WorldWideScience

Sample records for rendezvous proximity operations

  1. Tools and Techniques for a Systematic Approach to Safe Rendezvous and Proximity Operations

    Science.gov (United States)

    Taylor, Rob; Rishikof, Brian

    2010-09-01

    Among the most demanding operations facing manned spaceflight is the ability to successfully and safely complete Rendezvous Proximity Operations & Capture(RPOC) operations with a target vehicle. While perhaps made to look routine from a safety perspective for some vehicles and developers regularly docking to the International Space Station(namely the Space Shuttle, and Russian Progress and Soyuz vehicles), international partners and commercial vehicle developers are finding it among the most difficult engineering challenges. Whether docking with the International Space Station in low earth orbit, or rendezvousing with a returning spacecraft in low lunar orbit, successfully and systematically accounting for all the combinations of risks and failures which lead to failed rendezvous or collisions can be daunting. Systems such as propulsion, avionics, software, and command and data handling(C&DH) must all work as a single integrated system; and the guidance, navigation, and control(GN&C) systems arguably forms the heart of that unit. In response to this challenge, Odyssey Space Research(Odyssey) utilizes their core GN&C engineering competencies, systems engineering capabilities and associated simulation tools to address the safety of RPOC. These simulations provide for high-level mission scenario analysis, systems design, mission planning, monitoring, and implementation, covering all flight phases of rendezvous from orbit insertion, phasing and transfer orbits, far-range rendezvous operations, proximity operations, and capture. Combined with a systems engineering approach, it allows our team to analyze functional system capabilities, propose design modifications and then perform the safety engineering aspect of evaluating that vehicle’s safety compliance. The simulation, modeling and analysis tools(such as domain specific RPOC models, and visualization and virtual reality) allow for detailed design and development and/or help provide the independent assessment

  2. The role of smart systems in rendezvous, close proximity operations and docking maneuvers

    Science.gov (United States)

    Szatkowski, Gerard P.

    1991-01-01

    Various missions scenarios (Space Station logistics, LEO and GEO services, and SEI operation) will involve flexibility in mission management. This means operations will be one or a combination of the following: autonomous, supervised autonomous, and machine aided manual control. Smart Systems will likely play a significant role in making these missions successful from a safety/reliability perspective and less costly from an operations perspective. This does not imply that Smart Systems need to be super sophisticated. On the contrary, Smart Systems have been described as automated intelligence that if a person had done it wrong, it would be considered stupid. The first part of this paper will describe the types of Smart System techniques involved in AR and CC, their specifications, duties, and interactions. Next will be a discussion of the work performed under the auspice of the ALS Program to further Expert Systems applications imbedded in the control process, NASA/JSC CRAD, and other related IRAD projects. This will include issues pertaining to the following: integration, speed, knowledge encapsulation, and cooperative systems. Finally, a brief description will be offered to outline the major obstacles for the acceptance of Smart Systems in critical applications.

  3. A Summary of the Rendezvous, Proximity Operations, Docking, and Undocking (RPODU) Lessons Learned from the Defense Advanced Research Project Agency (DARPA) Orbital Express (OE) Demonstration System Mission

    Science.gov (United States)

    Dennehy, Cornelius J.; Carpenter, James R.

    2011-01-01

    The Guidance, Navigation, and Control (GN&C) Technical Discipline Team (TDT) sponsored Dr. J. Russell Carpenter, a Navigation and Rendezvous Subject Matter Expert (SME) from NASA's Goddard Space Flight Center (GSFC), to provide support to the Defense Advanced Research Project Agency (DARPA) Orbital Express (OE) rendezvous and docking flight test that was conducted in 2007. When that DARPA OE mission was completed, Mr. Neil Dennehy, NASA Technical Fellow for GN&C, requested Dr. Carpenter document his findings (lessons learned) and recommendations for future rendezvous missions resulting from his OE support experience. This report captures lessons specifically from anomalies that occurred during one of OE's unmated operations.

  4. Adaptive relative pose control for autonomous spacecraft rendezvous and proximity operations with thrust misalignment and model uncertainties

    Science.gov (United States)

    Sun, Liang; Zheng, Zewei

    2017-04-01

    An adaptive relative pose control strategy is proposed for a pursue spacecraft in proximity operations on a tumbling target. Relative position vector between two spacecraft is required to direct towards the docking port of the target while the attitude of them must be synchronized. With considering the thrust misalignment of pursuer, an integrated controller for relative translational and relative rotational dynamics is developed by using norm-wise adaptive estimations. Parametric uncertainties, unknown coupled dynamics, and bounded external disturbances are compensated online by adaptive update laws. It is proved via Lyapunov stability theory that the tracking errors of relative pose converge to zero asymptotically. Numerical simulations including six degrees-of-freedom rigid body dynamics are performed to demonstrate the effectiveness of the proposed controller.

  5. Autonomous rendezvous and proximate motion of satellites - A covariance analysis

    Science.gov (United States)

    Mackison, Donald L.; Morenthaler, George W.

    1992-08-01

    The construction of large (10 exp 6 kg) spacecraft in orbit will, in order to meet the requirements of interplanetary launch windows and restrictions of launch facilities require the launch of several 100,000-kg payloads using the Heavy Lift Launch Vehicle (HLLV), and their subsequent in-orbit assembly into a completed spacecraft. This assembly will require that the components rendezvous and dock within a reasonable time, taking into consideration launch window restrictions and the operating time limits on the component spacecraft. This will require that the rendezvous and docking operations be accomplished autonomously, without ground control. The trajectory and attitude control of a chase satellite to rendezvous with a target satellite are modeled using the Euler-Hill equations of relative orbital motion, and a linearized set of relative attitude parameters. The effect of uncertainties in the orbit dynamics and sensors, and the attitude dynamics and sensors are modeled using a linearized covariance analysis.

  6. Proximal tibiofibular joint: Rendezvous with a forgotten articulation

    Directory of Open Access Journals (Sweden)

    Amitav Sarma

    2015-01-01

    Full Text Available The proximal tibiofibular joint (PTFJ is a plane type synovial joint. The primary function of the PTFJ is dissipation of torsional stresses applied at the ankle and the lateral tibial bending moments besides a very significant tensile, rather than compressive weight bearing. Though rare, early diagnosis and treatment of the PTFJ dislocation are essential to prevent chronic joint instability and extensive surgical intervention to restore normal PTFJ biomechanics, ankle and knee function, especially in athletes prone to such injuries. PTFJ dislocations often remain undiagnosed in polytrauma scenario with ipsilateral tibial fracture due to the absence of specific signs and symptoms of PTFJ injury. Standard orthopedic textbooks generally describe no specific tests or radiological signs for assessment of the integrity of this joint. The aim of this paper was to review the relevant clinical anatomy, biomechanics and traumatic pathology of PTFJ with its effect on the knee emphasizing the importance of early diagnosis through a high index of suspicion. Dislocation of the joint may have serious implications for the knee joint stability since fibular collateral ligament and posterolateral ligament complex is attached to the upper end of the fibula. Any high energy knee injury with peroneal nerve palsy should immediately raise the suspicion of PTFJ dislocation especially if the mechanism of injury involved knee twisting in flexion beyond 80° and in such cases a comparative radiograph of the contralateral side should be performed. Wider clinical awareness can avoid both embarrassingly extensive surgeries due to diagnostic delays or unnecessary overtreatment due to misinformation on the part of the treating surgeon.

  7. History of Space Shuttle Rendezvous

    Science.gov (United States)

    Goodman, John L.

    2011-01-01

    This technical history is intended to provide a technical audience with an introduction to the rendezvous and proximity operations history of the Space Shuttle Program. It details the programmatic constraints and technical challenges encountered during shuttle development in the 1970s and over thirty years of shuttle missions. An overview of rendezvous and proximity operations on many shuttle missions is provided, as well as how some shuttle rendezvous and proximity operations systems and flight techniques evolved to meet new programmatic objectives. This revised edition provides additional information on Mercury, Gemini, Apollo, Skylab, and Apollo/Soyuz. Some chapters on the Space Shuttle have been updated and expanded. Four special focus chapters have been added to provide more detailed information on shuttle rendezvous. A chapter on the STS-39 mission of April/May 1991 describes the most complex deploy/retrieve mission flown by the shuttle. Another chapter focuses on the Hubble Space Telescope servicing missions. A third chapter gives the reader a detailed look at the February 2010 STS-130 mission to the International Space Station. The fourth chapter answers the question why rendezvous was not completely automated on the Gemini, Apollo, and Space Shuttle vehicles.

  8. Cross Cutting Relative Navigation Technologies for Improved Landing Accuracy and Vehicle-to-Vehicle Rendezvous and Docking

    Science.gov (United States)

    Miller, K. L.; Masciarelli, J.; Rohrschneider, R. R.

    2012-06-01

    This presentation addresses recent development and test progress, as well as future technology advancement plans for precision landing and Autonomous Rendezvous, Proximity Operations and Docking (ARPOD).

  9. Sensory fusion for planetary surface robotic navigation, rendezvous, and manipulation operations

    Science.gov (United States)

    Huntsberger, T.; Cheng, Y.; Baumgartner, E. T.; Robinson, M.; Schenker, P. S.

    2003-01-01

    This paper reports some of the ongoing work at JPL in the areas of autonomous sensory fusion of both raw and derived inputs for better localization during long traverses, precision rendezvous operations with both labeled and unlabeled targets, and precision manipulation of targets.

  10. Orion Handling Qualities During ISS Proximity Operations and Docking

    Science.gov (United States)

    Stephens, John-Paul; Vos, Gordon A.; Bilimoria, Karl D.; Mueller, Eric R.; Brazzel, Jack; Spehar, Pete

    2011-01-01

    NASA's Orion spacecraft is designed to autonomously rendezvous and dock with many vehicles including the International Space Station. However, the crew is able to assume manual control of the vehicle s attitude and flight path. In these instances, Orion must meet handling qualities requirements established by NASA. Two handling qualities assessments were conducted at the Johnson Space Center to evaluate preliminary designs of the vehicle using a six degree of freedom, high-fidelity guidance, navigation, and control simulation. The first assessed Orion s handling qualities during the last 20 ft before docking, and included both steady and oscillatory motions of the docking target. The second focused on manual acquisition of the docking axis during the proximity operations phase and subsequent station-keeping. Cooper-Harper handling qualities ratings, workload ratings and comments were provided by 10 evaluation pilots for the docking study and 5 evaluation pilots for the proximity operations study. For the docking task, both cases received 90% Level 1 (satisfactory) handling qualities ratings, exceeding NASA s requirement. All ratings for the ProxOps task were Level 1. These evaluations indicate that Orion is on course to meet NASA's handling quality requirements for ProxOps and docking.

  11. Shared control on lunar spacecraft teleoperation rendezvous operations with large time delay

    Science.gov (United States)

    Ya-kun, Zhang; Hai-yang, Li; Rui-xue, Huang; Jiang-hui, Liu

    2017-08-01

    Teleoperation could be used in space on-orbit serving missions, such as object deorbits, spacecraft approaches, and automatic rendezvous and docking back-up systems. Teleoperation rendezvous and docking in lunar orbit may encounter bottlenecks for the inherent time delay in the communication link and the limited measurement accuracy of sensors. Moreover, human intervention is unsuitable in view of the partial communication coverage problem. To solve these problems, a shared control strategy for teleoperation rendezvous and docking is detailed. The control authority in lunar orbital maneuvers that involves two spacecraft as rendezvous and docking in the final phase was discussed in this paper. The predictive display model based on the relative dynamic equations is established to overcome the influence of the large time delay in communication link. We discuss and attempt to prove via consistent, ground-based simulations the relative merits of fully autonomous control mode (i.e., onboard computer-based), fully manual control (i.e., human-driven at the ground station) and shared control mode. The simulation experiments were conducted on the nine-degrees-of-freedom teleoperation rendezvous and docking simulation platform. Simulation results indicated that the shared control methods can overcome the influence of time delay effects. In addition, the docking success probability of shared control method was enhanced compared with automatic and manual modes.

  12. Trajectory design and navigation analysis for Cargo Transfer Vehicle proximity operations

    Science.gov (United States)

    Marsh, S. M.; White, B. D.

    1992-01-01

    The paper documents an investigation of alternative (or off-nominal) final approach trajectories and terminal guidance algorithms for Cargo Transfer Vehicle (CTV) automated rendezvous and proximity operation in the vicinity of Space Station Freedom (SSF). Ten candidate trajectory designs, representing a survey of all approaches that reasonably satisfy the mission constraints, are compared qualitatively and quantitatively. It is shown that several fundamentally different types of approach strategies are feasible in the CTV application and enjoy more favorable passive collision avoidance and plume impingement properties than the nominal. They are, however, generally more costly in propellant. The extent to which an alternative approach is more costly is determined largely by the abort (or specifically the 'hold' or 'wave-off') requirements. These approach techniques are verified in a software simulation using a parametrically defined candidate navigation system, and proximity sensor accuracy requirements are derived.

  13. Trajectory design and navigation analysis for Cargo Transfer Vehicle proximity operations

    Science.gov (United States)

    Marsh, S. M.; White, B. D.

    1992-08-01

    The paper documents an investigation of alternative (or off-nominal) final approach trajectories and terminal guidance algorithms for Cargo Transfer Vehicle (CTV) automated rendezvous and proximity operation in the vicinity of Space Station Freedom (SSF). Ten candidate trajectory designs, representing a survey of all approaches that reasonably satisfy the mission constraints, are compared qualitatively and quantitatively. It is shown that several fundamentally different types of approach strategies are feasible in the CTV application and enjoy more favorable passive collision avoidance and plume impingement properties than the nominal. They are, however, generally more costly in propellant. The extent to which an alternative approach is more costly is determined largely by the abort (or specifically the 'hold' or 'wave-off') requirements. These approach techniques are verified in a software simulation using a parametrically defined candidate navigation system, and proximity sensor accuracy requirements are derived.

  14. Imaging Flash Lidar for Autonomous Safe Landing and Spacecraft Proximity Operation

    Science.gov (United States)

    Amzajerdian, Farzin; Roback, Vincent E.; Brewster, Paul F.; Hines, Glenn D.; Bulyshev, Alexander E.

    2016-01-01

    3-D Imaging flash lidar is recognized as a primary candidate sensor for safe precision landing on solar system bodies (Moon, Mars, Jupiter and Saturn moons, etc.), and autonomous rendezvous proximity operations and docking/capture necessary for asteroid sample return and redirect missions, spacecraft docking, satellite servicing, and space debris removal. During the final stages of landing, from about 1 km to 500 m above the ground, the flash lidar can generate 3-Dimensional images of the terrain to identify hazardous features such as craters, rocks, and steep slopes. The onboard fli1ght computer can then use the 3-D map of terrain to guide the vehicle to a safe location. As an automated rendezvous and docking sensor, the flash lidar can provide relative range, velocity, and bearing from an approaching spacecraft to another spacecraft or a space station from several kilometers distance. NASA Langley Research Center has developed and demonstrated a flash lidar sensor system capable of generating 16k pixels range images with 7 cm precision, at a 20 Hz frame rate, from a maximum slant range of 1800 m from the target area. This paper describes the lidar instrument design and capabilities as demonstrated by the closed-loop flight tests onboard a rocket-propelled free-flyer vehicle (Morpheus). Then a plan for continued advancement of the flash lidar technology will be explained. This proposed plan is aimed at the development of a common sensor that with a modest design adjustment can meet the needs of both landing and proximity operation and docking applications.

  15. Spacecraft rendezvous and docking

    DEFF Research Database (Denmark)

    Jørgensen, John Leif

    1999-01-01

    The phenomenons and problems encountered when a rendezvous manoeuvre, and possible docking, of two spacecrafts has to be performed, have been the topic for numerous studies, and, details of a variety of scenarios has been analysed. So far, all solutions that has been brought into realization has...... been based entirely on direct human supervision and control. This paper describes a vision-based system and methodology, that autonomously generates accurate guidance information that may assist a human operator in performing the tasks associated with both the rendezvous and docking navigation...... relative pose information to assist the human operator during the docking phase. The closed loop and operator assistance performance of the system have been assessed using a test bench including human operator, navigation module and high fidelity visualization module. The tests performed verified...

  16. Concepts of Operations for Asteroid Rendezvous Missions Focused on Resources Utilization

    Science.gov (United States)

    Mueller, Robert P.; Sibille, Laurent; Sanders, Gerald B.; Jones, Christopher A.

    2014-01-01

    Several asteroids are the targets of international robotic space missions currently manifested or in the planning stage. This global interest reflects a need to study these celestial bodies for the scientific information they provide about our solar system, and to better understand how to mitigate the collision threats some of them pose to Earth. Another important objective of these missions is providing assessments of the potential resources that asteroids could provide to future space architectures. In this paper, we examine a series of possible mission operations focused on advancing both our knowledge of the types of asteroids suited for different forms of resource extraction, and the capabilities required to extract those resources for mission enhancing and enabling uses such as radiation protection, propulsion, life support, shelter and manufacturing. An evolutionary development and demonstration approach is recommended within the framework of a larger campaign that prepares for the first landings of humans on Mars. As is the case for terrestrial mining, the development and demonstration approach progresses from resource prospecting (understanding the resource, and mapping the 'ore body'), mining/extraction feasibility and product assessment, pilot operations, to full in-situ resource utilization (ISRU). Opportunities to gather specific knowledge for ISRU via resource prospecting during science missions to asteroids are also examined to maximize the pace of development of needed ISRU capabilities and technologies for deep space missions.

  17. Spacecraft rendezvous and docking

    DEFF Research Database (Denmark)

    Jørgensen, John Leif

    1999-01-01

    procedures. The method described generates, based on a single camera and a priory information about the target vehicle and orbit data, all necessary guidance information for closed-loop autonomous navigation, from first detection at far distance, to a close up a hold point. Furthermore, the system provide...... been based entirely on direct human supervision and control. This paper describes a vision-based system and methodology, that autonomously generates accurate guidance information that may assist a human operator in performing the tasks associated with both the rendezvous and docking navigation...

  18. Fuzzy logic application for modeling man-in-the-loop space shuttle proximity operations. M.S. Thesis - MIT

    Science.gov (United States)

    Brown, Robert B.

    1994-01-01

    A software pilot model for Space Shuttle proximity operations is developed, utilizing fuzzy logic. The model is designed to emulate a human pilot during the terminal phase of a Space Shuttle approach to the Space Station. The model uses the same sensory information available to a human pilot and is based upon existing piloting rules and techniques determined from analysis of human pilot performance. Such a model is needed to generate numerous rendezvous simulations to various Space Station assembly stages for analysis of current NASA procedures and plume impingement loads on the Space Station. The advantages of a fuzzy logic pilot model are demonstrated by comparing its performance with NASA's man-in-the-loop simulations and with a similar model based upon traditional Boolean logic. The fuzzy model is shown to respond well from a number of initial conditions, with results typical of an average human. In addition, the ability to model different individual piloting techniques and new piloting rules is demonstrated.

  19. In-Flight Operation of the Dawn Ion Propulsion System: Status at One Year from the Vesta Rendezvous

    Science.gov (United States)

    Garner, Charles E.; Rayman, Marc D.

    2010-01-01

    , 2007 and was successfully concluded as planned on October 31, 2008. During this time period the Dawn IPS was operated mostly at full power for approximately 6500 hours, consumed 71.7 kg of xenon and delivered approximately 1.8 km/s of delta V to the spacecraft. The thrusting to Mars was followed by a coasting period of approximately 3.5 months that included a Mars flyby in February of 2009. The Mars flyby provided a gravity assist (MGA) for a plane change and approximately 1 km/s of heliocentric energy increase and is the only part of the mission following launch in which a needed velocity change is not accomplished by the IPS. During the coast period IPS was operated for a trajectory correction maneuver and for engineering tests but was not operated for primary propulsion. Closest approach to Mars occurred as planned on February 17, 2009 and was followed by another coasting period of just under 4 months in duration. During this last coasting phase IPS was operated only for routine maintenance activities and for system engineering tests. Deterministic thrusting for heliocentric transfer to Vesta resumed on June 8, 2009. Since resumption of cruise to Vesta IPS has been operated at throttled power levels, most of the time at full power, and with a duty cycle of approximately 93%, leading to an arrival at Vesta in July of 2011 and arrival at Ceres in February 2015. This paper provides an overview of Dawn's mission objectives and the results of Dawn IPS mission operations through one year from the spacecraft's rendezvous with Vesta.

  20. Reactive Rendezvous and Docking Sequencer Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Mars Sample Return poses some of the most challenging operational activities of any NASA deep space mission. Rendezvous of a vehicle with a sample canister in order...

  1. Survey of orbital dynamics and control of space rendezvous

    Institute of Scientific and Technical Information of China (English)

    Luo Yazhong; Zhang Jin; Tang Guojin

    2014-01-01

    Rendezvous orbital dynamics and control (RODC) is a key technology for operating space rendezvous and docking missions. This paper surveys the studies on RODC. Firstly, the basic relative dynamics equation set is introduced and its improved versions are evaluated. Secondly, studies on rendezvous trajectory optimization are commented from three aspects:the linear rendez-vous, the nonlinear two-body rendezvous, and the perturbed and constrained rendezvous. Thirdly, studies on relative navigation are briefly reviewed, and then close-range control methods including automated control, manual control, and telecontrol are analyzed. Fourthly, advances in rendezvous trajectory safety and robust analysis are surveyed, and their applications in trajectory optimization are discussed. Finally, conclusions are drawn and prospects of studies on RODC are presented.

  2. Détection et suivi visuels robustes d'objets complexes : applications au rendezvous spatial autonome

    OpenAIRE

    Petit, Antoine

    2013-01-01

    In this thesis, we address the issue of fully localizing a known object through computer vision, using a monocular camera, what is a central problem in robotics. A particular attention is here paid on space robotics applications, with the aims of providing a unified visual localization system for autonomous navigation purposes for space rendezvous and proximity operations. Two main challenges of the problem are tackled: initially detecting the targeted object and then tracking it frame-by-fra...

  3. A new approximate proximal point algorithm for maximal monotone operator

    Institute of Scientific and Technical Information of China (English)

    HE; Bingsheng(何炳生); LIAO; Lizhi(廖立志); YANG; Zhenhua(杨振华)

    2003-01-01

    The problem concerned in this paper is the set-valued equation 0 ∈ T(z) where T is a maximal monotone operator. For given xk and βk > 0, some existing approximate proximal point algorithms take xk+1 = xk such that xk +ek∈ xk + βkT(xk) and||ek|| ≤ηk||xk - xk||, where {ηk} is a non-negative summable sequence. Instead of xk+1 = xk, the new iterate of the proposing method is given by xk+1 = PΩ[xk - ek], where Ω is the domain of T and PΩ(@) denotes the projection on Ω. The convergence is proved under a significantly relaxed restriction supk>0 ηk < 1.

  4. Hubble Servicing Challenges Drive Innovation of Shuttle Rendezvous Techniques

    Science.gov (United States)

    Goodman, John L.; Walker, Stephen R.

    2009-01-01

    Hubble Space Telescope (HST) servicing, performed by Space Shuttle crews, has contributed to what is arguably one of the most successful astronomy missions ever flown. Both nominal and contingency proximity operations techniques were developed to enable successful servicing, while lowering the risk of damage to HST systems, and improve crew safety. Influencing the development of these techniques were the challenges presented by plume impingement and HST performance anomalies. The design of both the HST and the Space Shuttle was completed before the potential of HST contamination and structural damage by shuttle RCS jet plume impingement was fully understood. Relative navigation during proximity operations has been challenging, as HST was not equipped with relative navigation aids. Since HST reached orbit in 1990, proximity operations design for servicing missions has evolved as insight into plume contamination and dynamic pressure has improved and new relative navigation tools have become available. Servicing missions have provided NASA with opportunities to gain insight into servicing mission design and development of nominal and contingency procedures. The HST servicing experiences and lessons learned are applicable to other programs that perform on-orbit servicing and rendezvous, both human and robotic.

  5. A Multi-Neighborhood Multi-Operator Algorithm for the Uncapacitated Exam Proximity Problem

    Directory of Open Access Journals (Sweden)

    Tony Wong

    2015-08-01

    Full Text Available An algorithm featuring multiple local search operators and multiple neighborhood structures is applied to the uncapacitated exam proximity problem. The use of multiplicity is to enable effective interplay between intensification and diversification during the search process. The algorithmic design is inspired by Hansen and Mladenovic's Variable Neighborhood Descent algorithm and the "one operator, one landscape" point of view. Its performance was evaluated using publicly available datasets. For the uncapacitated exam proximity problem, the multi-neighborhood and multi-operator algorithm compared favorably against other search techniques. These results should encourage further research on the application of multiple operator approach as solution techniques to the uncapacitated exam proximity problem.

  6. Computer vision for dual spacecraft proximity operations -- A feasibility study

    Science.gov (United States)

    Stich, Melanie Katherine

    A computer vision-based navigation feasibility study consisting of two navigation algorithms is presented to determine whether computer vision can be used to safely navigate a small semi-autonomous inspection satellite in proximity to the International Space Station. Using stereoscopic image-sensors and computer vision, the relative attitude determination and the relative distance determination algorithms estimate the inspection satellite's relative position in relation to its host spacecraft. An algorithm needed to calibrate the stereo camera system is presented, and this calibration method is discussed. These relative navigation algorithms are tested in NASA Johnson Space Center's simulation software, Engineering Dynamic On-board Ubiquitous Graphics (DOUG) Graphics for Exploration (EDGE), using a rendered model of the International Space Station to serve as the host spacecraft. Both vision-based algorithms proved to attain successful results, and the recommended future work is discussed.

  7. Autonomous Rendezvous and Docking Conference, volume 1

    Science.gov (United States)

    1990-01-01

    This document consists of the presentation submitted at the Autonomous Rendezvous and Docking (ARD) Conference. It contains three volumes: ARD hardware technology; ARD software technology; and ARD operations. The purpose of this conference is to identify the technologies required for an on orbit demonstration of the ARD, assess the maturity of these technologies, and provide the necessary insight for a quality assessment of the programmatic management, technical, schedule, and cost risks.

  8. Autonomous Rendezvous and Docking Conference, volume 3

    Science.gov (United States)

    1990-01-01

    This document consists of the presentation submitted at the Autonomous Rendezvous and Docking (ARD) Conference. The document contains three volumes: ARD hardware technology; ARD software technology; and ARD operations. The purpose of this conference is to identify the technologies required for an on orbit demonstration of ARD, assess the maturity of these technologies, and provide the necessary insight for a quality assessment of programmatic management, technical, schedule, and cost risks.

  9. [Experiences and results of 1300 indentation operations for proximal medialization of the patella].

    Science.gov (United States)

    Villiger, K J

    1980-07-01

    Of 1039 patients, 1300 knee joints were operated on for chondropathia patellae or patellofemoral osteoarthrosis; the results are arranged in tabular form. The basic operation was proximal medialization of the patella by indent operation. Additional interventions like retropatellar should be indicated by an experienced surgeon. The excellent results found 6, 12, 40, and 60 months after the operation recommmend this procedure for the treatment of chondropathia patellae or osteoarthrosis.

  10. Flocking and rendezvous in distributed robotics

    CERN Document Server

    Francis, Bruce A

    2016-01-01

    This brief describes the coordinated control of groups of robots using only sensory input – and no direct external commands. Furthermore, each robot employs the same local strategy, i.e., there are no leaders, and the text also deals with decentralized control, allowing for cases in which no single robot can sense all the others. One can get intuition for the problem from the natural world, for example, flocking birds. How do they achieve and maintain their flying formation? Recognizing their importance as the most basic coordination tasks for mobile robot networks, the brief details flocking and rendezvous. They are shown to be physical illustrations of emergent behaviors with global consensus arising from local interactions. The authors extend the consideration of these fundamental ideas to describe their operation in flying robots and prompt readers to pursue further research in the field.  Flocking and Rendezvous in Distributed Robotics will provide graduate students a firm grounding in the subject, w...

  11. Hardware-in-the-Loop Rendezvous Tests of a Novel Actuators Command Concept

    Science.gov (United States)

    Gomes dos Santos, Willer; Marconi Rocco, Evandro; Boge, Toralf; Benninghoff, Heike; Rems, Florian

    2016-09-01

    Integration, test and validation results, in a real-time environment, of a novel concept for spacecraft control are presented in this paper. The proposed method commands simultaneously a group of actuators optimizing a given set of objective functions based on a multiobjective optimization technique. Since close proximity maneuvers play an important role in orbital servicing missions, the entire GNC system has been integrated and tested at a hardware-in-the-loop (HIL) rendezvous and docking simulator known as European Proximity Operations Simulator (EPOS). During the test campaign at EPOS facility, a visual camera has been used to provide the necessary measurements for calculating the relative position with respect to the target satellite during closed-loop simulations. In addition, two different configurations of spacecraft control have been considered in this paper: a thruster reaction control system and a mixed actuators mode which includes thrusters, reaction wheels, and magnetic torqrods. At EPOS, results of HIL closed-loop tests have demonstrated that a safe and stable rendezvous approach can be achieved with the proposed GNC loop.

  12. Hardware-in-the-Loop Rendezvous Tests of a Novel Actuators Command Concept

    Science.gov (United States)

    Gomes dos Santos, Willer; Marconi Rocco, Evandro; Boge, Toralf; Benninghoff, Heike; Rems, Florian

    2016-12-01

    Integration, test and validation results, in a real-time environment, of a novel concept for spacecraft control are presented in this paper. The proposed method commands simultaneously a group of actuators optimizing a given set of objective functions based on a multiobjective optimization technique. Since close proximity maneuvers play an important role in orbital servicing missions, the entire GNC system has been integrated and tested at a hardware-in-the-loop (HIL) rendezvous and docking simulator known as European Proximity Operations Simulator (EPOS). During the test campaign at EPOS facility, a visual camera has been used to provide the necessary measurements for calculating the relative position with respect to the target satellite during closed-loop simulations. In addition, two different configurations of spacecraft control have been considered in this paper: a thruster reaction control system and a mixed actuators mode which includes thrusters, reaction wheels, and magnetic torqrods. At EPOS, results of HIL closed-loop tests have demonstrated that a safe and stable rendezvous approach can be achieved with the proposed GNC loop.

  13. The factors influencing the decision making of operative treatment for proximal humeral fractures

    NARCIS (Netherlands)

    Hageman, M.G.; Jayakumar, P.; King, J.D.; Guitton, T.G.; Doornberg, J.N.; Ring, D.; Poelhekke, L.M.S.J.

    2015-01-01

    BACKGROUND: The factors influencing the decision making of operative treatment for fractures of the proximal humerus are debated. We hypothesized that there is no difference in treatment recommendations between surgeons shown radiographs alone and those shown radiographs and patient information. Sec

  14. Optimised collision avoidance for an ultra-close rendezvous with a failed satellite based on the Gauss pseudospectral method

    Science.gov (United States)

    Chu, Xiaoyu; Zhang, Jingrui; Lu, Shan; Zhang, Yao; Sun, Yue

    2016-11-01

    This paper presents a trajectory planning algorithm to optimise the collision avoidance of a chasing spacecraft operating in an ultra-close proximity to a failed satellite. The complex configuration and the tumbling motion of the failed satellite are considered. The two-spacecraft rendezvous dynamics are formulated based on the target body frame, and the collision avoidance constraints are detailed, particularly concerning the uncertainties. An optimisation solution of the approaching problem is generated using the Gauss pseudospectral method. A closed-loop control is used to track the optimised trajectory. Numerical results are provided to demonstrate the effectiveness of the proposed algorithms.

  15. Spacecraft Proximity Operations Used to Estimate the Dynamical & Physical Properties of a Resident Space Object

    Science.gov (United States)

    2007-03-01

    Document, 2006. 26. D. Mehrholz, W. Flury R. Jehn H. Klinkrad M. Landgraf, L. Leushacke. “De- tecting, Tracking and Imaging Space Debris ”. Eurpean Space ...SPACECRAFT PROXIMITY OPERATIONS USED TO ESTIMATE THE DYNAMICAL & PHYSICAL PROPERTIES OF A RESIDENT SPACE OBJECT THESIS Abraham Franz Brunner, First...OPERATIONS USED TO ESTIMATE THE DYNAMICAL & PHYSICAL PROPERTIES OF A RESIDENT SPACE OBJECT THESIS Presented to the Faculty Department of Aeronautics and

  16. Source tracking swine fecal waste in surface water proximal to swine concentrated animal feeding operations.

    Science.gov (United States)

    Heaney, Christopher D; Myers, Kevin; Wing, Steve; Hall, Devon; Baron, Dothula; Stewart, Jill R

    2015-04-01

    Swine farming has gone through many changes in the last few decades, resulting in operations with a high animal density known as confined animal feeding operations (CAFOs). These operations produce a large quantity of fecal waste whose environmental impacts are not well understood. The purpose of this study was to investigate microbial water quality in surface waters proximal to swine CAFOs including microbial source tracking of fecal microbes specific to swine. For one year, surface water samples at up- and downstream sites proximal to swine CAFO lagoon waste land application sites were tested for fecal indicator bacteria (fecal coliforms, Escherichia coli and Enterococcus) and candidate swine-specific microbial source-tracking (MST) markers (Bacteroidales Pig-1-Bac, Pig-2-Bac, and Pig-Bac-2, and methanogen P23-2). Testing of 187 samples showed high fecal indicator bacteria concentrations at both up- and downstream sites. Overall, 40%, 23%, and 61% of samples exceeded state and federal recreational water quality guidelines for fecal coliforms, E. coli, and Enterococcus, respectively. Pig-1-Bac and Pig-2-Bac showed the highest specificity to swine fecal wastes and were 2.47 (95% confidence interval [CI]=1.03, 5.94) and 2.30 times (95% CI=0.90, 5.88) as prevalent proximal down- than proximal upstream of swine CAFOs, respectively. Pig-1-Bac and Pig-2-Bac were also 2.87 (95% CI=1.21, 6.80) and 3.36 (95% CI=1.34, 8.41) times as prevalent when 48 hour antecedent rainfall was greater than versus less than the mean, respectively. Results suggest diffuse and overall poor sanitary quality of surface waters where swine CAFO density is high. Pig-1-Bac and Pig-2-Bac are useful for tracking off-site conveyance of swine fecal wastes into surface waters proximal to and downstream of swine CAFOs and during rain events. Copyright © 2014 Elsevier B.V. All rights reserved.

  17. Source tracking swine fecal waste in surface water proximal to swine concentrated animal feeding operations

    Science.gov (United States)

    Heaney, Christopher D.; Myers, Kevin; Wing, Steve; Hall, Devon; Baron, Dothula; Stewart, Jill R.

    2015-01-01

    Swine farming has gone through many changes in the last few decades, resulting in operations with a high animal density known as confined animal feeding operations (CAFOs). These operations produce a large quantity of fecal waste whose environmental impacts are not well understood. The purpose of this study was to investigate microbial water quality in surface waters proximal to swine CAFOs including microbial source tracking of fecal microbes specific to swine. For one year, surface water samples at up- and downstream sites proximal to swine CAFO lagoon waste land application sites were tested for fecal indicator bacteria (fecal coliforms, Escherichia coli and Enterococcus) and candidate swine-specific microbial source-tracking (MST) markers (Bacteroidales Pig-1-Bac, Pig-2-Bac, and Pig-Bac-2, and methanogen P23-2). Testing of 187 samples showed high fecal indicator bacteria concentrations at both up- and downstream sites. Overall, 40%, 23%, and 61% of samples exceeded state and federal recreational water quality guidelines for fecal coliforms, E. coli, and Enterococcus, respectively. Pig-1-Bac and Pig-2-Bac showed the highest specificity to swine fecal wastes and were 2.47 (95% confidence interval [CI] = 1.03, 5.94) and 2.30 times (95% CI = 0.90, 5.88) as prevalent proximal down- than proximal upstream of swine CAFOs, respectively. Pig-1-Bac and Pig-2-Bac were also 2.87 (95% CI = 1.21, 6.80) and 3.36 (95% CI = 1.34, 8.41) times as prevalent when 48 hour antecedent rainfall was greater than versus less than the mean, respectively. Results suggest diffuse and overall poor sanitary quality of surface waters where swine CAFO density is high. Pig-1-Bac and Pig-2-Bac are useful for tracking off-site conveyance of swine fecal wastes into surface waters proximal to and downstream of swine CAFOs and during rain events. PMID:25600418

  18. Autonomous Rendezvous and Docking Conference, volume 2

    Science.gov (United States)

    1990-01-01

    Autonomous Rendezvous and Docking (ARD) will be a requirement for future space programs. Clear examples include satellite servicing, repair, recovery, and reboost in the near term, and the longer range lunar and planetary exploration programs. ARD will permit more aggressive unmanned space activities, while providing a valuable operational capability for manned missions. The purpose of the conference is to identify the technologies required for an on-orbit demonstration of ARD, assess the maturity of those technologies, and provide the necessary insight for a quality assessment of programmatic management, technical, schedule, and cost risks.

  19. Guidance and Control of Position and Attitude for Rendezvous and Dock/Berthing with a Noncooperative/Target Spacecraft

    Directory of Open Access Journals (Sweden)

    Gilberto Arantes

    2014-01-01

    Full Text Available Noncooperative target spacecrafts are those assets in orbit that cannot convey any information about their states (position, attitude, and velocities or facilitate rendezvous and docking/berthing (RVD/B process. Designing a guidance, navigation, and control (GNC module for the chaser in a RVD/B mission with noncooperative target should be inevitably solved for on-orbit servicing technologies. The proximity operations and the guidance for achieving rendezvous problems are addressed in this paper. The out-of-plane maneuvers of proximity operations are explored with distinct subphases, including a chaser far approach in the target’s orbit to the first hold point and a closer approach to the final berthing location. Accordingly, guidance solutions are chosen for each subphase from the standard Hill based Closhessy-Willtshire (CW solution, elliptical fly-around, and Glideslope algorithms. The control is based on a linear quadratic regulator approach (LQR. At the final berthing location, attitude tracker based on a proportional derivative (PD form is tested to synchronize the chaser and target attitudes. The paper analyzes the performance of both controllers in terms of the tracking ability and the robustness. Finally, it prescribes any restrictions that may be imposed on the guidance during any subphase which can help to improve the controllers tracking ability.

  20. Adaptive variable-structure finite-time mode control for spacecraft proximity operations with actuator saturation

    Science.gov (United States)

    Lee, Daero; Vukovich, George; Gui, Haichao

    2017-05-01

    This paper presents an adaptive variable-structure finite-time control for spacecraft proximity maneuvers under parameter uncertainties, external disturbances and actuator saturation. The coupled six degrees-of-freedom dynamics are modeled for spacecraft relative motion, where the exponential coordinates on the Lie group SE(3) are employed to describe relative configuration. No prior knowledge of inertia matrix and mass of the spacecraft is required for the proposed control law, which implies that the proposed control scheme can be applied in spacecraft systems with large parametric uncertainties in inertia matrix and mass. Finite-time convergence of the feedback system with the proposed control law is established. Numerical simulation results are presented to illustrate the effectiveness of the proposed control law for spacecraft proximity operations with actuator saturation.

  1. Multi-Sensor Testing for Automated Rendezvous and Docking Sensor Testing at the Flight Robotics Lab

    Science.gov (United States)

    Brewster, Linda L.; Howard, Richard T.; Johnston, A. S.; Carrington, Connie; Mitchell, Jennifer D.; Cryan, Scott P.

    2008-01-01

    The Exploration Systems Architecture defines missions that require rendezvous, proximity operations, and docking (RPOD) of two spacecraft both in Low Earth Orbit (LEO) and in Low Lunar Orbit (LLO). Uncrewed spacecraft must perform automated and/or autonomous rendezvous, proximity operations and docking operations (commonly known as AR&D). The crewed missions may also perform rendezvous and docking operations and may require different levels of automation and/or autonomy, and must provide the crew with relative navigation information for manual piloting. The capabilities of the RPOD sensors are critical to the success ofthe Exploration Program. NASA has the responsibility to determine whether the Crew Exploration Vehicle (CEV) contractor-proposed relative navigation sensor suite will meet the requirements. The relatively low technology readiness level of AR&D relative navigation sensors has been carried as one of the CEV Project's top risks. The AR&D Sensor Technology Project seeks to reduce the risk by the testing and analysis of selected relative navigation sensor technologies through hardware-in-the-Ioop testing and simulation. These activities will provide the CEV Project information to assess the relative navigation sensors maturity as well as demonstrate test methods and capabilities. The first year of this project focused on a series of "pathfinder" testing tasks to develop the test plans, test facility requirements, trajectories, math model architecture, simulation platform, and processes that will be used to evaluate the Contractor-proposed sensors. Four candidate sensors were used in the first phase of the testing. The second phase of testing used four sensors simultaneously: two Marshall Space Flight Center (MSFC) Advanced Video Guidance Sensors (AVGS), a laser-based video sensor that uses retroreflectors attached to the target vehicle, and two commercial laser range finders. The multi-sensor testing was conducted at MSFC's Flight Robotics Laboratory (FRL

  2. Multi-Sensor Testing for Automated Rendezvous and Docking Sensor Testing at the Flight Robotics Lab

    Science.gov (United States)

    Brewster, Linda L.; Howard, Richard T.; Johnston, A. S.; Carrington, Connie; Mitchell, Jennifer D.; Cryan, Scott P.

    2008-01-01

    The Exploration Systems Architecture defines missions that require rendezvous, proximity operations, and docking (RPOD) of two spacecraft both in Low Earth Orbit (LEO) and in Low Lunar Orbit (LLO). Uncrewed spacecraft must perform automated and/or autonomous rendezvous, proximity operations and docking operations (commonly known as AR&D). The crewed missions may also perform rendezvous and docking operations and may require different levels of automation and/or autonomy, and must provide the crew with relative navigation information for manual piloting. The capabilities of the RPOD sensors are critical to the success ofthe Exploration Program. NASA has the responsibility to determine whether the Crew Exploration Vehicle (CEV) contractor-proposed relative navigation sensor suite will meet the requirements. The relatively low technology readiness level of AR&D relative navigation sensors has been carried as one of the CEV Project's top risks. The AR&D Sensor Technology Project seeks to reduce the risk by the testing and analysis of selected relative navigation sensor technologies through hardware-in-the-Ioop testing and simulation. These activities will provide the CEV Project information to assess the relative navigation sensors maturity as well as demonstrate test methods and capabilities. The first year of this project focused on a series of "pathfinder" testing tasks to develop the test plans, test facility requirements, trajectories, math model architecture, simulation platform, and processes that will be used to evaluate the Contractor-proposed sensors. Four candidate sensors were used in the first phase of the testing. The second phase of testing used four sensors simultaneously: two Marshall Space Flight Center (MSFC) Advanced Video Guidance Sensors (AVGS), a laser-based video sensor that uses retroreflectors attached to the target vehicle, and two commercial laser range finders. The multi-sensor testing was conducted at MSFC's Flight Robotics Laboratory (FRL

  3. Autonomous rendezvous and docking: A commercial approach to on-orbit technology validation

    Science.gov (United States)

    Tchoryk, Peter, Jr.; Whitten, Raymond P.

    1991-01-01

    SpARC, in conjunction with its corporate affiliates, is planning an on-orbit validation of autonomous rendezvous and docking (ARD) technology. The emphasis in this program is to utilize existing technology and commercially available components wherever possible. The primary subsystems to be validated by this demonstration include GPS receivers for navigation, a video-based sensor for proximity operations, a fluid connector mechanism to demonstrate fluid resupply capability, and a compliant, single-point docking mechanism. The focus for this initial experiment will be ELV based and will make use of two residual Commercial Experiment Transporter (COMET) service modules. The first COMET spacecraft will be launched in late 1992 and will serve as the target vehicle. After the second COMET spacecraft has been launched in late 1994, the ARD demonstration will take place. The service module from the second COMET will serve as the chase vehicle.

  4. Autonomous spacecraft rendezvous and docking

    Science.gov (United States)

    Tietz, J. C.; Almand, B. J.

    A storyboard display is presented which summarizes work done recently in design and simulation of autonomous video rendezvous and docking systems for spacecraft. This display includes: photographs of the simulation hardware, plots of chase vehicle trajectories from simulations, pictures of the docking aid including image processing interpretations, and drawings of the control system strategy. Viewgraph-style sheets on the display bulletin board summarize the simulation objectives, benefits, special considerations, approach, and results.

  5. Validating an artificial intelligence human proximity operations system with test cases

    Science.gov (United States)

    Huber, Justin; Straub, Jeremy

    2013-05-01

    An artificial intelligence-controlled robot (AICR) operating in close proximity to humans poses risk to these humans. Validating the performance of an AICR is an ill posed problem, due to the complexity introduced by the erratic (noncomputer) actors. In order to prove the AICR's usefulness, test cases must be generated to simulate the actions of these actors. This paper discusses AICR's performance validation in the context of a common human activity, moving through a crowded corridor, using test cases created by an AI use case producer. This test is a two-dimensional simplification relevant to autonomous UAV navigation in the national airspace.

  6. The Asteroid Impact and Deflection Assessment (AIDA) mission: Science Proximity Operations

    Science.gov (United States)

    Barnouin, Olivier; Bellerose, Julie; Carnelli, Ian; Carrol, Kieran; Ciarletti, Valérie; Cheng, Andrew F.; Galvez, Andres; Green, Simon F.; Grieger, Bjorn; Hirabayashi, Masatoshi; Herique, Alain; Kueppers, Michael; Minton, David A.; Mellab, Karim; Michel, Patrick; Rivkin, Andrew S.; Rosenblatt, Pascal; Tortora, Paolo; Ulamec, Stephan; Vincent, Jean-Baptiste; Zannoni, Marco

    2016-10-01

    The moon of the near-Earth binary asteroid 65803 Didymos is the target of the Asteroid Impact and Deflection Assessment (AIDA) mission. This mission is a joint effort between NASA and ESA to investigate the effectiveness of a kinetic impactor in deflecting an asteroid. The mission is composed of two components: the NASA-led Double Asteroid Redirect Test (DART) that will impact Didymos' moon (henceforth Didymos B), and the ESA-led Asteroid Impact Mission (AIM) that will survey the Didymos system. Both will undertake proximity operations to characterize the physical and dynamical properties of the Didymos system that are of maximum importance in the joint AIDA mission to understand the factors at play when assessing the mometum transfer that follows DART's impact into Didymos B. Using much of ESA's Rosetta experience, the AIM mission will undertake proximity operations both before and after DART's impact. AIM's chracterization includes measuring the precise orbital configuration, masses, internal properties, surface geology and regolith properties of the primary and secondary, using visible and thermal imaging, radar measurements and radio science data. AIM will also release the small MASCOT-2 lander, as well as a suite of a CubeSats to help achieve these objectives. DART proximity observations include two phases of imaging. The first makes use of a suite of long range images that will add light curve data to what will be collected from Earth. These data will refine the orbit period of Didymos B, and provide constraints for modeling the shape of both Didymos A and B. The second phase begins just under an hour before impact when resolved imaging of the Didymos system provides further shape model constraints for the visble parts of both Didymos A and B, some possible constraints on the mass of Didymos B and key geological information of both objects and the impact site. In this presentation, we will summarize the proximity operations undertaken by both DART and AIM

  7. Rendezvous missions with minimoons from L1

    Science.gov (United States)

    Chyba, M.; Haberkorn, T.; Patterson, G.

    2014-07-01

    We propose to present asteroid capture missions with the so-called minimoons. Minimoons are small asteroids that are temporarily captured objects on orbits in the Earth-Moon system. It has been suggested that, despite their small capture probability, at any time there are one or two meter diameter minimoons, and progressively greater numbers at smaller diameters. The minimoons orbits differ significantly from elliptical orbits which renders a rendezvous mission more challenging, however they offer many advantages for such missions that overcome this fact. First, they are already on geocentric orbits which results in short duration missions with low Delta-v, this translates in cost efficiency and low-risk targets. Second, beside their close proximity to Earth, an advantage is their small size since it provides us with the luxury to retrieve the entire asteroid and not only a sample of material. Accessing the interior structure of a near-Earth satellite in its morphological context is crucial to an in-depth analysis of the structure of the asteroid. Historically, 2006 RH120 is the only minimoon that has been detected but work is ongoing to determine which modifications to current observation facilities is necessary to provide detection algorithm capabilities. In the event that detection is successful, an efficient algorithm to produce a space mission to rendezvous with the detected minimoon is highly desirable to take advantage of this opportunity. This is the main focus of our work. For the design of the mission we propose the following. The spacecraft is first placed in hibernation on a Lissajoux orbit around the liberation point L1 of the Earth-Moon system. We focus on eight-shaped Lissajoux orbits to take advantage of the stability properties of their invariant manifolds for our transfers since the cost to minimize is the spacecraft fuel consumption. Once a minimoon has been detected we must choose a point on its orbit to rendezvous (in position and velocities

  8. Operative versus non-operative treatment in complex proximal humeral fractures: a meta-analysis of randomized controlled trials.

    Science.gov (United States)

    Xie, Lin; Ding, Fan; Zhao, Zhigang; Chen, Yan; Xing, Danmou

    2015-01-01

    Whether operative treatment for complex proximal humeral fractures (CPHFs) has a greater benefit over non-operative treatment remains controversial. There is no consensus on the optimal treatment in elderly patients with CPHFs. This updated meta-analysis of randomized controlled trials (RCTs) aims to investigate whether operative treatment is superior to non-operative treatment in CPHFs. The authors searched RCTs in the electronic databases (Cochrane Central Register of Controlled Trials, PubMed, EMBASE, Medline, Embase, Springer Link, Web of Knowledge, OVID and Google Scholar) from their establishment to July 2015. Researches on operative and non-operative treatment for CPHFs were selected in this meta-analysis. The quality of all studies was assessed and effective data was pooled for this meta-analysis. Outcome measurements were functional status include constant scores (CS scores) and disabilities of the arm, shoulder and hand scores (DASH scores), total complication rates and healthy-related quality of life. The meta-analysis was performed with software revman 5.3. Nine articles with a total 518 patients (average age 70.93) met inclusion criteria. Patients were followed up for at least 1 year in all the studies. No statistical differences were found between operative and non-operative treatment in CS scores at 12 mo (months) [MD 1.06 95 % CI (-3.51, 5.62)] and 24 mo [MD -0.61 95 % CI (-5.87, 4.65)]. There are also no statistical differences between operative and non-operative treatment in DASH scores at 12 mo [MD -4.51 95 % CI (-13.49, 4.47)] and 24 mo [MD -7.43 95 % CI (-16.14, 1.27)]. Statistical differences were found between operative and non-operative treatment in total complication rates [RR 1.55, 95 % CI (1.24, 1.94)]. Statistical differences in EQ-5D at 24 mo [MD 0.15, 95 % CI (0.05, 0.24)] were found between operative and non-operative treatment but no statistical differences were found in ED-5D at 12 mo [MD 0.08, 95 % CI (-0.01, 0.17)], 15D at

  9. Fuzzy logic techniques for rendezvous and docking of two geostationary satellites

    Science.gov (United States)

    Ortega, Guillermo

    1995-01-01

    Large assemblings in space require the ability to manage rendezvous and docking operations. In future these techniques will be required for the gradual build up of big telecommunication platforms in the geostationary orbit. The paper discusses the use of fuzzy logic to model and implement a control system for the docking/berthing of two satellites in geostationary orbit. The system mounted in a chaser vehicle determines the actual state of both satellites and generates torques to execute maneuvers to establish the structural latching. The paper describes the proximity operations to collocate the two satellites in the same orbital window, the fuzzy guidance and navigation of the chaser approaching the target and the final Fuzzy berthing. The fuzzy logic system represents a knowledge based controller that realizes the close loop operations autonomously replacing the conventional control algorithms. The goal is to produce smooth control actions in the proximity of the target and during the docking to avoid disturbance torques in the final assembly orbit. The knowledge of the fuzzy controller consists of a data base of rules and the definitions of the fuzzy sets. The knowledge of an experienced spacecraft controller is captured into a set of rules forming the Rules Data Base.

  10. The association between proximity to animal feeding operations and community health: a systematic review.

    Directory of Open Access Journals (Sweden)

    Annette M O'Connor

    Full Text Available BACKGROUND: A systematic review was conducted for the association between animal feeding operations (AFOs and the health of individuals living near AFOs. METHODOLOGY/PRINCIPAL FINDINGS: The review was restricted to studies reporting respiratory, gastrointestinal and mental health outcomes in individuals living near AFOs in North America, European Union, United Kingdom, and Scandinavia. From June to September 2008 searches were conducted in PUBMED, CAB, Web-of-Science, and Agricola with no restrictions. Hand searching of narrative reviews was also used. Two reviewers independently evaluated the role of chance, confounding, information, selection and analytic bias on the study outcome. Nine relevant studies were identified. The studies were heterogeneous with respect to outcomes and exposures assessed. Few studies reported an association between surrogate clinical outcomes and AFO proximity. A negative association was reported when odor was the measure of exposure to AFOs and self-reported disease, the measure of outcome. There was evidence of an association between self-reported disease and proximity to AFO in individuals annoyed by AFO odor. CONCLUSIONS/SIGNIFICANCE: There was inconsistent evidence of a weak association between self-reported disease in people with allergies or familial history of allergies. No consistent dose response relationship between exposure and disease was observable.

  11. The Modular Clock Algorithm for Blind Rendezvous

    Science.gov (United States)

    2009-03-26

    Malinowski [11] define the multiple agent rendezvous problem as the gathering problem. Analysis in this paper will be done on the two agent rendezvous...February 2007. 11. D. Kowalski and A. Malinowski . How to meet in an anonymous network. Theo- retical Computer Science, 2008. 12. Wei Shi Lim. A

  12. Development of an integrated spacecraft Guidance, Navigation, & Control subsystem for automated proximity operations

    Science.gov (United States)

    Schulte, Peter Z.; Spencer, David A.

    2016-01-01

    This paper describes the development and validation process of a highly automated Guidance, Navigation, & Control subsystem for a small satellite on-orbit inspection application, enabling proximity operations without human-in-the-loop interaction. The paper focuses on the integration and testing of Guidance, Navigation, & Control software and the development of decision logic to address the question of how such a system can be effectively implemented for full automation. This process is unique because a multitude of operational scenarios must be considered and a set of complex interactions between subsystem algorithms must be defined to achieve the automation goal. The Prox-1 mission is currently under development within the Space Systems Design Laboratory at the Georgia Institute of Technology. The mission involves the characterization of new small satellite component technologies, deployment of the LightSail 3U CubeSat, entering into a trailing orbit relative to LightSail using ground-in-the-loop commands, and demonstration of automated proximity operations through formation flight and natural motion circumnavigation maneuvers. Operations such as these may be utilized for many scenarios including on-orbit inspection, refueling, repair, construction, reconnaissance, docking, and debris mitigation activities. Prox-1 uses onboard sensors and imaging instruments to perform Guidance, Navigation, & Control operations during on-orbit inspection of LightSail. Navigation filters perform relative orbit determination based on images of the target spacecraft, and guidance algorithms conduct automated maneuver planning. A slew and tracking controller sends attitude actuation commands to a set of control moment gyroscopes, and other controllers manage desaturation, detumble, thruster firing, and target acquisition/recovery. All Guidance, Navigation, & Control algorithms are developed in a MATLAB/Simulink six degree-of-freedom simulation environment and are integrated using

  13. Asteroid Redirect Mission Proximity Operations for Reference Target Asteroid 2008 EV5

    Science.gov (United States)

    Reeves, David M.; Mazanek, Daniel D.; Cichy, Benjamin D.; Broschart, Steve B.; Deweese, Keith D.

    2016-01-01

    NASA's Asteroid Redirect Mission (ARM) is composed of two segments, the Asteroid Redirect Robotic Mission (ARRM), and the Asteroid Redirect Crewed Mission (ARCM). In March of 2015, NASA selected the Robotic Boulder Capture Option1 as the baseline for the ARRM. This option will capture a multi-ton boulder, (typically 2-4 meters in size) from the surface of a large (greater than approx.100 m diameter) Near-Earth Asteroid (NEA) and return it to cis-lunar space for subsequent human exploration during the ARCM. Further human and robotic missions to the asteroidal material would also be facilitated by its return to cis-lunar space. In addition, prior to departing the asteroid, the Asteroid Redirect Vehicle (ARV) will perform a demonstration of the Enhanced Gravity Tractor (EGT) planetary defense technique2. This paper will discuss the proximity operations which have been broken into three phases: Approach and Characterization, Boulder Capture, and Planetary Defense Demonstration. Each of these phases has been analyzed for the ARRM reference target, 2008 EV5, and a detailed baseline operations concept has been developed.

  14. Clinical and functional outcomes after operative management of Salter-Harris III and IV fractures of the proximal tibial epiphysis.

    Science.gov (United States)

    Hill, Brian W; Rizkala, Amir R; Li, Mengnai

    2014-09-01

    Pediatric proximal tibial epiphysis fractures are uncommon and have subsequently received little attention in terms of treatment and outcomes. We studied the clinical and functional outcomes of 13 patients with Salter-Harris III and IV fractures of the proximal tibial epiphysis after operative fixation. Associated meniscus, ligamentous, or neurovascular injury was present in 100% of this cohort. Provisional external fixation and locked plating spanning the open physis were used in the majority of cases. The mean clinical follow-up was 15.69 months, where all fractures progressed to union. Good functional outcomes with a low complication rate are possible after operative fixation of these infrequent injuries.

  15. Proximal gastric vagotomy: effects of two operative techniques on clinical and gastric secretory results.

    Science.gov (United States)

    Hallenbeck, G A; Gleysteen, J J; Aldrete, J S; Slaughter, R L

    1976-01-01

    PGV performed in 39 patients by separating the lesser omentum from the stomach beginning 6 or 7 cm proximal to the pylorus and skeletonizing the distal 1 to 2 cm of esophagus was followed by 15.4% of proven and 10.2 of suspected recurrent ulcers. Insulin tests were done during the first 3 months postoperatively on 31 of the patients, including the 6 with proven and the 4 with suspected recurrent ulcers. The peak acid output to insulin minus tha basal acid output (PAOI-BAO) was less than 5 mEq/hr in 16 cases (52%) and from 5 to 25 mEq/hr in the remaining 15 cases. In 6 patients with proven recurrent ulcer, PAOI-BAO averaged 21.9 mEq/hr (range, 11.3 to 41.8); in the 4 patients with suspected recurrence, 9.5 (range, 4.4 to 11.8).The operative technique was changed in one respect; the distal 5 to 7.5 cm of the esophagus was skeletonized. In 14 patients, the mean PAOI-BAO +/- S.E. within 3 months of PGV was 1985 +/- 0.7 mEq/hr, and 13 of 14 values were less than 5 mEq/hr. One patient developed recurrent ulcer and required re-operation; this patient's value for PAO-BAO was 1.8 mEq/hr. The results show quantitatively that great differences in the completeness of PGV result from differences in the periesophageal dissection and emphasize its importance if optimal results are to be obtained and, especially, if the efficacy of the operation is to be judged. PMID:1015889

  16. Impact of the Intracoronary Rendezvous technique on coronary angioplasty for chronic total occlusion.

    Science.gov (United States)

    Nihei, Taro; Yamamoto, Yoshito; Kudo, Shun; Hanawa, Kenichiro; Hasebe, Yuhi; Takagi, Yusuke; Minatoya, Yutaka; Sugi, Masafumi; Shimokawa, Hiroaki

    2016-08-30

    The Rendezvous technique, which requires bidirectional wiring, is one of the useful methods for improving the success rate of recanalization for chronic total occlusion (CTO) in the field of peripheral intervention. Recently, advanced new devices for percutaneous coronary intervention have enabled us to perform the Rendezvous technique for peripheral as well as for coronary CTO lesions. We used the Intracoronary Rendezvous technique to perform angioplasty for coronary CTO. "Intracoronary Rendezvous" means that Rendezvous was achieved within the CTO lesion. From March 2009 to November 2015, 189 patients underwent CTO angioplasty at our institute, and we treated 10 patients with the Intracoronary Rendezvous technique. This technique involves crossing the Gaia series guidewire to the contralateral Corsair microcatheter located inside the plaque of CTO lesions. The majority of the CTO sites examined were in the proximal RCA (60 %). Lesion length of the occlusion was relatively long (64.4 ± 12.2 mm). Using the biplane imaging system, we were able to control the Gaia guidewires in a specific direction. Furthermore, if the antegrade and retrograde wires can be advanced into contiguous space inside the CTO lesion, we intentionally entered either wire into the contralateral Corsair microcatheter, followed by successful CTO crossing. CTO recanalization was completed for all patients without controlled antegrade retrograde subintimal tracking (CART) or reverse CART. No major complications occurred during hospitalization. These results indicate that the Rendezvous technique, assisted by new devices and a biplane imaging system, represents one of the primary options to achieve successful coronary CTO recanalization. (249/250 words).

  17. Reliable Self-Stabilizing Communication for Quasi Rendezvous

    CERN Document Server

    Johnen, Colette; Lavault, Christian

    2010-01-01

    The paper presents three self-stabilizing protocols for basic fair and reliable link communication primitives. We assume a link-register communication model under read/write atomicity, where every process can read from but cannot write into its neighbours' registers. The first primitive guarantees that any process writes a new value in its register(s) only after all its neighbours have read the previous value, whatever the initial scheduling of processes' actions. The second primitive implements a "weak rendezvous" communication mechanism by using an alternating bit protocol: whenever a process consecutively writes n values (possibly the same ones) in a register, each neighbour is guaranteed to read each value from the register at least once. On the basis of the previous protocol, the third primitive implements a "quasi rendezvous": in words, this primitive ensures furthermore that there exists exactly one reading between two writing operations All protocols are self-stabilizing and run in asynchronous arbitr...

  18. Angles-only relative navigation and closed-loop guidance for spacecraft proximity operations

    Science.gov (United States)

    Luo, Jianjun; Gong, Baichun; Yuan, Jianping; Zhang, Zhaofei

    2016-11-01

    This research investigates angles-only relative navigation and closed-loop guidance algorithm for spacecraft mid-range orbital proximity operations when the orbital maneuver allows for range observability. Emphasis and contribution are on developing angles-only relative navigation and guidance coupling algorithm in the context of Clohessy-Wiltshire and Tschauner-Hempel dynamics. Observability analysis of the relative state is done and the general mathematical expression of the observable condition is obtained. Coupling relationship between the angles-only relative navigation and the multi-pulse sliding guidance is discussed and its analytic expression is derived. A novel closed-loop guidance scheme is designed based on the coupling relationship and unscented kalman filter. Two-body Monte Carlo simulations are conducted to evaluate the validity and test the performance of the closed-loop system. The sensitivities of the navigation and guidance accuracy to the line-of-sight angles accuracy, initial separation and initial state uncertainties, number of pulses, and dynamics are presented and discussed.

  19. Robust total-variation based geophysical inversion using split Bregman and proximity operators

    Science.gov (United States)

    Mohammadi Gheymasi, H.; Gholami, A.; Siahkoohi, H. R.; Amini, N.

    2016-09-01

    In this paper, we take advantages of split Bregman and proximity operators to formulate geophysical inverse problems in a convex optimization setting. In this type of formulation, we can efficiently consider a general convex data misfit term in order to incorporate more realistic error probability assumptions than the ordinary Gaussian distribution. Furthermore, we can simply impose convex non-quadratic and non-smooth regularization terms as a prior information. Although the proposed formulation can be extended for incorporating any types of convex regularization and data fidelity terms, here we consider misfit term corresponding to the Huber norm and anisotropic total variation regularization as a prior to an unknown model structure. This type of regularization enables us to construct piecewise-constant solutions. Two-dimensional linear and non-linear seismic travel-time tomography are studied to evaluate the efficiency of the proposed formulation for handling a robust measure of the misfit term in recovering blocky solutions. We consider the first arrival travel-times which are contaminated by outliers and also a mixed combination of Gaussian and outliers. Finally, Seinsfeld cross-hole tomography data set is used to investigate the performance of the robust approach on real data sets.

  20. Design and development of a Space Station proximity operations research and development mockup

    Science.gov (United States)

    Haines, Richard F.

    1986-01-01

    Proximity operations (Prox-Ops) on-orbit refers to all activities taking place within one km of the Space Station. Designing a Prox-Ops control station calls for a comprehensive systems approach which takes into account structural constraints, orbital dynamics including approach/departure flight paths, myriad human factors and other topics. This paper describes a reconfigurable full-scale mock-up of a Prox-Ops station constructed at Ames incorporating an array of windows (with dynamic star field, target vehicle(s), and head-up symbology), head-down perspective display of manned and unmanned vehicles, voice- actuated 'electronic checklist', computer-generated voice system, expert system (to help diagnose subsystem malfunctions), and other displays and controls. The facility is used for demonstrations of selected Prox-Ops approach scenarios, human factors research (work-load assessment, determining external vision envelope requirements, head-down and head-up symbology design, voice synthesis and recognition research, etc.) and development of engineering design guidelines for future module interiors.

  1. Influence of the experience of operator and assistant on the survival rate of proximal ART restorations: two-year results

    NARCIS (Netherlands)

    A.M. Kemoli; W.E. van Amerongen; G. Opinya

    2009-01-01

    AIM: The objective of the study was to determine the influence of the experience of the operator and the assistant on the survival rate of proximal ART- restorations after 2 years when placed using two methods of tooth-isolation and three glass ionomer cement-brands. STUDY DESIGN: A clinical interve

  2. 75 FR 44794 - Rendezvous International v.

    Science.gov (United States)

    2010-07-29

    ... From the Federal Register Online via the Government Publishing Office FEDERAL MARITIME COMMISSION Rendezvous International v. Chief Cargo Services, Inc., Kaiser Apparel, Inc., Edco Logistics, Inc., Oriental.... Karen V. Gregory, Secretary. BILLING CODE P ...

  3. Rocket Rendezvous at Preassigned Destinations with Optimum

    Directory of Open Access Journals (Sweden)

    T. N. Srivastava

    1982-10-01

    Full Text Available The problem of rendezvous of an interceptor rocket vehicle through optimal exit path with a destination rocket vehicle at a preassigned location on the destination orbit has been investigated for non-coaxial coplanar elliptic launch and destination orbits in an inverse square gravitational field. The case, when launch and destination orbits are coplanar circular, is also discussed. In the end numerical results for rendezvous have been obtained taking Earth and Mars orbits as launch and destination orbits respectively.

  4. Optimal impulsive ellipse-to-circle coplanar rendezvous

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    The problem of ellipse-to-circle coplanar rendezvous with chaser spacecraft in low eccentricity was investigated in this paper.With reference frame established in the centroid of the target spacecraft,the process of ellipse-to-circle coplanar rendezvous was described by the relative equations based on cy-lindrical reference frame,and then the solutions and distributions of optimal rendezvous models of a kind of close ellipse-to-circle coplanar rendezvous were provided.The simulation results showed that the guidance law based on the optimal rendezvous model in this research has good performance,and that the distributions of optimal rendezvous models of ellipse-to-circle coplanar rendezvous with the chaser spacecraft in low eccentricity are similar,albeit with slight difference,to those of rendezvous between close circular orbits.The work in this paper is a useful extension to Prussing’s optimal ren-dezvous theory between close circular orbits.

  5. Hybrid Proximal-Point Methods for Zeros of Maximal Monotone Operators, Variational Inequalities and Mixed Equilibrium Problems

    Directory of Open Access Journals (Sweden)

    Kriengsak Wattanawitoon

    2011-01-01

    Full Text Available We prove strong and weak convergence theorems of modified hybrid proximal-point algorithms for finding a common element of the zero point of a maximal monotone operator, the set of solutions of equilibrium problems, and the set of solution of the variational inequality operators of an inverse strongly monotone in a Banach space under different conditions. Moreover, applications to complementarity problems are given. Our results modify and improve the recently announced ones by Li and Song (2008 and many authors.

  6. Implications of Articulating Machinery on Operator Line of Sight and Efficacy of Camera Based Proximity Detection Systems

    Directory of Open Access Journals (Sweden)

    Nicholas Schwabe

    2017-07-01

    Full Text Available The underground mining industry, and some above ground operations, rely on the use of heavy equipment that articulates to navigate corners in the tight confines of the tunnels. Poor line of sight (LOS has been identified as a problem for safe operation of this machinery. Proximity detection systems, such as a video system designed to provide a 360 degree view around the machine have been implemented to improve the available LOS for the operator. A four-camera system was modeled in a computer environment to assess LOS on a 3D cad model of a typical, articulated machine. When positioned without any articulation, the system is excellent at removing blind spots for a machine driving straight forward or backward in a straight tunnel. Further analysis reveals that when the machine articulates in a simulated corner section, some camera locations are no longer useful for improving LOS into the corner. In some cases, the operator has a superior view into the corner, when compared to the best available view from the camera. The work points to the need to integrate proximity detection systems at the design, build, and manufacture stage, and to consider proper policy and procedures that would address the gains and limits of the systems prior to implementation.

  7. A preliminary clinical trial using flowable glass-ionomer cement as a liner in proximal-ART restorations: the operator effect

    NARCIS (Netherlands)

    Bonifácio, C.C.; Hesse, D.; Bönecker, M.; van Loveren, C.; van Amerongen, W.E.; Raggio, D.P.

    2013-01-01

    .Objectives: This in vivo study was carried out to assess the influence of the operator experience on the survival rate of proximal-ART restorations using a two-layer technique to insert the glass-ionomer cement (GIC). Study Design: Forty five proximal cavities in primary molars were restored in a s

  8. A preliminary clinical trial using flowable glass-ionomer cement as a liner in proximal-ART restorations: the operator effect

    NARCIS (Netherlands)

    Bonifácio, C.C.; Hesse, D.; Bönecker, M.; van Loveren, C.; van Amerongen, W.E.; Raggio, D.P.

    2013-01-01

    .Objectives: This in vivo study was carried out to assess the influence of the operator experience on the survival rate of proximal-ART restorations using a two-layer technique to insert the glass-ionomer cement (GIC). Study Design: Forty five proximal cavities in primary molars were restored in a s

  9. A preliminary clinical trial using flowable glass-ionomer cement as a liner in proximal-ART restorations: the operator effect

    NARCIS (Netherlands)

    Bonifácio, C.C.; Hesse, D.; Bönecker, M.; van Loveren, C.; van Amerongen, W.E.; Raggio, D.P.

    2013-01-01

    .Objectives: This in vivo study was carried out to assess the influence of the operator experience on the survival rate of proximal-ART restorations using a two-layer technique to insert the glass-ionomer cement (GIC). Study Design: Forty five proximal cavities in primary molars were restored in a

  10. Rendezvous Facilities in a Distributed Computer System

    Institute of Scientific and Technical Information of China (English)

    廖先Zhi; 金兰

    1995-01-01

    The distributed computer system described in this paper is a set of computer nodes interconnected in an interconnection network via packet-switching interfaces.The nodes communicate with each other by means of message-passing protocols.This paper presents the implementation of rendezvous facilities as high-level primitives provided by a parallel programming language to support interprocess communication and synchronization.

  11. Techniques for operative correction of proximal junctional kyphosis of the upper thoracic spine.

    Science.gov (United States)

    McClendon, Jamal; O'Shaughnessy, Brian A; Sugrue, Patrick A; Neal, Chris J; Acosta, Frank L; Koski, Tyler R; Ondra, Stephen L

    2012-02-15

    Retrospective study of a consecutive series of patients treated for proximal junctional kyphosis (PJK) of the upper thoracic and cervicothoracic spine. To discuss corrective techniques for the management of symptomatic kyphosis at the junction of fused and mobile segments of the upper thoracic and cervicothoracic spine in patients who complain of pain, neurological deficit, ambulatory difficulty, and/or social isolation. PJK is an unfortunately common, but important, complication seen in long instrumented fusions to the upper thoracic and cervicothoracic spine. Although often asymptomatic, its incidence and prevalence warrant a discussion on treatment options for symptomatic patients. After the institutional review board confirmed approval, we retrospectively analyzed patients who received treatment of PJK from 2003 to 2009. Segmental instrumentation and intraoperative neurophysiological monitoring were used in all patients. Data acquisition was performed by reviewing electronic medical records and radiographs. Inclusion criteria were patients who underwent surgical correction of PJK of the cervicothoracic and upper thoracic spine and had more than 2-year follow-up. Preoperative lumbar lordosis, preoperative thoracic kyphosis, pre- and postoperative sagittal balance, and sagittal proximal junctional Cobb angle were obtained. All corrective procedures were performed in 2 stages, each patient receiving cervical traction between cases. Inclusion criteria were met in 7 patients (5 women and 2 men), with mean age of 55 years (range, 18-80 years). Six patients received multilevel Smith-Petersen osteotomies, with 2 patients receiving rib osteotomies, and 1 patient received a vertebral column resection. The mean preoperative and postoperative proximal junctional Cobb angles were 45° (range, 14°-89.7°) and 14° (range, 3.0°-38.0°), respectively. The mean degree of correction was 31° (range, 11°-79.2°). All patients had maintained or improved sagittal balance. No

  12. A linear quadratic Gaussian with loop transfer recovery proximity operations autopilot for spacecraft. M.S. Thesis - MIT

    Science.gov (United States)

    Chen, George T.

    1987-01-01

    An automatic control scheme for spacecraft proximity operations is presented. The controller is capable of holding the vehicle at a prescribed location relative to a target, or maneuvering it to a different relative position using straight line-of-sight translations. The autopilot uses a feedforward loop to initiate and terminate maneuvers, and for operations at nonequilibrium set-points. A multivariate feedback loop facilitates precise position and velocity control in the presence of sensor noise. The feedback loop is formulated using the Linear Quadratic Gaussian (LQG) with Loop Transfer Recovery (LTR) design procedure. Linear models of spacecraft dynamics, adapted from Clohessey-Wiltshire Equations, are augmented and loop shaping techniques are applied to design a target feedback loop. The loop transfer recovery procedure is used to recover the frequency domain properties of the target feedback loop. The resulting compensator is integrated into an autopilot which is tested in a high fidelity Space Shuttle Simulator. The autopilot performance is evaluated for a variety of proximity operations tasks envisioned for future Shuttle flights.

  13. Cassini Operational Sun Sensor Risk Management During Proximal Orbit Saturn Ring Plane Crossings

    Science.gov (United States)

    Bates, David M.

    2016-01-01

    NASA's Cassini Spacecraft, launched on October 15th, 1997 which arrived at Saturn on June 30th, 2004, is the largest and most ambitious interplanetary spacecraft in history. As the first spacecraft to achieve orbit at Saturn, Cassini has collected science data throughout its four-year prime mission (2004–08), and has since been approved for a first and second extended mission through 2017. As part of the final extended missions, Cassini will begin an aggressive and exciting campaign of high inclination, low altitude flybys within the inner most rings of Saturn, skimming Saturn’s outer atmosphere, until the spacecraft is finally disposed of via planned impact with the planet. This final campaign, known as the proximal orbits, requires a strategy for managing the Sun Sensor Assembly (SSA) health, the details of which are presented in this paper.

  14. A review of cooperative and uncooperative spacecraft pose determination techniques for close-proximity operations

    Science.gov (United States)

    Opromolla, Roberto; Fasano, Giancarmine; Rufino, Giancarlo; Grassi, Michele

    2017-08-01

    The capability of an active spacecraft to accurately estimate its relative position and attitude (pose) with respect to an active/inactive, artificial/natural space object (target) orbiting in close-proximity is required to carry out various activities like formation flying, on-orbit servicing, active debris removal, and space exploration. According to the specific mission scenario, the pose determination task involves both theoretical and technological challenges related to the search for the most suitable algorithmic solution and sensor architecture, respectively. As regards the latter aspect, electro-optical sensors represent the best option as their use is compatible with mass and power limitation of micro and small satellites, and their measurements can be processed to estimate all the pose parameters. Overall, the degree of complexity of the challenges related to pose determination largely varies depending on the nature of the targets, which may be actively/passively cooperative, uncooperative but known, or uncooperative and unknown space objects. In this respect, while cooperative pose determination has been successfully demonstrated in orbit, the uncooperative case is still under study by universities, research centers, space agencies and private companies. However, in both the cases, the demand for space applications involving relative navigation maneuvers, also in close-proximity, for which pose determination capabilities are mandatory, is significantly increasing. In this framework, a review of state-of-the-art techniques and algorithms developed in the last decades for cooperative and uncooperative pose determination by processing data provided by electro-optical sensors is herein presented. Specifically, their main advantages and drawbacks in terms of achieved performance, computational complexity, and sensitivity to variability of pose and target geometry, are highlighted.

  15. Antimicrobial residues in animal waste and water resources proximal to large-scale swine and poultry feeding operations

    Science.gov (United States)

    Campagnolo, E.R.; Johnson, K.R.; Karpati, A.; Rubin, C.S.; Kolpin, D.W.; Meyer, M.T.; Esteban, J. Emilio; Currier, R.W.; Smith, K.; Thu, K.M.; McGeehin, M.

    2002-01-01

    Expansion and intensification of large-scale animal feeding operations (AFOs) in the United States has resulted in concern about environmental contamination and its potential public health impacts. The objective of this investigation was to obtain background data on a broad profile of antimicrobial residues in animal wastes and surface water and groundwater proximal to large-scale swine and poultry operations. The samples were measured for antimicrobial compounds using both radioimmunoassay and liquid chromatography/electrospray ionization-mass spectrometry (LC/ESI-MS) techniques. Multiple classes of antimicrobial compounds (commonly at concentrations of >100 μg/l) were detected in swine waste storage lagoons. In addition, multiple classes of antimicrobial compounds were detected in surface and groundwater samples collected proximal to the swine and poultry farms. This information indicates that animal waste used as fertilizer for crops may serve as a source of antimicrobial residues for the environment. Further research is required to determine if the levels of antimicrobials detected in this study are of consequence to human and/or environmental ecosystems. A comparison of the radioimmunoassay and LC/ESI-MS analytical methods documented that radioimmunoassay techniques were only appropriate for measuring residues in animal waste samples likely to contain high levels of antimicrobials. More sensitive LC/ESI-MS techniques are required in environmental samples, where low levels of antimicrobial residues are more likely.

  16. Methodology for Developing a Probabilistic Risk Assessment Model of Spacecraft Rendezvous and Dockings

    Science.gov (United States)

    Farnham, Steven J., II; Garza, Joel, Jr.; Castillo, Theresa M.; Lutomski, Michael

    2011-01-01

    In 2007 NASA was preparing to send two new visiting vehicles carrying logistics and propellant to the International Space Station (ISS). These new vehicles were the European Space Agency s (ESA) Automated Transfer Vehicle (ATV), the Jules Verne, and the Japanese Aerospace and Explorations Agency s (JAXA) H-II Transfer Vehicle (HTV). The ISS Program wanted to quantify the increased risk to the ISS from these visiting vehicles. At the time, only the Shuttle, the Soyuz, and the Progress vehicles rendezvoused and docked to the ISS. The increased risk to the ISS was from an increase in vehicle traffic, thereby, increasing the potential catastrophic collision during the rendezvous and the docking or berthing of the spacecraft to the ISS. A universal method of evaluating the risk of rendezvous and docking or berthing was created by the ISS s Risk Team to accommodate the increasing number of rendezvous and docking or berthing operations due to the increasing number of different spacecraft, as well as the future arrival of commercial spacecraft. Before the first docking attempt of ESA's ATV and JAXA's HTV to the ISS, a probabilistic risk model was developed to quantitatively calculate the risk of collision of each spacecraft with the ISS. The 5 rendezvous and docking risk models (Soyuz, Progress, Shuttle, ATV, and HTV) have been used to build and refine the modeling methodology for rendezvous and docking of spacecrafts. This risk modeling methodology will be NASA s basis for evaluating the addition of future ISS visiting spacecrafts hazards, including SpaceX s Dragon, Orbital Science s Cygnus, and NASA s own Orion spacecraft. This paper will describe the methodology used for developing a visiting vehicle risk model.

  17. In-hospital mortality analysis in patients with proximal femoral fracture operatively treated by hip arthroplasty procedure

    Directory of Open Access Journals (Sweden)

    Starčević Srdjan

    2016-01-01

    Full Text Available Background/Aim. Hip fracture remains the leading cause of death in trauma among elderly population and is a great burden to national health services. In-patient death analysis is important to evaluate risk factors, make appropriate selection and perform adequate treatment of infections for patients to be operated. The aim of this study was to analyze in-hospital mortality in proximal femoral fracture patients operatively treated with hip arthroplasty procedure. Methods. We followed 622 consecutive patients, and collected data about age, gender, the presence of infection preoperatively and postoperatively, American Society of Anesthesiologists (ASA score, diabetes mellitus and the type of surgical procedure. Postoperative infections included pneumonia, urinary tract infections, surgical site infections and sepsis. Results. We found a statistically significant influence of preoperative and postoperative infection presence for in-patient mortality with relative risk for lethal outcome of 4.53 (95% CI: 1.44-14.22 for patients with preoperative infection and 7.5 (95% CI: 1.90-29.48 for patients with postoperative infection. We did not confirm a statistically significant influence of age, gender, ASA score, diabetes mellitus or the type of surgical procedure for increased mortality rate. Conclusion. Adequate preoperative selection, risk evaluation and adequate treatment of infections are of the key importance for lowering the risk of death in patients operated due to proximal femoral fracture and treated by hip arthroplasty procedures. Special attention is to be paid for the presence of preoperative and postoperative infections in patients operatively treated due to the risk for increased in-hospital mortality.

  18. An Extragradient Method and Proximal Point Algorithm for Inverse Strongly Monotone Operators and Maximal Monotone Operators in Banach Spaces

    Directory of Open Access Journals (Sweden)

    Plubtieng Somyot

    2009-01-01

    Full Text Available Abstract We introduce an iterative scheme for finding a common element of the solution set of a maximal monotone operator and the solution set of the variational inequality problem for an inverse strongly-monotone operator in a uniformly smooth and uniformly convex Banach space, and then we prove weak and strong convergence theorems by using the notion of generalized projection. The result presented in this paper extend and improve the corresponding results of Kamimura et al. (2004, and Iiduka and Takahashi (2008. Finally, we apply our convergence theorem to the convex minimization problem, the problem of finding a zero point of a maximal monotone operator and the complementary problem.

  19. An Extragradient Method and Proximal Point Algorithm for Inverse Strongly Monotone Operators and Maximal Monotone Operators in Banach Spaces

    Directory of Open Access Journals (Sweden)

    Somyot Plubtieng

    2009-01-01

    Full Text Available We introduce an iterative scheme for finding a common element of the solution set of a maximal monotone operator and the solution set of the variational inequality problem for an inverse strongly-monotone operator in a uniformly smooth and uniformly convex Banach space, and then we prove weak and strong convergence theorems by using the notion of generalized projection. The result presented in this paper extend and improve the corresponding results of Kamimura et al. (2004, and Iiduka and Takahashi (2008. Finally, we apply our convergence theorem to the convex minimization problem, the problem of finding a zero point of a maximal monotone operator and the complementary problem.

  20. RENDEZVOUS ACCURACY OF THE OMEGA NAVIGATION SYSTEM.

    Science.gov (United States)

    yards, with the time of day or environment having no apparent effect on the rendezvous errors. The Haiku -Summit pair showed a greater variation in...input amplitude was marginal. During this experiment the majority of the AGC readings were above this value for receptions from Haiku . The additional...electrical noise in the helicopter and an inadequate antenna combined with the already weak Haiku signal aided in making the Haiku -Summit readings marginal. (Author)

  1. Introducing AN Agent-Based Object Recognition Operator for Proximity Analysis

    Science.gov (United States)

    Behzadi, S.; Ali. Alesheikh, A.

    2013-09-01

    Object selection is a basic procedure in a Geographic Information System (GIS). Most current methods for doing so, select objects in two phases: create a simple distance-bounded geometric buffer; and intersect it with available features. This paper introduces a novel and intelligent selection operator based on the autonomy of the agent-based approach. The proposed operator recognizes objects around one object only in one step. In the proposed approach, each point object acts as an agent-automata object. It then senses its vicinity and identifies the surrounding objects. To assess the proposed model, the operator is designed, implemented, and evaluated in a case study. Finally, the results are evaluated and presented in details in the paper.

  2. Rendezvous Integration Complexities of NASA Human Flight Vehicles

    Science.gov (United States)

    Brazzel, Jack P.; Goodman, John L.

    2009-01-01

    Propellant-optimal trajectories, relative sensors and navigation, and docking/capture mechanisms are rendezvous disciplines that receive much attention in the technical literature. However, other areas must be considered. These include absolute navigation, maneuver targeting, attitude control, power generation, software development and verification, redundancy management, thermal control, avionics integration, robotics, communications, lighting, human factors, crew timeline, procedure development, orbital debris risk mitigation, structures, plume impingement, logistics, and in some cases extravehicular activity. While current and future spaceflight programs will introduce new technologies and operations concepts, the complexity of integrating multiple systems on multiple spacecraft will remain. The systems integration task may become more difficult as increasingly complex software is used to meet current and future automation, autonomy, and robotic operation requirements.

  3. Trusted Remote Operation of Proximate Emergency Robots (TROOPER): DARPA Robotics Challenge

    Science.gov (United States)

    2015-12-01

    controllers attempt to simultaneously reserve the same joint, a priority scheme is used to determine which controller is allowed to take ownership...effectors, footsteps that show a created walking path, and a pyramid -like line of sight indicator. When running the robot, the operator will spend the...We developed simple footstep interpolation schemes that generate sequences of foot placement goals that will move the robot from point A to point B

  4. Hyperbolic Rendezvous at Mars: Risk Assessments and Mitigation Strategies

    Science.gov (United States)

    Jedrey, Ricky; Landau, Damon; Whitley, Ryan

    2015-01-01

    Given the current interest in the use of flyby trajectories for human Mars exploration, a key requirement is the capability to execute hyperbolic rendezvous. Hyperbolic rendezvous is used to transport crew from a Mars centered orbit, to a transiting Earth bound habitat that does a flyby. Representative cases are taken from future potential missions of this type, and a thorough sensitivity analysis of the hyperbolic rendezvous phase is performed. This includes early engine cutoff, missed burn times, and burn misalignment. A finite burn engine model is applied that assumes the hyperbolic rendezvous phase is done with at least two burns.

  5. CAM operated tool for proximate or remote holding of an object

    Energy Technology Data Exchange (ETDEWEB)

    Schrum, P.B.; Gajdzik, G.P. Jr.

    1995-12-31

    A tool for releasably holding an object includes a receptacle having an outer sleeve and a rotatable inner sleeve. The inner sleeve is coaxially positioned within the outer sleeve and includes a locking member. An insert which is adapted to be operably associated with the receptacle includes a cam. The cam includes a guide and a slot so that when the cam is inserted into the inner sleeve, the guide aligns the locking member with the slot allowing the locking member to engage the slot thereby holding the receptacle and the insert together.

  6. The Selfish Goal: autonomously operating motivational structures as the proximate cause of human judgment and behavior.

    Science.gov (United States)

    Huang, Julie Y; Bargh, John A

    2014-04-01

    We propose the Selfish Goal model, which holds that a person's behavior is driven by psychological processes called goals that guide his or her behavior, at times in contradictory directions. Goals can operate both consciously and unconsciously, and when activated they can trigger downstream effects on a person's information processing and behavioral possibilities that promote only the attainment of goal end-states (and not necessarily the overall interests of the individual). Hence, goals influence a person as if the goals themselves were selfish and interested only in their own completion. We argue that there is an evolutionary basis to believe that conscious goals evolved from unconscious and selfish forms of pursuit. This theoretical framework predicts the existence of unconscious goal processes capable of guiding behavior in the absence of conscious awareness and control (the automaticity principle), the ability of the most motivating or active goal to constrain a person's information processing and behavior toward successful completion of that goal (the reconfiguration principle), structural similarities between conscious and unconscious goal pursuit (the similarity principle), and goal influences that produce apparent inconsistencies or counterintuitive behaviors in a person's behavior extended over time (the inconsistency principle). Thus, we argue that a person's behaviors are indirectly selected at the goal level but expressed (and comprehended) at the individual level.

  7. An Image-Based Sensor System for Autonomous Rendez-Vous with Uncooperative Satellites

    CERN Document Server

    Miravet, Carlos; Krouch, Eloise; del Cura, Juan Manuel

    2008-01-01

    In this paper are described the image processing algorithms developed by SENER, Ingenieria y Sistemas to cope with the problem of image-based, autonomous rendez-vous (RV) with an orbiting satellite. The methods developed have a direct application in the OLEV (Orbital Life Extension Extension Vehicle) mission. OLEV is a commercial mission under development by a consortium formed by Swedish Space Corporation, Kayser-Threde and SENER, aimed to extend the operational life of geostationary telecommunication satellites by supplying them control, navigation and guidance services. OLEV is planned to use a set of cameras to determine the angular position and distance to the client satellite during the complete phases of rendez-vous and docking, thus enabling the operation with satellites not equipped with any specific navigational aid to provide support during the approach. The ability to operate with un-equipped client satellites significantly expands the range of applicability of the system under development, compar...

  8. Application of fuzzy logic-neural network based reinforcement learning to proximity and docking operations: Translational controller results

    Science.gov (United States)

    Jani, Yashvant

    1992-01-01

    The reinforcement learning techniques developed at Ames Research Center are being applied to proximity and docking operations using the Shuttle and Solar Maximum Mission (SMM) satellite simulation. In utilizing these fuzzy learning techniques, we also use the Approximate Reasoning based Intelligent Control (ARIC) architecture, and so we use two terms interchangeable to imply the same. This activity is carried out in the Software Technology Laboratory utilizing the Orbital Operations Simulator (OOS). This report is the deliverable D3 in our project activity and provides the test results of the fuzzy learning translational controller. This report is organized in six sections. Based on our experience and analysis with the attitude controller, we have modified the basic configuration of the reinforcement learning algorithm in ARIC as described in section 2. The shuttle translational controller and its implementation in fuzzy learning architecture is described in section 3. Two test cases that we have performed are described in section 4. Our results and conclusions are discussed in section 5, and section 6 provides future plans and summary for the project.

  9. Orion Handling Qualities During ISS Rendezvous and Docking

    Science.gov (United States)

    Hart, Jeremy J.; Stephens, J. P.; Spehar, P.; Bilimoria, K.; Foster, C.; Gonzalex, R.; Sullivan, K.; Jackson, B.; Brazzel, J.; Hart, J.

    2011-01-01

    The Orion spacecraft was designed to rendezvous with multiple vehicles in low earth orbit (LEO) and beyond. To perform the required rendezvous and docking task, Orion must provide enough control authority to perform coarse translational maneuvers while maintaining precision to perform the delicate docking corrections. While Orion has autonomous docking capabilities, it is expected that final approach and docking operations with the International Space Station (ISS) will initially be performed in a manual mode. A series of evaluations was conducted by NASA and Lockheed Martin at the Johnson Space Center to determine the handling qualities (HQ) of the Orion spacecraft during different docking and rendezvous conditions using the Cooper-Harper scale. This paper will address the specifics of the handling qualities methodology, vehicle configuration, scenarios flown, data collection tools, and subject ratings and comments. The initial Orion HQ assessment examined Orion docking to the ISS. This scenario demonstrates the Translational Hand Controller (THC) handling qualities of Orion. During this initial assessment, two different scenarios were evaluated. The first was a nominal docking approach to a stable ISS, with Orion initializing with relative position dispersions and a closing rate of approximately 0.1 ft/sec. The second docking scenario was identical to the first, except the attitude motion of the ISS was modeled to simulate a stress case ( 1 degree deadband per axis and 0.01 deg/sec rate deadband per axis). For both scenarios, subjects started each run on final approach at a docking port-to-port range of 20 ft. Subjects used the THC in pulse mode with cues from the docking camera image, window views, and range and range rate data displayed on the Orion display units. As in the actual design, the attitude of the Orion vehicle was held by the automated flight control system at 0.5 degree deadband per axis. Several error sources were modeled including Reaction

  10. Use of a Proximity Sensor Switch for "Hands Free" Operation of Computer-Based Video Prompting by Young Adults with Moderate Intellectual Disability

    Science.gov (United States)

    Ivey, Alexandria N.; Mechling, Linda C.; Spencer, Galen P.

    2015-01-01

    In this study, the effectiveness of a "hands free" approach for operating video prompts to complete multi-step tasks was measured. Students advanced the video prompts by using a motion (hand wave) over a proximity sensor switch. Three young adult females with a diagnosis of moderate intellectual disability participated in the study.…

  11. Rendezvous, un juego de Lewis Carroll

    Directory of Open Access Journals (Sweden)

    José Manuel Sánchez Muñoz

    2011-10-01

    Full Text Available Todos en mayor o menor medida asociamos el nombre de Lewis Carrolla la literatura, sobre todo a la de temática infantil, con títulos a sus espaldas como Alicia en el País de las Maravillas, Alicia a través del espejo, o La Caza del Snark. Pero además de literato, Lewis Carrol fue un hombre con bastantes inquietudes en torno a la matemática, la lógica y el pensamiento filosófico. Pero no todo el mundo es conocedor de su faceta como creativo en el campo de los juegos. Rendezvous es una de sus más sorprendentes invenciones,un juego de inteligencia para todos los públicos, cuyas directrices hacen de él un entretenimiento bastante original.

  12. Rendezvous, un juego de Lewis Carroll

    OpenAIRE

    José Manuel Sánchez Muñoz

    2011-01-01

    Todos en mayor o menor medida asociamos el nombre de Lewis Carrolla la literatura, sobre todo a la de temática infantil, con títulos a sus espaldas como Alicia en el País de las Maravillas, Alicia a través del espejo, o La Caza del Snark. Pero además de literato, Lewis Carrol fue un hombre con bastantes inquietudes en torno a la matemática, la lógica y el pensamiento filosófico. Pero no todo el mundo es conocedor de su faceta como creativo en el campo de los juegos. Rendezvous es una de sus más...

  13. Adaptive control for autonomous rendezvous of spacecraft on elliptical orbit

    Institute of Scientific and Technical Information of China (English)

    Shan Lu; Shijie Xu

    2009-01-01

    A strategy for spacecraft autonomous rendezvous on an elliptical orbit in situation of no orbit information is developed. Lawden equation is used to describe relative motion of two spacecraft. Then an adaptive gain factor is introduced, and an adaptive control law for autonomous rendezvous on the elliptical orbit is designed using Lyapunov approach. The relative motion is proved to be ultimately bounded under this control law, and the final relative position error can achieve the expected magnitude. Simulation results indicate that the adaptive control law can realize autonomous rendezvous on the elliptical orbit with relative state information only.

  14. Flash 3D Rendezvous and Docking Sensor Project

    Data.gov (United States)

    National Aeronautics and Space Administration — With NASA's exploration initiative to return to Lunar Exploration and eventual human exploration of Mars, NASA has an increased need for an Autonomous Rendezvous and...

  15. AggieSat: Autonomous Rendezvous and Docking Technology Demonstrator Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Current autonomous rendezvous and docking (AR&D) capability in low Earth orbit (LEO) is constrained by sensor and effector mass, power, and accuracy limits. To...

  16. SPHERES MOSR Rendezvous and Docking with the OS (RDOS) Project

    Data.gov (United States)

    National Aeronautics and Space Administration — In order to support the tools needed to develop the Mars Sample Return (MSR) rendezvous and capture of the Orbiting Sample (OS), Aurora and MIT Space Systems Lab...

  17. Optimal Rendezvous and Docking Simulator for Elliptical Orbits Project

    Data.gov (United States)

    National Aeronautics and Space Administration — It is proposed to develop and implement a simulation of spacecraft rendezvous and docking guidance, navigation, and control in elliptical orbit. The foundation of...

  18. Distributed consensus on minimum time rendezvous via cyclic alternating projection

    OpenAIRE

    Hu, Chunhe; Chen, Zongji

    2014-01-01

    In this paper, we propose a distributed algorithm to solve planar minimum time multi-vehicle rendezvous problem with non-identical velocity constraints on cyclic digraph (topology). Motivated by the cyclic alternating projection method that can compute a point's projection on the intersection of some convex sets, we transform the minimum time rendezvous problem into finding the distance between the position plane and the intersection of several second-order cones in position-time space. The d...

  19. Rendezvous missions to temporarily captured near Earth asteroids

    Science.gov (United States)

    Brelsford, S.; Chyba, M.; Haberkorn, T.; Patterson, G.

    2016-04-01

    Missions to rendezvous with or capture an asteroid present significant interest both from a geophysical and safety point of view. They are key to the understanding of our solar system and are stepping stones for interplanetary human flight. In this paper, we focus on a rendezvous mission with 2006 RH120, an asteroid classified as a Temporarily Captured Orbiter (TCO). TCOs form a new population of near Earth objects presenting many advantages toward that goal. Prior to the mission, we consider the spacecraft hibernating on a Halo orbit around the Earth-Moon's L2 libration point. The objective is to design a transfer for the spacecraft from the parking orbit to rendezvous with 2006 RH120 while minimizing the fuel consumption. Our transfers use indirect methods, based on the Pontryagin Maximum Principle, combined with continuation techniques and a direct method to address the sensitivity of the initialization. We demonstrate that a rendezvous mission with 2006 RH120 can be accomplished with low delta-v. This exploratory work can be seen as a first step to identify good candidates for a rendezvous on a given TCO trajectory.

  20. Robust adaptive control of spacecraft proximity maneuvers under dynamic coupling and uncertainty

    Science.gov (United States)

    Sun, Liang; Huo, Wei

    2015-11-01

    This paper provides a solution for the position tracking and attitude synchronization problem of the close proximity phase in spacecraft rendezvous and docking. The chaser spacecraft must be driven to a certain fixed position along the docking port direction of the target spacecraft, while the attitude of the two spacecraft must be synchronized for subsequent docking operations. The kinematics and dynamics for relative position and relative attitude are modeled considering dynamic coupling, parametric uncertainties and external disturbances. The relative motion model has a new form with a novel definition of the unknown parameters. An original robust adaptive control method is developed for the concerned problem, and a proof of the asymptotic stability is given for the six degrees of freedom closed-loop system. A numerical example is displayed in simulation to verify the theoretical results.

  1. SEPS comet rendezvous performance assessment. [Solar Electric Propulsion System

    Science.gov (United States)

    Sauer, C. G., Jr.

    1980-01-01

    This paper presents an assessment of delivered payload capability for a number of selected rendezvous missions to periodic comets with launch opportunities through the years 1986-1996. These missions are chosen using a selection criteria that considers both expected scientific interest and earth-based sighting considerations. Some 22 mission opportunities are found that satisfies the selection criteria. Spacecraft performance is presented for each mission opportunity based on use of a space shuttle, a twin stage inertial-upper-stage, and a conceptual solar-electric-propulsion-system with a nominal rendezvous 50 days before comet perihelion. Additional trajectory and propulsion enhancements are investigated for several comet rendezvous missions in order to improve spacecraft performance. An indirect transfer trajectory for an Encke mission is shown to offer substantial delivered payload. In addition the use of concentrator solar arrays is considered for several of the more interesting comet missions.

  2. Endoskopisk ultralydvejledt rendezvous til intern drænage ved galdevejsobstruktion

    DEFF Research Database (Denmark)

    Knudsen, Marie Høxbro; Vilmann, Peter; Hassan, Hazem

    2015-01-01

    Endoscopic ultrasound guided rendezvous for biliary drainage Endoscopic retrograde cholangiography (ERCP) is currently standard treatment for biliary drainage. Endoscopic ultrasound guided rendezvous (EUS-RV) is a novel method to overcome an unsuccessful biliary drainage procedure. Under endoscop...

  3. Proximal Hypospadias

    Directory of Open Access Journals (Sweden)

    Kate H. Kraft

    2011-01-01

    Full Text Available Hypospadias results from abnormal development of the penis that leaves the urethral meatus proximal to its normal glanular position. Meatal position may be located anywhere along the penile shaft, but more severe forms of hypospadias may have a urethral meatus located at the scrotum or perineum. The spectrum of abnormalities may also include ventral curvature of the penis, a dorsally redundant prepuce, and atrophic corpus spongiosum. Due to the severity of these abnormalities, proximal hypospadias often requires more extensive reconstruction in order to achieve an anatomically and functionally successful result. We review the spectrum of proximal hypospadias etiology, presentation, correction, and possible associated complications.

  4. Ivar asteroid rendezvous mission system scenario and trajectory design

    Institute of Scientific and Technical Information of China (English)

    崔平远; 李立涛; 崔祜涛; 栾恩杰; 吴伟仁; 田玉龙

    2003-01-01

    The asteroid exploration opportunities are searched and calculated with launch dates in 2006 to2010, and with asteroid Ivar 1627 as the target, the spacecraft and its subsystems are designed and analyzed,and the transfer trajectory is designed using △VEGA technology for the asteroid rendezvous. The design resultssatisfied the energy requirements for small explorers.

  5. Vision Based Navigation Sensors for Spacecraft Rendezvous and Docking

    DEFF Research Database (Denmark)

    Benn, Mathias

    is a technological demonstration mission, where all aspects of space rendezvous and docking to both a cooperative and a non-cooperative target is researched, with the use of novel methods, instruments and technologies. Amongst other equipment, DTU has delivered a vision based sensor package to the Main spacecraft...

  6. SPARTAN: A High-Fidelity Simulation for Automated Rendezvous and Docking Applications

    Science.gov (United States)

    Turbe, Michael A.; McDuffie, James H.; DeKock, Brandon K.; Betts, Kevin M.; Carrington, Connie K.

    2007-01-01

    bd Systems (a subsidiary of SAIC) has developed the Simulation Package for Autonomous Rendezvous Test and ANalysis (SPARTAN), a high-fidelity on-orbit simulation featuring multiple six-degree-of-freedom (6DOF) vehicles. SPARTAN has been developed in a modular fashion in Matlab/Simulink to test next-generation automated rendezvous and docking guidance, navigation,and control algorithms for NASA's new Vision for Space Exploration. SPARTAN includes autonomous state-based mission manager algorithms responsible for sequencing the vehicle through various flight phases based on on-board sensor inputs and closed-loop guidance algorithms, including Lambert transfers, Clohessy-Wiltshire maneuvers, and glideslope approaches The guidance commands are implemented using an integrated translation and attitude control system to provide 6DOF control of each vehicle in the simulation. SPARTAN also includes high-fidelity representations of a variety of absolute and relative navigation sensors that maybe used for NASA missions, including radio frequency, lidar, and video-based rendezvous sensors. Proprietary navigation sensor fusion algorithms have been developed that allow the integration of these sensor measurements through an extended Kalman filter framework to create a single optimal estimate of the relative state of the vehicles. SPARTAN provides capability for Monte Carlo dispersion analysis, allowing for rigorous evaluation of the performance of the complete proposed AR&D system, including software, sensors, and mechanisms. SPARTAN also supports hardware-in-the-loop testing through conversion of the algorithms to C code using Real-Time Workshop in order to be hosted in a mission computer engineering development unit running an embedded real-time operating system. SPARTAN also contains both runtime TCP/IP socket interface and post-processing compatibility with bdStudio, a visualization tool developed by bd Systems, allowing for intuitive evaluation of simulation results. A

  7. Use of industrial robots for hardware-in-the-loop simulation of satellite rendezvous and docking

    Science.gov (United States)

    Ma, Ou; Flores-Abad, Angel; Boge, Toralf

    2012-12-01

    One of the most challenging and risky operations for spacecraft is to perform rendezvous and docking autonomously in space. To ensure a safe and reliable operation, such a mission must be carefully designed and thoroughly verified before a real space mission can be launched. This paper describes the control strategy for achieving high fidelity contact dynamics simulation of a new, robotics-based, hardware-in-the-loop (HIL) rendezvous and docking simulation facility that uses two industrial robots to physically simulate the 6-DOF dynamic maneuvering of two docking satellites. The facility is capable of physically simulating the final approaching within a 25-meter range and the entire docking/capturing process for a satellite on-orbit servicing mission. The key difficulties of using industrial robots for high-fidelity HIL contact dynamics simulation were found and different solution techniques were investigated in the presented project. An admittance control method was proposed to achieve the goal of making the robots in the HIL simulation process match the impedance of the two docking satellites. Simulation study showed the effectiveness and performance of the proposed solution method.

  8. Inverse simulation system for evaluating handling qualities during rendezvous and docking

    Science.gov (United States)

    Zhou, Wanmeng; Wang, Hua; Thomson, Douglas; Tang, Guojin; Zhang, Fan

    2017-08-01

    The traditional method used for handling qualities assessment of manned space vehicles is too time-consuming to meet the requirements of an increasingly fast design process. In this study, a rendezvous and docking inverse simulation system to assess the handling qualities of spacecraft is proposed using a previously developed model-predictive-control architecture. By considering the fixed discrete force of the thrusters of the system, the inverse model is constructed using the least squares estimation method with a hyper-ellipsoidal restriction, the continuous control outputs of which are subsequently dispersed by pulse width modulation with sensitivity factors introduced. The inputs in every step are deemed constant parameters, and the method could be considered as a general method for solving nominal, redundant, and insufficient inverse problems. The rendezvous and docking inverse simulation is applied to a nine-degrees-of-freedom platform, and a novel handling qualities evaluation scheme is established according to the operation precision and astronauts' workload. Finally, different nominal trajectories are scored by the inverse simulation and an established evaluation scheme. The scores can offer theoretical guidance for astronaut training and more complex operation missions.

  9. Application of fuzzy logic-neural network based reinforcement learning to proximity and docking operations: Special approach/docking testcase results

    Science.gov (United States)

    Jani, Yashvant

    1993-01-01

    As part of the RICIS project, the reinforcement learning techniques developed at Ames Research Center are being applied to proximity and docking operations using the Shuttle and Solar Maximum Mission (SMM) satellite simulation. In utilizing these fuzzy learning techniques, we use the Approximate Reasoning based Intelligent Control (ARIC) architecture, and so we use these two terms interchangeably to imply the same. This activity is carried out in the Software Technology Laboratory utilizing the Orbital Operations Simulator (OOS) and programming/testing support from other contractor personnel. This report is the final deliverable D4 in our milestones and project activity. It provides the test results for the special testcase of approach/docking scenario for the shuttle and SMM satellite. Based on our experience and analysis with the attitude and translational controllers, we have modified the basic configuration of the reinforcement learning algorithm in ARIC. The shuttle translational controller and its implementation in ARIC is described in our deliverable D3. In order to simulate the final approach and docking operations, we have set-up this special testcase as described in section 2. The ARIC performance results for these operations are discussed in section 3 and conclusions are provided in section 4 along with the summary for the project.

  10. Experimental evidence for the effect of small wind turbine proximity and operation on bird and bat activity.

    Directory of Open Access Journals (Sweden)

    Jeroen Minderman

    Full Text Available The development of renewable energy technologies such as wind turbines forms a vital part of strategies to reduce greenhouse gas emissions worldwide. Although large wind farms generate the majority of wind energy, the small wind turbine (SWT, units generating <50 kW sector is growing rapidly. In spite of evidence of effects of large wind farms on birds and bats, effects of SWTs on wildlife have not been studied and are likely to be different due to their potential siting in a wider range of habitats. We present the first study to quantify the effects of SWTs on birds and bats. Using a field experiment, we show that bird activity is similar in two distance bands surrounding a sample of SWTs (between 6-18 m hub height and is not affected by SWT operation at the fine scale studied. At shorter distances from operating turbines (0-5 m, bat activity (measured as the probability of a bat "pass" per hour decreases from 84% (71-91% to 28% (11-54% as wind speed increases from 0 to 14 m/s. This effect is weaker at greater distances (20-25 m from operating turbines (activity decreases from 80% (65-89% to 59% (32-81%, and absent when they are braked. We conclude that bats avoid operating SWTs but that this effect diminishes within 20 m. Such displacement effects may have important consequences especially in landscapes where suitable habitat is limiting. Planning guidance for SWTs is currently lacking. Based on our results we recommend that they are sited at least 20 m away from potentially valuable bat habitat.

  11. Experimental evidence for the effect of small wind turbine proximity and operation on bird and bat activity.

    Science.gov (United States)

    Minderman, Jeroen; Pendlebury, Chris J; Pearce-Higgins, James W; Park, Kirsty J

    2012-01-01

    The development of renewable energy technologies such as wind turbines forms a vital part of strategies to reduce greenhouse gas emissions worldwide. Although large wind farms generate the majority of wind energy, the small wind turbine (SWT, units generating wind farms on birds and bats, effects of SWTs on wildlife have not been studied and are likely to be different due to their potential siting in a wider range of habitats. We present the first study to quantify the effects of SWTs on birds and bats. Using a field experiment, we show that bird activity is similar in two distance bands surrounding a sample of SWTs (between 6-18 m hub height) and is not affected by SWT operation at the fine scale studied. At shorter distances from operating turbines (0-5 m), bat activity (measured as the probability of a bat "pass" per hour) decreases from 84% (71-91%) to 28% (11-54%) as wind speed increases from 0 to 14 m/s. This effect is weaker at greater distances (20-25 m) from operating turbines (activity decreases from 80% (65-89%) to 59% (32-81%)), and absent when they are braked. We conclude that bats avoid operating SWTs but that this effect diminishes within 20 m. Such displacement effects may have important consequences especially in landscapes where suitable habitat is limiting. Planning guidance for SWTs is currently lacking. Based on our results we recommend that they are sited at least 20 m away from potentially valuable bat habitat.

  12. Space Shuttle Guidance, Navigation, and Rendezvous Knowledge Capture Reports. Revision 1

    Science.gov (United States)

    Goodman, John L.

    2011-01-01

    This document is a catalog and readers guide to lessons learned, experience, and technical history reports, as well as compilation volumes prepared by United Space Alliance personnel for the NASA/Johnson Space Center (JSC) Flight Dynamics Division.1 It is intended to make it easier for future generations of engineers to locate knowledge capture documentation from the Shuttle Program. The first chapter covers observations on documentation quality and research challenges encountered during the Space Shuttle and Orion programs. The second chapter covers the knowledge capture approach used to create many of the reports covered in this document. These chapters are intended to provide future flight programs with insight that could be used to formulate knowledge capture and management strategies. The following chapters contain descriptions of each knowledge capture report. The majority of the reports concern the Space Shuttle. Three are included that were written in support of the Orion Program. Most of the reports were written from the years 2001 to 2011. Lessons learned reports concern primarily the shuttle Global Positioning System (GPS) upgrade and the knowledge capture process. Experience reports on navigation and rendezvous provide examples of how challenges were overcome and how best practices were identified and applied. Some reports are of a more technical history nature covering navigation and rendezvous. They provide an overview of mission activities and the evolution of operations concepts and trajectory design. The lessons learned, experience, and history reports would be considered secondary sources by historians and archivists.

  13. Visualization of localized store-operated calcium entry in mouse astrocytes. Close proximity to the endoplasmic reticulum.

    Science.gov (United States)

    Golovina, Vera A

    2005-05-01

    Unloading of endoplasmic reticulum (ER) Ca(2+) stores activates influx of extracellular Ca(2+) through 'store-operated' Ca(2+) channels (SOCs) in the plasma membrane (PM) of most cells, including astrocytes. A key unresolved issue concerning SOC function is their spatial relationship to ER Ca(2+) stores. Here, using high resolution imaging with the membrane-associated Ca(2+) indicator, FFP-18, it is shown that store-operated Ca(2+) entry (SOCE) in primary cultured mouse cortical astrocytes occurs at plasma membrane-ER junctions. In the absence of extracellular Ca(2+), depletion of ER Ca(2+) stores using cyclopiazonic acid, an ER Ca(2+)-ATPase inhibitor, and caffeine transiently increases the sub-plasma-membrane Ca(2+) concentration ([Ca(2+)](SPM)) within a restricted space between the plasma membrane and adjacent ER. Restoration of extracellular Ca(2+) causes localized Ca(2+) influx that first increases [Ca(2+)](SPM) in the same restricted regions and then, with a delay, in ER-free regions. Antisense knockdown of the TRPC1 gene, proposed to encode endogenous SOCs, markedly reduces SOCE measured with Fura-2. High resolution immunocytochemistry with anti-TRPC1 antibody reveals that these TRPC-encoded SOCs are confined to the PM microdomains adjacent to the underlying 'junctional' ER. Thus, Ca(2+) entry through TRPC-encoded SOCs is closely linked, not only functionally, but also structurally, to the ER Ca(2+) stores.

  14. Finding rendezvous: An approach to locating Rocky Mountain Rendezvous sites through use of historic documents, geophysical survey, and LiDAR

    Science.gov (United States)

    Becker, Rory J.

    The general locations of the Rocky Mountain Rendezvous have been known to historians through documentary evidence since the mid to late 1800s. While the approximate locations of the rendezvous sites provided through historic documents have sufficed for the placement of signs and markers commemorating these annual events, archaeologists seeking to learn more about the yearly gathering of mountain men and native peoples through excavations need a more precise area to begin their search on the landscape. The exact locations of the Rocky Mountain Rendezvous are yet unknown in the sense of an archaeologist visiting a rendezvous site, trowel in hand, and hoping to unearth a small portion of fur trade history. In this study, I present a method for moving from the approximate locations for the Rocky Mountain Rendezvous sites provided by historic documents to identifying specific rendezvous archaeological sites through use of historic documents, geophysical survey, and GIS modeling. The first paper in this dissertation examines the demographics of the rendezvous. By use of historic documents, I present a method for estimating the number of people who may have been present at the rendezvous and winter camps from 1825 through 1829. By using this method for estimating people at the rendezvous, it becomes clear more native people were in attendance at the rendezvous and winter camps than trappers and traders of European descent. Once armed with the knowledge a rendezvous site should more closely resemble the archaeological signature of a Protohistoric native camp than a historic Euroamerican archaeological site, the search for a Protohistoric native camp to be mapped with geophysical survey instruments can begin. During this study, such a search resulted in the successful mapping of a portion of the camp surrounding a fur trading post on the banks of Powder River in east-central Wyoming. The final section in the dissertation will address the issue of where and how to focus a

  15. Modified rendezvous intrahepatic bile duct cannulation technique to pass a PTBD catheter in ERCP

    Institute of Scientific and Technical Information of China (English)

    Tae; Hoon; Lee; Sang-Heum; Park; Sae; Hwan; Lee; Chang-Kyun; Lee; Suck-Ho; Lee; Il-Kwun; Chung; Hong; Soo; Kim; Sun-Joo; Kim

    2010-01-01

    The rendezvous procedure combines an endoscopic technique with percutaneous transhepatic biliary drainage(PTBD).When a selective common bile duct cannulation fails,PTBD allows successful drainage and retrograde access for subsequent rendezvous techniques.Traditionally,rendezvous procedures such as the PTBDassisted over-the-wire cannulation method,or the parallel cannulation technique,may be available when a bile duct cannot be selectively cannulated.When selective intrahepatic bile duct(IHD) cannulation fai...

  16. A rendez-vous with history

    CERN Multimedia

    Corinne Pralavorio

    2010-01-01

    François de Rose, one of the founding fathers of CERN, visited the Laboratory. On this occasion, CERN organised a ceremony for his 100th birthday.   François de Rose, guided through the CERN control centre by Pierre Strubin from the Technology department. It was a moving, almost surreal, scene. On Wednesday 24 November, François de Rose, one of the founding fathers of CERN, visited the CERN Control Centre. In the early 1950s, François de Rose, a French diplomat, helped establish CERN along with some of the greatest physicists of the time. Standing in a futuristic room that only science fiction writers could have imagined when CERN began, the diplomat – who turned 100 only a few days before his visit - marvelled at the progress that had been made in nearly 60 years. Taking in the rush of operators – including those from PS, an accelerator which he inaugurated as President of the Council in 1960 – François de Rose...

  17. Prox-1 Automated Proximity Operations

    Science.gov (United States)

    2016-01-13

    a workmanship review with staff from the Georgia Tech Research Institute (GTRI) to evaluate all solder joints on the flight boards. Afterwards...public release. Report Document - Text Analysis Report Document - Text Analysis Appendix Documents 2. Thank You E-mail user Jan 08, 2016 19:58:04

  18. Determination of Eros Physical Parameters for Near Earth Asteroid Rendezvous Orbit Phase Navigation

    Science.gov (United States)

    Miller, J. K.; Antreasian, P. J.; Georgini, J.; Owen, W. M.; Williams, B. G.; Yeomans, D. K.

    1995-01-01

    Navigation of the orbit phase of the Near Earth steroid Rendezvous (NEAR) mission will re,quire determination of certain physical parameters describing the size, shape, gravity field, attitude and inertial properties of Eros. Prior to launch, little was known about Eros except for its orbit which could be determined with high precision from ground based telescope observations. Radar bounce and light curve data provided a rough estimate of Eros shape and a fairly good estimate of the pole, prime meridian and spin rate. However, the determination of the NEAR spacecraft orbit requires a high precision model of Eros's physical parameters and the ground based data provides only marginal a priori information. Eros is the principal source of perturbations of the spacecraft's trajectory and the principal source of data for determining the orbit. The initial orbit determination strategy is therefore concerned with developing a precise model of Eros. The original plan for Eros orbital operations was to execute a series of rendezvous burns beginning on December 20,1998 and insert into a close Eros orbit in January 1999. As a result of an unplanned termination of the rendezvous burn on December 20, 1998, the NEAR spacecraft continued on its high velocity approach trajectory and passed within 3900 km of Eros on December 23, 1998. The planned rendezvous burn was delayed until January 3, 1999 which resulted in the spacecraft being placed on a trajectory that slowly returns to Eros with a subsequent delay of close Eros orbital operations until February 2001. The flyby of Eros provided a brief glimpse and allowed for a crude estimate of the pole, prime meridian and mass of Eros. More importantly for navigation, orbit determination software was executed in the landmark tracking mode to determine the spacecraft orbit and a preliminary shape and landmark data base has been obtained. The flyby also provided an opportunity to test orbit determination operational procedures that will be

  19. 美国航天器交会技术研究%Study on Rendezvous Techniques of American Spacecraft

    Institute of Scientific and Technical Information of China (English)

    朱仁璋; 王鸿芳; 徐宇杰; 魏羽良

    2011-01-01

    The US rendezvous and docking techniques development can be divided into three stages: Gemini and Apollo spacecraft,Space Shuttle,and post-Shuttle projects.Progression of autonomous rendezvous technology is firstly based on developing various guidance and navigation sensors,in particular,laser sensors used during the final approach phase.Redundance in the Guidance,Navigation and Control system and fault detection and isolation method play an important role in trajectory safety.The projects being studied in this paper include Gemini,Apollo,Shuttle,post-Shuttle planned ones(Orion,Dragon,Cygnus,BlackSky,and on-orbit satellite servicing),and flight demonstrations(XSS-11,DART and Orbital Express),with focus on rendezvous trajectories and rendezvous sensors as well as rendezvous operation sequencing.%美国交会对接技术的发展可分为三个阶段:"双子座"与"阿波罗"飞船,航天飞机,以及后航天飞机时代的项目。自主交会技术的发展,首先基于多种制导和导航敏感器的研发,特别是用于最终逼近段的激光敏感器。制导、导航与控制系统的冗余,以及故障检测与隔离的方法,在轨迹安全性中起重要作用。文章研究美国自主交会方案,包括"双子座","阿波罗",航天飞机,后航天飞机时代计划的项目("猎户座","飞龙","天鹅座","黑天空"飞行器,在轨卫星服务使命),以及飞行验证项目(实验卫星系统-11,"自主交会技术验证飞行器","轨道快车"),研究重点为交会轨迹与交会敏感器以及交会运作程序。

  20. A six degree of freedom, plume-fuel optimal trajectory planner for spacecraft proximity operations using an A* node search. M.S. Thesis - MIT

    Science.gov (United States)

    Jackson, Mark Charles

    1994-01-01

    Spacecraft proximity operations are complicated by the fact that exhaust plume impingement from the reaction control jets of space vehicles can cause structural damage, contamination of sensitive arrays and instruments, or attitude misalignment during docking. The occurrence and effect of jet plume impingement can be reduced by planning approach trajectories with plume effects considered. An A* node search is used to find plume-fuel optimal trajectories through a discretized six dimensional attitude-translation space. A plume cost function which approximates jet plume isopressure envelopes is presented. The function is then applied to find relative costs for predictable 'trajectory altering' firings and unpredictable 'deadbanding' firings. Trajectory altering firings are calculated by running the spacecraft jet selection algorithm and summing the cost contribution from each jet fired. A 'deadbanding effects' function is defined and integrated to determine the potential for deadbanding impingement along candidate trajectories. Plume costs are weighed against fuel costs in finding the optimal solution. A* convergence speed is improved by solving approach trajectory problems in reverse time. Results are obtained on a high fidelity space shuttle/space station simulation. Trajectory following is accomplished by a six degree of freedom autopilot. Trajectories planned with, and without, plume costs are compared in terms of force applied to the target structure.

  1. Small Body GN&C Research Report: A Guidance and Control Technique for Small-Body Proximity Operations with Guaranteed Guidance Resolvability and Required Thruster Silent Time

    Science.gov (United States)

    Carson, John M., III; Ackmese, A. Behcet

    2005-01-01

    The guidance and control (G&C) algorithms for enabling small-body proximity operations are developed by using a model predictive control approach along with a convexification of the governing dynamics, control constraints, and trajectory/state constraints. The open-loop guidance is solved ahead of time or in a resolvable, real-time manner through the use of PWG (Pseudo Way-point Generation), a technique developed in this research. The PWG scheme ensures required thruster silent times during trajectory maneuvers. The feedback control is implemented to track the PWG trajectories in a manner that guarantees the resolvability for the open-loop problem, enabling the ability to update the G&C in a model-predictive manner. The schemes incorporate gravity models and thruster ring times into discrete dynamics that are solved as a optimal control problem to minimize fuel consumption or thruster energy expenditure. The optimal control problem is cast as an LMI (Linear Matrix Inequality) and then solved through Semi-Definite Programming techniques in a computationally efficient manner that provides convergence and constraint guarantees.

  2. The mobile agent rendezvous problem in the ring

    CERN Document Server

    Kranakis, Evangelos; Marcou, Euripides

    2010-01-01

    Mobile agent computing is being used in fields as diverse as artificial intelligence, computational economics and robotics. Agents' ability to adapt dynamically and execute asynchronously and autonomously brings potential advantages in terms of fault-tolerance, flexibility and simplicity. This monograph focuses on studying mobile agents as modelled in distributed systems research and in particular within the framework of research performed in the distributed algorithms community. It studies the fundamental question of how to achieve rendezvous, the gathering of two or more agents at the same n

  3. PREDICTION BASED CHANNEL-HOPPING ALGORITHM FOR RENDEZVOUS IN COGNITIVE RADIO NETWORKS

    Directory of Open Access Journals (Sweden)

    Dhananjay Kumar

    2012-12-01

    Full Text Available Most common works for rendezvous in cognitive radio networks deal only with two user scenarios involving two secondary users and variable primary users and aim at reducing the time-to-rendezvous. A common control channel for the establishment of communication is not considered and hence the work comes under the category of ‘Blind Rendezvous’. Our work deal with multi-user scenario and provides a methodology for the users to find each other in the very first time slot spent for rendezvous or otherwise called the firstattempt- rendezvous. The secondary users make use of the history of past communications to enable them to predict the frequency channel that the user expects the rendezvous user to be. Our approach prevents greedy decision making between the users involved by the use of a cut-off time period for attempting rendezvous. Simulation results show that the time-to-rendezvous (TTR is greatly reduced upon comparison with other popular rendezvous algorithms.

  4. Operative management of bilateral Salter-Harris type III fractures of the proximal phalanges of the great toes of a 10-year-old female ballet dancer: a case report.

    Science.gov (United States)

    Csonka, Akos; Sikarinkul, Eakachit; Gargyan, Istvan; Boa, Kristof; Varga, Endre

    2016-07-01

    Differentiation between the normal variant cleft epiphysis and Salter-Harris type III fracture of the first proximal phalanges of the foot in children might be challenging. The authors describe a case of a 10-year-old ballet dancer girl with bilateral epiphyseal segmentation of the first proximal phalanges of the foot, unresponsive to conservative treatment. Considered a nonhealing stress-induced fracture, operative treatment with closed reduction and Herbert screw insertion was chosen on both sides. Complete union was achieved, with significant reduction of pain. The presented case suggests that internal fixation can be a viable option in the treatment of the problem.

  5. Proximal renal tubular acidosis

    Science.gov (United States)

    Renal tubular acidosis - proximal; Type II RTA; RTA - proximal; Renal tubular acidosis type II ... by alkaline substances, mainly bicarbonate. Proximal renal tubular acidosis (Type II RTA) occurs when bicarbonate is not ...

  6. Terminal spacecraft rendezvous and capture with LASSO model predictive control

    Science.gov (United States)

    Hartley, Edward N.; Gallieri, Marco; Maciejowski, Jan M.

    2013-11-01

    The recently investigated ℓasso model predictive control (MPC) is applied to the terminal phase of a spacecraft rendezvous and capture mission. The interaction between the cost function and the treatment of minimum impulse bit is also investigated. The propellant consumption with ℓasso MPC for the considered scenario is noticeably less than with a conventional quadratic cost and control actions are sparser in time. Propellant consumption and sparsity are competitive with those achieved using a zone-based ℓ1 cost function, whilst requiring fewer decision variables in the optimisation problem than the latter. The ℓasso MPC is demonstrated to meet tighter specifications on control precision and also avoids the risk of undesirable behaviours often associated with pure ℓ1 stage costs.

  7. Some impulsive rendezvous trajectories and their possible optimality.

    Science.gov (United States)

    Peltier, J. P.

    1972-01-01

    Two- and three-impulse trajectories are investigated for fixed-time, fixed-angle rendezvous between vacant circular coplanar orbits, for trip angles less than, or equal to 2 pi in magnitude. For two-impulse trajectories, general features of the characteristic velocity function are outlined. Parameters of the intermediate orbit are reviewed. Attention is given to limiting cases. Computation of the adjoint system helps to define the domain of possible optimality foajectories: it is a closed domain in the trip time, trip angle plane. Waiting periods on terminal orbits are considered. The domain of possible optimality is defined using Lawden's primer vrtory. This domain extends to infinity if the radius ratio of terminal orbits is less than 15.6. Three-impulse trajectories are tried in cases where two-impulse trajectories, with or without cost, have been found nonoptimal. Improvements on the characteristic velocity are thus obtained.

  8. Short profile for the human spacecraft Soyuz-TMA rendezvous mission to the ISS☆

    Science.gov (United States)

    Murtazin, Rafail; Petrov, Nikolay

    2012-08-01

    Reduction of flight duration after insertion till docking to the ISS is considered. In the beginning of the human flight era both the USSR and the USA used short mission profiles due to limited life support resources. A rendezvous during these missions was usually achieved in 1-5 revolutions. The short-term rendezvous were made possible by the coordinated launch profiles of both rendezvousing spacecraft, which provided specific relative position of the spacecraft or phase angle conditions. After the beginning of regular flights to the orbital stations these requirements became difficult to fulfill. That is why it was decided to transfer to 1- or 2-day rendezvous profile. The long stay of a crew in a limited habitation volume of the Soyuz-TMA spacecraft before docking to the ISS is one of the most strained parts of the flight and naturally cosmonauts wish to dock to the ISS as soon as possible. As a result of previous studies the short four-burn rendezvous mission profile with docking in a few orbits was developed. It is shown that the current capabilities of the Soyuz-FG launch vehicle and the Soyuz-TMA spacecraft are sufficient to provide for that. The first test of the short rendezvous mission during Progress cargo vehicle flight to the ISS is planned for 2012. Possible contingencies pertinent to this profile are described. In particular, in the majority of the emergency cases there is a possibility of an urgent transfer to the present 2-day rendezvous profile. Thus, the short mission will be very flexible and will not influence the ISS mission plan. Fuel consumption for the nominal and emergency cases is defined by statistical simulation of the rendezvous mission. The qualitative analysis of the short-term and current 2-day rendezvous missions is performed.

  9. A Two-Impulse Plan for Performing Rendezvous on a Once-A-Day Basis

    Science.gov (United States)

    Bird, John D.; Thomas, David F., Jr.

    1960-01-01

    An investigation of a two-impulse plan for performing rendezvous on a once-a-day basis with a near-earth satellite station indicates that launch into rendezvous from slightly less than maximum satellite latitude is an unusually favorable circumstance in that no appreciable expense in mass ratio is incurred. In addition, it was found for the two-impulse maneuver employed in this study that the optimum angular travel of the ferry vehicle to rendezvous was considerably less than the 1800 transfer which is optimum for the two-impulse in-plane launch.

  10. A Proposed Strategy for the U.S. to Develop and Maintain a Mainstream Capability Suite ("Warehouse") for Automated/Autonomous Rendezvous and Docking in Low Earth Orbit and Beyond

    Science.gov (United States)

    Krishnakumar, Kalmanje S.; Stillwater, Ryan A.; Babula, Maria; Moreau, Michael C.; Riedel, J. Ed; Mrozinski, Richard B.; Bradley, Arthur; Bryan, Thomas C.

    2012-01-01

    The ability of space assets to rendezvous and dock/capture/berth is a fundamental enabler for numerous classes of NASA fs missions, and is therefore an essential capability for the future of NASA. Mission classes include: ISS crew rotation, crewed exploration beyond low-Earth-orbit (LEO), on-orbit assembly, ISS cargo supply, crewed satellite servicing, robotic satellite servicing / debris mitigation, robotic sample return, and robotic small body (e.g. near-Earth object, NEO) proximity operations. For a variety of reasons to be described, NASA programs requiring Automated/Autonomous Rendezvous and Docking/Capture/Berthing (AR&D) capabilities are currently spending an order-of-magnitude more than necessary and taking twice as long as necessary to achieve their AR&D capability, "reinventing the wheel" for each program, and have fallen behind all of our foreign counterparts in AR&D technology (especially autonomy) in the process. To ensure future missions' reliability and crew safety (when applicable), to achieve the noted cost and schedule savings by eliminate costs of continually "reinventing the wheel ", the NASA AR&D Community of Practice (CoP) recommends NASA develop an AR&D Warehouse, detailed herein, which does not exist today. The term "warehouse" is used herein to refer to a toolbox or capability suite that has pre-integrated selectable supply-chain hardware and reusable software components that are considered ready-to-fly, low-risk, reliable, versatile, scalable, cost-effective, architecture and destination independent, that can be confidently utilized operationally on human spaceflight and robotic vehicles over a variety of mission classes and design reference missions, especially beyond LEO. The CoP also believes that it is imperative that NASA coordinate and integrate all current and proposed technology development activities into a cohesive cross-Agency strategy to produce and utilize this AR&D warehouse. An initial estimate indicates that if NASA

  11. A Ground Testbed to Advance US Capability in Autonomous Rendezvous and Docking Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The entire Agency supports development of a Commodity for Autonomous Rendezvous and Docking (CARD) as outlined in the Agency-wide Community of Practice whitepaper...

  12. Guidance Algorithms for Non-Drifting Trajectory Generation and Control in RendezVous Missions into Elliptical Orbits

    Science.gov (United States)

    DiSotto, Emanuele; Bastante, Juan Carlos; Drai, Remi

    2007-01-01

    Safety requirement represents one of the most critical aspect when defining the operational profile for a RendezVous mission. This requirement specially affects the design of the guidance algorithms that need to be tailored to guarantee what is normally referred to as Passive Trajectory Protection . The basic idea of passive trajectory protection is to design all the trajectory elements in an approach sequence such that if, at any point of the trajectory, thrust control ceases, the resulting free drift motion will remain collision free during a certain amount of time. This paper deals with the design and performances assessment of specific guidance algorithm addressing this issue. Firstly the problem is addressed for circular orbit using the Traveling Ellipse formulation for the relative motion. Secondly a solution for the RendezVous into a generic elliptical orbit is presented. This is based on a reduced transition matrix obtained through a description of the relative motion based on the first order variation of the orbital elements.

  13. NEP for a Kuiper Belt Object Rendezvous Mission

    Energy Technology Data Exchange (ETDEWEB)

    HOUTS,MICHAEL G.; LENARD,ROGER X.; LIPINSKI,RONALD J.; PATTON,BRUCE; POSTON,DAVID I.; WRIGHT,STEVEN A.

    1999-11-03

    Kuiper Belt Objects (KBOs) are a recently-discovered set of solar system bodies which lie at about the orbit of Pluto (40 AU) out to about 100 astronomical units (AU). There are estimated to be about 100,000 KBOS with a diameter greater than 100 km. KBOS are postulated to be composed of the pristine material which formed our solar system and may even have organic materials in them. A detailed study of KBO size, orbit distribution, structure, and surface composition could shed light on the origins of the solar system and perhaps even on the origin of life in our solar system. A rendezvous mission including a lander would be needed to perform chemical analysis of the surface and sub-surface composition of KBOS. These requirements set the size of the science probe at around a ton. Mission analyses show that a fission-powered system with an electric thruster could rendezvous at 40 AU in about 13.0 years with a total {Delta}V of 46 krnk. It would deliver a 1000-kg science payload while providing ample onboard power for relaying data back to earth. The launch mass of the entire system (power, thrusters, propellant, navigation, communication, structure, science payload, etc.) would be 7984 kg if it were placed into an earth-escape trajectory (C=O). Alternatively, the system could be placed into a 700-km earth orbit with more propellant,yielding a total mass in LEO of 8618 kg, and then spiral out of earth orbit to arrive at the KBO in 14.3 years. To achieve this performance, a fission power system with 100 kW of electrical power and a total mass (reactor, shield, conversion, and radiator) of about 2350 kg. Three possible configurations are proposed: (1) a UZrH-fueled, NaK-cooled reactor with a steam Rankine conversion system, (2) a UN-fueled gas-cooled reactor with a recuperated Brayton conversion system, and (3) a UN-fueled heatpipe-cooled reactor with a recuperated Brayton conversion system. (Boiling and condensation in the Rankine system is a technical risk at present

  14. Pollinators' mating rendezvous and the evolution of floral advertisement.

    Science.gov (United States)

    Fishman, Michael A; Hadany, Lilach

    2013-01-07

    Successful cross-fertilization in plant species that rely on animal pollinators depends not just on the number of pollinator visits, but also on these visits' duration. Furthermore, in non-deceptive pollination, a visit's duration depends on the magnitude of the reward provided to the pollinator. Accordingly, plants that rely on biotic pollination have to partition their investment in cross-fertilization assurance between attracting pollinator visits - advertisement, and rewarding visitors to assure that the visit is of productive duration. Here we analyze these processes by a combination of optimality methods and game theoretical modeling. Our results indicate that the optimality in such allocation of resources depends on the types of reward offered to the pollinators. More precisely, we show that plants that offer both food reward and mating rendezvous to pollinators will evolve to allocate a higher proportion of their cross-fertilization assurance budget to advertisement than plants that offer only food reward. That is, our results indicate that pollinators' mating habits may play a role in floral evolution.

  15. Asteroid Rendezvous Mission Design Using Multiobjective Particle Swarm Optimization

    Directory of Open Access Journals (Sweden)

    Ya-zhong Luo

    2014-01-01

    Full Text Available A new preliminary trajectory design method for asteroid rendezvous mission using multiobjective optimization techniques is proposed. This method can overcome the disadvantages of the widely employed Pork-Chop method. The multiobjective integrated launch window and multi-impulse transfer trajectory design model is formulated, which employes minimum-fuel cost and minimum-time transfer as two objective functions. The multiobjective particle swarm optimization (MOPSO is employed to locate the Pareto solution. The optimization results of two different asteroid mission designs show that the proposed approach can effectively and efficiently demonstrate the relations among the mission characteristic parameters such as launch time, transfer time, propellant cost, and number of maneuvers, which will provide very useful reference for practical asteroid mission design. Compared with the PCP method, the proposed approach is demonstrated to be able to provide much more easily used results, obtain better propellant-optimal solutions, and have much better efficiency. The MOPSO shows a very competitive performance with respect to the NSGA-II and the SPEA-II; besides a proposed boundary constraint optimization strategy is testified to be able to improve its performance.

  16. Multi-sensor Testing for Automated Rendezvous and Docking

    Science.gov (United States)

    Howard, Richard T.; Carrington, Connie K.

    2008-01-01

    During the past two years, many sensors have been tested in an open-loop fashion in the Marshall Space Flight Center (MSFC) Flight Robotics Laboratory (FRL) to both determine their suitability for use in Automated Rendezvous and Docking (AR&D) systems and to ensure the test facility is prepared for future multi-sensor testing. The primary focus of this work was in support of the CEV AR&D system, because the AR&D sensor technology area was identified as one of the top risks in the program. In 2006, four different sensors were tested individually or in a pair in the MSFC FRL. In 2007, four sensors, two each of two different types, were tested simultaneously. In each set of tests, the target was moved through a series of pre-planned trajectories while the sensor tracked it. In addition, a laser tracker "truth" sensor also measured the target motion. The tests demonstrated the functionality of testing four sensors simultaneously as well as the capabilities (both good and bad) of all of the different sensors tested. This paper outlines the test setup and conditions, briefly describes the facility, summarizes the earlier results of the individual sensor tests, and describes in some detail the results of the four-sensor testing. Post-test analysis includes data fusion by minimum variance estimation and sequential Kalman filtering. This Sensor Technology Project work was funded by NASA's Exploration Technology Development Program.

  17. Inverse simulation system for manual-controlled rendezvous and docking based on artificial neural network

    Science.gov (United States)

    Zhou, Wanmeng; Wang, Hua; Tang, Guojin; Guo, Shuai

    2016-09-01

    The time-consuming experimental method for handling qualities assessment cannot meet the increasing fast design requirements for the manned space flight. As a tool for the aircraft handling qualities research, the model-predictive-control structured inverse simulation (MPC-IS) has potential applications in the aerospace field to guide the astronauts' operations and evaluate the handling qualities more effectively. Therefore, this paper establishes MPC-IS for the manual-controlled rendezvous and docking (RVD) and proposes a novel artificial neural network inverse simulation system (ANN-IS) to further decrease the computational cost. The novel system was obtained by replacing the inverse model of MPC-IS with the artificial neural network. The optimal neural network was trained by the genetic Levenberg-Marquardt algorithm, and finally determined by the Levenberg-Marquardt algorithm. In order to validate MPC-IS and ANN-IS, the manual-controlled RVD experiments on the simulator were carried out. The comparisons between simulation results and experimental data demonstrated the validity of two systems and the high computational efficiency of ANN-IS.

  18. Ground guided CX-OLEV rendez-vous with uncooperative geostationary satellite

    Science.gov (United States)

    Tarabini, Lorenzo; Gil, Jesús; Gandia, Fernando; Molina, Miguel Ángel; Del Cura, Juan Manuel; Ortega, Guillermo

    2007-06-01

    CX-OLEV is a commercial mission aimed to extend the operational life of geostationary telecommunications satellites by supplying them propulsion, navigation and guidance services. Under SENER's contract and ESA's supervision, GMV designed the CX-OLEV ground guided rendez-vous (RV) approach. The starting point of the RV phase between CX-OLEV and the client is at 35 km distance with an uncertainty of 2 km. Dedicated ground tracking is performed to reduce the position uncertainty to 200 m and therefore to command the closing to 1 km distance. Fly around and final approach maneuvers complete the CX-OLEV RV approach along the client's zenith direction up to a relative distance of 7 m. Two redundant optical cameras working in the 5 m-2 km range are selected as RV sensors. The RV camera images are sent to ground and processed to determine the relative position of the spacecraft. The flight dynamics system calculates, validates and transmits in near real time the RV maneuvers commands. The relative spiral motion of CX-OLEV around the telecommunication satellite is synchronized with the Sun-client-CXOLEV angle to guarantee a good illumination of the client but without shadowing the client satellite's solar panels. The complete RV is simulated in a dedicated environment to assess its feasibility.

  19. Proximal Biceps Tendonitis

    Science.gov (United States)

    ... tendons that attach the top of the biceps muscle to the shoulder are the proximal tendons . There are two proximal ... ll want to do exercises that strengthen the muscles of your shoulder and upper arm. Strong muscles will keep the ...

  20. Observer-Based Robust Control for Spacecraft Rendezvous with Thrust Saturation

    Directory of Open Access Journals (Sweden)

    Neng Wan

    2014-01-01

    Full Text Available This paper proposes an observer-based robust guaranteed cost control method for thrust-limited rendezvous in near-circular orbits. Treating the noncircularity of the target orbit as a parametric uncertainty, a linearized motion model derived from the two-body problem is adopted as the controlled plant. Based on this model, a robust guaranteed cost observer-controller is synthesized with a less conservative saturation control law, and sufficient condition for the existence of this observer-based rendezvous controller is derived. Finally, an illustrative example with immeasurable velocity states is presented to demonstrate the advantages and effectiveness of the control scheme.

  1. Result of Rendezvous Docking Experiment of ETS.35zw .5zw .25mmVII

    Science.gov (United States)

    Kawano, Isao; Mokuno, Masaaki; Suzuki, Takashi; Koyama, Hiroshi; Kunugi, Makoto

    ETS VII is a test satellite to perform in-orbit demonstration of autonomous rendezvous docking (RVD) technology, which will be necessary for advanced space activities in the early 21st century. ETS VII performed three RVD experiment flights, and verified all technical items. ETS VII demonstrated first autonomous RVD between unmanned vehicles, and remote piloted rendezvous flight position accuracy at docking was about 1cm, and acceleration was less than 1.5mG (low impact docking). In the second RVD experiment flight, ETS VII detected attitude anomaly and executed disable abort for safety insurance. We present the results and evaluation of three RVD experiment flights in this paper.

  2. Proximal Probes Facility

    Data.gov (United States)

    Federal Laboratory Consortium — The Proximal Probes Facility consists of laboratories for microscopy, spectroscopy, and probing of nanostructured materials and their functional properties. At the...

  3. Laparoendoscopic Rendezvous for Concomitant Cholecystocholedocholithiasis: A Successful Modality Even in the Most Difficult Presentations Including Pregnancy

    Science.gov (United States)

    Mikwar, Zaher Abdulaziz; Ahmad, Akram Neyaz

    2016-01-01

    Background. Laparoendoscopic rendezvous (LERV) technique is emerging as an attractive treatment option for concomitant cholecystocholedocholithiasis. In this paper, we report our experience in performing the LERV technique in patients with unusual presentations in terms of anatomical difficulty, pregnancy, multiple comorbid diseases, and postlaparotomy. We aim to highlight the effectiveness of the LERV technique in some clinical situations where conventional methods would fail or carry high risks in adequately managing concomitant cholecystocholedocholithiasis. Methods. Four patients diagnosed to have concomitant cholecystocholedocholithiasis with associated difficult presentation or comorbid diseases were treated using the LERV technique. One patient presented with difficult anatomy where ERCP failed at initial attempts. Another patient was pregnant (first trimester). A third patient had complex comorbid diseases (bronchial asthma, hypertension, congestive heart failure, and end-stage renal disease on regular hemodialysis). A fourth patient had previous laparotomy and sigmoidectomy for diverticular disease and had severe hospital phobia. Results. All patients tolerated the LERV technique very well; no intraoperative occurrence was reported. The mean operative time was 86.3 ± 17.2 minutes; mean time of the endoscopic part was 29.4 ± 3.57 minutes. The mean blood loss was 44.3 ± 18.2 mL (range 20–85). Residual stone, postoperative complications, postoperative morbidity, and postoperative mortality were 0 (0%). Postoperative short hospital stay was reported in all patients, average 3 days (range 2–4). Conclusion. LERV procedure is a safe and effective treatment option for the management of concomitant cholecystocholedocholithiasis, even in difficult situations where other methods would fail or carry high risks, or in patients presenting with severe comorbid diseases or pregnancy. This procedure may emerge as an attractive alternative option for high

  4. Laparoendoscopic Rendezvous for Concomitant Cholecystocholedocholithiasis: A Successful Modality Even in the Most Difficult Presentations Including Pregnancy

    Directory of Open Access Journals (Sweden)

    Bader Hamza Shirah

    2016-01-01

    Full Text Available Background. Laparoendoscopic rendezvous (LERV technique is emerging as an attractive treatment option for concomitant cholecystocholedocholithiasis. In this paper, we report our experience in performing the LERV technique in patients with unusual presentations in terms of anatomical difficulty, pregnancy, multiple comorbid diseases, and postlaparotomy. We aim to highlight the effectiveness of the LERV technique in some clinical situations where conventional methods would fail or carry high risks in adequately managing concomitant cholecystocholedocholithiasis. Methods. Four patients diagnosed to have concomitant cholecystocholedocholithiasis with associated difficult presentation or comorbid diseases were treated using the LERV technique. One patient presented with difficult anatomy where ERCP failed at initial attempts. Another patient was pregnant (first trimester. A third patient had complex comorbid diseases (bronchial asthma, hypertension, congestive heart failure, and end-stage renal disease on regular hemodialysis. A fourth patient had previous laparotomy and sigmoidectomy for diverticular disease and had severe hospital phobia. Results. All patients tolerated the LERV technique very well; no intraoperative occurrence was reported. The mean operative time was 86.3±17.2 minutes; mean time of the endoscopic part was 29.4±3.57 minutes. The mean blood loss was 44.3±18.2 mL (range 20–85. Residual stone, postoperative complications, postoperative morbidity, and postoperative mortality were 0 (0%. Postoperative short hospital stay was reported in all patients, average 3 days (range 2–4. Conclusion. LERV procedure is a safe and effective treatment option for the management of concomitant cholecystocholedocholithiasis, even in difficult situations where other methods would fail or carry high risks, or in patients presenting with severe comorbid diseases or pregnancy. This procedure may emerge as an attractive alternative option for high

  5. Risk factors for post-operative periprosthetic fractures following primary total hip arthroplasty with a proximally coated double-tapered cementless femoral component

    DEFF Research Database (Denmark)

    Gromov, K; Bersang, A; Nielsen, C S

    2017-01-01

    periprosthetic fractures (3.0%) were identified during the follow-up and median time until fracture was 16 days, (interquartile range 10 to 31.5). Patients with femoral Dorr type C had a 5.2 times increased risk of post-operative periprosthetic fracture compared with type B, while female patients had a near...... significant two times increased risk over time for post-operative fracture. CONCLUSION: Dorr type C is an independent risk factor for early periprosthetic fracture, following THA using a double tapered cementless stem such as the Bi-Metric. Surgeons should take bone morphology into consideration when planning......AIMS: The aim of this study was to identify patient- and surgery-related risk factors for sustaining an early periprosthetic fracture following primary total hip arthroplasty (THA) performed using a double-tapered cementless femoral component (Bi-Metric femoral stem; Biomet Inc., Warsaw, Indiana...

  6. Endoskopisk ultralydvejledt rendezvous til intern drænage ved galdevejsobstruktion

    DEFF Research Database (Denmark)

    Knudsen, Marie Høxbro; Vilmann, Peter; Hassan, Hazem

    2015-01-01

    Endoscopic retrograde cholangiography (ERCP) is currently standard treatment for biliary drainage. Endoscopic ultrasound guided rendezvous (EUS-RV) is a novel method to overcome an unsuccessful biliary drainage procedure. Under endoscopic ultrasound guidance a guidewire is passed via a needle fro...

  7. SPHERES MOSR Rendezvous and Docking with the OS (RDOS) Project

    Data.gov (United States)

    National Aeronautics and Space Administration — NASA's Mars Sample Return (MSR) mission involves many challenging operations. One of the highest-risk operations is the guidance of the Orbiting Sample (OS) into the...

  8. Optimal starting conditions for the rendezvous maneuver: Analytical and computational approach

    Science.gov (United States)

    Ciarcia, Marco

    The three-dimensional rendezvous between two spacecraft is considered: a target spacecraft on a circular orbit around the Earth and a chaser spacecraft initially on some elliptical orbit yet to be determined. The chaser spacecraft has variable mass, limited thrust, and its trajectory is governed by three controls, one determining the thrust magnitude and two determining the thrust direction. We seek the time history of the controls in such a way that the propellant mass required to execute the rendezvous maneuver is minimized. Two cases are considered: (i) time-to-rendezvous free and (ii) time-to-rendezvous given, respectively equivalent to (i) free angular travel and (ii) fixed angular travel for the target spacecraft. The above problem has been studied by several authors under the assumption that the initial separation coordinates and the initial separation velocities are given, hence known initial conditions for the chaser spacecraft. In this paper, it is assumed that both the initial separation coordinates and initial separation velocities are free except for the requirement that the initial chaser-to-target distance is given so as to prevent the occurrence of trivial solutions. Two approaches are employed: optimal control formulation (Part A) and mathematical programming formulation (Part B). In Part A, analyses are performed with the multiple-subarc sequential gradient-restoration algorithm for optimal control problems. They show that the fuel-optimal trajectory is zero-bang, namely it is characterized by two subarcs: a long coasting zero-thrust subarc followed by a short powered max-thrust braking subarc. While the thrust direction of the powered subarc is continuously variable for the optimal trajectory, its replacement with a constant (yet optimized) thrust direction produces a very efficient guidance trajectory. Indeed, for all values of the initial distance, the fuel required by the guidance trajectory is within less than one percent of the fuel required

  9. Operative treatment of proximal humeral fractures with T incision and MIPPO locking compression plate%T形切口下微创锁定钢板治疗肱骨近端骨折疗效探讨

    Institute of Scientific and Technical Information of China (English)

    韩立强; 江汉; 肖联平; 杨国跃; 江毅; 张殿英

    2014-01-01

    目的:回顾性分析 T 形切口下微创锁定钢板治疗肱骨近端骨折的疗效。方法自2011年1月至2013年8月,我院收治肱骨近端骨折患者35例,分类方法采用 AO 分型,其中11-A2型7例,11-A3型12例,11-B1型8例,11-B2型6例,11-C1型2例,均采用T型切口下锁定钢板手术治疗,术后2~3d开始肩关节被动活动锻炼,逐渐增加活动范围,术后2 周开始肩关节摆动锻炼,术后3周开始肩关节锻炼,并采用 Neer肩关节功能评分。结果本组 3 5例患者手术切口均一期愈合,所有患者均得到随访,随访时间5~16个月,平均13.1个月,骨折均骨性愈合,术后未发现腋神经损害表现,未发现退钉、钢板松动。Neer肩关节功能评分:优19例,良10例,可6例。结论 T 形切口下微创锁定钢板治疗肱骨近端骨折具有创伤小、功能恢复快、临床疗效佳的优点,尤其适于 AO 分型的A2、A3型和B型骨折的治疗。%Background With the aging of population,the proximal humerus fractures are becoming more and more common.The displaced proximal humeral fractures often result in long-term disability.For the instability and displacement of the fracture,the operation treatment is of the best effect so far.At present,the locking plate has been widely used in the treatment of proximal humerus fractures,and has already achieved good clinical results.This paper retrospectively analysis the functional effect of minimally invasive locking plate in the treatment of proximal humeral fractures in our hospital with T shape incision.Methods Thirty-five cases in our hospital suffered from proximal humeral fractures were included in this study (16 males,19 females,aged 31-72 years old)during the past years.The average age was 56.3 years old.Fifteen cases were injured on the left side,20 cases were injured on the right side.All the fractures were fresh.The cause of injury:20 cases were living accident,6 cases were of high falling inj ury,9 cases were of traffic

  10. Proximal humerus fractures.

    Science.gov (United States)

    Price, Matthew C; Horn, Pamela L; Latshaw, James C

    2013-01-01

    Proximal humerus fractures are among the most common fractures associated with osteoporosis. With an aging population, incidence of these fractures will only increase. The proximal humerus not only forms the lateral portion of the shoulder articulation but also has significant associations with musculoskeletal and neurovascular structures. As a result, fractures of the proximal humerus can significantly impact not only the function of the shoulder joint, but the health and function of the entire upper extremity as well. Understanding of these fractures, the management options, and associated nursing care, can help reduce morbidity rate and improve functional outcomes.

  11. Spheres: from Ground Development to ISS Operations

    Science.gov (United States)

    Katterhagen, A.

    2016-01-01

    SPHERES (Synchronized Position Hold Engage and Reorient Experimental Satellites) is an internal International Space Station (ISS) Facility that supports multiple investigations for the development of multi-spacecraft and robotic control algorithms. The SPHERES National Lab Facility aboard ISS is managed and operated by NASA Ames Research Center (ARC) at Moffett Field California. The SPHERES Facility on ISS consists of three self-contained eight-inch diameter free-floating satellites which perform the various flight algorithms and serve as a platform to support the integration of experimental hardware. SPHERES has served to mature the adaptability of control algorithms of future formation flight missions in microgravity (6 DOF (Degrees of Freedom) / long duration microgravity), demonstrate key close-proximity formation flight and rendezvous and docking maneuvers, understand fault diagnosis and recovery, improve the field of human telerobotic operation and control, and lessons learned on ISS have significant impact on ground robotics, mapping, localization, and sensing in three-dimensions - among several other areas of study.

  12. Proximity sensor system development. CRADA final report

    Energy Technology Data Exchange (ETDEWEB)

    Haley, D.C. [Oak Ridge National Lab., TN (United States); Pigoski, T.M. [Merrit Systems, Inc. (United States)

    1998-01-01

    Lockheed Martin Energy Research Corporation (LMERC) and Merritt Systems, Inc. (MSI) entered into a Cooperative Research and Development Agreement (CRADA) for the development and demonstration of a compact, modular proximity sensing system suitable for application to a wide class of manipulator systems operated in support of environmental restoration and waste management activities. In teleoperated modes, proximity sensing provides the manipulator operator continuous information regarding the proximity of the manipulator to objects in the workspace. In teleoperated and robotic modes, proximity sensing provides added safety through the implementation of active whole arm collision avoidance capabilities. Oak Ridge National Laboratory (ORNL), managed by LMERC for the United States Department of Energy (DOE), has developed an application specific integrated circuit (ASIC) design for the electronics required to support a modular whole arm proximity sensing system based on the use of capacitive sensors developed at Sandia National Laboratories. The use of ASIC technology greatly reduces the size of the electronics required to support the selected sensor types allowing deployment of many small sensor nodes over a large area of the manipulator surface to provide maximum sensor coverage. The ASIC design also provides a communication interface to support sensor commands from and sensor data transmission to a distributed processing system which allows modular implementation and operation of the sensor system. MSI is a commercial small business specializing in proximity sensing systems based upon infrared and acoustic sensors.

  13. Coal - proximate analysis

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-06-14

    This Standard establishes a practice for the proximate analysis of coal, that is, the coal is analysed for the content of moisture, ash and volatile matter; fixed carbon is calculated. The standard provides a basis for the comparison of coals.

  14. Proximal Focal Femoral Deficiency

    OpenAIRE

    Vishal Kalia, Vibhuti

    2008-01-01

    Proximal focal femoral deficiency (PFFD) is a developmental disorder of the proximal segment of thefemur and of acetabulum resulting in shortening of the affected limb and impairment of the function. It isa spectrum of congenital osseous anomalies characterized by a deficiency in the structure of the proximalfemur. The diagnosis is often made by radiological evaluation which includes identification and descriptionof PFFD and evaluation of associated limb anomalies by plain radiographs. Contra...

  15. Systematic Low-Thrust Trajectory Optimization for a Multi-Rendezvous Mission using Adjoint Scaling

    CERN Document Server

    Jiang, Fanghua

    2016-01-01

    A deep-space exploration mission with low-thrust propulsion to rendezvous with multiple asteroids is investigated. Indirect methods, based on the optimal control theory, are implemented to optimize the fuel consumption. The application of indirect methods for optimizing low-thrust trajectories between two asteroids is briefly given. An effective method is proposed to provide initial guesses for transfers between close near-circular near-coplanar orbits. The conditions for optimality of a multi-asteroid rendezvous mission are determined. The intuitive method of splitting the trajectories into several legs that are solved sequentially is applied first. Then the results are patched together by a scaling method to provide a tentative guess for optimizing the whole trajectory. Numerical examples of optimizing three probe exploration sequences that contain a dozen asteroids each demonstrate the validity and efficiency of these methods.

  16. The classical Doppler effect as a rendezvous problem; 3D case

    OpenAIRE

    Di Rocco, Hector Omar

    2016-01-01

    En este trabajo se deriva la fórmula para el corrimiento Doppler como si tratásemos un problema de encuentro, unificando todos los posibles movimientos relativos entre la fuente y el observador We derive the classical Doppler shift formula as a rendezvous problem, unifying all possible relative movements between the source and the observer Fil: Di Rocco, Hector Omar. Universidad Nacional del Centro de la Provincia de Buenos Aires. Facultad de Ciencias Exactas. Instituto de Fisica Arroyo...

  17. Neighborhoods and manageable proximity

    Directory of Open Access Journals (Sweden)

    Stavros Stavrides

    2011-08-01

    Full Text Available The theatricality of urban encounters is above all a theatricality of distances which allow for the encounter. The absolute “strangeness” of the crowd (Simmel 1997: 74 expressed, in its purest form, in the absolute proximity of a crowded subway train, does not generally allow for any movements of approach, but only for nervous hostile reactions and submissive hypnotic gestures. Neither forced intersections in the course of pedestrians or vehicles, nor the instantaneous crossing of distances by the technology of live broadcasting and remote control give birth to places of encounter. In the forced proximity of the metropolitan crowd which haunted the city of the 19th and 20th century, as well as in the forced proximity of the tele-presence which haunts the dystopic prospect of the future “omnipolis” (Virilio 1997: 74, the necessary distance, which is the stage of an encounter between different instances of otherness, is dissipated.

  18. Cooperative Solution of Multi-UAV Rendezvous Problem with Network Restrictions

    Directory of Open Access Journals (Sweden)

    Qingjie Zhang

    2015-01-01

    Full Text Available By considering the complex networks, the cooperative game based optimal consensus (CGOC algorithm is proposed to solve the multi-UAV rendezvous problem in the mission area. Firstly, the mathematical description of the rendezvous problem is established, and the solving framework is provided based on the coordination variables and coordination function. It can decrease the transmission of the redundant information and reduce the influence of the limited network on the task. Secondly, the CGOC algorithm is presented for the UAVs in distributed cooperative manner, which can minimize the overall cost of the multi-UAV system. The CGOC control problem and the corresponding solving protocol are given by using the cooperative game theory and sensitivity parameter method. Then, the CGOC method of multi-UAV rendezvous problem is proposed, which focuses on the trajectory control of the platform rather than the path planning. Simulation results are given to demonstrate the effectiveness of the proposed CGOC method under complex network conditions and the benefit on the overall optimality and dynamic response.

  19. Imaging Flash Lidar for Safe Landing on Solar System Bodies and Spacecraft Rendezvous and Docking

    Science.gov (United States)

    Amzajerdian, Farzin; Roback, Vincent E.; Bulyshev, Alexander E.; Brewster, Paul F.; Carrion, William A; Pierrottet, Diego F.; Hines, Glenn D.; Petway, Larry B.; Barnes, Bruce W.; Noe, Anna M.

    2015-01-01

    NASA has been pursuing flash lidar technology for autonomous, safe landing on solar system bodies and for automated rendezvous and docking. During the final stages of the landing from about 1 kilometer to 500 meters above the ground, the flash lidar can generate 3-Dimensional images of the terrain to identify hazardous features such as craters, rocks, and steep slopes. The onboard flight computer can then use the 3-D map of terrain to guide the vehicle to a safe location. As an automated rendezvous and docking sensor, the flash lidar can provide relative range, velocity, and bearing from an approaching spacecraft to another spacecraft or a space station. NASA Langley Research Center has developed and demonstrated a flash lidar sensor system capable of generating 16,000 pixels range images with 7 centimeters precision, at 20 Hertz frame rate, from a maximum slant range of 1800 m from the target area. This paper describes the lidar instrument and presents the results of recent flight tests onboard a rocket-propelled free-flyer vehicle (Morpheus) built by NASA Johnson Space Center. The flights were conducted at a simulated lunar terrain site, consisting of realistic hazard features and designated landing areas, built at NASA Kennedy Space Center specifically for this demonstration test. This paper also provides an overview of the plan for continued advancement of the flash lidar technology aimed at enhancing its performance to meet both landing and automated rendezvous and docking applications.

  20. Atrofia muscular proximal familiar

    Directory of Open Access Journals (Sweden)

    José Antonio Levy

    1962-09-01

    Full Text Available Os autores relatam dois casos de atrofia muscular proximal familiar, moléstia caracterizada por déficit motor e atrofias musculares de distribuição proximal, secundárias a lesão de neurônios periféricos. Assim, como em outros casos descritos na literatura, foi feito inicialmente o diagnóstico de distrofia muscular progressiva. O diagnóstico correto foi conseguido com auxílio da eletromiografia e da biopsia muscular.

  1. Proximity and IPO Underpricing

    DEFF Research Database (Denmark)

    Nielsson, Ulf; Wójcik, Dariusz

    2016-01-01

    This paper analyses the relationship between issuers' location and IPO underpricing in the U.S. from 1986 to 2014. Issuers headquartered in rural areas are associated with lower underpricing compared to urban firms. This finding is consistent with strong local bias in rural areas accompanied...... by superior local information, which associates with more accurate pricing and less money left on the table. The paper further finds that refined measures of local bias, such as proximity to finance professionals and density of financial expertise, correlate more with IPO underpricing than proximity to large...

  2. Steerable Capacitive Proximity Sensor

    Science.gov (United States)

    Jenstrom, Del T.; Mcconnell, Robert L.

    1994-01-01

    Steerable capacitive proximity sensor of "capaciflector" type based partly on sensing units described in GSC-13377 and GSC-13475. Position of maximum sensitivity adjusted without moving sensor. Voltage of each driven shield adjusted separately to concentrate sensing electric field more toward one side or other.

  3. Children's proximal societal conditions

    DEFF Research Database (Denmark)

    Stanek, Anja Hvidtfeldt

    2018-01-01

    This article will argue for and unfold the conceptualization of children’s proximal societal conditions. Through out different research project in which children’s everyday life in different day care settings and in schools has been studied, it becomes clear that ‘the societal’ is not something t...

  4. Proximate Analysis of Coal

    Science.gov (United States)

    Donahue, Craig J.; Rais, Elizabeth A.

    2009-01-01

    This lab experiment illustrates the use of thermogravimetric analysis (TGA) to perform proximate analysis on a series of coal samples of different rank. Peat and coke are also examined. A total of four exercises are described. These are dry exercises as students interpret previously recorded scans. The weight percent moisture, volatile matter,…

  5. "X"成形术及术后手部近侧指间关节屈曲挛缩畸形的康复治疗%" X" plastic operation and postoperative rehabilitative treatment of hand proximal interphalangeal joint flexion contraction deformity

    Institute of Scientific and Technical Information of China (English)

    杨国华; 安宇; 马勇胜; 贾断峰; 邹中芳

    2002-01-01

    Background:The contraction deformity of hand proximal interphalangeal joint flexion often occurs after different injury of palmar digital skin,which has effections on hand functions in different extent(varying degrees) and brings many difficults to patients in their life and work.And marked effect are achieved when " X" plastic operation and postoperative recovery therapy are put into use.

  6. Proximity Networks and Epidemics

    CERN Document Server

    Toroczkai, Z

    2007-01-01

    Disease spread in most biological populations requires the proximity of agents. In populations where the individuals have spatial mobility, the contact graph is generated by the "collision dynamics" of the agents, and thus the evolution of epidemics couples directly to the spatial dynamics of the population. We first briefly review the properties and the methodology of an agent-based simulation (EPISIMS) to model disease spread in realistic urban dynamic contact networks. Using the data generated by this simulation, we introduce the notion of dynamic proximity networks which takes into account the relevant time scales for disease spread: contact duration, infectivity period and rate of contact creation. This approach promises to be a good candidate for a unified treatment of epidemic types that are driven by agent collision dynamics. In particular, using a simple model, we show that it can can account for the observed qualitative differences between the degree distributions of contact graphs of diseases with ...

  7. Proximate analysis of coal

    Energy Technology Data Exchange (ETDEWEB)

    Donahue, C.J.; Rais, E.A. [University of Michigan, Dearborn, MI (USA)

    2009-02-15

    This lab experiment illustrates the use of thermogravimetric analysis (TGA) to perform proximate analysis on a series of coal samples of different rank. Peat and coke are also examined. A total of four exercises are described. These are dry exercises as students interpret previously recorded scans. The weight percent moisture, volatile matter, fixed carbon, and ash content are determined for each sample and comparisons are made. Proximate analysis is performed on a coal sample from a local electric utility. From the weight percent sulfur found in the coal (determined by a separate procedure the Eschka method) and the ash content, students calculate the quantity of sulfur dioxide emissions and ash produced annually by a large coal-fired electric power plant.

  8. Proximal femoral fractures

    DEFF Research Database (Denmark)

    Palm, Henrik; Teixidor, Jordi

    2015-01-01

    BACKGROUND: In hip fracture surgery, the exact choice of implant often remains somewhat unclear for the individual surgeon, but the growing literature consensus has enabled publication of evidence-based surgical treatment pathways. The aim of this article was to review author pathways and national...... guidelines for hip fracture surgery and discuss a method for future pathway/guideline implementation and evaluation. METHODS: By a PubMed search in March 2015 six studies of surgical treatment pathways covering all types of proximal femoral fractures with publication after 1995 were identified. Also we...... searched the homepages of the national heath authorities and national orthopedic societies in West Europe and found 11 national or regional (in case of no national) guidelines including any type of proximal femoral fracture surgery. RESULTS: Pathway consensus is outspread (internal fixation for un...

  9. Proximal Focal Femoral Deficiency

    Directory of Open Access Journals (Sweden)

    Vishal Kalia, Vibhuti

    2008-01-01

    Full Text Available Proximal focal femoral deficiency (PFFD is a developmental disorder of the proximal segment of thefemur and of acetabulum resulting in shortening of the affected limb and impairment of the function. It isa spectrum of congenital osseous anomalies characterized by a deficiency in the structure of the proximalfemur. The diagnosis is often made by radiological evaluation which includes identification and descriptionof PFFD and evaluation of associated limb anomalies by plain radiographs. Contrast arthrography orMagnetic Resonance Imaging is indicated when radiological features are questionable and to disclose thepresence and location of the femoral head and any cartilagenous anlage. The disorder is more commonlyunilateral and is apparent at birth. However, bilateral involvement is rarely seen. Therapy of the disorder isdirected towards satisfactory ambulation and specific treatment depending on the severity of dysplasia.

  10. Proximate analysis by automated thermogravimetry

    Energy Technology Data Exchange (ETDEWEB)

    Elder, J.P.

    1983-05-01

    A study has been made of the use of the Perkin-Elmer thermogravimetric instrument TGS-2, under the control of the System 4 microprocessor for the automatic proximate analysis of solid fossil fuels and related matter. The programs developed are simple to operate, and do not require detailed temperature calibration of the instrumental system. They have been tested with coals of varying rank, biomass samples and Devonian oil shales all of which were of special importance to the State of Kentucky. Precise, accurate data conforming to ASTM specifications were obtained. The simplicity of the technique suggests that it may complement the classical ASTM method and could be used when this latter procedure cannot be employed. However, its adoption as a standardized method must await the development of statistical data resulting from interlaboratory testing on a variety of fossil fuels. (9 refs.)

  11. Proximity effect correction sensitivity analysis

    Science.gov (United States)

    Zepka, Alex; Zimmermann, Rainer; Hoppe, Wolfgang; Schulz, Martin

    2010-05-01

    Determining the quality of a proximity effect correction (PEC) is often done via 1-dimensional measurements such as: CD deviations from target, corner rounding, or line-end shortening. An alternative approach would compare the entire perimeter of the exposed shape and its original design. Unfortunately, this is not a viable solution as there is a practical limit to the number of metrology measurements that can be done in a reasonable amount of time. In this paper we make use of simulated results and introduce a method which may be considered complementary to the standard way of PEC qualification. It compares simulated contours with the target layout via a Boolean XOR operation with the area of the XOR differences providing a direct measure of how close a corrected layout approximates the target.

  12. Robot mapping with proximity detectors

    Science.gov (United States)

    Malik, Raashid; Prasad, Samuel

    1993-05-01

    Robots operating in unknown environments need to acquire knowledge about the environment to facilitate navigation and other tasks. Control procedures that enable a robot to acquire environment knowledge are referred to as mapping our terrain-acquisition procedures. All motion control procedures are influenced by the underlying models. In this area the significant models are: the robot model, the sensor model and the environment model. In this paper we present a mapping algorithm that uses a sensor model based on a proximity detector. The sensor is capable of detecting the presence or absence of objects within an annular ring of radius R to R + (Delta) , surrounding the robot. The sensor provides no exact range information but does indicate that angular region of contact with an obstacle. The robot is modelled as a disc of radius r (r

  13. Embedded Relative Navigation Sensor Fusion Algorithms for Autonomous Rendezvous and Docking Missions

    Science.gov (United States)

    DeKock, Brandon K.; Betts, Kevin M.; McDuffie, James H.; Dreas, Christine B.

    2008-01-01

    bd Systems (a subsidiary of SAIC) has developed a suite of embedded relative navigation sensor fusion algorithms to enable NASA autonomous rendezvous and docking (AR&D) missions. Translational and rotational Extended Kalman Filters (EKFs) were developed for integrating measurements based on the vehicles' orbital mechanics and high-fidelity sensor error models and provide a solution with increased accuracy and robustness relative to any single relative navigation sensor. The filters were tested tinough stand-alone covariance analysis, closed-loop testing with a high-fidelity multi-body orbital simulation, and hardware-in-the-loop (HWIL) testing in the Marshall Space Flight Center (MSFC) Flight Robotics Laboratory (FRL).

  14. Application of neural networks to autonomous rendezvous and docking of space vehicles

    Science.gov (United States)

    Dabney, Richard W.

    1992-01-01

    NASA-Marshall has investigated the feasibility of numerous autonomous rendezvous and docking (ARD) candidate techniques. Neural networks have been studied as a viable basis for such systems' implementation, due to their intrinsic representation of such nonlinear functions as those for which analytical solutions are either difficult or nonexistent. Neural networks are also able to recognize and adapt to changes in their dynamic environment, thereby enhancing redundancy and fault tolerance. Outstanding performance has been obtained from ARD azimuth, elevation, and roll networks of this type.

  15. Proximal Tibiofibular Joint: An overview

    Directory of Open Access Journals (Sweden)

    Tze Wang Chan

    2016-06-01

    Full Text Available Proximal tibiofibular joint is a frequently neglected joint which can be a source of lateral knee pain. Open surgery is the current mainstay of surgical management of proximal tibiofibular joint disorders. The proximal tibiofibular arthroscopy allows access to the joint and adjacent important ligamentous structures. This forms the basis of further development of arthroscopic procedures for a variety of pathologies.

  16. Industrial Computed Tomography using Proximal Algorithm

    KAUST Repository

    Zang, Guangming

    2016-04-14

    In this thesis, we present ProxiSART, a flexible proximal framework for robust 3D cone beam tomographic reconstruction based on the Simultaneous Algebraic Reconstruction Technique (SART). We derive the proximal operator for the SART algorithm and use it for minimizing the data term in a proximal algorithm. We show the flexibility of the framework by plugging in different powerful regularizers, and show its robustness in achieving better reconstruction results in the presence of noise and using fewer projections. We compare our framework to state-of-the-art methods and existing popular software tomography reconstruction packages, on both synthetic and real datasets, and show superior reconstruction quality, especially from noisy data and a small number of projections.

  17. Inexact proximal Newton methods for self-concordant functions

    DEFF Research Database (Denmark)

    Li, Jinchao; Andersen, Martin Skovgaard; Vandenberghe, Lieven

    2016-01-01

    with an application to L1-regularized covariance selection, in which prior constraints on the sparsity pattern of the inverse covariance matrix are imposed. In the numerical experiments the proximal Newton steps are computed by an accelerated proximal gradient method, and multifrontal algorithms for positive definite......We analyze the proximal Newton method for minimizing a sum of a self-concordant function and a convex function with an inexpensive proximal operator. We present new results on the global and local convergence of the method when inexact search directions are used. The method is illustrated...

  18. Study on Performance of Integration Control by Man and Machine in Stage of Final Approaching for Spaceship Rendezvous and Docking

    Science.gov (United States)

    Zhou, Qianxiang; Liu, Zhongqi

    With the development of manned space technology, space rendezvous and docking (RVD) technology will play a more and more important role. The astronauts’ participation in a final close period of man-machine combination control is an important way of RVD technology. Spacecraft RVD control involves control problem of a total of 12 degrees of freedom (location) and attitude which it relative to the inertial space the orbit. Therefore, in order to reduce the astronauts’ operation load and reduce the security requirements to the ground station and achieve an optimal performance of the whole man-machine system, it is need to study how to design the number of control parameters of astronaut or aircraft automatic control system. In this study, with the laboratory conditions on the ground, a method was put forward to develop an experimental system in which the performance evaluation of spaceship RVD integration control by man and machine could be completed. After the RVD precision requirements were determined, 26 male volunteers aged 20-40 took part in the performance evaluation experiments. The RVD integration control success rates and total thruster ignition time were chosen as evaluation indices. Results show that if less than three RVD parameters control tasks were finished by subject and the rest of parameters control task completed by automation, the RVD success rate would be larger than eighty-eight percent and the fuel consumption would be optimized. In addition, there were two subjects who finished the whole six RVD parameters control tasks by enough train. In conclusion, if the astronauts' role should be integrated into the RVD control, it was suitable for them to finish the heading, pitch and roll control in order to assure the man-machine system high performance. If astronauts were needed to finish all parameter control, two points should be taken into consideration, one was enough fuel and another was enough long operation time.

  19. 腓肠肌内侧头肌瓣在胫骨近端骨肉瘤保肢术中的应用%Medial head gastrocnemius muscle flap in the limb-salvage operation for proximal tibial osteosarcoma

    Institute of Scientific and Technical Information of China (English)

    刘傥; 张庆; 张湘生; 黎志宏; 沈奕; 郭晓柠; 凌林

    2012-01-01

    Objective: To evaluate the efficacy of transposition of the medial gastrocnemius muscle flap in the limb-salvage operation for proximal tibial osteosarcoma. Methods: From January 2000 to January 2010, 65 patients [37 males, 28 females; (17.O±6.5) years] suffering from the proximal tibial osteosarcoma had a limb-salvage operation. According to the Enneking staging system, 35 patients were in stage II a, 30 in stage II b. All of the patients underwent resection of the osteosarcomas and reconstruction of the bone defect by prothesis. Among them, there were 35 patients underwent the medial head of the gastrocnemius muscle flap transposition to reconstruct the soft tissues and the other 30 didn't. Results: All the patients were followed-up. In the group with the transposition of medial gastrocnemius muscle flap, the length of tumor bone resection was (13.5±4.2) cm, operation time was (15O±45) min, intraoperative blood loss was (700±135) mL, and drainage volume was (500±200) mL. In the group without the transposition of medial gastrocnemius muscle flap, the length of tumor bone resection was (12.3±5.8) cm, operation time was (13S±37) min, intraoperative blood loss was (6001105) mL, and drainage volume was (450±250) mL. There was significant difference in the operation time (P0.05). In the group with the transposition of medial gastrocnemius muscle flap, local skin necrosis occurred in 2 patients (5.7%), and prosthesis deep infection occurred in 1 (2.9%). In the group without the transposition of medial gastrocnemius muscle flap, subctaneous hematocele, and effusion occurred in 3 (10.0%), wound infection occurred in 4 (13.3%), 1 cured and the other 3 developed prosthesis deep infectioalhere was significant difference in the rate of local complications (P<0.05). According to the function assessment by the Enneking system, in the group with the transposition of medial gastrocnemius muscle flap, 13 patients had excellent results, 17 had good results, 3 had fair

  20. Proximate Composition Analysis.

    Science.gov (United States)

    2016-01-01

    The proximate composition of foods includes moisture, ash, lipid, protein and carbohydrate contents. These food components may be of interest in the food industry for product development, quality control (QC) or regulatory purposes. Analyses used may be rapid methods for QC or more accurate but time-consuming official methods. Sample collection and preparation must be considered carefully to ensure analysis of a homogeneous and representative sample, and to obtain accurate results. Estimation methods of moisture content, ash value, crude lipid, total carbohydrates, starch, total free amino acids and total proteins are put together in a lucid manner.

  1. An integrated autonomous rendezvous and docking system architecture using Centaur modern avionics

    Science.gov (United States)

    Nelson, Kurt

    1991-01-01

    The avionics system for the Centaur upper stage is in the process of being modernized with the current state-of-the-art in strapdown inertial guidance equipment. This equipment includes an integrated flight control processor with a ring laser gyro based inertial guidance system. This inertial navigation unit (INU) uses two MIL-STD-1750A processors and communicates over the MIL-STD-1553B data bus. Commands are translated into load activation through a Remote Control Unit (RCU) which incorporates the use of solid state relays. Also, a programmable data acquisition system replaces separate multiplexer and signal conditioning units. This modern avionics suite is currently being enhanced through independent research and development programs to provide autonomous rendezvous and docking capability using advanced cruise missile image processing technology and integrated GPS navigational aids. A system concept was developed to combine these technologies in order to achieve a fully autonomous rendezvous, docking, and autoland capability. The current system architecture and the evolution of this architecture using advanced modular avionics concepts being pursued for the National Launch System are discussed.

  2. Four-Impulsive Rendezvous Maneuvers for Spacecrafts in Circular Orbits Using Genetic Algorithms

    Directory of Open Access Journals (Sweden)

    Denilson Paulo Souza dos Santos

    2012-01-01

    Full Text Available Spacecraft maneuvers is a very important topic in aerospace engineering activities today. In a more generic way, a spacecraft maneuver has the objective of transferring a spacecraft from one orbit to another, taking into account some restrictions. In the present paper, the problem of rendezvous is considered. In this type of problem, it is necessary to transfer a spacecraft from one orbit to another, but with the extra constraint of meeting another spacecraft when reaching the final orbit. In particular, the present paper aims to analyze rendezvous maneuvers between two coplanar circular orbits, seeking to perform this transfer with lowest possible fuel consumption, assuming that this problem is time-free and using four burns during the process. The assumption of four burns is used to represent a constraint posed by a real mission. Then, a genetic algorithm is used to solve the problem. After that, a study is made for a maneuver that will make a spacecraft to encounter a planet, in order to make a close approach that will change its energy. Several simulations are presented.

  3. Design and development of guidance navigation and control algorithms for spacecraft rendezvous and docking experimentation

    Science.gov (United States)

    Guglieri, Giorgio; Maroglio, Franco; Pellegrino, Pasquale; Torre, Liliana

    2014-01-01

    This paper presents the design of the GNC system of a ground test-bed for spacecraft rendezvous and docking experiments. The test-bed is developed within the STEPS project (Systems and Technologies for Space Exploration). The facility consists of a flat floor and two scaled vehicles, one active chaser and one “semi-active” target. Rendezvous and docking maneuvers are performed floating on the plane with pierced plates as lifting systems. The system is designed to work both with inertial and non-inertial reference frame, receiving signals from navigation sensors as: accelerometers, gyroscopes, laser meter, radio finder and video camera, and combining them with a digital filter. A Proportional-Integrative-Derivative control law and Pulse Width Modulators are used to command the cold gas thrusters of the chaser, and to follow an assigned trajectory with its specified velocity profile. The design and development of the guidance, navigation and control system and its architecture-including the software algorithms-are detailed in the paper, presenting a performance analysis based on a simulated environment. A complete description of the integrated subsystems is also presented.

  4. Technology Development of Automated Rendezvous and Docking/Capture Sensors and Docking Mechanism for the Asteroid Redirect Crewed Mission

    Science.gov (United States)

    Hinkel, Heather; Strube, Matthew; Zipay, John J.; Cryan, Scott

    2016-01-01

    This paper will describe the technology development efforts NASA has underway for Automated Rendezvous and Docking/Capture (AR&D/C) sensors and a docking mechanism and the challenges involved. The paper will additionally address how these technologies will be extended to other missions requiring AR&D/C whether robotic or manned. NASA needs AR&D/C sensors for both the robotic and crewed segments of the Asteroid Redirect Mission (ARM). NASA recently conducted a commonality assessment of the concept of operations for the robotic Asteroid Redirect Vehicle (ARV) and the crewed mission segment using the Orion spacecraft. The commonality assessment also considered several future exploration and science missions requiring an AR&D/C capability. Missions considered were asteroid sample return, satellite servicing, and planetary entry, descent, and landing. This assessment determined that a common sensor suite consisting of one or more visible wavelength cameras, a three-dimensional LIDAR along with long-wavelength infrared cameras for robustness and situational awareness could be used on each mission to eliminate the cost of multiple sensor developments and qualifications. By choosing sensor parameters at build-time instead of at design-time and, without having to requalify flight hardware, a specific mission can design overlapping bearing, range, relative attitude, and position measurement availability to suit their mission requirements with minimal non-recurring engineering costs. The resulting common sensor specification provides the union of all performance requirements for each mission and represents an improvement over the current systems used for AR&D/C today. These sensor specifications are tightly coupled to the docking system capabilities and requirements for final docking conditions. The paper will describe NASA's efforts to develop a standard docking system for use across NASA human spaceflight missions to multiple destinations. It will describe the current

  5. Some properties of fuzzy soft proximity spaces.

    Science.gov (United States)

    Demir, İzzettin; Özbakır, Oya Bedre

    2015-01-01

    We study the fuzzy soft proximity spaces in Katsaras's sense. First, we show how a fuzzy soft topology is derived from a fuzzy soft proximity. Also, we define the notion of fuzzy soft δ-neighborhood in the fuzzy soft proximity space which offers an alternative approach to the study of fuzzy soft proximity spaces. Later, we obtain the initial fuzzy soft proximity determined by a family of fuzzy soft proximities. Finally, we investigate relationship between fuzzy soft proximities and proximities.

  6. Some Properties of Fuzzy Soft Proximity Spaces

    Science.gov (United States)

    Demir, İzzettin; Özbakır, Oya Bedre

    2015-01-01

    We study the fuzzy soft proximity spaces in Katsaras's sense. First, we show how a fuzzy soft topology is derived from a fuzzy soft proximity. Also, we define the notion of fuzzy soft δ-neighborhood in the fuzzy soft proximity space which offers an alternative approach to the study of fuzzy soft proximity spaces. Later, we obtain the initial fuzzy soft proximity determined by a family of fuzzy soft proximities. Finally, we investigate relationship between fuzzy soft proximities and proximities. PMID:25793224

  7. Proximal Biceps Tenodesis

    Science.gov (United States)

    Kovack, Thomas J.; Idoine, John D.; Jacob, Paul B.

    2014-01-01

    Purpose: To (1) better define the anatomy of the proximal shoulder in relation to the long head of the biceps tendon, (2) compare the length-tension relationship of the biceps tendon in the native shoulder with that after arthroscopic and open tenodesis techniques using interference screws, and (3) provide surgical recommendations for both procedures based on study findings. Study Design: Descriptive laboratory study. Methods: Twenty fresh-frozen cadaveric shoulders were dissected for analysis. Initial anatomic measurements involving the proximal long head of the biceps tendon (BT) were made, which included: the labral origin to the superior bicipital groove (LO-SBG), the total tendon length (TTL), the musculotendinous junction (MTJ) to the inferior pectoralis major tendon border, the MTJ to the superior pectoralis major tendon border, and the biceps tendon diameter (BTD) at 2 different tenodesis locations. These same measurements were made again after completing a simulated suprapectoral arthroscopic and open subpectoral tenodesis, both with interference screw fixation. Statistical comparisons were then made between the native anatomy and that after tenodesis, with the goal of assessing the accuracy of re-establishing the normal length-tension relationship of the long head of the BT after simulated arthroscopic suprapectoral and open subpectoral tenodesis with tenodesis screws. Results: For all cadavers, the mean TTL was 104.1 mm. For the arthroscopic suprapectoral technique, the mean LO-SBG was 33.6 mm, and the mean tendon resection length was 12.8 mm in males and 5.0 mm in females. The mean BTD was 6.35 mm at the arthroscopic suprapectoral tenodesis site and 5.75 mm at the open subpectoral tenodesis site. Males were found to have statistically longer TTL and LO-SBG measurements (111.6 vs 96.5 mm [P = .027] and 37.2 vs 30.0 mm [P = .009], respectively). In the native shoulder, the mean distances from the MTJ to the superior and inferior borders of the pectoralis

  8. Generalized Proximal ψ-Contraction Mappings and Best Proximity Points

    Directory of Open Access Journals (Sweden)

    Winate Sanhan

    2012-01-01

    Full Text Available We generalized the notion of proximal contractions of the first and the second kinds and established the best proximity point theorems for these classes. Our results improve and extend recent result of Sadiq Basha (2011 and some authors.

  9. Observer-Based Stabilization of Spacecraft Rendezvous with Variable Sampling and Sensor Nonlinearity

    Directory of Open Access Journals (Sweden)

    Zhuoshi Li

    2013-01-01

    Full Text Available This paper addresses the observer-based control problem of spacecraft rendezvous with nonuniform sampling period. The relative dynamic model is based on the classical Clohessy-Wiltshire equation, and sensor nonlinearity and sampling are considered together in a unified framework. The purpose of this paper is to perform an observer-based controller synthesis by using sampled and saturated output measurements, such that the resulting closed-loop system is exponentially stable. A time-dependent Lyapunov functional is developed which depends on time and the upper bound of the sampling period and also does not grow along the input update times. The controller design problem is solved in terms of the linear matrix inequality method, and the obtained results are less conservative than using the traditional Lyapunov functionals. Finally, a numerical simulation example is built to show the validity of the developed sampled-data control strategy.

  10. Robust adaptive backstepping neural networks control for spacecraft rendezvous and docking with input saturation.

    Science.gov (United States)

    Xia, Kewei; Huo, Wei

    2016-05-01

    This paper presents a robust adaptive neural networks control strategy for spacecraft rendezvous and docking with the coupled position and attitude dynamics under input saturation. Backstepping technique is applied to design a relative attitude controller and a relative position controller, respectively. The dynamics uncertainties are approximated by radial basis function neural networks (RBFNNs). A novel switching controller consists of an adaptive neural networks controller dominating in its active region combined with an extra robust controller to avoid invalidation of the RBFNNs destroying stability of the system outside the neural active region. An auxiliary signal is introduced to compensate the input saturation with anti-windup technique, and a command filter is employed to approximate derivative of the virtual control in the backstepping procedure. Globally uniformly ultimately bounded of the relative states is proved via Lyapunov theory. Simulation example demonstrates effectiveness of the proposed control scheme.

  11. 股骨近端骨折应用髁动力加压板在术后早期非负重功能训练中的作用%The function of the dynamic condylar screw in the early post operational non loading functional exercises for the proximal fracture of femur

    Institute of Scientific and Technical Information of China (English)

    茅治湘; 王鸥; 王全明

    2002-01-01

    @@ Background: Recently, more and more high energy injuries appeared, the proximal fracture of femur was no longer the simple fracture of btween femur tuberosity or below femur tuberosity.It is often accompanied with fracture of the upper femur.For biodynamic and anatomical reasons, such fractures are difficult to deal with,there is often great pressing stress in the inner corner of the neck of the femur, which caused great extending stress in the outer surface.Such fractures are unsteady for any of such stresses would cause the inner immobilization to fail,while to apply the dynamic condylar screw(DCS) on such fractures may got satisfactory results and it provided favorable conditions for the early post operational non loading walking exercises. Objective: To discuss the treating value of DCS in the proximal fracture of the femur.

  12. Sea-based JSOTFs: Considerations for the Operational Planner

    Science.gov (United States)

    2014-05-15

    warfare (NSW) forces to include NSW combatant craft have the capability to rendezvous with ships at sea via parachute .”28 This lack of detailed...During future operations when SOF missions undoubtedly use naval assets not only as a jumping -off point for follow-on tasks inland, but are

  13. Proximity Scanning Transmission Electron Microscopy/Spectroscopy

    CERN Document Server

    Hwang, Ing-Shouh

    2016-01-01

    Here a new microscopic method is proposed to image and characterize very thin samples like few-layer materials, organic molecules, and nanostructures with nanometer or sub-nanometer resolution using electron beams of energies lower than 20 eV. The microscopic technique achieves high resolution through the proximity (or near-field) effect, as in scanning tunneling microscopy (STM), while it also allows detection of transmitted electrons for imaging and spectroscopy, as in scanning transmission electron microscopy (STEM). This proximity transmission electron microscopy (PSTEM) does not require any lens to focus the electron beam. It also allows detailed characterization of the interaction of low-energy electron with materials. PSTEM can operate in a way very similar to scanning tunneling microscopy, which provides high-resolution imaging of geometric and electronic structures of the sample surface. In addition, it allows imaging and characterization of the interior structures of the sample based on the detected...

  14. Fractures of the proximal humerus

    DEFF Research Database (Denmark)

    Brorson, Stig

    2013-01-01

    Fractures of the proximal humerus have been diagnosed and managed since the earliest known surgical texts. For more than four millennia the preferred treatment was forceful traction, closed reduction, and immobilization with linen soaked in combinations of oil, honey, alum, wine, or cerate....... The bandages were further supported by splints made of wood or coarse grass. Healing was expected in forty days. Different fracture patterns have been discussed and classified since Ancient Greece. Current classification of proximal humeral fractures mainly relies on the classifications proposed by Charles......, classification of proximal humeral fractures remains a challenge for the conduct, reporting, and interpretation of clinical trials. The evidence for the benefits of surgery in complex fractures of the proximal humerus is weak. In three systematic reviews I studied the outcome after locking plate osteosynthesis...

  15. The infrastructure of psychological proximity

    DEFF Research Database (Denmark)

    Nickelsen, Niels Christian Mossfeldt

    ). The experience of psychological proximity between patient and nurse is provided through confidence, continuity and the practical set-up. This constitutes an important enactment of skillfulness, which may render telemedicine a convincing health service in the future. Methodology: The study draws on a pilot...... (Langstrup & Winthereik 2008). This study contributes by showing the infrastructure of psychological proximity, which is provided by way of device, confidence, continuity and accountability....

  16. Evaluation of GPS position and attitude determination for automated rendezvous and docking missions. M.S. Thesis

    Science.gov (United States)

    Diprinzio, Marc D.; Tolson, Robert H.

    1994-01-01

    The use of the Global Positioning System for position and attitude determination is evaluated for an automated rendezvous and docking mission. The typical mission scenario involves the chaser docking with the target for resupply or repair purposes, and is divided into three sections. During the homing phase, the chaser utilizes coarse acquisition pseudorange data to approach the target; guidance laws for this stage are investigated. In the second phase, differential carrier phase positioning is utilized. The chaser must maintain a quasiconstant distance from the target, in order to resolve the initial integer ambiguities. Once the ambiguities are determined, the terminal phase is entered, and the rendezvous is completed with continuous carrier phase tracking. Attitude knowledge is maintained in all phases through the use of the carrier phase observable. A Kalman filter is utilized to estimate all states from the noisy measurement data. The effects of selective availability and cycle slips are also investigated.

  17. Acute biliary pancreatitis and cholecystolithiasis in a child:one time treatment with laparoendoscopic "Rendez-vous" procedure

    Institute of Scientific and Technical Information of China (English)

    Gaetano La Greca; Michele Di Blasi; Francesco Barbagallo; Manuela Di Stefano; Saverio Latteri; Domenico Russello

    2006-01-01

    Acute biliary pancreatitis (ABP) is rare in childhood and endoscopic sphincterotomy should be avoided in the child due to the risk of both early and late complications but, when necessary, the optimal timing between endoscopic procedure and cholecystectomy is still uncertain.A nine years old child with acute biliary pancreatitis underwent successfull laparo-endoscopic "Rendez-Vous" procedure in which endoscopic drainage of the common bile duct and laparoscopic cholecystectomy were performed simultaneously. This is the first case reported of laparo-endoscopic Rendez-Vous in a child. The excellent outcome of this patient and the review of the literature concerning other available options for the treatment of such cases suggest that this procedure offers great advantages, especially in children, of reducing the required number of treatments, the risk of ineffectiveness, the number of anaesthesia, the length of hospital stay and the risk of iatrogenic morbidity.

  18. Management of proximal humerus fractures in adults.

    Science.gov (United States)

    Vachtsevanos, Leonidas; Hayden, Lydia; Desai, Aravind S; Dramis, Asterios

    2014-11-18

    The majority of proximal humerus fractures are low-energy osteoporotic injuries in the elderly and their incidence is increasing in the light of an ageing population. The diversity of fracture patterns encountered renders objective classification of prognostic value challenging. Non-operative management has been associated with good functional outcomes in stable, minimally displaced and certain types of displaced fractures. Absolute indications for surgery are infrequent and comprise compound, pathological, multi-fragmentary head-splitting fractures and fracture dislocations, as well as those associated with neurovascular injury. A constantly expanding range of reconstructive and replacement options however has been extending the indications for surgical management of complex proximal humerus fractures. As a result, management decisions are becoming increasingly complicated, in an attempt to provide the best possible treatment for each individual patient, that will successfully address their specific fracture configuration, comorbidities and functional expectations. Our aim was to review the management options available for the full range of proximal humerus fractures in adults, along with their specific advantages, disadvantages and outcomes.

  19. Clinical analysis and operation skills of locking proximal humeral plate in treating proximal humeral fractures%肱骨近端锁定接骨板治疗肱骨近端骨折的临床分析及手术技巧

    Institute of Scientific and Technical Information of China (English)

    张长青; 苏琰; 曾炳芳

    2005-01-01

    目的总结和评价应用肱骨近端锁定接骨板(locking proximal humeral plate,LPHP)治疗肱骨近端骨折的初步临床疗效和手术技巧.方法 2002年12月至2005年1月,应用AO/ASIF的LPHP治疗132例肱骨近端骨折患者,其中男性57例,女性75例;年龄18~79岁,平均58.7岁.根据Neer分类:二部分骨折74例,三部分骨折47例,四部分骨折11例.结果 132例患者随访时间为3~28个月,平均15.6个月.均达到骨性愈合,平均愈合时间为9.2周.根据Neer评分,优良率为82.31%.有2例患者LPHP固定失败.结论 LPHP具有固定稳定,血运破坏少等优点,在正确掌握手术技巧的前提下,是治疗肱骨近端骨折的较好方法.

  20. Phytochemistry and proximate composition of ginger ( Zingiber ...

    African Journals Online (AJOL)

    Phytochemistry and proximate composition of ginger ( Zingiber officinale ) ... steroids, flavonoids and terpenoids were present, while reducing sugars, tannins, oils and ... proximate analysis, Zingiberaceae, zingerone, methanolic extraction

  1. Transverse Stress Fracture of the Proximal Patella

    Science.gov (United States)

    Atsumi, Satoru; Arai, Yuji; Kato, Ko; Nishimura, Akinobu; Nakazora, Shigeto; Nakagawa, Shuji; Ikoma, Kazuya; Fujiwara, Hiroyoshi; Sudo, Akihiro; Kubo, Toshikazu

    2016-01-01

    Abstract Among stress fractures associated with sports activities, patellar stress fracture is rare. Regarding patella stress fractures, so far only distal transverse or lateral longitudinal fractures have been reported, but there are no reports of transverse fractures occurring in the proximal patella. We describe an extremely rare case of transverse stress fracture of proximal patella in a 9-year-old athlete. A 9-year old boy, who participated in sports (sprints and Kendo) presented with left knee pain without any external injury. In plain radiographs, a fracture line was observed in the proximal 1/3 of the left patella, and a patella stress fracture was diagnosed. For treatment, because 7 months of conservative therapy showed no improvement, internal fixation was carried out using Acutrak screws, and bone union was thus achieved. Three months after the operation, he was able to return to his previous level of athletic sports activity. Regarding the mechanism of onset, it is believed that the causes are longitudinal traction force and patellofemoral contact pressure. On the other hand, the contact region of the patella with the femur changes with the flexion angle of the knee. In the current case, the fracture occurred at a site where the patella was in contact with the femur at a flexion angle of >90°, so it is believed that it occurred as a clinical condition from being subjected to repeated longitudinal traction force and patellofemoral contact pressure at a flexion angle of >90°, during the sports activities of sprints and Kendo. The nonunion of the transverse stress fracture of his proximal patella was successfully treated with internal fixation using Acutrak screws. PMID:26871789

  2. Surgical outcome of proximal femoral fractures using proximal femoral - locking compression plate

    Directory of Open Access Journals (Sweden)

    Prakash A. Sasnur

    2015-07-01

    Full Text Available Introduction: Proximal femoral fractures are complex fractures following devastating injuries in young and elderly population. Despite marked improvement in implant design, surgical technique and patient care these fractures are associated with high incidence of implant failure, refracture and varus collapse. Intramedullary nails are technically demanding and associated with high re-operation rates. The study was done to evaluate the outcome of proximal femoral fractures treated with proximal femur locking compression plate (PF-LCP. Methods: This study is conducted at Al Ameen Medical College and Hospital, Bijapur during the period Jan 2012 to March 2014.Pertrochanteric fractures especially unstable intertrochanteric & subtrochanteric fractures were included. Technical difficulties with the implant and operating time were quantified. Union of fracture site and implant related complications were followed up clinically and radiological. The Harris Hip Score was used to evaluate the functional outcome. Results: Thirty-two patients were available for final evaluation with average age of 55.4 years. The average operation time was 1 hour and 35 minutes with mean blood loss of 180ml. Union was achieved in all the cases with an average time of 17 weeks. Complications included one case of delayed union and three cases of varus collapse. Conclusion: PF-LCP achieves anatomical reduction and stable fixation with higher union rate and fewer complications.

  3. Handling Neighbor Discovery and Rendezvous Consistency with Weighted Quorum-Based Approach

    Directory of Open Access Journals (Sweden)

    Chung-Ming Own

    2015-09-01

    Full Text Available Neighbor discovery and the power of sensors play an important role in the formation of Wireless Sensor Networks (WSNs and mobile networks. Many asynchronous protocols based on wake-up time scheduling have been proposed to enable neighbor discovery among neighboring nodes for the energy saving, especially in the difficulty of clock synchronization. However, existing researches are divided two parts with the neighbor-discovery methods, one is the quorum-based protocols and the other is co-primality based protocols. Their distinction is on the arrangements of time slots, the former uses the quorums in the matrix, the latter adopts the numerical analysis. In our study, we propose the weighted heuristic quorum system (WQS, which is based on the quorum algorithm to eliminate redundant paths of active slots. We demonstrate the specification of our system: fewer active slots are required, the referring rate is balanced, and remaining power is considered particularly when a device maintains rendezvous with discovered neighbors. The evaluation results showed that our proposed method can effectively reschedule the active slots and save the computing time of the network system.

  4. Handling Neighbor Discovery and Rendezvous Consistency with Weighted Quorum-Based Approach.

    Science.gov (United States)

    Own, Chung-Ming; Meng, Zhaopeng; Liu, Kehan

    2015-09-03

    Neighbor discovery and the power of sensors play an important role in the formation of Wireless Sensor Networks (WSNs) and mobile networks. Many asynchronous protocols based on wake-up time scheduling have been proposed to enable neighbor discovery among neighboring nodes for the energy saving, especially in the difficulty of clock synchronization. However, existing researches are divided two parts with the neighbor-discovery methods, one is the quorum-based protocols and the other is co-primality based protocols. Their distinction is on the arrangements of time slots, the former uses the quorums in the matrix, the latter adopts the numerical analysis. In our study, we propose the weighted heuristic quorum system (WQS), which is based on the quorum algorithm to eliminate redundant paths of active slots. We demonstrate the specification of our system: fewer active slots are required, the referring rate is balanced, and remaining power is considered particularly when a device maintains rendezvous with discovered neighbors. The evaluation results showed that our proposed method can effectively reschedule the active slots and save the computing time of the network system.

  5. Mating rendezvous in monogenean gill parasites of the humbug Dascyllus aruanus (Pisces: Pomacentridae).

    Science.gov (United States)

    Lo, C M

    1999-12-01

    The gills of the humbug, Dascyllus aruanus (Pomacentridae), were infected by a monogenean genus Haliotrema at a high prevalence (83%) but with a low mean intensity (5.6 worms/fish). All the gill arches of 365 fish, caught on the fringing reef of Moorea Island (French Polynesia), were examined for parasites. Each hemibranch was divided into 12 subequal sections. Monogeneans showing microhabitat overlap were defined as couples. Hosts with low intensity of infection (fewer than 5 monogeneans per gill) were selected and couples were recorded. Among the 37 hosts harboring 2 worms on their gills, 18 fish were infected with these 2 monogeneans on the same gill side of the body; 50% (n = 9) of these harbored monogeneans within the same gill arch and 55% (n = 5) of these last fish showed individual parasites within the same section of the gill. In the case of hosts with few monogeneans (3 and 4 individuals; n = 37) on the same arch, more than 40% (n = 16) harbored worms in couples. There may be some chemical communication that allowed these monogeneans to migrate toward each other and thus enhance mating success. Mating rendezvous appears to be a more important factor than site location for these gill monogeneans.

  6. Time and Covariance Threshold Triggered Optimal Uncooperative Rendezvous Using Angles-Only Navigation

    Directory of Open Access Journals (Sweden)

    Yue You

    2017-01-01

    Full Text Available A time and covariance threshold triggered optimal maneuver planning method is proposed for orbital rendezvous using angles-only navigation (AON. In the context of Yamanaka-Ankersen orbital relative motion equations, the square root unscented Kalman filter (SRUKF AON algorithm is developed to compute the relative state estimations from a low-volume/mass, power saving, and low-cost optical/infrared camera’s observations. Multi-impulsive Hill guidance law is employed in closed-loop linear covariance analysis model, based on which the quantitative relative position robustness and relative velocity robustness index are defined. By balancing fuel consumption, relative position robustness, and relative velocity robustness, we developed a time and covariance threshold triggered two-level optimal maneuver planning method, showing how these results correlate to past methods and missions and how they could potentially influence future ones. Numerical simulation proved that it is feasible to control the spacecraft with a two-line element- (TLE- level uncertain, 34.6% of range, initial relative state to a 100 m v-bar relative station keeping point, at where the trajectory dispersion reduces to 3.5% of range, under a 30% data gap per revolution on account of the eclipse. Comparing with the traditional time triggered maneuver planning method, the final relative position accuracy is improved by one order and the relative trajectory robustness and collision probability are obviously improved and reduced, respectively.

  7. Maximizing the Lifetime of Wireless Sensor Networks Using Multiple Sets of Rendezvous

    Directory of Open Access Journals (Sweden)

    Bo Li

    2015-01-01

    Full Text Available In wireless sensor networks (WSNs, there is a “crowded center effect” where the energy of nodes located near a data sink drains much faster than other nodes resulting in a short network lifetime. To mitigate the “crowded center effect,” rendezvous points (RPs are used to gather data from other nodes. In order to prolong the lifetime of WSN further, we propose using multiple sets of RPs in turn to average the energy consumption of the RPs. The problem is how to select the multiple sets of RPs and how long to use each set of RPs. An optimal algorithm and a heuristic algorithm are proposed to address this problem. The optimal algorithm is highly complex and only suitable for small scale WSN. The performance of the proposed algorithms is evaluated through simulations. The simulation results indicate that the heuristic algorithm approaches the optimal one and that using multiple RP sets can significantly prolong network lifetime.

  8. Design and Clinical Application of Proximal Humerus Memory Connector

    Science.gov (United States)

    Xu, Shuo-Gui; Zhang, Chun-Cai

    2011-02-01

    Treatment for comminuted proximal humerus fractures and nonunions are a substantial challenge for orthopedic surgeons. Plate and screw fixation does not provide enough stability to allow patients to begin functional exercises early after surgery. Using shape memory material nickel titanium alloy, we designed a new device for treating severe comminuted proximal humerus fractures that accommodates for the anatomical features of the proximal humerus. Twenty-two cases of comminuted fracture, malunion, and nonunion of the proximal humerus were treated with the proximal humeral memory connector (PHMC). No external fixation was needed after the operation and patients began active shoulder exercises an average of 8 days after the operation. Follow-up evaluation (mean 18.5 months) revealed that bone healing with lamellar bone formation occurred an average of 3.6 months after surgery for the fracture cases and 4.5 months after surgery for the nonunion cases. Average shoulder function was 88.5 according to the criteria of Michael Reese. PHMC is an effective new device to treat comminuted proximal humerus fractures and nonunions. The use of this device may reduce the need for shoulder joint arthroplasty.

  9. Oscillations in the proximal intratubular pressure: a mathematical model

    DEFF Research Database (Denmark)

    Holstein-Rathlou, N H; Leyssac, P P

    1987-01-01

    This study presents a dynamic continuous time model of the regulation of the renal proximal intratubular pressure in the rat. The model integrates a functional model of the glomerulus, a tubular model, a feedback model, and an afferent arteriolar model. The model has one equilibrium solution...... oscillations in proximal pressure are present. For sustained oscillations to appear, it is necessary for the system's operating point to be located on a sufficiently steep portion of the tubuloglomerular feedback curve. The model analyses are compared with various experimental recordings of the proximal...... intratubular pressure. The model simulations show both spontaneous and induced oscillations in the proximal pressure in close agreement with the experimental results; but the steady-state mean pressure regulation is found to be less efficient in the model than that apparent from the experimental recordings...

  10. Proximal femoral replacement for the treatment of periprosthetic fractures.

    Science.gov (United States)

    Klein, Gregg R; Parvizi, Javad; Rapuri, Venkat; Wolf, Christopher F; Hozack, William J; Sharkey, Peter F; Purtill, James J

    2005-08-01

    A periprosthetic fracture around the femoral component is a rare but potentially problematic complication after total hip arthroplasty. Reconstruction can be challenging, especially when severe bone stock deficiency is encountered. Proximal femoral replacement is one method of treating the severely deficient proximal part of the femur. The present report describes the outcomes of revision total hip arthroplasty with use of a proximal femoral replacement in a cohort of patients who had a Vancouver type-B3 periprosthetic fracture. With use of a computerized institutional database, all patients in whom a Vancouver type-B3 fracture (characterized by severe proximal bone deficiency and a loose femoral stem) had been treated with a proximal femoral replacement were identified. A modular femoral replacement with proximal porous coating had been used in all cases. The twenty-one patients who were identified had had a mean age of 78.3 years (range, fifty-two to ninety years) at the time of the index operation. The clinical and radiographic records of these patients were reviewed. At the time of the latest follow-up (mean, 3.2 years), all but one of the patients were able to walk and had minimal to no pain. Complications included persistent wound drainage that was treated with incision and drainage (two hips), dislocation (two hips), refracture of the femur distal to the stem (one hip), and acetabular cage failure (one hip). Despite a relatively high complication rate, we believe that proximal femoral replacement is a viable option for the treatment of periprosthetic fractures in older patients with severe bone deficiency. If a proximal femoral replacement is used, the stability of the hip must be tested diligently intraoperatively and a constrained acetabular liner should be utilized if instability is encountered. In order to enhance the bone stock, the proximal part of the femur, however poor in quality, should be retained for reapproximation onto the implant.

  11. Spacecraft Rendevouz and Docking. An Autonomy assisted Human Operator Approach

    DEFF Research Database (Denmark)

    Jørgensen, John Leif; Thuesen, Gøsta

    1999-01-01

    The phenomena and problems encountered when a rendezvous maneuver, and possible docking, of two spacecrafts has to be performed, have been the topic for numerous studies and details of a variety of scenarios has been analyzed. So far, all solutions that have been brought into realization have been...... based entirely on direct human supervision and control.This paper describes a vision based system and methodology, that autonomously generates accurate guidance information that may assist a human operator in performing the tasks associated with both the rendezvous and docking navigation procedures...... information to assist the human operator during the docking phase.The closed loop and operator assistance performance of the system have been assessed using a test bench including human operator, navigation module and high fidelity visualization module.The tests performed verified the general accuracy, real...

  12. A Prediction Method of TV Camera Image for Space Manual-control Rendezvous and Docking

    Science.gov (United States)

    Zhen, Huang; Qing, Yang; Wenrui, Wu

    Space manual-control rendezvous and docking (RVD) is a key technology for accomplishing the RVD mission in manned space engineering, especially when automatic control system is out of work. The pilot on chase spacecraft manipulates the hand-stick by the image of target spacecraft captured by TV camera. From the TV image, the relative position and attitude of chase and target spacecrafts can be shown. Therefore, the size, the position, the brightness and the shadow of the target on TV camera are key to guarantee the success of manual-control RVD. A method of predicting the on-orbit TV camera image at different relative positions and light conditions during the process of RVD is discussed. Firstly, the basic principle of capturing the image of cross drone on target spacecraft by TV camera is analyzed theoretically, based which the strategy of manual-control RVD is discussed in detail. Secondly, the relationship between the displayed size or position and the real relative distance of chase and target spacecrafts is presented, the brightness and reflection by the target spacecraft at different light conditions are decribed, the shadow on cross drone caused by the chase or target spacecraft is analyzed. Thirdly, a prediction method of on-orbit TV camera images at certain orbit and light condition is provided, and the characteristics of TV camera image during the RVD is analyzed. Finally, the size, the position, the brightness and the shadow of target spacecraft on TV camera image at typical orbit is simulated. The result, by comparing the simulated images with the real images captured by the TV camera on Shenzhou manned spaceship , shows that the prediction method is reasonable

  13. Mission analysis and guidance, navigation, and control design for rendezvous and docking phase of advanced reentry vehicle mission

    Science.gov (United States)

    Strippoli, L.; Colmenarejo, P.; Strauch, H.

    2013-12-01

    Advanced Reentry Vehicle (ARV) belongs to the family of vehicles designed to perform rendezvous and docking (RvD) with the International space station (ISS) [1]. Differently from its predecessor ATV (Automated Transfer Vehicle), the ARV will transport a reentry capsule, equipped with a heatshield and able to bring back cargo, experiments, or, as a possible future development, even crew, being this latter scenario very attracting in view of the Space Shuttle retirement. GMV, as subcontractor of EADS-Astrium Germany, is in charge of the RvD and departure mission analysis and GNC (Guidance, Navigation, and Control) design of ARV mission. This paper will present the main outcomes of the study.

  14. Intramedullary Chondrosarcoma of Proximal Humerus

    Directory of Open Access Journals (Sweden)

    Pratiksha Yadav

    2012-01-01

    Full Text Available Primary chondrosarcoma is the third most frequent primary malignancy of bone after myeloma and osteosarcoma. It is ranging from slow growing nonmetastasising lesions to highly aggressive lesions. We report a case of primary intramedullary chondrosarcoma of proximal humerus. A 60-year-old female presented with pain and hard swelling involving the left arm for 5 months. Radiograph showed a lucent expansile intramedullary lesion with matrix calcification and associated soft tissue mass. CT confirmed the finding. MRI showed a lobulated lesion which is hyperintense on T2WI with low signal fibrous septae. Increased tracer uptake was seen on bone scan. Histopathology confirmed the radiology diagnosis. The patient underwent wide resection and endoprosthetic reconstruction of proximal humerus.

  15. Proximate analysis for amazon biomass

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Antonio Geraldo de Paula; Feitosa Netto, Genesio Batista; Nogueira, Manoel Fernandes Martins; Coutinho, Manoel Fernandes Martins; Coutinho, Hebert Willian Martins; Rendeiro, Goncalo [Universidade Federal do Para (UFPA), Belem, PA (Brazil). Lab. de Engenharia Mecanica (LABGAS)], e-mail: ageraldo@ufpa.br, e-mail: mfmn@ufpa.br, e-mail: rendeiro@ufpa.br

    2006-07-01

    In order to asses the potentiality of Amazon biomass to generate power, either to supply electric energy to the grid or as fuel to plants supplying power for off-grid location, data for their proximate analysis must be available. A literature review on the subject indicated a lack of information and data concerning typical Amazon rain forest species. This work aimed to characterize (proximate analysis) 80 Amazon species in order to evaluate the energy resource from woody biomass wastes in Amazon region. Higher Heating Value, Carbon, Volatile and Ash contents were measured in a dry basis. The measurements were performed obeying the following Brazilian standards, NBR 6923, NBR 8112, NBR 8633, NBR 6922. (author)

  16. Proximal clavicle excision: an analysis of results.

    Science.gov (United States)

    Acus, R W; Bell, R H; Fisher, D L

    1995-01-01

    Medial clavicle excision has been reported by several authors, but few cases are documented, and long-term follow-up information is lacking. The purpose of this study was to examine the long-term results of medial clavicle excision in regard to function, pain, cosmesis, and complications. Fifteen patients ranging in age from 18 to 64 years (average 43 years) were evaluated an average of 4.6 years (range 1 to 14 years) after proximal clavicle excision. The indications for excision were unstable anterior subluxation/dislocation of the sternoclavicular joint (four cases), unstable posterior dislocation (one case), sternoclavicular osteoarthritis (nine cases), and proximal clavicle osteomyelitis (one case). An average of 2.9 cm of the medial clavicle was excised (range 1 to 4 cm). Fourteen of the 15 patients received significant relief of pain. On a strict grading scale four patients had an excellent result, five a good result, four a fair result, and two a poor result. Regeneration of the clavicle appeared to contribute to a poor result. No operative complications occurred. These findings aid our understanding of surgical options and outcome in the treatment of sternoclavicular joint disease.

  17. Plating of proximal humeral fractures.

    Science.gov (United States)

    Martetschläger, Frank; Siebenlist, Sebastian; Weier, Michael; Sandmann, Gunther; Ahrens, Philipp; Braun, Karl; Elser, Florian; Stöckle, Ulrich; Freude, Thomas

    2012-11-01

    The optimal treatment for proximal humeral fractures is controversial. Few data exist concerning the influence of the surgical approach on the outcome. The purpose of this study was to evaluate the clinical and radiological outcomes of proximal humeral fractures treated with locking plate fixation through a deltopectoral vs an anterolateral deltoid-splitting approach. Of 86 patients who met the inclusion criteria, 70 were available for follow-up examination. Thirty-three patients were treated through a deltopectoral approach and 37 through an anterolateral deltoid-splitting approach. In all cases, open reduction and internal fixation with a PHILOS locking plate (Synthes, Umkirch, Germany) was performed. Clinical follow-up included evaluation of pain, shoulder mobility, and strength. Constant score and Disabilities of the Arm, Shoulder and Hand (DASH) score were assessed. A clinical neurological examination of the axillary nerve was also performed. Consolidation, reduction, and appearance of head necrosis were evaluated radiographically. After a mean follow-up of 33 months, Constant scores, DASH scores, and American Shoulder and Elbow Surgeons scores showed no significant differences between the groups. Clinical neurologic examination of the axillary nerve revealed no obvious damage to the nerve in either group. Deltopectoral and anterolateral detoid-splitting approaches for plate fixation of proximal humeral fractures are safe and provide similar clinical outcomes. The results of this study suggest that the approach can be chosen according to surgeon preference.

  18. Ash Aggregates in Proximal Settings

    Science.gov (United States)

    Porritt, L. A.; Russell, K.

    2012-12-01

    Ash aggregates are thought to have formed within and been deposited by the eruption column and plume and dilute density currents and their associated ash clouds. Moist, turbulent ash clouds are considered critical to ash aggregate formation by facilitating both collision and adhesion of particles. Consequently, they are most commonly found in distal deposits. Proximal deposits containing ash aggregates are less commonly observed but do occur. Here we describe two occurrences of vent proximal ash aggregate-rich deposits; the first within a kimberlite pipe where coated ash pellets and accretionary lapilli are found within the intra-vent sequence; and the second in a glaciovolcanic setting where cored pellets (armoured lapilli) occur within Diamond Mine, Canada, are the residual deposits within the conduit and vent of the volcano and are characterised by an abundance of ash aggregates. Coated ash pellets are dominant but are followed in abundance by ash pellets, accretionary lapilli and rare cored pellets. The coated ash pellets typically range from 1 - 5 mm in diameter and have core to rim ratios of approximately 10:1. The formation and preservation of these aggregates elucidates the style and nature of the explosive phase of kimberlite eruption at A418 (and other pipes?). First, these pyroclasts dictate the intensity of the kimberlite eruption; it must be energetic enough to cause intense fragmentation of the kimberlite to produce a substantial volume of very fine ash (sustained plume attended by concomitant production of pyroclastic density currents. The size and internal structure of the armoured lapilli provide constraints on the nature of the initial explosive phase of eruption at Kima'Kho. Their proximity to the vent also indicates rapid aggregation within the eruption plume. Within both sequences rapid aggregation of ash particles occurred in proximity to the vent. However, the conditions were substantially different leading to the production of armoured

  19. [Proximal and total femur replacement].

    Science.gov (United States)

    Pennekamp, P H; Wirtz, D C; Dürr, H R

    2012-07-01

    Reconstruction of segmental bone defects of the proximal femur following wide tumor resection or revision arthroplasty. Aggressive benign or primary malignant bone tumors of the proximal femur; destructive metastases; massive segmental bone defects of the proximal femur; periprosthetic fractures. Local infection; very short life expectancy (acetabular bone stock. Anterolateral approach. Exposure and detachment of the iliopsoas and gluteus medius muscle from the proximal femur with a sufficient safety margin to the bone; distal transsection of the vastus lateralis/intermedius and rectus femoris muscle according to the extraosseous tumor extension; distal femur osteotomy al least 3 cm beyond the farthest point of tumor extension; in case of total femur replacement, additional lateral arthrotomy of the knee with resection of the ligaments and menisci; reaming of the medullary canal after securing the shaft with a Verbrugge clamp; trial assembly and reduction followed by the definitive implantation of the prosthesis with adjustment of the femoral neck anteversion in 5° increments; soft tissue reconstruction and fixation to an attachment tube covering the prosthesis; in case of total femur replacement, the preparation of the tibia is followed by the coupling of the tibial and femoral components. Infection prophylaxis, 20 kg partial weight bearing, continuous passive motion. A total of 20  patients with proximal femur replacement and 2 patients with total femur replacement implanted between June 2007 and December 2011 were retrospectively reviewed. Three patients had primary malignant bone tumors, while 19 patients underwent resection for metastatic disease. The mean age at surgery was 62.0 ± 18.1 years (18-82 years). Fifteen patients with a mean follow-up of 20.3 ± 17.2 months (4-51 months) were studied. Among the 22 cases, periprosthetic infection occurred in 3 patients (13.6%), dislocation in 2 patients (9.1%). Evaluation of the functional

  20. Critical Proximity as a Methodological Move in Techno-Anthropology

    DEFF Research Database (Denmark)

    Birkbak, Andreas; Petersen, Morten Krogh; Elgaard Jensen, Torben

    2015-01-01

    work through two cases—one on the involvement of users in innovation projects and another on commercial web technologies for tracing issues—to show how critical proximity may be practiced. We sum up the lessons derived in four methodological guidelines for doing research with critical proximity.......echno-Anthropology is a new field, operating with a broad range of methodologies and approaches. This gives rise to the question: What does it mean for Techno-Anthropological research to be critical? In this paper, we discuss this question by developing and specifying the notion of ‘critical...

  1. Proximate composition, bread characteristics and sensory ...

    African Journals Online (AJOL)

    Proximate composition, bread characteristics and sensory evaluation of ... African Journal of Food, Agriculture, Nutrition and Development ... This study was carried out to investigate proximate composition, bread characteristics and sensory ...

  2. Rendezvous technique treatment for late-onset biliary leakage after major hepatectomy of a living donor: report of a case.

    Science.gov (United States)

    Kimura, Koichi; Ikegami, Toru; Yamashita, Yo-ichi; Saeki, Hiroshi; Oki, Eiji; Yoshizumi, Tomoharu; Uchiyama, Hideaki; Kawanaka, Hirofumi; Soejima, Yuji; Morita, Masaru; Shirabe, Ken; Ikeda, Tetsuo; Maehara, Yoshihiko

    2013-09-01

    Biliary leakage is a major complication after hepatectomy. We report the case of a living-donor liver transplantation (LDLT) donor with a late-onset bile leak from the trifurcation of the hepatic duct who was successfully treated using rendezvous technique. A 52-year-old man underwent extended left hepatectomy for donation and was discharged on postoperative day (PD) 13. However, he was rehospitalized on PD 26 with severe abdominal pain. Physical examination suggested panperitonitis, and abdominocentesis showed bilious ascites. Emergent laparotomy for biliary leakage and peritonitis was performed. There was bilious ascites in the peritoneal cavity. A biliary fistula was recognized at the trifurcation of B8a, B8b, and B5. Intraoperative transhepatic biliary drainage of each bile duct was performed. Endoscopic transpapillary drainage was performed on PD 24. Finally, external drains were removed and complete internal drainage established on PD 70. The bile leak was considered to be the result of injury from electrocautery device. Appropriate making choices of the electrocautery devices enable us to avoid over thermal injury of the liver surface. Rendezvous bidirectional drainage effectively treated late-onset bile leakage from the trifurcation of a hepatic bile duct.

  3. Rapid coal proximate analysis by thermogravimetric method

    Energy Technology Data Exchange (ETDEWEB)

    Mao Jianxiong; Yang Dezhong; Zhao Baozhong

    1987-09-01

    A rapid coal proximate analysis by thermogravimetric analysis (TGA) can be used as an alternative method for the standard proximate analysis. This paper presents a program set up to rapidly perform coal proximate analysis by using a thermal analyzer and TGA module. A comparison between coal proximate analyses by standard method (GB) and TGA is also given. It shows that most data from TGA fall within the tolerance limit of standard method.

  4. Two-Step Proximal Gradient Algorithm for Low-Rank Matrix Completion

    Directory of Open Access Journals (Sweden)

    Qiuyu Wang

    2016-06-01

    Full Text Available In this paper, we  propose a two-step proximal gradient algorithm to solve nuclear norm regularized least squares for the purpose of recovering low-rank data matrix from sampling of its entries. Each iteration generated by the proposed algorithm is a combination of the latest three points, namely, the previous point, the current iterate, and its proximal gradient point. This algorithm preserves the computational simplicity of classical proximal gradient algorithm where a singular value decomposition in proximal operator is involved. Global convergence is followed directly in the literature. Numerical results are reported to show the efficiency of the algorithm.

  5. Biomass proximate analysis using thermogravimetry.

    Science.gov (United States)

    García, Roberto; Pizarro, Consuelo; Lavín, Antonio G; Bueno, Julio L

    2013-07-01

    This work proposes a 25 min-last thermogravimetric method as a tool to determine biomass sample's proximate analysis data (moisture, ash, volatile matter and fixed carbon contents) just by direct measure of weight changes on each sample's TG chart. Compared with international standards commonly used to that aim, TG is a faster and easier to develop technique. Obtained results were satisfactory, with AEE under 6% for moisture and volatile matter, close to 10% for fixed carbon determination and AAD of 1.6 points for ash content.

  6. Equilibrium properties of proximity effect

    Energy Technology Data Exchange (ETDEWEB)

    Esteve, D.; Pothier, H.; Gueron, S.; Birge, N.O.; Devoret, M.

    1996-12-31

    The proximity effect in diffusive normal-superconducting (NS) nano-structures is described by the Usadel equations for the electron pair correlations. We show that these equations obey a variational principle with a potential which generalizes the Ginzburg-Landau energy functional. We discuss simple examples of NS circuits using this formalism. In order to test the theoretical predictions of the Usadel equations, we have measured the density of states as a function of energy on a long N wire in contact with a S wire at one end, at different distances from the NS interface. (authors). 12 refs.

  7. 带血管蒂腓骨移植及人工关节置换修复邻近关节良性骨肿瘤所致骨缺损%Operative treatment of benign bone tumor defects in proximal joint by fibula transplantation with vascular and artificial joint replacement.

    Institute of Scientific and Technical Information of China (English)

    傅晨; 周巧玲; 时代; 潘晓瑾; 徐饶; 崔后春; 张明建; 王汝渔

    2008-01-01

    Objective To explore the reconstructive methods of benign bone tumor defects in proximal joint. Methods Operative treatment was performed in 11 cases with benign bone tumor defects in proximal joint, a-mong whom 4 cases were treated by curettage,cauterization of wall and bone grafting,3 cases were treated by filling branch through segment fibula transplantation with vascular,2 cases were treated by fibula head transplantation with vascular to reconstruct the glenohumeral joint and rediocarpal joint, and 2 cases were treated by artificial joint re-placement. Results The follow-up ranged from 1.5 to 6 years. All of cases got excellent bone unioned without re-lapse and 2 cases of them developed with little limitation in joint function. Conclusion The importance and recon-structive achievement of fibula transplantation in treating the benign bone tumor defects in proximal joint should be thought fully. The indication of artificial tumor prosthesis replacement should be strictly mastered.%目的 探讨邻近关节良性骨肿瘤所致骨缺损的修复方法 .方法 对11例邻近关节之良性骨肿瘤所致骨缺损进行手术处理,其中4例行肿瘤刮除、瘤壁烧灼加植骨术,3例行带血管节段性腓骨移植充填支撑加植骨术,2例行带血管腓骨小头移植重建盂肱及桡腕关节术,2例行人工肿瘤型假体置换术.结果 经1.5~6年随访,所有病例骨愈合均满意,肿瘤无复发,其中2例关节功能轻度障碍.结论 处理邻近关节的良性骨肿瘤所致骨缺损的修复,应充分考虑腓骨作为移植材料的重要性和修复能力.行人工肿瘤型假体置换应严格掌握适应证.

  8. Predictive factors for functional outcome and failure in angular stable osteosynthesis of the proximal humerus.

    LENUS (Irish Health Repository)

    Hardeman, Francois

    2012-02-01

    Angular stable osteosynthesis has become the gold standard in the operative treatment of proximal humeral fractures. The aim of this article is to determine the indications for osteosynthesis versus primary arthroplasty based on clinical and radiological parameters.

  9. Mission Planning of Fast Rendezvous Strategy around the Moon%环月远程快速交会任务规划

    Institute of Scientific and Technical Information of China (English)

    陈欢; 张洪礼; 韩潮; 彭坤; 马晓兵; 胡雯婷

    2016-01-01

    Co⁃ellipse fast rendezvous strategy was presented as the standard strategy for the remote rendezvous between the lunar module and the command and service module around the moon in a manned landing and return mission. Fuel⁃optimal co⁃ellipse fast rendezvous strategy considering the constraints of total rendezvous time, maneuver time interval and fuel⁃optimal efficiency, and time⁃optimal co⁃ellipse fast rendezvous strategy considering the constraints of total velocity increment, ma⁃neuver time interval and time⁃optimal efficiency, were introduced. Several numerical simulations were conducted to test the feasibility and precision of the standard, fuel⁃optimal and time⁃optimal co⁃ellipse rendezvous strategies. Analysis of the relationship between the total velocity increment and the rendezvous time was also conducted to confirm the feasibility of the optimal strategies.%针对载人登月返回任务中月面上升舱与指挥服务舱的环月远程快速交会问题,以共椭圆快速交会策略为标称策略,并给出摄动模型下的修正方法。给出考虑总交会时间约束、机动时间间隔约束和燃料优化效率的燃料最优共椭圆快速交会策略,以及考虑总速度增量约束、机动时间间隔约束和时间优化效率的时间最优共椭圆快速交会策略。通过算例仿真验证了共椭圆快速交会策略的可行性以及摄动模型下的交会精度,对共椭圆快速交会策略的总速度增量与交会时间的关系进行分析,并对比燃料最优和时间最优共椭圆快速交会对接策略,证明了优化策略的有效性。

  10. Global fuel consumption optimization of an open-time terminal rendezvous and docking with large-eccentricity elliptic-orbit by the method of interval analysis

    Science.gov (United States)

    Ma, Hongliang; Xu, Shijie

    2016-11-01

    By defining two open-time impulse points, the optimization of a two-impulse, open-time terminal rendezvous and docking with target spacecraft on large-eccentricity elliptical orbit is proposed in this paper. The purpose of optimization is to minimize the velocity increment for a terminal elliptic-reference-orbit rendezvous and docking. Current methods for solving this type of optimization problem include for example genetic algorithms and gradient based optimization. Unlike these methods, interval methods can guarantee that the globally best solution is found for a given parameterization of the input. The non-linear Tschauner- Hempel(TH) equations of the state transitions for a terminal elliptic target orbit are transformed form time domain to target orbital true anomaly domain. Their homogenous solutions and approximate state transition matrix for the control with a short true anomaly interval can be used to avoid interval integration. The interval branch and bound optimization algorithm is introduced for solving the presented rendezvous and docking optimization problem and optimizing two open-time impulse points and thruster pulse amplitudes, which systematically eliminates parts of the control and open-time input spaces that do not satisfy the path and final time state constraints. Several numerical examples are undertaken to validate the interval optimization algorithm. The results indicate that the sufficiently narrow spaces containing the global optimization solution for the open-time two-impulse terminal rendezvous and docking with target spacecraft on large-eccentricity elliptical orbit can be obtained by the interval algorithm (IA). Combining the gradient-based method, the global optimization solution for the discontinuous nonconvex optimization problem in the specifically remained search space can be found. Interval analysis is shown to be a useful tool and preponderant in the discontinuous nonconvex optimization problem of the terminal rendezvous and

  11. Data Processing for the Near Earth Asteroid Rendezvous (NEAR), X-Ray and Gamma-Ray Spectrometer (XRS) Ground System

    Science.gov (United States)

    McClanahan, Timothy P.; Mikheeva, I.; Trombka, J. I.; Floyd, S. R.; Boynton, W. V.; Bailey, H.; Bhangoo, J.; Starr, R.; Clark, P. E.; Evans, L. G.

    1999-01-01

    An X-ray and Gamma-ray spectrometer (XGRS) is onboard the Near Earth Asteroid Rendezvous (NEAR) spacecraft to determine the elemental composition of the surface of the asteroid 433Eros. The Eros asteroid is highly non-spherical in physical shape and the development of data management and analysis methodologies are in several areas a divergence from traditional remotely sensed geographical information systems techniques. Field of view and asteroid surface geometry must be derived virtually and then combined with real measurements of solar, spectral and instrument calibration information to derive meaningful scientific results. Spatial resolution of planned geochemical maps will be improved from the initial conditions of low statistical significance per integration by repeated surface flyovers and regional spectral accumulation. This paper describes the results of a collaborative effort of design and development of the NEAR XGRS instrument ground system undertaken by participants at the Goddard Space Flight Center, University of Arizona, Cornell University, Applied Physics Laboratory, and Max Plank institute.

  12. Data Processing for the Near Earth Asteroid Rendezvous (NEAR), X-ray and Gamma-ray Spectrometer (XGRS) Ground System

    Science.gov (United States)

    McClanahan, Timothy P.; Mikheeva, I.; Trombka, J. I.; Floyd, S. R.; Boynton, W. V.; Bailey, H.; Bhangoo, J.; Starr, R.; Clark, P. E.; Evans, L. G.

    1999-01-01

    An X-ray and Gamma-ray spectrometer (XGRS) is onboard the Near Earth Asteroid Rendezvous (NEAR) spacecraft to determine the elemental composition of the surface of the asteroid 433Eros. The Eros asteroid is highly non-spherical in physical shape and the development of data management and analysis methodologies are in several areas a divergence from traditional remotely sensed geographical information systems techniques. Field of view and asteroid surface geometry must be derived virtually and then combined with real measurements of solar, spectral and instrument calibration information to derive meaningful scientific results. Spatial resolution of planned geochemical maps will be improved from the initial conditions of low statistical significance per integration by repeated surface flyovers and regional spectral accumulation. This paper describes the results of a collaborative effort of design and development of the NEAR XGRS instrument ground system undertaken by participants at the Goddard Space Flight Center, University of Arizona, Cornell University, Applied Physics Laboratory, and Max Plank institute.

  13. Spacecraft Actuator Diagnosis with Principal Component Analysis: Application to the Rendez-Vous Phase of the Mars Sample Return Mission

    Directory of Open Access Journals (Sweden)

    Othman Nasri

    2015-01-01

    Full Text Available This paper presents a fault detection and isolation (FDI approach in order to detect and isolate actuators (thrusters and reaction wheels faults of an autonomous spacecraft involved in the rendez-vous phase of the Mars Sample Return (MSR mission. The principal component analysis (PCA has been adopted to estimate the relationships between the various variables of the process. To ensure the feasibility of the proposed FDI approach, a set of data provided by the industrial “high-fidelity” simulator of the MSR and representing the opening (resp., the rotation rates of the spacecraft thrusters (resp., reaction wheels has been considered. The test results demonstrate that the fault detection and isolation are successfully accomplished.

  14. Concurrent engineering: Spacecraft and mission operations system design

    Science.gov (United States)

    Landshof, J. A.; Harvey, R. J.; Marshall, M. H.

    1994-01-01

    Despite our awareness of the mission design process, spacecraft historically have been designed and developed by one team and then turned over as a system to the Mission Operations organization to operate on-orbit. By applying concurrent engineering techniques and envisioning operability as an essential characteristic of spacecraft design, tradeoffs can be made in the overall mission design to minimize mission lifetime cost. Lessons learned from previous spacecraft missions will be described, as well as the implementation of concurrent mission operations and spacecraft engineering for the Near Earth Asteroid Rendezvous (NEAR) program.

  15. Fully automated apparatus for the proximate analysis of coals

    Energy Technology Data Exchange (ETDEWEB)

    Fukumoto, K.; Ishibashi, Y.; Ishii, T.; Maeda, K.; Ogawa, A.; Gotoh, K.

    1985-01-01

    The authors report the development of fully-automated equipment for the proximate analysis of coals, a development undertaken with the twin aims of labour-saving and developing robot applications technology. This system comprises a balance, electric furnaces, a sulfur analyzer, etc., arranged concentrically around a multi-jointed robot which automatically performs all the necessary operations, such as sampling and weighing the materials for analysis, and inserting and removing them from the furnaces. 2 references.

  16. UAS Architecture for Distributed Sensing Operations Project

    Data.gov (United States)

    National Aeronautics and Space Administration — NASA seeks Unmanned Aircraft Systems (UASs) for Earth science data collection for missions with variable durations, operating proximities, altitudes, and...

  17. Grouping by proximity in haptic contour detection.

    Directory of Open Access Journals (Sweden)

    Krista E Overvliet

    Full Text Available We investigated the applicability of the Gestalt principle of perceptual grouping by proximity in the haptic modality. To do so, we investigated the influence of element proximity on haptic contour detection. In the course of four sessions ten participants performed a haptic contour detection task in which they freely explored a haptic random dot display that contained a contour in 50% of the trials. A contour was defined by a higher density of elements (raised dots, relative to the background surface. Proximity of the contour elements as well as the average proximity of background elements was systematically varied. We hypothesized that if proximity of contour elements influences haptic contour detection, detection will be more likely when contour elements are in closer proximity. This should be irrespective of the ratio with the proximity of the background elements. Results showed indeed that the closer the contour elements were, the higher the detection rates. Moreover, this was the case independent of the contour/background ratio. We conclude that the Gestalt law of proximity applies to haptic contour detection.

  18. NEAR Shoemaker spacecraft mission operations

    Science.gov (United States)

    Holdridge, Mark E.

    2002-01-01

    On 12 February 2001, Near Earth Asteroid Rendezvous (NEAR) Shoemaker became the first spacecraft to land on a small body, 433 Eros. Prior to that historic event, NEAR was the first-ever orbital mission about an asteroid. The mission presented general challenges associated with other planetary space missions as well as challenges unique to an inaugural mission around a small body. The NEAR team performed this operations feat with processes and tools developed during the 4-year-long cruise to Eros. Adding to the success of this historic mission was the cooperation among the NEAR science, navigation, guidance and control, mission design, and software teams. With clearly defined team roles, overlaps in responsibilities were minimized, as were the associated costs. This article discusses the processes and systems developed at APL that enabled the success of NEAR mission operations.

  19. Non-Scanning 3D Imager for Autonomous Rendezvous and Docking Project

    Data.gov (United States)

    National Aeronautics and Space Administration — One of the technology pushes in the Human Exploration and Operations (HEO) line-of-business (LOB) is to develop low-latency telerobotics / robotic servicing...

  20. Research on proximity effect of electromagnetic railgun

    Directory of Open Access Journals (Sweden)

    Yu-tao Lou

    2016-06-01

    Full Text Available The rails of electromagnetic railgun can be ablated by the temperature rise due to current concentration. The current distributions on the rails and armature are not only affected by the skin effect, but also influenced by the proximity effect which is rarely mentioned. This paper illustrated the difference between skin effect and proximity effect, and the influencing factors of proximity effect were investigated. Results show that the current is concentrated on the surface around rails due to the skin effect, and the proximity effect exacerbates the current density on the inner surfaces of rails. Decrease in distance from rails enhances the proximity effect, but has nothing to do with the skin effect, which also augments the rail resistance, resulting in temperature rise. It can explain the reason why the ablation is often detected in the small caliber railgun. Research results in this paper can provide support for design and optimization of electromagnetic railgun.

  1. Using a Bore Sight Camera as an AR&D Sensor Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Orion requires a rendezvous and docking sensor to provide relative navigation information during proximity operations and docking. In order to dock, the sensor must...

  2. 腓肠神经营养血管皮瓣修复胫骨上段肿瘤切除后软组织缺损的术后护理%Post-operative nursing of sural neurovascular flap to repair soft tissue defect followed by proximal tibial tumor resection

    Institute of Scientific and Technical Information of China (English)

    王蔚; 马毳; 郑晓缺

    2009-01-01

    目的 探讨腓肠神经营养血管皮瓣修复胫骨上段肿瘤切除后软组织缺损术后的临床特点及护理,以提高临床护理水平.方法 对52例腓肠神经营养血管皮瓣修复胫骨上段肿瘤切除后软组织缺损术后的血运情况进行严密观察,制定个性化护理措施,观察护理效果.结果 52例中48例皮瓣全部存活;3例边缘坏死合并水泡,经换药治愈;1例部分坏死经植皮治愈.全部病例经3~18个月随访,均恢复行走功能.结论 严密细致的观察和行之有效的护理措施,是皮瓣修复手术成功的重要保障之一.%Objective To study the clinical features and nursing of patients operated with sural neuro-vascular flap for repairing soft tissue defect after proximal tibial tumor resection, and to advance the clinical nursing level. Methods The flap's circulation was carefully observed and individual measure was constituted to nurse 52 patients underwent sural neuro-vascular flap to repair soft tissue defect followed by tumor resection in the superior segment of shin bone. The nursing effect was observed. Results Among the 52 cases, 48 flaps survived well. 3 flaps presented marginal necrosis and bubble and healed after dressing change, while 1 flap presented partial necrosis and healed after skin grafting. 52 patients operated with this technique could recover to walk after 3~18 months of follow-up visit. Conclusions Careful observation and effective nursing measure are one of the guarantees that ensure the flap repair operation success.

  3. Proximal Alternating Direction Method with Relaxed Proximal Parameters for the Least Squares Covariance Adjustment Problem

    Directory of Open Access Journals (Sweden)

    Minghua Xu

    2014-01-01

    Full Text Available We consider the problem of seeking a symmetric positive semidefinite matrix in a closed convex set to approximate a given matrix. This problem may arise in several areas of numerical linear algebra or come from finance industry or statistics and thus has many applications. For solving this class of matrix optimization problems, many methods have been proposed in the literature. The proximal alternating direction method is one of those methods which can be easily applied to solve these matrix optimization problems. Generally, the proximal parameters of the proximal alternating direction method are greater than zero. In this paper, we conclude that the restriction on the proximal parameters can be relaxed for solving this kind of matrix optimization problems. Numerical experiments also show that the proximal alternating direction method with the relaxed proximal parameters is convergent and generally has a better performance than the classical proximal alternating direction method.

  4. Superficial temporal artery to proximal posterior cerebral artery bypass through the anterior temporal approach

    Directory of Open Access Journals (Sweden)

    Satoru Takeuchi

    2015-01-01

    Full Text Available Background: The superficial temporal artery (STA to proximal posterior cerebral artery (PCA (P2 segment bypass is one of the most difficult procedures to perform because the proximal PCA is located deep and high within the ambient cistern. STA to proximal PCA bypass is usually performed through a subtemporal approach or posterior transpetrosal approach, and rarely through a transsylvian approach. The aim of this study was to describe the operative technique of STA to proximal PCA bypass through a modified transsylvian approach (anterior temporal approach. Methods: STA to proximal PCA bypass was performed through an anterior temporal approach in three patients with intracranial aneurysm. We describe the details of the surgical technique. Results: The STA was successfully anastomosed to the proximal PCA in all cases. One patient suffered hemiparesis and aphasia due to infarction in the anterior thalamoperforating artery territory. Conclusions: STA to proximal PCA bypass can be performed through an anterior temporal approach in selected patients. We recommend that every precaution, including complete hemostasis, placement of cellulose sponges beneath the recipient artery to elevate the site of the anastomosis, and placement of a continuous drainage tube at the bottom of the operative field to avoid blood contamination during the anastomosis, should be taken to shorten the temporary occlusion time.

  5. Pediatric Scaphoid Proximal Pole Nonunion With Avascular Necrosis.

    Science.gov (United States)

    Jernigan, Edward W; Smetana, Brandon S; Patterson, J Megan M

    2017-04-01

    A 13-year-old, right hand-dominant, otherwise healthy boy presented with left wrist pain 19 months after a nonmotorized scooter injury. Radiographs and magnetic resonance imaging at presentation demonstrated proximal pole scaphoid nonunion with avascular necrosis of the proximal fragment. Operative and nonsurgical treatment options were discussed and the family elected for an attempt at nonsurgical management. The patient was placed in a short-arm thumb spica cast, with a window for a bone stimulator, for 14 weeks. At the conclusion of the treatment, the pain had resolved and x-ray and computed tomography scan demonstrated bony union. The authors recommend considering an initial trial of nonsurgical management for treatment of all pediatric scaphoid nonunions. Copyright © 2017 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

  6. Laser Proximity Sensor for Fuel-air Explosive Bomb

    Directory of Open Access Journals (Sweden)

    Durga Singh

    2007-05-01

    Full Text Available Present study deals with design and development aspects of a diode laser proximity sensorbased on principle of optical triangulation. This sensor incorporates a laser transmitter and anoptical receiver. The beam divergence of laser transmitter and look angle of receiver are orientedin such a way that they intersect at a predetermined measuring segment. The sensor can be setto give signal output at predetermined distance from the target. Theoretical studies have beencarried out to determine the minimum power required for transmitter with a trade-off between S/Nratio, aperture of receiver optics, reflectivity of target and range requirement. The scattered laserradiation from the target in this segment is utilised in deriving a signal output to detonate thebomb at a predetermined distance from the target. The laser proximity sensor has been developedfor 3 ± 0.5 m operational range and has qualified various environmental tests and live fuel-airexplosive bomb trials.

  7. A General Framework for Structured Sparsity via Proximal Optimization

    CERN Document Server

    Argyriou, Andreas; Morales, Jean; Pontil, Massimiliano

    2011-01-01

    We study a generalized framework for structured sparsity. It extends the well-known methods of Lasso and Group Lasso by incorporating additional constraints on the variables as part of a convex optimization problem. This framework provides a straightforward way of favouring prescribed sparsity patterns, such as orderings, contiguous regions and overlapping groups, among others. Existing optimization methods are limited to specific constraint sets and tend to not scale well with sample size and dimensionality. We propose a novel first order proximal method, which builds upon results on fixed points and successive approximations. The algorithm can be applied to a general class of conic and norm constraints sets and relies on a proximity operator subproblem which can be computed explicitly. Experiments on different regression problems demonstrate the efficiency of the optimization algorithm and its scalability with the size of the problem. They also demonstrate state of the art statistical performance, which imp...

  8. Analytical and Preliminary Simulation Study of a Pilot's Ability to Control the Terminal Phase of a Rendezvous with Simple Optical Devices and a Timer

    Science.gov (United States)

    Lineberry, Edgar C., Jr.; Brissenden, Roy F.; Kurbjun, Max C.

    1961-01-01

    One method of controlling the terminal phase of a space rendezvous between two vehicles is first to correct the flight path of the controlled vehicle so that a constant line of sight is established between the vehicles. This correction is accomplished by thrusting normal to the sight line in a direction to arrest the angular motion of this line. Once this collision course has been established, the second step is to control the closure rate for a safe approach along the line of sight. Adequate control of this maneuver requires range and closure-rate information. A combined analytical and preliminary simulation study was conducted to determine the ability of a human pilot to control the rendezvous by this method using visual sightings made during the initial collision-course control to obtain the range and closure rate. The analytical phase of the study reviewed the geometric relations between the vehicles and formed the basis for techniques to transform the angular sightings into range and closure rate. A preliminary simulation was then made to investigate the accuracy of these techniques. The simulation consisted of an analog computer, an oscilloscope to represent the view a pilot would have-with a stabilized sight, and a timer. Results indicate that pilots, using an optical sight and a timer, can successfully arrest the angular motion of the line of sight between two rendezvous vehicles and obtain relative range and closure rate with sufficient accuracy to perform the final braking maneuver successfully.

  9. Rendezvous of the "Third Kind": Triple Helix Origins and Future Possibilities

    Science.gov (United States)

    Etzkowitz, Henry

    2015-01-01

    The Triple Helix, representing university-industry-government interactions, was rooted in a 1993 International Workshop on University-Industry Relations at UNAM's Centro Para la Innovacion Technologica in Mexico City. Impelled by Mexican reality, where university-industry interactions and the institutions themselves operated within a governmental…

  10. Rendezvous of the "Third Kind": Triple Helix Origins and Future Possibilities

    Science.gov (United States)

    Etzkowitz, Henry

    2015-01-01

    The Triple Helix, representing university-industry-government interactions, was rooted in a 1993 International Workshop on University-Industry Relations at UNAM's Centro Para la Innovacion Technologica in Mexico City. Impelled by Mexican reality, where university-industry interactions and the institutions themselves operated within a governmental…

  11. The potential and prospects of proximal remote sensing of arthropod pests

    OpenAIRE

    Nansen, C

    2016-01-01

    Bench-top or proximal remote sensing applications are widely used as part of quality control and machine vision systems in commercial operations. In addition, these technologies are becoming increasingly important in insect systematics and studies of insect physiology and pest management. This paper provides a review and discussion of how proximal remote sensing may contribute valuable quantitative information regarding identification of species, assessment of insect responses to insecticides...

  12. A novel nonlinear control for tracking and rendezvous with a rotating non-cooperative target with translational maneuver

    Science.gov (United States)

    Zhang, Dayu; Luo, Jianjun; Gao, Dengwei; Ma, Weihua; Yuan, Jianping

    2017-09-01

    This paper studies the control of flexible chaser spacecraft to track and rendezvous with a rotating non-cooperative target accompanied by translational maneuver. The problem is formulated that the chaser spacecraft is required to track target position and be synchronized with its attitude precisely. Meanwhile, the elastic vibration, induced by large angular maneuver in the tracking process, needs to be reduced. With respect to this unique movement of target, a novel modified θ - D control method, derived by standard θ - D algorithm and Lyapunov min-max value theorem, is proposed to incorporate position, attitude and flexural motion into one united control frame. The modification term in the proposed control method is dealt with target translational maneuver, which is the primary contribution in this paper. The asymptotically stability of closed-loop system is proved via the Lyapunov theory and Lyapunov min-max value theorem. Numerical results demonstrate an excellent tracking performance of proposed united control frame even under large inertia uncertainties.

  13. Thermo-physical properties of 162173 (1999 JU3), a potential flyby and rendezvous target for interplanetary missions

    CERN Document Server

    Mueller, T G; Hasegawa, S; Abe, M; Kawakami, K; Kasuga, T; Kinoshita, D; Kuroda, D; Urakawa, S; Okumura, S; Sarugaku, Y; Miyasaka, S; Takagi, Y; Weissman, P R; Choi, Y -J; Larson, S; Yanagisawa, K; Nagayama, S

    2010-01-01

    Near-Earth asteroid 162173 (1999 JU3) is a potential flyby and rendezvous target for interplanetary missions because of its easy to reach orbit. The physical and thermal properties of the asteroid are relevant for establishing the scientific mission goals and also important in the context of near-Earth object studies in general. Our goal was to derive key physical parameters such as shape, spin-vector, size, geometric albedo, and surface properties of 162173 (1999 JU3). With three sets of published thermal observations (ground-based N-band, Akari IRC, Spitzer IRS), we applied a thermophysical model to derive the radiometric properties of the asteroid. The calculations were performed for the full range of possible shape and spin-vector solutions derived from the available sample of visual lightcurve observations. The near-Earth asteroid 162173 (1999 JU3) has an effective diameter of 0.87 +/- 0.03 km and a geometric albedo of 0.070 +/- 0.006. The chi2-test reveals a strong preference for a retrograde sense of r...

  14. Consensus based on learning game theory with a UAV rendezvous application

    Directory of Open Access Journals (Sweden)

    Lin Zhongjie

    2015-02-01

    Full Text Available Multi-agent cooperation problems are becoming more and more attractive in both civilian and military applications. In multi-agent cooperation problems, different network topologies will decide different manners of cooperation between agents. A centralized system will directly control the operation of each agent with information flow from a single centre, while in a distributed system, agents operate separately under certain communication protocols. In this paper, a systematic distributed optimization approach will be established based on a learning game algorithm. The convergence of the algorithm will be proven under the game theory framework. Two typical consensus problems will be analyzed with the proposed algorithm. The contributions of this work are threefold. First, the designed algorithm inherits the properties in learning game theory for problem simplification and proof of convergence. Second, the behaviour of learning endows the algorithm with robustness and autonomy. Third, with the proposed algorithm, the consensus problems will be analyzed from a novel perspective.

  15. Consensus based on learning game theory with a UAV rendezvous application

    Institute of Scientific and Technical Information of China (English)

    Lin Zhongjie; Liu Hugh hong-tao

    2015-01-01

    Multi-agent cooperation problems are becoming more and more attractive in both civil-ian and military applications. In multi-agent cooperation problems, different network topologies will decide different manners of cooperation between agents. A centralized system will directly control the operation of each agent with information flow from a single centre, while in a distrib-uted system, agents operate separately under certain communication protocols. In this paper, a sys-tematic distributed optimization approach will be established based on a learning game algorithm. The convergence of the algorithm will be proven under the game theory framework. Two typical consensus problems will be analyzed with the proposed algorithm. The contributions of this work are threefold. First, the designed algorithm inherits the properties in learning game theory for problem simplification and proof of convergence. Second, the behaviour of learning endows the algorithm with robustness and autonomy. Third, with the proposed algorithm, the consensus problems will be analyzed from a novel perspective.

  16. Promoting proximal formative assessment with relational discourse

    Science.gov (United States)

    Scherr, Rachel E.; Close, Hunter G.; McKagan, Sarah B.

    2012-02-01

    The practice of proximal formative assessment - the continual, responsive attention to students' developing understanding as it is expressed in real time - depends on students' sharing their ideas with instructors and on teachers' attending to them. Rogerian psychology presents an account of the conditions under which proximal formative assessment may be promoted or inhibited: (1) Normal classroom conditions, characterized by evaluation and attention to learning targets, may present threats to students' sense of their own competence and value, causing them to conceal their ideas and reducing the potential for proximal formative assessment. (2) In contrast, discourse patterns characterized by positive anticipation and attention to learner ideas increase the potential for proximal formative assessment and promote self-directed learning. We present an analysis methodology based on these principles and demonstrate its utility for understanding episodes of university physics instruction.

  17. 9__43 - 50__Tijjani_Proximate

    African Journals Online (AJOL)

    User

    standard analytical methods and parameters subjected to statistical analysis. Manganese (Mn), ..... promote microbial contamination and chemical degradation (Hussain et al., .... (2009): Proximate and qualitative analysis of different parts of ...

  18. PROXIMATE AND ELEMENTAL COMPOSITION OF WHITE GRUBS

    African Journals Online (AJOL)

    DR. AMINU

    1.23% (protein, lipids, carbohydrates and ash) and (moisture content) 34.01 ± 1.00%. The lipid and protein ... advised. Keywords: White grubs, Proximate Analysis, Essential element, Nutrient .... of important enzyme reactions: the oxidation of.

  19. Short Communication: Visual assessment, proximate composition ...

    African Journals Online (AJOL)

    Short Communication: Visual assessment, proximate composition and cost analysis of three ... Abstract. With increased search for least-cost alternative feed resource in animal ... In terms of odour, all three test mixtures were strongly pungent.

  20. comparative proximate composition and antioxidant vitamins ...

    African Journals Online (AJOL)

    DR. AMINU

    The proximate composition and antioxidant vitamins analysis of two varieties of honey (dark amber and light ... solution of inverted sugars and complex mixture of other saccharides .... Fonseca, R. M.O.,Alves, B. A. and Souza, L. C. (2009) ...

  1. Proximity and Collaboration in European Nanotechnology

    NARCIS (Netherlands)

    Cunningham, S.W.; Werker, C.

    2011-01-01

    Collaborations are particularly important for the development and deployment of technology. We analyze the influence of organizational, technological and geographical proximity on European nanotechnology collaborations with the help of a publication dataset and additional geographical information. W

  2. 无人机空中加油自主会合导引律研究%Study on guidance law for UAV autonomous rendezvous in aerial refueling

    Institute of Scientific and Technical Information of China (English)

    许萌; 杨朝星

    2014-01-01

    With the theory research of UAV autonomous guidance law for rendezvous in aerial refueling,the problem of homing guidance with impact final heading constraint is put forward.By redesigning the biased item in the 3D space and viewing the desired rendezvous point as the target and combing with pure tracking in the end of the guidance,the requirement for the terminal heading heading is achieved.Finllay,the guidance law given in the article is proved to be reasonable with a simulation example of air-tanker with constant speed and direction and with U motor,the UAV to select different initial position and heading.The simulation results show that the design of autonomous rendezvous guidance law is effective for UAV aerial refueling autonomous rendezvous, solves the existing class of autonomous rendezvous guidance law design complex, to be known in advance tankers trajectory and a large number of online programming calculation.%针对自主空中加油技术中的会和阶段的理论研究,提出一种带有终端偏航角约束的导引问题。通过对三维空间中重新设计偏置项,来同时约束俯仰与偏航角,将期望的会合点作为跟踪目标,并在制导末端结合纯追踪法,实现终端航向的控制。最后,以匀速直线运动和作U型机动的加油机为例,对无人机(UAV)选取不同的初始位置和航向来检验所提出的制导律实现会合的能力。仿真结果表明,所设计的自主会合制导律有效实现无人机空中加油自主会合,解决了现有一类自主会合制导律设计复杂、需预先已知加油机轨迹及大量在线规划计算的问题。

  3. Locking plates in proximal humerus fractures.

    Science.gov (United States)

    Strohm, P C; Helwig, P; Konrad, G; Südkamp, N P

    2007-12-01

    It is well known that proximal humerus fractures are among the three most frequent fracture types. Epidemiological invetsigations show that in people elder than 60 years the fracture of the proximal humerus is more frequent than fractures of the hip region (17). Over the last decades several techniques have been applied for treatment of proximal humerus fractures. Widely accepted is the initiation of a conservative treatment regimen for undisplaced fractures, however, the standard treatment for displaced fractures, especially three and four part fractures, is still the center of scientific debate. Many different implants have been tested and investigated, thus demonstrating lack of sufficient results. Over the last years the development of angle stable, locking implants started and clinical studies demonstrated encouraging results. In our clinic the locking proximal humerus plate and the PHILOS plate advanced to the implant of choice for treatment of displaced proximal humerus fractures. There are still cases of implant failure and humerus head necrosis, but most of these complications were caused by the fracture type and not an implant specific problem. However the overall results with these new implants are encouraging. Key words: locking plates, proximal humerus fracture, humerus, humerus fracture, PHILOS, PHP.

  4. Some Properties of Distances and Best Proximity Points of Cyclic Proximal Contractions in Metric Spaces

    Directory of Open Access Journals (Sweden)

    M. De La Sen

    2014-01-01

    Full Text Available This paper presents some results concerning the properties of distances and existence and uniqueness of best proximity points of p-cyclic proximal, weak proximal contractions, and some of their generalizations for the non-self-mapping T:⋃i∈p-Ai→⋃i∈p-Bi  (p≥2, where Ai and Bi, ∀i∈p-={1,2,…,p}, are nonempty subsets of X which satisfy TAi⊆Bi,∀i∈p-, such that (X,d is a metric space. The boundedness and the convergence of the sequences of distances in the domains and in their respective image sets of the cyclic proximal and weak cyclic proximal non-self-mapping, and of some of their generalizations are investigated. The existence and uniqueness of the best proximity points and the properties of convergence of the iterates to such points are also addressed.

  5. Shoulder hemiarthroplasty for the treatment of complex proximal humeral fractures

    Institute of Scientific and Technical Information of China (English)

    YANG Shu-hua; WANG Jing; XU Wei-hua; LI Jin; LIU Guo-hui; YANG Can; YE Shu-nan; YE Zhe-wei; LIU Yong

    2009-01-01

    Objective: To investigate the indication, perioperative announcements, selection of prosthesis and clinical results of shoulder hemiarthroplasty for the treatment of complex proximal humeral fractures.Methods: A total of 55 patients who suffered from com-plex proximal humeral fractures were treated by shoulder hemiarthroplasty. The mean age was 55.6 years and mean follow-up period was 25.1 months. The scoring system modi-fication for hemiarthroplasty (SSMH) had been adopted for evaluation at the latest follow-up.Results: The pain was obviously relieved in all patients. Fifty patients were painless and 5 patients had slight pain. The mean range of motion was 100°(90°-110°) in abduction, 95°(80°-100°) in forward flexion, 35°(30°-40°) in extemal rotation and internal rotation was confined at L2 level (L1-L3). The mean SSMH score was 27.9 (24-29). Fifty patients (90.1%) were satisfied with the clinical outcome.Conclusions: Shoulder hemiarthroplasty is an effective method to treat complex proximal humeral fractures. The proper selection of patients and prosthesis, good operation skill and enough functional exercise are the key points of successful treatment.

  6. SLAP tear associated with a minimally displaced proximal humerus fracture.

    Science.gov (United States)

    Kendall, Corey B; Tanner, Stephanie L; Tolan, Stefan J

    2007-12-01

    Nondisplaced proximal humerus fracture may be associated with soft tissue injury. This case report examines 2 cases of superior labral anterior-posterior (SLAP) tears in association with nondisplaced fractures of the proximal humerus. In the first case, the patient fell from a jet ski, causing a traction injury to his arm. A greater tuberosity fracture was identified. Magnetic resonance imaging (MRI) did not reveal a definitive labral tear. After conservative management had failed, a type IV SLAP tear and a small rotator cuff tear were arthroscopically identified and repaired. In the second case, a power company lineman fell from a lift and attempted to hold on with his dominant arm. A nondisplaced greater tuberosity and a surgical neck fracture were discovered. MR arthrography revealed no evidence of SLAP tear. Four months after injury, a type II SLAP tear was arthroscopically identified and repaired. In these 2 cases, the presence of the fracture likely slowed operative intervention because pain was attributed to the fracture itself, and not to the SLAP tear. If patients do not follow the usual course of improvement after a proximal humerus fracture from a superior traction mechanism, consideration should be given to associated superior labral tears that may require surgical intervention.

  7. Concomitant physeal fractures of the distal femur and proximal tibia

    Energy Technology Data Exchange (ETDEWEB)

    Sferopoulos, N.K. [Aristotle University of Thessaloniki, Department of Pediatric Orthopaedics, Thessaloniki (Greece)

    2005-07-01

    Concomitant physeal fractures of the distal femur and proximal tibia are very rare in children and adolescents. They are included in the classification of the ''floating knee'' injuries. Two cases with this combined injury are reported. They were closed injuries and in both patients the fracture of the proximal tibial epiphyseal plate was nondisplaced. In the first, a six-year-old girl, an early diagnosis was made radiographically. The intra-articular femoral fracture was operatively reduced and fixed. No growth abnormality was encountered 12 years later. The second patient, a 16-year-old boy, was conservatively treated for a displaced fracture-separation of the distal femoral epiphysis. Four weeks later there was physeal widening on both sides of the knee which indicated an associated fracture of the proximal tibial epiphyseal plate. One year after injury there was a varus deformity of the knee that was treated with a corrective osteotomy. Ten years later there is normal alignment of the leg. (orig.)

  8. Multiple intramedullary nailing of proximal phalangeal fractures of hand

    Directory of Open Access Journals (Sweden)

    Patankar Hemant

    2008-01-01

    Full Text Available Background: Proximal phalangeal fractures are commonly encountered fractures in the hand. Majority of them are stable and can be treated by non-operative means. However, unstable fractures i.e. those with shortening, displacement, angulation, rotational deformity or segmental fractures need surgical intervention. This prospective study was undertaken to evaluate the functional outcome after surgical stabilization of these fractures with joint-sparing multiple intramedullary nailing technique. Materials and Methods: Thirty-five patients with 35 isolated unstable proximal phalangeal shaft fractures of hand were managed by surgical stabilization with multiple intramedullary nailing technique. Fractures of the thumb were excluded. All the patients were followed up for a minimum of six months. They were assessed radiologically and clinically. The clinical evaluation was based on two criteria. 1. total active range of motion for digital functional assessment as suggested by the American Society for Surgery of Hand and 2. grip strength. Results: All the patients showed radiological union at six weeks. The overall results were excellent in all the patients. Adventitious bursitis was observed at the point of insertion of nails in one patient. Conclusion: Joint-sparing multiple intramedullary nailing of unstable proximal phalangeal fractures of hand provides satisfactory results with good functional outcome and fewer complications.

  9. Effect of angiotensin II receptor blockade on proximal tubular fluid reabsorption

    DEFF Research Database (Denmark)

    Leyssac, P P; Karlsen, F M; Holstein-Rathlou, N H

    1997-01-01

    to the macula densa will be compensated by an increase in the single-nephron glomerular filtration rate. In agreement with this, the early proximal flow rate, measured proximal to the site of losartan administration, increased by 5.7 +/- 1.3 nl/min. The increase in the rate of proximal reabsorption between...... convolution of halothane-anesthetized Sprague-Dawley rats. Four parameters that depend on the rate of proximal fluid reabsorption were measured: proximal intratubular pressure (Pprox), early and late proximal flow rate, and early distal NaCl concentration. Pprox decreased by 0.5 +/- 0.1 mmHg, late proximal...... flow rate decreased by 2.0 +/- 0.8 nl/min, and early distal NaCl concentration decreased by 4.3 +/- 0.8 mM (mean +/- SE). No changes were observed after microperfusion with saline. Because the tubuloglomerular feedback mechanism was operating in the closed-loop mode, the decreased NaCl load...

  10. Transverse Stress Fracture of the Proximal Patella: A Case Report.

    Science.gov (United States)

    Atsumi, Satoru; Arai, Yuji; Kato, Ko; Nishimura, Akinobu; Nakazora, Shigeto; Nakagawa, Shuji; Ikoma, Kazuya; Fujiwara, Hiroyoshi; Sudo, Akihiro; Kubo, Toshikazu

    2016-02-01

    Among stress fractures associated with sports activities, patellar stress fracture is rare. Regarding patella stress fractures, so far only distal transverse or lateral longitudinal fractures have been reported, but there are no reports of transverse fractures occurring in the proximal patella. We describe an extremely rare case of transverse stress fracture of proximal patella in a 9-year-old athlete.A 9-year old boy, who participated in sports (sprints and Kendo) presented with left knee pain without any external injury. In plain radiographs, a fracture line was observed in the proximal 1/3 of the left patella, and a patella stress fracture was diagnosed. For treatment, because 7 months of conservative therapy showed no improvement, internal fixation was carried out using Acutrak screws, and bone union was thus achieved. Three months after the operation, he was able to return to his previous level of athletic sports activity.Regarding the mechanism of onset, it is believed that the causes are longitudinal traction force and patellofemoral contact pressure. On the other hand, the contact region of the patella with the femur changes with the flexion angle of the knee. In the current case, the fracture occurred at a site where the patella was in contact with the femur at a flexion angle of >90°, so it is believed that it occurred as a clinical condition from being subjected to repeated longitudinal traction force and patellofemoral contact pressure at a flexion angle of >90°, during the sports activities of sprints and Kendo. The nonunion of the transverse stress fracture of his proximal patella was successfully treated with internal fixation using Acutrak screws.

  11. Groups as units of functional analysis, individuals as proximate mechanisms.

    Science.gov (United States)

    Wilson, David Sloan

    2014-06-01

    Whenever selection operates at a given level of a multitier hierarchy, units at that level should become the object of functional analysis, and units at lower levels should be studied as proximate mechanisms. This intuition already exists for the study of genes in individuals, when individuals are the unit of selection. It is only beginning to be applied for the study of individuals in groups, when groups are the unit of selection. Smaldino's target article is an important step in this direction with an emphasis on human cultural evolution, but the same algorithm applies to all multilevel evolutionary processes.

  12. Design of intelligent proximity detection zones to prevent striking and pinning fatalities around continuous mining machines

    Science.gov (United States)

    Bissert, P.T.; Carr, J.L.; DuCarme, J.P.; Smith, A.K.

    2017-01-01

    The continuous mining machine is a key piece of equipment used in underground coal mining operations. Over the past several decades these machines have been involved in a number of mine worker fatalities. Proximity detection systems have been developed to avert hazards associated with operating continuous mining machines. Incorporating intelligent design into proximity detection systems allows workers greater freedom to position themselves to see visual cues or avoid other hazards such as haulage equipment or unsupported roof or ribs. However, intelligent systems must be as safe as conventional proximity detection systems. An evaluation of the 39 fatal accidents for which the Mine Safety and Health Administration has published fatality investigation reports was conducted to determine whether the accident may have been prevented by conventional or intelligent proximity. Multiple zone configurations for the intelligent systems were studied to determine how system performance might be affected by the zone configuration. Researchers found that 32 of the 39 fatalities, or 82 percent, may have been prevented by both conventional and intelligent proximity systems. These results indicate that, by properly configuring the zones of an intelligent proximity detection system, equivalent protection to a conventional system is possible. PMID:28626352

  13. Locking plate fixation for proximal humerus fractures.

    LENUS (Irish Health Repository)

    Burke, Neil G

    2012-02-01

    Locking plates are increasingly used to surgically treat proximal humerus fractures. Knowledge of the bone quality of the proximal humerus is important. Studies have shown the medial and dorsal aspects of the proximal humeral head to have the highest bone strength, and this should be exploited by fixation techniques, particularly in elderly patients with osteoporosis. The goals of surgery for proximal humeral fractures should involve minimal soft tissue dissection and achieve anatomic reduction of the head complex with sufficient stability to allow for early shoulder mobilization. This article reviews various treatment options, in particular locking plate fixation. Locking plate fixation is associated with a high complication rate, such as avascular necrosis (7.9%), screw cutout (11.6%), and revision surgery (13.7%). These complications are frequently due to the varus deformation of the humeral head. Strategic screw placement in the humeral head would minimize the possibility of loss of fracture reduction and potential hardware complications. Locking plate fixation is a good surgical option for the management of proximal humerus fractures. Complications can be avoided by using better bone stock and by careful screw placement in the humeral head.

  14. Proximal sural traction neurectomy during transtibial amputations.

    Science.gov (United States)

    Tintle, Scott M; Donohue, Michael A; Shawen, Scott; Forsberg, Jonathan A; Potter, Benjamin K

    2012-02-01

    Symptomatic neuroma formation after trauma-related transtibial amputations remains a clinical problem. The sural nerve is frequently overlooked in its vulnerable subcutaneous location in the posterior myofasciocutaneous flap and commonly leads to chronic pain and decreased prosthesis use. The standard sural traction neurectomy may actually predispose the sural neuroma to form in a region that becomes symptomatic with prosthesis wear. The proposed modified proximal sural traction neurectomy using a standard or extended posterior flap begins with identification of the sural nerve in the subcutaneous tissue of the distal flap in identical fashion to a standard sural neurectomy. In the proximal posterior flap, a limited anterior approach is then performed and gentle traction on the distal end of the sural nerve aids in the identification of the most proximally accessible portion of the medial sural cutaneous nerve. After locating the medial sural cutaneous nerve proximally, a neurectomy at this location is performed, allowing the retraction of the nerve into a healthy tissue bed substantially more proximal than with a standard sural neurectomy. This technique ensures that the resulting neuroma does not form directly at the distal end of the residual limb where it is, in our experience, more likely to become symptomatic.

  15. CHEMICAL REACTIONS AS PETITE RENDEZVOUS: THE USE OF METAPHOR IN MATERIALS SCIENCE EDUCATION.

    Science.gov (United States)

    Uskoković, Vuk

    2014-04-01

    Every time we communicate our science, we are involuntarily involved in an educational activity, affecting the listeners' methodology and motivation. In a beautiful metaphor, late Nobel Laureate, Richard E. Smalley compared interacting atoms and molecules to boys and girls falling in love. Elaborated and exemplified with a couple of entertaining analogies in this discourse is the effectiveness of the use of metaphors in illustrating scientific concepts to both scientific novices and peers. Human brain has been considered to be a complex neural circuitry for the computation of metaphors, which explains the naturalness of their usage, especially when solid arguments could be given in support of the thesis that scientific imagery in general presents a collection of mathematically operable metaphors. On top of this, knowledge could be enriched through logic alone, but new concepts could be learned only through analogies. The greater pervasion of metaphors in scientific presentations could boost their inspirational potential, make the audience more attentive and receptive to their contents, and, finally, expand their educational prospect and enable their outreach to a far broader audience than it has been generally accomplished.

  16. Evaluation and Management of Proximal Humerus Fractures

    Directory of Open Access Journals (Sweden)

    Ekaterina Khmelnitskaya

    2012-01-01

    Full Text Available Proximal humerus fractures are common injuries, especially among older osteoporotic women. Restoration of function requires a thorough understanding of the neurovascular, musculotendinous, and bony anatomy. This paper addresses the relevant anatomy and highlights various management options, including indication for arthroplasty. In the vast majority of cases, proximal humerus fractures may be treated nonoperatively. In the case of displaced fractures, when surgical intervention may be pursued, numerous constructs have been investigated. Of these, the proximal humerus locking plate is the most widely used. Arthroplasty is generally reserved for comminuted 4-part fractures, head-split fractures, or fractures with significant underlying arthritic changes. Reverse total shoulder arthroplasty is reserved for patients with a deficient rotator cuff, or highly comminuted tuberosities.

  17. [Partial replantation following proximal limb injury].

    Science.gov (United States)

    Dubert, T; Malikov, S A; Dinh, A; Kupatadze, D D; Oberlin, C; Alnot, J Y; Nabokov, B B

    2000-11-01

    Proximal replantation is a technically feasible but life-threatening procedure. Indications must be restricted to patients in good condition with a good functional prognosis. The goal of replantation must be focused not only on reimplanting the amputated limb but also on achieving a good functional outcome. For the lower limb, simple terminalization remains the best choice in many cases. When a proximal amputation is not suitable for replantation, the main aim of the surgical procedure must be to reconstruct a stump long enough to permit fitting a prosthesis preserving the function of the adjacent joint. If the proximal stump beyond the last joint is very short, it may be possible to restore some length by partial replantation of spared tissues from the amputated part. We present here the results we obtained following this policy. This series included 16 cases of partial replantations, 14 involving the lower limb and 2 the upper limb. All were osteocutaneous microsurgical transfers. For the lower limb, all transfers recovered protective sensitivity following tibial nerve repair. The functional calcaeoplantar unit was used in 13 cases. The transfer of this specialized weight bearing tissue provided a stable distal surface making higher support unnecessary. In one case, we raised a 13-cm vascularized tibial segment covered with foot skin for additional length. For the upper limb, the osteocutaneous transfer, based on the radial artery, was not reinnervated, but this lack of sensitivity did not impair prosthesis fitting. One vascular failure was finally amputated. This was the only unsuccessful result. For all other patients, the surgical procedure facilitated prosthesis fitting and preserved the proximal joint function despite an initially very proximal amputation. The advantages of partial replantation are obvious compared with simple terminalization or secondary reconstruction. There is no secondary donor site and, because there is no major muscle mass in the

  18. The developmental spectrum of proximal radioulnar synostosis

    Energy Technology Data Exchange (ETDEWEB)

    Elliott, Alison M. [University of Manitoba, Winnipeg Regional Health Association Program of Genetics and Metabolism, Winnipeg, MB (Canada); University of Manitoba, Department of Paediatrics and Child Health, Winnipeg, MB (Canada); University of Manitoba, Department of Biochemistry and Medical Genetics, Winnipeg, MB (Canada); University of Manitoba, WRHA Program of Genetics and Metabolism, Departments of Paediatrics and Child Health, Biochemistry and Medical Genetics, Winnipeg, MB (Canada); Kibria, Lisa [University of Manitoba, Department of School of Medical Rehabilitation, Winnipeg, MB (Canada); Reed, Martin H. [University of Manitoba, Department of Paediatrics and Child Health, Winnipeg, MB (Canada); University of Manitoba, Department of Biochemistry and Medical Genetics, Winnipeg, MB (Canada); University of Manitoba, Department of Diagnostic Imaging, Winnipeg, MB (Canada)

    2010-01-15

    Proximal radioulnar synostosis is a rare upper limb malformation. The elbow is first identifiable at 35 days (after conception), at which stage the cartilaginous anlagen of the humerus, radius and ulna are continuous. Subsequently, longitudinal segmentation produces separation of the distal radius and ulna. However, temporarily, the proximal ends are united and continue to share a common perichondrium. We investigated the hypothesis that posterior congenital dislocation of the radial head and proximal radioulnar fusion are different clinical manifestations of the same primary developmental abnormality. Records were searched for ''proximal radioulnar fusion/posterior radial head dislocation'' in patients followed at the local Children's Hospital and Rehabilitation Centre for Children. Relevant radiographic, demographic and clinical data were recorded. Ethics approval was obtained through the University Research Ethics Board. In total, 28 patients met the inclusion criteria. The majority of patients (16) had bilateral involvement; eight with posterior dislocation of the radial head only; five had posterior radial head dislocation with radioulnar fusion and two had radioulnar fusion without dislocation. One patient had bilateral proximal radioulnar fusion and posterior dislocation of the left radial head. Nine patients had only left-sided involvement, and three had only right-sided involvement.The degree of proximal fusion varied, with some patients showing 'complete' proximal fusion and others showing fusion that occurred slightly distal to the radial head: 'partially separated.' Associated disorders in our cohort included Poland syndrome (two patients), Cornelia de Lange syndrome, chromosome anomalies (including tetrasomy X) and Cenani Lenz syndactyly. The suggestion of a developmental relationship between posterior dislocation of the radial head and proximal radioulnar fusion is supported by the fact that both anomalies

  19. Infrared-Proximity-Sensor Modules For Robot

    Science.gov (United States)

    Parton, William; Wegerif, Daniel; Rosinski, Douglas

    1995-01-01

    Collision-avoidance system for articulated robot manipulators uses infrared proximity sensors grouped together in array of sensor modules. Sensor modules, called "sensorCells," distributed processing board-level products for acquiring data from proximity-sensors strategically mounted on robot manipulators. Each sensorCell self-contained and consists of multiple sensing elements, discrete electronics, microcontroller and communications components. Modules connected to central control computer by redundant serial digital communication subsystem including both serial and a multi-drop bus. Detects objects made of various materials at distance of up to 50 cm. For some materials, such as thermal protection system tiles, detection range reduced to approximately 20 cm.

  20. Proximal interphalangeal arthrodesis in 22 horses.

    Science.gov (United States)

    Schaer, T P; Bramlage, L R; Embertson, R M; Hance, S

    2001-07-01

    The purpose of this study was to evaluate a new method of internal fixation technique for pastern arthrodesis. Pastern arthrodeses are performed commonly in horses with chronic osteoarthritis of the pastern joint or, in cases of acute traumatic injury to the pastern, in which the weightbearing bony column must be restored. Chronic osteoarthritis of the pastern is a frequent cause of lameness in the equine athlete and is evidenced by chronic lameness localised to the pastern joint, and supported radiographically by periosteal proliferation and loss of joint space. Nonsurgical and surgical treatments have both been described in the literature. Complications following pastern arthrodesis have been reported on several occasions and appear to focus on excessive periarticular exostoses and increased time in a cast due to prolonged time to bony fusion. The hospital records of horses presenting for pastern arthrodesis to the Rood and Riddle Equine Hospital in Lexington, Kentucky, were reviewed and 22 met criteria for inclusion in the study. Horses with chronic osteoarthritis of the proximal interphalangeal joint or horses with an acute traumatic injury to the pastern undergoing pastern arthrodesis with one of the following techniques were included in the study. Horses with severe comminution of the middle phalanx were excluded. Three 5.5 mm cortical bone screws placed in lag fashion alone or in combination with a 4 or 3 hole dynamic compression plate affixed with 4.5 mm cortical bone screws were compared. A lower limb fibreglass cast was applied in all cases. Period in cast, time to return to intended use, complications encountered and outcome were evaluated. Seven of the 8 hindlimbs treated with the combination technique became sound. Three out of 6 of the front limbs treated with the combination technique became sound. Four of the 5 horses with hindlimbs, and one of the 2 with front limbs, treated with screws only returned to their intended use. The type of internal

  1. Restoring proximal caries lesions conservatively with tunnel restorations

    Directory of Open Access Journals (Sweden)

    Chu CH

    2013-07-01

    Full Text Available Chun-Hung Chu1, May L Mei,1 Chloe Cheung,1 Romesh P Nalliah2 1Faculty of Dentistry, The University of Hong Kong, Hong Kong, People's Republic of China; 2Department of Restorative Dentistry and Biomaterials Sciences, Harvard School of Dental Medicine, Boston, MA, USA Abstract: The tunnel restoration has been suggested as a conservative alternative to the conventional box preparation for treating proximal caries. The main advantage of tunnel restoration over the conventional box or slot preparation includes being more conservative and increasing tooth integrity and strength by preserving the marginal ridge. However, tunnel restoration is technique-sensitive and can be particularly challenging for inexperienced restorative dentists. Recent advances in technology, such as the contemporary design of dental handpieces with advanced light-emitting diode (LED and handheld comfort, offer operative dentists better vision, illumination, and maneuverability. The use of magnifying loupes also enhances the visibility of the preparation. The advent of digital radiographic imaging has improved dental imaging and reduced radiation. The new generation of restorative materials has improved mechanical properties. Tunnel restoration can be an option to restore proximal caries if the dentist performs proper case selection and pays attention to the details of the restorative procedures. This paper describes the clinical technique of tunnel restoration and reviews the studies of tunnel restorations. Keywords: operative, practice, tunnel preparation, composite, amalgam, glass ionomer

  2. The Zone of Proximal "Teacher" Development

    Science.gov (United States)

    Warford, Mark K.

    2011-01-01

    Toward the end of his short life, Lev Vygotsky found himself teaching teachers in a remote part of the USSR. Though his influence as a developmental psychologist is well-established, little is known about his approach to teacher development. This article applies the researcher's core concept, the zone of proximal development to teacher education.…

  3. Secluded and Proximate Illiteracy: Comparing Situations

    Science.gov (United States)

    Mishra, Srijit

    2005-01-01

    Triplot is used to portray the three-dimensional concepts--literate, proximate illiterate and secluded illiterate. Pictographic portrayal complemented with a method proposed to calculate distance between situations enhances comparison. Illustration with Indian data explains change over time, rural-urban divide, and social gap.

  4. The Life Saving Effects of Hospital Proximity

    DEFF Research Database (Denmark)

    Bertoli, Paola; Grembi, Veronica

    the exogenous variation in the proximity to cities that are allowed by law to have a hospital based on their population size. Our instrumental variable results, based on Italian municipalities data from 2000 to 2012, show that an increase by a standard deviation of distance to the nearest hospital (5 km...

  5. Infiltrating/sealing proximal caries lesions

    DEFF Research Database (Denmark)

    Martignon, S; Ekstrand, K R; Gomez, J

    2012-01-01

    proximal lesions identified radiographically around the enamel-dentin junction to the outer third of the dentin, were included. Lesions were randomly allocated for treatment to test-A (Infiltration: ICON-pre-product; DMG), test-B (Sealing: Prime-Bond-NT; Dentsply), or control-C (Placebo). Primary outcome...

  6. Thermogravimetry speeds up proximate analysis of coal

    Energy Technology Data Exchange (ETDEWEB)

    Baur, P.

    1983-03-01

    Thermogravimetric analysis is not an ASTM standard method for proximate analysis of coal and coke, but it is widely used in US laboratories because of its speed, accuracy and flexibility. Equipment available from different manufacturers is compared and the experience of a number of users is recounted.

  7. Controllable proximity effect in superconducting hybrid devices

    NARCIS (Netherlands)

    Bakurskiy, Sergey

    2015-01-01

    This thesis is devoted to the study of controllable proximity effects in superconductors, both in terms of fundamental aspects and applications. As a part of this thesis theoretical description was suggested for a number of structures with superconducting electrodes and multiple interlayers. These s

  8. Proximate, chemical compositions and sulphur concentrations on ...

    African Journals Online (AJOL)

    aghomotsegin

    2013-05-08

    May 8, 2013 ... 1Department of Agriculture, Animal Health and Human Ecology, ... quadratic effect on mango pulp proximate concentration and ..... and then the equal volumes of the two were mixed. ... General linear model (GLM) procedure of SAS version 8.0 (SAS .... Berardini N, Knodler M, Schieber A, Carle R (2005).

  9. Large proximal ureteral stones: Ideal treatment modality?

    Directory of Open Access Journals (Sweden)

    B Kadyan

    2016-01-01

    Conclusion: Laparoscopic transperitoneal ureterolithotomy is a minimally invasive, safe and effective treatment modality and should be recommended to all patients of impacted large proximal stones, which are not amenable to URS or extracorporeal shock-wave lithotripsy or as a primary modality of choice especially if patient is otherwise candidate for open surgery.

  10. Proximity Graphs for Crowd Movement Sensors

    NARCIS (Netherlands)

    Chilipirea, Cristian; Petre, Andreea-Cristina; Dobre, Ciprian; Steen, van Maarten

    2015-01-01

    Sensors are now common, they span over different applications, different purposes and some over large geospatial areas. Most data produced by these sensors needs to be linked to the physical location of the sensor itself. By using the location of a sensor we can construct (mathematically) proximity

  11. Goal-Proximity Decision-Making

    Science.gov (United States)

    Veksler, Vladislav D.; Gray, Wayne D.; Schoelles, Michael J.

    2013-01-01

    Reinforcement learning (RL) models of decision-making cannot account for human decisions in the absence of prior reward or punishment. We propose a mechanism for choosing among available options based on goal-option association strengths, where association strengths between objects represent previously experienced object proximity. The proposed…

  12. Modified esophagogastrostomy in laparoscopy-assisted proximal gastrectomy: A reverse-Tornado anastomosis.

    Science.gov (United States)

    Kubota, Keisuke; Suzuki, Akihiro; Fujikawa, Aoi; Watanabe, Takayuki; Sekido, Yuki; Shiozaki, Hironori; Taketa, Takashi; Shimada, Gen; Ohigashi, Seiji; Sakurai, Shintaro; Kishida, Akihiro

    2017-02-01

    The aim of this study was to introduce and examine a modified mechanical end-to-side esophagogastrostomy method ("reverse-Tornado" anastomosis) in laparoscopy-assisted proximal gastrectomy. Five patients with gastric cancer who underwent laparoscopy-assisted proximal gastrectomy were analyzed retrospectively. Esophagogastrostomy in the anterior wall was performed in three patients, and esophagogastrostomy in the posterior wall was performed in two patients. Clinicopathological features, operative outcomes (operative time, operative blood loss), and postoperative outcomes (complications, postoperative hospital stay, reflux esophagitis) were evaluated. Operative time was normal (278 min). There was no marked operative blood loss, postoperative complications, prolonged hospital stay, or reflux esophagitis. Esophagogastrostomy was completed in a normal time with reverse-Tornado anastomosis. This method can be safe and can enable good postoperative quality of life. © 2016 Japan Society for Endoscopic Surgery, Asia Endosurgery Task Force and John Wiley & Sons Australia, Ltd.

  13. Proximal Contact Repair of Complex Amalgam Restorations.

    Science.gov (United States)

    Zguri, M N; Casey, J A; Jessup, J P; Vandewalle, K S

    2017-01-12

    The carving of a complex amalgam restoration may occasionally result in light proximal contact with the adjacent tooth. The purpose of this study was to investigate the strength of complex amalgam restorations repaired with a proximal slot amalgam preparation. Extracted human third molars of similar coronal size were sectioned 1 mm apical to the height of the contour using a saw and were randomly distributed into 9 groups of 10 teeth each. One pin was placed at each line angle of the flattened dentinal tooth surface. A metal matrix band was placed and an admixed alloy was condensed and carved to create a full crown contour but with a flat occlusal surface. A proximal slot was prepared with or without a retention groove and repaired using a single-composition spherical amalgam 15 minutes, 24 hours, one week, or six months after the initial crown condensation. The specimens were stored for 24 hours in 37°C water before fracture at the marginal ridge using a round-ended blade in a universal testing machine. The control group was not repaired. The mean maximum force in newtons and standard deviation were determined per group. Data were analyzed with a 2-way analysis of variance as well as Tukey and Dunnett tests (α=0.05). Significant differences were found between groups based on type of slot preparation (p=0.017) but not on time (p=0.327), with no significant interaction (p=0.152). No significant difference in the strength of the marginal ridge was found between any repair group and the unrepaired control group (p>0.076). The proximal repair strength of a complex amalgam restoration was not significantly different from an unrepaired amalgam crown. Placing a retention groove in the proximal slot preparation resulted in significantly greater fracture strength than a slot with no retention grooves. Time of repair had no significant effect on the strength of the repair.

  14. Trojan Tour and Rendezvous (TTR): A New Frontiers Mission to Explore the Origin and Evolution of the Early Solar System

    Science.gov (United States)

    Bell, J. F., III; Olkin, C.; Castillo, J. C.

    2015-12-01

    The orbital properties, compositions, and physical properties of the diverse populations of small outer solar system bodies provide a forensic map of how our solar system formed and evolved. Perhaps the most potentially diagnostic, but least explored, of those populations are the Jupiter Trojan asteroids, which orbit at ~5 AU in the L4 and L5 Lagrange points of Jupiter. More than 6200 Jupiter Trojans are presently known, but these are predicted to be only a small fraction of the 500,000 to 1 million Trojans >1 km in size. The Trojans are hypothesized to be either former Kuiper Belt Objects (KBOs) that were scattered into the inner solar system by early giant planet migration and then trapped in the 1:1 Jupiter mean motion resonance, or bodies formed near 5 AU in a much more quiescent early solar system, and then trapped at L4 and L5. The 2011 Planetary Science Decadal Survey identified important questions about the origin and evolution of the solar system that can be addressed by studying of the Trojan asteroids, including: (a) How did the giant planets and their satellite systems accrete, and is there evidence that they migrated to new orbital positions? (b) What is the relationship between large and small KBOs? Is the small population derived by impact disruption of the large one? (c) What kinds of surface evolution, radiation chemistry, and surface-atmosphere interactions occur on distant icy primitive bodies? And (d) What are the sources of asteroid groups (Trojans and Centaurs) that remain to be explored by spacecraft? The Trojan Tour and Rendezvous (TTR) is a New Frontiers-class mission designed to answer these questions, and to test hypotheses for early giant planet migration and solar system evolution. Via close flybys of a large number of these objects,, and orbital characterization of at least one large Trojan, TTR will enable the first-time exploration of this population. Our primary mission goals are to characterize the overall surface geology

  15. The effect of wall proximity on energy harvesting using a pitching and heaving hydrofoil

    Science.gov (United States)

    Su, Yunxing; Miller, Michael; Mandre, Shreyas; Breuer, Kenneth

    2015-11-01

    Measurements of energy harvesting using a heaving and pitching hydrofoil with an aspect ratio 4.5 were taken in three different situations: unconfined, in close proximity to one wall and in close proximity to two walls. Measured lift and torque forces were used with the hydrofoil positions to calculate the efficiency of energy extracted from the flow. There was a modest increase in efficiency with one-wall proximity, while a pronounced increase in efficiency (up to 50%) was realized when the hydrofoil operated between two walls with strong confinement. The lift coefficient of the hydrofoil experienced a noticeable increase in two-wall proximity cases with the strong confinement, which directly contributed to the increase in efficiency of energy harvesting. In the case of two-wall confinement, we found that the optimal frequency and pitch amplitude were higher than those for both the free stream and the one-wall proximity cases. The power extracted from the heaving motion was greatly enhanced by two-wall proximity at high frequencies and high pitch amplitudes and these gains exceeded the additional power required to execute the pitching motion, resulting in the net increase in energy harvesting effectiveness. ARPA-e.

  16. Single Balloon Enteroscopy-Assisted ERCP Using Rendezvous Technique for Sharp Angulation of Roux-en-Y Limb in a Patient with Bile Duct Stones

    Directory of Open Access Journals (Sweden)

    Takao Itoi

    2009-01-01

    Full Text Available The acute angulation of Roux-en-Y (R-Y limb precludes endoscopic access for endoscopic retrograde cholangiopancreatography (ERCP even using a balloon enteroscopy. Here, we describe a case of successful single balloon enteroscopy (SBE-assisted ERCP using a rendezvous technique in a patient with sharply angulated R-Y limb in a 79-year-old woman who had bile duct stones. Method. At first, a guidewire was passed antegradely through the major papilla after the needle puncture using percutaneous transhepatic biliary drainage technique. A hydrophilic guidewire with an ERCP catheter was antegradely advanced beyond the Roux limb. After a guidewire was firmly grasped by a snare forceps, it was pulled out of the body, resulting that the enteroscope could advance to the papilla. After papillary dilation, complete removal of bile duct stones was achieved without any procedure-related complication. In conclusion, although further study is needed, SBE-assisted ERCP using a rendezvous technique may have a potential for selected patients.

  17. Between Les Rendez-vous d’Anna and Demain on Déménage: m(other inscriptions in two films by Chantal Akerman

    Directory of Open Access Journals (Sweden)

    Alison Rowley

    2010-01-01

    Full Text Available 'Demain on Déménage' is a gloriously comic queering of reproduction that claims as its foundation heterosexual sexuality and the stability of the hetero-normative unit of the couple. Akerman's decision to cast Aurore Clément in the role of a mother in 'Demain on Déménage', over two decades after playing a daughter in 'Les Rendez-vous d'Anna', encourages a reading of the 2005 film as a reprise of concerns first explored in 1978. If 'Les Rendez-vous d'Anna' has moments in common with Lee Edelman's uncompromisingly provocative polemic against the ideology of 'reproductive futurism', this paper argues that 'Demain on Déménage' figures the 'matrixial' movement Bracha Ettinger theorises as opening on to a different concept of futurity, symbolised not in post-natal terms by the child or the mother, but rather as a corporeal- psychic imprint of the 'originary prenatal encounter event, with-in pregnancy' common to all human beings, which offers another model of communal relations.

  18. Functional outcome following proximal humeral interlocking system plating for displaced proximal humeral fractures

    Directory of Open Access Journals (Sweden)

    Thyagarajan David

    2009-01-01

    Full Text Available Aim: To assess the functional outcome following internal fixation with the PHILOS (proximal humeral interlocking system for displaced proximal humeral fractures. Patients and Methods: We reviewed 30 consecutive patients treated surgically with the proximal humeral locking plate for a displaced proximal humeral fracture. Functional outcome was determined using the American Shoulder and Elbow Society (ASES score and Constant Murley score. Results: Average age of the patients was 58 years (range, 19-92 years. The average overall ASES score was 66.5. The average overall Constant score was 57.5. Conclusion: Our results show that good fracture stability was achieved, and the functional outcome was very good in younger patients and it declined with increasing age. Early mobilization of the shoulder can be achieved without compromising fracture union.

  19. Arthroplasty treatment of proximal humerus fractures: 14-year trends in the United States.

    Science.gov (United States)

    Schairer, William W; Nwachukwu, Benedict U; Lyman, Stephen; Gulotta, Lawrence V

    2017-05-01

    Proximal humerus fractures are a common injury in the elderly population that can usually be managed non-operatively. However, arthroplasty has become increasingly utilized for complex fractures and poor bone quality. We evaluated national trends in treatment, specifically looking at the adoption of reverse total shoulder arthroplasty. The incidence of proximal humerus fractures was calculated from the Nationwide Emergency Department Database (NEDD) from 2006 to 2012. The Nationwide Inpatient Sample (NIS) was used to select patients from 2000 to 2013 with proximal humerus fractures treated with open reduction and internal fixation (ORIF), total shoulder arthroplasty (TSA), reverse total shoulder arthroplasty (RSA), and hemiarthroplasty (HSA). RSA and TSA shared the same ICD-9 code until 2010. The incidence of proximal humerus fracture was stable from 2006 to 2012. Hemiarthroplasty was the majority treatment choice for arthroplasty in the early 2000's. However, in 2008, there was a large decrease in utilization, to 51.3% in 2013. During this period, utilization of TSA greatly increased, coinciding with a large increase of RSA. By 2013, RSA made up 45.1% of arthroplasty procedures. The rate of proximal humerus fracture appears stable, while we observed both an overall increase in operative intervention. RSA appears to be increasingly chosen over HSA for arthroplasty treatment of proximal humerus fractures, an observation more pronounced in older patients. While clinical results appear promising, it is important to remember that most proximal humerus fractures may be treated successfully with conservative management, and rapid adoption of new technology should be watched carefully to ensure appropriate use.

  20. Proximal tubular hypertrophy and enlarged glomerular and proximal tubular urinary space in obese subjects with proteinuria.

    Directory of Open Access Journals (Sweden)

    Ana Tobar

    Full Text Available BACKGROUND: Obesity is associated with glomerular hyperfiltration, increased proximal tubular sodium reabsorption, glomerular enlargement and renal hypertrophy. A single experimental study reported an increased glomerular urinary space in obese dogs. Whether proximal tubular volume is increased in obese subjects and whether their glomerular and tubular urinary spaces are enlarged is unknown. OBJECTIVE: To determine whether proximal tubules and glomerular and tubular urinary space are enlarged in obese subjects with proteinuria and glomerular hyperfiltration. METHODS: Kidney biopsies from 11 non-diabetic obese with proteinuria and 14 non-diabetic lean patients with a creatinine clearance above 50 ml/min and with mild or no interstitial fibrosis were retrospectively analyzed using morphometric methods. The cross-sectional area of the proximal tubular epithelium and lumen, the volume of the glomerular tuft and of Bowman's space and the nuclei number per tubular profile were estimated. RESULTS: Creatinine clearance was higher in the obese than in the lean group (P=0.03. Proteinuria was similarly increased in both groups. Compared to the lean group, the obese group displayed a 104% higher glomerular tuft volume (P=0.001, a 94% higher Bowman's space volume (P=0.003, a 33% higher cross-sectional area of the proximal tubular epithelium (P=0.02 and a 54% higher cross-sectional area of the proximal tubular lumen (P=0.01. The nuclei number per proximal tubular profile was similar in both groups, suggesting that the increase in tubular volume is due to hypertrophy and not to hyperplasia. CONCLUSIONS: Obesity-related glomerular hyperfiltration is associated with proximal tubular epithelial hypertrophy and increased glomerular and tubular urinary space volume in subjects with proteinuria. The expanded glomerular and urinary space is probably a direct consequence of glomerular hyperfiltration. These effects may be involved in the pathogenesis of obesity

  1. The quantitative role of flexor sheath incision in correcting Dupuytren proximal interphalangeal joint contractures.

    Science.gov (United States)

    Blazar, P E; Floyd, E W; Earp, B E

    2016-07-01

    Controversy exists regarding intra-operative treatment of residual proximal interphalangeal joint contractures after Dupuytren's fasciectomy. We test the hypothesis that a simple release of the digital flexor sheath can correct residual fixed flexion contracture after subtotal fasciectomy. We prospectively enrolled 19 patients (22 digits) with Dupuytren's contracture of the proximal interphalangeal joint. The average pre-operative extension deficit of the proximal interphalangeal joints was 58° (range 30-90). The flexion contracture of the joint was corrected to an average of 28° after fasciectomy. In most digits (20 of 21), subsequent incision of the flexor sheath further corrected the contracture by an average of 23°, resulting in correction to an average flexion contracture of 4.7° (range 0-40). Our results support that contracture of the tendon sheath is a contributor to Dupuytren's contracture of the joint and that sheath release is a simple, low morbidity addition to correct Dupuytren's contractures of the proximal interphalangeal joint. Additional release of the proximal interphalangeal joint after fasciectomy, after release of the flexor sheath, is not necessary in many patients. IV (Case Series, Therapeutic). © The Author(s) 2015.

  2. Millennials: Rendezvous with Destiny?

    Science.gov (United States)

    2008-03-05

    Millennial political tendencies. Regarding politics , the article states that Civic generations (G.I./ Millennial ) show a tendency to react against Idealist...Globalization, Future Trends CLASSIFICATION: Unclassified The Millennial Generation (born between 1982 and about 2002) is showing characteristics...tenacious execution across multiple disciplines. This paper provides a generational profile of the Millennials and examines where this current

  3. DARe: Dark Asteroid Rendezvous

    Science.gov (United States)

    Noll, K. S.; McFadden, L. A.; Rhoden, A. R.; Lim, L. F.; Boynton, W. V.; Carter, L. M.; Collins, G.; Englander, J. A.; Goossens, S. A.; Grundy, W. M.; Li, J.-Y.; Mottola, S.; Oberst, J.; Orosei, R.; Parsons, A. M.; Preusker, F.; Reuter, D. C.; Simon, A. A.; Thomas, C. A.; Walsh, K.; Zolensky, M. E.

    2015-01-01

    Small bodies record the chemical, physical, and dynamical processes that gave birth to and shaped the solar system. The great variety of small bodies reflects the diversity of both their genesis and their histories. The DARe mission conducts a critical test of how small body populations reflect a history of planetary migration and planetesimal scattering. This understanding is crucial for planning future NASA missions and placing current and past missions into context.

  4. Total hip arthroplasty following failed fixation of proximal hip fractures

    Directory of Open Access Journals (Sweden)

    Srivastav Shekhar

    2008-01-01

    Full Text Available Background: Most proximal femoral fractures are successfully treated with internal fixation but a failed surgery can be very distressing for the patient due to pain and disability. For the treating surgeon it can be a challenge to perform salvage operations. The purpose of this study was to evaluate the short-term functional outcome and complications of total hip arthroplasty (THA following failed fixation of proximal hip fracture. Materials and Methods: In a retrospective study, 21 hips in 20 patients (13 females and seven males with complications of operated hip fractures as indicated by either established nonunion or fracture collapse with hardware failure were analysed. Mean age of the patients was 62 years (range 38 years to 85 years. Nine patients were treated for femoral neck fracture, 10 for intertrochanteric (I/T fracture and two for subtrochanteric (S/T fracture of the hip. Uncemented THA was done in 11 cases, cemented THA in eight hip joints and hybrid THA in two patients. Results: The average duration of follow-up was four years (2-13 years. The mean duration of surgery was 125 min and blood loss was 1300 ml. There were three dislocations postoperatively. Two were managed conservatively and one was operated. There was one superficial infection and one deep infection. Only one patient required a walker while four required walking stick for ambulation. The mean Harris Hip score increased from 32 preoperatively to 79 postoperatively at one year interval. Conclusion: Total hip arthroplasty is an effective salvage procedure after failed osteosynthesis of hip fractures. Most patients have good pain relief and functional improvements inspite of technical difficulties and high complication rates than primary arthroplasty.

  5. Obstructive Colitis Proximal to Obstructive Colorectal Carcinoma

    Directory of Open Access Journals (Sweden)

    Hye Kyung Chang

    2009-01-01

    Full Text Available The term “obstructive colitis” refers to ulceroinflammatory lesions occurring in the colon proximal to a completely or partially obstructing lesion. It has been referred to by various terms in the literature. This entity differs from the carcinoma of the colon that complicates true ulcerative colitis where there is involvement distal to the neoplasm as well as proximal to it. Although it has appeared in the literature over several decades, it remains an uncommon and troublesome disease. In Yonsei University Medical Center, for 11 years from January 1996 to December 2006 we encountered seven patients with obstructing colorectal carcinoma complicated by obstructive colitis. Here we report our cases to share our experience and to review the literature to facilitate the recognition and proper management of this rare disease entity.

  6. The Life Saving Effects of Hospital Proximity

    DEFF Research Database (Denmark)

    Bertoli, Paola; Grembi, Veronica

    We assess the lifesaving effect of hospital proximity using data on fatality rates of road-traffic accidents. While most of the literature on this topic is based on changes in distance to the nearest hospital triggered by hospital closures and use OLS estimates, our identification comes from the ...... more when the road safety is low; the emergency service is not properly organized, and the nearest hospital has lower quality standards.......We assess the lifesaving effect of hospital proximity using data on fatality rates of road-traffic accidents. While most of the literature on this topic is based on changes in distance to the nearest hospital triggered by hospital closures and use OLS estimates, our identification comes from...

  7. Correlation between social proximity and mobility similarity

    CERN Document Server

    Fan, Chao; Huang, Junming; Rong, Zhihai; Zhou, Tao

    2016-01-01

    Human behaviors exhibit ubiquitous correlations in many aspects, such as individual and collective levels, temporal and spatial dimensions, content, social and geographical layers. With rich Internet data of online behaviors becoming available, it attracts academic interests to explore human mobility similarity from the perspective of social network proximity. Existent analysis shows a strong correlation between online social proximity and offline mobility similari- ty, namely, mobile records between friends are significantly more similar than between strangers, and those between friends with common neighbors are even more similar. We argue the importance of the number and diversity of com- mon friends, with a counter intuitive finding that the number of common friends has no positive impact on mobility similarity while the diversity plays a key role, disagreeing with previous studies. Our analysis provides a novel view for better understanding the coupling between human online and offline behaviors, and will...

  8. Juvenile xanthogranuloma of the proximal nail fold.

    Science.gov (United States)

    Piraccini, Bianca Maria; Fanti, Pier Alessandro; Iorizzo, Matilde; Tosti, Antonella

    2003-01-01

    An 18-month-old Caucasian boy presented with a firm 0.5 mm nodule, pink-red in color, with a yellow hue and some telangiectases on the surface, localized on the right thumbnail. The nodule involved all of the proximal nail fold and covered the proximal third of the nail. Pathology showed a dense dermal infiltrate of histiocytes, some of which had foamy nuclei, and multinucleated Touton giant cells. The lesion progressively decreased in size and had completely disappeared after 3 years. Periodic follow-up was important not only to monitor evolution of the juvenile xanthogranuloma, but also to avoid excessive growth of the lesion with possible definitive nail matrix damage.

  9. Children’s proximal societal conditions

    DEFF Research Database (Denmark)

    Stanek, Anja Hvidtfeldt

    ) the children’s proximal societal conditions for development and learning, means for instance that considerations about an inclusive agenda in a (Danish) welfare state with well-developed school- and daycare system, are no longer simply thoughts about the school having space for as many pupils as possible...... the conceptualization of children’s “proximal societal conditions”. Throughout different research projects in which children’s everyday life in different daycare settings and in schools has been studied, it becomes clear that ‘the societal’ is not something that is above or outside the institutional setting...... or the children’s everyday life, but something that is represented through societal structures and actual persons participating (in political ways) within the institutional settings, in ways that has meaning to children’s possibilities to participate, learn and develop. Understanding school or daycare as (part of...

  10. Proximate determinants of fertility in Taiwan area.

    Science.gov (United States)

    Lo, S R; Chen, C H

    1987-06-01

    To establish base line data and to evaluate the impacts of induced abortion on fertility in Taiwan before and after legalization, and induced abortion prevalence survey was conducted. 12,516 samples of married women age 15-49 were covered to represent all of Taiwan. Bongaarts' model of proximate determinants of fertility is applied to the survey data to analyze the relationships among total fertility rate, total fecundity, and the indices of the proximate determinants on nonmarriage, contraception, induced abortion, and lacatation. The index of contraception appears to have the greatest (47%) effect on the recent decline of total fertility rate (TFR). Contraception also has the greatest effect on fertility decline among different urbanization areas: 45% for large cities; 46% for urbantownships; and 50% for rural areas. The effects of the proportion of married on the fertility of the 3 areas are 45%, 40%, and 40%, respectively. For induced abortion, the effect is 13% in urban townships and 11% in large cities.

  11. Tunable Magnetic Proximity Effects in Graphene Junctions

    Science.gov (United States)

    Lazic, Predrag; Belashchenko, Kirill; Zutic, Igor

    2015-03-01

    The characteristic length of the magnetic proximity effects exceed the thickness of a graphene layer leading to an important, but typically overlooked, modifications of equilibrium and transport properties, as well as the implications for graphene spintronics. Using the first-principles studies that integrate a real space density functional theory (GPAW) with the state-of-the art boundary elements electrostatic code based on the Robin Hood method, we explore tunable electronic structure and magnetic proximity effects in the ferromagnet/insulator/graphene junctions. We show that the inclusion of a finite-size gate electrodes and van der Walls interaction lead to nontrivial effects that could also be important in other two-dimensional materials beyond graphene. Work supported by US ONR, NSF-DMR and Nebraska NSF MRSEC.

  12. [Proximity and breastfeeding at the maternity hospital].

    Science.gov (United States)

    Fradin-Charrier, Anne-Claire

    2015-01-01

    The establishment of breastfeeding, as well as its duration, are facilitated through the proximity of the mother with her new baby. However, in maternity hospitals, breastfeeding mothers very often leave their baby in the nursery at night time. A study carried out in 2014 in several maternity hospitals put forward suggestions and highlighted areas to improve in everyday practice. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  13. Proximal humeral fractures treated with arthroplasty

    Institute of Scientific and Technical Information of China (English)

    QIAN Qi-rong; WU Hai-shan; ZHOU Wei-jiang; LI Xiao-hua; WU Yu-li

    2005-01-01

    Objective: To explore arthroplasty in treating 3- and 4-part fractures of the proximal humerus.Methods: A total of 132 patients with proximal humeral fractures were treated in our hospital from July 1997 to February 2003. According to Neer's classification, the fractures of 45 patients (14 males and 31 females, aged 31-78 years, 56.1 years±7.8 years on an average) belonged to 3- or 4-part fractures (10 patients with 4-part fracture and 35 with 3-part comminuted fracture) and they were treated with shoulder joint arthroplasty. Unipolar prosthesis replacement of the head of humerus was made in 28 cases, while bipolar prosthesis replacement in 2 cases and total shoulder joint replacement in 15 cases. Results: During the follow-up period (range: 12-72 months, mean: 37.3 months±4.1 months), among the 45 patients who suffered from fractures of the proximal humerus and underwent arthroplasty surgery, 44 patients (97.8%) had no postoperative pain and were satisfied with the active range of motion and with the whole treatment results. And radiography showed that the prostheses were at their good position. One patient had postoperative pain because he had so narrow medullary cavity that the humeral prosthesis could not be put deeply enough and the prosthesis head was a little higher over the anatomic level. He did not have good postoperative active range of motion, either. Then he received a review surgery and got satisfied results. Temporary shoulder stiffness was observed in one patient. Manual release of these adhesions improved the shoulder function. No evidence of nonunion of the fracture segments around the humeral prosthesis stem was found. Conclusions: Shoulder arthroplasty is a dependable method to restore the comfort and function of the should joints of the patients with 3- or 4-part fractures of the proximal humerus.

  14. Proximal femoral reconstruction with custom mega prosthesis

    OpenAIRE

    2003-01-01

    Seventy-seven patients with proximal femoral tumours underwent limb salvage surgery with custom mega prostheses between July 1989 and January 2002. We describe 44 cases with a mean follow-up of 57.8 months. Forty-one patients presented with malignant neoplasms of which 11 were malignant giant cell tumours, eight were chondrosarcoma and five were metastases. Wide margins were achieved for all malignant tumours, and marginal resection was done for all benign and metastatic lesions. Six patients...

  15. Proximal monomelic amyotrophy of the upper limb.

    Science.gov (United States)

    Amir, D; Magora, A; Vatine, J J

    1987-07-01

    A 30-year-old patient of Central European origin, suffering from monomelic amyotrophy, is presented. The disease was characterized by proximal weakness of one upper limb, mainly of the shoulder girdle, accompanied by atrophy. The electrodiagnostic examination revealed signs of partial denervation in the presence of normal motor and sensory conduction. The disease, which is probably of the anterior horn cells, had a benign course and good prognosis, as evident from repeated examinations during a follow-up of eight years.

  16. Proximal relationships between PTSD and drinking behavior

    OpenAIRE

    2014-01-01

    Co-morbid PTSD and alcohol use disorders are both common and debilitating. However, many of these studies rely on cross-sectional studies that obscure more complex relationships between PTSD and drinking. Event-level studies allow for examination of proximal relationships between PTSD and drinking. Among women (n=136 with past sexual victimization, n=40 no past trauma history), a two-part mixed hurdle model was used to examine daily PTSD and drinking. On days women experienced more intrusive ...

  17. Isolated Proximal Tibiofibular Dislocation during Soccer

    Directory of Open Access Journals (Sweden)

    Casey Chiu

    2015-01-01

    Full Text Available Proximal tibiofibular dislocations are rarely encountered in the Emergency Department (ED. We present a case involving a man presenting to the ED with left knee pain after making a sharp left turn on the soccer field. His physical exam was only remarkable for tenderness over the lateral fibular head. His X-rays showed subtle abnormalities of the tibiofibular joint. The dislocation was reduced and the patient was discharged from the ED with orthopedic follow-up.

  18. Bilateral Brodie's abscess at the proximal tibia.

    Science.gov (United States)

    Buldu, Halil; Bilen, Fikri Erkal; Eralp, Levent; Kocaoglu, Mehmet

    2012-08-01

    Brodie's abscess is a form of subacute osteomyelitis, which typically involves the metaphyses of the long tubular bones, particularly in the tibia. The diagnosis is usually made incidentally, as there are no accompanying symptoms or laboratory studies. Bilateral involvement at the proximal tibia is unusual. However, orthopaedic surgeons should be aware of this entity, as it may present without symptoms. Checking the contralateral limb for concomitant Brodie's abscess is recommended.

  19. Cassini at Saturn Proximal Orbits - Attitude Control Challenges

    Science.gov (United States)

    Burk, Thomas A.

    2013-01-01

    The Cassini mission at Saturn will come to an end in the spring and summer of 2017 with a series of 22 orbits that will dip inside the rings of Saturn. These are called proximal orbits and will conclude with spacecraft disposal into the atmosphere of the ringed world on September 15, 2017. These unique orbits that cross the ring plane only a few thousand kilometers above the cloud tops of the planet present new attitude control challenges for the Cassini operations team. Crossing the ring plane so close to the inner edge of the rings means that the Cassini orientation during the crossing will be tailored to protect the sensitive electronics bus of the spacecraft. This orientation will put the sun sensors at some extra risk so this paper discusses how the team prepares for dust hazards. Periapsis is so close to the planet that spacecraft controllability with RCS thrusters needs to be evaluated because of the predicted atmospheric torque near closest approach to Saturn. Radiation during the ring plane crossings will likely trigger single event transients in some attitude control sensors. This paper discusses how the attitude control team deals with radiation hazards. The angular size and unique geometry of the rings and Saturn near periapsis means that star identification will be interrupted and this paper discusses how the safe mode attitude is selected to best deal with these large bright bodies during the proximal orbits.

  20. Proximal femur reconstruction by an allograft prosthesis composite.

    Science.gov (United States)

    Donati, Davide; Giacomini, Stefano; Gozzi, Enrico; Mercuri, Mario

    2002-01-01

    Twenty-seven patients who had resection of the proximal femur for bone tumors and reconstruction with an allograft prosthesis composite are reported. In most of the patients, the prosthesis was a long-stem revision type, cemented in the allograft and uncemented in the femoral shaft. The abductor muscles and iliopsoas were sutured to the corresponding tendons on the allograft. Implant-related complications and functional results were evaluated and are reported. Twenty-two patients achieved a minimum followup of 36 months (range, 36-126 months; average, 58 months). The implant was removed in two patients (one for infection, one for intraoperative fracture of the allograft). One patient experienced nonunion, whereas in the remaining 24 patients, the allograft eventually united to the host bone. A frequent late complication (17 patients) was fracture of the greater trochanter of the allograft. In the whole series, only four new operations were done for implant-related complications. In 22 patients who could be evaluated, the functional evaluation according to the Musculoskeletal Tumor Society System was excellent in 16 (73%) patients, good in four (18%), and fair in two (9%). These results compare favorably with those of megaprostheses for tumor resection of the proximal femur, where a Trendelenburg gait almost always is present.

  1. Cassini at Saturn Proximal Orbits - Attitude Control Challenges

    Science.gov (United States)

    Burk, Thomas A.

    2013-01-01

    The Cassini mission at Saturn will come to an end in the spring and summer of 2017 with a series of 22 orbits that will dip inside the rings of Saturn. These are called proximal orbits and will conclude with spacecraft disposal into the atmosphere of the ringed world on September 15, 2017. These unique orbits that cross the ring plane only a few thousand kilometers above the cloud tops of the planet present new attitude control challenges for the Cassini operations team. Crossing the ring plane so close to the inner edge of the rings means that the Cassini orientation during the crossing will be tailored to protect the sensitive electronics bus of the spacecraft. This orientation will put the sun sensors at some extra risk so this paper discusses how the team prepares for dust hazards. Periapsis is so close to the planet that spacecraft controllability with RCS thrusters needs to be evaluated because of the predicted atmospheric torque near closest approach to Saturn. Radiation during the ring plane crossings will likely trigger single event transients in some attitude control sensors. This paper discusses how the attitude control team deals with radiation hazards. The angular size and unique geometry of the rings and Saturn near periapsis means that star identification will be interrupted and this paper discusses how the safe mode attitude is selected to best deal with these large bright bodies during the proximal orbits.

  2. Temperature as a proximate factor in orientation behavior

    Energy Technology Data Exchange (ETDEWEB)

    Reynolds, W.W.

    1977-05-01

    Temperature serves as a proximate factor (cue, guidepost, sign stimulus, or directive factor) affecting locomotor responses of fishes. Although temperature can also serve as an ultimate ecological factor, as in behavioral thermoregulation, nonthermal factors may in some cases provide the ultimate adaptive or ecological value of a temperature response; some examples are habitat selection, intraspecific size segregation, interspecific niche differentiation, isolating mechanisms, predator avoidance, prey location, escape reactions, and migrations (thermoperiodic, diel, seasonal, spawning). Conversely, nonthermal variables such as light intensity or water depth may act as accessory proximate factors in thermoregulation. In spawning migrations, thermal requirements of eggs and larvae may take precedence over the (often different) preferenda or optima of adults. Although thermal responses of fishes are largely innate and species specific, ontogenetic and other changes can occur. Since temperature can serve as an unconditioned reinforcer in operant conditioning, thermal responses are not limited to simple kineses or taxes. Nonthermal factors such as photoperiod, circadian rhythms, currents, social and biotic interactions, stresses, infections, or chemicals can affect thermal responses, and may account for some lack of conformity between laboratory preferenda and field distributions and behaviors.

  3. A proximity effect in adults' contamination intuitions

    Directory of Open Access Journals (Sweden)

    Laura R. Kim

    2011-04-01

    Full Text Available Magical beliefs about contagion via contact (Rozin, Nemeroff, Wane, and Sherrod, 1989 may emerge when people overgeneralize real-world mechanisms of contamination beyond their appropriate boundaries (Lindeman and Aarnio, 2007. Do people similarly overextend knowledge of airborne contamination mechanisms? Previous work has shown that very young children believe merely being close to a contamination source can contaminate an item (Springer and Belk 1994; we asked whether this same hyper-avoidant intuition is also reflected in adults' judgments. In two studies, we measured adults' ratings of the desirability of an object that had made contact with a source of contamination, an object nearby that had made no contact with the contaminant, and an object far away that had also made no contact. Adults showed a clear proximity effect, wherein objects near the contamination source were perceived to be less desirable than those far away, even though a separate group of adults unanimously acknowledged that contaminants could not possibly have made contact with either the nearby or far-away object (Study 1. The proximity effect also remained robust when a third group of adults was explicitly told that no contaminating particles had made contact with the objects at any time (Study 2. We discuss implications of our findings for extending the scope of magical contagion effects beyond the contact principle, for understanding the persistence of intuitive theories despite broad acceptance of science-based theories, and for constraining interpretations of the developmental work on proximity beliefs.

  4. Proximity effect correction concerning forward scattering

    Science.gov (United States)

    Tsunoda, Dai; Shoji, Masahiro; Tsunoe, Hiroyuki

    2010-09-01

    The Proximity Effect is a critical problem in EB Lithography which is used in Photomask writing. Proximity Effect means that an electron shot by gun scatters by collided with resist molecule or substrate atom causes CD variation depending on pattern density [1]. Scattering by collision with resist molecule is called as "forward scattering", that affects in dozens of nanometer range, and with substrate atom is called as "backward scattering, that affects approximately 10 micrometer in 50keV acceleration voltage respectively. In conventional Proximity Effect Correction (PEC) for mask writing, we don't need to think forward scattering effect. However we should think about forward scattering because of smaller feature size. We have proposed a PEC software product named "PATACON PC-Cluster"[2], which can concern forward scattering and calculate optimum dose modulation. In this communication, we explain the PEC processing throughput when the that takes forward scattering into account. The key technique is to use different processing field size for forward scattering calculation. Additionally, the possibility is shown that effective PEC may be available by connecting forward scattering and backward scattering.

  5. Proximate Analysis of Dragon Fruit (Hylecereus polyhizus

    Directory of Open Access Journals (Sweden)

    Ruzainah A. Jaafar

    2009-01-01

    Full Text Available Problem statement: Dragon fruit (Hylecereus polyhizus is well known for the rich nutrient contents and it is commercially available worldwide for improving many health problems. Several studies show the proximity value of red pitaya fruits but the nutrient composition of the stem has not been extensively studied. Approach: This study was carried out to measure the proximate analysis of moisture content, water activity, ash, crude protein, crude fat, crude fiber, glucose and ascorbic acids content in premature and mature of dragon fruit. The dried powder was produced from the stem of dragon fruit and the proximate analysis of dragon fruit stem was compared between freeze drying process and drying oven process. Results: Results of this study showed that 96% moisture; 0.270 g of protein; 0.552 g L-1 glucose and 132.95 mg L-1 ascorbic acid of dragon fruit stem found higher than the fruit flesh of the dragon fruit. Conclusion: The premature stem had higher values than the mature stem of the dragon fruit which may helpful in preventing the risk factors of certain diseases.

  6. Proximal Gastrojejunal Reconstruction after Pancreaticoduodenal Resection

    Directory of Open Access Journals (Sweden)

    M. Wayne

    2012-01-01

    Full Text Available Introduction. Reconstruction by proximal gastrojejunostomy, and distal biliary and pancreatic anastomoses is infrequently used after resection of the head of the pancreas because of fear of fistulas and cholangitis. Pancreaticoduodenectomy is being performed more frequently for cystic malignant and premalignant lesions. Because of this there is a need for endoscopic visualization and biopsy of the residual pancreatic duct, since multi-centricity is characteristic of some of these malignancies. Since endoscopic access of the bile duct and pancreatic duct is difficult and unsuccessful in 50–70% after B II or Roux Y reconstruction, we prospectively studied the merit and complications (early and late of proximal gastrojejunal (PGJ reconstruction after pancreaticoduodenal resection. Material and Methods. Thirty nine consecutive, non-radomized patients underwent pancreaticoduodenectomy and PGJ reconstruction over 14 mos. There were 21 males and 18 females. Results. 7 patients with IPMN have undergone repeat CT scanning for surveillance, with 3 requiring repeat EUS and ERCP. There were no technical difficulties accessing the pancreas or the pancreatic duct, supporting the PGJ reconstruction. Conclusion. Proximal gastrojejunal reconstruction following pancreaticoduodenal resection may be safely done with similar morbidity to traditional pancreaticojejunal reconstructions. PGJ reconstruction may be of greater value when direct visual access to the bile duct or pancreatic duct is necessary, and should be considered when doing resection for mucinous cysts or IPMN of the head of the pancreas.

  7. Proximity Utilizing Biotinylation of Nuclear Proteins in vivo

    Directory of Open Access Journals (Sweden)

    Arman Kulyyassov

    2015-06-01

    Full Text Available Introduction. The human genome consists of roughly 30,000 genes coding for over 500,000 different proteins, of which more than 10,000 proteins can be produced by the cell at any given time (the cellular “proteome”. It has been estimated that over 80% of proteins do not operate alone, but in complexes. These protein-protein interactions (PPI are regulated by several mechanisms. For example, post-translational modifications (methylation, acetylation, phosphorylation, or ubiquitination or metal-binding can lead to conformational changes that alter the affinity and kinetic parameters of the interaction. Many PPIs are part of larger cellular networks of interactions or interactomes. Indeed, these interactions are at the core of the entire interactomics system of any living cell, and so, aberrant PPIs are the basis of multiple diseases, such as neurodegenerative diseases and cancer. The objective of this study was to develop a method of monitoring protein-protein interactions and proximity dependence in vivo.Methods. The biotin ligase BirA was fused to the protein of interest, and the Biotin Acceptor Peptide (BAP was fused to an interacting partner to make the detection of its biotinylation possible by western blot or mass spectrometry.Results. Using several experimental systems (BirA.A + BAP.B, we showed that the biotinylation is interaction/proximity dependent. Here, A and B are the next nuclear proteins used in the experiments – 3 paralogues of heterochromatin protein HP1a (CBX5, HP1b (CBX1, HP1g (CBX3, wild type and transcription mutant factor Kap1, translesion DNA polymerase PolH and E3, ubiquitin ligase RAD18, Proliferative Cell Nuclear Antigen (PCNA, ubiquitin Ub, SUMO-2/3, different types and isoforms of histones H2A, H2Az, H3.1, H3.3, CenpA, H2A.BBD, and macroH2A. The variant of this approach is termed PUB-NChIP (Proximity Utilizing Biotinylation with Native Chromatin Immuno-precipitation and is designed to purify and study the protein

  8. A Regularized Algorithm for the Proximal Split Feasibility Problem

    Directory of Open Access Journals (Sweden)

    Zhangsong Yao

    2014-01-01

    Full Text Available The proximal split feasibility problem has been studied. A regularized method has been presented for solving the proximal split feasibility problem. Strong convergence theorem is given.

  9. Proximity to coast is linked to climate change belief

    National Research Council Canada - National Science Library

    Milfont, Taciano L; Evans, Laurel; Sibley, Chris G; Ries, Jan; Cunningham, Andrew

    2014-01-01

    .... The present study examined the relationship between physical proximity to the coastline and climate change belief, as proximity may be related to experiencing or anticipating the effects of climate...

  10. Chemical gas analyzers for proximate analysis of mine atmosphere

    Energy Technology Data Exchange (ETDEWEB)

    Pochenkova, T.K.; Klassovskaya, N.A.; Zlenko, A.G.; Gus' kova, A.N. (Vsesoyuznyi Nauchno-Issledovatel' skii Institut Gornogo Dela, Donetsk (Ukraine))

    1992-09-01

    Describes a series of chemical gas analyzers developed by the VNIIGD institute for proximate analysis of mine atmosphere in coal mines. The new GKh-4, GKh-5, GKh-6, GKh CO-5 use detector tubes for carbon monoxide and dioxide, nitrogen oxides, sulfur dioxide, oxygen and hydrogen sulfide. These devices allow miners to determine gas concentrations in the mine atmosphere in less than 4 minutes with an accuracy of +/-25%. The series is now complemented by the GKh-M CH[sub 2]O-0.004 gas analyzer for measuring formaldehyde content in mine air during mine rescue operations conducted with the use of carbamide-formaldehyde resins. Key technical data on the gas analyzers are given.

  11. Proximity Induced Superconducting Properties in One and Two Dimensional Semiconductors

    DEFF Research Database (Denmark)

    Kjærgaard, Morten

    that a superconducting 1D nanowire can harbor Majorana bound states in the absence of spin–orbit coupling. We fabricate and measure micrometer–sized mesoscopic devices demonstrating the inheritance of superconducting properties in the 2D electron gas. By placing a quantum point contact proximal to the interface between...... the 2D electron gas and the aluminum, we are able to demonstrate quantization of conductance in units of 4e2/h indicative of perfect Andreev reflection at the interface. We show that the quantum point contact can be operated as a tunnel probe to locally measure the density of states in the electron gas...... with a superconducting pairing potential, Majorana bound states can exist in the absence of spin–orbit coupling. Our proposal dispenses with spin–orbit coupling at the expense of a locally varying magnetic field. The presence of the topological state is demonstrated analytically by mapping our model onto...

  12. Shoulder arthroplasty in complex acute and chronic proximal humeral fractures

    DEFF Research Database (Denmark)

    Frich, Lars Henrik; Søjbjerg, J.O.; Sneppen, O.

    1991-01-01

    From 1983 to 1988, 42 shoulder arthroplasties were performed on comminuted acute or chronic proximal humeral fractures. Patients were categorized according to the post-fracture operative delay; there were 15 four-part fractures, with median post-fracture delay of 13 days (range: 7 to 21), and 27...... chronic fractures, including 11 four-part fractures, 9 three-part fractures, and 7 two-part fractures, with median post-fracture delay of 14 months (range: 4 to 72). Follow up was approximately 2 years in both groups (range: 1 to 5). All patients were evaluated according to a modified Neer score...... to a good result obtained by 6 patients (22%) in the chronic group. Two patients (13%) in the acute group and 11 patients (40%) in the chronic group had a poor result. There were no statistical differences between two-part, three-part, or four-part fractures in the chronic group. Five cases of persistent...

  13. Control of spacecraft with relay-impulse and continuous-action controllers on the basis of an algorithm with a predictive model and its application to spacecraft rendezvous dynamics

    Science.gov (United States)

    Zubov, N. E.

    1989-03-01

    The paper examines the problem of spacecraft control with simultaneously functioning relay-impulse and continuous-action controllers using a modified optimal control algorithm with a predictive model reproducing the motion of the vehicle in accelerated time. The proposed theory is applied to the control of spacecraft rendezvous in an orbital coordinate system.

  14. A RETROSPECTIVE STUDY OF PROXIMAL HUMERUS INTERNAL LOCKING SYSTEM PLATING FOR DISPLACED PROXIMAL HUMERUS FRACTURES

    Directory of Open Access Journals (Sweden)

    Kumarswami Ramulu

    2016-05-01

    Full Text Available AIM The aim of the present study was to evaluate the functional outcome, benefits and complications of open reduction and internal fixation of displaced proximal humerus fractures with proximal humerus locking plate. METHODS We studied the functional outcome of 40 patients aged between 15 to 65 years from September 2013 to February 2015, who had displaced proximal humerus fracture and underwent PHILOS plate fixation for the same. Fractures were classified according to NEER’s and AO classification. Patients were followed up for a minimum period of 1 year. Functional outcomes and shoulder range of movement were assessed based on the Constant and Murley scoring system. RESULTS Patients were followed up for 12 months. All fractures healed satisfactorily; 12 weeks (27.5% was the most common union time (radiological finding in the study population followed by 8 weeks (22.5% and 10 weeks (20%. Avascular necrosis was noted in 1 patient, mild infection in 2 patients and stiffness in 2 patients. The mean Constant score at 6 weeks was 40.39, at 12 weeks was 59.24, at 6 months was 73.88 and at one year was 75.62. Constant score continues to improve till 1 year. CONCLUSION Proximal humerus locking plate gives a reliable, stable fixation for fractures of proximal humerus with a good radiological union and good functional outcome.

  15. The regional dimension of intergenerational proximity in the Netherlands

    NARCIS (Netherlands)

    van der Pers, Marieke; Mulder, Clara H.

    2013-01-01

    Previous research has shown the impact of individual characteristics on intergenerational proximity but has largely ignored the regional dimension of such proximity. In this paper, we examine the regional variation in intergenerational proximity in the Netherlands. We address this issue by incorpora

  16. [Osteoporotic fractures of the proximal femur. What's new?].

    Science.gov (United States)

    Bonnaire, F; Straßberger, C; Kieb, M; Bula, P

    2012-10-01

    Proximal femoral fractures in the elderly are still increasing and are almost always associated with osteoporosis. Especially the over 80-year-olds are increasing and at risk in this respect. In the treatment of these patients new knowledge has been achieved over the last years. An interdisciplinary, multimodal approach with early involvement of internists, geriatricians, anesthetists, osteologists, social workers, care facilities and outpatient trauma and orthopedic surgeons seems to generate a better outcome with fewer complications. In cases of suspected proximal femoral fracture diagnostic imaging should include a computed tomography scan of the posterior pelvic ring to detect commonly occurring fragility fractures of the lateral mass of the sacrum. Early surgery within the first 48 h has a significant positive effect with respect to general and local complications and early mortality. Medical and organizational barriers to an early operation, such as anticoagulant medication, limited capability of communication due to mental dysfunction and lack of operation capacity are continuously declining and subsequently complication rates are decreasing annually in Germany. Endoprosthetics are still associated with higher perioperative mortality than osteosynthesis (4.4 % versus 5.8 %). The innovations in the field of implants and surgical technique also contribute to these lower complication rates. While endoprosthetic treatment is still the gold standard for severely dislocated femoral neck fractures, non-dislocated or slightly dislocated fractures should be fixed with a stable extramedullary implant. For pertrochanteric fractures extramedullary stabilization can only be recommended for stable types of fractures. Every instable trochanteric fracture should be fixed with an intramedullary implant. The use of third generation nails has implicated a significant reduction of complication rates regarding cut-out and reoperations. Rotational fixing of the head

  17. Bone remodelling in the proximal femur after Charnley total hip arthroplasty.

    Science.gov (United States)

    Cohen, B; Rushton, N

    1995-09-01

    We measured bone mineral density (BMD) in the proximal femur by dual-energy X-ray absorptiometry (DEXA) in 20 patients after cemented total hip arthroplasty over a period of one year. We found a statistically significant reduction in periprosthetic BMD after six months on the medial side and on the lateral side adjacent to the mid and distal thirds of the prosthesis. At one year after operation there was a mean 6.7% reduction in BMD in the region of the calcar and a mean 5.3% increase in BMD in the femoral shaft distal to the tip of the implant. These changes reflect a pattern of reduced stress in the proximal femur and increased stress around the tip of the prosthesis. They support current concepts of bone remodelling in the proximal femur in response to prosthetic implantation.

  18. The potential and prospects of proximal remote sensing of arthropod pests.

    Science.gov (United States)

    Nansen, Christian

    2016-04-01

    Bench-top or proximal remote sensing applications are widely used as part of quality control and machine vision systems in commercial operations. In addition, these technologies are becoming increasingly important in insect systematics and studies of insect physiology and pest management. This paper provides a review and discussion of how proximal remote sensing may contribute valuable quantitative information regarding identification of species, assessment of insect responses to insecticides, insect host responses to parasitoids and performance of biological control agents. The future role of proximal remote sensing is discussed as an exciting path for novel paths of multidisciplinary research among entomologists and scientists from a wide range of other disciplines, including image processing engineers, medical engineers, research pharmacists and computer scientists. © 2015 Society of Chemical Industry.

  19. EVALUATION OF POST-OPERATIVE SENSITIVITY AND ...

    African Journals Online (AJOL)

    Prof

    composites in wear resistance and achievement of good proximal contour ... change in result was recorded for post-operative sensitivity at the end of the evaluation period. 100% was recorded ..... Overcoming challenges with resin in class II ...

  20. Temporal Proximity Promotes Integration of Overlapping Events.

    Science.gov (United States)

    Zeithamova, Dagmar; Preston, Alison R

    2017-03-02

    Events with overlapping elements can be encoded as two separate representations or linked into an integrated representation; yet, we know little about the conditions that promote one form of representation over the other. Here, we tested the hypothesis that the proximity of overlapping events would increase the probability of integration. Participants first established memories for house-object and face-object pairs; half of the pairs were learned 24 hr before a fMRI session, and the other half 30 min before the session. During scanning, participants encoded object-object pairs that overlapped with the initial pairs acquired on the same or prior day. Participants were also scanned as they made inference judgments about the relationships among overlapping pairs learned on the same or different day. Participants were more accurate and faster when inferring relationships among memories learned on the same day relative to those acquired across days, suggesting that temporal proximity promotes integration. Evidence for reactivation of existing memories-as measured by a visual content classifier-was equivalent during encoding of overlapping pairs from the two temporal conditions. In contrast, evidence for integration-as measured by a mnemonic strategy classifier from an independent study [Richter, F. R., Chanales, A. J. H., & Kuhl, B. A. Predicting the integration of overlapping memories by decoding mnemonic processing states during learning. Neuroimage, 124, 323-335, 2016]-was greater for same-day overlapping events, paralleling the behavioral results. During inference itself, activation patterns further differentiated when participants were making inferences about events acquired on the same day versus across days. These findings indicate that temporal proximity of events promotes integration and further influences the neural mechanisms engaged during inference.

  1. Proximity effect-induced superconducting networks

    Science.gov (United States)

    Tsuchiya, S.; Tanda, S.

    2009-02-01

    We have studied proximity effect-induced superconductivity of micro wire networks in a magnetic field for investigating topological effects of the superconducting order parameter through Little-Parks oscillation. We prepared a regular honeycomb network, which has Pb-Au bilayer structure, by standard electron beam lithography and measured variation of superconducting transition temperature (Tc) in a magnetic field. We also fabricated a honeycomb network made of Pb monolayer and measured it in the same way. In the experimental results of the monolayer network, 2.06 ± 0.02 Gauss of periodic variation of Tc in a magnetic field was observed at around 7.2 K. The area estimated from this period is 10.04 μm2 and correspond to unit honeycomb enclosed by center of the wire. While, in the results of the bilayer network, 2.66 ± 0.04 Gauss of periodic variation of Tc in a magnetic field was observed at around 4.3 K because of the proximity effect. The area estimated from this period is 7.78 μm2 and correspond to unit honeycomb enclosed by edge of the wire. In the latter case, the superconducting current flows through edge of the wire since the order parameter can be considered to be more developed and inhomogeneous on the wire cross-section at around 4.3 K less than 7.2 K. Consequently, a novel network of paths flowing through the superconducting current, which consists of loops enclosed by edge of the wire, can be realized by controlling the proximity effect.

  2. Development of genu valgum after removal of osteochondromas from the proximal tibia.

    Science.gov (United States)

    Denduluri, Sahitya K; Lu, Min; Bielski, Robert J

    2016-11-01

    Genu valgum is a well-documented deformity secondary to hereditary multiple exostoses about the knee. Post-traumatic tibia valgus is also a well-described phenomenon that occurs in children who sustain an incomplete fracture of the proximal tibia. The finding is considered to be secondary to asymmetric blood flow to the proximal tibial physis. The existing literature only describes genu valgum as a sequela of the hereditary multiple exostoses disorder itself and does not address genu valgum occurring as a postoperative consequence of mass excision. In this paper, we report on three pediatric patients who developed unilateral genu valgum after removal of osteochondromas from the medial proximal tibia. Chart and radiographic data were retrospectively reviewed for a series of three patients. Three patients developed genu valgum after medial proximal tibial osteochondroma excision. The maximum tibiofemoral angle varied from 17 to 23°. One case resolved spontaneously with observation, one was addressed surgically with guided growth correction, and another was advised to undergo operative correction, but declined. We conclude that genu valgum can arise secondary to osteochondroma excision when the mass is resected near the proximal tibial physis. Surgeons should counsel patients on the possibility of postoperative angular growth deformity and monitor closely for its development.

  3. A STUDY ON SURGICAL MANAGEMENT OF INTERTROCHANTERIC AND SUBTROCHANTERIC FRACTURES OF FEMUR BY PROXIMAL FEMORAL NAIL

    Directory of Open Access Journals (Sweden)

    Kuppa Srinivas

    2015-01-01

    Full Text Available AIMS AND OBJECTIVES: To study the various fracture patte rns, mechanism of injury, operative difficulties encountered, result in terms of radiological union and ultimate functional outcome of intertrochanteric and subtrochanteric fractures of femur treated by proximal femoral nail. RESULTS: In the present study , 22 cases of subtrochanteric and intertrochanteric fractures of proximal femur treated by proximal femoral nail at Govt. General Hospital, Kurnool from August 2010 to July 2012 were included. Out of 22 cases, 18 were subtrochanteric and 4 were intertrochanteric fractures. In subtrochanteric fractures, seinsheimer type III were 44.4%,in intertrochanteric fractures evan’s unstable fractures were 75%. The mean age group was 45years with males 82%, right side femur were involved in 55%, road traffic accidents accounted for 55%, associated injuries found in 36%. Mean duration of hospital stay was 16.83 days, union was achieved in 86.6% with mean time for union was 12.75 weeks. Hip joint stiffness was found 23% and non - union in 4%. CONCLUSI ON: By the analysis of data collected in the present study, proximal femoral nail is an effective device in the management of complex proximal femoral fractures. It offers superior stabilization and good fracture union

  4. Periprosthetic proximal femur fractures: current concepts.

    Science.gov (United States)

    Parvizi, Javad; Vegari, David N

    2011-06-01

    With the increase in demand for total hip and knee arthroplasty, the orthopaedic community has seen a dramatic increase in periprosthetic fractures. Given the high morbidity and mortality associated with these fractures, the orthopaedic surgeon needs to be prepared to deal with this difficult problem. The purpose of this article is to provide the surgeon with an algorithmic approach that allows for easy classification and treatment options for periprosthetic fractures of the proximal femur. Such an approach should prevent the mismanagement of these complications.

  5. Proximal iliotibial band syndrome: case report

    Directory of Open Access Journals (Sweden)

    Guilherme Guadagnini Falotico

    2013-08-01

    Full Text Available OBJECTIVE: The overuse injuries in the hip joint occur commonly in sports practitioners and currently due to technical advances in diagnostic imaging, especially magnetic resonance imaging (MRI, are often misdiagnosed. Recently, a group of people were reported, all female, with pain and swelling in the pelvic region.T2-weighted MRI showed increased signal in the enthesis of the iliotibial band (ITB along the lower border of the iliac tubercle. We report a case of a 34 year old woman, non-professional runner, with pain at the iliac crest with no history of trauma and whose MRI was compatible with the proximal iliotibial band syndrome.

  6. Management of posttraumatic proximal interphalangeal joint contracture.

    Science.gov (United States)

    Houshian, Shirzad; Jing, Shan Shan; Chikkamuniyappa, Chandrasekar; Kazemian, Gholam Hussein; Emami-Moghaddam-Tehrani, Mohammad

    2013-08-01

    Chronic flexion contracture of the proximal interphalangeal (PIP) joint presents a common yet challenging problem to hand surgeons. Over the years, multiple treatment modalities have been described for this problem, producing limited results. Nonoperative treatment using serial casting and splints should be tried before attempting open surgical release, which should be done in selected patients. The use of external fixation for treating PIP contracture has been encouraging and can be a useful alterative. This review provides an update on the current management of PIP joint contractures and presents a flowchart of treatment to aid decision making. Copyright © 2013 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

  7. Proximity Action theory of superconductive nanostructures

    Energy Technology Data Exchange (ETDEWEB)

    Skvortsov, M A; Larkin, A I; Feigel' man, M V [L D Landau Institute for Theoretical Physics, Russian Academy of Sciences, ul. Kosygina 2, 117940 Moscow (Russian Federation)

    2001-10-01

    We review a novel approach to the superconductive proximity effect in disordered normal-superconducting (N-S) structures. The method is based on the multicharge Keldysh action and is suitable for the treatment of interaction and fluctuation effects. As an application of the formalism, we study the subgap conductance and noise in two-dimensional N-S systems in the presence of the electron-electron interaction in the Cooper channel. It is shown that singular nature of the interaction correction at large scales leads to a nonmonotonuos temperature, voltage and magnetic field dependence of the Andreev conductance. (4. mesoscopic superconductivity)

  8. Impacted valgus fractures of the proximal humerus☆

    Science.gov (United States)

    Ribeiro, Fabiano Rebouças; Takesian, Fernando Hovaguim; Bezerra, Luiz Eduardo Pimentel; Filho, Rômulo Brasil; Júnior, Antonio Carlos Tenor; da Costa, Miguel Pereira

    2016-01-01

    Impacted valgus fractures of the proximal humerus are considered to be a special type fracture, since impaction of the humeral head on the metaphysis with maintenance of the posteromedial periosteum improves the prognosis regarding occurrences of avascular necrosis. This characteristic can also facilitate the reduction maneuver and increase the consolidation rate of these fractures, even in more complex cases. The studies included were obtained by searching the Bireme, Medline, PubMed, Cochrane Library and Google Scholar databases for those published between 1991 and 2013. The objective of this study was to identify the most common definitions, classifications and treatment methods used for these fractures in the orthopedic medical literature. PMID:27069878

  9. OBTURACIONES DE RESINA EN LA ZONA PROXIMAL.

    OpenAIRE

    Lahoud Salem, Víctor; Doctor en 0dontología Profesor Principal del Departamento Académico de Estomatología Rehabilitadora. Fac. Odontología UNMSM.

    2014-01-01

    Las restauraciones de resinas en la zona proximal serán en el futuro la alternativa más importante a la obturación de amalgama. El éxito y el fracaso dependen fundamentalmente de la indicación a causa de la compleja técnica de trabajo y de las características del material. El tratamiento de pequeños defectos, en particular lesiones primarias, presentan mejores posibilidades que las restauraciones de cavidades mayores.Persiste cierta inseguridad al restaurar con resina las cavidades de clase I...

  10. Keldysh proximity action for disordered superconductors

    Indian Academy of Sciences (India)

    M V Feigel'man; A I Larkin; M A Skvortsov

    2005-06-01

    We review a novel approach to the superconductive proximity effect in disordered normal–superconducting (N–S) structures. The method is based on the multicharge Keldysh action and is suitable for the treatment of interaction and fluctuation effects. As an application of the formalism, we study the subgap conductance and noise in two-dimensional N–S systems in the presence of the electron–electron interaction in the Cooper channel. It is shown that singular nature of the interaction correction at large scales leads to a nonmonotonuos temperature, voltage and magnetic field dependence of the Andreev conductance.

  11. Flight Dynamics Operations: Methods and Lessons Learned from Space Shuttle Orbit Operations

    Science.gov (United States)

    Cutri-Kohart, Rebecca M.

    2011-01-01

    The Flight Dynamics Officer is responsible for trajectory maintenance of the Space Shuttle. This paper will cover high level operational considerations, methodology, procedures, and lessons learned involved in performing the functions of orbit and rendezvous Flight Dynamics Officer and leading the team of flight dynamics specialists during different phases of flight. The primary functions that will be address are: onboard state vector maintenance, ground ephemeris maintenance, calculation of ground and spacecraft acquisitions, collision avoidance, burn targeting for the primary mission, rendezvous, deorbit and contingencies, separation sequences, emergency deorbit preparation, mass properties coordination, payload deployment planning, coordination with the International Space Station, and coordination with worldwide trajectory customers. Each of these tasks require the Flight Dynamics Officer to have cognizance of the current trajectory state as well as the impact of future events on the trajectory plan in order to properly analyze and react to real-time changes. Additionally, considerations are made to prepare flexible alternative trajectory plans in the case timeline changes or a systems failure impact the primary plan. The evolution of the methodology, procedures, and techniques used by the Flight Dynamics Officer to perform these tasks will be discussed. Particular attention will be given to how specific Space Shuttle mission and training simulation experiences, particularly off-nominal or unexpected events such as shortened mission durations, tank failures, contingency deorbit, navigation errors, conjunctions, and unexpected payload deployments, have influenced the operational procedures and training for performing Space Shuttle flight dynamics operations over the history of the program. These lessons learned can then be extended to future vehicle trajectory operations.

  12. Carbon nanotube proximity influences rice DNA

    Science.gov (United States)

    Katti, Dinesh R.; Sharma, Anurag; Pradhan, Shashindra Man; Katti, Kalpana S.

    2015-07-01

    The uptake of carbon nanotubes (CNT) influences the output of plants, potentially through interactions between the DNA and CNTs. However, little is known about the changes in the plant DNA due to CNT proximity. We report changes in rice plant DNA in the proximity of single walled CNT (SWCNT) using molecular dynamics simulations. The DNA experiences breaking and forming of hydrogen bonds due to unzipping of Watson-Crick (WC) nucleobase pairs and wrapping onto SWCNT. The number of hydrogen bonds between water and DNA nucleobases decreases due to the presence of SWCNT. A higher number of guanine-cytosine (Gua-Cyt) WC hydrogen bonds break as compared to adenine-thymine (Ade-Thy), which suggests that Gua and Cyt bases play a dominant role in DNA-SWCNT interactions. We also find that changes to non-WC nucleobase pairs and van der Waals attractive interactions between WC nucleobase pairs and SWCNT cause significant changes in the conformation of the DNA.

  13. Are classifications of proximal radius fractures reproducible?

    Directory of Open Access Journals (Sweden)

    dos Santos João BG

    2009-10-01

    Full Text Available Abstract Background Fractures of the proximal radius need to be classified in an appropriate and reproducible manner. The aim of this study was to assess the reliability of the three most widely used classification systems. Methods Elbow radiographs images of patients with proximal radius fractures were classified according to Mason, Morrey, and Arbeitsgemeinschaft für osteosynthesefragen/Association for the Study of Internal Fixation (AO/ASIF classifications by four observers with different experience with this subject to assess their intra- and inter-observer agreement. Each observer analyzed the images on three different occasions on a computer with numerical sequence randomly altered. Results We found that intra-observer agreement of Mason and Morrey classifications were satisfactory (κ = 0.582 and 0.554, respectively, while the AO/ASIF classification had poor intra-observer agreement (κ = 0.483. Inter-observer agreement was higher in the Mason (κ = 0.429-0.560 and Morrey (κ = 0.319-0.487 classifications than in the AO/ASIF classification (κ = 0.250-0.478, which showed poor reliability. Conclusion Inter- and intra-observer agreement of the Mason and Morey classifications showed overall satisfactory reliability when compared to the AO/ASIF system. The Mason classification is the most reliable system.

  14. Obesity and Supermarket Access: Proximity or Price?

    Science.gov (United States)

    Aggarwal, Anju; Hurvitz, Philip M.; Monsivais, Pablo; Moudon, Anne V

    2012-01-01

    Objectives. We examined whether physical proximity to supermarkets or supermarket price was more strongly associated with obesity risk. Methods. The Seattle Obesity Study (SOS) collected and geocoded data on home addresses and food shopping destinations for a representative sample of adult residents of King County, Washington. Supermarkets were stratified into 3 price levels based on average cost of the market basket. Sociodemographic and health data were obtained from a telephone survey. Modified Poisson regression was used to test the associations between obesity and supermarket variables. Results. Only 1 in 7 respondents reported shopping at the nearest supermarket. The risk of obesity was not associated with street network distances between home and the nearest supermarket or the supermarket that SOS participants reported as their primary food source. The type of supermarket, by price, was found to be inversely and significantly associated with obesity rates, even after adjusting for individual-level sociodemographic and lifestyle variables, and proximity measures (adjusted relative risk = 0.34; 95% confidence interval = 0.19, 0.63) Conclusions. Improving physical access to supermarkets may be one strategy to deal with the obesity epidemic; improving economic access to healthy foods is another. PMID:22698052

  15. Updated Classification System for Proximal Humeral Fractures

    Science.gov (United States)

    Guix, José M. Mora; Pedrós, Juan Sala; Serrano, Alejandro Castaño

    2009-01-01

    Proximal humeral fractures can restrict daily activities and, therefore, deserve efficient diagnoses that minimize complications and sequels. For good diagnosis and treatment, patient characteristics, variability in the forms of the fractures presented, and the technical difficulties in achieving fair results with surgical treatment should all be taken into account. Current classification systems for these fractures are based on anatomical and pathological principles, and not on systematic image reading. These fractures can appear in many different forms, with many characteristics that must be identified. However, many current classification systems lack good reliability, both inter-observer and intra-observer for different image types. A new approach to image reading, following a well-designed set and sequence of variables to check, is needed. We previously reported such an image reading system. In the present study, we report a classification system based on this image reading system. Here we define 21 fracture characteristics and apply them along with classical Codman approaches to classify fractures. We base this novel classification system for classifying proximal humeral fractures on a review of scientific literature and improvements to our image reading protocol. Patient status, fracture characteristics and surgeon circumstances have been important issues in developing this system. PMID:19574487

  16. Congenital anomalies and proximity to landfill sites.

    LENUS (Irish Health Repository)

    Boyle, E

    2004-01-01

    The occurrence of congenital anomalies in proximity to municipal landfill sites in the Eastern Region (counties Dublin, Kildare, Wicklow) was examined by small area (district electoral division), distance and clustering tendancies in relation to 83 landfills, five of which were major sites. The study included 2136 cases of congenital anomaly, 37,487 births and 1423 controls between 1986 and 1990. For the more populous areas of the region 50% of the population lived within 2-3 km of a landfill and within 4-5 km for more rural areas. In the area-level analysis, the standardised prevalence ratios, empirical and full Bayesian modelling, and Kulldorff\\'s spatial scan statistic found no association between the residential area of cases and location of landfills. In the case control analysis, the mean distance of cases and controls from the nearest landfill was similar. The odds ratios of cases compared to controls for increasing distances from all landfills and major landfills showed no significant difference from the baseline value of 1. The kernel and K methods showed no tendency of cases to cluster in relationship to landfills. In conclusion, congenital anomalies were not found to occur more commonly in proximity to municipal landfills.

  17. Proximate determinants of fertility in peninsular Malaysia.

    Science.gov (United States)

    Tey, Nai Peng; Ng, Sor Tho; Yew, Siew Yong

    2012-05-01

    The continuing decline in fertility despite a contraction in contraceptive use in Peninsular Malaysia since the mid-1980s has triggered considerable interest in the reasons behind this phenomenon, such as increase in abortion, sterility, and out-of-wedlock pregnancy. Fertility decline has been attributed to rapid socioeconomic development, which can only influence fertility through the intermediate variables. Application of vital statistics, population census, and survey data of Peninsular Malaysia on Bongaarts's model vindicates that marriage postponement and contraceptive use are the 2 most important proximate determinants of fertility, but the effects are not uniform across the ethnic groups. For instance, the predicted total fertility rate for Chinese and Malays are 2.9 and 1.6, respectively, compared with the observed level of 3.0 and 1.9. Postpartum infecundability and abortion also play a part in explaining ethnic fertility differentials. The fertility inhibiting effects of these proximate determinants have significant implications on reproductive health and future population growth.

  18. Locking internal fixator with minimally invasive plate osteosynthesis for the proximal and distal tibial fractures

    Institute of Scientific and Technical Information of China (English)

    TONG Da-ke; JI Fang; CAI Xiao-bing

    2011-01-01

    Objective: To investigate the efficacy of the locking internal fixator (LIF), which includes the locking compression plate (LCP) and the less invasive stable system (LISS), in the proximal and distal tibial fractures. Methods: We did a retrospective study on a total of 98 patients with either proximal or distal tibial fractures from January 2003 to January 2007, who had received the operation with LIF by the minimally invasive plate osteosynthesis (MIPO) technique. The data consisted of 43 proximal tibial fractures (type AO41C3) and 55 distal tibial fractures (type AO43C3). Results: No complications were observed in all patients after operation. The mean healing time was 8.4 months (range 5-14 months). Only two cases of delayed union occurred at postoperative 10 months. No infections were reported after the definitive surgery even in the cases of open fractures. All patients reached a full range of motion at postoperative 6 to 9 months and regained the normal functions of knee and ankle joints. Conclusion: Using LIF in MIPO technique is a reliable approach towards the proximal and distal tibial fractures that are not suitable for intramedullary nailing.

  19. The convergence rate of the proximal alternating direction method of multipliers with indefinite proximal regularization

    Directory of Open Access Journals (Sweden)

    Min Sun

    2017-01-01

    Full Text Available Abstract The proximal alternating direction method of multipliers (P-ADMM is an efficient first-order method for solving the separable convex minimization problems. Recently, He et al. have further studied the P-ADMM and relaxed the proximal regularization matrix of its second subproblem to be indefinite. This is especially significant in practical applications since the indefinite proximal matrix can result in a larger step size for the corresponding subproblem and thus can often accelerate the overall convergence speed of the P-ADMM. In this paper, without the assumptions that the feasible set of the studied problem is bounded or the objective function’s component θ i ( ⋅ $\\theta_{i}(\\cdot$ of the studied problem is strongly convex, we prove the worst-case O ( 1 / t $\\mathcal{O}(1/t$ convergence rate in an ergodic sense of the P-ADMM with a general Glowinski relaxation factor γ ∈ ( 0 , 1 + 5 2 $\\gamma\\in(0,\\frac{1+\\sqrt{5}}{2}$ , which is a supplement of the previously known results in this area. Furthermore, some numerical results on compressive sensing are reported to illustrate the effectiveness of the P-ADMM with indefinite proximal regularization.

  20. High-Grade Partial and Retracted (<2 cm) Proximal Hamstring Ruptures

    Science.gov (United States)

    Piposar, Jonathan R.; Vinod, Amrit V.; Olsen, Joshua R.; Lacerte, Edward; Miller, Suzanne L.

    2017-01-01

    Background: High-grade partial proximal hamstring tears and complete tears with retraction less than 2 cm are a subset of proximal hamstring injuries where, historically, treatment has been nonoperative. It is unknown how nonoperative treatment compares with operative treatment. Hypothesis: The clinical and functional outcomes of nonoperative and operative treatment of partial/complete proximal hamstring tears were compared. We hypothesize that operative treatment of these tears leads to better clinical and functional results. Study Design: Case series; Level of evidence, 4. Methods: A retrospective review identified patients with a high-grade partial or complete proximal hamstring rupture with retraction less than 2 cm treated either operatively or nonoperatively from 2007 to 2015. All patients had an initial period of nonoperative treatment. Surgery was offered if patients had continued pain and/or limited function refractory to nonoperative treatment with physical therapy. Outcome measures were each patient’s strength perception, ability to return to activity, Lower Extremity Functional Scale (LEFS) score, Short Form–12 (SF-12) physical and mental component outcome scores, distance traversed by a single-leg hop, and Biodex hamstring strength testing. Results: A total of 25 patients were enrolled in the study. The 15 patients who were treated nonoperatively sustained injuries at a mean age of 55.73 ± 14.83 years and were evaluated 35.47 ± 30.35 months after injury. The 10 patients who elected to have surgery sustained injuries at 50.40 ± 6.31 years of age (P = .23) and were evaluated 30.11 ± 19.43 months after surgery. LEFS scores were significantly greater for the operative group compared with the nonoperative group (77/80 vs 64.3/80; P = .01). SF-12 physical component scores for the operative group were also significantly greater (P = .03). Objectively, operative and nonoperative treatment modalities showed no significant difference in terms of single

  1. An improved proximity force approximation for electrostatics

    CERN Document Server

    Fosco, C D; Mazzitelli, F D

    2012-01-01

    A quite straightforward approximation for the electrostatic interaction between two perfectly conducting surfaces suggests itself when the distance between them is much smaller than the characteristic lengths associated to their shapes. Indeed, in the so called "proximity force approximation" the electrostatic force is evaluated by first dividing each surface into a set of small flat patches, and then adding up the forces due two opposite pairs, the contribution of which are approximated as due to pairs of parallel planes. This approximation has been widely and successfully applied to different contexts, ranging from nuclear physics to Casimir effect calculations. We present here an improvement on this approximation, based on a derivative expansion for the electrostatic energy contained between the surfaces. The results obtained could be useful to discuss the geometric dependence of the electrostatic force, and also as a convenient benchmark for numerical analyses of the tip-sample electrostatic interaction i...

  2. PADDLE: Proximal Algorithm for Dual Dictionaries LEarning

    CERN Document Server

    Basso, Curzio; Verri, Alessandro; Villa, Silvia

    2010-01-01

    Recently, considerable research efforts have been devoted to the design of methods to learn from data overcomplete dictionaries for sparse coding. However, learned dictionaries require the solution of an optimization problem for coding new data. In order to overcome this drawback, we propose an algorithm aimed at learning both a dictionary and its dual: a linear mapping directly performing the coding. By leveraging on proximal methods, our algorithm jointly minimizes the reconstruction error of the dictionary and the coding error of its dual; the sparsity of the representation is induced by an $\\ell_1$-based penalty on its coefficients. The results obtained on synthetic data and real images show that the algorithm is capable of recovering the expected dictionaries. Furthermore, on a benchmark dataset, we show that the image features obtained from the dual matrix yield state-of-the-art classification performance while being much less computational intensive.

  3. [Ophthalmologists in the proximity of Adolf Hitler].

    Science.gov (United States)

    Rohrbach, J M

    2012-10-01

    Adolf Hitler met or at least knew about 5 ophthalmologists. The chair of ophthalmology in Berlin, Walther Löhlein, personally examined Hitler's eyes at least two times. The chair of ophthalmology in Breslau, Walter Dieter, developed "air raid protection spectacles" with the aid of high representatives of the NS-system and probably Adolf Hitler himself. Heinrich Wilhelm Kranz became rector of the universities of Giessen and Frankfurt/Main. He was known as a very strict advocate of the NS-race hygiene. Werner Zabel made plans for Hitler's diet and tried to interfere with Hitler's medical treatment. Finally, Hellmuth Unger was an influential representative of the medical press and a famous writer. Three of his novels with medical topics were made into a film which Hitler probably saw. Hitler had, so to say, a small "ophthalmological proximity" which, however, did not play a significant role for himself or the NS-state.

  4. Proximity to mining industry and cancer mortality.

    Science.gov (United States)

    Fernández-Navarro, Pablo; García-Pérez, Javier; Ramis, Rebeca; Boldo, Elena; López-Abente, Gonzalo

    2012-10-01

    Mining installations are releasing toxic substances into the environment which could pose a health problem to populations in their vicinity. We sought to investigate whether there might be excess cancer-related mortality in populations residing in towns lying in the vicinity of Spanish mining industries governed by the Integrated Pollution Prevention and Control Directive, and the European Pollutant Release and Transfer Register Regulation, according to the type of extraction method used. An ecologic study was designed to examine municipal mortality due to 32 types of cancer, across the period 1997 through 2006. Population exposure to pollution was estimated on the basis of distance from town of residence to pollution source. Poisson regression models, using the Bayesian conditional autoregressive model proposed by Besag, York and Molliè and Integrated Nested Laplace Approximations for Bayesian inference, were used: to analyze risk of dying from cancer in a 5-kilometer zone around mining installations; effect of type of industrial activity; and to conduct individual analyses within a 50-kilometer radius of each installation. Excess mortality (relative risk, 95% credible interval) of colorectal cancer (1.097, 1.041-1.157), lung cancer (1.066, 1.009-1.126) specifically related with proximity to opencast coal mining, bladder cancer (1.106, 1.016-1.203) and leukemia (1.093, 1.003-1.191) related with other opencast mining installations, was detected among the overall population in the vicinity of mining installations. Other tumors also associated in the stratified analysis by type of mine, were: thyroid, gallbladder and liver cancers (underground coal installations); brain cancer (opencast coal mining); stomach cancer (coal and other opencast mining installations); and myeloma (underground mining installations). The results suggested an association between risk of dying due to digestive, respiratory, hematologic and thyroid cancers and proximity to Spanish mining

  5. Anatomical variations of the proximal radius and their effects on osteosynthesis.

    Science.gov (United States)

    Giannicola, Giuseppe; Manauzzi, Erica; Sacchetti, Federico M; Greco, Alessandro; Bullitta, Gianluca; Vestri, Annarita; Cinotti, Gianluca

    2012-05-01

    In fractures of the radial head and neck requiring open reduction and internal fixation, osteosynthesis may be safely applied in a limited zone. We conducted a morphometric study of the proximal radius at the level of the safe zone to identify different morphologic types of this anatomical region. We analyzed 44 dried cadaveric radii. We measured the whole length of the radius, the length of the neck and head, and the minimum and maximum diameter of the radial head. The morphologic aspect of the neck-head curvature of the safe zone was evaluated qualitatively and quantitatively. The proximal radius at the level of the safe zone exhibited different radii of bending. In particular, we identified a morphologic type A, which showed a flat profile (25% of cases), morphologic types B and C, which showed a low concave curvature (64%), and a marked concave curvature (11%), respectively, of the safe zone. The profile of the proximal radius in the safe zone shows substantial morphologic variations that should be taken into account when operating on fractures of the proximal radius, to avoid malunions, pain, and stiffness of the elbow joint. A preoperative radiograph of the contralateral uninjured radius may be helpful in selecting the most appropriate internal fixation device to reconstruct the proximal radius after comminuted fractures. Knowledge of the proper bending radius of the safe zone allows the surgeon to select the most appropriate plate, and to achieve good fracture reduction and anatomical restoration of the proximal radius. Copyright © 2012 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

  6. Relationship between uniform connectedness and proximity in perceptual grouping

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Palmer and Rock proposed that uniform connectedness (UC) occurs prior to classical Gestalt factors to define the primitive units for visual perception. Han, Humphreys and Chen, however, found that grouping by proximity can take place as quickly as that based on UC in a letter discrimination task. The present study employed a letter detection task to examine the relationship between UC and proximity grouping in 3 experiments. We showed that reaction times to targets defined by proximity or UC were equally fast when one or two global objects were presented in the visual field. However, as the number of global objects was increased, responses were faster to targets defined by UC than to targets defined by proximity. In addition, the advantage of UC over proximity was not affected by the space between global objects. The results suggest that UC was more effective than proximity in forming perceptual units under multiple object conditions. Possible reasons for this finding are discussed.

  7. Numerical Analysis of Helicopter Rotor Hovering in Close Proximity to the Ground with a Wall

    Science.gov (United States)

    Itoga, Noriaki; Iboshi, Naohiro; Horimoto, Mitsumasa; Saito, Shigeru; Tanabe, Yasutada

    In rescue operations and emergency medical services, helicopters are frequently required to operate near the ground with obstacles such as buildings and sidewalls of highway. In this paper, numerical analysis of helicopter rotor hovering in close proximity to the ground with an obstacle is done by solving unsteady 3D compressible Euler equations with an overlapped grid system. The obstacle is simulated by a wall vertically set up on the ground. The parameters for numerical analysis are the rotor height and distance from the rotor-hub-center to the wall. The effects of combinations of these parameters on the flowfields around the rotor, inflow distributions on the rotor disc and behaviors of blade flapping motion are discussed. It is also clarified the cause that the helicopter rotor hovering in close proximity to the ground with a wall does not have the enough ground effect depending on the combinations of these parameters.

  8. Proximal arm kinematics affect grip force-load force coordination

    OpenAIRE

    Vermillion, Billy C.; Lum, Peter S; Lee, Sang Wook

    2015-01-01

    During object manipulation, grip force is coordinated with load force, which is primarily determined by object kinematics. Proximal arm kinematics may affect grip force control, as proximal segment motion could affect control of distal hand muscles via biomechanical and/or neural pathways. The aim of this study was to investigate the impact of proximal kinematics on grip force modulation during object manipulation. Fifteen subjects performed three vertical lifting tasks that involved distinct...

  9. The Safety of Using Proximal Anteromedial Portals in Elbow Arthroscopy With Prior Ulnar Nerve Transposition.

    Science.gov (United States)

    Park, Sang-Eun; Bachman, Daniel R; O'Driscoll, Shawn W

    2016-06-01

    To report the safety of using the proximal anteromedial portal, using a simplified ulnar nerve management strategy derived from an earlier study, in a series of patients with previously transposed ulnar nerves. A retrospective review of all elbow arthroscopies performed by a single surgeon from 2009 to 2014 was performed. The following techniques were used if, by palpation, localization of the ulnar nerve was considered to be certain (group 1) or uncertain (group 2): In group 1 (certain) the proximal anteromedial portal was established in the normal antegrade fashion. In group 2 (uncertain) a 1- to 3-cm incision was made at the planned proximal anteromedial portal site, and blunt dissection down to the capsule was performed without identification of the nerve. The nerve was not visualized but sometimes was palpated through the wound to confirm its location anteriorly or posteriorly. If there was a disparity between the prior operative records and the physical examination findings, the nerve was explored through a 3- to 4-cm incision. We reviewed 394 elbow arthroscopy cases, 22 of which had a prior transposed ulnar nerve (21 subcutaneous and 1 submuscular) that required anterior-compartment arthroscopic surgery. Group 1 (certain location) consisted of 9 elbows (41%), whereas group 2 (uncertain location) consisted of 13 (59%). In 2 cases in group 2, the ulnar nerve was explored because of the disparity between the previous medical records and the physical examination findings. There were no operative ulnar nerve injuries related to the use of the proximal anteromedial portal. The proximal anteromedial portal was able to be used safely in patients with prior transposition of the ulnar nerve. This was achieved by using an algorithm based on the degree of certainty with which the nerve can be localized in the region of the planned portal by clinical palpation. Level IV, therapeutic case series. Copyright © 2016 Arthroscopy Association of North America. All rights

  10. Prognostic Factors for Patients after Curative Resection for Proximal Gastric Cancer

    Institute of Scientific and Technical Information of China (English)

    赵东晖; 徐惠绵; 李凯; 孙哲

    2010-01-01

    The factors influencing the long-term survival of patients with proximal gastric cancer (PGC) after curative resection were investigated. Data from 171 patients who underwent curative resection for PGC were retrospectively analyzed. The patients were grouped according to the clinicopathological factors and operative procedures. The tumor depth (T stage) and lymph node metastasis (pN stage) were graded according to the fifth edition of TNM Staging System published by UICC in 1997. The metastatic lymph node r...

  11. 多无人机交会过程的协同航迹规划方法%Cooperative Path Planning for Rendezvous of Unmanned Aerial Vehicles

    Institute of Scientific and Technical Information of China (English)

    孙小雷; 孟宇麟; 齐乃明; 姚蔚然

    2015-01-01

    交会过程是多无人机(UAV)协同控制的重要组成部分,为此提出一种无人机恒速飞行交会过程的协同航迹规划方法.为兼顾航迹较短的迂回机动和航迹较长的盘旋机动方式,无人机实时计算至目标的最小机动距离,生成最短Dubins路径作为航迹参考.近程无人机在其基础上重新规划生成等待机动航迹,补偿与远程无人机的航程差.远程无人机同样根据该过程调整航迹,实现同时到达对目标的可攻击范围.无人机在该范围内沿Dubins路径飞行,以最小化执行时间,降低风险.仿真结果表明,所规划的协同航迹可实现无人机在目标可攻击范围的交会,同时控制规律容易实现,验证了算法的可行性和有效性.%Rendezvous is an important process of cooperative control for unmanned aerial vehicles (UAVs). Thus this paper investigates a cooperative path planning for rendezvous of UAVs with constant speed. To achieve both wandering maneuver with shorter range-to-go and circle maneuver with longer range-to-go, UAVs calculate the minimum maneuver distance to target in real time in order to plan a Dubins path as a reference. Based on this path, the UAV with shorter range-to-go re-plans the waiting maneuver to extend the path length. In addition, as the UAV with longer range-to-go also follows this manner, the UAVs will arrive at the boundary of the target execution range at the same time. To reduce the risk of collision in this range, the UAVs fly along the Dubins path to minimize the execution time. The simulation results show that the UAVs can perform cooperative path planning for rendezvous in target execution range by using the proposed method, and it is easy to implement the corresponding control law, which demonstrates the feasibility and effectiveness of the method.

  12. Prognostic impact of splenectomy on advanced proximal gastric cancer with No.10 lymph node metastasis

    Institute of Scientific and Technical Information of China (English)

    HUANG Chang-ming; WANG Jia-bin; LU Hui-shan; ZHENG Chao-hui; LI Ping; XIE Jian-wei; ZHANG Xiang-fu

    2009-01-01

    Background This study evaluated the prognostic impact of D2 lymphadenectomy combined with splenectomy in patients with advanced proximal gastric cancer and lymph node metastasis at the splenic hilum (No. 10 lymph nodes).Methods The clinical records of 216 patients with advanced proximal gastric cancer and No.10 lymph node metastasis who underwent D2 curative resection were retrospectively analyzed. Seventy-three patients underwent simultaneous splenectomy (splenectomy group), while 143 patients did not (spleen-preserving group). Five-year survival rates, mean numbers of dissected No.10 lymph nodes and metastatic No.10 lymph nodes, and operative morbidity and mortality were calculated and compared between the two groups. Potential prognostic factors were evaluated by univariate and multivariate analysis.Results The 5-year survival rate was 30.0% for the splenectomy group and 19.7% for the spleen-preserving group (X~2=14.73, P 0.05).Conclusions Splenectomy is beneficial for No.10 lymph node dissection in patients with advanced proximal gastric cancer. To improve patient prognosis, total gastrectomy with splenectomy is recommended for patients with T3 proximal gastric cancer who have No. 10 lymph node metastasis.

  13. Proximal spinal muscular atrophy: current orthopedic perspective

    Directory of Open Access Journals (Sweden)

    Haaker G

    2013-11-01

    Full Text Available Gerrit Haaker, Albert Fujak Department of Orthopaedic Surgery, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany Abstract: Spinal muscular atrophy (SMA is a hereditary neuromuscular disease of lower motor neurons that is caused by a defective "survival motor neuron" (SMN protein that is mainly associated with proximal progressive muscle weakness and atrophy. Although SMA involves a wide range of disease severity and a high mortality and morbidity rate, recent advances in multidisciplinary supportive care have enhanced quality of life and life expectancy. Active research for possible treatment options has become possible since the disease-causing gene defect was identified in 1995. Nevertheless, a causal therapy is not available at present, and therapeutic management of SMA remains challenging; the prolonged survival is increasing, especially orthopedic, respiratory and nutritive problems. This review focuses on orthopedic management of the disease, with discussion of key aspects that include scoliosis, muscular contractures, hip joint disorders, fractures, technical devices, and a comparative approach of conservative and surgical treatment. Also emphasized are associated complications including respiratory involvement, perioperative care and anesthesia, nutrition problems, and rehabilitation. The SMA disease course can be greatly improved with adequate therapy with established orthopedic procedures in a multidisciplinary therapeutic approach. Keywords: spinal muscular atrophy, scoliosis, contractures, fractures, lung function, treatment, rehabilitation, surgery, ventilation, nutrition, perioperative management

  14. Proximity effects in cold atom artificial graphene

    CERN Document Server

    Grass, Tobias; Tarruell, Leticia; Pellegrini, Vittorio; Lewenstein, Maciej

    2016-01-01

    Cold atoms in an optical lattice with brick-wall geometry have been used to mimic graphene, a two-dimensional material with characteristic Dirac excitations. Here we propose to bring such artificial graphene into the proximity of a second atomic layer with a square lattice geometry. For non-interacting fermions, we find that such bilayer system undergoes a phase transition from a graphene-like semi-metal phase, characterized by a band structure with Dirac points, to a gapped band insulator phase. In the presence of attractive interactions between fermions with pseudospin-1/2 degree of freedom, a competition between semi-metal and superfluid behavior is found at the mean-field level. Upon tuning the coupling between the layers, the system exhibits re-entrant superfluid phases. Using the quantum Monte Carlo method, we also investigate the case of strong repulsive interactions. In the Mott phase, each layer exhibits a different amount of long-range magnetic order. Upon coupling both layers, a valence-bond crysta...

  15. Imaging of rectus femoris proximal tendinopathies

    Energy Technology Data Exchange (ETDEWEB)

    Pesquer, Lionel; Poussange, Nicolas; Meyer, Philippe; Dallaudiere, Benjamin; Feldis, Matthieu [Clinique du Sport de Bordeaux, Centre d' Imagerie Osteo-articulaire, Merignac (France); Sonnery-Cottet, Bertrand [Groupe Ramsay Generale de Sante - Hopital Prive Jean Mermoz, Centre Orthopedique Santy, Lyon (France); Graveleau, Nicolas [Clinique du Sport de Bordeaux, Centre de Chirurgie Orthopedique et Sportive, Merignac (France)

    2016-07-15

    The rectus femoris is the most commonly injured muscle of the anterior thigh among athletes, especially soccer players. Although the injury pattern of the muscle belly is well documented, less is known about the anatomy and specific lesions of the proximal tendons. For each head, three distinctive patterns may be encountered according to the location of the injury, which can be at the enthesis, within the tendon, or at the musculotendinous junction. In children, injuries correspond most commonly to avulsion of the anteroinferior iliac spine from the direct head and can lead to subspine impingement. Calcific tendinitis and traumatic tears may be encountered in adults. Recent studies have shown that traumatic injuries of the indirect head may be underdiagnosed and that injuries of both heads may have a surgical issue. Finally, in the case of tears, functional outcome and treatment may vary if the rupture involves one or both tendons and if the tear is partial or complete. Thus, it is mandatory for the radiologist to know the different ultrasound and magnetic resonance imaging (MRI) patterns of these lesions in order to provide accurate diagnosis and treatment. The purpose of this article is to recall the anatomy of the two heads of rectus femoris, describe a reliable method of assessment with ultrasound and MRI and know the main injury patterns, through our own experience and literature review. (orig.)

  16. Proximity Resonance and Localized Surface Plasmons

    Science.gov (United States)

    Liu, Bo; Heller, Eric

    2014-03-01

    The collective excitation of conduction electrons in subwavelength nanostructures is known as Localized Surface Plasmon(LSP)[1]. Such plasmon modes has been intensively studied using noble nanoparticles . More recently, the possibility of building terahertz metamaterials supporting such LSP modes has been explored in graphene microribbons and microdisks. Unlike Surface Plasmon Polaritons(SPPs) at metal-insulator interface, LSP can be directly excited by light illumination and holds promise for applications in ultrasensitive biosensing, nano-optical tweezers and improved photovoltaic devices. In this paper, we consider the interaction of two LSPs in the weak coupling regime and show how an effect similar to the proximity resonance in the quantum scattering theory) gives rise to an asymmetric(quadrupole) mode with increased damping rate. The existence of this asymmetric mode relies on a small phase retardation between the two LSPs. This phase retardation, though small, is key to both increased damping rate for the asymmetric mode and reduced damping rate for the symmetric mode. When this small phase retardation is removed by changing the polarization of the exciting light,we show that the asymmetric mode can not be excited and the symmetric mode shows increased damping.

  17. Proximate and elemental analysis of infant formula.

    Science.gov (United States)

    Tanner, J T

    1982-11-01

    The Nutrient Surveillance Branch has been conducting a survey of infant formula products for Fiscal Year 1981. Each product has been carefully analyzed and the results compared to the label declaration and the minimum-maximum limits specified by the American Academy of Pediatrics' Committee on Nutrition (CON/AAP). Proximate and elemental analyses were made. Protein, fat, ash, and total solids (moisture) were determined by AOAC methods. Osmolality, density, and fatty acids (linoleic) were also determined. Carbohydrates were calculated by difference and caloric content was calculated by using the general Atwater factors. Elemental analysis for Ca, P, Mg, Fe, Zn, Cu, Mn, Na, and K were performed by induction coupled plasma absorption spectroscopy. Chloride was assayed by potentiometric titration with AgNO3. A summary of the findings from the infant formula survey have been compared with CON/AAP recommendations. In general, there were only a few exceptions where the label claims and the CON/AAP requirements were not met. However, in none of these cases was the difference considered to be of public health significance.

  18. Methods for the proximate analysis of peat

    Energy Technology Data Exchange (ETDEWEB)

    Sheppard, J.D.; Tibbetts, T.E.; Forgeron, D.W.

    1986-01-01

    An investigation was conducted into methods for determining the percentages of volatile matter and ash in peat. Experiments were performed on two types of sphagnum peat, a decomposed fuel peat and a commercial horticultural grade peat. The heating apparatus consisted of both a standard programmable furnace (Fisher Coal Analyser) and a thermogravimetric analyser with a module for differential scanning calorimetry (Mettler TA 3000 system). The results indicate that the seven minute test for volatile matter at either 900 C or 950 C does not fully differentiate volatiles from fixed carbon and, depending on the degree of decomposition, up to sixty minutes at 900 C may be required. The TGA system is very useful in discriminating between different fractions of volatile matter. The relative fractions are more important in determining burning characteristics than the total percentage of volatiles. Ashing must be performed under conditions sufficiently severe to ensure complete combustion of organics. The severity that is required is mainly dependent on the degree of decomposition and sample size. Use of TGA and DSC for studying the combustion of peat provides much more information than the standard proximate analysis. 14 refs.

  19. Proximal relationships between PTSD and drinking behavior

    Directory of Open Access Journals (Sweden)

    Debra Kaysen

    2014-12-01

    Full Text Available Co-morbid PTSD and alcohol use disorders are both common and debilitating. However, many of these studies rely on cross-sectional studies that obscure more complex relationships between PTSD and drinking. Event-level studies allow for examination of proximal relationships between PTSD and drinking. Among women (n=136 with past sexual victimization, n=40 no past trauma history, a two-part mixed hurdle model was used to examine daily PTSD and drinking. On days women experienced more intrusive and behavioral avoidance symptoms, they were more likely to drink. For a 2 SD increase in symptoms, there was a 5% increased likelihood of drinking, and for a 2 SD increase in dysphoric symptoms or negative affect, women drank approximately half drink less. Daily-level coping self-efficacy moderated the association between distress and drinking (IRR=0.91, p<0.01. Women who reported less coping drank more as their distress increased on a certain day whereas women who reported more coping drank about the same regardless of distress. Overall, findings suggest that specific PTSD symptoms are associated with higher alcohol use and that these relationships are moderated by daily coping self-efficacy. Implications of these findings for informing models of PTSD/AUD comorbidity, as well as clinical implications will be discussed.

  20. Proximity effects in cold atom artificial graphene

    Science.gov (United States)

    Graß, Tobias; Chhajlany, Ravindra W.; Tarruell, Leticia; Pellegrini, Vittorio; Lewenstein, Maciej

    2017-03-01

    Cold atoms in an optical lattice with brick-wall geometry have been used to mimic graphene, a two-dimensional material with characteristic Dirac excitations. Here we propose to bring such artificial graphene into the proximity of a second atomic layer with a square lattice geometry. For non-interacting fermions, we find that such bilayer system undergoes a phase transition from a graphene-like semi-metal phase, characterized by a band structure with Dirac points, to a gapped band insulator phase. In the presence of attractive interactions between fermions with pseudospin-1/2 degree of freedom, a competition between semi-metal and superfluid behavior is found at the mean-field level. Using the quantum Monte Carlo method, we also investigate the case of strong repulsive interactions. In the Mott phase, each layer exhibits a different amount of long-range magnetic order. Upon coupling both layers, a valence-bond crystal is formed at a critical coupling strength. Finally, we discuss how these bilayer systems could be realized in existing cold atom experiments.

  1. Semiconductor detectors with proximity signal readout

    Energy Technology Data Exchange (ETDEWEB)

    Asztalos, Stephen J. [XIA, LLC, Hayward, CA (United States)

    2014-01-30

    Semiconductor-based radiation detectors are routinely used for the detection, imaging, and spectroscopy of x-rays, gamma rays, and charged particles for applications in the areas of nuclear and medical physics, astrophysics, environmental remediation, nuclear nonproliferation, and homeland security. Detectors used for imaging and particle tracking are more complex in that they typically must also measure the location of the radiation interaction in addition to the deposited energy. In such detectors, the position measurement is often achieved by dividing or segmenting the electrodes into many strips or pixels and then reading out the signals from all of the electrode segments. Fine electrode segmentation is problematic for many of the standard semiconductor detector technologies. Clearly there is a need for a semiconductor-based radiation detector technology that can achieve fine position resolution while maintaining the excellent energy resolution intrinsic to semiconductor detectors, can be fabricated through simple processes, does not require complex electrical interconnections to the detector, and can reduce the number of required channels of readout electronics. Proximity electrode signal readout (PESR), in which the electrodes are not in physical contact with the detector surface, satisfies this need.

  2. Proximate and mineral composition of industrialized biscuits

    Directory of Open Access Journals (Sweden)

    Maria Eliza Assis dos Passos

    2013-06-01

    Full Text Available The aim of this study was to analyze the proximate and mineral composition of 21 types of biscuits. All biscuits showed high fat contents, significantly different (P < 0.05 from those described on the labels, except for three brands. Insoluble fiber fractions were predominant in the analyzed samples. Among the 21 biscuits analyzed, 16 showed food label values 20% higher than those allowed by law, according to RDC 360, for fat, protein, total fiber, calcium, and sodium levels. This difference reached 273% for the sodium content. The calcium content was included only on the label of three samples analyzed, and the values described were significantly lower than those obtained analytically. Considering that biscuits are consumed by people of all age groups and of different socioeconomic levels, the results can contribute to the plans for health policies, such as surveillance of nutritional labeling, ensuring the reliability of the information provided by the food industry and enabling the identification of the relationship between dietary factors and the occurrence of non-transmissible chronic diseases.

  3. Quasar Proximity Zones and Patchy Reionization

    CERN Document Server

    Lidz, A; Zaldarriaga, M; Hernquist, L; Dutta, S; Lidz, Adam; Quinn, Matthew Mc; Zaldarriaga, Matias; Hernquist, Lars; Dutta, Suvendra

    2007-01-01

    Lyman-alpha forest absorption spectra towards quasars at z ~ 6 show regions of enhanced transmission close to their source. Several authors have argued that the apparently small sizes of these regions indicate that quasar ionization fronts at z >~ 6 expand into a largely or partly neutral intergalactic medium (IGM). Assuming that the typical region in the IGM is reionized by z <= 6, as is suggested by Ly-a forest observations, we argue that at {\\em least} 50% of the volume of the IGM was reionized before the highest redshift quasars turned on. Further, even if the IGM is as much as 50% neutral at quasar turn-on, the quasars are likely born into large galaxy-generated HII regions. The HII regions during reionization are themselves clustered, and using radiative transfer simulations, we find that long skewers through the IGM towards quasar progenitor halos pass entirely through ionized bubbles, even when the IGM is half neutral. These effects have been neglected in most previous analyses of quasar proximity ...

  4. 43 CFR 23.5 - Technical examination of prospective surface exploration and mining operations.

    Science.gov (United States)

    2010-10-01

    ... mining operations vary widely with respect to topography, climate, surrounding land uses, proximity to densely used areas, and other environmental influences and that mining and reclamation requirements should...

  5. Proximity and inter-organizational collaboration: a literature review

    NARCIS (Netherlands)

    Knoben, J.; Oerlemans, L.A.G.

    2006-01-01

    The proximity concept is used in many different ways in the literature. These dimensions of proximity are, however, defined and measured in many different (sometimes even contradictory) ways, show large amounts of overlap, and often are under- or over-specified. The goal of this paper is to specify

  6. Comparative studies for different proximity potentials applied to α decay

    Energy Technology Data Exchange (ETDEWEB)

    Yao, Y.J.; Zhang, G.L. [Beihang University, School of Physics and Nuclear Energy Engineering, Beijing (China); Beihang University, International Research Center for Nuclei and Particles in the Cosmos, Beijing (China); Qu, W.W. [Medical College of Soochow University, School of Radiation Medicine and Protection, Soochow (China); Qian, J.Q. [Beihang University, School of Physics and Nuclear Energy Engineering, Beijing (China)

    2015-09-15

    Half-lives of α decay of even-even nuclei calculated by using fourteen different versions of proximity potentials are compared to experimental data. The results show that the results of the generalized proximity potential 1977 are very much in agreement with the experimental data. In comparison with the distributions of nuclear potentials at small distances and the distributions of total potentials above the released energy Q{sub α}, it is found that at small distances the distributions of nuclear potentials have large difference and the distributions of total potentials are different among the listed proximity potentials. The different potential distributions affect the penetration probability of α, which is related to the half-life of the α decay for each nucleus. The generalized proximity potential 1977 is also used to calculate the half-lives of α decay of nuclei with odd mass numbers. The results show that the generalized proximity potential 1977 can calculate the half-lives of the α decay of almost all nuclei, which underlines and supports the use of the generalized proximity potential 1977 by Santhosh et al. in the Coulomb and proximity potential model (CPPM) and the Coulomb and proximity potential model for deformed nuclei (CPPMDN). (orig.)

  7. Comparative studies for different proximity potentials applied to α decay

    Science.gov (United States)

    Yao, Y. J.; Zhang, G. L.; Qu, W. W.; Qian, J. Q.

    2015-09-01

    Half-lives of α decay of even-even nuclei calculated by using fourteen different versions of proximity potentials are compared to experimental data. The results show that the results of the generalized proximity potential 1977 are very much in agreement with the experimental data. In comparison with the distributions of nuclear potentials at small distances and the distributions of total potentials above the released energy Q α , it is found that at small distances the distributions of nuclear potentials have large difference and the distributions of total potentials are different among the listed proximity potentials. The different potential distributions affect the penetration probability of α, which is related to the half-life of the α decay for each nucleus. The generalized proximity potential 1977 is also used to calculate the half-lives of α decay of nuclei with odd mass numbers. The results show that the generalized proximity potential 1977 can calculate the half-lives of the α decay of almost all nuclei, which underlines and supports the use of the generalized proximity potential 1977 by Santhosh et al. in the Coulomb and proximity potential model (CPPM) and the Coulomb and proximity potential model for deformed nuclei (CPPMDN).

  8. Cast index in predicting outcome of proximal pediatric forearm fractures

    Directory of Open Access Journals (Sweden)

    Hassaan Qaiser Sheikh

    2015-01-01

    Conclusion: Cast index is useful in predicting redisplacement of manipulated distal forearm fractures. We found that in proximal half forearm fractures it is difficult to achieve a CI of <0.8, but increased CI does not predict loss of position in these fractures. We therefore discourage the use of CI in proximal half forearm fractures.

  9. Analysis of pattern density on process proximity compensation

    Science.gov (United States)

    Jung, Sunwook; Lo, Fred; Yang, Tien-Chu; Yang, Ta-Hong; Chen, Kuang-Chao; Lu, Chih-Yuan

    2007-03-01

    The challenges of ever-smaller CD (Critical Dimension) budget for advanced memory product requires tight ACLV (Across-Chip Line-width Variation) control. In addition to the lithographic MOPC (Model-based Optical Proximity Correction) for DCD (photo CD) control, the process correction for etch proximity effect can no longer be ignored. To meet on our requirement on final CD accuracy for critical layer, a set of test pattern, that represents memory array in one of our critical layers, has been generated for both photo and etch process characterizations. Through the combination of different pattern-coverage areas in the test mask and wafer map design, various local (chip-level) pattern densities of 40%~70% and global (wafer-level) pattern densities of 35%~65% were achieved for optical and etch proximity study. The key contributors to the process proximity effect were identified and voluminous data has been extracted from the memory block like patterns for statistical analysis. The photo and etch proximity effects were hence modeled as function of memory block separation, local pattern density as well as global pattern density. Finally, the respective photo and etch proximity effects through model-based proximity correction and rule-based proximity correction were applied in a multi-step flow to products.

  10. Proximity approach to problems in topology and analysis

    CERN Document Server

    Naimpally, Somashekhar

    2009-01-01

    Dieses Buch konzentriert das aktuelle Gesamtwissen zum Proximity-Konzept und stellt es dem Leser in gut strukturierter Form dar. Hauptaugenmerk liegt auf den vielfältigen Möglichkeiten, die sich aus dem Proximity-Konzept der räumlichen Nähe und seiner Verallgemeinerung im Nearness-Konzept ergeben.

  11. Management of proximal humeral fractures in the nineteenth century

    DEFF Research Database (Denmark)

    Brorson, Stig

    2011-01-01

    The diagnosis and treatment of fractures of the proximal humerus have troubled patients and medical practitioners since antiquity. Preradiographic diagnosis relied on surface anatomy, pain localization, crepitus, and impaired function. During the nineteenth century, a more thorough understanding...... of the pathoanatomy and pathophysiology of proximal humeral fractures was obtained, and new methods of reduction and bandaging were developed....

  12. [Kapandji intramedullary wire osteosynthesis in proximal humeral fractures].

    Science.gov (United States)

    Werner, A; Böhm, D; Ilg, A; Gohlke, F

    2002-04-01

    For operative treatment of proximal humeral fractures minimal invasive techniques reduce the risk of iatrogenic damage of blood supply and periarticular scarring. Reported preliminary results are encouraging. We present our experience achieved with an intramedullary wire fixation adapted from a report of Kapandji in 1989. Between 3/95 and 6/00 29 patients were treated with this technique at our institution. All received early functional treatment. 14 patients (average mean age 56 years at time of trauma) who had a minimum follow up of 24 months (mean 36.4 months) and therefore allowed a preliminary conclusion regarding avascular head necrosis (AVN) were reexamined by use of the Constant Score and x-ray. We examined three unstable 2-part, four 3-part and seven 4-part fractures (5 of them valgus-impacted). The mean Constant Score at follow up was 70 points (31-86 points). We saw one total collapse of the humeral head because of AVN. In one patient the distal end of the wires led to a skin irritation and had to be shortened. We observed no secondary fragment displacement or non-unions. In our hands, this technique offers good results, even in valgus-impacted 4-part fractures of the elderly and allows internal fixation in little displaced but unstable fractures with the benefit of early functional treatment instead of longer immobilization. Based on the experience with intramedullary wiring the previously performed technique using threading wires was abandoned and the indication for primary arthroplasty considerably influenced.

  13. Development of procedures for programmable proximity aperture lithography

    Energy Technology Data Exchange (ETDEWEB)

    Whitlow, H.J., E-mail: harry.whitlow@he-arc.ch [Institut des Microtechnologies Appliquées Arc, Haute Ecole Arc Ingénierie, Eplatures-Grise 17, CH-2300 La Chaux-de-Fonds (Switzerland); Department of Physics, University of Jyväskylä, P.O. Box 35 (YFL), FI-40014 Jyväskylä (Finland); Gorelick, S. [VTT Technical Research Centre of Finland, P.O. Box 1000, Tietotie 3, Espoo, FI-02044 VTT (Finland); Puttaraksa, N. [Department of Physics, University of Jyväskylä, P.O. Box 35 (YFL), FI-40014 Jyväskylä (Finland); Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Napari, M.; Hokkanen, M.J.; Norarat, R. [Department of Physics, University of Jyväskylä, P.O. Box 35 (YFL), FI-40014 Jyväskylä (Finland)

    2013-07-01

    Programmable proximity aperture lithography (PPAL) with MeV ions has been used in Jyväskylä and Chiang Mai universities for a number of years. Here we describe a number of innovations and procedures that have been incorporated into the LabView-based software. The basic operation involves the coordination of the beam blanker and five motor-actuated translators with high accuracy, close to the minimum step size with proper anti-collision algorithms. By using special approaches, such writing calibration patterns, linearisation of position and careful backlash correction the absolute accuracy of the aperture size and position, can be improved beyond the standard afforded by the repeatability of the translator end-point switches. Another area of consideration has been the fluence control procedures. These involve control of the uniformity of the beam where different approaches for fluence measurement such as simultaneous aperture current and the ion current passing through the aperture using a Faraday cup are used. Microfluidic patterns may contain many elements that make-up mixing sections, reaction chambers, separation columns and fluid reservoirs. To facilitate conception and planning we have implemented a .svg file interpreter, that allows the use of scalable vector graphics files produced by standard drawing software for generation of patterns made up of rectangular elements.

  14. Proximal femoral epiphysiolysis during reduction of hip dislocation in adolescents.

    Science.gov (United States)

    Herrera-Soto, Jose Antonio; Price, Charles T; Reuss, Bryan L; Riley, Patrick; Kasser, James R; Beaty, James H

    2006-01-01

    Traumatic hip dislocation is an uncommon injury in children. The urgency of closed reduction to prevent possible osteonecrosis may present some pitfalls. Adolescents with open proximal femoral physis may have sustained trauma to the physis at the time of dislocation that can lead to displacement of the epiphysis during the reduction maneuver. The purpose of this study is to report 5 cases with this complication and discuss potential etiology and management. All of the 5 patients were between 12 and 16 years old and underwent closed reduction under conscious sedation. Epiphysiolysis of the femoral head was diagnosed after reduction in all 5 patients. Every patient underwent emergent open reduction and internal fixation of the femur and open hip reduction. Avascular necrosis was identified in all 5 patients within 3 to 15 months postinjury. If there is any suspicion of associated physeal injury or if there is any physeal instability noted under fluoroscopy, an open reduction is recommended in the operating room under radiograph guidance to prevent displacement.

  15. Influence of different isolation methods on the survival of proximal ART restorations in primary molars after two years

    NARCIS (Netherlands)

    A.M. Kemoli; W.E. van Amerongen; G.N. Opinya

    2010-01-01

    AIM: This was to evaluate the influence of two methods of tooth-isolation on the survival rate of proximal ART restorations in the primary molars. METHODS: The study was conducted in two rural divisions in Kenya, with 7 operators randomly paired to a group of 8 assistants. A total of 804 children ea

  16. Nanocrystal Bioassembly: Asymmetry, Proximity, and Enzymatic Manipulation

    Energy Technology Data Exchange (ETDEWEB)

    Claridge, Shelley A. [Univ. of California, Berkeley, CA (United States)

    2008-05-01

    Research at the interface between biomolecules and inorganic nanocrystals has resulted in a great number of new discoveries. In part this arises from the synergistic duality of the system: biomolecules may act as self-assembly agents for organizing inorganic nanocrystals into functional materials; alternatively, nanocrystals may act as microscopic or spectroscopic labels for elucidating the behavior of complex biomolecular systems. However, success in either of these functions relies heavily uponthe ability to control the conjugation and assembly processes.In the work presented here, we first design a branched DNA scaffold which allows hybridization of DNA-nanocrystal monoconjugates to form discrete assemblies. Importantly, the asymmetry of the branched scaffold allows the formation of asymmetric2assemblies of nanocrystals. In the context of a self-assembled device, this can be considered a step toward the ability to engineer functionally distinct inputs and outputs.Next we develop an anion-exchange high performance liquid chromatography purification method which allows large gold nanocrystals attached to single strands of very short DNA to be purified. When two such complementary conjugates are hybridized, the large nanocrystals are brought into close proximity, allowing their plasmon resonances to couple. Such plasmon-coupled constructs are of interest both as optical interconnects for nanoscale devices and as `plasmon ruler? biomolecular probes.We then present an enzymatic ligation strategy for creating multi-nanoparticle building blocks for self-assembly. In constructing a nanoscale device, such a strategy would allow pre-assembly and purification of components; these constructs can also act as multi-label probes of single-stranded DNA conformational dynamics. Finally we demonstrate a simple proof-of-concept of a nanoparticle analog of the polymerase chain reaction.

  17. Video Guidance Sensor for Surface Mobility Operations

    Science.gov (United States)

    Fernandez, Kenneth R.; Fischer, Richard; Bryan, Thomas; Howell, Joe; Howard, Ricky; Peters, Bruce

    2008-01-01

    Robotic systems and surface mobility will play an increased role in future exploration missions. Unlike the LRV during Apollo era which was an astronaut piloted vehicle future systems will include teleoperated and semi-autonomous operations. The tasks given to these vehicles will run the range from infrastructure maintenance, ISRU, and construction to name a few. A common task that may be performed would be the retrieval and deployment of trailer mounted equipment. Operational scenarios may require these operations to be performed remotely via a teleoperated mode,or semi-autonomously. This presentation describes the on-going project to adapt the Automated Rendezvous and Capture (AR&C) sensor developed at the Marshall Space Flight Center for use in an automated trailer pick-up and deployment operation. The sensor which has been successfully demonstrated on-orbit has been mounted on an iRobot/John Deere RGATOR autonomous vehicle for this demonstration which will be completed in the March 2008 time-frame.

  18. Minimal invasive long PHILOS®-plate osteosynthesis in metadiaphyseal fractures of the proximal humerus.

    Science.gov (United States)

    Rancan, Mario; Dietrich, Michael; Lamdark, Tenzin; Can, Uenal; Platz, Andreas

    2010-12-01

    Minimal invasive plate osteosynthesis (MIPO) not only meets the criteria of a "biological" osteosynthesis by minimising invasivity as well as iatrogenic soft tissue damage, but can also provide adequate stability for fracture healing and early functional aftertreatment. Up to date, only few publications report on MIPO of humeral shaft fractures mainly using the anterolateral deltopectoral approach for proximal plate insertion. Objective of the present study was to assess the feasibility and clinical outcome of MIPO for metadiaphyseal fractures of the proximal humerus through a lateral approach using angular stable long PHILOS(®)-plates. We retrospectively evaluated 29 patients (mean age 77 years, range 48-95 years) with displaced metadiaphyseal fractures of the proximal humerus treated with MIPO technique. For the first time, an angular stable long PHILOS(®)-plate through a lateral deltoid-split approach proximally and a brachialis/brachioradialis intermuscular approach with exposure of the radial nerve distally, were used. There were no infections and no iatrogenic injuries to the axillary and radial nerve. One patient showed subacromial impingement and one patient had to be reoperated for redislocation of the distal fragment with screw breakage, which was most likely due to incorrect screw placement. This patient was successfully operated using the same method and implant. Besides one patient who refused further follow-up, 28 patients could be followed up to a mean of 8 months (range 3-12 months) each with an entirely healed fracture. Furthermore, patient's quality of life was documented using the SF-36 questionnaire. Comparison with published United States normative data showed no significant deficits in the physical as well as in the mental domains 8 months after MIPO. Minimal invasive long PHILOS(®)-plate osteosynthesis using a combined lateral deltoid-split and brachialis/brachioradialis intermuscular approach proved to be a safe procedure for the

  19. The outcome of patients sustaining a proximal femur fracture who suffer from alcohol dependency.

    Science.gov (United States)

    Faroug, R; Amanat, S; Ockendon, M; Shah, S V; Gregory, J J

    2014-07-01

    There are many negative health consequences associated with alcohol dependency. Fractures of the proximal femur carry significant morbidity and mortality. This study examines the outcomes in patients with alcohol dependency, who sustain a fracture of the proximal femur. Twenty-eight consecutive alcohol dependent patients who suffered a fracture of the proximal femur were identified over a three year period. Data were collected on demographics, co-morbidity, surgical factors, mobility and mortality. The median age of patients was 61 years. The median weekly alcohol intake was 158 units. Thirteen patients sustained an extra-capsular fracture and 15 an intra-capsular proximal femoral fracture. Twenty-two fractures were treated with internal fixation and six with arthroplasty. The overall mortality rate was 29% at a median of 15 months post fracture. The failure rate of intra-capsular fractures fixed with cannulated screws was 56% at a median time of 43 days. All patients had a reduction in mobility compared to their pre-operative function. The reduction in mobility was greatest in patients with intra-capsular fractures treated with cannulated screw fixation. Alcohol dependent patients sustaining a fracture of the proximal femur are significantly younger than non-alcohol dependent patients sustaining the same injury. Despite the younger age at presentation the one year mortality rate of this group was high (29%). The high rate of complications with fracture fixation and high one year mortality suggest that hemiarthroplasty may be the best treatment option for intra-capsular fractures in this patient group.

  20. The Role of a Primary Arthroplasty in the Treatment of Proximal Tibia Fractures in Orthogeriatric Patients

    Directory of Open Access Journals (Sweden)

    Thomas Haufe

    2016-01-01

    Full Text Available The total knee arthroplasty (TKA is the gold standard for patients with an advanced symptomatic gonarthrosis. However, there are very few publications dealing with the primary TKA for patients with a proximal tibia fracture. In our retrospective study we evaluated 30 patients treated with a TKA for a proximal tibia fracture in our institution between 01/2008 and 12/2014. We collected the following statistical data from each patient: age, classification of the fracture (AO-classification, type of prosthesis used, length of the operation and hospitalization, and complications during the follow-up. We used the Knee Society Score (KSS and the WOMAC score to evaluate the function. The Knee Society Score showed an average “general knee score” (KSS1 of 81.1 points and an average “functional knee score” (KSS2 of 74.5 points. The average WOMAC score was 78.6 points. Immediate postoperative mobilization with the possibility of a full-weight bearing is of crucial importance for the geriatric patients to maintain the mobility they had prior to the operation and reduce medical complications. Because of these advantages, the primary TKA seems to be a promising alternative to the ORIF of a proximal tibia fracture in the orthogeriatric patient.

  1. Numerical Optimization of the Position in Femoral Head of Proximal Locking Screws of Proximal Femoral Nail System; Biomechanical Study.

    Science.gov (United States)

    Konya, Mehmet Nuri; Verim, Özgür

    2017-09-29

    Proximal femoral fracture rates are increasing due to osteoporosis and traffic accidents. Proximal femoral nails are routinely used in the treatment of these fractures in the proximal femur. To compare various combinations and to determine the ideal proximal lag screw position in pertrochanteric fractures (Arbeitsgemeinschaft für Osteosynthesefragen classification 31-A1) of the femur by using optimized finite element analysis. Biomechanical study. Computed tomography images of patients' right femurs were processed with Mimics. Afterwards a solid femur model was created with SolidWorks 2015 and transferred to ANSYS Workbench 16.0 for response surface optimization analysis which was carried out according to anterior-posterior (-10°0) and posterior-anterior directions of the femur neck significantly increased these stresses. The most suitable position of the proximal lag screw was confirmed as the middle of the femoral neck by using optimized finite element analysis.

  2. Management of the proximal tibia fractures by mini external fixation: A case series of 30 cases

    Directory of Open Access Journals (Sweden)

    Samar K Biswas

    2014-01-01

    Full Text Available Background: Management of high velocity trauma is a challenging problem because of morbidity of trauma and sometime residual problems of failure of proper healing of fractures with the restriction of movements of knee, shortening, and added risk of compartment syndrome in the proximal tibia fracture. There is always risk of post-operative infection and infected non-union in extensive open surgical procedure and internal fixation. Hence, there is always look out for the middle path procedure for a solution to the above said problems with the added advantage of less hospital stay and early return to work by minimal invasive procedure and stabilization of fracture reduction by multiple K-wire fixation with a frame applied externally. Stabilization of fracture with reduced pain allows early movements of neighbouring joint knee and ankle; hence, reduces the chances of fracture diseases. With this we have been stimulated to take-up the study of managing the proximal tibia fracture by mini external fixator. Aim: The aim of this study was to manage proximal tibia fractures by mini external fixator and evaluate the results and efficacy of this method. Material and Method: A total of 30 patients having proximal tibial fractures admitted at our center between 2008 and 2010 were taken and the procedure carried out was closed manipulative reduction and stabilization with mini external fixator. All acute proximal tibia fractures including tibial plateau fractures above 17 years of age of either sex were included in the study. Fracture more than 3 weeks old were excluded from the study. Result: Out of 30 cases 13 were excellent, 14 cases good, and 3 showed fair. It was found that type 5 and 6 of Schatzker′s classification have lesser outcome type of fractures Conclusion: We have found that management of the proximal tibia fractures by mini external fixation method has a better outcome. Early mobilization of knee in the proximal tibia fractures after

  3. Effect of age on proximal esophageal response to swallowing

    Directory of Open Access Journals (Sweden)

    Roberto Oliveira Dantas

    2010-12-01

    Full Text Available CONTEXT: It has been demonstrated that the ageing process affects esophageal motility. OBJECTIVES: To evaluate the effect of the age on the proximal esophageal response to wet swallows. METHOD: We measured the proximal esophageal response to swallows of a 5 mL bolus of water in 69 healthy volunteers, 20 of them aged 18-30 years (group I, 27 aged 31-50 years (group II, and 22 aged 51-74 years (group III. We used the manometric method with continuous perfusion. The proximal esophageal contractions were recorded 5 cm from a pharyngeal recording site located 1 cm above the upper esophageal sphincter. The time between the onset of the pharyngeal and of the proximal esophageal recording (pharyngeal-esophageal time and the amplitude, duration and area under the curve of the proximal esophageal contraction were measured. RESULTS: The pharyngeal-esophageal time was shorter in group I subjects than in group II and III subjects (P<0.05. The duration of proximal esophageal contractions was longer in group I than in groups II and III (P<0.001. There was no differences between groups in the amplitude or area under the curve of contractions. There were no differences between groups II and III for any of the measurements. CONCLUSION: We conclude that the age may affects the response of the proximal esophagus to wet swallows.

  4. Dual pathology proximal median nerve compression of the forearm.

    LENUS (Irish Health Repository)

    Murphy, Siun M

    2013-12-01

    We report an unusual case of synchronous pathology in the forearm- the coexistence of a large lipoma of the median nerve together with an osteochondroma of the proximal ulna, giving rise to a dual proximal median nerve compression. Proximal median nerve compression neuropathies in the forearm are uncommon compared to the prevalence of distal compression neuropathies (eg Carpal Tunnel Syndrome). Both neural fibrolipomas (Refs. 1,2) and osteochondromas of the proximal ulna (Ref. 3) in isolation are rare but well documented. Unlike that of a distal compression, a proximal compression of the median nerve will often have a definite cause. Neural fibrolipoma, also called fibrolipomatous hamartoma are rare, slow-growing, benign tumours of peripheral nerves, most often occurring in the median nerve of younger patients. To our knowledge, this is the first report of such dual pathology in the same forearm, giving rise to a severe proximal compression of the median nerve. In this case, the nerve was being pushed anteriorly by the osteochondroma, and was being compressed from within by the intraneural lipoma. This unusual case highlights the advantage of preoperative imaging as part of the workup of proximal median nerve compression.

  5. Digital contrast subtraction radiography for proximal caries diagnosis

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Byung Cheol; Yoon, Suk Ja [Department of Dental Radiology, Chonnam National University Hospital, Gwangju (Korea, Republic of)

    2002-06-15

    To determine whether subtraction images utilizing contrast media can improve the diagnostic performance of proximal caries diagnosis compared to conventional periapical radiographic images. Thirty-six teeth with 57 proximal surfaces were radiographied using a size no.2 RVG-ui sensor (Trophy Radiology, Marne-la-Vallee, France). The teeth immersed in water-soluble contrast media and subtraction images were taken. Each tooth was then sectioned for histologic examination. The digital radiographic images and subtraction images were examined and interpreted by three dentists for proximal caries. The results of the proximal caries diagnosis were then verified with the results of the histologic examination. The proximal caries sensitivity using digital subtraction radiography was significantly higher than simply examining a single digital radiograph. The sensitivity of the proximal dentinal carious lesion when analyzed with the subtraction radiograph and the radiograph together was higher than with the subtraction radiograph or the radiograph alone. The use of subtraction radiography with contrast media may be useful for detecting proximal dentinal carious lesions.

  6. Reducing Postoperative Fracture Displacement After Locked Plating of Proximal Humerus Fractures: Current Concepts.

    Science.gov (United States)

    Newman, Jared; Kahn, Mani; Gruson, Konrad I

    2015-07-01

    The incidence of proximal humerus fractures in the elderly has been rising. Concomitantly, operative fixation with use of locking plates has been increasing. Postoperative complications of locking plate fixation, particularly in the setting of osteoporotic bone, include screw penetration of the articular surface, progressive fracture displacement, and avascular necrosis. Intraoperative techniques to enhance the fixation construct and reduce complications include use of rotator cuff sutures, bone void fillers (fibular strut allograft, cancellous allograft, autograft, bone cement), appropriate placement of divergent and shorter locking screws, and medial calcar reduction and support. More recent clinical and biomechanical studies suggest that use of these strategies may reduce complications after locked plating of osteoporotic proximal humerus fractures. Furthermore, a multidisciplinary approach to the evaluation and treatment of osteoporosis may be beneficial in these patients.

  7. Performance of a proximity cryogenic system for the ATLAS central solenoid magnet

    CERN Document Server

    Doi, Y; Makida, Y; Kondo, Y; Kawai, M; Aoki, K; Haruyama, T; Kondo, T; Mizumaki, S; Wachi, Y; Mine, S; Haug, F; Delruelle, N; Passardi, Giorgio; ten Kate, H H J

    2002-01-01

    The ATLAS central solenoid magnet has been designed and constructed as a collaborative work between KEK and CERN for the ATLAS experiment in the LHC project The solenoid provides an axial magnetic field of 2 Tesla at the center of the tracking volume of the ATLAS detector. The solenoid is installed in a common cryostat of a liquid-argon calorimeter in order to minimize the mass of the cryostat wall. The coil is cooled indirectly by using two-phase helium flow in a pair of serpentine cooling line. The cryogen is supplied by the ATLAS cryogenic plant, which also supplies helium to the Toroid magnet systems. The proximity cryogenic system for the solenoid has two major components: a control dewar and a valve unit In addition, a programmable logic controller, PLC, was prepared for the automatic operation and solenoid test in Japan. This paper describes the design of the proximity cryogenic system and results of the performance test. (7 refs).

  8. Parallel ProXimal Algorithm for Image Restoration Using Hybrid Regularization

    CERN Document Server

    Pustelnik, Nelly; Pesquet, Jean-Christophe

    2009-01-01

    Regularization approaches have demonstrated their effectiveness for solving ill-posed problems. However, in the context of variational restoration methods, a challenging question remains, which is how to find a good regularizer. While total variation introduces staircase effects, wavelet domain regularization brings other artefacts, e.g. ringing. However, a compromise can be found by introducing a hybrid regularization including several terms non necessarily acting in the same domain (e.g. spatial and wavelet transform domains). We adopt a convex optimization framework where the criterion to be minimized is split in the sum of more than two terms. For spatial domain regularization, isotropic or anisotropic total variation definitions using various gradient filters are considered. An accelerated version of the Parallel ProXimal Algorithm is proposed to perform the minimization. Some difficulties in the computation of the proximity operators involved in this algorithm are also addressed in this paper. Numerical...

  9. Minimizing Compositions of Functions Using Proximity Algorithms with Application in Image Deblurring

    Directory of Open Access Journals (Sweden)

    Feishe Chen

    2016-09-01

    Full Text Available We consider minimization of functions that are compositions of functions having closed-form proximity operators with linear transforms. A wide range of image processing problems including image deblurring can be formulated in this way. We develop proximity algorithms based on the fixed point characterization of the solution to the minimization problems . We further refine the proposed algorithms when the outer functions of the composed objective functions are separable. The convergence analysis of the developed algorithms is established. Numerical experiments in comparison with the well-known Chambolle-Pock algorithm and Zhang-Burger-Osher scheme for image deblurring are given to demonstrate that the proposed algorithms are efficient and robust.

  10. Open reduction and internal fixation of proximal humerus fractures.

    Science.gov (United States)

    Drosdowech, Darren S; Faber, Kenneth J; Athwal, George S

    2008-10-01

    Open reduction of proximal humeral fractures has the advantage of providing direct control over each fracture fragment and permitting anatomic reduction and fixation with advanced devices. Modern fixed-angle locking plates designed specifically for proximal humerus fractures have allowed the expansion of surgical indications permitting surgeons to address more complicated fractures. Advanced preoperative imaging and fluoroscopy allow a better understanding of fracture patterns and permit the surgeon to use this knowledge intraoperatively. Research is required to further validate fracture classification systems, to develop surgical guidelines for decision making, and to compare the outcomes of the various treatments options for proximal humerus fractures.

  11. Axillary artery injury as a complication of proximal humerus fractures.

    Science.gov (United States)

    McLaughlin, J A; Light, R; Lustrin, I

    1998-01-01

    Proximal humerus fractures are common injuries and represent approximately 5% of all fractures. These fractures are infrequently associated with neurovascular injuries. Brachial plexus injuries are uncommon, whereas axillary artery injuries are rare. A review of 19 previously reported cases of axillary artery injury after proximal humerus fracture revealed that 84% occurred in patients older than 50 years, 53% were associated with brachial plexus injury, and 21% resulted in upper extremity amputation. This study describes a case of axillary artery injury after proximal humerus fracture and, on the basis of a literature review, offers suggestions for the early diagnosis and effective treatment of this uncommon injury.

  12. Closed proximal muscle rupture of the biceps brachii in wakeboarders.

    Science.gov (United States)

    Pascual-Garrido, Cecilia; Swanson, Britta L; Bannar, Stephen M

    2012-06-01

    Closed proximal muscle rupture of the biceps brachii is a rare injury. In this report, two cases of closed proximal muscle rupture of the biceps brachii after wakeboard traumas are described. Both patients presented with a swollen arm, weakness during flexion, and a mass in the affected forearm. Magnetic resonance imaging showed displacement of the biceps brachii into the forearm. The rupture was successfully treated with muscle removal in one case and muscle repair in the other. In patients with a wakeboard trauma and similar presentations, closed proximal muscle rupture of the biceps brachii should be suspected.

  13. Avaliação radiográfica da osteotomia proximal de abertura gradual da tíbia Radiographic assessment of the opening wedge proximal tibial osteotomy

    Directory of Open Access Journals (Sweden)

    Carlos Francisco Bittencourt Silva

    2010-01-01

    Full Text Available OBJETIVO: Avaliar radiograficamente indivíduos submetidos à osteotomia de abertura gradual da tíbia proximal com o objetivo de analisar a inclinação tibial proximal no plano frontal e no plano sagital e a altura patelar. MÉTODO: Foram incluídos no estudo 22 indivíduos operados no Instituto Nacional de Traumatologia e Ortopedia (INTO para correção do desvio angular em varo da tíbia pela técnica de osteotomia de abertura gradual (OAG com fixador externo monolateral da Orthofix. Foram analisados pacientes submetidos à OAG com término de tratamento entre janeiro de 2000 e dezembro de 2006. A técnica utilizada para a mensuração dos valores foi obtida através de radiografias em AP com carga e perfil com flexão a 30º dos joelhos operados. RESULTADOS: Não houve diferenças entre os valores dos índices de altura patelar e inclinação tibial pré-operatórios e pós-operatórios de significância estatística nos pacientes avaliados. CONCLUSÃO: A osteotomia tibial de abertura gradual representa uma técnica que evita os problemas apresentados pela osteotomia tibial proximal alta, pois ela é realizada sem promover alterações do mecanismo extensor, desequilíbrio ligamentar ou distorções na tíbia proximal.OBJETIVO: To radiographically evaluate patients who underwent opening wedge proximal tibial osteotomy in order to analyze the proximal tibial slope in the frontal plane, sagittal plane, and patellar height. METHOD: The study included 22 patients operated on at the Instituto Nacional de Traumatologia e Ortopedia (INTO for the correction of varus angular tibial deviation using the opening wedge osteotomy (OWO technique with the Orthofix monolateral external fixator. We analyzed patients with OWO having completed treatment between January 2000 and December 2006. Values were measured by using X-rays of the anteroposterior profile with load and lateral profile with 30º flexion of the operated knees. RESULTS: No statistically

  14. 应用DCNLP法求解五连杆机器手臂对接问题%Five-linked Manipulator Arm Rendezvous Optimization Using DCNLP

    Institute of Scientific and Technical Information of China (English)

    梅成才; 潘修强; 陈军杰

    2012-01-01

    The application of direct collocation with nonlinear programming (DCNLP) method applied to a five-linked manipulator arm rendezvous with numerical analysis optimization problem is introduced. Firstly, this study takes advantage of Symbolic Language Programming and uses it to derive the Euler-Lagrange (E-L) equation symbolically. Since it is an optimal control problem," two-point boundary-valued problem(TPBVP)" is inevitable. Thus DCNLP is indroduced to seek the numerical solutions of the problem. Then, the optimal control problem/TPBVP is transformed into nonlinear programming problem using DCNLP method. The simulation result demonstrates that DCNLP method is neither acute nor discriminating to the initial guess of state variables; it also shows that DCNLP is robust in obtaining solutions for a large-scaled problem. At last, DCNLP requires large memory space and fast CPU. However these two concerns have not been an issue for now-a-days microcomputer. The major theme of this paper is to use DCNLP to facilitate the use of intelligent robotic manipulator and apply it to enhance the quality of medical care and senior citizen nursing. However, to take up a task such as this kind, the robot has to come up with some algorithm which intelligently gets the maneuvering done with elegance. Optimal control and optimization guarantee that the result found is the best by compairing to other methods. It may encounters difficulties in solving the system but the result is unbeatable.%为了使机器人在完成对接(Rendezvous)任务的同时让能耗达到最优,提出一种通过直接配置非线性规划法(DCNLP)来实现五连杆机器手臂能耗最优化的控制方法.使用Euler-Lagrange公式描述机器手臂的动力学方程,并借助符号运算推导相应公式;利用最优化控制的必要条件(Necessary Conditions)来规范最优指标,因是最优控制,求解过程必定遭遇“两端点边界值问题(Two-point Boundary-valued Problem)”,本文引

  15. The visual properties of proximal and remote distractors differentially influence reaching planning times: evidence from pro- and antipointing tasks.

    Science.gov (United States)

    Heath, Matthew; DeSimone, Jesse C

    2016-11-01

    The saccade literature has consistently reported that the presentation of a distractor remote to a target increases reaction time (i.e., the remote distractor effect: RDE). As well, some studies have shown that a proximal distractor facilitates saccade reaction time. The lateral inhibition hypothesis attributes the aforementioned findings to the inhibition/facilitation of target selection mechanisms operating in the intermediate layers of the superior colliculus (SC). Although the impact of remote and proximal distractors has been extensively examined in the saccade literature, a paucity of work has examined whether such findings generalize to reaching responses, and to our knowledge, no work has directly contrasted reaching RTs for remote and proximal distractors. To that end, the present investigation had participants complete reaches in target only trials (i.e., TO) and when distractors were presented at "remote" (i.e., the opposite visual field) and "proximal" (i.e., the same visual field) locations along the same horizontal meridian as the target. As well, participants reached to the target's veridical (i.e., propointing) and mirror-symmetrical (i.e., antipointing) location. The basis for contrasting pro- and antipointing was to determine whether the distractor's visual- or motor-related activity influence reaching RTs. Results demonstrated that remote and proximal distractors, respectively, increased and decreased reaching RTs and the effect was consistent for pro- and antipointing. Accordingly, results evince that the RDE and the facilitatory effects of a proximal distractor are effector independent and provide behavioral support for the contention that the SC serves as a general target selection mechanism. As well, the comparable distractor-related effects for pro- and antipointing trials indicate that the visual properties of remote and proximal distractors respectively inhibit and facilitate target selection.

  16. Comparison between two experimental protocols to promote osteoporosis in the maxilla and proximal tibia of female rats

    Directory of Open Access Journals (Sweden)

    Teófilo Juliana Mazzonetto

    2003-01-01

    Full Text Available The effects of two experimental protocols (ovariectomy associated or not with a low calcium diet used to promote osteoporosis in the rat maxilla and proximal tibia were compared 5 and 11 weeks after surgery. Female Wistar rats were ovariectomized or sham-operated. Half of the ovariectomized rats were fed a low Ca++ diet (ovx* and the remaining ovariectomized (ovx and sham animals received a standard chow. At sacrifice, the proximal metaphysis was excised from the tibia and the molars were extracted from the hemi-maxilla. Dry (60°C overnight and ash (700°C/14 h weights were measured and the ashes were used for Ca++ measurement by means of a colorimetric method. After 5 weeks, ovx caused no alteration while ovx* decreased proximal metaphysis (17% and maxilla (35% bone mass. After 11 weeks, ovx caused a 14% bone mass reduction in the proximal metaphysis but not in the maxilla, while ovx* caused a comparable bone mass reduction (30% in both bone segments. Calcium concentration was not altered in any experimental condition. The results show that estrogen deficiency is insufficient to cause maxillary osteoporosis in rats over an 11-week period and a long-term ovariectomy is needed to exert deleterious effect on proximal metaphysis bone mass. When a low Ca++ diet is associated with estrogen deficiency, however, a relatively precocious harmful effect is observed, twice as pronounced in the maxilla than in the proximal metaphysis. On a long-term basis, ovariectomy associated with a low Ca++ diet seems to be equally injurious to both proximal metaphysis and maxilla.

  17. Proximate composition and mineral profile of eight different ...

    African Journals Online (AJOL)

    USER

    2010-05-31

    May 31, 2010 ... Currently, several human health problems are related to diets. ... like climate, temperature etc. Proximate analysis .... intake of 0.88 g of protein per kg body weight for ... necessary for the production of hormones to regulate and.

  18. An unusual case of glipizide-induced proximal myopathy

    Directory of Open Access Journals (Sweden)

    Saibal Das

    2016-01-01

    Full Text Available This case report outlines a very rare case of glipizide-induced severe proximal myopathy in a 61-year-old diabetic man. After taking 10 mg glipizide for 5 months, diabetes was well controlled but the patient presented with progressive proximal muscle weakness in all the four limbs. Clinical examination and relevant investigations suggested it to be a case of proximal myopathy and might be drug induced. De-challenge was done and was treated resulting in reversal of the diseased state. After 3 more months, controlled re-challenge was done and there was recurrence of proximal muscle weakness. There were no evidences of any other possible metabolic, infective, organic or other pathologic causes giving rise to that condition and Naranjo adverse drug reaction probability scale suggested that it was "probable" that glipizide was responsible for the development of myopathy in this patient.

  19. Case report of LCP pediatric hip osteosynthesis of a proximal ...

    African Journals Online (AJOL)

    Case report of LCP pediatric hip osteosynthesis of a proximal femoral ... Pan African Medical Journal ... We present a case report demonstrating the experience of the department of pediatric orthopaedics of the University Orthopedic Hospital at ...

  20. Analysis on the characteristics of pulsed laser proximity fuze's echo

    Science.gov (United States)

    Wang, Kun; Chen, Huimin

    2011-06-01

    With the rapid development of semiconductor technology and laser technology, a kind of proximity fuze named pulsed laser proximity fuze has been applied. Compared with other fuzes, pulsed laser proximity fuze has high ranging precision and strong resistance to artificial active interference. It is an important development tendency of proximity fuze. The paper analyze the characteristic of target echo of laser signal, and then make theoretical analysis and calculation on the laser signal transmission in the smog. Firstly, use the pulse width of 10ns semiconductor laser fuze to do typical targets experiment, to get the echo information of target distance is 5m; then to do smog interference experiment, by comparing the pulse width amplitude and backscattering signal amplitude of laser fuze in simulation and experiment, analyzing the effect of anti-clutter, providing the evidence for the subsequent of circuit of signal amplification and processing.

  1. Proximate, Vitamins and Mineral Composition of Vitex doniana ...

    African Journals Online (AJOL)

    Keywords: Vitex doniana, micronutrients, proximate, vitamins and mineral composition, Fruit. ... incidence of malnutrition and increase in dietary ..... Properties of Formulated Syrup from Black ... Rod, R.S., Trend, S. and Phillip, T.D.A. (1996).

  2. Effects of Planting Locations on the Proximate Compositions of ...

    African Journals Online (AJOL)

    ADOWIE PERE

    Effects of Planting Locations on the Proximate Compositions of Moringa Oleifera leaves. *. 1. LAMIDI ... Moringa leaves contain more vitamin A than carrots, more calcium than ..... leaf source of food; that is, suitable for fortification of foods and ...

  3. Transverse Stress Fracture of the Proximal Patella: A Case Report

    National Research Council Canada - National Science Library

    Atsumi, Satoru; Arai, Yuji; Kato, Ko; Nishimura, Akinobu; Nakazora, Shigeto; Nakagawa, Shuji; Ikoma, Kazuya; Fujiwara, Hiroyoshi; Sudo, Akihiro; Kubo, Toshikazu

    2016-01-01

    .... Regarding patella stress fractures, so far only distal transverse or lateral longitudinal fractures have been reported, but there are no reports of transverse fractures occurring in the proximal patella...

  4. Nutritive Value Assessment of Four Crop Residues by Proximate ...

    African Journals Online (AJOL)

    Dr Grace Tona

    Ladoke Akintola University of Technology, P.M.B. 4000, Ogbomoso, Nigeria ... This study estimated the proximate composition and in vitro gas production parameters of rice husk, bean waste, citrus .... the minimum ammonia levels required by.

  5. Heavy metal, proximate and microbial profile of some selected ...

    African Journals Online (AJOL)

    Dr. Ogundiran

    2014-03-05

    Mar 5, 2014 ... The study on the elemental, proximate and microbial composition of fresh samples of Scomber .... package. .... hazardous for fish genetic material according to the study ... fishes for longer preservation time in agreement with.

  6. Computational proximity excursions in the topology of digital images

    CERN Document Server

    Peters, James F

    2016-01-01

    This book introduces computational proximity (CP) as an algorithmic approach to finding nonempty sets of points that are either close to each other or far apart. Typically in computational proximity, the book starts with some form of proximity space (topological space equipped with a proximity relation) that has an inherent geometry. In CP, two types of near sets are considered, namely, spatially near sets and descriptivelynear sets. It is shown that connectedness, boundedness, mesh nerves, convexity, shapes and shape theory are principal topics in the study of nearness and separation of physical aswell as abstract sets. CP has a hefty visual content. Applications of CP in computer vision, multimedia, brain activity, biology, social networks, and cosmology are included. The book has been derived from the lectures of the author in a graduate course on the topology of digital images taught over the past several years. Many of the students have provided important insights and valuable suggestions. The topics in ...

  7. A weighted fusion WiFi positioning algorithm based on distance rendezvous%一种WiFi距离交会加权融合定位算法

    Institute of Scientific and Technical Information of China (English)

    彭雪生; 花向红; 邱卫宁; 魏康; 刘少伟

    2017-01-01

    WiFi indoor location algorithm based on distance rendezvous is influenced by the environment . The lower precision of distance inversion results in bigger positioning error ,and the influences of different distance inversion models vary for positioning error characteristics .Because of over‐smoothing ,and bigger error ,this paper proposes a weighted fusion positioning algorithm based on GPR prediction model and loss model .The experiment results show :the fusion algorithm can effectively improve the positioning accuracy and obviously improve the centralisation of positioning results based on GPR model .%基于距离交会的WIFI室内定位算法受环境的影响,距离反演精度较低导致定位误差较大,不同距离反演模型对定位误差影响特性存在差异。考虑到GPR距离反演模型过度平滑引起定位结果扎堆的缺陷和传统损耗模型反演精度过低引起定位结果误差较大的缺陷,提出一种基于GPR预测模型和损耗模型的加权融合定位算法。实验结果表明:该融合算法能够有效提高定位精度并明显改善基于GPR模型定位算法的定位结果扎堆现象。

  8. New classification of proximal humeral fractures

    Energy Technology Data Exchange (ETDEWEB)

    Seemann, W.R.; Rupp, H.G.; Siebler, G.

    1986-08-01

    Neer's classification of humeral fractures was proved on 657 patients. This classification enables the radiologist to estimate the risk of avascular necrosis of the head of the humerus. The problematic group is that of four part lesions, which has a 19% incidence of humeral head necrosis. Since in this group minimal osteosynthesis produces better functional results than extensive osteosynthesis, a detailed pre-operative radiological description of the fracture type is necessary in order to spare the patient from extensive surgery which could have unsatisfactory results.

  9. Hemiarthroplasty for proximal humeral fracture: restoration of the Gothic arch.

    Science.gov (United States)

    Krishnan, Sumant G; Bennion, Phillip W; Reineck, John R; Burkhead, Wayne Z

    2008-10-01

    Proximal humerus fractures are the most common fractures of the shoulder girdle, and initial management of these injuries often determines final outcome. When arthroplasty is used to manage proximal humeral fractures, surgery remains technically demanding, and outcomes have been unpredictable. Recent advances in both technique and prosthetic implants have led to more successful and reproducible results. Key technical points include restoration of the Gothic arch, anatomic tuberosity reconstruction, and minimal soft tissue dissection.

  10. Inferring Human Situation using Proximity to Smart Objects

    OpenAIRE

    Baydan, Berker

    2013-01-01

    Human proximity tracking and human situation inference are exploited for comprehending human interaction with objects in kitchen. The importance of this study is to offer interactive and personalized kitchen environment for elderly and disabled people. Also, this smart environment allows for independent living for elderly and disabled people. This study proposes human proximity tracking and inferring human situation in smart environment. A precision of 100% and a recall of 65.22% were obtaine...

  11. Early Proximal Junctional Failure in Patients with Preoperative Sagittal Imbalance

    OpenAIRE

    2013-01-01

    Study Type Retrospective review. Introduction Sagittal imbalance has been associated with lower health-related quality of life outcomes, and restoration of imbalance is associated with improved outcomes.1 2 3 The long constructs used in adult spinal deformity have potential consequences such as proximal junctional kyphosis (PJK). Clinically, the development of PJK may not be as important as failure of the construct or vertebrae at the proximal end. As PJK does not lead to worse clinical outco...

  12. Rapid method to determine proximate analysis and pyritic sulfur

    Energy Technology Data Exchange (ETDEWEB)

    Rowe, M.W.; Hyman, M.

    1985-05-01

    The use of thermomagnetogravimetry has been proposed as an alternative to the ASTM methods for measuring the pyritic sulphur content of coal and for proximate analysis. This paper presents a comparison of the results of thermogravimetry for proximate analysis and thermomagnetometry for pyritic sulphur with ASTM values on the same samples. The thermomagnetogravimetric technique is quicker and easier than the ASTM methods, and of comparable accuracy.

  13. Use of thermogravimetry for proximate analysis of coals and cokes

    Energy Technology Data Exchange (ETDEWEB)

    Ottaway, M.

    1982-08-01

    An alternative method for the proximate analysis of coals and cokes using a thermobalance is described. The test measures water content, volatile matter, fixed carbon, and ash residue and takes <10 min to complete. The variety of coals and cokes tested in this investigation have given results which showed good correlation with values from the prescribed method. The thermogravimetric technique appears to be a feasible rapid alternative to standard methods for proximate analysis. (11 refs.)

  14. Post-traumatic osteonecrosis of the proximal humerus.

    Science.gov (United States)

    Patel, Shelain; Colaco, Henry B; Elvey, Michael E; Lee, Marcus H

    2015-10-01

    Post-traumatic osteonecrosis of the proximal humerus represents a challenging problem to the surgeon. It is commonly seen following multi-fragmentary fractures of the proximal humerus which may affect the long-term functional recovery after such injuries. This review summarises the current evidence on risk factors, reasons why estimating its epidemiology is difficult, the vascular supply of the humeral head, classification, and management options.

  15. Proximity functions for electrons up to 10 keV

    Energy Technology Data Exchange (ETDEWEB)

    Chmelevsky, D. (Institut fuer Medizinische Strahlenkunde der Universitaet Wuerzburg, Germany); Kellerer, A.M.; Terrissol, M.; Patau, J.P.

    1980-11-01

    Proximity functions for electrons up to 10 keV in water are computed from simulated particle tracks. Numerical results are given for the differential functions t(x) and the integral functions T(x). Basic characteristics of these functions and their connections to other microdosimetric quantities are considered. As an example of the applicability of the proximity functions, the quantity y/sub D/ for spheres is derived from t(x).

  16. HEMATOMA OF THE PROXIMAL NAIL FOLD. REPORT OF 41 CASES

    Directory of Open Access Journals (Sweden)

    Chang Patricia

    2011-04-01

    Full Text Available Background: The proximal fold is an important part of the nail apparatus it contributes to the formation of the nail plate and through the cuticle acts as an impermeable barrier protecting it from any cause.Objective: To know the proximal nail fold hematoma caused by the use of pulse oximeter.Material and Methods: A descriptive study was conducted in 41 patients with proximal nail hematoma secondary to the use of oximetry in patients hospitalized in the Intermediate and Intensive Care Unit at the Hospital General de Enfermedades from December 1, 2007 to December 31, 2010.Results: We studied 41 patients with proximal nail fold hematoma secondary to the use of oximeter, 30 (73.1% were males and 11 (26.8% females. The numbers of fingers affected by pulse oximeter were in one digit. 30 (73.1% cases, in two digits 6 (14.6%, in three digits 3 (7.3%, in 4 digits 1 (2.4% and in 5 digits 1 (2.4% case. The most affected proximal nail fold was right index: 24 (58.5%, right middle 11 (26.8%, right ring 6 (14.6%, left index 12 (29.2%, and left middle 6 (14.6% cases.Conclusions: Hematomas of the proximal nail fold may be caused by different traumatisms. The use of pulse oximeter is one of them.

  17. Psychological responses to the proximity of climate change

    Science.gov (United States)

    Brügger, Adrian; Dessai, Suraje; Devine-Wright, Patrick; Morton, Thomas A.; Pidgeon, Nicholas F.

    2015-12-01

    A frequent suggestion to increase individuals' willingness to take action on climate change and to support relevant policies is to highlight its proximal consequences, that is, those that are close in space and time. But previous studies that have tested this proximizing approach have not revealed the expected positive effects on individual action and support for addressing climate change. We present three lines of psychological reasoning that provide compelling arguments as to why highlighting proximal impacts of climate change might not be as effective a way to increase individual mitigation and adaptation efforts as is often assumed. Our contextualization of the proximizing approach within established psychological research suggests that, depending on the particular theoretical perspective one takes on this issue, and on specific individual characteristics suggested by these perspectives, proximizing can bring about the intended positive effects, can have no (visible) effect or can even backfire. Thus, the effects of proximizing are much more complex than is commonly assumed. Revealing this complexity contributes to a refined theoretical understanding of the role that psychological distance plays in the context of climate change and opens up further avenues for future research and for interventions.

  18. Accuracy of Digital Bitewing Radiography versus Different Views of Digital Panoramic Radiography for Detection of Proximal Caries

    Science.gov (United States)

    Abdinian, Mehrdad; Razavi, Sayed Mohammad; Samety, Amir Abbas; Faghihian, Elham

    2015-01-01

    Objectives: Dental caries are common and have a high incidence among populations. Radiographs are essential for detecting proximal caries. The best technique should be recognized for accurate detection of caries. The aim of this study was to compare the accuracy of detection of proximal caries using intraoral bitewing, extraoral bitewing, improved interproximal panoramic, improved orthogonality panoramic and conventional panoramic radiographs. Materials and Methods: In this descriptive cross sectional study, 100 extracted human teeth with and without proximal caries were used. Intra and extraoral radiographs were taken. Images were evaluated and scored by two observers. Scores were compared with the histological gold standard. The diagnostic accuracy of radiographs was assessed by means of receiver operating characteristic (ROC) curve analysis (P<0.05). Results: Microscopic evaluation of proximal surfaces revealed that 54.8% of the surfaces were sound and 45.2% were carious (with different depths). The differences in the area under the ROC curve (Az value) among the five techniques were not statistically significant. Conclusion: Improved interproximal panoramic and extraoral bitewing radiographs were superior to conventional panoramic radiography for detection of proximal caries ex vivo and should be considered for patients with contraindications for intraoral radiographs. PMID:26622284

  19. Noninvasive cross-sectional imaging of proximal caries using swept-source optical coherence tomography (SS-OCT) in vivo.

    Science.gov (United States)

    Shimada, Yasushi; Nakagawa, Hisaichi; Sadr, Alireza; Wada, Ikumi; Nakajima, Masatoshi; Nikaido, Toru; Otsuki, Masayuki; Tagami, Junji; Sumi, Yasunori

    2014-07-01

    The aim of this study was to determine the diagnostic accuracy of swept-source optical coherent tomography (SS-OCT) in detecting and estimating the depth of proximal caries in posterior teeth in vivo. SS-OCT images and bitewing radiographs were obtained from 86 proximal surfaces of 53 patients. Six examiners scored the locations according to a caries lesion depth scale (0-4) using SS-OCT and the radiographs. The results were compared with clinical observations obtained after the treatment. SS-OCT could detect the presence of proximal caries in tomograms that were synthesized based on the backscatter signal obtained from the proximal carious lesion through occlusal enamel. SS-OCT showed significantly higher sensitivity and larger area under the receiver operating characteristic curve than radiographs for the detection of cavitated enamel lesions and dentin caries (Student's t -test, p SS-OCT appears to be a more reliable and accurate method than bitewing radiographs for the detection and estimation of the depth of proximal lesions in the clinical environment.

  20. Philos钢板治疗肱骨近端骨折的临床应用%Treatment of humeral proximal fractures with proximal humeralinternal locking system,

    Institute of Scientific and Technical Information of China (English)

    杨小海; 吕建元; 张征石; 陈勇

    2011-01-01

    目的 探讨应用AO肱骨近端内固定锁定系统(Philos)治疗肱骨近端骨折的临床疗效.方法 我院2007年1月至2010年2月间使用Philos钢板治疗肱骨近端骨折25例,根据Neer分型:二部分骨折10例,三部分骨折12例,四部分骨折3例,其中3例骨折累及肱骨干上段.术后悬吊固定3周左右,术后3d开始适量肩关节被动运动,2周后适量主动活动,3周后加强主动功能锻炼.结果 全病例部获得随访,随访时间10~16个月,平均13.1个月,骨折均愈合,平均临床愈合时间12.6周(10~16周).按Constant评分标准评定,优11例,良8例,优良率为76%.结论 Philos钢板是治疗肱骨近端骨折特别是骨质疏松性骨折的理想选择.%Objective To discuss the clinical effect of open reduction and internal fixation with proximal humeral internal locking system(Philos)on proximal humeral fractures. Methods 25 cases with proximal humeral fractures treated with Philos from January 2007 to February 2010 were studied retrospectively. According to Neer classification, there were 10 cases with two-part fractures, 12 cases with three-part fractures and 3 cases with four-part fraetures including of 3 cases with fracture line extending to the humeral shaft. Passive shoulder exercise could be performed three days after operation. After two weeks, active shoulder exercise was done, which was gradually intensified three weeks after operation. Results The follow up period was 10-16 months (mean 13.1 months ) and all fractures were healed with average union period of 12.6 weeks (10~16 weeks). According to the constant shoulder score,11 cases were excellent, 8 cases were good, with all excellence rate of 76%. Conclusion philos plate is a good selection for proximal-humeral fractures and better for the fracture with osteoporosis.

  1. Retrograde versus Antegrade Approach for the Management of Large Proximal Ureteral Stones

    Science.gov (United States)

    Mykoniatis, Ioannis; Isid, Ayman; Gofrit, Ofer N.; Rosenberg, Shilo; Hidas, Guy; Landau, Ezekiel H.; Pode, Dov; Duvdevani, Mordechai

    2016-01-01

    Objective. To evaluate and compare the efficacy and safety of retrograde versus antegrade ureteroscopic lithotripsy for the treatment of large proximal ureteral stones. Patients and Methods. We retrospectively analyzed the medical records of patients with proximal ureteral stones >15 mm, treated in our institution from January 2011 to January 2016. Intraoperative parameters, postoperative outcomes, and complications were recorded and compared between the two techniques. Results. Our analysis included 57 patients. Thirty-four patients (59.6%) underwent retrograde and 23 patients (40.4%) underwent antegrade ureteroscopy. There was no significant difference in patients' demographics and stone characteristics between the groups. Stone-free rate was significantly higher (p = 0.033) in the antegrade group (100%) compared to retrograde one (82.4%). Fluoroscopy time, procedure duration, and length of hospitalization were significantly (p < 0.001) lower in retrograde approach. On the other hand, the need for postoperative stenting was significantly lower in the antegrade group (p < 0.001). No difference was found between the groups (p = 0.745) regarding postoperative complications. Conclusions. Antegrade ureteroscopy is an efficient and safe option for the management of large proximal ureteral stones. It may achieve high stone-free rates compared to retrograde ureteroscopy with the drawback of longer operative time, fluoroscopy time, and length of hospitalization. PMID:27766263

  2. Proximal Remote Sensing Buggies and Potential Applications for Field-Based Phenotyping

    Directory of Open Access Journals (Sweden)

    David Deery

    2014-07-01

    Full Text Available The achievements made in genomic technology in recent decades are yet to be matched by fast and accurate crop phenotyping methods. Such crop phenotyping methods are required for crop improvement efforts to meet expected demand for food and fibre in the future. This review evaluates the role of proximal remote sensing buggies for field-based phenotyping with a particular focus on the application of currently available sensor technology for large-scale field phenotyping. To illustrate the potential for the development of high throughput phenotyping techniques, a case study is presented with sample data sets obtained from a ground-based proximal remote sensing buggy mounted with the following sensors: LiDAR, RGB camera, thermal infra-red camera and imaging spectroradiometer. The development of such techniques for routine deployment in commercial-scale breeding and pre-breeding operations will require a multidisciplinary approach to leverage the recent technological advances realised in computer science, image analysis, proximal remote sensing and robotics.

  3. Load transfer in the proximal tibia following implantation with a unicompartmental knee replacement: a static snapshot.

    Science.gov (United States)

    Simpson, D J; Kendrick, B J L; Dodd, C A F; Price, A J; Gill, H S; Murray, D W

    2011-05-01

    Unicompartmental knee replacement (UKR) is an appealing alternative to total knee replacement when the patient has isolated medial compartment osteoarthritis. A common observation post-operatively is radiolucency between the tibial tray wall and the bone. In addition, some patients complain of persistent pain over the proximal tibia antero-medially; this may be related to elevated bone strains in the tibia. Currently, there is no intentionally made mechanical bond between the vertical wall of an Oxford UKR and the adjacent bone; whether one exists or not will influence the load transmission in the proximal tibia and may affect the elevated tibia strain. The aim of this study was to investigate how introducing a mechanical tie between the tibial tray wall and the adjacent bone might alter the load carried into the tibia for both cemented and cementless UKRs. Strain energy density in the region of bone adjacent to the tray wall was considerably increased when a mechanical tie was introduced; this has the potential of reducing the likelihood of a radiolucency occurring in that region. Moreover, a mechanical tie had the effect of reducing proximal tibia strain, which may decrease the incidence of pain following implantation with a UKR.

  4. Development of a new proximate analysis based correlation to predict calorific value of coal

    Energy Technology Data Exchange (ETDEWEB)

    A.K. Majumder; Rachana Jain; P. Banerjee; J.P. Barnwal [Advanced Materials and Processes Research Institute (CSIR), Bhopal (India). Department of Mineral Engineering

    2008-10-15

    The experimental determination of higher heating value (HHV) of solid fuels is a cost intensive process, as it requires special instrumentation and highly trained analyst to operate it, where as proximate analysis data can be obtained relatively easily using an ordinary muffle furnace. Therefore, to simplify the task and to reduce the cost of analysis many correlations were developed for determining HHV from proximate analysis of solid fuels. An attempt has been made in this paper to evaluate the applicability of these correlations with a special focus on Indian coals. It has been observed that the developed correlations are either complex in nature or by-pass the effect of important variables like moisture and ash contents of coals. An effort has, therefore, been made to develop a simple correlation based on proximate analysis data for predicting HHV of coal (as-received basis). The model presented here is developed using analyses of 250 coal samples and its significance lies in involvement of all the major variables affecting the HHV. The developed model appears to be better than the existing models. 10 refs., 4 figs., 2 tabs.

  5. Early asymptomatic intrathoracic migration of a threaded pin after proximal humeral osteosynthesis.

    Science.gov (United States)

    Cerruti, Paola; Mangano, Tony; Giovale, Marcello; Repetto, Ilaria

    2016-01-01

    Pinning with metallic wires is a suitable therapeutic option for proximal humeral fractures. Loosening and migration of such devices from this site is uncommon. Despite infrequently occurring, however, the literature reports dramatic and potentially lethal complications related to wires dislocation. A 69-year-old woman underwent closed reduction and fixation of a proximal 3-part humeral fracture by mean of two retrograde Kirschner wires and one anterograde threaded pin. One month after surgery, during a routine follow-up control, it was diagnosed the migration of the threaded pin in the left lung parenchyma. In the meantime, the only symptom the patient complained was an episodic intercostal pain of mild intensity, with referred onset 1 week after surgery. The migrated pin was removed through thoracoscopic approach in the emergency setting, without intra- or post-operative complications. Only a few authors reported similar complications after fixation of proximal humeral fractures. Immediate surgical removal of the device is always mandatory. When considering pinning fixation for shoulder girdle's fractures, orthopedic surgeons should take into account the risk for wire dislocation, and take up adequate precautions during surgery and follow-up control visits.

  6. Induced magnetism in exfoliated graphene via proximity effect with yttrium iron garnet thin films

    Science.gov (United States)

    Amado, Mario; Li, Yang; di Bernardo, Angelo; Lombardo, Antonio; Ferrari, Andrea C.; Robinson, Jason

    The recent discovery of the quantum anomalous Hall effect (QAHE) in magnetically doped topological insulators cooled below in the milikelvin regime represents breakthrough in the field of spintronics. Theoretically, the QAHE should occur in graphene proximity coupled to a ferromagnetic insulato but with the promise of much higher operating temperatures for practical applications. Hints of proximity-induced magnetism in graphene coupled to yttrium iron garnet (YIG) films have been reported although the QAHE remains unobserved; the lack of a fully developed plateau in graphene/YIG devices can be attributed to poor interfacial coupling and therefore a dramatically reduced magnetic proximity effect. Here we report the deposition and characterisation of epitaxial thin-films of YIG on lattice-matched gadolinium gallium garnet substrates by pulsed laser deposition. Pristine exfoliated graphene flakes transferred mechanically onto the YIG are reported alongside results that correlate the effects of YIG morphology on the electronic and crystal properties of graphene by electrical (low temperature magnetoresistance measurements in Hall-bar-like configuration) and optical (Raman) means.

  7. A PROSPECTIVE STUDY ON TREATMENT OF PROXIMAL HUMERUS FRACTURES IN ADULTS

    Directory of Open Access Journals (Sweden)

    Bhavani Prasad

    2015-10-01

    displacement (usually rotation of each fragment and hold it in place with an implant. Thus the greater tuberosity fragment which has usually been displaced proximally and rotated upward by rotator cuff muscles inserted into it, is replac ed and fixed to the major humeral head fragment, lesser tuberosity fragment similarly displaced by subscapularis is replaced and fixed. Three & four part fractures represent 13 to 16% of proximal humeral fractures. Treatment options for these displaced fra ctures include open reduction and fixation. Neer recommended open reduction and internal fixation for displaced two and three parts fractures . Most of the poor results following open reduction and internal fixation of 3 three part fracture are due to imper fect technique. In a three or four part fracture dislocation when the head of the humerus is entirely devoid of any blood supply it can be replaced by a humeral prosthesis. This dissertation tries to bring out the salient features of all operable fractures of proximal humerus which require open reduction and fixation especially in adult patients in whom the duration of stay in hospital reflect on the earning capacity of the person and in elderly patients in whom immobilization of upper limb is associated wi th reflex sympathetic dystrophy, stiffness and shoulder hand syndrome. Thus the requirement of early mobilization without any undue risk of loss of fixation and reduction.

  8. Can arthroscopic rotator cuff repair prevent proximal migration of the humeral head?

    Directory of Open Access Journals (Sweden)

    Pablo Sanz-Ruiz

    2015-12-01

    Full Text Available Introduction: Shoulder arthroscopy has become increasingly used in recent years, especially in rotator cuff repair. The purpose of this study was to determine whether arthroscopic rotator cuff repair could prevent proximal migration of the humeral head. Material and Methods: We performed a retrospective study of 56 patients suffering from shoulder pain. They were divided into two groups, one comprising patients with impingement syndrome who underwent acromioplasty only and another comprising patients with rotator cuff tear who underwent acromioplasty combined with rotator cuff repair. The pre-operative Hirooka angle and the results of the simple shoulder test (SST were compared after 1 year. Results: We found no differences between the groups for the Hirooka angle or SST results. We did find a significant difference (P<0.05 between pre-operative and post-operative SST results. Conclusions: Rotator cuff repair using arthroscopy is a minimally invasive procedure that improves function and prevents proximal migration of the humeral head after 1 year of follow-up. [Arch Clin Exp Surg 2015; 4(4.000: 190-195

  9. Induced spectral gap and pairing correlations from superconducting proximity effect

    Science.gov (United States)

    Chiu, Ching-Kai; Cole, William S.; Das Sarma, S.

    2016-09-01

    We theoretically consider superconducting proximity effect, using the Bogoliubov-de Gennes (BdG) theory, in heterostructure sandwich-type geometries involving a normal s -wave superconductor and a nonsuperconducting material with the proximity effect being driven by Cooper pairs tunneling from the superconducting slab to the nonsuperconducting slab. Applications of the superconducting proximity effect may rely on an induced spectral gap or induced pairing correlations without any spectral gap. We clarify that in a nonsuperconducting material the induced spectral gap and pairing correlations are independent physical quantities arising from the proximity effect. This is a crucial issue in proposals to create topological superconductivity through the proximity effect. Heterostructures of three-dimensional topological insulator (TI) slabs on conventional s -wave superconductor (SC) substrates provide a platform, with proximity-induced topological superconductivity expected to be observed on the "naked" top surface of a thin TI slab. We theoretically study the induced superconducting gap on this naked surface. In addition, we compare against the induced spectral gap in heterostructures of SC with a normal metal or a semiconductor with strong spin-orbit coupling and a Zeeman splitting potential (another promising platform for topological superconductivity). We find that for any model for the non-SC metal (including metallic TI) the induced spectral gap on the naked surface decays as L-3 as the thickness (L ) of the non-SC slab is increased in contrast to the slower 1 /L decay of the pairing correlations. Our distinction between proximity-induced spectral gap (with its faster spatial decay) and pairing correlation (with its slower spatial decay) has important implications for the currently active search for topological superconductivity and Majorana fermions in various superconducting heterostructures.

  10. 自主空中加油会合过程中飞行制导律设计%Flight guidance law design in process of rendezvous for autonomous aerial refueling

    Institute of Scientific and Technical Information of China (English)

    宋海军; 袁锁中; 刘晓宇

    2014-01-01

    Aiming at the problem of rendezvous for autonomous aerial refueling which is a major issue to be solved current-ly,a method of proportional navigation with terminal angular constraint is used to guide the receiver to flight into refueling dis-trict. The nonlinear guidance algorithm is adopted for the tanker to guide the tanker to flight on the racetrack. A solution to over-cove the nonlinear guidance algorithm failure caused by wind is presented. The concepts of virtual target and virtual tanker is in-troduced to maintain the time synchronize of the receiver and the tanker in rendezvous. A corresponding velocity controller was designed. The simulation platform was built with Matlab/Simulink to verify the rendezvous guidance law for autonomous aerial re-fueling. The simulation results show that the guidance law can satisfy the requirement of rendezvous for autonomous aerial re-fueling.%针对目前自主空中加油亟需解决的会合问题,采用带有末端角约束的比例导引方法,实现了受油机导引进入加油区域,加油机采用非线性制导算法跟踪赛马场跑道线飞行,并给出了有风条件下非线性制导算法可能失效的解决办法。引入虚拟目标和虚拟加油机的概念,保持受油机和加油机在会合上的时间同步,设计了相应的速度控制器。利用Mat-lab/Simulink搭建仿真平台对空中加油会合制导律进行了仿真验证,仿真结果表明设计的制导律能满足自主空中加油的会合要求。

  11. Analysis and design of phasing strategy for near-earth short rendezvous mission%近地快速交会调相策略设计与任务分析

    Institute of Scientific and Technical Information of China (English)

    杨震; 罗亚中; 张进

    2015-01-01

    基于我国2天交会对接方案,通过合理减少定轨、变轨参数计算与指令上传及不可测控区域占用的飞行圈次,建立了5圈快速交会对接的调相变轨方案,采用四脉冲修正特殊点变轨算法进行求解。给出了满足调相段终端控制精度所需要的定轨精度,分析了追踪航天器入轨精度、追踪航天器入轨远地点高度、目标轨道高度、调相段终端瞄准点等参数对最优初始相位角范围的影响规律。简要分析了为获得需要的初始相位角,目标航天器的调相策略及追踪航天器可能的发射机会。%Based on the two-day profile of Chinese rendezvous and docking mission,a 5 -revolution short-rendezvous phasing strategy was proposed by cutting down the flight duration for orbit determination,computation of maneuver parameters and command uploading,and non-visible course of flight.This phasing strategy was solved by using the algorithm of four-impulse modified special-point maneuver.The required precision of orbit determination to meet the control precision at the end of phasing was obtained.Then,the optimal phase range and total velocity increment were analyzed.Further results show that the optimal phase range is affected by the target spacecraft’s orbit injection accuracy,the chaser’s orbit insert precision and apogee height,the target orbital altitude and the final desired target point of rendezvous phasing.Finally,in order to obtain the starting phase angle,both the target spacecraft’s phasing strategy and the chaser’s launch chances are analyzed for the short rendezvous mission.

  12. Treatment of proximal humeral fractures using anatomical locking plate: correlation of functional and radiographic results

    Directory of Open Access Journals (Sweden)

    Antonio Carlos Tenor Junior

    2016-06-01

    Full Text Available ABSTRACT OBJECTIVE: To correlate the functional outcomes and radiographic indices of proximal humerus fractures treated using an anatomical locking plate for the proximal humerus. METHODS: Thirty-nine patients with fractures of the proximal humerus who had been treated using an anatomical locking plate were assessed after a mean follow-up of 27 months. These patients were assessed using the University of California Los Angeles (UCLA score and their range of motion was evaluated using the method of the American Academy of Orthopedic Surgeons on the operated shoulder and comparative radiographs on both shoulders. The correlation between radiographic measurements and functional outcomes was established. RESULTS: We found that 64% of the results were good or excellent, according to the UCLA score, with the following means: elevation of 124°; lateral rotation of 44°; and medial rotation of thumb to T9. The type of fracture according to Neer's classification and the patient's age had significant correlations with the range of motion, such that the greater the number of parts in the fracture and the greater the patient's age were, the worse the results also were. Elevation and UCLA score were found to present associations with the anatomical neck-shaft angle in anteroposterior view; fractures fixed with varus deviations greater than 15° showed the worst results (p < 0.001. CONCLUSION: The variation in the neck-shaft angle measurements in anteroposterior view showed a significant correlation with the range of motion; varus deviations greater than 15° were not well tolerated. This parameter may be one of the predictors of functional results from proximal humerus fractures treated using a locking plate.

  13. Outcome analysis following removal of locking plate fixation of the proximal humerus

    Directory of Open Access Journals (Sweden)

    Fischer Florian

    2008-10-01

    Full Text Available Abstract Background Concerning surgical management experience with locking plates for proximal humeral fractures has been described with promising results. Though, distinct hardware related complaints after fracture union are reported. Information concerning the outcome after removal of hardware from the proximal humerus is lacking and most studies on hardware removal are focused on the lower extremity. Therefore the aim of this study was to analyze the functional short-term outcome following removal of locking plate fixation of the proximal humerus. Methods Patients undergoing removal of a locking plate of the proximal humerus were prospectively followed. Patients were subdivided into the following groups: Group HI: symptoms of hardware related subacromial impingement, Group RD: persisting rotation deficit, Group RQ: patients with request for a hardware removal. The clinical (Constant-Murley score and radiologic (AP and axial view follow-up took place three and six months after the operation. To evaluate subjective results, the Medical Outcomes Study Short Form-36 (SF-36, was completed. Results 59 patients were included. The mean length of time with the hardware in place was 15.2 ± 3.81 months. The mean of the adjusted overall Constant score before hardware removal was 66.2 ± 25.2% and increased significantly to 73.1 ± 22.5% after 3 months; and to 84.3 ± 20.6% after 6 months (p Conclusion A significant improvement of clinical outcome following removal was found. However, a general recommendation for hardware removal is not justified, as the risk of an anew surgical and anesthetic procedure with all possible complications has to be carefully taken into account. However, for patients with distinct symptoms it might be justified.

  14. The Floating Upper Limb: Multiple Injuries Involving Ipsilateral, Proximal, Humeral, Supracondylar, and Distal Radial Limb

    Science.gov (United States)

    Manaan, Qazi; Bashir, Adil; Zahoor, Adnan; Mokhdomi, Taseem A.

    2016-01-01

    Floating arm injury represents a common yet complicated injury of the childhood severely associated with limb deformation and even morbidity, if not precisely addressed and credibly operated. Here, we report a rare floating upper limb case of a 9-year-old boy with multiple injuries of ipsilateral proximal humeral, supracondylar and distal radial limb. This is the first report to document such a combined floating elbow and floating arm injury in the same limb. In this report, we discuss the surgical procedures used and recovery of the patient monitored to ascertain the effectiveness of the method in limb reorganisation. PMID:27583121

  15. Magnetic proximity effect as a pathway to spintronic applications of topological insulators.

    Science.gov (United States)

    Vobornik, Ivana; Manju, Unnikrishnan; Fujii, Jun; Borgatti, Francesco; Torelli, Piero; Krizmancic, Damjan; Hor, Yew San; Cava, Robert J; Panaccione, Giancarlo

    2011-10-12

    Spin-based electronics in topological insulators (TIs) is favored by the long spin coherence(1,2) and consequently fault-tolerant information storage. Magnetically doped TIs are ferromagnetic up to 13 K,(3) well below any practical operating condition. Here we demonstrate that the long-range ferromagnetism at ambient temperature can be induced in Bi(2-x)Mn(x)Te(3) by the magnetic proximity effect through deposited Fe overlayer. This result opens a new path to interface-controlled ferromagnetism in TI-based spintronic devices.

  16. An evaluation of chemical arthrodesis of the proximal interphalangeal joint in the horse by using monoiodoacetate.

    OpenAIRE

    Penraat, J H; Allen, A L; Fretz, P. B.; Bailey, J. V.

    2000-01-01

    The use of monoiodoacetate (MIA) for arthrodesis of the proximal interphalangeal joint (PIJ) and the effect of exercise on the degree of fusion were investigated. Eight horses received 3 injections (Weeks 0, 3, 6) of MIA (2 mL; 60 mg/mL) into the right or left front PIJ. Peri-operatively, the horses received phenylbutazone, butorphanol, and abaxial sesamoidean nerve blocks to relieve pain. During the study, the horses were monitored for general health, lameness, and swelling around the inject...

  17. Prediction of product distribution in fine biomass pyrolysis in fluidized beds based on proximate analysis.

    Science.gov (United States)

    Kim, Sung Won

    2015-01-01

    A predictive model was satisfactorily developed to describe the general trends of product distribution in fluidized beds of lignocellulosic biomass pyrolysis. The model was made of mass balance based on proximate analysis and an empirical relationship with operating parameters including fluidization hydrodynamics. The empirical relationships between product yields and fluidization conditions in fluidized bed pyrolyzers were derived from the data of this study and literature. The gas and char yields showed strong functions of temperature and vapor residence time in the pyrolyzer. The yields showed a good correlation with fluidization variables related with hydrodynamics and bed mixing. The predicted product yields based on the model well accorded well with the experimental data.

  18. A proximal point method for nonsmooth convex optimization problems in Banach spaces

    Directory of Open Access Journals (Sweden)

    Y. I. Alber

    1997-01-01

    Full Text Available In this paper we show the weak convergence and stability of the proximal point method when applied to the constrained convex optimization problem in uniformly convex and uniformly smooth Banach spaces. In addition, we establish a nonasymptotic estimate of convergence rate of the sequence of functional values for the unconstrained case. This estimate depends on a geometric characteristic of the dual Banach space, namely its modulus of convexity. We apply a new technique which includes Banach space geometry, estimates of duality mappings, nonstandard Lyapunov functionals and generalized projection operators in Banach spaces.

  19. The Floating Upper Limb: Multiple Injuries Involving Ipsilateral, Proximal, Humeral, Supracondylar, and Distal Radial Limb.

    Science.gov (United States)

    Manaan, Qazi; Bashir, Adil; Zahoor, Adnan; Mokhdomi, Taseem A; Danish, Qazi

    2016-09-01

    Floating arm injury represents a common yet complicated injury of the childhood severely associated with limb deformation and even morbidity, if not precisely addressed and credibly operated. Here, we report a rare floating upper limb case of a 9-year-old boy with multiple injuries of ipsilateral proximal humeral, supracondylar and distal radial limb. This is the first report to document such a combined floating elbow and floating arm injury in the same limb. In this report, we discuss the surgical procedures used and recovery of the patient monitored to ascertain the effectiveness of the method in limb reorganisation.

  20. [Condition of cavernous tissue of the penis after unilateral incomplete proximal intracavernous falloprosthesis].

    Science.gov (United States)

    Taurashvili, G I; Medvedev, V L; Chilov, S A; Kochov, V N; Taruashvili, I G

    2011-01-01

    Unilateral incomplete proximal intracavernous falloprosthesis (UIPIF) was followed by US-dopplerography of the intact penis and penis in medical erection induced by E1 prostoglandin introduction into the intact cavernous body. UIPIF preserves 89-90% of functionally active cavernous tissue with effective blood flow. Investigation 2 months and more after operation demonstrated that systolic blood flow rate in the cavernous artery of the cavernous tissue around the endoprosthersis can reach values registered in normal erection. The conclusion is made that after UIPIF quality of sexual life of the patient improves due to creation of additional density and axial stability of the trunk of the penis.

  1. Techniques for detecting proximity to voltage collapse in AC/DC systems

    Energy Technology Data Exchange (ETDEWEB)

    Canizares, Claudio A. [Escuela Politecnica Nacional, Quito (Ecuador); Long, Willis F.; Alvarado, Fernando L.; DeMarco, CChristopher L. [Wisconsin Univ., Madison, WI (United States)

    1992-12-31

    This paper describes three different techniques to detect proximity to voltage collapse (saddle-node bifurcation) in AC/DC systems; namely, direct (point of collapse) methods, continuation methods, and transient energy function methods. These techniques are compared among them, and also against the voltage sensitivity factor method using a 173 bus ac/dc test system. Various operational conditions are considered for this test system, so that transfer capabilities between areas and the effects of HVDC links can be analysed from the point of view of voltage collapse. 24 refs., 7 figs.

  2. ATLAS IBL operational experience

    CERN Document Server

    Takubo, Yosuke; The ATLAS collaboration

    2016-01-01

    The Insertable B-Layer (IBL) is the inner most pixel layer in the ATLAS experiment, which was installed at 3.3 cm radius from the beam axis in 2014 to improve the tracking performance. To cope with the high radiation and hit occupancy due to proximity to the interaction point, a new read-out chip and two different silicon sensor technologies (planar and 3D) have been developed for the IBL. After the long shut-down period over 2013 and 2014, the ATLAS experiment started data-taking in May 2015 for Run-2 of the Large Hadron Collider (LHC). The IBL has been operated successfully since the beginning of Run-2 and shows excellent performance with the low dead module fraction, high data-taking efficiency and improved tracking capability. The experience and challenges in the operation of the IBL is described as well as its performance.

  3. Human Spaceflight Trajectory Operations: A Case Study from STS-132/ULF4

    Science.gov (United States)

    Cutri-Kohart, Rebecca; Browns, Ansley

    2010-01-01

    Prior to the launch of the STS-132/ULF4 mission, the International Space Station (ISS) Flight Control Team was alerted to the approach of a space debris with a predicted time of closest approach approximately 1 hr after Space Shuttle docking. As a result, the ISS team considered performing a collision avoidance maneuver prior to the Space Shuttle s approach. The purpose of this presentation will be to use this case study to illustrate best practices of the human spaceflight trajectory operations team. The presentation will begin with an overview of the roles of the real-time ISS and Space Shuttle trajectory flight control teams. Then, the STS-132/ULF4 case study will be used to illustrate the issues and lessons learned involved in performing Space Shuttle rendezvous maneuver planning and execution. Specific elements of the STS-132 Space Shuttle rendezvous maneuver profile that can be used to provide mission assurance in cases of trajectory uncertainty will be described and discussed. Additionally, this case study will be used to provide context for identifying lessons learned in an operational environment that requires technical and decision-making coordination between two control center teams with two potentially maneuvering space vehicles.

  4. Calculus Rules for V-Proximal Subdifferentials in Smooth Banach Spaces

    Directory of Open Access Journals (Sweden)

    Messaoud Bounkhel

    2016-01-01

    Full Text Available In 2010, Bounkhel et al. introduced new proximal concepts (analytic proximal subdifferential, geometric proximal subdifferential, and proximal normal cone in reflexive smooth Banach spaces. They proved, in p-uniformly convex and q-uniformly smooth Banach spaces, the density theorem for the new concepts of proximal subdifferential and various important properties for both proximal subdifferential concepts and the proximal normal cone concept. In this paper, we establish calculus rules (fuzzy sum rule and chain rule for both proximal subdifferentials and we prove the Bishop-Phelps theorem for the proximal normal cone. The limiting concept for both proximal subdifferentials and for the proximal normal cone is defined and studied. We prove that both limiting constructions coincide with the Mordukhovich constructions under some assumptions on the space. Applications to nonconvex minimisation problems and nonconvex variational inequalities are established.

  5. Topology of digital images visual pattern discovery in proximity spaces

    CERN Document Server

    Peters, James F

    2014-01-01

    This book carries forward recent work on visual patterns and structures in digital images and introduces a near set-based a topology of digital images. Visual patterns arise naturally in digital images viewed as sets of non-abstract points endowed with some form of proximity (nearness) relation. Proximity relations make it possible to construct uniform topolo- gies on the sets of points that constitute a digital image. In keeping with an interest in gaining an understanding of digital images themselves as a rich source of patterns, this book introduces the basics of digital images from a computer vision perspective. In parallel with a computer vision perspective on digital images, this book also introduces the basics of prox- imity spaces. Not only the traditional view of spatial proximity relations but also the more recent descriptive proximity relations are considered. The beauty of the descriptive proximity approach is that it is possible to discover visual set patterns among sets that are non-overlapping ...

  6. Intramedullary nailing of the proximal humerus: evolution, technique, and results.

    Science.gov (United States)

    Dilisio, Matthew F; Nowinski, Robert J; Hatzidakis, Armodios M; Fehringer, Edward V

    2016-05-01

    Proximal humerus fractures are the third most common fracture in the elderly. Although most fractures can be treated conservatively with acceptable outcomes, certain fracture patterns are at high risk for progression to humeral malunions, nonunions, stiffness, and post-traumatic arthrosis. The goal of antegrade humeral nailing of proximal humerus fractures is to provide stability to a reduced fracture that allows early motion to optimize patient outcomes. Certain technical pearls are pivotal in managing these difficult fractures with nails; these include rotator cuff management, respect of the soft tissues, anatomic tuberosity position, blood supply maintenance, knowledge of the deforming forces on the proximal humerus, fracture reduction, and rehabilitation strategies. Modern proximal humeral nail designs and techniques assist the surgeon in adhering to these principles and have demonstrated promising outcomes. Humeral nail designs have undergone significant innovation during the past 40 years and now can provide stable fixation in the humeral shaft distally as well as improved stability in the head and tuberosity fragments, which were the common site of fixation failure with earlier generation implants. Compared with other fixation strategies, such as locking plate fixation, no compelling evidence exists to suggest one technique over another. The purpose of this review is to describe the history, results, new designs, and techniques that make modern intramedullary nailing of proximal humerus fractures a viable treatment option.

  7. Value of proximal regurgitant jet size in tricuspid regurgitation.

    Science.gov (United States)

    Rivera, J M; Vandervoort, P; Mele, D; Weyman, A; Thomas, J D

    1996-04-01

    Recent studies have shown good agreement between proximal regurgitant jet size obtained with transthoracic color flow mapping and regurgitant fraction in patients with mitral regurgitation. To evaluate this in patients with tricuspid regurgitation, we analyzed 40 patients in sinus rhythm, 16 with free jets and 24 with impinging jets, comparing proximal jet size (millimeters) with parameters derived from the Doppler two-dimensional echocardiographic method (regurgitant fraction) and the flow-convergence method (peak flow rate, effective regurgitant orifice area, and momentum). Good agreement was noted between peak flow rate (r = 0.80, p fair between effective regurgitant orifice (r = 0.65, p < 0.001), peak flow rate (0.65, p < 0.001), and momentum (r = 0.62, p < 0.001) with mean jet proximal size. Jet proximal size obtained with transthoracic color flow mapping is a good semiquantitative tool for measuring tricuspid regurgitation in free jets that correlates well with established measures of the severity and with new parameters available from analysis of the proximal acceleration field. In patients with eccentrically directed wall jets, the correlation weakens but still appears clinically significant.

  8. FUNCTIONAL OUTCOME OF PHILOS PLATE FIXATION FOR PROXIMAL HUMERUS FRACTURES

    Directory of Open Access Journals (Sweden)

    Ch. Venkateswarlu

    2016-01-01

    Full Text Available INTRODUCTION Treating a proximal humerus fracture remained a challenging problem until proximal humeral internal locking system has been developed. Our study aims at evaluating the functional outcome of 30 consecutive patients with proximal humeral fracture treated by Philos plate fixation; 30 patients with proximal humeral fractures who attended our hospital between December 2013 and December 2015 were included in the study; 18 women and 12 men with a mean age of 47.5years (30-60 years are included. Data was collected prospectively and outcomes were assessed using constant shoulder score. The mean follow-up period was 12 months (6-18 months. Mean union time of all the fractures was 11.4 weeks (8-20 weeks. The mean constant shoulder score at final review was 70.5 (52-92. Philos plate provides stable fracture fixation for proximal humerus fracture in both young and elderly patients, which enables for early mobilisation and achieves acceptable functional results.

  9. Ejecta emplacement: from distal to proximal

    Science.gov (United States)

    Artemieva, N.

    2008-09-01

    Introduction Most part of impact ejecta is deposited ballistically at some distance from a crater, defined by ejection velocity V and ejection angle α: d=v2sinα/g. In case of giant impacts, planetary curvature should be taken into account [1]. Combined with ejecta scaling [2], these relations allow to define ejecta thickness as a function of distance. Ejecta from large craters are deposited at velocity high enough to mobilize substrate material and to thicken ejecta deposits [3]. Ballistic approximation is valid for airless bodies (if impact vaporization is not vast) or for proximal ejecta of large impact craters, where ejecta mass per unit area is substantially greater than the mass of involved vapor/atmosphere (M-ratio). Deposition of distal ejecta, in which ejecta mass is negligible compared to the atmosphere, may be also treated in a simplified manner, i.e. as 1) passive motion of ejected particles within an impact plume and 2) later, as sedimentation of particles in undisturbed atmosphere (equilibrium between gravity and drag). In all intermediate M-ratio values, impact ejecta move like a surge, i.e. dilute suspension current in which particles are carried in turbulent flows under the influence of gravity. Surges are well-known for near-surface explosive tests, described in detail for volcanic explosions (Plinian column collapse, phreato-magmatic eruption, lateral blast), and found in ejecta from the Chicxulub [4] and the Ries [5]. Important aspects of surge transport include its ability to deposit ejecta over a larger area than that typical of continuous ballistic ejecta and to create multiple ejecta layers. Numerical model Two-phase hydrodynamics. Surges should be modeled in the frame of two-phase hydrodynamics, i.e. interaction between solid/molten particles and atmospheric gas/impact vapor should be taken into account. There are two techniques of solving equations for dust particle motion in a gas flow. The first one describes solid/molten particles as a

  10. Fast autonomous guidance algorithm for spacecraft far range rendezvous phasing%航天器交会远程快速自主制导方法

    Institute of Scientific and Technical Information of China (English)

    赵书阁; 陈统; 徐世杰

    2012-01-01

    针对近地近圆轨道航天器交会任务,设计了基于经典轨道要素的远程快速自主制导算法.对于任意初始纬度幅角偏差的远程导引,通过建立纬度幅角偏差与半长轴偏差的关系,将远程导引段分为初始轨道飞行、调相轨道飞行和调整轨道飞行3个阶段.初始轨道飞行进行轨道共面修正和调相机动;在调相轨道飞行期间,进行自然调相以及调相轨道到调整轨道的机动;调整轨道飞行阶段进行追踪航天器的远地点高度和近地点高度的修正,以及再次共面修正.所有变轨机动都以制导脉冲的形式给出,并都在轨道特殊点执行.精确轨道仿真验证了远程快速自主接近制导算法的可行性.%A fast autonomous guidance algorithm was designed based on classical orbital elements for spacecraft far range rendezvous phasing in near-circular orbit.For arbitrary initial argument of latitude difference,the phasing maneuver was divided into three stages—the initial orbit,the phasing orbit and the adjusting orbit according to the relationship of argument of latitude difference and semi-major axis difference.Coplanar orbital correction and phase maneuvering were done in the initial orbit.In the phasing orbit,the argument of latitude difference was adjusted naturally because of the semi-major axis difference,and then the orbit maneuver from the phasing orbit to the adjusting orbit was implemented.In the adjusting orbit,the apogee altitude and the apogee altitude of chase spacecraft are adjusted to the same as those of target spacecraft at first.Furthermore,a coplanar orbital correction was done again to eliminate the cross-track difference.All orbital maneuvers were given as guidance impulses and implemented in the orbital special points.Precise orbital simulation results show that the fast autonomous guidance algorithm for far range phasing maneuvers is feasible.

  11. Fractures of the proximal humerus involving the intertubercular groove

    Energy Technology Data Exchange (ETDEWEB)

    Ahovuo, J.; Paavolainen, P.; Bjoerkenheim, J.M. (Helsinki Univ. Central Hospital (Finland). Dept. of Radiology; Helsinki Univ. Central Hospital (Finland). Div. of Traumatology and Orthopaedic Surgery)

    The purpose of this study was to analyse the involvement of the gliding surface of the biceps tendon in fractures of the proximal humerus. Fifteen patients had a fracture of the proximal humerus verified with antero-posterior and axillary radiographs. Tangential radiographs of the intertubercular groove, obtained from the shoulder joint, showed involvement of the intertubercular groove in 13 patients (87%), which could not be shown with other projections. Groove radiographs revealed in 3 patients a dislocation of the fragments of the greater tuberosity large enough to require surgical treatment, but which had not been found using conventional techniques. Therefore, a groove radiograph should be used to precise fractures of the proximal humerus. (orig.).

  12. Specifics of proximal caries and their diagnostics in posterior teeth

    Directory of Open Access Journals (Sweden)

    Wojcik-Checinska Ilona

    2015-06-01

    Full Text Available Proximal surfaces are the second in turn after the occlusal surfaces, as being the most exposed places to the carious process. The specificity of changes and location makes the diagnostic of approximal cavities difficult. The aim of the study was to collect information on possibilities of detection, monitoring and assessment of carious lesions located on proximal surfaces, starting from the early stage. On the base of current literature, chosen methods of diagnosis, from conventional, to advanced technologies were presented. Current literature also suggests that none of the diagnostic methods exclude the possibility of misdiagnosis of proximal caries. Therefore, during the diagnosing of doubtful cases, it is advisable to employ several methods of assessment, with simultaneous individual appraisal of caries risk factors, such as oral hygiene, frequency of eating sweets or the number of active caries foci.

  13. A Flexible Proximity Sensor Fully Fabricated by Inkjet Printing

    Directory of Open Access Journals (Sweden)

    Chin-Tsan Wang

    2010-05-01

    Full Text Available A flexible proximity sensor fully fabricated by inkjet printing is proposed in this paper. The flexible proximity sensor is composed of a ZnO layer sandwiched in between a flexible aluminum sheet and a web-shaped top electrode layer. The flexible aluminum sheet serves as the bottom electrode. The material of the top electrode layer is nano silver. Both the ZnO and top electrode layers are deposited by inkjet printing. The fully inkjet printing process possesses the advantages of direct patterning and low-cost. It does not require photolithography and etching processes since the pattern is directly printed on the flexible aluminum sheet. The prototype demonstrates that the presented flexible sensor is sensitive to the human body. It may be applied to proximity sensing or thermal eradiation sensing.

  14. The thermometer of social relations: mapping social proximity on temperature.

    Science.gov (United States)

    Ijzerman, Hans; Semin, Gün R

    2009-10-01

    "Holding warm feelings toward someone" and "giving someone the cold shoulder" indicate different levels of social proximity. In this article, we show effects of temperature that go beyond these metaphors people live by. In three experiments, warmer conditions, compared with colder conditions, induced (a) greater social proximity, (b) use of more concrete language, and (c) a more relational focus. Different temperature conditions were created by either handing participants warm or cold beverages (Experiment 1) or placing them in comfortable warm or cold ambient conditions (Experiments 2 and 3). These studies corroborate recent findings in the field of grounded cognition revealing that concrete experiences ground abstract concepts with which they are coexperienced. Our studies show a systemic interdependence among language, perception, and social proximity: Environmentally induced conditions shape not only language use, but also the perception and construal of social relationships.

  15. Epiphyseal stapling of the proximal tibia for idiopathic genu valgum.

    Science.gov (United States)

    Courvoisier, Aurélien; Eid, Ahmad; Merloz, Philippe

    2009-06-01

    The purpose of this study is to evaluate the clinical and radiological outcomes of hemiepiphysiodesis with a single medial staple of the proximal tibia in idiopathic genu valgum angular correction. A retrospective review was performed identifying nine adolescents (18 knees) treated for idiopathic adolescent genu valgum by means of a bilateral hemiepiphysiodesis with a single staple of the proximal tibia. The intermalleolar distance (IMD) and hip-knee-ankle angle were measured at skeletal maturity. The IMD and hip-knee-ankle angle were reduced in all patients at skeletal maturity. Hemiepiphysiodesis with a single medial staple of the proximal tibia seems to be a reliable and safe alternative method to achieve correction of an idiopathic genu valgum.

  16. Open reduction and Internal Fixation of Displaced Proximal Humerus Fractures with AO Stainless Steel T-Plate

    Directory of Open Access Journals (Sweden)

    Hussain S

    2014-03-01

    Full Text Available Background: Proximal humeral fractures are considered the last unsolved fractures in orthopaedics. The treatment is controversial and various operative modalities have been reported in the literature. The aim of the present study was to evaluate functional outcome and complication rate after open reduction and internal fixation of displaced proximal humerus fractures by proximal humerus AO stainless steel Tplate. Twenty-five (25 patients with displaced proximal humerus fractures treated with proximal humerus T-plate between May 2005 and June 2008 were included in the study. Fractures were classified according to the Neer classification into displaced 2-part, 3-part, and 4-part fractures. Patients were followed-up for a minimum period of two years. Functional evaluation was done according to the Neer scoring system. Scores were compared with other studies in the literature using similar implant. Twenty patients had 2-part fracture, four had 3-part fracture, and one had 4-part fracture. Eighty-eight [88% (n = 22] patients had good to excellent result, eight [8% (n = 2] had fair, and four [4% (n = 1] had poor result. Difference in Neer’s score between 2-part and 3-part fractures was not significant. Complications encountered in this series were screw backout in 8% (n = 2, superficial infection in 12% (n= 3, and avascular necrosis in 4% (n = 1 of cases. We conclude that proximal humerus AO T- plate is a cheap and easily available implant, aspects which are particularly relevant in third world countries like India. It gives reliable fixation for 2-part and 3-part fractures. Its use in more complicated fracture patterns of 4-part fractures is not recommended.

  17. Proximal arm kinematics affect grip force-load force coordination.

    Science.gov (United States)

    Vermillion, Billy C; Lum, Peter S; Lee, Sang Wook

    2015-10-01

    During object manipulation, grip force is coordinated with load force, which is primarily determined by object kinematics. Proximal arm kinematics may affect grip force control, as proximal segment motion could affect control of distal hand muscles via biomechanical and/or neural pathways. The aim of this study was to investigate the impact of proximal kinematics on grip force modulation during object manipulation. Fifteen subjects performed three vertical lifting tasks that involved distinct proximal kinematics (elbow/shoulder), but resulted in similar end-point (hand) trajectories. While temporal coordination of grip and load forces remained similar across the tasks, proximal kinematics significantly affected the grip force-to-load force ratio (P = 0.042), intrinsic finger muscle activation (P = 0.045), and flexor-extensor ratio (P muscles and the elbow joint cannot fully explain the observed changes, as task-related changes in intrinsic hand muscle activation were greater than in extrinsic hand muscles. Rather, between-task variation in grip force (highest during task 3) appears to contrast to that in shoulder joint velocity/acceleration (lowest during task 3). These results suggest that complex neural coupling between the distal and proximal upper extremity musculature may affect grip force control during movements, also indicated by task-related changes in intermuscular coherence of muscle pairs, including intrinsic finger muscles. Furthermore, examination of the fingertip force showed that the human motor system may attempt to reduce variability in task-relevant motor output (grip force-to-load force ratio), while allowing larger fluctuations in output less relevant to task goal (shear force-to-grip force ratio).

  18. Modular endoprosthetic replacement for metastatic tumours of the proximal femur

    Directory of Open Access Journals (Sweden)

    Carter Simon R

    2008-11-01

    Full Text Available Abstract Background and aims Endoprosthetic replacements of the proximal femur are commonly required to treat destructive metastases with either impending or actual pathological fractures at this site. Modular prostheses provide an off the shelf availability and can be adapted to most reconstructive situations for proximal femoral replacements. The aim of this study was to assess the clinical and functional outcomes following modular tumour prosthesis reconstruction of the proximal femur in 100 consecutive patients with metastatic tumours and to compare them with the published results of patients with modular and custom made endoprosthetic replacements. Methods 100 consecutive patients who underwent modular tumour prosthetic reconstruction of the proximal femur for metastases using the METS system from 2001 to 2007 were studied. The patient, tumour and treatment factors in relation to overall survival, local control, implant survival and complications were analysed. Functional scores were obtained from surviving patients. Results and conclusion There were 45 male and 55 female patients. The mean age was 60.2 years. The indications were metastases. Seventy five patients presented with pathological fracture or with failed fixation and 25 patients were at a high risk of developing a fracture. The mean follow up was 15.9 months [range 0–77]. Three patients died within 2 weeks following surgery. 69 patients have died and 31 are alive. Of the 69 patients who were dead 68 did not need revision surgery indicating that the implant provided single definitive treatment which outlived the patient. There were three dislocations (2/5 with THR and 1/95 with unipolar femoral heads. 6 patients had deep infections. The estimated five year implant survival (Kaplan-Meier analysis was 83.1% with revision as end point. The mean TESS score was 64% (54%–82%. We conclude that METS modular tumour prosthesis for proximal femur provides versatility; low implant related

  19. PROXIMAL POINT ALGORITHM FOR MINIMIZATION OF DC FUNCTION

    Institute of Scientific and Technical Information of China (English)

    Wen-yu Sun; Raimundo. J.B. Sampaio; M.A.B. Candido

    2003-01-01

    In this paper we present some algorithms for minimization of DC function (difference of two convex functions). They are descent methods of the proximal-type which use the convex properties of the two convex functions separately. We also consider an approximate proximal point algorithm. Some properties of the ε-subdifferential and the ε-directional derivative are discussed. The convergence properties of the algorithms are established in both exact and approximate forms. Finally, we give some applications to the concave programming and maximum eigenvalue problems.

  20. Longitudinal spin Seebeck effect free from the proximity Nernst effect.

    Science.gov (United States)

    Kikkawa, T; Uchida, K; Shiomi, Y; Qiu, Z; Hou, D; Tian, D; Nakayama, H; Jin, X-F; Saitoh, E

    2013-02-08

    This Letter provides evidence for intrinsic longitudinal spin Seebeck effects (LSSEs) that are free from the anomalous Nernst effect (ANE) caused by an extrinsic proximity effect. We report the observation of LSSEs in Au/Y(3)Fe(5)O(12) (YIG) and Pt/Cu/YIG systems, showing that the LSSE appears even when the mechanism of the proximity ANE is clearly removed. In the conventional Pt/YIG structure, furthermore, we separate the LSSE from the ANE by comparing the voltages in different magnetization and temperature-gradient configurations; the ANE contamination was found to be negligibly small even in the Pt/YIG structure.

  1. Bizarre parosteal osteochondromatous proliferation of the proximal humerus: case report

    Energy Technology Data Exchange (ETDEWEB)

    Bush, J.B.; Meyer, Mark S. [Ochsner Clinic Foundation, Department of Orthopedics, New Orleans, LA (United States); Reith, John D. [University of Florida College of Medicine, Departments of Pathology, Immunology and Laboratory Medicine and Orthopaedics and Rehabilitation, Gainesville, Florida (United States)

    2007-06-15

    Bizarre parosteal osteochondromatous proliferation (BPOP), or Nora's lesion, is a rare lesion of bone occurring predominantly in the long bones of the hands and feet. It exists as a puzzling clinical entity of uncertain origins and high recurrence rates after surgical resection. To our knowledge, this clinical entity has not been reported in the proximal aspect of the humerus. An interesting report of a lesion occurring in the proximal humerus, which initially was misinterpreted as a parosteal osteosarcoma, is discussed outlining the clinical, radiographic and pathologic features of the BPOP lesion. (orig.)

  2. A note on unibasic spaces and transitive quasi-proximities

    OpenAIRE

    Adalberto García-Máynez; Adolfo Pimienta Acosta

    2017-01-01

    [EN] In this paper we prove there is a bijection between the set of all annular bases of a topological spaces $(X,\\tau)$ and the set of all transitive quasi-proximities on $X$ inducing $\\tau$.We establish some properties of those topological spaces $(X,\\tau)$ which imply that $\\tau$ is the only annular basis García-Máynez, A.; Pimienta Acosta, A. (2017). A note on unibasic spaces and transitive quasi-proximities. Applied General Topology. 18(1):23-30. doi:10.4995/agt.2017.4092. 23 30...

  3. Premaceral contents of peats correlated with proximate and ultimate analysis

    Energy Technology Data Exchange (ETDEWEB)

    Cohen, A.D.; Andrejko, M.J.

    1983-01-01

    Preliminary correlations of petrographic characteristics of peats (i.e., peat types, premaceral proportions, and premaceral types) with proximate analysis, ultimate analysis, and Btu content are reported. These correlations suggest the following trends: (1) peats with the highest proportions of birefringent macerals tend to have highest volatile matter (and H and O contents); (2) fluorescence of macerals seems to correlate only slightly with proximate and ultimate analyses; (3) higher previtrinite contents tend to correlate with higher volatile matter contents; (4) peats with higher preinertinities, prephlobaphenites (and precorpocollinites), and presclerotinites have the highest fixed carbon; and (5) Btu correlates strongly with ash content and only slightly with maceral content. (BLM)

  4. Modelling and Analysis of Proximity Effect in IGBT Fuses

    DEFF Research Database (Denmark)

    Iov, Florin; Blaabjerg, Frede; Rasmussen, Henrik

    2005-01-01

    . Even with an active protection, a high power IGBT still has a risk of exhibiting a violent rupture in the case of a fault if e.g. IGBT fuses are not protecting it. By introducing fuses into voltage source converters a better protection of IGBT's can be achieved. However, skin and proximity effects...... affect the current distribution in a fuse due to the high frequency currents and thus a need for de-rating the fuse. This paper shows an analytical model for studying the proximity effect into a fuse. The results obtained using this model are compared with experiments....

  5. Inverse Proximity Effect in Superconductor-ferromagnet Bilayer Structures

    Energy Technology Data Exchange (ETDEWEB)

    Xia, Jing

    2010-04-05

    Measurements of the polar Kerr effect using a zero-area-loop Sagnac magnetometer on Pb/Ni and Al/(Co-Pd) proximity-effect bilayers show unambiguous evidence for the 'inverse proximity effect,' in which the ferromagnet (F) induces a finite magnetization in the superconducting (S) layer. To avoid probing the magnetic effects in the ferromagnet, the superconducting layer was prepared much thicker than the light's optical penetration depth. The sign and size of the effect, as well as its temperature dependence agree with recent predictions by Bergeret et al.[1].

  6. Efficient Indoor Proximity and Separation Detection for Location Fingerprinting

    DEFF Research Database (Denmark)

    Kjærgaard, Mikkel Baun; Treu, Georg; Ruppel, Peter

    2008-01-01

    Detecting proximity and separation among mobile targets is a basic mechanism for many location-based services (LBSs) and requires continuous positioning and tracking. However, realizing both mechanisms for indoor usage is still a major challenge. Positioning methods like GPS cannot be applied there......, and for distance calculations the particular building topology has to be taken into account. To address these challenges, this paper presents a novel approach for indoor proximity and separation detection, which uses location fingerprinting for indoor positioning of targets and walking distances for modeling...

  7. Thruster Plume Contamination in Spacecraft Rendezvous and Docking Mission Based on Liquid-phase Model%基于液相污染模型的航天器交会对接羽流污染研究

    Institute of Scientific and Technical Information of China (English)

    石泳; 张健

    2011-01-01

    航天器交会对接任务一般由主动对接方和被动目标配合完成,交会对接飞行的主动寻的段和分离撤离段均可能出现主动对接方开启反向发动机进行反向紧急制动和撤离的情况,该情况下被动目标可能受到来自主动方反向发动机羽流污染影响。文章利用国际空间站羽流污染计算模型对交会对接任务羽流污染沉积进行了分析计算。%The spacecraft rendezvous and docking mission consists of one pursuit spacecraft and one target spacecraft. In the condition of brake or leave maneuver, there will be some plume contamination jetted from the thrusters of the pursuit one. Some sensitive apparatus of the target spacecraft could be affected by the contamination and their performance would also be damaged. This paper has introduced the bipropellant liquid-phase plume contamination model of International Space Station to analyze the mount of contamination in the rendezvous and docking mission. The method of this study could help to improve feasibility of the mission.

  8. Planning and Optimization Algorithms of Phasing Orbit Manoeuvres in Rendezvous and Docking%交会对接远程导引轨道控制状态规划与优化算法

    Institute of Scientific and Technical Information of China (English)

    伍升钢; 侯黎强; 张智斌; 谭炜; 李恒年

    2012-01-01

    对空间交会对接远程导引段轨道控制问题进行了研究.在简单介绍交会对接远程导引轨道控制实时规划模型的基础上,提出了基于近圆偏差方程、序列二次规划算法和目标权重函数等在不同控制目标模式下的状态规划与优化算法.仿真结果表明,该算法收敛速度快,能较好地满足交会对接远程导引段的轨道控制要求,具有一定的工程实用价值.%Phasing of orbit maneuvers in space rendezvous and docking in the remote guidance phase is studied. Following a brief introduction of the real-time planning model for phasing of orbit maneuvers in space rendezvous and docking, state planning and optimization algorithms in different modes based on near-circular deviation equations, sequential quadratic programming and target weighting function are proposed. Simulation results show that the algorithms converge quickly and well meet the requirements of phasing of orbit maneuvers in the remote guidance phase.

  9. 基于微分几何与李群的无人机编队会合方法%UAVs formation rendezvous method based on differential geometry and Lie group

    Institute of Scientific and Technical Information of China (English)

    李杰; 彭双春; 安宏雷; 相晓嘉; 沈林成

    2013-01-01

    With the leader-follower formation pattern,a method for UAV formation rendezvous was developed based on the pursuit strategy. Firstly,the UAV non-decoupling 3D kinematics models were established by using the curve theory of differential geometry and the Frenet-Serret frames,where the curvature and the torsion were considered as the control effort.Secondly,the mathematical descriptions of the three-dimensional formation rendezvous were provided with the models,where the impact angular constraint in missile guidance was mapped to a flight path angle of the follower in formation rendezvous,and an additional azimuth angular constraint was introduced.Thirdly,the orientation deviation between the leader and the follower was measured by using an element of the special orthogonal group,and the element was mapped to a twist in an Lie algebra space corresponding to the Lie group by local coordinate mapping.Then,a geometric guidance law for formation rendezvous was developed by using the twist,and the corresponding curvature command and torsion command were presented.Finally,the numerical simulation for multi-UAVs formation rendezvous was carried out,under the leader flying straightly and making a turn,respectively.The simulation results show that the follower can track the orientation of the leader successfully and can converge to a specified configuration,which indicates that the proposed method is available.%在领航-跟随编队模式下,设计了一种基于追缉策略的无人机编队会合方法。基于微分几何曲线论和弗雷涅-塞雷标架建立了无人机非解耦三维运动模型,其中将曲率和挠率作为控制量;结合该模型给出了无人机三维编队会合问题的数学描述,它将导弹制导问题中的终端落角约束映射为编队会合问题中僚机的航迹倾角约束,同时引入额外的航迹方位角约束;使用特殊正交群的元素来度量长僚机方向偏差,并通过局部坐标映射将其映射

  10. Correction of Hallux Valgus Interphalangeus With an Osteotomy of the Distal End of the Proximal Phalanx (Distal Akin Osteotomy).

    Science.gov (United States)

    Vander Griend, Robert

    2017-02-01

    Operative correction of a symptomatic hallux valgus interphalangeus (HVI) deformity is often achieved with an osteotomy at the proximal end of the proximal phalanx (Akin osteotomy). However, the apex of the typical HVI deformity (center of rotation angle) is at the interphalangeal joint of the hallux. This study was done to evaluate the results of performing a medial closing wedge osteotomy at the distal end of the proximal phalanx. Thirty-three patients (33 feet) underwent an osteotomy at the distal end of the proximal phalanx for correction of HVI. All of the patients had other forefoot deformities which were corrected at the same time. Eight of these were revision procedures of prior forefoot operations. The length of follow-up was determined by the associated procedures with a minimum follow-up of 4 months. The preoperative hallux valgus interphalangeus angle averaged 16 degrees of valgus (range 7-32 degrees) and was corrected to an average of 2 degrees of valgus (range 5 degrees valgus to 5 degrees varus). All of the patients were satisfied with the postoperative appearance and function of the first toe. Because of simultaneous correction of numerous other forefoot problems, it was not possible to specifically isolate or evaluate the effects and benefits of this osteotomy using outcomes measures. There was one intraoperative complication resulting in a fracture extending into the adjacent IP joint. Correction of an HVI deformity can be achieved with an osteotomy at the distal end of the proximal phalanx. This was a safe technique with few complications and with good results in terms of both correction and patient satisfaction. Level IV, retrospective case series.

  11. Diagnostic accuracy of digital images for detection of artificial chemical proximal caries

    Energy Technology Data Exchange (ETDEWEB)

    Park, Geum Mee; Nah, Kyung Soo [Pusan National University College of Medicine, Busan (Korea, Republic of)

    2003-06-15

    To compare the diagnostic accuracy of proximal caries detection between Kodak Insight film and the Biomedisys CDX2000HQ digital (CCD) sensor. 156 proximal surfaces of extracted teeth, 78 of which had chemical artificial caries, were used in this study. Four observers interpreted the radiographs using a five-point confidence rating scale to record their diagnoses. The results were analyzed by receiver operating characteristic curves, ANOVA and Kappa values. Analysis using receiver operating characteristic curves revealed the areas under each curve which indicated a diagnostic accuracy of 0.951 in Insight and 0.952 in CDX2000HQ digital sensor. ANOVA revealed no significant differences between the two images with respect to caries detection. Kappa values indicated that the mean intra-observer agreement was 0.85 and inter-observer agreement 0.71 in conventional radiography. In digital radiography, the mean intra-observer agreement was 0.84 and inter-observer agreement 0.72. The results suggest that no significant difference exists between the two modalities for artificial caries detection and that CDX2000HQ was as good as Insight film for this purpose.

  12. SURGICAL MANAGEMENT OF INTERTROCHANTERIC FRACTURES : A STUDY USING DYNAMIC HIP SCREW AND PROXIMAL FEMORAL NAIL

    Directory of Open Access Journals (Sweden)

    Venkateswara Rao

    2015-08-01

    Full Text Available OBJECTIVES: The aim of this study was to compare the outcome of intertrochanteric fractures treated with Dynamic Hip Screw and Proximal Femoral nail. METHODS: This study was conducted on 80 cases of Intertrochanteric fractures of femur treated by a dynamic hip screw and proximal femoral nail. Patients were operated on standard fracture table under image intensifier control. RESULTS: The average age of the patient was 63.2 years. Most common mechanism of fracture was domestic fall. The unstable pattern was more common in old aged patients with higher grade of osteoporosis. The average blood loss was 240 and 320ml in PFN and DHS group respectively. In PFN there were more no. of radiation exposure intraoperatively. The average operating time for the patients treated with PFN was 100min as compared to 80 min in patients treated with DHS. No complications of non - union and infection. In the PFN group the amount of sliding on X - rays was less as compared to DHS. The patients treated with PFN started early ambulation as they had better Harris Hip Score in the early period (at 1 and 3 month. In the long term both the implant had almost similar functional outcomes. CONCLUSION: From the study, we concluded PFN is better alternative to DHS in management of intertrochanteric fractures but is technically difficult procedure and requires more expertise compared to DHS.

  13. Proximal Tibial Epiphysis Injury (Flexion Type, Salter-Harris Type 1).

    Science.gov (United States)

    Israni, Pratik; Panat, Mangesh

    2016-01-01

    Fractures of the proximal tibial epiphysis rare. It has been estimated that fractures of the upper tibial epiphysis account for 0.5-3.1% of all epiphyseal injuries. Who had no neurovascular deficit, with fixed extension deformity at the left knee was treated early with closed reduction techniques. We present a case of a 16-year-old boy who while playing cricket on the road was hit by a car. The patient presented in emergency room with extremely swollen knee and soft tissue swelling (hemarthrosis), he was unable to lift his leg actively due to severe pain because of hamstrings spasm, and he had no wound over his left knee and had no other associated injuries. Plain radiographs were taken which revealed, separated proximal tibial epiphysis (salter harris Type 1 injury) The epiphysis was anteriorly displaced fracture line extending beyond growth plate through metaphysis and tibial tuberosity also displaced anteriorly, the proximal fibular epiphysis fragment was displaced anteriorly with no injury to femoral epiphysis and no patellar fracture, radiograph also revealed no intra-articular fracture as joint appears congruent. Under spinal anesthesia, under all aseptic precautions traction was applied for few minutes, the fracture was reduced closed as the hamstring spasm gave way, reduction was confirmed under image intensifier in both AP and lateral planes, and joint congruity was examined. Proximal fibular epiphysis also snapped back in place. Post-operative patient was immobilized with nil weight bearing for 4 weeks, check X-rays taken, he was mobilized in wheelchair. After 4 weeks slab was removed, K-wires were removed, and partial weight bearing was started with rehabilitation for full range of motion of the left knee. At 6 weeks, both the knee joints appeared symmetrical with no abnormalities or limb length discrepancy or instability with knee from 0° to 140°, with full weight bearing. Although less commonly seen, Salter-Harris Type 1 injuries to proximal tibial

  14. Proximal Tibial Epiphysis Injury (Flexion Type, Salter–Harris Type 1)

    Science.gov (United States)

    Israni, Pratik; Panat, Mangesh

    2016-01-01

    Introduction: Fractures of the proximal tibial epiphysis rare. It has been estimated that fractures of the upper tibial epiphysis account for 0.5-3.1% of all epiphyseal injuries. Who had no neurovascular deficit, with fixed extension deformity at the left knee was treated early with closed reduction techniques. Case Report: We present a case of a 16-year-old boy who while playing cricket on the road was hit by a car. The patient presented in emergency room with extremely swollen knee and soft tissue swelling (hemarthrosis), he was unable to lift his leg actively due to severe pain because of hamstrings spasm, and he had no wound over his left knee and had no other associated injuries. Plain radiographs were taken which revealed, separated proximal tibial epiphysis (salter harris Type 1 injury) The epiphysis was anteriorly displaced fracture line extending beyond growth plate through metaphysis and tibial tuberosity also displaced anteriorly, the proximal fibular epiphysis fragment was displaced anteriorly with no injury to femoral epiphysis and no patellar fracture, radiograph also revealed no intra-articular fracture as joint appears congruent. Under spinal anesthesia, under all aseptic precautions traction was applied for few minutes, the fracture was reduced closed as the hamstring spasm gave way, reduction was confirmed under image intensifier in both AP and lateral planes, and joint congruity was examined. Proximal fibular epiphysis also snapped back in place. Post-operative patient was immobilized with nil weight bearing for 4 weeks, check X-rays taken, he was mobilized in wheelchair. After 4 weeks slab was removed, K-wires were removed, and partial weight bearing was started with rehabilitation for full range of motion of the left knee. At 6 weeks, both the knee joints appeared symmetrical with no abnormalities or limb length discrepancy or instability with knee from 0° to 140°, with full weight bearing. Conclusion: Although less commonly seen, Salter

  15. Acute lower gastrointestinal bleeding from a dieulafoy lesion proximal to the anorectal junction post-orthotopic liver transplant

    Institute of Scientific and Technical Information of China (English)

    Wichian Apiratpracha; Jin Kee Ho; James J Powell; Eric M Yoshida

    2006-01-01

    A 67-year-old woman underwent an orthotopic liver transplantation for end stage liver disease secondary to chronic autoimmune hepatitis. She developed sudden massive hematochezia on post-operative day 23 with hemodynamic compromise. The source of hemorrhage was found at colonoscopy after careful irrigation and inspection to be a dieulafoy lesion situated just proximal to the anorectal junction. Hemostasis was achieved with epinephrine injection and thermal coagulation.

  16. INVISTA Rendez-Vous 2008

    Institute of Scientific and Technical Information of China (English)

    By Shang Lin'aiyi

    2008-01-01

    @@ INVISTA,the leading global innovator of fiber technology,has opened the sixth INVISTA Re0dez-Vous showcasing its fiber technology breakthroughs that enable customers to gain a competitive edge in their products with innovations.

  17. Proximal rectus femoris avulsion in an elite, olympic-level sprinter.

    Science.gov (United States)

    Langer, Phillip R; Selesnick, Harlan

    2010-11-01

    Quadriceps injuries, ranging from simple strains to disabling muscle ruptures, are common athletic injuries. The rectus femoris is the most commonly injure portion of the quadriceps musculature. This article is, to our knowledge, the first report of a proximal rectus femoris avulsion in an elite, Olympic-level 100-meter sprinter, acutely managed with surgical repair. Several key factors must be considered and carefully assessed when determining the appropriate course of management (ie, deciding between operative and nonoperative treatment): amount of distal retraction of the tendon, severity of associated soft-tissue trauma, physical examination, and postoperative goals (eg, return to elite-level competitive sports involving running or kicking vs resuming basic activities of daily living). We believe that these factors in our elite, high-performance athlete dictated an operative course of management.

  18. Establishment of a proximate analysis of coal based on the use of a thermobalance

    Energy Technology Data Exchange (ETDEWEB)

    Matsumoto, S.; Watanuki, O.

    1986-01-01

    Studies are reported aimed at the establishment of a new method for the proximate analysis of coal. The results obtained are expected to clear the way for the introduction of this thermogravimetric method. Firstly, in order to achieve a repeatability as good as that of the JIS method and such that operating problems do not result at power plants, measurement procedures were standardized on the basis of an analysis of the factors affecting repeatability. Secondly, a regression analysis was carried out to check the correspondence between the JIS method and the thermogravimetric method over a practical operating range and for all the types of coal presently received at power plants. This analysis confirmed the linearity of the relations between the two sets of results. 2 references, 4 figures.

  19. Fully automatic apparatus for proximate analysis and total sulfur analysis of coal and coke

    Energy Technology Data Exchange (ETDEWEB)

    Ishibashi, Y.; Fukumoto, K.; Maeda, K.; Ogawa, A.; Goto, K.; Ishii, T.

    1987-02-01

    For the purpose of saving labor and improving working conditions, the full automatic apparatus for the proximate analysis and total sulfur analysis of coal and coke was developed. Objects of this automation were to quantify inherent moisture, ash, volatile matter and total sulfur. Quantitative determination of inherent moisture, ash and volatile matter was made gravimetrically. Total sulfur was measured by combustion and acid and base titration, using a conductivity glass electrode sensor. The robot was set to the center of the automatic apparatus and relevant apparatuses were arranged in concentric circular locations. The computer carried out condition control of each apparatus, sequence control by operating demand and operation completing signal, and progress control of analysis. Very high correlation between the conventional method and this automatic method was confirmed. 4 refs., 9 figs., 3 tabs.

  20. A Monocular SLAM Method to Estimate Relative Pose During Satellite Proximity Operations

    Science.gov (United States)

    2015-03-26

    HOMER video sequence in Figure 17) provides the relative rotation and translation required from the perspective of the camera for successful...shows the SLAM results, with the camera models representing the relative pose estimates of the camera on the arm. Figure 40 shows another perspective of...ensures initialization is performed with adequate relative motion. If no additional perspective information is obtained in an initialization attempt, a