WorldWideScience

Sample records for ball and socket joints

  1. De Quervain Tenosynovitis Following Trapeziometacarpal Ball-and-Socket Joint Replacement

    OpenAIRE

    Goubau, Jean F.; Goubau, Laurent; Goorens, Chul Ki; van Hoonacker, Petrus; Kerckhove, Diederick; Vanmierlo, Bert; Berghs, Bart

    2015-01-01

    Background One of the surgical treatment options for trapeziometacarpal (TMC) joint arthritis is a prosthetic ball-and-socket replacement. One of the complications in the postoperative setting is de Quervain tendinopathy.

  2. De Quervain Tenosynovitis Following Trapeziometacarpal Ball-and-Socket Joint Replacement.

    Science.gov (United States)

    Goubau, Jean F; Goubau, Laurent; Goorens, Chul Ki; van Hoonacker, Petrus; Kerckhove, Diederick; Vanmierlo, Bert; Berghs, Bart

    2015-02-01

    Background One of the surgical treatment options for trapeziometacarpal (TMC) joint arthritis is a prosthetic ball-and-socket replacement. One of the complications in the postoperative setting is de Quervain tendinopathy. Purposes Although this complication has been reported following a resection athroplasty, we questioned whether lengthening of the thumb following the Ivory (Memometal, Stryker Corporate, Kalamazoo, MI, USA) ball-and-socket arthroplasty could be a causal factor. Methods In a prospective study regarding the overall outcome of the Ivory prosthesis, we analyzed 96 cases (83 patients; 69 female, 12 male, 8 bilateral) of primary implanted Ivory prosthesis and the incidence of de Quervain disease during the first year following surgery. We found a particularly high incidence (17%) of de Quervain tendinopathy the first year following this ball-and-socket arthroplasty. We measured the lengthening of the thumb radiographically in the group presenting de Quervain and the asymptomatic group and compared this measure between the two groups. Results We did not find any measurable or statistically significant difference between the groups regarding lengthening. Discussion These findings suggest that lengthening of the thumb following ball-and-socket arthroplasty is not a causal factor in the development of de Quervain tendinopathy within one year after surgery.

  3. Biomechanical Aspects of Shoulder and Hip Articulations: A Comparison of Two Ball and Socket Joints

    Directory of Open Access Journals (Sweden)

    Mustafa Qusay Ismael

    2006-01-01

    Full Text Available The shoulder and hip joints though essentially both are ball and socket joints, show structural variability to serve functional needs.study aims at revealing some of the structural and functional properties of each of the two joints regarding the factors that contribute to the stability of any joint in the body, namely: bone, ligament, and muscleTwenty dried scapula, hip, humerus, and femur were used. The area of the articular surfaces was estimated by molding a sheet of dental wax. Using special graphics software, a novel procedure was described to calculate the area under the curve, which was postulated to indicate the degree of curvature. Tension test was applied using a testometric machine, which was locally modified to suit biological specimens. A finite element analysis was designed to study the articulating bones under different loading conditionsIn the hip joint, the area of the articular surface of the head of the femur and that of the lunate showed no significant statistical difference. For the shoulder joint, the articular areas of the head of the humerus and the glenoid were statistically different. No statistical significance was observed regarding curvature of the articular surfaces within both the hip and shoulder joints; however, the values were significantly different between the hip and shoulder. In the tension test, the site of rupture of the capsule of the shoulder joint was found to be at its anteroinferior part. The more contact between the area of the cup and ball, as was demonstrated in the hip joint, the more stable the joint. On the contrary, the shoulder articular surfaces have less area of contact, which makes it more mobile and decreases stability. The insignificant difference in curvature within both joints indicates a good congruity and thus more stability especially during joint movement. The curvature difference between the head of femur and the head of humerus indicates that the range of motion is quite

  4. Fretting corrosion behaviour of ball-and-socket joint on dental implants with different prosthodontic alloys.

    Science.gov (United States)

    Gil, F J; Canedo, R; Padrós, A; Bañeres, M V; Arano, J M

    2003-01-01

    The fretting corrosion of five materials for implant suprastructures (cast-titanium, machined-titanium, gold alloy, silver-palladium alloy and chromium-nickel alloy), was investigated in vitro, the materials being galvanically coupled to a titanium ball-and-socket-joint with tetrafluoroethylene under mechanical load. Various electrochemical parameters (E(corr), i(corr), Evans diagrams, polarization resistance and Tafel slopes) were analyzed. The microstructure of the different dental materials was observed before and after corrosion processes by optical and electron microscopy. It can be observed that the mechanical load produces an important decrease of the corrosion resistance. The cast and machined titanium had the most passive current density at a given potential and chromium-nickel alloy had the most active critical current density values. The high gold content alloys have excellent resistance corrosion, although this decreases when the gold content is lower in the alloy. The palladium alloy had a low critical current density due to the presence of gallium in this composition but a selective dissolution of copper-rich phases was observed through energy dispersive X-ray analysis.

  5. The Effect of Mechanical Combined Contact Stress with Buckling Load on the Stress Distribution in the Ball and SocketJoint Mechanism

    Directory of Open Access Journals (Sweden)

    Fatima Salman

    2010-01-01

    Full Text Available The design of components subjected to contact stress as local compressive stress is important in engineering application especially in ball and socket Joining. Two kinds of contact stress are introduced in the ball and socket joint, the first is from normal contact while the other is from sliding contact. Although joining two long links (drive shaft in steering cars will cause the effect of flexural and tensional buckling stress in hollow columns through the ball and socket ends on the failure condition of the joining mechanism. In this paper the consideration of the combined effect of buckling Load and contact stress on the ball and socket joints have been taken, epically on the stress distribution in the contact area. Different parameters have been taken in the design of joint. This is done by changing the angles for applied loads with the principle axis, the angle of contact between ball and socket and using different applied loads. The problem has been solved using analytical solution for computing the critical loads and using these loads for calculating the stress distribution with finite element method using ANSYS 10. The numerical results have been compared with the experimental method using photo elasticity pattern which shows good agreement between experimental and simulation results.

  6. A new principle and device for large aircraft components gaining accurate support by ball joint

    Institute of Scientific and Technical Information of China (English)

    Bao-gui QIU; Jun-xia JIANG; Ying-lin KE

    2011-01-01

    How to obtain an accurate support for large components by ball joint is a key process in aircraft digital assembly. A novel principle and device is developed to solve the problem. Firstly, the working principle of the device is introduced. When three or four displacement sensors installed in the localizer are touched by the ball-head, the spatial relation is calculated between the large aircraft component's ball-head and the localizer's ball-socket. The localizer is driven to achieve a new position by compensation. Relatively, a support revising algorithm is proposed. The localizer's ball-socket approaches the ball-head based on the displacement sensors. According to the points selected from its spherical surface, the coordinates of ball-head spherical center are computed by geometry. Finally, as a typical application, the device is used to conduct a test-fuselage's ball-head into a localizer's ball-socket. Positional deviations of the spherical centers between the ball-head and the ball-socket in the x, y, and z directions are all controlled within ±0.05 mm under various working conditions. The results of the experiments show that the device has the characteristics of high precision, excellent stability, strong operability, and great potential to be applied widely in the modern aircraft industry.

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

    Science.gov (United States)

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

    2014-10-01

    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 (μ<0.05), and friction may have approached zero during dynamic rupture. Here we show that the inward-dipping Hoshab fault defines the northern rim of a structural unit in southeast Makran that rotates - akin to a 2-D ball-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.

  8. Wear-testing of a temporomandibular joint prosthesis : UHMWPE and PTFE against a metal ball, in water and in serum

    NARCIS (Netherlands)

    Van Loon, JP; Verkerke, GJ; de Bont, LGM; Liem, RSB

    1999-01-01

    For a temporomandibular joint prosthesis, an estimation of the wear rate was needed, prior to patient application. Therefore, we determined the in vitro wear rate of the ball-socket articulation of this prosthesis, consisting of a metal head and an ultra-high molecular weight polyethylene (UHMWPE) c

  9. Kinematic characteristics analysis of rolling ball joint socket nozzle%滚动球窝喷管运动性能分析

    Institute of Scientific and Technical Information of China (English)

    刘文芝; 任毅斌; 刘仲民; 庞明思; 赵永忠

    2014-01-01

    The motion force,complexity deformation and immeasurability of the mechanism are key problems in the system de-sign and performance requirement,when the ball,concave sphere,convex sphere and supporting body are under the rolling body con-tact impacting,in the rolling ball joint socket nozzle of a certain solid propellant rocket motor. In order to solve the dynamic perform-ance problems of the system,Spalart-Allmaras turbulence model was used in the calculation of nozzle flow field to simulate the igni-tion test and obtain the system thrust. Coupled rigid and flexible multi-body dynamics model was established. Characteristics of mo-tion on the system parts,contact stress and deformation were computed and analyzed. Analysis results verify rationality of system de-sign and kinematic characteristics in the pre-research state. A practical and feasible way for design of solid propellant rocket motor thrust vector control system was provided.%某固体火箭发动机滚动球窝喷管运动过程中,其接头内部和阴球、阳球及支撑体在滚动体的接触碰撞作用下,运动及受力、变形状态复杂,无法试验测量,是系统结构设计和功能发挥的关键问题。为解决系统运动性能,模拟热试车试验,采用单方程湍流模型计算喷管内流场,得到系统推力;建立系统刚柔耦合多体动力学模型,计算分析系统及接头内部主要构件的运动规律、接触应力及变形。在预研阶段,以检验系统结构设计和运动性能的合理性,同时为机械类固体火箭发动机推力向量控制系统的研制提供更实用和可行的理论分析方法。

  10. Patient satisfaction and preference with magnet, bar-clip, and ball-socket retained mandibular implant overdentures : A cross-over clinical trial

    NARCIS (Netherlands)

    Cune, Marco; van Kampen, Frits; van der Bilt, Andries; Bosman, Frits

    2005-01-01

    Purpose: The purposes of this study were to: (1) determine patient satisfaction with implant-supported mandibular overdentures using magnet, bar-clip, and ball-socket attachments; and (2) assess the relation between maximum bite force and patient satisfaction. Materials and Methods: In a cross-over

  11. Temporomandibular joint dislocation and deafness from a cricket ball injury.

    Science.gov (United States)

    Murthy, P; Bandasson, C; Dhillon, R S

    1994-05-01

    Cricket is a national sport in some countries and can be potentially hazardous. We report an incident of a cricket ball impact to the chin, which resulted in posterior dislocation of both temporomandibular joints and bilateral mixed deafness. There appear to be no similar case reports in the literature.

  12. 2D Ball-and-Socket Tectonic Rotation in a Heterogeneous Strain Field: The 2013 Mw7.7 Balochistan, Pakistan Earthquake

    Science.gov (United States)

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

    2014-12-01

    The September 2013 Mw7.7 Balochistan strike-slip earthquake ruptured a ~200 km long segment of the curved Hoshab fault within the Makran accretionary prism - the active zone of convergence between the northward subducting Arabia plate and overriding Eurasia. The Hoshab fault ruptured bilaterally with ~10 m of mean sinistral and ~1.7 m of dip slip along the length of the rupture, quantified jointly from geodetic and seismological observations. This rupture is unusual because the fault dips ~60o towards the focus of a small circle centered in northwest Pakistan, and, despite a 30o increase in obliquity along the curving strike of the fault with respect to Arabia:Eurasia convergence, the ratio of strike and dip slip remain relatively uniform. Static friction prior to rupture was unusually weak ( <0.05) as inferred from topographic and slab profiles, and friction may have approached zero during dynamic rupture, thus permitting in part this unusual event. In this presentation, we argue that the northward dipping Hosab fault defines the northern rim of a structural unit in southeast Makran. This unit rotates - akin to a 2-D ball-and-socket joint - counter clockwise in response to India's penetration into the Eurasia plate. According to this interpretation, the mechanically weak Makran accretionary prism is subjected to a highly heterogeneous strain and deforms in response to convergence from both the Arabia and India plates. Rotation of the southeast Makran block accounts for complexity in the Chaman fault system and, in principle, reduces the seismic potential near Karachi by accommodating some slip along the southern Ornach-Nal fault. At the same time, geological indicators and along-strike fault slip profiles indicate that the Hoshab fault may also slip as a reverse fault in response to Arabia:Eurasia convergence - indicating that a single fault may accommodate multiple components of strain partitioning in a heterogeneous strain field over several seismic cycles.

  13. 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 (μChaman 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.

  14. 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

  15. 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 wi

  16. Strength evaluation of prosthetic check sockets, copolymer sockets, and definitive laminated sockets

    Directory of Open Access Journals (Sweden)

    Michael L. Haynes, MS

    2012-04-01

    Full Text Available A prosthesis encounters loading through forces and torques exerted by the person with amputation. International Organization for Standardization (ISO standard 10328 was designed to test most lower-limb prosthetic components. However, this standard does not include prosthetic sockets. We measured static failure loads of prosthetic sockets using a modified ISO 10328 and then compared them with the criteria set by this standard for other components. Check socket (CS strengths were influenced by thickness, material choice, and fabrication method. Copolymer socket (CP strengths depended on thickness and fabrication methods. A majority of the CSs and all of the CPs failed to pass the ISO 10328 ductile loading criterion. In contrast, the strengths of definitive laminated sockets (DLs were influenced more by construction material and technique. A majority of the DLs failed to pass the ISO 10328 brittle loading criterion. Analyzing prosthetic sockets from a variety of facilities demonstrated that socket perfor-mance varies considerably between and within facilities. The results from this article provide a foundation for understanding the quality of prosthetic sockets, some insight into possible routes for improving the current care delivered to patients, and a comparative basis for future technology.

  17. Tensile strength and impact resistance properties of materials used in prosthetic check sockets, copolymer sockets, and definitive laminated sockets

    OpenAIRE

    Maria J. Gerschutz, PhD; Michael L. Haynes, MS; Derek M. Nixon, BS; James M. Colvin, MS

    2011-01-01

    Prosthetic sockets serve as the interface between people with amputations and their prostheses. Although most materials used to make prosthetic sockets have been used for many years, knowledge of these materials' properties is limited, especially after they are subjected to fabrication processes. This study evaluated tensile and impact properties of the current state-of-the-art materials used to fabricate prosthetic check sockets, copolymer sockets, and definitive laminated sockets. Thermolyn...

  18. Tensile strength and impact resistance properties of materials used in prosthetic check sockets, copolymer sockets, and definitive laminated sockets

    Directory of Open Access Journals (Sweden)

    Maria J. Gerschutz, PhD

    2011-10-01

    Full Text Available Prosthetic sockets serve as the interface between people with amputations and their prostheses. Although most materials used to make prosthetic sockets have been used for many years, knowledge of these materials' properties is limited, especially after they are subjected to fabrication processes. This study evaluated tensile and impact properties of the current state-of-the-art materials used to fabricate prosthetic check sockets, copolymer sockets, and definitive laminated sockets. Thermolyn Rigid and Orfitrans Stiff check socket materials produced significantly lower tensile strength and impact resistance than polyethylene terephthalate glycol (PETG. Copolymer socket materials exhibited greater resistance to impact forces than the check socket materials but lower tensile strengths than PETG. The heated molding processes, for the check socket and copolymer materials, reduced both tensile strength and elongation at break. Definitive laminated sockets were sorted according to fabrication techniques. Nyglass material had significantly higher elongation, indicating a more ductile material than carbon-based laminations. Carbon sockets with pigmented resin had higher tensile strength and modulus at break than nonpigmented carbon sockets. Elongation at yield and elongation at break were similar for both types of carbon-based laminations. The material properties determined in this study provide a foundation for understanding and improving the quality of prosthetic sockets using current fabrication materials and a basis for evaluating future technologies.

  19. Process Design of a Ball Joint, Considering Caulking and Pull-Out Strength

    Directory of Open Access Journals (Sweden)

    Bong-Su Sin

    2014-01-01

    Full Text Available A ball joint for an automobile steering system is a pivot component which is connected to knuckle and lower control arm. The manufacturing process for its caulking comprises spinning and deforming. In this study, the process was simulated by flexible multibody dynamics. The caulking was evaluated qualitatively through numerical analysis and inspecting a plastically deformed shape. The structural responses of a ball joint, namely, pull-out strength and stiffness, are commonly investigated in the development process. Thus, following the caulking analysis, the structural responses were considered. In addition, three design variables related to the manufacturing process were defined, and the effects of design variables with respect to pull-out strength, caulking depth, and maximum stress were obtained by introducing the DOE using an L9 orthogonal array. Finally, the optimum design maximizing the pull-out strength was suggested. For the final design, the caulking quality and the pull-out strength were investigated by making six samples and their tests.

  20. Transfemoral socket design and suspension options.

    Science.gov (United States)

    Kapp, S L

    2000-08-01

    The transfemoral socket is the interface between the patient's residual limb and the remaining prosthesis. Whether the patient uses a technologically advanced knee mechanism and foot or a single axis, constant friction knee and solid ankle cushioned heel, no other prosthetic component is as crucial in assuring a comfortable and well-functioning prosthesis as the socket. This article discusses the rationale of quadrilateral and ischial containment socket designs and reviews suspension options.

  1. A novel double-ball-bar with two spatial linkages and one spherical joint

    Science.gov (United States)

    Zhu, Yewen; Wang, Wen; Zhang, Min; Lu, Keqing; Fan, Zongwei; Shi, Guang

    2016-01-01

    As a typical comprehensive error measurement method, the double-ball-bar (DBB) has been invented and used widely for evaluating and diagnosing the accuracy of NC machine tools. However, due to the expansion length of DBB's bar is very limited, the working efficiency of the DBB is greatly reduced and different length bars are mostly used to realize different measurement ranges. In this paper, a novel DBB with two spatial linkages and one spherical joint was presented to implement a wide detection range and simplify the operation. The structure of the proposed device was firstly introduced. The working principle of the device was then described, and the mathematical model for detecting machine's accuracy was also built. According to the angle of spatial linkages and lengths of two bars, circular motions trajectory which is caused by interpolation movement of two shafts can be calculated and compared with theoretical value to evaluate machine tool's accuracy. Finally, the simulation was done to validate the feasibility of the proposed device. The results show that the proposed DBB has reasonable structures. Moreover, the measuring range can cover a large region of space and it is continuous.

  2. 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 compl

  3. Below knee prosthetic socket designs and suspension systems.

    Science.gov (United States)

    Edwards, M L

    2000-08-01

    The prosthetic socket must act as a customized connection between the residual limb's surrounding tissues and the prosthetic components. The socket must be designed to control weight bearing, suspension, and ambulation stability. When making a below-the-knee socket, the prosthetist attempts to maximize loading and minimize displacements, such as vertical, transverse, or rotational. This article discusses the engineering designs or shapes of the two basic forms of below-the-knee prosthetic sockets used today.

  4. Finite element modeling of the contact interface between trans-tibial residual limb and prosthetic socket.

    Science.gov (United States)

    Lee, Winson C C; Zhang, Ming; Jia, Xiaohong; Cheung, Jason T M

    2004-10-01

    Finite element method has been identified as a useful tool to understand the load transfer mechanics between a residual limb and its prosthetic socket. This paper proposed a new practical approach in modeling the contact interface with consideration of the friction/slip conditions and pre-stresses applied on the limb within a rectified socket. The residual limb and socket were modeled as two separate structures and their interactions were simulated using automated contact methods. Some regions of the limb penetrated into the socket because of socket modification. In the first step of the simulation, the penetrated limb surface was moved onto the inner surface of the socket and the pre-stresses were predicted. In the subsequent loading step, pre-stresses were kept and loadings were applied at the knee joint to simulate the loading during the stance phase of gait. Comparisons were made between the model using the proposed approach and the model having an assumption that the shape of the limb and the socket were the same which ignored pre-stress. It was found that peak normal and shear stresses over the regions where socket undercuts were made reduced and the stress values over other regions raised in the model having the simplifying assumption.

  5. Socket Interface Pressure and Amputee Reported Outcomes for Comfortable and Uncomfortable Conditions of Patellar Tendon Bearing Socket: A Pilot Study.

    Science.gov (United States)

    Safari, Mohammad Reza; Tafti, Nahid; Aminian, Gholamreza

    2015-01-01

    The objectives of the current study were to compare intra-socket pressure differences between comfortable and uncomfortable socket conditions, and the usefulness of subject perception of satisfaction, activity limitations, and socket comfort in distinguishing between these two socket conditions. Five unilateral trans-tibial amputees took part in the study. They answered the Socket Comfort Score (SCS) and Trinity Amputation and Prosthetic Experience Scale (TAPES) questionnaires before the interface pressure (in standing and walking) was measured for the uncomfortable socket condition at five regions of the residual limb. Participants were then provided with a comfortable socket and wore it for two weeks. Participants who were satisfied with the socket fit after two weeks repeated the SCS and TAPES questionnaires and interface pressure measurements. The differences between the test results of the two conditions were not statistically significant, except for the interface pressure at the popliteal region during the early stance phase, TAPES socket fit subscale, and the SCS. Due to large variability of the data and the lack of statistical significance, no firm conclusion can be made on the possible relationship between the interface pressure values and the patient-reported outcomes of the two socket conditions. A larger sample size and longer acclimation period are required to locate significant differences.

  6. Single-Rooted Extraction Sockets: Classification and Treatment Protocol.

    Science.gov (United States)

    El Chaar, Edgar; Oshman, Sarah; Fallah Abed, Pooria

    2016-09-01

    Clinicians have many treatment techniques from which to choose when extracting a failing tooth and replacing it with an implant-supported restoration and when successful management of an extraction socket during the course of tooth replacement is necessary to achieve predictable and esthetic outcomes. This article presents a straightforward, yet thorough, classification for extraction sockets of single-rooted teeth and provides guidance to clinicians in the selection of appropriate and predictable treatment. The presented classification of extraction sockets for single-rooted teeth focuses on the topography of the extraction socket, while the protocol for treatment of each socket type factors in the shape of the remaining bone, the biotype, and the location of the socket whether it be in the mandible or maxilla. This system is based on the biologic foundations of wound healing and can help guide clinicians to successful treatment outcomes.

  7. Dry Socket: Incidence, Clinical Features, and Predisposing Factors

    Directory of Open Access Journals (Sweden)

    Babatunde O. Akinbami

    2014-01-01

    Full Text Available Background. Dry socket is a global phenomenon. The purpose of the study was to investigate the incidence of dry socket in recent times in a Nigerian Tertiary Hospital. Methods. Patients who were referred for dental extractions were included in the study. The case files of patients were obtained and information retrieved included biodata, indication for extraction, number and type of teeth extracted, oral hygiene status, compliance to oral hygiene instructions, and development of dry socket. Results. One thousand, one hundred and eighty two patients with total of 1362 teeth extracted during the 4-year period of the study were analyzed, out of which 1.4% teeth developed dry socket. The mean age (SD was 35.2 (16.0 years. Most of the patients who presented with dry socket were in the fourth decade of life. Mandibular teeth were affected more than maxillary teeth. Molars were more affected. Retained roots and third molars were conspicuous in the cases with dry socket. Conclusion. The incidence of dry socket in our centre was lower than previous reports. Oral hygiene status, lower teeth, and female gender were significantly associated with development of dry socket. Treatment with normal saline irrigation and ZnO eugenol dressings allowed relief of the symptoms.

  8. 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).

  9. An experimental comparative study between polypropylene and laminated lower limb prosthetic socket

    Directory of Open Access Journals (Sweden)

    .Haider F. Neama, M.Sc

    2007-01-01

    Full Text Available Most researchers concentrate their studies on the design, stress and pressure distributions of the prosthetic socket. A little attention is considered for the stiffness of the various materials of the prosthetic sockets. Prosthetic laminated sockets in Iraq are costly to be manufactured while polypropylene socket is relatively cheap in comparing with the laminates. Experimental study is conducted to compare the stiffness of five prosthetic sockets made of different materials. Compression, three point flexural and tensile tests are implemented by the Testometric machine. The laminate sockets give better results in compression than polypropylene. Polypropylene gives good results in bending compared with the laminate sockets. When the socket loads are mainly in compression i.e. the low activity level patients, it seems that any of the tested sockets could be used, however, when the load will be not only in compression but in flexion as well i.e. high activity patients, socket No.1 and 5 could be used

  10. Porosity in collapsible Ball Grid Array solder joints

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, C.A. [Univ. of California, Berkeley, CA (United States). Dept. of Materials Science and Mineral Engineering]|[Lawrence Berkeley National Lab., Berkeley, CA (United States). Materials Science Div.

    1998-05-01

    Ball Grid Array (BGA) technology has taken off in recent years due to the increased need for high interconnect density. Opposite to all the advantages BGA packages offer, porosity in collapsible BGA solder joints is often a major concern in the reliability of such packages. The effect of pores on the strength of collapsible BGA solder-joints was studied by manufacturing samples with different degrees of porosity and testing them under a shear load. It was found that the shear strength of the solder joints decreased in a linear fashion with increasing porosity. Failure occurred by internal necking of the interpore matrix. It was confirmed that entrapment of flux residues leads to porosity by manufacturing fluxless samples in a specially made furnace, and comparing them with samples assembled using flux. Also, contamination of Au electrodeposits (in substrate metallization) was determined to cause significant porosity. It was found that hard-Au (Co hardened Au) electrodeposits produce high degrees of porosity even in the absence of flux. Finally, increasing the time the solder spends in the molten state was proven to successfully decrease porosity.

  11. Prosthetics and Orthotics Manufacturing Initiative (POMI) Phase Zero Final Report: Recommendations on Composite Socket Fabrication Based upon Experimental Results

    Science.gov (United States)

    2009-06-20

    Introduction 1 Background 1 Socket Fabrication 1 Vacuum Assisted Resin Transfer Molding ( VARTM ) 3 Socket Manufacturing versus Traditional VARTM 4 Flat Panel...Background Sockets are fabricated using techniques which are similar to Vacuum Assisted Resin Transfer Molding ( VARTM ). A discussion of socket fabrication...traditional VARTM processing, and the important differences between the two, will provide an important background. Socket Fabrication A positive

  12. 承插焊接接头超声相控阵检测技术%Ultrasonic Phased Array Inspection Technology of Socket Welded Joint

    Institute of Scientific and Technical Information of China (English)

    罗宏建; 周重回; 张杰

    2011-01-01

    In order to inspect the imerior default of the socket welded joint, ultrasonic phased array was applied based on developing the artificial defect block. The advantage and the prospect of ultrasonic phased array inspecting in socket welded joint were discussesed.%针对承插焊接接头内部缺陷无法检测的难题,研制了人工模拟裂纹试块,制定了相控阵检测工艺,并分析了相控阵的检测结果,评述了相控阵检测该类结构的优势及其应用前景.

  13. Low-Friction, High-Stiffness Joint for Uniaxial Load Cell

    Science.gov (United States)

    Lewis, James L.; Le, Thang; Carroll, Monty B.

    2007-01-01

    A universal-joint assembly has been devised for transferring axial tension or compression to a load cell. To maximize measurement accuracy, the assembly is required to minimize any moments and non-axial forces on the load cell and to exhibit little or no hysteresis. The requirement to minimize hysteresis translates to a requirement to maximize axial stiffness (including minimizing backlash) and a simultaneous requirement to minimize friction. In practice, these are competing requirements, encountered repeatedly in efforts to design universal joints. Often, universal-joint designs represent compromises between these requirements. The improved universal-joint assembly contains two universal joints, each containing two adjustable pairs of angular-contact ball bearings. One might be tempted to ask why one could not use simple ball-and-socket joints rather than something as complex as universal joints containing adjustable pairs of angularcontact ball bearings. The answer is that ball-and-socket joints do not offer sufficient latitude to trade stiffness versus friction: the inevitable result of an attempt to make such a trade in a ball-and-socket joint is either too much backlash or too much friction. The universal joints are located at opposite ends of an axial subassembly that contains the load cell. The axial subassembly includes an axial shaft, an axial housing, and a fifth adjustable pair of angular-contact ball bearings that allows rotation of the axial housing relative to the shaft. The preload on each pair of angular-contact ball bearings can be adjusted to obtain the required stiffness with minimal friction, tailored for a specific application. The universal joint at each end affords two degrees of freedom, allowing only axial force to reach the load cell regardless of application of moments and non-axial forces. The rotational joint on the axial subassembly affords a fifth degree of freedom, preventing application of a torsion load to the load cell.

  14. Discharge and infection in retinoblastoma post-enucleation sockets

    Science.gov (United States)

    Mourits, Daphne L; Hartong, Dyonne T; Budding, Andries E; Bosscha, Machteld I; Tan, H Stevie; Moll, Annette C

    2017-01-01

    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 (Pprosthesis-wearing patients often experienced mucoid discharge, and less often irritation and socket infection. These complaints were found to decrease with increasing age, but did not seem to be influenced by cleaning or wearing habits. Symptomatic sockets, with and without discharge, were correlated with the presence of pathogenic bacteria for which local antibiotic treatment seemed effective in most cases. PMID:28280296

  15. 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.

  16. Relationship Between the Range of Motion and Isometric Strength of Elbow and Shoulder Joints and Ball Velocity in Women Team Handball Players.

    Science.gov (United States)

    Schwesig, René; Hermassi, Souhail; Wagner, Herbert; Fischer, David; Fieseler, Georg; Molitor, Thomas; Delank, Karl-Stefan

    2016-12-01

    Schwesig, R, Hermassi, S, Wagner, H, Fischer, D, Fieseler, G, Molitor, T, and Delank, K-S. Relationship between the range of motion and isometric strength of elbow and shoulder joints and ball velocity in women team handball players. J Strength Cond Res 30(12): 3428-3435, 2016-The aims of this study were to investigate relationships between isometric strength and range of motion (ROM) of shoulder and elbow joints and compare 2 different team handball throwing techniques in women team handball. Twenty highly experienced women team handball players (age: 20.7 ± 2.9 years; body mass: 68.4 ± 6.0 kg; and height: 1.74 ± 0.06 m) participated in this study. The isometric strength (hand-held dynamometer) and ROM (goniometer) of shoulder and elbow joints were measured at the beginning of the preseasonal training. After clinical examination, the subjects performed 3 standing throws with run-up (10 m) and 3 jump throws over a hurdle (0.20 m). The mean ball velocity was calculated from 3 attempts and measured using a radar gun. The results showed that the ball velocity of the standing throw with run-up (vST) was significantly higher than that of the jump throw (vJT) (25.5 ± 1.56 vs. 23.2 ± 1.31 m·s; p strength in the shoulder was the only parameter with relevant correlations to both throws (vST: r = 0.52, and vJT: r = 0.43). Other relevant relationships to vJT were found for adduction strength shoulder (r = 0.55) and ROM flexion elbow (r = -0.54). The vST was only correlated to the glenohumeral internal rotation deficit. As a consequence, strength is more important than the ROM, and in addition to this, the shoulder, compared with the elbow, has a greater influence on the vST in highly experienced women team handball players.

  17. 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

  18. QUICK ASSESSMENT METHODOLOGY FOR RELIABILITY OF SOLDER JOINTS IN BALL GRID ARRAY (BGA)ASSEMBLY--PART Ⅱ: RELIABILITY EXPERIMENT AND NUMERICAL SIMULATION

    Institute of Scientific and Technical Information of China (English)

    史训清; John HL Pang; 杨前进; 王志平; 聂景旭

    2002-01-01

    In the present study, a facility, i.e., a mechanical deflection system(MDS), was established and applied to assess the long-term reliability of the solder joints in plastic ball grid array (BGA) assembly. It was found that the MDS not only quickly assesses the long-term reliability of solder joints within days, but can also mimic similar failure mechanisms in accelerated thermal cycling (ATC) tests.Based on the MDS and ATC reliability experiments, the acceleration factors (AF)were obtained for different reliability testing conditions. Furthermore, by using the creep constitutive relation and fatigue life model developed in part I, a numerical approach was established for the purpose of virtual life prediction of solder joints.The simulation results were found to be in good agreement with the test results from the MDS. As a result, a new reliability assessment methodology was established as an alternative to ATC for the evaluation of long-term reliability of plastic BGA assembly.

  19. Life Prediction of Ball Grid Array Soldered Joints under Thermal Cycling Loading by Fracture Mechanics Method

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Fatigue crack propagation life of ball grid array (BGA) soldered joints during thermal cycling loading was investigated by fracture mechanics approach using finite element analysis. The relationships between the strain energy release rate (G) and crack size (α), thermal cycle numbers (N) can be derived. Based on the relationships, fatigue life of the soldered joints was determined. The results showed that crack propagation life was higher than crack initiation life. Therefore, it appears that it is more appropriate to predict the fatigue life of soldered joints using the fracture mechanics method.

  20. Transfemoral sockets with vacuum-assisted suspension comparison of hip kinematics, socket position, contact pressure, and preference: Ischial containment versus brimless

    OpenAIRE

    Jason T. Kahle, MSMS, CPO, FAAOP; M. Jason Highsmith, PT, DPT, PhD, CP, FAAOP

    2013-01-01

    The objective of this study was to investigate the effect of brimless compared with ischial ramus containment (IRC) prosthetic sockets when using vacuum-assisted suspension (VAS) on persons with a unilateral transfemoral amputation (TFA). A randomized crossover design with a 2 d accommodation was used. People with unilateral TFA (n = 9 analyzed) were enrolled. Interventions were IRC VAS and brimless VAS sockets. Main outcome measures included coronal hip angle and vertical and lateral socket ...

  1. Relationship between socket pressure and EMG of two muscles in trans-femoral stumps during gait.

    Science.gov (United States)

    Hong, Jung Hwa; Mun, Mu Seong

    2005-04-01

    The biomechanical interaction between the leg stump and the prosthetic socket is critical in achieving close-to-normal ambulation. Although many investigations have been performed to understand the biomechanics of trans-tibial sockets, few studies have measured the socket interface pressure for transfemoral amputees. Furthermore, no report has examined how the residual muscle activities in the transfemoral stump affect the socket interface pressure characteristics during gait. In this study, an experimental method was developed to measure the trans-femoral socket interface pressures and EMG of muscles in the stumps of two trans-femoral amputees. Also, the measurement of three-dimensional prosthetic locomotion was synchronized to understand detailed socket biomechanics. Based on the experimental results, a significant correlation (P socket-interface pressure changes during ambulation.

  2. Load transfer mechanics between trans-tibial prosthetic socket and residual limb--dynamic effects.

    Science.gov (United States)

    Jia, Xiaohong; Zhang, Ming; Lee, Winson C C

    2004-09-01

    The effects of inertial loads on the interface stresses between trans-tibial residual limb and prosthetic socket were investigated. The motion of the limb and prosthesis was monitored using a Vicon motion analysis system and the ground reaction force was measured by a force platform. Equivalent loads at the knee joint during walking were calculated in two cases with and without consideration of the material inertia. A 3D nonlinear finite element (FE) model based on the actual geometry of residual limb, internal bones and socket liner was developed to study the mechanical interaction between socket and residual limb during walking. To simulate the friction/slip boundary conditions between the skin and liner, automated surface-to-surface contact was used. The prediction results indicated that interface pressure and shear stress had the similar double-peaked waveform shape in stance phase. The average difference in interface stresses between the two cases with and without consideration of inertial forces was 8.4% in stance phase and 20.1% in swing phase. The maximum difference during stance phase is up to 19%. This suggests that it is preferable to consider the material inertia effect in a fully dynamic FE model.

  3. Residual (ghost) sockets in bisphosphonate use--evidence of poor healing and slow bone turnover.

    Science.gov (United States)

    Shetty, Kishore; Bouquot, J

    2009-01-01

    Patients taking bisphosphonate drug therapy have demonstrated extremely poor alveolar bone healing after relatively minor oral surgical procedures. It would seem logical that extraction sockets could remain visible radiographically for an extended period after surgery, even in cases with soft tissue healing. This article chronicles the case of a patient who had been taking zoledronic acid chronically for metastatic cancer and who demonstrated numerous residual sockets (also known as ghost sockets), with lamina dura outlines that were visible radiographically.

  4. Review of the socket design and interface pressure measurement for transtibial prosthesis.

    Science.gov (United States)

    Pirouzi, Gh; Abu Osman, N A; Eshraghi, A; Ali, S; Gholizadeh, H; Wan Abas, W A B

    2014-01-01

    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.

  5. 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.

  6. 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.

  7. Comparison of CAD-CAM and hand made sockets for PTB prostheses.

    Science.gov (United States)

    Köhler, P; Lindh, L; Netz, P

    1989-04-01

    The aim of the present study was to compare sockets for below-knee (BK) prostheses made by Computer Aided Design-Computer Aided Manufacture (CAD-CAM) to those made by hand. The patients in the study were provided with two prostheses each, which apart from the sockets, were identical. One socket was made by the CAD-CAM technique developed at the Bioengineering Centre, Roehampton, University College London and one was made by hand at the OT-Centre, Stockholm, Sweden. The results were based on investigation of eight unilateral below-knee amputees evaluating their own sockets by Visual Analogous Scale with respect to comfort, pressure, and pain. The sockets were evaluated on seven occasions, at two tests, on delivery, after use every second day for six days and every second week for two weeks. All CAD-CAM sockets except one had to be changed once as compared to the hand made of which only two had to be changed. As to comfort it could not be demonstrated that there was any significant difference between the two types of sockets and both types were well accepted by all patients. Differences in pressure and pain were rarely reported. There were obvious differences between the two types of socket with respect to height, width, and inner surface configuration. The authors feel that CAD-CAM will in the near future be an excellent tool for design and manufacture of prosthetic sockets.

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

    Directory of Open Access Journals (Sweden)

    Randall D. Alley, CP, LP

    2011-07-01

    Full Text Available 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.

  9. In Vivo Verification of Different Hip Joint Center Estimation Methods in Gait Analysis For Healthy Subjects

    Directory of Open Access Journals (Sweden)

    Abdollah YOUSEFI

    2015-01-01

    Full Text Available Hip joint is one of the most stable joints in human body. It has intrinsic stability provided by its relatively rigid ball and socket configuration. The hip joint also has a wide range of motion, which allows normal locomotion and daily activities. Location of hip joint center (HJC is an important parameter in gait analysis, biomechanical and clinical research laboratories to calculate human lower extremity kinematics and kinetics. Inaccuracies in estimation of hip joint center are shown to propagate errors in kinematic and kinetic calculations of lower extremities

  10. Rehabilitation of an Infected Eye with an Acrylic Ball Implant and a Custom made Scleral Ocular Prosthesis.

    Science.gov (United States)

    Anantharaju, Abhilash; Kamath, Giridhar; Rao K, Suhas; Naik, Deepak S

    2013-09-01

    This clinical report describes the prosthetic rehabilitation of a patient with corneal abscess with endophthalmitis of the left eye. Infection with a history of trauma resulted in loss of vision but with intact eye ball movements. Cornea excising evisceration was carried out following placement of poly(methyl methacrylate) ocular ball implant. Later custom made scleral prosthesis was fabricated to maintain functional integrity of the socket and to satisfy patient's aesthetic needs.

  11. Design of Socket Based on Intelligent Control and Energy Management

    Directory of Open Access Journals (Sweden)

    Jiang Feng

    2015-10-01

    Full Text Available Smart home is one of the main applications of internet of things, and it will realize the intellectualization of household. Smart socket is part of the smart home, which can be controlled remotely by power supplied, monitor utilization condition, communication network and other functions. This article mainly introduces the intelligent electrical outlet of each hardware modules; software part mainly analyzes the socket’s communication mechanism, and the electricity consumption of collected power statistics through diagrams to feedback through wireless communication. Things achieved in an environment of communication between the user and the smart power outlet timely feedback to the user, so as to achieve energy-saving purposes.

  12. Distributed Object-Oriented Architectures Sockets, Java RMI and CORBA

    CERN Document Server

    Stepisnik, Josef

    2007-01-01

    This document intends to offer a detailed discussion of selected distributed object-oriented architectures at conceptual level.The first part of the discussion offers a comprehensive overview of the Socket architecture in Java 2 and Berkeley UNIX and the distributed object model of Java Remote Method Invocation and the Common Object Request Broker Architecture.The second part concludes the discussion with a comparative study of selected features with emphasis on the Common Object Request Broker Architecture and Java Remote Method Invocation.Major Issues Includeˇ The TCP/IP Pro

  13. Current transfemoral sockets.

    Science.gov (United States)

    Schuch, C M; Pritham, C H

    1999-04-01

    Clinicians have two types of prosthetic sockets for patients with a transfemoral amputation: the quadrilateral socket introduced in the 1950s and the ischial containment socket introduced in the 1980s. For many years, the quadrilateral socket was acceptable to clinicians and patients alike. With the introduction of the ischial containment socket claims were made that the quadrilateral socket had been inadequate from its inception. It also was claimed that the ischial containment design was the answer to all problems than patients with transfemoral amputations may have. Unfortunately, there is only one scientific study that lends any support to claims of the ischial containment socket's superiority and its findings are limited. Still, clinicians must make recommendation and prescription decisions daily regarding what is best for their patients. There are two acceptable socket designs for patients with transfemoral amputations. Experience with both supports the concept that they have more similarities than differences and that each has a legitimate place in the treatment of patients with transfemoral amputations. A comprehensive understanding of each socket design and its biomechanical intentions is essential for successful clinical application and treatment of patients with amputations.

  14. Finite element analysis of the contact interface between trans-femoral stump and prosthetic socket.

    Science.gov (United States)

    Zhang, Linlin; Zhu, Ming; Shen, Ling; Zheng, Feng

    2013-01-01

    Transfemoral amputees need prosthetic devices after amputation surgery, and the interface pressure between the residual limb and prosthetic socket has a significant effect on an amputee's satisfaction and comfort. The purpose of this study was to build a nonlinear finite element model to investigate the interface pressure between the above-knee residual limb and its prosthetic socket. The model was three-dimensional (3D) with consideration of nonlinear boundary conditions. Contact analysis was used to simulate the friction conditions between skin and the socket. The normal stresses up to 80.57 kPa at the distal end of the soft tissue. The longitudinal and circumferential shear stress distributions at the limb-socket interface were also simulated. This study explores the influences of load transfer between trans-femoral residual limb and its prosthetic socket.

  15. Transfemoral sockets with vacuum-assisted suspension comparison of hip kinematics, socket position, contact pressure, and preference: ischial containment versus brimless.

    Science.gov (United States)

    Kahle, Jason T; Highsmith, M Jason

    2013-01-01

    The objective of this study was to investigate the effect of brimless compared with ischial ramus containment (IRC) prosthetic sockets when using vacuum-assisted suspension (VAS) on persons with a unilateral transfemoral amputation (TFA). A randomized crossover design with a 2 d accommodation was used. People with unilateral TFA (n = 9 analyzed) were enrolled. Interventions were IRC VAS and brimless VAS sockets. Main outcome measures included coronal hip angle and vertical and lateral socket movement as measured by X-ray, skin pressure measured by Tekscan, and preference measured subjectively. The brimless design was statistically equivalent to IRC in all measured coronal hip angles and vertical and lateral socket displacement. The peak/stance mean pressure in the medial proximal aspect of the socket was 322 mmHg in the IRC compared with 190 mmHg in the brimless condition. Except for medial proximal pressure, no other measures reached statistical significance. All subjects reported the brimless design to be more comfortable than the IRC in short-term preference. Brimless VAS socket design may be a clinically viable choice for people with TFA.

  16. Transfemoral sockets with vacuum-assisted suspension comparison of hip kinematics, socket position, contact pressure, and preference: Ischial containment versus brimless

    Directory of Open Access Journals (Sweden)

    Jason T. Kahle, MSMS, CPO, FAAOP

    2013-12-01

    Full Text Available The objective of this study was to investigate the effect of brimless compared with ischial ramus containment (IRC prosthetic sockets when using vacuum-assisted suspension (VAS on persons with a unilateral transfemoral amputation (TFA. A randomized crossover design with a 2 d accommodation was used. People with unilateral TFA (n = 9 analyzed were enrolled. Interventions were IRC VAS and brimless VAS sockets. Main outcome measures included coronal hip angle and vertical and lateral socket movement as measured by X-ray, skin pressure measured by Tekscan, and preference measured subjectively. The brimless design was statistically equivalent to IRC in all measured coronal hip angles and vertical and lateral socket displacement. The peak/stance mean pressure in the medial proximal aspect of the socket was 322 mmHg in the IRC compared with 190 mmHg in the brimless condition. Except for medial proximal pressure, no other measures reached statistical significance. All subjects reported the brimless design to be more comfortable than the IRC in short-term preference. Brimless VAS socket design may be a clinically viable choice for people with TFA.

  17. 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.

  18. Effect of alignment changes on sagittal and coronal socket reaction moment interactions in transtibial prostheses.

    Science.gov (United States)

    Kobayashi, Toshiki; Orendurff, Michael S; Zhang, Ming; Boone, David A

    2013-04-26

    Alignment is important for comfortable and stable gait of lower-limb prosthesis users. The magnitude of socket reaction moments in the multiple planes acting simultaneously upon the residual limb may be related to perception of comfort in individuals using prostheses through socket interface pressures. The aim of this study was to investigate the effect of prosthetic alignment changes on sagittal and coronal socket reaction moment interactions (moment-moment curves) and to characterize the curves in 11 individuals with transtibial amputation using novel moment-moment interaction parameters measured by plotting sagittal socket reaction moments versus coronal ones under various alignment conditions. A custom instrumented prosthesis alignment component was used to measure socket reaction moments during walking. Prosthetic alignment was tuned to a nominally aligned condition by a prosthetist, and from this position, angular (3° and 6° of flexion, extension, abduction or adduction of the socket) and translational (5mm and 10mm of anterior, posterior, medial or lateral translation of the socket) alignment changes were performed in either the sagittal or the coronal plane in a randomized manner. A total of 17 alignment conditions were tested. Coronal angulation and translation alignment changes demonstrated similar consistent changes in the moment-moment curves. Sagittal alignment changes demonstrated more complex changes compared to the coronal alignment changes. Effect of sagittal angulations and translations on the moment-moment curves was different during 2nd rocker (mid-stance) with extension malalignment appearing to cause medio-lateral instability. Presentation of coronal and sagittal socket reaction moment interactions may provide useful visual information for prosthetists to understand the biomechanical effects of malalignment of transtibial prostheses.

  19. QUICK ASSESSMENT METHODOLOGY FOR RELIABILITY OF SOLDER JOINTS IN BALL GRID ARRAY (BGA) ASSEMBLY——PART Ⅰ: CREEP CONSTITUTIVE RELATION AND FATIGUE MODEL

    Institute of Scientific and Technical Information of China (English)

    史训清; 王志平; John HL Pang; 张学仁; 聂景旭

    2002-01-01

    In this study, a new unified creep constitutive relation and a modified energy-based fatigue model have been established respectively to describe the creep flow and predict the fatigue life of Sn-Pb solders. It is found that the relation successfully elucidates the creep mechanism related to current constitutive relations.The model can be used to describe the temperature and frequency dependent low cycle fatigue behavior of the solder. The relation and the model are further employed in part Ⅱ to develop the numerical simulation approach for the long-term reliability assessment of the plastic ball grid array (BGA) assembly.

  20. How does adding and removing liquid from socket bladders affect residual-limb fluid volume?

    Directory of Open Access Journals (Sweden)

    Joan E. Sanders, PhD

    2013-08-01

    Full Text Available Adding and removing liquid from socket bladders is a means for people with limb loss to accommodate residual-limb volume change. We fit 19 people with transtibial amputation using their regular prosthetic socket with fluid bladders on the inside socket surface to undergo cycles of bladder liquid addition and removal. In each cycle, subjects sat, stood, and walked for 90 s with bladder liquid added, and then sat, stood, and walked for 90 s again with the bladder liquid removed. The amount of bladder liquid added was increased in each cycle. We used bioimpedance analysis to measure residual-limb fluid volume. Results showed that the preferred bladder liquid volume was 16.8 +/– 8.4 mL (mean +/– standard deviation, corresponding with 1.7% +/– 0.8% of the average socket volume between the bioimpedance voltage-sensing electrodes. Residual-limb fluid volume driven out of the residual limb when bladder liquid was added was typically not recovered upon subsequent bladder liquid removal. Of the 19 subjects, 15 experienced a gradual residual-limb fluid volume loss over the test session. Care should be taken when implementing adjustable socket technologies in people with limb loss. Reducing socket volume may accentuate residual-limb fluid volume loss.

  1. How does adding and removing liquid from socket bladders affect residual-limb fluid volume?

    Science.gov (United States)

    Sanders, Joan E; Cagle, John C; Harrison, Daniel S; Myers, Timothy R; Allyn, Kathryn J

    2013-01-01

    Adding and removing liquid from socket bladders is a means for people with limb loss to accommodate residual-limb volume change. We fit 19 people with transtibial amputation using their regular prosthetic socket with fluid bladders on the inside socket surface to undergo cycles of bladder liquid addition and removal. In each cycle, subjects sat, stood, and walked for 90 s with bladder liquid added, and then sat, stood, and walked for 90 s again with the bladder liquid removed. The amount of bladder liquid added was increased in each cycle. We used bioimpedance analysis to measure residual-limb fluid volume. Results showed that the preferred bladder liquid volume was 16.8 +/- 8.4 mL (mean +/- standard deviation), corresponding with 1.7% +/- 0.8% of the average socket volume between the bioimpedance voltage-sensing electrodes. Residual-limb fluid volume driven out of the residual limb when bladder liquid was added was typically not recovered upon subsequent bladder liquid removal. Of the 19 subjects, 15 experienced a gradual residual-limb fluid volume loss over the test session. Care should be taken when implementing adjustable socket technologies in people with limb loss. Reducing socket volume may accentuate residual-limb fluid volume loss.

  2. Prosthetic Rehabilitation Following Socket Reconstruction with Blair-Brown Graft and Conformer Therapy for Management of Severe Post-Enucleation Socket Syndrome--A Clinical Report.

    Science.gov (United States)

    Aggarwal, Himanshi; Singh, Saumyendra V; Kumar, Pradeep; Kumar Singh, Arun

    2015-06-01

    One of the most common tumors of the eye diagnosed in childhood is retinoblastoma, which mandates enucleation with adjunctive chemotherapy and radiotherapy to save the patient's life. The most common late enucleation complication is post-enucleation socket syndrome (PESS), which poses a management dilemma for the prosthodontist and surgeon, along with being a major esthetic concern for the patient. The reconstruction of such sockets is complex. The purpose of this clinical report is to describe the rehabilitation of such a pediatric patient with severe PESS. The patient was successfully rehabilitated by presurgical conformer therapy, socket reconstruction surgery with non-meshed intermediate split thickness skin graft (STSG)/Blair-Brown graft, and postsurgical conformer stent. This was followed by fabrication of a custom ocular prosthesis, to achieve favorable functional, physical, and psychological effects.

  3. 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.

  4. Radio-ulnar joint supinates around ball release during baseball fastball pitching.

    Science.gov (United States)

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

    2016-06-01

    This study was conducted to determine whether a supination phase of the forearm exists around ball release (BRL), and, if present, to determine whether this supination is explained by a reaction force or by the body configuration required for this task. A 16-camera motion analysis system with a sampling frequency of 1,000 Hz recorded 20 healthy male semi-professional pitchers pitching from an indoor pitching mound. A short supination phase around BRL was confirmed for all participants in the current study. Correlation analyses revealed that the supination angle at BRL had significant relationships with several measurements of shoulder movement kinematics. Mechanical work analysis of the forearm's longitudinal axis revealed several variations in joint power curve and various patterns of mechanical work among the participants, suggesting that a reaction force originating from accelerating a ball might not be the main cause of supination. The raw data also were down-sampled to a sampling frequency of 250 Hz, to match previous studies and to investigate the discrepancy among previous studies concerning the existence of the supination phase. The experience of participants and methodological differences, such as the definition of BRL and the time-normalisation technique, influenced whether the supination phase was observed.

  5. 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

  6. Stabilizing transpelvic prosthetic socket for a patient with spinal cord injury sustaining right partial hemipelvectomy and left hip disarticulation.

    Science.gov (United States)

    Nakanishi, Yoshie; Watanabe, Tetsuro; Ikeda, Atsushi; Wada, Futoshi; Hachisuka, Kenji

    2012-06-01

    A bucket-type transpelvic socket was fabricated for a man with paraplegia from spinal cord injury, who underwent right partial pelvic amputation and left hip disarticulation. His main problem was inability to sit due to asymmetrical pelvic shape. We prescribed a transpelvic prosthetic socket to enable him to sit again. The socket consisted of a dual structure: a hard frame and soft liner. The main features of the socket were redistribution of pressure to prevent recurrence of pressure ulcer, and a slightly backward tilt to maintain a comfortable sitting position. In addition, the socket had small air holes for ventilation; a big window in the abdominal area for management of stoma and cystostomy; and two straps for donning it independently. In addition, we confirmed the internal pressure distribution in the socket by a pressure mapping system to prevent reoccurrence of skin trouble. Finally, the patient regained independence in activities of daily living, including driving a car, after two months of rehabilitative training.

  7. Dry socket

    Science.gov (United States)

    ... is a complication of having a tooth pulled ( tooth extraction ). The socket is the hole in the bone ... you: Have poor oral health Have a difficult tooth extraction Use birth control pills, which may interfere with ...

  8. 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.

  9. Study on Solder Joint Reliability of Plastic Ball Grid Array Component Based on SMT Products Virtual Assembly Technology

    Institute of Scientific and Technical Information of China (English)

    HUANG Chunyue; WU Zhaohua; ZHOU Dejian

    2006-01-01

    Based on surface mount products virtual assembly technology, the solder joint reliability of plastic ball grid array (PBGA) was studied. Four process parameters, including the upper pad diameter,the stencil thickness, the chip weight on a single solder joint and the lower pad diameter were chose as four control factors. By using an L25(56) orthogonal array the PBGA solder joints which have 25 different process parameters' levels combinations were designed. The numerical models of all the 25 PBGA solder joints were developed and the finite element analysis models were setup. The stress and strain distribution within the PBGA solder joints under thermal cycles were studied by finite element analysis, and the thermal fatigue life of PBGA solder joint was calculated using Coffin-Manson equation. Based on the calculated thermal fatigue life results, the range analysis was performed. The results of study show that that the impact sequence of the four factors from high to low on the fatigue life of PBGA solder joints are the stencil thickness,the upper pad diameter, the lower pad diameter and the chip weight on a single solder joint; the best level combination ofprocess parameters that results in the longest fatigue life is the lower pad diameter of 0.6 mm, the stencil thickness of 0.175 mm, the chip weight on asingle solder joint of 28×10-5 N and the upper pad diameter of 0.5 mm.

  10. 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.

  11. Recommendations on Composite Socket Fabrication Based Upon Experimental Results

    Science.gov (United States)

    2009-06-20

    Background 1 Socket Fabrication 1 Vacuum Assisted Resin Transfer Molding ( VARTM ) 3 Socket Manufacturing versus Traditional VARTM 4 Flat Panel Testing...Sockets are fabricated using techniques which are similar to Vacuum Assisted Resin Transfer Molding ( VARTM ). A discussion of socket fabrication...traditional VARTM processing, and the important differences between the two, will provide an important background. Socket Fabrication A positive mold is

  12. A pressure and shear sensor system for stress measurement at lower limb residuum/socket interface.

    Science.gov (United States)

    Laszczak, P; McGrath, M; Tang, J; Gao, J; Jiang, L; Bader, D L; Moser, D; Zahedi, S

    2016-07-01

    A sensor system for measurement of pressure and shear at the lower limb residuum/socket interface is described. The system comprises of a flexible sensor unit and a data acquisition unit with wireless data transmission capability. Static and dynamic performance of the sensor system was characterised using a mechanical test machine. The static calibration results suggest that the developed sensor system presents high linearity (linearity error ≤ 3.8%) and resolution (0.9 kPa for pressure and 0.2 kPa for shear). Dynamic characterisation of the sensor system shows hysteresis error of approximately 15% for pressure and 8% for shear. Subsequently, a pilot amputee walking test was conducted. Three sensors were placed at the residuum/socket interface of a knee disarticulation amputee and simultaneous measurements were obtained during pilot amputee walking test. The pressure and shear peak values as well as their temporal profiles are presented and discussed. In particular, peak pressure and shear of approximately 58 kPa and 27 kPa, respectively, were recorded. Their temporal profiles also provide dynamic coupling information at this critical residuum/socket interface. These preliminary amputee test results suggest strong potential of the developed sensor system for exploitation as an assistive technology to facilitate socket design, socket fit and effective monitoring of lower limb residuum health.

  13. Finite-element analysis to determine effect of monolimb flexibility on structural strength and interaction between residual limb and prosthetic socket.

    Science.gov (United States)

    Lee, Winson C C; Zhang, Ming; Boone, David A; Contoyannis, Bill

    2004-01-01

    Monolimb refers to a kind of transtibial prostheses having the socket and shank molded into one piece of thermoplastic material. One of its characteristics is that the shank is made of a material that can deform during walking, which can simulate ankle joint motion to some extent. Changes in shank geometry can alter the stress distribution within the monolimb and at the residual limb-socket interface and, respectively, affect the deformability and structural integrity of the prosthesis and comfort perceived by amputees. This paper describes the development of a finite-element model for the study of the structural behavior of monolimbs with different shank designs and the interaction between the limb and socket during walking. The von Mises stress distributions in monolimbs with different shank designs at different walking phases are reported. With the use of distortion energy theory, possible failure was predicted. The effect of the stiffness of the monolimb shanks on the stress distribution at the limb-socket interface was studied. The results show a trend--the peak stress applied to the limb was lowered as the shank stiffness decreased. This information is useful for future monolimb optimization.

  14. NCI and Leidos Play Ball | Poster

    Science.gov (United States)

    By Carolynne Keenan, Contributing Writer The ping of an aluminum bat off a ball or the thump of a pop-up fly ball caught in a glove are two sounds familiar to baseball fans. Slow-pitch softball sounds—like those in the August game between mixed teams of NCI and Leidos Biomedical Research (formerly SAIC-Frederick) players—are similar.

  15. 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.

  16. 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

    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...... 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...

  17. 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.

  18. 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.

  19. Effect of prosthetic gel liner thickness on gait biomechanics and pressure distribution within the transtibial socket

    Directory of Open Access Journals (Sweden)

    Erin Boutwell, MS

    2012-04-01

    Full Text Available Prosthetic gel liners are often prescribed for persons with lower-limb amputations to make the prosthetic socket more comfortable. However, their effects on residual limb pressures and gait characteristics have not been thoroughly explored. This study investigated the effects of gel liner thickness on peak socket pressures and gait patterns of persons with unilateral transtibial amputations. Pressure and quantitative gait data were acquired while subjects walked on liners of two different uniform thicknesses. Fibular head peak pressures were reduced (p = 0.04 with the thicker liner by an average of 26 +/– 21%, while the vertical ground reaction force (GRF loading peak increased 3 +/– 3% (p = 0.02. Most subjects perceived increased comfort within the prosthetic socket with the thicker liner, which may be associated with the reduced fibular head peak pressures. Additionally, while the thicker liner presumably increased comfort by providing a more compliant limb-socket interface, the higher compliance may have reduced force and vibration feedback to the residual limb and contributed to the larger vertical GRF loading peaks. We conclude that determining optimal gel liner thickness for a particular individual will require further investigations to better identify and understand the compromises that occur between user perception, residual-limb pressure distribution, and gait biomechanics.

  20. Effect of prosthetic gel liner thickness on gait biomechanics and pressure distribution within the transtibial socket.

    Science.gov (United States)

    Boutwell, Erin; Stine, Rebecca; Hansen, Andrew; Tucker, Kerice; Gard, Steven

    2012-01-01

    Prosthetic gel liners are often prescribed for persons with lower-limb amputations to make the prosthetic socket more comfortable. However, their effects on residual limb pressures and gait characteristics have not been thoroughly explored. This study investigated the effects of gel liner thickness on peak socket pressures and gait patterns of persons with unilateral transtibial amputations. Pressure and quantitative gait data were acquired while subjects walked on liners of two different uniform thicknesses. Fibular head peak pressures were reduced (p = 0.04) with the thicker liner by an average of 26 +/- 21%, while the vertical ground reaction force (GRF) loading peak increased 3 +/- 3% (p = 0.02). Most subjects perceived increased comfort within the prosthetic socket with the thicker liner, which may be associated with the reduced fibular head peak pressures. Additionally, while the thicker liner presumably increased comfort by providing a more compliant limb-socket interface, the higher compliance may have reduced force and vibration feedback to the residual limb and contributed to the larger vertical GRF loading peaks. We conclude that determining optimal gel liner thickness for a particular individual will require further investigations to better identify and understand the compromises that occur between user perception, residual-limb pressure distribution, and gait biomechanics.

  1. A Comparison of C++ Sockets and Corba in a Distributed Matrix Multiply Application

    OpenAIRE

    Schnaidt, Matt; Duman, Alpay; Lewis, Ted

    1998-01-01

    This project has two primary purposes. The first, is to implement a distributed matrix multiply algorithm using C++ sockets, and Corba objects with the objective of discovering what additional overhead, if any, exists in a Corba implementation. Secondly, attempt to improve the speedup through the use of stateful servers in the C++ implementation.

  2. Deep flexion-oriented bisurface-type knee joint and its tibial rotation that attributes its high performance of flexion.

    Science.gov (United States)

    Ueo, Toyoji; Kihara, Yuuichi; Ikeda, Noboru; Kawai, Jun; Nakamura, Kenji; Hirokawa, Shunji

    2011-04-01

    In 1989, we developed an artificial knee prosthesis that could accommodate the oriental lifestyle where people would sit more often on the floor than on a chair. The knee had a bisurface feature with an auxiliary joint of a ball and socket at the center of the posterior part aiming at an improved flexional function. The auxiliary joint functions not only to facilitate a rollback movement but also to add a rotational movement. It was investigated whether this knee prosthesis could show an internal rotation of the tibia during flexion such as the physiologic movement of the knee. The internal rotation of the tibia was evaluated for the patients who could sit on legs in the oriental style after total knee arthroplasty. The average flexion angle of patients who achieved this style of sitting was 144.1°, and the average internal rotation was estimated as 14.3° by a pattern matching method using a computer-assisted design system.

  3. Laboratory and clinical tests of a prototype pressure sensor for clincial assessment of prosthetic socket fit.

    Science.gov (United States)

    Polliack, A A; Craig, D D; Sieh, R C; Landsberger, S; Mcneal, D R

    2002-04-01

    Lower limb prosthetic socket fabrication is a highly refined process relying on the prosthetist's skill and experience. Despite their best efforts, patients often return with complications. Additionally, clinical application of technological advances for the quantification of biomechanical factors at the socket interface has not changed in practice. Measuring pressure levels at the stump/socket interface could provide valuable information in the process of prosthetic socket fabrication, fit and modification. This paper presents findings on the performance of a prototype capacitance pressure sensor designed for prosthetic socket use. Bench tests using compressed air were performed to measure accuracy, hysteresis and drift responses in both a flatbed chamber and a custom-modified pressure vessel. For the contoured testing, the sensors were placed on nine sites on a positive trans-tibial stump mould and enveloped with a silicone liner. Additionally, a preliminary clinical evaluation was performed with two trans-tibial amputee subjects at the nine sites during normal ambulation. Bench test results showed that the prototype capacitance sensor performed well in all categories, exhibiting a 2.42% (flatbed) and 9.96% (contoured) accuracy error, a 12.93% (flatbed) and 12.95% (contoured) hysteresis error, and a 4.40% (flatbed) and 6.20% (contoured) drift error. The clinical study showed that after three hours of continual use, no noticeable sensor drift occurred between pre and post-test calibration values. The results from this study were encouraging and the authors hope to conduct further laboratory and clinical trials to assess the influence of shear force and dynamic loading on sensor response.

  4. Effect of alignment changes on socket reaction moments during gait in transfemoral and knee-disarticulation prostheses: case series.

    Science.gov (United States)

    Kobayashi, Toshiki; Orendurff, Michael S; Boone, David A

    2013-09-27

    The alignment of a lower-limb prosthesis is critical to the successful prosthetic fitting and utilization by the wearer. Loads generated by the socket applied to the residual limb while walking are thought to be different in transfemoral and knee-disarticulation prostheses. The aim of this case series was to compare the socket reaction moments between transfemoral and knee-disarticulation prostheses and to investigate the effect of alignment changes on them. Two amputees, one with a transfemoral prosthesis and another with a knee-disarticulation prosthesis, participated in this study. A Smart Pyramid™ was used to measure socket reaction moments while walking under 9 selected alignment conditions; including nominally aligned, angle malalignments of 6° (flexion, extension, abduction and adduction) and translation malalignments of 15 mm (anterior, posterior, medial and lateral) of the socket relative to the foot. This study found that the pattern of the socket reaction moments was similar between transfemoral and knee-disarticulation prostheses. An extension moment in the sagittal plane and a varus moment in the coronal plane were dominant during stance under the nominally aligned condition. This study also demonstrated that alignment changes might have consistent effects on the socket reaction moments in transfemoral and knee-disarticulation prostheses. Extension and posterior translation of the socket resulted in increases in an extension moment, while abduction and lateral translation of the socket resulted in increases in a varus moment. The socket reaction moments may potentially serve as useful biomechanical parameters to evaluate alignment in transfemoral and knee-disarticulation prostheses.

  5. A Combined Surgical and Prosthetic Approach for the Successful Management of a Mutilated Eye Socket: A case report.

    Science.gov (United States)

    Prithviraj, D R; Khare, Sumit; Gupta, Anish; Shruthi, D P

    2010-04-01

    Facial disfigurement through the loss of an eye due to a road traffic accident can be devastating for the patient and may leave few options for an ophthalmologist, especially if the situation demands urgency. In the present case report, the patient had a major accident, which resulted in the severe disruption of the socket. The requirements of the prosthodontist regarding the morphology of the socket guided the ophthalmologist to undertake reconstructive surgery. The prosthesis was then fabricated such that both its longevity and the morphology of the socket were safe guarded.

  6. 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).

  7. Evaluation of relative distribution and risk factors in patients with dry socket referring to Yazd dental clinics

    Directory of Open Access Journals (Sweden)

    Hasan Momeni

    2011-01-01

    Conclusion: The results of our study suggested that trauma during surgery or extraction and poor oral hygiene are important factors that increase the incidence of dry socket, these factors should be considered before and after tooth extractions.

  8. 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

    2014-01-01

    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

  9. Walking Ability and Quality of Life in Subjects With Transfemoral Amputation: A Comparison of Osseointegration With Socket Prostheses.

    NARCIS (Netherlands)

    Meent, H. van de; Hopman, M.T.E.; Frolke, J.P.M.

    2013-01-01

    OBJECTIVE: To investigate walking ability and quality of life of osseointegrated leg prostheses compared with socket prostheses. DESIGN: Prospective case-control study. SETTING: University medical center. PARTICIPANTS: Subjects (N=22) with transfemoral amputation (1 bilateral) referred to our center

  10. Effect of alignment changes on socket reaction moments during gait in transfemoral and knee-disarticulation prostheses: Case series

    OpenAIRE

    Kobayashi, Toshiki; Orendurff, Michael S.; Boone, David A.

    2013-01-01

    The alignment of a lower-limb prosthesis is critical to the successful prosthetic fitting and utilization by the wearer. Loads generated by the socket applied to the residual limb while walking are thought to be different in transfemoral and knee-disarticulation prostheses. The aim of this case series was to compare the socket reaction moments between transfemoral and knee-disarticulation prostheses and to investigate the effect of alignment changes on them. Two amputees, one with a transfemo...

  11. Algorithm on robot soccer pass and shoot a ball

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Introduces of robot soccer's competition software of Harbin Institute of Technology(HIT), the con cept of running range and the method of calculating the running range for both the opponent and our teammates according to the distances Between the ball and robot soccers, and therefore the method of calculating the angle that the robot passes or shoots the ball according to the running ranges of both sides. And gives the examples of passing the ball when the ball's position is in the backcourt and shooting the ball when the ball's position is in the frontcourt.

  12. Biased discrete symmetry breaking and Fermi balls

    CERN Document Server

    MacPherson, A L; Macpherson, Alick L; Campbell, Bruce A

    1994-01-01

    The spontaneous breaking of an approximate discrete symmetry is considered, with the resulting protodomains of true and false vacuum being separated by domain walls. Given a strong, symmetric Yukawa coupling of the real scalar field to a generic fermion, the domain walls accumulate a gas of fermions, which modify the domain wall dynamics. The splitting of the degeneracy of the ground states results in the false vacuum protodomain structures eventually being fragmented into tiny false vacuum bags with a Fermi gas shell (Fermi balls), that may be cosmologically stable due to the Fermi gas pressure and wall curvature forces, acting on the domain walls. As fermions inhabiting the domain walls do not undergo number density freeze out, stable Fermi balls exist only if a fermion anti-fermion asymmetry occurs. Fermi balls formed with a new Dirac fermion that possesses no standard model gauge charges provide a novel cold dark matter candidate.

  13. Ball machine usage in tennis: movement initiation and swing timing while returning balls from a ball machine and from a real server.

    Science.gov (United States)

    Carboch, Jan; Süss, Vladimir; Kocib, Tomas

    2014-05-01

    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. Key pointsPlayers have shorter initial move time when they are facing the ball machine.Using the ball machine results in different swing timing and movement coordination.The use of the ball machine should be limited.

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

    Science.gov (United States)

    Carboch, Jan; Süss, Vladimir; Kocib, Tomas

    2014-01-01

    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. Key points Players have shorter initial move time when they are facing the ball machine. Using the ball machine results in different swing timing and movement coordination. The use of the ball machine should be limited. PMID:24790483

  15. Application of sealing socket joint of medium-temperature pitch in 6m coke oven battery%中温沥青密封承插口在6m 焦炉的应用

    Institute of Scientific and Technical Information of China (English)

    邵仪先

    2014-01-01

    This paper introduced a new technology for socket joint of ascension pipe by sealing with medium-temperature pitch,which has successfully been used for four 6m coke oven batteries in terms of improving operating environment and a remarkable economic benefit by 330,000 RMB yuan all year around.%介绍了上升管承插口采用中温沥青密封处理的新方法,已成功应用于4座6m 焦炉,全年效益可达33万元,改善了作业环境,经济环保效益显著。

  16. Reverse engineering and rapid prototyping techniques to innovate prosthesis socket design

    Science.gov (United States)

    Colombo, Giorgio; Bertetti, Massimiliano; Bonacini, Daniele; Magrassi, Grazia

    2006-02-01

    The paper presents an innovative approach totally based on digital data to optimize lower limb socket prosthesis design. This approach is based on a stump's detailed geometric model and provides a substitute to plaster cast obtained through the traditional manual methodology with a physical model, realized with Rapid Prototyping technologies; this physical model will be used for the socket lamination. The paper discusses a methodology to reconstruct a 3D geometric model of the stump able to describe with high accuracy and detail the complete structure subdivided into bones, soft tissues, muscular masses and dermis. Some different technologies are used for stump acquisition: non contact laser technique for external geometry, CT and MRI imaging technologies for the internal structure, the first one dedicated to bones geometrical model, the last for soft tissues and muscles. We discuss problems related to 3D geometric reconstruction: the patient and stump positioning for the different acquisitions, markers' definition on the stump to identify landmarks, alignment's strategies for the different digital models, in order to define a protocol procedure with a requested accuracy for socket's realization. Some case-studies illustrate the methodology and the results obtained.

  17. Network Programming tcp/ip protocol and socket discussion%网络编程tcp/ip协议与socket论述

    Institute of Scientific and Technical Information of China (English)

    严谦; 阳泳

    2016-01-01

    随着互联网技术的不断发展,网络通信成为当前互联网技术的重要技术,所以当前网络编程技术成为当前互联网通信发展的核心技术。网络编程主要是的通过使用套接字来实现进程间的编程,在Windows系统中的网络编程的套接字winscok,而在linux系统中最常见的套接字就是socket,本文就linux网络编程中的tcp、ip协议以及socket套接字问题进行详细的论述。%With the continuous development of Internet technology, network communications become an important technology of Internet technology, so the current network programming technology as the core technology of the current development of Internet communications. Network programming primarily achieved through the use of socket programming between processes in Windows system network programming socket winscok, while in linux system is the most common socket socket, paper linux Network Programming the tcp, ip protocol and socket socket issues are discussed in detail.

  18. Reasonable Ball Size of Ball Mill for Preparing Coal Water Fuel and Forecasting Productive Capacity

    Institute of Scientific and Technical Information of China (English)

    张荣曾; 刘炯天; 徐志强; 郑明

    2002-01-01

    By using the matrix theory, a 5-parameter grinding mathema tical model is established. Based on the properties of feed coal and requirement s for size distribution of final product, the model gives the required grinding probability for various particles and corresponding ball size distribution. By u sing this model, 3 different sizes of ball mill are designed and put into commer cial use for coal water fuel. The forecasted ball mill capacity, the particle si zes and particle size distribution as well as the coal water fuel quality parame ters are all in line with industrial operation results, which have proved the su itability of the model.

  19. Frictional torque numbers for ball cup and journal bearings

    NARCIS (Netherlands)

    Ligterink, D.J.

    1982-01-01

    Plastic bearing material wears in ball cup and journal bearings. Contact areas in the ball cup and the journal bearing increase. The frictional torque needed to rotate the ball or journal also increases. When the coefficient of friction is assumed to be constant during wearing out, the frictional t

  20. Frictional torque numbers for ball cup and journal bearings

    OpenAIRE

    Ligterink, D.J.

    1982-01-01

    Plastic bearing material wears in ball cup and journal bearings. Contact areas in the ball cup and the journal bearing increase. The frictional torque needed to rotate the ball or journal also increases. When the coefficient of friction is assumed to be constant during wearing out, the frictional torque increases to a maximum of 1.273 times the frictional torque at zero wear.

  1. 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.

  2. 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.

  3. Lawn tennis balls, Rolling friction experiment and Trouton viscosity

    CERN Document Server

    Singh, Ankit; Kulkarni, Kaustubh; Budhraja, Abhishek; Tej, K R Sai; Sankarlingam, Satish; Biswas, Anindya Kumar

    2008-01-01

    Three lawn tennis balls were arbitrarily taken. One ball was new, one was moderately old and another was old. We have fabricated a conveyor belt set-up and measured rolling friction coefficients, $\\mu_{r}$, of the three balls as a function of their angular velocities, $\\omega$. For the new ball, quadratic fit is perfect. For the moderately old ball, linear fit is accurate. In all the three cases, from linear fits, we obtain $k_{rol}$, where, $\\mu_{r}= k_{rol} \\omega + intercept$. We deduce $k_{rol}$ theoretically also, assuming Trouton ratio as three. The experimental results and theoretical estimates are of the same order of magnitude.

  4. A three-dimensional finite element model of the transibial residual limb and prosthetic socket to predict skin temperatures.

    Science.gov (United States)

    Peery, Jeffrey T; Klute, Glenn K; Blevins, Joanna J; Ledoux, William R

    2006-09-01

    Amputees who wear prosthetic limbs often experience discomfort from blisters and sores due to mechanical insult; these skin conditions are exacerbated by elevated skin temperatures and excessive perspiration within the prosthetic socket. The goal of this study was to create a tool for developing new prostheses that accommodate varying thermal loads arising from everyday activities. A three-dimensional thermal model of a transtibial residual limb and prosthesis was constructed using the finite element (FE) method. Transverse computerized tomography (CT) scans were used to specify the geometry of the residual limb and socket. Thermal properties from the literature were assigned to both biological tissue and prosthetic socket elements. The purpose of this work was to create a model that would aid in testing the effect of new prosthesis designs on skin temperature. To validate its output, the model was used to predict the skin temperature distribution in a common prosthetic socket system (silicone liner, wool sock, and carbon fiber socket) at rest with no mechanical loading. Skin temperatures were generally elevated near muscle and decreased anteriorly and at the distal end. Experimental temperature measurements taken at the skin-prosthesis interface of five human subjects were used to validate the model. Data extracted from the thermal model at anterior, posterior, lateral, and medial locations were typically within one standard deviation of experimental results; the mean temperatures were within 0.3 degree C for each section and were within 0.1 degree C overall.

  5. Dust ball physics and the Schwarzschild metric

    CERN Document Server

    Kassner, Klaus

    2016-01-01

    A physics-first derivation of the Schwarzschild metric is given. Gravitation is described in terms of the effects of tidal forces (or of spacetime curvature) on the volume of a small ball of test particles (a dust ball), freely falling after all particles were at rest with respect to each other initially. The possibility to express Einstein's equation this way and some of its ramifications have been enjoyably discussed by Baez and Bunn [Am. J. Phys. 73, 644 (2005)]. Since the formulation avoids the use of tensors, neither advanced tensor calculus nor sophisticated differential geometry are needed in the calculation. The derivation is not lengthy and it has visual appeal, so it may be useful in teaching.

  6. Capillary floating and the billiard ball problem

    OpenAIRE

    Gutkin, Eugene

    2010-01-01

    We establish a connection between capillary floating in neutral equilibrium and the billiard ball problem. This allows us to reduce the question of floating in neutral equilibrium at any orientation with a prescribed contact angle for infinite homogeneous cylinders to a question about billiard caustics for their orthogonal cross-sections. We solve the billiard problem. As an application, we characterize the possible contact angles and exhibit an infinite family of real analytic non-round cyli...

  7. 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.

  8. Collisional and collisionless expansion of Yukawa balls.

    Science.gov (United States)

    Piel, Alexander; Goree, John A

    2013-12-01

    The expansion of Yukawa balls is studied by means of molecular dynamics simulations of collisionless and collisional situations. High computation speed was achieved by using the parallel computing power of graphics processing units. When the radius of the Yukawa ball is large compared to the shielding length, the expansion process starts with the blow-off of the outermost layer. A rarefactive wave subsequently propagates radially inward at the speed of longitudinal phonons. This mechanism is fundamentally different from Coulomb explosions, which employ a self-similar expansion of the entire system. In the collisionless limit, the outer layers carry away most of the available energy. The simulations are compared with analytical estimates. In the collisional case, the expansion process can be described by a nonlinear diffusion equation that is a special case of the porous medium equation.

  9. Effect of Therapy Ball Seating on Learning and Sitting Discomforts among Saudi Female Students

    Directory of Open Access Journals (Sweden)

    Einas Al-Eisa

    2013-01-01

    Full Text Available The aim of the study was to evaluate the effect of therapy ball seating as an alternative for typical chair seating in a classroom. We evaluated the effect of ball seating on the student's sitting discomfort and academic performance using Cornell Musculoskeletal Discomfort Questionnaire and problem-based learning scales, respectively. A sample of convenience was taken. Data was collected and analyzed using t-test. Subjects experienced a major discomfort at neck and a minor discomfort at knee joint. Results showed that there was a significant improvement (P≤0.05 in sitting discomfort and student's performance when seated on therapy balls compared to typical classroom chairs. This study provides evidence for the effectiveness of therapy balls as a classroom seating for students who exhibit sitting discomfort and problem-based learning.

  10. Perceptual elements in Penn & Teller's "Cups and Balls" magic trick.

    Science.gov (United States)

    Rieiro, Hector; Martinez-Conde, Susana; Macknik, Stephen L

    2013-01-01

    Magic illusions provide the perceptual and cognitive scientist with a toolbox of experimental manipulations and testable hypotheses about the building blocks of conscious experience. Here we studied several sleight-of-hand manipulations in the performance of the classic "Cups and Balls" magic trick (where balls appear and disappear inside upside-down opaque cups). We examined a version inspired by the entertainment duo Penn & Teller, conducted with three opaque and subsequently with three transparent cups. Magician Teller used his right hand to load (i.e. introduce surreptitiously) a small ball inside each of two upside-down cups, one at a time, while using his left hand to remove a different ball from the upside-down bottom of the cup. The sleight at the third cup involved one of six manipulations: (a) standard maneuver, (b) standard maneuver without a third ball, (c) ball placed on the table, (d) ball lifted, (e) ball dropped to the floor, and (f) ball stuck to the cup. Seven subjects watched the videos of the performances while reporting, via button press, whenever balls were removed from the cups/table (button "1") or placed inside the cups/on the table (button "2"). Subjects' perception was more accurate with transparent than with opaque cups. Perceptual performance was worse for the conditions where the ball was placed on the table, or stuck to the cup, than for the standard maneuver. The condition in which the ball was lifted displaced the subjects' gaze position the most, whereas the condition in which there was no ball caused the smallest gaze displacement. Training improved the subjects' perceptual performance. Occlusion of the magician's face did not affect the subjects' perception, suggesting that gaze misdirection does not play a strong role in the Cups and Balls illusion. Our results have implications for how to optimize the performance of this classic magic trick, and for the types of hand and object motion that maximize magic misdirection.

  11. Development and Evaluation of Secure Socket Layer Visualization Tool with Packet Capturing Function

    Directory of Open Access Journals (Sweden)

    Arai Masayuki

    2015-01-01

    Full Text Available Secure Socket Layer (SSL has become a fundamental technology that secures browser-processed personal details sent to the server. As a result, communication and computer engineers are advised to learn the protocol. However, understanding SSL is very difficult because of its intricate communication procedure. To solve this problem, we developed a visualization tool for understanding SSL. This paper describes the design, implementation methods, and evaluation of the tool. The evaluation results show that the visualization tool is effective for learning SSL.

  12. 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

  13. 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.

  14. 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.

  15. 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.

  16. Mechanism and Impedance Control of the Ball Universal Joint Robot Driven by the Pneumatic Muscle Actuator Group%基于气动肌肉群驱动球关节机器人结构及阻抗控制

    Institute of Scientific and Technical Information of China (English)

    刘昱; 王涛; 范伟

    2013-01-01

    气动肌肉(Pneumatic muscle actuator,PMA)是仿生机器人研究的重点,为此,设计一种由气动肌肉群驱动的3自由度球关节机器人,并对其进行运动学分析.根据其运动学逆解,提出气动肌肉群位置控制策略;同时,提出基于运动学逆解及能量最优原则气动肌肉群力控制策略;设计基于气动肌肉位置群及力群的含位置PID内环的阻抗控制器.试验结果表明,单纯的位置控制精度比较高,可达0.3°,但造成输出力矩失控;阻抗控制虽然在一定程度上牺牲了位置控制精度,但可以对输出力矩进行柔顺控制.%Pneumatic muscle actuator (PMA) is the research focus of bionic robot.Therefore,a triaxial-ball universal joint robot driven by the PMA group is designed.The kinematics of the robot is analysed.On the basis of its kinematics analysis,the position control strategy of the PMA group is proposed.Based on the kinematics analysis and the energy saving principle,the contact force control strategy of the PMA group is proposed.An impedance control scheme with inner position PID loop is designed for the PMA group.Results show that under position control only,the control accuracy is higher than impedance control and the steady-error is less than 0.3°,however,the contact force is out of control.Impedance control sacrifices a certain degree of position control accuracy but can realize compliant control of contact force.

  17. Bouncing Balls and Graphing Derivatives

    Science.gov (United States)

    Cory, Beth

    2010-01-01

    National Council of Teachers of Mathematics' (NCTM's) (2000) Connections Standard states that students should "recognize and use connections among mathematical ideas; understand how mathematical ideas interconnect ...; [and] recognize and apply mathematics in contexts outside of mathematics" (p. 354). This article presents an in-depth…

  18. 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

  19. Capillary floating and the billiard ball problem

    CERN Document Server

    Gutkin, Eugene

    2010-01-01

    We establish a connection between capillary floating in neutral equilibrium and the billiard ball problem. This allows us to reduce the question of floating in neutral equilibrium at any orientation with a prescribed contact angle for infinite homogeneous cylinders to a question about billiard caustics for their orthogonal cross-sections. We solve the billiard problem. As an application, we characterize the possible contact angles and exhibit an infinite family of real analytic non-round cylinders that float in neutral equilibrium at any orientation with constant contact angles.

  20. Multisensory perception and action in 3-ball cascade juggling

    OpenAIRE

    Sánchez García, Raúl; Hayes, S J; Williams, A M; Bennett, S. J.

    2013-01-01

    Multisensory perception and action in 3-ball cascade juggling was investigated in intermediate-skilled performers by manipulating vision (full or lower field restricted) or ball weight (equal or different). There were main effects for both independent variables but no interactions. Manipulation of ball weight had a more pervasive effect on performance outcome, as well as central tendency and dispersion of kinematic measures of the juggling action. A common finding to both manipulations was th...

  1. 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.

  2. Interpolating sliding mode observer for a ball and beam system

    Science.gov (United States)

    Luai Hammadih, Mohammad; Hosani, Khalifa Al; Boiko, Igor

    2016-09-01

    A principle of interpolating sliding mode observer is introduced in this paper. The observer incorporates multiple linear observers through interpolation of multiple estimates, which is treated as a type of adaptation. The principle is then applied to the ball and beam system for observation of the slope of the beam from the measurement of the ball position. The linearised model of the ball and beam system using multiple linearisation points is developed. The observer dynamics implemented in Matlab/Simulink Real Time Workshop environment. Experiments conducted on the ball and beam experimental setup demonstrate excellent performance of the designed novel interpolating (adaptive) observer.

  3. 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.

  4. Relative locality and the soccer ball problem

    CERN Document Server

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

    2011-01-01

    We consider the behavior of macroscopic bodies within the framework of relative locality, which is a recent proposal for Planck scale modifications of the relativistic dynamics of particles which are described as arising from deformations in the geometry of momentum space. These lead to the addition of non-linear terms to the energy-momentum relations and conservation laws, which are suppressed by powers of ratio between the energy E of the particles involved and the Planck mass M_P. We consider and resolve a common objection against such proposals, which is that, even if the corrections are small for elementary particles in current experiments, they are huge when applied to composite systems such as soccer balls, planets and stars, with energies E_{macro} much larger than M_P. We show that this "soccer-ball problem" does not arise within the framework of relative locality, because the non-linear effects for the dynamics of a composite system with N elementary particles appear at most of order E_{macro}/ N M_...

  5. Effects of caffeic acid phenethyl ester on palatal mucosal defects and tooth extraction sockets

    Directory of Open Access Journals (Sweden)

    Günay A

    2014-10-01

    Full Text Available Ahmet Günay,1 Osman Fatih Arpağ,2 Serhat Atilgan,3 Ferhan Yaman,3 Yusuf Atalay,4 İzzet Acikan3 1Department of Periodontology, Faculty of Dentistry, Dicle University, Diyarbakir, Turkey; 2Department of Periodontology, Faculty of Dentistry, Mustafa Kemal University, Hatay, Turkey; 3Department of Maxillofacial Surgery, Faculty of Dentistry, Dicle University, Diyarbakir, Turkey; 4Department of Maxillofacial Surgery, Faculty of Dentistry, Kocatepe University, Afyon, Turkey Aim: The purpose of this study was to evaluate the effects of caffeic acid phenethyl ester (CAPE on palatal mucosal defects and tooth extraction sockets in an experimental model.Materials and methods: Forty-two male Sprague-Dawley rats with a mean age of 7 weeks and weighing 280–490 g were used in this study. The rats were randomly divided into two groups: group A (the control group, n=21 and group B (the experimental group, n=21. Under anesthesia with ketamine (8 mg/100 g, intraperitoneally, palatal mucosal defects were created and tooth extraction was performed in the rats in groups A and B. Group A received no treatment, whereas group B received CAPE. CAPE was injected daily (10 µmol/kg, intraperitoneally. The rats were killed on days 7, 14, and 30 after the procedures. Palatal mucosa healing and changes in bone tissue and fibrous tissue were evaluated histopathologically.Result: Pairwise comparisons showed no statistically significant difference between days 7 and 14 in either group (P>0.05. At day 30, bone healing was significantly better in group B (CAPE than in group A (control (P<0.05. Fibrinogen levels at day 30 were significantly higher in group A (control than in group B (CAPE (P<0.05. Pairwise comparisons showed no statistically significant difference in palatal mucosa healing levels between days 7 and 14 in both groups (P>0.05.Conclusion: In conclusion, the findings of this study suggest that CAPE can significantly improve tooth socket healing. Keywords: caffeic

  6. 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.

  7. 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.

  8. A novel prosthetic device and method for guided tissue preservation of immediate postextraction socket implants.

    Science.gov (United States)

    Chu, Stephen J; Hochman, Mark N; Tan-Chu, Jocelyn Hui-Ping; Mieleszko, Adam J; Tarnow, Dennis P

    2014-01-01

    Preservation of the surrounding hard and soft tissues associated with an immediate postextraction socket implant to replace a nonrestorable tooth in the esthetic zone is one of the greatest challenges facing the dental team. Several studies have documented the biologic and esthetic benefits of bone graft containment with either a custom healing abutment or provisional restoration. Use of a prefabricated shell that replicates the extracted tooth at the cervical region can help achieve guided tissue preservation and sustainable esthetic outcomes in an easy, simple, consistent, and less time consuming way. The following case report of a hopeless maxillary right central incisor in a female patient possessing adjacent teeth with a thin periodontal phenotype illustrates this new treatment device, method, and concept.

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

    Science.gov (United States)

    Nishida, Erika; Miyaji, Hirofumi; Kato, Akihito; Takita, Hiroko; Iwanaga, Toshihiko; Momose, Takehito; Ogawa, Kosuke; Murakami, Shusuke; Sugaya, Tsutomu; Kawanami, Masamitsu

    2016-01-01

    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 µg/mL GO scaffold were, respectively, approximately 2.5-fold and 1.4-fold greater than those of the control. Particularly, the infiltration of ED2-positive (M2) macrophages and blood vessels were prominent in the GO scaffold. Dog bone-formation tests showed that 1 µg/mL GO scaffold implantation enhanced bone formation. New bone formation following GO scaffold implantation was enhanced fivefold compared to that in control subjects. These results suggest that GO was biocompatible and had high bone-formation capability for the scaffold

  10. Segmented ball valve is easy to open and close

    Science.gov (United States)

    Prono, E.; Shinault, L. H.; Speisman, C.

    1966-01-01

    Segmented ball valve and flowmeter in the same spherical housing provide a valve that will handle large fluid volume without bulkiness and weight of blade valves or conventional ball valves. The valve is easily opened or closed and the flowmeter remains stationary, so errors are eliminated.

  11. 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 millim

  12. 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.)

  13. 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.

  14. Hot balls splash and sink fast

    Science.gov (United States)

    Marston, Jeremy; Vakarelski, Ivan; Thoroddsen, Sigurdur; Chan, Derek

    2011-11-01

    When a heated sphere is immersed in a liquid, we induce an inverted Leidenfrost effect whereby the sphere is wrapped in a vapour jacket which protects it from physical contact with the liquid and, when released to fall freely in the liquid, the sphere's terminal velocity can increase dramatically compared to a cold ball. This Leidenfrost-induced vapour layer can lead to significant drag reduction by up to 85% which appears to be the limiting case for drag reduction techniques based on gas layer injection. In a related experiment, when the heated sphere is released from above the surface, the dynamics of the entry are significantly different from the cold case, resulting in a prompt splash and cavity formation. We propose that this experiment is the ultimate non-wetting scenario during water-entry problems.

  15. Accuracy and Reliability of a New Tennis Ball Machine

    Directory of Open Access Journals (Sweden)

    Cyril Brechbuhl, Grégoire Millet, Laurent Schmitt

    2016-06-01

    Full Text Available 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. Conclusion: both the accuracy and the reliability of this new ball machine appear satisfying enough for field testing and training.

  16. 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.

  17. Ball clay

    Science.gov (United States)

    Virta, R.L.

    2011-01-01

    The article discusses the latest developments in the global ball clay mining industry, particularly in the U.S., as of June 2011. It cites several firms that are involved in ball clay mining in the U.S., including HC Spins Clay Co. Inc., the Imerys Group and Old Hickory Clay Co. Among the products made from ball clay are ceramic tiles, sanitaryware, as well as fillers, extenders and binders.

  18. 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

  19. Coronal plane socket stability during gait in persons with transfemoral amputation: Pilot study

    OpenAIRE

    Stefania Fatone, PhD, BPO(Hons); Michael Dillon, PhD; Rebecca Stine, MS; Robert Tillges, CP

    2015-01-01

    Little research describes which transfemoral socket design features are important for coronal plane stability, socket comfort, and gait. Our study objectives were to (1) relate socket comfort during gait to a rank order of changes in ischial containment (IC) and tissue loading and (2) compare socket comfort during gait when tissue loading and IC were systematically manipulated. Six randomly assigned socket conditions (IC and tissue compression) were assessed: (1) IC and high, (2) IC and mediu...

  20. 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.

  1. 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

  2. Socket preservation using bovine bone mineral and collagen membrane: a randomized controlled clinical trial with histologic analysis.

    Science.gov (United States)

    Cardaropoli, Daniele; Tamagnone, Lorenzo; Roffredo, Alessandro; Gaveglio, Lorena; Cardaropoli, Giuseppe

    2012-08-01

    After tooth extraction, varying amounts of bone resorption occur because of qualitative and quantitative changes at the edentulous site of the alveolar process. The aims of this randomized controlled clinical trial were (1) to compare the postextraction changes in residual ridge dimensions during spontaneous healing with those during socket preservation, (2) to analyze the histologic and histomorphometric aspects of the grafted sockets, and (3) to compare probing procket depth (PPD) and clinical attachment level (CAL) changes at teeth adjacent to extraction sites. Forty-eight teeth were extracted from 41 patients referred for extraction of 1 or more maxillary or mandibular premolars or molars. The edentulous sites were randomly assigned to the control (EXT, extraction alone) or experimental groups (SP, extraction and socket preservation). In the SP group, the sockets were filled with bovine bone mineral and covered with porcine collagen membrane. At baseline and after 4 months, PPD, gingival recession (REC), and CAL were measured at teeth adjacent to the edentulous sites. The changes in ridge dimensions from baseline to 4 months were assessed on dental casts. At 4 months, bone was harvested from the grafted areas in the SP group and the edentulous areas in the EXT group. PPD, REC, and CAL were comparable between groups. However, from baseline to 4 months, the SP group showed significantly less reduction in ridge width (1.04 ± 1.08 mm vs 4.48 ± 0.65 mm, P collagen membrane considerably limits the amount of horizontal and vertical bone resorption when compared with extraction alone.

  3. Effect of Beta-Blockers on Number of Osteoblasts and Osteoclasts in Alveolar Socket Following Tooth Extraction in Wistar Rats

    Science.gov (United States)

    Sadr, Katayoun; Aghbali, Amirala; Sadr, Makan; Abachizadeh, Hamed; Azizi, Maryam; Mesgari Abbasi, Mehran

    2017-01-01

    Statement of the Problem: Various researchers have suggested the use of β2-adrenergic receptor antagonists in prevention or treatment of bone resorption. Purpose: This study aimed to evaluate the effect of β2-adrenergic receptor antagonists on number of osteoclasts and osteoblasts involved in the healing of extraction socket of maxillary first molar in rats. Materials and Method: Maxillary first molars of 40 rats were extracted and divided into two groups. The test group received 0.1 mg/kg propranolol intraperitoneally daily. The controls received normal saline. At days 7, 14, 21 and 28 post-extraction, 5 rats were euthanized from each group. Maxillary bone was resected and the mean number of osteoblasts and osteoclasts in tooth socket was measured. Results: After 1 week, the number of osteoclasts in the controls was significantly higher than the test group. A significant increase in the number of osteoclasts in both groups at week 1 was observed compared to the following weeks (p< 0.05). The number of osteoblasts in the controls at second week reached its maximum rate but stayed constant in the 3rd and 4th weeks. Osteoblasts in the test group increased similar to the controls but reached its maximum at 3rd week and showed a significant increase compared to the controls (p< 0.05). Conclusion: β2 adrenergic receptor antagonists decrease the number of osteoclasts and increase the number of osteoblasts during extraction socket healing. PMID:28280758

  4. Effect of Beta-Blockers on Number of Osteoblasts and Osteoclasts in Alveolar Socket Following Tooth Extraction in Wistar Rats

    Directory of Open Access Journals (Sweden)

    Katayoun Sadr

    2017-03-01

    Full Text Available Statement of the Problem: Various researchers have suggested the use of β2-adrenergic receptor antagonists in prevention or treatment of bone resorption. Purpose: This study aimed to evaluate the effect of β2-adrenergic receptor antagonists on number of osteoclasts and osteoblasts involved in the healing of extraction socket of maxillary first molar in rats. Materials and Method: Maxillary first molars of 40 rats were extracted and divided into two groups. The test group received 0.1 mg/kg propranolol intraperitoneally daily. The controls received normal saline. At days 7, 14, 21 and 28 post-extraction, 5 rats were euthanized from each group. Maxillary bone was resected and the mean number of osteoblasts and osteoclasts in tooth socket was measured. Results: After 1 week, the number of osteoclasts in the controls was significantly higher than the test group. A significant increase in the number of osteoclasts in both groups at week 1 was observed compared to the following weeks (p< 0.05. The number of osteoblasts in the controls at second week reached its maximum rate but stayed constant in the 3rd and 4th weeks. Osteoblasts in the test group increased similar to the controls but reached its maximum at 3rd week and showed a significant increase compared to the controls (p< 0.05. Conclusion: β2 adrenergic receptor antagonists decrease the number of osteoclasts and increase the number of osteoblasts during extraction socket healing.

  5. A New Hybrid Network Sniffer Model Based on Pcap Language and Sockets (Pcapsocks

    Directory of Open Access Journals (Sweden)

    Azidine GUEZZAZ

    2016-02-01

    Full Text Available Nowadays, the protection and the security of data transited within computer networks represent a real challenge for developers of computer applications and network administrators. The Intrusion Detection System and Intrusion Prevention System are the reliable techniques for a Good security. Any detected intrusion is based on data collection. So, the collection of an important and significant traffic on the monitored systems is an interesting feature. Thus, the first task of Intrusion Detection System and Intrusion Prevention System is to collect information’s basis to treat and analyze them, and to make accurate decisions. Network analysis can be used to improve networks performances and their security, but it can also be used for malicious tasks. Our main goal in this article is to design a reliable and powerful network sniffer, called PcapSockS, based on pcap language and sockets, able to intercept traffic in three modes: connected, connectionless and raw mode. We start with the performances assessment performed on a list of most expanded and most recently used network sniffers. The study will be completed by a classification of these sniffers related to computer security objectives based on parameters library (libpcap/winpcap or libnet, filtering, availability, software or hardware, alert and real time. The PcapSockS provides a nice performance integrating reliable sniffing mechanisms that allow a supervision taking into account some low and high-level protocols for TCP and UDP network communications.

  6. Gender differences in the kinematics and ball velocity of overarm throwing in elite team handball players.

    Science.gov (United States)

    Van Den Tillaar, Roland; Cabri, Jan M H

    2012-01-01

    The aim of this study was to investigate the throwing velocity and kinematics of overarm throwing in team handball of elite female and male handball players. Kinematics and ball velocity of a 7 metre-throw in eleven elite male (age 23.6 ± 5.2 yr, body mass 87.0 ± 6.8 kg, height 1.85 ± 0.05 m) and eleven elite female (age 20.3 ± 1.8 yr, body mass 69.9 ± 5.5 kg, height 1.75 ± 0.05 m) team handball players were recorded. The analysis consisted of maximal joint angles, angles at ball release, maximal angular velocities of the joint movements, and maximal linear velocities of the distal endpoints of segments and their timing during the throw. The ball release velocity of the male handball players was significantly higher than the females (21.1 vs. 19.2 m · s(-1); p handball players throw with the same technique. It was concluded that differences in throwing velocity in elite male and female handball players are generally not the result of changes in kinematics in the joint movements.

  7. An Analysis and Implementation of a Parallel Ball Pivoting Algorithm

    Directory of Open Access Journals (Sweden)

    Julie Digne

    2014-07-01

    Full Text Available The problem of surface reconstruction from a set of 3D points given by their coordinates andoriented normals is a difficult problem, which has been tackled with many different approaches.In 1999, Bernardini and colleagues introduced a very elegant and efficient reconstruction methodthat uses a ball pivoting around triangle edges and adds new triangles if the ball is incidentto three points and contains no other points. This paper details an implementation and parallelization of this algorithm.

  8. An overview of Ball Aerospace cryogen storage and delivery systems

    Science.gov (United States)

    Marquardt, J.; Keller, J.; Mills, G.; Schmidt, J.

    2015-12-01

    Starting on the Gemini program in the 1960s, Beech Aircraft (now Ball Aerospace) has been designing and manufacturing dewars for a variety of cryogens including liquid hydrogen and oxygen. These dewars flew on the Apollo, Skylab and Space Shuttle spacecraft providing fuel cell reactants resulting in over 150 manned spaceflights. Since Space Shuttle, Ball has also built the liquid hydrogen fuel tanks for the Boeing Phantom Eye unmanned aerial vehicle. Returning back to its fuel cell days, Ball has designed, built and tested a volume-constrained liquid hydrogen and oxygen tank system for reactant delivery to fuel cells on unmanned undersea vehicles (UUVs). Herein past history of Ball technology is described. Testing has been completed on the UUV specific design, which will be described.

  9. Wear numbers for ball cup and journal bearings

    OpenAIRE

    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 millimetres, the wear modulus in newtons per square millimetre, the maximum wear depth rate of the cup or the cylindrical bearing in millimetres per second, the force between the mating surfaces in newto...

  10. Atmospheric Tar Balls: Particles from Biomass and Biofuel Burning

    Science.gov (United States)

    Posfai, Mihaly; Gelencser, Andras; Simonics, Renata; Arato, Krisztina; Li, Jia; Hobbs, Peter V.; Buseck, Peter R.

    2004-01-01

    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 (approximately 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.

  11. 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.

  12. Dynamic interface pressure distributions of two transtibial prosthetic socket concepts.

    Science.gov (United States)

    Dumbleton, Tim; Buis, Arjan W P; McFadyen, Angus; McHugh, Brendan F; McKay, Geoff; Murray, Kevin D; Sexton, Sandra

    2009-01-01

    In this study, we investigated and compared the dynamic interface pressure distribution of hands-off and hands-on transtibial prosthetic systems by means of pressure mapping. Of the 48 established unilateral amputees recruited, half (n = 24) had been wearing pressure-cast prostheses (IceCast Compact) and the other half (n = 24) had been wearing hand-cast sockets of the patellar tendon bearing design. We measured the dynamic pressure profile of more than 90% of the area within each prosthetic socket by means of four Tekscan F-Scan socket transducer arrays. We compared the interface pressure between socket concepts. We found that the distribution of dynamic pressure at the limb-socket interface was similar for the two intervention (socket prescription) groups. However, a significant difference was found in the magnitude of the interface pressure between the two socket concepts; the interface pressures recorded in the hands-off sockets were higher than those seen in the hands-on concept. Despite the differences in interface pressure, the level of satisfaction with the sockets was similar between subject groups. The sockets instrumented for this study had been in daily use for at least 6 months, with no residual-limb health problems.

  13. Effects of platelet-rich plasma on healing of alveolar socket: Split-mouth histological and histometric evaluation in Cebus apella monkeys

    Directory of Open Access Journals (Sweden)

    Pessoa Roberto

    2009-01-01

    Full Text Available Context: The prediction of implant treatment is directly influenced by the quality of the remaining bone after tooth extraction. Aims : The purpose of this experimental study was to, histologically and histometrically, evaluate the bone repair process in the central areas of extraction sockets filled with platelet-rich plasma. Materials and Methods: Four young adult male Cebus apella monkeys were used. The extraction of both right and left inferior second premolars was accomplished. After extraction, in one of the extraction sockets, coagulum was maintained while in the other it was removed; the alveolus was dried with gauze compress and filled up with platelet concentrate. For PRP production, Sonnleitner′s protocol was followed. The specimens for histological and histometric assessment were obtained in 30, 90, 120 and 180 days intervals. Results: In 30 days new bone formation was intense in both experimental and control sockets and no significant differences were observed between the two groups. After 90 days of the extraction, while the control group showed signs of decrease in osteogenesis, in the experimental unit, the process of bone formation and fibroblast-like cell proliferation remained intense. After 120 days, the PRP treated socket was occupied by large trabeculae of bone. After 180 days, the control unit was occupied mostly with bone marrow. The experimental unit remained occupied with large amounts of bone tissue. Conclusions: It was possible to conclude that bone repair was enhanced by the use of platelet- rich plasma in alveolar sockets.

  14. 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 init

  15. Design of a novel prosthetic socket: assessment of the thermal performance.

    Science.gov (United States)

    Webber, Christina M; Davis, Brian L

    2015-05-01

    Prosthetic liners and sockets insulate the residual limb, causing excessive sweating and concomitant skin maceration. When coupled with atypical loading conditions, further dermatologic problems can arise. This can significantly reduce the quality of life of an amputee patient. Improving the design of the prosthetic socket has been proposed as a means of reestablishing a normal thermal environment around the residual limb. In this study, a prosthetic socket was modified by incorporating a helical cooling channel within the socket wall using additive manufacturing techniques. Two sockets were modeled: a control socket, and a modified socket containing a 0.48 cm diameter cooling channel. Computer simulations and bench-top testing were used to assess the design's ability to create a greater temperature differential across the socket wall. A greater temperature drop across the socket wall suggested that the socket could provide cooling benefits to the residual limb by allowing for heat to be drawn away from the limb. The temperature difference across the socket wall was calculated for both sockets in each aspect of the study. Both socket type (p=0.002) and location on the socket (p=0.014) were statistically significant factors affecting the temperature difference between inner and outer socket walls. Compared with the control socket, the modified socket containing a helical cooling channel exhibited greater temperature differences across its wall of 11.1 °C and 6.4 °C in the computer simulations and bench-top testing, respectively. This finding suggested that socket modifications, such as the cooling channel presented, could provide a beneficial cooling effect to an amputee patient's residual limb.

  16. 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.

  17. 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

  18. 铝合金控制臂球头销旋铆工艺有限元分析%Simulation on the Ball Joint Sealing of Aluminum Control Arms

    Institute of Scientific and Technical Information of China (English)

    田浩彬; 李学磊; 刘晓航; 苑文婧; 鲁成伟

    2012-01-01

      汽车控制臂球头销封装是汽车底盘零件装配中的重要一环,其装配质量直接影响到汽车转向部件的寿命。采用有限元分析方法对铝合金控制臂球头销的旋铆封装技术进行了研究,对旋铆过程中铝合金控制臂的变形及受力情况进行了分析,并通过试验方法进行了验证,为汽车控制臂球头销的整体封装提供了有效的技术支持。%  Ball joint sealing of aluminum control arms is one of the key processes to the assembly of automobile chassis, which directly influents the life cycle of steering systems of automobiles. The revolving-reveting process for ball joint of control arms is studied by finite element method, and the deformation of housing is advanced and verified by experiments, which can provide technical support to the ball joint sealing of automobile control arms.

  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. Evaluating WebSocket and WebRTC in the Context of a Mobile Internet of Things Gateway

    OpenAIRE

    Karadogan, Günay Mert

    2014-01-01

    This thesis project explores two well-known real-time web technologies: WebSocket and WebRTC. It explores the use of a mobile phone as a gateway to connect wireless devices with short range of radio links to the Internet in order to foster an Internet of Things (IoT). This thesis project aims to solve the problem of how to collect real-time data from an IoT device, using the Earl toolkit. With this thesis project an Earl device is able to send real-time data to Internet connected devices and ...

  1. The Heads and Tails of Buoyant Autocatalytic Balls

    CERN Document Server

    Rogers, Michael C

    2012-01-01

    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 a large diameter, extended cylinder that is relatively free of boundary constraints, localized initiation of an iodate-arsenous acid (IAA) reaction front on the bottom boundary generates a rising autocatalytic plume. Such plumes have several differences from their non-reactive counterparts. Using numerical simulation, we have found that if reaction is initiated using a spherical ball of product solution well above the bottom boundary, the subsequent 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, except that the tail is disconnected from the boundary. In the limit of large initial autocatalytic balls, however, growth of a reacting tail is suppressed and the resemblance to plumes disappears. Conversely, very small bal...

  2. Advanced trans-tibial socket fabrication using selective laser sintering.

    Science.gov (United States)

    Rogers, Bill; Bosker, Gordon W; Crawford, Richard H; Faustini, Mario C; Neptune, Richard R; Walden, Gail; Gitter, Andrew J

    2007-03-01

    There have been a variety of efforts demonstrating the use of solid freeform fabrication (SFF) for prosthetic socket fabrication though there has been little effort in leveraging the strengths of the technology. SFF encompasses a class of technologies that can create three dimensional objects directly from a geometric database without specific tooling or human intervention. A real strength of SFF is that cost of fabrication is related to the volume of the part, not the part's complexity. For prosthetic socket fabrication this means that a sophisticated socket can be fabricated at essentially the same cost as a simple socket. Adding new features to a socket design becomes a function of software. The work at The University of Texas Health Science Center at San Antonio (UTHSCSA) and University of Texas at Austin (UTA) has concentrated on developing advanced sockets that incorporate structural features to increase comfort as well as built in fixtures to accommodate industry standard hardware. Selective laser sintering (SLS) was chosen as the SFF technology to use for socket fabrication as it was capable of fabricating sockets using materials appropriate for prosthetics. This paper details the development of SLS prosthetic socket fabrication techniques at UTHSCSA/UTA over a six-year period.

  3. Verification of BGA type FPGA logic applied to a control equipment with Safety Class using the special socket

    Energy Technology Data Exchange (ETDEWEB)

    Chung, YounHu; Yoo, Kwanwoo; Lee, Myeongkyun; Yun, Donghwa [PONUTech Co., Seoul (Korea, Republic of)

    2015-10-15

    This article aims to provide the verification method for BGA-type FPGA of Programmable Logic Controller (PLC) developed as Safety Class. The logic of FPGA in the control device with Safety Class is the circuit to control overall logic of PLC. This device converts to the different module from the input signals for both digital and analogue of the equipment in the field and outputs their data. In addition, it should perform the logical controls such as backplane communication control and data communication. We suggest acquiring method of the data signal with efficient logic using the socket in this article. Proposed test socket is made by simpler process than former one, and the process is done in batches by which cost can be reduces, and the test socket can be quickly produced in response to any request. Also, it is possible to reduce the wear by reducing the contact force of the ball phenomenon. The structure on the basis of silicon can be reduced the modification, and it has excellent linearity. At the logic verification, the operation that state data block is designed in the FPGA could be easily confirmed by using a socket.

  4. 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.

  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. Characterizations of Universal Finite Representability and B-convexity of Banach Spaces via Ball Coverings

    Institute of Scientific and Technical Information of China (English)

    Wen ZHANG

    2012-01-01

    By a ball-covering B of a Banach space X,we mean thatB is a collection of open (or closed)balls off the origin whose union contains the unit sphere of X; and X is said to have the ball-covering property provided it admits a ball-covering of countably many balls.This paper shows that universal finite representability and B-convexity of X can be characterized by properties of ball-coverings of its finite dimensioral subspaces.

  7. Real-time detecting and tracking ball with OpenCV and Kinect

    Science.gov (United States)

    Osiecki, Tomasz; Jankowski, Stanislaw

    2016-09-01

    This paper presents a way to detect and track ball with using the OpenCV and Kinect. Object and people recognition, tracking are more and more popular topics nowadays. Described solution makes it possible to detect ball based on the range, which is set by the user and capture information about ball position in three dimensions. It can be store in the computer and use for example to display trajectory of the ball.

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

    Directory of Open Access Journals (Sweden)

    Joan E. Sanders, PhD

    2012-06-01

    Full Text Available 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.

  9. Expression pattern of sonic hedgehog signaling and calcitonin gene-related peptide in the socket healing process after tooth extraction.

    Science.gov (United States)

    Pang, Pai; Shimo, Tsuyoshi; Takada, Hiroyuki; Matsumoto, Kenichi; Yoshioka, Norie; Ibaragi, Soichiro; Sasaki, Akira

    2015-11-06

    Sonic Hedgehog (SHH), a neural development inducer, plays a significant role in the bone healing process. Calcitonin gene-related peptide (CGRP), a neuropeptide marker of sensory nerves, has been demonstrated to affect bone formation. The roles of SHH signaling and CGRP-positive sensory nerves in the alveolar bone formation process have been unknown. Here we examined the expression patterns of SHH signaling and CGRP in mouse socket by immunohistochemistry and immunofluorescence analysis. We found that the expression level of SHH peaked at day 3 and was then decreased at 5 days after tooth extraction. CGRP, PTCH1 and GLI2 were each expressed in a similar pattern with their highest expression levels at day 5 and day 7 after tooth extraction. CGRP and GLI2 were co-expressed in some inflammatory cells and bone forming cells. In some areas, CGRP-positive neurons expressed GLI2. In conclusion, SHH may affect alveolar bone healing by interacting with CGRP-positive sensory neurons and thus regulate the socket's healing process after tooth extraction.

  10. 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.

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

    Science.gov (United States)

    Rowe, Philip

    2013-01-01

    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. PMID:24348164

  12. 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.

  13. Kinetic study of ferronickel slag grinding at variation of ball filling and ratio of feed to grinding balls

    Science.gov (United States)

    Sanwani, Edy; Ikhwanto, Muhammad

    2017-01-01

    The objective of this paper is to investigate the effect of ball filling and ratio of feed to grinding balls on the kinetic of grinding of ferronickel slag in a laboratory scale ball mill. The experiments were started by crushing the ferronickel slag samples using a roll crusher to produce -3 mesh (-6.7 mm) product. This product, after sampling and sample dividing processes, was then used as feed for grinding process. The grinding was performed with variations of ball filling and ratio of feed to grinding balls for 150 minutes. At every certain time interval, particle size analysis was carried out on the grinding product. The results of the experiments were also used to develop linear regression model of the effect of grinding variables on the P80 of the product. Based on this study, it was shown that P80 values of the grinding products declined sharply until 70 minutes of grinding time due to the dominant mechanism of impact breakage and then decreased slowly after 70 minutes until 150 minutes of grinding time due to dominant mechanism of attrition breakage. Kinetics study of the grinding process on variations of grinding ball filling showed that the optimum rate of formation of fine particles for 20%, 30%, 40% and 50% mill volume was achieved at a particle size of 400 µm in which the best initial rate of formation occurred at 50% volume of mill. At the variations of ratio of feed to grinding balls it was shown that the optimum rate of grinding for the ratio of 1:10, 1: 8 and 1: 6 was achieved at a particle size of 400 µm and for the ratio of 1: 4 was at 841 µm in which the best initial rate of formation occurred at a 1:10 ratio. In this study, it was also produced two regression models that can predict the P80 value of the grinding product as a function of the variables of grinding time, ball filling and the ratio of the feed to grinding balls.

  14. 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...

  15. On the Quaternion Ball and the Quaternion Projective Space

    Institute of Scientific and Technical Information of China (English)

    Qi Keng LU

    2005-01-01

    Since the quaternion ball was used to study the AdS/CFT problems for spinor fields, it is worthwhile to study further the geometry (in sense of Klein) and analysis on it and on its extended space (in the sense of Behnke-Thullen), the quaternion projective space.

  16. Unifying representation of Bézier curve and two kinds of generalized ball curves

    Institute of Scientific and Technical Information of China (English)

    ZHU Xiaolin; WANG Zhihua

    2012-01-01

    This paper presents a new basis, the WSB basis, which unifies the Bemstein basis, Wang-Ball basis and Said-Ball basis, and therefore the Bézier curve, Wang-Ball curve and Said-Ball curve are the special cases of the WSB curve based on the WSB basis In addition, the relative degree elevation formula, recursive algorithm and conversion formula between the WSB basis and the Bern- stein basis are given.

  17. Design factors for “linear” ball valve: theoretical and experimental studies

    OpenAIRE

    Thananchai Leephakpreeda

    2005-01-01

    Generic non-linear flow characteristics of the conventional ball valve limit the applications of flow modulation in fluid processes. This work presents the flow characteristics of fluid flowing through the conventional and modified ball valves for feasibility of a “linear” ball valve. Theoretical studies are discussed for determining explicit and implicit factors on the valve coefficient, which modulates the flow rate of fluid when the ball valve is operated in flow control processes. In expe...

  18. Semi-flexible sockets for amputation below the knee.

    Science.gov (United States)

    Symington, D C; Lowe, P J; Mackay, S

    1975-09-01

    A semi-flexible socket fitted to a series of 47 consecutive below-knee amputees is evaluated, and the problems in assessing prosthetic components and appropriate methodology are discussed. The results suggest that this type of socket deserves wider use and further evaluation in active amputees, where comfort, perspiration control or the condition of the skin is interfering with the patient's function.

  19. 78 FR 29702 - Ball Bearings and Parts Thereof From Germany: Final Results of Antidumping Duty Administrative...

    Science.gov (United States)

    2013-05-21

    ... International Trade Administration Ball Bearings and Parts Thereof From Germany: Final Results of Antidumping... order on ball bearings and parts thereof from Germany. The period of review (POR) is May 1, 2011... September 15, 2011, the Department revoked the order on ball bearings and parts thereof from Germany as...

  20. Assessment technique for computer-aided manufactured sockets

    Directory of Open Access Journals (Sweden)

    Joan E. Sanders, PhD

    2011-08-01

    Full Text Available This article presents an assessment technique for testing the quality of prosthetic socket fabrication processes at computer-aided manufacturing facilities. The assessment technique is potentially useful to both facilities making sockets and companies marketing manufacturing equipment seeking to assess and improve product quality. To execute the assessment technique, an evaluator fabricates a collection of test models and sockets using the manufacturing suite under evaluation, then measures their shapes using scanning equipment. Overall socket quality is assessed by comparing socket shapes with electronic file (e-file shapes. To characterize carving performance, model shapes are compared with e-file shapes. To characterize forming performance, socket shapes are compared with model shapes. The mean radial error (MRE, which is the average difference in radii between the two compared shapes, provides insight into sizing quality. Interquartile range (IQR, the range of radial error for the best-matched half of the points on the compared socket surfaces, provides insight into regional shape quality. The source(s of socket shape error may be pinpointed by separately determining MRE and IQR for carving and forming. The developed assessment technique may provide a useful tool to the prosthetics community and industry to help identify problems and limitations in computer-aided manufacturing and give insight into appropriate modifications to overcome them.

  1. 76 FR 10335 - Ball Bearings and Parts Thereof From Germany: Initiation of Antidumping Duty Changed...

    Science.gov (United States)

    2011-02-24

    ... International Trade Administration Ball Bearings and Parts Thereof From Germany: Initiation of Antidumping Duty...-circumstances review of the antidumping duty order on ball bearings and parts thereof from Germany with respect... parts thereof from Germany on May 15, 1989. See Antidumping Duty Orders: Ball Bearings,...

  2. Micro-structure and frictional characteristics of beetle's joint

    Institute of Scientific and Technical Information of China (English)

    DAI; Zhendong; Stanislav; N.; Gorb

    2004-01-01

    Geometric and micro-structure design, tribology properties of beetle joints were experimentally studied, which aimed to enlighten ideas for the joint design of MEMS.The observation by using SEM and microscopy suggested that beetle's joints consist of a concave surface matched with a convex surface. The heads of the beetles, rubbing with flat glass, were tested in fresh and dried statuses and compared with sapphire ball with flat glass. Frictional coefficient of the joint material on glass was significantly lower than that of the sapphire sphere on glass. The material of the joint cuticle for convex surface is rather stiff (the elastic modulus 4.5 Gpa) and smooth. The surface is hydrophobic (the contact angle of distilled water was 88.3° ). It is suggested here that the high stiffness of the joint material and hydrophobicity of the joint surface are parts of the mechanism minimizing friction in insect joints.

  3. 8 Pin RIC Socket for Hearing Aid Applications

    DEFF Research Database (Denmark)

    Islam, Aminul; Hansen, Hans Nørgaard; Davids, Søren;

    2012-01-01

    process and the other one is fully automated process. This paper presents the entire process chain for both the concepts and makes a comparative analysis based on the experimental investigation and validation. The work presented here can be a source of valuable information for industrial users......The current paper presents the development of an 8 Pin RIC (Receiver in the canal) Socket for hearing instruments within the framework of the COTECH project. There are 8 industrial demonstrators developed in COTECH based on the converged product and process design. Sonion’s 8 Pin RIC Socket is one...... of them. 8 Pin RIC Socket is a functionally versatile product which can combine many different functions and presents many advantages compared with the previous 3 Pin RIC Socket. For the demonstrator production of the new Socket, two different production concepts were chosen- one based on semi-automated...

  4. Prevention and Treatment of Dry Socket of 60 Cases after Tooth Extraction%60例拔牙后干槽症预防及治疗

    Institute of Scientific and Technical Information of China (English)

    蒋威

    2014-01-01

    Objective The prevention and treatment of dry socket are designed to be discussed.Methods The prevention and treatment data of 60 cases of patients suffering from dry socket are selected to analyze.Results Al patients who suffered from dry socket are cured after the treatment. Conclusion Trauma should be reduced; the tooth extraction wound should be reduced and the blood clots need to be protected in case of infection. The treatment need to be conducted for the patients with dry socket to debride the wound, isolate from the outside world, stimulate and promote the growth of granulation tissue.%目的:探讨干槽症的预防及治疗方法。方法选取60例发生干槽症患者,并对其预防处理资料进行分析。结果所有发生干槽症患者经治疗后,全部治愈。结论干槽症的预防主要是减小创伤,缩小拔牙创伤,保护血凝块,预防感染。对干槽症患者的治疗应给予清创、隔离外界刺激和促进肉芽组织生长。

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

    NARCIS (Netherlands)

    Zaal, FTJM; Michaels, CF

    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(alpha))/dt)-leads a catcher to the right location at th

  6. 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.

  7. Transforming growth factor beta 1 expression and inflammatory cells in tooth extraction socket after X-ray irradiation

    Directory of Open Access Journals (Sweden)

    Ramadhan Hardani Putra

    2017-02-01

    Full Text Available Background: Radiographic examination is often used in dentistry to evaluate tooth extraction complications. X-ray used in radiographic examination, however, has negative effects, including damage to DNA and inflammatory response during wound healing process. Purpose: This study aimed to analyze the effects of X-ray irradiation on transforming growth factor beta 1 (TGF-ß1 expression and number of inflammatory cells in tooth extraction sockets. Method: Thirty rats were divided into three groups, which consist of control group (with a radiation of 0 mSv, treatment group 1 (with a radiation of 0.08 mSv, and treatment group 2 (with a radiation of 0.16 mSv. These rats in each group were sacrificed on days 3 and 5 after treatment. Inflammatory cells which were observed in this research were PMN, macrophages, and lymphocytes. Histopathological and immunohistochemical examinations were used to calculate the number of inflammatory cells and TGF-ß1 expression. Obtained data were analyzed using SPSS 16.0 software with one way ANOVA and Tukey’s HSD tests. Result: There was no significant decrease in the number of PMN. On the other hand, there were significant decreases in the number of macrophages and lymphocytes in the sacrificed group on day-5 with the radiation of 0.16 mSv. Similarly, the most significant decreased expression of TGF-ß1 was found in the group sacrificed on day 5 with the radiation of 0.16 mSv. Conclusion: X-ray irradiation with 0.08 mSv and 0.16 mSv doses can decrease TGF-ß1 expression and number of inflammatory cells in tooth extraction sockets on day 3 and 5 post extraction.

  8. Accurate and efficient maximal ball algorithm for pore network extraction

    Science.gov (United States)

    Arand, Frederick; Hesser, Jürgen

    2017-04-01

    The maximal ball (MB) algorithm is a well established method for the morphological analysis of porous media. It extracts a network of pores and throats from volumetric data. This paper describes structural modifications to the algorithm, while the basic concepts are preserved. Substantial improvements to accuracy and efficiency are achieved as follows: First, all calculations are performed on a subvoxel accurate distance field, and no approximations to discretize balls are made. Second, data structures are simplified to keep memory usage low and improve algorithmic speed. Third, small and reasonable adjustments increase speed significantly. In volumes with high porosity, memory usage is improved compared to classic MB algorithms. Furthermore, processing is accelerated more than three times. Finally, the modified MB algorithm is verified by extracting several network properties from reference as well as real data sets. Runtimes are measured and compared to literature.

  9. Trajectory-based ball detection and tracking with aid of homography in broadcast tennis video

    Science.gov (United States)

    Yu, Xinguo; Jiang, Nianjuan; Ang, Ee Luang

    2007-01-01

    Ball-detection-and-tracking in broadcast tennis video (BTV) is a crucial but challenging task in tennis video semantics analysis. Informally, the challenges are due to camera motion and the other causes such as the presence of many ball-like objects and the small size of the tennis ball. The trajectory-based approach proposed by us in our previous papers mainly counteracted the challenges imposed by causes other than camera motion and achieves a good performance. This paper proposes an improved trajectory-based ball detection and tracking algorithm in BTV with the aid of homography, which counteracts the challenges caused by camera motion and bring us multiple new merits. Firstly, it acquires an accurate homography, which transforms each frame into the "standard" frame. Secondly, it achieved higher accuracy of ball identification. Thirdly, it obtains the ball projection position in the real world, instead of ball location in the image. Lastly, it also identifies landing frames and positions of the ball. The experimental results show that the improved algorithm can obtain not only higher accuracy in ball identification and in ball position alike, but also ball landing frames and positions. With the intent of using homography to improve the video-based event detection for smart home we also do some experiments on acquiring the homography for home surveillance video.

  10. Casimir Energy and Vacua vor Superconducting Ball in Supergravity

    CERN Document Server

    Burinskii, A

    2002-01-01

    Casimir energy for solid conducting ball is considered on the base of some finite models. One model is physical and built of a battery of parallel metallic plates. Two finite models are based on the Higgs model of superconductivity. One of them is supersymmetric and based on the Witten field model for superconducting strings. Treatment shows that contribution of Casimir energy can be very essential for superdence state in the neutron stars and nuclear matter.

  11. Entanglement and the three-dimensionality of the Bloch ball

    Energy Technology Data Exchange (ETDEWEB)

    Masanes, Ll., E-mail: ll.masanes@gmail.com [Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT (United Kingdom); Müller, M. P. [Institut für Theoretische Physik, Universität Heidelberg, Philosophenweg 19, D-69120 Heidelberg (Germany); Pérez-García, D. [Departamento de Analisis Matematico and IMI, Universidad Complutense de Madrid, 28040 Madrid (Spain); Augusiak, R. [ICFO-Institut de Ciencies Fotoniques, 08860 Castelldefels, Barcelona (Spain)

    2014-12-15

    We consider a very natural generalization of quantum theory by letting the dimension of the Bloch ball be not necessarily three. We analyze bipartite state spaces where each of the components has a d-dimensional Euclidean ball as state space. In addition to this, we impose two very natural assumptions: the continuity and reversibility of dynamics and the possibility of characterizing bipartite states by local measurements. We classify all these bipartite state spaces and prove that, except for the quantum two-qubit state space, none of them contains entangled states. Equivalently, in any of these non-quantum theories, interacting dynamics is impossible. This result reveals that “existence of entanglement” is the requirement with minimal logical content which singles out quantum theory from our family of theories.

  12. The Dual Functionals for the Generalized Ball Basis of Wang-Said Type and Basis Transformation Formulas

    Institute of Scientific and Technical Information of China (English)

    Ping Jiang; Hongyi Wu; Jieqing Tan

    2006-01-01

    The generalized Ball curves of Wang-Said type with a position parameter L not only unify the Wang-Ball curves and the Said-Ball curves, but also include several useful intermediate curves. This paper presents the dual functionals for the generalized Ball basis of Wang-Said type. The relevant basis transformation formulae are also worked out.

  13. DETERMINATION OF BALL COHESIVE AND FRICTIONAL FORCES WITH TOOL AT POLISHING BETWEEN ALIGNED RINGS AND DISK

    Directory of Open Access Journals (Sweden)

    K. G. Schetnikovich

    2010-01-01

    Full Text Available The paper provides a design description of a tool used for polishing balls made of brittle materials between bottom driving disk and two rings. An external stationary ring has a ring turning of rectangular profile that helps the ring to be based directly on the balls which are to be polished and take self-aligned position in relation to tool rotation axis.  Forces acting on the balls in the points of contact with the tool with due account of friction against a separator and conditions of ball sliding along ring working surfaces are determined in the paper. Dependence for determination of stationary and driving ring load ratio when balls are sliding along two contact surfaces of the tool is ascertained in the paper. The paper contains recommendations on selection of modes for ball polishing at its initial and finishing stages.

  14. Quantitative non-destructive evaluation of push-fit joints

    NARCIS (Netherlands)

    Arsenio, A.M.; Vreeburg, J.H.G.; Rietveld, L.

    2014-01-01

    Ultrasound, closed-circuit television (CCTV) and Panoramo (R) are capable of inspecting drinking water pipes and joints of any pipe material. The three tools were tested for their accuracy and reproducibility for gap width sizing in double-socket push-fit joints. The tests were performed at laborato

  15. Design and Fabrication of Power Supply to Heat the Titanium Ball in Vacuum Chamber of HL-2A Tokamak

    Institute of Scientific and Technical Information of China (English)

    KANGZhihua; RAOJun; ZHOUJun; WANGMingwei; CHENGanyu; ZHANGJingsong

    2003-01-01

    By using the physical characteristic of the titanium when it is subliming, fourteen titanium balls are fixed in the vacuum chamber to improve the background of the wall of the vacuum chamber of HL-2A. When the filaments of the balls have 40- 50 A current,temperatures of the balls is up to 1200 centigrade and the balls begin to sublime. Therefore in order to get better parameters of plasma, we fabricate fourteen power supplies to heat the balls.

  16. 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.

  17. The association between lower limb biomechanics and ball release speed in cricket fast bowlers: a comparison of high-performance and amateur competitors.

    Science.gov (United States)

    Middleton, Kane J; Mills, Peter M; Elliott, Bruce C; Alderson, Jacqueline A

    2016-09-01

    The aim of this study was to compare the associations between lower limb biomechanics and ball release speed in 15 high-performance (HP) and 15 amateur fast bowlers. Kinematic and kinetic variables of the lower limbs collected in the laboratory environment with a 3D Vicon motion analysis system were compared between groups, as well as their associations with ball release speed. HP bowlers had a significantly higher run-up velocity at back foot impact but this difference became non-significant at ball release. Front knee kinematics were not statistically different, however effect sizes revealed medium-large differences with the HP group displaying a more extended knee joint at maximum flexion (d = 0.72) and ball release (d = 0.76). Only front hip positive power was significantly higher in the HP group and it was suggested that the probable cause was the HP bowlers having less knee flexion after front foot impact. From a joint power analysis, the extensor muscle groups of the hip and knee were shown to be important in developing ball release speed. This highlights the need for lower limb/core strength programmes to be multifaceted and focus on the muscles associated with both power and stability.

  18. 46 CFR 154.528 - Piping joints: Flange type.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Piping joints: Flange type. 154.528 Section 154.528... and Process Piping Systems § 154.528 Piping joints: Flange type. (a) A flange must be one of the following types: (1) Welding neck. (2) Slip-on. (3) Socket weld. (b) If the piping is designed for...

  19. 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...

  20. Tests of C and CP using the Crystal Ball

    Science.gov (United States)

    Tippens, W. B.

    1995-07-01

    The installation of the SLAC Crystal Ball at BNL will initially provide measurements on several rare and forbidden neutral decays of the η. We intend to set first limits on several decay modes such as 2π0, 4π0, and 2π0γ. The first two are tests of CP invariance and the latter a test of C. In addition, we intend to improve the upper limit for the C violating decay to 3γ by roughly two orders of magnitude and make a precision measurement of the rare decay mode π0γγ.

  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 (Plaser irradiation. Conclusion Our findings suggest that laser irradiation after tooth extraction can promote osteoblast differentiation, as demonstrated by the higher expression of osteocalcin. Thus, laser irradiation could be considered a way to improve socket healing in conditions at risk for MRONJ development.

  2. Investigation of sequential cryogenic hard turning and ball burnishing processes

    Directory of Open Access Journals (Sweden)

    K. Żak

    2014-10-01

    Full Text Available This paper presents a sequential machining process which incorporates CBN hard turning with cryogenic pre-cooling of the workpiece (CHT and ball burnishing (BB. The main goal of this study was to select machining conditions enhancing the quality of parts machined by hard turning including the surface roughness Ra of about 0,2 μm, good bearing properties and reducing the white layer. Changes of surface roughness, surface texture, microstructure alterations and micro-hardness distribution are discusses.

  3. Design factors for “linear” ball valve: theoretical and experimental studies

    Directory of Open Access Journals (Sweden)

    Thananchai Leephakpreeda

    2005-03-01

    Full Text Available Generic non-linear flow characteristics of the conventional ball valve limit the applications of flow modulation in fluid processes. This work presents the flow characteristics of fluid flowing through the conventional and modified ball valves for feasibility of a “linear” ball valve. Theoretical studies are discussed for determining explicit and implicit factors on the valve coefficient, which modulates the flow rate of fluid when the ball valve is operated in flow control processes. In experiment, the cross- sectional opening area at various opening degrees, the shape, and the location of the hole passage in valve ball are examined for complicated relations dependent to the flow rate of fluid. It can be concluded that those factors cause the modulation of flow rate when the ball is turned at different opening degree. In extended design of flow characteristics for linearity, they are to be taken into account.

  4. Toeplitz and Hankel Products on Bergman Spaces of the Unit Ball

    Institute of Scientific and Technical Information of China (English)

    Yufeng LU; Chaomei LIU

    2009-01-01

    The authors give some new necessary conditions for the boundedness of Toeplitzproducts TafTagon the weighted Bergman space A2a of the unit ball, where f and g are analytic on the unit ball. Hankel products HfH*g on the weighted Bergman space of the unit ball are studied, and the results analogous to those Stroethoff and Zheng obtained in the setting of unit disk are proved.

  5. 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.

  6. 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.

  7. 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.

  8. Study on Optimizing of Ball Passing Strategy and Role Switching Mechanism for Robot Soccer

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    A new ball passing strategy for robot soccer is proposed in this paper. With introduce of a new algorithm on ball passing, the optimum strategy is confirmed to be more efficient and exact when passing a ball. Questions of role switching in multi-intelligent agent cooperation in robot soccer are described based on Generalized Stochastic Petri-Net (GSPN). Results of computer simulation have confirmed the feasibility and efficiency of above Petri-net method.

  9. Validity of method to quantify transtibial amputees’ free-living prosthetic wearing times and physical activity levels when using suction suspension sockets

    Directory of Open Access Journals (Sweden)

    Kit Tzu Tang, EngD

    2012-04-01

    Full Text Available Prostheses are prescribed to restore the mobility of people with amputated lower limbs. Monitoring the prosthesis wearing times and physical activity of prosthesis users would provide invaluable information regarding rehabilitation progress and suitability of the prosthesis. The validation of a method to determine wearing times and physical activity state, as well as strides taken, of amputees wearing suction suspension sockets is reported. Eight participants with transtibial amputation were fitted with custom-made suction sockets. Analysis algorithms were used to automatically characterize physical activity based on the pressure at the socket’s relief valve. The algorithms were validated in a laboratory-based protocol that included walking, stair climbing, standing, sitting, donning, and doffing. Intraclass correlation coefficient (2,1 values of >0.98 were achieved with mean differences of –2.0%, 0.3%, 1.3%, and 0.7% for agreement between "off," "static," and "dynamic" times and stride count, respectively, as determined by the analysis algorithms and a concurrent video analysis. This study demonstrates that an interpretation of the pressure at the pressure-relief valve of suction suspension sockets can be used to determine wearing times and activity state.

  10. A numerical and experimental study of the kinematics of a tennis ball

    Science.gov (United States)

    Navarro Sorroche, Juan

    A numerical and experimental study of the kinematics of a tennis ball. An experimental apparatus to collect data of the tennis ball in motion is designed and constructed. Data collected by the experimental apparatus is corrected by the intrinsic and extrinsic camera distortions before numeric calculation predictions of the ball's point of impact with the court are made. The experimental apparatus constructed together with comprehensive numeric computations including atmospheric conditions and spin decay, allowed making predictions of the ball's point of impact with the court with and errors <0.029%

  11. 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.

  12. FGC-15D large-diameter DTH air hammer drilling system and its application in offshore rock-socketed pile hole drilling

    Institute of Scientific and Technical Information of China (English)

    Kun YIN; Jianming PENG; Maosen WANG; Zhanjiang ZHOU

    2006-01-01

    In the past two decades, numerous large-diameter rock-socketed piles were constructed in China to support foundations of skyscrapers, great bridges or to retain soil in potential geological hazard areas. However, drilling large-diameter rock-socketed pile holes with conventional drilling method such as rotary drilling or cable tool drilling is time-consuming and the cost is usually very high. In order to drill large-diameter rock-socketed pile holes faster at relatively low cost, the FGC15A large-diameter DTH air hammer drilling system was developed in 1987 and was given the second-class award by Ministry of Geology and Mineral Resources in 1991. Since it was innovated the drilling system has been used in more than twenty important and tough projects on land, and wonderful results were acquired. At the same time the large-diameter DTH air hammer drilling system was improved continuously. The FGC15D is the latest version of the technique.

  13. Examination of anticipated chemical shift and shape distortion effect on materials commonly used in prosthetic socket fabrication when measured using MRI: a validation study.

    Science.gov (United States)

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

    2013-01-01

    The quality of lower-limb prosthetic socket fit is influenced by shape and volume consistency during the residual limb shape-capturing process (i.e., casting). Casting can be quantified with magnetic resonance imaging (MRI) technology. However, chemical shift artifact and image distortion may influence the accuracy of MRI when common socket/casting materials are used. We used a purpose-designed rig to examine seven different materials commonly used in socket fabrication during exposure to MRI. The rig incorporated glass marker tubes filled with water doped with 1 g/L copper sulfate (CS) and 9 plastic sample vials (film containers) to hold the specific material specimens. The specimens were scanned 9 times in different configurations. The absolute mean difference of the glass marker tube length was 1.39 mm (2.98%) (minimum = 0.13 mm [0.30%], maximum = 5.47 mm [14.03%], standard deviation = 0.89 mm). The absolute shift for all materials was <1.7 mm. This was less than the measurement tolerance of +/-2.18 mm based on voxel (three-dimensional pixel) dimensions. The results show that MRI is an accurate and repeatable method for dimensional measurement when using matter containing water. Additionally, silicone and plaster of paris plus 1 g/L CS do not show a significant shape distortion nor do they interfere with the MRI image of the residual limb.

  14. Examination of anticipated chemical shift and shape distortion effect on materials commonly used in prosthetic socket fabrication when measured using MRI: A validation study

    Directory of Open Access Journals (Sweden)

    Mohammad Reza Safari, PhD

    2013-02-01

    Full Text Available The quality of lower-limb prosthetic socket fit is influenced by shape and volume consistency during the residual limb shape-capturing process (i.e., casting. Casting can be quantified with magnetic resonance imaging (MRI technology. However, chemical shift artifact and image distortion may influence the accuracy of MRI when common socket/casting materials are used. We used a purpose-designed rig to examine seven different materials commonly used in socket fabrication during exposure to MRI. The rig incorporated glass marker tubes filled with water doped with 1 g/L copper sulfate (CS and 9 plastic sample vials (film containers to hold the specific material specimens. The specimens were scanned 9 times in different configurations. The absolute mean difference of the glass marker tube length was 1.39 mm (2.98% (minimum = 0.13 mm [0.30%], maximum = 5.47 mm [14.03%], standard deviation = 0.89 mm. The absolute shift for all materials was <1.7 mm. This was less than the measurement tolerance of +/–2.18 mm based on voxel (three-dimensional pixel dimensions. The results show that MRI is an accurate and repeatable method for dimensional measurement when using matter containing water. Additionally, silicone and plaster of paris plus 1 g/L CS do not show a significant shape distortion nor do they interfere with the MRI image of the residual limb.

  15. 插座防脱技术研究与应用%Research and Application of Self-locking Technology of Socket

    Institute of Scientific and Technical Information of China (English)

    蔡映峰

    2014-01-01

    Self-locking socket could prevent plug being pulled out at the locking mode, and the plug would be pulled out normally at its unlocking mode. In a certain occasion, this kind of socket could reduce the dangerous accident effectively by preventing running equipment sud-denly being power off due to loosen power connection. In this paper, it analyzes several solu-tions for self-locking socket, elaborates the key technology, self-locking principle, theoret-ical calculation as well as the difficulties and technical solution of structure design based on design requirement. It provides the theory basis for products design.%防脱插座是一种插头在锁定状态下可方便插入不易拔出,解锁状态下又能容易拔出的插座,这在某些场合可有效防止用电设备因掉电引起的事故或危害。本文根据设计要求分析了插座防脱的各种技术方案,阐述了实施例中的关键技术、自锁原理、设计计算以及结构设计中的难点和解决办法,为防脱插座的产品设计提供了理论基础。

  16. Conservative Socket Regeneration with Buccal Wall Defect Using Guided Tissue.

    Science.gov (United States)

    Al-Juboori, Mohammed Jasim

    2016-01-01

    Progressive alveolar bone resorption after tooth extraction may lead to surgical and prosthetic-driven difficulties, especially when deciding to use a dental implant to replace the extracted tooth. This case report discusses an irreparable lower left second premolar tooth with a periodontal lesion on the buccal side. A preservative tooth extraction was performed. Then, the socket was grafted with bovine bone, a collagen membrane was placed between the buccal bone and the attached gingiva, covering the bone dehiscence buccally, and the socket without a flap was raised. After a 6-month healing period, there was minimal socket width resorption and a shallow buccal vestibule. The implant was placed with high primary stability and sufficient buccal plate thickness. In conclusion, this guided tissue regeneration technique can minimize alveolar bone resorption in a socket with buccal dehiscence, but technical difficulties and shallowing of the buccal vestibule still exist.

  17. Evaluation of stability of immediately placed implants in infected sockets

    Directory of Open Access Journals (Sweden)

    Uma Shankar Pal

    2013-01-01

    Full Text Available Purpose: To describe a protocol for the immediate placement of implant into the infected alveolar socket. Materials and Methods: In this study, a total number of 40 implants were placed immediately into the extraction sockets. Each case had a different periapical condition (acute, endodontic and periodontal infection. Great care had been taken in debridement of the socket, extraction of tooth/teeth and guided bone regeneration along with the use of pre-operative and post-operative anti-microbial agent. Results: All except three implants were osseo-integrated within 6 months to 1 year. The complications were due to the extraction procedure and bone regeneration process. Conclusion: Predisposing factors for failures are incomplete debridement of the socket, poor oral hygiene, incomplete closure of the wound, and systemic factors like hormones. From this study, we may conclude that immediate implants are a viable treatment option for patients with periapical infections.

  18. Conservative Socket Regeneration with Buccal Wall Defect Using Guided Tissue

    Science.gov (United States)

    Al-Juboori, Mohammed Jasim

    2016-01-01

    Progressive alveolar bone resorption after tooth extraction may lead to surgical and prosthetic-driven difficulties, especially when deciding to use a dental implant to replace the extracted tooth. This case report discusses an irreparable lower left second premolar tooth with a periodontal lesion on the buccal side. A preservative tooth extraction was performed. Then, the socket was grafted with bovine bone, a collagen membrane was placed between the buccal bone and the attached gingiva, covering the bone dehiscence buccally, and the socket without a flap was raised. After a 6-month healing period, there was minimal socket width resorption and a shallow buccal vestibule. The implant was placed with high primary stability and sufficient buccal plate thickness. In conclusion, this guided tissue regeneration technique can minimize alveolar bone resorption in a socket with buccal dehiscence, but technical difficulties and shallowing of the buccal vestibule still exist. PMID:27857817

  19. Performance of hybrid ball bearings in oil and jet fuel

    Science.gov (United States)

    Schrader, Stephen M.; Pfaffenberger, Eugene E.

    1992-07-01

    A 308-size hybrid ball bearing, with ceramic balls and steel rings, was tested using a diester oil and gas turbine fuel as lubricants at several speeds and loads. Heat generation data from this test work was then correlated with the heat generation model from a widely used computer code. The ability of this hybrid split inner ring bearing design to endure thrust reversals, which are expected in many turbine applications, was demonstrated. Finally, the bearing was successfully endurance tested in JP-10 fuel for 25 hours at 7560 N axial load and 36,000 rpm. This work has successfully demonstrated the technology necessary to use fuel-lubricated hybrid bearings in limited-life gas turbine engine applications such as missiles, drones, and other unmanned air vehicles (UAVs). In addition, it has provided guidance for use in designing such bearing systems. As a result, the benefits of removing the conventional oil lubricant system, i.e., design simplification and reduced maintenance, can be realized.

  20. Prosthetic Correction of Postenucleation Socket Syndrome: A Case Report.

    Science.gov (United States)

    Kamble, Vikas B

    2014-12-01

    Postenucleation socket syndrome is a frequent late complication of enucleation of eye globe. Several pathophysiological mechanisms have been proposed to account for the symptoms of postenucleation socket syndrome, which include lost orbital volume, superior sulcus deformity, upper eyelid ptosis, lower eyelid laxity, and backward tilt of the prosthesis. The goal of postenucleation socket syndrome treatment is to achieve the best possible functional and esthetic result. The treatment can be either conservative or surgical. For the patient interested in a non-surgical correction, the conservative treatment is simple and non invasive and can be done with prosthesis modification for good positioning, comfort, and mobility. This paper describes prosthetic correction of a patient with postenucleation socket syndrome by modified ocular prosthesis.

  1. The development of a rapid prototyping prosthetic socket coated with a resin layer for transtibial amputees.

    Science.gov (United States)

    Hsu, L H; Huang, G F; Lu, C T; Hong, D Y; Liu, S H

    2010-03-01

    This article proposes a type of transtibial socket composed of an inner layer fabricated by a rapid prototyping (RP) machine and an outer layer coated with unsaturated polyester resin. This work integrates contemporary technologies including a handheld scanner and CAD systems, to design a thin primary socket shape and then manufactures the socket using a fused deposition-modeling machine. To prevent breakage caused by the layer-based forming process and to reinforce flexural strength, the current research coats the preliminary RP socket with a layer of unsaturated polyester resin. After shaping the proximal brim of the resin-reinforced RP socket to match the specific stump, this study assembles and aligns a shank and a prosthetic foot to form a prosthesis set. After completing a trial safety walk wearing the prosthesis, which is satisfactory to the amputee and a registered prosthetist, this research measures interface pressures between the stump and the resin-reinforced RP socket. Experiment results demonstrate that the resin-reinforced RP socket is applicable for transtibial amputees. In addition to strengthening the FDM socket and producing consistent socket fit, this study also demonstrates a feasible procedure that employs current technologies to design and manufacture transtibial sockets without plaster moulds.

  2. 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…

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

    DEFF Research Database (Denmark)

    Andersen, Thomas Bull; Krustrup, Peter; Bendiksen, Mads;

    2016-01-01

    The present study evaluated the effect of a smaller, lighter ball on kicking speed and technical-tactical and physical match performance in high-level adult female footballers. In the laboratory test setting, the peak ball velocity was 6% higher with the new ball (NB) than the standard ball (SB...... 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...

  4. 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…

  5. 76 FR 58768 - Ball Bearings and Parts Thereof From France, Germany, and Italy; Amended Final Results of...

    Science.gov (United States)

    2011-09-22

    ... International Trade Administration Ball Bearings and Parts Thereof From France, Germany, and Italy; Amended... ball bearings and parts thereof from France, Germany, and Italy. See Ball Bearings and Parts Thereof From France, Germany, and Italy: Final Results of Antidumping Administrative and Changed...

  6. 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.

  7. 75 FR 3444 - Ball Bearings and Parts Thereof From Germany: Initiation of Antidumping Duty Changed...

    Science.gov (United States)

    2010-01-21

    ... International Trade Administration Ball Bearings and Parts Thereof From Germany: Initiation of Antidumping Duty... the antidumping duty order on ball bearings and parts thereof from Germany with respect to myonic GmbH... spherical plain bearings and parts thereof from Germany on May 15, 1989. See Antidumping Duty Orders:...

  8. 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.

  9. 77 FR 73415 - Ball Bearings and Parts Thereof From France, Germany, and Italy: Final Results of Antidumping...

    Science.gov (United States)

    2012-12-10

    ... International Trade Administration Ball Bearings and Parts Thereof From France, Germany, and Italy: Final... ball bearings and parts thereof from France, Germany, and Italy. On October 16, 2012, the Department... antidumping duty orders on ball bearings and parts thereof from France, Germany, and Italy.\\1\\ The period...

  10. 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

    ... International Trade Administration Ball Bearings and Parts Thereof from France, Germany, and Italy: Extension of... antidumping duty orders on ball bearings and parts thereof from France, Germany, Italy, Japan, and the United... reviews of the orders. \\2\\ See Ball Bearings and Parts Thereof from France, Germany, and Italy:...

  11. 75 FR 69402 - Ball Bearings and Parts Thereof From France, Germany, Italy, Japan, and the United Kingdom...

    Science.gov (United States)

    2010-11-12

    ... International Trade Administration Ball Bearings and Parts Thereof From France, Germany, Italy, Japan, and the... antidumping duty orders on ball bearings and parts thereof from France, Germany, Italy, Japan, and the United... duty orders on ball bearings and parts thereof from France, Germany, Italy, Japan, and the...

  12. A look into the Medical and Veterinary Entomology crystal ball.

    Science.gov (United States)

    Dantas-Torres, F; Cameron, M M; Colwell, D D; Otranto, D

    2014-08-01

    Medical and Veterinary Entomology (MVE) represents a leading periodical in its field and covers many aspects of the biology and control of insects, ticks, mites and other arthropods of medical and veterinary importance. Since the first issue of the journal, researchers working in both developed and developing countries have published in MVE, with direct impact on current knowledge in the field. An increasing number of articles dealing with the epidemiology and transmission of vector-borne pathogens have been published in MVE, reflecting rapid changes in vector distribution, pathogen transmission and host-arthropod interactions. This article represents a gaze into the crystal ball in which we identify areas of increasing interest, discuss the main changes that have occurred in the epidemiology of parasitic arthropods since the first issue of MVE, and predict the principal scientific topics that might arise in the next 25 years for scientists working in medical and veterinary entomology.

  13. 78 FR 9674 - Ball Bearings and Parts Thereof From Germany: Preliminary Results of Antidumping Duty...

    Science.gov (United States)

    2013-02-11

    ... International Trade Administration Ball Bearings and Parts Thereof From Germany: Preliminary Results of... thereof from Germany. The period of review (POR) is May 1, 2011, through September 14, 2011.\\1\\ We..., 2011, the Department revoked the order on ball bearings and parts thereof from Germany as...

  14. 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.

  15. 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…

  16. 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/

  17. Efficacy of amoxicillin and amoxicillin/clavulanic acid in the prevention of infection and dry socket after third molar extraction. A systematic review and meta-analysis

    Science.gov (United States)

    Arteagoitia, María-Iciar; Barbier, Luis; Santamaría, Gorka; Ramos, Eva

    2016-01-01

    Background Prophylactic use of amoxicillin and amoxicillin/clavulanic acid, although controversial, is common in routine clinical practice in third molar surgery. Material and Methods Our objective was to assess the efficacy of prophylactic amoxicillin with or without clavulanic acid in reducing the incidence of dry socket and/or infection after third molar extraction. We conducted a systematic review and meta-analysis consulting electronic databases and references in retrieved articles. We included double-blind placebo-controlled randomized clinical trials published up to June 2015 investigating the efficacy of amoxicillin with or without clavulanic acid on the incidence of the aforementioned conditions after third molar extraction. Relative risks (RRs) were estimated with a generic inverse-variance approach and a random effect model using Stata/IC 13 and Review Manager Version 5.2. Stratified analysis was performed by antibiotic type. Results We included 10 papers in the qualitative review and in the quantitative synthesis (1997 extractions: 1072 in experimental groups and 925 in controls, with 27 and 74 events of dry socket and/or infection, respectively). The overall RR was 0.350 (p< 0.001; 95% CI 0.214 to 0.574). We found no evidence of heterogeneity (I2=0%, p=0.470). The number needed to treat was 18 (95% CI 13 to 29). Five studies reported adverse reactions (RR=1.188, 95% CI 0.658 to 2.146, p =0.567). The RRs were 0.563 for amoxicillin (95% CI 0.295 to 1.08, p=0.082) and 0.215 for amoxicillin/clavulanic acid (95% CI 0.117 to 0.395, p<0.001). Conclusions Prophylactic use of amoxicillin does not significantly reduce the risk of infection and/or dry socket after third molar extraction. With amoxicillin/clavulanic acid, the risk decreases significantly. Nevertheless, considering the number needed to treat, low prevalence of infection, potential adverse reactions to antibiotics and lack of serious complications in placebo groups, the routine prescription of

  18. Preparation and performance research of Ce-TiO2/KL ball photocatalysts

    Institute of Scientific and Technical Information of China (English)

    于晓娟; 熊领领; 马国平; 梁愿; 刘奎仁

    2014-01-01

    The Ce-TiO2/KL (diatomite) ball photocatalyst was prepared and characterized based on the pretreated diatomite. The re-sults showed that comparing with the crude diatomite, proper pretreatment could significantly improve its SiO2 purity and specific surface area. The surface of diatomite was clear with uniform pore structure and big pore size. With diatomite ball as carrier, the sup-ported Ce-TiO2/KL ball photocatalyst was prepared by sol-gel method. The photocatalytic performances of the supported Ce-TiO2/ KL ball and Ce-TiO2/KL powder photocatalysts under various preparation conditions were studied in view of photocatalytic degrada-tion rate of Rhodamine B (Rh B) solution. The degradation rate of the ball photocatalysts for Rh B reached 94.6% and could be re-used for many times, which showed much better photocatalytic performance and stability than powder photocatalysts.

  19. Moisture permeability of the total surface bearing prosthetic socket with a silicone liner: is it superior to the patella-tendon bearing prosthetic socket?

    Science.gov (United States)

    Hachisuka, K; Matsushima, Y; Ohmine, S; Shitama, H; Shinkoda, K

    2001-09-01

    The purpose of this study was to examine the moisture permeability properties of materials used for total surface bearing (TSB) socket with a silicone liner, a combination of Silicone Suction Socket or Icelandic Roll-On Silicone Socket (ICEROSS) and an acrylic plastic sheet (Degaplast), patella-tendon bearing (PTB) socket, a combination of Pe-Lite and Degaplast, and wooden socket made of poplar. Moisture permeability of the socket materials was measured as the diminution of water in a container after 12 hours in a climatic chamber. Eight containers with their open, top side were uncovered (no material) or sealed with one of the socket materials; the experiment was repeated four times. One-way analysis of variance followed by Bonferroni's test was applied to examine the differences in moisture permeability. Moisture permeability levels were as follows: no material, 85.9 +/- 1.3 g; poplar, 4.3 +/- 0.4 g; Silicone Suction Socket, 1.1 +/- 0.2 g; ICEROSS, 1.0 +/- 0.2 g; Pe-Lite, 0.8 +/- 0.1 g; 3S + Degaplast, 0.8 +/- 0.1 g; ICEROSS + Degaplast, 0.8 +/- 0.2 g; and Pe-Lite + Degaplast, 0.8 +/- 0.1 g. There were significant differences between the uncovered container and the others, and between poplar and the others (P socket with a silicone liner is not superior to the PTB socket with regard to moisture permeability, and that it is necessary to develop a new prosthetic socket that allows heat release and drainage of sweat.

  20. Interface load analysis for computer-aided design of below-knee prosthetic sockets.

    Science.gov (United States)

    Reynolds, D P; Lord, M

    1992-07-01

    A finite-element analysis is made for the compression of soft tissues of the residual lower limb contained in a prosthetic socket. The analysis is relevant to static loading during stance in a patellar-tendon-bearing, below-knee design of socket. Values of Young's modulus are obtained experimentally for use in the model. One of the main objectives is to study the sensitivity of the loading to these values and also to other assumed conditions. Using direct pressure at the limb/socket interface and vertical stiffness as indicators, changes in material properties, socket alignment and socket rectification are investigated; assumptions about the frictional characteristic at the interface are seen to be critical in determination of load distribution. This type of analysis may provide the next stage of refinement for computer-aided socket design systems.

  1. Structure, attachment, replacement and growth of teeth in bluefish, Pomatomus saltatrix (Linnaeus, 1776), a teleost with deeply socketed teeth.

    Science.gov (United States)

    Bemis, William E; Giuliano, Anne; McGuire, Betty

    2005-01-01

    Tooth replacement poses many questions about development, pattern formation, tooth attachment mechanisms, functional morphology and the evolution of vertebrate dentitions. Although most vertebrate species have polyphyodont dentitions, detailed knowledge of tooth structure and replacement is poor for most groups, particularly actinopterygians. We examined the oral dentition of the bluefish, Pomatomus saltatrix, a pelagic and coastal marine predator, using a sample of 50 individuals. The oral teeth are located on the dentary and premaxillary bones, and we scored each tooth locus in the dentary and premaxillary bones using a four-part functional classification: absent (A), incoming (I), functional (F=fully ankylosed) or eroding (E). The homodont oral teeth of Pomatomus are sharp, deeply socketed and firmly ankylosed to the bone of attachment. Replacement is intraosseus and occurs in alternate tooth loci with long waves of replacement passing from rear to front. The much higher percentage of functional as opposed to eroding teeth suggests that replacement rates are low but that individual teeth are quickly lost once erosion begins. Tooth number increases ontogenetically, ranging from 15-31 dentary teeth and 15-39 premaxillary teeth in the sample studied. Teeth increase in size with every replacement cycle. Remodeling of the attachment bone occurs continuously to accommodate growth. New tooth germs originate from a discontinuous dental lamina and migrate from the lingual (dentary) or labial (premaxillary) epithelium through pores in the bone of attachment into the resorption spaces beneath the existing teeth. Pomatomus shares unique aspects of tooth replacement with barracudas and other scombroids and this supports the interpretation that Pomatomus is more closely related to scombroids than to carangoids.

  2. 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.

  3. Electric field strength of charged conducting balls and the breakdown of the air gap between them

    Energy Technology Data Exchange (ETDEWEB)

    Saranin, Vladimir A [Department of Physics, V.G. Korolenko Glazov State Pedagogical Institute, Glazov (Russian Federation)

    2002-12-31

    Field amplification factors at the surfaces of two charged conducting balls are calculated numerically. It is shown that as the balls are brought closer together, except when their potentials are equal, the amplification factors go to infinity, and in the case of like-charged balls the field at the surface of one of them changes sign. Breakdown field strengths for the air gap between balls of a different diameter are calculated using the experimental data of other authors as the base. The results suggest that the minimum breakdown field strength is 26 kV cm{sup -1} . The author's earlier results on the interaction force between the balls are revised. (methodological notes)

  4. Extension of Relativistic-Microwave Theory of Ball Lightning Including Long-term Losses And Stability

    CERN Document Server

    Stephan, Karl D

    2016-01-01

    After centuries, the long-standing problem of the nature of ball lightning may be closer to a solution. The relativistic-microwave theory of ball lightning recently proposed by Wu accounts for many of the leading characteristics of ball lightning, which most previous theories have failed to do. It involves the impact of a lightning-caused relativistic electron bunch to soil, producing an EM pulse that forms a plasma bubble. While the theory presents a plausible account of ball-lightning formation, storing electromagnetic energy long enough to account for the observed lifetime of such objects was not demonstrated. Here we show how such a structure can develop the high Q factor (~10^10) needed for the observed lifetimes of ~seconds for ball lightning, and show that the structure is radially stable, given certain assumptions.

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

    Science.gov (United States)

    Hu, Hongcheng; Pu, Yinfei; Lu, Songhe; Zhang, Kuo; Guo, Yuan; Lu, Hui; Li, Deli; Li, Xuefen; Li, Zichen; Wu, Yuwei; Tang, Zhihui

    2015-10-20

    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 OPEN ACCESS Int. J. Mol. Sci. 2015, 16 24947 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. 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.

  7. Physics of ball sports

    Science.gov (United States)

    Cohen, C.; Clanet, C.

    2016-06-01

    Ball sports have been part of human history for thousands of years [1]. Nowadays, 13 of them are part of the Olympic games (badminton, basketball, beach volley, football/soccer, golf, handball, hockey, rugby, table tennis, tennis, volleyball, water polo, ice hockey). All these games differ by launcher (hand, club, racket, bat), ball (size, shape and mass), pitch size and number of players. These differences induce different ball velocities. Apart from the velocities and the way to maximize them, we discuss in this article the ball trajectories and their impact on the size of sports fields.

  8. Coronal plane socket stability during gait in persons with transfemoral amputation: Pilot study.

    Science.gov (United States)

    Fatone, Stefania; Dillon, Michael; Stine, Rebecca; Tillges, Robert

    2014-01-01

    Little research describes which transfemoral socket design features are important for coronal plane stability, socket comfort, and gait. Our study objectives were to (1) relate socket comfort during gait to a rank order of changes in ischial containment (IC) and tissue loading and (2) compare socket comfort during gait when tissue loading and IC were systematically manipulated. Six randomly assigned socket conditions (IC and tissue compression) were assessed: (1) IC and high, (2) IC and medium, (3) IC and low, (4) no IC and high, (5) no IC and medium, and (6) no IC and low. For the six subjects in this study, there was a strong, negative relationship between comfort and changes in IC and tissue loading (rho = -0.89). With the ischium contained, tissue loading did not influence socket comfort (p = 0.47). With no IC, the socket was equally comfortable with high tissue loading (p = 0.36) but the medium (p = 0.04) and low (p = 0.02) tissue loading conditions decreased comfort significantly. Coronal plane hip moments, lateral trunk lean, step width, and walking speed were invariant to changes in IC and/or tissue loading. Our results suggest that in an IC socket, medial tissue loading mattered little in terms of comfort. Sockets without IC required high tissue loading to be as comfortable as those with IC, while suboptimal tissue loading compromised comfort.

  9. Coronal plane socket stability during gait in persons with transfemoral amputation: Pilot study

    Directory of Open Access Journals (Sweden)

    Stefania Fatone, PhD, BPO(Hons

    2015-01-01

    Full Text Available Little research describes which transfemoral socket design features are important for coronal plane stability, socket comfort, and gait. Our study objectives were to (1 relate socket comfort during gait to a rank order of changes in ischial containment (IC and tissue loading and (2 compare socket comfort during gait when tissue loading and IC were systematically manipulated. Six randomly assigned socket conditions (IC and tissue compression were assessed: (1 IC and high, (2 IC and medium, (3 IC and low, (4 no IC and high, (5 no IC and medium, and (6 no IC and low. For the six subjects in this study, there was a strong negative relationship between comfort and changes in IC and tissue loading (rho = −0.89. With the ischium contained, tissue loading did not influence socket comfort (p = 0.47. With no IC, the socket was equally comfortable with high tissue loading (p = 0.36 but the medium (p = 0.04 and low (p = 0.02 tissue loading conditions decreased comfort significantly. Coronal plane hip moments, lateral trunk lean, step width, and walking speed were invariant to changes in IC and/or tissue loading. Our results suggest that in an IC socket, medial tissue loading mattered little in terms of comfort. Sockets without IC required high tissue loading to be as comfortable as those with IC, while suboptimal tissue loading compromised comfort.

  10. Ultrasonic b-scan image compounding technique for prosthetic socket design

    Science.gov (United States)

    Xue, Kefu; He, Ping; Fu, Huimin; Bismar, Hisham

    1991-11-01

    Prosthetic socket design is the most important aspect of the fit of a lower extremity prosthesis. The comfort and mobility of wearing a prosthetic socket mainly depends on the design of weight bearing characteristics of the socket. The weight bearing characteristics of a socket are determined by the relative positions among the tissues (such as bones, muscles, and fat) of the residual limb and the wall of the socket. Therefore, socket fitting cannot be guaranteed if the internal structural information of a residual limb is not made available to the prosthetist. Current prosthetic socket design and manufacture processes are disadvantaged by the inherent difficulties in determining the weight bearing characteristics of a socket due to the lack of crucial information about the internal structure of the residual limb, such as bone position, and muscle, and fat distribution. This disadvantage can be overcome through the use of an ultrasound imaging system and a computer-aided socket design system. The discussion of the complete system is out of the scope of this paper. An ultrasound imaging algorithm which provides the external shape of the limb, the bone position, and the texture pattern of the soft tissues within the limb is presented in this paper. The algorithm using the Compound B-scan imaging principle combined with geometrical transformation and statistical information faithfully measures and reconstructs with topographical shape and internal structure information of a residual limb.

  11. Using computational simulation to aid in the prediction of socket fit: a preliminary study.

    Science.gov (United States)

    Lee, Winson C C; Zhang, Ming

    2007-10-01

    This study illustrates the use of computational analysis to predict prosthetic socket fit. A simple indentation test is performed by applying force to the residual limb of a trans-tibial amputee through an indenter until the subject perceives the onset of pain. Computational finite element (FE) analysis is then applied to evaluate the magnitude of pressure underlying the indenter that initiates pain (pain threshold pressure), and the pressure at the prosthetic socket-residual limb interface. The assessment of socket fit is examined by studying whether or not the socket-limb interface pressure exceeds the pain threshold pressure of the limb. Based on the computer-aided assessment, a new prosthetic socket is then fabricated and fitted to the amputee subject. Successful socket fit is achieved at the end of this process. The approach of using computational analysis to aid in assessing socket fit allows a more efficient evaluation and re-design of the socket even before the actual fabrication and fitting of the prosthetic socket. However, more thorough investigations are required before this approach can be widely used. A subsequent part of this paper discusses the limitations and suggests future research directions in this area.

  12. 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.

  13. 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)...

  14. 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.

  15. Fabrication and measurement of nanostructures on the micro ball surface using a modified atomic force microscope

    Science.gov (United States)

    Zhao, X. S.; Geng, Y. Q.; Li, W. B.; Yan, Y. D.; Hu, Z. J.; Sun, T.; Liang, Y. C.; Dong, S.

    2012-11-01

    In order to machine and measure nanostructures on the micro ball surface, a modified atomic force microscope (AFM) combining a commercial AFM system with a home built precision air bearing spindle is established. Based on this system, motions of both the AFM scanner and the air bearing spindle are controlled to machine nanostructures on the micro ball based on the AFM tip-based nano mechanical machining approach. The eccentric error between the axis of the micro ball and the axis of the spindle is reduced to 3-4 μm by the provided fine adjusting method. A 1000 nano lines array, 36 square pits structure, 10 square pits structure, and a zig-zag structure on the circumference of the micro ball with the diameter of 1.5 mm are machined successfully. The measurement results achieved by the same system reveal that the profiles and mode-power spectra curves of the micro ball are influenced by the artificially machined nanostructures significantly according to their distributions. This work is an useful attempt for modifying the micro ball profile and manufacture of the spherical modulation targets to study the experimental performance of the micro ball in implosion.

  16. Visual Servoing Tracking Control of a Ball and Plate System: Design, Implementation and Experimental Validation

    Directory of Open Access Journals (Sweden)

    Ming-Tzu Ho

    2013-07-01

    Full Text Available This paper presents the design, implementation and validation of real‐time visual servoing tracking control for a ball and plate system. The position of the ball is measured with a machine vision system. The image processing algorithms of the machine vision system are pipelined and implemented on a field programmable gate array (FPGA device to meet real‐ time constraints. A detailed dynamic model of the system is derived for the simulation study.By neglecting the high‐order coupling terms, the ball and plate system model is simplified into two decoupled ball and beam systems, and an approximate input‐ output feedback linearization approach is then used to design the controller for trajectory tracking. The designed control law is implemented on a digital signal processor (DSP. The validity of the performance of the developed control system is investigated through simulation and experimental studies. Experimental results show that the designed system functions well with reasonable agreement with simulations.

  17. Patient satisfaction and treatment outcome of fungus ball rhinosinusitis treated by functional endoscopic sinus surgery.

    Science.gov (United States)

    Lai, Jui-Chung; Lee, Hong-Shen; Chen, Mu-Kuan; Tsai, Yao-Lung

    2011-02-01

    Fungal rhinosinusitis is an important clinical problem with diverse manifestations. Although many literatures had found low recurrence rate after surgical treatment of fungus ball rhinosinusitis, patient satisfaction and treatment outcomes (symptom-free and symptom improvement rate, etc.) for fungus ball sinusitis are not yet well established. The purpose of this study is to estimate the patient satisfaction and treatment outcome in patients with fungus ball rhinosinusitis undergoing functional endoscopic sinus surgery (FESS). Medical records of consecutive patients with diagnosed fungus ball rhinosinusitis treated by FESS between 1995 and 2005 were reviewed retrospectively. The post-operative improvement in individual symptom was assessed by chart review and telephone visiting. Ninety consecutive patients (21 men and 69 women) were eligible for the study. Six patients (7%) presented bilateral fungus ball rhinosinusitis. Multiple paranasal sinus fungus ball involvements were found in 48 patients (53%). Complete resolution of complaints with respect to nasal discharge, postnasal drip, cough with sputum, nasal bleeding, fetid odor of nose, olfactory dysfunction, nasal obstruction, headache, and facial pain or pressure were described in 74 patients (82%). The overall patient satisfaction rate was 96%. The estimated recurrence rate of fungus ball rhinosinusitis treated with FESS was 3%, with a mean follow-up of 81 months. Treatment protocol of fungus ball rhinosinusitis with FESS and without postoperative antifungal drugs is efficient because of very low recurrence rate, high patient satisfaction, and very high symptom-free rate. Furthermore, the obvious difference of symptom-free rate between fungus ball rhinosinusitis and chronic rhinosinusitis highlights the need of further studies to discover the pathophysiology of fungal sinusitis.

  18. 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

  19. 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.

  20. Joint Custody and Coparenting.

    Science.gov (United States)

    Sell, Kenneth D.

    Results are presented of an intensive search of U.S. newspapers and periodicals on the joint custody of children after divorce, where both parents have continued responsibility for parenting and where the children spend part of each week, month, or year with both of the parents. Areas of concern addressed by these materials include the following:…

  1. Physical Analysis of the Drag and Magnus Coefficients of the Topspin Tennis Ball

    Science.gov (United States)

    Smith, Elizabeth; Howald, Craig

    2007-05-01

    We experimentally determined the drag and Magnus coefficients of a topspin tennis ball using video analysis. Three video cameras were used to record the initial spin, projectile motion, and final spin of the ball. From these recordings the initial velocity, initial spin, final spin, horizontal acceleration, vertical acceleration, x position, and y positions of the ball were extracted. The coefficient of drag was calculated to be CD=0.6104 +/-0.06187 and the Magnus coefficient was calculated to be CM=0.6576+/-0.08767. To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2007.OSS07.P1.14

  2. Evaluation of outer race tilt and lubrication on ball wear and SSME bearing life reductions

    Science.gov (United States)

    Kannel, J. W.; Merriman, T. L.; Stockwell, R. D.; Dufrane, K. F.

    1983-01-01

    Several aspects of the SSME bearing operation were evaluated. The possibility of elastohydrodynamics (EHD) lubrication with a cryogenic fluid was analyzed. Films as thick as .61 microns were predicted with one theory which may be thick enough to provide hydrodynamic support. The film formation, however, is heavily dependent on good surface finish and a low bulk bearing temperature. Bearing dynamics to determine if the radial stiffness of a bearing which are dependent on bearing misalignment were analyzed. Four ball tests were conducted at several environmental conditions from an LN2 bath to 426 C in air. Surface coatings and ball materials are evaluated. Severe wear and high friction are measured for all ball materials except when the balls have surface lubricant coatings.

  3. Maxillary reconstruction and placement of dental implants after treatment of a maxillary sinus fungus ball.

    Science.gov (United States)

    Colletti, Giacomo; Felisati, Giovanni; Biglioli, Federico; Tintinelli, Roberto; Valassina, Davide

    2010-01-01

    A fungus ball is one of the fungal diseases that can affect the paranasal sinuses. It requires surgical treatment. Because there is only one previously reported case of dental implant placement after treatment of a maxillary sinus fungus ball, the authors here report on a case of a maxillary sinus fungus ball with bone erosion that was treated surgically with a combined endoscopic endonasal and endoral (Caldwell-Luc) approach. One year later, a graft from the ilium was obtained and a sinus elevation was performed to allow the placement of dental implants. Three months later, the dental implants were placed, and they were all osseointegrated at the 9-month follow-up.

  4. Capillary wave formation on excited solder jet and fabrication of lead-free solder ball

    Institute of Scientific and Technical Information of China (English)

    ZHANG Shu-guang; HE Li-jun; ZHU Xue-xin; ZHANG Shao-ming; SHI Li-kai; XU Jun

    2005-01-01

    A survey of solder ball production processes especially focusing on disturbed molten metal jet breakup process was made. Then the formation of capillary wave on tin melt jet in the way of rapid solidification was studied. A semi-empirical formula, which can be written as λ = Cvib (σ/ρ)1/3f-2/3 to predict the relationship between wavelength of capillary wave and frequency of imposed vibration was obtained. Sn-4.0Ag-0.5Cu lead free solder ball was successfully produced with tight distribution and good sphericity. The excited jet breakup process is promising for cost effectively producing solder ball.

  5. Effect of ultrasonic power and bonding force on the bonding strength of copper ball bonds

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Copper wire, serving as a cost-saving alternative to gold wire, has been used in many high-end thermosonic ball bonding applications. In this paper, the bond shear force, bond shear strength, and the ball bond diameter are adopted to evaluate the bonding quality. It is concluded that the efficient ultrasonic power is needed to soften the ball to form the copper bonds with high bonding strength. However, excessive ultrasonic power would serve as a fatigue loading to weaken the bonding. Excessive or less bonding force would cause cratering in the silicon.

  6. 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.

  7. A CAD CAM method for custom below-knee sockets.

    Science.gov (United States)

    Engsberg, J R; Clynch, G S; Lee, A G; Allan, J S; Harder, J A

    1992-12-01

    The purpose of this investigation was to develop a numerical method for fabricating prosthetic sockets for below-knee amputees. An optical/laser digitiser scans an amputee's stump and collects three dimensional numerical data describing the surface of the limb and describing specific modification site locations. The numerical data from the laser camera representing the stump and modification sites are altered by the prosthetist using a custom computer aided design software system running on a personal computer. Using the altered numerical data a programme is created for a high resolution numerically controlled milling machine and a mould is made. The prosthetist then fabricates a socket. While the system has been tested with below-knee amputees it has been designed for application in most areas of prosthetics and orthotics. Utilising this method 15 patients were fitted. All patients subjectively stated that their "computer designed" socket fitted better than their conventionally made socket. As the research progressed and experience was gained with the system patients were normally fitted with the first socket iteration. The system overcomes five limitations existing with some of the other numerical systems: 1) accurate high resolution surface topography, 2) specific identification of subject modification sites, 3) flexible, user friendly software, 4) high resolution numerically controlled milling, and 5) integrated expansion to other prosthetic and orthotic areas.

  8. 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.

  9. The Mathematics of Bouncing Balls.

    Science.gov (United States)

    Martin, Kathleen

    1989-01-01

    Describes an activity which uses the computer to produce an environment that encourages an inductive reasoning approach to ratio and proportion through a billiard ball simulation. Provides examples of graphs and bouncing ball data. (RT)

  10. 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

  11. 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.

  12. 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.

  13. Variability in clubhead presentation characteristics and ball impact location for golfers' drives.

    Science.gov (United States)

    Betzler, Nils F; Monk, Stuart A; Wallace, Eric S; Otto, Steve R

    2012-01-01

    The purpose of the present study was to analyse the variability in clubhead presentation to the ball and the resulting ball impact location on the club face for a range of golfers of different ability. A total of 285 male and female participants hit multiple shots using one of four proprietary drivers. Self-reported handicap was used to quantify a participant's golfing ability. A bespoke motion capture system and user-written algorithms was used to track the clubhead just before and at impact, measuring clubhead speed, clubhead orientation, and impact location. A Doppler radar was used to measure golf ball speed. Generally, golfers of higher skill (lower handicap) generated increased clubhead speed and increased efficiency (ratio of ball speed to clubhead speed). Non-parametric statistical tests showed that low-handicap golfers exhibit significantly lower variability from shot to shot in clubhead speed, efficiency, impact location, attack angle, club path, and face angle compared with high-handicap golfers.

  14. 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.

  15. Processing Defect Analysis and Nondestructive Evaluation Technology for Si3N4 Bearing Ball

    Institute of Scientific and Technical Information of China (English)

    YANG Tie-bin; WANG Li-qin; GU Le; ZHENG De-zhi

    2008-01-01

    Researches on the processing method of ceramic bearing ball, the formation and propagation of defects in the manufacturing and the nondestructive evaluation (NDE) are summarized in this paper. The key for successful processing of high strength ceramic balls is to avoid producing related defects. Many investigations show that the material microstruc-tures, defects as well as mechanical processing parameters influence the final surface quality significantly. Most of NDE technologies, such as radiation, ultrasonic, dye-penetration and laser scatter, have been studied for ceramic bearing ball surface inspection around the world. So far, the difficulties to develop the perfect NDE system for ceramic beating balls, which are caused by the defect variety and surface unfolding, have not been overcome yet.

  16. 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

  17. 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.

  18. 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.

  19. Invariant Mean-Value Property and M-Harmonicity in the Unit Ball of Rn

    Institute of Scientific and Technical Information of China (English)

    Cong Wen LIU; Ji Huai SHI

    2003-01-01

    In 1993, Ahern, Flores and Rudin showed that, if f is integrable over the unit ball BnC ofCn and satisfies ∫Bnc foψdv=f(ψ(0)) for every ψ∈ Aut(BnC), then f is M-harmonic if and only if n ≤ 11. The present paper is about ananalogous question in the context of the unit ball Bn of Rn as well as in the weighted setting.

  20. 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

  1. Comparison of Ball-And-Racket Impact Force in Two-Handed Backhand Stroke Stances for Different-Skill-Level Tennis Players.

    Science.gov (United States)

    Lo, Kuo-Cheng; Hsieh, Yung-Chun

    2016-06-01

    This study compared the kinetic roles of the upper extremities in racket impact force generation between the open stance (OS) and square stance (SS) for tennis players with different skill levels in two-handed backhand strokes. Twelve male tennis players were divided into an advanced group (AG) (L3-L2 skill level) and intermediate group (IG) (L7-L6 skill level), and their data were used in a three-dimensional kinetic analysis. Their motions were captured using 21 reflective markers attached to anatomic landmarks for two-handed backhand stroke motion data collection. During the acceleration phase, significant differences were not observed between both stances, but they were observed between the groups with different skill levels for the force of the upper extremities (p = 0.027). The joint forces were significantly lower in the AG than in the IG. Players performing the SS had significantly larger pronation and supination of the wrist joint moment than those in the OS (p = 0.032) during the acceleration phase, irrespective of the playing level. Higher internal rotation moment after impact was observed at each joint, particularly among young intermediate tennis players, regardless of their stance. The AG demonstrated a higher joint force and moment at every joint compared with the IG at impact. Moreover, the AG demonstrated superior stroke efficiency and effectively reduced joint moment after impact and sports injury. Key pointsAdvanced players, regardless of open stance or square stance, have larger joint force and moment at each joint before ball impact resulting in better stroke efficiency and reduced chance of injury.Intermediate players, regardless of stance, have higher internal rotation moment at each joint instead of larger joint force as compared to advanced players before ball impact. The higher internal rotation moment will induce higher joint impact force which makes the player injury-prone.Young intermediate tennis players may want to avoid excessive

  2. Orthogonal Polynomials on the Unit Ball and Fourth-Order Partial Differential Equations

    Science.gov (United States)

    Martínez, Clotilde; Piñar, Miguel A.

    2016-02-01

    The purpose of this work is to analyse a family of mutually orthogonal polynomials on the unit ball with respect to an inner product which includes an additional term on the sphere. First, we will get connection formulas relating classical multivariate orthogonal polynomials on the ball with our family of orthogonal polynomials. Then, using the representation of these polynomials in terms of spherical harmonics, algebraic and differential properties will be deduced.

  3. Detection of micro solder balls using active thermography and probabilistic neural network

    Science.gov (United States)

    He, Zhenzhi; Wei, Li; Shao, Minghui; Lu, Xingning

    2017-03-01

    Micro solder ball/bump has been widely used in electronic packaging. It has been challenging to inspect these structures as the solder balls/bumps are often embedded between the component and substrates, especially in flip-chip packaging. In this paper, a detection method for micro solder ball/bump based on the active thermography and the probabilistic neural network is investigated. A VH680 infrared imager is used to capture the thermal image of the test vehicle, SFA10 packages. The temperature curves are processed using moving average technique to remove the peak noise. And the principal component analysis (PCA) is adopted to reconstruct the thermal images. The missed solder balls can be recognized explicitly in the second principal component image. Probabilistic neural network (PNN) is then established to identify the defective bump intelligently. The hot spots corresponding to the solder balls are segmented from the PCA reconstructed image, and statistic parameters are calculated. To characterize the thermal properties of solder bump quantitatively, three representative features are selected and used as the input vector in PNN clustering. The results show that the actual outputs and the expected outputs are consistent in identification of the missed solder balls, and all the bumps were recognized accurately, which demonstrates the viability of the PNN in effective defect inspection in high-density microelectronic packaging.

  4. Onset of chaotic dynamics in a ball mill: Attractors merging and crisis induced intermittency

    Science.gov (United States)

    Manai, G.; Delogu, F.; Rustici, M.

    2002-09-01

    In mechanical treatment carried out by ball milling, powder particles are subjected to repeated high-energy mechanical loads which induce heavy plastic deformations together with fracturing and cold-welding events. Owing to the continuous defect accumulation and interface renewal, both structural and chemical transformations occur. The nature and the rate of such transformations have been shown to depend on variables, such as impact velocity and collision frequency that depend, in turn, on the whole dynamics of the system. The characterization of the ball dynamics under different impact conditions is then to be considered a necessary step in order to gain a satisfactory control of the experimental set up. In this paper we investigate the motion of a ball in a milling device. Since the ball motion is governed by impulsive forces acting during each collision, no analytical expression for the complete ball trajectory can be obtained. In addition, mechanical systems exhibiting impacts are strongly nonlinear due to sudden changes of velocities at the instant of impact. Many different types of periodic and chaotic impact motions exist indeed even for simple systems with external periodic excitation forces. We present results of the analysis on the ball trajectory, obtained from a suitable numerical model, under growing degree of impact elasticity. A route to high dimensional chaos is obtained. Crisis and attractors merging are also found.

  5. Influence of malalignment on socket reaction moments during gait in amputees with transtibial prostheses.

    Science.gov (United States)

    Boone, David A; Kobayashi, Toshiki; Chou, Teri G; Arabian, Adam K; Coleman, Kim L; Orendurff, Michael S; Zhang, Ming

    2013-04-01

    Alignment - the process and measured orientation of the prosthetic socket relative to the foot - is important for proper function of a transtibial prosthesis. Prosthetic alignment is performed by prosthetists using visual gait observation and amputees' feedback. The aim of this study was to investigate the effect of transtibial prosthesis malalignment on the moments measured at the base of the socket: the socket reaction moments. Eleven subjects with transtibial amputation were recruited from the community. An instrumented prosthesis alignment component was used to measure socket reaction moments during ambulation under 17 alignment conditions, including nominally aligned using conventional clinical methods, and angle perturbations of 3° and 6° (flexion, extension, abduction, and adduction) and translation perturbations of 5mm and 10mm (anterior, posterior, lateral, and medial) referenced from the nominal alignment. Coronal alignment perturbations caused systematic changes in the coronal socket reaction moments. All angle and translation perturbations revealed statistically significant differences on coronal socket reaction moments compared to the nominal alignment at 30% and 75% of stance phase (Psocket reaction moments was not as responsive as that of the coronal perturbations. The sagittal angle and translation perturbations of the socket led to statistically significant changes in minimum moment, maximum moment, and moments at 45% of stance phase in the sagittal plane. Therefore, malalignment affected the socket reaction moments in amputees with transtibial prostheses.

  6. Literature review of the possible advantages of silicon liner socket use in trans-tibial prostheses

    NARCIS (Netherlands)

    Baars, ECT; Geertzen, JHB

    2005-01-01

    The silicon liner socket has been used in the trans-tibial prosthesis since the 1980s. Silicon liner sockets are sleeves of silicon material that are rolled onto the stump and fix the prosthesis to it. The producers of the liners propagate many advantages in their use i.e. better suspension of the p

  7. Characterization of PVC joints' behaviour during variable loading laboratory tests

    NARCIS (Netherlands)

    Arsénio, André Marques; Vreeburg, J.H.G.; Bouma, Freddie; Rietveld, J.C.

    2015-01-01

    With the objective of defining parameters that can be used to assess the condition of PVC joints in the field, more than two-hundred destructive tests were done in the laboratory. Two diameters (110 mm and 315 mm) of new PVC double-sockets were tested. The occurrence of leakage during water press

  8. 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 obj

  9. Plantar aponeurosis and internal architecture of the ball of the foot.

    Science.gov (United States)

    Bojsen-Moller, F; Flagstad, K E

    1976-07-01

    On the basis of its internal structure, the ball of the foot can be divided into three transverse areas, each with a different mechanical function: (1) an area proximal to the heads of the metatarsals in which the retinacula cutis are developed into a series of transverse bands, and in which the deep fibres of the plantar aponeurosis form ten sagittal septa connected to the deep transverse metatarsal ligament and through this the proximal phalanges of the toes, (2) an area below the heads of the metatarsals in which vertical fibres from the joint capsules and the sides of the fibrous flexor sheaths form a cushion below each metatarsal head, and in which fat bodies cover the digital nerves and vessels in their passage between the cushions, and (3) a distal area which comprises the interdigital web. The superficial fibres of the plantar aponeurosis are inserted into the skin of this distal area, and deep to them the plantar interdigital ligament forms a series of transverse lamellae connected to the proximal phalanges by a mooring ligament which arches from one fibrous flexor sheath to the next. When the metatarsophalangeal joints are extended, the fibres of the three areas are tensed and the skin is anchored firmly to the skeleton. The direction of the fibres in the distal and proximal area promotes the transfer of forces exerted on the skin during push-off and braking respectively, while the intermediate area is adapted to bear the weight of the body. A concentration of Pacinian corpuscles is found along the digital nerves in the weight-bearing area below the transverse metatarsal ligament. The nerves for the second, and especially for the third, interstice are close to or in contact with the sharp proximal edges of the sagittal septa.

  10. Bones and joints

    Energy Technology Data Exchange (ETDEWEB)

    Runge, M.

    1987-01-01

    This exercise book guides the student and the radiologist wishing to review his knowledge to rapid and correct analysis and interpretation of radiologic findings in bone and joint disorders. The first part of the volume demonstrates the radiologic findings without going into the clinical and pathological aspects. In the second part, the reader then learns to analyse and diagnose systematically the case examples by means of a complete description of the X-ray images. Contents: Introduction; iconography; commentary with corresponding schemata; references and subject index.

  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. Application of WebSocket in English test system

    Science.gov (United States)

    Wang, Xin; Ye, Yan; Qi, Jiahui; Wu, Min

    2017-03-01

    Due to http protocol restrictions, the traditional web real-time applications cannot push information from the server to the browser. Although it can be achieved through technical means, but there are obvious shortcomings. This paper introduces an English testing system design and development on server-side, which is based on the WebSocket protocol. Through the WebSocket, a bidirectional communication channel can be established between the browser and the server. It realizes the real-time communication in the English test system.

  13. A proposed model of the response of the anophthalmic socket to prosthetic eye wear and its application to the management of mucoid discharge.

    Science.gov (United States)

    Pine, Keith R; Sloan, Brian H; Jacobs, Robert J

    2013-08-01

    Mucoid discharge associated with prosthetic eye wear can be a distressing condition that affects the quality of life of people who have lost an eye. Discharge is the second highest concern of experienced prosthetic eye wearers after health of the companion eye and is prevalent in anophthalmic populations. Specific causes of mucoid discharge such as infections and environmental allergens are well understood, but non-specific causes are unknown and an evidence based protocol for managing non-specific discharge is lacking. Current management is based on prosthesis removal and cleaning, and professional re-polishing of the prosthesis. Tear protein deposits accumulate on prosthetic eyes. These deposits mediate the response of the socket to prosthetic eye wear and their influence (good and bad) is determined by differing cleaning regimes and standards of surface finish. This paper proposes a three-phase model that describes the response of the socket to prosthetic eye wear. The phases are: An initial period of wear of a new (or newly-polished) prosthesis when homeostasis is being established (or re-established) within the socket; a second period (equilibrium phase) where beneficial surface deposits have built up on the prosthesis and wear is safe and comfortable, and a third period (breakdown phase) where there is an increasing likelihood of harm from continued wear. The proposed model provides a rationale for a personal cleaning regime to manage non-specific mucoid discharge. Professional care of prosthetic eyes is also important for the management of discharge and evidence for effective surface finishing is reported in this study. Taken together, the proposed regimes for personal and professional care comprise a protocol for managing discharge associated with prosthetic eye wear. The protocol describes prosthetic eye cleaning methods and frequency, and suggests minimum standards for professional polishing. If confirmed, the protocol has the potential to resolve the

  14. Surface-gradient cross-linked polyethylene acetabular cups: oxidation resistance and wear against smooth and rough femoral balls.

    Science.gov (United States)

    Shen, Fu-Wen; McKellop, Harry

    2005-01-01

    Two methods were developed and evaluated for cross-linking the bearing surface of a polyethylene acetabular cup to a limited depth, in order to improve its resistance to wear without degrading the mechanical properties of the bulk of the component. In the first method, low-energy electron beams were used to cross-link only the bearing surface of the cups to a maximum depth of about 2 mm. The cups then were annealed at 100 degrees C in vacuum for 3 or 6 days to reduce the residual free radicals, and the resultant resistance to oxidation was compared by artificially aging the cups at 80 degrees C in air. Chemically cross-linked surface layers were produced by coating the bearing surfaces of the cups with a thin layer of polyethylene powder mixed with 1% weight peroxide, and compressing them at 6.9 MPa (1000 psi) and 170 degrees C. This resulted in a cross-linked surface layer that extended about 3 mm deep, with a gradual transition to conventional (noncross-linked) polyethylene in the bulk of the implant. In hip simulator wear tests with highly polished (implant quality) femoral balls, both types of surface cross-linking were found to improve markedly the wear resistance of the acetabular cups. In tests with roughened femoral balls, the wear rates were much higher and were comparable to those obtained with similarly roughened balls against noncross-linked polyethylene cups in a previous study, indicating that the full benefit of cross-linking may not be realized under conditions of severe third-body abrasion. Nevertheless, these results show a promising approach for optimizing the wear resistance and the bulk mechanical properties of polyethylene components in total joint arthroplasty.

  15. Compact Q-balls

    CERN Document Server

    Bazeia, D; Marques, M A; Menezes, R; da Rocha, R

    2016-01-01

    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.

  16. Lagrangian Dynamics of Open Multibody Systems with Generalized Holonomic and Nonholonomic Joints

    NARCIS (Netherlands)

    Duindam, Vincent; Stramigioli, Stefano

    2007-01-01

    Standard methods to model multibody systems are aimed at systems with configuration spaces isomorphic to Rn. This limitation leads to singularities and other artifacts in case the configuration space has a different topology, for example in the case of ball joints or a free-floating mechanism. This

  17. 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.

  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. 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.

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

    Directory of Open Access Journals (Sweden)

    Müller Carsten

    2015-12-01

    Full Text Available 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.

  1. 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

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

    Science.gov (United States)

    Müller, Carsten; Brandes, Mirko

    2015-12-22

    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.

  3. Visual monitoring of network devices based on socket and Web GIS%基于Socket及Web GIS的网络设备可视化监测

    Institute of Scientific and Technical Information of China (English)

    龚成莹; 李驰新; 权晓红

    2011-01-01

    基于Google Maps API for Flash/Flex、PHP以及Socket技术,根据网络设备的技术特点和地理分布特点,以Web GIS方式灵活地实现了网络设备在线状态检测、设备信息查询、拓扑动态监测、电子地图刷新等功能.介绍了设计思路,主要功能及实现方法.%Based on Google Maps API for Flash / Flex, PHP and Socket technology, according to the technical characterics of network devices and geographical distribution, this article implements a flexible Web GIS, achieves the situation of online network device testing, information for network device query, dynamic topology monitoring, electronic map refresh And other functions, describes the design of system, the main function and its implementation.

  4. 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

  5. The Contents of Ustiloxins A and B along with Their Distribution in Rice False Smut Balls

    Science.gov (United States)

    Wang, Xiaohan; Fu, Xiaoxiang; Lin, Fengke; Sun, Weibo; Meng, Jiajia; Wang, Ali; Lai, Daowan; Zhou, Ligang; Liu, Yang

    2016-01-01

    Ustiloxins are cyclopeptide mycotoxins isolated from rice false smut balls (FSBs), the ball-like colonies transformed from the individual grains through the filament infection by the fungal pathogen Villosiclava virens. There were no obvious relations between ustiloxin content and any of the collection areas, collection times, or average weight of each FSB. The rice false smut balls at early, middle, and late maturity stages were respectively divided into different parts (glume, chlamydospores, mycelia, and pseudoparenchyma). The highest content of ustiloxins A and B of rice FSBs was found at the early maturity stage. Both ustiloxins A and B were mainly distributed in the middle layer containing mycelia and immature chlamydospores of the FSBs. When the rice FSBs were at the early maturity stage, the total yield of ustiloxins A and B in the middle layer of each ball was 48.3 µg, which was 3.20-fold of the yield (15.1 µg) of the inner part of the ball. The rice FSBs at the early maturity stage are the appropriate materials for the production of ustiloxins A and B. PMID:27608042

  6. Self-dispersed crumpled graphene balls in oil for friction and wear reduction

    Science.gov (United States)

    Dou, Xuan; Koltonow, Andrew R.; He, Xingliang; Jang, Hee Dong; Wang, Qian; Chung, Yip-Wah; Huang, Jiaxing

    2016-01-01

    Ultrafine particles are often used as lubricant additives because they are capable of entering tribological contacts to reduce friction and protect surfaces from wear. They tend to be more stable than molecular additives under high thermal and mechanical stresses during rubbing. It is highly desirable for these particles to remain well dispersed in oil without relying on molecular ligands. Borrowing from the analogy that pieces of paper that are crumpled do not readily stick to each other (unlike flat sheets), we expect that ultrafine particles resembling miniaturized crumpled paper balls should self-disperse in oil and could act like nanoscale ball bearings to reduce friction and wear. Here we report the use of crumpled graphene balls as a high-performance additive that can significantly improve the lubrication properties of polyalphaolefin base oil. The tribological performance of crumpled graphene balls is only weakly dependent on their concentration in oil and readily exceeds that of other carbon additives such as graphite, reduced graphene oxide, and carbon black. Notably, polyalphaolefin base oil with only 0.01–0.1 wt % of crumpled graphene balls outperforms a fully formulated commercial lubricant in terms of friction and wear reduction. PMID:26811466

  7. Air flow patterns and noise analysis inside high speed angular contact ball bearings

    Institute of Scientific and Technical Information of China (English)

    翟强; 闫柯; 张优云; 朱永生; 王亚泰

    2015-01-01

    The vortex formed around the rolling ball and the high pressure region formed around the ball−raceway contact zone are the principle factors that barricades the lubricant entering the bearing cavity, and further causes improper lubrication. The investigation of the air phase flow inside the bearing cavity is essential for the optimization of the oil−air two-phase lubrication method. With the revolutionary reference frame describing the bearing motion, a highly precise air phase flow model inside the angular contact ball bearing cavity was build up. Comprehensive factors such as bearing revolution, ball rotation, and cage structure were considered to investigate the influences on the air phase flow and heat transfer efficiency. The aerodynamic noise was also analyzed. The result shows that the ball spinning leads to the pressure rise and uneven pressure distribution. The air phase velocity, pressure and cage heat transfer efficiency increase as the revolving speed increases. The operating noise is largely due to the impact of the high speed external flow on the bearing. When the center of the oil−air outlet fixes near the inner ring, the aerodynamic noise is reduced. The position near the inner ring on the bigger axial side is the ideal position to fix the lubricating device for the angular contact ball bearing.

  8. RadBall{sup TM} Technology Testing and MCNP Modeling of the Tungsten Collimator

    Energy Technology Data Exchange (ETDEWEB)

    Farfan, Eduardo B; Foley, Trevor Q; Coleman, J Rusty; Jannik, G Timothy; Holmes, Christopher J; Oldham, Mark; Adamovics, John; Stanley, Steven J, E-mail: Eduardo.Farfan@srnl.doe.go

    2010-11-01

    The UK's National Nuclear Laboratory (NNL) has developed a remote, non-electrical, radiation-mapping device known as RadBall{sup TM}, which can locate and quantify radioactive hazards within contaminated areas of the nuclear industry. RadBall{sup TM} consists of a colander-like outer shell that houses a radiation-sensitive polymer sphere. The outer shell works to collimate radiation sources and those areas of the polymer sphere that are exposed react, becoming increasingly more opaque, in proportion to the absorbed dose. The polymer sphere is imaged in an optical-CT scanner, which produces a high resolution 3D map of optical attenuation coefficients. Subsequent analysis of the optical attenuation matrix provides information on the spatial distribution of sources in a given area forming a 3D characterization of the area of interest. RadBall{sup TM} has no power requirements and can be positioned in tight or hard-to reach locations. The RadBall{sup TM} technology has been deployed in a number of technology trials in nuclear waste reprocessing plants at Sellafield in the UK and facilities of the Savannah River National Laboratory (SRNL). This study focuses on the RadBall{sup TM} testing and modeling accomplished at SRNL.

  9. Preparation and Characterization of Stainless Steel/TiC Nanocomposite Particles by Ball-milling Method

    Institute of Scientific and Technical Information of China (English)

    CHEN Wenyi; ZHOU Jian

    2009-01-01

    A stainless steel/10wt%TiC nanocomposite particles were prepared by high-energy ball-milling method using stainless steel, carbon and titanium as raw materials. The evolution of phase composition, microstructure and specific surface area of the stainless steel/TiC nanocomposite particles with increasing ball-milling time in the range of 0-100 h were investigated by XRD, SEM, TEM and BET techniques. The results showed that the stainless steel/TiC nano-composite particles were fabricated when the ball-milling time was longer than 20 h. However, the nanocomposite particles were soldered and agglomerated again when the ball-milling time was longer than 60 h. The microstructure of the composite particles transformed from lamellar structure to nanostructure during the repeated process of the cold welding and cracking. TEM image reveals clearly that the in-situ TiC nanoparticles with grain size of 3-8 nm are in the interior of the stainless steel/TiC nanocomposite particles obtained by ball-milling 100 h.

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

    Institute of Scientific and Technical Information of China (English)

    LI Zi-Cheng; YANG Guo-Hua

    2011-01-01

    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.

  11. 76 FR 15940 - Ball Bearings and Parts Thereof From France, Germany, Italy, Japan, and the United Kingdom...

    Science.gov (United States)

    2011-03-22

    ... International Trade Administration Ball Bearings and Parts Thereof From France, Germany, Italy, Japan, and the... and parts thereof from ] France, Germany, Italy, Japan, and the United Kingdom for the period May 1... thereof from France, Germany, Italy, Japan, and the United Kingdom. See Ball Bearings and Parts...

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

    OpenAIRE

    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...

  13. 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.

  14. Theory of ball lightning

    CERN Document Server

    Wu, H -C

    2014-01-01

    We present a comprehensive explanation on ball lightning, a luminous sphere occasionally witnessed after ordinary lightning. In the last decade, it has been well established that natural lightning routinely generates relativistic electrons, which account for observed x rays. So we assume that, in a ball lightning event, a well-defined relativistic electron bunch is produced by the stepped leader of lightning. When this electron bunch strikes various media, a powerful microwave pulse is emitted by the coherent transition radiation mechanism. This intense microwave ionizes air, evacuates plasmas by its radiation pressure to form a globular plasma cavity, and then gets trapped inside the cavity. This theory successfully explains all characteristics of ball lightning, especially the appearance of ball lightning in fully-screened aircraft. Moreover, the proposed radiation mechanism fully explains the strongest radio signals from lightning and nanosecond spikes in the signals are direct evidences on the generation ...

  15. Development of Subischial Prosthetic Sockets with Vacuum-Assisted Suspension for Highly Active Persons with Transfemoral Amputations

    Science.gov (United States)

    2015-10-01

    comfort during sitting, standing, walking, and running in highly active transfemoral prosthesis users. The Specific Aims of this project are to: A1...with 3 lost to follow up (Table 1). Of the remaining 7 subjects, 6 have completed baseline biomechanics testing in their standard of care socket; 6/7...have completed baseline fluoroscopy testing in their standard of care socket; 3/7 have completed biomechanics testing in the sub-ischial socket (data

  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

    ... International Trade Administration Ball Bearings and Parts Thereof From Japan and the United Kingdom: Notice of... the United Kingdom, the Department of Commerce (the Department) revoked the Orders.\\1\\ On May 16, 2013... Value: Ball Bearings, and Cylindrical Roller Bearings and Parts Thereof From the United Kingdom, 54...

  17. 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

    ... From the Federal Register Online via the Government Publishing Office ] INTERNATIONAL TRADE COMMISSION Ball Bearings and Parts Thereof From France, Germany, and Italy; Termination of Five-Year Reviews... ball bearings and parts thereof from France, Germany, and Italy would be likely to lead to...

  18. Dimpled Ball Grid Array process development for space flight applications

    Science.gov (United States)

    Barr, S. L.; Mehta, A.

    2000-01-01

    The 472 Dimpled Ball Grid Array (D-BGA) package has not been used in past space flight environments, therefore it is necessary to determine the robustness and reliability of the solder joints. The 472 D-BGA packages passed the above environmental tests within the specifications and are now qualified for use on space flight electronics.

  19. 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.

  20. Vibrotactile evaluation: osseointegrated versus socket-suspended transfemoral prostheses.

    Science.gov (United States)

    Häggström, Eva; Hagberg, Kerstin; Rydevik, Björn; Brånemark, Rickard

    2013-01-01

    This study investigated detection thresholds of vibrometric stimuli in patients with transfemoral amputation supplied with osseointegrated (OI) and socket-suspended prostheses. It included 17 patients tested preoperatively with socket-suspended prostheses and after 2 yr with OI prostheses and a control group (n = 17) using socket-suspended prostheses, evaluated once. Assessments on the prosthetic and intact feet were conducted at six frequencies (8, 16, 32, 64, 125, and 250 Hz). Furthermore, measurements were conducted to investigate how vibrometric signals are transmitted through a test prosthesis. The results showed that the OI group had improved ability to detect vibrations through the prosthesis at 125 Hz (p = 0.01) at follow-up compared with the preoperative measurement. Compared with the control group, the OI group at follow-up had better ability to detect high frequency vibrations through the prosthesis (125 Hz, p = 0.02; 250 Hz, p = 0.03). The vibrometric signal transmitted through the test prosthesis was reduced at 8, 125, and 250 Hz but was amplified at 16, 32, and 64 Hz. Differences between the OI and the control groups were found in the highest frequencies in which the test prosthesis showed reduction of the vibrometric signal. The study provides insight into the mechanisms of vibration transmission between the exterior and bone-anchored as well as socket-suspended amputation prostheses.

  1. Vibrotactile evaluation: Osseointegrated versus socket-suspended transfemoral prostheses

    Directory of Open Access Journals (Sweden)

    Eva Häggström, CPO

    2014-02-01

    Full Text Available This study investigated detection thresholds of vibrometric stimuli in patients with transfemoral amputation supplied with osseointegrated (OI and socket-suspended prostheses. It included 17 patients tested preoperatively with socket-suspended prostheses and after 2 yr with OI prostheses and a control group (n = 17 using socket-suspended prostheses, evaluated once. Assessments on the prosthetic and intact feet were conducted at six frequencies (8, 16, 32, 64, 125, and 250 Hz. Furthermore, measurements were conducted to investigate how vibrometric signals are transmitted through a test prosthesis. The results showed that the OI group had improved ability to detect vibrations through the prosthesis at 125 Hz (p = 0.01 at follow-up compared with the preoperative measurement. Compared with the control group, the OI group at follow-up had better ability to detect high frequency vibrations through the prosthesis (125 Hz, p = 0.02; 250 Hz, p = 0.03. The vibrometric signal transmitted through the test prosthesis was reduced at 8, 125, and 250 Hz but was amplified at 16, 32, and 64 Hz. Differences between the OI and the control groups were found in the highest frequencies in which the test prosthesis showed reduction of the vibrometric signal. The study provides insight into the mechanisms of vibration transmission between the exterior and bone-anchored as well as socket-suspended amputation prostheses.

  2. Techniques for Interface Stress Measurements within Prosthetic Sockets of Transtibial Amputees: A Review of the Past 50 Years of Research.

    Science.gov (United States)

    Al-Fakih, Ebrahim A; Abu Osman, Noor Azuan; Mahmad Adikan, Faisal Rafiq

    2016-07-20

    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.

  3. 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.

  4. 76 FR 22372 - Ball Bearings and Parts Thereof From France, Germany, Italy, Japan, and the United Kingdom...

    Science.gov (United States)

    2011-04-21

    ... International Trade Administration Ball Bearings and Parts Thereof From France, Germany, Italy, Japan, and the... administrative reviews of the antidumping duty orders on ball bearings and parts thereof from France, Germany... Germany. We invite interested parties to comment on these preliminary results. Parties who submit...

  5. 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

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF COMMERCE International Trade Administration Ball Bearings and Parts Thereof From France, Germany, and Italy: Extension of... reviews of the antidumping duty orders on ball bearings and parts thereof from France, Germany,...

  6. Aerodynamics of sports balls

    Science.gov (United States)

    Mehta, R. D.

    1985-01-01

    Research data on the aerodynamic behavior of baseballs and cricket and golf balls are summarized. Cricket balls and baseballs are roughly the same size and mass but have different stitch patterns. Both are thrown to follow paths that avoid a batter's swing, paths that can curve if aerodynamic forces on the balls' surfaces are asymmetric. Smoke tracer wind tunnel tests and pressure taps have revealed that the unbalanced side forces are induced by tripping the boundary layer on the seam side and producing turbulence. More particularly, the greater pressures are perpendicular to the seam plane and only appear when the balls travel at velocities high enough so that the roughness length matches the seam heigh. The side forces, once tripped, will increase with spin velocity up to a cut-off point. The enhanced lift coefficient is produced by the Magnus effect. The more complex stitching on a baseball permits greater variations in the flight path curve and, in the case of a knuckleball, the unsteady flow effects. For golf balls, the dimples trip the boundary layer and the high spin rate produces a lift coefficient maximum of 0.5, compared to a baseball's maximum of 0.3. Thus, a golf ball travels far enough for gravitational forces to become important.

  7. 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.

  8. 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

  9. 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.

  10. New Revelation of Lightning Ball Observation and Proposal for a Nuclear Reactor Fusion Experiment

    CERN Document Server

    Tar, Domokos

    2009-01-01

    In this paper, the author brings further details regarding his Lightning Ball observation that were not mentioned in the first one (Ref.1-2). Additionally, he goes more into detail as the three forces that are necessary to allow the residual crescent form the hydrodynamic vortex ring to shrink into a sphere.Further topics are the similarities and analogies between the Lightning Ball formation's theory and the presently undertaken Tokamak-Stellarator-Spheromak fusion reactor experiments. A new theory and its experimental realisation are proposed as to make the shrinking of the hot plasma of reactors into a ball possible by means of the so called long range electromagnetic forces. In this way,the fusion ignition temperature could possibly atteined.

  11. Research on the Internationalization Trend for the Development of Worldwide Competitive Ball Games and Our Countermeasures

    Institute of Scientific and Technical Information of China (English)

    Yixin Ma

    2015-01-01

    With the progress of physical and sports industry in the world, the analysis of sport industry in China is greatly needed. In this paper, we take discussion the internationalization trend for the development of worldwide competitive ball games and our countermeasures. With the acceleration of global economic integration the frequent personnel exchanges between different countries and nations, nationalities has change.. Physical exercise is beneficial for enhancing national constitution and physique in China, and achieving higher level of national constitution and competitive application in China. Through the proposed research, we could obtain positive development of Chinese competitive ball ~ames' development and harvest.

  12. Characterisation of dynamic couplings at lower limb residuum/socket interface using 3D motion capture.

    Science.gov (United States)

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

    2015-12-01

    Design and fitting of artificial limbs to lower limb amputees are largely based on the subjective judgement of the prosthetist. Understanding the science of three-dimensional (3D) dynamic coupling at the residuum/socket interface could potentially aid the design and fitting of the socket. A new method has been developed to characterise the 3D dynamic coupling at the residuum/socket interface using 3D motion capture based on a single case study of a trans-femoral amputee. The new model incorporated a Virtual Residuum Segment (VRS) and a Socket Segment (SS) which combined to form the residuum/socket interface. Angular and axial couplings between the two segments were subsequently determined. Results indicated a non-rigid angular coupling in excess of 10° in the quasi-sagittal plane and an axial coupling of between 21 and 35 mm. The corresponding angular couplings of less than 4° and 2° were estimated in the quasi-coronal and quasi-transverse plane, respectively. We propose that the combined experimental and analytical approach adopted in this case study could aid the iterative socket fitting process and could potentially lead to a new socket design.

  13. Microstructure Evolution of Ti/BN Powder Blend during Ball Milling and Heat Treatment

    Institute of Scientific and Technical Information of China (English)

    Jianlin LI; Keao HU; Yong ZHONG

    2001-01-01

    Ball milled Ti/BN composite powder was prepared by high energy ball milling for 40 h, using Ti and BN (the molar ratio of Ti/BN is 3:2) as starting materials. The as-milled composite powder consists of TiN, Ti and amorphous phase. TiN formed while the milled powder was annealed at 400℃. The heat treatment at 700℃ led to the formation of TiB2 and TiB. The nanocrystalline Ti and amorphous phase converted to TiN and TiB2 when the powder was heated to 1300℃.

  14. Systematic review of effects of current transtibial prosthetic socket designs—Part 2: Quantitative outcomes

    Directory of Open Access Journals (Sweden)

    Mohammad Reza Safari, PhD

    2016-09-01

    Full Text Available This review is an attempt to untangle the complexity of transtibial prosthetic socket fit and perhaps find some indication of whether a particular prosthetic socket type might be best for a given situation. In addition, we identified knowledge gaps, thus providing direction for possible future research. We followed the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, using medical subject headings and standard key words to search for articles in relevant databases. No restrictions were made on study design and type of outcome measure used. From the obtained search results (n = 1,863, 35 articles were included. The relevant data were entered into a predefined data form that included the Downs and Black risk of bias assessment checklist. This article presents the results from the systematic review of the quantitative outcomes (n = 27 articles. Trends indicate that vacuum-assisted suction sockets improve gait symmetry, volume control, and residual limb health more than other socket designs. Hydrostatic sockets seem to create less inconsistent socket fittings, reducing a problem that greatly influences outcome measures. Knowledge gaps exist in the understanding of clinically meaningful changes in socket fit and its effect on biomechanical outcomes. Further, safe and comfortable pressure thresholds under various conditions should be determined through a systematic approach.

  15. Systematic review of effects of current transtibial prosthetic socket designs--Part 2: Quantitative outcomes.

    Science.gov (United States)

    Safari, Mohammad Reza; Meier, Margrit Regula

    2015-01-01

    This review is an attempt to untangle the complexity of transtibial prosthetic socket fit and perhaps find some indication of whether a particular prosthetic socket type might be best for a given situation. In addition, we identified knowledge gaps, thus providing direction for possible future research. We followed the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines, using medical subject headings and standard key words to search for articles in relevant databases. No restrictions were made on study design and type of outcome measure used. From the obtained search results (n = 1,863), 35 articles were included. The relevant data were entered into a predefined data form that included the Downs and Black risk of bias assessment checklist. This article presents the results from the systematic review of the quantitative outcomes (n = 27 articles). Trends indicate that vacuum-assisted suction sockets improve gait symmetry, volume control, and residual limb health more than other socket designs. Hydrostatic sockets seem to create less inconsistent socket fittings, reducing a problem that greatly influences outcome measures. Knowledge gaps exist in the understanding of clinically meaningful changes in socket fit and its effect on biomechanical outcomes. Further, safe and comfortable pressure thresholds under various conditions should be determined through a systematic approach.

  16. Titania Prepared by Ball Milling: Its Characterization and Application as Liquefied Petroleum Gas Sensor

    CERN Document Server

    Yadav, B C; Singh, Satyendra; Yadav, T P

    2012-01-01

    Present paper reports the LPG sensing of TiO2 obtained through ball milling. The milled powder was characterized by XRD, TEM and UV-visible spectroscopy. Further the ball milled powder was compressed in to pellet using hydraulic press. This pellet was investigated with the exposure of LPG. Variations in resistance with exposure of LPG to the sensing pellet were recorded. The sensitivity of the sensor was ~ 11 for 5 vol.% of LPG. Response and recovery times of the sensor were ~ 100 and 250 sec. The sensor was quite sensitive to LPG and results were found reproducible within 91%.

  17. Scientific validation of two commercial pressure sensor systems for prosthetic socket fit.

    Science.gov (United States)

    Polliack, A A; Sieh, R C; Craig, D D; Landsberger, S; McNeil, D R; Ayyappa, E

    2000-04-01

    The concept of measuring pressure at the interface between the stump and the prosthetic socket could provide valuable information in the process of prosthetic socket fabrication, modification, and fit. Two systems, the Rincoe Socket Fitting System (SFS) and Tekscan's F-Socket Pressure Measurement System, have been commercially designed for in situ interface pressure measurement over the past decade. Their use is not common in prosthetic practice, perhaps due to questions of cost effectiveness and the difficulties of interpreting the data. Another concern is the use of sensors for pressure measurements in areas of high contour and complex geometries such as the stump. Before these systems can be used in a clinical setting, it is necessary to determine the reliability and accuracy of each system. In order to assess the clinical validity of the Rincoe SFS and F-Socket systems, a series of trials was conducted to evaluate different aspects of sensor performance, namely; accuracy, hysteresis, drift and the effect of curvature. The sensors were subjected to tests in flatbed and custom-designed pressure vessels. Overall results indicated an accuracy error for the Rincoe SFS system of 25% (flatbed) and 33% (mould), with a corresponding 15% (flatbed) and 23% (mould) error in hysteresis, and 7% (flatbed) and 11% (mould) drift errors. The F-Socket system demonstrated an 8% (flatbed) and 11% (mould) accuracy errors, 42% (flatbed) and 24% (mould) hysteresis errors, and 12% (flatbed) and 33% (mould) drift errors. These findings indicate favourable results for the F-Socket Pressure Measurement System compared to the Rincoe Socket Fitting System with respect to its accuracy errors only. Nevertheless, it is the authors' belief that these systems are adequate in indicating areas of high pressure at the stump socket interface for clinical purposes, but both systems should be used with caution.

  18. Effect of ball milling and heat treatment process on MnBi powders magnetic properties

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Wei; Polikarpov, Evgueni; Choi, Jung-Pyung; Bowden, Mark E.; Sun, Kewei; Cui, Jun

    2016-09-01

    The metallic compound MnBi has high intrinsic coercivity with large positive temperature coefficient. The coercivity of MnBi exceeds 12 kOe and 26 kOe at 300 K and 523 K, respectively. Hence MnBi is a good candidate for the hard phase in exchange coupled nanocomposite magnets. In order to maximize the loading of the soft phase, the size of the MnBi particle has to be close to 500 nm, the size of single magnetic domain. Low energy milling is the common method to reduce MnBi particle size. However, only 3-7 mu m size particle can be achieved without significant decomposition. Here, we report our effort on preparing submicron MnBi powders using traditional powder metallurgy methods. Mn55Bi45 magnetic powders were prepared using arc melting method, followed by a series of thermal-mechanical treatment to improve purity, and finished with low energy ball milling at cryogenic temperature to achieve submicron particle size. The Mn55Bi45 powders were decomposed during ball milling process and recovered during 24 h 290 degrees C annealing process. With increasing ball-milling time, the saturation magnetization of MnBi decreases, while the coercivity increases. Annealing after ball milling recovers some of the magnetization, indicating the decomposition occurred during the ball-milling process can be reversed. The coercivity of Mn55Bi45 powders are also improved as a result of the heat treatment at 290 degrees C for 24 h. The world record magnetization 71.2 emu/g measured applying a field of 23 kOe has been achieved via low energy ball mill at room temperature

  19. Secondary reconstruction of severe contracted eye socket using modified ocular conformer-drainage tube system.

    Science.gov (United States)

    Li, Jin; Lin, Ming; Ge, Shengfang; Fan, Xianqun

    2012-07-01

    Eye socket reconstruction has been previously reported; however, few reports address reconstruction in cases of socket contracture after graft failure. This is a retrospective observational case study of 42 patients who had previously undergone eye socket reconstruction after posttraumatic enucleation owing to severe thermal or chemical injury, and each of whom presented with a severe contracted eye socket. Patients underwent free skin grafts and the placement of a modified ocular conformer-drainage tube system. Eye sockets of adequate size were created in the 42 patients. Three patients presented with gradual extrusion of the eye prosthesis due to recurrent contraction of the inferior fornix after treatment. These patients agreed to further operative procedures 6 months after secondary reconstruction surgery, which resulted in mild upward tilting of the eye prosthesis without extrusion. The prosthetic eyes fit well in all of the secondary reconstructed sockets using this technique. Our studies suggest that the modified ocular conformer-drainage tube system can efficiently control infection after secondary reconstruction of the posttraumatic contracted socket and may result in less shrinkage of skin grafts.

  20. Komposit Laminate Rami Epoksi Sebagai Bahan Alternatif Socket Prosthesis

    Directory of Open Access Journals (Sweden)

    Agustinus P. Irawan

    2009-01-01

    Full Text Available pure plant oil, biofuel, coconut oil, palm oil, jatropha oilSocket is the most important component in a prosthesis making. Performance criteria for prosthetic socket material include strength, durability, minimal weight, comfort, and minimal fabrication cost. This research attempts to analyze the strength of ramie fiber reinforced epoxy laminate composite as an alternative of socket prosthesis. The research based on ASTM D 3039/D 3039M for tensile strength and ASTM D 695 for compressive strength. The ramie fiber used was a continuous fiber 100 % Ne14'S, with Epoxy Resin Bakelite EPR 174 and Epoxy Hardener V-140. The sample test was created using a hand lay-up method. The result of this research is presented in a correlation of finsile strength (st, compression strength (sc, elasticity modulus (E versus fraction volume of fiber (Vf. The result is then being compared with some of the prosthesis material’s strength produced by Otto Bock. The analysis was completed with the mode of the failure observation by using Scanning Electron Microscope (SEM. The result concludes that the ramie fiber reinforced epoxy laminate composite is potentially developed further as a socket prosthesis material on Vf 40 – 50 %. Tensile strength and specific strength that has been generated was higher than that of several materias for socket prosthesis, including fiberglass. The mode of the failure found were a brittle failure on Vf: 10-30%, debonding and delamination on Vf: 40-50%. Abstract in Bahasa Indonesia: Socket merupakan bagian terpenting dalam pembuatan prosthesis. Kriteria bahan socket prosthesis antara lain kekuatan, ketahanan, ringan, kenyamanan dan biaya produksi yang rendah. Penelitian ini bertujuan menganalisis kekuatan komposit laminate berpenguat serat rami epoksi sebagai bahan alternatif socket prosthesis. Pengujian kekuatan mengacu standar ASTM D 3039/D 3039M uji tarik dan ASTM D 695 uji tekan. Serat rami yang digunakan berupa serat kontinyu jenis

  1. 基于低功耗蓝牙和WebSocket的物联网数据网关%Data Gateway B ased on Low Energy Bluetooth and WebSocket for Internet of Things

    Institute of Scientific and Technical Information of China (English)

    谢佳柏; 陈贤祥; 胡欣宇; 方震; 任仁; 夏善红

    2016-01-01

    To improve the compatibility of BluetoothL-ow-Energy(BLE)-based Internet of Things with mobile terminals such as mobile phones , tablet computers and laptop computers, a NI myRIO device and a CC 2540 BLE adapter were used to design a data gateway based on BLE and WebSocket , and its software architecture was made up of a WebSocket network layer , a main thread and a BLE driver.The data gateway can keep multiple connections with BLE sensor nodes and exchange data through Web -Socket with mobile terminals ,thus users can control the working conditions and receive the latest data of the sensors real -time via browser pages of the mobile terminals.The test results show that the data gateway can receive the sampling data of three BLE vibra -tion sensor nodes real-time and control the working parameters such as sampling channels and sampling rate of the sensors remote -ly.%为提高低功耗蓝牙( BLE)物联网对移动终端如手机、平板电脑和笔记本电脑的兼容性,文中利用NI myRIO设备和CC2540 BLE适配器设计了一款基于BLE和WebSocket 的数据网关,其软件架构包括WebSocket 网络层、主线程和BLE驱动,能同时连接多个BLE传感器节点并与移动终端通过WebSocket 进行数据交互,用户可在移动终端的浏览器页面控制传感器的工作状态并实时接收传感器采集的最新数据。测试结果表明该网关可实时接收3个BLE振动传感器节点的采样数据,并可远程控制传感器的采样通道、采样率等工作参数。

  2. THE SWISS BALL AND ITS USE IN PHYSICAL EDUCATION

    Directory of Open Access Journals (Sweden)

    Niculescu Ionela

    2009-06-01

    Full Text Available Each Physical Education lesson begins by warming-up, a phase when the exercises must be nice andhave to eliminate the tension accumulated during the other classes. The Swiss balloon actions allow us to noticethe manner in which our body is capable of working in all three plans (forward, backwards, lateral.Before beginning training, it is especially important that we very well know the Swiss balloonsexercises, for these not only solicit the great muscular groups, but also the deeper ones, not forgetting themuscles from around joints.The unstable surface of the Swiss balloon forces us to focus on the stabilizing muscles. If this condition is not fulfilled, we are not able to practice any exercise. Right before each particular execution, the muscles of the energy center must be contracted. (the area surrounding the basin, the back and the bottom.The balloon shapes are adapted to the natural curves of the backbone and through their unstable surface force the body to establish equilibrium and keep this state of balance, the moves being perfectly coordinated

  3. Study and implementation of Web real-time communication mechanism based on HTML5 WebSocket%基于HTML5 WebSocket的Web实时通信机制的研究与实现∗

    Institute of Scientific and Technical Information of China (English)

    陈丽枫; 郑力新; 王佳斌

    2016-01-01

    随着互联网技术的不断发展,Web技术在各个领域得到了不同程度的运用,人们对于Web应用的实时性提出了更高的要求,HTML5 WebSocket协议因此得到了广泛的关注。通过对基于HTTP的传统Web实时通信方案进行分析,针对其中的不足与缺点,深入介绍了基于HTML5 WebSocket协议的实时通信机制以及相对于传统方案的优势,并通过使用Node. js的Express框架和HTML5 WebSocket协议的第三方应用程序编程接口 Socket. io类库实现了一个基于WebSocket协议的Web应用。经实验表明,所描述的研究能成功地在客户端和服务器端完成基于HTML5 WebSocket协议的实时通信过程并建立连接。%With the development of Internet technology,Web technology has been applied in various fields , and people put forward higher re-quirements to the real-time of Web application. So HTML5 WebSocket protocol gets a lot of attention. Through the analysis of the traditional Web real-time communication scheme based on HTTP,for the deficiencies and disadvantages of HTTP, this paper introduces the real-time communication mechanism based on the HTML5 WebSocket protocol and the advantages compared with the traditional solutions. By using the Express framework of Node. js and third party application programming interface Socket. io library of HTML5 WebSocket protocol, it implements a Web application based on WeBsocket protocol. The experiment shows that it can successfully complete the process of real-time communication based on the HTML5 WebSocket protocol and establish a connection between the client and server.

  4. 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

    ... International Trade Administration Ball Bearings and Parts Thereof From Germany: Notice of Court Decision Not in... Germany. See SKF USA Inc., v. United States, Slip Op. 10-76 (CIT July 7, 2010). The Department is now... orders on ball bearings and parts thereof from France, Germany, Italy, Japan, and the United Kingdom...

  5. Effect of Ball Mass on Dribble, Pass, and Pass Reception in 9-11-Year-Old Boys' Basketball

    Science.gov (United States)

    Arias, Jose L.; Argudo, Francisco M.; Alonso, Jose I.

    2012-01-01

    The objective of the study was to analyze the effect of ball mass on dribble, pass, and pass reception in real game situations in 9-11-year-old boys' basketball. Participants were 54 boys identified from six federated teams. The independent variable was ball mass, and dependent variables were number of dribbles, passes, and pass receptions. Three…

  6. Drench Treatments for Management of Larval Japanese Beetle (Coleoptera: Scarabaeidae) in Field-Grown Balled and Burlapped Nursery Plants

    Science.gov (United States)

    The study evaluated insecticide drenches applied to post-harvest field-grown nursery plants harvested as 60-cm diameter balled and burlapped (B&B) root balls for controlling third instar Japanese beetle, Popillia japonica Newman. Bifenthrin, chlorpyrifos, lambda-cyhalothrin, and thiamethoxam were d...

  7. 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.

  8. TEMPOROMANDIBULAR-JOINT OSTEOARTHROSIS AND GENERALIZED JOINT HYPERMOBILITY

    NARCIS (Netherlands)

    DIJKSTRA, PU; DEBONT, LGM; STEGENGA, B; BOERING, G

    1992-01-01

    Peripheral joint mobility of temporomandibular joint (TMJ) osteoarthrosis and internal derangement patients (n = 25) and of a control group (n = 29) was measured according to a rigidly standardized protocol, in order to study the relationships between TMJ osteoarthrosis and internal derangement and

  9. 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.

  10. The Key Role of Ball Milling Time in the Microstructure and Mechanical Property of Ni-TiCNP Composites

    Science.gov (United States)

    Zhou, Xiaoling; Huang, Hefei; Xie, Ruobing; Yang, Chao; Li, Zhijun; Jiang, Li; Ye, Xiangxi; Xu, Hongjie

    2016-12-01

    Titanium carbide nanoparticle-reinforced nickel-based alloys (Ni-TiCNP composites) with ball milling time ranging from 8 to 72 h were prepared by ball milling and spark plasma sintering. Transmission electron microscopy (TEM) and scanning electron microscopy equipped with electron backscatter diffraction were used to characterize the microstructures. Their hardness and tensile properties were measured using the Vickers pyramid method and tensile tests. TEM results showed that a slight coarsening of TiCNP occurred during the ball milling process. The grain sizes of the Ni-TiCNP composites with various ball milling times were different, but they were all much smaller than those of the pure Ni. In all cases, the Ni-TiCNP composites showed higher strengths and hardness values than the unreinforced pure nickel. Furthermore, the strength of the Ni-TiCNP composites increased initially and then decreased as a function of ball milling time. The maximum strengths occurred in the 24-h ball milling sample, which presented the lowest average grain size. The Hall-Petch strengthening was suggested to be the main reason responsible for such variations in mechanical properties. Additionally, the elongation percentage of the Ni-TiCNP composites decreased gradually with ball milling time. This may be caused by the change of microvoids in the composite as the ball milling time varies, which is also related to their fracture behavior.

  11. 75 FR 30856 - Ball Bearings From Japan and the United Kingdom

    Science.gov (United States)

    2010-06-02

    ... and the United Kingdom AGENCY: United States International Trade Commission. ACTION: Notice of remand... antidumping orders on ball bearings from Japan and the United Kingdom. For further information concerning the... affirmative determination in Certain Bearings and Parts Thereof From Japan and the United Kingdom, Inv....

  12. 75 FR 62763 - Ball Bearings and Parts Thereof From Germany: Amended Final Results of Antidumping Duty...

    Science.gov (United States)

    2010-10-13

    ... International Trade Administration Ball Bearings and Parts Thereof From Germany: Amended Final Results of... bearings and parts thereof from Germany. See SKF USA Inc. v. United States, Slip Op. 10-76 (CIT 2010). The... bearings and parts thereof from Germany covering the period of review May 1, 2006, through April 30,...

  13. 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…

  14. Left atrial ball thrombus with acute mesenteric ischemia: Anesthetic management and role of transesophageal echocardiography

    Directory of Open Access Journals (Sweden)

    Neeti Makhija

    2014-01-01

    Full Text Available A 62 year old female with severe mitral stenosis, large left atrial ball thrombus and acute mesenteric ischemia emergently underwent mitral valve replacement, left atrial clot removal and emergency laparotomy for mesenteric ischemia. Peri-operative management issues, particularly, the anesthetic challenges and the role of transesophageal echocardiography are discussed.

  15. 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.

  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. Postural Control During Cascade Ball Juggling: Effects of Expertise and Base of Support.

    Science.gov (United States)

    Rodrigues, Sérgio T; Polastri, Paula F; Gotardi, Gisele C; Aguiar, Stefane A; Mesaros, Marcelo R; Pestana, Mayara B; Barbieri, Fabio A

    2016-08-01

    Cascade ball juggling is a complex perceptual motor skill which requires efficient postural stabilization. The aim of this study was to investigate effects of experience (expert and intermediate groups) and foot distance (wide and narrow stances) on body sway of jugglers during three ball cascade juggling. A total of 10 expert jugglers and 11 intermediate jugglers participated in this study. Participants stood barefoot on the force plate (some participants wore a gaze tracking system), with feet maintained in wide and narrow conditions and performed three 40-seconds trials of the three-ball juggling task. Dependent variables were sway mean velocity, amplitude, mean frequency, number of ball cycles, fixation number, mean duration and its variability, and area of gaze displacement. Two-way analyses of variance with factors for group and condition were conducted. Experts' body sway was characterized by lower velocity and smaller amplitude as compared to intermediate group. Interestingly, the more challenging (narrow) basis of support caused significant attenuation in body sway only for the intermediate group. These data suggest that expertise in cascade juggling was associated with refined postural control.

  18. 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…

  19. Nonconservation of Energy and Loss of Determinism I. Infinitely Many Colliding Balls

    NARCIS (Netherlands)

    Atkinson, David; Johnson, Porter

    2009-01-01

    An infinite number of elastically colliding balls is considered in a classical, and then in a relativistic setting. Energy and momentum are not necessarily conserved globally, even though each collision does separately conserve them. This result holds in particular when the total mass of all the bal

  20. Structural and magnetic stability of high energy ball milled Co{sub 2}MnSi

    Energy Technology Data Exchange (ETDEWEB)

    Vinesh, A., E-mail: attatappa85@gmail.com [Department of Physics, Amity School of Applied Sciences, Amity University Haryana, Gurgaon 122413 (India); Sudheesh, V.D. [Department of Physics, MohanlalSukhadia University Udaipur, Rajasthan 313001 (India); Sebastian, Varkey [Department of Physics, Nimalagiri College, Nirmalagiri, Kannur, Kerala 670701 (India); Lakshmi, N.; Venugopalan, K. [Department of Physics, MohanlalSukhadia University Udaipur, Rajasthan 313001 (India)

    2015-07-15

    Structural and magnetic properties of ball milled Co{sub 2}MnSi have been studied and compared with that of ordered bulk sample. The milled sample (with average size determined using the Williamson–Hall method) shows that the chemical ordering for this sample is very stable and is little effected by high energy ball milling. However, the reduction in the saturation magnetic moment of the milled sample shows that there is spin disordering induced on ball milling – attributable to the formation of a magnetically dead layer at the surface of the nano-sized samples. The ordered sample (unmilled) has a saturation moment value of 4.4 µ{sub B} per formula unit at room temperature and is in agreement with the prediction of Slater Pauling curve. On milling it reduces to ~3 µ{sub B} per formula unit at room temperature with an accompanying increase in the coercivity, retentivity and squareness factor. - Highlights: • We studied the magnetic and structural properties of bulk and ball milled Co{sub 2}MnSi. • Structural disordering is minimal even at 36 nm. • Constant value of T{sub C} shows strong ferromagnetic interaction in smaller particles. • Formation of magnetically dead surface layer results reduction in magnetic moment. • Variation of magnetic parameters is systematic with variation in milling time/size.

  1. Effects of operation temperature on thermal expansion and main parameters of radial ball bearings

    Directory of Open Access Journals (Sweden)

    Mitrović Radivoje M.

    2015-01-01

    Full Text Available The research of influence of operation temperature on the thermal expansion and main parameters of radial ball bearings is presented in this paper. The main bearing parameters are identified in accordance with the increasing requests concerning stability and load capacity. A series of Finite Element Analyses is performed for quasi-static analysis of all identified bearing parameters during contact period in referent temperature. Then, the dependence of bearing material characteristics on the operation temperature is discussed. Few series of Finite Element Analyses are performed for a particular radial ball bearing type, with characteristics in accordance with manufacturer specifications, for several operation temperatures. These two problems analyses include consideration of relation between the initial radial clearance, thermal expansion strains and contact deformations of the parts of the bearing assembly. The results for radial ball bearing parameters are monitored during a ball contact period for different temperatures and the appropriate discussion and conclusions are given. The conclusions about the contribution of developed procedure in defining the optimum operation temperature range are shown. [Projekat Ministarstva nauke Republike Srbije, br. TR 35029 i br. OI 174001

  2. Combination of Aloe vera and xenograft induction on decreasing of NF-kb of tooth extraction socket preservation in Cavia cobaya

    Directory of Open Access Journals (Sweden)

    Utari Kresnoadi

    2014-03-01

    Full Text Available Background: Tooth extraction can naturally cause inflammation triggering osteoclast proliferation and alveolar bone resorption. Preservation of the tooth extraction sockets is needed for patients in order to reduce alveolar bone resorption risks. Aloe vera is known to have anthraquinones components, namely Aloin, Aloe emedin, and barbaloin, considered as anti-inflammation. Therefore, to overcome the inflammation, the role of NF-kb is very significant to decrease nuclear factor kappa b (NF-kb. As a result, inflammation risks will be decreased. Purpose: The study was aimed to determine the induction effect of combination of Aloe vera and XCB into tooth extraction sockets to reduce inflammation by reducing NF-kb expression, osteoclasts and osteoblasts. Methods: Forty-eight Cavia cobaya were divided into eight groups, each group consisted of six animals. The mandibular incisors of those Cavia cobaya were extracted and induced with either PEG, XCB, Aloe vera, or the combination of Aloe vera + XCB. Those animals were sacrificed on day 7 and day 30 after the extraction. Then immunohistochemical and histopathology examinations were conducted to observe NF-kb expression, osteoblasts and osteoclasts. Results: It was known that in group induced with the combination of Aloe vera and xenograft concelous bovine, the growth of osteoblasts was high, while NF-kb expression and osteoclasts reduced. Conclusion: It can be concluded that the induction of the combination of Aloe vera and XCB into the tooth extraction sockets can reduce NF-kb expression and osteoclast, as a result, alveolar bone resorption risks decrease, and osteoblast increase.Latar belakang: Trauma mekanis akibat pencabutan gigi asli menyebabkan keradangan. Keradangan memicu proliferasi osteoklas sehingga menyebabkan resorpsi tulang alveolararis. Pada pembuatan gigi tiruan, resorpsi tulang alveolar yang terjadi, sangat tidak diinginkan, sebab resorpsi tulang alveolar mengurangi keberhasilan

  3. 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…

  4. Analytical and experimental investigation of the static friction regime for rubber-rigid ball contact

    NARCIS (Netherlands)

    Deladi, E.L.; Rooij, de M.B.; Vries, de E.G; Schipper, D.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 fri

  5. 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…

  6. 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.

  7. Effect of Number of Players and Maturity on Ball-Drills Training Load in Youth Basketball

    Directory of Open Access Journals (Sweden)

    Daniele Conte

    2017-01-01

    Full Text Available This study aimed to assess the basketball ball-drills workload analyzing: (1 the effect of varying the number of players involved on physiological and technical demands; (2 the temporal changes in players’ responses across bouts; and (3 the relationship of players’ workload with their maturation status and training age. Twelve young male basketball players (mean ± SD; age 13.9 ± 0.7 years; height 1.76 ± 0.06 m; body mass 65.7 ± 12.5 kg; HRmax 202 ± 8 beat·min−1 completed three bouts of 4 min interspersed by 2 min of passive recovery of two vs. two and four vs. four ball-drills. The mean percentage of HRmax (%HRmax and ratings of perceived exertion (RPE were collected. Technical actions (TAs (dribbles, passes, shots, interceptions, steals, rebounds, and turnovers were calculated through notational analysis. Players’ genitalia development (GD and pubic hair (PH growth were assessed using Tanner scale. Results showed a higher %HRmax (p = 0.018, RPE (p = 0.042, dribbles (p = 0.007, shots (p = 0.003, and rebounds (p = 0.006 in two vs. two compared to four vs. four condition. Furthermore, a statistical difference was found for %HRmax (p = 0.005 and number of passes (p = 0.020 between bouts. In addition, no correlation between GD, PH, and training age with %HRmax, RPE, and TAs was found. These findings suggest that variations of the number of players involved affect ball-drills workload and that ball-drills training intensity varies across bouts. Finally, ball-drills elicit an adequate training stimulus, regardless of players’ maturation status and training age.

  8. Evaluation and Description of Friction between an Electro-Deposited Coating and a Ceramic Ball under Fretting Condition

    Directory of Open Access Journals (Sweden)

    Kyungmok Kim

    2015-07-01

    Full Text Available This article describes fretting behavior of zirconia and silicon nitride balls on an electro-deposited coating. Fretting tests are performed using a ball-on-flat configuration. The evolution of the kinetic friction coefficient is determined, along with slip ratio. Experimental results show that the steady-state friction coefficient between ceramic balls (Si3N4 and ZrO2 and an electro-deposited coating is about 0.06, lower than the value between AISI 52100 ball and the coating. After a steady-state sliding, the transition of the friction coefficient is varied with a ball. The friction coefficient for ZrO2 balls became a critical value after higher fretting cycles than those for Si3N4 and AISI 52100 balls. In addition, it is identified that two parameters can describe the transition of the friction coefficient. Finally, the evolution of the friction coefficient is expressed as an exponential or a power-law form.

  9. 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...

  10. Interacting Q-balls

    CERN Document Server

    Brihaye, Yves

    2007-01-01

    We construct explicit examples of new axially symmetric, non-spinning Q-ball solutions that have not been studied so far. These solutions can be interpreted as angular excitations of the fundamental Q-balls and are related to the spherical harmonics. Correspondingly, they have higher energy and their energy densities possess two local maxima on the positive z-axis. We also study two Q-balls interacting via a potential term in 3+1 dimensions and construct examples of stationary, solitonic-like objects in (3+1)-dimensional flat space-time that consist of two interacting global scalar fields. We concentrate on configurations composed of one spinning and one non-spinning Q-ball and study the parameter-dependence of the energy and charges of the configuration. In addition, we present numerical evidence that for fixed values of the coupling constants two different types of 2-Q-ball solutions exist: solutions with defined parity, but also solutions which are asymmetric with respect to reflexion through the x-y-axis.

  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. Osteoarthritis of the Wrist STT Joint and Radiocarpal Joint.

    Science.gov (United States)

    Wollstein, Ronit; Clavijo, Julio; Gilula, Louis A

    2012-01-01

    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.

  13. WebSocket与MQTT在Web即时通信系统中的应用%Application of WebSocket and MQTT in Web Real-Time Communication System

    Institute of Scientific and Technical Information of China (English)

    刘峰; 陈朴; 贾军营

    2016-01-01

    传统Web通信系统多采用轮询拉取方式,此种方式存在实时性低、网络资源消耗大、扩展性差等缺点。针对上述问题,本文研究了WebSocket中的长连接技术,结合MQTT协议,提出了基于pub/sub模型的Web端即时通信解决方案,以推送取代传统拉取方式。文中重点阐述了 IM 与通知类消息格式设计,并针对通知类消息提出了 agent 代理模型,同时为了进一步减少网络资源消耗,提出了预订阅模式。最后将该解决方案与现流行的bosh+xmpp方式在时延、带宽消耗方面做了对比分析,以验证该方案的性能优势。%Polling pull strategy, which is widely used in traditional web communication system, has some problems, such as low real-time, heavy consumption of network resource and poor scalability. To solve these problems, much research about long connection technology in WebSocket has been done in the paper. Combining WebSocket with MQTT protocol, a new web instant messaging solution based on pub/sub model was proposed to replace polling strategy with push strategy. The formation design of IM and notification message was described in detail. And agent model was proposed for notification message. Meanwhile, a pre-subscription scheme was put forward to decrease net resource consumption further. Moreover, a comparative analysis on delay, bandwidth consumption between the solution and a current popular way bosh+xmpp was done to verify the advantages of the solution.

  14. Computer-Guided Implant Surgery in Fresh Extraction Sockets and Immediate Loading of a Full Arch Restoration: A 2-Year Follow-Up Study of 14 Consecutively Treated Patients

    OpenAIRE

    M. Daas; Assaf, A.; K. Dada; Makzoumé, J.

    2015-01-01

    Statement of Problem. Low scientific evidence is identified in the literature for combining implant placement in fresh extraction sockets with immediate function. Moreover, the few studies available on immediate implants in postextraction sites supporting immediate full-arch rehabilitation clearly lack comprehensive protocols. Purpose. The purpose of this study is to report outcomes of a comprehensive protocol using CAD-CAM technology for surgical planning and fabrication of a surgical templa...

  15. Anterior cruciate ligament femoral socket drilling with a retrograde reamer: lessons from the learning curve.

    Science.gov (United States)

    Ferraz, Victor; Westerberg, Paul; Brand, Jefferson C

    2013-01-01

    Whereas "anatomic" anterior cruciate ligament reconstruction may improve clinical results, the technique has introduced new technical challenges. The purpose of this technical note and video is to explore tips and tricks that improve femoral socket drilling with a retrograde reamer, bone-patellar tendon-bone graft passage, and interference screw fixation. The techniques for retrograde femoral socket drilling in an inside-out direction, bone-patellar tendon-bone graft passage, and interference screw fixation are described and demonstrated. Pitfalls, troubleshooting tips, and possible solutions are discussed. With the retrograde reamer, the femoral socket can be placed in the footprint of the anterior cruciate ligament with a longer and more vertical tunnel. By modifying the size of the patellar bone plug, graft passage is improved. With care and technique, interference screw fixation in the femoral socket over a guidewire is possible.

  16. Tunguska Dark Matter Ball

    CERN Document Server

    Froggatt, C D

    2014-01-01

    It is suggested that the Tunguska event in June 1908 cm-large was due to a cm-large ball of a condensate of bound states of 6 top and 6 anti-top quarks containing highly compressed ordinary matter. Such balls are supposed to make up the dark matter as we earlier proposed. The expected rate of impact of this kind of dark matter ball with the earth seems to crudely match a time scale of 200 years between the impacts. The main explosion of the Tunguska event is explained in our picture as material coming out from deep within the earth, where it has been heated and compressed by the ball penetrating to a depth of several thousand km. Thus the effect has some similarity with volcanic activity as suggested by Kundt. We discuss the possible identification of kimberlite pipes with earlier Tunguska-like events. A discussion of how the dark matter balls may have formed in the early universe is also given.

  17. 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...

  18. Dynamic Investigation of Interface Stress on Below-Knee Residual Limb in a Prosthetic Socket

    Institute of Scientific and Technical Information of China (English)

    贾晓红; 张明; 王人成; 金德闻

    2004-01-01

    The dynamic effects of inertial loads on the interface stresses between a residual limb and the trans-tibial prosthetic socket were investigated. A 3-D nonlinear finite element model, based on the actual geometry of the residual limb, including internal bones and socket liner, was developed to study the mechanical interaction between the socket and the residual limb during walking. To simulate the friction/slip boundary conditions between the skin and liner, automated surface-to-surface contact was used. The results show that interface pressure and shear stress have a similar double-peaked waveform shape in the stance phase. The average difference in interface stresses between the cases with and without consideration of inertial forces is 8.4% in the stance phase and 20.1% in the swing phase. The results suggest that the dynamic effects of inertial loads on interface stress distribution during walking must be considered in prosthetic socket design.

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

    OpenAIRE

    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 rad...

  20. State-of-the-art research in lower-limb prosthetic biomechanics-socket interface: a review.

    Science.gov (United States)

    Mak, A F; Zhang, M; Boone, D A

    2001-01-01

    Scientific studies have been conducted to quantify attributes that may be important in the creation of more functional and comfortable lower-limb prostheses. The prosthesis socket, a human-machine interface, has to be designed properly to achieve satisfactory load transmission, stability, and efficient control for mobility. The biomechanical understanding of the interaction between prosthetic socket and the residual limb is fundamental to such goals. The purpose of this paper is to review the recent research literature on socket biomechanics, including socket pressure measurement, friction-related phenomena and associated properties, computational modeling, and limb tissue responses to external mechanical loads and other physical conditions at the interface. There is no doubt that improved biomechanical understanding has advanced the science of socket fitting. However, the most recent advances in the understanding of stresses experienced at the residual limb have not yet led to enough clinical consensus that could fundamentally alter clinical practice. Efforts should be made to systematically identify the major discrepancies. Further research should be directed to address the critical controversies and the associated technical challenges. Developments should be guided to offer clinicians the quantification and visualization of the interaction between the residual limb and the prosthetic socket. An understanding of comfort and optimal load transfer as patterns of socket interface stress could culminate in socket design expert systems.

  1. Anterior Cruciate Ligament Femoral Socket Drilling With a Retrograde Reamer: Lessons From the Learning Curve

    OpenAIRE

    2013-01-01

    Whereas “anatomic” anterior cruciate ligament reconstruction may improve clinical results, the technique has introduced new technical challenges. The purpose of this technical note and video is to explore tips and tricks that improve femoral socket drilling with a retrograde reamer, bone–patellar tendon–bone graft passage, and interference screw fixation. The techniques for retrograde femoral socket drilling in an inside-out direction, bone–patellar tendon–bone graft passage, and interference...

  2. Joint probabilities and quantum cognition

    CERN Document Server

    de Barros, J Acacio

    2012-01-01

    In this paper we discuss the existence of joint probability distributions for quantum-like response computations in the brain. We do so by focusing on a contextual neural-oscillator model shown to reproduce the main features of behavioral stimulus-response theory. We then exhibit a simple example of contextual random variables not having a joint probability distribution, and describe how such variables can be obtained from neural oscillators, but not from a quantum observable algebra.

  3. A Randomized Case-Series Study Comparing the Stability of Implant with Two Different Surfaces Placed in Fresh Extraction Sockets and Immediately Loaded

    Directory of Open Access Journals (Sweden)

    Leonardo Vanden Bogaerde

    2016-01-01

    Full Text Available Background. Hydrophilic and moderately rough implant surfaces have been proposed to enhance the osseointegration response. Aim. The aim of this study was to compare early changes of stability for two implants with identical macrodesign but with different surface topographies. Materials and Methods. In 11 patients, a total of 22 implants (11 bimodal (minimally rough, control and 11 proactive (moderately rough and hydrophilic, test, Neoss Ltd., Harrogate, UK were immediately placed into fresh extraction sockets and immediately loaded. The peak insertion torque (IT was measured in Ncm at placement. Resonance Frequency Analysis (RFA measurements were made at baseline and 2, 4, 6, and 12 weeks after surgery. Results. The two implant types showed similar IT and RFA values at placement (NS. A dip of RFA values after 2 weeks followed by an increase was observed, where the test implant showed a less pronounced decrease and a more rapid recovery than the control implant. The test implants were significantly more stable than the control ones after 12 weeks. Conclusions. The results from the present study indicated that the hydrophilic and rougher test implant was more resistant to immediate loading and showed a significantly higher stability than the smoother control implant after 12 weeks.

  4. 基于Socket的医疗费用银行结算平台的设计%Hospital medical expenses and bank settlement platform based on Socket

    Institute of Scientific and Technical Information of China (English)

    刘兴淮; 朱健; 徐燕梅; 梁敏

    2012-01-01

    为了实现银行结算系统和医院信息系统之间的通信,构建一个跨行业、跨系统的新型结算平台,将Delphi多线程技术应用到同步阻塞型Socket编程中,采用TCP/IP协议进行通信,数据报文经加密后进行发送和接收.医院和银行间的数据能够实现高效、无差错发送和接收.提供了一种面向连接的可靠的数据传输方法,实现医院和银行的联网实时结算.%Abstract: Delphi multi-thread technology is applied to the synchronous blocking type Socket programming tr? Realize the rommunioalion between banking settlement system and hospital information system, and to implement a new cross-trade, cross-system settlement platform. TCP/IP protocol is used for communication, and packets are encrypted for transmission and reception. The packet can be transmitted and received with high effectiveness and accuracy between the hospital and the bank. It is a connection-oriented, reliable data transmission method, which can implement the network connection and real time settlement between the hospital and the hank.

  5. Influence of Leukocyte- and Platelet-Rich Fibrin (L-PRF) in the Healing of Simple Postextraction Sockets: A Split-Mouth Study.

    Science.gov (United States)

    Marenzi, Gaetano; Riccitiello, Francesco; Tia, Mariano; di Lauro, Alessandro; Sammartino, Gilberto

    2015-01-01

    The aim of this study was to evaluate the effects of leukocyte- and platelet-rich fibrin (L-PRF) on the pain and soft tissue healing after tooth extractions. Twenty-six patients (9 males and 17 females) were treated with multiple extractions (2 to 8), with a total of 108 extractions. This was an exploratory single blinded randomized clinical trial with a split-mouth design. The pain after the surgery was assessed in each patient by the VAS scale (1 to 10) at intervals of 24-48-72-96 hours. The soft tissue healing was clinically evaluated at 3, 7, 14, and 21 days after surgery by the same examiner surgeon, using the modified Healing Index (4 to 12). The mean value of postextraction pain was 3.2 ± 0.3 in the experimental sides and 4.1 ± 0.1 in the control sides. After 7 days from the extractions, the values of modified Healing Index in the experimental and control groups were, respectively, 4.8 ± 0.6 and 5.1 ± 0.9. The use of L-PRF in postextraction sockets filling can be proposed as a useful procedure in order to manage the postoperative pain and to promote the soft tissue healing process, reducing the early adverse effects of the inflammation.

  6. Influence of Leukocyte- and Platelet-Rich Fibrin (L-PRF in the Healing of Simple Postextraction Sockets: A Split-Mouth Study

    Directory of Open Access Journals (Sweden)

    Gaetano Marenzi

    2015-01-01

    Full Text Available The aim of this study was to evaluate the effects of leukocyte- and platelet-rich fibrin (L-PRF on the pain and soft tissue healing after tooth extractions. Twenty-six patients (9 males and 17 females were treated with multiple extractions (2 to 8, with a total of 108 extractions. This was an exploratory single blinded randomized clinical trial with a split-mouth design. The pain after the surgery was assessed in each patient by the VAS scale (1 to 10 at intervals of 24-48-72-96 hours. The soft tissue healing was clinically evaluated at 3, 7, 14, and 21 days after surgery by the same examiner surgeon, using the modified Healing Index (4 to 12. The mean value of postextraction pain was 3.2 ± 0.3 in the experimental sides and 4.1 ± 0.1 in the control sides. After 7 days from the extractions, the values of modified Healing Index in the experimental and control groups were, respectively, 4.8 ± 0.6 and 5.1 ± 0.9. The use of L-PRF in postextraction sockets filling can be proposed as a useful procedure in order to manage the postoperative pain and to promote the soft tissue healing process, reducing the early adverse effects of the inflammation.

  7. Experimental and Numerical Analysis of the Shear Behaviour of Cemented Concrete-Rock Joints

    Science.gov (United States)

    Tian, H. M.; Chen, W. Z.; Yang, D. S.; Yang, J. P.

    2015-01-01

    The shear behaviour of cemented concrete-rock joints is a key factor affecting the shear resistance of dam foundations, arch bridge foundations, rock socketed piles and rock bolts in rock engineering. This paper presents an experimental and numerical investigation of the shear behaviour of cemented concrete-rock joints by direct shear tests. In this study we focused on the bond strength of cemented concrete-rock joints, so limestone with smooth surfaces was used for samples preparation to reduce the roughness effect. The experimental results show that the shear strength of joints with good adhesion is strongly dependent on the bond strength of the cohesive interfaces when the applied normal stress is less than 6 MPa. In addition, the sudden and gradual bond failure processes of the cohesive interfaces were observed with an increase of the normal stress. A simple, yet realistic, model of cemented concrete-rock joint is proposed to simulate the observed behaviour, including elastic behaviour of the bond before peak shear stress and post-peak behaviour due to bond failure and friction increase. Finally, the parameters analysis and calibration of the proposed model are presented.

  8. 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.

  9. 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...

  10. Development of a residuum/socket interface simulator for lower limb prosthetics.

    Science.gov (United States)

    McGrath, Michael Paul; Gao, Jianliang; Tang, Jinghua; Laszczak, Piotr; Jiang, Liudi; Bader, Dan; Moser, David; Zahedi, Saeed

    2017-03-01

    Mechanical coupling at the interface between lower limb residua and prosthetic sockets plays an important role in assessing socket fitting and tissue health. However, most research lab-based lower limb prosthetic simulators to-date have implemented a rigid socket coupling. This study describes the fabrication and implementation of a lower limb residuum/socket interface simulator, designed to reproduce the forces and moments present during the key loading phases of amputee walking. An artificial residuum made with model bones encased in silicone was used, mimicking the compliant mechanical loading of a real residuum/socket interface. A 6-degree-of-freedom load cell measured the overall kinetics, having previously been incorporated into an amputee's prosthesis to collect reference data. The developed simulator was compared to a setup where a rigid pylon replaced the artificial residuum. A maximum uniaxial load of 850 N was applied, comparable to the peak vertical ground reaction force component during amputee walking. Load cell outputs from both pylon and residuum setups were compared. During weight acceptance, when including the artificial residuum, compression decreased by 10%, while during push off, sagittal bending and anterior-posterior shear showed a 25% increase and 34% decrease, respectively. Such notable difference by including a compliant residuum further highlighted the need for such an interface simulator. Subsequently, the simulator was adjusted to produce key load cell outputs briefly aligning with those from amputee walking. Force sensing resistors were deployed at load bearing anatomic locations on the residuum/socket interface to measure pressures and were compared to those cited in the literature for similar locations. The development of such a novel simulator provides an objective adjunct, using commonly available mechanical test machines. It could potentially be used to provide further insight into socket design, fit and the complex load

  11. TEMPOROMANDIBULAR-JOINT OSTEOARTHROSIS AND TEMPOROMANDIBULAR-JOINT HYPERMOBILITY

    NARCIS (Netherlands)

    DIJKSTRA, PU; DEBONT, LGM; DELEEUW, R; STEGENGA, B; BOERING, G

    1993-01-01

    For studying the relationship between condylar hypermobility of the temporomandibular joint (TMJ) and osteoarthrosis (OA), 13 patients with bilateral condylar hypermobility were evaluated clinically and radiographically, 30 years after non-surgical treatment. The evaluation included range of motion,

  12. 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.

  13. The use of a polycaprolactone-tricalcium phosphate scaffold for bone regeneration of tooth socket facial wall defects and simultaneous immediate dental implant placement in Macaca fascicularis.

    Science.gov (United States)

    Goh, Bee Tin; Chanchareonsook, Nattharee; Tideman, Henk; Teoh, Swee Hin; Chow, James Kwok Fai; Jansen, John A

    2014-05-01

    Bone regeneration and aesthetic outcomes may be compromised when immediate implants are placed at extraction sites with dehiscence defects. The aim of this study was to compare, in a monkey model, peri-implant bone regeneration and implant stability after immediate implant placement into tooth sockets with facial wall defects in two treatment groups. In eight control monkeys, the bony defect was reconstructed with autogenous particulate bone, whereas in 10 test monkeys a polycaprolactone-tricalcium phosphate (PCL-TCP) scaffold was used. The monkeys were sacrificed after 6 months and the specimens were analyzed by histology and histomorphometry. Better maintenance of facial bone contour was noted in the test group; however, bone regeneration was seen only at areas adjacent to a bony wall of the defect. The mean bone-to-implant contact was 27.6 ± 19.1% (control group) versus 6.8 ± 7.9% (test group). The mean bone area percentage was 11.8 ± 10.1% (control group) versus 6.8 ± 6.9% (test group). Implant survival was 100% at 6 months for both the groups. It was concluded that although the use of a PCL-TCP scaffold showed better maintenance of the alveolar contour as compared to autogenous particulate bone at 6 months, there was minimal bone regeneration within the defect.

  14. 75 FR 26920 - Ball Bearings and Parts Thereof from France, Germany, Italy, Japan, and the United Kingdom...

    Science.gov (United States)

    2010-05-13

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF COMMERCE International Trade Administration Ball Bearings and Parts Thereof from France, Germany, Italy, Japan, and the United Kingdom: Preliminary Results of Antidumping Duty Administrative Reviews, Preliminary Results...

  15. New Q-ball solutions in gauge-mediation, Affleck-Dine baryogenesis and gravitino dark matter

    Energy Technology Data Exchange (ETDEWEB)

    Doddato, Francesca; McDonald, John, E-mail: f.doddato@lancaster.ac.uk, E-mail: j.mcdonald@lancaster.ac.uk [Consortium for Fundamental Physics, Cosmology and Astroparticle Physics Group, University of Lancaster, Lancaster LA1 4YB (United Kingdom)

    2012-06-01

    Affleck-Dine (AD) baryogenesis along a d = 6 flat direction in gauge-mediated supersymmetry-breaking (GMSB) models can produce unstable Q-balls which naturally have field strength similar to the messenger scale. In this case a new kind of Q-ball is formed, intermediate between the gravity-mediated and gauge-mediated types. We study in detail these new Q-ball solutions, showing how their properties interpolate between standard gravity-mediated and gauge-mediated Q-balls as the AD field becomes larger than the messenger scale. It is shown that E/Q for the Q-balls can be greater than the nucleon mass but less than the MSSM-LSP mass, leading to Q-ball decay primarily to Standard Model fermions. More significantly, if E/Q is greater than the MSSM-LSP mass, decaying Q-balls can provide a natural source of non-thermal MSSM-LSPs, which can subsequently decay to gravitino dark matter without violating nucleosynthesis constraints. The model therefore provides a minimal scenario for baryogenesis and gravitino dark matter in the gauge-mediated MSSM, requiring no new fields.

  16. Systematic review of effects of current transtibial prosthetic socket designs—Part 1: Qualitative outcomes

    Directory of Open Access Journals (Sweden)

    Mohammad Reza Safari, PhD

    2015-09-01

    Full Text Available This review is an attempt to untangle the complexity of transtibial prosthetic socket fit, determine the most important characteristic for a successful fitting, and perhaps find some indication of whether a particular prosthetic socket type might be best for a given situation. Further, it is intended to provide directions for future research. We followed the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines and used medical subject headings and standard key words to search for articles in relevant databases. No restrictions were made on study design or type of outcome measure. From the obtained search results (n = 1,863, 35 articles were included. The relevant data were entered into a predefined data form that incorporated the Downs and Black risk of bias assessment checklist. Results for the qualitative outcomes (n = 19 articles are synthesized. Total surface bearing sockets lead to greater activity levels and satisfaction in active persons with amputation, those with a traumatic cause of amputation, and younger persons with amputation than patellar tendon bearing sockets. Evidence on vacuum-assisted suction and hydrostatic sockets is inadequate, and further studies are much needed. To improve the scientific basis for prescription, comparison of and correlation between mechanical properties of interface material, socket designs, user characteristics, and outcome measures should be conducted and reported in future studies.

  17. Systematic review of effects of current transtibial prosthetic socket designs-Part 1: Qualitative outcomes.

    Science.gov (United States)

    Safari, Mohammad Reza; Meier, Margrit Regula

    2015-01-01

    This review is an attempt to untangle the complexity of transtibial prosthetic socket fit, determine the most important characteristic for a successful fitting, and perhaps find some indication of whether a particular prosthetic socket type might be best for a given situation. Further, it is intended to provide directions for future research. We followed the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines and used medical subject headings and standard key words to search for articles in relevant databases. No restrictions were made on study design or type of outcome measure. From the obtained search results (n = 1,863), 35 articles were included. The relevant data were entered into a predefined data form that incorporated the Downs and Black risk of bias assessment checklist. Results for the qualitative outcomes (n = 19 articles) are synthesized. Total surface bearing sockets lead to greater activity levels and satisfaction in active persons with amputation, those with a traumatic cause of amputation, and younger persons with amputation than patellar tendon bearing sockets. Evidence on vacuum-assisted suction and hydrostatic sockets is inadequate, and further studies are much needed. To improve the scientific basis for prescription, comparison of and correlation between mechanical properties of interface material, socket designs, user characteristics, and outcome measures should be conducted and reported in future studies.

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

    Science.gov (United States)

    Stolle, Achim; Schmidt, Robert; Jacob, Katharina

    2014-01-01

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

  19. Surgical treatment about hollow eye socket after enucleation of eyeball and having orbital fracture under endoscope%眼眶骨折眼球摘除术后眼窝凹陷的鼻内镜下手术

    Institute of Scientific and Technical Information of China (English)

    李谊; 朱豫

    2012-01-01

    目的 探讨在鼻内镜下,高密度多聚乙烯(Medpor)植入板联合羟基磷灰石(HA)义眼座植入治疗眼眶骨折眼球摘除后眼窝凹陷的临床效果.方法 对眼眶骨折眼球缺失后眼窝凹陷的156例先行HA义眼座Ⅰ期或Ⅱ期植入,后根据眶骨缺损情况在鼻内镜引导下以Medpor植入板填充修补.结果 156例均获良好效果,可见双眼外观基本对称,上眶区饱满无凹陷,患侧眶缘连续,外形良好.Medpor植入板植入后对义眼座活动度有显著性影响.结论 Medpor植入板眼眶填充联合HA义眼座眶内植入治疗合并眼眶骨折的眼窝凹陷效果良好;尤其是在鼻内镜引导下手术,更能使骨折断端达到完美的结合,并能避免损伤周围正常组织.%Objective To evaluate the clinical effect of the reconstruction of orbital socket with Medpor implant plate for the treatment of hollow eye socket after enucleation of eyeball and orbital fracture under endoscope.Methods 156 cases with hollow eye socket and orbital fracture had been implanted primarily or secondarily with Hydroxyapatite (HA) prosthesis under endoscope.Medpor implant plate reconstruction had been done according to the defection of the orbital bone.Results The results of 156 cases were satisfied,Both sides of the orbit were symmetric on appearance.Superior orbit was full and no depression.The hollow degree of the implants was also symmetric with the other eye.The orbital rims of the affected eye were continuous and in good shape,During the implantation of Medpor implant plate,it would owing significant effect to the motility of HA prosthesis.Conclusion Medpor implant plate should be good material for substitution of the bone,which has good tissue compatability,easy for shape and vascularization and much more better than other materials.Orbital socket reconstration by prosthesis implantation with hydroxyapatite prosthesis combine with Medpor implant plate for the treatment of hollow eye socket and

  20. Split Q-balls

    Science.gov (United States)

    Bazeia, D.; Losano, L.; Marques, M. A.; Menezes, R.

    2017-02-01

    We investigate the presence of non-topological solutions of the Q-ball type in (1 , 1) spacetime dimensions. The model engenders the global U (1) symmetry and is of the k-field type, since it contains a new term, of the fourth-order power in the derivative of the complex scalar field. It supports analytical solution of the Q-ball type which is stable quantum mechanically. The new solution engenders an interesting behavior, with the charge and energy densities unveiling a splitting profile.

  1. Magnetic property and microstructure of single crystalline Nd2Fe14B ultrafine particles ball milled from HDDR powders

    Energy Technology Data Exchange (ETDEWEB)

    Li, WF; Hu, XC; Cui, BZ; Yang, JB; Han, JZ; Hadjipanayis, GC

    2013-08-01

    In this work we report the microstructure and magnetic property of single crystalline Nd2Fe14B ultrafine particles ball milled from HDDR Nd-Fe-B alloys. The average size of the particles is 283 nm, and TEM observation reveals that these particles are single crystalline. The coercivity of these particles is 6.0 kOe, which is much higher than that of the particles ball milled from sintered and hot pressed Nd-Fe-B magnets. Micromagnetic analysis shows that the coercivity degradation is caused by surface damage during ball milling. (C) 2013 Elsevier B.V. All rights reserved.

  2. High-Performance Ball Bearing

    Science.gov (United States)

    Bursey, Roger W., Jr.; Haluck, David A.; Olinger, John B.; Owen, Samuel S.; Poole, William E.

    1995-01-01

    High-performance bearing features strong, lightweight, self-lubricating cage with self-lubricating liners in ball apertures. Designed to operate at high speed (tens of thousands of revolutions per minute) in cryogenic environment like liquid-oxygen or liquid-hydrogen turbopump. Includes inner race, outer race, and cage keeping bearing balls equally spaced.

  3. Microstructure and Physical Properties of Tb2TiO5 Neutron Absorber Synthesized by Ball Milling and Sintering

    Science.gov (United States)

    Huang, Jinghua; Ran, Guang; Liu, Tengjiao; Shen, Qiang; Li, Ning

    2016-10-01

    Tb2TiO5 neutron absorber was synthesized by ball milling and sintering. Microstructure character of ball-milled Tb4O7-17.605%TiO2 (mass fraction, %) powders and sintered bulks was analyzed using XRD, SEM and TEM. The microhardness, coefficient of thermal expansion and thermal conductivity of sintered bulks were measured. The experiment results showed that the nanocrystalline solid solution was obtained during ball milling. After 96 h of ball milling, TiO2 was completely solved in Tb4O7 and the crystal size of Tb4O7 was up to 37 nm. The bulk materials prepared by cold isostatic pressing were sintered at 1300 °C. Tb2TiO5 bulks with an orthorhombic structure were obtained. The microhardness of sintered bulks, as well as the thermal conductivity, increased firstly with increasing ball milling time and then decreased. The coefficient of thermal expansion decreased initially and then increased with increasing ball milling time. For the sintered bulk with powder milled for 48 h, the highest values of both microhardness and thermal conductivity were observed, whereas the lowest coefficient of thermal expansion was exhibited. In addition, with increasing testing temperature, the thermal conductivity of sintered bulks initially fell and then rebounded while an opposite trend was found in the coefficient of thermal expansion.

  4. Joint Seabasing and Joint Vision 2020

    Science.gov (United States)

    2009-01-01

    provide strategic and operational effectiveness. 11 4 SEjA PO" VVER 21., Sea Shield Sea ’trilll Sea \\\\’nrrio. Sea Ent~rprise ... ,·SeaStrike·-- Figure...utilize new material handling systems, platform interface capabilities for load transfer, and sea state mitigation. The scalability and modularity of the...capability to supply the right equipment at the right time for most operations. Utilizing automated material - . handling systems, selective offload

  5. An analytical and numerical study of chaotic dynamics in a simple bouncing ball model

    Institute of Scientific and Technical Information of China (English)

    Andrzej Okninski; Boguslaw Radziszewski

    2011-01-01

    Dynamics of a ball moving in gravitational field and colliding with a moving table is studied in this paper.The motion of the limiter is assumed as periodic with piecewise constant velocity-it is assumed that the table moves up with a constant velocity and then moves down with another constant velocity. The Poincaré map, describing evolution from an impact to the next impact, is derived and scenarios of transition to chaotic dynamics are investigated analytically and numerically.

  6. Intra-oral PTH administration promotes tooth extraction socket healing.

    Science.gov (United States)

    Kuroshima, S; Kovacic, B L; Kozloff, K M; McCauley, L K; Yamashita, J

    2013-06-01

    Intermittent parathyroid hormone (PTH) administration increases systemic and craniofacial bone mass. However, the effect of PTH therapy on healing of tooth extraction sites is unknown. The aims of this study were to determine the effect of PTH therapy on tooth extraction socket healing and to examine whether PTH intra-oral injection promotes healing. The mandibular first molars were extracted in rats, and subcutaneous PTH was administered intermittently for 7, 14, and 28 days. In a second study, maxillary second molars were extracted, and PTH was administered by either subcutaneous or intra-oral injection to determine the efficacy of intra-oral PTH administration. Healing was assessed by micro-computed tomography and histomorphometric analyses. PTH therapy accelerated the entire healing process and promoted both hard- and soft-tissue healing by increasing bone fill and connective tissue maturation. PTH therapy by intra-oral injection was as effective as subcutaneous injection in promoting tooth extraction socket healing. The findings suggest that PTH therapy promotes tooth extraction socket healing and that intra-oral injections can be used to administer PTH.

  7. On diagnosis measurement under dynamic loading of ball bearing using numerical thermal analysis and infrared thermography

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Dong Pyo; Kim, Ho Jong [School of Mechanical System Engineering, Chonbuk Nationa University, Jeonju (Korea, Republic of); Kim, Won Tae [School of Mechanical and Automotive Engineering, Kongju National University, Kongju (Korea, Republic of)

    2013-08-15

    With the modern machinery towards the direction of high-speed development, the thermal issues of mechanical transmission system and its components is increasingly important. Ball bearing is one of the main parts in rotating machinery system, and is a more easily damaged part. In this paper, bearing thermal fault detection is investigated in details Using infrared thermal imaging technology to the operation state of the ball bearing, a preliminary thermal analysis, and the use of numerical simulation technology by finite element method(FEM) under thermal conditions of the bearing temperature field analysis, initially identified through these two technical analysis, bearing a temperature distribution in the normal state and failure state. It also shows the reliability of the infrared thermal imaging technology with valuable suggestions for the future bearing fault detection.

  8. Online Sparse System Identification and Signal Reconstruction using Projections onto Weighted $\\ell_1$ Balls

    CERN Document Server

    Kopsinis, Yannis; Theodoridis, Sergios

    2010-01-01

    This paper presents a novel projection-based adaptive algorithm for sparse signal and system identification. The sequentially observed data are used to generate an equivalent sequence of closed convex sets, namely hyperslabs. Each hyperslab is the geometric equivalent of a cost criterion, that quantifies "data mismatch". Sparsity is imposed by the introduction of appropriately designed weighted $\\ell_1$ balls. The algorithm develops around projections onto the sequence of the generated hyperslabs as well as the weighted $\\ell_1$ balls. The resulting scheme exhibits linear dependence, with respect to the unknown system's order, on the number of multiplications/additions and an $\\mathcal{O}(L\\log_2L)$ dependence on sorting operations, where $L$ is the length of the system/signal to be estimated. Numerical results are also given to validate the performance of the proposed method against the LASSO algorithm and two very recently developed adaptive sparse LMS and LS-type of adaptive algorithms, which are considere...

  9. 气动肌肉群驱动球关节机器人的无模型自适应控制%Model-Free Adaptive Control for the Ball-Joint Robot Driven by PMA Group

    Institute of Scientific and Technical Information of China (English)

    刘昱; 王涛; 范伟; 王渝

    2013-01-01

    设计了一种由气动肌肉群驱动的三轴球关节机器人,并对其进行逆运动学分析.根据该机器人的运动学逆解,提出了基于非线性反馈的气动肌肉群控制策略.气动肌肉系统是一个强非线性时变的自平衡系统,鉴于传统控制方法难以克服控制精度、响应速度和稳定性之间的矛盾,引入改进型无模型自适应控制器.实验证明,在保证稳定性的前提下,控制器提高了系统的调节速度和控制精度,使得系统的稳态误差小于0.3°,取得了良好的控制效果.%A triaxial ball-joint robot driven by PMA (pneumatic muscle actuator) group is designed. The inverse kinematics of the robot is analyzed. On the basis of its inverse kinematics analysis, the control strategy of the PMA group based on nonlinear feedback is proposed. The system of PMA is a strongly nonlinear and time-varying self-balanced system. Because it is difficult to overcome the conflict among the regulating speed, the stability and the control accuracy with traditional control methods, an improved model-free adaptive control is introduced. Experiments show that on the premise of ensuring the stability, the control accuracy and the adjusting speed are enhanced. The system's steady-error is less than 0.3?and a satisfactory control result is obtained.

  10. Frictional action at lower limb/prosthetic socket interface.

    Science.gov (United States)

    Zhang, M; Turner-Smith, A R; Roberts, V C; Tanner, A

    1996-04-01

    The frictional action at stump/socket interface is discussed by a simplified model and finite element model analyses and clinical pressure measurements. The friction applied to the stump skin produces stresses within tissue and these stresses may damage the tissues and affect their normal functions. The combination of normal and shear stresses is considered to be a critical factor leading to amputee's discomfort and tissue damage. However, friction at the stump/socket interface has a beneficial action. A simplified residual limb model and a finite element model using real geometry have been developed to analyse the support action of friction. Both results show that the friction plays a critical role both in supporting the load of the amputee's body during the support phase of the gait cycle and in preventing the prosthesis from slipping off the limb during swing phase. Pressure at the below-knee socket during walking were measured with conditions of different friction. The results reveal that a larger pressures was produced at the lubricated interface than at the normal interface. A proper choice of coefficient of friction will balance the requirements of relief of load stress and reduction of slip with the general ability to support loads.

  11. Break-up Process of Perturbed Molten Metal Jet and Preparation of Lead-Free Solder Balls

    Institute of Scientific and Technical Information of China (English)

    He Lijun; Zhang Shuguang; Zhang Shaoming; Xu Jun; Shi Likai

    2004-01-01

    Solder balls, which are used in advanced electronics packages such as BGA (Ball Grid Array) and CSP (Chip Scale Package) to substitute the leads and realize the electrical and mechanical connections between substrate and chip,have severe specifications in diameter tolerance, roundness and surface quality, and therefore challenge the traditional technologies for fabrication of metallic particles and powders. The present work made a survey of perturbed molten metal jet break-up process, observed the formation and growth of capillary wave of tin-lead melt jet by way of rapid solidification, and on the basis of the above research, successfully obtained tin-lead eutectic and Sn-4.0Ag-0.5Cu lead free solder balls with tight distribution and good sphericity of particles through optimization of processing parameters, forming a solid base for cost effectively producing solder balls.

  12. CANDIDATE TREE-IN-BUD PATTERN SELECTION AND CLASSIFICATION USING BALL SCALE ENCODING ALGORITHM

    Directory of Open Access Journals (Sweden)

    T. Akilandeswari

    2013-10-01

    Full Text Available Asthma, Chronic obstructive pulmonary disease, influenza, pneumonia, tuberculosis, lung cancer and many other breathing problems are the leading causes of death and disability all over the world. These diseases affect the lung. Radiology is a primary assessing method with low specificity of the prediction of the presence of these diseases. Computer Assisted Detection (CAD will help the specialists in detecting one of these diseases in an early stage. A method has been proposed by Ulas Bagci to detect lung abnormalities using Fuzzy connected object estimation, Ball scale encoding and comparing various features extracted from local patches of the lung images (CT scan. In this paper, the Tree-in-Bud patterns are selected after segmentation by using ball scale encoding algorithm.

  13. TCP/IP Sockets in C# Practical Guide for Programmers

    CERN Document Server

    Makofske, David; Calvert, Kenneth L

    2004-01-01

    "TCP/IP sockets in C# is an excellent book for anyone interested in writing network applications using Microsoft .Net frameworks. It is a unique combination of well written concise text and rich carefully selected set of working examples. For the beginner of network programming, it''s a good starting book; on the other hand professionals could also take advantage of excellent handy sample code snippets and material on topics like message parsing and asynchronous programming."Adarsh Khare, SDT, .Net Frameworks Team, Microsoft CorporationThe popularity of the C# language and the .NET framework is ever rising due to its ease of use, the extensive class libraries available in the .NET Framework, and the ubiquity of the Microsoft Windows operating system, to name a few advantages. TCP/IP Sockets in C# focuses on the Sockets API, the de facto standard for writing network applications in any programming language. Starting with simple client and server programs that use TCP/IP (the Internet protocol suite), students ...

  14. Charged Q-ball dark matter from B and L direction

    Science.gov (United States)

    Hong, Jeong-Pyong; Kawasaki, Masahiro; Yamada, Masaki

    2016-08-01

    We consider nearly equal number of gauge mediation type charged (anti-) Q-balls with charge of ±α-1 simeq ±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 109 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.

  15. Charged Q-ball Dark Matter from $B$ and $L$ direction

    CERN Document Server

    Hong, Jeong-Pyong; Yamada, Masaki

    2016-01-01

    We consider nearly equal number of gauge mediation type charged (anti-) Q-balls with charge of $\\alpha^{-1}\\simeq137$ 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 $10^9$ 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.

  16. Amorphous solid dispersions of sulfonamide/soluplus® and sulfonamide/PVP prepared by ball milling

    OpenAIRE

    Healy, Anne,

    2013-01-01

    PUBLISHED The aim of this paper is to investigate the physicochemical properties of binary amorphous dispersions of poorly soluble sulfonamide/polymeric excipient prepared by ball milling. The sulfonamides selected were sulfathiazole (STZ), sulfadimidine (SDM), sulfamerazine (SMZ) and sulfadiazine (SDZ). The excipients were polyvinylpyrrolidone (PVP) and polyvinyl caprolactam-polyvinyl acetate-polyethylene glycol graft co-polymer, commercially known as Soluplus®. Co-milled systems were cha...

  17. 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.

  18. Cosmological phase transition, baryon asymmetry and dark matter Q-balls

    CERN Document Server

    Krylov, E; Rubakov, V

    2013-01-01

    We consider a mechanism of dark matter production in the course of first order phase transition. We assume that there is an asymmetry between X- and anti-X-particles of dark sector. In particular, it may be related to the baryon asymmetry. We also assume that the phase transition is so strongly first order, that X-particles do not permeate into the new phase. In this case, as the bubbles of old phase collapse, X-particles are packed into Q-balls with huge mass defect. These Q-balls compose the present dark matter. We find that the required present dark matter density is obtained for the energy scale of the theory in the ballpark of 1-10 TeV. As an example we consider a theory with effective potential of one-loop motivated form.

  19. The Quantum Socket: Wiring for Superconducting Qubits - Part 2

    Science.gov (United States)

    Bejanin, J. H.; McConkey, T. G.; Rinehart, J. R.; Bateman, J. D.; Earnest, C. T.; McRae, C. H.; Rohanizadegan, Y.; Shiri, D.; Mariantoni, M.; Penava, B.; Breul, P.; Royak, S.; Zapatka, M.; Fowler, A. G.

    Quantum computing research has reached a level of maturity where quantum error correction (QEC) codes can be executed on linear arrays of superconducting quantum bits (qubits). A truly scalable quantum computing architecture, however, based on practical QEC algorithms, requires nearest neighbor interaction between qubits on a two-dimensional array. Such an arrangement is not possible with techniques that rely on wire bonding. To address this issue, we have developed the quantum socket, a device based on three-dimensional wires that enables the control of superconducting qubits on a two-dimensional grid. In this talk, we present experimental results characterizing this type of wiring. We will show that the quantum socket performs exceptionally well for the transmission and reflection of microwave signals up to 10 GHz, while minimizing crosstalk between adjacent wires. Under realistic conditions, we measured an S21 of -5 dB at 6 GHz and an average crosstalk of -60 dB. We also describe time domain reflectometry results and arbitrary pulse transmission tests, showing that the quantum socket can be used to control superconducting qubits.

  20. Vertical bounce of two vertically aligned balls

    Science.gov (United States)

    Cross, Rod

    2007-11-01

    When a tennis ball rests on top of a basketball and both drop to the floor together, the tennis ball is projected vertically at high speed. A mass-spring model of the impact, as well as air track data, suggest that the tennis ball should be projected at relatively low speed. Measurements of the forces on each ball and the bounce of vertically aligned superballs are used to resolve the discrepancy.

  1. 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.

  2. Magnetoresistivity and microstructure of YBa2Cu3Oy prepared using planetary ball milling

    Science.gov (United States)

    Hamrita, A.; Ben Azzouz, F.; Madani, A.; Ben Salem, M.

    2012-01-01

    We have studied the microstructure and the magnetoresistivity of polycrystalline YBa2Cu3Oy (YBCO or Y-123 for brevity) embedded with nanoparticles of Y-deficient YBCO, generated by the planetary ball milling technique. Bulk samples were synthesized from a precursor YBCO powder, which was prepared from commercial high purity Y2O3, Ba2CO3 and CuO via a one-step annealing process in air at 950 °C. After planetary ball milling of the precursor, the powder was uniaxially pressed and subsequently annealed at 950 °C in air. Phase analysis by X-ray diffraction (XRD), granular structure examination by scanning electron microscopy (SEM), microstructure investigation by transmission electron microscopy (TEM) coupled with energy dispersive X-ray spectroscopy (EDXS) were carried out. TEM analyses show that nanoparticles of Y-deficient YBCO, generated by ball milling, are embedded in the superconducting matrix. Electrical resistance as a function of temperature, ρ(T), revealed that the zero resistance temperature, Tco, is 84.5 and 90 K for the milled and unmilled samples respectively. The milled ceramics exhibit a large magnetoresistance in weak magnetic fields at liquid nitrogen temperature. This attractive effect is of high significance as it makes these materials promising candidates for practical application in magnetic field sensor devices.

  3. Stiffness matrix formulation for double row angular contact ball bearings: Analytical development and validation

    Science.gov (United States)

    Gunduz, Aydin; Singh, Rajendra

    2013-10-01

    Though double row angular contact ball bearings are widely used in industrial, automotive, and aircraft applications, the scientific literature on double row bearings is sparse. It is also shown that the stiffness matrices of two single row bearings may not be simply superposed to obtain the stiffness matrix of a double row bearing. To overcome the deficiency in the literature, a new, comprehensive, analytical approach is proposed based on the Hertzian theory for back-to-back, face-to-face, and tandem arrangements. The elements of the five-dimensional stiffness matrix for double row angular contact ball bearings are computed given either the mean bearing displacement or the mean load vector. The diagonal elements of the proposed stiffness matrix are verified with a commercial code for all arrangements under three loading scenarios. Some changes in stiffness coefficients are investigated by varying critical kinematic and geometric parameters to provide more insight. Finally, the calculated natural frequencies of a shaft-bearing experiment are successfully compared with measurements, thus validating the proposed stiffness formulation. For double row angular contact ball bearings, the moment stiffness and cross-coupling stiffness terms are significant, and the contact angle changes under loads. The proposed formulation is also valid for paired (duplex) bearings which behave as an integrated double row unit when the surrounding structural elements are sufficiently rigid.

  4. Joint Measurability and Temporal Steering

    OpenAIRE

    Karthik, H. S.; Tej, J Prabhu; Devi, A. R. Usha; Rajagopal, A. K.

    2014-01-01

    Quintino et. al. (Phys. Rev. Lett. 113, 160402 (2014)) and Uola et. al. (Phys. Rev. Lett. 113, 160403 (2014)) have recently established an intrinsic relation between non-joint measurability and Einstein-Podolsky- Rosen steering. They showed that a set of measurements is incompatible (i.e., not jointly measurable) if and only if it can be used for the demonstration of steering. In this paper, we prove the temporal analog of this result viz., a set of measurements are incompatible if and only i...

  5. Silicon Nitride Balls For Cryogenic Bearings

    Science.gov (United States)

    Butner, Myles F.; Ng, Lillian W.

    1990-01-01

    Resistance to wear greater than that of 440C steel. Experiments show lives of ball bearings immersed in liquid nitrogen or liquid oxygen increased significantly when 440C steel balls (running on 440C steel races) replaced by balls of silicon nitride. Developed for use at high temperatures, where lubrication poor or nonexistent. Best wear life of any bearing tested to date and ball material spalls without fracturing. Plans for future tests call for use of liquid oxygen as working fluid.

  6. [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.

  7. Have a Ball

    Institute of Scientific and Technical Information of China (English)

    程炜

    2003-01-01

    Before being sent to prison Carl drove big cars and ate in expensive restaurants. No one knew where he got his money but he was certainly having a ball. When the judge sentenced him.to prison he said, “I hope you have a bail, Carl.” To have a bait is to have a wonderful time.

  8. Increasing speed to improve arm movement and standing postural control in Parkinson's disease patients when catching virtual moving balls.

    Science.gov (United States)

    Su, Kuei-Jung; Hwang, Wen-Juh; Wu, Ching-yi; Fang, Jing-Jing; Leong, Iat-Fai; Ma, Hui-Ing

    2014-01-01

    Research has shown that moving targets help Parkinson's disease (PD) patients improve their arm movement while sitting. We examined whether increasing the speed of a moving ball would also improve standing postural control in PD patients during a virtual reality (VR) ball-catching task. Twenty-one PD patients and 21 controls bilaterally reached to catch slow-moving and then fast-moving virtual balls while standing. A projection-based VR system connected to a motion-tracking system and a force platform was used. Dependent measures included the kinematics of arm movement (movement time, peak velocity), duration of anticipatory postural adjustments (APA), and center of pressure (COP) movement (movement time, maximum amplitude, and average velocity). When catching a fast ball, both PD and control groups made arm movements with shorter movement time and higher peak velocity, longer APA, as well as COP movements with shorter movement time and smaller amplitude than when catching a slow ball. The change in performance from slow- to fast-ball conditions was not different between the PD and control groups. The results suggest that raising the speed of virtual moving targets should increase the speed of arm and COP movements for PD patients. Therapists, however, should also be aware that a fast virtual moving target causes the patient to confine the COP excursion to a smaller amplitude. Future research should examine the effect of other task parameters (e.g., target distance, direction) on COP movement and examine the long-term effect of VR training.

  9. Application of the Blobo bluetooth ball in wrist rehabilitation training.

    Science.gov (United States)

    Hsieh, Wei-Min; Hwang, Yuh-Shyan; Chen, Shih-Ching; Tan, Sun-Yen; Chen, Chih-Chen; Chen, Yu-Luen

    2016-01-01

    [Purpose] The introduction of emerging technologies such as the wireless Blobo bluetooth ball with multimedia features can enhance wrist physical therapy training, making it more fun and enhancing its effects. [Methods] Wrist injuries caused by fatigue at work, improper exercise, and other conditions are very common. Therefore, the reconstruction of wrist joint function is an important issue. The efficacy of a newly developed integrated wrist joint rehabilitation game using a Blobo bluetooth ball with C# software installed was tested in wrist rehabilitation (Flexion, Extension, Ulnar Deviation, Radial Deviation). [Results] Eight subjects with normal wrist function participated in a test of the system's stability and repeatability. After performing the Blobo bluetooth ball wrist physical therapy training, eight patients with wrist dysfunction experienced approximately 10° improvements in range of motion (ROM) of flexion extension, and ulnar deviation and about 6° ROM improvement in radial deviation. The subjects showed progress in important indicators of wrist function. [Conclusion] This study used the Blobo bluetooth ball in wrist physical therapy training and the preliminary results were encouraging. In the future, more diverse wrist or limb rehabilitation games should be developed to meet the needs of physical therapy training.

  10. 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.

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

    Directory of Open Access Journals (Sweden)

    Peter Bacopoulos

    2014-03-01

    Full Text Available 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-up trends. Archives of the electronic data, including GPS locations and other informational tags, and collected samples are presented, as are the physical and chemical analyses of the collected samples. The thrust of the physical and chemical analyses is to differentiate the collected samples into highly suspect oil tar balls versus false/non-oil tar ball samples. The numerical modeling involves two-dimensional hydrodynamic simulations of astronomic tides. Results from the numerical modeling include velocity residuals that show ebb-dominated residual currents exiting the inlet via an offshore, counter-rotating dual-eddy system. The tidally derived residual currents are used as one explanation for the observed transport trends. The study concludes that the port activity in the St. Johns River is not majorly contributing to the baseline conditions of oil tar ball wash-up on Florida’s First Coast beaches.

  12. Visual Illusions and the Control of Ball Placement in Goal-Directed Hitting

    Science.gov (United States)

    Caljouw, Simone R.; Van der Kamp, John; Savelsbergh, Geert J. P.

    2010-01-01

    When hitting, kicking, or throwing balls at targets, online control in the target area is impossible. We assumed this lack of late corrections in the target area would induce an effect of a single-winged Muller-Lyer illusion on ball placement. After extensive practice in hitting balls to different landing locations, participants (N = 9) had to hit…

  13. Visual Illusions and the Control of Ball Placement in Goal-Directed Hitting

    NARCIS (Netherlands)

    Caljouw, Simone R.; Van der Kamp, John; Savelsbergh, Geert J. P.

    2010-01-01

    When hitting, kicking, or throwing balls at targets, online control in the target area is impossible We assumed this lack of late corrections in the target area would induce an effect of a single-winged Muller-Lyer illusion on ball placement After extensive practice in hitting balls to different lan

  14. Experimental Analysis of Damping and Tribological Characteristics of Nano-CuO Particle Mixed Lubricant in Ball Bearings

    Science.gov (United States)

    Prakash, E.; Sivakumar, K.

    2015-12-01

    Experimental analysis of damping capacity and tribological characteristics of nano CuO added Servosystem 68 lubricant is attempted. CuO nano particles were synthesized by aqueous precipitation method and characterized. Prior to dispersion into lubricant, CuO nano particles were coated with 0.2 wt.% surfactant (Span-80) to stabilize the nano fluid. Tribological characteristics of particle added lubricant were tested in ASTM D 4172 four ball wear tester. Scanning electron microscopy test results of worn surfaces of nano CuO particle added lubricant were smoother than base lubricant. The particle added lubricant was applied in a new ball bearing and three defected ball bearings. When particle added lubricant was used, the ball defected bearing's vibration amplitude was reduced by 21.94% whereas it was 16.46% for new bearing and was ≤ 11% for other defected bearings. The formation of protection film of CuO over ball surface and regime of full film lubrication near the ball zone were observed to be reason for improved damping of vibrations.

  15. Bouncing Balls that Spin

    Science.gov (United States)

    Knipp, Peter

    2008-01-01

    When a ball bounces elastically against a floor, the vertical component (v[subscript y]) of the velocity of the ball's mass-center changes sign. This is a special case of the elastic collision of two balls (i.e., two objects, neither of which is much more massive than the other), in which case the balls' post-collision relative velocity (=…

  16. Design and wear testing of a temporomandibular joint prosthesis articulation

    NARCIS (Netherlands)

    van Loon, JP; Verkerke, GJ; de Vries, MP; de Bont, LGM

    2000-01-01

    As part of the development of a total temporomandibular joint prosthesis, a prosthesis articulation was designed. The articulation consists of a spherical head (ball) of the mandibular part, rotating against an enveloping ultra-high-molecular-weight polyethylene (UHMWPE) disc with a flat cranial sid

  17. Effect of prosthetic alignment changes on socket reaction moment impulse during walking in transtibial amputees.

    Science.gov (United States)

    Kobayashi, Toshiki; Orendurff, Michael S; Arabian, Adam K; Rosenbaum-Chou, Teri G; Boone, David A

    2014-04-11

    The alignment of a lower limb prosthesis affects the way load is transferred to the residual limb through the socket, and this load is critically important for the comfort and function of the prosthesis. Both magnitude and duration of the moment are important factors that may affect the residual limb health. Moment impulse is a well-accepted measurement that incorporates both factors via moment-time integrals. The aim of this study was to investigate the effect of alignment changes on the socket reaction moment impulse in transtibial prostheses. Ten amputees with transtibial prostheses participated in this study. The socket reaction moment impulse was measured at a self-selected walking speed using a Smart Pyramid in 25 alignment conditions, including a nominal alignment (clinically aligned by a prosthetist), as well as angle malalignments of 2°, 4° and 6° (abduction, adduction, extension and flexion) and translation malalignments of 5 mm, 10 mm and 15 mm (lateral, medial, anterior and posterior). The socket reaction moment impulse of the nominal alignment was compared for each condition. The relationship between the alignment and the socket reaction moment impulse was clearly observed in the coronal angle, coronal translation and sagittal translation alignment changes. However, this relationship was not evident in the sagittal angle alignment changes. The results of this study suggested that the socket reaction moment impulse could potentially serve as a valuable parameter to assist the alignment tuning process for transtibial prostheses. Further study is needed to investigate the influence of the socket reaction moment impulse on the residual limb health.

  18. A comparison of ball velocity in different kicking positions with dominant and non-dominant leg in junior soccer players

    Directory of Open Access Journals (Sweden)

    MÁRIO C. MARQUES

    2011-06-01

    Full Text Available Problem Statement: The aim of this study was to compare the ball velocity in different kicking conditions with dominant and non-dominant leg in junior soccer players.Approach: Sixteen junior soccer players (age 17.6±0.6yr, height 1.76±0.06m, and weight 67.9±5.2kg participated in this study. All participants kicked a soccer ball three times in seven conditions with the dominant and non-dominant leg. 1 Kicking the ball from 11m straight forwards, 2 and 3 kicking the ball from 11m to the left and right side of the goal, 4 and 5 kicking the ball straight forwards from 11m after a pass from the left and right side, 6 and 7 kicking the ball straight forwards from 11m after a pass that came from a diagonal position (45º from the left and right side. The highest ball velocity was used for analysis.Results: Significant differences were found in ball velocity between the dominant and non-dominant leg in all conditions (p<0.001. For the dominant leg also significant differences were found in the kicking of eleven meters (ideal conditions compared with: the perpendicular passing kick after the ball on the right (p=0.0024 and left (p=0.0080 and also with a diagonal kick after pass (45 ° of the ball on the right (p=0.0017 and left (p = 0.0381. Significant differences in the kicking with the non-dominant leg were found when kicking from eleven meters to the right side of the goal in comparison to: the kick under the same conditions, to the left side of the goal (p=0.0243 after pass and shot from the left side perpendicular (p=0.0222.Conclusions/Recommendations: kicking velocity is influenced very much under different conditions when kicking with the dominant leg while for the non-dominant leg this influence was small, because the non-dominant leg is less trained, so the values of velocity in different conditions, in addition to being the lowest, are closer than those obtained with the dominant leg

  19. Shoulder arthroscopy

    Science.gov (United States)

    ... ball and socket joint) A torn or damaged biceps tendon A torn rotator cuff A bone spur ... repair. Using arthroscopy for rotator cuff repairs or tendinitis usually relieves the pain, but you may not ...

  20. Algebraic reasoning and bat-and-ball problem variants: Solving isomorphic algebra first facilitates problem solving later.

    Science.gov (United States)

    Hoover, Jerome D; Healy, Alice F

    2017-02-14

    The classic bat-and-ball problem is used widely to measure biased and correct reasoning in decision-making. University students overwhelmingly tend to provide the biased answer to this problem. To what extent might reasoners be led to modify their judgement, and, more specifically, is it possible to facilitate problem solution by prompting participants to consider the problem from an algebraic perspective? One hundred ninety-seven participants were recruited to investigate the effect of algebraic cueing as a debiasing strategy on variants of the bat-and-ball problem. Participants who were cued to consider the problem algebraically were significantly more likely to answer correctly relative to control participants. Most of this cueing effect was confined to a condition that required participants to solve isomorphic algebra equations corresponding to the structure of bat-and-ball question types. On a subsequent critical question with differing item and dollar amounts presented without a cue, participants were able to generalize the learned information to significantly reduce overall bias. Math anxiety was also found to be significantly related to bat-and-ball problem accuracy. These results suggest that, under specific conditions, algebraic reasoning is an effective debiasing strategy on bat-and-ball problem variants, and provide the first documented evidence for the influence of math anxiety on Cognitive Reflection Test performance.

  1. Deployable robotic woven wire structures and joints for space applications

    Science.gov (United States)

    Shahinpoor, MO; Smith, Bradford

    1991-01-01

    Deployable robotic structures are basically expandable and contractable structures that may be transported or launched to space in a compact form. These structures may then be intelligently deployed by suitable actuators. The deployment may also be done by means of either airbag or spring-loaded typed mechanisms. The actuators may be pneumatic, hydraulic, ball-screw type, or electromagnetic. The means to trigger actuation may be on-board EPROMS, programmable logic controllers (PLCs) that trigger actuation based on some input caused by the placement of the structure in the space environment. The actuation may also be performed remotely by suitable remote triggering devices. Several deployable woven wire structures are examined. These woven wire structures possess a unique form of joint, the woven wire joint, which is capable of moving and changing its position and orientation with respect to the structure itself. Due to the highly dynamic and articulate nature of these joints the 3-D structures built using them are uniquely and highly expandable, deployable, and dynamic. The 3-D structure naturally gives rise to a new generation of deployable three-dimensional spatial structures.

  2. Ball assisted device for analytical surface sampling

    Science.gov (United States)

    ElNaggar, Mariam S; Van Berkel, Gary J; Covey, Thomas R

    2015-11-03

    A system for sampling a surface includes a sampling probe having a housing and a socket, and a rolling sampling sphere within the socket. The housing has a sampling fluid supply conduit and a sampling fluid exhaust conduit. The sampling fluid supply conduit supplies sampling fluid to the sampling sphere. The sampling fluid exhaust conduit has an inlet opening for receiving sampling fluid carried from the surface by the sampling sphere. A surface sampling probe and a method for sampling a surface are also disclosed.

  3. The dynamics of hurricane balls

    Science.gov (United States)

    Andersen, W. L.; Werner, Steven

    2015-09-01

    We examine the theory of the hurricane balls toy. This toy consists of two steel balls, welded together that are sent spinning on a horizontal surface somewhat like a top. Unlike a top, at high frequency the symmetry axis approaches a limiting inclination that is not perpendicular to the surface. We calculate (and experimentally verify) the limiting inclinations for three toy geometries. We find that at high frequencies, hurricane balls provide an easily realized and testable example of the Poinsot theory of freely rotating symmetrical bodies.

  4. The similarities between the hallucinations associated with the partial epileptic seizures of the occipital lobe and ball lightning observations

    Science.gov (United States)

    Cooray, G. K.; Cooray, V.

    2007-12-01

    Ball Lightning was seen and described since antiquity and recorded in many places. Ball lightning is usually observed during thunderstorms but large number of ball lightning observations is also reported during fine weather without any connection to thunderstorms or lightning. However, so far no one has managed to generate them in the laboratory. It is photographed very rarely and in many cases the authenticity of them is questionable. It is possible that many different phenomena are grouped together and categorized simply as ball lightning. Indeed, the visual hallucinations associated with simple partial epileptic seizures, during which the patient remains conscious, may also be categorized by a patient unaware of his or her condition as ball lightning observation. Such visual hallucinations may occur as a result of an epileptic seizure in the occipital, temporo-occipital or temporal lobes of the cerebrum [1,2,3]. In some cases the hallucination is perceived as a coloured ball moving horizontally from the periphery to the centre of the vision. The ball may appear to be rotating or spinning. The colour of the ball can be red, yellow, blue or green. Sometimes, the ball may appear to have a solid structure surrounded by a thin glow or in other cases the ball appears to generate spark like phenomena. When the ball is moving towards the centre of the vision it may increase its intensity and when it reaches the centre it can 'explode' illuminating the whole field of vision. During the hallucinations the vision is obscured only in the area occupied by the apparent object. The hallucinations may last for 5 to 30 seconds and rarely up to a minute. Occipital seizures may spread into other regions of the brain giving auditory, olfactory and sensory sensations. These sensations could be buzzing sounds, the smell of burning rubber, pain with thermal perception especially in the arms and the face, and numbness and tingling sensation. In some cases a person may experience only

  5. Rhythmic Gymnastics: A Challenge with Balls and Ropes.

    Science.gov (United States)

    Bennett, John P.

    Rhythmic gymnastics is an outgrowth of rhythmic and dance gymnastics and promotes good posture, strength, flexibility, balance, and coordination, along with appreciation of music and movement together. The current status of rhythmic gymnastics and its historical development are briefly discussed. Descriptions are given of rhythmic gymnastic…

  6. Super Ball Bot - Structures for Planetary Landing and Exploration Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Small, light-weight and low-cost missions will become increasingly important to NASA's exploration goals. Ideally teams of small, collapsible robots, weighing...

  7. Super Ball Bot - Structures for Planetary Landing and Exploration Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Small, light-weight and low-cost missions will become increasingly important to NASA's exploration goals for our solar system. Ideally teams of dozens or even...

  8. Synthesis, characterization and gas sensing properties of novel homo and hetero dinuclear ball-type phthalocyanines.

    Science.gov (United States)

    Kakı, Esra; Altındal, Ahmet; Salih, Bekir; Bekaroğlu, Özer

    2015-05-01

    New ball-type homodinuclear Co(ii)-Co(ii) phthalocyanine () and ball-type heterodinuclear Co(ii)-Fe(ii) phthalocyanine () were synthesized from the corresponding [2,10,16,24-tetrakis{4,4'-cyclohexylidenebis(2-cyclohexyphenoxyphthalonitrile)}phthalocyaninatocobalt(ii)] (). The novel compounds have been characterized by elemental analysis, IR, UV-Vis and MALDI-TOF mass spectroscopy. Gas sensing capability of the spin coated film of and were studied using amperometric technique at various temperatures. For a better understanding of the interaction of and films with organic compounds, two different groups of compounds (aromatics and alcohols) were selected as test analytes. It was observed that the operating temperature had a considerable effect on the gas sensing performance of the sensors investigated. The experimental results show that film offers a promising perspective as a sensing material for the detection of relatively low aromatic vapours even at room temperature. This suggests that aromatics might be distinguished from alcohols. The obtained data were analysed using two different adsorption kinetic models: the pseudo first order equation and Elovich equation to determine the best fit equation for the adsorption of toluene vapor onto and films. The first-order equation was the best of the various kinetic models studied to describe the adsorption kinetic of toluene on Pc films at higher concentrations, as evidenced by the highest correlation coefficients. In addition, it was observed that Elovich equation generates a straight line that best fit to the data of adsorption of lower concentrations of toluene.

  9. Ball Mill Synthesis of Bulk Quaternary Cu2ZnSnSe4 and Thermoelectric Studies

    Science.gov (United States)

    Tiwari, Kunal J.; Prem Kumar, D. S.; Mallik, Ramesh Chandra; Malar, P.

    2017-01-01

    In this work, quaternary chalcogenide Cu2ZnSnSe4 (CZTSe) was synthesized using a mechanochemical ball milling process and its thermoelectric properties were studied by electrical resistivity, Seebeck coefficient, and thermal conductivity measurements. The synthesis process comprises three steps viz., wet ball milling of the elemental precursors, vacuum annealing, and densification by hot pressing. The purpose of this is to evaluate the feasibility of introducing wet milling in place of vacuum melting in solid state synthesis for the reaction of starting elements. We report the structural characterization and thermoelectric studies conducted on samples that were milled at 300 rpm and 500 rpm. X-ray diffraction (XRD) analysis showed the existence of multiple phases in the as-milled samples, indicating the requirement for heat treatment. Therefore, the ball milled powders were cold pressed and vacuum annealed to eliminate the secondary phases. Annealed samples were hot pressed and made into dense pellets for further investigations. In addition to XRD, energy dispersive spectroscopy (EDS) studies were performed on hot pressed samples to study the composition. XRD and EDS studies confirm CZTSe phase formation along with ZnSe secondary phase. Electrical resistivity and Seebeck coefficient measurements were done on the hot pressed samples in the temperature range 340-670 K to understand the thermoelectric behaviour. Thermal conductivity was calculated from the specific heat capacity and thermal diffusivity values. The thermoelectric figure of merit zT values for samples milled at 300 rpm and 500 rpm are ˜0.15 and ˜0.16, respectively, at 630 K, which is in good agreement with the values reported for solid state synthesized compounds.

  10. Evaluation of guided bone generation around implants placed into fresh extraction sockets: an experimental study in dogs

    DEFF Research Database (Denmark)

    Gotfredsen, K; Nimb, L; Buser, D

    1993-01-01

    . The objective of this study was to evaluate the crestal bone healing response adjacent to implants placed immediately into fresh extraction sockets with and without covering membranes. Eight adult mongrel dogs had the third and fourth mandibular premolars extracted bilaterally. Thirty-two submerged titanium...... an implant is placed immediately into an extraction socket, it may not engage the walls of the socket near the crest of the alveolar ridge. With the presence of a bone defect around an implant, ingrowth of soft tissue could compromise the achievement of osseointegration in the crestal bone area...

  11. Sliding and Rolling: The Physics of a Rolling Ball.

    Science.gov (United States)

    Hierrezuelo, J.; Carnero, C.

    1995-01-01

    Presents an approach that provides a simple and adequate procedure for introducing the concept of rolling friction. Discusses some aspects related to rolling motion that are the source of students' misconceptions. Presents several didactic suggestions. (JRH)

  12. Boiler and Pressure Balls Monopropellant Thermal Rocket Engine

    Science.gov (United States)

    Greene, William D. (Inventor)

    2009-01-01

    The proposed technology is a rocket engine cycle utilizing as the propulsive fluid a low molecular weight, cryogenic fluid, typically liquid hydrogen, pressure driven, heated, and expelled through a nozzle to generate high velocity and high specific impulse discharge gas. The proposed technology feeds the propellant through the engine cycle without the use of a separate pressurization fluid and without the use of turbomachinery. Advantages of the proposed technology are found in those elements of state-of-the-art systems that it avoids. It does not require a separate pressurization fluid or a thick-walled primary propellant tank as is typically required for a classical pressure-fed system. Further, it does not require the acceptance of intrinsic reliability risks associated with the use of turbomachinery

  13. Detection of Prosthetic Knee Movement Phases via In-Socket Sensors: A Feasibility Study.

    Science.gov (United States)

    El-Sayed, Amr M; Hamzaid, Nur Azah; Tan, Kenneth Y S; Abu Osman, Noor Azuan

    2015-01-01

    This paper presents an approach of identifying prosthetic knee movements through pattern recognition of mechanical responses at the internal socket's wall. A quadrilateral double socket was custom made and instrumented with two force sensing resistors (FSR) attached to specific anterior and posterior sites of the socket's wall. A second setup was established by attaching three piezoelectric sensors at the anterior distal, anterior proximal, and posterior sites. Gait cycle and locomotion movements such as stair ascent and sit to stand were adopted to characterize the validity of the technique. FSR and piezoelectric outputs were measured with reference to the knee angle during each phase. Piezoelectric sensors could identify the movement of midswing and terminal swing, pre-full standing, pull-up at gait, sit to stand, and stair ascent. In contrast, FSR could estimate the gait cycle stance and swing phases and identify the pre-full standing at sit to stand. FSR showed less variation during sit to stand and stair ascent to sensitively represent the different movement states. The study highlighted the capacity of using in-socket sensors for knee movement identification. In addition, it validated the efficacy of the system and warrants further investigation with more amputee subjects and different sockets types.

  14. Charged Q-balls and boson stars and dynamics of charged test particles

    CERN Document Server

    Brihaye, Yves; Hartmann, Betti

    2014-01-01

    We construct electrically charged Q-balls and boson stars in a model with a scalar self-interaction potential resulting from gauge mediated supersymmetry breaking. We discuss the properties of these solutions in detail and emphasize the differences to the uncharged case. We observe that $Q$-balls can only be constructed up to a maximal value of the charge of the scalar field, while for boson stars the interplay between the attractive gravitational force and the repulsive electromagnetic force determines their behaviour. We also study the motion of charged, massive test particles in the space-time of boson stars. We find that in contrast to charged black holes the motion of charged test particles in charged boson star space-times is planar, but that the presence of the scalar field plays a crucial r\\^ole for the qualitative features of the trajectories. Applications of this test particle motion can be made in the study of extreme-mass ratio inspirals (EMRIs) as well as astrophysical plasmas relevant e.g. in th...

  15. Numerical analysis of loaded stress and central displacement of deep groove ball bearing

    Institute of Scientific and Technical Information of China (English)

    杨磊; 邓松; 李红星

    2016-01-01

    The aim of this work is to develop a three-dimensional model of deep groove ball bearing to investigate the loaded stresses and central displacements of bearing rings. The equivalent stresses and central displacements of bearing rings are obtained based on the simulated analysis. Moreover, several parameters, such as load magnitude, raceway groove curvature radius (RGCR), thicknesses of outer and inner rings, are varied to investigate their effects on the equivalent stresses and central displacements of bearing rings. Research results provide useful guidelines for determining the design parameters.

  16. Balls, cups, and quasi-potentials: quantifying stability in stochastic systems.

    Science.gov (United States)

    Nolting, Ben C; Abbott, Karen C

    2016-04-01

    When a system has more than one stable state, how can the stability of these states be compared? This deceptively simple question has important consequences for ecosystems, because systems with alternative stable states can undergo dramatic regime shifts. The probability, frequency, duration, and dynamics of these shifts will all depend on the relative stability of the stable states. Unfortunately, the concept of "stability" in ecology has suffered from substantial confusion and this is particularly problematic for systems where stochastic perturbations can cause shifts between coexisting alternative stable states. A useful way to visualize stable states in stochastic systems is with a ball-in-cup-diagram, in which the state of the system is represented as the position of a ball rolling on a surface, and the random perturbations can push the ball from one basin of attraction to another. The surface is determined by a potential function, which provides a natural stability metric. Systems amenable to this representation, called gradient systems, are quite rare, however. As a result, the potential function is not widely used and other approaches based on linear stability analysis have become standard. Linear stability analysis is designed for local analysis of deterministic systems and, as we show, can produce a highly misleading picture of how the system will behave under continual, stochastic perturbations. In this paper, we show how the potential function can be generalized so that it can be applied broadly, employing a concept from stochastic analysis called the quasi-potential. Using three classic ecological models, we demonstrate that the quasi-potential provides a useful way to quantify stability in stochastic systems. We show that the quasi-potential framework helps clarify long-standing confusion about stability in stochastic ecological systems, and we argue that ecologists should adopt it as a practical tool for analyzing these systems.

  17. Flexible joints in structural and multibody dynamics

    OpenAIRE

    O. A. Bauchau; Han, S.

    2013-01-01

    Flexible joints, sometimes called bushing elements or force elements, are found in all structural and multibody dynamics codes. In their simplest form, flexible joints simply consist of sets of three linear and three torsional springs placed between two nodes of the model. For infinitesimal deformations, the selection of the lumped spring constants is an easy task, which can be based on a numerical simulation of the joint or on experimental measurements. If the joint undergoes finite deformat...

  18. On Soccer Balls and Linearized Inverse Statistical Mechanics

    Science.gov (United States)

    von Brecht, James H.; Uminsky, David

    2012-12-01

    The classical inverse statistical mechanics question involves inferring properties of pairwise interaction potentials from exhibited ground states. For patterns that concentrate near a sphere, the ground states can range from platonic solids for small numbers of particles to large systems of particles exhibiting very complex structures. In this setting, previous work (von Brecht et al., Math. Models Methods Appl. Sci. 22, 2012) allows us to infer that the linear instabilities of the pairwise potential accurately characterize the resulting nonlinear ground states. Potentials with a small number of spherical harmonic instabilities may produce very complex patterns as a result. This leads naturally to the linearized inverse statistical mechanics question: given a finite set of unstable modes, can we construct a potential that possesses precisely these linear instabilities? If so, this would allow for the design of potentials with arbitrarily intricate spherical symmetries in the ground state. In this paper, we solve our linearized inverse problem in full, and present a wide variety of designed ground states.

  19. Joint Acoustic and Modulation Frequency

    Directory of Open Access Journals (Sweden)

    Les Atlas

    2003-06-01

    Full Text Available There is a considerable evidence that our perception of sound uses important features which is related to underlying signal modulations. This topic has been studied extensively via perceptual experiments, yet there are few, if any, well-developed signal processing methods which capitalize on or model these effects. We begin by summarizing evidence of the importance of modulation representations from psychophysical, physiological, and other sources. The concept of a two-dimensional joint acoustic and modulation frequency representation is proposed. A simple single sinusoidal amplitude modulator of a sinusoidal carrier is then used to illustrate properties of an unconstrained and ideal joint representation. Added constraints are required to remove or reduce undesired interference terms and to provide invertibility. It is then noted that the constraints would also apply to more general and complex cases of broader modulation and carriers. Applications in single-channel speaker separation and in audio coding are used to illustrate the applicability of this joint representation. Other applications in signal analysis and filtering are suggested.

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

    Science.gov (United States)

    Robinson, Garry; Robinson, Ian

    2013-07-01

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

  1. Effect of irradiation on the healing of extraction sockets in diabetic rats

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Il Joong; Hwang, Eui Hwan; Lee, Sang Rae [Kyunghee University College of Medicine, Seoul (Korea, Republic of)

    2003-03-15

    To observe the histologic pattern of healing in molar tooth extraction sockets of streptozotocin-induced diabetic rats following irradiation. Mature Sprague-Dawley rats were divided into three groups: control, diabetic, and diabetic-irradiated groups. Diabetes mellitus was induced by injecting streptozotocin. Control rats were injected with a citrate buffer only. After 5 days, the right maxillary first molar was extracted under general anesthesia from each of the rats. After the extraction, rats in the diabetic-irradiated group were irradiated with a single absorbed dose of 10 Gy to the head and neck region. The rats were killed at 1, 3, 7, 14, 21, and 28 days after treatment. Tissue sections were stained with hematoxylin-eosin and Masson's trichrome. In the diabetic and diabetic-irradiated groups, the early healing process of the socket extraction was similar to the control group, but bone formation was delayed at 7 days after the treatment. In the diabetic-irradiated group, alveolar bone surrounding the extraction socket showed sighs of necrosis at 3 days after treatment, and hemorrhage was observed in connective tissue within the extraction socket at 14 days after treatment. The experiment revealed that the healing process of the extraction socket was severely delayed and retarded by irradiation in the diabetic state.

  2. Can tert-butylhydroquinone improve the healing of extracted tooth socket in rats?

    Science.gov (United States)

    Tusi, Somayeh Khoramian; Manesh, Tahereh Eslam; Fathollahi, Mahmood Sheikh; Bagherian, Ali

    2017-01-01

    Background: Tooth extraction causes an open wound in the soft and hard tissues. During the inflammatory phase of the healing process, a large amount of free radicals are produced and cause oxidative stress, which leads to tissue damage and delayed wound healing. Thus, in this study, we evaluated the effect of tert-butylhydroquinone (TBHQ), as an antioxidant, on the healing process of tooth sockets in rats. Materials and Methods: To conduct this experimental study, male Wistar rats (n = 42) were divided into two groups. In each case, one upper second molar was extracted under general anesthesia. After the extraction, the tooth sockets of the experimental group were treated with a 0.02% TBHQ solution (0.1 ml) while the same volume of distilled water placed in the sockets of the control group. On days 3, 7, and 21 postoperatively, 7 rats from each group were euthanized, and histological slides were prepared from their tooth sockets. The prepared slides were examined histopathologically using a light microscope and compared using an independent two-sample t-test. The significance level was set at 0.05. Results: In the experimental group, a statistically significant (P = 0.003) increase in granulation tissue was observed on day 3, in comparison to the control group. The extent of bony trabeculation was also significantly higher in the TBHQ-treated group than in the control group on day 21 (P healing of the hard tissue in the tooth sockets.

  3. Effects of metallic nanoparticle doped flux on the interfacial intermetallic compounds between lead-free solder ball and copper substrate

    Energy Technology Data Exchange (ETDEWEB)

    Sujan, G.K., E-mail: sgkumer@gmail.com; Haseeb, A.S.M.A., E-mail: haseeb@um.edu.my; Afifi, A.B.M., E-mail: amalina@um.edu.my

    2014-11-15

    Lead free solders currently in use are prone to develop thick interfacial intermetallic compound layers with rough morphology which are detrimental to the long term solder joint reliability. A novel method has been developed to control the morphology and growth of intermetallic compound layers between lead-free Sn–3.0Ag–0.5Cu solder ball and copper substrate by doping a water soluble flux with metallic nanoparticles. Four types of metallic nanoparticles (nickel, cobalt, molybdenum and titanium) were used to investigate their effects on the wetting behavior and interfacial microstructural evaluations after reflow. Nanoparticles were dispersed manually with a water soluble flux and the resulting nanoparticle doped flux was placed on copper substrate. Lead-free Sn–3.0Ag–0.5Cu solder balls of diameter 0.45 mm were placed on top of the flux and were reflowed at a peak temperature of 240 °C for 45 s. Angle of contact, wetting area and interfacial microstructure were studied by optical microscopy, field emission scanning electron microscopy and energy-dispersive X-ray spectroscopy. It was observed that the angle of contact increased and wetting area decreased with the addition of cobalt, molybdenum and titanium nanoparticles to flux. On the other hand, wettability improved with the addition of nickel nanoparticles. Cross-sectional micrographs revealed that both nickel and cobalt nanoparticle doping transformed the morphology of Cu{sub 6}Sn{sub 5} from a typical scallop type to a planer one and reduced the intermetallic compound thickness under optimum condition. These effects were suggested to be related to in-situ interfacial alloying at the interface during reflow. The minimum amount of nanoparticles required to produce the planer morphology was found to be 0.1 wt.% for both nickel and cobalt. Molybdenum and titanium nanoparticles neither appear to undergo alloying during reflow nor have any influence at the solder/substrate interfacial reaction. Thus, doping

  4. DERIVATIVES OF HARMONIC MIXED NORM AND BLOCH-TYPE SPACES IN THE UNIT BALL OF Rn

    Institute of Scientific and Technical Information of China (English)

    Tang Xiaomin; Hu Zhangjian; Lu Xiaofen

    2011-01-01

    Let H(B) be the set of all harmonic functions f on the unit ball B of Rn.For 0 < p,q ≤ ∞ and a normal weight φ, the mixed norm space Hp,q,φ(B) consists of all functions f in H(B) for which the mixed norm ||·||p,q,φ < ∞. In this article, we obtain some characterizations in terms of radial, tangential, and partial derivative norms in Hp,q,φ(B).The parallel results for the Bloch-type space are also obtained. As an application, the analogous problems for polyharmonic functions are discussed.

  5. Coexistence of bounded and unbounded motions in a bouncing ball model

    Science.gov (United States)

    Marò, Stefano

    2013-05-01

    We consider the model describing the vertical motion of a ball falling with constant acceleration on a wall and elastically reflected. The wall is supposed to move in the vertical direction according to a given periodic function f. We apply the Aubry-Mather theory to the generating function in order to prove the existence of bounded motions with prescribed mean time between the bounces. As the existence of unbounded motions is known, it is possible to find a class of functions f that allow both bounded and unbounded motions.

  6. The Equivalence of BMOA and VMOA on the Unit Ball of Cn

    Institute of Scientific and Technical Information of China (English)

    DongshengLiu

    1999-01-01

    In this paper, we characterize BMOA and VMOA on the unit ball in terms of normsNp(f)=sup/x∈B{1/σ(Q(z))∫Q(z)│f(ξ)-f(z)│pdσ(ξ)}1/p,1≤p<∞ and more general Garcia norms.Where Q(z)=Q(n(z),δz)={ξ∈S,│1/2<δZ}.n(z)={e1,z=0,/z/│z│,z=0,δz=[2(1-│z│)]1/2.

  7. An evaluation of computer aided design of below-knee prosthetic sockets.

    Science.gov (United States)

    Topper, A K; Fernie, G R

    1990-12-01

    Forty-eight below-knee amputees compared sockets designed using CANFIT computer aided design (CAD) software with sockets designed using conventional methods. Each subject was fitted by one prosthetist who used conventional techniques and one who used the CANFIT system to design the socket. Prosthetists alternated design methods for each new subject. The prosthetist using the conventional techniques was allowed up to 2 design attempts and the prosthetist using the CANFIT system was allowed up to 5 design attempts. After 2 design attempts with each method 21% of the subjects preferred the CANFIT design socket. Following up to 5 attempts 54% preferred the CANFIT designed socket. A jury of experts made an assessment of the CANFIT system and of CAD in prosthetics. The jury did not think that the version of the system tested was cost effective but that at the rate that it was improving it would become such within 3 to 5 years. The jury noted that, as well as monetary benefits, CAD presents the possibility of benefits in other areas such as research and teaching. A number of specific suggestions regarding the use and development of CAD in prosthetics were also made.

  8. Piezoelectric bimorphs' characteristics as in-socket sensors for transfemoral amputees.

    Science.gov (United States)

    El-Sayed, Amr M; Hamzaid, Nur Azah; Abu Osman, Noor Azuan

    2014-12-10

    Alternative sensory systems for the development of prosthetic knees are being increasingly highlighted nowadays, due to the rapid advancements in the field of lower limb prosthetics. This study presents the use of piezoelectric bimorphs as in-socket sensors for transfemoral amputees. An Instron machine was used in the calibration procedure and the corresponding output data were further analyzed to determine the static and dynamic characteristics of the piezoelectric bimorph. The piezoelectric bimorph showed appropriate static operating range, repeatability, hysteresis, and frequency response for application in lower prosthesis, with a force range of 0-100 N. To further validate this finding, an experiment was conducted with a single transfemoral amputee subject to measure the stump/socket pressure using the piezoelectric bimorph embedded inside the socket. The results showed that a maximum interface pressure of about 27 kPa occurred at the anterior proximal site compared to the anterior distal and posterior sites, consistent with values published in other studies. This paper highlighted the capacity of piezoelectric bimorphs to perform as in-socket sensors for transfemoral amputees. However, further experiments are recommended to be conducted with different amputees with different socket types.

  9. Piezoelectric Bimorphs’ Characteristics as In-Socket Sensors for Transfemoral Amputees

    Directory of Open Access Journals (Sweden)

    Amr M. El-Sayed

    2014-12-01

    Full Text Available Alternative sensory systems for the development of prosthetic knees are being increasingly highlighted nowadays, due to the rapid advancements in the field of lower limb prosthetics. This study presents the use of piezoelectric bimorphs as in-socket sensors for transfemoral amputees. An Instron machine was used in the calibration procedure and the corresponding output data were further analyzed to determine the static and dynamic characteristics of the piezoelectric bimorph. The piezoelectric bimorph showed appropriate static operating range, repeatability, hysteresis, and frequency response for application in lower prosthesis, with a force range of 0–100 N. To further validate this finding, an experiment was conducted with a single transfemoral amputee subject to measure the stump/socket pressure using the piezoelectric bimorph embedded inside the socket. The results showed that a maximum interface pressure of about 27 kPa occurred at the anterior proximal site compared to the anterior distal and posterior sites, consistent with values published in other studies. This paper highlighted the capacity of piezoelectric bimorphs to perform as in-socket sensors for transfemoral amputees. However, further experiments are recommended to be conducted with different amputees with different socket types.

  10. EFFECTIVENESS OF TRUNK TRAINING EXERCISES VERSUS SWISS BALL EXERCISES FOR IMPROVING SITTING BALANCE AND GAIT PARAMETERS IN ACUTE STROKE SUBJECTS

    Directory of Open Access Journals (Sweden)

    Kothalanka Viswaja

    2015-12-01

    Full Text Available Background: The aim of this study is to evaluate the effectiveness of trunk training and Swiss ball exercises in acute stroke subjects. Trunk is often neglected part in the stroke rehabilitation, trunk training exercises and Swiss ball exercises result in better recruitment of trunk muscles thus improving sitting balance and gait parameters in acute stroke subjects. However literature evidences for trunk training exercises and Swiss ball exercises in improving sitting balance and gait are scarce in acute stroke population. Methods: A total of 60 subjects who met the inclusion criteria were recruited from department of physiotherapy, G.S.L general hospital and were randomly allocated into 2 groups with 30 subjects in each group. Initially all of them were screened for balance and gait using trunk impairment scale and by assessing gait parameters, after that they were given a 30min of trunk training and Swiss ball exercises for 5 days a week for 4 weeks. Both the groups received conventional physiotherapy for 4 weeks. Results: Post intervention there was no significant difference between the two groups. There was improvement post treatment in trunk training group (P0.5. Conclusion: The results had shown that both groups noted significant difference. But when comparing between these two groups there is no statistical significance noted. So this study concluded that there is no significant difference between trunk training exercises and Swiss ball exercises on sitting balance and gait parameters in subjects with stroke.

  11. Simple Communication Based on SOCKET%基于SOCKET的简单通信

    Institute of Scientific and Technical Information of China (English)

    洪永新

    2014-01-01

    介绍了如何创建套接字,如何连接套接字以及如何共享数据,以便进行socket通信,主要是用Ruby编程语言进行创建的,而且并不是仅仅要是Ruby所提供的套接字API的包装类(wrap class),而是先讲解低层次的API。然后再介绍Ruby的包装类,使你对套接字的理解不仅仅局限在Ruby。%The article mainly introduces how to create a socket to socket,and how to share data,in order to carry out socket communication,is mainly used Rubyprogramming language was created,and not only if the socket API Ruby provided by the wrapper class (wrapclass),but to explain the lower level API.And thenintroduces the Ruby wrapper classes,enable you to the understanding of the socket is not limited in Ruby.

  12. On Implementation of Bidirectional Real-time Communication between Server and Browser Based on Socket.IO Framework%基于Socket.IO框架的服务器与浏览器双向实时通信的实现

    Institute of Scientific and Technical Information of China (English)

    陈希球

    2016-01-01

    Node.js是全球最受欢迎的Web应用开发平台,它采用模块式的开源框架结构,聚集了众多的开发资源,其中socket.io模块封装了网络底层通信,支持多种网络通信协议,易于实现跨浏览器通信.通过分析socket.io模块的通信功能,实现了服务器与浏览器之间的双向通信,并说明了编程方法.

  13. The Power of a Soccer Ball: A Traumatic Open Finger Dislocation—A Rare Case Presentation

    Directory of Open Access Journals (Sweden)

    Turan Cihan Dülgeroğlu

    2015-01-01

    Full Text Available Proximal interphalangeal joint dislocations are injuries observed frequently and caused by axial loading on the finger in the extension. In this paper we present a traumatic open finger dislocation due to a ball hitting a wrestler. It was successfully treated with reduction and the volar plate and collateral bond fixation were applied with absorbable sutures.

  14. Investigation on the Surface Coating of Grinding Balls

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The surface coating of grinding balls was investigated experimentally. The results show that a coating may form on the surface of grinding balls when Cr or Al powders are subjected to ball grinding. The plastic deformation of the ball surface plays an important role during the coating formation, and the strong binding force between the powders and the balls is a necessary pre-condition. The thickness of coating increases with the plasticity of the powders and the balls. Annealing the balls with coating will result in an obvious diffusion of the elements in the bonding zone of inter-face.

  15. Clinical safety and efficacy of implantation of octacalcium phosphate collagen composites in tooth extraction sockets and cyst holes

    Directory of Open Access Journals (Sweden)

    Tadashi Kawai

    2016-09-01

    Full Text Available It was demonstrated that octacalcium phosphate collagen composite achieved notable bone regeneration in bone defects in preclinical studies. On the basis of the research results, an investigator-initiated exploratory clinical trial was conducted after approval from a local Institutional Review Board. This clinical study was performed as a single-arm non-randomized intervention study. Octacalcium phosphate collagen composite was implanted into a total of 10 cases of alveolar bone defects after tooth extractions and cystectomy. Safety assessment was performed in terms of the clinical course and several consecutive laboratory examinations, and sequential radiographs were used for efficacy assessment. All participants uneventfully completed the clinical trial without major problems in their general condition. Postoperative wound swelling was observed, as also commonly seen in tooth extraction or cystectomy. Although no serious liver dysfunction, renal dysfunction, electrolyte imbalance, or abnormal urinalysis results were recognized, the number of white blood cells and C-reactive protein level temporarily increased after the operation. An increase in radiopacity in the octacalcium phosphate collagen composite–implanted site was observed in all cases. Finally, the border between the original bone and the octacalcium phosphate collagen composite–implanted site became indistinguishable. These results suggest that octacalcium phosphate collagen composite could be utilized safely in clinical situations in the future.

  16. BIOMECHANICS AND PATHOMECHANICS OF THE PATELLOFEMORAL JOINT.

    Science.gov (United States)

    Loudon, Janice K

    2016-12-01

    The patellofemoral joint is a joint that can be an area of concern for athletes of various sports and ages. The joint is somewhat complex with multiple contact points and numerous tissues that attach to the patella. Joint forces are variable and depend on the degree of knee flexion and whether the foot is in contact with the ground. The sports medicine specialist must have a good working knowledge of the anatomy and biomechanics of the patellofemoral joint in order to treat it effectively.

  17. 基于非对称balls-into-bins的高效平衡负载分配模型%An efficient and balanced load allocation model based on non-uniform balls-into-bins

    Institute of Scientific and Technical Information of China (English)

    皇甫先鹏; 罗雪山

    2013-01-01

    在大规模数据中心和P2P覆盖网络等复杂网络负载平衡分配中,前人提出了多种多样的负载分配方法,但许多方法为了达到更好的平衡负载指标,追求越来越复杂的算法,使得时间复杂度和算法复杂度很难控制在合理的范围之内.本文在研究了经典balls-into-bins、Azar balls-into-bins和balls into non-uniform bins等模型的基础上,提出了一种新颖高效的非对称balls-into-bins平衡负载分配模型,该模型具有异构的balls、异构的bins,以及不同的bin选择概率,能以很高的概率将最大负载均衡地控制在合理的范围内,通信负载很小,且具有很好的可扩展性,通过拓展,该模型在负载平衡的诸多领域都将有广阔的应用空间.%In balanced load allocation problem in complex systems like large-scale data center and P2P overlay network,the various load allocation methods is proposed.In order to achieve better balanced load index,many methods,however,are in pursuit of more and more complicated algorithms,which makes the time and algorithm complexity hard to control.Based on the study of the original balls-into-bins model,Azar balls-into-bins model and balls into non-uniform bins model,the paper brings forward an efficient and balanced non-uniform balls-into-bins load allocation model,which is provided with heterogeneous balls,heterogeneous bins and different bin selection probabilities.The model can achieve rational largest load with high probabilities,at the cost of little time and algorithm complexity.The model is extensible and can be applied in many domains.

  18. The Transmission Interfaces Contribute Asymmetrically to the Assembly and Activity of Human P-glycoprotein.

    Science.gov (United States)

    Loo, Tip W; Clarke, David M

    2015-07-01

    P-glycoprotein (P-gp; ABCB1) is an ABC drug pump that protects us from toxic compounds. It is clinically important because it confers multidrug resistance. The homologous halves of P-gp each contain a transmembrane (TM) domain (TMD) with 6 TM segments followed by a nucleotide-binding domain (NBD). The drug- and ATP-binding sites reside at the interface between the TMDs and NBDs, respectively. Each NBD is connected to the TMDs by a transmission interface involving a pair of intracellular loops (ICLs) that form ball-and-socket joints. P-gp is different from CFTR (ABCC7) in that deleting NBD2 causes misprocessing of only P-gp. Therefore, NBD2 might be critical for stabilizing ICLs 2 and 3 that form a tetrahelix bundle at the NBD2 interface. Here we report that the NBD1 and NBD2 transmission interfaces in P-gp are asymmetric. Point mutations to 25 of 60 ICL2/ICL3 residues at the NBD2 transmission interface severely reduced P-gp assembly while changes to the equivalent residues in ICL1/ICL4 at the NBD1 interface had little effect. The hydrophobic nature at the transmission interfaces was also different. Mutation of Phe-1086 or Tyr-1087 to arginine at the NBD2 socket blocked activity or assembly while the equivalent mutations at the NBD1 socket had only modest effects. The results suggest that the NBD transmission interfaces are asymmetric. In contrast to the ICL2/3-NBD2 interface, the ICL1/4-NBD1 transmission interface is more hydrophilic and insensitive to mutations. Therefore the ICL2/3-NBD2 transmission interface forms a precise hydrophobic connection that acts as a linchpin for assembly and trafficking of P-gp.

  19. An On-Line Algorithm for Measuring the Translational and Rotational Velocities of a Table Tennis Ball

    Science.gov (United States)

    Liu, Chunfang; Hayakawa, Yoshikazu; Nakashima, Akira

    This paper proposes an on-line method for estimating both translational and rotational velocities of a table tennis ball by using only a few consecutive frames of image data which are sensed by two high speed cameras. In order to estimate the translational velocity, three-dimensional (3D) position of the ball's center at each instant of camera frame is obtained, where the on-line method of reconstructing the 3D position from the two-dimensional (2D) image data of two cameras is proposed without the pattern matching process. The proposed method of estimating the rotational velocity belongs to the image registration methods, where in order to avoid the pattern matching process too, a rotation model of the ball is used to make an estimated image data from an image data sensed at the previous instant of camera frame and then the estimated image data are compared with the image data sensed at the next instant of camera frame to obtain the most plausible rotational velocity by using the least square and the conjugate gradient method. The effectiveness of the proposed method is shown by some experimental results in the case of a ball rotated by a rotation machine as well as in the case of a flying ball shot from a catapult machine.

  20. Programming Technology of IP Multicast and Broadcast Based on Socket%基于套接字的IP多目通信及广播通信编程技术

    Institute of Scientific and Technical Information of China (English)

    李冬霞; 苏广川; 沈瑛

    2001-01-01

    Beginning with the simple introduction of socket which is the most commonly used application program interfaces in UNIX/LINUX communication domain, the concrete programming procedures to realize multicast and broadcast based on socket is provided, according to TCP/IP protocol in LINUX system. The acquiring and converting of broadcast destination address and multicast address, the setting of multicast options, the joining in and withdrawing from the multicast group, and the receiving and sending of datagram are all demonstrated in it, the related system calls and simple explication of C programming are also included.%简单介绍了UNIX/LINUX通信域中最常用的应用程序接口——套接字,在此基础上,详细描述了在LINUX系统中按照TCP/IP协议,实现基于套接字的多目通信、广播通信的具体编程步骤,包括广播目的地址、多目地址的获取与转换,多目通信中特征选项的设置,多目组的加入与退出,报文的发送与接收等,同时也给出了相关的系统调用及程序段说明.

  1. Structural transition and softening in Al–Fe intermetallic compounds induced by high energy ball milling

    Energy Technology Data Exchange (ETDEWEB)

    Basariya, M. Raviathul, E-mail: ravia80@gmail.com [CSIR-National Metallurgical Laboratory, Jamshedpur 831007 (India); Department of Metallurgical Engineering, Indian Institute of Technology (BHU), Varanasi 221005 (India); Roy, Rajat K.; Pramanick, A.K.; Srivastava, V.C. [CSIR-National Metallurgical Laboratory, Jamshedpur 831007 (India); Mukhopadhyay, N.K. [Department of Metallurgical Engineering, Indian Institute of Technology (BHU), Varanasi 221005 (India)

    2015-06-25

    In the present investigation, powders of as-cast ingots of Al–25 at%Fe and Al–34.5 at%Fe alloys close to Al{sub 3}Fe and Al{sub 2}Fe intermetallic phases are subjected to high energy ball milling to understand the possibility of formation of amorphous and/or nanocrystalline phases or any other metastable phases. The development of microstructure, evolution of various metastable phases and their stability are investigated by x-ray diffraction (XRD) and transmission electron microscopy (TEM) techniques. Mechanical milling of the alloys, up to 50 h, was carried out in high energy planetary ball mill. It resulted in phase transformation from monoclinic and triclinic structures of Al{sub 3}Fe and Al{sub 2}Fe, respectively, to orthorhombic structure pertaining to Al{sub 5}Fe{sub 2} phase and structural transformation from crystalline to amorphous phase. Hardness measurements revealed a transition from hardening to softening behavior in these mechanically milled alloys undergoing prolonged milling. The softening effect in the milled powders, having a composite structure involving nanocrystalline and amorphous phases, is attributed to the competing phenomenon of grain size reduction and amorphous phase formation with increasing milling time.

  2. Both anticipatory and compensatory postural adjustments are adapted while catching a ball in unstable standing posture.

    Science.gov (United States)

    Scariot, Vanessa; Rios, Jaqueline L; Claudino, Renato; dos Santos, Eloá C; Angulski, Hanna B B; dos Santos, Marcio J

    2016-01-01

    The main objective of this study was to analyze the role of balance exercises on anticipatory (APA) and compensatory (CPA) postural adjustments in different conditions of postural stability. Sixteen subjects were required to catch a ball while standing on rigid floor, trampoline and foam cushion surfaces. Electromyographic activities (EMG) of postural muscles were analyzed during time windows typical for APAs and CPAs. Overall there were a reciprocal activation of the muscles around the ankle and co-activations between ventral and dorsal muscles of the thigh and trunk during the catching a ball task. Compared to the rigid floor, the tibialis anterior activation was greater during the trampoline condition (CPA: p = 0.006) and the soleus muscle inhibition was higher during foam cushion condition (APA: p = 0.001; CPA: p = 0.007). Thigh and trunk muscle activities were similar across the conditions. These results advance the knowledge in postural control during body perturbations standing on unstable surfaces.

  3. Homogeneity of ball milled ceramic powders: Effect of jar shape and milling conditions

    Directory of Open Access Journals (Sweden)

    M. Broseghini

    2017-02-01

    Full Text Available This paper contains data and supporting information of and complementary to the research article entitled “Effect of jar shape on high-energy planetary ball milling efficiency: simulations and experiments” (Broseghini et al., [1]. Calcium fluoride (CaF2 was ground using two jars of different shape (cylindrical and half-moon installed on a planetary ball-mill, exploring different operating conditions (jar-to-plate angular velocity ratio and milling time. Scanning Electron Microscopy (SEM images and X-Ray Powder Diffraction data (XRPD were collected to assess the effect of milling conditions on the end-product crystallite size. Due to the inhomogeneity of the end product, the Whole Powder Pattern Model (WPPM, (Scardi, 2008 [2] analysis of XRPD data required the hypothesis of a bimodal distribution of sizes – respectively ground (fine fraction and less-to-not ground (coarse fraction – confirmed by SEM images and suggested by the previous literature (Abdellatief et al., 2013 [3,4]. Predominance of fine fraction clearly indicates optimal milling conditions.

  4. 基于单片机的简易定时开关插座的设计与制作%Design and making of simple microcontroller based on the timer switch socket

    Institute of Scientific and Technical Information of China (English)

    陆仁超

    2015-01-01

    The use of AT89S52 microcontroller to design and produce a simple timer switch socket. The circuit is composed of a power supply circuit, minimum system microcontroller, digital display and button operation circuit, relay power control circuit is composed of four modules, and test with software and hardware. To achieve timing within 24 hours of the time of the products, the time to automatically cut off the power supply circuit power socket, some can not long time can play a protective role, but also can be used as a timing controller.%使用AT89S52单片机设计并制作一个简易型定时开关插座。电路由电源电路、单片机最小系统、数码显示和按键操作电路、继电器强电控制电路四个模块组成,并使用软件和硬件进行测试。本产品能实现24小时内的时间定时,并自动断电,对一些不能长时间通电的电路能够起到保护作用,也可以作为定时控制器使用。

  5. Synthesis and Characterizations of Nanocrystalline WC-Co Composite Powders by a Unique Ball Milling Process

    Institute of Scientific and Technical Information of China (English)

    Jun SHEN; Jianfei SUN; Faming ZHANG

    2004-01-01

    In order to explore the high efficiency of fabricating nanocrystalline WC-Co composite powders, this paper presented a unique high energy ball milling process with variable rotation rate and repeatious circulation, by which nanocrystalline WC-10Co0.8VC-0.2Cr3C2 (wt pct) composite powders with mean grain size of 25 nm were prepared in 32 min, and the quantity of the powders for a batch was as much as 800 grams. The as-prepared powders were analyzed and characterized by chemical analysis,X-ray diffraction (XRD), transmission electron microscopy (TEM) and differential thermal analysis (DTA). The results show that high energy ball milling with variable rotation rates and repeatious circulation could be used to produce nanocrystalline WC-Co powder composites with high efficiency. The compositions of the powders meet its specifications with low impurity content. The mean grain size decreases, lattice distortion and system energy increase with increasing the milling time. The morphology of nanocrystalline WC-Co particles displays dominantly sphere shape and their particle sizes are all lower than 80nm. The eutectic temperature of the nanocrystalline WC-10Co-0.8VC-0.2Cr3C2 composites is about 1280℃.

  6. Effect of ball milling energy on rheological and thermal properties of amaranth flour.

    Science.gov (United States)

    Roa, Diego F; Baeza, Rosa I; Tolaba, Marcela P

    2015-12-01

    Pearled amaranth grains obtained by abrasive milling were processed by planetary ball milling to produce amaranth flours. The influence of milling energy on rheological and thermal behavior of amaranth flour dispersions and stability during 24 h storage at 4 °C were investigated based on a factorial design. The rheological behavior of flour dispersions (4 % and 8 % w/v) was determined using a rotational viscometer, while gelatinization degree was determined by differential scanning calorimetry as a measure of structural changes.The power law model was found to be suitable in expressing the relationship between shear stress and shear rate. Flour dispersions showed a pseudoplastic behavior. However this character decreased with the storage being dependent on flour concentration and milling energy. A decrease of the consistency index and an increase of the flow behavior index were observed as a result of the increasing milling energy. Gelatinization enthalpy decrease showed the loss of crystalline structure due to ball milling. Amaranth flour dispersions presented increasing stability during storage. It was observed, that the stability changed with the concentration of amaranth flours.Thus, more stable dispersions were obtained as the flour concentration increased. The highly milled sample was the most stable sample during the storage.

  7. Plasma nitriding of AISI 52100 ball bearing steel and effect of heat treatment on nitrided layer

    Indian Academy of Sciences (India)

    Ravindra Kumar; J Alphonsa; Ram Prakash; K S Boob; J Ghanshyam; P A Rayjada; P M Raole; S Mukherjee

    2011-02-01

    In this paper an effort has been made to plasma nitride the ball bearing steel AISI 52100. The difficulty with this specific steel is that its tempering temperature (∼170–200°C) is much lower than the standard processing temperature (∼460–580°C) needed for the plasma nitriding treatment. To understand the mechanism, effect of heat treatment on the nitrided layer steel is investigated. Experiments are performed on three different types of ball bearing races i.e. annealed, quenched and quench-tempered samples. Different gas compositions and process temperatures are maintained while nitriding these samples. In the quenched and quench-tempered samples, the surface hardness has decreased after plasma nitriding process. Plasma nitriding of annealed sample with argon and nitrogen gas mixture gives higher hardness in comparison to the hydrogen–nitrogen gas mixture. It is reported that the later heat treatment of the plasma nitrided annealed sample has shown improvement in the hardness of this steel. X-ray diffraction analysis shows that the dominant phases in the plasma nitrided annealed sample are (Fe2−3N) and (Fe4N), whereas in the plasma nitrided annealed sample with later heat treatment only -Fe peak occurs.

  8. Magnetic and Magnetocaloric Properties of High-Energy Ball-Milled Nanocrystalline CeMn2Ge2 Compound

    Science.gov (United States)

    Kaya, Melike; Dincer, Ilker; Akturk, Selcuk; Elerman, Yalcin

    2016-10-01

    CeMn2Ge2 nanopowders have been obtained by high-energy ball milling for 5 and 10 hours from bulk compound to investigate the effect of milling time on magnetic and magnetocaloric properties. CeMn2Ge2 nanopowders have been characterized by X-ray diffraction (XRD), scanning electron microscopy with energy-dispersive X-ray spectroscopy, transmission electron microscopy, and magnetization measurements. The average grain size of the nanoparticles from XRD measurements is about 12.2 and 8 nm for 5-hour and 10-hour ball-milled samples, respectively. The investigations reveal that magnetic entropy change (∆ S m) can be altered by changing the particle size of the compound. Maximum ∆ S m is -2.45 and -1.30 J kg-1 K-1 for the 5- and 10-hour ball-milled nanopowders, respectively.

  9. Magnetic properties of ball-milled TbFe2 and TbFe2B

    Indian Academy of Sciences (India)

    J Arout Chelvane; S Kasiviswanathan; M V Rao; G Markandeyulu

    2004-04-01

    The magnetic properties of ball-milled TbFe2 and TbFe2B were studied by magnetization measurements. X-ray diffraction studies on TbFe2B showed that boron occupied interstitial position in the crystal structure, just as hydrogen did. The value of the saturation magnetization of TbFe2B was found to be smaller than that of TbFe2. This is explained on the basis of a charge transfer between the boron atoms and the 3d band of Fe. The anisotropy of TbFe2B was found to be large compared to that of TbFe2. X-ray diffractograms for the ball milled samples showed that after 80 h of milling, a predominantly amorphous phase was obtained. TbFe2B was found to undergo easy amorphization compared to TbFe2. Magnetization of TbFe2 was found to decrease rapidly with initial milling hours and was found to be constant with further hours of milling. TbFe2B exhibited an anomalous behaviour with an increase in moment with milling hours and this may be due to the segregation of -Fe.

  10. PENGEMBANGAN AROMA DAN CITA RASA BAKSO DENGAN MENGGUNAKAN FLAVOR [Development of Aroma and Taste of Meat Ball Using Flavor

    Directory of Open Access Journals (Sweden)

    Aulia 2

    2001-08-01

    Full Text Available Bakso is one of the most popular meat product in Indonesia. This research studied of effect of addition of falvor to the quality of meat ball. The analysis included physical characteristics (specific gravity, hardness, shear, elasticity and color organoleptic test. The results showed that : according to consumer preference, the most like flavour that added in the meat ball were the flavour of beef Q. 1.%, beef Q 1.5%, Beef WIN 1.5% and beef Fat WIN 1.0%. the use of flavor did not cause differences in physical characteristics like specific gravity, hardness, shear, alasticity and color a-value. The use flavour in creased the price of bakso between Rp 4.5,- to Rp 18,-. According to comparison test, meat ball with beef Q 1.5% has the best score compared with Bakso Lapang Tembak (BLT in aroma, and with Bakso Pedagang Keliling (BPK has the best score in aroma, test and texture.

  11. Combined oculoplastic operation for contracted conjunctival sac and depressed eye socket of anophthalmos%Ⅱ期眼窝凹陷及结膜囊狭窄的联合整复手术

    Institute of Scientific and Technical Information of China (English)

    张向荣; 周琼; 裴重刚; 周荃; 高长华

    2011-01-01

    目的 探讨眼球摘除或眼内容物剜出术后眼窝内陷伴结膜囊狭窄的同期整复手术方法及临床疗效。方法 对2007年8月至2010年5月收治35例患者施行Ⅱ期义眼座植入联合结膜囊成形术,其中7例结膜囊轻度缺损采用下、上穹窿结膜划开;23例结膜囊中度缺损采用异体巩膜;5例结膜囊重度缺损采用自体唇粘膜移植。所有病例结膜囊内眼模支撑,轻、中度组行睑缘临时缝合,术后1月拆线,自体唇黏膜移植组行部分睑缘粘连术,术后3个月分开眼睑,试装义眼。观察术后眼窝内陷矫正、结膜囊成形情况。随访3~6月。结果 术后所有患者眼窝内陷明显改善,结膜囊成形良好,穹窿深浅可,均可配戴适合的义眼,活动度可。结论 Ⅱ期义眼座植入联合结膜囊成形术是治疗眼球摘除或眼内容物剜出术后眼窝内陷伴结膜囊狭窄的理想手术。%Objective To explore combined oculoplastic surgery methods for treating narrow conjunctival sac and sunk socket after enucleation or evisceration. Methods Thirty-five cases with narrow conjunctival sac and sunk socket were treated with secondary hydroxyapatite or Medpor orbital implantation combined with plasty of the cul - de - sac. Seven cases with mild impairment were cut open the bottom or top of the conjunctival fomix, 23 patients with moderate impairment were repaired by preserved sclera conjunctival sac, 5 eases of severe conjunctival defect were repaired by autologous oral mucosa transplants. An eye substitute was put in the conjunctival sac in every case. In mild and moderate impairment groups temporary palpebral suture were done, the eyelids were opened lmonth after surgery. The superior and lower eyelids were closed with partial blepharorrhaphy in oral mucosa transplant groups and the eyelids were opened 3 months after surgery and a suitable prosthesis was implanted. We observed the rectified sunk socket, the shaping

  12. Ammonia Ball Inspection Repair and Accident Prevention%氨球的检验修理及事故预防

    Institute of Scientific and Technical Information of China (English)

    赖明秋

    2012-01-01

    Ammonia as a toxic media,the stored procedure of ammonia must prevent and put an end to leakage.This paper has completed hazard analysis of ammonia ball tank according to national laws and technical standards,and confirm that the ammonia ball tank is a major danger source.Ammonia ball inspects regularly and ensure the safety of ammonia spherical body.%氨作为一种有毒介质,其存储过程必须预防和杜绝泄露。本文针对氨球储罐,进行了危害分析,依据国家相应法律法规和技术标准,确定氨储罐为一级重大危险源。对氨球进行定期检验,修理,确保氨球本体安全。

  13. Kicking velocity and physical, technical, tactical match performance for U18 female football players - effect of a new ball

    DEFF Research Database (Denmark)

    Andersen, T. Bull; Bendixen, Mads; Pedersen, Jens Meldgaard

    2012-01-01

    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...... football games, and decrements in running performance occurred towards the end of games. The players kicked faster and reported lower muscular exertion during games played with a lighter smaller ball, but locomotor activities, heart rate and overall technical-tactical game performance remained unaffected....

  14. The Failure Models of Lead Free Sn-3.0Ag-0.5Cu Solder Joint Reliability Under Low-G and High-G Drop Impact

    Science.gov (United States)

    Gu, Jian; Lei, YongPing; Lin, Jian; Fu, HanGuang; Wu, Zhongwei

    2017-02-01

    The reliability of Sn-3.0Ag-0.5Cu (SAC 305) solder joint under a broad level of drop impacts was studied. The failure performance of solder joint, failure probability and failure position were analyzed under two shock test conditions, i.e., 1000 g for 1 ms and 300 g for 2 ms. The stress distribution on the solder joint was calculated by ABAQUS. The results revealed that the dominant reason was the tension due to the difference in stiffness between the print circuit board and ball grid array, and the maximum tension of 121.1 MPa and 31.1 MPa, respectively, under both 1000 g or 300 g drop impact, was focused on the corner of the solder joint which was located in the outmost corner of the solder ball row. The failure modes were summarized into the following four modes: initiation and propagation through the (1) intermetallic compound layer, (2) Ni layer, (3) Cu pad, or (4) Sn-matrix. The outmost corner of the solder ball row had a high failure probability under both 1000 g and 300 g drop impact. The number of failures of solder ball under the 300 g drop impact was higher than that under the 1000 g drop impact. The characteristic drop values for failure were 41 and 15,199, respectively, following the statistics.

  15. Prosthetic rehabilitation of an ocular defect with post-enucleation socket syndrome: A case report.

    Science.gov (United States)

    Amornvit, Pokpong; Rokaya, Dinesh; Shrestha, Binit; Srithavaj, Theerathavaj

    2014-01-01

    Ocular trauma can be caused by road traffic accidents, falls, assaults, or work-related accidents. Enucleation is often indicated after ocular injury or for the treatment of intraocular tumors, severe ocular infections, and painful blind eyes. Rehabilitation of an enucleated socket without an intraocular implant or with an inappropriately sized implant can result in superior sulcus deepening, enophthalmos, ptosis, ectropion, and lower lid laxity, which are collectively known as post-enucleation socket syndrome. This clinical report describes the rehabilitation of post-enucleation socket syndrome with a modified ocular prosthesis. Modifications to the ocular prosthesis were performed to correct the ptosis, superior sulcus deepening, and enophthalmos. The rehabilitation procedure produced satisfactory results.

  16. Doubts and Speculation of the Use of Stone Balls%石球用途的质疑与猜测

    Institute of Scientific and Technical Information of China (English)

    司新国

    2012-01-01

    The stone ball is one of common important stoneware types in the Paleolithic site. The stone ball is the first product of labor of Australopithecus undoubtedly, But we have no reason to think of the Australopithecus creating any objects as tools. Worship of the sun and the moon and the fruit may become the power of Australopithecus building stone balls.%石球是旧石器时代遗址中常见的、重要的石器类型之一。石球无疑是古猿的最初劳动产品,但我们没有理由把古猿创造的任何器物都视为工具。对日月的崇拜、对果实的崇拜有可能成为古猿打造石球的动力。

  17. Processing and microstructural characterization of a Ti-Cr-Nb alloy synthesized by high-energy ball-milling

    Directory of Open Access Journals (Sweden)

    José Fernando Ribeiro de Castro

    2012-10-01

    Full Text Available Ti-based body centered cubic (BCC solid solutions are promising materials for hydrogen storage. These alloys are usually synthesized by melting processes and have large amounts of vanadium as alloying element to stabilize the BCC phase at room temperature. In this work high energy ball-milling was evaluated as processing route for a Ti - based BCC solid solution. Moreover, the feasibility of Nb as stabilizer for the BCC phase is also investigated. The results show that the BCC phase is rapidly formed by ball-milling. After 2 hours of milling the alloy is mainly composed by BCC phase. Moreover, the time of milling must be limited in order to minimize the contamination with iron promoted by the wearing of milling balls and vials.

  18. Morphometric Changes of the Socket after Site Preservation Using Nanobone and Collagen Membrane or Stypro Versus Extraction Alone

    Directory of Open Access Journals (Sweden)

    Salahi S

    2015-06-01

    Full Text Available Statement of Problem: The long-term success of a dental implant relies on implant osseointegration into native and viable bone, implant placement in an ideal position, and optimal hard and soft tissue contour. This requires the presence of sufficient alveolar bone volume, good alveolar ridge (Practically with no sign of atrophy and good surgical technique. Objectives: The aim of this randomized controlled clinical study was to evaluate morphometric changes after different alveolar ridge preservation procedures. Materials and Methods: In this study, 33 patients who had single-rooted premolar, which needed to be extracted, were recruited. Patients were randomly divided into 3 groups and after tooth extraction the following treatments were administered: in group A: NanoBone and a collagen membrane; in group B: NanoBone and Stypro; and in group C: natural healing. The following clinical parameters were evaluated at baseline and 6 months after the extraction: buccolingual width, midbuccal height (with the use of a custom made stent and width of keratinized gingiva. For data analysis, Paired t-test,one-way ANOVA and Tukey’s tests were used. Results: The average reduction in the buccolingual width, midbuccal height and keratinized gingiva was as follows: group A: 1.18±0.6, 0.64±0.92 and 3.45±1.75 mm; group B: 2.18±0.75, 0.73±0.78 and 4.73±0.9 mm; and group C: 1±0.89, 2.36±1.21 and 5±0.63 mm, respectively. Moreover, a significantly reduced resorption was found in both the buccolingual width and the width of keratinized gingiva in group A as compared to groups B and C (p<0.05. Conclusions: This study showed that the use of collagen membrane+Nano bone (group A can significantly reduce the horizontal resorption of the alveolar ridge and keratinized tissue more effectively than stypro+Nano bone (group B and blood clot alone and natural healing (group C.

  19. Network Correlates of Sexual Health Advice Seeking and Substance Use among Members of the Los Angeles House and Ball Communities

    Science.gov (United States)

    Holloway, Ian W.; Schrager, Sheree M.; Wong, Carolyn F.; Dunlap, Shannon L.; Kipke, Michele D.

    2014-01-01

    House and Ball communities (HBCs), represent a prime context for human immunodeficiency virus prevention with African American young men who have sex with men and transgender persons. This study sought to understand the composition and function of social support and sexual networks of HBC members in Los Angeles, California (N = 263). Participants…

  20. HIV Prevention Service Utilization in the Los Angeles House and Ball Communities: Past Experiences and Recommendations for the Future

    Science.gov (United States)

    Holloway, Ian W.; Traube, Dorian E.; Kubicek, Katrina; Supan, Jocelyn; Weiss, George; Kipke, Michele D.

    2012-01-01

    African-American young men who have sex with men and transgender persons are at elevated risk for HIV infection. House and Ball communities, networks of mostly African-American gay, bisexual, and transgender individuals who compete in modeling and dance, represent a prime venue for HIV prevention with these difficult-to-reach populations; however,…