WorldWideScience

Sample records for ball and socket joints

  1. The adult ball-and-socket ankle joint: surgical management of late ankle and subtalar arthritis.

    Science.gov (United States)

    Lewis, John S; DeOrio, James K

    2015-04-01

    We review the surgical management of 4 adult patients with ball-and-socket ankle deformity who developed end-stage subtalar and/or ankle joint arthritis. We retrospectively reviewed a series of 4 adult patients with ball-and-socket ankle configurations who underwent surgical treatment for either end-stage tibiotalar or subtalar arthritis, with either subtalar arthrodesis or total ankle replacement (TAR). Clinical outcome, including subjective pain assessment, limitation of activities, and difficulty with shoe wear, were assessed at follow-up. A total of 5 ankles in 4 patients were identified that met the inclusion criteria. There were 3 subtalar arthrodeses in 2 patients and 2 primary TARs in 2 patients. At an average follow-up of 30.5 (range = 17 to 59) months, there were no failures, although 1 patient who underwent TAR was considered an impending failure with aseptic component loosening. Of the 4 patients, 3 resumed normal activity with minimal pain and were very pleased with their overall outcome. Standard surgical interventions for ankle and subtalar arthritis, such as total ankle arthroplasty and subtalar arthrodesis, can be successfully performed in patients with ball-and-socket ankles; clinical outcome and survivorship, however, may be inferior to that in patients with normal ankle configurations. Therapeutic, Level IV: Case Series. © 2014 The Author(s).

  2. Ankle and subtalar synovitis in a ball-and-socket ankle joint causing posterolateral painful coarse crepitus: a case report.

    Science.gov (United States)

    Fan, Ka Yuk; Lui, Tun Hing

    2014-01-01

    A 17-year-old girl with bilateral ball-and-socket ankles reported left medial heel pain. Her left heel had gone into a varus position on tiptoeing, and a painful clunk had occurred when returning to normal standing. The clunk persisted after physiotherapy and treatment with an orthosis. Subtalar arthroscopy and peroneal tendoscopy showed mild diffuse synovitis of the ankle joint, especially over the posterior capsule, and a patch of inflamed and fibrotic synovium at the posterolateral corner of the subtalar joint. The clunk subsided immediately after arthroscopic synovectomy and had not recurred during 5 years of follow-up. We found no other reported cases of ankle and subtalar synovitis occurring in patients with a ball-and-socket ankle joint. Copyright © 2014 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

  3. Photovoltaic Universal Joints: Ball-and-Socket Interfaces in Molecular Photovoltaic Cells

    Energy Technology Data Exchange (ETDEWEB)

    Tremblay, Noah J.; Gorodetsky, Alon A.; Cox, Marshall P.; Schiros, Theanne; Kim, Bumjung; Steiner, Rachel; Bullard, Zachary; Sattler, Aaron; So, Woo-Young; Itoh, Yoshimitsu; Toney, Michael F.; Ogasawara, Hirohito; Ramirez, Arthur P.; Kymissis, Ioannis; Steigerwald, Michael L.; Nuckolls, Colin

    2010-02-15

    A new approach toward higher efficiency organic photovoltaic devices (OPVs) is described. Complementarity in shape between the donor (contorted hexabenzocoronene, see picture) and acceptor (buckminsterfullerene) molecules results in OPVs that perform surprisingly well. This exploitation of host-guest chemistry at the organic/organic interface demonstrates a new direction for OPV device design.

  4. Ball-and-socket tectonic rotation during the 2013 Mw7.7 Balochistan earthquake

    Science.gov (United States)

    Barnhart, William D.; Hayes, Gavin P.; Briggs, Richard W.; Gold, Ryan D.; Bilham, R.

    2014-01-01

    The September 2013 Mw7.7 Balochistan earthquake ruptured a ∼200-km-long segment of the curved Hoshab fault in southern Pakistan with 10±0.2 m of peak sinistral and ∼1.7±0.8 m of dip slip. This rupture is unusual because the fault dips 60±15° towards the focus of a small circle centered in northwest Pakistan, and, despite a 30° increase in obliquity along strike, the ratios of strike and dip slip remain relatively uniform. Surface displacements and geodetic and teleseismic source inversions quantify a bilateral rupture that propagated rapidly at shallow depths from a transtensional jog near the northern end of the rupture. Static friction prior to rupture was unusually weak (μball-and-socket joint – counter-clockwise in response to India's penetration into the Eurasian plate. This rotation accounts for complexity in the Chaman fault system and, in principle, reduces seismic potential near Karachi; nonetheless, these findings highlight deficiencies in strong ground motion equations and tectonic models that invoke Anderson–Byerlee faulting predictions.

  5. Strength evaluation of socket joints

    Science.gov (United States)

    Rash, Larry C.

    1994-01-01

    This report documents the development of a set of equations that can be used to provide a relatively simple solution for identifying the strength of socket joints and for most cases avoid the need of more lengthy analyses. The analytical approach was verified by comparison of the contact load distributions to results obtained from a finite element analysis. The contacting surfaces for the specific joint in this analysis are in the shape of frustrums of a cone and are representative of the tapered surfaces in the socket-type joints used to join segments of model support systems for wind tunnels. The results are in the form of equations that can be used to determine the contact loads and stresses in the joint from the given geometry and externally applied loads. Equations were determined to define the bending moments and stresses along the length of the joints based on strength and materials principles. The results have also been programmed for a personal computer and a copy of the program is included.

  6. Study on torsional fretting wear behavior of a ball-on-socket contact configuration simulating an artificial cervical disk

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Song [State Key Laboratory of Tribology, Tsinghua University, Beijing 100084 (China); Department of Mechanical Engineering, Tsinghua University, Beijing 100084 (China); Wang, Fei [School of Material Science and Engineering, China University of Mining and Technology, Xuzhou 221116 (China); Liao, Zhenhua [Department of Mechanical Engineering, Tsinghua University, Beijing 100084 (China); Biomechanics and Biotechnology Lab, Research Institute of Tsinghua University in Shenzhen, Shenzhen 518057 (China); Wang, Qingliang [School of Material Science and Engineering, China University of Mining and Technology, Xuzhou 221116 (China); Liu, Yuhong [State Key Laboratory of Tribology, Tsinghua University, Beijing 100084 (China); Department of Mechanical Engineering, Tsinghua University, Beijing 100084 (China); Liu, Weiqiang, E-mail: weiqliu@hotmail.com [Biomechanics and Biotechnology Lab, Research Institute of Tsinghua University in Shenzhen, Shenzhen 518057 (China); State Key Laboratory of Tribology, Tsinghua University, Beijing 100084 (China)

    2015-10-01

    A ball-on-socket contact configuration was designed to simulate an artificial cervical disk in structure. UHMWPE (ultra high molecular weight polyethylene) hot pressed by powders and Ti6Al4V alloy were selected as the material combination of ball and socket. The socket surface was coated by a ~ 500 nm C-DLC (carbon ion implantation-diamond like carbon) mixed layer to improve its surface nano hardness and wear resistance. The torsional fretting wear behavior of the ball-on-socket model was tested at different angular displacements under 25% bovine serum lubrication with an axial force of 100 N to obtain more realistic results with that in vivo. The fretting running regimes and wear damage characteristics as well as wear mechanisms for both ball and socket were studied based on 2D (two dimension) optical microscope, SEM (scanning electron microscope) and 3D (three dimension) profiles. With the increase of angular displacement amplitude from 1° to 7°, three types of T-θ (Torsional torque-angular displacement amplitude) curves (i.e., linear, elliptical and parallelogram loops) corresponding to running regimes of PSR (partial slip regime), MR (mixed regime) and SR (slip regime) were observed and analyzed. Both the central region and the edge zone of the ball and socket were damaged. The worn surfaces were characterized by wear scratches and wear debris. In addition, more severe wear damage and more wear debris appeared on the central region of the socket at higher angular displacement amplitude. The dominant damage mechanism was a mix of surface scratch, adhesive wear and abrasive wear for the UHMWPE ball while that for the coated socket was abrasive wear by PE particles and some polishing and rolling process on the raised overgrown DLC grains. The frictional kinetic behavior, wear type, damage region and damage mechanism for the ball-on-socket model revealed significant differences with those of a ball-on-flat contact while showing better consistency with that of in

  7. Study on torsional fretting wear behavior of a ball-on-socket contact configuration simulating an artificial cervical disk

    International Nuclear Information System (INIS)

    Wang, Song; Wang, Fei; Liao, Zhenhua; Wang, Qingliang; Liu, Yuhong; Liu, Weiqiang

    2015-01-01

    A ball-on-socket contact configuration was designed to simulate an artificial cervical disk in structure. UHMWPE (ultra high molecular weight polyethylene) hot pressed by powders and Ti6Al4V alloy were selected as the material combination of ball and socket. The socket surface was coated by a ~ 500 nm C-DLC (carbon ion implantation-diamond like carbon) mixed layer to improve its surface nano hardness and wear resistance. The torsional fretting wear behavior of the ball-on-socket model was tested at different angular displacements under 25% bovine serum lubrication with an axial force of 100 N to obtain more realistic results with that in vivo. The fretting running regimes and wear damage characteristics as well as wear mechanisms for both ball and socket were studied based on 2D (two dimension) optical microscope, SEM (scanning electron microscope) and 3D (three dimension) profiles. With the increase of angular displacement amplitude from 1° to 7°, three types of T-θ (Torsional torque-angular displacement amplitude) curves (i.e., linear, elliptical and parallelogram loops) corresponding to running regimes of PSR (partial slip regime), MR (mixed regime) and SR (slip regime) were observed and analyzed. Both the central region and the edge zone of the ball and socket were damaged. The worn surfaces were characterized by wear scratches and wear debris. In addition, more severe wear damage and more wear debris appeared on the central region of the socket at higher angular displacement amplitude. The dominant damage mechanism was a mix of surface scratch, adhesive wear and abrasive wear for the UHMWPE ball while that for the coated socket was abrasive wear by PE particles and some polishing and rolling process on the raised overgrown DLC grains. The frictional kinetic behavior, wear type, damage region and damage mechanism for the ball-on-socket model revealed significant differences with those of a ball-on-flat contact while showing better consistency with that of in

  8. Effects of bushings characteristics on suspension ball joint travels

    Science.gov (United States)

    Yang, Xiaobo

    2011-02-01

    In this paper, a short-long arm type front suspension is represented using multi-body dynamics model established with ADAMS®, where the suspension bushings modelled as linear and nonlinear elements, respectively, are integrated with a flexible cradle and other suspension components. A ball joint travel, defined as the angular displacement between the two parts connected with the ball joint, is calculated, where the measured wheel loads and spindle accelerations from a proving ground severe durability test schedule serve as the input data. The ball joints considered in this study include lower ball joints, upper ball joints, outer tierod ball joints, and inner tierod ball joints. The results clearly illustrate that the bushing stiffness and nonlinearity are important for an accurate prediction of ball joint travels and the ball joint travel sensitivities to considered design variables are important for engineers to understand and ensure reliable designs of ball joints.

  9. Study on torsional fretting wear behavior of a ball-on-socket contact configuration simulating an artificial cervical disk.

    Science.gov (United States)

    Wang, Song; Wang, Fei; Liao, Zhenhua; Wang, Qingliang; Liu, Yuhong; Liu, Weiqiang

    2015-10-01

    A ball-on-socket contact configuration was designed to simulate an artificial cervical disk in structure. UHMWPE (ultra high molecular weight polyethylene) hot pressed by powders and Ti6Al4V alloy were selected as the material combination of ball and socket. The socket surface was coated by a ~500 nm C-DLC (carbon ion implantation-diamond like carbon) mixed layer to improve its surface nano hardness and wear resistance. The torsional fretting wear behavior of the ball-on-socket model was tested at different angular displacements under 25% bovine serum lubrication with an axial force of 100 N to obtain more realistic results with that in vivo. The fretting running regimes and wear damage characteristics as well as wear mechanisms for both ball and socket were studied based on 2D (two dimension) optical microscope, SEM (scanning electron microscope) and 3D (three dimension) profiles. With the increase of angular displacement amplitude from 1° to 7°, three types of T-θ (Torsional torque-angular displacement amplitude) curves (i.e., linear, elliptical and parallelogram loops) corresponding to running regimes of PSR (partial slip regime), MR (mixed regime) and SR (slip regime) were observed and analyzed. Both the central region and the edge zone of the ball and socket were damaged. The worn surfaces were characterized by wear scratches and wear debris. In addition, more severe wear damage and more wear debris appeared on the central region of the socket at higher angular displacement amplitude. The dominant damage mechanism was a mix of surface scratch, adhesive wear and abrasive wear for the UHMWPE ball while that for the coated socket was abrasive wear by PE particles and some polishing and rolling process on the raised overgrown DLC grains. The frictional kinetic behavior, wear type, damage region and damage mechanism for the ball-on-socket model revealed significant differences with those of a ball-on-flat contact while showing better consistency with that of in

  10. Joint prosthesis and method of bone fixation

    NARCIS (Netherlands)

    Oosterom, R.; Van der Pijl, A.J.; Bersee, H.E.N.; Van der Helm, F.C.; Herder, J.L.

    2006-01-01

    The invention relates to a joint prosthesis (10), for example, a knee joint or shoulder joint prosthesis comprising a first, socket-holding prosthesis part (11) for attachment to a first bone (12) and a second, ball-holding prosthesis part (13) for attachment to a second bone (14) that intermates

  11. Finite element model predicts the biomechanical performance of cervical disc replacement and fusion hybrid surgery with various geometry of ball-and-socket artificial disc.

    Science.gov (United States)

    Li, Yang; Fogel, Guy R; Liao, Zhenhua; Liu, Weiqiang

    2017-08-01

    Few finite element studies have investigated changes in cervical biomechanics with various prosthesis design parameters using hybrid surgery (HS), and none have investigated those combined different HS strategies. The aim of our study was to investigate the effect of ball-and-socket prosthesis geometry on the biomechanical performance of the cervical spine combined with two HS constructs. Two HS strategies were conducted: (1) ACDF at C4-C5 and anterior cervical disc replacement (ACDR) at C5-C6 (ACDF/ACDR), and (2) ACDR/ACDF. Three different prostheses were used for each HS strategy: prosthesis with the core located at the center of the inferior endplate with a radius of 5 mm (BS-5) or 6 mm (BS-6), or with a 5 mm radius core located 1 mm posterior to the center of the inferior endplate (PBS-5). Flexion and extension motions were simulated under displacement control. The flexion motions in supra- and infra-adjacent levels increased in all cases. The corresponding extension motions increased with all prostheses in ACDR/ACDF group. The stiffness in flexion and extension increased with all HS models, except for the extension stiffness with ACDF/ACDR. The facet stresses between the index and infra-adjacent level in ACDR/ACDF were significantly greater than those in the intact model . The stresses on the BS-5 UHMWPE core were greater than the yield stress. The core radii and position did not significantly affect the moments, ROM, and facet stress in extension. However, the moments and ROM in flexion were easily affected by the position. The results implied that the large core radii and posterior core position in ACDR designs may reduce the risk of subsidence and wear in the long term as they showed relative low stress . The ACDF/ACDR surgery at C4-C6 level may be an optimal treatment for avoiding accelerating the degeneration of adjacent segments.

  12. Self-aligning exoskeleton hip joint: Kinematic design with five revolute, three prismatic and one ball joint.

    Science.gov (United States)

    Beil, Jonas; Marquardt, Charlotte; Asfour, Tamim

    2017-07-01

    Kinematic compatibility is of paramount importance in wearable robotic and exoskeleton design. Misalignments between exoskeletons and anatomical joints of the human body result in interaction forces which make wearing the exoskeleton uncomfortable and even dangerous for the human. In this paper we present a kinematically compatible design of an exoskeleton hip to reduce kinematic incompatibilities, so called macro- and micro-misalignments, between the human's and exoskeleton's joint axes, which are caused by inter-subject variability and articulation. The resulting design consists of five revolute, three prismatic and one ball joint. Design parameters such as range of motion and joint velocities are calculated based on the analysis of human motion data acquired by motion capture systems. We show that the resulting design is capable of self-aligning to the human hip joint in all three anatomical planes during operation and can be adapted along the dorsoventral and mediolateral axis prior to operation. Calculation of the forward kinematics and FEM-simulation considering kinematic and musculoskeletal constraints proved sufficient mobility and stiffness of the system regarding the range of motion, angular velocity and torque admissibility needed to provide 50 % assistance for an 80 kg person.

  13. Consequences of impact on arm (elbow and shoulder joints) caused by ball hitting, theoretical analysis

    Science.gov (United States)

    Negrea, Adina; Busuioceanu, Ioana Iuliana

    2018-02-01

    Present paper estimates the mechanics of the impact of a ball and a hand-arm, during the sports training using a classical model for the hand-arm system, avoiding the contribution of the coefficient of restitution. The results of this investigation are focused on the equations needed to find out theimpact reactions in elbow and shoulder joints, for different anthropometric data. Also, the computing of the position of mass centers and the moments of inertia for each constitutive part of hand-arm system is made.

  14. Ultrasonic defect detection method for socket welding joint

    International Nuclear Information System (INIS)

    Tominaga, Masaaki; Matsuo, Toshiyuki; Ueno, Akihiro; Watanabe, Kunimichi; Kawamata, Kunio.

    1995-01-01

    The present invention provides a method of detecting defects over a wide range of a socket weld portion of various kinds of pipelines used, for example, in a nuclear power plant. Namely, an inclined probe is disposed to a jig for detecting defects by ultrasonic waves. This is rotated at least by one turn along the peripheral surface of the material to be detected such as weld tube joints. Defects of weld portion of the material can be detected automatically by using ultrasonic waves during the rotation. The inclined probe for detecting defects by ultrasonic waves comprises a transmission portion having a planar transmittance oscillator disposed to a wedge on the transmission side and a receiving portion comprising a planar receiving oscillator disposed to a wedge on the receiving side. With such a constitution, ultrasonic waves are emitted from the transmission portion to the defect detection portion in the welded portion. If a defect is present, defective echo is reflected to the receiving portion disposed ahead of the probe. Since the defective echo changes depending on the height of the detective portion, the estimation of the height of the defect can be facilitated. (I.S.)

  15. Analysis on Sealing Reliability of Bolted Joint Ball Head Component of Satellite Propulsion System

    Science.gov (United States)

    Guo, Tao; Fan, Yougao; Gao, Feng; Gu, Shixin; Wang, Wei

    2018-01-01

    Propulsion system is one of the important subsystems of satellite, and its performance directly affects the service life, attitude control and reliability of the satellite. The Paper analyzes the sealing principle of bolted joint ball head component of satellite propulsion system and discuss from the compatibility of hydrazine anhydrous and bolted joint ball head component, influence of ground environment on the sealing performance of bolted joint ball heads, and material failure caused by environment, showing that the sealing reliability of bolted joint ball head component is good and the influence of above three aspects on sealing of bolted joint ball head component can be ignored.

  16. The effect of ball impact location on racket and forearm joint angle changes for one-handed tennis backhand groundstrokes.

    Science.gov (United States)

    King, Mark; Hau, Agnes; Blenkinsop, Glen

    2017-07-01

    Recreational tennis players tend to have higher incidence of tennis elbow, and this has been hypothesised to be related to one-handed backhand technique and off-centre ball impacts on the racket face. This study aimed to investigate for a range of participants the effect of off-longitudinal axis and off-lateral axis ball-racket impact locations on racket and forearm joint angle changes immediately following impact in one-handed tennis backhand groundstrokes. Three-dimensional racket and wrist angular kinematic data were recorded for 14 university tennis players each performing 30 "flat" one-handed backhand groundstrokes. Off-longitudinal axis ball-racket impact locations explained over 70% of the variation in racket rotation about the longitudinal axis and wrist flexion/extension angles during the 30 ms immediately following impact. Off-lateral axis ball-racket impact locations had a less clear cut influence on racket and forearm rotations. Specifically off-longitudinal impacts below the longitudinal axis forced the wrist into flexion for all participants with there being between 11° and 32° of forced wrist flexion for an off-longitudinal axis impact that was 1 ball diameter away from the midline. This study has confirmed that off-longitudinal impacts below the longitudinal axis contribute to forced wrist flexion and eccentric stretch of the wrist extensors and there can be large differences in the amount of forced wrist flexion from individual to individual and between strokes with different impact locations.

  17. Pain and discomfort in the anophthalmic socket

    DEFF Research Database (Denmark)

    Bohman, Elin; Roed Rasmussen, Marie Louise; Kopp, Eva Dafgård

    2014-01-01

    PURPOSE OF REVIEW: The aim of this review is to summarize causes of pain and discomfort in the anophthalmic socket and to aid the clinician in evaluating anophthalmic patients. RECENT FINDINGS: Causes of pain and discomfort can be categorized into dysfunctional orbit/anophthalmic socket, phantom ...... pain and discomfort for a variety of reasons. The treating physician needs to recognize this as treatment options are distinctly different....

  18. Mandibular Overdentures Retained by Two Implants : 10-Year Results from a Crossover Clinical Trial Comparing Ball-Socket and Bar-Clip Attachments

    NARCIS (Netherlands)

    Cune, Marco; Burgers, Mark; van Kampen, Frits; de Putter, Cornelis; van der Bilt, Andries

    2010-01-01

    Purpose: The aim of this study was to evaluate patient satisfaction and clinical and prosthetic outcomes of two-implant mandibular overdenture treatment with different attachment types after 10 years of function. Materials and Methods: In a crossover clinical trial, 18 edentulous subjects with

  19. Modeling and remodeling of human extraction sockets.

    Science.gov (United States)

    Trombelli, Leonardo; Farina, Roberto; Marzola, Andrea; Bozzi, Leopoldo; Liljenberg, Birgitta; Lindhe, Jan

    2008-07-01

    The available studies on extraction wound repair in humans are affected by significant limitations and have failed to evaluate tissue alterations occurring in all compartments of the hard tissue defect. To monitor during a 6-month period the healing of human extraction sockets and include a semi-quantitative analysis of tissues and cell populations involved in various stages of the processes of modeling/remodeling. Twenty-seven biopsies, representative of the early (2-4 weeks, n=10), intermediate (6-8 weeks, n=6), and late phase (12-24 weeks, n=11) of healing, were collected and analysed. Granulation tissue that was present in comparatively large amounts in the early healing phase of socket healing, was in the interval between the early and intermediate observation phase replaced with provisional matrix and woven bone. The density of vascular structures and macrophages slowly decreased from 2 to 4 weeks over time. The presence of osteoblasts peaked at 6-8 weeks and remained almost stable thereafter; a small number of osteoclasts were present in a few specimens at each observation interval. The present findings demonstrated that great variability exists in man with respect to hard tissue formation within extraction sockets. Thus, whereas a provisional connective tissue consistently forms within the first weeks of healing, the interval during which mineralized bone is laid down is much less predictable.

  20. Happy Balls, Unhappy Balls, and Newton's Cradle

    Science.gov (United States)

    Kagan, David

    2010-01-01

    The intricacies of Newton's Cradle are well covered in the literature going as far back as the time of Newton! These discussions generally center on the highly elastic collisions of metal spheres. Thanks to the invention of happy and unhappy balls, you can build and study the interaction of less elastic systems (see Fig. 1).

  1. Intercellular coupling mediated by potassium accumulation in peg-and-socket junctions

    DEFF Research Database (Denmark)

    Vigmond, Edward J.; Bardakjian, Berj L.; Thuneberg, Lars

    2000-01-01

    Physiology, peg-and-socket junctions, smooth muscle, boundary element method, coupling, morphology......Physiology, peg-and-socket junctions, smooth muscle, boundary element method, coupling, morphology...

  2. FINITE ELEMENT ANALYSIS ON THE EFFECT OF SOLDER JOINT GEOMETRY FOR THE RELIABILITY OF BALL GRID ARRAY ASSEMBLY WITH FLEXIBLE AND RIGID PCBS

    Directory of Open Access Journals (Sweden)

    CHUN-SEAN LAU

    2014-02-01

    Full Text Available In the present study, three-dimensional (3D finite element simulation on 132 PIN fleXBGATM package was performed to predict the effect of solder joint geometry on the reliability of Ball Grid Array (BGA solder joints on flexible and rigid PCBs subjected to thermo-cyclic loading. The commercial FEA tool ABAQUS Version 6.9 was used for the simulations of various shapes of solder joints such as barrel, column and hourglass. Apart from a global modeling, the submodeling analysis technique (local modeling was also used on the critically affected solder joints, in order to enhance the computation efficiency. The accumulated creep strain and strain energy density were observed for each case, and optimum geometries were obtained. The model was validated with the published experimental data with the minimum percentage error of 3%. It was observed that the hourglass solder joint geometry was very crucial on the reliability of BGA solder joints, and for a given PCB, the optimal choice of hourglass solder joint geometry depended on its rigidity.

  3. Middle finger and ball movements around ball release during baseball fastball pitching.

    Science.gov (United States)

    Matsuo, Tomoyuki; Jinji, Tsutomu; Hirayama, Daisaku; Nasu, Daiki; Ozaki, Hiroki; Kumagawa, Daisuke

    2017-02-28

    The objectives of this study were to investigate middle finger movements and dynamics of ball movements around the instant of ball release during baseball pitching. Baseball pitching from an indoor mound among 14 semi-professional pitchers was captured using a motion capture system with 16 high-speed cameras (1,000 Hz). Kinematics of middle finger joints, ball rotation, and force applied to the ball were calculated. The proximal and distal interphalangeal joints continued to extend until the instant of ball release, then abruptly flexed. The abrupt flexion lasted for only several milliseconds, followed by a short extension phase. The finger made a quick double cycle of extension-flexion movement, suggesting that it attained high stiffness resulting from co-contraction. The ball began to roll up to the tip of the finger 8 ± 1 ms before ball release owing to the start of extension or the increased angular velocity of extension for the proximal interphalangeal joint. A mean force of 195 ± 27 N was applied in the proximal direction of the hand at the same time as the beginning of ball rolling, and a mean force of 109 ± 22 N was applied to the throwing direction just before ball release.

  4. Shallow Inferior Conjunctival Fornix in Contracted Socket and Anophthalmic Socket Syndrome: A Novel Technique to Deepen the Fornix Using Fascia Lata Strips

    Directory of Open Access Journals (Sweden)

    Mohamed F. K. Ibrahiem

    2016-01-01

    Full Text Available Purpose. To evaluate a new surgical technique using fascia lata to deepen the shallow inferior conjunctival fornix in contracted socket and anophthalmic socket syndrome. Methods. A prospective controlled study in which 24 sockets of 24 patients who were unable to wear and retain their ocular prosthesis due to shallow inferior fornix were enrolled and categorized into anophthalmic socket syndromes (9 patients and contracted sockets (15 patients. Another 24 patients who underwent evisceration or enucleation with healthy sockets and can wear and retain their prosthesis comfortably were chosen as a control group. Deepening of the fornix was performed using fascia lata strips under general anesthesia. Central depth of the inferior fornix was measured preoperatively and postoperatively. Results. A statistically significant improvement of the postoperative central inferior fornix depth was reported which was marked in anophthalmic subgroup. 100% of anophthalmic sockets and 93.3% of contracted sockets achieved satisfactory results during the follow-up period with no postoperative lower eyelid malposition or obvious skin scar. Conclusion. Fascia lata technique is a new alternative and effective procedure to deepen the shallow inferior fornix that can be used in moderate to severe contracted sockets or anophthalmic socket syndrome with minimal lower eyelid or socket complications.

  5. An open randomized controlled clinical trial to evaluate ridge preservation and repair using SocketKAP(™) and SocketKAGE(™) : part 2 - three-dimensional alveolar bone volumetric analysis of CBCT imaging.

    Science.gov (United States)

    Abdelhamid, Alaa; Omran, Mostafa; Bakhshalian, Neema; Tarnow, Dennis; Zadeh, Homayoun H

    2016-06-01

    The aims of this study were (i) to evaluate the efficacy of ridge preservation and repair procedures involving the application of SocketKAP(™) and SocketKAGE(™) devices following tooth removal and (ii) to evaluate alveolar bone volumetric changes at 6 months post-extraction in intact sockets or those with facial wall dehiscence defects using 3-dimensional pre- and postoperative CBCT data. Thirty-six patients required 61 teeth extracted. Five cohorts were established: Group A: Intact Socket Negative Control Group B: Intact Socket + SocketKAP(™) Group C: Intact Socket Filled with Anorganic Bovine Bone Mineral (ABBM) + SocketKAP(™) Group D: Facial Dehiscence Socket Negative Control Group E: Facial Dehiscence Socket Filled with ABBM + SocketKAP(™) + SocketKAGE(™) . Preoperative CBCT scans were obtained followed by digital subtraction of the test teeth. At 6 months post-extraction, another CBCT scan was obtained. The pre- and postoperative scans were then superimposed, allowing highly accurate quantitative determination of the 3D volumetric alveolar bone volume changes from baseline through 6 months. Significant volumetric bone loss occurred in all sockets, localized mainly in the 0-3 mm zone apical to the ridge crest. For intact sockets, SocketKAP(™) + ABBM treatment led to a statistically significant greater percentage of remaining mineralized tissue volume when compared to negative control group. A significant difference favoring SocketKAP(™) + SocketKAGE(™) + ABBM treatment was observed for sockets with facial dehiscence defects compared to the negative control group. SocketKAP(™) , with ABBM, appears effective in limiting post-extraction volumetric bone loss in intact sockets, while SocketKAP(™) + SocketKAGE + ABBM appears effective in limiting post-extraction bone loss in sockets with dehiscence defects. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  6. Progress Toward Optimizing Prosthetic Socket Fit and Suspension Using Elevated Vacuum to Promote Residual Limb Health

    OpenAIRE

    Wernke, Matthew M.; Schroeder, Ryan M.; Haynes, Michael L.; Nolt, Lonnie L.; Albury, Alexander W.; Colvin, James M.

    2017-01-01

    Objective: Prosthetic sockets are custom made for each amputee, yet there are no quantitative tools to determine the appropriateness of socket fit. Ensuring a proper socket fit can have significant effects on the health of residual limb soft tissues and overall function and acceptance of the prosthetic limb. Previous work found that elevated vacuum pressure data can detect movement between the residual limb and the prosthetic socket; however, the correlation between the two was specific to ea...

  7. Progress Toward Optimizing Prosthetic Socket Fit and Suspension Using Elevated Vacuum to Promote Residual Limb Health.

    Science.gov (United States)

    Wernke, Matthew M; Schroeder, Ryan M; Haynes, Michael L; Nolt, Lonnie L; Albury, Alexander W; Colvin, James M

    2017-07-01

    Objective: Prosthetic sockets are custom made for each amputee, yet there are no quantitative tools to determine the appropriateness of socket fit. Ensuring a proper socket fit can have significant effects on the health of residual limb soft tissues and overall function and acceptance of the prosthetic limb. Previous work found that elevated vacuum pressure data can detect movement between the residual limb and the prosthetic socket; however, the correlation between the two was specific to each user. The overall objective of this work is to determine the relationship between elevated vacuum pressure deviations and prosthetic socket fit. Approach: A tension compression machine was used to apply repeated controlled forces onto a residual limb model with sockets of different internal volume. Results: The vacuum pressure-displacement relationship was dependent on socket fit. The vacuum pressure data were sensitive enough to detect differences of 1.5% global volume and can likely detect differences even smaller. Limb motion was reduced as surface area of contact between the limb model and socket was maximized. Innovation: The results suggest that elevated vacuum pressure data provide information to quantify socket fit. Conclusions: This study provides evidence that the use of elevated vacuum pressure data may provide a method for prosthetists to quantify and monitor socket fit. Future studies should investigate the relationship between socket fit, limb motion, and limb health to define optimal socket fit parameters.

  8. Ridge preservation comparing socket allograft alone to socket allograft plus facial overlay xenograft: a clinical and histologic study in humans.

    Science.gov (United States)

    Poulias, Evmenios; Greenwell, Henry; Hill, Margaret; Morton, Dean; Vidal, Ricardo; Shumway, Brian; Peterson, Thomas L

    2013-11-01

    Previous studies of ridge preservation showed a loss of ≈18% or 1.5 mm of crestal ridge width in spite of treatment. The primary aim of this randomized, controlled, masked clinical trial is to compare a socket graft to the same treatment plus a buccal overlay graft, both with a polylactide membrane, to determine if loss of ridge width can be prevented by use of an overlay graft. Twelve patients who served as positive controls received an intrasocket mineralized cancellous allograft (socket group), and 12 patients received the same socket graft procedure plus buccal overlay cancellous xenograft (overlay group). Horizontal ridge dimensions were measured with a digital caliper, and vertical ridge changes were measured from a stent. Before implant placement, at 4 months, a trephine core was obtained for histologic analysis. The mean horizontal ridge width at the crest for the socket group decreased from 8.7 ± 1.0 to 7.1 ± 1.5 mm for a mean loss of 1.6 ± 0.8 mm (P overlay group decreased from 8.4 ± 1.4 to 8.1 ± 1.4 mm for a mean loss of 0.3 ± 0.9 mm (P >0.05). The overlay group was significantly different from the socket group (P overlay group had 40% ± 16% (P >0.05). The overlay treatment significantly prevented loss of ridge width and preserved or augmented the buccal contour. The socket and overlay groups healed with a high percentage of vital bone.

  9. Discharge and infection in retinoblastoma post-enucleation sockets

    Directory of Open Access Journals (Sweden)

    Mourits DL

    2017-03-01

    Full Text Available Daphne L Mourits,1 Dyonne T Hartong,1 Andries E Budding,2 Machteld I Bosscha,1 H Stevie Tan,1 Annette C Moll1 1Department of Ophthalmology, VU University Medical Center, 2Department of Microbiology, Academic Medical Center, Amsterdam, the Netherlands Purpose: To investigate the causes and treatment options for socket discharge and infection in patients enucleated for retinoblastoma (Rb. Methods: A questionnaire was filled out by (parents of ocular prosthesis-wearing patients with a history of enucleation as treatment for Rb. We collected data on patients’ characteristics, cleaning habits of the prosthesis, frequency of socket irritation, discharge, and infection, and use of antibiotics. With ordinal logistic regression analysis, factors related to the outcome parameters (frequency of irritation, mucoid and purulent discharge were identified. In a subset of young asymptomatic and symptomatic patients, a swab culture of the socket was performed to determine the presence of microorganisms. Results: A total of 186 patients or their parents (mean age of the patients: 17.3 years, ranging from 0.8 to 88.3 years filled out the questionnaire. Irritation, mucoid discharge, and purulent discharge were frequently (once a month or more often experienced in 75 (39.5%, 127 (66.8%, and 15 (13.2% sockets, respectively. Younger age was associated with a higher frequency of mucoid and purulent discharge. Radiation therapy, chemotherapy, gender, age at surgery, cleaning frequency, and nocturnal wear were not associated with the outcome parameters. In a subgroup of 26 patients, the sockets were swabbed and cultured. All symptomatic patients had a positive bacterial culture versus 15% (2/13 of the asymptomatic patients (P<0.001. Common cold was correlated with both symptoms and presence of bacteria. Haemophilus influenzae and Staphylococcus aureus were the species most frequently cultured. Conclusion: Ocular prosthesis-wearing patients often experienced mucoid

  10. Immediate implant placement into fresh extraction sockets versus delayed implants into healed sockets: A systematic review and meta-analysis.

    Science.gov (United States)

    Mello, C C; Lemos, C A A; Verri, F R; Dos Santos, D M; Goiato, M C; Pellizzer, E P

    2017-09-01

    The aim of this systematic review and meta-analysis was to compare the survival rate of the implants and the peri-implant tissue changes associated with implants inserted in fresh extraction sockets and those inserted in healed sockets. This review has been registered at PROSPERO under the number CRD42016043309. A systematic search was conducted by two reviewers independently in the databases PubMed/MEDLINE, Embase, and the Cochrane Library using different search terms; articles published until November 2016 were searched for. The searches identified 30 eligible studies. A total of 3,049 implants were installed in a total of 1,435 patients with a mean age of 46.68 years and a minimum of 6 months of follow-up. The survival rate of delayed implants (98.38%) was significantly greater than immediate implants (95.21%) (p=.001). For the marginal bone loss (p=.32), implant stability quotients values (p=.44), and pocket probing depth (p=.94) there was no significant difference between the analysed groups. The immediate implants placed in fresh sockets should be performed with caution because of the significantly lower survival rates than delayed implants inserted in healed sockets. Copyright © 2017 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

  11. Review of the Socket Design and Interface Pressure Measurement for Transtibial Prosthesis

    Directory of Open Access Journals (Sweden)

    Gh. Pirouzi

    2014-01-01

    Full Text Available Socket is an important part of every prosthetic limb as an interface between the residual limb and prosthetic components. Biomechanics of socket-residual limb interface, especially the pressure and force distribution, have effect on patient satisfaction and function. This paper aimed to review and evaluate studies conducted in the last decades on the design of socket, in-socket interface pressure measurement, and socket biomechanics. Literature was searched to find related keywords with transtibial amputation, socket-residual limb interface, socket measurement, socket design, modeling, computational modeling, and suspension system. In accordance with the selection criteria, 19 articles were selected for further analysis. It was revealed that pressure and stress have been studied in the last decaeds, but quantitative evaluations remain inapplicable in clinical settings. This study also illustrates prevailing systems, which may facilitate improvements in socket design for improved quality of life for individuals ambulating with transtibial prosthesis. It is hoped that the review will better facilitate the understanding and determine the clinical relevance of quantitative evaluations.

  12. Prosthetic sockets stabilized by alternating areas of tissue compression and release.

    Science.gov (United States)

    Alley, Randall D; Williams, T Walley; Albuquerque, Matthew J; Altobelli, David E

    2011-01-01

    A prosthetist makes a conventional socket by wrapping plaster bandage around the residual limb and using the resulting shell to create a positive model. After he or she modifies the plaster, it is used to create a laminated socket. Such sockets are almost perfect cylinders that encapsulate the limb. The bone is centered in soft, compressible tissue that must move aside before the bone can push against the socket to transmit force or torque to the prosthesis. In a compression/release stabilized (CRS) socket, three or more longitudinal depressions compress and displace tissue between the socket wall and the bone to reduce lost motion when the bone is moved with respect to the socket. Release areas between depressions are opened to accommodate displaced tissue. Without these openings provided, the CRS socket will not function as intended. Often, the release areas of compression are the struts of a carbon-fiber frame, and the regions between struts are left open. A frame with openings may be modified by the prosthetist adding a thin membrane fully surrounding the limb but allowing the membrane and underlying tissue to enter the release openings. The membrane may contain electrodes, and it may constitute a roll-on liner that helps suspend the prosthesis. We introduce three socket designs: transradial, transfemoral, and transhumeral.

  13. The structural analysis of socket inlays of the hip endoprosthesis

    Directory of Open Access Journals (Sweden)

    Robert Karpiński

    2016-12-01

    Full Text Available The paper presents results of the preliminary structural analysis of socket inlays model of the endoprosthesis of the hip joint. Basics of anatomy and biomechanical analysis of the hip joint were introduced. The prototype of socket inlay of the hip endoprosthesis was modeled using Solid Edge ST8 software. After determining physical properties of structural materials for socket inlays, the Finite Elements Analysis of the model was conducted using SolidWorks software under various load conditions. Finally the results of analysis were presented.

  14. Measurements of drag and lift on smooth balls in flight

    Science.gov (United States)

    Cross, Rod; Lindsey, Crawford

    2017-07-01

    Measurements are presented on the drag and lift coefficients for three relatively smooth balls launched in air and tracked with two cameras separated horizontally by 6.4 m. The ball spin was varied in order to investigate whether the Magnus force would increase or decrease when the ball spin was increased. For one ball, the Magnus force increased. For another ball, the Magnus force decreased almost to zero after reaching a maximum. For the third ball, the Magnus force was negative at low ball spins and positive at high ball spins. For one of the balls, the ball spin increased with time as it travelled through the air.

  15. Fluid Mechanics of Cricket and Tennis Balls

    Science.gov (United States)

    Mehta, Rabindra D.

    2009-11-01

    Aerodynamics plays a prominent role in defining the flight of a ball that is struck or thrown through the air in almost all ball sports. The main interest is in the fact that the ball can often deviate from its initial straight path, resulting in a curved, or sometimes an unpredictable, flight path. It is particularly fascinating that that not all the parameters that affect the flight of a ball are always under human influence. Lateral deflection in flight, commonly known as swing, swerve or curve, is well recognized in cricket and tennis. In tennis, the lateral deflection is produced by spinning the ball about an axis perpendicular to the line of flight, which gives rise to what is commonly known as the Magnus effect. It is now well recognized that the aerodynamics of sports balls are strongly dependent on the detailed development and behavior of the boundary layer on the ball's surface. A side force, which makes a ball curve through the air, can also be generated in the absence of the Magnus effect. In one of the cricket deliveries, the ball is released with the seam angled, which trips the laminar boundary layer into a turbulent state on that side. The turbulent boundary layer separates relatively late compared to the laminar layer on the other side, thereby creating a pressure difference and hence side force. The fluid mechanics of a cricket ball become very interesting at the higher Reynolds numbers and this will be discussed in detail. Of all the round sports balls, a tennis ball has the highest drag coefficient. This will be explained in terms of the contribution of the ``fuzz" drag and how that changes with Reynolds number and ball surface wear. It is particularly fascinating that, purely through historical accidents, small disturbances on the ball surface, such as the stitching on cricket balls and the felt cover on tennis balls are all about the right size to affect boundary layer transition and development in the Reynolds numbers of interest. The fluid

  16. Socket-shield and immediate implantation

    OpenAIRE

    Khalil, Joseph

    2016-01-01

    Introduction - After tooth extraction, the alveolar bone undergoes a remodeling process, wich leads to horizontal and vertical bone loss. These resorption processes complicate dental rehabilitation, particularly in connection with implants. Various methods of guided bone regeneration have been described to retain the original dimension of the bone after extraction. Most procedures use filler materials and membranes to support the buccal plate and soft tissue, to stabilize the c...

  17. Predicting the Drop Performance of Solder Joints by Evaluating the Elastic Strain Energy from High-Speed Ball Pull Tests

    Science.gov (United States)

    You, Taehoon; Kim, Yunsung; Kim, Jina; Lee, Jaehong; Jung, Byungwook; Moon, Jungtak; Choe, Heeman

    2009-03-01

    Despite being expensive and time consuming, board-level drop testing has been widely used to assess the drop or impact resistance of the solder joints in handheld microelectronic devices, such as cellphones and personal digital assistants (PDAs). In this study, a new test method, which is much simpler and quicker, is proposed. The method involves evaluating the elastic strain energy and relating it to the impact resistance of the solder joint by considering the Young’s modulus of the bulk solder and the fracture stress of the solder joint during a ball pull test at high strain rates. The results show that solder joints can be ranked in order of descending elastic strain energy as follows: Sn-37Pb, Sn-1Ag-0.5Cu, Sn-3Ag-0.5Cu, and Sn-4Ag-0.5Cu. This order is consistent with the actual drop performances of the samples.

  18. Case study: survey of patient satisfaction with prosthesis quality and design among below-knee prosthetic leg socket users.

    Science.gov (United States)

    Mohd Hawari, Nurhanisah; Jawaid, Mohammad; Md Tahir, Paridah; Azmeer, Raja Ahmad

    2017-11-01

    The aim of this case study was to explore patient satisfaction with the quality of prosthetic leg sockets intended for persons with lower limb amputations. A qualitative study based on in-depth interviews, preceded by a questionnaire session, was carried out with patients from the Rehabilitation Center and Hospital in Malaysia. Twelve out-patient and in-patient amputees with lower limb amputations, specifically below-knee amputations, were chosen randomly. The analysis of patients' narratives aimed to identify the functional and esthetic characteristics of currently used prosthetic leg sockets and any problems related to them. The obtained results indicated that out of the 12 participants, 41.7% and 25% were satisfied and somewhat satisfied with their current prosthetic sockets. Durability and comfort were rated by the participants as the most important characteristics of prosthetic sockets, with 83.3%. As regards the esthetic appearance of the socket, 66.7% of the respondents considered that the most important feature was the material from which the socket was fabricated. Thus, we conclude that current satisfaction levels with the quality of prosthetic sockets among amputees in Malaysia are suitable, prosthesis being preferred by many amputees. The results can be used to direct future research on cosmesis and functionality of prosthetic socket design. Implications for Rehabilitation Case study will help participants to get cost effective prosthetic leg socket. Develop prosthetic leg socket comfortable as comparative to existing one. Help Malaysian government to make policy to develop local prosthetic leg socket at affordable price.

  19. Titanium Socket for 120 mm Mortar Base

    National Research Council Canada - National Science Library

    2004-01-01

    .... However, its unique properties also make it difficult to machine productively. ARDEC was spending excessive time turning a profile of a ball socket into the component that supports the mortar tube...

  20. Broadband from the socket and privatization of power distribution networks

    International Nuclear Information System (INIS)

    Aalbers, R.; Baarsma, B.; Poort, J.

    2005-01-01

    Attention is paid to the consequences for the Dutch market of the recommendation of the European Commission to introduce Power Line Communication (PLC) in the EU member states. PLC makes it possible to access the internet via sockets [nl

  1. 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

  2. Inscribed Balls and Their Centers

    Science.gov (United States)

    Balashov, M. V.

    2017-12-01

    A ball of maximal radius inscribed in a convex closed bounded set with a nonempty interior is considered in the class of uniformly convex Banach spaces. It is shown that, under certain conditions, the centers of inscribed balls form a uniformly continuous (as a set function) set-valued mapping in the Hausdorff metric. In a finite-dimensional space of dimension n, the set of centers of balls inscribed in polyhedra with a fixed collection of normals satisfies the Lipschitz condition with respect to sets in the Hausdorff metric. A Lipschitz continuous single-valued selector of the set of centers of balls inscribed in such polyhedra can be found by solving n + 1 linear programming problems.

  3. Design model and recommendations of column-foundation connection through socket with rough interfaces

    Directory of Open Access Journals (Sweden)

    R. M. F. Canha

    Full Text Available The present work proposes design models and recommendations for column-foundation connection through socket with rough interfaces, including the shear key configuration, the socket and the precast column base. In the experimental investigations, the behavior of socket and column as a monolithic connection was verified. However, for this to occur, the shear key dimensions must be between the limits suggested by the study. Considering the total transfer of internal forces in the connections, the vertical reinforcement should be designed based on the bending theory. The proposed model for the design of the transverse horizontal reinforcement, considering monolithic behavior of the connection, was found to be in good agreement with the observed experimental results. With adjustments to this model for the socket, a new model for the design of precast column bases is proposed and compared with other model adapted for rough interfaces.

  4. An experimental and theoretical framework for manufacturing prosthetic sockets for transtibial amputees.

    Science.gov (United States)

    Faustini, Mario C; Neptune, Richard R; Crawford, Richard H; Rogers, William E; Bosker, Gordon

    2006-09-01

    Selective laser sintering (SLS) is a powerful manufacturing technology that does not require part-specific tooling or significant human intervention and provides the ability to easily generate parts with complex geometric designs. The present work focuses on developing a manufacturing framework using this technology to produce subject-specific transtibial amputee prosthetic sockets made of Duraform PA, which is a nylon-based material. The framework includes establishing an overall socket design (using the patellar-tendon bearing approach), performing a structural analysis using the finite element method (FEM) to ensure structural reliability during patient use, and validating the results by comparing the model output with experimental data. The validation included quantifying the failure conditions for the socket through a series of bending moment and compression tests. In the case study performed, the FEM results were within 3% of the experimental failure loads for the socket and were considered satisfactory.

  5. Design and Evaluation of a Socket Emulator for Publish/Subscribe Networks

    Science.gov (United States)

    Xylomenos, George; Cici, Blerim

    In order for a Future Internet architecture to be globally deployed, it must ensure that existing applications will continue to operate efficiently on top of it. As part of the Publish Subscribe Internet Routing Paradigm (PSIRP) project, we have explored various options for making endpoint centric applications based on the Sockets Application Programming Interface (API) compatible with the information centric PSIRP prototype implementation. We developed an emulator that mediates between the client/server socket calls and the publish/subscribe PSIRP calls, transforming the exchange of packets to distribution of publications. To assess the overhead of our emulator, we measure the execution time of a simple file transfer application in native socket mode, in emulated socket mode and in native publish/subscribe mode.

  6. Comparative analysis of use of porous orbital implant with mucus membrane graft and dermis fat graft as a primary procedure in reconstruction of severely contracted socket

    Directory of Open Access Journals (Sweden)

    Kasturi Bhattacharjee

    2014-01-01

    Full Text Available Purpose: The purpose of our study is to present a surgical technique of primary porous orbital ball implantation with overlying mucus membrane graft (MMG for reconstruction of severely contracted socket and to evaluate prosthesis retention and motility in comparison to dermis fat graft (DFG. Study Design: Prospective comparative study. Materials and Methods: A total of 24 patients of severe socket contracture (Grade 2-4 Krishna′s classification were subdivided into two groups, 12 patients in each group. In Group I, DFG have been used for reconstruction. In Group II, porous polyethylene implant with MMG has been used as a primary procedure for socket reconstruction. In Group I DFG was carried out in usual procedure. In case of Group II, vascularized scar tissues were separated 360° and were fashioned into four strips. A scleral capped porous polyethylene implant was placed in the intraconal space and four strips of scar tissue were secured to the scleral cap and extended part overlapped the implant to make a twofold barrier between the implant and MMG. Patients were followed-up as per prefixed proforma. Prosthesis motility and retention between the two groups were measured. Results: In Group I, four patients had recurrence of contracture with fall out of prosthesis. In Group II stable reconstruction was achieved in all the patients. In terms of prosthesis motility, maximum in Group I was 39.2% and Group II, was 59.3%. The difference in prosthesis retention (P = 0.001 and motility (P = 0.004 between the two groups was significant. Conclusion: Primary socket reconstruction with porous orbital implant and MMG for severe socket contracture is an effective method in terms of prosthesis motility and prosthesis retention.

  7. Alveolar socket preservation with demineralised bovine bone mineral and a collagen matrix.

    Science.gov (United States)

    Maiorana, Carlo; Poli, Pier Paolo; Deflorian, Matteo; Testori, Tiziano; Mandelli, Federico; Nagursky, Heiner; Vinci, Raffaele

    2017-08-01

    The aim of the present study was to evaluate the healing of post-extraction sockets following alveolar ridge preservation clinically, radiologically, and histologically. Overall, 7 extraction sockets in 7 patients were grafted with demineralised bovine bone mineral and covered with a porcine-derived non-crosslinked collagen matrix (CM). Soft tissue healing was clinically evaluated on the basis of a specific healing index. Horizontal and vertical ridge dimensional changes were assessed clinically and radiographically at baseline and 6 months after implant placement. For histological and histomorphometric analysis, bone biopsies were harvested from the augmented sites during implant surgery 6 months after the socket preservation procedure. Clinically, healing proceeded uneventfully in all the sockets. A trend towards reduced horizontal and vertical socket dimensions was observed from baseline to the final examination. The mean width and height of resorption were 1.21 mm ( P =0.005) and 0.46 mm ( P =0.004), respectively. Histologically, residual xenograft particles (31.97%±3.52%) were surrounded by either newly formed bone (16.02%±7.06%) or connective tissue (50.67%±8.42%) without fibrous encapsulation. The CM underwent a physiological substitution process in favour of well-vascularised collagen-rich connective tissue. Socket preservation using demineralised bovine bone mineral in combination with CM provided stable dimensional changes of the alveolar ridge associated with good re-epithelialisation of the soft tissues during a 6-month healing period.

  8. Clinical and histologic evaluations of healing in an extraction socket filled with platelet-rich fibrin

    Directory of Open Access Journals (Sweden)

    Jiing-Huei Zhao

    2011-06-01

    Full Text Available Platelet-rich fibrin (PRF is an immune and platelet concentrate that contains all constituents of a blood sample favorable to healing and immunity on a single fibrin membrane. However, limited information is currently available concerning the histologic healing of extraction sockets using PRF. This report presents the clinical and histologic characteristics of a patient who underwent a tooth extraction which was filled with PRF. The right mandibular second molar was removed from a 47-year-old male patient, and the socket was filled with PRF as the sole grafting material in preparation for placing an implant after wound healing. The extraction site was reentered surgically for implant placement. A cylindrical sample core of the newly formed tissue was collected from the socket for histological evaluation. During clinical healing, neither infectious episodes nor untoward clinical symptoms were seen. At the time of implant insertion, the socket was completely filled by a hard material, which on probing exhibited the consistency of bone. A histological exanimation of the core taken from the socket revealed new bone formation. There was also no evidence of inflammatory infiltrates. The clinical and histological findings suggest that filling a fresh extraction socket with PRF provides a viable therapeutic alternative for implant site preparation.

  9. Interface pressures during ambulation using suction and vacuum-assisted prosthetic sockets.

    Science.gov (United States)

    Beil, Tracy L; Street, Glenn M; Covey, Steven J

    2002-01-01

    Interface pressures were measured during ambulation with a normal total-surface weight-bearing suction socket and a vacuum-assisted socket. The vacuum-assisted socket has been shown to eliminate daily volume loss. Urethane liners were instrumented with five force-sensing resistors to measure positive pressures and one air pressure sensor at the distal end of the liner to document negative pressures. Nine unilateral transtibial amputees participated in the study. The vacuum-assisted socket created significantly lower positive-pressure impulse (42.8, 39.6 kPa x s) and peak pressures (83.5, 80.0 kPa) during the stance phase. The pressure impulse (-10.5, -13.3 kPa x s), average (-21.2, -26.5 kPa), and peak (-28.5, -36.3 kPa) negative pressures during swing phase were significantly greater in magnitude with the vacuum-assisted socket. We believe that lower positive pressures seen during stance using the vacuum-assisted socket reduces the fluid forced out and greater negative pressures seen during swing increases the amount of fluid drawn into the limb, thereby preventing volume loss.

  10. Effect of Stiffness of Rolling Joints on the Dynamic Characteristic of Ball Screw Feed Systems in a Milling Machine

    Directory of Open Access Journals (Sweden)

    Dazhong Wang

    2015-01-01

    Full Text Available Dynamic characteristic of ball screw feed system in a milling machine is studied numerically in this work. In order to avoid the difficulty in determining the stiffness of rolling joints theoretically, a dynamic modeling method for analyzing the feed system is discussed, and a stiffness calculation method of the rolling joints is proposed based on the Hertz contact theory. Taking a 3-axis computer numerical control (CNC milling machine set ermined as a research object, the stiffness of its fixed joint between the column and the body together with the stiffness parameters of the rolling joints is evaluated according to the Takashi Yoshimura method. Then, a finite element (FE model is established for the machine tool. The correctness of the FE model and the stiffness calculation method of the rolling joints are validated by theoretical and experimental modal analysis results of the machine tool’s workbench. Under the two modeling methods of joints incorporating the stiffness parameters and rigid connection, a theoretical modal analysis is conducted for the CNC milling machine. The natural frequencies and modal shapes reveal that the joints’ dynamic characteristic has an important influence on the dynamic performance of a whole machine tool, especially for the case with natural frequency and higher modes.

  11. Experimental study of reinforced concrete pile caps with external, embedded and partially embedded socket with smooth interface

    Directory of Open Access Journals (Sweden)

    R. Barros

    Full Text Available On Precast concrete structures the column foundation connections can occur through the socket foundation, which can be embedded, partially embedded or external, with socket walls over the pile caps. This paper presents an experimental study about two pile caps reinforced concrete with external, partially embedded and embedded socket submitted to central load, using 1:2 scaled models. In the analyzed models, the smooth interface between the socket walls and column was considered. The results are compared to a reference model that presents monolithic connections between the column and pile cap. It is observed that the ultimate load of pile cap with external sockets has the same magnitude as the reference pile cap, but the ultimate load of models with partially embedded and embedded socket present less magnitude than the reference model.

  12. A physically-motivated model describing the dynamic interactions between residual limb and socket in lower limb prostheses

    Directory of Open Access Journals (Sweden)

    Noll Veronika

    2017-03-01

    Full Text Available The amputee’s well-being and mobility are distinclty related to socket fit and resulting biomechanical interaction between residual limb and prosthetic socket. Understanding the dynamic interactions at the interface may lead to new socket standards. This paper introduces a physically-motivated reduced model of the interface, describing the dynamic interactions between residual limb and prosthetic socket. The model allows to investigate the sensitivity to changes of specific parameters in an isolated matter. A simulation study shows how stress distribution changes if friction coefficients are varied which might advance liner design.

  13. Surface EMG and intra-socket force measurement to control a prosthetic device

    Science.gov (United States)

    Sanford, Joe; Patterson, Rita; Popa, Dan

    2015-06-01

    Surface electromyography (SEMG) has been shown to be a robust and reliable interaction method allowing for basic control of powered prosthetic devices. Research has shown a marked decrease in EMG-classification efficiency throughout activities of daily life due to socket shift and movement and fatigue as well as changes in degree of fit of the socket throughout the subject's lifetime. Users with the most severe levels of amputation require the most complex devices with the greatest number of degrees of freedom. Controlling complex dexterous devices with limited available inputs requires the addition of sensing and interaction modalities. However, the larger the amputation severity, the fewer viable SEMG sites are available as control inputs. Previous work reported the use of intra-socket pressure, as measured during wrist flexion and extension, and has shown that it is possible to control a powered prosthetic device with pressure sensors. In this paper, we present data correlations of SEMG data with intra-socket pressure data. Surface EMG sensors and force sensors were housed within a simulated prosthetic cuff fit to a healthy-limbed subject. EMG and intra-socket force data was collected from inside the cuff as a subject performed pre-defined grip motions with their dominant hand. Data fusion algorithms were explored and allowed a subject to use both intra-socket pressure and SEMG data as control inputs for a powered prosthetic device. This additional input modality allows for an improvement in input classification as well as information regarding socket fit through out activities of daily life.

  14. How Magnus Bends the Flying Ball--Experimenting and Modeling

    Science.gov (United States)

    Timková, V.; Ješková, Z.

    2017-01-01

    Students are well aware of the effect of the deflection of sports balls when they have been given a spin. A volleyball, tennis, or table tennis ball served with topspin results in an additional downward force that makes the ball difficult to catch and return. In soccer, the effect of sidespin causes the ball to curve unexpectedly sideways,…

  15. 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.

  16. Automatic ball bar for a coordinate measuring machine

    Science.gov (United States)

    Jostlein, Hans

    1997-01-01

    An automatic ball bar for a coordinate measuring machine determines the accuracy of a coordinate measuring machine having at least one servo drive. The apparatus comprises a first and second gauge ball connected by a telescoping rigid member. The rigid member includes a switch such that inward radial movement of the second gauge ball relative to the first gauge ball causes activation of the switch. The first gauge ball is secured in a first magnetic socket assembly in order to maintain the first gauge ball at a fixed location with respect to the coordinate measuring machine. A second magnetic socket assembly secures the second gauge ball to the arm or probe holder of the coordinate measuring machine. The second gauge ball is then directed by the coordinate measuring machine to move radially inward from a point just beyond the length of the ball bar until the switch is activated. Upon switch activation, the position of the coordinate measuring machine is determined and compared to known ball bar length such that the accuracy of the coordinate measuring machine can be determined.

  17. The design and structural analysis of the endoprosthesis of the shoulder joint

    Directory of Open Access Journals (Sweden)

    Karpiński Robert

    2017-01-01

    Full Text Available The shoulder joint is a crucial element of the upper limb and is necessary to maintain full mobility during daily activities. Similar as in the hip, it is an example of a ball and socket joint, enabling articulation between the head of the humerus and the glenoid cavity of the scapula. By studying kinematics of upper limbs, it is possible to distinct several possible movements in the shoulder joint. Due to many painful diseases and medical conditions, it may be crucial to perform a pain reducing procedure, like shoulder joint replacement. In order to preserve the function of the joint, the endoprosthesis should be designed exclusively for the patient. To assess a scale of damage in the joint or its specific structure, the shoulder was scanned using the computed tomography procedure. Results of the scan were processed with the use of Materialise Mimics software, which converts standard 2D images into 3D CAD models. Necessary analysis and measurements were taken leading to the beginning of the designing process. The prosthesis was created using Solid Edge software, developed especially for the purpose of rapid prototyping. After determining the physical properties of structural materials, the Finite Elements Analysis of the model was conducted using SolidWorks Simulation software under various load conditions.

  18. 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.

  19. Applying IDL Sockets to VSO

    Science.gov (United States)

    Zarro, D. M.

    2004-05-01

    Research Systems Inc. (RSI) introduced support for TCP/IP sockets in Interactive Data Language (IDL) version 5.0. These sockets provide capabilities for remote data access in IDL that are routinely available in languages such as C, PERL, and Java. I will describe how the RHESSI team has incorporated IDL sockets into its analysis software. I will demonstrate how we program and use sockets to access worldwide-distributed archived RHESSI data and synoptic observations. The ideas and techniques that we have implemented lend themselves naturally to VSO applications.

  20. Marker-based method to measure movement between the residual limb and a transtibial prosthetic socket.

    Science.gov (United States)

    Childers, Walter Lee; Siebert, Steven

    2016-12-01

    Limb movement between the residuum and socket continues to be an underlying factor in limb health, prosthetic comfort, and gait performance yet techniques to measure this have been underdeveloped. Develop a method to measure motion between the residual limb and a transtibial prosthetic socket. Single subject, repeated measures with mathematical modeling. The gait of a participant with transtibial amputation was recorded using a motion capture system using a marker set that included arrays on the anterior distal tibia and the lateral epicondyle of the femur. The proximal or distal translation, anterior or posterior translation, and angular movements were quantified. A random Monte Carlo simulation based on the precision of the motion capture system and a model of the bone moving under the skin explored the technique's accuracy. Residual limb tissue stiffness was modeled as a linear spring based on data from Papaioannou et al. Residuum movement relative to the socket went through ~30 mm, 18 mm, and 15° range of motion. Root mean squared errors were 5.47 mm, 1.86 mm, and 0.75° when considering the modeled bone-skin movement in the proximal or distal, anterior or posterior, and angular directions, respectively. The measured movement was greater than the root mean squared error, indicating that this method can measure motion between the residuum and socket. The ability to quantify movement between the residual limb and the prosthetic socket will improve prosthetic treatment through the evaluation of different prosthetic suspensions, socket designs, and motor control of the prosthetic interface. © The International Society for Prosthetics and Orthotics 2015.

  1. 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

  2. Generation Mechanism of Linear and Angular Ball Velocity in Baseball Pitching

    Directory of Open Access Journals (Sweden)

    Sekiya Koike

    2018-02-01

    Full Text Available The purpose of this study was to quantify the functional roles of the whole-body’s joint torques including fingers’ joints in the generation of ball speed and spin during baseball fast-ball pitching motion. The dynamic contributions of joint torque term, gravitational term, and motion-dependent term (MDT consisting of centrifugal force and Coriolis force, to the generation of the ball variables were calculated using two types of models. Motion and ground reaction forces of a baseball pitcher, who was instructed to throw a fastball into the target, were measured with a motion capture system with two force platforms. The results showed (1 the MDT is the largest contributor to ball speed (e.g., about 31 m/s prior to ball release when using 16-segment model, and (2 the horizontal adduction torque of pitching-side shoulder joint plays a crucial role in generating ball speed with conversion of the MDT into other terms using a recurrence formula.

  3. Developing RESTful services with JAX-RS 2.0, WebSockets, and JSON

    CERN Document Server

    Kalali, Masoud

    2013-01-01

    Written as an easy and practical guide, this book is a crash course on using JAX-RS 2.0, JSON, and WebSockets to develop RESTful services.Getting Started with Developing RESTful Web Services using JAX-RS 2.0, JSON, and WebSockets is a perfect reading source for application developers who are familiar with Java EE and are keen to understand the new HTML5-related functionality introduced in Java EE 7 to improve productivity. To take full advantage of this book, you need to be familiar with Java EE and have some basic understanding of using the GlassFish application server.

  4. Postextraction socket grafting using calcium phosphate cement and platelet rich fibrin

    Directory of Open Access Journals (Sweden)

    Nihal Devkar

    2014-01-01

    Full Text Available This clinical case report describes and demonstrates the successful use of calcium phosphate cement (CPC in conjunction with platelet-rich fibrin (PRF for postextraction socket grafting in maxillary right first premolar area. CPC can be molded to form a scaffold. It has been used previously for regeneration in intrabony defects, but very few clinical studies in humans have reported its use for socket grafting. In this report, we have presented a novel use of CPC in conjunction with PRF for ridge preservation after tooth extraction.

  5. 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.

  6. Parametric optimization and design validation based on finite element analysis of hybrid socket adapter for transfemoral prosthetic knee.

    Science.gov (United States)

    Kumar, Neelesh

    2014-10-01

    Finite element analysis has been universally employed for the stress and strain analysis in lower extremity prosthetics. The socket adapter was the principal subject of interest due to its importance in deciding the knee motion range. This article focused on the static and dynamic stress analysis of the designed hybrid adapter developed by the authors. A standard mechanical design validation approach using von Mises was followed. Four materials were considered for the analysis, namely, carbon fiber, oil-filled nylon, Al-6061, and mild steel. The paper analyses the static and dynamic stress on designed hybrid adapter which incorporates features of conventional male and female socket adapters. The finite element analysis was carried out for possible different angles of knee flexion simulating static and dynamic gait situation. Research was carried out on available design of socket adapter. Mechanical design of hybrid adapter was conceptualized and a CAD model was generated using Inventor modelling software. Static and dynamic stress analysis was carried out on different materials for optimization. The finite element analysis was carried out on the software Autodesk Inventor Professional Ver. 2011. The peak value of von Mises stress occurred in the neck region of the adapter and in the lower face region at rod eye-adapter junction in static and dynamic analyses, respectively. Oil-filled nylon was found to be the best material among the four with respect to strength, weight, and cost. Research investigations on newer materials for development of improved prosthesis will immensely benefit the amputees. The study analyze the static and dynamic stress on the knee joint adapter to provide better material used for hybrid design of adapter. © The International Society for Prosthetics and Orthotics 2013.

  7. 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.

  8. Clinical and histologic outcomes of socket grafting after flapless tooth extraction: a systematic review of randomized controlled clinical trials.

    Science.gov (United States)

    Jambhekar, Shantanu; Kernen, Florian; Bidra, Avinash S

    2015-05-01

    Several biomaterials and techniques have been reported for socket grafting and alveolar ridge preservation. However, the evidence for clinical and histologic outcomes for socket grafting with different types of materials in flapless extraction is not clear. The purpose of this systematic review was to analyze the outcomes of a socket grafting procedure performed with flapless extraction of teeth in order to determine which graft material results in the least loss of socket dimensions, the maximum amount of vital bone, the least remnant graft material, and the least amount of connective tissue after a minimum of 12 weeks of healing. Secondary outcomes, including the predictability of regenerating deficient buccal bone, necessity of barrier membranes, and coverage with autogenous soft tissue graft, were also evaluated. An electronic search for articles in the English-language literature was performed independently by multiple investigators using a systematic search process with the PubMed search engine. After applying predetermined inclusion and exclusion criteria, the final list of randomized controlled clinical trials (RCTs) for flapless extraction and socket grafting was analyzed to derive results for the various objectives of the study. The initial electronic search resulted in 2898 titles. The systematic application of inclusion and exclusion criteria resulted in 32 RCTs studying 1354 sockets, which addressed the clinical and histologic outcomes of flapless extraction with socket grafting and provided dimensional and histologic information at or beyond the 12-week reentry period. From these RCTs, the mean loss of buccolingual width at the ridge crest was lowest for xenografts (1.3 mm), followed by allografts (1.63 mm), alloplasts (2.13 mm), and sockets without any socket grafting (2.79 mm). Only 3 studies reported on loss of width at 3 mm below the ridge crest. The mean loss of buccal wall height from the ridge crest was lowest for xenografts (0.57 mm) and

  9. A comparison of trans-tibial amputee suction and vacuum socket conditions.

    Science.gov (United States)

    Board, W J; Street, G M; Caspers, C

    2001-12-01

    Daily volume loss of the stump leads to a poor fit of the prosthetic socket. A method of preventing this volume loss and maintaining a good fit was developed. A vacuum (-78 kPa) was drawn on the expulsion port of a total surface-bearing suction socket to hold the liner tightly against the socket. Stump volume of 10 trans-tibial amputees was measured prior to and immediately after a 30 minute walk with normal and vacuum socket conditions. Under the normal condition, the limb lost an average of 6.5% of its volume during the walk. In contrast, with the liner held tightly by vacuum, the limb gained an average of 3.7% in volume. It is believed that the difference observed between conditions resulted from a greater negative pressure developed during the swing phase of gait with the vacuum condition. X-rays revealed that the limb and tibia pistoned 4 mm and 7 mm less, respectively, under the vacuum condition. The combination of reduced pistoning and maintenance of volume is thought to account for the more symmetrical gait observed with the vacuum.

  10. 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

  11. 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…

  12. An anthropomorphic transhumeral prosthesis socket developed based on an oscillometric pump and controlled by force-sensitive resistor pressure signals.

    Science.gov (United States)

    Razak, N A Abd; Gholizadeh, H; Hasnan, N; Osman, N A Abu; Fadzil, S S Mohd; Hashim, N A

    2017-02-01

    While considering the importance of the interface between amputees and prosthesis sockets, we study an anthropomorphic prosthesis socket whose size can be dynamically changed according to the requirements of the residual limb. First, we introduce the structure and function of the anthropomorphic prosthesis socket. Second, we study the dynamic model of the prosthesis system and analyze the dynamic characteristics of the prosthesis socket system, the inputs of an oscillometric pump, and the control mechanism of force-sensitive resistor (FSR) pressure signals. Experiments on 10 healthy subjects using the designed system yield an average detection result between 102 and 112 kPa for the FSR pressure sensor and 39 and 41 kPa for the oscillometric pump. Results show the function of the FSR pressure signal in maintaining the contact pressure between the sockets and the residual limb. The potential development of an auto-adjusted socket that uses an oscillometric pump system will provide prosthetic sockets with controllable contact pressure at the residual limb. Moreover, this development is an attractive research area for researchers involved in rehabilitation engineering, prosthetics, and orthotics.

  13. Paddle Angle and Ball Spin in Table Tennis

    Directory of Open Access Journals (Sweden)

    Binvant Broca

    2017-01-01

    Full Text Available The relationship between the impact angle of a table tennis ball with respect to the paddle and angular velocity of the ball leaving the paddle was investigated. A table tennis ball was dropped onto a paddle oriented at impact angles ranging from 10° to 80°. It was found that the sine of the impact angle is proportional to the angular velocity of the ball as it leaves the paddle for all impact angles tested.

  14. The benefits of using a vacuum-assisted socket system to improve balance and gait in elderly transtibial amputees.

    Science.gov (United States)

    Samitier, C Beatriz; Guirao, Lluis; Costea, Maria; Camós, Josep M; Pleguezuelos, Eulogio

    2016-02-01

    Lower limb amputation leads to impaired balance, ambulation, and transfers. Proper fit of the prosthesis is a determining factor for successful ambulation. Vacuum-assisted socket systems extract air from the socket, which decreases pistoning and probability of soft-tissue injuries and increases proprioception and socket comfort. To investigate the effect of vacuum-assisted socket system on transtibial amputees' performance-based and perceived balance, transfers, and gait. Quasi-experimental before-and-after study. Subjects were initially assessed using their prosthesis with the regular socket and re-evaluated 4 weeks after fitting including the vacuum-assisted socket system. We evaluated the mobility grade using Medicare Functional Classification Level, Berg Balance Scale, Four Square Step Test, Timed Up and Go Test, the 6-Min Walk Test, the Locomotor Capabilities Index, Satisfaction with Prosthesis (SAT-PRO questionnaire), and Houghton Scale. A total of 16 unilateral transtibial dysvascular amputees, mean age 65.12 (standard deviation = 10.15) years. Using the vacuum-assisted socket system, the patients significantly improved in balance, gait, and transfers: scores of the Berg Balance Scale increased from 45.75 (standard deviation = 6.91) to 49.06 (standard deviation = 5.62) (p gait, and transfers in over-50-year-old dysvascular transtibial amputees. This study gives more insight into the use of vacuum-assisted socket systems to improve elderly transtibial dysvascular amputees' functionality and decrease their risk of falls. The use of an additional distal valve in the socket should be considered in patients with a lower activity level. © The International Society for Prosthetics and Orthotics 2014.

  15. Temperature and Coefficient of Restitution of a Table Tennis Ball

    Directory of Open Access Journals (Sweden)

    Yoonyoung Chang

    2016-01-01

    Full Text Available The coefficient of restitution (COR of a bouncing table tennis ball was measured at varying ball temperatures with a Motion Detector. It was found that there is a negative linear relationship between the COR and the temperature of the table tennis ball for temperatures ranging from 5 to 56 ̊C.

  16. Temperature and Coefficient of Restitution of a Table Tennis Ball

    OpenAIRE

    Yoonyoung Chang

    2016-01-01

    The coefficient of restitution (COR) of a bouncing table tennis ball was measured at varying ball temperatures with a Motion Detector. It was found that there is a negative linear relationship between the COR and the temperature of the table tennis ball for temperatures ranging from 5 to 56 ̊C.

  17. Implementing a Remote Laboratory Experience into a Joint Engineering Degree Program: Aerodynamic Levitation of a Beach Ball

    Science.gov (United States)

    Jernigan, S. R.; Fahmy, Y.; Buckner, G. D.

    2009-01-01

    This paper details a successful and inexpensive implementation of a remote laboratory into a distance control systems course using readily available hardware and software. The physical experiment consists of a beach ball and a dc blower; the control objective is to make the height of the aerodynamically levitated beach ball track a reference…

  18. The dual-zone therapeutic concept of managing immediate implant placement and provisional restoration in anterior extraction sockets.

    Science.gov (United States)

    Chu, Stephen J; Salama, Maurice A; Salama, Henry; Garber, David A; Saito, Hanae; Sarnachiaro, Guido O; Tarnow, Dennis P

    2012-01-01

    Improvements in implant designs have helped advance successful immediate anterior implant placement into fresh extraction sockets. Clinical techniques described in this case enable practitioners to achieve predictable esthetic success using a method that limits the amount of buccal contour change of the extraction site ridge and potentially enhances the thickness of the peri-implant soft tissues coronal to the implant-abutment interface. This approach involves atraumatic tooth removal without flap elevation, and placing a bone graft into the residual gap around an immediate fresh-socket anterior implant with a screw-retained provisional restoration acting as a prosthetic socket seal device.

  19. Apparatus and method for inspecting a bearing ball

    Science.gov (United States)

    Bankston, B. F. (Inventor)

    1985-01-01

    A method and apparatus for inspecting the surface of a ball bearing is disclosed which includes a base having a high friction non-abrasive base scanning surface. A holding device includes a cone-shaped cup recess in which a ball element is received. Air is introduced through a passage to relieve friction between the wall of the recess and the ball element and facilitate rolling of the ball over the high friction base surface. The holding device is moved over the base scanning surface in a predetermined pattern such that the entire surface of the ball element is inspected byan eddy current probe which detects any surface defects.

  20. [Dislocation of the PIP-Joint - Treatment of a common (ball)sports injury].

    Science.gov (United States)

    Müller-Seubert, Wibke; Bührer, Gregor; Horch, Raymund E

    2017-09-01

    Background  Fractures or fracture dislocations of the proximal interphalangeal joint often occur during sports or accidents. Dislocations of the PIP-joint are the most common ligamentary injuries of the hand. As this kind of injury is so frequent, hand surgeons and other physicians should be aware of the correct treatment. Objectives  This paper summarises the most common injury patterns and the correct treatment of PIP-joint dislocations. Materials and Methods  This paper reviews the current literature and describes the standardised treatment of PIP-joint dislocations. Results  What is most important is that reposition is anatomically correct, and this should be controlled by X-ray examination. Depending on the instability and possible combination with other injuries (e. g. injury to the palmar plate), early functional physiotherapy of the joint or a short immobilisation period is indicated. Conclusions  Early functional treatment of the injured PIP-joint, initially using buddy taping, is important to restore PIP-joint movement and function. Depending on the injury, joint immobilisation using a K-wire may be indicated. Detailed informed consent is necessary to explain to the patient the severity of the injury and possible complications, such as chronic functional disorders or development of arthrosis. © Georg Thieme Verlag KG Stuttgart · New York.

  1. Hygrothermal Effect on Mechanical and Fatigue Properties of laminated Lower Limb Socket and Bacteria Growth

    Directory of Open Access Journals (Sweden)

    Fadhel Abbas Abdullah

    2016-12-01

    Full Text Available In this work, hygrothermal effect on the mechanical and fatigue properties of prosthetic socket lamination and its effect on the bacteria growth were studied. Two laminations composite materials were used in manufacturing prosthetic socket by using vacuum device. The reinforced materials of these laminations were perlon and carbon nanopowder (CNP while the matrix material was polyurethane resin. Tests performed in this work were the moisture absorption properties test to calculate percent moisture content according to ASTM 5229, tensile and fatigue tests with and without the hygrothermal effect to find the mechanical and fatigue properties, and the bacteria growth test under the hygrothermal effect to calculate the number of bacteria on the laminations. The results showed that the lamination (10 perlon+1 wt % CNP has mechanical properties than lamination (10 perlon with and without hygrothermal effect. The mechanical and fatigue properties for the two laminations were decreasing with increasing temperature and moisture.. Adding carbon nanopowder to the lamination (10 perlon increased ultimate stress, modulus of elastic, and endurance limit by (1.36, 2.35, and2.72 time respectively. Finally, the results showed that the Staphylococcus aureus growth increases with increasing temperature and moisture on the two laminations used in manufacturing prosthetic socket, and adding carbon nanopowder also increased the Staphylococcus aureus growth on the lamination.

  2. Integrated Voltage—Current Monitoring and Control of Gas Metal Arc Weld Magnetic Ball-Jointed Open Source 3-D Printer

    Directory of Open Access Journals (Sweden)

    Yuenyong Nilsiam

    2015-11-01

    Full Text Available To provide process optimization of metal fabricating self-replicating rapid prototyper (RepRap 3-D printers requires a low-cost sensor and data logger system to measure current (I and voltage (V of the gas metal arc welders (GMAW. This paper builds on previous open-source hardware development to provide a real-time measurement of welder I-V where the measuring circuit is connected to two analog inputs of the Arduino that is used to control the 3-D printer itself. Franklin firmware accessed through a web interface that is used to control the printer allows storing the measured values and downloading those stored readings to the user’s computer. To test this custom current and voltage monitoring device this study reports on its use on an upgraded all metal RepRap during the printing of aluminum alloy (ER1100, ER4043, ER4943, ER4047, and ER5356. The voltage and current data were analyzed on a per alloy basis and also layer-by-layer in order to evaluate the device’s efficacy as a monitoring device for 3-D printing and the results of the integrated design are discussed.

  3. Ball Machine Usage in Tennis: Movement Initiation and Swing Timing While Returning Balls from a Ball Machine and from a Real Server

    Directory of Open Access Journals (Sweden)

    Jan Carboch, Vladimir Süss, Tomas Kocib

    2014-06-01

    Full Text Available Practicing with the use of a ball machine could handicap a player compared to playing against an actual opponent. Recent studies have shown some differences in swing timing and movement coordination, when a player faces a ball projection machine as opposed to a human opponent. We focused on the time of movement initiation and on stroke timing during returning tennis serves (simulated by a ball machine or by a real server. Receivers’ movements were measured on a tennis court. In spite of using a serving ball speed from 90 kph to 135 kph, results showed significant differences in movement initiation and backswing duration between serves received from a ball machine and serves received from a real server. Players had shorter movement initiation when they faced a ball machine. Backswing duration was longer for the group using a ball machine. That demonstrates different movement timing of tennis returns when players face a ball machine. Use of ball machines in tennis practice should be limited as it may disrupt stroke timing.

  4. Implementing the WebSocket Protocol Based on Formal Modelling and Automated Code Generation

    DEFF Research Database (Denmark)

    Simonsen, Kent Inge; Kristensen, Lars Michael

    2014-01-01

    Model-based software engineering offers several attractive benefits for the implementation of protocols, including automated code generation for different platforms from design-level models. In earlier work, we have proposed a template-based approach using Coloured Petri Net formal models...... with pragmatic annotations for automated code generation of protocol software. The contribution of this paper is an application of the approach as implemented in the PetriCode tool to obtain protocol software implementing the IETF WebSocket protocol. This demonstrates the scalability of our approach to real...... protocols. Furthermore, we perform formal verification of the CPN model prior to code generation, and test the implementation for interoperability against the Autobahn WebSocket test-suite resulting in 97% and 99% success rate for the client and server implementation, respectively. The tests show...

  5. 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.

  6. 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.

  7. Joint Replacement (Finger and Wrist Joints)

    Science.gov (United States)

    ... wrist joints can all be replaced (Figure 1). Artificial joints in the hand may help: Reduce joint pain Restore or maintain joint motion Improve the look and alignment of the joint(s) Improve overall hand function Causes In a normal joint, bones have a smooth surface made of a substance ...

  8. The nonlinear and ball pass effects of a ball bearing on rotor vibration

    International Nuclear Information System (INIS)

    Han, D. C.; Choi, S. H.; Lee, Y. H.; Kim, K. H.

    1998-01-01

    A ball bearing is generally assumed as a linear spring in rotor dynamic analysis. In real case, the force equilibrium of the bearing is changed as the relative position of each ball with respect to the direction of radial force. So, the stiffness of the bearing is also changed and is a function of time and position. In this study, the nonlinear characteristics of a ball bearing are considered in analyzing the vibration response of a rotating shaft due to an unbalance force. A finite element method is used to analyze the vibration characteristics of a rotor-bearing system and a direct numerical integration is performed to calculate the transient response of the rotor system. The responses are converted to the frequency domain and the effects of the parametric excitation due to a ball bearing are examined. The test rig for the investigation of the effect of a ball bearing on the rotor vibration is set up and the results are compared with those of numerical calculation. The calculation results show that the amplitudes of the nonlinear model are larger than those of the linear one. The frequencies of the calculations can be matched to the measured frequencies

  9. Ball clay

    Science.gov (United States)

    Virta, Robert L.

    2010-01-01

    The article reports on the global market performance of ball clay in 2009 and presents an outlook for its 2010 performance. Several companies mined ball call in the country including Old Hickey Clay Co., Kentucky-Tennessee Clay Co., and H.C. Spinks Clay Co. Information on the decline in ball clay imports and exports is also presented.

  10. 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.

  11. Fun with Balls and Coins

    Indian Academy of Sciences (India)

    ing things to offer to the students to get excited and think about. ..... photons travel at same speed)? For fun, imagine Ishant. Sharma taking a .... RESONANCE │ January 2011. GENERAL │ ARTICLE. S N Bose's work on particle statistics which clarified the behaviour of photons and opened the door to new ideas on.

  12. 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

  13. Spherical microwave confinement and ball lightning

    Science.gov (United States)

    Robinson, William Richard

    This dissertation presents the results of research done on unconventional energy technologies from 1995 to 2009. The present civilization depends on an infrastructure that was constructed and is maintained almost entirely using concentrated fuels and ores, both of which will run out. Diffuse renewable energy sources rely on this same infrastructure, and hence face the same limitations. I first examined sonoluminescence directed toward fusion, but demonstrated theoretically that this is impossible. I next studied Low Energy Nuclear Reactions and developed methods for improving results, although these have not been implemented. In 2000, I began Spherical Microwave Confinement (SMC), which confines and heats plasma with microwaves in a spherical chamber. The reactor was designed and built to provide the data needed to investigate the possibility of achieving fusion conditions with microwave confinement. A second objective was to attempt to create ball lightning (BL). The reactor featured 20 magnetrons, which were driven by a capacitor bank and operated in a 0.2 s pulse mode at 2.45 GHz. These provided 20 kW to an icosahedral array of 20 antennas. Video of plasmas led to a redesign of the antennas to provide better coupling of the microwaves to the plasma. A second improvement was a grid at the base of the antennas, which provided corona electrons and an electric field to aid quick formation of plasmas. Although fusion conditions were never achieved and ball lightning not observed, experience gained from operating this basic, affordable system has been incorporated in a more sophisticated reactor design intended for future research. This would use magnets that were originally planned. The cusp geometry of the magnetic fields is suitable for electron cyclotron resonance in the same type of closed surface that in existing reactors has generated high-temperature plasmas. Should ball lightning be created, it could be a practical power source with nearly ideal

  14. The heads and tails of buoyant autocatalytic balls

    Science.gov (United States)

    Rogers, Michael C.; Morris, Stephen W.

    2012-09-01

    Buoyancy produced by autocatalytic reaction fronts can produce fluid flows that advect the front position, giving rise to interesting feedback between chemical and hydrodynamic effects. In this paper, we numerically investigate the evolution of autocatalytic iodate-arsenous acid reaction fronts initialized in spherical configurations. Deformation of these "autocatalytic balls" is driven by buoyancy produced by the reaction. In our simulations, we have found that depending on the initial ball radius, the reaction front will develop in one of three different ways. In an intermediate range of ball size, the flow can evolve much like an autocatalytic plume: the ball develops a reacting head and tail that is akin to the head and conduit of an autocatalytic plume. In the limit of large autocatalytic balls, however, growth of a reacting tail is suppressed and the resemblance to plumes disappears. Conversely, very small balls of product solution fail to initiate sustained fronts and eventually disappear.

  15. Bone physiology in human grafted and non-grafted extraction sockets--an immunohistochemical study.

    Science.gov (United States)

    Nahles, Susanne; Nack, Claudia; Gratecap, Kerrin; Lage, Hermann; Nelson, John J; Nelson, Katja

    2013-07-01

    The aim of the present immunohistological investigation was to define and compare the osteogenic potential with the vascularization of the provisional matrix in grafted and ungrafted extraction sockets after 4 and 12 weeks of healing. A total of 33 Patients (15 women, 18 men) with 65 extraction sites with a mean age of 54.4 years (30-73 years) participated in this study. After tooth extraction, the sockets were augmented with Bio-Oss collagen or non-augmented. At implant placement after 4 or 12 weeks bone biopsies were obtained. Within the specimens the osteogenic and endothelial potential of mesenchymal cells was analyzed in the provisional matrix using immunohistochemical analysis with three monoclonal antibodies Cbfa1/Runx2, Osteocalcin (OC), and CD31. Statistical analysis was performed using Mann-Whitney U-test, Spearman's rank-order correlation coefficient, and the two-factorial analysis for repeated measurements. Of the 65 extraction sockets, 25 (13 non-augmented, 12 augmented) sites after 4 weeks healing time and 40 (19 non-augmented, 21 augmented) sites after 12 weeks healing time were involved in the study. No signs of acute or chronic inflammation were noted in any specimens. After 4 weeks, a median amount of 56% (10-85%) of Cbfa1 positive cells and a median amount of cells expressing OC of 21% (5-42%) were measured. A median CD31 score of 5 was observed. After 12 weeks, a median amount of 61% (19-90%) positive cells expressed by Cbfa1/Runx2 staining a median amount of OC positive cells of 9% (2-17%) was measured. The results at 12 weeks revealed a median score of CD31 positive cells of 3. Osteoblastic activity in the provisional matrix was highest after 4 weeks of healing period. The active zone of bone formation is found in the apical region of the extraction socket during the early healing phase, shifting to the coronal region after 12 weeks. A peak of osteoblast activity within the first weeks is followed by a reduction in mature

  16. 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.

  17. Computer-Aided Socket Design For Amputees

    Science.gov (United States)

    Novicov, Aleksey; Foort, James

    1983-07-01

    The fitting of sockets and artificial legs to amputees' stumps is a difficult and lengthy process that can take numerous trials. It has been proposed that most amputees can be fitted with a standard socket shape with minimal changes to the socket. To perform this task, a procedure is being developed at the Medical Engineering Resource Unit for computer aided socket design for amputees. An interactive PASCAL program, operating on a microcomputer, will prompt the operator (or prosthetist) by asking him to determine the condition of the stump. While the operator is inputing this information into the computer, together with a few critical anatomical measurements, a standard socket shape, viewed on the video monitor, will begin to change. Throughout the "shape fitting" procedure, the operator will have the ability to modify the socket shape on the screen with the use of a light pen. It will also be possible to view various cross-sections and different perspectives. The shape fitting procedure continues until a suitable socket shape is designed. Future efforts will focus on transferring the computer designed socket into a physical socket. The overall goal is to provide amputees with a better fit in less time and to objectify socket fitting so that new prosthetists may be easily taught.

  18. Immediate provisionalization of dental implants placed in healed alveolar ridges and extraction sockets: a 5-year prospective evaluation.

    Science.gov (United States)

    Cooper, Lyndon F; Reside, Glenn J; Raes, Filiep; Garriga, Joan Soliva; Tarrida, Luis Giner; Wiltfang, Jörg; Kern, Matthias; De Bruyn, Hugo

    2014-01-01

    This 5-year prospective multicenter study compared implant survival and success, peri-implant health and soft tissue responses, crestal bone level stability, and complication rates following immediate loading of single OsseoSpeed implants placed in anterior maxillary healed ridges or extraction sockets. Individuals requiring anterior tooth replacement with single implants were treated and immediately provisionalized. Definitive all-ceramic crowns were placed at 12 weeks. Implant survival, bone levels, soft tissue levels, and peri-implant health were monitored for 5 years. One hundred thirteen patients received implants in fresh sockets (55) and healed ridges (58). After 5 years, 45 and 49 patients remained for evaluation, respectively. During the first year, three implants failed in the extraction socket group (94.6% survival) and one implant failed in the healed ridge group (98.3% survival); this difference was not significant. No further implant failures were recorded. After 5 years, the interproximal crestal bone levels were located a mean of 0.43 ± 0.63 mm and 0.38 ± 0.62 mm from the reference points of implants in sockets and healed ridges (not a significant difference). In both groups, papillae increased over time and peri-implant mucosal zenith positions were stable from the time of definitive crown placement in sockets and healed ridges. Compared to flap surgery for implants in healed ridges, flapless surgery resulted in increased peri-implant mucosal tissue dimension (average, 0.78 ± 1.34 mm vs 0.19 ± 0.79 mm). After 5 years, the bone and soft tissue parameters that characterize implant success and contribute to dental implant esthetics were similar following the immediate provisionalization of implants in sockets and healed ridges. The overall tissue responses and reported implant survival support the immediate provisionalization of dental implants in situations involving healed ridges and, under ideal circumstances, extraction sockets.

  19. Effect of Practicing Soccer Juggling With Different Sized Balls Upon Performance, Retention, and Transfer to Ball Reception.

    Science.gov (United States)

    Raastad, Olav; Aune, Tore Kristian; van den Tillaar, Roland

    2016-10-01

    The aim of this study was to investigate if making the skill acquisition phase more difficult or easier would enhance performance in soccer juggling, and if this practice has a positive intertask transfer effect to ball reception performance. Twenty-two adolescent soccer players were tested in juggling a soccer ball and in the control of an approaching ball at a pre, post and retention test. The participants were randomly divided in a small ball size and bigger ball size training group that both trained four times per week for 6 weeks. At the post and retention test both groups enhanced performance in soccer juggling test with no difference between groups and no increase in ball reception performance at these tests. It was concluded that about intra task transfer and retention of soccer juggling skills, it does not matter if you increase (small balls) or decrease the difficulty (larger balls) when using the same amount of practice time within the skill acquisition phase in soccer juggling. In addition that for ball juggling and ball reception (inter task) these two tasks differ too much in afferent information and movement characteristics that no positive transfer between these two skills no positive intertask transfer can be expected.

  20. Vacuum-assisted socket suspension compared with pin suspension for lower extremity amputees: effect on fit, activity, and limb volume.

    Science.gov (United States)

    Klute, Glenn K; Berge, Jocelyn S; Biggs, Wayne; Pongnumkul, Suporn; Popovic, Zoran; Curless, Brian

    2011-10-01

    To investigate the effect of a vacuum-assisted socket suspension system as compared with pin suspension on lower extremity amputees. Randomized crossover with 3-week acclimation. Household, community, and laboratory environments. Unilateral, transtibial amputees (N=20 enrolled, N=5 completed). (1) Total surface-bearing socket with a vacuum-assisted suspension system (VASS), and (2) modified patellar tendon-bearing socket with a pin lock suspension system. Activity level, residual limb volume before and after a 30-minute treadmill walk, residual limb pistoning, and Prosthesis Evaluation Questionnaire. Activity levels were significantly lower while wearing the vacuum-assisted socket suspension system than the pin suspension (P=.0056; 38,000 ± 9,000 steps per 2 wk vs 73,000 ± 18,000 steps per 2 wk, respectively). Residual limb pistoning was significantly less while wearing the vacuum-assisted socket suspension system than the pin suspension (P=.0021; 1 ± 3mm vs 6 ± 4mm, respectively). Treadmill walking had no effect on residual limb volume. In general, participants ranked their residual limb health higher, were less frustrated, and claimed it was easier to ambulate while wearing a pin suspension compared with the VASS. The VASS resulted in a better fitting socket as measured by limb movement relative to the prosthetic socket (pistoning), although the clinical relevance of the small but statistically significant difference is difficult to discern. Treadmill walking had no effect, suggesting that a skilled prosthetist can control for daily limb volume fluctuations by using conventional, nonvacuum systems. Participants took approximately half as many steps while wearing the VASS which, when coupled with their subjective responses, suggests a preference for the pin suspension system. Copyright © 2011 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  1. Portable Library of Migratable Sockets

    OpenAIRE

    Bubak, Marian; Żbik, Dariusz; Albada, Dick van; Iskra, Kamil; Sloot, Peter

    2001-01-01

    Efficient load balancing is essential for parallel distributed computing. Many parallel computing environments use TCP or UDP through the socket interface as a communication mechanism. This paper presents the design and development of a prototype implementation of a network interface that can preserve communication between processes during process migration. This new communication library is a substitution for the well-known socket interface. It is implemented in user — space; it is portable,...

  2. Simulated studies of wear and friction in total hip prosthesis components with various ball sizes and surface finishes

    Science.gov (United States)

    Swikert, M. A.; Johnson, R. L.

    1976-01-01

    Experiments were conducted on a newly designed total hip joint simulator. The apparatus closely simulates the complex motions and loads of the human hip in normal walking. The wear and friction of presently used appliance configurations and materials were determined. A surface treatment of the metal femoral ball specimens was applied to influence wear. The results of the investigation indicate that wear can be reduced by mechanical treatment of metal femoral ball surfaces. A metallographic examination and surface roughness measurements were made.

  3. Accuracy and Reliability of a New Tennis Ball Machine.

    Science.gov (United States)

    Brechbuhl, Cyril; Millet, Grégoire; Schmitt, Laurent

    2016-06-01

    The aim was to evaluate the reliability of a newly-developed ball machine named 'Hightof', on the field and to assess its accuracy. The experiment was conducted in the collaboration of the 'Hawk-Eye' technology. The accuracy and reliability of this ball machine were assessed during an incremental test, with 1 min of exercise and 30 sec of recovery, where the frequency of the balls increased from 10 to 30 balls·min(-1). The initial frequency was 10 and increased by 2 until 22, then by 1 until 30 balls·min(-1). The reference points for the impact were 8.39m from the net and 2.70m from lateral line for the right side and 2.83m for the left side. The precision of the machine was similar on the right and left sides (0.63 ± 0.39 vs 0.63 ± 0.34 m). The distances to the reference point were 0.52 ± 0.42, 0.26 ± 0.19, 0.52 ± 0.37, 0.28 ± 0.19 m for the Y-right, X-right, Y-left and X-left impacts. The precision was constant and did not increase with the intensity. (e.g ball frequency). The ball velocity was 86.3 ± 1.5 and 86.5 ± 1.3 km·h(-1) for the right and the left side, respectively. The coefficient of variation for the velocity ranged between 1 and 2% in all stages (ball velocity ranging from 10 to 30 balls·min(-1)). both the accuracy and the reliability of this new ball machine appear satisfying enough for field testing and training. Key pointsThe reliability and accuracy of a new ball machine named 'Hightof' were assessed.The impact point was reproducible and similar on the right and left sides (±0.63 m).The precision was constant and did not increase with the intensity (e.g ball frequency).The coefficient of variation of the ball velocity ranged between 1 and 2% in all stages (ball velocity ranging from 10 to 30 balls·min(-1)).

  4. Phenomenon of ball lightning and its outgrowths

    Energy Technology Data Exchange (ETDEWEB)

    Torchigin, V.P. [Institute of Informatics Problems, Russian Academy of Sciences, Nakhimovsky prospect 36/1, 119278 Moscow (Russian Federation)]. E-mail: v_torchigin@mail.ru; Torchigin, A.V. [Institute of Informatics Problems, Russian Academy of Sciences, Nakhimovsky prospect 36/1, 119278 Moscow (Russian Federation)

    2005-03-28

    New physical phenomena deduced from properties of ball lightning are considered under assumption that ball lightning is a light bubble comprising of a thin spherical layer of compressed air where an intense light circulates in all possible directions. Explanation of behavior of autonomous luminous objects produced at gas discharge is presented.

  5. Dry Socket following Tooth Extraction in an Iranian Dental Center: Incidence and Risk Factors Dry Socket following Tooth Extraction in an Iranian Dental Center: Incidence and Risk Factors

    Directory of Open Access Journals (Sweden)

    Majid Eshghpour

    2013-07-01

    Full Text Available Introduction: Dry Socket (DS is a common post-surgical complication following extraction of permanent teeth. Various risk factors has been mentioned for this complication including gender, age, amount of trauma during extraction, difficulty of extraction, inappropriate irrigation, infection, smoking, and oral contraceptive use. The aim of this study was to evaluate the incidence of DS among permanent teeth extraction in an Iranian Oral and Maxillofacial clinic and also to identify risk factors. Methods: This cross-sectional study performed at Mashhad Faculty of Dentistry between January 2009 and June 2009. Total of 785 patients who underwent non-surgical extraction of permanent teeth included in this study. A questionnaire with two sections designed to collect demographic, medical, and extraction-related data along with data regarding cases returning with DS. Data were reported descriptively and analyzed using Chi-square test with 95% confidence interval. Results: Total of 1073 teeth included in this study. 46.11% of patients were male and 53.89% were female. The mean age of participants was 32.68 ± 17.63 years. Total of 31 patients (2.89% were diagnosed with dry socket. Smoking and oral contraceptives intake had significant association with incidence of DS. In contrast, age, gender, medical status, tooth location, number of anesthetic carpules, anesthetic technique, pre-extraction antibiotic consumption, and academic year of students had no significant association with the incidence of DS. All cases with DS treated and were followed until resolution of DS. Conclusion: it is recommended to identify high risk groups (smokers and oral contraceptive takers when performing extraction and to perform preventive measures in these group of patients to attenuate postoperative complications.

  6. RELATIONSHIP BETWEEN MEDICINE BALL EXPLOSIVE POWER TESTS, THROWING BALL VELOCITY AND JUMP PERFORMANCE IN TEAM HANDBALL PLAYERS

    Directory of Open Access Journals (Sweden)

    Mourad Fathloun

    2011-04-01

    Full Text Available In this study, the relationships between medicine ball explosive power tests, jump and handball throwing velocity performance in team handball players were investigated. Explosive test was measured by a medicine ball throw. Specific explosive strength was evaluated by making 3 types of overarm throw: standing position, using an adapted chair (without run-up, T w , a 3-step running throw (T 3-Steps and a jump shot (J S . The jump test (SJ, CMJ and FCMJ were determined using the OptoJump. The medicine ball explosive power test was closely related to T 3-Steps . Significant relationships were observed between medicine ball explosive power tests and (J S and (T w . The Medicine ball explosive power test is also positively related to vertical jump ability represented by Squat Jump (SJ and Countermovement Jump (CMJ. The results suggest an association of the medicine ball explosive power tests to performance in throwing events

  7. Socket preservation using freeze-dried bone allograft with and without plasma rich in growth factors in dogs

    Directory of Open Access Journals (Sweden)

    Mohammad Hasan Samandari

    2016-01-01

    Full Text Available Background: Plasma rich in growth factors (PRGF and freeze-dried bone allograft (FDBA are shown to promote bone healing. This study was aimed to histologically and histomorphometrically investigate the effect of combined use of PRGF and FDBA on bone formation, and compare it to FDBA alone and control group. Materials and Methods: The distal roots of the lower premolars were extracted bilaterally in four female dogs. Sockets were randomly divided into FDBA + PRGF, FDBA, and control groups. Two dogs were sacrificed after 2 weeks and two dogs were sacrificed after 4 weeks. Sockets were assessed histologically and histomorphometrically. Data were analyzed by Kruskal-Wallis test followed by Mann-Whitney U-tests utilizing the SPSS software version 20. P < 0.05 was considered statistically significant. Results: While the difference in density of fibrous tissue in three groups was not statistically significant (P = 0.343, the bone density in grafted groups was significantly higher than the control group (P = 0.021. The least decrease in all socket dimensions was observed in the FDBA group. However, these differences were only significant in coronal portion at week 4. Regarding socket dimensions and bone density, the difference between FDBA and FDBA+PRGF groups was not significant in middle and apical portions. Conclusion: The superiority of PRGF+FDBA overFDBA in socket preservation cannot be concluded from this experiment.

  8. Improvement of construction and technology of manufacture car suspension ball bearing

    Directory of Open Access Journals (Sweden)

    M.M. Kosiiuk

    2017-12-01

    Full Text Available The necessity of improvement of spherical articulated joints is proved on the example of a ball bearing of a forward suspension bracket of a car. The purpose of the work is to improve the design and technology of manufacturing the ball hinge of the car suspension to improve its operational capabilities by increasing the durability of the spherical tribosystem «ball finger–liner». The ways of increasing the durability of spherical articulated joints by design and technological methods were formulated. The main factors of influence on the process of wear of spherical tribosystem «finger-liner» were considered. Taking into account the existing experience and results of the conducted studies, a self-regulated ball joint with an elastic element of the original design was developed. On the basis of the kinematic scheme of sphere manufacturing, a device for turning the incomplete spherical surface of a finger of high accuracy was developed. For hardening of partial spherical surfaces by surface plastic deformation developed by static-pulse device, which provides the layer with a heterogeneous structure, required physical and mechanical properties and geometrically determined lubricant-retaining microrelief. The results of this work in future will be planned to generalize and used for the manufacture of competitive products that contains parts with incomplete spherical surfaces.

  9. 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.

  10. 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

  11. 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.)

  12. Differences in Femoral Head Penetration Between Highly Cross-Linked Polyethylene Cemented Sockets and Uncemented Liners.

    Science.gov (United States)

    Morita, Daigo; Seki, Taisuke; Higuchi, Yoshitoshi; Takegami, Yasuhiko; Ishiguro, Naoki

    2017-12-01

    This study aimed at investigating differences in femoral head penetration between highly cross-linked polyethylene (HXLPE) cemented sockets and uncemented liners during 5 years postoperatively. Ninety-six patients (106 hips) with a mean age of 64.4 (range, 35-83) years underwent total hip arthroplasty using a HXLPE cemented socket or liner and were respectively divided into cemented (35 patients [37 hips]) and uncemented (61 patients [69 hips]) groups. Femoral head penetrations were evaluated on both anteroposterior (AP)-view and Lauenstein-view radiographs, and mean polyethylene (PE) wear rates were calculated based on femoral head penetration from 2 to 5 years. Multivariate analyses were performed to assess risk factors for PE wear. At 5 years postoperatively, the cemented and uncemented groups exhibited proximal direction femoral head penetrations of 0.103 mm and 0.124 mm (P = .226) and anterior direction penetrations of 0.090 mm and 0.151 mm (P = .002), respectively. The corresponding mean PE wear rates were 0.004 mm/y and 0.009 mm/y in the AP-view (P = .286) and 0.005 mm/y and 0.012 mm/y in the Lauenstein-view (P = .168), respectively. Left-side operation and high activity were independent risk factors for PE wear on AP-view. When HXLPE was used, all mean PE wear rates were very low and those of cemented sockets and uncemented liners were very similar. PE particle theory suggests that the occurrence of osteolysis and related aseptic loosening might consequently decrease. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. Bone grafting of alveolar socket and ovate seat pontic preparation for natural emergence profile for anterior bridge - A case report

    Directory of Open Access Journals (Sweden)

    Vijay Deshmukh

    2009-01-01

    Full Text Available Alveolar atrophy following tooth extraction remains a challenge for future prosthetic restorations. Immediate implant placement and postextraction alveolar bone grafting are two methods that are used to prevent significant postextraction bone loss. Grafting is one of the most common methods of socket preservation widely used to prevent the collapse of oral tissues following extraction so that an excellent esthetic prosthesis can be provided particularly in the anterior maxillary region. The present report describes the management of a maxillary tooth extraction socket using a socket preservation technique involving placement of an osteoconductive slowly resorbable grafting material & resorbable collagen membrane in the extraction socket also called as Bio-Col socket preservation technique followed by a provisional restoration to preserve the tissues & interdental papilla for the placement of future final ovate pontic anterior bridge to give the illusion of the tooth emerging from the gums. This technique resulted in a successful prevention of alveolar bone loss following tooth extraction & maintainence of tissue contour & density which provided a good tissue base for the fabrication of Ovate pontic giving excellent esthetic results.

  14. 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…

  15. How Magnus Bends the Flying Ball - Experimenting and Modeling

    Science.gov (United States)

    Timková, V.; Ješková, Z.

    2017-02-01

    Students are well aware of the effect of the deflection of sports balls when they have been given a spin. A volleyball, tennis, or table tennis ball served with topspin results in an additional downward force that makes the ball difficult to catch and return. In soccer, the effect of sidespin causes the ball to curve unexpectedly sideways, resulting in a so-called banana kick that can confuse the goalkeeper. These surprising effects attract students' attention such that the motion of sports balls can be used to capture the interest of students towards the physics behind it. However, to study and analyze the motion of a real ball kicked in a playfield is not an easy task. Instead of the large-scale full-size sports ball motion, there can be designed and studied simpler experiments that can be carried out in the classroom. Moreover, digital technologies that are available at schools enable students to collect data from the experiment easily in a reasonable time. The mathematical model based on the analysis of forces acting on the ball flying in the air can be used to simulate the motion in order to understand the basic physical principles of the motion so that the best correspondence may be found.

  16. The definitive guide to HTML5 WebSocket

    CERN Document Server

    Wang, Vanessa; Moskovits, Peter

    2013-01-01

    The Definitive Guide to HTML5 WebSocket is the ultimate insider's WebSocket resource. This revolutionary new web technology enables you to harness the power of true real-time connectivity and build responsive, modern web applications.   This book contains everything web developers and architects need to know about WebSocket. It discusses how WebSocket-based architectures provide a dramatic reduction in unnecessary network overhead and latency compared to older HTTP (Ajax) architectures, how to layer widely used protocols such as XMPP and STOMP on top of WebSocket, and how to secure WebSocket c

  17. Acetabular reconstruction with impaction bone grafting and cemented polyethylene socket in total hip revision arthroplasty.

    Science.gov (United States)

    Kostensalo, I; Seppänen, M; Virolainen, P; Mokka, J; Koivisto, M; Mäkelä, K T

    2015-12-01

    Bone deficiency in revision total hip arthroplasty is a challenge to the surgeon. One option for restoration of the bone stock is impaction bone grafting and use of a cemented socket. The aim of this study was to evaluate the mid-term clinical outcome of impaction bone grafting and cemented socket revisions. A total of 59 patients (60 hips) underwent revision arthroplasty with impaction bone grafting and application of a cemented socket on the acetabular side in the Turku University Hospital from 1999 to 2004. The study end-point was re-revision for any reason. The cumulative percentages for survival were followed and estimated with Kaplan-Meier curves. Associations between occurrence of re-revision and potential risk factors were analyzed with logistic regression. Results were quantified by odd ratios and 95% confidence intervals. The mean age of the patients was 69 years (33% male). A total of 3% of the patients had a class I Paprosky acetabular defect, 38% had class II, and 55% had class III. The overall survival rate was 73%. The mean follow-up time was 7 years. The most common reason for re-revision was aseptic loosening of the acetabular component (13 patients, 81% of re-revisions). Cox's regression analysis did not identify any risk factors for re-revision. Our results were inferior compared to some previous studies. Impaction bone grafting of acetabular defects in revision total hip arthroplasty may not always provide a reliable bone stock in long-term. © The Finnish Surgical Society 2015.

  18. Immediate Loading of Tapered Implants Placed in Postextraction Sockets and Healed Sites.

    Science.gov (United States)

    Han, Chang-Hun; Mangano, Francesco; Mortellaro, Carmen; Park, Kwang-Bum

    2016-07-01

    The aim of the present study was to compare the survival, stability, and complications of immediately loaded implants placed in postextraction sockets and healed sites. Over a 2-year period, all patients presenting with partial or complete edentulism of the maxilla and/or mandible (healed site group, at least 4 months of healing after tooth extraction) or in need of replacement of nonrecoverable failing teeth (postextraction group) were considered for inclusion in this study. Tapered implants featuring a nanostructured calcium-incorporated surface were placed and loaded immediately. The prosthetic restorations comprised single crowns, fixed partial dentures, and fixed full arches. Primary outcomes were implant survival, stability, and complications. Implant stability was assessed at placement and at each follow-up evaluation (1 week, 3 months, and 1 year after placement): implants with an insertion torque (IT) implant stability quotient (ISQ) immediate loading. A statistical analysis was performed. Thirty implants were placed in postextraction sockets of 17 patients, and 32 implants were placed in healed sites of 22 patients. There were no statistically significant differences in ISQ values between the 2 groups, at each assessment. In total, 60 implants (96.8%) had an IT ≥45 and an ISQ ≥70 at placement and at each follow-up control: all these implants were successfully loaded. Only 2 implants (1 in a postextraction socket and 1 in a healed site, 3.2%) could not achieve an IT ≥45 N·cm and/or an ISQ ≥70 at placement or over time: accordingly, these were considered failed for stability, as they could not be subjected to immediate loading. One of these 2 implants, in a healed site of a posterior maxilla, had to be removed, yielding an overall 1-year implant survival rate of 98.4%. No complications were reported. No significant differences were reported between the 2 groups with respect to implant failures and complications. Immediately loaded implants placed

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

    Science.gov (United States)

    Sacks, William; Mauger, Alain

    2013-11-01

    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.

  20. 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.

  1. Flapless alveolar ridge preservation utilizing the "socket-plug" technique: clinical technique and review of the literature.

    Science.gov (United States)

    Kotsakis, Georgios; Chrepa, Vanessa; Marcou, Nicolas; Prasad, Hari; Hinrichs, James

    2014-12-01

    It has been documented that after every extraction of one or more teeth, the alveolar bone of the respective region undergoes resorption and atrophy. Therefore, ridge preservation techniques are often employed after tooth extraction to limit this phenomenon. The benefits of a flapless procedure include maintenance of the buccal keratinized gingiva, prevention of alterations to the gingival contours, and migration of the mucogingival junction that are often experienced after raising a flap. The purpose of this article is to review the literature concerning flapless ridge preservation techniques with the aid of collagen plugs for occlusion of the socket. The term "socket-plug" technique is introduced to describe these techniques. The basic steps of the "socket-plug" technique consist of atraumatic tooth extraction, placement of the appropriate biomaterials in the extraction site, preservation of soft tissue architecture employing a flapless technique, and placement and stabilization of the collagen plug. A case example is presented that illustrates the steps used in this technique.

  2. Walk and roll robot

    Science.gov (United States)

    Wilson, Andrew (Inventor); Punnoose, Andrew (Inventor); Strausser, Katherine (Inventor); Parikh, Neil (Inventor)

    2011-01-01

    A mobile robotic unit features a main body, a plurality of legs for supporting the main body on and moving the main body in forward and reverse directions about a base surface, and a drive assembly. According to an exemplary embodiment each leg includes a respective pivotal hip joint, a pivotal knee joint, and a wheeled foot adapted to roll along the base surface. Also according to an exemplary embodiments the drive assembly includes a motor operatively associated with the hip and knee joints and the wheeled foot for independently driving pivotal movement of the hip joint and the knee joint and rolling motion of the wheeled foot. The hip joint may include a ball-and-socket-type joint interconnecting top portion of the leg to the main body, such that the hip joint is adapted to pivot said leg in a direction transverse to a forward-and-reverse direction.

  3. Ball lightning.

    OpenAIRE

    Stenhoff, Mark

    1988-01-01

    Ball lightning is alleged by some to be a rare atmospheric phenomenon usually associated with thunderstorms, while others hold that it does not exist. This controversy has continued for centuries. This study comprises a critical evaluation of evidence for the existence of ball lightning. An historical review of the controversy is first presented, giving a chronological account of developments in ball lightning theories and of important observations alleged to be of the phenomenon. Other pheno...

  4. A development methodology for a remote inspection system with JAVA and socket

    International Nuclear Information System (INIS)

    Choi, Yoo Rark; Lee, Jae Cheol; Kim, Jae Hee

    2004-01-01

    We have developed RISYS (Reactor Inspection System) which inspects reactor vessel welds by an underwater mobile robot. The system consists of a main control computer and an inspection robot which is controlled by the main control computer. Since the environments of the inspection tasks in a nuclear plant, like in other industrial fields, is very poor, serious accidents often happen. Therefore the necessity for remote inspection and control system has increased more and more. We have carried out the research for a remote inspection model for RISYS, and have adopted the world wide web, java, and socket technologies for it. Client interface to access the main control computer that controls the inspection equipment is essential for the development of a remote inspection system. It has been developed with a traditional programming language, for example, Visual C++, Visual Basic and X-Window. However, it is too expensive to vend and maintain the version of a interface program because of the different computer O/S. Nevertheless web and java technologies come to the fore to solve the problems but the java interpreting typed language could incur a performance problem in operating the remote inspection system. We suggest a methodology for developing a remote inspection system with java, a traditional programming language, and a socket programming that solves the java performance problem in this paper

  5. Ball clay

    Science.gov (United States)

    Virta, R.L.

    2000-01-01

    Part of the 1999 Industrial Minerals Review. The state of the ball clay industry in 1999 is presented. Record highs in the sales and use of ball clay were attained in 1999 due to the continued strength of the U.S. economy. U.S. production was estimated at 1.25 million st for the year, with more than half of that amount mined in Tennessee. Details of the consumption, price, imports, and exports of ball clay in 1999 and the outlook for ball clay over the next few years are provided.

  6. 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

  7. 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.

  8. 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.

  9. Science of Ball Lightning (Fire Ball)

    Science.gov (United States)

    Ohtsuki, Yoshi-Hiko

    1989-08-01

    The Table of Contents for the full book PDF is as follows: * Organizing Committee * Preface * Ball Lightning -- The Continuing Challenge * Hungarian Ball Lightning Observations in 1987 * Nature of Ball Lightning in Japan * Phenomenological and Psychological Analysis of 150 Austrian Ball Lightning Reports * Physical Problems and Physical Properties of Ball Lightning * Statistical Analysis of the Ball Lightning Properties * A Fluid-Dynamical Model for Ball Lightning and Bead Lightning * The Lifetime of Hill's Vortex * Electrical and Radiative Properties of Ball Lightning * The Candle Flame as a Model of Ball Lightning * A Model for Ball Lightning * The High-Temperature Physico-Chemical Processes in the Lightning Storm Atmosphere (A Physico-Chemical Model of Ball Lightning) * New Approach to Ball Lightning * A Calculation of Electric Field of Ball Lightning * The Physical Explanation to the UFO over Xinjiang, Northern West China * Electric Reconnection, Critical Ionization Velocity, Ponderomotive Force, and Their Applications to Triggered and Ball Lightning * The PLASMAK™ Configuration and Ball Lightning * Experimental Research on Ball Lightning * Performance of High-Voltage Test Facility Designed for Investigation of Ball Lightning * List of Participants

  10. 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.

  11. Ban Deodorant Ball Mortar.

    Science.gov (United States)

    Carpenter, D. Rae, Jr.; And Others

    1988-01-01

    Discusses a demonstration of vertical collision of two balls. Shows the theoretical height ratio using mathematical expression and diagrams. Compares it with researchers' experimental results. Expands the two-ball collision to multi-ball system. (YP)

  12. X-Windows Socket Widget Class

    Science.gov (United States)

    Barry, Matthew R.

    2006-01-01

    The X-Windows Socket Widget Class ("Class" is used here in the object-oriented-programming sense of the word) was devised to simplify the task of implementing network connections for graphical-user-interface (GUI) computer programs. UNIX Transmission Control Protocol/Internet Protocol (TCP/IP) socket programming libraries require many method calls to configure, operate, and destroy sockets. Most X Windows GUI programs use widget sets or toolkits to facilitate management of complex objects. The widget standards facilitate construction of toolkits and application programs. The X-Windows Socket Widget Class encapsulates UNIX TCP/IP socket-management tasks within the framework of an X Windows widget. Using the widget framework, X Windows GUI programs can treat one or more network socket instances in the same manner as that of other graphical widgets, making it easier to program sockets. Wrapping ISP socket programming libraries inside a widget framework enables a programmer to treat a network interface as though it were a GUI.

  13. 78 FR 29702 - Ball Bearings and Parts Thereof From Germany: Final Results of Antidumping Duty Administrative...

    Science.gov (United States)

    2013-05-21

    ... DEPARTMENT OF COMMERCE International Trade Administration [A-428-801] Ball Bearings and Parts... administrative review of the antidumping duty order on ball bearings and parts thereof from Germany. The period... ball bearings and parts thereof from Germany as the conclusion of a sunset review. See Ball Bearings...

  14. Atmospheric tar balls: Particles from biomass and biofuel burning

    Science.gov (United States)

    Pósfai, MiháLy; GelencséR, AndráS.; Simonics, RenáTa; Arató, Krisztina; Li, Jia; Hobbs, Peter V.; Buseck, Peter R.

    2004-03-01

    "Tar balls" are amorphous, carbonaceous spherules that occur in the tropospheric aerosol as a result of biomass and biofuel burning. They form a distinct group of particles with diameters typically between 30 and 500 nm and readily identifiable with electron microscopy. Their lack of a turbostratic microstructure distinguishes them from soot, and their morphology and composition (˜90 mol % carbon) renders them distinct from other carbonaceous particles. Tar balls are particularly abundant in slightly aged (minutes to hours old) biomass smoke, indicating that they likely form by gas-to-particle conversion within smoke plumes. The material of tar balls is initially hygroscopic; however, the particles become largely insoluble as a result of free radical polymerization of their organic molecules. Consequently, tar balls are primarily externally mixed with other particle types, and they do not appreciably increase in size during aging. When tar balls coagulate with water-bearing particles, their material may partly dissolve and no longer be recognizable as distinct particles. Tar balls may contain organic compounds that absorb sunlight. They are an important, previously unrecognized type of carbonaceous (organic) atmospheric particle.

  15. Ball clay

    Science.gov (United States)

    Virta, R.L.

    2013-01-01

    Four companies — H.C. Spinks Clay Co., Inc., Imerys, Old Hickory Clay Co. and Unimin Corp. — mined ball clay in five U.S. states in 2012. Production, on the basis of preliminary data, was 900 kt (992,000 st), with an estimated value of $42.3 million. This was a slight increase in tonnage from 886 kt (977,000 st), with a value of $40.9 million in 2011. Tennessee was the leading ball clay producing state, with 63 percent of domestic production, followed by Texas, Mississippi, Kentucky and Indiana. Reported ball clay production from Indiana probably was fire clay rather than ball clay. About 69 percent of total ball clay production was airfloat, 20 percent was crude and 11 percent was water-slurried.

  16. Portable Library of Migratable Sockets

    Directory of Open Access Journals (Sweden)

    Marian Bubak

    2001-01-01

    Full Text Available Efficient load balancing is essential for parallel distributed computing. Many parallel computing environments use TCP or UDP through the socket interface as a communication mechanism. This paper presents the design and development of a prototype implementation of a network interface that can preserve communication between processes during process migration. This new communication library is a substitution for the well-known socket interface. It is implemented in user — space; it is portable, and no modifications of user applications are required. TCP/IP is applied for internal communication, which guarantees relatively high performance and portability.

  17. Socket preservation using demineralized freezed dried bone allograft with and without plasma rich in growth factor: A canine study

    Directory of Open Access Journals (Sweden)

    Ahmad Mogharehabed

    2014-01-01

    Full Text Available Background: The accelerating effect of plasma rich in growth factors (PRGFs in the healing of extraction sockets has been demonstrated by some studies. The aim of the present study was to histologically and histomorphometrically evaluate whether bone formation would increase by the combined use of PRGF and demineralized freeze-dried bone allograft (DFDBA. Materials and Methods: In four female dogs, the distal root of the second, third and fourth lower premolars were extracted bilaterally and the mesial roots were preserved. The extraction sockets were randomly divided into DFDBA + PRGF, DFDBA + saline or control groups. Two dogs were sacrificed after 2 weeks and two dogs were sacrificed after 6 weeks. The extraction sockets were evaluated from both histological and histomorphometrical aspects. The data were analyzed by Mann-Whitney followed by Kruskal-Wallis tests using the Statistical Package for the Social Sciences version 20 (SPSS Inc., Chicago, IL, USA. Significant levels were set at 0.05. Results: The least decrease in socket height was observed in the DFDBA + PRGF group (0.73 ± 0.42 mm. The least decrease in the coronal portion was observed in the DFDBA + PRGF group (1.38 ± 1.35 mm². The least decrease in the middle surface was observed in the DFDBA group (0.61 ± 0.80 mm². The least decrease in the apical portion was observed in the DFDBA group (0.34 ± 0.39 mm². Conclusion: The present study showed better socket preservation subsequent to the application of DFDBA and PRGF combination in comparison with the two other groups. However, the difference was not statistically significant.

  18. Regenerative Needs Following Alveolar Ridge Preservation Procedures in Compromised and Noncompromised Extraction Sockets: A Cone Beam Computed Tomography Study.

    Science.gov (United States)

    Koutouzis, Theofilos; Lipton, David

    2016-01-01

    The aim of this study was to evaluate the necessity for additional regenerative procedures following healing of compromised and noncompromised extraction sockets with alveolar ridge preservation procedures through the use of virtual implant imaging software. The cohort was comprised of 87 consecutive patients subjected to a single maxillary tooth extraction with an alveolar ridge preservation procedure for subsequent implant placement. Patients were divided into two main groups based on the integrity of the buccal bone plate following teeth extraction. Patients in the compromised socket (CS) group (n = 52) had partial or complete buccal bone plate loss, and patients in the noncompromised socket (NCS) group (n = 35) exhibited no bone loss of their socket walls following tooth extraction. Following 4 to 6 months of healing, all patients had a cone beam computed tomography (CBCT) study. Root-formed implants were placed virtually in an ideal prosthetic position. The number of implants per group and location (anterior, premolar, molar) exhibiting exposed buccal implant surface was calculated. In the CS group, 5 out of 19 anterior implants (26.3%), 4 out of 14 premolar implants (28.5%), and 7 out of 19 molar implants (36.8%) had exposed buccal surfaces. In the NCS group, 4 out of 9 anterior implants (44.4%), 2 out of 9 premolar implants (22.2%), and 4 out of 17 molar implants (23.5%) had exposed buccal surfaces. There were no statistically significant differences for intragroup and intergroup comparisons (χ² test, P > .05). This study failed to find statistically significant differences in the frequency of implants with exposed buccal surfaces placed virtually, following treatment of compromised and noncompromised sockets. A high proportion (22% to 44%) of sites had implants that potentially needed additional regenerative procedures.

  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. Acute neuropathic joint in diabetic foot: Plain radiographic findings

    International Nuclear Information System (INIS)

    Yoon, Dae Young; Kang, Heung Sik; Sim, Jung Suk; Yoon, Yong Kyu; Kim, Chu Wan

    1994-01-01

    To determine the plain film findings of acute neuropathic joint in diabetic foot. Acute neuropathic joint in diabetic foot was considered when fragmentation of the articular ends of bone and subluxation of the affected joint developed within eight weeks after clinical onset of diabetic gangrene. Eight toes of six diabetics were satisfactory to our criteria. We analyzed plain radiographic findings of the affected joint and soft tissue, interval changes in followed-up radiographs, and deformities after healing. The time interval between clinical onset of gangrene and bone destruction ranges from 2 weeks to 4 weeks(mean 2.6 weeks). Plane radiographs showed fragmentation of the articular ends, subluxation, and soft tissue swelling of the metatarsophalangeal joint or interphalangeal joint. The significant feature of these patients was rapid progression of the lesions. Clinically, all patients had diabetic gangrene in affected toes, however, there was no evidence of osteomyelitis in our series. Amputation was done in 2 cases, and lesions in 3 of the remaining 4 cases were repaired spontaneously with regression of gangrene, leaving radiological residua such as pointed-end, tapered-end, and ball and socket deformity. Rapid disorganisation of the joint with associated evidence of soft tissue gangrene in plain radiograph is believed to be valuable for the diagnosis of diabetic osteoarthropathy

  1. Acute neuropathic joint in diabetic foot: Plain radiographic findings

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Dae Young; Kang, Heung Sik; Sim, Jung Suk; Yoon, Yong Kyu; Kim, Chu Wan [Seoul National University College of Medicine, Seoul (Korea, Republic of)

    1994-05-15

    To determine the plain film findings of acute neuropathic joint in diabetic foot. Acute neuropathic joint in diabetic foot was considered when fragmentation of the articular ends of bone and subluxation of the affected joint developed within eight weeks after clinical onset of diabetic gangrene. Eight toes of six diabetics were satisfactory to our criteria. We analyzed plain radiographic findings of the affected joint and soft tissue, interval changes in followed-up radiographs, and deformities after healing. The time interval between clinical onset of gangrene and bone destruction ranges from 2 weeks to 4 weeks(mean 2.6 weeks). Plane radiographs showed fragmentation of the articular ends, subluxation, and soft tissue swelling of the metatarsophalangeal joint or interphalangeal joint. The significant feature of these patients was rapid progression of the lesions. Clinically, all patients had diabetic gangrene in affected toes, however, there was no evidence of osteomyelitis in our series. Amputation was done in 2 cases, and lesions in 3 of the remaining 4 cases were repaired spontaneously with regression of gangrene, leaving radiological residua such as pointed-end, tapered-end, and ball and socket deformity. Rapid disorganisation of the joint with associated evidence of soft tissue gangrene in plain radiograph is believed to be valuable for the diagnosis of diabetic osteoarthropathy.

  2. Healing of Postextraction Sockets Preserved With Autologous Platelet Concentrates. A Systematic Review and Meta-Analysis.

    Science.gov (United States)

    Del Fabbro, Massimo; Bucchi, Cristina; Lolato, Alessandra; Corbella, Stefano; Testori, Tiziano; Taschieri, Silvio

    2017-08-01

    The true benefit of autologous platelet concentrates (APCs) for enhancing the healing of postextraction sites is still a matter of debate, and in recent years several clinical trials have addressed this issue. The purpose of this study was to determine the effectiveness of an APC adjunct in the preservation of fresh extraction sockets. An electronic search was performed on Medline, Embase, Scopus, and the Cochrane Central Register of Controlled Trials. Only controlled clinical trials or randomized clinical trials were included. Selected articles underwent risk-of-bias assessment. The outcomes were complications and adverse events, discomfort and quality of life, bone healing and remodeling assessed by histologic and radiographic techniques, and soft tissue healing. Thirty-three comparative studies were included. Nine articles had a parallel design and 24 had a split-mouth design. Twenty studies were considered to have a low risk of bias and 13 were considered to have a high risk. Overall, 1,193 teeth were extracted from 911 patients. Meta-analysis showed that soft tissue healing, probing depth at 3 months, and bone density at 1, 3, and 6 months were statistically better for the APC group. Qualitative analysis suggested that APCs might be associated with a decrease in swelling and trismus. However, no relevant difference among groups was found for probing depth at 1 month, incidence of alveolar osteitis, acute inflammation or infection, percentage of new bone, and indirect measurement of bone metabolism. APCs should be used in postextraction sites to improve clinical and radiographic outcomes such as bone density and soft tissue healing and postoperative symptoms. The actual benefit of APCs on decreasing pain in extraction sockets is still not quantifiable. Copyright © 2017 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

  3. Periodontal and endodontic pathology delays extraction socket healing in a canine model

    Science.gov (United States)

    2017-01-01

    Purpose The aim of the present exploratory study was to evaluate extraction socket healing at sites with a history of periodontal and endodontic pathology. Methods The mandibular 4th premolar teeth in 5 adult beagle dogs served as experimental units. Periodontal and endodontic lesions were induced in 1 premolar site in each animal using wire ligatures and pulpal exposure over 3 months (diseased sites). The contralateral premolar sites served as healthy controls. The mandibular 4th premolar teeth were then extracted with minimal trauma, followed by careful wound debridement. The animals were sacrificed at days 1, 7, 30, 60, and 90 post-extraction for analysis, and the healing patterns at the healthy and diseased extraction sites were compared using radiography, scanning electron microscopy, histology, and histometry. Results During the first 7 days of healing, a significant presence of inflammatory granulation tissue was noted at the diseased sites (day 1), along with a slightly accelerated rate of fibrin clot resolution on day 7. On day 30, the diseased extraction sites showed a greater percentage of persistent fibrous connective tissue, and an absence of bone marrow formation. In contrast, healthy sites showed initial signs of bone marrow formation on day 30, and subsequently a significantly greater proportion of mature bone marrow formation on both days 60 and 90. Radiographs exhibited sclerotic changes adjoining apical endodontic lesions, with scanning electron microscopy showing collapsed Volkmann canals protruding from these regions in the diseased sites. Furthermore, periodontal ligament fibers exhibited a parallel orientation to the alveolar walls of the diseased sites, in contrast to a perpendicular arrangement in the healthy sites. Conclusions Within the limitations of this study, it appears that a history of periodontal and endodontic pathology may critically affect bone formation and maturation, leading to delayed and compromised extraction socket

  4. The Effect of Prosthetic Socket Interface Design on Socket Comfort, Residual Limb Health, and Function for the Transfemoral Amputee

    Science.gov (United States)

    2017-10-01

    underway. What opportunities for training and professional development has the project provided? A Mechanical Engineering undergraduate student was...original copies of journal articles, reprints of manuscripts and abstracts, a curriculum vitae, patent applications, study questionnaires, and

  5. Joint Instability and Osteoarthritis

    Directory of Open Access Journals (Sweden)

    Darryl Blalock

    2015-01-01

    Full Text Available Joint instability creates a clinical and economic burden in the health care system. Injuries and disorders that directly damage the joint structure or lead to joint instability are highly associated with osteoarthritis (OA. Thus, understanding the physiology of joint stability and the mechanisms of joint instability-induced OA is of clinical significance. The first section of this review discusses the structure and function of major joint tissues, including periarticular muscles, which play a significant role in joint stability. Because the knee, ankle, and shoulder joints demonstrate a high incidence of ligament injury and joint instability, the second section summarizes the mechanisms of ligament injury-associated joint instability of these joints. The final section highlights the recent advances in the understanding of the mechanical and biological mechanisms of joint instability-induced OA. These advances may lead to new opportunities for clinical intervention in the prevention and early treatment of OA.

  6. The Effect of Prosthetic Socket Interface Design on Socket Comfort, Residual Limb Health, and Function for the Transfemoral Amputee

    Science.gov (United States)

    2016-10-01

    for the Transfemoral Amputee PRINCIPAL INVESTIGATOR: M. Jason Highsmith CONTRACTING ORGANIZATION: University of South Florida Tampa, FL 33620 REPORT...and Function for the Transfemoral Amputee 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Highsmith, M. Jason 5d...There are two alternative interface designs for the military and veteran above knee amputee that could provide answers to issues germane to above

  7. 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.

  8. Reconstructing mandibular anterior region by Branemark and Bonefit joint implants: a case report

    OpenAIRE

    AR. Rokn; F. Geramipanah

    1998-01-01

      A 48 year old patient was candidate for anterior mandibular reconstruction by 2 fixtures of Branemark implant. Residual infection lead to removal of one of the implants from the extracted tooth socket. Afterwards, 2 fixtures of Bonefit was inserted adjacent to previously placed Branemark implants and final prosthesis were loaded in a joint cemented and screwed design.

  9. Reconstructing mandibular anterior region by Branemark and Bonefit joint implants: a case report

    Directory of Open Access Journals (Sweden)

    AR. Rokn

    1998-04-01

    Full Text Available   A 48 year old patient was candidate for anterior mandibular reconstruction by 2 fixtures of Branemark implant. Residual infection lead to removal of one of the implants from the extracted tooth socket. Afterwards, 2 fixtures of Bonefit was inserted adjacent to previously placed Branemark implants and final prosthesis were loaded in a joint cemented and screwed design.

  10. Rotating and rolling rigid bodies and the "hairy ball" theorem

    Science.gov (United States)

    Bormashenko, Edward; Kazachkov, Alexander

    2017-06-01

    Rotating and rolling rigid bodies exemplify a fascinating theorem of topology, jokingly called the "hairy ball" theorem, which demands that any continuous tangent vector field on the sphere has at least one point where the field is zero. We demonstrate via a gedanken experiment how drilling through a rotating ball, thereby converting it into a torus, leads to the elimination of zero-velocity points on the ball surface. Using the same reasoning, zero-velocity points can be removed from the surface of a drilled spinning top. We discuss the location of zero-velocity points on the surfaces of rigid bodies rolling with no slip and with slip. Observations made from different reference frames identify various zero-velocity points. Illustrative experiments visualizing zero-velocity points are presented.

  11. Kinematics of table tennis topspin forehands: effects of performance level and ball spin.

    Science.gov (United States)

    Iino, Yoichi; Kojima, Takeji

    2009-10-01

    The purpose of this study was to investigate whether performance level and ball spin affect arm and racket kinematics of the table tennis topspin forehand. Nine advanced and eight intermediate male table tennis players hit topspin forehands against light and heavy backspins. Five high-speed video cameras were used to record their strokes at 200 fps. Contributions of joint rotations to the racket speed, the racket kinematics at ball impact, the time required for racket acceleration and the maximum slope of the racket speed-time curve (s(max)) were determined. The advanced players showed a significantly larger contribution of lower trunk axial rotation to the racket speed at impact and a significantly larger value of s(max), and tended to require a less time for racket acceleration than the intermediate players. The racket speed at impact was not significantly different between the two player groups. The players adjusted the racket face angle rather than the inclination of the racket path at impact to the different ball spins. The results suggest that the ability to accelerate the racket in less time in the topspin forehand against backspin balls may be an important factor that affects the performance level.

  12. Definition of the Term 'Socket Primitive' in Distributed Systems

    OpenAIRE

    Willich, Florian

    2015-01-01

    Socket Primitive’ is a heavily used term associated with network operations in computer science. A socket is a communication end point of a computer system. The word ’primitive’ is often used to name an instruction which represents a self-contained unit on the current abstraction level. Therefore, a ’Socket Primitive’ is a socket related function that is provided by various high-level programming language libraries. This technical report describes and ultimately defines the term ’Socket Prim...

  13. Keeping Your Eyes Continuously on the Ball While Running for Catchable and Uncatchable Fly Balls

    NARCIS (Netherlands)

    Postma, Dees B. W.; den Otter, A. Rob; Zaal, Frank T. J. M.

    2014-01-01

    When faced with a fly ball approaching along the sagittal plane, fielders need information for the control of their running to the interception location. This information could be available in the initial part of the ball trajectory, such that the interception location can be predicted from its

  14. The Application of Multi-threaded Socket and Picture Field Technology of DataGridView in the Development of Alarm Receiver Software

    Science.gov (United States)

    hao, Guo

    In this paper, we achieve the alarm receiving software and discuss programming ideas of the multi-threaded asynchronous receiver about SOCKET and picture field technology of DataGridView in the process of development.

  15. Characterization and Infrared Emission Spectroscopy of Ball Plasmoid Discharges

    Science.gov (United States)

    Dubowsky, Scott E.; McCall, Benjamin J.

    2015-06-01

    Plasmas at atmospheric pressure serve many purposes, from ionization sources for ambient mass spectrometry (AMS) to plasma-assisted wound healing. Of the many naturally occurring ambient plasmas, ball lightning is one of the least understood; there is currently no solid explanation in the literature for the formation and lifetime of natural ball lightning. With the first measurements of naturally occurring ball lightning being reported last year, we have worked to replicate the natural phenomenon in order to elucidate the physical and chemical processes by which the plasma is sustained at ambient conditions. We are able to generate ball-shaped plasmoids (self-sustaining plasmas) that are analogous to natural ball lightning using a high-voltage, high-current, pulsed DC system. Improvements to the discharge electronics used in our laboratory and characterization of the plasmoids that are generated from this system will be described. Infrared emission spectroscopy of these plasmoids reveals emission from water and hydroxyl radical -- fitting methods for these molecular species in the complex experimental spectra will be presented. Rotational temperatures for the stretching and bending modes of H2O along with that of OH will be presented, and the non-equilibrium nature of the plasmoid will be discussed in this context. Cen, J.; Yuan, P,; Xue, S. Phys. Rev. Lett. 2014, 112, 035001. Dubowsky, S.E.; Friday, D.M.; Peters, K.C.; Zhao, Z.; Perry, R.H.; McCall, B.J. Int. J. Mass Spectrom. 2015, 376, 39-45.

  16. Dry socket

    Science.gov (United States)

    ... 64. Hupp JR. Prevention and management of extraction complications. In: Hupp JR, Ellis E, Tucker MR, eds. Contemporary Oral and Maxillofacial Surgery . 6th ed. St. Louis, MO: Elsevier Mosby; 2014: ...

  17. Video movie making using remote procedure calls and 4BSD Unix sockets on Unix, UNICOS, and MS-DOS systems

    Energy Technology Data Exchange (ETDEWEB)

    Robertson, D.W.; Johnston, W.E.; Hall, D.E.; Rosenblum, M.

    1990-03-01

    We describe the use of the Sun Remote Procedure Call and Unix socket interprocess communication mechanisms to provide the network transport for a distributed, client-server based, image handling system. Clients run under Unix or UNICOS and servers run under Unix or MS-DOS. The use of remote procedure calls across local or wide-area networks to make video movies is addressed.

  18. 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.

  19. 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.

  20. Dynamic modelling and natural characteristic analysis of cycloid ball transmission using lumped stiffness method.

    Science.gov (United States)

    Zhang, Peng; Bao, Bingbing; Wang, Meng

    2017-01-01

    The vibration of robot joint reducer is the main factor that causes vibration or motion error of robot system. To improve the dynamic precision of robot system, the cycloid ball transmission used in robot joint is selected as study object in this paper. An efficient dynamic modelling method is presented-lumped stiffness method. Based on lumped stiffness method, a translational-torsional coupling dynamics model of cycloid ball transmission system is established. Mesh stiffness variation excitation, damping of system are all intrinsically considered in the model. The dynamic equation of system is derived by means of relative displacement relationship among different components. Then, the natural frequencies and vibration modes of the derivative system are presented by solving the associated eigenvalue problem. Finally, the influence of the main structural parameters on the natural frequency of the system is analysed. The present research can provide a new idea for dynamic analysis of robot joint reducer and provide a more simplify dynamic modelling method for robot system with joint reducer.

  1. Esthetic consideration for alveolar socket preservation prior to implant placement: description of a technique and 80-case series report.

    Science.gov (United States)

    Kutkut, Ahmad; Andreana, Sebastiano; Monaco, Edward

    2012-01-01

    An esthetic restoration supported by dental implant rehabilitation is a major challenge to restorative dentists. The ultimate goal of a dental implant is to restore missing or extracted teeth by placing implants in anatomically, esthetically, and long-term functional restorations. Alveolar ridge preservation and site enhancement following tooth extraction has a major impact on the hard and soft tissue volume. Extraction socket preservation is technique sensitive, not 100% successful, and at times unpredictable. Current techniques may delay surgical implant placement for a few months, and the quality of new bone regeneration is questionable. The aim of this report was to describe a minimally traumatic extraction socket preservation technique using different types of bone graft as a preserver prior to implant placement applied for 80 consecutive cases.

  2. Effectiveness of platelet-rich fibrin in the management of pain and delayed wound healing associated with established alveolar osteitis (dry socket).

    Science.gov (United States)

    Sharma, Ashish; Aggarwal, Nimish; Rastogi, Sanjay; Choudhury, Rupshikha; Tripathi, Siddhi

    2017-01-01

    To assess the efficacy of platelet-rich fibrin (PRF) on the pain and healing of the extraction socket related with established alveolar osteitis (dry socket, AO) after the removal of maxillary and mandibular molars. One hundred consecutive adult patients with age group ranging from 18 to 40 years along with established dry socket after maxillary and mandibular molar extractions who have not received any treatment for the same were included in this single-arm clinical trial. PRF was placed in the maxillary and mandibular molar extraction sockets after adequate irrigation of the socket. All the patients evaluated for the various study variables which include pain, degree of inflammation, and healthy granulation tissue formation (wound healing) at the 1 st , 3 rd , 7 th , and 14 th post-PRF placement day in the alveolar socket. Data were analyzed using Shapiro-Wilk's test, Chi-square test and/or Student's t -test, Friedman's test, Wilcoxon signed-rank test, and Bonferroni test, with the significance level set at P healing by the end of the 2 nd week. The use of PRF in this clinical trial illustrates the promising results in terms of reduced pain and better healing in the patients with sustained AO.

  3. Ball lightning dynamics and stability at moderate ion densities

    Science.gov (United States)

    Morrow, R.

    2017-10-01

    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 µs their influence on the ion dynamics is negligible. Further development after 1 µs 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

  4. Effects of local and whole body irradiation on the appearance of osteoblasts during wound healing in tooth extraction sockets in rats

    International Nuclear Information System (INIS)

    Hosokawa, Yoichiro; Kudo, Kohsei; Kashiwakura, Ikuo; Sakakura, Yasunori; Irie, Kazuharu

    2010-01-01

    Irradiation before tooth extraction delays wound healing in the alveolar socket. This study examined the influences of local and whole body irradiation before tooth extraction on appearance of osteoblasts in the alveolar bone of rat maxillary first molars because bone formation is observed at the initial phase of wound healing. Several osteoblasts were generated 3 days after tooth extraction, and the number of cells increased day by day. Morphological studies showed there were little differences between local irradiation and non-irradiated controls. In contrast, the extraction wound in the whole body irradiation group showed delayed healing, and there was poor granulation tissue and very few osteoblasts at the bottom of the socket. An ultrastructural study showed that the osteoblasts in the extraction socket of whole body irradiation rats were smaller, and had poorly developed organelles. Injection of bone marrow cells to whole body-irradiated animals immediately after tooth extraction partially restored the number of osteoblasts. New periosteal bone formations outside of sockets showed little delay in the whole body irradiation group. These findings suggest that bone formation in the wound healing of extraction socket requires bone marrow cells from hematopoietic organs such as the bone marrow as well as local sources around the alveolar socket, during the initial phase of wound healing. (author)

  5. Effects of local and whole body irradiation on the appearance of osteoblasts during wound healing in tooth extraction sockets in rats.

    Science.gov (United States)

    Hosokawa, Yoichiro; Sakakura, Yasunori; Irie, Kazuharu; Kudo, Kohsei; Kashiwakura, Ikuo

    2010-01-01

    Irradiation before tooth extraction delays wound healing in the alveolar socket. This study examined the influences of local and whole body irradiation before tooth extraction on appearance of osteoblasts in the alveolar bone of rat maxillary first molars because bone formation is observed at the initial phase of wound healing. Several osteoblasts were generated 3 days after tooth extraction, and the number of cells increased day by day. Morphological studies showed there were little differences between local irradiation and non-irradiated controls. In contrast, the extraction wound in the whole body irradiation group showed delayed healing, and there was poor granulation tissue and very few osteoblasts at the bottom of the socket. An ultrastructural study showed that the osteoblasts in the extraction socket of whole body irradiation rats were smaller, and had poorly developed organelles. Injection of bone marrow cells to whole body-irradiated animals immediately after tooth extraction partially restored the number of osteoblasts. New periosteal bone formations outside of sockets showed little delay in the whole body irradiation group. These findings suggest that bone formation in the wound healing of extraction socket requires bone marrow cells from hematopoietic organs such as the bone marrow as well as local sources around the alveolar socket, during the initial phase of wound healing.

  6. The prefabricated temporal island flap for eyelid and eye socket reconstruction in total orbital exenteration patients: A new method.

    Science.gov (United States)

    Altindas, Muzaffer; Yucel, Akin; Ozturk, Guncel; Sarac, Mesud; Kilic, Ali

    2010-08-01

    Anophtalmic socket reconstruction is a challenging problem in plastic surgery. We had described a prefabricated superficial temporal fascia island flap and used this technique in >50 enucleation patients with severe socket contraction ending in excellent or good results for 28 years (Altindas- 1 procedure). However, the flap was not suitable for the exenteration patients with complete eyelid loss. The technique was modified and used in exenteration patients (Altindas-2 procedure). In this 2-staged procedure, the temporoparietal fascia is prefabricated with a full-thickness skin graft from the retroauricular area, and a strip of scalp is preserved at the middle of the flap. The flap is transferred to the orbit through a subcutaneous tunnel at the second stage. The prefabricated flap is used for the reconstruction of eyelids and periorbital skin; scalp island is used for the reconstruction of lid margins and eyelashes; and the neighboring bare temporoparietal fascia is used for the augmentation of the periorbital soft tissues. The orbital lining is elevated as a centrally based skin flap and used for the reconstruction of the eye socket, fornicles, and posterior lining of the eyelids. The technique was used successfully in 5 total exenteration patients with complete eyelid loss. In 1 patient, the ipsilateral temporal island flap was used previously, and the flap was prepared from the contralateral site and transferred to the anophtalmic orbit as a free flap 5 weeks later. By this procedure, it is possible to reconstruct a stable eye socket that is suitable for ocular prosthesis, upper and lower fornicles, periorbital skin with good color matching, naturally looking eyelids with eyelashes and lid margins, and medial and lateral canthal areas. It is also possible to improve periorbital soft tissue atrophy, which is an important problem in patients who had radiotherapy previously. Free transfer of the flap provides a new solution for the reconstruction of cases that

  7. Graphene oxide scaffold accelerates cellular proliferative response and alveolar bone healing of tooth extraction socket

    Directory of Open Access Journals (Sweden)

    Nishida E

    2016-05-01

    Full Text Available Erika Nishida,1 Hirofumi Miyaji,1 Akihito Kato,1 Hiroko Takita,2 Toshihiko Iwanaga,3 Takehito Momose,1 Kosuke Ogawa,1 Shusuke Murakami,1 Tsutomu Sugaya,1 Masamitsu Kawanami11Department of Periodontology and Endodontology, Hokkaido University Graduate School of Dental Medicine, Sapporo, Japan; 2Support Section for Education and Research, Hokkaido University Graduate School of Dental Medicine, Sapporo, Japan; 3Laboratory of Histology and Cytology, Hokkaido University Graduate School of Medicine, Sapporo, JapanAbstract: Graphene oxide (GO consisting of a carbon monolayer has been widely investigated for tissue engineering platforms because of its unique properties. For this study, we fabricated a GO-applied scaffold and assessed the cellular and tissue behaviors in the scaffold. A preclinical test was conducted to ascertain whether the GO scaffold promoted bone induction in dog tooth extraction sockets. For this study, GO scaffolds were prepared by coating the surface of a collagen sponge scaffold with 0.1 and 1 µg/mL GO dispersion. Scaffolds were characterized using scanning electron microscopy (SEM, physical testing, cell seeding, and rat subcutaneous implant testing. Then a GO scaffold was implanted into a dog tooth extraction socket. Histological observations were made at 2 weeks postsurgery. SEM observations show that GO attached to the surface of collagen scaffold struts. The GO scaffold exhibited an interconnected structure resembling that of control subjects. GO application improved the physical strength, enzyme resistance, and adsorption of calcium and proteins. Cytocompatibility tests showed that GO application significantly increased osteoblastic MC3T3-E1 cell proliferation. In addition, an assessment of rat subcutaneous tissue response revealed that implantation of 1 µg/mL GO scaffold stimulated cellular ingrowth behavior, suggesting that the GO scaffold exhibited good biocompatibility. The tissue ingrowth area and DNA contents of 1

  8. A staged approach of implant placement in immediate extraction sockets for preservation of peri-implant soft and hard tissue

    OpenAIRE

    Vinnakota, Dileep Nag; Akula, Sreenivasa Rao; Krishna Reddy, V. Vamsi; Sankar, V. Vijay

    2014-01-01

    Esthetic zone restoration is a challenging aspect in implant dentistry because of two critical factors such as level of bone support and soft tissue dimensions. Preservation of healthy peri-implant tissues is of primary importance for ensuring better esthetics over an extended period. The aim of the present case-series was to evaluate a new staged approach of implant placement in immediate extraction sockets for preservation of peri-implant soft and hard tissues. Four subjects scheduled for e...

  9. Spin Rate and Deflection Ratio of a Ping Pong Ball

    Directory of Open Access Journals (Sweden)

    Byung Joon Ahn

    2013-12-01

    Full Text Available To investigate the effects of a spherical object’s spin rate on the curvature of its flight, Ping Pong balls, of varying spin rates, were hit horizontally and recorded from above with a high-speed camera. It was shown that there was a proportional relationship between the ball’s spin rate and deflection ratio. Additionally, using the results of the analyzed data, a coefficient of skin friction of the Ping Pong ball was found to be approximately 0.2 under the specific conditions of this investigation.

  10. Spin Rate and Deflection Ratio of a Ping Pong Ball

    Directory of Open Access Journals (Sweden)

    Byung Joon Ahn

    2013-01-01

    Full Text Available To investigate the effects of a spherical object’s spin rate on the curvature of its flight, Ping Pong balls, of varying spin rates, were hit horizontally and recorded from above with a high-speed camera. It was shown that there was a proportional relationship between the ball’s spin rate and deflection ratio. Additionally, using the results of the analyzed data, a coefficient of skin friction of the Ping Pong ball was found to be approximately 0.2 under the specific conditions of this investigation.

  11. A staged approach of implant placement in immediate extraction sockets for preservation of peri-implant soft and hard tissue.

    Science.gov (United States)

    Vinnakota, Dileep Nag; Akula, Sreenivasa Rao; Krishna Reddy, V Vamsi; Sankar, V Vijay

    2014-03-01

    Esthetic zone restoration is a challenging aspect in implant dentistry because of two critical factors such as level of bone support and soft tissue dimensions. Preservation of healthy peri-implant tissues is of primary importance for ensuring better esthetics over an extended period. The aim of the present case-series was to evaluate a new staged approach of implant placement in immediate extraction sockets for preservation of peri-implant soft and hard tissues. Four subjects scheduled for extraction of teeth in the esthetic zone with neither a periapical nor periodontal infection and with thick tissue biotype were included. For all the subjects sand blasted, large grit, acid etched platform switched implant with a diameter 2 mm less than the diameter of extraction socket and a conical abutment-implant connection (Morse taper) were placed 2 mm below the crest of the socket, with almost 2 mm gap between the labial plate and the implant with shoulder placed palatally/lingually. The implants were loaded after 2 months healing period and followed for a period of 1-2 years. In all the four patients there was preservation of both hard and soft tissues around the implant with a good esthetic outcome in all the follow up visits. Integrating immediate placement with stable implant-abutment connection, platform switching concept and careful case selection, we can achieve a very good esthetic outcome.

  12. Analysis of tissue neogenesis in extraction sockets treated with guided bone regeneration: clinical, histologic, and micro-CT results.

    Science.gov (United States)

    Neiva, Rodrigo; Pagni, Giorgio; Duarte, Frederico; Park, Chan Ho; Yi, Erica; Holman, Lindsay A; Giannobile, William V

    2011-01-01

    The aims of this article were to perform a detailed evaluation of the healing of extraction sockets covered with a resorbable collagen membrane 12 weeks following exodontia and to determine if this device had ossifying properties. Ten consecutive subjects in need of extraction of maxillary premolars were recruited. Each subject had a hopeless maxillary premolar extracted with minimal trauma. Sockets were then covered with a collagen barrier membrane alone. At 12 weeks, reentry surgery was performed, clinical measurements were repeated, and bone core biopsies were obtained prior to dental implant placement for histologic and microcomputed tomography (micro-CT) analysis. Study sites showed mean bone regeneration horizontally of 7.7 mm (buccopalatally) and 4.6 mm (mesiodistally). Vertical bone repair showed a mean gain of 10.9 mm. Subtraction radiography showed a mean apical shift of the crestal bone at the center of the socket of 2.1 mm (range, 0.7 to 4.3 mm). Micro-CT and histology revealed formation of well-mineralized tissue at 12 weeks, with a mean percentage of vital bone of 45.87% ± 12.35%. No signs of membrane ossification were observed. A detailed analysis of tissue neogenesis in extraction sites protected by this barrier membrane has demonstrated that adequate bone formation for implant placement occurs as early as 12 weeks following exodontia, with minimal changes in alveolar ridge dimensions. No evidence of membrane ossification was observed.

  13. Rock Characteristics and Ball Mill Energy Requirements at ...

    African Journals Online (AJOL)

    Michael

    2015-06-01

    Jun 1, 2015 ... rate, power draw and ball mill performance. The rock types identified were conglomerate and quartzite and the main minerals were quartz, feldspars, iron oxides and sulphides. Mineralogical analysis classified the ores into hard, medium and soft. There were little differences in the mineral constituents of the ...

  14. Differential effects of thermal and chemical stressors on tissue balls ...

    African Journals Online (AJOL)

    Coral cell aggregates (tissue balls) from four species (Acropora muricata, Fungia repanda, Pavona cactus and Pocillopora damicornis) were used as an indicator to investigate the effects on the corals of thermal stress and of chemical extracts from three sponges (Adocia sp., Haliclona sp. and Lissodendoryx sp.) and one ...

  15. Clinical and biometrical evaluation of socket preservation using demineralized freeze-dried bone allograft with and without the palatal connective tissue as a biologic membrane.

    Science.gov (United States)

    Moghaddas, Hamid; Amjadi, Mohammad Reza; Naghsh, Narges

    2012-11-01

    Alveolar ridge preservation following tooth extraction has the ability to maintain the ridge dimensions and allow the implant placement in an ideal position fulfilling both functional and aesthetic results. The aim of this study was to evaluate the efficacy of the palatal connective tissue as a biological membrane for socket preservation with demineralized freeze-dried bone allograft (DFDBA). Twelve extraction sites were treated with DFDBA with (case group) and without (control group) using autogenous palatal connective tissue membrane before placement of implants. Alveolar width and height, amount of keratinized tissue, and gingival level were measured at pre-determined points using a surgical stent at two times, the time of socket preservation surgery. In both groups a decrease in all socket dimensions was found. The average decrease in socket width, height, keratinized tissue, and gingival level in case group was 1.16, 0.72, 3.58, and 1.27 mm, and in control group was 2.08, 0.86, 4.52, and 1.58 mm respectively. Statistical analysis showed that decrease in socket width (P = 0.012), keratinized tissue (P ≤ 0.001), and gingival level (P = 0.031) in case group was significantly lower than that of the control group. Results showed no meaningful difference in socket height changes when compared with case and control groups (P = 0.148). Under the limits of this study, connective tissue membrane could preserve socket width, amount of keratinized tissue, and the gingival level more effectively than DFDBA alone.

  16. The prototype of a thermoregulatory system for measurement and control of temperature inside prosthetic socket.

    Science.gov (United States)

    Ghoseiri, Kamiar; Zheng, Yong Ping; Hing, Louis Lee Tat; Safari, Mohammad Reza; Leung, Aaron Kl

    2016-12-01

    Thermal related problems with prostheses are common complaints of amputee people. This article aims to introduce a thermoregulatory technique as a potential solution for those problems in prostheses wearers. A smart thermoregulatory system was designed, manufactured, and installed on a phantom model of a prosthetic socket. It captured temperature data from 16 sensors positioned at the interface between the phantom model and a silicone liner and used their average for comparison with a defined set temperature to select required heating or cooling functions for thermal equilibrium. A thin layer of Aluminum was used to transfer temperature between thermal pump and different sites around the phantom model. The feasibility of this thermoregulatory technique was confirmed by its ability to provide thermal equilibrium. Further investigations to improve the design of thermoregulatory system are necessary including temperature transfer element and power consumption based on thermal capacity and thermal inertia of the residual limb. The smart thermoregulatory system by providing thermal equilibrium between two sides of a prosthetic silicone liner can control residual limb skin temperature and sweating. Consequently, it can improve quality of life in amputee people. © The International Society for Prosthetics and Orthotics 2015.

  17. Structural and magnetic properties of ball milled copper ferrite

    DEFF Research Database (Denmark)

    Goya, G.F.; Rechenberg, H.R.; Jiang, Jianzhong

    1998-01-01

    The structural and magnetic evolution in copper ferrite (CuFe2O4) caused by high-energy ball milling are investigated by x-ray diffraction, Mössbauer spectroscopy, and magnetization measurements. Initially, the milling process reduces the average grain size of CuFe2O4 to about 6 nm and induces ca...

  18. Development of Stick and Ball Sports on Gateball

    Directory of Open Access Journals (Sweden)

    Indriyanti

    2017-10-01

    Full Text Available The purpose of this research is to make product design development of stick and ball sports in gateball. The approach used in this study is a method of Research and Development. The subject of this research is the Central Java on gateball club event gateball in Semarang and Yogyakarta. Experts and expert expert gateball expert in mechanical engineering. The data analysis phase the work field, and the data analysis stage include observation, observation, interviews, and documentation of the test kefektifan products, expert judgment expert expert gateball and expert mechanical engineering expert. The results of this research are stick and ball exercise for beginner players gateball gateball. The result of the validator 3 expert expert from the expert gateball and expert mechanical engineering product validation data beginning the first phase obtained a score above 73 definitions of the criteria of “good”, on the second stage of the product validation data obtained a score above the 81 criteria for “excellent”. The results of the interviews to the development of gateball players 19 stick and ball gateball can not be used to play in a match and can be used for subsequent exercises but for beginners a product development tool model stick and ball gateball “ INC. “can be used to enhance the ability of basic techniques in motion game for players, gateball.

  19. A combined kinematic and kinetic analysis at the residuum/socket interface of a knee-disarticulation amputee.

    Science.gov (United States)

    Tang, Jinghua; McGrath, Michael; Hale, Nick; Jiang, Liudi; Bader, Dan; Laszczak, Piotr; Moser, David; Zahedi, Saeed

    2017-11-01

    The bespoke interface between a lower limb residuum and a prosthetic socket is critical for an amputee's comfort and overall rehabilitation outcomes. Analysis of interface kinematics and kinetics is important to gain full understanding of the interface biomechanics, which could aid clinical socket fit, rehabilitation and amputee care. This pilot study aims to investigate the dynamic correlation between kinematic movement and kinetic stresses at the interface during walking tests on different terrains. One male, knee disarticulation amputee participated in the study. He was asked to walk on both a level surface and a 5° ramped surface. The movement between the residuum and the socket was evaluated by the angular and axial couplings, based on the outputs from a 3D motion capture system. The corresponding kinetic stresses at anterior-proximal (AP), posterior-proximal (PP) and anterior-distal (AD) locations of the residuum were measured, using individual stress sensors. Approximately 8° of angular coupling and up to 32 mm of axial coupling were measured when walking on different terrains. The direction of the angular coupling shows strong correlation with the pressure difference between the PP and AP sensors. Higher pressure was obtained at the PP location than the AP location during stance phase, associated with the direction of the angular coupling. A strong correlation between axial coupling length, L, and longitudinal shear was also evident at the PP and AD locations i.e. the shortening of L corresponds to the increase of shear in the proximal direction. Although different terrains did not affect these correlations in principle, interface kinematic and kinetic values suggested that gait changes can induce modifications to the interface biomechanics. It is envisaged that the reported techniques could be potentially used to provide combined kinematics and kinetics for the understanding of biomechanics at the residuum/socket interface, which may play an important

  20. Ball milling and annealing of Co-50 at% W Powders

    CSIR Research Space (South Africa)

    Bolokang, AS

    2013-04-01

    Full Text Available annealing of unmilled compacts yielded metastable phases. Upon 10 and 20 h ball milling of Co-W powder, no alloying was obtained. Although milling did not yield significant crystal changes in W and Co ground state struc- tures, its effect is evident during...

  1. 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.

  2. THE EFFECT OF GAMES AND TRAINING PROGRAMS OFFERED AT BALL SCHOOL (BALSCHULE, ON BALL-COORDINATION AMONG FIRST AND SECOND GRADE STUDENTS

    Directory of Open Access Journals (Sweden)

    Behrooz Ebrahimi

    2013-06-01

    Full Text Available The aim of this study is to investigate the effect of games and training programs offered at the Ball school (Ballschule Heidelberg, on ball-coordination among first and second grade students. For this purpose, 38 students from 13 schools covered by the Ball school (Heidelberg Balschule, were chosen as the experimental group (non-random ; in the meantime the consent of the students’ parents were also received. Forty students as well as a control group (non-random of eight normal schools were selected with parental consents. Then through using ball-coordination tests [BKT (BallKoordinationstests. Ball Coordination’s Tests], the level of the ball skills among both groups were measured in the pre-test and Post-test. Tests included kicking ball against the wall (under five conditions. The research methods were semi-experimental with experimental and control groups. Independent variables were also applied to the experimental group and the means and standard deviations were calculated through descriptive statistics. And then, a T-test for statistical analysis of data in related groups were applied. The results showed a significant effect of games and training programs offered at the school ball in the ball-coordination of subjects.

  3. Development of Microcontroller-Based Ball and Beam Trainer Kit

    Directory of Open Access Journals (Sweden)

    Gunawan Dewantoro

    2015-03-01

    Full Text Available Normal 0 false false false EN-US X-NONE X-NONE A ball and beam trainer kit based on microcontroller was developed for teaching control system course for the sophomore students. This specially-purposed kit consists of a ball located on a beam with a fixed axle at one of its end. At the other end, a servomotor was employed to control the position of the ball by adjusting the rotation angle of the servomotor. Seven predetermined positions were set to 10, 20, 30, 40, 50, 60, and 70 cm relative to the fixed axle of the beam. The Proportional-Integral-Derivative (PID scheme was then used to compensate the error. This kit is equipped with a user interface to configure controller coefficients, select the set points, plot the actual ball position, and display parameter values. The user interface program runs on PC or notebook connected to microcontroller via serial communications. A questionnaire-based assessment about the use of this kit was conducted by 17 students taking the course, giving a rating value of 94.12%.

  4. 27 CFR 25.293 - Record of ballings and alcohol content.

    Science.gov (United States)

    2010-04-01

    ... TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS BEER Records and Reports § 25.293 Record of ballings... the ballings and the alcohol content of beer and cereal beverage transferred for bottling and racking, between breweries in bulk conveyances, and to pilot brewing plants. Records showing ballings and alcohol...

  5. Calcium dynamics in the healing of tooth extraction sockets in mice evaluated using 45Ca-autoradiography and Electron Probe Micro Analysis

    International Nuclear Information System (INIS)

    Tanaka, Takeo

    2006-01-01

    The calcium distribution in tooth extraction sockets of mice was examined using 45-Calcium autoradiography (ARG) and Electron Probe Micro Analysis (EPMA). Mice were divided into 8 groups (n=8) according to the number of days (1, 2, 3, 4, 5, 7, 10, 20 respectively) after extraction. Frozen sections were taken from mice on each experimental day after injection of 45-Calcium (RI). The process of formation of new bone was observed using ARG. An ultimate analysis was performed by EPMA. Histological analysis was performed with toluidine blue- and alizarin red S-staining. In toluidine blue-staining, an osteoblast was found along the socket wall at 4 days and non-calcified periodontal ligament was recognized until 5 days after extraction. In alizarin red S-staining, new bone was recognized separated from the socket wall at 4 days after extraction. 45 Ca-labeling was detected strongly in the periosteum of the mandible, the surface of cement and periodontal ligament in control animals. 45 Ca-labeling was moved from the bottom to the top of the tooth extraction socket during the period from 1 to 5 days after extraction, but in the periodontal ligament lower than in the granulation tissue. 45 Ca-labeling was detected in the socket at 7, 10 and 20 days. At 4 days, calcium phosphate was observed in the central portion of the socket using EPMA. 45 Ca-labeling showed deposition of calcium phosphate for alveolar bone and new bone. These results suggest that the granulation tissue may be involved in the initial calcification in the tooth extraction socket and lead to the formation of new bone in it. (author)

  6. 78 FR 9674 - Ball Bearings and Parts Thereof From Germany: Preliminary Results of Antidumping Duty...

    Science.gov (United States)

    2013-02-11

    ... DEPARTMENT OF COMMERCE International Trade Administration [A-428-801] Ball Bearings and Parts... antidumping duty order on ball bearings and parts thereof from Germany. The period of review (POR) is May 1... at less than normal value. \\1\\ On September 15, 2011, the Department revoked the order on ball...

  7. The information for catching fly balls : Judging and intercepting virtual balls in a CAVE

    NARCIS (Netherlands)

    Zaal, FTJM; Michaels, CF

    Visually guided action implies the existence of information as well as a control law relating that information to movement. For ball catching, the Chapman Strategy-keeping constant the rate of change of the tangent of the elevation angle (d(tan(alpha))/dt)-leads a catcher to the right location at

  8. The information for catching fly balls: judging and intercepting virtual balls in a CAVE

    NARCIS (Netherlands)

    Zaal, F.T.J.M.; Michaels, C.F.

    2003-01-01

    Visually guided action implies the existence of information as well as a control law relating that information to movement. For ball catching, the Chapman Strategy - keeping constant the rate of change of the tangent of the elevation angle (d(tan(α))/dt) - leads a catcher to the right location at

  9. Healing of extraction sockets and augmented alveolar defects following 1-year treatment with bisphosphonate.

    Science.gov (United States)

    Khojasteh, Arash; Behnia, Hossein; Morad, Golnaz; Dashti, Seyedeh Ghazaleh; Dehghan, Mohammad Mehdi; Shahab, Shahriyar; Abbas, Fatemeh Mashhadi

    2013-01-01

    To assess the effect of bisphosphonates on healing of extraction sockets and augmented alveolar defects, 12 adult female mongrel dogs were assigned to 2 experimental groups and a control group. The experimental groups received oral alendronate (ALN, 3.5 mg/kg/wk) or IV pamidronate (PAM, 1 mg/kg/wk) for 12 months. Animals were randomly tested for serum C-terminal telopeptide of collagen I (CTx). The right first and second premolars were extracted. After 8 weeks, extraction sites were evaluated for healing. Subsequently, 3-wall defects were created in ridges and filled with human mineralized cortical particulate bone. Two months post-augmentation, animals were sacrificed and mandibles were collected for cone-beam computed tomography (CBCT) and histomorphometric appraisal. The obtained data were compared using 1-way ANOVA test. CTx test results in both experimental groups were comparable (alveolar bone in the PAM group and the upper rim of the alveoli in the ALN group. Histologically, bone sequestra from the PAM group demonstrated empty osteocyte lacunae, while in the ALN group areas of necrotic bone along with evidence of active bone remodeling was distinguished. Eight weeks post-augmentation, the experimental groups showed no evidence of bone formation in the augmented area, while bone formation ratio was measured to be 18.32% in the control group. The mean amount of pixel intensity calculated from the CBCT images of the ALN, PAM, and control group was 113.69 ± 11.04, 124.94 ± 4.72, and 113.69 ± 6.63, respectively. Pixel intensity in PAM-treated group was significantly higher than both other groups. This study demonstrated that 1-year treatment with ALN/PAM was associated with impairment of post-extraction and post-augmentation bone healing in dogs.

  10. Sir Robert Ball: Victorian Astronomer and Lecturer par excellence

    Science.gov (United States)

    Jones, R. I. G.

    2005-12-01

    Between 1875 and 1910 Sir Robert Stawell Ball gave an estimated 2,500 lectures in towns and cities all over the British Isles and abroad. This paper traces his lecturing career from its beginnings in Ireland to the triumphs of the Royal Institution, and on lecture tours in the United States of America. After a period in mathematics and mechanics, he became a populariser of science, especially astronomy, and found fame and fortune among the working classes and the aristocracy. What motivated him to tireless travels is uncertain, but it might have been that it was rewarding, financially and to his reputation. Whatever his motives, contemporary accounts are clear that BallÕs lectures were extremely popular and well-received.

  11. Tracking of Ball and Players in Beach Volleyball Videos

    OpenAIRE

    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, respec...

  12. Human Histologic Evidence of New Bone Formation and Osseointegration Between Root Dentin (Unplanned Socket-Shield) and Dental Implant: Case Report.

    Science.gov (United States)

    Schwimer, Charles; Pette, Gregory A; Gluckman, Howard; Salama, Maurice; Du Toit, Jonathan

    The socket-shield technique described 7 years ago has since grown in its reporting in the literature as a valid method of ridge preservation at immediate implant placement. To date, large clinical cohorts with up-to-4-year follow-up have been reported. Additionally, evidence of tissue histology at the dental implant and socket-shield has been demonstrated in the animal model. However, human histologic evidence has not yet been available, and the clinician's uncertainty regarding the tissues that may form between the socket-shield and dental implant may remain unanswered until now. This case report presents the first human histologic evidence that bone may entirely fill the space between root dentin and an osseointegrated implant surface.

  13. Surgical Protocol and Short-Term Clinical Outcome of Immediate Placement in Molar Extraction Sockets Using a Wide Body Implant

    Science.gov (United States)

    Vandeweghe, Stefan; Hattingh, André; Wennerberg, Ann

    2011-01-01

    ABSTRACT Objectives Implant placement in molar extraction sockets can be difficult due to complex multi-root anatomy and the lack of predictable primary stability. The aim of this study was to evaluate the outcome of an 8 - 9 mm diameter tapered implant, designed to be placed in molar extraction sockets. Material and methods Patients treated at least 1 year before with a Max® implant (Southern Implants, Irene, South Africa) were invited for a clinical examination. Variables collected were surgical and prosthetic protocol, implant dimension and smoking habits. Peri-implant bone level was determined on peri-apical radiographs and compared to baseline, being implant insertion. Results 98 implants had been placed in 89 patients. One implant had failed. Thirty eight patients representing 47 implants (maxilla 26, mandible 21) were available for clinical examination. Mean bone loss was 0.38 mm (SD 0.48; range - 0.50 – 1.95) after a mean follow-up of 20 months (range 12 - 35). Implant success was 97.9%. Around 30 implants, a bone substitute was used to fill the residual space, but this did not affect the bone loss outcome. Bone loss was only significantly different between maxilla and mandible (0.48 mm vs. 0.27 mm) and between the 8 and 9 mm diameter implants (0.23 mm vs. 0.55 mm). A full papilla was present at 71% of the interproximal sites and irrespective of bone loss. Conclusions The Max® implant demonstrated good primary stability, when placed in molar extraction sockets, with limited bone loss over time. PMID:24421993

  14. Surgical Protocol and Short-Term Clinical Outcome of Immediate Placement in Molar Extraction Sockets Using a Wide Body Implant

    Directory of Open Access Journals (Sweden)

    Stefan Vandeweghe

    2011-08-01

    Full Text Available Objectives: Implant placement in molar extraction sockets can be difficult due to complex multi-root anatomy and the lack of predictable primary stability. The aim of this study was to evaluate the outcome of an 8 - 9 mm diameter tapered implant, designed to be placed in molar extraction sockets.Material and methods: Patients treated at least 1 year before with a Max® implant (Southern Implants, Irene, South Africa were invited for a clinical examination. Variables collected were surgical and prosthetic protocol, implant dimension and smoking habits. Peri-implant bone level was determined on peri-apical radiographs and compared to baseline, being implant insertion.Results: 98 implants had been placed in 89 patients. One implant had failed. Thirty eight patients representing 47 implants (maxilla 26, mandible 21 were available for clinical examination. Mean bone loss was 0.38 mm (SD 0.48; range - 0.50 – 1.95 after a mean follow-up of 20 months (range 12 - 35. Implant success was 97.9%. Around 30 implants, a bone substitute was used to fill the residual space, but this did not affect the bone loss outcome. Bone loss was only significantly different between maxilla and mandible (0.48 mm vs. 0.27 mm and between the 8 and 9 mm diameter implants (0.23 mm vs. 0.55 mm. A full papilla was present at 71% of the interproximal sites and irrespective of bone loss.Conclusions: The Max® implant demonstrated good primary stability, when placed in molar extraction sockets, with limited bone loss over time.

  15. The use of Osseointegration and Orbital Implants in the Management of Orbital Exenteration or Severe Contracted Sockets

    Directory of Open Access Journals (Sweden)

    Emine Esra Karaca

    2014-03-01

    Full Text Available Objectives: To evaluate the results of bony integrated implants used in the management of exenterated or contracted sockets. Materials and Methods: Ten eyes of 10 cases underwent bony integrated implants for the management of exenterated (7 eyes or contracted (3 eyes sockets. The procedure was performed in two steps in a two-month period. The first step included placement of screws by preparing the osteotomy site, whereas the second step included implantation of magnetic implants over these screws that will adhere to the orbital implant. The patients were retrospectively evaluated for age, gender, etiology, surgical timing, history of radiotherapy, and time of application of epithesis. The presence of infection at the surgical site, implant loss, functional or cosmetic problems at the perisurgical area, the usage of epithesis during the social life were evaluated. Results: There were 7 female and 3 male patients. The mean age was 34 (5-75 years. The indications for enucleation or exenteration were: retinoblastoma (4 cases, malignant melanoma (2 cases, basal cell carcinoma (1 case, squamous cell carcinoma (1 case, rhabdomyosarcoma (1 case and sinoorbital mucormycosis (1 case. The epitheses were applied 3 to 156 months (mean 51 months following the intervention. All of the implantations were performed successfully. During follow-up, one case had lost the implant and one case had local infection that responded to antibiotic treatment. Three cases were reoperated and the implants were replaced after a 2-year follow-up time due to the deterioration of the magnetic effect of the implants. Conclusion: Bony integrated orbital implants have an important role in solution of esthetic problems encountered in the exenterated orbit and severe contracted socket. (Turk J Ophthalmol 2014; 44: 127-31

  16. Web-based control application using WebSocket

    International Nuclear Information System (INIS)

    Furukawa, Y.

    2012-01-01

    The WebSocket allows asynchronous full-duplex communication between a Web-based (i.e. Java Script-based) application and a Web-server. WebSocket started as a part of HTML5 standardization but has now been separated from HTML5 and has been developed independently. Using WebSocket, it becomes easy to develop platform independent presentation layer applications for accelerator and beamline control software. In addition, a Web browser is the only application program that needs to be installed on client computer. The WebSocket-based applications communicate with the WebSocket server using simple text-based messages, so WebSocket is applicable message-based control system like MADOCA, which was developed for the SPring-8 control system. A simple WebSocket server for the MADOCA control system and a simple motor control application were successfully made as a first trial of the WebSocket control application. Using Google-Chrome (version 13.0) on Debian/Linux and Windows 7, Opera (version 11.0) on Debian/Linux and Safari (version 5.0.3) on Mac OS X as clients, the motors can be controlled using a WebSocket-based Web-application. Diffractometer control application use in synchrotron radiation diffraction experiment was also developed. (author)

  17. Effects of low-level laser therapy on orthodontic tooth movement and root resorption after artificial socket preservation

    Science.gov (United States)

    Seifi, Massoud; Atri, Faezeh; Yazdani, Mohammad Masoud

    2014-01-01

    Background: Low- level laser therapy has been used to stimulate the orthodontic tooth movements (OTM) previously. Furthermore, in the orthodontic treatments accompanying tooth extractions, the adjacent teeth move towards the extraction sites and close the space in some cases. Then, the adjacent tooth movements must be prevented in the treatments requiring space. Laser stimulates and at some doses decelerates tooth movement; it also improves healing process and enhances osteogenesis. Hence, it can prevent movement by osteogenesis adjacent to the tooth. The present study investigated the effects of low-level laser therapy on the OTM and root resorption following artificial socket preservation. Materials and Methods: In this experimental animal trial, 16 male albino rabbits were selected with similar characteristics and randomly divided in two groups. Under general anesthesia, an artificial socket, 8 mm in height, was created in the mesial aspect of the first premolars of the rabbits and filled with demineralized freeze dried bone allograft (DFDBA). The first premolars were connected to the incisors using nickel titanium coil springs. In experimental group, gallium-aluminum-arsenide (GaAlAs) laser was irritated mesial to first premolar where artificial socket was created continuously (808 nm). The cycle was 10 days irritation, 14 days rest, 10 days irritation, 14 days rest (Biostimulation mode). Control group was not laser irradiated. All animals were sacrificed after 48 days and the distance between the distal aspect of the first premolars, and the mesial surface of the second premolars was measured with leaf gauge. The specimens underwent histological assessments. Integrity of root and its resorption was observed under microscope calibration. The size of resorption lacunae was calculated in mm2. Normality of data was proved according to Kolmogorov-Smirnov analysis, and Student's t-test was done. P value less than 0.05 was considered as significant. Results: The mean

  18. Effects of low-level laser therapy on orthodontic tooth movement and root resorption after artificial socket preservation

    Directory of Open Access Journals (Sweden)

    Massoud Seifi

    2014-01-01

    Full Text Available Background: Low- level laser therapy has been used to stimulate the orthodontic tooth movements (OTM previously. Furthermore, in the orthodontic treatments accompanying tooth extractions, the adjacent teeth move towards the extraction sites and close the space in some cases. Then, the adjacent tooth movements must be prevented in the treatments requiring space. Laser stimulates and at some doses decelerates tooth movement; it also improves healing process and enhances osteogenesis. Hence, it can prevent movement by osteogenesis adjacent to the tooth. The present study investigated the effects of low-level laser therapy on the OTM and root resorption following artificial socket preservation. Materials and Methods: In this experimental animal trial, 16 male albino rabbits were selected with similar characteristics and randomly divided in two groups. Under general anesthesia, an artificial socket, 8 mm in height, was created in the mesial aspect of the first premolars of the rabbits and filled with demineralized freeze dried bone allograft (DFDBA. The first premolars were connected to the incisors using nickel titanium coil springs. In experimental group, gallium-aluminum-arsenide (GaAlAs laser was irritated mesial to first premolar where artificial socket was created continuously (808 nm. The cycle was 10 days irritation, 14 days rest, 10 days irritation, 14 days rest (Biostimulation mode. Control group was not laser irradiated. All animals were sacrificed after 48 days and the distance between the distal aspect of the first premolars, and the mesial surface of the second premolars was measured with leaf gauge. The specimens underwent histological assessments. Integrity of root and its resorption was observed under microscope calibration. The size of resorption lacunae was calculated in mm 2 . Normality of data was proved according to Kolmogorov-Smirnov analysis, and Student′s t-test was done. P value less than 0.05 was considered as significant

  19. Effects of low-level laser therapy on orthodontic tooth movement and root resorption after artificial socket preservation.

    Science.gov (United States)

    Seifi, Massoud; Atri, Faezeh; Yazdani, Mohammad Masoud

    2014-01-01

    Low- level laser therapy has been used to stimulate the orthodontic tooth movements (OTM) previously. Furthermore, in the orthodontic treatments accompanying tooth extractions, the adjacent teeth move towards the extraction sites and close the space in some cases. Then, the adjacent tooth movements must be prevented in the treatments requiring space. Laser stimulates and at some doses decelerates tooth movement; it also improves healing process and enhances osteogenesis. Hence, it can prevent movement by osteogenesis adjacent to the tooth. The present study investigated the effects of low-level laser therapy on the OTM and root resorption following artificial socket preservation. In this experimental animal trial, 16 male albino rabbits were selected with similar characteristics and randomly divided in two groups. Under general anesthesia, an artificial socket, 8 mm in height, was created in the mesial aspect of the first premolars of the rabbits and filled with demineralized freeze dried bone allograft (DFDBA). The first premolars were connected to the incisors using nickel titanium coil springs. In experimental group, gallium-aluminum-arsenide (GaAlAs) laser was irritated mesial to first premolar where artificial socket was created continuously (808 nm). The cycle was 10 days irritation, 14 days rest, 10 days irritation, 14 days rest (Biostimulation mode). Control group was not laser irradiated. All animals were sacrificed after 48 days and the distance between the distal aspect of the first premolars, and the mesial surface of the second premolars was measured with leaf gauge. The specimens underwent histological assessments. Integrity of root and its resorption was observed under microscope calibration. The size of resorption lacunae was calculated in mm(2). Normality of data was proved according to Kolmogorov-Smirnov analysis, and Student's t-test was done. P value less than 0.05 was considered as significant. The mean OTM were 5.68 ± 1.21 mm in the control

  20. Observation of the Optical and Spectral Characteristics of Ball Lightning

    Science.gov (United States)

    Cen, Jianyong; Yuan, Ping; Xue, Simin

    2014-01-01

    Ball lightning (BL) has been observed with two slitless spectrographs at a distance of 0.9 km. The BL is generated by a cloud-to-ground lightning strike. It moves horizontally during the luminous duration. The evolution of size, color, and light intensity is reported in detail. The spectral analysis indicates that the radiation from soil elements is present for the entire lifetime of the BL.

  1. 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)

  2. Alveolar ridge dimensional changes following ridge preservation procedure using SocketKAP(™) : exploratory study of serial cone-beam computed tomography and histologic analysis in canine model.

    Science.gov (United States)

    Ryu, Kyung-Ho; Min, Seiko; You, Hyung-Keun; Sin, Yeon-Woo; Lee, Wan; Lee, Jun; Kiss, Alex; Almohaimeed, Mohammad; Zadeh, Homayoun H

    2016-09-01

    The aim of this pilot study was to examine the kinetics of alterations in alveolar ridge width and height following tooth extraction with and without ridge preservation, using anorganic bovine bone mineral (ABBM) and a novel device (SocketKAP(™) ) designed for obturation of socket orifice. Maxillary left and right PM1 and mandibular right PM2 and PM4 were extracted on six beagle dogs and treated as follows: Group A: negative control; Group B: SocketKAP(™) alone; Group C: ABBM + SocketKAP(™) . Serial cone-beam computed tomography (CBCT) was taken at 0-, 1-, 2-, 4-, 8- and 12-week intervals to calculate the rate of alveolar bone loss, followed by histologic and histomorphometric analyses at 12 weeks. Across group outcomes were compared. Without additional intervention, the crestal-most 3 mm of alveolar bone width lost approximately 0.21-0.28 mm per week. The rate of alveolar buccal bone height loss was 0.19 mm per week. Comparatively, in group C, the alveolar bone was relatively stable, with loss of only 0.003-0.13 mm of width and 0.12 mm of height per week. These differences were statistically significant. The alveolar bone in sites treated by SocketKAP(™) alone was significantly different from control only at select time points and locations of the ridge, presumably due to small sample size. Without additional intervention, tooth extraction was accompanied by rapid loss of alveolar ridge width and height. Applications of SocketKAP(™) and ABBM were effective in reducing alveolar crestal width and height loss following tooth extraction. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  3. Socket seal surgery: Clinical uses in implant dentistry and guided bone regeneration procedures for single tooth replacement in the esthetic zone.

    Science.gov (United States)

    Negri, Bruno; Zuhr, Otto; Fickl, Stefan; Ciurana, Xavier Rodríguez; Navarro Martínez, José Manuel; Blanco, Víctor Méndez

    2016-02-01

    Restoring failing anterior teeth with a dental implant is considered a complex treatment even with thorough biologic knowledge of the situation. The goal is to produce a result in which the labial soft tissues and the papillae remain stable over time. Treatment of the fresh extraction socket in the alveolar ridge presents a challenge in everyday clinical practice. Regardless of the subsequent treatment, maintenance of the ridge contour will frequently facilitate all further therapeutic steps. Socket seal surgery and socket preservation in combination with immediate, early, or delayed implant placement can be valuable procedures for single tooth replacement. However, their potential as ridge preservation techniques in these different situations still needs to be demonstrated. The use of these procedures is illustrated in three consecutive cases.

  4. Ultrasonic friction power during thermosonic Au and Cu ball bonding

    International Nuclear Information System (INIS)

    Shah, A; Mayer, M; Zhou, Y; Qin, I; Huynh, C; Meyer, M

    2010-01-01

    The ultrasonic friction power during thermosonic ball bonding with Au and Cu wires, both 25 μm in diameter, is derived with an improved method from experimental measurements during the bonding process. Experimental data include the current delivered to the ultrasonic transducer and the tangential force measured using piezoresistive microsensors integrated close to the Al bonding pad. The improvement results from a new, more accurate method to derive the mechanical compliance of the ultrasonic system. The method employs a bond process modification in which the ultrasonic current is ramped up sequentially in three steps. In the first two steps, the ultrasonic current is set to levels that are too low to cause sliding. The bonding takes place during the third step, when the current is ramped up to the optimum value required for making good quality bonds. The ultrasonic compliance values are derived from the first two steps and are 8.2 ± 0.5 μm N -1 and 7.7 ± 0.5 μm N -1 for the Au and Cu processes, respectively. These values are determined within an average error estimate of ±6%, substantially lower than the ±10% estimated with a previously reported method. The ultrasonic compliance in the case of Au is 6% higher due to the lower elastic modulus of Au compared with that of Cu. Typical maximum values of relative sliding amplitude of ultrasonic friction at the interface are 655 nm and 766 nm for the Au and Cu processes. These values are 81% of the free-air vibration amplitude of the bonding capillary tip for the respective ultrasonic current settings. Due to bond growth, which damps relative motion between the ball and the pad, the final relative amplitude at the bond interface is reduced to 4% of the equivalent free-air amplitude. Even though the maximum value of relative amplitude is 17% higher in the Cu process compared with the Au process, the average total interfacial sliding is 519 μm in the Cu process, which is 31% lower than that in the Au process (759

  5. Effect of mangosteen peel extract combined with demineralized freezed-dried bovine bone xenograft on osteoblast and osteoclast formation in post tooth extraction socket

    Directory of Open Access Journals (Sweden)

    Utari Kresnoadi

    2016-12-01

    Full Text Available Background: Tooth extraction, a common procedure in dentistry, can cause bone resorption during socket healing. Therefore, it is important to perform socket preservation procedure to maintain alveolar bone. Providing a combination of mangosteen peel extract with demineralized freezed-dried bovine bone xenograft (DFDBBX in tooth extraction socket was expected to accelerate alveol bone formation. Purpose: This study aims to determine the effect of mangosteen peel extract combined with DFDBBX introduced into the socket of post tooth extraction on the formation of osteoblasts and osteoclasts. Method: Twenty-eight (28 Cavia cobayas were divided into four groups. Extraction to the lower left incisor of Cavia cobaya was performed. The extraction socket was filled with 25 gram of PEG (group I as a control, active materials consisted of mangosteen peel extract and DFDBBX 0.5% (group II, active materials consisted of mangosteen peel extract and DFDBBX 1% (group III, and active materials consisted of mangosteen peel extract and DFDBBX 2% (group IV. After thirty days, those Cavia cobayas were sacrificed. By using HE on Histopatological examination, the number of osteoblasts and osteoclasts were measured by light microscope with 400 times of magnification. The statistical analysis was then performed using oneway Anova & TukeyHSD test. Result: The component active materials consisted of mangosteen peel extract and DFDBBX 2% had the most significant results related to the formation of osteoblasts and osteoclasts. Conclusion: Mangosteen peel extract combined with DFDBBX can increase osteoblasts and decrease osteoclasts in the socket of tooth extraction in Cavia cobaya. The combination of mangosteen peel extract and DFDBBX 2% is the most effective material in increasing osteoblast and decreasing osteoclast.

  6. Interrelation between ball lightning and optically induced forces

    Science.gov (United States)

    Torchigin, V. P.; Torchigin, A. V.

    2013-09-01

    Optically induced forces are considered as a key factor for explaining the phenomenon of ball lightning. They can provide not only the existence of ball lightning in the form of self-confined intense white light circulating in a spherical shell of air strongly compressed by the light but also the anomalous motion of ball lightning in the terrestrial atmosphere.

  7. The use of a direct manufacturing prosthetic socket system in a rural community in South Africa: A pilot study and lessons for future research.

    Science.gov (United States)

    Ennion, Liezel; Johannesson, Anton; Rhoda, Anthea

    2017-10-01

    Challenges exist with the provision of appropriate mobility assistive devices in rural areas. The use of the direct manufacturing prosthetic socket system is a possible solution to these challenges. The objective of this study was to test and explore the clients' perspectives with the application of this device. Within a mixed-methods approach, a longitudinal sequential explanatory design was applied. The Orthotic and Prosthetic User's Survey was administered to explore the use of the direct manufacturing prosthetic socket system in terms of function, health-related quality of life and client satisfaction. A conveniently selected sample of 21 individuals who suffered a unilateral trans-tibial amputation was included. Data were collected at 1, 3 and 6 months post fitting, and two focus group discussions were also administered. Of the 21 participants recruited, 11 returned for follow up. Although participants reported favourably about the prosthesis, their scores were generally worse than the norms with regard to function and quality of life. Participants highlighted the need for improvement in the cosmetic appearance of the prosthesis. The direct manufacturing prosthetic socket system could be considered as an alternative technique of socket manufacturing for individuals living in rural areas due to the shorter manufacture time and promising initial results, but further research on this topic with a bigger sample is recommended. Clinical relevance The direct manufacturing prosthetic socket system may be considered as an alternative to the traditional prosthetic socket manufacturing technique used in South Africa. As this device requires only one visit and therefore decreased travel by the patients to the hospitals, it could be applicable to more amputees who cannot return to hospital post discharge.

  8. Computer-socket manufacturing error: How much before it is clinically apparent?

    Science.gov (United States)

    Sanders, Joan E.; Severance, Michael R.; Allyn, Kathryn J.

    2015-01-01

    The purpose of this research was to pursue quality standards for computer-manufacturing of prosthetic sockets for people with transtibial limb loss. Thirty-three duplicates of study participants’ normally used sockets were fabricated using central fabrication facilities. Socket-manufacturing errors were compared with clinical assessments of socket fit. Of the 33 sockets tested, 23 were deemed clinically to need modification. All 13 sockets with mean radial error (MRE) greater than 0.25 mm were clinically unacceptable, and 11 of those were deemed in need of sizing reduction. Of the remaining 20 sockets, 5 sockets with interquartile range (IQR) greater than 0.40 mm were deemed globally or regionally oversized and in need of modification. Of the remaining 15 sockets, 5 sockets with closed contours of elevated surface normal angle error (SNAE) were deemed clinically to need shape modification at those closed contour locations. The remaining 10 sockets were deemed clinically acceptable and not in need modification. MRE, IQR, and SNAE may serve as effective metrics to characterize quality of computer-manufactured prosthetic sockets, helping facilitate the development of quality standards for the socket manufacturing industry. PMID:22773260

  9. Accuracy Verification of Magnetic Resonance Imaging (MRI) Technology for Lower-Limb Prosthetic Research: Utilising Animal Soft Tissue Specimen and Common Socket Casting Materials

    OpenAIRE

    Safari, Mohammad Reza; Rowe, Philip; Buis, Arjan

    2012-01-01

    Lower limb prosthetic socket shape and volume consistency can be quantified using MRI technology. Additionally, MRI images of the residual limb could be used as an input data for CAD-CAM technology and finite element studies. However, the accuracy of MRI when socket casting materials are used has to be defined. A number of six, 46 mm thick, cross-sections of an animal leg were used. Three specimens were wrapped with Plaster of Paris (POP) and the other three with commercially available silico...

  10. Interface stress in socket/residual limb with transtibial prosthetic suspension systems during locomotion on slopes and stairs.

    Science.gov (United States)

    Eshraghi, Arezoo; Abu Osman, Noor Azuan; Gholizadeh, Hossien; Ali, Sadeeq; Abas, Wan Abu Bakar Wan

    2015-01-01

    This study aimed to compare the effects of different suspension methods on the interface stress inside the prosthetic sockets of transtibial amputees when negotiating ramps and stairs. Three transtibial prostheses, with a pin/lock system, a Seal-In system, and a magnetic suspension system, were created for the participants in a prospective study. Interface stress was measured as the peak pressure by using the F-socket transducers during stairs and ramp negotiation. Twelve individuals with transtibial amputation managed to complete the experiments. During the stair ascent and descent, the greatest peak pressure was observed in the prosthesis with the Seal-In system. The magnetic prosthetic suspension system caused significantly different peak pressure at the anterior proximal region compared with the pin/lock (P = 0.022) and Seal-In (P = 0.001) during the stair ascent. It was also observed during the stair descent and ramp negotiation. The prostheses exhibited varying pressure profiles during the stair and ramp ascent. The prostheses with the pin/lock and magnetic suspension systems exhibited lower peak pressures compared with the Seal-In system. The intrasystem pressure distribution at the anterior and posterior regions of the residual limb was fairly homogenous during the stair and ramp ascent and descent. Nevertheless, the intrasystem pressure mapping revealed a significant difference among the suspension types, particularly at the anterior and posterior sensor sites.

  11. Alveolar socket healing: what can we learn?

    Science.gov (United States)

    Araújo, Mauricio G; Silva, Cléverson O; Misawa, Mônica; Sukekava, Flavia

    2015-06-01

    Tooth extraction induces a series of complex and integrated local changes within the investing hard and soft tissues. These local alterations arise in order to close the socket wound and to restore tissue homeostasis, and are referred to as '"socket healing". The aims of the present report were twofold: first, to describe the socket-healing process; and, second, to discuss what can be learned from the temporal sequence of healing events, in order to improve treatment outcomes. The socket-healing process may be divided into three sequential, and frequently overlapping, phases: inflammatory; proliferative; and modeling/remodeling. Several clinical and experimental studies have demonstrated that the socket-healing process promotes up to 50% reduction of the original ridge width, greater bone resorption at the buccal aspect than at the lingual/palatal counterpart and a larger amount of alveolar bone reduction in the molar region. In conclusion, tooth extraction, once a simple and straightforward surgical procedure, should be performed in the knowledge that ridge reduction will follow and that further clinical steps should be considered to compensate for this, when considering future options for tooth replacement. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  12. A histomorphometric study of the effect of doxycycline and erythromycin on bone formation in dental alveolar socket of rat

    Directory of Open Access Journals (Sweden)

    Mohammad Shahabooei

    2015-01-01

    Full Text Available Background: The aim of the present study was to evaluate whether subantimicrobial doses of doxycycline (DOX and erythromycin (EM used for the treatment of peri-implant osteolysis due to their anti-osteoclastogenesis can interfere with the osseous wound healing process in rat alveolar socket. Materials and Methods: Forty-five male Wistar rats had their first maxillary right molar extracted and were divided into three groups. DOX and EM at the doses of 5 mg/kg/day orally (p.o. and 2 mg/kg/day intraperitoneally (i.p. were administered respectively to two separate groups for 7 days after operation. In the control group the animals received normal saline (5 ml/kg. Five rats were sacrificed at 7, 14 and 21 days post-extraction in each study group. A histomorphometric analysis was used to evaluate new bone formation inside the alveolar socket. Significant level was set at 0.05. Results: The findings showed that the percentage of new bone formation (NBF enhanced significantly on days 7 and 14. There was no significant difference in the NBF between DOX and EM groups. Conclusion: Short-term treatment with both DOX and EM enhanced new bone formation without any advances in favor of each drug.

  13. Hands-Off and Hands-On Casting Consistency of Amputee below Knee Sockets Using Magnetic Resonance Imaging

    Directory of Open Access Journals (Sweden)

    Mohammad Reza Safari

    2013-01-01

    Full Text Available Residual limb shape capturing (Casting consistency has a great influence on the quality of socket fit. Magnetic Resonance Imaging was used to establish a reliable reference grid for intercast and intracast shape and volume consistency of two common casting methods, Hands-off and Hands-on. Residual limbs were cast for twelve people with a unilateral below knee amputation and scanned twice for each casting concept. Subsequently, all four volume images of each amputee were semiautomatically segmented and registered to a common coordinate system using the tibia and then the shape and volume differences were calculated. The results show that both casting methods have intra cast volume consistency and there is no significant volume difference between the two methods. Inter- and intracast mean volume differences were not clinically significant based on the volume of one sock criteria. Neither the Hands-off nor the Hands-on method resulted in a consistent residual limb shape as the coefficient of variation of shape differences was high. The resultant shape of the residual limb in the Hands-off casting was variable but the differences were not clinically significant. For the Hands-on casting, shape differences were equal to the maximum acceptable limit for a poor socket fit.

  14. Effects of local and whole body irradiation on appearance of osteoclasts during wound healing of tooth extraction sockets in rats

    International Nuclear Information System (INIS)

    Hosokawa, Yoichiro; Sakakura, Yasunori; Tanaka, Likinobu; Okumura, Kazuhiko; Yajima, Toshihiko; Kaneko, Masayuki

    2007-01-01

    We examined effects of local and whole body irradiation before tooth extraction on appearance and differentiation of osteoclasts in the alveolar bone of rat maxillary first molars. Wistar rats weighting 100 g were divided into three groups: non-irradiation group, local irradiation group, and whole body irradiation group. In the local irradiation group, a field made with lead blocks was placed over the maxillary left first molar tooth. In the whole body irradiation group, the animals were irradiated in cages. Both groups were irradiated at 8 Gy. The number of osteoclasts around the interradicular alveolar bone showed chronological changes common to non-irradiated and irradiated animals. Several osteoclasts appeared one day after tooth extraction, and the maximal peak was observed 3 days after extraction. Local irradiation had no difference from non-irradiated controls. In animals receiving whole body irradiation, tooth extraction one day after irradiation caused smaller number of osteoclasts than that 7 day after irradiation during the experimental period. Whole body-irradiated rats had small osteoclasts with only a few nuclei and narrow resorption lacunae, indicating deficiency of radioresistant osteoclast precursor cells. Injection of intact bone marrow cells to whole body-irradiated animals immediately after tooth extraction recovered to some content the number of osteoclasts. These findings suggest that bone resorption in the wound healing of alveolar socket requires radioresistant, postmitotic osteoclast precursor cells from hematopoietic organs, but not from local sources around the alveolar socket, at the initial phase of wound healing. (author)

  15. Effects of local and whole body irradiation on appearance of osteoclasts during wound healing of tooth extraction sockets in rats.

    Science.gov (United States)

    Hosokawa, Yoichiro; Sakakura, Yasunori; Tanaka, Likinobu; Okumura, Kazuhiko; Yajima, Toshihiko; Kaneko, Masayuki

    2007-07-01

    We examined effects of local and whole body irradiation before tooth extraction on appearance and differentiation of osteoclasts in the alveolar bone of rat maxillary first molars. Wistar rats weighting 100 g were divided into three groups: non-irradiation group, local irradiation group, and whole body irradiation group. In the local irradiation group, a field made with lead blocks was placed over the maxillary left first molar tooth. In the whole body irradiation group, the animals were irradiated in cages. Both groups were irradiated at 8 Gy. The number of osteoclasts around the interradicular alveolar bone showed chronological changes common to non-irradiated and irradiated animals. Several osteoclasts appeared one day after tooth extraction, and the maximal peak was observed 3 days after extraction. Local irradiation had no difference from non-irradiated controls. In animals receiving whole body irradiation, tooth extraction one day after irradiation caused smaller number of osteoclasts than that 7 day after irradiation during the experimental period. Whole body-irradiated rats had small osteoclasts with only a few nuclei and narrow resorption lacunae, indicating deficiency of radioresistant osteoclast precursor cells. Injection of intact bone marrow cells to whole body-irradiated animals immediately after tooth extraction recovered to some content the number of osteoclasts. These findings suggest that bone resorption in the wound healing of alveolar socket requires radioresistant, postmitotic osteoclast precursor cells from hematopoietic organs, but not from local sources around the alveolar socket, at the initial phase of wound healing.

  16. 3D Coulomb balls: experiment and simulation

    International Nuclear Information System (INIS)

    Arp, O; Block, D; Bonitz, M; Fehske, H; Golubnychiy, V; Kosse, S; Ludwig, P; Melzer, A; Piel, A

    2005-01-01

    Spherically symmetric three-dimensional charged particle clusters are analyzed experimentally and theoretically. Based on accurate molecular dynamics simulations ground state configurations and energies with clusters for N ≤ 160 are presented which correct previous results of Hasse and Avilov [Phys. Rev. A 44, 4506 (1991)]. A complete table is given in the appendix. Further, the lowest metastable states are analyzed

  17. Sports injuries in adolescents' ball games: soccer, handball and basketball.

    OpenAIRE

    Yde, J; Nielsen, A B

    1990-01-01

    In a prospective study of 302 adolescent players in three ball games (soccer, handball and basketball), 119 incurred injuries. The injury incidence (number of injuries per 1000 playing hours) was 5.6 in soccer, 4.1 in handball and 3.0 in basketball. Ankle sprains accounted for 25 per cent of the injuries, finger sprains 32 per cent, strains in the thigh and leg 10 per cent, and tendinitis/apophysitis 12 per cent. The most serious injuries were four fractures, one anterior cruciate ligament ru...

  18. 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

    in passing success rate (NB: 68±1% and SB: 68±1%, p>0.05). In conclusion, high-level adult female footballers had a higher kicking speed when using a smaller, lighter ball, but no differences were observed during match-play with the 2 ball types in respect of technical-tactical and physical match performance......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.......08±0.42 and 1.94±0.38 km; p>0.05) and match-induced decrement in Yo-Yo IR1 performance (28 vs. 31%, respectively, p

  19. The Efficacy of Hyaluronic Acid in Postextraction Sockets of ...

    African Journals Online (AJOL)

    The Efficacy of Hyaluronic Acid in Postextraction Sockets of Impacted Third Molars: A Pilot Study. ... HA can produce an analgesic action in postextraction sockets after surgical removal of impacted teeth and therefore it has a clinical benefit to reduce usage of nonsteroidal anti-inflammatory drugs after dentoalveolar surgery.

  20. Fabrication and Study of Micro Monolithic Tungsten Ball Tips for Micro/Nano-CMM Probes

    OpenAIRE

    Ruijun Li; Chen Chen; Kuangchao Fan; Zhiwei Wang; Fangfang Liu; Qiangxian Huang

    2018-01-01

    Micro ball tips with high precision, small diameter, and high stiffness stems are required to measure microstructures with high aspect ratio. Existing ball tips cannot meet such demands because of their weak qualities. This study used an arc-discharge melting method to fabricate a micro monolithic tungsten ball tip on a tungsten stylus. The principles of arc discharge and surface tension phenomenon were introduced. The experimental setup was designed and established. Appropriate process param...

  1. Dual PD Control Regulation with Nonlinear Compensation for a Ball and Plate System

    Directory of Open Access Journals (Sweden)

    Sergio Galvan-Colmenares

    2014-01-01

    Full Text Available The normal proportional derivative (PD control is modified to a new dual form for the regulation of a ball and plate system. First, to analyze this controller, a novel complete nonlinear model of the ball and plate system is obtained. Second, an asymptotic stable dual PD control with a nonlinear compensation is developed. Finally, the experimental results of ball and plate system are provided to verify the effectiveness of the proposed methodology.

  2. Solving ball lightning—A reply to Stefan and Massey (2008)

    Science.gov (United States)

    Coleman, Peter Francis

    2009-06-01

    Comments are made on the ball lightning paper of Stephan and Massey [Stefan, K.D., Massey, N., 2008. Burning molten metallic sphere: One class of ball lightning? Journal of Atmospheric and Solar-Terrestrial Physics 70, 1589-1596] that describes their [`]welding drop' theory. An alternative theory is offered based on combustion inside an atmospheric vortex. The [`]vortex fireball' hypothesis has good explanatory capability in regard to published ball lightning properties.

  3. Statics and dynamics of a self-bound matter-wave quantum ball

    Science.gov (United States)

    Adhikari, S. K.

    2017-02-01

    We study the statics and dynamics of a stable, mobile, three-dimensional matter-wave spherical quantum ball created in the presence of an attractive two-body and a very small repulsive three-body interaction. The quantum ball can propagate with a constant velocity in any direction in free space and its stability under a small perturbation is established numerically and variationally. In frontal head-on and angular collisions at large velocities two quantum balls behave like quantum solitons. Such collision is found to be quasielastic and the quantum balls emerge after collision without any change of direction of motion and velocity and with practically no deformation in shape. When reflected by a hard impenetrable plane, the quantum ball bounces off like a wave obeying the law of reflection without any change of shape or speed. However, in a collision at small velocities two quantum balls coalesce to form a larger ball which we call a quantum-ball breather. We point out the similarity and difference between the collision of two quantum and classical balls. The present study is based on an analytic variational approximation and a full numerical solution of the mean-field Gross-Pitaevskii equation using the parameters of 7Li atoms.

  4. Immediate Implants Placed in Fresh Sockets Associated with Periapical Pathology: A Split-Mouth Design and Survival Evaluation after 1-Year Follow-Up.

    Science.gov (United States)

    Hita-Iglesias, Cristina; Sánchez-Sánchez, Francisco J; Montero, Javier; Galindo-Moreno, Pablo; Mesa, Francisco; Martínez-Lara, Ildefonso; Sánchez-Fernández, Elena

    2016-12-01

    To compare the immediate implant success rates between sites with chronic apical lesions and healthy sites in the same patients 1 year postdelayed loading. One hundred sixty-eight immediate implants were placed in sixty patients at upper incisor, canine, and premolar sites. A split-mouth design was used, placing a minimum of two implants, one in a fresh socket associated with chronic periapical disease, the average lesion size was larger than 4 mm and less than 8 mm (test group), and the other(s) in a healthy fresh socket (control group). Implant survival rate at 1 year postloading delayed was compared between the groups. The implant survival rate was 98.2% for the total sample (n = 168); out of the three implants lost, two were from the test group, and one was from the control group (in the same patient as one of the former). Among the surviving implants, five were also considered failures due to excessive bone loss (n = 3) and also because of the recurrence of the periapical lesions (n = 2). Survival rates were significantly lower in the test than control sites at 12 months postloading. Implant survival rates were significantly lower after the immediate implantation in postextraction sockets associated with chronic periapical disease (90.8%) than in healthy postextraction sockets (98.1%). © 2015 Wiley Periodicals, Inc.

  5. AN EXPERIMENTAL INVESTIGATION OF NEGATIVE POINT-PLANE CORONA AND ITS RELATION TO BALL LIGHTNING

    Science.gov (United States)

    Existing theories of ball lightning are briefly discussed. the corona discharge from a negative point flows in a series of regular pulses called...trichel pulses. based on the theoretical relationship between corona discharge (trichel pulses) and ball lightning , an experimental program is developed...pulse-repetition frequencies of a few mc/s have been the highest attained in the course of the experiments. the results obtained are then discussed as they concern ball lightning .

  6. Influence of surgical and prosthetic techniques on marginal bone loss around titanium implants. Part I: immediate loading in fresh extraction sockets.

    Science.gov (United States)

    Berberi, Antoine N; Tehini, Georges E; Noujeim, Ziad F; Khairallah, Alexandre A; Abousehlib, Moustafa N; Salameh, Ziad A

    2014-10-01

    Delayed placement of implant abutments has been associated with peri-implant marginal bone loss; however, long-term results obtained by modifying surgical and prosthetic techniques after implant placement are still lacking. This study aimed to evaluate the marginal bone loss around titanium implants placed in fresh extraction sockets using two loading protocols after a 5-year follow-up period. A total of 36 patients received 40 titanium implants (Astra Tech) intended for single-tooth replacement. Implants were immediately placed into fresh extraction sockets using either a one-stage (immediate loading by placing an interim prosthesis into functional occlusion) or a two-stage prosthetic loading protocol (insertion of abutments after 8 weeks of healing time). Marginal bone levels relative to the implant reference point were evaluated at four time intervals using intraoral radiographs: at time of implant placement, and 1, 3, and 5 years after implant placement. Measurements were obtained from mesial and distal surfaces of each implant (α = 0.05). One-stage immediate implant placement into fresh extraction sockets resulted in a significant reduction in marginal bone loss (p implants after cementation of interim prostheses (p immediate loading of implants placed into fresh extraction sockets reduced marginal bone loss and did not compromise the success rate of the restorations. © 2014 by the American College of Prosthodontists.

  7. Socket sclerosis--an obstacle for orthodontic space closure?

    Science.gov (United States)

    Baumgaertel, Sebastian

    2009-07-01

    Socket sclerosis is a rare reaction to tooth extraction resulting in high-density bone in the center of the alveolar process, where, under normal circumstances, cancellous bone is to be expected. In an adult orthodontic patient, routine extractions of the mandibular first permanent bicuspids were performed, resulting in socket sclerosis and unsuccessful orthodontic space closure. Orthodontic mini-implants were inserted to augment anchorage and aid in space closure. In the presence of socket sclerosis, conventional orthodontic mechanics failed to close the extraction spaces. However, with absolute anchorage in place, space closure occurred at a nearly normal rate. After treatment, no signs of socket sclerosis were discernible on the periapical radiographs. Socket sclerosis can be an obstacle for orthodontic space closure if traditional mechanics are employed. However, mini-implant-reinforced anchorage can lead to successful space closure, resulting in complete resolution of the sclerotic sites.

  8. Effects of platelet-poor plasma, platelet-rich plasma, and platelet-rich fibrin on healing of extraction sockets with buccal dehiscence in dogs.

    Science.gov (United States)

    Hatakeyama, Ichiro; Marukawa, Eriko; Takahashi, Yukinobu; Omura, Ken

    2014-02-01

    Alveolar bone resorption generally occurs during healing after tooth extraction. This study aimed to evaluate the effects of platelet-poor plasma (PPP), platelet-rich plasma (PRP), and platelet-rich fibrin (PRF) on healing in a ridge-augmentation model of the canine socket with dehiscence of the buccal wall. The third mandibular premolars of 12 beagle dogs were extracted and a 3 mm buccal dehiscence from the alveolar crest to the buccal wall of the extraction socket was created. These sockets were then divided into four groups on the basis of the material used to fill the sockets: PPP, PRP, PRF, and control (no graft material) groups. Results were evaluated at 4 and 8 weeks after surgery. The ultrastructural morphology and constructs of each blood product were studied by a scanning electron microscope (SEM) or calculating concentrations of platelets, fibrinogen, platelet-derived growth factor, and transforming growth factor-β. A total of five microcomputed tomography images of specimens were selected for measurement, and the area occupied by the newly formed bone as well as the horizontal bone width were measured. Moreover, decalcified tissue specimens from each defect were analyzed histologically. The median area of new bone at 4 and 8 weeks and median horizontal bone width at 8 weeks were the highest in the PPP group. However, bone maturation in the PRF and the PRP groups was more progressed than that in the PPP and control groups. By SEM findings, the PRF group showed a more highly condensed fibrin fiber network that was regularly arranged when compared with the PPP and PRP groups. The growth factors released from platelets in PRP indicated higher concentrations than that in PRF. Under more severe conditions for bone formation, as in this experiment, the growth factors released from platelets had a negative effect on bone formation. This study showed that PPP is an effective material for the preservation of sockets with buccal dehiscence.

  9. Effects of Platelet-Poor Plasma, Platelet-Rich Plasma, and Platelet-Rich Fibrin on Healing of Extraction Sockets with Buccal Dehiscence in Dogs

    Science.gov (United States)

    Hatakeyama, Ichiro; Takahashi, Yukinobu; Omura, Ken

    2014-01-01

    Alveolar bone resorption generally occurs during healing after tooth extraction. This study aimed to evaluate the effects of platelet-poor plasma (PPP), platelet-rich plasma (PRP), and platelet-rich fibrin (PRF) on healing in a ridge-augmentation model of the canine socket with dehiscence of the buccal wall. The third mandibular premolars of 12 beagle dogs were extracted and a 3 mm buccal dehiscence from the alveolar crest to the buccal wall of the extraction socket was created. These sockets were then divided into four groups on the basis of the material used to fill the sockets: PPP, PRP, PRF, and control (no graft material) groups. Results were evaluated at 4 and 8 weeks after surgery. The ultrastructural morphology and constructs of each blood product were studied by a scanning electron microscope (SEM) or calculating concentrations of platelets, fibrinogen, platelet-derived growth factor, and transforming growth factor-β. A total of five microcomputed tomography images of specimens were selected for measurement, and the area occupied by the newly formed bone as well as the horizontal bone width were measured. Moreover, decalcified tissue specimens from each defect were analyzed histologically. The median area of new bone at 4 and 8 weeks and median horizontal bone width at 8 weeks were the highest in the PPP group. However, bone maturation in the PRF and the PRP groups was more progressed than that in the PPP and control groups. By SEM findings, the PRF group showed a more highly condensed fibrin fiber network that was regularly arranged when compared with the PPP and PRP groups. The growth factors released from platelets in PRP indicated higher concentrations than that in PRF. Under more severe conditions for bone formation, as in this experiment, the growth factors released from platelets had a negative effect on bone formation. This study showed that PPP is an effective material for the preservation of sockets with buccal dehiscence. PMID:24098948

  10. Pressure characteristics at the stump/socket interface in transtibial amputees using an adaptive prosthetic foot.

    Science.gov (United States)

    Wolf, Sebastian I; Alimusaj, Merkur; Fradet, Laetitia; Siegel, Johannes; Braatz, Frank

    2009-12-01

    The technological advances that have been made in developing highly functional prostheses are promising for very active patients but we do not yet know whether they cause an increase in biomechanical load along with possibly negative consequences for pressure conditions in the socket. Therefore, this study monitored the socket pressure at specific locations of the stump when using a microprocessor-controlled adaptive prosthetic ankle under different walking conditions. Twelve unilateral transtibial amputees between 43 and 59 years of age were provided with the Proprio-Foot (Ossur) and underwent an instrumented 3D gait analysis in level, stair, and incline walking, including synchronous data capturing of socket pressure. Peak pressures and pressure time integrals (PTI) at three different locations were compared for five walking conditions with and without using the device's ankle adaptation mode. Highest peak pressures of 2.4 k Pa/kg were found for incline ascent at the calf muscle as compared to 2.1 k Pa/kg in level walking with large inter-individual variance. In stair ascent a strong correlation was found between maximum knee moment and socket pressure. The most significant pressure changes relative to level walking were seen in ramp descent anteriorly towards the stump end, with PTI values being almost twice as high as those in level walking. Adapting the angle of the prosthesis on stairs and ramps modified the pressure data such that they were closer to those in level walking. Pressure at the stump depends on the knee moments involved in each walking condition. Adapting the prosthetic ankle angle is a valuable means of modifying joint kinetics and thereby the pressure distribution at the stump. However, large inter-individual differences in local pressures underline the importance of individual socket fitting.

  11. 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…

  12. Method and apparatus for jetting, manufacturing and attaching uniform solder balls

    Science.gov (United States)

    Yost, F.G.; Frear, D.R.; Schmale, D.T.

    1999-01-05

    An apparatus and process are disclosed for jetting molten solder in the form of balls directly onto all the metallized interconnects lands for a ball grid array package in one step with no solder paste required. Molten solder is jetted out of a grid of holes using a piston attached to a piezoelectric crystal. When voltage is applied to the crystal it expands forcing the piston to extrude a desired volume of solder through holes in the aperture plate. When the voltage is decreased the piston reverses motion creating an instability in the molten solder at the aperture plate surface and thereby forming spherical solder balls that fall onto a metallized substrate. The molten solder balls land on the substrate and form a metallurgical bond with the metallized lands. The size of the solder balls is determined by a combination of the size of the holes in the aperture plate, the duration of the piston pulse, and the displacement of the piston. The layout of the balls is dictated by the location of the hooks in the grid. Changes in ball size and layout can be easily accomplished by changing the grid plate. This invention also allows simple preparation of uniform balls for subsequent supply to BGA users. 7 figs.

  13. An investigation of the generation and properties of laboratory-produced ball lightning

    Science.gov (United States)

    Oreshko, A. G.

    2015-06-01

    The experiments revealed that ball lightning is a self-confining quasi-neutral in a whole plasma system that rotates around its axis. Ball lightning has a structure of a spherical electric domain, consisting of a kernel with excess negative charge and an external spherical layer with excess positive charge. The excess of charges of one sort and the lack of charges of the other sort in the kernel or in the external spherical layer significantly reduces the possibility of electron capture by means of an electric field, created by the nearest ions and leads to a drastic slowdown of recombination process. Direct proof has been obtained that inside of ball lightning - in an external spherical layer that rotates around the axis - there is a circular current of sub-relativistic particles. This current creates and maintains its own poloidal magnetic field of ball lightning, i.e. it carries out the function of magnetic dynamo. The kernel of ball lightning is situated in a region with minimum values of induction of the magnetic field. The inequality of positive and negative charges in elements of ball lightning also significantly reduces losses of the charged plasma on bremsstrahlung. Ball lightning generation occurs in a plasmic vortex. The ball lightning energy in the region of its generation significantly differs from the ball lightning energy, which is drifting in space. The axial component of kinetic energy of particles slightly exceeds 100 keV and the rotational component of the ions energy is a bit greater than 1 MeV. Ball lightning is `embedded' in atmosphere autonomous accelerator of charged particles of a cyclotron type due to self-generation of strong crossed electric and magnetic fields. A discussion of the conditions of stability and long-term existence of ball lightning is given.

  14. Core muscle activation during Swiss ball and traditional abdominal exercises.

    Science.gov (United States)

    Escamilla, Rafael F; Lewis, Clare; Bell, Duncan; Bramblet, Gwen; Daffron, Jason; Lambert, Steve; Pecson, Amanda; Imamura, Rodney; Paulos, Lonnie; Andrews, James R

    2010-05-01

    Controlled laboratory study using a repeated-measures, counterbalanced design. To test the ability of 8 Swiss ball exercises (roll-out, pike, knee-up, skier, hip extension right, hip extension left, decline push-up, and sitting march right) and 2 traditional abdominal exercises (crunch and bent-knee sit-up) on activating core (lumbopelvic hip complex) musculature. Numerous Swiss ball abdominal exercises are employed for core muscle strengthening during training and rehabilitation, but there are minimal data to substantiate the ability of these exercises to recruit core muscles. It is also unknown how core muscle recruitment in many of these Swiss ball exercises compares to core muscle recruitment in traditional abdominal exercises such as the crunch and bent-knee sit-up. A convenience sample of 18 subjects performed 5 repetitions for each exercise. Electromyographic (EMG) data were recorded on the right side for upper and lower rectus abdominis, external and internal oblique, latissimus dorsi, lumbar paraspinals, and rectus femoris, and then normalized using maximum voluntary isometric contractions (MVICs). EMG signals during the roll-out and pike exercises for the upper rectus abdominis (63% and 46% MVIC, respectively), lower rectus abdominis (53% and 55% MVIC, respectively), external oblique (46% and 84% MVIC, respectively), and internal oblique (46% and 56% MVIC, respectively) were significantly greater compared to most other exercises, where EMG signals ranged between 7% to 53% MVIC for the upper rectus abdominis, 7% to 44% MVIC for the lower rectus abdominis, 14% to 73% MVIC for the external oblique, and 16% to 47% MVIC for the internal oblique. The lowest EMG signals were consistently found in the sitting march right exercise. Latissimus dorsi EMG signals were greatest in the pike, knee-up, skier, hip extension right and left, and decline push-up (17%-25% MVIC), and least with the sitting march right, crunch, and bent-knee sit-up exercises (7%-8% MVIC

  15. Sport-Based Youth and Community Development: Beyond the Ball in Chicago

    Science.gov (United States)

    Jacobs, Jennifer M.; Castañeda, Amy; Castañeda, Rob

    2016-01-01

    Rob and Amy Castañeda, the co-founders of a sports/play-based youth and community development organization called Beyond the Ball (www.beyondtheball.org), cite the collaborative and dynamic nature of the TPSR Alliance as an important influence for their work. Beyond the Ball serves individuals between kindergarten and post-college, in the North…

  16. Life Estimation of Hip Joint Prosthesis

    Science.gov (United States)

    Desai, C.; Hirani, H.; Chawla, A.

    2014-11-01

    Hip joint is one of the largest weight-bearing structures in the human body. In the event of a failure of the natural hip joint, it is replaced with an artificial hip joint, known as hip joint prosthesis. The design of hip joint prosthesis must be such so as to resist fatigue failure of hip joint stem as well as bone cement, and minimize wear caused by sliding present between its head and socket. In the present paper an attempt is made to consider both fatigue and wear effects simultaneously in estimating functional-life of the hip joint prosthesis. The finite element modeling of hip joint prosthesis using HyperMesh™ (version 9) has been reported. The static analysis (load due to the dead weight of the body) and dynamic analysis (load due to walking cycle) have been described. Fatigue life is estimated by using the S-N curve of individual materials. To account for progressive wear of hip joint prosthesis, Archard's wear law, modifications in socket geometry and dynamic analysis have been used in a sequential manner. Using such sequential programming reduction in peak stress has been observed with increase in wear. Finally life is estimated on the basis of socket wear.

  17. Life Estimation of Hip Joint Prosthesis

    Science.gov (United States)

    Desai, C.; Hirani, H.; Chawla, A.

    2015-07-01

    Hip joint is one of the largest weight-bearing structures in the human body. In the event of a failure of the natural hip joint, it is replaced with an artificial hip joint, known as hip joint prosthesis. The design of hip joint prosthesis must be such so as to resist fatigue failure of hip joint stem as well as bone cement, and minimize wear caused by sliding present between its head and socket. In the present paper an attempt is made to consider both fatigue and wear effects simultaneously in estimating functional-life of the hip joint prosthesis. The finite element modeling of hip joint prosthesis using HyperMesh™ (version 9) has been reported. The static analysis (load due to the dead weight of the body) and dynamic analysis (load due to walking cycle) have been described. Fatigue life is estimated by using the S-N curve of individual materials. To account for progressive wear of hip joint prosthesis, Archard's wear law, modifications in socket geometry and dynamic analysis have been used in a sequential manner. Using such sequential programming reduction in peak stress has been observed with increase in wear. Finally life is estimated on the basis of socket wear.

  18. 48 CFR 252.225-7016 - Restriction on acquisition of ball and roller bearings.

    Science.gov (United States)

    2010-10-01

    ... of ball and roller bearings. 252.225-7016 Section 252.225-7016 Federal Acquisition Regulations System... and roller bearings. As prescribed in 225.7009-5, use the following clause: Restriction on Acquisition of Ball and Roller Bearings (MAR 2006) (a) Definitions. As used in this clause' (1) Bearing...

  19. Ball flight kinematics, release variability and in-season performance in elite baseball pitching.

    Science.gov (United States)

    Whiteside, D; McGinnis, R S; Deneweth, J M; Zernicke, R F; Goulet, G C

    2016-03-01

    The purpose of this study was to quantify ball flight kinematics (ball speed, spin rate, spin axis orientation, seam orientation) and release location variability in the four most common pitch types in baseball and relate them to in-season pitching performance. Nine NCAA Division I pitchers threw four pitching variations (fastball, changeup, curveball, and slider) while a radar gun measured ball speed and a 600-Hz video camera recorded the ball trajectory. Marks on the ball were digitized to measure ball flight kinematics and release location. Ball speed was highest in the fastball, though spin rate was similar in the fastball and breaking pitches. Two distinct spin axis orientations were noted: one characterizing the fastball and changeup, and another, the curveball and slider. The horizontal release location was significantly more variable than the vertical release location. In-season pitching success was not correlated to any of the measured variables. These findings are instructive for inferring appropriate hand mechanics and spin types in each of the four pitches. Coaches should also be aware that ball flight kinematics might not directly relate to pitching success at the collegiate level. Therefore, talent identification and pitching evaluations should encompass other (e.g., cognitive, psychological, and physiological) factors. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  20. Impact Velocity and Coefficient of Restitution for a Tennis Ball Impacting a Tennis Racquet

    Directory of Open Access Journals (Sweden)

    Mongkol Sukpraprut

    2015-01-01

    Full Text Available The impact and exit velocities of a tennis ball impacting on a fixed tennis racquet were measured with high speed video analysis to determine the coefficient of restitution (COR. It was found that there is a negative linear relationship between the COR and the impact velocity of the ball for velocities between 13 and 36 m/s.

  1. Physical and Tribological Properties of Nitrided AISI 316 Stainless Steel Balls

    Directory of Open Access Journals (Sweden)

    Yang Shicai

    2016-01-01

    Full Text Available AISI 316 austenitic stainless steel balls (diameters 5.0 and 12.0 mm, typical hardness 250 HV0.3 and flat samples (20×20×2.0 mm were nitrided by a pulsed glow discharge Ar/N2 plasma. Hardness of the ball surfaces was analysed using Vickers indentation. Thermal stability of the nitrided balls (diameter 12.0 mm was studied using a furnace to heat them in air for 8 hours at temperatures up to 700.0°C and then, after cooling to room temperature, the surface hardness of the heated balls was re-measured. Scanning electron microscopy and X-ray diffraction were used to study the microstructures, composition and phase formation of the nitrided sublayers. Unlubricated pin-on-disc wear testing was used to evaluate the wear resistance of nitrided stainless steel balls (5.0 mm diameter and the results were compared with similar testing on hardened Cr-Steel balls (5 mm diameter with hardness of about 650 HV0.3. All the test results indicated that the nitrided AISI 316 austenitic stainless steel balls have advantages over the hardened Cr-Steel balls in terms of retaining high hardness after heat treatment and high resistance to sliding wear at room temperature under higher counterpart stress. These properties are expected to be beneficial for wide range of bearing applications.

  2. 76 FR 35401 - Ball Bearings and Parts Thereof From Japan and the United Kingdom: Notice of Court Decision Not...

    Science.gov (United States)

    2011-06-17

    ... DEPARTMENT OF COMMERCE International Trade Administration [A-588-804, A-412-801] Ball Bearings and... orders on ball bearings and parts thereof from Japan and the United Kingdom. On April 20, [[Page 35402... redetermination that revocation of the antidumping duty orders on ball bearings and parts thereof from Japan and...

  3. Social Media and Big Data – Cracks in the Crystal Ball?

    NARCIS (Netherlands)

    Westera, Wim

    2013-01-01

    Westera, W. (2013, 14 October). Social Media and Big Data – Cracks in the Crystal Ball? Invited e-paper at ESOMAR RW Connect. http://rwconnect.esomar.org/using-social-media-for-market-analysis-cracks-in-the-alleged-crystal-ball/

  4. Radio spectrum measurements of artificial ball lightning and testing the hypothesis on its plasmochemical nature

    Science.gov (United States)

    Kopeikin, V. V.

    2014-01-01

    Spectral measurements of radiowaves emitted by artificial ball lightning are presented. The measurements were carried out using two different facilities: a pulsed power generator (PPG) and a three-contour Tesla transformer. The results of these measurements confirm the hypothesis that ball lightning is a self-oscillator of high-voltage pulses in the radio range.

  5. Contributions of Stephen J. Ball to the Research on Educational and Curriculum Policies in Brazil

    Science.gov (United States)

    Mainardes, Jefferson; Gandin, Luis Armando

    2013-01-01

    This article aims at showcasing the main contributions of Stephen J. Ball to educational research in Brazil, particularly to the study of educational and curriculum policies. We also highlight some of the limitations in the incorporation of Ball's ideas in Brazil as well as some of the challenges that these author's ideas pose to Brazilian…

  6. Collision of a Ball with a Barbell and Related Impulse Problems

    Science.gov (United States)

    Mungan, Carl E.

    2007-01-01

    The collision of a ball with the end of a barbell illustrates the combined conservation laws of linear and angular momentum. This paper considers the instructive but unfamiliar case where the ball's incident direction of travel makes an acute angle with the barbell's connecting rod. The analysis uses the coefficient of restitution generalized to…

  7. Survival of Phytophthora ramorum in Rhododendron root balls and in rootless substrates

    Science.gov (United States)

    A. Vercauteren; M. Riedel; M. Maes; S. Werres; K. Heungens

    2013-01-01

    This study assesses the survival of Phytophthora ramorum in the root ball of Rhododendron container plants as well as in different rootless forest substrates and a horticultural potting medium. Following inoculation of the root balls, the aboveground plant parts stayed symptomless, whilst the pathogen could be recovered with a...

  8. 76 FR 22372 - Ball Bearings and Parts Thereof From France, Germany, Italy, Japan, and the United Kingdom...

    Science.gov (United States)

    2011-04-21

    ...-804, A-412-801] Ball Bearings and Parts Thereof From France, Germany, Italy, Japan, and the United... administrative reviews of the antidumping duty orders on ball bearings and parts thereof from France, Germany...- in-interest to Schaeffler KG with respect to the order on ball bearings and parts thereof from...

  9. Generalised joint hypermobility and knee joint hypermobility

    DEFF Research Database (Denmark)

    Junge, Tina; Henriksen, Peter; Hansen, Sebrina

    2017-01-01

    (GJHk) is unknown for a general population. Therefore, the objectives were to report the prevalence of self-reported GJHk and KJH, as well as the association of these conditions to knee joint symptoms, severity and duration of symptoms, and health-related quality of life (HRQoL) in a Danish adult...... population. METHOD: This study is a cross-sectional population-based survey of 2056 Danish adults. Respondents received online questionnaires of GJHk and KJH, knee joint symptoms, the severity and duration of these, as well as HRQoL. RESULTS: Total response rate was 49% (n = 1006). The prevalence of self...... HRQoL. The impact of these conditions on HRQoL is comparable with knee osteoarthritis....

  10. 76 FR 41761 - Ball Bearings and Parts Thereof From Japan and the United Kingdom: Revocation of Antidumping Duty...

    Science.gov (United States)

    2011-07-15

    ... DEPARTMENT OF COMMERCE International Trade Administration [A-588-804, A-412-801] Ball Bearings and... Commerce (the Department) is revoking the antidumping duty orders on ball bearings and parts thereof from...: Background On May 15, 1989, the Department published the antidumping duty orders on ball bearings and parts...

  11. A smartphone photogrammetry method for digitizing prosthetic socket interiors.

    Science.gov (United States)

    Hernandez, Amaia; Lemaire, Edward

    2017-04-01

    Prosthetic CAD/CAM systems require accurate 3D limb models; however, difficulties arise when working from the person's socket since current 3D scanners have difficulties scanning socket interiors. While dedicated scanners exist, they are expensive and the cost may be prohibitive for a limited number of scans per year. A low-cost and accessible photogrammetry method for socket interior digitization is proposed, using a smartphone camera and cloud-based photogrammetry services. 15 two-dimensional images of the socket's interior are captured using a smartphone camera. A 3D model is generated using cloud-based software. Linear measurements were comparing between sockets and the related 3D models. 3D reconstruction accuracy averaged 2.6 ± 2.0 mm and 0.086 ± 0.078 L, which was less accurate than models obtained by high quality 3D scanners. However, this method would provide a viable 3D digital socket reproduction that is accessible and low-cost, after processing in prosthetic CAD software. Clinical relevance The described method provides a low-cost and accessible means to digitize a socket interior for use in prosthetic CAD/CAM systems, employing a smartphone camera and cloud-based photogrammetry software.

  12. Oscillating shells and oscillating balls in AdS

    Science.gov (United States)

    Banerjee, Avik; Kundu, Arnab; Roy, Pratik; Virmani, Amitabh

    2017-07-01

    It has recently been reported that certain thin timelike shells undergo oscillatory motion in AdS. In this paper, we compute two-point function of a probe field in the geodesic approximation in such an oscillating shell background. We confirm that the two-point function exhibits an oscillatory behaviour following the motion of the shell. We show that similar oscillatory dynamics is possible when the perfect fluid on the shell has a polytropic equation of state. Moreover, we show that certain ball like configurations in AdS also exhibit oscillatory motion and comment on how such a solution can be smoothly matched to an appropriate exterior solution. We also demonstrate that the weak energy condition is satisfied for these oscillatory configurations.

  13. Regularity and mechanism of wheat straw properties change in ball milling process at cellular scale.

    Science.gov (United States)

    Gao, Chongfeng; Xiao, Weihua; Ji, Guanya; Zhang, Yang; Cao, Yaoyao; Han, Lujia

    2017-10-01

    To investigate the change of structure and physicochemical properties of wheat straw in ball milling process at cellular scale, a series of wheat straws samples with different milling time were produced using an ultrafine vibration ball mill. A multitechnique approach was used to analyze the variation of wheat straw properties. The results showed that the characteristics of wheat straw powder displayed regular changes as a function of the milling time, i.e., the powder underwent the inversion of breakage to agglomerative regime during wheat straw ball milling process. The crystallinity index, bulk density and water retention capacity of wheat straw were exponential relation with ball milling time. Moreover, ball milling continually converted macromolecules of wheat straw cell wall into water-soluble substances resulting in the water extractives proportional to milling time. Copyright © 2017. Published by Elsevier Ltd.

  14. Walking in a vacuum-assisted socket shifts the stump fluid balance.

    Science.gov (United States)

    Goswami, J; Lynn, R; Street, G; Harlander, M

    2003-08-01

    Gains in stump volume have been documented in trans-tibial amputees while walking in custom made under-sized, total surface-bearing, vacuum-assisted sockets (Board et al., 2001). These gains raised doubts as to whether the sockets were truly under-sized and concerns that using an over-sized socket with vacuum-assist could lead to swelling, resulting, in discomfort or pain. The purposes of the present study were to determine if: (a) walking in a vacuum-assisted socket causes the stump to retain or gain volume in excess of the available socket volume and (b) the resulting increase in stump volume with an over-sized socket causes discomfort, pain, and/or the skin to redden. The results of this study showed the stump retained or gained volume in excess of the available socket volume while walking in vacuum-assisted sockets of various sizes. The stump lost less volume than predicted, or gained volume, in under-sized sockets. It also gained more volume than predicted in over-sized sockets. No discomfort, pain, or skin reddening, resulting from the volume gain was reported by any of the subjects after walking in an over-sized socket. This change in fluid balance towards a net gain supports the findings by Board et al. (2001) that vacuum-assist ensures a good fit during the day in ambulatory trans-tibial traumatic amputees with mature stumps.

  15. Formation and stabilization of multiple ball-like flames at Earth gravity

    KAUST Repository

    Zhou, Zhen

    2018-03-20

    Near-limit low-Lewis-number premixed flame behavior is studied experimentally and numerically for flames of H–CH–air mixtures that are located in a 55 mm diameter tube and below a perforated plate in a downward mixture flow. A combustion regime diagram is experimentally identified in terms of equivalence ratio and ratio of H to CH (variation of fuel Lewis number). Planar flames, cell-like flames, distorted cap-like flames, and arrays of ball-like flames are progressively observed in the experiments as the equivalence ratio is decreased. The experimentally observed ball-like lean limit flames experience chaotic motion, which is accompanied by sporadic events of flame splitting and extinction, while the total number of simultaneously burning flamelets remains approximately the same. In separate experiments, the multiple ball-like lean limit flames are stabilized by creating a slightly non-uniform mixture flow field. The CH* chemiluminescence distributions of the lean limit flames are recorded, showing that the ball-like lean limit flame front becomes more uniform in intensity and its shape approaches a spherical one with the increase of H content in the fuel. Numerical simulations are performed for single representative flames of the array of stabilized flamelets observed in the experiments. The simulated ball-like lean limit flame is further contrasted with the single ball-like flame that forms in a narrow tube (13.5 mm inner diameter) with an iso-thermal wall. The numerical results show that the ball-like lean limit flames present in the array of ball-like flames are more affected by the buoyancy-induced recirculation zone, compared with that in the narrow tube, revealing why the shape of the ball-like flame in the array deviates more from a spherical one. All in all, the wall confinement is not crucial for the formation of ball-like flames at terrestrial gravity.

  16. The Modified Socket Shield Technique.

    Science.gov (United States)

    Han, Chang-Hun; Park, Kwang-Bum; Mangano, Francesco Guido

    2018-03-20

    In the anterior regions, the resorption of the buccal bone after tooth extraction leads to a contraction of the overlying soft tissues, resulting in an esthetic problem, particularly with immediate implant placement. In the socket shield technique, the buccal root section of the tooth is maintained, to preserve the buccal bone for immediate implant placement. The aim of this prospective study was to investigate the survival, stability, and complication rates of implants placed using a "modified" socket shield technique. Over a 2-year period, all patients referred to a dental clinic for treatment with oral implants were considered for inclusion in this study. Inclusion criteria were healthy adult patients who presented nonrestorable single teeth with intact buccal periodontal tissues in the anterior regions of both jaws. Exclusion criteria were teeth with present/past periodontal disease, vertical root fractures on the buccal aspect, horizontal fractures below bone level, and external/internal resorptions. The buccal portion of the root was retained to prevent the resorption of the buccal bone; the shield was 1.5 mm thick with the most coronal portion at the bone crest level. All patients then underwent immediate implants. In the patient with a gap between the implant and shield, no graft material was placed. All implants were immediately restored with single crowns and followed for 1 year. The main outcomes were implant survival, stability, and complications. Thirty patients (15 males, 15 females; mean age was 48.2 ± 15.0 years) were enrolled in the study and installed with 40 immediate implants. After 1 year, all implants were functioning, for a survival rate of 100%; excellent implant stability was reported (mean implant stability quotient at placement: 72.9 ± 5.9; after 1 year: 74.6 ± 2.7). No biologic complications were reported, and the incidence of prosthetic complications was low (2.5%). The "modified" socket shield technique seems to be a

  17. Prosthetics socket that incorporates an air splint system focusing on dynamic interface pressure.

    Science.gov (United States)

    Razak, Nasrul Anuar Abd; Osman, Noor Azuan Abu; Gholizadeh, Hossein; Ali, Sadeeq

    2014-08-01

    The interface pressure between the residual limb and prosthetic socket has a significant effect on an amputee's satisfaction and comfort. This paper presents the design and performance of a new prosthetic socket that uses an air splint system. The air splint prosthetic socket system was implemented by combining the air splint with a pressure sensor that the transhumeral user controls through the use of a microcontroller. The modular construction of the system developed allows the FSR pressure sensors that are placed inside the air splint socket to determine the required size and fitting for the socket used. Fifteen transhumeral amputees participated in the study. The subject's dynamic pressure on the socket that's applied while wearing the air splint systems was recorded using F-socket transducers and microcontroller analysis. The values collected by the F-socket sensor for the air splint prosthetic socket system were determined accordingly by comparing the dynamic pressure applied using statically socket. The pressure volume of the air splint fluctuated and was recorded at an average of 38 kPa (2.5) to 41 kPa (1.3) over three hours. The air splint socket might reduce the pressure within the interface of residual limb. This is particularly important during the daily life activities and may reduce the pain and discomfort at the residual limb in comparison to the static socket. The potential development of an auto-adjusted socket that uses an air splint system as the prosthetic socket will be of interest to researchers involved in rehabilitation engineering, prosthetics and orthotics.

  18. Birth of ball lightning

    Science.gov (United States)

    Lowke, J. J.; Smith, D.; Nelson, K. E.; Crompton, R. W.; Murphy, A. B.

    2012-10-01

    Many observations of ball lightning report a ball of light, about 10 cm in diameter, moving at about walking speed, lasting up to 20 s and frequently existing inside of houses and even aeroplanes. The present paper reports detailed observations of the initiation or birth of ball lightning. In two cases, navigation crew of aircraft saw ball lightning form at the windscreen inside the cockpit of their planes. In the first case, the ball lightning occurred during a thunderstorm, with much lightning activity outside of the plane. In the second case, large "horns" of electrical corona were seen outside of the plane at the surface of the radome, just prior to the formation of the ball lightning. A third case reports ball lightning formed inside of a house, during a thunderstorm, at a closed glass window. It is proposed, based on two-dimensional calculations of electron and ion transport, that ball lightning in these cases is driven and formed by atmospheric ions impinging and collecting on the insulating surface of the glass or Perspex windows. This surface charge can produce electric fields inside of the cockpit or room sufficient to sustain an electric discharge. Charges of opposite sign to those outside of the window accumulate on the inside surface of the glass, leaving a ball of net charge moving inside of the cockpit or room to produce a pulsed discharge on a microsecond time scale.

  19. Prevalence of malformations of the hip joint and their relationship to sex, groin pain, and risk of osteoarthritis: a population-based survey

    DEFF Research Database (Denmark)

    Gosvig, Kasper Kjaerulf; Jacobsen, Steffen; Sonne-Holm, Stig

    2010-01-01

    BACKGROUND: Although the clinical consequences of femoroacetabular impingement have been well described, little is known about the prevalence of the anatomical malformations associated with this condition in the general population, the natural history of the condition, and the risk estimates...... of Østerbro, Copenhagen, Denmark. The inclusion criteria for this study were met by 1332 men and 2288 women. On the basis of radiographic criteria, the hips were categorized as being without malformations or as having an abnormality consisting of a deep acetabular socket, a pistol grip deformity......, or a combination of a deep acetabular socket and a pistol grip deformity. Hip osteoarthritis was defined radiographically as a minimum joint-space width of 0.13). A deep acetabular socket was a significant risk factor for the development of osteoarthritis (risk ratio, 2.4), as was a pistol grip deformity (risk...

  20. 75 FR 41435 - Ball Bearings and Parts Thereof From Germany: Notice of Court Decision Not in Harmony With Final...

    Science.gov (United States)

    2010-07-16

    ... DEPARTMENT OF COMMERCE International Trade Administration [A-428-801] Ball Bearings and Parts... antidumping duty order on ball bearings and parts thereof from Germany. See SKF USA Inc., v. United States... administrative reviews of the antidumping duty orders on ball bearings and parts thereof from France, Germany...

  1. Socket Shield Technique

    OpenAIRE

    Ferreira, João Eduardo Freitas

    2017-01-01

    Nos dias atuais, é cada vez mais comum a realização de extrações de dentes que estejam severamente comprometidos e substituí-los por implantes dentários. Após extração, existe uma reabsorção de osso alveolar que vai resultar numa perda de osso vertical e horizontal, tornando-se um dos fatores que subsequentemente se vai colocar como uma das maiores dificuldades na colocação de implantes. A técnica Socket Shield é uma técnica de preservação de osso alveolar em situações de implantes imediatos,...

  2. Using a 3DOF Parallel Robot and a Spherical Bat to Hit a Ping-Pong Ball

    Directory of Open Access Journals (Sweden)

    Alberto Trasloheros

    2014-05-01

    Full Text Available Playing the game of Ping-Pong is a challenge to human abilities since it requires developing skills, such as fast reaction capabilities, precision of movement and high speed mental responses. These processes include the utilization of seven DOF of the human arm, and translational movements through the legs, torso, and other extremities of the body, which are used for developing different game strategies or simply imposing movements that affect the ball such as spinning movements. Computationally, Ping-Pong requires a huge quantity of joints and visual information to be processed and analysed, something which really represents a challenge for a robot. In addition, in order for a robot to develop the task mechanically, it requires a large and dexterous workspace, and good dynamic capacities. Although there are commercial robots that are able to play Ping-Pong, the game is still an open task, where there are problems to be solved and simplified. All robotic Ping-Pong players cited in the bibliography used at least four DOF to hit the ball. In this paper, a spherical bat mounted on a 3-DOF parallel robot is proposed. The spherical bat is used to drive the trajectory of a Ping-Pong ball.

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

    Science.gov (United States)

    Luo, Yong; Ran, Guang; Chen, Nanjun; Shen, Qiang; Zhang, Yaoli

    2016-10-15

    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.

  4. A Tsunami Ball Approach to Storm Surge and Inundation: Application to Hurricane Katrina, 2005

    Directory of Open Access Journals (Sweden)

    Steven N. Ward

    2009-01-01

    Full Text Available Most analyses of storm surge and inundation solve equations of continuity and momentum on fixed finite-difference/finite-element meshes. I develop a completely new approach that uses a momentum equation to accelerate bits or balls of water over variable depth topography. The thickness of the water column at any point equals the volume density of balls there. In addition to being more intuitive than traditional methods, the tsunami ball approach has several advantages. (a By tracking water balls of fixed volume, the continuity equation is satisfied automatically and the advection term in the momentum equation becomes unnecessary. (b The procedure is meshless in the finite-difference/finite-element sense. (c Tsunami balls care little if they find themselves in the ocean or inundating land. (d Tsunami ball calculations of storm surge can be done on a laptop computer. I demonstrate and calibrate the method by simulating storm surge and inundation around New Orleans, Louisiana caused by Hurricane Katrina in 2005 and by comparing model predictions with field observations. To illustrate the flexibility of the tsunami ball technique, I run two “What If” hurricane scenarios—Katrina over Savannah, Georgia and Katrina over Cape Cod, Massachusetts.

  5. A 5-year comparison of marginal bone level following immediate loading of single-tooth implants placed in healed alveolar ridges and extraction sockets in the maxilla

    Science.gov (United States)

    Berberi, Antoine N.; Sabbagh, Joseph M.; Aboushelib, Moustafa N.; Noujeim, Ziad F.; Salameh, Ziad A.

    2014-01-01

    Purpose: The aim of present investigation was to evaluate marginal bone level after 5-year follow-up of implants placed in healed ridges and fresh extraction sockets in maxilla with immediate loading protocol. Materials and Methods: Thirty-six patients in need of a single-tooth replacement in the anterior maxilla received 42 Astra Tech implants (Astra Tech Implant system™, Dentsply Implants, Mölndal, Sweden). Implants were placed either in healed ridges (group I) or immediately into fresh extraction sockets (group II). Implants were restored and placed into functional loading immediately by using a prefabricated abutment. Marginal bone level relative to the implant reference point was recorded at implant placement, crown cementation, 12, 36, and 60 months following loading using intra-oral radiographs. Measurements were made on the mesial and distal sides of each implant. Results: Overall, two implants were lost from the group II, before final crown cementation: they were excluded from the study. The mean change in marginal bone loss (MBL) after implant placement was 0.26 ± 0.161 mm for 1 year, and 0.26 ± 0.171 mm for 3 years, and 0.21 ± 0.185 mm for 5 years in extraction sockets and was 0.26 ± 0.176 mm for 1 year and 0.21 ± 0.175 mm for 3 years, and 0.19 ± 0.172 mm for 5 years in healed ridges group. Significant reduction of marginal bone was more pronounced in implants inserted in healed ridges (P implant after cementation of the provisional (P immediately loaded implants placed either in extraction sockets or healed ridges were similar. Functional loading technique by using prefabricated abutment placed during the surgery time seems to maintain marginal bone around implant in both healed and fresh extraction sites. PMID:24550840

  6. Effects of long-distance walking on socket-limb interface pressure, tactile sensitivity and subjective perceptions of trans-tibial amputees.

    Science.gov (United States)

    Yeung, L F; Leung, Aaron K L; Zhang, Ming; Lee, Winson C C

    2013-06-01

    Many trans-tibial amputees could not tolerate long-distance walking. Lack of walking could explain for the increased cardiovascular diseases mortality rate. This study investigated the effects of long-distance walking (LDW) on socket-limb interface pressure, tactile sensitivity of the residual limb, and subjective feedbacks, which potentially identified the difficulties in LDW. Five male unilateral trans-tibial amputees walked on a level treadmill for a total of one hour at comfortable speed. Tactile sensitivity of the residual limb and socket-limb interface pressure during over-ground walking were measured before and after the treadmill walking. Modified Prosthesis Evaluation Questionnaires were also administered. After the treadmill walking, the socket-limb interface pressure and the tactile sensitivity at the popliteal depression area were significantly reduced. This corresponds well with the questionnaire results showing that the level of discomfort and pain of the residual limb did not increase. The questionnaire revealed that there were significant increases in fatigue level at the sound-side plantar flexors, which could lead to impaired dynamic stability. Fatigue of sound-side plantar-flexor was the main difficulty faced by the five subjects when walking long-distances. This finding might imply the importance of refining prosthetic components and rehabilitation protocols in reducing the muscle fatigue. • After long-distance walking (LDW) of the trans-tibal amputee subjects, there were significant increases in fatigue level at the plantar flexors. These might explain the reduced walking stability as perceived by the subjects. • LDW did not produce any problems in residual-limb comfort and pain feeling. These were in line with the significant reductions of socket-limb interface pressure and the tactile sensitivity at the popliteal depression after LDW. • Refinements of prosthetic components and rehabilitation protocols should be attempted to reduce the

  7. A 5-year comparison of marginal bone level following immediate loading of single-tooth implants placed in healed alveolar ridges and extraction sockets in the maxilla.

    Science.gov (United States)

    Berberi, Antoine N; Sabbagh, Joseph M; Aboushelib, Moustafa N; Noujeim, Ziad F; Salameh, Ziad A

    2014-01-01

    The aim of present investigation was to evaluate marginal bone level after 5-year follow-up of implants placed in healed ridges and fresh extraction sockets in maxilla with immediate loading protocol. Thirty-six patients in need of a single-tooth replacement in the anterior maxilla received 42 Astra Tech implants (Astra Tech Implant system™, Dentsply Implants, Mölndal, Sweden). Implants were placed either in healed ridges (group I) or immediately into fresh extraction sockets (group II). Implants were restored and placed into functional loading immediately by using a prefabricated abutment. Marginal bone level relative to the implant reference point was recorded at implant placement, crown cementation, 12, 36, and 60 months following loading using intra-oral radiographs. Measurements were made on the mesial and distal sides of each implant. Overall, two implants were lost from the group II, before final crown cementation: they were excluded from the study. The mean change in marginal bone loss (MBL) after implant placement was 0.26 ± 0.161 mm for 1 year, and 0.26 ± 0.171 mm for 3 years, and 0.21 ± 0.185 mm for 5 years in extraction sockets and was 0.26 ± 0.176 mm for 1 year and 0.21 ± 0.175 mm for 3 years, and 0.19 ± 0.172 mm for 5 years in healed ridges group. Significant reduction of marginal bone was more pronounced in implants inserted in healed ridges (P implant after cementation of the provisional (P immediately loaded implants placed either in extraction sockets or healed ridges were similar. Functional loading technique by using prefabricated abutment placed during the surgery time seems to maintain marginal bone around implant in both healed and fresh extraction sites.

  8. KINEMATICS AND DYNAMICS OF BALLS WHILE BEING POLISHED BETWEEN MISALIGNED DISKS IN DRIVEN SEPARATOR

    Directory of Open Access Journals (Sweden)

    K. G. Schetnikovich

    2007-01-01

    Full Text Available The paper contains description of tool design which is used for rough polishing of balls made of brittle materials. This tool consists of top disk, which is fi-eely set on pouring bearing of the separator shaft, and a bottom disk with elastic coating. Theoretical investigations of ball kinematics have permitted to determine an angular velocity of the balls in the machining zone, value and direction oi slipping speed with respect to the tool.it has been determined that even change of the position of bail rotation instantaneous axis relative to the separator is reached at equality of angular velocities of the bottom disk and the separator. When the top disk is freely set slipping speed is equal for all the balls of the machined lot. When the top disk is stationary slipping speed is significantly increasing however its value becomes variable and depends on ball distance to separator rotation axis.The presented equations of ball dynamics in the machining zone have made it possible to detennine a cohesive force with the bottom disk, frictional forces against the top disk and separator. Recommendations on selection of machining modes at initial and final stages of ball polishing are given in the paper.

  9. Fabrication and Study of Micro Monolithic Tungsten Ball Tips for Micro/Nano-CMM Probes

    Directory of Open Access Journals (Sweden)

    Ruijun Li

    2018-03-01

    Full Text Available Micro ball tips with high precision, small diameter, and high stiffness stems are required to measure microstructures with high aspect ratio. Existing ball tips cannot meet such demands because of their weak qualities. This study used an arc-discharge melting method to fabricate a micro monolithic tungsten ball tip on a tungsten stylus. The principles of arc discharge and surface tension phenomenon were introduced. The experimental setup was designed and established. Appropriate process parameters, such as impulse voltage, electro discharge time, and discharge gap were determined. Experimental results showed that a ball tip of approximately 60 µm in diameter with less than 0.6 µm roundness error and 0.6 µm center offset could be realized on a 100 µm-diameter tungsten wire. The fabricated micro ball tip was installed on a homemade probe, touched by high-precision gauge blocks in different directions. A repeatability of 41 nm (K = 2 was obtained. Several interesting phenomena in the ball-forming process were also discussed. The proposed method could be used to fabricate a monolithic probe ball tip, which is necessary for measuring microstructures.

  10. Development and acceptability testing of decision trees for self-management of prosthetic socket fit in adults with lower limb amputation.

    Science.gov (United States)

    Lee, Daniel Joseph; Veneri, Diana A

    2018-05-01

    The most common complaint lower limb prosthesis users report is inadequacy of a proper socket fit. Adjustments to the residual limb-socket interface can be made by the prosthesis user without consultation of a clinician in many scenarios through skilled self-management. Decision trees guide prosthesis wearers through the self-management process, empowering them to rectify fit issues, or referring them to a clinician when necessary. This study examines the development and acceptability testing of patient-centered decision trees for lower limb prosthesis users. Decision trees underwent a four-stage process: literature review and expert consultation, designing, two-rounds of expert panel review and revisions, and target audience testing. Fifteen lower limb prosthesis users (average age 61 years) reviewed the decision trees and completed an acceptability questionnaire. Participants reported agreement of 80% or above in five of the eight questions related to acceptability of the decision trees. Disagreement was related to the level of experience of the respondent. Decision trees were found to be easy to use, illustrate correct solutions to common issues, and have terminology consistent with that of a new prosthesis user. Some users with greater than 1.5 years of experience would not use the decision trees based on their own self-management skills. Implications for Rehabilitation Discomfort of the residual limb-prosthetic socket interface is the most common reason for clinician visits. Prosthesis users can use decision trees to guide them through the process of obtaining a proper socket fit independently. Newer users may benefit from using the decision trees more than experienced users.

  11. 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

  12. Ball Collision Experiments

    Science.gov (United States)

    Cross, R.

    2015-01-01

    Experiments are described on collisions between two billiard balls and between a bat and a ball. The experiments are designed to extend a student's understanding of collision events and could be used either as a classroom demonstration or for a student project.

  13. Error Analysis and Adaptive-Robust Control of a 6-DoF Parallel Robot with Ball-Screw Drive Actuators

    Directory of Open Access Journals (Sweden)

    Navid Negahbani

    2016-01-01

    Full Text Available Parallel kinematic machines (PKMs are commonly used for tasks that require high precision and stiffness. In this sense, the rigidity of the drive system of the robot, which is composed of actuators and transmissions, plays a fundamental role. In this paper, ball-screw drive actuators are considered and a 6-degree of freedom (DoF parallel robot with prismatic actuated joints is used as application case. A mathematical model of the ball-screw drive is proposed considering the most influencing sources of nonlinearity: sliding-dependent flexibility, backlash, and friction. Using this model, the most critical poses of the robot with respect to the kinematic mapping of the error from the joint- to the task-space are systematically investigated to obtain the workspace positional and rotational resolution, apart from control issues. Finally, a nonlinear adaptive-robust control algorithm for trajectory tracking, based on the minimization of the tracking error, is described and simulated.

  14. Comparison of Models for Ball Bearing Dynamic Capacity and Life

    Science.gov (United States)

    Gupta, Pradeep K.; Oswald, Fred B.; Zaretsky, Erwin V.

    2015-01-01

    Generalized formulations for dynamic capacity and life of ball bearings, based on the models introduced by Lundberg and Palmgren and Zaretsky, have been developed and implemented in the bearing dynamics computer code, ADORE. Unlike the original Lundberg-Palmgren dynamic capacity equation, where the elastic properties are part of the life constant, the generalized formulations permit variation of elastic properties of the interacting materials. The newly updated Lundberg-Palmgren model allows prediction of life as a function of elastic properties. For elastic properties similar to those of AISI 52100 bearing steel, both the original and updated Lundberg-Palmgren models provide identical results. A comparison between the Lundberg-Palmgren and the Zaretsky models shows that at relatively light loads the Zaretsky model predicts a much higher life than the Lundberg-Palmgren model. As the load increases, the Zaretsky model provides a much faster drop off in life. This is because the Zaretsky model is much more sensitive to load than the Lundberg-Palmgren model. The generalized implementation where all model parameters can be varied provides an effective tool for future model validation and enhancement in bearing life prediction capabilities.

  15. Soft tissue healing in alveolar socket preservation technique: histologic evaluations.

    Science.gov (United States)

    Pellegrini, Gaia; Rasperini, Giulio; Obot, Gregory; Farronato, Davide; Dellavia, Claudia

    2014-01-01

    After tooth extraction, 14 alveolar sockets were grafted with porous bovine bone mineral particles and covered with non-cross-linked collagen membrane (test group), and 14 alveolar sockets were left uncovered. At 5 and 12 weeks, microvascular density (MVD), collagen content, and amount of lymphocytes (Lym) T and B were analyzed in soft tissue. At 5 weeks, MVD was significantly lower and Lym T was significantly higher in tests than in controls (P healing process of the soft tissue.

  16. The Four-Ball Gyro and Motorcycle Countersteering

    Science.gov (United States)

    Galli, J. Ronald; Carroll, Bradley W.

    2017-04-01

    Most two-wheel motorcycle riders know that, at highway speeds, if you want to turn left you push on the left handlebar and pull on the right handlebar. This is called countersteering. Countersteering is counterintuitive since pushing left and pulling right when the front wheel is not spinning would turn the wheel to the right. All good motorcycle instructors teach countersteering but few understand the physics of why it works, even though there is considerable discussion about it among motorcycle riders. This paper gives a simplified explanation of gyroscopic precession and then applies this to the front wheel of a motorcycle using two steps: 1) explaining how the wheel's lean is initiated, and 2) explaining how the lean will cause the wheel to turn. To assist with this discussion and to demonstrate the conclusions, a "wheel" was constructed using copper pipe, a bicycle wheel hub, and one pound of lead in each of four "balls" at the end of the spokes (see Fig. 1).

  17. Dynamic analysis of double-row self-aligning ball bearings due to applied loads, internal clearance, surface waviness and number of balls

    Science.gov (United States)

    Zhuo, Yaobin; Zhou, Xiaojun; Yang, Chenlong

    2014-11-01

    In this paper, a three degrees of freedom (dof) model was established for a double-row self-aligning ball bearing (SABB) system, and was applied to study the dynamic behavior of the system during starting process and constant speed rotating process. A mathematical model was developed concerning stiffness and damping characteristics of the bearing, as well as three-dimensional applied load, rotor centrifugal force, etc. Balls and races were all considered as nonlinear springs, and the contact force between ball and race was calculated based on classic Hertzian elastic contact deformation theory and deformation compatibility theory. The changes of each ball's contact force and loaded angle of each row were taken into account. In order to solve the nonlinear dynamical equilibrium equations of the system, these equations were rewritten as differential equations and the fourth order Runge-Kutta method was used to solve the equations iteratively. In order to verify accuracy of the dynamical model and correctness of the numerical solution method, a kind of SABB-BRF30 was chosen for case studies. The effects of several important governing parameters, such as radial and axial applied loads, normal internal, inner and outer races waviness, and number of balls were investigated. These parametric studies led to a complete characterization of the shaft-bearing system vibration transmission. The research provided a theoretical reference for new type bearing design, shaft-bearing system kinetic analysis, optimal design, etc.

  18. Prosthetic limb sockets from plant-based composite materials.

    Science.gov (United States)

    Campbell, Andrew I; Sexton, Sandra; Schaschke, Carl J; Kinsman, Harry; McLaughlin, Brian; Boyle, Martin

    2012-06-01

    There is a considerable demand for lower limb prostheses globally due to vascular disease, war, conflict, land mines and natural disasters. Conventional composite materials used for prosthetic limb sockets include acrylic resins, glass and carbon fibres, which produce harmful gasses and dust in their manufacture. To investigate the feasibility of using a renewable plant oil-based polycarbonate-polyurethane copolymer resin and plant fibre composite, instead of conventional materials, to improve safety and accessibility of prosthetic limb manufacture. Experimental, bench research. Test pieces of the resin with a range of plant fibres (10.0% by volume) were prepared and tensile strengths were tested. Test sockets of both conventional composite materials and plant resin with plant fibres were constructed and tested to destruction. Combinations of plant resin and either banana or ramie fibres gave high tensile strengths. The conventional composite material socket and plant resin with ramie composite socket failed at a similar loading, exceeding the ISO 10328 standard. Both wall thickness and fibre-matrix adhesion played a significant role in socket strength. From this limited study we conclude that the plant resin and ramie fibre composite socket has the potential to replace the standard layup. Further mechanical and biocompatibility testing as well as a full economic analysis is required. Using readily sourced and renewable natural fibres and a low-volatile bio-resin has potential to reduce harm to those involved in the manufacture of artificial limb sockets, without compromising socket strength and benefitting clinicians working in poorer countries where safety equipment is scarce. Such composite materials will reduce environmental impact.

  19. Hyperbaric oxygen therapy in management of severe dry socket pain

    International Nuclear Information System (INIS)

    Abdellateef, Abdelamajeed; Elrefai, Jamil; AlJadid, Omar; Alabbadi, Amjad

    2009-01-01

    To assess the role and efficacy of hyperbaric oxygen therapy (HBOT) in the treatment of pain resulting from dry socket. From January 2006 to May 2007, 25 patients who had been diagnosed by the oral surgeon in the Dental Department of Princess Haya Hospital, Aqaba, Jordan with dry socket with severe intolerable pain, untreated with the classical treatments, were treated with HBOT. Fifteen patients (60%) were treated in a single HBOT session after which an almost complete resolution of pain took place, 7 patients (28%) were treated in 2 sessions and 3 patients (12%) needed 3 HBOT sessions to cure the pain. This preliminary study to assess the role of HBOT in the treatment of dry socket pain showed a great reduction of pain intensity of dry socket following administration of HBOT. (author)

  20. The ground stone components of drills in the ancient Near East: Sockets, flywheels, cobble weights, and drill bits

    Directory of Open Access Journals (Sweden)

    David Ilan

    2016-10-01

    Full Text Available Three types of drills are known from antiquity: the bow drill, the pump drill and the crank drill. Each type often included ground stone components - sockets, weights and flywheels. However, these components are inconspicuous; on their own they are almost never associated with drills. The result is that the drill is nearly invisible in many assemblages, particularly those of the proto-historic and historic periods, from the Chalcolithic through to late antiquity. In this article I focus on the identification of the possible ground stone components of each of these drill types. The means by which these components were attached or applied to the drill shaft is examined and the way that they related to the rotary motion of drills is laid out. I briefly discuss the historical development of each type, referencing more detailed studies, where available. This study should be seen as a prelude to a more comprehensive study that will test hypotheses by means of experiment and catalogue more completely and precisely the ground stone components of drills that have been unidentified or misidentified in archaeological contexts.

  1. Punjab Ball Menu

    OpenAIRE

    Hobday, E, fl. 1905, artist

    2003-01-01

    A photograph of the exterior of a menu from the 'Punjab Ball'. The menu is decorated on both the inside and outside with illustrations by 'E. Hobday'. Inside the menu, in pen, is written: 'Lahore, Ball in Montgomery Hall, Nov 30th. 1905'.

  2. Advancing description and explanation in clinical linguistics: a legacy of Martin J. Ball.

    Science.gov (United States)

    Damico, Jack S; Damico, Holly L; Nelson, Ryan L

    2011-11-01

    This article asserts the importance of explication of order and disorder in language as a privileged objective of clinical linguistics and service delivery and reviews the contributions of Martin Ball in advancing this agenda.

  3. Petrography and microanalysis of Pennsylvanian coal-ball concretions (Herrin Coal, Illinois Basin, USA): Bearing on fossil plant preservation and coal-ball origins

    Science.gov (United States)

    Siewers, Fredrick D.; Phillips, Tom L.

    2015-11-01

    Petrographic analyses of 25 coal balls from well-studied paleobotanical profiles in the Middle Pennsylvanian Herrin Coal (Westphalian D, Illinois Basin) and five select coal balls from university collections, indicate that Herrin Coal-ball peats were permineralized by fibrous and non-fibrous carbonates. Fibrous carbonates occur in fan-like to spherulitic arrays in many intracellular (within tissue) pores, and are best developed in relatively open extracellular (between plant) pore spaces. Acid etched fibrous carbonates appear white under reflected light and possess a microcrystalline texture attributable to abundant microdolomite. Scanning electron microscopy, X-ray diffraction, and electron microprobe analysis demonstrate that individual fibers have a distinct trigonal prism morphology and are notable for their magnesium content (≈ 9-15 mol% MgCO3). Non-fibrous carbonates fill intercrystalline spaces among fibers and pores within the peat as primary precipitates and neomorphic replacements. In the immediate vicinity of plant cell walls, non-fibrous carbonates cut across fibrous carbonates as a secondary, neomorphic phase attributed to coalification of plant cell walls. Dolomite occurs as diagenetic microdolomite associated with the fibrous carbonate phase, as sparite replacements, and as void-filling cement. Maximum dolomite (50-59 wt.%) is in the top-of-seam coal-ball zone at the Sahara Mine, which is overlain by the marine Anna Shale. Coal-ball formation in the Herrin Coal began with the precipitation of fibrous high magnesium calcite. The trigonal prism morphology of the carbonate fibers suggests rapid precipitation from super-saturated, meteoric pore waters. Carbonate precipitation from marine waters is discounted on the basis of stratigraphic, paleobotanical, and stable isotopic evidence. Most non-fibrous carbonate is attributable to later diagenetic events, including void-fill replacements, recrystallization, and post-depositional fracture fills. Evidence

  4. Review of the dynamic behaviour of sports balls during normal and oblique impacts

    Science.gov (United States)

    Haron, Muhammad Adli; Jailani, Azrol; Abdullah, Nik Ahmad Faris Nik; Ismail, Rafis Suizwan; Rahim, Shayfull Zamree Abd; Ghazali, Mohd Fathullah

    2017-09-01

    In this paper are review of impact experiment to study the dynamic behaviour of sports ball during oblique and normal impacts. In previous studies, the investigation was done on the dynamic behaviour of a sports ball during oblique and normal impacts from experimental, numerical, and theoretical viewpoints. The experimental results are analysed and compared with the theories, in order to understand the dynamics behaviours based on the phenomenological occurrence. Throughout the experimental studies previously, there are results of dynamics behaviours examined by many researchers such as the coefficient of restitution, tangential coefficient, local deformation, dynamic impact force, contact time, angle of impact (inbound and rebound), spin rate of the ball, ball stiffness and damping coefficient which dependable of the initial or impact velocity.

  5. Revisiting the gravitino dark matter and baryon asymmetry from Q-ball decay in gauge mediation

    Energy Technology Data Exchange (ETDEWEB)

    Kasuya, Shinta, E-mail: kasuya@kanagawa-u.ac.jp [Department of Mathematics and Physics, Kanagawa University, Kanagawa 259-1293 (Japan); Max-Planck-Institut für Kernphysik, PO Box 103980, 69029 Heidelberg (Germany); Kawasaki, Masahiro [Institute for Cosmic Ray Research, the University of Tokyo, Chiba 277-8582 (Japan); Kavli Institute for the Physics and Mathematics of the Universe (WPI), Todai Institutes for Advanced Study, the University of Tokyo, Chiba 277-8582 (Japan); Yamada, Masaki [Institute for Cosmic Ray Research, the University of Tokyo, Chiba 277-8582 (Japan)

    2013-10-07

    We reconsider the Q-ball decay and reinvestigate the scenario that the amount of the baryons and the gravitino dark matter is naturally explained by the decay of the Q balls in the gauge-mediated SUSY breaking. We refine the decay rates into baryons, NLSPs, and gravitinos, and estimate their branching ratios based on the consideration of Pauli blocking. We obtain a smaller branching into gravitinos than the previous estimate, and the NLSPs are more produced by the Q-ball decay. However, the efficient annihilations of NLSPs occur afterward so that their abundance does not spoil the successful BBN and they only produce negligible amount of the gravitinos to the dark matter density by their decay. In this way, we find that the scenario with the direct production of the gravitino dark matter from the Q-ball decay works naturally.

  6. Simulation and Analysis of One-time Forming Process of Automobile Steering Ball Head

    Science.gov (United States)

    Shi, Peicheng; Zhang, Xujun; Xu, Zengwei; Zhang, Rongyun

    2018-03-01

    Aiming at the problems such as large machining allowance, low production efficiency and material waste during die forging of ball pin, the cold extrusion process of ball head was studied and the analog simulation of the forming process was carried out by using the finite element analysis software DEFORM-3D. Through the analysis of the equivalent stress strain, velocity vector field and load-displacement curve, the flow regularity of the metal during the cold extrusion process of ball pin was clarified, and possible defects during the molding were predicted. The results showed that this process could solve the forming problem of ball pin and provide theoretical basis for actual production of enterprises.

  7. Influence of Tennis Racquet Kinematics on Ball Topspin Angular Velocity and Accuracy during the Forehand Groundstroke.

    Science.gov (United States)

    Kwon, Sunku; Pfister, Robin; Hager, Ronald L; Hunter, Iain; Seeley, Matthew K

    2017-12-01

    Forehand groundstroke effectiveness is important for tennis success. Ball topspin angular velocity (TAV) and accuracy are important for forehand groundstroke effectiveness, and have been extensively studied, previously; despite previous, quality studies, it was unclear whether certain racquet kinematics relate to ball TAV and shot accuracy during the forehand groundstroke. This study evaluated potential relationships between (1) ball TAV and (2) forehand accuracy, and five measures of racquet kinematics: racquet head impact angle (i.e., closed or open face), horizontal and vertical racquet head velocity before impact, racquet head trajectory (resultant velocity direction, relative to horizontal) before impact, and hitting zone length (quasi-linear displacement, immediately before and after impact). Thirteen collegiate-level tennis players hit forehand groundstrokes in a biomechanics laboratory, where racquet kinematics and ball TAV were measured, and on a tennis court, to assess accuracy. Correlational statistics were used to evaluate potential relationships between racquet kinematics, and ball TAV (mixed model) and forehand accuracy (between-subjects model; α = 0.05). We observed an average (1) racquet head impact angle, (2) racquet head trajectory before impact, relative to horizontal, (3) racquet head horizontal velocity before impact, (4) racquet head vertical velocity before impact, and (5) hitting zone length of 80.4 ± 3.6˚, 18.6 ± 4.3˚, 15.4 ± 1.4 m·s -1 , 6.6 ± 2.2 m·s -1 , and 79.8 ± 8.6 mm, respectively; and an average ball TAV of 969 ± 375 revolutions per minute. Only racquet head impact angle and racquet head vertical velocity, before impact, significantly correlated with ball TAV (p ball TAV is associated with a more closed racquet head impact angle (ranging from 70 to 85˚, relative to the ground) and increased racquet head vertical velocity before impact.

  8. 48 CFR 225.7009 - Restriction on ball and roller bearings.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Restriction on ball and roller bearings. 225.7009 Section 225.7009 Federal Acquisition Regulations System DEFENSE ACQUISITION... roller bearings. ...

  9. Tar ball frequency data and analytical results from a long-term beach monitoring program.

    Science.gov (United States)

    Owens, Edward H; Mauseth, Gary S; Martin, Colin A; Lamarche, Alain; Brown, John

    2002-08-01

    Following the spill of fuel oils from the New Carissa in February 1999, approximately 300 km of beaches on the Pacific coast of North America were surveyed. A long-term observation program focused on the documentation of stranded tar balls in the vicinity of the spill site. Systematic beach surveys which were conducted over the period March 1999 to April 2001 and semi-logarithmic scale, time-series plots proved the most useful format for identifying trends. Beach monitoring continued through to August 2001. by which time 212 tar balls had been analyzed by GC/MS for their chemical characteristics. The samples of tar balls collected between February 1999 and August 2001 were qualitatively compared with New Carissa source oils (NCSO) and 101 (48%) were not consistent with NSCO. The presence of tar balls that are not related to an incident can confound attempts to define cleanup or endpoint criteria and to assess possible injury to natural resources.

  10. Eddy Current Model of Ball Lightning

    OpenAIRE

    Shelton, J. D.

    2011-01-01

    Eddy Current Model of Ball Lightning Calculations show that high-energy ball lightning may consist of a ball of plasma containing a large circular electric current arising as an eddy current generated by lightning. Synthetic ball lightning might serve as a method of plasma confinement for purposes of nuclear fusion. In this paper, three articles concerning ball lightning and the related phenomenon of large ball lightning are combined to provide insight into this rarely glimpsed occurrence.

  11. Saipan and Joint Operations

    Science.gov (United States)

    1990-02-12

    Dyar , Vice Admiral,. IhX AmehbIiaaz Qj t Cong~3rL The Story 21 Admrml icmn fln .’:jl Tu~ ~rner. P. 923. 2. Joter A. Italy and Philip A. Crowi, Jb aig n...officers to attend the Naval War College in 1920 . Following the War College he was in the War Plans Division of Naval Operations and the Joint Army

  12. Quartic Rational Said-Ball-Like Basis with Tension Shape Parameters and Its Application

    Directory of Open Access Journals (Sweden)

    Yuanpeng Zhu

    2014-01-01

    Full Text Available Four new quartic rational Said-Ball-like basis functions, which include the cubic Said-Ball basis functions as a special case, are constructed in this paper. The new basis is applied to generate a class of C1 continuous quartic rational Hermite interpolation splines with local tension shape parameters. The error estimate expression of the proposed interpolant is given and the sufficient conditions are derived for constructing a C1 positivity- or monotonicity- preserving interpolation spline. In addition, we extend the quartic rational Said-Ball-like basis to a triangular domain which has three tension shape parameters and includes the cubic triangular Said-Ball basis as a special case. In order to compute the corresponding patch stably and efficiently, a new de Casteljau-type algorithm is developed. Moreover, the G1 continuous conditions are deduced for the joining of two patches.

  13. Relationships between fast bowling technique and ball release speed in cricket.

    Science.gov (United States)

    Worthington, Peter J; King, Mark A; Ranson, Craig A

    2013-02-01

    The aim of this study was to identify the key aspects of technique that characterize the fastest bowlers. Kinematic data were collected for 20 elite male fast bowlers with 11 kinematic parameters calculated, describing elements of fast bowling technique that have previously been linked to ball release speed. Four technique variables were identified as being the best predictors of ball release speed, explaining 74% of the observed variation in ball release speed. The results indicate that the fastest bowlers have a quicker run-up and maintain a straighter knee throughout the front foot contact phase. The fastest bowlers were also observed to exhibit larger amounts of upper trunk flexion up to ball release and to delay the onset of arm circumduction. This study identifies those technique variables that best explain the differences in release speeds among fast bowlers. These results are likely to be useful in both the coaching and talent identification of fast bowlers.

  14. Ball Speed and Release Consistency Predict Pitching Success in Major League Baseball.

    Science.gov (United States)

    Whiteside, David; Martini, Douglas N; Zernicke, Ronald F; Goulet, Grant C

    2016-07-01

    Whiteside, D, Martini, DN, Zernicke, RF, and Goulet, GC. Ball speed and release consistency predict pitching success in Major League Baseball. J Strength Cond Res XX(X): 000-000, 2015-This study aimed to quantify how ball flight kinematics (i.e., ball speed and movement), release location, and variations therein relate to pitching success in Major League Baseball (MLB). One hundred ninety starting MLB pitchers met the inclusion criteria for this study. Ball trajectory information was collected for 76,000 pitches and inserted into a forward stepwise multiple regression model, which examined how (a) pitch selection, (b) ball speed, (c) ball movement (horizontal and lateral), (d) release location (horizontal and lateral), (e) variation in pitch speed, (f) variation in ball movement, and (g) variation in release location related to pitching success (as measured by fielding independent pitching-FIP). Pitch speed, release location variability, variation in pitch speed, and horizontal release location were significant predictors of FIP and, collectively, accounted for 24% of the variance in FIP. These findings suggest that (a) maximizing ball speed, (b) refining a consistent spatial release location, and (c) using varied pitch speeds should be primary foci for the pitching coach. However, between-pitcher variations underline how training interventions should be administered at the individual level, with consideration given to the pitcher's injury history. Finally, despite offering significant predictors of success, these three factors explained only 22% of the variance in FIP and should not be considered the only, or preeminent, indicators of a pitcher's effectiveness. Evidently, traditional pitching metrics only partly account for a pitcher's effectiveness, and future research is necessary to uncover the remaining contributors to success.

  15. Longitudinal joint specifications and performance.

    Science.gov (United States)

    2012-08-01

    Deterioration of longitudinal joints is widely recognized as one of the major factors contributing to failure of asphalt pavements. Finding : ways to improve the durability of longitudinal joints will lead to improved service lives and lower life cyc...

  16. Joint and Soft Tissue Injections

    Science.gov (United States)

    ... Injections Joint and Soft Tissue Injections Share Print What is a joint and soft tissue injection? Joint and soft tissue injections are shots ... many injections do I need and how often? What restrictions do I have after an ... tissue injection, treatment April 1, 2004 Copyright © American Academy ...

  17. Effects and mechanism of ball milling on torrefaction of pine sawdust.

    Science.gov (United States)

    Gong, Chunxiao; Huang, Jing; Feng, Chen; Wang, Guanghui; Tabil, Lope; Wang, Decheng

    2016-08-01

    The effects and mechanism of ball milling on the torrefaction process were studied. Ball- and hammer-milled (screen size 1mm) pine sawdust samples were torrefied at three temperatures (230, 260, and 290°C) and two durations (30 and 60min) to investigate into their torrefaction behavior and physicochemical properties. The results showed that, under identical torrefaction conditions, torrefied ball-milled pine sawdust had a higher carbon content and fixed carbon, and lower hydrogen and oxygen contents than torrefied hammer-milled pine sawdust. Torrefied ball-milled pine sawdust produced lower mass and energy yields, but higher heating values than torrefied hammer-milled pine sawdust. Ball milling destroyed the crystalline structure of cellulose and thus reduced the thermal stability of hemicellulose, cellulose, and lignin, causing them to degrade at relatively lower temperatures. In conclusion, biomass pretreated with a combination of ball milling and torrefaction has the potential to produce an alternative fuel to coal. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. Optical, physical, and chemical properties of tar balls observed during the Yosemite Aerosol Characterization Study

    Science.gov (United States)

    Hand, J. L.; Malm, W. C.; Laskin, A.; Day, D.; Lee, T.; Wang, C.; Carrico, C.; Carrillo, J.; Cowin, J. P.; Collett, J.; Iedema, M. J.

    2005-11-01

    The Yosemite Aerosol Characterization Study of summer 2002 (YACS) occurred during an active fire season in the western United States and provided an opportunity to investigate many unresolved issues related to the radiative effects of biomass burning aerosols. Single particle analysis was performed on field-collected aerosol samples using an array of electron microscopy techniques. Amorphous carbon spheres, or "tar balls," were present in samples collected during episodes of high particle light scattering coefficients that occurred during the peak of a smoke/haze event. The highest concentrations of light-absorbing carbon from a dual-wavelength aethalometer (λ = 370 and 880 nm) occurred during periods when the particles were predominantly tar balls, indicating they do absorb light in the UV and near-IR range of the solar spectrum. Closure experiments of mass concentrations and light scattering coefficients during periods dominated by tar balls did not require any distinct assumptions of organic carbon molecular weight correction factors, density, or refractive index compared to periods dominated by other types of organic carbon aerosols. Measurements of the hygroscopic behavior of tar balls using an environmental SEM indicate that tar balls do not exhibit deliquescence but do uptake some water at high (˜83%) relative humidity. The ability of tar balls to efficiently scatter and absorb light and to absorb water has important implications for their role in regional haze and climate forcing.

  19. Beyond the socket: NUMA-aware GPUs

    OpenAIRE

    Ugljesa, Milic; Villa, Oreste; Bolotin, Evgeny; Arunkumar, Akhil; Ebrahimi, Eiman; Jaleel, Aamer; Ramirez, Alex; Nellans, David

    2017-01-01

    GPUs achieve high throughput and power efficiency by employing many small single instruction multiple thread (SIMT) cores. To minimize scheduling logic and performance variance they utilize a uniform memory system and leverage strong data parallelism exposed via the programming model. With Moore's law slowing, for GPUs to continue scaling performance (which largely depends on SIMT core count) they are likely to embrace multi-socket designs where transistors are more readily available. However...

  20. 21 CFR 888.3680 - Shoulder joint glenoid (hemi-shoulder) metallic cemented prosthesis.

    Science.gov (United States)

    2010-04-01

    ... cemented prosthesis. 888.3680 Section 888.3680 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF... Shoulder joint glenoid (hemi-shoulder) metallic cemented prosthesis. (a) Identification. A shoulder joint glenoid (hemi-shoulder) metallic cemented prosthesis is a device that has a glenoid (socket) component...

  1. Determination of the spatial movement of the temporomandibular joints (tmj joint heads in patients with muscle and joint dysfunction according to computed tomography (ct

    Directory of Open Access Journals (Sweden)

    Аркадий Максимович Боян

    2015-11-01

    heads relative to articular tubercle (at p≤0,005 were detected in all patients with MJD. After treatment and removal of the symptoms of disease the parameters of mandibular heads in socket approached to the normal ones (at p≤0,005. The use of CT for spatial determination of mandibular joint heads can be considered as an additional objective method of diagnostics for successful treatment of patients with TMJ MJD

  2. Morphomechanics of the humero-ulnar joint: II. Concave incongruity determines the distribution of load and subchondral mineralization.

    Science.gov (United States)

    Eckstein, F; Merz, B; Müller-Gerbl, M; Holzknecht, N; Pleier, M; Putz, R

    1995-11-01

    A deeper joint socket (concave incongruity) is found at most angles of flexion of the humero-ulnar joint and maintained over a wide range of physiological loading. It is, however, unclear how far this incongruity affects the distribution of load and subchondral mineralization of this joint as compared with a congruous configuration. Two nonlinear, axisymmetrical finite element models with two cartilage layers were constructed, one congruous and one incongruous, with a joint space of realistic magnitude. The distribution of subchondral mineralization was determined by computed tomography osteoabsorptiometry in the same six specimens that were investigated in the first part of the study, and compared with the biomechanical data obtained there and the predictions of the models. In the congruous case, the center of the socket is highly loaded, whereas the periphery does not experience mechanical stimulation. A central bone density maximum is predicted. With concave incongruity the position of the contact areas shifts from the joint margin towards the center as the load increases, and the peak stresses are considerably lower. A bicentric ventro-dorsal distribution pattern of subchondral mineralization is predicted, and this is actually found in the six specimens. Concave incongruity is shown to determine load transmission and subchondral mineralization of the humero-ulnar joint. It is suggested that this shape leads to a more even distribution of stress, provides intermittent stimulation of the cartilaginous tissue, and has beneficial effects on the metabolism, nutrition, and lubrication of the articular cartilage during cyclic loading.

  3. FOUR BALL BEST BALL 1

    Directory of Open Access Journals (Sweden)

    Geoff Pollard

    2010-03-01

    Full Text Available In this paper a four-ball-best-ball (4BBB model for pairs of golf players is set up. The 4BBB match-play scoring system is seen to satisfy a basic requirement of fairness. It is shown that it is not strictly possible to rate individual players as 4BBB players. However, a (reasonably broad class of individual players is identified such that it is possible to rate them individually as 4BBB players. The capacity of an individual to play birdies is seen to be a very important determinant in being a successful member of a 4BBB pair, but there are other minor factors as well. Consideration is given to equal and unequal 4BBB pairs. The transitive law is seen to apply for 4BBB pairs. Thus, if pair A is better than pair B, and pair B is better than pair C, then pair A must be better than pair C. Correspondingly, if pair A is equal to pair B, and pair B is equal to pair C, then pair A is equal to pair C. Consideration is given to some strategic issues in 4BBB match-play golf. For example, the conditions under which a player should take a greater risk and have a higher probability of obtaining a bogie in order to achieve a higher probability of scoring a birdie, are determined. Also, the conditions under which a player, noting that his partner is about to have a ‘bad’ hole and score only a par or a bogie, should ‘play safe’, are determined. Thirdly, players who can interact in certain ways are seen to have an advantage over those pairs that cannot do this. Finally, one pair’s optimal strategy when they see that their opponents are about to score a par or a bogie, but not a birdie, is analyzed

  4. The Development of Smart Home System for Controlling and Monitoring Energy Consumption using WebSocket Protocol

    Science.gov (United States)

    Witthayawiroj, Niti; Nilaphruek, Pongpon

    2017-03-01

    Energy consumption especially electricity is considered one of the most serious problems in households these days. It is because the amount of electricity consumed is more than the amount that people actually need. This means that there is an overusing which resulted from the inconvenience of moving to the switch to turn off the light or any appliances and it is often that closing the light is forgettable, for instance; in addition, there are no tools for monitoring how much energy that is consumed in residents. From this, it can be easily seen that people are having a problem in energy usage monitor and control. There are two main objectives of this study including 1) creating the communication framework among server, clients and devices, and 2) developing the prototype system that try to solve the mentioned problems which gives the user an opportunity to know the amount of electricity they have used in their houses and also the ability to turn appliances on and off through the Internet on smart devices such as smart phones and tablets that support Android platform or any web browser. Raspberry Pi is used as a microcontroller and the data is transferred to the smart device by WebSocket protocol which is strongly recommended for real-time communication. The example features on the device’s screen are user management, controlling and monitoring of appliances. The result expresses that the system is very effective and not difficult to use from users’ satisfaction. However, current sensors may be used for a more accurate electricity measurement and Wi-Fi module for more appliances to calculate its power in the future.

  5. The Osteogenesis Effect and Underlying Mechanisms of Local Delivery of gAPN in Extraction Sockets of Beagle Dogs

    Directory of Open Access Journals (Sweden)

    Hongcheng Hu

    2015-10-01

    Full Text Available A plastic and biodegradable bone substitute consists of poly (l-lactic-co-glycolic acid and 30 wt % β-tricalcium phosphate has been previously fabricated, but its osteogenic capability required further improvement. We investigated the use of globular adiponectin (gAPN as an anabolic agent for tissue-engineered bone using this scaffold. A qualitative analysis of the bone regeneration process was carried out using μCT and histological analysis 12 weeks after implantation. CBCT (Cone Beam Computed Tomography superimposition was used to characterise the effect of the different treatments on bone formation. In this study, we also explored adiponectin’s (APN influence on primary cultured human jaw bone marrow mesenchymal stem cells gene expressions involved in the osteogenesis. We found that composite scaffolds loaded with gAPN or bone morphogenetic protein 2 (BMP2 exhibited significantly increased bone formation and mineralisation following 12 weeks in the extraction sockets of beagle dogs, as well as enhanced expression of osteogenic markers. In vitro investigation revealed that APN also promoted osteoblast differentiation of primary cultured human jaw bone marrow mesenchymal stem cells (h-JBMMSCs, accompanied by increased activity of alkaline phosphatase, greater mineralisation, and production of the osteoblast-differentiated genes osteocalcin, bone sialoprotein and collagen type I, which was reversed by APPL1 siRNA. Therefore, the composite scaffold loaded with APN exhibited superior activity for guided bone regeneration compared with blank control or Bio-Oss® (a commercially available product. The composite scaffold with APN has significant potential for clinical applications in bone tissue engineering.

  6. Plasma theory of ball lightning

    Energy Technology Data Exchange (ETDEWEB)

    Ostapenko, V.I.; Tolpygo, K.B.

    1984-02-01

    The high-energy density inside the ball lightning is due to existence of intense plasma oscillations and high kinetic and potential energy of electron gas which form a pulsating ball vibrating relative to the nearly stationary ionic ball. At sublight velocities of electrons one can neglect the processes of their scattering and recombination. One obtains a relation between parameters of the plasma ball from the condition of equality of excess pressure of ions and that of Madelung forces. The high lifetime of the ball lighting is connected with small Landau damping for the longest wave vibrations.

  7. 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.

  8. Alveolar Ridge Preservation Using Allografts and Dense Polytetrafluoroethylene Membranes With Open Membrane Technique in Unhealthy Extraction Socket.

    Science.gov (United States)

    Cheon, Gi-Beom; Kang, Kyung Lhi; Yoo, Mi-Kyung; Yu, Jeoung-A; Lee, Dong-Woon

    2017-08-01

    We evaluated the effectiveness of the open membrane technique using a high-density polytetrafluoroethylene (dPTFE) membrane with freeze-dried bone allografts in damaged sockets for alveolar ridge preservation (ARP). This retrospective study included 26 sites from 20 patients who had received ARP for the placement of dental implants. ARP was conducted using dPTFE membrane with allografts on the day of extraction without primary closure. When the membrane was removed after 4 weeks, the newly formed reddish tissue at the grafted site was checked (first outcome, clinical evaluation). Four months after membrane removal, a core biopsy was performed from the center of the grafted site before implant placement (second outcome, histomorphometric evaluation). Radiographic measurements of alveolar bone changes between implant prosthesis delivery and the 1-year follow-up were obtained (third outcome, radiographic evaluation). A total of 23 sites from 18 patients had no complications during the follow-up period. Three sites from two patients were excluded because of early membrane removal. Newly formed reddish tissue was found at 15 sites, and partially formed tissue was found at 8 sites. Although we were unable to harvest bone core from all sites, histomorphometric analysis in 11 patients indicated that the mean area of new bone was 28.48% ± 6.60%, that of the remaining graft particle was 27.68% ± 9.18%, and that of fibrous tissue was 43.84% ± 6.98%. The mean loss of marginal bone was 0.13 ± 0.06 mm at the mesial area and 0.15 ± 0.06 mm at the distal area, as assessed using radiographic evaluations. The results of this nonrandomized study suggest that this technique may be an appropriate procedure for ARP. Further studies with a control group and more subjectives can be designed based on this study.

  9. Determination of Parachute Joint Factors using Seam and Joint Testing

    Science.gov (United States)

    Mollmann, Catherine

    2015-01-01

    This paper details the methodology for determining the joint factor for all parachute components. This method has been successfully implemented on the Capsule Parachute Assembly System (CPAS) for the NASA Orion crew module for use in determining the margin of safety for each component under peak loads. Also discussed are concepts behind the joint factor and what drives the loss of material strength at joints. The joint factor is defined as a "loss in joint strength...relative to the basic material strength" that occurs when "textiles are connected to each other or to metals." During the CPAS engineering development phase, a conservative joint factor of 0.80 was assumed for each parachute component. In order to refine this factor and eliminate excess conservatism, a seam and joint testing program was implemented as part of the structural validation. This method split each of the parachute structural joints into discrete tensile tests designed to duplicate the loading of each joint. Breaking strength data collected from destructive pull testing was then used to calculate the joint factor in the form of an efficiency. Joint efficiency is the percentage of the base material strength that remains after degradation due to sewing or interaction with other components; it is used interchangeably with joint factor in this paper. Parachute materials vary in type-mainly cord, tape, webbing, and cloth -which require different test fixtures and joint sample construction methods. This paper defines guidelines for designing and testing samples based on materials and test goals. Using the test methodology and analysis approach detailed in this paper, the minimum joint factor for each parachute component can be formulated. The joint factors can then be used to calculate the design factor and margin of safety for that component, a critical part of the design verification process.

  10. Effect of Diode Laser on Healing of Tooth Extraction Socket: An Experimental Study in Rabbits.

    Science.gov (United States)

    Hamad, Shehab Ahmed; Naif, Jandar S; Abdullah, Mahdi A

    2016-09-01

    To evaluate the effect of low-level laser therapy on healing of extracted tooth socket of healthy rabbits. The sample of this study was 20 male rabbits of 2-2.5 kg weight with age range of 8-12 months. Right and left lower first premolar teeth were extracted. The extraction sockets of lower right first premolar were irradiated with 0.9 W gallium-aluminum-arsenide (GaAlAs) diode laser for 5 min, immediately after extraction and then every 72 h for the next 12 days. The extraction socket of left side were not exposed to laser and served as a control. The animals were sacrificed after 7, 14, 30 and 45 days and the experimental and control sockets were removed from the harvested mandibles and prepared for haematoxylin and eosin staining and Masson's stain. The prepared slides were examined under light microscope for histological and histomorphometric examination. The histological examination showed that diode laser-treated sockets demonstrated early formed new bone with faster maturation of primary bone to secondary bone as compared to non-treated control sockets. Histomorphometric analysis revealed a statistically significant increase in the density and volume of trabecular bone in laser-treated sockets than control sockets. Diode laser application to tooth extraction socket has a positive effect on bone formation.

  11. Flapless Postextraction Socket Implant Placement, Part 2: The Effects of Bone Grafting and Provisional Restoration on Peri-implant Soft Tissue Height and Thickness- A Retrospective Study.

    Science.gov (United States)

    Chu, Stephen J; Salama, Maurice A; Garber, David A; Salama, Henry; Sarnachiaro, Guido O; Sarnachiaro, Evangelina; Gotta, Sergio Luis; Reynolds, Mark A; Saito, Hanae; Tarnow, Dennis P

    2015-01-01

    This article presents the results of evaluating the changes in peri-implant soft tissue dimensions associated with immediate implant placement into anterior postextraction sockets for four treatment groups: no BGPR (no bone graft, no provisional restoration), PR (no bone graft, provisional restoration), BG (bone graft, no provisional restoration), and BGPR (bone graft, provisional restoration). The vertical distance of the peri-implant soft tissue was greater for grafted sites than for nongrafted ones (2.72 mm vs 2.29 mm, P provisional restorations compared to sites without them (2.81 mm vs 2.37 mm, P provisional restoration.

  12. Kicking Velocity and Effect on Match Performance When using a Smaller, Lighter Ball in Women's Football.

    Science.gov (United States)

    Andersen, T B; Krustrup, P; Bendiksen, M; Orntoft, C O; Randers, M B; Pettersen, S A

    2016-11-01

    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) (26.5±0.5 vs. 25.1±0.5 m·s -1 , p0.05), blood lactate (90 min: 4.7±1.7 and 4.0±1.7 mmol·l -1 ; p>0.05), total distance covered (10.6±0.9 and 10.4±0.8 km; p>0.05), intense running (>16 km/h) (2.08±0.42 and 1.94±0.38 km; p>0.05) and match-induced decrement in Yo-Yo IR1 performance (28 vs. 31%, respectively, pball types, and there was no difference in passing success rate (NB: 68±1% and SB: 68±1%, p>0.05). In conclusion, high-level adult female footballers had a higher kicking speed when using a smaller, lighter ball, but no differences were observed during match-play with the 2 ball types in respect of technical-tactical and physical match performance. The physical loading was high for the players when playing with both ball types. © Georg Thieme Verlag KG Stuttgart · New York.

  13. Acquisition and reduction of data obtained from Tank 101-SY in-situ ball rheometer

    International Nuclear Information System (INIS)

    Shepard, C.L.; Chieda, M.A.; Kirihara, L.J.

    1994-12-01

    Development of the ball rheometer to measure rheological properties and density of the waste in Hanford Tank 241-SY-101 will be completed around September 1994. Since the ball rheometer project began, a mixer pump has been installed in this tank, and by all accounts this pump has been very successful at mitigating the flammable gas problem associated with Tank 101-SY. Present plans now call for the use of mixer pumps in several other tanks. The ball rheometer will serve as a diagnostic tool for judging the effectiveness of mixing in Tank 101-SY and others and will be one of few in-situ probes available for diagnostic measurements. The in-situ data collection strategy and the methods of data analysis and reduction are presented in this final report concerning this instrument. It is believed that a generalized Bingham fluid model (Herschel-Bulkley fluid model) may be useful for describing at least some of the waste contained in Tank 101-SY, and data obtained in the tank will initially be reduced using this fluid model. The single largest uncertainty in the determination of the drag force on the ball is the drag force which will be experienced by the cable attached to the ball. This drag can be a substantial fraction of the total drag when the ball is deep within the tank. Careful accounting of the cable drag will be important in the reduction of the data. The data collection strategy allows the determination of the waste fluid rheology both in the undisturbed state and after it has been disturbed by the ball. Fluid density will be measured at regular intervals

  14. Acquisition and reduction of data obtained from tank 101-SY in-situ ball rheometer

    International Nuclear Information System (INIS)

    Shepard, C.L.; Chieda, M.A.; Kirihara, L.J.; Phillips, J.R.; Shekarriz, A.; Terrones, G.; Abbott, J.; Unal, C.; Pasamehmetoglu, K.O.; Graham, A.

    1995-02-01

    Development of the ball rheometer to measure rheological properties and density of the waste in Hanford Tank 241-SY-101 will be completed around September 1994. This instrument is expected to provide the first-of-its-kind in-situ measurements of the fluid properties of the waste contained within this tank. A mixer pump has been installed in this tank, and this pump has been very successful at mitigating the flammable gas problem associated with Tank 101-SY. The ball rheometer will serve as a diagnostic tool for judging the effectiveness of mixing in Tank 101-SY and others and will be one of few in-situ probes available for diagnostic measurements. Based on experiments performed at Los Alamos National Laboratory and Pacific Northwest Laboratory, it is believed that a generalized Bingham fluid model (Herschel-Bulkley fluid model) may be useful for describing at least some of the waste contained in Tank 101-SY, and data obtained in the tank will initially be reduced using this fluid model. The single largest uncertainty in the determination of the drag force on the ball is the drag force which will be experienced by the cable attached to the ball. This drag can be a substantial fraction of the total drag when the ball is deep within the tank. It is expected that the fluid properties may be history dependent, thus rheological properties of the undisturbed fluid may be different from the same properties after the fluid has been disturbed by passage of the ball. The data collection strategy allows the determination of the waste fluid rheology both in the undisturbed state and after it has been disturbed by the ball. Unlike the rheological parameters, measurement of density requires no model for its interpretation; however, the effects of yield stress may need to be accounted for. This measurement can be made with fairly good accuracy and may provide the most useful data in determination of mixer pump effectiveness

  15. 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.)

  16. A comparison of polyethylene wear between cobalt-chrome ball heads and alumina ball heads after total hip arthroplasty: a 10-year follow-up.

    Science.gov (United States)

    Wang, Shijun; Zhang, ShuDong; Zhao, YuChi

    2013-07-08

    This is a retrospective study comparing polyethylene wear between ceramic ball heads and metal ball heads in total hip arthroplasty. The ceramic-on-polyethylene bearing option has been introduced as an alternative to metal-on-polyethylene to minimize polyethylene wear debris and reduce subsequent osteolysis and aseptic loosening. However, the reported data were debatable. We designed this retrospective study to compare polyethylene wear between alumina ceramic ball heads and cobalt-chrome ball heads. Bilateral simultaneous primary total hip arthroplasty was performed in 22 patients between January 2002 and December 2002, with one side using metal-on-polyethylene bearing surface and the other side using alumina ceramic-on-polyethylene bearing surface. After 10 years of follow-up, the wear rate of polyethylene liner on both sides was measured using the Dorr method and compared. The annual wear rate of the polyethylene liner was 0.133 mm with a standard deviation of 0.045 in the metal-on-polyethylene group and 0.056 mm with a standard deviation of 0.032 in the ceramic-on-polyethylene group. The wear rate per year was significantly lower in the ceramic-on-polyethylene group (p chrome. By increasing polyethylene liner survivorship and decreasing potential osteolytic response and aseptic loosening, ceramic head is a better alternative than cobalt-chrome head.

  17. Immediate Placement of Ultrawide-Diameter Implants in Molar Sockets: Description of a Recommended Technique.

    Science.gov (United States)

    Hattingh, André C; De Bruyn, Hugo; Ackermann, Andrew; Vandeweghe, Stefan

    Immediate implant placement is performed less frequently in molar extraction sockets than in single root sockets. This is mainly due to the tripodal anatomical configuration of molar roots, which is perceived as complex and therefore unsuitable. The mechanical burden of molar sites, combined with much larger socket dimensions, make it amenable to the use of ultrawide-diameter dental implants. This article describes a practical, sequenced technique that can be used predictably for immediate implant placement in maxillary and mandibular first molar sockets, using a dry skull model for clarification. This detailed description is based on the experience of more than 580 clinical cases over a 10-year period.

  18. Control design and robustness analysis of a ball and plate system by using polynomial chaos

    Science.gov (United States)

    Colón, Diego; Balthazar, José M.; dos Reis, Célia A.; Bueno, Átila M.; Diniz, Ivando S.; de S. R. F. Rosa, Suelia

    2014-12-01

    In this paper, we present a mathematical model of a ball and plate system, a control law and analyze its robustness properties by using the polynomial chaos method. The ball rolls without slipping. There is an auxiliary robot vision system that determines the bodies' positions and velocities, and is used for control purposes. The actuators are to orthogonal DC motors, that changes the plate's angles with the ground. The model is a extension of the ball and beam system and is highly nonlinear. The system is decoupled in two independent equations for coordinates x and y. Finally, the resulting nonlinear closed loop systems are analyzed by the polynomial chaos methodology, which considers that some system parameters are random variables, and generates statistical data that can be used in the robustness analysis.

  19. Control design and robustness analysis of a ball and plate system by using polynomial chaos

    Energy Technology Data Exchange (ETDEWEB)

    Colón, Diego [University of São Paulo, Polytechnic School, LAC -PTC, São Paulo (Brazil); Balthazar, José M. [São Paulo State University - Rio Claro Campus, Rio Claro (Brazil); Reis, Célia A. dos [São Paulo State University - Bauru Campus, Bauru (Brazil); Bueno, Átila M.; Diniz, Ivando S. [São Paulo State University - Sorocaba Campus, Sorocaba (Brazil); Rosa, Suelia de S. R. F. [University of Brasilia, Brasilia (Brazil)

    2014-12-10

    In this paper, we present a mathematical model of a ball and plate system, a control law and analyze its robustness properties by using the polynomial chaos method. The ball rolls without slipping. There is an auxiliary robot vision system that determines the bodies' positions and velocities, and is used for control purposes. The actuators are to orthogonal DC motors, that changes the plate's angles with the ground. The model is a extension of the ball and beam system and is highly nonlinear. The system is decoupled in two independent equations for coordinates x and y. Finally, the resulting nonlinear closed loop systems are analyzed by the polynomial chaos methodology, which considers that some system parameters are random variables, and generates statistical data that can be used in the robustness analysis.

  20. Design and Implementation of Classical Sliding Mode Controller for Ball and Plate System

    Directory of Open Access Journals (Sweden)

    Laith Jasim Saud

    2017-06-01

    Full Text Available Ball and Plate (B&P system is a benchmark system in the control engineering field that has been used to verify many control methods. In this paper the design of a sliding mode . controller has been investigated and verified in real-time via implementation on a real ball and plate system hardware. The mathematical model has been derived and the necessary parameters have been measured. The sliding mode controller has been designed based on the obtained mathematical model. The resulting controller has been implemented using the Arduino Mega 2560 and a ball and plate system built completely from scratch. The Arduino has been programmed by the Arduino support target for Simulink. Three test signals has been used for verification purposes, namely: single point stabilizing, circular trajectory tracking, and square trajectory tracking. The results obtained have shown that sliding mode controller is able to follow the desired test signals with low error.

  1. Effect of Nd:YAG laser light on post-extractive socket healing in rats treated with zoledronic acid and dexamethasone

    Science.gov (United States)

    Mergoni, Giovanni; Merigo, Elisabetta; Passerini, Pietro; Corradi, Domenico; Maestri, Roberta; Bussolati, Ovidio; Bianchi, Massimiliano; Sala, Roberto; Govoni, Paolo; Namour, Samir; Vescovi, Paolo

    2016-03-01

    Introduction The effect of low level laser therapy (LLLT) on the healing process could be useful for the prevention of post-extractive Bisphosphonate-related Osteonecrosis of the Jaws (BRONJ). The aim of the study was to investigate the effect of LLLT on the post-extractive socket healing in rats treated with zoledronic acid and dexamethasone. Material and Methods Thirty male Sprague-Dawley rats were divided in 4 groups: control group (C, n = 5), laser group (L, n = 5), treatment group (T, n = 10) and treatment plus laser group (T+L, n = 10). Rats of group T and T+L received zoledronate 0,1 mg/Kg and dexamethasone 1 mg/Kg every 2 days for 10 weeks. Rats of group C and L were infused with vehicle. After 9 weeks the first maxillary molars were extracted in all rats. Rats of groups L and T+L received laser therapy (Nd:YAG, 1064 nm, 1.25W, 15Hz, 5 min, 14.37 J/cm2) in the socket area at days 0, 2, 4 and 6 after surgery. At 8 days from extraction, the sockets were clinically assessed with a grading score and the wound area was measured with a dedicate software. Histomorphometric evaluation and western blot analysis of osteopontin and osteocalcin expression were performed. Results Group T+L showed a trend toward a better clinical grading score compared to group T (grade I 22% Vs 28 % - grade II 56% Vs 28% - grade III 22% Vs 44%, respectively). The average wound area was similar among the groups. Inhibition of osteoclastic alveolar bone resorption was found in groups T and T+L (Phealing in conditions at risk for MRONJ development.

  2. Biomechanical Analysis of a Filiform Mechanosensory Hair Socket of Crickets.

    Science.gov (United States)

    Joshi, Kanishka; Mian, Ahsan; Miller, John

    2016-08-01

    Filiform mechanosensory hairs of crickets are of great interest to engineers because of the hairs' highly sensitive response to low-velocity air-currents. In this study, we analyze the biomechanical properties of filiform hairs of the cercal sensory system of a common house cricket. The cercal sensory system consists of two antennalike appendages called cerci that are situated at the rear of the cricket's abdomen. Each cercus is covered with 500-750 flow sensitive filiform mechanosensory hairs. Each hair is embedded in a complex viscoelastic socket that acts as a spring and dashpot system and guides the movement of the hair. When a hair deflects due to the drag force induced on its length by a moving air-current, the spiking activity of the neuron that innervates the hair changes and the combined spiking activity of all hairs is extracted by the cercal sensory system. Filiform hairs have been experimentally studied by researchers, though the basis for the hairs' biomechanical characteristics is not fully understood. The socket structure has not been analyzed experimentally or theoretically from a mechanical standpoint, and the characterization that exists is mathematical in nature and only provides a very rudimentary approximation of the socket's spring nature. This study aims to understand and physically characterize the socket's behavior and interaction with the filiform hair by examining hypotheses about the hair and socket biomechanics. A three-dimensional computer-aided design (CAD) model was first created using confocal microscopy images of the hair and socket structure of the cricket, and then finite-element analyses (FEAs) based on the physical conditions that the insect experiences were simulated. The results show that the socket can act like a spring; however, it has two-tier rotational spring constants during pre- and postcontacts of iris and hair bulge due to its constitutive nonstandard geometric shapes.

  3. A 5- Year Comparison of Marginal Bone Level Following Immediate Loading of Single-Tooth Implants Placed in Healed Alveolar Ridges and Extraction Sockets in the Maxilla.

    Directory of Open Access Journals (Sweden)

    Antoine Nicolas Berberi

    2014-01-01

    Full Text Available AbstractPurpose: The aim of present investigation was to evaluate marginal bone level after 5-year follow-up of implants placed in healed ridges and fresh extraction sockets in maxilla with immediate loading protocol.Materials and Methods: Thirty-six patients in need of a single tooth replacement in the anterior maxilla received 42 Astra Tech implants (Astra Tech Implant system™, Dentsply Implants, Mölndal, Sweden. Implants were placed in healed ridges (group I or immediately into extraction sockets (group II. Implants were restored and placed into functional loading immediately by using a prefabricated abutment. Marginal bone level relative to the implant reference point was recorded at implant placement, crown cementation, 12, 36 and 60 months following loading using intra-oral radiographs. Measurements were made on the mesial and distal sides of each implantResults: Overall, two implants were lost from the group II, before final crown cementation: they were excluded from the study and all remaining implants osseointegrated successfully after 5 years of functional loading. The mean change in marginal bone loss after implant placement was 0.267±0.161 for one year, and 0.265±0.171 for three years and 0.213±0.185 for five years in extraction sockets and was 0.266±0.176 for one year and 0.219±0.175 for three years and 0.194±0.172 for five years in healed ridges group. Significant reduction of marginal bone loss was more pronounced in implants inserted in healed ridges (P

  4. The Effect of Stress and TiC Coated Balls on Lubricant Lifetimes Using a Vacuum Ball-on-Plate Rolling Contact Tribometer

    Science.gov (United States)

    Jones, William R., Jr.; Jansen, Mark J.; Helmick, Larry H.; Nguyen, QuynhGiao; Wheeler, Donald R.; Boving, Hans J.

    1999-01-01

    A vacuum ball-on-plate rolling contact tribometer was used to determine the relative lifetimes of a perfluoropolyether (Krytox 143 AC) on 440C stainless steel. The effect of mean Hertzian stresses (0.75, 1.0, 1.5, and 2.0 GPa) and the use of TiC-coated balls on lubricant lifetime was studied. Other conditions included: 100 rpm, 50 micro-g of lubricant, an initial vacuum level of less than 1.0 x 10(exp -8) Torr, and room temperature (23 C). Increasing the mean Hertzian stress from 0.75 to 2.0 GPa results in an exponential decrease in lubricant lifetime for both material combinations. However, substituting a TiC ball for the 440C ball quadrupled lifetime at low stress levels (0.75 and 1.0 GPa) and doubled life at higher stresses (1.5 and 2.0 GPa). The reduced reactivity of the TiC surface with the PFPE lubricant is considered to be the reason for this enhancement. Decreasing lifetime with increasing stress levels correlated well with energy dissipation calculations.

  5. Galvanic Interaction between Chalcopyrite and Pyrite with Low Alloy and High Carbon Chromium Steel Ball

    Directory of Open Access Journals (Sweden)

    Asghar Azizi

    2013-01-01

    Full Text Available This study was aimed to investigate the galvanic interaction between pyrite and chalcopyrite with two types of grinding media (low alloy and high carbon chromium steel ball in grinding of a porphyry copper sulphide ore. Results indicated that injection of different gases into mill altered the oxidation-reduction environment during grinding. High carbon chromium steel ball under nitrogen gas has the lowest galvanic current, and low alloy steel ball under oxygen gas had the highest galvanic current. Also, results showed that the media is anodic relative to pyrite and chalcopyrite, and therefore pyrite or chalcopyrite with a higher rest potential acted as the cathode, whilst the grinding media with a lower rest potential acted as the anode, when they are electrochemically contacted. It was also found that low alloy steel under oxygen produced the highest amount of EDTA extractable iron in the slurry, whilst high carbon chromium steel under nitrogen atmosphere led to the lowest amount.

  6. A retrospective evaluation of 128 socket-shield cases in the esthetic zone and posterior sites: Partial extraction therapy with up to 4 years follow-up.

    Science.gov (United States)

    Gluckman, Howard; Salama, Maurice; Du Toit, Jonathan

    2017-11-26

    Tooth loss results in an inevitable alveolar ridge reduction. This has established a cautionary approach to extract, wait, augment, and insert the implant, in lieu of immediate placement. However, saving the tooth or part of it whenever possible is more conservative and supports the vital periodontal tissue buccofacial to an implant. The purpose of this cases series was to report on implant survival using this technique in a large cohort of patients at mid-term follow-up. A private practice patient database was searched for all patients having received socket-shield treatment in conjunction with immediate implant placement. Of the results returned, 128 met the inclusion criteria of ≥12 months from date of restoration, or failing prior to definitive restoration. These patients were recalled for evaluation of the restored implants up to 4 years post-treatment. Seventy immediate implants with socket-shields were placed in female patients and 58 in males, age range 24-71 (mean 39 years). The distribution of sites treated were: maxillary incisors (64%), premolars (22%), canines (14%); maxilla (89.9%), mandible (10.1%). 123/128 implants osseointegrated and survived 1-4 years following restoration (survival rate 96.1%). A combined complication rate of 25/128 implants occurred (19.5%). Five implants failed to osseointegrate and were removed. The remaining 20 complications were all managed or observed without management, with implants surviving at mid-term follow-up. Notwithstanding technique sensitivity and the need for randomized control studies, this case series demonstrates that the socket-shield performs competitively when compared to implant survival rates in both conventional immediate and delayed implant placement. © 2017 Wiley Periodicals, Inc.

  7. The effect of the heights and thicknesses of the remaining root segments on buccal bone resorption in the socket-shield technique: An experimental study in dogs.

    Science.gov (United States)

    Tan, Zhen; Kang, Jian; Liu, Wenjia; Wang, Hang

    2018-02-08

    To date only a few studies have been done on the use of the socket-shield technique for preserving the resorption of the buccal bone in aesthetically sensitive sites. Besides, there have been no further studies on the effect of the heights and thicknesses of the remaining root segments on buccal bone resorption when using this method. The aim of this study was to evaluate the effect of different heights and thicknesses of the remaining root segments on bone resorption in the socket-shield technique. Four healthy female beagle dogs were used in this study. The third premolar (P3) and the fourth premolar (P4) on both sides of the mandible were hemisected in the buccal-lingual direction, and the clinical crown of the distal root was beheaded. In the experimental groups, the roots were worn down in the apical direction until they were located at the buccal crestal level (Group A) or 1 mm higher than that level (Group B). In the control group, the distal root segments were extracted. Then, implant placement was performed into the distal root. After 3 months of healing, the specimens were prepared for histological diagnosis. There was no difference between Group A and Group B when using the socket-shield technique, but the results of both groups were better than those of the control group. The height of the root segments has little effect on the bone absorption of alveolar bone, while the bone absorption was strongly influenced by the thickness of the root segments. More precisely, the absorption may decrease if the thickness of the root fragment increases, when the thickness of the root plate is in the 0.5-1.5 mm range. © 2018 Wiley Periodicals, Inc.

  8. Effect of Kinesiotape Applications on Ball Velocity and Accuracy in Amateur Soccer and Handball

    Science.gov (United States)

    Müller, Carsten; Brandes, Mirko

    2015-01-01

    Evidence supporting performance enhancing effects of kinesiotape in sports is missing. The aims of this study were to evaluate effects of kinesiotape applications with regard to shooting and throwing performance in 26 amateur soccer and 32 handball players, and to further investigate if these effects were influenced by the players’ level of performance. Ball speed as the primary outcome and accuracy of soccer kicks and handball throws were analyzed with and without kinesiotape by means of radar units and video recordings. The application of kinesiotapes significantly increased ball speed in soccer by 1.4 km/h (p=0.047) and accuracy with a lesser distance from the target by −6.9 cm (p=0.039). Ball velocity in handball throws also significantly increased by 1.2 km/h (p=0.013), while accuracy was deteriorated with a greater distance from the target by 3.4 cm (p=0.005). Larger effects with respect to ball speed were found in players with a lower performance level in kicking (1.7 km/h, p=0.028) and throwing (1.8 km/h, p=0.001) compared with higher level soccer and handball players (1.2 km/h, p=0.346 and 0.5 km/h, p=0.511, respectively). In conclusion, the applications of kinesiotape used in this study might have beneficial effects on performance in amateur soccer, but the gain in ball speed in handball is counteracted by a significant deterioration of accuracy. Subgroup analyses indicate that kinesiotape may yield larger effects on ball velocity in athletes with lower kicking and throwing skills. PMID:26839612

  9. Field and Model Study to Define Baseline Conditions of Beached Oil Tar Balls along Florida’s First Coast

    OpenAIRE

    Peter Bacopoulos; James David Lambert; Mary Hertz; Luis Montoya; Terry Smith

    2014-01-01

    Anecdotal data are currently the best data available to describe baseline conditions of beached oil tar balls on Florida’s First Coast beaches. This study combines field methods and numerical modeling to define a data-driven knowledge base of oil tar ball baseline conditions. Outcomes from the field study include an established methodology for field data collection and laboratory testing of beached oil tar balls, spatial maps of collected samples and analysis of the data as to transport/wash-...

  10. Muscle Activation Among Supine, Prone, and Side Position Exercises With and Without a Swiss Ball.

    Science.gov (United States)

    Escamilla, Rafael F; Lewis, Clare; Pecson, Amanda; Imamura, Rodney; Andrews, James R

    2016-07-01

    Prone, supine, and side position exercises are employed to enhance core stability. Overall core muscle activity would be greater in prone position exercises compared with supine and side position exercises. Controlled laboratory study. Eighteen men and women between 23 and 45 years of age served as subjects. Surface electrodes were positioned over the upper and lower rectus abdominis, external and internal obliques, rectus femoris, latissimus dorsi, and lumbar paraspinals. Electromyography data were collected during 5 repetitions of 10 exercises, then normalized by maximum voluntary isometric contractions (MVIC). Differences in muscle activity were assessed using 1-way repeated-measures analysis of variance, while t tests with a Bonferroni correction were employed to assess pairwise comparisons. Upper and lower rectus abdominis activity was generally significantly greater in the crunch, bent-knee sit-up, and prone position exercises compared with side position exercises. External oblique activity was significantly greater in the prone on ball with right hip extension, side crunch on ball, and side bridge (plank) on toes compared with the prone and side bridge (plank) on knees, the crunch, or the bent-knee sit-up positions. Internal oblique activity was significantly greater in the prone bridge (plank) on ball and prone on ball with left and right hip extension compared with the side crunch on ball and prone and side bridge (plank) on knees positions. Lumbar paraspinal activity was significantly greater in the 3 side position exercises compared with all remaining exercises. Latissimus dorsi activity was significantly greater in the prone on ball with left and right hip extension and prone bridge (plank) on ball and on toes compared with the crunch, bent-knee sit-up, and prone and side bridge (plank) on knees positions. Rectus femoris activity was significantly greater in the prone on ball with left hip extension, bent-knee sit-up, or prone bridge (plank) on toes

  11. There Is No Structural Relationship between Nasal Septal Deviation, Concha Bullosa, and Paranasal Sinus Fungus Balls

    Directory of Open Access Journals (Sweden)

    Tung-Lung Tsai

    2012-01-01

    Full Text Available This study aims to determine the relationship between nasal septal deviation, concha bullosa, and chronic rhinosinusitis by using a definitive pathological and simplified model. Fifty-two consecutive sinus computed tomography scans were performed on patients who received endoscopic sinus surgery and whose final diagnosis was paranasal sinus fungus balls. The incidences of nasal septal deviation and concha bullosa for patients diagnosed with paranasal sinus fungus balls among the study group were 42.3% and 25%, respectively. About 63.6% sinuses with fungus balls were located on the ipsilateral side of the nasal septal deviation, and 46.2% were located on the ipsilateral side of the concha bullosa. When examined by Pearson’s chi-square test and the chi-squared goodness-of-fit test, no significant statistical difference for the presence of paranasal sinus fungus balls between ipsilateral and contralateral sides of nasal septal deviation and concha bullosa was noted (P=0.292 and P=0.593, resp.. In conclusion, we could not demonstrate any statistically significant correlation between the location of infected paranasal sinus, the direction of nasal septal deviation, and the location of concha bullosa, in location-limited rhinosinusitis lesions such as paranasal sinus fungal balls. We conclude that the anatomical variants discussed herein do not predispose patients to rhinosinusitis.

  12. Effects of the Horse Riding Simulator and Ball Exercises on Balance of the Elderly

    Science.gov (United States)

    Kim, SeongGil; Yuk, Goon-chang; Gak, Hwangbo

    2013-01-01

    [Purpose] The aim of this study was to examine the effects of horse riding exercise using a horse riding simulator (HRS) and a ball on static and dynamic balance of elderly people. [Methods] Thirty-two elderly people hospitalized in geriatric hospitals were randomly assigned to the HRS exercise group or the ball exercise groups, and they performed exercise for eight weeks. [Results] The length of postural sway during quite standing with and without eyes closed significantly decreased in both groups after the exercises and there was no significant difference between both groups in the Romberg test. In the functional reach test (FRT), there were significant increases in distance in both groups after the exercises, and the distance of the HRS exercise group was significantly greater than that of the ball exercise group. In the Timed Up & Go test (TUG) and Timed 10-meter walk test (10MWT), the time significantly decreased in both groups, and there was a more significant decrease in the HRS exercise group than in the ball exercise group. [Conclusion] The results of this study indicate that HRS and ball exercises may improve the balance and gait ability of elderly people hospitalized in nursing homes or geriatric hospitals. PMID:24396203

  13. Axino dark matter and baryon number asymmetry production by the Q-ball decay in gauge mediation

    Energy Technology Data Exchange (ETDEWEB)

    Kasuya, Shinta [Department of Mathematics and Physics, Kanagawa University, Kanagawa 259-1293 (Japan); Kawakami, Etsuko; Kawasaki, Masahiro, E-mail: kasuya@kanagawa-u.ac.jp, E-mail: kwkm@icrr.u-tokyo.ac.jp, E-mail: kawasaki@icrr.u-tokyo.ac.jp [Institute for Cosmic Ray Research, University of Tokyo, Chiba 277-8582 (Japan)

    2016-03-01

    We investigate the Q-ball decay into the axino dark matter in the gauge-mediated supersymmetry breaking. In our scenario, the Q ball decays mainly into nucleons and partially into axinos to account respectively for the baryon asymmetry and the dark matter of the universe. The Q ball decays well before the big bang nucleosynthesis so that it is not affected by the decay. We show the region of the parameters which realizes this scenario.

  14. Effects of residual stress on fatigue strength of small diameter welded pipe joint

    International Nuclear Information System (INIS)

    Yamashita, Tetsuo; Hattori, Takahiro; Nomoto, Toshiharu; Iida, Kunihiro; Sato, Masanobu

    1996-01-01

    A power plant consists of many welded components, therefore, it is essential in establishing the reliability of the power plant to maintain the reliability of all welded components. The fatigue failure caused by mechanical vibrations of small diameter welded joints, which is represented by socket welded joints, is one of the major causes of trouble for the welded parts of the power plant. Here, bending fatigue tests were conducted to investigate the fatigue strength of small diameter socket welded pipe joints. In the most cases of large diameter socket joints, a fatigue crack started from the root of the fillet weld though the stress amplitude at the root was smaller than that at the toe of fillet weld. Additionally, the fatigue strength was affected by the weld bead sequence. The residual stress was considered to be one of the important parameters governing fatigue strength, therefore, its effects were investigated. In several types of pipe joints, the local stress and residual stress distributions were calculated by finite element analysis. The residual stresses were compressive at the toe and tensile at the root of the socket welded joints. Based on these results, the effects of residual stresses on the fatigue strength are discussed for small diameter welded pipe joints in the present work

  15. Evaluation of safety balls and faceguards for prevention of injuries in youth baseball.

    Science.gov (United States)

    Marshall, Stephen W; Mueller, Frederick O; Kirby, Daniel P; Yang, Jingzhen

    2003-02-05

    Safety balls and faceguards are widely used in youth baseball, but their effectiveness in reducing injury is unknown. To evaluate the association of the use of faceguards and safety balls and injuries in youth baseball. Ecological study using a national database of compensated insurance claims maintained by Little League Baseball Incorporated, combined with data on the number of participants in Little League and data from a census of protective equipment usage for youth aged 5 to 18 years participating in Little League Baseball in the United States during 1997-1999. Rate of injury and injury rate ratio comparing users with nonusers of protective equipment. A total of 6 744 240 player-seasons of follow-up and 4233 compensated injury claims were available for analysis. The absolute incidence of compensated injury per 100 000 player-seasons was 28.02 (95% confidence interval [CI], 26.76-29.29) for ball-related injury and 2.71 (95% CI, 2.32-3.11) for facial injury. Overall, use of safety balls was associated with a reduced risk of ball-related injury (adjusted rate ratio, 0.77; 95% CI, 0.64-0.93). This reduction was essentially due to 1 type of safety ball, known as the reduced-impact ball (adjusted rate ratio, 0.72; 95% CI, 0.57-0.91). Use of faceguards reduced the risk of facial injury (adjusted rate ratio, 0.65; 95% CI, 0.43-0.98). Metal and plastic guards appeared to be equally effective. Safety balls appeared to be more effective in the minor division (ages 7-12 years) than in the regular division (ages 9-12 years). Reduced-impact balls and faceguards were associated with a reduced risk of injury in youth baseball. These findings support increased usage of these items; however, it should be noted that the absolute incidence of injury in youth baseball is low and that these equipment items do not prevent all injuries.

  16. Comparison of characteristics of hydroxyapatite powders synthesized from cuttlefish bone via precipitation and ball milling techniques

    Science.gov (United States)

    Faksawat, K.; Kaewwiset, W.; Limsuwan, P.; Naemchanthara, K.

    2017-09-01

    The aim of this work was to compare characteristics of hydroxyapatite synthesized by precipitation and ball milling techniques. The cuttlefish bone powder was a precursor in calcium source and the di ammonium hydrogen orthophosphate powders was a precursor in phosphate source. The hydroxyapatite was synthesized by the both techniques such as precipitation and ball milling techniques. The phase formation, chemical structure and morphology of the both hydroxyapatite powders have been examined by X-ray diffractometer (XRD), Fourier transform infrared spectroscope (FTIR) and field emission scanning electron microscope (FESEM), respectively. The results show that the hydroxyapatite synthesized by precipitation technique formed hydroxyapatite phase slower than the hydroxyapatite synthesized by ball milling technique. The FTIR results show the chemical structures of sample in both techniques are similar. The morphology of the hydroxyapatite from the both techniques were sphere like shapes and particle size was about in nano scale. The average particle size of the hydroxyapatite by ball milling technique was less than those synthesized by precipitation technique. This experiment indicated that the ball milling technique take time less than the precipitation technique in hydroxyapatite synthesis.

  17. A comparative evaluation of extraction socket preservation with demineralized freeze-dried bone allograft alone and along with platelet-rich fibrin: A clinical and radiographic study

    Directory of Open Access Journals (Sweden)

    Dhaval J Thakkar

    2016-01-01

    Full Text Available Aims: To investigate clinically and radiographically, the bone fill in extraction sockets using demineralized freeze-dried bone allograft alone and along with platelet-rich fibrin (PRF. Materials and Methods: A randomized controlled clinical trial was carried out on 36 nonrestorable single-rooted teeth sites. Sites were randomized into demineralized freeze-dried bone allograft (DFDBA combined with PRF - test and DFDBA - control groups using a coin toss method. After the placement of graft material, collagen membrane was used to cover it. The clinical parameters recorded were ridge width and ridge height. All the parameters were recorded at baseline and at 90 and 180 days. Statistical Analysis Used: Independent t-test and paired t-test. Results: In both groups, there is significant reduction in loss of ridge width and ridge height from baseline to 90 days (P < 0.001, baseline to 180 days (P < 0.001, and 90-180 days (P < 0.001. However, when both the groups were compared the test group favored in the reduction of ridge width while there was no statistical difference in reduction of ridge height among at different intervals. Conclusions: Although DFDBA is considered as an ideal graft material, PRF can be used as an adjunctive with DFDBA for socket preservation.

  18. Acoustic measurements of bouncing balls and the determination of gravitational acceleration

    Science.gov (United States)

    Schwarz, Oliver; Vogt, Patrik; Kuhn, Jochen

    2013-05-01

    Interesting experiments can be performed and fundamental physical relationships can be explored with so-called Super Balls or bouncy balls. An example is the determination of gravity g in an experiment. The basic idea behind this was described by Pape and Sprockhoff2: The initial and final heights and the complete duration of all the bounces are measured for a certain number of bounces by the ball. On the basis of this data, the acceleration of gravity can be approximately calculated if air drag on the ball is neglected. However, in practice, it becomes clear that measuring the height of the last bounce in the process is problematic. The person performing the experiment either has to make a good estimation of its height or film the bounce in front of a measuring stick. The method is based on the important assumption that each of the individual bounces of the ball loses the same percentage of mechanical energy; the coefficient of restitution k therefore remains the same.

  19. Formation Mechanism and Characteristics Research of Ball Lightning Based on Vortex Model

    Science.gov (United States)

    Li, Zi-Cheng; Yang, Guo-Hua

    2011-05-01

    The strange characteristics of ball lightning are considered as a question hard to explain. In order to solve the problem, in this paper a complete model of plasma vortex is presented for the ball lightning. By ideal MHD equations, through imposing disturbance to plasma column, the possibility of sausage and kink instability of the lightning channel is analyzed from the perspective the minimum potential energy. The conclusion is that the kink instability (m = 1) is most prone to occur. And when instability occurs, because of the difference of the magnetic field in the twisted area, the magnetic pressure makes the trend further and therefore forming the plasma vortex that may eventually turn into ball lightning if the energy of the vortex is large enough. The existence of the vortex makes ball lightning have a short period of time stability. By the proposed model, the ball lightning features that are hard to understand in the past are explained. In this paper, the reason for bead lightning is also explained from the perspective of the sausage instability.

  20. Simultaneous measurement of gas concentration and temperature by the ball surface acoustic wave sensor

    Science.gov (United States)

    Yamanaka, Kazushi; Akao, Shingo; Takeda, Nobuo; Tsuji, Toshihiro; Oizumi, Toru; Tsukahara, Yusuke

    2017-07-01

    We have developed a ball surface acoustic wave (SAW) trace moisture sensor with an amorphous silica sensitive film and realized wide-range measurement from 0.017 ppmv [a frost point (FP) of -99 °C] to 6.0 × 103 ppmv (0 °C FP). However, since the sensitivity of the sensor depends on the temperature, measurement results are disturbed when the temperature largely changes. To overcome this problem, we developed a method to simultaneously measure temperature and gas concentration using a ball SAW sensor. Temperature and concentration is derived by solving equations for the delay time change at two frequencies. When the temperature had a large jump, the delay time change was significantly disturbed, but the water concentration was almost correctly measured, by compensating the sensitivity change using measured temperature. The temperature measured by a ball SAW sensor will also be used to control the ball temperature. This method will make a ball SAW sensor reliable in environments of varying temperatures.

  1. Study of the dynamic properties and effects of temperature using a spring model for the bouncing ball

    Science.gov (United States)

    Wadhwa, Ajay

    2013-05-01

    We studied the motion of a bouncing ball by representing it through an equivalent mass-spring system executing damped harmonic oscillations. We represented the elasticity of the system through the spring constant ‘k’ and the viscous damping effect, causing loss of energy, through damping constant ‘c’. By including these two factors we formed a differential equation for the equivalent mass-spring system of the bouncing ball. This equation was then solved to study the elastic and dynamic properties of its motion by expressing them in terms of experimentally measurable physical quantities such as contact time, coefficient of restitution, etc. We used our analysis for different types of ball material: rubber (lawn-tennis ball, super ball, soccer ball and squash ball) and plastic (table-tennis ball) at room temperature. Since the effect of temperature on the bounce of a squash ball is significant, we studied the temperature dependence of its elastic properties. The experiments were performed using audio and surface-temperature sensors interfaced with a computer through a USB port. The work presented here is suitable for undergraduate laboratories. It particularly emphasizes the use of computer interfacing for conducting conventional physics experiments.

  2. 76 FR 57019 - Ball Bearings and Parts Thereof From France, Germany and Italy: Final Results of Sunset Reviews...

    Science.gov (United States)

    2011-09-15

    ... Bearings and Parts Thereof From France, Germany and Italy: Final Results of Sunset Reviews and Revocation... sunset reviews of the antidumping duty orders on ball bearings and parts thereof from France, Germany... antidumping duty orders on ball bearings and parts thereof from France, Germany, and Italy. DATES: Effective...

  3. 77 FR 2511 - Ball Bearings and Parts Thereof From France, Germany, and Italy: Extension of Time Limit for...

    Science.gov (United States)

    2012-01-18

    ... Bearings and Parts Thereof From France, Germany, and Italy: Extension of Time Limit for Preliminary Results... ball bearings and parts thereof from France, Germany, Italy, Japan, and the United Kingdom for the... the antidumping duty orders with respect to ball bearings and parts thereof from Japan and the United...

  4. 77 FR 16537 - Ball Bearings and Parts Thereof from France, Germany, and Italy: Extension of Time Limit for...

    Science.gov (United States)

    2012-03-21

    ... Bearings and Parts Thereof from France, Germany, and Italy: Extension of Time Limit for Preliminary Results... ball bearings and parts thereof from France, Germany, Italy, Japan, and the United Kingdom for the... Revocation in Part, 76 FR 37781 (June 28, 2011). See also Ball Bearings and Parts Thereof From Japan and the...

  5. Cosmetic effect of knee joint in a knee disarticulation prosthesis

    NARCIS (Netherlands)

    de laat, Fred A.; van der Pluijm, Mark J.; van Kuijk, Annette A.; Geertzen, Jan H.; Roorda, Leo D.

    2014-01-01

    Despite numerous advantages, knee disarticulations (KDs) are rarely performed because of the anticipated KD prosthesis fitting problems that include the positioning of the knee joint distally from the KD socket. This results in lengthening of the thigh and subsequent shortening of the shank. The

  6. A study on a new algorithm to optimize ball mill system based on modeling and GA

    International Nuclear Information System (INIS)

    Wang Heng; Jia Minping; Huang Peng; Chen Zuoliang

    2010-01-01

    Aiming at the disadvantage of conventional optimization method for ball mill pulverizing system, a novel approach based on RBF neural network and genetic algorithm was proposed in the present paper. Firstly, the experiments and measurement for fill level based on vibration signals of mill shell was introduced. Then, main factors which affected the power consumption of ball mill pulverizing system were analyzed, and the input variables of RBF neural network were determined. RBF neural network was used to map the complex non-linear relationship between the electric consumption and process parameters and the non-linear model of power consumption was built. Finally, the model was optimized by genetic algorithm and the optimal work conditions of ball mill pulverizing system were determined. The results demonstrate that the method is reliable and practical, and can reduce the electric consumption obviously and effectively.

  7. 76 FR 52937 - Ball Bearings and Parts Thereof From France, Germany, and Italy: Final Results of Antidumping...

    Science.gov (United States)

    2011-08-24

    ... Bearings and Parts Thereof From France, Germany, and Italy: Final Results of Antidumping Administrative and... preliminary results of the administrative reviews of the antidumping duty orders on ball bearings and parts... Schaeffler KG with respect to the order on ball bearings and parts thereof from Germany. DATES: Effective...

  8. 77 FR 73415 - Ball Bearings and Parts Thereof From France, Germany, and Italy: Final Results of Antidumping...

    Science.gov (United States)

    2012-12-10

    ... Bearings and Parts Thereof From France, Germany, and Italy: Final Results of Antidumping Duty... preliminary results of the administrative reviews of the antidumping duty orders on ball bearings and parts... ball bearings and parts thereof from France, Germany, and Italy.\\1\\ The period of review is May 1, 2010...

  9. 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.

  10. A vision framework for the localization of soccer players and ball on the pitch using Handycams

    Science.gov (United States)

    Vilas, Tiago; Rodrigues, J. M. F.; Cardoso, P. J. S.; Silva, Bruno

    2015-03-01

    The current performance requirements in soccer make imperative the use of new technologies for game observation and analysis, such that detailed information about the teams' actions is provided. This paper summarizes a framework to collect the soccer players and ball positions using one or more Full HD Handycams, placed no more than 20cm apart in the stands, as well as how this framework connects to the FootData project. The system was based on four main modules: the detection and delimitation of the soccer pitch, the ball and the players detection and assignment to their teams, the tracking of players and ball and finally the computation of their localization (in meters) in the pitch.

  11. Predictive Ability of the Medicine Ball Chest Throw and Vertical Jump Tests for Determining Muscular Strength and Power in Adolescents

    Science.gov (United States)

    Hackett, Daniel A.; Davies, Timothy B.; Ibel, Denis; Cobley, Stephen; Sanders, Ross

    2018-01-01

    This study examined the predictive ability of the medicine ball chest throw and vertical jump for muscular strength and power in adolescents. One hundred and ninety adolescents participated in this study. Participants performed trials of the medicine ball chest throw and vertical jump, with vertical jump peak power calculated via an estimation…

  12. 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.

  13. The Efficacy of Immediate Implant Placement in Extraction Sockets for Alveolar Bone Preservation: A Clinical Evaluation Using Three-Dimensional Cone Beam Computerized Tomography and Resonance Frequency Analysis Value.

    Science.gov (United States)

    Qabbani, Ali Al; Razak, Noor Hayati A; Kawas, Sausan Al; Sheikh Abdul Hamid, Suzina; Wahbi, Saad; Samsudin, A R

    2017-06-01

    The aim of this study was to determine the efficacy of immediate implant placement with alveolar bone augmentation on socket preservation following atraumatic tooth extraction and comparing it with a tooth alveolar socket that was allowed to heal in a conventional way.Twenty medically fit patients (8 males and 12 females aged between 18 and 40 years) who needed noncomplicated tooth extraction of mandibular premolar teeth were divided randomly and equally into 2 groups. In Group I, the empty extraction socket was left untreated and allowed to heal in a conventional way. In Group II, the immediate implant was placed and the gap between the implant and the inner buccal plate surface of the socket wall was filled with lyophilized bovine bone granules and the wound was covered with pericardium membrane. The patients were followed up clinically and radiologically for regular reviews at 1 week, 3 months, and 9 months postoperative. Cone beam computerized tomography images of the alveolar ridge and socket were analyzed to determine the structural changes of the alveolar ridge. Resonance frequency analysis was measured at 9 months for Group II to assess the degree of secondary stability of the implants by using Osstell machine.A significant difference of bone resorption of 1.49 mm (confidence interval, CI 95%, 0.63-2.35) was observed within the control group at 3 months, and 1.84 mm (P ≤ 0.05) at 9 months intervals. No significant changes of bone resorption were observed in Group II. Comparison between groups showed a highly significant difference at 3 months; 2.56 mm (CI 95% 4.22-0.90) and at 9 months intervals; 3.2 mm (CI 95%, 4.70-1.62) P ≤ 0.001 between Group I and II. High resonance frequency analysis values were observed at 9 months postoperative in Group II.In conclusion, the insertion of immediate implants in fresh extraction sockets together with grafting the circumferential gap between the bony socket wall and the implant surface with bovine

  14. THE INFLUENCE OF BALL VELOCITY AND COURT ILLUMINATION ON REACTION TIME FOR TENNIS VOLLEY

    Directory of Open Access Journals (Sweden)

    Jui-hung Tu

    2010-03-01

    Full Text Available The he purpose of this study is to examine the effects of ball velocity, court illumination, and volley type on the reaction time (RT of a tennis athlete for a volley stroke. Eights cases with two different ball velocities (high and low, two volley types (forehand and backhand and two court illumination levels (dark and bright were studied. The 30 participating subjects consisted of 18 male and 12 female college tennis athletes (age: 24 ± 3.2 yr, with a United States Tennis Association (USTA ranking above 2.5. In order to ensure the validity of real-world correlations, the experiments were designed to simulate real competition situations. Reaction times were measured for volley strokes in response to different approaching ball velocities (high: 25.05 ± 0.37 m/s and low: 17.56 ± 0.92 m·s-1 for several volley types (forehand and backhand and court illumination levels (55649 ± 4292 lux and 363.24 ± 6.53 lux on the court. During the tests, the signals from an electromyogram sensor and a 3-axis accelerometer (± 50 g were recorded using an NI DAQ card (NI PXI-6251 and then analyzed to determine reaction time (RT, premotor reaction time (PRT, and motor reaction time (MRT through the LabVIEW system. Subsequent 3-way ANOVA analysis indicated no RT, PRT, or MRT interaction between ball velocity, volley type and illumination. The ball velocity and illumination parameters did affect RT and PRT values significantly with p < 0.05, no significant variation in MRT was observed across any implemented experimental conditions. All experimental results indicate that ball velocity and illumination levels strongly affect the value of PRT, but have no significant effect on the value of MRT, the changes in RT were dominated by PRT

  15. 76 FR 60871 - Ball Bearings and Parts Thereof From France, Germany, and Italy; Termination of Five-Year Reviews

    Science.gov (United States)

    2011-09-30

    ... INTERNATIONAL TRADE COMMISSION [Investigation Nos. 731-TA-391A-393A (Third Review)] Ball Bearings and Parts Thereof From France, Germany, and Italy; Termination of Five-Year Reviews AGENCY: United... initiated in August 2011 to determine whether revocation of the antidumping duty orders on ball bearings and...

  16. 78 FR 76104 - Ball Bearings and Parts Thereof From Japan and the United Kingdom: Notice of Reinstatement of...

    Science.gov (United States)

    2013-12-16

    ... DEPARTMENT OF COMMERCE International Trade Administration [A-588-804, A-412-801] Ball Bearings and... sunset review of the antidumping duty orders on bearings from Japan and the United Kingdom, the... 30, 2011. \\1\\ See Antidumping Duty Orders: Ball Bearings, Cylindrical Roller Bearings, and Spherical...

  17. 76 FR 2647 - Ball Bearings and Parts Thereof From France, Germany, Italy, Japan, and the United Kingdom...

    Science.gov (United States)

    2011-01-14

    ... DEPARTMENT OF COMMERCE International Trade Administration [A-427-801, A-428-801, A-475-801, A-588-804, A-412-801] Ball Bearings and Parts Thereof From France, Germany, Italy, Japan, and the United... administrative reviews of the antidumping duty orders on ball bearings and parts thereof from France, Germany...

  18. Photobiomodulation with LED and laser in repair of mandibular socket rabbit: clinical evaluation, histological, and histomorphometric.

    Science.gov (United States)

    Comunian, Cláudio Rômulo; Custódio, Antônio Luis Neto; de Oliveira, Leandro Junqueira; Dutra, Carlos Eduardo Assis; D'almeida Ferreira Neto, Milton; Rezende, Cleuza Maria Faria

    2017-06-01

    The aim of this study was to evaluate the effects of LED and low-intensity laser on the healing of rabbit dental alveoli. A total of 18 rabbits were divided into three groups of six; all rabbits underwent surgical extraction of the first lower right premolar. Following surgery, group 1 received LED irradiation, group 2 received laser irradiation, and group 3 were untreated controls. The initial applications of LED and laser began 48 h after tooth extraction and were given perpendicularly to the dental alveoli. The three groups were clinically evaluated for 18 days in the postoperative period. At 90 days, the rabbits were euthanized and the mandibular fragments containing the healing alveoli were collected. These fragments initially underwent computed tomography scans and bone density was measured in Hounsfield units. Following this, the fragments were processed and stained with hematoxylin and eosin for histological and histomorphometric analysis. The results were compatible between the clinical, histological, and histomorphometric parameters evaluated. There were no statistical differences between the LED and laser groups. However, the difference of the average bone density between laser and control group was not statistically significant. It was found that photobiomodulation with LASER and LED presented effects. However, only the LED demonstrated a beneficial effect on the process of bone repair in the dental alveoli of rabbits.

  19. OH Radical and a Drizzling Water Jet Production from the Ball-Lightning Discharge in Water

    Science.gov (United States)

    Maeyama, Mitsuaki; Tanaka, Yasutomo

    The ball lightning, or fireball discharge using the typical electrode configuration was reported to produce a long-living spherical plasmoid with radius exceed 10 cm at atmospheric pressure. In this study, we investigated the relationship between a optical output emitted from OH radicals and discharge conditions of the ball-lightning electrode configuration, and discussed its possibility to the water treatment process. As a results, in both polarity cases of the charged voltage V0, a ball-lightning discharge and the optical emission from OH radicals as a major radiation can be generated on the condition |V0| > 4 kV in tap water. Furthermore, an intensive upward water jet from the rod electrode is observed in case of positive polarity and in 0.2% NaCl solution, which is composed of drizzling water drops near the rod electrode.

  20. Design and validation of an improved graphical user interface with the 'Tool ball'.

    Science.gov (United States)

    Lee, Kuo-Wei; Lee, Ying-Chu

    2012-01-01

    The purpose of this research is introduce the design of an improved graphical user interface (GUI) and verifies the operational efficiency of the proposed interface. Until now, clicking the toolbar with the mouse is the usual way to operate software functions. In our research, we designed an improved graphical user interface - a tool ball that is operated by a mouse wheel to perform software functions. Several experiments are conducted to measure the time needed to operate certain software functions with the traditional combination of "mouse click + tool button" and the proposed integration of "mouse wheel + tool ball". The results indicate that the tool ball design can accelerate the speed of operating software functions, decrease the number of icons on the screen, and enlarge the applications of the mouse wheel. Copyright © 2011 Elsevier Ltd and The Ergonomics Society. All rights reserved.

  1. Socket Shield Technique for immediate implant placement - clinical, radiographic and volumetric data after 5 years.

    Science.gov (United States)

    Bäumer, Daniel; Zuhr, Otto; Rebele, Stephan; Hürzeler, Markus

    2017-11-01

    neighboring teeth. Within the limitations of this descriptive study, the socket shield technique offers reduced invasiveness at the time of surgery and high esthetic outcomes with effective preservation of facial tissue contours. This technique should not be used in routine clinical practice until a higher level evidence in the form of prospective clinical trials is available. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  2. Fused Silica Ion Trap Chip with Efficient Optical Collection System for Timekeeping, Sensing, and Emulation

    Science.gov (United States)

    2015-01-22

    are shielded from unwanted perturbations. Such traps permit the observation, manipulation, or storage of isolated particles or small groups of...resins to optimize surface wetting with the glass and surface tension forming a smooth outer surface. The third approach involves fabricating a socket ...B) optical port assemblies consisting of a fiber alignment hole, ball lens socket , and conical shaped aperture(s) opening into the trap slot. The

  3. 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.

  4. First simultaneous measurements of Reynolds stress with ball-pen and Langmuir probes

    Science.gov (United States)

    Grover, Ondrej; Adamek, Jiri; Seidl, Jakub; Devitre, Alexis; Sos, Miroslav; Vondracek, Petr; Bilkova, Petra; Hron, Martin

    2017-06-01

    A new multi-pin probe head was installed and tested at the COMPASS tokamak. The probe head consists of several ball-pen and Langmuir probes in similar geometric configurations, which enables fast, simultaneous measurements of the radial and poloidal electric field components from differences of plasma or floating potentials using appropriately positioned ball-pen or Langmuir probes, respectively. The fast measurements of the radial electric field are compared with other methods of measuring selected frequency components of the radial electric field. The radial profiles of the Reynolds stress calculated from correlations of electric field fluctuations obtained by either probe type are compared along with their spectral composition. Lower Reynolds stress values are found for Langmuir probes in comparison to ball-pen probes due to negative contributions from higher frequency fluctuations possibly associated with electron temperature fluctuations.

  5. First simultaneous measurements of Reynolds stress with ball-pen and Langmuir probes.

    Science.gov (United States)

    Grover, Ondrej; Adamek, Jiri; Seidl, Jakub; Devitre, Alexis; Sos, Miroslav; Vondracek, Petr; Bilkova, Petra; Hron, Martin

    2017-06-01

    A new multi-pin probe head was installed and tested at the COMPASS tokamak. The probe head consists of several ball-pen and Langmuir probes in similar geometric configurations, which enables fast, simultaneous measurements of the radial and poloidal electric field components from differences of plasma or floating potentials using appropriately positioned ball-pen or Langmuir probes, respectively. The fast measurements of the radial electric field are compared with other methods of measuring selected frequency components of the radial electric field. The radial profiles of the Reynolds stress calculated from correlations of electric field fluctuations obtained by either probe type are compared along with their spectral composition. Lower Reynolds stress values are found for Langmuir probes in comparison to ball-pen probes due to negative contributions from higher frequency fluctuations possibly associated with electron temperature fluctuations.

  6. Clinical evaluation of short and wide-diameter implants immediately placed into extraction sockets of posterior areas: a 2-year retrospective study.

    Science.gov (United States)

    Jiansheng, Huang; Dongying, Xuan; Xianfeng, Wang; Baoyi, Xie; Qiong, Liu; Jincai, Zhang

    2012-12-01

    The objective of the study was to determine the short-term success rate of short and wide single-tooth implants, immediately placed into extraction sockets of the posterior area. A retrospective cohort study design was used. A total of 145 subjects received 162 short and wide-diameter single-tooth implants between 2006 and 2009. A minimal 7-mm residual height and 9-mm ridge width was available in all the implant sites, and the attached gingivae were at least 2 mm wide. All implants were placed and restored with the single crown by one experienced operator. The data were analyzed with descriptive statistics. All implants were placed in molar areas. There were 20 Ankylos implants with a diameter 5.5 or 7 mm and a length of 8 mm and 142 hydroxyapatite-coated implants with a diameter 5 or 6 mm and a length of 5.7 to 8 mm. One of the 162 implants failed before prosthetic restoration, resulting in a survival rate of 99.4% after loading. Patients were followed for up to 56 months (mean = 24 months) after loading of implants. The radiographic and clinical data revealed well-maintained hard and soft tissues with acceptable short-term results. For residual ridges with minimal height but adequate width, the immediate placement of short and wide-diameter implants in fresh extraction sockets may offer a simple and predictable treatment alternative if implants are positioned appropriately after a thorough preoperative analysis.

  7. Fiber ball imaging.

    Science.gov (United States)

    Jensen, Jens H; Russell Glenn, G; Helpern, Joseph A

    2016-01-01

    By modeling axons as thin cylinders, it is shown that the inverse Funk transform of the diffusion MRI (dMRI) signal intensity obtained on a spherical shell in q-space gives an estimate for a fiber orientation density function (fODF), where the accuracy improves with increasing b-value provided the signal-to-noise ratio is sufficient. The method is similar to q-ball imaging, except that the Funk transform of q-ball imaging is replaced by its inverse. We call this new approach fiber ball imaging. The fiber ball method is demonstrated for healthy human brain, and fODF estimates are compared to diffusion orientation distribution function (dODF) approximations obtained with q-ball imaging. The fODFs are seen to have sharper features than the dODFs, reflecting an enhancement of the higher degree angular frequencies. The inverse Funk transform of the dMRI signal intensity data provides a simple and direct method of estimating a fODF. In addition, fiber ball imaging leads to an estimate for the ratio of the fraction of MRI visible water confined to the intra-axonal space divided by the square root of the intra-axonal diffusivity. This technique may be useful for white matter fiber tractography, as well as other types of microstructural modeling of brain tissue. Copyright © 2015 Elsevier Inc. All rights reserved.

  8. Searching for axion stars and Q -balls with a terrestrial magnetometer network

    Science.gov (United States)

    Jackson Kimball, D. F.; Budker, D.; Eby, J.; Pospelov, M.; Pustelny, S.; Scholtes, T.; Stadnik, Y. V.; Weis, A.; Wickenbrock, A.

    2018-02-01

    Light (pseudo-)scalar fields are promising candidates to be the dark matter in the Universe. Under certain initial conditions in the early Universe and/or with certain types of self-interactions, they can form compact dark-matter objects such as axion stars or Q -balls. Direct encounters with such objects can be searched for by using a global network of atomic magnetometers. It is shown that for a range of masses and radii not ruled out by existing observations, the terrestrial encounter rate with axion stars or Q -balls can be sufficiently high (at least once per year) for a detection. Furthermore, it is shown that a global network of atomic magnetometers is sufficiently sensitive to pseudoscalar couplings to atomic spins so that a transit through an axion star or Q -ball could be detected over a broad range of unexplored parameter space.

  9. Searching for axion stars and Q-balls with a terrestrial magnetometer network

    Energy Technology Data Exchange (ETDEWEB)

    Jackson Kimball, D. F. [Cal State, East Bay; Budker, D. [UC, Berkeley; Eby, J. [Fermilab; Pospelov, M. [Perimeter Inst. Theor. Phys.; Pustelny, S. [Jagiellonian U.; Scholtes, T. [Fribourg U.; Stadnik, Y. V. [Helmholtz Inst., Mainz; Weis, A. [Fribourg U.; Wickenbrock, A. [Mainz U.

    2017-10-11

    Light (pseudo-)scalar fields are promising candidates to be the dark matter in the Universe. Under certain initial conditions in the early Universe and/or with certain types of self-interactions, they can form compact dark-matter objects such as axion stars or Q-balls. Direct encounters with such objects can be searched for by using a global network of atomic magnetometers. It is shown that for a range of masses and radii not ruled out by existing observations, the terrestrial encounter rate with axion stars or Q-balls can be sufficiently high (at least once per year) for a detection. Furthermore, it is shown that a global network of atomic magnetometers is sufficiently sensitive to pseudoscalar couplings to atomic spins so that a transit through an axion star or Q-ball could be detected over a broad range of unexplored parameter space.

  10. Patient Adviser What to Do About AC Joint Injuries.

    Science.gov (United States)

    Johnson, R J

    2001-11-01

    The muscles, joints, and bones of the shoulders form a base of support that allows your arms to swing, lift, or throw (figure 1). One of these bones, the collarbone, is also called the clavicle. Above your arm is an extension of the shoulder blade called the acromion. Where these two bones meet at the top of the shoulder is the acromioclavicular (AC) joint. The AC joint is not the shoulder joint. The shoulder joint is where the bone of the upper arm (humerus) meets a shallow socket that is also part of the shoulder blade.

  11. Evaluation of the release of dioxins and PCBs during kiln-firing of ball clay.

    Science.gov (United States)

    Broadwater, Kendra; Meeker, John D; Luksemburg, William; Maier, Martha; Garabrant, David; Demond, Avery; Franzblau, Alfred

    2014-01-01

    Ball clay is known to be naturally contaminated with high levels of polychlorinated di-benzo-p-dioxins (PCDDs). This study evaluated the potential for PCDD, polychlorinated dibenzofuran (PCDF) and polychlorinated biphenyl (PCB) release during the kiln firing of ball clay in an art studio. Toxic equivalence (TEQ) were calculated using World Health Organization (WHO) 2005 toxic equivalence factors (TEF) and congener concentrations. Ten bags of commercial ball clay were found to have an average TEQ of 1,370 nanograms/kilogram (ng kg(-1)) dry weight (dw), almost exclusively due to PCDDs (99.98% of TEQ). After firing, none of the 29 dioxin-like analytes was measured above the limits of detection (LOD) in the clay samples. Air samples were taken during firings using both low-flow and high-flow air samplers. Few low-flow air samples contained measurable levels of dioxin congeners above the LOD. The mean TEQ in the high volume air samples ranged from 0.07 pg m(-3) to 0.21 pg m(-3) when firing ball clay, and was 0.11 pg m(-3) when no clay was fired. These concentrations are within the range measured in typical residences and well-controlled industrial settings. The congener profiles in the high-flow air samples differed from the unfired clay; the air samples had a considerable contribution to the TEQ from PCDFs and PCBs. Given that the TEQs of all air samples were very low and the profiles differed from the unfired clay, it is likely that the PCDDs in dry ball clay were destroyed during kiln firing. These results suggest that inhalation of volatilized dioxins during kiln firing of dry ball clay is an unlikely source of exposure for vocational and art ceramicists. Copyright © 2013 Elsevier Ltd. All rights reserved.

  12. The Proton Conductivity of Condensed Phases of Water:. Implications on Linear and Ball Lightning

    Science.gov (United States)

    Tennakone, Kirthi

    2006-06-01

    Ice is a proton conductor, with conductivities ranging from 10-6 to 10-9 S m-1 depending on the purity of the sample. Electronically ice is highly insulating with conductivity of the order 10-12 S m-1 or below. Mobile protons in ice originate from disruption of hydrogen bonds and strong electric fields enhance bond breakage. Ice particle acquires electrification during formation of thunder clouds and ice play a crucial in role charge separation leading to lightning. It is suggested that charges of ice particles in clouds originates from inductive charge separation and transfer of the mobile positive charge to the streaming air. Thus ice particles gain a negative charge and moist air drifting upwards becomes more positive. Consequently, most thunder clouds have a negative charge in the region closer to the ground. Although many explanations are proposed, the elusive phenomenon of ball lightning continues to resist theoretical understanding and laboratory reproduction. Ball lightning originates in the electrical active atmosphere as a luminous sphere drifting in air with the capability of bouncing from walls and penetrating openings smaller than the ball. It is suggested that ball lightning is a negatively charged sphere constituted of an outer shell of ice. Water dipoles are oriented radially by the electric field and protons acquire a high mobility in the tangential direction. As the electron conductivity of the shell in radial direction is very small, the charge slowly leaks to the atmosphere as a corona discharge. Model naturally explains how the ball could penetrate a hole or bounce from a surface as a differential electrostatic stress could develop in the ball as result of the proton conductivity. Details of the models and suggestions for experimental verification of the proposed concepts will be presented.

  13. Accuracy Verification of Magnetic Resonance Imaging (MRI Technology for Lower-Limb Prosthetic Research: Utilising Animal Soft Tissue Specimen and Common Socket Casting Materials

    Directory of Open Access Journals (Sweden)

    Mohammad Reza Safari

    2012-01-01

    Full Text Available Lower limb prosthetic socket shape and volume consistency can be quantified using MRI technology. Additionally, MRI images of the residual limb could be used as an input data for CAD-CAM technology and finite element studies. However, the accuracy of MRI when socket casting materials are used has to be defined. A number of six, 46 mm thick, cross-sections of an animal leg were used. Three specimens were wrapped with Plaster of Paris (POP and the other three with commercially available silicone interface liner. Data was obtained by utilising MRI technology and then the segmented images compared to corresponding calliper measurement, photographic imaging, and water suspension techniques. The MRI measurement results were strongly correlated with actual diameter, surface area, and volume measurements. The results show that the selected scanning parameters and the semiautomatic segmentation method are adequate enough, considering the limit of clinical meaningful shape and volume fluctuation, for residual limb volume and the cross-sectional surface area measurements.

  14. Accuracy verification of magnetic resonance imaging (MRI) technology for lower-limb prosthetic research: utilising animal soft tissue specimen and common socket casting materials.

    Science.gov (United States)

    Safari, Mohammad Reza; Rowe, Philip; Buis, Arjan

    2012-01-01

    Lower limb prosthetic socket shape and volume consistency can be quantified using MRI technology. Additionally, MRI images of the residual limb could be used as an input data for CAD-CAM technology and finite element studies. However, the accuracy of MRI when socket casting materials are used has to be defined. A number of six, 46 mm thick, cross-sections of an animal leg were used. Three specimens were wrapped with Plaster of Paris (POP) and the other three with commercially available silicone interface liner. Data was obtained by utilising MRI technology and then the segmented images compared to corresponding calliper measurement, photographic imaging, and water suspension techniques. The MRI measurement results were strongly correlated with actual diameter, surface area, and volume measurements. The results show that the selected scanning parameters and the semiautomatic segmentation method are adequate enough, considering the limit of clinical meaningful shape and volume fluctuation, for residual limb volume and the cross-sectional surface area measurements.

  15. Optimizing anterior esthetics of a single-tooth implant through socket augmentation and immediate provisionalization: A case report with 7-year follow-up

    Directory of Open Access Journals (Sweden)

    Po-Sung Fu

    2012-10-01

    Full Text Available Tooth extraction inevitably accompanies alveolar ridge resorption with loss of pre-existing tissue morphology. Replacing missing teeth with dental implants has become popular, but restoring anterior teeth with implant-supported restorations is a technique-sensitive task and poses challenges for dentists. With the progress of implant dentistry, the demand for optimal esthetics has become linked with the desire for faster, easier techniques that shorten treatment time and also satisfy patients. Immediate provisionalization of a single-tooth implant provides significant benefits compared with traditional delayed protocols, such as aiding the contouring of peri-implant soft tissue and enhancing patient comfort and satisfaction. This article describes a meticulous approach to a hopeless maxillary central incisor with root fracture. The defect in the extraction socket was reconstructed using autogenous bone harvested from the chin. Four months later, an implant was installed and immediately restored. After another healing period of 6 months, the peri-implant soft tissue had been shaped and matured according to the contours of the provisional restoration. The emergence profile was used to duplicate the definitive restoration. Peri-implant esthetics was achieved through socket augmentation and immediate provisionalization of the implant. This treatment modality attained predictable and maintainable outcomes, both functionally and esthetically.

  16. Effect of birth ball on labor pain relief: A systematic review and meta-analysis.

    Science.gov (United States)

    Makvandi, Somayeh; Latifnejad Roudsari, Robab; Sadeghi, Ramin; Karimi, Leila

    2015-11-01

    To critically evaluate the available evidence related to the impact of using a birth ball on labor pain relief. The Cochrane library, Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE/PubMed and Scopus were searched from their inception to January 2015 using keywords: (Birth* OR Swiss OR Swedish OR balance OR fitness OR gym* OR Pezzi OR sport* OR stability) AND (ball*) AND (labor OR labour OR Obstetric). All available randomized controlled trials involving women using a birth ball for pain relief during labor were considered. The search resulted in 341 titles and abstracts, which were narrowed down to eight potentially relevant articles. Of these, four studies met the inclusion criteria. Pain intensity on a 10 cm visual analogue scale was used as the main outcome measure. Risk of bias was assessed using the Cochrane Risk of Bias tool. Comprehensive Meta-Analysis Version 2 was used for statistical analysis. Four RCTs involving 220 women were included in the systematic review. One study was excluded from the meta-analysis because of heterogeneous interventions and a lack of mean and standard deviation results of labor pain score. The meta-analysis showed that birth ball exercises provided statistically significant improvements to labor pain (pooled mean difference -0.921; 95% confidence interval -1.28, -0.56; P = 0.0000005; I(2)  = 33.7%). The clinical implementation of a birth ball exercise could be an effective tool for parturient women to reduce labor pain. However, rigorous RCTs are needed to evaluate the effect of the birth ball on labor pain relief. © 2015 Japan Society of Obstetrics and Gynecology.

  17. A two-dimensional soliton system of vortex and Q-ball

    Science.gov (United States)

    Loginov, A. Yu.

    2018-02-01

    The (2 + 1)-dimensional gauge model describing two complex scalar fields that interact through a common Abelian gauge field is considered. It is shown that the model has a soliton solution that describes a system consisting of a vortex and a Q-ball. This two-dimensional system is electrically neutral, nevertheless it possesses a nonzero electric field. Moreover, the soliton system has a quantized magnetic flux and a nonzero angular momentum. Properties of this vortex-Q-ball system are investigated by analytical and numerical methods. It is found that the system combines properties of topological and nontopological solitons.

  18. Engine mounts and structural joints

    Indian Academy of Sciences (India)

    perience and intuition. Design requirements for static and dynamic loadings may conflict, as low stresses in joints demand rigid connections, while designs for low vibration and noise often require more compliant joints. In practice, however, no analytical design tools are available to resolve such issues. While finite element ...

  19. A Preliminary Study on Sinus Fungus Ball with MicroCT and X-Ray Fluorescence Technique.

    Science.gov (United States)

    Jiang, Zidong; Zhang, Kai; Huang, Wanxia; Yuan, Qingxi

    2016-01-01

    Sinus fungus ball, an accumulation of fungal dense concretions, is a common disease in practice, and might cause fatal complications or lead to death once converted into invasive type. Early preoperative diagnosis of this disease can lead to appropriate treatment for patients and prevent multiple surgical procedures. Up to now, the diagnostic criteria of sinus fungus ball have been defined and computed tomography (CT) scan was considered as a valuable preoperative diagnostic tool. However, the sensitivity of clinical CT is only about 62%. Thus, investigating the factors which influence sensitivity is necessary for clinical CT to be a more valuable preoperative diagnosis tool. Furthermore, CT scan usually presents micro-calcifications or spots with metallic density in sinus fungus ball. Previous literatures show that there are some metallic elements such as calcium and zinc in fungus ball, and they concluded that endodontic treatment has a strong correlation with the development of maxillary sinus fungus ball and zinc ion was an exogenous risk factor. But the pathogenesis of sinus fungus ball still remains unclear because fungus ball can also develop in other non-maxillary sinuses or the maxillary sinus without root canal treatment. Is zinc ion the endogenous factor? Study on this point might be also helpful for investigating the pathogenesis of sinus fungus ball. In this paper, we tried to investigate the factors which influence the sensitivity of clinical CT by imaging sinus fungus ball with microCT. The origin of zinc ion was also studied through elements test for different fungal ball samples using x-ray fluorescence technique. Specimens including fungal ball material and sinus mucosa from patients confirmed by pathological findings were extracted after surgery. All fungal ball specimens came from sphenoid sinus, ethmoidal sinus and maxillary sinus with or without previous endodontic treatment respectively. All of them were imaged by microCT with spatial

  20. Effect of chromium and aluminum addition on anisotropic and microstructural characteristics of ball milled nanocrystalline iron

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Rajiv, E-mail: rajiv06484met@gmail.com [IITB-Monash Research Academy, Indian Institute of Technology Bombay, Powai, Mumbai 400076 (India); Department of Metallurgical Engineering and Materials Science, Indian Institute of Technology Bombay, Powai, Mumbai 400076 (India); Department of Mechanical and Aerospace Engineering, Monash University, VIC 3800 Australia (Australia); Joardar, Joydip [International Advanced Research Centre for Powder Metallurgy and New Materials, Hyderabad (India); Singh Raman, R.K. [Department of Mechanical and Aerospace Engineering, Monash University, VIC 3800 Australia (Australia); Department of Chemical Engineering, Monash University, VIC 3800 Australia (Australia); Raja, V.S. [Department of Metallurgical Engineering and Materials Science, Indian Institute of Technology Bombay, Powai, Mumbai 400076 (India); Joshi, S.V. [International Advanced Research Centre for Powder Metallurgy and New Materials, Hyderabad (India); Parida, S. [Department of Metallurgical Engineering and Materials Science, Indian Institute of Technology Bombay, Powai, Mumbai 400076 (India)

    2016-06-25

    Prior studies on synthesis of nanocrystalline elements have discussed the effect of ball milling on lattice parameter, crystallite size, and micro-strain. For elemental milled powders, the anisotropic peak broadening does not change with increasing milling time. However, the effect of alloying addition on the anisotropic behavior of ball milled nanocrystalline powders remains an unexplored area. Here we report the effect of chromium and aluminum addition on the anisotropic behavior of iron in nanocrystalline Fe–20Cr–5Al (wt%) alloy powders synthesized by ball milling. The experimental results show that the anisotropic behavior of iron changes towards isotropic with milling. This change was also correlated to the theoretically calculated anisotropic factor from the change in elastic constant of iron due to milling. Addition of alloying elements exhibited a monotonic rise in the lattice parameter with crystallite size, which was attributed to the excess grain boundary interfacial energy and excess free volume at grain boundaries. Transmission electron microscopy image confirmed the crystallite size and nature of dislocation obtained using modified Williamson-Hall method. - Highlights: • Structural evolution in Fe–20Cr–5Al alloy during ball milling is reported. • Effect of alloying addition on the anisotropic behavior of iron was studied. • Agreement in anisotropic factor calculated theoretically and experimentally.

  1. Experimental dry socket: microscopic and molecular evaluation of two treatment modalities Alveolite experimental: análise microscópica e molecular de duas modalidades de tratamento

    Directory of Open Access Journals (Sweden)

    Camila Lopes Cardoso

    2011-10-01

    Full Text Available PURPOSE: To evaluate two treatment modalities of dry socket in rats and to discuss the first findings of the molecular analysis in this experimental model. METHODS: 84 rats underwent a tooth extraction were divided in 4 groups: I-uninfected socket (control, II-infected socket without any treatment, III-infected socket treated with irrigation of 2% sodium iodide and 3% hydrogen peroxide solution, IV-infected socket submitted to curettage, irrigation with physiological saline solution and fulfilled with metronidazole paste as base. The groups were subdivided in postoperative sacrifice periods: 6/15/28 days. A quantitative and a qualitative microscopic analysis was performed. Also, a quantitative analysis was performed using a RealTimePCR to evaluate the genes expression in the wound healing: Collagen Type I/COL-I, vascular endothelial growth factor/VEGF, osteocalcin/OCN, alkaline phosphatase/ALP, runt-related transcription factor 2/RUNX2 and tumor necrosis factor alpha/TNF-α. RESULTS: The group I showed higher bone formation, followed by groups IV, III, II respectively. The group II presented higher inflammatory infiltrate and the wound healing was delayed compared with other groups. It was obtained a significant positive correlation between bone neoformation and the expression of OCN and RUNX2, inflammatory infiltrate with TNF-α and a negative correlation between bone neoformation and TNF-α. CONCLUSION: No significant difference was found between the treatments.OBJETIVO: Avaliar duas modalidades de tratamento da alveolite em ratos e discutir os primeiros achados de uma análise molecular neste modelo experimental. MÉTODOS: 84 ratos foram submetidos a uma extração dentária e foram divididos em quatro grupos: I- alvéolo não infectado (controle, II- alvéolo infectado sem tratamento, III- alvéolo infectado tratado com irrigação de iodeto de sódio a 2% e solução de peróxido de hidrogênio a 3%, IV- alvéolo infectado submetido

  2. A ball-in-ball g-C3N4@SiO2nano-photoreactor for highly efficient H2generation and NO removal.

    Science.gov (United States)

    Lin, Bo; Chen, Sheng; Dong, Fan; Yang, Guidong

    2017-04-20

    The design and construction of a nano-photoreactor with some complexity and elaborate functionalities is a novel and fascinating protocol to highly optimize the performances of a g-C 3 N 4 photocatalyst. Herein, a ball-in-ball structured g-C 3 N 4 @SiO 2 composite nano-photoreactor was synthesized via a nanocasting technique combined with a partial etching technique, which showed diverse application potential in environmental protection and photocatalytic hydrogen evolution. As expected, the as-prepared nano-photoreactor exhibits a superior photocatalytic activity and excellent stability with respect to the above-mentioned aspects, and this enhanced performance could be attributed to its unique structural advantages of multiple scattering and reflecting effects, higher degree of crystallinity, and increased active surface area and porosity. More importantly, the nano-photoreactor provides a decent environment within nanoscale domains for catalytic reaction to greatly accelerate the conversion of reactants.

  3. DESIGN, BUILDING AND VALIDATION OF A BALL-CRATERING WEAR TEST EQUIPMENT BY FREE-BALL TO MEASURE THE COEFFICIENT OF FRICTION

    Directory of Open Access Journals (Sweden)

    Ronaldo Câmara Cozza

    2014-06-01

    Full Text Available The purpose of this work is to present a ball-cratering equipment configuration to measure the coefficient of friction. Two load cells were used to measure, in real time, the “normal” and “tangential” forces during the experiments to calculate the coefficient of friction. Micro-abrasive wear tests were conducted on an AISI H10 tool steel specimen, with a ball of AISI 52100 steel and an abrasive slurry, prepared with SiC and distilled water; different values of normal force and sliding distance were defined for the wear experiments to investigate and validate the constructed machine. The results showed that due to test conditions, it was observed the occurrence of rolling abrasion. The equipment showed excellent functionality and reproducibility, in terms of formation of the wear craters and measurement of the coefficient of friction.

  4. The Use of Light/Chemically Hardened Polymethylmethacrylate, Polyhydroxylethylmethacrylate, and Calcium Hydroxide Graft Material in Combination With Polyanhydride Around Implants and Extraction Sockets in Minipigs: Part II: Histologic and Micro-CT Evaluations

    Science.gov (United States)

    Hasturk, Hatice; Kantarci, Alpdogan; Ghattas, Mazen; Dangaria, Smit J.; Abdallah, Rima; Morgan, Elise F.; Diekwisch, Thomas G.H.; Ashman, Arthur; Van Dyke, Thomas

    2015-01-01

    Background This report is the second part of the previously published study on the impact of light/chemical hardening technology and a newly formulated composite graft material for crestal augmentation during immediate implant placement. Methods A total of 48 implants were placed into the sockets of the mesial roots of freshly extracted mandibular premolar teeth in three minipigs. Crestal areas and intrabony spaces were randomly augmented with light-hardened graft materials including a composite graft consisting of polymethylmethacrylate, polyhydroxylethylmethacrylate, and calcium hydroxide (PPCH) plus polyanhydride (PA); PPCH graft; and PA graft, or left untreated. Distal sockets not receiving implants and the sockets of first molars (n = 60) were randomly treated with one of the graft materials or left empty. In addition, two molar sockets were treated with the original PPCH graft material. Quantitative microcomputed tomography (micro-CT) was used to assess alveolar bone structure and tissue compositions. Histologic evaluations included descriptive histology to assess the peri-implant wound healing, as well as histomorphometric measurements to determine bone-to-implant contact (BIC). Results Both trabecular and cortical bone measurements by micro-CT did not reveal any significant differences among the groups. Sites augmented with PPCH+PA resulted in significantly greater BIC surface than PPCH alone and no-graft-treated implants (P implant surface in the PPCH+PA group, whereas sites without augmentation showed large gaps between bone and implant surfaces, indicating a slower bone apposition and less BIC surface compared to all other groups. Similar to implant sections, all materials showed positive outcome on trabecular and cortical bone formation in extraction sockets with an intact crestal cortical bone. Conclusion Histologic evaluations supported the previous findings on implant stability and function and confirmed that PPCH+PA provides a greater BIC with a

  5. THEORETICAL AND EXPERIMENTAL STUDIES OF ENERGY-EFFICIENT GRINDING PROCESS OF CEMENT CLINKER IN A BALL MILL

    Directory of Open Access Journals (Sweden)

    Kuznetsova M.M.

    2014-08-01

    Full Text Available The article presents results of theoretical and experimental research of grinding process of bulk materials in a ball mill. The new method of determination of energy efficiently mode of operation of ball mills in a process of a cement clinker grinding is proposed and experimentally tested.

  6. (De)synchronization of advanced visual information and ball flight characteristics constrains emergent information-movement couplings during one-handed catching.

    Science.gov (United States)

    Stone, J A; Maynard, I W; North, J S; Panchuk, D; Davids, K

    2015-02-01

    Advance visual information of a projection action and ball flight information is important for organizing dynamic interceptive actions like catching. However, how the central nervous system (CNS) manages the relationship between advance visual information and emerging ball flight information in regulating behavior is less well understood. Here, we sought to examine the extent that advance visual information to the CNS constrains regulation of catching actions by synchronizing and desynchronizing its relationship with ball trajectory characteristics. Novel technology was used to present video footage of an actor throwing a ball at three different speeds, integrated with information from a real ball projected by a machine set to the three speeds. The technology enabled three synchronized and six desynchronized conditions between advance visual information and subsequent ball flight trajectories. Catching performance, kinematic data from the catching hand and gaze behaviors were recorded. Findings revealed that desynchronization of video images of ball projection shaped emergent catching behaviors. Footage of slower throws, paired with faster ball projection speeds, caused catching performance decrements. Timing in early phases of action was organized by the CNS to match the advance visual information presented. In later phases, like the grasp, ball flight information constraints adapted and regulated behaviors. Gaze behaviors showed increased ball projection speed resulted in participants tracking the ball for a smaller percentage of ball flight. Findings highlighted the role of the two visual systems in perception and action, implicating the importance of coupling advanced visual information and ball flight to regulate emergent movement coordination tendencies during interceptive behaviors.

  7. Prosthetic Smart Socket Technology to Improve Patient Interaction, Usability, Comfort, Fit and Function

    Science.gov (United States)

    2017-10-01

    pending. Subcontractor OP Solutions received Western IRB approval. What opportunities for training and professional development has the project...information that supplements, clarifies or supports the text. Examples include original copies of journal articles, reprints of manuscripts and abstracts, a curriculum vitae, patent applications, study questionnaires, and

  8. Smart Adaptive Socket to Improve Fit and Relieve Pain in Wounded Warriors

    Science.gov (United States)

    2016-10-01

    physical connection between the user’s body and the prosthesis . The functionality and comfort of the prosthesis is to a great degree determined by the...be due to the long-term effects of pharmaceuticals, weight gain, or weight loss. Limb volume can also decrease quite noticeably (as much as 11...relatively mild vacuum suspension system, which is also used to control the volume in the liner by evacuating and compressing the foam elements. This system

  9. Medicinal plants in the healing of dry socket in rats: microbiological and microscopic analysis.

    Science.gov (United States)

    de Melo Júnior, E J M; Raposo, M J; Lisboa Neto, J A; Diniz, M F A; Marcelino Júnior, C A C; Sant'Ana, A E G

    2002-03-01

    The effectiveness of medicinal herbs as antimicrobial agents was tested on isolated microorganisms from an induced alveolitis and on alveolitis in rats. Sixteen ethanolic extracts from plants were prepared and tested. The plant materials were selected from ethnobotanic data and the best result was obtained with Schinus terebinthifolius Raddi. The activity on Enterococcus, Bacillus corineforme, Streptococcus viridans and S. beta-hemolytic was better than the one presented by the antibiotic currently used for the treatment of alveolitis. The extract of Schinus terebinthifolius Raddi has shown good wound-healing activity by histological analysis.

  10. Micro Insert Moulding for the Production of 8 Pin RIC Socket for Hearing Aid Applications

    DEFF Research Database (Denmark)

    Islam, Aminul; Hansen, Hans Nørgaard; Larsen, Jacob W.

    This report presents the development of an 8 Pin RIC (Receiver in the canal) Socket for hearing instruments within the framework of the European project COTECH. There were 8 industrial demonstrators developed in COTECH based on the converged product and process design. Sonion’s 8 Pin RIC Socket...

  11. Clinical and radiographic evaluation of immediately loaded one-piece implants placed into fresh extraction sockets.

    Science.gov (United States)

    Soardi, Carlo Maria; Bianchi, Andrea Edoardo; Zandanel, Ezio; Spinato, Sergio

    2012-06-01

    To assess clinical survival and success rates of one-piece implants placed at the time of tooth extraction with immediate provisionalization and to evaluate radiographic peri-implant bone loss around one-piece implants 1 year after functional loading. Forty-six patients (20 men and 26 women) with a mean age of 45.5 years (range, 24 to 74 years) were recruited from four centers for this case series report. Immediately following the extraction of untreatable teeth, all patients received one-piece implants. The implants were immediately restored and placed into function with no occlusal contact. Outcome assessments included clinical and radiographic evaluations. Of the one-piece implants placed after extraction in the maxilla and mandible, 95.7% integrated successfully. The mean marginal bone loss after 1 year was 0.80 mm (SD, 0.53 mm). Overall peri-implant bone loss at maxillary sites was compared with overall bone loss at mandibular sites. At the 1-year follow-up, no statistically significant difference was found. The deeper the implants were placed below the crest, the more marginal bone loss was observed. However, no difference in marginal bone loss was observed as a consequence of the following three variables: implant length (10, 11.5, or 13 mm), implant diameter (3, 3.7, or 4.7 mm); and 3- and 6-month time periods after implant prosthesis placement. Based on data obtained from this sample size study, it can be concluded that one-piece implants can be successfully placed immediately after extraction with minimal peri-implant bone loss.

  12. Smart Adaptive Socket to Improve Fit and Relieve Pain in Wounded Warriors

    Science.gov (United States)

    2017-10-01

    Various designs were created to test the effects of giving either a convex or concave curve to the external walls with the intention of predisposing...significant impact on expenditures Due to delays in IRB approval expenditures related to the clinical trial such as travel and the fabrication of test

  13. Cosmetic effect of knee joint in a knee disarticulation prosthesis

    OpenAIRE

    Fred A. de Laat, MD, PhD; Mark J. van der Pluijm, CPO; Annette A. van Kuijk, MD, PhD; Jan H. Geertzen, MD, PhD; Leo D. Roorda, MD, PT, PhD

    2015-01-01

    Despite numerous advantages, knee disarticulations (KDs) are rarely performed because of the anticipated KD prosthesis fitting problems that include the positioning of the knee joint distally from the KD socket. This results in lengthening of the thigh and subsequent shortening of the shank. The objective of this study was to assess the cosmetic effect of the knee joint in a KD prosthesis by determining the extent of the lengthening of the thigh and the shortening of the shank. This lengtheni...

  14. Chronic Inflammation in an Anophthalmic Socket due to a Room Temperature Vulcanized Silicone Implant

    Directory of Open Access Journals (Sweden)

    Alicia Galindo-Ferreiro

    2016-04-01

    Full Text Available Two case reports are used to illustrate the signs and symptoms, complications and treatments of chronic socket inflammation due to intraorbital implants. The ophthalmic examination, surgeries and treatments are documented. Two anophthalmic cases that underwent enucleation and multiple orbital surgeries to enhance the anophthalmic socket volume developed pain, intense discharge and contracted cavities with chronic inflammation in the socket which was nonresponsive to medical therapy. Computed tomography indicated a hypodense foreign body in both cases causing an intense inflammatory reaction. The implants were removed by excisional surgery and a room temperature vulcanized silicone implant was retrieved in both cases. Socket inflammation resolved in both cases after implant removal. An intraorbital inflammatory reaction against an intraorbital implant can cause chronic socket inflammation in patients with a history of multiple surgeries. Diagnosis requires imaging and the definitive treatment is implant removal.

  15. Modelling of and Conjecturing on a Soccer Ball in a Korean Eighth Grade Mathematics Classroom

    Science.gov (United States)

    Lee, Kyeong-Hwa

    2011-01-01

    The purpose of this article was to describe the task design and implementation of cultural artefacts in a mathematics lesson based on the integration of modelling and conjecturing perspectives. The conceived process of integrating a soccer ball into mathematics lessons via modelling- and conjecturing-based instruction was first detailed. Next, the…

  16. The June surprises: balls, strikes, and the fog of war.

    Science.gov (United States)

    Fried, Charles

    2013-04-01

    At first, few constitutional experts took seriously the argument that the Patient Protection and Affordable Care Act exceeded Congress's power under the commerce clause. The highly political opinions of two federal district judges - carefully chosen by challenging plaintiffs - of no particular distinction did not shake that confidence that the act was constitutional. This disdain for the challengers' arguments was only confirmed when the act was upheld by two highly respected conservative court of appeals judges in two separate circuits. But after the hostile, even mocking questioning of the government's advocate in the Supreme Court by the five Republican-appointed justices, the expectation was that the act would indeed be struck down on that ground. So it came as no surprise when the five opined the act did indeed exceed Congress's commerce clause power. But it came as a great surprise when Chief Justice John Roberts, joined by the four Democrat-appointed justices, ruled that the act could be sustained as an exercise of Congress's taxing power - a ground urged by the government almost as an afterthought. It was further surprising, even shocking, that Justices Antonin Scalia, Anthony Kennedy, Clarence Thomas, and Samuel Alito not only wrote a joint opinion on the commerce clause virtually identical to that of their chief, but that in writing it they did not refer to or even acknowledge his opinion. Finally surprising was the fact that Justices Ruth Bader Ginsburg and Stephen Breyer joined the chief in holding that aspects of the act's Medicaid expansion were unconstitutional. This essay ponders and tries to unravel some of these puzzles.

  17. The Effect of Kick Type on the Relationship between Kicking Leg Muscle Activation and Ball Velocity

    Directory of Open Access Journals (Sweden)

    Ali Onur Cerrah

    2018-03-01

    Full Text Available This study aimed to identify the effects of different kick types on the relationship between kicking leg muscle activation and ball velocity. The muscle activation of selected knee extensor and flexor muscles of 10 amateur soccer players were measured using electromyography during the performance of six maximal soccer kick types. The highest ball velocity was achieved by the instep kick (96.2 km/hr-1, followed by the lofted kick, the inside curve kick, the outside kick, the outside curve kick, and finally the inside kick (81.3 km/hr-1. There were significant positive correlations between muscle activation and ball velocity for the vastus lateralis and lofted (0.765, inside curve (0.792 and instep kicks (0.788, and for the gastrocnemious with the outside kick (0.796. Non-significant correlations between muscle activation and ball velocity exhibited a trend such that they were positive for the vastus medialis and vastus lateralis but negative for the biceps femoris and gastrocnemious for inside-foot-dominated kicks, while this trend was reversed for outside-foot-dominated kicks. According to results, the noted trends can be explained by the change in muscle activation patterns required to orientate the foot for each type of kick; this has implications for players’ training activities.

  18. Influence of ball-milling and annealing conditions on nanocluster characteristics in oxide dispersion strengthened steels

    International Nuclear Information System (INIS)

    Laurent-Brocq, M.; Legendre, F.; Mathon, M.-H.; Mascaro, A.; Poissonnet, S.; Radiguet, B.; Pareige, P.; Loyer, M.; Leseigneur, O.

    2012-01-01

    The characteristics of strengthening nanoclusters (NCs) have a major influence on the mechanical properties of oxide dispersion strengthened (ODS) steels. To determine how to control NC formation, ODS powders are synthesized in different ball-milling and annealing conditions, then characterized by electron probe micro-analysis and small angle neutron scattering. During ball-milling, reactants are dissolved into the metallic matrix until a Ti, Y and O solid solution is formed and then NC nucleation begins. Nucleation is greatly enhanced during the first minutes of annealing at 800 °C without any coarsening afterwards. The intensity and temperature of ball-milling influence this mechanism and thus the characteristics of the formed NC, whereas the nature of reactants, for a given composition, has no impact on NC size and volume fraction. Consequently, to promote the formation of fine and dense dispersion of NC, two main modifications to the usual process are proposed: (i) perform a long and/or intense ball-milling with a limited overheating, and (ii) anneal the as-milled powder at 800 °C before performing the thermo-mechanical treatment.

  19. Is rooftop solar PV at socket parity without subsidies?

    International Nuclear Information System (INIS)

    Hagerman, Shelly; Jaramillo, Paulina; Morgan, M. Granger

    2016-01-01

    Installations of rooftop solar photovoltaic (PV) technology in the United States have increased dramatically in recent years, in large part because of state and federal subsidies. In the future, such subsidies may be reduced or eliminated. From the homeowner's perspective, solar PV is competitive when it can produce electricity at a cost equivalent to the retail electricity rate, a condition sometimes referred to as “socket parity”. In assessing the economic viability of residential solar PV, most existing literature considers only a few locations and fails to consider the differences in PV system cost and electricity prices that exist across the U.S. We combined insolation data from more than 1000 locations, installation costs by region, and county-level utility rates to provide a more complete economic assessment of rooftop solar PV across the U.S. We calculated the break-even electricity prices and evaluated the reductions in installed costs needed to reach socket parity. Among the scenarios considered, we estimate that only Hawaii has achieved socket parity without the use of subsidies. With subsidies, six states reach socket parity, yet widespread parity is still not achieved. We find that high installation costs and financing rates are two of the largest barriers to socket parity. - Highlights: • We evaluate the economic viability of residential rooftop solar PV across the U.S. • Widespread socket parity has not been achieved in the U.S. without subsidies. • Net metering may be critical for the economic viability of rooftop solar PV.

  20. Sport’s selection of volley-ball players: morphological and pedagogical criteria of definition of movement endowments: (information 1

    Directory of Open Access Journals (Sweden)

    Leonid Serhiyenko

    2016-02-01

    Full Text Available Purpose: to define methodology of initial sports selection of young volley-ball players. Material & Methods: methods of theoretical analysis and generalization, bibliographic method of search and study of scientific information, a systematic analysis are turned to account in this work. Results: the article deals with the theoretical model of the mast important factors, which define sports endowments of volley-ball players. It is shown the point estimation of body structure and composition, motor and psychomotor abilities, dynamic possibilities, psychophisiological indices in the prognosis of volley-ball players gifted for high sports results. Conclusions: criteria of high movement endowments of volley-ball players are defined; norms of estimation of motor abilities of valley-ball players on the initial steps of sports selection are given.

  1. Clinical wear of overdenture ball attachments after 1, 3 and 8 years.

    Science.gov (United States)

    Fromentin, Olivier; Lassauzay, Claire; Nader, Samer Abi; Feine, Jocelyne; de Albuquerque, Rubens F

    2011-11-01

    Implant-supported overdentures have become the treatment of choice in restoring complete edentulism, but the types of attachment to assure durable retention are a subject of debate. Ball attachments were reported as a simple treatment, but wear of components was responsible for a decrease in retention. The aim of this retrospective study was to measure the wear of the ball abutment or patrix after three different periods of clinical wear. Sixty-nine specimens of three groups of patrix that were in use for a mean of 12.3 months (group A), 39 months (group B) and 95.6 months (group C) were retrieved from 35 patients and measured on a coordinate measuring machine equipped with a touch trigger probe. Ten unused ball abutments were added as a control (group D). The patrix diameters and any deviation from circularity in different axes were measured. The diameters of groups A, B and C were significantly different from that of group D (control). No statistically significant differences were found between diameter and circularity variations between groups B and C. The maximal amount of diameter reduction was limited to approximately 30 μm, and 90% of diameter loss at the equator due to wear was reached in group B. One, 3 and 8 years of clinical wear reduced significantly the diameters of the ball abutments tested, and the maximal amount of wear was reached after 3 years of clinical use. © 2011 John Wiley & Sons A/S.

  2. The Effect of Therapy Balls on the Classroom Behavior and Learning of Children with Dyslexia

    Science.gov (United States)

    Goodmon, Leilani B.; Leverett, Raven; Royer, Amanda; Hillard, Gracia; Tedder, Tracey; Rakes, Lori

    2014-01-01

    The purpose of this study was to determine if the behavioral and learning benefit found from the use of therapy balls as classroom seats in children with attention deficit and hyperactivity disorder (ADHD) (e.g., Schilling, Washington, Billingsley, & Deitz, 2003) generalizes to children with dyslexia who suffer from similar attention problems…

  3. The Symbolism and Ritual Function of the Middle Classic Ball Game in Mesoamerica

    Science.gov (United States)

    Cohodas, Marvin

    1975-01-01

    A model depicting Mesoamerican religion in terms of the links between time/space and mythic, ritual, and agricultural cycles is presented to illustrate the ritual function of the Mesoamerican ball game as it existed during Middle Classic times at the height of its development. (JC)

  4. Postmatch recovery of physical performance and biochemical markers in team ball sports : a systematic review

    NARCIS (Netherlands)

    Doeven, Steven H; Brink, Michel S; Kosse, Silke J; Lemmink, Koen A P M

    2018-01-01

    Background: Insufficient postmatch recovery in elite players may cause an increased risk of injuries, illnesses and non-functional over-reaching. Objective: To evaluate postmatch recovery time courses of physical performance and biochemical markers in team ball sport players. Study design:

  5. MolPrint3D: Enhanced 3D Printing of Ball-and-Stick Molecular Models

    Science.gov (United States)

    Paukstelis, Paul J.

    2018-01-01

    The increased availability of noncommercial 3D printers has provided instructors and students improved access to printing technology. However, printing complex ball-and-stick molecular structures faces distinct challenges, including the need for support structures that increase with molecular complexity. MolPrint3D is a software add-on for the…

  6. Effects of Offense, Defense, and Ball Possession on Mobility Performance in Wheelchair Basketball

    NARCIS (Netherlands)

    de Witte, Annemarie M. H.; Berger, Monique A. M.; Hoozemans, Marco J. M.; Veeger, Dirkjan H. E. J.; van der Woude, Lucas H. V.

    2017-01-01

    The aim of this study was to determine to what extent mobility performance is influenced by offensive or defensive situations and ball possession and to what extent these actions are different for the field positions. From video analysis, the relative duration of the various wheelchair movements

  7. Effects of offense, defense, and ball possession on mobility performance in wheelchair basketball

    NARCIS (Netherlands)

    De Witte, Annemarie M.H.; Berger, Monique A.M.; Hoozemans, Marco J.M.; Veeger, H.E.J.; van der Woude, Lucas H.V.

    2017-01-01

    The aim of this study was to determine to what extent mobility performance is influenced by offensive or defensive situations and ball possession and to what extent these actions are different for the field positions. From video analysis, the relative duration of the various wheelchair movements

  8. Temporomandibular Joint Anatomy and Derangements

    Directory of Open Access Journals (Sweden)

    Bahadır Odabaş

    2008-01-01

    Full Text Available Temporomandibular joint (TMJ is a diartrodial joint which is located just before the outer ear way and between the mandibular fossa and mandibular condyle. TMJ has rotation and translation movements. Approximately the 30-50 percent of the population has joint click. Most of the patients which have TMJ click may suffer from disc displacement. By the presence of disharmony between TMJ and occlusion and masticatory muscles, natural balance disappears. Therefore the function of the craniomandibular system and the factors that affects dysfunction must be considered when treatment planning is built.

  9. Reliable Mechanochemistry: Protocols for Reproducible Outcomes of Neat and Liquid Assisted Ball-mill Grinding Experiments.

    Science.gov (United States)

    Belenguer, Ana M; Lampronti, Giulio I; Sanders, Jeremy K M

    2018-01-23

    The equilibrium outcomes of ball mill grinding can dramatically change as a function of even tiny variations in the experimental conditions such as the presence of very small amounts of added solvent. To reproducibly and accurately capture this sensitivity, the experimentalist needs to carefully consider every single factor that can affect the ball mill grinding reaction under investigation, from ensuring the grinding jars are clean and dry before use, to accurately adding the stoichiometry of the starting materials, to validating that the delivery of solvent volume is accurate, to ensuring that the interaction between the solvent and the powder is well understood and, if necessary, a specific soaking time is added to the procedure. Preliminary kinetic studies are essential to determine the necessary milling time to achieve equilibrium. Only then can exquisite phase composition curves be obtained as a function of the solvent concentration under ball mill liquid assisted grinding (LAG). By using strict and careful procedures analogous to the ones here presented, such milling equilibrium curves can be obtained for virtually all milling systems. The system we use to demonstrate these procedures is a disulfide exchange reaction starting from the equimolar mixture of two homodimers to obtain at equilibrium quantitative heterodimer. The latter is formed by ball mill grinding as two different polymorphs, Form A and Form B. The ratio R = [Form B] / ([Form A] + [Form B]) at milling equilibrium depends on the nature and concentration of the solvent in the milling jar.

  10. Inter and Intra Positional Differences in Ball Kicking Between U-16 Croatian Soccer Players

    Directory of Open Access Journals (Sweden)

    Ante Rađa

    2016-09-01

    Full Text Available The main goal of this research was to determine inter and intra positional differences in ball kicking speed between U-16 Croatian soccer players. 44 young soccer players (15.7 ± 1.5 years were tested with 8 specific soccer field tests that evaluate kicking velocity by using Pocket radar that was reading the ball velocity in km/h. The tests took place two days in a row; beginning at 8 A.M. Prior to the tests, players warmed up and stretched for 20 minutes (13 minutes of running with and without the ball, 7 minutes of dynamic stretching. Inter positional differences were significant (p ≤ 0.05 between midfielders and defenders in all tests and in one test midfielders scored better than strikers. The fastest kicks were instep kicks when stationary and non-stationary ball was kicked. Shots were taken by midfielders with 106.94±7.07 and 101.61±7.88 km/h respectively. Similar to dominant leg, midfielders also achieved the fastest instep kicks with non-dominant leg (91.44±9.56 km/h. Intra positional differences revealed that soccer kick velocity is one of possible selection tools, because more efficient players in all playing lines shoot faster kicks than less efficient players.

  11. Numerical analysis of two pile caps with sockets embedded, subject the eccentric compression load

    Directory of Open Access Journals (Sweden)

    R. G. Delalibera

    Full Text Available The structural behavior of pile caps with sockets embedded is influenced by interface of column-socket, which can be smooth or rough. With intent to analyze the behavior of two pile caps with embedded socket, considering the friction between the column and the socket, with eccentric normal load, the numerical simulations were carried out, using a program based on the Finite Element Methods (FEM. In the numerical analysis the non-linear behavior of materials was considered, also the friction between the column and the socket. It was considered perfect bond between the reinforcement and the concrete around. It was observed that the embedded length is preponderant factor in the structural behavior of the analyzed element.

  12. Microstructural and Material Quality Effects on Rolling Contact Fatigue of Highly Elastic Intermetallic Ball Bearings

    Science.gov (United States)

    DellaCorte, Christopher; Howard, S. Adam; Thomas, Fransua; Stanford, Malcolm K.

    2016-01-01

    Rolling element bearings made from highly-elastic intermetallic materials (HIM)s, such as 60NiTi, are under development for applications that require superior corrosion and shock resistance. Compared to steel, intermetallics have been shown to have much lower rolling contact fatigue (RCF) stress capability in simplified 3-ball on rod (ASTM STP 771) fatigue tests. In the 3-ball tests, poor material quality and microstructural flaws negatively affect fatigue life but such relationships have not been established for full-scale 60NiTi bearings. In this paper, 3-ball-on-rod fatigue behavior of two quality grades of 60NiTi are compared to the fatigue life of full-scale 50mm bore ball bearings made from the same materials. 60NiTi RCF rods with material or microstructural flaws suffered from infant mortality failures at all tested stress levels while high quality 60NiTi rods exhibited no failures at lower stress levels. Similarly, tests of full-scale bearings made from flawed materials exhibited early surface fatigue and through crack type failures while bearings made from high quality material did not fail even in long-term tests. Though the full-scale bearing test data is yet preliminary, the results suggest that the simplified RCF test is a good qualitative predictor of bearing performance. These results provide guidance for materials development and to establish minimum quality levels required for successful bearing operation and life.

  13. Thermogravimetric and Differential Scanning Calorimetric Behavior of Ball-Milled Nuclear Graphite

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Eung Seon; Kim, Min Hwan; Kim, Yong Wan [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Park, Yi Hyun; Cho, Seung Yon [National Fusion Research Institute, Daejeon (Korea, Republic of)

    2013-10-15

    An examination was made to characterize the oxidation behavior of ball-milled nuclear graphite powder through a TG-DSC analysis. With the ball milling time, the BET surface area increased with the reduction of particle size, but decreased with the chemisorptions of O{sub 2} on the activated surface. The enhancement of the oxidation after the ball milling is attributed to both increases in the specific surface area and atomic scale defects in the graphite structure. In a high temperature gas-cooled reactor, nuclear graphite has been widely used as fuel elements, moderator or reflector blocks, and core support structures owing to its excellent moderating power, mechanical properties and machinability. For the same reason, it will be used in a helium cooled ceramic reflector test blanket module for the ITER. Each submodule has a seven-layer breeding zone, including three neutron multiplier layers packed with beryllium pebbles, three lithium ceramic pebbles packed tritium breeder layers, and a reflector layer packed with 1 mm diameter graphite pebbles to reduce the volume of beryllium. The abrasion of graphite structures owing to relative motion or thermal cycle during operation may produce graphite dust. It is expected that graphite dust will be more oxidative than bulk graphite, and thus the oxidation behavior of graphite dust must be examined to analyze the safety of the reactors during an air ingress accident. In this study, the thermal stability of ball-milled graphite powder was investigated using a simultaneous thermogravimeter-differential scanning calorimeter.

  14. Use of Ethernet and TCP/IP socket communications library routines for data acquisition and control in the LEP RF system

    International Nuclear Information System (INIS)

    Ciapala, E.; Collier, P.; Lienard, P.

    1991-01-01

    A general move is being made at CERN towards the direct connection of intelligent equipment and device controllers to the control room consoles by the use of local Ethernet segments bridged to the main Token Ring networks. Communications is based on standard TCP/IP protocols which allows immediate use of standard software packages. The Data Managers which control the LEP RF accelerating units and transverse feedback systems have recently been connected. The implementation of Ethernet and TCP/IP socket communications routines for RF data acquisition and control is described. The adaptation of almost all of the existing software for RF system control, data acquisition and diagnostics to make use of this means of communication has proved straightforward. Furthermore the transparent transfer of data in the form of 'C' structures from the Data Managers to the control center workstations and other computers has considerably simplified the software required for remote surveillance and data logging with a corresponding increase in speed and reliability

  15. Power/Knowledge for Educational Theory: Stephen Ball and the Reception of Foucault

    Science.gov (United States)

    Wang, Chia-Ling

    2011-01-01

    This paper explores the significance of the concept of power/knowledge in educational theory. The argument proceeds in two main parts. In the first, I consider aspects of Stephen J. Ball's highly influential work in educational theory. I examine his reception of Foucault's concept of power/knowledge and suggest that there are problems in his…

  16. Characterization of intermetallic compounds in Cu-Al ball bonds: layer growth, mechanical properties and oxidation

    NARCIS (Netherlands)

    Kouters, M.H.M.; Gubbels, G.H.M.; O'Halloran, O.; Rongen, R.

    2011-01-01

    In high power automotive electronics copper wire bonding is regarded as most promising alternative for gold wire bonding in 1 st level interconnects and therefore subjected to severe functional requirements. In the Cu-Al ball bond interface the growth of intermetallic compounds may deteriorate the

  17. Learning Method and Its Influence on Nutrition Study Results Throwing the Ball

    Science.gov (United States)

    Samsudin; Nugraha, Bayu

    2015-01-01

    This study aimed to know the difference between playing and learning methods of exploratory learning methods to learning outcomes throwing the ball. In addition, this study also aimed to determine the effect of nutritional status of these two learning methods mentioned above. This research was conducted at SDN Cipinang Besar Selatan 16 Pagi East…

  18. On Lipschitz ball noncollapsing functions and uniform co-Lipschitz mappings of the plane

    Directory of Open Access Journals (Sweden)

    Olga Maleva

    2005-01-01

    Full Text Available We give a sharp estimate on the cardinality of point preimages of a uniform co-Lipschitz mapping on the plane. We also give a necessary and sufficient condition for a ball noncollapsing Lipschitz function to have a point with infinite preimage.

  19. Magnetic flux lines in type-II superconductors and the 'hairy ball' theorem

    DEFF Research Database (Denmark)

    Laver, Mark; Forgan, Edward M.

    2010-01-01

    Many prominent phenomena originate from geometrical effects rather than from local physics. For example, the 'hairy ball' (HB) theorem asserts that a hairy sphere cannot be combed without introducing at least one singularity, and is fulfilled by the atmospheric circulation with the existence...

  20. Magnetic properties of ball-milled TbFe2 and TbFe2B

    Indian Academy of Sciences (India)

    Home; Journals; Bulletin of Materials Science; Volume 27; Issue 2. Magnetic properties of ball-milled ... Keywords. Amorphous materials; intermetallic compounds; magnetic materials; magnetic properties. ... This is explained on the basis of a charge transfer between the boron atoms and the 3d band of Fe. The anisotropy of ...

  1. Analytical and experimental investigation of the static friction regime for rubber-rigid ball contact

    NARCIS (Netherlands)

    Deladi, E.L.; de Rooij, Matthias B.; de Vries, Erik G.; de Vries, Erik G.; Schipper, Dirk J.

    2006-01-01

    The static friction regime is of great importance for systems requiring accurate positioning. The parameters of the static friction regime in terms of static friction force and limiting displacement before gross sliding are investigated for a rubber ball/metal flat configuration. Single-asperity

  2. Method and means for remote removal of guide balls from nuclear reactor control rods

    International Nuclear Information System (INIS)

    Krieg, A.H.

    1988-01-01

    This patent describes a method of remotely removing guide balls from nuclear reactor control rods using a punch mechanism, comprising: (a) providing attachment means in the punch mechanism for attaching the punch mechanism to means for reversibly lowering the punch mechanism over the top of one of the control rods; (b) providing a die within the punch mechanism; (c) providing cylinder means within the punch mechanism operatively connected to the die for axially moving the die in a back-and-forth direction; (d) providing a die block within the punch mechanism cooperating with the die; (e) providing guide means within the punch mechanism for self-aligning the punch mechanism so that the die and the die block are automatically aligned with a first one of the guide balls therebetween when the punch mechanism is lowered over the top of the control rod; (f) lowering the punch mechanism over the control rod so that the die, the die block, and the first guide ball are in alignment; and (g) then operating the cylinder means so that the die advances into the die block, thereby removing the first guide ball from the control rod

  3. 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.

  4. Individual ball possession in soccer.

    Science.gov (United States)

    Link, Daniel; Hoernig, Martin

    2017-01-01

    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.

  5. 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.

  6. Ball lightning burn.

    Science.gov (United States)

    Selvaggi, Gennaro; Monstrey, Stan; von Heimburg, Dennis; Hamdi, Mustapha; Van Landuyt, Koen; Blondeel, Phillip

    2003-05-01

    Ball lightning is a rare physical phenomenon, which is not yet completely explained. It is similar to lightning but with different, peculiar characteristics. It can be considered a mix of fire and electricity, concentrated in a fireball with a diameter of 20-cm that most commonly appears suddenly, even in indoor conditions, during a thunderstorm. It moves quickly for several meters, can change direction, and ultimately disappears. During a great storm, a 28-year-old man and his 5-year-old daughter sustained burn wounds after ball lightning came from the outdoors through a chimney. These two patients demonstrated signs of fire and electrical injuries. The father, who lost consciousness, sustained superficial second-degree burn wounds bilaterally on the zygomatic area and deep second-degree burn wounds on his right hand (total body surface area, 4%). His daughter demonstrated superficial second-degree burn wounds on the left part of the face and deep second-degree and third-degree burn wounds (total body surface area, 30%) on the left neck, both upper arms, and the back. In this article, the authors report the first two cases of burn injuries resulting from ball lightning contact indoors. The literature on this rare phenomenon is reviewed to elucidate the nature of ball lightning. Emphasis is placed on the nature of injuries after ball lightning contact, the therapy used, and the long-term complications.

  7. Joint Performance and Planning System

    Data.gov (United States)

    US Agency for International Development — A joint State/USAID system hosted by State that integrates resource and performance information at the program level and enables more flexible and frequent entry of...

  8. Physical Modeling of Shear Behavior of Infilled Rock Joints Under CNL and CNS Boundary Conditions

    Science.gov (United States)

    Shrivastava, Amit Kumar; Rao, K. Seshagiri

    2018-01-01

    Despite their frequent natural occurrence, filled discontinuities under constant normal stiffness (CNS) boundary conditions have been studied much less systematically, perhaps because of the difficulties arising from the increased number of variable parameters. Because of the lack of reliable and realistic theoretical or empirical relations and the difficulties in obtaining and testing representative samples, engineers rely on judgment and often consider the shear strength of the infilled material itself as shear strength of rock joints. This assumption leads to uneconomical and also sometimes the unsafe design of underground structures, slopes, rock-socketed piles and foundations. To study the effect of infill on the shear behavior of rock joints, tests were performed on the modeled infilled rock joint having different joint roughness under constant normal load (CNL) and CNS boundary conditions at various initial normal stress and varying thickness of the infilled material. The test results indicate that shear strength decreases with an increase in t/ a ratio for both CNL and CNS conditions, but the reduction in shear strength is more for CNL than for CNS condition for a given initial normal stress. The detailed account of the effect of thickness of infilled material on shear and deformation behavior of infilled rock joint is discussed in this paper, and a model is proposed to predict shear strength of infilled rock joint.

  9. Proof testing of ceramic femoral heads for hip joint implants.

    Science.gov (United States)

    Weisse, B; Affolter, C; Koller, R E; Stutz, A

    2010-01-01

    A proof test procedure for the rejection of defective ceramic hip ball heads in the production line is presented. The procedure consists of applying a load to each ceramic ball head. This load, being somewhat higher than the maximum physiological load, should not cause any damage in cases where the highly stressed areas are free of flaws. In this procedure, a polymer ring is positioned inside the ball head bore between a socket and the head of a tie bolt. Once the tie bolt is pulled downwards, the ring creates a radial pressure on the inner bore surface of the ball head. With an iterative approach based on finite element analysis, the proof test design was optimized in order to obtain a stress distribution in the ball head similar to that resulting in in vivo conditions. The calculated results were validated by strain gauge measurements performed on an assembled proof test apparatus. Several polymers were considered for the ring. Ultrahigh-molecular-weight polyethylene (UHMWPE grade RCH 1000) showed the best durability properties and lowest wear rates. The requirement to perform 1000 reruns without significant reduction of stress in the ball head was fulfilled. Although other proof test procedures for ceramic femoral heads already exist, the procedure presented in this article shows advantages concerning maintenance and operating costs.

  10. Energy cost and energy sources of ball routine in rhythmic gymnasts.

    Science.gov (United States)

    Guidetti, L; Baldari, C; Capranica, L; Persichini, C; Figura, F

    2000-04-01

    The energy cost and the different energy sources of competitive rhythmic ball-routines were assessed in nine young elite rhythmic gymnasts (13-16 years of age). The overall energy requirement of ball exercise (VO2eq) was obtained by adding the amount of VO2 during exercise above resting (VO2ex) to the VO2 up to the fast component of recovery (VO2al) and to the energy equivalent of peak blood lactate accumulation (VO2la-) of recovery. The lactate (La) curve up to 25 minutes of recovery always showed La peaks at 3 min after exercise (4.0 +/- 0.4 mmol/l) and values still above rest at 25 min (2.3 +/- 0.5 mmol/l). Although ball routines were short in duration (90 s), the metabolic power requirement was 1.1 times higher than the subject's VO2max. The energy cost (VO2eq) amounted to 81 +/- 5 ml x kg(-1). Higher fractions of VO2eq were VO2ex 49% and VO2al 42%, while the remaining 9% was due to VO2la-. The aerobic source resulted in the most utilized system due to the subjects' high VO2max (52.7 ml x kg(-1) x min(-1)) and anaerobic threshold (LT = 84.4%). The HR and the peak lactate values of ball routine were similar to the values recorded at LT step during treadmill test. Although the HR and VO2 values were significantly correlated (during pre-exercise, exercise, and fast recovery), the exercise intensity derived from HR Kanvonen method during ball routine did not correspond to the % of VO2max.

  11. Osteoarthritis of the Wrist STT Joint and Radiocarpal Joint

    Directory of Open Access Journals (Sweden)

    Ronit Wollstein

    2012-01-01

    Full Text Available Our understanding of wrist osteoarthritis (OA lags behind that of other joints, possibly due to the complexity of wrist biomechanics and the importance of ligamentous forces in the function of the wrist. Scaphotrapeziotrapezoidal (STT OA is common, but its role in wrist clinical pathology and biomechanics is unclear. We identified the prevalence of radiographic STT joint OA in our hand clinic population and defined the relationship between STT and radiocarpal OA in wrist radiographs. One hundred consecutive wrist clinical and radiographic exams were retrospectively reviewed. Radiographs were evaluated for the presence and stage of OA. The mean age was 61.3 (±14.5 years. The radiographic occurrence of STT joint OA was 59% and of radiocarpal (RC OA was 29%. Radiographic STT and RC joint OA were inversely related. Tenderness over the STT joint in physical exam was not associated with OA in the STT or other joints. STT OA in our series was not related to wrist pain. These findings support the discrepancy between radiographic and cadaver findings and clinically significant OA in this joint. The inverse relationship between STT and RC OA, as seen in scapholunate advanced collapse (SLAC wrist, requires further biomechanical study.

  12. Clinical, histologic and histomorphometric evaluation of socket preservation using a synthetic nanocrystalline hydroxyapatite in comparison with a bovine xenograft: a randomized clinical trial.

    Science.gov (United States)

    Gholami, Gholam Ali; Najafi, Babak; Mashhadiabbas, Fatemeh; Goetz, Werner; Najafi, Siamak

    2012-10-01

    The aim of this study was to compare a nanocrystalline hydroxyapatite (NCHA), NanoBone(®) and a deproteinized bovine bone mineral (DBBM), Bio-Oss(®) with a collagen membrane on the horizontal ridge width alterations following tooth extraction, in addition to histologic aspects of the grafted extraction sockets. In this randomized clinical trial, 28 symmetrical, non-molar, extraction sockets using a split-mouth design in 12 patients (eight women and four men; aged 21-60; mean 44.6 ± 11.4 years), were randomly selected in the first group to be grafted with DBBM granules covered with a collagen membrane and in the other group grafted with NCHA covered with a collagen membrane. Following extraction horizontal ridge width was measured using caliper and was blindly compared to the dimensions measured prior to implant placement, at the 6- to 8-month follow-up. Subsequently, a 2 × 6 mm trephine core was obtained with aid of acrylic stent and routine histologic preparation was performed on the specimens. The width of the DBBM group decreased from 7.75 ± 1.55 to 6.68 ± 1.85 mm (P < 0.05), whereas the width of the NCHA group decreased from 7.36 ± 1.94 to 6.43 ± 2.08 mm (P < 0.05). The mean between-group difference did not reach statistical significance (P = 0.62). Furthermore, histologic and histomorphometric analyses revealed 28.63 ± 12.53% vital bone in NCHA group vs. 27.35 ± 12.39% in DBBM group, and no statistically significant difference between the groups (P = 0.68). Socket preservation using either NCHA or DBBM in combination with collagen membrane, results in similar, limited horizontal ridge width alterations following tooth extraction. © 2011 John Wiley & Sons A/S.

  13. Pelvic rotation torque during fast-pitch softball hitting under three ball height conditions.

    Science.gov (United States)

    Iino, Yoichi; Fukushima, Atsushi; Kojima, Takeji

    2014-08-01

    The purpose of this study was to investigate the relevance of hip joint angles to the production of the pelvic rotation torque in fast-pitch softball hitting and to examine the effect of ball height on this production. Thirteen advanced female softball players hit stationary balls at three different heights: high, middle, and low. The pelvic rotation torque, defined as the torque acting on the pelvis through the hip joints about the pelvic superior-inferior axis, was determined from the kinematic and force plate data using inverse dynamics. Irrespective of the ball heights, the rear hip extension, rear hip external rotation, front hip adduction, and front hip flexion torques contributed to the production of pelvic rotation torque. Although the contributions of the adduction and external rotation torques at each hip joint were significantly different among the ball heights, the contributions of the front and rear hip joint torques were similar among the three ball heights owing to cancelation of the two torque components. The timings of the peaks of the hip joint torque components were significantly different, suggesting that softball hitters may need to adjust the timings of the torque exertions fairly precisely to rotate the upper body effectively.

  14. 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...

  15. Determining whether a ball will land behind or in front of you: Not just a combination of expansion and angular velocity

    NARCIS (Netherlands)

    Brouwer, A.M.; Lopez-Moliner, J.; Brenner, E.; Smeets, J.B.J.

    2006-01-01

    We propose and evaluate a source of information that ball catchers may use to determine whether a ball will land behind or in front of them. It combines estimates for the ball's horizontal and vertical speed. These estimates are based, respectively, on the rate of angular expansion and vertical

  16. Lightning ball: experiments on creation and hypotheses (comment on 'Energy density calculations for ball-lightning-like luminous silicon balls' by G S Paiva, J V Ferreira, C C Bastos, M V P dos Santos, A C Pavao)

    Energy Technology Data Exchange (ETDEWEB)

    Shabanov, Gennadii D [B P Konstantinov St. Petersburg Institute of Nuclear Physics, Russian Academy of Sciences, Gatchina, Leningrad region (Russian Federation)

    2010-05-11

    The problems addressed in this paper include estimating: the energy density of luminous silicon balls, the density range of a natural lightning ball, and whether and how the object created and described in the commented paper (Usp. Fiz. Nauk 180 218 (2010) [Phys. Usp. 53 (2) 209 (2010)]) corresponds to the natural phenomenon. (letters to the editors)

  17. LETTERS TO THE EDITORS: Lightning ball: experiments on creation and hypotheses(comment on "Energy density calculations for ball-lightning-like luminous silicon balls" by G S Paiva, J V Ferreira, C C Bastos, M V P dos Santos, A C Pavão)

    Science.gov (United States)

    Shabanov, Gennadii D.

    2010-05-01

    The problems addressed in this paper include estimating: the energy density of luminous silicon balls, the density range of a natural lightning ball, and whether and how the object created and described in the commented paper (Usp. Fiz. Nauk 180 218 (2010) [Phys. Usp. 53 (2) 209 (2010)]) corresponds to the natural phenomenon.

  18. Non-destructive examinations of D247.01 SiC-ball. Gamma scan wires 1 and 2 and SiC-ball 1 through 7

    Energy Technology Data Exchange (ETDEWEB)

    Dassel, G.; Buurveld, H.A.; Plakman, J.C.

    1996-07-01

    In the frame of the KFA programme on Innovative Nuclear Technology SiC-coated graphite spheres have been irradiated in the HFR Petten. With this irradiation two stainless steel gamma scan wires have been irradiated to be able to reconstruct the neutron flux profile during the irradiation and to calculate the absorption of neutrons in the spheres. This report presents the results from the gamma scanning of the two gamma scan wires. Appended are the results from dose rate measurements and weighing of the spheres and gamma spectrometric results from balls 5 and 6. (orig.).

  19. Non-destructive examinations of D247.01 SiC-ball. Gamma scan wires 1 and 2 and SiC-ball 1 through 7

    International Nuclear Information System (INIS)

    Dassel, G.; Buurveld, H.A.; Plakman, J.C.

    1996-07-01

    In the frame of the KFA programme on Innovative Nuclear Technology SiC-coated graphite spheres have been irradiated in the HFR Petten. With this irradiation two stainless steel gamma scan wires have been irradiated to be able to reconstruct the neutron flux profile during the irradiation and to calculate the absorption of neutrons in the spheres. This report presents the results from the gamma scanning of the two gamma scan wires. Appended are the results from dose rate measurements and weighing of the spheres and gamma spectrometric results from balls 5 and 6. (orig.)

  20. 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

  1. Implants placed in fresh extraction sockets in the maxilla: clinical and radiographic outcomes from a 3-year follow-up examination.

    Science.gov (United States)

    Sanz, Mariano; Cecchinato, Denis; Ferrus, Jorge; Salvi, Giovanni E; Ramseier, Christoph; Lang, Niklaus P; Lindhe, Jan

    2014-03-01

    The aim of this prospective, randomized, controlled multicenter study was to determine the 3-year efficacy and stability of the soft and hard tissues at implants with a different geometry that were placed in fresh extraction sockets. Implants with two different configurations, cylindrical (Group A) or conical/cylindrical (Group B) were installed, and healing abutments were attached. Sixteen weeks after implant placement, subjects returned for a re-entry procedure. Prosthetic restorations were delivered 22 weeks after implant placement. Each subject was placed in a 3-year follow-up program, including examinations at yearly visits including various soft tissue and bone level parameters. The percentage of sites that were considered inflamed during the follow-up period was stable and varied between 8.8% and 10.2%. The radiographic examinations documented improved bone levels at the final examination and the mean improvement from baseline (placement of permanent restoration; PR) amounted to 0.17 ± 0.67 mm. More than 70% (54 of 76) of the implants monitored in this study suffered no bone loss during the maintenance period. Moreover, there was an obvious "gain" of interproximal soft tissue volume and at the 3-year examination around 25% of all embrasure gaps were completely filled with "papillae". Both conical/cylindrical and cylindrical implants placed in fresh extraction sockets allowed proper soft and hard tissue healing to occur. At both types of implants, mucosal inflammation was infrequent, marginal bone levels were maintained, and soft tissue volume increased gradually after the placement of the permanent restoration. © 2013 John Wiley & Sons A/S. Published by Blackwell Publishing Ltd.

  2. Development of Sub-Ischial Prosthetic Sockets with Vacuum-Assisted Suspension for Highly Active Persons with Transfemoral Amputations

    Science.gov (United States)

    2013-10-01

    range of motion, increased comfort, and uncompromised control for the transfemoral prosthesis user. Socket design is described and case studies are...Approximately 100 clinical fittings have been conducted with this socket technology. Examples of clinical case studies will be presented...Mallorca, Spain: Subischial Socket Technology: Transfemoral Vacuum Concepts and Case Studies . Invited to present at the ISPO Norway Seminar on “Lower

  3. The relationship between the push off ground reaction force and ball speed in high school baseball pitchers.

    Science.gov (United States)

    Oyama, Sakiko; Myers, Joseph B

    2017-05-05

    Baseball pitching is a sequential movement that requires transfer of momentum from the lower extremity to the throwing arm. Therefore, the ground reaction force (GRF) during push off is suggested to play a roll in production of ball speed. The purpose of this study was to investigate the correlation between GRF characteristics during push off and ball speed in high school baseball pitchers. A total of 52 pitchers performed fast pitches from an indoor pitching mound. A force plate embedded in an indoor mound was used to capture the push off GRF. The GRF characteristics (peak anterior, vertical, and resultant forces, vertical and resultant forces at the time of peak anterior GRF, and impulse produced by the anterior GRF) from the three fastest strike pitches from each pitcher were used for analyses. Spearman's rank correlation coefficients were used to describe the relationships between ball speed and the GRF characteristics. Ball speed was only weakly correlated with peak resultant force (ρ=.32, p=.02), and vertical (ρ=.45, pball speed was not correlated with other variables. The correlation between ball speed and push off force in high school pitchers was weak, especially when compared to what was reported for adult pitchers in other studies. Unlike for adult pitchers, higher push off force is only weakly correlated with ball velocity in high school pitchers, which suggests that training to better utilize body momentum may help high school pitchers improve ball speed.

  4. 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.

  5. Ball game popularity

    OpenAIRE

    Gregorič, Vanja

    2011-01-01

    In the diploma thesis I present ball games and how they are popular among children of 4th and 5th form of primary school. Sport activities play an important role when growing up and it is up to adults to provide children a certain amount of exercise in the pre-school period and during their schooling. It is important that one considers child's age and that the activities are represented through playing. Ball games are included in the curriculum in one of the sets in the first three years. In ...

  6. Decay rates of Gaussian-type I-balls and Bose-enhancement effects in 3+1 dimensions

    International Nuclear Information System (INIS)

    Kawasaki, Masahiro; Yamada, Masaki

    2014-01-01

    I-balls/oscillons are long-lived spatially localized lumps of a scalar field which may be formed after inflation. In the scalar field theory with monomial potential nearly and shallower than quadratic, which is motivated by chaotic inflationary models and supersymmetric theories, the scalar field configuration of I-balls is approximately Gaussian. If the I-ball interacts with another scalar field, the I-ball eventually decays into radiation. Recently, it was pointed out that the decay rate of I-balls increases exponentially by the effects of Bose enhancement under some conditions and a non-perturbative method to compute the exponential growth rate has been derived. In this paper, we apply the method to the Gaussian-type I-ball in 3+1 dimensions assuming spherical symmetry, and calculate the partial decay rates into partial waves, labelled by the angular momentum of daughter particles. We reveal the conditions that the I-ball decays exponentially, which are found to depend on the mass and angular momentum of daughter particles and also be affected by the quantum uncertainty in the momentum of daughter particles

  7. The socket-shield technique: first histological, clinical, and volumetrical observations after separation of the buccal tooth segment – a pilot study.

    Science.gov (United States)

    Bäumer, Daniel; Zuhr, Otto; Rebele, Stephan; Schneider, David; Schupbach, Peter; Hürzeler, Markus

    2015-02-01

    The "socket-shield technique" has shown its potential in preserving buccal tissues. However, front teeth often have to be extracted due to vertical fractures in buccolingual direction. It has not yet been investigated if the socket-shield technique can only be used with intact roots or also works with a modified shield design referring to vertical fracture lines. The aim of this study was to assess histologically, clinically, and volumetrically the effect of separating the remaining buccal root segment in two pieces before immediate implant placement. Three beagle dogs were selected in the study. The third and fourth premolars on both sides of the upper jaw were hemisected and the clinical crown of the distal root was removed. Then, the implant bed preparation was performed into the distal root so that a buccal segment of healthy tooth structure remained. This segment was then separated in a vertical direction into two pieces and implants placed lingual to it. After 4 months of healing, the specimens were processed for histological diagnosis. In a clinical case, the same technique was applied and impressions taken for volumetric evaluation by digital superimposition. The tooth segments showed healthy periodontal ligament on the buccal side. New bone was visible between implant surface and shield as well as inside the vertical drill line. No osteoclastic remodeling of the coronal part of the buccal plate was observed. The clinical volumetric analysis showed a mean loss of 0.88 mm in labial direction with a maximum of 1.67 mm and a minimum of 0.15 mm. The applied modification seems not to interfere with implant osseointegration and may still preserve the buccal plate. It may offer a feasible treatment option for vertically fractured teeth. © 2013 Wiley Periodicals, Inc.

  8. Lectures on constructive approximation Fourier, spline, and wavelet methods on the real line, the sphere, and the ball

    CERN Document Server

    Michel, Volker

    2013-01-01

    Lectures on Constructive Approximation: Fourier, Spline, and Wavelet Methods on the Real Line, the Sphere, and the Ball focuses on spherical problems as they occur in the geosciences and medical imaging. It comprises the author’s lectures on classical approximation methods based on orthogonal polynomials and selected modern tools such as splines and wavelets. Methods for approximating functions on the real line are treated first, as they provide the foundations for the methods on the sphere and the ball and are useful for the analysis of time-dependent (spherical) problems. The author then examines the transfer of these spherical methods to problems on the ball, such as the modeling of the Earth’s or the brain’s interior. Specific topics covered include: * the advantages and disadvantages of Fourier, spline, and wavelet methods * theory and numerics of orthogonal polynomials on intervals, spheres, and balls * cubic splines and splines based on reproducing kernels * multiresolution analysis using wavelet...

  9. Styrofoam-and-Velcro: An Alternative to Ball-and-Stick Models

    Directory of Open Access Journals (Sweden)

    Sawyer Rowan Masonjones

    2014-07-01

    Full Text Available For students learning biology at introductory levels, one of the most significant instructional barriers is their lack of preparation in chemistry. In upper-division college chemistry and biology courses, students employ ball-and-stick models in order to visualize molecular structures, but at the introductory biology level, models are inconsistently used and at the secondary level they are avoided altogether. Traditional ball-and-stick models perform poorly at all levels because they only show bonds, never valence electrons. This poses a problem for students who are visual or kinesthetic learners, as modeling electrons in the bonding process may be critical to understanding the mechanisms behind the biochemical reactions that serve as a foundation for biological concepts. Our molecular modeling kits show the action of valence electrons and correctly deal with the issue of polarity and partial charge, while still illustrating structure and function similarly to ball-and-stick models, allowing students to model nearly every reaction or molecule they may need to learn.  Additionally, this kit will foster model building exercises required as part of the Next Generation Science Standards (http://www.nextgenscience.org/next-generation-science-standards. This model was devloped in conjunction with 'Molecular Twister: A Game for Exploring Solution Chemistry' (JMBE Vol 15, No 1; http://jmbe.asm.org/index.php/jmbe/article/view/652 by the same authors, which uses principles derived from the present paper.

  10. Degenerative Joint Diseases and Neuroinflammation.

    Science.gov (United States)

    Fusco, Mariella; Skaper, Stephen D; Coaccioli, Stefano; Varrassi, Giustino; Paladini, Antonella

    2017-04-01

    Rheumatic and joint diseases, as exemplified by osteoarthritis and rheumatoid arthritis, are among the most widespread painful and disabling pathologies across the globe. Given the continuing rise in life expectancy, their prevalence is destined to grow. Osteoarthritis, a degenerative joint disease, is, in particular, on its way to becoming the fourth leading cause of disability worldwide by 2020, with the rising incidence of obesity in addition to age being important factors. It is estimated that 25% of osteoarthritic individuals are unable to perform daily activities. Accompanying osteoarthritis is rheumatoid arthritis, which is a chronic systemic disease that often causes pain and deformity. At least 50% of those affected are unable to remain gainfully employed within 10 years of disease onset. A growing body of evidence now points to inflammation, locally and more systemically, as a promoter of damage to joints and bones, as well as joint-related functional deficits. The pathogenesis underlying joint diseases remains unclear; however, it is currently believed that cross-talk between cartilage and subchondral bone-and loss of balance between these two structures in joint diseases-is a critical element. This view is amplified by the presence of mast cells, whose dysregulation is associated with alterations of junction structures (cartilage, bone, synovia, matrix, nerve endings, and blood vessels). In addition, persistent activation of mast cells facilitates the development of spinal neuroinflammation mediated through their interaction with microglia. Unfortunately, current treatment strategies for rheumatic and articular disease are symptomatic and do little to limit disease progression. Research now should be directed at therapeutic modalities that target osteoarticular structural elements and thereby delaying disease progression and joint replacement. © 2016 World Institute of Pain.

  11. The Efficacy of Hyaluronic Acid in Postextraction Sockets of ...

    African Journals Online (AJOL)

    2018-01-30

    Jan 30, 2018 ... (HA) administration to surgically remove impacted third molar sockets and measure pain, swelling ... Materials and Methods: The study included a total of 25 healthy patients aged 18‑29 years with asymptomatic bilaterally impacted lower third molars. .... tissue flap was reflected laterally and tooth extraction.

  12. Techniques for Interface Stress Measurements within Prosthetic Sockets of Transtibial Amputees: A Review of the Past 50 Years of Research

    Directory of Open Access Journals (Sweden)

    Ebrahim A. Al-Fakih

    2016-07-01

    Full Text Available The distribution of interface stresses between the residual limb and prosthetic socket of a transtibial amputee has been considered as a direct indicator of the socket quality fit and comfort. Therefore, researchers have been very interested in quantifying these interface stresses in order to evaluate the extent of any potential damage caused by the socket to the residual limb tissues. During the past 50 years a variety of measurement techniques have been employed in an effort to identify sites of excessive stresses which may lead to skin breakdown, compare stress distributions in various socket designs, and evaluate interface cushioning and suspension systems, among others. The outcomes of such measurement techniques have contributed to improving the design and fitting of transtibial sockets. This article aims to review the operating principles, advantages, and disadvantages of conventional and emerging techniques used for interface stress measurements inside transtibial sockets. It also reviews and discusses the evolution of different socket concepts and interface stress investigations conducted in the past five decades, providing valuable insights into the latest trends in socket designs and the crucial considerations for effective stress measurement tools that lead to a functional prosthetic socket.

  13. Behaviour of a Bouncing Ball

    Science.gov (United States)

    Cross, Rod

    2015-01-01

    The bounce of a ball is a seemingly innocuous event that can be used to illustrate many aspects of elementary and even advanced mechanics. Both normal and oblique bounces on a rigid surface are considered in this article, emphasizing qualitative features of the bounce process. If the ball bounces at an oblique angle then it can slide throughout…

  14. Effect of Modifying Prosthetic Socket Base Materials by Adding Nanodiamonds

    Directory of Open Access Journals (Sweden)

    Lifang Ma

    2015-01-01

    Full Text Available The curing process of prosthetic socket base materials requires attention owing to a series of associated problems that are yet to be addressed and solved. However, to date, few relevant studies have been reported. In this paper, nanodiamonds modified with a silane coupling agent were dispersed into a prosthetic socket base material, and the performance of the modified base materials was investigated. Adding a predetermined amount of nanodiamonds to the prosthetic socket base material increased the glass transition temperature, improved the mechanical properties of the cured base material, and reduced the influence of the volatile gas formed during the curing process on the environment. With increasing nanodiamond contents, the glass transition temperature increased and the mechanical properties improved slightly. Owing to the high thermal conductivity of the nanodiamonds, the localized heat, as a result of the curing process, could be dissipated and released. Thus, adding nanodiamonds led to a more uniform temperature field forming in the curing system. This improved the curing process and reduced the formation of volatile monomers, thereby decreasing the adverse impact of the generated volatile gases on the environment. All of these provide a potential strategy for modifying prosthetic socket base materials.

  15. Reflections on a Bouncing Ball

    Science.gov (United States)

    Rohr, Jim; Lopez, Veronica; Rohr, Tyler

    2014-01-01

    While observing the bounce heights of various kinds of sports balls dropped from different heights onto a variety of surfaces, we thought of the following question: Could measurements of drop and bounce heights of balls of different diameters, but of the same material, falling from different heights, but on the same surface, be expressed by a…

  16. Free-throw accuracy and success as a function of ball weight in 9- to 11-year-old male players

    OpenAIRE

    Arias, José Luis

    2012-01-01

    The goal of this study was to analyze whether 9-11 years old children can attain more free-throw accuracy and success by modifying the ball weight in basketball game. The participants were 54 children (age: mean=10.63, SD=0.55 years) from six basketball teams. The participants played four games with each of the following balls: (a) standard ball weight (485 g, 69-71 cm), (b) a lighter ball (440 g, 69-71 cm), and (c) a heavier ball (540 g, 69-71 cm). The procedures adopted in the study were: (...

  17. A vertical ball mill as a new reactor design for biomass hydrolysis and fermentation process

    DEFF Research Database (Denmark)

    de Assis Castro, Rafael Cunha; Mussatto, Solange I.; Conceicao Roberto, Inês

    2017-01-01

    A vertical ball mill (VBM) reactor was evaluated for use in biomass conversion processes. The effects of agitation speed (100–200 rpm), number of glass spheres (0–30 units) and temperature (40–46 °C) on enzymatic hydrolysis of rice straw and on glucose fermentation by a thermotolerant Kluyveromyc...... (hydrolysis and fermentation), the VBM reactor could be efficiently used for biomass conversion into ethanol.......A vertical ball mill (VBM) reactor was evaluated for use in biomass conversion processes. The effects of agitation speed (100–200 rpm), number of glass spheres (0–30 units) and temperature (40–46 °C) on enzymatic hydrolysis of rice straw and on glucose fermentation by a thermotolerant Kluyveromyces...... marxianus strain were separately studied. The results revealed an important role of the spheres during biomass' fiber liquefaction and yeast's fermentative performance. For hydrolysis, the spheres were the only variable with significant positive impact on cellulose conversion, while for fermentation all...

  18. Sir Robert Stawell Ball (1840-1913): Royal Astronomer in Ireland and astronomy's public voice

    Science.gov (United States)

    Chapman, Allan

    2007-11-01

    Nineteenth-century Ireland, and especially Dublin, had a vibrant scientific tradition. And astronomy in particular was seriously cultivated, being part of an Irish tradition extending back to early medieval times. This paper examines principally the career of Sir Robert Stawell Ball, who, while holding three prestigious posts in Ireland, namely those of Andrews Professor at Trinity College, Dublin, Royal Astronomer of Ireland, and Director of the Dunsink Observatory, became famous for his genius as a popular astronomical interpreter, lecturer, and writer. The paper looks at Ball's wider career, the circumstances that provided a receptive market for astronomical information across the English-speaking world, and his massive outreach as both a lecturer and a writer.

  19. Device Rotates Bearing Balls For Inspection

    Science.gov (United States)

    Burley, R. K.

    1988-01-01

    Entire surface of ball inspected automatically and quickly. Device holds and rotates bearing ball for inspection by optical or mechanical surface-quality probe, eddy-current probe for detection of surface or subsurface defects, or circumference-measuring tool. Ensures entire surface of ball moves past inspection head quickly. New device saves time and increases reliability of inspections of spherical surfaces. Simple to operate and provides quick and easy access for loading and unloading of balls during inspection.

  20. Axial bone-socket displacement for persons with a traumatic transtibial amputation: The effect of elevated vacuum suspension at progressive body-weight loads.

    Science.gov (United States)

    Darter, Benjamin J; Sinitski, Kirill; Wilken, Jason M

    2016-10-01

    Elevated vacuum suspension systems use a pump to draw air from the socket with the intent of reducing bone-socket motion as compared to passive suction systems. However, it remains unknown if elevated vacuum suspension systems decrease limb displacement uniformly during transitions from unloaded to full-body-weight support. To compare limb-socket motion between elevated vacuum and passive suction suspension sockets using a controlled loading paradigm. Comparative analysis. Persons with transtibial amputation were assessed while wearing either an elevated vacuum or passive suction suspension socket. Digital video fluoroscopy was used to measure axial bone-socket motion while the limb was loaded in 20% body-weight increments. An analysis of variance model was used to compare between suspension types. Total axial displacement (0%-100% body weight) was significantly lower using the elevated vacuum (vacuum: 1.3 cm, passive suction: 1.8 cm; p vacuum suspension reduced axial limb-socket motion by maintaining position of the limb within the socket during unloaded conditions. Elevated vacuum provided no meaningful improvement in limb-socket motion past initial loading. Excessive bone-socket motion contributes to poor residual limb health. Our results suggest elevated vacuum suspensions can reduce this axial displacement. Visual assessment of the images suggests that this occurs through the reduction or elimination of the air pocket between the liner and socket wall while the limb is unloaded. © The International Society for Prosthetics and Orthotics 2015.

  1. A Discussion On A Physical Model Of Ball Lightning And UFO

    Directory of Open Access Journals (Sweden)

    Ivan L. Bajak

    2017-07-01

    Full Text Available It is proposed that the ball lightning and UFO are analogous objects. The variety of different observations is explained. It is proposed on a uniform basis using a hypothesis that the ball lightning and UFO are created like a spherical capacitor filled by polar molecules mainly and in some cases by various chemicals which influence the final manifest of the object. A mechanism of a formation of the spherical capacitor is discussed. A peculiar behavior like e.g. sudden change of direction of motion shape of disc and possible penetration through wall is explained as a consequence of internal structure of the object. Finally an experimental verification of the hypothesis is suggested.

  2. A novel disturbance-observer based friction compensation scheme for ball and plate system.

    Science.gov (United States)

    Wang, Yongkun; Sun, Mingwei; Wang, Zenghui; Liu, Zhongxin; Chen, Zengqiang

    2014-03-01

    Friction is often ignored when designing a controller for the ball and plate system, which can lead to steady-error and stick-slip phenomena, especially for the small amplitude command. It is difficult to achieve high-precision control performance for the ball and plate system because of its friction. A novel reference compensation strategy is presented to attenuate the aftereffects caused by the friction. To realize this strategy, a linear control law is proposed based on a reduced-order observer. Neither the accurate friction model nor the estimation of specific characteristic parameters is needed in this design. Moreover, the describing function method illustrates that the limit cycle can be avoided. Finally, the comparative mathematical simulations and the practical experiments are used to validate the effectiveness of the proposed method. © 2013 ISA Published by ISA All rights reserved.

  3. Structure of laboratory ball lightning

    Science.gov (United States)

    Ito, Tsuyohito; Tamura, Tomoya; Cappelli, Mark A.; Hamaguchi, Satoshi

    2009-12-01

    Trajectories of self-sustained laboratory ball lightning, generated by arc discharges with silicon, are investigated for understanding the possibility of buoyant flight. Extremely low apparent densities are found, nearly approaching that of standard air. The freely buoyant balls are observed to survive for about 0.1 s, with significantly buoyant balls surviving for several seconds. These ball lightning objects are found to have a density and size that can easily allow them to be carried by a gentle breeze of a few meters per second. The results are interpreted by a model that is an extension of that first proposed by Abrahamson and Dinniss [J. Abrahamson and J. Dinniss, Nature (London) 403, 519 (2000)]. The buoyant behavior of ball lightning seen in our experiments is believed to arise as a result of the formation of a nanoparticle oxide network growing from a molten silicon core.

  4. The Harmonic Bloch and Besov Spaces on the Real Unit Ball by an Oscillation

    Directory of Open Access Journals (Sweden)

    Xi Fu

    2016-01-01

    Full Text Available Let B be the real unit ball in Rn and f∈CN(B. Given a multi-index m=(m1,…,mn of nonnegative integers with |m|=N, we set the quantity supx∈B,y∈E(x,r,x≠y(1-|x|2α(1-|y|2β|∂mf(x-∂mf(y|/|x-y|γ[x,y]1-γ,  x≠y, where 0≤γ≤1 and α+β=N+1. In terms of it, we characterize harmonic Bloch and Besov spaces on the real unit ball. This generalizes the main results of Yoneda, 2002, into real harmonic setting.

  5. Mandibular Denture Base Deformation with Locator and Ball Attachments of Implant-Retained Overdentures.

    Science.gov (United States)

    ELsyad, Moustafa Abdou; Errabti, Hatem Mokhtar; Mustafa, Aisha Zakaria

    2016-12-01

    The aim of this in vitro study was to evaluate and compare mandibular denture base deformation between ball and Locator attachments of implant-retained overdentures. An experimental acrylic model covered with resilient silicone mucosal simulation was constructed. Two laboratory implants were placed in the canine areas of the model. Two duplicate experimental overdentures were constructed and connected to the implants with either ball (GI) or Locator (GII) attachments. To measure overdenture strain around the attachments, 3 strain gauges were attached to the lingual polished surface of the overdentures opposite to the right implant (loading side) 2 mm above the attachment level (Ch1), at the attachment level (Ch2), and 2 mm below the attachment level (Ch3). Another 3 gauges were bonded opposite to the left implant (non-loading side) in the same manner (Ch6, Ch7, and Ch8). To measure strain at the midline of the overdentures, two strain gauges were attached in the midline at 5 mm intervals (Ch4 and Ch5). A universal testing device was used to deliver vertical static load of 50 N unilaterally and bilaterally to the first molar area to measure strain using a multi-channel digital strain meter. During bilateral load application, GII recorded higher compressive strains than GI at the majority of channels. During unilateral load application, GI recorded higher tensile strains at Ch1, Ch2, and Ch3, and GII recorded higher strains than GI at Ch6, Ch7, and Ch8. During bilateral loading the highest strain was concentrated at Ch5 for both groups. During unilateral loading, the highest strain was concentrated at Ch2 for GI, and at Ch5 for GII. Ball attachments for implant-retained overdentures were associated with significant mandibular denture base deformation over the implants compared to Locator attachments. Therefore, denture base reinforcement may be recommended with ball attachmentz to increase fracture resistance of the base. © 2015 by the American College of

  6. Effects of ball milling on microstructures and thermoelectric properties of higher manganese silicides

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Xi [Materials Science and Engineering Program, Texas Materials Institute, The University of Texas at Austin, Austin, TX 78712 (United States); Shi, Li, E-mail: lishi@mail.utexas.edu [Materials Science and Engineering Program, Texas Materials Institute, The University of Texas at Austin, Austin, TX 78712 (United States); Department of Mechanical Engineering, The University of Texas at Austin, Austin, TX 78712 (United States); Zhou, Jianshi; Goodenough, John B. [Materials Science and Engineering Program, Texas Materials Institute, The University of Texas at Austin, Austin, TX 78712 (United States); Department of Mechanical Engineering, The University of Texas at Austin, Austin, TX 78712 (United States)

    2015-08-25

    Highlights: • The already low κ{sub L} of HMS can be suppressed further by decreasing the grain size. • The ball milling process can lead to the formation of secondary MnSi and W/C-rich phases. • The formation of the MnSi ad W/C rich phases is found to suppress the thermoelectric power factor. - Abstract: Bulk nanostructured higher manganese silicide (HMS) samples with different grain size are prepared by melting, subsequent ball milling (BM), and followed by spark plasma sintering (SPS). The effects of BM time on the microstructures and thermoelectric properties of these samples are investigated. It is found that BM effectively reduces the grain size to about 90 nm in the sample after SPS, which leads to a decrease in both the thermal conductivity and electrical conductivity. By prolonging the BM time, MnSi and tungsten/carbon-rich impurity phases are formed due to the impact-induced decomposition of HMS and contamination from the tungsten carbide jar and balls during the BM, respectively. These impurities result in a reduced Seebeck coefficient and increased thermal conductivity above room temperature. The measured size-dependent lattice thermal conductivities agree qualitatively with the reported calculation results based on a combined phonon and diffuson model. The size effects are found to be increasingly significant as temperature decreases. Because of the formation of the impurity phases and a relatively large grain size, the ZT values are not improved in the ball-milled HMS samples. These findings suggest the need of alternative approaches for the synthesis of pure HMS with further reduced grain size and controlled impurity doping in order to enhance the thermoelectric figure-of-merit of HMS via nanostructuring.

  7. Prediction of tar ball formation

    International Nuclear Information System (INIS)

    Khelifa, A.; Gamble, L.

    2006-01-01

    The presence of small tar balls ranging in size from less than a millimetre to 60 centimetres have been observed during cleanup assessment operations following accidental oil spills on water. The tar balls are composed of heavy oil residues and suspended particulate matter (SPM) from the water column. They can be found on shorelines, settled on the seafloor and floating at or near the water surface. Their abundance on the shorelines varies from site to site and depends on the conditions of the spill and mixing conditions. Aggregation between SPM and micro-sized oil droplets occurs naturally in coastal waters and enhances the dispersion of spilled oil. Although tar balls are among the important end states of spilled oil in the marine environment, no model exists to estimate the percentage of the spilled oil that becomes tar balls. This paper offered some insight into the modeling of tar ball formation. Current modeling understanding of oil-SPM aggregate formation was used to predict tar ball formation. The formation of oil droplets was examined with respect to a range of conditions under which the formation of large droplets is expected. The role of aggregation was then presented to demonstrate the effects of concentration and type of SPM on the buoyancy of tar balls. Good agreement was found between modeling results and field data reported in the literature regarding the size and density of tar balls. Oil viscosity and mixing energy were found to be the main factors controlling the formation of tar balls. The aggregation of tar balls with SPM and shoreline material results in significant increases or decreases in density, depending on the type and concentration of SPM. 42 refs., 2 tabs., 6 figs

  8. Mental fatigue alters the speed and the accuracy of the ball in table tennis.

    Science.gov (United States)

    Le Mansec, Yann; Pageaux, Benjamin; Nordez, Antoine; Dorel, Sylvain; Jubeau, Marc

    2017-12-20

    This study aimed at evaluating the effects of mental and muscle fatigue on table tennis performance. Mental fatigue (MF) was induced by completion of 90 minutes of the AX-CPT; muscle fatigue was induced by completion of an eccentric exercise performed with the elbow flexors (biceps fatigue, BF) or the knee extensors (quadriceps fatigue, QF). The control condition consisted of watching a movie. Stroke parameters (speed and accuracy of the ball), as well as feelings of fatigue and force production capacity of the elbow flexors (BF, MF and control conditions) and knee extensors (QF condition), were assessed pre and post fatigue protocols. Feelings of fatigue increased post fatigue protocols. Force production capacity decreased only in the BF and QF conditions. BF and MF induced a decrease in accuracy. This decrease in accuracy was associated with an increased ball speed in the BF condition, and a decreased ball speed in the MF condition. QF had a negligible effect on stroke performance. Our results suggest that both mental fatigue, and muscle fatigue, significantly impair table tennis performance and therefore coaches should take into account both the physical and mental state of table tennis players to optimize performance.

  9. Charged Q-ball dark matter from B and L direction

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Jeong-Pyong; Kawasaki, Masahiro [Institute for Cosmic Ray Research, The University of Tokyo,5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8582 (Japan); Kavli IPMU (WPI), UTIAS, The University of Tokyo,5-1-5 Kashiwanoha, Kashiwa, 277-8583 (Japan); Yamada, Masaki [Institute for Cosmic Ray Research, The University of Tokyo,5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8582 (Japan); Kavli IPMU (WPI), UTIAS, The University of Tokyo,5-1-5 Kashiwanoha, Kashiwa, 277-8583 (Japan); Department of Physics, Tohoku University,Sendai, Miyagi 980-8578 (Japan)

    2016-08-24

    We consider nearly equal number of gauge mediation type charged (anti-) Q-balls with charge of ±α{sup −1}≃±137 well before the BBN epoch and discussed how they evolve in time. We found that ion-like objects with electric charges of +O(1) are likely to become relics in the present universe, which we expect to be the dark matter. These are constrained by MICA experiment, where the trail of heavy atom-like or ion-like object in 10{sup 9} years old ancient mica crystals is not observed. We found that the allowed region for gauge mediation model parameter and reheating temperature have to be smaller than the case of the neutral Q-ball dark matter.

  10. BASE MOVEMENT INFLUENCE OF HITTING BALL USING HAD AND FOOT IN FOOTBALL GAME

    Directory of Open Access Journals (Sweden)

    Midhat Mekić

    2006-06-01

    Full Text Available We had analyzed movements abilities influence on situation movement abilities applied on evaluation of strenght of hitting ball using foot and had football game, played by 13 years old boys. In aim of that we had choose 24 movement facts and 3 situations tests of football game. In those examples we had got rezults which are proof that these about influence of movement element s on rezults in analiyzed test.

  11. Research on Quality Inspection and Sorting On-line System for Bearing Steel Ball

    Directory of Open Access Journals (Sweden)

    Yu Runxiang

    2015-01-01

    Full Text Available To detect the flaws of bearing steel ball and sort its quality on-line, a kind of online quality detecting and sorting system for bearing steel ball is developed, which based on the eddy current inspection theory. The design of scheme, circuit and mechanical structure of the system is described in detail. PSD(Phase Sensitive Detection is applied to pick up the signal of cracks and restrain interferential signal. The flaws will be quantificational analysed based on the X-R orthogonal decomposition technology which include the size and depth information of flaws. By analysing and processing the amplitude and phase of the defect signal, the flaws can be found with high accuracy and low error-detected ratio. ARM and MCU Processor ensures the real-time ability of discriminating algorithm. The CPLD is used for generating reference signal which can be easy to get synchronous with the source signal. It has good properties of real-time to detect the quality of bearing steel ball.

  12. The effect of argon gas pressure on ice ball size and rate of formation.

    Science.gov (United States)

    Sprenkle, Preston C; Mirabile, Gabriella; Durak, Evren; Edelstein, Andrew; Gupta, Mantu; Hruby, Gregory W; Okhunov, Zhamshid; Landman, Jaime

    2010-09-01

    Contemporary cryoablation technology utilizes the Joule-Thomson effect, defined as a change in temperature that results from expansion of a nonideal gas through an orifice or other restriction. We evaluated the effect of initial gas tank pressures on freezing dynamics in a single-probe model and in a multiprobe model using contemporary cryoablation technology. Cryoablation trials were performed in a standardized system of transparent gelatin molds at 25°C. Two sets of trials were performed. The first trial evaluated temperature and ice ball size for a given tank pressure when a single needle was deployed. The second trial recorded ice ball temperatures for each probe when multiple probes were fired simultaneously. Trial 1: The rate of temperature change is directly related to the initial pressure of the gas being released, and the group with the highest starting pressures reached the lowest mean temperature and had the largest mean ice ball size (p probe ablation did not affect the rate of temperature change or final temperature compared with firing a single probe (p > 0.7). In accordance with the Joule-Thomson effect, higher initial gas pressures used for cryoablation in a transparent gel model demonstrate statistically significant lower temperatures, faster decreases in temperature, and formation of larger ice balls than lower gas pressures do. With contemporary technology, multiple simultaneous cryoprobe deployment does not compromise individual probe efficacy. The use of higher initial tank pressures will theoretically help future cryoprobes be more effective, creating a greater volume of cell necrosis and a smaller indeterminate zone.

  13. Nonlinear control via approximate input-output linearization - The ball and beam example

    Science.gov (United States)

    Hauser, John; Sastry, Shankar; Kokotovic, Petar

    1992-01-01

    A study is made of approximate input-output linearization of nonlinear systems which fail to have a well defined relative degree. For such systems, a method is provided for constructing approximate systems that are input-output linearizable. The analysis presented in this note is motivated through its application to a common undergraduate control laboratory experiment, the ball and beam system, where it is shown to be more effective for trajectory tracking than the standard Jacobian linearization.

  14. Micro ball lightning and its accelerator proposed to control natural phenomena

    Energy Technology Data Exchange (ETDEWEB)

    Matsumoto, Taka-aki [Hokkaido Univ., Sapporo (Japan)

    2002-09-01

    Micro Ball Lightning (BL) was recently discovered in laboratory. It was also observed during natural phenomena such as volcanic eruption and earthquake. This paper described a brief review of micro BL observed in laboratory as well as during two natural phenomena. Being based on a hypothesis of that those natural phenomena could have been caused by explosive reactions of micro BL, a potential accelerator of micro BL was proposed to control the natural phenomena. (author)

  15. Micro ball lightning and its accelerator proposed to control natural phenomena

    CERN Document Server

    Matsumoto, T A

    2002-01-01

    Micro Ball Lightning (BL) was recently discovered in laboratory. It was also observed during natural phenomena such as volcanic eruption and earthquake. This paper described a brief review of micro BL observed in laboratory as well as during two natural phenomena. Being based on a hypothesis of that those natural phenomena could have been caused by explosive reactions of micro BL, a potential accelerator of micro BL was proposed to control the natural phenomena. (author)

  16. Enhanced reactivity of boron, through adding nano-aluminum and wet ball milling

    Science.gov (United States)

    Zhang, Baoyun; Huang, Chuan; Yan, Shi; Li, Yanchun; Cheng, Yi

    2013-12-01

    Boron is a significant component of energetic materials due to its high energy release on both a mass and volumetric basis. However, due to long-term exposure in air, boron is easily oxidized to form thick surface oxidation layer which significantly decreases the activity of boron. In this study, we demonstrate the wet high-energy milling method to purify the long-term storage boron and assemble the nanoaluminum and boron together to improve the activity of boron. The results show that after wet ball milling, the surface of boron particles becomes rough, and the aluminum is uniformly distributed on the surface of boron observed by scanning electron microscopy (SEM) and X-ray energy dispersive spectroscopy (EDS), respectively. Determined by simultaneous thermal analysis thermogravimetric-differential scanning calorimetric (TG-DSC) in oxygen, the heat release of boron is 444% higher than the boron without any processing. Combustion analyses of delay compositions consisting of boron powder with and without wet ball milling combined with barium dichromate were conducted to study the reactivity activity. The result shows that the average combustion rate for delay composition containing functionalization boron is 2.4 to 3.4 times than the others containing common boron. Overall, our work demonstrates that wet ball milling with adding nanoaluminum can be used an effective method to improve the reactivity activity of long-storage boron.

  17. Enhanced reactivity of boron, through adding nano-aluminum and wet ball milling

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Baoyun; Huang, Chuan [School of Chemical Engineering, Nanjing University of Science and Technology, Xiao lingwei 200, Nanjing 210094 (China); Yan, Shi [School of Optoelectronics, Beijing Institute of Technology, Nanjing 210094 (China); Li, Yanchun, E-mail: ychunli@gmail.com [School of Chemical Engineering, Nanjing University of Science and Technology, Xiao lingwei 200, Nanjing 210094 (China); Cheng, Yi [School of Chemical Engineering, Nanjing University of Science and Technology, Xiao lingwei 200, Nanjing 210094 (China)

    2013-12-01

    Boron is a significant component of energetic materials due to its high energy release on both a mass and volumetric basis. However, due to long-term exposure in air, boron is easily oxidized to form thick surface oxidation layer which significantly decreases the activity of boron. In this study, we demonstrate the wet high-energy milling method to purify the long-term storage boron and assemble the nanoaluminum and boron together to improve the activity of boron. The results show that after wet ball milling, the surface of boron particles becomes rough, and the aluminum is uniformly distributed on the surface of boron observed by scanning electron microscopy (SEM) and X-ray energy dispersive spectroscopy (EDS), respectively. Determined by simultaneous thermal analysis thermogravimetric–differential scanning calorimetric (TG–DSC) in oxygen, the heat release of boron is 444% higher than the boron without any processing. Combustion analyses of delay compositions consisting of boron powder with and without wet ball milling combined with barium dichromate were conducted to study the reactivity activity. The result shows that the average combustion rate for delay composition containing functionalization boron is 2.4 to 3.4 times than the others containing common boron. Overall, our work demonstrates that wet ball milling with adding nanoaluminum can be used an effective method to improve the reactivity activity of long-storage boron.

  18. RESEARCH ABOUT RESULTS REPRODUTIBILITY AND ABRASIVE PARTICLES FRAGMENTATION IN BALL-CRATERING TESTS

    Directory of Open Access Journals (Sweden)

    Ronaldo Câmara Cozza

    2013-06-01

    Full Text Available The micro-abrasive wear tests by rotating ball (crater wear have played an important role in abrasive wear researches. In this type of test, the contact between a specimen and a ball on rotating motion and abrasive particles supplied between these two elements, results in a crater on the specimen, based on which the abrasive wear behaviour is analysed. The purpose of this work is to study results the reprodutibility and the silicon carbide (SiC abrasive particles fragmentation during micro-abrasive wear tests. Tests were conducted with carburized AISI 1010 steel balls and high speed steel specimens, “with” and “without” titanium nitride (TiN coatings. The abrasive slurry was prepared with black silicon carbide (average particle size of 5 µm and distilled water. Grooving abrasion is related with lower reprodutibility results. For the test conditions of this work, no abrasive particles fragmentation was observed, independently of the sliding distance, what is justified, among others factors, by the low normal force applied.

  19. HIV prevalence and associated risk behaviors in New York City's house ball community.

    Science.gov (United States)

    Murrill, Christopher S; Liu, Kai-Lih; Guilin, Vincent; Colón, Edgar Rivera; Dean, Laura; Buckley, Lisa A; Sanchez, Travis; Finlayson, Teresa J; Torian, Lucia V

    2008-06-01

    We measured HIV seroprevalence and associated risk factors among persons in New York City's house ball community. In 2004 we conducted a venue-based risk-behavior survey and HIV testing in the house ball community. Of the 504 study participants, 67% were male, 14% female, and 18% transgender. Mean age was 24 years (range=15-52 years); 55% were Black, and 40% were Latino. More than 85% of participants had previously been tested for HIV, although only 60% had been tested in the previous 12 months. Of the 84 (17%) persons who tested positive for HIV in our study, 61 (73%) were unaware of their HIV status. A logistic regression analysis on data from 371 participants who had had a male sexual partner in the previous 12 months showed that HIV-infected participants were more likely than were HIV-negative participants to be Black, to be older than 29 years, and not to have been tested for HIV in the previous 12 months. Culturally specific community-level prevention efforts are warranted to reduce risk behaviors and increase the frequency of HIV testing in New York City's house ball community.

  20. Role of Vertical Jumps and Anthropometric Variables in Maximal Kicking Ball Velocities in Elite Soccer Players

    Directory of Open Access Journals (Sweden)

    Rodríguez-Lorenzo Lois

    2016-12-01

    Full Text Available Kicking is one of the most important skills in soccer and the ability to achieve ma ximal kicking velocity with both legs leads to an advantage for the soccer player. This study examined the relationship be tween kicking ball velocity with both legs using anthropometric measurements and vertical jumps (a squat jump (SJ; a countermovement jump without (CMJ and with the arm swing (CMJA and a reactive jump (RJ. Anthropome tric measurements did not correlate with kicking ball velocity. Vertical jumps correlated significantly with kicking ball velocity using the dominant leg only (r = .47, r = .58, r = .44, r = .51, for SJ, CMJ, CMJA and RJ, respectively . Maximal kicking velocity with the dominant leg was significantly higher than with the non-dominant leg (t = 18.0 4, p < 0.001. Our results suggest that vertical jumps may be an optimal test to assess neuromuscular skills involved in kicking at maximal speed. Lack of the relationship between vertical jumps and kicking velocity with the non-dominant leg may reflect a difficulty to exhibit the neuromuscular skills during dominant leg kicking.

  1. The distribution and behaviour of tar balls along the Israeli coast

    Science.gov (United States)

    Golik, Abraham

    1982-09-01

    A fortnightly sampling of tar balls on six beaches along the Israeli coastline between 14 April 1975 and 25 June 1976 showed that the mean content of tar during that period was 3625 g m -1 of beach front. The northern and central parts of the coast were significantly more polluted than the southern part. Between July 1975 and February 1976 the mean tar quantity decreased continuously from 5635 to 1344 g m -1. A comparison of tar quantities on the Israeli beaches with those of other beaches in the world showed that the Israeli beaches are more polluted than those of the west Atlantic coast, are as polluted as other beaches on the eastern coast of the Mediterranean Sea, and are less polluted than the beaches of Alexandria, Egypt, and Paphos, Cyprus. It is suggested that the tar content on the beach is related to the degree of oil pollution in the sea. The closer a beach is to an oil shipping lane or an oil dumping site, the heavier it is polluted. During storms, beach tar balls are pushed by the waves to the back of the beach or, in the case of a cliffed coast, are carried along the shore by the longshore current. When the tar balls reach a gap in the cliff (such as an estuary), they are carried inland by the storm waves. There the tar may become buried or dry, shrink and break into small particles which are then dispersed by the wind.

  2. [Divorce and joint physical custody].

    Science.gov (United States)

    Golse, B

    2014-04-01

    This work first recalls the definition of joint physical custody, as well as the current legal procedure for obtaining it, its practical implementation, the financial implications for parents, and finally some statistics. Some psychological and psychopathological reflections on the impact of divorce on children are then presented before considering the question of joint physically custody with regard to attachment theory and depending on the age of the child (a great caution seems to be required before three years). The article concludes with a brief discussion of parental alienation syndrome. Copyright © 2014. Published by Elsevier SAS.

  3. Some new insights into the history of the Glasgow time ball and time guns

    Science.gov (United States)

    Clarke, David; Kinns, Roger

    2012-03-01

    The 1857 time ball machinery at the Glasgow Sailors' Home was supplied by Alexander McKenzie, mechanist, using a design that had much in common with the 1853 Edinburgh apparatus. It was operated using electrical connections to a mean time clock in the Home. This clock required adjustment by hand each day to compensate for its losing rate. Such manual intervention and lack of independent verification of accuracy under-mined the authority of the signal. The relative prestige of the Glasgow and Edinburgh Observatories was an important issue. There was no telegraphic link between Glasgow Observatory and the City until the end of 1863, but it had been demonstrated as early as October 1855 that a time ball could be dropped by telegraph from Edinburgh. Another Edinburgh initiative in September 1863 using time guns fired from Edinburgh caused offence in Glasgow and the trials were terminated in February 1864. Professor Grant, Director of Glasgow Observatory, argued successfully that a system of slave clocks controlled from Glasgow Observatory would be far superior to either a time ball or time guns which only provided a signal once per day. He won the debate in March 1864.

  4. 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.

  5. Source investigation of the tar balls deposited along the Gujarat coast, India, using chemical fingerprinting and transport modeling techniques

    Digital Repository Service at National Institute of Oceanography (India)

    Suneel, V.; Vethamony, P.; Naik, B.G.; VinodKumar, K.; Sreenu, L.; Samiksha, S.V.; Tai,Y.; Sudheesh, K.

    Deposition of tar balls (TBs) along the south Gujarat coast, situated on the west coast of India (WCI), commonly occurs during the southwest monsoon season. Several offshore oil fields off the Mumbai-Gujarat coast, and refineries along the coast...

  6. Eddy-Current Inspection of Ball Bearings

    Science.gov (United States)

    Bankston, B.

    1985-01-01

    Custom eddy-current probe locates surface anomalies. Low friction air cushion within cone allows ball to roll easily. Eddy current probe reliably detects surface and near-surface cracks, voids, and material anomalies in bearing balls or other spherical objects. Defects in ball surface detected by probe displayed on CRT and recorded on strip-chart recorder.

  7. Evaluation of deformation and fracture characteristics of nuclear reactor materials using ball indentation test technique

    International Nuclear Information System (INIS)

    Byun, T. S.; Hong, J. H.; Lee, B. S.; Park, D. G.; Kim, J. H.; Oh, Y. J.; Yoon, J. H.; Chi, S. H.; Kuk, I. H.; Kwon, D. I.; Lee, J. H.

    1998-05-01

    The present report describes the automated ball indentation test techniques and the results of their applications. The ball indentation test technique is an innovative method for evaluating the key mechanical properties from the indentation load-depth data. In the 1st chapter, the existing technique for evaluating basic deformation (tensile) properties is described in detail, and also the application result of the technique is presented. The through-thickness variations of mechanical properties in SA 508 C1.3 reactor pressure vessel steels were measured using an automated ball indentation (ABI) technique. In the 2nd chapter, a method under development, which is similar to that in the 1st chapter, is new method is based on the theoretical solutions rather than experimental relationships. The result of the application showed that the stress-strain curves of various metals were successfully determined with the method. In the 3rd chapter, a new theoretical model was proposed to estimate the fracture toughness of ferritic steels in the transition temperature region. The key concept of the model is that the indention energy to a critical load is related to the fracture energy of the material. The theory was applied to the reactor pressure vessel (RPV) base and weld metals. (author). 24 refs., 3 tabs., 6 figs

  8. Electron-Ionic Model of Ball Lightening

    OpenAIRE

    Fedosin, Sergey G.; Kim, Anatolii S.

    2001-01-01

    The model of ball lightning is presented where outside electron envelope is kept by inside volume of positive charges. The moving of electron in outside envelope is a reason of strong magnetic field, which controls the state of hot ionized air inside of ball lightning. The conditions of origins of ball lightning are investigated and the values of parameters for ball lightning of maximum power are calculated.

  9. Kicking velocity and physical, technical, tactical match performance for U18 female football players - effect of a new ball

    DEFF Research Database (Denmark)

    Andersen, Thomas B; Bendiksen, Mads; Pedersen, Jens M

    2012-01-01

    We investigated kicking velocity and physical, technical, and tactical match performance for under-18 (U18) female football players and evaluated the effect of using a newly developed lighter smaller ball. Ten regional league teams participated. Maximal ball velocity was 4±1% higher when kicking...... the new ball (NB) compared with the standard ball (SB) in a laboratory testing situation (23.2±0.4 vs. 22.4±0.3 ms(-1); p.05), but lower-limb muscular RPE was lower with NB (4.2±0.4 vs. 5.2±0.3; p.05). High-intensity running decreased (p.05). In conclusion, physiological demands were high in youth female...

  10. The Effect of Ankle Taping to Restrict Plantar Flexion on Ball and Foot Velocity During an Instep Kick in Soccer.

    Science.gov (United States)

    Sasadai, Junpei; Urabe, Yukio; Maeda, Noriaki; Shinohara, Hiroshi; Fujii, Eri

    2015-08-01

    Posterior ankle impingement syndrome is a common disorder in soccer players and ballet dancers. In soccer players, it is caused by the repetitive stress of ankle plantar flexion due to instep kicking. Protective ankle dorsiflexion taping is recommended with the belief that it prevents posterior ankle impingement. However, the relationship between ankle taping and ball-kicking performance remains unclear. To demonstrate the relationship between the restrictions of ankle taping and performance of an instep kick in soccer. Laboratory-based repeated-measures. University laboratory. 11 male university soccer players. The subjects' ankle plantar flexion was limited by taping. Four angles of planter flexion (0°, 15°, 30°, and without taping) were formed by gradation limitation. The subjects performed maximal instep kicks at each angle. The movements of the kicking legs and the ball were captured using 3 high-speed cameras at 200 Hz. The direct linear-transformation method was used to obtain 3-dimensional coordinates using a digitizing system. Passive ankle plantar-flexion angle, maximal plantar-flexion angle at ball impact, ball velocity, and foot velocity were measured. The data were compared among 4 conditions using repeated-measures ANOVA, and the correlations between ball velocity and foot velocity and between ball velocity and toe velocity were calculated. Ankle dorsiflexion taping could gradually limit both passive plantar flexion and plantar flexion at the impact. Furthermore, limitation of 0° and 15° reduced the ball velocity generated by instep kicks. Plantar-flexion-limiting taping at 30° has a potential to prevent posterior ankle impingement without decreasing the ball velocity generated by soccer instep kicks.

  11. Sport’s selection of volley-ball players: morphological and pedagogical criteria of definition of movement endowments: (information 1)

    OpenAIRE

    Serhiyenko, Leonid; Ablikova, Alisa

    2016-01-01

    Purpose: to define methodology of initial sports selection of young volley-ball players. Material & Methods: methods of theoretical analysis and generalization, bibliographic method of search and study of scientific information, a systematic analysis are turned to account in this work. Results: the article deals with the theoretical model of the mast important factors, which define sports endowments of volley-ball players. It is shown the point estimation of body structure and composition...

  12. The effect of combined Moringa oleifera and demineralized freeze-dried bovine bone xenograft on the amount of osteoblast and osteoclast in the healing of tooth extraction socket of Cavia cobaya

    Directory of Open Access Journals (Sweden)

    Rostiny Rostiny

    2016-12-01

    Full Text Available Background: Alveolar bone has an important role in providing support to teeth and dentures. Loss of support caused by alveolar resorption will cause functional and aesthetic problems. Preservation socket using bone graft is one way to maintain the dimensions of the alveolar bone. Moringa oleifera leaf can increase the activity of bone graft in the formation of new bone. Purpose: This study was aimed to evaluate the effect of combined Moringa oleivera leaf extract and demineralized freeze-dried bovine bone xenograft (DFDBBX towards the formation of osteoblasts and osteoclasts in the tooth extraction sockets of cavia cobaya. Method: This study used 28 cavia cobayas divided into four groups. The combination of Moringa oleifera leaf extract and DFDBBX was inducted into the sockets of lower incisor tooth with certain dose in each group, ointment 1 containing PEG (a mixture of PEG 400 and PEG 4000 for control group, ointment 2 containing Moringa oleifera leaf extract and DFDBBX and PEG (at active subtance consentration of 0.5% for group 1, ointment 3 containing Moringa oleifera leaf extract and DFDBBX and PEG (at active substance concentration of 1% for group 2, and Ointment 4 containing Moringa oleifera leaf extract and DFDBBX and PEG (at active substance consentration of 2% for group 3. paraffin block preparations were made for histopathology examination using hematoxylin eosin staining. Result: The results showed that there were significant differences of the number of osteoblasts and osteoclasts in each treatment group (p <0.05. Conclusion: It can be concluded that the combination of Moringa oleifera leaf extract and DFDBBX at 2% cocentration can increase the number of osteoblasts and decrease osteoclasts in the healing of tooth extraction sockets of cavia cobaya.

  13. Effects of a 12 Week SAQ Training Programme on Agility with and without the Ball among Young Soccer Players.

    Science.gov (United States)

    Milanović, Zoran; Sporiš, Goran; Trajković, Nebojša; James, Nic; Samija, Krešimir

    2013-01-01

    The purpose of this study was to determine the effects of a 12 week conditioning programme involving speed, agility and quickness (SAQ) training and its effect on agility performance in young soccer players. Soccer players were randomly assigned to two groups: experimental group (EG; n = 66, body mass: 71.3 ± 5.9 kg; body height: 1.77 ± 0.07 m) and control group (CG; n = 66, body mass: 70.6 ± 4.9 kg; body height: 1.76 ± 0.06 m). Agility performance was assessed using field tests: Slalom; Slalom with ball; Sprint with 90° turns; Sprint with 90° turns with ball; Sprint with 180° turns; Sprint with backward and forward running; Sprint 4 x 5 m. Statistically significant improvements (p agility, with and without the ball, with the exception being the Sprint with backward and forward running. This suggests that SAQ training is an effective way of improving agility, with and without the ball, for young soccer players and can be included in physical conditioning programmes. Key pointsSAQ training appears to be an effective way of improving agility with and without the ball in young soccer playersSoccer coaches could use this training during pre-season and in-season trainingCompared with pre-training, there was a statistically significant improvement in all but one measure of agility, both with and without the ball after SAQ training.

  14. The effect of dimple error on the horizontal launch angle and side spin of the golf ball during putting.

    Science.gov (United States)

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

    2017-02-01

    This study aimed to examine the effect of the impact point on the golf ball on the horizontal launch angle and side spin during putting with a mechanical putting arm and human participants. Putts of 3.2 m were completed with a mechanical putting arm (four putter-ball combinations, total of 160 trials) and human participants (two putter-ball combinations, total of 337 trials). The centre of the dimple pattern (centroid) was located and the following variables were measured: distance and angle of the impact point from the centroid and surface area of the impact zone. Multiple regression analysis was conducted to identify whether impact variables had significant associations with ball roll variables, horizontal launch angle and side spin. Significant associations were identified between impact variables and horizontal launch angle with the mechanical putting arm but this was not replicated with human participants. The variability caused by "dimple error" was minimal with the mechanical putting arm and not evident with human participants. Differences between the mechanical putting arm and human participants may be due to the way impulse is imparted on the ball. Therefore it is concluded that variability of impact point on the golf ball has a minimal effect on putting performance.

  15. Influences of the G2350A polymorphism in the ACE Gene on cardiac structure and function of ball game players

    Directory of Open Access Journals (Sweden)

    Jang Yongwoo

    2012-01-01

    Full Text Available Abstract Background Except for the I/D polymorphism in the angiotensin I-converting enzyme (ACE gene, there were few reports about the relationship between other genetic polymorphisms in this gene and the changes in cardiac structure and function of athletes. Thus, we investigated whether the G2350A polymorphism in the ACE gene is associated with the changes in cardiac structure and function of ball game players. Total 85 healthy ball game players were recruited in this study, and they were composed of 35 controls and 50 ball game players, respectively. Cardiac structure and function were measured by 2-D echocardiography, and the G2350A polymorphism in the ACE gene analyzed by the SNaPshot method. Results There were significant differences in left ventricular mass index (LVmassI value among each sporting discipline studied. Especially in the athletes of basketball disciplines, indicated the highest LVmassI value than those of other sporting disciplines studied (p ACE gene in the both controls and ball game players. Conclusions Our data suggests that the G2350A polymorphism in the ACE gene may not significantly contribute to the changes in cardiac structure and function of ball game players, although sporting disciplines of ball game players may influence the changes in LVmassI value of these athletes. Further studies using a larger sample size and other genetic markers in the ACE gene will be needed.

  16. Molecular-cytogenetic aberrations in B-cell adult acute lymphoblastic leukemia (B-ALL) - frequency and correlation with immunophenotype.

    Science.gov (United States)

    Velizarova, Milena; Popova, Dora; Hadjiev, Evgenii; Aleksandrova, Kamelia; Dimova, Ivanka; Zaharieva, Boriana; Toshkov, Stavri; Staneva, Mimoza; Hodjajik, Djansaran; Penev, Marin; Toncheva, Draga

    2006-09-05

    B-cell acute lymphoblastic leukemia (B-ALL) accounts for 20-30% of acute leukemias in adults. Combined application of data from immunophenotyping, karyotyping and molecular analyses allows a better understanding of this heterogeneous disease. We studied 30 adult patients with newly diagnosed B-ALL by conventional cytogenetics, fluorescent in situ hybridization (FISH) and immunophenotyping analyses. We report statistically significant prevalence of structural aberrations (43%) over numerical changes (17%) (p=0.02). The most frequent structural changes were t(9;22)(q34;q11)/bcr-abl-17%, t(8q24)/C-MYC-10%, t(11q23)/MLL-6%, del 4p-6%, del12p-3%, and t(1;19)-3%. Complex karyotype was found in 17% and normal karyotype in 30%. The most frequent immunophenotype was of common B-ALL (43%), and cytogenetic and/or molecular abnormalities were found in 78% of them. We distinguished a relatively high incidence (17%) of mature B-ALL and 60% of them were associated with t(8;14)/C-MYC. We established association of cytogenetic aberrations with immunophenotype only in mature B-ALL. The other immunophenotypes are characterized by genetic heterogeneity and the presence of cytogenetic abnormalities unusual for adult B-ALL - trisomy 8 and t(1;19)(q23;p13).

  17. Numerical modelling of shear socketed piers

    Science.gov (United States)

    Khan, A.

    2000-09-01

    When a socketed pier embedded in a rock mass is pushed down, the concrete asperities slide over the matching rock asperities. Consequently, the normal stress across the rock-concrete interface increases due to the dilation of the rough contact. The objective of this paper is to model the behaviour of such rough interfaces analytically. A plasticity-based interface model is developed and implemented in a finite element program. Various features of the model such as failure criterion, plastic potential, bond degradation and dilatancy are presented. Interface parameters obtained from laboratory tests are used to simulate the interaction between concrete and rock numerically. A comparison between laboratory observations and numerical predictions is presented.

  18. High expression of PRPS1 induces an anti-apoptotic effect in B-ALL cell lines and predicts an adverse prognosis in Chinese children with B-ALL.

    Science.gov (United States)

    Ma, Yimei; An, Xizhou; Guan, Xianmin; Kong, Qinglin; Wang, Yanzhen; Li, Pengfei; Meng, Yan; Cui, Yinghui; Wen, Xianhao; Guo, Yuxia; Shen, Yali; Yu, Jie

    2018-04-01

    Phosphoribosyl pyrophosphate synthetase 1 (PRPS1) is closely associated with a number of diseases; however, its influence in B-cell acute lymphoblastic leukemia (B-ALL) and the potential molecular mechanisms involved remain unclear. The present study aimed to evaluate the expression of PRPS1 in Chinese children with B-ALL and to investigate the mechanism of action of PRPS1 in this disease. A Cell Counting Kit-8 (CCK-8) assay was performed to examine the proliferation of B-ALL Sup-B15 and Raji cells, and flow cytometric analysis was conducted to determine the cell cycle distribution and rate of apoptosis. The mRNA and protein expression levels of PRPS1, MYC proto-oncogene, bHLH transcription factor, cyclin E1, B-cell lymphoma-2 (Bcl-2), cyclin dependent kinase 2 and caspase-3 were detected by reverse transcription-quantitative polymerase chain reaction and western blot analysis, respectively. Elevated PRPS1 expression was associated with a high-risk stratification and poor prognosis in patients with B-ALL. Furthermore, overexpression of PRPS1 accelerated the growth of and inhibited apoptosis in Sup-B15 and Raji cells as well as increasing the expression of Bcl-2 to induce an anti-apoptotic effect in B-ALL cell lines. The results of the present study indicate that PRPS1 regulates multiple processes in B-ALL and may be an attractive therapeutic target.

  19. Effect of ball milling on structures and properties of dispersed-type dental amalgam.

    Science.gov (United States)

    Chern Lin, Jiin-Huey; Chen, Fred Ying-Yi; Chiang, Hui-Ju; Ju, Chien-Ping

    2011-04-01

    The purpose of the present study was to investigate the effect of ball milling on the initial mercury vapor release rate and mechanical properties such as compressive strength, diametral tensile strength and creep value, of the dispersed-type dental amalgam, and comparison was made with respect to two commercial amalgam alloys. Ball milling was employed to modify the configuration of the originally spherical-shaped Ag-Cu-Pd dispersant alloy particles. Improvement in mechanical properties while maintaining a low early-stage mercury vapor release rate of the amalgam is attempted. The experimental results show that the amalgam (AmB10) which was made from Ag-Cu-Pd dispersant alloy particles that were ball-milled for 10 min and heat-treated at 300 °C for 2 days exhibited a low initial mercury vapor release rate of 69 pg/mm(2)/s, which was comparable with that of commercial amalgam alloy Tytin (68 pg/mm(2)/s), and was lower than that of Dispersalloy (73 pg/mm(2)/s). As for mechanical properties, amalgam AmB10 exhibited the highest 1h compressive strength (228 MPa), which was higher than that of commercial amalgam alloy Dispersalloy by 72%; while its 24h diametral tensile strength was also the highest (177 MPa), and was higher than that of Dispersalloy by 55%. Furthermore, the creep value of the amalgams made from Ag-Cu-Pd alloy particles with 10 min ball-milling and heat treatment at 300 °C for 2 days was measured to be 0.12%, which was about 20% that of Dispersalloy. It is found that ball milling of the dispersant Ag-Cu-Pd alloy particles for 10 min was able to modify the configuration of the alloy particles into irregular-shapes. Subsequently, heat treatment at 300 °C significantly lowered the initial mercury vapor release rate, increased its 1h compressive strength and 1h diametral tensile strength, and lowered its creep value. Copyright © 2010 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  20. Field and Model Study to Define Baseline Conditions of Beached Oil Tar Balls along Florida’s First Coast

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