amplified, and will melt the glass. → A liquid shell kept integer by electrostriction forces is the ball lightning model. -- Abstract: We propose an experiment for strong light amplification at multiple total reflections from active gaseous media.

  13. Quenching simulation of steel grinding balls

    Energy Technology Data Exchange (ETDEWEB)

    Zapata-Hernandez, O.; Reyes, L. A.; Camurri, C.; Carrasco, C.; Garza-Monte-de-Oca, F.; Colas, R.

    2015-07-01

    The phase transformations of high carbon steel during quenching and equalizing were modelled using commercial computer packages based on the finite element method and the kinetic transformation of steel. The model was used to predict the temperature and microstructural changes taking place within balls of two different sizes that are used for grinding mineral ores. A good correlation between the temperatures measured by inserted thermocouples and those predicted by the model was obtained after modifying the thermal conductivity of the steel within the temperature domain at which mixed phases are present. The phase transformations predicted were confirmed by metallographic analyses. (Author)

  14. Crystal Ball evidence for new states

    International Nuclear Information System (INIS)

    Coyne, D.G.

    1981-09-01

    Evidence for three new particles observed in the Crystal Ball detector is presented. The first particle, at 3592 MeV, is seen inclusively in γ transitions from psi', and is thus a candidate for eta/sub c/'. The other two, at 1440 and 1640 MeV, are best seen in exclusive decays of psi involving a prompt γ, and are thus candidates for bound states of two gluons. Detailed reasons are presented to support the contention that these states are distinct from previously observed candidates such as E(1420). Alternative hypotheses are discussed

  15. Results on charmonium from the Crystal Ball

    CERN Document Server

    Partridge, R; Bloom, Elliott D; Bulos, F; Burnett, T; Cavalli-Sforza, M; Chestnut, R; Coyne, D; Gaiser, J; Godfrey, G; Hofstadter, R; Kiesling, C; Kirkbride, I; Kolanoski, H; Kollmann, W; Liberman, A; O'Reilly, J; Oreglia, M J; Peck, C; Porter, F; Richardson, M; Sadrozinski, H F W; Strauch, K; Tompkins, J; Wacker, K

    1979-01-01

    Results from the Crystal Ball experiment at SPEAR are presented. A preliminary analysis of the 3 photon final state from the J/ psi (3095) and of the cascade decays of the psi '(3684) yield new upper limits on the controversial states X(2820), chi (3455) and the even C- parity state at 3.59 GeV. From inclusive gamma -ray spectra of the J/ psi and psi ' preliminary branching ratios for psi ' to chi states and upper limits for J/ psi , psi ' to eta /sub c/, eta /sub c/' are given. (15 refs).

  16. Ball Bearing Analysis with the ORBIS Tool

    Science.gov (United States)

    Halpin, Jacob D.

    2016-01-01

    Ball bearing design is critical to the success of aerospace mechanisms. Key bearing performance parameters, such as load capability, stiffness, torque, and life all depend on accurate determination of the internal load distribution. Hence, a good analytical bearing tool that provides both comprehensive capabilities and reliable results becomes a significant asset to the engineer. This paper introduces the ORBIS bearing tool. A discussion of key modeling assumptions and a technical overview is provided. Numerous validation studies and case studies using the ORBIS tool are presented. All results suggest the ORBIS code closely correlates to predictions on bearing internal load distributions, stiffness, deflection and stresses.

  17. Simulation of ball motion and energy transfer in a planetary ball mill

    International Nuclear Information System (INIS)

    Lu Sheng-Yong; Mao Qiong-Jing; Li Xiao-Dong; Yan Jian-Hua; Peng Zheng

    2012-01-01

    A kinetic model is proposed for simulating the trajectory of a single milling ball in a planetary ball mill, and a model is also proposed for simulating the local energy transfer during the ball milling process under no-slip conditions. Based on the kinematics of ball motion, the collision frequency and power are described, and the normal impact forces and effective power are derived from analyses of collision geometry. The Hertzian impact theory is applied to formulate these models after having established some relationships among the geometric, dynamic, and thermophysical parameters. Simulation is carried out based on two models, and the effects of the rotation velocity of the planetary disk Ω and the vial-to-disk speed ratio ω/Ω on other kinetic parameters is investigated. As a result, the optimal ratio ω/Ω to obtain high impact energy in the standard operating condition at Ω = 800 rpm is estimated, and is equal to 1.15. (interdisciplinary physics and related areas of science and technology)

  18. Respiratory disease in ball pythons (Python regius) experimentally infected with ball python nidovirus.

    Science.gov (United States)

    Hoon-Hanks, Laura L; Layton, Marylee L; Ossiboff, Robert J; Parker, John S L; Dubovi, Edward J; Stenglein, Mark D

    2018-04-01

    Circumstantial evidence has linked a new group of nidoviruses with respiratory disease in pythons, lizards, and cattle. We conducted experimental infections in ball pythons (Python regius) to test the hypothesis that ball python nidovirus (BPNV) infection results in respiratory disease. Three ball pythons were inoculated orally and intratracheally with cell culture isolated BPNV and two were sham inoculated. Antemortem choanal, oroesophageal, and cloacal swabs and postmortem tissues of infected snakes were positive for viral RNA, protein, and infectious virus by qRT-PCR, immunohistochemistry, western blot and virus isolation. Clinical signs included oral mucosal reddening, abundant mucus secretions, open-mouthed breathing, and anorexia. Histologic lesions included chronic-active mucinous rhinitis, stomatitis, tracheitis, esophagitis and proliferative interstitial pneumonia. Control snakes remained negative and free of clinical signs throughout the experiment. Our findings establish a causal relationship between nidovirus infection and respiratory disease in ball pythons and shed light on disease progression and transmission. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  19. CFD Analysis of Swing of Cricket Ball and Trajectory Prediction

    Science.gov (United States)

    G, Jithin; Tom, Josin; Ruishikesh, Kamat; Jose, Jyothish; Kumar, Sanjay

    2013-11-01

    This work aims to understand the aerodynamics associated with the flight and swing of a cricket ball and predict its flight trajectory over the course of the game: at start (smooth ball) and as the game progresses (rough ball). Asymmetric airflow over the ball due to seam orientation and surface roughness can cause flight deviation (swing). The values of Drag, Lift and Side forces which are crucial for determining the trajectory of the ball were found with the help of FLUENT using the standard K- ɛ model. Analysis was done to study how the ball velocity, spin imparted to be ball and the tilt of the seam affects the movement of the ball through air. The governing force balance equations in 3 dimensions in combination a MATLAB code which used Heun's method was used for obtaining the trajectory of the ball. The conditions for the conventional swing and reverse swing to occur were deduced from the analysis and found to be in alignment with the real life situation. Critical seam angle for maximum swing and transition speed for normal to reverse swing were found out. The obtained trajectories were compared to real life hawk eye trajectories for validation. The analysis results were in good agreement with the real life situation.

  20. Two Balls' Collision of Mass Ratio 3:1

    Science.gov (United States)

    Ogawara, Yasuo; Hull, Michael M.

    2018-04-01

    Students will sometimes ask why momentum and kinetic energy concepts are both necessary. When physics teachers demonstrate situations that require both an understanding of kinetic energy and momentum, a favorite is Newton's cradle, or a comparable demonstration of two balls of equal mass hitting each other. However, in addition to the case of two balls of equal mass, if a ball hits another ball of three times the mass with equal speed, the results are also interesting, and, like the equal-mass demonstration, both kinetic energy and momentum are critical for understanding the motion.

  1. An early record of ball lightning: Oliva (Spain), 1619

    Science.gov (United States)

    Domínguez-Castro, Fernando

    2018-05-01

    In a primary documentary source we found an early record of ball lightning (BL), which was observed in the monastery of Pi (Oliva, southeastern Spain) on 18 October 1619. The ball lightning was observed by at least three people and was described as a rolling burning vessel and a ball of fire. The ball lightning appeared following a lightning flash, showed a mainly horizontal motion, crossed a wall, smudged an image of the Lady of Rebollet (then known as Lady of Pi) and burnt her ruff, and overturned a cross.

  2. How does gravity save or kill Q-balls?

    OpenAIRE

    Tamaki, Takashi; Sakai, Nobuyuki

    2011-01-01

    We explore stability of gravitating Q-balls with potential $V_4(\\phi)={m^2\\over2}\\phi^2-\\lambda\\phi^4+\\frac{\\phi^6}{M^2}$ via catastrophe theory, as an extension of our previous work on Q-balls with potential $V_3(\\phi)={m^2\\over2}\\phi^2-\\mu\\phi^3+\\lambda\\phi^4$. In flat spacetime Q-balls with $V_4$ in the thick-wall limit are unstable and there is a minimum charge $Q_{{\\rm min}}$, where Q-balls with $Q

  3. Does the transparency of the websites can help in attracting customers? Analysis of the golf courses in Andalusia

    Directory of Open Access Journals (Sweden)

    Marta García-Tascón

    2016-06-01

    Full Text Available Purpose: The aim of this study is to analyze the degree of transparency of the Web pages of organizations that belong to the world of sports, specifically golf courses in Andalusia. Design/methodology/approach: We performed a descriptive analysis of the conditions of transparency of 92 Web pages of golf clubs registered on the official website of the Royal Golf Federation of Andalusia (RFGA. A questionnaire created/adapted ad hoc is used for this study having as a reference the questionnaire used by Barrio and Martin (2012 that analyze the performance of the 4 conditions of transparency of Web pages. Findings: To reflect a high degree of transparency, they show a higher compliance than 75% in 8 of the 10 variables. The Web page becomes an element to quantify the performance of the field without investing too much in other promotional channels to attract as many customers as possible. Research limitations: In some Web pages, the access to information entailed a significant investment of time because they did not have the characteristic of being intuitive. In some cases was not available all required information. Practical implications: Knowledge of this information allows the director or manager identifies possible areas of improvement to optimize their management, while transparency offered by the golf courses is improved. Social implications: This study highlights the need for teaching the user to evaluate the quality, transparency and being critical with the information found on Web pages. Originality/value: The analysis of transparency allows clubs to be reflective of its golf courses. It becomes the tool that the manager can use to display part of all its virtues and to evaluate the social behavior of their customers, to attract possible clients and perform actions with the stakeholders in the golf industry.

  4. Report of ground water monitoring for expansion of the golf course, Salt Lake City, Utah, vitro processing site

    International Nuclear Information System (INIS)

    1995-06-01

    To determine the potential impacts of the proposed golf course expansion on the south side of the Vitro site, ground water data from the UMTRA Vitro processing site were evaluated in response to the U.S. Department of Energy (DOE) Uranium Mill Tailings Remedial Action (UMTRA) Project Office request. Golf in the Round, Inc., has proposed an expansion of the present driving range to include a 9-hole golf course on the UMTRA Vitro processing site, which is owned by the Central Valley Water Reclamation Facility (CVWRF). An expanded golf course would increase irrigation and increase the amount of water that could infiltrate the soil, recharging the unconfined aquifer. Increased water levels in the aquifer could alter the ground water flow regime; contaminants in the shallow ground water could then migrate off the site or discharge to surface water in the area. Dewatering of the unconfined aquifer on CVWRF property could also impact site contaminant migration; a significant amount of ground water extraction at CVWRF could reduce the amount of contaminant migration off the site. Since 1978, data have been collected at the site to determine the distribution of tailings materials (removed from the site from 1985 to 1987) and to characterize the presence and migration of contaminants in sediments, soils, surface water, and ground water at the former Vitro processing site. Available data suggest that irrigating an expanded golf course may cause contamination to spread more rapidly within the unconfined aquifer. The public is not at risk from current Vitro processing site activities, nor is risk expected due to golf course expansion. However, ecological risk could increase with increased surface water contamination and the development of ground water seeps

  5. The relationship and effects of golf on physical and mental health: a scoping review protocol.

    Science.gov (United States)

    Murray, A; Daines, L; Archibald, D; Hawkes, R; Grant, L; Mutrie, N

    2016-06-01

    Golf is a sport played in 206 countries worldwide by over 50 million people. It is possible that participation in golf, which is a form of physical activity, may be associated with effects on longevity, the cardiovascular, metabolic and musculoskeletal systems, as well as on mental health and well-being. We outline our scoping review protocol to examine the relationships and effects of golf on physical and mental health. Best practice methodological frameworks suggested by Arksey and O'Malley, Levac et al and the Joanna Briggs Institute will serve as our guide, providing clarity and rigour. A scoping review provides a framework to (1) map the key concepts and evidence, (2) summarise and disseminate existing research findings to practitioners and policymakers and (3) identify gaps in the existing research. A three-step search strategy will identify reviews as well as original research, published and grey literature. An initial search will identify suitable search terms, followed by a search using keyword and index terms. Two reviewers will independently screen identified studies for final inclusion. We will map key concepts and evidence, and disseminate existing research findings to practitioners and policymakers through peer-reviewed and non-peer reviewed publications, conferences and in-person communications. We will identify priorities for further study. This method may prove useful to examine the relationships and effects of other sports on health. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  6. Evaluating management-induced soil salinization in golf courses in semi-arid landscapes

    Science.gov (United States)

    Young, J.; Udeigwe, T. K.; Weindorf, D. C.; Kandakji, T.; Gautam, P.; Mahmoud, M. A.

    2015-04-01

    Site-specific information on land management practices are often desired to make better assessments of their environmental impacts. A study was conducted in Lubbock, Texas, in the Southern High Plains of the United States, an area characterized by semi-arid climatic conditions, to (1) examine the potential management-induced alterations in soil salinity indicators in golf course facilities and (2) develop predictive relationships for a more rapid soil salinity examination within these urban landscape soils using findings from a portable X-ray fluorescence (PXRF) spectrometer. Soil samples were collected from managed (well irrigated) and non-managed (non-irrigated) areas of seven golf course facilities at 0-10, 10-20, and 20-30 cm depths and analyzed for a suite of chemical properties. Among the extractable cations, sodium (Na) was significantly (p golf facilities. Soil electrical conductivity (EC), exchangeable sodium percentage (ESP), and sodium adsorption ratio (SAR), parameters often used in characterizing soil salinity and sodicity, were for the most part significantly (p < 0.05) higher in the managed areas. Water quality reports collected over a 22-year period (1991-2013, all years not available) indicated a gradual increase in pH, EC, SAR, total alkalinity, and extractable ions, thus supporting the former findings. Findings from the PXRF suggested possible differences in chemical species and sources that contribute to salinity between the managed and non-managed zones. PXRF-quantified Cl and S, and to a lesser extent Ca, individually and collectively explained 23-85% of the variability associated with soil salinity at these facilities.

  7. James Moores Ball: Ophthalmologist, medical historian, bibliophile.

    Science.gov (United States)

    Feibel, Robert M

    2016-08-01

    James Moores Ball (1862-1929) was an ophthalmologist in St. Louis, Missouri, who excelled as a medical historian and collector of rare and historic books about the history of anatomy. During his lifetime, he was best known as the author of a comprehensive, authoritative, and popular textbook titled Modern Ophthalmology First published in 1904, there were five further editions. Ball was very interested in the history of anatomy and wrote two books on this subject, the first being a biography of Andreas Vesalius, one of the earliest in English, and the second a history of the resurrection men or grave robbers who sold corpses to professors of anatomy and surgery for teaching purposes. His legacy today is the 470 volumes of his personal library, which are now in the Archives and Rare Books department of the Becker Medical Library of the Washington University School of Medicine. These texts are one of their major collections, concentrating on the history of anatomy, beginning with a first edition of Vesalius's De Humani Corporis Fabrica and holding many important and beautiful landmark volumes of anatomical atlases. © The Author(s) 2016.

  8. Crises in a dissipative bouncing ball model

    Energy Technology Data Exchange (ETDEWEB)

    Livorati, André L.P., E-mail: livorati@usp.br [Departamento de Física, UNESP, Universidade Estadual Paulista, Av. 24A, 1515, Bela Vista, 13506-900, Rio Claro, SP (Brazil); School of Mathematics, University of Bristol, Bristol, BS8 1TW (United Kingdom); Instituto de Física, IFUSP, Universidade de São Paulo, USP, Rua do Matão, Tr.R 187, Cidade Universitária, 05314-970, São Paulo, SP (Brazil); Caldas, Iberê L. [Instituto de Física, IFUSP, Universidade de São Paulo, USP, Rua do Matão, Tr.R 187, Cidade Universitária, 05314-970, São Paulo, SP (Brazil); Dettmann, Carl P. [School of Mathematics, University of Bristol, Bristol, BS8 1TW (United Kingdom); Leonel, Edson D. [Departamento de Física, UNESP, Universidade Estadual Paulista, Av. 24A, 1515, Bela Vista, 13506-900, Rio Claro, SP (Brazil)

    2015-11-06

    Highlights: • We studied a dissipative bouncing ball dynamics. • A two-dimensional nonlinear mapping describes the dynamics. • Crises between attractors and its manifolds were characterized. • A new physical crisis between vibrating platform and an attractor was characterized. • The existence of a ‘robust’ chaotic attractor was set. - Abstract: The dynamics of a bouncing ball model under the influence of dissipation is investigated by using a two-dimensional nonlinear mapping. When high dissipation is considered, the dynamics evolves to different attractors. The evolution of the basins of the attracting fixed points is characterized, as we vary the control parameters. Crises between the attractors and their boundaries are observed. We found that the multiple attractors are intertwined, and when the boundary crisis between their stable and unstable manifolds occurs, it creates a successive mechanism of destruction for all attractors originated by the sinks. Also, a physical impact crisis is described, an important mechanism in the reduction of the number of attractors.

  9. Croissance relative, sex-ratio et exploitation de la crevette blanche metapenaeus monoceros (fabricius, 1798) du golfe de gabes (tunisie)

    OpenAIRE

    Jarboui, O.; Ben Abdallah, O.; Missaoui, H.; Ben Hadj Hamida, N.

    2003-01-01

    Les crevettes, particulièrement Penaeus kerathurus, sont considérées parmi les espèces de crustacés les plus exploitées au niveau des côtes tunisiennes, essentiellement dans le golfe de Gabès. Depuis l’année 1993, une nouvelle espèce de crevette d’origine lesseptienne est apparue dans le golfe et s’est bien adaptée avec ses conditions climatiques et environnementales : c’est la crevette blanche Metapenaeus monoceros. L’objectif principal de cette étude consiste à suivre l’exploitation de cett...

  10. Integrated dynamic policy management methodology and system for strategic environmental assessment of golf course installation policy in Taiwan

    International Nuclear Information System (INIS)

    Chen, Ching-Ho; Liu, Wei-Lin; Liaw, Shu-Liang

    2011-01-01

    Strategic environmental assessment (SEA) focuses primarily on assessing how policies, plans, and programs (PPPs) influence the sustainability of the involved regions. However, the processes of assessing policies and developing management strategies for pollution load and resource use are usually separate in the current SEA system. This study developed a policy management methodology to overcome the defects generated during the above processes. This work first devised a dynamic management framework using the methods of systems thinking, system dynamics, and Managing for Results (MFRs). Furthermore, a driving force-pressure-state-impact-response (DPSIR) indicator system was developed. The golf course installation policy was applied as a case study. Taiwan, counties of Taiwan, and the golf courses within those individual counties were identified as a system, subsystems, and objects, respectively. This study identified an object-linked double-layer framework with multi-stage-option to simultaneously to quantify golf courses in each subsystem and determine ratios of abatement and allocation for pollution load and resource use of each golf course. The DPSIR indicator values for each item of each golf course in each subsystem are calculated based on the options taken in the two decision layers. The summation of indicator values for all items of all golf courses in all subsystems according to various options is defined as the sustainability value of the policy. An optimization model and a system (IDPMS) were developed to obtain the greatest sustainability value of the policy, while golf course quantity, human activity intensity, total quantities of pollution load and resource use are simultaneously obtained. The solution method based on enumeration of multiple bounds for objectives and constraints (EMBOC) was developed for the problem with 1.95 x 10 128 combinations of possible options to solve the optimal solution in ten minutes using a personal computer with 3.0 GHz CPU

  11. Structural evolution of Ni-20Cr alloy during ball milling of elemental powders

    International Nuclear Information System (INIS)

    Lopez B, I.; Trapaga M, L. G.; Martinez F, E.; Zoz, H.

    2011-01-01

    The ball milling (B M) of blended Ni and Cr elemental powders was carried out in a Simoloyer performing on high-energy scale mode at maximum production to obtain a nano structured Ni-20Cr alloy. The phase transformations and structural changes occurring during mechanical alloying were investigated by X-ray diffraction (XRD) and optical microscopy (Om). A gradual solid solubility of Cr and the subsequent formation of crystalline metastable solid solutions described in terms of the Avrami-Ero fe ev kinetics model were calculated. The XRD analysis of the structure indicates that cumulative lattice strain contributes to the driving force for solid solution between Ni and Cr during B M. Microstructure evolution has shown, additionally to the lamellar length refinement commonly observed, the folding of lamellae in the final processing stage. Om observations revealed that the lamellar spacing of Ni rich zones reaches a steady value near 500 nm and almost disappears after 30 h of milling. (Author)

  12. Structural evolution of Ni-20Cr alloy during ball milling of elemental powders

    Energy Technology Data Exchange (ETDEWEB)

    Lopez B, I.; Trapaga M, L. G. [IPN, Centro de Investigacion y de Estudios Avanzados, Unidad Queretaro, Libramiento Norponiente No. 2000, Juriquilla, 76230 Queretaro (Mexico); Martinez F, E. [Centro de Investigacion e Innovacion Tecnologica, Cerrada de Cecati s/n, Col. Santa Catarina Azcapotzalco, 02250 Mexico D. F. (Mexico); Zoz, H., E-mail: israelbaez@gmail.co [Zoz GmbH, D-57482, Wenden (Germany)

    2011-07-01

    The ball milling (B M) of blended Ni and Cr elemental powders was carried out in a Simoloyer performing on high-energy scale mode at maximum production to obtain a nano structured Ni-20Cr alloy. The phase transformations and structural changes occurring during mechanical alloying were investigated by X-ray diffraction (XRD) and optical microscopy (Om). A gradual solid solubility of Cr and the subsequent formation of crystalline metastable solid solutions described in terms of the Avrami-Ero fe ev kinetics model were calculated. The XRD analysis of the structure indicates that cumulative lattice strain contributes to the driving force for solid solution between Ni and Cr during B M. Microstructure evolution has shown, additionally to the lamellar length refinement commonly observed, the folding of lamellae in the final processing stage. Om observations revealed that the lamellar spacing of Ni rich zones reaches a steady value near 500 nm and almost disappears after 30 h of milling. (Author)

  13. Fabrication of Ti-Ni-Cu shape memory alloy powders by ball milling method

    International Nuclear Information System (INIS)

    Kang, S.; Nam, T.

    2001-01-01

    Ti-Ni and Ti-Ni-Cu shape memory alloy powders have been fabricated by ball milling method, and then alloying behavior and transformation behavior were investigated by means of optical microscopy, electron microscopy, X-ray diffraction and differential scanning calorimetry. As milled Ti-Ni powders fabricated with milling time less than 20 hrs was a mixture of pure elemental Ti and Ni, and therefore it was unable to obtain alloy powders because the combustion reaction between Ti and Ni occurred during heat treatment. Since those fabricated with milling time more than 20 hrs was a mixture of Ti-rich and Ni-rich Ti-Ni solid solution, however, it was possible to obtain alloy powders without the combustion reaction during heat treatment. Clear exothermic and endothermic peaks appeared in the cooling and heating curves, respectively in DSC curves of 20 hrs and 30 hrs milled Ti-Ni powders. On the other hand, in DSC curves of 1 hr, 10 hrs, 50 hrs and 100 hrs, the thermal peaks were almost discernible. The most optimum ball milling time for fabricating Ti-Ni alloy powders was 30 hrs. Ti-40Ni-10Cu(at%) alloy powders were fabricated successfully by ball milling conditions with rotating speed of 100 rpm and milling time of 30 hrs. (author)

  14. Modeling and Analyzing the Slipping of the Ball Screw

    Directory of Open Access Journals (Sweden)

    Nannan Xu

    Full Text Available AbstractThis paper aims to set up the ball systematic slipping model and analyze the slipping characteristics caused by different factors for a ball screw operating at high speeds. To investigate the ball screw slipping mechanism, transformed coordinate system should be established firstly. Then it is used to set up mathematical modeling for the ball slipping caused by the three main reasons and the speed of slipping can be calculated. Later, the influence of the contact angle, helix angle and screw diameter for ball screw slipping will be analyzed according to the ball slipping model and slipping speeds equation and the slipping analysis will be obtained. Finally, curve of slipping analysis and that of mechanical efficiency of the ball screw analysis by Lin are compared, which will indirectly verify the correctness of the slipping model. The slipping model and the curve of slipping analysis established in this paper will provide theory basis for reducing slipping and improving the mechanical efficiency of a ball screw operating at high speeds.

  15. Linearly convergent stochastic heavy ball method for minimizing generalization error

    KAUST Repository

    Loizou, Nicolas; Richtarik, Peter

    2017-01-01

    In this work we establish the first linear convergence result for the stochastic heavy ball method. The method performs SGD steps with a fixed stepsize, amended by a heavy ball momentum term. In the analysis, we focus on minimizing the expected loss

  16. Exact solutions, energy, and charge of stable Q-balls

    Energy Technology Data Exchange (ETDEWEB)

    Bazeia, D.; Marques, M.A. [Universidade Federal da Paraiba, Departamento de Fisica, Joao Pessoa, PB (Brazil); Menezes, R. [Universidade Federal da Paraiba, Departamento de Ciencias Exatas, Rio Tinto, PB (Brazil); Universidade Federal de Campina Grande, Departamento de Fisica, Campina Grande, PB (Brazil)

    2016-05-15

    In this work we deal with nontopological solutions of the Q-ball type in two spacetime dimensions. We study models of current interest, described by a Higgs-like and other, similar potentials which unveil the presence of exact solutions. We use the analytic results to investigate how to control the energy and charge to make the Q-balls stable. (orig.)

  17. Attempted - to -Phase Conversion of Croconic Acid via Ball Milling

    Science.gov (United States)

    2017-05-18

    ARL-TN-0824 MAY 2017 US Army Research Laboratory Attempted α- to β-Phase Conversion of Croconic Acid via Ball Milling by...Laboratory Attempted α- to β-Phase Conversion of Croconic Acid via Ball Milling by Steven W Dean, Rose A Pesce-Rodriguez, and Jennifer A Ciezak...

  18. Wear numbers for ball cup and journal bearings

    NARCIS (Netherlands)

    Ligterink, D.J.; Moes, H.

    1980-01-01

    A wear number is defined for ball cup bearings and for journal bearings where the cup and the cylindrical bearing are made of soft material. This dimensionless wear number provides a relation between the following five quantities: the radius of the ball or the length of the journal bearing in

  19. Between Traditions: Stephen Ball and the Critical Sociology of Education

    Science.gov (United States)

    Apple, Michael W.

    2013-01-01

    Stephen Ball's work has deservedly received a good deal of attention. In this article, I detail a number of tasks in which the critical sociologist of education--as a "public intellectual"--should engage. I then place Ball's work within these tasks and evaluate his contributions to them. In the process, I show that one of the…

  20. Launch Creativity with Ping-Pong Ball Challenge

    Science.gov (United States)

    Kornoelje, Joanne; Roman, Harry T.

    2011-01-01

    Educators at Thomas A. Edison Middle School have worked together to bring invention information and activities to life. One activity in particular, Ping-Pong Ball Invention Challenge, has proven a great success. The Ping-Pong Ball Invention Challenge was inspired by the basic rules for PBS's "Design Squad"'s "Pop Fly" activity. In this article,…

  1. Structure and magnetism of SmCo5 nanoflakes prepared by surfactant-assisted ball milling with different ball sizes

    International Nuclear Information System (INIS)

    Nie, Junwu; Han, Xianghua; Du, Juan; Xia, Weixing; Zhang, Jian; Guo, Zhaohui; Yan, Aru; Li, Wei; Ping Liu, J.

    2013-01-01

    Anisotropic magnetic SmCo 5 nanoflakes have been fabricated by surfactant-assisted ball milling (SABM) using hardened steel balls of one of the following sizes: 4, 6.5, 9.5 and 12.7 mm in diameters. The magnetic properties of SmCo 5 particles prepared by SABM with different milling ball sizes in diameters were investigated systematically. It was showed that the nanoflakes milled by amount of small size balls had a higher coercivity and lower anisotropy, i.e., worse grain orientation although in a short milling time while the nanoflakes prepared with same weight of big balls tend to have a lower coercivity, better grain orientation. The coercivity mechanism of the nanoflake was studied and it was mainly dominated with the domain-wall pinning. The SEM analysis shows that the morphology of nanoflakes prepared with different ball sizes are almost the same when the balls to powder weight ratio is fixed. The different magnetic properties caused by different ball sizes are mainly due to the different microstructure changes, i.e, grain refinement and c-axis orientation, which are demonstrated by X-ray diffraction (XRD) analysis and transmission electron microscope (TEM). Based on the experiments above, a combined milling process was suggested and done to improve magnetic properties as your need. - Highlights: • We fabricated anisotropic magnetic SmCo 5 nanoflakes by surfactant-assisted ball milling (SABM). • We investigated the magnetic properties of SmCo 5 particles systematically. It was showed that the coercivity, high or low, and grain orientation, good or bad, were influenced strongly by balls size. The different magnetisms caused by different ball sizes is mainly due to the different microstructure changes. • The coercivity mechanism of the nanoflake was studied and it was mainly dominated with the domain-wall pinning

  2. A systematic study of ball passing frequencies based on dynamic modeling of rolling ball bearings with localized surface defects

    Science.gov (United States)

    Niu, Linkai; Cao, Hongrui; He, Zhengjia; Li, Yamin

    2015-11-01

    Ball passing frequencies (BPFs) are very important features for condition monitoring and fault diagnosis of rolling ball bearings. The ball passing frequency on outer raceway (BPFO) and the ball passing frequency on inner raceway (BPFI) are usually calculated by two well-known kinematics equations. In this paper, a systematic study of BPFs of rolling ball bearings is carried out. A novel method for accurately calculating BPFs based on a complete dynamic model of rolling ball bearings with localized surface defects is proposed. In the used dynamic model, three-dimensional motions, relative slippage, cage effects and localized surface defects are all considered. Moreover, localized surface defects are modeled accurately with consideration of the finite size of the ball, the additional clearance due to material absence, and changes of contact force directions. The reasonability of the proposed method for the prediction of dynamic behaviors of actual ball bearings with localized surface defects and for the calculation of BPFs is discussed by investigating the motion characteristics of a ball when it rolls through a defect. Parametric investigation shows that the shaft speed, external loads, the friction coefficient, raceway groove curvature factors, the initial contact angle, and defect sizes have great effects on BPFs. For a loaded ball bearing, the combination of rolling and sliding in contact region occurs, and the BPFs calculated by simple kinematical relationships are inaccurate, especially for high speed, low external load, and large initial contact angle conditions where severe skidding occurs. The hypothesis that the percentage variation of the spacing between impulses in a defective ball bearing was about 1-2% reported in previous investigations can be satisfied only for the conditions where the skidding effect in a bearing is slight. Finally, the proposed method is verified with two experiments.

  3. Two balls and a string: from ordered motion to chaos

    International Nuclear Information System (INIS)

    Sacks, William; Mauger, Alain

    2013-01-01

    Two spherical balls are connected by a taught string passing through a small hole in a perfectly planar table: the first ball, subject to a central force, moves without friction on a two-dimensional plane, while the second ball moves only along the vertical axis directly below the hole. The pedagogical aspects of this novel two-body problem are given particular attention: Newton’s laws, central force motion, conservation laws, angular momentum, constraints, etc. The dynamics of the system is considered under various initial conditions wherein the ball on the table moves qualitatively in rotating ellipses or hypotrochoids. The conditions for closed or periodic orbits are examined. The more complex case of the inclined plane is then considered, revealing a rich variety of periodic, aperiodic and chaotic solutions as a function of the ball mass ratio and the plane inclination angle. The associated Poincaré phase-space maps are discussed. (paper)

  4. Friction torque in thrust ball bearings grease lubricated

    Science.gov (United States)

    Ianuş, G.; Dumitraşcu, A. C.; Cârlescu, V.; Olaru, D. N.

    2016-08-01

    The authors investigated experimentally and theoretically the friction torque in a modified thrust ball bearing having only 3 balls operating at low axial load and lubricated with NGLI-00 and NGLI-2 greases. The experiments were made by using spin-down methodology and the results were compared with the theoretical values based on Biboulet&Houpert's rolling friction equations. Also, the results were compared with the theoretical values obtained with SKF friction model adapted for 3 balls. A very good correlation between experiments and Biboulet_&_Houpert's predicted results was obtained for the two greases. Also was observed that the theoretical values for the friction torque calculated with SKF model adapted for a thrust ball bearing having only 3 balls are smaller that the experimental values.

  5. Ball Screw Actuator Including an Axial Soft Stop

    Science.gov (United States)

    Wingett, Paul T. (Inventor); Forrest, Steven Talbert (Inventor); Abel, Steve (Inventor); Woessner, George (Inventor); Hanlon, Casey (Inventor)

    2016-01-01

    An actuator includes an actuator housing, a ball screw, and an axial soft stop assembly. The ball screw extends through the actuator housing and has a first end and a second end. The ball screw is coupled to receive a drive force and is configured, upon receipt of the drive force, to selectively move in a retract direction and an extend direction. The axial soft stop assembly is disposed within the actuator housing. The axial soft stop assembly is configured to be selectively engaged by the ball screw and, upon being engaged thereby, to translate, with compliance, a predetermined distance in the extend direction, and to prevent further movement of the ball screw upon translating the predetermined distance.

  6. Stability of a Fermi ball against deformation from spherical shape

    International Nuclear Information System (INIS)

    Yoshida, T.; Ogure, K.; Arafune, J.

    2003-01-01

    The stability of a Fermi ball (F ball), which is a kind of nontopological soliton accompanying the breakdown of the approximate Z 2 symmetry, is investigated in three situations: when it is electrically neutral, when it is electrically charged and unscreened, and when it is electrically charged and screened. We argue only that the third case is physically meaningful since the neutral F ball is unstable and the case of an unscreened charged F ball is observationally excluded when it has a sizable contribution to CDM. We find that the energy scale of the breakdown of the approximate Z 2 symmetry v should satisfy v 6 GeV if the F ball is the main component of CDM

  7. Fabrication of lanthanum-doped thorium dioxide by high-energy ball milling and spark plasma sintering

    Energy Technology Data Exchange (ETDEWEB)

    Scott, Spencer M.; Yao, Tiankai [Department of Mechanical, Aerospace, and Nuclear Engineering, Rensselaer Polytechnic Institute, 110 8th Street, Troy, NY 12180 (United States); Lu, Fengyuan [Department of Mechanical & Industrial Engineering, Louisiana State University, Baton Rouge, LA 70803 (United States); Xin, Guoqing; Zhu, Weiguang [Department of Mechanical, Aerospace, and Nuclear Engineering, Rensselaer Polytechnic Institute, 110 8th Street, Troy, NY 12180 (United States); Lian, Jie, E-mail: lianj@rpi.edu [Department of Mechanical, Aerospace, and Nuclear Engineering, Rensselaer Polytechnic Institute, 110 8th Street, Troy, NY 12180 (United States)

    2017-03-15

    Abstract: High-energy ball milling was used to synthesize Th{sub 1-x}La{sub x}O{sub 2-0.5x} (x = 0.09, 0.23) solid solutions, as well as improve the sinterability of ThO{sub 2} powders. Dense La-doped ThO{sub 2} pellets with theoretical density above 94% were consolidated by spark plasma sintering at temperatures above 1400 °C for 20 min, and the densification behavior and the non-equilibrium effects on phase and structure were investigated. A lattice contraction of the SPS-densified pellets occurred with increasing ball milling duration, and a secondary phase with increased La-content was observed in La-doped pellets. A dependence on the La-content and sintering duration for the onset of localized phase segregation has been proposed. The effects of high-energy ball milling, La-content, and phase formation on the thermal diffusivity were also studied for La-doped ThO{sub 2} pellets by laser flash measurement. Increasing La-content and high energy ball milling time decreases thermal diffusivity; while the sintering peak temperature and holding time beyond 1600 °C dramatically altered the temperature dependence of the thermal diffusivity beyond 600 °C. - Highlights: • Lanthanum incorporation into ThO{sub 2} by high energy ball milling and rapid consolidation by spark plasma sintering. • Elucidation of phase behavior of the La-doped ThO{sub 2} and the contributions of La incorporation and SPS sintering conditions. • Investigation of the effects of La incorporation and high energy ball milling on the thermal behavior of La-doped ThO{sub 2}.

  8. Unpredictable Property of a Kicked Billiard Ball

    International Nuclear Information System (INIS)

    Shen Ying; Dai Jun; Jiang Yumei; He Yue; He Daren

    2006-01-01

    A simultaneous change in the systemic property of a kicked billiard ball is observed from an entirely smooth and conservative state to a piecewise smooth and quasi-dissipative state when a single controlling parameter has been adjusted. The transition induces a sudden change of a typical conservative stochastic web into a transient web. The iterations on the transient web eventually escape to some elliptic islands. In the meantime, a fat fractal forbidden web, which appears also at the threshold, grows up and cuts away increasingly more parts from the original conservative stochastic web. We numerically show that the initial conditions that generated different attractors are mixed in a random manner and the pattern remains unchanged even when smaller and smaller scales are used for examination, indicating a riddle-like basin structure that practically rules out the possibility of predicting the attractors from a given initial condition

  9. Poincare ball embeddings of the optical geometry

    International Nuclear Information System (INIS)

    Abramowicz, M A; Bengtsson, I; Karas, V; Rosquist, K

    2002-01-01

    It is shown that the optical geometry of the Reissner-Nordstroem exterior metric can be embedded in a hyperbolic space all the way down to its outer horizon. The adopted embedding procedure removes a breakdown of flat-space embeddings which occurs outside the horizon, at and below the Buchdahl-Bondi limit (R/M=9/4 in the Schwarzschild case). In particular, the horizon can be captured in the optical geometry embedding diagram. Moreover, by using the compact Poincare ball representation of the hyperbolic space, the embedding diagram can cover the whole extent of radius from spatial infinity down to the horizon. Attention is drawn to the advantages of such embeddings in an appropriately curved space: this approach gives compact embeddings and it clearly distinguishes the case of an extremal black hole from a non-extremal one in terms of the topology of the embedded horizon

  10. Grinding arrangement for ball nose milling cutters

    Science.gov (United States)

    Burch, C. F. (Inventor)

    1974-01-01

    A grinding arrangement for spiral fluted ball nose end mills and like tools includes a tool holder for positioning the tool relative to a grinding wheel. The tool is mounted in a spindle within the tool holder for rotation about its centerline and the tool holder is pivotably mounted for angular movement about an axis which intersects that centerline. A follower arm of a cam follower secured to the spindle cooperates with a specially shaped cam to provide rotation of the tool during the angular movement of the tool holder during the grinding cycle, by an amount determined by the cam profile. In this way the surface of the cutting edge in contact with the grinding wheel is maintained at the same height on the grinding wheel throughout the angular movement of the tool holder during the grinding cycle.

  11. Recent results from the Crystal Ball

    International Nuclear Information System (INIS)

    Porter, F.C.

    1981-09-01

    During the past year, the Crystal Ball experiment has continued the investigation of e + e - interactions at SPEAR. In the course of the year, we have slightly more than doubled the available datasets at the J/psi (to 2.2 x 10 6 produced J/psi) and the psi' (to 1.8 x 10 6 produced psi') resonances, and have increased the data in the 5.2 to 7.4 GeV center-of-mass (E/sub c.m./) region. The present discussion is limited to recent results obtained with the J/psi and psi' datasets, primarily dealing with transitions among the charmonium bound states

  12. The effects of cognitive anxiety on the biomechanical characteristics of the golf swing

    Directory of Open Access Journals (Sweden)

    MBA De Ste Croix

    2008-03-01

    Full Text Available The aim of this study was to examine the effect of cognitive anxiety (CA on the biomechanical characteristics of the golf swing. Written informed consent was obtained from 9 subjects, with a range of golf experience (handicap range 4-23. Each subject was filmed under a low anxiety condition (during practice, and a high anxiety condition (during competition and completed a revised version of the Competitive State Anxiety Inventory-2 (CSAI-2. Human movement analysis (Hu-m-an software package was used to identify the clubhead speeds during the backswing, downswing, and impact time, along with the completion times for each phase. The absolute angle of the club to the vertical, and the relative angle of the forearm, wrist, and club hinge, at the completion of the backswing stage were also examined. CA intensity scores were significantly lower during practice than competition (p<0.05. CA interpretation scores indicate that anxiety symptoms during practice were significantly more facilitative to performance (p<0.05. The time taken to complete the downswing phase was significantly lower during competition (p<0.05. The combined backswing and downswing times were significantly lower during the competition trial (p<0.05. There were no significant differences between the practice and competition trials on any of the remaining swing variables measured.

  13. Early Improper Motion Detection in Golf Swings Using Wearable Motion Sensors: The First Approach

    Science.gov (United States)

    Stančin, Sara; Tomažič, Sašo

    2013-01-01

    This paper presents an analysis of a golf swing to detect improper motion in the early phase of the swing. Led by the desire to achieve a consistent shot outcome, a particular golfer would (in multiple trials) prefer to perform completely identical golf swings. In reality, some deviations from the desired motion are always present due to the comprehensive nature of the swing motion. Swing motion deviations that are not detrimental to performance are acceptable. This analysis is conducted using a golfer's leading arm kinematic data, which are obtained from a golfer wearing a motion sensor that is comprised of gyroscopes and accelerometers. Applying the principal component analysis (PCA) to the reference observations of properly performed swings, the PCA components of acceptable swing motion deviations are established. Using these components, the motion deviations in the observations of other swings are examined. Any unacceptable deviations that are detected indicate an improper swing motion. Arbitrarily long observations of an individual player's swing sequences can be included in the analysis. The results obtained for the considered example show an improper swing motion in early phase of the swing, i.e., the first part of the backswing. An early detection method for improper swing motions that is conducted on an individual basis provides assistance for performance improvement. PMID:23752563

  14. Looking to Learn: The Effects of Visual Guidance on Observational Learning of the Golf Swing.

    Science.gov (United States)

    D'Innocenzo, Giorgia; Gonzalez, Claudia C; Williams, A Mark; Bishop, Daniel T

    2016-01-01

    Skilled performers exhibit more efficient gaze patterns than less-skilled counterparts do and they look more frequently at task-relevant regions than at superfluous ones. We examine whether we may guide novices' gaze towards relevant regions during action observation in order to facilitate their learning of a complex motor skill. In a Pre-test-Post-test examination of changes in their execution of the full golf swing, 21 novices viewed one of three videos at intervention: i) a skilled golfer performing 10 swings (Free Viewing, FV); ii) the same video with transient colour cues superimposed to highlight key features of the setup (Visual Guidance; VG); iii) or a History of Golf video (Control). Participants in the visual guidance group spent significantly more time looking at cued areas than did the other two groups, a phenomenon that persisted after the cues had been removed. Moreover, the visual guidance group improved their swing execution at Post-test and on a Retention test one week later. Our results suggest that visual guidance to cued areas during observational learning of complex motor skills may accelerate acquisition of the skill.

  15. Local Navon letter processing affects skilled behavior: a golf-putting experiment.

    Science.gov (United States)

    Lewis, Michael B; Dawkins, Gemma

    2015-04-01

    Expert or skilled behaviors (for example, face recognition or sporting performance) are typically performed automatically and with little conscious awareness. Previous studies, in various domains of performance, have shown that activities immediately prior to a task demanding a learned skill can affect performance. In sport, describing the to-be-performed action is detrimental, whereas in face recognition, describing a face or reading local Navon letters is detrimental. Two golf-putting experiments are presented that compare the effects that these three tasks have on experienced and novice golfers. Experiment 1 found a Navon effect on golf performance for experienced players. Experiment 2 found, for experienced players only, that performance was impaired following the three tasks described above, when compared with reading or global Navon tasks. It is suggested that the three tasks affect skilled performance by provoking a shift from automatic behavior to a more analytic style. By demonstrating similarities between effects in face recognition and sporting behavior, it is hoped to better understand concepts in both fields.

  16. Fertilizer source effects on phosphate and nitrate leaching through simulated golf greens

    International Nuclear Information System (INIS)

    Shuman, L.M.

    2003-01-01

    In general, more P than N leached from both field and greenhouse lysimeters. - Phosphorus and nitrogen leached from high-porosity golf greens can adversely affect surface water and groundwater quality. Greenhouse and field lysimeter experiments were carried out to determine the effects of eight fertilizer sources on P and N leaching from simulated golf greens. Phosphorus appeared in the leachate later than nitrate-N, and the highest concentrations were for the soluble 20-20-20 and the 16-25-12 starter fertilizers. The other six sources resulted in lower P concentrations. The soluble 20-20-20 and the 16-25-12 sources each resulted in 43% of the added P eluting in the leachate, whereas the others varied from 15 to 25%. For nitrate-N the lowest cumulative mass was for the controlled-release 13-13-13 and sulfur-coated urea. A higher percentage of applied P than applied N leached from both field and greenhouse lysimeters. However, the amounts of P leached for the field lysimeters were lower than for the greenhouse columns

  17. Development of a golf-specific load monitoring tool: Content validity and feasibility.

    Science.gov (United States)

    Williams, Scott B; Gastin, Paul B; Saw, Anna E; Robertson, Sam

    2018-05-01

    Athletes often record details of their training and competitions, supported by information such as environmental conditions, travel, as well as how they felt. However, it is not known how prevalent these practices are in golfers, or how valuable this process is perceived. The purpose of this study was to develop a golf-specific load monitoring tool (GLMT), and establish the content validity and feasibility of this tool amongst high-level golfers. In the first phase of development, 21 experts were surveyed to determine the suitability of items for inclusion in the GLMT. Of the 36 items, 21 received >78% agreement, a requirement to establish content validity and for inclusion in the GLMT. Total duration was the preferred metric for golf-specific activities, whilst rating of perceived exertion (RPE) was preferred for measuring physical training. In the second phase, feasibility of the tool was assessed by surveying 13 high-level male golfers following 28-days of daily GLMT use. All items included in the GLMT were deemed feasible to record, with all players participating in the feasibility study providing high to very high ratings. Golfers responded that they would consider using a load monitoring tool of this nature long term, provided it can be completed in less than five minutes per day.

  18. Photospheric activity of the Sun with VIRGO and GOLF. Comparison with standard activity proxies

    Science.gov (United States)

    Salabert, D.; García, R. A.; Jiménez, A.; Bertello, L.; Corsaro, E.; Pallé, P. L.

    2017-12-01

    We study the variability of solar activity using new photospheric proxies originally developed for the analysis of stellar magnetism with the CoRoT and Kepler photometric observations. These proxies were obtained by tracking the temporal modulations in the observations associated with the spots and magnetic features as the Sun rotates. We analyzed 21 yr of observations, spanning solar cycles 23 and 24, collected by the space-based photometric VIRGO and radial velocity GOLF instruments on board the SoHO satellite. We then calculated the photospheric activity proxy Sph is for each of the three VIRGO photometers and the associated Svel proxy from the radial velocity GOLF observations. Comparisons with several standard solar activity proxies sensitive to different layers of the Sun demonstrate that these new activity proxies, Sph and Svel, provide a new manner to monitor solar activity. We show that both the long- and short-term magnetic variabilities respectively associated with the 11-yr cycle and the quasi-biennial oscillation are well monitored, and that the magnetic field interaction between the subsurface, photosphere, and chromosphere of the Sun was modified between Cycle 24 and Cycle 23. Furthermore, the photometric proxies show a wavelength dependence of the response function of the solar photosphere among the three channels of the VIRGO photometers, providing inputs for the study of the stellar magnetism of Sun-like stars.

  19. The crunch factor's role in golf-related low back pain.

    Science.gov (United States)

    Cole, Michael H; Grimshaw, Paul N

    2014-05-01

    The golf swing exposes the spine to complex torsional, compressive, and shearing loads that increase a player's risk of injury. The crunch factor (CF) has been described as a measure to evaluate the risk of low back injuries in golfers and is based on the notion that lateral flexion and axial trunk rotation jointly contribute to spinal degeneration. However, few studies have evaluated the appropriateness of this measure in golfers with low back pain (LBP). To objectively examine the usefulness of the CF as a measure for assessing the risk of low back injury in golfers. Field-based research using a cross-sectional design. This research used three-dimensional motion analysis to assess the golf swings of 12 golfers with LBP and 15 asymptomatic controls. Three-dimensional kinematics were derived using Vicon Motus, and the CF was calculated as the instantaneous product of axial trunk rotation velocity and lateral trunk flexion angle. Maximum CFs and their timings were not significantly different between the symptomatic and asymptomatic groups. Furthermore, for those golfers who produced higher CFs (irrespective of the group), the increased magnitude could not be attributed to an increased axial angular trunk velocity or lateral flexion angle, but rather to a concomitant increase in both of these variables. The findings suggested that although the fundamental concepts that underpin the CF seem sensible, this measure does not appear to be sensitive enough to distinguish golfers with LBP from the asymptomatic players. Copyright © 2014 Elsevier Inc. All rights reserved.

  20. Customer Satisfaction Among the Members of the Summit Point Golf and Country Club

    Directory of Open Access Journals (Sweden)

    VERONICA JOY V. BENCITO

    2014-04-01

    Full Text Available This study focused on the customer satisfaction among the members of the Summit Point Golf and Country Club which served as the basis for continuous improvement. It determined the level of customer satisfaction on the services offered by the Summit Point employees in terms of food and beverages, customer service and facilities. Lastly, it also tested the significant differences on the level of customer satisfactions when grouped according to their membership variables of the club. The descriptive type of research was used to assess the operation of the club. Data gathered were analyzed using the weighted mean and ANOVA method. The members of the Summit Point Golf and Country Club are generally satisfied in terms of facilities and amenities, food and beverages and customer service. The hypothesis has no significant difference between the membership profile and level of customer satisfaction in terms of facilities and amenities and customer service is rejected. This means that their responses differ as to their reasons of joining the club, their obtained degree and the frequency of playing in the club.

  1. The relevance of coordination at the golf swing performance of junior players Importancia de la coordinación en el rendimiento del swing de golf en jóvenes promesas

    Directory of Open Access Journals (Sweden)

    D. Juarez

    2010-09-01

    Full Text Available

    The golf swing is a skill which could be classified as a high velocity hitting where the main goal is that the head of the golf club reaches its maximum velocity at impact time. The aim of this study was to find the movement pattern of the golf swing in order to apply this pattern to improve their performance. Twelve golf swings executed by four young players were biomechanically analyzed. Automatic capture with Vicon Oxford Metrics © was used. The analysis of the maximum angular velocity sequence during the downswing showed, that depending on the gender, they described different timing. The angular velocity sequences had the same order, being first the hip turn, secondly the shoulder turn y finally the golf club head acceleration. It was found discriminant function for each gender group which could predict whether the golf swing was “good” or “bad” considering the club head speed as performance criteria. This separation at the timing of the key events could be the reason why that explains men reached more velocity at the head club near impact time than women.
    Key Words: Biomechanics, hitting, swing, golf, pattern, performance.

     

    El swing de golf es una destreza que podríamos catalogar de golpeo de velocidad donde el objetivo es que la cara del palo alcance la máxima velocidad en el momento del impacto. El objetivo de este estudio fue hallar el patrón de movimiento en el swing de golf y aplicar este patrón para la mejora del rendimiento. Se han analizado biomecánicamente doce golpeos de cuatro jugadores promesas, mediante el sistema fotogrametría 3D Vicon Oxford Metrics © de captura automática. El análisis de la secuencia de velocidades angulares máximas en el downswing muestra cómo siguen un timing diferente en función del género. Las secuencias

  2. The relationships between impact location and post-impact ball speed, bat torsion, and ball direction in cricket batting.

    Science.gov (United States)

    Peploe, C; McErlain-Naylor, S A; Harland, A R; King, M A

    2018-06-01

    Three-dimensional kinematic data of bat and ball were recorded for 239 individual shots performed by twenty batsmen ranging from club to international standard. The impact location of the ball on the bat face was determined and assessed against the resultant instantaneous post-impact ball speed and measures of post-impact bat torsion and ball direction. Significant negative linear relationships were found between post-impact ball speed and the absolute distance of impact from the midline medio-laterally and sweetspot longitudinally. Significant cubic relationships were found between the distance of impact from the midline of the bat medio-laterally and both a measure of bat torsion and the post-impact ball direction. A "sweet region" on the bat face was identified whereby impacts within 2 cm of the sweetspot in the medio-lateral direction, and 4.5 cm in the longitudinal direction, caused reductions in ball speed of less than 6% from the optimal value, and deviations in ball direction of less than 10° from the intended target. This study provides a greater understanding of the margin for error afforded to batsmen, allowing researchers to assess shot success in more detail, and highlights the importance of players generating consistently central impact locations when hitting for optimal performance.

  3. Análisis de la accesibilidad en los campos de golf de la Región de Murcia

    Directory of Open Access Journals (Sweden)

    P. Zarco-Pérez

    2012-01-01

    Full Text Available Otorgar el correcto nivel de accesibilidad en los campos de golf es una premisa fundamental si se quiere fomentar y facilitar el acceso a la práctica del golf por personas con discapacidad. El presente estudio trata de analizar la accesibilidad en los campos de golf de la Región de Murcia. Para ello se recurre a un estudio de carácter cuantitativo utilizando una hoja de observación creada a partir de los criterios de accesibilidad encontrados en la legislación estatal y regional vigente, en la que se evalúa la accesibilidad de todos los campos de golf de 18 hoyos de la Comunidad Autónoma de Murcia. Los resultados indican que no se cumple la normativa vigente en torno a la accesibilidad ya que el cumplimiento de los ítems se sitúa por debajo de la mitad (40,88%. El área de accesos presenta el mejor resultado, con un 50,54% de ítems cumplidos de media, mientras que los vestuarios presentan los peores resultados, con un 34,94%. En todas las áreas se observa cómo la señalización y mobiliario presentan los porcentajes más bajos. Sería necesario tomar medidas para superar los criterios de accesibilidad requeridos para estos espacios.

  4. Evaluating poverty grass (Danthonia spicata L.) for use in tees, fairways, or rough areas in golf courses in the midwest

    Science.gov (United States)

    Nadia E. Navarrete-Tindall; Brad Fresenburg; J.W. Van Sambeek

    2007-01-01

    Poverty grass (Danthonia spicata L.), a native, cool-season perennial bunchgrass with wide distribution in the United States, is being evaluated for its suitability for use on golf courses. The goal is to identify practices to improve seed germination and successfully establish field plots as monocultures or with other native species to mimic natural...

  5. The identification of benefit needs of golf players in the U.S.: Implicationsand strategy considerations for sport management professionals

    Directory of Open Access Journals (Sweden)

    CHUNG-MI LEE

    2006-01-01

    Full Text Available The golf industry has expanded over the past 50 years throughout the world, particularly in America. The number of golfers in the United States has increased seven-fold since 1950, as the game was transformed from an expensive diversion of the rich to a mass-market pastime. A number of recent studies have shown that demographic variables such as age, gender, occupation, income, and race are –in general– poor predictors of golfers’ consumer behaviour and, consequently, less than optimum bases for segmentation strategies. Because of those problems associated with demographic segmentation, benefit segmentation has become a favourite tool of marketers; to satisfy target consumers’ needs, benefit needs and product attributes are the most popular variables for segmenting the target market. The main strength of benefit segmentation lies in the causal relationship to perceived future behaviour. The purpose of this study was to identify the benefit needs of golfers who frequent public golf courses. Implications for public golf course owners or managers are then discussed with strategy considerations about golf marketing for a variety of benefit segments.

  6. Biochar-organic amendment mixtures added to simulated golf greens under reduced chemical fertilization increase creeping bentgrass growth

    Science.gov (United States)

    Simulated golf greens were used to test the growth of creeping bentgrass (Agrostis stolonifera L. "007") receiving suboptimal chemical fertilization in sand based substrates amended with 15% peat (control), a commercial biochar, a commercial biochar-compost (CarbonizPN), or seven formulated biochar...

  7. An electromyographic study of the effect of hand grip sizes on forearm muscle activity and golf performance.

    Science.gov (United States)

    Sorbie, Graeme G; Hunter, Henry H; Grace, Fergal M; Gu, Yaodong; Baker, Julien S; Ugbolue, Ukadike Chris

    2016-01-01

    The study describes the differences in surface electromyography (EMG) activity of two forearm muscles in the lead and trail arm at specific phases of the golf swing using a 7-iron with three different grip sizes among amateur and professional golfers. Fifteen right-handed male golfers performed five golf swings using golf clubs with three different grip sizes. Surface EMG was used to measure muscle activity of the extensor carpi radialis brevis (ECRB) and flexor digitorum superficialis (FDS) on both forearms. There were no significant differences in forearm muscle activity when using the three golf grips within the group of 15 golfers (p > 0.05). When using the undersize grip, club head speed significantly increased (p = 0.044). During the backswing and downswing phases, amateurs produced significantly greater forearm muscle activity with all three grip sizes (p < 0.05). In conclusion, forearm muscle activity is not affected by grip sizes. However, club head speed increases when using undersize grips.

  8. Solid propellant impact tests

    International Nuclear Information System (INIS)

    Snow, E.C.

    1976-03-01

    Future space missions, as in the past, call for the continued use of radioisotopes as heat sources for thermoelectric power generators. In an effort to minimize the risk of radioactive contamination of the environment, a complete safety analysis of each such system is necessary. As a part of these analyses, the effects on such a system of a solid propellant fire environment resulting from a catastrophic launch pad abort must be considered. Several impact tests were conducted in which either a simulant MHW-FSA or a steel ball was dropped on the cold, unignited or the hot, burning surface of a block of UTP-3001 solid propellant. The rebound velocities were measured for both surface conditions of the propellant. The resulting coefficient of restitution, determined as the ratio of the components of the impact and rebound velocities perpendicular to the impact surface of the propellant, were not very dependent on whether the surface was cold or hot at the time of impact

  9. Kinematic evaluation of movement smoothness in golf: relationship between the normalized jerk cost of body joints and the clubhead.

    Science.gov (United States)

    Choi, Ahnryul; Joo, Su-Bin; Oh, Euichaul; Mun, Joung Hwan

    2014-02-26

    When the human body is introduced to a new motion or movement, it learns the placement of different body parts, sequential muscle control, and coordination between muscles to achieve necessary positions, and it hones this new skill over time and repetition. Previous studies have demonstrated definite differences in the smoothness of body movements with different levels of training, i.e., amateurs compared with professionals. Therefore, we tested the hypothesis that skilled golfers swing a driver with a smoother motion than do unskilled golfers. In addition, the relationship between the smoothness of body joints and that of the clubhead was evaluated to provide further insight into the mechanism of smooth golf swing. Two subject groups (skilled and unskilled) participated in the experiment. The skilled group comprised 20 male professional golfers registered with the Korea Professional Golf Association, and the unskilled group comprised 19 amateur golfers who enjoy golf as a hobby. Six infrared cameras (VICON460 system) were used to record the 3D trajectories of markers attached to the clubhead and body segments, and the resulting data was evaluated with kinematic analysis. A physical quantity called jerk was calculated to investigate differences in smoothness during downswing between the two study groups. The hypothesis that skilled golfers swing a driver with a smoother motion than do unskilled golfers was supported. The normalized jerk of the clubhead of skilled golfers was lower than that of unskilled golfers in the anterior/posterior, medial/lateral, and proximal/distal directions. Most human joints, especially in the lower body, had statistically significant lower normalized jerk values in the skilled group. In addition, the normalized jerk of the skilled group's lower body joints had a distinct positive correlation with the normalized jerk of the clubhead with r = 0.657 (p golf swings and, eventually, to improve golf performance.

  10. Tracking of ball and players in beach volleyball videos.

    Directory of Open Access Journals (Sweden)

    Gabriel Gomez

    Full Text Available This paper presents methods for the determination of players' positions and contact time points by tracking the players and the ball in beach volleyball videos. Two player tracking methods are compared, a classical particle filter and a rigid grid integral histogram tracker. Due to mutual occlusion of the players and the camera perspective, results are best for the front players, with 74,6% and 82,6% of correctly tracked frames for the particle method and the integral histogram method, respectively. Results suggest an improved robustness against player confusion between different particle sets when tracking with a rigid grid approach. Faster processing and less player confusions make this method superior to the classical particle filter. Two different ball tracking methods are used that detect ball candidates from movement difference images using a background subtraction algorithm. Ball trajectories are estimated and interpolated from parabolic flight equations. The tracking accuracy of the ball is 54,2% for the trajectory growth method and 42,1% for the Hough line detection method. Tracking results of over 90% from the literature could not be confirmed. Ball contact frames were estimated from parabolic trajectory intersection, resulting in 48,9% of correctly estimated ball contact points.

  11. Tracking of Ball and Players in Beach Volleyball Videos

    Science.gov (United States)

    Gomez, Gabriel; Herrera López, Patricia; Link, Daniel; Eskofier, Bjoern

    2014-01-01

    This paper presents methods for the determination of players' positions and contact time points by tracking the players and the ball in beach volleyball videos. Two player tracking methods are compared, a classical particle filter and a rigid grid integral histogram tracker. Due to mutual occlusion of the players and the camera perspective, results are best for the front players, with 74,6% and 82,6% of correctly tracked frames for the particle method and the integral histogram method, respectively. Results suggest an improved robustness against player confusion between different particle sets when tracking with a rigid grid approach. Faster processing and less player confusions make this method superior to the classical particle filter. Two different ball tracking methods are used that detect ball candidates from movement difference images using a background subtraction algorithm. Ball trajectories are estimated and interpolated from parabolic flight equations. The tracking accuracy of the ball is 54,2% for the trajectory growth method and 42,1% for the Hough line detection method. Tracking results of over 90% from the literature could not be confirmed. Ball contact frames were estimated from parabolic trajectory intersection, resulting in 48,9% of correctly estimated ball contact points. PMID:25426936

  12. Water Bouncing Balls: how material stiffness affects water entry

    Science.gov (United States)

    Truscott, Tadd

    2014-03-01

    It is well known that one can skip a stone across the water surface, but less well known that a ball can also be skipped on water. Even though 17th century ship gunners were aware that cannonballs could be skipped on the water surface, they did not know that using elastic spheres rather than rigid ones could greatly improve skipping performance (yet would have made for more peaceful volleys). The water bouncing ball (Waboba®) is an elastic ball used in a game of aquatic keep away in which players pass the ball by skipping it along the water surface. The ball skips easily along the surface creating a sense that breaking the world record for number of skips could easily be achieved (51 rock skips Russell Byers 2007). We investigate the physics of skipping elastic balls to elucidate the mechanisms by which they bounce off of the water. High-speed video reveals that, upon impact with the water, the balls create a cavity and deform significantly due to the extreme elasticity; the flattened spheres resemble skipping stones. With an increased wetted surface area, a large hydrodynamic lift force is generated causing the ball to launch back into the air. Unlike stone skipping, the elasticity of the ball plays an important roll in determining the success of the skip. Through experimentation, we demonstrate that the deformation timescale during impact must be longer than the collision time in order to achieve a successful skip. Further, several material deformation modes can be excited upon free surface impact. The effect of impact velocity and angle on the two governing timescales and material wave modes are also experimentally investigated. Scaling for the deformation and collision times are derived and used to establish criteria for skipping in terms of relevant physical parameters.

  13. New techniques to control salinity-wastewater reuse interactions in golf courses of the Mediterranean regions

    Science.gov (United States)

    Beltrao, J.; Costa, M.; Rosado, V.; Gamito, P.; Santos, R.; Khaydarova, V.

    2003-04-01

    Due to the lack water around the Mediterranean regions, potable water luxurious uses - as in golf courses - are increasingly contested. In order to solve this problem, non conventional water resources (effluent, gray, recycled, reclaimed, brackish), like treated wastewater, for irrigation gained increasing role in the planning and development of additional water supplies in golf courses. In most cases, the intense use of effluent for irrigation attracted public awareness in respect of contaminating pathogens and heavy metals. The contaminating effect of salinity in soil and underground water is very often neglected. The objective of this work is to present the conventional techniques to control salinity of treated wastewater and to present some results on new clean techniques to solve this problem, in the framework of the INCO-COPERNICUS project (no. IC-15CT98-0105) "Adaptation of Efficient Water Use Criteria in Marginal Regions of Europe and Middle Asia with Scarce Sources Subject to Environmental Control, Climate Change and Socio-Economic Development" and of the INCO-DC project (no. IC18-CT98-0266) "Control of Salination and Combating Desertification Effects in the Mediterranean Region. Phase II". Saline water is the most common irrigation water in arid climates. Moreover, for each region treated wastewater is always more saline than tap water, and therefore, when treated wastewater is reused in golf courses, more salinity problems occur. Conventional techniques to combat the salination process in golf courses can be characterized by four generations: 1) Problem of root zone salination by soil leaching - two options can occur - when there is an impermeable layer, salts will be concentrated above this layer; on the other hand, when there is no impermeable layer, aquifers contamination can be observed; 2) Use of subsurface trickle irrigation - economy of water, and therefore less additional salts; however the problem of groundwater contamination due to natural rain

  14. Synthesis of the Mg2Ni alloy prepared by mechanical alloying using a high energy ball mill

    International Nuclear Information System (INIS)

    Iturbe G, J. L.; Lopez M, B. E.; Garcia N, M. R.

    2010-01-01

    Mg 2 Ni was synthesized by a solid state reaction from the constituent elemental powder mixtures via mechanical alloying. The mixture was ball milled for 10 h at room temperature in an argon atmosphere. The high energy ball mill used here was fabricated at ININ. A hardened steel vial and three steel balls of 12.7 mm in diameter were used for milling. The ball to powder weight ratio was 10:1. A small amount of powder was removed at regular intervals to monitor the structural changes. All the steps were performed in a little lucite glove box under argon gas, this glove box was also constructed in our Institute. The structural evolution during milling was characterized by X-ray diffraction and scanning electron microscopy techniques. The hydrogen reaction was carried out in a micro-reactor under controlled conditions of pressure and temperature. The hydrogen storage properties of mechanically milled powders were evaluated by using a thermogravimetric analysis system. Although homogeneous refining and alloying take place efficiently by repeated forging, the process time can be reduced to one fiftieth of the time necessary for conventional mechanical milling and attrition. (Author)

  15. Synthesis of the Mg{sub 2}Ni alloy prepared by mechanical alloying using a high energy ball mill

    Energy Technology Data Exchange (ETDEWEB)

    Iturbe G, J. L.; Lopez M, B. E. [ININ, Departamento de Quimica, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico); Garcia N, M. R., E-mail: joseluis.iturbe@inin.gob.m [UNAM, Facultad de Estudios Superiores Zaragoza, Batalla 5 de Mayo s/n, Esq. Fuerte de Loreto, Col. Ejercito de Oriente, 09230 Mexico D. F. (Mexico)

    2010-07-01

    Mg{sub 2}Ni was synthesized by a solid state reaction from the constituent elemental powder mixtures via mechanical alloying. The mixture was ball milled for 10 h at room temperature in an argon atmosphere. The high energy ball mill used here was fabricated at ININ. A hardened steel vial and three steel balls of 12.7 mm in diameter were used for milling. The ball to powder weight ratio was 10:1. A small amount of powder was removed at regular intervals to monitor the structural changes. All the steps were performed in a little lucite glove box under argon gas, this glove box was also constructed in our Institute. The structural evolution during milling was characterized by X-ray diffraction and scanning electron microscopy techniques. The hydrogen reaction was carried out in a micro-reactor under controlled conditions of pressure and temperature. The hydrogen storage properties of mechanically milled powders were evaluated by using a thermogravimetric analysis system. Although homogeneous refining and alloying take place efficiently by repeated forging, the process time can be reduced to one fiftieth of the time necessary for conventional mechanical milling and attrition. (Author)

  16. Dry grinding of talc in a stirred ball mill

    Directory of Open Access Journals (Sweden)

    Cayirli Serkan

    2016-01-01

    Full Text Available The aim of this work was to investigate micro fine size dry grindability of talc in a stirred ball mill. The effects of various parameters such as grinding time, stirrer speed, powder filling ratio and ball filling ratio were investigated. Alumina balls were used as grinding media. Experiments were carried out using the 24 full factorial design. The main and interaction effects were evaluated using the Yates method. Test results were evaluated on the basis of product size and surface area.

  17. Gas-discharge particle detector with ball-tipped anodes

    International Nuclear Information System (INIS)

    Travkin, V.I.; Khazins, D.M.

    1987-01-01

    A new gas-discharge particle detector, whose anode is a set of balls 2mm in diameter is investigated. The chamber is blowing down by the argon-methane-methylal gas mixture with the ratio 3:1:1. The detector operates in the self-quenching streamer mode, has high efficiency and a wide counting characteristic plateau. The maximum counting rate of particles at one ball is ∼ 2.5x10 4 s -1 . The ball-tipped anodes allow making reliable complex-shaped detectors. Two-coordinate detection of multiparticle events can be naturally organized in detectors like that

  18. Numerical study of Q-ball formation in gravity mediation

    International Nuclear Information System (INIS)

    Hiramatsu, Takashi; Kawasaki, Masahiro; Takahashi, Fuminobu

    2010-01-01

    We study Q-ball formation in the expanding universe on 1D, 2D and 3D lattice simulations. We obtain detailed Q-ball charge distributions, and find that the distribution is peaked at Q 3D peak ≅ 1.9 × 10 −2 (|Φ in |/m) 2 , which is greater than the existing result by about 60%. Based on the numerical simulations, we discuss how the Q-ball formation proceeds. Also we make a comment on possible deviation of the charge distributions from what was conjectured in the past

  19. The development of cobalt-base alloy ball bearing

    International Nuclear Information System (INIS)

    Yu Xinshui; Chen Jianting; Wang Zaishu; Wang Ximei; Huang Chongming.

    1986-01-01

    The main technologies and experiences in developing a Cobalt-base alloy ball bearing are described. In the hardfacing of bearing races, a lower-hardness alloy of type St-6 is used rather than an alloy with hardness similar to that of the ball and finally the hardness of race is increased to match that of the ball by heat treatment. This improvement has certain advantages. The experience of whole developing technology indicates that strict control of the technology in the bearing-race hardfacing is the key problem in the quality assurance of bearings

  20. Ranking prediction model using the competition record of Ladies Professional Golf Association players.

    Science.gov (United States)

    Chae, Jin Seok; Park, Jin; So, Wi-Young

    2017-07-28

    The purpose of this study was to suggest a ranking prediction model using the competition record of the Ladies Professional Golf Association (LPGA) players. The top 100 players on the tour money list from the 2013-2016 US Open were analyzed in this model. Stepwise regression analysis was conducted to examine the effect of performance and independent variables (i.e., driving accuracy, green in regulation, putts per round, driving distance, percentage of sand saves, par-3 average, par-4 average, par-5 average, birdies average, and eagle average) on dependent variables (i.e., scoring average, official money, top-10 finishes, winning percentage, and 60-strokes average). The following prediction model was suggested:Y (Scoring average) = 55.871 - 0.947 (Birdies average) + 4.576 (Par-4 average) - 0.028 (Green in regulation) - 0.012 (Percentage of sand saves) + 2.088 (Par-3 average) - 0.026 (Driving accuracy) - 0.017 (Driving distance) + 0.085 (Putts per round)Y (Official money) = 6628736.723 + 528557.907 (Birdies average) - 1831800.821 (Par-4 average) + 11681.739 (Green in regulation) + 6476.344 (Percentage of sand saves) - 688115.074 (Par-3 average) + 7375.971 (Driving accuracy)Y (Top-10 finish%) = 204.462 + 12.562 (Birdies average) - 47.745 (Par-4 average) + 1.633 (Green in regulation) - 5.151 (Putts per round) + 0.132 (Percentage of sand saves)Y (Winning percentage) = 49.949 + 3.191 (Birdies average) - 15.023 (Par-4 average) + 0.043 (Percentage of sand saves)Y (60-strokes average) = 217.649 + 13.978 (Birdies average) - 44.855 (Par-4 average) - 22.433 (Par-3 average) + 0.16 (Green in regulation)Scoring of the above five prediction models and the prediction of golf ranking in the 2016 Women's Golf Olympic competition in Rio revealed a significant correlation between the predicted and real ranking (r = 0.689, p ranking prediction model using LPGA data may help coaches and players to identify which players are likely to participate in Olympic and World competitions, based

  1. The Development and Validation of a Golf Swing and Putt Skill Assessment for Children

    Directory of Open Access Journals (Sweden)

    Lisa M. Barnett, Louise L. Hardy, Ali S. Brian

    2015-03-01

    Full Text Available The aim was to describe development of a process-oriented instrument designed to assess the golf swing and putt stroke, and to assess the instrument’s discriminative validity in terms of age and reliability (intra-rater and re-test. A Delphi consultation (with golf industry professionals and researchers in movement skill assessment was used to develop an assessment for each skill based on existing skill assessment protocols. Each skill had six components to be marked as present/absent. Individual scores were based on the number of performance components successfully demonstrated over two trials for each skill (potential score range 0 to 24. Children (n = 43 aged 6-10 years (M = 7.8 years, SD = 1.3 were assessed in both skills live in the field by one rater at Time 1(T1. A subset of children (n = 28 had consent for assessments to be videoed. Six weeks later 19 children were reassessed, five days apart (T2, T3. An ANOVA assessed discriminative validity i.e. whether skill competence at T1 differed by age (6 years, 7/8 years and 9/10 years. Intraclass correlations (ICC assessed intra-rater reliability between the live and video assessment at T1 and test-retest reliability (between T2 and T3. Paired t-tests assessed any systematic differences between live and video assessments (T1 and between T2 and T3. Older children were more skilled (F (2, 40 = 11.18, p < 0.001. The live assessment reflected the video assessment (ICC = 0.79, 95% CI 0.59, 0.90 and scores did not differ between live and video assessments. Test retest reliability was acceptable (ICC = 0.60, 95% CI 0.23, 0.82, although the mean score was slightly higher at retest. This instrument could be used reliably by golf coaches and physical education teachers as part of systematic early player assessment and feedback.

  2. Diagnostic evaluation of rolling behavior in ball bearings by ultrasonic technique

    International Nuclear Information System (INIS)

    Wakabayashi, T

    2012-01-01

    Failures of machines having rotating parts are mostly caused by damage to bearings and there exist increasing demands for detecting damaged bearings at an early stage. However, conventional diagnostic methods, such as measuring temperature and observing vibration, have found difficulties in performing the early detection, so that more advanced diagnosis is necessary. This study therefore applies an ultrasonic technique as an advanced diagnostic method to bearing life tests. Ultrasonic wave pulses (UWP) emitted from a piezoelectric UWP generator can partially reflect from the interfaces of contact zones within the housing and the bearing with regard to the different acoustic impedance between a solid-to-solid contact and a contact dominated by some fluid layers. Hence, the intensity of the resultant UWP echoes can be determined by the real contact area formed at the interfaces. The experimental results of UWP echoes under the different operating conditions have demonstrated that the time intervals between peaks of UWP echoes varied in accordance with the movement of rolling balls and the lubricating phenomena in bearings. This behavior has further suggested the possibility of the early detection of abnormalities in ball bearings by using the variation in UWP echoes.

  3. Sources and components of ball lightning theory

    Science.gov (United States)

    Nikitin, A. I.; Bychkov, V. L.; Nikitina, T. F.; Velichko, A. M.; Abakumov, V. I.

    2018-03-01

    The article describes the cases when ball lightning (BL) exhibited an extremely high specific energy store (up to 1010 J/m3), a presence of uncompensated electric charge (up to 10‑3 C) and an ability to generate high frequency pulses (up to 10 MW). It is shown that the realization of a combination of these properties of BL is possible if to consider it as a heterogeneous system consisting of a unipolarly charged core and a dielectric shell. In the electric field of the core charge, arises a force owing to the polarization of the shell that opposes the Coulomb repulsion force of the charges. BL models constructed according to the indicated principle are described: the electrodynamic model and the chemical-thermal model, which treats BL as a hollow sphere filled with steam. The requirement to take into account the main three properties of BL makes it possible to reduce the number of models of this natural phenomenon. Detailed cases of observations of high-energy lightning are analyzed.

  4. Training simulator for teaching a technique to the long transmission of ball in basket-ball by a method by an arcuated hand from above with threaten

    Directory of Open Access Journals (Sweden)

    Charikova K.M.

    2012-03-01

    Full Text Available Technical devices which used in basket-ball are considered. The features of constructing of trainers and method of their application are selected in a training process. A trainer is offered for teaching a technique to the long transmission of ball in basket-ball. A trainer is a moving on a rope imitator of basket-ball ball. This construction allows to design initial position, замах for implementation of transmission and line of acceleration of ball in the final phase of motion. The method of the use of trainer is developed in an educational process.

  5. Validation of an Inertial Sensor System for Swing Analysis in Golf

    Directory of Open Access Journals (Sweden)

    Paul Lückemann

    2018-02-01

    Full Text Available Wearable inertial sensor systems are an upcoming tool for self-evaluation in sports, and can be used for swing analysis in golf. The aim of this work was to determine the validity and repeatability of an inertial sensor system attached to a player’s glove using a radar system as a reference. 20 subjects performed five full swings with each of three different clubs (wood, 7-iron, wedge. Clubhead speed was measured simultaneously by both sensor systems. Limits of Agreement were used to determine the accuracy and precision of the inertial sensor system. Results show that the inertial sensor system is quite accurate but with a lack of precision. Random error was quantified to approximately 17 km/h. The measurement error was dependent on the club type and was weakly negatively correlated to the magnitude of clubhead speed.

  6. Putting to a bigger hole: Golf performance relates to perceived size

    Science.gov (United States)

    Witt, Jessica K.; Linkenauger, Sally A.; Bakdash, Jonathan Z.; Proffitt, Dennis R.

    2011-01-01

    When engaged in a skilled behaviour such as occurs in sports, people's perceptions relate optical information to their performance. In current research we demonstrate the effects of performance on size perception in golfers. We found golfers who played better judged the hole to be bigger than golfers who did not play as well (Study 1). In follow-up laboratory experiments, participants putted on a golf mat from a location near or far from the hole then judged the size of the hole. Participants who putted from the near location perceived the hole to be bigger than participants who putted from the far location. Our results demonstrate that perception is influenced by the perceiver's current ability to act effectively in the environment. PMID:18567258

  7. Influencia de variables psicológicas en el rendimiento de jugadores amateurs de golf

    Directory of Open Access Journals (Sweden)

    Susana Irazusta

    2006-01-01

    Full Text Available El propósito de la presente investigación es analizar las variaciones del estado de ánimo intracompetición en los jugadores amateurs de golf, así como analizar la influencia que tiene el grado de confianza y otras variables motivacionales en el resultado de la competición. Se realizó la investigación con un total de 296 jugadores y se pasaron los cuestionarios a cada jugador en tres momentos, antes, durante y después de la competición.Una vez analizados los datos se constató que existen grandes fluctuaciones en el estado de ánimo de los jugadores y que el resultado esperado sufre modificaciones a lo largo de la competición.

  8. Positive psychology interventions in golf: Mindfulness versus positive self-talk

    Directory of Open Access Journals (Sweden)

    2015-09-01

    Results: There was a significant multivariate effect of Time on putting test scores, F(1, 21 = 13.9, p = .001, Ƞ2 = .399. Specifically, a mean increase of 1.4 out of 10 putts over the 4-week intervention period was found, but no univariate effect of Time on distance (cm from the hole for putts missed. There was no Group or Time by Group interaction effect for either putting test variable. Furthermore, groups did not differ at baseline or post-intervention on reported handicap, KIMS, technique adherence, or rounds of golf played. Conclusions: These preliminary findings fail to support previously reported findings that mindfulness or positive self-talk have short-term effects on putting accuracy. To maximise access, the current study used a self-guided intervention, which may have accounted for the lack of improvement that may occur with one-on-one coaching.

  9. Ball lightning as a route to fusion energy

    International Nuclear Information System (INIS)

    Roth, J.R.

    1989-01-01

    The reality of ball lightning is attested to by observations reported in surveys of large populations, which are the subject of several books. These observations indicate that its characteristics may be relevant to fusion energy applications. Ball lightning can have a diameter up to several meters, a lifetime of over 100 seconds, an energy content in excess of 10 megajoules, and an energy density and a kinetic pressure greater than that of a reacting DT plasma. This paper reviews some of the properties of ball lightning which commend it to the attention of the fusion community, and it discusses some potential advantages and applications of ball lightning fusion reactors. 11 refs., 6 figs., 1 tab

  10. An experiment on a ball-lightning model

    International Nuclear Information System (INIS)

    Ignatovich, F.V.; Ignatovich, V.K.

    2010-01-01

    We discuss total internal reflection (TIR) from an interface between glass and gainy gaseous media and propose an experiment for strong light amplification related to investigation of a ball-lightning model

  11. An aerodynamic analysis of recent FIFA world cup balls

    Science.gov (United States)

    Kiratidis, Adrian L.; Leinweber, Derek B.

    2018-05-01

    Drag and lift coefficients of recent FIFA world cup balls are examined. We fit a novel functional form to drag coefficient curves and in the absence of empirical data provide estimates of lift coefficient behaviour via a consideration of the physics of the boundary layer. Differences in both these coefficients for recent balls, which result from surface texture modification, can significantly alter trajectories. Numerical simulations are used to quantify the effect these changes have on the flight paths of various balls. Altitude and temperature variations at recent world cup events are also discussed. We conclude by quantifying the influence these variations have on the three most recent world cup balls, the Brazuca, the Jabulani and the Teamgeist. While our paper presents findings of interest to the professional sports scientist, it remains accessible to students at the undergraduate level.

  12. On the isoperimetric rigidity of extrinsic minimal balls

    DEFF Research Database (Denmark)

    Markvorsen, Steen; Palmer, V.

    2003-01-01

    We consider an m-dimensional minimal submanifold P and a metric R-sphere in the Euclidean space R-n. If the sphere has its center p on P, then it will cut out a well defined connected component of P which contains this center point. We call this connected component an extrinsic minimal R-ball of P....... The quotient of the volume of the extrinsic ball and the volume of its boundary is not larger than the corresponding quotient obtained in the space form standard situation, where the minimal submanifold is the totally geodesic linear subspace R-m. Here we show that if the minimal submanifold has dimension...... larger than 3, if P is not too curved along the boundary of an extrinsic minimal R-ball, and if the inequality alluded to above is an equality for the extrinsic minimal ball, then the minimal submanifold is totally geodesic....

  13. An overview of Ball Aerospace cryogen storage and delivery systems

    International Nuclear Information System (INIS)

    Marquardt, J; Keller, J; Mills, G; Schmidt, J

    2015-01-01

    Starting on the Gemini program in the 1960s, Beech Aircraft (now Ball Aerospace) has been designing and manufacturing dewars for a variety of cryogens including liquid hydrogen and oxygen. These dewars flew on the Apollo, Skylab and Space Shuttle spacecraft providing fuel cell reactants resulting in over 150 manned spaceflights. Since Space Shuttle, Ball has also built the liquid hydrogen fuel tanks for the Boeing Phantom Eye unmanned aerial vehicle. Returning back to its fuel cell days, Ball has designed, built and tested a volume-constrained liquid hydrogen and oxygen tank system for reactant delivery to fuel cells on unmanned undersea vehicles (UUVs). Herein past history of Ball technology is described. Testing has been completed on the UUV specific design, which will be described. (paper)

  14. Severe wear behaviour of alumina balls sliding against diamond ...

    Indian Academy of Sciences (India)

    study, alumina ball was chosen as the counter body material to show better performance of the ... Tribology is a relatively new science that considers ... The science is applied in ... for example, in hip prosthesis, instead of existing alumina.

  15. Changes in task self-efficacy and emotion across competitive performances in golf.

    Science.gov (United States)

    Boardley, Ian D; Jackson, Ben; Simmons, Alexander

    2015-08-01

    This research aimed to investigate (a) the effect of golfers' perceptions of coach motivation efficacy on golfers' precompetition task self-efficacy, (b) the effect of performance on pre-to-postround changes in self-efficacy, (c) the effect of pre-to-postround changes in self-efficacy on pre-to-postround changes in affect and emotion, and (d) whether any effects of performance on pre-to-postcompetition changes in affect and emotion were mediated by pre-to-postcompetition changes in self-efficacy. In Study 1, a scale measuring golf self-efficacy was developed and validated using data from 197 golfers. In Study 2, 200 golfers completed this measure alongside measures of coach motivation efficacy, and positive and negative affect before a golf competition; all measures (except coach motivation efficacy) were again completed following the competition. Structural equation modeling showed that coach motivation efficacy positively predicted precompetition self-efficacy, performance positively predicted pre-to-postcompetition changes in self-efficacy, which had positive and negative effects, respectively, on pre-to-postcompetition changes in positive and negative affect; mediation analyses demonstrated that pre-to-postcompetition changes in self-efficacy mediated effects of performance on pre-to-postcompetition changes in positive and negative affect. In Study 3, the Study-2 procedures were replicated with a separate sample of 212 golfers, except measures of excitement, concentration disruption, somatic anxiety, and worry replaced those for positive and negative affect. Structural analyses showed the findings from Study 2 were largely replicated when specific emotions were investigated in place of general indices of affect. This investigation makes novel contributions regarding the potential importance of perceptions of coach efficacy for golfers' own efficacy beliefs, and the role personal efficacy beliefs may play in facilitating the effects of performance on affective

  16. On the signatures of flare-induced global waves in the Sun: GOLF and VIRGO observations

    Science.gov (United States)

    Kumar, Brajesh; Mathur, Savita; García, Rafael A.; Jiménez, Antonio

    2017-11-01

    Recently, several efforts have been made to identify the seismic signatures of flares and magnetic activity in the Sun and Sun-like stars. In this work, we have analysed the disc-integrated velocity and intensity observations of the Sun obtained from the Global Oscillations at Low Frequencies (GOLF) and Variability of solar IRradiance and Gravity Oscillations/Sun photometers (VIRGO/SPM) instruments, respectively, on board the Solar and Heliospheric Observatory space mission covering several successive flare events, for the period from 2011 February 11 to 2011 February 17, of which 2011 February 11 remained a relatively quiet day and served as a `null test' for the investigation. Application of the spectral analysis to these disc-integrated Sun-as-a-star velocity and intensity signals indicates that there is enhanced power of the global modes of oscillations in the Sun during the flares, as compared to the quiet day. The GOLF instrument obtains velocity observations using the Na I D lines which are formed in the upper solar photosphere, while the intensity data used in our analysis are obtained by VIRGO/SPM instrument at 862 nm, which is formed within the solar photosphere. Despite the fact that the two instruments sample different layers of the solar atmosphere using two different parameters (velocity versus intensity), we have found that both these observations show the signatures of flare-induced global waves in the Sun. These results could suffice in identifying the asteroseismic signatures of stellar flares and magnetic activity in the Sun-like stars.

  17. Treatment of obstructive sleep apnea syndrome with nasal positive airway pressure improves golf performance.

    Science.gov (United States)

    Benton, Marc L; Friedman, Neil S

    2013-12-15

    Obstructive sleep apnea syndrome (OSAS) is associated with impairment of cognitive function, and improvement is often noted with treatment. Golf is a sport that requires a range of cognitive skills. We evaluated the impact of nasal positive airway pressure (PAP) therapy on the handicap index (HI) of golfers with OSAS. Golfers underwent a nocturnal polysomnogram (NPSG) to determine whether they had significant OSAS (respiratory disturbance index > 15). Twelve subjects with a positive NPSG were treated with PAP. HI, an Epworth Sleepiness Scale (ESS), and sleep questionnaire (SQ) were submitted upon study entry. After 20 rounds of golf on PAP treatment, the HI was recalculated, and the questionnaires were repeated. A matched control group composed of non-OSAS subjects was studied to assess the impact of the study construct on HI, ESS, and SQ. Statistical comparisons between pre- and post-PAP treatment were calculated. The control subjects demonstrated no significant change in HI, ESS, or SQ during this study, while the OSAS group demonstrated a significant drop in average HI (11.3%, p = 0.01), ESS, (p = 0.01), and SQ (p = 0.003). Among the more skilled golfers (defined as HI ≤ 12), the average HI dropped by an even greater degree (31.5%). Average utilization of PAP was 91.4% based on data card reporting. Treatment of OSAS with PAP enhanced performance in golfers with this condition. Treatment adherence was unusually high in this study. Non-medical performance improvement may be a strong motivator for selected subjects with OSAS to seek treatment and maximize adherence.

  18. The dialogue between data and model: passive stability and relaxation behavior in a ball bouncing task

    NARCIS (Netherlands)

    Dijkstra, T.M.H.; Katsumata, H.; Rugy, A. de; Sternad, D.

    2004-01-01

    We investigate the skill of rhythmically bouncing a ball on a racket with a focus on the mathematical modeling of the stability of performance. As a first step we derive the deterministic ball bouncing map as a Poincar´e section of a sinusoidally driven bouncing ball. Subsequently, we show the ball

  19. The head tracks and gaze predicts: how the world's best batters hit the ball

    NARCIS (Netherlands)

    Mann, D.L.; Spratford, W.; Abernethy, B.

    2013-01-01

    Hitters in fast ball-sports do not align their gaze with the ball throughout ball-flight; rather, they use predictive eye movement strategies that contribute towards their level of interceptive skill. Existing studies claim that (i) baseball and cricket batters cannot track the ball because it moves

  20. Kicking velocity and effect on match performance when using a smaller, lighter ball in women's football

    DEFF Research Database (Denmark)

    Andersen, Thomas B.; Krustrup, Peter; Bendiksen, Mads

    2016-01-01

    The present study evaluated the effect of a smaller, lighter ball on kicking speed and technical-tactical and physical match performance in high-level adult female footballers. In the laboratory test setting, the peak ball velocity was 6% higher with the new ball (NB) than the standard ball (SB...

  1. Comparison of exit time moment spectra for extrinsic metric balls

    DEFF Research Database (Denmark)

    Hurtado, Ana; Markvorsen, Steen; Palmer, Vicente

    2012-01-01

    We prove explicit upper and lower bounds for the $L^1$-moment spectra for the Brownian motion exit time from extrinsic metric balls of submanifolds $P^m$ in ambient Riemannian spaces $N^n$. We assume that $P$ and $N$ both have controlled radial curvatures (mean curvature and sectional curvature...... obtain new intrinsic comparison results for the exit time spectra for metric balls in the ambient manifolds $N^n$ themselves....

  2. Patient satisfaction of tooth supported overdentures utilizing ball attachments

    OpenAIRE

    Nassar, Hossam I.

    2016-01-01

    Statement of problem: Teeth retained overdenture therapy is an alternative treatment rarely used in cases with few remaining teeth. Purpose: The aim of this study was to evaluate the patient satisfaction associated with teeth retained maxillary and mandibular overdentures utilizing ready made ball attachment. Materials and methods: Thirty patients treated with teeth retained overdenture utilizing ready made ball attachment. Participants completed a series of questionnaires (OHIP-14 ques...

  3. Linearly convergent stochastic heavy ball method for minimizing generalization error

    KAUST Repository

    Loizou, Nicolas

    2017-10-30

    In this work we establish the first linear convergence result for the stochastic heavy ball method. The method performs SGD steps with a fixed stepsize, amended by a heavy ball momentum term. In the analysis, we focus on minimizing the expected loss and not on finite-sum minimization, which is typically a much harder problem. While in the analysis we constrain ourselves to quadratic loss, the overall objective is not necessarily strongly convex.

  4. Biaxial testing for nuclear grade graphite by ball on three balls assessment

    International Nuclear Information System (INIS)

    Mohd Reusmaazran Yusof; Yusof Abdullah

    2012-01-01

    Nuclear grade (high-purity) graphite for fuel element and moderator material in Advanced Gas Cooling Reactors (AGR) displays large scatter in strength and a non-linear stress-strain response from the damage accumulation. These responses can be characterized as quasi-brittle behaviour. Current assessments of fracture in core graphite components are based on the linear elastic approximation and thus represent a major assumption. The quasi-brittle behaviour gives challenge to assess the real nuclear graphite component. The selected test method would help to bridge the gap between microscale to macro-scale in real reactor component. The small scale tests presented here can contribute some statistical data to manifests the failure in real component. The evaluation and choice of different solution design of biaxial test will be discussed in this paper. The ball on-three ball test method was used for assessment test follows by numerous of analytical method. The results shown that biaxial strength of the EY9 grade graphite depends on the method used for evaluation. Some of the analytical methods use to calculate biaxial strength were found not to be valid and therefore should not be used to assess the mechanical properties of nuclear graphite. (author)

  5. Piston-like plugging of fuzzy-ball workover fluids for controlling and killing lost circulation of gas wells

    Directory of Open Access Journals (Sweden)

    Jinfeng Wang

    2016-01-01

    Full Text Available During well-killing operations for the workover of low-pressure gas wells, formation pressure should be balanced so as to guarantee well control safety by preventing natural gas overflow. In this paper, a laboratory evaluation was conducted with fuzzy-ball fluids as killing fluids. The results show that, the fuzzy-ball fluid, with a density of 0.5–1.5 g/cm3 and a viscosity up to 78,50,000 mPa·s at a low shear rate, realizes controllable performance and forms piston-like plugging slugs of solid-free high structural strength on natural gas wellbore after bonding. During well workover, multiple fluid column pressures were set up by injecting fuzzy-ball fluids with different densities at various rates. Owing to high structural strength of the fluids at a low shear rate, natural gas breaks through only inside the piston-like slug and cannot flow upwards to the ground, so the pathways of natural gas in the wellbore are isolated from the ground surface. Moreover, the fluid can wholly move up and down like a piston-like plug, with the change of formation pressures or the tripping of pipe strings. Like the conventional operations, the production can be restored after the workover, so long as the fluid in wellbore is cleaned by means of gas lift. In a natural gas field in NW China, where the formation pressure coefficient dropped to 0.60–0.82, three wells were fully filled with fuzzy-ball workover fluids for 7 days and another three wells were treated with the piston-like plugs of fuzzy-ball workover fluids for only 3 days. They all presented better technical results. The technology provides a new way for low-pressure gas well workover.

  6. Quenching simulation of steel grinding balls

    Directory of Open Access Journals (Sweden)

    Zapata-Hernández, Oscar

    2015-09-01

    Full Text Available The phase transformations of high carbon steel during quenching and equalizing were modelled using commercial computer packages based on the finite element method and the kinetic transformation of steel. The model was used to predict the temperature and microstructural changes taking place within balls of two different sizes that are used for grinding mineral ores. A good correlation between the temperatures measured by inserted thermocouples and those predicted by the model was obtained after modifying the thermal conductivity of the steel within the temperature domain at which mixed phases are present. The phase transformations predicted were confirmed by metallographic analyses.Las transformaciones de fase en aceros de alto carbono durante su temple y un posterior periodo de estabilización fueron modelizadas por medio del uso de paquetes computacionales basados en el método del elemento finito y de la transformación cinética de los aceros. El modelo se usó para predecir los cambios de temperatura y microestructura que se presentan en bolas de dos diferentes tamaños empleadas en estaciones de molienda de minerales. Se encontró una buena correlación entre las temperaturas medidas mediante la inserción de termopares y aquellas predichas por el modelo una vez que se modificó la conductividad térmica del acero en el intervalo mixto de fases. La predicción de las transformaciones de fase se confirmó a través del análisis metalográfico.

  7. Effort, performance, and motivation: insights from robot-assisted training of human golf putting and rat grip strength.

    Science.gov (United States)

    Duarte, Jaime E; Gebrekristos, Berkenesh; Perez, Sergi; Rowe, Justin B; Sharp, Kelli; Reinkensmeyer, David J

    2013-06-01

    Robotic devices can modulate success rates and required effort levels during motor training, but it is unclear how this affects performance gains and motivation. Here we present results from training unimpaired humans in a virtual golf-putting task, and training spinal cord injured (SCI) rats in a grip strength task using robotically modulated success rates and effort levels. Robotic assistance in golf practice increased trainees feelings of competence, and, paradoxically, increased their sense effort, even though it had mixed effects on learning. Reducing effort during a grip strength training task led rats with SCI to practice the task more frequently. However, the more frequent practice of these rats did not cause them to exceed the strength gains achieved by rats that exercised less often at higher required effort levels. These results show that increasing success and decreasing effort with robots increases motivation, but has mixed effects on performance gains.

  8. Report of ground water monitoring for expansion of the golf course, Salt Lake City, Utah, Vitro Processing Site. Revision 0

    International Nuclear Information System (INIS)

    1996-03-01

    Ground water elevations of the shallow unconfined aquifer have been monitored at the Uranium Mill Tailings Remedial Action (UMTRA) Project, Vitro Processing site, Salt Lake City, Utah, for the purposes of characterizing ground water flow conditions and evaluating the effects of irrigation of the golf driving range. Data collected, to date, show that the water table reached its highest level for the year during March and April 1995. From May through July 1995, the water table elevations decreased in most monitor wells due to less precipitation and higher evapotranspiration. Review and evaluation of collected data suggest that irrigation of the golf driving range will have negligible effects on water levels and ground water flow patterns if rates of irrigation do not significantly exceed future rates of evapotranspiration

  9. THE BEHAVIOURAL REACTION OF WEANERS TO HANGING TOYS: WOODEN BALL AND AROMATIZED WOODEN BALL – WAY TO REDUCE AGGRESSION AFTER MIXING

    Directory of Open Access Journals (Sweden)

    Jacek NOWICKI

    2008-05-01

    Full Text Available The behaviour of weaners after mixing housed in pens equipped with hanging wooden ball, aromatized with vanilla fluid hanging wooden ball and without enrichment was evaluated. It was found that both enrichments reduced aggression, however the most interesting for weaners was the aromatized wooden ball.

  10. Knowledge-guided golf course detection using a convolutional neural network fine-tuned on temporally augmented data

    Science.gov (United States)

    Chen, Jingbo; Wang, Chengyi; Yue, Anzhi; Chen, Jiansheng; He, Dongxu; Zhang, Xiuyan

    2017-10-01

    The tremendous success of deep learning models such as convolutional neural networks (CNNs) in computer vision provides a method for similar problems in the field of remote sensing. Although research on repurposing pretrained CNN to remote sensing tasks is emerging, the scarcity of labeled samples and the complexity of remote sensing imagery still pose challenges. We developed a knowledge-guided golf course detection approach using a CNN fine-tuned on temporally augmented data. The proposed approach is a combination of knowledge-driven region proposal, data-driven detection based on CNN, and knowledge-driven postprocessing. To confront data complexity, knowledge-derived cooccurrence, composition, and area-based rules are applied sequentially to propose candidate golf regions. To confront sample scarcity, we employed data augmentation in the temporal domain, which extracts samples from multitemporal images. The augmented samples were then used to fine-tune a pretrained CNN for golf detection. Finally, commission error was further suppressed by postprocessing. Experiments conducted on GF-1 imagery prove the effectiveness of the proposed approach.

  11. Design and Characterisation of Solid Electrolytes for All-Solid-State Lithium Batteries

    DEFF Research Database (Denmark)

    Sveinbjörnsson, Dadi Þorsteinn

    The development of all-solid-state lithium batteries, in which the currently used liquid electrolytes are substituted for solid electrolyte materials, could lead to safer batteries offering higher energy densities and longer cycle lifetimes. Designing suitable solid electrolytes with sufficient...... chemical and electrochemical stability, high lithium ion conduction and negligible electronic conduction remains a challenge. The highly lithium ion conducting LiBH4-LiI solid solution is a promising solid electrolyte material. Solid solutions with a LiI content of 6.25%-50% were synthesised by planetary......-rich microstructures during ball milling is found to significantly influence the conductivity of the samples. The long-range diffusion of lithium ions was measured using quasi-elastic neutron scattering. The solid solutions are found to exhibit two-dimensional conduction in the hexagonal plane of the crystal structure...

  12. The coefficient of restitution of pressurized balls: a mechanistic model

    Science.gov (United States)

    Georgallas, Alex; Landry, Gaëtan

    2016-01-01

    Pressurized, inflated balls used in professional sports are regulated so that their behaviour upon impact can be anticipated and allow the game to have its distinctive character. However, the dynamics governing the impacts of such balls, even on stationary hard surfaces, can be extremely complex. The energy transformations, which arise from the compression of the gas within the ball and from the shear forces associated with the deformation of the wall, are examined in this paper. We develop a simple mechanistic model of the dependence of the coefficient of restitution, e, upon both the gauge pressure, P_G, of the gas and the shear modulus, G, of the wall. The model is validated using the results from a simple series of experiments using three different sports balls. The fits to the data are extremely good for P_G > 25 kPa and consistent values are obtained for the value of G for the wall material. As far as the authors can tell, this simple, mechanistic model of the pressure dependence of the coefficient of restitution is the first in the literature. *%K Coefficient of Restitution, Dynamics, Inflated Balls, Pressure, Impact Model

  13. The goalkeeper influence on ball possession effectiveness in futsal

    Directory of Open Access Journals (Sweden)

    Vicente-Vila Pedro

    2016-06-01

    Full Text Available The aim of this study was to identify which variables were the best predictors of success in futsal ball possession when controlling for space and task related indicators, situational variables and the participation of the goalkeeper as a regular field player or not (5 vs. 4 or 4 vs. 4. The sample consisted of 326 situations of ball possession corresponding to 31 matches played by a team from the Spanish Futsal League during the 2010–2011, 2011–2012 and 2012–2013 seasons. Multidimensional qualitative data obtained from 10 ordered categorical variables were used. Data were analysed using chi-square analysis and multiple logistic regression analysis. Overall, the highest ball possession effectiveness was achieved when the goalkeeper participated as a regular field player (p<0.01, the duration of the ball possession was less than 10 s (p<0.01, the ball possession ended in the penalty area (p<0.01 and the defensive pressure was low (p<0.01. The information obtained on the relative effectiveness of offensive playing tactics can be used to improve team’s goal-scoring and goal preventing abilities.

  14. Effect of soccer shoe upper on ball behaviour in curve kicks

    Science.gov (United States)

    Ishii, Hideyuki; Sakurai, Yoshihisa; Maruyama, Takeo

    2014-08-01

    New soccer shoes have been developed by considering various concepts related to kicking, such as curving a soccer ball. However, the effects of shoes on ball behaviour remain unclear. In this study, by using a finite element simulation, we investigated the factors that affect ball behaviour immediately after impact in a curve kick. Five experienced male university soccer players performed one curve kick. We developed a finite element model of the foot and ball and evaluated the validity of the model by comparing the finite element results for the ball behaviour immediately after impact with the experimental results. The launch angle, ball velocity, and ball rotation in the finite element analysis were all in general agreement with the experimental results. Using the validated finite element model, we simulated the ball behaviour. The simulation results indicated that the larger the foot velocity immediately before impact, the larger the ball velocity and ball rotation. Furthermore, the Young's modulus of the shoe upper and the coefficient of friction between the shoe upper and the ball had little effect on the launch angle, ball velocity, and ball rotation. The results of this study suggest that the shoe upper does not significantly influence ball behaviour.

  15. Effect of Ball Weight on Speed, Accuracy, and Mechanics in Cricket Fast Bowling

    Directory of Open Access Journals (Sweden)

    Katharine L. Wickington

    2017-02-01

    Full Text Available The aims of this study were: (1 to quantify the acute effects of ball weight on ball release speed, accuracy, and mechanics in cricket fast bowling; and (2 to test whether a period of sustained training with underweight and overweight balls is effective in increasing a player’s ball release speed. Ten well-trained adult male cricket players performed maximum-effort deliveries using balls ranging in weight from 46% to 137% of the standard ball weight (156 g. A radar gun, bowling target, and 2D video analysis were used to obtain measures of ball speed, accuracy, and mechanics. The participants were assigned to either an intervention group, who trained with underweight and overweight balls, or to a control group, who trained with standard-weight balls. We found that ball speed decreased at a rate of about 1.1 m/s per 100 g increase in ball weight. Accuracy and bowling mechanics were not adversely affected by changes in ball weight. There was evidence that training with underweight and overweight balls might have produced a practically meaningful increase in bowling speed (>1.5 m/s in some players without compromising accuracy or increasing their risk of injury through inducing poor bowling mechanics. In cricket fast bowling, a wide range of ball weight might be necessary to produce an effective modified-implement training program.

  16. Magnetic properties of nanocrystalline Fe–10%Ni alloy obtained by planetary ball mills

    International Nuclear Information System (INIS)

    Hamzaoui, Rabah; Elkedim, Omar

    2013-01-01

    Highlights: •Solid solution formation accompanied by a grain refinement for nanocrystalline Fe-Ni. •The shock mode process (SMP) prevails when Ω > >ω. •The friction mode process (FMP) is stronger when Ω < <ω. •The FMP leads to the formation of alloys exhibiting a soft magnetic behavior. -- Abstract: Planetary ball mill PM 400 from Retsch (with different milling times for Ω = 400 rpm, ω = 800 rpm) and P4 vario ball mill from Fritsch (with different milling conditions (Ω/ω), Ω and ω being the disc and the vial rotation speeds, respectively) are used for obtaining nanocrystalline Fe–10wt% Ni. The structure and magnetic properties are studied by using X-ray diffraction, SEM and hysteresis measurements, respectively. The bcc-Fe(Ni) phase formation is identified by X-ray diffraction. The higher the shock power and the higher milling time are, the larger the bcc lattice parameter and the lower the grain size. The highest value of the coercivity is 1600 A/m for Fe–10 wt.%Ni (with shock mode (424 rpm/100 rpm) after 36 h of milling), while the lowest value is 189 A/m for (400 rpm/800 rpm) after 72 h of milling. The milling performed in the friction mode has been found to lead the formation of alloys exhibiting a soft magnetic behavior for nanocrystalline Fe–10%Ni

  17. A co-production of sugars, lignosulfonates, cellulose, and cellulose nanocrystals from ball-milled woods.

    Science.gov (United States)

    Du, Lanxing; Wang, Jinwu; Zhang, Yang; Qi, Chusheng; Wolcott, Michael P; Yu, Zhiming

    2017-08-01

    This study demonstrated the technical potential for the large-scale co-production of sugars, lignosulfonates, cellulose, and cellulose nanocrystals. Ball-milled woods with two particle sizes were prepared by ball milling for 80min or 120min (BMW 80 , BMW 120 ) and then enzymatically hydrolyzed. 78.3% cellulose conversion of BMW 120 was achieved, which was three times as high as the conversion of BMW 80 . The hydrolyzed residues (HRs) were neutrally sulfonated cooking. 57.72g/L and 88.16g/L lignosulfonate concentration, respectively, were harvested from HR 80 and HR 120 , and 42.6±0.5% lignin were removed. The subsequent solid residuals were purified to produce cellulose and then this material was acid-hydrolyzed to produce cellulose nanocrystals. The BMW 120 maintained smaller particle size and aspect ratio during each step of during the multiple processes, while the average aspect ratio of its cellulose nanocrystals was larger. The crystallinity of both materials increased with each step of wet processing, reaching to 74% for the cellulose. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Remote sensing technologies applied to the irrigation water management on a golf course

    Science.gov (United States)

    Pedras, Celestina; Lança, Rui; Martins, Fernando; Soares, Cristina; Guerrero, Carlos; Paixão, Helena

    2015-04-01

    An adequate irrigation water management in a golf course is a complex task that depends upon climate (multiple microclimates) and land cover (where crops differ in morphology, physiology, plant density, sensitivity to water stress, etc.). These factors change both in time and space on a landscape. A direct measurement provides localized values of the evapotranspiration and climate conditions. Therefore this is not a practical or economical methodology for large-scale use due to spatial and temporal variability of vegetation, soils, and irrigation management strategies. Remote sensing technology combines large scale with ground measurement of vegetation indexes. These indexes are mathematical combinations of different spectral bands mostly in the visible and near infrared regions of the electromagnetic spectrum. They represent the measures of vegetation activity that vary not only with the seasonal variability of green foliage, but also across space, thus they are suitable for detecting spatial landscape variability. The spectral vegetation indexes may enhance irrigation management through the information contained in spectral reflectance data. This study was carried out on the 18th fairway of the Royal Golf Course, Vale do Lobo, Portugal, and it aims to establish the relationship between direct measurements and vegetation indexes. For that it is required (1) to characterize the soil and climatic conditions, (2) to assessment of the irrigation system, (3) to estimate the evapotranspiration (4) and to calculate the vegetation indices. The vegetation indices were determined with basis on spectral bands red, green and blue, RGB, and near Infrared, NIR, obtained from the analysis of images acquired from a unpiloted aerial vehicle, UAV, platform. The measurements of reference evapotranspiration (ETo) were obtained from two meteorological stations located in the study area. The landscape evapotranspiration, ETL, was determined in the fairway with multiple microclimates

  19. Acoustic monitoring of a ball sinking in vibrated granular sediments

    Science.gov (United States)

    van den Wildenberg, Siet; Léopoldès, Julien; Tourin, Arnaud; Jia, Xiaoping

    2017-06-01

    We develop an ultrasound probing to investigate the dynamics of a high density ball sinking in 3D opaque dense granular suspensions under horizontal weak vibrations. We show that the motion of the ball in these horizontally vibrated glass bead packings saturated by water is consistent with the frictional rheology. The extracted stress-strain relation evidences an evolution of flow behaviour from frictional creep to inertial regimes. Our main finding is that weak external vibration primarily affects the yield stress and controls the depth of sinking via vibration-induced sliding at the grain contact. Also, we observe that the extracted rheological parameters depend on the size of the probing ball, suggesting thus a non-local rheology.

  20. Durability Tests of Ball Valve Prototype with Flowmeter Operation

    Science.gov (United States)

    Rogula, J.; Romanik, G.

    2018-02-01

    The results of the investigation of the prototypical ball valve are presented in this article. The innovation of the tested valve is a ball with a built-in measuring orifice. The valve has been subjected to durability tests. Leakage under three temperatures: ambient, -30°C and +100°C was analyzed. Sealing elements of the valve were tested for roughness and deviation of shape before and after the cycles of operation. Ball valve operation means cycles of open/close. It was planned to perform 1000 cycles at each temperature condition accordingly. Tests of the valve were performed under gas pressure equal to 10 MPa. The research was carried out under the Operational Program "Intelligent Development" (POIR 01.01.01-00-0013 / 15 "Development of devices for measurement of media flow on industrial trunk-lines".

  1. Geometric modeling in the problem of ball bearing accuracy

    Science.gov (United States)

    Glukhov, V. I.; Pushkarev, V. V.; Khomchenko, V. G.

    2017-06-01

    The manufacturing quality of ball bearings is an urgent problem for machine-building industry. The aim of the research is to improve the geometric specifications accuracy of bearings based on evidence-based systematic approach and the method of adequate size, location and form deviations modeling of the rings and assembled ball bearings. The present work addressed the problem of bearing geometric specifications identification and the study of these specifications. The deviation from symmetric planar of rings and bearings assembly and mounting width are among these specifications. A systematic approach to geometric specifications values and ball bearings tolerances normalization in coordinate systems will improve the quality of bearings by optimizing and minimizing the number of specifications. The introduction of systematic approach to the international standards on rolling bearings is a guarantee of a significant increase in accuracy of bearings and the quality of products where they are applied.

  2. A Case of Lung Lesions Induced by a soccer Ball

    Directory of Open Access Journals (Sweden)

    Masaaki Takemoto

    2013-01-01

    Full Text Available An 18-year-old youth soccer forward received a direct hit from a kicked soccer ball on the anterior right chest when the goal keeper kicked the ball from a distance of 1 meter. Immediately following the hit, the subject experienced dypnea, chest pain and had a cough, with several milliliters of hemoptysis. His symptoms subsided after 20 minutes of rest. However, he still felt mild discomfort and was taken to our department for evaluation. On examination, all vital signs were normal. A computed tomography scan of the chest was obtained, and revealed a small area of opacification in the right lung field suggesting a pulmonary contusion or traumatic lung edema. Ten days after the initial injury, he was cleared for full participation. We herein reported the first case of a lung lesion induced by a soccer ball. Conservative treatment resulted in a favorable outcome.

  3. Geometrical origin of chaoticity in the bouncing ball billiard

    International Nuclear Information System (INIS)

    Mátyás, L.; Barna, I.F.

    2011-01-01

    Highlights: ► We study the possible separation of neighouring trajectories in the bouncing ball billiard. ► In a certain interval of frequencies semianalitical evaluations are possible. ► One may find a lower bound for the maximal Lyapunov exponent in case of a resonance. - Abstract: We present a study of the chaotic behaviour of the bouncing ball billiard. The work is realised on the purpose of finding at least certain causes of separation of the neighbouring trajectories. Having in view the geometrical construction of the system, we report a clear origin of chaoticity of the bouncing ball billiard. By this we claim that in case when the floor is made of arc of circles – in a certain interval of frequencies – one can give semi-analytical estimates on chaotic behaviour.

  4. Stimulated leaks found with SmartBall tool

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    2011-05-15

    Pure Technologies has developed a SmartBall leak detection tool which can be used in oil and gas pipelines. This tool contains acoustic sensors which listen for leaks and other problems in pipelines. Pig tracking units are used to track the tool along with receivers positioned on the pipe. With these technologies, SmartBall is able to detect small leaks that conventional methods would not detect and to assess their location accurately. Two runs on a Petrobras pipeline in Brazil highlighted the effectiveness of this technology, detecting three simulated leaks as small as 240mL/min. In addition, this system can give an estimation of the leak rate and traverse non piggable pipelines. Software is then used to analyze data and generate a report giving the size and location of the leaks identified. SmartBall is a technology capable of detecting small leaks and locating them in all sorts of oil and gas pipelines.

  5. Study on the luminous characteristics of a natural ball lightning

    Science.gov (United States)

    Wang, Hao; Yuan, Ping; Cen, Jianyong; Liu, Guorong

    2018-02-01

    According to the optical images of the whole process of a natural ball lightning recorded by two slit-less spectrographs in the Qinghai plateau of China, the simulated observation experiment on the luminous intensity of the spherical light source was carried out. The luminous intensity and the optical power of the natural ball lightning in the wavelength range of 400-690 nm were estimated based on the experimental data and the Lambert-Beer Law. The results show that the maximum luminous intensity was about 1.24 × 105 cd in the initial stage of the natural ball lightning, and the maximum luminous intensity and the maximum optical power in most time of its life were about 5.9 × 104 cd and 4.2 × 103 W, respectively.

  6. Validation of single ball rolling contact fatigue machine dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Allison, Bryan [SKF Aeroengine, Falconer (United States)

    2017-01-15

    Single ball test machines are a common method for accelerated rolling contact fatigue testing of bearing materials. Historically, it has always been assumed that the force applied by the retaining bars is negligible, without any data to support this claim. In this study, strain gauges were placed on the retaining bars to determine the load experienced by the retaining bars. This value was then compared to the applied load. It was found that a load of approximately 4 N was transferred to the retainer by the test ball during steady state operation, when a 8385 N load was applied to the ball via the rings. A simulation of the system was also created and successfully predicted the expected loads with reasonable accuracy. This information, as well as the technique of strain gauging the retaining bars, may be useful in the development of similar testing machinery.

  7. Supermassive dark-matter Q-balls in galactic centers?

    Energy Technology Data Exchange (ETDEWEB)

    Troitsky, Sergey [Institute for Nuclear Research of the Russian Academy of Sciences,60th October Anniversary Prospect 7a, Moscow 117312 (Russian Federation); Moscow Institute for Physics and Technology,Institutskii per. 9, 141700, Dolgoprudny, Moscow Region (Russian Federation)

    2016-11-11

    Though widely accepted, it is not proven that supermassive compact objects (SMCOs) residing in galactic centers are black holes. In particular, the Milky Way’s SMCO can be a giant nontopological soliton, Q-ball, made of a scalar field: this fits perfectly all observational data. Similar but tiny Q-balls produced in the early Universe may constitute, partly or fully, the dark matter. This picture explains in a natural way, why our SMCO has very low accretion rate and why the observed angular size of the corresponding radio source is much smaller than expected. Interactions between dark-matter Q-balls may explain how SMCOs were seeded in galaxies and resolve well-known problems of standard (non-interacting) dark matter.

  8. Simulating fullerene ball bearings of ultra-low friction

    International Nuclear Information System (INIS)

    Li Xiaoyan; Yang Wei

    2007-01-01

    We report the direct molecular dynamics simulations for molecular ball bearings composed of fullerene molecules (C 60 and C 20 ) and multi-walled carbon nanotubes. The comparison of friction levels indicates that fullerene ball bearings have extremely low friction (with minimal frictional forces of 5.283 x 10 -7 and 6.768 x 10 -7 nN/atom for C 60 and C 20 bearings) and energy dissipation (lowest dissipation per cycle of 0.013 and 0.016 meV/atom for C 60 and C 20 bearings). A single fullerene inside the ball bearings exhibits various motion statuses of mixed translation and rotation. The influences of the shaft's distortion on the long-ranged potential energy and normal force are discussed. The phonic dissipation mechanism leads to a non-monotonic function between the friction and the load rate for the molecular bearings

  9. Conceptual design of ball-screw type control element drive mechanism

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ji Ho; Kim, Jong In; Huh, Hyung [Korea Atomic Energy Research Institute, Taejon (Korea)

    1999-10-01

    In this report, the design features of ball-screw type CEDM with fine-step movement capability are described. The contents of this report are as follows: -Review of Design Requirements for Ball-screw type CEDM -System Description for Ball-screw type CEDM -Design of Ball Bearing and Ball-screw Assembly -Detail Design of Rotary Step Motor -Detail Design of Angular Position Indicator -Materials. The Ball-screw type CEDM described in this report is to be utilized as the starting point for design development of CEDM for SMART. 11 refs., 43 figs., 3 tabs. (Author)

  10. A self-similar magnetohydrodynamic model for ball lightnings

    International Nuclear Information System (INIS)

    Tsui, K. H.

    2006-01-01

    Ball lightning is modeled by magnetohydrodynamic (MHD) equations in two-dimensional spherical geometry with azimuthal symmetry. Dynamic evolutions in the radial direction are described by the self-similar evolution function y(t). The plasma pressure, mass density, and magnetic fields are solved in terms of the radial label η. This model gives spherical MHD plasmoids with axisymmetric force-free magnetic field, and spherically symmetric plasma pressure and mass density, which self-consistently determine the polytropic index γ. The spatially oscillating nature of the radial and meridional field structures indicate embedded regions of closed field lines. These regions are named secondary plasmoids, whereas the overall self-similar spherical structure is named the primary plasmoid. According to this model, the time evolution function allows the primary plasmoid expand outward in two modes. The corresponding ejection of the embedded secondary plasmoids results in ball lightning offering an answer as how they come into being. The first is an accelerated expanding mode. This mode appears to fit plasmoids ejected from thundercloud tops with acceleration to ionosphere seen in high altitude atmospheric observations of sprites and blue jets. It also appears to account for midair high-speed ball lightning overtaking airplanes, and ground level high-speed energetic ball lightning. The second is a decelerated expanding mode, and it appears to be compatible to slowly moving ball lightning seen near ground level. The inverse of this second mode corresponds to an accelerated inward collapse, which could bring ball lightning to an end sometimes with a cracking sound

  11. The Energy Cost of Running with the Ball in Soccer.

    Science.gov (United States)

    Piras, Alessandro; Raffi, Milena; Atmatzidis, Charalampos; Merni, Franco; Di Michele, Rocco

    2017-11-01

    Running with the ball is a soccer-specific activity frequently used by players during match play and training drills. Nevertheless, the energy cost (EC) of on-grass running with the ball has not yet been determined. The purpose of this study was therefore to assess the EC of constant-speed running with the ball, and to compare it with the EC of normal running. Eight amateur soccer players performed two 6- min runs at 10 km/h on artificial turf, respectively with and without the ball. EC was measured with indirect calorimetry and, furthermore, estimated with a method based on players' accelerations measured with a GPS receiver. The EC measured with indirect calorimetry was higher in running with the ball (4.60±0.42 J/kg/m) than in normal running (4.19±0.33 J/kg/m), with a very likely moderate difference between conditions. Instead, a likely small difference was observed between conditions for EC estimated from GPS data (4.87±0.07 vs. 4.83±0.08 J/kg/m). This study sheds light on the energy expenditure of playing soccer, providing relevant data about the EC of a typical soccer-specific activity. These findings may be a reference for coaches to precisely determine the training load in drills with the ball, such as soccer-specific circuits or small-sided games. © Georg Thieme Verlag KG Stuttgart · New York.

  12. A power recirculating test rig for ball screw endurance tests

    Directory of Open Access Journals (Sweden)

    Giberti Hermes

    2016-01-01

    Full Text Available A conceptual design of an innovative test rig for endurance tests of ball screws is presented in this paper. The test rig layout is based on the power recirculating principle and it also allows to overtake the main critical issues of the ball screw endurance tests. Among these there are the high power required to make the test, the lengthy duration of the same and the high loads between the screw and the frame that holds it. The article describes the test rig designed scheme, the kinematic expedients to be adopted in order to obtain the required performance and functionality and the sizing procedure to choose the actuation system.

  13. Some results on rotating fluid balls of Petrov type D

    Energy Technology Data Exchange (ETDEWEB)

    Bradley, M [Department of Physics, Umeaa University, SE-901 87 Umeaa (Sweden); Eriksson, D [Department of Physics, Umeaa University, SE-901 87 Umeaa (Sweden); Fodor, G [KFKI Research Institute for Particle and Nuclear Physics, H-1525, Budapest 114, P.O.B. 49 (Hungary); Racz, I [KFKI Research Institute for Particle and Nuclear Physics, H-1525, Budapest 114, P.O.B. 49 (Hungary)

    2007-05-15

    The second order perturbative field equations for slowly and rigidly rotating perfect fluid balls of Petrov type D are solved numerically. It is found that all the slowly and rigidly rotating perfect fluid balls up to second order, irrespective of Petrov type, may be matched to a possibly non-asymptotically flat stationary axisymmetric vacuum exterior. A subspace of the parameter space is identified for which the solutions can be matched to an asymptotically flat exterior vacuum region. The physical properties like equations of state, shapes and speeds of sound are determined for a number of solutions.

  14. Note: A 1-m Foucault pendulum rolling on a ball

    Science.gov (United States)

    Salva, H. R.; Benavides, R. E.; Venturino, J. A.; Cuscueta, D. J.; Ghilarducci, A. A.

    2013-10-01

    We have built a short Foucault pendulum of 1-m length. The aim of this work was to increase the sensitivity to elliptical trajectories from other longer pendula. The design was a semi-rigid pendulum that rolls over a small ball. The measurements of the movements (azimuth and elliptical trajectory) were done by an optical method. The resulting pendulum works in a medium satisfactory way due to problems of the correct choice of the mass of the bob together with the diameter of the supporting ball. It is also important to keep the rolling surface very clean.

  15. Ball Bearing Stiffnesses- A New Approach Offering Analytical Expressions

    Science.gov (United States)

    Guay, Pascal; Frikha, Ahmed

    2015-09-01

    Space mechanisms use preloaded ball bearings in order to withstand the severe vibrations during launch.The launch strength requires the calculation of the bearing stiffness, but this calculation is complex. Nowadays, there is no analytical expression that gives the stiffness of a bearing. Stiffness is computed using an iterative algorithm such as Newton-Raphson, to solve the nonlinear system of equations.This paper aims at offering a simplified analytical approach, based on the assumption that the contact angle is constant. This approach gives analytical formulas of the stiffness of preloaded ball bearing.

  16. Ball lightning dynamics and stability at moderate ion densities

    International Nuclear Information System (INIS)

    Morrow, R

    2017-01-01

    A general mechanism is presented for the dynamics and structure of ball lightning and for the maintenance of the ball lightning structure for several seconds. Results are obtained using a spherical geometry for air at atmospheric pressure, by solving the continuity equations for electrons, positive ions and negative ions coupled with Poisson’s equation. A lightning strike can generate conditions in the lightning channel with a majority of positive nitrogen ions, and a minority of negative oxygen ions and electrons. The calculations are initiated with electrons included; however, at the moderate ion densities chosen the electrons are rapidly lost to form negative ions, and after 1 µ s their influence on the ion dynamics is negligible. Further development after 1 µ s is followed using a simpler set of equations involving only positive ions and negative ions, but including ion diffusion. The space-charge electric field generated by the majority positive ions drives them from the centre of the distribution and drives the minority negative ions and electrons towards the centre of the distribution. In the central region the positive and negative ion distributions eventually overlap exactly and their space-charge fields cancel resulting in zero electric field, and the plasma ball formed is quite stable for a number of seconds. The formation of such plasma balls is not critically dependent on the initial diameter of the ion distributions, or the initial density of minority negative ions. The ion densities decrease relatively slowly due to mutual neutralization of positive and negative ions. The radiation from this neutralization process involving positive nitrogen ions and negative oxygen ions is not sufficient to account for the reported luminosity of ball lightning and some other source of luminosity is shown to be required; the plasma ball model used could readily incorporate other ions in order to account for the luminosity and range of colours reported for ball

  17. Study of Complexities in Bouncing Ball Dynamical System

    Directory of Open Access Journals (Sweden)

    Lal Mohan SAHA

    2016-04-01

    Full Text Available Evolutionary motions in a bouncing ball system consisting of a ball having a free fall in the Earth’s gravitational field have been studied systematically. Because of nonlinear form of the equations of motion, evolutions show chaos for certain set of parameters for certain initial conditions. Bifurcation diagram has been drawn to study regular and chaotic behavior. Numerical calculations have been performed to calculate Lyapunov exponents, topological entropies and correlation dimension as measures of complexity. Numerical results are shown through interesting graphics.

  18. Ball milling of chalcopyrite: Moessbauer spectroscopy and XRD studies

    International Nuclear Information System (INIS)

    Pollak, H.; Fernandes, M.; Levendis, D.; Schonig, L.

    1999-01-01

    The aim of this project is to study the behavior of chalcopyrite under ball milling for extended periods in order to determine how it's decompose or transform. Tests were done with chalcopyrite mixed with iron and zinc with and without surfactant. The use of surfactants has various effects such as avoiding oxidation and clustering of the fine particles. In all case magnetic chalcopyrite is transformed into a paramagnetic component showing a disordered structure, thus revealing that Cu atoms have replaced Fe atoms. In the case of ball milling in air, chalcopyrite is decomposed with the lost of iron, while in milling under surfactants, iron enters into the chalcopyrite structure. (author)

  19. Charge, mass and energy measured in the Plastic Ball

    International Nuclear Information System (INIS)

    Gustafsson, H.A.; Gutbrod, H.H.; Kolb, B.

    1984-01-01

    In relativistic nuclear collisions the multiplicity of charged particles reflects the violence of the reaction and, presumably, the impact parameter. Furthermore, the total transverse energy in a collision might be a signature of compression. Both quantities are global features that can be measured in the Plastic Ball. The total mass in an event in light charge fragments can be detected (with assumptions made in certain kinematic regions) through particle identification. In addition, the neutron detection efficiency is quite high because of the large thickness of the plastic scintillator in the Plastic Ball. Here the authors present several global quantities for the reaction of 400 MeV/nucleon Nb + Nb

  20. Design and performance of a modularized NaI(Tl) detector (the crystal ball prototype)

    International Nuclear Information System (INIS)

    Chan, Y.; Partridge, R.A.; Peck, C.W.

    1977-01-01

    A prototype NaI(Tl) detector (the Cluster of 54) of spherical geometry subtending a solid angle of 7.5 percent of 4π at its center, has recently been assembled and tested. This detector consisted of 54 close-packed but optically isolated NaI(Tl) modules and the associated electronic circuitry. The Cluster of 54 is the predecessor of an almost complete spherical detector, the Crystal Ball, which will cover 94 percent of 4π. The latter detector is now under construction and is especially designed for the study of γ-rays produced in electron-positron collisions at colliding beam facilities. The mechanical, optical, and electronic assembly of the prototype system is outlined. Cluster of 54 test data will be presented

  1. Compact multiwire proportional chambers and electronics for the crystal ball detector

    International Nuclear Information System (INIS)

    Gaiser, J.E.; Liberman, A.D.; Rolfe, J.

    1978-01-01

    A double gap of cylindrical proportional chambers has been designed and built for use with a large solid angle, modular NaI(Tl) array (The Crystal Ball). The chambers are constructed of three coaxial foam-epoxy shells, covered with an aluminum-mylar laminate. One of the high voltage cathodes in each chamber has been photo-etched to produce a pattern of stripes and precise position measurements of tracks passing transverse to the chamber axis are found by pulse height analyzing the shaped and amplified induced strip signals. Performance of the chamber using both the strip signals and the sense wire readout is presented. The design of both the signal handling electronics and the digital portions of the systems is discussed

  2. Basaloid Squamous Cell Carcinoma: An Unusual Ball-Valve Laryngeal Obstruction

    Directory of Open Access Journals (Sweden)

    Sien Hui Tan

    2015-05-01

    Full Text Available Introduction: A rare case of basaloid squamous cell carcinoma (BSCC of the larynx, which has not been previously reported, is described. Case Report: A 60-year-old man was presented to the Otolaryngology Department with progressive dyspnoea and dysphagia to solids for over a period of 1 week. Direct laryngoscopy revealed a tumour at the laryngeal aspect of the epiglottis, which prolapsed into the laryngeal inlet each time the patient inspired. This resulted in an inspiratory stridor despite adequate glottic opening and normal mobility of the vocal cords.   Conclusion:  Therefore, in cases where a ball-valve lesion causes intermittent life-threatening airway obstruction, BSCC of the larynx, though rare, must be considered as a differential diagnosis.

  3. Magnetic Properties of Nanocrystalline FexCu1-x Alloys Prepared by Ball Milling

    International Nuclear Information System (INIS)

    Yousif, A.; Bouziane, K.; Elzain, M. E.; Ren, X.; Berry, F. J.; Widatallah, H. M.; Al Rawas, A.; Gismelseed, A.; Al-Omari, I. A.

    2004-01-01

    X-ray diffraction, Moessbauer and magnetization measurements were used to study Fe x Cu 1-x alloys prepared by ball-milling. The X-ray data show the formation of a nanocrystalline Fe-Cu solid solution. The samples with x≥0.8 and x≤0.5 exhibit bcc or fcc phase, respectively. Both the bcc and fcc phases are principally ferromagnetic for x≥0.2, but the sample with x=0.1 remains paramagnetic down to 78 K. The influence of the local environment on the hyperfine parameters and the local magnetic moment are discussed using calculations based on the discrete-variational method in the local density approximation.

  4. Integrated geophysical survey in defining subsidence features on a golf course

    Science.gov (United States)

    Xia, J.; Miller, R.D.

    2007-01-01

    Subsidence was observed at several places on the Salina Municipal Golf Course in areas known to be built over a landfill in Salina, Kansas. High-resolution magnetic survey (???5400 m2), multi-channel electrical resistivity profiling (three 154 m lines) and microgravity profiling (23 gravity-station values) were performed on a subsidence site (Green 16) to aid in determining boundaries and density deficiency of the landfill in the vicinity of the subsidence. Horizontal boundaries of the landfill were confidently defined by both magnetic anomalies and the pseudo-vertical gradient of total field magnetic anomalies. Furthermore, the pseudo-vertical gradient of magnetic anomalies presented a unique anomaly at Green 16, which provided a criterion for predicting other spots with subsidence potential using the same gradient property. Results of multi-channel electrical resistivity profiling (ERP) suggested the bottom limit of the landfill at Green 16 was around 21 m below the ground surface based on the vertical gradient of electric resistivity and a priori information on the depth of the landfill. ERP results also outlined several possible landfill bodies based on their low resistivity values. Microgravity results suggested a -0.14 g cm-3 density deficiency at Green 16 that could equate to future surface subsidence of as much as 1.5 m due to gradual compaction. ?? 2007 Nanjing Institute of Geophysical Prospecting.

  5. Resolution of low-velocity control in golf putting differentiates professionals from amateurs.

    Science.gov (United States)

    Hasegawa, Yumiko; Fujii, Keisuke; Miura, Akito; Yamamoto, Yuji

    2017-07-01

    It is difficult for humans to apply small amounts of force precisely during motor control. However, experts who have undergone extended training are thought to be able to control low-velocity movement with precision. We investigated the resolution of motor control in golf putting. A total of 10 professional and 10 high-level amateur golfers participated. Putting distances were 0.6-3.3 m, in increments of 0.3 m. We measured the impact velocity and the club-face angle at impact, and the acceleration profile of the downswing. The professionals showed significantly smaller coefficients of variation with respect to impact velocity and smaller root mean square errors in relation to acceleration profiles than did the amateurs. To examine the resolution of motor control for impact velocity, we investigated intra-participant differences in the impact velocity of the club head at two adjacent distances. We found that professionals had higher velocity precision when putting small distance intervals than did amateurs. That is, professionals had higher resolution of low-velocity control than did high-level amateurs. Our results suggest that outstanding performance at a task involves the ability to recognise small distinctions and to produce appropriate movements.

  6. Spine biomechanics associated with the shortened, modern one-plane golf swing.

    Science.gov (United States)

    Dale, R Barry; Brumitt, Jason

    2016-06-01

    The purpose of this study was to compare kinetic, kinematic, and performance variables associated with full and shortened modern backswings in a skilled group of modern swing (one-plane) golfers. Shortening the modern golf backswing is proposed to reduce vertebral spine stress, but supporting evidence is lacking and performance implications are unknown. Thirteen male golfers performed ten swings of each swing type using their own 7-iron club. Biomechanical-dependent variables included the X-Factor kinematic data and spine kinetics. Performance-related dependent variables included club head velocity (CHV), shot distance, and accuracy (distance from the target line). Data were analysed with repeated measures ANOVA with an a priori alpha of 0.05 (SPSS 22.0, IBM, Armonk, NY, USA). We found significant reductions for the X-Factor (p < 0.05) between the full and shortened swings. The shortened swing condition ameliorated vertebral compression force from 7.6 ± 1.4 to 7.0 ± 1.7 N (normalised to body weight, p = 0.01) and significantly reduced CHV (p < 0.05) by ~2 m/s with concomitant shot distance diminution by ~10 m (p < 0.05). Further research is necessary to examine the applicability of a shortened swing for golfers with low back pain.

  7. Proton Exchange Membrane Fuel Cell/Supercapasitor Hybrid Power Management System for a Golf Cart

    International Nuclear Information System (INIS)

    Siti Afiqah Abd Hamid; Ros Emilia Rosli; Edy Herianto Majlan; Wan Ramli Wan Daud; Ramizi Mohamed; Ramli Sitanggang

    2016-01-01

    This paper presented the transformation of a golf cart system powered lead acid battery into an environmental friendly hybrid vehicle. The design developed by using an advantage contributes by the uprising alternative power source candidate which is Proton Exchange Membrane Fuel Cell (PEMFC) and the maintenance free energy storage device, a supercapacitor (SC). The fuel cell (FC) stack was an in house manufactured with 450 W (36 V, 12.5 A) power, while the SC was from Maxwell Technologies (48 V, 165 F). This two power sources were controlled by the mechanical relay, meanwhile the reactant (hydrogen) are control by mass flow controller (MFC) both signaled by a National Instrument (NI) devices. The power management controller are programmed in the LabVIEW environment and then downloaded to the NI devices. The experimental result of the power trend was compared before and after the transformation with the same route to validate the effectiveness of the proposed power management strategy. The power management successfully controls the power sharing between power sources and satisfies the load transient. While the reactant control managed to vary the hydrogen mass flow rate feed according to the load demand in vehicular applications. (author)

  8. Magnetic and mechanical properties of Cu (75 wt%) – 316L grade stainless steels synthesized by ball milling and annealing

    Energy Technology Data Exchange (ETDEWEB)

    Mondal, Bholanath, E-mail: bholanath_mondal@yahoo.co.in [Department of Central Scientific Services, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032 (India); Chabri, Sumit [Department of Metallurgy and Materials Engineering, Indian Institute of Engineering Science and Technology, Shibpur, Howrah 711103 (India); Sardar, Gargi [Department of Zoology, Baruipur College, South 24 Parganas, 743610 (India); Bhowmik, Nandagopal [Department of Metallurgy and Materials Engineering, Indian Institute of Engineering Science and Technology, Shibpur, Howrah 711103 (India); Sinha, Arijit, E-mail: arijitsinha2@yahoo.co.in [School of Materials Science and Engineering, Indian Institute of Engineering Science and Technology, Shibpur, Howrah 711103 (India); Chattopadhyay, Partha Protim [Department of Metallurgy and Materials Engineering, Indian Institute of Engineering Science and Technology, Shibpur, Howrah 711103 (India)

    2015-05-01

    Elemental powders of Cu (75 wt%) and 316-stainless steel (25 wt%) has been subjected to ball milling upto 70 h followed by isothermal annealing at the temperature range of 350–750 °C for 1 h to investigate the microstructural evolution along with magnetic and mechanical properties. After 40 h of milling, the bcc Fe is almost dissolved in the solid solution of Cu but no significant change has been observed in the XRD pattern after 70 h of milling, Annealing of the alloy has resulted in precipitation of nanocrystalline bcc-Fe in Cu which triggers the soft ferromagnetic properties. The extensive mechanical characterization has been done at the microstructural scale by nanoindentation technique which demonstrates a hardening behavior of the compacted and annealed alloys due to possible precipitation of nanocrystalline bcc-Fe in Cu. - Highlights: • Nanocrystalline phases with partial amorphorization obtained after 70 h of milling. • Precipitation and grain coarsening of Fe and Cu after annealing as observed by XRD. • Annealing of the ball milled sample upto 550 {sup o}C has evolved ferromagnetic behavior. • Nanoindentation predicts a hardening behavior of annealed ball milled samples.

  9. Hydroamination reactions of alkynes with ortho-substituted anilines in ball mills: synthesis of benzannulated N-heterocycles by a cascade reaction.

    Science.gov (United States)

    Weiße, Maik; Zille, Markus; Jacob, Katharina; Schmidt, Robert; Stolle, Achim

    2015-04-20

    It was demonstrated that ortho-substituted anilines are prone to undergo hydroamination reactions with diethyl acetylenedicarboxylate in a planetary ball mill. A sequential coupling of the intermolecular hydroamination reaction with intramolecular ring closure was utilized for the syntheses of benzooxazines, quinoxalines, and benzothiazines from readily available building blocks, that is, electrophilic alkynes and anilines with OH, NH, or SH groups in the ortho position. For the heterocycle formation, it was shown that several stress conditions were able to initiate the reaction in the solid state. Processing in a ball mill seemed to be advantageous over comminution with mortar and pestle with respect to process control. In the latter case, significant postreaction modification occurred during solid-state analysis. Cryogenic milling proved to have an adverse effect on the molecular transformation of the reagents. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Caracterização química e granulométrica de solos do Golfão maranhense Chemical and granulometric caracterization of soils in the Golfão Maranhense

    Directory of Open Access Journals (Sweden)

    Gustavo Souza Valladares

    2009-01-01

    Full Text Available A área de estudo corresponde aos campos flúvio-marinhos com risco de inundação e presença de solos hidromórficos da região do Golfão Maranhense. Os solos dessa região apresentam algum impedimento a drenagem, proximidade com o mar (fonte de sais, condições favoráveis a inundação e aos processos de evaporação. Este conjunto de fatores pode elevar as concentrações de sais solúveis e inviabilizar ou reduzir a produtividade. Foram coletadas 38 amostras de solo em 22 pontos com trado holandês a profundidades variáveis, normalmente de 0 a 20 e de 30 a 50 cm. As amostras foram secas ao ar e analisados atributos químicos e granulométricos. Os solos do golfão maranhense apresentam grande variabilidade e predominam os com argila de atividade alta, alta soma de bases e altos teores de hidrogênio e alumínio. Os teores de magnésio são predominantes em relação aos de cálcio. Apesar da maioria dos solos apresentarem textura argilosa a granulometria é bastante variável. Mesmo com altos teores de magnésio e de sódio o grau de floculação das amostras pode ser considerado alto. Os solos do Golfão Maranhense não se encontram salinizados, porém é necessário manejá-los de maneira adequada para não promover sua salinização.The study area of this study corresponds to fluviomarine fields with flood risk and the presence of hydromorphic soils in the Golfão Maranhense region. The soils of the area present slow drenage, proximity with the sea (salt source and favorable conditions for flood, and evaporation processes. All these factors may increase the concentration of soluble salts and reduce productivity or make it inviable. We collected 38 soil samples in 22 points at variable depths, normally between 0 to 20 and 30 to 50 cm. The samples were air dried and their chemical and granulometric attributes analyzed. The soil of Golfão Maranhense presents high variability of chemical and granulometric attributes, and is predominant

  11. Effect of panel shape of soccer ball on its flight characteristics

    Science.gov (United States)

    Hong, Sungchan; Asai, Takeshi

    2014-05-01

    Soccer balls are typically constructed from 32 pentagonal and hexagonal panels. Recently, however, newer balls named Cafusa, Teamgeist 2, and Jabulani were respectively produced from 32, 14, and 8 panels with shapes and designs dramatically different from those of conventional balls. The newest type of ball, named Brazuca, was produced from six panels and will be used in the 2014 FIFA World Cup in Brazil. There have, however, been few studies on the aerodynamic properties of balls constructed from different numbers and shapes of panels. Hence, we used wind tunnel tests and a kick-robot to examine the relationship between the panel shape and orientation of modern soccer balls and their aerodynamic and flight characteristics. We observed a correlation between the wind tunnel test results and the actual ball trajectories, and also clarified how the panel characteristics affected the flight of the ball, which enabled prediction of the trajectory.

  12. Noninvasive medical management of fungus ball uropathy in a premature infant.

    Science.gov (United States)

    Alkalay, A L; Srugo, I; Blifeld, C; Komaiko, M S; Pomerance, J J

    1991-09-01

    Unilateral renal obstruction secondary to fungus balls is described in a premature infant. Noninvasive medical management, which included amphotericin B and 5-flucytosine therapy and forced diuresis, resulted in disappearance of fungus balls and resolution of the obstruction.

  13. Improved determination of dynamic balance using the centre of mass and centre of pressure inclination variables in a complete golf swing cycle.

    Science.gov (United States)

    Choi, Ahnryul; Sim, Taeyong; Mun, Joung Hwan

    2016-01-01

    Golf requires proper dynamic balance to accurately control the club head through a harmonious coordination of each human segment and joint. In this study, we evaluated the ability for dynamic balance during a golf swing by using the centre of mass (COM)-centre of pressure (COP) inclination variables. Twelve professional, 13 amateur and 10 novice golfers participated in this study. Six infrared cameras, two force platforms and SB-Clinic software were used to measure the net COM and COP trajectories. In order to evaluate dynamic balance ability, the COM-COP inclination angle, COM-COP inclination angular velocity and normalised COM-COP inclination angular jerk were used. Professional golfer group revealed a smaller COM-COP inclination angle and angular velocity than novice golfer group in the lead/trail direction (P golf injuries.

  14. Ovarian cystic teratoma containing balls of fat. A case report

    International Nuclear Information System (INIS)

    Salinas, A.; Rebolledo, M.; Escribano, M.; Alejo, J. P.; Morenom, J.

    1998-01-01

    We present the case of a ovarian cystic teratoma characterized predominantly by the mobile balls floating in the intra cystic fluid. Ultrasonography demonstrated their marked echo reflectivity and computed tomography revealed that they had the density of fat. We establish a relationship among the ultrasound, computed tomography and histological findings in this uncommon type of ovarian cystic teratoma. (Author) 6 refs

  15. Generalized isoperimetric inequalities for extrinsic balls in minimal submanifolds

    DEFF Research Database (Denmark)

    Markvorsen, Steen; Palmer, Vicente

    2002-01-01

    The volume of an extrinsic ball in a minimal submanifold has a well defined lower bound when the ambient manifold has an upper bound on its sectional curvatures, see e.g. [2] and [10]. When this upper bound is non-positive, the second named author has shown an isoperimetric inequality for such do...

  16. Thump, ring: the sound of a bouncing ball

    Energy Technology Data Exchange (ETDEWEB)

    Katz, J I, E-mail: katz@wuphys.wustl.ed [Department of Physics and McDonnell Center for the Space Sciences, Washington University, St Louis, MO 63130 (United States)

    2010-07-15

    A basketball bounced on a stiff surface produces a characteristic loud thump, followed by a high-pitched ringing. Describing the ball as an inextensible but flexible membrane containing compressed air, I formulate an approximate theory of the generation of these sounds and predict their amplitudes and waveforms.

  17. Thump, ring: the sound of a bouncing ball

    International Nuclear Information System (INIS)

    Katz, J I

    2010-01-01

    A basketball bounced on a stiff surface produces a characteristic loud thump, followed by a high-pitched ringing. Describing the ball as an inextensible but flexible membrane containing compressed air, I formulate an approximate theory of the generation of these sounds and predict their amplitudes and waveforms.

  18. High-Energy Ball-Milling of Alloys and Compounds

    International Nuclear Information System (INIS)

    Le Caer, G.; Delcroix, P.; Begin-Colin, S.; Ziller, T.

    2002-01-01

    After outlining some characteristics of high-energy ball-milling, we discuss selected examples of phase transformation and of alloy synthesis which focus on deviations from archetypal behaviours and throw light on the milling mechanisms. Some contributions of Moessbauer spectrometry to the characterization of ground materials are described.

  19. Reduced graphene oxide synthesis by high energy ball milling

    Energy Technology Data Exchange (ETDEWEB)

    Mondal, O. [Department of Physics, M.U.C Women' s College, Burdwan 713104 (India); Mitra, S. [MLS Prof' s Unit, Indian Association for the Cultivation of Science, Kolkata 700032 (India); Pal, M. [CSIR-Central Glass and Ceramic Research Institute, Kolkata 700032 (India); Datta, A. [University School of Basic and Applied Science (USBAS), Guru Gobind Singh Indraprastha University, New Delhi 110075 (India); Dhara, S. [Surface and Nanoscience Division, Indira Gandhi Centre for Atomic Research, Kalpakkam 603102 (India); Chakravorty, D., E-mail: mlsdc@iacs.res.in [MLS Prof' s Unit, Indian Association for the Cultivation of Science, Kolkata 700032 (India)

    2015-07-01

    Graphene oxide is transformed to reduced graphene oxide by high energy ball milling in inert atmosphere. The process of ball milling introduces defects and removes oxygen functional groups, thereby creating the possibility of fine tuning the band gap of all intermediate stages of the structural evolution. A limit of the backbone sp{sup 2} network structure has been found which should be able to accommodate defects, before amorphization sets in. The amorphization of graphene oxide is achieved rather quickly in comparison to that of graphite. From thermogravimetric and differential scanning calorimetric analysis along with Fourier transform infrared (FTIR) and Raman spectroscopic studies, it is found that the number of oxygen-containing groups decreases at a faster rate than that of aromatic double bonds with increasing ball milling time with a maximum limit of 3 h. Several characterization techniques (FTIR, Raman, UV–Visible and X-ray photoelectron spectroscopy) have confirmed that the material synthesized is, indeed, reduced graphene oxide. - Highlights: • Graphene oxide is transformed to reduced graphene oxide by high energy ball milling in inert atmosphere. • Fine tuning the band gap by introducing defects and removing oxygen functional groups. • Introduction of excess defects leads to amorphization. • Photoluminescence has been observed in the UV-blue region.

  20. Fuzzy controller for better tennis ball robot | Nguyen | Journal of ...

    African Journals Online (AJOL)

    This paper aims at designing a tennis ball robot as a training facility for tennis players. The robot is built with fuzzy controller which provides proper techniques for the players to gain practical experience as well as technical skills; thus, it can effectively serve the community and train athletes in the high-performance sport.