WorldWideScience

Sample records for fracture control design

  1. Design, fracture control, fabrication, and testing of pressurized space-vehicle structures

    Science.gov (United States)

    Babel, H. W.; Christensen, R. H.; Dixon, H. H.

    1974-01-01

    The relationship between analysis, design, fabrication, and testing of thin shells is illustrated by Saturn S-IVB, Thor, Delta, and other single-use and reusable large-size cryogenic aluminum tankage. The analyses and design to meet the design requirements are reviewed and include consideration of fracture control, general instability, and other failure modes. The effect of research and development testing on the structure is indicated. It is shown how fabrication and nondestructive and acceptance testing constrain the design. Finally, qualification testing is reviewed to illustrate the extent of testing used to develop the Saturn S-IVB.

  2. Design and real-time control of a robotic system for fracture manipulation.

    Science.gov (United States)

    Dagnino, G; Georgilas, I; Tarassoli, P; Atkins, R; Dogramadzi, S

    2015-08-01

    This paper presents the design, development and control of a new robotic system for fracture manipulation. The objective is to improve the precision, ergonomics and safety of the traditional surgical procedure to treat joint fractures. The achievements toward this direction are here reported and include the design, the real-time control architecture and the evaluation of a new robotic manipulator system. The robotic manipulator is a 6-DOF parallel robot with the struts developed as linear actuators. The control architecture is also described here. The high-level controller implements a host-target structure composed by a host computer (PC), a real-time controller, and an FPGA. A graphical user interface was designed allowing the surgeon to comfortably automate and monitor the robotic system. The real-time controller guarantees the determinism of the control algorithms adding an extra level of safety for the robotic automation. The system's positioning accuracy and repeatability have been demonstrated showing a maximum positioning RMSE of 1.18 ± 1.14mm (translations) and 1.85 ± 1.54° (rotations).

  3. The efficacy of rotational control designs in promoting torsional stability of hip fracture fixation.

    Science.gov (United States)

    Gosiewski, J D; Holsgrove, T P; Gill, H S

    2017-05-01

    Fractures of the proximal femur are a common clinical problem, and a number of orthopaedic devices are available for the treatment of such fractures. The objective of this study was to assess the rotational stability, a common failure predictor, of three different rotational control design philosophies: a screw, a helical blade and a deployable crucifix. Devices were compared in terms of the mechanical work (W) required to rotate the implant by 6° in a bone substitute material. The substitute material used was Sawbones polyurethane foam of three different densities (0.08 g/cm 3 , 0.16 g/cm 3 and 0.24 g/cm 3 ). Each torsion test comprised a steady ramp of 1°/minute up to an angular displacement of 10°. The deployable crucifix design (X-Bolt), was more torsionally stable, compared to both the dynamic hip screw (DHS, p = 0.008) and helical blade (DHS Blade, p= 0.008) designs in bone substitute material representative of osteoporotic bone (0.16 g/cm 3 polyurethane foam). In 0.08 g/cm 3 density substrate, the crucifix design (X-Bolt) had a higher resistance to torsion than the screw (DHS, p = 0.008). There were no significant differences (p = 0.101) between the implants in 0.24 g/cm 3 density bone substitute. Our findings indicate that the clinical standard proximal fracture fixator design, the screw (DHS), was the least effective at resisting torsional load, and a novel crucifix design (X-Bolt), was the most effective design in resisting torsional load in bone substitute material with density representative of osteoporotic bone. At other densities the torsional stability was also higher for the X-Bolt, although not consistently significant by statistical analysis. Cite this article : J. D. Gosiewski, T. P. Holsgrove, H. S. Gill. The efficacy of rotational control designs in promoting torsional stability of hip fracture fixation. Bone Joint Res 2017;6:270-276. DOI: 10.1302/2046-3758.65.BJR-2017-0287.R1. © 2017 Gosiewski et al.

  4. Fracture mechanisms and fracture control in composite structures

    Science.gov (United States)

    Kim, Wone-Chul

    Four basic failure modes--delamination, delamination buckling of composite sandwich panels, first-ply failure in cross-ply laminates, and compression failure--are analyzed using linear elastic fracture mechanics (LEFM) and the J-integral method. Structural failures, including those at the micromechanical level, are investigated with the aid of the models developed, and the critical strains for crack propagation for each mode are obtained. In the structural fracture analyses area, the fracture control schemes for delamination in a composite rib stiffener and delamination buckling in composite sandwich panels subjected to in-plane compression are determined. The critical fracture strains were predicted with the aid of LEFM for delamination and the J-integral method for delamination buckling. The use of toughened matrix systems has been recommended for improved damage tolerant design for delamination crack propagation. An experimental study was conducted to determine the onset of delamination buckling in composite sandwich panel containing flaws. The critical fracture loads computed using the proposed theoretical model and a numerical computational scheme closely followed the experimental measurements made on sandwich panel specimens of graphite/epoxy faceskins and aluminum honeycomb core with varying faceskin thicknesses and core sizes. Micromechanical models of fracture in composites are explored to predict transverse cracking of cross-ply laminates and compression fracture of unidirectional composites. A modified shear lag model which takes into account the important role of interlaminar shear zones between the 0 degree and 90 degree piles in cross-ply laminate is proposed and criteria for transverse cracking have been developed. For compressive failure of unidirectional composites, pre-existing defects play an important role. Using anisotropic elasticity, the stress state around a defect under a remotely applied compressive load is obtained. The experimentally

  5. Design guidance for fracture-critical components at Lawrence Livermore National Laboratory

    International Nuclear Information System (INIS)

    Streit, R.D.

    1982-01-01

    Fracture is an important design consideration for components whose sudden and catastrophic failure could result in a serious accident. Elements of fracture control and fracture mechanics design methods are reviewed. Design requirements, which are based on the consequences of fracture of a given component, are subsequently developed. Five categories of consequences are defined. Category I is the lowest risk, and relatively lenient design requirements are employed. Category V has the highest potential for injury, release of hazardous material, and damage. Correspondingly, the design requirements for these components are the most stringent. Environmental, loading, and material factors that can affect fracture safety are also discussed

  6. Designing tough and fracture resistant polypropylene/multi wall carbon nanotubes nanocomposites by controlling stereo-complexity and dispersion morphology

    International Nuclear Information System (INIS)

    Das, Dibyendu; Satapathy, Bhabani K.

    2014-01-01

    Highlights: • New pathway to improve dispersion and toughness by tacticity modification. • >330% toughness enhancement in PP/MWCNT nanocomposites with stereo-complex PP. • Prominent dispersion and distribution morphology due to matrix stereocomplexity. • Tacticity induced “Semi-ductile-to-tough-to-quasi-brittle” transitions in the PP/MWCNT. • Two-fold reduced steady state CTOD rate in i-PP+s-PP/ MWCNT nanocomposites. - Abstract: A remarkable toughness enhancement (>330%) of multi wall carbon nanotubes (MWCNT) filled stereo-complex polypropylene (PP) matrix i.e. blend of isotactic-PP and syndiotactic-PP (70:30) with differences in stereo-regularity has been observed. The enhancement has been correlated to quantifiable morphological parameters such as free-space lengths concerning dispersion and relatively greater reduction in crystallite size/lamellar thickness. Systematic analysis of glass transition data and estimation of multi wall carbon nanotubes induced reduction in interfacial polymer chain immobilization reiterates susceptibility of polymer segments to ready-mobility. The extent of toughening has quantitatively been analyzed by fracture-energy partitioning, essential work of fracture (EWF), approach enabling the detection of a “semi-ductile-to-tough-to-quasi-brittle” transition in the MWCNT filled stereo-complex polypropylene. Real-time fracture kinetics analysis revealed toughening mechanism to be primarily blunting-assisted; an aspect also corroborated by extensive plastic flow without much energy dissipation in the inner fracture process zone. Thus the study establishes a new pathway of tacticity-defined matrix modification to toughen nanocomposites

  7. Clinical effects of internal fixation for ulnar styloid fractures associated with distal radius fractures: A matched case-control study.

    Science.gov (United States)

    Sawada, Hideyoshi; Shinohara, Takaaki; Natsume, Tadahiro; Hirata, Hitoshi

    2016-11-01

    Ulnar styloid fractures are often associated with distal radius fractures. However, controversy exists regarding whether to treat ulnar styloid fractures. This study aimed to evaluate clinical effects of internal fixation for ulnar styloid fractures after distal radius fractures were treated with the volar locking plate system. We used prospectively collected data of distal radius fractures. 111 patients were enrolled in this study. A matched case-control study design was used. We selected patients who underwent fixation for ulnar styloid fractures (case group). Three control patients for each patient of the case group were matched on the basis of age, sex, and fracture type of distal radius fractures from among patients who did not undergo fixation for ulnar styloid fractures (control group). The case group included 16 patients (7 men, 9 women; mean age: 52.6 years; classification of ulnar styloid fractures: center, 3; base, 11; and proximal, 2). The control group included 48 patients (15 men, 33 women; mean age: 61.1 years; classification of ulnar styloid fractures: center, 10; base, 31; and proximal, 7). For radiographic examination, the volar tilt angle, radial inclination angle, and ulnar variance length were measured, and the union of ulnar styloid fractures was judged. For clinical examination, the range of motions, grip strength, Hand20 score, and Numeric Rating Scale score were evaluated. There was little correction loss for each radiological parameter of fracture reduction, and these parameters were not significantly different between the groups. The bone-healing rate of ulnar styloid fractures was significantly higher in the case group than in the control group, but the clinical results were not significantly different. We revealed that there was no need to fix ulnar styloid fractures when distal radius fractures were treated via open reduction and internal fixation with a volar locking plate system. Copyright © 2016 The Japanese Orthopaedic Association

  8. Design considerations of a randomized controlled trial of sedation level during hip fracture repair surgery: a strategy to reduce the incidence of postoperative delirium in elderly patients.

    Science.gov (United States)

    Li, Tianjing; Wieland, L Susan; Oh, Esther; Neufeld, Karin J; Wang, Nae-Yuh; Dickersin, Kay; Sieber, Frederick E

    2017-06-01

    Background Delirium is an acute change in mental status characterized by sudden onset, fluctuating course, inattention, disorganized thinking, and abnormal level of consciousness. The objective of the randomized controlled trial "A STrategy to Reduce the Incidence of Postoperative Delirium in Elderly Patients" (STRIDE) is to assess the effectiveness of light versus heavy sedation on delirium and other outcomes in elderly patients undergoing hip fracture repair surgery. Our goal is to describe the design considerations and lessons learned in planning and implementing the STRIDE trial. Methods Discussed are challenges encountered including (1) how to ensure that we quickly identify, assess the eligibility of, and randomize traumatic hip fracture patients; (2) how to implement interventions that involve continuous monitoring and adjustment during the surgery; and (3) how to measure and ascertain the primary outcome, delirium. Results To address the first challenge, we monitored the operating room schedule more actively than anticipated. We constructed and organized eligibility assessment data collection forms by purpose and by source of information needed to complete them. We decided that randomization needs to take place in the operating room. To address the second challenge, we designed and implemented a treatment protocol and covered the bispectral index monitor to prevent the Anesthesiologist/Anesthetist from being influenced by the bispectral index reading while administering the intervention. Finally, clinical assessment of delirium consisted of standardized interviews of the patient using validated instruments, interviews of those caring for the patient, and review of the medical record. A consensus panel made the final determination of a delirium diagnosis. We note that STRIDE is a single-center trial. The decisions we took may have different implications for multi-center trials. Conclusions Lessons learned are likely to provide useful information to others

  9. Controlling fracture cascades through twisting and quenching

    OpenAIRE

    Heisser, Ronald H.; Patil, Vishal P.; Stoop, Norbert; Dunkel, Jörn

    2018-01-01

    Fracture limits the structural stability of macroscopic and microscopic materials, from beams and bones to microtubules and nanotubes. Despite recent progress, fracture control continues to present profound practical and theoretical challenges. A famous longstanding problem posed by Feynman asks why brittle elastic rods appear almost always to fragment into at least three pieces when placed under large bending stresses. Feynman's observation raises fundamental questions about the existence of...

  10. Effectiveness of Oral Nutritional Supplementation for Older Women after a Fracture: Rationale, Design and Study of the Feasibility of a Randomized Controlled Study

    Directory of Open Access Journals (Sweden)

    Lockwood Keri A

    2011-06-01

    Full Text Available Abstract Background Malnutrition is a problem for many older people recovering from a hip and other major fractures. Oral supplementation with high calorie high protein nutrients is a simple intervention that may help older people with fractures to improve their recovery in terms of rehabilitation time, length of hospital stay and mortality. This paper reports a pilot study to test the feasibility of a trial initiated in a hospital setting with an oral supplement to older people with recent fractures. Method A randomized controlled trial with 44 undernourished participants admitted to a hospital following a fracture. The intervention group (n = 23 received a high calorie high protein supplement for forty days in addition to their diet of choice. The control group (n = 21 received high protein milk during their hospital stay in addition to their diet of choice and their usual diet when discharged from hospital. Results All participants were women and their mean age was 85.3 (± 6.1 years. Twenty nine (65% participants had a hip fracture. At baseline no differences were measured between the two groups regarding their nutritional status, their cognitive ability or their abilities in activities of daily living. There were no significant differences between the intervention and control group with reference to nutritional or functional parameters at 40 day and 4 month follow-ups. Median length of stay in hospital was 18.0 days, with 12 participants being readmitted for a median of 7.0 days. Conclusion It is feasible to perform a randomised trial in a hospital and community setting to test the effect of an oral high energy high protein supplement for older people. Due to the limited number of participants and incomplete adherence with use of the supplements no conclusion can be drawn about the efficacy or effectiveness of this intervention.

  11. Fracturing Fluid Leak-off for Deep Volcanic Rock in Zhungeer Basin: Mechanism and Control Method

    Directory of Open Access Journals (Sweden)

    Huang Bo

    2017-01-01

    Full Text Available The deep volcanic reservoir in Zhungeer Basin is buried in over 4000m depth, which is characterized by complex lithology (breccia, andesite, basalt, etc., high elastic modulus and massive natural fractures. During hydraulic fracturing, hydraulic fracture will propagate and natural fractures will be triggered by the increasing net pressure. However, the extension of fractures, especially natural fractures, would aggravate the leak-off effect of fracturing fluid, and consequently decrease the fracturing success rate. 4 out of 12 fracturing wells in the field have failed to add enough proppants due to fluid loss. In order to increase the success rate and efficiency of hydraulic fracturing for deep volcanic reservoir, based on theoretical and experimental method, the mechanism of fracturing fluid leak-off is deeply studied. We propose a dualistic proppant scheme and employ the fluid loss reducer to control the fluid leak-off in macro-fractures and micro-fractures respectively. The proposed technique remarkably improved the success rate in deep volcanic rock fracturing. It bears important theoretical value and practical significance to improve the hydraulic fracturing design for deep volcanic reservoir.

  12. A Thermoelastic Hydraulic Fracture Design Tool for Geothermal Reservoir Development

    Energy Technology Data Exchange (ETDEWEB)

    Ahmad Ghassemi

    2003-06-30

    Geothermal energy is recovered by circulating water through heat exchange areas within a hot rock mass. Geothermal reservoir rock masses generally consist of igneous and metamorphic rocks that have low matrix permeability. Therefore, cracks and fractures play a significant role in extraction of geothermal energy by providing the major pathways for fluid flow and heat exchange. Thus, knowledge of conditions leading to formation of fractures and fracture networks is of paramount importance. Furthermore, in the absence of natural fractures or adequate connectivity, artificial fracture are created in the reservoir using hydraulic fracturing. At times, the practice aims to create a number of parallel fractures connecting a pair of wells. Multiple fractures are preferred because of the large size necessary when using only a single fracture. Although the basic idea is rather simple, hydraulic fracturing is a complex process involving interactions of high pressure fluid injections with a stressed hot rock mass, mechanical interaction of induced fractures with existing natural fractures, and the spatial and temporal variations of in-situ stress. As a result it is necessary to develop tools that can be used to study these interactions as an integral part of a comprehensive approach to geothermal reservoir development, particularly enhanced geothermal systems. In response to this need we have set out to develop advanced thermo-mechanical models for design of artificial fractures and rock fracture research in geothermal reservoirs. These models consider the significant hydraulic and thermo-mechanical processes and their interaction with the in-situ stress state. Wellbore failure and fracture initiation is studied using a model that fully couples poro-mechanical and thermo-mechanical effects. The fracture propagation model is based on a complex variable and regular displacement discontinuity formulations. In the complex variable approach the displacement discontinuities are

  13. Influence of the preparation design and artificial aging on the fracture resistance of monolithic zirconia crowns.

    Science.gov (United States)

    Mitov, Gergo; Anastassova-Yoshida, Yana; Nothdurft, Frank Phillip; von See, Constantin; Pospiech, Peter

    2016-02-01

    The aim of this study was to evaluate the fracture resistance and fracture behavior of monolithic zirconia crowns in accordance with the preparation design and aging simulation method. An upper first molar was prepared sequentially with three different preparation designs: shoulderless preparation, 0.4 mm chamfer and 0.8 mm chamfer preparation. For each preparation design, 30 monolithic zirconia crowns were fabricated. After cementation on Cr-Co alloy dies, the following artificial aging procedures were performed: (1) thermal cycling and mechanical loading (TCML): 5000 cycles of thermal cycling 5℃-55℃ and chewing simulation (1,200,000 cycles, 50 N); (2) Low Temperature Degradation simulation (LTD): autoclave treatment at 137℃, 2 bar for 3 hours and chewing simulation; and (3) no pre-treatment (control group). After artificial aging, the crowns were loaded until fracture. The mean values of fracture resistance varied between 3414 N (LTD; 0.8 mm chamfer preparation) and 5712 N (control group; shoulderless preparation). Two-way ANOVA analysis showed a significantly higher fracture loads for the shoulderless preparation, whereas no difference was found between the chamfer preparations. In contrast to TCML, after LTD simulation the fracture strength of monolithic zirconia crowns decreased significantly. The monolithic crowns tested in this study showed generally high fracture load values. Preparation design and LTD simulation had a significant influence on the fracture strength of monolithic zirconia crowns.

  14. Monitoring Hydraulic Fracturing Using Ground-Based Controlled Source Electromagnetics

    Science.gov (United States)

    Hickey, M. S.; Trevino, S., III; Everett, M. E.

    2017-12-01

    Hydraulic fracturing allows hydrocarbon production in low permeability formations. Imaging the distribution of fluid used to create a hydraulic fracture can aid in the characterization of fracture properties such as extent of plume penetration as well as fracture azimuth and symmetry. This could contribute to improving the efficiency of an operation, for example, in helping to determine ideal well spacing or the need to refracture a zone. A ground-based controlled-source electromagnetics (CSEM) technique is ideal for imaging the fluid due to the change in field caused by the difference in the conductive properties of the fluid when compared to the background. With advances in high signal to noise recording equipment, coupled with a high-power, broadband transmitter we can show hydraulic fracture extent and azimuth with minimal processing. A 3D finite element code is used to model the complete well casing along with the layered subsurface. This forward model is used to optimize the survey design and isolate the band of frequencies with the best response. In the field, the results of the modeling are also used to create a custom pseudorandom numeric (PRN) code to control the frequencies transmitted through a grounded dipole source. The receivers record the surface voltage across two grounded dipoles, one parallel and one perpendicular to the transmitter. The data are presented as the displays of amplitude ratios across several frequencies with the associated spatial information. In this presentation, we show multiple field results in multiple basins in the United States along with the CSEM theory used to create the survey designs.

  15. Fracture fixation in the operative management of hip fractures (FAITH): an international, multicentre, randomised controlled trial

    OpenAIRE

    Nauth, A. (Aaron); Creek, A.T. (Aaron T.); Zellar, A. (Abby); Lawendy, A.-R. (Abdel-Rahman); Dowrick, A. (Adam); Gupta, A. (Ajay); Dadi, A. (Akhil); Kampen, A.; Yee, A. (Albert); Vries, Alexander; de Mol van Otterloo, A. (Alexander); Garibaldi, A. (Alisha); Liew, A. (Allen); McIntyre, A.W. (Allison W.); Prasad, A.S. (Amal Shankar)

    2017-01-01

    textabstractBackground Reoperation rates are high after surgery for hip fractures. We investigated the effect of a sliding hip screw versus cancellous screws on the risk of reoperation and other key outcomes. Methods For this international, multicentre, allocation concealed randomised controlled trial, we enrolled patients aged 50 years or older with a low-energy hip fracture requiring fracture fixation from 81 clinical centres in eight countries. Patients were assigned by minimisation with a...

  16. Estimation of the controlling stress in creep fracture

    International Nuclear Information System (INIS)

    Henderson, J.; Ferguson, F.R.

    1975-01-01

    The implementation of correct criterion in creep design, has been shown to be of fundamental significance in the assessment of component life. The present report considers the problem of the means whereby the criterion may be derived for a particular metal without the availability of sophisticated complex-stress testing equipment and procedures such as the combined tension and torsion tests on thin walled tubular specimens employed in the earlier fundamental researches on the subject. By investigating a wide spectrum of engineering metals it was established that for homogeneous stress conditions two criteria appeared to be sufficient to cover all the metals studied for complex-stress creep fracture, either the maximum principal stress or the octahedral shear stress criterion. Further, it was found that those metals which developed random and continuous cracking during creep were controlled with respect to fracture time by the maximum principal stress, while metals which showed virtually no cracking were governed by the octahedral shear stress or second order invariant. The physical nature of the final fracture (transcrystalline or inter-crystalline), contrary to considerable current concepts, was found to be unrelated to which criterion was operative. Having reduced the possible fracture criteria to two, it only remained to develop a simple test method exploiting this finding to achieve the precise identification for a particular metal. Seven metals including aluminium, copper, titanium, cast iron and three steels have been investigated in the present report at temperatures where creep conditions are operative. The results have shown that the method leads to sufficiently accurate prediction of the complex stress creep fracture criterion for the metals studied

  17. Effects of simplifying fracture network representation on inert chemical migration in fracture-controlled aquifers

    Science.gov (United States)

    Wellman, Tristan; Shapiro, Allen M.; Hill, Mary C.

    2009-01-01

    While it is widely recognized that highly permeable 'large-scale' fractures dominate chemical migration in many fractured aquifers, recent studies suggest that the pervasive 'small-scale' fracturing once considered of less significance can be equally important for characterizing the spatial extent and residence time associated with transport processes. A detailed examination of chemical migration through fracture-controlled aquifers is used to advance this conceptual understanding. The influence of fracture structure is evaluated by quantifying the effects to transport caused by a systematic removal of fractures from three-dimensional discrete fracture models whose attributes are derived from geologic and hydrologic conditions at multiple field sites. Results indicate that the effects to transport caused by network simplification are sensitive to the fracture network characteristics, degree of network simplification, and plume travel distance, but primarily in an indirect sense since correlation to individual attributes is limited. Transport processes can be 'enhanced' or 'restricted' from network simplification meaning that the elimination of fractures may increase or decrease mass migration, mean travel time, dispersion, and tailing of the concentration plume. The results demonstrate why, for instance, chemical migration may not follow the classic advection-dispersion equation where dispersion approximates the effect of the ignored geologic structure as a strictly additive process to the mean flow. The analyses further reveal that the prediction error caused by fracture network simplification is reduced by at least 50% using the median estimate from an ensemble of simplified fracture network models, and that the error from network simplification is at least 70% less than the stochastic variability from multiple realizations. Copyright 2009 by the American Geophysical Union.

  18. Impact of Oxidative Dissolution on Black Shale Fracturing: Implication for Shale Fracturing Treatment Design

    Science.gov (United States)

    You, L.; Chen, Q.; Kang, Y.; Cheng, Q.; Sheng, J.

    2017-12-01

    Black shales contain a large amount of environment-sensitive compositions, e.g., clay minerals, carbonate, siderite, pyrite, and organic matter. There have been numerous studies on the black shales compositional and pore structure changes caused by oxic environments. However, most of the studies did not focus on their ability to facilitate shale fracturing. To test the redox-sensitive aspects of shale fracturing and its potentially favorable effects on hydraulic fracturing in shale gas reservoirs, the induced microfractures of Longmaxi black shales exposed to deionized water, hydrochloric acid, and hydrogen peroxide at room-temperature for 240 hours were imaged by scanning electron microscopy (SEM) and CT-scanning in this paper. Mineral composition, acoustic emission, swelling, and zeta potential of the untreated and oxidative treatment shale samples were also recorded to decipher the coupled physical and chemical effects of oxidizing environments on shale fracturing processes. Results show that pervasive microfractures (Fig.1) with apertures ranging from tens of nanometers to tens of microns formed in response to oxidative dissolution by hydrogen peroxide, whereas no new microfracture was observed after the exposure to deionized water and hydrochloric acid. The trajectory of these oxidation-induced microfractures was controlled by the distribution of phyllosilicate framework and flaky or stringy organic matter in shale. The experiments reported in this paper indicate that black shales present the least resistance to crack initiation and subcritical slow propagation in hydrogen peroxide, a process we refer to as oxidation-sensitive fracturing, which are closely related to the expansive stress of clay minerals, dissolution of redox-sensitive compositions, destruction of phyllosilicate framework, and the much lower zeta potential of hydrogen peroxide solution-shale system. It could mean that the injection of fracturing water with strong oxidizing aqueous solution may

  19. Sedimentary facies control on mechanical and fracture stratigraphy in turbidites

    NARCIS (Netherlands)

    Ogata, Kei; Storti, Fabrizio; Balsamo, Fabrizio; Tinterri, Roberto; Bedogni, Enrico; Fetter, Marcos; Gomes, Leonardo; Hatushika, Raphael

    2017-01-01

    Natural fracture networks exert a first-order control on the exploitation of resources such as aquifers, hydrocarbons, and geothermal reservoirs, and on environmental issues like underground gas storage and waste disposal. Fractures and the mechanical stratigraphy of layered sequences have been

  20. Control system design guide

    Energy Technology Data Exchange (ETDEWEB)

    Sellers, David; Friedman, Hannah; Haasl, Tudi; Bourassa, Norman; Piette, Mary Ann

    2003-05-01

    The ''Control System Design Guide'' (Design Guide) provides methods and recommendations for the control system design process and control point selection and installation. Control systems are often the most problematic system in a building. A good design process that takes into account maintenance, operation, and commissioning can lead to a smoothly operating and efficient building. To this end, the Design Guide provides a toolbox of templates for improving control system design and specification. HVAC designers are the primary audience for the Design Guide. The control design process it presents will help produce well-designed control systems that achieve efficient and robust operation. The spreadsheet examples for control valve schedules, damper schedules, and points lists can streamline the use of the control system design concepts set forth in the Design Guide by providing convenient starting points from which designers can build. Although each reader brings their own unique questions to the text, the Design Guide contains information that designers, commissioning providers, operators, and owners will find useful.

  1. Fracture Mechanics

    International Nuclear Information System (INIS)

    Jang, Dong Il; Jeong, Gyeong Seop; Han, Min Gu

    1992-08-01

    This book introduces basic theory and analytical solution of fracture mechanics, linear fracture mechanics, non-linear fracture mechanics, dynamic fracture mechanics, environmental fracture and fatigue fracture, application on design fracture mechanics, application on analysis of structural safety, engineering approach method on fracture mechanics, stochastic fracture mechanics, numerical analysis code and fracture toughness test and fracture toughness data. It gives descriptions of fracture mechanics to theory and analysis from application of engineering.

  2. Nutritional risk assessment for Hip fracture, A Case control study

    OpenAIRE

    Torbergsen, Anne Cathrine

    2016-01-01

    The study was conducted at Oslo University Hospital, Norway. Patients were included from September 2009 until April 2011. In total 116 patients and 73 healthy non-fractured controls participated. The study has 3 parts. In the first part, we studied micronutrients and the risk of hip fracture in a case control study. In the second part, we conducted a randomized controlled nutrition intervention trial and finally, in the third part, we studied if micronutrients were associated with delirium in...

  3. Change in fracture risk and fracture pattern after bariatric surgery: nested case-control study.

    Science.gov (United States)

    Rousseau, Catherine; Jean, Sonia; Gamache, Philippe; Lebel, Stéfane; Mac-Way, Fabrice; Biertho, Laurent; Michou, Laëtitia; Gagnon, Claudia

    2016-07-27

     To investigate whether bariatric surgery increases the risk of fracture.  Retrospective nested case-control study.  Patients who underwent bariatric surgery in the province of Quebec, Canada, between 2001 and 2014, selected using healthcare administrative databases.  12 676 patients who underwent bariatric surgery, age and sex matched with 38 028 obese and 126 760 non-obese controls.  Incidence and sites of fracture in patients who had undergone bariatric surgery compared with obese and non-obese controls. Fracture risk was also compared before and after surgery (index date) within each group and by type of surgery from 2006 to 2014. Multivariate conditional Poisson regression models were adjusted for fracture history, number of comorbidities, sociomaterial deprivation, and area of residence.  Before surgery, patients undergoing bariatric surgery (9169 (72.3%) women; mean age 42 (SD 11) years) were more likely to fracture (1326; 10.5%) than were obese (3065; 8.1%) or non-obese (8329; 6.6%) controls. A mean of 4.4 years after surgery, bariatric patients were more susceptible to fracture (514; 4.1%) than were obese (1013; 2.7%) and non-obese (3008; 2.4%) controls. Postoperative adjusted fracture risk was higher in the bariatric group than in the obese (relative risk 1.38, 95% confidence interval 1.23 to 1.55) and non-obese (1.44, 1.29 to 1.59) groups. Before surgery, the risk of distal lower limb fracture was higher, upper limb fracture risk was lower, and risk of clinical spine, hip, femur, or pelvic fractures was similar in the bariatric and obese groups compared with the non-obese group. After surgery, risk of distal lower limb fracture decreased (relative risk 0.66, 0.56 to 0.78), whereas risk of upper limb (1.64, 1.40 to 1.93), clinical spine (1.78, 1.08 to 2.93), pelvic, hip, or femur (2.52, 1.78 to 3.59) fractures increased. The increase in risk of fracture reached significance only for biliopancreatic diversion.  Patients undergoing bariatric

  4. Mechanical design optimization of bioabsorbable fixation devices for bone fractures.

    Science.gov (United States)

    Lovald, Scott T; Khraishi, Tariq; Wagner, Jon; Baack, Bret

    2009-03-01

    Bioabsorbable bone plates can eliminate the necessity for a permanent implant when used to fixate fractures of the human mandible. They are currently not in widespread use because of the low strength of the materials and the requisite large volume of the resulting bone plate. The aim of the current study was to discover a minimally invasive bioabsorbable bone plate design that can provide the same mechanical stability as a standard titanium bone plate. A finite element model of a mandible with a fracture in the body region is subjected to bite loads that are common to patients postsurgery. The model is used first to determine benchmark stress and strain values for a titanium plate. These values are then set as the limits within which the bioabsorbable bone plate must comply. The model is then modified to consider a bone plate made of the polymer poly-L/DL-lactide 70/30. An optimization routine is run to determine the smallest volume of bioabsorbable bone plate that can perform and a titanium bone plate when fixating fractures of this considered type. Two design parameters are varied for the bone plate design during the optimization analysis. The analysis determined that a strut style poly-L-lactide-co-DL-lactide plate of 690 mm2 can provide as much mechanical stability as a similar titanium design structure of 172 mm2. The model has determined a bioabsorbable bone plate design that is as strong as a titanium plate when fixating fractures of the load-bearing mandible. This is an intriguing outcome, considering that the polymer material has only 6% of the stiffness of titanium.

  5. Optimizing fracture and completion design in the Westerose field

    Energy Technology Data Exchange (ETDEWEB)

    Dunn-Norman, S. [Missouri Univ., Rolla, MO (United States); Griffiths, E.; Barnhart, W. [Pan-Canadian Petroleum Ltd., Calgary, AB (Canada); Aunger, D.; Kenny, L.; Halvaci, M.

    1998-12-31

    An experimental study was conducted to determine the feasibility of developing additional gas reserves in the tight sands located between the main bar trends in the Westerose gas field, located 75 km south of Edmonton, Alberta. As part of the study, fracturing and completion alternatives in the Glauconitic `bar` and `interbar` sands were analyzed and compared. Optimal fracture designs for vertical wells were determined for each type of sand. Vertical well performance was compared to stimulated and unstimulated horizontal wells drilled either parallel or perpendicular to the minimum in-situ stress. Results indicated that in-situ permeabilities in the interbar sands were lower than anticipated. It was also shown that over the permeability ranges studied, predicted rates matched actual rates for both vertical fractured and multifractured horizontal wells, suggesting that analytical models can be used to assess anticipated well performance. A further conclusion drawn from the study was that by stimulating a wide variety of permeability ranges, well orientations, anisotropy, fracture orientations and completion options can be determined. 12 refs., 7 tabs., 4 figs.

  6. Using Chemicals to Optimize Conformance Control in Fractured Reservoirs; TOPICAL

    International Nuclear Information System (INIS)

    Seright, Randall S.; Liang, Jenn-Tai; Schrader, Richard; Hagstrom II, John; Wang, Ying; Kumar, Ananad; Wavrik, Kathryn

    2001-01-01

    This report describes work performed during the third and final year of the project, Using Chemicals to Optimize Conformance Control in Fractured Reservoirs. This research project had three objectives. The first objective was to develop a capability to predict and optimize the ability of gels to reduce permeability to water more than that to oil or gas. The second objective was to develop procedures for optimizing blocking agent placement in wells where hydraulic fractures cause channeling problems. The third objective was to develop procedures to optimize blocking agent placement in naturally fractured reservoirs

  7. Fracture Resistance of Zirconia Restorations with a Modified Framework Design

    Directory of Open Access Journals (Sweden)

    sakineh Nikzadjamnani

    2017-12-01

    Full Text Available Objectives: Chipping is one of the concerns related to zirconia crowns. The reasons of chipping have not been completely understood. This in-vitro study aimed to assess the effect of coping design on the fracture resistance of all-ceramic single crowns with zirconia frameworks. Materials and Methods: Two types of zirconia copings were designed (n=12: (1 a standard coping (SC with a 0.5mm uniform thickness and (2 a modified coping (MC consisted of a lingual margin of 1mm thickness and 2mm height connected to a proximal strut of 4mm height and a 0.3mm-wide facial collar. After veneer porcelain firing, the crowns were cemented to metal dies. Afterwards, a static vertical load was applied until failure. The modes of failure were determined. Data were calculated and statistically analyzed by independent samples T-test. P<0.05 was considered statistically significant.Results: The mean and standard deviation (SD of the final fracture resistance equaled to 3519.42±1154.96 N and 3570.01±1224.33 N in SC and MC groups, respectively; the difference was not statistically significant (P=0.9. Also, the mean and SD of the initial fracture resistance equaled to 3345.34±1190.93 N and 3471.52±1228.93 N in SC and MC groups, respectively (P=0.8. Most of the specimens in both groups showed the mixed failure mode. Conclusions: Based on the results, the modified core design may not significantly improve the fracture resistance.

  8. Control room design

    International Nuclear Information System (INIS)

    Zinke, H.

    1980-01-01

    To control a 1300 megawatt nuclear power plant, about 15000 plant parameters must be collected together to control and operate the plant. The control room design therefore is of particular importance. The main design criteria are: Required functions of the power plant process - Level of Automation - Ergonomics - Available Technology. Extensive analysis has resulted in a control room design method. This ensures that an objective solution will be reached. Resulting from this methodical approach are: 1. Scope, position and appearance of the instrumentation. 2. Scope, position and appearance of the operator controls. Process analysis dictates what instrumentation and operator controls are needed. The priority and importance of the control and instrumentation (this we define as the utilisation areas), dictates the rough layout of the control room. (orig./RW)

  9. Applied Control Systems Design

    CERN Document Server

    Mahmoud, Magdi S

    2012-01-01

    Applied Control System Design examines several methods for building up systems models based on real experimental data from typical industrial processes and incorporating system identification techniques. The text takes a comparative approach to the models derived in this way judging their suitability for use in different systems and under different operational circumstances. A broad spectrum of control methods including various forms of filtering, feedback and feedforward control is applied to the models and the guidelines derived from the closed-loop responses are then composed into a concrete self-tested recipe to serve as a check-list for industrial engineers or control designers. System identification and control design are given equal weight in model derivation and testing to reflect their equality of importance in the proper design and optimization of high-performance control systems. Readers’ assimilation of the material discussed is assisted by the provision of problems and examples. Most of these e...

  10. Guidelines for safe design of shipping packages against brittle fracture

    International Nuclear Information System (INIS)

    1993-08-01

    In 1992, the ninth meeting of the Standing Advisory Group on the Safe Transport of Radioactive Materials recommended the publication of this TECDOC in an effort to promote the widest debate on the criteria for the brittle fracture safe design of transport packages. The published IAEA advice on the influence of brittle fracture on material integrity is contained in Appendix IX of the Advisory Material for the IAEA Regulations for the Safety Transport of Radioactive Material (1985 Edition, as amended 1990), Safety Series No. 37. This guidance is limited in scope, dealing only with ferritic steels in general terms. It is becoming more common for designers to specify materials other than austenitic stainless steel for packaging components. The data on ferritic steels cannot be assumed to apply to other metals, hence the need for further guidance on the development of relationships describing material properties at low temperatures. The methods described in this TECDOC will be considered by the Revision Panel for inclusion in the 1996 Edition of the IAEA Regulations for the Safe Transport of Radioactive Material and the supporting documents. If accepted by the Revision Panel, this advice will be a candidate for upgrading to a Safety Practice. In the interim period, this TECDOC offers provisional advice on brittle fracture evaluation. It is acknowledged that, at this stage, the views expressed do not necessarily reflect those of the governments of Member States or organizations under whose auspices this manuscript was produced. Refs and figs

  11. Sensory impairments and wrist fractures: A case-control study

    Directory of Open Access Journals (Sweden)

    Bergthora Baldursdottir

    2017-12-01

    Full Text Available Objectives: To investigate vestibular function, foot sensation, postural control and functional abilities, and to evaluate whether these variables are associated with fall-related wrist fracture. Methods: A case-control study was conducted with 98 subjects, age range 50–75 years, who had sustained a fall-related wrist fracture. Forty-eight sex-, age- and physical activity-matched individuals, with no previous history of wrist fracture, served as controls. Measurements included: head-shake test (HST, tuning fork, biothesiometer, Semmes-Weinstein monofilaments (MF, Sensory Organization Test (SOT, Five-Times-Sit-to-Stand Test (FTSTS, 10-m walk test (10MWT, Activities-specific Balance Confidence (ABC, and the Dizziness Handicap Inventory (DHI scales. Logistic regression models were used to determine associations of variables with a fall-related wrist fracture. Results: Vestibular asymmetry was apparent in 82% of wrist fracture subjects and 63% of controls (p = 0.012. Plantar pressure sensation (p <0.001, SOT composite scores (p < 0.001, 10MWT (p <0.001, FTSTS (p <0.001, ABC (p <0.001 and DHI (p <0.005 were significantly poorer among cases than controls. A positive HST (odds ratio (OR 5.424; p = 0.008 and monofilament sensation (OR 3.886; p = 0.014 showed the strongest associations with having a fall-related wrist fracture. Conclusion: Asymmetrical vestibular function and reduced plantar pressure sensation are associated with fall-related wrist fractures among the ageing population. These factors are potential targets for future interventions.

  12. Robot-Assisted Fracture Surgery: Surgical Requirements and System Design.

    Science.gov (United States)

    Georgilas, Ioannis; Dagnino, Giulio; Tarassoli, Payam; Atkins, Roger; Dogramadzi, Sanja

    2018-03-09

    The design of medical devices is a complex and crucial process to ensure patient safety. It has been shown that improperly designed devices lead to errors and associated accidents and costs. A key element for a successful design is incorporating the views of the primary and secondary stakeholders early in the development process. They provide insights into current practice and point out specific issues with the current processes and equipment in use. This work presents how information from a user-study conducted in the early stages of the RAFS (Robot Assisted Fracture Surgery) project informed the subsequent development and testing of the system. The user needs were captured using qualitative methods and converted to operational, functional, and non-functional requirements based on the methods derived from product design and development. This work presents how the requirements inform a new workflow for intra-articular joint fracture reduction using a robotic system. It is also shown how the various elements of the system are developed to explicitly address one or more of the requirements identified, and how intermediate verification tests are conducted to ensure conformity. Finally, a validation test in the form of a cadaveric trial confirms the ability of the designed system to satisfy the aims set by the original research question and the needs of the users.

  13. Fracture fixation in the operative management of hip fractures (FAITH) : an international, multicentre, randomised controlled trial

    NARCIS (Netherlands)

    Nauth, Aaron; Creek, Aaron T.; Zellar, Abby; Lawendy, Abdel Rahman; Dowrick, Adam; Gupta, Ajay; Dadi, Akhil; van Kampen, Albert; Yee, Albert; de Vries, Alexander C.; de Mol van Otterloo, Alexander; Garibaldi, Alisha; Liew, Allen; McIntyre, Allison W.; Prasad, Amal Shankar; Romero, Amanda W.; Rangan, Amar; Oatt, Amber; Sanghavi, Amir; Foley, Amy L.; Karlsten, Anders; Dolenc, Andrea; Bucknill, Andrew; Chia, Andrew; Evans, Andrew; Gong, Andrew; Schmidt, Andrew H.; Marcantonio, Andrew J.; Jennings, Andrew; Ward, Angela; Khanna, Angshuman; Rai, Anil; Smits, Anke B; Horan, Annamarie D.; Brekke, Anne Christine; Flynn, Annette; Duraikannan, Aravin; Stødle, Are; van Vugt, Arie B.; Luther, Arlene; Zurcher, Arthur W.; Jain, Arvind; Amundsen, Asgeir; Moaveni, Ash; Carr, Ashley; Sharma, Ateet; Hill, Austin D.; Trommer, Axel; Rai, B. Sachidananda; Hileman, Barbara; Schreurs, Bart; Verhoeven, Bart A N; Barden, Benjamin B.; Flatøy, Bernhard; Cleffken, Berry I.; Bøe, Berthe; Perey, Bertrand; Hanusch, Birgit C.; Weening, Brad; Fioole, Bram; Rijbroek, Bram; Crist, Brett D.; Halliday, Brett; Peterson, Brett; Mullis, Brian; Richardson, C. Glen; Clark, Callum; Sagebien, Carlos A.; van der Pol, Carmen C.; Bowler, Carol; Humphrey, Catherine A.; Coady, Catherine; Koppert, Cees L.; Coles, Chad; Tannoury, Chadi; DePaolo, Charles J.; Gayton, Chris; Herriott, Chris; Reeves, Christina; Tieszer, Christina; Dobb, Christine; Anderson, Christopher G.; Sage, Claire; Cuento, Claudine; Jones, Clifford B.; Bosman, Coks H.R.; Linehan, Colleen; van der Hart, Cor P.; Henderson, Corey; Lewis, Courtland G.; Davis, Craig A.; Donohue, Craig; Mauffrey, Cyril; Sundaresh, D. C.; Farrell, Dana J.; Whelan, Daniel B.; Horwitz, Daniel; Stinner, Daniel; Viskontas, Darius; Roffey, Darren M.; Alexander, David; Karges, David E.; Hak, David; Johnston, David; Love, David; Wright, David M.; Zamorano, David P.; Goetz, David R.; Sanders, David; Stephen, David; Yen, David; Bardana, Davide; Olakkengil, Davy J.; Lawson, Deanna; Maddock, Deborah; Sietsema, Debra L.; Pourmand, Deeba; Den Hartog, Dennis; Donegan, Derek; Heels-Ansdell, Diane; Nam, Diane; Inman, Dominic; Boyer, Dory; Li, Doug; Gibula, Douglas; Price, Dustin M.; Watson, Dylan J.; Hammerberg, E. Mark; Tan, Edward C T H; de Graaf, Eelco J.R.; Vesterhus, Elise Berg; Roper, Elizabeth; Edwards, Elton; Schemitsch, Emil H.; Hammacher, Eric R.; Henderson, Eric R.; Whatley, Erica; Torres, Erick T.; Vermeulen, Erik G.J.; Finn, Erin; Van Lieshout, Esther M M; Wai, Eugene K.; Bannister, Evan R.; Kile, Evelyn; Theunissen, Evert B.M.; Ritchie, Ewan D.; Khan, Farah; Moola, Farhad; Howells, Fiona; de Nies, Frank; van der Heijden, Frank H.W.M.; de Meulemeester, Frank R.A.J.; Frihagen, Frede; Nilsen, Fredrik; Schmidt, G. Ben; Albers, G. H.Robert; Gudger, Garland K.; Johnson, Garth; Gruen, Gary; Zohman, Gary; Sharma, Gaurav; Wood, Gavin; Tetteroo, Geert W.M.; Hjorthaug, Geir; Jomaas, Geir; Donald, Geoff; Rieser, Geoffrey Ryan; Reardon, Gerald; Slobogean, Gerard P.; Roukema, Gert R.; Visser, Gijs A.; Moatshe, Gilbert; Horner, Gillian; Rose, Glynis; Guyatt, Gordon; Chuter, Graham; Etherington, Greg; Rocca, Gregory J.Della; Ekås, Guri; Dobbin, Gwendolyn; Lemke, H. Michael; Curry, Hamish; Boxma, Han; Gissel, Hannah; Kreder, Hans; Kuiken, Hans; Brom, Hans L.F.; Pape, Hans Christoph; van der Vis, Harm M.; Bedi, Harvinder; Vallier, Heather A.; Brien, Heather; Silva, Heather; Newman, Heike; Viveiros, Helena; van der Hoeven, Henk; Ahn, Henry; Johal, Herman; Rijna, Herman; Stockmann, Heyn; Josaputra, Hong A.; Carlisle, Hope; van der Brand, Igor; Dawson, Imro; Tarkin, Ivan; Wong, Ivan; Parr, J. Andrew; Trenholm, J. Andrew; Goslings, J Carel; Amirault, J. David; Broderick, J. Scott; Snellen, Jaap P.; Zijl, Jacco A.C.; Ahn, Jaimo; Ficke, James; Irrgang, James; Powell, James; Ringler, James R.; Shaer, James; Monica, James T.; Biert, Jan; Bosma, Jan; Brattgjerd, Jan Egil; Frölke, Jan Paul M.; Wille, Jan; Rajakumar, Janakiraman; Walker, Jane E.; Baker, Janell K.; Ertl, Janos P.; De Vries, Jean-Paul P. M.; Gardeniers, Jean W.M.; May, Jedediah; Yach, Jeff; Hidy, Jennifer T.; Westberg, Jerald R.; Hall, Jeremy A.; van Mulken, Jeroen; McBeth, Jessica Cooper; Hoogendoorn, Jochem M; Hoffman, Jodi M.; Cherian, Joe Joseph; Tanksley, John A.; Clarke-Jenssen, John; Adams, John D.; Esterhai, John; Tilzey, John F.; Murnaghan, John; Ketz, John P.; Garfi, John S.; Schwappach, John; Gorczyca, John T.; Wyrick, John; Rydinge, Jonas; Foret, Jonathan L.; Gross, Jonathan M.; Keeve, Jonathan P.; Meijer, Joost; Scheepers, Joris J.G.; Baele, Joseph; O'Neil, Joseph; Cass, Joseph R.; Hsu, Joseph R.; Dumais, Jules; Lee, Julia; Switzer, Julie A.; Agel, Julie; Richards, Justin E.; Langan, Justin W.; Turckan, Kahn; Pecorella, Kaili; Rai, Kamal; Aurang, Kamran; Shively, Karl; van Wessem, Karlijn; Moon, Karyn; Eke, Kate; Erwin, Katie; Milner, Katrine; Ponsen, Kees Jan; Mills, Kelli; Apostle, Kelly; Johnston, Kelly; Trask, Kelly; Strohecker, Kent; Stringfellow, Kenya; Kruse, Kevin K.; Tetsworth, Kevin; Mitchell, Khalis; Browner, Kieran; Hemlock, Kim; Carcary, Kimberly; Jørgen Haug, Knut; Noble, Krista; Robbins, Kristin; Payton, Krystal; Jeray, Kyle J.; Rubino, L. Joseph; Nastoff, Lauren A.; Leffler, Lauren C.; Stassen, Laurents P.S.; O'Malley, Lawrence K.; Specht, Lawrence M.; Thabane, Lehana; Geeraedts, Leo M.G.; Shell, Leslie E.; Anderson, Linda K.; Eickhoff, Linda S.; Lyle, Lindsey; Pilling, Lindsey; Buckingham, Lisa; Cannada, Lisa K.; Wild, Lisa M.; Dulaney-Cripe, Liz; Poelhekke, Lodewijk M.S.J.; Govaert, Lonneke; Ton, Lu; Kottam, Lucksy; Leenen, Luke P.H.; Clipper, Lydia; Jackson, Lyle T.; Hampton, Lynne; de Waal Malefijt, Maarten C.; Simons, Maarten P.; van der Elst, Maarten; Bronkhorst, Maarten W.G.A.; Bhatia, Mahesh; Swiontkowski, Marc; Lobo, Margaret J.; Swinton, Marilyn; Pirpiris, Marinis; Molund, Marius; Gichuru, Mark; Glazebrook, Mark; Harrison, Mark; Jenkins, Mark; MacLeod, Mark; de Vries, Mark R.; Butler, Mark S.; Nousiainen, Markku; van ‘t Riet, Martijne; Tynan, Martin C.; Campo, Martin; Eversdijk, Martin G.; Heetveld, Martin J.; Richardson, Martin; Breslin, Mary; Fan, Mary; Edison, Matt; Napierala, Matthew; Knobe, Matthias; Russ, Matthias; Zomar, Mauri; de Brauw, Maurits; Esser, Max; Hurley, Meghan; Peters, Melissa E.; Lorenzo, Melissa; Li, Mengnai; Archdeacon, Michael; Biddulph, Michael; Charlton, Michael R; McDonald, Michael D.; McKee, Michael D.; Dunbar, Michael; Torchia, Michael E.; Gross, Michael; Hewitt, Michael; Holt, Michael; Prayson, Michael J.; Edwards, Michael J R; Beckish, Michael L.; Brennan, Michael L.; Dohm, Michael P.; Kain, Michael S.H.; Vogt, Michelle; Yu, Michelle; Verhofstad, Michiel H J; Segers, Michiel J M; Segers, Michiel J M; Siroen, Michiel P.C.; Reed, Mike; Vicente, Milena R.; Bruijninckx, Milko M.M.; Trivedi, Mittal; Bhandari, Mohit; Moore, Molly M.; Kunz, Monica; Smedsrud, Morten; Palla, Naveen; Jain, Neeraj; Out, Nico J.M.; Simunovic, Nicole; Simunovic, Nicole; Schep, Niels W. L.; Müller, Oliver; Guicherit, Onno R.; Van Waes, Oscar J.F.; Wang, Otis; Doornebosch, Pascal G.; Seuffert, Patricia; Hesketh, Patrick J.; Weinrauch, Patrick; Duffy, Paul; Keller, Paul; Lafferty, Paul M.; Pincus, Paul; Tornetta, Paul; Zalzal, Paul; McKay, Paula; Cole, Peter A.; de Rooij, Peter D.; Hull, Peter; Go, Peter M.N.Y.M.; Patka, Peter; Siska, Peter; Weingarten, Peter; Kregor, Philip; Stahel, Philip; Stull, Philip; Wittich, Philippe; de Rijcke, Piet A.R.; Oprel, Pim; Devereaux, P. J.; Zhou, Qi; Lee Murphy, R.; Alosky, Rachel; Clarkson, Rachel; Moon, Raely; Logishetty, Rajanikanth; Nanda, Rajesh; Sullivan, Raymond J.; Snider, Rebecca G.; Buckley, Richard E.; Iorio, Richard; Farrugia, Richard J.; Jenkinson, Richard; Laughlin, Richard; Groenendijk, Richard P R; Gurich, Richard W.; Worman, Ripley; Silvis, Rob; Haverlag, Robert; Teasdall, Robert J.; Korley, Robert; McCormack, Robert; Probe, Robert; Cantu, Robert V.; Huff, Roger B.; Simmermacher, Rogier K J; Peters, Rolf; Pfeifer, Roman; Liem, Ronald; Wessel, Ronald N.; Verhagen, Ronald; Vuylsteke, Ronald J C L M; Leighton, Ross; McKercher, Ross; Poolman, Rudolf W; Miller, Russell; Bicknell, Ryan; Finnan, Ryan; Khan, Ryan M.; Mehta, Samir; Vang, Sandy; Singh, Sanjay; Anand, Sanjeev; Anderson, Sarah A.; Dawson, Sarah A.; Marston, Scott B.; Porter, Scott E.; Watson, Scott T.; Festen, Sebastiaan; Lieberman, Shane; Puloski, Shannon; Bielby, Shea A.; Sprague, Sheila; Hess, Shelley; MacDonald, Shelley; Evans, Simone; Bzovsky, Sofia; Hasselund, Sondre; Lewis, Sophie; Ugland, Stein; Caminiti, Stephanie; Tanner, Stephanie L.; Zielinski, Stephanie M.; Shepard, Stephanie; Sems, Stephen A.; Walter, Stephen D.; Doig, Stephen; Finley, Stephen H.; Kates, Stephen; Lindenbaum, Stephen; Kingwell, Stephen P.; Csongvay, Steve; Papp, Steve; Buijk, Steven E.; Rhemrev, Steven J.; Hollenbeck, Steven M.; van Gaalen, Steven M.; Yang, Steven; Weinerman, Stuart; Lambert, Sue; Liew, Susan; Meylaerts, Sven A.G.; Blokhuis, Taco J.; de Vries Reilingh, Tammo S.; Lona, Tarjei; Scott, Taryn; Swenson, Teresa K.; Endres, Terrence J.; Axelrod, Terry; van Egmond, Teun; Pace, Thomas B.; Kibsgård, Thomas; Schaller, Thomas M.; Ly, Thuan V.; Miller, Timothy J.; Weber, Timothy; Le, Toan; Oliver, Todd M.; Karsten, Tom M.; Borch, Tor; Hoseth, Tor Magne; Nicolaisen, Tor; Ianssen, Torben; Rutherford, Tori; Nanney, Tracy; Gervais, Trevor; Stone, Trevor; Schrickel, Tyson; Scrabeck, Tyson; Ganguly, Utsav; Naumetz, V.; Frizzell, Valda; Wadey, Veronica; Jones, Vicki; Avram, Victoria; Mishra, Vimlesh; Yadav, Vineet; Arora, Vinod; Tyagi, Vivek; Borsella, Vivian; Willems, W. Jaap; Hoffman, W. H.; Gofton, Wade T.; Lackey, Wesley G.; Ghent, Wesley; Obremskey, William; Oxner, William; Cross, William W.; Murtha, Yvonne M.; Murdoch, Zoe

    2017-01-01

    Background Reoperation rates are high after surgery for hip fractures. We investigated the effect of a sliding hip screw versus cancellous screws on the risk of reoperation and other key outcomes. Methods For this international, multicentre, allocation concealed randomised controlled trial, we

  14. Fracture fixation in the operative management of hip fractures (FAITH): an international, multicentre, randomised controlled trial

    NARCIS (Netherlands)

    Nauth, A. (Aaron); Creek, A.T. (Aaron T.); Zellar, A. (Abby); Lawendy, A.-R. (Abdel-Rahman); Dowrick, A. (Adam); Gupta, A. (Ajay); Dadi, A. (Akhil); A. van Kampen (A.); Yee, A. (Albert); A.C. de Vries (Alexander); de Mol van Otterloo, A. (Alexander); Garibaldi, A. (Alisha); Liew, A. (Allen); McIntyre, A.W. (Allison W.); Prasad, A.S. (Amal Shankar); Romero, A.W. (Amanda W.); Rangan, A. (Amar); Oatt, A. (Amber); Sanghavi, A. (Amir); Foley, A.L. (Amy L.); Karlsten, A. (Anders); Dolenc, A. (Andrea); Bucknill, A. (Andrew); Chia, A. (Andrew); Evans, A. (Andrew); Gong, A. (Andrew); Schmidt, A.H. (Andrew H.); Marcantonio, A.J. (Andrew J.); Jennings, A. (Andrew); Ward, A. (Angela); Khanna, A. (Angshuman); Rai, A. (Anil); Smits, A.B. (Anke B.); Horan, A.D. (Annamarie D.); Brekke, A.C. (Anne Christine); Flynn, A. (Annette); Duraikannan, A. (Aravin); Stødle, A. (Are); van Vugt, A.B. (Arie B.); Luther, A. (Arlene); Zurcher, A.W. (Arthur W.); Jain, A. (Arvind); Amundsen, A. (Asgeir); Moaveni, A. (Ash); Carr, A. (Ashley); Sharma, A. (Ateet); Hill, A.D. (Austin D.); Trommer, A. (Axel); Rai, B.S. (B. Sachidananda); Hileman, B. (Barbara); Schreurs, B. (Bart); Verhoeven, B. (Bart); Barden, B.B. (Benjamin B.); Flatøy, B. (Bernhard); B.I. Cleffken (Berry); Bøe, B. (Berthe); Perey, B. (Bertrand); Hanusch, B.C. (Birgit C.); Weening, B. (Brad); B. Fioole (Bram); Rijbroek, B. (Bram); Crist, B.D. (Brett D.); Halliday, B. (Brett); Peterson, B. (Brett); Mullis, B. (Brian); Richardson, C.G. (C. Glen); Clark, C. (Callum); Sagebien, C.A. (Carlos A.); C. van der Pol (Carmen); Bowler, C. (Carol); Humphrey, C.A. (Catherine A.); Coady, C. (Catherine); Koppert, C.L. (Cees L.); Coles, C. (Chad); Tannoury, C. (Chadi); DePaolo, C.J. (Charles J.); Gayton, C. (Chris); Herriott, C. (Chris); Reeves, C. (Christina); Tieszer, C. (Christina); Dobb, C. (Christine); Anderson, C.G. (Christopher G.); Sage, C. (Claire); Cuento, C. (Claudine); Jones, C.B. (Clifford B.); Bosman, C.H.R. (Coks H.R.); Linehan, C. (Colleen); C.P. van der Hart (Cor P.); Henderson, C. (Corey); Lewis, C.G. (Courtland G.); Davis, C.A. (Craig A.); Donohue, C. (Craig); Mauffrey, C. (Cyril); Sundaresh, D.C. (D. C.); Farrell, D.J. (Dana J.); Whelan, D.B. (Daniel B.); Horwitz, D. (Daniel); Stinner, D. (Daniel); Viskontas, D. (Darius); Roffey, D.M. (Darren M.); Alexander, D. (David); Karges, D.E. (David E.); Hak, D. (David); Johnston, D. (David); Love, D. (David); Wright, D.M. (David M.); Zamorano, D.P. (David P.); Goetz, D.R. (David R.); Sanders, D. (David); Stephen, D. (David); Yen, D. (David); Bardana, D. (Davide); Olakkengil, D.J. (Davy J); Lawson, D. (Deanna); Maddock, D. (Deborah); Sietsema, D.L. (Debra L.); Pourmand, D. (Deeba); D. den Hartog (Dennis); Donegan, D. (Derek); D. Heels-Ansdell (Diane); Nam, D. (Diane); Inman, D. (Dominic); Boyer, D. (Dory); Li, D. (Doug); Gibula, D. (Douglas); Price, D.M. (Dustin M.); Watson, D.J. (Dylan J.); Hammerberg, E.M. (E. Mark); Tan, E.T.C.H. (Edward T.C.H.); E.J.R. de Graaf (Eelco); Vesterhus, E.B. (Elise Berg); Roper, E. (Elizabeth); Edwards, E. (Elton); E.H. Schemitsch (Emil); E.R. Hammacher (Eric); Henderson, E.R. (Eric R.); Whatley, E. (Erica); Torres, E.T. (Erick T.); Vermeulen, E.G.J. (Erik G.J.); Finn, E. (Erin); E.M.M. van Lieshout (Esther); Wai, E.K. (Eugene K.); Bannister, E.R. (Evan R.); Kile, E. (Evelyn); Theunissen, E.B.M. (Evert B.M.); Ritchie, E.D. (Ewan D.); Khan, F. (Farah); Moola, F. (Farhad); Howells, F. (Fiona); F. de Nies (Frank); F.H.W.M. van der Heijden (Frank); de Meulemeester, F.R.A.J. (Frank R.A.J.); F. Frihagen (Frede); Nilsen, F. (Fredrik); Schmidt, G.B. (G. Ben); Albers, G.H.R. (G.H. Robert); Gudger, G.K. (Garland K.); Johnson, G. (Garth); Gruen, G. (Gary); Zohman, G. (Gary); Sharma, G. (Gaurav); Wood, G. (Gavin); G.W.M. Tetteroo (Geert); Hjorthaug, G. (Geir); Jomaas, G. (Geir); Donald, G. (Geoff); Rieser, G.R. (Geoffrey Ryan); Reardon, G. (Gerald); Slobogean, G.P. (Gerard P.); G.R. Roukema (Gert); Visser, G.A. (Gijs A.); Moatshe, G. (Gilbert); Horner, G. (Gillian); Rose, G. (Glynis); Guyatt, G. (Gordon); Chuter, G. (Graham); Etherington, G. (Greg); Rocca, G.J.D. (Gregory J. Della); Ekås, G. (Guri); Dobbin, G. (Gwendolyn); Lemke, H.M. (H. Michael); Curry, H. (Hamish); H. Boxma (Han); Gissel, H. (Hannah); Kreder, H. (Hans); Kuiken, H. (Hans); H.L.F. Brom; Pape, H.-C. (Hans-Christoph); H.M. van der Vis (Harm); Bedi, H. (Harvinder); Vallier, H.A. (Heather A.); Brien, H. (Heather); Silva, H. (Heather); Newman, H. (Heike); H. Viveiros (Helena); van der Hoeven, H. (Henk); Ahn, H. (Henry); Johal, H. (Herman); H. Rijna; Stockmann, H. (Heyn); Josaputra, H.A. (Hong A.); Carlisle, H. (Hope); van der Brand, I. (Igor); I. Dawson (Imro); Tarkin, I. (Ivan); Wong, I. (Ivan); Parr, J.A. (J. Andrew); Trenholm, J.A. (J. Andrew); J.C. Goslings (Carel); Amirault, J.D. (J. David); Broderick, J.S. (J. Scott); Snellen, J.P. (Jaap P.); Zijl, J.A.C. (Jacco A.C.); Ahn, J. (Jaimo); Ficke, J. (James); Irrgang, J. (James); Powell, J. (James); Ringler, J.R. (James R.); Shaer, J. (James); Monica, J.T. (James T.); J. Biert (Jan); Bosma, J. (Jan); Brattgjerd, J.E. (Jan Egil); J.P.M. Frölke (Jan Paul); J.C. Wille (Jan); Rajakumar, J. (Janakiraman); Walker, J.E. (Jane E.); Baker, J.K. (Janell K.); Ertl, J.P. (Janos P.); de Vries, J.P.P.M. (Jean Paul P.M.); Gardeniers, J.W.M. (Jean W.M.); May, J. (Jedediah); Yach, J. (Jeff); Hidy, J.T. (Jennifer T.); Westberg, J.R. (Jerald R.); Hall, J.A. (Jeremy A.); van Mulken, J. (Jeroen); McBeth, J.C. (Jessica Cooper); Hoogendoorn, J. (Jochem); Hoffman, J.M. (Jodi M.); Cherian, J.J. (Joe Joseph); Tanksley, J.A. (John A.); Clarke-Jenssen, J. (John); Adams, J.D. (John D.); Esterhai, J. (John); Tilzey, J.F. (John F.); Murnaghan, J. (John); Ketz, J.P. (John P.); Garfi, J.S. (John S.); Schwappach, J. (John); Gorczyca, J.T. (John T.); Wyrick, J. (John); Rydinge, J. (Jonas); Foret, J.L. (Jonathan L.); Gross, J.M. (Jonathan M.); Keeve, J.P. (Jonathan P.); Meijer, J. (Joost); J.J. Scheepers (Joris J.); Baele, J. (Joseph); O'Neil, J. (Joseph); Cass, J.R. (Joseph R.); Hsu, J.R. (Joseph R.); Dumais, J. (Jules); Lee, J. (Julia); Switzer, J.A. (Julie A.); Agel, J. (Julie); Richards, J.E. (Justin E.); Langan, J.W. (Justin W.); Turckan, K. (Kahn); Pecorella, K. (Kaili); Rai, K. (Kamal); Aurang, K. (Kamran); Shively, K. (Karl); K.J.P. van Wessem; Moon, K. (Karyn); Eke, K. (Kate); Erwin, K. (Katie); Milner, K. (Katrine); K.J. Ponsen (Kees-jan); Mills, K. (Kelli); Apostle, K. (Kelly); Johnston, K. (Kelly); Trask, K. (Kelly); Strohecker, K. (Kent); Stringfellow, K. (Kenya); Kruse, K.K. (Kevin K.); Tetsworth, K. (Kevin); Mitchell, K. (Khalis); Browner, K. (Kieran); Hemlock, K. (Kim); Carcary, K. (Kimberly); Jørgen Haug, K. (Knut); Noble, K. (Krista); Robbins, K. (Kristin); Payton, K. (Krystal); Jeray, K.J. (Kyle J.); Rubino, L.J. (L. Joseph); Nastoff, L.A. (Lauren A.); Leffler, L.C. (Lauren C.); L.P. Stassen (Laurents); O'Malley, L.K. (Lawrence K.); Specht, L.M. (Lawrence M.); L. Thabane (Lehana); Geeraedts, L.M.G. (Leo M.G.); Shell, L.E. (Leslie E.); Anderson, L.K. (Linda K.); Eickhoff, L.S. (Linda S.); Lyle, L. (Lindsey); Pilling, L. (Lindsey); Buckingham, L. (Lisa); Cannada, L.K. (Lisa K.); Wild, L.M. (Lisa M.); Dulaney-Cripe, L. (Liz); L.M.S.J. Poelhekke; Govaert, L. (Lonneke); Ton, L. (Lu); Kottam, L. (Lucksy); L.P.H. Leenen (Luke); Clipper, L. (Lydia); Jackson, L.T. (Lyle T.); Hampton, L. (Lynne); de Waal Malefijt, M.C. (Maarten C.); M.P. Simons; M. van der Elst (Maarten); M.W.G.A. Bronkhorst (Maarten); Bhatia, M. (Mahesh); M.F. Swiontkowski (Marc ); Lobo, M.J. (Margaret J.); Swinton, M. (Marilyn); Pirpiris, M. (Marinis); Molund, M. (Marius); Gichuru, M. (Mark); Glazebrook, M. (Mark); Harrison, M. (Mark); Jenkins, M. (Mark); MacLeod, M. (Mark); M.R. de Vries (Mark); Butler, M.S. (Mark S.); Nousiainen, M. (Markku); van ‘t Riet, M. (Martijne); Tynan, M.C. (Martin C.); Campo, M. (Martin); M.G. Eversdijk (Martin); M.J. Heetveld (Martin); Richardson, M. (Martin); Breslin, M. (Mary); Fan, M. (Mary); Edison, M. (Matt); Napierala, M. (Matthew); Knobe, M. (Matthias); Russ, M. (Matthias); Zomar, M. (Mauri); de Brauw, M. (Maurits); Esser, M. (Max); Hurley, M. (Meghan); Peters, M.E. (Melissa E.); Lorenzo, M. (Melissa); Li, M. (Mengnai); Archdeacon, M. (Michael); Biddulph, M. (Michael); Charlton, M. (Michael); McDonald, M.D. (Michael D.); McKee, M.D. (Michael D.); Dunbar, M. (Michael); Torchia, M.E. (Michael E.); Gross, M. (Michael); Hewitt, M. (Michael); Holt, M. (Michael); Prayson, M.J. (Michael J.); M.J.R. Edwards (Michael); Beckish, M.L. (Michael L.); Brennan, M.L. (Michael L.); Dohm, M.P. (Michael P.); Kain, M.S.H. (Michael S.H.); Vogt, M. (Michelle); Yu, M. (Michelle); M.H.J. Verhofstad (Michiel); Segers, M.J.M. (Michiel J.M.); M.J.M. Segers (Michiel); Siroen, M.P.C. (Michiel P.C.); M.R. Reed (Mike); Vicente, M.R. (Milena R.); M.M.M. Bruijninckx (Milko); Trivedi, M. (Mittal); M. Bhandari (Mohit); Moore, M.M. (Molly M.); Kunz, M. (Monica); Smedsrud, M. (Morten); Palla, N. (Naveen); Jain, N. (Neeraj); Out, N.J.M. (Nico J.M.); Simunovic, N. (Nicole); Simunovic, N. (Nicole); N.W.L. Schep (Niels); Müller, O. (Oliver); Guicherit, O.R. (Onno R.); O.J.F. van Waes (Oscar); Wang, O. (Otis); P. Doornebosch (Pascal); Seuffert, P. (Patricia); Hesketh, P.J. (Patrick J.); Weinrauch, P. (Patrick); Duffy, P. (Paul); Keller, P. (Paul); Lafferty, P.M. (Paul M.); Pincus, P. (Paul); P. Tornetta III (Paul); Zalzal, P. (Paul); McKay, P. (Paula); Cole, P.A. (Peter A.); de Rooij, P.D. (Peter D.); Hull, P. (Peter); Go, P.M.N.Y.M. (Peter M.N.Y.M.); P. Patka (Peter); Siska, P. (Peter); Weingarten, P. (Peter); Kregor, P. (Philip); Stahel, P. (Philip); Stull, P. (Philip); P. Wittich (Philippe); P.A.R. Rijcke (Piet); P.P. Oprel (Pim); Devereaux, P.J. (P. J.); Zhou, Q. (Qi); Lee Murphy, R. (R.); Alosky, R. (Rachel); Clarkson, R. (Rachel); Moon, R. (Raely); Logishetty, R. (Rajanikanth); Nanda, R. (Rajesh); Sullivan, R.J. (Raymond J.); Snider, R.G. (Rebecca G.); Buckley, R.E. (Richard E.); Iorio, R. (Richard); Farrugia, R.J. (Richard J); Jenkinson, R. (Richard); Laughlin, R. (Richard); R.P.R. Groenendijk (Richard); Gurich, R.W. (Richard W.); Worman, R. (Ripley); Silvis, R. (Rob); R. Haverlag (Robert); Teasdall, R.J. (Robert J.); Korley, R. (Robert); McCormack, R. (Robert); Probe, R. (Robert); Cantu, R.V. (Robert V.); Huff, R.B. (Roger B.); R.K.J. Simmermacher; Peters, R. (Rolf); Pfeifer, R. (Roman); Liem, R. (Ronald); Wessel, R.N. (Ronald N.); Verhagen, R. (Ronald); Vuylsteke, R. (Ronald); Leighton, R. (Ross); McKercher, R. (Ross); R.W. Poolman (Rudolf); Miller, R. (Russell); Bicknell, R. (Ryan); Finnan, R. (Ryan); Khan, R.M. (Ryan M.); Mehta, S. (Samir); Vang, S. (Sandy); Singh, S. (Sanjay); Anand, S. (Sanjeev); Anderson, S.A. (Sarah A.); Dawson, S.A. (Sarah A.); Marston, S.B. (Scott B.); Porter, S.E. (Scott E.); Watson, S.T. (Scott T.); S. Festen (Sebastiaan); Lieberman, S. (Shane); Puloski, S. (Shannon); Bielby, S.A. (Shea A.); Sprague, S. (Sheila); Hess, S. (Shelley); MacDonald, S. (Shelley); Evans, S. (Simone); Bzovsky, S. (Sofia); Hasselund, S. (Sondre); Lewis, S. (Sophie); Ugland, S. (Stein); Caminiti, S. (Stephanie); Tanner, S.L. (Stephanie L.); S.M. Zielinski (Stephanie); Shepard, S. (Stephanie); Sems, S.A. (Stephen A.); Walter, S.D. (Stephen D.); Doig, S. (Stephen); Finley, S.H. (Stephen H.); Kates, S. (Stephen); Lindenbaum, S. (Stephen); Kingwell, S.P. (Stephen P.); Csongvay, S. (Steve); Papp, S. (Steve); Buijk, S.E. (Steven E.); S. Rhemrev (Steven); Hollenbeck, S.M. (Steven M.); van Gaalen, S.M. (Steven M.); Yang, S. (Steven); Weinerman, S. (Stuart); Subash, (); Lambert, S. (Sue); Liew, S. (Susan); S.A.G. Meylaerts (Sven); Blokhuis, T.J. (Taco J.); de Vries Reilingh, T.S. (Tammo S.); Lona, T. (Tarjei); Scott, T. (Taryn); Swenson, T.K. (Teresa K.); Endres, T.J. (Terrence J.); Axelrod, T. (Terry); van Egmond, T. (Teun); Pace, T.B. (Thomas B.); Kibsgård, T. (Thomas); Schaller, T.M. (Thomas M.); Ly, T.V. (Thuan V.); Miller, T.J. (Timothy J.); Weber, T. (Timothy); Le, T. (Toan); Oliver, T.M. (Todd M.); T.M. Karsten (Thomas); Borch, T. (Tor); Hoseth, T.M. (Tor Magne); Nicolaisen, T. (Tor); Ianssen, T. (Torben); Rutherford, T. (Tori); Nanney, T. (Tracy); Gervais, T. (Trevor); Stone, T. (Trevor); Schrickel, T. (Tyson); Scrabeck, T. (Tyson); Ganguly, U. (Utsav); Naumetz, V. (V.); Frizzell, V. (Valda); Wadey, V. (Veronica); Jones, V. (Vicki); Avram, V. (Victoria); Mishra, V. (Vimlesh); Yadav, V. (Vineet); Arora, V. (Vinod); Tyagi, V. (Vivek); Borsella, V. (Vivian); W.J. Willems (Jaap); Hoffman, W.H. (W. H.); Gofton, W.T. (Wade T.); Lackey, W.G. (Wesley G.); Ghent, W. (Wesley); Obremskey, W. (William); Oxner, W. (William); Cross, W.W. (William W.); Murtha, Y.M. (Yvonne M.); Murdoch, Z. (Zoe)

    2017-01-01

    textabstractBackground Reoperation rates are high after surgery for hip fractures. We investigated the effect of a sliding hip screw versus cancellous screws on the risk of reoperation and other key outcomes. Methods For this international, multicentre, allocation concealed randomised controlled

  15. On the fracture of human dentin: Is it stress- orstrain-controlled?

    Energy Technology Data Exchange (ETDEWEB)

    Nalla, R.K.; Kinney, J.H.; Ritchie, R.O.

    2006-02-01

    Despite substantial clinical interest in the fracture resistance of human dentin, there is little mechanistic information in archival literature that can be usefully used to model such fracture. In fact, although the fracture event indent in, akin to other mineralized tissues like bone, is widely believed to be locally strain-controlled, there has never been any scientific proof to support this belief. The present study seeks to address this issue through the use of a novel set of in vitro experiments in Hanks' balanced salt solution involving a double-notched bend test geometry, which is designed to discern whether the critical failure events involved in the onset of fracture are locally stress- or strain-controlled. Such experiments are further used to characterize the notion of ''plasticity'' in dentin and the interaction of cracks with the salient microstructural features. It is observed that fracture in dentin is indeed locally strain-controlled and that the presence of dentinal tubules does not substantially affect this process of crack initiation and growth. The results presented are believed to be critical steps in the development of a micromechanical model for the fracture of human dentin that takes into consideration the influence of both the microstructure and the local failure mode.

  16. Control system design method

    Science.gov (United States)

    Wilson, David G [Tijeras, NM; Robinett, III, Rush D.

    2012-02-21

    A control system design method and concomitant control system comprising representing a physical apparatus to be controlled as a Hamiltonian system, determining elements of the Hamiltonian system representation which are power generators, power dissipators, and power storage devices, analyzing stability and performance of the Hamiltonian system based on the results of the determining step and determining necessary and sufficient conditions for stability of the Hamiltonian system, creating a stable control system based on the results of the analyzing step, and employing the resulting control system to control the physical apparatus.

  17. Regulatory controls and slurry fracture injection

    International Nuclear Information System (INIS)

    Dusseault, M. B.; Bilak, R. A.

    1997-01-01

    The technological and regulatory framework necessary for the safe operation of solid waste disposal using slurry fracture injection (SFI) in Saskatchewan and Alberta was studied. Seven current SFI sites were used as the source of experience. Regular audits of volumes, continuous pressure recording, careful deformation monitoring and analysis, and repeated evaluation of reservoir properties were considered to be the essential features. In the case of toxic wastes, microseismic monitoring and regular well interference or tracer tests might be additional measures used to increase confidence in the containment method. Given the recent introduction of SFI technology, guarding against over-regulation was recommended to allow SFI to operate under the most effective operating conditions, and to preserve its attractiveness as an environmentally attractive and safe waste disposal alternative. 5 refs., 3 tabs., 4 figs

  18. Environmental controls on micro fracture processes in shelf ice

    Science.gov (United States)

    Sammonds, Peter

    2013-04-01

    The recent retreat and collapse of the ice shelves on the Antarctic Peninsula has been associated with regional atmospheric warming, oceanic warming, increased summer melt and shelf flexure. Although the cause of collapse is a matter of active discussion, the process is that of fracture of a creep-brittle material, close to its melting point. The environmental controls on how fracturing initiates, at a micro-scale, strongly determine the macroscopic disintegration of ice shelves. In particular the shelf temperature profile controls the plasticity of the ice shelf; the densification of shelf ice due to melting and re-freezing affects the crack tip stress intensity; the accretion of marine ice at the bottom of the shelf imposes a thermal/mechanical discontinuity; saline environments control crack tip stress corrosion; cyclic loading promotes sub-critical crack propagation. These strong environmental controls on shelf ice fracture means that assessing shelf stability is a non-deterministic problem. How these factors may be parameterized in ice shelf models, through the use of fracture mechanisms maps, is discussed. The findings are discussed in relation to the stability of Larsen C.

  19. BMD T-score discriminates trochanteric fractures from unfractured controls, whereas geometry discriminates cervical fracture cases from unfractured controls of similar BMD.

    Science.gov (United States)

    Pulkkinen, P; Partanen, J; Jalovaara, P; Jämsä, T

    2010-07-01

    The ability of bone mineral density (BMD) to discriminate cervical and trochanteric hip fractures was studied. Since the majority of fractures occur among people who are not diagnosed as having osteoporosis, we also examined this population to elucidate whether geometrical risk factors can yield additional information on hip fracture risk beside BMD. The study showed that the T-score criterion was able to discriminate fracture patients from controls in the cases of trochanteric fractures, whereas geometrical measures may discriminate cervical fracture cases in patients with T-score >-2.5. Low bone mineral density (BMD) is a well-established risk factor for hip fracture. However, majority of fractures occur among people not diagnosed as having osteoporosis. We studied the ability of BMD to discriminate cervical and trochanteric hip fractures. Furthermore, we examined whether geometrical measures can yield additional information on the assessment of hip fracture risk in the fracture cases in subjects with T-score >-2.5. Study group consisted of postmenopausal females with non-pathologic cervical (n = 39) or trochanteric (n = 18) hip fracture (mean age 74.2 years) and 40 age-matched controls. BMD was measured at femoral neck, and femoral neck axis length, femoral neck and shaft cortex thicknesses (FNC and FSC), and femoral neck-shaft angle (NSA) were measured from radiographs. BMD T-score threshold of -2.5 was able to discriminate trochanteric fractures from controls (p trochanteric fractures occurred in individuals with T-score fractures. Twenty of these fractures (51.3%) occurred in individuals with BMD in osteoporotic range and 19 (48.7%) in individuals with T-score >-2.5. Within these non-osteoporotic cervical fracture patients (N = 19) and non-osteoporotic controls (N = 35), 83.3% were classified correctly based on a model including NSA and FNC (p trochanteric fractures could be discriminated based on a BMD T-score fracture cases would remain under-diagnosed if

  20. Early age fracture properties of microstructurally-designed mortars

    DEFF Research Database (Denmark)

    Di Bella, Carmelo; Michel, Alexander; Stang, Henrik

    2017-01-01

    This paper compares the fracture properties as well as crack initiation and propagation of real and equivalent mortars. The development of the elastic modulus, tensile strength, and fracture energy at different hydration stages were determined by inverse analysis of load-displacement curves...... the two mortars. At early age, the moisture content has a considerable influence on the tensile strength and the fracture energy....

  1. Pattern Recognition Control Design

    Science.gov (United States)

    Gambone, Elisabeth A.

    2018-01-01

    Spacecraft control algorithms must know the expected vehicle response to any command to the available control effectors, such as reaction thrusters or torque devices. Spacecraft control system design approaches have traditionally relied on the estimated vehicle mass properties to determine the desired force and moment, as well as knowledge of the effector performance to efficiently control the spacecraft. A pattern recognition approach was used to investigate the relationship between the control effector commands and spacecraft responses. Instead of supplying the approximated vehicle properties and the thruster performance characteristics, a database of information relating the thruster ring commands and the desired vehicle response was used for closed-loop control. A Monte Carlo simulation data set of the spacecraft dynamic response to effector commands was analyzed to establish the influence a command has on the behavior of the spacecraft. A tool developed at NASA Johnson Space Center to analyze flight dynamics Monte Carlo data sets through pattern recognition methods was used to perform this analysis. Once a comprehensive data set relating spacecraft responses with commands was established, it was used in place of traditional control methods and gains set. This pattern recognition approach was compared with traditional control algorithms to determine the potential benefits and uses.

  2. [Fracture resistance of Procera Allceram depending on the framework design--an in vitro study].

    Science.gov (United States)

    Hagmann, Edgar; Marinello, Carlo P; Zitzmann, Nicola U

    2006-01-01

    Procera AllCeram is one of the all-ceramic systems with an aluminium-oxide core employing CAD/CAM technology. The aim of the current study was to investigate the fracture resistance of Procera AllCeram full-ceramic crowns with a reduced core design compared to the conventional method. In addition, a possible influence of the preparation form (molars or premolars) and the cementation material (glas-ionomer or composite) was analyzed. For both preparation forms, 30 ceramic cores with reduced margins (collarless cores, test) and 30 cores with extended cores (control) were veneered with porcelain in a standardized procedure (total 120 crowns). For the test group, Procera-AllCeram-margin ceramic material was used for the porcelain collar. 40 crowns each were cemented on stainless steel dies with either Ketac-Cem Aplicap or Panavia F. The additional 40 crowns were set on polyurethane dies without cementation and occlusally loaded until fracture occurred. Among the molar crowns, no differences were observed in fracture resistance neither for the different core designs (test or control) nor for the cementation materials. For the premolar form, fusing of a porcelain margin was associated with a reduction in fracture resistance, while the use of composite cement was accompanied with an increase. The present in vitro results indicate that for Procera AllCeram crowns with a highly undulating preparation margin, a conventional core design combined with adhesive cementation is preferable, especially in the posterior region due to higher chewing forces; this assumption needs to be proven in clinical studies.

  3. Structural-Diagenetic Controls on Fracture Opening in Tight Gas Sandstone Reservoirs, Alberta Foothills

    Science.gov (United States)

    Ukar, Estibalitz; Eichhubl, Peter; Fall, Andras; Hooker, John

    2013-04-01

    relatively undeformed backlimb strata. Fracture apertures locally increase adjacent to reverse faults without an overall increase in fracture frequency. Fluid inclusion analyses of crack-seal quartz cement indicate both aqueous and methane-rich inclusions are present. Homogenization temperatures of two-phase inclusions indicate synkinematic fracture cement precipitation and fracture opening under conditions at or near maximum burial of 190-210°C in core samples, and 120-160°C in outcrop samples. In comparison with the fracture evolution in other, less deformed tight-gas sandstone reservoirs such as the Piceance and East Texas basins where fracture opening is primarily controlled by gas generation, gas charge, and pore fluid pressure, these results suggest a strong control of regional tectonic processes on fracture generation. In conjunction with timing and rate of gas charge, rates of fracture cement growth, and stratigraphic-lithological controls, these processes determine the overall distribution of open fractures in these reservoirs.

  4. Design of experimental system for supercritical CO2 fracturing under confining pressure conditions

    Science.gov (United States)

    Wang, H.; Lu, Q.; Li, X.; Yang, B.; Zheng, Y.; Shi, L.; Shi, X.

    2018-03-01

    Supercritical CO2 has the characteristics of low viscosity, high diffusion and zero surface tension, and it is considered as a new fluid for non-polluting and non-aqueous fracturing which can be used for shale gas development. Fracturing refers to a method of utilizing the high-pressure fluid to generate fractures in the rock formation so as to improve the oil and gas flow conditions and increase the oil and gas production. In this article, a new type of experimental system for supercritical CO2 fracturing under confining pressure conditions is designed, which is based on characteristics of supercritical CO2, shale reservoir and down-hole environment. The experimental system consists of three sub-systems, including supercritical CO2 generation system, supercritical CO2 fracturing system and data analysis system. It can be used to simulate supercritical CO2 fracturing under geo-stress conditions, thus to study the rock initiation pressure, the formation of the rock fractures, fractured surface morphology and so on. The experimental system has successfully carried out a series of supercritical CO2 fracturing experiments. The experimental results confirm the feasibility of the experimental system and the high efficiency of supercritical CO2 in fracturing tight rocks.

  5. Micromechanical studies of cyclic creep fracture under stress controlled loading

    DEFF Research Database (Denmark)

    van der Giessen, Erik; Tvergaard, Viggo

    1996-01-01

    is based on numerical unit cell analyses for a planar polycrystal model with the grains and grain boundaries modeled individually, in order to investigate the interactions between the mechanisms involved and to account for the build-up of residual stress fields during cycling. The behaviour of a limiting......This paper deals with a study of intergranular failure by creep cavitation under stress-controlled cyclic loading conditions. Loading is assumed to be slow enough that diffusion and creep mechanisms (including grain boundary sliding) dominate, leading to intergranular creep fracture. This study...

  6. Design and construction of an experiment for two-phase flow in fractured porous media

    Energy Technology Data Exchange (ETDEWEB)

    Ayala, R.E.G.; Aziz, K.

    1993-08-01

    In numerical reservoir simulation naturally fractured reservoirs are commonly divided into matrix and fracture systems. The high permeability fractures are usually entirely responsible for flow between blocks and flow to the wells. The flow in these fractures is modeled using Darcy`s law and its extension to multiphase flow by means of relative permeabilities. The influence and measurement of fracture relative permeability for two-phase flow in fractured porous media have not been studied extensively, and the few works presented in the literature are contradictory. Experimental and numerical work on two-phase flow in fractured porous media has been initiated. An apparatus for monitoring this type of flow was designed and constructed. It consists of an artificially fractured core inside an epoxy core holder, detailed pressure and effluent monitoring, saturation measurements by means of a CT-scanner and a computerized data acquisition system. The complete apparatus was assembled and tested at conditions similar to the conditions expected for the two-phase flow experiments. Fine grid simulations of the experimental setup-were performed in order to establish experimental conditions and to study the effects of several key variables. These variables include fracture relative permeability and fracture capillary pressure. The numerical computations show that the flow is dominated by capillary imbibition, and that fracture relative permeabilities have only a minor influence. High oil recoveries without water production are achieved due to effective water imbibition from the fracture to the matrix. When imbibition is absent, fracture relative permeabilities affect the flow behavior at early production times.

  7. Effect of interfragmentary gap on the mechanical behavior of mandibular angle fracture with three fixation designs: A finite element analysis.

    Science.gov (United States)

    Wang, Russell; Liu, Yunfeng; Wang, Joanne Helen; Baur, Dale Allen

    2017-03-01

    The aim of this study was to simulate stress and strain distribution numerically on a normal mandible under physiological occlusal loadings. The results were compared with those of mandibles that had an angle fracture stabilized with different fixation designs under the same loadings. The amount of displacement at two interfragmentary gaps was also studied. A three-dimensional (3D) virtual mandible was reconstructed with an angle fracture that had a fracture gap of either 0.1 or 1 mm. Three types of plate fixation designs were used: Type I, a miniplate was placed across the fracture line following the Champy technique; Type II, two miniplates were used; and Type III, a reconstruction plate was used on the inferior border of the mandible. Loads of 100 and 500 N were applied to the models. The maximum von Mises stress, strain, and displacement were computed using finite element analysis. The results from the control and experimental groups were analyzed and compared. The results demonstrated that high stresses and strains were distributed to the condylar and angular areas regardless of the loading position. The ratio of the plate/bone average stress ranged from 215% (Type II design) to 848% (Type I design) irrespective of the interfragmentary gap size. With a 1-mm fracture gap, the ratio of the plate/bone stress ranged from 204% (Type II design) to 1130% (Type I design). All strains were well below critical bone strain thresholds. Displacement on the cross-sectional mapping at fracture interface indicated that uneven movement occurred in x, y, and z directions. Interfragmentary gaps between 0.1 and 1 mm did not have a substantial effect on the average stress distribution to the fractured bony segments; however, they had a greater effect on the stress distribution to the plates and screws. Type II fixation was the best mechanical design under bite loads. Type I design was the least stable system and had the highest stress distribution and the largest displacement

  8. Controller design for interval plants

    International Nuclear Information System (INIS)

    Al-Sunni, F.M.

    2003-01-01

    We make use of celebrated Kharitoniv theorem to come up with a design procedure for the stabilization of uncertain systems in the parameters using low order controllers. The proposed design is based on classical design methods. A Non-linear programming (NLP) approach for the design of higher order controllers is also presented. We present our results and give illustrating examples. (author)

  9. Physiotherapy Rehabilitation for Osteoporotic Vertebral Fracture (PROVE): study protocol for a randomised controlled trial

    Science.gov (United States)

    2014-01-01

    Background Osteoporosis and vertebral fracture can have a considerable impact on an individual’s quality of life. There is increasing evidence that physiotherapy including manual techniques and exercise interventions may have an important treatment role. This pragmatic randomised controlled trial will investigate the clinical and cost-effectiveness of two different physiotherapy approaches for people with osteoporosis and vertebral fracture, in comparison to usual care. Methods/Design Six hundred people with osteoporosis and a clinically diagnosed vertebral fracture will be recruited and randomly allocated to one of three management strategies, usual care (control - A), an exercise-based physiotherapy intervention (B) or a manual therapy-based physiotherapy intervention (C). Those in the usual care arm will receive a single session of education and advice, those in the active treatment arms (B + C) will be offered seven individual physiotherapy sessions over 12 weeks. The trial is designed as a prospective, adaptive single-blinded randomised controlled trial. An interim analysis will be completed and if one intervention is clearly superior the trial will be adapted at this point to continue with just one intervention and the control. The primary outcomes are quality of life measured by the disease specific QUALLEFO 41 and the Timed Loaded Standing test measured at 1 year. Discussion There are a variety of different physiotherapy packages used to treat patients with osteoporotic vertebral fracture. At present, the indication for each different therapy is not well defined, and the effectiveness of different modalities is unknown. Trial registration Reference number ISRCTN49117867. PMID:24422876

  10. Design and Implementation of Energized Fracture Treatment in Tight Gas Sands

    Energy Technology Data Exchange (ETDEWEB)

    Mukul Sharma; Kyle Friehauf

    2009-12-31

    , the minimum CO{sub 2} gas quality (volume % of gas) recommended is 30% for moderate differences between fracture and reservoir pressures (2900 psi reservoir, 5300 psi fracture). The minimum quality is reduced to 20% when the difference between pressures is larger, resulting in additional gas expansion in the invaded zone. Inlet fluid temperature, flow rate, and base viscosity did not have a large impact on fracture production. Finally, every stage of the fracturing treatment should be energized with a gas component to ensure high gas saturation in the invaded zone. A second, more general, sensitivity study was conducted. Simulations show that CO{sub 2} outperforms N{sub 2} as a fluid component because it has higher solubility in water at fracturing temperatures and pressures. In fact, all gas components with higher solubility in water will increase the fluid's ability to reduce damage in the invaded zone. Adding methanol to the fracturing solution can increase the solubility of CO{sub 2}. N{sub 2} should only be used if the gas leaks-off either during the creation of the fracture or during closure, resulting in gas going into the invaded zone. Experimental data is needed to determine if the gas phase leaks-off during the creation of the fracture. Simulations show that the bubbles in a fluid traveling across the face of a porous medium are not likely to attach to the surface of the rock, the filter cake, or penetrate far into the porous medium. In summary, this research has created the first compositional fracturing simulator, a useful tool to aid in energized fracture design. We have made several important and original conclusions about the best practices when using energized fluids in tight gas sands. The models and tools presented here may be used in the future to predict behavior of any multi-phase or multi-component fracturing fluid system.

  11. Controls on wind abrasion patterns through a fractured bedrock landscape

    Science.gov (United States)

    Perkins, J. P.; Finnegan, N. J.

    2017-12-01

    Wind abrasion is an important geomorphic process for understanding arid landscape evolution on Earth and interpreting the post-fluvial history of Mars. Both the presence and orientation of wind-abraded landforms provide potentially important constraints on paleo-climatic conditions; however, such interpretations can be complicated by lithologic and structural heterogeneity. To explore the influence of pre-existing structure on wind abrasion, we exploit a natural experiment along the 10.2 Ma Lower Rio San Pedro ignimbrite in northern Chile. Here, a 3.2 Ma andesite flow erupted from Cerro de las Cuevas and deposited atop the ignimbrite, supplying wind-transportable sediment and initiating a phase of downwind abrasion. Additionally, the lava flow provides a continually varying degree of upwind topographic shielding along the ignimbrite that is reflected in a range of surface morphologies. Where fully shielded the ignimbrite surface is partially blanketed by sediment. However, as relief decreases the surface morphology shifts from large polygonal structures that emerge due to the concentration of wind abrasion along pre-existing fracture sets, to polygons that are bisected by wind-parallel grooves that cross-cut fracture sets, to linear sets of yardangs. We reconstruct the ignimbrite surface using a high-resolution digital elevation model, and calculate erosion rates ranging from 0.002 to 0.45 mm/kyr that vary strongly with degree of topographic shielding (R2 = 0.97). We use measured abrasion rates together with nearby weather station data to estimate the nondimensional Rouse number and Inertial Parameter for a range of particle sizes. From these calculations, we hypothesize that the change from fracture-controlled to flow-controlled morphology reflects increases in the grain size and inertia of particles in the suspension cloud. Where the ignimbrite experiences persistent high winds, large particles may travel in suspension and are largely insensitive to topographic

  12. Partnership for fragility bone fracture care provision and prevention program (P4Bones: study protocol for a secondary fracture prevention pragmatic controlled trial

    Directory of Open Access Journals (Sweden)

    Gaboury Isabelle

    2013-01-01

    Full Text Available Abstract Background Fractures associated with bone fragility in older adults signal the potential for secondary fracture. Fragility fractures often precipitate further decline in health and loss of mobility, with high associated costs for patients, families, society and the healthcare system. Promptly initiating a coordinated, comprehensive pharmacological bone health and falls prevention program post-fracture may improve osteoporosis treatment compliance; and reduce rates of falls and secondary fractures, and associated morbidity, mortality and costs. Methods/design This pragmatic, controlled trial at 11 hospital sites in eight regions in Quebec, Canada, will recruit community-dwelling patients over age 50 who have sustained a fragility fracture to an intervention coordinated program or to standard care, according to the site. Site study coordinators will identify and recruit 1,596 participants for each study arm. Coordinators at intervention sites will facilitate continuity of care for bone health, and arrange fall prevention programs including physical exercise. The intervention teams include medical bone specialists, primary care physicians, pharmacists, nurses, rehabilitation clinicians, and community program organizers. The primary outcome of this study is the incidence of secondary fragility fractures within an 18-month follow-up period. Secondary outcomes include initiation and compliance with bone health medication; time to first fall and number of clinically significant falls; fall-related hospitalization and mortality; physical activity; quality of life; fragility fracture-related costs; admission to a long term care facility; participants’ perceptions of care integration, expectations and satisfaction with the program; and participants’ compliance with the fall prevention program. Finally, professionals at intervention sites will participate in focus groups to identify barriers and facilitating factors for the integrated

  13. Prevalence of overweight in children with bone fractures: a case control study.

    Science.gov (United States)

    Valerio, Giuliana; Gallè, Francesca; Mancusi, Caterina; Di Onofrio, Valeria; Guida, Pasquale; Tramontano, Antonino; Ruotolo, Edoardo; Liguori, Giorgio

    2012-10-22

    Children's fractures have been enlisted among orthopaedics complaints of childhood obesity. Unhealthy lifestyle behaviours may contribute to increased risk. This study described the prevalence of overweight/obesity in children and adolescents reporting a recent fracture in relation to gender, dynamic of trauma, and site of fracture. Four-hundred-forty-nine children and adolescents with fracture and 130 fracture-free controls were recruited from a large children's hospital. The interaction between overweight and gender, dynamic of trauma, site of fracture was explored. Sports participation, television viewing, and calcium intake were also investigated. Overweight/obesity rate was increased in girls with fracture either at the upper or the lower limb (p= 0.004), while it was increased only in boys with fracture at the lower limb (p fractures than controls (61.5% vs 34.5%, p =0.015) in the overweight/obese group. The increased prevalence of overweight/obesity in children with fractures is related to gender and site of fracture. Higher levels of sedentary behaviours characterize overweight children reporting fractures.

  14. Controlling rotational deformity in ankle fractures : the Bridgend ...

    African Journals Online (AJOL)

    Management. Recognition of the forces is usually possible by observing the pattern of the fracture lines, especially in the fibula. Abduction and adduction forces cause transverse or short oblique fracture lines near the level of the ankle joint (Fig 1) whereas rotation forces produce spiral fractures of the fibula above the level ...

  15. Can paramedics use FRAX (the WHO Fracture Risk Assessment Tool) to help GPs improve future fracture risk in patients who fall? Protocol for a randomised controlled feasibility study.

    Science.gov (United States)

    Clarke, Shane; Bradley, Rachel; Simmonds, Bethany; Salisbury, Chris; Benger, Jonathan; Marques, Elsa; Greenwood, Rosemary; Shepstone, Lee; Robinson, Maria; Appleby-Fleming, John; Gooberman-Hill, Rachael

    2014-09-03

    Currently identification, and therefore, management of patients at risk of osteoporotic fracture in the UK is suboptimal. As the majority of patients who fracture have fallen, it follows that people who fall can usefully be targeted in any programme that aims to reduce osteoporotic fracture. Targeting vulnerable patients who are likely to benefit from intervention may help shift the management of fracture prevention into primary care, away from emergency departments. Paramedics who attend to patients who have fallen may be well placed to assess future fracture risk, using the Fracture Risk Assessment Tool (FRAX) and communicate that information directly to general practitioners (GPs). This feasibility study takes the form of a pragmatic, randomised controlled trial aimed at exploring and refining issues of study design, recruitment, retention, sample size and acceptability preceding a large-scale study with fracture as the end point. Patients (aged >50) who fall, call an ambulance, are attended by a study paramedic and give verbal consent will be asked FRAX and fall questions. Patients who subsequently formally consent to participation will be randomised to control (usual care) or intervention groups. Intervention will constitute transmission of calculated future fracture risk to the patients' GP with suitable, evidence-based recommendations for investigation or treatment. 3 months after the index fall, data (proportion of patients in each group undergoing investigation or starting new treatment, quality of life and health economic) will be collected and analysed using descriptive statistics. A nested qualitative study will explore issues of acceptability and study design with patients, paramedics and GPs. This protocol was approved by NRES Committee South Central Oxford C in October 2012. Research Ethics Committee ref.12/SC/0604. The study findings will be disseminated through peer-reviewed journals, conference presentations and local public events. A publication

  16. On the fracture of human dentin: Is it stress- orstrain-controlled?

    Energy Technology Data Exchange (ETDEWEB)

    Nalla, R.K.; Kinney, J.H.; Ritchie, R.O.

    2006-02-01

    Despite substantial clinical interest in the fractureresistance of human dentin, there is little mechanistic information inarchival literature that can be usefully used to model such fracture. Infact, although the fracture event indent in, akin to other mineralizedtissues like bone, is widely believed to be locally strain-controlled,there has never been any scientific proof to support this belief. Thepresent study seeks to address this issue through the use of a novel setof in vitro experiments in Hanks' balanced salt solution involving adouble-notched bend test geometry, which is designed to discern whetherthe critical failure events involved in the onset of fracture are locallystress- or strain-controlled. Such experiments are further used tocharacterize the notion of "plasticity" in dentin and the interaction ofcracks with the salient microstructural features. It is observed thatfracture in dentin is indeed locally strain-controlled and that thepresence of dentinal tubules does not substantially affect this processof crack initiation and growth. The results presented are believed to becritical steps in the development ofa micromechanical model for thefracture of human dentin that takes into consideration the influence ofboth the microstructure and the local failure mode.

  17. A fracture-controlled path-following technique for phase-field modeling of brittle fracture

    NARCIS (Netherlands)

    Singh, N.; Verhoosel, C.V.; De Borst, R.; Van Brummelen, E.H.

    2016-01-01

    In the phase-field description of brittle fracture, the fracture-surface area can be expressed as a functional of the phase field (or damage field). In this work we study the applicability of this explicit expression as a (non-linear) path-following constraint to robustly track the equilibrium path

  18. Knee-extension strength, postural control and function are related to fracture type and thigh edema in patients with hip fracture

    DEFF Research Database (Denmark)

    Kristensen, Morten T; Bandholm, Thomas; Bencke, Jesper

    2008-01-01

    BACKGROUND: Post-surgery thigh edema, loss of knee-extension strength, and reduced physical performance are common following a hip fracture. It is not known if knee-extension strength and physical performance are related to the edema and fracture type. The aim of this study was to examine...... the influence of fracture type and post-surgery edema on physical performances in patients with hip fracture. METHODS: Fifteen women and five men admitted from their own home to an acute orthopedic hip fracture unit were examined. Ten had cervical and ten had intertrochanteric fractures. Correlations between...... fracture type and thigh edema in the fractured limb (% non-fractured) to physical performances of basic mobility, postural control (sway), and isometric knee-extension strength were examined. All measures, except those of basic mobility, were conducted at the time of discharge, 8.5 days post...

  19. Elastic Rock Heterogeneity Controls Brittle Rock Failure during Hydraulic Fracturing

    Science.gov (United States)

    Langenbruch, C.; Shapiro, S. A.

    2014-12-01

    For interpretation and inversion of microseismic data it is important to understand, which properties of the reservoir rock control the occurrence probability of brittle rock failure and associated seismicity during hydraulic stimulation. This is especially important, when inverting for key properties like permeability and fracture conductivity. Although it became accepted that seismic events are triggered by fluid flow and the resulting perturbation of the stress field in the reservoir rock, the magnitude of stress perturbations, capable of triggering failure in rocks, can be highly variable. The controlling physical mechanism of this variability is still under discussion. We compare the occurrence of microseismic events at the Cotton Valley gas field to elastic rock heterogeneity, obtained from measurements along the treatment wells. The heterogeneity is characterized by scale invariant fluctuations of elastic properties. We observe that the elastic heterogeneity of the rock formation controls the occurrence of brittle failure. In particular, we find that the density of events is increasing with the Brittleness Index (BI) of the rock, which is defined as a combination of Young's modulus and Poisson's ratio. We evaluate the physical meaning of the BI. By applying geomechanical investigations we characterize the influence of fluctuating elastic properties in rocks on the probability of brittle rock failure. Our analysis is based on the computation of stress fluctuations caused by elastic heterogeneity of rocks. We find that elastic rock heterogeneity causes stress fluctuations of significant magnitude. Moreover, the stress changes necessary to open and reactivate fractures in rocks are strongly related to fluctuations of elastic moduli. Our analysis gives a physical explanation to the observed relation between elastic heterogeneity of the rock formation and the occurrence of brittle failure during hydraulic reservoir stimulations. A crucial factor for understanding

  20. Pulsed Electromagnetic Fields in the treatment of fresh scaphoid fractures. A multicenter, prospective, double blind, placebo controlled, randomized trial

    Directory of Open Access Journals (Sweden)

    Poeze Martijn

    2011-05-01

    Full Text Available Abstract Background The scaphoid bone is the most commonly fractured of the carpal bones. In the Netherlands 90% of all carpal fractures is a fracture of the scaphoid bone. The scaphoid has an essential role in functionality of the wrist, acting as a pivot. Complications in healing can result in poor functional outcome. The scaphoid fracture is a troublesome fracture and failure of treatment can result in avascular necrosis (up to 40%, non-union (5-21% and early osteo-arthritis (up to 32% which may seriously impair wrist function. Impaired consolidation of scaphoid fractures results in longer immobilization and more days lost at work with significant psychosocial and financial consequences. Initially Pulsed Electromagnetic Fields was used in the treatment of tibial pseudoarthrosis and non-union. More recently there is evidence that physical forces can also be used in the treatment of fresh fractures, showing accelerated healing by 30% and 71% reduction in nonunion within 12 weeks after initiation of therapy. Until now no double blind randomized, placebo controlled trial has been conducted to investigate the effect of this treatment on the healing of fresh fractures of the scaphoid. Methods/Design This is a multi center, prospective, double blind, placebo controlled, randomized trial. Study population consists of all patients with unilateral acute scaphoid fracture. Pregnant women, patients having a life supporting implanted electronic device, patients with additional fractures of wrist, carpal or metacarpal bones and pre-existing impairment in wrist function are excluded. The scaphoid fracture is diagnosed by a combination of physical and radiographic examination (CT-scanning. Proven scaphoid fractures are treated with cast immobilization and a small Pulsed Electromagnetic Fields bone growth stimulating device placed on the cast. Half of the devices will be disabled at random in the factory. Study parameters are clinical consolidation

  1. Design philosophy and practice of asymmetrical 3D fracturing and random fracturing: A case study of tight sand gas reservoirs in western Sichuan Basin

    Directory of Open Access Journals (Sweden)

    Jianchun Guo

    2015-03-01

    Full Text Available At present two technical models are commonly taken in tight gas reservoir stimulation: conventional massive fracturing and SRV fracturing, but how to select a suitable fracturing model suitable for reservoir characteristics is still a question waiting to be answered. In this paper, based on the analysis of geological characteristics and seepage mechanism of tight gas and shale gas reservoirs, the differences between stimulation philosophy of tight gas reservoirs and shale reservoirs are elucidated, and the concept that a suitable stimulation model should be selected based on reservoir geological characteristics and seepage mechanism aiming at maximally improving the seepage capability of a reservoir. Based on this concept, two fracturing design methods were proposed for two tight gas reservoirs in western Sichuan Basin: asymmetrical 3D fracturing design (A3DF for the middle-shallow Upper Jurassic Penglaizhen Fm stacked reservoirs in which the hydraulic fractures can well match the sand spatial distribution and seepage capability of the reservoirs; SRV fracturing design which can increase fracture randomness in the sandstone and shale laminated reservoirs for the 5th Member of middle-deep Upper Triassic Xujiahe Fm. Compared with that by conventional fracturing, the average production of horizontal wells fractured by A3DF increased by 41%, indicating that A3DF is appropriate for gas reservoir development in the Penglaizhen Fm; meanwhile, the average production per well of the 5th Member of the Xujiahe Fm was 2.25 × 104 m3/d after SRV fracturing, showing that the SRV fracturing is a robust technical means for the development of this reservoir.

  2. Earthquake design for controlled structures

    Directory of Open Access Journals (Sweden)

    Nikos G. Pnevmatikos

    2017-04-01

    Full Text Available An alternative design philosophy, for structures equipped with control devices, capable to resist an expected earthquake while remaining in the elastic range, is described. The idea is that a portion of the earthquake loading is under¬taken by the control system and the remaining by the structure which is designed to resist elastically. The earthquake forces assuming elastic behavior (elastic forces and elastoplastic behavior (design forces are first calculated ac¬cording to the codes. The required control forces are calculated as the difference from elastic to design forces. The maximum value of capacity of control devices is then compared to the required control force. If the capacity of the control devices is larger than the required control force then the control devices are accepted and installed in the structure and the structure is designed according to the design forces. If the capacity is smaller than the required control force then a scale factor, α, reducing the elastic forces to new design forces is calculated. The structure is redesigned and devices are installed. The proposed procedure ensures that the structure behaves elastically (without damage for the expected earthquake at no additional cost, excluding that of buying and installing the control devices.

  3. The Vitamin D Assessment (ViDA) Study: design of a randomized controlled trial of vitamin D supplementation for the prevention of cardiovascular disease, acute respiratory infection, falls and non-vertebral fractures.

    Science.gov (United States)

    Scragg, Robert; Waayer, Debbie; Stewart, Alistair W; Lawes, Carlene M M; Toop, Les; Murphy, Judy; Khaw, Kay-Tee; Camargo, Carlos A

    2016-11-01

    Observational studies have shown that low vitamin D status is associated with an increased risk of cardiovascular disease, acute respiratory infection, falls and non-vertebral fractures. We recruited 5110 Auckland adults, aged 50-84 years, into a randomized, double-blind, placebo-controlled trial to test whether vitamin D supplementation protects against these four major outcomes. The intervention is a monthly cholecalciferol dose of 100,000IU (2.5mg) for an estimated median 3.3 years (range 2.5-4.2) during 2011-2015. Participants were recruited primarily from family practices, plus community groups with a high proportion of Maori, Pacific, or South Asian individuals. The baseline evaluation included medical history, lifestyle, physical measurements (e.g. blood pressure, arterial waveform, lung function, muscle function), and a blood sample (stored at -80°C for later testing). Capsules are being mailed to home addresses with a questionnaire to collect data on non-hospitalized outcomes and to monitor adherence and potential adverse effects. Other data sources include New Zealand Ministry of Health data on mortality, hospitalization, cancer registrations and dispensed pharmaceuticals. A random sample of 438 participants returned for annual collection of blood samples to monitor adherence and safety (hypercalcemia), including repeat physical measurements at 12 months follow-up. The trial will allow testing of a priori hypotheses on several other endpoints including: weight, blood pressure, arterial waveform parameters, heart rate variability, lung function, muscle strength, gait and balance, mood, psoriasis, bone density, and chronic pain. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. Prevalence of overweight in children with bone fractures: a case control study

    Directory of Open Access Journals (Sweden)

    Valerio Giuliana

    2012-10-01

    Full Text Available Abstract Background Children's fractures have been enlisted among orthopaedics complaints of childhood obesity. Unhealthy lifestyle behaviours may contribute to increased risk. This study described the prevalence of overweight/obesity in children and adolescents reporting a recent fracture in relation to gender, dynamic of trauma, and site of fracture. Methods Four-hundred-forty-nine children and adolescents with fracture and 130 fracture-free controls were recruited from a large children’s hospital. The interaction between overweight and gender, dynamic of trauma, site of fracture was explored. Sports participation, television viewing, and calcium intake were also investigated. Results Overweight/obesity rate was increased in girls with fracture either at the upper or the lower limb (p= 0.004, while it was increased only in boys with fracture at the lower limb (p Conclusions The increased prevalence of overweight/obesity in children with fractures is related to gender and site of fracture. Higher levels of sedentary behaviours characterize overweight children reporting fractures.

  5. Exposure to antiepileptic drugs and the risk of hip fracture: a case-control study

    DEFF Research Database (Denmark)

    Tsiropoulos, Ioannis; Andersen, Morten; Nymark, Tine

    2008-01-01

    PURPOSE: To investigate whether the use of antiepileptic drugs (AEDs) increases the risk of hip fracture. METHODS: We performed a case-control study using data from the Funen County (population 2004: 475,000) hip fracture register. Cases (n = 7,557) were all patients admitted to county hospitals...... with a hip fracture during the period 1996-2004. Controls (n = 27,575) were frequency matched by age and gender. Information on use of AEDs, other drugs, and hospital contacts was available from local registers. Odds ratios (ORs) with 95% confidence intervals (CI) for hip fracture were estimated...

  6. Secondary hyperparathyroidism and mortality in hip fracture patients compared to a control group from general practice

    DEFF Research Database (Denmark)

    Madsen, Christian Medom; Jørgensen, Henrik Løvendahl; Lind, Bent

    2012-01-01

    INTRODUCTION: Previously, little attention has been paid as to how disturbances in the parathyroid hormone (PTH)-calcium-vitamin D-axis, such as secondary hyperparathyroidism (SHPT), relate to mortality amongst hip fracture patients. This study aimed to (1) determine if SHPT is associated......) (age=70 years) admitted to a Danish university hospital. The hip fracture patients were prospectively enrolled in a dedicated hip fracture database. Each hip fracture patient was exactly matched according to age and sex with two controls randomly chosen from a control population of 21,778 subjects who...

  7. COMPARISON OF THE TRADITIONAL STRENGTH OF MATERIALS APPROACH TO DESIGN WITH THE FRACTURE MECHANICS APPROACH

    International Nuclear Information System (INIS)

    Z. Ceylan

    2002-01-01

    The objective of this activity is to show that the use of the traditional strength of materials approach to the drip shield and the waste package (WP) designs is bounding and appropriate when compared to the fracture mechanics approach. The scope of this activity is limited to determining the failure assessment diagrams for the two materials at issue: Ti-7 and Alloy 22. This calculation is intended for use in support of the license application design of the drip shield and the WP. This activity is associated with the drip shield and the WP designs. The activity evaluation for work package number P32 12234F2, included in ''Technical Work Plan for: Waste Package Design Description for LA'' (Ref. 1, p. A-6), has determined that the development of this document is subject to ''Quality Assurance Requirements and Description'' requirements. The control of the electronic management of data is accomplished in accordance with the methods specified in Reference 1, Section 10. AP-3.124, ''Design Calculations and Analysis'' (Ref. 2), is used to develop and document the calculation

  8. Vitamin D supplementation and fracture incidence in elderly persons : A randomized, placebo-controlled clinical trial

    NARCIS (Netherlands)

    Lips, Paul; Graafmans, Wilco C.; Ooms, Marcel E.; Bezemer, P. Dick; Bouter, Lex M.

    1996-01-01

    Objective: To determine whether vitamin D supplementation decreases the incidence of hip fractures and other peripheral bone fractures. Design: Prospective, double-blind trial. Setting: Community setting (Amsterdam and surrounding area). Patients: 2578 persons (1916 women, 662 men) 70 years of age

  9. Receiver-exciter controller design

    Science.gov (United States)

    Jansma, P. A.

    1982-01-01

    A description of the general design of both the block 3 and block 4 receiver-exciter controllers for the Deep Space Network (DSN) Mark IV-A System is presented along with the design approach. The controllers are designed to enable the receiver-exciter subsystem (RCV) to be configured, calibrated, initialized and operated from a central location via high level instructions. The RECs are designed to be operated under the control of the DMC subsystem. The instructions are in the form of standard subsystem blocks (SSBs) received via the local area network (LAN). The centralized control provided by RECs and other DSCC controllers in Mark IV-A is intended to reduce DSN operations costs from the Mark III era.

  10. Clastic patterned ground in Lomonosov crater, Mars: examining fracture controlled formation mechanisms

    Science.gov (United States)

    Barrett, Alexander M.; Balme, Matthew R.; Patel, Manish R.; Hagermann, Axel

    2017-10-01

    The area surrounding Lomonosov crater on Mars has a high density of seemingly organised boulder patterns. These form seemingly sorted polygons and stripes within kilometre scale blockfields, patches of boulder strewn ground which are common across the Martian high latitudes. Several hypotheses have been suggested to explain the formation of clastic patterned ground on Mars. It has been proposed that these structures could have formed through freeze-thaw sorting, or conversely by the interaction of boulders with underlying fracture polygons. In this investigation a series of sites were examined to evaluate whether boulder patterns appear to be controlled by the distribution of underlying fractures and test the fracture control hypotheses for their formation. It was decided to focus on this suite of mechanisms as they are characterised by a clear morphological relationship, namely the presence of an underlying fracture network which can easily be evaluated over a large area. It was found that in the majority of examples at these sites did not exhibit fracture control. Although fractures were present at many sites there were very few sites where the fracture network appeared to be controlling the boulder distribution. In general these were not the sites with the best examples of organization, suggesting that the fracture control mechanisms are not the dominant geomorphic process organising the boulders in this area.

  11. Design of a Clinical Decision Support System for Fracture Prediction Using Imbalanced Dataset

    Directory of Open Access Journals (Sweden)

    Yung-Fu Chen

    2018-01-01

    Full Text Available More than 1 billion people suffer from chronic respiratory diseases worldwide, accounting for more than 4 million deaths annually. Inhaled corticosteroid is a popular medication for treating chronic respiratory diseases. Its side effects include decreased bone mineral density and osteoporosis. The aims of this study are to investigate the association of inhaled corticosteroids and fracture and to design a clinical support system for fracture prediction. The data of patients aged 20 years and older, who had visited healthcare centers and been prescribed with inhaled corticosteroids within 2002–2010, were retrieved from the National Health Insurance Research Database (NHIRD. After excluding patients diagnosed with hip fracture or vertebrate fractures before using inhaled corticosteroid, a total of 11645 patients receiving inhaled corticosteroid therapy were included for this study. Among them, 1134 (9.7% were diagnosed with hip fracture or vertebrate fracture. The statistical results showed that demographic information, chronic respiratory diseases and comorbidities, and corticosteroid-related variables (cumulative dose, mean exposed daily dose, follow-up duration, and exposed duration were significantly different between fracture and nonfracture patients. The clinical decision support systems (CDSSs were designed with integrated genetic algorithm (GA and support vector machine (SVM by training and validating the models with balanced training sets obtained by random and cluster-based undersampling methods and testing with the imbalanced NHIRD dataset. Two different objective functions were adopted for obtaining optimal models with best predictive performance. The predictive performance of the CDSSs exhibits a sensitivity of 69.84–77.00% and an AUC of 0.7495–0.7590. It was concluded that long-term use of inhaled corticosteroids may induce osteoporosis and exhibit higher incidence of hip or vertebrate fractures. The accumulated dose of ICS and

  12. Grouting design based on characterization of the fractured rock. Presentation and demonstration of a methodology

    Energy Technology Data Exchange (ETDEWEB)

    Fransson, Aasa (SWECO Environment, Stockholm (Sweden); Chalmers Univ. of Technology, Goeteborg (Sweden))

    2008-12-15

    The design methodology presented in this document is based on an approach that considers the individual fractures. The observations and analyses made during production enable the design to adapt to the encountered conditions. The document is based on previously published material and overview flow charts are used to show the different steps. Parts of or the full methodology has been applied for a number of tunneling experiments and projects. SKB projects in the Aespoe tunnel include a pillar experiment and pre-grouting of a 70 meter long tunnel (TASQ). Further, for Hallandsas railway tunnel (Skaane south Sweden), a field pre-grouting experiment and design and post-grouting of a section of 133 meters have been made. For the Nygard railway tunnel (north of Goeteborg, Sweden), design and grouting of a section of 86 meters (pre-grouting) and 60 meters (post-grouting) have been performed. Finally, grouting work at the Tornskog tunnel (Stockholm, Sweden) included design and grouting along a 100 meter long section of one of the two tunnel tubes. Of importance to consider when doing a design and evaluating the result are: - The identification of the extent of the grouting needed based on inflow requirements and estimates of tunnel inflow before grouting. - The selection of grout and performance of grouting materials including penetration ability and length. The penetration length is important for the fan geometry design. - The ungrouted compared to the grouted and excavated rock mass conditions: estimates of tunnel inflow and (if available) measured inflows after grouting and excavation. Identify if possible explanations for deviations. For the Hallandsas, Nygard and Tornskog tunnel sections, the use of a Pareto distribution and the estimate of tunnel inflow identified a need for sealing small aperture fractures (< 50 - 100 mum) to meet the inflow requirements. The tunneling projects show that using the hydraulic aperture as a basis for selection of grout is a good

  13. Grouting design based on characterization of the fractured rock. Presentation and demonstration of a methodology

    International Nuclear Information System (INIS)

    Fransson, Aasa

    2008-12-01

    The design methodology presented in this document is based on an approach that considers the individual fractures. The observations and analyses made during production enable the design to adapt to the encountered conditions. The document is based on previously published material and overview flow charts are used to show the different steps. Parts of or the full methodology has been applied for a number of tunneling experiments and projects. SKB projects in the Aespoe tunnel include a pillar experiment and pre-grouting of a 70 meter long tunnel (TASQ). Further, for Hallandsas railway tunnel (Skaane south Sweden), a field pre-grouting experiment and design and post-grouting of a section of 133 meters have been made. For the Nygard railway tunnel (north of Goeteborg, Sweden), design and grouting of a section of 86 meters (pre-grouting) and 60 meters (post-grouting) have been performed. Finally, grouting work at the Tornskog tunnel (Stockholm, Sweden) included design and grouting along a 100 meter long section of one of the two tunnel tubes. Of importance to consider when doing a design and evaluating the result are: - The identification of the extent of the grouting needed based on inflow requirements and estimates of tunnel inflow before grouting. - The selection of grout and performance of grouting materials including penetration ability and length. The penetration length is important for the fan geometry design. - The ungrouted compared to the grouted and excavated rock mass conditions: estimates of tunnel inflow and (if available) measured inflows after grouting and excavation. Identify if possible explanations for deviations. For the Hallandsas, Nygard and Tornskog tunnel sections, the use of a Pareto distribution and the estimate of tunnel inflow identified a need for sealing small aperture fractures (< 50 - 100 μm) to meet the inflow requirements. The tunneling projects show that using the hydraulic aperture as a basis for selection of grout is a good

  14. Scintigraphic control of bone-fracture healing under ultrasonic stimulation: An animal experimental study

    International Nuclear Information System (INIS)

    Klug, W.; Franke, W.G.; Knoch, H.G.

    1986-01-01

    In a model of closed lower-leg fracture in rabbits and of secondary bone-fracture healing, scintigraphic control until biological healing was performed. Biological fracture healing was assumed for a region of interest (ROI)-activity ratio close to 1.0. After application of sup(99m)Tc-HEDP, 151 examinations were performed. ROI activity increased significantly until day 14 p.i. and reached the maximum value (Q=6.44) on day 14 postfracture. Sixty-one lower leg fractures were treated by ultrasound from days 14-28 postfractures. These stimulated fractures were biologically healed on day 168 postfracture. The fractures that were not treated by ultrasound could not be detected by scanning after day 203 postfracture. (orig.)

  15. Controlling radiated emissions by design

    CERN Document Server

    Mardiguian, Michel

    2014-01-01

    The 3rd edition of Controlling Radiated Emissions by Design has been updated to reflect the latest changes in the field. New to this edition is material related to technical advances, specifically super-fast data rates on wire pairs, with no increase in RF interference. Throughout the book, details are given to control RF emissions using EMC design techniques. This book retains the step-by-step approach for incorporating EMC into every new design from the ground up. It describes the selection of quieter IC technologies, their implementation into a noise-free printed circuit layout, and the gathering of these into a low emissions package. Also included is how to design an I/O filter, along with connectors and cable considerations. All guidelines are supported throughout with comprehensive calculated examples. Design engineers, EMC specialists, and technicians will benefit from learning about the development of more efficient and economical control of emissions.

  16. Flow Control Enabled Aircraft Design

    National Research Council Canada - National Science Library

    Nangia, Rajendar

    2004-01-01

    ...: Many future advanced aircraft concepts being considered by the Air Force fall outside the current aerodynamic design practice and will rely heavily on the use of flow control technology to optimize flight performance...

  17. Radiological controls integrated into design

    Energy Technology Data Exchange (ETDEWEB)

    Kindred, G.W. [Cleveland Electric Illuminating Co., Perry, OH (United States)

    1995-03-01

    Radiological controls are required by law in the design of commercial nuclear power reactor facilities. These controls can be relatively minor or significant, relative to cost. To ensure that radiological controls are designed into a project, the health physicist (radiological engineer) must be involved from the beginning. This is especially true regarding keeping costs down. For every radiological engineer at a nuclear power plant there must be fifty engineers of other disciplines. The radiological engineer cannot be an expert on every discipline of engineering. However, he must be knowledgeable to the degree of how a design will impact the facility from a radiological perspective. This paper will address how to effectively perform radiological analyses with the goal of radiological controls integrated into the design package.

  18. An Impulse Control Disorder Case with Penile Fracture and Trichotillomania

    OpenAIRE

    CUMURCU, Birgül ELBOZAN

    2014-01-01

    Penile fractures are classically described as presenting with rapid detumescence of an erection associated with blunt trauma. This clinical finding is due to a tear in the tunica albuginea surrounding the corpora cavernosum. In this study, we report and discuss a case of trichotillomania and penile bending impulse resulting in penile fracture, which was operated in the urology clinic. The possible psychological and psychiatric problems underlying the impulsive behavior are discussed, and the ...

  19. Physical processes that control droplet transport in rock fracture systems

    Science.gov (United States)

    Hay, Katrina Moran

    Aquifer recharge is generally driven by fluids that move from the Earths surface to groundwater through the unsaturated zone, also known as the vadose zone. When the vadose zone is fractured, fluids, which may include contaminants, can move through the fracture network as well as the porous matrix. Such a network of fractures can provide a more rapid path, thereby reducing contact time between the fluid and the matrix. Contact time allows for exchange of solutes between the fluid and the porous matrix, thus being able to quantify contact time is important. In addition, the behavior of fluids within a fracture network has been found to be very complex; large-scale models are yet not able to predict transport paths or flux rates. Because, small-scale flow phenomena can strongly influence the large-scale behavior of fluid movement through systems of fractures, it is important that small-scale dynamics be properly understood in order to improve our predictive capabilities in these complex systems. Relevant flow dynamics includes the impact of boundary conditions, fluid modes that evolve in time and space and transitions between modes. This thesis presents three investigations aimed at understanding the physical processes governing fluid movement in unsaturated fractures, with the ultimate goal of improving predictive relationships for fluid transport in rock fracture systems. These investigations include a theoretical analysis of the wetting of a rough surface, an experimental study of the dynamics of fluid droplets (or liquid bridges) moving in a single fracture and a theoretical analysis of the movement of a fluid droplet encountering a fracture intersection. Each investigation is motivated by environmental applications. Development of an analytical equation for the wetting of a rough surface is based on a balance between capillary forces and frictional resistive forces. The resulting equation predicts movement of the liquid invasion front driven solely by the

  20. Ergonomics and control room design

    International Nuclear Information System (INIS)

    Williams, J.C.; Story, D.T.

    1987-01-01

    The application of ergonomic principles to the design process and some aspects of the Sizewell B control room is discussed. Also outlined is the management process which ensures that these principles are applied systematically throughout the design development activity and highlights the functional requirements which must also be met in the creation of a total man-machine system package which meets all the technical design criteria. The ergonomics requirements are part of this process and extend into all aspects of design ranging from such matters as workplace organization to environmental factors, social engineering, communications and aesthetics. (author)

  1. Sedimentological and Stratigraphic Controls on Natural Fracture Distribution in Wajid Group, SW Saudi Arabia

    Science.gov (United States)

    Benaafi, Mohammed; Hariri, Mustafa; Abdullatif, Osman; Makkawi, Mohammed; Korvin, Gabor

    2016-04-01

    The Cambro-Permian Wajid Group, SW Saudi Arabia, is the main groundwater aquifer in Wadi Al-Dawasir and Najran areas. In addition, it has a reservoir potentiality for oil and natural gas in Rub' Al-Khali Basin. Wajid Group divided into four formations, ascending Dibsiyah, Sanamah, Khussyayan and Juwayl. They are mainly sandstone and exposed in an area extend from Wadi Al-Dawasir southward to Najran city and deposited within fluvial, shallow marine and glacial environments. This study aims to investigate the sedimentological and stratigraphic controls on the distribution of natural fractures within Wajid Group outcrops. A scanline sampling method was used to study the natural fracture network within Wajid Group outcrops, where the natural fractures were measured and characterized in 12 locations. Four regional natural fracture sets were observed with mean strikes of 050o, 075o, 345o, and 320o. Seven lithofacies characterized the Wajid Group at these locations and include fine-grained sandstone, coarse to pebbly sandstone, cross-bedded sandstone, massive sandstone, bioturbated sandstone, conglomerate sandstone, and conglomerate lithofacies. We found that the fine-grained and small scale cross-bedded sandstones lithofacies are characterized by high fracture intensity. In contrast, the coarse-grained sandstone and conglomerate lithofacies have low fracture intensity. Therefore, the relative fracture intensity and spacing of natural fractures within Wajid Group in the subsurface can be predicted by using the lithofacies and their depositional environments. In terms of stratigraphy, we found that the bed thickness and the stratigraphic architecture are the main controls on fractures intensity. The outcomes of this study can help to understand and predict the natural fracture distribution within the subsurface fractured sandstone hosting groundwater and hydrocarbon in Wajid and Rub' Al-Khali Basins. Hence, the finding of this study might help to explore and develop the

  2. Controlling Subsurface Fractures and Fluid Flow: A Basic Research Agenda

    Energy Technology Data Exchange (ETDEWEB)

    Pyrak-Nolte, Laura J [Purdue Univ., West Lafayette, IN (United States); DePaolo, Donald J. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Univ. of California, Berkeley, CA (United States); Pietraß, Tanja [USDOE Office of Science, Washington, DC (United States)

    2015-05-22

    From beneath the surface of the earth, we currently obtain about 80-percent of the energy our nation consumes each year. In the future we have the potential to generate billions of watts of electrical power from clean, green, geothermal energy sources. Our planet’s subsurface can also serve as a reservoir for storing energy produced from intermittent sources such as wind and solar, and it could provide safe, long-term storage of excess carbon dioxide, energy waste products and other hazardous materials. However, it is impossible to underestimate the complexities of the subsurface world. These complexities challenge our ability to acquire the scientific knowledge needed for the efficient and safe exploitation of its resources. To more effectively harness subsurface resources while mitigating the impacts of developing and using these resources, the U.S. Department of Energy established SubTER – the Subsurface Technology and Engineering RD&D Crosscut team. This DOE multi-office team engaged scientists and engineers from the national laboratories to assess and make recommendations for improving energy-related subsurface engineering. The SubTER team produced a plan with the overall objective of “adaptive control of subsurface fractures and fluid flow.”This plan revolved around four core technological pillars—Intelligent Wellbore Systems that sustain the integrity of the wellbore environment; Subsurface Stress and Induced Seismicity programs that guide and optimize sustainable energy strategies while reducing the risks associated with subsurface injections; Permeability Manipulation studies that improve methods of enhancing, impeding and eliminating fluid flow; and New Subsurface Signals that transform our ability to see into and characterize subsurface systems. The SubTER team developed an extensive R&D plan for advancing technologies within these four core pillars and also identified several areas where new technologies would require additional basic research

  3. Acoustic Monitoring of Gravity-Driven Controls on CaCO3 Precipitates in a Fracture

    Science.gov (United States)

    Xu, Z.; Sheets, J.; Zhang, L.; Kim, D.; Kneafsey, T. J.; Cole, D. R.; Jun, Y. S.; Pyrak-Nolte, L. J.

    2017-12-01

    the orientation thus affecting the ability of a fracture to self-heal if oriented vertically. This work was supported by the Center for Nanoscale Controls on Geologic CO (NCGC), an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Basic Energy Sciences under Award # DE-AC02-05CH11231

  4. Robust control design with MATLAB

    CERN Document Server

    Gu, Da-Wei; Konstantinov, Mihail M

    2013-01-01

    Robust Control Design with MATLAB® (second edition) helps the student to learn how to use well-developed advanced robust control design methods in practical cases. To this end, several realistic control design examples from teaching-laboratory experiments, such as a two-wheeled, self-balancing robot, to complex systems like a flexible-link manipulator are given detailed presentation. All of these exercises are conducted using MATLAB® Robust Control Toolbox 3, Control System Toolbox and Simulink®. By sharing their experiences in industrial cases with minimum recourse to complicated theories and formulae, the authors convey essential ideas and useful insights into robust industrial control systems design using major H-infinity optimization and related methods allowing readers quickly to move on with their own challenges. The hands-on tutorial style of this text rests on an abundance of examples and features for the second edition: ·        rewritten and simplified presentation of theoretical and meth...

  5. ISABELLE control system: design concepts

    International Nuclear Information System (INIS)

    Humphrey, J.W.

    1979-01-01

    ISABELLE is a Department of Energy funded proton accelerator/storage ring being built at Brookhaven National Laboratory (Upton, Long Island, New York). It is large (3.8 km circumference) and complicated (approx. 30,000 monitor and control variables). It is based on superconducting technology. Following the example of previous accelerators, ISABELLE will be operated from a single control center. The control system will be distributed and will incorporate a local computer network. An overview of the conceptual design of the ISABELLE control system will be presented

  6. Spacecraft Design Thermal Control Subsystem

    Science.gov (United States)

    Miyake, Robert N.

    2008-01-01

    The Thermal Control Subsystem engineers task is to maintain the temperature of all spacecraft components, subsystems, and the total flight system within specified limits for all flight modes from launch to end-of-mission. In some cases, specific stability and gradient temperature limits will be imposed on flight system elements. The Thermal Control Subsystem of "normal" flight systems, the mass, power, control, and sensing systems mass and power requirements are below 10% of the total flight system resources. In general the thermal control subsystem engineer is involved in all other flight subsystem designs.

  7. Vitamin D and Fracture Risk in Early Childhood: A Case-Control Study

    Science.gov (United States)

    Anderson, Laura N.; Heong, Sze Wing; Chen, Yang; Thorpe, Kevin E.; Adeli, Khosrow; Howard, Andrew; Sochett, Etienne; Birken, Catherine S.; Parkin, Patricia C.; Maguire, Jonathon L.; Abdullah, Kawsari; Anderson, Laura N.; Birken, Catherine S.; Borkhoff, Cornelia M.; Carsley, Sarah; Chen, Yang; Katz-Lavigne, Mikael; Kavikondala, Kanthi; Kowal, Christine; Maguire, Jonathon L.; Mason, Dalah; Omand, Jessica; Parkin, Patricia C.; Persaud, Navindra; van den Heuvel, Meta; Baker, Jillian; Barozzino, Tony; Bonifacio, Joey; Campbell, Douglas; Cheema, Sohail; Chisamore, Brian; Danayan, Karoon; Das, Paul; Derocher, Mary Beth; Do, Anh; Dorey, Michael; Freeman, Sloane; Fung, Keewai; Guiang, Charlie; Handford, Curtis; Hatch, Hailey; Jacobson, Sheila; Kiran, Tara; Knowles, Holly; Kwok, Bruce; Lakhoo, Sheila; Lam-Antoniades, Margarita; Lau, Eddy; Leung, Fok-Han; Loo, Jennifer; Mahmoud, Sarah; Moodie, Rosemary; Morinis, Julia; Naymark, Sharon; Neelands, Patricia; Owen, James; Peer, Michael; Perlmutar, Marty; Persaud, Navindra; Pinto, Andrew; Porepa, Michelle; Ramji, Nasreen; Ramji, Noor; Rosenthal, Alana; Saunderson, Janet; Saxena, Rahul; Sgro, Michael; Shepherd, Susan; Smiltnieks, Barbara; Taylor, Carolyn; Weisdors, Thea; Wijayasinghe, Sheila; Wong, Peter; Ying, Ethel; Young, Elizabeth

    2017-01-01

    Abstract The objective of this study was to evaluate the association of vitamin D intake and serum levels with fracture risk in children under 6 years of age. A case-control study was conducted in Toronto, Ontario, Canada. Cases were recruited from the fracture clinic at the Hospital for Sick Children, and matched controls were obtained from the TARGet Kids! primary-care research network. Controls were matched to cases on age, sex, height, and season. Fracture risk was estimated from conditional logistic regression, with adjustment for skin type, fracture history, waist circumference, outdoor free play, neighborhood income, soda consumption, and child's birth weight. A total of 206 cases were recruited during May 2009–April 2013 and matched to 343 controls. Serum 25-hydroxyvitamin D concentration (per 10-nmol/L increment: adjusted odds ratio (aOR) = 0.95, 95% confidence interval (CI): 0.88, 1.03) and intake of cow's milk (2 cups/day vs. 2 cups/day: aOR = 1.39 (95% CI: 0.85, 2.23)) were not significantly associated with reduced odds of fracture. A statistically significant association was observed between child use of vitamin D supplements and decreased odds of fracture (yes vs. no: aOR = 0.42, 95% CI: 0.25, 0.69). Vitamin D supplementation, but not serum 25-hydroxyvitamin D level or milk intake, was associated with reduced fracture risk among these healthy young children. PMID:28459987

  8. Validation of a fracture mechanics approach to nuclear transportation cask design through a drop test program

    International Nuclear Information System (INIS)

    Sorenson, K.B.

    1986-01-01

    Sandia National Laboratories (SNL), under contract to the Department of Energy, is conducting a research program to develop and validate a fracture mechanics approach to cask design. A series of drop tests of a transportation cask is planned for the summer of 1986 as the method for benchmarking and, thereby, validating the fracture mechanics approach. This paper presents the drop test plan and background leading to the development of the test plan including structural analyses, material characterization, and non-destructive evaluation (NDE) techniques necessary for defining the test plan properly

  9. Reducing the environmental impact of hydraulic fracturing through design optimisation of positive displacement pumps

    International Nuclear Information System (INIS)

    Josifovic, Aleksandar; Roberts, Jennifer J.; Corney, Jonathan; Davies, Bruce; Shipton, Zoe K.

    2016-01-01

    The current approach to hydraulic fracturing requires large amounts of industrial hardware to be transported, installed and operated in temporary locations. A significant proportion of this equipment is comprised of the fleet of pumps required to provide the high pressures and flows necessary for well stimulation. Studies have shown that over 90% of the emissions of CO_2 and other pollutants that occur during a hydraulic fracturing operation are associated with these pumps. Pollution and transport concerns are of paramount importance for the emerging hydraulic fracturing industry in Europe, and so it is timely to consider these factors when assessing the design of high pressure pumps for the European resources. This paper gives an overview of the industrial plant required to carry out a hydraulic fracturing operation. This is followed by an analysis of the pump's design space that could result in improved pump efficiency. We find that reducing the plunger diameter and running the pump at higher speeds can increase the overall pump efficiency by up to 4.6%. Such changes to the pump's parameters would results in several environmental benefits beyond the obvious economic gains of lower fuel consumption. The paper concludes with a case study that quantifies these benefits. - Highlights: • We develop a parameterized model of hydraulic fracturing pumps. • We explore performance variation to optimise pump efficiency and performance. • New design could increase pump energy efficiency up to 4.6% and improve reliability. • The new design could also reduce environmental and social impacts of pumping. • This illustrates how optimised mechanical design can lower impacts and cost.

  10. Evaluation of the Fracture Resistance of Computer‑aided Design ...

    African Journals Online (AJOL)

    2018-04-04

    Apr 4, 2018 ... unrestored teeth were kept and tested as a control group. A universal test ... manufacturing. (CAD/CAM) materials undergo resolving the risk of void ... manufacturing monolithic crowns prepared in different cement thicknesses.

  11. Topological design of all-ceramic dental bridges for enhancing fracture resistance.

    Science.gov (United States)

    Zhang, Zhongpu; Chen, Junning; Li, Eric; Li, Wei; Swain, Michael; Li, Qing

    2016-06-01

    Layered all-ceramic systems have been increasingly adopted in major dental prostheses. However, ceramics are inherently brittle, and they often subject to premature failure under high occlusion forces especially in the posterior region. This study aimed to develop mechanically sound novel topological designs for all-ceramic dental bridges by minimizing the fracture incidence under given loading conditions. A bi-directional evolutionary structural optimization (BESO) technique is implemented within the extended finite element method (XFEM) framework. Extended finite element method allows modeling crack initiation and propagation inside all-ceramic restoration systems. Following this, BESO searches the optimum distribution of two different ceramic materials, namely porcelain and zirconia, for minimizing fracture incidence. A performance index, as per a ratio of peak tensile stress to material strength, is used as a design objective. In this study, the novel XFEM based BESO topology optimization significantly improved structural strength by minimizing performance index for suppressing fracture incidence in the structures. As expected, the fracture resistance and factor of safety of fixed partial dentures structure increased upon redistributing zirconia and porcelain in the optimal topological configuration. Dental CAD/CAM systems and the emerging 3D printing technology were commercially available to facilitate implementation of such a computational design, exhibiting considerable potential for clinical application in the future. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

  12. Bioremediation in fractured rock: 1. Modeling to inform design, monitoring, and expectations

    Science.gov (United States)

    Tiedeman, Claire; Shapiro, Allen M.; Hsieh, Paul A.; Imbrigiotta, Thomas; Goode, Daniel J.; Lacombe, Pierre; DeFlaun, Mary F.; Drew, Scott R.; Johnson, Carole D.; Williams, John H.; Curtis, Gary P.

    2018-01-01

    Field characterization of a trichloroethene (TCE) source area in fractured mudstones produced a detailed understanding of the geology, contaminant distribution in fractures and the rock matrix, and hydraulic and transport properties. Groundwater flow and chemical transport modeling that synthesized the field characterization information proved critical for designing bioremediation of the source area. The planned bioremediation involved injecting emulsified vegetable oil and bacteria to enhance the naturally occurring biodegradation of TCE. The flow and transport modeling showed that injection will spread amendments widely over a zone of lower‐permeability fractures, with long residence times expected because of small velocities after injection and sorption of emulsified vegetable oil onto solids. Amendments transported out of this zone will be diluted by groundwater flux from other areas, limiting bioremediation effectiveness downgradient. At nearby pumping wells, further dilution is expected to make bioremediation effects undetectable in the pumped water. The results emphasize that in fracture‐dominated flow regimes, the extent of injected amendments cannot be conceptualized using simple homogeneous models of groundwater flow commonly adopted to design injections in unconsolidated porous media (e.g., radial diverging or dipole flow regimes). Instead, it is important to synthesize site characterization information using a groundwater flow model that includes discrete features representing high‐ and low‐permeability fractures. This type of model accounts for the highly heterogeneous hydraulic conductivity and groundwater fluxes in fractured‐rock aquifers, and facilitates designing injection strategies that target specific volumes of the aquifer and maximize the distribution of amendments over these volumes.

  13. Report About the Design of External Fixator for Treatment of Pelvis and Acetabulum Fractures

    Directory of Open Access Journals (Sweden)

    Martin JANEČKA

    2012-06-01

    Full Text Available Main point in this contribution is the design of external fixators applied in traumatology and orthopaedics. These fixators can be used in the treatment of open and unstable (i.e. complicated fractures of pelvis and its acetabulum. Numerical modelling (i.e. Finite Element Method, together with CAD modelling, experiments, material engineering, and nanotechnology are presented as a support for developing of a new design of external fixators.

  14. Numerical examination of the factors controlling DNAPL migration through a single fracture.

    Science.gov (United States)

    Reynolds, D A; Kueper, B H

    2002-01-01

    The migration of five dense nonaqueous phase liquids (DNAPLs) through a single fracture in a clay aquitard was numerically simulated with the use of a compositional simulator. The effects of fracture aperture, fracture dip, matrix porosity, and matrix organic carbon content on the migration of chlorobenzene, 1,2-dichloroethylene, trichloroethylene, tetra-chloroethylene, and 1,2-dibromoethane were examined. Boundary conditions were chosen such that DNAPL entry into the system was allowed to vary according to the stresses applied. The aperture is the most important factor of those studied controlling the migration rate of DNAPL through a single fracture embedded in a clay matrix. Loss of mass to the matrix through diffusion does not significantly retard the migration rate of the DNAPL, particularly in larger aperture fractures (e.g., 50 microm). With time, the ratio of diffusive loss to the matrix to DNAPL flux into the fracture approaches an asymptotic value lower than unity. The implication is that matrix diffusion cannot arrest the migration of DNAPL in a single fracture. The complex relationships between density, viscosity, and solubility that, to some extent, govern the migration of DNAPL through these systems prevent accurate predictions without the use of numerical models. The contamination potential of the migrating DNAPL is significantly increased through the transfer of mass to the matrix. The occurrence of opposite concentration gradients within the matrix can cause dissolved phase contamination to exist in the system for more than 1000 years after the DNAPL has been completely removed from the fracture.

  15. Bone Morphogenetic Protein for the Healing of Tibial Fracture: A Meta-Analysis of Randomized Controlled Trials.

    Directory of Open Access Journals (Sweden)

    Jiezhi Dai

    Full Text Available To review the evidence from RCTs on clinical outcomes and benefit of acute tibial fracture and nonunion treated with and without BMPs.We searched multiple databases (MEDLINE, EMABSE, BIOSIS and Cochrane central as well as reference lists of articles and contacted authors. Evaluated outcomes included union rate, revision rate, hardware failure and infection. The weighted and standard mean difference (WMD and SMD or the relative risk (RR was calculated for continuous or dichotomous data respectively. The quality of the trial was assessed, and meta-analyses were performed with the Cochrane Collaboration's REVMAN 5.0 software.Eight RCTs involving 1113 patients were included. For acute tibial fracture, BMP group was associated with a higher rate of union (RR, 1.16; 95% CI, 1.04 to 1.30 and a lower rate of revision (RR, 0.68; 95% CI, 0.54 to 0.85 compared with control group. No significant differences were found in rate of hardware failure and infection. The pooled RR for achieving union for tibial fracture nonunion was 0.98 (95% CI, 0.86 to 1.13. There was no significant difference between the two groups in the rate of revision (RR, 0.48; 95% CI, 0.13 to 1.85 and infection (RR, 0.61; 95% CI, 0.37 to 1.02.Study on acute tibial fractures suggests that BMP is more effective that controls, for bone union and for decreasing the rate of surgical revision to achieve union. For the treatment of tibial fracture nonunion, BMP leads to similar results to as autogenous bone grafting. Finally, well-designed RCTs of BMP for tibial fracture treatment are also needed.

  16. Optimizing the design of vertical seismic profiling (VSP) for imaging fracture zones over hardrock basement geothermal environments

    Science.gov (United States)

    Reiser, Fabienne; Schmelzbach, Cedric; Maurer, Hansruedi; Greenhalgh, Stewart; Hellwig, Olaf

    2017-04-01

    A primary focus of geothermal seismic imaging is to map dipping faults and fracture zones that control rock permeability and fluid flow. Vertical seismic profiling (VSP) is therefore a most valuable means to image the immediate surroundings of an existing borehole to guide, for example, the placing of new boreholes to optimize production from known faults and fractures. We simulated 2D and 3D acoustic synthetic seismic data and processed it through to pre-stack depth migration to optimize VSP survey layouts for mapping moderately to steeply dipping fracture zones within possible basement geothermal reservoirs. Our VSP survey optimization procedure for sequentially selecting source locations to define the area where source points are best located for optimal imaging makes use of a cross-correlation statistic, by which a subset of migrated shot gathers is compared with a target or reference image from a comprehensive set of source gathers. In geothermal exploration at established sites, it is reasonable to assume that sufficient à priori information is available to construct such a target image. We generally obtained good results with a relatively small number of optimally chosen source positions distributed over an ideal source location area for different fracture zone scenarios (different dips, azimuths, and distances from the surveying borehole). Adding further sources outside the optimal source area did not necessarily improve the results, but rather resulted in image distortions. It was found that fracture zones located at borehole-receiver depths and laterally offset from the borehole by 300 m can be imaged reliably for a range of the different dips, but more source positions and large offsets between sources and the borehole are required for imaging steeply dipping interfaces. When such features cross-cut the borehole, they are particularly difficult to image. For fracture zones with different azimuths, 3D effects are observed. Far offset source positions

  17. Comparison of Chamfer and Deep Chamfer Preparation Designs on the Fracture Resistance of Zirconia Core Restorations

    Directory of Open Access Journals (Sweden)

    Ezatollah Jalalian

    2011-06-01

    Full Text Available Background and aims. One of the major problems of all-ceramic restorations is their probable fracture under occlusal force. The aim of the present in vitro study was to compare the effect of two marginal designs (chamfer and deep chamfer on the fracture resistance of all-ceramic restorations, CERCON. Materials and methods. This in vitro study was carried out with single-blind experimental technique. One stainless steel die with 50’ chamfer finish line design (0.8 mm deep was prepared using a milling machine. Ten epoxy resin dies were prepared. The same die was retrieved and 50' chamfer was converted into a deep chamfer design (1 mm. Again ten epoxy resin dies were prepared from the deep chamfer die. Zirconia cores with 0.4 mm thickness and 35 µm cement space were fabricated on the epoxy resin dies (10 chamfer and 10 deep chamfer samples. The zirconia cores were cemented on the epoxy resin dies and underwent a fracture test with a universal testing machine and the samples were investigated from the point of view of the origin of the failure. Results. The mean values of fracture resistance for deep chamfer and chamfer samples were 1426.10±182.60 and 991.75±112.00 N, respectively. Student’s t-test revealed statistically significant differences between the groups. Conclusion. The results indicated a relationship between the marginal design of zirconia cores and their fracture resistance. A deep chamfer margin improved the biomechanical performance of posterior single zirconia crown restorations, which might be attributed to greater thickness and rounded internal angles in deep chamfer margins.

  18. Cockpit control system conceptual design

    Science.gov (United States)

    Meholic, Greg; Brown, Rhonda; Hall, Melissa; Harvey, Robert; Singer, Michael; Tella, Gustavo

    1993-01-01

    The purpose of this project was to provide a means for operating the ailerons, elevator, elevator trim, rudder, nosewheel steering, and brakes in the Triton primary flight trainer. The main design goals under consideration were to illustrate system and subsystem integration, control function ability, and producibility. Weight and maintenance goals were addressed.

  19. A computer-controlled automated test system for fatigue and fracture testing

    International Nuclear Information System (INIS)

    Nanstad, R.K.; Alexander, D.J.; Swain, R.L.; Hutton, J.T.; Thomas, D.L.

    1989-01-01

    A computer-controlled system consisting of a servohydraulic test machine, an in-house designed test controller, and a desktop computer has been developed for performing automated fracture toughness and fatigue crack growth testing both in the laboratory and in hot cells for remote testing of irradiated specimens. Both unloading compliance and dc-potential drop can be used to monitor crack growth. The test controller includes a dc-current supply programmer, a function generator for driving the servohydraulic test machine to required test outputs, five measurement channels (each consisting of low-pass filter, track/hold amplifier, and 16-bit analog-to-digital converter), and digital logic for various control and data multiplexing functions. The test controller connects to the computer via a 16-bit wide photo-isolated bidirectional bus. The computer, a Hewlett-Packard series 200/300, inputs specimen and test parameters from the operator, configures the test controller, stores test data from the test controller in memory, does preliminary analysis during the test, and records sensor calibrations, specimen and test parameters, and test data on flexible diskette for later recall and analysis with measured initial and final crack length information. During the test, the operator can change test parameters as necessary. 24 refs., 6 figs

  20. Effects of a training program after surgically treated ankle fracture: a prospective randomised controlled trial

    Directory of Open Access Journals (Sweden)

    Ekdahl Charlotte S

    2009-09-01

    Full Text Available Abstract Background Despite conflicting results after surgically treated ankle fractures few studies have evaluated the effects of different types of training programs performed after plaster removal. The aim of this study was to evaluate the effects of a 12-week standardised but individually suited training program (training group versus usual care (control group after plaster removal in adults with surgically treated ankle fractures. Methods In total, 110 men and women, 18-64 years of age, with surgically treated ankle fracture were included and randomised to either a 12-week training program or to a control group. Six and twelve months after the injury the subjects were examined by the same physiotherapist who was blinded to the treatment group. The main outcome measure was the Olerud-Molander Ankle Score (OMAS which rates symptoms and subjectively scored function. Secondary outcome measures were: quality of life (SF-36, timed walking tests, ankle mobility tests, muscle strength tests and radiological status. Results 52 patients were randomised to the training group and 58 to the control group. Five patients dropped out before the six-month follow-up resulting in 50 patients in the training group and 55 in the control group. Nine patients dropped out between the six- and twelve-month follow-up resulting in 48 patients in both groups. When analysing the results in a mixed model analysis on repeated measures including interaction between age-group and treatment effect the training group demonstrated significantly improved results compared to the control group in subjects younger than 40 years of age regarding OMAS (p = 0.028, muscle strength in the plantar flexors (p = 0.029 and dorsiflexors (p = 0.030. Conclusion The results of this study suggest that when adjusting for interaction between age-group and treatment effect the training model employed in this study was superior to usual care in patients under the age of 40. However, as only three

  1. Design of reconfigurable logic controllers

    CERN Document Server

    Bukowiec, Arkadiusz; Doligalski, Michał; Tkacz, Jacek

    2016-01-01

    This book presents the original concepts and modern techniques for specification, synthesis, optimisation and implementation of parallel logical control devices. It deals with essential problems of reconfigurable control systems like dependability, modularity and portability. Reconfigurable systems require a wider variety of design and verification options than the application-specific integrated circuits. The book presents a comprehensive selection of possible design techniques. The diversity of the modelling approaches covers Petri nets, state machines and activity diagrams. The preferences of the presented optimization and synthesis methods are not limited to increasing of the efficiency of resource use. One of the biggest advantages of the presented methods is the platform independence, the FPGA devices and single board computers are some of the examples of possible platforms. These issues and problems are illustrated with practical cases of complete control systems. If you expect a new look at the recon...

  2. An optimal design of cluster spacing intervals for staged fracturing in horizontal shale gas wells based on the optimal SRVs

    Directory of Open Access Journals (Sweden)

    Lan Ren

    2017-09-01

    Full Text Available When horizontal well staged cluster fracturing is applied in shale gas reservoirs, the cluster spacing is essential to fracturing performance. If the cluster spacing is too small, the stimulated area between major fractures will be overlapped, and the efficiency of fracturing stimulation will be decreased. If the cluster spacing is too large, the area between major fractures cannot be stimulated completely and reservoir recovery extent will be adversely impacted. At present, cluster spacing design is mainly based on the static model with the potential reservoir stimulation area as the target, and there is no cluster spacing design method in accordance with the actual fracturing process and targets dynamic stimulated reservoir volume (SRV. In this paper, a dynamic SRV calculation model for cluster fracture propagation was established by analyzing the coupling mechanisms among fracture propagation, fracturing fluid loss and stress. Then, the cluster spacing was optimized to reach the target of the optimal SRVs. This model was applied for validation on site in the Jiaoshiba shale gasfield in the Fuling area of the Sichuan Basin. The key geological engineering parameters influencing the optimal cluster spacing intervals were analyzed. The reference charts for the optimal cluster spacing design were prepared based on the geological characteristics of south and north blocks in the Jiaoshiba shale gasfield. It is concluded that the cluster spacing optimal design method proposed in this paper is of great significance in overcoming the blindness in current cluster perforation design and guiding the optimal design of volume fracturing in shale gas reservoirs. Keywords: Shale gas, Horizontal well, Staged fracturing, Cluster spacing, Reservoir, Stimulated reservoir volume (SRV, Mathematical model, Optimal method, Sichuan basin, Jiaoshiba shale gasfield

  3. Major factors controlling fracture development in the Middle Permian Lucaogou Formation tight oil reservoir, Junggar Basin, NW China

    Science.gov (United States)

    Zhang, Chen; Zhu, Deyu; Luo, Qun; Liu, Luofu; Liu, Dongdong; Yan, Lin; Zhang, Yunzhao

    2017-09-01

    Natural fractures in seven wells from the Middle Permian Lucaogou Formation in the Junggar Basin were evaluated in light of regional structural evolution, tight reservoir geochemistry (including TOC and mineral composition), carbon and oxygen isotopes of calcite-filled fractures, and acoustic emission (AE). Factors controlling the development of natural fractures were analyzed using qualitative and/or semi-quantitative techniques, with results showing that tectonic factors are the primary control on fracture development in the Middle Permian Lucaogou Formation of the Junggar Basin. Analyses of calcite, dolomite, and TOC show positive correlations with the number of fractures, while deltaic lithofacies appear to be the most favorable for fracture development. Mineral content was found to be a major control on tectonic fracture development, while TOC content and sedimentary facies mainly control bedding fractures. Carbon and oxygen isotopes vary greatly in calcite-filled fractures (δ13C ranges from 0.87‰ to 7.98‰, while δ18O ranges from -12.63‰ to -5.65‰), indicating that fracture development increases with intensified tectonic activity or enhanced diagenetic alteration. By analyzing the cross-cutting relationships of fractures in core, as well as four Kaiser Effect points in the acoustic emission curve, we observed four stages of tectonic fracture development. First-stage fractures are extensional, and were generated in the late Triassic, with calcite fracture fills formed between 36.51 °C and 56.89 °C. Second-stage fractures are shear fractures caused by extrusion stress from the southwest to the northeast, generated by the rapid uplift of the Tianshan in the Middle and Late Jurassic; calcite fracture fills formed between 62.91 °C and 69.88 °C. Third-stage fractures are NNW-trending shear fractures that resulted from north-south extrusion and thrusting in a foreland depression along the front of the Early Cretaceous Bogda Mountains. Calcite fracture

  4. Computer-aided, single-specimen controlled bending test for fracture-kinetics measurement in ceramics

    International Nuclear Information System (INIS)

    Borovik, V.G.; Chushko, V.M.; Kovalev, S.P.

    1995-01-01

    Fracture testing of ceramics by using controlled crack growth is proposed to allow study of crack-kinetics behavior under a given loading history. A computer-aided, real-time data acquisition system improves the quality of crack-growth parameters obtained in a simple, single-specimen bend test. Several ceramic materials were tested in the present study: aluminum nitride as a linear-elastic material; and alumina and yttria-stabilized zirconia, both representative of ceramics with microstructure-dependent nonlinear fracture properties. Ambiguities in the crack-growth diagrams are discussed to show the importance of accounting for crack-growth history in correctly describing nonequilibrium fracture behavior

  5. Vision-based real-time position control of a semi-automated system for robot-assisted joint fracture surgery.

    Science.gov (United States)

    Dagnino, Giulio; Georgilas, Ioannis; Tarassoli, Payam; Atkins, Roger; Dogramadzi, Sanja

    2016-03-01

    Joint fracture surgery quality can be improved by robotic system with high-accuracy and high-repeatability fracture fragment manipulation. A new real-time vision-based system for fragment manipulation during robot-assisted fracture surgery was developed and tested. The control strategy was accomplished by merging fast open-loop control with vision-based control. This two-phase process is designed to eliminate the open-loop positioning errors by closing the control loop using visual feedback provided by an optical tracking system. Evaluation of the control system accuracy was performed using robot positioning trials, and fracture reduction accuracy was tested in trials on ex vivo porcine model. The system resulted in high fracture reduction reliability with a reduction accuracy of 0.09 mm (translations) and of [Formula: see text] (rotations), maximum observed errors in the order of 0.12 mm (translations) and of [Formula: see text] (rotations), and a reduction repeatability of 0.02 mm and [Formula: see text]. The proposed vision-based system was shown to be effective and suitable for real joint fracture surgical procedures, contributing a potential improvement of their quality.

  6. [Distortion and vertical fracture of the root: effect produced by condenser design].

    Science.gov (United States)

    Dang, D A; Walton, R E

    1990-01-01

    The incidence of vertical root fractures and the amount of root distortion created during lateral condensation of gutta-percha with either D11 spreaders or B-finger pluggers were evaluated in vitro. Fifty-five extracted human, single-rooted teeth were instrumented using the step-back flare technique. Ten teeth served as positive controls (obturation to the point of fracture) and five teeth as negative controls (prepared but not obtured). Strain gauges were attached to the root surfaces. In the experimental group, 20 teeth were obturated using a D11 spreader and 20 with a B-finger plugger. Recordings were made of root distortion (expansion) created during obturation. Then, after sectioning the teeth, root surfaces of obturated samples were examined for fractures under the scanning electron microscope. Only the more tapered spreader, the D11, produces vertical root fractures, although very few in number. Also, the D11 spreader caused greater root distortion than did the B-finger plugger.

  7. Considerations of the manner of accounting for fast fracture risk in the design of PWR vessels

    International Nuclear Information System (INIS)

    Pellissier-Tanon, A.; Grandemange, J.M.

    1986-01-01

    The French approach to the prevention of fast fracture in PWR vessels is to consider it as a whole and to choose the most convenient way to meet this general goal from an economic and technical point of view. According to this approach, there are no specific limits imposed on such factors as end of life RTsub(NDT) or neutron fluence, which are taken as criteria in other countries. The RCCM design and construction code specifications on chemical content and RTsub(NDT) for beltline and non-irradiated parts establish a sound basis for safety. However, for the most critical parts, the existence of large margins with respect to fast fracture is demonstrated by analysis for all second, third and fourth category design transients. To this aim, the RCCM code needs to demonstrate specified safety margins, depending on the transient category, for reference defects defined in kind and size, in order to bound realistically any defects which have a chance of occurring in the part during manufacture. This approach, which enables the disclosure of the influence of all significant design factors on fracture risk, ensures the most consistent way to improve design safety. (author)

  8. Considerations of the manner of accounting for fast fracture risk in the design of PWR vessels

    Energy Technology Data Exchange (ETDEWEB)

    1986-01-01

    The French approach to the prevention of fast fracture in PWR vessels is to consider it as a whole and to choose the most convenient way to meet this general goal from an economic and technical point of view. According to this approach, there are no specific limits imposed on such factors as end of life RTsub(NDT) or neutron fluence, which are taken as criteria in other countries. The RCCM design and construction code specifications on chemical content and RTsub(NDT) for beltline and non-irradiated parts establish a sound basis for safety. However, for the most critical parts, the existence of large margins with respect to fast fracture is demonstrated by analysis for all second, third and fourth category design transients. To this aim, the RCCM code needs to demonstrate specified safety margins, depending on the transient category, for reference defects defined in kind and size, in order to bound realistically any defects which have a chance of occurring in the part during manufacture. This approach, which enables the disclosure of the influence of all significant design factors on fracture risk, ensures the most consistent way to improve design safety.

  9. Nurse case-manager vs multifaceted intervention to improve quality of osteoporosis care after wrist fracture: randomized controlled pilot study.

    Science.gov (United States)

    Majumdar, S R; Johnson, J A; Bellerose, D; McAlister, F A; Russell, A S; Hanley, D A; Garg, S; Lier, D A; Maksymowych, W P; Morrish, D W; Rowe, B H

    2011-01-01

    Few outpatients with fractures are treated for osteoporosis in the years following fracture. In a randomized pilot study, we found a nurse case-manager could double rates of osteoporosis testing and treatment compared with a proven efficacious quality improvement strategy directed at patients and physicians (57% vs 28% rates of appropriate care). Few patients with fractures are treated for osteoporosis. An intervention directed at wrist fracture patients (education) and physicians (guidelines, reminders) tripled osteoporosis treatment rates compared to controls (22% vs 7% within 6 months of fracture). More effective strategies are needed. We undertook a pilot study that compared a nurse case-manager to the multifaceted intervention using a randomized trial design. The case-manager counseled patients, arranged bone mineral density (BMD) tests, and prescribed treatments. We included controls from our first trial who remained untreated for osteoporosis 1-year post-fracture. Primary outcome was bisphosphonate treatment and secondary outcomes were BMD testing, appropriate care (BMD test-treatment if bone mass low), and costs. Forty six patients untreated 1-year after wrist fracture were randomized to case-manager (n = 21) or multifaceted intervention (n = 25). Median age was 60 years and 68% were female. Six months post-randomization, 9 (43%) case-managed patients were treated with bisphosphonates compared with 3 (12%) multifaceted intervention patients (relative risk [RR] 3.6, 95% confidence intervals [CI] 1.1-11.5, p = 0.019). Case-managed patients were more likely than multifaceted intervention patients to undergo BMD tests (81% vs 52%, RR 1.6, 95%CI 1.1-2.4, p = 0.042) and receive appropriate care (57% vs 28%, RR 2.0, 95%CI 1.0-4.2, p = 0.048). Case-management cost was $44 (CDN) per patient vs $12 for the multifaceted intervention. A nurse case-manager substantially increased rates of appropriate testing and treatment for osteoporosis in

  10. Serum vitamin E concentrations among highly functioning hip fracture patients are higher than in nonfracture controls.

    Science.gov (United States)

    D'Adamo, Christopher R; Shardell, Michelle D; Hicks, Gregory E; Orwig, Denise L; Hochberg, Marc C; Semba, Richard D; Yu-Yahiro, Janet A; Ferrucci, Luigi; Magaziner, Jay S; Miller, Ram R

    2011-03-01

    Malnutrition after hip fracture is common and associated with poor outcomes and protracted recovery. Low concentrations of vitamin E have been associated with incident decline in physical function among older adults and may, therefore, be particularly important to functionally compromised patients hip fracture patients. Serum concentrations of α-tocopherol and γ-tocopherol, the 2 major forms of vitamin E, were assessed in 148 female hip fracture patients 65 years or older from the Baltimore Hip Studies cohort 4 around the time of fracture (baseline) and at 2, 6, and 12 month postfracture follow-up visits (recovery). It was hypothesized that mean concentrations of both forms of vitamin E among these hip fracture patients would be lowest at the baseline visit and increase at each study visit during the year after fracture. Linear regression and generalized estimating equations were used to assess changes in vitamin E concentrations after adjustment for covariates and to determine predictors of vitamin E concentrations at baseline and throughout recovery. It was also hypothesized that vitamin E concentrations shortly after hip fracture would be lower than those in nonfracture controls after adjustment for covariates. To evaluate this hypothesis, linear regression was used to perform adjusted comparisons of baseline vitamin E concentrations among Baltimore Hip Studies cohort 4 participants to 1076 older women without history of hip fracture from the Women's Health and Aging Study I, Invecchiare in Chianti Study, and the National Health and Nutrition Examination Surveys. Mean α-tocopherol was lowest at baseline, and time from fracture to blood draw was positively associated with baseline α-tocopherol (P = .005). Mean γ-tocopherol did not change appreciably throughout the year after fracture, although it fluctuated widely within individuals. Serum concentrations of α-tocopherol and γ-tocopherol were highest among the hip fracture population after adjustment (P hip

  11. Fracture mechanics based design for radioactive material transport packagings -- Historical review

    International Nuclear Information System (INIS)

    Smith, J.A.; Salzbrenner, D.; Sorenson, K.; McConnell, P.

    1998-04-01

    The use of a fracture mechanics based design for the radioactive material transport (RAM) packagings has been the subject of extensive research for more than a decade. Sandia National Laboratories (SNL) has played an important role in the research and development of the application of this technology. Ductile iron has been internationally accepted as an exemplary material for the demonstration of a fracture mechanics based method of RAM packaging design and therefore is the subject of a large portion of the research discussed in this report. SNL's extensive research and development program, funded primarily by the U. S. Department of Energy's Office of Transportation, Energy Management and Analytical Services (EM-76) and in an auxiliary capacity, the office of Civilian Radioactive Waste Management, is summarized in this document along with a summary of the research conducted at other institutions throughout the world. In addition to the research and development work, code and standards development and regulatory positions are also discussed

  12. Evidence for tectonic, lithologic, and thermal controls on fracture system geometries in an andesitic high-temperature geothermal field

    Science.gov (United States)

    Massiot, Cécile; Nicol, Andrew; McNamara, David D.; Townend, John

    2017-08-01

    Analysis of fracture orientation, spacing, and thickness from acoustic borehole televiewer (BHTV) logs and cores in the andesite-hosted Rotokawa geothermal reservoir (New Zealand) highlights potential controls on the geometry of the fracture system. Cluster analysis of fracture orientations indicates four fracture sets. Probability distributions of fracture spacing and thickness measured on BHTV logs are estimated for each fracture set, using maximum likelihood estimations applied to truncated size distributions to account for sampling bias. Fracture spacing is dominantly lognormal, though two subordinate fracture sets have a power law spacing. This difference in spacing distributions may reflect the influence of the andesitic sequence stratification (lognormal) and tectonic faults (power law). Fracture thicknesses of 9-30 mm observed in BHTV logs, and 1-3 mm in cores, are interpreted to follow a power law. Fractures in thin sections (˜5 μm thick) do not fit this power law distribution, which, together with their orientation, reflect a change of controls on fracture thickness from uniform (such as thermal) controls at thin section scale to anisotropic (tectonic) at core and BHTV scales of observation. However, the ˜5% volumetric percentage of fractures within the rock at all three scales suggests a self-similar behavior in 3-D. Power law thickness distributions potentially associated with power law fluid flow rates, and increased connectivity where fracture sets intersect, may cause the large permeability variations that occur at hundred meter scales in the reservoir. The described fracture geometries can be incorporated into fracture and flow models to explore the roles of fracture connectivity, stress, and mineral precipitation/dissolution on permeability in such andesite-hosted geothermal systems.

  13. Self-designed femoral neck guide pin locator for femoral neck fractures.

    Science.gov (United States)

    Xia, Shengli; Wang, Ziping; Wang, Minghui; Wu, Zuming; Wang, Xiuhui

    2014-01-01

    Closed reduction and fixation with 3 cannulated screws is a widely accepted surgery for the treatment of femoral neck fractures. However, how to obtain optimal screw placement remains unclear. In the current study, the authors designed a guide pin positioning system for femoral neck fracture cannulated screw fixation and examined its application value by comparing it with freehand guide needle positioning and with general guide pin locator positioning provided by equipment manufacturers. The screw reset rate, screw parallelism, triangle area formed by the link line of the entry point of 3 guide pins, and maximum vertical load bearing of the femoral neck after internal fixation were recorded. As expected, the triangle area was largest in the self-designed positioning group, followed by the general positioning group and the freehand positioning group. The difference among the 3 groups was statistically significant (P.05). The authors’ self-designed guide pin positioning system has the potential to accurately insert cannulated screws in femoral neck fractures and may reduce bone loss and unnecessary radiation.

  14. Evaluation of the fracture resistance of computer-aided design/computer-aided manufacturing monolithic crowns prepared in different cement thicknesses.

    Science.gov (United States)

    Sagsoz, N Polat; Yanıkoglu, N

    2018-04-01

    The purpose of this study was to evaluate the fracture resistance of monolithic computer-aided design/computer-aided manufacturing (CAD/CAM) crowns that are prepared with different cement thickness. For this investigation, a human maxillary premolar tooth was selected. Master model preparation was performed with a demand bur under water spray. Master die was taken to fabricate 105 epoxy resin replicas. The crowns were milled using a CEREC 4 CAD/CAM system (Software Version, 4.2.0.57192). CAD/CAM crowns were made using resin nanoceramic, feldspathic glass ceramic, lithium disilicate, and leucite-reinforced ceramics. Each group was subdivided into three groups in accordance with three different cement thicknesses (30, 90, and 150 μm). Crowns milled out. Then RelyX ™ U200 was used as a luting agent to bond the crowns to the prepared samples. After one hour cementations, the specimens were stored in water bath at 37°C for 1 week before testing. Seven unprepared and unrestored teeth were kept and tested as a control group. A universal test machine was used to assume the fracture resistance of all specimens. The compressive load (N) that caused fracture was recorded for each specimen. Fracture resistance data were statistically analyzed by one-way ANOVA and two-factor interaction modeling test (α = 0.001). There are statistically significant differences between fracture resistances of CAD/CAM monolithic crown materials (P cement thickness is not statistically significant for fracture resistance of CAD/CAM monolithic crowns (P > 0.001). CAD/CAM monolithic crown materials affected fracture resistance. Cement thickness (30, 90, and 150 μm) was not effective on fracture resistance of CAD/CAM monolithic crowns.

  15. Assessing the role of cation exchange in controlling groundwater chemistry during fluid mixing in fractured granite at Aespoe, Sweden

    International Nuclear Information System (INIS)

    Viani, B.E.; Bruton, C.J.

    1996-06-01

    Geochemical modeling was used to simulate the mixing of dilute shallow groundwater with deeper more saline groundwater in the fractured granite of the Redox Zone at the Aespoe underground Hard Rock Laboratory (HRL). Fluid mixing simulations were designed to assess the role that cation exchange plays in controlling the composition of fluids entering the HRL via fracture flow. Mixing simulations included provision for the effects of mineral precipitation and cation exchange on fluid composition. Because the predominant clay mineral observed in fractures in the Redox Zone has been identified as illite or mixed layer illite smectite, an exchanger with the properties of illite was used to simulate cation exchange. Cation exchange on illite was modeled using three exchange sites, a planar or basal plane site with properties similar to smectite, and two edge sites that have very high affinities for K, Rb, and Cs. Each site was assumed to obey an ideal Vanselow exchange model, and exchange energies for each site were taken from the literature. The predicted behaviors of Na, Ca, and Mg during mixing were similar to those reported in a previous study in which smectite was used as the model for the exchanger. The trace elements Cs and Rb were predicted to be strongly associated with the illite exchanger, and the predicted concentrations of Cs in fracture fill were in reasonable agreement with reported chemical analyses of exchangeable Cs in fracture fill. The results of the geochemical modeling suggest that Na, Ca, and Sr concentrations in the fluid phase may be controlled by cation exchange reactions that occur during mixing, but that Mg appears to behave conservatively. There is currently not enough data to make conclusions regarding the behavior of Cs and Rb

  16. Vitamin D and Fracture Risk in Early Childhood: A Case-Control Study.

    Science.gov (United States)

    Anderson, Laura N; Heong, Sze Wing; Chen, Yang; Thorpe, Kevin E; Adeli, Khosrow; Howard, Andrew; Sochett, Etienne; Birken, Catherine S; Parkin, Patricia C; Maguire, Jonathon L

    2017-06-15

    The objective of this study was to evaluate the association of vitamin D intake and serum levels with fracture risk in children under 6 years of age. A case-control study was conducted in Toronto, Ontario, Canada. Cases were recruited from the fracture clinic at the Hospital for Sick Children, and matched controls were obtained from the TARGet Kids! primary-care research network. Controls were matched to cases on age, sex, height, and season. Fracture risk was estimated from conditional logistic regression, with adjustment for skin type, fracture history, waist circumference, outdoor free play, neighborhood income, soda consumption, and child's birth weight. A total of 206 cases were recruited during May 2009-April 2013 and matched to 343 controls. Serum 25-hydroxyvitamin D concentration (per 10-nmol/L increment: adjusted odds ratio (aOR) = 0.95, 95% confidence interval (CI): 0.88, 1.03) and intake of cow's milk (2 cups/day vs. 2 cups/day: aOR = 1.39 (95% CI: 0.85, 2.23)) were not significantly associated with reduced odds of fracture. A statistically significant association was observed between child use of vitamin D supplements and decreased odds of fracture (yes vs. no: aOR = 0.42, 95% CI: 0.25, 0.69). Vitamin D supplementation, but not serum 25-hydroxyvitamin D level or milk intake, was associated with reduced fracture risk among these healthy young children. © The Author 2017. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  17. Practical design control implementation for medical devices

    CERN Document Server

    Justiniano, Jose

    2003-01-01

    Bringing together the concepts of design control and reliability engineering, this book is a must for medical device manufacturers. It helps them meet the challenge of designing and developing products that meet or exceed customer expectations and also meet regulatory requirements. Part One covers motivation for design control and validation, design control requirements, process validation and design transfer, quality system for design control, and measuring design control program effectiveness. Part Two discusses risk analysis and FMEA, designing-in reliability, reliability and design verific

  18. Pilot case-control investigation of risk factors for hip fractures in the urban Indian population

    Directory of Open Access Journals (Sweden)

    Malhotra Nidhi

    2010-03-01

    Full Text Available Abstract Background Despite the reported high prevalence of osteoporosis in India, there have been no previous studies examining the risk factors for hip fracture in the Indian population. Methods We carried out a case control investigation comprising 100 case subjects (57 women and 43 men admitted with a first hip fracture into one of three hospitals across New Delhi. The 100 controls were age and sex matched subjects who were either healthy visitors not related to the case patients or hospital staff. Information from all subjects was obtained through a questionnaire based interview. Results There was a significant increase in the number of cases of hip fracture with increasing age. There were significantly more women (57% than men (43%. Univariate analysis identified protective effects for increased activity, exercise, calcium and vitamin supplements, almonds, fish, paneer (cottage cheese, curd (plain yogurt, and milk. However, tea and other caffeinated beverages were significant risk factors. In women, hormone/estrogen therapy appeared to have a marginal protective effect. For all cases, decreased agility, visual impairment, long term medications, chronic illnesses increased the risk of hip fracture. The multivariate analysis confirmed a protective effect of increased activity and also showed a decrease in hip fracture risk with increasing body mass index (odds ratio (OR 0.024, 95% confidence interval (CI 0.006-0.10 & OR 0.81, 95% CI 0.68-0.97 respectively. Individuals who take calcium supplements have a decreased risk of hip fracture (OR 0.076; CI 0.017-0.340, as do individuals who eat fish (OR 0.094; CI 0.020-0.431, and those who eat paneer (OR 0.152; 0.031-0.741. Tea drinkers have a higher risk of hip fracture (OR 22.8; 95% CI 3.73-139.43. Difficulty in getting up from a chair also appears to be an important risk factor for hip fractures (OR 14.53; 95% CI 3.86-54.23. Conclusions In the urban Indian population, dietary calcium, vitamin D

  19. Hollow Abutment Screw Design for Easy Retrieval in Case of Screw Fracture in Dental Implant System.

    Science.gov (United States)

    Sim, Bo Kyun; Kim, Bongju; Kim, Min Jeong; Jeong, Guk Hyun; Ju, Kyung Won; Shin, Yoo Jin; Kim, Man Yong; Lee, Jong-Ho

    2017-01-01

    The prosthetic component of dental implant is attached on the abutment which is connected to the fixture with an abutment screw. The abutment screw fracture is not frequent; however, the retrieval of the fractured screw is not easy, and it poses complications. A retrieval kit was developed which utilizes screw removal drills to make a hole on the fractured screw that provides an engaging drill to unscrew it. To minimize this process, the abutment screw is modified with a prefabricated access hole for easy retrieval. This study aimed to introduce this modified design of the abutment screw, the concept of easy retrieval, and to compare the mechanical strengths of the conventional and hollow abutment screws by finite element analysis (FEA) and mechanical test. In the FEA results, both types of abutment screws showed similar stress distribution in the single artificial tooth system. A maximum load difference of about 2% occurred in the vertical load by a mechanical test. This study showed that the hollow abutment screw may be an alternative to the conventional abutment screws because this is designed for easy retrieval and that both abutment screws showed no significant difference in the mechanical tests and in the FEA.

  20. Hollow Abutment Screw Design for Easy Retrieval in Case of Screw Fracture in Dental Implant System

    Directory of Open Access Journals (Sweden)

    Bo Kyun Sim

    2017-01-01

    Full Text Available The prosthetic component of dental implant is attached on the abutment which is connected to the fixture with an abutment screw. The abutment screw fracture is not frequent; however, the retrieval of the fractured screw is not easy, and it poses complications. A retrieval kit was developed which utilizes screw removal drills to make a hole on the fractured screw that provides an engaging drill to unscrew it. To minimize this process, the abutment screw is modified with a prefabricated access hole for easy retrieval. This study aimed to introduce this modified design of the abutment screw, the concept of easy retrieval, and to compare the mechanical strengths of the conventional and hollow abutment screws by finite element analysis (FEA and mechanical test. In the FEA results, both types of abutment screws showed similar stress distribution in the single artificial tooth system. A maximum load difference of about 2% occurred in the vertical load by a mechanical test. This study showed that the hollow abutment screw may be an alternative to the conventional abutment screws because this is designed for easy retrieval and that both abutment screws showed no significant difference in the mechanical tests and in the FEA.

  1. Hollow Abutment Screw Design for Easy Retrieval in Case of Screw Fracture in Dental Implant System

    Science.gov (United States)

    Kim, Bongju; Shin, Yoo Jin

    2017-01-01

    The prosthetic component of dental implant is attached on the abutment which is connected to the fixture with an abutment screw. The abutment screw fracture is not frequent; however, the retrieval of the fractured screw is not easy, and it poses complications. A retrieval kit was developed which utilizes screw removal drills to make a hole on the fractured screw that provides an engaging drill to unscrew it. To minimize this process, the abutment screw is modified with a prefabricated access hole for easy retrieval. This study aimed to introduce this modified design of the abutment screw, the concept of easy retrieval, and to compare the mechanical strengths of the conventional and hollow abutment screws by finite element analysis (FEA) and mechanical test. In the FEA results, both types of abutment screws showed similar stress distribution in the single artificial tooth system. A maximum load difference of about 2% occurred in the vertical load by a mechanical test. This study showed that the hollow abutment screw may be an alternative to the conventional abutment screws because this is designed for easy retrieval and that both abutment screws showed no significant difference in the mechanical tests and in the FEA. PMID:29065610

  2. A prospective, controlled clinical evaluation of surgical stabilization of severe rib fractures.

    Science.gov (United States)

    Pieracci, Fredric M; Lin, Yihan; Rodil, Maria; Synder, Madelyne; Herbert, Benoit; Tran, Dong Kha; Stoval, Robert T; Johnson, Jeffrey L; Biffl, Walter L; Barnett, Carlton C; Cothren-Burlew, Clay; Fox, Charles; Jurkovich, Gregory J; Moore, Ernest E

    2016-02-01

    Previous studies of surgical stabilization of rib fractures (SSRF) have been limited by small sample sizes, retrospective methodology, and inclusion of only patients with flail chest. We performed a prospective, controlled evaluation of SSRF as compared with optimal medical management for severe rib fracture patterns among critically ill trauma patients. We hypothesized that SSRF improves acute outcomes. We conducted a 2-year clinical evaluation of patients with any of the following rib fracture patterns: flail chest, three or more fractures with bicortical displacement, 30% or greater hemithorax volume loss, and either severe pain or respiratory failure despite optimal medical management. In the year 2013, all patients were managed nonoperatively. In the year 2014, all patients were managed operatively. Outcomes included respiratory failure, tracheostomy, pneumonia, ventilator days, tracheostomy, length of stay, daily maximum incentive spirometer volume, narcotic requirements, and mortality. Univariate and multivariable analyses were performed. Seventy patients were included, 35 in each group. For the operative group, time from injury to surgery was 2.4 day, operative time was 1.5 hours, and the ratio of ribs fixed to ribs fractured was 0.6. The operative group had a significantly higher RibScore (4 vs. 3, respectively, p fracture patterns. Therapeutic study, level II.

  3. [Distal radius fractures--retrospective quality control after conservative and operative therapy].

    Science.gov (United States)

    Sommer, C; Brendebach, L; Meier, R; Leutenegger, A

    2001-01-01

    The distal radius fracture is the most frequent fracture in the adult patient. The wide spectrum of different types of fracture and the coexisting factors make the choice for the optimal treatment difficult. As an interne quality control we retrospectively evaluated all patients with distal radius fractures treated in 1995 at our institution. The study included 69 adult patients with 71 distal radius fractures. After on average 26 months 58 patients with 59 fractures were clinically and radiologically evaluated. The patients were asked to give supplementary information about their follow-up treatment as well as any remaining physical difficulties and limitations in the daily life. All x-rays of the broken radius were carefully analysed and compared with the opposite side. The final results were evaluated according to the "Demerit Point System". Patients were treated with five different therapeutical methods. 76.3% of the patients showed a very good/good final result. In 56.7% of the cases secondary fracture dislocation occurred; the dislocation-rate of fractures treated with percutaneous k-wires was 93.3%! A clear correlation between secondary displacement and final results was found. A main factor for an optimal outcome is the anatomic restoration of length and axis of the distal radius as well as of joint congruency, also moderate angular deformities are well tolerated. Our collective showed an unexpected high rate of secondary displacement, especially in the k-wire group. The reasons for this unsatisfactory event are manifold: too optimistic indication, insufficient follow-up examination in the first four to six weeks, inconsequent change to a more stable fixation method in case of a secondary dislocation. The results of this retrospective evaluation had a major impact on our concept of treatment. The dorso-radial double-plate technique combined with bone graft will be more used in the future especially in younger patients. The new standardised concept is the

  4. HAMMLAB 1999 experimental control room: design - design rationale - experiences

    International Nuclear Information System (INIS)

    Foerdestroemmen, N. T.; Meyer, B. D.; Saarni, R.

    1999-01-01

    A presentation of HAMMLAB 1999 experimental control room, and the accumulated experiences gathered in the areas of design and design rationale as well as user experiences. It is concluded that HAMMLAB 1999 experimental control room is a realistic, compact and efficient control room well suited as an Advanced NPP Control Room (ml)

  5. Fracture mechanics aspects in the safe design of ductile iron shipping and storage containers

    International Nuclear Information System (INIS)

    Sappok, M.; Bounin, D.

    1996-01-01

    Containers made of ductile cast iron provide a safe method for transport of radioactive material. Contrary to widespread opinion ductile cast iron is a very tough material and can be manufactured in heavy sections. The containers are designed to withstand the very high impact loads of accidents like free drops onto unyielding targets. The design is based on postulated undetected crack-like flaws at the highest stressed location. Design must show that applied stress intensities are smaller than fracture toughness and no crack initiation and therefore also no crack propagation can occur. The design procedure followed in this paper is given in a new guideline still being drafted by the International Atomic Energy Agency

  6. Effect of Control Mode and Test Rate on the Measured Fracture Toughness of Advanced Ceramics

    Science.gov (United States)

    Hausmann, Bronson D.; Salem, Jonathan A.

    2018-01-01

    The effects of control mode and test rate on the measured fracture toughness of ceramics were evaluated by using chevron-notched flexure specimens in accordance with ASTM C1421. The use of stroke control gave consistent results with about 2% (statistically insignificant) variation in measured fracture toughness for a very wide range of rates (0.005 to 0.5 mm/min). Use of strain or crack mouth opening displacement (CMOD) control gave approx. 5% (statistically significant) variation over a very wide range of rates (1 to 80 µm/m/s), with the measurements being a function of rate. However, the rate effect was eliminated by use of dry nitrogen, implying a stress corrosion effect rather than a stability effect. With the use of a nitrogen environment during strain controlled tests, fracture toughness values were within about 1% over a wide range of rates (1 to 80 micons/m/s). CMOD or strain control did allow stable crack extension well past maximum force, and thus is preferred for energy calculations. The effort is being used to confirm recommendations in ASTM Test Method C1421 on fracture toughness measurement.

  7. Experimental validation of microseismic emissions from a controlled hydraulic fracture in a synthetic layered medium

    Science.gov (United States)

    Roundtree, Russell

    A controlled hydraulic fracture experiment was performed on two medium sized (11" x 11" x 15") synthetic layered blocks of low permeability, low porosity Lyons sandstone sandwiched between cement. The purpose of the research was to better understand and characterize the fracture evolution as the fracture tip impinged upon the layer boundaries between the well bonded layers. It is also one of the first documented uses of passive microseismic used in a laboratory environment to characterize hydraulic fracturing. A relatively low viscosity fluid of 1000 centipoise, compared to properly scaled previous work (Casas 2005, and Athavale 2007), was pumped at a constant rate of 10 mL/minute through a steel cased hole landed and isolated in the sandstone layer. Efforts were made to contain the hydraulic fracture within the confines of the rock specimen to retain the created hydraulic fracture geometry. Two identical samples and treatment schedules were created and differed only in the monitoring system used to characterize the microseismic activity during the fracture treatment. The first block had eight embedded P-wave transducers placed in the sandstone layer to record the passive microseismic emissions and localize the location and time of the acoustic event. The second block had six compressional wave transducers and twelve shear wave transducers embedded in the sandstone layer of the block. The intention was to record and process the seismic data using conventional P-wave to S-wave difference timing techniques well known in industry. While this goal ultimately not possible due to the geometry of the receiver placements and the limitations of the Vallene acquisition processing software, the data received and the events localized from the 18 transducer test were of much higher numbers and quality than on the eight transducer test. This experiment proved conclusively that passive seismic emission recording can yield positive results in the laboratory. Just as in the field

  8. Effects of framework design and layering material on fracture strength of implant-supported zirconia-based molar crowns.

    Science.gov (United States)

    Kamio, Shingo; Komine, Futoshi; Taguchi, Kohei; Iwasaki, Taro; Blatz, Markus B; Matsumura, Hideo

    2015-12-01

    To evaluate the effects of framework design and layering material on the fracture strength of implant-supported zirconia-based molar crowns. Sixty-six titanium abutments (GingiHue Post) were tightened onto dental implants (Implant Lab Analog). These abutment-implant complexes were randomly divided into three groups (n = 22) according to the design of the zirconia framework (Katana), namely, uniform-thickness (UNI), anatomic (ANA), and supported anatomic (SUP) designs. The specimens in each design group were further divided into two subgroups (n = 11): zirconia-based all-ceramic restorations (ZAC group) and zirconia-based restorations with an indirect composite material (Estenia C&B) layered onto the zirconia framework (ZIC group). All crowns were cemented on implant abutments, after which the specimens were tested for fracture resistance. The data were analyzed with the Kruskal-Wallis test and the Mann-Whitney U-test with the Bonferroni correction (α = 0.05). The following mean fracture strength values (kN) were obtained in UNI design, ANA design, and SUP design, respectively: Group ZAC, 3.78, 6.01, 6.50 and Group ZIC, 3.15, 5.65, 5.83. In both the ZAC and ZIC groups, fracture strength was significantly lower for the UNI design than the other two framework designs (P = 0.001). Fracture strength did not significantly differ (P > 0.420) between identical framework designs in the ZAC and ZIC groups. A framework design with standardized layer thickness and adequate support of veneer by zirconia frameworks, as in the ANA and SUP designs, increases fracture resistance in implant-supported zirconia-based restorations under conditions of chewing attrition. Indirect composite material and porcelain perform similarly as layering materials on zirconia frameworks. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  9. Biomechanical study in vitro on the use of self-designed external fixator in diaphyseal III metacarpal fractures in horses.

    Science.gov (United States)

    Turek, B; Potyński, A; Wajler, C; Szara, T; Czopowicz, M; Drewnowska, O

    2015-01-01

    Diaphyseal fractures of the III metacarpal bone represent 22% of all fractures of the long bones in horses. Treatment of such cases is difficult. The most popular solution used in these types of fractures is two plates applied directly to the bone surface, but they are not applicable on contaminated and infected fractures. External fixators are quite commonly used in human medicine, although in veterinary practice there is no typical stabilizer designed for the treatment of diaphyseal fractures of the III metacarpal bone so far. In this study, an external semicircular fixator of our own design was used and in vitro strength tests were conducted to determine the maximum force which would lead to the destruction of non-fractured bone and fractured bone treated with the stabilizer. On the basis of the strength tests, we can conclude that the stabilizer can be strong enough to allow the horse to stand up after surgery. It also has many favorable features which make it easy to assemble and to take care of a wound, while being safe enough for the animal at the same time.

  10. Open reduction versus endoscopically controlled reconstruction of orbital floor fractures: a retrospective analysis.

    NARCIS (Netherlands)

    Hundepool, A.C.; Willemsen, M.A.A.P.; Koudstaal, M.J.; Wal, K.G.H. van der

    2012-01-01

    The aim of this study was to compare the postoperative results of open reduction versus endoscopically controlled reconstructions of orbital floor fractures. The medical records of 83 patients, treated between January 2000 and December 2008, were reviewed for enophthalmos, diplopia and

  11. Definition of infection after fracture fixation: A systematic review of randomized controlled trials to evaluate current practice.

    Science.gov (United States)

    Metsemakers, W J; Kortram, K; Morgenstern, M; Moriarty, T F; Meex, I; Kuehl, R; Nijs, S; Richards, R G; Raschke, M; Borens, O; Kates, S L; Zalavras, C; Giannoudis, P V; Verhofstad, M H J

    2018-03-01

    One of the most challenging musculoskeletal complications in modern trauma surgery is infection after fracture fixation (IAFF). Although infections are clinically obvious in many cases, a clear definition of the term IAFF is crucial, not only for the evaluation of published research data but also for the establishment of uniform treatment concepts. The aim of this systematic review was to identify the definitions used in the scientific literature to describe infectious complications after internal fixation of fractures. The hypothesis of this study was that the majority of fracture-related literature do not define IAFF. A comprehensive search was performed in Embase, Cochrane, Google Scholar, Medline (OvidSP), PubMed publisher and Web-of-Science for randomized controlled trials (RCTs) on fracture fixation. Data were collected on the definition of infectious complications after fracture fixation used in each study. Study selection was accomplished through two phases. During the first phase, titles and abstracts were reviewed for relevance, and the full texts of relevant articles were obtained. During the second phase, full-text articles were reviewed. All definitions were literally extracted and collected in a database. Then, a classification was designed to rate the quality of the description of IAFF. A total of 100 RCT's were identified in the search. Of 100 studies, only two (2%) cited a validated definition to describe IAFF. In 28 (28%) RCTs, the authors used a self-designed definition. In the other 70 RCTs, (70%) there was no description of a definition in the Methods section, although all of the articles described infections as an outcome parameter in the Results section. This systematic review shows that IAFF is not defined in a large majority of the fracture-related literature. To our knowledge, this is the first study conducted with the objective to explore this important issue. The lack of a consensus definition remains a problem in current orthopedic

  12. [Effects of Surgically Treated Pelvic Ring and Acetabular Fractures on Postural Control].

    Science.gov (United States)

    Lang, P; Schnegelberger, A; Riesner, H-J; Stuby, F; Friemert, B; Palm, H-G

    2016-04-01

    The aim of surgical treatment of pelvic ring and acetabular fractures is to allow rapid mobilisation of patients in order to restore stance and gait stability (postural control), as this significantly correlates with a positive outcome. The regulation of postural stability is mainly controlled by transmission of proprioceptive stimuli. In addition, the pelvis serves as a connection between the legs and the spine and thus is also of great importance for mechanical stabilisation. It remains unclear whether surgical treatment of pelvic ring and acetabular fractures affects the regulation of postural control. Therefore, the aim of this study was to examine the impact of surgically treated pelvic ring and acetabular fractures on postural stability by means of computerised dynamic posturography (CDP) after a mean of 35 months and to compare the results with a healthy control group. A retrospective case control study of 38 patients with surgically treated pelvic ring and acetabular fractures and 38 healthy volunteers was carried out using CDP. The average time of follow-up was 35 (12-78) months. The most important outcome parameter in this investigation was the overall stability index (OSI). Hip joint mobility, the health-related quality of life (SF-12) and pain were supplementary outcome parameters. It was found that surgically treated pelvic ring and acetabular fractures had no influence on postural stability. The OSI was 2.1 ° in the patient group and 1.9 ° in the control group. There was no significant difference between the groups in hip joint mobility. A total of 52 % of patients showed no or only mild pain. Mean health-related quality of life was the same as in the total population. Surgically treated pelvic ring and acetabular fractures do not lead to deterioration in postural control in the mid term. This is of high prognostic importance for rapid mobilisation of the patients. Therefore no increase in the risk of falling is expected after successfully

  13. Scaphoid Waist Internal Fixation for Fractures Trial (SWIFFT) protocol: a pragmatic multi-centre randomised controlled trial of cast treatment versus surgical fixation for the treatment of bi-cortical, minimally displaced fractures of the scaphoid waist in adults.

    Science.gov (United States)

    Dias, Joseph; Brealey, Stephen; Choudhary, Surabhi; Cook, Liz; Costa, Matthew; Fairhurst, Caroline; Hewitt, Catherine; Hodgson, Stephen; Jefferson, Laura; Jeyapalan, Kanagaratnam; Keding, Ada; Leighton, Paul; Rangan, Amar; Richardson, Gerry; Rothery, Claire; Taub, Nicholas; Thompson, John; Torgerson, David

    2016-06-04

    this. The SWIFFT Trial is a rigorously designed and adequately powered study which aims to contribute to the evidence-base to inform clinical decisions for the treatment of this common fracture in adults. The trial is registered with the International Standard Randomised Controlled Trial Register ( ISRCTN67901257 ). Date registration assigned was 13/02/2013.

  14. Controller Design Automation for Aeroservoelastic Design Optimization of Wind Turbines

    NARCIS (Netherlands)

    Ashuri, T.; Van Bussel, G.J.W.; Zaayer, M.B.; Van Kuik, G.A.M.

    2010-01-01

    The purpose of this paper is to integrate the controller design of wind turbines with structure and aerodynamic analysis and use the final product in the design optimization process (DOP) of wind turbines. To do that, the controller design is automated and integrated with an aeroelastic simulation

  15. Parameters controlling fracturing distribution: example of an Upper Jurassic marly-calcareous formation (eastern Paris Basin)

    International Nuclear Information System (INIS)

    Andre, G.; Rebours, H.; Wileveau, Y.; Proudhon, B.

    2006-01-01

    Study of fractures along a 490-m vertical section of marl/limestone alternations in the Upper Jurassic (Meuse/Haute-Marne underground research laboratory-eastern Paris Basin) reveals their organization and the different states of palaeo-stress. Type and extension of tectonic structures seem to be controlled principally by lithology and secondary by depth. Also, it appears deviations of Alpine palaeo-stresses between Kimmeridgian and Oxfordian formations. These deviations are related to the presence of marl/limestone contacts. The vertical evolution of current horizontal maximum stress shows a similar behaviour, with deviations at the walls of Callovo-Oxfordian argilites. These results allow us to point out and to discuss the impact of lithology, rheology and depth on fracturing occurrence and distribution. Furthermore, this study suggests the role of Callovo-Oxfordian as a barrier for fracture development between the limestones of Dogger and Oxfordian formations. (authors)

  16. Control effect of fracture on hard coal cracking in a fully mechanized longwall top coal caving face

    Energy Technology Data Exchange (ETDEWEB)

    Jin-ping Wei; Zhong-hua Li; Pei-miao Sang; Shang-qiang Chen [Henan Polytechnic University, Jiaozuo (China). School of Energy Science and Engineering

    2009-03-15

    Through theoretical analysis, simulation test and practice, the law of a fracture's influence on hard top coal press cracking was studied. The study focused on the relation between fracture and coal strength, top coal caving ability and work face layout. Based on the investigation of the fracture system, the control of press cracking was achieved by matching working face to fracture orientation to improve top-coal caving ability and recovery. The matching principle was pointed out: the top-coal caving working face should be perpendicular to or obliquely cross the primary fracture at a large angle, and cross the secondary fracture at a small angle. The rational match can increase the recovery ratio of top-coal and avoid rib spalling. The application of control technology on hard top coal press cracking was introduced at the longwall top-coal caving face. 10 refs., 2 figs., 1 tab.

  17. Lumbar lordosis and pars interarticularis fractures: a case-control study

    International Nuclear Information System (INIS)

    Bugg, William G.; Lewis, Mark; Juette, Arne; Cahir, John G.; Toms, Andoni P.

    2012-01-01

    The aim of this study is to examine the relationship between lumbar lordosis and pars interarticularis fractures. In this retrospective case-control study we compare the angle of lumbar lordosis and the angle of the S1 vertebral endplate (as a measure of pelvic tilt) in patients with bilateral L5 pars interarticularis fractures with age- and sex-matched control cases with normal MRI examinations of the lumbar spine. Twenty-nine cases of bilateral L5 pars interarticularis fractures with matched control-cases were identified on MRI (16 male, 13 female, age 9-63 years). The angle of lordosis was measured between the inferior L4 and superior S1 vertebral endplates on a standing lateral lumbar spine radiograph for both groups. The mean angle of lordosis about the L5 vertebra was 36.9 (SD = 6.5 ) in the pars interarticularis fracture group, and 30.1 (SD = 6.4 ) in the control group. The difference between the two groups was significant (mean difference 6.8 , Student's t test: P < 0.001). The mean angle of sacral tilt measured was 122.2 (SD = 10.16 ) for controls and 136.4 (SD = 10.86 ) for patients with pars defects. The difference in the means of 14.2 was statistically significantly different (P < 0.0001). Sacral tilt represented by a steeply angled superior endplate of S1 is associated with a significantly increased angle of lordosis, between L4 and S1, and pars fractures at L5. Steep angulation of the first sacral vertebral segment maybe the predisposing biomechanical factor that leads to pincer-like impingement of the pars interarticularis and then spondylolysis. (orig.)

  18. Lumbar lordosis and pars interarticularis fractures: a case-control study

    Energy Technology Data Exchange (ETDEWEB)

    Bugg, William G; Lewis, Mark; Juette, Arne; Cahir, John G; Toms, Andoni P [Cotman Centre, Norwich Radiology Academy, Norwich, Norfolk (United Kingdom)

    2012-07-15

    The aim of this study is to examine the relationship between lumbar lordosis and pars interarticularis fractures. In this retrospective case-control study we compare the angle of lumbar lordosis and the angle of the S1 vertebral endplate (as a measure of pelvic tilt) in patients with bilateral L5 pars interarticularis fractures with age- and sex-matched control cases with normal MRI examinations of the lumbar spine. Twenty-nine cases of bilateral L5 pars interarticularis fractures with matched control-cases were identified on MRI (16 male, 13 female, age 9-63 years). The angle of lordosis was measured between the inferior L4 and superior S1 vertebral endplates on a standing lateral lumbar spine radiograph for both groups. The mean angle of lordosis about the L5 vertebra was 36.9 (SD = 6.5 ) in the pars interarticularis fracture group, and 30.1 (SD = 6.4 ) in the control group. The difference between the two groups was significant (mean difference 6.8 , Student's t test: P < 0.001). The mean angle of sacral tilt measured was 122.2 (SD = 10.16 ) for controls and 136.4 (SD = 10.86 ) for patients with pars defects. The difference in the means of 14.2 was statistically significantly different (P < 0.0001). Sacral tilt represented by a steeply angled superior endplate of S1 is associated with a significantly increased angle of lordosis, between L4 and S1, and pars fractures at L5. Steep angulation of the first sacral vertebral segment maybe the predisposing biomechanical factor that leads to pincer-like impingement of the pars interarticularis and then spondylolysis. (orig.)

  19. Lumbar lordosis and pars interarticularis fractures: a case-control study

    Energy Technology Data Exchange (ETDEWEB)

    Bugg, William G.; Lewis, Mark; Juette, Arne; Cahir, John G.; Toms, Andoni P. [Cotman Centre, Norwich Radiology Academy, Norwich, Norfolk (United Kingdom)

    2012-07-15

    The aim of this study is to examine the relationship between lumbar lordosis and pars interarticularis fractures. In this retrospective case-control study we compare the angle of lumbar lordosis and the angle of the S1 vertebral endplate (as a measure of pelvic tilt) in patients with bilateral L5 pars interarticularis fractures with age- and sex-matched control cases with normal MRI examinations of the lumbar spine. Twenty-nine cases of bilateral L5 pars interarticularis fractures with matched control-cases were identified on MRI (16 male, 13 female, age 9-63 years). The angle of lordosis was measured between the inferior L4 and superior S1 vertebral endplates on a standing lateral lumbar spine radiograph for both groups. The mean angle of lordosis about the L5 vertebra was 36.9 (SD = 6.5 ) in the pars interarticularis fracture group, and 30.1 (SD = 6.4 ) in the control group. The difference between the two groups was significant (mean difference 6.8 , Student's t test: P < 0.001). The mean angle of sacral tilt measured was 122.2 (SD = 10.16 ) for controls and 136.4 (SD = 10.86 ) for patients with pars defects. The difference in the means of 14.2 was statistically significantly different (P < 0.0001). Sacral tilt represented by a steeply angled superior endplate of S1 is associated with a significantly increased angle of lordosis, between L4 and S1, and pars fractures at L5. Steep angulation of the first sacral vertebral segment maybe the predisposing biomechanical factor that leads to pincer-like impingement of the pars interarticularis and then spondylolysis. (orig.)

  20. Design concept of Hydro cascade control system

    International Nuclear Information System (INIS)

    Fustik, Vangel; Kiteva, Nevenka

    2006-01-01

    In this paper a design concept of the comple hydro cascade scheme is presented with the design parameters of the main technical features. The cascade control system architecture is designed considering up-to-date communication and information technology. The control algorithm is based on Pond Level Control and Economic Load Allocation concepts.

  1. 10 CFR 72.146 - Design control.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 2 2010-01-01 2010-01-01 false Design control. 72.146 Section 72.146 Energy NUCLEAR... Design control. (a) The licensee, applicant for a license, certificate holder, and applicant for a CoC... shall establish measures for the identification and control of design interfaces and for coordination...

  2. Guidelines for control room design reviews

    International Nuclear Information System (INIS)

    1981-09-01

    The control room design review is part of a broad program being undertaken by the nuclear industry and the government to ensure consideration of human factors in nuclear power plant design and operation. The purpose of the control room design review described by these guidelines is to (1) review and evaluate the control room workspace, instrumentation, controls, and other equipment from a human factors engineering point of view that takes into account both system demands and operator capabilities; and (2) to identify, assess, and implement control room design modifications that correct inadequate or unsuitable items. The scope of the control room design review described by these guidelines covers the human engineering review of completed control rooms; i.e., operational control rooms or those at that stage of the licensing process where control room design and equipment selection are committed. These guidelines should also be of use during the design process for new control rooms. However, additional analyses to optimize the allocation of functions to man and machine, and further examination of advanced control system technology, are recommended for new control rooms. Guidelines and references for comprehensive system analyses designed to incorporate human factors considerations into the design and development of new control rooms are presented in Appendix B. Where possible, a generic approach to the control room design review process is encouraged; for example, when control room designs are replicated wholly or in part in two or more units. Even when designs are not replicated exactly, generic reviews which can be modified to account for specific differences in particular control rooms should be considered. Industry organizations and owners groups are encouraged to coordinate joint efforts and share data to develop generic approaches to the design review process. The control room design review should accomplish the following specific objectives. To determine

  3. Design techniques for mutlivariable flight control systems

    Science.gov (United States)

    1981-01-01

    Techniques which address the multi-input closely coupled nature of advanced flight control applications and digital implementation issues are described and illustrated through flight control examples. The techniques described seek to exploit the advantages of traditional techniques in treating conventional feedback control design specifications and the simplicity of modern approaches for multivariable control system design.

  4. Prevention of brittle fracture of steel structures by controlling the local stress and strain fields

    Directory of Open Access Journals (Sweden)

    Moyseychik Evgeniy Alekseevich

    Full Text Available In the article the author offers a classification of the methods to increase the cold resistance of steel structural shapes with a focus on the regulation of local fields of internal stresses and strains to prevent brittle fracture of steel structures. The need of a computer thermography is highlighted not only for visualization of temperature fields on the surface, but also to control the fields of residual stresses and strains in a controlled element.

  5. Prototyping qualitative controllers for fuzzy-logic controller design

    International Nuclear Information System (INIS)

    Bakhtiari, S.; Jabedar-Maralani, P.

    1999-05-01

    Qualitative controls can be designed for linear and nonlinear models with the same computational complexity. At the same time they show the general form of the proper control. These properties can help ease the design process for quantitative controls. In this paper qualitative controls are used as prototypes for the design of linear or nonlinear, and in particular Sugeno-type fuzzy, controls. The LMS identification method is used to approximate the qualitative control with the nearest fuzzy control. The method is applied to the problem of position control in a permanent magnet synchronous motor; moreover, the performance and the robustness of the two controllers are compared

  6. Mechanical engineers' handbook, design, instrumentation, and controls

    CERN Document Server

    Kutz, Myer

    2015-01-01

    Full coverage of electronics, MEMS, and instrumentation andcontrol in mechanical engineering This second volume of Mechanical Engineers' Handbookcovers electronics, MEMS, and instrumentation and control, givingyou accessible and in-depth access to the topics you'll encounterin the discipline: computer-aided design, product design formanufacturing and assembly, design optimization, total qualitymanagement in mechanical system design, reliability in themechanical design process for sustainability, life-cycle design,design for remanufacturing processes, signal processing, dataacquisition and dis

  7. Comparison of our self-designed rotary self-locking intramedullary nail and interlocking intramedullary nail in the treatment of long bone fractures.

    Science.gov (United States)

    Liu, Bailian; Xiong, Ying; Deng, Hong; Gu, Shao; Jia, Fu; Li, Qunhui; Wang, Daxing; Gan, Xuewen; Liu, Wei

    2014-07-21

    The purpose of this study is to compare the clinical effects of our self-designed rotary self-locking intramedullary nail (RSIN) and interlocking intramedullary nail (IIN) for long bone fractures. A retrospective study was performed in 1,704 patients who suffered bone fractures and underwent RSIN or IIN operation in our hospital between March 1999 and March 2013, including 494 with femoral fractures, 572 with humeral fractures, and 638 with tibial fractures. Among them, 634 patients were followed up for more than 1 year. The operative time, intraoperative blood loss, postoperative complications, healing rate, and the excellent and good rate of functional recovery were compared between two groups. Compared with IIN group, RSIN group exhibited significantly shorter operative time and less intraoperative blood loss no matter for humeral, femoral, or tibial fractures (all p fractures (both p fracture. In IIN group, nail breakage or loosening occurred in 7 patients with femoral fractures and 16 patients with tibial fractures, radial nerve injury was observed in 8 patients with humeral fractures, and incision infection was present in 2 patients with humeral fractures and 1 patient with femoral fracture. The complication rate of IIN group was significantly higher than that of RSIN group (p knee, and ankle joint functional recovery between RSIN group and IIN group. RSIN may be a reliable and practical alternative method for the treatment of long bone fractures.

  8. Design of embedded control systems

    National Research Council Canada - National Science Library

    Adamski, M; Karatkevich, Andrei; Węgrzyn, M

    2005-01-01

    ... using some concrete technological base; efficient methods of logic synthesis, test, and verification should be developed for that. Fourth, the task of the communication between the control device and controlled objects (and maybe between different control devices) waits for its solution. All these problems are hard enough and cannot be successfull...

  9. Experimental Investigation of Damage and Fracture Mechanisms Controlling the Performance of Full Aperture Easy Open Ends for Food Containers

    Science.gov (United States)

    Taylor, D. L. P.; Nagy, G. T.; Owen, D. R. J.

    2011-05-01

    Can manufacturers produce hundreds of millions of cans annually, increasingly, food cans are being opened by lifting a tab on the can end that initiates a fracture, which then propagates around a circumferential score. The damage and fracture mechanisms that lead to crack initiation and propagation in the opening process, however, are not fully understood, therefore optimisation of easy open end scores is largely based on trial and error. This paper presents an experimental analysis that concentrates on the combined shear and bending forces as applied to the particular industrial method concerning full aperture easy open ends. The influence of a gradually increasing gap measured between the score and shear force location on traditional groove geometries and depths are examined for two different packaging steels. Earlier studies have shown that the complete opening cycle depends on fracture modes I, II & III as well as their combination. Experimental results for Modes I, II & III will be presented, however attention will focus on the behaviour of the initial fracture point, whereby prior investigations have shown it to be influenced primarily by mode II shearing. After initial specimen manufacture, where the score is formed by pressing a punch into a thin steel sheet the predeformed scored specimens are loaded in shear to simulate the local stress field found during the initial opening phase. Experiments have been completed using a novel Mode II experimental technique that has been designed for use in the majority of commercially available tensile test machines. Experimental results indicate that opening forces can change radically with different gap sizes and that there is considerable potential for the industrialised process of can end manufacture to be optimised through the efficient management and control of the can ends dimensional parameters.

  10. Dynamic plantar pressure distribution, strength capacity and postural control after Lisfranc fracture-dislocation

    DEFF Research Database (Denmark)

    Mehlhorn, Alexander T; Walther, Markus; Yilmaz, Tayfun

    2017-01-01

    of life. 17 consecutive patients suffering from a Lisfranc fracture dislocation were registered, underwent open reduction and internal fixation and were followed-up for 50.5±25.7months (Mean±SDM). Biomechanical analysis of muscle strength capacities, postural control and plantar pressure distribution......Substantial progress has been made in the operative treatment of Lisfranc fractures, however, the prognosis remains poor. We hypothesized that Lisfranc injuries change the postural control and muscle strength of the lower limb. Both are suggested to correlate with the clinical outcome and quality...... correlated well with clinical outcome. Altered postural control was evident by a significant reduction in unilateral stance time, from which we calculated a strong correlation between stance time and the isokinetic strength measurement. Plantar pressure measurements revealed a significant reduction in peak...

  11. Design Characteristics of Soft Control for APR+

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yongsoo; Sung, Chanho; Jung, Yeonsub [KHNP CRI, Daejeon (Korea, Republic of)

    2016-10-15

    In the global nuclear industry, the design requirements have been largely divided into the US and the European ones. The APR+ design, based on the proven APR1400 design, was developed to fully comply with the US regulatory and utility requirements. It was also developed to improve the technical competitiveness and enlarge the export market share through design uniqueness and the improvement of safety. The robust design of safety and its validation were requested Post-Fukushima accident. So MMIS design and validation for reinforcing safety were accomplished in APR+ development project. In this paper, the design characteristics of soft control for APR+ are presented to enhance the safety of MMIS design. In this paper, the major design characteristics of soft control for APR+ were introduced to increase the safety of MMIS design. In addition to the design characteristics of soft control described above, the following should be investigated closely for APR+ to get into the global nuclear industry.

  12. Design Characteristics of Soft Control for APR+

    International Nuclear Information System (INIS)

    Kim, Yongsoo; Sung, Chanho; Jung, Yeonsub

    2016-01-01

    In the global nuclear industry, the design requirements have been largely divided into the US and the European ones. The APR+ design, based on the proven APR1400 design, was developed to fully comply with the US regulatory and utility requirements. It was also developed to improve the technical competitiveness and enlarge the export market share through design uniqueness and the improvement of safety. The robust design of safety and its validation were requested Post-Fukushima accident. So MMIS design and validation for reinforcing safety were accomplished in APR+ development project. In this paper, the design characteristics of soft control for APR+ are presented to enhance the safety of MMIS design. In this paper, the major design characteristics of soft control for APR+ were introduced to increase the safety of MMIS design. In addition to the design characteristics of soft control described above, the following should be investigated closely for APR+ to get into the global nuclear industry

  13. Control room and ergonomic design

    International Nuclear Information System (INIS)

    Hinz, W.

    1984-01-01

    The important basis for the configuration of the control room of a nuclear power station is the concept for controlling a fault and that for controlling normal operation. The tasks resulting from this for the control room personnel are decided by the control room concept. In this configuration process (from the division of process control tasks between the system components operators and control technology to the configuration of individual means of operation) the characteristics and capabilities of the personnel, which are subject to special requirements as regards their qualifications, are observed. New concepts which are only now technically feasible are therefore being developed for information processing and display, in order to give the personnel a better oversight of the state and trends of the plant. (orig./DG) [de

  14. Use of organic nitrates and the risk of hip fracture: a population-based case-control study.

    Science.gov (United States)

    Pouwels, Sander; Lalmohamed, Arief; van Staa, Tjeerd; Cooper, Cyrus; Souverein, Patrick; Leufkens, Hubertus G; Rejnmark, Lars; de Boer, Anthonius; Vestergaard, Peter; de Vries, Frank

    2010-04-01

    Use of organic nitrates has been associated with increased bone mineral density. Moreover, a large Danish case-control study reported a decreased fracture risk. However, the association with duration of nitrate use, dose frequency, and impact of discontinuation has not been extensively studied. Our objective was to evaluate the association between organic nitrates and hip fracture risk. A case-control study was conducted using the Dutch PHARMO Record Linkage System (1991-2002, n = 6,763 hip fracture cases and 26,341 controls). Cases had their first admission for hip fracture, whereas controls had not sustained any fracture after enrollment. Current users of organic nitrates were patients who had received a prescription within 90 d before the index date. The analyses were adjusted for disease and drug history. Current use of nitrates was not associated with a decreased risk of hip fracture [adjusted odds ratio (OR) = 0.93; 95% confidence interval (CI) = 0.83-1.04]. Those who used as-needed medication only had a lower risk of hip fracture (adjusted OR = 0.83; 95% CI = 0.63-1.08) compared with users of maintenance medication only (adjusted OR = 1.17; 95% CI = 0.97-1.40). No association was found between duration of nitrate use and fracture risk. Our overall analyses showed that risk of a hip fracture was significantly lower among users of as-needed organic nitrates, when compared with users of maintenance medication. Our analyses of hip fracture risks with duration of use did not further support a beneficial effect of organic nitrates on hip fracture, although residual confounding may have masked beneficial effects.

  15. Cross-education for improving strength and mobility after distal radius fractures: a randomized controlled trial.

    Science.gov (United States)

    Magnus, Charlene R A; Arnold, Cathy M; Johnston, Geoffrey; Dal-Bello Haas, Vanina; Basran, Jenny; Krentz, Joel R; Farthing, Jonathan P

    2013-07-01

    To evaluate the effects of cross-education (contralateral effect of unilateral strength training) during recovery from unilateral distal radius fractures on muscle strength, range of motion (ROM), and function. Randomized controlled trial (26-wk follow-up). Hospital, orthopedic fracture clinic. Women older than 50 years with a unilateral distal radius fracture. Fifty-one participants were randomized and 39 participants were included in the final data analysis. Participants were randomized to standard rehabilitation (Control) or standard rehabilitation plus strength training (Train). Standard rehabilitation included forearm casting for 40.4±6.2 days and hand exercises for the fractured extremity. Nonfractured hand strength training for the training group began immediately postfracture and was conducted at home 3 times/week for 26 weeks. The primary outcome measure was peak force (handgrip dynamometer). Secondary outcomes were ROM (flexion/extension; supination/pronation) via goniometer and the Patient Rated Wrist Evaluation questionnaire score for the fractured arm. For the fractured hand, the training group (17.3±7.4kg) was significantly stronger than the control group (11.8±5.8kg) at 12 weeks postfracture (P<.017). There were no significant strength differences between the training and control groups at 9 (12.5±8.2kg; 11.3±6.9kg) or 26 weeks (23.0±7.6kg; 19.6±5.5kg) postfracture, respectively. Fractured hand ROM showed that the training group had significantly improved wrist flexion/extension (100.5°±19.2°) than the control group (80.2°±18.7°) at 12 weeks postfracture (P<.017). There were no significant differences between the training and control groups for flexion/extension ROM at 9 (78.0°±20.7°; 81.7°±25.7°) or 26 weeks (104.4°±15.5°; 106.0°±26.5°) or supination/pronation ROM at 9 (153.9°±23.9°; 151.8°±33.0°), 12 (170.9°±9.3°; 156.7°±20.8°) or 26 weeks (169.4°±11.9°; 162.8°±18.1°), respectively. There were no

  16. Fracturing Fluid Leak-off for Deep Volcanic Rock in Zhungeer Basin: Mechanism and Control Method

    OpenAIRE

    Huang Bo; Cheng Hao; He Yidong; Fu Yanming

    2017-01-01

    The deep volcanic reservoir in Zhungeer Basin is buried in over 4000m depth, which is characterized by complex lithology (breccia, andesite, basalt, etc.), high elastic modulus and massive natural fractures. During hydraulic fracturing, hydraulic fracture will propagate and natural fractures will be triggered by the increasing net pressure. However, the extension of fractures, especially natural fractures, would aggravate the leak-off effect of fracturing fluid, and consequently decrease the ...

  17. 21 CFR 820.30 - Design controls.

    Science.gov (United States)

    2010-04-01

    ... QUALITY SYSTEM REGULATION Design Controls § 820.30 Design controls. (a) General. (1) Each manufacturer of...) Devices automated with computer software; and (ii) The devices listed in the following chart. Section... in, input to the design and development process. The plans shall be reviewed, updated, and approved...

  18. Post-discharge management following hip fracture - get you back to B4: A parallel group, randomized controlled trial study protocol

    Directory of Open Access Journals (Sweden)

    Brown Roy A

    2011-06-01

    Full Text Available Abstract Background Fall-related hip fractures result in significant personal and societal consequences; importantly, up to half of older adults with hip fracture never regain their previous level of mobility. Strategies of follow-up care for older adults after fracture have improved investigation for osteoporosis; but managing bone health alone is not enough. Prevention of fractures requires management of both bone health and falls risk factors (including the contributing role of cognition, balance and continence to improve outcomes. Methods/Design This is a parallel group, pragmatic randomized controlled trial to test the effectiveness of a post-fracture clinic compared with usual care on mobility for older adults following their hospitalization for hip fracture. Participants randomized to the intervention will attend a fracture follow-up clinic where a geriatrician and physiotherapist will assess and manage their mobility and other health issues. Depending on needs identified at the clinical assessment, participants may receive individualized and group-based outpatient physiotherapy, and a home exercise program. Our primary objective is to assess the effectiveness of a novel post-discharge fracture management strategy on the mobility of older adults after hip fracture. We will enrol 130 older adults (65 years+ who have sustained a hip fracture in the previous three months, and were admitted to hospital from home and are expected to be discharged home. We will exclude older adults who prior to the fracture were: unable to walk 10 meters; diagnosed with dementia and/or significant comorbidities that would preclude their participation in the clinical service. Eligible participants will be randomly assigned to the Intervention or Usual Care groups by remote allocation. Treatment allocation will be concealed; investigators, measurement team and primary data analysts will be blinded to group allocation. Our primary outcome is mobility

  19. LWR control assembly designs: A historical perspective

    International Nuclear Information System (INIS)

    Kennard, M.W.; Harbottle, J.E.

    2000-01-01

    Control rod designs and materials have evolved in response to performance problems in both PWRs and BWRs. Irradiation-assisted stress corrosion cracking (IASCC) due to absorber swelling has primarily affected BWR control rods with B 4 C absorbers, but has also occurred in PWRs with Ag-In-Cd absorbers. The primary problems for some designs of PWR control rods have been wear of the rodlets against upper internal components and swelling with tip wear and cracking. Competition amongst vendors for supplying control rod reloads has also resulted in design improvements. This paper provides an historical review of PWR and BWR control rod designs, their problems and remedies. (author)

  20. Regulatory control of fuel design and manufacturing

    International Nuclear Information System (INIS)

    1994-01-01

    The regulatory control of the design and manufacturing of the nuclear fuel and of the control rods aims to ensure conformance to set requirements during normal operating conditions, anticipated operational transients and postulated accident conditions. The regulatory control of design, manufacturing, receiving inspections and the start of operation of the nuclear fuel are specified in the guide. The regulatory control procedure also applies to the control rods and the shield elements

  1. ACSYNT inner loop flight control design study

    Science.gov (United States)

    Bortins, Richard; Sorensen, John A.

    1993-01-01

    The NASA Ames Research Center developed the Aircraft Synthesis (ACSYNT) computer program to synthesize conceptual future aircraft designs and to evaluate critical performance metrics early in the design process before significant resources are committed and cost decisions made. ACSYNT uses steady-state performance metrics, such as aircraft range, payload, and fuel consumption, and static performance metrics, such as the control authority required for the takeoff rotation and for landing with an engine out, to evaluate conceptual aircraft designs. It can also optimize designs with respect to selected criteria and constraints. Many modern aircraft have stability provided by the flight control system rather than by the airframe. This may allow the aircraft designer to increase combat agility, or decrease trim drag, for increased range and payload. This strategy requires concurrent design of the airframe and the flight control system, making trade-offs of performance and dynamics during the earliest stages of design. ACSYNT presently lacks means to implement flight control system designs but research is being done to add methods for predicting rotational degrees of freedom and control effector performance. A software module to compute and analyze the dynamics of the aircraft and to compute feedback gains and analyze closed loop dynamics is required. The data gained from these analyses can then be fed back to the aircraft design process so that the effects of the flight control system and the airframe on aircraft performance can be included as design metrics. This report presents results of a feasibility study and the initial design work to add an inner loop flight control system (ILFCS) design capability to the stability and control module in ACSYNT. The overall objective is to provide a capability for concurrent design of the aircraft and its flight control system, and enable concept designers to improve performance by exploiting the interrelationships between

  2. Subtrochanteric femoral fractures treated with the Long Gamma3® nail: A historical control case study versus Long trochanteric Gamma nail®.

    Science.gov (United States)

    Georgiannos, D; Lampridis, V; Bisbinas, I

    2015-10-01

    Gamma nail was developed for the treatment of subtrochanteric hip fractures. Despite its advantages over extramedullary devices, gamma nail has been historically related to significant complications (implant breakage, femoral fractures at the tip of the nail). There is limited data to determine if the rate of these complications was minimized by using a new design of the gamma nail. Therefore we performed a case control study between the long gamma3 nail (LG3N) and the long trochanteric gamma nail (LTGN) to assess if: (1) the complication rate in the treatment of subtrochanteric fractures using the LG3N was lower than the one using the LTGN; (2) the reoperation rate was lower after using the LG3N. The complication rate after fixation of subtrochanteric fracture of the femur is lower with LG3N than with the LTGN. This study prospectively recorded the intra- and postoperative complications of 75 patients with subtrochanteric fractures treated with the LG3N and compared them with those of a historical cohort of 83 patients treated with the LTGN. The two groups were matched regarding age, gender and fracture type. Patients with open, pathological, or impending fractures were excluded. Intraoperative complications in the LG3N group were lower (4 cases, 5.3%) compared with those in the LTGN group (9 cases, 10.8%; P=0.04). The major intraoperative complication encountered with the use of LTGN was fracture of the femur in 3 cases. We encountered in total 9 postoperative complications in LG3N (12%) and 20 in group LTGN (24%). The most frequent complication in both groups was the cut out of the lag screw (3 cases in LG3N and 7 cases in LTGN group). The overall reoperation rate was higher in LTGN group (20.4% vs 10.6%; P=0.03). As a result of the improvement of its mechanical characteristics, LG3N has proved a safe and efficient implant for the treatment of subtochanteric fractures. The new design seems superior to previous generation, giving promising outcomes, reduced

  3. Controller design for Robotic hand through Electroencephalogram

    OpenAIRE

    Pandelidis P.; Kiriazis N.; Orgianelis K.; Koulios N.

    2016-01-01

    - This paper deals with the designing, the construction and the control of a robotic hand via an electroencephalogram sensor. First a robotic device that is able to mimic a real human hand is constructed. A PID controller is designed in order to improve the performance of the robotic arm for grabbing objects. Furthermore, a novel design approach is presented for controlling the motion of the robotic arm using signals produced from an innovative electroencephalogram sensor that detects the con...

  4. Fracture mechanics of ceramics. Vol. 8. Microstructure, methods, design, and fatigue

    International Nuclear Information System (INIS)

    Bradt, R.C.; Evans, A.G.; Hasselman, D.P.H.; Lange, F.F.

    1986-01-01

    This paper presents information on the following topics: fracture mechanics and microstructures; non-lubricated sliding wear of Al 2 O 3 , PSZ and SiC; mixed-mode fracture of ceramics; some fracture properties of alumina-containing electrical porcelains; transformation toughening in the Al 2 O 3 -Cr 2 O 3 /ZrO 2 -HfO 2 system; strength toughness relationships for transformation toughened ceramics; tensile strength and notch sensitivity of Mg-PSZ; fracture mechanisms in lead zirconate titanate ceramics; loading-unloading techniques for determining fracture parameters of brittle materials utilizing four-point bend, chevron-notched specimens; application of the potential drop technique to the fracture mechanics of ceramics; ceramics-to-metal bonding from a fracture mechanics perspective; observed changes in fracture strength following laser irradiation and ion beam mixing of Ni overlayers on sintered alpha-SiC; crack growth in single-crystal silicon; a fracture mechanics and non-destructive evaluation investigation of the subcritical-fracture process in rock; slow crack growth in sintered silicon nitride; uniaxial tensile fatigue testing of sintered silicon carbide under cyclic temperature change; and effect of surface corrosion on glass fracture

  5. Newly designed anterolateral and posterolateral locking anatomic plates for lateral tibial plateau fractures: a finite element study.

    Science.gov (United States)

    Chen, Pengbo; Lu, Hua; Shen, Hao; Wang, Wei; Ni, Binbin; Chen, Jishizhan

    2017-02-23

    Lateral column tibial plateau fracture fixation with a locking screw plate has higher mechanical stability than other fixation methods. The objectives of the present study were to introduce two newly designed locking anatomic plates for lateral tibial plateau fracture and to demonstrate their characteristics of the fixation complexes under the axial loads. Three different 3D finite element models of the lateral tibial plateau fracture with the bone plates were created. Various axial forces (100, 500, 1000, and 1500 N) were applied to simulate the axial compressive load on an adult knee during daily life. The equivalent maps of displacement and stress were output, and relative displacement was calculated along the fracture lines. The displacement and stresses in the fixation complexes increased with the axial force. The equivalent displacement or stress map of each fixation under different axial forces showed similar distributing characteristics. The motion characteristics of the three models differed, and the max-shear stress of trabecula increased with the axial load. These two novel plates could fix lateral tibial plateau fractures involving anterolateral and posterolateral fragments. Motions after open reduction and stable internal fixation should be advised to decrease the risk of trabecular microfracture. The relative displacement of the posterolateral fragments is different when using anterolateral plate and posterolateral plate, which should be considered in choosing the implants for different posterolateral plateau fractures.

  6. Design controls for the medical device industry

    CERN Document Server

    Teixeira, Marie B

    2013-01-01

    The second edition of a bestseller, Design Controls for the Medical Device Industry provides a comprehensive review of the latest design control requirements, as well as proven tools and techniques to ensure your company's design control program evolves in accordance with current industry practice. The text assists in the development of an effective design control program that not only satisfies the US FDA Quality System Regulation (QSR) and ISO 9001 and 13485 standards, but also meets today's third-party auditor/investigator expectations and saves you valuable time and money.The author's cont

  7. Effectiveness of joint mobilisation after cast immobilisation for ankle fracture: a protocol for a randomised controlled trial [ACTRN012605000143628

    Directory of Open Access Journals (Sweden)

    Haas Marion

    2006-05-01

    Full Text Available Abstract Background Passive joint mobilisation is a technique frequently used by physiotherapists to reduce pain, improve joint movement and facilitate a return to activities after injury, but its use after ankle fracture is currently based on limited evidence. The primary aim of this trial is to determine if adding joint mobilisation to a standard exercise programme is effective and cost-effective after cast immobilisation for ankle fracture in adults. Methods/Design Ninety participants will be recruited from the physiotherapy departments of three teaching hospitals and randomly allocated to treatment or control groups using a concealed procedure. All participants will perform an exercise programme. Participants in the treatment group will also receive joint mobilisation twice a week for four weeks. Blinded follow-up assessments will be conducted four, 12 and 24 weeks after randomisation. The primary outcome measures will be the Lower Extremity Functional Scale and the Assessment of Quality of Life. Secondary outcomes will include measures of impairments, activity limitation and participation. Data on the use of physiotherapy services and participants' out-of-pocket costs will be collected for the cost-effective and cost-utility analyses. To test the effects of treatment, between-group differences will be examined with analysis of covariance using a regression approach. The primary conclusions will be based on the four-week follow-up data. Discussion This trial incorporates features known to minimise bias. It uses a pragmatic design to reflect clinical practice and maximise generalisability. Results from this trial will contribute to an evidence-based approach for rehabilitation after ankle fracture.

  8. Method for control-room display design

    International Nuclear Information System (INIS)

    Montmayeul, R.

    1988-01-01

    This document describes a method for control-room displays design. It can be used either for isolated display to add to an existing system either for the design of a full system of operator aids. The method is a top-down design with steps of possible iteration. The emphasis is put on display design rather than on system design; system aspects are just mentioned. Advantages of using a method are described [fr

  9. Ares I Flight Control System Design

    Science.gov (United States)

    Jang, Jiann-Woei; Alaniz, Abran; Hall, Robert; Bedrossian, Nazareth; Hall, Charles; Ryan, Stephen; Jackson, Mark

    2010-01-01

    The Ares I launch vehicle represents a challenging flex-body structural environment for flight control system design. This paper presents a design methodology for employing numerical optimization to develop the Ares I flight control system. The design objectives include attitude tracking accuracy and robust stability with respect to rigid body dynamics, propellant slosh, and flex. Under the assumption that the Ares I time-varying dynamics and control system can be frozen over a short period of time, the flight controllers are designed to stabilize all selected frozen-time launch control systems in the presence of parametric uncertainty. Flex filters in the flight control system are designed to minimize the flex components in the error signals before they are sent to the attitude controller. To ensure adequate response to guidance command, step response specifications are introduced as constraints in the optimization problem. Imposing these constraints minimizes performance degradation caused by the addition of the flex filters. The first stage bending filter design achieves stability by adding lag to the first structural frequency to phase stabilize the first flex mode while gain stabilizing the higher modes. The upper stage bending filter design gain stabilizes all the flex bending modes. The flight control system designs provided here have been demonstrated to provide stable first and second stage control systems in both Draper Ares Stability Analysis Tool (ASAT) and the MSFC 6DOF nonlinear time domain simulation.

  10. A metamorphic controller for plant control system design

    Directory of Open Access Journals (Sweden)

    Tomasz Klopot

    2016-07-01

    Full Text Available One of the major problems in the design of industrial control systems is the selection and parameterization of the control algorithm. In practice, the most common solution is the PI (proportional-integral controller, which is simple to implement, but is not always the best control strategy. The use of more advanced controllers may result in a better efficiency of the control system. However, the implementation of advanced control algorithms is more time-consuming and requires specialized knowledge from control engineers. To overcome these problems and to support control engineers at the controller design stage, the paper describes a tool, i.e., a metamorphic controller with extended functionality, for selection and implementation of the most suitable control algorithm. In comparison to existing solutions, the main advantage of the metamorphic controller is its possibility of changing the control algorithm. In turn, the candidate algorithms can be tested through simulations and the total time needed to perform all simulations can be less than a few minutes, which is less than or comparable to the design time in the concurrent design approach. Moreover, the use of well-known tuning procedures, makes the system easy to understand and operate even by inexperienced control engineers. The application was implemented in the real industrial programmable logic controller (PLC and tested with linear and nonlinear virtual plants. The obtained simulation results confirm that the change of the control algorithm allows the control objectives to be achieved at lower costs and in less time.

  11. [Effect of pneumatic compression in connection with ergotherapeutic treatment of Colles' fracture. A clinical controlled trial].

    Science.gov (United States)

    Svensson, B H; Frellsen, M B; Basse, P N; Bliddal, H; Caspers, J; Parby, K

    1993-02-15

    We followed forty women with functional deficits in the wrist and hand after sustaining a Colles' fracture. The women participated in occupational therapy three times a week for three weeks. At the initial evaluation, after three weeks, and at a three month evaluation, we measured the following: range of joint movement, grip strength, hand volume (oedema), pain and ADL. There was significant improvement in most of the parameters measured after three weeks of occupational therapy, with a less significant improvement from three weeks to three months. Seventeen of the forty women received twenty minutes of intermittent pneumatic compression before occupational therapy. These patients showed significant improvement in wrist extension, compared with the control group of twenty-three patients. Occupational therapy is recommended for patients showing a functional deficit after Colles' fracture. Intermittent pneumatic compression is recommended as a supplement to occupational therapy.

  12. Geophysical signatures of a fracture controlled U-mineralisation: a case study from Mulapalle area, Cuddapah district, Andhra Pradesh

    International Nuclear Information System (INIS)

    Rao, R.L.N.; Sethuram, S.; Rao, B.N.; Tiku, K.L.; Ram, Subhash

    2000-01-01

    Geophysical methods have been extensively used for delineation of structural features such as fractures and shear zones which often control and host economic mineralisation. Numerous fractures hosting uranium mineralisation and confined to younger intrusives and leucogranites occur within basement gneissic complex on the southwestern margin of the Mesoproterozoic Cuddapah basin. The geophysical signatures of one such mineralised fracture zone near Mulapalle are discussed. Mineralised fractures are mostly confined to a zone of cataclastic rocks characterised by widely varying magnetic character with respect to the surroundings. A strong redox barrier associated with the mineralisation is revealed by self-potential data. The mineralised zone is also indicated by a higher order resistivity attributable to the enrichment of silica in the fracture zone. (author)

  13. Dynamic optimization and adaptive controller design

    Science.gov (United States)

    Inamdar, S. R.

    2010-10-01

    In this work I present a new type of controller which is an adaptive tracking controller which employs dynamic optimization for optimizing current value of controller action for the temperature control of nonisothermal continuously stirred tank reactor (CSTR). We begin with a two-state model of nonisothermal CSTR which are mass and heat balance equations and then add cooling system dynamics to eliminate input multiplicity. The initial design value is obtained using local stability of steady states where approach temperature for cooling action is specified as a steady state and a design specification. Later we make a correction in the dynamics where material balance is manipulated to use feed concentration as a system parameter as an adaptive control measure in order to avoid actuator saturation for the main control loop. The analysis leading to design of dynamic optimization based parameter adaptive controller is presented. The important component of this mathematical framework is reference trajectory generation to form an adaptive control measure.

  14. Hollow Abutment Screw Design for Easy Retrieval in Case of Screw Fracture in Dental Implant System

    OpenAIRE

    Sim, Bo Kyun; Kim, Bongju; Kim, Min Jeong; Jeong, Guk Hyun; Ju, Kyung Won; Shin, Yoo Jin; Kim, Man Yong; Lee, Jong-Ho

    2017-01-01

    The prosthetic component of dental implant is attached on the abutment which is connected to the fixture with an abutment screw. The abutment screw fracture is not frequent; however, the retrieval of the fractured screw is not easy, and it poses complications. A retrieval kit was developed which utilizes screw removal drills to make a hole on the fractured screw that provides an engaging drill to unscrew it. To minimize this process, the abutment screw is modified with a prefabricated access ...

  15. Fracture resistance and failure modes of polymer infiltrated ceramic endocrown restorations with variations in margin design and occlusal thickness.

    Science.gov (United States)

    Taha, Doaa; Spintzyk, Sebastian; Schille, Christine; Sabet, Ahmed; Wahsh, Marwa; Salah, Tarek; Geis-Gerstorfer, Jürgen

    2017-12-11

    The purpose of this in vitro study was to assess the effect of varying the margin designs and the occlusal thicknesses on the fracture resistance and mode of failures of endodontically treated teeth restored with polymer infiltrated ceramic endocrown restorations. Root canal treated mandibular molars were divided into four groups (n=8) and were prepared to receive Computer-Aided Design/Computer-Aided Manufacturing (CAD/CAM) fabricated polymer infiltrated ceramic endocrowns (ENAMIC blocks). Group B2 represents teeth prepared with a butt joint design receiving endocrowns with 2mm occlusal thickness and the same for group B3.5 but with 3.5mm occlusal thickness. Group S2 represents teeth prepared with 1mm shoulder finish line receiving endocrowns with 2mm occlusal thickness and the same for group S3.5 but with 3.5mm occlusal thickness. After cementation and thermal aging, fracture resistance test was performed and failure modes were observed. Group S3.5 showed the highest mean fracture load value (1.27±0.31kN). Endocrowns with shoulder finish line had significantly higher mean fracture resistance values than endocrowns with butt margin (p<0.05). However, the results were not statistically significant regarding the restoration thickness. Evaluation of the fracture modes revealed no statistically significant difference between the modes of failure of tested groups. For the restoration of endodontically treated teeth, adding a short axial wall and shoulder finish line can increase the fracture resistance. However, further investigations, especially the fatigue behavior, are needed to ensure this effect applies with small increases of restoration thickness. Copyright © 2017 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

  16. The important role of martensite laths to fracture toughness for the ductile fracture controlled by the strain in EA4T axle steel

    International Nuclear Information System (INIS)

    Liang, Yilong; Long, Shaolei; Xu, Pingwei; Lu, Yemao; Jiang, Yun; Liang, Yu; Yang, Ming

    2017-01-01

    The Hall-Petch relationship was used to investigate the role of martensite lath on fracture toughness (K IC ) during ductile fracture in a low-carbon EA4T axle steel. The hierarchical structures of lath martensite was clarified by means of optical microscope (OM), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM) and electron backscattering diffraction (EBSD). Firstly, in such hierarchical structures, packet size (d p ) and block size (d b ) increase significantly with the size of prior austenite (d r ), while the martensite lath width (d l ) decreases. Subsequently, K IC was measured and follows the Hall-Petch relationship with d l . It depends on the rotation, bending and direct shear during crack propagation of laths, confirmed by EBSD. Besides, fracture toughness (K IC ) is proportional to a parameter ε v , the matrix strain, which is related to the plastic deformation of laths. Therefore, the martensite lath in hierarchical structures is the effective control unit of K IC during ductile fracture controlled by the strain.

  17. The important role of martensite laths to fracture toughness for the ductile fracture controlled by the strain in EA4T axle steel

    Energy Technology Data Exchange (ETDEWEB)

    Liang, Yilong, E-mail: liangyilong@126.com [College of Materials Science and Metallurgical Engineering, Guizhou University (China); Guizhou key Laboratory for Mechanical Behavior and Microstructure of Materials (China); National & Local Joint Engineering Laboratory for High-performance Metal Structure Material and Advanced Manufacturing Technology (China); Long, Shaolei; Xu, Pingwei; Lu, Yemao [College of Materials Science and Metallurgical Engineering, Guizhou University (China); Guizhou key Laboratory for Mechanical Behavior and Microstructure of Materials (China); National & Local Joint Engineering Laboratory for High-performance Metal Structure Material and Advanced Manufacturing Technology (China); Jiang, Yun [Guizhou key Laboratory for Mechanical Behavior and Microstructure of Materials (China); National & Local Joint Engineering Laboratory for High-performance Metal Structure Material and Advanced Manufacturing Technology (China); Liang, Yu; Yang, Ming [College of Materials Science and Metallurgical Engineering, Guizhou University (China); Guizhou key Laboratory for Mechanical Behavior and Microstructure of Materials (China); National & Local Joint Engineering Laboratory for High-performance Metal Structure Material and Advanced Manufacturing Technology (China)

    2017-05-17

    The Hall-Petch relationship was used to investigate the role of martensite lath on fracture toughness (K{sub IC}) during ductile fracture in a low-carbon EA4T axle steel. The hierarchical structures of lath martensite was clarified by means of optical microscope (OM), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM) and electron backscattering diffraction (EBSD). Firstly, in such hierarchical structures, packet size (d{sub p}) and block size (d{sub b}) increase significantly with the size of prior austenite (d{sub r}), while the martensite lath width (d{sub l}) decreases. Subsequently, K{sub IC} was measured and follows the Hall-Petch relationship with d{sub l}. It depends on the rotation, bending and direct shear during crack propagation of laths, confirmed by EBSD. Besides, fracture toughness (K{sub IC}) is proportional to a parameter ε{sub v}, the matrix strain, which is related to the plastic deformation of laths. Therefore, the martensite lath in hierarchical structures is the effective control unit of K{sub IC} during ductile fracture controlled by the strain.

  18. Fracture propagation in gas pipelines - relevance to submarine lines

    Energy Technology Data Exchange (ETDEWEB)

    Fearnehough, G D [British Gas Corp., Newcastle upon Tyne. Engineering Research Station

    1976-09-01

    This paper reviews the factors which control fracture propagation in pipes and suggests how they are influenced by submarine environments. If fracture arrest capability is required then these factors should be considered in terms of the design philosophy and the maximum tolerable length of fracture which can be repaired. The paper shows that brittle fracture characteristics of submarine pipelines are probably similar to land based lines and fracture arrest can only be guaranteed by appropriate material toughness specification. Resistance to ductile fracture propagation in submarine lines is enhanced by lower design stresses, thicker pipe, concrete coating and the effect of hydrostatic head on gas dynamics. However, additional factors due to submarine design can be deleterious viz: uncertainty about backfill integrity and a tendency of thicker steels to low fracture resistance arising from 'separation' formation. Attention is drawn to problems which may arise with transportation of gases rich in hydrocarbons and the use of mechanical methods of fracture arrest.

  19. Comprehensive geriatric care for patients with hip fractures: a prospective, randomised, controlled trial.

    Science.gov (United States)

    Prestmo, Anders; Hagen, Gunhild; Sletvold, Olav; Helbostad, Jorunn L; Thingstad, Pernille; Taraldsen, Kristin; Lydersen, Stian; Halsteinli, Vidar; Saltnes, Turi; Lamb, Sarah E; Johnsen, Lars G; Saltvedt, Ingvild

    2015-04-25

    Most patients with hip fractures are characterised by older age (>70 years), frailty, and functional deterioration, and their long-term outcomes are poor with increased costs. We compared the effectiveness and cost-effectiveness of giving these patients comprehensive geriatric care in a dedicated geriatric ward versus the usual orthopaedic care. We did a prospective, single-centre, randomised, parallel-group, controlled trial. Between April 18, 2008, and Dec 30, 2010, we randomly assigned home-dwelling patients with hip-fractures aged 70 years or older who were able to walk 10 m before their fracture, to either comprehensive geriatric care or orthopaedic care in the emergency department, to achieve the required sample of 400 patients. Randomisation was achieved via a web-based, computer-generated, block method with unknown block sizes. The primary outcome, analysed by intention to treat, was mobility measured with the Short Physical Performance Battery (SPPB) 4 months after surgery for the fracture. The type of treatment was not concealed from the patients or staff delivering the care, and assessors were only partly masked to the treatment during follow-up. This trial is registered with ClinicalTrials.gov, number NCT00667914. We assessed 1077 patients for eligibility, and excluded 680, mainly for not meeting the inclusion criteria such as living in a nursing home or being aged less than 70 years. Of the remaining patients, we randomly assigned 198 to comprehensive geriatric care and 199 to orthopaedic care. At 4 months, 174 patients remained in the comprehensive geriatric care group and 170 in the orthopaedic care group; the main reason for dropout was death. Mean SPPB scores at 4 months were 5·12 (SE 0·20) for comprehensive geriatric care and 4·38 (SE 0·20) for orthopaedic care (between-group difference 0·74, 95% CI 0·18-1·30, p=0·010). Immediate admission of patients aged 70 years or more with a hip fracture to comprehensive geriatric care in a dedicated

  20. The study and design of tension controller

    Science.gov (United States)

    Jun, G.; Lamei, X.

    2018-02-01

    Tension control is a wide used technology in areas such as textiles, paper and plastic films. In this article, the tension control system release and winding process is analyzed and the mathematical model of tension control system is established, and a high performance tension controller is designed. In hardware design, STM32F130 single chip microcomputer is used as the control core, which has the characteristics of fast running speed and rich peripheral features. In software design, μC/OS-II operating system is introduced to improve the efficiency of single chip microcomputer, and enhance the independence of each module, and make development and maintenance more convenient. The taper tension control is adopted in the winding part, which can effectively solve the problem of rolling shrinkage. The results show that the tension controller has the characteristics of simple structure, easy operation and stable performance.

  1. Logical design for computers and control

    CERN Document Server

    Dodd, Kenneth N

    1972-01-01

    Logical Design for Computers and Control Logical Design for Computers and Control gives an introduction to the concepts and principles, applications, and advancements in the field of control logic. The text covers topics such as logic elements; high and low logic; kinds of flip-flops; binary counting and arithmetic; and Boolean algebra, Boolean laws, and De Morgan's theorem. Also covered are topics such as electrostatics and atomic theory; the integrated circuit and simple control systems; the conversion of analog to digital systems; and computer applications and control. The book is recommend

  2. Effect of extended physiotherapy and high-dose vitamin D on rate of falls and hospital re-admission after acute hip fracture: a randomized controlled trial

    Science.gov (United States)

    Guidelines for post-fracture care of elderly hip fracture patients are not established despite the significant socio-economic burden of post hip fracture morbidity and mortality. Using a factorial design, we studied the effects of extended physiotherapy (supervised 1 hour per day during acute care p...

  3. Hydraulically powered dissimilar teleoperated system controller design

    International Nuclear Information System (INIS)

    Jansen, J.F.; Kress, R.L.

    1996-01-01

    This paper will address two issues associated with the implementation of a hydraulically powered dissimilar master-slave teleoperated system. These issues are the overall system control architecture and the design of robust hydraulic servo controllers for the position control problem. Finally, a discussion of overall system performance on an actual teleoperated system will be presented

  4. Actuator topology design using the controllability Gramian

    DEFF Research Database (Denmark)

    Alves da Silveira, Otávio Augusto; Ono Fonseca, Jun Sérgio; Santos, Ilmar

    2015-01-01

    This work develops a methodology for the optimal design of actuators for the vibration control of flexible structures. The objective is the maximization of a measure of the controllability Gramian. The test case is the embedding of piezoelectric inserts in elastic structures for vibration control...

  5. Comparison of Marginal Fit and Fracture Strength of a CAD/CAM Zirconia Crown with Two Preparation Designs

    Directory of Open Access Journals (Sweden)

    Hamid Jalali

    2016-08-01

    Full Text Available Objectives: The purpose of this in vitro study was to compare the marginal adaptation and fracture resistance of a zirconia-based all-ceramic restoration with two preparation designs.Materials and Methods: Twenty-four mandibular premolars were randomly divided into two groups (n=12; the conventional group received a peripheral shoulder preparation and the modified group received a buccal shoulder and proximal/lingual chamfer preparation. The marginal fit of the zirconia crowns (Cercon was evaluated using a stereomicroscope. After cementation, load was applied to the crowns. The mean fracture load and the mean marginal gap for each group were analyzed using t-test (P=0.05.Results: The mean marginal gap was 71±16µm in the conventional group and 80±10µm in the modified group, with no significant difference (P=0.161. The mean fracture strength was 830±153N for the conventional group and 775±125N for the modified group, with no significant difference (P=0.396. All but one fracture occurred in the veneering ceramic.Conclusion: Less aggressive preparation of proximal and lingual finish lines for the preservation of tooth structure in all-ceramic restorations does not adversely affect the marginal adaptation or fracture strength of the final restoration.

  6. Designing a Prognostic Scoring System for Predicting the Outcomes of Proximal Fifth Metatarsal Fractures at 20 Weeks

    Directory of Open Access Journals (Sweden)

    Mohammad Ali Tahririan

    2015-03-01

    Full Text Available Background: Fractures of the proximal fifth metatarsal bone are among the most common fractures observed in the foot and their classification and management has been subject to much discussion and disagreement. In this study, we aim to identify and quantify the effect of possible predictors of the outcome of the treatment of proximal fifth metatarsal fractures. Methods: Patients with established proximal fifth metatarsal fractures were enrolled in this prospective cohort and the outcome of their treatment was assessed using the AOFAS mid foot scale at 6 and 20 weeks. Results: 143 patients were included in the study. Our study showed that displacement, weight and type III fractures were significant independent predictors of poor outcome at 6 weeks while at 20 weeks in addition to these factors, gender and diabetes mellitus were also shown to be significant independent predictors of poor outcome. A scoring system was designed by assigning weight to these factors and it was shown to be a strong predictor of outcome at 20 weeks. Conclusion: We recommend that our scoring system would help surgeons to decide whether patients’ prognostic factors are significant enough for him/her to opt for a surgical approach to treatment rather than a conservative approach.

  7. Application of genetic algorithm to control design

    International Nuclear Information System (INIS)

    Lee, Yoon Joon; Cho, Kyung Ho

    1995-01-01

    A classical PID controller is designed by applying the GA (Genetic Algorithm) which searches the optimal parameters through three major operators of reproduction, crossover and mutation under the given constraints. The GA could minimize the designer's interference and the whole design process could easily be automated. In contrast with other traditional PID design methods which allows for the system output responses only, the design with the GA can take account of the magnitude or the rate of change of control input together with the output responses, which reflects the more realistic situations. Compared with other PIDs designed by the traditional methods such as Ziegler and analytic, the PID by the GA shows the superior response characteristics to those of others with the least control input energy

  8. Protocol for the ProFHER (PROximal Fracture of the Humerus: Evaluation by Randomisation trial: a pragmatic multi-centre randomised controlled trial of surgical versus non-surgical treatment for proximal fracture of the humerus in adults

    Directory of Open Access Journals (Sweden)

    Maffulli Nicola

    2009-11-01

    Full Text Available Abstract Background Proximal humeral fractures, which occur mainly in older adults, account for approximately 4 to 5% of all fractures. Approximately 40% of these fractures are displaced fractures involving the surgical neck. Management of this group of fractures is often challenging and the outcome is frequently unsatisfactory. In particular it is not clear whether surgery gives better outcomes than non-surgical management. Currently there is much variation in the use of surgery and a lack of good quality evidence to inform this decision. Methods/Design We aim to undertake a pragmatic UK-based multi-centre randomised controlled trial evaluating the effectiveness and cost-effectiveness of surgical versus standard non-surgical treatment for adults with an acute closed displaced fracture of the proximal humerus with involvement of the surgical neck. The choice of surgical intervention is left to the surgeon, who must use techniques that they are fully experienced with. This will avoid 'learning curve' problems. We will promote good standards of non-surgical care, similarly insisting on care-provider competence, and emphasize the need for comparable provision of rehabilitation for both groups of patients. We aim to recruit 250 patients from a minimum of 18 NHS trauma centres throughout the UK. These patients will be followed-up for 2 years. The primary outcome is the Oxford Shoulder Score, which will be collected via questionnaires completed by the trial participants at 6, 12 and 24 months. This is a 12-item condition-specific questionnaire providing a total score based on the person's subjective assessment of pain and activities of daily living impairment. We will also collect data for other outcomes, including general health measures and complications, and for an economic evaluation. Additionally, we plan a systematic collection of reasons for non-inclusion of eligible patients who were not recruited into the trial, and their baseline

  9. Surgical interventions to treat humerus shaft fractures: A network meta-analysis of randomized controlled trials.

    Directory of Open Access Journals (Sweden)

    Jia-Guo Zhao

    Full Text Available There are three main surgical techniques to treat humeral shaft fractures: open reduction and plate fixation (ORPF, intramedullary nail (IMN fixation, and minimally invasive percutaneous osteosynthesis (MIPO. We performed a network meta-analysis to compare three surgical procedures, including ORPF, IMN fixation, and MIPO, to provide the optimum treatment for humerus shaft fractures.MEDLINE, EMBASE, Cochrane Bone, Joint and Muscle Trauma Group Specialised Register, and Cochrane library were researched for reports published up to May 2016. We only included randomized controlled trials (RCTs comparing two or more of the three surgical procedures, including the ORPF, IMN, and MIPO techniques, for humeral shaft fractures in adults. The methodological quality was evaluated based on the Cochrane risk of bias tool. We used WinBUGS1.4 to conduct this Bayesian network meta-analysis. We used the odd ratios (ORs with 95% confidence intervals (CIs to calculate the dichotomous outcomes and analyzed the percentages of the surface under the cumulative ranking curve.Seventeen eligible publications reporting 16 RCTs were included in this study. Eight hundred and thirty-two participants were randomized to receive one of three surgical procedures. The results showed that shoulder impingement occurred more commonly in the IMN group than with either ORPF (OR, 0.13; 95% CI, 0.03-0.37 or MIPO fixation (OR, 0.08; 95% CI, 0.00-0.69. Iatrogenic radial nerve injury occurred more commonly in the ORPF group than in the MIPO group (OR, 11.09; 95% CI, 1.80-124.20. There were no significant differences among the three procedures in nonunion, delayed union, and infection.Compared with IMN and ORPF, MIPO technique is the preferred treatment method for humeral shaft fractures.

  10. Randomized, double-blind, placebo-controlled trial using lidocaine patch 5% in traumatic rib fractures.

    Science.gov (United States)

    Ingalls, Nichole K; Horton, Zachary A; Bettendorf, Matthew; Frye, Ira; Rodriguez, Carlos

    2010-02-01

    The lidocaine patch 5% was developed to treat postherpetic neuralgia. Anecdotal experience at our institution suggests the lidocaine patch 5% decreases narcotic usage in patients with traumatic rib fractures. This trial was developed to define the patch's efficacy. Patients with rib fractures admitted to the trauma service at our Level I trauma center were enrolled and randomized in a 1 to 1 double-blind manner to receive a lidocaine patch 5% or placebo patch. Fifty-eight patients who met the inclusion criteria were enrolled from January 2007 to August 2008. Demographic and clinical information were recorded. The primary outcomes variable was total narcotic use, analyzed using the 1-tailed Mann-Whitney test. The secondary outcomes variables included non-narcotic pain medication, average pain score, pulmonary complications, and length of stay. Significance was defined based on a 1-sided test for the primary outcome and 2-sided tests for other comparisons, at p rib fractures, gender, trauma mechanism, preinjury lung disease, smoking history, percent of current smokers, and need for placement of chest tube between the lidocaine patch 5% and placebo groups. There was no difference between the lidocaine patch 5% and placebo groups, respectively, with regard to total IV narcotic usage: median, 0.23 units versus 0.26 units; total oral narcotics: median, 4 units versus 7 units; pain score: 5.6 +/- 0.4 versus 6.0 +/- 0.3 (mean +/- SEM); length of stay: 7.8 +/- 1.1 versus 6.2 +/- 0.7; or percentage of patients with pulmonary complications: 72.7% versus 72.0%. The lidocaine patch 5% does not significantly improve pain control in polytrauma patients with traumatic rib fractures.

  11. Fracture Mechanics

    CERN Document Server

    Zehnder, Alan T

    2012-01-01

    Fracture mechanics is a vast and growing field. This book develops the basic elements needed for both fracture research and engineering practice. The emphasis is on continuum mechanics models for energy flows and crack-tip stress- and deformation fields in elastic and elastic-plastic materials. In addition to a brief discussion of computational fracture methods, the text includes practical sections on fracture criteria, fracture toughness testing, and methods for measuring stress intensity factors and energy release rates. Class-tested at Cornell, this book is designed for students, researchers and practitioners interested in understanding and contributing to a diverse and vital field of knowledge. Alan Zehnder joined the faculty at Cornell University in 1988. Since then he has served in a number of leadership roles including Chair of the Department of Theoretical and Applied Mechanics, and Director of the Sibley School of Mechanical and Aerospace Engineering.  He teaches applied mechanics and his research t...

  12. Controller design for Robotic hand through Electroencephalogram

    Directory of Open Access Journals (Sweden)

    Pandelidis P.

    2016-01-01

    Full Text Available - This paper deals with the designing, the construction and the control of a robotic hand via an electroencephalogram sensor. First a robotic device that is able to mimic a real human hand is constructed. A PID controller is designed in order to improve the performance of the robotic arm for grabbing objects. Furthermore, a novel design approach is presented for controlling the motion of the robotic arm using signals produced from an innovative electroencephalogram sensor that detects the concentration of the brain

  13. Conceptual design of multiple parallel switching controller

    International Nuclear Information System (INIS)

    Ugolini, D.; Yoshikawa, S.; Ozawa, K.

    1996-01-01

    This paper discusses the conceptual design and the development of a preliminary model of a multiple parallel switching (MPS) controller. The introduction of several advanced controllers has widened and improved the control capability of nonlinear dynamical systems. However, it is not possible to uniquely define a controller that always outperforms the others, and, in many situations, the controller providing the best control action depends on the operating conditions and on the intrinsic properties and behavior of the controlled dynamical system. The desire to combine the control action of several controllers with the purpose to continuously attain the best control action has motivated the development of the MPS controller. The MPS controller consists of a number of single controllers acting in parallel and of an artificial intelligence (AI) based selecting mechanism. The AI selecting mechanism analyzes the output of each controller and implements the one providing the best control performance. An inherent property of the MPS controller is the possibility to discard unreliable controllers while still being able to perform the control action. To demonstrate the feasibility and the capability of the MPS controller the simulation of the on-line operation control of a fast breeder reactor (FBR) evaporator is presented. (author)

  14. Fracture toughness of zirconia ceramic crowns made by feather-edge tooth preparation design

    Directory of Open Access Journals (Sweden)

    Mirković Nemanja

    2012-01-01

    Full Text Available Background/Aim. Fracture toughness determines functional crown strenght and prevents damages on ceramics during mastication. There is a lack of relevant literature data about fracture toughness of crowns made by feather-edge preparation. Mechanical testing of ceramic samples is supposed to show if feather-edge tooth preparation is a successful method for making ceramic crowns without any risk of reduction of their mechanical properties. This research was done to establish effects of feather-edge tooth preparation on fracture toughness of single zirconia ceramic crowns. Methods. The research was performed as an experimental study. Sixty (60 ceramic crowns were made on non-carious extracted human premolars. Thirty (30 crowns were made on the basis of feather-edge preparation (experimental group I. The group II included 30 crowns made on 1 mm rounded shoulder. Crowns fabrication was executed on a copy mill production system “Zirkonzahn” (Zirkonzahn GMBH, Gais, Germany. The spherical compression test was used to determine fracture toughness, using 6 mm diameter ceramic ball. Fracture load for damaging ceramic crown was recorded on a universal testing machine - Zwick, type 1464, with the speed of 0.05 mm/min. Results. The results of this research introduced significant differences between fracture toughness of ceramic samples in every examined group. However, fracture toughness of crowns from both group was above 2 000 N, what was double beyond a recommended value. The mean value of fracture toughness in the feather-edge group was 2 090 N, and in shoulder group it was 2 214 N. Conclusion. This research showed a high fracture toughness of zirconia crowns made on feather-edge preparation. The examined crowns showed a fracture resistance at a sufficient distance in relation to the minimum values of functional loads. Further research of functional loads of these crown is necessary, as well as research of marginal adaptation of cemented crowns and

  15. Design Of Feedforward Controllers For Multivariable Plants

    Science.gov (United States)

    Seraji, Homayoun

    1989-01-01

    Controllers based on simple low-order transfer functions. Mathematical criteria derived for design of feedforward controllers for class of multiple-input/multiple-output linear plants. Represented by simple low-order transfer functions, obtained without reconstruction of states of commands and disturbances. Enables plant to track command while remaining unresponsive to disturbance in steady state. Feedback controller added independently to stabilize plant or to make control system less susceptible to variations in parameters of plant.

  16. Promoting mobility after hip fracture (ProMo: study protocol and selected baseline results of a year-long randomized controlled trial among community-dwelling older people

    Directory of Open Access Journals (Sweden)

    Sipilä Sarianna

    2011-12-01

    Full Text Available Abstract Background To cope at their homes, community-dwelling older people surviving a hip fracture need a sufficient amount of functional ability and mobility. There is a lack of evidence on the best practices supporting recovery after hip fracture. The purpose of this article is to describe the design, intervention and demographic baseline results of a study investigating the effects of a rehabilitation program aiming to restore mobility and functional capacity among community-dwelling participants after hip fracture. Methods/Design Population-based sample of over 60-year-old community-dwelling men and women operated for hip fracture (n = 81, mean age 79 years, 78% were women participated in this study and were randomly allocated into control (Standard Care and ProMo intervention groups on average 10 weeks post fracture and 6 weeks after discharged to home. Standard Care included written home exercise program with 5-7 exercises for lower limbs. Of all participants, 12 got a referral to physiotherapy. After discharged to home, only 50% adhered to Standard Care. None of the participants were followed-up for Standard Care or mobility recovery. ProMo-intervention included Standard Care and a year-long program including evaluation/modification of environmental hazards, guidance for safe walking, pain management, progressive home exercise program and physical activity counseling. Measurements included a comprehensive battery of laboratory tests and self-report on mobility limitation, disability, physical functional capacity and health as well as assessments for the key prerequisites for mobility, disability and functional capacity. All assessments were performed blinded at the research laboratory. No significant differences were observed between intervention and control groups in any of the demographic variables. Discussion Ten weeks post hip fracture only half of the participants were compliant to Standard Care. No follow-up for Standard Care or

  17. Design Robust Controller for Rotary Kiln

    Directory of Open Access Journals (Sweden)

    Omar D. Hernández-Arboleda

    2013-11-01

    Full Text Available This paper presents the design of a robust controller for a rotary kiln. The designed controller is a combination of a fractional PID and linear quadratic regulator (LQR, these are not used to control the kiln until now, in addition robustness criteria are evaluated (gain margin, phase margin, strength gain, rejecting high frequency noise and sensitivity applied to the entire model (controller-plant, obtaining good results with a frequency range of 0.020 to 90 rad/s, which contributes to the robustness of the system.

  18. Wind energy systems control engineering design

    CERN Document Server

    Garcia-Sanz, Mario

    2012-01-01

    IntroductionBroad Context and MotivationConcurrent Engineering: A Road Map for EnergyQuantitative Robust ControlNovel CAD Toolbox for QFT Controller DesignOutline Part I: Advanced Robust Control Techniques: QFT and Nonlinear SwitchingIntroduction to QFTQuantitative Feedback TheoryWhy Feedback? QFT OverviewInsight into the QFT TechniqueBenefits of QFTMISO Analog QFT Control SystemIntroductionQFT Method (Single-Loop MISO System)Design Procedure OutlineMinimum-Phase System Performance SpecificationsJ LTI Plant ModelsPlant Templates of P?(s), P( j_i )Nominal PlantU-Contour (Stability Bound)Trackin

  19. Design and preparation of controlled floating gastroretentive ...

    African Journals Online (AJOL)

    gastroretentive delivery systems for enhanced fexofenadine ... Abstract. Purpose: To design and prepare effervescent floating gastroretentive tablets for controlled fexofenadine ..... Complex of Carbopol with Polyvinylpyrrolidone as a. Matrix for ...

  20. Design of a nuclear reactor cooperative controller

    International Nuclear Information System (INIS)

    Alang-Rashid, N.K.; Heger, A.S.

    1991-01-01

    This paper describes the development of a fuzzy logic controller software package and explores the feasibility of its use in nuclear reactor operation. The controller complements reactor operator actions, and the operators can override the controller decisions. Techniques of providing learning capability to the controller are also being investigated to improve the reasoning and control skill of the controller. The fuzzy logic controller is implemented in C language and its overall structure is shown. The heart of the systems consists of a fuzzifier, a rule interpreter, and a defuzzifier. The controller is designed as a stand-alone package that can be interfaced to a simulated model of a nuclear reactor. Since no model is an accurate representation of the actual process being modeled, some tuning must be performed to use the controller in an actual reactor. This is accomplished using the learning feature of the controller

  1. Control system design for concrete irrigation channels

    OpenAIRE

    Strecker, Timm; Aamo, Ole Morten; Cantoni, Michael

    2017-01-01

    Concrete channels find use at the periphery of irrigation networks, for expansion and to replace small earthen channels given the relative ease of maintenance and elimination of seepage losses. In design, it is important to account for control system performance when dimensioning the channel infrastructure. In this paper, the design of a distributed controller is investigated in terms managing water-levels, and thereby the depth profile (i.e., amount of concrete) needed to support peak flow l...

  2. Decentralized robust control design using LMI

    Directory of Open Access Journals (Sweden)

    Dušan Krokavec

    2008-03-01

    Full Text Available The paper deals with application of decentralized controllers for large-scale systems with subsystems interaction and system matrices uncertainties. The desired stability of the whole system is guaranteed while at the same time the tolerable bounds in the uncertainties due to structural changes are maximized. The design approach is based on the linear matrix inequalities (LMI techniques adaptation for stabilizing controller design.

  3. Integrated Design Tools for Embedded Control Systems

    OpenAIRE

    Jovanovic, D.S.; Hilderink, G.H.; Broenink, Johannes F.; Karelse, F.

    2001-01-01

    Currently, computer-based control systems are still being implemented using the same techniques as 10 years ago. The purpose of this project is the development of a design framework, consisting of tools and libraries, which allows the designer to build high reliable heterogeneous real-time embedded systems in a very short time at a fraction of the present day costs. The ultimate focus of current research is on transformation control laws to efficient concurrent algorithms, with concerns about...

  4. Model predictive controller design of hydrocracker reactors

    OpenAIRE

    GÖKÇE, Dila

    2011-01-01

    This study summarizes the design of a Model Predictive Controller (MPC) in Tüpraş, İzmit Refinery Hydrocracker Unit Reactors. Hydrocracking process, in which heavy vacuum gasoil is converted into lighter and valuable products at high temperature and pressure is described briefly. Controller design description, identification and modeling studies are examined and the model variables are presented. WABT (Weighted Average Bed Temperature) equalization and conversion increase are simulate...

  5. New trends in designing NPP control boards

    International Nuclear Information System (INIS)

    Kondrat'ev, V.V.

    1981-01-01

    A short analytical summary of the latest developments and future trends in designing NPP control boards is given. The designs of the Westinghause and the Hynkley-Point NPP control boards are described in detail. The essence of the advanced control board concept consists , firstly, in expanded use of computer-controlled displays for the sake of reducing the content of unimportant information presented to an operator, and, secondary, in better account of human possibilities to convert the NPP operation information into a more suitable form. An enlarged use of the direct digital reactor control utilizing microprocessors is expected. Besides, the employment of full-scale control board mock-ups and information desks as well as testing newly-developed control boards at computer reactor simulators are concluded to be used at all-growing rate [ru

  6. Biological Systems Thinking for Control Engineering Design

    Directory of Open Access Journals (Sweden)

    D. J. Murray-Smith

    2004-01-01

    Full Text Available Artificial neural networks and genetic algorithms are often quoted in discussions about the contribution of biological systems thinking to engineering design. This paper reviews work on the neuromuscular system, a field in which biological systems thinking could make specific contributions to the development and design of automatic control systems for mechatronics and robotics applications. The paper suggests some specific areas in which a better understanding of this biological control system could be expected to contribute to control engineering design methods in the future. Particular emphasis is given to the nonlinear nature of elements within the neuromuscular system and to processes of neural signal processing, sensing and system adaptivity. Aspects of the biological system that are of particular significance for engineering control systems include sensor fusion, sensor redundancy and parallelism, together with advanced forms of signal processing for adaptive and learning control

  7. Optimal control design for a solar greenhouse

    NARCIS (Netherlands)

    Ooteghem, van R.J.C.

    2007-01-01

    The research of this thesis was part of a larger project aiming at the design of a greenhouse and an associated climate control that achieves optimal crop production with sustainable instead of fossil energy. This so called solar greenhouse design extends a conventional greenhouse with an improved

  8. Integrated Design Tools for Embedded Control Systems

    NARCIS (Netherlands)

    Jovanovic, D.S.; Hilderink, G.H.; Broenink, Johannes F.; Karelse, F.

    2001-01-01

    Currently, computer-based control systems are still being implemented using the same techniques as 10 years ago. The purpose of this project is the development of a design framework, consisting of tools and libraries, which allows the designer to build high reliable heterogeneous real-time embedded

  9. A Study on the Fracture Control of Rock Bolts in High Ground Pressure Roadways of Deep Mines

    Directory of Open Access Journals (Sweden)

    Wen Jinglin

    2015-01-01

    Full Text Available According to the frequent fractures of rock bolts in high ground pressure roadways of deep mines, this paper analyzes the mechanism of fractures and concludes that high ground pressure and material de-fects are main reasons for the fracture of rock bolts. The basic idea of fracture control of rock bolts in high ground pressure roadways of deep mines is to increase the yield load and the limit load of rock bolt materials and reduce the actual load of rock bolts. There are four ways of controlling rock bolt fracture: increasing the rock bolt diameter, strengthening bolt materials, weakening support rigidity and the implementation of double supporting. With the roadway support of the 2302 working face of a coal mine as the project background, this paper carries out a study on the effect of two schemes, increasing the rock bolt diameter and the double supporting technique through methods of theoretical analysis, numerical simulation and so on. It determines the most reasonable diam-eter of rock bolts and the best delay distance of secondary support. Practices indicate that rock bolt fracture can be effectively controlled through the double supporting technique, which strengthens the roof and two sides through the first supporting technique and strengthens side angles through the secondary supporting technique.

  10. Automatic control design procedures for restructurable aircraft control

    Science.gov (United States)

    Looze, D. P.; Krolewski, S.; Weiss, J.; Barrett, N.; Eterno, J.

    1985-01-01

    A simple, reliable automatic redesign procedure for restructurable control is discussed. This procedure is based on Linear Quadratic (LQ) design methodologies. It employs a robust control system design for the unfailed aircraft to minimize the effects of failed surfaces and to extend the time available for restructuring the Flight Control System. The procedure uses the LQ design parameters for the unfailed system as a basis for choosing the design parameters of the failed system. This philosophy alloys the engineering trade-offs that were present in the nominal design to the inherited by the restructurable design. In particular, it alloys bandwidth limitations and performance trade-offs to be incorporated in the redesigned system. The procedure also has several other desirable features. It effectively redistributes authority among the available control effectors to maximize the system performance subject to actuator limitations and constraints. It provides a graceful performance degradation as the amount of control authority lessens. When given the parameters of the unfailed aircraft, the automatic redesign procedure reproduces the nominal control system design.

  11. Analysis and design of hybrid control systems

    Energy Technology Data Exchange (ETDEWEB)

    Malmborg, J.

    1998-05-01

    Different aspects of hybrid control systems are treated: analysis, simulation, design and implementation. A systematic methodology using extended Lyapunov theory for design of hybrid systems is developed. The methodology is based on conventional control designs in separate regions together with a switching strategy. Dynamics are not well defined if the control design methods lead to fast mode switching. The dynamics depend on the salient features of the implementation of the mode switches. A theorem for the stability of second order switching together with the resulting dynamics is derived. The dynamics on an intersection of two sliding sets are defined for two relays working on different time scales. The current simulation packages have problems modeling and simulating hybrid systems. It is shown how fast mode switches can be found before or during simulation. The necessary analysis work is a very small overhead for a modern simulation tool. To get some experience from practical problems with hybrid control the switching strategy is implemented in two different software environments. In one of them a time-optimal controller is added to an existing PID controller on a commercial control system. Successful experiments with this hybrid controller shows the practical use of the method 78 refs, 51 figs, 2 tabs

  12. Pulsed Electromagnetic Fields in the treatment of fresh scaphoid fractures. A multicenter, prospective, double blind, placebo controlled, randomized trial.

    Science.gov (United States)

    Hannemann, Pascal; Göttgens, Kevin W A; van Wely, Bob J; Kolkman, Karel A; Werre, Andries J; Poeze, Martijn; Brink, Peter R G

    2011-05-06

    The scaphoid bone is the most commonly fractured of the carpal bones. In the Netherlands 90% of all carpal fractures is a fracture of the scaphoid bone. The scaphoid has an essential role in functionality of the wrist, acting as a pivot. Complications in healing can result in poor functional outcome. The scaphoid fracture is a troublesome fracture and failure of treatment can result in avascular necrosis (up to 40%), non-union (5-21%) and early osteo-arthritis (up to 32%) which may seriously impair wrist function. Impaired consolidation of scaphoid fractures results in longer immobilization and more days lost at work with significant psychosocial and financial consequences.Initially Pulsed Electromagnetic Fields was used in the treatment of tibial pseudoarthrosis and non-union. More recently there is evidence that physical forces can also be used in the treatment of fresh fractures, showing accelerated healing by 30% and 71% reduction in nonunion within 12 weeks after initiation of therapy. Until now no double blind randomized, placebo controlled trial has been conducted to investigate the effect of this treatment on the healing of fresh fractures of the scaphoid. This is a multi center, prospective, double blind, placebo controlled, randomized trial. Study population consists of all patients with unilateral acute scaphoid fracture. Pregnant women, patients having a life supporting implanted electronic device, patients with additional fractures of wrist, carpal or metacarpal bones and pre-existing impairment in wrist function are excluded. The scaphoid fracture is diagnosed by a combination of physical and radiographic examination (CT-scanning).Proven scaphoid fractures are treated with cast immobilization and a small Pulsed Electromagnetic Fields bone growth stimulating device placed on the cast. Half of the devices will be disabled at random in the factory.Study parameters are clinical consolidation, radiological consolidation evaluated by CT-scanning, functional

  13. Non-Steroid Anti-Inflammatory Drugs Are Better than Acetaminophen on Fever Control at Acute Stage of Fracture.

    Directory of Open Access Journals (Sweden)

    Kuang-Ting Yeh

    Full Text Available In addition to adequate surgical fixation and an aggressive rehabilitation program, pain relief is one of the most critical factors in the acute stage of fracture treatment. The most common analgesics are nonsteroid anti-inflammatory drugs and Acetaminophen, both of which relieve pain and reduce body temperature. In clinical experiences, they exhibit effective pain control; however, their influence on body temperature remains controversial. This study is aimed at determining the effects of analgesics at the acute stage of traumatic fracture by performing a clinical retrospective study of patients with fractures and a fracture animal model. The retrospective study revealed that, in the acetaminophen group, the mean value of postmedication body temperature (BT was significantly higher than that of the premedication BT. The change in BT was highly related with the medication rather than other risk factors. Forty eight 12-week-old male Wistar rats were divided into 6 groups: a control group, fracture group, fracture-Acetaminophen group, Acetaminophen group, fracture-Arcoxia group, and Arcoxia group. Fracture rats were prepared by breaking their unilateral tibia and fibula. Their inflammation conditions were evaluated by measuring their serum cytokine level and their physiological status was evaluated by estimating their central temperature, heart rate, and mean blood pressure. The hepatic adverse effects were assessed by measuring the serum levels of aspartate aminotransferase (sGOT and alanine aminotransferase (sGPT. The central temperature in the fracture-Acetaminophen group exceeded that in the groups fed normal saline water or Arcoxia. Accumulated hepatic injury was presented as steadily ascending curves of sGOT and sGPT. Inflammation-related cytokine levels were not higher in the Acetaminophen fracture group and were significantly lower in the fracture-Arcoxia group. Fever appeared to be aggravated by acetaminophen and more related to the

  14. Controlled air incinerator conceptual design study

    International Nuclear Information System (INIS)

    1982-01-01

    This report presents a conceptual design study for a controlled air incinerator facility for incineration of low level combustible waste at Three Mile Island Unit 2 (TMI-2). The facility design is based on the use of a Helix Process Systems controlled air incinerator. Cost estimates and associated engineering, procurement, and construction schedules are also provided. The cost estimates and schedules are presented for two incinerator facility designs, one with provisions for waste ash solidification, the other with provisions for packaging the waste ash for transport to an undefined location

  15. Studies on groundwater transport in fractured crystalline rock under controlled conditions using nonradioactive tracers

    International Nuclear Information System (INIS)

    Gustafsson, E.; Klockars, C.-E.

    1981-04-01

    The purpose of the investigation has been study the following parameters along existing fractures between two boreholes: hydraulic properties of rock mass and fractures; adsorptive properties of some selected tracers during transport along fractures; dispersivity and dilution of tracers during transport in fractures; kinematic porosity of fractured bedrock. The procedure has been to determine the hydraulic properties of a rock mass by means of conventional hydraulic testing methods in 100 m deep boreholes, and to study transport mechanisms and properties of selected tracers in a selected fracture zone between two boreholes. (Auth.)

  16. Design, modeling and control of nanopositioning systems

    CERN Document Server

    Fleming, Andrew J

    2014-01-01

    Covering the complete design cycle of nanopositioning systems, this is the first comprehensive text on the topic. The book first introduces concepts associated with nanopositioning stages and outlines their application in such tasks as scanning probe microscopy, nanofabrication, data storage, cell surgery and precision optics. Piezoelectric transducers, employed ubiquitously in nanopositioning applications are then discussed in detail including practical considerations and constraints on transducer response. The reader is then given an overview of the types of nanopositioner before the text turns to the in-depth coverage of mechanical design including flexures, materials, manufacturing techniques, and electronics. This process is illustrated by the example of a high-speed serial-kinematic nanopositioner. Position sensors are then catalogued and described and the text then focuses on control. Several forms of control are treated: shunt control, feedback control, force feedback control and feedforward control (...

  17. Computer-aided control system design

    International Nuclear Information System (INIS)

    Lebenhaft, J.R.

    1986-01-01

    Control systems are typically implemented using conventional PID controllers, which are then tuned manually during plant commissioning to compensate for interactions between feedback loops. As plants increase in size and complexity, such controllers can fail to provide adequate process regulations. Multivariable methods can be utilized to overcome these limitations. At the Chalk River Nuclear Laboratories, modern control systems are designed and analyzed with the aid of MVPACK, a system of computer programs that appears to the user like a high-level calculator. The software package solves complicated control problems, and provides useful insight into the dynamic response and stability of multivariable systems

  18. Design of Vickers Hardness Loading Controller

    Directory of Open Access Journals (Sweden)

    Sihai Zhao

    2014-09-01

    Full Text Available Traditionally Vickers testing needs manual works, as a result, it will induce low precision and automatization. So this paper design a new type of loading controlling system, it is based on single chip computer 89S52, used PZT as the force generator in micro Vickers hardness testing. It primarily includes the designing of hardware, software of collecting data and PZT signals by AD667. This article has given the sketch of electrical circuit and controlling software, it also offers the experiment data. The experiments have showed that using this system can exactly control the loading results, and the average tolerance is less than 0.43 %.

  19. Robust Structured Control Design via LMI Optimization

    DEFF Research Database (Denmark)

    Adegas, Fabiano Daher; Stoustrup, Jakob

    2011-01-01

    This paper presents a new procedure for discrete-time robust structured control design. Parameter-dependent nonconvex conditions for stabilizable and induced L2-norm performance controllers are solved by an iterative linear matrix inequalities (LMI) optimization. A wide class of controller...... structures including decentralized of any order, fixed-order dynamic output feedback, static output feedback can be designed robust to polytopic uncertainties. Stability is proven by a parameter-dependent Lyapunov function. Numerical examples on robust stability margins shows that the proposed procedure can...

  20. Matlab as a robust control design tool

    Science.gov (United States)

    Gregory, Irene M.

    1994-01-01

    This presentation introduces Matlab as a tool used in flight control research. The example used to illustrate some of the capabilities of this software is a robust controller designed for a single stage to orbit air breathing vehicles's ascent to orbit. The global requirements of the controller are to stabilize the vehicle and follow a trajectory in the presence of atmospheric disturbances and strong dynamic coupling between airframe and propulsion.

  1. Probabilistic design of aluminum sheet drawing for reduced risk of wrinkling and fracture

    International Nuclear Information System (INIS)

    Zhang Wenfeng; Shivpuri, Rajiv

    2009-01-01

    Often, sheet drawing processes are designed to provide the geometry of the final part, and then the process parameters such as blank dimensions, blank holder forces (BHFs), press strokes and interface friction are designed and controlled to provide the greatest drawability (largest depth of draw without violating the wrinkling and thinning constraints). The exclusion of inherent process variations in this design can often lead to process designs that are unreliable and uncontrollable. In this paper, a general multi-criteria design approach is presented to quantify the uncertainties and to incorporate them into the response surface method (RSM) based model so as to conduct probabilistic optimization. A surrogate RSM model of the process mechanics is generated using FEM-based high-fidelity models and design of experiments (DOEs), and a simple linear weighted approach is used to formulate the objective function or the quality index (QI). To demonstrate this approach, deep drawing of an aluminum Hishida part is analyzed. With the predetermined blank shape, tooling design and fixed drawing depth, a probabilistic design (PD) is successfully carried out to find the optimal combination of BHF and friction coefficient under variation of material properties. The results show that with the probabilistic approach, the QI improved by 42% over the traditional deterministic design (DD). It also shows that by further reducing the variation of friction coefficient to 2%, the QI will improve further to 98.97%

  2. Controller Architecture Design for MMC-HVDC

    Directory of Open Access Journals (Sweden)

    ZHANG, B.

    2014-05-01

    Full Text Available Compared with high voltage direct current (HVDC, the primary and secondary systems of modular multilevel converter based HVDC (MMC-HVDC are complicated. And the characteristics of the control system determine the properties of the MMC-HVDC system to a certain extent. This paper investigates the design of control architecture. First, the structure and parameters of the 21-level MMC-HVDC are designed. Second, the framework of the control system is studied in details and a complete control system is established. The communication mode and content are built between each layer, and the control system program is developed and debugged. Then The steady state test platform of the sub-module and the relevant control system are designed. Finally, the steady-state tests and the system test of the physical MMC-HVDC simulation system are conducted, which prove that the SMC can control the sub-module (SM efficiently, and the control system could realize efficient start and stop of the physical system. Meanwhile, the capacitor voltage balance between the sub-modules and the basic fault protection and control of the DC voltage and power are verified to be effective.

  3. A randomized, controlled comparison of home versus institutional rehabilitation of patients with hip fracture.

    Science.gov (United States)

    Kuisma, Raija

    2002-08-01

    To compare ambulation outcomes between home and institutional rehabilitation of patients with hip fracture. Randomized controlled clinical equivalence trial. The Queen Elizabeth Hospital in Hong Kong. Eighty-one patients with hip fracture. Study group patients (40) were discharged directly home from the acute hospital and visited by a physiotherapist an average of 4.6 times. The control group subjects (41) were discharged to a rehabilitation centre for further treatment lasting on average 36.2 days (SD 14.6) and they received physiotherapy daily. Ambulation ability measured on a categorical scale. The mean age of the subjects was 75 years (SD 8.3 years). Females comprised 60% of all the subjects and majority were retired or home makers. Both groups of patients improved in their ambulation ability during their rehabilitation period but neither group achieved their pre-ambulatory status by the time of completion of the study. The study group achieved significantly higher ambulation scores (p institution-based rehabilitation.

  4. Effect of mix design on the size-independent fracture energy of normal- and high-strength self-compacting concrete

    International Nuclear Information System (INIS)

    Cifuentes, H.; Ríos, J.D.; Gómez, E.J.

    2018-01-01

    Self-compacting concrete has a characteristic microstructure inherent to its specific composition. The higher content of fine particles in self-compacting concrete relative to the equivalent vibrated concrete produces a different fracture behavior that affects the main fracture parameters. In this work, a comprehensive experimental investigation of the fracture behavior of self-compacting concrete has been carried out. Twelve different self-compacting concrete mixes with compressive strength ranging from 39 to 124 MPa (wider range than in other studies) have been subjected to three-point bending tests in order to determine the specific fracture energy. The influence of the mix design and its composition (coarse aggregate fraction, the water to binder ratio and the paste to solids ratio) on its fracture behavior has been analyzed. Moreover, further evidence of the objectivity of the size-independent fracture energy results, obtained by the two most commonly used methods, has been p [es

  5. Bangbang controller design and implementation for EAST vertical instability control

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yuehang, E-mail: wagn8901@mail.ustc.edu.cn [University of Science and Technology of China, Hefei (China); Xiao, Bingjia, E-mail: bjxiao@ipp.ac.cn [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei (China); University of Science and Technology of China, Hefei (China); Liu, Lei, E-mail: liulei@ipp.ac.cn [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei (China); Yuan, Qiping, E-mail: qpyuan@ipp.ac.cn [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei (China)

    2016-11-15

    Highlights: • The linearized plasma vertical response model is designed and analysed. • The Bangbang controller for EAST vertical displacement is designed. • The Bangbang controller is optimized for time delay of control system. • We investigate efficacy of Bangbang controller with simulations. • Performance of the controller is roughly given by experiments. - Abstract: In the EAST 2014 campaign, a new internal coil (IC) power supply was used in order to enhance the control over the plasma’s vertical instabilities. The IC power supply now allows for current and voltage working modes with much higher peak voltages and currents and faster response time. In comparison the previous power supply only allowed for the current mode. A Bangbang and PID composite controller has been designed for the voltage mode based on optimal control theory and the RZIP rigid plasma response model. This paper will demonstrate that faster and enhanced controllability are realized with the combination of Bangbang and PID controller. For the large z position drift, the Bangbang controller will export the maximum voltage to achieve much faster power supply response and slow the vertical displacement events (VDEs). The PID controller is used for the small z drifts which will finally stabilize the VDEs with minimum z position oscillation. Furthermore, to evaluate the time latency of this control system and power supply, the stability and performance of the closed loop were simulated and analysed. This controller was finally implementation and test on EAST using the Quasi-snowflake shape which achieved growth rates of 500 s{sup −1}. This paper shows that the new power supply using the bangbang + PID controller can significantly enhance the control over vertical instabilities.

  6. A customized fixation plate with novel structure designed by topological optimization for mandibular angle fracture based on finite element analysis.

    Science.gov (United States)

    Liu, Yun-Feng; Fan, Ying-Ying; Jiang, Xian-Feng; Baur, Dale A

    2017-11-15

    The purpose of this study was to design a customized fixation plate for mandibular angle fracture using topological optimization based on the biomechanical properties of the two conventional fixation systems, and compare the results of stress, strain and displacement distributions calculated by finite element analysis (FEA). A three-dimensional (3D) virtual mandible was reconstructed from CT images with a mimic angle fracture and a 1 mm gap between two bone segments, and then a FEA model, including volume mesh with inhomogeneous bone material properties, three loading conditions and constraints (muscles and condyles), was created to design a customized plate using topological optimization method, then the shape of the plate was referenced from the stress concentrated area on an initial part created from thickened bone surface for optimal calculation, and then the plate was formulated as "V" pattern according to dimensions of standard mini-plate finally. To compare the biomechanical behavior of the "V" plate and other conventional mini-plates for angle fracture fixation, two conventional fixation systems were used: type A, one standard mini-plate, and type B, two standard mini-plates, and the stress, strain and displacement distributions within the three fixation systems were compared and discussed. The stress, strain and displacement distributions to the angle fractured mandible with three different fixation modalities were collected, respectively, and the maximum stress for each model emerged at the mandibular ramus or screw holes. Under the same loading conditions, the maximum stress on the customized fixation system decreased 74.3, 75.6 and 70.6% compared to type A, and 34.9, 34.1, and 39.6% compared to type B. All maximum von Mises stresses of mandible were well below the allowable stress of human bone, as well as maximum principal strain. And the displacement diagram of bony segments indicated the effect of treatment with different fixation systems. The

  7. Hip fracture risk and cadmium in erythrocytes: a nested case-control study with prospectively collected samples.

    Science.gov (United States)

    Sommar, Johan Nilsson; Pettersson-Kymmer, Ulrika; Lundh, Thomas; Svensson, Olle; Hallmans, Göran; Bergdahl, Ingvar A

    2014-02-01

    Several studies have investigated the relation between bone mass density and cadmium exposure, but only few studies have been performed on fractures and biomarkers of cadmium. This study analyzed the association between hip fracture risk and cadmium in erythrocytes (Ery-Cd). Prospective samples from the Northern Sweden Health and Disease Study's biobank were used for 109 individuals who later in life had sustained a low-trauma hip fracture, matched with two controls of the same age and gender. The mean concentration of Ery-Cd (±SD) in case samples was 1.3 ± 1.4 versus 0.9 ± 1.0 μg/L in controls. The odds ratio (OR) was 1.63 [95% confidence interval (CI) 1.10-2.42] for suffering a hip fracture for each microgram per liter increase in Ery-Cd. However, when taking smoking into consideration (never, former, or current), neither Ery-Cd nor smoking showed a statistically significant increase in fracture risk. Using multiple conditional logistic regression with BMI, height, and smoking, the estimated OR for a 1-μg/L increase in Ery-Cd was 1.52 (95% CI 0.77-2.97). Subgroup analysis showed an increased fracture risk among women (OR = 1.94, 95% CI 1.18-3.20, for a 1 μg/L increase), which also remained in the multiple analysis (OR = 3.33, 95% CI 1.29-8.56). This study shows that fracture risk is associated with Ery-Cd. It is, however, not possible to draw firm conclusions on whether cadmium is the causal factor or whether other smoking-related factors cause this association. Subgroup analysis shows that cadmium is a risk factor for hip fracture among women.

  8. Towards practical control design using neural computation

    Science.gov (United States)

    Troudet, Terry; Garg, Sanjay; Mattern, Duane; Merrill, Walter

    1991-01-01

    The objective is to develop neural network based control design techniques which address the issue of performance/control effort tradeoff. Additionally, the control design needs to address the important issue if achieving adequate performance in the presence of actuator nonlinearities such as position and rate limits. These issues are discussed using the example of aircraft flight control. Given a set of pilot input commands, a feedforward net is trained to control the vehicle within the constraints imposed by the actuators. This is achieved by minimizing an objective function which is the sum of the tracking errors, control input rates and control input deflections. A tradeoff between tracking performance and control smoothness is obtained by varying, adaptively, the weights of the objective function. The neurocontroller performance is evaluated in the presence of actuator dynamics using a simulation of the vehicle. Appropriate selection of the different weights in the objective function resulted in the good tracking of the pilot commands and smooth neurocontrol. An extension of the neurocontroller design approach is proposed to enhance its practicality.

  9. The Hip Fracture Surgery in Elderly Patients (HIPELD study: protocol for a randomized, multicenter controlled trial evaluating the effect of xenon on postoperative delirium in older patients undergoing hip fracture surgery

    Directory of Open Access Journals (Sweden)

    Coburn Mark

    2012-09-01

    Full Text Available Abstract Background Strategies to protect the brain from postoperative delirium (POD after hip fracture are urgently needed. The development of delirium often is associated with the loss of independence, poor functional recovery, and increased morbidity, as well as increases in length of hospital stay, discharges to nursing facilities, and healthcare costs. We hypothesize that xenon may reduce the burden of POD, (i by avoiding the need to provide anesthesia with a drug that targets the γ-amino-butyric acid (GABAA receptor and (ii through beneficial anesthetic and organ-protective effects. Methods and design An international, multicenter, phase 2, prospective, randomized, blinded, parallel group and controlled trial to evaluate the incidence of POD, diagnosed with the Confusion Assessment Method (CAM, in older patients undergoing hip fracture surgery under general anesthesia with xenon or sevoflurane, for a period of 4 days post surgery (primary outcome is planned. Secondary objectives are to compare the incidence of POD between xenon and sevoflurane, to evaluate the incidence of POD from day 5 post surgery until discharge from hospital, to determine the time to first POD diagnosis, to evaluate the duration of POD, to evaluate the evolution of the physiological status of the patients in the postoperative period, to evaluate the recovery parameters, to collect preliminary data to evaluate the economical impact of POD in the postoperative period and to collect safety data. Patients are eligible if they are older aged (≥ 75 years and assigned to a planned hip fracture surgery within 48 h after the hip fracture. Furthermore, patients need to be willing and able to complete the requirements of this study including the signature of the written informed consent. A total of 256 randomized patients in the 10 participating centers will be recruited, that is, 128 randomized patients in each of the 2 study groups (receiving either xenon or sevoflurane

  10. Unfalsified Control; Application to automatic flight control system design

    Directory of Open Access Journals (Sweden)

    Adrian-Mihail STOICA

    2011-09-01

    Full Text Available Unfalsified Control Theory has been developed to provide a way for avoiding modeling uncertainties in controller design. It belongs to the class of control methods called Adaptive Supervisory Switching Control, which work by introducing in the control scheme a supervisory unit which chooses, from a set of candidate controllers the one most suited for the current plant. Unfalsified Control works by using a switching logic that dispenses with the need for a-priori knowledge of the dynamic model. At discrete moments of time, using the input/output data recorded up to that point, the supervisory calculates for each candidate controller a performance index, and compares it to a given threshold. Controllers surpassing that threshold are removed from the candidate controller set. This process is called falsification. If the controller in the loop is one such falsified controller it is replaced. In this paper we investigate the suitability of this method for aeronautical control applications. We review the theory behind this control scheme and adapt it to the case of controlling a fighter aircraft. We also provide a case study, where we test this control scheme on a simulated fighter aircraft.

  11. SUBSURFACE REPOSITORY INTEGRATED CONTROL SYSTEM DESIGN

    International Nuclear Information System (INIS)

    Randle, D.C.

    2000-01-01

    The primary purpose of this document is to develop a preliminary high-level functional and physical control system architecture for the potential repository at Yucca Mountain. This document outlines an overall control system concept that encompasses and integrates the many diverse process and communication systems being developed for the subsurface repository design. This document presents integrated design concepts for monitoring and controlling the diverse set of subsurface operations. The Subsurface Repository Integrated Control System design will be composed of a series of diverse process systems and communication networks. The subsurface repository design contains many systems related to instrumentation and control (I andC) for both repository development and waste emplacement operations. These systems include waste emplacement, waste retrieval, ventilation, radiological and air monitoring, rail transportation, construction development, utility systems (electrical, lighting, water, compressed air, etc.), fire protection, backfill emplacement, and performance confirmation. Each of these systems involves some level of I andC and will typically be integrated over a data communications network throughout the subsurface facility. The subsurface I andC systems will also interface with multiple surface-based systems such as site operations, rail transportation, security and safeguards, and electrical/piped utilities. In addition to the I andC systems, the subsurface repository design also contains systems related to voice and video communications. The components for each of these systems will be distributed and linked over voice and video communication networks throughout the subsurface facility. The scope and primary objectives of this design analysis are to: (1) Identify preliminary system-level functions and interfaces (Section 6.2). (2) Examine the overall system complexity and determine how and on what levels the engineered process systems will be monitored

  12. Kinetics and fracture resistance of lithiated silicon nanostructure pairs controlled by their mechanical interaction

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Seok Woo; /Stanford U., Geballe Lab.; Lee, Hyun-Wook; /Stanford U., Materials Sci. Dept.; Ryu, Ill; /Brown U.; Nix, William D.; /Stanford U., Materials Sci. Dept.; Gao, Huajian; /Brown U.; Cui, Yi; /Stanford U., Materials Sci. Dept. /SLAC

    2015-06-01

    Following an explosion of studies of silicon as a negative electrode for Li-ion batteries, the anomalous volumetric changes and fracture of lithiated single Si particles have attracted significant attention in various fields, including mechanics. However, in real batteries, lithiation occurs simultaneously in clusters of Si in a confined medium. Hence, understanding how the individual Si structures interact during lithiation in a closed space is necessary. Herein, we demonstrate physical/mechanical interactions of swelling Si structures during lithiation using well-defined Si nanopillar pairs. Ex situ SEM and in situ TEM studies reveal that compressive stresses change the reaction kinetics so that preferential lithiation occurs at free surfaces when the pillars are mechanically clamped. Such mechanical interactions enhance the fracture resistance of This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, Division of Materials Sciences and Engineering, under Contract No. DE-AC02-76SF00515. SLAC-PUB-16300 2 lithiated Si by lessening the tensile stress concentrations in Si structures. This study will contribute to improved design of Si structures at the electrode level for high performance Li-ion batteries.

  13. Bisphosphonates for the prevention of fractures in osteogenesis imperfecta: meta-analysis of placebo-controlled trials.

    Science.gov (United States)

    Hald, Jannie D; Evangelou, Evangelos; Langdahl, Bente L; Ralston, Stuart H

    2015-05-01

    Bisphosphonates are widely used off-label in the treatment of patients with osteogenesis imperfecta (OI) with the intention of reducing the risk of fracture. Although there is strong evidence that bisphosphonates increase bone mineral density in osteogenesis imperfecta, the effects on fracture occurrence have been inconsistent. The aim of this study was to gain a better insight into the effects of bisphosphonate therapy on fracture risk in patients with osteogenesis imperfecta by conducting a meta-analysis of randomized controlled trials in which fractures were a reported endpoint. We searched Medline, Embase, and the Cochrane Central Register of Controlled Trials in which the effects of bisphosphonates on fracture risk in osteogenesis imperfecta were compared with placebo and conducted a meta-analysis of these studies using standard methods. Heterogeneity was assessed using the I2 statistic. Six eligible studies were identified involving 424 subjects with 751 patient-years of follow-up. The proportion of patients who experienced a fracture was not significantly reduced by bisphosphonate therapy (Relative Risk [RR] = 0.83 [95% confidence interval 0.69-1.01], p = 0.06) with no heterogeneity between studies (I2  = 0). The fracture rate was reduced by bisphosphonate treatment when all studies were considered (RR = 0.71 [0.52-0.96], p = 0.02), but with considerable heterogeneity (I2  = 36%) explained by one study where a small number of patients in the placebo group experienced a large number of fractures. When this study was excluded, the effects of bisphosphonates on fracture rate was not significant (RR = 0.79 [0.61-1.02], p = 0.07, I2  = 0%). We conclude that the effects of bisphosphonates on fracture prevention in osteogenesis imperfecta are inconclusive. Adequately powered trials with a fracture endpoint are needed to further investigate the risks and benefits of bisphosphonates in this condition. © 2014 American Society for

  14. The value of arthroscopy in the treatment of complex ankle fractures - a protocol of a randomised controlled trial.

    Science.gov (United States)

    Braunstein, Mareen; Baumbach, Sebastian F; Regauer, Markus; Böcker, Wolfgang; Polzer, Hans

    2016-05-12

    An anatomical reconstruction of the ankle congruity is the important prerequisite in the operative treatment of acute ankle fractures. Despite anatomic restoration patients regularly suffer from residual symptoms after these fractures. There is growing evidence, that a poor outcome is related to the concomitant traumatic intra-articular pathology. By supplementary ankle arthroscopy anatomic reduction can be confirmed and associated intra-articular injuries can be treated. Nevertheless, the vast majority of complex ankle fractures are managed by open reduction and internal fixation (ORIF) only. Up to now, the effectiveness of arthroscopically assisted fracture treatment (AORIF) has not been conclusively determined. Therefore, a prospective randomised study is needed to sufficiently evaluate the effect of AORIF compared to ORIF in complex ankle fractures. We perform a randomised controlled trial at Munich University Clinic enrolling patients (18-65 years) with an acute ankle fracture (AO 44 A2, A3, B2, B3, C1 - C3 according to AO classification system). Patients meeting the inclusion criteria are randomised to either intervention group (AORIF, n = 37) or comparison group (ORIF, n = 37). Exclusion criteria are fractures classified as AO type 44 A1 or B1, pilon or plafond-variant injury or open fractures. Primary outcome is the AOFAS Score (American Orthopaedic Foot and Ankle Society). Secondary outcome parameter are JSSF Score (Japanese Society of Surgery of the Foot), Olerud and Molander Score, Karlsson Score, Tegner Activity Scale, SF-12, radiographic analysis, arthroscopic findings of intra-articular lesions, functional assessments, time to return to work/sports and complications. This study protocol is accordant to the SPIRIT 2013 recommendation. Statistical analysis will be performed using SPSS 22.0 (IBM). The subjective and functional outcome of complex ankle fractures is regularly unsatisfying. As these injuries are very common it is essential to

  15. Hardware design of a microcomputer controlled diagnostic vacuum controller

    International Nuclear Information System (INIS)

    Marsala, R.J.

    1983-01-01

    The TFTR diagnostic vacuum controller (DVC) has been designed and built to control and monitor the pumps, valves and gauges which comprise a diagnostic vacuum system. The DVC is a microcomputer based self-contained controller with battery backup which may be controlled manually from front panel controls or remotely via CICADA. The DVC implements all pump and valve sequencing and provides protection against incorrect operation. There are presently two versions of the DVC operating on TFTR and a third version being used on the S-1 machine

  16. Infection control in design and construction work.

    Science.gov (United States)

    Collinge, William H

    2015-01-01

    To clarify how infection control requirements are represented, communicated, and understood in work interactions through the medical facility construction project life cycle. To assist project participants with effective infection control management by highlighting the nature of such requirements and presenting recommendations to aid practice. A 4-year study regarding client requirement representation and use on National Health Service construction projects in the United Kingdom provided empirical evidence of infection control requirement communication and understanding through design and construction work interactions. An analysis of construction project resources (e.g., infection control regulations and room data sheets) was combined with semi-structured interviews with hospital client employees and design and construction professionals to provide valuable insights into the management of infection control issues. Infection control requirements are representationally indistinct but also omnipresent through all phases of the construction project life cycle: Failure to recognize their nature, relevance, and significance can result in delays, stoppages, and redesign work. Construction project resources (e.g., regulatory guidance and room data sheets) can mask or obscure the meaning of infection control issues. A preemptive identification of issues combined with knowledge sharing activities among project stakeholders can enable infection control requirements to be properly understood and addressed. Such initiatives should also reference existing infection control regulatory guidance and advice. © The Author(s) 2015.

  17. Controllable clock circuit design in PEM system

    International Nuclear Information System (INIS)

    Sun Yunhua; Wang Peihua; Hu Tingting; Feng Baotong; Shuai Lei; Huang Huan; Wei Shujun; Li Ke; Zhao Jingwei; Wei Long

    2011-01-01

    A high-precision synchronized clock circuit design will be presented, which can supply steady, reliable and anti-jamming clock signal for the data acquirement (DAQ) system of Positron Emission Mammography (PEM). This circuit design is based on the Single-Chip Microcomputer and high-precision clock chip, and can achieve multiple controllable clock signals. The jamming between the clock signals can be reduced greatly with the differential transmission. Meanwhile, the adoption of CAN bus control in the clock circuit can prompt the clock signals to be transmitted or masked simultaneously when needed. (authors)

  18. Controllable clock circuit design in PEM system

    International Nuclear Information System (INIS)

    Sun Yunhua; Wang Peilin; Hu Tingting; Feng Baotong; Shuai Lei; Huang Huan; Wei Shujun; Li Ke; Zhao Jingwei; Wei Long

    2010-01-01

    A high-precision synchronized clock circuit design will be presented, which can supply steady, reliable and anti-jamming clock signal for the data acquirement (DAQ) system of Positron Emission Mammography (PEM). This circuit design is based on the Single-Chip Microcomputer and high-precision clock chip, and can achieve multiple controllable clock signals. The jamming between the clock signals can be reduced greatly with the differential transmission. Meanwhile, the adoption of CAN bus control in the clock circuit can prompt the clock signals to be transmitted or masked simultaneously when needed. (authors)

  19. Exercise and fall prevention self-management to reduce mobility-related disability and falls after fall-related lower limb fracture in older people: protocol for the RESTORE (Recovery Exercises and STepping On afteR fracturE) randomised controlled trial.

    Science.gov (United States)

    Sherrington, Catherine; Fairhall, Nicola; Kirkham, Catherine; Clemson, Lindy; Howard, Kirsten; Vogler, Constance; Close, Jacqueline C T; Moseley, Anne M; Cameron, Ian D; Mak, Jenson; Sonnabend, David; Lord, Stephen R

    2016-02-02

    Lasting disability and further falls are common and costly problems in older people following fall-related lower limb and pelvic fractures. Exercise interventions can improve mobility after fracture and reduce falls in older people, however the optimal approach to rehabilitation after fall-related lower limb and pelvic fracture is unclear. This randomised controlled trial aims to evaluate the effects of an exercise and fall prevention self-management intervention on mobility-related disability and falls in older people following fall-related lower limb or pelvic fracture. Cost-effectiveness of the intervention will also be investigated. A randomised controlled trial with concealed allocation, assessor blinding for physical performance tests and intention-to-treat analysis will be conducted. Three hundred and fifty people aged 60 years and over with a fall-related lower limb or pelvic fracture, who are living at home or in a low care residential aged care facility and have completed active rehabilitation, will be recruited. Participants will be randomised to receive a 12-month intervention or usual care. The intervention group will receive ten home visits from a physiotherapist to prescribe an individualised exercise program with motivational interviewing, plus fall prevention education through individualised advice from the physiotherapist or attendance at the group based "Stepping On" program (seven two-hour group sessions). Participants will be followed for a 12-month period. Primary outcome measures will be mobility-related disability and falls. Secondary outcomes will include measures of balance and mobility, falls risk, physical activity, walking aid use, frailty, pain, nutrition, falls efficacy, mood, positive and negative affect, quality of life, assistance required, hospital readmission, and health-system and community-service contact. This study will determine the effect and cost-effectiveness of this exercise self management intervention on mobility

  20. Modern Control Design for Flexible Wind Turbines

    Energy Technology Data Exchange (ETDEWEB)

    Wright, A. D.

    2004-07-01

    Control can improve energy capture and reduce dynamic loads in wind turbines. In the 1970s and 1980s, wind turbines used classical control designs to regulate power and speed. The methods used, however, were not always successful. Modern turbines are larger, mounted on taller towers, and more dynamically active than their predecessors. Control systems to regulate turbine power and maintain stable, closed-loop behavior in the presence of turbulent wind inflow will be critical for these designs. This report applies modern state-space control design methods to a two-bladed teetering hub upwind machine at the National Wind Technology Center (NWTC), which is managed by the U.S. Department of Energy's National Renewable Energy Laboratory (NREL) in Golden, Colorado. The design objective is to regulate turbine speed and enhance damping in several low-damped flexible modes of the turbine. Starting with simple control algorithms based on linear models, complexity is added incrementally until the desired performance is firmly established.

  1. Robust Control Design via Linear Programming

    Science.gov (United States)

    Keel, L. H.; Bhattacharyya, S. P.

    1998-01-01

    This paper deals with the problem of synthesizing or designing a feedback controller of fixed dynamic order. The closed loop specifications considered here are given in terms of a target performance vector representing a desired set of closed loop transfer functions connecting various signals. In general these point targets are unattainable with a fixed order controller. By enlarging the target from a fixed point set to an interval set the solvability conditions with a fixed order controller are relaxed and a solution is more easily enabled. Results from the parametric robust control literature can be used to design the interval target family so that the performance deterioration is acceptable, even when plant uncertainty is present. It is shown that it is possible to devise a computationally simple linear programming approach that attempts to meet the desired closed loop specifications.

  2. SUBSURFACE REPOSITORY INTEGRATED CONTROL SYSTEM DESIGN

    International Nuclear Information System (INIS)

    C.J. Fernado

    1998-01-01

    The purpose of this document is to develop preliminary high-level functional and physical control system architectures for the proposed subsurface repository at Yucca Mountain. This document outlines overall control system concepts that encompass and integrate the many diverse systems being considered for use within the subsurface repository. This document presents integrated design concepts for monitoring and controlling the diverse set of subsurface operations. The subsurface repository design will be composed of a series of diverse systems that will be integrated to accomplish a set of overall functions and objectives. The subsurface repository contains several Instrumentation and Control (I andC) related systems including: waste emplacement systems, ventilation systems, communication systems, radiation monitoring systems, rail transportation systems, ground control monitoring systems, utility monitoring systems (electrical, lighting, water, compressed air, etc.), fire detection and protection systems, retrieval systems, and performance confirmation systems. Each of these systems involve some level of I andC and will typically be integrated over a data communication network. The subsurface I andC systems will also integrate with multiple surface-based site-wide systems such as emergency response, health physics, security and safeguards, communications, utilities and others. The scope and primary objectives of this analysis are to: (1) Identify preliminary system level functions and interface needs (Presented in the functional diagrams in Section 7.2). (2) Examine the overall system complexity and determine how and on what levels these control systems will be controlled and integrated (Presented in Section 7.2). (3) Develop a preliminary subsurface facility-wide design for an overall control system architecture, and depict this design by a series of control system functional block diagrams (Presented in Section 7.2). (4) Develop a series of physical architectures

  3. SUBSURFACE REPOSITORY INTEGRATED CONTROL SYSTEM DESIGN

    Energy Technology Data Exchange (ETDEWEB)

    C.J. Fernado

    1998-09-17

    The purpose of this document is to develop preliminary high-level functional and physical control system architectures for the proposed subsurface repository at Yucca Mountain. This document outlines overall control system concepts that encompass and integrate the many diverse systems being considered for use within the subsurface repository. This document presents integrated design concepts for monitoring and controlling the diverse set of subsurface operations. The subsurface repository design will be composed of a series of diverse systems that will be integrated to accomplish a set of overall functions and objectives. The subsurface repository contains several Instrumentation and Control (I&C) related systems including: waste emplacement systems, ventilation systems, communication systems, radiation monitoring systems, rail transportation systems, ground control monitoring systems, utility monitoring systems (electrical, lighting, water, compressed air, etc.), fire detection and protection systems, retrieval systems, and performance confirmation systems. Each of these systems involve some level of I&C and will typically be integrated over a data communication network. The subsurface I&C systems will also integrate with multiple surface-based site-wide systems such as emergency response, health physics, security and safeguards, communications, utilities and others. The scope and primary objectives of this analysis are to: (1) Identify preliminary system level functions and interface needs (Presented in the functional diagrams in Section 7.2). (2) Examine the overall system complexity and determine how and on what levels these control systems will be controlled and integrated (Presented in Section 7.2). (3) Develop a preliminary subsurface facility-wide design for an overall control system architecture, and depict this design by a series of control system functional block diagrams (Presented in Section 7.2). (4) Develop a series of physical architectures that

  4. Fracture resistance of computer-aided design and computer-aided manufacturing ceramic crowns cemented on solid abutments.

    Science.gov (United States)

    Stona, Deborah; Burnett, Luiz Henrique; Mota, Eduardo Gonçalves; Spohr, Ana Maria

    2015-07-01

    Because no information was found in the dental literature regarding the fracture resistance of all-ceramic crowns using CEREC (Sirona) computer-aided design and computer-aided manufacturing (CAD-CAM) system on solid abutments, the authors conducted a study. Sixty synOcta (Straumann) implant replicas and regular neck solid abutments were embedded in acrylic resin and randomly assigned (n = 20 per group). Three types of ceramics were used: feldspathic, CEREC VITABLOCS Mark II (VITA); leucite, IPS Empress CAD (Ivoclar Vivadent); and lithium disilicate, IPS e.max CAD (Ivoclar Vivadent). The crowns were fabricated by the CEREC CAD-CAM system. After receiving glaze, the crowns were cemented with RelyX U200 (3M ESPE) resin cement under load of 1 kilogram. For each ceramic, one-half of the specimens were subjected to the fracture resistance testing in a universal testing machine with a crosshead speed of 1 millimeter per minute, and the other half were subjected to the fractured resistance testing after 1,000,000 cyclic fatigue loading at 100 newtons. According to a 2-way analysis of variance, the interaction between the material and mechanical cycling was significant (P = .0001). According to a Tukey test (α = .05), the fracture resistance findings with or without cyclic fatigue loading were as follows, respectively: CEREC VITABLOCKS Mark II (405 N/454 N) was statistically lower than IPS Empress CAD (1169 N/1240 N) and IPS e.max CAD (1378 N/1025 N) (P Empress CAD and IPS e.max CAD did not differ statistically (P > .05). According to a t test, there was no statistical difference in the fracture resistance with and without cyclic fatigue loading for CEREC VITABLOCS Mark II and IPS Empress CAD (P > .05). For IPS e.max CAD, the fracture resistance without cyclic fatigue loading was statistically superior to that obtained with cyclic fatigue loading (P Empress CAD and IPS e.max CAD showed higher fracture resistance compared with CEREC VITABLOCS Mark II. The cyclic

  5. Bechtel automated control of design document data

    International Nuclear Information System (INIS)

    Hollingshaus, H.

    1986-01-01

    Concern for nuclear power plant safety has resulted in many design features that complicate the licensing, operation, and maintenance of nuclear plants. To manage and control the design effectively, Bechtel has developed an integrated design document data base that provides efficient support of the plant during all phases of its life. The program runs on the IBM System 38, but can also be downloaded to an IBM PC to save storage and connect time. It is interactive and can accommodate multiple users at various locations. Although primarily developed to manage design changes resulting from the regulatory process and use of a fast track construction schedule, the data base will provide operations and maintenance personnel with qualifications status and pertinent data for each piece of equipment, including all electrical devices and a list of all associated design documents

  6. Design of an adaptable nonlinear controller

    International Nuclear Information System (INIS)

    Benitez R, J.S.

    1994-01-01

    The study of the behavior of a nuclear reactor is of great importance as it allows to know a priori the conditions at which a reactor is submitted. In the sareactor are the design and simulation of control algorithms based on the theories of modern control with the objective of improving improving the performance criterions as well as to guarantee the the stability of the retrofitting system. (author)

  7. Design of Threshold Controller Based Chaotic Circuits

    DEFF Research Database (Denmark)

    Mohamed, I. Raja; Murali, K.; Sinha, Sudeshna

    2010-01-01

    We propose a very simple implementation of a second-order nonautonomous chaotic oscillator, using a threshold controller as the only source of nonlinearity. We demonstrate the efficacy and simplicity of our design through numerical and experimental results. Further, we show that this approach...... of using a threshold controller as a nonlinear element, can be extended to obtain autonomous and multiscroll chaotic attractor circuits as well....

  8. Considerations on the manner to account for fast fracture risk in the design of PWR vessels

    International Nuclear Information System (INIS)

    Pellisier-Tanon, A.; Grandemange, J.M.

    1985-08-01

    The way followed in France for analyzing fast fracture resistance of PWR primary components is the one of a deterministic analysis with safety coefficients imposed in the fracture criteria. The study of margins towards fast fracture of the 900 MWe program vessels undertaken in 1982 includes parametric evaluations of the influence of essential variables. It has stimulated further thoughts on the level of safety to fix in the analysis methodology, on the orientations for the choice of safety factors and on the manner to introduce them in the analysis. A first chapter tries to characterize the French approach in comparison to those of other countries. A second chapter examines the manner according to which safety factors can be introduced in the deterministic analysis. It presents the principle for a logical approach accounting for the interdependency of all factors and variables. It establishes criteria for the selection of defect kind and size for the computation

  9. Effects of medication reviews performed by a physician on treatment with fracture-preventing and fall-risk-increasing drugs in older adults with hip fracture-a randomized controlled study.

    Science.gov (United States)

    Sjöberg, Christina; Wallerstedt, Susanna M

    2013-09-01

    To investigate whether medication reviews increase treatment with fracture-preventing drugs and decrease treatment with fall-risk-increasing drugs. Randomized controlled trial (1:1). Departments of orthopedics, geriatrics, and medicine at Sahlgrenska University Hospital, Gothenburg, Sweden. One hundred ninety-nine consecutive individuals with hip fracture aged 65 and older. Medication reviews, based on assessments of risks of falls and fractures, regarding fracture-preventing and fall-risk-increasing drugs, performed by a physician, conveyed orally and in written form to hospital physicians during the hospital stay, and to general practitioners after discharge. Primary outcomes were changes in treatment with fracture-preventing and fall-risk-increasing drugs 12 months after discharge. Secondary outcomes were falls, fractures, deaths, and physicians' attitudes toward the intervention. At admission, 26% of intervention and 29% of control participants were taking fracture-preventing drugs, and 12% and 11%, respectively, were taking bone-active drugs, predominantly bisphosphonates. After 12 months, 77% of intervention and 58% of control participants were taking fracture-preventing drugs (P = .01), and 29% and 15%, respectively, were taking bone-active drugs (P = .04). Mean number of fall-risk-increasing drugs per participants was 3.1 (intervention) and 3.1 (control) at admission and 2.9 (intervention) and 3.1 (control) at 12 months (P = .62). No significant differences in hard endpoints were found. The responding physicians (n = 65) appreciated the intervention; on a scale from 1 (very bad) to 6 (very good), the median rating was 5 (interquartile range (IQR) 4-6) for the oral part and 5 (IQR 4-5.5) for the text part. Medication reviews performed and conveyed by a physician increased treatment with fracture-preventing drugs but did not significantly decrease treatment with fall-risk-increasing drugs in older adults with hip fracture. Prescribing physicians appreciated

  10. Controller Design Of Unicycle Mobile Robot

    Directory of Open Access Journals (Sweden)

    Mohd Zamzuri Abd Rashid

    2012-10-01

    Full Text Available ABSTRACT: The ability of unicycle mobile robot to stand and move around using one wheel has attracted a lot of researchers to conduct studies about the system, particularly in the design of the system mechanisms and the control strategies. This paper reports the investigation done on the design of the controller of the unicycle mobile robot system to maintain its stability in both longitudinal and lateral directions. The controller proposed is a Linear Quadratic Controller (LQR type which is based on the linearized model of the system. A thorough simulation studies have been carried out to find out the performance of the LQR controller. The best controller gain, K acquired through the simulation is selected to be implemented and tested in the experimental hardware. Finally, the results obtained from the experimental study are compared to the simulation results to study the controller efficacy. The analysis reveals that the proposed controller design is able to stabilize the unicycle mobile robot.ABSTRAK: Kemampuan robot satu roda untuk berdiri dan bergerak di sekitar telah menarik minat ramai penyelidik untuk mengkaji sistem robot terutamanya didalam bidang rangka mekanikal dan strategi kawalan robot. Kertas kajian ini melaporkan hasil penyelidikan ke atas strategi kawalan robot bagi memastikan sistem robot satu roda dapat distabilkan dari arah sisi dan hadapan. Strategi kawalan yang dicadang, menggunakan teknik kawalan kuadratik sejajar (Linear Quadratic Control yang berdasarkan model robot yang telah dipermudahkan. Kajian simulasi secara terperinci telah dijalankan bagi mengkaji prestasi strategi kawalan yang dicadangkan. Dari kajian simulasi sistem robot, pemilihan faktor konstan, K yang sesuai di dalam strategi kawalan telah dibuat, agar dapat dilaksanakan ke atas sistem robot yang dibangunkan. Keputusan dari kajian simulasi dan tindak balas oleh sistem robot yang dibangunkan akhirnya dibandingkan bagi melihat kesesuaian faktor kostan, K

  11. Fall with and without fracture in elderly: what's different?

    Science.gov (United States)

    Kantayaporn, Choochat

    2012-10-01

    Falling fracture was one of the health problems in elderly. This presentation aimed to identify the factors of fall that caused fractures. The retrospective case-control study was designed. Samples were all who experienced fall within 1 year in Lamphun. Factors included age, gender underlying diseases, chronic drugs used, history of parent fragility fracture, age of menopause, steroid used, body mass index, visual acuity and time up and go test were studied. Multivariate regression analysis was used. 336 cases of fractures in 1,244 cases of fall were found. Significant factors of falling fracture group that were different from fall without fracture group included age, female gender, menopause before age of 45 and visual impairment. Visual impairment was the other key factor rather than osteoporosis that caused fall with fracture. The author suggested that falling fracture prevention programs should be included correction of visual impairment other than osteoporosis treatment.

  12. Design of control system for profile gauge

    International Nuclear Information System (INIS)

    Huang Yibin; Zhang Yu'ai

    2013-01-01

    The profile gauge can on-line get the cross section in the steel strip, so it has been widely used in hot continuous rolling production-line. The structure of profile gauge and its distributed hardware structure based on PLC and software design of its control subsystem were introduced. The method of temperature and humidity measurement was analyzed. The time response of X-ray machine control based on RS232 communication was researched. It is proved that the control system meets the requirements of the profile gauge system. (authors)

  13. Intelligent Controller Design for a Chemical Process

    OpenAIRE

    Mr. Glan Devadhas G; Dr.Pushpakumar S.

    2010-01-01

    Chemical process control is a challenging problem due to the strong on*line non*linearity and extreme sensitivity to disturbances of the process. Ziegler – Nichols tuned PI and PID controllers are found to provide poor performances for higher*order and non–linear systems. This paper presents an application of one*step*ahead fuzzy as well as ANFIS (adaptive*network*based fuzzy inference system) tuning scheme for an Continuous Stirred Tank Reactor CSTR process. The controller is designed based ...

  14. Space Launch System Ascent Flight Control Design

    Science.gov (United States)

    Orr, Jeb S.; Wall, John H.; VanZwieten, Tannen S.; Hall, Charles E.

    2014-01-01

    A robust and flexible autopilot architecture for NASA's Space Launch System (SLS) family of launch vehicles is presented. The SLS configurations represent a potentially significant increase in complexity and performance capability when compared with other manned launch vehicles. It was recognized early in the program that a new, generalized autopilot design should be formulated to fulfill the needs of this new space launch architecture. The present design concept is intended to leverage existing NASA and industry launch vehicle design experience and maintain the extensibility and modularity necessary to accommodate multiple vehicle configurations while relying on proven and flight-tested control design principles for large boost vehicles. The SLS flight control architecture combines a digital three-axis autopilot with traditional bending filters to support robust active or passive stabilization of the vehicle's bending and sloshing dynamics using optimally blended measurements from multiple rate gyros on the vehicle structure. The algorithm also relies on a pseudo-optimal control allocation scheme to maximize the performance capability of multiple vectored engines while accommodating throttling and engine failure contingencies in real time with negligible impact to stability characteristics. The architecture supports active in-flight disturbance compensation through the use of nonlinear observers driven by acceleration measurements. Envelope expansion and robustness enhancement is obtained through the use of a multiplicative forward gain modulation law based upon a simple model reference adaptive control scheme.

  15. Design of POLCA material control systems

    NARCIS (Netherlands)

    Riezebos, J.

    2010-01-01

    POLCA is a material control system designed for make-to-order or engineer-to-order companies. These firms have to cope with a high variety of customised products, and strong pressure to provide short throughput times. POLCA constrains the amount of work in progress on the shop floor in order to

  16. Consys Linear Control System Design Software Package

    International Nuclear Information System (INIS)

    Diamantidis, Z.

    1987-01-01

    This package is created in order to help engineers, researchers, students and all who work on linear control systems. The software includes all time and frequency domain analysises, spectral analysises and networks, active filters and regulators design aids. The programmes are written on Hewlett Packard computer in Basic 4.0

  17. Optimal Control Design for a Solar Greenhouse

    NARCIS (Netherlands)

    Ooteghem, van R.J.C.

    2010-01-01

    Abstract: An optimal climate control has been designed for a solar greenhouse to achieve optimal crop production with sustainable instead of fossil energy. The solar greenhouse extends a conventional greenhouse with an improved roof cover, ventilation with heat recovery, a heat pump, a heat

  18. Analysis, Control and Design of Walking Robots

    NARCIS (Netherlands)

    van Oort, Gijs

    2011-01-01

    In this thesis five research questions are discussed that are related to the development of two-legged (bipedal) walking robots. The research questions are categorized in three main topics: analysis, control and actuation and design. The research questions are: - How can we analyze the behavior of a

  19. Agile Design of Sewer System Control

    NARCIS (Netherlands)

    Van Nooijen, R.P.; Kolechkina, A.G.; Van Leeuwen, P.E.R.M.; Van Velzen, E.

    2011-01-01

    We describe the first part of an attempt to include stakeholder participation in the design of a central automatic controller for a sewer system in a small pilot project (five subcatchments) and present lessons learned so far. The pilot is part of a project aimed at the improvement of water quality

  20. Fuzzy Logic Controller Design for Intelligent Robots

    Directory of Open Access Journals (Sweden)

    Ching-Han Chen

    2017-01-01

    Full Text Available This paper presents a fuzzy logic controller by which a robot can imitate biological behaviors such as avoiding obstacles or following walls. The proposed structure is implemented by integrating multiple ultrasonic sensors into a robot to collect data from a real-world environment. The decisions that govern the robot’s behavior and autopilot navigation are driven by a field programmable gate array- (FPGA- based fuzzy logic controller. The validity of the proposed controller was demonstrated by simulating three real-world scenarios to test the bionic behavior of a custom-built robot. The results revealed satisfactorily intelligent performance of the proposed fuzzy logic controller. The controller enabled the robot to demonstrate intelligent behaviors in complex environments. Furthermore, the robot’s bionic functions satisfied its design objectives.

  1. Sun Safe Mode Controller Design for LADEE

    Science.gov (United States)

    Fusco, Jesse C.; Swei, Sean S. M.; Nakamura, Robert H.

    2015-01-01

    This paper presents the development of sun safe controllers which are designed to keep the spacecraft power positive and thermally balanced in the event an anomaly is detected. Employed by NASA's Lunar Atmosphere and Dust Environment Explorer (LADEE), the controllers utilize the measured sun vector and the spacecraft body rates for feedback control. To improve the accuracy of sun vector estimation, the least square minimization approach is applied to process the sensor data, which is proven to be effective and accurate. To validate the controllers, the LADEE spacecraft model engaging the sun safe mode was first simulated and then compared with the actual LADEE orbital fight data. The results demonstrated the applicability of the proposed sun safe controllers.

  2. CV controls from design to operation

    CERN Document Server

    Blanc, D

    2002-01-01

    The cooling and Ventilation (CV) group has emphasised the need to redefine its organisational structure at the end of 98. The main objective of this operation was to ensure the CV group to be more competitive and efficient through the growing tasks of the LHC projects. The main evolution given to this reorganisation is that the new structure is more project oriented and then operates on three distinct axes: Design, Work and Operation. Process control project management requires a complete and early interaction and participation of all the actors involved. This procedure to be efficient and constructive must be considered and performed not only during the design stage but along the project planning phases and must go beyond the completion work including the process control operation activity. The paper explains the present project management for process control. It describes the present constraints and gives suggestions to a different approach to these projects to improve performances and efficiency of a contr...

  3. Designing control of a power system

    Energy Technology Data Exchange (ETDEWEB)

    Szilagyi, A.; Nemeth, A.

    1980-01-01

    With the development of Hungary's electric power system (EES) the problems of the EROTERV Institute in designing mode regulation systems grew. These systems determine the balance between the production and demand for electric power, which supports not only the maintenance of the frequency and level of voltage in the electrical grid, but also determines the stability of the operation of the electric power system as a whole. A review is cited of the design solutions to control systems in a chronological order. Certain characteristic problems in contemporary control of operational modes of the electric power system are examined and their the trends in their future improvement are determined. The structural layout of mode control systems are cited.

  4. HETDEX tracker control system design and implementation

    Science.gov (United States)

    Beno, Joseph H.; Hayes, Richard; Leck, Ron; Penney, Charles; Soukup, Ian

    2012-09-01

    To enable the Hobby-Eberly Telescope Dark Energy Experiment, The University of Texas at Austin Center for Electromechanics and McDonald Observatory developed a precision tracker and control system - an 18,000 kg robot to position a 3,100 kg payload within 10 microns of a desired dynamic track. Performance requirements to meet science needs and safety requirements that emerged from detailed Failure Modes and Effects Analysis resulted in a system of 13 precision controlled actuators and 100 additional analog and digital devices (primarily sensors and safety limit switches). Due to this complexity, demanding accuracy requirements, and stringent safety requirements, two independent control systems were developed. First, a versatile and easily configurable centralized control system that links with modeling and simulation tools during the hardware and software design process was deemed essential for normal operation including motion control. A second, parallel, control system, the Hardware Fault Controller (HFC) provides independent monitoring and fault control through a dedicated microcontroller to force a safe, controlled shutdown of the entire system in the event a fault is detected. Motion controls were developed in a Matlab-Simulink simulation environment, and coupled with dSPACE controller hardware. The dSPACE real-time operating system collects sensor information; motor commands are transmitted over a PROFIBUS network to servo amplifiers and drive motor status is received over the same network. To interface the dSPACE controller directly to absolute Heidenhain sensors with EnDat 2.2 protocol, a custom communication board was developed. This paper covers details of operational control software, the HFC, algorithms, tuning, debugging, testing, and lessons learned.

  5. Microstructural design in quenched and partitioned (Q&P) steels to improve their fracture properties

    International Nuclear Information System (INIS)

    Diego-Calderón, I. de; Sabirov, I.; Molina-Aldareguia, J.M.; Föjer, C.; Thiessen, R.; Petrov, R.H.

    2016-01-01

    Quenching and partitioning (Q&P) is receiving increased attention as a novel heat treatment to produce advanced high strength steels (AHSSs) containing martensite/retained austenite mixtures, with desirable combination of strength, ductility and toughness. Despite the significant body of research on microstructure and mechanical properties of Q&P steels, there is still a significant lack of knowledge on the effect of complex microstructure on their mechanical performance. This work addresses the effect of microstructural architecture in multiphase Q&P steels on their fracture behavior at macro- and micro-scales. It is demonstrated that the RA volume fraction does not affect significantly the local fracture initiation toughness, whereas it can greatly improve the total crack growth resistance in Q&P steels. In addition, matrix conditions can play an important role in the fracture behavior of Q&P steels. Based on the analysis of the experimental results, a general recipe to tailor fracture properties of Q&P steels is proposed.

  6. Mortality analysis in hip fracture patients: implications for design of future outcome trials

    DEFF Research Database (Denmark)

    Foss, N B; Kehlet, H

    2006-01-01

    Patients with hip fractures are usually frail and elderly with a 30-day mortality in excess of 10% in European series. Perioperative morbidity is often multifactorial in nature, and unimodal interventions will not necessarily decrease mortality. The purpose of this prospective study was to analys...

  7. Design of controller for control rod of research reactors

    International Nuclear Information System (INIS)

    Abou-Zaid, R.M.F.M

    2008-01-01

    Designing and testing digital control system for any nuclear research reactor can be costly and time consuming. In this thesis, a rapid, low-cost proto typing and testing procedure for digital controller design is proposed using the concept of Hardware-In-The-Loop (HIL). Some of the control loop components are real hardware components and the others are simulated. First, the whole system is modeled and tested by Real-Time Simulation (RTS) using conventional simulation techniques such as MATLAB / SIMULINK. Second the Hardware-in-the-loop simulation is tested using Real-Time Windows Target in MATLAB and Visual C ++ . The control parts are included as hardware components which are the reactor control rod and its drivers. Three kinds of controllers are studied, Proportional-Derivative (PD), Proportional-Integral-Derivative (PID) and Fuzzy controller. An experimental setup for the hardware used in HIL concept for the control of the nuclear research reactor has been realized. Experimental results are obtained and compared with the simulation results. The experimental results indicate the validation of HIL method in this domain.

  8. Design of Air Traffic Control Operation System

    Directory of Open Access Journals (Sweden)

    Gabriela STROE

    2017-09-01

    Full Text Available This paper presents a numerical simulation for a different aircraft, based on the specific aircraft data that can be incorporated in the model and the equations of motions which can be consequently solved. The aircraft flight design involves various technical steps and requires the use of sophisticated software having modeling and simulation capabilities. Within the flight simulation model, the aerodynamic model can be regarded as the most complex and most important. With appropriate aerodynamic modeling the aerodynamic forces and moments acting on the aircraft's center of gravity can be numerically solved with accuracy. These forces and moments are further used to solve the equations of motion. The development of control and computing technology makes it possible for advanced flight control strategy. The advanced control techniques tend to make the control design and their implementation much more complicated with more control loops or channels; in this line, the autopilot of modern aircrafts includes a variety of automatic control systems that aid and support the flight navigation, flight management, and perform the enhancing and/or augmenting of the stability characteristics of the airplane. Therefore in this context it is very important to choose the dynamic that will satisfy the performance and robustness specifications.

  9. MSM actuators: design rules and control strategies

    Energy Technology Data Exchange (ETDEWEB)

    Holz, Benedikt; Janocha, Hartmut [Laboratory of Process Automation (LPA), Saarland University, Saarbruecken (Germany); Riccardi, Leonardo; Naso, David [Department of Electronics and Electrical Science (DEE), Politecnico di Bari (Italy)

    2012-08-15

    Magnetic shape memory (MSM) alloys are comparatively new active materials which can be used for several industrial applications, ranging from precise positioning systems to advanced robotics. Beyond the material research, which deals with the basic thermo-magneto-mechanical properties of the crystals, the design as well as the control of the actuators displacement is an essential challenge. This paper addresses those two topics, trying to give to the reader a useful overview of existing results, but also presents new ideas. First, it introduces and discusses in details some possible designs, with a special emphasis on innovative actuator design concepts which are able to exploit the particular potentialities of MSM elements. The second focus of the paper is on the problem of designing a controller, i.e., an algorithm that allows to obtain a required performance from the actuator. The proposed control strategies try to take into account two main characteristics of MSM elements: the hysteresis and the temperature dependence. The effectiveness of the strategies is emphasized by experimental results performed on a commercially available MSM actuator demonstrator. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  10. Parameters controlling fracturing distribution: example of an Upper Jurassic marly-calcareous formation (eastern Paris Basin); Parametres controlant la distribution de la fracturation: exemple dans une serie marno-calcaire du Jurassique superieur (Est du bassin de Paris)

    Energy Technology Data Exchange (ETDEWEB)

    Andre, G.; Rebours, H.; Wileveau, Y. [Agence Nationale pour la Gestion des Dechets Radioactifs (ANDRA), Laboratoire de recherche souterrain de Meuse/Haute-Marne, 55 - Bure (France); Proudhon, B. [GEO.TER, 34 - Clapiers (France)

    2006-10-15

    Study of fractures along a 490-m vertical section of marl/limestone alternations in the Upper Jurassic (Meuse/Haute-Marne underground research laboratory-eastern Paris Basin) reveals their organization and the different states of palaeo-stress. Type and extension of tectonic structures seem to be controlled principally by lithology and secondary by depth. Also, it appears deviations of Alpine palaeo-stresses between Kimmeridgian and Oxfordian formations. These deviations are related to the presence of marl/limestone contacts. The vertical evolution of current horizontal maximum stress shows a similar behaviour, with deviations at the walls of Callovo-Oxfordian argilites. These results allow us to point out and to discuss the impact of lithology, rheology and depth on fracturing occurrence and distribution. Furthermore, this study suggests the role of Callovo-Oxfordian as a barrier for fracture development between the limestones of Dogger and Oxfordian formations. (authors)

  11. Serum vitamin E concentrations among highly functioning hip fracture patients are higher than in nonfracture controls

    OpenAIRE

    D’Adamo, Christopher R.; Shardell, Michelle D.; Hicks, Gregory E.; Orwig, Denise L.; Hochberg, Marc C.; Semba, Richard D.; Yu-Yahiro, Janet A.; Ferrucci, Luigi; Magaziner, Jay S.; Miller, Ram R.

    2011-01-01

    Malnutrition after hip fracture is common and associated with poor outcomes and protracted recovery. Low concentrations of vitamin E have been associated with incident decline in physical function among older adults and may, therefore, be particularly important to functionally compromised patients hip fracture patients. Serum concentrations of α-tocopherol and γ-tocopherol, the 2 major forms of vitamin E, were assessed in 148 female hip fracture patients 65 years or older from the Baltimore H...

  12. Anchorage strategies in geriatric hip fracture management

    Directory of Open Access Journals (Sweden)

    Knobe Matthias

    2016-12-01

    Full Text Available There is an enormous humanitarian and socioeconomic need to improve the quality and effectiveness of care for patients with hip fracture. To reduce mechanical complications in the osteosynthesis of proximal femoral fractures, improved fixation techniques have been developed including blade or screw-anchor devices, locked minimally invasive or cement augmentation strategies. However, despite numerous innovations and advances regarding implant design and surgical techniques, systemic and mechanical complication rates remain high. Treatment success depends on secure implant fixation in often-osteoporotic bone as well as on patient-specific factors (fracture stability, bone quality, comorbidity, and gender and surgeon-related factors (experience, correct reduction, and optimal screw placement in the head/neck fragment. For fracture fixation, the anchorage of the lag screw within the femoral head plays a crucial role depending on the implant’s design. Meta-analyses and randomized controlled studies demonstrate that there is a strong trend towards arthroplasty treating geriatric femoral neck fractures. However, for young adults as well as older patients with less compromised bone quality, or in undisplaced fractures, head-preserving therapy is preferred as it is less invasive and associated with good functional results. This review summarizes the evidence for the internal fixation of femoral neck fractures and trochanteric femoral fractures in elderly patients. In addition, biomechanical considerations regarding implant anchorage in the femoral head including rotation, migration, and femoral neck shortening are made. Finally, cement augmentation strategies for hip fracture implants are evaluated critically.

  13. Design and Realization of Intelligent Flow Controller

    Directory of Open Access Journals (Sweden)

    Jianxiong Ye

    2014-09-01

    Full Text Available According to accurate flow rate control requirements in large irrigation zone, a fuzzy controller with dead-band is designed on the characteristics analysis and comparison of PID and Fuzzy. The setting values of water flow for gates are determined by real-time water level detection sensors, and the realistic value of discharged water and gate opening are detected out with relative sensors, simulation manifest that the specific control strategy can adjust the gate swiftly in circumstance of huge offset, and regulate the gate slightly in time of small bias, it is realized with Siemens S315 PLC (Programmable Logical Controller and has being working steadily for 2 years, the aim of regulation is performed properly.

  14. A Biomechanical Study Comparing Helical Blade with Screw Design for Sliding Hip Fixations of Unstable Intertrochanteric Fractures

    Directory of Open Access Journals (Sweden)

    Qiang Luo

    2013-01-01

    Full Text Available Dynamic hip screw (DHS is a well-established conventional implant for treating intertrochanteric fracture. However, revision surgery sometimes still occurs due to the cutting out of implants. A helical blade instead of threaded screw (DHS blade was designed to improve the fixation power of the osteoporotic intertrochanteric fracture. In this study, the biomechanical properties of DHS blade compared to the conventional DHS were evaluated using an unstable AO/OTA 31-A2 intertrochanteric fracture model. Fifty synthetic proximal femoral bone models with such configuration were fixed with DHS and DHS blade in five different positions: centre-centre (CC, superior-centre (SC, inferior-center (IC, centre-anterior (CA, and centre-posterior (CP. All models had undergone mechanical compression test, and the vertical and rotational displacements were recorded. The results showed that DHS blade had less vertical or rotational displacement than the conventional DHS in CC, CA, and IC positions. The greatest vertical and rotational displacements were found at CP position in both groups. Overall speaking, DHS blade was superior in resisting vertical or rotational displacement in comparison to conventional DHS, and the centre-posterior position had the poorest performance in both groups.

  15. Functional results following fractures of the proximal humerus. A controlled clinical study comparing two periods of immobilization

    DEFF Research Database (Denmark)

    Kristiansen, B; Angermann, P; Larsen, T K

    1989-01-01

    In order to compare 1 and 3 weeks of immobilization following proximal humeral fractures a prospective controlled trial was performed in 85 patients. Clinical follow-up according to the Neer assessment system was done after 1, 3, 6, 12, and 24 months. One week of immobilization resulted in a better...

  16. Future control room design (modernization of control room systems)

    International Nuclear Information System (INIS)

    Reischl, Ludwig; Freitag, Timo; Dergel, Rene

    2009-01-01

    In the frame of lifetime extension for nuclear power plants the modernization of the complete safety and operational control technology will be digitalized. It is also recommended to modernize the operator facilities, monitoring systems in the control room, the back-up shut-down center and the local control stations. The authors summarize the reasons for the modernization recommendations and discuss possible solutions for display-oriented control rooms. A concept for control room backfitting includes generic requirements, requirements of the local authorities, ergonomic principles information content and information density, and the design process. The backfitting strategy should include a cooperation with the operational personnel, The quality assurance and training via simulator needs sufficient timing during the implementation of the backfitting.

  17. Combating obsolescence - ACR digital control systems design

    International Nuclear Information System (INIS)

    Tikku, S.; Raiskums, G.

    2006-01-01

    The ever increasing use of digital technologies and products to meet the control, automation and monitoring needs of the nuclear power plant - even though justified by the benefits it provides - comes with an increased risk of technological obsolescence happening through the course of the plant life. Some well considered strategies are being employed in the ACR design process to minimise this risk and alleviate the consequence if it happens. These include application of a modular overall architecture, adoption of international widely accepted standards to harmonise equipment qualification and software practices, production of control functional specifications that are not influenced by target platform, and careful selection of technologies and products. (author)

  18. Designer's handbook of instrumentation and control circuits

    CERN Document Server

    Carr, Joseph J

    1991-01-01

    Here is a comprehensive, practical guide to the entire process of analog instrumentation and control, from sensor input to data conversion circuitry and final output. This readable handbook avoids complex mathematical treatments, instead taking an applications-oriented approach and presenting many sample circuits and concrete examples. It is an essential reference for engineers and high-level technicians in a variety of scientific and engineering fields--anywhere data is collected electronically and where such data is used to control physical processes.Key Features* Covers design o

  19. Hospital design for better infection control

    Directory of Open Access Journals (Sweden)

    Lateef Fatimah

    2009-01-01

    Full Text Available The physical design and infrastructure of a hospital or institution is an essential component of its infection control measure. Thus is must be a prerequisite to take these into consideration from the initial conception and planning stages of the building. The balance between designing a hospital to be an open, accessible and public place and the control to reduce the spread of infections diseases is a necessity. At Singapore General Hospital, many lessons were learnt during the SARS outbreak pertaining to this. During and subsequent to the SARS outbreak, many changes evolved in the hospital to enable us to handle and face any emerging infectious situation with calm, confidence and the knowledge that staff and patients will be in good stead. This paper will share some of our experiences as well as challenges

  20. Design and control of swarm dynamics

    CERN Document Server

    Bouffanais, Roland

    2016-01-01

    The book is about the key elements required for designing, building and controlling effective artificial swarms comprised of multiple moving physical agents. Therefore this book presents the fundamentals of each of those key elements in the particular frame of dynamic swarming, specifically exposing the profound connections between these elements and establish some general design principles for swarming behaviors. This scientific endeavor requires an inter-disciplinary approach: biomimetic inspiration from ethology and ecology, study of social information flow, analysis of temporal and adaptive signaling network of interaction, considerations of control of networked real-time systems, and lastly, elements of complex adaptive dynamical systems. This book offers a completely new perspective on the scientific understanding of dynamic collective behaviors thanks to its multi-disciplinary approach and its focus on artificial swarm of physical agents. Two of the key problems in understanding the emergence of swarm ...

  1. Long life reaction control system design

    Science.gov (United States)

    Fanciullo, Thomas J.; Judd, Craig

    1993-02-01

    Future single stage to orbit systems will utilize oxygen/hydrogen propellants in their main propulsion means due to the propellant's high energy content and environmental acceptability. Operational effectiveness studies and life cycle cost studies have indicated that minimizing the number of different commodities on a given vehicle not only reduces cost, but reduces the ground span times in both the pre- and postflight operations. Therefore, oxygen and hydrogen should be used for the reaction controls systems, eliminating the need to deal with toxic or corrosive fluids. When the hydrogen scramjet powered NASP design development began in 1985, new system design studies considered overall integration of subsystems; in the context of that approach, O2/H2 reaction controls system were more than competitive with storable propellant systems and had the additional benefits of lower life cycle cost, rapid turnaround times, and O2 and H2 commodities for use throughout the vehicle. Similar benefits were derived in rocket-powered SSTO vehicles.

  2. Control system design for UAV trajectory tracking

    Science.gov (United States)

    Wang, Haitao; Gao, Jinyuan

    2006-11-01

    In recent years, because of the emerging requirements for increasing autonomy, the controller of uninhabited air vehicles must be augmented with a very sophisticated autopilot design which is capable of tracking complex and agile maneuvering trajectory. This paper provides a simplified control system framework to solve UAV maneuvering trajectory tracking problem. The flight control system is divided into three subsystems including command generation, transformation and allocation. According to the kinematics equations of the aircraft, flight path angle commands can be generated by desired 3D position from path planning. These commands are transformed to body angular rates through direct nonlinear mapping, which is simpler than common multi-loop method based on time scale separation assumption. Then, by using weighted pseudo-inverse method, the control surface deflections are allocated to follow body angular rates from the previous step. In order to improve the robustness, a nonlinear disturbance observer-based approach is used to compensate the uncertainty of system. A 6DOF nonlinear UAV model is controlled to demonstrate the performance of the trajectory tracking control system. Simulation results show that the control strategy is easy to be realized and the precision of tracking is satisfying.

  3. Multi-zone coupling productivity of horizontal well fracturing with complex fracture networks in shale gas reservoirs

    Directory of Open Access Journals (Sweden)

    Weiyao Zhu

    2018-02-01

    best. Therefore, it is necessary to control fracturing degree reasonably and optimize fracturing parameters, so as to provide a theoretical support for the optimization design of shale gas reservoir fracturing. Keywords: Shale gas, Reservoir, Fracturing, Horizontal well, Complex fracture network, Multi-zone coupling, Multi-scale, Interference, Productivity capacity

  4. Advanced Control Considerations for Turbofan Engine Design

    Science.gov (United States)

    Connolly, Joseph W.; Csank, Jeffrey T.; Chicatelli, Amy

    2016-01-01

    This paper covers the application of a model-based engine control (MBEC) methodology featuring a self tuning on-board model for an aircraft turbofan engine simulation. The nonlinear engine model is capable of modeling realistic engine performance, allowing for a verification of the advanced control methodology over a wide range of operating points and life cycle conditions. The on-board model is a piece-wise linear model derived from the nonlinear engine model and updated using an optimal tuner Kalman Filter estimation routine, which enables the on-board model to self-tune to account for engine performance variations. MBEC is used here to show how advanced control architectures can improve efficiency during the design phase of a turbofan engine by reducing conservative operability margins. The operability margins that can be reduced, such as stall margin, can expand the engine design space and offer potential for efficiency improvements. Application of MBEC architecture to a nonlinear engine simulation is shown to reduce the thrust specific fuel consumption by approximately 1% over the baseline design, while maintaining safe operation of the engine across the flight envelope.

  5. Design of barrier bucket kicker control system

    Science.gov (United States)

    Ni, Fa-Fu; Wang, Yan-Yu; Yin, Jun; Zhou, De-Tai; Shen, Guo-Dong; Zheng, Yang-De.; Zhang, Jian-Chuan; Yin, Jia; Bai, Xiao; Ma, Xiao-Li

    2018-05-01

    The Heavy-Ion Research Facility in Lanzhou (HIRFL) contains two synchrotrons: the main cooler storage ring (CSRm) and the experimental cooler storage ring (CSRe). Beams are extracted from CSRm, and injected into CSRe. To apply the Barrier Bucket (BB) method on the CSRe beam accumulation, a new BB technology based kicker control system was designed and implemented. The controller of the system is implemented using an Advanced Reduced Instruction Set Computer (RISC) Machine (ARM) chip and a field-programmable gate array (FPGA) chip. Within the architecture, ARM is responsible for data presetting and floating number arithmetic processing. The FPGA computes the RF phase point of the two rings and offers more accurate control of the time delay. An online preliminary experiment on HIRFL was also designed to verify the functionalities of the control system. The result shows that the reference trigger point of two different sinusoidal RF signals for an arbitrary phase point was acquired with a matched phase error below 1° (approximately 2.1 ns), and the step delay time better than 2 ns were realized.

  6. Design of SPring-8 control system

    International Nuclear Information System (INIS)

    Wada, T.; Kumahara, T.; Yonehara, H.; Yoshikawa, H.; Masuda, T.; Wang Zhen

    1992-01-01

    The control system of SPring-8 facility is designed. A distributed computer system is adopted with a three-hierarchy levels. All the computers are linked by computer networks. The network of upper level is a high-speed multi-media LAN such as FDDI which links sub-system control computers, and middle are Ethernet or MAP networks which link front end processors (FEP) such as VME system. The lowest is a field level bus which links VME and controlled devices. Workstations (WS) or X-terminals are useful for man-machine interfaces. For operating system (OS), UNIX is useful for upper level computers, and real-time OS's for FEP's. We will select hardwares and OS of which specifications are close to international standards. Since recently the cost of software has become higher than that of hardware, we introduce computer aided tools as many as possible for program developments. (author)

  7. Controller design approach based on linear programming.

    Science.gov (United States)

    Tanaka, Ryo; Shibasaki, Hiroki; Ogawa, Hiromitsu; Murakami, Takahiro; Ishida, Yoshihisa

    2013-11-01

    This study explains and demonstrates the design method for a control system with a load disturbance observer. Observer gains are determined by linear programming (LP) in terms of the Routh-Hurwitz stability criterion and the final-value theorem. In addition, the control model has a feedback structure, and feedback gains are determined to be the linear quadratic regulator. The simulation results confirmed that compared with the conventional method, the output estimated by our proposed method converges to a reference input faster when a load disturbance is added to a control system. In addition, we also confirmed the effectiveness of the proposed method by performing an experiment with a DC motor. © 2013 ISA. Published by ISA. All rights reserved.

  8. Higher Fish Intake Is Associated with a Lower Risk of Hip Fractures in Chinese Men and Women: A Matched Case-Control Study

    OpenAIRE

    Fan, Fan; Xue, Wen-Qiong; Wu, Bao-Hua; He, Ming-Guang; Xie, Hai-Li; Ouyang, Wei-Fu; Tu, Su-lan; Chen, Yu-Ming

    2013-01-01

    OBJECTIVES: Fish is rich in nutrients that are favorable to bone health, but limited data are available regarding the relationship between fish intake and hip fractures. Our study examined the association between habitual fish intake and risk of hip fractures. METHODS: A case-control study was performed between June 2009 and June 2012 in Guangdong Province, China. Five hundred and eighty-one hip fracture incident cases, aged 55 to 80 years (mean: 71 years), were enrolled from four hospitals. ...

  9. Fascia iliaca compartment blockade for acute pain control in hip fracture patients

    DEFF Research Database (Denmark)

    Foss, Nicolai B; Kristensen, Billy B; Bundgaard, Morten

    2007-01-01

    Hip fracture patients are in severe pain upon arrival at the emergency department. Pain treatment is traditionally based on systemic opioids. No study has examined the effect of fascia iliaca compartment blockade (FICB) in acute hip fracture pain management within a double-blind, randomized setup....

  10. What controls diffuse fractures in platform carbonates? Insights from Provence (France) and Apulia (Italy)

    Science.gov (United States)

    Lavenu, Arthur P. C.; Lamarche, Juliette

    2018-03-01

    Fractures are widespread in rocks and regional opening-mode arrays are commonly ascribed to major tectonic events. However, fractures occur in otherwise undeformed rocks. Some of these are early-developed features independent of tectonics and forming a background network at regional scale. To overcome this lack of understanding, two hydrocarbon reservoir analogues from platform carbonates have been targeted: the Provence (SE France), and the Apulian platform (SE Italy). In both areas, an early fracturing stage has been observed, made of high-angle-to-bedding opening-mode fractures, and bed-parallel stylolites. These features developed synchronously during the first burial stages and prior to major tectonic events. The fracture sets are not genetically related to the present-day layering. Contrarily, fractures developed in a brittle media where facies transitions were not sharp and did not act as mechanical discontinuities. Carbonate facies distribution and early diagenetic imprint constrained the mechanical stratigraphy when fractures occurred. In addition, we observed that fractures related to late tectonic inversion were partly inhibited. Indeed, rock mechanical properties change through time. Characterizing the temporal evolution of carbonate rocks has revealed that diagenesis and sedimentary facies are the prime actors for brittleness and mechanical layering in carbonates.

  11. Numerical Approach for Goaf-Side Entry Layout and Yield Pillar Design in Fractured Ground Conditions

    Science.gov (United States)

    Jiang, Lishuai; Zhang, Peipeng; Chen, Lianjun; Hao, Zhen; Sainoki, Atsushi; Mitri, Hani S.; Wang, Qingbiao

    2017-11-01

    Entry driven along goaf-side (EDG), which is the development of an entry of the next longwall panel along the goaf-side and the isolation of the entry from the goaf with a small-width yield pillar, has been widely employed in China over the past several decades . The width of such a yield pillar has a crucial effect on EDG layout in terms of the ground control, isolation effect and resource recovery rate. Based on a case study, this paper presents an approach for evaluating, designing and optimizing EDG and yield pillar by considering the results from numerical simulations and field practice. To rigorously analyze the ground stability, the numerical study begins with the simulation of goaf-side stress and ground conditions. Four global models with identical conditions, except for the width of the yield pillar, are built, and the effect of pillar width on ground stability is investigated by comparing aspects of stress distribution, failure propagation, and displacement evolution during the entire service life of the entry. Based on simulation results, the isolation effect of the pillar acquired from field practice is also considered. The suggested optimal yield pillar design is validated using a field test in the same mine. Thus, the presented numerical approach provides references and can be utilized for the evaluation, design and optimization of EDG and yield pillars under similar geological and geotechnical circumstances.

  12. Posterior paramedian subrhomboidal analgesia versus thoracic epidural analgesia for pain control in patients with multiple rib fractures.

    Science.gov (United States)

    Shelley, Casey L; Berry, Stepheny; Howard, James; De Ruyter, Martin; Thepthepha, Melissa; Nazir, Niaman; McDonald, Tracy; Dalton, Annemarie; Moncure, Michael

    2016-09-01

    Rib fractures are common in trauma admissions and are associated with an increased risk of pulmonary complications, intensive care unit admissions, and mortality. Providing adequate pain control in patients with multiple rib fractures decreases the risk of adverse events. Thoracic epidural analgesia is currently the preferred method for pain control. This study compared outcomes in patients with multiple acute rib fractures treated with posterior paramedian subrhomboidal (PoPS) analgesia versus thoracic epidural analgesia (TEA). This prospective study included 30 patients with three or more acute rib fractures admitted to a Level I trauma center. Thoracic epidural analgesia or PoPS catheters were placed, and local anesthesia was infused. Data were collected including patients' pain level, adjunct morphine equivalent use, adverse events, length of stay, lung volumes, and discharge disposition. Nonparametric tests were used and two-sided p Pain rating was lower in the PoPS group (2.5 vs. 5; p = 0.03) after initial placement. Overall, there was no other statistically significant difference in pain control or use of oral morphine adjuncts between the groups. Hypotension occurred in eight patients, 75% with TEA and only 25% with PoPS. No difference was found in adverse events, length of stay, lung volumes, or discharge disposition. In patients with rib fractures, PoPS analgesia may provide pain control equivalent to TEA while being less invasive and more readily placed by a variety of hospital staff. This pilot study is limited by its small sample size, and therefore additional studies are needed to prove equivalence of PoPS compared to TEA. Therapeutic study, level IV.

  13. Risk factors for falls with severe fracture in elderly people living in a middle-income country: a case control study

    Directory of Open Access Journals (Sweden)

    Bloch Katia V

    2008-08-01

    Full Text Available Abstract Background Fracture after falling has been identified as an important problem in public health. Most studies of risk factors for fractures due to falls have been carried out in developed countries, although the size of the elderly population is increasing fast in middle income countries. The objective of this paper is to identify risk factors for fall related to severe fractures in those aged 60 or more in a middle-income country. Methods A case-control study was carried out in Rio de Janeiro-Brazil based general hospitals between 2002–2003. Two hundred-fifty hospitalised cases of fracture were matched with 250 community controls by sex, age group and living area. Data were collected for socio-demographic variables, health status and drugs used before the fall. A conditional logistic regression model was fitted to identify variables associated with the risk of fall related severe fracture. Results Low body mass index, cognitive impairment, stroke and lack of urine control were associated with increased risk of severe fall related fractures. Benzodiazepines and muscle relaxants were also related to an increased risk of severe fractures while moderate use of alcohol was associated with reduced risk. Conclusion Although the association between benzodiazepines and fractures due to fall has been consistently demonstrated for old people, this has not been the case for muscle relaxant drugs. The decision to prescribe muscle relaxants for elderly people should take into account the risk of severe fracture associated with these drugs.

  14. Risk factors for falls with severe fracture in elderly people living in a middle-income country: a case control study.

    Science.gov (United States)

    Coutinho, Evandro S F; Fletcher, Astrid; Bloch, Katia V; Rodrigues, Laura C

    2008-08-26

    Fracture after falling has been identified as an important problem in public health. Most studies of risk factors for fractures due to falls have been carried out in developed countries, although the size of the elderly population is increasing fast in middle income countries. The objective of this paper is to identify risk factors for fall related to severe fractures in those aged 60 or more in a middle-income country. A case-control study was carried out in Rio de Janeiro-Brazil based general hospitals between 2002-2003. Two hundred-fifty hospitalised cases of fracture were matched with 250 community controls by sex, age group and living area. Data were collected for socio-demographic variables, health status and drugs used before the fall. A conditional logistic regression model was fitted to identify variables associated with the risk of fall related severe fracture. Low body mass index, cognitive impairment, stroke and lack of urine control were associated with increased risk of severe fall related fractures. Benzodiazepines and muscle relaxants were also related to an increased risk of severe fractures while moderate use of alcohol was associated with reduced risk. Although the association between benzodiazepines and fractures due to fall has been consistently demonstrated for old people, this has not been the case for muscle relaxant drugs. The decision to prescribe muscle relaxants for elderly people should take into account the risk of severe fracture associated with these drugs.

  15. Solar Power Station Output Inverter Control Design

    Directory of Open Access Journals (Sweden)

    J. Bauer

    2011-04-01

    Full Text Available The photovoltaic applications spreads in these days fast, therefore they also undergo great development. Because the amount of the energy obtained from the panel depends on the surrounding conditions, as intensity of the sun exposure or the temperature of the solar array, the converter must be connected to the panel output. The Solar system equipped with inverter can supply small loads like notebooks, mobile chargers etc. in the places where the supplying network is not present. Or the system can be used as a generator and it shall deliver energy to the supply network. Each type of the application has different requirements on the converter and its control algorithm. But for all of them the one thing is common – the maximal efficiency. The paper focuses on design and simulation of the low power inverter that acts as output part of the whole converter. In the paper the design of the control algorithm of the inverter for both types of inverter application – for islanding mode and for operation on the supply grid – is discussed. Attention is also paid to the design of the output filter that should reduce negative side effects of the converter on the supply network.

  16. Control-matrix approach to stellarator design and control

    International Nuclear Information System (INIS)

    Mynick, H. E.; Pomphrey, N.

    2000-01-01

    The full space Z(equivalent to){Z j=1,...,Nz } of independent variables defining a stellarator configuration is large. To find attractive design points in this space, or to understand operational flexibility about a given design point, one needs insight into the topography in Z-space of the physics figures of merit P i which characterize the machine performance, and means of determining those directions in Z-space which give one independent control over the P i , as well as those which affect none of them, and so are available for design flexibility. The control matrix (CM) approach described here provides a mathematical means of obtaining these. In this work, the CM approach is described and used in studying some candidate Quasi-Axisymmetric (QA) stellarator configurations the National Compact Stellarator Experiment design group has been considering. In the process of the analysis, a first exploration of the topography of the configuration space in the vicinity of these candidate systems has been performed, whose character is discussed

  17. Control-matrix approach to stellarator design and control

    International Nuclear Information System (INIS)

    Mynick, H.E.; Pomphrey, N.

    2000-01-01

    The full space Z always equal to {Zj=1,..Nz} of independent variables defining a stellarator configuration is large. To find attractive design points in this space, or to understand operational flexibility about a given design point, one needs insight into the topography in Z-space of the physics figures of merit Pi which characterize the machine performance, and means of determining those directions in Z-space which give one independent control over the Pi, as well as those which affect none of them, and so are available for design flexibility. The control matrix (CM) approach described here provides a mathematical means of obtaining these. In this work, the authors describe the CM approach and use it in studying some candidate Quasi-Axisymmetric (QA) stellarator configurations the NCSX design group has been considering. In the process of the analysis, a first exploration of the topography of the configuration space in the vicinity of these candidate systems has been performed, whose character is discussed

  18. Selection of pipeline steels with an engineering fracture mechanical analysis

    Energy Technology Data Exchange (ETDEWEB)

    Stenbacka, N [Swedish State Power Board, Vaellingby

    1985-01-01

    Selection of pipeline steels is discussed on the basis of two mutually independent failure mechanisms: elastic fracture and plastic collapse. The presentation is restricted to axial flaws. A formal analysis shows that brittle fracture in modern pipelines has no high priority in design, since steels used today have a high fracture toughness. Instead, a case of practical concern is tha plastic collapse mode, where failure is flow stress controlled. Conditions governing this design case are specified. In conjunction with this, criterions for material selection with regard to fracture toughness is presented.

  19. Modern control room design experience and speculation

    International Nuclear Information System (INIS)

    Smith, J.E.

    1993-01-01

    Can operators trained to use conventional control panels readily adapt to CRT based control rooms? Does automation make the design of good man-machine interfaces more or less difficult? In a conventional, hard-wired control room is the operator's peripheral vision always an asset and how can one do better in a CRT based control room? Are Expert System assisted man-machine interfaces a boon or a bust? This paper explores these questions in the light of actual experience with advanced power plant control environments. This paper discusses how automation has in fact simplified the problem of ensuring that the operator has at all times a clear understanding of the plant state. The author contends that conventional hard-wired control rooms are very poor at providing the operator with a good overview of the plant status particularly under startup, or upset conditions and that CRT-based control rooms offer an opportunity for improvement. Experience with some early attempts at this are discussed together with some interesting proposals from other authors. Finally the paper discusses the experience to date with expert system assisted man-machine interfaces. Although promising for the future progress has been slow. The amount of knowledge research required is often formidable and consequently costly. Often when an adequate knowledge base is finally acquired it turns out to be better to use it to increase the level of automation and thus simplify the operator's task. The risks are not any greater and automation offers more consistent operation. It is important also to carefully distinguish between expert system assisted display selection and expert system operator guidance. The first is intended to help the operator in his quest for information. The second attempts to guide the operator actions. The good and the bad points of each of these approaches is discussed

  20. Displaced midshaft fractures of the clavicle: non-operative treatment versus plate fixation (Sleutel-TRIAL. A multicentre randomised controlled trial

    Directory of Open Access Journals (Sweden)

    Vos Dagmar I

    2011-08-01

    Full Text Available Abstract Background The traditional view that the vast majority of midshaft clavicular fractures heal with good functional outcomes following non-operative treatment may be no longer valid for all midshaft clavicular fractures. Recent studies have presented a relatively high incidence of non-union and identified speciic limitations of the shoulder function in subgroups of patients with these injuries. Aim A prospective, multicentre randomised controlled trial (RCT will be conducted in 21 hospitals in the Netherlands, comparing fracture consolidation and shoulder function after either non-operative treatment with a sling or a plate fixation. Methods/design A total of 350 patients will be included, between 18 and 60 years of age, with a dislocated midshaft clavicular fracture. The primary outcome is the incidence of non-union, which will be determined with standardised X-rays (Antero-Posterior and 30 degrees caudocephalad view. Secondary outcome will be the functional outcome, measured using the Constant Score. Strength of the shoulder muscles will be measured with a handheld dynamometer (MicroFET2. Furthermore, the health-related Quality of Life score (ShortForm-36 and the Disabilities of Arm, Shoulder and Hand (DASH Outcome Measure will be monitored as subjective parameters. Data on complications, bone union, cosmetic aspects and use of painkillers will be collected with follow-up questionnaires. The follow-up time will be two years. All patients will be monitored at regular intervals over the subsequent twelve months (two and six weeks, three months and one year. After two years an interview by telephone and a written survey will be performed to evaluate the two-year functional and mechanical outcomes. All data will be analysed on an intention-to-treat basis, using univariate and multivariate analyses. Discussion This trial will provide level-1 evidence for the comparison of consolidation and functional outcome between two standardised

  1. Fluoride in drinking water and risk of hip fracture in the UK: a case-control study.

    Science.gov (United States)

    Hillier, S; Cooper, C; Kellingray, S; Russell, G; Hughes, H; Coggon, D

    2000-01-22

    Although the benefits of water fluoridation for dental health are widely accepted, concerns remain about possible adverse effects, particularly effects on bone. Several investigators have suggested increased rates of hip fracture in places with high concentrations of fluoride in drinking water, but this finding has not been consistent, possibly because of unrecognised confounding effects. We did a case-control study of men and women aged 50 years and older from the English county of Cleveland, and compared patients with hip fracture with community controls. Current addresses were ascertained for all participants; for those who agreed to an interview and who passed a mental test, more detailed information was obtained about lifetime residential history and exposure to other known and suspected risk factors for hip fracture. Exposures to fluoride in water were estimated from the residential histories and from information provided by water suppliers. Analysis was by logistic regression. 914 cases and 1196 controls were identified, of whom 514 and 527, respectively, were interviewed. Among those interviewed, hip fracture was strongly associated with low body-mass index (p for trend water ranged from 0.15 to 1.79 ppm. Current residence in Hartlepool was a good indicator for high lifetime exposure to fluoride. After adjustment for potential confounders, the odds ratio associated with an average lifetime exposure to fluoride > or =0.9 ppm was 1.0 [95% CI 0.7-1.5]. There is a low risk of hip fracture for people ingesting fluoride in drinking water at concentrations of about 1 ppm. This low risk should not be a reason for withholding fluoridation of water supplies.

  2. Control design profits heliostat techno-economics

    CSIR Research Space (South Africa)

    Rubin, N

    2012-05-01

    Full Text Available , and the economic impacts associated with reduced spillage at the receiver, that accrue through improved analysis, modelling and design techniques. 2. Background 2.1. Previous Results It is testimony to the robustness of feedback control that a stabilizing... Heliostat Techno-Economics Nick Rubin1, Thomas Roos2, Fintan Wilson2, Jason de Villiers2 and Strinivasan Perumal2 1 Systems Engineer ? CSIR, P O Box 395, Pretoria, 0001, South Africa, Phone: 0128413383, Fax:0128413179, NRubin@csir.co.za 2 THRoos...

  3. Fracture behaviour of teeth with conventional and mini-invasive access cavity designs

    Czech Academy of Sciences Publication Activity Database

    Chlup, Zdeněk; Žižka, R.; Kania, J.; Přibyl, M.

    2017-01-01

    Roč. 37, č. 14 (2017), s. 4423-4429 ISSN 0955-2219. [FAC 2016 - International Conference on Fractography of Advanced Ceramic s /5./. Smolenice, 09.10.2016-12.10.2016] R&D Projects: GA ČR GA14-11234S; GA MŠk(CZ) ED1.1.00/02.0068 Institutional support: RVO:68081723 Keywords : endodontically treated premolars * in-vitro * maxillary premolars * stress-distribution * cusp coverage * resistance * composite * resin * restorations * scaffolds * Fracture resistance * Cavity * Tooth * Compressive test * Fractography Subject RIV: JH - Ceramic s, Fire-Resistant Materials and Glass OBOR OECD: Ceramic s Impact factor: 3.411, year: 2016

  4. Fourier Transformed Infra-Red Imaging of Femoral Neck Bone: Reduced Heterogeneity of Mineral-to-Matrix and Carbonate-to-Phosphate and more Variable Crystallinity in Treatment-Naïve Fracture Cases compared to Fracture-Free Controls

    Science.gov (United States)

    Gourion-Arsiquaud, Samuel; Lukashova, Lyudmilla; Power, Jon; Loveridge, Nigel; Reeve, Jonathan; Boskey, Adele L.

    2012-01-01

    After age 60 hip fracture risk strongly increases, but only a fifth of this increase is attributable to reduced mineral density (BMD, measured clinically). Changes in bone quality, specifically bone composition as measured by Fourier Transform Infrared spectroscopic imaging (FTIRI), also contribute to fracture risk. Here, FTIRI was applied to study the femoral neck and provide spatially derived information on its mineral and matrix properties in age-matched fractured and non-fractured bones. Whole femoral neck cross sections, divided into quadrants along the neck’s axis, from 10 women with hip fracture and 10 cadaveric controls were studied using FTIRI and micro-computed Tomography. Although 3-dimensional micro-CT bone mineral densities were similar, the mineral-to-matrix ratio was reduced in the cases of hip fracture, confirming previous reports. New findings were that the FTIRI microscopic variation (heterogeneity) of the mineral-to-matrix ratio was substantially reduced in the fracture group as was the heterogeneity of the carbonate-to-phosphate ratio. Conversely, the heterogeneity of crystallinity was increased. Increased variation of crystallinity was statistically associated with reduced variation of the carbonate-to-phosphate ratio. Anatomical variation in these properties between the different femoral neck quadrants was reduced in the fracture group compared to controls. While our treatment-naïve patients had reduced rather than increased bending resistance, these changes in heterogeneity associated with hip fracture are in another way comparable to the effects of experimental bisphosphonate therapy, which decreases heterogeneity and other indicators of bone’s toughness as a material. PMID:22865771

  5. Designing a large scale combined pumping and tracer test in a fracture zone at Palmottu, Finland

    International Nuclear Information System (INIS)

    Gustafsson, E.; Nordqvist, R.; Korkealaakso, J.; Galarza, G.

    1997-01-01

    The Palmottu Natural Analogue Project in Finland continued as an EC-supported international analogue project in 1996, in order to study radionuclide migration in a natural uranium-rich environment. The site is located in an area of crystalline bedrock, characterized by granites and metamorphic rocks. The uranium deposit extends from the surface to a depth of more than 300 m, and have a thickness of up to 15 m. An overall aim of the project is to increase knowledge of factors affecting mobilization and retardation of uranium in crystalline bedrock. One of the important tasks within the project is to characterize the major flow paths for the groundwater, i.e. important hydraulic features, around the orebody. A planned experiment in one such feature, a sub-horizontal fracture zone which cross-cuts the uranium mineralization. The objectives of the planned combined pumping and tracer test is to verify and further up-date the present hydro-structural model around the central part of the mineralization, increase the current understanding about the hydraulic and solute transport properties of the sub-horizontal fracture zone, as well as to verify and further characterize its hydraulic boundaries. (author)

  6. New Design Concept for Universal CCD Controller

    Directory of Open Access Journals (Sweden)

    Wonyong Han

    1994-06-01

    Full Text Available Currently, the CCDs are widely used in astronomical observations either in direct imaging use or spectroscopic mode. However according to the recent technical advances, new large format CCDs are rapidly developed which have better performances with higher quantum efficiency and sensitivity. In many cases, some microprocessors have been adopted to deal with necessary digital logic for a CCD imaging system. This could often lack the flexibility of a system for a user to upgrade with new devices, especially of it is a commercial product. A new design concept has been explored which could provide the opportunity to deal with any format of devices from ant manufactures effectively for astronomical purposes. Recently available PLD (Programmable Logic Devices technology makes it possible to develop such digital circuit design, which can be integrated into a single component, instead of using microprocessors. The design concept could dramatically increase the efficiency and flexibility of a CCD imaging system, particularly when new or large format devices are available and to upgrade the performance of a system. Some variable system control parameters can be selected by a user with a wider range of choice. The software can support such functional requirements very conveniently. This approach can be applied not only to astronomical purpose, but also to some related fields, such as remote sensing and industrial applications.

  7. Successful emergency pain control for posterior rib fractures with ultrasound-guided erector spinae plane block.

    Science.gov (United States)

    Luftig, Josh; Mantuani, Daniel; Herring, Andrew A; Dixon, Brittany; Clattenburg, Eben; Nagdev, Arun

    2017-12-28

    The Eastern Association for the Surgery of Trauma and Trauma Anesthesiology Society Guidelines recommend prompt and effective multimodal analgesia for rib fractures that combines regional anesthesia (RA) techniques with pharmacotherapy to treat pain, optimize pulmonary function, and reduce opioid related complications. However, RA techniques such as epidurals and paravertebral blocks, are generally underutilized or unavailable for emergency department (ED) patients. The recently described serratus anterior plane block (SAPB) is a promising technique, but failures with posterior rib fractures have been observed. The erector spinae plane block (ESPB) is conceptually similar to the SAPB, but targets the posterior thorax making it likely more effective for ED patients with posterior rib fractures. Our initial experience demonstrates consistent success with the ESPB for traumatic posterior rib fracture analgesia. Herein, we present the first description of the ESPB utilized in the ED. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. Assessment of plastic flow and fracture properties with small specimens test techniques for IFMIF-designed specimens

    International Nuclear Information System (INIS)

    Spaetig, P.; Campitelli, E.N.; Bonade, R.; Baluc, N.

    2005-01-01

    The primary mission of the International Fusion Material Irradiation Facility (IFMIF) is to generate a material database to be used for the design of various components, for the licensing and for the assessment of the safe operation of a demonstration fusion reactor. IFMIF is an accelerator-based high-energy neutron source whose irradiation volume is quite limited (0.5 l for the high fluence volume). This requires the use of small specimens to measure the irradiation-induced changes on the physical and mechanical properties of materials. In this paper, we developed finite element models to better analyze the results obtained with two different small specimen test techniques applied to the tempered martensitic steel F82H-mod. First, one model was used to reconstruct the load-deflection curves of small ball punch tests, which are usually used to extract standard tensile parameters. It was shown that a reasonable assessment of the overall plastic flow can be done with small ball punch tests. Second, we investigated the stress field sensitivity at a crack tip to the constitutive behavior, for a crack modeled in plane strain, small-scale yielding and fracture mode I conditions. Based upon a local criterion for cleavage, that appears to be the basis to account for the size and geometry effects on fracture toughness, we showed that the details of the constitutive properties play a key role in modeling the irradiation-induced fracture toughness changes. Consequently, we suggest that much more attention and efforts have to be paid in investigating the post-yield behavior of the irradiated specimens and, in order to reach this goal, we recommend the use of not only tensile specimens but also that of compression ones in the IFMIF irradiation matrices. (author)

  9. Risk factors and epidemiological profile of hip fractures in Indian population: A case-control study

    Directory of Open Access Journals (Sweden)

    Kaustubh Ahuja

    2017-09-01

    Conclusions: Hip fractures in the elderly population are on a rising trend especially in the Indian subcontinent due to a number of factors both hereditary and acquired. Simple measures like routine usage of bedside railing, wall-side railings at an appropriate height, high friction tiles inside rooms and washrooms, and adequate lighting indoors can play a significant role in reducing falls and hip fractures among the elderly.

  10. Odds ratios for hip- and lower forearm fracture using peripheral bone densitometry; a case-control study of postmenopausal women

    DEFF Research Database (Denmark)

    Saleh, M M A; Jørgensen, H L; Lauritzen, J B

    2002-01-01

    concern when using peripheral densitometry is the poor correlation with the central measurements. The main aim of this study is, therefore, to assess the possibility of expressing ultrasound measurements at the heel and bone mineral density (BMD) measured at the distal forearm as fracture odds ratios...... rather than an absolute measure of bone mass. METHODS: A total of 76 women with lower forearm fracture, 47 women with hip fracture and 231 age-matched women (controls) were included. All had broadband ultrasound attenuation (BUA) and speed of sound (SOS) measured at the heel using the DTU-one ultrasound.......8; 5.2) for heel-BUA (T-score cutoff: -2.3), 4.1 (2.3; 7.4) for heel-SOS (-2.1) and 2.2 (1.3; 3.7) for lower forearm BMD (-2.7). The odds ratio for hip fracture was 3.4 (1.5-7.7) for heel-BUA (-2.7), 3.6 (1.6; 8.1) for heel-SOS (-2.6) and 3.2 (1.4; 7.4) for lower forearm BMD (-2.9). CONCLUSION...

  11. Fundamental differences in axial and appendicular bone density in stress fractured and uninjured Royal Marine recruits--a matched case-control study.

    Science.gov (United States)

    Davey, Trish; Lanham-New, Susan A; Shaw, Anneliese M; Cobley, Rosalyn; Allsopp, Adrian J; Hajjawi, Mark O R; Arnett, Timothy R; Taylor, Pat; Cooper, Cyrus; Fallowfield, Joanne L

    2015-04-01

    Stress fracture is a common overuse injury within military training, resulting in significant economic losses to the military worldwide. Studies to date have failed to fully identify the bone density and bone structural differences between stress fractured personnel and controls due to inadequate adjustment for key confounding factors; namely age, body size and physical fitness; and poor sample size. The aim of this study was to investigate bone differences between male Royal Marine recruits who suffered a stress fracture during the 32 weeks of training and uninjured control recruits, matched for age, body weight, height and aerobic fitness. A total of 1090 recruits were followed through training and 78 recruits suffered at least one stress fracture. Bone mineral density (BMD) was measured at the lumbar spine (LS), femoral neck (FN) and whole body (WB) using Dual X-ray Absorptiometry in 62 matched pairs; tibial bone parameters were measured using peripheral Quantitative Computer Tomography in 51 matched pairs. Serum C-terminal peptide concentration was measured as a marker of bone resorption at baseline, week-15 and week-32. ANCOVA was used to determine differences between stress fractured recruits and controls. BMD at the LS, WB and FN sites was consistently lower in the stress fracture group (Pstress fracture recruits and controls were evident in all slices of the tibia, with the most prominent differences seen at the 38% tibial slice. There was a negative correlation between the bone cross-sectional area and BMD at the 38% tibial slice. There was no difference in serum CTx concentration between stress fracture recruits and matched controls at any stage of training. These results show evidence of fundamental differences in bone mass and structure in stress fracture recruits, and provide useful data on bone risk factor profiles for stress fracture within a healthy military population. Crown Copyright © 2014. Published by Elsevier Inc. All rights reserved.

  12. Back to the future – feasibility of recruitment and retention to patient education and telephone follow-up after hip fracture: a pilot randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Langford DP

    2015-09-01

    Full Text Available Dolores P Langford,1,2 Lena Fleig,3–5 Kristin C Brown,3,4 Nancy J Cho,1,2 Maeve Frost,1 Monique Ledoyen,1 Jayne Lehn,1 Kostas Panagiotopoulos,1,6 Nina Sharpe,1 Maureen C Ashe3,4 1Vancouver Coastal Health, 2Department of Physical Therapy, The University of British Columbia (UBC, 3Department of Family Practice, The University of British Columbia (UBC, 4Centre for Hip Health and Mobility, Vancouver, BC, Canada; 5Freie Universität Berlin, Health Psychology, Berlin, Germany; 6Department of Orthopaedics, The University of British Columbia (UBC, Vancouver, BC, Canada Objectives: Our primary aim of this pilot study was to test feasibility of the planned design, the interventions (education plus telephone coaching, and the outcome measures, and to facilitate a power calculation for a future randomized controlled trial to improve adherence to recovery goals following hip fracture.Design: This is a parallel 1:1 randomized controlled feasibility study.Setting: The study was conducted in a teaching hospital in Vancouver, BC, Canada.Participants: Participants were community-dwelling adults over 60 years of age with a recent hip fracture. They were recruited and assessed in hospital, and then randomized after hospital discharge to the intervention or control group by a web-based randomization service. Treatment allocation was concealed to the investigators, measurement team, and data entry assistants and analysts. Participants and the research physiotherapist were aware of treatment allocation.Intervention: Intervention included usual care for hip fracture plus a 1-hour in-hospital educational session using a patient-centered educational manual and four videos, and up to five postdischarge telephone calls from a physiotherapist to provide recovery coaching. The control group received usual care plus a 1-hour in-hospital educational session using the educational manual and videos.Measurement: Our primary outcome was feasibility, specifically recruitment

  13. [Application of the anatomic plate and trapezoid plate in comminuted intertrochanteric fracture combined with trochanteric coronal position fracture: a controlled clinical trial].

    Science.gov (United States)

    Zhen, Ping; Liu, Xing-Yan; Gao, Ming-Xuan; Tian, Qi

    2010-05-01

    To investigate the therapeutic effect and operative characteristic of the anatomic plate and trapezoid plate for treament of the comminuted intertrochanteric fracture combined with trochanteric coronal position fracture. From Jan. 1998 to Mar. 2007, 57 patients suffered from comminuted intertrochanteric fracture combined with trochanteric coronal position fracture were randomly divided into two groups, 21 patients in trapezoid plate group were treated with the trapezoid compression plate, included 11 males and 10 females with an average age of 41.8 years; and 36 patients in anatomic plate group were treated with the anatomic plate, included 17 males and 19 females with an average age of 42.1 years. All of the 57 fractures were A3 type according to AO classification. The functions of hip joints were evaluated according to the Harris hip functional standard score. All 57 patients were followed-up for 5 months to 9 years and 3 months with an average of 4.8 years. The healing time of the fractures was from 8 to 20 weeks with an average of 12.8 weeks. The results of Harris scoring showed the pain scores of the anatomic plate group were higher than that of the trapezoid plate group (P 0.05). In unstable comminuted intertrochanteric fracture combined with trochanteric coronal position fracture, the lateral wall of trochanteric is often destroyed. The anatomic plate and the trapeziod compression plate can provide effective internal fixation, while many othere internal fixation methods were limited in this kind of fracture. As compared with the anatomic plate fixation, the trapezoid compression plate fixation of comminuted intertrochanteric fracture combined with trochanteric coronal position fracture have several advantages, such as fewer complications, faster union of fracture and earlier recovery of joint functions.

  14. Systems approach for design control at Monitored Retrievable Storage Project

    International Nuclear Information System (INIS)

    Kumar, P.N.; Williams, J.R.

    1994-01-01

    This paper describes the systems approach in establishing design control for the Monitored Retrievable Storage Project design development. Key elements in design control are enumerated and systems engineering aspects are detailed. Application of lessons learned from the Yucca Mountain Project experience is addressed. An integrated approach combining quality assurance and systems engineering requirements is suggested to practice effective design control

  15. Introduction to multicopter design and control

    CERN Document Server

    Quan, Quan

    2017-01-01

    This book is the first textbook specially on multicopter systems in the world. It provides a comprehensive overview of multicopter systems, rather than focusing on a single method or technique. The fifteen chapters are divided into five parts, covering the topics of multicopter design, modeling, state estimation, control, and decision-making. It differs from other books in the field in three major respects: it is basic and practical, offering self-contained content and presenting hands-on methods; it is comprehensive and systematic; and it is timely. It is also closely related to the autopilot that users often employ today and provides insights into the code employed. As such, it offers a valuable resource for anyone interested in multicopters, including students, teachers, researchers, and engineers.

  16. Hydrogen fracture toughness tester completion

    Energy Technology Data Exchange (ETDEWEB)

    Morgan, Michael J. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2015-09-30

    The Hydrogen Fracture Toughness Tester (HFTT) is a mechanical testing machine designed for conducting fracture mechanics tests on materials in high-pressure hydrogen gas. The tester is needed for evaluating the effects of hydrogen on the cracking properties of tritium reservoir materials. It consists of an Instron Model 8862 Electromechanical Test Frame; an Autoclave Engineering Pressure Vessel, an Electric Potential Drop Crack Length Measurement System, associated computer control and data acquisition systems, and a high-pressure hydrogen gas manifold and handling system.

  17. Fourier transform infrared imaging of femoral neck bone: reduced heterogeneity of mineral-to-matrix and carbonate-to-phosphate and more variable crystallinity in treatment-naive fracture cases compared with fracture-free controls.

    Science.gov (United States)

    Gourion-Arsiquaud, Samuel; Lukashova, Lyudmilla; Power, Jon; Loveridge, Nigel; Reeve, Jonathan; Boskey, Adele L

    2013-01-01

    After the age of 60 years, hip fracture risk strongly increases, but only a fifth of this increase is attributable to reduced bone mineral density (BMD, measured clinically). Changes in bone quality, specifically bone composition as measured by Fourier transform infrared spectroscopic imaging (FTIRI), also contribute to fracture risk. Here, FTIRI was applied to study the femoral neck and provide spatially derived information on its mineral and matrix properties in age-matched fractured and nonfractured bones. Whole femoral neck cross sections, divided into quadrants along the neck's axis, from 10 women with hip fracture and 10 cadaveric controls were studied using FTIRI and micro-computed tomography. Although 3-dimensional micro-CT bone mineral densities were similar, the mineral-to-matrix ratio was reduced in the cases of hip fracture, confirming previous reports. New findings were that the FTIRI microscopic variation (heterogeneity) of the mineral-to-matrix ratio was substantially reduced in the fracture group as was the heterogeneity of the carbonate-to-phosphate ratio. Conversely, the heterogeneity of crystallinity was increased. Increased variation of crystallinity was statistically associated with reduced variation of the carbonate-to-phosphate ratio. Anatomical variation in these properties between the different femoral neck quadrants was reduced in the fracture group compared with controls. Although our treatment-naive patients had reduced rather than increased bending resistance, these changes in heterogeneity associated with hip fracture are in another way comparable to the effects of experimental bisphosphonate therapy, which decreases heterogeneity and other indicators of bone's toughness as a material. Copyright © 2013 American Society for Bone and Mineral Research.

  18. Microseismic Monitoring of Stimulating Shale Gas Reservoir in SW China: 2. Spatial Clustering Controlled by the Preexisting Faults and Fractures

    Science.gov (United States)

    Chen, Haichao; Meng, Xiaobo; Niu, Fenglin; Tang, Youcai; Yin, Chen; Wu, Furong

    2018-02-01

    Microseismic monitoring is crucial to improving stimulation efficiency of hydraulic fracturing treatment, as well as to mitigating potential induced seismic hazard. We applied an improved matching and locating technique to the downhole microseismic data set during one treatment stage along a horizontal well within the Weiyuan shale gas play inside Sichuan Basin in SW China, resulting in 3,052 well-located microseismic events. We employed this expanded catalog to investigate the spatiotemporal evolution of the microseismicity in order to constrain migration of the injected fluids and the associated dynamic processes. The microseismicity is generally characterized by two distinctly different clusters, both of which are highly correlated with the injection activity spatially and temporarily. The distant and well-confined cluster (cluster A) is featured by relatively large-magnitude events, with 40 events of M -1 or greater, whereas the cluster in the immediate vicinity of the wellbore (cluster B) includes two apparent lineations of seismicity with a NE-SW trending, consistent with the predominant orientation of natural fractures. We calculated the b-value and D-value, an index of fracture complexity, and found significant differences between the two seismicity clusters. Particularly, the distant cluster showed an extremely low b-value ( 0.47) and D-value ( 1.35). We speculate that the distant cluster is triggered by reactivation of a preexisting critically stressed fault, whereas the two lineations are induced by shear failures of optimally oriented natural fractures associated with fluid diffusion. In both cases, the spatially clustered microseismicity related to hydraulic stimulation is strongly controlled by the preexisting faults and fractures.

  19. Characteristics of the Foot Static Alignment and the Plantar Pressure Associated with Fifth Metatarsal Stress Fracture History in Male Soccer Players: a Case-Control Study.

    Science.gov (United States)

    Matsuda, Sho; Fukubayashi, Toru; Hirose, Norikazu

    2017-12-01

    There is a large amount of information regarding risk factors for fifth metatarsal stress fractures; however, there are few studies involving large numbers of subjects. This study aimed to compare the static foot alignment and distribution of foot pressure of athletes with and without a history of fifth metatarsal stress fractures. The study participants comprised 335 collegiate male soccer players. Twenty-nine with a history of fifth metatarsal stress fractures were in the fracture group and 306 were in the control group (with subgroups as follows: 30 in the fracture foot group and 28 in the non-fracture group). We measured the foot length, arch height, weight-bearing leg-heel alignment, non-weight-bearing leg-heel alignment, forefoot angle relative to the rearfoot, forefoot angle relative to the horizontal axis, and foot pressure. The non-weight-bearing leg-heel alignment was significantly smaller and the forefoot angle relative to the rearfoot was significantly greater in the fracture foot group than in the control foot group (P = 0.049 and P = 0.038, respectively). With regard to plantar pressure, there were no significant differences among the groups. Midfield players had significantly higher rates of fifth metatarsal stress fracture in their histories, whereas defenders had significantly lower rates (chi-square = 13.2, P stress fractures according to the type of foot (kicking foot vs. pivoting foot) or the severity of ankle sprain. Playing the midfield position and having an everted rearfoot and inverted forefoot alignment were associated with fifth metatarsal stress fractures. This information may be helpful for preventing fifth metatarsal stress fracture recurrence. More detailed load evaluations and a prospective study are needed in the future.

  20. Exercise and fractures in postmenopausal women. Final results of the controlled Erlangen Fitness and Osteoporosis Prevention Study (EFOPS).

    Science.gov (United States)

    Kemmler, W; Bebenek, M; Kohl, M; von Stengel, S

    2015-10-01

    The EFOPS trial clearly established the positive effect of long-term exercise on clinical low-trauma fractures in postmenopausal women at risk. Bearing in mind that the complex anti-fracture exercise protocols also affect a large variety of diseases of increased age, we strongly encourage older adults to perform multipurpose exercise programs. Physical exercise may be an efficient option for autonomous fracture prevention during increasing age. The aim of the study was to evaluate the effect of exercise on clinical overall fracture incidence and bone mineral density (BMD) in elderly subjects at risk. In 1998 initially, 137 early-postmenopausal, osteopenic women living in Erlangen-Nuremberg, Germany, were included in the EFOPS trial. Subjects of the exercise group (EG; n = 86) conducted two supervised group and two home exercise sessions/week while the control group (CG; n = 51) was requested to maintain their physical activity. Primary study endpoints were clinical overall low-trauma fractures determined by questionnaires, structured interviews, and BMD at the lumbar spine and femoral neck assessed by dual-energy X-ray absorptiometry. In 2014, 105 subjects (EG: n = 59 vs. CG: n = 46) representing 1680 participant-years were included in the 16-year follow-up analysis. Risk ratio in the EG for overall low-trauma fractures was 0.51 (95% confidence interval (95% CI) 0.23 to 0.97, p = .046), rate ratio was 0.42 (95% CI 0.20 to 0.86, p = .018). Based on comparable baseline values, lumbar spine (MV -1.5%, 95% CI -0.1 to -2.8 vs. -5.8%, -3.3 to -7.2%) and femoral neck (-6.5%, -5.2 to -7.7 vs. -9.6%, -8.2 to 11.1%) BMD decreased in both groups; however, the reduction was more pronounced in the CG (p ≤ .001). This study clearly evidenced the high anti-fracture efficiency of multipurpose exercise programs. Considering furthermore the favorable effect of exercise on most other risk factors of increasing age, we strongly encourage older adults to perform multipurpose

  1. Innovative Methodology for Detection of Fracture-Controlled Sweet Spots in the Northern Appalachian Basin

    Energy Technology Data Exchange (ETDEWEB)

    Robert Jacobi; John Fountain; Stuart Loewenstein; Edward DeRidder; Bruce Hart

    2007-03-31

    rift faults have been episodically reactivated, and a few of these faults extend through the entire stratigraphic section. The ENE-trending faults and N-striking transfer zones controlled the development of the T/BR grabens. In both the Seneca Lake and Cayuga Lake regions, we found more FIDs than Landsat lineaments, both in terms of individual FIDs and trends of FIDs. Our fused Landsat/ASTER image provided more lineaments, but the structural framework inferred from these lineaments is incomplete even for the fused image. Individual lineaments may not predict surface FIDs (within 500m). However, an individual lineament that has been groundtruthed by outcrop FIDs can be used as a proxy for the trend of intense fracturing. Aeromagnetics and seismic reflection data across the discovery fields west of Keuka Lake demonstrate that the fields terminate on the east against northerly-striking faults that extend from Precambrian basement to, in some cases, the surface; the fields terminate in the west at N- and NW-striking faults. Seismic and well log data show that the fields must be compartmentalized, since different parts of the same field show different histories of development. T/BR fields south of the research area also terminate (on the east) against northerly-trending lineaments which we suggest mark faults. Phase II, completed in 2006, consisted of collection and analysis of an oriented, horizontal core retrieved from one of the T/BR fields in a graben south of the field area. The field is located along ENE-trending EarthSat (1997) lineaments, similar to that hypothesized for the study area. The horizontal core shows much evidence for reactivation along the ENE-trending faults, with multiple events of vein development and both horizontal and vertical stylolite growth. Horizontal veins that post- and pre-date other vein sets indicate that at least two orogenic phases (separated by unloading) affected vein development. Many of the veins and releasing bend features

  2. In vivo biomechanical evaluation of a novel angle-stable interlocking nail design in a canine tibial fracture model.

    Science.gov (United States)

    Déjardin, Loïc M; Cabassu, Julien B; Guillou, Reunan P; Villwock, Mark; Guiot, Laurent P; Haut, Roger C

    2014-03-01

    To compare clinical outcome and callus biomechanical properties of a novel angle stable interlocking nail (AS-ILN) and a 6 mm bolted standard ILN (ILN6b) in a canine tibial fracture model. Experimental in vivo study. Purpose-bred hounds (n = 11). A 5 mm mid-diaphyseal tibial ostectomy was stabilized with an AS-ILN (n = 6) or an ILN6b (n = 5). Orthopedic examinations and radiographs were performed every other week until clinical union (18 weeks). Paired tibiae were tested in torsion until failure. Callus torsional strength and toughness were statistically compared and failure mode described. Total and cortical callus volumes were computed and statistically compared from CT slices of the original ostectomy gap. Statistical significance was set at P dogs (P dogs by 10 weeks and in 3/5 ILN6b dogs at 18 weeks. Callus mechanical properties were significantly greater in AS-ILN than ILN6b specimens by 77% (failure torque) and 166% (toughness). Failure occurred by acute spiral (control and AS-ILN) or progressive transverse fractures (ILN6b). Cortical callus volume was 111% greater in AS-ILN than ILN6b specimens (P < .05). Earlier functional recovery, callus strength and remodeling suggest that the AS-ILN provides a postoperative biomechanical environment more conducive to bone healing than a comparable standard ILN. © Copyright 2014 by The American College of Veterinary Surgeons.

  3. Development of carbon/carbon composite control rod for HTTR. 1. Preparation of elements and their fracture tests

    International Nuclear Information System (INIS)

    Eto, Motokuni; Ishiyama, Shintaro; Ugachi, Hirokazu

    1996-08-01

    For the High Temperature Engineering Test Reactor(HTTR) the control rod sleeve is made of Alloy 800H for which a particular process is imposed when the reactor needs to be scrammed. The less restricted operation of the reactor would be attained if there would be the control rod more resistant to high temperature and neutron irradiation. This report summarizes the results which have been obtained as of March 1996 in the course of the development of the C/C composite control rod. Materials used were pitch- or PAN-based fiber-reinforced 2-dimensional carbon composites, from which preforms of the elements of a control rod were fabricated. The preforms were carbonized at 1000degC after being impregnated with pitch. Then they were graphitized at 3000degC, followed by a purification treatment with halogen. The elements included the pellet holder, lace truck and pin. The pin was fabricated by the fiber laminating technique. A control rod is to consist of pellet holders which are connected by the lace trucks with pins. Various strength tests were carried out on these elements. An irradiation of the elements made of PAN-based material was performed in JRR-3 at 900±50degC to a neutron fluence of 1x10 25 n/m 2 (E>29fJ). As for the strength tests on the elements, there were some differences between PAN- and pitch-based composites: In general, elements made of PAN-based composite showed the more plastic behavior before they fractured, whereas those of pitch-based material behaved in the more brittle manner. Fracture tests of the irradiated elements showed that fracture load and fracture displacement enough for assuring the integrity of the control rod structure were maintained even after the irradiation. It was also found that if the applied load was parallel to the fiber felt plane both fracture load and strain increased, whereas the load increase and strain decrease were observed for the applied load against the plane. (J.P.N.)

  4. Development of carbon/carbon composite control rod for HTTR. 1. Preparation of elements and their fracture tests

    Energy Technology Data Exchange (ETDEWEB)

    Eto, Motokuni; Ishiyama, Shintaro; Ugachi, Hirokazu [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1996-08-01

    For the High Temperature Engineering Test Reactor(HTTR) the control rod sleeve is made of Alloy 800H for which a particular process is imposed when the reactor needs to be scrammed. The less restricted operation of the reactor would be attained if there would be the control rod more resistant to high temperature and neutron irradiation. This report summarizes the results which have been obtained as of March 1996 in the course of the development of the C/C composite control rod. Materials used were pitch- or PAN-based fiber-reinforced 2-dimensional carbon composites, from which preforms of the elements of a control rod were fabricated. The preforms were carbonized at 1000degC after being impregnated with pitch. Then they were graphitized at 3000degC, followed by a purification treatment with halogen. The elements included the pellet holder, lace truck and pin. The pin was fabricated by the fiber laminating technique. A control rod is to consist of pellet holders which are connected by the lace trucks with pins. Various strength tests were carried out on these elements. An irradiation of the elements made of PAN-based material was performed in JRR-3 at 900{+-}50degC to a neutron fluence of 1x10{sup 25} n/m{sup 2} (E>29fJ). As for the strength tests on the elements, there were some differences between PAN- and pitch-based composites: In general, elements made of PAN-based composite showed the more plastic behavior before they fractured, whereas those of pitch-based material behaved in the more brittle manner. Fracture tests of the irradiated elements showed that fracture load and fracture displacement enough for assuring the integrity of the control rod structure were maintained even after the irradiation. It was also found that if the applied load was parallel to the fiber felt plane both fracture load and strain increased, whereas the load increase and strain decrease were observed for the applied load against the plane. (J.P.N.)

  5. Analysis and design of networked control systems

    CERN Document Server

    You, Keyou; Xie, Lihua

    2015-01-01

    This monograph focuses on characterizing the stability and performance consequences of inserting limited-capacity communication networks within a control loop. The text shows how integration of the ideas of control and estimation with those of communication and information theory can be used to provide important insights concerning several fundamental problems such as: ·         minimum data rate for stabilization of linear systems over noisy channels; ·         minimum network requirement for stabilization of linear systems over fading channels; and ·         stability of Kalman filtering with intermittent observations. A fundamental link is revealed between the topological entropy of linear dynamical systems and the capacities of communication channels. The design of a logarithmic quantizer for the stabilization of linear systems under various network environments is also extensively discussed and solutions to many problems of Kalman filtering with intermittent observations are de...

  6. The design of traffic signal coordinated control

    Science.gov (United States)

    Guo, Xueting; Sun, Hongsheng; Wang, Xifu

    2017-05-01

    Traffic as the tertiary industry is an important pillar industry to support the normal development of the economy. But now China's road traffic development and economic development has shown a great imbalance and fault phenomenon, which greatly inhibited the normal development of China's economy. Now in many large and medium-sized cities in China are implementing green belt construction. The so-called green band is when the road conditions to meet the conditions for the establishment of the green band, the sections of the intersection of several planning to a traffic coordination control system, so that when the driver at a specific speed can be achieved without stopping the continuous Through the intersection. Green belt can effectively reduce the delay and queuing length of vehicle driving, the normal function of urban roads and reduce the economic losses caused by traffic congestion is a great help. In this paper, the theoretical basis of the design of the coordinated control system is described. Secondly, the green time offset is calculated by the analytic method and the green band is established. And then the VISSIM software is used to simulate the traffic system before and after the improvement. Finally, the results of the two simulations are compared.

  7. Directional semivariogram analysis to identify and rank controls on the spatial variability of fracture networks

    Science.gov (United States)

    Hanke, John R.; Fischer, Mark P.; Pollyea, Ryan M.

    2018-03-01

    In this study, the directional semivariogram is deployed to investigate the spatial variability of map-scale fracture network attributes in the Paradox Basin, Utah. The relative variability ratio (R) is introduced as the ratio of integrated anisotropic semivariogram models, and R is shown to be an effective metric for quantifying the magnitude of spatial variability for any two azimuthal directions. R is applied to a GIS-based data set comprising roughly 1200 fractures, in an area which is bounded by a map-scale anticline and a km-scale normal fault. This analysis reveals that proximity to the fault strongly influences the magnitude of spatial variability for both fracture intensity and intersection density within 1-2 km. Additionally, there is significant anisotropy in the spatial variability, which is correlated with trends of the anticline and fault. The direction of minimum spatial correlation is normal to the fault at proximal distances, and gradually rotates and becomes subparallel to the fold axis over the same 1-2 km distance away from the fault. We interpret these changes to reflect varying scales of influence of the fault and the fold on fracture network development: the fault locally influences the magnitude and variability of fracture network attributes, whereas the fold sets the background level and structure of directional variability.

  8. Does self-efficacy mediate functional change in older adults participating in an exercise program after hip fracture? A randomized control trial

    Science.gov (United States)

    Latham, Nancy K.; Ni, Pengsheng; Jette, Alan M.

    2015-01-01

    Objectives This study examined whether self-efficacy mediated the effect of the HIP Rehab exercise program on activity limitations in older adults after hip fracture, and whether the mediation effect was different between different gender and age groups. Design Randomized controlled trial (RCT) Setting Community Participants Two hundred and thirty two participants aged 79±9.4 years with hip fracture were randomly assigned to intervention (n=120) or attention control (n=112) groups. Interventions The 6-month intervention, the HIP Rehab, is a functionally-oriented, home-based exercise program. Data was collected at baseline, post-intervention (6 months), and follow-up (9 months). Main outcome measure Activity Measure for Post-Acute Care (AM-PAC) Results The mediation effect of the HIP Rehab exercise program on Basic Mobility function through self-efficacy for exercise was significant at 9 months (βindirect=0.21). Similarly, the mediation effect of the intervention on Daily Activity function through self-efficacy for exercise was significant at 9 months (βindirect=0.49). In subgroup analyses, the mediation effect was significant at 9 months in the younger group (≤79 years old) in comparison to the older group, and was significant in females in comparison to males. Conclusion Self-efficacy may play a partial mediating role for the effect on some longer-term functional outcomes in the HIP Rehab intervention. The results suggest that program components that target self-efficacy should be incorporated in the future hip fracture rehabilitation interventions. Age and gender of the targeted participants may also need to be considered when developing interventions. PMID:25701101

  9. Effect of mix design on the size-independent fracture energy of normal- and high-strength self-compacting concrete

    Directory of Open Access Journals (Sweden)

    H. Cifuentes

    2018-02-01

    Full Text Available Self-compacting concrete has a characteristic microstructure inherent to its specific composition. The higher content of fine particles in self-compacting concrete relative to the equivalent vibrated concrete produces a different fracture behavior that affects the main fracture parameters. In this work, a comprehensive experimental investigation of the fracture behavior of self-compacting concrete has been carried out. Twelve different self-compacting concrete mixes with compressive strength ranging from 39 to 124 MPa (wider range than in other studies have been subjected to three-point bending tests in order to determine the specific fracture energy. The influence of the mix design and its composition (coarse aggregate fraction, the water to binder ratio and the paste to solids ratio on its fracture behavior has been analyzed. Moreover, further evidence of the objectivity of the size-independent fracture energy results, obtained by the two most commonly used methods, has been provided on the self-compacting concrete mixes.

  10. [The randomized controlled trial of the treatment for clavicular fracture by rotatory manual reduction with forceps holder and retrograde percutaneous pinning transfixation].

    Science.gov (United States)

    Bi, Hong-zheng; Yang, Mao-qing; Tan, Yuan-chao; Fu, Song

    2008-07-01

    To study the curative effect and safety of rotatory manual reduction with forceps holder and retrograde percutaneous pinning transfixation in treating clavicular fracture. All 201 cases of clavicular fractures were randomly divided into treatment group (101 cases) and control group (100 cases). The treatment group was treated by rotatory manual reduction with forceps holder and retrograde percutaneous pinning transfixation. The control group was treated by open reduction and internal fixation with Kirschner pin. All cases were followed up for 4 to 21 months (mean 10.6 months). SPSS was used to analyze clinic healing time of fracture and shoulder-joint function in both two groups. After operation, 101 cases of treatment group achieved union of fracture and the clinical healing time was 28 to 49 days (mean 34.5+/-2.7 days). In control group,there were 4 cases with nonunion of fracture,the other 96 cases were union,the clinical healing time was 36 to 92 days (mean 55.3+/-4.8 days). The excellent and good rate of shoulder-joint function was 100% in treatment group and 83% in control group. By t-test and chi2-test, there was significant difference between the two groups in curative effect (Pmanual reduction with forceps holder and retrograde pinning transfixation can be used in various kinds of clavicular shaft fracture, with many virtues such as easy operation, reliable fixation, short union time of fracture, good functional recovery of shoulder-joint and no incision scar affecting appearance.

  11. Locking plate versus external fixation for type C distal radius fractures: A meta-analysis of randomized controlled trials

    Directory of Open Access Journals (Sweden)

    Dong Wang

    2018-04-01

    Full Text Available Purpose: Distal radial fracture is one of the most common fractures. Up to now, locking plates (LP and external fixation (EF are two conventional surgical approaches to type C radius fracture. Which method is superior has not yet reached a consensus. We try to assess the clinical effectiveness of the two interventions by this meta-analysis. Methods: We used network to search the PubMed, Embase, and Cochrane Medical Library of randomized controlled clinical trials about the type C distal radius fractures performed according to the search strategy mentioned in Cochrane Handbook 5.1.0 from Jan. 2005 to Jan. 2016. Patients in the experimental group were used LP, in the control group were included EF and other surgical approaches. Publication language was restricted to English. Studies that patient population and surgical indication did not define had been excluded. Studies must report at least one of the outcomes as follow: radial inclination, palmar tilt, ulnar variance, range of wrist flexion and extension, and range of wrist supination and pronation. The trials in which participants included children were excluded. We used Jadad study scores to appraise the study. Results: Seven studies included 162 patients (LP group and 190 patients (EF group. We compared the radial inclination, palmar tilt, ulnar variance, range of wrist flexion and extension, and range of wrist supination and pronation. The radial inclination were revealed a difference favoring LP over EF [WMD = 1.84, 95% CI (0.17, 3.50, p = 0.03] and the palmar tilt and ulnar variance was no significant difference between the two groups [(WMD = 3.61, 95% CI (0.00, 7.23, p = 0.05; WMD = 0.05, 95% CI (−0.99, 1.09, p = 0.93]. The functional activities of range of flexion and extension and range of supination and pronation between the two groups was no difference [WMD = 10.04, 95% CI (−6.88, 26.96, p = 0.24; WMD = 12.53, 95% CI (−9.99, 35.06, p = 0.28]. Conclusion

  12. H-Infinity Control Design Considering Packet Loss as a Disturbance for Networked Control Systems

    OpenAIRE

    OGURA, Takashi; KOBAYASHI, Kentaro; OKADA, Hiraku; KATAYAMA, Masaaki

    2017-01-01

    This paper studies H∞ control for networked control systems with packet loss. In networked control systems, packet loss is one of major weakness because the control performance deteriorates due to packet loss. H∞ control, which is one of robust control, can design a controller to reduce the influence of disturbances acting on the controlled object. This paper proposes an H∞ control design that considers packet loss as a disturbance. Numerical examples show that the proposed H∞ control design ...

  13. Modelling of Local Necking and Fracture in Aluminium Alloys

    International Nuclear Information System (INIS)

    Achani, D.; Eriksson, M.; Hopperstad, O. S.; Lademo, O.-G.

    2007-01-01

    Non-linear Finite Element simulations are extensively used in forming and crashworthiness studies of automotive components and structures in which fracture need to be controlled. For thin-walled ductile materials, the fracture-related phenomena that must be properly represented are thinning instability, ductile fracture and through-thickness shear instability. Proper representation of the fracture process relies on the accuracy of constitutive and fracture models and their parameters that need to be calibrated through well defined experiments. The present study focuses on local necking and fracture which is of high industrial importance, and uses a phenomenological criterion for modelling fracture in aluminium alloys. As an accurate description of plastic anisotropy is important, advanced phenomenological constitutive equations based on the yield criterion YLD2000/YLD2003 are used. Uniaxial tensile tests and disc compression tests are performed for identification of the constitutive model parameters. Ductile fracture is described by the Cockcroft-Latham fracture criterion and an in-plane shear tests is performed to identify the fracture parameter. The reason is that in a well designed in-plane shear test no thinning instability should occur and it thus gives more direct information about the phenomenon of ductile fracture. Numerical simulations have been performed using a user-defined material model implemented in the general-purpose non-linear FE code LS-DYNA. The applicability of the model is demonstrated by correlating the predicted and experimental response in the in-plane shear tests and additional plane strain tension tests

  14. Tai Chi for osteopenic women: design and rationale of a pragmatic randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Fischer Mary

    2010-03-01

    Full Text Available Abstract Background Post-menopausal osteopenic women are at increased risk for skeletal fractures. Current osteopenia treatment guidelines include exercise, however, optimal exercise regimens for attenuating bone mineral density (BMD loss, or for addressing other fracture-related risk factors (e.g. poor balance, decreased muscle strength are not well-defined. Tai Chi is an increasingly popular weight bearing mind-body exercise that has been reported to positively impact BMD dynamics and improve postural control, however, current evidence is inconclusive. This study will determine the effectiveness of Tai Chi in reducing rates of bone turnover in post-menopausal osteopenic women, compared with standard care, and will preliminarily explore biomechanical processes that might inform how Tai Chi impacts BMD and associated fracture risks. Methods/Design A total of 86 post-menopausal women, aged 45-70y, T-score of the hip and/or spine -1.0 and -2.5, have been recruited from primary care clinics of a large healthcare system based in Boston. They have been randomized to a group-based 9-month Tai Chi program plus standard care or to standard care only. A unique aspect of this trial is its pragmatic design, which allows participants randomized to Tai Chi to choose from a pre-screened list of community-based Tai Chi programs. Interviewers masked to participants' treatment group assess outcomes at baseline and 3 and 9 months after randomization. Primary outcomes are serum markers of bone resorption (C-terminal cross linking telopeptide of type I collagen, bone formation (osteocalcin, and BMD of the lumbar spine and proximal femur (dual-energy X-ray absorptiometry. Secondary outcomes include health-related quality-of-life, exercise behavior, and psychological well-being. In addition, kinetic and kinematic characterization of gait, standing, and rising from a chair are assessed in subset of participants (n = 16 to explore the feasibility of modeling skeletal

  15. Design and application of hybrid maxillomandibular fixation for facial bone fractures.

    Science.gov (United States)

    Park, Kang-Nam; Oh, Seung-Min; Lee, Chang-Youn; Kim, Jwa-Young; Yang, Byoung-Eun

    2013-01-01

    A novel maxillomandibular fixation (MMF) procedure using a skeletal anchorage screw (SAS) (in the maxilla) and an arch bar (in the mandible), which we call "hybrid maxillomandibular fixation," was explored in this study. The aims of the study were to examine the efficacy of our hybrid MMF method and to compare periodontal tissue health and occlusal rehabilitation among 3 MMF methods. In total, 112 patients who had undergone open reduction at the Department of Oral and Maxillofacial Surgery between September 2005 and December 2012 were selected for this study. The participants were assigned to one of the following groups: SAS (maxilla), SAS (mandible), SAS-arch bar, or arch bar-arch bar. Periodontal health was evaluated using the Gingival Index, and the perioperative occlusal reproducibility was evaluated using a score of 1 to 3. Statistical analysis was performed using parametric tests (Student t test or 1-way analysis of variance followed by post hoc Tukey test). In the Gingival Index comparison performed 1 month after the surgery, only the group using the arch bars and wiring was significantly different from the other groups (P fractures. In addition, it overcomes many problems presented by previous MMF methods.

  16. Dynamic aerofracture or hydrofracture of dense granular packing: pressure and viscosity control of the fracture patterns

    Science.gov (United States)

    Niebling, Michael J.; Toussaint, Renaud; Flekkøy, Eirik G.; Jørgen Måløy, Knut

    2013-04-01

    Stress induced by fluid or gases can cause diverse materials to break and fracture. Such hydraulic fractures are a natural and common phenomenon in the field of volcanism and are artificially initiated to enhance the recovery of natural gas and mineral oil by fracturing the reservoir rock with pressurized fluids. A procedure also known as fracking. Recently a new perspective on hydrofractures was added with the storage of supercritical CO2. In this respect two scenarios are considered. First it is one option to inject CO2 into existing hydrofractures, and second the injection of the CO2 can create additional fractures. The typical components for such fractures are a porous material and a compressible gas. The dynamics of such fractures and displacement patterns are simulated and studied in a rectangular Hele-Shaw cell filled with a dense but permeable two-dimensional granular layer. The model used, mixing highly deformable solid and fluid components, can simulate sedimentation problems [1,2], as well as hydrofracture or aerofracture ones. The emerging displacement patterns and fractures variate according to the properties of the injected fluid or gas and the characteristics of the granular phase [3]. The physics behind these variations is discussed and explained. The role of the fluid viscosity and system size shows to lead to a transition from fracturing to compaction, depending on the dynamics of convection versus diffusion of overpressure. The dependence of the obtained patterns on the injection pressure is also explored [4]. References: [1] Niebling, M.J., E.G. Flekkøy, K.J. Måløy, R. Toussaint, Sedimentation instabilities: impact of the fluid compressibility and viscosity, Phys. Rev. E 82, 051302, 2010. doi: 10.1103/PhysRevE.82.051302 [2] Niebling, M.J., E.G. Flekkøy, K.J. Måløy, R. Toussaint, Mixing of a granular layer falling through a fluid, Phys. Rev. E 82, 011301 (2010) doi: 10.1103/PhysRevE.82.011301 [3] Niebling, M., R. Toussaint, E.G. Flekk

  17. Effect of hormone therapy on the risk of bone fractures: a systematic review and meta-analysis of randomized controlled trials.

    Science.gov (United States)

    Zhu, Linlin; Jiang, Xinyan; Sun, Yuhong; Shu, Wenhuan

    2016-04-01

    The aim of this study was to investigate the association between hormone therapy (HT) use and the development of bone fractures. Using terms related to HT and fractures, we searched PubMed, Embase, and the Cochrane library for randomized controlled trials on HT and the associated risk of fractures published before August 2014. Two evaluators independently selected studies on the basis of predetermined selection criteria, and 28 studies were included in the meta-analysis. Summary estimates were obtained using fixed- or random-effects models as appropriate. A total of 28 studies included 33,426 participants and 2,516 fractures cases. The overall relative risk of HT was 0.74 (95% confidence interval [CI] 0.69-0.80) for total fractures, 0.72 (95% CI 0.53-0.98) for hip fractures, and 0.63 (95% CI 0.44-0.91) for vertebral fractures. In subgroup analyses, women of an age less than 60 years had lower risk of total fractures compared with women of an age more than 60 years (P = 0.003). Estradiol led to greater decrease in the risk of total fractures compared with conjugated equine estrogens (P =  .01). There is greater reduction in total fracture risk in trials of follow-up less than 36 months than that of follow-up more than 36 months (P = 0.003). No increase in the incidence of total cancer events but an increase in the incidence of thrombus was found to be associated with HT. HT is associated with a reduced risk of total, hip, and vertebral fractures, with a possible attenuation of this protection effect after it is stopped or when it is begun after 60 years. However, there may be an increase in the incidence of thrombus formation associated with HT.

  18. Antipsychotic treatment and the risk of hip fracture in subjects with schizophrenia: a 10-year population-based case-control study.

    Science.gov (United States)

    Wu, Chi-Shin; Chang, Chia-Ming; Tsai, Yu-Ting; Huang, Ya-Wen; Tsai, Hui-Ju

    2015-09-01

    To investigate the association between antipsychotic treatment and risk of hip fracture in subjects with schizophrenia. Among patients with schizophrenia (ICD-9-CM code 295), 605 cases with hip fracture and 2,828 matched controls were identified from 2002 to 2011 using the National Health Insurance Research Database in Taiwan. The authors conducted a nested case-control study to investigate the association between antipsychotic treatment and risk of hip fracture in subjects with schizophrenia. The modifiable effects of age and gender were evaluated by stratified analysis. In addition, the effects of antipsychotic use, antipsychotic classes, and receptor-binding profiles of antipsychotics, individually, on hip fracture were estimated, and potential confounding factors were adjusted in subsequent analysis. Conditional logistic regressions were applied to determine the effect of antipsychotic treatment on hip fracture. Current antipsychotic use was associated with an increased risk for hip fracture (adjusted odds ratio [AOR] = 1.61; 95% CI, 1.24-2.10). Among current users, new users had a higher risk of hip fracture (AOR = 4.28; 95% CI, 1.76-10.36) than past users (AOR = 1.11; 95% CI, 0.79-1.56). In addition, a significant increased risk of hip fracture was noted in schizophrenia subjects with first-generation antipsychotic use (AOR = 1.59; 95%CI, 1.15-2.20) but not in those with second-generation antipsychotic use (AOR = 1.16; 95% CI, 0.91-1.48). These results extend previous findings and demonstrate an increased risk of hip fracture associated with antipsychotic use in schizophrenia subjects. Further investigation is needed to dissect the underlying mechanisms related to the effect of antipsychotic use on hip fracture in subjects at risk. © Copyright 2015 Physicians Postgraduate Press, Inc.

  19. The effect of army vest design on the occurrence of stress fractures and overuse injuries in female military recruits.

    Science.gov (United States)

    Palmanovich, Ezequiel; Frankl, M; Nyska, M; Hetsroni, I; Constantini, N; Trejo, L; Bechar, R; Novak, G; Lankovsky, Z; Mann, G

    2017-08-01

    Stress fractures (SFs) occur when microdamage caused by repetitive mechanical load exceeds the biological load-bearing capacity of the bone. The study objective was to test whether a vest specifically designed and manufactured for female recruits, compared with the standard vest used on a regular basis by Border Police recruits, would reduce the incidence of SF in female Border Police recruits. Data based on reports of military personnel show that women are more likely to sustain SFs. A follow-up of 240 female Border Police infantry recruits, divided into two trial groups, was conducted from 2007 to 2009. Two different vests were evaluated-the standard special unit fighting vest, which was conventionally used by both men and women during basic training, and the new fighting vest, specially design for female body shape. No significant difference was noted in the number of SFs between the two groups which may be attributed to increased weight of the new vest. There was a lower incidence of long bone SFs which may have been due to the superior vest design. The female Border Police Infantry recruits expressed great satisfaction with the new vest. Increased effort should be invested to further reduce the weight of female combat gear, alongside efforts to improve fit and comfort. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  20. Robust System Identification and Control Design

    National Research Council Canada - National Science Library

    Zhou, Kemin

    2001-01-01

    ..., some advanced nonlinear control techniques including bifurcation stabilization and compressor stabilization techniques, model reduction techniques, fault detection and fault tolerant control methods...

  1. The CANDU 9 distributed control system design process

    International Nuclear Information System (INIS)

    Harber, J.E.; Kattan, M.K.; Macbeth, M.J.

    1997-01-01

    Canadian designed CANDU pressurized heavy water nuclear reactors have been world leaders in electrical power generation. The CANDU 9 project is AECL's next reactor design. Plant control for the CANDU 9 station design is performed by a distributed control system (DCS) as compared to centralized control computers, analog control devices and relay logic used in previous CANDU designs. The selection of a DCS as the platform to perform the process control functions and most of the data acquisition of the plant, is consistent with the evolutionary nature of the CANDU technology. The control strategies for the DCS control programs are based on previous CANDU designs but are implemented on a new hardware platform taking advantage of advances in computer technology. This paper describes the design process for developing the CANDU 9 DCS. Various design activities, prototyping and analyses have been undertaken in order to ensure a safe, functional, and cost-effective design. (author)

  2. Pain Relief After Operative Treatment of an Extremity Fracture: A Noninferiority Randomized Controlled Trial

    NARCIS (Netherlands)

    Helmerhorst, Gijs T. T.; Zwiers, Ruben; Ring, David; Kloen, Peter

    2017-01-01

    Opioid pain medication is frequently given to patients recovering from a surgical procedure for an extremity fracture in spite of evidence that acetaminophen may be adequate. The aim of this study was to determine whether prescription of step 1 pain medication (acetaminophen) is noninferior to step

  3. [Case-control study on cable-pin system in the treatment of olecranon fractures].

    Science.gov (United States)

    Ma, Hu-Jing; Shan, Lei; Zhou, Jun-Lin; Liu, Qing-He; Lu, Tie; Sun, Song

    2012-05-01

    To prospectively evaluate the clinical result of Cable-Pin system in the treatment of olecranon fractures and compare with tension band wiring (TBW) method. From March 2008 to June 2010,65 patients with olecranon fractures were divided into two groups: 32 patients in Cable-Pin group were treated with Cable-Pin system, including 18 males and 14 females, ranging in age from 21 to 69 years, with an average of (53.69 +/- 13.42) years; 33 patients in TBW group were treated with Kirschner tension bend, including 20 males and 13 females, ranging in age from 20 to 70 years, with an average of (53.18 +/- 13.36) years. The incision length, operation time, the amounts of hemoglobin after operation, fracture healing time, complications and HSS elbow scores were recorded and analyzed statistically. The follow-up period ranged from 12 to 24 months, with an average period of 18.4 months. There were statistical differences (PCable-Pin group. There was no statistical differences (P>0.05) in the length of incision (t= 0.416, P=0.679), operation time (t=0.816, P=0.417) and the postoperative amounts of hemoglobin (t=-0.553, P=0.294) between two groups. Cable-Pin system is an easy and reliable method for the treatment of olecranon fractures with less complications and better functions than TBW.

  4. Committee III.2 Fatigue and Fracture

    DEFF Research Database (Denmark)

    Brennan, F. P.; Branner, Kim; den Besten, J.H.

    2015-01-01

    Concern for crack initiation and growth under cyclic loading as well as unstable crack propagation and tearing in ship and offshore structures. Due attention shall be paid to practical application and statistical description of fracture control methods in design, fabrication and service. Consider......Concern for crack initiation and growth under cyclic loading as well as unstable crack propagation and tearing in ship and offshore structures. Due attention shall be paid to practical application and statistical description of fracture control methods in design, fabrication and service...

  5. Once-Yearly Zoledronic Acid and Days of Disability, Bed Rest, and Back Pain: Randomized, Controlled HORIZON Pivotal Fracture Trial

    Science.gov (United States)

    Cauley, Jane A.; Black, Dennis; Boonen, Steven; Cummings, Steven R.; Mesenbrink, Peter; Palermo, Lisa; Man, Zulema; Hadji, Peyman; Reid, Ian R.

    2016-01-01

    The objective of this study was to determine the effect of once-yearly zoledronic acid on the number of days of back pain and the number of days of disability (ie, limited activity and bed rest) owing to back pain or fracture in postmenopausal women with osteoporosis. This was a multicenter, randomized, double-blind, placebo-controlled trial in 240 clinical centers in 27 countries. Participants included 7736 postmenopausal women with osteoporosis. Patients were randomized to receive either a single 15-minute intravenous infusion of zoledronic acid (5 mg) or placebo at baseline, 12 months, and 24 months. The main outcome measures were self-reported number of days with back pain and the number of days of limited activity and bed rest owing to back pain or a fracture, and this was assessed every 3 months over a 3-year period. Our results show that although the incidence of back pain was high in both randomized groups, women randomized to zoledronic acid experienced, on average, 18 fewer days of back pain compared with placebo over the course of the trial (p = .0092). The back pain among women randomized to zoledronic acid versus placebo resulted in 11 fewer days of limited activity (p = .0017). In Cox proportional-hazards models, women randomized to zoledronic acid were about 6% less likely to experience 7 or more days of back pain [relative risk (RR) = 0.94, 95% confidence interval (CI) 0.90–0.99] or limited activity owing to back pain (RR = 0.94, 95% CI 0.87–1.00). Women randomized to zoledronic acid were significantly less likely to experience 7 or more bed-rest days owing to a fracture (RR = 0.58, 95% CI 0.47–0.72) and 7 or more limited-activity days owing to a fracture (RR = 0.67, 95% CI 0.58–0.78). Reductions in back pain with zoledronic acid were independent of incident fracture. Our conclusion is that in women with postmenopausal osteoporosis, a once-yearly infusion with zoledronic acid over a 3-year period significantly reduced the number of days that

  6. Concurrent Design of Embedded Control Software

    NARCIS (Netherlands)

    Groothuis, M.A.; Frijns, Raymond; Voeten, Jeroen; Broenink, Johannes F.; Margaria, T.; Padberg, J.; Taentzer, G.; Levendovszky, T.; Lengyel, L.; Karsai, G.; Hardebolle, C.

    2009-01-01

    Embedded software design for mechatronic systems is becoming an increasingly time-consuming and error-prone task. In order to cope with the heterogeneity and complexity, a systematic model-driven design approach is needed, where several parts of the system can be designed concurrently. There is

  7. Fracture mechanics

    International Nuclear Information System (INIS)

    Miannay, D.P.

    1995-01-01

    This book entitle ''Fracture Mechanics'', the first one of the monograph ''Materiologie'' is geared to design engineers, material engineers, non destructive inspectors and safety experts. This book covers fracture mechanics in isotropic homogeneous continuum. Only the monotonic static loading is considered. This book intended to be a reference with the current state of the art gives the fundamental of the issues under concern and avoids the developments too complicated or not yet mastered for not making reading cumbersome. The subject matter is organized as going from an easy to a more complicated level and thus follows the chronological evolution in the field. Similarly the microscopic scale is considered before the macroscopic scale, the physical understanding of phenomena linked to the experimental observation of the material preceded the understanding of the macroscopic behaviour of structures. In this latter field the relatively recent contribution of finite element computations with some analogy with the experimental observation is determining. However more sensitive analysis is not skipped

  8. [Treatment of posterior cruciate ligament avulsion fracture with rivet-assisted hollow nail:a case-control study].

    Science.gov (United States)

    Zhu, Jia-Fu; Ma, Gou-Ping; Xu, Wei-Xing; Guo, Qiao-Feng; Liu, Hong

    2017-04-25

    To retrospectively investigate the clinical effect of the rivet-assisted hollow screw in the treatment of posterior cruciate ligament avulsion fracture. Total 49 patients with knee cruciate ligament avulsion fracture in the ending point of the ligament from January 2010 to December 2014 were divided into the treatment group and the control group. Thirty-one patients in treatment group were treated with rivet-assisted double cannulate nail, including 13 males and 18 females, ranging in age from 38 to 51 years old, with a mean of (40.6±5.1) years old; according to Meyers classification, 23 cases of type 2, 8 cases of type 3; 5 patients were caused by the low energy injury and 26 patients were caused by the high energy injury. Eighteen patients in control group were treated with double gold hollow screw fixation, including 5 males and 13 females, ranging in age from 36 to 52 years old, with an average age of (4.16±4.7) years old; according to Meyers classification, 14 cases of type 2 and 4 cases of type 3;2 patients were caused by the low energy injury and 16 patients were caused by the high energy injury. The operation time, postoperative complications, fracture healing time and the last AKS scoring system were compared between the two groups. All the patients were followed up, and the duration ranged from 12 to 24 months, with an average of 14.2 months. The patients in treatment group had no displacement of fracture fragments and internal fixation failure. The results of AKS score:pain was 48.1±1.5, activity was 21.3±2.7, stability was 20.9±2.5, walking ability was 47.3±1.9, under the stairs ability was 43.4±2.1, the total score was 190.7±2.9. There were 2 cases in control group had fracture fragment displacement and 1 patient had nail withdraw. The results of AKS score:pain was 40.1±2.2, activity was 20.1±0.2, stability was 18.1±3.2, walking ability was 46.3±1.7, under the stairs ability was 40.2 ±1.3, the total score was 180.2±1.4. Therefore, the

  9. Femoral nerve block in a representative sample of elderly people with hip fracture: A randomised controlled trial.

    Science.gov (United States)

    Unneby, Anna; Svensson, Olle; Gustafson, Yngve; Olofsson, Birgitta

    2017-07-01

    The number of elderly people with hip fracture and dementia is increasing, and many of these patients suffer from pain. Opioids are difficult to adjust and side effects are common, especially with increased age and among patients with dementia. Preoperative femoral nerve block is an alternative pain treatment. To investigate whether preoperative femoral nerve block reduced acute pain and opioid use after hip fracture among elderly patients, including those with dementia. In this randomised controlled trial involving patients aged ≥70years with hip fracture (trochanteric and cervical), including those with dementia, we compared femoral nerve block with conventional pain management, with opioid use if required. The primary outcome was preoperative pain, measured at five timepoints using a visual analogue scale (VAS). Preoperative opioid consumption was also registered. The study sample comprised 266 patients admitted consecutively to the Orthopaedic Ward. The mean age was 84.1 (±6.9)years, 64% of participants were women, 44% lived in residential care facilities, and 120 (45.1%) had dementia diagnoses. Patients receiving femoral nerve block had significantly lower self-rated pain scores from baseline to 12h after admission than did controls. Self-rated and proxy VAS pain scores decreased significantly in these patients from baseline to 12h compared with controls (pblock required less opioids than did controls, overall (2.3±4.0 vs. 5.7±5.2mg, pblock had lower pain scores and required less opioids before surgery compared with those receiving conventional pain management. Femoral nerve block seems to be a feasible pain treatment for elderly people, including those with dementia. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  10. Robust control design verification using the modular modeling system

    International Nuclear Information System (INIS)

    Edwards, R.M.; Ben-Abdennour, A.; Lee, K.Y.

    1991-01-01

    The Modular Modeling System (B ampersand W MMS) is being used as a design tool to verify robust controller designs for improving power plant performance while also providing fault-accommodating capabilities. These controllers are designed based on optimal control theory and are thus model based controllers which are targeted for implementation in a computer based digital control environment. The MMS is being successfully used to verify that the controllers are tolerant of uncertainties between the plant model employed in the controller and the actual plant; i.e., that they are robust. The two areas in which the MMS is being used for this purpose is in the design of (1) a reactor power controller with improved reactor temperature response, and (2) the design of a multiple input multiple output (MIMO) robust fault-accommodating controller for a deaerator level and pressure control problem

  11. Mechanical Engineering Design Project report: Enabler control systems

    Science.gov (United States)

    Cullen, Christian; Delvecchio, Dave; Scarborough, Alan; Havics, Andrew A.

    1992-01-01

    The Controls Group was assigned the responsibility for designing the Enabler's control system. The requirement for the design was that the control system must provide a simple user interface to control the boom articulation joints, chassis articulation joints, and the wheel drive. The system required controlling hydraulic motors on the Enabler by implementing 8-bit microprocessor boards. In addition, feedback to evaluate positions and velocities must be interfaced to provide the operator with confirmation as well as control.

  12. Risk factors for falls with severe fracture in elderly people living in a middle-income country: a case control study

    OpenAIRE

    Coutinho, Evandro SF; Fletcher, Astrid; Bloch, Katia V; Rodrigues, Laura C

    2008-01-01

    Abstract Background Fracture after falling has been identified as an important problem in public health. Most studies of risk factors for fractures due to falls have been carried out in developed countries, although the size of the elderly population is increasing fast in middle income countries. The objective of this paper is to identify risk factors for fall related to severe fractures in those aged 60 or more in a middle-income country. Methods A case-control study was carried out in Rio d...

  13. Study on Design of Control Module and Fuzzy Control System

    International Nuclear Information System (INIS)

    Lee, Chang Kyu; Sohn, Chang Ho; Kim, Jung Seon; Kim, Min Kyu

    2005-01-01

    Performance of control unit is improved by introduction of fuzzy control theory and compensation for input of control unit as FLC(Fuzzy Logic Controller). Here, FLC drives thermal control system by linguistic rule-base. Hence, In case of using compensative PID control unit, it doesn't need to revise or compensate for PID control unit. Consequently, this study shows proof that control system which implements H/W module and then uses fuzzy algorism in this system is stable and has reliable performance

  14. Design of a distributed control system

    Energy Technology Data Exchange (ETDEWEB)

    Bilous, O [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

    1959-07-01

    A digital computer is used to evaluate various pressure control systems for a gaseous diffusion cascade. This is an example of a distributed feedback control system. The paper gives a brief discussion of similar cases of distributed or stage wise control systems, which may occur in multiple temperature control of chemical processes. (author) [French] Une calculatrice digitale est utilisee pour evaluer divers systemes de controle de pression pour une cascade de diffusion gazeuse. C'est un exemple de systeme de controle a reaction distribue. Le rapport presente une breve discussion de cas semblables de systemes de controle distribues ou en etage, qui peuvent se presenter dans de nombreux controles de temperature de reactions chimiques. (auteur)

  15. Probabilistic Design and Tuning of LQ Control

    Czech Academy of Sciences Publication Activity Database

    Belda, Květoslav

    2009-01-01

    Roč. 19, č. 4 (2009), s. 355-368 ISSN 1230-2384 Institutional research plan: CEZ:AV0Z10750506 Keywords : adaptive control * closed-loop control * dynamic programming * state- space realization * tuneable filters Subject RIV: BC - Control Systems Theory http://library.utia.cas.cz/separaty/historie/belda-0332706.pdf

  16. [The importance of early exercise therapy in the treatment of Colles' fracture. A clinically controlled study].

    Science.gov (United States)

    Grønlund, B; Harreby, M S; Kofoed, R; Rasmussen, L

    1990-08-27

    Forty patients participated in a study of the importance of early occupational therapy for the prognosis in stable Colles' fractures. Seventeen patients were treated by an occupational therapist 1-3 days after the injury, and the need for appliances and home-care was estimated. Twenty-three patients completed the usual treatment. Five weeks after the injury, we found significantly (p less than 0.05) better function of the hand in the 17 patients with early occupational therapy. This difference in function could not be found after 13 weeks. The rate of complications was the same in the two groups. The results indicate that contact with the occupational therapist shortly after the injury is valuable in patients with stable Colles' fractures.

  17. Cooperative adaptive cruise control, design and experiments

    NARCIS (Netherlands)

    Naus, G.J.L.; Vugts, R.P.A.; Ploeg, J.; Molengraft, van de M.J.G.; Steinbuch, M.

    2010-01-01

    The design of a CACC system and corresponding experiments are presented. The design targets string stable system behavior, which is assessed using a frequency-domain-based approach. Following this approach, it is shown that the available wireless information enables small inter-vehicle distances,

  18. Improving community ambulation after hip fracture: protocol for a randomised, controlled trial

    Directory of Open Access Journals (Sweden)

    D Orwig

    2017-01-01

    Discussion: This multicentre randomised study will be the first to test whether a home-based multi-component physiotherapy intervention targeting specific precursors of community ambulation (PUSH is more likely to lead to community ambulation than a home-based non-specific multi-component physiotherapy intervention (PULSE in older adults after hip fracture. The study will also estimate the potential economic value of the interventions.

  19. [Case control study of fractures-dislocations of ankle joint with conservative and operative treatment].

    Science.gov (United States)

    Zhang, Song-Tu; Lin, Yi-Rong; Chen, Lian-Yuan

    2010-10-01

    To compare the clinical efficacy of grade III, IV supination-eversion fractures-dislocations of ankle joint between manipulative treatment and operative treatment. From September 2007 to December 2008, the clinical data of 60 patients with grade III, IV supination-eversion fractures-dislocations of ankle joint were retrospectively analyzed. There were 32 males and 28 females, ranging in age from 18 to 70 years with an average age of 38.17 years. All patients were respectively treated with manipulative treatment (conservative group, 30 cases) and operative treatment (operative group, 30 cases). The joint function was compared with Mazur standard; the reduction and shifting of fractures were observed with X-ray; the hospitalization day and the therapeutic cost were compared between two groups. All patients were followed up with an average of 15.27 months (ranged, 6 to 25 months). In conservative group, 16 cases got excellent result in joint function, 10 good, 3 fair, 1 poor; in operative group, 20 cases got excellent result, 8 good, 2 fair, 0 poor. In conservative group in the X-ray showed 25 cases obtained excellent and good reduction, 4 fair, 1 poor; and in operative group in the X-ray showed 28 cases obtained excellent and good reduction, 2 fair, 0 poor. There was no significant difference at the joint function and X-ray film after treatment between two groups (P > 0.05). The hospital day was respectively (7.87 +/- 3.34), (17.37 +/- 4.64) d in conservative group and operative group; and the therapeutic cost was respectively (2 506.67 +/- 649.10), (11 473.33 +/- 1 564.90) yuan. There was significant difference at hospital day and therapeutic cost between two groups (P fractures and dislocations of ankle joint. However, conservative treatment has advantage of high safety factor, low therapeutic cost, can reduce medical costs for patients.

  20. Embedded Control System Design A Model Based Approach

    CERN Document Server

    Forrai, Alexandru

    2013-01-01

    Control system design is a challenging task for practicing engineers. It requires knowledge of different engineering fields, a good understanding of technical specifications and good communication skills. The current book introduces the reader into practical control system design, bridging  the gap between theory and practice.  The control design techniques presented in the book are all model based., considering the needs and possibilities of practicing engineers. Classical control design techniques are reviewed and methods are presented how to verify the robustness of the design. It is how the designed control algorithm can be implemented in real-time and tested, fulfilling different safety requirements. Good design practices and the systematic software development process are emphasized in the book according to the generic standard IEC61508. The book is mainly addressed to practicing control and embedded software engineers - working in research and development – as well as graduate students who are face...

  1. Television, computer, and video viewing; physical activity; and upper limb fracture risk in children: a population-based case control study.

    Science.gov (United States)

    Ma, Deqiong; Jones, Graeme

    2003-11-01

    The effect of physical activity on upper limb fractures was examined in this population-based case control study with 321 age- and gender-matched pairs. Sports participation increased fracture risk in boys and decreased risk in girls. Television viewing had a deleterious dose response association with wrist and forearm fractures while light physical activity was protective. The aim of this population-based case control study was to examine the association between television, computer, and video viewing; types and levels of physical activity; and upper limb fractures in children 9-16 years of age. A total of 321 fracture cases and 321 randomly selected individually matched controls were studied. Television, computer, and video viewing and types and levels of physical activity were determined by interview-administered questionnaire. Bone strength was assessed by DXA and metacarpal morphometry. In general, sports participation increased total upper limb fracture risk in boys and decreased risk in girls. Gender-specific risk estimates were significantly different for total, contact, noncontact, and high-risk sports participation as well as four individual sports (soccer, cricket, surfing, and swimming). In multivariate analysis, time spent television, computer, and video viewing in both sexes was positively associated with wrist and forearm fracture risk (OR 1.6/category, 95% CI: 1.1-2.2), whereas days involved in light physical activity participation decreased fracture risk (OR 0.8/category, 95% CI: 0.7-1.0). Sports participation increased hand (OR 1.5/sport, 95% CI: 1.1-2.0) and upper arm (OR 29.8/sport, 95% CI: 1.7-535) fracture risk in boys only and decreased wrist and forearm fracture risk in girls only (OR 0.5/sport, 95% CI: 0.3-0.9). Adjustment for bone density and metacarpal morphometry did not alter these associations. There is gender discordance with regard to sports participation and fracture risk in children, which may reflect different approaches to sport

  2. Use of self-controlled designs in pharmacoepidemiology

    DEFF Research Database (Denmark)

    Hallas, J.; Pottegård, Anton

    2014-01-01

    Self-controlled observational study designs, such as the case-crossover design and the self-controlled case series, are reviewed, and their respective rationale, strengths and limitations are compared. Although no single design is generally superior to the others, they share the trait of being...... robust towards confounders that are stable over time. The self-controlled designs can be particularly useful when using secondary healthcare data for pharmacoepidemiological research and might be useful in screening for adverse drug effects. The main limitations of self-controlled designs...

  3. Quantifying Fracture Heterogeneity in Different Domains of Folded Carbonate Rocks to Improve Fractured Reservoir Analog Fluid Flow Models

    NARCIS (Netherlands)

    Bisdom, K.; Bertotti, G.; Gauthier, B.D.M.; Hardebol, N.J.

    2013-01-01

    Fluid flow in carbonate reservoirs is largely controlled by multiscale fracture networks. Significant variations of fracture network porosity and permeability are caused by the 3D heterogeneity of the fracture network characteristics, such as intensity, orientation and size. Characterizing fracture

  4. Analytical design method for a truss-bolt system for reinforcement of fractured coal mine roofs - illustrated with a case study

    Energy Technology Data Exchange (ETDEWEB)

    Liu, B.; Yue, Z.Q.; Tham, L.G. [University of Hong Kong, Hong Kong (China). Dept. of Civil Engineering

    2005-02-01

    This paper presents an analytical design method for the truss-bolt system in reinforcing underground fractured rock roofs in coal mines. The analytical design method is based on the mechanical analysis of the fractured rock roof with reinforcement by inclined roof bolts and a horizontal tie-rod. The mechanical analysis for the system includes a non-linear bending model for the laterally inclined roof bolts and three upper and lower bounds. The lateral resistance of the inclined roof bolts in a truss-bolt-supported roadway is examined using classical theory of a non-linear beam in bending. The paper analyses the arching action by lateral behavior of the inclined roof bolts in reinforcing the fractured roof. Based on mechanical models, the design formula concerning the lateral bolt forces, tensions in the tie-rod in the truss system, as well as the reinforcement behavior have been derived. In order to ensure that the roof truss-bolt system reinforces the coal roof effectively, a lower bound of pre-tightening forces must be applied on the tie-rod for stabilizing the fractured roof by arching action. The pre-tightening forces exerted via the tie-rod also cannot be greater than its upper bound, since the excessive tightening force will cause localized failure in the rock near the bolt tail at the abutment of the fractured roof beam. The analytical formulas for both lower and upper bounds for truss pre-tightening forces are put forward in this paper. Furthermore, the paper also presents analytical equations for designing the axial forces and dimensions for bolts in this kind of system.

  5. A control center design revisited: learning from users’ appropriation

    DEFF Research Database (Denmark)

    Souza da Conceição, Carolina; Cordeiro, Cláudia

    2014-01-01

    This paper aims to present the lessons learned during a control center design project by revisiting another control center from the same company designed two and a half years before by the same project team. In light of the experience with the first project and its analysis, the designers and res...

  6. Improved fuzzy PID controller design using predictive functional control structure.

    Science.gov (United States)

    Wang, Yuzhong; Jin, Qibing; Zhang, Ridong

    2017-11-01

    In conventional PID scheme, the ensemble control performance may be unsatisfactory due to limited degrees of freedom under various kinds of uncertainty. To overcome this disadvantage, a novel PID control method that inherits the advantages of fuzzy PID control and the predictive functional control (PFC) is presented and further verified on the temperature model of a coke furnace. Based on the framework of PFC, the prediction of the future process behavior is first obtained using the current process input signal. Then, the fuzzy PID control based on the multi-step prediction is introduced to acquire the optimal control law. Finally, the case study on a temperature model of a coke furnace shows the effectiveness of the fuzzy PID control scheme when compared with conventional PID control and fuzzy self-adaptive PID control. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

  7. LMI–based robust controller design approach in aircraft multidisciplinary design optimization problem

    Directory of Open Access Journals (Sweden)

    Qinghua Zeng

    2015-07-01

    Full Text Available This article proposes a linear matrix inequality–based robust controller design approach to implement the synchronous design of aircraft control discipline and other disciplines, in which the variation in design parameters is treated as equivalent perturbations. Considering the complicated mapping relationships between the coefficient arrays of aircraft motion model and the aircraft design parameters, the robust controller designed is directly based on the variation in these coefficient arrays so conservative that the multidisciplinary design optimization problem would be too difficult to solve, or even if there is a solution, the robustness of design result is generally poor. Therefore, this article derives the uncertainty model of disciplinary design parameters based on response surface approximation, converts the design problem of the robust controller into a problem of solving a standard linear matrix inequality, and theoretically gives a less conservative design method of the robust controller which is based on the variation in design parameters. Furthermore, the concurrent subspace approach is applied to the multidisciplinary system with this kind of robust controller in the design loop. A multidisciplinary design optimization of a tailless aircraft as example is shown that control discipline can be synchronous optimal design with other discipline, especially this method will greatly reduce the calculated amount of multidisciplinary design optimization and make multidisciplinary design optimization results more robustness of flight performance.

  8. Fault tolerant control design for hybrid systems

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Hao; Jiang, Bin [Nanjing University of Aeronautics and Astronautics, Nanjing (China); Cocquempot, Vincent [Universite des Sciences et Technologies de Lille, Villeneuve d' Ascq (France)

    2010-07-01

    This book intends to provide the readers a good understanding on how to achieve Fault Tolerant Control goal of Hybrid Systems. The book can be used as a reference for the academic research on Fault Tolerant Control and Hybrid Systems or used in Ph.D. study of control theory and engineering. The knowledge background for this monograph would be some undergraduate and graduate courses on Fault Diagnosis and Fault Tolerant Control theory, linear system theory, nonlinear system theory, Hybrid Systems theory and Discrete Event System theory. (orig.)

  9. AI-based adaptive control and design of autopilot system

    Indian Academy of Sciences (India)

    The objective of this paper is to design an autopilot system for unmanned aerial vehicle (UAV) to control the speed and altitude using electronic throttle control system (ETCS) and elevator, respectively. A DC servo motor is used for designing of ETCS to control the throttle position for appropriate amount of air mass flow.

  10. Use of the Human Centered Design concept when designing ergonomic NPP control rooms

    International Nuclear Information System (INIS)

    Skrehot, Petr A.; Houser, Frantisek; Riha, Radek; Tuma, Zdenek

    2015-01-01

    Human-Centered Design is a concept aimed at reconciling human needs on the one hand and limitations posed by the design disposition of the room being designed on the other hand. This paper describes the main aspects of application of the Human-Centered Design concept to the design of nuclear power plant control rooms. (orig.)

  11. Unblinded randomized control trial on prophylactic antibiotic use in gustilo II open tibia fractures at Kenyatta National Hospital, Kenya.

    Science.gov (United States)

    Ondari, Joshua Nyaribari; Masika, Moses Muia; Ombachi, Richard Bwana; Ating'a, John Ernest

    2016-10-01

    To determine the difference in infection rate between 24h versus five days of prophylactic antibiotic use in management of Gustilo II open tibia fractures. Unblinded randomized control trial. Accident and Emergency, orthopedic wards and outpatient clinics at Kenyatta National Hospital (KNH). The study involved patients aged 18-80 years admitted through accident and emergency department with Gustilo II traumatic open tibia fractures. Patients were randomized into either 24hour or five day group and antibiotics started for 24hours or five days after surgical debridement. The wounds were exposed and scored using ASEPSIS wound scoring system for infection after 48h, 5days and at 14days. The main outcomes of interest were presence of infection at days 2, 5 and 14 and effect of duration to antibiotic administration on infection rate. There was no significant difference in infection rates between 24-hour and 5-day groups with infection rates of 23% (9/40) vs. 19% (7/37) respectively (p=0.699). The infection rate was significantly associated with time lapsed before administration of antibiotics (p=0.004). In the use of prophylactic antibiotics for the management of Gustilo II traumatic open tibia fractures, there is no difference in infection rate between 24hours and five days regimen but time to antibiotic administration correlates with infection rate. Antibiotic use for 24hours only has proven adequate prophylaxis against infection. This is underlined in our study which we hope shall inform practice in our setting. A larger, more appropriately controlled study would be useful. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Designing, Assessing, and Demonstrating Sustainable Bioaugmentation for Treatment of DNAPL Sources in Fractured Bedrock

    Science.gov (United States)

    2017-01-27

    South Air Force Research Laboratory), and the former Nike Battery PR-58 site (RI). Of these sites, AFP6 was excluded because of the depth to...recirculation system was completed by a CB&I engineer and Calcon Systems, Inc . (electrical controls support) on July 2, 2014. Groundwater recirculation began on...porous media. Ground Water 2013 51, 58-65. (56) Earth Tech, Inc . Environmental Restoration Program, Record of Decision, South Air Force Research

  13. Conceptual design of HL-2M tokamak control system

    International Nuclear Information System (INIS)

    Xia Fan; Chen Liaoyuan; Song Xianming; Zhang Jinhua; Lou Cuiwen; Pan Yudong

    2009-01-01

    The static architecture, dynamic behavior, control theory and simulation of HL-2M tokamak control system are described. The real-time network will be build for the communication of real-time control among its subsystems and universal timing system will be build to guarantee the synchronization among the subsystems. The duty to achieve preprogrammed parameters is carried out by plasma discharge control. In order to reduce the damage made by discharge exception, the error-handing mechanism of supervision system is considered. The controllers of magnetic control system are designed to control the current, shape and position of plasma and simulation system is designed for testing the controllers. (authors)

  14. Model based design of electronic throttle control

    Science.gov (United States)

    Cherian, Fenin; Ranjan, Ashish; Bhowmick, Pathikrit; Rammohan, A.

    2017-11-01

    With the advent of torque based Engine Management Systems, the precise control and robust performance of the throttle body becomes a key factor in the overall performance of the vehicle. Electronic Throttle Control provides benefits such as improved air-fuel ratio for improving the vehicle performance and lower exhausts emissions to meet the stringent emission norms. Modern vehicles facilitate various features such as Cruise Control, Traction Control, Electronic Stability Program and Pre-crash systems. These systems require control over engine power without driver intervention, which is not possible with conventional mechanical throttle system. Thus these systems are integrated to function with the electronic throttle control. However, due to inherent non-linearities in the throttle body, the control becomes a difficult task. In order to eliminate the influence of this hysteresis at the initial operation of the butterfly valve, a control to compensate the shortage must be added to the duty required for starting throttle operation when the initial operation is detected. Therefore, a lot of work is being done in this field to incorporate the various nonlinearities to achieve robust control. In our present work, the ETB was tested to verify the working of the system. Calibration of the TPS sensors was carried out in order to acquire accurate throttle opening angle. The response of the calibrated system was then plotted against a step input signal. A linear model of the ETB was prepared using Simulink and its response was compared with the experimental data to find out the initial deviation of the model from the actual system. To reduce this deviation, non-linearities from existing literature were introduced to the system and a response analysis was performed to check the deviation from the actual system. Based on this investigation, an introduction of a new nonlinearity parameter can be used in future to reduce the deviation further making the control of the ETB more

  15. Adherence With Bisphosphonates and Long-Term Risk of Hip Fractures: A Nested Case-Control Study Using Real-World Data.

    Science.gov (United States)

    Shalev, Varda; Sharman Moser, Sarah; Goldshtein, Inbal; Yu, Jingbo; Weil, Clara; Ish-Shalom, Sophia; Rouach, Vanessa; Chodick, Gabriel

    2017-09-01

    Hip fracture is a major complication of osteoporosis. Bisphosphonate medication is the mainstay of treatment for osteoporosis. However, concerns have been raised regarding the effectiveness of bisphosphonates in reducing hip fracture risk after long-term use, particularly among patients with suboptimal adherence. To examine the association between adherence with bisphosphonate therapy and long-term risk of hip fracture. Included in the present nested case-control study were osteoporotic women (n = 14 357) who initiated bisphosphonate therapy in 2000-2010 and were retrospectively followed for incident hip fracture through November 2014. Within this cohort, each case of primary hip fractures was individually matched to 3 controls without a primary hip fracture. Proportion of follow-up days covered (PDC) with bisphosphonates was calculated from bisphosphonate purchases. Adherence was categorized into the following groups: purchase of 1 or 2 months' supply (reference group), at least 3 months' supply to PDC ≤20%, PDC >20% to ≤80%, PDC >80% to ≤100%. Included in the analysis were 426 case-control groups with a mean age (SD) of 73.7 years (7.9). Compared with the reference group, PDC of 80% to 100% with bisphosphonates was associated with a significant reduction in hip fracture risk for patients with 8 to 15 years of follow-up (OR = 0.39; 95% CI = 0.18-0.87). Among patients with a follow-up of up to 3 years, OR was 0.58 (95% CI = 0.31-1.06). Adherence with bisphosphonates among osteoporotic patients is associated with lower risk of hip fracture, with no indication of diminished effectiveness with long-term use.

  16. Design and Implementation of Temperature Controller for a Vacuum Distiller

    OpenAIRE

    Muslim, M. Aziz; N., Goegoes Dwi; F., Ahmad Salmi; R., Akhbar Prachaessardhi

    2014-01-01

    This paper proposed design and implementation of temperature controller for a vacuum distiller. The distiller is aimed to provide distillation process of bioethanol in nearly vacuum condition. Due to varying vacuum pressure, temperature have to be controlled by manipulating AC voltage to heating elements. Two arduino based control strategies have been implemented, PID control and Fuzzy Logic control. Control command from the controller was translated to AC drive using TRIAC based dimmer circu...

  17. Fuzzy control. Fundamentals, stability and design of fuzzy controllers

    Energy Technology Data Exchange (ETDEWEB)

    Michels, K. [Fichtner GmbH und Co. KG, Stuttgart (Germany); Klawonn, F. [Fachhochschule Braunschweig/Wolfenbuettel (Germany). Fachbereich Informatik; Kruse, R. [Magdeburg Univ. (Germany). Fakultaet Informatik, Abt. Wiss.- und Sprachverarbeitung; Nuernberger, A. (eds.) [California Univ., Berkeley, CA (United States). Computer Science Division

    2006-07-01

    The book provides a critical discussion of fuzzy controllers from the perspective of classical control theory. Special emphases are placed on topics that are of importance for industrial applications, like (self-) tuning of fuzzy controllers, optimisation and stability analysis. The book is written as a textbook for graduate students as well as a comprehensive reference book about fuzzy control for researchers and application engineers. Starting with a detailed introduction to fuzzy systems and control theory the reader is guided to up-to-date research results. (orig.)

  18. Practical Loop-Shaping Design of Feedback Control Systems

    Science.gov (United States)

    Kopasakis, George

    2010-01-01

    An improved methodology for designing feedback control systems has been developed based on systematically shaping the loop gain of the system to meet performance requirements such as stability margins, disturbance attenuation, and transient response, while taking into account the actuation system limitations such as actuation rates and range. Loop-shaping for controls design is not new, but past techniques do not directly address how to systematically design the controller to maximize its performance. As a result, classical feedback control systems are designed predominantly using ad hoc control design approaches such as proportional integral derivative (PID), normally satisfied when a workable solution is achieved, without a good understanding of how to maximize the effectiveness of the control design in terms of competing performance requirements, in relation to the limitations of the plant design. The conception of this improved methodology was motivated by challenges in designing control systems of the types needed for supersonic propulsion. But the methodology is generally applicable to any classical control-system design where the transfer function of the plant is known or can be evaluated. In the case of a supersonic aerospace vehicle, a major challenge is to design the system to attenuate anticipated external and internal disturbances, using such actuators as fuel injectors and valves, bypass doors, and ramps, all of which are subject to limitations in actuator response, rates, and ranges. Also, for supersonic vehicles, with long slim type of structures, coupling between the engine and the structural dynamics can produce undesirable effects that could adversely affect vehicle stability and ride quality. In order to design distributed controls that can suppress these potential adverse effects, within the full capabilities of the actuation system, it is important to employ a systematic control design methodology such as this that can maximize the

  19. Bifurcation-free design method of pulse energy converter controllers

    International Nuclear Information System (INIS)

    Kolokolov, Yury; Ustinov, Pavel; Essounbouli, Najib; Hamzaoui, Abdelaziz

    2009-01-01

    In this paper, a design method of pulse energy converter (PEC) controllers is proposed. This method develops a classical frequency domain design, based on the small signal modeling, by means of an addition of a nonlinear dynamics analysis stage. The main idea of the proposed method consists in fact that the PEC controller, designed with an application of the small signal modeling, is tuned after with taking into the consideration an essentially nonlinear nature of the PEC that makes it possible to avoid bifurcation phenomena in the PEC dynamics at the design stage (bifurcation-free design). Also application of the proposed method allows an improvement of the designed controller performance. The application of this bifurcation-free design method is demonstrated on an example of the controller design of direct current-direct current (DC-DC) buck converter with an input electromagnetic interference filter.

  20. Project Design Concept for Monitoring and Control System

    International Nuclear Information System (INIS)

    MCGREW, D.L.

    2000-01-01

    This Project Design Concept represents operational requirements established for use in design the tank farm Monitoring and Control System. These upgrades are included within the scope of Project W-314, Tank Farm Restoration and Safe Operations

  1. Hip Fracture

    Science.gov (United States)

    ... hip fractures in people of all ages. In older adults, a hip fracture is most often a result of a fall from a standing height. In people with very weak bones, a hip fracture can occur simply by standing on the leg and twisting. Risk factors The rate of hip fractures increases substantially with ...

  2. First Workshop on Design and Construction of Deep Repositories - Theme: Excavation through water-conducting major fracture zones

    International Nuclear Information System (INIS)

    Baeckblom, G.; Svemar, C.

    1994-01-01

    Final disposal of high-level nuclear waste has not yet been carried out in any country today. The concepts under development are all based on geological repositories, i.e., disposal at a sufficient depth below the surface to provide stable mechanical, hydrological and chemical conditions during the period the waste needs to be isolated from man. In the cases where crystalline bedrock is considered the proposed repository depths vary between 300-1000 m. The construction, operation and sealing of a deep geological repository must meet various criteria that in many respects are more detailed and more demanding than usual in underground construction projects today. The work shall be done so that occupational safety is ensured. The work also shall conform to whatever restrictions are necessary for ensuring pre-closure operational safety and post-closure long-term safety. March 1993 SKB arranged a two-day international workshop to discuss design and construction of repositories. Close to 40 participants from eight countries shared experiences regarding passage of major water-conducting fracture zones and other matters. This report summarizes the contributions to the workshop

  3. Design fractures and commercial potential of superconducting magnetic energy storage for electric utility application

    International Nuclear Information System (INIS)

    Lloyd, R.J.; Schoenung, S.

    1986-01-01

    Historically, energy storage in the United States has been provided by a few pumped hydroelectric plants, but siting constraints and high cost severely limit the use of this option. Two other options which will soon be in use are batteries and compressed air energy storage. A fourth option, currently being developed for load leveling is Superconducting Magnetic Energy Storage (SMES). This paper reports the design features and estimated costs of utility scale SMES plants. For moderate discharge duration, SMES is projected to have substantially lower revenue requirements and better availability than other load leveling options. The Electric Power Research Institute has prepared a plan for commercialization which could, if aggressively pursued, lead to a demonstrated SMES technology that is available for utility commitment by the late 1990's

  4. Fracture mechanics in new designed power module under thermo-mechanical loads

    Directory of Open Access Journals (Sweden)

    Durand Camille

    2014-06-01

    Full Text Available Thermo-mechanically induced failure is a major reliability issue in the microelectronic industry. On this account, a new type of Assembly Interconnected Technology used to connect MOSFETs in power modules has been developed. The reliability is increased by using a copper clip soldered on the top side of the chip, avoiding the use of aluminium wire bonds, often responsible for the failure of the device. Thus the new designed MOSFET package does not follow the same failure mechanisms as standard modules. Thermal and power cycling tests were performed on these new packages and resulting failures were analyzed. Thermo-mechanical simulations including cracks in the aluminium metallization and intermetallics (IMC were performed using Finite Element Analysis in order to better understand crack propagation and module behaviour.

  5. Unified Controller Design for Intelligent Manufacturing Automation

    National Research Council Canada - National Science Library

    Kosut, Robert

    1997-01-01

    .... The demonstration system selected was rapid thermal processing (RTP) of semiconductor wafers. This novel approach in integrated circuit manufacturing demands fast tracking control laws that achieve near uniform spatial temperature distributions...

  6. Control System Design for a Flexible Arm

    National Research Council Canada - National Science Library

    Wang, Li-Sheng

    1987-01-01

    .... He has investigated techniques for compensating the effects of friction and ripple torque. New software was written to use a Metrabyte Data Acquisition and Control board for the real-time implementation...

  7. Designing RF control subsystems using the VXIbus standard

    International Nuclear Information System (INIS)

    Stepp, J.D.; Vong, F.C.; Bridges, J.F.

    1993-01-01

    Various components are being designed to control the RF system of the 7-GeV Advanced Photon Source (APS). The associated control electronics (phase shifters, amplitude modulators, phase detectors, automatic tuning control, and local feedback control) are designed as modular cards with multiple channels for ease of replacement as well as for compact design. Various specifications of the VXIbus are listed and the method used to simplify the design of the control subsystem is shown. A commercial VXI interface board was used to speed the design cycle. Required manpower and actual task times are included. A discussion of the computer architecture and software development of the device drivers which allowed computer control from a VME processor located in a remote crate operating under the Experimental Physics and Industrial Controls Software (EPICS) program is also presented

  8. [Clinical randomized controlled trial on ultrashort wave and magnetic therapy for the treatment of early stage distal radius fractures].

    Science.gov (United States)

    Wang, Guan-Jie; Liu, Jia

    2012-07-01

    To explore the effect of application of ultrashort wave and magnetic therapy instrument on the swelling regression in distal radius fractures treated by splint external fixation in initial stage. From March 2007 to May 2010,90 patients with distal radial fracture were treated by manual reduction and splint external fixation. After manual reduction and small splints external fixation, these patients were randomly divided into electrical physical therapy group, western medicine group and the control group by the order of calling number, with 30 cases each group. In control group, there were 9 males and 21 females with an average age of (61.29 +/- 1.97) years, the patients raised and exercise the limb and fingers only. The other two groups also carried out this treatment. In electrical physical therapy group, there were 9 males and 21 females with an average age of (62.37 +/- 2.48) years, the patients were treated with ultrashort wave and magnetic therapy instrument for early intervention, once a day, 5 days for a course of treatment and three cycle were operated. In western medicine group,there were 8 males and 22 females with an average age of (60.12 +/- 2.87) years, the patients were injected with beta-aescin (20 mg, intravenous injection,once a day) for 5 days, followed by Danshen injection (20 ml, intravenous injection, once a day) for 10 days. The limb swelling of patients were assessed every day for 20 days after manual reduction and small splints external fixation. The time of swelling regression in electrical physical therapy group, western medicine group and the control group were respectively (9.62 +/- 3.32), (10.05 +/- 3.05) and (14.57 +/- 2.93) days. Both of that in electrical physical therapy group and western medicine group were shorter than that in the control group (P0.05). The effective rate of swelling regression in electrical physical therapy group, western medicine group and the control group were 86.67%, 80.00%, 46.66% respectively. There was no

  9. Model based design introduction: modeling game controllers to microprocessor architectures

    Science.gov (United States)

    Jungwirth, Patrick; Badawy, Abdel-Hameed

    2017-04-01

    We present an introduction to model based design. Model based design is a visual representation, generally a block diagram, to model and incrementally develop a complex system. Model based design is a commonly used design methodology for digital signal processing, control systems, and embedded systems. Model based design's philosophy is: to solve a problem - a step at a time. The approach can be compared to a series of steps to converge to a solution. A block diagram simulation tool allows a design to be simulated with real world measurement data. For example, if an analog control system is being upgraded to a digital control system, the analog sensor input signals can be recorded. The digital control algorithm can be simulated with the real world sensor data. The output from the simulated digital control system can then be compared to the old analog based control system. Model based design can compared to Agile software develop. The Agile software development goal is to develop working software in incremental steps. Progress is measured in completed and tested code units. Progress is measured in model based design by completed and tested blocks. We present a concept for a video game controller and then use model based design to iterate the design towards a working system. We will also describe a model based design effort to develop an OS Friendly Microprocessor Architecture based on the RISC-V.

  10. Experimental control of calculation model of scale factor during fracture of circular samples with cracks

    International Nuclear Information System (INIS)

    Gnyp, I.P.; Ganulich, B.K.; Pokhmurskij, V.I.

    1982-01-01

    Reliable methods of estimation of cracking resistance of low-strength plastic materials using the notched samples acceptable for laboratory tests are analysed. Experimental data on the fracture of round notched samples for a number of steels are given. A perfect comparability of calculational and experimental data confirms the legitimacy of the proposed scheme of estimation of the scale factor effect. The necessity of taking into account the strain hardening coefficient at the choice of a sample size for determining the stress intensity factor is pointed out

  11. [Comparison of clinical effectiveness of thoracic epidural and intravenous patient-controlled analgesia for the treatment of rib fractures pain in intensive care unit].

    Science.gov (United States)

    Topçu, Ismet; Ekici, Zeynep; Sakarya, Melek

    2007-07-01

    The results of thoracic epidural and systemic patient controlled analgesia practice were evaluated retrospectively in patients with thoracic trauma. Patients who were admitted to the intensive care unit between 1997 and 2003, with a diagnosis of multiple rib fractures related to thoracic trauma were evaluated retrospectively. Data were recorded from 49 patients who met the following criteria; three or more rib fractures, initiation of PCA with I.V. phentanyl or thoracic epidural analgesia with phentanyl and bupivacaine. There were no significant differences between the groups concerning injury severity score. APACHE II score (8.1+/-1.6 and 9.2+/-1.7) and the number of rib fractures (4+/-1.1 and 6.8+/-2.7) were higher in thoracic epidural analgesia group (pPain scores of patients who received thoracic epidural analgesia were significantly lower as from 6th hour during whole therapy (prib fractures who require intensive care.

  12. Integrated Intelligent Modeling, Design and Control of Crystal Growth Processes

    National Research Council Canada - National Science Library

    Prasad, V

    2000-01-01

    .... This MURI program took an integrated approach towards modeling, design and control of crystal growth processes and in conjunction with growth and characterization experiments developed much better...

  13. Active noise control in fuselage design

    NARCIS (Netherlands)

    Krakers, L.A.; Tooren, M.J.L. van; Beukers, A.; Berkhof, A.P.; Goeje, M.P. de

    2003-01-01

    To achieve comfortable noise levels inside the passenger cabin, sound damping measures have to be taken to improve the sound insulation properties of the bare airframe. Usually the sound insulation requirements of a passenger cabin are met after the mechanical design of the fuselage structure is

  14. Model reduction in integrated controls-structures design

    Science.gov (United States)

    Maghami, Peiman G.

    1993-01-01

    It is the objective of this paper to present a model reduction technique developed for the integrated controls-structures design of flexible structures. Integrated controls-structures design problems are typically posed as nonlinear mathematical programming problems, where the design variables consist of both structural and control parameters. In the solution process, both structural and control design variables are constantly changing; therefore, the dynamic characteristics of the structure are also changing. This presents a problem in obtaining a reduced-order model for active control design and analysis which will be valid for all design points within the design space. In other words, the frequency and number of the significant modes of the structure (modes that should be included) may vary considerably throughout the design process. This is also true as the locations and/or masses of the sensors and actuators change. Moreover, since the number of design evaluations in the integrated design process could easily run into thousands, any feasible order-reduction method should not require model reduction analysis at every design iteration. In this paper a novel and efficient technique for model reduction in the integrated controls-structures design process, which addresses these issues, is presented.

  15. Vitamin K1 and 25(OH)D are independently and synergistically associated with a risk for hip fracture in an elderly population: a case control study.

    Science.gov (United States)

    Torbergsen, Anne C; Watne, Leiv O; Wyller, Torgeir B; Frihagen, Frede; Strømsøe, Knut; Bøhmer, Thomas; Mowe, Morten

    2015-02-01

    The incidence of hip fractures in Oslo is among the highest in the world. Vitamin D, as well as vitamin K, may play an important role in bone metabolism. We examined if vitamin K1 and 25(OH)D were associated with an increased risk of hip fracture, and whether the possible synergistic effect of these two micronutrients is mediated through bone turnover markers. Blood was drawn for vitamin K1, 25(OH)D, and the bone turnover marker osteocalcin upon admission for hip fracture and in healthy controls. Vitamin K1 and 25(OH)D were independently associated with a risk of hip fracture. The adjusted odds ratio (95% CI) per ng/ml increase in vitamin K1 was 0.07 (0.02-0.32), and that per nmol/L increase in 25(OH)D was 0.96 (0.95-0.98). There was a significant interaction between 25(OH)D and vitamin K1 (p vitamin K1 and 25(OH)D (rho = 0.18, p = 0.01; rho = 0.20, p = 0.01, respectively). Vitamin K1 and 25(OH)D are lower in hip fracture patients compared with controls. Vitamin K1 and 25(OH)D are independently and synergistically associated with the risk of hip fracture when adjusting for confounders. Intervention studies should include both vitamins. Crown Copyright © 2014. Published by Elsevier Ltd. All rights reserved.

  16. Design of a hybrid command and control mobile botnet

    CSIR Research Space (South Africa)

    Pieterse, H

    2013-05-01

    Full Text Available and control mobile botnet. The hybrid design explores the efficiency of multiple command and control channels against the following objectives: no single point of failure within the topology, low cost for command dissemination, limited network activities...

  17. The System 80+ Standard Plant design control document. Volume 20

    International Nuclear Information System (INIS)

    1997-01-01

    This Design Control Document (DCD) is a repository of information comprising the System 80+trademark Standard Plant Design. The DCD also provides that design-related information to be incorporated by reference in the design certification rule for the System 80+ Standard Plant Design. Applicants for a combined license pursuant to 10 CFR 52 must ensure that the final Design Certification Rule and the associated Statements of Consideration are used when making all licensing decisions relevant to the System 80+ Standard Plant Design. The Design Control Document contains the DCD introduction, The Certified Design Material (CDM) [i.e., ''Tier 1''] and the Approved Design Material (ADM) [i.e., ''Tier 2''] for the System 80+ Standard Plant Design. The CDM includes the following sections: (1) Introductory material; (2) Certified Design Material for System 80+ systems and structures; (3) Certified Design Material for non-system-based aspects of the System 80+ Certified design; (4) Interface requirements; and (5) Site parameters. The ADM, to the extent applicable for the System 80+ Standard Plant Design, includes: (1) the information required for the final safety analysis report under 20 CFR 50.34; (2) other relevant information required by 10 CFR 52.47; and (3) emergency operations guidelines. This volume contains 2 technical specifications bases as part of Appendix 16 A Tech Spec Bases. They are TS B3.8 Electrical Power Technical Systems Bases and TS B3.9 Refueling Operations Bases. All 3 parts of section 17 (QA) and all 10 parts of section 18 (Human Factors) of the ADM Design and Analysis are contained in this volume. Topics covered in section 17 are: design phase QA; operations phase QA; and design phase reliability assurance. Topics covered by section 18 are: design team organization; design goals; design process; functional task analysis; control room configuration; information presentation; control and monitoring; verification and validation; and review documents

  18. Symbolics in control design: prospects and research issues

    DEFF Research Database (Denmark)

    Christensen, Anders

    1994-01-01

    The symbolic processor is targeted as a novel basic service in computer aided control system design. Basic symbolic tools are exemplified. A design process model is formulated for control design, with subsets manipulator, tools, target and goals. It is argued, that symbolic processing will give...... substantial contributions to future design environments, as it provides flexibility of representation not possible with traditional numerics. Based on the design process, views on research issues in the incorporation of symbolic processing into traditional numerical design environments are given...

  19. Polymer liquids fracture like solids

    DEFF Research Database (Denmark)

    Huang, Qian; Hassager, Ole

    2017-01-01

    While fracture in brittle solids has been studied for centuries until today, there are few studies on fracture in polymer liquids. Recent developments in experimental techniques, especially the combination of controlled filament stretching rheometry and high speed imaging, have opened new windows...... into the detailed study of fracture processes for polymer liquids. High speed imaging shows that polymer liquids fracture like solids with initiation and propagation of an edge fracture. However, remarkable features such as highly reproducible critical stress, independent appearance of multiple fractures...

  20. Microgrid Plant Control Design and Development

    Energy Technology Data Exchange (ETDEWEB)

    Wiegman, Herman [GE Global Research, Niskayuna, New York (United States); Baone, Chaitanya [GE Global Research, Niskayuna, New York (United States)

    2017-08-14

    This report discusses the technical performance of the proposed microgrid at Potsdam, New York, and the enhanced microgrid controller platform. The test objectives were outlined by the DOE, and summary results and discussion are given for each objective. The findings show that the proposed Potsdam, NY microgrid would have a significant impact on the regional CO2 emissions, the amount of imported energy from the utility, and the resiliency of the critical loads. Additionally, the enhanced microgrid control system developed for this project was tested to be compliant with IEEE 1547 standards, and able to generate revenues to help offset energy costs by way of participation in ancillary services.

  1. Design features of an automated entry control system

    International Nuclear Information System (INIS)

    Reynolds, D.A.

    1978-01-01

    Features of an entry control system designed to automatically control access to nuclear facilities is described. Control independent of variable human factors is stressed, but security force action is required for assessment and response as a result of an alarm. A design based on a distributed processing capability is utilized. Flexibility and generality are emphasized in an effort to maximize applicability to the entry-control problem faced by nuclear facilities upgrading security as a result of the Safeguards Program

  2. Design of dual DC motor control system based on DSP

    Science.gov (United States)

    Shi, Peicheng; Wang, Suo; Xu, Zengwei; Xiao, Ping

    2017-08-01

    Multi-motor control systems are widely used in actual production and life, such as lifting stages, robots, printing systems. This paper through serial communication between PC and DSP, dual DC motor control system consisting of PC as the host computer, DSP as the lower computer with synchronous PWM speed regulation, commutation and selection functions is designed. It sends digital control instructions with host computer serial debugger to lower computer, to instruct the motor to complete corresponding actions. The hardware and software design of the control system are given, and feasibility and validity of the control system are verified by experiments. The expected design goal is achieved.

  3. Design requirement on KALIMER control rod assembly duct

    International Nuclear Information System (INIS)

    Hwang, W.; Kang, H. Y.; Nam, C.; Kim, J. O.; Kim, Y. J.

    1998-03-01

    This document establishes the design guidelines which are needs for designing the control rod assembly duct of the KALIMER as design requirements. it describes control rod assembly duct of the KALIMER and its requirements that includes functional requirements, performance requirements, interfacing systems, design limits and strength requirements, seismic requirements, structural requirements, environmental requirements, reliability and safety requirements, standard and codes, QA programs, and other requirements. The control rod system consists of three parts, which are drive mechanism, drive-line, and absorber bundle. This report deals with the absorber bundle and its outer duct only because the others are beyond the scope of fuel system design. The guidelines for design requirements intend to be used for an improved design of the control rod assembly duct of the KALIMER. (author). 19 refs

  4. Design requirement on KALIMER control rod assembly duct

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, W.; Kang, H. Y.; Nam, C.; Kim, J. O.; Kim, Y. J

    1998-03-01

    This document establishes the design guidelines which are needs for designing the control rod assembly duct of the KALIMER as design requirements. it describes control rod assembly duct of the KALIMER and its requirements that includes functional requirements, performance requirements, interfacing systems, design limits and strength requirements, seismic requirements, structural requirements, environmental requirements, reliability and safety requirements, standard and codes, QA programs, and other requirements. The control rod system consists of three parts, which are drive mechanism, drive-line, and absorber bundle. This report deals with the absorber bundle and its outer duct only because the others are beyond the scope of fuel system design. The guidelines for design requirements intend to be used for an improved design of the control rod assembly duct of the KALIMER. (author). 19 refs.

  5. Case-control study of high-speed exercise history of Thoroughbred and Quarter Horse racehorses that died related to a complete scapular fracture.

    Science.gov (United States)

    Vallance, S A; Entwistle, R C; Hitchens, P L; Gardner, I A; Stover, S M

    2013-05-01

    Identification of exercise history patterns that are related to catastrophic scapular fracture will facilitate prevention of racehorse fatalities. To determine if exercise patterns are associated with scapular fracture in Thoroughbred (TB) and Quarter Horse (QH) racehorses. High-speed exercise histories for 65 TB and 26 QH racehorses that had a complete scapular fracture (cases) and 2 matched control racehorses were retrospectively studied. Exercise variables were created from lifetime race and official timed workout reports. Associations between exercise variables and scapular fracture were investigated using conditional logistic regression. Thoroughbreds with a scapular fracture had a greater number of workouts, events (combined works and races), and mean event distances than QHs with a scapular fracture. Quarter Horses worked less frequently and accumulated distance at a lower rate than TBs. Breed differences were not found for career race number or length, time between races or lay-up variables for horses with ≥1 lay-up. For both breeds, cases had fewer events, lower recent accumulated distance and fewer active days in training than controls; however, a subset of TB cases with >10 events since lay-up had a longer active career than controls. For QHs that had a lay-up, total and mean lay-up times were greater for cases than controls. Multivariable models revealed that odds ratios (OR) of scapular fracture were greater for TBs that had not yet raced (OR = 23.19; 95% confidence interval (CI) 3.03-177.38) and lower for QHs with more events (OR = 0.71; 95% CI 0.54-0.94). Racehorses that are in early high-speed training but behind that of their training cohort should be examined for signs of scapular stress remodelling. Quarter Horses that had a prolonged lay-up and TBs that have endured high-speed training for a longer duration than that of their training cohort also were at greater risk. © 2012 EVJ Ltd.

  6. Design of a hybrid command and control mobile botnet: Presentation

    CSIR Research Space (South Africa)

    Pieterse, H

    2013-03-01

    Full Text Available smartphones controlled by a botmaster through a command and control network to serve a malicious purpose. This study presents the design of a hybrid command and control mobile botnet. It describes the propagation vectors, command and control channels...

  7. Designing agricultural landscapes for natural pest control

    NARCIS (Netherlands)

    Steingrover, E.G.; Geertsema, W.; Wingerden, van W.K.R.E.

    2010-01-01

    The green–blue network of semi-natural non-crop landscape elements in agricultural landscapes has the potential to enhance natural pest control by providing various resources for the survival of beneficial insects that suppress crop pests. A study was done in the Hoeksche Waard to explore how

  8. Control Design for a Generic Commercial Aircraft Engine

    Science.gov (United States)

    Csank, Jeffrey; May, Ryan D.

    2010-01-01

    This paper describes the control algorithms and control design process for a generic commercial aircraft engine simulation of a 40,000 lb thrust class, two spool, high bypass ratio turbofan engine. The aircraft engine is a complex nonlinear system designed to operate over an extreme range of environmental conditions, at temperatures from approximately -60 to 120+ F, and at altitudes from below sea level to 40,000 ft, posing multiple control design constraints. The objective of this paper is to provide the reader an overview of the control design process, design considerations, and justifications as to why the particular architecture and limits have been chosen. The controller architecture contains a gain-scheduled Proportional Integral controller along with logic to protect the aircraft engine from exceeding any limits. Simulation results illustrate that the closed loop system meets the Federal Aviation Administration s thrust response requirements

  9. Tight intra-operative blood pressure control versus standard care for patients undergoing hip fracture repair - Hip Fracture Intervention Study for Prevention of Hypotension (HIP-HOP) trial: study protocol for a randomised controlled trial.

    Science.gov (United States)

    Moppett, Iain Keith; White, Stuart; Griffiths, Richard; Buggy, Donal

    2017-07-25

    Hypotension during anaesthesia for hip fracture surgery is common. Recent data suggest that there is an association between the lowest intra-operative blood pressure and mortality, even when adjusted for co-morbidities. This is consistent with data derived from the wider surgical population, where magnitude and duration of hypotension are associated with mortality and peri-operative complications. However, there are no trial to data to support more aggressive blood pressure control. We are conducting a three-centre, randomised, double-blinded pilot study in three hospitals in the United Kingdom. The sample size will be 75 patients (25 from each centre). Randomisation will be done using computer-generated concealed tables. Both participants and investigators will be blinded to group allocation. Participants will be aged >70 years, cognitively intact (Abbreviated Mental Test Score 7 or greater), able to give informed consent and admitted directly through the emergency department with a fractured neck of the femur requiring operative repair. Patients randomised to tight blood pressure control or avoidance of intra-operative hypotension will receive active treatment as required to maintain both of the following: systolic arterial blood pressure >80% of baseline pre-operative value and mean arterial pressure >75 mmHg throughout. All participants will receive standard hospital care, including spinal or general anaesthesia, at the discretion of the clinical team. The primary outcome is a composite of the presence or absence of defined cardiovascular, renal and delirium morbidity within 7 days of surgery (myocardial injury, stroke, acute kidney injury, delirium). Secondary endpoints will include the defined individual morbidities, mortality, early mobility and discharge to usual residence. This is a small-scale pilot study investigating the feasibility of a trial of tight intra-operative blood pressure control in a frail elderly patient group with known high morbidity

  10. Design Of Combined Stochastic Feedforward/Feedback Control

    Science.gov (United States)

    Halyo, Nesim

    1989-01-01

    Methodology accommodates variety of control structures and design techniques. In methodology for combined stochastic feedforward/feedback control, main objectives of feedforward and feedback control laws seen clearly. Inclusion of error-integral feedback, dynamic compensation, rate-command control structure, and like integral element of methodology. Another advantage of methodology flexibility to develop variety of techniques for design of feedback control with arbitrary structures to obtain feedback controller: includes stochastic output feedback, multiconfiguration control, decentralized control, or frequency and classical control methods. Control modes of system include capture and tracking of localizer and glideslope, crab, decrab, and flare. By use of recommended incremental implementation, control laws simulated on digital computer and connected with nonlinear digital simulation of aircraft and its systems.

  11. Designing a sustainable strategy for malaria control?

    Directory of Open Access Journals (Sweden)

    Mharakurwa Sungano

    2011-08-01

    Full Text Available Abstract Malaria in the 21st century is showing signs of declining over much of its distribution, including several countries in Africa where previously this was not thought to be feasible. Yet for the most part the strategies to attack the infection are similar to those of the 1950s. Three major Journals have recently drawn attention to the situation, stressing the importance of research, describing the successes and defining semantics related to control. But there is a need to stress the importance of local sustainability, and consider somewhat urgently how individual endemic countries can plan and implement the programmes that are currently financed, for the most part, by donor institutions. On an immediate basis research should be more focused on a data driven approach to control. This will entail new thinking on the role of local infrastructure and in training of local scientists in local universities in epidemiology and field malariology so that expanded control programmes can become operational. Donor agencies should encourage and facilitate development of career opportunities for such personnel so that local expertise is available to contribute appropriately.

  12. Design and Analysis of Morpheus Lander Flight Control System

    Science.gov (United States)

    Jang, Jiann-Woei; Yang, Lee; Fritz, Mathew; Nguyen, Louis H.; Johnson, Wyatt R.; Hart, Jeremy J.

    2014-01-01

    The Morpheus Lander is a vertical takeoff and landing test bed vehicle developed to demonstrate the system performance of the Guidance, Navigation and Control (GN&C) system capability for the integrated autonomous landing and hazard avoidance system hardware and software. The Morpheus flight control system design must be robust to various mission profiles. This paper presents a design methodology for employing numerical optimization to develop the Morpheus flight control system. The design objectives include attitude tracking accuracy and robust stability with respect to rigid body dynamics and propellant slosh. Under the assumption that the Morpheus time-varying dynamics and control system can be frozen over a short period of time, the flight controllers are designed to stabilize all selected frozen-time control systems in the presence of parametric uncertainty. Both control gains in the inner attitude control loop and guidance gains in the outer position control loop are designed to maximize the vehicle performance while ensuring robustness. The flight control system designs provided herein have been demonstrated to provide stable control systems in both Draper Ares Stability Analysis Tool (ASAT) and the NASA/JSC Trick-based Morpheus time domain simulation.

  13. Relational databases for SSC design and control

    International Nuclear Information System (INIS)

    Barr, E.; Peggs, S.; Saltmarsh, C.

    1989-01-01

    Most people agree that a database is A Good Thing, but there is much confusion in the jargon used, and in what jobs a database management system and its peripheral software can and cannot do. During the life cycle of an enormous project like the SSC, from conceptual and theoretical design, through research and development, to construction, commissioning and operation, an enormous amount of data will be generated. Some of these data, originating in the early parts of the project, will be needed during commissioning or operation, many years in the future. Two of these pressing data management needs-from the magnet research and industrialization programs and the lattice design-have prompted work on understanding and adapting commercial database practices for scientific projects. Modern relational database management systems (rDBMS's) cope naturally with a large proportion of the requirements of data structures, like the SSC database structure built for the superconduction cable supplies, uses, and properties. This application is similar to the commercial applications for which these database systems were developed. The SSC application has further requirements not immediately satisfied by the commercial systems. These derive from the diversity of the data structures to be managed, the changing emphases and uses during the project lifetime, and the large amount of scientific data processing to be expected. 4 refs., 5 figs

  14. Research and field tests of staged fracturing technology for casing deformation sections in horizontal shale gas wells

    Directory of Open Access Journals (Sweden)

    Shimeng Liao

    2018-02-01

    Full Text Available Horizontal shale gas well fracturing is mostly carried out by pumping bridge plugs. In the case of casing deformation, the bridge plug can not be pumped down to the designated position, so the hole sections below the deformation could not be stimulated according to the design program. About 30% of horizontal shale gas wells in the Changning and Weiyuan Blocks, Sichuan Basin, suffer various casing deformation after fracturing. Previously, the hole sections which could not be stimulated due to casing deformation were generally abandoned. As a result, the resources controlled by shale gas wells weren't exploited effectively and the fracturing effect was impacted greatly. There are a lot of difficulties in investigating casing deformation, such as complex mechanisms, various influencing factors and unpredictable deformation time. Therefore, it is especially important to seek a staged fracturing technology suitable for the casing deformation sections. In this paper, the staged fracturing technology with sand plugs inside fractures and the staged fracturing technology with temporary plugging balls were tested in casing deformation wells. The staged fracturing technology with sand plugs inside fractures was carried out in the mode of single-stage perforation and single-stage fracturing. The staged fracturing technology with temporary plugging balls was conducted in the mode of single perforation, continuous fracturing and staged ball dropping. Then, two kinds of technologies were compared in terms of their advantages and disadvantages. Finally, they were tested on site. According to the pressure response, the pressure monitoring of the adjacent wells and the microseismic monitoring in the process of actual fracturing, both technologies are effective in the stimulation of the casing deformation sections, realizing well control reserves efficiently and guaranteeing fracturing effects. Keywords: Shale gas, Horizontal well, Casing deformation, Staged

  15. Fixed-Order Mixed Norm Designs for Building Vibration Control

    Science.gov (United States)

    Whorton, Mark S.; Calise, Anthony J.

    2000-01-01

    This study investigates the use of H2, mu-synthesis, and mixed H2/mu methods to construct full order controllers and optimized controllers of fixed dimensions. The benchmark problem definition is first extended to include uncertainty within the controller bandwidth in the form of parametric uncertainty representative of uncertainty in the natural frequencies of the design model. The sensitivity of H2 design to unmodeled dynamics and parametric uncertainty is evaluated for a range of controller levels of authority. Next, mu-synthesis methods are applied to design full order compensators that are robust to both unmodeled dynamics and to parametric uncertainty. Finally, a set of mixed H2/mu compensators are designed which are optimized for a fixed compensator dimension. These mixed norm designs recover the H2 design performance levels while providing the same levels of robust stability as the mu designs. It is shown that designing with the mixed norm approach permits higher levels of controller authority for which the H2 designs are destabilizing. The benchmark problem is that of an active tendon system. The controller designs are all based on the use of acceleration feedback.

  16. Non-fragile multivariable PID controller design via system augmentation

    Science.gov (United States)

    Liu, Jinrong; Lam, James; Shen, Mouquan; Shu, Zhan

    2017-07-01

    In this paper, the issue of designing non-fragile H∞ multivariable proportional-integral-derivative (PID) controllers with derivative filters is investigated. In order to obtain the controller gains, the original system is associated with an extended system such that the PID controller design can be formulated as a static output-feedback control problem. By taking the system augmentation approach, the conditions with slack matrices for solving the non-fragile H∞ multivariable PID controller gains are established. Based on the results, linear matrix inequality -based iterative algorithms are provided to compute the controller gains. Simulations are conducted to verify the effectiveness of the proposed approaches.

  17. Controlling and tracking hyperchaotic Roessler system via active backstepping design

    International Nuclear Information System (INIS)

    Zhang Hao; Ma Xikui; Li Ming; Zou Jianlong

    2005-01-01

    This paper presents a novel active backstepping control approach for controlling hyperchaotic Roessler system to a steady state as well as tracking of any desire trajectory to be achieved in a systematic way. The proposed method is a systematic design approach and consists in a recursive procedure that interlaces the choice of a Lyapunov function with the design of active control. Numerical results show that the controller is singularity free and the closed-loop system is stable globally. Especially, the main feature of this technique is that it gives the flexibility to construct a control law. Finally, numerical experiments verify the feasibility and effectiveness of the proposed control technique

  18. Experimentally supported control design for a direct drive robot

    NARCIS (Netherlands)

    Kostic, D.; Jager, de A.G.; Steinbuch, M.

    2002-01-01

    We promote the idea of an experimentally supported control design as a successful way to achieve accurate tracking of reference robot motions, under disturbance conditions and given the uncertainties arising from modeling errors. The Hinf robust control theory is used for design of motion

  19. Design and control considerations for industrial and space manipulators

    Science.gov (United States)

    Whitney, D. E.; Book, W. J.; Lynch, P. M.

    1974-01-01

    This paper is a progress report summarizing theoretical and practical results concerning integration of design and control aspects of manipulator arms for industrial or space applications. The relationships between task specifications, gross motions, fine motions, actuator type and location, size and strength of structural members, control servos and strategies, and overall design evaluation are briefly discussed, with some technical examples.

  20. CANDIDATE GENE ANALYSIS IN ISRAELI SOLDIERS WITH STRESS FRACTURES

    Directory of Open Access Journals (Sweden)

    Ran Yanovich

    2012-03-01

    Full Text Available To investigate the association of polymorphisms within candidate genes which we hypothesized may contribute to stress fracture predisposition, a case-control, cross- sectional study design was employed. Genotyping 268 Single Nucleotide Polymorphisms- SNPs within 17 genes in 385 Israeli young male and female recruits (182 with and 203 without stress fractures. Twenty-five polymorphisms within 9 genes (NR3C1, ANKH, VDR, ROR2, CALCR, IL6, COL1A2, CBG, and LRP4 showed statistically significant differences (p < 0.05 in the distribution between stress fracture cases and non stress fracture controls. Seventeen genetic variants were associated with an increased stress fracture risk, and eight variants with a decreased stress fracture risk. None of the SNP associations remained significant after correcting for multiple comparisons (false discovery rate- FDR. Our findings suggest that genes may be involved in stress fracture pathogenesis. Specifically, the CALCR and the VDR genes are intriguing candidates. The putative involvement of these genes in stress fracture predisposition requires analysis of more cases and controls and sequencing the relevant genomic regions, in order to define the specific gene mutations

  1. Review of FFTF and CRBRP control rod systems designs

    International Nuclear Information System (INIS)

    Pitterle, T.A.; Lagally, H.O.

    1977-01-01

    The evolution of the primary control rod system design for FFTF and CRBR, beginning with the initial choice of the basic concepts, is described. The significant component and systems tests are reviewed together with the test results which referenced the development of the CRBR primary control rod system design. Modifications to the concepts and detail designs of the FFTF control rod system were required principally to satisfy the requirements of CRBR, and at the same time incorporating design refinements shown desirable by the tests

  2. Low-density lipoprotein cholesterol is associated with fracture risk in diabetes patients - a nested case-control study

    DEFF Research Database (Denmark)

    Starup-Linde, Jakob; Gregersen, Søren; Vestergaard, Peter

    2014-01-01

    available for an analysis of patient characteristics, co-morbidities, biochemical parameters and drug usage. Results: Patient age at the time of diabetes diagnosis, a diagnosis of previous fracture, an alcohol related diagnosis, total cholesterol level, and the usage of antidepressants, antiepileptics...... and insulin all increased the odds of fracture. Low-density lipoprotein cholesterol (LDL) levels decreased the odds of fracture, where the level of 3.04-5.96 mmol/l was optimal with regard to fracture risk. Conclusion: LDL may add to the understanding of fractures in diabetes patients and it may be added...

  3. A Design of a Hybrid Non-Linear Control Algorithm

    Directory of Open Access Journals (Sweden)

    Farinaz Behrooz

    2017-11-01

    Full Text Available One of the high energy consuming devices in the buildings is the air-conditioning system. Designing a proper controller to consider the thermal comfort and simultaneously control the energy usage of the device will impact on the system energy efficiency and its performance. The aim of this study was to design a Multiple-Input and Multiple-Output (MIMO, non-linear, and intelligent controller on direct expansion air-conditioning system The control algorithm uses the Fuzzy Cognitive Map method as a main controller and the Generalized Predictive Control method is used for assigning the initial weights of the main controller. The results of the proposed controller shows that the controller was successfully designed and works in set point tracking and under disturbance rejection tests. The obtained results of the Generalized Predictive Control-Fuzzy Cognitive Map controller are compared with the previous MIMO Linear Quadratic Gaussian control design on the same direct expansion air-conditioning system under the same conditions. The comparative results indicate energy savings would be achieved with the proposed controller with long-term usage. Energy efficiency and thermal comfort conditions are achieved by the proposed controller.

  4. Electromagnetic design calculation of the control rod drive mechanism

    International Nuclear Information System (INIS)

    Zhu Qirong; Zhu Jingchang

    1991-01-01

    Electromagnetic design calculation of the step-by-step magnetic jacking control rod drive mechanism includes magnetic field force calculation and design calculation of magnetomotive force for three electromagnetic iron and their coilds. The basic principle and method of electromagnetic design calculation had been expounded to take the lift magnet and lift coil for example

  5. The Application of Layer Theory to Design: The Control Layer

    Science.gov (United States)

    Gibbons, Andrew S.; Langton, Matthew B.

    2016-01-01

    A theory of design layers proposed by Gibbons ("An Architectural Approach to Instructional Design." Routledge, New York, 2014) asserts that each layer of an instructional design is related to a body of theory closely associated with the concerns of that particular layer. This study focuses on one layer, the control layer, examining…

  6. Should we attempt global (inlet engine airframe) control design?

    Science.gov (United States)

    Carlin, C. M.

    1980-01-01

    The feasibility of multivariable design of the entire airplane control system is briefly addressed. An intermediate step in that direction is to design a control for an inlet engine augmentor system by using multivariable techniques. The supersonic cruise large scale inlet research program is described which will provide an opportunity to develop, integrate, and wind tunnel test a control for a mixed compression inlet and variable cycle engine. The integrated propulsion airframe control program is also discussed which will introduce the problem of implementing MVC within a distributed processing avionics architecture, requiring real time decomposition of the global design into independent modules in response to hardware communication failures.

  7. Statistics and thermodynamics of fracture

    Science.gov (United States)

    Chudnovsky, A.

    1984-01-01

    A probabilistic model of the fracture processes unifying the phenomenological study of long term strength of materials, fracture mechanics and statistical approaches to fracture is briefly outlined. The general framework of irreversible thermodynamics is employed to model the deterministic side of the failure phenomenon. The stochastic calculus is used to account for thg failure mechanisms controlled by chance; particularly, the random roughness of fracture surfaces.

  8. Responsibilities for control room design in the USA

    International Nuclear Information System (INIS)

    Leary, J.E.; Barnhart, C.G.

    1980-01-01

    In the design and construction of nuclear power plants in the United States, the architect-engineering firm usually serves as the principal co-ordinator for the various parties involved. Recent events such as the Three Mile Island accident have focused attention on operability and human factors engineering in the design of the control room. This article describes current trends in control room design and the division of responsibility between the plant owner, the reactor vendor, and the architect-engineer. (author)

  9. Code Development for Control Design Applications: Phase I: Structural Modeling

    International Nuclear Information System (INIS)

    Bir, G. S.; Robinson, M.

    1998-01-01

    The design of integrated controls for a complex system like a wind turbine relies on a system model in an explicit format, e.g., state-space format. Current wind turbine codes focus on turbine simulation and not on system characterization, which is desired for controls design as well as applications like operating turbine model analysis, optimal design, and aeroelastic stability analysis. This paper reviews structural modeling that comprises three major steps: formation of component equations, assembly into system equations, and linearization

  10. Control system design for nano-positioning using piezoelectric actuators

    International Nuclear Information System (INIS)

    Shan, Jinjun; Liu, Yanfang; Cui, Naigang; Gabbert, Ulrich

    2016-01-01

    This paper presents a systematic control system design for nano-positioning of a piezoelectric actuator (PEA). PEAs exhibit hysteresis nonlinearity, which can dramatically limit the application and performance of linear feedback control theory. Thus the hysteresis is compensated for based on the Maxwell resistive capacitor (MRC) model first. Then a proportional plus integral (PI) controller and a proportional double integral plus lead compensation (PII and L) controller are designed for the hysteresis-compensated PEA to account for model uncertainty, disturbance, and noise. The robust stability of both controllers is proved. The effectiveness of the proposed control scheme is demonstrated experimentally. Both controllers achieve fast precise positioning. The 2% settling times for the PI controller and the PII and L controller are 1.5 ms and 4.7 ms, respectively. The positioning resolution is upto 1 nm for both controllers. (paper)

  11. Clinical benefits of oral nutritional supplementation for elderly hip fracture patients: a single blind randomised controlled trial.

    Science.gov (United States)

    Myint, Ma Wai Wai; Wu, Jenny; Wong, Euann; Chan, Suk Ping; To, Tze Shing Jess; Chau, Mei Wa Rosanna; Ting, Kwai Hing; Fung, Pui Man; Au, Kit Sing Derrick

    2013-01-01

    malnutrition is an important risk factor for poor outcome in patients recovering after hip fracture surgery. This study aimed to investigate the clinical, nutritional and rehabilitation effects of an oral nutritional supplementation (ONS) in an inpatient rehabilitation setting. this was an observer-blinded randomised controlled trial of elderly post-surgical proximal femoral fracture patients. A ready-to-use oral liquid nutritional supplementation (18-24 g protein and 500 kcal per day) in addition to hospital diet was compared with hospital diet only. Both groups received usual rehabilitation therapy and oral calcium and vitamin D supplements. Outcomes were compared at discharge from rehabilitation and after 4 weeks of discharge. The primary outcome parameters were the serum albumin level, the body mass index (BMI), the functional independence measure (FIM) and the elderly mobility scale (EMS). Secondary outcome parameters were frequency of complications, inpatient length of stay, mortality and acute hospital use within 6 months after discharge. a total of 126 patients were recruited, 65 in the supplementation arm and 61 in the control arm. There was a significant difference in change in BMI with a decrease of 0.25 and 0.03 kg/m(2) in the ONS group and 0.72 and 0.49 kg/m(2) in the control group at hospital discharge and follow-up, respectively (P = 0.012). The length of stay in rehabilitation ward was shortened by 3.80 (SE = 1.81, P = 0.04) days favouring the ONS group. The total number of infection episodes was also reduced significantly. No difference was observed in the rate of change of the serum albumin level, the FIM and the EMS. clinical and nutritional benefits were seen in this trial but rehabilitation benefits could not be demonstrated.

  12. Control Design of a Nonlinear Controller to Stabilize the Nonlinear ...

    African Journals Online (AJOL)

    inyangs

    protocol employed to combat the problem of proper queue utilization, busty packet drop and adaptable delay. TCP .... This case considers a delay on the control input only and the link capacity is made to be very large to ... We take the derivative of equation (13) with respect to t and apply the Leibniz integrator rule to obtain.

  13. Design of digital logic control for accelerator magnet power supply

    International Nuclear Information System (INIS)

    Long Fengli; Hu Wei; Cheng Jian

    2008-01-01

    For the accelerator magnet power supply, usually the Programmable Logic Controller (PLC) is used to server as the controller for logic protection and control. Along with the development of modern accelerator technology, it is a trend to use fully-digital control to the magnet power supply. It is possible to integrate the logic control part into the digital control component of the power supply, for example, the Field Programmable Gate Array (FPGA). The paper introduces to different methods which are designed for the logic protection and control for accelerator magnet power supplies with the FPGA as the control component. (authors)

  14. Design and development of virtual TXP control system software

    International Nuclear Information System (INIS)

    Wang Yunwei; Leng Shan; Liu Zhisheng; Wang Qiang; Shang Yanxia

    2008-01-01

    Taking distributed control system (DCS) of Siemens TELEPERM-XP (TXP) as the simulation object,Virtual TXP (VTXP) control system based on Virtual DCS with high fidelity and reliability was designed and developed on the platform of Windows. In the process of development, the method of object-oriented modeling and modularization program design are adopted, C++ language and technologies such as multithreading, ActiveX control, Socket network communication are used, to realize the wide range dynamic simulation and recreate the functions of the hardware and software of real TXP. This paper puts emphasis on the design and realization of Control server and Communication server. The development of Virtual TXP control system software is with great effect on the construction of simulation system and the design, commission, verification and maintenance of control system in large-scale power plants, nuclear power plants and combined cycle power plants. (authors)

  15. The System 80+ Standard Plant design control document. Volume 18

    International Nuclear Information System (INIS)

    1997-01-01

    This Design Control Document (DCD) is a repository of information comprising the System 80+trademark Standard Plant Design. The DCD also provides that design-related information to be incorporated by reference in the design certification rule for the System 80+ Standard Plant Design. Applicants for a combined license pursuant to 10 CFR 52 must ensure that the final Design Certification Rule and the associated Statements of Consideration are used when making all licensing decisions relevant to the System 80+ Standard Plant Design. The Design Control Document contains the DCD introduction, The Certified Design Material (CDM) [i.e., ''Tier 1''] and the Approved Design Material (ADM) [i.e., ''Tier 2''] for the System 80+ Standard Plant Design. The CDM includes the following sections: (1) Introductory material; (2) Certified Design Material for System 80+ systems and structures; (3) Certified Design Material for non-system-based aspects of the System 80+ Certified design; (4) Interface requirements; and (5) Site parameters. The ADM, to the extent applicable for the System 80+ Standard Plant Design, includes: (1) the information required for the final safety analysis report under 20 CFR 50.34; (2) other relevant information required by 10 CFR 52.47; and (3) emergency operations guidelines. This volume contains the following technical specifications of section 16 (Technical Specifications) of the ADM Design and Analysis: TS 3.3 Instrumentation; TS 3.4 Reactor Coolant System; TS 3.5 Emergency Core Cooling System; TS 3.6 Containment Systems; TS 3.7 Plant Systems; TS 3.8 Electrical Power Systems; TS 3.9 Refueling Operations; TS 4.0 Design Features; TS 5.0 Administrative Controls. Appendix 16 A Tech Spec Bases is also included. It contains the following: TS B2.0 Safety Limits Bases; TS B3.0 LCO Applicability Bases; TS B3.1 Reactivity Control Bases; TS B3.2 Power Distribution Bases

  16. Hydraulic fracture considerations in oil sand overburden dams

    Energy Technology Data Exchange (ETDEWEB)

    Cameron, R.; Madden, B.; Danku, M. [Syncrude Canada Ltd., Fort McMurray, AB (Canada)

    2008-07-01

    This paper discussed hydraulic fracture potential in the dry-filled temporary dams used in the oil sands industry. Hydraulic fractures can occur when reservoir fluid pressures are greater than the minimum stresses in a dam. Stress and strain conditions are influenced by pore pressures, levels of compaction in adjacent fills as well as by underlying pit floor and abutment conditions. Propagation pressure and crack initiation pressures must also be considered in order to provide improved hydraulic fracture protection to dams. Hydraulic fractures typically result in piping failures. Three cases of hydraulic fracture at oil sands operations in Alberta were presented. The study showed that hydraulic fracture failure modes must be considered in dam designs, particularly when thin compacted lift of dry fill are used to replace wetted clay cores. The risk of hydraulic fractures can be reduced by eliminating in situ bedrock irregularities and abutments. Overpressure heights, abutment sloping, and the sloping of fills above abutments, as well as the dam's width and base conditions must also be considered in relation to potential hydraulic fractures. It was concluded that upstream sand beaches and internal filters can help to prevent hydraulic fractures in dams in compacted control zones. 5 refs., 16 figs.

  17. Chemical optimization algorithm for fuzzy controller design

    CERN Document Server

    Astudillo, Leslie; Castillo, Oscar

    2014-01-01

    In this book, a novel optimization method inspired by a paradigm from nature is introduced. The chemical reactions are used as a paradigm to propose an optimization method that simulates these natural processes. The proposed algorithm is described in detail and then a set of typical complex benchmark functions is used to evaluate the performance of the algorithm. Simulation results show that the proposed optimization algorithm can outperform other methods in a set of benchmark functions. This chemical reaction optimization paradigm is also applied to solve the tracking problem for the dynamic model of a unicycle mobile robot by integrating a kinematic and a torque controller based on fuzzy logic theory. Computer simulations are presented confirming that this optimization paradigm is able to outperform other optimization techniques applied to this particular robot application

  18. Haystack Antenna Control System Design Document

    Science.gov (United States)

    2010-12-07

    of the pedestal and hexapod. Figure 18 shows an instance of the status/control window. The 1 eft s ide of t he w indow di splays t he current a...and 6 are disabled. The 1 eft r ight hand s ide of t he di splay s hows t he c urrent a nd d esired positions of t he Hexapod a ssembly in t wo di...LI t hen w ired i nto por t X 3 on t he B osch R exroth 18K W r egenerative power supply unit HMV01.1R-W0018-A-07-NNNN. Taps are spliced into the

  19. The human factors specialist in nuclear control centre design

    International Nuclear Information System (INIS)

    Wilson, R.B.; Beattie, J.D.

    The main focus at Ontario Hydro for man-machine interface design is in the design of control centres. Because the control of a nuclear generating unit is highly centralized there is an increasing need for effective information display and control layout. Control panel design innovations such as the use of CRT displays and the extended use of computerized control in the Darlington station have made it possible for Ontario Hydro to continue to have one first operator for each generating unit. The human factors specialist involved in control panel design must deal with people who know much more about the specific systems being controlled, and must become a generalist in all these systems as well. Designers have to use conceptual techniques such as task analysis, systems design, panel mock-ups, anthropometric data, and personal judgement based on experience as they design panels. They must find a balance between becoming locked into existing technology and methods, slavishly following the latest technological trends, and forgetting that real people will be using what they design

  20. Review on design and control aspects of ankle rehabilitation robots.

    Science.gov (United States)

    Jamwal, Prashant K; Hussain, Shahid; Xie, Sheng Q

    2015-03-01

    Ankle rehabilitation robots can play an important role in improving outcomes of the rehabilitation treatment by assisting therapists and patients in number of ways. Consequently, few robot designs have been proposed by researchers which fall under either of the two categories, namely, wearable robots or platform-based robots. This paper presents a review of both kinds of ankle robots along with a brief analysis of their design, actuation and control approaches. While reviewing these designs it was observed that most of them are undesirably inspired by industrial robot designs. Taking note of the design concerns of current ankle robots, few improvements in the ankle robot designs have also been suggested. Conventional position control or force control approaches, being used in the existing ankle robots, have been reviewed. Apparently, opportunities of improvement also exist in the actuation as well as control of ankle robots. Subsequently, a discussion on most recent research in the development of novel actuators and advanced controllers based on appropriate physical and cognitive human-robot interaction has also been included in this review. Implications for Rehabilitation Ankle joint functions are restricted/impaired as a consequence of stroke or injury during sports or otherwise. Robots can help in reinstating functions faster and can also work as tool for recording rehabilitation data useful for further analysis. Evolution of ankle robots with respect to their design and control aspects has been discussed in the present paper and a novel design with futuristic control approach has been proposed.

  1. Automatic Design of a Maglev Controller in State Space

    Science.gov (United States)

    1991-12-01

    Design of a Maglev Controller in State Space Feng Zhao Richard Thornton Abstract We describe the automatic synthesis of a global nonlinear controller for...the global switching points of the controller is presented. The synthesized control system can stabilize the maglev vehicle with large initial displace...NUMBERS Automation Desing of a Maglev Controller in State Space N00014-89-J-3202 MIP-9001651 6. AUTHOR(S) Feng Zhao and Richard Thornton 7. PERFORMING

  2. Mathematical and computational analyses of cracking formation fracture morphology and its evolution in engineering materials and structures

    CERN Document Server

    Sumi, Yoichi

    2014-01-01

    This book is about the pattern formation and the evolution of crack propagation in engineering materials and structures, bridging mathematical analyses of cracks based on singular integral equations, to computational simulation of engineering design. The first two parts of this book focus on elasticity and fracture and provide the basis for discussions on fracture morphology and its numerical simulation, which may lead to a simulation-based fracture control in engineering structures. Several design concepts are discussed for the prevention of fatigue and fracture in engineering structures, including safe-life design, fail-safe design, damage tolerant design. After starting with basic elasticity and fracture theories in parts one and two, this book focuses on the fracture morphology that develops due to the propagation of brittle cracks or fatigue cracks.   In part three, the mathematical analysis of a curved crack is precisely described, based on the perturbation method. The stability theory of interactive ...

  3. Neural network application to aircraft control system design

    Science.gov (United States)

    Troudet, Terry; Garg, Sanjay; Merrill, Walter C.

    1991-01-01

    The feasibility of using artificial neural network as control systems for modern, complex aerospace vehicles is investigated via an example aircraft control design study. The problem considered is that of designing a controller for an integrated airframe/propulsion longitudinal dynamics model of a modern fighter aircraft to provide independent control of pitch rate and airspeed responses to pilot command inputs. An explicit model following controller using H infinity control design techniques is first designed to gain insight into the control problem as well as to provide a baseline for evaluation of the neurocontroller. Using the model of the desired dynamics as a command generator, a multilayer feedforward neural network is trained to control the vehicle model within the physical limitations of the actuator dynamics. This is achieved by minimizing an objective function which is a weighted sum of tracking errors and control input commands and rates. To gain insight in the neurocontrol, linearized representations of the nonlinear neurocontroller are analyzed along a commanded trajectory. Linear robustness analysis tools are then applied to the linearized neurocontroller models and to the baseline H infinity based controller. Future areas of research identified to enhance the practical applicability of neural networks to flight control design.

  4. Neural network application to aircraft control system design

    Science.gov (United States)

    Troudet, Terry; Garg, Sanjay; Merrill, Walter C.

    1991-01-01

    The feasibility of using artificial neural networks as control systems for modern, complex aerospace vehicles is investigated via an example aircraft control design study. The problem considered is that of designing a controller for an integrated airframe/propulsion longitudinal dynamics model of a modern fighter aircraft to provide independent control of pitch rate and airspeed responses to pilot command inputs. An explicit model following controller using H infinity control design techniques is first designed to gain insight into the control problem as well as to provide a baseline for evaluation of the neurocontroller. Using the model of the desired dynamics as a command generator, a multilayer feedforward neural network is trained to control the vehicle model within the physical limitations of the actuator dynamics. This is achieved by minimizing an objective function which is a weighted sum of tracking errors and control input commands and rates. To gain insight in the neurocontrol, linearized representations of the nonlinear neurocontroller are analyzed along a commanded trajectory. Linear robustness analysis tools are then applied to the linearized neurocontroller models and to the baseline H infinity based controller. Future areas of research are identified to enhance the practical applicability of neural networks to flight control design.

  5. Integrated structure/control design - Present methodology and future opportunities

    Science.gov (United States)

    Weisshaar, T. A.; Newsom, J. R.; Zeiler, T. A.; Gilbert, M. G.

    1986-01-01

    Attention is given to current methodology applied to the integration of the optimal design process for structures and controls. Multilevel linear decomposition techniques proved to be most effective in organizing the computational efforts necessary for ISCD (integrated structures and control design) tasks. With the development of large orbiting space structures and actively controlled, high performance aircraft, there will be more situations in which this concept can be applied.

  6. Analysis and design of a nuclear boiler control scheme

    International Nuclear Information System (INIS)

    Hughes, F.M.

    1982-01-01

    The steam raising plant of a British designed nuclear power station for which the installed control scheme has given rise to performance and stability problems is considered. The lecture is based on studies carried out for the plant which illustrate the way in which multivariable frequency response methods can be used to analyse and identify the source of control problems and further enable alternative control schemes, having improved performance, to be designed. (author)

  7. Fully probabilistic control design in an adaptive critic framework

    Czech Academy of Sciences Publication Activity Database

    Herzallah, R.; Kárný, Miroslav

    2011-01-01

    Roč. 24, č. 10 (2011), s. 1128-1135 ISSN 0893-6080 R&D Projects: GA ČR GA102/08/0567 Institutional research plan: CEZ:AV0Z10750506 Keywords : Stochastic control design * Fully probabilistic design * Adaptive control * Adaptive critic Subject RIV: BC - Control Systems Theory Impact factor: 2.182, year: 2011 http://library.utia.cas.cz/separaty/2011/AS/karny-0364820.pdf

  8. Feedback Control Design for a Walking Athlete Robot

    Directory of Open Access Journals (Sweden)

    Xuan Vu Trien Nguyen

    2017-06-01

    Full Text Available In the paper, authors generalized the dynamic model of an athlete robot with elastic legs through Lagrange method. Then, a feed-back controller was designed to control the robot through a step-walking. The research just focused on stance phase – the period that robot just touched one leg on the ground. The simulation results showed that system worked well with the designed controller.

  9. Conceptual design for the NSTX Central Instrumentation and Control System

    International Nuclear Information System (INIS)

    Bashore, D.; Oliaro, G.; Roney, P.; Sichta, P.; Tindall, K.

    1997-01-01

    The design and construction phase for the National Spherical Torus Experiment (NSTX) is under way at the Princeton Plasma Physics Laboratory (PPPL). Operation is scheduled to begin on April 30, 1999. This paper describes the conceptual design for the NSTX Central Instrumentation and Control (I and C) System. Major elements of the Central I and C System include the Process Control System, Plasma Control System, Network System, Data Acquisition System, and Synchronization System to support the NSTX experimental device

  10. Robust Control Design for Uncertain Nonlinear Dynamic Systems

    Science.gov (United States)

    Kenny, Sean P.; Crespo, Luis G.; Andrews, Lindsey; Giesy, Daniel P.

    2012-01-01

    Robustness to parametric uncertainty is fundamental to successful control system design and as such it has been at the core of many design methods developed over the decades. Despite its prominence, most of the work on robust control design has focused on linear models and uncertainties that are non-probabilistic in nature. Recently, researchers have acknowledged this disparity and have been developing theory to address a broader class of uncertainties. This paper presents an experimental application of robust control design for a hybrid class of probabilistic and non-probabilistic parametric uncertainties. The experimental apparatus is based upon the classic inverted pendulum on a cart. The physical uncertainty is realized by a known additional lumped mass at an unknown location on the pendulum. This unknown location has the effect of substantially altering the nominal frequency and controllability of the nonlinear system, and in the limit has the capability to make the system neutrally stable and uncontrollable. Another uncertainty to be considered is a direct current motor parameter. The control design objective is to design a controller that satisfies stability, tracking error, control power, and transient behavior requirements for the largest range of parametric uncertainties. This paper presents an overview of the theory behind the robust control design methodology and the experimental results.

  11. The Automation Control System Design of Walking Beam Heating Furnace

    Directory of Open Access Journals (Sweden)

    Hong-Yu LIU

    2014-10-01

    Full Text Available Combining the transformation project of certain strip steel rolling production line, the techniques process of walking beam heating furnace was elaborated in this paper. The practical application of LOS-T18-2ZC1 laser detector was elaborated. The network communication model of walking beam heating furnace control system was designed. The realization method of production process automation control was elaborated. The entire automation control system allocation picture and PLC power distribution system picture of walking beam heating furnace were designed. Charge machine movement process was elaborated. Walking beam movement process was elaborated. Extractor movement process was elaborated. The hydraulic station of walking mechanism was elaborated. Relative control circuit diagram was designed. The control function of parallel shift motor, uplifted and degressive motor was elaborated. The control circuit diagram of parallel shift motor of charge machine and extractor of first heating furnace was designed. The control circuit diagram of uplifted and degressive motor of charge machine and extractor of first heating furnace was designed. The realization method of steel blank length test function was elaborated. The realization method of tracking and sequence control function of heating furnace field roller were elaborated. The design provides important reference base for enhancing walking beam heating furnace control level.

  12. Designing molecular structure to achieve ductile fracture behavior in a stiff and strong 2D polymer, "graphylene".

    Science.gov (United States)

    Sandoz-Rosado, E; Beaudet, T D; Balu, R; Wetzel, E D

    2016-06-07

    As the simplest two-dimensional (2D) polymer, graphene has immensely high intrinsic strength and elastic stiffness but has limited toughness due to brittle fracture. We use atomistic simulations to explore a new class of graphene/polyethylene hybrid 2D polymer, "graphylene", that exhibits ductile fracture mechanisms and has a higher fracture toughness and flaw tolerance than graphene. A specific configuration of this 2D polymer hybrid, denoted "GrE-2" for the two-carbon-long ethylene chains connecting benzene rings in the inherent framework, is prioritized for study. MD simulations of crack propagation show that the energy release rate to propagate a crack in GrE-2 is twice that of graphene. We also demonstrate that GrE-2 exhibits delocalized failure and other energy-dissipating fracture mechanisms such as crack branching and bridging. These results demonstrate that 2D polymers can be uniquely tailored to achieve a balance of fracture toughness with mechanical stiffness and strength.

  13. The System 80+ Standard Plant design control document. Volume 11

    International Nuclear Information System (INIS)

    1997-01-01

    This Design Control Document (DCD) is a repository of information comprising the System 80+trademark Standard Plant Design. The DCD also provides that design-related information to be incorporated by reference in the design certification rule for the System 80+ Standard Plant Design. Applicants for a combined license pursuant to 10 CFR 52 must ensure that the final Design Certification Rule and the associated Statements of Consideration are used when making all licensing decisions relevant to the System 80+ Standard Plant Design. The Design Control Document contains the DCD introduction, The Certified Design Material (CDM) [i.e., ''Tier 1''] and the Approved Design Material (ADM) [i.e., ''Tier 2''] for the System 80+ Standard Plant Design. The CDM includes the following sections: (1) Introductory material; (2) Certified Design Material for System 80+ systems and structures; (3) Certified Design Material for non-system-based aspects of the System 80+ Certified design; (4) Interface requirements; and (5) Site parameters. The ADM, to the extent applicable for the System 80+ Standard Plant Design, includes: (1) the information required for the final safety analysis report under 20 CFR 50.34; (2) other relevant information required by 10 CFR 52.47; and (3) emergency operations guidelines. This volume covers parts 6 and 7 and appendix 7A for section 7 (Instrumentation and Control) of the ADM Design and Analysis. The topics covered by these are: other systems required for safety; control systems not required by safety; and CMF evaluation of limiting faults. Parts 1--3 of section 8 (Electric Power) of the ADM are also included in this volume. Topics covered by these parts are: introduction; offsite power system; and onsite power system

  14. Design of viewing windows for controlled-atmosphere chambers

    International Nuclear Information System (INIS)

    Robinson, J.N.

    1980-03-01

    A guide to the design of safe viewing windows is presented. Design criteria, the properties of materials, the problems of structural design in unreliable materials such as glass, the mathematics of reliability and redundance, and problems associated with testing windows are discussed, and formulas are presented for the design of windows. Criteria adopted at ORNL for controlled-atmosphere chambers are presented, a program for surveying and upgrading the safety of existing facilities is described, and the results of this program are reported

  15. Design of control system based on SCM music fountain

    Science.gov (United States)

    Li, Biqing; Li, Zhao; Jiang, Suping

    2018-06-01

    The design of the design of a microprocessor controlled by simple circuit, introduced this design applied to the components, and draw the main flow chart presentation. System is the use of an external music source, the intensity of the input audio signal lights will affect the light off, the fountain spray of water level will be based on changes in the lantern light off. This design uses a single-chip system is simple, powerful, good reliability and low cost.

  16. Characterising rock fracture aperture-spacing relationships using power-law relationships: some considerations

    Science.gov (United States)

    Brook, Martin; Hebblewhite, Bruce; Mitra, Rudrajit

    2016-04-01

    The size-scaling of rock fractures is a well-studied problem in geology, especially for permeability quantification. The intensity of fractures may control the economic exploitation of fractured reservoirs because fracture intensity describes the abundance of fractures potentially available for fluid flow. Moreover, in geotechnical engineering, fractures are important for parameterisation of stress models and excavation design. As fracture data is often collected from widely-spaced boreholes where core recovery is often incomplete, accurate interpretation and representation of fracture aperture-frequency relationships from sparse datasets is important. Fracture intensity is the number of fractures encountered per unit length along a sample scanline oriented perpendicular to the fractures in a set. Cumulative frequency of fractures (F) is commonly related to fracture aperture (A) in the form of a power-law (F = aA-b), with variations in the size of the a coefficient between sites interpreted to equate to fracture frequency for a given aperture (A). However, a common flaw in this approach is that even a small change in b can have a large effect on the response of the fracture frequency (F) parameter. We compare fracture data from the Late Permian Rangal Coal Measures from Australia's Bowen Basin, with fracture data from Jurassic carbonates from the Sierra Madre Oriental, northeastern Mexico. Both power-law coefficient a and exponent b control the fracture aperture-frequency relationship in conjunction with each other; that is, power-laws with relatively low a coefficients have relatively high b exponents and vice versa. Hence, any comparison of different power-laws must take both a and b into consideration. The corollary is that different sedimentary beds in the Sierra Madre carbonates do not show ˜8× the fracture frequency for a given fracture aperture, as based solely on the comparison of coefficient a. Rather, power-law "sensitivity factors" developed from both

  17. Higher fish intake is associated with a lower risk of hip fractures in Chinese men and women: a matched case-control study.

    Science.gov (United States)

    Fan, Fan; Xue, Wen-Qiong; Wu, Bao-Hua; He, Ming-Guang; Xie, Hai-Li; Ouyang, Wei-Fu; Tu, Su-Lan; Chen, Yu-Ming

    2013-01-01

    Fish is rich in nutrients that are favorable to bone health, but limited data are available regarding the relationship between fish intake and hip fractures. Our study examined the association between habitual fish intake and risk of hip fractures. A case-control study was performed between June 2009 and June 2012 in Guangdong Province, China. Five hundred and eighty-one hip fracture incident cases, aged 55 to 80 years (mean: 71 years), were enrolled from four hospitals. 1∶1 matched controls by gender and age (±3 years) were also recruited from communities and hospitals. Face-to-face interviews were used to obtain habitual dietary intake and information on various covariates. Univariate conditional logistic regression analyses showed significantly dose-dependent inverse correlations between the risk of hip fractures and the intake of fresh-water fish, sea fish, mollusca, shellfish, and total fish in all of the subjects (p-trend: water fish (p = 0.553). The ORs (95%CI) of hip fractures for the highest (vs. lowest) quartile were 0.80 (0.48-1.31) for fresh-water fish, 0.31 (0.18-0.52) for sea fish, 0.55 (0.34-0.88) for mollusca and shellfish, and 0.47 (0.28-0.79) for total fish, respectively. Stratified and interaction analyses showed that the association was more significant in males than in females (p-interaction = 0.052). Higher intake of seafood is independently associated with lower risk of hip fractures in elderly Chinese. Increasing consumption of sea fish may benefit the prevention of hip fractures in this population.

  18. Does self-efficacy mediate functional change in older adults participating in an exercise program after hip fracture? A randomized controlled trial.

    Science.gov (United States)

    Chang, Feng-Hang; Latham, Nancy K; Ni, Pengsheng; Jette, Alan M

    2015-06-01

    To examine whether self-efficacy mediated the effect of the Home-based Post-Hip Fracture Rehabilitation program on activity limitations in older adults after hip fracture and whether the mediating effect was different between sex and age groups. Randomized controlled trial. Community. Participants with hip fracture (N=232; mean age ± SD, 79±9.4y) were randomly assigned to intervention (n=120, 51.7%) and attention control (n=112, 48.3%) groups. The 6-month intervention, the Home-based Post-Hip Fracture Rehabilitation, is a functionally oriented, home-based exercise program. Data were collected at baseline, postintervention (6mo), and follow-up (9mo). Activity Measure for Post-Acute Care. The mediating effect of the Home-based Post-Hip Fracture Rehabilitation program on Basic Mobility function through self-efficacy for exercise was significant at 9 months (βindirect=.21). Similarly, the mediating effect of the intervention on Daily Activity function through self-efficacy for exercise was significant at 9 months (βindirect=.49). In subgroup analyses, the mediating effect was significant at 9 months in the younger group (age, ≤79y) in comparison to the older group and was significant in women in comparison to men. Self-efficacy may play a partial mediating role in the effect on some longer-term functional outcomes in the Home-based Post-Hip Fracture Rehabilitation intervention. The results suggest that program components that target self-efficacy should be incorporated in future hip fracture rehabilitation interventions. Age and sex of the targeted participants may also need to be considered when developing interventions. Copyright © 2015 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  19. Higher fish intake is associated with a lower risk of hip fractures in Chinese men and women: a matched case-control study.

    Directory of Open Access Journals (Sweden)

    Fan Fan

    Full Text Available OBJECTIVES: Fish is rich in nutrients that are favorable to bone health, but limited data are available regarding the relationship between fish intake and hip fractures. Our study examined the association between habitual fish intake and risk of hip fractures. METHODS: A case-control study was performed between June 2009 and June 2012 in Guangdong Province, China. Five hundred and eighty-one hip fracture incident cases, aged 55 to 80 years (mean: 71 years, were enrolled from four hospitals. 1∶1 matched controls by gender and age (±3 years were also recruited from communities and hospitals. Face-to-face interviews were used to obtain habitual dietary intake and information on various covariates. RESULTS: Univariate conditional logistic regression analyses showed significantly dose-dependent inverse correlations between the risk of hip fractures and the intake of fresh-water fish, sea fish, mollusca, shellfish, and total fish in all of the subjects (p-trend: <0.001-0.016. After adjusting for covariates, the associations were slightly attenuated but remained significant for all (p-trend: <0.001-0.017 except for fresh-water fish (p = 0.553. The ORs (95%CI of hip fractures for the highest (vs. lowest quartile were 0.80 (0.48-1.31 for fresh-water fish, 0.31 (0.18-0.52 for sea fish, 0.55 (0.34-0.88 for mollusca and shellfish, and 0.47 (0.28-0.79 for total fish, respectively. Stratified and interaction analyses showed that the association was more significant in males than in females (p-interaction = 0.052. CONCLUSION: Higher intake of seafood is independently associated with lower risk of hip fractures in elderly Chinese. Increasing consumption of sea fish may benefit the prevention of hip fractures in this population.

  20. Guidelines for control room systems design. Working material. Report

    International Nuclear Information System (INIS)

    1993-01-01

    This report contains comprehensive technical and methodological information and recommendations for the benefit of Member States for advice and assistance in ''NPP control room systems'' design backfitting existing nuclear power plants and design for future stations. The term ''Control Room Systems'' refers to the entire human/machine interface for the nuclear stations - including the main control room, back-ups control room and the emergency control rooms, local panels, technical support centres, operating staff, operating procedures, operating training programs, communications, etc. Refs, figs and tabs

  1. New design deforming controlling system of the active stressed lap

    Science.gov (United States)

    Ying, Li; Wang, Daxing

    2008-07-01

    A 450mm diameter active stressed lap has been developed in NIAOT by 2003. We design a new lap in 2007. This paper puts on emphases on introducing the new deforming control system of the lap. Aiming at the control characteristic of the lap, a new kind of digital deforming controller is designed. The controller consists of 3 parts: computer signal disposing, motor driving and force sensor signal disposing. Intelligent numeral PID method is applied in the controller instead of traditional PID. In the end, the result of new deformation are given.

  2. Design of a PID Controller for a PCR Micro Reactor

    Science.gov (United States)

    Dinca, M. P.; Gheorghe, M.; Galvin, P.

    2009-01-01

    Proportional-integral-derivative (PID) controllers are widely used in process control, and consequently they are described in most of the textbooks on automatic control. However, rather than presenting the overall design process, the examples given in such textbooks are intended to illuminate specific focused aspects of selection, tuning and…

  3. Optimal Excitation Controller Design for Wind Turbine Generator

    Directory of Open Access Journals (Sweden)

    A. K. Boglou

    2011-01-01

    Full Text Available An optimal excitation controller design based on multirate-output controllers (MROCs having a multirate sampling mechanismwith different sampling period in each measured output of the system is presented. The proposed H∞ -control techniqueis applied to the discrete linear open-loop system model which represents a wind turbine generator supplying an infinite busthrough a transmission line.

  4. Design of Connectivity Preserving Flocking Using Control Lyapunov Function

    OpenAIRE

    Erfianto, Bayu; Bambang, Riyanto T.; Hindersah, Hilwadi; Muchtadi-Alamsyah, Intan

    2016-01-01

    This paper investigates cooperative flocking control design with connectivity preserving mechanism. During flocking, interagent distance is measured to determine communication topology of the flocks. Then, cooperative flocking motion is built based on cooperative artificial potential field with connectivity preserving mechanism to achieve the common flocking objective. The flocking control input is then obtained by deriving cooperative artificial potential field using control Lyapunov functio...

  5. Mechanical design and control of a new myoelectric hand prosthesis

    NARCIS (Netherlands)

    Peerdeman, B.; Stramigioli, Stefano; Hekman, Edsko E.G.; Brouwer, Dannis Michel; Misra, Sarthak

    2011-01-01

    The development of modern, myoelectrically controlled hand prostheses can be difficult, due to the many requirements its mechanical design and control system need to fulfill [1]. The hand should be controllable with few input signals, while being able to perform a wide range of motions. It should be

  6. Orthopaedic resident preparedness for closed reduction and pinning of pediatric supracondylar fractures is improved by e-learning: a multisite randomized controlled study.

    Science.gov (United States)

    Hearty, Thomas; Maizels, Max; Pring, Maya; Mazur, John; Liu, Raymond; Sarwark, John; Janicki, Joseph

    2013-09-04

    There is a need to provide more efficient surgical training methods for orthopaedic residents. E-learning could possibly increase resident surgical preparedness, confidence, and comfort for surgery. Using closed reduction and pinning of pediatric supracondylar humeral fractures as the index case, we hypothesized that e-learning could increase resident knowledge acquisition for case preparation in the operating room. An e-learning surgical training module was created on the Computer Enhanced Visual Learning platform. The module provides a detailed and focused road map of the procedure utilizing a multimedia format. A multisite prospective randomized controlled study design compared residents who used a textbook for case preparation (control group) with residents who used the same textbook plus completed the e-learning module (test group). All subjects completed a sixty-question test on the theory and methods of the case. After completion of the test, the control group then completed the module as well. All subjects were surveyed on their opinion regarding the effectiveness of the module after performing an actual surgical case. Twenty-eight subjects with no previous experience in this surgery were enrolled at four academic centers. Subjects were randomized into two equal groups. The test group scored significantly better (p < 0.001) and demonstrated competence on the test compared with the control group; the mean correct test score (and standard deviation) was 90.9% ± 6.8% for the test group and 73.5% ± 6.4% for the control group. All residents surveyed (n = 27) agreed that the module is a useful supplement to traditional methods for case preparation and twenty-two of twenty-seven residents agreed that it reduced their anxiety during the case and improved their attention to surgical detail. E-learning using the Computer Enhanced Visual Learning platform significantly improved preparedness, confidence, and comfort with percutaneous closed reduction and pinning of a

  7. Rib Fractures

    Science.gov (United States)

    ... Video) Achilles Tendon Tear Additional Content Medical News Rib Fractures By Thomas G. Weiser, MD, MPH, Associate Professor, ... Tamponade Hemothorax Injury to the Aorta Pulmonary Contusion Rib Fractures Tension Pneumothorax Traumatic Pneumothorax (See also Introduction to ...

  8. Root fractures

    DEFF Research Database (Denmark)

    Andreasen, Jens Ove; Christensen, Søren Steno Ahrensburg; Tsilingaridis, Georgios

    2012-01-01

    The purpose of this study was to analyze tooth loss after root fractures and to assess the influence of the type of healing and the location of the root fracture. Furthermore, the actual cause of tooth loss was analyzed....

  9. Thoracic paravertebral block versus intravenous patient-controlled analgesia for pain treatment in patients with multiple rib fractures.

    Science.gov (United States)

    Yeying, Ge; Liyong, Yuan; Yuebo, Chen; Yu, Zhang; Guangao, Ye; Weihu, Ma; Liujun, Zhao

    2017-12-01

    Objectives To assess the effect of thoracic paravertebral block (PVB) on pain management and preservation of pulmonary function compared with intravenous, patient-controlled analgesia (IVPCA) in patients with multiple rib fractures (MRFs). Methods Ninety patients with unilateral MRFs were included in this prospective study and randomly assigned to the TPVB or IVPCA group. The visual analogue scale (VAS) pain score, blood gas analysis, and bedside spirometry were measured and recorded at different time points after analgesia. Results TPVB and IVPCA provided good pain relief. VAS scores were significantly lower in the TPVB group than in the IVPCA group at rest and during coughing ( P pain relief and preservation of pulmonary function in patients with MRFs.

  10. Engineering Design of ITER Prototype Fast Plant System Controller

    Science.gov (United States)

    Goncalves, B.; Sousa, J.; Carvalho, B.; Rodrigues, A. P.; Correia, M.; Batista, A.; Vega, J.; Ruiz, M.; Lopez, J. M.; Rojo, R. Castro; Wallander, A.; Utzel, N.; Neto, A.; Alves, D.; Valcarcel, D.

    2011-08-01

    The ITER control, data access and communication (CODAC) design team identified the need for two types of plant systems. A slow control plant system is based on industrial automation technology with maximum sampling rates below 100 Hz, and a fast control plant system is based on embedded technology with higher sampling rates and more stringent real-time requirements than that required for slow controllers. The latter is applicable to diagnostics and plant systems in closed-control loops whose cycle times are below 1 ms. Fast controllers will be dedicated industrial controllers with the ability to supervise other fast and/or slow controllers, interface to actuators and sensors and, if necessary, high performance networks. Two prototypes of a fast plant system controller specialized for data acquisition and constrained by ITER technological choices are being built using two different form factors. This prototyping activity contributes to the Plant Control Design Handbook effort of standardization, specifically regarding fast controller characteristics. Envisaging a general purpose fast controller design, diagnostic use cases with specific requirements were analyzed and will be presented along with the interface with CODAC and sensors. The requirements and constraints that real-time plasma control imposes on the design were also taken into consideration. Functional specifications and technology neutral architecture, together with its implications on the engineering design, were considered. The detailed engineering design compliant with ITER standards was performed and will be discussed in detail. Emphasis will be given to the integration of the controller in the standard CODAC environment. Requirements for the EPICS IOC providing the interface to the outside world, the prototype decisions on form factor, real-time operating system, and high-performance networks will also be discussed, as well as the requirements for data streaming to CODAC for visualization and

  11. Design and Evaluation Methods for Underwater Control Systems

    Energy Technology Data Exchange (ETDEWEB)

    Chi, Lin

    1996-12-31

    This thesis on underwater control systems is written with the designer in mind, assuming that the reader has some knowledge of control theory. It can be used as a text for undergraduate students and engineers. To help readers better understand the system they will be working with, the thesis is organised in a stepwise way. The reader will gain basic knowledge about underwater operations, equipment and control systems. Then the reader will be able to follow the steps to develop a required control system for an underwater equipment by first understanding the characteristics of the design problem, customer requirement, functional requirement, and possible solution, and then to present a mathematical model of the control problem. Having developed the concept, the thesis guides the reader to develop evaluation criteria and different ways to make the decision. The thesis gives an overview of how to achieve a successful design rather than giving the techniques for detailed control system design. Chapter 1 describes underwater operations and systems. Chapter 2 discusses issues of underwater control systems and control methods. Chapter 3 deals with design method and control systems theory, focusing on human-centered control. Chapter 4 discusses methods used to evaluate and rank products, and chapter 5 applies the methods to an example. 113 refs., 115 figs., 80 tabs.

  12. Design and Evaluation Methods for Underwater Control Systems

    Energy Technology Data Exchange (ETDEWEB)

    Chi, Lin

    1997-12-31

    This thesis on underwater control systems is written with the designer in mind, assuming that the reader has some knowledge of control theory. It can be used as a text for undergraduate students and engineers. To help readers better understand the system they will be working with, the thesis is organised in a stepwise way. The reader will gain basic knowledge about underwater operations, equipment and control systems. Then the reader will be able to follow the steps to develop a required control system for an underwater equipment by first understanding the characteristics of the design problem, customer requirement, functional requirement, and possible solution, and then to present a mathematical model of the control problem. Having developed the concept, the thesis guides the reader to develop evaluation criteria and different ways to make the decision. The thesis gives an overview of how to achieve a successful design rather than giving the techniques for detailed control system design. Chapter 1 describes underwater operations and systems. Chapter 2 discusses issues of underwater control systems and control methods. Chapter 3 deals with design method and control systems theory, focusing on human-centered control. Chapter 4 discusses methods used to evaluate and rank products, and chapter 5 applies the methods to an example. 113 refs., 115 figs., 80 tabs.

  13. Design type testing for digital instrumentation and control systems

    International Nuclear Information System (INIS)

    Bastl, W.; Mohns, G.

    1997-01-01

    The design type qualification of digital safety instrumentation and control is outlined. Experience shows that the concepts discussed, derived from codes, guidelines and standards, achieve useful results. It has likewise become clear that the systematics of design type qualification of the hardware components is also applicable to the software components. Design type qualification of the software, a premiere, could be performed unexpectedly smoothly. The hardware design type qualification proved that the hardware as a substrate of functionality and reliability is an issue that demands full attention, as compared to conventional systems. Another insight is that design qualification of digital instrumentation and control systems must include plant-independent systems tests. Digital instrumentation and control systems simply work very differently from conventional control systems, so that this testing modality is inevitable. (Orig./CB) [de

  14. The System 80+ Standard Plant design control document. Volume 10

    International Nuclear Information System (INIS)

    1997-01-01

    This Design Control Document (DCD) is a repository of information comprising the System 80+trademark Standard Plant Design. The DCD also provides that design-related information to be incorporated by reference in the design certification rule for the System 80+ Standard Plant Design. Applicants for a combined license pursuant to 10 CFR 52 must ensure that the final Design Certification Rule and the associated Statements of Consideration are used when making all licensing decisions relevant to the System 80+ Standard Plant Design. The Design Control Document contains the DCD introduction, The Certified Design Material (CDM) [i.e., ''Tier 1''] and the Approved Design Material (ADM) [i.e., ''Tier 2''] for the System 80+ Standard Plant Design. The CDM includes the following sections: (1) Introductory material; (2) Certified Design Material for System 80+ systems and structures; (3) Certified Design Material for non-system-based aspects of the System 80+ Certified design; (4) Interface requirements; and (5) Site parameters. The ADM, to the extent applicable for the System 80+ Standard Plant Design, includes: (1) the information required for the final safety analysis report under 20 CFR 50.34; (2) other relevant information required by 10 CFR 52.47; and (3) emergency operations guidelines. This volume contains Appendices 6A, 6B, and 6C for section 6 (Engineered Safety Features) of the ADM Design and Analysis. Also, parts 1--5 of section 7 (Instrumentation and Control) of the ADM Design and Analysis are covered. The following information is covered in these parts: introduction; reactor protection system; ESF actuation system; system required for safe shutdown; and safety-related display instrumentation

  15. The System 80+ Standard Plant design control document. Volume 17

    International Nuclear Information System (INIS)

    1997-01-01

    This Design Control Document (DCD) is a repository of information comprising the System 80+trademark Standard Plant Design. The DCD also provides that design-related information to be incorporated by reference in the design certification rule for the System 80+ Standard Plant Design. Applicants for a combined license pursuant to 10 CFR 52 must ensure that the final Design Certification Rule and the associated Statements of Consideration are used when making all licensing decisions relevant to the System 80+ Standard Plant Design. The Design Control Document contains the DCD introduction, The Certified Design Material (CDM) [i.e., ''Tier 1''] and the Approved Design Material (ADM) [i.e., ''Tier 2''] for the System 80+ Standard Plant Design. The CDM includes the following sections: (1) Introductory material; (2) Certified Design Material for System 80+ systems and structures; (3) Certified Design Material for non-system-based aspects of the System 80+ Certified design; (4) Interface requirements; and (5) Site parameters. The ADM, to the extent applicable for the System 80+ Standard Plant Design, includes: (1) the information required for the final safety analysis report under 20 CFR 50.34; (2) other relevant information required by 10 CFR 52.47; and (3) emergency operations guidelines. This volume contains parts 2-7 and appendix 15A for section 15 (Accident Analysis) of the ADM Design and Analysis. Topics covered in these parts are: decrease in heat removal; decrease in RCS flow rate; power distribution anomalies; increase in RCS inventory; decrease in RCS inventory; release of radioactive materials. The appendix covers radiological release models. Also contained here are five technical specifications for section 16 (Technical Specifications) of the ADM Design and Analysis. They are: TS 1.0 Use and Applications; TS 2.0 Safety Limits; TS 3.0 LCO Availability; TS 3.1 Reactivity Control; and TS 3.2 Power Distribution

  16. Elevated temperature fracture mechanics

    International Nuclear Information System (INIS)

    Tomkins, B.

    1979-01-01

    The application of fracture mechanics concepts to cracks at elevated temperatures is examined. Particular consideration is given to the characterisation of crack tip stress-strain fields and parameters controlling crack extension under static and cyclic loads. (author)

  17. Comprehensive Geriatric Assessment for Prevention of Delirium After Hip Fracture: A Systematic Review of Randomized Controlled Trials.

    Science.gov (United States)

    Shields, Lynn; Henderson, Victoria; Caslake, Robert

    2017-07-01

    To assess the efficacy of comprehensive geriatric assessment (CGA) in prevention of delirium after hip fracture. Systematic review and metaanalysis. Ward based models on geriatrics wards and visiting team based models on orthopaedics wards were included. Four trials (three European, one U.S.; 973 participants) were identified. Two assessed ward-based, and two assessed team-based interventions. MEDLINE, EMBASE, CINAHL and PsycINFO databases; Clinicaltrials.gov; and the Central Register of Controlled Trials were searched. Reference lists from full-text articles were reviewed. Incidence of delirium was the primary outcome. Length of stay, delirium severity, institutionalization, long-term cognition and mortality were predefined secondary outcomes. Duration of delirium was included as a post hoc outcome. There was a significant reduction in delirium overall (relative risk (RR) = 0.81, 95% confidence interval (CI) = 0.69-0.94) in the intervention group. Post hoc subgroup analysis found this effect to be preserved in the team-based intervention group (RR = 0.77, 95% CI = 0.61-0.98) but not the ward-based group. No significant effect was observed on any secondary outcome. There was a reduction in the incidence of delirium after hip fracture with CGA. This is in keeping with results of non-randomized controlled trials and trials in other populations. Team-based interventions appeared superior in contrast to the Ellis CGA paper, but it is likely that heterogeneity in interventions and population studied affected this. © 2017, Copyright the Authors Journal compilation © 2017, The American Geriatrics Society.

  18. Terminal Sliding Mode Tracking Controller Design for Automatic Guided Vehicle

    Science.gov (United States)

    Chen, Hongbin

    2018-03-01

    Based on sliding mode variable structure control theory, the path tracking problem of automatic guided vehicle is studied, proposed a controller design method based on the terminal sliding mode. First of all, through analyzing the characteristics of the automatic guided vehicle movement, the kinematics model is presented. Then to improve the traditional expression of terminal sliding mode, design a nonlinear sliding mode which the convergence speed is faster than the former, verified by theoretical analysis, the design of sliding mode is steady and fast convergence in the limited time. Finally combining Lyapunov method to design the tracking control law of automatic guided vehicle, the controller can make the automatic guided vehicle track the desired trajectory in the global sense as well as in finite time. The simulation results verify the correctness and effectiveness of the control law.

  19. Performance evaluation and design of flight vehicle control systems

    CERN Document Server

    Falangas, Eric T

    2015-01-01

    This book will help students, control engineers and flight dynamics analysts to model and conduct sophisticated and systemic analyses of early flight vehicle designs controlled with multiple types of effectors and to design and evaluate new vehicle concepts in terms of satisfying mission and performance goals. Performance Evaluation and Design of Flight Vehicle Control Systems begins by creating a dynamic model of a generic flight vehicle that includes a range of elements from airplanes and launch vehicles to re-entry vehicles and spacecraft. The models may include dynamic effects dealing with structural flexibility, as well as dynamic coupling between structures and actuators, propellant sloshing, and aeroelasticity, and they are typically used for control analysis and design. The book shows how to efficiently combine different types of effectors together, such as aero-surfaces, TVC, throttling engines and RCS, to operate as a system by developing a mixing logic atrix. Methods of trimming a vehicle controll...

  20. Design control for standard U.S. EPRTM plants

    International Nuclear Information System (INIS)

    Mathews, Toney A.; Miller, Matthew P.

    2009-01-01

    The U.S. EPR TM design is being reviewed by the U.S. Nuclear Regulatory Commission (NRC) for reference by utility applicants to build and operate EPR TM nuclear reactors in the United States. While the U.S. EPR TM Design Certification and utility Combined License Applications are being reviewed by the NRC, the AREVA-Bechtel Consortium for Engineering Procurement and Construction is proceeding with developing the detailed design. Multiple, parallel regulatory and engineering activities require carefully prepared documents and rigorous design control processes. This paper will review the design control processes used by the AREVA-Bechtel Consortium. Design control must consider the basic design processes required to achieve an integrated, functional design, as well as design change control<