WorldWideScience

Sample records for international joint tribology

  1. Tribological aspects of joint intraaricular therapy.

    Science.gov (United States)

    Cherniakova, Yu M; Pinchuk, L S

    2011-01-01

    The condition of synovial joints affected by synovitis or degeneration dystrophy has been usually normalized by drugs of antibacterial, anti-inflammatory, immunomodulating and/or lubricating-protective action injected into the joint cavity. These preparations influence, but in different way, the friction in joints and wear of cartilages, even if they belong to the same pharmacological group and follow the same medication mechanism. With the development of a large group of lubricating-and-protective substitutes for the synovial fluid the tribological efficiency of injection drugs has begun to attract attention, whereas no information is available in the literature on pharmacopoeia or orthopedics about the lubricity of anti-inflammatory and antibacterial drugs commonly used as injections. The mechanisms by which structure and properties of lubricating films containing drugs undergo transformation under the influence of biological field in joints remain in fact unknown. In vitro experiments have been conducted to simulate a biofield of a joint; the lubricity of some injection drugs used in orthopedics has been evaluated.

  2. Metal-on-metal hip joint tribology.

    Science.gov (United States)

    Dowson, D; Jin, Z M

    2006-02-01

    The basic tribological features of metal-on-metal total hip replacements have been reviewed to facilitate an understanding of the engineering science underpinning the renaissance of these hard-on-hard joints. Metal-on-polymer hip replacements operate in the boundary lubrication regime, thus leading to the design guidance to reduce the femoral head diameter as much as is feasible to minimize frictional torque and volumetric wear. This explains why the gold-standard implant of this form from the past half-century had a diameter of only 22.225 mm (7/8 in). Metal-on-metal implants can operate in the mild mixed lubrication regime in which much of the applied load is supported by elastohydrodynamic films. Correct tribological design leads to remarkably low steady state wear rates. Promotion of the most effective elastohydrodynamic films calls for the largest possible head diameters and the smallest clearances that can reasonably be adopted, consistent with fine surface finishes, good sphericity and minimal structural elastic deformation of the cup on its foundations. This guidance, which is opposite in form to that developed for metal-on-polymer joints, is equally valid for solid (monolithic) metallic heads on metallic femoral stems and surface replacement femoral shells. Laboratory measurements of friction and wear in metal-on-metal joints have confirmed their potential to achieve a very mild form of mixed lubrication. The key lies in the generation of effective elastohydrodynamic lubricating films of adequate thickness compared with the composite roughness of the head and cup. The calculation of the film thickness is by no means easy, but the full procedure is outlined and the use of an empirical formula that displays good agreement with calculations based upon the full numerical solutions is explained. The representation of the lambda ratio, lambda, embracing both film thickness and composite roughness, is described.

  3. International Conference on Advances in Tribology and Engineering Systems

    CERN Document Server

    Deheri, Gunamani; Patel, Harshvadan; Mehta, Shreya

    2014-01-01

    This book contains advanced-level research material in the area of lubrication theory and related aspects, presented by eminent researchers during the International Conference on Advances in Tribology and Engineering Systems (ICATES 2013) held at Gujarat Technological University, Ahmedabad, India during October 15–17, 2013. The material in this book represents the advanced field of tribology and reflects the work of many eminent researchers from both India and abroad. The treatment of the presentations is the result of the contributions of several professionals working in the industry and academia. This book will be useful for students, researchers, academicians, and professionals working in the area of tribology, in general, and bearing performance characteristics, in particular, especially from the point-of-view of design. This book will also appeal to researchers and professionals working in fluid-film lubrication and other practical applications of tribology. A wide range of topics has been included des...

  4. Tribology and total hip joint replacement: current concepts in mechanical simulation.

    Science.gov (United States)

    Affatato, S; Spinelli, M; Zavalloni, M; Mazzega-Fabbro, C; Viceconti, M

    2008-12-01

    Interest in the rheology and effects of interacting surfaces is as ancient as man. This subject can be represented by a recently coined word: tribology. This term is derived from the Greek word "tribos" and means the "science of rubbing". Friction, lubrication, and wear mechanism in the common English language means the precise field of interest of tribology. Wear of total hip prosthesis is a significant clinical problem that involves, nowadays, a too high a number of patients. In order to acquire further knowledge on the tribological phenomena that involve hip prosthesis wear tests are conducted on employed materials to extend lifetime of orthopaedic implants. The most basic type of test device is the material wear machine, however, a more advanced one may more accurately reproduce some of the in vivo conditions. Typically, these apparatus are called simulators, and, while there is no absolute definition of a joint simulator, its description as a mechanical rig used to test a joint replacement, under conditions approximating those occurring in the human body, is acceptable. Simulator tests, moreover, can be used to conduct accelerated protocols that replicate/simulate particularly extreme conditions, thus establishing the limits of performance for the material. Simulators vary in their level of sophistication and the international literature reveals many interpretations of the design of machines used for joint replacement testing. This paper aims to review the current state of the art of the hip joint simulators worldwide. This is specified through a schematic overview by describing, in particular, constructive solutions adopted to reproduce in vivo conditions. An exhaustive commentary on the evolution and actually existing simulation standards is proposed by the authors. The need of a shared protocol among research laboratories all over the world could lead to a consensus conference.

  5. Tribology considerations for hip joint articulations in relation to the "new orthopaedic patient".

    Science.gov (United States)

    Rieker, C B

    2006-01-01

    The purpose of this review is to examine alternative bearings used in total hip arthroplasty (THA) and discuss the specific tribologic needs of the "New Orthopaedic Patient". As orthopaedic patients today are younger and more active, there is a clear need for hip joint implants and articulations minimising the amount of wear and guarantying better stability. Recent modern developments in tribology with highly cross-linked polyethylenes and hard-on-hard bearings allow the safe and effective use of larger diameter articulations in THA.

  6. The international joint commission

    OpenAIRE

    Clamens, Murray

    2005-01-01

    For over 92 years the International Joint Commission (IJC), United States and Canada, has effectively served the two nations in approving and providing continuous oversight of water resource projects along the 5000-mile common border, in assisting the governments in preventing and resolving issues and disagreements regarding the use of these waters, and in addressing other environmental issues affecting or potentially affecting one or both of the countries. During the first years of the 20th...

  7. Joint International Accelerator School

    CERN Multimedia

    CERN Accelerator School

    2014-01-01

    The CERN and US Particle Accelerator Schools recently organised a Joint International Accelerator School on Beam Loss and Accelerator Protection, held at the Hyatt Regency Hotel, Newport Beach, California, USA from 5-14 November 2014. This Joint School was the 13th in a series of such schools, which started in 1985 and also involves the accelerator communities in Japan and Russia.   Photo courtesy of Alfonse Pham, Michigan State University.   The school attracted 58 participants representing 22 different nationalities, with around half from Europe and the other half from Asia and the Americas. The programme comprised 26 lectures, each of 90 minutes, and 13 hours of case study. The students were given homework each day and had an opportunity to sit a final exam, which counted towards university credit. Feedback from the participants was extremely positive, praising the expertise and enthusiasm of the lecturers, as well as the high standard and quality of their lectures. Initial dis...

  8. Tribology studies of the natural knee using an animal model in a new whole joint natural knee simulator.

    Science.gov (United States)

    Liu, Aiqin; Jennings, Louise M; Ingham, Eileen; Fisher, John

    2015-09-18

    The successful development of early-stage cartilage and meniscus repair interventions in the knee requires biomechanical and biotribological understanding of the design of the therapeutic interventions and their tribological function in the natural joint. The aim of this study was to develop and validate a porcine knee model using a whole joint knee simulator for investigation of the tribological function and biomechanical properties of the natural knee, which could then be used to pre-clinically assess the tribological performance of cartilage and meniscal repair interventions prior to in vivo studies. The tribological performance of standard artificial bearings in terms of anterior-posterior (A/P) shear force was determined in a newly developed six degrees of freedom tribological joint simulator. The porcine knee model was then developed and the tribological properties in terms of shear force measurements were determined for the first time for three levels of biomechanical constraints including A/P constrained, spring force semi-constrained and A/P unconstrained conditions. The shear force measurements showed higher values under the A/P constrained condition (predominantly sliding motion) compared to the A/P unconstrained condition (predominantly rolling motion). This indicated that the shear force simulation model was able to differentiate between tribological behaviours when the femoral and tibial bearing was constrained to slide or/and roll. Therefore, this porcine knee model showed the potential capability to investigate the effect of knee structural, biomechanical and kinematic changes, as well as different cartilage substitution therapies on the tribological function of natural knee joints.

  9. The mechanical and tribological properties of UHMWPE loaded ALN after mechanical activation for joint replacements.

    Science.gov (United States)

    Gong, Kemeng; Qu, Shuxin; Liu, Yumei; Wang, Jing; Zhang, Yongchao; Jiang, Chongxi; Shen, Ru

    2016-08-01

    Ultra-high molecular weight polyethylene (UHMWPE) loaded with alendronate sodium (ALN) has tremendous potential as an orthopeadic biomaterial for joint replacements. However, poor mechanical and tribological properties of UHMWPE-ALN are still obstacle for further application. The purpose of this study was to investigate the effect and mechanism of mechanical activation on mechanical and tribological properties of 1wt% ALN-loaded UHMWPE (UHMWPE-ALN-ma). In this study, tensile test, small punch test and reciprocating sliding wear test were applied to characterize the mechanical and tribological properties of UHMWPE-ALN-ma. Scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and Fourier transform infrared spectroscopy (FTIR) were employed to characterize UHMWPE-ALN-ma. Tensile test and small punch test showed that Young׳s modulus, tensile strength and work-to-failure (WTF) of UHMWPE-ALN-ma increased significantly compared to those of UHMWPE-ALN. The friction coefficients and wear factors of UHMWPE-ALN-ma both decreased significantly compared to those of UHMWPE-ALN. Mechanical activation obviously reduced type 1 (void) and type 2 (the disconnected and dislocated machining marks) fusion defects of UHMWPE-ALN-ma, which were revealed by SEM images of freeze fracture surfaces after etching and lateral surfaces of specimens after extension to fracture, respectively. It was attributed to peeled-off layers and chain scission of molecular chains of UHMWPE particles after mechanical activation, which were revealed by SEM images and FTIR spectra of UHMWPE-ALN-ma and UHMWPE-ALN, respectively. Moreover, EDS spectra revealed the more homogeneous distribution of ALN in UHMWPE-ALN-ma compared to that of UHMWPE-ALN. The present results showed that mechanical activation was a potential strategy to improve mechanical and tribological properties of UHMWPE-ALN-ma as an orthopeadic biomaterial for joint replacements.

  10. International joint ventures

    DEFF Research Database (Denmark)

    Sørensen, Karsten Engsig

    2001-01-01

    The article analysis problems connected with corporate joint ventures. Among others the possible conflicts between the joint venture agreement and the statutes of the companies is examined, as well as certain problems connected to the fact that the joint venture partners have created commen control...... over their joint company....

  11. The tribological behaviour of different clearance MOM hip joints with lubricants of physiological viscosities.

    Science.gov (United States)

    Hu, X Q; Wood, R J K; Taylor, A; Tuke, M A

    2011-11-01

    Clearance is one of the most influential parameters on the tribological performance of metal-on-metal (MOM) hip joints and its selection is a subject of considerable debate. The objective of this paper is to study the lubrication behaviour of different clearances for MOM hip joints within the range of human physiological and pathological fluid viscosities. The frictional torques developed by MOM hip joints with a 50 mm diameter were measured for both virgin surfaces and during a wear simulator test. Joints were manufactured with three different diametral clearances: 20, 100, and 200 microm. The fluid used for the friction measurements which contained different ratios of 25 percent newborn calf serum and carboxymethyl cellulose (CMC) with the obtained viscosities values ranging from 0.001 to 0.71 Pa s. The obtained results indicate that the frictional torque for the 20 microm clearance joint remains high over the whole range of the viscosity values. The frictional torque of the 100 microm clearance joint was low for the very low viscosity (0.001 Pa s) lubricant, but increased with increasing viscosity value. The frictional torque of the 200 microm clearance joint was high at very low viscosity levels, however, it reduced with increasing viscosity. It is concluded that a smaller clearance level can enhance the formation of an elastohydrodynamic lubrication (EHL) film, but this is at the cost of preventing fluid recovery between the bearing surfaces during the unloaded phase of walking. Larger clearance bearings allow a better recovery of lubricant during the unloaded phase, which is necessary for higher viscosity lubricants. The selection of the clearance value should therefore consider both the formation of the EHL film and the fluid recovery as a function of the physiological viscosity in order to get an optimal tribological performance for MOM hip joints. The application of either 25 per cent bovine serum or water in existing in vitro tribological study should

  12. Altered joint tribology in osteoarthritis: Reduced lubricin synthesis due to the inflammatory process. New horizons for therapeutic approaches.

    Science.gov (United States)

    Szychlinska, M A; Leonardi, R; Al-Qahtani, M; Mobasheri, A; Musumeci, G

    2016-06-01

    Osteoarthritis (OA) is the most common form of joint disease. This review aimed to consolidate the current evidence that implicates the inflammatory process in the attenuation of synovial lubrication and joint tissue homeostasis in OA. Moreover, with these findings, we propose some evidence for novel therapeutic strategies for preventing and/or treating this complex disorder. The studies reviewed support that inflammatory mediators participate in the onset and progression of OA after joint injury. The flow of pro-inflammatory cytokines following an acute injury seems to be directly associated with altered lubricating ability in the joint tissue. The latter is associated with reduced level of lubricin, one of the major joint lubricants. Future research should focus on the development of new therapies that attenuate the inflammatory process and restore lubricin synthesis and function. This approach could support joint tribology and synovial lubrication leading to improved joint function and pain relief.

  13. An introduction to tribology.

    Science.gov (United States)

    Norris, James A; Stabile, Kathryne J; Jinnah, Riyaz H

    2008-01-01

    Tribology is the study of friction, wear, lubrication mechanisms, and their interrelationships. Biotribiology focuses on understanding diarthrodial joints and has been a branch of tribology since 1973. Since then, biotribology has played a prominent role in the evaluation and development of joint prostheses, contributing to reduced wear and increased longevity. Total joint replacements are now common for arthritic patients and are also used in treating a variety of other orthopaedic conditions. For this reason, a complete understanding of the joint lubrication and microstructure that exists in nature is crucial. A subfield of biotribology, biomimetic tribology, has been formed with this goal in mind. This review covers the basic concepts of tribology, provides a brief historical perspective on joint prostheses, and presents the application of tribology in understanding diarthrodial and prosthetic joints.

  14. COST 516 Tribology Symposium

    Energy Technology Data Exchange (ETDEWEB)

    Ronkainen, H.; Holmberg, K. [eds.

    1998-11-01

    Cost 516 Tribology action is the first joint European research action focusing on tribology, which originates in the approval of its Memorandum of understanding in February 1994. The COST 516 Tribology Symposium took place in Espoo, Finland from 14th to 15th May 1998. This was the first Symposium of the COST 516 Tribology action. The large number of research contributions at the Symposium, altogether almost SO, and their scientific and technical level, is an indication of the importance and significance of tribology research. The symposium proceedings contain papers in a wide variety of subjects, covering the three categories of the COST 516 Tribology action, namely Grease lubrication (GRIT), Tribology of renewable environmentally adapted lubricants (REAL) and Coatings and surface treatments (CAST). (orig.)

  15. Computational Intelligence : International Joint Conference

    CERN Document Server

    Rosa, Agostinho; Cadenas, José; Dourado, António; Madani, Kurosh; Filipe, Joaquim

    2016-01-01

    The present book includes a set of selected extended papers from the sixth International Joint Conference on Computational Intelligence (IJCCI 2014), held in Rome, Italy, from 22 to 24 October 2014. The conference was composed by three co-located conferences:  The International Conference on Evolutionary Computation Theory and Applications (ECTA), the International Conference on Fuzzy Computation Theory and Applications (FCTA), and the International Conference on Neural Computation Theory and Applications (NCTA). Recent progresses in scientific developments and applications in these three areas are reported in this book. IJCCI received 210 submissions, from 51 countries, in all continents. After a double blind paper review performed by the Program Committee, 15% were accepted as full papers and thus selected for oral presentation. Additional papers were accepted as short papers and posters. A further selection was made after the Conference, based also on the assessment of presentation quality and audience in...

  16. Computational Intelligence : International Joint Conference

    CERN Document Server

    Dourado, António; Rosa, Agostinho; Filipe, Joaquim; Kacprzyk, Janusz

    2016-01-01

    The present book includes a set of selected extended papers from the fifth International Joint Conference on Computational Intelligence (IJCCI 2013), held in Vilamoura, Algarve, Portugal, from 20 to 22 September 2013. The conference was composed by three co-located conferences:  The International Conference on Evolutionary Computation Theory and Applications (ECTA), the International Conference on Fuzzy Computation Theory and Applications (FCTA), and the International Conference on Neural Computation Theory and Applications (NCTA). Recent progresses in scientific developments and applications in these three areas are reported in this book. IJCCI received 111 submissions, from 30 countries, in all continents. After a double blind paper review performed by the Program Committee, only 24 submissions were accepted as full papers and thus selected for oral presentation, leading to a full paper acceptance ratio of 22%. Additional papers were accepted as short papers and posters. A further selection was made after ...

  17. 77 FR 41877 - International Joint Commission; International Joint Commission To Hold Public Hearings on Lake...

    Science.gov (United States)

    2012-07-16

    ... International Joint Commission; International Joint Commission To Hold Public Hearings on Lake Osoyoos The International Joint Commission (IJC) is inviting the public to comment on recommendations for the renewal of its... of the International Joint Commission's Osoyoos Lake Order now posted on the IJC Web......

  18. A retrospective survey of the use of laboratory tests to simulate internal combustion engine materials tribology problems

    Energy Technology Data Exchange (ETDEWEB)

    Blau, P.J.

    1992-12-31

    Progress in the Field of tribology strongly parallels, and has always been strongly driven by, developments and needs in transportation and related industries. Testing of candidate materials for internal combustion engine applications has historically taken several routes: (1) replacement of parts in actual engines subjected to daily use, (2) testing in special, instrumented test engines, (3) and simulative testing in laboratory tribometers using relatively simple specimens. The advantages and disadvantages of each approach are reviewed using historical examples. A four-decade, retrospective survey of the tribomaterials literature focused on the effectiveness of laboratory simulations for engine materials screening. Guidelines for designing and ducting successful tribology laboratory simulations will be discussed. These concepts were used to design a valve wear simulator at Oak Ridge National Laboratory.

  19. Designing an International Joint Venture Negotiation Game.

    Science.gov (United States)

    Kenkel, Phil; And Others

    1996-01-01

    Evaluates a simulation game that models management problems encountered in negotiating and managing international joint ventures. Designed to instruct executives of state-owned agribusinesses in Indonesia in abstract concepts such as partner rapport, transfer price conflicts, and marketing disagreements, its success suggests that simulation games…

  20. Designing an International Joint Venture Negotiation Game.

    Science.gov (United States)

    Kenkel, Phil; And Others

    1996-01-01

    Evaluates a simulation game that models management problems encountered in negotiating and managing international joint ventures. Designed to instruct executives of state-owned agribusinesses in Indonesia in abstract concepts such as partner rapport, transfer price conflicts, and marketing disagreements, its success suggests that simulation games…

  1. Internal derangement of the temporomandibular joint; Internal Derangement des Temporomandibulargelenks

    Energy Technology Data Exchange (ETDEWEB)

    Krestan, C.; Lomoschitz, F.; Puig, S.; Robinson, S. [Vienna Univ. (Austria). Zentrales Inst. fuer Radiodiagnostik

    2001-09-01

    Internal Derangement is one of the most common disorders of the Temporomandibular joint. It is defined as an abnormal anatomical relationship between the discus articularis and the other structures of the temporomandibular joint. More than 2/3 of patients with clinical symptoms of the temporomandibular joint have an internal derangement. The most frequent finding in internal derangement is an anterior dislocation of the disc with reduction after mouth opening. In more severe cases a complete anterior dislocation is found without reduction of the disc. Internal derangement is a risk factor for developing osteoarthritis with remodeling of the condylus and the fossa mandibularis. The most important modalities of radiologic diagnosis are arthrography, CT and MRI. The diagnosis of craniofacial dysfunction has been improved dramatically by modern imaging techniques, which have become essential tools for primary diagnostic and evaluation after conservative or surgical therapy. MRI has become the gold standard. (orig.) [German] Das Internal Derangement ist eine der haeufigsten Erkrankungen des Temporomandibulargelenks. Es ist definiert als eine abnorme anatomische Beziehung des Discus articularis zu den uebrigen gelenkbildenden Strukturen. Bei mehr als 2/3 der Patienten mit Kiefergelenkbeschwerden kann ein Internal Derangement nachgewiesen werden. Die haeufigste Form ist die Ventralverlagerung des Diskus bei erhaltener Reduktion waehrend der Mundoeffnung. Bei schwereren Formen kommt es zu totalen Ventralverlagerungen ohne Reduktion. Das Internal Derangement beguenstigt die Entwicklung einer Arthrose mit entsprechenden Veraenderungen am Caput mandibulae sowie an der Fossa mandibularis. Die Palette der bildgebenden Diagnostik reicht von der Arthrographie ueber die CT zur MRT. Durch die modernen Schnittbildverfahren wurde die Abklaerung der kraniofazialen Dysfunktion revolutioniert und sind heute essentieller Bestandteil der Initialdiagnostik sowie der Verlaufsbeurteilung

  2. Engineering tribology

    CERN Document Server

    Stachowiak, Gwidon

    2013-01-01

    Engineering Tribology, 4th Edition is an established introductory reference focusing on the key concepts and engineering implications of tribology. Taking an interdisciplinary view, the book brings together the relevant knowledge from different fields needed to achieve effective analysis and control of friction and wear. Updated to cover recent advances in tribology, this new edition includes new sections on ionic and mesogenic lubricants, surface texturing, and multiscale characterization of 3D surfaces and coatings. Current trends in nanotribology are discussed, such as those relating to

  3. Engineering tribology

    CERN Document Server

    Stachowiak, Gwidon; Batchelor, A W; Batchelor, Andrew W

    2005-01-01

    As with the previous edition, the third edition of Engineering Tribology provides a thorough understanding of friction and wear using technologies such as lubrication and special materials. Tribology is a complex topic with its own terminology and specialized concepts, yet is vitally important throughout all engineering disciplines, including mechanical design, aerodynamics, fluid dynamics and biomedical engineering. This edition includes updated material on the hydrodynamic aspects of tribology as well as new advances in the field of biotribology, with a focus throughout on the engineering ap

  4. (Tribology conferences and forums)

    Energy Technology Data Exchange (ETDEWEB)

    Yust, C.S.

    1990-11-30

    The principal meeting attended during this trip was the Japan International Tribology Conference Nagoya 1990. The conference encompassed a wide range of topics, including the tribology of ceramics, the tribology in high-performance automobiles, and many aspects of lubrication technology. Associated forums were also held on the tribology of advanced ceramics, on solid lubrication, and on automotive lubricants. Presentations made during the latter forum discussed anticipated trends in engine development and anticipated improvements in lubricants required for the next generation of engines. In addition to meetings, site visits were made to five industrial organizations to discuss ceramic tribology. Nippon Steel Corporation and Toshiba Corporation are both very active in the ceramic area, Nippon Steel from their interest in research on new materials and Toshiba from both an interest in new materials and in support of their work in electronic devices. Two engine manufacturers were also visited, Toyota Motor Corporation, and Nissan Motor Co., Ltd. These companies were somewhat reserved in their discussion of progress in the utilization of ceramics in automobile engines.

  5. Tribological comparison of materials

    Science.gov (United States)

    Shi, Bing

    Approximately 600,000 total joint replacement surgeries are performed each year in the United States. Current artificial joint implants are mainly metal-on-plastic. The synthetic biomaterials undergo degradation through fatigue and corrosive wear from load-bearing and the aqueous ionic environment of the human body. Deposits of inorganic salts can scratch weight-bearing surfaces, making artificial joints stiff and awkward. The excessive wear debris from polyethylene leads to osteolysis and potential loosening of the prosthesis. The lifetime for well-designed artificial joints is at most 10 to 15 years. A patient can usually have two total joint replacements during her/his lifetime. Durability is limited by the body's reaction to wear debris of the artificial joints. Wear of the artificial joints should be reduced. A focus of this thesis is the tribological performance of bearing materials for Total Replacement Artificial Joints (TRAJ). An additional focus is the scaffolds for cell growth from both a tissue engineering and tribological perspective. The tribological properties of materials including Diamond-like Carbon (DLC) coated materials were tested for TRAJ implants. The DLC coatings are chemically inert, impervious to acid and saline media, and are mechanically hard. Carbon-based materials are highly biocompatible. A new alternative to total joints implantation is tissue engineering. Tissue engineering is the replacement of living tissue with tissue that is designed and constructed to meet the needs of the individual patient. Cells were cultured onto the artificial materials, including metals, ceramics, and polymers, and the frictional properties of these materials were investigated to develop a synthetic alternative to orthopedic transplants. Results showed that DLC coated materials had low friction and wear, which are desirable tribological properties for artificial joint material. Cells grew on some of the artificial matrix materials, depending on the

  6. Tribological applications of biomaterials: an overview

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Tribological research is the study of lubrication, friction, and wear. Tribology of biomate-rials is to study how the materials work and fail. This will help us to produce better biomaterials.Tribology plays a very important role in improving the design and making successful biomaterialsfor medical purposes. Joints of human body, such as hip, knee, jaw, dental parts etc., all need toconsider the wear and lubrication problem. In this paper, we give a general introduction of bioma-terial research in tribological applications. Materials, the synthetic characterization, and their failureare introduced.

  7. Internal derangement of the temporomandibular joint: morphologic description with correlation to joint function.

    Science.gov (United States)

    Westesson, P L; Bronstein, S L; Liedberg, J

    1985-04-01

    Internal derangement of the temporomandibular joint has mainly been studied arthrographically from the standpoint of anterior disk displacement with or without reduction. Frequent clinical observations of disk deformation in joints with internal derangement implied the need for a systematic study of morphologic alterations associated with internal derangement. Therefore, morphology, internal derangement, and joint function were studied in 58 randomly selected autopsy specimens of the temporomandibular joint. The results showed that joints with superior disk position rarely demonstrated morphologic alterations. In joints with partially anterior disk position, disk deformation occurred somewhat more frequently (31%) and was consistently located in the part of the disk that was positioned anteriorly. Joints with completely anteriorly positioned disks showed disk deformation in 77% and irregularities of the articular surfaces in 65%. It appears that anterior disk position precedes disk deformation. Therefore, early causal treatment to correct symptomatic internal derangement appears indicated to decrease the possibility of development of disk deformation. Disk deformation was also closely associated with disturbed joint function and should therefore be an important consideration when one is planning treatment of internal derangement of the temporomandibular joint.

  8. Principles of tribology

    CERN Document Server

    Wen, Shizhu

    2011-01-01

    Professors Wen and Huang present current developments in tribology research along with tribology fundamentals and applications, including lubrication theory, lubrication design, friction mechanism, wear mechanism, friction control, and their applications. In addition to classical tribology, Wen and Huang cover the research areas of the modern tribology, as well as the regularities and characteristics of tribological phenomena in practice. Furthermore, the authors present the basic theory, numerical analysis methods, and experimental measuring techniques of tribology as well as their applicatio

  9. Learning from Success & Failure: International Joint Ventures in Emerging Markets

    DEFF Research Database (Denmark)

    Nielsen, Ulrik B.

    The purpose of the Ph.D. dissertation is to examine how do joint learning influence management of international joint ventures in emerging markets? Entering and developing presence in emerging markets often require foreign firms to set up International Joint Ventures (IJVs) with local partners...... their expectations. Inter-partner learning has been proposed in the literature as a major cause of IJV instability. However, current research indicates that when IJV partners engage in joint learning to create new IJV-specific knowledge that benefits both partners it stabilizes and sustains the IJV. Yet, joint...... learning in IJVs have rarely been examined in the context of IJVs in emerging markets. This paucity of studies concerning joint learning and knowledge creation in IJVs have been noted at a critical research gap in the literature....

  10. Internal derangements of the temporomandibular joint: description of clinical syndromes.

    Science.gov (United States)

    Schwartz, H C; Kendrick, R W

    1984-07-01

    Clinical findings and diagnostic criteria for internal derangements of the temporomandibular joint are outlined. Pathophysiology is discussed, including the role of predisposing factors and the relationship with myofascial pain-dysfunction syndrome.

  11. The post-formation management of international joint ventures

    DEFF Research Database (Denmark)

    Dao, Li

    2014-01-01

    International joint venture (IJV) is not a new organizational phenomenon in international business. Existing research in IJVs has provided a well-established body of knowledge informing much of the joint venture process from parent firms’ strategic consideration to implementation phase......, and particularly on major drivers of joint venture performance. Still, what we know less is about ‘soft’ aspects of collaboration underlying contextual constraints and dynamics in the joint venture process, such as individual sensemaking and identification. In light of this, the present paper aims at exploring...... a sensemaking approach to IJV post-formation management in search of capturing such ‘soft’, invisible managerial processes in a visible conceptualization that contributes to a better understanding of this complex organizational phenomenon. Empirical insights from cases of Danish – Vietnamese joint ventures...

  12. RILEM International Symposium on Materials and Joints in Timber Structures

    CERN Document Server

    Reinhardt, H-W; Garrecht, Harald

    2014-01-01

    This book contains the contributions from the RILEM International Symposium on Materials and Joints in Timber Structures that was held in Stuttgart, Germany from October 8 to 10, 2013. It covers recent developments in the materials and the joints used in modern timber structures. Regarding basic wooden materials, the contributions highlight the widened spectrum of products comprising cross-laminated timber, glulam and LVL from hardwoods and block glued elements. Timber concrete compounds, cement bonded wood composites and innovative light-weight constructions represent increasingly employed alternatives for floors, bridges and facades. With regard to jointing technologies, considerable advances in both mechanical connections and glued joints are presented. Self-tapping screws have created unprecedented options for reliable, strong as well as ductile joints and reinforcement technologies. Regarding adhesives, which constitute the basis of the jointing/laminating technology of modern timber products, extended o...

  13. IMPLEMENTATION OF ESG FOR INTERNATIONAL JOINT EDUCATION PROGRAMMES

    Directory of Open Access Journals (Sweden)

    Vera I. Zabotkina

    2016-12-01

    Full Text Available Introduction: joint international programmes stimulate staff and student mobility, provide joint studies, provide development of joint study programmes of excellence, and open up new possibilities for cooperation between countries. Promotion and development of joint international programmes depend on effective quality assurance system which is high on the universities` priority list. ESG provide solid basis for the quality assurance system development at both institutional and programme levels. The problems of ESG interpretation in compliance with national legislative systems and education traditions in the countries participating in Bologna process are paid much attention to. Our emphases are on the practical aspects of ESG (2015 version implementation. The article concentrates on one of the most acute problems facing Russian Higher Education Institutions in the field of development and promotion of joint international programs: the problem of setting up modern quality assurance systems compatible with those in European HEIs is closely correlating with the profile of the journal “Integration of Education”. The journal centers around the publications on the enhancement and dissemination of the best practices on integration of regional education in Russia and abroad. Materials and Methods: methodical and practical aspects of the implementation of the ESG provisions for international joint educational programs on the basis of the European approach to education quality are the materials of study. The descriptive method, analysis of documents about education quality, and synthesis were used as research methods. Results: the authors come up with concrete recommendations for the implementation of the ESG renewed version (2015 in Quality Assurance systems of joint international programmes. This approach enhances the practical value of ESG. Modern Quality Assurance system is one of the main prerequisites for the successful collaboration among higher

  14. Surfactants in tribology

    CERN Document Server

    Biresaw, Girma

    2014-01-01

    Surface science and tribology play very critical roles in many industries. Manufacture and use of almost all consumer and industrial products rely on the application of advanced surface and tribological knowledge. The fourth in a series, Surfactants in Tribology, Volume 4 provides an update on research and development activities connecting surfactants and tribological phenomena. Written by renowned subject matter experts, the book demonstrates how improved design of surfactants can be harnessed to control tribological phenomena. Profusely illustrated and copiously referenced, the chapters also

  15. Proceedings of the Third International Workshop on Jointed Structures.

    Energy Technology Data Exchange (ETDEWEB)

    Starr, Michael James; Brake, Matthew Robert; Segalman, Daniel Joseph; Bergman, Lawrence A.; Ewins, David J.

    2013-08-01

    The Third International Workshop on Jointed Structures was held from August 16th to 17th, 2012, in Chicago Illinois, following the ASME 2012 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. Thirty two researchers from both the United States and international locations convened to discuss the recent progress of mechanical joints related research and associated efforts in addition to developing a roadmap for the challenges to be addressed over the next five to ten years. These proceedings from the workshop include the minutes of the discussions and follow up from the 2009 workshop [1], presentations, and outcomes of the workshop. Specifically, twelve challenges were formulated from the discussions at the workshop, which focus on developing a better understanding of uncertainty and variability in jointed structures, incorporating high fidelity models of joints in simulations that are tractable/efficient, motivating a new generation of researchers and funding agents as to the importance of joint mechanics research, and developing new insights into the physical phenomena that give rise to energy dissipation in jointed structures. The ultimate goal of these research efforts is to develop a predictive model of joint mechanics.

  16. Third International Joint Conference on Computational Intelligence (IJCCI 2011)

    CERN Document Server

    Dourado, António; Rosa, Agostinho; Filipe, Joaquim; Computational Intelligence

    2013-01-01

    The present book includes a set of selected extended papers from the third International Joint Conference on Computational Intelligence (IJCCI 2011), held in Paris, France, from 24 to 26 October 2011. The conference was composed of three co-located conferences:  The International Conference on Fuzzy Computation (ICFC), the International Conference on Evolutionary Computation (ICEC), and the International Conference on Neural Computation (ICNC). Recent progresses in scientific developments and applications in these three areas are reported in this book. IJCCI received 283 submissions, from 59 countries, in all continents. This book includes the revised and extended versions of a strict selection of the best papers presented at the conference.

  17. 7th International Joint Conference on Computational Intelligence

    CERN Document Server

    Rosa, Agostinho; Cadenas, José; Correia, António; Madani, Kurosh; Ruano, António; Filipe, Joaquim

    2017-01-01

    This book includes a selection of revised and extended versions of the best papers from the seventh International Joint Conference on Computational Intelligence (IJCCI 2015), held in Lisbon, Portugal, from 12 to 14 November 2015, which was composed of three co-located conferences: The International Conference on Evolutionary Computation Theory and Applications (ECTA), the International Conference on Fuzzy Computation Theory and Applications (FCTA), and the International Conference on Neural Computation Theory and Applications (NCTA). The book presents recent advances in scientific developments and applications in these three areas, reflecting the IJCCI’s commitment to high quality standards.

  18. 'Soft' human resource management in small international joint ventures

    DEFF Research Database (Denmark)

    Dao, Li

    2012-01-01

    This paper examines the value creation aspects of HRM in international joint ventures of a relatively small size and their implications for strategic management. We assume that HRM in this context is rather a process than a function, and a ‘soft’ – humanistic rather than a ‘hard’, instrumentalist...

  19. Cultural Distance and the Performance of International Joint Ventures

    DEFF Research Database (Denmark)

    Christoffersen, Jeppe; Globerman, Steven; Nielsen, Bo Bernhard

    2013-01-01

    This study provides a critical summary and assessment of the empirical literature on the relationship between cultural distance and the performance of international joint ventures (IJVs) based on studies published over the period 1993-2008. The existing literature reports inconsistent and largely...

  20. Managing international joint venture relationships - A longitudinal perspective

    NARCIS (Netherlands)

    Hyder, A.; Ghauri, P.N.

    The purpose of the study is to describe and analyse the formation and development of international joint venture processes and relationships between the partners over time. Moreover, the study analyzes how far foreign partners have been successful in developing new contacts and in expanding their

  1. Cultural Distance and the Performance of International Joint Ventures

    DEFF Research Database (Denmark)

    Christoffersen, Jeppe; Globerman, Steven; Nielsen, Bo Bernhard

    2013-01-01

    This study provides a critical summary and assessment of the empirical literature on the relationship between cultural distance and the performance of international joint ventures (IJVs) based on studies published over the period 1993-2008. The existing literature reports inconsistent and largely...

  2. Individual learning effects on knowledge transfer in international joint ventures

    DEFF Research Database (Denmark)

    Dao, Li Thuy; Napier, Nancy

    2016-01-01

    This paper examines micro (individual-level) aspects of knowledge transfer and learning in international joint ventures in an emerging economy context. Learning by expatriate and local managers appears far more complex, mutually dependent, and significant to the knowledge transfer process than...... suggested in existing literature. Building upon conceptualizations of individual learning and cognitive – behavioural effects in an organisational context while drawing evidence from two cases of Danish – Vietnamese joint ventures, we propose a model of individual-level knowledge transfer and learning...

  3. Tribology in machine design

    CERN Document Server

    Stolarski, Tadeusz

    1999-01-01

    ""Tribology in Machine Design is strongly recommended for machine designers, and engineers and scientists interested in tribology. It should be in the engineering library of companies producing mechanical equipment.""Applied Mechanics ReviewTribology in Machine Design explains the role of tribology in the design of machine elements. It shows how algorithms developed from the basic principles of tribology can be used in a range of practical applications within mechanical devices and systems.The computer offers today's designer the possibility of greater stringen

  4. 4th International Joint Conference on Computational Intelligence

    CERN Document Server

    Correia, António; Rosa, Agostinho; Filipe, Joaquim

    2015-01-01

    The present book includes extended and revised versions of a set of selected papers from the Fourth International Joint Conference on Computational Intelligence (IJCCI 2012)., held in Barcelona, Spain, from 5 to 7 October, 2012. The conference was sponsored by the Institute for Systems and Technologies of Information, Control and Communication (INSTICC) and was organized in cooperation with the Association for the Advancement of Artificial Intelligence (AAAI). The conference brought together researchers, engineers and practitioners in computational technologies, especially those related to the areas of fuzzy computation, evolutionary computation and neural computation. It is composed of three co-located conferences, each one specialized in one of the aforementioned -knowledge areas. Namely: - International Conference on Evolutionary Computation Theory and Applications (ECTA) - International Conference on Fuzzy Computation Theory and Applications (FCTA) - International Conference on Neural Computation Theory a...

  5. Second International Joint Conference on Computational Intelligence (IJCCI 2010)

    CERN Document Server

    Correia, António; Rosa, Agostinho; Filipe, Joaquim; Computational Intelligence

    2012-01-01

    The present book includes a set of selected extended papers from the second International Joint Conference on Computational Intelligence (IJCCI 2010), held in Valencia, Spain, from 24 to 26 October 2010. The conference was composed by three co-located conferences:  The International Conference on Fuzzy Computation (ICFC), the International Conference on Evolutionary Computation (ICEC), and the International Conference on Neural Computation (ICNC). Recent progresses in scientific developments and applications in these three areas are reported in this book. IJCCI received 236 submissions, from 49 countries, in all continents. After a double blind paper review performed by the Program Committee, only 30 submissions were accepted as full papers and thus selected for oral presentation, leading to a full paper acceptance ratio of 13%. Additional papers were accepted as short papers and posters. A further selection was made after the Conference, based also on the assessment of presentation quality and audience inte...

  6. 77 FR 58204 - International Joint Commission Invites Public Comment on Upper Great Lakes Report via...

    Science.gov (United States)

    2012-09-19

    ... International Joint Commission Invites Public Comment on Upper Great Lakes Report via Teleconference and Extends Public Comment Period The International Joint Commission (IJC) announced that it is holding a... below: U.S. Section Secretary, International Joint Commission, 2000 L Street NW., Suite 615,...

  7. Encyclopedia of tribology

    CERN Document Server

    Chung, Yip-Wah

    2013-01-01

    TRIBOLOGY – the study of friction, wear and lubrication – impacts almost every aspect of our daily lives. The Springer Encyclopedia of Tribology is an authoritative and comprehensive reference covering all major aspects of the science and engineering of tribology that are relevant to researchers across all engineering industries and related scientific disciplines. This is the first major reference that brings together the science, engineering and technological aspects of tribology of this breadth and scope in a single work. Developed and written by leading experts in the field, the Springer Encyclopedia of Tribology covers the fundamentals as well as advanced applications across material types, different length and time scales, and encompassing various engineering applications and technologies. Exciting new areas such as nanotribology, tribochemistry and biotribology have also been included. As a six-volume set, the Springer Encyclopedia of Tribology comprises 1630 entries written by authoritative experts...

  8. Tribology in Manufacturing Technology

    CERN Document Server

    2013-01-01

    The present book aims to provide research advances on tribology in manufacturing technology for modern industry. This book can be used as a research book for final undergraduate engineering course (for example, mechanical, manufacturing, materials, etc) or as a subject on manufacturing at the postgraduate level. Also, this book can serve as a useful reference for academics, manufacturing and tribology researchers, mechanical, mechanical, manufacturing and materials engineers, professionals in related industries with manufacturing and tribology.

  9. Tribology in machine design

    CERN Document Server

    Stolarski, T A

    1990-01-01

    Tribology in Machine Design aims to promote a better appreciation of the increasingly important role played by tribology at the design stage in engineering. This book shows how algorithms developed from the basic principles of tribology can be used in a range of practical applications. The concept of tribodesign is introduced in Chapter 1. Chapter 2 is devoted to a brief discussion of the basic principles of tribology, including some concepts and models of lubricated wear and friction under complex kinematic conditions. Elements of contact mechanics, presented in Chapter 3, are confined to the

  10. Knowledge Creation in International Joint Ventures in Emerging Economies

    DEFF Research Database (Denmark)

    Nielsen, Ulrik B.

    Entering and developing presence in emerging economies often require foreign firms to set up International Joint Ventures (IJVs) with local partners, especially when the prime motive of the operation is to capture opportunities in the local markets (Mohr & Puck, 2005). IJVs have therefore become...... an important way for firms to enter these markets and a significant force in shaping a firm’s global strategy in expanding international activities abroad. However, research has shown that IJVs in emerging economies are unstable, and firms have experienced that performance of their IJVs in these emerging...... economies often does not meet their expectations (Fang & Zou, 2010). Extant research has shown that, in general, management of IJVs appears to be a difficult issue. 60-70% of all partnerships are not successful (Lambe, Spekman, & Hunt, 2002). Inter-partner learning has been proposed in the literature...

  11. Joint international conference ICIEOM-CIO-IIE 2015

    CERN Document Server

    Ferreira, Carlos; Junior, Milton; Prado, Carlos

    2017-01-01

    This book gathers a selection of the best papers presented at the joint international conference ICIEOM-CIO-IIE 2015, offering recent research on industrial engineering, management and operations from an international and interdisciplinary perspective. It includes contributions from different fields, such as operations research, modeling and simulation, production and service management and logistics, information systems and quality, and as such is of interest to both researchers and practitioners. Reflecting the interconnected nature of today’s production systems, characterized by intense flows of goods, information and individuals between companies and nations, it is a valuable resource for anyone wanting an in-depth understanding of the field to guide managerial practice in order to take full advantage of existing opportunities.

  12. Skin tribology: Science friction?

    NARCIS (Netherlands)

    Heide, van der E.; Zeng, X.; Masen, M.A.

    2013-01-01

    The application of tribological knowledge is not just restricted to optimizing mechanical and chemical engineering problems. In fact, effective solutions to friction and wear related questions can be found in our everyday life. An important part is related to skin tribology, as the human skin is fre

  13. CLASSIFICATION OF TEMPOROMANDIBULAR-JOINT OSTEOARTHROSIS AND INTERNAL DERANGEMENT .2. SPECIFIC DIAGNOSTIC-CRITERIA

    NARCIS (Netherlands)

    STEGENGA, B; DEBONT, LGM; BOERING, G

    1992-01-01

    Separate entities of temporomandibular joint osteoarthrosis and internal derangement are operationally defined. Criteria are based on an analysis of the diagnostic significance of symptoms and signs, principles of synovial joint pathology in general, and on therapeutic considerations. The primary go

  14. International Joint Conference on Mechanics, Design Engineering & Advanced Manufacturing

    CERN Document Server

    Nigrelli, Vincenzo; Oliveri, Salvatore; Peris-Fajarnes, Guillermo; Rizzuti, Sergio

    2017-01-01

    This book gathers papers presented at the International Joint Conference on Mechanics, Design Engineering and Advanced Manufacturing (JCM 2016), held on 14-16 September, 2016, in Catania, Italy. It reports on cutting-edge topics in product design and manufacturing, such as industrial methods for integrated product and process design; innovative design; and computer-aided design. Further topics covered include virtual simulation and reverse engineering; additive manufacturing; product manufacturing; engineering methods in medicine and education; representation techniques; and nautical, aeronautics and aerospace design and modeling. The book is divided into eight main sections, reflecting the focus and primary themes of the conference. The contributions presented here will not only provide researchers, engineers and experts in a range of industrial engineering subfields with extensive information to support their daily work; they are also intended to stimulate new research directions, advanced applications of t...

  15. Identification Of Damages Of Tribological Associations In Crankshaft And Piston Systems Of Two-Stroke Internal Combustion Engines Used As Main Propulsion In Sea-Going Vessels And Proposal Of Probabilistic Description Of Loads As Causes Of These Damages

    Directory of Open Access Journals (Sweden)

    Girtler Jerzy

    2015-04-01

    Full Text Available The article discusses damages of essential tribological associations in crankshaft and piston systems of large power two-stroke engines used as main engines, which take place during transport tasks performed by those ships. Difficulties are named which make preventing those damages impossible, despite the fact that the technical state of engines of this type is identified with the aid of complex diagnostic systems making use of advanced computer technology. It is demonstrated that one of causes of the damages is the lack of research activities oriented on recognising random properties of the loads leading to those damages. A proposal is made for the loads acting at a given time t on tribological associations in crankshaft and piston systems of internal combustion engines used as main engines to be considered as random variables Qt. At the same time the loads examined within a given time interval tr ≤ t ≤ tz would be considered stochastic processes {Q(t: t ≥ 0}. Essential properties of the loads of the abovementioned tribological associations are named and explained by formulating hypotheses which need empirical verification. Interval estimation is proposed for estimating the expected value E(Qt of the load Qt acting at time t. A relation is indicated between the mechanical load and the thermal load acting on tribological associations in the ship main engine crankshaft and piston system. A suggestion is formulated that a stochastic form of the relation between these types of load is to be searched for, rather than statistic relation, and a proposal is made to measure the intensity (strength of the stochastic relation using the Czuprow’s convergence coefficient.

  16. Bio-tribology.

    Science.gov (United States)

    Dowson, Duncan

    2012-01-01

    It is now forty six years since the separate topics of friction, lubrication, wear and bearing design were integrated under the title 'Tribology' [Department of Education and Science, Lubrication (Tribology) Education and Research. A Report on the Present Position and Industry's Needs, HMSO, London, 1966]. Significant developments have been reported in many established and new aspects of tribology during this period. The subject has contributed to improved performance of much familiar equipment, such as reciprocating engines, where there have been vast improvements in engine reliability and efficiency. Nano-tribology has been central to remarkable advances in information processing and digital equipment. Shortly after widespread introduction of the term tribology, integration with biology and medicine prompted rapid and extensive interest in the fascinating sub-field now known as Bio-tribology [D. Dowson and V. Wright, Bio-tribology, in The Rheology of Lubricants, ed. T. C. Davenport, Applied Science Publishers, Barking, 1973, pp. 81-88]. An outline will be given of some of the developments in the latter field.

  17. Introduction to tribology

    CERN Document Server

    Bhushan, Bharat

    2013-01-01

    A fully updated version of the popular Introduction to Tribology, the second edition of this leading tribology text introduces the major developments in the understanding and interpretation of friction, wear and lubrication.  Considerations of friction and wear have been fully revised to include recent analysis and data work, and friction mechanisms have been reappraised in light of current developments.   In this edition, the breakthroughs in tribology at the nano- and micro- level as well as recent developments in nanotechnology and magnetic storage technologies are introduce

  18. PATHOLOGY OF TEMPOROMANDIBULAR-JOINT INTERNAL DERANGEMENT AND OSTEOARTHROSIS

    NARCIS (Netherlands)

    DEBONT, LGM; STEGENGA, B

    Temporomandibular joint (TMJ) osteoarthrosis and disk displacement seem to be strongly related, but they may also represent mutually independent temporomandibular disorders. This paper presents relevant aspects of normal physiology and degeneration of synovial joints, aspects of normal

  19. The Cultural Context of Learning in International Joint Ventures.

    Science.gov (United States)

    Liu, Shimin; Vince, Russ

    1999-01-01

    A study of Chinese-Western joint business ventures showed that cultural context and different modes of managing and organizing must be considered. Successful joint ventures involve a process of collective, two-way learning. (SK)

  20. The Cultural Context of Learning in International Joint Ventures.

    Science.gov (United States)

    Liu, Shimin; Vince, Russ

    1999-01-01

    A study of Chinese-Western joint business ventures showed that cultural context and different modes of managing and organizing must be considered. Successful joint ventures involve a process of collective, two-way learning. (SK)

  1. PATHOLOGY OF TEMPOROMANDIBULAR-JOINT INTERNAL DERANGEMENT AND OSTEOARTHROSIS

    NARCIS (Netherlands)

    DEBONT, LGM; STEGENGA, B

    1993-01-01

    Temporomandibular joint (TMJ) osteoarthrosis and disk displacement seem to be strongly related, but they may also represent mutually independent temporomandibular disorders. This paper presents relevant aspects of normal physiology and degeneration of synovial joints, aspects of normal temporomandib

  2. Control of International Joint-ventures:A Literature Review

    Institute of Scientific and Technical Information of China (English)

    Rong Ding

    2013-01-01

    Joint-venture,which is considered as an important hybrid govern-ance structure between markets and hierarchy,has gained increasing popularity among firms that attempt to improve their competitive advantage through collabo-ration.This paper reviews the theoretical and empirical studies on control of joint-ventures with an emphasis on the specific control mechanisms used in practice to manage joint-ventures.Furthermore,special attention is given to how performance of joint-venture is measured and what determines its performance.This paper con-cludes with some suggestions for future research on control of joint-ventures.

  3. Correlation of clinical and MRI findings of tempero mandibular joint internal derangement

    Directory of Open Access Journals (Sweden)

    Chowdary U

    2006-01-01

    Full Text Available The most common clinical features of tempero-mandibular joint internal derangement are correlated with the MRI findings of shape of the disc in an attempt to find the etiology of tempero-mandibular joint internal derangement. In this study, the clinical parameters of pain, muscle tenderness, clicking with in the joint (like early, middle and late are correlated with the MRI findings of disc shapes. (like biconcave, thick, lengthened, folded, adhesion. The study reveals any trauma that leads to muscle tenderness results in internal derangement of tempero-mandibular joint.

  4. What differences in the cultural backgrounds of partners are detrimental for international joint ventures?

    NARCIS (Netherlands)

    H.G. Barkema (Harry); G.A.M. Vermeulen (Freek)

    1997-01-01

    textabstractAn international joint venture implies that a firm has to cooperate with a partner with a different cultural background. In this study, hypotheses about which differences in national culture are most disruptive for international joint ventures were developed and tested using Hofstede's f

  5. Surfactants in tribology, v.3

    CERN Document Server

    Biresaw, Girma

    2013-01-01

    The manufacture and use of almost every consumer and industrial product rely on application of advanced knowledge in surface science and tribology. These two disciplines are of critical importance in major economic sectors, such as mining, agriculture, manufacturing (including metals, plastics, wood, computers, MEMS, NEMS, appliances), construction, transportation, and medical instruments, transplants, and diagnostic devices. An up-to-date reference with contributions by experts in surface science and tribology, Surfactants in Tribology, Volume 3 discusses some of the underlying tribological a

  6. PREFACE: Joint Varenna-Lausanne International Workshop 2014

    Science.gov (United States)

    2014-11-01

    The 2014 joint Varenna-Lausanne international workshop on the theory of fusion plasmas was once more a great meeting. The programme covers a wide variety of topics, namely turbulence, MHD, edge physics and RF wave heating. The broad spectrum of skills involved in this meeting, from fundamental to applied physics, is striking. The works published in this special issue combine mathematics, numerics and physics at various levels - confirming the increasing integration of expertise in our community. As an incentive to read this cluster, let us mention a few outstanding results. Several papers address fundamental issues in turbulent transport, in particular the dynamics of structures. It is quite remarkable that this subject is now mature enough to propose signatures that can be tested by measurements. Linear and non linear MHD was also at the forefront. Several works illustrate the increasing level of realistic description of a fusion device, in particular by implementing complicated wall geometries. Moreover some noticeable progress has been made in the understanding of reconnection processes in collisionless regimes. The activity on radio-frequency heating and current drive is well represented, driven by the future operation of W7-X, ITER, and DEMO on a longer time scale. Finally the development of innovative numerical techniques, an old tradition of the conference, has driven several nice articles. The programme committee is traditionally keen in promoting young scientists. A number of senior scientists also attend the meeting on a regular basis, so that the attendance was nicely balanced. We believe that these efforts have been particularly fruitful this year. The number of young (and less young) faces was particularly impressive and this special issue illustrates this feature. The success of the 2014 edition brings evidence that the joint Varenna-Lausanne is the right place for presenting th The quality and size of the scientific production is illustrated by the

  7. In vivo three-dimensional motion analysis of the shoulder joint during internal and external rotation.

    Science.gov (United States)

    Koishi, Hayato; Goto, Akira; Tanaka, Makoto; Omori, Yasushi; Futai, Kazuma; Yoshikawa, Hideki; Sugamoto, Kazuomi

    2011-10-01

    The purpose of this study was to assess accurately the three-dimensional movements of the scapula and humerus relative to the thorax during internal/external rotation motion with abduction of the shoulder joint. Ten right shoulders of ten healthy volunteers were examined using a wide-gantry open magnetic resonance imaging (MRI) system. MRI was performed every 30° from 90° external rotation to 90° internal rotation of the shoulder joint. The contribution ratio of the scapulothoracic joint was 12.5% about the long axis of the humerus during internal/external rotation motion. With arm position changes from 90° external rotation to 60° internal rotation, most movement was performed by the glenohumeral joint. Conversely, at internal rotation of ≥60°, the scapula began to markedly tilt in the anterior direction. At 90° internal rotation, the scapula was significantly tilted anteriorly (p specific scapulohumeral motion pattern, whereby the glenohumeral joint moves with internal rotation and the scapulothoracic joint moves with anterior tilt together with internal rotation motion of the shoulder joint.

  8. International trade shows: Structure, strategy and performance of exhibitors at individual booths vs. joint booths

    DEFF Research Database (Denmark)

    Hansen, Kåre

    2000-01-01

    This paper examines differences in exhibitors who participate at international trade shows at joint booths and those who participate at individual booths. The structure, strategy, and trade show performance of exhibitors at joint booths and those at individual booths are analysed. The analysis of...... implications for exhibitors at interna-tional trade shows and export marketing programmes and other marketing programmes offering services to international trade show exhibitors....

  9. Gardosian Patterns in Tribology

    Science.gov (United States)

    DellaCorte, Christopher

    2004-01-01

    The following paper is a memorial retrospective on selected research of Dr. Michael N. Gardos. Dr. Gardos spent his professional career engaged in tribological research which often extended the scientific boundaries of the field. Several of the concepts he put forth into the tribology community were initially met with grave skepticism but over time his views have been largely embraced but not widely acknowledged. His approach to new research topics was often characterized by these qualities: 1) pioneering points of view, 2) the use of the model experiment, and 3) the presence of multiple research agendas for each single experiment. I have chosen to name his research approach as "Gardosian Patterns" in honor of his contributions to Tribology. Three specific examples of these patterns will be reviewed. One is the concept of atomic level tailoring of materials to control macroscopic properties. A second is the use of a model ball polishing experiment to identify high fracture toughness ceramics for use in rolling element bearings. A third Gardosian Pattern example is his pioneering work with the tribology of diamond and diamond films in which he proposed controlling friction via surface bond tailoring. In these examples, Gardos utilized conventional research tools in unconventional ways and, at times, even developed new tools which have become part of the mainstream. His remarkable career has left a positive and lasting mark on Tribology.

  10. Tribology of Nanocomposites

    CERN Document Server

    2013-01-01

    This book provides recent information on nanocomposites tribology. Chapter 1 provides information on tribology of bulk polymer nanocomposites and nanocomposite coatings. Chapter 2 is dedicated to nano and micro PTFE for surface lubrication of carbon fabric reinforced polyethersulphone composites. Chapter 3 describes Tribology of MoS2 -based nanocomposites. Chapter 4 contains information on friction and wear of Al2O2 -based composites with dispersed and agglomerated nanoparticles. Finally, chapter 5 is dedicated to wear of multi-scale phase reinforced composites. It is a useful reference for academics, materials and physics researchers, materials, mechanical and manufacturing engineers, both as final undergraduate and postgraduate levels. It is a useful reference for academics, materials and physics researchers, materials, mechanical and manufacturing engineers, both as final undergraduate and postgraduate levels.

  11. 76 FR 45311 - International Joint Commission Public Hearings on Binational Management of Lake of the Woods and...

    Science.gov (United States)

    2011-07-28

    ... International Joint Commission Public Hearings on Binational Management of Lake of the Woods and Rainy River Watershed The International Joint Commission (IJC) will hold public hearings on the final report of its.... Section, International Joint Commission, 2000 L Street, NW., Suite 615, Washington, DC 20440, Fax:...

  12. 78 FR 40260 - International Joint Commission: Public Comment on a Proposal for Lake Ontario and St. Lawrence...

    Science.gov (United States)

    2013-07-03

    ... International Joint Commission: Public Comment on a Proposal for Lake Ontario and St. Lawrence River Regulation The International Joint Commission (IJC) is inviting the public to comment on a proposal for managing... mail to either of the following addresses: International Joint Commission Secretary, U.S. Section,...

  13. Dynamic MR imaging of internal derangements of the temporomandibular joint: correlation with clinical signs and symptoms

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Young Ah; Chun, Eun Ju; Kim, Yoo Kyung; Yoo, Jeong Hyun; Choi, Hae Young; Kim, Hyun Jin [Ewha Womans Univ. College of Medicine, Seoul (Korea, Republic of); Chung, Eun Chul [Sungkyunkwan Univ. College of Medicine, Seoul (Korea, Republic of)

    1999-01-01

    To evaluate the correlation between findings of dynamic magnetic resonance (MR) imaging of the temporomandibular joint (TMJ) and clinical findings in patients with internal derangement of the TMJ. Dynamic MR images of 130 joints of 65 patients (17 men and 48 women aged 14 to 74; mean age, 34) with internal derangement of the TMJ were obtained using a 1.5-T MR imaging system. MR findings of anterior displacement, disc deformity and degenerative change were correlated with clinical findings including joint pain, clicking sound, crepitation and maximal mouth opening (MMO). Among 62 joints with TMJ pain, 32 showed anterior displacement without reduction, 15 showed disc deformity and 19 showed degenerative change. Among 49 joints in which there was a clicking sound, 24, 8 and 12 joints, respectively, showed the above-mentioned findings, while in seven with crepitation, these same findings were evident in five, six and four joints, respectively. Bilateral and unilateral joint disorders were observed in 17 and five patients, respectively, among 22 with MMO less than 30mm and in 11 and 18 of 42 patients with MMO between 30mm and 60mm. On MR imaging, patients with MMO less than 30mm usually showed bilateral joint disorders and those with crepitation showed chronic change. This indicates that there is high association between clinical findings of internal derangement of TMJ and MR findings.

  14. Method for instrumentation of orthotic joints for measurement of internal joint loads

    Directory of Open Access Journals (Sweden)

    Hochmann David

    2017-03-01

    Full Text Available The lack of knowledge of mechanical loads in orthotic joints can lead to oversized or breaking components. Previous studies suffer from small sample size and technical limitations. The goal of this study was to develop and validate a method that allows the direct measurement of moments in sagittal, frontal and transverse planes in knee and ankle joints of existing custom made orthoses.

  15. Nano-tribology and materials in MEMS

    CERN Document Server

    Satyanarayana, N; Lim, Seh

    2013-01-01

    This book brings together recent developments in the areas of MEMS tribology, novel lubricants and coatings for nanotechnological applications, biomimetics in tribology and fundamentals of micro/nano-tribology. Tribology plays important roles in the functioning and durability of machines at small length scales because of the problems associated with strong surface adhesion, friction, wear etc. Recently, a number of studies have been conducted to understand tribological phenomena at nano/micro scales and many new tribological solutions for MEMS have been proposed.

  16. TRANSFER OF MARKETING KNOWLEDGE IN THAI INTERNATIONAL JOINT VENTURE FIRMS

    Directory of Open Access Journals (Sweden)

    Osman Mohamad

    2010-07-01

    Full Text Available The focus of this study is the transfer of marketing knowledge within Thai joint venture firms. The perspectives of Thai managers were surveyed using a structured instrument. The analysis identifies seven dimensions of marketing management knowledge: promotion management, price management, logistics management, product innovation management, strategic marketing management, cross-cultural management, and target marketing management. The incidence of transfer is highest for activities in strategic marketing management, followed by price management. Transfer in product innovation management and target marketing management tends to vary with the age of the joint venture. Joint venture firms with foreign partners originating from Western, advanced, industrialised nations recorded the highest incidence of knowledge transfer occurring within product innovation management. This trend also holds true for the management of promotion activities. The incidence of transfer in target marketing management is lowest among firms with foreign partners from neighbouring nations. The incidence of knowledge transfer within product innovation and target marketing also tends to vary with the age of the joint venture. An analysis based on industry classification revealed that the transfer of knowledge regarding logistics management occurs most for firms in the manufacturing sector. In the service sector, the highest incidence of knowledge transfer within the areas of promotion management and target marketing management occurred in the agricultural sector.

  17. Cooperation and conflict in international joint venture relationship

    NARCIS (Netherlands)

    Kemp, Ron

    1999-01-01

    This article reports the results of an empirical study focusing on the relationship between the relative dependence asymmetry of partners in a joint venture, the level and intensity of conflict between the partners, the level of trust and norms of exchange between the partners, and the performance o

  18. Cooperation and conflict in international joint venture relationship

    NARCIS (Netherlands)

    Kemp, Ron

    1999-01-01

    This article reports the results of an empirical study focusing on the relationship between the relative dependence asymmetry of partners in a joint venture, the level and intensity of conflict between the partners, the level of trust and norms of exchange between the partners, and the performance o

  19. Cooperation and conflict in international joint venture relationship

    NARCIS (Netherlands)

    Kemp, Ron

    1999-01-01

    This article reports the results of an empirical study focusing on the relationship between the relative dependence asymmetry of partners in a joint venture, the level and intensity of conflict between the partners, the level of trust and norms of exchange between the partners, and the performance

  20. Tribology Experiment in Zero Gravity

    Science.gov (United States)

    Pan, C. H. T.; Gause, R. L.; Whitaker, A. F.; Finckenor, M. M.

    2015-01-01

    A tribology experiment in zero gravity was performed during the orbital flight of Spacelab 1 to study the motion of liquid lubricants over solid surfaces. The absence of a significant gravitational force facilitates observation of such motions as controlled by interfacial and capillary forces. Two experimental configurations were used. One deals with the liquid on one solid surface, and the other with the liquid between a pair of closed spaced surfaces. Time sequence photographs of fluid motion on a solid surface yielded spreading rate data of several fluid-surface combinations. In general, a slow spreading process as governed by the tertiary junction can be distinguished from a more rapid process which is driven by surface tension controlled internal fluid pressure. Photographs were also taken through the transparent bushings of several experimental journal bearings. Morphology of incomplete fluid films and its fluctuation with time suggest the presence or absence of unsteady phenomena of the bearing-rotor system in various arrangements.

  1. Designing and Managing Successful International Joint Development Programs

    Science.gov (United States)

    2016-04-30

    joint development programs are important because of their potential to reduce costs and increase partnership benefits such as interoperability, economies ... collaboration . In 2009, then-Under Secretary of Defense for Acquisition, Technology, and Logistics, Ashton Carter, issued an Acquisition Decision...In 2003, GAO published a report that argued “[t]he collaborative relationship between the customer and the product developer is essential to driving

  2. Predicting the Functional Roles of Knee Joint Muscles from Internal Joint Moments

    DEFF Research Database (Denmark)

    Flaxman, Teresa E; Alkjær, Tine; Simonsen, Erik B

    2017-01-01

    to the activation of individual muscles. RESULTS: Rectus femoris and tensor fasciae latae were classified as moment actuators for knee extension and hip flexion. Hamstrings were classified as moment actuators for hip extension and knee flexion. Gastrocnemius and hamstring muscles were classified as specific joint...

  3. Tribology of nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Davim, J. Paulo (ed.) [Aveiro Univ. (Portugal). Dept. of Mechanical Engineering

    2013-02-01

    This book provides a comprehensive review of the latest developments in nanotribology. It contains the following five chapters: 1. Tribology of bulk polymer nanocomposites and nanocomposite coatings (M. D. Bermudez, F. J. Carrion, C. Espejo, J. Sanes); 2. Nano and micro PTFE for surface lubrication of carbon fabric reinforced polyethersulphone composites (Jayashree Bijwe, Mohit Sharma); 3. Tribology of MoS{sub 2}-based nanocomposites (Kunhong Hu, Xianguo Hu, Yufu Xu, Xiaojun Sun, Yang Jiang); 4. Friction and wear of Al{sub 2}O{sub 3}-based composites with dispersed and agglomerated nanoparticles (Jinjun Lu, Jian Shang, Junhu Meng, Tao Wang); and 5. Wear of multi-scale phase reinforced composites (Zhenyu Jiang, Zhong Zhang).

  4. Tribology in Gaseous Hydrogen

    Science.gov (United States)

    Sawae, Yoshinori; Sugimura, Joich

    Hydrogen is expected as a clean and renewable energy carrier for future environment-friendly society. Many machine elements in hydrogen energy systems should be operating within hydrogen gas and tribological behavior, such as friction and wear, of bearings and seals are affected by the hydrogen environment through some interactions between material surfaces and gaseous hydrogen, i.e., physisorption of hydrogen molecules and following chemisorptions of dissociated atoms on metal surfaces, formation of metal hydride and reduction of metal oxide layer by hydrogen atoms diffused into bulk. Therefore, friction and wear characteristics of tribomaterials in the hydrogen environment should be appropriately understood to establish a design guideline for reliable hydrogen utilizing systems. This paper reviews the current knowledge about the effect of hydrogen on friction and wear of materials, and then describes our recent progress of hydrogen research in the tribology field.

  5. Characterization of tribological materials

    CERN Document Server

    Glaeser, William A

    2014-01-01

    This classic text discusses the use of advanced surface science characterization techniques in friction, adhesive and abrasive wear, boundary lubrication, contact fatigue, and other important failure processes. Surface characterization of bearings, gears, seals, and other manufactured rolling and sliding surfaces are increasingly routine in advanced quality control of processes and in the manufacture of precision components. This book is an indispensable asset to scientists and engineers using tribological characterization techniques. New content in this edition include: four new figures to illustrate real surface contact added to Chapter 1. coverage of the use of the Environmental SEM (ESEM) in examining wear of fiber glass filled PTFE added to chapter 4. new information on the wear of ceramics added to Chapter 5. updates for new analytical systems added to Chapter 6. coverage of Atomic Force Microscope (ATM) and its usefulness in the field of nano-tribology, providing not only full microtopography of s...

  6. Tribology theory versus experiment

    Science.gov (United States)

    Ferrante, John

    1987-01-01

    Tribology, the study of friction and wear of materials, has achieved a new interest because of the need for energy conservation. Fundamental understanding of this field is very complex and requires a knowledge of solid-state physics, material science, chemistry, and mechanical engineering. This paper is meant to be didactic in nature and outlines some of the considerations needed for a tribology research program. The approach is first to present a simple model, a field emission tip in contact with a flat surface, in order to elucidate important considerations, such as contact area, mechanical deformations, and interfacial bonding. Then examples from illustrative experiments are presented. Finally, the current status of physical theories concerning interfacial bonding are presented.

  7. International Joint Conference CISIS’15 and ICEUTE’15

    CERN Document Server

    Baruque, Bruno; Sedano, Javier; Quintián, Héctor; Corchado, Emilio

    2015-01-01

    This volume of Advances in Intelligent and Soft Computing contains accepted papers presented at the 8th International Conference on Computational Intelligence in Security for Information Systems (CISIS 2015) and the 6th International Conference on EUropean Transnational Education (ICEUTE 2015). These conferences were held in the beautiful and historic city of Burgos (Spain), in June 2015. The aim of the 8th CISIS conference is to offer a meeting opportunity for academic and industry-related researchers belonging to the various, vast communities of Computational Intelligence, Information Security, and Data Mining. The need for intelligent, flexible behaviour by large, complex systems, especially in mission-critical domains, is intended to be the catalyst and the aggregation stimulus for the overall event. After a through peer-review process, the CISIS 2015 International Program Committee selected 43 papers, written by authors from 16 different countries. In the case of 6th ICEUTE conference, the International ...

  8. Tribology of Graphite-Filled Polystyrene

    Directory of Open Access Journals (Sweden)

    Raffaele Gilardi

    2016-06-01

    Full Text Available Self-lubricating polymer compounds are currently used for a wide range of applications such as bearings, gears, and water meters. Under severe conditions such as high pressure, high velocity, and/or high temperatures, the material fails (PV limit. In this study, we investigated the effect of graphite on the tribological properties of polystyrene (PS with “ball-on-three-plates” tests. Graphite-filled PS plates were produced via an internal mixer and compression molding. Unhardened steel (1.4401 and nylon (PA66 balls were used for the tribological tests. Our results indicate that graphite loading, graphite type, and particle size have a big influence on the friction coefficient, the wear resistance, and the PV limit of PS both against steel and PA66. In particular, primary synthetic graphite performs better than secondary synthetic graphite due to the higher degree of crystallinity.

  9. Tribology in Metal Working

    OpenAIRE

    Nilsson, Maria

    2012-01-01

    This thesis focuses on the tribological performance of tool surfaces in two steel working operations, namely wire drawing and hot rolling. In all forming operations dimensions and surface finish of the products are of utmost importance. Forming basically includes three parts – forming conditions excluded – that may be changed; work material, tool and (possibly) lubricant. In the interface between work material and tool, the conditions are very aggressive with – generally or locally – high tem...

  10. Joint operating agreements: An international comparison from petroleum law

    Energy Technology Data Exchange (ETDEWEB)

    Black, A.J.; Dundas, H.R.

    1992-12-31

    Joint Operating Agreements ({open_quotes}JOAs{close_quotes}) are often used in capital-intensive resource industries by parties who wish to restrict their exposure, particularly in limiting costs or liability. Investment prudence in these industries necessitates a mix of participants who contribute some or all of the financing, intelligence, access to market or privileged access to the project itself. Typically, standard form documents provide the terms in JOAs where the venture is one of a recurring nature. This article examines elements of JOAs as they relate to the United Kingdom Continental Shelf ({open_quotes}UKCS{close_quotes}) industry, contrasting these with American, Canadian, Australian and New Zealand petroleum laws practice. After a brief history of JOAs, the paper reviews several areas of concern: control of joint operations, fiduciary duties, change of operator and production in kind. The paper also discusses the extent of a participant`s and several other issues. A final section investigates the future of JOAs, concentrating on their current problems and prospects in resource industries.

  11. Synthesized Multi-station Tribo-test System for Bio-tribological Evaluation in Vitro

    Institute of Scientific and Technical Information of China (English)

    WU Tonghai; DU Ying; LI Yang; WANG Shuo; ZHANG Zhinan

    2016-01-01

    Tribological tests play an important role on the evaluation of long-term bio-tribological performances of prosthetic materials for commercial fabrication. Those tests focus on the motion simulation of a real joint in vitro with only normal loads and constant velocities, which are far from the real friction behavior of human joints characterized with variable loads and multiple directions. In order to accurately obtain the bio-tribological performances of artificial joint materials, a tribological tester with a miniature four-station tribological system is proposed with four distinctive features. Firstly, comparability and repeatability of a test are ensured by four equal stations of the tester. Secondly, cross-linked scratch between tribo-pairs of human joints can be simulated by using a gear-rack meshing mechanism to produce composite motions. With this mechanism, the friction tracks can be designed by varying reciprocating and rotating speeds. Thirdly, variable loading system is realized by using a ball-screw mechanism driven by a stepper motor, by which loads under different gaits during walking are simulated. Fourthly, dynamic friction force and normal load can be measured simultaneously. The verifications of the performances of the developed tester show that the variable frictional tracks can produce different wear debris compared with one-directional tracks, and the accuracy of loading and friction force is within±5%. Thus the high consistency among different stations can be obtained. Practically, the proposed tester system could provide more comprehensive and accurate bio-tribological evaluations for prosthetic materials.

  12. Synthesized multi-station tribo-test system for bio-tribological evaluation in vitro

    Science.gov (United States)

    Wu, Tonghai; Du, Ying; Li, Yang; Wang, Shuo; Zhang, Zhinan

    2016-07-01

    Tribological tests play an important role on the evaluation of long-term bio-tribological performances of prosthetic materials for commercial fabrication. Those tests focus on the motion simulation of a real joint in vitro with only normal loads and constant velocities, which are far from the real friction behavior of human joints characterized with variable loads and multiple directions. In order to accurately obtain the bio-tribological performances of artificial joint materials, a tribological tester with a miniature four-station tribological system is proposed with four distinctive features. Firstly, comparability and repeatability of a test are ensured by four equal stations of the tester. Secondly, cross-linked scratch between tribo-pairs of human joints can be simulated by using a gear-rack meshing mechanism to produce composite motions. With this mechanism, the friction tracks can be designed by varying reciprocating and rotating speeds. Thirdly, variable loading system is realized by using a ball-screw mechanism driven by a stepper motor, by which loads under different gaits during walking are simulated. Fourthly, dynamic friction force and normal load can be measured simultaneously. The verifications of the performances of the developed tester show that the variable frictional tracks can produce different wear debris compared with one-directional tracks, and the accuracy of loading and friction force is within ±5%. Thus the high consistency among different stations can be obtained. Practically, the proposed tester system could provide more comprehensive and accurate bio-tribological evaluations for prosthetic materials.

  13. Aerospace Mechanisms and Tribology Technology: Case Study

    Science.gov (United States)

    Miyoshi, K.

    1999-01-01

    This paper focuses attention on tribology technology practice related to vacuum tribology. A case study describes an aspect of a real problem in sufficient detail for the engineer and scientist to understand the tribological situation and the failure. The nature of the problem is analyzed and the tribological properties are examined.

  14. Aerospace Mechanisms and Tribology Technology: Case Studies

    Science.gov (United States)

    Miyoshi, Kazuhisa

    1999-01-01

    This chapter focuses attention on tribology technology practice related to vacuum tribology and space tribology. Two case studies describe aspects of real problems in sufficient detail for the engineer and the scientist to understand the tribological situations and the failures. The nature of the problems is analyzed and the range of potential solutions is evaluated. Courses of action are recommended.

  15. Recent developments of green tribology

    Science.gov (United States)

    Zhang, Si-Wei

    2016-06-01

    Green tribology is a new field of great interest to a large number of tribologists. This article reviews the latest advances in this area including energy conservation, emission reduction, super-low friction and super-low wear, wind turbines, smart coatings, and fundamentals. Moreover, an overview of the future development of green tribology is also presented.

  16. Tribology. LC Science Tracer Bullet.

    Science.gov (United States)

    Havas, George D., Comp.

    Tribology is the science and technology of interacting surfaces in relative motion. It incorporates a number of scientific fields, including friction, wear, lubrication, materials science, and various branches of surface physics and surface chemistry. Tribology forms a vital part of engineering science. The interacting surfaces may be on machinery…

  17. Abstracts from the 2016 Joint Meeting of the International Confocal Group (ICG), the International Dermoscopy Society (IDS), and the International Society for Digital Imaging of the Skin (ISDIS)

    OpenAIRE

    Kang, DongKyun; Rocha, Lilian; Guitera, Pascale; Sierra, Heidy; Kose, Kivanc; Peterson, Gary; Rajadhyaksha, Milind; Bozkurt, Alican; Ariafar, Setareh; Dy, Jennifer; Brooks, Dana; Dickensheets, David; Prow, Tarl W; Hoang, Van; Lin, Lynlee

    2016-01-01

    What follows are the abstracts presented at the Joint Meeting of the International Confocal Group (ICG), the International Dermoscopy Society (IDS), and the International Society for Digital Imaging of the Skin (ISDIS). The meeting was held on March 5, 2016, in Washington, DC, USA, in conjunction with the annual meeting of the American Academy of Dermatology (Figure 1). The abstracts appear in the order in which they were presented.

  18. Tribology and coatings

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-06-01

    The future use of fuel-efficient, low-emission, advanced transportation systems (for example, those using low-heat-rejection diesel engines or advanced gas turbines) presents new challenges to tribologists and materials scientists. High service temperatures, corrosive environments, and extreme contact pressures are among the concerns that make necessary new tribological designs, novel materials, and effective lubrication concepts. Argonne is working on methods to reduce friction, wear and corrosion, such as soft metal coatings on ceramics, layered compounds, diamond coatings, and hard surfaces.

  19. International Joint Conference SOCO’16-CISIS’16-ICEUTE’16

    CERN Document Server

    López-Guede, José; Etxaniz, Oier; Herrero, Álvaro; Quintián, Héctor; Corchado, Emilio

    2017-01-01

    This volume of Advances in Intelligent and Soft Computing contains accepted papers presented at SOCO 2016, CISIS 2016 and ICEUTE 2016, all conferences held in the beautiful and historic city of San Sebastián (Spain), in October 2016. Soft computing represents a collection or set of computational techniques in machine learning, computer science and some engineering disciplines, which investigate, simulate, and analyze very complex issues and phenomena. After a through peer-review process, the 11th SOCO 2016 International Program Committee selected 45 papers. In this relevant edition a special emphasis was put on the organization of special sessions. Two special session was organized related to relevant topics as: Optimization, Modeling and Control Systems by Soft Computing and Soft Computing Methods in Manufacturing and Management Systems. The aim of the 9th CISIS 2016 conference is to offer a meeting opportunity for academic and industry-related researchers belonging to the various, vast communities of Compu...

  20. International Joint Conference SOCO’13-CISIS’13-ICEUTE’13

    CERN Document Server

    Baruque, Bruno; Klett, Fanny; Abraham, Ajith; Snášel, Václav; Carvalho, André; Bringas, Pablo; Zelinka, Ivan; Quintián, Héctor; Corchado, Emilio

    2014-01-01

    This volume of Advances in Intelligent and Soft Computing contains accepted papers presented at SOCO 2013, CISIS 2013 and ICEUTE 2013, all conferences held in the beautiful and historic city of Salamanca (Spain), in September 2013. Soft computing represents a collection or set of computational techniques in machine learning, computer science and some engineering disciplines, which investigate, simulate, and analyze very complex issues and phenomena.   After a through peer-review process, the 8th SOCO 2013 International Program Committee selected 40 papers which are published in these conference proceedings, and represents an acceptance rate of 41%. In this relevant edition a special emphasis was put on the organization of special sessions. Four special sessions were organized related to relevant topics as: Systems, Man, and Cybernetics, Data Mining for Industrial and Environmental Applications, Soft Computing Methods in Bioinformatics, and Soft Computing Methods, Modelling and Simulation in Electrical Engine...

  1. International Joint Conference SOCO’14-CISIS’14-ICEUTE’14

    CERN Document Server

    Ferreira, Iván; Bringas, Pablo; Klett, Fanny; Abraham, Ajith; Carvalho, André; Herrero, Álvaro; Baruque, Bruno; Quintián, Héctor; Corchado, Emilio

    2014-01-01

    This volume of Advances in Intelligent and Soft Computing contains accepted papers presented at SOCO 2014, CISIS 2014 and ICEUTE 2014, all conferences held in the beautiful and historic city of Bilbao (Spain), in June 2014. Soft computing represents a collection or set of computational techniques in machine learning, computer science and some engineering disciplines, which investigate, simulate, and analyze very complex issues and phenomena.   After a through peer-review process, the 9th SOCO 2014 International Program Committee selected 31 papers which are published in these conference proceedings. In this relevant edition a special emphasis was put on the organization of special sessions. One special session was organized related to relevant topics as: Soft Computing Methods in Manufacturing and Management Systems.   The aim of the 7th CISIS 2014 conference is to offer a meeting opportunity for academic and industry-related researchers belonging to the various, vast communities of Computational Intelligen...

  2. Joint International Workshop on Professional Learning, Competence Development and Knowledge Management - LOKMOL and L3NCD

    NARCIS (Netherlands)

    Memmel, Martin; Ras, Eric; Weibelzahl, Stephan; Burgos, Daniel; Olmedilla, Daniel; Wolpers, Martin

    2006-01-01

    Memmel, M., Ras, E., Weibelzahl, S., Burgos, D., Olmedilla, D., & Wolpers, M. (2006). Joint International Workshop on Professional Learning, Competence Development and Knowledge Management - LOKMOL and L3NCD. Proceedings of ECTEL 2006. October 2nd-4th, Crete, Greece. Retrieved October 2nd, 2006, fro

  3. Dual and common agency issues in international joint ventures: Evidence from China

    NARCIS (Netherlands)

    Roelfsema, H.J.|info:eu-repo/dai/nl/239815815; Zhang, Y.|info:eu-repo/dai/nl/328058335

    2010-01-01

    With the help of a theoretical model we analyze the relation between equity sharing in an international joint venture (EJV) and local public goods provision in a setting where the local government faces a commitment problem to provide public services ex post to the set-up of the firm. We show that t

  4. El Control y la Confianza: dos rivales en las "International Joint Ventures"

    Directory of Open Access Journals (Sweden)

    Francisco Puig Blanco

    2013-02-01

    Full Text Available Las empresas conjuntas internacionales(International Joint Ventures se caracterizan pordos factores íntimamente relacionados: el control y eloportunismo. En este trabajo, trataremos de analizarla relación entre ambos factores y estudiaremos quétipos de control ayudarían a prevenir o a reducirel oportunismo en este tipo de empresas. Además,trataremos de identificar las ventajas e inconvenientesasociados al control y analizaremos el caso de unaInternational Joint Venture formada por dos empresas,una española y la otra americana, cuyo fracaso se debió,en gran parte, a la ausencia de control (confianza y aloportunismo.   ABSTRACT International Joint Ventures are distinguished bytwo closely related factors: control and opportunism.In this paper we will try to analyze the relationshipbetween both factors and we will study what controlswould help prevent or reduce opportunism in thisclass of enterprises. Besides, we will attempt to identifythe advantages and inconveniences associated withcontrol, and analyze one case of an International JointVenture comprised by two companies, a Spanish and anAmerican one whose failure was largely due to lack ofcontrol (trust and opportunism.

  5. Working abroad, working with others: How firms learn to operate international joint ventures

    NARCIS (Netherlands)

    H.G. Barkema (Harry); O. Shenkar (Oded); G.A.M. Vermeulen (Freek); J.H.J. Bell (John)

    1997-01-01

    textabstractSuccessful international joint ventures entail both learning to operate across national boundaries and learning to cooperate. Hypotheses grounded in organizational learning theory were tested with event-history analysis and data on 1,493 expansions of 25 large Dutch firms between 1966 an

  6. SYMPTOMS OF TEMPOROMANDIBULAR-JOINT OSTEOARTHROSIS AND INTERNAL DERANGEMENT 30 YEARS AFTER NONSURGICAL TREATMENT

    NARCIS (Netherlands)

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

    1995-01-01

    To evaluate the long-term condition of temporomandibular joints (TMJs) affected by osteoarthrosis and internal derangement, 99 patients treated non-surgically between 1958 and 1962 were recalled for follow-up. The patients, 16 men and 83 women (mean age 58.2 years) with either reducing or permanent

  7. Mechanical and tribological properties of short discontinuous UHMWPE fiber reinforced UHMWPE

    NARCIS (Netherlands)

    Hofste, JM; vanVoorn, B; Pennings, AJ

    1997-01-01

    The tribological properties of Ultra-High Molecular Weight Polyethylene have generated new concern regarding the long-term clinical performance of total joint replacements. To extend the lifetime of artificial joints, it is necessary to decrease the wear rate of UHMWPE. One possible solution is the

  8. Principles and applications of tribology

    CERN Document Server

    Moore, Desmond F

    1975-01-01

    Principles and Applications of Tribology provides a mechanical engineering perspective of the fundamental understanding and applications of tribology. This book is organized into two parts encompassing 16 chapters that cover the principles of friction and different types of lubrication. Chapter 1 deals with the immense scope of tribology and the range of applications in the existing technology, and Chapter 2 is devoted entirely to the evaluation and measurement of surface texture. Chapters 3 to 5 present the fundamental concepts underlying the friction of metals, elastomers, and other material

  9. 一个新的干摩擦结合部法向接触阻尼方程%A novel expression of normal contact damping for dry tribology joint interface

    Institute of Scientific and Technical Information of China (English)

    田红亮; 严峥嵘; 郑金华; 张屹

    2016-01-01

    A new formula of normal contact damping for flexible joint interface was given by the revision fractal geometry theory and Hertz normal contact mechanics equation. Considering the changeable curvature radius at the tip of the summit and continuous load, the attaining way of differentiable function not partial differential function was induced to get two summits’ interacting normal contact stiffness formula. The numeral curves imply that the normal contact damping decreases firstly and afterwards increases with the augment of fractal dimension of the surface raspy profile. When the fractal dimension of the coarse surface profile is smaller than the first inflection point, the normal contact damping enhances with the increase of fractal roughness. If the fractal dimension is larger than the first inflexion point, the normal contact damping reduces with the increase of fractal roughness. As the normal contact load improves, the normal contact damping firstly diminishes whereafter gains. Two inflection points and one extreme small point in the simulation curves might provide the reference for the optimization design of these contact parameters in dry tribological joint interface.%依照矫正分形几何学理论与Hertz法向接触力学方程,建立新柔性结合部法向接触阻尼方程。考虑变化凸起顶端曲率半径与连续载荷,推出一种求导函数但非偏导函数获取办法,构建2个凸起之间互相作用的法向接触刚度方程。研究结果表明:法向接触阻尼随着表面粗糙轮廓分形维数的增大而先下降后增加;当表面粗糙轮廓分形维数小于第一拐点时,法向接触阻尼随着分形粗糙度的增大而增大;当表面粗糙轮廓分形维数大于第一拐点时,法向接触阻尼随着分形粗糙度的增大而减小;法向接触阻尼随着法向接触载荷的增大而先减小后增大。仿真曲线图中的2个拐点和1个极小值点为干摩擦结合部接触参数的优化设计提供了依据。

  10. Biomimetics in Tribology

    Science.gov (United States)

    Gebeshuber, I. C.; Majlis, B. Y.; Stachelberger, H.

    Science currently goes through a major change. Biology is evolving as new Leitwissenschaft, with more and more causation and natural laws being uncovered. The term `technoscience' denotes the field where science and technology are inseparably interconnected, the trend goes from papers to patents, and the scientific `search for truth' is increasingly replaced by search for applications with a potential economic value. Biomimetics, i.e. knowledge transfer from biology to technology, is a field that has the potential to drive major technical advances. The biomimetic approach might change the research landscape and the engineering culture dramatically, by the blending of disciplines. It might substantially support successful mastering of current tribological challenges: friction, adhesion, lubrication and wear in devices and systems from the meter to the nanometer scale. A highly successful method in biomimectics, the biomimicry innovation method, is applied in this chapter to identify nature's best practices regarding two key issues in tribology: maintenance of the physical integrity of a system, and permanent as well as temporary attachment. The best practices identified comprise highly diverse organisms and processes and are presented in a number of tables with detailed references.

  11. Tribology of alternative bearings.

    Science.gov (United States)

    Fisher, John; Jin, Zhongmin; Tipper, Joanne; Stone, Martin; Ingham, Eileen

    2006-12-01

    The tribological performance and biological activity of the wear debris produced has been compared for highly cross-linked polyethylene, ceramic-on-ceramic, metal-on-metal, and modified metal bearings in a series of in vitro studies from a single laboratory. The functional lifetime demand of young and active patients is 10-fold greater than the estimated functional lifetime of traditional polyethylene. There is considerable interest in using larger diameter heads in these high demand patients. Highly cross-linked polyethylene show a four-fold reduction in functional biological activity. Ceramic-on-ceramic bearings have the lowest wear rates and least reactive wear debris. The functional biological activity is 20-fold lower than with highly cross-linked polyethylene. Hence, ceramic-on-ceramic bearings address the tribological lifetime demand of highly active patients. Metal-on-metal bearings have substantially lower wear rates than highly cross-linked polyethylene and wear decreases with head diameter. Bedding in wear is also lower with reduced radial clearance. Differential hardness ceramic-on-metal bearings and the application of ceramic-like coatings reduce metal wear and ion levels.

  12. Individual learning effects on knowledge transfer in international joint ventures: An exploratory framework

    DEFF Research Database (Denmark)

    Dao, Li Thuy; Napier, Nancy

    2016-01-01

    This paper examines micro (individual-level) aspects of knowledge transfer and learning in international joint ventures in an emerging economy context. Learning by expatriate and local managers appears far more complex, mutually dependent, and significant to the knowledge transfer process than...... suggested in existing literature. Building upon conceptualizations of individual learning and cognitive – behavioural effects in an organisational context while drawing evidence from two cases of Danish – Vietnamese joint ventures, we propose a model of individual-level knowledge transfer and learning...

  13. Water tribology on graphene.

    Science.gov (United States)

    N'guessan, Hartmann E; Leh, Aisha; Cox, Paris; Bahadur, Prashant; Tadmor, Rafael; Patra, Prabir; Vajtai, Robert; Ajayan, Pulickel M; Wasnik, Priyanka

    2012-01-01

    Classical experiments show that the force required to slide liquid drops on surfaces increases with the resting time of the drop, t(rest), and reaches a plateau typically after several minutes. Here we use the centrifugal adhesion balance to show that the lateral force required to slide a water drop on a graphene surface is practically invariant with t(rest). In addition, the drop's three-phase contact line adopts a peculiar micrometric serrated form. These observations agree well with current theories that relate the time effect to deformation and molecular re-orientation of the substrate surface. Such molecular re-orientation is non-existent on graphene, which is chemically homogenous. Hence, graphene appears to provide a unique tribological surface test bed for a variety of liquid drop-surface interactions.

  14. Ionic liquids in tribology.

    Science.gov (United States)

    Minami, Ichiro

    2009-06-24

    Current research on room-temperature ionic liquids as lubricants is described. Ionic liquids possess excellent properties such as non-volatility, non-flammability, and thermo-oxidative stability. The potential use of ionic liquids as lubricants was first proposed in 2001 and approximately 70 articles pertaining to fundamental research on ionic liquids have been published through May 2009. A large majority of the cations examined in this area are derived from 1,3-dialkylimidazolium, with a higher alkyl group on the imidazolium cation being beneficial for good lubrication, while it reduces the thermo-oxidative stability. Hydrophobic anions provide both good lubricity and significant thermo-oxidative stability. The anions decompose through a tribochemical reaction to generate metal fluoride on the rubbed surface. Additive technology to improve lubricity is also explained. An introduction to tribology as an interdisciplinary field of lubrication is also provided.

  15. Ionic Liquids in Tribology

    Directory of Open Access Journals (Sweden)

    Ichiro Minami

    2009-06-01

    Full Text Available Current research on room-temperature ionic liquids as lubricants is described. Ionic liquids possess excellent properties such as non-volatility, non-flammability, and thermo-oxidative stability. The potential use of ionic liquids as lubricants was first proposed in 2001 and approximately 70 articles pertaining to fundamental research on ionic liquids have been published through May 2009. A large majority of the cations examined in this area are derived from 1,3-dialkylimidazolium, with a higher alkyl group on the imidazolium cation being beneficial for good lubrication, while it reduces the thermo-oxidative stability. Hydrophobic anions provide both good lubricity and significant thermo-oxidative stability. The anions decompose through a tribochemical reaction to generate metal fluoride on the rubbed surface. Additive technology to improve lubricity is also explained. An introduction to tribology as an interdisciplinary field of lubrication is also provided.

  16. Green tribology: principles, research areas and challenges.

    Science.gov (United States)

    Nosonovsky, Michael; Bhushan, Bharat

    2010-10-28

    In this introductory paper for the Theme Issue on green tribology, we discuss the concept of green tribology and its relation to other areas of tribology as well as other 'green' disciplines, namely, green engineering and green chemistry. We formulate the 12 principles of green tribology: the minimization of (i) friction and (ii) wear, (iii) the reduction or complete elimination of lubrication, including self-lubrication, (iv) natural and (v) biodegradable lubrication, (vi) using sustainable chemistry and engineering principles, (vii) biomimetic approaches, (viii) surface texturing, (ix) environmental implications of coatings, (x) real-time monitoring, (xi) design for degradation, and (xii) sustainable energy applications. We further define three areas of green tribology: (i) biomimetics for tribological applications, (ii) environment-friendly lubrication, and (iii) the tribology of renewable-energy application. The integration of these areas remains a primary challenge for this novel area of research. We also discuss the challenges of green tribology and future directions of research.

  17. Green tribology. Biomimetics, energy conservation and sustainability

    Energy Technology Data Exchange (ETDEWEB)

    Nosonovsky, Michael [Wisconsin Univ., Milwaukee, WI (United States). Dept. of Mechanical Engineering; Bhushan, Bharat (eds.) [Ohio State Univ., Columbus, OH (US). Nanoprobe Lab. for Bio- and Nanotechnology and Biomimetics (NLB2)

    2012-07-01

    Tribology is the study of friction, wear and lubrication. Recently, the concept of ''green tribology'' as ''the science and technology of the tribological aspects of ecological balance and of environmental and biological impacts'' was introduced. The field of green tribology includes tribological technology that mimics living nature (biomimetic surfaces) and thus is expected to be environmentally friendly, the control of friction and wear that is of importance for energy conservation and conversion, environmental aspects of lubrication and surface modification techniques, and tribological aspects of green applications such as wind-power turbines or solar panels. This book is the first comprehensive volume on green tribology. The chapters are prepared by leading experts in their fields and cover such topics as biomimetics, environmentally friendly lubrication, tribology of wind turbines and renewable sources of energy, and ecological impact of new technologies of surface treatment. (orig.)

  18. Clinical evaluation of physical therapy in the management of internal derangement of the temporomandibular joint.

    Science.gov (United States)

    Kirk, W S; Calabrese, D K

    1989-02-01

    This clinical cross-sectional study examines the favorable functional improvement in patients undergoing physical therapy for mild to moderate internal disc derangements of the temporomandibular joint. Sixty-eight patients with internal derangements were treated with physical therapeutic modalities as described by Rocabado. A success rate of 86% was achieved in patients with early- to mid-opening and late- to mid-closing clicks of the temporomandibular joint. Approximately one third of these patients required short-term occlusal bite appliances to assist in their management. A success rate of 7% was achieved in patients with late-opening and late-closing clicks. No patient with clicking on mediolateral movement was successfully managed with physical therapy. Likewise, patients with nonreducing anteriorly displaced discs of the temporomandibular joint did not respond well to physical therapy. Pain management was evaluated separately and showed subjective improvement in 82% of patients with mild to moderate disc dysfunction and pain. Only 29% of patients with late-opening clicking or locked joints experienced pain relief. When patients were classified according to occurrence of the clicking phenomenon, interesting trends relating to duration of symptoms were found. Twenty-two patients who did not respond favorably to physical therapy underwent surgical procedures. Findings in these patients offer suggestions about why nonsurgical therapy is not successful in certain cases.

  19. Role conflict and ambiguity of CEOs in international joint ventures: a transaction cost perspective.

    Science.gov (United States)

    Gong, Y; Shenkar, O; Luo, Y; Nyaw, M K

    2001-08-01

    Insights from transaction cost economics were used to study the boundary conditions underlying the role conflict and ambiguity of 265 CEOs in Chinese-based international joint ventures. Role conflict and ambiguity were lower when the contract between parents was more complete. Contract completeness fully mediated the effects of parent objective gap and parent formalization on role ambiguity but only partially so in the case of role conflict. Role conflict was lower when the foreign parent was dominant in the venture but higher when the local parent was dominant. Role conflict and ambiguity were inversely related to cultural distance. Neither construct had a detrimental effect on international joint venture performance. Implications for role theory are discussed.

  20. FUNCTIONS OF SOCIAL RELATIONSHIPS IN THE ORGANIZING OF AN INTERNATIONAL JOINT VENTURE

    Directory of Open Access Journals (Sweden)

    Daniel Serafim BROTEA

    2009-12-01

    Full Text Available This paper examines the use of social relationships in the organizing of a business network in the case of an international joint venture (IJV developing over time. The organizing process and the multicultural setting of the international joint venture emphasize the actions of and interactions between individuals from various organizations. The IJV-managers' use of their social relationships in business organizing is explored through analysis of narratives of IJVmanagers in a longitudinal single case to provide empirically grounded theory. From the in-depth interviews with IJV-managers the business relationships are identified as characterized by four possible levels of interpersonal relationships whose type influences the functions of the relationships and visa versa. One business relationship may contain only one or many of these interpersonal levels and an effective business relationship contains the appropriate interpersonal level for the business issue at hand.

  1. Effect of Joint Commission International Accreditation on the Nursing Work Environment in a Tertiary Medical Center.

    Science.gov (United States)

    Kagan, Ilya; Farkash-Fink, Naomi; Fish, Miri

    2016-01-01

    How might a tertiary hospital's nursing staff respond to the huge improvement effort required for external accreditation if they are encouraged to lead the change process themselves? This article reports the results of a concurrent evaluation of the nursing work climate at ward level, before and after accreditation by the Joint Commission International. Physician-nurse relations improved; the involvement of social workers, dieticians, and physiotherapists increased; support services responded more quickly to requests; and management-line staff relations became closer.

  2. Joint international meeting on geographical names: Združena mednarodna konferenca o zemljepisnih imenih:

    OpenAIRE

    2001-01-01

    The Joint International Meeting on Geographical Names of the United Nations Group of Experts on Geographical Names (UNGEGN) working group was held in Ljubljana, Slovenia, from 18th to 20th April 2001. The report presents six conference themes, e.g. a uniform method for compilation of gazetteers suitable for digital processing and issues concerning the standardization of geographical names with special attention paid to exonyms and transliteration methods. An important conclusion made at the c...

  3. Melting the Iron Curtain: opportunities for public health collaboration through international joint ventures.

    Science.gov (United States)

    Gellert, G A; Kaznady, S I

    1991-03-16

    The opportunities for international public health collaboration through joint business ventures between the USSR and Western nations, an arrangement that would benefit the public, industry, and the medical community, are discussed. Evidence indicates that the state of health of the Soviet population is declining rapidly; the Soviet minister has called for a major restructuring of the health care system, one that places greater emphasis on prevention. Although the USSR has begun to look to the West for economic and political guidance, it is suggested that Soviets would be ill-advised to discard the goal of universal access to health care and adopt, for example, the US model (the US itself is currently debating the appropriate function of government in health care). The USSR, however, could benefit from some of the private-public collaborations that already take place in the West. In the USSR, this collaboration could take the form of joint ventures. Such joint ventures in public health already exist in the USSR. For example, the multinational Tambrands Inc. Has established an international joint venture in the Ukraine to manufacture tampons. Its Soviet counterpart, Femtech, provides labor, supplies, facilities, and marketing, while Tambrands provides its trademark, plant design, equipment, training, and management. Between 1990 and 1991, Tambrands increased its market share of tampons from 3% to 22%. A whole range of public health needs that could be met through joint ventures, such as the provision of badly needed contraceptives, is envisioned. It is concluded that such practices would not only be good business, but also good for the health of the Soviet people.

  4. The tribology of metal-on-metal total hip replacements.

    Science.gov (United States)

    Scholes, S C; Unsworth, A

    2006-02-01

    Total hip surgery is an effective way of alleviating the pain and discomfort caused by diseased or damaged joints. However, in the majority of cases, these joints have a finite life. The main reason for failure is osteolysis (bone resorption). It is well documented that an important cause of osteolysis, and therefore the subsequent loosening and failure of conventional metal- or ceramic-on-ultra-high molecular weight polyethylene joints, is the body's immunological response to the polyethylene wear particles. To avoid this, interest has been renewed in metal-on-metal joints. The intention of this paper is to review the studies that have taken place within different laboratories to determine the tribological performance of new-generation metal-on-metal total hip replacements. These types of joint offer a potential solution to enhance the longevity of prosthetic hip systems; however, problems may arise owing to the effects of metal ion release, which are, as yet, not fully understood.

  5. Lubricin in synovial fluid of mild and severe temporomandibular joint internal derangements

    Science.gov (United States)

    Perrotta, Rosario E.; Almeida, Luis-Eduardo; Loreto, Carla; Musumeci, Giuseppe

    2016-01-01

    Background To understand the molecular basis of temporomandibular joint (TMJ) pathologies, we aimed to investigate the lubricin levels in the TMJ synovial fluid (SF) of patients with mild to severe internal derangements (IDs). Material and Methods A total, 34 joints were the study group. Only patients, with a Wilkes stage of III, IV and V were included, in this sample. Control group consisted of SF from eight joints, from patients undergoing to orthognatic surgery. Concentrations of lubricin in the SF from both samples were measured using ELISA system. Results The mean lubricin concentration was 7.029 ± 0.21 µg/mL in stage III patients; 5.64 ± 0.10 µg/mL in stage IV patients, and 4.78 ± 0.11 µg/mL in stage V patients. The lubricin levels from stage IV and stage V patients differed significantly (P ≤ 0.001) from those of control subjects. Lubricin levels were inversely correlated with age and to VAS score. Conclusions The results of this cross-sectional study highlight the relationship between disease severity and the levels of lubricin in TMJ SF. Our findings suggest that novel biotherapeutic approaches, including the administration of recombinant lubricin in the joint cavity, for the treatment of TMJ diseases can be developed. Key words:Lubricin, TMJ, derangements, synovial fluid. PMID:27694778

  6. Relations between thickness of UHMWPE's wear debris and positive pressure of tribological system

    Institute of Scientific and Technical Information of China (English)

    LIU HongTao; GE ShiRong

    2008-01-01

    MiaoXAM2.5X-50X Ultrahigh Precision Surface 3D Profiler is introduced to research the relations be-tween thickness of UHMWPE's wear debris and positive pressure of tribological system. Research re-sults show that thickness of wear debris owns evident classification, and the first grade thickness math model and the second grade thickness math model are built. By the second grade thickness math model, the true force condition in the tribological system can be gotten, and the model can be used as a tool to modify simulating parameters of the tribological system, and it is an important inspecting method to the airtight system which cannot be examined in real time. The first grade thickness math model can describe the true working load and surface condition of work piece in the tribological sys-tem, and is an effective description method for the running condition of frictional pairs. The research results at different lubricating conditions testify the relations between thicknesses of wear debris and positive pressure of the tribological system. The fractal relation between maximal thickness of wear debris and positive pressure is discussed. The conceptions of the immutability principle and charac-teristic granularity of wear debris thickness are brought forward and discussed. In conclusion, as a stable tribological parameter owning mechanical theory basis, wear debris thickness will play an im-portant part in fault diagnosis, especially for the airtight system such as artificial joint.

  7. Green Tribology Biomimetics, Energy Conservation and Sustainability

    CERN Document Server

    Bhushan, Bharat

    2012-01-01

    Tribology is the study of friction, wear and lubrication. Recently, the concept of “green tribology” as “the science and technology of the tribological aspects of ecological balance and of environmental and biological impacts” was introduced. The field of green tribology includes tribological technology that mimics living nature (biomimetic surfaces) and thus is expected to be environmentally friendly, the control of friction and wear that is of importance for energy conservation and conversion, environmental aspects of lubrication and surface modification techniques, and tribological aspects of green applications such as wind-power turbines or solar panels. This book is the first comprehensive volume on green tribology. The chapters are prepared by leading experts in their fields and cover such topics as biomimetics, environmentally friendly lubrication, tribology of wind turbines and renewable sources of energy, and ecological impact of new technologies of surface treatment.

  8. Pierre Auger Observatory and Telescope Array: Joint Contributions to the 33rd International Cosmic Ray Conference (ICRC 2013)

    CERN Document Server

    Array, The Telescope; Abu-Zayyad, T; Allen, M; Anderson, R; Azuma, R; Barcikowski, E; Belz, J W; Bergman, D R; Blake, S A; Cady, R; Chae, M J; Cheon, B G; Chiba, J; Chikawa, M; Cho, W R; Fujii, T; Fukushima, M; Goto, K; Hanlon, W; Hayashi, Y; Hayashida, N; Hibino, K; Honda, K; Ikeda, D; Inoue, N; Ishii, T; Ishimori, R; Ito, H; Ivanov, D; Jui, C C H; Kadota, K; Kakimoto, F; Kalashev, O; Kasahara, K; Kawai, H; Kawakami, S; Kawana, S; Kawata, K; Kido, E; Kim, H B; Kim, J H; Kitamura, S; Kitamura, Y; Kuzmin, V; Kwon, Y J; Lan, J; Lundquist, J P; Machida, K; Martens, K; Matsuda, T; Matsuyama, T; Matthews, J N; Minamino, M; Mukai, K; Myers, I; Nagasawa, K; Nagataki, S; Nakamura, T; Nanpei, H; Nonaka, T; Nozato, A; Ogio, S; Oh, S; Ohnishi, M; Ohoka, H; Oki, K; Okuda, T; Ono, M; Oshima, A; Ozawa, S; Park, I H; Pshirkov, M S; Rodriguez, D C; Rubtsov, G; Ryu, D; Sagawa, H; Sakurai, N; Sampson, A L; Scott, L M; Shah, P D; Shibata, F; Shibata, T; Shimodaira, H; Shin, B K; Shirahama, T; Smith, J D; Sokolsky, P; Springer, R W; Stokes, B T; Stratton, S R; Stroman, T A; Takamura, M; Takeda, M; Taketa, A; Takita, M; Tameda, Y; Tanaka, H; Tanaka, K; Tanaka, M; Thomas, S B; Thomson, G B; Tinyakov, P; Tkachev, I; Tokuno, H; Tomida, T; Troitsky, S; Tsunesada, Y; Tsutsumi, K; Uchihori, Y; Udo, S; Urban, F; Vasiloff, G; Wada, Y; Wong, T; Yamaoka, H; Yamazaki, K; Yang, J; Yashiro, K; Yoneda, Y; Yoshida, S; Yoshii, H; Zollinger, R; Zundel, Z; Aab, A; Abreu, P; Aglietta, M; Ahlers, M; Ahn, E J; Albuquerque, I F M; Allekotte, I; Allen, J; Allison, P; Almela, A; Castillo, J Alvarez; Alvarez-Muniz, J; Batista, R Alves; Ambrosio, M; Aminaei, A; Anchordoqui, L; Andringa, S; Antivcic, T; Aramo, C; Arqueros, F; Asorey, H; Assis, P; Aublin, J; Ave, M; Avenier, M; Avila, G; Badescu, A M; Barber, K B; Bardenet, R; Baeuml, J; Baus, C; Beatty, J J; Becker, K H; Belletoile, A; Bellido, J A; BenZvi, S; Berat, C; Bertou, X; Biermann, P L; Billoir, P; Blanco, F; Blanco, M; Bleve, C; Blumer, H; Bohacova, M; Boncioli, D; Bonifazi, C; Bonino, R; Borodai, N; Brack, J; Brancus, I; Brogueira, P; Brown, W C; Buchholz, P; Bueno, A; Burton, R E; Buscemi, M; Caballero-Mora, K S; Caccianiga, B; Caccianiga, L; Candusso, M; Caramete, L; Caruso, R; Castellina, A; Cataldi, G; Cazon, L; Cester, R; Cheng, S H; Chiavassa, A; Chinellato, J A; Chudoba, J; Cilmo, M; Clay, R W; Cocciolo, G; Colalillo, R; Collica, L; Coluccia, M R; Conceicao, R; Contreras, F; Cook, H; Cooper, M J; Coutu, S; Covault, C E; Criss, A; Cronin, J; Curutiu, A; Dallier, R; Daniel, B; Dasso, S; Daumiller, K; Dawson, B R; de Almeida, R M; De Domenico, M; de Jong, S J; De La Vega, G; Junior, W J M de Mello; Neto, J R T de Mello; De Mitri, I; de Souza, V; de Vries, K D; del Peral, L; Deligny, O; Dembinski, H; Dhital, N; Di Giulio, C; Diaz, J C; Castro, M L Diaz; Diep, P N; Diogo, F; Dobrigkeit, C; Docters, W; D'Olivo, J C; Dong, P N; Dorofeev, A; Anjos, J C dos; Dova, M T; Ebr, J; Engel, R; Erdmann, M; Escobar, C O; Espadanal, J; Etchegoyen, A; Luis, P Facal San; Falcke, H; Fang, K; Farrar, G; Fauth, A C; Fazzini, N; Ferguson, A P; Fick, B; Figueira, J M; Filevich, A; Filipcic, A; Foerster, N; Fox, B D; Fracchiolla, C E; Fraenkel, E D; Fratu, O; Frohlich, U; Fuchs, B; Gaior, R; Gamarra, R F; Gambetta, S; Garcia, B; Roca, S T Garcia; Garcia-Gamez, D; Garcia-Pinto, D; Garilli, G; Bravo, A Gascon; Gemmeke, H; Ghia, P L; Giller, M; Gitto, J; Glaser, C; Glass, H; Albarracin, F Gomez; Berisso, M Gomez; Vitale, P F Gomez; Goncalves, P; Gonzalez, J G; Gookin, B; Gorgi, A; Gorham, P; Gouffon, P; Grebe, S; Griffith, N; Grillo, A F; Grubb, T D; Guardincerri, Y; Guarino, F; Guedes, G P; Hansen, P; Harari, D; Harrison, T A; Harton, J L; Haungs, A; Hebbeker, T; Heck, D; Herve, A E; Hill, G C; Hojvat, C; Hollon, N; Homola, P; Hoerandel, J R; Horvath, P; Hrabovsky, M; Huber, D; Huege, T; Insolia, A; Isar, P G; Jansen, S; Jarne, C; Josebachuili, M; Kadija, K; Kambeitz, O; Kampert, K H; Karhan, P; Kasper, P; Katkov, I; Kegl, B; Keilhauer, B; Keivani, A; Kemp, E; Kieckhafer, R M; Klages, H O; Kleifges, M; Kleinfeller, J; Knapp, J; Krause, R; Krohm, N; Kroemer, O; Kruppke-Hansen, D; Kuempel, D; Kunka, N; La Rosa, G; LaHurd, D; Latronico, L; Lauer, R; Lauscher, M; Lautridou, P; Coz, S Le; Leao, M S A B; Lebrun, D; Lebrun, P; de Oliveira, M A Leigui; Letessier-Selvon, A; Lhenry-Yvon, I; Link, K; Lopez, R; Aguera, A Lopez; Louedec, K; Bahilo, J Lozano; Lu, L; Lucero, A; Ludwig, M; Lyberis, H; Maccarone, M C; Macolino, C; Malacari, M; Maldera, S; Maller, J; Mandat, D; Mantsch, P; Mariazzi, A G; Marin, V; Maris, I C; Falcon, H R Marquez; Marsella, G; Martello, D; Martin, L; Martinez, H; Bravo, O Martinez; Martraire, D; Meza, J J Masias; Mathes, H J; Matthews, J; Matthews, J A J; Matthiae, G; Maurel, D; Maurizio, D; Mayotte, E; Mazur, P O; Medina, C; Medina-Tanco, G; Melissas, M; Melo, D; Menichetti, E; Menshikov, A; Messina, S; Meyhandan, R; Micanovic, S; Micheletti, M I; Middendorf, L; Minaya, I A; Miramonti, L; Mitrica, B; Molina-Bueno, L; Mollerach, S; Monasor, M; Ragaigne, D Monnier; Montanet, F; Morales, B; Morello, C; Moreno, J C; Mostafa, M; Moura, C A; Muller, M A; Muller, G; Munchmeyer, M; Mussa, R; Navarra, G; Navarro, J L; Navas, S; Necesal, P; Nellen, L; Nelles, A; Neuser, J; Nhung, P T; Niechciol, M; Niemietz, L; Niggemann, T; Nitz, D; Nosek, D; Novzka, L; Oehlschlager, J; Olinto, A; Oliveira, M; Ortiz, M; Pacheco, N; Selmi-Dei, D Pakk; Palatka, M; Pallotta, J; Palmieri, N; Parente, G; Parra, A; Pastor, S; Paul, T; Pech, M; Pekala, J; Pelayo, R; Pepe, I M; Perrone, L; Pesce, R; Petermann, E; Petrera, S; Petrolini, A; Petrov, Y; Piegaia, R; Pierog, T; Pieroni, P; Pimenta, M; Pirronello, V; Platino, M; Plum, M; Pontz, M; Porcelli, A; Preda, T; Privitera, P; Prouza, M; Quel, E J; Querchfeld, S; Quinn, S; Rautenberg, J; Ravel, O; Ravignani, D; Revenu, B; Ridky, J; Riggi, S; Risse, M; Ristori, P; Rivera, H; Rizi, V; Roberts, J; de Carvalho, W Rodrigues; Cabo, I Rodriguez; Fernandez, G Rodriguez; Martino, J Rodriguez; Rojo, J Rodriguez; Rodriguez-Frias, M D; Ros, G; Rosado, J; Rossler, T; Roth, M; Rouille-d'Orfeuil, B; Roulet, E; Rovero, A C; Ruhle, C; Saffi, S J; Saftoiu, A; Salamida, F; Salazar, H; Greus, F Salesa; Salina, G; Sanchez, F; Sanchez-Lucas, P; Santo, C E; Santos, E; Santos, E M; Sarazin, F; Sarkar, B; Sato, R; Scharf, N; Scherini, V; Schieler, H; Schiffer, P; Schmidt, A; Scholten, O; Schoorlemmer, H; Schovanek, P; Schroeder, F G; Schulz, A; Schulz, J; Sciutto, S J; Scuderi, M; Segreto, A; Settimo, M; Shadkam, A; Shellard, R C; Sidelnik, I; Sigl, G; Sima, O; Smialkowski, A; Smida, R; Snow, G R; Sommers, P; Sorokin, J; Spinka, H; Squartini, R; Srivastava, Y N; Stanic, S; Stapleton, J; Stasielak, J; Stephan, M; Straub, M; Stutz, A; Suarez, F; Suomijarvi, T; Supanitsky, A D; Susa, T; Sutherland, M S; Swain, J; Szadkowski, Z; Szuba, M; Tapia, A; Tartare, M; Tacscuau, O; Tcaciuc, R; Thao, N T; Tiffenberg, J; Timmermans, C; Tkaczyk, W; Peixoto, C J Todero; Toma, G; Tomankova, L; Tome, B; Tonachini, A; Elipe, G Torralba; Machado, D Torres; Travnicek, P; Tridapalli, D B; Trovato, E; Tueros, M; Ulrich, R; Unger, M; Galicia, J F Valdes; Valino, I; Valore, L; van Aar, G; Berg, A M van den; van Velzen, S; van Vliet, A; Varela, E; Cardenas, B Vargas; Varner, G; Vazquez, J R; Vazquez, R A; Veberic, D; Verzi, V; Vicha, J; Videla, M; Villasenor, L; Wahlberg, H; Wahrlich, P; Wainberg, O; Walz, D; Watson, A A; Weber, M; Weidenhaupt, K; Weindl, A; Werner, F; Westerhoff, S; Whelan, B J; Widom, A; Wieczorek, G; Wiencke, L; Wilczynska, B; Wilczynski, H; Will, M; Williams, C; Winchen, T; Wundheiler, B; Wykes, S; Yamamoto, T; Yapici, T; Younk, P; Yuan, G; Yushkov, A; Zamorano, B; Zas, E; Zavrtanik, D; Zavrtanik, M; Zaw, I; Zepeda, A; Zhou, J; Zhu, Y; Silva, M Zimbres; Ziolkowski, M

    2013-01-01

    Joint contributions of the Pierre Auger and Telescope Array Collaborations to the 33rd International Cosmic Ray Conference, Rio de Janeiro, Brazil, July 2013: cross-calibration of the fluorescence telescopes, large scale anisotropies and mass composition.

  9. Pierre Auger Observatory and Telescope Array: Joint Contributions to the 33rd International Cosmic Ray Conference (ICRC 2013)

    NARCIS (Netherlands)

    Telescope Array, The; Pierre Auger Collaborations,; Abu-Zayyad, T.; Allen, M.; Anderson, R.; Azuma, R.; Barcikowski, E.; Belz, J. W; Bergman, D. R.; Blake, S. A.; Cady, R.; Chae, M. J.; Cheon, B. G.; Chiba, J.; Chikawa, M.; Cho, W. R.; Fujii, T.; Fukushima, M.; Goto, K.; Hanlon, W.; Hayashi, Y.; Hayashida, N.; Hibino, K.; Honda, K.; Ikeda, D.; Inoue, N.; Ishii, T.; Ishimori, R.; Ito, H.; Ivanov, D.; Jui, C. C. H.; Kadota, K.; Kakimoto, F.; Kalashev, O.; Kasahara, K.; Kawai, H.; Kawakami, S.; Kawana, S.; Kawata, K.; Kido, E.; Kim, H. B.; Kim, J. H.; Kim, J. H.; Kitamura, S.; Kitamura, Y.; Kuzmin, V.; Kwon, Y. J.; Lan, J.; Lundquist, J. P.; Machida, K.; Martens, K.; Matsuda, T.; Matsuyama, T.; Matthews, J. N.; Minamino, M.; Mukai, K.; Myers, I.; Nagasawa, K.; Nagataki, S.; Nakamura, T.; Nanpei, H.; Nonaka, T.; Nozato, A.; Ogio, S.; Oh, S.; Ohnishi, M.; Ohoka, H.; Oki, K.; Okuda, T.; Ono, M.; Oshima, A.; Ozawa, S.; Park, I. H.; Pshirkov, M. S.; Rodriguez, D. C.; Rubtsov, G.; Ryu, D.; Sagawa, H.; Sakurai, N.; Sampson, A. L.; Scott, L. M.; Shah, P. D.; Shibata, F.; Shibata, T.; Shimodaira, H.; Shin, B. K.; Shirahama, T.; Smith, J. D.; Sokolsky, P.; Springer, R. W.; Stokes, B. T.; Stratton, S. R.; Stroman, T. A.; Takamura, M.; Takeda, M.; Taketa, A.; Takita, M.; Tameda, Y.; Tanaka, H.; Tanaka, K.; Tanaka, M.; Thomas, S. B.; Thomson, G. B.; Tinyakov, P.; Tkachev, I.; Tokuno, H.; Tomida, T.; Troitsky, S.; Tsunesada, Y.; Tsutsumi, K.; Uchihori, Y.; Udo, S.; Urban, F.; Vasiloff, G.; Wada, Y.; Wong, T.; Yamaoka, H.; Yamazaki, K.; Yang, J.; Yashiro, K.; Yoneda, Y.; Yoshida, S.; Yoshii, H.; Zollinger, R.; Zundel, Z.; Aab, A.; Abreu, P.; Aglietta, M.; Ahlers, M.; Ahn, E. J.; Albuquerque, I. F. M.; Allekotte, I.; Allen, J.; Allison, P.; Almela, A.; Alvarez Castillo, J.; Alvarez-Muniz, J.; Alves Batista, R.; Ambrosio, M.; Aminaei, A.; Anchordoqui, L.; Andringa, S.; Antivcic, T.; Aramo, C.; Arqueros, F.; Asorey, H.; Assis, P.; Aublin, J.; Ave, M.; Avenier, M.; Avila, G.; Badescu, A. M.; Barber, K. B.; Bardenet, R.; Baeuml, J.; Baus, C.; Beatty, J. J.; Becker, K. H.; Belletoile, A.; Bellido, J. A.; BenZvi, S.; Berat, C.; Bertou, X.; Biermann, P. L.; Billoir, P.; Blanco, F.; Blanco, M.; Bleve, C.; Blumer, H.; Bohacova, M.; Boncioli, D.; Bonifazi, C.; Bonino, R.; Borodai, N.; Brack, J.; Brancus, I.; Brogueira, P.; Brown, W. C.; Buchholz, P.; Bueno, A.; Burton, R. E.; Buscemi, M.; Caballero-Mora, K. S.; Caccianiga, B.; Caccianiga, L.; Candusso, M.; Caramete, L.; Caruso, R.; Castellina, A.; Cataldi, G.; Cazon, L.; Cester, R.; Cheng, S. H.; Chiavassa, A.; Chinellato, J. A.; Chudoba, J.; Cilmo, M.; Clay, R. W.; Cocciolo, G.; Colalillo, R.; Collica, L.; Coluccia, M. R.; Conceicao, R.; Contreras, F.; Cook, H.; Cooper, M. J.; Coutu, S.; Covault, C. E.; Criss, A.; Cronin, J.; Curutiu, A.; Dallier, R.; Daniel, B.; Dasso, S.; Daumiller, K.; Dawson, B. R.; de Almeida, R. M.; De Domenico, M.; de Jong, S. J.; De La Vega, G.; de Mello Junior, W. J. M.; de Mello Neto, J. R. T.; De Mitri, I.; de Souza, V.; de Vries, K. D.; del Peral, L.; Deligny, O.; Dembinski, H.; Dhital, N.; Di Giulio, C.; Diaz, J. C.; Diaz Castro, M. L.; Diep, P. N.; Diogo, F.; Dobrigkeit, C.; Docters, W.; D'Olivo, J. C.; Dong, P. N.; Dorofeev, A.; dos Anjos, J. C.; Dova, M. T.; Ebr, J.; Engel, R.; Erdmann, M.; Escobar, C. O.; Espadanal, J.; Etchegoyen, A.; Facal San Luis, P.; Falcke, H.; Fang, K.; Farrar, G.; Fauth, A. C.; Fazzini, N.; Ferguson, A. P.; Fick, B.; Figueira, J. M.; Filevich, A.; Filipcic, A.; Foerster, N.; Fox, B. D.; Fracchiolla, C. E.; Fraenkel, E. D.; Fratu, O.; Frohlich, U.; Fuchs, B.; Gaior, R.; Gamarra, R. F.; Gambetta, S.; Garcia, B.; Garcia Roca, S. T.; Garcia-Gamez, D.; Garcia-Pinto, D.; Garilli, G.; Gascon Bravo, A.; Gemmeke, H.; Ghia, P. L.; Giller, M.; Gitto, J.; Glaser, C.; Glass, H.; Gomez Albarracin, F.; Gomez Berisso, M.; Gomez Vitale, P. F.; Goncalves, P.; Gonzalez, J. G.; Gookin, B.; Gorgi, A.; Gorham, P.; Gouffon, P.; Grebe, S.; Griffith, N.; Grillo, A. F.; Grubb, T. D.; Guardincerri, Y.; Guarino, F.; Guedes, G. P.; Hansen, P.; Harari, D.; Harrison, T. A.; Harton, J. L.; Haungs, A.; Hebbeker, T.; Heck, D.; Herve, A. E.; Hill, G. C.; Hojvat, C.; Hollon, N.; Homola, P.; Hoerandel, J. R.; Horvath, P.; Hrabovsky, M.; Huber, D.; Huege, T.; Insolia, A.; Isar, P. G.; Jansen, S.; Jarne, C.; Josebachuili, M.; Kadija, K.; Kambeitz, O.; Kampert, K. H.; Karhan, P.; Kasper, P.; Katkov, I.; Kegl, B.; Keilhauer, B.; Keivani, A.; Kemp, E.; Kieckhafer, R. M.; Klages, H. O.; Kleifges, M.; Kleinfeller, J.; Knapp, J.; Krause, R.; Krohm, N.; Kroemer, O.; Kruppke-Hansen, D.; Kuempel, D.; Kunka, N.; La Rosa, G.; LaHurd, D.; Latronico, L.; Lauer, R.; Lauscher, M.; Lautridou, P.; Le Coz, S.; Leao, M. S. A. B.; Lebrun, D.; Lebrun, P.; Leigui de Oliveira, M. A.; Letessier-Selvon, A.; Lhenry-Yvon, I.; Link, K.; Lopez, R.; Lopez Aguera, A.; Louedec, K.; Lozano Bahilo, J.; Lu, L.; Lucero, A.; Ludwig, M.; Lyberis, H.; Maccarone, M. C.; Macolino, C.; Malacari, M.; Maldera, S.; Maller, J.; Mandat, D.; Mantsch, P.; Mariazzi, A. G.; Marin, V.; Maris, I. C.; Marquez Falcon, H. R.; Marsella, G.; Martello, D.; Martinez, H.; Martinez Bravo, O.; Martraire, D.; Masias Meza, J. J.; Mathes, H. J.; Matthews, J.; Matthews, J. A. J.; Matthiae, G.; Maurel, D.; Maurizio, D.; Mayotte, E.; Mazur, P. O.; Medina, C.; Medina-Tanco, G.; Melissas, M.; Melo, D.; Menichetti, E.; Menshikov, A.; Messina, S.; Meyhandan, R.; Micanovic, S.; Micheletti, M. I.; Middendorf, L.; Minaya, I. A.; Miramonti, L.; Mitrica, B.; Molina-Bueno, L.; Mollerach, S.; Monasor, M.; Monnier Ragaigne, D.; Montanet, F.; Morales, B.; Morello, C.; Moreno, J. C.; Mostafa, M.; Moura, C. A.; Muller, M. A.; Muller, G.; Munchmeyer, M.; Mussa, R.; Navarra, G.; Navarro, J. L.; Navas, S.; Necesal, P.; Nellen, L.; Nelles, A.; Neuser, J.; Nhung, P. T.; Niechciol, M.; Niemietz, L.; Niggemann, T.; Nitz, D.; Nosek, D.; Novzka, L.; Oehlschlager, J.; Olinto, A.; Oliveira, M.; Ortiz, M.; Pacheco, N.; Pakk Selmi-Dei, D.; Palatka, M.; Pallotta, J.; Palmieri, N.; Parente, G.; Parra, A.; Pastor, S.; Paul, T.; Pech, M.; Pekala, J.; Pelayo, R.; Pepe, I. M.; Perrone, L.; Pesce, R.; Petermann, E.; Petrera, S.; Petrolini, A.; Petrov, Y.; Piegaia, R.; Pierog, T.; Pieroni, P.; Pimenta, M.; Pirronello, V.; Platino, M.; Plum, M.; Pontz, M.; Porcelli, A.; Preda, T.; Privitera, P.; Prouza, M.; Quel, E. J.; Querchfeld, S.; Quinn, S.; Rautenberg, J.; Ravel, O.; Ravignani, D.; Revenu, B.; Ridky, J.; Riggi, S.; Risse, M.; Ristori, P.; Rivera, H.; Rizi, V.; Roberts, J.; Rodrigues de Carvalho, W.; Rodriguez Cabo, I.; Rodriguez Fernandez, G.; Rodriguez Martino, J.; Rodriguez Rojo, J.; Rodriguez-Frias, M. D.; Ros, G.; Rosado, J.; Rossler, T.; Roth, M.; Rouille-d'Orfeuil, B.; Roulet, E.; Rovero, A. C.; Ruhle, C.; Saffi, S. J.; Saftoiu, A.; Salamida, F.; Salazar, H.; Salesa Greus, F.; Salina, G.; Sanchez, F.; Sanchez-Lucas, P.; Santo, C. E.; Santos, E.; Santos, E. M.; Sarazin, F.; Sarkar, B.; Sato, R.; Scharf, N.; Scherini, V.; Schieler, H.; Schiffer, P.; Schmidt, A.; Scholten, O.; Schoorlemmer, H.; Schovanek, P.; Schroeder, F. G.; Schulz, A.; Schulz, J.; Sciutto, S. J.; Scuderi, M.; Segreto, A.; Settimo, M.; Shadkam, A.; Shellard, R. C.; Sidelnik, I.; Sigl, G.; Sima, O.; Smialkowski, A.; Smida, R.; Snow, G. R.; Sommers, P.; Sorokin, J.; Spinka, H.; Squartini, R.; Srivastava, Y. N.; Stanic, S.; Stapleton, J.; Stasielak, J.; Stephan, M.; Straub, M.; Stutz, A.; Suarez, F.; Suomijarvi, T.; Supanitsky, A. D.; Susa, T.; Sutherland, M. S.; Swain, J.; Szadkowski, Z.; Szuba, M.; Tapia, A.; Tartare, M.; Tacscuau, O.; Tcaciuc, R.; Thao, N. T.; Tiffenberg, J.; Timmermans, C.; Tkaczyk, W.; Todero Peixoto, C. J.; Toma, G.; Tomankova, L.; Tome, B.; Tonachini, A.; Torralba Elipe, G.; Torres Machado, D.; Travnicek, P.; Tridapalli, D. B.; Trovato, E.; Tueros, M.; Ulrich, R.; Unger, M.; Valdes Galicia, J. F.; Valino, I.; Valore, L.; van Aar, G.; van den Berg, A. M.; van Velzen, S.; van Vliet, A.; Varela, E.; Vargas Cardenas, B.; Varner, G.; Vazquez, J. R.; Vazquez, R. A.; Veberic, D.; Verzi, V.; Vicha, J.; Videla, M.; Villasenor, L.; Wahlberg, H.; Wahrlich, P.; Wainberg, O.; Walz, D.; Watson, A. A.; Weber, M.; Weidenhaupt, K.; Weindl, A.; Werner, F.; Westerhoff, S.; Whelan, B. J.; Widom, A.; Wieczorek, G.; Wiencke, L.; Wilczynska, B.; Wilczynski, H.; Will, M.; Williams, C.; Winchen, T.; Wundheiler, B.; Wykes, S.; Yamamoto, T.; Yapici, T.; Younk, P.; Yuan, G.; Yushkov, A.; Zamorano, B.; Zas, E.; Zavrtanik, D.; Zavrtanik, M.; Zaw, I.; Zepeda, A.; Zhou, J.; Zhu, Y.; Zimbres Silva, M.; Ziolkowski, M.; Martin, L.

    2013-01-01

    Joint contributions of the Pierre Auger and Telescope Array Collaborations to the 33rd International Cosmic Ray Conference, Rio de Janeiro, Brazil, July 2013: cross-calibration of the fluorescence telescopes, large scale anisotropies and mass composition.

  10. Pierre Auger Observatory and Telescope Array: Joint Contributions to the 33rd International Cosmic Ray Conference (ICRC 2013)

    Energy Technology Data Exchange (ETDEWEB)

    Abu-Zayyad, T.; et al.

    2013-10-02

    Joint contributions of the Pierre Auger and Telescope Array Collaborations to the 33rd International Cosmic Ray Conference, Rio de Janeiro, Brazil, July 2013: cross-calibration of the fluorescence telescopes, large scale anisotropies and mass composition.

  11. Microbiological investigation of retrodiscal tissues from patients with advanced internal derangement of the temporomandibular joint.

    Science.gov (United States)

    McIntosh, M; Dimitroulis, G

    2012-03-01

    The aim of this study was to investigate the presence of bacteria in samples of retrodiscal tissues taken from patients suffering from advanced internal derangement of the temporomandibular joint (TMJ). 12 fresh retrodiscal tissue samples were taken from 12 consecutive patients who underwent unilateral TMJ discectomy for advanced TMJ internal derangement (Wilkes stage IV). The retrodiscal tissue samples were stained and cultured for the presence of micro-organisms in microbiology laboratories. No evidence of bacteria or other micro-organisms was found in any of the tissue specimens procured from the TMJ. This study failed to identify the presence of bacteria or other micro-organisms in fresh retrodiscal tissue specimens of the TMJ in patients with advanced TMJ internal derangement.

  12. Correlation between internal derangement and osteoarthrosis in the temporomandibular joint using magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Song, Haeng Un; Choi, Sun Young; Koh, Kwang Joon [School of Dentistry, Chonbuk National University, Jeonju (Korea, Republic of)

    2002-12-15

    To evaluate the relationship between internal derangement and osteoarthrosis in the temporomandibular joint (TMJ) using magnetic resonance imaging (MRI). One hundred and six MR images of TMJs in 53 patients were evaluated. Disc displacements and osseous changes of the TMJs were assessed. Lateral and rotational disc displacements were also evaluated on coronal images. No significant differences in the frequency of osseous changes of the TMJs between disc displacement with reduction and disc displacement without reduction groups were found. The erosion of the condylar head and the sclerosis of the articular eminence were more frequent in the internal derangement group than in the no disc displacement group. The flattening was the most frequently observed osseous change of both the condylar head and articular eminence. The relationship between internal derangement and osteoarthrosis is obscure, but it is thought that both disorders adversely affect each other.

  13. Assessment of government tribology programs

    Energy Technology Data Exchange (ETDEWEB)

    Peterson, M.B.; Levinson, T.M.

    1985-09-01

    An assessment has been made to determine current tribology research and development work sponsored or conducted by the government. Data base surveys and discussions were conducted to isolate current projects sponsored primarily by 21 different government organizations. These projects were classified by subject, objective, energy relevance, type of research, phenomenon being investigated, variables being studied, type of motion, materials and application. An abstract of each project was prepared which included the classification, sponsor, performing organization and a project description. It was found that current work is primarily materials oriented to meet military requirements. Other than the high temperature programs very few of the tribology projects accomplish energy related objectives.

  14. Synergetics and fractals in tribology

    CERN Document Server

    Janahmadov, Ahad Kh

    2016-01-01

    This book examines the theoretical and practical aspects of tribological process using synergy, fractal and multifractal methods, and the fractal and multifractal models of self-similar tribosystems developed on their basis. It provides a comprehensive analysis of their effectiveness, and also considers the method of flicker noise spectroscopy with detailed parameterization of surface roughness friction. All models, problems and solutions are taken and tested on the set of real-life examples of oil-gas industry. The book is intended for researchers, graduate students and engineers specialising in the field of tribology, and also for senior students of technical colleges.

  15. Joint Commission International : novo éthos hospitalar e o empresariamento dos colaboradores

    OpenAIRE

    Roselie Corcini Pinto

    2015-01-01

    A presente dissertação tem por objetivo problematizar discursos que constituem as práticas de Acreditação Hospitalar da Joint Commission International mais especificamente, aquelas enunciações voltadas para a formação/educação e empresariamento dos colaboradores. Baseada nas ideias de Michel Foucault, a pesquisa desenvolve-se na operação de conceitos/ferramentas da governamentalidade e, como constituintes desta, do governamento e da subjetivação. Como superfície de análise, foi utilizada a qu...

  16. Joint implementation, clean development mechanism and tradable permits. International regulation of greenhouse gases

    DEFF Research Database (Denmark)

    Nielsen, L.; Olsen, K.R.

    2000-01-01

    This report deals with international environmental instruments aimed at a cost-effective reduction of greenhouse gas emissions. More precisely the instruments mentioned in the Kyoto Protocol, namely Joint Implementation (JI), the Clean DevelopmentMechanism (CDM) and Tradable Permits (TP...... of the instruments can be organised. The institutional frameworks for JI, CDM and TP are discussed. The report describes how the Kyoto instruments and the Kyotocommitments interact with other instruments and describe distributive effects between countries. It is analysed how the use of CDM may influence...

  17. Tribology for scientists and engineers from basics to advanced concepts

    CERN Document Server

    Menezes, Pradeep L; Ingole, Sudeep P; Kailas, Satish V; Lovell, Michael R

    2013-01-01

    This book describes available tribology technologies and introduces a comprehensive overview of tribology. General, up-to-date knowledge on how tribology is approached in various related areas of research, both experimental and computational is provided.

  18. The Joint International Conference of the XII International Conference on Mechanisms and Mechanical Transmissions (MTM) and the XXIII International Conference on Robotics (Robotics ’16)

    CERN Document Server

    Lovasz, Erwin-Christian; Hüsing, Mathias; Maniu, Inocentiu; Gruescu, Corina

    2017-01-01

    This volume presents the proceedings of the Joint International Conference of the XII International Conference on Mechanisms and Mechanical Transmissions (MTM) and the XXIII International Conference on Robotics (Robotics ’16), that was held in Aachen, Germany, October 26th-27th, 2016. It contains applications of mechanisms and transmissions in several modern technical fields such as mechatronics, biomechanics, machines, micromachines, robotics and apparatus. In connection with these fields, the work combines the theoretical results with experimental testing. The book presents reviewed papers developed by researchers specialized in mechanisms analysis and synthesis, dynamics of mechanisms and machines, mechanical transmissions, biomechanics, precision mechanics, mechatronics, micromechanisms and microactuators, computational and experimental methods, CAD in mechanism and machine design, mechanical design of robot architecture, parallel robots, mobile robots, micro and nano robots, sensors and actuators in ro...

  19. Frictional heating of tribological contacts

    NARCIS (Netherlands)

    Bos, Johannes

    1995-01-01

    Wherever friction occurs, mechanical energy is transformed into heat. The tem­ perature rise associated with this heating can have an important influence on the tribological behaviour of the contacting components. Apart from determining per­ formance, thermal phenomena affect reliability and may cau

  20. Internal derangements of the temporomandibular joint: findings in the pediatric age group

    Energy Technology Data Exchange (ETDEWEB)

    Katzberg, R.W.; Tallents, R.H.; Hayakawa, K.; Miller, T.L.; Goske, M.J.; Wood, B.P.

    1985-01-01

    Findings in 31 pediatric patients with pain and dysfunction of the temporomandibular joint (TMJ) are reported. The average age was 14 years and the average duration of symptoms was 21.4 months. Internal derangements were found in 29 patients (94%) and degenerative arthritis in 13 (42%). In 12 patients (39%), the problem could be traced to an injury to the jaw. Secondary condylar hypoplasia was associated with the meniscal abnormality in 3 patients (10%). Further awareness of internal derangements of the TMJ in the pediatric population should permit greater recognition of their etiology. It is important that threatment be initiated as soon as possible, not only to minimize the development of osseous disease in young adults but also to prevent facial growth deformities.

  1. Adaptive Shape Functions and Internal Mesh Adaptation for Modelling Progressive Failure in Adhesively Bonded Joints

    Science.gov (United States)

    Stapleton, Scott; Gries, Thomas; Waas, Anthony M.; Pineda, Evan J.

    2014-01-01

    Enhanced finite elements are elements with an embedded analytical solution that can capture detailed local fields, enabling more efficient, mesh independent finite element analysis. The shape functions are determined based on the analytical model rather than prescribed. This method was applied to adhesively bonded joints to model joint behavior with one element through the thickness. This study demonstrates two methods of maintaining the fidelity of such elements during adhesive non-linearity and cracking without increasing the mesh needed for an accurate solution. The first method uses adaptive shape functions, where the shape functions are recalculated at each load step based on the softening of the adhesive. The second method is internal mesh adaption, where cracking of the adhesive within an element is captured by further discretizing the element internally to represent the partially cracked geometry. By keeping mesh adaptations within an element, a finer mesh can be used during the analysis without affecting the global finite element model mesh. Examples are shown which highlight when each method is most effective in reducing the number of elements needed to capture adhesive nonlinearity and cracking. These methods are validated against analogous finite element models utilizing cohesive zone elements.

  2. First Chinese public hospital wins Joint Commission International accreditation: the Health Information Department played a key role in the process.

    Science.gov (United States)

    Shaffer, Audrey; Jun, Cheng Li

    2008-07-01

    Sir Run Run Shaw Hospital in Hangzhou, China spent five years preparing for a Joint Commission International accreditation survey. In March 2007 it became the first public hospital on the Chinese mainland to attain international accreditation. The Health Information Department, managed according to Western standards, played an integral role in preparing the hospital for the survey.

  3. Hard and soft tissue imaging of the temporomandibular joint 30 years after diagnosis of osteoarthrosis and internal derangement

    NARCIS (Netherlands)

    deLeeuw, R; Boering, G; vanderKuijl, B; Stegenga, B

    1996-01-01

    Purpose: This article describes the clinical and imaging findings in the temporomandibular joints (TMJs) of patients 30 years after the initial diagnosis of osteoarthrosis and internal derangement. Patients and Methods: Fifty-five TMJs with a history of osteoarthrosis and internal derangement and 37

  4. Web-based tribology design repository system

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Tribology design is one of the most important parts of mechanical product design as thestrength design. Unfortunately, because tribology design knowledge is often m ulti-disciplinary,complicated and piecemeal, it is therefore difficult for a mechanical designer to capture the neededtribology design knowledge. The concept of tribology design repository is proposed in this paper totry to address this problem. This paper presents an object-oriented knowledge representation lan-guage based on the modeling of tribology design component and it makes the complicated tribol-ogy knowledge represented has such advantages as inheritance, encapsulation, and consistency.A web-based triblogy design repository is then established and it enables the edition, retrieve,sharing and reuse of corporate tribology design knowledge in the repository from the Internet.

  5. Researches and developments of biomimetics in tribology

    Institute of Scientific and Technical Information of China (English)

    DAI Zhendong; TONG Jin; REN Luquan

    2006-01-01

    Animals and plants have developed optimal geometric structures, smart topological materials and multi-functional surface textures with excellent tribological characteristics through the evolution of thousand millions of years and become models for tribological design. This paper puts forward the definition and fundament of biomimetic tribology, investigates the status of self-cleaning of liquid-solid interface, adhesion between animals' feet and solid surface, wear characteristics of biological surfaces and biomimetic design, as well as the friction and bionic design on liquid-solid interface. The further developments of the tribological biomimetics are discussed.

  6. Materials and surface engineering in tribology

    CERN Document Server

    Takadoum, Jamal

    2010-01-01

    This title is designed to provide a clear and comprehensive overview of tribology. The book introduces the notion of a surface in tribology where a solid surface is described from topographical, structural, mechanical, and energetic perspectives. It also describes the principal techniques used to characterize and analyze surfaces. The title then discusses what may be called the fundamentals of tribology by introducing and describing the concepts of adhesion, friction, wear, and lubrication. The book focuses on the materials used in tribology, introducing the major classes of materials used, ei

  7. [THE MANIFESTATIONS OF THE PATHOLOGICAL CHANGES OF THE INTERNAL ORGANS IN PATIENTS WITH DISEASES OF TEMPOROMANDIBULAR JOINT].

    Science.gov (United States)

    Volovar, O S

    2015-01-01

    The results of a survey of 248 patients (mean age--26.0 years +/- 7.4 years), from which 222 patients (mean age--26.3 years +/- 8.0 years) with diseases of temporomandibular joint. Identified and visceral connection between the local changes in the iris, the state of the body's connective tissue, the presence of visceral disease (cardiovascular, respiratory, digestive, urinary system), diseases of the temporomandibular joints. Key words: temporomandibular joint, connective tissue, iris, iridodiagnostic, internal organs, concomitant diseases, topical. diagnostics.

  8. Ion plated gold films: Properties, tribological behavior and performance

    Science.gov (United States)

    Spalvins, Talivaldis

    1987-01-01

    The glow discharge energizing favorably modifies and controls the coating/substrate adherence and the nucleation and growth sequence of ion plated gold films. As a result the adherence, coherence, internal stresses, and morphology of the films are significantly improved. Gold ion plated films because of their graded coating/substrate interface and fine uniform densely packed microstructure not only improve the tribological properties but also induce a surface strengthening effect which improves the mechanical properties such as yield, tensile, and fatigue strength. Consequently significant improvements in the tribological performance of ion plated gold films as compared to vapor deposited gold films are shown in terms of decreased friction/wear and prolonged endurance life.

  9. Comparison of MRI findings with clinical symptoms in temporomandibular joint internal derangement

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Ki Jeong [Chonbuk National University College of Medicine, Gwangju (Korea, Republic of)

    2005-06-15

    To determine the clinical correlation of magnetic resonance imaging (MRI) findings of temporomandibular joint internal derangements. The MR images of 150 TMJs in 75 patients were analyzed. The clinical symptoms were pain in the pre auricular area and masticatory muscles and TMJ sounds. There was a statistically significant relationship between the MRI diagnoses of different types of disc displacements and clinical findings of pain, clicking, and crepitus. The risk of TMJ pain was increased when the disc displacement without reduction occurred at the same time in combination with the osteoarthrosis and effusion. Regardless of the results, the data indicate that each of these MR imaging variables may not be regarded as the unique and dominant factor in defining TMJ pain occurrence.

  10. [Hospital Doctors Should Receive Lecture for Sedation According to Joint Commission International].

    Science.gov (United States)

    Ueshima, Hironobu; Komasawa, Nobuyasu; Kitamura, Akira

    2015-08-01

    At our hospital, intending to obtaining an approval from the Joint Commission International (JCI), we conducted a workshop on sedation for all staff physicians. A sedation instructor authorized by the Japanese Association for Medical Simulation gave a lecture using the "practice guidelines for sedation and administration of analgesics for non-anesthesiologists", revised in 2002 by the American Society of Anesthesiologists, following which, a test using 10 true-false questions was conducted, while before and after the lecture a questionnaire survey on the sedation lecture was carried out Among 191 physicians attending the lecture, except for one person, 7 or more questions were answered correctly. From the questionnaires, the sedation lectures were also generally accepted favourably. In the test of understanding, the mistakes were mostly in the sections on "sedation evaluation" "intraoperative monitoring" "pharmaceutical knowledge" and "airway management methods". The sedation lecture in the hospital was effective.

  11. Tribology in secondary wood machining

    Energy Technology Data Exchange (ETDEWEB)

    Ko, P.L.; Hawthorne, H.M.; Andiappan, J.

    1998-07-01

    Secondary wood manufacturing covers a wide range of products from furniture, cabinets, doors and windows, to musical instruments. Many of these are now mass produced in sophisticated, high speed numerical controlled machines. The performance and the reliability of the tools are key to an efficient and economical manufacturing process as well as to the quality of the finished products. A program concerned with three aspects of tribology of wood machining, namely, tool wear, tool-wood friction characteristics and wood surface quality characterization, was set up in the Integrated Manufacturing Technologies Institute (IMTI) of the National Research Council of Canada. The studies include friction and wear mechanism identification and modeling, wear performance of surface-engineered tool materials, friction-induced vibration and cutting efficiency, and the influence of wear and friction on finished products. This research program underlines the importance of tribology in secondary wood manufacturing and at the same time adds new challenges to tribology research since wood is a complex, heterogeneous, material and its behavior during machining is highly sensitive to the surrounding environments and to the moisture content in the work piece.

  12. Tribological Performance of Coated Surfaces

    Institute of Scientific and Technical Information of China (English)

    Kenneth Holmberg; Anssi Laukkanen

    2004-01-01

    The fundamentals of coating tribology is presented in a generalised holistic approach to friction and wear mechanisms of coated surfaces in dry sliding contacts. It is based on a classification of the tribological contact process into macromechanical, micromechanical, tribochemical contact mechanisms and material transfer. The tribological contact process is dominated by the macromechanical mechanisms, which have been systematically analysed by using four main parameters: the coating-to-substrate hardness relationship, the film thickness, the surface roughness and the debris in the contact. In this paper special attention is given to the microlevel mechanisms, and in particular new techniques for modelling the elastic, plastic and brittle behaviour of the surface by finite element (FEM) computer simulations. The contact condition with a sphere sliding over a plate coated with a very thin hard coating is analysed. A three dimensional FEM model has been developed for calculating the first principal stress distribution in the scratch tester contact of a diamond spherical tip moving with increased load on a 2 μm thick titanium nitride (TiN) coated steel surface. The model is comprehensive in that sense that it considers elastic, plastic and fracture behaviour of the contact surfaces. By identifying from a scratch experiment the location of the first crack and using this as input data can the fracture toughness of the coating be determined.

  13. Evaluation of Patient-Oriented Standards of Joint Commission International in Gilan and Mazandaran Teaching Hospitals

    Directory of Open Access Journals (Sweden)

    Ghaseminejhad

    2016-08-01

    Full Text Available Background Medical tourism, a multi-million-dollar industry, has had a significant effect in economic flourishing, creating jobs, and preventing the outflow of currency. Objectives The aim of this study was to evaluate teaching hospitals affiliated to Gilan and Mazandaran University of Medical Sciences, according to joint commission international (JCI standards. Methods This was a descriptive cross sectional study conducted among teaching hospitals affiliated to Gilan and Mazandaran University of Medical Sciences during year 2015. To collect data and evaluate the hospitals, patient-oriented standards of JCI was applied. Results Amongst the eight standards, international patient safety goals (IPSG (with a score of 87.5% had the highest, and patient and family education (PFE (with a score of 53.75% had the lowest score. Hospital “4” with a score of 90.41%, had the highest, and hospital “7” with 58.90%, had the lowest rate of compliance to the standards. According to the Mann-Whitney test, the observed statistics considering a P value of ≤ 0.05 level, was not significant, therefore on a 95% certainty level, there was no significant difference between hospitals in Gilan and Mazandaran, regarding compliance with standards. Overall, the hospitals under study were relatively prepared for attracting medical tourists. Conclusions According to the results, it seems that more planning and implementation of projects is required to strengthen the axes of the joint commission regarding accreditation of hospitals and attraction of medical tourists to these centers, especially foreign tourists. Researchers are recommended to pay special attention to the university of medical sciences of two provinces for the establishment of standards and utilization of professional consultants.

  14. MAGNETIC RESONANCE IMAGING OF THE INTERNALLY DERANGED KNEE JOINT - A PROSPECTIVE STUDY

    Directory of Open Access Journals (Sweden)

    Rangappa Hanumappa

    2013-10-01

    CONCLUSIONS: From these observations, we found that MRI Magnetic resonance imaging is an excellent, non invasive, rad iation free imaging modality with multiplanar capabilities and excellent soft tissue delineation. It can accurately detect, localize and characterize various internal derangements of the knee joint and help in arriving at a correct anatomical diagnosis the reby guiding further management of the patient. KEY WORDS Traumatic knee; MRI; A rthroscopy; IDK

  15. CAS expert receives Tribology Gold Medal

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    Prof. XUE Qunji, a senior expert in tribology from the CAS Lanzhou Institute of Chemical Physics (L1CP) and member of the Chinese Academy of Engineering, received the Tribology Gold Medalfor 2011 on February 27, 2012 in Beijing. As one of the world's most outstanding and influential tribologists in the last forty years, Prof.

  16. Tribology of dental materials: a review

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Z R; Zheng, J [Tribology Research Institute, Key Laboratory for Advanced Technology of Materials of Ministry of Education, Southwest Jiaotong University, Chengdu 610031 (China)], E-mail: zrzhou@home.swjtu.edu.cn

    2008-06-07

    The application of tribology in dentistry is a growing and rapidly expanding field. Intensive research has been conducted to develop an understanding of dental tribology for successful design and selection of artificial dental materials. In this paper, the anatomy and function of human teeth is presented in brief, three types of current artificial dental materials are summarized, and their advantages and disadvantages, as well as typical clinical applications, are compared based on the literature. Possible tribological damage of tooth structure, which is induced by complex interfacial motion, and friction-wear test methods are reported. According to results obtained by the authors and from the literature, the main progress in the area of dental tribology on both natural teeth and artificial dental materials is reviewed. Problems and challenges are discussed and future research directions for dental tribology are recommended. (topical review)

  17. Chondrogenic effect of the perichondrium graft on the internal derangement and osteoarthritis of the temporomandibular joint of the rabbit.

    Science.gov (United States)

    Taylan Filinte, Gaye; Akan, Mithat; Bilgic, Ilker; Karaca, Mustafa; Akoz, Tayfun

    2011-07-01

    Internal derangement of the temporomandibular joint is usually defined as the disruption of the condyle and disc relationship. In addition to this description the other elements of the joint including the cartilage surface, synovial fluid, the ligaments and the bony surface itself demonstrate varying degrees of pathology in concordance with the stage of the internal derangement, as well. This study is designed to create an osteoarthritic model in the rabbit temporomandibular joint. A 2×2mm defect was performed on the cartilage surface of the both condyles of each animal (n=30). The osteoarthritic changes were demonstrated by computerised tomography sections. The right joints of the animals constituted the control group and the left, the study group. At the time of the defect generation, a perichondrium graft from the animal's ear was implanted onto the defect in the study group. The control group was left to heal secondarily. The joints of three randomized groups of 10 animals for each were inspected at the 4th, 6th, and 8th weeks. Cartilage regeneration and regression of the osteoarthritic changes were demonstrated in the study group both in the 6th and 8th week groups. However, the control group showed less cartilage regeneration and progression of the osteoarthritic changes in all weeks, with progression with time. The perichondrium graft has demonstrated chondrogenic effect on the condyle and this in turn changed the progression to internal derangement. Copyright © 2010 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

  18. Arthroscopic disc fixation to the condylar head. Use of resorbable pins for internal derangement of the temporomandibular joint (stage II-IV). Preliminary report of 34 joints.

    Science.gov (United States)

    Goizueta-Adame, Carlos C; Pastor-Zuazaga, Daniel; Orts Bañón, Juan E

    2014-06-01

    The study describes the arthoscopic use of resorbable pins for the internal derangement of the temporomandibular joint with McCain's technique. Clinical and image features are reported retrospectively. Twenty-seven consecutive patients (34 joints) were included. Symptomatic internal derangement and anterior-medial disc displacement with or without reduction in magnetic resonance images (MRI) were diagnosed in all cases. Two resorbable pins (SmartNail) were placed in each joint employing arthroscopic surgery with a third portal for disc recapture and fixation to condylar head. Clinical data 24 months after surgery are reported (movements, pain score, clicking, laterodeviation, occlusal changes). In eight joints a MRI control was required between 1 and 2 years after surgery. Visual analogue scale values (0-100) decreased from 70.8 to 11.9 (p < 0.001) in the first control (week) and kept down after 24 months of follow-up (VAS: 4.8). Movements began to recover in 3 months and mouth opening increased from 34 mm to 43.2 mm 1 year after surgery (p < 0.001). Clicking, laterodeviation and contralateral excursions improvement were statistically significant (p < 0.001). MRI showed disc fixation to condyle head in closed and opened mouth. Disc fixation to condylar head with resorbable pins is a safe and satisfactory procedure. Pain becomes drastically reduced and mandibular function recovers normal parameters in patients with internal derangement. Copyright © 2013 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

  19. PREFACE: International Conference on High Pressure Science and Technology, Joint AIRAPT-22 & HPCJ-50

    Science.gov (United States)

    Viña, Luis; Tejedor, Carlos; Calleja, José M.

    2010-01-01

    The International Joint AIRAPT-22 & HPCJ-50 Conference was held in Odaiba, Tokyo, on 26-31 July 2009. About 480 scientists from 24 countries attended the conference and 464 papers, including 3 plenary lectures, 39 invited talks, and 156 oral presentations, were presented. It is my great pleasure to present this proceedings volume, which is based on the high quality scientific works presented at the conference. The International AIRAPT conference has been held every two years in various countries around the world since 1965, while High Pressure Conference of Japan (HPCJ) has been held annually since 1959 in various Japanese cities. Pressure is a fundamental parameter to control the property of matter. As a result, both AIRAPT and HPCJ have become highly multidisciplinary, and cover Physics, Chemistry, Materials Science, Earth and Planetary Sciences, Biosciences, Food Science, and Technology. Although each discipline has a unique target, they all have high-pressure research in common. This proceedings volume includes about 200 papers of state-of-the-art studies from numerous fields. I hope this proceedings volume provides excellent pieces of information in various fields to further advance high-pressure research. Conference logo Takehiko Yagi Conference Chairman Institute for Solid State Physics The University of Tokyo 7 December 2009 Conference photograph Participants at the conference venue, Tokyo International Exchange Center, Odaiba, Tokyo, Japan. Editor in Chief TAKEMURA Kenichi National Institute for Materials Science, Japan Editorial board Tadashi KONDO Osaka University, Japan Hitoshi MATSUKI The University of Tokushima, Japan Nobuyuki MATUBAYASI Kyoto University, Japan Yoshihisa MORI Okayama University of Science, Japan Osamu OHTAKA Osaka University, Japan Chihiro SEKINE Muroran Institute of Technology, Japan

  20. Effect of tribology processes on adsorption of albumin

    Science.gov (United States)

    Yan, Yu; Yang, Hongjuan; Wang, Linghe; Su, Yanjing; Qiao, Lijie

    2016-03-01

    As soon as artificial joint replacements are implanted into patients, the adsorption of proteins can occur. Joint implants operate in a protein-rich and relatively corrosive environment under tribological contact. The contacted area acted as an anodic part and the rest of the surface was more cathodic. Therefore, the adsorption of proteins is different in and outside the wear track. Adsorbed proteins would denature during rubbing and a tribofilm could form. The tribofilm can lubricate the surface and act as a barrier to corrosion damage. However, to observe the adsorption of proteins in situ has always been a challenge. Scanning Kelvin probe force microscope (SKPFM) was used to study the adsorption of albumin on the surface of CoCrMo alloy under simulated tribology movement. Fluorescence microscopy (FM) was employed to reveal the protein molecules in the wear scar. It was found that albumin molecules can decrease the surface potential and accelerate the corrosion process. In the wear track, albumin denatured and changed the surface potential as time progressed.

  1. Adsorption of albumin on prosthetic materials: implication for tribological behavior.

    Science.gov (United States)

    Serro, A P; Gispert, M P; Martins, M C L; Brogueira, P; Colaço, R; Saramago, B

    2006-09-01

    The orthopedic prosthesis used to substitute damaged natural joints are lubricated by a pseudosynovial fluid that contains biological macromolecules with potential boundary lubrication properties. Proteins are some of those macromolecules whose role in the lubrication process is not yet completely understood. In a previous work, we investigated the influence of the presence of albumin, the major synovial protein, upon the tribological behavior of three of the most used pairs of artificial joint materials: ultra high molecular weight polyethylene (UHMWPE) against counterfaces of alumina, CoCrMo alloy, and 316L stainless steel. Albumin was found to cause a significant decrease in the friction coefficient when the counterfaces were metallic because transfer of UHMWPE was avoided, but this effect was much weaker in the case of alumina. The objective of the present work was to look for an explanation for these differences in tribological behavior in terms of albumin adsorption. With this goal, studies on adsorption of bovine serum albumin (BSA) on the counterface materials, from a biological model fluid (Hanks' balanced salt solution), were carried out using radiolabeled albumin ((125)I-BSA), X-ray photoelectron spectroscopy, and atomic force microscopy. The conclusion from all techniques is that the driving force for albumin adsorption is higher on the metals than on alumina. These results confirm that the greater the amount of protein adsorbed on the counterface, the more efficient is the protection against the transfer of polymeric film to the counterface.

  2. MRI of the internal derangement of temporomandibular joint: Comparison with arthrographic and operation

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Mi Hye; Kim, Dong Ik; Kim, Hyung Gon; Suh, Jung Ho; Jung, Tae Sub [Yonsei University College of Medicine, Seoul (Korea, Republic of)

    1993-07-15

    We retrospectively reviewed the MRI findings of 100 temporomandibular joints in 78 patients who had complained temporomandibular joint dysfunction. MRI findings were classified according to Wilke's staging criteria. And these findings were compared with arthographic findings in 22 joint and surgical findings in 44 joints. According to Wilke's staging, they were classified into 6 stages of abnormality: stage 0 (33 cases), stage I (19 cases), stage II (10 cases), stage III (18 cases), stage IV (6 cases), stage V (14 cases). Among the 22 cases in which arthography and MRI were done, both studies were well correlated in 10 joints. In 7 joints, MRI was superior to arthography, which correctly demonstrated the meniscal displacement in 2 joints and meniscal deformity in 5 joints. In 5 joints, arthography was superior to MR, which demonstrated the perforation (1 joint), adhesion (2 joints) and recapture of meniscus (2 joints). Compared with surgical findings, MRI correctly demonstrated the displacement of meniscus in all 44 joints. However, in case of the 10 meniscal perforation, MRI demonstrated the meniscal discontinuity in only 4 joints. Retrospective MR findings in 10 proven cases were the defect in posterior attachment in 4, far anterior meniscal displacement without recapture in 8, condylar spur in 4, and close bone to bone contact in 1. In conclusion, MRI as a primary diagnostic modality of temporomandibular joint derangement, is superior for the grading of displacement and deformity of meniscus but inferior for the evaluation of perforation, adhesion and recapture of meniscus to conventional arthrography. In case of the suspected meniscal perforation, arthrographic correlation is recommended preoperatively.

  3. Epilepsy and driving: an international perspective. Joint Commission on Drivers' Licensing of the International Bureau for Epilepsy and the International League Against Epilepsy.

    Science.gov (United States)

    Fisher, R S; Parsonage, M; Beaussart, M; Bladin, P; Masland, R; Sonnen, A E; Rémillard, G

    1994-01-01

    Individuals with a history of seizures may be granted driving privileges if the risks of future seizure while driving are relatively low. Different nations have defined these risks in a wide variety of ways. Some countries, e.g., Japan, Greece, Brazil, India, and Russia, preclude driving after a single seizure. Other countries, such as Canada and the United States, allow driving Joint Commission of the International Bureau for Epilepsy/International League Against Epilepsy has summarized regulations in several countries. From a consideration of medical literature and existing practices, a series of proposed guidelines for driving and epilepsy is recommended. In general, these guidelines suggest use of a seizure-free interval, generally 1-2 years but less in particular instances, to determine fitness to drive. Required physician reporting is discouraged, but physicians should report patients whom they believe pose a danger to themselves and to public safety. Individualized consideration should be given to special circumstances that may modify a general driving prohibition. Education and information programs are necessary for medical and regulatory authorities to develop a rational approach to driving and epilepsy worldwide.

  4. Multifunctional materials for tribological applications

    CERN Document Server

    Wood, Robert J K

    2015-01-01

    ""Professor Wood's excellent book is a must-read for all those with an interest in surface engineering and tribology. He has brought together leading experts in their field to produce a comprehensive compilation of topics highly relevant to today's needs. The book will also appeal to non-tribologists, especially engineers and scientists, developing new systems and looking for up-to-date information on advanced materials and coatings.""-Mr. Keith Harrison, The Institute of Materials, Minerals and Mining, UK""A group of well-written, informative ar

  5. Reactive arthritis in relation to internal derangements of the temporomandibular joint: a case control study.

    Science.gov (United States)

    Lund, Bodil; Holmlund, Anders; Wretlind, Bengt; Jalal, Shah; Rosén, Annika

    2015-09-01

    The aim of this study was to find out if reactive arthritis was involved in the aetiology of chronic closed lock of the temporomandibular joint (TMJ) by looking for bacterial antigens in the synovial membrane of the TMJ, and by studying the antibody serology and carriage of human leucocyte antigen (HLA) B27 in patients with chronic closed lock. Patients with reciprocal clicking and healthy subjects acted as controls. We studied a total of 43 consecutive patients, 15 with chronic closed lock, 13 with reciprocal clicking, and 15 healthy controls with no internal derangements of the TMJ. Venous blood samples were collected from all subjects for measurement of concentrations of HLA tissue antigen and serology against Chlamydia trachomatis, Yersinia enterocolitica, Salmonella spp., Campylobacter jejuni, and Mycoplasma pneumoniae. Samples of synovial tissue from patients with closed lock and reciprocal clicking were obtained during discectomy and divided into two pieces, the first of which was tested by strand displacement amplification for the presence of C trachomatis, and the second of which was analysed for the presence of species-specific bacterial DNA using 16s rRNA pan-polymerase chain reaction (PCR). There were no significant differences between the groups in the incidence of antibodies against M pneumoniae, Salmonella spp. or Y enterocolitica. No patient had antibodies towards C trachomatis or C jejuni. We found no bacterial DNA in the synovial fluid from any patient. The HLA B27 antigen was present in 2/15 subjects in both the closed lock and control groups, and none in the reciprocal clicking group. In conclusion, reactive arthritis does not seem to be the mechanism of internal derangement of the TMJ.

  6. Overview of Carbon Dioxide Control Issues During International Space Station/Space Shuttle Joint Docked Operations

    Science.gov (United States)

    Matty, Christopher M.

    2010-01-01

    Crewed space vehicles have a common requirement to remove the carbon dioxide (CO2) created by the metabolic processes of the crew. The space shuttle [Space Transportation System (STS)] and International Space Station (ISS) each have systems in place that allow control and removal of CO2 from the habitable cabin environment. During periods in which the space shuttle is docked to the ISS, known as "joint docked operations," the space shuttle and ISS share a common atmosphere environment. During this period, an elevated amount of CO2 is produced through the combined metabolic activity of the STS and ISS crews. This elevated CO2 production, together with the large effective atmosphere created by collective volumes of the docked vehicles, creates a unique set of requirements for CO2 removal. This paper will describe individual CO2 control plans implemented by STS and ISS engineering teams, as well as the integrated plans used when both vehicles are docked. The paper will also discuss some of the issues and anomalies experienced by both engineering teams.

  7. Surface chemistry and tribology of MEMS.

    Science.gov (United States)

    Maboudian, Roya; Carraro, Carlo

    2004-01-01

    The microscopic length scale and high surface-to-volume ratio, characteristic of microelectro-mechanical systems (MEMS), dictate that surface properties are of paramount importance. This review deals with the effects of surface chemical treatments on tribological properties (adhesion, friction, and wear) of MEMS devices. After a brief review of materials and processes that are utilized in MEMS technology, the relevant tribological and chemical issues are discussed. Various MEMS microinstruments are discussed, which are commonly employed to perform adhesion, friction, and wear measurements. The effects of different surface treatments on the reported tribological properties are discussed.

  8. Joint Antarctic School Expedition - An International Collaboration for High School Students and Teachers on Antarctic Science

    Science.gov (United States)

    Botella, J.; Warburton, J.; Bartholow, S.; Reed, L. F.

    2014-12-01

    The Joint Antarctic School Expedition (JASE) is an international collaboration program between high school students and teachers from the United States and Chile aimed at providing the skills required for establishing the scientific international collaborations that our globalized world demands, and to develop a new approach for science education. The National Antarctic Programs of Chile and the United States worked together on a pilot program that brought high school students and teachers from both countries to Punta Arenas, Chile, in February 2014. The goals of this project included strengthening the partnership between the two countries, and building relationships between future generations of scientists, while developing the students' awareness of global scientific issues and expanding their knowledge and interest in Antarctica and polar science. A big component of the project involved the sharing by students of the acquired knowledge and experiences with the general public. JASE is based on the successful Chilean Antarctic Science Fair developed by Chile´s Antarctic Research Institute. For 10 years, small groups of Chilean students, each mentored by a teacher, perform experimental or bibliographical Antarctic research. Winning teams are awarded an expedition to the Chilean research station on King George Island. In 2014, the Chileans invited US participation in this program in order to strengthen science ties for upcoming generations. On King George Island, students have hands-on experiences conducting experiments and learning about field research. While the total number of students directly involved in the program is relatively small, the sharing of the experience by students with the general public is a novel approach to science education. Research experiences for students, like JASE, are important as they influence new direction for students in science learning, science interest, and help increase science knowledge. We will share experiences with the

  9. How do country risk and national cultural differences between partners affect the survival of international alliances in emerging countries? Longitudinal analysis of 165 international joint ventures in Brazil 1974 to 2005

    Directory of Open Access Journals (Sweden)

    Pierre-Xavier Meschi

    2007-06-01

    Full Text Available This article aims at identifying the individual and joint impact of two « country-level variables », namely national distance and country risk, on the survival of international joint ventures in emerging countries. Research hypotheses predicting the negative impact of national distance and country risk on survival are formulated in this article. These research hypotheses are tested in a sample of 165 international joint ventures that were formed in Brazil between 1974 and 2003. These joint ventures were subjected to an event history analysis over a period of time ranging from 1974 to 2005. The empirical results show that the intercultural dynamics increases the instability of international joint ventures whereas the survival of these alliances does not seem to be affected by the economic and political uncertainty of Brazil. Furthermore, the national distance between local and foreign partners has effects on survival that are variable according to the life cycle of international joint ventures.

  10. On the matter of synovial fluid lubrication: implications for Metal-on-Metal hip tribology.

    Science.gov (United States)

    Myant, Connor; Cann, Philippa

    2014-06-01

    Artificial articular joints present an interesting, and difficult, tribological problem. These bearing contacts undergo complex transient loading and multi axes kinematic cycles, over extremely long periods of time (>10 years). Despite extensive research, wear of the bearing surfaces, particularly metal-metal hips, remains a major problem. Comparatively little is known about the prevailing lubrication mechanism in artificial joints which is a serious gap in our knowledge as this determines film formation and hence wear. In this paper we review the accepted lubrication models for artificial hips and present a new concept to explain film formation with synovial fluid. This model, recently proposed by the authors, suggests that interfacial film formation is determined by rheological changes local to the contact and is driven by aggregation of synovial fluid proteins. The implications of this new mechanism for the tribological performance of new implant designs and the effect of patient synovial fluid properties are discussed.

  11. Tribology of natural fiber polymer composites

    CERN Document Server

    Chand, N

    2008-01-01

    Environmental concerns are driving demand for bio-degradable materials such as plant-based natural fiber reinforced polymer composites. These composites are fast replacing conventional materials in many applications, especially in automobiles, where tribology (friction, lubrication and wear) is important. This book covers the availability and processing of natural fiber polymer composites and their structural, thermal, mechanical and, in particular, tribological properties.Chapter 1 discusses sources of natural fibers, their extraction and surface modification. It also reviews the ther

  12. PREFACE: Theory of Fusion Plasmas, 13th Joint Varenna-Lausanne International Workshop (2012)

    Science.gov (United States)

    Garbet, Xavier; Sauter, Olivier

    2012-12-01

    The 2012 joint Varenna-Lausanne international workshop on the theory of fusion plasmas has been very fruitful. A broad variety of topics were addressed, as usual covering turbulence, MHD, edge physic, RF wave heating and a taste of astrophysics. Moreover the scope of the meeting was extended this year to include the physics of materials and diagnostics for burning plasmas. This evolution reflects the complexity of problems at hand in fusion, in particular in the context of ITER construction. Long-standing problems without immediate consequences have sometimes become an urgent matter in that context. One may quote for instance the choice of plasma facing components or the design of control systems. Another characteristic of the meeting is the interplay between various domains of plasma physics. For instance MHD modes are now currently investigated with gyrokinetic codes, kinetic effects are more and more included in MHD stability analysis, and turbulence is now accounted for in wave propagation problems. This is the proof of cross-fertilization and it is certainly a healthy sign in our community. Finally introducing some novelty in the programme does not prevent us from respecting the traditions of the meeting. As usual a good deal of the presentations were dedicated to numerical simulations. Combining advanced numerical techniques with elaborated analytical theory is certainly a trademark of the Varenna-Lausanne conference, which was respected again this year. The quality and size of the scientific production is illustrated by the 26 papers which appear in the present volume of Journal of Physics: Conference Series, all refereed. We would also like to mention another set of 20 papers to be published in Plasma Physics and Controlled Fusion. We hope the readers will enjoy this special issue of JPCS and the one to come in PPCF. Xavier Garbet and Olivier Sauter October 26, 2012

  13. International Joint Project of Engineering Design Education among Three Institutions in Japan, U.S. and Singapore

    Science.gov (United States)

    Matsuishi, Masakatsu; Takemata, Kazuya; Furukawa, Tetsuro; Sanders, Wayne; Loo, Chin Non

    An international joint program of Engineering Design has started in 2004 between Kanazawa Institute of Technology, Singapore Polytechnic in Singapore, and Rose-Hulman Institute of Technology in the United States. Students from the three institutions worked on the same engineering design project, the main theme of which was, “Bus Transportation/Urban Transportation System in the 21st Century”. Student teams chose their own project themes from specific design areas, which were related to the main theme. Their achievements were unique in their solutions due to the differences in society and culture in Japan, the United States and Singapore, although all the design teams followed the same engineering design procedures. In this paper, the international joint project is discussed in details.

  14. Nano-tribology through molecular dynamics simulations

    Institute of Scientific and Technical Information of China (English)

    WANG; Hui(

    2001-01-01

    [1]Burkert, U., Allinger, N. L., Molecular Mechanics, York: Maple Press Company, 1982.[2]Daw, M. S. , Baskes, M. I., Embedded-atom method: derivation and application to impurities, surface and other defects in metals, Phys. Rev. B, 1984, 29: 6443-6453.[3]Frenke, D., Smit, B., Understanding Molecular Simulation, San Diego: Academic Press, 1996, 60-67, 125-140.[4]Granick, S., Motions and relaxation of confined liquids, Science, 1991, 253: 1374-1379.[5]Koplik, J., Banavar, J., Willemsen, J., Molecular dynamics of Poisewulle flow and moving contact line, Phys. Rev.Lett., 1988, 60: 1282-1285.[6]Hu, Y. Z., Wang, H., Guo, Y. et al., Simulation of lubricant rheology in thin film lubrication, Part I: simulation of Poiseuille flow, Wear, 1996, 196: 243-259.[7]Zou, K., Li, Z. J, Leng, Y. S. et al. , Surface force apparatus and its application in the study of solid contacts, Chinese Science Bulletin, 1999, 44: 268-271.[8]Stevens, M. , Mondello, M., Grest, G. et al. , Comparison of shear flow of hexadecane in a confined geometry and in bulk,J. Chem. Phys., 1997, 106: 7303-7314.[9]Huang, P., Luo, J. B., Wen, S. Z., Theoretical study on the lubrication failure for tthe lubricants with a limiting shear stress, Tribology International, 1999, 32: 421-426.[10]Ryckaert, J. P. , Bellemans. , A molecular dynamics of alkanes, Faraday Soc. , 1978, 66: 95-106.[11]Wang, H. , Hu, Y. Z., A molecular dynamics study on slip phenomenon at solid-liquid interface, in Proceedings of tthe First AICT, Beijing: Tsinghua University Press, 1998, 295-299.[12]Landman, U., Luedtke, W., Burnham, N. et al., Mechanisms and dynamics of adhesion, nanoindentation, and fracture, Science, 1990, 248: 454-461.[13]Leng, Y. S., Hu, Y. Z., Zheng, L. Q., Adhesive contact of flat-ended wedges: theory and computer experiments, Journal of Tribology, 1999, 121: 128-132.

  15. Introduction to the special issue on the 2011 Joint IEEE International Frequency Control Symposium and European Frequency and Time Forum.

    Science.gov (United States)

    Burt, Eric; Gill, Patrick

    2012-03-01

    The 8 invited and 17 contributed papers in this special issue focus on the following topical areas covered at the 2011 Joint IEEE International Frequency Control Symposium and European Frequency and Time Forum, held in San Francisco, California: 1) Materials and Resonators; 2) Oscillators, Synthesizers, and Noise; 3) Microwave Frequency Standards; 4) Sensors and Transducers; 5) Timekeeping and Time and Frequency Transfer; and 6) Optical Frequency Standards.

  16. Student perspectives on the development and evaluation of a joint international education to promote employability in Europe.

    Science.gov (United States)

    Craig, Claire; Piškur, Barbara

    2012-01-01

    This article presents a student evaluation of a joint international education developed as part of a European project which sought to equip health care practitioners with the skills to support employability of individuals furthest removed from the labour market, disadvantaged on account of age, gender, migration or ethnicity. Thirty eight students out of the forty one students that participated in the pilot of four modules (NL, UK, SE, DE) returned completed digital questionnaires (92.6% response rate). The study is descriptive by nature. A questionnaire was used to collect the data from students. Additionally students attending the module in the UK also took part in a series of qualitative interviews which sought to explore their experiences in more detail. These were recorded, transcribed and analyzed. Students reported that joint education facilitates competence development. The competencies they identified (Information Communications Technology) were recognised as being key to enhancing employability of disadvantaged groups. The joint international education exemplified by EEE4all offers one model of how to build a responsive international curriculum to ensure that the workforce of the future is well placed to meet the needs of this changing world.

  17. Esperienza del Laboratorio di Microbiologia e Virologia dell’Ospedale di Trento nell’Accreditamento Joint Commission International

    Directory of Open Access Journals (Sweden)

    Laura Pederzolli

    2007-06-01

    Full Text Available The Accreditation is a standard based process provided by the Joint Commission International (JCI, in order to evaluate the health organization.The aim of this program, according to international standards and indicators, is both to promote and systematically test the continuous improvement of the health care services, with high regard for local needs. The work focuses on analysing the role played by the Microbiology and Virology Laboratory of Trento Hospital within the JCI Accreditation process.We therefore tried to examine and improve its different activities, in compliance with the specific JCI standards.

  18. Tribology needs for future space and aeronautical systems

    Science.gov (United States)

    Fusaro, Robert L.

    1991-01-01

    Future aeronautical and space missions will push tribology technology beyond its current capability. The objective is to discuss the current state of the art of tribology as it is applied to advanced aircraft and spacecraft. Areas of discussion include materials lubrication mechanisms, factors affecting lubrication, current and future tribological problem areas, potential new lubrication techniques, and perceived technology requirements that need to be met in order to solve these tribology problems.

  19. Joint implementation, clean development mechanism and Tradable Permits. International regulation of greenhouse gases

    Energy Technology Data Exchange (ETDEWEB)

    Nielsen, L.; Rose Olsen, K.

    2000-06-01

    A 'correct' accreditation is a key issue when evaluating Joint Implementation as a global environmental instrument. Problems mentioned in the literature on Joint Implementation - including the problem of additionality - are often relating to the problem of defining a correct accreditation. This paper lists some of these problems and lists some of the tools available to solve the reported problems of accreditation. The paper concludes that the institutional framework is crucial in defining what a correct accreditation is. It also concludes that different groups may have different interests in Joint Implementation, and that each of the reported problems may be a problem to some of the Joint Implementation interests groups but not to others. In designing the institutional framework for JI it is important to know the incentives and motivations of the different groups. The main part of the paper is an analysis of the basic incentives and motivations of the different Joint Implementation interest groups. This analysis can be used to weight the problems of Joint Implementation from an environmental perspective and from the perspective of cost effectiveness. (au)

  20. An Audit of Emergency Department Accreditation Based on Joint Commission International Standards (JCI

    Directory of Open Access Journals (Sweden)

    Behrooz Hashemi

    2014-08-01

    Full Text Available Introduction: Despite thousands of years from creation of medical knowledge, it not much passes from founding the health care systems. Accreditation is an effective mechanism for performance evaluation, quality enhancement, and the safety of health care systems. This study was conducted to assess the results of emergency department (ED accreditation in Shohadaye Tajrish Hospital, Tehran, Iran, 2013 in terms of domesticated standards of joint commission international (JCI standards. Methods: This is a cohort study with a four months follow up which was conducted in the ED of Shohadaye Tajrish hospital in December 2013. The standard evaluation check list of Iran hospitals (based on JCI standards included 24 heading and 337 subheading was used for this purpose. The effective possible causes of weak spots were found and their solutions considered. After correction, assessment of accreditation were repeated again. Finally, the achieved results of two periods were analyzed using SPSS version 20. Results: Quality improvement, admission in department and patient assessment, competency and capability test for staffs, collection and analysis of data, training of patients, and facilities had the score of below 50%. The mean of total score for accreditation in ED in the first period was 60.4±30.15 percent and in the second period 68.9±22.9 (p=0.005. Strategic plans, head of department, head nurse, resident physician, responsible nurse for the shift, and personnel file achieved the score of 100%. Of total headings below 50% in the first period just in two cases, collection and analysis of data with growth of 40% as well as competency and capability test for staffs with growth of 17%, were reached to more than 50%. Conclusion: Based on findings of the present study, the ED of Shohadaye Tajrish hospital reached the score of below 50% in six heading of quality improvement, admission in department and patient assessment, competency and capability test for

  1. Tribology of alumina-graphite composites

    Science.gov (United States)

    Yu, Chih-Yuan

    Alumina-graphite composites, which combine high wear resistance and self-lubricity, are a potential and promising candidate for advanced tribological applications. The processing, mechanical properties and tribology of alumina-graphite composites are discussed. Full density is difficult to achieve by a pressureless sintering route. Porosity of the composites increases with graphite content which causes the strength, modulus of elasticity, and hardness of the composites to decrease. The increased porosity does cause the fracture toughness to slightly increases. Tribology of alumina-graphite composites was studied with a pin-on-disk tribometer with emphasis on the following aspects: the graphite content in both pin and disk, the graphite flake size and the orientation of the graphite flakes. Scan electronic microscopy (SEM) and X-ray diffraction are utilized to examine and characterize the wear debris and the worn surface. Results confirmed that it is necessary to optimize the structure and the supply of lubricant to improve the tribological behavior and that the arrangements of sliding couples also affect the tribology of self-lubricated ceramic composites. Continuous measurements of the friction coefficients were collected at high frequency in an attempt to correlate the tribology of alumina-graphite composites to vibrations introduced by friction. While these measurements indicate that the time frequency behavior of tribology is an important area of study, conclusions regarding the frequency response of different sliding couples could not be definitively stated. Finally, a new concept connecting instantaneous wear coefficient and instantaneous contact stress is proposed for prediction of wear behavior of brittle materials.

  2. An International Urogynecological Association (IUGA) / International Continence Society (ICS) Joint Report on the Terminology for Female Pelvic Organ Prolapse (POP)

    NARCIS (Netherlands)

    Haylen, Bernard T; Maher, Christopher F; Barber, Matthew D; Camargo, Sérgio; Dandolu, Vani; Digesu, Alex; Goldman, Howard B; Huser, Martin; Milani, Alfredo L; Moran, Paul A; Schaer, Gabriel N; Withagen, Mariëlla I J

    2016-01-01

    INTRODUCTION: The terminology for female pelvic floor prolapse (POP) should be defined and organized in a clinically-based consensus Report. METHODS: This Report combines the input of members of two International Organizations, the International Urogynecological Association (IUGA) and the Internatio

  3. Tribology in the 80's. Volume 2: Sessions 5 - 8

    Science.gov (United States)

    1984-01-01

    Tender standing and technical advancement of various disciplines and subdisciplines on tribology were discussed. Topics discussed included importance and definition of materials in tribology; directions of research in adhesion and friction; research in wear and wear resistant materials; liquid lubricants and additives; solid lubricants; and tribological materials for mechanical components of the future.

  4. Compositional variation of fibrous callus and joint cartilage in different internal environments

    Institute of Scientific and Technical Information of China (English)

    SUN Xiao-tang; HU Yun-yu; ZHAO Li; L(U) Rong; WANG Jun; BAI Jian-ping

    2006-01-01

    Objective: To evaluate the compositional variation of fibrous callus in the fracture site and the joint cavity and joint cartilage after being transplanted in the muscle pouch.Methods: Thirty 2-month-old New Zealand white rabbits (weighing 1-1.5 kg) were randomly divided into two groups: a callus transplantation group (Group A, n =15) and a cartilage transplantation group ( Group B, n =15). In Group A, closed radius fracture was made and the autologous fibrous callus was transplanted in the right knee joint cavity at 12 days postoperatively. In Group B, the right knee joint cartilage of the animals was transplanted in the autologous back muscle pouches under anesthesia. Then all the animals were killed by overdose anesthetic 3 weeks after transplantation. And the transplanted fibrous callus,the healed bones in the fracture sites and the transplanted joint cartilage were obtained for assessment of compositional variation.Results: Pure fibrous composition was found in the callus at the fracture sites in Group A at 12 days postoperatively. And for 11 out of the 15 animals, the fibrous callus was transformed into cartilaginous tissues after 3 weeks of transplantation, but the fibrous callus was absent in the other 4 animals. The fibrous calluses at the original site and the fracture locus were differentiated into bony tissues. Bony tissue transformation was found in the transplanted joint cartilages in the muscle pouch of all the animals in Group B.Conclusions: The fracture sites or joint cavity may facilitate callus differentiation in different ways: the former is helpful for osteogenesis while the latter for the development and maintenance of cartilages, and the muscle pouch is inclined to induce the osteogenic phenotype for cartilages.

  5. Internal model control of inductive magnetic suspension spherical active joints based on fuzzy neural network inverse system

    Directory of Open Access Journals (Sweden)

    Li Zeng

    2015-11-01

    Full Text Available This article puts forward inductive magnetic suspension spherical active joints and has researched on its mechanism. The expression of motor’s electromagnetic torque is derived from the point of power balance of three-dimensional electromagnetic model, and on the basis of the air gap magnetic flux density distribution, we establish the joint’s mathematical model of electromagnetic levitation force. The relationship between the two of displacement, angle, and current and the transfer function expression of motor system are derived by the state equation and the inverse system theory We established the inverse system of joint’s original system using fuzzy neural network theory and simplified coupling relationship of the motor’s complex multivariable to establish ANFIS model of joint’s inverse system. An internal model controller with high robustness and stability was designed, and an internal model control joint pseudo linear system was built. According to the simulation analysis and experimental verification of the joint control system, the conclusion indicates that the rotor has quick dynamic response and high robustness.

  6. Internal morphology of human facet joints: comparing cervical and lumbar spine with regard to age, gender and the vertebral core.

    Science.gov (United States)

    Wilke, Hans-Joachim; Zanker, Daniel; Wolfram, Uwe

    2012-03-01

    Back pain constitutes a major problem in modern societies. Facet joints are increasingly recognised as a source of such pain. Knowledge about the internal morphology and its changes with age may make it possible to include the facets more in therapeutic strategies, for instance joint replacements or immobilisation. In total, 168 facets from C6/7 and L4/5 segments were scanned in a micro-computed tomography. Image analysis was used to investigate the internal morphology with regard to donor age and gender. Additional data from trabecular bone of the vertebral core allowed a semi-quantitative comparison of the morphology of the vertebral core and the facets. Porosity and pore spacing of the cortical sub-chondral bone does not appear to change with age for either males or females. In contrast, bone volume fraction decreases in females from approximately 0.4 to 0.2 , whereas it is constant in males. Trabecular thickness decreases during the ageing process in females and stays constant in males , whereas trabecular separation increases during the ageing process in both genders. The results of this study may help to improve the understanding of pathophysiological changes in the facet joints. Such results could be of value for understanding back pain and its treatment.

  7. Arthroscopy versus arthrocentesis in the management of internal derangement of the temporomandibular joint: a systematic review and meta-analysis.

    Science.gov (United States)

    Al-Moraissi, E A

    2015-01-01

    The aim of this study was to assess whether arthroscopy or arthrocentesis is most effective and feasible in the management of internal derangement of the temporomandibular joint (TMJ), specifically in relation to joint movement and pain. A comprehensive electronic search without date or language restrictions was performed in January 2014. Inclusion criteria were the following: study in humans; randomized or quasi-randomized controlled trials (RCTs), controlled clinical trials (CCTs), and retrospective studies; comparison of arthrocentesis and arthroscopy in the treatment of internal derangement. Six publications were included in the review, two RCTs, two CCTs, and two retrospective studies. Two studies showed a low risk of bias and four studies showed a moderate risk of bias. There were statistically significant differences between arthrocentesis and arthroscopy with regard to maximal inter-incisal opening and pain reduction, but no difference between the two groups for postoperative complications. The results of this meta-analysis on the management of internal derangement of the TMJ revealed arthroscopy to have superior efficacy to arthrocentesis in increasing joint movement and decreasing pain. Both arthroscopy and arthrocentesis have comparable postoperative complication rates. However, the current meta-analysis is incomplete due to the paucity of good quality studies in the high-impact, peer-reviewed literature; therefore, further better-designed studies are required to address this important question before final conclusions can be drawn as to the true comparative outcomes of TMJ arthrocentesis versus TMJ arthroscopy. Copyright © 2014 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

  8. SHORT-TERM OUTCOME OF ARTHROSCOPIC SURGERY OF TEMPOROMANDIBULAR-JOINT OSTEOARTHROSIS AND INTERNAL DERANGEMENT - A RANDOMIZED CONTROLLED CLINICAL-TRIAL

    NARCIS (Netherlands)

    Stegenga, B; DEBONT, L.G.M.; Dijkstra, P.U.; Boering, G.

    1993-01-01

    Various types of treatment have been proposed for patients with temporomandibular joint (TMJ) osteoarthrosis and internal derangement. We examined the suitability of several assessment instruments developed in previous investigations for treatment-evaluation in a clinical trial comparing arthroscopi

  9. Invited and contributed papers presented by the theory group at the joint Varenna-Lausanne international workshop `theory of fusion plasmas`

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-09-01

    In this report eight invited and contributed papers of the theory group are included which were presented at joint Varenna-Lausanne international workshop on `theory of fusion plasmas`. (author) figs., tabs., refs.

  10. Wind Turbine Tribology Seminar - A Recap

    Energy Technology Data Exchange (ETDEWEB)

    Errichello, R.; Sheng, S.; Keller, J.; Greco, A.

    2012-02-01

    Tribology is the science and engineering of interacting surfaces in relative motion. It includes the study and application of the principles of friction, lubrication, and wear. It is an important phenomenon that not only impacts the design and operation of wind turbine gearboxes, but also their subsequent maintenance requirements and overall reliability. With the major growth and increasing dependency on renewable energy, mechanical reliability is an extremely important issue. The Wind Turbine Tribology Seminar was convened to explore the state-of-the-art in wind turbine tribology and lubricant technologies, raise industry awareness of a very complex topic, present the science behind each technology, and identify possible R&D areas. To understand the background of work that had already been accomplished, and to consolidate some level of collective understanding of tribology by acknowledged experts, the National Renewable Energy Laboratory (NREL), Argonne National Laboratory (ANL), and the U.S. Department of Energy (DOE) hosted a wind turbine tribology seminar. It was held at the Renaissance Boulder Flatiron Hotel in Broomfield, Colorado on November 15-17, 2011. This report is a summary of the content and conclusions. The presentations given at the meeting can be downloaded. Interested readers who were not at the meeting may wish to consult the detailed publications listed in the bibliography section, obtain the cited articles in the public domain, or contact the authors directly.

  11. Mechanical performances of lead-free solder joint connections with applications in the aerospace domain

    Directory of Open Access Journals (Sweden)

    Georgiana PADURARU

    2016-03-01

    Full Text Available The paper presents some theoretical and experimental aspects regarding the tribological performances of lead-free solder joint connections, with application in the aerospace domain. In order to highlight the mechanical and tribological properties of solder joint in correlation with different pad finishes, there were made some mechanical determinations using a dedicated Share Test System. The theoretical model highlights the link between the experimental results and the influence of gravitational acceleration on the mechanical and functional integrity of the electronic assemblies that works in vibration environment. The paper novelty is provided by the interdisciplinary experiment that offers results that can be used in the mechanical, tribological, electronical and aerospace domains.

  12. An International Urogynecological Association (IUGA) / International Continence Society (ICS) Joint Report on the Terminology for Female Pelvic Organ Prolapse (POP).

    Science.gov (United States)

    Haylen, Bernard T; Maher, Christopher F; Barber, Matthew D; Camargo, Sérgio; Dandolu, Vani; Digesu, Alex; Goldman, Howard B; Huser, Martin; Milani, Alfredo L; Moran, Paul A; Schaer, Gabriel N; Withagen, Mariëlla I J

    2016-02-01

    The terminology for female pelvic floor prolapse (POP) should be defined and organized in a clinically-based consensus Report. This Report combines the input of members of two International Organizations, the International Urogynecological Association (IUGA) and the International Continence Society (ICS), assisted at intervals by external referees. Appropriate core clinical categories and a sub-classification were developed to give a coding to definitions. An extensive process of fourteen rounds of internal and external review was involved to exhaustively examine each definition, with decision-making by collective opinion (consensus). A Terminology Report for female POP, encompassing over 230 separate definitions, has been developed. It is clinically-based with the most common diagnoses defined. Clarity and user-friendliness have been key aims to make it interpretable by practitioners and trainees in all the different specialty groups involved in female pelvic floor dysfunction and POP. Female-specific imaging (ultrasound, radiology and MRI) and conservative and surgical managements are major additions and appropriate figures have been included to supplement and clarify the text. Emerging concepts and measurements, in use in the literature and offering further research potential, but requiring further validation, have been included as an appendix. Interval (5-10 year) review is anticipated to keep the document updated and as widely acceptable as possible. A consensus-based Terminology Report for female POP has been produced to aid clinical practice and research. © 2016 Wiley Periodicals, Inc., and The International Urogynecological Association.

  13. The Internal Medicine Subinternship--Now More Important than Ever: A Joint CDIM-APDIM Position Paper.

    Science.gov (United States)

    Vu, T Robert; Angus, S V; Aronowitz, P B; Harrell, H E; Levine, M A; Carbo, A; Whelton, S; Ferris, A; Appelbaum, J S; McNeill, D B; Ismail, N J; Elnicki, D M

    2015-09-01

    For decades, the internal medicine (IM) subinternship has served as a critical interface between undergraduate and graduate medical education. As such, the vast majority of U.S. medical schools offer this rotation to help students prepare for post-graduate training. Historically an experiential rotation, a formal curriculum with specific learning objectives was eventually developed for this course in 2002. Since then, graduate medical education (GME) has changed significantly with the regulation of duty hours, adoption of competency-based education, and development of training milestones and entrustable professional activities. In response to these and many other changes to residency training and medical practice, in 2010, the Association of Program Directors in Internal Medicine (APDIM) surveyed its members-with input from the Clerkship Directors in Internal Medicine (CDIM) Subinternship Task Force-to determine which core skills program directors expected from new medical school graduates. The results of that survey helped to inform a joint CDIM-APDIM committee's decision to re-evaluate the goals of the IM subinternship in an effort to enhance the transition from medical school to residency. This joint committee defined the minimum expectations of what constitutes an IM subinternship rotation, proposed recommended skills for IM subinterns, and discussed challenges and future directions for this crucial course.

  14. Diagnosis and reconstruction of the human temporomandibular joint after trauma or internal derangement.

    Science.gov (United States)

    Bessette, R W; Katzberg, R; Natiella, J R; Rose, M J

    1985-02-01

    This study reviewed the standardized records of 1100 patients with the symptoms of temporomandibular joint syndrome. Of these patients, only 4.5 percent required surgical intervention. The remaining patients were found to have masticatory muscle spasm and were treated by conservative dental methods. Over half the surgical patients had significant macrotrauma to the jaws in their past history. In addition, electromyographic measurement of the masseteric silent period duration in these patients did not reveal muscle spasm. These factors further serve to differentiate the surgical patient from the patient with myofascial pain dysfunction. The patients selected for surgery demonstrated moderate to severe joint disease and required arthroplasty with partial meniscectomy. A surgical technique is presented demonstrating the reconstruction of the meniscus with silicone implant. This same surgical technique is studied in 10 monkeys, and their joints are examined histologically. The results of surgery reveal that 87 percent of the patients reported improvement 1 year after surgery. In all patients complaining of temporomandibular joint clicking or crepitus, surgery produced complete alleviation of these symptoms. The results of surgery were also associated with a 62 percent increase of jaw opening. Histologic evaluation of the human meniscal resections revealed that in addition to an anatomic displacement of the meniscus, there are also significant cellular changes. These changes consisted of calcification, a decrease in cellularity, hyperemia, and a decrease in elastin content.

  15. BITE-FORCE ENDURANCE IN PATIENTS WITH TEMPOROMANDIBULAR-JOINT OSTEOARTHROSIS AND INTERNAL DERANGEMENT

    NARCIS (Netherlands)

    STEGENGA, B; BROEKHUIJSEN, ML; DEBONT, LGM; VANWILLIGEN, JD

    1992-01-01

    The aim of this study was to investigate the potential clinical relevance of testing bite force endurance in patients with articular temporomandibular disorders. The endurance of a 50 N bite force was measured in 51 patients with painful temporomandibular joint disorders. The results were compared t

  16. Tribological performance of nanometer samarium borate

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Nanometer crystal samarium borate with a particle size of 20~40 nm was prepared using replacing solvent drying technique. The wear resistance and load-carrying capacity of 500SN base oil could be improved and the friction coefficient could be decreased by the addition of nanometer samarium borate. But the dosage of samarium borate nanoparticles had to be controlled at a relatively low level, a higher concentration of nanoparticles was not of beneficial to the tribological performance of the oil. The optimal dosage of nanometer samarium borate is 1.0%. Tribochemical reactions took place in the tribological process, which resulted in the formation of deposition products including diboron trioxide and disamarium trioxide. Fe2B and FeB were also found on the wear scar. The improvement of tribological properties of the oil comes from the formation of deposition layer and permeating layer.

  17. Distal radioulnar joint instability (Galeazzi type injury) after internal fixation in relation to the radius fracture pattern.

    Science.gov (United States)

    Korompilias, Anastasios V; Lykissas, Marios G; Kostas-Agnantis, Ioannis P; Beris, Alexandros E; Soucacos, Panayiotis N

    2011-05-01

    The purpose of this study was to classify Galeazzi type injuries and determine the association of residual instability after rigid fixation with the fracture pattern of the shaft of the radius, using a system that is based on anatomic landmarks of the radial shaft. The clinical records of 95 patients (72 men and 23 women) with Galeazzi type injuries requiring open reduction and internal fixation of the fractures were retrospectively reviewed. The mean follow-up was 6.8 years (range, 18 mo to 11 y) after injury. Sixty-nine fractures occurred in the distal third of the radial shaft (type I), 17 fractures were in the middle third (type II), and 9 fractures were in the proximal third of the shaft of the radius (type III). Gross instability of the distal radioulnar joint (DRUJ) was determined intraoperatively by manipulation after radial fixation as compared to the uninjured side. Forty patients had DRUJ instability after internal fixation and were treated with temporary pinning with a K-wire placed transversely proximal to the sigmoid notch. Distal radioulnar joint instability after internal fixation was recorded in 37 type I fractures, 2 type II fractures, and 1 type III fracture. Distal radioulnar joint instability following radial shaft fracture fixation is significantly higher in patients with type I fractures than in patients with type II or type III fractures. The location of the radius fracture can be sufficiently used for preoperative estimation of percentage chance of potential DRUJ instability after fracture fixation. Copyright © 2011 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

  18. Preparation, tribological properties and biocompatibility of fluorinated graphene/ultrahigh molecular weight polyethylene composite materials

    Science.gov (United States)

    Xu, L.; Zheng, Y.; Yan, Z.; Zhang, W.; Shi, J.; Zhou, F.; Zhang, X.; Wang, J.; Zhang, J.; Liu, B.

    2016-05-01

    Fluorinated graphene (FG)/ultra-high molecular weight polyethylene (UHMWPE) composites were successfully prepared by ultrasonic dispersion and liquid thermoforming method. The mechanical and tribological properties of pure UHMWPE and FG/UHMWPE composites were investigated using micro-hardness tester and high-speed reciprocating friction tester. The results showed that: adding FG could not only increase the micro-hardness of the composites, but also decrease the wear volume of the composite significantly. The friction coefficients of the composites were also reduced with the increasing of FG content. In addition, the MC3T3-E1 cells adhered and grew well on the surface of the FG/UHMWPE composites as observed by SEM and fluorescence microscope, indicating the addition of FG did not affect the morphology and activity of the cells. The FG/UHMWPE composites exhibited excellent mechanical properties, tribological properties and biocompatibility, which could be used as the potential artificial joint replacement material.

  19. Micro- and nanoscale phenomena in tribology

    CERN Document Server

    Chung, Yip-Wah

    2011-01-01

    Drawn from presentations at a recent National Science Foundation Summer Institute on Nanomechanics, Nanomaterials, and Micro/Nanomanufacturing, Micro- and Nanoscale Phenomena in Tribology explores the convergence of the multiple science and engineering disciplines involved in tribology and the connection from the macro to nano world. Written by specialists from computation, materials science, mechanical engineering, surface physics, and chemistry, each chapter provides up-to-date coverage of both basic and advanced topics and includes extensive references for further study.After discussing the

  20. The essence and place of the internal audit in the corporate management of a joint stock company

    Directory of Open Access Journals (Sweden)

    Oleksandr Smetanko

    2013-05-01

    Full Text Available The issues related to the revelation of the essence of the internal audit and their places in the corporate management of a joint stock company are raised in the article. The system analysis of the economic literature was conducted, based on which the author’s own point of view on the definition of the internal audit and its treatment in a special economic literature and legal acts of Ukraine is emphasized.The author’s approach to the identification of the internal audit according to the characteristics, based on which it is possible to determine its place in the system of the corporate management, is adduced in the article.Grounded on the research results, a definition of the internal audit is given, allowing to reveal its essence, place and role in the system of corporate management. The definition, proposed in the article, may become the basis of a scientific knowledge on which the internal audit, as a kind of a practical activity, can receive its scientific justification

  1. Intellectual Property Rights, International Joint Ventures and FDI: An Empirical Study

    OpenAIRE

    Thitima Puttitanun

    2006-01-01

    Two types of foreign direct investments (FDI), joint ventures (JVs) and wholly owned affiliates, should be treated separately when studying the influence of intellectual property rights (IPRs) on FDI. Failure to distinguish between types of FDI may explain previously mixed results regarding the effects of IPRs on FDI. Using U.S. affiliates data, we find that JVs and wholly owned affiliates react to a change in IPRs regime differently. In particular, there exists an education threshold level a...

  2. Laboratory studies on the tribology of hard bearing hip prostheses: ceramic on ceramic and metal on metal.

    Science.gov (United States)

    Vassiliou, K; Scholes, S C; Unsworth, A

    2007-01-01

    Total hip replacements offer relief to a great many patients every year around the world. With an expected service life of around 25 years on most devices, and with younger and younger patients undergoing this surgery, it is of great importance to understand the mechanisms of their function. Tribological testing of both conventional and hard bearing joint combinations have been conducted in many centres throughout the world, and, after being initially abandoned owing to premature failures, hard bearing combinations have been revisited as viable options for joint replacements. Improved design, manufacturing procedures, and material compositions have led to improved performance over first-generation designs in both metal-on-metal and ceramic-on-ceramic hip prostheses. This paper offers a review of the work conducted in an attempt to highlight the most important factors affecting joint performance and tribology of hard bearing combinations. The tribological performance of these joints is superior to that of conventional metal- or ceramic-on-polymer designs.

  3. Trends and Visions in Metal Forming Tribology

    DEFF Research Database (Denmark)

    Bay, Niels

    2011-01-01

    Research and development in metal forming tribology is characterized by intensified focus on new tribo-systems such as new lubricants, tool materials and tool coatings in order to substitute environmentally hazardous lubricant systems. Other means to solve these problems include the development...

  4. Tribology: Friction, lubrication, and wear technology

    Science.gov (United States)

    Blau, Peter J.

    1993-01-01

    The topics are presented in viewgraph form and include the following: introduction and definitions of terms; friction concepts; lubrication technology concepts; wear technology concepts; and tribological transitions. This document is designed for educators who seek to teach these concepts to their students.

  5. Joint Commission on International Accreditation workshop: Planning, development and provision of laboratory services.

    Science.gov (United States)

    Karaarslan, Inci

    2009-03-01

    Throughout the world, the oversight of health care quality is accomplished through professionally based accrediting bodies and state regulatory agencies. These organizations set standards or define regulations that address important organizational functions. The Joint Commission, a private sector United States-based non-profit organization, is the forerunner and best known among healthcare accreditation groups. One of the functions assessed by the standards of the JCI Clinical Laboratory Accreditation Program is the planning, development and provision of laboratory services. The standards related to this issue address the necessary processes that should be in place prior to performing patient testing.

  6. Joint Criminal Enterprise: The ICTY’s Contentious Addition to International Law

    DEFF Research Database (Denmark)

    Carlson, Kerstin Bree

    2008-01-01

    The ICTY does not merely represent a historical stage in the development of international criminal justice which can now be put aside and left to legal historians. It also has a lasting impact, due to the fact that its Rules of Procedure and Evidence are judge-made law, tested in the fire of court...... practice and frequently amended to take the latest developments into account. Finally, with the arrest of Slobodan Karadžić, a new chapter has been opened for the Court. This volume thus provides not only an account of all the debates revolving around the proper role of international criminal justice...... and a contribution to the developing academic discipline of “transitional justice”; it also opens up a perspective to the International Criminal Court and asks what procedural legacy the ad hoc tribunals for Yugoslavia and Ruanda provide for the future of international criminal procedure....

  7. Condylar position on the lateral individualized corrected tomography in internal derangement of temporomandibular joint

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Keun Min; Hwang, Eui Hwan; Lee, Sang Rae [College of Dentistry, Kyung Hee University, Seoul (Korea, Republic of)

    2002-06-15

    To examine the possible relationship between condylar position and disk displacement in the temporomandibular joint. 79 temporomandibular joints in 40 patients having temporomandibular disorders were classified into three categories: no disk displacement (NDD), disk displacement with reduction (DDWR), and disk displacement without reduction (DDWOR). Disk positions were assessed from clinical and MRI findings. The relationship between the three categories and condylar positions was evaluated using lateral individualized corrected tomography. Clinical findings regarding the relationship between condyle and disk positions having anterior, centric, and posterior positions were 27%, 27%, and 46%, respectively, in NDD, 43%, 17%, and 40%, respectively, in DDWR, and 44%, 22%, and 34%, respectively, in DDWOR. There were no significant differences in condylar positions between each of the groups (P>0.05). In the relationship between condyle and disk positions with MRI findings, anterior, centric, and posterior positions were 38%, 38%, and 24%, respectively, in NDD, 29%, 21%, and 50%, respectively, in DDWR, and 44%, 9%, and 47% respectively, in DDWOR. There were significant differences in the condylar positions when MRI was utilized (P<0.05). There was a significant correlation between the condyle and disk positions with MRI findings on lateral individualized corrected tomography.

  8. Lubricin immunohistochemical expression in human temporomandibular joint disc with internal derangement.

    Science.gov (United States)

    Leonardi, Rosalia; Almeida, Luis Eduardo; Loreto, Carla

    2011-08-01

    Lubricin is a chondroprotective, mucinous glycoprotein which contribute to joint lubrication, especially to boundary lubrication and maintains joint integrity. The present investigation aimed to study the immunolocalization of lubricin in TMJ discs from patients affected by anterior disc displacement with reduction (ADDwR) ADDwoR. Eighteen TMJ displaced disc affected by ADDwoR were processed immunohistochemically, with a polyclonal anti-lubricin antibody, used at 1:50 working dilution. The percentage of lubricin immunopositive cells (extent score = ES) and the extent of lubricin staining of the disc extracellular matrix (ECM), were evaluated. Each sample was scored for histopathological changes. Percentage of immunostained surface disc cells was the same (ES = 4) in both control and ADDwOR cells, being this data not statistically significant (P  0.05). The extracellular matrix (ECM) of discs at the disc surfaces of both pathological and normal specimens was very heavily stained (++++). Both the ES and ECM staining were not statistically correlated to the TMJ degeneration score according to the Spearman's rank correlation coefficient. According to our findings, a longstanding TMJ disc injury, affects lubricin expression in the TMJ disc tissue and not its surfaces, moreover, lubricin immunostaining is not correlated to TMJ disc histopathological changes.

  9. Multilateral Biomedical Data Sharing in the One-year Joint US-Russian Mission on the International Space Station

    Science.gov (United States)

    Charles, John B.; Haven, C.; Johnson-Throop, K.; Van Baalen, M.; McFather, J.

    2014-01-01

    The One Year Mission (1YM) by two astronauts on the International Space Station (ISS), starting in March 2015, offers a unique opportunity to expand multilateral collaboration by sharing data and resources among the partner agencies in preparation for planned space exploration missions beyond low Earth orbit. Agreements and protocols will be established for the collection, distribution, analysis and reporting of both research and clinical data. Data will be shared between the agencies sponsoring the investigators, and between the research and clinical medicine communities where common interests are identified. The assignment of only two astronauts, one Russian and the other American, to the 1YM necessitated creativity in bilateral efforts to maximize the biomedical return from the opportunity. Addition of Canadian, European and Japanese investigations make the effort even more integrative. There will be three types of investigations: joint, cross-participation and data-exchange. The joint investigations have US and Russian coprincipal investigators, and the data acquired will be their common responsibility. The other two types must develop data sharing agreements and processes specific to their needs. A multilateral panel of ISS partner space agencies will develop policies for international exchange of scientific information to meet their science objectives and priorities. They will promote archiving of space flight data and will inform each other and the scientific community at large about the results obtained from space life sciences studies. Integration tasks for the 1YM are based on current experience from the ISS and previous efforts on the Russian space station Mir. Closer coordination between international partners requires more common approaches to remove barriers to multilateral resource utilization on the ISS. Greater integration in implementation should increase utilization efficiency to benefit all participants in spaceflight human research. This

  10. The prevalence of erosive osseous changes of the articular eminence in the temporomandibular joint in patients with mandibular prognathism without internal derangement. MR and helical CT findings

    Energy Technology Data Exchange (ETDEWEB)

    Hayashi, Takafumi; Ito, Jusuke; Tanaka, Rei; Koyama, Jun-ichi; Kobayashi, Fukiko [Niigata Univ. (Japan). Graduate School of Medical and Dental Sciences

    2002-06-01

    The aim of this study was to assess the prevalence of erosive osseous changes of the articular eminence in the temporomandibular joint without internal derangement. Sixty joints of 30 consecutive patients with mandibular prognathism were evaluated with both MR imaging and helical CT. On MPR images obtained with helical CT, erosive osseous changes of the articular eminence were observed in 18 joints (30%) of 13 patients. None of the joints studied demonstrated an osseous change in the mandibular condyle. MR imaging failed to detect erosive osseous changes of the articular eminence in all of the joints studied. In conclusion, MPR images obtained with helical CT were of value to detect erosive osseous changes of the articular eminence. (author)

  11. Hybrid diffusive/PVD treatments to improve the tribological resistance of Ti-6Al-4V.

    Science.gov (United States)

    Marin, E; Offoiach, R; Lanzutti, A; Regis, M; Fusi, S; Fedrizzi, L

    2014-01-01

    Titanium alloys are nowadays used for a wide range of biomedical applications thanks to their combination of high mechanical resistance, high corrosion resistance and biocompatibility. Nevertheless, the applicability of titanium alloys is sometimes limited due to their low microhardness and tribological resistance. Thus the titanium alloys cannot be successfully applied to prosthetic joint couplings. A wide range of surface treatments, in particular PVD coatings such as CrN and TiN, have been used in order to improve the tribological behaviour of titanium alloys. However, the low microhardness of the titanium substrate often results in coating failure due to cracks and delamination. For this reason, hybrid technologies based on diffusive treatments and subsequent PVD coatings may improve the overall coating resistance. In this work, conventional PVD coatings of CrN or TiCN, deposited on Titanium Grade 5, were characterized and then combined with a standard thermal diffusive nitriding treatment in order to improve the tribological resistance of the titanium alloys and avoid coating delamination. The different treatments were studied by means of scanning electron microscopy both on the sample surface and in cross-section. In-depth composition profiles were obtained using glow discharge optical emission spectrometry (GDOES) and localized energy dispersive X-ray diffraction on linear scan-lines. The microhardness and adhesion properties of the different treatments were evaluated using Vickers microhardness tests at different load conditions. The indentations were observed by means of SEM in order to evaluate delaminated areas and the crack's shape and density. The tribological behaviour of the different treatments was tested in dry conditions and in solution, in alternate pin-on-flat configuration, with a frequency of 0.5 Hz. After testing, the surface was investigated by means of stylus profilometry and SEM both on the surface and in cross-section. The standalone PVD

  12. Hospital for joint diseases participates in international spine registry Spine Tango after successful pilot study.

    Science.gov (United States)

    Röder, Christoph; Errico, Thomas J; Spivak, Jeffrey M; Murray, M; Protopsaltis, T; Lis, A; Nordin, Margareta; Bendo, John

    2012-01-01

    Spine Tango is currently the only international spine registry in existence. It was developed under the auspices of Eurospine, the Spine Society of Europe, and is hosted at the University of Bern, Switzerland. The HJD Spine Center successfully tested Spine Tango during a 3-month pilot study and has since expanded documentation activities to more surgeons. Workflow integration and dedicated research staff are key factors for such an endeavor. Participation enables benchmarking against national and international peers and outcome research and quality assurance of surgical and non-surgical treatments.

  13. Making sense of intercultural interaction processes in international joint venture settings

    DEFF Research Database (Denmark)

    Dao, Li

    the role of individuals and contextual elements as well as process elements which together characterize intercultural interaction. Considering this context, two research questions are set out to guide the research: 1) How do intercultural interaction processes unfold within a Danish-Vietnamese joint...... collection, to develop a pre-understanding framework that serves as a frame of reference for the subsequent field research. The major bodies of literature that the pre-understanding builds on refer to 1) the intercultural interaction stream of research with notable contributions from the negotiated culture...... perspective (Salk, 1997; Brannen, 1998; Brannen and Salk, 2000) and the sensemaking approach to intercultural management (e.g. Osland & Bird, 2000; Kuada & Sørensen, 2010); and 2) process-oriented alliance and IJV research (e.g. Doz 1996, Ring and Van de Ven 1994). The second part (Chapters 7 to 12...

  14. Neglected chaos in international stock markets: Bayesian analysis of the joint return-volatility dynamical system

    Science.gov (United States)

    Tsionas, Mike G.; Michaelides, Panayotis G.

    2017-09-01

    We use a novel Bayesian inference procedure for the Lyapunov exponent in the dynamical system of returns and their unobserved volatility. In the dynamical system, computation of largest Lyapunov exponent by traditional methods is impossible as the stochastic nature has to be taken explicitly into account due to unobserved volatility. We apply the new techniques to daily stock return data for a group of six countries, namely USA, UK, Switzerland, Netherlands, Germany and France, from 2003 to 2014, by means of Sequential Monte Carlo for Bayesian inference. The evidence points to the direction that there is indeed noisy chaos both before and after the recent financial crisis. However, when a much simpler model is examined where the interaction between returns and volatility is not taken into consideration jointly, the hypothesis of chaotic dynamics does not receive much support by the data (;neglected chaos;).

  15. Role of markets, governments and international bodies in joint implementation with the south

    Energy Technology Data Exchange (ETDEWEB)

    Parikh, J.K. [Indira Gandhi Institute of Development Research, Bombay (India)

    1995-11-01

    Joint Implementation (JI) opens up `markets` for carbon emission reduction projects of all cost categories spread throughout the World. Projects commissioned in the developing countries by the Global Environment Facility (GEF) suggest that the cost of CO{sub 2} emissions reductions ranged from US 20 cents per tonne to $42 per tonne on the basis of incremental costs. These costs are much lower than those indicated in the literature referring to the costs in the industrial countries (IC). Even if the costs are similar, the markets for cheaper credits will be widened by the inclusion of more countries. Thus, JI requires a thorough analysis as it could serve as a potential vehicle to reduce greenhouse gas (GHG) emissions in a cost effective manner.

  16. Role of markets, governments and international bodies in joint implementation with the south

    Energy Technology Data Exchange (ETDEWEB)

    Parikh, J.K. [Indira Gandhi Institute of Development Research, Bombay (India)

    1995-11-01

    Joint Implementation (JI) opens up `markets` for carbon emission reduction projects of all cost categories spread throughout the World. Projects commissioned in the developing countries by the Global Environment Facility (GEF) suggest that the cost of CO{sub 2} emissions reductions ranged from US 20 cents per tonne to $42 per tonne on the basis of incremental costs. These costs are much lower than those indicated in the literature referring to the costs in the industrial countries (IC). Even if the costs are similar, the markets for cheaper credits will be widened by the inclusion of more countries. Thus, JI requires a thorough analysis as it could serve as a potential vehicle to reduce greenhouse gas (GHG) emissions in a cost effective manner.

  17. Molecular Dynamic Analysis of Hyaluronic Acid and Phospholipid Interaction in Tribological Surgical Adjuvant Design for Osteoarthritis.

    Science.gov (United States)

    Siódmiak, Jacek; Bełdowski, Piotr; Augé, Wayne K; Ledziński, Damian; Śmigiel, Sandra; Gadomski, Adam

    2017-09-04

    Tribological surgical adjuvants constitute a therapeutic discipline made possible by surgical advances in the treatment of damaged articular cartilage beyond palliative care. The purpose of this study is to analyze interactions between hyaluronic acid and phospholipid molecules, and the formation of geometric forms, that play a role in the facilitated lubrication of synovial joint organ systems. The analysis includes an evaluation of the pathologic state to detail conditions that may be encountered by adjuvants during surgical convalescence. The synovial fluid changes in pH, hyaluronic acid polydispersity, and phospholipid concentration associated with osteoarthritis are presented as features that influence the lubricating properties of adjuvant candidates. Molecular dynamic simulation studies are presented, and the Rouse model is deployed, to rationalize low molecular weight hyaluronic acid behavior in an osteoarthritic environment of increased pH and phospholipid concentration. The results indicate that the hyaluronic acid radius of gyration time evolution is both pH- and phospholipid concentration-dependent. Specifically, dipalmitoylphosphatidylcholine induces hydrophobic interactions in the system, causing low molecular weight hyaluronic acid to shrink and at high concentration be absorbed into phospholipid vesicles. Low molecular weight hyaluronic acid appears to be insufficient for use as a tribological surgical adjuvant because an increased pH and phospholipid concentration induces decreased crosslinking that prevents the formation of supramolecular lubricating forms. Dipalmitoylphosphatidylcholine remains an adjuvant candidate for certain clinical situations. The need to reconcile osteoarthritic phenotypes is a prerequisite that should serve as a framework for future adjuvant design and subsequent tribological testing.

  18. International Students at Chinese Joint Venture Universities: Factors Influencing Decisions to Enrol

    Science.gov (United States)

    Onsman, Andrys

    2013-01-01

    The People's Republic of China has determined to assume a respected place amongst the world's foremost higher education providers. Its short term strategy is multi-pronged: attracting world-class scholars; attracting international students and encouraging Chinese universities to run branches overseas. As well, a small number of select foreign…

  19. TRIBOLOGICAL PROPERTIES AND WEAR MECHANISM OF HARD COATINGS

    OpenAIRE

    Ugues, Daniele; Maizza, Giovanni

    2013-01-01

    In the modern technology, tribologically suitable components and devices are important to increase the energy efficiency. It is possible when one can reduce the friction coefficient and wear of sliding components. The economic effectiveness can be achieved by better tribological system and therefore research in tribology is aimed at minimizing the energy losses resulting from friction and wear. In this view, hard coatings deposited by physical vapor deposition (PVD) are adequate solutions for...

  20. An ex vivo study on immunohistochemical localization of MMP-7 and MMP-9 in temporomandibular joint discs with internal derangement

    Directory of Open Access Journals (Sweden)

    C. Loreto

    2013-04-01

    Full Text Available Internal derangement (ID is among the most common disorders of the temporomandibular joint (TMJ. Previous research by our group highlighted a correlation between apoptosis and TMJ ID. Metalloproteinases (MMP-7 and -9 have been shown to play an important role in extracellular matrix ECM homeostasis and, through it, in joint disc remodelling. The immunohistochemical expression of MMP-7 and -9 was investigated in discs from patients with TMJ ID and from healthy donors and compared with the degree of histological tissue degeneration. The collagen fibre arrangement in pathological discs exhibited varying degrees of disruption. New vessels were consistently detected; endothelial cells from these vessels were immunolabelled with both MMP-7 and MMP-9. More or less intense MMP-7 and MMP-9 immunolabelling was detected in the cytoplasm of disc cells from all patients. MMP-7 and MMP-9 immunostaining was significantly different between pathological and normal discs and correlated with the extent of histopathological degeneration. MMP-7 and MMP-9 upregulation in discs from patients with TMJ ID demonstrates their involvement in disc damage in this disorder. A greater understanding of these processes could help identify ways to curb MMP overproduction without affecting their tissue remodelling action. The design of specific inhibitors for these MMPs would not only help to gain insights into the biological roles of MMPs, but would also aid in developing therapeutic interventions for diseases associated with abnormal ECM degradation.

  1. Application of numerical method in calculating the internal rate of return of joint venture investment using diminishing musyarakah model

    Science.gov (United States)

    Ruslan, Siti Zaharah Mohd; Jaffar, Maheran Mohd

    2017-05-01

    Islamic banking in Malaysia offers variety of products based on Islamic principles. One of the concepts is a diminishing musyarakah. The concept of diminishing musyarakah helps Muslims to avoid transaction which are based on riba. The diminishing musyarakah can be defined as an agreement between capital provider and entrepreneurs that enable entrepreneurs to buy equity in instalments where profits and losses are shared based on agreed ratio. The objective of this paper is to determine the internal rate of return (IRR) for a diminishing musyarakah model by applying a numerical method. There are several numerical methods in calculating the IRR such as by using an interpolation method and a trial and error method by using Microsoft Office Excel. In this paper we use a bisection method and secant method as an alternative way in calculating the IRR. It was found that the diminishing musyarakah model can be adapted in managing the performance of joint venture investments. Therefore, this paper will encourage more companies to use the concept of joint venture in managing their investments performance.

  2. International Joint Conference CISIS’12-ICEUTE´12-SOCO´12 Special Sessions

    CERN Document Server

    Snášel, Václav; Abraham, Ajith; Zelinka, Ivan; Baruque, Bruno; Quintián, Héctor; Calvo, José; Sedano, Javier; Corchado, Emilio

    2013-01-01

    This volume of Advances in Intelligent and Soft Computing contains accepted papers presented at CISIS 2012 and ICEUTE 2012, both conferences held in the beautiful and historic city of Ostrava (Czech Republic), in September 2012. CISIS aims to offer a meeting opportunity for academic and industry-related researchers belonging to the various, vast communities of Computational Intelligence, Information Security, and Data Mining. The need for intelligent, flexible behaviour by large, complex systems, especially in mission-critical domains, is intended to be the catalyst and the aggregation stimulus for the overall event. After a through peer-review process, the CISIS 2012 International Program Committee selected 30 papers which are published in these conference proceedings achieving an acceptance rate of 40%. In the case of ICEUTE 2012, the International Program Committee selected 4 papers which are published in these conference proceedings. The selection of papers was extremely rigorous in order to maintain the ...

  3. Mechanics and tribology of MEMS materials.

    Energy Technology Data Exchange (ETDEWEB)

    Prasad, Somuri V.; Dugger, Michael Thomas; Boyce, Brad Lee; Buchheit, Thomas Edward

    2004-04-01

    Micromachines have the potential to significantly impact future weapon component designs as well as other defense, industrial, and consumer product applications. For both electroplated (LIGA) and surface micromachined (SMM) structural elements, the influence of processing on structure, and the resultant effects on material properties are not well understood. The behavior of dynamic interfaces in present as-fabricated microsystem materials is inadequate for most applications and the fundamental relationships between processing conditions and tribological behavior in these systems are not clearly defined. We intend to develop a basic understanding of deformation, fracture, and surface interactions responsible for friction and wear of microelectromechanical system (MEMS) materials. This will enable needed design flexibility for these devices, as well as strengthen our understanding of material behavior at the nanoscale. The goal of this project is to develop new capabilities for sub-microscale mechanical and tribological measurements, and to exercise these capabilities to investigate material behavior at this size scale.

  4. Tribological characteristics of dental metal biomaterials

    Directory of Open Access Journals (Sweden)

    Walczak Mariusz

    2016-12-01

    Full Text Available The paper is a report of the examination of the tribological wear characteristics of certain dental metal biomaterials. In the study, tests were undertaken on the following materials: 316L steel, NiCrMo alloy, technically pure titanium (ASTM-grade 2 and Ti6Al4V ELI alloy (ASTM-grade 5. The tribological tests were performed in artificial saliva to determine the coefficient of friction and wear factor; the traces of wear were then ascertained through SEM. The significance of variations in the wear factor, was subsequently assessed by the U Mann-Whitney test. The resistance to wear in the ball-on-disc test under in vitro conditions was observed for the tested materials in the following order: NiCrMo>316L>Ti6Al4V>Ti grade 2.

  5. Status of Plasma Physics Techniques for the Deposition of Tribological Coatings

    Science.gov (United States)

    Spalvins, T.

    1984-01-01

    The plasma physics deposition techniques of sputtering and ion-plating are reviewed. Their characteristics and potentials are discussed in terms of synthesis or deposition of tribological coatings. Since the glow discharge or plasma generated in the conventional sputtering and ion-plating techniques has a low ionization efficiency, rapid advances have been made in equipment design to further increase the ionization efficiency. The enhanced ionization favorably affects the nucleation and growth sequence of the coating. This leads to improved adherence and coherence, higher density, favorable morphological growth, and reduced internal stresses in the coatings. As a result, desirable coating characteristics can be precision tailored. Tribological coating characteristics of sputtered solid film lubricants such as MoS2, ion-plated soft gold and lead metallic films, and sputtered and ion-plated wear-resistant refractory compound films such as nitrides and carbides are discussed.

  6. Global Tribology Research Output (1998 - 2012: A Macro Level Scientometric Study

    Directory of Open Access Journals (Sweden)

    Elango, B.

    2015-12-01

    Full Text Available The aim of this study is to compare country output and citation impact as well as to assess the level of interdisciplinarity in the field of tribology research during the period 1998-2012, based on the SCOPUS database. Macro-level scientometric indicators such as growth rate, share of international collaborative papers, citation per paper, share of un-cited papers, and publication efficiency index were employed. Further, the Simpson Index of Diversity was used to measure the level of interdisciplinarity. The performance of top countries contributing more than 1000 papers during the study period was discussed. Contributions and share of continents and countries by income groups were examined. Further research contributions and citation impact of selected country groups were analyzed. This study reveals that high levels of interdisciplinarity exist in tribology research. Asia outperforms the other world regions and China contributes most of the papers (25%, while the United States receives most of the citations (22%.

  7. Tribological characterization of selected hard coatings

    OpenAIRE

    Karlsson, Patrik

    2009-01-01

    Hard coatings are often used for protection of tool surfaces due to coating properties like low friction and high wear resistance. Even though many of the hard coatings have been tested for wear, it is important to try new wear test setups to fully understand tribological mechanisms and the potential of hard coatings. Few experiments have been performed with dual-coated systems where the sliding contact surfaces are coated with the same, or different, hard coating. The dual-coated system coul...

  8. Advanced tribology design tools for space mechanisms

    Science.gov (United States)

    Roberts, E. W.; Lewis, S. D.

    2001-09-01

    The purpose of this paper is to report on the current status of, and updates to, three well-established ESTL/TM design aids and tools which are frequently used in the design of spacecraft mechanisms. The design aids covered are: - Space Tribology Handbook - DOLLS: a database on space oils and greases - CABARET: a ball bearing analysis code. The Space Tribology Handbook has become established as the definitive guide to space tribology. This paper reports on updates made to the Handbook and the plans to incorporate it into ECSS Guidelines. The database known as DOLLS provides the fundamental information needed for selection of a fluid lubricant for space applications. The database is being upgraded to include details on new oils and greases and, where available, new data on the characteristics of listed fluid lubricants. The bearing analysis code, CABARET, allows the prediction of bearing performance for a range of applications from low-speed mechanisms to high-speed turbo-pumps. Its predictive capabilities include torque, contact stress, stiffness thermal effects, cage motion, and fatigue life. Each design aid and its current status are discussed further.

  9. An Unexplored Facet of International Business in Greece: Foreign and Diaspora Shareholders in Joint Stock Company Start-Ups, 1833-1920

    Directory of Open Access Journals (Sweden)

    Ioanna Sapfo Pepelasis

    2016-07-01

    Full Text Available This paper focuses on an unexplored aspect of the history of international business in Greece, the presence of international shareholders in Greek Joint stock company start-ups. Our main findings are that these investors participated in numerous such firms usually as minority shareholders in capital and or knowledge intensive firms. Rarely did they opt for the exclusive international ownership of a joint stock company in Greece and the dividing line  between foreign direct investment and foreign portfolio investment was not always clear. It is also the case that international capital inflow into the nascent corporate sector involved a mosaic of collaborating actors including not only the foreign but also the diasporic.

  10. Report on the SNL/AWE/NSF international workshop on joint mechanics, Dartington, United Kingdom, 2729 April 2009.

    Energy Technology Data Exchange (ETDEWEB)

    Ewins, David J. (University of Bristol, UK); Bergman, Lawrence A. (University of Illinois, Urbana, IL); Segalman, Daniel Joseph

    2010-08-01

    The SNL/AWE joint mechanics workshop, held in Dartington Hall, Totnes, Devon, UK 26-29 April 2009 was a follow up to another international joints workshop held in Arlington, Virginia, in October 2006. The preceding workshop focused on identifying what length scales and interactions would be necessary to provide a scientific basis for analyzing and understanding joint mechanics from the atomistic scale on upward. In contrast, the workshop discussed in this report, focused much more on identification and development of methods at longer length scales that can have a nearer term impact on engineering analysis, design, and prediction of the dynamics of jointed structures. Also, the 2009 meeting employed less technical presentation and more break out sessions for developing focused strategies than was the case with the early workshop. Several 'challenges' were identified and assignments were made to teams to develop approaches to address those challenges.

  11. DOE-OTM Tribology Program; Quarterly progress report, January 1991--March 1991

    Energy Technology Data Exchange (ETDEWEB)

    Nichols, F. A.; Michaels, A. I. [eds.

    1991-07-01

    The OTM Tribology Program supports generic, long-term, high-risk applied research and exploratory development which private enterprise will not or cannot pursue, in areas pertaining to energy conservation in the transportation sector. This report presents work in the three areas of the tribology program: extreme environment lubrication, engineered tribological interfaces, and tribology by design.

  12. International scientific seminar «Chronicle of Nature – a common database for scientific analysis and joint planning of scientific publications»

    Directory of Open Access Journals (Sweden)

    Juri P. Kurhinen

    2016-05-01

    Full Text Available Provides information about the results of the international scienti fic seminar «Сhronicle of Nature – a common database for scientific analysis and joint planning of scientific publications», held at Findland-Russian project «Linking environmental change to biodiversity change: large scale analysis оf Eurasia ecosystem».

  13. BioSTEC 2017: 10th International Joint Conference on Biomedical Engineering Systems and Technologies : Proceedings Volume 5: HealthInf

    NARCIS (Netherlands)

    2017-01-01

    This book contains the proceedings of the 10th International Joint Conference on Biomedical Engineering Systems and Technologies (BIOSTEC 2017). This conference is sponsored by the Institute for Systems and Technologies of Information, Control and Communication (INSTICC), in cooperation with the ACM

  14. Symposium introduction: the first joint American Chemical Society Agricultural and Food Chemistry Division and the American Chemical Society International Chemical Sciences Chapter in Thailand

    Science.gov (United States)

    The American Chemical Society (ACS) Agricultural and Food Chemistry Division (AGFD) and the ACS International Chemical Sciences Chapter in Thailand (ICSCT) worked together to stage the “1st Joint ACS AGFD - ACS ICSCT Symposium on Agricultural and Food Chemistry,” which was held in Bangkok, Thailand ...

  15. A System of Test Methods for Sheet Metal Forming Tribology

    DEFF Research Database (Denmark)

    Bay, Niels; Olsson, David Dam; Andreasen, Jan Lasson

    2007-01-01

    Sheet metal forming of tribologically difficult materials such as stainless steel, Al-alloys and Ti-alloys or forming in tribologically difficult operations like ironing, punching or deep drawing of thick plate requires often use of environmentally hazardous lubricants such as chlorinated paraffin...

  16. International Space Station Solar Alpha Rotary Joint Failure Analysis: The Materials and Processes Perspective

    Science.gov (United States)

    Dasgupta, Rajib; Figert, John; Jerman, Greg; Wright, Clara; Basta, Erin A.; Golden, Johnny L.

    2009-01-01

    This paper summarizes the on-orbit structural dynamic data and the related modal analysis, model validation and correlation performed for the ISS configurations spanning ISS Stage 12A. The objective of this analysis is to validate and correlate analytical models used to verify the ISS critical interface dynamic loads and improve its fatigue life prediction. On-Orbit dynamic responses were measured during the ISS configurations throughout ISS Stage 12A by the two main ISS instrumentation systems; Internal Wireless Instrumentation System (IWIS) and the Structural Dynamic Measurement System (SDMS). These nominal on-orbit events include Russian vehicle docking and undockings. Also, the ISS photogrammetric system recorded the movements of the 2A and 4A solar arrays during a modified ISS maneuver. Modal analyses were performed on the measured data to extract modal parameters including frequency, damping and mode shapes. Correlation and comparisons between the test and analytical frequencies and mode shapes were performed to assess the accuracy of the analytical models for the ISS configurations under consideration.

  17. TOPICAL REVIEW: Tribology of dental materials: a review

    Science.gov (United States)

    Zhou, Z. R.; Zheng, J.

    2008-06-01

    The application of tribology in dentistry is a growing and rapidly expanding field. Intensive research has been conducted to develop an understanding of dental tribology for successful design and selection of artificial dental materials. In this paper, the anatomy and function of human teeth is presented in brief, three types of current artificial dental materials are summarized, and their advantages and disadvantages, as well as typical clinical applications, are compared based on the literature. Possible tribological damage of tooth structure, which is induced by complex interfacial motion, and friction-wear test methods are reported. According to results obtained by the authors and from the literature, the main progress in the area of dental tribology on both natural teeth and artificial dental materials is reviewed. Problems and challenges are discussed and future research directions for dental tribology are recommended.

  18. PREFACE: 2013 Joint IMEKO (International Measurement Confederation) TC1-TC7-TC13 Symposium: Measurement Across Physical and Behavioural Sciences

    Science.gov (United States)

    Battista Rossi, Giovanni; Crenna, Francesco; Belotti, Vittorio

    2013-09-01

    The 2013 Joint IMEKO (International Measurement Confederation) TC1-C7-TC13 was organised by the University of Genova - DIME/MEC, Measurement Laboratory, Italy, on 4-6 September 2013. The work of this symposium is reported in this volume. The scope of the symposium includes the main topics covered by the above Technical Committees: TC1 Education and Training in Measurement and Instrumentation TC7 Measurement Science TC13 Measurements in Biology and Medicine This is in keeping with the tradition set by the previous events of this well established series. There has been a special focus on measurement across physical and behavioural sciences, with the aim of highlighting the interdisciplinary character of measurement science and of promoting constructive interactions with scientists in other disciplines. The discussion was introduced by keynote lectures on measurement challenges in psychophysics, psychometrics and quantum physics. The symposium was attended by experts working in these areas from 18 countries, including USA, Australia and Japan, and provided a useful forum for them to share and exchange their work and ideas. In total over sixty papers are included in the volume, organised according to the presentation sessions. Each paper was independently peer-reviewed by two reviewers from a distinguished international panel. The Symposium was held in Genova, which was the European Capital of Culture in 2004, and took place in Palazzo Ducale, an important historical building whose construction started in the 13th century, and that has been the house of the Duke of Genova from the 14th century. Genova, whose name comes from the Latin word 'Janua' (meaning 'door', as January is the door month of the year), has been regarded over the centuries as a door connecting Europe with the different countries and cultures of the Mediterranean basin and thus was an appropriate site for an international symposium involving different and new scientific visions and approaches to

  19. Correlation between Eminence Steepness and Condyle Disk Movements in Temporomandibular Joints Affected by Internal Derangements Using Magnetic Resonance Imaging

    Directory of Open Access Journals (Sweden)

    Nilofar Mofidi

    2013-02-01

    Full Text Available Background and Aims: Internal derangement of the Temporomandibular joint (TMJ is the most common form of Temporomandibular disorders, which represents an abnormal internal strucural and functional change of the disk, as well as an abnormal relationship of the disk to the condyle, glenoid fossa and articular eminence when the teeth are in the closed- mouth position. The aim of this study was to evaluate the correlation between eminence steepness and condyle disk movements in TMJs affected by internal derangements using magnetic resonance imaging (MRI. Materials and Methods: In this cross-sectional study, digital MRI files of 90 joints belong to 45 patients in open and closed-mouth positions were evaluated. Patients were subdivided into two groups: 64 individuals with anterior diskdisplacement with reduction and 26 individuals with anterior disk displacement without reduction. Appropriate oblique sagittal sections were selected and printed. Outlines of the fossa, eminence, condyle and disk were traced on matte acetate sheets and evaluated by an oral and maxillofacial radiologist and a postgraduate student of oral and maxillofacial radiology. Disk rotation, condyle rotation, condyle translation and eminence steepness were measured.The data were analyzed using T-test.Results: In this study, no significant difference was found in measurements between the two groups, (for steepness P=0.64, for Disc rotation P=0.77, for condyle rotation P=0.28 and for condyle translation P=0.12. Disk rotation showed statistically significant correlation with eminence steepness in the anterior disk displacement with reduction group 34 .Although this correlation was weak (r=0.27 (P>0.05. No statistically significant correlations were found between other variables and eminence steepness in this group (for condyle rotation P=0.3 and for condyle translation P=0.98. Disk rotation and condyle translation had statistically significant relationship in the anterior disk

  20. Increase in Total Joint Arthroplasty Projected from 2014 to 2046 in Australia: A Conservative Local Model With International Implications.

    Science.gov (United States)

    Inacio, Maria C S; Graves, Stephen E; Pratt, Nicole L; Roughead, Elizabeth E; Nemes, Szilard

    2017-08-01

    The incidence of joint arthroplasty is increasing worldwide. International estimates of future demand for joint arthroplasty have used models that propose either an exponential future increase, despite obvious system constraints, or static increases, which do not account for past trends. Country-specific projection estimates that address limitations of past projections are necessary. In Australia, a high-income country with the 7th highest incidence of TKA and 15th highest incidence of THA of the Organization for Economic Cooperation and Development (OECD) countries, the volume of TKAs and THAs increased 198% between 1994 and 2014. To determine the projected incidence and volume of primary TKAs and THAs from 2014 to 2046 in the Australian population older than 40 years. Australian State and Territory Health Department data were used to identify TKAs and THAs performed between 1994 and 1995 and 2013 and 2014. The Australian Bureau of Statistics was the source of the population estimates for the same periods and population-projected estimates until 2046. The incidence rate (IR), 95% CI, and prediction interval (PI) of TKAs and THAs per 100,000 Australian citizens older than 40 years were calculated. Future IRs were estimated using a logistic model, and volume was calculated from projected IR and population. The logistic growth model assumes the existence of an upper limit of the TKA and THA incidences and a growth rate directly related to this incidence. At the beginning, when the observed incidence is much lower than the asymptote, the increase is exponential, but it decreases as it approaches the upper limit. A 66% increase in the IR of primary THAs between 2013 and 2046 is projected for Australia (2013: IR = 307 per 100,000, [95% CI, 262-329 per 100,000] compared with 2046: IR= 510 per 100,000, [95% PI, 98-567 per 100,000]), which translates to a 219% increase in the volume during this period. For TKAs the IR is expected to increase by 26% by 2046 (IR = 575 per

  1. Validation of a New Pediatric Joint Scoring System From the International Hemophilia Prophylaxis Study Group: Validity of the Hemophilia Joint Health Score

    NARCIS (Netherlands)

    Feldman , M. Brian; Funk, M. Sharon; Bergstrom, Britt-Marie; Zourikian, Nichan; Hillard, Pamela; Net, van der Janjaap; Engelbert , H.H. Raoul; Petrini, Pia; Berg, Marijke van den H.; Manco-Johnson, J. Marilyn; Rivard, E. Georges; Abad, Audrey; Blanchette , S. Victor

    2011-01-01

    Objective. Repeated hemarthrosis in hemophilia causes arthropathy with pain and dysfunction. The Hemophilia Joint Health Score (HJHS) was developed to be more sensitive for detecting arthropathy than the World Federation of Hemophilia (WFH) physical examination scale, especially for children and tho

  2. Concepts in mature T-cell lymphomas - highlights from an international joint symposium on T-cell immunology and oncology().

    Science.gov (United States)

    Herling, Marco; Rengstl, Benjamin; Scholtysik, René; Hartmann, Sylvia; Küppers, Ralf; Hansmann, Martin-Leo; Diebner, Hans H; Roeder, Ingo; Abken, Hinrich; Newrzela, Sebastian; Kirberg, Jörg

    2017-04-01

    Growing attention in mature T-cell lymphomas/leukemias (MTCL) is committed to more accurate and meaningful classifications, improved pathogenetic concepts and expanded therapeutic options. This requires considerations of the immunologic concepts of T-cell homeostasis and the specifics of T-cell receptor (TCR) affinities and signaling. Scientists from various disciplines established the CONTROL-T research unit and in an international conference on MTCL they brought together experts from T-cell immunity, oncology, immunotherapy and systems biology. We report here meeting highlights on the covered topics of diagnostic pitfalls, implications by the new WHO classification, insights from discovered genomic lesions as well as TCR-centric concepts of cellular dynamics in host defense, auto-immunity and tumorigenic clonal escape, including predictions to be derived from in vivo imaging and mathematical modeling. Presentations on novel treatment approaches were supplemented by strategies of optimizing T-cell immunotherapies. Work packages, that in joint efforts would advance the field of MTCL more efficiently, are identified.

  3. A cross-sectional study of the relationship between serum sexual hormone levels and internal derangement of temporomandibular joint.

    Science.gov (United States)

    Madani, A S; Shamsian, A A; Hedayati-Moghaddam, M R; Fathi-Moghadam, F; Sabooni, M R; Mirmortazavi, A; Golmohamadi, M

    2013-08-01

    Temporomandibular disorders (TMD) are defined as clinical conditions that involve the masticatory muscles, temporomandibular joint (TMJ) or both. The aim of this study was to evaluate serum 17β-oestradiol and progesterone levels in menstruating women affected by internal derangement of the TMJ. A total of 142 women (mean age 30·2 ± 6·7) who referred to medical diagnostic laboratory of Iranian Academic Centre for Education, Culture and Research (ACECR), Mashhad Branch, were enrolled during 2007 and 2008. Forty-seven individuals had disc displacement with reduction (Group IIa) according to Research Diagnostic Criteria (RDC)/TMD Axis I diagnosis. Radioimmunoassay was used for the detection of serum 17β-oestradiol and progesterone levels in all 142 subjects. The mean progesterone level was significantly higher in control group (11·6 ± 10·4 ng mL(-1) ) compared to women with TMD (8·4 ± 6·8 ng mL(-1) , P = 0·03). No significant difference was found in two groups regarding 17β-oestradiol level. Lower progesterone level in women with TMD can suggest the more important role of this hormone in the development of the disorder.

  4. Tribology of monolayer films: comparison between n-alkanethiols on gold and n-alkyl trichlorosilanes on silicon.

    Science.gov (United States)

    Booth, Brandon D; Vilt, Steven G; McCabe, Clare; Jennings, G Kane

    2009-09-01

    This Article presents a quantitative comparison of the frictional performance for monolayers derived from n-alkanethiolates on gold and n-alkyl trichlorosilanes on silicon. Monolayers were characterized by pin-on-disk tribometry, contact angle analysis, ellipsometry, and electrochemical impedance spectroscopy (EIS). Pin-on-disk microtribometry provided frictional analysis at applied normal loads from 10 to 1000 mN at a speed of 0.1 mm/s. At low loads (10 mN), methyl-terminated n-alkanethiolate self-assembled monolayers (SAMs) exhibited a 3-fold improvement in coefficient of friction over SAMs with hydroxyl- or carboxylic-acid-terminated surfaces. For monolayers prepared from both n-alkanethiols on gold and n-alkyl trichlorosilanes on silicon, a critical chain length of at least eight carbons is required for beneficial tribological performance at an applied load of 9.8 mN. Evidence for disruption of chemisorbed alkanethiolate SAMs with chain lengths n tribology wear tracks. The direct comparison between the tribological stability of alkanethiolate and silane monolayers shows that monolayers prepared from n-octadecyl dimethylchlorosilane and n-octadecyl trichlorosilane withstood normal loads at least 30 times larger than those that damaged octadecanethiolate SAMs. Collectively, our results show that the tribological properties of monolayer films are dependent on their internal stabilities, which are influenced by cohesive chain interactions (van der Waals) and the adsorbate-substrate bond.

  5. Tribological advancements for reliable wind turbine performance.

    Science.gov (United States)

    Kotzalas, Michael N; Doll, Gary L

    2010-10-28

    Wind turbines have had various limitations to their mechanical system reliability owing to tribological problems over the past few decades. While several studies show that turbines are becoming more reliable, it is still not at an overall acceptable level to the operators based on their current business models. Data show that the electrical components are the most problematic; however, the parts are small, thus easy and inexpensive to replace in the nacelle, on top of the tower. It is the tribological issues that receive the most attention as they have higher costs associated with repair or replacement. These include the blade pitch systems, nacelle yaw systems, main shaft bearings, gearboxes and generator bearings, which are the focus of this review paper. The major tribological issues in wind turbines and the technological developments to understand and solve them are discussed within. The study starts with an overview of fretting corrosion, rolling contact fatigue, and frictional torque of the blade pitch and nacelle yaw bearings, and references to some of the recent design approaches applied to solve them. Also included is a brief overview into lubricant contamination issues in the gearbox and electric current discharge or arcing damage of the generator bearings. The primary focus of this review is the detailed examination of main shaft spherical roller bearing micropitting and gearbox bearing scuffing, micropitting and the newer phenomenon of white-etch area flaking. The main shaft and gearbox are integrally related and are the most commonly referred to items involving expensive repair costs and downtime. As such, the latest research and developments related to the cause of the wear and damage modes and the technologies used or proposed to solve them are presented.

  6. High vacuum tribology of polycrystalline diamond coatings

    Indian Academy of Sciences (India)

    Awadesh K Mallik; S A Shivashankar; S K Biswas

    2009-10-01

    Polycrystalline diamond coatings have been grown on unpolished side of Si(100) wafers by hot filament chemical vapour deposition process. The morphology of the grown coatings has been varied from cauliflower morphology to faceted morphology by manipulation of the growth temperature from 700°C to 900°C and methane gas concentration from 3% to 1·5%. It is found that the coefficient of friction of the coatings under high vacuum of 133·32 × 10-7 Pa (10-7 torr) with nanocrystalline grains can be manipulated to 0·35 to enhance tribological behaviour of bare Si substrates.

  7. ADAMTS-4 and ADAMTS-5 expression in human temporomandibular joint discs with internal derangement, correlates with degeneration.

    Science.gov (United States)

    Leonardi, Rosalia; Crimi, Salvatore; Almeida, Luis Eduardo; Pannone, Giuseppe; Musumeci, Giuseppe; Castorina, Sergio; Rusu, Mugurel Constantin; Loreto, Carla

    2015-11-01

    Temporomandibular joint (TMJ) internal derangement (ID) is one of the most common form of temporomandibular disorders. There is evidence showing the increased expression of matrix metalloproteinases (MMPs) in the cells from degenerated TMJ disc. ADAMTS are a large family of metalloproteases which are responsible for proteoglycans degradation. The present study aimed to evaluate ADAMTS-4 and ADAMTS-5 immunohistochemical expression in human TMJ discs from patients affected by ID, and to find out if there is any correlation with the degree of histopathological changes. Eighteen temporomandibular displaced disc specimens and sixteen TMJ disc control were used for the present study. Specimens were immunohistochemically processed and ADAMTS-4 and ADAMTS-5 expression were obtained respectively for the anterior (AB), intermediate (IB) and posterior (PB) bands and compared to the histopathological degeneration score (HDS). Immunoreactivity for ADAMTS-4 and -5, was observed in both not degenerated and degenerated human TMJ discs. Both the percentage of ADAMTS-4 and -5 immunostained cells (ES) and the intensity of staining (IS) were significantly greater in affected specimens compared with those in control discs. The ADAMTS-5 ES and IS of the 3 bands of the disc correlated to the TMJ disc HDS (0.001 < P < 0.05), on the other hand only AB and IB, ADAMTS-4 immunostaining scores correlated to HDS. According to these findings it can be assumed in that the more histopathological changes in the disc are detected, the higher levels of ADAMTS are produced. This in turn can lead to ECM breakdown and in turn to a more advanced disc displacement. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  8. 2012 Joint Varenna-Lausanne International Workshop on the theory of fusion plasmas (Varenna, Italy, 27-31 August 2012)

    Science.gov (United States)

    Gabet, Xavier; Sauter, Olivier

    2013-07-01

    The 2012 Joint Varenna-Lausanne International Workshop on the theory of fusion plasmas was very fruitful. A broad variety of topics was addressed, covering turbulence, magnetohydrodynamics (MHD), edge physics, and radio frequency (RF) wave heating. Moreover, the scope of the meeting was extended this year to include the physics of materials and diagnostics for burning plasmas. This evolution reflects the complexity of problems at hand in fusion, some of them triggered by the construction of ITER and JT-60SA. Long-standing problems without immediate consequences have sometimes become an urgent matter in that context. One may refer to, for instance, the choice of plasma facing components or the design of control systems. Another characteristic of these workshops is the interplay between various domains of plasma physics. For instance, MHD modes are currently investigated with gyrokinetic codes, kinetic effects are included in MHD stability analysis more and more, and turbulence is now accounted for in wave propagation problems. This is proof of cross-fertilization and is certainly a healthy sign for our community. Finally, introducing some novelty in the programme does not prevent from us respecting old traditions. As usual, many presentations were dedicated to numerical simulations. Combining advanced numerical techniques with elaborated analytical theory is certainly a trademark of the Varenna-Lausanne Workshop, which was respected again this year. The quality and size of the scientific output from this workshop is shown in this special issue of Plasma Physics and Controlled Fusion; a further 26 papers have already appeared in Journal of Physics: Conference Series in December 2012. We hope the readers will enjoy this special issue, and find therein knowledge and inspiration.

  9. Biodegradation of international jet A-1 aviation fuel by microorganisms isolated from aircraft tank and joint hydrant storage systems.

    Science.gov (United States)

    Itah, A Y; Brooks, A A; Ogar, B O; Okure, A B

    2009-09-01

    Microorganisms contaminating international Jet A-1 aircraft fuel and fuel preserved in Joint Hydrant Storage Tank (JHST) were isolated, characterized and identified. The isolates were Bacillus subtillis, Bacillus megaterium, Flavobacterium oderatum, Sarcina flava, Micrococcus varians, Pseudomonas aeruginosa, Bacillus licheniformis, Bacillus cereus and Bacillus brevis. Others included Candida tropicalis, Candida albicans, Saccharomyces estuari, Saccharomyces cerevisiae, Schizosaccharomyces pombe, Aspergillus flavus, Aspergillus niger, Aspergillus fumigatus, Cladosporium resinae, Penicillium citrinum and Penicillium frequentans. The viable plate count of microorganisms in the Aircraft Tank ranged from 1.3 (+/-0.01) x 104 cfu/mL to 2.2 (+/-1.6) x 104 cfu/mL for bacteria and 102 cfu/mL to 1.68 (+/-0.32) x 103 cfu/mL for fungi. Total bacterial counts of 1.79 (+/-0.2) x 104 cfu/mL to 2.58 (+/-0.04) x 104 cfu/mL and total fungal count of 2.1 (+/-0.1) x 103 cfu/mL to 2.28 (+/-0.5) x 103 cfu/mL were obtained for JHST. Selected isolates were re-inoculated into filter sterilized aircraft fuels and biodegradation studies carried out. After 14 days incubation, Cladosporium resinae exhibited the highest degradation rate with a percentage weight loss of 66 followed by Candida albicans (60.6) while Penicillium citrinum was the least degrader with a weight loss of 41.6%. The ability of the isolates to utilize the fuel as their sole source of carbon and energy was examined and found to vary in growth profile between the isolates. The results imply that aviation fuel could be biodegraded by hydrocarbonoclastic microorganisms. To avert a possible deterioration of fuel quality during storage, fuel pipe clogging and failure, engine component damage, wing tank corrosion and aircraft disaster, efficient routine monitoring of aircraft fuel systems is advocated.

  10. Accurate Evaluation of Balancing-side Contacts in Relation to Internal Derangements of the Temporomandibular Joint : Possible Roles of Balancing-side Protection

    OpenAIRE

    Minagi, Shogo; Watanabe, Hideyuki; Tsuru, Hiromichi

    1989-01-01

    Balancing-side contacts were precisely evaluated in relation to internal derangements of the temporomandibular joint. Balancing-side contacts were classified into the three following groups: 1) Severe balancing-side interference, 2) balancing-side interference and 3) balancing-side protective contacts. Balancing-side protective contacts were defined as balancing-side occlusal contacts on lower first and/or second molar in lateral excursive movements, which are observed only when clenching for...

  11. Improvement of Internal Audit Planning Method through Application of Risk Card by the Indices of Value-Based Management System of Joint-Stock Company

    OpenAIRE

    2014-01-01

    The Article deals with issues of improving methods of planning and carrying out internal audit in conditions of risk-oriented approach to audit according to the indices of value-based management system - VBM (Value Based Management) using the risk card (risk matrix). A risk card (risk matrix) method has been disclosed taking into account risk level of each of the key factors influencing joint-stock company value rates. Recommendations have been given and abstract of working document has been ...

  12. Tribology of ceramics: Report of the Committee on Tribology of Ceramics

    Science.gov (United States)

    1988-01-01

    The current state of knowledge of ceramic surface structures, composition, and reactivity is reviewed. The tribological requirements of advanced mechanical systems now being deployed (in particular, heat engines) exceed the capabilities of traditional metallic-based materials because of the high temperatures encountered. Advanced ceramic materials for such applications are receiving intense scrutiny, but there is a lack of understanding of the properties and behavior of ceramic surfaces and the influence of processing on the properties of ceramics is described. The adequacy of models, ranging form atomic to macro, to describe and to predict ceramic friction and wear are discussed, as well as what is known about lubrication at elevated temperatures. From this analysis, recommendations are made for coordination, research, and development that will lead to better performance of ceramic materials in tribological systems.

  13. Jointly Building a More Secure Asia through the Power of People——Some Highlight of Commemoration of the International Day of Peace 2014

    Institute of Scientific and Technical Information of China (English)

    Lin; Yongfeng

    2014-01-01

    <正>To observe the International Day of Peace 2014,in accordance with its theme set by the United Nations,i.e.,"Right of Peoples to Peace",the CPAPD together with the UN System in China and the Shanxi Provincial People’s Government jointly held the Commemoration of the International Day of Peace2014,with the theme of"A more secure Asia aspired by people"in Xi’an City,west China during 23-24September 2014.Chinese CPC and state leaders,

  14. [Case-control study on measurement of coracoclavicular and acromioclavicular ligament injuries during internal fixation operation for the treatment of fresh acromioclavicular joint dislocation of Tossy type III].

    Science.gov (United States)

    Guan, Ting-Jin; Sun, Peng; Zheng, Liang-Guo; Qi, Xiang-Yang

    2014-01-01

    To study measurement methods of acromioclavicular and coracoclavicular ligament injuries,its therapeutic effects and complications during internal fixation operation for the treatment of fresh acromioclavicular joint dislocations of Tossy type III. From July 2003 to May 2012,127 patients with acromioclavicular joint dislocations of Tossy type III were treated with wire fixation from coracoid process to clavicle or hook-plate fixation. The patients were divided into group A (63 cases) and group B (64 cases) according to whether acromioclavicular ligament and coracoclavicular ligament were repaired or not. In group A (ligaments repaired), there were 39 males and 24 females with an average age of (33.25 +/- 8.46) years old (ranged from 17 to 59 years). And in group B (no ligaments repaired), there were 41 males and 23 females with an average age of (34.10 +/- 7.19) years (ranged from 19 to 57 years). The operation times, intraoperative blood loss, postoperative infections, internal fixation failure, recurrence and other complications, together with therapeutic effects were compared between two groups. The outcome was analyzed according to Karlsson standard. In group A, 54 patients got an excellent result and 9 good according to Karlsson standard;the average operative time was (55.90 +/- 26.56) min; the average intraoperative bleeding amount was (99.80 +/- 50.30) ml; 1 patient had wire broken without re-dislocation at 16 weeks after operation, 3 patients got wound fat liquefaction and recovered after treatment, 1 patient had pain after shoulder joint motion and pain disappeared after implants were taken out. In group B, 52 patients got an excellent result and 12 good according to Karlsson standard; the average operative time was (49.50 +/- 23.14) min; the average intraoperative bleeding amount was (87.30 +/- 46.41) ml; 2 patients got wound fat liquefaction, and 2 patients had pain after shoulder joint motion. All the patients were followed up, and the duration ranged

  15. Tribological design constraints of marine renewable energy systems.

    Science.gov (United States)

    Wood, Robert J K; Bahaj, AbuBakr S; Turnock, Stephen R; Wang, Ling; Evans, Martin

    2010-10-28

    Against the backdrop of increasing energy demands, the threat of climate change and dwindling fuel reserves, finding reliable, diverse, sustainable/renewable, affordable energy resources has become a priority for many countries. Marine energy conversion systems are at the forefront of providing such a resource. Most marine renewable energy conversion systems require tribological components to convert wind or tidal streams to rotational motion for generating electricity while wave machines typically use oscillating hinge or piston within cylinder geometries to promote reciprocating linear motion. This paper looks at the tribology of three green marine energy systems, offshore wind, tidal and wave machines. Areas covered include lubrication and contamination, bearing and gearbox issues, biofouling, cavitation erosion, tribocorrosion, condition monitoring as well as design trends and loading conditions associated with tribological components. Current research thrusts are highlighted along with areas needing research as well as addressing present-day issues related to the tribology of offshore energy conversion technologies.

  16. Review of tribological sinks in six major industries

    Energy Technology Data Exchange (ETDEWEB)

    Imhoff, C.H.; Brown, D.R.; Hane, G.J.; Hutchinson, R.A.; Erickson, R.; Merriman, T.; Gruber, T.; Barber, S.

    1985-09-01

    Friction and material wear occur throughout all industries and are involved in many processes within each industry. These conditions make assessing tribological activity overall in industry very complex and expensive. Therefore, a research strategy to obtain preliminary information on only the most significant industrial tribological sinks was defined. The industries examined were selected according to both the magnitude of overall energy consumption (particularly machine drive) and the known presence of significant tribological sinks. The six industries chosen are as follows: mining, agriculture, primary metals, chemicals/refining, food, and pulp and paper. They were reviewed to identify and characterize the major tribology sinks. It was concluded that wear losses are greater than friction losses, and that reducing wear rates would improve industrial productivity.

  17. Comparison of tribological properties for graphite coatings used for remanufacturing

    Institute of Scientific and Technical Information of China (English)

    ZHU Yu-ling

    2005-01-01

    To improve the solid lubricity on the worn surface of frictional-pairs, a convenient and simple brushpainting technique was utilized to prepare the solid lubrication graphite coatings. The bonding between the coatings and substrate is good. To examine the influence of the different graphite contents on the tribological properties of the graphite coatings, the comparison experiments were carried out on the ring-on-block friction tester. The tribological results show a change law of saddle-shape between the tribological properties of graphite coatings and graphite content. When the amount of graphite is up to 28 g, the tribological properties of graphite coating are the best.The excellent anti-friction of the graphite coating is associated with the close-packed hexagonal crystal structure of graphite.

  18. Tribological properties and lubricating mechanisms of Cu nanoparticles in lubricant

    Institute of Scientific and Technical Information of China (English)

    YU He-long; XU Yi; SHI Pei-jing; XU Bin-shi; WANG Xiao-li; LIU Qian

    2008-01-01

    Wear and friction properties of surface modified Cu nanoparticles as 50CC oil additive were studied.The effect of temperature on tribological properties of Cu nanoparticles was investigated on a four-ball tester.The morphologies,typical element distribution and chemical states of the worn surfaces were characterized by SEM,EDS and XPS,respectively.In order to further investigate the tribological mechanism of Cu nanoparticles,a nano-indentation tester was utilized to measure the micro mechanical Properties of the worn surface.The results indicate that the higher me oil temperature applied,the better the tribological properties of Cu nanoparticles are.It can be inferred that a thin copper protective film with lower elastic modulus and hardness is formed on the wom surface,which results in the good tribological performances of Cu nanoparticles,especially when the Oil temperature is higher.

  19. Tribological investigations of sol-gel ceramic films

    Institute of Scientific and Technical Information of China (English)

    张文光; 王成焘; 刘维民

    2002-01-01

    Tribological properties of the TiO2, doped TiO2, AI2O3 and SiO2 thin films prepared by different sol-gel processes are reported. The results indicate that doping deteriorates the wear resistance of TiO2; organic modifier can improve the tribological property of AI2O3 significantly; and the SiO2 film prepared from inorganic salt sodium silicate registers much better wear resistance than that from ethyl orthosilicate.

  20. Tribological investigations of sol-gel ceramic films

    Institute of Scientific and Technical Information of China (English)

    张文光; 刘维民; 王成焘

    2002-01-01

    Tribological properties of the TiO2, doped TiO2, Al2O3 and SiO2 thin films prepared by different sol-gel processes are reported. The results indicate that doping deteriorates the wear resistance of TiO2; organic modifier can improve the tribological property of Al2O3 significantly; and the SiO2 film prepared from inorganic salt sodium silicate registers much better wear resistance than that from ethyl orthosilicate.

  1. INVESTIGATION OF TRIBOLOGICAL PROPERTIES CuSn10 BEARING MATERIAL

    OpenAIRE

    2005-01-01

    Bronzes which copper based alloys is widely used because of properties physical, thermal and tribological as journal bearing material. This material that has tribological performance good conclusions gives at journal bearings. In this study, CuSn10 bronze that were manufactured journal bearings friction and wear properties has been examined and compared. SAE 1050 steel shaft has been used as counter abrader. Experiments have been carried out 10 N and 20 N loads, 750 and 1500 rpm, dry and lubr...

  2. Tribology of selected ceramics at temperatures to 900 C

    Science.gov (United States)

    Sliney, H. E.; Jacobson, T. P.; Deadmore, D.; Miyoshi, K.

    1986-01-01

    Results of fundamental and focused research on the tribological properties of ceramics are discussed. The basic friction and wear characteristics are given for ceramics of interest for use in gas turbine, adiabatic diesel, and Stirling engine applications. The importance of metal oxides in ceramic/metal sliding combinations is illustrated. The formulation and tribological additives are described. Friction and wear data are given for carbide and oxide-based composite coatings for temperatures to at least 900 C.

  3. Coupling problem between the dynamical and tribological behaviors in the piston-liner systems of multi-cylinder IC engines

    Institute of Scientific and Technical Information of China (English)

    WANG Yi-liang; XIE You-bai

    2007-01-01

    This paper deals with the coupling problem between the dynamic behaviors and the tribological behaviors of the piston-liner systems in multi-cylinder internal combustion engines. Firstly, based on the correction of some errors in the equation of piston secondary motion, which have been employed by many authors for several years, a detailed mathematical model for the coupling problem between the dynamical and tribological behaviors in the piston-liner systems of multi-cylinder internal combustion engines is presented. Secondly, the lubrication and friction between the liner and piston in each cylinder is included applying the average flow model of the Reynolds equation. Thirdly, the vibration of each liner is computed through the finite element model of a four-cylinder engine block, by which not only the liner motions caused by the block vibration but also the local vibration and the local static deformation of each liner can be figured out and taken into account. Through theoretical analysis and computation, some conclusions can be drawn as: 1 ) Both the liner vibration and piston motion are different for different cylinder in a multi-cylinder internal combustion engine, and hence different piston-liner systems will have different tribological behaviors. 2) Different liners have coincident dynamic response on the whole, especially for the lower frequency components. However, differences still exist among the vibrations of different liners, and these differences are mainly owing to the higher frequency components. 3 ) The impacts of liner vibrations on the tribological behaviors in piston-liner systems are primarily ascribed to its higher frequency components.

  4. Driven dynamics of simplified tribological models

    Science.gov (United States)

    Vanossi, A.; Braun, O. M.

    2007-08-01

    Over the last decade, remarkable developments in nanotechnology, notably the use of atomic and friction force microscopes (AFM/FFM), the surface-force apparatus (SFA) and the quartz-crystal microbalance (QCM), have provided the possibility to build experimental devices able to perform analysis on well-characterized materials at the nano- and microscale. Simultaneously, tremendous advances in computing hardware and methodology (molecular dynamics techniques and ab initio calculations) have dramatically increased the ability of theoreticians to simulate tribological processes, supplying very detailed information on the atomic scale for realistic sliding systems. This acceleration in experiments and computations, leading often to very detailed yet complex data, has deeply stimulated the search, rediscovery and implementation of simpler mathematical models such as the generalized Frenkel-Kontorova and Tomlinson models, capable of describing and interpreting, in a more immediate way, the essential physics involved in nonlinear sliding phenomena.

  5. Fundamentals of tribology at the atomic level

    Science.gov (United States)

    Ferrante, John; Pepper, Stephen V.

    1989-01-01

    Tribology, the science and engineering of solid surfaces in moving contact, is a field that encompasses many disciplines: solid state physics, chemistry, materials science, and mechanical engineering. In spite of the practical importance and maturity of the field, the fundamental understanding of basic phenomena has only recently been attacked. An attempt to define some of these problems and indicate some profitable directions for future research is presented. There are three broad classifications: (1) fluid properties (compression, rheology, additives and particulates); (2) material properties of the solids (deformation, defect formation and energy loss mechanisms); and (3) interfacial properties (adhesion, friction chemical reactions, and boundary films). Research in the categories has traditionally been approached by considering macroscopic material properties. Recent activity has shown that some issues can be approached at the atomic level: the atoms in the materials can be manipulated both experimentally and theoretically, and can produce results related to macroscopic phenomena.

  6. Development of Ti-C-N coatings with improved tribological behavior and antibacterial properties.

    Science.gov (United States)

    Sáenz de Viteri, Virginia; Barandika, Gotzone; Bayón, Raquel; Fernández, Xana; Ciarsolo, Iñigo; Igartua, Amaya; Pérez Tanoira, Ramón; Moreno, Jaime Esteban; Peremarch, Conchita Pérez-Jorge

    2015-03-01

    In artificial metallic joint implants, the failure is provoked by two effects in most of the cases: mass loss and wear debris removed due to tribological-corrosive effects on the implant alloy, and infections due to the presence of bacteria. In this work, several Ti-C-N corrosion and wear protective coatings were developed by Physical Vapour Deposition technology, and deposited on Ti6Al4V alloy. In order to provide the implant antibacterial properties, an additional silver top coating has been deposited. Tribological behavior was characterized through tribocorrosion and fretting tests. On the other hand, wettability tests were performed to study the grade of hydrophilicity/hydrophobia. Additionally, antibacterial properties were evaluated by means of bacterial adhesion tests. As a result of these characterization studies, the coating with the best performance was selected. The as-coated material includes excellent protection against tribocorrosion and fretting effects (in relation to the uncoated one) and the silver layer has been confirmed to exhibit antibacterial properties.

  7. In-situ electrochemical study of interaction of tribology and corrosion in artificial hip prosthesis simulators.

    Science.gov (United States)

    Yan, Yu; Dowson, Duncan; Neville, Anne

    2013-02-01

    The second generation Metal-on-Metal (MoM) hip replacements have been considered as an alternative to commonly used Polyethylene-on-Metal (PoM) joint prostheses due to polyethylene wear debris induced osteolysis. However, the role of corrosion and the biofilm formed under tribological contact are still not fully understood. Enhanced metal ion concentrations have been reported widely from hair, blood and urine samples of patients who received metal hip replacements and in isolated cases when abnormally high levels have caused adverse local tissue reactions. An understanding of the origin of metal ions is really important in order to design alloys for reduced ion release. Reciprocating pin-on-plate wear tester is a standard instrument to assess the interaction of corrosion and wear. However, more realistic hip simulator can provide a better understanding of tribocorrosion process for hip implants. It is very important to instrument the conventional hip simulator to enable electrochemical measurements. In this study, simple reciprocating pin-on-plate wear tests and hip simulator tests were compared. It was found that metal ions originated from two sources: (a) a depassivation of the contacting surfaces due to tribology (rubbing) and (b) corrosion of nano-sized wear particles generated from the contacting surfaces.

  8. Nanomechanical and tribological characterization of the MPC phospholipid polymer photografted onto rough polyethylene implants.

    Science.gov (United States)

    Wang, Na; Trunfio-Sfarghiu, Ana-Maria; Portinha, Daniel; Descartes, Sylvie; Fleury, Etienne; Berthier, Yves; Rieu, Jean-Paul

    2013-08-01

    Grafting biomimetic polymers onto biomaterials such as implants is one of the promising approaches to increase their tribological performance and biocompatibility and to reduce wear. In this paper, poly(2-methacryloyloxyethyl phosphorylcholine) (p(MPC)) brushes were obtained by photografting MPC from the rough surface of ultra high molecular weight polyethylene (UHMWPE) joint implants. Such substrates have a high roughness (Ra∼650nm) which often has the same order of magnitude as the brush thickness, so it is very difficult to estimate the vertical density profile of the grafted content. The quality of the p(MPC) grafting was evaluated through a wide range of characterization techniques to reveal the effectiveness of the grafting: atomic force microcopy (AFM) imaging and force spectroscopy, contact angle, SEM/EDX, and confocal microscopy. After testing the methods on smooth glass substrate as reference, AFM nano-indentation proves to be a reliable non destructive method to characterize the thickness and the mechanical properties of the p(MPC) layer in liquid physiological medium. Tribological measurements using a homemade biotribometer confirm that, despite heterogeneity thickness (h=0.5-6μm), the p(MPC) layer covers the roughness of the UHMWPE substrate and acts as an efficient lubricant with low friction coefficient and no wear for 9h of friction.

  9. Tribology: Properties of materials. (Latest citations from the EI Compendex*plus database). Published Search

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-03-01

    The bibliography contains citations concerning tribological properties of composite materials, plastics, metals, and ceramics. Test apparatus and design techniques for evaluating the effects of temperature, load, sliding speed, surface contact, lubricants, and additives on tribological behavior of materials are discussed. Tribological assessment of materials and wear processes on tribologically loaded material surfaces are considered. (Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

  10. Biofluid lubrication for artificial joints

    Science.gov (United States)

    Pendleton, Alice Mae

    This research investigated biofluid lubrication related to artificial joints using tribological and rheological approaches. Biofluids studied here represent two categories of fluids, base fluids and nanostructured biofluids. Base fluids were studied through comparison of synthetic fluids (simulated body fluid and hyaluronic acid) as well as natural biofluids (from dogs, horses, and humans) in terms of viscosity and fluid shear stress. The nano-structured biofluids were formed using molecules having well-defined shapes. Understanding nano-structured biofluids leads to new ways of design and synthesis of biofluids that are beneficial for artificial joint performance. Experimental approaches were utilized in the present research. This includes basic analysis of biofluids' property, such as viscosity, fluid shear stress, and shear rate using rheological experiments. Tribological investigation and surface characterization were conducted in order to understand effects of molecular and nanostructures on fluid lubrication. Workpiece surface structure and wear mechanisms were investigated using a scanning electron microscope and a transmission electron microscope. The surface topography was examined using a profilometer. The results demonstrated that with the adding of solid additives, such as crown ether or fullerene acted as rough as the other solids in the 3-body wear systems. In addition, the fullerene supplied low friction and low wear, which designates the lubrication purpose of this particular particle system. This dissertation is constructed of six chapters. The first chapter is an introduction to body fluids, as mentioned earlier. After Chapter II, it examines the motivation and approach of the present research, Chapter III discusses the experimental approaches, including materials, experimental setup, and conditions. In Chapter IV, lubrication properties of various fluids are discussed. The tribological properties and performance nanostructured biofluids are

  11. Assessment of industrial attitudes toward generic research needs in tribology

    Energy Technology Data Exchange (ETDEWEB)

    Sibley, L.B.; Zlotnick, M.; Levinson, T.M.

    1985-09-01

    Based on extended discussions during visits with 27 companies representing 13 different parts of the tribology industry (such as bearings, lubricants, coatings, powerplants), it is apparent that only a tiny fraction of the large sums publicly reported as R and D expenditures by industry are used to fund generic tribology research. For example, of the greater than $2 B expenditures reported for R and D in the lubricants sector for 1982, the estimated total for generic tribology research was $12 M. This was the largest expenditure in any sector of the tribology industry and one-third of the total of $36 M. In the automotive industry out of a reported expenditure of $4 B, the estimated generic tribology research was $3 M. In some segments of the tribology industry, for example coatings and filters, there were no expenditures on generic research. There was little tendency to improve the state of the art of the tribology industry through long-term investment in generic R and D in ways that would foster innovation and productivity of energy conservation technology. Expenditures were oriented to development of specific commercial and military products, or to basic research focused on unspecified far term results, although useful spin-off of military developments into commercial fields sometimes occurs. There was a broad consensus in the companies visited that existing research results were not always made easily accessible to potential users in industry. The implication was that industry might benefit more if a larger fraction of the funds were devoted to putting the research results into a form design and development engineers could more readily apply. The need for a more effective presentation of research results was expressed with greater urgency at the smaller companies, but there seemed to be a broad consensus on the need for improvement. Recommendations are given.

  12. Rapid Discovery of Tribological Materials with Improved Performance Using Materials Informatics

    Science.gov (United States)

    2014-03-10

    Discovery of Tribological Materials with Improved Performance Using Materials Informatics Technical Contact: Susan B. Sinnott University of Florida...relative scarcity of work examining these materials for tribological performance, there is a correspondingly urgent need for the rapid determination...partitioning. Error bars represent the ’standard deviation relative to each branch of the dendrogram (27). III C Tribological Database · In order to

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

    Institute of Scientific and Technical Information of China (English)

    DAI; Zhendong; Stanislav; N.; Gorb

    2004-01-01

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

  14. STRATEGIES FOR COPING WITH PAIN AND PSYCHOLOGICAL DISTRESS ASSOCIATED WITH TEMPOROMANDIBULAR-JOINT OSTEOARTHROSIS AND INTERNAL DERANGEMENT

    NARCIS (Netherlands)

    JASPERS, JPC; HEUVEL, F; STEGENGA, B; DEBONT, LGM

    1993-01-01

    Objective: To analyse the relationship among a variety of emotional, cognitive, and behavioral coping strategies and pain/suffering and psychological distress in patients with temporomandibular joint (TMJ) pain. Design: Cross-sectional, correlational study. Setting: Department of Oral and Maxillofac

  15. The origin of islands in the Kandalaksha Gulf of the White Sea: joint work of internal and external geodynamic processes

    Science.gov (United States)

    Kosevich, Natalia; Romanovskaya, Maria

    2016-04-01

    The modern White Sea basin is a part of the encounter zone between the East European Platform and of the Fennoscandian Shield. The Kandalaksha Gulf in its northwest lies on the Mesoarchean-Paleoproterozoic structure known as the White Sea Shift Belt. In the Oligocene, it entered its neotectonic stage. Geologically, there are two structural storeys beneath the seafloor of the Kandalaksha Gulf: 1) crystalline bedrock of the Archean White Sea complex; 2) a cover of sediment consisting of three layers: Riphean sandstones, terrigenous Vendian deposits; a cloak of Pleistocene and Holocene deposits and sediments - glacial drifts, transitional glaciomarine sediments and purely marine sediments. The modern White Sea is a young basin formed just 10 to 12 ka. The geological and geomorphic history of the White Sea region was very complicated, with various and often conflicting tectonic movements. Besides the postglacial isostatic rise of Scandinavia amounted to some 100 meters in the White Sea area. The White Sea has numerous islands that are very different in the geological-geomorphological and genetic senses because their origin is the result of interactions between various endogenous and exogenous processes. Large and detailed scale geological and morphological researches of the islands at the southern and northern coast of the Kandalaksha Gulf have been carried out. Landforms of the islands were produced by the joint effects of such processes as (1) glacial-tectonic effects and marine wave action, (2) tidal and surge effects; (3) glacial-tectonic, marine, and gravity effects, and (4) glacial-tectonic, marine, lake, and biogenic effects (Kosevich, 2015). The relief structure of the islands has the following regularities: 1) structures of the northern coast islands are more often landforms that are composed of loose deposits with small sites of structural denudation residual outcrops; 2) the structures of the southern coast islands are typically combinations of loose

  16. Nano-enabled tribological thin film coatings: global patent scenario.

    Science.gov (United States)

    Sivudu, Kurva S; Mahajan, Yashwant R; Joshi, Shrikant V

    2014-01-01

    The aim of this paper is to present current status and future prospects of nano-enabled tribological thin film coatings based on worldwide patent landscape analysis. The study also presents an overview of technological trends by carrying out state-of-the-art literature analysis, including survey of corporate websites. Nanostructured tribological coatings encompass a wide spectrum of nanoscale microstructures, including nanocrystalline, nanolayered, nano-multilayered, nanocomposite, nanogradient structures or their unique combinations, which are composed of single or multi-component phases. The distinct microstructural features of the coatings impart outstanding tribological properties combined with multifunctional attributes to the coated components. Their unique combination of remarkable properties make them ideal candidates for a wide range of applications in diverse fields such as cutting and metalworking tools, biomedical devices, automotive engine components, wear parts, hard disc drives etc. The patent landscape analysis has revealed that nano-enabled tribological thin film coatings have significant potential for commercial applications in view of the lion's share of corporate industry in patenting activity. The largest patent portfolio is held by Japan followed by USA, Germany, Sweden and China. The prominent players involved in this field are Mitsubishi Materials Corp., Sandvik Aktiebolag, Hitachi Ltd., Sumitomo Electric Industries Ltd., OC Oerlikon Corp., and so on. The outstanding potential of nanostructured thin film tribological coatings is yet to be fully unravelled and, therefore, immense opportunities are available in future for microstructurally engineered novel coatings to enhance their performance and functionality by many folds.

  17. Tribology of swollen starch granule suspensions from maize and potato.

    Science.gov (United States)

    Zhang, Bin; Selway, Nichola; Shelat, Kinnari J; Dhital, Sushil; Stokes, Jason R; Gidley, Michael J

    2017-01-02

    The tribological properties of suspensions of cooked swollen starch granules are characterised for systems based on maize starch and potato starch. These systems are known as granule 'ghosts' due to the release (and removal) of polymer from their structure during cooking. Maize starch ghosts are less swollen than potato starch ghosts, resulting in a higher packing concentration and greater mechanical stability. In a soft-tribological contact, maize ghost suspensions reduce friction compared to the solvent (water), generate bell-shaped tribological profiles characteristic of particle entrainment and show a marked concentration dependence, whereas potato ghost suspensions exhibit lubrication behaviour similar to water. Microscopy analysis of the samples following tribological testing suggests that this is due to the rapid break-up of potato ghosts under the shear and rolling conditions within the tribological contact. A reduction in the small deformation moduli (associated with a weak gel structure) is also observed when the potato ghost suspensions are subjected to steady shear using parallel plate rheometry; both microscopy and particle size analysis show that this is accompanied by the partial shear-induced breakage of ghost particles. This interplay between particle microstructure and the resultant rheological and lubrication dynamics of starch ghost suspensions contributes to an enhanced mechanistic understanding of textural and other functional properties of cooked starches in food and other applications.

  18. Erratum to: An International Urogynecological Association (IUGA) / International Continence Society (ICS) joint report on the terminology for female pelvic organ prolapse (POP)

    NARCIS (Netherlands)

    Haylen, Bernard T.; Maher, Christopher F.; Barber, Matthew D.; Camargo, Sérgio; Dandolu, Vani; Digesu, Alex; Goldman, Howard B.; Huser, Martin; Milani, Alfredo L.; Moran, Paul A.; Schaer, Gabriel N.; Withagen, Mariëlla I J

    2016-01-01

    Introduction: The terminology for female pelvic floor prolapse (POP) should be defined and organized in a clinically-based consensus Report. Methods: This Report combines the input of members of two International Organizations, the International Urogynecological Association (IUGA) and the Internatio

  19. Exploring the relationships between International Classification of Functioning, Disability and Health (ICF constructs of Impairment, Activity Limitation and Participation Restriction in people with osteoarthritis prior to joint replacement

    Directory of Open Access Journals (Sweden)

    Johnston Marie

    2011-05-01

    Full Text Available Abstract Background The International Classification of Functioning, Disability and Health (ICF proposes three main constructs, impairment (I, activity limitation (A and participation restriction (P. The ICF model allows for all paths between the constructs to be explored, with significant paths likely to vary for different conditions. The relationships between I, A and P have been explored in some conditions but not previously in people with osteoarthritis prior to joint replacement. The aim of this paper is to examine these relationships using separate measures of each construct and structural equation modelling. Methods A geographical cohort of 413 patients with osteoarthritis about to undergo hip and knee joint replacement completed the Aberdeen measures of Impairment, Activity Limitation and Participation Restriction (Ab-IAP. Confirmatory factor analysis was used to test the three factor (I, A, P measurement model. Structural equation modelling was used to explore the I, A and P pathways in the ICF model. Results There was support from confirmatory factor analysis for the three factor I, A, P measurement model. The structural equation model had good fit [S-B Chi-square = 439.45, df = 149, CFI robust = 0.91, RMSEA robust = 0.07] and indicated significant pathways between I and A (standardised coefficient = 0.76 p Conclusion The significant pathways suggest that treatments and interventions aimed at reducing impairment, such as joint replacement, may only affect P indirectly, through A, however, longitudinal data would be needed to establish this.

  20. Effect of temperature on tribological properties of palm biodiesel

    Energy Technology Data Exchange (ETDEWEB)

    Haseeb, A.S.M.A.; Sia, S.Y.; Fazal, M.A.; Masjuki, H.H. [Department of Mechanical Engineering, University of Malaya, 50603 Kuala Lumpur (Malaysia)

    2010-03-15

    Biodiesel, as an alternative fuel is steadily gaining attention to replace petroleum diesel partially or completely. The tribological performance of biodiesel is crucial for its application in automobiles. In the present study, effect of temperature on the tribological performance of palm biodiesel was investigated by using four ball wear machine. Tests were conducted at temperatures 30, 45, 60 and 75 C, under a normal load of 40 kg for 1 h at speed 1200 rpm. For each temperature, the tribological properties of petroleum diesel (B0) and three biodiesel blends like B10, B20, B50 were investigated and compared. During the wear test, frictional torque was recorded on line. Wear scars in tested ball were investigated by optical microscopy. Results show that friction and wear increase with increasing temperature. (author)

  1. Tribological and corrosion behaviors of carburized AISI 4340 steel

    Science.gov (United States)

    Thong-on, Atcharawadi; Boonruang, Chatdanai

    2016-01-01

    AISI 4340 steel is widely used in automotive and aircraft industries as gear components. In such applications, surface hardening processes such as carburizing are required in order to improve the life time of the components. There are many studies showing the tribological behavior of the carburized steel, but the corrosion behavior has not yet been clarified. This paper reports on both tribological and corrosion behaviors of the carburized AISI 4340 steel. Factor associated with carburizing, such as the quantities of deposited carbon, dissolved carbon, and formed Cr23C6 and Fe3C, affect the tribological and corrosion behaviors of the steel by improving hardness, friction, lubrication, and wear resistance; but corrosion resistance is reduced. The dissolved carbon affects the formation of the oxide layer of the carburized steel, by obstructing the continuous oxide layer formation and by decreasing the chromium content of the steel, leading to the decrease in the corrosion resistance of the steel.

  2. Injection molding of bushes made of tribological PEEK composites

    Directory of Open Access Journals (Sweden)

    2007-12-01

    Full Text Available Polyetheretherketone (PEEK composites have been extensively studied because of the excellent tribological behavior among plastics. However, laboratory specimens and tests are generally discussed, whereas application studies on industrial components are infrequent. In this paper, an injection molded bush made of tribological PEEK was analyzed to correlate wear behavior and molded material structure. Bushes were tested under unlubricated sliding conditions by means of a short wear test. Surface analysis, differential scanning calorimetry (DSC and optical microscopy were used to evaluate the distribution of the different composite fillers (polytetrafluoroethylene, PTFE, graphite particles and carbon microfibers and their effect on the final bush behavior. A significant lack of homogeneity was observed in the molded bush and black bands appeared on the shaft surface after testing due to the sliding. The bush geometry and the injection molding process should be optimized to allow the best tribological behavior of the molded material under working conditions.

  3. Tribological Performance and Tribochemical Mechanism of Lanthanum Dialkyldithiophosphate

    Institute of Scientific and Technical Information of China (English)

    Jiang Song; Wei Yunlong; Cheng Xiyun; Chen Boshui

    2005-01-01

    Lanthanum dialkyldithiophosphate (LaDDP) was synthesized. Its tribological behavior was evaluated with a four-ball machine. The results show that LaDDP possesses very good antiwear and friction reduction capacities. The boundary film composition, characterized by X-ray photoelectron spectroscopy (XPS) and Auger electron spectroscopy (AES), reveals that the antiwear and friction reduction layer containing metallic La, La2O3, phosphate, sulphate, tribopolmer and lanthanum tribodiffusion layer prevent the rubbing pairs from contacting directly and result in better extreme pressure and antiwear behavior. The microhardness of frictional surface increases by 25%. It indicates that the frictional surface is strengthened by La tribodiffusion layer. The tribological decomposition reactions of LaDDP are simulated through mass spectroscopy. Its tribological mechanism was suggested.

  4. Applications of surface analysis and surface theory in tribology

    Science.gov (United States)

    Ferrante, John

    1989-01-01

    Tribology, the study of adhesion, friction and wear of materials, is a complex field which requires a knowledge of solid state physics, surface physics, chemistry, material science, and mechanical engineering. It has been dominated, however, by the more practical need to make equipment work. With the advent of surface analysis and advances in surface and solid-state theory, a new dimension has been added to the analysis of interactions at tribological interfaces. In this paper the applications of tribological studies and their limitations are presented. Examples from research at the NASA Lewis Research Center are given. Emphasis is on fundamental studies involving the effects of monolayer coverage and thick films on friction and wear. A summary of the current status of theoretical calculations of defect energetics is presented. In addition, some new theoretical techniques which enable simplified quantitative calculations of adhesion, fracture, and friction are discussed.

  5. Tribological Studies of Dynamic Thermal Seal Materials

    Science.gov (United States)

    DeMange, Jeffrey J.; Taylor, Shawn C.

    2016-01-01

    Thermal seals are required on high-speed vehicles in many dynamic applications such as variable inlets in propulsion systems and control surfaces. These seals, often referred to as dynamic thermal seals, must not only mitigate inboard heat transfer, but must also exhibit sufficient durability when scrubbed against mating surfaces. For high-temperature high-speed vehicle applications, the mating surfaces are often made from thermal protection system (TPS) materials, which are typically rougher and more abrasive than TPS materials used at lower temperatures. The high-temperature TPS materials used can include non-ablative (e.g., lightweight porous oxides, ceramic matrix composites) andor ablative systems (e.g., phenolic systems). Due to the increased need for durable high-temperature dynamic seals, researchers working with the NASA Glenn Research Center embarked on an effort to (a) characterize the tribological performance of state-of-the-art thermal seal materials against a variety of TPS materials and (b) develop approaches for improved wear resistance. Tests were conducted using a recently upgraded high-temperature tribometer to assess wear resistance for a variety of tribopairs under multiple conditions. This data will begin to frame the challenges of using these materials and eventually permit an improved ability to design and implement these critical TPS components.

  6. Tribological performance of DLC coatings on UHMWPE

    Energy Technology Data Exchange (ETDEWEB)

    Martinez-Nogues, V; Medel, F J; Mariscal, M D; Endrino, J L; Krzanowski, J; Yubero, F; Puertolas, J A, E-mail: enav@unizar.es

    2010-11-01

    Diamond like carbon (DLC) coatings were deposited by several methods (ion beam assisted evaporation, magnetron sputtering, filter cathodic arc, and plasma enhanced chemical vapor deposition) onto medical grade ultra-high-molecular weight polyethylene (UHMWPE) discs. The chemical characteristics and mechanical properties of the deposited DLC coatings were studied by Raman spectroscopy and nanoindentation, respectively. In addition, a set of tribological tests was conducted at human body temperature and under bovine serum lubrication against alumina balls. After testing, wear tracks were both visually inspected and documented using confocal microscopy. Visual inspection of the wear tracks confirmed that the DLC coatings were completely removed in all cases, the only exception being the DLC coating prepared by magnetron sputtering with thickness about 0.5 microns. Although this type of DLC coating exhibited the highest friction coefficient, and therefore it suggested a somewhat lower resistance to abrasive/adhesive wear conditions, no evidence of cracking or delamination was observed after the high contact pressure wear testing. This fact points out a good substrate-coating adhesion, and confirms magnetron sputtered DLC as a potential coating for orthopaedic applications.

  7. Internal derangement in the temporomandibular joint of juveniles with clinical signs of TMD : MRI-assessed association with skeletal and dental classes.

    Science.gov (United States)

    Stein, Steffen; Hellak, Andreas; Popović, Nenad; Toll, Douglas; Schauseil, Michael; Braun, Andreas

    2017-01-01

    The aim of this study was to investigate possible correlation of specific skeletal or dental class in children and adolescents with clinical signs of temporomandibular dysfunction (TMD) with the severity of internal derangement (ID) of the temporomandibular joint. Based on MRI images, the ID of 232 juvenile temporomandibular joints in 116 patients were retrospectively recorded. The distribution of the ID stages within the skeletal and dental classes was compared by means of the χ (2) test. Excluding the comparison between skeletal Class I (S I) and skeletal Class II (S II; p  0.05). No statistically significant differences were found when comparing the distribution of the ID stages between the dental classes (p > 0.05). According to these findings, there is no skeletal or dental class that is related to higher degrees of internal derangement in the TMJs of children and adolescents presenting clinical signs of TMD. Therefore, it is not possible to draw conclusions about the severity of the ID in relation to the dental and skeletal class in symptomatic juvenile TMJs.

  8. Arthroscopically Assisted Reconstruction of Acute Acromioclavicular Joint Dislocations: Anatomic AC Ligament Reconstruction With Protective Internal Bracing—The “AC-RecoBridge” Technique

    Science.gov (United States)

    Izadpanah, Kaywan; Jaeger, Martin; Ogon, Peter; Südkamp, Norbert P.; Maier, Dirk

    2015-01-01

    An arthroscopically assisted technique for the treatment of acute acromioclavicular joint dislocations is presented. This pathology-based procedure aims to achieve anatomic healing of both the acromioclavicular ligament complex (ACLC) and the coracoclavicular ligaments. First, the acromioclavicular joint is reduced anatomically under macroscopic and radiologic control and temporarily transfixed with a K-wire. A single-channel technique using 2 suture tapes provides secure coracoclavicular stabilization. The key step of the procedure consists of the anatomic repair of the ACLC (“AC-Reco”). Basically, we have observed 4 patterns of injury: clavicular-sided, acromial-sided, oblique, and midportion tears. Direct and/or transosseous ACLC repair is performed accordingly. Then, an X-configured acromioclavicular suture tape cerclage (“AC-Bridge”) is applied under arthroscopic assistance to limit horizontal clavicular translation to a physiological extent. The AC-Bridge follows the principle of internal bracing and protects healing of the ACLC repair. The AC-Bridge is tightened on top of the repair, creating an additional suture-bridge effect and promoting anatomic ACLC healing. We refer to this combined technique of anatomic ACLC repair and protective internal bracing as the “AC-RecoBridge.” A detailed stepwise description of the surgical technique, including indications, technical pearls and pitfalls, and potential complications, is given. PMID:26052493

  9. Industrial tribology tribosystems, friction, wear and surface engineering, lubrication

    CERN Document Server

    Mang, Theo; Bartels, Thorsten

    2010-01-01

    Integrating very interesting results from the most important R & D project ever made in Germany, this book offers a basic understanding of tribological systems and the latest developments in reduction of wear and energy consumption by tribological measures. This ready reference and handbook provides an analysis of the most important tribosystems using modern test equipment in laboratories and test fields, the latest results in material selection and wear protection by special coatings and surface engineering, as well as with lubrication and lubricants.This result is a quick introductio

  10. INVESTIGATION OF TRIBOLOGICAL PROPERTIES CuSn10 BEARING MATERIAL

    Directory of Open Access Journals (Sweden)

    Bekir Sadık ÜNLÜ

    2005-01-01

    Full Text Available Bronzes which copper based alloys is widely used because of properties physical, thermal and tribological as journal bearing material. This material that has tribological performance good conclusions gives at journal bearings. In this study, CuSn10 bronze that were manufactured journal bearings friction and wear properties has been examined and compared. SAE 1050 steel shaft has been used as counter abrader. Experiments have been carried out 10 N and 20 N loads, 750 and 1500 rpm, dry and lubricated conditions by using radial journal bearing wear test rig. As a results, high friction coefficient and weigh loss have been obtained at dry condition more than lubricated condition.

  11. Research of Tribological Behaviors of a New Aluminum Bronze

    Institute of Scientific and Technical Information of China (English)

    XU Jian-lin; WANG Zhi-ping; CHEN Chao

    2004-01-01

    The tribological behaviors were investigated in a new high strength and wear resistant aluminum bronze, with its friction coefficient and wear-rate lower than those of ZQAl9-4 and ZQAl10-4-4 alloys in terms of Chinese national standard.The results showed that different tribological behaviors were attributed material itself. Under boundary lubrication condition, major wear mechanisms of aluminum bronze are adhesive wear and attrition wear. Its wearability depends mainly on material microstructure, shedding hard-particles, rakes and small pits that can store lubricant. The new aluminum bronze may find wide application in high sliding speed, heavy load and boundary lubrication condition.

  12. Research of Tribological Behaviors of a New Aluminum Bronze

    Institute of Scientific and Technical Information of China (English)

    XUJian-lin; WANGZhi-ping; CHENChao

    2004-01-01

    The tribological behaviors were investigated in a new high strength and wear resistant alurninum bronze, with its friction coefficient and wear-rate lower than those of ZQA19-4 and ZQAI10-4-4 alloys in terms of Chinese national standard. The results showed that different tribological behaviors were attributed material itself. Under boundary lubrication condition, major wear mechanisms of aluminum bronze are adhesive wear and attrition wear. Its. wearability depends mainly on material microstructure, shedding hard-particles, rakes and small pits that can store lubricant. The new aluminum bronze may find wide application in high sliding speed, heavy load and boundaty lubrication condition.

  13. Tribological researches of polimer-metal couples in environments

    Directory of Open Access Journals (Sweden)

    R. Kaczyński

    2010-01-01

    Full Text Available In the paper the results of experimental researches carried out for polymer strengthened carbon fibres-metal couple were presented. The binary scheme of surface layer’s wear in microarea was assumed.The attempt of kinetic’s analysis between matrix and filler with taking into consideration percentage share was carried out. The experiment were done using tribological model such as: probe-pin and antiprobe-disk. Qualitative and quantitative dependences of tribological couples in water and oil environment were determined.

  14. Surface Diagnostics in Tribology Technology and Advanced Coatings Development

    Science.gov (United States)

    Miyoshi, Kazuhisa

    1999-01-01

    This paper discusses the methodologies used for surface property measurement of thin films and coatings, lubricants, and materials in the field of tribology. Surface diagnostic techniques include scanning electron microscopy, transmission electron microscopy, atomic force microscopy, stylus profilometry, x-ray diffraction, electron diffraction, Raman spectroscopy, Rutherford backscattering, elastic recoil spectroscopy, and tribology examination. Each diagnostic technique provides specific measurement results in its own unique way. In due course it should be possible to coordinate the different pieces of information provided by these diagnostic techniques into a coherent self-consistent description of the surface properties. Examples are given on the nature and character of thin diamond films.

  15. Engineered CVD Diamond Coatings for Machining and Tribological Applications

    Science.gov (United States)

    Dumpala, Ravikumar; Chandran, Maneesh; Ramachandra Rao, M. S.

    2015-07-01

    Diamond is an allotropes of carbon and is unique because of its extreme hardness (~100 GPa), low friction coefficient (fracture toughness can be tuned by controlling the grain size of the coatings from a few microns to a few nanometers. In this review, characteristics and performance of the CVD diamond coatings deposited on cemented tungsten carbide (WC-Co) substrates were discussed with an emphasis on WC-Co grade selection, substrate pretreatment, nanocrystallinity and microcrystallinity of the coating, mechanical and tribological characteristics, coating architecture, and interfacial adhesion integrity. Engineered coating substrate architecture is essential for CVD diamond coatings to perform well under harsh and highly abrasive machining and tribological conditions.

  16. A Thickened Coracohumeral Ligament and Superomedial Capsule Limit Internal Rotation of the Shoulder Joint: Report of Three Cases

    Directory of Open Access Journals (Sweden)

    Masashi Koide

    2016-01-01

    Full Text Available Adhesive capsulitis of the shoulder (also known as frozen shoulder is a painful and disabling disorder with an estimated prevalence ranging from 2% to 5% in the general population. Although the precise pathogenesis of frozen shoulder is unclear, thickened capsule and coracohumeral ligament (CHL have been documented to be one of the most specific manifestations. The thickened CHL has been understood to limit external rotation of the shoulder, and restriction of internal rotation of the shoulder has been believed to be related to posterior capsular tightness. In this paper, three cases of refractory frozen shoulder treated through arthroscopic release of a contracted capsule including CHL were reported. Two cases in which there is recalcitrant severe restriction of internal rotation after manipulation under anesthesia (MUA were finally treated with arthroscopic surgery. Although MUA could release the posterior capsule, internal rotation did not improve in our cases. After release of the thickened CHL, range of motion of internal rotation was significantly improved. This report demonstrates the role of the thickened CHL in limiting the internal rotation of the shoulder. We highlight the importance of release of thickened CHL in addition to the pancapsular release, in case of severe limitation of internal rotation of shoulder.

  17. Report on the SNL/NSF International Workshop on Joint Mechanics, Arlington, Virginia, 16-18 October 2006.

    Energy Technology Data Exchange (ETDEWEB)

    Ewins, David J. (Imperial College, London England, UK); Bergman, Lawrence A. (University of Illinois, Urbana, IL); Segalman, Daniel Joseph

    2007-11-01

    The NSF/SNL joint mechanics workshop, held in Arlington, Virginia, 16-18 October, 2006, attempted to assess the current state of the art for modeling joint mechanics for the purpose of structural dynamics calculation, to identify the underlying physics issues that must be addressed to advance the field, and to propose a path forward. Distinguished participants from several countries representing research communities that focus on very different length and time scales identified multiple challenges in bridging those scales. Additionally, two complementary points of view were developed for addressing those challenges. The first approach - the 'bottom-up' perspective - attempts to bridge scales by starting from the smallest length scale and working up. The other approach starts at the length scale of application and attempts to deduce mechanics at smaller length scales through reconciliation with laboratory observation. Because interface physics is a limiting element of predictive simulation in defense and transportation, this issue will be of continuing importance for the foreseeable future.

  18. 人工智能国际研究进展——第17届国际人工智能联合大会评述%Advances of International Artificial Intelligence Research ——Report of 17th International Joint Conference on Artificial Intelligence

    Institute of Scientific and Technical Information of China (English)

    周志华; 史忠植

    2001-01-01

    This report briefly introduces the 17th International Joint Conference on Artificial Intelligence (IJCAI-01), including the issued awards, technical programs, and other activities. Also some is sues of future research directions are involved.

  19. TRIBOLOGICAL PERFORMANCE OF PISTON RING IN MARINE DIESEL ENGINE

    DEFF Research Database (Denmark)

    Imran, Tajammal; Klit, Peder; Felter, Christian

    From a tribology point of view, it is the two dead centers that are the main area of interest for experimental study of piston rings in large marine diesel engines. Therefore, in this work the performance of piston rings is studied to mark the importance of the two dead centers. A test rig based...

  20. Functional surfaces for tribological applications: inspiration and design

    Science.gov (United States)

    Abdel-Aal, Hisham A.

    2016-12-01

    Surface texturing has been recognized as a method for enhancing the tribological properties of surfaces for many years. Adding a controlled texture to one of two faces in relative motion can have many positive effects, such as reduction of friction and wear and increase in load capacity. To date, the true potential of texturing has not been realized not because of the lack of enabling texturing technologies but because of the severe lack of detailed information about the mechanistic functional details of texturing in a tribological situation. Experimental as well as theoretical analysis of textured surfaces define important metrics for performance evaluation. These metrics represent the interaction between geometry of the texturing element and surface topology. To date, there is no agreement on the optimal values that should be implemented given a particular surface. More importantly, a well-defined methodology for the generation of deterministic textures of optimized designs virtually does not exist. Nature, on the other hand, offers many examples of efficient texturing strategies (geometries and topologies) specifically applied to mitigate frictional effects in a variety of situations. Studying these examples may advance the technology of surface engineering. This paper therefore, provides a comparative review of surface texturing that manifest viable synergy between tribology and biology. We attempt to provide successful emerging examples where borrowing from nature has inspired viable surface solutions that address difficult tribological problems both in dry and lubricated contact situations.

  1. Application of quartz crystal microbalance technology in tribological investigation

    Science.gov (United States)

    The last fifteen years have seen considerable growth in the application of quartz crystal microbalance (QCM) to explore the tribological characteristics of materials. This article reviews some of the advances made in characterizing frictional properties of materials using the QCM, especially with di...

  2. Tribological properties of nanoscale alumina-zirconia composites

    NARCIS (Netherlands)

    Kerkwijk, B.; Winnubst, A.J.A.; Verweij, H.; Mulder, E.J.; Metselaar, H.S.C.; Schipper, D.J.

    1999-01-01

    The tribological properties of zirconia (Y-TZP), alumina and their composites, alumina dispersed in zirconia (ADZ) and zirconia-toughened alumina (ZTA), were investigated. These ceramics are made by colloidal processing methods such that well-defined, homogeneous microstructures with submicron grain

  3. Optimization of a tribological properties of friction pairs

    Science.gov (United States)

    Dyshlovenko, S. S.; Frolov, N. D.; Kouzmin, Yr. P.; Veiko, Vadim P.

    2003-11-01

    This paper is devoted to analysis of correlation between surface microgeometry and tribological properties of friction pairs. Two experimental methods have been applied for surface microstructuring: vibrorolling and laser ablation. Dependence of different in-service characteristics on groove area has been done. Production examples are demonstrated. Preliminary comparison of laser and mechanical structuring is carried out.

  4. Tribology of Carbon-Based Coatings : Past, Present, and Future

    OpenAIRE

    Broitman, Esteban; Hultman, Lars

    2013-01-01

    In this talk, the development of carbon-based coatings will be reviewed. The most recent findings in the synthesis, characterization and application of carbon-based coatings will be highlighted. Future perspectives of new fullerene-like carbon-based tribological coatings will be discussed. Novel applications of fullerene-like CNx, CPx, and CFx will be envisioned.

  5. Effect of Elevated Temperature on Tribological Properties of PVD Layers

    Directory of Open Access Journals (Sweden)

    Mária HAGAROVÁ

    2016-05-01

    Full Text Available The present study investigated tribological properties of multilayer TiAlN and nanocomposite (nc-Ti1-xAlxN/a-Si3N4 coatings. Tested coatings were deposited by two PVD methods on the high speed steel Böhler S 600 Isorapid substrate. The coatings demonstrated good adhesion to the substrate and high hardness (2090 - 2510 HV0.5. Tribological properties of the coated specimens were evaluated by the Ball-on-Disc test and by metallographical analysis of the tribological track after testing at room temperature and at 450°C. The specimens with multilayer TiAlN coatings showed slightly better tribological properties, as regards the course of friction coefficient. Although the values of friction coefficient of multilayer coatings were comparable to the values determined for nanocomposite, the course of friction coefficient and analysis of tribo-tracks showed that the failure of the multilayer TiAlN coating was less pronounced compared to the nanocomposite coating.

  6. Activities report of the European Space Tribology Laboratory

    Science.gov (United States)

    Walton, A. J.

    1984-08-01

    Tribology tests on satellite solar arrays are summarized. Developments in slip ring technology; fluorinated oils; friction and wear of gears and solid lubricant coatings; contact bearings; sintered bronze cages for use in lead ion-plated bearings; titanium nitride ion-plated coatings; and a pointing mechanism test facility are discussed.

  7. Open System Tribology and Influence of Weather Condition.

    Science.gov (United States)

    Lyu, Yezhe; Bergseth, Ellen; Olofsson, Ulf

    2016-08-30

    The tribology of an open system at temperatures ranging between 3 °C and -35 °C, with and without snow, was investigated using a pin-on-disc tribometer mounted in a temperature-controlled environmental chamber. The relationship between the microstructure and ductility of the materials and the tribology at the contacting surfaces was investigated. The study shows that during continuous sliding, pressure causes snow particles to melt into a liquid-like layer, encouraging the generation of oxide flakes on the contact path. The friction coefficient and wear rate are dramatically reduced through an oxidative friction and wear mechanism. In the absence of snow, the tribological process is controlled by the low temperature brittleness of steel in the temperature range from 3 °C to -15 °C. At these temperatures, cracks are prone to form and extend on the worn surfaces, resulting in the spalling of bulk scraps, which are crushed into debris that increases the friction coefficient and wear rate due to strong abrasion. When the temperature falls to -25 °C, an ice layer condenses on the metal surfaces and relaxes the tribological process in the same way as the added snow particles, which significantly decreases the friction and wear.

  8. Partitioning of knee joint internal forces in gait is dictated by the knee adduction angle and not by the knee adduction moment.

    Science.gov (United States)

    Adouni, M; Shirazi-Adl, A

    2014-05-01

    Medial knee osteoarthritis is a debilitating disease. Surgical and conservative interventions are performed to manage its progression via reduction of load on the medial compartment or equivalently its surrogate measure, the external adduction moment. However, some studies have questioned a correlation between the medial load and adduction moment. Using a musculoskeletal model of the lower extremity driven by kinematics-kinetics of asymptomatic subjects at gait midstance, we aim here to quantify the relative effects of changes in the knee adduction angle versus changes in the adduction moment on the joint response and medial/lateral load partitioning. The reference adduction rotation of 1.6° is altered by ±1.5° to 3.1° and 0.1° or the knee reference adduction moment of 17Nm is varied by ±50% to 25.5Nm and 8.5Nm. Quadriceps, hamstrings and tibiofemoral contact forces substantially increased as adduction angle dropped and diminished as it increased. The medial/lateral ratio of contact forces slightly altered by changes in the adduction moment but a larger adduction rotation hugely increased this ratio from 8.8 to a 90 while in contrast a smaller adduction rotation yielded a more uniform distribution. If the aim in an intervention is to diminish the medial contact force and medial/lateral load ratio, a drop of 1.5° in adduction angle is much more effective (causing respectively 12% and 80% decreases) than a reduction of 50% in the adduction moment (causing respectively 4% and 13% decreases). Substantial role of changes in adduction angle is due to the associated alterations in joint nonlinear passive resistance. These findings explain the poor correlation between knee adduction moment and tibiofemoral compartment loading during gait suggesting that the internal load partitioning is dictated by the joint adduction angle.

  9. Tribological characterization of zirconia coatings deposited on Ti6Al4V components for orthopedic applications.

    Science.gov (United States)

    Berni, M; Lopomo, N; Marchiori, G; Gambardella, A; Boi, M; Bianchi, M; Visani, A; Pavan, P; Russo, A; Marcacci, M

    2016-05-01

    One of the most important issues leading to the failure of total joint arthroplasty is related to the wear of the plastic components, which are generally made of ultra high molecular weight polyethylene (UHMWPE). Therefore, the reduction of joint wear represents one of the main challenges the research in orthopedics is called to address nowadays. Surface treatments and coatings have been recognized as innovative methods to improve tribological properties, also in the orthopedic field. This work investigated the possibility to realize hard ceramic coatings on the metal component of a prosthesis, by means of Pulsed Plasma Deposition, in order to reduce friction and wear in the standard coupling against UHMWPE. Ti6Al4V substrates were coated with a 2 μm thick yttria-stabilized zirconia (YSZ) layer. The mechanical properties of the YSZ coatings were assessed by nanoindentation tests performed on flat Ti6Al4V substrates. Tribological performance was evaluated using a ball-on-disk tribometer in dry and lubricated (i.e. with fetal bovine serum) highly-stressing conditions, up to an overall distance of 10 km. Tribology was characterized in terms of coefficient of friction (CoF) and wear rate of the UHMWPE disk. After testing, specimens were analyzed through optical microscopy and SEM images, in order to check the wear degradation mechanisms. Progressive loading scratch tests were also performed in dry and wet conditions to determine the effects of the environment on the adhesion of the coating. Our results supported the beneficial effect of YSZ coating on metal components. In particular, the proposed solution significantly reduced UHMWPE wear rate and friction. At 10 km of sliding distance, a wear rate reduction of about 18% in dry configuration and of 4% in presence of serum, was obtained by the coated group compared to the uncoated group. As far as friction in dry condition is concerned, the coating allowed to maintain low CoF values until the end of the tests, with an

  10. Mechanism of Radial Redistribution of Energetic Trapped Ions Due to m=2/n=1 Internal Reconnection in Joint European Torus Shear Optimized Plasmas

    Energy Technology Data Exchange (ETDEWEB)

    N.N. Gorelenkov; A. Gondhalekar; A.A. Korotkov; S.E. Sharapov; D. Testa; and Contributors to the EFDA-JET Workprogramme

    2002-01-18

    Internal radial redistribution of MeV energy ICRF-driven hydrogen minority ions was inferred from neutral particle analyzer measurements during large amplitude MHD activity leading to internal reconnection in Shear Optimized plasmas in the Joint European Torus (JET). A theory is developed for energetic ion redistribution during a reconnection driven by an m=2/n=1 internal kink mode. Plasma motion during reconnection generates an electric field which can change the energy and radial position of the energetic ions. The magnitude of ion energy change depends on the value of the safety factor at the plasma core from which the energetic ions are redistributed. A relation is found for corresponding change in canonical momentum. P(subscript phi), which leads to radial displacement of the ions. The model yields distinctive new features of energetic ion redistribution under such conditions. Predicted characteristics of ion redistribution are compared with the NPA measurements, and good correlation is found. Sometimes fast ions were transported to the plasma edge due to interaction with a long-lived magnetic island which developed after the reconnection and had chirping frequency in the laboratory frame. Convection of resonant ions trapped in a radially moving phase-space island is modeled to understand the physics of such events.

  11. Research on the Personal Safety Work for Female Nurs-ing Interns through Joint Forces%形成合力做好护理专业实习女生人身安全工作研究

    Institute of Scientific and Technical Information of China (English)

    万英; 冉丽; 李志强; 姚本丽

    2016-01-01

    从恩格斯的“历史合力论”原理出发,引申出护理专业实习女生人身安全工作需要学校、实习单位、家长、实习生、其他力量、辅导员等形成合力,并且减少合力中的消极因素,确保护理专业实习女生人身安全得到有效保障。%According to Engels' history with joint forces theory, this paper extends the meaning that the personal safety work for female nursing interns needs the joint forces of the college, prac-tice sites, parents, interns themselves, counselors and other forces, and negative factors in the joint forces should be reduced, in order to effectively ensure the personal safety of female nursing interns.

  12. Pharmaceutical interventions by collaboration between staff pharmacists and clinical pharmacists and implementation of Joint Commission International Accreditation Standards on medication use may optimize pharmacotherapy in geriatric patients

    Directory of Open Access Journals (Sweden)

    Chen M

    2016-11-01

    Full Text Available Meng Chen, Quan Zhou Department of Pharmacy, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang Province, People’s Republic of ChinaWe read with great interest the prospective study by Cortejoso et al,1 which describes the characteristics of pharmaceutical interventions in two geriatric wards (orthogeriatric ward and geriatric day unit of a general teaching hospital. We strongly agree with their finding that shows the importance of clinical pharmacist involvement in the optimization of pharmacotherapy in elderly patients. Furthermore, we especially appreciate their new and interesting findings that the clinical pharmacist was more frequently requested by physicians and nurses for information about the pharmacotherapy of the patients on the geriatric day unit, compared with the orthogeriatric ward at admission and discharge (5.7% vs 1.2% and 1.7%, respectively, P<0.05, and that the pharmacist asked for more confirmation of the physician orders on the geriatric day unit rather than the orthogeriatric ward (19.8% vs 1.8% and 15.7% at admission and discharge, respectively, P<0.05. We are from a Joint Commission International (JCI-accredited academic medical center hospital with 3200 beds in China. Safe medication management and use are pivotal to patient safety and quality of care on which the state-of-the-art standards of the Joint Commission focus. We would like to share our perspectives in the following paragraphs.View original paper by Cortejoso and colleagues. 

  13. Microstructural Characterization of Internal Welding Defects and Their Effect on the Tensile Behavior of FSW Joints of AA2198 Al-Cu-Li Alloy

    Science.gov (United States)

    Le Jolu, Thomas; Morgeneyer, Thilo F.; Denquin, Anne; Sennour, Mohamed; Laurent, Anne; Besson, Jacques; Gourgues-Lorenzon, Anne-Françoise

    2014-11-01

    Internal features and defects such as joint line remnant, kissing bond, and those induced by an initial gap between the two parent sheets were investigated in AA2198-T851 friction stir welded joints. They were compared with the parent material and to defect-free welds obtained using a seamless sheet. The cross-weld tensile strength was reduced by the defects by less than 6 pct. The fracture elongation was not significantly affected in view of experimental scatter. Fracture location, however, changed from the thermomechanically affected zone (retreating side) to the defect in the weld nugget for the welds bearing a kissing bond and for some of the gap welds. The kissing bond was shown by EBSD to be an intergranular feature; it fractured under a normal engineering stress close to 260 MPa during an in situ SEM tensile test. Synchrotron tomography after interrupted tensile testing confirmed opening of the kissing bond. For an initial gap of 23 pct of the sheet thickness, intergranular fracture of copper-enriched or oxide-bearing grain boundaries close to the nugget root was evidenced. The stress and strain state of cross-weld specimens loaded under uniaxial tension was assessed using a 3D finite element, multi-material model, determined on the basis of experimental data obtained on the same specimens using digital image correlation.

  14. TRIBOLOGY OF BIO-INSPIRED NANOWRINKLED FILMS ON ULTRASOFT SUBSTRATES

    Directory of Open Access Journals (Sweden)

    Juergen M. Lackner

    2013-03-01

    Full Text Available Biomimetic design of new materials uses nature as antetype, learning from billions of years of evolution. This work emphasizes the mechanical and tribological properties of skin, combining both hardness and wear resistance of its surface (the stratum corneum with high elasticity of the bulk (epidermis, dermis, hypodermis. The key for combination of such opposite properties is wrinkling, being consequence of intrinsic stresses in the bulk (soft tissue: Tribological contact to counterparts below the stress threshold for tissue trauma occurs on the thick hard stratum corneum layer pads, while tensile loads smooth out wrinkles in between these pads. Similar mechanism offers high tribological resistance to hard films on soft, flexible polymers, which is shown for diamond-like carbon (DLC and titanium nitride thin films on ultrasoft polyurethane and harder polycarbonate substrates. The choice of these two compared substrate materials will show that ultra-soft substrate materials are decisive for the distinct tribological material. Hierarchical wrinkled structures of films on these substrates are due to high intrinsic compressive stress, which evolves during high energetic film growth. Incremental relaxation of these stresses occurs by compound deformation of film and elastic substrate surface, appearing in hierarchical nano-wrinkles. Nano-wrinkled topographies enable high elastic deformability of thin hard films, while overstressing results in zigzag film fracture along larger hierarchical wrinkle structures. Tribologically, these fracture mechanisms are highly important for ploughing and sliding of sharp and flat counterparts on hard-coated ultra-soft substrates like polyurethane. Concentration of polyurethane deformation under the applied normal loads occurs below these zigzag cracks. Unloading closes these cracks again. Even cyclic testing do not lead to film delamination and retain low friction behavior, if the adhesion to the substrate is high

  15. Tribology of bio-inspired nanowrinkled films on ultrasoft substrates.

    Science.gov (United States)

    Lackner, Juergen M; Waldhauser, Wolfgang; Major, Lukasz; Teichert, Christian; Hartmann, Paul

    2013-01-01

    Biomimetic design of new materials uses nature as antetype, learning from billions of years of evolution. This work emphasizes the mechanical and tribological properties of skin, combining both hardness and wear resistance of its surface (the stratum corneum) with high elasticity of the bulk (epidermis, dermis, hypodermis). The key for combination of such opposite properties is wrinkling, being consequence of intrinsic stresses in the bulk (soft tissue): Tribological contact to counterparts below the stress threshold for tissue trauma occurs on the thick hard stratum corneum layer pads, while tensile loads smooth out wrinkles in between these pads. Similar mechanism offers high tribological resistance to hard films on soft, flexible polymers, which is shown for diamond-like carbon (DLC) and titanium nitride thin films on ultrasoft polyurethane and harder polycarbonate substrates. The choice of these two compared substrate materials will show that ultra-soft substrate materials are decisive for the distinct tribological material. Hierarchical wrinkled structures of films on these substrates are due to high intrinsic compressive stress, which evolves during high energetic film growth. Incremental relaxation of these stresses occurs by compound deformation of film and elastic substrate surface, appearing in hierarchical nano-wrinkles. Nano-wrinkled topographies enable high elastic deformability of thin hard films, while overstressing results in zigzag film fracture along larger hierarchical wrinkle structures. Tribologically, these fracture mechanisms are highly important for ploughing and sliding of sharp and flat counterparts on hard-coated ultra-soft substrates like polyurethane. Concentration of polyurethane deformation under the applied normal loads occurs below these zigzag cracks. Unloading closes these cracks again. Even cyclic testing do not lead to film delamination and retain low friction behavior, if the adhesion to the substrate is high and the initial

  16. EDITORIAL: Theory of fusion plasmas: selected papers from the Joint Varenna-Lausanne International Workshop Theory of fusion plasmas: selected papers from the Joint Varenna-Lausanne International Workshop

    Science.gov (United States)

    Garbet, X.; Sauter, O.

    2011-05-01

    The 2010 edition of the joint Varenna-Lausanne workshop on the theory of fusion plasmas was undoubtedly a great success. The programme encompasses a wide variety of topics, namely turbulence, MHD, edge physics and RF wave heating. The present PPCF issue is a collection of 19 outstanding papers, which cover these topics. It follows the publication of 22 refereed contributed papers in Journal of Physics: Conference Series 2010 260. There is no doubt that the production of articles was both abundant and of high scientific quality. This is why the Varenna-Lausanne meeting takes an important place in the landscape of conferences on fusion. Indeed this is the ideal forum for exchanging ideas on theory and modelling, and for substantiating the best results obtained in our field. The tradition of the meeting is to provide a forum for numerical modelling activities. This custom was clearly respected given the large fraction of papers in this special issue which address this subject. This feature reflects the revolution we have been living through for some years with the fast growth of high-performance computers. It also appears that analytical theory is flourishing. This is important for bringing new ideas and guidance to numerical simulations. Finally, code validation and comparison to experiments are well represented. We believe that this is good news given the complexity of the non-linear physics that is at stake in fusion devices. Another subject of satisfaction was the presence of many young scientists at the meeting. The encounter between young researchers and senior scientists is certainly a strong point of the Varenna-Lausanne conference. In conclusion, we anticipate a great success for this special issue of PPCF and we hope that the readers will find therein ideas and inspiration.

  17. Liquid crystals in biotribology synovial joint treatment

    CERN Document Server

    Ermakov, Sergey; Eismont, Oleg; Nikolaev, Vladimir

    2016-01-01

    This book summarizes the theoretical and experimental studies confirming the concept of the liquid-crystalline nature of boundary lubrication in synovial joints. It is shown that cholesteric liquid crystals in the synovial liquid play a significant role in the mechanism of intra-articular friction reduction. The results of structural, rheological and tribological research of the creation of artificial synovial liquids - containing cholesteric liquid crystals in natural synovial liquids - are described. These liquid crystals reproduce the lubrication properties of natural synovia and provide a high chondroprotective efficiency. They were tested in osteoarthritis models and in clinical practice.

  18. Publication Trends and Citation Impact of Tribology Research in India: A Scientometric Study

    Directory of Open Access Journals (Sweden)

    Rajendran, P.

    2014-03-01

    Full Text Available This paper analyzes India's contribution to world tribology research during the period 2001-2012 based on SCOPUS records. India's global publication share, annual output, and its citation impact of Indian contribution, partner countries, leading contributors, leading institutes, and highly cited papers were analyzed. Additionally, a cloud technique is used to map frequently used single words in titles. It is observed that India ranks in the $7^{th}$ position with a global publication share of 3.83% and an annual average growth rate of 25.58% during the period 2001-2012. The citation impact of India's contribution is 6.05 which decreased from 12.74 during 2001-2006 to 4.62 during 2007-2012. 17.4% of India's total research output was published with international collaboration.

  19. A novel tribological study on DLC-coated micro-dimpled orthopedics implant interface.

    Science.gov (United States)

    Choudhury, Dipankar; Urban, Filip; Vrbka, Martin; Hartl, Martin; Krupka, Ivan

    2015-05-01

    This study investigates a tribological performance of diamond like carbon (DLC) coated micro dimpled prosthesis heads against ceramic cups in a novel pendulum hip joint simulator. The simulator enables determining friction coefficient and viscous effects of a concave shaped specimen interface (conformal contact). Two types of DLC such as hydrogenated amorphous carbon (a-C:H) and tetrahedral amorphous carbon (Ta-C) and one set of micro dimple (diameter of 300µm, depth of 70µm, and pitch of 900µm) were fabricated on metallic prosthesis heads. The experiment results reveal a significant friction coefficient reduction to the 'dimpled a-C:H/ceramic' prosthesis compared to a 'Metal (CoCr)/ceramic' prosthesis because of their improved material and surface properties and viscous effect. The post-experiment surface analysis displays that the dimpled a-C:H yielded a minor change in the surface roughness, and generated a larger sizes of wear debris (40-200nm sized, equivalent diameter), a size which could be certainly stored in the dimple, thus likely to reducing their possible third body abrasive wear rate. Thus, dimpled a:C-H can be used as a 'metal on ceramic hip joint interface', whereas the simulator can be utilized as an advanced bio-tribometer. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. Development of Advanced In-Cylinder Components and Tribological Systems for Low Heat Rejection Diesel Engines

    Science.gov (United States)

    Yonushonis, T. M.; Wiczynski, P. D.; Myers, M. R.; Anderson, D. D.; McDonald, A. C.; Weber, H. G.; Richardson, D. E.; Stafford, R. J.; Naylor, M. G.

    1999-01-01

    In-cylinder components and tribological system concepts were designed, fabricated and tested at conditions anticipated for a 55% thermal efficiency heavy duty diesel engine for the year 2000 and beyond. A Cummins L10 single cylinder research engine was used to evaluate a spherical joint piston and connecting rod with 19.3 MPa (2800 psi) peak cylinder pressure capability, a thermal fatigue resistant insulated cylinder head, radial combustion seal cylinder liners, a highly compliant steel top compression ring, a variable geometry turbocharger, and a microwave heated particulate trap. Components successfully demonstrated in the final test included spherical joint connecting rod with a fiber reinforced piston, high conformability steel top rings with wear resistant coatings, ceramic exhaust ports with strategic oil cooling and radial combustion seal cylinder liner with cooling jacket transfer fins. A Cummins 6B diesel was used to develop the analytical methods, materials, manufacturing technology and engine components for lighter weight diesel engines without sacrificing performance or durability. A 6B diesel engine was built and tested to calibrate analytical models for the aluminum cylinder head and aluminum block.

  1. [Which hip articulation bearing for which patient? : Tribology of the future].

    Science.gov (United States)

    Morlock, M M; Bishop, N; Kaddick, C

    2011-12-01

    Replacement of the hip joint has become an exceptionally successful procedure since the inauguration of the low friction principle by Charnley. Aseptic osteolysis and joint dislocation have been addressed by the development of wear-optimized materials and the introduction of larger heads. As an increase in head diameter against polyethylene causes wear increase, larger hard-on-hard bearings were introduced, which exhibit reduced wear and reduced dislocation risk with increasing head diameter. These findings were derived from standard simulator testing, not sufficiently considering the risk of fluid film breakdown under adverse conditions, which can cause a dramatic increase in wear and friction proportional to the head diameter. Such adverse conditions can occur clinically in patients due to several factors and have caused the presently observed unexpected problems with these new designs. Standardized preclinical testing has to be viewed as a minimum requirement but certainly not as a guarantee for the clinical success of new materials and designs even if the testing is adapted to the current patient requirements, which is presently not the case. The future of tribology lies in the prevention of adverse conditions in patients, the improvement and optimized use of proven existing materials and not in the use of new materials.

  2. Primary subtalar joint arthrodesis with internal and external fixation for the repair of a diabetic comminuted calcaneal fracture.

    Science.gov (United States)

    Facaros, Zacharia; Ramanujam, Crystal L; Zgonis, Thomas

    2011-01-01

    Comminuted, intra-articular calcaneal fractures can cause severe lower extremity impairment and have devastating effects on a patient's well being. Diabetes is a multisystem process that may cause neuropathy and loss of protective sensation further complicating the prognosis. Not all calcaneal fractures are created equal and when considering the patient's overall presentation and extent of injury, the combined approach of internal and external fixation for fracture reduction may be beneficial for restoration of anatomic alignment and function. Copyright © 2011 Elsevier Inc. All rights reserved.

  3. Influence of surface PMPC brushes on tribological and biocompatibility properties of UHMWPE

    Energy Technology Data Exchange (ETDEWEB)

    Xiong, Dangsheng, E-mail: xiongds@163.com; Deng, Yaling; Wang, Nan; Yang, Yuanyuan

    2014-04-01

    Graphical abstract: - Highlights: • Wettability and blood compatibility of PMPC-grafted UHMWPE were improved. • The friction properties including the short and long term under high contact stress were investigated. • The PMPC brushes were sheared off from the surface with the increase of sliding cycles. - Abstract: Extremely efficient lubrication has been observed between natural joint surfaces and the friction coefficients can reach as low as 0.001. However, attaining the ultra-low friction coefficients between articulating cartilage surfaces in any artificial joints remains a challenge for bio-tribologists. In order to obtain the ultra-low friction coefficients as in natural joints, a biomimetic zwitterionic monomer 2-methacryloyloxyethyl phosphorylcholine (MPC) was grafted on the ultra high molecular weight polyethylene (UHMWPE) by UV radiation and self-polymerized to form brush-like structure. The results of total reflection (FT-IR/ATR) spectra and X-ray photoelectron spectroscopy (XPS) spectra indicated successful grafting of PMPC on to the UHMWPE surface (Polymerization of 2-methacryloyloxyethyl phosphorylcholine). The water contact angle of UHMWPE decreased from 80° to 15° after grafting PMPC for 45 min. Tribological properties were tested under high contact stress for a longer duration of time. The friction coefficient of the sample grafted with PMPC was found to be much lower than that of untreated UHMWPE at initial stage which increased gradually with the increase of the cycle till it attained the same level as that observed for untreated UHMWPE. The wear rate of modified samples was decreased by 37% and 46% in distilled water and saline, respectively. The highly hydrated PMPC layer provided efficient lubrication at the interface between the sliding couple leading to wear reduction of UHMWPE. Furthermore, blood compatibility of modified artificial joint materials was improved significantly, which has been attributed to the properties and

  4. Tribology of polymeric nanocomposites friction and wear of bulk materials and coatings

    CERN Document Server

    Friedrich, Klaus

    2013-01-01

    Tribology of Polymeric Nanocomposites provides a comprehensive description of polymeric nanocomposites, both as bulk materials and as thin surface coatings, and provides rare, focused coverage of their tribological behavior and potential use in tribological applications. Providing engineers and designers with the preparation techniques, friction and wear mechanisms, property information and evaluation methodology needed to select the right polymeric nanocomposites for the job, this unique book also includes valuable real-world examples of polymeric nanocomposites in a

  5. Morphological study in internal derangement of the temporomandibular joint with MRI. The relationships between the state of the articular disc and limitation of motion of the mandibular head

    Energy Technology Data Exchange (ETDEWEB)

    Miyazu, Hiroko; Sakurai, Takashi; Numayama, Sukenao; Furuya, Nobuaki; Kashima, Isamu [Kanagawa Dental Coll., Yokosuka (Japan)

    1997-12-01

    In this study, we used MRI to investigate the relationships between these factors in temporomandibular joint (TMJ) patients, especially with regard to the range of condylar movement. Bone configurations and articular disc conditions were analyzed in a total of 367 TMJ of 255 internal derangement patients using MRI. We examined the influence of articular disc condition on functional disorder and identified the tendencies of the pathology of patients with internal derangements. Anterolateral displacement was more frequent than anteromedial displacement, and lateral rotary displacement was more frequent than medial rotary displacement. Therefore, the articular disc displaced more readily laterally, rather than medially. With regard to the relationship between the articular disc configuration and reduction, enlargement of the posterior band and biconvex discs showed a tendency for articular disc displacement that did not reduce, while discs with even thickness showed a tendency of articular disc displacement which would reduce. Folding and biconvexity tended to limit condylar movement while less limitation occurred with discs of even thickness. In cases of disc displacement without reduction, there was a significantly higher percentage of cases with limited condylar movement than in cases of displacement with reduction. (K.H.)

  6. Joint trajectories for social and physical aggression as predictors of adolescent maladjustment: internalizing symptoms, rule-breaking behaviors, and borderline and narcissistic personality features.

    Science.gov (United States)

    Underwood, Marion K; Beron, Kurt J; Rosen, Lisa H

    2011-05-01

    This investigation examined the relation between developmental trajectories jointly estimated for social and physical aggression and adjustment problems at age 14. Teachers provided ratings of children's social and physical aggression in Grades 3, 4, 5, 6, and 7 for a sample of 255 children (131 girls, 21% African American, 52% European American, 21% Mexican American). Participants, parents, and teachers completed measures of the adolescent's adjustment to assess internalizing symptoms, rule-breaking behaviors, and borderline and narcissistic personality features. Results showed that membership in a high and rising trajectory group predicted rule-breaking behaviors and borderline personality features. Membership in a high desister group predicted internalizing symptoms, rule-breaking behaviors, and borderline and narcissistic personality features. The findings suggest that although low levels of social and physical aggression may not bode poorly for adjustment, individuals engaging in high levels of social and physical aggression in middle childhood may be at greatest risk for adolescent psychopathology, whether they increase or desist in their aggression through early adolescence.

  7. New directions in lubrication, materials, wear, and surface interactions - Tribology in the 80's

    Science.gov (United States)

    Loomis, W. R. (Editor)

    1985-01-01

    New directions in tribology are described. A range of topics is addressed, extending from fundamental research on tribological materials of all kinds and their surface effects, to final technological applications in mechanical components such as bearings, gears, and seals. The general topics addressed include: importance and definition of materials in tribology; future directions of research in adhesion and friction, wear and wear-resistant materials, and liquid lubricants and additives; status and new directions in elastohydrodynamic lubrication and solid lubricants; and tribological materials for mechanical components of the future.

  8. Novel tribological systems using shape memory alloys and thin films

    Science.gov (United States)

    Zhang, Yijun

    Shape memory alloys and thin films are shown to have robust indentation-induced shape memory and superelastic effects. Loading conditions that are similar to indentations are very common in tribological systems. Therefore novel tribological systems that have better wear resistance and stronger coating to substrate adhesion can be engineered using indentation-induced shape memory and superelastic effects. By incorporating superelastic NiTi thin films as interlayers between chromium nitride (CrN) and diamond-like carbon (DLC) hard coatings and aluminum substrates, it is shown that the superelasticity can improve tribological performance and increase interfacial adhesion. The NiTi interlayers were sputter deposited onto 6061 T6 aluminum and M2 steel substrates. CrN and DLC coatings were deposited by unbalanced magnetron sputter deposition. Temperature scanning X-ray diffraction and nanoindentation were used to characterize NiTi interlayers. Temperature scanning wear and scratch tests showed that superelastic NiTi interlayers improved tribological performance on aluminum substrates significantly. The two-way shape memory effect under contact loading conditions is demonstrated for the first time, which could be used to make novel tribological systems. Spherical indents in NiTi shape memory alloys and thin films had reversible depth changes that were driven by temperature cycling, after thermomechanical cycling, or one-cycle slip-plasticity deformation training. Reversible surface topography was realized after the indents were planarized. Micro- and nano- scale circular surface protrusions arose from planarized spherical indents in bulk and thin film NiTi alloy; line surface protrusions appeared from planarized scratch tracks. Functional surfaces with reversible surface topography can potentially result in novel tribological systems with reversible friction coefficient. A three dimensional constitutive model was developed to describe shape memory effects with slip

  9. Planning and implementing forest operations to achieve sustainable forests: Proceedings of papers presented at the joint meeting of the Council on Forest Engineering and International Union of Forest Research Organizations.

    Science.gov (United States)

    Charles R. Blinn; Michael A. Thompson

    1996-01-01

    Contains a variety of papers presented at the joint meeting of the Council on Forest Engineering and International Union of Forest Research Organizations Subject Group S3.04 and that support the meeting theme "Planning and Implementing Forest Operations to Achieve Sustainable Forests."

  10. Proceedings of the frst joint american chemical society agricultural and food chemistry division – american chemical society international chemical sciences chapter in Thailand symposium on agricultural and food chemistry

    Science.gov (United States)

    This Proceedings is a compilation of papers from contributed oral and poster presentations presented at the first joint symposium organized by the American Chemical Society Agricultural and Food Chemistry Division and the American Chemical Society International Chemical Sciences Chapter in Thailand ...

  11. The British Avant Garde: A Joint Venture Between the New York Cultural Center and Studio International Magazine

    Directory of Open Access Journals (Sweden)

    Jo Melvin

    2016-07-01

    Full Text Available This essay considers the relevance of The British Avant Garde exhibition at the New York Cultural Center in 1971 to the reputation and discussion of British artists in the US, and its subsequent impact in Britain. It situates the exhibition with reference to Conceptual Art and Conceptual Aspects at the NYCC and Information at the Museum of Modern Art, both held in 1970, and within the background milieu of a lively transatlantic and multi-directional network of artists such as Terry Atkinson, Michael Baldwin, Ian Burn, Barry Flanagan, Dan Graham, Joseph Kosuth, Christine Kozlov, Richard Long, Mel Ramsden, Sol LeWitt and Lawrence Weiner, who were developing alternative ways to make and to distribute work by using text, photocopies, and self-publication as forms of production as well as becoming the site of exhibition. Devised by Charles Harrison, assistant editor of Studio International magazine, the exhibition was a collaboration between the magazine and the NYCC, directed by Donald Karshan. Despite the mixed press reviews in New York, the exhibition paved the way for establishing institutional support for the artists in the UK.

  12. Investigation of tribological and mechanical properties of metal bearings

    Indian Academy of Sciences (India)

    Bekir Sadik Ünlü

    2009-08-01

    Copper, aluminum and tin–lead based alloys are widely used as journal bearing materials in tribological applications. Bronze and brass are widely used as journal bearing materials for copper based alloys. Zamacs find applications as journal bearing materials for zinc based alloys, while duralumines are chosen as journal bearing materials for aluminum based alloys. In addition, white metals are widely used as journal bearing materials for tin–lead based alloys. These alloys ensure properties expected from journal bearings. In this study, tribological and mechanical properties of these journal bearings manufactured by metals were investigated. SAE 1050 steel shaft was used as counter abrader. Experiments were carried out in every 30 min for a total of 150 min by using radial journal bearing wear test rig.

  13. Deposition and tribological behaviour of sputtered carbon hard coatings

    Energy Technology Data Exchange (ETDEWEB)

    Yang, S.; Camino, D.; Jones, A.H.S.; Teer, D.G. [Teer Coatings Ltd., Hartlebury (United Kingdom)

    2000-02-21

    The exceptional tribological properties of low deposition temperature sputtered carbon coatings (Graphit-iC coatings) have been recently reported. This paper describes the latest development of these coatings and particularly how, by an optimisation of the deposition parameters, it has been possible to obtain relative soft to very hard coatings with extremely low specific wear rates. The coatings have been deposited in a closed field unbalanced magnetron sputter ion plating (CFUBMSIP) installation. By applying the appropriate conditions of deposition, carbon coatings with hardness from 1500 to 4000 HV can be routinely deposited. Preliminary analytical results are presented in order to characterise such hard coatings: high-resolution transmission electron microscopy, scanning electron microscopy and X-ray diffraction analysis are some of the different techniques used for this work. Finally, a number of the applications are reported with tribological test results. (orig.)

  14. Tribological properties of OTS self-assembled monolayers

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Octadecyltrichlorosilane (OTS) self-assembled monolayers (SAMs)were prepared on the substrates of silicon and glass. The tribological properties were tested with a self-made point-contact pure sliding micro tribometer. The effect of humidity on the tribological properties of both OTS SAMs and the naked substrates were studied. When the substrate is covered by OTS monolayer, the friction coefficient is reduced from 0.5 to 0.1 and the stick-slip phenomenon is weakened. OTS monolayer can keep its friction coefficient steady in a wide range of humidity, because it is highly hydrophobic and thus not sensitive to humidity. In addition, the OTS monolayer has a considerable anti-wear ability.

  15. Tribological properties of oil-soluble samarium isooctoxyborate

    Institute of Scientific and Technical Information of China (English)

    黄伟九; 李芬芳; 彭成允; 刘丹; 贾进周; 陈美玲

    2002-01-01

    An oil-soluble rare earth compound, samarium isooctoxyborate, was synthesized and used as an antiwear and extreme pressure additive for lubricating oils. Its tribological performances were evaluated with a four-ball machine and a ring-on-block rig. In addition, surface analyses with Auger electron spectroscopy and X-ray photoelectron spectroscopy were also conducted to study the surface film formed by the additive under boundary lubrication conditions. The test results show that the additive exhibits good friction-reducing ability, good antiwear property and excellent extreme pressure performance. Surface analyses further disclose the coexistence of organic film, oxidation film and permeating film on the rubbing surface, which contributed to improve the tribological properties of the base oil.

  16. Tribological behaviour of unveneered and veneered lithium disilicate dental material.

    Science.gov (United States)

    Figueiredo-Pina, C G; Patas, N; Canhoto, J; Cláudio, R; Olhero, S M; Serro, A P; Ferro, A C; Guedes, M

    2016-01-01

    The friction and wear behaviour of a lithium disilicate dental ceramic against natural dental enamel is studied, including the effect of the presence of a fluorapatite veneering upon the tribological properties of the material. The tribological behaviour was assessed using reciprocating pin-on-plate test configuration, at pH 3 and pH 7. The surface energy of the plates was determined, as well as the zeta potential of fluorapatite, lithium disilicate and enamel particles in artificial saliva. It was found that the friction and wear behaviour of the tested enamel/plate material tribocouples is less severe in unveneered plates. Initial surface roughness of the plate does not affect wear results. However the topography of the resulting wear track affects the corresponding wear loss: a smoother final wear track is associated with lower wear. The surface topography of the wear track, and thus the tribological performance of the tested materials, is very sensitive to the pH of the sliding solution. This is because the dissolution trend, wettability and surface charge of the used materials are pH dependent. Overall friction and wear are higher under basic pH conditions, especially when plates are veneered. A wear model is proposed that correlates the effect of the described parameters with the observed tribological behaviour at pH 7. Attained results show that fluorapatite coating of lithium disilicate dental crowns affects tooth/crown wear behaviour, resulting in increased wear of both the artificial crown and the opposing natural teeth. Coating should therefore be avoided in occlusal crown surfaces.

  17. Composite sol-gel coatings on steel for tribological applications

    OpenAIRE

    Hermange, Kurt

    2016-01-01

    This thesis focuses on the elaboration and the characterization of composite sol-gel coatings “CSG” on austenitic stainless steelAISI 304. The aim of the thesis is to develop the process and to study the mechanical properties and tribological behavior of thecoatings. The first experimental part presents the optimization of the synthesis conditions of a stable alumina sol and the influence of the thermal treatment of the gel on the physic-chemical and thermostructural properties. The studied p...

  18. Tribology of ceramics and composites materials science perspective

    CERN Document Server

    Basu, Bikramjit

    2011-01-01

    This book helps students and practicing scientists alike understand that a comprehensive knowledge about the friction and wear properties of advanced materials is essential to further design and development of new materials. With important introductory chapters on the fundamentals, processing, and applications of tribology, the book then examines in detail the nature and properties of materials, the friction and wear of structural ceramics, bioceramics, biocomposites, and nanoceramics, as well as lightweight composites and the friction and wear of ceramics in a cryogenic environment.

  19. TEMPOROMANDIBULAR-JOINT OSTEOARTHROSIS AND GENERALIZED JOINT HYPERMOBILITY

    NARCIS (Netherlands)

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

    1992-01-01

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

  20. COMPARATIVE PERFORMANCE STUDY OF GASKETED AND NON-GASKETED FLANGE JOINTS UNDER COMBINED INTERNAL PRESSURE, AXIAL AND BENDING LOADING – AN EXPERIMENTAL STUDY

    Directory of Open Access Journals (Sweden)

    Muhammad Abid

    2010-11-01

    Full Text Available In this paper result of an extensive comparative experimental study of a gasketed and non-gasketed flange joint with different assemblies with different combined load combinations is carried out to investigate joint performance i.e. joint strength and sealing capability. Actual joint load capacities are determined under both the design and proof test pressure with maximum additional external loading (axial and bending that can be applied for safe joint performance. In addition, application of combined load is also discussed in the light of equivalent pressure approach.

  1. Investigation of tribological properties of composite C60-LB films

    Institute of Scientific and Technical Information of China (English)

    YANG Guanghong; ZHANG Xingtang; XUN Jun; JIANG Xiaohong; ZHANG Pingyu; DU Zuliang

    2006-01-01

    Composite C60-LB films were fabricated by the Langmuir-Blodgett (LB) technique, their micro- structures, micro- and macro-tribological properties were investigated using atomic force microscope/ friction force microscope (AFM/FFM). The results showed that in the confined C60-LB films there were two kinds of structures for the special C60 assembly: grain diameters of one kind were in the range of 150-230 nm; the other was smaller than 20 nm. Mi-cro-tribological studies showed that topographical images of tiny C60 aggregates (<20 nm) were con-sistent with their frictional ones very well, namely, low friction occurred on tiny C60 aggregates compared with fatty chains LB monolayer, and 'Micro-rolling effect' was apparent; but for big large ones frictional forces were relatively high and 'ratchet mechanism' was seen apparently. Macro-tribological data proved large C60 aggregates had wear resistance and load-carrying capacities and anti-wear lives for com- posite C60-LB films were prolonged greatly with dis-persibility of C60 improved and its grain diameter re-duced. Tiny C60 aggregates were mainly the lubricating agents. Friction coefficients of composite C60-LB films gradually reduced with loads increasing having the same friction coefficient-load relations with boundary lubrication films.

  2. Tribology of nitrided-coated steel-a review

    Directory of Open Access Journals (Sweden)

    Bhaskar Santosh V.

    2017-01-01

    Full Text Available Surface engineering such as surface treatment, coating, and surface modification are employed to increase surface hardness, minimize adhesion, and hence, to reduce friction and improve resistance to wear. To have optimal tribological performance of Physical Vapor Deposition (PVD hard coating to the substrate materials, pretreatment of the substrate materials is always advisable to avoid plastic deformation of the substrate, which may result in eventual coating failure. The surface treatment results in hardening of the substrate and increase in load support effect. Many approaches aim to improve the adhesion of the coatings onto the substrate and nitriding is the one of the best suitable options for the same. In addition to tribological properties, nitriding leads to improved corrosion resistance. Often corrosion resistance is better than that obtainable with other surface engineering processes such as hard-chrome and nickel plating. Ability of this layer to withstand thermal stresses gives stability which extends the surface life of tools and other components exposed to heat. Most importantly, the nitrogen picked-up by the diffusion layer increases the rotating-bending fatigue strength in components. The present article reviews mainly the tribological advancement of different nitrided-coated steels based on the types of coatings, structure, and the tribo-testing parameters, in recent years.

  3. Effect of Argon Plasma Treatment on Tribological Properties of UHMWPE/MWCNT Nanocomposites

    Directory of Open Access Journals (Sweden)

    Nitturi Naresh Kumar

    2016-08-01

    Full Text Available Ultra-high molecular weight polyethylene (UHMWPE is widely used in artificial joints in the replacement of knee, hip and shoulder that has been impaired as a result of arthritis or other degenerative joint diseases. The UHMWPE made plastic cup is placed in the joint socket in contact with a metal or ceramic ball affixed to a metal stem. Effective reinforcement of multi-walled carbon nanotubes (MWCNTs in UHMWPE results in improved mechanical and tribological properties. The hydrophobic nature of the nanocomposites surface results in lesser contact with biological fluids during the physiological interaction. In this project, we investigate the UHMWPE/MWCNTs nanocomposites reinforced with MWCNTs at different concentrations. The samples were treated with cold argon plasma at different exposure times. The water contact angles for 60 min plasma-treated nanocomposites with 0.0, 0.5, 1.0, 1.5, and 2.0 wt % MWCNTs were found to be 55.65°, 52.51°, 48.01°, 43.72°, and 37.18° respectively. Increasing the treatment time of nanocomposites has shown transformation from a hydrophobic to a hydrophilic nature due to carboxyl groups being bonded on the surface for treated nanocomposites. Wear analysis was performed under dry, and also under biological lubrication, conditions of all treated samples. The wear factor of untreated pure UHMWPE sample was reduced by 68% and 80%, under dry and lubricated conditions, respectively, as compared to 2 wt % 60 min-treated sample. The kinetic friction co-efficient was also noted under both conditions. The hardness of nanocomposites increased with both MWCNTs loading and plasma treatment time. Similarly, the surface roughness of the nanocomposites was reduced.

  4. Application of oral tissue in tribological measurements in an emulsion perception context

    NARCIS (Netherlands)

    Dresselhuis, D.M.; Hoog, de E.H.A.; Cohen Stuart, M.A.; Aken, van G.A.

    2008-01-01

    Tribological measurements are indicated to be a tool in predicting the creamy in-mouth sensation of a food product. Tribological measurements relating lubricational behaviour of a food product to perception are often conducted with artificial surfaces. In this work we used pig's tongue to mimic the

  5. Development and verification of a reciprocating test rig designed for investigation of piston ring tribology

    DEFF Research Database (Denmark)

    Pedersen, Michael Torben; Imran, Tajammal; Klit, Peder

    2009-01-01

    This paper describes the development and verification of a reciprocating test rig, which was designed to study the piston ring tribology. A crank mechanism is used to generate a reciprocating motion for a moving plate, which acts as the liner. A stationary block acting as the ring package is loaded......, which is suitable for the study of piston ring tribology....

  6. Assessment of Patient Safety for Quality Improvement Based on Joint Commission International Accreditation Standards in Farabi Eye Hospital of Tehran University of Medical Sciences

    Directory of Open Access Journals (Sweden)

    Seyed Mohammad Hadi Musavi

    2016-04-01

    Full Text Available Introduction: Quality improvement and patient safety are the most important aspects of health care delivery systems. Improving quality and safety in health care organizations is assured through accreditation. To evaluate patient safety in Farabi Eye Hospital by Joint Commission International (JCI accreditation standards for quality improvement. Materials and Methods:This descriptive-analytical study was carried out in 2014. The data collection instrument was the translated version of JCI checklist, the validity of which was confirmed by a panel of Iranian experts. The data were obtained through interviews with all heads of departments (n=80 and observation of documentation in each department by appraisers in Farabi Hospital. To analyze the data, Spearman's rank correlation coefficient and Mann-Whitney U tests were run using SPSS Version 16. Results: The highest rate of compliance with JCI standards was 91.1%, pertaining to infection control and adopting an approach to reduce contamination. The lowest rate was associated with management monitoring of patients’ demographic information. In general, Farabi Eye Hospital observed the standards to a high level. Conclusion: Our findings exhibited that Farabi Eye Hospital is relatively efficient as to patient safety as a quality improvement factor. However, there were some shortcomings regarding some standards, which indicate deficient compliance with the JCI standards in this hospital. Absence of comprehensive training programs and defective policies and documentation are the key factors for patient safety quality improvement.

  7. Report for fiscal 1998 on the international joint research project of medical welfare equipment; Iryo fukushi kiki kokusai kyodo kenkyu jigyo 1998 nendo chosa hokokusho

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-03-01

    In connection with the international joint research project of medical welfare, a report was made on the results of the investigation conducted in 1998 concerning the technology of overseas medical welfare equipment. In the investigation of china, observation was made on the actual state of the representative medial institutions, with opinions exchanged. Obsolete equipment and old technology are the present state in China, which is strongly desirous of exchanging information with Japan. In Taiwan, being full of venture spirit, an ultrasonic thermal treatment apparatus and an ultrasonic echo device have been produced for example. In Europe, an observation tour was conducted on a German manipulator and process robot while an investigative visit and exchange of opinions were made on the living environment and facilities in Italian training center for physically handicapped persons. Japan's self-supporting and assisting system for excretion attracted many questions and comments. In the investigation in the U.S., views were exchanged concerning '{sup 13}C-MRS device for non-invasion brain metabolic measurement' in research institutions such as universities. A machine developed in Japan received a high evaluation in that {sup 13}C spectrum was obtained from a substantial depth. (NEDO)

  8. Report on a feasibility study of making an international joint research on energy in the Asia region; Asia chiiki kokusai kyodo kenkyu kanosei chosa hokokusho. 2

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-03-01

    A survey was conducted on the energy situation in Thailand, Indonesia, Malaysia, the Philippines and India, and a possibility of making an international joint research. Thailand has sharply increased investments from Europe and the U.S. since 1985, and has been making a rapid industrialization. As to the energy policy, it is important to secure the stable supply and stabilize the price. Indonesia has been rapidly increasing energy consumption in accordance with the recent economic growth, and is fear of becoming a net oil importing country in the near future. They are taking a policy for securing as much domestic oil and gas as possible. Malaysia has been keeping a high growth of over 8% per year for the past 8 years and rapidly increased energy demand. It is expected that they will maintain a high level of the development of energy resources. In the Philippines, the industrial energy is mostly coal, but electricity expected in future is from the oil-fueled power generation. The stable import of oil is a problem. 45 figs., 51 tabs.

  9. Tribological Limitations in Gas Turbine Engines: A Workshop to Identify the Challenges and Set Future Directions

    Science.gov (United States)

    DellaCorte, Chris; Pinkus, Oscar

    2000-01-01

    The following report represents a compendium of selected speaker presentation materials and observations made by Prof O. Pinkus at the NASA/ASME/Industry sponsored workshop entitled "Tribological Limitations in Gas Turbine Engines" held on September 15-17, 1999 in Albany, New York. The impetus for the workshop came from the ASME's Research Committee on Tribology whose goal is to explore new tribological research topics which may become future research opportunities. Since this subject is of current interest to other industrial and government entities the conference received cosponsorship as noted above. The conference was well attended by government, industrial and academic participants. Topics discussed included current tribological issues in gas turbines as well as the potential impact (drawbacks and advantages) of future tribological technologies especially foil air bearings and magnetic beatings. It is hoped that this workshop report may serve as a starting point for continued discussions and activities in oil-free turbomachinery systems.

  10. 12 CFR 347.107 - Joint ventures.

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 4 2010-01-01 2010-01-01 false Joint ventures. 347.107 Section 347.107 Banks... INTERNATIONAL BANKING § 347.107 Joint ventures. (a) Joint ventures. If a bank, directly or indirectly, acquires or holds an equity interest in a foreign organization that is a joint venture, and the bank or...

  11. Effect of clearance on cartilage tribology in hip hemi-arthroplasty.

    Science.gov (United States)

    Lizhang, Jia; Taylor, Simon D; Jin, Zhongmin; Fisher, John; Williams, Sophie

    2013-12-01

    Hemi-arthroplasty of the hip (an artificial femoral head articulating against the natural acetabulum) is used to treat fractured necks of femur; however, there is evidence that articulation causes erosion of the cartilage, resulting in pain for the patient. Parameters that may influence this cartilage erosion include head material and roughness, clearance between the head and acetabulum and activity levels of the patient. This study has assessed the effect of clearance of hemi-arthroplasty articulations on the contact stress, friction and cartilage deformation in an in vitro tribological simulation of the hemi-arthroplasty joint that applied dynamic loads and motion. It has been demonstrated that peak contact stress increased from 5.6 to 10.6 MPa as radial clearance increased from small (1.8 mm). In all samples, friction factor increased with time and was significantly less with extra-large clearances compared to small (<0.6 mm), medium (0.6-1.2 mm) and large (1.2-1.8 mm) clearances. The cartilage deformation observed was significantly greater in acetabulum samples paired to give small or extra-large clearances compared to those with medium or large clearances.

  12. Sliding friction of nanocomposite WC1-x/C coatings: transfer film and its influence on tribology.

    Science.gov (United States)

    Liu, Y; Gubisch, M; Spiess, L; Schaefer, J A

    2009-06-01

    The transfer film on steel spheres formed in reciprocating sliding against nanocomposite coatings based on nanocrystalline WC1-x in amorphous carbon matrix is characterized and correlated with the tribological properties measured by a precision microtribometer. With the presence of transfer film, a coefficient of friction approximately 0.13 and a depth wear rate approximately 0.35 x 10(-10) m/N.Pass were obtained. The central zone of the transfer film covering approximately 25% of the Hertz contact area is intact while cracks and wear debris are found in the vast peripheral area. It is also heavily oxidized due to the absence of carbon, which is located at the peripherals and acts as lubricants. We propose that the oxidation of WC and adhesion of the oxides to the surface of sphere is the main mechanism for the buildup of the transfer films. With the thickening of the film, the internal stress increases. Under the shear stress, spalling and cracking of the transfer film take place. The overall tribological performance of the coatings is therefore a competing process of buildup and spalling of transfer films.

  13. Assessing uncertainties in the Noah-MP ensemble simulations of a cropland site during the Tibet Joint International Cooperation program field campaign

    Science.gov (United States)

    Zhang, Guo; Chen, Fei; Gan, Yanjun

    2016-08-01

    Despite the widespread use of the latest community Noah with multiparameterization (Noah-MP) land surface model, it has not been rigorously evaluated over the complex Tibetan Plateau. This study assessed uncertainties in Noah-MP simulations of a cropland site using observations from the 2008 Joint International Cooperation program field campaign. Such an assessment was conducted in the context of performing a total number of 4608 Noah-MP physics ensemble simulations using two analysis methods: the natural selection approach and Tukey's test, where the impacts of uncertainties in atmospheric forcing conditions, vegetation parameters, and subprocesses on model simulations were identified. Uncertainty in precipitation data exerts greater influence on the general behavior of Noah-MP ensemble simulations than that in the leaf area index (LAI). However, using a more realistic seasonal LAI improves the seasonal variations of surface heat fluxes. Combining a better precipitation forcing data set and Moderate Resolution Imaging Spectroradiometer monthly LAI significantly reduces the uncertainty range of the ensemble mean of surface heat fluxes. The uncertainty analysis results using the natural selection method are largely similar to that from Tukey's test but show some subtle differences. Both methods reveal greater uncertainties in the following subprocess schemes: canopy resistance, soil moisture threshold for evaporation, runoff and groundwater, and surface-layer parameterization for this cropland site. The uncertainty analysis identifies the parameterization schemes that demonstrably degrade model performance. The uncertainties in ensemble simulations were significantly reduced when those schemes were excluded, and it was possible to configure an optimal combination of parameterization schemes to obtain similar performance to the ensemble mean of the "best" ensemble experiment.

  14. Mechanical and tribological properties of ion beam-processed surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Kodali, Padma [Univ. of Maryland, College Park, MD (United States)

    1998-01-01

    The intent of this work was to broaden the applications of well-established surface modification techniques and to elucidate the various wear mechanisms that occur in sliding contact of ion-beam processed surfaces. The investigation included characterization and evaluation of coatings and modified surfaces synthesized by three surface engineering methods; namely, beam-line ion implantation, plasma-source ion implantation, and DC magnetron sputtering. Correlation among measured properties such as surface hardness, fracture toughness, and wear behavior was also examined. This dissertation focused on the following areas of research: (1) investigating the mechanical and tribological properties of mixed implantation of carbon and nitrogen into single crystal silicon by beam-line implantation; (2) characterizing the mechanical and tribological properties of diamond-like carbon (DLC) coatings processed by plasma source ion implantation; and (3) developing and evaluating metastable boron-carbon-nitrogen (BCN) compound coatings for mechanical and tribological properties. The surface hardness of a mixed carbon-nitrogen implant sample improved significantly compared to the unimplanted sample. However, the enhancement in the wear factor of this sample was found to be less significant than carbon-implanted samples. The presence of nitrogen might be responsible for the degraded wear behavior since nitrogen-implantation alone resulted in no improvement in the wear factor. DLC coatings have low friction, low wear factor, and high hardness. The fracture toughness of DLC coatings has been estimated for the first time. The wear mechanism in DLC coatings investigated with a ruby slider under a contact stress of 1 GPa was determined to be plastic deformation. The preliminary data on metastable BCN compound coatings indicated high friction, low wear factor, and high hardness.

  15. Tribological Characteristics of Chromium-active Carbon Electroplated Composite Coatings

    Institute of Scientific and Technical Information of China (English)

    GUKa-fi; HUAMeng; Yi-min

    2004-01-01

    A process of chromium electroplating using a standard bath with additives and active carbon particles was reported, and the tribological behaviors of the composite coatings using the pin-on-disk tester and the table wear tester were i nvestig(aed. Experimental results indicate that the electroplated chromium-active carbon composite coatings exhibited the low friction coefficient anti excellent anti-wear properties whets coffered with the normal chromium electroplated ones. The formation of active carbon particles within the chromium matrices can be explained by SEM analysis and the mechanis of wear resistance of the composite coatings were studied.

  16. Tribological effects of particle concentration of an iron particle suspension

    Institute of Scientific and Technical Information of China (English)

    W.C.Leung; P.L.Wong; C.Feng; W.A.Bullough

    2001-01-01

    The general friction and wear performance of an iron particulate suspension underboundary lubrication conditions are presented. The suspension is a mixture of 1-5 micrometerdiameter carbonyl iron particles with commercial hydraulic oil, which resembles typical compositionof magneto-rheological fluids. The investigation involves changing the particle concentration of thesuspension. The optimal concentration of the suspension from a tribological view point can be ob-served from the experimental results,which provides a reference to the design of the particle load-ing of magneto-rheological fluids.

  17. Fabrication and tribological properties of Al reinforced with carbon fibres

    Energy Technology Data Exchange (ETDEWEB)

    Estrems Amestoy, M.; Faura Mateu, F. [Universidad Politecnica de Cartagena (Spain); Froyen, L. [Department of Metallurgy and Materials Engineering. Katholieke Universiteit Lewen. Heverlee. Belgium (Belgium)

    2000-07-01

    The present work studies the manufacturing process of Al reinforced with Carbon Fibres (CF) by Squeeze Casting, establishing the variables for obtaining and acceptable product with little Al{sub 4}C{sub 3} at the interface. Friction and wear tests are performed and the necessary conditions for the formation of a tribofilm are established. The tests how an increasing resistance to abrasion due to their own wear mechanism. Certain design criteria for those components subjected to friction are recommended in order to maximize the mechanical performance of the tribological system. (Author ) 16 refs.

  18. Tribological and mechanical performance evaluation of metal prosthesis components manufactured via metal injection molding.

    Science.gov (United States)

    Melli, Virginia; Juszczyk, Mateusz; Sandrini, Enrico; Bolelli, Giovanni; Bonferroni, Benedetta; Lusvarghi, Luca; Cigada, Alberto; Manfredini, Tiziano; De Nardo, Luigi

    2015-01-01

    The increasing number of total joint replacements, in particular for the knee joint, has a growing impact on the healthcare system costs. New cost-saving manufacturing technologies are being explored nowadays. Metal injection molding (MIM) has already demonstrated its suitability for the production of CoCrMo alloy tibial trays, with a significant reduction in production costs, by holding both corrosion resistance and biocompatibility. In this work, mechanical and tribological properties were evaluated on tibial trays obtained via MIM and conventional investment casting. Surface hardness and wear properties were evaluated through Vickers hardness, scratch and pin on disk tests. The MIM and cast finished tibial trays were then subjected to a fatigue test campaign in order to obtain their fatigue load limit at 5 millions cycles following ISO 14879-1 directions. CoCrMo cast alloy exhibited 514 HV hardness compared to 335 HV of MIM alloy, furthermore it developed narrower scratches with a higher tendency towards microploughing than microcutting, in comparison to MIM CoCrMo. The observed fatigue limits were (1,766 ± 52) N for cast tibial trays and (1,625 ± 44) N for MIM ones. Fracture morphologies pointed out to a more brittle behavior of MIM microstructure. These aspects were attributed to the absence of a fine toughening and surface hardening carbide dispersion in MIM grains. Nevertheless, MIM tibial trays exhibited a fatigue limit far beyond the 900 N of maximum load prescribed by ISO and ASTM standards for the clinical application of these devices.

  19. Study on Tribological Properties of Irradiated Crosslinking UHMWPE Nano-Composite

    Institute of Scientific and Technical Information of China (English)

    Lei Xiong; Dang-sheng Xiong; Jia-bo Jin

    2009-01-01

    Ultra High Molecular Weight Polyethylene (UHMWPE) has been widely used as a bearing material for artificial joint replacement over forty years. It is usually crosslinked by gamma rays irradiation before its implantation into human body. In this study, UHMWPE and UHMWPE/nano-hydroxyapatite (n-HA) composite were prepared by vacuum hot-pressing method. The prepared materials were irradiated by gamma rays in vacuum and molten heat treated in vacuum just after irradiation. The effect of filling n-HA with gamma irradiation on tribological properties of UHMWPE was investigated by using friction and wear experimental machine (model MM-200) under deionized water lubrication. Micro-morphology of wom surface was observed by metallographic microscope. Contact angle and hardness of the materials were also measured. The results show that contact angle and hardness are changed by filling n-HA and gamma irradiation. Friction coefficient and wear rate under deionized water lubrication are reduced by filling n-HA. While friction coefficient is increased and wear rate is reduced significantly by gamma irradiation. The worn surface of unfilled material is mainly characterized as adhesive wear and abrasive wear, and that of n-HA filled material is mainly characterized as abrasive wear. After gamma irradiation, the degrees of adhesive and abrasive wear for unfilled material and abrasive wear of n-HA filled material are significantly reduced. Unfilled and filled materials after irradiation are mainly shown as slight fatigue wear. The results indicate that UHMWPE and UHMWPE/n-HA irradiated at the dose of 150 kGy can be used as bearing materials in artificial joints for its excellent wear resistance compared to original UHMWPE.

  20. Joint ventures

    DEFF Research Database (Denmark)

    Sørensen, Karsten Engsig

    Afhandlingen analysere de konkurrenceretlige og selskabsretlige regler som er bestemmende for hvordan et joint venture samarbejde er struktureret......Afhandlingen analysere de konkurrenceretlige og selskabsretlige regler som er bestemmende for hvordan et joint venture samarbejde er struktureret...

  1. Joint swelling

    Science.gov (United States)

    ... chap 275. Raftery AT, Lim E, Ostor AJK. Joint disorders. In: Raftery AT, Lim E, Ostor AJK, eds. ... A.M. Editorial team. Related MedlinePlus Health Topics Joint Disorders Browse the Encyclopedia A.D.A.M., Inc. ...

  2. Joint ventures

    NARCIS (Netherlands)

    M.N. Hoogendoorn (Martin)

    2009-01-01

    textabstractEen veel voorkomende wijze van samenwerking tussen ondernemingen is het uitvoeren van activiteiten in de vorm van een joint venture. Een joint venture is bijna altijd een afzonderlijke juridische entiteit. De partners in de joint venture voeren gezamenlijk de zeggenschap uit. In internat

  3. Joint ventures

    NARCIS (Netherlands)

    M.N. Hoogendoorn (Martin)

    2009-01-01

    textabstractEen veel voorkomende wijze van samenwerking tussen ondernemingen is het uitvoeren van activiteiten in de vorm van een joint venture. Een joint venture is bijna altijd een afzonderlijke juridische entiteit. De partners in de joint venture voeren gezamenlijk de zeggenschap uit. In internat

  4. Superior tribological properties of an amorphous carbon film with a graphite-like structure

    Institute of Scientific and Technical Information of China (English)

    Wang Yong-Jun; Li Hong-Xuan; Ji Li; Liu Xiao-Hong; Wu Yan-Xia; Zhou Hui-Di; Chen Jian-Min

    2012-01-01

    Amorphous carbon films with high sp2 concentrations are deposited by unbalanced magnetron sputtering with a narrow range of substrate bias voltage. Field emission scanning electron microscopes (FESEMs),high resolution transmission electron microscopes (HRTEMs),atomic force microscopes (AFMs),the Raman spectrometers,nanoindentation,and tribometers are subsequently used to characterize the microstructures and the properties of the resulting films.It is found that the present films are dominated by the sp2 sites.However,the films demonstrate a moderate hardness together with a low internal stress.The high hardness of the deposited film originates from the crosslinking of the sp2 clusters by the sp3 sites.The presence of the graphite-like clusters in the film structure may be responsible for the low internal stress.What is more important is that the resulting films show excellent tribological properties with high load capacity and excellent wear resistance in humid atmospheres.The relationship between the microstructure determined by the deposition condition and the film characteristic is discussed in detail.

  5. Tribological Properties of DLC Film Prepared by C + Ion Beam-assisted Deposition (IBAD)

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    C + ion beam-assisted deposition was utilized to prepare deposit diamond-like carbon (DLC) film.With the help of a series of experiments such as Raman spectroscopy, FT- IR spectroscopy, AFM and nanoindentation, the DLC film has been recognized as hydrogenated DLC film and its tribological properties have been evaluated.The ball-on-disc testing results show that the hardness and the tribological properties of the DLC film produced by C + ion beam-assisted deposition are improved significandy.DLC film produced by C+ ion beam-assisted deposition is positive to have a prosperous tribological application in the near future.

  6. Tribological properties of epoxy composite materials for marine and river transport

    Science.gov (United States)

    Buketov, A. V.; Maruschak, P. O.; Brailo, N. V.; Akimov, A. V.; Kobelnik, O. S.; Panin, S. V.

    2016-11-01

    Tribological properties of epoxy composites filled with thermoplastics and dispersed particles under sea water environment were analyzed. It has been revealed that the composition, sliding friction conditions, as well as the marine environment, substantially affect the tribological properties of the materials. The improvement of tribological properties of epoxycomposite thermosetting plastics after their filling with thermoplastic polyamide PA-6 granules under friction in sea water environment has been proved. The recommendations on applying the developed material in friction parts for marine and river transport were formulated.

  7. A Review on Tribological Behaviour of Polymeric Composites and Future Reinforcements

    Directory of Open Access Journals (Sweden)

    B. Aldousiri

    2013-01-01

    Full Text Available Many different families of polymers are used in industries and engineering applications. The demands for studying the tribological behaviour of polymers and their composites are recently increased. This article briefs the most recent studies on the tribological behaviour of polymeric materials based on synthetic fibres. It reviews several factors which control the wear and frictional characteristics of such materials, that is, additives, fibres, interfacial adhesion, tribology environment, operating parameters, and composite geometry. In addition to that, new bioreinforcement (fibre is introduced associated with preliminary results. The results showed that there is high potential of replacing the conventional reinforcement with the bioones.

  8. Experimental Analysis on Tribological Behavior of Nano Based Bio-Lubricants using Four Ball Tribometer

    Directory of Open Access Journals (Sweden)

    S. Baskar

    2015-12-01

    Full Text Available The present work describes the tribological behavior of CuO, WS2 and TiO2 nano particles as an antiwear additive to a chemically modified rapeseed oil (CMRO. The tribological tests were run on a four ball tribometer. The variation of viscosity of various nano based biolubricants with respect to temperature is also estimated in accordance with ASTM D 445. The test results were compared with petroleum based synthetic lubricant (SAE20W40. The test results exhibited that CMRO with nano CuO has better tribological characteristics, smoother wear scar and higher viscosity compared to synthetic lubricant and other nano based biolubricants.

  9. Joint venture instability: a life cycle approach

    OpenAIRE

    Roy Chowdhury, Prabal; Roy Chowdhury, Indrani

    2001-01-01

    Joint ventures represent one of the most fascinating developments in international business. In the last few decades, the rate of joint venture formation has accelerated dramatically. Nowadays joint ventures are much more widespread and occur in industries like telecommunications, biotechnology etc. At the same time, however, it must be noted that joint ventures are very unstable. In this paper we survey the phenomenon of joint venture instability. We draw on the relative recent theoretical l...

  10. Joint venture instability: a life cycle approach

    OpenAIRE

    Roy Chowdhury, Prabal; Roy Chowdhury, Indrani

    2001-01-01

    Joint ventures represent one of the most fascinating developments in international business. In the last few decades, the rate of joint venture formation has accelerated dramatically. Nowadays joint ventures are much more widespread and occur in industries like telecommunications, biotechnology etc. At the same time, however, it must be noted that joint ventures are very unstable. In this paper we survey the phenomenon of joint venture instability. We draw on the relative recent theoretical l...

  11. Critical Values of Facet Joint Angulation and Tropism in the Development of Lumbar Degenerative Spondylolisthesis: An International, Large-Scale Multicenter Study by the AOSpine Asia Pacific Research Collaboration Consortium

    Science.gov (United States)

    Samartzis, Dino; Cheung, Jason Pui Yin; Rajasekaran, Shanmuganathan; Kawaguchi, Yoshiharu; Acharya, Shankar; Kawakami, Mamoru; Satoh, Shigenobu; Chen, Wen-Jer; Park, Chun-Kun; Lee, Chong-Suh; Foocharoen, Thanit; Nagashima, Hideki; Kuh, Sunguk; Zheng, Zhaomin; Condor, Richard; Ito, Manabu; Iwasaki, Motoki; Jeong, Je Hoon; Luk, Keith D. K.; Prijambodo, Bambang; Rege, Amol; Jahng, Tae-Ahn; Luo, Zhuojing; Tassanawipas, Warat; Acharya, Narayana; Pokharel, Rohit; Shen, Yong; Ito, Takui; Zhang, Zhihai; Aithala P, Janardhana; Kumar, Gomatam Vijay; Jabir, Rahyussalim Ahmad; Basu, Saumyajit; Li, Baojun; Moudgil, Vishal; Goss, Ben; Sham, Phoebe; Williams, Richard

    2015-01-01

    Study Design  An international, multicenter cross-sectional image-based study performed in 33 institutions in the Asia Pacific region. Objective  The study addressed the role of facet joint angulation and tropism in relation to L4–L5 degenerative spondylolisthesis (DS). Methods  The study included 349 patients (63% females; mean age: 61.8 years) with single-level DS; 82 had no L4–L5 DS (group A) and 267 had L4–L5 DS (group B). Axial computed tomography and magnetic resonance imaging were utilized to assess facet joint angulations and tropism (i.e., asymmetry between facet joint angulations) between groups. Results  There was a statistically significant difference between group A (left mean: 46.1 degrees; right mean: 48.2 degrees) and group B (left mean: 55.4 degrees; right mean: 57.5 degrees) in relation to bilateral L4–L5 facet joint angulations (p < 0.001). The mean bilateral angulation difference was 7.4 and 9.6 degrees in groups A and B, respectively (p = 0.025). A critical value of 58 degrees or greater significantly increased the likelihood of DS if unilateral (adjusted OR: 2.5; 95% CI: 1.2 to 5.5; p = 0.021) or bilateral facets (adjusted OR: 5.9; 95% CI: 2.7 to 13.2; p < 0.001) were involved. Facet joint tropism was found to be relevant between 16 and 24 degrees angulation difference (adjusted OR: 5.6; 95% CI: 1.2 to 26.1; p = 0.027). Conclusions  In one of the largest studies assessing facet joint orientation in patients with DS, greater sagittal facet joint angulation was associated with L4-L5 DS, with a critical value of 58 degrees or greater increasing the likelihood of the condition for unilateral and bilateral facet joint involvement. Specific facet joint tropism categories were noted to be associated with DS. PMID:27433424

  12. Mesostructured Hydrophobic-Oleophobic Silica Films for Sustained Functionality in Tribological Environments

    Science.gov (United States)

    Kessman, Aaron J.

    , chemical, mechanical, surface, and tribological properties were investigated to examine the performance of functionalized mesostructured thin films in abrasive environments. Analytical techniques included XPS depth profiling, porosimetry, AFM and friction force microscopy, nanoindentation, contact angle goniometry, and stylus profilometry. Controlled abrasion was conducted using a lab-built instrument. Hydrophobic and oleophobic properties were monitored ex-situ during abrasion to observe and quantify changes in functionality as the material is worn. Experimental results show that surfactant templating aids in generating an internal mesostructure that facilitates encapsulation of functional moieties. This encapsulation allows exposed surfaces to be sacrificially worn away while maintaining much of the original functionality. The results of tribological measurements, as observed through abrasive wear testing, friction force mapping, and wear rate calculations, suggest that the low-friction surface generate by fluorosilane moieties grafted to internal pore surfaces mitigates to some extent the detrimental effect of film porosity on hardness and wear resistance.

  13. Tribological properties of sputtered tungsten and tungsten nitride thin films

    Institute of Scientific and Technical Information of China (English)

    Wong; K.M.; ShenY.G.; Wong; P.L.

    2001-01-01

    The surface roughness, hardness and tribological properties of tungsten (W) and tung-sten nitride (WNx) thin films prepared by dc magnetron sputtering and reactive magnetron sputter-ing in Ar-N2 gas mixtures have been studied using atomic force microscopy (AFM), nanoindenta-tion measurements and ball-on-disc wear testing. A pronounced surface roughness was observedonly for films under compressive strains. The surface was flat under tension but rough under com-pression. Similar hardness with value about 20 GPa were observed in the W and WNx (x=0.3)films. This is thought to be due to the fact the grains are restricted to a very small size in the coat-ings. The higher coefficients of friction (0.4 for W and 0.9 for WN0.3) suggest that WN0.3 is not theoptimum phase. Finally, discussions are made with tribological test results.

  14. Tribological behaviour of graphite powders at nano- and macroscopic scales

    Science.gov (United States)

    Schmitt, M.; Bistac, S.; Jradi, K.

    2007-04-01

    With its high resistance, good hardness and electrical conductibility in the basal plans, graphite is used for many years in various tribological fields such as seals, bearings or electrical motor brushes, and also for applications needing excellent lubrication and wearreducing properties. But thanks to its low density, graphite is at the moment destined for technologies which need a reducing of the weight combined with an enhancement of the efficiency, as it is the case in aeronautical industry. In this contexte, the friction and wear of natural (named graphite A) and synthetic (called graphites B and C) powders were evaluated, first at the macroscopic scale when sliding against steel counterfaces, under various applied normal loads. Scanning Electron Microscopy and AFM in tapping mode were used to observe the morphological modifications of the graphites. It is noticed that an enlargement of the applied normal load leads to an increase of the friction coefficient for graphites A and C; but for the graphite B, it seems that a ''limit'' load can induce a complete change of the tribological behaviour. At the same time, the nano-friction properties of these powders were evaluated by AFM measurements in contact mode, at different contact loads. As it was the case at the macroscopic scale, an increase of the nano-contact load induces higher friction coefficients. The determining of the friction and wear mechanisms of the graphite powders, as a function of both their intrinsic characteristics and the applied normal load, is then possible.

  15. Effects of concentration and temperature on tribological properties of biodiesel

    Directory of Open Access Journals (Sweden)

    De-Xing Peng

    2015-11-01

    Full Text Available For tribologists, continuing challenges in engine design include reduced emissions and increased operating temperatures. Regulating the sulfur content in diesel fuel is expected to reduce the lubricity of these fuels, which may result in increased wear and damage of fuel injection systems in diesel engines. However, the use of biodiesel improves lubricity and cetane number requirements, particularly in ultra-low sulfur petro-diesel. In this study, the effect of temperature on the tribological properties of palm biodiesel was investigated using a wear machine. Palm biodiesel was used as a lubricating additive to petro-diesel at six concentrations of 2%, 5%, 10%, 20%, 50%, and 100%, and these biodiesel blends were named as B2, B5, B10, B20, B50, and B100, respectively. The tribological experiments were performed using the ball-on-ring method. Tests were conducted at 30°C, 60°C, 90°C, and 120°C, under a normal load of 50 N for 2 h and at a speed of 500 r/min. The wear scar diameter and the worn surface of tribopairs were studied and analyzed. According to the wear experimental results, the addition of a small amount of palm biodiesel to petroleum diesel can bring about a considerable reduction in the wear and friction under boundary lubrication. Results show that friction and wear increase with increasing temperature.

  16. Tribological performance of organic cadmium compound as lubricant additive

    Institute of Scientific and Technical Information of China (English)

    HU Jian-qiang; XIE Feng; ZHU Huan-qin; ZHEN Fa-zheng; YAO Jun-bing

    2004-01-01

    The oil-soluble cadmium dipropyldithiophosphate additive was synthesized. A four-ball tester was used to evaluate the tribological performance of the additive in a mineral oil under different loads and lubricant grease synthesized compared with some commercial additives. The results show that it exhibits excellent antiwear and load-carrying capacities and is better than other additives. The surface analytical tools such as scanning electron microscope (SEM) with energy dispersive X-ray (EDX), X-ray photoelectron spectrometer (XPS) were used to investigate the topography, the compositions, and chemical states of some typical elements on the rubbing surface of worn scar.Smooth and light topography of worn scar further confirms that the additive shows good antiwear capacities. The results of EDX and XPS analyses indicate that tribochemical mixed protective films consisting of atomic cadmium, sulphides, sulphates and phosphates are formed on the rubbing surface, which contribute to improving the tribological properties of lubricant and grease. Particularly, the soft cadmium film formed plays an important role in improving antiwear properties of oils. Finally, antiwear mechanism of the additive and formation scheme of atomic cadmium was proposed.

  17. Sputtering as a Technique for Applying Tribological Coatings

    Science.gov (United States)

    Ramalingam, S.

    1984-01-01

    Friction and wear-induced mechanical failures may be controlled to extend the life of tribological components through the interposition of selected solid materials between contacting surfaces. Thin solid films of soft and hard materials are appropriate to lower friction and enhance the wear resistance of precision tribo-elements. Tribological characteristics of thin hard coats deposited on a variety of ferrous and non-ferrous substrates were tested. The thin hard coats used were titanium nitride films deposited by reactive magnetron sputtering of metallic titanium. High contact stress, low speed tests showed wear rate reductions of one or more magnitude, even with films a few micrometers in thickness. Low contact stress, high speed tests carried out under rather severe test conditions showed that thin films of TiN afforded significant friction reduction and wear protection. Thin hard coats were shown to improve the friction and wear performance of rolling contacts. Satisfactory film-to-substrate adhesion strengths can be obtained with reactive magnetron sputtering. X-ray diffraction and microhardness tests were employed to assess the effectiveness of the sputtering technique.

  18. Scaling Effects on Materials Tribology: From Macro to Micro Scale

    Science.gov (United States)

    Stoyanov, Pantcho; Chromik, Richard R.

    2017-01-01

    The tribological study of materials inherently involves the interaction of surface asperities at the micro to nanoscopic length scales. This is the case for large scale engineering applications with sliding contacts, where the real area of contact is made up of small contacting asperities that make up only a fraction of the apparent area of contact. This is why researchers have sought to create idealized experiments of single asperity contacts in the field of nanotribology. At the same time, small scale engineering structures known as micro- and nano-electromechanical systems (MEMS and NEMS) have been developed, where the apparent area of contact approaches the length scale of the asperities, meaning the real area of contact for these devices may be only a few asperities. This is essentially the field of microtribology, where the contact size and/or forces involved have pushed the nature of the interaction between two surfaces towards the regime where the scale of the interaction approaches that of the natural length scale of the features on the surface. This paper provides a review of microtribology with the purpose to understand how tribological processes are different at the smaller length scales compared to macrotribology. Studies of the interfacial phenomena at the macroscopic length scales (e.g., using in situ tribometry) will be discussed and correlated with new findings and methodologies at the micro-length scale. PMID:28772909

  19. Tribological properties of nanosized calcium carbonate filled polyamide 66 nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Itagaki, Kaito [Department of Mechanical Engineering, Graduate School of Engineering, Kogakuin University, 2665-1 Nakano, Hachioji, Tokyo 192-0015 Japan (Japan); Nishitani, Yosuke [Department of Mechanical Engineering, Faculty of Engineering, Kogakuin University, 2665-1 Nakano, Hachioji, Tokyo, 192-0015 Japan (Japan); Kitano, Takeshi [Polymer Centre, Faculty of Technology, Tomas Bata University in Zlin, T.G.M. 275, Zlin, 767 72 Czech Republic (Czech Republic); Eguchi, Kenichiro [Shiraishi Central Laboratories, 4-78 Motohama,Amagasaki,Hyogo,660-0085 Japan (Japan)

    2016-03-09

    For the purpose of developing high performance tribomaterials for mechanical sliding parts such as gears, bearings and so on, nanosized calcium carbonate (nano-CaCO{sub 3}) filled polyamide 66 (PA66) nanocomposites were investigated. The nano-CaCO{sub 3} was a kind of precipitated (colloid typed) CaCO{sub 3}, and its average particle size was 40, 80 and 150 nm. Surface treatment was performed by fatty acid on the nano-CaCO{sub 3} and its volume fraction in the nanocomposite was varied from 1 to 20vol.%. These nanocomposites were melt-mixed by a twin screw extruder and injection-molded. Tribological properties were measured by two types of sliding wear testers such as ring-on-plate type and ball-on-plate type one under dry condition. The counterface, worn surface and wear debris were observed by digital microscope and scanning electron microscope. It was found that the nano-CaCO{sub 3} has a good effect on the tribological properties, although the effect on the frictional coefficient and specific wear rate is differed by the volume fraction and the type of sliding wear modes. This is attributed to the change of wear mechanisms, which is the change of form of the transfer films on the counterface and the size of wear debris. It follows from these results that PA66/nano-CaCO{sub 3} nanocomposites may be possible to be the high performance tribomaterials.

  20. Tribology-Structure Relationships in Silicon Oxycarbide Thin Films

    Energy Technology Data Exchange (ETDEWEB)

    Ryan, Joseph V.; Colombo, Paolo; Howell, Jane A.; Pantano, C. G.

    2010-09-01

    Silicon oxycarbide is a versatile material system that is attractive for many applications because of its ability to tune properties such as chemical compatibility, refractive index, electrical conductivity, and optical band gap through changes in composition. One particularly intriguing application lies in the production of biocompatible coatings with good mechanical properties. In this paper, we report on the wide range of mechanical and tribological property values exhibited by silicon oxycarbide thin films deposited by reactive radio frequency magnetron sputtering. Through a change in oxygen partial pressure in the sputtering plasma, the composition of the films was controlled to produce relatively pure SiO2, carbon-doped SiC, and compositions between these limits. Hardness values were 8-20 GPa over this range and the elastic modulus was measured to be between 60 and 220 GPa. We call attention to the fit of the mechanical data to a simple additive bond-mixture model for property prediction. Tribological parameters were measured using a ball-on-disk apparatus and the samples exhibited the same general trends for friction coefficient and wear rate. One film is shown to produce variable low friction behavior and low wear rate, which suggests a solid-state self-lubrication process because of heterogeneity on the nanometer scale.

  1. Tribological behaviour of unidirectional carbon fibre-reinforced epoxy composites

    Science.gov (United States)

    Şahin, Y.; De Baets, P.

    2017-02-01

    Tribological behaviour of unidirectional carbon fibre-reinforced epoxy composites containing 42wt.% (CU42) and 52wt.% (CU52) carbon fibres fabricated by moulding technique was investigated on a pin-on-flat plate configuration. It is the first time to measure static and dynamic coefficient of frictions and wear rates of epoxy composites under heavy loading conditions. Microstructures of composites were examined by scanning electron microscopy (SEM). The experimental results indicated the carbon fiber improved the tribological properties of thermoset epoxy by reducing wear rate, but increased the coefficient of friction. At higher load, average wear rates were about 10.8x10-5 mm3/N.m for composites while it was about 38.20x10-5 mm3/N.m for epoxy resin. The wear rate decreased with decreasing load while friction coefficient increased with decreasing load. Moreover, friction coefficient of composites of CU42 tested at 90 N load was measured to be in the range 0.35 and 0.13 for static and dynamic component, respectively.

  2. Self-organization at the frictional interface for green tribology.

    Science.gov (United States)

    Nosonovsky, Michael

    2010-10-28

    Despite the fact that self-organization during friction has received relatively little attention from tribologists so far, it has the potential for the creation of self-healing and self-lubricating materials, which are important for green or environment-friendly tribology. The principles of the thermodynamics of irreversible processes and of the nonlinear theory of dynamical systems are used to investigate the formation of spatial and temporal structures during friction. The transition to the self-organized state with low friction and wear occurs through destabilization of steady-state (stationary) sliding. The criterion for destabilization is formulated and several examples are discussed: the formation of a protective film, microtopography evolution and slip waves. The pattern formation may involve self-organized criticality and reaction-diffusion systems. A special self-healing mechanism may be embedded into the material by coupling the corresponding required forces. The analysis provides the structure-property relationship, which can be applied for the design optimization of composite self-lubricating and self-healing materials for various ecologically friendly applications and green tribology.

  3. Ceramic Conversion Treatment of Titanium Aluminide for Improved Tribological Properties

    Institute of Scientific and Technical Information of China (English)

    JingXIA; ChenxiLI; HanshanDONG; TomBELL

    2004-01-01

    Gamma-based titanium aluminides have great potential in the automotive industries (e.g. valves in a car engine), but tribological property could be one of the crucial factors in determining the life and performance of a titanium aluminide part. A surface modification technique, namely ceramic conversion (CC) treatment has been developed to improve the tribological properties of a γ-based titanium aluminide (Ti-48A1-2Nb-2Cr-B), and the surface properties were fully characterised. The results indicate that ceramic conversion treatment can produce an oxide layer consisting of a top TiO2 surface followed by a mixture of TiO2 and Al2O3. Such hardened layer has significantly improved the load-bearing capacity and wear resistance of the intermetallics, as evidenced by an increase of scuffing load up to 4 times and a wear rate reduction of two orders of magnitude. The coefficient of friction has also been reduced from 0.5-0.7 for the untreated to an average of 0.22 for the CC-treated alloy under dry sliding contact conditions.

  4. Ceramic Conversion Treatment of Titanium Aluminide for Improved Tribological Properties

    Institute of Scientific and Technical Information of China (English)

    Jing XIA; Chenxi LI; Hanshan DONG; Tom BELL

    2004-01-01

    Gamma-based titanium aluminides have great potential in the automotive industries (e.g. valves in a car engine),but tribological property could be one of the crucial factors in determining the life and performance of a titanium aluminide part. A surface modification technique, namely ceramic conversion (CC) treatment has been developed to improve the tribological properties of a γ-based titanium aluminide (Ti-48Al-2Nb-2Cr-B), and the surface properties were fully characterised. The results indicate that ceramic conversion treatment can produce an oxide layer consisting of a top TiO2 surface followed by a mixture of TiO2 and Al2O3. Such hardened layer has significantly improved the load-bearing capacity and wear resistance of the intermetallics, as evidenced by an increase of scuffing load up to 4 times and a wear rate reduction of two orders of magnitude. The coefficient of friction has also been reduced from 0.5-0.7 for the untreated to an average of 0.22 for the CC-treated alloy under dry sliding contact conditions.

  5. Safe medication management and use of narcotics in a Joint Commission International-accredited academic medical center hospital in the People's Republic of China.

    Science.gov (United States)

    Fang, Xu; Zhu, Ling-Ling; Pan, Sheng-Dong; Xia, Ping; Chen, Meng; Zhou, Quan

    2016-01-01

    Safe medication management and use of high-alert narcotics should arouse concern. Risk management experiences in this respect in a large-scale Joint Commission International (JCI)-accredited academic medical center hospital in the People's Republic of China during 2011-2015, focusing on organizational, educational, motivational, and information technological measures in storage, prescribing, preparing, dispensing, administration, and monitoring of medication are summarized. The intensity of use of meperidine in hospitalized patients in 2015 was one-fourth that in 2011. A 100% implementation rate of standard storage of narcotics has been achieved in the hospital since December 2012. A "Plan, Do, Check, Act" cycle was efficient because the ratio of number of inappropriate narcotics prescriptions to total number of narcotics prescriptions for inpatients decreased from August 2014 to December 2014 (28.22% versus 2.96%, P=0.0000), and it was controlled below 6% from then on. During the journey to good pain management ward accreditation by the Ministry of Health, People's Republic of China, (April 2012-October 2012), the medical oncology ward successfully demonstrated an increase in the pain screening rate at admission from 43.5% to 100%, cancer pain control rate from 85% to 96%, and degree of satisfaction toward pain nursing from 95.4% to 100% (all P-values <0.05). Oral morphine equivalent dosage in the good pain management ward increased from 2.3 mg/patient before June 2012 to 54.74 mg/patient in 2014. From 2011 to 2015, the oral morphine equivalent dose per discharged patient increased from 8.52 mg/person to 20.36 mg/person. A 100% implementation rate of independent double-check prior to narcotics dosing has been achieved since January 2013. From 2014 to 2015, the ratio of number of narcotics-related medication errors to number of discharged patients significantly decreased (6.95% versus 0.99%, P=0.0000). Taken together, continuous quality improvements have been

  6. Refining American Joint Committee on Cancer/Union for International Cancer Control TNM stage and prognostic groups for human papillomavirus-related oropharyngeal carcinomas.

    Science.gov (United States)

    Huang, Shao Hui; Xu, Wei; Waldron, John; Siu, Lillian; Shen, Xiaowei; Tong, Li; Ringash, Jolie; Bayley, Andrew; Kim, John; Hope, Andrew; Cho, John; Giuliani, Meredith; Hansen, Aaron; Irish, Jonathan; Gilbert, Ralph; Gullane, Patrick; Perez-Ordonez, Bayardo; Weinreb, Ilan; Liu, Fei-Fei; O'Sullivan, Brian

    2015-03-10

    To refine stage and prognostic group for human papillomavirus (HPV) -related nonmetastatic (M0) oropharyngeal cancer (OPC). All patients with nonmetastatic (M0) p16-confirmed OPC treated with radiotherapy with or without chemotherapy from 2000 to 2010 were included. Overall survival (OS) was compared among TNM stages for patients with HPV-related and HPV-unrelated OPC separately. For HPV-related OPC, recursive partitioning analysis (RPA) derived new RPA stages objectively. Cox regression was used to calculate adjusted hazard ratios (AHRs) to derive AHR stages. The performance of survival prediction of RPA stage and AHR stage was assessed against the current seventh edition TNM stages. Prognostic groups were derived by RPA, combining RPA stage and nonanatomic factors. The cohort comprised 573 patients with HPV-related OPC and 237 patients with HPV-unrelated OPC, with a median follow-up of 5.1 years. Lower 5-year OS with higher TNM stage was evident for patients with HPV-unrelated OPC (stage I, II, III, and IV 5-year OS: 70%, 58%, 50%, and 30%, respectively; P = .004) but not for patients with HPV-related OPC (stage I, II, III, and IV 5-year OS: 88%, 78%, 71%, and 74%, respectively; P = .56). RPA divided HPV-related OPC into RPA-I (T1-3N0-2b), RPA-II (T1-3N2c), and RPA-III (T4 or N3; 5-year OS: 82%, 76%, and 54%, respectively; P 20 PY), group III (T4 or N3_age ≤ 70), and group IVA (T4 or N3_age > 70; 5-year OS: 89%, 64%, 57%, and 40%, respectively; P TNM stage grouping (stage I/II/III: T1-3N0-N2b/T1-3N2c/T4 or N3, with M1 as stage IV) is proposed for HPV-related OPC as a result of significantly improved survival prediction compared with the seventh edition TNM, and prognostication is further improved by an RPA-based prognostic grouping within the American Joint Committee on Cancer/Union for International Cancer Control TNM framework for HPV-related OPC. © 2015 by American Society of Clinical Oncology.

  7. Alien invasive species and biological pollution of the Great Lakes Basin ecosystem[Great Lakes Water Quality Board : Report to the International Joint Commission

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-05-01

    The displacement of important native species in the Great Lakes is a result of an invasion by a succession of non indigenous aquatic species. These invasion also resulted in interference with the proper human water uses and cost billions of dollars. The problem was considered serious enough that the International Joint Commission asked the Great Lakes Water Quality Board in 1999 to review the regulations in place and make recommendations, if necessary, for the implementation of additional measures that could be considered to keep control over the introduction of alien invasive species. Escapes from aquaria, aquaculture, research and educational facilities, canal and diversion water flows, and release of live bait are all sources of this invasion. The effectiveness of alternative technologies to control the invasion was to be examined by the Board. Other efforts taking place to address the situation in the basin are being complemented by the publication of this report. It is considered that the most important source of alien invasive species (AIS) to the Great Lakes is the discharge of ballast water from shipping vessels coming from outside the United States and Canada. A major concern is the role played by vessels reporting no ballast on board (NOBOB) upon entering the basin. A number of recommendations were made concerning: (1) implementation and enforcement of the ballast water discharge standards agreed upon by both countries, (2) the evaluation of the effectiveness of alternative technologies to achieve ballast water discharge standards over the long term, combined with the use of chemical treatment while the evaluation is being performed, (3) the implementation of optimal management practices to control sediments in shipping vessels, (4) modifications to the design of shipping vessels, and (5) the monitoring and contingency plans in the event of a repeat scenario in the future. Composed of an equal number representatives from the United States and Canada, at

  8. Coating multilayer material with improved tribological properties obtained by magnetron sputtering

    Science.gov (United States)

    Mateescu, A. O.; Mateescu, G.; Balasoiu, M.; Pompilian, G. O.; Lungu, M.

    2017-02-01

    This work is based on the Patent no. RO 128094 B1, granted by the Romanian State Office for Inventions and Trademarks. The goal of the work is to obtain for investigations tribological coatings with multilayer structure with improved tribological properties, deposited by magnetron sputtering process from three materials (sputtering targets). Starting from compound chemical materials (TiC, TiB2 and WC), as sputtering targets, by deposition in argon atmosphere on polished stainless steel, we have obtained, based on the claims of the above patent, thin films of multilayer design with promising results regarding their hardness, elastic modulus, adherence, coefficient of friction and wear resistance. The sputtering process took place in a special sequence in order to ensure better tribological properties to the coating, comparing to those of the individual component materials. The tribological properties, such as the coefficient of friction, are evaluated using the tribometer test.

  9. Tribological Performance Optimization of Electroless Ni-P-W Coating Using Weighted Principal Component Analysis

    Directory of Open Access Journals (Sweden)

    S. Roy

    2013-12-01

    Full Text Available The present investigation is an experimental approach to deposit electroless Ni-P-W coating on mild steel substrate and find out the optimum combination of various tribological performances on the basis of minimum friction and wear, using weighted principal component analysis (WPCA. In this study three main tribological parameters are chosen viz. load (A, speed (B and time(C. The responses are coefficient of friction and wear depth. Here Weighted Principal Component Analysis (WPCA method is adopted to convert the multi-responses into single performance index called multiple performance index (MPI and Taguchi L27 orthogonal array is used to design the experiment and to find the optimum combination of tribological parameters for minimum coefficient of friction and wear depth. ANOVA is performed to find the significance of the each tribological process parameters and their interactions. The EDX analysis, SEM and XRD are performed to study the composition and structural aspects.

  10. THE RESEARCH TECHNIQUES FOR ANALYSIS OF MECHANICAL AND TRIBOLOGICAL PROPERTIES OF COATING-SUBSTRATE SYSTEMS

    Directory of Open Access Journals (Sweden)

    Kinga CHRONOWSKA-PRZYWARA

    2014-06-01

    Full Text Available The article presents research techniques for the analysis of both mechanical and tribological properties of thin coatings applied on highly loaded machine elements. In the Institute of Machine Design and Exploitation, AGH University of Science and Technology students of the second level of Mechanical Engineering study tribology attending laboratory class. Students learn on techniques for mechanical and tribological testing of thin, hard coatings deposited by PVD and CVD technologies. The program of laboratories contains micro-, nanohardness and Young's modulus measurements by instrumental indentations and analysys of coating to substrate adhesion by scratch testing. The tribological properties of the coating-substrate systems are studied using various techniques, mainly in point contact load conditions with ball-on-disc and block-on-ring tribomiters as well as using ball cratering method in strongly abrasive suspensions.

  11. Reduction in tribological energy losses in the transportation and electric utilities sectors

    Energy Technology Data Exchange (ETDEWEB)

    Pinkus, O.; Wilcock, D.F.; Levinson, T.M.

    1985-09-01

    This report is part of a study of ways and means of advancing the national energy conservation effort, particularly with regard to oil, via progress in the technology of tribology. The report is confined to two economic sectors: transportation, where the scope embraces primarily the highway fleets, and electric utilities. Together these two sectors account for half of the US energy consumption. Goal of the study is to ascertain the energy sinks attributable to tribological components and processes and to recommend long-range research and development (R and D) programs aimed at reducing these losses. In addition to the obvious tribological machine components such as bearings, piston rings, transmissions and so on, the study also extends to processes which are linked to tribology indirectly such as wear of machine parts, coatings of blades, high temperature materials leading to higher cycle efficiencies, attenuation of vibration, and other cycle improvements.

  12. Nano/micro tribological behaviors of a self-assembled graphene oxide nanolayer on Ti/titanium alloy substrates

    Science.gov (United States)

    Li, Peng Fei; Zhou, Hua; Cheng, Xian-Hua

    2013-11-01

    In this study, reduced graphene oxide (RGO) layer is prepared on a self-assembled monolayer (SAM) of 3-aminopropyltriethoxysilane (APTES) modified surface of deposited Ti substrates or Ti-29Nb-13Ta-4.6Zr (TNTZ) alloy substrate. The surface morphology was measured by SEM and AFM. Tribological behaviors in nano scale by AFM and in micro scale by UMT-2 were investigated and compared with titanium substrate, APTES SAM and GO-APTES nanolayer. XPS, water contact angle (WCA) and ellipsometry tests were carried out as assistant methods to discuss the tribological mechanisms. In both nano and micro scale tribological tests, the prepared film holds remarkable tribological properties. It also shows good anti-wear performance in our designed bio-tribological test. Nano and micro tribological mechanisms of the film are discussed.

  13. Interreader agreement in the assessment of magnetic resonance images of rheumatoid arthritis wrist and finger joints--an international multicenter study

    DEFF Research Database (Denmark)

    Østergaard, Mikkel; Klarlund, Mette; Lassere, M;

    2001-01-01

    Magnetic resonance imaging (MRI) allows direct visualization of inflammation and destruction in rheumatoid arthritis (RA) joints. However, MRI scoring methods have not yet been standardized or appropriately validated. Our aim was to examine interreader agreement for a simple system of scoring RA...... spin-echo, -/+ fat saturation (FS), -/+ iv gadolinium (Gd)] were scored for synovitis (score 0-3) and bone lesions (0-3). In substudy 2, we evaluated 19 sets of 2nd-5th MCP joints [10 sets from UK (Technique A) and 9 sets from the US (Technique B: 1.5 T; coronal T1 spin-echo and T2* gradient-echo + FS......, no Gd)] and 19 wrist joints [9 from the US (Technique B) and 10 from Denmark (Technique C: 1.0 T; coronal and axial T1 spin-echo, no FS, -/+ Gd)]. Synovitis (0-3), bone lesions (0-3), and joint space narrowing (JSN, 0-3) were scored in each MCP joint and in 3 different regions of the wrist. Bone...

  14. Tribological synthesis method for producing low-friction surface film coating

    Energy Technology Data Exchange (ETDEWEB)

    Ajayi, Oyelayo O.; Lorenzo-Martin, Maria De La; Fenske, George R.

    2016-10-25

    An article of method of manufacture of a low friction tribological film on a substrate. The article includes a substrate of a steel or ceramic which has been tribologically processed with a lubricant containing selected additives and the additives, temperature, load and time of processing can be selectively controlled to bias formation of a film on the substrate where the film is an amorphous structure exhibiting highly advantageous low friction properties.

  15. Tribological characteristics of UHMWPE composite and relationship with its compressive behavior

    Institute of Scientific and Technical Information of China (English)

    LI Jian; GUO Zhiguang; HUA Meng; QIN Xiangpei; WEN Shizhu

    2004-01-01

    The triboogical characteristics and the mechanics compress behaviors of pure and composite ultra high molecular weight polyethylene (UHMWPE) were investigated using tribological apparatus and universal materials testing apparatus respectively.Results show that there are direct relationships between the sliding friction, wear characteristics, and compression behaviors of UHMWPE composite. The composite of UHMWPE with added copper particles had great improvement in tribological characteristics and mechanics behaviors. Based on the experimental results, a microstructure model of UHMWPE-copper composite is preliminarily proposed.

  16. Joint Performance and Planning System

    Data.gov (United States)

    US Agency for International Development — A joint State/USAID system hosted by State that integrates resource and performance information at the program level and enables more flexible and frequent entry of...

  17. Interreader agreement in the assessment of magnetic resonance images of rheumatoid arthritis wrist and finger joints--an international multicenter study

    DEFF Research Database (Denmark)

    Østergaard, Mikkel; Klarlund, Mette; Lassere, M

    2001-01-01

    changes on MRI among 5 centers that had not undertaken intergroup calibration. MRI of RA wrist and metacarpophalangeal (MCP) joints were scored by experienced readers in 5 centers in different countries. In substudy 1, 5 sets of 2nd-5th MCP joints from UK [Technique A: 1.5 T, coronal and axial T1 and T2...... spin-echo, -/+ fat saturation (FS), -/+ iv gadolinium (Gd)] were scored for synovitis (score 0-3) and bone lesions (0-3). In substudy 2, we evaluated 19 sets of 2nd-5th MCP joints [10 sets from UK (Technique A) and 9 sets from the US (Technique B: 1.5 T; coronal T1 spin-echo and T2* gradient-echo + FS...

  18. Sequence of Stages in the Microstructure Evolution in Copper under Mild Reciprocating Tribological Loading.

    Science.gov (United States)

    Greiner, Christian; Liu, Zhilong; Strassberger, Luis; Gumbsch, Peter

    2016-06-22

    Tailoring the surface properties of a material for low friction and little wear has long been a goal of tribological research. Since the microstructure of the material under the contact strongly influences tribological performance, the ability to control this microstructure is thereby of key importance. However, there is a significant lack of knowledge about the elementary mechanisms of microstructure evolution under tribological load. To cover different stages of this microstructure evolution, high-purity copper was investigated after increasing numbers of sliding cycles of a sapphire sphere in reciprocating motion. Scanning electron and focused ion beam (FIB) microscopy were applied to monitor the microstructure changes. A thin tribologically deformed layer which grew from tens of nanometers to several micrometers with increasing number of cycles was observed in cross-sections. By analyzing dislocation structures and local orientation changes in the cross-sectional areas, dislocation activity, the occurrence of a distinct dislocation trace line, and the emergence of new subgrain boundaries could be observed at different depths. These results strongly suggest that dislocation self-organization is a key elementary mechanism for the microstructure evolution under a tribological load. The distinct elementary processes at different stages of sliding identified here will be essential for the future modeling of the microstructure evolution in tribological contacts.

  19. Research and development of utilization technology of solar thermal energy system for industrial and other use. International joint technology development for solar energy utilization systems; Sangyoyo nado solar system jitsuyoka gijutsu kaihatsu. Taiyo energy riyo system kokusai kyodo gijutsu kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    Takita, M. [New Energy and Industrial Technology Development Organization, Tokyo (Japan)

    1994-12-01

    Described herein are the results of the FY1994 research program for international joint technology development for solar energy utilization systems. The joint study with an Indonesian research institute takes a model of lumber drying plant for the design and feasibility study. All the parts it needs are technically available in Indonesia, except carbon fiber sheets and electronic devices for controlling purposes. The drying cost is higher than that of a plant which procures charge-free wood fuel, but lower than that of a plant which procures fuel at 30$/t. A cacao drying plant model is also studied. The feasibility study shows that the initial investment for the blowing-up model is much higher by 60% to 100% than that for the conventional plant. Its fuel cost is lower by 11% than that of residual oil but 27% higher than that of wood. 4 figs.

  20. Investigation on the Mechanical and Tribological Properties of Aluminium-Tin Based Plain Bearing Material

    Directory of Open Access Journals (Sweden)

    T. Rameshkumar

    2010-06-01

    Full Text Available The purpose of this study is to investigate the Mechanical and Tribological properties of plain bearing alloys used especially in internal combustion engines. The mechanical properties namely Tensile strength and Hardness were investigated according to standard procedure. The sliding friction and wear properties of aluminium-tin alloy against high carbon high chromium steel were investigated at different normal loads as (29.43 N, 33.35 N and 36.25 N. Tests were carried in oil lubricated conditions with a sliding speed of 1 m/s. Prior to experimentation, the circulating engine oil 20w40 was heated to temperature of 800C using heater. The frictional behavior and wear property of aluminium-tin alloy were studied by means of pin-on-disk tribometer. The weight loss of the specimen was measured and wear and friction characteristics were calculated with respect to time, depth of wear track, sliding speed and bearing load. To determine the wear mechanism, the worn surfaces of the samples were examined using Scanning Electron Microscope (SEM. The optimum wear reduction was obtained at different normal loads and at same sliding speed.

  1. Relationship between molecular structure and tribological properties of phosphazene lubricants

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Cyclotriphosphazene lubricants were synthesized and the relationship between theirstructures and tribological properties was investigated using an Optimol SRV oscillating frictionand wear tester and one-way reciprocating friction tester. It was found that aryloxyphosphazenewith polar substituent as a lubricant of steel/steel and steel/aluminum pair gave low wear, whilearyloxyphosphazene with nonpolar group on the phenyl pendant led to high wear. Phosphazeneprovides poor lubricity for steel/aluminum system under low load (0.5-3 N). The XPS analyticalresults of the antiwear films generated on the steel and aluminum surface indicate that phos-phazene reacted with steel or aluminum counterface and formed a surface protecting film consist-ing of fluoride and organic compounds containing O, C, F, N, P during friction. This contributes tcreduce the friction and wear of steel/aluminum system.

  2. Mechanical and Tribological Properties of Carbon-Based Graded Coatings

    Directory of Open Access Journals (Sweden)

    M. Kot

    2016-01-01

    Full Text Available The paper presents research on coatings with advanced architecture, composed of a Cr/Cr2N ceramic/metal multilayer and graded carbon layers with varying properties from Cr/a-C:H to a-C:N. The microstructure of the coatings was analysed using transmission electron microscopy and Energy Dispersive Spectroscopy, the mechanical properties were tested by nanoindentation, spherical indentation, and scratch testing, and tribological tests were also conducted. The proper selection of subsequent layers in graded coatings allowed high hardness and fracture resistance to be obtained as well as good adhesion to multilayers. Moreover, these coatings have higher wear resistance than single coatings and a friction coefficient equal to 0.25.

  3. Tribological performance analysis of textured steel surfaces under lubricating conditions

    Science.gov (United States)

    Singh, R. C.; Pandey, R. K.; Rooplal; Ranganath, M. S.; Maji, S.

    2016-09-01

    The tribological analysis of the lubricated conformal contacts formed between the smooth/textured surfaces of steel discs and smooth surface of steel pins under sliding conditions have been considered. Roles of dimples’ pitch of textured surfaces have been investigated experimentally to understand the variations of coefficient of friction and wear at the tribo-contacts under fully flooded lubricated conditions. Substantial reductions in coefficient of friction and wear at the tribo-interfaces have been observed in presence of textures on the rotating discs for both fully flooded and starved conditions in comparison to the corresponding lubricating conditions of the interfaces formed between the smooth surfaces of disc and pin. In presence of surface texture, the coefficient of friction reduces considerable at elevated sliding speeds (>2 m/s) and unit loads (>0.5 MPa) for the set of operating parameters considered in the analysis.

  4. [Modern tribology in total hip arthroplasty: pros and cons].

    Science.gov (United States)

    Gómez-García, F

    2014-01-01

    The wear products and adverse reactions that occur on bearing surfaces represent one of the greatest challenges in prosthetic replacements, as the latter experience increasing demands due to the large number of young and older adult patients that have a long life expectancy and remarkable activity. The purpose of this review is to analyze the pros and cons of the new advances in the bearing components of the articular surfaces of current total hip arthroplasties. We also discuss the strategies used historically, their problems, results and the surgeon's role in prescribing the tribologic couple that best fits each patient's needs. We conclude with practical recommendations for the prescription and management of the latest articular couples for total hip arthroplasty.

  5. Tribological and electrochemical studies on biomimetic synovial fluids

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    In this study, tribological and electrochemical performances of the new biomimetic synovial fluids were studied according to different composition concentrations, including hyaluronic acid, albumin and alendronic acid sodium. By using Taguchi method, the composition contents of the biomimetic synovial fluids were designed. Items such as friction coefficient, mean scar diameter and viscosity were investigated via a four-ball tribo-tester, viscosity meter and optical microscope. Polarization studies were carried out to analyze the electrochemical behaviour of the fluids. Results showed that hyaluronic acid dominates the viscosity of the fluids. High albumin concentration will reduce friction, while increasing wear rate due to the electro-chemical effect. Alendronic acid sodium is found to reduce the biocorrosion of CoCrMo as well as provide better lubricating. In conclusion, biomimetic synovial fluids partially recover the functions of natural synovial fluids and provide good lubricating property.

  6. The effect of normal load on polytetrafluoroethylene tribology.

    Science.gov (United States)

    Barry, Peter R; Chiu, Patrick Y; Perry, Scott S; Sawyer, W Gregory; Phillpot, Simon R; Sinnott, Susan B

    2009-04-08

    The tribological behavior of oriented poly(tetrafluoroethylene) (PTFE) sliding surfaces is examined as a function of sliding direction and applied normal load in classical molecular dynamics (MD) simulations. The forces are calculated with the second-generation reactive empirical bond-order potential for short-range interactions, and with a Lennard-Jones potential for long-range interactions. The range of applied normal loads considered is 5-30 nN. The displacement of interfacial atoms from their initial positions during sliding is found to vary by a factor of seven, depending on the relative orientation of the sliding chains. However, within each sliding configuration the magnitude of the interfacial atomic displacements exhibits little dependence on load over the range considered. The predicted friction coefficients are also found to vary with chain orientation and are in excellent quantitative agreement with experimental measurements.

  7. Particle-wall tribology of slippery hydrogel particle suspensions.

    Science.gov (United States)

    Shewan, Heather M; Stokes, Jason R; Cloitre, Michel

    2017-02-22

    Slip is an important phenomenon that occurs during the flow of yield stress fluids like soft materials and pastes. Densely packed suspensions of hydrogel microparticles are used to show that slip is governed by the tribological interactions occurring between the samples and shearing surfaces. Both attractive/repulsive interactions between the dispersed particles and surface, as well as the viscoelasticity of the suspension, are found to play key roles in slip occurring within rheometric flows. We specifically discover that for two completely different sets of microgels, the sliding stress at which slip occurs scales with both the modulus of the particles and the bulk suspension modulus. This suggests that hysteresis losses within the viscoelastic particles contribute to friction forces and thus slip at the particle-surface tribo-contact. It is also found that slip during large amplitude oscillatory shear and steady shear flows share the same generic features.

  8. Tribological Aspect of Rubber Based Parts used in Engineering

    Directory of Open Access Journals (Sweden)

    D. Stamenković

    2014-03-01

    Full Text Available In most of the cases, the friction is considered as a negative side-effect concerning energy loss following every process of the power transmission. However, the friction has significant positive side effects, because it is an indispensable prerequisite for the movement of people, machines, transportation means and others. Efficiency of these movements mostly depends on the friction between rubber and different materials such as metals, concrete, earth, wood, plastic, etc. Certain standards relating to measurement and determination of the friction characteristics of rubber were established. However considering that tribology of the rubber is very complex problem, numerous studies around the world are conducted. This paper gives an overview of some of the existing standards and conducted researches in this area. The paper also provides an overview of theoretical and experimental studies of friction the rubber and the other materials, which are done at Faculty of Mechanical Engineering in Niš.

  9. Micromechanisms of friction and wear introduction to relativistic tribology

    CERN Document Server

    Lyubimov, Dmitrij; Pinchuk, Leonid

    2013-01-01

    The modern vision of the micromechanism of friction and wear is explored, from the examination of ideal and real crystal structure and adhesion properties to the dynamics of solid frictional interaction. The fundamental quantum-mechanical and relativity principles of particle interaction are considered as basis of friction micro-process examination. The changes in solid structure originated from the influence of different kinds of force fields are considered. The principal possibility of relativity effect manifestation by friction is explained. The critical state of friction – triboplasma – was studied. Structural peculiarities of triboplasma, the kinetics of its transformation during frictional interaction as well as the influence of plasma and postplasma processes on tribojunction friction characteristics and complex formation by friction were examined. The book addresses to tribology researchers.

  10. Material, Mechanical, and Tribological Characterization of Laser-Treated Surfaces

    Science.gov (United States)

    Yilbas, Bekir Sami; Kumar, Aditya; Bhushan, Bharat; Aleem, B. J. Abdul

    2014-10-01

    Laser treatment under nitrogen assisting gas environment of cobalt-nickel-chromium-tungsten-based superalloy and high-velocity oxygen-fuel thermal spray coating of nickel-chromium-based superalloy on carbon steel was carried out to improve mechanical and tribological properties. Superalloy surface was preprepared to include B4C particles at the surface prior to the laser treatment process. Material and morphological changes in the laser-treated samples were examined using scanning electron microscopy, energy-dispersive spectroscopy, and x-ray diffraction (XRD) analysis. Residual stresses present at the surface region of the laser-treated layer were determined from the XRD data. The microhardness of the laser-treated surface was measured by indentation tests. Fracture toughness of the coating surfaces before and after laser treatment were also measured using overload indentation tests. Macrowear and macrofriction characterization were carried out using pin-on-disk tests.

  11. The Influence of Irradiation and Accelerated Aging on the Mechanical and Tribological Properties of the Graphene Oxide/Ultra-High-Molecular-Weight Polyethylene Nanocomposites

    Directory of Open Access Journals (Sweden)

    Guodong Huang

    2016-01-01

    Full Text Available Graphene oxide/ultra-high-molecular-weight polyethylene (GO/UHMWPE nanocomposite is a potential and promising candidate for artificial joint applications. However, after irradiation and accelerated aging, the mechanical and tribological behaviors of the nanocomposites are still unclear and require further investigation. GO/UHMWPE nanocomposites were successfully fabricated using ultrasonication dispersion, ball-milling, and hot-pressing process. Then, the nanocomposites were irradiated by gamma ray at doses of 100 kGy. Finally, GO/UHMWPE nanocomposites underwent accelerated aging at 80°C for 21 days in air. The mechanical and tribological properties of GO/UHMWPE nanocomposites have been evaluated after irradiation and accelerated aging. The results indicated that the incorporation of GO could enhance the mechanical, wear, and antiscratch properties of UHMWPE. After irradiation, these properties could be further enhanced, compared to unirradiated ones. After accelerated aging, however, these properties have been significantly reduced when compared to unirradiated ones. Moreover, GO and irradiation can synergistically enhance these properties.

  12. Comparison of the Treatment Implications of American Society of Hypertension and International Society of Hypertension 2013 and Eighth Joint National Committee Guidelines: an analysis of National Health and Nutrition Examination Survey.

    Science.gov (United States)

    Murthy, Venkatesh L; Shah, Ravi V; Rubenfire, Melvyn; Brook, Robert D

    2014-08-01

    Multiple guidelines and statements related to hypertension have recently been published. Much discord has arisen from discrepant treatment and target systolic blood pressure thresholds for individuals aged 60 to 79 years of Hypertension and International Society of Hypertension 2013. We sought to evaluate the public health implications of these differences using data from the 2005 to 2010 National Health and Nutrition Examination Survey (NHANES) cycles. NHANES is an ongoing survey designed to allow characterization of the US population and subpopulations. We found that only .2.4% (95% confidence interval, 1.5.3.2%) of adults aged 60 to 79 years had indications for antihypertensive treatment under the more stringent American Society of Hypertension and International Society of Hypertension 2013 guideline but not under Eighth Joint National Committee. About 65.7% (95% confidence interval, 62.4.69.0%) of adults aged 60 to 79 years had indications for treatment under both guidelines. Furthermore, those with indications for treatment under American Society of Hypertension and International Society of Hypertension 2013 but not under Eighth Joint National Committee generally had higher systolic blood pressure and less favorable lipid profiles compared with those with indications for treatment under both guidelines. Importantly, a larger group, comprising 21.0% (95% confidence interval, 18.7.23.2%) of adults aged 60 to 79 years, had either untreated or inadequately treated hypertension and represents an important group for continued efforts.

  13. Tribology of carbide derived carbon films synthesized on tungsten carbide

    Science.gov (United States)

    Tlustochowicz, Marcin

    Tribologically advantageous films of carbide derived carbon (CDC) have been successfully synthesized on binderless tungsten carbide manufactured using the plasma pressure compaction (P2CRTM) technology. In order to produce the CDC films, tungsten carbide samples were reacted with chlorine containing gas mixtures at temperatures ranging from 800°C to 1000°C in a sealed tube furnace. Some of the treated samples were later dechlorinated by an 800°C hydrogenation treatment. Detailed mechanical and structural characterizations of the CDC films and sliding contact surfaces were done using a series of analytical techniques and their results were correlated with the friction and wear behavior of the CDC films in various tribosystems, including CDC-steel, CDC-WC, CDC-Si3N4 and CDC-CDC. Optimum synthesis and treatment conditions were determined for use in two specific environments: moderately humid air and dry nitrogen. It was found that CDC films first synthesized at 1000°C and then hydrogen post-treated at 800°C performed best in air with friction coefficient values as low as 0.11. However, for dry nitrogen applications, no dechlorination was necessary and both hydrogenated and as-synthesized CDC films exhibited friction coefficients of approximately 0.03. A model of tribological behavior of CDC has been proposed that takes into consideration the tribo-oxidation of counterface material, the capillary forces from adsorbed water vapor, the carbon-based tribofilm formation, and the lubrication effect of both chlorine and hydrogen.

  14. Ceramic joints

    Science.gov (United States)

    Miller, Bradley J.; Patten, Jr., Donald O.

    1991-01-01

    Butt joints between materials having different coefficients of thermal expansion are prepared having a reduced probability of failure of stress facture. This is accomplished by narrowing/tapering the material having the lower coefficient of thermal expansion in a direction away from the joint interface and not joining the narrow-tapered surface to the material having the higher coefficient of thermal expansion.

  15. Safe medication management and use of narcotics in a Joint Commission International-accredited academic medical center hospital in the People’s Republic of China

    Directory of Open Access Journals (Sweden)

    Fang X

    2016-04-01

    Full Text Available Xu Fang,1,2 Ling-ling Zhu,3 Sheng-dong Pan,4 Ping Xia,4 Meng Chen,5 Quan Zhou51Office of Hospital Administration, 2Office of Party and Administration Council, 3Geriatric VIP Care Ward, Division of Nursing, 4Division of Medical Administration, 5Department of Pharmacy, the Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang Province, People’s Republic of ChinaAbstract: Safe medication management and use of high-alert narcotics should arouse concern. Risk management experiences in this respect in a large-scale Joint Commission International (JCI-accredited academic medical center hospital in the People’s Republic of China during 2011–2015, focusing on organizational, educational, motivational, and information technological measures in storage, prescribing, preparing, dispensing, administration, and monitoring of medication are summarized. The intensity of use of meperidine in hospitalized patients in 2015 was one-fourth that in 2011. A 100% implementation rate of standard storage of narcotics has been achieved in the hospital since December 2012. A “Plan, Do, Check, Act” cycle was efficient because the ratio of number of inappropriate narcotics prescriptions to total number of narcotics prescriptions for inpatients decreased from August 2014 to December 2014 (28.22% versus 2.96%, P=0.0000, and it was controlled below 6% from then on. During the journey to good pain management ward accreditation by the Ministry of Health, People’s Republic of China, (April 2012–October 2012, the medical oncology ward successfully demonstrated an increase in the pain screening rate at admission from 43.5% to 100%, cancer pain control rate from 85% to 96%, and degree of satisfaction toward pain nursing from 95.4% to 100% (all P-values <0.05. Oral morphine equivalent dosage in the good pain management ward increased from 2.3 mg/patient before June 2012 to 54.74 mg/patient in 2014. From 2011 to 2015, the oral morphine

  16. 22 CFR 228.34 - Joint ventures.

    Science.gov (United States)

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Joint ventures. 228.34 Section 228.34 Foreign Relations AGENCY FOR INTERNATIONAL DEVELOPMENT RULES ON SOURCE, ORIGIN AND NATIONALITY FOR COMMODITIES AND... Financing § 228.34 Joint ventures. A joint venture or unincorporated association is eligible only if each...

  17. Study on the International Law Dilemma and Path of the Mekong River Joint Cruise%湄公河联合巡航的国际法困境与路径

    Institute of Scientific and Technical Information of China (English)

    满先进

    2015-01-01

    With the in-depth development of the Greater Mekong Sub-region Program, the area of golden waterway--The Mekong river has unprecedented prosperity, but some transnational crimes such as gun trafficking, human trafficking, murder and robbery behaviors have been emerging. In order to ensure the safety of the Mekong river channel, and China, Laos, Myanmar, Thailand quartet take Joint cruise enforcement actions in the Mekong river. However, in the process of joint cruise, and law enforcement personnel who face joint cruise cooperation mechanism is not sound, the consciousness of absolute sovereignty conflicting with the practice of the joint cruise, foreign intervention and Southeast Asian countries at the stage of "instrumental trust" and so on many international law dilemmas. Therefore, we should improve the international cooperation mechanism under the principle of "equal consultation", implementation "sovereignty transfer " in line with the principles of "respect for state sovereignty", and enhance international trust in line with the principles of international cooperation.%随着大湄公河次区域经济合作(GMS)的深入开展,该区域的黄金水道———湄公河迎来了前所未有的繁荣,但是一些贩毒、贩枪、贩人及杀人抢劫等跨国犯罪行为也随之涌现。为了保障湄公河航道安全,中老缅泰四国组织开展湄公河联合巡航执法行动。但是在联合巡航的过程中,各国执法人员面临着联合巡航的合作机制不健全、绝对国家主权观念与联合巡航的实践冲突、国外势力介入及东南亚各国“工具性信任”模式的影响等诸多国际法困境。为此,应在“平等协商”的原则下完善国际合作机制;应在“尊重国家主权”的原则下实现“主权让渡”;应在国际合作的原则下增强国际信任。

  18. Highlights From the American Association of Pharmaceutical Scientists/ International Transporter Consortium Joint Workshop on Drug Transporters in Absorption, Distribution, Metabolism, and Excretion: From the Bench to the Bedside - Clinical Pharmacology Considerations.

    Science.gov (United States)

    Ronaldson, P T; Bauer, B; El-Kattan, A F; Shen, H; Salphati, L; Louie, S W

    2016-11-01

    The American Association of Pharmaceutical Scientists/International Transporter Consortium Joint Workshop on Drug Transporters in absorption, distribution, metabolism, and excretion was held with the objective of discussing innovative advances in transporter pharmacology. Specific topics included (i) transporters at the blood-brain barrier (BBB); (ii) emerging transport proteins; (iii) recent advances in achieving hepatoselectivity and optimizing clearance for organic anion-transporting polypeptide (OATP) substrates; (iv) utility of animal models for transporter studies; and (v) clinical correlation of transporter polymorphisms. Here, we present state-of-the-art highlights from this workshop in these key areas of focus.

  19. Introduction to the special issue on the joint meeting of the 19th IEEE International Symposium on the Applications of Ferroelectrics and the 10th European Conference on the Applications of Polar Dielectrics.

    Science.gov (United States)

    Tsurumi, Takaaki

    2011-09-01

    The joint meeting of the 19th IEEE International Symposium on the Applications of Ferroelectrics and the 10th European Conference on the Applications of Polar Dielectrics took place in Edinburgh from August 9-12, 2010. The conference was attended by 390 delegates from more than 40 different countries. There were 4 plenary speakers, 56 invited speakers, and a further 222 contributed oral presentations in 7 parallel session. In addition there were 215 poster presentations. Key topics addressed at the conference included piezoelectric materials, leadfree piezoelectrics, and multiferroics.

  20. Temporomandibular Joint, Closed

    Science.gov (United States)

    ... Gallery > Oral Health > The Temporomandibular Joint, Closed The Temporomandibular Joint, Closed Main Content Title: The Temporomandibular Joint, Closed Description: The temporomandibular joint connects the lower ...

  1. The role of pain and functional impairment in the decision to recommend total joint replacement in hip and knee osteoarthritis: an international cross-sectional study of 1909 patients. Report of the OARSI-OMERACT Task Force on total joint replacement

    DEFF Research Database (Denmark)

    Gossec, L; Paternotte, S; Maillefert, J F;

    2011-01-01

    Score Physical function Short-form, 0-100). Analyses: Comparison of patients with vs without surgeons' indication for TJR. Receiver Operating Characteristic (ROC) curve analyses and logistic regression were applied to determine cut points of pain and disability defining recommendation for TJR. RESULTS......OBJECTIVE: To assess the pain and functional disability levels corresponding to an indication for total joint replacement (TJR) in hip and knee osteoarthritis (OA). METHODS: Design: International cross-sectional study in 10 countries. Patients: Consecutive outpatients with definite hip or knee OA...

  2. Development of devices for self-injection: using tribological analysis to optimize injection force

    Directory of Open Access Journals (Sweden)

    Lange J

    2016-05-01

    Full Text Available Jakob Lange, Leos Urbanek, Stefan BurrenYpsomed Delivery Systems, Ypsomed AG, Burgdorf, Switzerland Abstract: This article describes the use of analytical models and physical measurements to characterize and optimize the tribological behavior of pen injectors for self-administration of biopharmaceuticals. One of the main performance attributes of this kind of device is its efficiency in transmitting the external force applied by the user on to the cartridge inside the pen in order to effectuate an injection. This injection force characteristic is heavily influenced by the frictional properties of the polymeric materials employed in the mechanism. Standard friction tests are available for characterizing candidate materials, but they use geometries and conditions far removed from the actual situation inside a pen injector and thus do not always generate relevant data. A new test procedure, allowing the direct measurement of the coefficient of friction between two key parts of a pen injector mechanism using real parts under simulated use conditions, is presented. In addition to the absolute level of friction, the test method provides information on expected evolution of friction over lifetime as well as on expected consistency between individual devices. Paired with an analytical model of the pen mechanism, the frictional data allow the expected overall injection system force efficiency to be estimated. The test method and analytical model are applied to a range of polymer combinations with different kinds of lubrication. It is found that material combinations used without lubrication generally have unsatisfactory performance, that the use of silicone-based internal lubricating additives improves performance, and that the best results can be achieved with external silicone-based lubricants. Polytetrafluoroethylene-based internal lubrication and external lubrication are also evaluated but found to provide only limited benefits unless used in

  3. Joint pain

    Science.gov (United States)

    ... or conditions. It may be linked to arthritis , bursitis , and muscle pain . No matter what causes it, ... Autoimmune diseases such as rheumatoid arthritis and lupus Bursitis Chondromalacia patellae Crystals in the joint: Gout (especially ...

  4. FY1998 report on a survey related to joint utilization of welfare device development data using an international network; 1998 nendo kokusai network ni yoru fukushi kiki kaihatsu data no kyodo riyo ni kansuru chosa hokokusho

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-03-01

    A survey was made in relation with joint utilization of welfare device development data using an international network. Developing welfare devices requires data from ergonomic and medical systems, while the cope of the objects is wide, and the kinds are various. For proliferation of welfare devices, system compatibility evaluation including that on using environment is important, including living environments that are different by countries. The present survey has identified how data for aged, handicapped and help-needing persons are accumulated and utilized in research organizations in America and Europe for both of the ergonomic and medical areas. The survey also investigated major academic societies in overseas countries, and collected database and academic network information that support the advanced research and development. At the same time, investigations were also made on organizations and corporations who are moving forward the efficient data utilization. Welfare device and service information providing systems in Japan were investigated to compare them with the trends in other countries. Conceptions and methods were compiled to utilize data internationally and jointly. Database models for device development were considered, and a proposal was made on structuring a research and development supporting database, and the operation method thereof. (NEDO)

  5. Tribological coating of titanium alloys by laser processing

    Science.gov (United States)

    Pang, Wang

    Titanium-based alloys have been used for aerospace materials for many years. Recently, these alloys are now being increasingly considered for automotive, industrial and consumer applications. Their excellent creep resistance, corrosion resistance and relative higher specific strength ratio are attractive for many applications. However, the main obstacle for the wide adoption of Ti alloys in various industries is their poor tribological properties. In slide wear, Ti deforms and adhesive wear readily occurs. Their poor tribological properties are mainly due to low hardness and absolute values of tensile and shear strength. Different surface modification techniques have been studied in order to improve the tribological characteristics of Ti alloys, i.e. PVD, nitrding, carburizing, boriding, plating etc. Coatings produced by these techniques have their own limitations such as thermal distortion and grain growth. A different approach is to introduce hard particles in the Ti alloy matrix to form a MMC coating, which has tailor-made hardness and wear resistance properties. Laser cladding or laser alloying techniques facilitate the fabrication of surface MMC on Ti alloys without thermal distortion to the substrate. In this project, the fabrication of hard and wear resistant layers of metal matrix composite on titanium alloys substrate by laser surface alloying was investigated. Powder mixtures of Mo and WC were used to form the MMC layer. By optimizing the processing parameters and pre-placed powder mixture compositions, surface MMC of different properties have been successfully fabricated on CP-Ti and Ti6A14V respectively. The structure and characteristics of the MMC surface were investigated by metallography, SEM, XRD, and E-DAX. It was found that the hardness of the laser alloyed Mo/WC MMC surface was 300% higher than that of the CP-Ti substrate Excellent metallurgical bonding with the MMC layer of the substrate has been achieved. The relative kinetic frictional tests

  6. Progress in Tribological Properties of Nano-Composite Hard Coatings under Water Lubrication

    Directory of Open Access Journals (Sweden)

    Qianzhi Wang

    2017-02-01

    Full Text Available The tribological properties, under water-lubricated conditions, of three major nano-composite coatings, i.e., diamond-like carbon (DLC or a-C, amorphous carbon nitride (a-CNx and transition metallic nitride-based (TiN-based, CrN-based, coatings are reviewed. The influences of microstructure (composition and architecture and test conditions (counterparts and friction parameters on their friction and wear behavior under water lubrication are systematically elucidated. In general, DLC and a-CNx coatings exhibit superior tribological performance under water lubrication due to the formation of the hydrophilic group and the lubricating layer with low shear strength, respectively. In contrast, TiN-based and CrN-based coatings present relatively poor tribological performance in pure water, but are expected to present promising applications in sea water because of their good corrosion resistance. No matter what kind of coatings, an appropriate selection of counterpart materials would make their water-lubricated tribological properties more prominent. Currently, Si-based materials are deemed as beneficial counterparts under water lubrication due to the formation of silica gel originating from the hydration of Si. In the meantime, the tribological properties of nano-composite coatings in water could be enhanced at appropriate normal load and sliding velocity due to mixed or hydrodynamic lubrication. At the end of this article, the main research that is now being developed concerning the development of nano-composite coatings under water lubrication is described synthetically.

  7. Rheology and tribology of lubricants with polymeric viscosity modifiers

    Science.gov (United States)

    Babak, LotfizadehDehkordi

    Elastohydrodynamic lubrication (EHL) theory has been used to model the lubrication state of antifriction machine elements, where initial viscosity and pressure viscosity coefficients are essential parameters in film thickness modeling. Since the pressures of lubricants in the contact zone can be very high, it is important to know the rheological properties of lubricants in these pressure and temperature regimes. The characteristics of viscosity behavior as a function of pressure are also essential for a universal definition of the pressure viscosity coefficient in order to estimate film thickness in an EHL regime. In this study, viscosities and pressure-viscosity coefficients of ten commercial engine and gear oils and seventeen laboratory-produced oil/polymer viscosity modifiers (VM) additives are measured up to 1.3 GPa at 40, 75 and 100 °C. For the first time, a sharp increase in the viscosity and piezoviscous factor is observed in both mineral-based and synthetic-based oils with different VMs. Analysis of the experimental results indicates that sharp increase in viscosity observed in these experiments are believed to arise from physical changes in the VMs, that is liquid-solid phase transition. Evidence is offered that polymer properties such as molecular weight, concentration and structure influence the onset of the phase transitions. A modified Yasutomi model, which normally describes the pressure dependence of the viscosity of lubricants very well, fails to predict the viscosity of the specimens above the onset of sharp increase in viscosity. A design of experiment (DOE) analysis using Design-Expert software indicates that pressure and temperature are the most critical parameters in the viscosity variation. Tribological tests demonstrate that wear in the contact, zone occurs at temperatures and stresses that coincides with the VM phase transitions in both commercial and laboratory synthesized oil/VMs. Tribological results also indicate that the onset of the

  8. Investigation of tribological properties of biobased polymers and polymeric composites

    Science.gov (United States)

    Bhuyan, Satyam Kumar

    Worldwide potential demands for replacing petroleum derived raw materials with renewable plant-based ones in the production of valuable polymeric materials and composites are quite significant from the social and environmental standpoints. Therefore, using low-cost renewable resources has deeply drawn the attention of many researchers. Among them, natural oils are expected to be ideal alternative feedstock since oils, derived from plant and animal sources, are found in profusion in the world. The important feature of these types of materials is that they can be designed and tailored to meet different requirements. The real challenge lies in finding applications which would use sufficiently large quantities of these materials allowing biodegradable polymers to compete economically in the market. Lack of material and tribological characterizations have created an awareness to fulfill this essential objective. In order to understand the viability of biobased polymers in structural applications, this thesis work elucidates the study of friction and wear characteristics of polymers and polymeric composites made out of natural oil available profusely in plants and animals. The natural oils used in this study were soybean and tung oil. Various monomeric components like styrene, divinely benzene etc. were used in the synthesis of biobased polymers through Rh-catalyzed isomerization techniques. For the different polymeric composites, spent germ, a byproduct of ethanol production, is used as the filler and an organoclay called montmorillonite is used as the reinforcing agent in the polymer matrix. The effect of crosslinker concentration, filler composition and reinforcement agent concentration was studied under dry sliding. A ball-on-flat tribometer with a probe made out of steel, silicon nitride or diamond was used for most of the experimental work to measure friction and generate wear. The wear tracks were quantified with an atomic force microscope and a contact

  9. Tribological properties of hard carbon films on zirconia ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Erdemir, A.; Bindal, C.; Fenske, G.R. [Argonne National Lab., IL (United States); Wilbur, P. [Colorado State Univ., Fort Collins, CO (United States)

    1995-12-31

    This study investigated the tribological properties of hard diamondlike carbon (DLC) films on magnesia-partially-stabilized zirconia (MgO-PSZ) substrates over a wide range of loads, speeds, temperatures, and counterface materials. The films were 2 {micro}m-thick and produced on by ion-beam deposition at room temperature. Tribological tests were conducted on a ball-on-disk machine in open air of 30 to 50% relative humidity under contact loads of 1 to 50 N, at sliding velocities of 0.1 to 6 m/s, and at temperatures to 400{degrees}C. A1{sub 2}O{sub 3} and Si{sub 3}N{sub 4} balls were also used and rubbed against the DLC-coated MgO-PSZ disks, primarily to assess and compare their friction and wear performance to that of MgO-PSZ balls. A series of long-duration lifetime tests was run at speeds of 1, 2, and 6 m/s under a 5-N load to assess the durability of these DLC films. Test results showed that the friction coefficients of MgO-PSZ balls sliding against MgO-PSZ disks were in the range of 0.5-0.8, and the average specific wear rates of MgO-PSZ balls ranged from 10{sup {minus}5} to 5 {times} 10{sup {minus}4} mm{sup 3}/N.m, depending on sliding velocity, contact load and ambient temperature. The friction coefficients of MgO-PSZ balls sliding against the DLC-coated-MgO-PSZ disks varied between 0.03 to 0.1. The average specific wear rates of MgO-PSZ balls were reduced by factors of three to four orders of magnitude when rubbed against the DLC coated disks. These DLC films could last 1.5 million to 4 million cycles, depending on sliding velocity. Scanning electron microscopy and micro-laser Raman Spectroscopy were used to elucidate the microstructural and chemical nature of DLC films and worn surfaces.

  10. Alternative materials to improve total hip replacement tribology.

    Science.gov (United States)

    Santavirta, Seppo; Böhler, Max; Harris, William H; Konttinen, Yrjö T; Lappalainen, Reijo; Muratoglu, Orhun; Rieker, Claude; Salzer, Martin

    2003-08-01

    An improvement in tribology of bearing surfaces is an effective means of increasing the longevity of total hip replacement (THR). Currently, 3 approaches are available to achieve this aim: first, use of highly cross-linked UHMWPE; second, aluminum oxide ceramic bearings, and third, metal-on-metal bearings. Cross-linking reduces the wear resistance of UHMWPE markedly without impairment of other significant properties of the material. Simulator studies and some clinical long-term (10-22 years) follow-up surveys suggest an almost immeasurable wear of the highly cross-linked UHMWPE-based acetabular components during an expected clinical life span. Bioinert alumina ceramic (aluminum oxide) was introduced 3 decades ago for THR-bearing surfaces to improve performance and longevity. Alumina ceramic is entirely biostable and bioinert and has good mechanical properties. For correctly positioned alumina-on-alumina bearings, the annual linear wear rate has been reported to be 3.9 microm. Alumina heads have been successfully used in combination with polyethylene sockets, but as regards wear, the best results have been obtained with alumina-on-alumina bearings. In ceramic THR bearings, precise manufacture and contact surface geometry, including optimal clearance, are most important. For the currently available products, the component fracture risk is almost nonexistent (less than 1 per 1000). Metal-on-metal bearings were used in the early stage of THR surgery, although not all old designs were successful. More recent analyses of the early series have shown the advantages of metal-on-metal to be better and have led to a renaissance of this articulation. Initially, stainless steel was used because it was easy to manufacture and polish. Current metal-on-metal bearings are based on cobalt-chromium-molybdenum alloys with varying carbon contents. Such bearings are self-polishing. Linear wear rates remain at the level of a few microm a year. An improvement in technology has increased

  11. Tribological Limitations in Gas Turbine Engines: A Workshop to Identify the Challenges and Set Future Directions. Revised

    Science.gov (United States)

    DellaCorte, Chris; Pinkus, Oscar

    2002-01-01

    The following report represents a compendium of selected speaker presentation materials and observations made by Prof. O. Pinkus at the NASA/ASME/Industry sponsored workshop entitled "Tribological Limitations in Gas Turbine Engines" held on September 15-17, 1999 in Albany, New York. The impetus for the workshop came from the ASME's Research Committee on tribology whose goal is to explore new tribological research topics which may become future research opportunities. Since this subject is of current interest to other industrial and government entities the conference received cosponsorship as noted above. The conference was well attended by government, industrial, and academic participants. Topics discussed included current tribological issues in gas turbines as well as the potential impact (drawbacks and advantages) of future tribological technologies especially foil air bearings and magnetic bearings. It is hoped that this workshop report may serve as a starting point for continued discussions and activities in oil-free turbomachinery systems.

  12. Treatment of pedicle screw rod system internal fixation on sacroiliac joint fracture and dislocation%椎弓根钉棒系统固定治疗骶髂关节骨折及脱位分析

    Institute of Scientific and Technical Information of China (English)

    唐理英

    2013-01-01

    Objective To analyze the treatment effects of the iliac screw and pedicle screw rod internal fixation on sacroiliac joint fracture and dislocation and discuss the clinical application value of the pedicle screw rod system in fixation of sacroiliac joint. Methods The double plates fixation via posterior approach was adopted for the patients with sacroiliac joint fracture and dislocation in the control group (n=24),while the iliac screw and pedicle screw rod system internal fixation was adopted for the patients with sacroiliac joint fracture and dislocation in the treatment group (n=24).The clinical effects of the surgeries and the postoperative follow-up of the two groups were compared. Results There were no significant differences (P < 0.05) of the operation time,intraoperative blood loss and fracture healing time between the two groups; All the patients were followed up for 12-18 months. The Majeed score of the treatment group was 95.8%(23/24), which was better than the control group (70.8%(17/24))with significant difference (P<0.05). Conclusion The treatment effect of the iliac screw and pedicle screw rod internal fixation on sacroiliac joint fracture and dislocation is good,which can recover the normal function of joint to the greatest degree and improve the patient’s quality of life.%  目的分析应用髂骨钉与椎弓根钉棒内固定治疗骶髂关节骨折、脱位的治疗效果,探讨椎弓根钉棒系统固定骶髂关节的临床应用价值。方法对照组(n=24)骶髂关节骨折、脱位采用后路双钢板固定治疗,治疗组(n=24)为骶髂关节骨折、脱位患者采用髂骨钉与椎弓根钉棒系统固定术治疗,对比两组的手术临床效果及术后随访情况。结果两组的手术时间、术中出血量、骨折愈合时间均无显著性差异(P<0.05);所有患者均随访12~18个月, Majeed评分治疗组优良率为95.8%(23/24),明显优于对照组的70.8%(17/24),两

  13. Nonarthritic hip joint pain.

    Science.gov (United States)

    Enseki, Keelan; Harris-Hayes, Marcie; White, Douglas M; Cibulka, Michael T; Woehrle, Judith; Fagerson, Timothy L; Clohisy, John C

    2014-06-01

    The Orthopaedic Section of the American Physical Therapy Association (APTA) has an ongoing effort to create evidence-based practice guidelines for orthopaedic physical therapy management of patients with musculoskeletal impairments described in the World Health Organization's International Classification of Functioning, Disability, and Health (ICF). The purpose of these clinical practice guidelines is to describe the peer-reviewed literature and make recommendations related to nonarthritic hip joint pain.

  14. Report on the FY 1999 feasibility study for the international joint research in the Asian area. 6; 1999 nendo Asia chiiki kokusai kyodo kenkyu kanosei chosa hokokusho. 6

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-03-01

    The paper surveyed the situation of the recent economic crisis, social circumstances, trends of energy policies, etc. in Asian countries. The energy consumption in Asian countries mainly including ASEAN countries and China is expected to show a large growth hereinafter together with a rapid economic growth on a long-term basis. Further, the harmony with the environmental problem has been requested. This problem is important also to Japan from a viewpoint of the regional response to the stabilized energy supply/environmental problems. The response to global environmental problems in these countries and the promotion of development/spread of new energy/energy conservation are strongly desired. For the spread of these technologies, it is effective to actually construct/operate/maintain plants under the joint research with Japan from viewpoints of personnel training, technology improvement, PR effects, etc. It is helpful also for Japan from the aspect of technology development such as data acquisition. It is necessary to accurately grasp the needs and technical levels of the other country in the case of carrying out the joint research. The survey was made about 7 countries including Thailand, Indonesia, Malaysia, the Philippines, India, China and Vietnam. (NEDO)

  15. The arbitration clause of the American International Petroleum Negotiators - AIPN; A clausula compromissoria do modelo AIPN 2002 (American International Petroleum Negotiators) para 'joint operating agreement' a luz da legislacao brasileira

    Energy Technology Data Exchange (ETDEWEB)

    Caroli, Carla [Petroleo Brasileiro S.A. (PETROBRAS), Rio de Janeiro, RJ (Brazil)

    2008-07-01

    After the Brazilian Petroleum Act (Lei n. 9.478/97) was enacted and the monopoly over the conduct of E and P activities in Brazil was made flexible, in addition to PETROBRAS, other national and foreign companies could participate in such activities. This participation of different players is increasing, specially by the formation o joint ventures constituted in order to the parties to jointly explore and produce hydrocarbons. Under these new circumstances and considering that it is important to develop efficient contractual rules to discipline the E and P operations, the 2002 AIPN Model Form for Joint Operating Agreement has been often used in Brazil. However, the effectiveness of the arbitration clause provided therein must be analyzed under the applicable law to the contract. Besides, since the operations are to be conducted in Brazil, sometimes the Brazilian Law will apply or decisions rendered by an arbitral tribunal may have to be executed in Brazil. Therefore, this paper intends to analyze how the arbitration clause provided by the 2002 AIPN Model Form may be adapted to fit the Brazilian Law. (author)

  16. Flow stress and tribology size effects in scaled down cylinder compression

    Institute of Scientific and Technical Information of China (English)

    GUO Bin; GONG Feng; WANG Chun-ju; SHAN De-bin

    2009-01-01

    Microforming is an effective method to manufacture small metal parts. However, macro forming can not be transferred to microforming directly because of size effects. Flow stress and tribology size effects were studied. Scaled down copper T2 cylinder compression was carried out with the lubrication of castor oil and without lubrication. The results show that the flow stress decreases with decreasing the initial specimen diameter in both lubrication conditions, and the flow stress decreases by 30 MPa with the initial specimen diameter decreasing from 8 mm to 1 mm. The friction factor increases obviously with decreasing the initial specimen diameter in the case of lubricating with castor oil, and the friction factor increases by 0.11 with the initial specimen diameter decreasing from 8mm to 1mm. However, the tribology size effect is not found in the case without lubrication. The reasons of the flow stress and tribology size effects were also discussed.

  17. Preparation and properties of DLC/MoS2 multilayer coatings for high humidity tribology

    Science.gov (United States)

    Zhao, Xiaoyu; Lu, Zhibin; Wu, Guizhi; Zhang, Guangan; Wang, Liping; Xue, Qunji

    2016-06-01

    The DLC/MoS2 multilayer coatings with different modulus ratios were deposited by magnetron sputtering in this study. The morphology, structure, composition, mechanical properties and tribological properties were investigated using several analytical techniques (FESEM, AFM, TEM, AES, XPS, nanoindentation and high humidity tribological test). The results showed that the well-defined multilayer coatings were composed of densely packed particles in which many nanocrystallines with some kinds of defects were distributed in matrix. The incorporation of oxygen into the lattice led to the degraded chemical stability. The coating’s hardness and elastic modulus were almost in the same range. Moderate improvement on the high humidity tribological properties were obtained, which was important for the extension of the service life of MoS2 in humid air.

  18. NSF/AFOSR/ASME Workshop on Tribology Issues and Opportunities in MEMS

    CERN Document Server

    1998-01-01

    Micro Electro Mechanical Systems (MEMS) is already about a billion dollars a year industry and is growing rapidly. So far major emphasis has been placed on the fabrication processes for various devices. There are serious issues related to tribology, mechanics, surfacechemistry and materials science in the operationand manufacturingof many MEMS devices and these issues are preventing an even faster commercialization. Very little is understood about tribology and mechanical properties on micro- to nanoscales of the materials used in the construction of MEMS devices. The MEMS community needs to be exposed to the state-of-the-artoftribology and vice versa. Fundamental understanding of friction/stiction, wear and the role of surface contamination and environmental debris in micro devices is required. There are significantadhesion, friction and wear issues in manufacturing and actual use, facing the MEMS industry. Very little is understood about the tribology of bulk silicon and polysilicon films used in the constr...

  19. Tribological performances of 3-(N, N- dialkyl dithiocarbamate-y1) propionic acids

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Three kind of water-soluble additives, 3-(N, N- dialkyl dithiocarbamate-y1) propionicacid, were synthesized. Their tribological performances when added to water were evaluated on afour-ball tester and a ring-on-block machine. Results indicate that the hydrocarbon chain length ofthese compounds has significant influence on their tribological properties. When the number ofcarbon atom in alkyl group is equal to (or more than) 4, the compounds exhibit excellentload-carrying capacity, antiwear property and weld load. The antiwear action mechanisms of thepropionic acid compounds can be ascribed to the formation of adsorption film and chemical reac-tion film. The cooperation action of these films plays an important role in the prevention of tri-bological failure.

  20. Tribological Performance of Green Lubricant Enhanced by Sulfidation IF-MoS2

    Directory of Open Access Journals (Sweden)

    Shih-Chen Shi

    2016-10-01

    Full Text Available Biopolymers reinforced with nanoparticle (NP additives are widely used in tribological applications. In this study, the effect of NP additives on the tribological properties of a green lubricant hydroxypropyl methylcellulose (HPMC composite was investigated. The IF-MoS2 NPs were prepared using the newly developed gas phase sulfidation method to form a multilayered, polyhedral structure. The number of layers and crystallinity of IF-MoS2 increased with sulfidation time and temperature. The dispersity of NPs in the HPMC was investigated using Raman and EDS mapping and showed great uniformity. The use of NPs with HPMC enhanced the tribological performance of the composites as expected. The analysis of the worn surface shows that the friction behavior of the HPMC composite with added NPs is very sensitive to the NP structure. The wear mechanisms vary with NP structure and depend on their lubricating behaviors.

  1. Identification of tribological research and development needs for lubrication of advanced heat engines

    Energy Technology Data Exchange (ETDEWEB)

    Fehrenbacher, L.L.; Levinson, T.M.

    1985-09-01

    The continuous evolution of higher power density propulsion systems has always fueled the search for materials and lubricants with improved thermal and/or durability characteristics. Tribology of the upper cylinder region is the major technology roadblock in the path of the adiabatic diesel engine which has an energy reduction potential that exceeds that of all other engine development types. This tribology assessment resulted in the following major conclusions: a low friction and a low wear seal between the ring belt and cylinder bore are the most critical tribology functions in the diesel combustion chamber; development of solid lubrication systems will not satisfy the simultaneous low friction and low wear requirements in the upper cylinder area; development of separate upper cylinder liquid lubrication systems offers the most attractive design alternative for meeting the operational goals of future ''minimum cooled'' diesel engines.

  2. Influence of tribological additives on friction and impact performance of injection moulded polyacetal

    DEFF Research Database (Denmark)

    Laursen, Jens Lolle; Sivebæk, Ion Marius; Christoffersen, L.W.

    2009-01-01

    Tribological additives are used to improve frictional properties of injection moulded thermoplastics. The additives might however also affect the mechanical properties of the material. The influence of processing conditions on both frictional and mechanical properties is highly relevant...... in the development of tribologically modified grades. In the present study we investigate how two commonly used tribological additives, polydimethylsiloxane and polytetrafluoroethylene, affect friction and impact properties of polyacetal (polyoxymethylene). A new injection mould provides test specimens for both...... surface characteristics. The tested concentration of the additives is found to effectively reduce friction, yet are not found critical with respect to the impact properties evaluated. A noticeable interaction with respect to friction is found between the additives speaking in favour of their use...

  3. The effect of processing and compositional changes on the tribology of PM212 in air

    Science.gov (United States)

    Bogdanski, Michael S.; Sliney, Harold E.; Dellacorte, Christopher

    1993-01-01

    The effects of processing and compositional variations on the tribological performance of PM212 were studied. PM212 is a self lubricating powder metallurgy composite, comprised of a wear resistant metal bonded chromium carbide matrix, containing the solid lubricants barium fluoride/calcium fluoride eutectic and silver. Several composites were formulated which had lubricant, matrix, and processing variations. Processing variations included sintering and hot isostatic pressing. Pins fabricated from the composites were slid against superalloys disks in a pin-on-disk tribometer to study the tribological properties. Several composites exhibited low friction and wear in sliding against a nickel based superalloy. The tribological performance by several different composites showed that the composition of PM212 can be altered without dramatically affecting performance.

  4. Structural, Mechanical and Tribological Properties of Spark Plasma Sintered Ti6Al4V Alloy

    Directory of Open Access Journals (Sweden)

    Mróz A.

    2016-06-01

    Full Text Available The influence of spark plasma sintering parameters on the structural, mechanical and tribological characteristics of the Ti6Al4V alloy, which is used as implant material in biomedical engineering, was investigated. The experimental data confirm that full density and attractive mechanical properties can be obtained using the spark plasma sintering method. Tribological tests, performed in dry conditions, allowed the authors to indicate the most suitable sintering parameters. The material characterized by the highest wear resistance was selected for further tribological testing in articulation with UHMWPE in simulated body fluids. Although the weight of the polymeric material articulating against the sintered Ti6Al4V was slightly higher compared to the UHMWPE articulating against the reference material (Ti6Al4V rod, the friction coefficient was lower.

  5. Synthesis and Tribological Properties of WSe2Nanorods

    Directory of Open Access Journals (Sweden)

    Yang Jinghai

    2008-01-01

    Full Text Available Abstract The WSe2nanorods were synthesized via solid-state reaction method and characterized by X-ray diffractometer, TEM, and HRTEM. The results indicated the WSe2compounds had rod-like structures with diameters of 10–50 nm and lengths of 100–400 nm, and the growth process of WSe2nanorods was discussed on the basis of the experimental facts. The tribological properties of WSe2nanorods as additives in HVI500 base oil were investigated by UMT-2 multispecimen tribotester. Under the determinate conditions, the friction coefficient of the base oil containing WSe2nanorods was lower than that of the base oil, and decreased with increasing mass fraction of WSe2nanorods when it was <7 wt.%. Moreover, the base oil with the additives was rather suited to high load and high rotating speed. A combination of rolling friction, sliding friction, and stable tribofilm on the rubbing surface could explain the good friction and wear properties of WSe2nanorods as additives.

  6. Tribological Properties of Biodegradable Universal Tractor Transmission Oil

    Directory of Open Access Journals (Sweden)

    M. Stojilković

    2016-06-01

    Full Text Available The annual consumption of lubricants in the world is around 40 million tons out of which less than 40 % are collected and properly processed meaning regeneration, re-refining and controlled incineration while the rest is disposed without control thus contaminating soil, water and atmosphere. It's one of the reasons that the last twenty years the environmentally friendly lubricants are more and more used. For the production of environmentally friendly lubricants are mostly used vegetable oil. In the field of the application of environmentally friendly lubricants attention should be given to the technical requirements including protection from the wear, corrosion protection, high load carrying properties and fulfilment of all the requirements imposed by the producer of the mechanical system. This paper presents development and testing of the biodegradable universal tractor transmission oil (UTTO based on the vegetable oils. Tribological properties of the oils based on rapes oil, sunflower and soya, after corresponding testing, compared with the features of the commercially available mineral universal tractor transmission oil.

  7. TRIBOLOGICAL STUDIES ON GRAPHENE/TMP BASED NANOLUBRICANT

    Directory of Open Access Journals (Sweden)

    RASHMI W.

    2017-02-01

    Full Text Available This paper presents studies on density, dynamic viscosity and tribological behaviour of nano graphene platelets (NGPs dispersed in Palm Oil Trimethlolpropane (TMP ester base lubricant. NGPs with concentrations ranging from 0.01 to 0.1 wt% are dispersed in the TMP ester via water bath sonication for 4 hours to form stable NGP nanolubricants. Physical properties such as density and viscosity was measured using Portable density meter and Brookfield viscosmeter (DV II+. No significant enhancement in density was observed, while a maximum enhancement on viscosity was 168% at 0.1 wt % NGPs concentration. The evaluation of frictional coefficient was performed using a four ball test at varying loads, from 40 kg to 80 kg, respectively. Results showed that the introduction of NGPs as an additive in the TMP lubricant reduced the coefficient of friction (COF in NGP-Palm oil TMP Ester, achieving a maximum reduction of 7%, and 16.2% in the wear scar diameter at 0.05wt% NGP and 80 kg load. It was observed that addition of NGP has prevented oxidative attacks on the surface of the steel balls through the development of a sturdier lubricating film barrier between nanolubricant and the solid surfaces.

  8. Preparation of tungsten disulfide motor oil and its tribological characteristics

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Through using mineral oil and synthetic oil to deploy the semisynthesis base oil, modifying the surfaces of ultrafine tungsten disulfide grains by surface chemical embellishment and adsorption embellishment to make them suspended steadily in the base oil as solid lubricating additive, and adding some function additives, the tungsten disulfide motor oil was prepared. The tribological characteristics of this kind motor oil and the well-known motor oils in our country and overseas were studied. The results show that the oil film strength of this kind of motor oil is respectively 1.06 and 1.38 times of that of shell helix ultra motor oil and great wall motor oil, and its sintering load is 1.75 and 2.33 times of that of them, and when tested under 392 N, 1 450 r/min and 30 min, the friction coefficients of friction pairs lubricated by the tungsten disulfide motor oil decrease with the increase of time, meanwhile, the diameter of worn spot is small, and the surface of worn spot is smooth, and no obvious furrows appear. The experiments indicate that the tungsten disulfide motor oil has the better antiwear, antifriction and extreme pressure properties than the well-known motor oils.

  9. Tribological behavior of hot-pressed boron carbide with oxidation

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The oxidation behavior at 973-1 273 K and the effect of oxidation on the room-temperature tribological properties of hot-pressed boron carbide ceramic were investigated. Oxidized samples were studied by X-ray diffractometer and scanning electron microscopy. It is demonstrated that the oxidation results in the formation of a thin transparent B2O3 film, and the oxide film is severely cracked during cooling due to the thermal expansion mismatch between the oxide film and B4C substrate. B2O3 reacts with moisture in air to form boric acid, which is a kind of solid lubricant. The sliding friction factors of oxidized B4C pair are about 0.05-0.08, compared to 0.25-0.35 of the as-received B4C pair. When the oxidation temperature is up to 1 273 K, severe unstability and increase of friction factor are observed. Visual inspection of the wear track reveals that the lubricant film is broken and some debris particles occur on and around the rubbing surfaces, because the friction interface is rough by the severe etching of grain boundaries.

  10. Synthesis and tribological properties of antimony N, N-diethanoldithiocarbamate

    Institute of Scientific and Technical Information of China (English)

    李丽; 黄可龙; 瞿龙; 舒万艮

    2001-01-01

    Antimony N, N-diethanoldithiocarbamate was synthesized with diethanolamine, antimony trioxide and carbon disulfide. The influences of temperature, reaction time, solvents and their dosages were investigated, and the optimum synthesis conditions were: reaction temperature 15~20 ℃, reaction time 2.5 h, 250 mL CH3OH as solvent and the hot CH3OH as recrystallization solvent. Element analysis, IR, 1HNMR and 13CNMR spectra were used to study its chemical composition and molecular structure. Antimony N, N-diethanol-dithiocarbamate was added in the base oil, and its properties of wear resistance and extreme pressure were studied by FB, FD and WSD. The synthesis product behaves per fectly as wear resistance and extreme pressure additive and its extreme pressure property is superior to its wear resistance property. The mechanism of tribological action was discussed by using XPS and AES spectra, and the reason of good wear resistance and extreme pressure properties is that the synthesis product decompose element C, S and N.

  11. Tribological Behaviour of the Ceramic Coating Formed on Magnesium Alloy

    Institute of Scientific and Technical Information of China (English)

    CHEN Fei; ZHOU Hai; CHEN Qiang; GE Yuanjing; LV Fanxiu

    2007-01-01

    Micro-arc oxidation is a recently developed surface treatment technology under anodic oxidation. Through micro-arc oxidation, a ceramic coating is directly formed on the surface of magnesium alloy, by which its surface property is significantly improved. In this paper, a dense ceramic oxide coating was prepared on an AZ31 magnesium alloy by micro-arc oxidation in a NaOH-Na2SiO3-NaB4O7-(NaPO3)6 electrolytic solution. Micro-structure, surface morphology and phase composition were analysed using scanning electron microscopy (SEM) and X-ray diffraction (XRD). The tribological behavior of the micro-arc oxidation ceramic coating under dry sliding against GCrl5 steel was evaluated on a ball-on-disc test rig. The results showed that the AZ31 alloy was characterized by adhesion wear and scuffing under dry sliding against the steel, while the surface micro-arc oxidation ceramic coating experienced much abated adhesion wear and scuffing under the same testing conditions. The micro-arc oxidation ceramic coating showed good friction-reducing and fair antiwear ability in dry sliding against the steel.

  12. Fault tree analysis of most common rolling bearing tribological failures

    Science.gov (United States)

    Vencl, Aleksandar; Gašić, Vlada; Stojanović, Blaža

    2017-02-01

    Wear as a tribological process has a major influence on the reliability and life of rolling bearings. Field examinations of bearing failures due to wear indicate possible causes and point to the necessary measurements for wear reduction or elimination. Wear itself is a very complex process initiated by the action of different mechanisms, and can be manifested by different wear types which are often related. However, the dominant type of wear can be approximately determined. The paper presents the classification of most common bearing damages according to the dominant wear type, i.e. abrasive wear, adhesive wear, surface fatigue wear, erosive wear, fretting wear and corrosive wear. The wear types are correlated with the terms used in ISO 15243 standard. Each wear type is illustrated with an appropriate photograph, and for each wear type, appropriate description of causes and manifestations is presented. Possible causes of rolling bearing failure are used for the fault tree analysis (FTA). It was performed to determine the root causes for bearing failures. The constructed fault tree diagram for rolling bearing failure can be useful tool for maintenance engineers.

  13. Femtosecond laser ablation of cemented carbides: properties and tribological applications

    Science.gov (United States)

    Dumitru, G.; Romano, V.; Weber, H. P.; Gerbig, Y.; Haefke, H.; Bruneau, S.; Hermann, J.; Sentis, M.

    Laser ablation with fs laser pulses was performed in air on cobalt cemented tungsten carbide by means of a Ti : sapphire laser (800 nm, 100 fs). Small and moderate fluences (2, 5, 10 J/cm2) and up to 5×104 pulses per irradiated spot were used to drill holes with aspect ratios up to 10. Cross-section cuts from laser-irradiated samples were produced and they were analysed with optical microscopy and SEM. EDX analyses were carried out on selected zones. Quasi-cylindrical holes were found for 2 J/cm2, whereas for 5 and 10 J/cm2 irregular shapes (lobes, bottoms wider than hole entrances) were found to occur after a given number of incident pulses. Layers with modified structure were evidenced at pore walls. SEM revealed a denser structure, while EDX analyses showed uniform and almost similar contents of W, C, and Co in these layers. As a direct application, patterning of coated WC-Co was carried out with 2 J/cm2 and 100 pulses per pore. The resulted surfaces were tribologically tested and these tests revealed an improved friction and wear behaviour.

  14. Ion-Implanted Diamond Films and Their Tribological Properties

    Science.gov (United States)

    Wu, Richard L. C.; Miyoshi, Kazuhisa; Korenyi-Both, Andras L.; Garscadden, Alan; Barnes, Paul N.

    1993-01-01

    This paper reports the physical characterization and tribological evaluation of ion-implanted diamond films. Diamond films were produced by microwave plasma, chemical vapor deposition technique. Diamond films with various grain sizes (0.3 and 3 microns) and roughness (9.1 and 92.1 nm r.m.s. respectively) were implanted with C(+) (m/e = 12) at an ion energy of 160 eV and a fluence of 6.72 x 10(exp 17) ions/sq cm. Unidirectional sliding friction experiments were conducted in ultrahigh vacuum (6.6 x 10(exp -7)Pa), dry nitrogen and humid air (40% RH) environments. The effects of C(+) ion bombardment on fine and coarse-grained diamond films are as follows: the surface morphology of the diamond films did not change; the surface roughness increased (16.3 and 135.3 nm r.m.s.); the diamond structures were damaged and formed a thin layer of amorphous non-diamond carbon; the friction coefficients dramatically decreased in the ultrahigh vacuum (0.1 and 0.4); the friction coefficients decreased slightly in the dry nitrogen and humid air environments.

  15. TRIBOLOGICAL PROPERTIES OF CrAgN THIN FILMS

    Directory of Open Access Journals (Sweden)

    Peter Jurči

    2013-04-01

    Full Text Available CrN and CrAgN thin films were magnetron sputtered onto the substrate made from Vanadis 6 cold work tool steel. The films were examined on tribological properties using a high temperature Pin-on-disc tribometer. Obtained results show that there is almost no effect of Ag addition on the friction coefficient when tested at a room temperature against alumina. The testing against the same counterpart at higher temperature gave positive effect of the silver addition on the friction coefficient. The testing against 100Cr6 ball bearing steel gave higher friction coefficient than that against alumina while the testing against CuSn6-bronze led to much lower μ. When tested at a room temperature, the wear performance of the films was positively affected only in the case of the CrAg3N film developed at 500 °C. On the other hand, addition of 3 wt% Ag into the CrN increased the wear performance at elevated temperatures while the addition of 15 wt% Ag has made the film too soft and sensitive to wear.

  16. Tribological properties of CrAgN thin films

    Directory of Open Access Journals (Sweden)

    Peter Jurči

    2013-02-01

    Full Text Available CrN and CrAgN thin films were magnetron sputtered onto the substrate made from Vanadis 6 cold work tool steel. The films were examined on tribological properties using a high temperature Pin-on-disc tribometer. Obtained results show that there is almost no effect of Ag addition on the friction coefficient when tested at a room temperature against alumina. The testing against the same counterpart at higher temperature gave positive effect of the silver addition on the m. The testing against 100Cr6 ball bearing steel gave higher friction coefficient than that against alumina while the testing against CuSn6-bronze led to much lower m. When tested at a room temperature, the wear performance of the films was positively affected only in the case of the CrAg3N film developed at 500 oC. On the other hand, addition of 3 wt% Ag into the CrN increased the wear performance at elevated temperatures while the addition of 15 wt% Ag has made the film too soft and sensitive to wear.

  17. Vacuum tribological behaviour of self lubricant quasicrystalline composite coatings

    Science.gov (United States)

    Garcí de Blas, F. J.; Román, A.; de Miguel, C.; Longo, F.; Muelas, R.; Agüero, A.

    2003-09-01

    High temperature resistant self-lubricant coatings are needed in space vehicles for components that operate at high temperatures and/or under vacuum. Thick composite lubricant coatings containing quasicrystalline alloys (QC) as the hard phase for wear resistance, have been deposited by thermal spray. The coatings also comprise lubricating materials (silver and BaF2-CaF2 eutectic) and NiCr as the tough component. This paper describes the vacuum tribological properties of TH103, a coating belonging to this family, with excellent microstructural quality. The coating was deposited by HVOF and tested under vacuum on a pin-on-disc tribometer. Different loads, linear speeds and pin materials were studied. The pin scars and disc wear tracks were characterized by EDS-SEM. A minimum mean steady friction coefficient of 0.32 was obtained employing a X-750 Ni superalloy pin in vacuum conditions under 10 N load and 15 cm/s linear speed, showing moderate wear of the disc and low wear of the pin.

  18. Fabrication and tribological properties of Al reinforced with carbon fibers

    Directory of Open Access Journals (Sweden)

    Estrems Amestoy, Manuel

    2000-10-01

    Full Text Available The present work studies the manufacturing process of Al reinforced with Carbon Fibres (CF by "Squeeze Casting", establishing the variables for obtaining an acceptable product with little Al4C3 at the interface. Friction and wear tests are performed and the necessary conditions for the formation of a tribofilm are established. The tests show an increasing resistance to abrasion due to their own wear mechanism. Certain design criteria for those components subjected to friction are recommended in order to maximise the mechanical performance of the tribological system.

    Este trabajo estudia el proceso de fabricación de composites Al reforzado con fibras de carbono mediante la técnica ''Squeeze Casting'', estableciendo las variables para obtener un producto aceptable que tenga poca cantidad de Al4C3 en la interfase. Se han realizado ensayos de fricción y desgaste y se han establecido las condiciones necesarias para la formación de la tribocapa. Se muestra la alta capacidad de resistencia a la abrasión de las piezas producidas debido a su propio mecanismo de desgaste y se recomiendan ciertos criterios de diseño para componentes mecánicos con el fin de optimizar las prestaciones mecánicas en un sistema tribológico.

  19. Tribological Properties of Nano-dimensional Systems Containing Carbon Surfaces

    Directory of Open Access Journals (Sweden)

    A.V. Khomenko

    2014-04-01

    Full Text Available We review tribological properties of boundary films of hydrocarbons and water confined between atomically smooth and rough surfaces. Both theory and experiment show that ultrathin film of liquid with thickness less than six molecular diameters restricted in small volumes is solid-like. Such a state is characterized by the decrease of mobility of molecules related to the increase of relaxation times and decrease of the diffusion coefficient. Additionally, quasidiscrete layers of molecules appear and in-plane ordering of the layers occurs. Atomic-scale roughness of the walls destroys the order of the molecules. We also describe experimental studies of friction of graphite at the atomic level. The experiments suggest a principal possibility of superlubricity for the tungsten tip of friction force microscope sheared on the surface of graphite. A possible explanation of this phenomenon consists in the existence of the graphite nanoflake attached to the tip. However, reliable confirmation of this hypothesis is absent in the literature. We also review methods of the graphene preparation through exfoliation of a graphite sample and formation of defects in graphene as a result of its irradiation by different particles. We describe the experimental method of measurement of friction of metallic nanoparticles sliding on the surface of graphite. We consider basic advantages of this approach compared to the known methods and friction duality in these systems. The review indicates the necessity of further comprehensive theoretical study of friction of metallic nanoparticles adsorbed on atomically smooth surfaces.

  20. Mechanisms underlying astringency: introduction to an oral tribology approach

    Science.gov (United States)

    Upadhyay, Rutuja; Brossard, Natalia; Chen, Jianshe

    2016-03-01

    Astringency is one of the predominant factors in the sensory experience of many foods and beverages ranging from wine to nuts. The scientific community is discussing mechanisms that explain this complex phenomenon, since there are no conclusive results which correlate well with sensory astringency. Therefore, the mechanisms and perceptual characteristics of astringency warrant further discussion and investigation. This paper gives a brief introduction of the fundamentals of oral tribology forming a basis of the astringency mechanism. It discusses the current state of the literature on mechanisms underlying astringency describing the existing astringency models. The review discusses the crucial role of saliva and its physiology which contributes significantly in astringency perception in the mouth. It also provides an overview of research concerned with the physiological and psychophysical factors that mediate the perception of this sensation, establishing the ground for future research. Thus, the overall aim of the review is to establish the critical roles of oral friction (thin-film lubrication) in the sensation of astringency and possibly of some other specific sensory features.

  1. Radiographic evaluation of cervical spine of subjects with temporomandibular joint internal disorder Avaliação radiográfica da coluna cervical de indivíduos com distúrbios internos da articulação temporomandibular

    OpenAIRE

    2004-01-01

    Although the etiopathophysiology of internal temporomandibular joint internal disorders (TMJ ID) is still unknown, it has been suggested that head and body posture could be related to its initial onset, development and perpetuation. The purpose of the present study was to observe the relationship between cervical spine X-ray abnormalities and TMJ ID. This investigation evaluated 30 subjects with internal TMJ disorder symptoms (test group) and 20 healthy subjects (control group). Subjects were...

  2. Surface Texturing-Plasma Nitriding Duplex Treatment for Improving Tribological Performance of AISI 316 Stainless Steel

    Directory of Open Access Journals (Sweden)

    Naiming Lin

    2016-10-01

    Full Text Available Surface texturing-plasma nitriding duplex treatment was conducted on AISI 316 stainless steel to improve its tribological performance. Tribological behaviors of ground 316 substrates, plasma-nitrided 316 (PN-316, surface-textured 316 (ST-316, and duplex-treated 316 (DT-316 in air and under grease lubrication were investigated using a pin-on-disc rotary tribometer against counterparts of high carbon chromium bearing steel GCr15 and silicon nitride Si3N4 balls. The variations in friction coefficient, mass loss, and worn trace morphology of the tested samples were systemically investigated and analyzed. The results showed that a textured surface was formed on 316 after electrochemical processing in a 15 wt % NaCl solution. Grooves and dimples were found on the textured surface. As plasma nitriding was conducted on a 316 substrate and ST-316, continuous and uniform nitriding layers were successfully fabricated on the surfaces of the 316 substrate and ST-316. Both of the obtained nitriding layers presented thickness values of more than 30 μm. The nitriding layers were composed of iron nitrides and chromium nitride. The 316 substrate and ST-316 received improved surface hardness after plasma nitriding. When the tribological tests were carried out under dry sliding and grease lubrication conditions, the tested samples showed different tribological behaviors. As expected, the DT-316 samples revealed the most promising tribological properties, reflected by the lowest mass loss and worn morphologies. The DT-316 received the slightest damage, and its excellent tribological performance was attributed to the following aspects: firstly, the nitriding layer had high surface hardness; secondly, the surface texture was able to capture wear debris, store up grease, and then provide continuous lubrication.

  3. Tribological performance of sub-100-nm femtosecond laser-induced periodic surface structures on titanium

    Energy Technology Data Exchange (ETDEWEB)

    Bonse, J., E-mail: joern.bonse@bam.de [BAM Bundesanstalt für Materialforschung und -prüfung, Unter den Eichen 87, D-12205 Berlin (Germany); Höhm, S. [Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie (MBI), Max-Born-Straße 2A, D-12489 Berlin (Germany); Koter, R.; Hartelt, M.; Spaltmann, D.; Pentzien, S. [BAM Bundesanstalt für Materialforschung und -prüfung, Unter den Eichen 87, D-12205 Berlin (Germany); Rosenfeld, A. [Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie (MBI), Max-Born-Straße 2A, D-12489 Berlin (Germany); Krüger, J. [BAM Bundesanstalt für Materialforschung und -prüfung, Unter den Eichen 87, D-12205 Berlin (Germany)

    2016-06-30

    Graphical abstract: - Highlights: • Large areas covered with sub-100 nm LIPSS (HSFL) were manufactured by fs-laser irradiation on titanium surfaces. • Tribological performance of HSFL covered areas was qualified in reciprocal sliding tests in two different lubricating oils. • HSFL on titanium do not endure the tribological tests. • For a beneficial tribological performance, the tribological sample deformation must be smaller than the LIPSS modulation depth. - Abstract: Sub-100-nm laser-induced periodic surface structures (LIPSS) were processed on bulk titanium (Ti) surfaces by femtosecond laser pulse irradiation in air (30 fs pulse duration, 790 nm wavelength). The laser peak fluence, the spatial spot overlap, and the number of overscans were optimized in a sample-scanning geometry in order to obtain large surface areas (5 mm × 5 mm) covered homogeneously by the LIPSS. The laser-processed regions were characterized by optical microscopy (OM), white light interference microscopy (WLIM) and scanning electron microscopy (SEM). The friction coefficient of the nanostructured surfaces was tested during 1000 cycles under reciprocal sliding conditions (1 Hz, 1.0 N normal load) against a 10-mm diameter ball of hardened 100Cr6 steel, both in paraffin oil and in engine oil used as lubricants. Subsequently, the corresponding wear tracks were qualified by OM, SEM, and energy dispersive X-ray analyses (EDX). The results of the tribological tests are discussed and compared to that obtained for near wavelength-sized fs-LIPSS, processed under somewhat different irradiation conditions. Some constraints for a beneficial effect of LIPSS on the tribological performance are provided.

  4. Surface Texturing-Plasma Nitriding Duplex Treatment for Improving Tribological Performance of AISI 316 Stainless Steel.

    Science.gov (United States)

    Lin, Naiming; Liu, Qiang; Zou, Jiaojuan; Guo, Junwen; Li, Dali; Yuan, Shuo; Ma, Yong; Wang, Zhenxia; Wang, Zhihua; Tang, Bin

    2016-10-27

    Surface texturing-plasma nitriding duplex treatment was conducted on AISI 316 stainless steel to improve its tribological performance. Tribological behaviors of ground 316 substrates, plasma-nitrided 316 (PN-316), surface-textured 316 (ST-316), and duplex-treated 316 (DT-316) in air and under grease lubrication were investigated using a pin-on-disc rotary tribometer against counterparts of high carbon chromium bearing steel GCr15 and silicon nitride Si₃N₄ balls. The variations in friction coefficient, mass loss, and worn trace morphology of the tested samples were systemically investigated and analyzed. The results showed that a textured surface was formed on 316 after electrochemical processing in a 15 wt % NaCl solution. Grooves and dimples were found on the textured surface. As plasma nitriding was conducted on a 316 substrate and ST-316, continuous and uniform nitriding layers were successfully fabricated on the surfaces of the 316 substrate and ST-316. Both of the obtained nitriding layers presented thickness values of more than 30 μm. The nitriding layers were composed of iron nitrides and chromium nitride. The 316 substrate and ST-316 received improved surface hardness after plasma nitriding. When the tribological tests were carried out under dry sliding and grease lubrication conditions, the tested samples showed different tribological behaviors. As expected, the DT-316 samples revealed the most promising tribological properties, reflected by the lowest mass loss and worn morphologies. The DT-316 received the slightest damage, and its excellent tribological performance was attributed to the following aspects: firstly, the nitriding layer had high surface hardness; secondly, the surface texture was able to capture wear debris, store up grease, and then provide continuous lubrication.

  5. 经皮克氏针内固定结合术后康复训练治疗Bennett骨折对关节功能恢复的观察%Internal fixation with Kirschner pins in combination of postoperative trainig recovering joint function following Bennett fracture

    Institute of Scientific and Technical Information of China (English)

    查天文; 聂梅

    2002-01-01

    Background:Bennett fracture belongs to intraarticular injury.Conventionally,external fixation with splint or plaster failures to maintain postrepair position,leading to fracture and translocation.On the other hand,longer term outer fixation will result in joint stiffness.Internal fixation with Kirschner pins in combination of postoperative training was characterized by stable fixation,less injury,allow early functional exercise and is beneficial to recovery of joint function.

  6. IRS memorandum limits joint ventures.

    Science.gov (United States)

    Herman, A W

    1992-08-01

    Based on a new memorandum, the Internal Revenue Service (IRS) will be looking at joint hospital/physician activities with greater attention to the nuances of public versus private benefit. As a result, hospitals face greater risk of losing their tax-exempt status in the maze of joint ventures, physician recruitment, and practice acquisition. To be successful, ventures will have to be backed by sound reasoning and thorough documentation.

  7. Tribological development of TiCN coatings by adjusting the flowing rate of reactive gases

    Science.gov (United States)

    Tillmann, Wolfgang; Momeni, Soroush

    2016-03-01

    TiCN coatings were deposited by means of direct current magnetron sputtering of Ti targets in presence of N2 and C2H2 reactive gases. The microstructure, composition, mechanical and tribological properties of the deposited thin films were analyzed by using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), nanoindentation, ball-on-disc, scratch test, and three dimensional (3D) optical microscopy. The obtained results presents a reproducible processing route for tailoring microstructure, mechanical and tribological behavior of TiCN coatings by controlling flowing rate of the reactive gases.

  8. Tribological study in roll forming of lean duplex stainless steel sheets

    DEFF Research Database (Denmark)

    Nielsen, Peter Søe; Nielsen, Morten Strogaard; Bay, Niels

    2012-01-01

    focus on tribological issues are galling and pick-up formation as well as tool life in roll forming of stainless duplex steel sheets. The roll forming process is exemplified by production of an s-shaped profile used in interlock carcass production for flexible pipes used in off-shore oil extraction...... are relatively low and surface expansion is more or less non-existent, long roll forming production runs imply large sliding/contact lengths due to relative movement between steel strip and rolls. This requires an efficient tribological system to prevent pick-up formation on the forming tools. The present work...

  9. Characterization and Tribological Properties of Hard Anodized and Micro Arc Oxidized 5754 Quality Aluminum Alloy

    Directory of Open Access Journals (Sweden)

    M. Ovundur

    2015-03-01

    Full Text Available This study was initiated to compare the tribological performances of a 5754 quality aluminum alloy after hard anodic oxidation and micro arc oxidation processes. The structural analyses of the coatings were performed using XRD and SEM techniques. The hardness of the coatings was determined using a Vickers micro-indentation tester. Tribological performances of the hard anodized and micro arc oxidized samples were compared on a reciprocating wear tester under dry sliding conditions. The dry sliding wear tests showed that the wear resistance of the oxide coating generated by micro arc oxidation is remarkably higher than that of the hard anodized alloy.

  10. Physical, mechanical, and tribological properties of quasicrystalline Al-Cu-Fe coatings prepared by plasma spraying

    Science.gov (United States)

    Lepeshev, A. A.; Rozhkova, E. A.; Karpov, I. V.; Ushakov, A. V.; Fedorov, L. Yu.

    2013-12-01

    The physical, mechanical, and tribological properties of quasicrystalline coatings based on the Al65Cu23Fe12 alloy prepared by plasma spraying have been investigated. The specific features of the phase formation due to the competitive interactions of the icosahedral ψ and cubic β phases have been elucidated. A correlation between the microhardness and the content of the icosahedral phase in the coating has been determined. The decisive role of the quasicrystalline phase in the formation of high tribological characteristics of the coatings has been revealed and tested.

  11. The application of tribology in assessing texture perception of oral liquid medicines.

    Science.gov (United States)

    Batchelor, Hannah; Venables, Rebecca; Marriott, John; Mills, Tom

    2015-02-20

    The palatability of medicines is likely to have a significant impact on patient adherence and consequently, on the safety and efficacy of a medicinal product. Palatability encompasses properties of medicines not limited to taste including swallowability (e.g. size, shape, texture). However, there has been limited work undertaken to measure the texture of medicines and how this may affect palatability and subsequent adherence. Tribology offers an understanding of oral processes and can allow physical properties of materials to be linked to "mouthfeel". This paper describes a preliminary application of tribology to oral liquid medicines and demonstrates that this technique is useful in the development of future oral liquid medicines.

  12. The adhesion solidity, physico-mechanical and tribological properties of the coating of titanium nitride

    Science.gov (United States)

    Krivina, L. A.; Tarasenko, Yu P.; Fel, Ya A.

    2017-05-01

    Influence of variable technological factors (arch current, fractional pressure of gas in the camera) on structure, physic-mechanical and tribological features of an ion-plasma coating of titanium nitride has been investigated. The adhesion solidity has been put to the test and the mechanism of destruction of a covering has been also researched by a skretch-test method. The optimal mode of spraying at which the formation of the nanostructured bar coating of TiN has been defined. The covering offers an optimal combination of physic-mechanical, tribological and solidity features.

  13. Studies of welded joints

    Directory of Open Access Journals (Sweden)

    J. M. Krupa

    2010-07-01

    Full Text Available Studies of a welded joint were described. The joint was made as a result of the reconstruction of a truss and one of the possible means to make a repair. The studies were of a simulation character and were targeted at the detection of welding defects and imperfections thatshould be eliminated in a real structure. A model was designed and on this model the tests and examinations were carried out. The modelwas made under the same conditions as the conditions adopted for repair. It corresponded to the real object in shape and dimensions, and in the proposed technique of welding and welding parameters. The model was composed of five plates joined together with twelve beads.The destructive and non-destructive tests were carried out; the whole structure and the respective welds were also examined visually. Thedefects and imperfections in welds were detected by surface methods of inspection, penetration tests and magnetic particle flaw detection.The model of the welded joint was prepared by destructive methods, a technique that would never be permitted in the case of a realstructure. For the investigations it was necessary to cut out the specimens from the welded joint in direction transverse to the weld run. The specimens were subjected to metallographic examinations and hardness measurements. Additionally, the joint cross-section was examined by destructive testing methods to enable precise determination of the internal defects and imperfections. The surface methods were applied again, this time to determine the severity of welding defects. The analysis has proved that, fabricated under proper conditions and with parameters of the welding process duly observed, the welded joint has good properties and repairs of this type are possible in practice.

  14. Uncertainty of knee joint muscle activity during knee joint torque exertion: the significance of controlling adjacent joint torque.

    Science.gov (United States)

    Nozaki, Daichi; Nakazawa, Kimitaka; Akai, Masami

    2005-09-01

    In the single-joint torque exertion task, which has been widely used to control muscle activity, only the relevant joint torque is specified. However, the neglect of the neighboring joint could make the procedure unreliable, considering our previous result that even monoarticular muscle activity level is indefinite without specifying the adjacent joint torque. Here we examined the amount of hip joint torque generated with knee joint torque and its influence on the activity of the knee joint muscles. Twelve healthy subjects were requested to exert various levels of isometric knee joint torque. The knee and hip joint torques were obtained by using a custom-made device. Because no information about hip joint torque was provided to the subjects, the hip joint torque measured here was a secondary one associated with the task. The amount of hip joint torque varied among subjects, indicating that they adopted various strategies to achieve the task. In some subjects, there was a considerable internal variability in the hip joint torque. Such variability was not negligible, because the knee joint muscle activity level with respect to the knee joint torque, as quantified by surface electromyography (EMG), changed significantly when the subjects were requested to change the strategy. This change occurred in a very systematic manner: in the case of the knee extension, as the hip flexion torque was larger, the activity of mono- and biarticular knee extensors decreased and increased, respectively. These results indicate that the conventional single knee joint torque exertion has the drawback that the intersubject and/or intertrial variability is inevitable in the relative contribution among mono- and biarticular muscles because of the uncertainty of the hip joint torque. We discuss that the viewpoint that both joint torques need to be considered will bring insights into various controversial problems such as the shape of the EMG-force relationship, neural factors that help

  15. T形、Y形带内置环肋圆钢管相贯节点承载力计算方法%Calculation method for bearing capacities of internal ring-stiffened tubular T-and Y-joints

    Institute of Scientific and Technical Information of China (English)

    王帆; 陈志进; 刘丁丁; 罗敏; 宁晨; 蓝小艺

    2014-01-01

    为了得到T形、Y形带内置环肋圆钢管相贯节点的承载力计算公式,对528个节点进行参数化分析.结果表明:T形、Y形节点的环肋设置在冠点时,对节点承载力提高率的贡献最小,而设置在距冠点到鞍点距离的0.7~0.8倍时,贡献最大;支管受压时,T形带肋节点承载力提高值随环肋厚度和宽度的增大而增大,但受支主管直径比和主管径厚比的影响较小;T形、Y形带肋节点承载力提高值之比受支主管直径比和环肋厚度、宽度的影响较小,而随支主管夹角的增大呈近似线性增加;考虑主管应力比以及支管拉力的影响时,可沿用现行规范中无肋节点的相关参数.结合现行规范,提出了T形和Y形节点的承载力计算公式,适用性检验结果证明了所提公式的可靠性.%In order to obtain calculation equations for the bearing capacities of internal ring-stiffened tubular T-and Y-joints,parametric analysis for 528 tubular joints is carried out.The results show that for T-and Y-joints,the smallest increase in joints’ bearing capacity occurs when the stiffeners are lo-cated on the crown,while the increases are highest when the stiffeners are located 0.7 to 0.8 times of the distance between the crown and the saddle from the crown.When the brace is under compres-sion,the ring-stiffened T-joints’ bearing capacity increases with the increase of the thickness and the width of the ring-stiffeners,and the effects of the ratio of brace diameter to chord diameter and the ratio of chord diameter to chord thickness are insignificant.The ratio of the increase of the bearing capacity of T-joints to that of Y-joints linearly increases with the increase of the angle between the brace and the chord,and the ratio of brace diameter to chord diameter, as well as the thickness and the width of ring-stiffeners are less effective.The related parameters of the unstiffened joints in exist-ing codes can be

  16. Preparation and tribological properties of fluorosilane surface-modified lanthanum trifluoride nanoparticles as additive of fluoro silicone oil

    Energy Technology Data Exchange (ETDEWEB)

    Hou, Xiao [Key Laboratory of Ministry of Education for Special Functional Materials, Henan University, Kaifeng 475004 (China); He, Jie [School of Life Science, Henan University, Kaifeng 475004 (China); Yu, Laigui [Key Laboratory of Ministry of Education for Special Functional Materials, Henan University, Kaifeng 475004 (China); Li, Zhiwei, E-mail: zhiweili@henu.edu.cn [Key Laboratory of Ministry of Education for Special Functional Materials, Henan University, Kaifeng 475004 (China); Zhang, Zhijun; Zhang, Pingyu [Key Laboratory of Ministry of Education for Special Functional Materials, Henan University, Kaifeng 475004 (China)

    2014-10-15

    Highlights: • Fluorosilane was selected as the modifier according to similar miscibility principle. • Fluorosilane surface-modified LaF{sub 3} nanoparticles were successfully prepared. • Fluorosilane can enhance dispersibility of LaF{sub 3} nanoparticles in fluorosilicone oils. • Fluorosilane can improve the stability of LaF{sub 3} nanoparticles. • LaF{sub 3} nanoparticles prove excellent anti-wear and friction-reducing capacities. - Abstract: LaF{sub 3} nanoparticles surface-modified with fluorosilane were synthesized by surface modification technology. The size, morphology and phase structure of as-prepared surface-modified LaF{sub 3} nanoparticles were analyzed by means of X-ray diffraction and transmission electron microscopy. The tribological properties of surface-modified LaF{sub 3} nanoparticles as additive of fluoro silicone oil were evaluated with a four-ball machine, and the morphology and elemental composition of worn steel surfaces were examined with a scanning electron microscope and an X-ray photoelectron spectroscope. Results show that 3-(heptafluoroisopropoxy)propyltriethoxysilane as the modifier is able to improve the dispersibility of LaF{sub 3} nanoparticles in fluoro silicone oil. Moreover, when the optimum concentration, 0.08 wt.% of fluorosilane surface-modified LaF{sub 3} is added into fluoro silicone oil, as-synthesized fluorosilane surface-modified LaF{sub 3} nanoparticles exhibit excellent anti-wear as additive in fluoro silicone oil. The wear scar diameter under the optimum concentration is always smaller than that under the lubrication of fluoro silicone oil alone. Especially, when the load is 500 N, 600 N and 700 N, the wear scar diameter is reduced by 17%, 43% and 42%, respectively. In addition, during the friction process, LaF{sub 3} nanoparticles are deposited on the rubbed steel surface to form LaF{sub 3} deposition layer which functions jointly with the boundary lubricating film thereby resulting in improved tribological

  17. Joint purpose?

    DEFF Research Database (Denmark)

    Pristed Nielsen, Helene

    2013-01-01

    Starting from Crenshaw´s point that antiracism often fails to interrogate patriarchy and that feminism often reproduces racist practices (1991: 1252), this paper asks: What are the theoretical reasons for believing that feminism and anti-racism can be regarded as fighting for the joint purpose of...

  18. Distribution and specific central projections of mechanoreceptors in the thorax and proximal leg joints of locusts. I. Morphology, location and innervation of internal proprioceptors of pro- and metathorax and their central projections.

    Science.gov (United States)

    Bräunig, P; Hustert, R; Pflüger, H J

    1981-01-01

    The mechanoreceptive supply of ventral thoracic parts and proximal leg joints of the pro- and metathorax of two locust species has been studied with the help of a modification of the axonal infusion technique with cobaltous chloride, which permits staining of the peripheral nervous system of an entire segment. The number, location, and innervation of serially homologous chordotonal organs (CO), strand receptors (SR), multipolar sensilla (MS), hair plates (HP) and clustered campaniform sensilla (CS) are described, as well as population specific central projections of primary afferent fibers from internal receptors (CO, MS). CO projections tend to form intersegmental projections within the thoracic ganglia, the extent varying with the organ's location. Apart from dorso-lateral collaterals, they terminate mainly in the medioventral neuropile, where they also cross the longitudinal midline of the CNS. By contrast, MS projections stay ipsilateral and do not leave their ganglia, where they send collaterals into all levels of the neuropile.

  19. Advocating vaccination of adults aged 60 years and older in Western Europe: statement by the Joint Vaccine Working Group of the European Union Geriatric Medicine Society and the International Association of Gerontology and Geriatrics-European Region.

    Science.gov (United States)

    Michel, Jean-Pierre; Chidiac, Christian; Grubeck-Loebenstein, Beatrix; Johnson, Robert W; Lambert, Paul Henri; Maggi, Stefania; Moulias, Robert; Nicholson, Karl; Werner, Hans

    2009-04-01

    Vaccines are an underused public health strategy for healthy aging. Considering the risks of vaccine-preventable diseases and the current low vaccine coverage rates in older European citizens, the two European geriatric and gerontological societies (European Union Geriatric Medicine Society [EUGMS] and International Association of Gerontology and Geriatrics-European Region [IAGG-ER]) convened a Joint Vaccine Working Group to develop a consensus document advocating routine vaccination of aging populations. The mandate of this Working Group was to improve the uptake of routine vaccinations in adults aged 60 years and over. The consensus statement underlines the need to establish, strengthen, and harmonize European policies that continue routine vaccinations to adulthood and that will include older populations. Improved vaccination rates will promote healthy aging by reducing the burden of vaccine-preventable infectious diseases in older populations, a population that is rapidly increasing in Europe.

  20. A set of hypotheses on tribology of mammalian herbivore teeth

    Science.gov (United States)

    Kaiser, Thomas M.; Clauss, Marcus; Schulz-Kornas, Ellen

    2016-03-01

    Once erupted, mammal cheek teeth molars are continuously worn. Contact of molar surfaces with ingesta and with other teeth contribute to this wear. Microscopic wear features (dental surface texture) change continuously as new wear overprints old texture features. These features have been debated to indicate diet. The general assumption in relating occlusal textures to diet is that they are independent of masticatory movements and forces. If this assumption is not accepted, one needs to propose that occlusal textures comprise signals not only from the ‘last supper’ but also from masticatory events that represent ecological, species- or taxon-specific adaptations, and that occlusal textures therefore give a rather unspecific, somehow diet-related signal that is functionally inadequately understood. In order to test for mechanical mechanisms of wear, we created a hypothesis matrix that related sampled individuals with six tribological variables. Three variables represent mechanically relevant ingesta properties, and three represent animal-specific characteristics of the masticatory system. Three groups of mammal species (free ranging Cetartiodactyla and Perissodactyla, free ranging primates, and artificially fed rabbits) were investigated in terms of their 3D dental surface textures, which were quantified employing ten ISO 25178 surface texture parameters. We first formulated a set of specific predictions based on theoretical reflections on the effects of diet properties and animal characteristics, and subsequently performed discriminant analysis to test which parameters actually followed these predictions. We found that parameters Vvc, Vmc, Sp, Sq allowed the prediction of both, ingesta properties and properties of the masticatory system, if combined with other parameters. Sha, Sda and S5v had little predictive power in our dataset. Spd seemed rather unrelated to ingesta properties and made this parameter a suitable indicator of masticatory system properties.

  1. Fiscal 1997 report on a feasibility study of international joint researches in the Asian region; 1997 nendo chosa hokokusho (Asia chiiki kokusai kyodo kenkyu kanosei chosa (4)hokokusho)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-03-01

    It is thought that the energy consumption in Asian countries with ASEAN and China as center will a marked growth also in future together with a rapid economic growth, but harmony with environmental problems and economic growth is being taken as a serious problem. This is an important issue also to Japan from viewpoints of secure energy supply and regional response to the environmental issue. Accordingly, strongly desired is positive response to global environmental issues and promotion in development/spread of new energy/energy conservation in these countries. For the spread of the technologies, actual construction/operation of plants by joint researches with Japan are effective from aspects of personnel raising, technical improvement, PR effects, etc. This is also helpful for Japan in terms of technological development because Japan can also get the unobtainable data from the operation under appropriate conditions. This is a report on the studies of the trends of global environmental problems in Thailand, Indonesia, Malaysia, the Philippines, India and China. 3 figs., 72 tabs.

  2. Improved clean development mechanism and joint implementation to promote holistic sustainable development - an integrated policy and methodology for international energy collaboration

    Energy Technology Data Exchange (ETDEWEB)

    Kua Harn Wei

    2007-07-01

    The current Clean Development Mechanism/Joint Implementation framework does not emphasize on wholistic sustainability of energy projects. The Golden Standard was a good example of how this framework can be fine-tuned. However, it does not explicitly incentivize the adoption of the sustainability standards it outlines. A 4-element integrated policy strategy is proposed. A Sustainability Assessment Matrix is constructed to evaluate project proposals' sustainability performance. The Probational Sustainability Performance Demand requires continual monitoring of this performance of approved projects throughout a designated probation period. The involved countries will be awarded Sustainability Credits (measured with the matrix) in installments according to their performance within this period. The Probational Emission Reduction Demand requires investing countries to meet moderated emission reduction targets in order for them to claim the certified emission reductions/ emission reduction credits and their share of Sustainability Credits. These credits are converted into Sustainability Assistance Funds, which can be channeled back to finance either the approved projects or independent renewable energy projects in the involved countries. The MIT Energy Cost Model is used to estimate the required amount and identify the forms of such assistance package. Finally, an integrated policymaking framework is suggested to execute and monitor these interconnected policy elements. (auth)

  3. The Structure and Characteristics of Tribological Systems with Diamond Like Carbon Coatings under Ionic Liquid Lubrication Conditions

    Directory of Open Access Journals (Sweden)

    Madej M.

    2016-06-01

    Full Text Available The results from the tests on tribological a-C:H diamond coatings deposited by PACVD (plasma assisted chemical vapour deposition on 100Cr6 steel components are presented in this work. Mechanical properties - nanohardness and Young’s modulus - were assessed by instrumented indentation. Tribological tests were conducted with T-01M tester in a ball-on-disc test under dry and boundary friction conditions. Selected ionic liquids - synthetic new generation lubricants - were used for lubrication. The results from the experiments indicate that diamond-like coatings improved tribological characteristics of the friction pairs tested, with the ionic liquids intensifying this effect.

  4. The Tribological Efficiency and the Mechanism of Action of Nano-Porous Composition Base Brake Lining Materials

    Science.gov (United States)

    Kutelia, E. R.; Gventsadze, D. I.; Eristavil, B. G.; Maisuradze, N. I.; Tsurtsumia, O. O.; Gventsadze, L. D.; Olofsson, U.; Wahlström, J.; Olander, L.

    2011-12-01

    Based on the comparative analysis of the experimental values determined for the tribological parameters for the three novel nano-porous composition base and two conventional brake lining materials while friction with the grey cast iron disc, it was shown the considerable high tribological efficiency of the novel nano-porous composition base lining materials in comparison with the conventional (from EU and USA market) brake lining materials. The explanation is given to the action mechanism of nano-porous composition base brake lining material and its tribological efficiency basing on the "triple phase" tribo-pair model.

  5. Self-lubricating tribological characterization of lead free Fe-Cu based plain bearing material

    Directory of Open Access Journals (Sweden)

    Shuhaib Mushtaq

    2017-03-01

    Full Text Available The negative impact of lead on environment and thereby its reciprocity on the health of mankind, there is a growing emphasis on resisting the usage of lead in bearings. Owing to this, new bearing materials that provide comparable tribological performance to that of lead containing alloys are being developed. In this study, lead free Fe-Cu based powders with addition of elements such as tin, molybdenum disulfide and Nano boron nitride (BN have been developed by powder metallurgy (PM technique in order to improve the tribological and mechanical properties. The powder mixtures were compressed at a pressure of 500 MPa, and then sintered in dry hydrogen atmosphere at 9000C for 50 minutes. The mechanical and tribological properties obtained due to addition of the said elements is presented in this study. The tribological behavior of the selected alloys is analyzed by reciprocating-sliding tests under dry conditions. The morphology of wear scars and the microstructure of the wear surfaces were investigated. The material with 2.5 wt.% of Sn exhibited the highest value of hardness, the material with 7.5 wt.% of Nano BN comparably shows the low coefficient of friction and wear rate as compared with 5 wt.% of Nano BN.

  6. Influence of service temperature on tribological characteristics of self-lubricant coatings: A review

    Institute of Scientific and Technical Information of China (English)

    Jun-Feng YANG; Yan JIANG; Jens HARDELL; Braham PRAKASH; Qian-Feng FANG

    2013-01-01

    Self-lubricating coatings have been widely used to reduce friction in moving machine assemblies. However, the tribological performance of these coatings is strongly dependent on the service temperature. In this paper, an extensive review pertaining to the influence of operating service temperature on tribological performance of self-lubricating coatings has been carried out. Based on the effective lubricating temperature range, the self-lubricating coatings developed in the past have been divided into three groups: low temperature lubricant coating (from -200℃ to room temperature), moderate temperature lubricant coating (from room temperature to 500℃) and high temperature lubricant coating (〉 500℃). Ideas concerning possible ways to extend the operating temperature range of self-lubricating coatings have been presented as follows: hybridized tribological coating, adaptive tribological coatings, and diffusion rate limited solid lubricant coating, in addition, a new self-lubricating coating formulation for potential application at a wide operating temperature range has been proposed.

  7. Tribological performance of self-lubricating aluminum matrix nanocomposites: Role of graphene nanoplatelets

    Directory of Open Access Journals (Sweden)

    Meysam Tabandeh-Khorshid

    2016-03-01

    Full Text Available In the present investigation, aluminum matrix nanocomposites reinforced by graphene nanoplatelets were synthesized by powder metallurgy method. The microstructure of the Al-Graphene nanoplatelets sample was investigated by TEM. The hardness measurements of these samples were investigated using a Rockwell hardness tester. To investigate the tribological behavior of aluminum matrix composites reinforced by graphene nanoplatelets and pure aluminum, pin-on-disk experiments were conducted on the prepared samples. In the experiments, the influence of reinforcement, volume fraction, normal load, and sliding velocity on the tribological performance was investigated. Results showed that the wear rate of Al-1wt.% GNP is increased with increasing normal loads. However, the coefficient of friction (COF of the Al-1wt.% GNP decreased with increasing normal loads. Formation of graphene film on the worn surface of Al-1wt.% GNP sample and morphology of the worn surfaces of aluminum and composite samples were analyzed by Optical Microscope (OM and Scanning Electron Microscope (SEM. It was found that the graphene nanoplatelets reinforced nano-composites showed superior tribological properties and demonstrated the ability of the self-lubricating nature of the composite during tribological conditions.

  8. Piezoelectric impact force sensor array for tribological research on rigid disk storage media

    NARCIS (Netherlands)

    Burger, G.J.; Lammerink, T.S.J.; Fluitman, J.H.J.; Imai, S.; Tokuyama, M.; Hirose, S.

    1995-01-01

    This paper presents a method to measure impact forces on a surface by means of a piezoelectric thin film sensor array. The output signals of the sensor array provide information about the position, magnitude and wave form of the impact force. The sensor array may be used for tribological studies to

  9. Microstructure and tribological performance of diamond-like carbon films deposited on hydrogenated rubber

    NARCIS (Netherlands)

    Pal, J.P. van der; Martinez Martinez, Diego; Pei, Y.T.; Rudolf, P.; Hosson, J.Th.M. De

    2012-01-01

    In this paper, the microstructure and tribological performance of diamond-like carbon (DLC) films prepared by plasma chemical vapor deposition on hydrogenated nitrile butadiene rubbers (HNBR) are studied. Different negative variations of temperature during film growth were selected by proper changes

  10. Tribological and wear behavior of HfN/VN nanomultilayer coated cutting tools

    Directory of Open Access Journals (Sweden)

    Willian Aperador Chaparro

    2014-03-01

    Full Text Available Wear and tribological behavior of [HfN/VN]n multinanolayers deposited via magnetron sputtering has been exhaustively studied in this work. Enhancement of both hardness and elastic modulus up to 37 GPa and 351 GPa, respectively, was observed as bilayer periods in the coatings were decreased. The sample with a bilayer period (Λ of 15 nm and bilayer number n = 80, showed the lowest friction coefficient (∼0.15 and the highest critical load (72 N, corresponding to 2.2 and 1.38 times better than those values for the coating deposited with n = 1, respectively. Taking into account the latest results of tungsten carbide (WC inserts were used as substrates to improve the mechanical and tribological properties of [HfN/VN]n coatings as a function of increased interface number and to manage higher efficiency of these coatings in different industrial applications, like machining and extrusion. Their physical, mechanical, and tribological characteristics were investigated, including cutting tests with AISI 1020 steel (workpiece to assess wear as a function of the bilayer number and bilayer period. A comparison of the tribological properties revealed a decrease of flank wear (approximately 24% for WC inserts coated with [HfN/VN]80 (Λ =15 nm, when compared to uncoated tungsten carbide inserts. These results demonstrate the possibility of using [HfN/VN] multilayers as new coatings for tool machining with excellent industrial performance.

  11. Pin-on-disk apparatus for tribological studies of polymeric materials

    DEFF Research Database (Denmark)

    Ølholm Larsen, Thomas; Løgstrup Andersen, Tom; Thorning, Bent

    2009-01-01

    polymeric materials under dry-sliding conditions. The different main parts of the apparatus are described in a way which partly explains the choice of construction and partly makes it possible to produce a similar apparatus. Furthermore, a limited amount of tribological data is presented mainly to exemplify...

  12. Influence of CaCO3 Whisker Content on Mechanical and Tribological Properties of Polyetheretherketone Composites

    Institute of Scientific and Technical Information of China (English)

    Youxi LIN; Chenghui GAO; Ning LI

    2006-01-01

    The mechanical and tribological properties of polyetheretherketone(PEEK)composites filled with CaCO3 whisker in various content of 0~45%(wt pct)were investigated. The composite specimens were prepared by compression molding. Tribological testing of composites in dry wear mode against carbon steel ring was carried out on a MM200 block-on-ring apparatus. Data on neat PEEK were also included for comparison. It was observed that inclusion of CaCO3 whisker affected the most mechanical properties and the friction and wear in a beneficial way. With an increase in CaCO3 whisker content, friction coefficient continuously decreased but the trends in wear performance varied. The specific wear rate showed minima as 1.28×10-6 mm3/Nm for 15% CaCO3 whisker inclusion followed by a slow increase for further CaCO3 whisker addition. In terms of friction applications, when the tribological and mechanical properties are combined, the optimal content of CaCO3 whisker in the filled PEEK should be recommended as 15% to 20%. Fairly good correlations are observed in friction coefficient vs bending modulus and wear rate vs bending strength, confirming that the bending properties prove to be the most important tribology controlling parameters in the present work.

  13. Tribological properties of the two-step thermally deposited chromium films

    NARCIS (Netherlands)

    Lazauskas, A.; Baltrusaitis, J.; Grigaliunas, V.; Baltusnikas, A.; Abakeviciene, B.; Polcar, T.

    2013-01-01

    Chromium thin films were prepared on glass substrate via a two-step thermal deposition and their structural, chemical and tribological properties were determined. The X-ray diffraction pattern of the two-step thermally deposited chromium film showed the presence of well-defined body-centered cubic C

  14. Tribological study of a highly hydrolytically stable phenylboronic acid ester containing benzothiazolyl in mineral oil

    Energy Technology Data Exchange (ETDEWEB)

    Li, Zhipeng [School of Chemistry and Chemical Engineering, Key Laboratory for Thin Film and Microfabrication of the Ministry of Education, Shanghai Jiao Tong University, 200240 (China); Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Li, Xiufeng; Zhang, Yawen [School of Chemistry and Chemical Engineering, Key Laboratory for Thin Film and Microfabrication of the Ministry of Education, Shanghai Jiao Tong University, 200240 (China); Ren, Tianhui, E-mail: thren@sjtu.edu.cn [School of Chemistry and Chemical Engineering, Key Laboratory for Thin Film and Microfabrication of the Ministry of Education, Shanghai Jiao Tong University, 200240 (China); Zhao, Yidong [Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100039 (China); Zeng, Xiangqiong; Heide, E. van der [Laboratory for Surface Technology and Tribology, University of Twente, Drienerlolaan 5, 7522 NB Enschede (Netherlands)

    2014-07-01

    A novel long chain alkyl phenylboronic acid ester containing heterocyclic compound, bis (1-(benzothiazol-2-ylthio) propan-2-yl)-4-dodecylphenylboronic acid ester (DBBMT), was synthesized and characterized. The hydrolytic stability of the DBBMT was evaluated and the results show that DBBMT is of outstanding hydrolytic stability compared with normal borate esters, which indicates that the designed molecular structure, by introducing benzene ring to conjugate with the electron-deficient boron and the benzothiazole as a hinder group, is effective on obtaining a hydrolytically stable long chain alkyl phenylboronic acid ester. The tribological properties of DBBMT and ZDDP in mineral base oil were evaluated using a four-ball tribometer, which suggests that the DBBMT possesses comprehensive tribological properties and could be a potential candidate for the replacement of ZDDP. Furthermore, in order to understand the tribological behaviors, the worn surface was analyzed by X-ray photoelectron spectroscopy (XPS) and X-ray absorption near edge structure (XANES) spectroscopy. The results indicate that the elements S, B, O and Fe perform complicated tribochemical reactions to form the compact tribological film composed of B{sub 2}O{sub 3}, FeS, Fe{sub 3}O{sub 4} and FeSO{sub 4}.

  15. Covalently bound fluorine-containing monolayers on silicon and oxides : formation, stability and tribology

    NARCIS (Netherlands)

    Pujari, S.P.

    2013-01-01

    The formation of fluorinated monolayers with a minimized surface energy and an improved chemical stability on specific substrates will enable outstanding tribological properties and is the main goal of the research described in this thesis. Inorganic substrates, such as Si(111), silicon carbide (SiC

  16. Investigation of Tribological Properties of Cu Nanoparticle as Lubricating Oil Additive

    Institute of Scientific and Technical Information of China (English)

    LIU Qian; XU Yi; SHI Pei-jing; XU Bin-shi

    2004-01-01

    Cu nanoparticles with average diameter of 20 nm have been successfully prepared by chemically reduction in solution. The Cu nanoparticles have the same structure as bulk Cu and its tribological properties as additives in oil have been evaluated with a T-11 tester. The results show that Cu nanoparticles exhibit good performance in anti-wear and friction reduction.

  17. Tribological investigation of metal-ceramic composite coatings in high temperature

    Institute of Scientific and Technical Information of China (English)

    H.T.MA; R.J.ZHANG; Y.S.JIN; G.Barbezat

    2001-01-01

    The high temperature tribological properties of metal-based ceramic coating containingoxidation under dry wear condition were studied in this paper. It shows that the coating exhibitedself-lubricated properties only in the high temperature range, and the abrasion, adhesion and oxi-dation are the main wear modes.

  18. Adequacy of surface analytical tools for studying the tribology of ceramics

    Science.gov (United States)

    Sliney, H. E.

    1986-01-01

    Surface analytical tools are very beneficial in tribological studies of ceramics. Traditional methods of optical microscopy, XRD, XRF, and SEM should be combined with newer surface sensitive techniques especially AES and XPS. ISS and SIMS can also be useful in providing additional compositon details. Tunneling microscopy and electron energy loss spectroscopy are less known techniques that may also prove useful.

  19. Computational techniques in tribology and material science at the atomic level

    Science.gov (United States)

    Ferrante, J.; Bozzolo, G. H.

    1992-01-01

    Computations in tribology and material science at the atomic level present considerable difficulties. Computational techniques ranging from first-principles to semi-empirical and their limitations are discussed. Example calculations of metallic surface energies using semi-empirical techniques are presented. Finally, application of the methods to calculation of adhesion and friction are presented.

  20. Assessment the possibility of enhancing the tribological properties of the ferritic-austenitic cast steel

    Directory of Open Access Journals (Sweden)

    A. Brodziak

    2010-01-01

    Full Text Available The purpose of the research was to explore the possibility of enhancing the tribological properties of the ferritic-austenitic cast steel which is widely used in combustion gas desulphurization systems in the power industry. The subject of the research is the GX2CrNiMoN25-6-3 cast steel, a material for making pump rotors and other parts intended for operation at a temperature of up to 70°C in a water suspension containing Cl- and SO4-2 ions and sand / gypsum particles. It seems that in some applications, at low dynamics of parts’ operation and a predominance of erosive phenomena over corrosive ones, there is a potential for using the σ phase as a structural constitu-ent that enhances the tribological properties. However, due to the increased brittleness of the material, a need arises for optimizing the quantity of this phase and carrying out detailed research into the morphology of precipitates. To describe the tribological properties, the testing of the erosive and corrosive wear mechanism was used, which was carried out on a test stand of the authors' own construction. Metallographic and stereological examinations and hardness tests were performed, which enabled the understanding of the successive stages of tribological wear of the cast steel under investigation. The increasing volumetric share of the σ phase advantageously influenced the erosive wear resistance of the material.