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Sample records for fractures principles technique

  1. Percutaneous treatment of insufficiency fractures. Principles, technique and review of literature

    International Nuclear Information System (INIS)

    Beall, Douglas P.; Datir, Abhijit; D'Souza, Sharon L.; D'Souza, Logan S.; Gunda, Divya; Morelli, John; Johnson, Michael Brandon; Nabavizadeh, Nima

    2010-01-01

    Insufficiency fractures of the pelvis, sacrum, spine, and long bones are painful, debilitating, and are common consequences of osteoporosis. Conventional treatment for these fractures varies from conservative therapy to surgery with plate and screw fixation. The former fails to address the underlying problem of fracture and frequently does not alleviate symptoms, while the latter is invasive and not always possible in older populations with low bone density and numerous co-morbidities. Osseous augmentation with polymethylmethacrylate (PMMA) has been used for over two decades to treat fractures related to osteoporosis, but has not been commonly used to treat fractures outside of the vertebral bodies. Osseous augmentation with PMMA is an image-guided procedure and various techniques have been utilized to treat fracture in different locations. We describe various techniques for image-guided osseous augmentation and treatment of insufficiency fractures with bothPMMA and allograft bone for fractures of the pelvis including sacrum, acetabulum, pubic symphysis, pubic rami ilium; appendicular skeleton including distal radius, proximal femur, and vertebral body. We also describe the potential risks and complications associated with percutaneous treatment of insufficiency fractures and techniques to avoid the pitfalls of the various procedures. We will present the process for patient follow-up and data regarding the pre- and postprocedure pain response in patients undergoing treatment for pelvic insufficiency fractures. (orig.)

  2. Basic principles of fracture treatment in children.

    Science.gov (United States)

    Ömeroğlu, Hakan

    2018-04-01

    This review aims to summarize the basic treatment principles of fractures according to their types and general management principles of special conditions including physeal fractures, multiple fractures, open fractures, and pathologic fractures in children. Definition of the fracture is needed for better understanding the injury mechanism, planning a proper treatment strategy, and estimating the prognosis. As the healing process is less complicated, remodeling capacity is higher and non-union is rare, the fractures in children are commonly treated by non-surgical methods. Surgical treatment is preferred in children with multiple injuries, in open fractures, in some pathologic fractures, in fractures with coexisting vascular injuries, in fractures which have a history of failed initial conservative treatment and in fractures in which the conservative treatment has no/little value such as femur neck fractures, some physeal fractures, displaced extension and flexion type humerus supracondylar fractures, displaced humerus lateral condyle fractures, femur, tibia and forearm shaft fractures in older children and adolescents and unstable pelvis and acetabulum fractures. Most of the fractures in children can successfully be treated by non-surgical methods.

  3. Principles of fluorescence techniques

    CERN Document Server

    2016-01-01

    Fluorescence techniques are being used and applied increasingly in academics and industry. The Principles of Fluorescence Techniques course will outline the basic concepts of fluorescence techniques and the successful utilization of the currently available commercial instrumentation. The course is designed for students who utilize fluorescence techniques and instrumentation and for researchers and industrial scientists who wish to deepen their knowledge of fluorescence applications. Key scientists in the field will deliver theoretical lectures. The lectures will be complemented by the direct utilization of steady-state and lifetime fluorescence instrumentation and confocal microscopy for FLIM and FRET applications provided by leading companies.

  4. Laboratory reptile surgery: principles and techniques.

    Science.gov (United States)

    Alworth, Leanne C; Hernandez, Sonia M; Divers, Stephen J

    2011-01-01

    Reptiles used for research and instruction may require surgical procedures, including biopsy, coelomic device implantation, ovariectomy, orchidectomy, and esophogostomy tube placement, to accomplish research goals. Providing veterinary care for unanticipated clinical problems may require surgical techniques such as amputation, bone or shell fracture repair, and coeliotomy. Although many principles of surgery are common between mammals and reptiles, important differences in anatomy and physiology exist. Veterinarians who provide care for these species should be aware of these differences. Most reptiles undergoing surgery are small and require specific instrumentation and positioning. In addition, because of the wide variety of unique physiologic and anatomic characteristics among snakes, chelonians, and lizards, different techniques may be necessary for different reptiles. This overview describes many common reptile surgery techniques and their application for research purposes or to provide medical care to research subjects.

  5. The hologram principles and techniques

    CERN Document Server

    Richardson, Martin J

    2018-01-01

    Written by Martin Richardson (an acclaimed leader and pioneer in the field) and John Wiltshire, The Hologram: Principles and Techniques is an important book that explores the various types of hologram in their multiple forms and explains how to create and apply the technology. The authors offer an insightful overview of the currently available recording materials, chemical formulas, and laser technology that includes the history of phase imaging and laser science. Accessible and comprehensive, the text contains a step-by-step guide to the production of holograms. In addition, The Hologram outlines the most common problems encountered in producing satisfactory images in the laboratory, as well as dealing with the wide range of optical and chemical techniques used in commercial holography. The Hologram is a well-designed instructive tool, involving three distinct disciplines: physics, chemistry, and graphic arts. This vital resource offers a guide to the development and understanding of the recording of mater...

  6. Pediatric Ankle Fractures: Concepts and Treatment Principles

    Science.gov (United States)

    Su, Alvin W.; Larson, A. Noelle

    2016-01-01

    Synopsis Current clinical concepts are reviewed regarding the epidemiology, anatomy, evaluation and treatment of pediatric ankle fractures. Correct diagnosis and management relies on appropriate exam, imaging, and knowledge of fracture patterns specific to children. Treatment is guided by patient history, physical examination, plain film radiographs and, in some instances, CT. Treatment goals are to restore acceptable limb alignment, physeal anatomy, and joint congruency. For high risk physeal fractures, patients should be monitored for growth disturbance as needed until skeletal maturity. PMID:26589088

  7. Analytical chemistry: Principles and techniques

    International Nuclear Information System (INIS)

    Hargis, L.G.

    1988-01-01

    Although this text seems to have been intended for use in a one-semester course in undergraduate analytical chemistry, it includes the range of topics usually encountered in a two-semester introductory course in chemical analysis. The material is arranged logically for use in a two-semester course: the first 12 chapters contain the subjects most often covered in the first term, and the next 10 chapters pertain to the second (instrumental) term. Overall breadth and level of treatment are standards for an undergraduate text of this sort, and the only major omission is that of kinetic methods (which is a common omission in analytical texts). In the first 12 chapters coverage of the basic material is quite good. The emphasis on the underlying principles of the techniques rather than on specifics and design of instrumentation is welcomed. This text may be more useful for the instrumental portion of an analytical chemistry course than for the solution chemistry segment. The instrumental analysis portion is appropriate for an introductory textbook

  8. Principles of pediatric mandibular fracture management.

    Science.gov (United States)

    Cole, Patrick; Kaufman, Yoav; Izaddoost, Shayan; Hatef, Daniel A; Hollier, Larry

    2009-03-01

    Mandible fractures are commonplace in today's craniofacial practice; however, managing the infrequent, operative pediatric mandible injury requires a thorough knowledge base and thoughtful approach. Not only do these patients demonstrate variable anatomy due to differing stages of dental eruption, but condylar disruption may translate into long-term growth disturbance. In addition, patient immaturity often complicates cooperation, and both fixation strategies and postoperative planning must take this into account. As a supplement to the authors' video presentation, the present article focuses on repair of the symphyseal fracture and bilateral condylar injuries in the pediatric patient.

  9. Test techniques for fracture mechanics testing

    International Nuclear Information System (INIS)

    Schwalbe, K.H.

    1980-01-01

    Test methods for fracture mechanics tests are described. Two groups of techniques are distinguished: Those for measurement of stable crack growth and those for determination of the loading parameters. (orig.) [de

  10. Proximal femoral fractures: Principles of management and review of literature

    Science.gov (United States)

    Mittal, Ravi; Banerjee, Sumit

    2012-01-01

    Purpose The purpose of this study was to review the principles involved in the management of proximal femoral fractures as reported in the literature. Methods: A medical literature search in the MEDLINE (PubMed) and Cochrane database was undertaken to review strategies and principles in proximal femoral fracture treatment. Randomized control trials and meta analysis were given preference while case reports/small series were rejected. Results and conclusions: Early anatomical reduction and surgical fixation remains the best option to reduce the risk of complications like non-union and avascular necrosis in treating fracture neck femurs. Cancellous screws continue to be the preferred treatment for fixation of neck femur fractures in younger population until the benefit of using sliding hip screws is validated by large multicentric studies. In the geriatric age group, early prosthetic replacement brings down the mortality and morbidity associated with neck femur fractures. Sliding hip screw (DHS) is the best available option for stable inter trochanteric fractures. The use of intramedullary nails e.g. PFN is beneficial in treating inter trochanteric fractures with comminution and loss of lateral buttress. Intramedullary implants have been proven to have increased success rates in subtrochanteric fractures and should be preferred over extramedullary plate fixation systems. PMID:25983451

  11. Educational principles and techniques for interpreters.

    Science.gov (United States)

    F. David Boulanger; John P. Smith

    1973-01-01

    Interpretation is in large part education, since it attempts to convey information, concepts, and principles while creating attitude changes and such emotional states as wonder, delight, and appreciation. Although interpreters might profit greatly by formal training in the principles and techniques of teaching, many have not had such training. Some means of making the...

  12. Diagnosis of scaphoid fracture: optimal imaging techniques

    Directory of Open Access Journals (Sweden)

    Geijer M

    2013-07-01

    Full Text Available Mats Geijer Center for Medical Imaging and Physiology, Skåne University Hospital and Lund University, Lund, Sweden Abstract: This review aims to provide an overview of modern imaging techniques for evaluation of scaphoid fracture, with emphasis on occult fractures and an outlook on the possible evolution of imaging; it also gives an overview of the pathologic and anatomic basis for selection of techniques. Displaced scaphoid fractures detected by wrist radiography, with or without special scaphoid views, pose no diagnostic problems. After wrist trauma with clinically suspected scaphoid fracture and normal scaphoid radiography, most patients will have no clinically important fracture. Between 5% and 19% of patients (on average 16% in meta-analyses will, however, have an occult scaphoid fracture which, untreated, may lead to later, potentially devastating, complications. Follow-up imaging may be done with repeat radiography, tomosynthesis, computed tomography, magnetic resonance imaging (MRI, or bone scintigraphy. However, no method is perfect, and choice of imaging may be based on availability, cost, perceived accuracy, or personal preference. Generally, MRI and bone scintigraphy are regarded as the most sensitive modalities, but both are flawed by false positive results at various rates. Keywords: occult fracture, wrist, radiography, computed tomography, magnetic resonance imaging, radionuclide imaging

  13. Phase equilibria basic principles, applications, experimental techniques

    CERN Document Server

    Reisman, Arnold

    2013-01-01

    Phase Equilibria: Basic Principles, Applications, Experimental Techniques presents an analytical treatment in the study of the theories and principles of phase equilibria. The book is organized to afford a deep and thorough understanding of such subjects as the method of species model systems; condensed phase-vapor phase equilibria and vapor transport reactions; zone refining techniques; and nonstoichiometry. Physicists, physical chemists, engineers, and materials scientists will find the book a good reference material.

  14. Principles of modern radar advanced techniques

    CERN Document Server

    Melvin, William

    2012-01-01

    Principles of Modern Radar: Advanced Techniques is a professional reference for practicing engineers that provides a stepping stone to advanced practice with in-depth discussions of the most commonly used advanced techniques for radar design. It will also serve advanced radar academic and training courses with a complete set of problems for students as well as solutions for instructors.

  15. Adolescent Volar Barton Fracture with Open Physis treated with Volar Plating using Buttressing Principle

    Directory of Open Access Journals (Sweden)

    Shah H

    2015-07-01

    Full Text Available Objective: The objective of the study was to assess the outcome of Salter- Harris type III distal radius fracture fixed using the principle of buttressing and avoiding screw insertion through the physis. Materials and Method: Eight school going children in the age group of 11-16 years with volar Barton fractures were treated with a volar plate using the buttress principle without inserting screws in the distal fragment. Patients were evaluated over a period of 18 months. Clinical evaluation was done using the Green O’Brien criteria and radiological evaluation using the Sarmiento criteria. Results: The average union time was two months. All the patients had good to excellent functional outcome with full extension and flexion. Conclusion: Buttress plating of volar Barton fractures in the adolescent age group is an excellent technique to achieve satisfactory outcome without violation of the physis.

  16. Pediatric mandibular fractures: a free hand technique.

    Science.gov (United States)

    Davison, S P; Clifton, M S; Davison, M N; Hedrick, M; Sotereanos, G

    2001-01-01

    The treatment of pediatric mandibular fractures is rare, controversial, and complicated by mixed dentition. To determine if open mandibular fracture repair with intraoral and extraoral rigid plate placement, after free hand occlusal and bone reduction, without intermaxillary fixation (IMF), is appropriate and to discuss postoperative advantages, namely, maximal early return of function and minimal oral hygiene issues. A group of 29 pediatric patients with a mandibular fracture were examined. Twenty pediatric patients (13 males and 7 females) with a mean age of 9 years (age range, 1-17 years) were treated using IMF. All patients were treated by the same surgeon (G.S.). Surgical time for plating was reduced by 1 hour, the average time to place patients in IMF. The patients who underwent open reduction internal fixation without IMF ate a soft mechanical diet by postoperative day 3 compared with postoperative day 16 for those who underwent IMF. Complication rates related to fixation technique were comparable at 20% for those who did not undergo IMF and 33% for those who did. We believe that free hand reduction is a valuable technique to reduce operative time for pediatric mandibular fractures. It maximizes return to function while minimizing the oral hygiene issues and hardware removal of intermaxillary function.

  17. Academic Training: Particle Detectors - Principles and Techniques

    CERN Multimedia

    Françoise Benz

    2005-01-01

    2004-2005 ACADEMIC TRAINING PROGRAMME LECTURE SERIES FOR POSTGRADUATE STUDENTS 11, 12, 13, 14 & 15 April from 11.00 to 12.00 hrs - Main Auditorium, bldg. 500 Particle Detectors - Principles and Techniques C. JORAM, L. ROPELEWSKI, M. MOLL, C. D'AMBROSIO, T. GYS / CERN-PH The lecture series presents an overview of the physical principles and basic techniques of particle detection, applied to current and future high energy physics experiments. Illustrating examples, chosen mainly from the field of collider experiments, demonstrate the performance and limitations of the various techniques. Main topics of the series are: interaction of particles and photons with matter; particle tracking with gaseous and solid state devices, including a discussion of radiation damage and strategies for improved radiation hardness; scintillation and photon detection; electromagnetic and hadronic calorimetry; particle identification using specific energy loss dE/dx, time of flight, Cherenkov light and transition radi...

  18. Digital Holographic Microscopy Principles, Techniques, and Applications

    CERN Document Server

    Kim, Myung K

    2011-01-01

    Digital holography is an emerging field of new paradigm in general imaging applications. By replacing the photochemical procedures with electronic imaging and having a direct numerical access to the complex optical field, a wide range of new imaging capabilities become available, many of them difficult or infeasible in conventional holography. An increasing number of researchers—not only in optical physics and optical engineering, but also in diverse applications areas such as microbiology, medicine, marine science, particle analysis, microelectromechanics, and metrology—are realizing and exploiting the new capabilities of digital holography. Digital Holographic Microscopy: Principles, Techniques, and Applications, by Dr. Myung K. Kim, is intended to provide a brief but consistent introduction to the principles of digital holography as well as to give an organized overview of the large number of techniques and applications being developed. This will also shed some light on the range of possibilities for f...

  19. Machine Learning Principles Can Improve Hip Fracture Prediction

    DEFF Research Database (Denmark)

    Kruse, Christian; Eiken, Pia; Vestergaard, Peter

    2017-01-01

    Apply machine learning principles to predict hip fractures and estimate predictor importance in Dual-energy X-ray absorptiometry (DXA)-scanned men and women. Dual-energy X-ray absorptiometry data from two Danish regions between 1996 and 2006 were combined with national Danish patient data.......89 [0.82; 0.95], but with poor calibration in higher probabilities. A ten predictor subset (BMD, biochemical cholesterol and liver function tests, penicillin use and osteoarthritis diagnoses) achieved a test AUC of 0.86 [0.78; 0.94] using an “xgbTree” model. Machine learning can improve hip fracture...... prediction beyond logistic regression using ensemble models. Compiling data from international cohorts of longer follow-up and performing similar machine learning procedures has the potential to further improve discrimination and calibration....

  20. Principles and techniques of gamma ray tracers

    International Nuclear Information System (INIS)

    Claxton, K.T.

    1978-01-01

    Radioactive tracer techniques provide a very sensitive means of studying physical and chemical processes in a whole variety of different media. Some of the techniques and principles of radioactive tracers and their application to practical engineering systems are discussed. Information which has been found useful in the design of high temperature liquid sodium facilities employing radio-tracers, is presented. The report deals solely with the use of gamma-emitting species as the tracer. These find particular application for in-situ studies on engineering systems where the highly penetrating properties of gamma rays are needed for detection through strongly absorbent media such as stainless steel pepe walls. (author)

  1. Fracture detection using subsurface electromagnetic techniques

    International Nuclear Information System (INIS)

    Zhou, Q.; Becker, A.; Goldstein, N.E.; Morrison, H.F.; Lee, K.H.

    1987-01-01

    Audio frequency subsurface electromagnetic (EM) techniques using cross-hole and in-hole arrays for fracture detection are evaluated numerically. The fracture zone is represented by a thin rectangular conductor with finite dimensions, embedded in a conductive host rock. Because of its practical advantages, the EM source considered in this study is a grounded vertical electrical dipole (G.V.E.D.) placed in a vertical bore hole. Three source-receiver configurations are considered. The first is the cross-hole configuration with the source and receiver moving parallel to each other in separate holes. The second configuration is a fixed source in one hole and a moving receiver in the other. Finally, the author also treat the case of a tandem source and receiver at fixed separation traversing a single hole. In all cases the conductive fracture zone is not intersected by either hole. Comparisons between the grounded electric dipole and the vertical magnetic dipole indicate clear advantages for the former

  2. Basic principles of applied nuclear techniques

    International Nuclear Information System (INIS)

    Basson, J.K.

    1976-01-01

    The technological applications of radioactive isotopes and radiation in South Africa have grown steadily since the first consignment of man-made radioisotopes reached this country in 1948. By the end of 1975 there were 412 authorised non-medical organisations (327 industries) using hundreds of sealed sources as well as their fair share of the thousands of radioisotope consignments, annually either imported or produced locally (mainly for medical purposes). Consequently, it is necessary for South African technologists to understand the principles of radioactivity in order to appreciate the industrial applications of nuclear techniques [af

  3. Principles, Techniques, and Applications of Tissue Microfluidics

    Science.gov (United States)

    Wade, Lawrence A.; Kartalov, Emil P.; Shibata, Darryl; Taylor, Clive

    2011-01-01

    The principle of tissue microfluidics and its resultant techniques has been applied to cell analysis. Building microfluidics to suit a particular tissue sample would allow the rapid, reliable, inexpensive, highly parallelized, selective extraction of chosen regions of tissue for purposes of further biochemical analysis. Furthermore, the applicability of the techniques ranges beyond the described pathology application. For example, they would also allow the posing and successful answering of new sets of questions in many areas of fundamental research. The proposed integration of microfluidic techniques and tissue slice samples is called "tissue microfluidics" because it molds the microfluidic architectures in accordance with each particular structure of each specific tissue sample. Thus, microfluidics can be built around the tissues, following the tissue structure, or alternatively, the microfluidics can be adapted to the specific geometry of particular tissues. By contrast, the traditional approach is that microfluidic devices are structured in accordance with engineering considerations, while the biological components in applied devices are forced to comply with these engineering presets.

  4. Principles of management of open fractures | Buteera | East and ...

    African Journals Online (AJOL)

    Journal Home > Vol 14, No 2 (2009) > ... Background: Open fractures are known orthopedic emergencies associated with risk of infection and healing problems. ... The goals of management of open fractures are prevention of infection, ...

  5. Application of fracture-mechanics principles to austenitic steels

    International Nuclear Information System (INIS)

    Schwalbe, K.H.; Cornec, A.; Baustian, K.

    1996-01-01

    Recent experimental and analytical work mainly carried out at GKSS and TH Darmstadt is used to check the usefulness of fracture mechanics methods as developed for more conventional materials, such as ferritic steels and aluminium alloys. Finite element calculations serve for quantifying J validity limits; they are a function of constraint conditions and strain hardening properties. Crack growth studies show the ability of the J-integral, the modified J-integral, J(M), and of the crack tip opening displacement, CTOD delta(5), to generate unique, i.e. size-independent, R-curves. It is also shown that the delta(5)-type CTOD technique yields values close to the standardised CTOD. Finally, the Engineering Treatment Model is used to estimate delta(5) and J as driving force parameters. Special attention is given to the power law representation of actual stress/strain curves. (author)

  6. New technique for fixing rib fracture with bioabsorbable plate.

    Science.gov (United States)

    Oyamatsu, Hironori; Ohata, Norihisa; Narita, Kunio

    2016-09-01

    Fixation of a bone fracture with a bioabsorbable plate made of poly-L-lactide and hydroxyapatite has received attention. We adopted this technique for a rib fracture by bending the plate into a U-shape and fixing it with suture through the holes in the mesh of the plate and holes that are drilled in the edge of the fractured rib. The suture is also wound around the plate. © The Author(s) 2016.

  7. Sliding contact fracture of dental ceramics: Principles and validation

    Science.gov (United States)

    Ren, Linlin; Zhang, Yu

    2014-01-01

    Ceramic prostheses are subject to sliding contact under normal and tangential loads. Accurate prediction of the onset of fracture at two contacting surfaces holds the key to greater long-term performance of these prostheses. In this study, building on stress analysis of Hertzian contact and considering fracture criteria for linear elastic materials, a constitutive fracture mechanics relation was developed to incorporate the critical fracture load with the contact geometry, coefficient of friction and material fracture toughness. Critical loads necessary to cause fracture under a sliding indenter were calculated from the constitutive equation, and compared with the loads predicted from elastic stress analysis in conjunction with measured critical load for frictionless normal contact—a semi-empirical approach. The major predictions of the models were calibrated with experimentally determined critical loads of current and future dental ceramics after contact with a rigid spherical slider. Experimental results conform with the trends predicted by the models. PMID:24632538

  8. Pie technique of LWR fuel cladding fracture toughness test

    International Nuclear Information System (INIS)

    Endo, Shinya; Usami, Koji; Nakata, Masahito; Fukuda, Takuji; Numata, Masami; Kizaki, Minoru; Nishino, Yasuharu

    2006-01-01

    Remote-handling techniques were developed by cooperative research between the Department of Hot Laboratories in the Japan Atomic Energy Research Institute (JAERI) and the Nuclear Fuel Industries Ltd. (NFI) for evaluating the fracture toughness on irradiated LWR fuel cladding. The developed techniques, sample machining by using the electrical discharge machine (EDM), pre-cracking by fatigue tester, sample assembling to the compact tension (CT) shaped test fixture gave a satisfied result for a fracture toughness test developed by NFL. And post-irradiation examination (PIE) using the remote-handling techniques were carried out to evaluate the fracture toughness on BWR spent fuel cladding in the Waste Safety Testing Facility (WASTEF). (author)

  9. Operative Fixation of Rib Fractures Indications, Techniques, and Outcomes.

    Science.gov (United States)

    Galos, David; Taylor, Benjamin; McLaurin, Toni

    2017-01-01

    Rib fractures are extremely common injuries and vary in there severity from single nondisplaced fractures to multiple segmental fractures resulting in flail chest and respiratory compromise. Historically, rib fractures have been treated conservatively with pain control and respiratory therapy. However this method may not be the best treatment modality in all situations. Operative fixation of select rib fractures has been increasing in popularity especially in patients with flail chest and respiratory compromise. Newer techniques use muscle sparing approaches and precontoured locking plate technology to obtain stable fixation and allow improved respiration. Current reports shows that rib fracture fixation offers the benefits of improved respiratory mechanics and improved pain control in the severe chest wall injury with resultant improvement in patient outcomes by decreasing time on the ventilator, time in the intensive care unit, and overall hospital length of stay.

  10. FEL-principles, techniques and its progress

    International Nuclear Information System (INIS)

    Zhao Xiaofeng; Yang Fujia

    1992-01-01

    The basic principles of free electron laser (FEL) and its operation modes are presented. The state of the art is described for accelerator technology and laser systems. Some comparisons are made between FEL and conventional laser with regard to power capability, short-wavelength operation, and tunability. The application prospects of FEL are discussed

  11. Magnetism in meteorites. [terminology, principles and techniques

    Science.gov (United States)

    Herndon, J. M.; Rowe, M. W.

    1974-01-01

    An overview of this subject is presented. The paper includes a glossary of magnetism terminology and a discussion of magnetic techniques used in meteorite research. These techniques comprise thermomagnetic analysis, alternating field demagnetization, thermal demagnetization, magnetic anisotropy, low-temperature cycling, and coercive forces, with emphasis on the first method. Limitations on the validity of paleointensity determinations are also discussed.

  12. Fracture properties of ThO2-UO2 pellets by Hertzian indentation technique

    International Nuclear Information System (INIS)

    Kutty, T.R.G.; Rath, B.N.; Balakrishnan, K.S.

    2005-01-01

    Fracture toughness (K Ic ) and fracture surface energy (γ s ) of ThO 2 -UO 2 pellets with varying UO 2 contents were measured using Hertzian indentation technique. The knowledge of fracture toughness (K Ic ) and fracture surface energy values are important for fuel designers since these values are used in fuel modeling. Cracks in nuclear fuel act as a path for fission gas release and enhances fuel cladding mechanical interaction. Microstructural features like grain size and presence of second phase play a significant role in controlling the fracture behavior. Since the fracture properties of nuclear materials are of primary design consideration, it is important that these properties should be evaluated with good precision. There have been several attempts to use Hertzian indentation for evaluating the fracture toughness of brittle materials. The main principle of this method depends on the interaction of the elastic stress field with a pre-existing surface flaw of the sample. One significant advantage of Hertzian indentation over that of Vickers is that the substrate's deformation is entirely elastic until fracture occurs. This avoids the complications arising from the ill-defined residual stress that is normally associated with indentations brought about by pointed indenters like that of Vickers. The material properties that may be determined by this test include (a) fracture toughness and fracture surface energy of the near surface material, (b) the densities and sizes of surface cracks, and (c) residual stresses in the near surface material. This paper deals with experimental procedure for the evaluation of fracture properties of ThO 2 -UO 2 of varying U content and results thus obtained are also presented. The K Ic values thus obtained are explained in terms of their microstructures and the U content. (author)

  13. Estimation of fracture aperture using simulation technique; Simulation wo mochiita fracture kaiko haba no suitei

    Energy Technology Data Exchange (ETDEWEB)

    Kikuchi, T [Geological Survey of Japan, Tsukuba (Japan); Abe, M [Tohoku University, Sendai (Japan). Faculty of Engineering

    1996-10-01

    Characteristics of amplitude variation around fractures have been investigated using simulation technique in the case changing the fracture aperture. Four models were used. The model-1 was a fracture model having a horizontal fracture at Z=0. For the model-2, the fracture was replaced by a group of small fractures. The model-3 had an extended borehole diameter at Z=0 in a shape of wedge. The model-4 had a low velocity layer at Z=0. The maximum amplitude was compared each other for each depth and for each model. For the model-1, the amplitude became larger at the depth of the fracture, and became smaller above the fracture. For the model-2, when the cross width D increased to 4 cm, the amplitude approached to that of the model-1. For the model-3 having extended borehole diameter, when the extension of borehole diameter ranged between 1 cm and 2 cm, the change of amplitude was hardly observed above and below the fracture. However, when the extension of borehole diameter was 4 cm, the amplitude became smaller above the extension part of borehole. 3 refs., 4 figs., 1 tab.

  14. Imaging techniques for the assessment of fracture repair.

    Science.gov (United States)

    Augat, P; Morgan, E F; Lujan, T J; MacGillivray, T J; Cheung, W H

    2014-06-01

    Imaging of a healing fracture provides a non-invasive and often instructive reproduction of the fracture repair progress and the healing status of bone. However, the interpretation of this reproduction is often qualitative and provides only an indirect and surrogate measure of the mechanical stability of the healing fracture. Refinements of the available imaging techniques have been suggested to more accurately determine the healing status of bone. Plain radiographs provide the ability to determine the degree of bridging of the fracture gap and to quantify the amount of periosteal callus formation. Absorptiometric measures including dual X-ray absorptiometry and computed tomography provide quantitative information on the amount and the density of newly formed bone around the site of the fracture. To include the effect of spatial distribution of newly formed bone, finite element models of healing fracture can be employed to estimate its load bearing capacity. Ultrasound technology not only avoids radiation doses to the patients but also provides the ability to additionally measure vascularity in the surrounding soft tissue of the fracture and in the fracture itself. Copyright © 2014 Elsevier Ltd. All rights reserved.

  15. Subbrow Approach as a Minimally Invasive Reduction Technique in the Management of Frontal Sinus Fractures

    Directory of Open Access Journals (Sweden)

    Yewon Lee

    2014-11-01

    Full Text Available BackgroundFrontal sinus fractures, particularly anterior sinus fractures, are relatively common facial fractures. Many agree on the general principles of frontal fracture management; however, the optimal methods of reduction are still controversial. In this article, we suggest a simple reduction method using a subbrow incision as a treatment for isolated anterior sinus fractures.MethodsBetween March 2011 and March 2014, 13 patients with isolated frontal sinus fractures were treated by open reduction and internal fixation through a subbrow incision. The subbrow incision line was designed to be precisely at the lower margin of the brow in order to obtain an inconspicuous scar. A periosteal incision was made at 3 mm above the superior orbital rim. The fracture site of the frontal bone was reduced, and bone fixation was performed using an absorbable plate and screws.ResultsContour deformities were completely restored in all patients, and all patients were satisfied with the results. Scars were barely visible in the long-term follow-up. No complications related to the procedure, such as infection, uncontrolled sinus bleeding, hematoma, paresthesia, mucocele, or posterior wall and brain injury were observed.ConclusionsThe subbrow approach allowed for an accurate reduction and internal fixation of the fractures in the anterior table of the frontal sinus by providing a direct visualization of the fracture. Considering the surgical success of the reduction and the rigid fixation, patient satisfaction, and aesthetic problems, this transcutaneous approach through a subbrow incision is concluded to be superior to the other reduction techniques used in the case of an anterior table frontal sinus fracture.

  16. Comparison of surgical techniques of 111 medial malleolar fractures classified by fracture geometry.

    Science.gov (United States)

    Ebraheim, Nabil A; Ludwig, Todd; Weston, John T; Carroll, Trevor; Liu, Jiayong

    2014-05-01

    Evaluation of operative techniques used for medial malleolar fractures by classifying fracture geometry has not been well documented. One hundred eleven patients with medial malleolar fractures (transverse n = 63, oblique n = 29, vertical n = 7, comminuted n = 12) were included in this study. Seventy-two patients had complicating comorbidities. All patients were treated with buttress plate, lag screw, tension band, or K-wire fixation. Treatment outcomes were evaluated on the basis of radiological outcome (union, malunion, delayed union, or nonunion), need for operative revision, presence of postoperative complications, and AOFAS Ankle-Hindfoot score. For transverse fractures, tension band fixation showed the highest rate of union (79%), highest average AOFAS score (86), lowest revision rate (5%), and lowest complication rate (16%). For oblique fractures, lag screws showed the highest rate of union (71%), highest average AOFAS score (80), lowest revision rate (19%), and lowest complication rate (33%) of the commonly used fixation techniques. For vertical fractures, buttress plating was used in every case but 1, achieving union (whether normal or delayed) in all cases with an average AOFAS score of 84, no revisions, and a 17% complication rate. Comminuted fractures had relatively poor outcomes regardless of fixation method. The results of this study suggest that both tension bands and lag screws result in similar rates of union for transverse fractures of the medial malleolus, but that tension band constructs are associated with less need for revision surgery and fewer complications. In addition, our data demonstrate that oblique fractures were most effectively treated with lag screws and that vertical fractures attained superior outcomes with buttress plating. Level III, retrospective comparative series.

  17. First principles characterisation of brittle transgranular fracture of titanium hydrides

    International Nuclear Information System (INIS)

    Olsson, Pär A.T.; Mrovec, Matous; Kroon, Martin

    2016-01-01

    In this work we have studied transgranular cleavage and the fracture toughness of titanium hydrides by means of quantum mechanical calculations based on density functional theory. The calculations show that the surface energy decreases and the unstable stacking fault energy increases with increasing hydrogen content. This is consistent with experimental findings of brittle behaviour of titanium hydrides at low temperatures. Based on Griffith-Irwin theory we estimate the fracture toughness of the hydrides to be of the order of 1 MPa⋅m"1"/"2, which concurs well with experimental data. To investigate the cleavage energetics, we analyse the decohesion at various crystallographic planes and determine the traction-separation laws based on the Rose's extended universal binding energy relation. The calculations predict that the peak stresses do not depend on the hydrogen content of the phases, but it is rather dependent on the crystallographic cleavage direction. However, it is found that the work of fracture decreases with increasing hydrogen content, which is an indication of hydrogen induced bond weakening in the material.

  18. Fracture toughness testing on ferritic alloys using the electropotential technique

    International Nuclear Information System (INIS)

    Huang, F.H.; Wire, G.L.

    1981-01-01

    Fracture toughness measurements as done conventionally require large specimens (5 x 5 x 2.5 cm) which would be prohibitively expensive to irradiate over the fluence and temperature ranges required for first wall design. To overcome this difficulty a single specimen technique for J intergral fracture toughness measurements on miniature specimens (1.6 cm OD x 0.25 cm thick) was developed. Comparisons with specimens three times as thick show that the derived J/sub 1c/ is constant, validating the specimen for first wall applications. The electropotential technique was used to obtain continuous crack extension measurements, allowing a ductile fracture resistence curve to be constructed from a single specimen. The irradiation test volume required for fracture toughness measurements using both miniature specimens and single specimen J measurements was reduced a factor of 320, making it possible to perform a systematic exploration of irradiation temperature and dose variables as required for qualification of HT-9 and 9Cr-1Mo base metal and welds for first wall application. Fracture toughness test results for HT-9 and 9Cr-1Mo from 25 to 539 0 C are presented to illustrate the single specimen technique

  19. The laser principles and application techniques. 2. ed.

    International Nuclear Information System (INIS)

    Maillet, H.

    1986-01-01

    Specialists of each field gathered to give a complete overview of laser techniques possibilities. Operation principles, properties and the different kinds of lasers are detailed. Inertial fusion, isotope separation, medecine are part of the laser application fields presented, and application techniques in these fields are described [fr

  20. Safe surgical technique: intramedullary nail fixation of tibial shaft fractures.

    Science.gov (United States)

    Zelle, Boris A; Boni, Guilherme

    2015-01-01

    Statically locked, reamed intramedullary nailing remains the standard treatment for displaced tibial shaft fractures. Establishing an appropriate starting point is a crucial part of the surgical procedure. Recently, suprapatellar nailing in the semi-extended position has been suggested as a safe and effective surgical technique. Numerous reduction techiques are available to achieve an anatomic fracture alignment and the treating surgeon should be familiar with these maneuvers. Open reduction techniques should be considered if anatomic fracture alignment cannot be achieved by closed means. Favorable union rates above 90 % can be achieved by both reamed and unreamed intramedullary nailing. Despite favorable union rates, patients continue to have functional long-term impairments. In particular, anterior knee pain remains a common complaint following intramedullary tibial nailing. Malrotation remains a commonly reported complication after tibial nailing. The effect of postoperative tibial malalignment on the clinical and radiographic outcome requires further investigation.

  1. Application of simulation techniques in the probabilistic fracture mechanics

    International Nuclear Information System (INIS)

    De Ruyter van Steveninck, J.L.

    1995-03-01

    The Monte Carlo simulation is applied on a model of the fracture mechanics in order to assess the applicability of this simulation technique in the probabilistic fracture mechanics. By means of the fracture mechanics model the brittle fracture of a steel container or pipe with defects can be predicted. By means of the Monte Carlo simulation also the uncertainty regarding failures can be determined. Based on the variations in the toughness of the fracture and the defect dimensions the distribution of the chance of failure is determined. Also attention is paid to the impact of dependency between uncertain variables. Furthermore, the influence of the applied distributions of the uncertain variables and non-destructive survey on the chance of failure is analyzed. The Monte Carlo simulation results agree quite well with the results of other methods from the probabilistic fracture mechanics. If an analytic expression can be found for the chance of failure, it is possible to determine the variation of the chance of failure, next to an estimation of the chance of failure. It also appears that the dependency between the uncertain variables has a large impact on the chance of failure. It is also concluded from the simulation that the chance of failure strongly depends on the crack depth, and therefore of the distribution of the crack depth. 15 figs., 7 tabs., 12 refs

  2. Development of Reservoir Characterization Techniques and Production Models for Exploiting Naturally Fractured Reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Wiggins, Michael L.; Brown, Raymon L.; Civan, Frauk; Hughes, Richard G.

    2001-08-15

    Research continues on characterizing and modeling the behavior of naturally fractured reservoir systems. Work has progressed on developing techniques for estimating fracture properties from seismic and well log data, developing naturally fractured wellbore models, and developing a model to characterize the transfer of fluid from the matrix to the fracture system for use in the naturally fractured reservoir simulator.

  3. Modelling of 3D fractured geological systems - technique and application

    Science.gov (United States)

    Cacace, M.; Scheck-Wenderoth, M.; Cherubini, Y.; Kaiser, B. O.; Bloecher, G.

    2011-12-01

    All rocks in the earth's crust are fractured to some extent. Faults and fractures are important in different scientific and industry fields comprising engineering, geotechnical and hydrogeological applications. Many petroleum, gas and geothermal and water supply reservoirs form in faulted and fractured geological systems. Additionally, faults and fractures may control the transport of chemical contaminants into and through the subsurface. Depending on their origin and orientation with respect to the recent and palaeo stress field as well as on the overall kinematics of chemical processes occurring within them, faults and fractures can act either as hydraulic conductors providing preferential pathways for fluid to flow or as barriers preventing flow across them. The main challenge in modelling processes occurring in fractured rocks is related to the way of describing the heterogeneities of such geological systems. Flow paths are controlled by the geometry of faults and their open void space. To correctly simulate these processes an adequate 3D mesh is a basic requirement. Unfortunately, the representation of realistic 3D geological environments is limited by the complexity of embedded fracture networks often resulting in oversimplified models of the natural system. A technical description of an improved method to integrate generic dipping structures (representing faults and fractures) into a 3D porous medium is out forward. The automated mesh generation algorithm is composed of various existing routines from computational geometry (e.g. 2D-3D projection, interpolation, intersection, convex hull calculation) and meshing (e.g. triangulation in 2D and tetrahedralization in 3D). All routines have been combined in an automated software framework and the robustness of the approach has been tested and verified. These techniques and methods can be applied for fractured porous media including fault systems and therefore found wide applications in different geo-energy related

  4. Appropriate electromagnetic techniques for imaging geothermal fracture zones

    Energy Technology Data Exchange (ETDEWEB)

    Groom, R; Walker, P [PetRos EiKon Incorporated, Ontario (Canada)

    1996-05-01

    Electromagnetic surface detection of fracture zones has often been approached by using the magnetotelluric method. This technique suffers greatly from the quantity and scale of the conductive inhomogeneities lying above the fracture zones. Additionally, it suffers from the inherent inability to focus the source on the target. There are no such source focusing capabilities in magnetotellurics. Accordingly, the quantity of magnetotelluric data required to resolve targets in such complex conditions can make the technique inefficient and insufficient from a cost perspective. When attempting to reveal a subsurface structure and image it, the basic physical responses at hand must be kept in mind, and the appropriate source must be utilized, which most effectively illuminates the target. A further advantage to controlled sources is that imaging techniques may be used to accentuate the response due to knowledge and control of the source.

  5. Determination of dynamic fracture toughness using a new experimental technique

    Directory of Open Access Journals (Sweden)

    Cady Carl M.

    2015-01-01

    Full Text Available In other studies dynamic fracture toughness has been measured using Charpy impact and modified Hopkinson Bar techniques. In this paper results will be shown for the measurement of fracture toughness using a new test geometry. The crack propagation velocities range from ∼0.15 mm/s to 2.5 m/s. Digital image correlation (DIC will be the technique used to measure both the strain and the crack growth rates. The boundary of the crack is determined using the correlation coefficient generated during image analysis and with interframe timing the crack growth rate and crack opening can be determined. A comparison of static and dynamic loading experiments will be made for brittle polymeric materials. The analysis technique presented by Sammis et al. [1] is a semi-empirical solution, however, additional Linear Elastic Fracture Mechanics analysis of the strain fields generated as part of the DIC analysis allow for the more commonly used method resembling the crack tip opening displacement (CTOD experiment. It should be noted that this technique was developed because limited amounts of material were available and crack growth rates were to fast for a standard CTOD method.

  6. Determination of dynamic fracture toughness using a new experimental technique

    Science.gov (United States)

    Cady, Carl M.; Liu, Cheng; Lovato, Manuel L.

    2015-09-01

    In other studies dynamic fracture toughness has been measured using Charpy impact and modified Hopkinson Bar techniques. In this paper results will be shown for the measurement of fracture toughness using a new test geometry. The crack propagation velocities range from ˜0.15 mm/s to 2.5 m/s. Digital image correlation (DIC) will be the technique used to measure both the strain and the crack growth rates. The boundary of the crack is determined using the correlation coefficient generated during image analysis and with interframe timing the crack growth rate and crack opening can be determined. A comparison of static and dynamic loading experiments will be made for brittle polymeric materials. The analysis technique presented by Sammis et al. [1] is a semi-empirical solution, however, additional Linear Elastic Fracture Mechanics analysis of the strain fields generated as part of the DIC analysis allow for the more commonly used method resembling the crack tip opening displacement (CTOD) experiment. It should be noted that this technique was developed because limited amounts of material were available and crack growth rates were to fast for a standard CTOD method.

  7. Minimally invasive tension band wiring technique for olecranon fractures.

    Science.gov (United States)

    Takada, Naoya; Kato, Kenji; Fukuta, Makoto; Wada, Ikuo; Otsuka, Takanobu

    2013-12-01

    Some types of implants, such as plates, screws, wires, and nails, have been used for open reduction and internal fixation of olecranon fractures. A ≥ 10 cm longitudinal incision is used for open reduction and internal fixation of olecranon fractures. According to previous studies, tension band wiring is a popular method that gives good results. However, back out of the wires after the surgery is one of the main postoperative complications. Moreover, if the Kirschner wires are inserted through the anterior ulnar cortex, they may impinge on the radial neck, supinator muscle, or biceps tendon. Herein, we describe the minimally invasive tension band wiring technique using Ring-Pin. This technique can be performed through a 2 cm incision. Small skin incisions are advantageous from an esthetic viewpoint. Ring-Pin was fixed by using a dedicated cable wire that does not back out unless the cable wire breaks or slips out of the dedicated metallic clamp. As the pins are placed in intramedullary canal, this technique does not lead to postoperative complications that may occur after transcortical fixation by conventional tension band wiring. Minimally invasive tension band wiring is one of the useful options for the treatment of olecranon fractures with some advantages.

  8. Posterior coronal plating for tibial fractures: technique and advantages

    Directory of Open Access Journals (Sweden)

    Montu Jain

    2014-04-01

    Full Text Available Objective:Tibial shaft fractures are straightforward to treat but when associated with soft tissue injury particularly at the nail entry/plate insertion site or there is significant comminution proximally or a large butterfly fragment/a second split component in the posterior coronal plane, it is a challenge to the treating surgeon. The aim of the present report is to describe the technique of posterior coronal plating in such a scenario and its advantages. Methods:Between July 2008 and June 2011, 12 patients were pro spectively treated by this approach using 4.5 mm broad dynamic compression plates. Results:The time of bony consolidation and full weight bearing averaged 21.7 weeks (range, 16-26 weeks. Patients were followed up for at least 24 months (range, 24-48 months. At 1 year postoper atively, no loss in reduction or alignment was observed. Mean Hospital for Lower Extremity Measurement Functional Score was 72.8 (range, 64-78. All patients were satisfied with their treatment outcomes. Conclusion:Direct posterior approach and fixation using prone position helps to visualise the fracture fragments and provide rigid fixation. The approach is simple and extensile easily, apart from advantages of less soft tissue and hardware problems compared to standard medial or lateral plating. Key words: Tibial fractures; Bone plates; Orthopedic procedures

  9. A novel MIS technique for posterior cruciate ligament avulsion fractures.

    Science.gov (United States)

    Gavaskar, Ashok S; Karthik, Bhupesh; Gopalan, Hitesh; Srinivasan, Parthasarathy; Tummala, Naveen C

    2017-08-01

    Open surgical approaches to treat tibial avulsion fractures of the posterior cruciate ligament (PCL) often use large incisions involving extensive muscle dissection and retraction. The objective of this study was to describe a new mini-invasive approach targeting the fractured zone, to minimize surgical dissection and improve recovery and rehabilitation. The new approach was used in 15 males and seven females with isolated PCL avulsions. The length of the surgical incision, surgical time, need for conversion to open technique, visual analog scores (VAS) and duration of hospital stay were studied to assess the efficacy, learning curve and advantages of the new technique. Neurovascular complications were recorded. At the two-year follow-up, International Knee Documentation Committee (IKDC) scores were recorded to assess function. Patients were followed up for a mean of 29months (range: 34-41). The mean length of the incision was 4.1cm (range: 3.4 to five) measured at the end of the procedure. None of the patients required conversion to an open technique and no neurovascular complications were recorded. The mean surgical time was 40min (range: 25-50). The mean VAS on discharge was 2.2 (range: one to four) and patients stayed at the hospital for a mean of 2.2days (range: one to three). The mean IKDC score at one-year post surgery was 86.4 (range: 83.9-90.8). The new mini-invasive targeted approach provides adequate exposure for performing internal fixation of PCL avulsion fractures without the surgical morbidity associated with conventional open surgical approaches. The procedure is safe, fast and does not require a long learning curve. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. A new technique in the surgical treatment of Hangman's fractures: Neurospinal Academy (NSA) technique.

    Science.gov (United States)

    Dalbayrak, Sedat; Yaman, Onur; Yılmaz, Mesut

    2013-07-01

    Treatment of Hangman's fractures is still controversial. Hangman's fractures Type II and IIA are usually treated with surgical procedures. This study aims at describing the Neurospinal Academy (NSA) technique as an attempt to achieve an approximation of the fracture line to the axis body, which may be used for Type II and IIA patients with severe displacement and angulation. NSA technique both pars or pedicle screws are placed bicortically to ensure that anterior surface of C2 vertebral body will be crossed 1-2 mm. A rod is prepared in suitable length and curve to connect the two screws. For placing the rod, sufficient amount of bone is resected from the C2 spinous process. C2 vertebral body is pulled back by means of the screws that crossed the anterior surface of C2 vertebral body. Hangman II and IIA patient are treated with NSA technique. Angulated and tilted C2 vertebral body was pulled back and approximated to posterior elements. In Hangman's fractures Type II and IIA with severe vertebral body and pedicle displacement, NSA technique is an effective and reliable treatment alternative for the approximation of posterior elements to the C2 vertebral body, which is tilted, angulated, and dislocated.

  11. A new technique in the surgical treatment of Hangman′s fractures: Neurospinal Academy (NSA technique

    Directory of Open Access Journals (Sweden)

    Sedat Dalbayrak

    2013-01-01

    Full Text Available Context: Treatment of Hangman′s fractures is still controversial. Hangman′s fractures Type II and IIA are usually treated with surgical procedures. Aim: This study aims at describing the Neurospinal Academy (NSA technique as an attempt to achieve an approximation of the fracture line to the axis body, which may be used for Type II and IIA patients with severe displacement and angulation. Settings and Design: NSA technique both pars or pedicle screws are placed bicortically to ensure that anterior surface of C2 vertebral body will be crossed 1-2 mm. A rod is prepared in suitable length and curve to connect the two screws. For placing the rod, sufficient amount of bone is resected from the C2 spinous process. C2 vertebral body is pulled back by means of the screws that crossed the anterior surface of C2 vertebral body. Materials and Methods: Hangman II and IIA patient are treated with NSA technique. Result: Angulated and tilted C2 vertebral body was pulled back and approximated to posterior elements. Conclusions: In Hangman′s fractures Type II and IIA with severe vertebral body and pedicle displacement, NSA technique is an effective and reliable treatment alternative for the approximation of posterior elements to the C2 vertebral body, which is tilted, angulated, and dislocated.

  12. Basic principles of Hasse diagram technique in chemistry.

    Science.gov (United States)

    Brüggemann, Rainer; Voigt, Kristina

    2008-11-01

    Principles of partial order applied to ranking are explained. The Hasse diagram technique (HDT) is the application of partial order theory based on a data matrix. In this paper, HDT is introduced in a stepwise procedure, and some elementary theorems are exemplified. The focus is to show how the multivariate character of a data matrix is realized by HDT and in which cases one should apply other mathematical or statistical methods. Many simple examples illustrate the basic theoretical ideas. Finally, it is shown that HDT is a useful alternative for the evaluation of antifouling agents, which was originally performed by amoeba diagrams.

  13. Principle of the electrically induced Transient Current Technique

    Science.gov (United States)

    Bronuzzi, J.; Moll, M.; Bouvet, D.; Mapelli, A.; Sallese, J. M.

    2018-05-01

    In the field of detector development for High Energy Physics, the so-called Transient Current Technique (TCT) is used to characterize the electric field profile and the charge trapping inside silicon radiation detectors where particles or photons create electron-hole pairs in the bulk of a semiconductor device, as PiN diodes. In the standard approach, the TCT signal originates from the free carriers generated close to the surface of a silicon detector, by short pulses of light or by alpha particles. This work proposes a new principle of charge injection by means of lateral PN junctions implemented in one of the detector electrodes, called the electrical TCT (el-TCT). This technique is fully compatible with CMOS technology and therefore opens new perspectives for assessment of radiation detectors performances.

  14. MR enterography in children: Principles, technique, and clinical applications

    International Nuclear Information System (INIS)

    Chavhan, Govind B; Babyn, Paul S; Walters, Thomas

    2013-01-01

    MR enterography is a constantly advancing technique for assessment of bowel with newer technology and sequences. It is being increasingly used for the assessment of inflammatory bowel disease and has almost replaced barium follow through examinations in many institutions. Its lack of radiation makes it an attractive alternative for bowel evaluation in children. It has been proved to be highly sensitive in the detection of Crohn disease in adults and children. It is also superior to barium studies in showing extra-enteric findings and detecting complications such as fistulas and abscesses. Even though at present it is almost exclusively used for the evaluation of inflammatory bowel disease, it has the potential to be used in other conditions affecting the bowel. The principles, MR enterography technique pertinent to children, and its utility in the assessment of Crohn disease in children are discussed in this review

  15. A computational technique to measure fracture callus in radiographs.

    Science.gov (United States)

    Lujan, Trevor J; Madey, Steven M; Fitzpatrick, Dan C; Byrd, Gregory D; Sanderson, Jason M; Bottlang, Michael

    2010-03-03

    Callus formation occurs in the presence of secondary bone healing and has relevance to the fracture's mechanical environment. An objective image processing algorithm was developed to standardize the quantitative measurement of periosteal callus area in plain radiographs of long bone fractures. Algorithm accuracy and sensitivity were evaluated using surrogate models. For algorithm validation, callus formation on clinical radiographs was measured manually by orthopaedic surgeons and compared to non-clinicians using the algorithm. The algorithm measured the projected area of surrogate calluses with less than 5% error. However, error will increase when analyzing very small areas of callus and when using radiographs with low image resolution (i.e. 100 pixels per inch). The callus size extracted by the algorithm correlated well to the callus size outlined by the surgeons (R2=0.94, p<0.001). Furthermore, compared to clinician results, the algorithm yielded results with five times less inter-observer variance. This computational technique provides a reliable and efficient method to quantify secondary bone healing response. Copyright 2009 Elsevier Ltd. All rights reserved.

  16. Techniques and principles of endoscopic treatment of benign gastrointestinal strictures.

    Science.gov (United States)

    Irani, Shayan; Kozarek, Richard A

    2015-09-01

    The fundamental goal of treating any stenosis is luminal enlargement to ameliorate the underlying obstructive symptoms. Symptoms depend on the etiology and the site of the stricture and may include dysphagia, nausea and vomiting, abdominal pain, obstipation, or frank bowel obstruction. This article compares the various current technologies available for the treatment of gastrointestinal stenoses with regard to ease and site of application, patient tolerance, safety and efficacy data, and cost-benefit ratio. Recent studies indicate that gastrointestinal dilation and stenting have evolved to a point at which in many if not most situations they can be the first line therapy and potentially the final therapy needed to treat the underlying condition. Following techniques and principles in the management of gastrointestinal strictures would allow for the well tolerated and effective treatment of most patients with the tools currently available today.

  17. Ultrasound-guided genitourinary interventions: principles and techniques

    Directory of Open Access Journals (Sweden)

    Byung Kwan Park

    2017-10-01

    Full Text Available Ultrasound (US is often used to guide various interventional procedures in the genitourinary (GU tract because it can provide real-time imaging without any radiation hazard. Moreover, US can clearly visualize the pathway of an aspiration or biopsy needle to ensure the safety of the intervention. US guidance also helps clinicians to access lesions via the transabdominal, transhepatic, transvaginal, transrectal, and transperineal routes. Hence, US-guided procedures are useful for radiologists who wish to perform GU interventions. However, US-guided procedures and interventions are difficult for beginners because they involve a steep initial learning curve. The purpose of this review is to describe the basic principles and techniques of US-guided GU interventions.

  18. Ultrasound-guided genitourinary interventions: principles and techniques

    Energy Technology Data Exchange (ETDEWEB)

    Park, Byung Kwan [Dept. of Radiology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of)

    2017-10-15

    Ultrasound (US) is often used to guide various interventional procedures in the genitourinary (GU) tract because it can provide real-time imaging without any radiation hazard. Moreover, US can clearly visualize the pathway of an aspiration or biopsy needle to ensure the safety of the intervention. US guidance also helps clinicians to access lesions via the transabdominal, transhepatic, transvaginal, transrectal, and transperineal routes. Hence, US-guided procedures are useful for radiologists who wish to perform GU interventions. However, US-guided procedures and interventions are difficult for beginners because they involve a steep initial learning curve. The purpose of this review is to describe the basic principles and techniques of US-guided GU interventions.

  19. Digital holography and wavefront sensing principles, techniques and applications

    CERN Document Server

    Schnars, Ulf; Watson, John; Jüptner, Werner

    2015-01-01

    This book presents a self-contained treatment of the principles and major applications of digital hologram recording and numerical reconstruction (Digital Holography). This second edition has been significantly revised and enlarged. The authors have extended the chapter on Digital Holographic Microscopy to incorporate new sections on particle sizing, particle image velocimetry and underwater holography. A new chapter now deals comprehensively and extensively with computational wave field sensing. These techniques represent a fascinating alternative to standard interferometry and Digital Holography. They enable wave field sensing without the requirement of a particular reference wave, thus allowing the use of low brilliance light sources and even liquid-crystal displays (LCD) for interferometric applications.              

  20. Application of Phase-Field Techniques to Hydraulically- and Deformation-Induced Fracture.

    Energy Technology Data Exchange (ETDEWEB)

    Culp, David [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Miller, Nathan [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Schweizer, Laura [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-08-01

    Phase-field techniques provide an alternative approach to fracture problems which mitigate some of the computational expense associated with tracking the crack interface and the coalescence of individual fractures. The technique is extended to apply to hydraulically driven fracture such as would occur during fracking or CO2 sequestration. Additionally, the technique is applied to a stainless steel specimen used in the Sandia Fracture Challenge. It was found that the phase-field model performs very well, at least qualitatively, in both deformation-induced fracture and hydraulically-induced fracture, though spurious hourglassing modes were observed during coupled hydralically-induced fracture. Future work would include performing additional quantitative benchmark tests and updating the model as needed.

  1. Skin carcinomas: Radiobiological principles, radiotherapeutic techniques and clinical management

    International Nuclear Information System (INIS)

    Schmidt-Ullrich, Rupert K.; Johnson, Christopher R.

    1997-01-01

    Purpose/Objective: The course will be divided into three major topics: (1) Review of radiobiological principles as they apply to the radiotherapeutic management of skin carcinomas; (2) review of radiotherapeutic techniques including beam qualities, beam collimation, tissue dose profiles, and the relative indications of external beam irradiation vs. brachytherapy; (3) comprehensive review of the tumor biology of skin malignancies, including malignant melanoma, and of the relative indications for radiotherapeutic and/or surgical management. (1) Review of critical data which have led to currently applied principles of time-dose-volume concepts in the radiotherapeutic management of skin carcinomas. Emphasis will be placed on the relative importance of fraction size and overall treatment time on tumor control probability and acute and late normal tissue toxicity. (2) Considering that radiotherapy in the management of skin carcinomas is often used to minimize patient disfiguration and to preserve critical body functions (e.g. eye lids) the technical aspects of radiotherapy delivery are most critical. Careful evaluation of the extent of the lesions including evaluation of their depth of invasion will determine the quality of the radiation beams, orthovoltage and low energy electrons being the most useful. Beam harding for orthovoltage beams and secondary and tertiary (skin) collimation of appropriate electron beams are critical. For more extensive and deeply invasive lesions contour-shaping through customized bolus material is essential. Equally important is the familiarity with custom shielding of critical structures, such as eyes, ears, oral cavity and central nervous system structures. Brachytherapy applications in the treatment of skin carcinomas is limited but should be considered when implants with high dose uniformity can be constructed. (3) The discussion of clinical management will start with a discussion of properties and routes of spread of the diverse

  2. Skin carcinomas: radiobiological principles, radiotherapeutic techniques and clinical management

    International Nuclear Information System (INIS)

    Schmidt-Ullrich, Rupert K. A.; Johnson, Christopher R.

    1995-01-01

    Purpose/Objective: The course will be divided into three major topics: (1) Review of radiobiological principles as they apply to the radiotherapeutic management of skin carcinomas; (2) review of radiotherapeutic techniques including beam qualities, beam collimation, tissue dose profiles, and the relative indications of external beam irradiation vs. brachytherapy; (3) comprehensive review of the tumor biology of skin malignancies, including malignant melanoma, and of the relative indications for radiotherapeutic and/or surgical management. (1) Review of critical data which have lead to currently applied principles of time-dose-volume concepts in the radiotherapeutic management of skin carcinomas. Emphasis will be placed on the relative importance of fraction size and overall treatment time on tumor control probability and acute and late normal tissue toxicity. (2) Considering that radiotherapy in the management of skin carcinomas is often used to minimize patient disfiguration and to preserve critical body functions (e.g. eye lids) the technical aspects of radiotherapy delivery are most critical. Careful evaluation of the extent of the lesions including evaluation of their depth of invasion will determine the quality of the radiation beams, orthovoltage and low energy electrons being the most useful. Beam harding for orthovoltage beams and secondary and tertiary (skin) collimation of appropriate electron beams are critical. For more extensive and deeply invasive lesions contour-shaping through customized bolus material is essential. Equally important is the familiarity with custom shielding of critical structures, such as eyes, ears, oral cavity and central nervous system structures. Brachytherapy applications in the treatment of skin carcinomas is limited but should be considered when implants with high dose uniformity can be constructed. (3) The discussion of clinical management will start with a discussion of tumor biological properties of the diverse malignant

  3. [Balloon osteoplasty as reduction technique in the treatment of tibial head fractures].

    Science.gov (United States)

    Freude, T; Kraus, T M; Sandmann, G H

    2015-10-01

    Tibial plateau fractures requiring surgery are severe injuries of the lower extremities. Depending on the fracture pattern, the age of the patient, the range of activity and the bone quality there is a broad variation in adequate treatment.  This article reports on an innovative treatment concept to address split depression fractures (Schatzker type II) and depression fractures (Schatzker type III) of the tibial head using the balloon osteoplasty technique for fracture reduction. Using the balloon technique achieves a precise and safe fracture reduction. This internal osteoplasty combines a minimal invasive percutaneous approach with a gently rise of the depressed area and the associated protection of the stratum regenerativum below the articular cartilage surface. This article lights up the surgical procedure using the balloon technique in tibia depression fractures. Using the balloon technique a precise and safe fracture reduction can be achieved. This internal osteoplasty combines a minimally invasive percutaneous approach with a gentle raising of the depressed area and the associated protection of the regenerative layer below the articular cartilage surface. Fracture reduction by use of a tamper results in high peak forces over small areas, whereas by using the balloon the forces are distributed over a larger area causing less secondary stress to the cartilage tissue. This less invasive approach might help to achieve a better long-term outcome with decreased secondary osteoarthritis due to the precise and chondroprotective reduction technique.

  4. Iterative reconstruction techniques for computed tomography Part 1: Technical principles

    International Nuclear Information System (INIS)

    Willemink, Martin J.; Jong, Pim A. de; Leiner, Tim; Nievelstein, Rutger A.J.; Schilham, Arnold M.R.; Heer, Linda M. de; Budde, Ricardo P.J.

    2013-01-01

    To explain the technical principles of and differences between commercially available iterative reconstruction (IR) algorithms for computed tomography (CT) in non-mathematical terms for radiologists and clinicians. Technical details of the different proprietary IR techniques were distilled from available scientific articles and manufacturers' white papers and were verified by the manufacturers. Clinical results were obtained from a literature search spanning January 2006 to January 2012, including only original research papers concerning IR for CT. IR for CT iteratively reduces noise and artefacts in either image space or raw data, or both. Reported dose reductions ranged from 23 % to 76 % compared to locally used default filtered back-projection (FBP) settings, with similar noise, artefacts, subjective, and objective image quality. IR has the potential to allow reducing the radiation dose while preserving image quality. Disadvantages of IR include blotchy image appearance and longer computational time. Future studies need to address differences between IR algorithms for clinical low-dose CT. circle Iterative reconstruction technology for CT is presented in non-mathematical terms. (orig.)

  5. Current techniques for management of transverse displaced olecranon fractures

    NARCIS (Netherlands)

    den Hamer, A.; Heusinkveld, M.H.G.; Traa, W.; Oomen, P.; Oliva, F.; Del Buono, A.; Maffulli, N.

    2015-01-01

    BACKGROUND: displaced transverse fractures of the olecranon are the most common fractures occurring in the elbow in adults that requires operative intervention. METHODS: a literature search was performed on PubMed, Web of Science, Science Direct/Scopus, Google Scholar and Google using the keywords

  6. Using acoustic emission technique to monitor fractures on the analogous pressure pipes

    International Nuclear Information System (INIS)

    Zhang Lichen

    1989-01-01

    By using the acoustic emission technique to monitor the fractures on analogous pressure pipes of the primary circuit which has had cracks and loading with pressure was investigated. The dynamical process, from cracking to fracturing, was recorded by the acoustic emission technique. Comparing with the conventional method, this method gives more informations, such as pre-cracking, cracking growing, fast fracturing and the pressure values at different phases. During testing time a microcomputer was used for real-time data processing and locating the fracturing position. These data are useful for the mechanical analysis of the reactor components

  7. Analysis of compressive fracture in rock using statistical techniques

    Energy Technology Data Exchange (ETDEWEB)

    Blair, S.C.

    1994-12-01

    Fracture of rock in compression is analyzed using a field-theory model, and the processes of crack coalescence and fracture formation and the effect of grain-scale heterogeneities on macroscopic behavior of rock are studied. The model is based on observations of fracture in laboratory compression tests, and incorporates assumptions developed using fracture mechanics analysis of rock fracture. The model represents grains as discrete sites, and uses superposition of continuum and crack-interaction stresses to create cracks at these sites. The sites are also used to introduce local heterogeneity. Clusters of cracked sites can be analyzed using percolation theory. Stress-strain curves for simulated uniaxial tests were analyzed by studying the location of cracked sites, and partitioning of strain energy for selected intervals. Results show that the model implicitly predicts both development of shear-type fracture surfaces and a strength-vs-size relation that are similar to those observed for real rocks. Results of a parameter-sensitivity analysis indicate that heterogeneity in the local stresses, attributed to the shape and loading of individual grains, has a first-order effect on strength, and that increasing local stress heterogeneity lowers compressive strength following an inverse power law. Peak strength decreased with increasing lattice size and decreasing mean site strength, and was independent of site-strength distribution. A model for rock fracture based on a nearest-neighbor algorithm for stress redistribution is also presented and used to simulate laboratory compression tests, with promising results.

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

    NARCIS (Netherlands)

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

    2016-01-01

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

  9. Minimally Invasive Surgical Approach to Distal Fibula Fractures: A Technique Tip

    Directory of Open Access Journals (Sweden)

    Tyler A. Gonzalez

    2017-01-01

    Full Text Available Wound complications following ankle fracture surgery are a major concern. Through the use of minimally invasive surgical techniques some of these complications can be mitigated. Recent investigations have reported on percutaneous fixation of distal fibula fractures demonstrating similar radiographic and functional outcomes to traditional open approaches. The purpose of this manuscript is to describe in detail the minimally invasive surgical approach for distal fibula fractures.

  10. The Effects of Anesthetic Technique on Postoperative Opioid Consumption in Ankle Fracture Surgery

    DEFF Research Database (Denmark)

    Christensen, Kristian P; Møller, Ann M.; Nielsen, Jesper K.

    2016-01-01

    OBJECTIVES: To investigate the impact of common anesthetic techniques on postoperative opioid consumption in ankle fracture surgery. MATERIALS AND METHODS: We performed a retrospective cohort study on 622 patients with isolated ankle fractures undergoing primary reconstructive surgery. Patients...... anesthesia modalities reduce postoperative opioid consumption in ankle fracture surgery in comparison with GA. A benefit of PNBs is possibly due to an improved pain profile. Our study is retrospective and cannot predict the exact magnitude of this benefit....

  11. Minimally invasive plate osteosynthesis of humeral shaft fractures: a technique to aid fracture reduction and minimize complications.

    Science.gov (United States)

    Shin, Sang-Jin; Sohn, Hoon-Sang; Do, Nam-Hoon

    2012-10-01

    To introduce a modified operative technique for minimally invasive plate osteosynthesis (MIPO) for acute displaced humeral shaft fractures and to evaluate the clinical and radiological outcomes. : Prospective clinical series study. University hospital. Twenty-one patients with acute displaced humeral shaft fractures were treated by MIPO with a modified fracture reduction technique. A narrow 4.5/5.0-mm locking compression plate was applied to the anterior aspect of the humerus. Fracture reduction and manipulation were performed using a plate and drill bits. The operating time, time to union, humeral alignment, and functional outcome of the shoulder and elbow joints were evaluated using the University of California Los Angeles shoulder score and Mayo elbow performance score. No patient experienced a neurological complication. Bony union was obtained in 20/21 patients at a mean 17.5 weeks postoperatively. Eighteen patients had excellent and 3 patients had good results in the University of California Los Angeles score. The average Mayo elbow performance score was 97.5. Two patients were converted to an open reduction during operation due to a failure of MIPO. There was 1 nonunion and 1 malunion in this series. Although the MIPO technique for humeral shaft fractures is technically demanding, satisfactory clinical outcomes in terms of bony union and shoulder and elbow function can be obtained using the modified fracture reduction method. Potential postoperative complications, such as malreduction and nonunion, must be considered. Appropriate surgical indications, a thorough understanding of the neurovascular anatomy and skillful surgical technique, are needed to reduce potential complications.

  12. Femoral fracture repair using a locking plate technique in an adult captive polar bear (Ursus maritimus).

    Science.gov (United States)

    Zimmerman, Dawn M; Dew, Terry; Douglass, Michael; Perez, Edward

    2010-02-01

    To report successful femoral fracture repair in a polar bear. Case report. Female polar bear (Ursus maritimus) 5 years and approximately 250 kg. A closed, complete, comminuted fracture of the distal midshaft femur was successfully reduced and stabilized using a compression plating technique with 2 specialized human femur plates offering axial, rotational, and bending support, and allowing the bone to share loads with the implant. Postoperative radiographs were obtained at 11.5 weeks, 11 months, and 24 months. Bone healing characterized by marked periosteal reaction was evident at 11 months with extensive remodeling evident at 24 months. No complications were noted. Distal mid shaft femoral fracture was reduced, stabilized, and healed in an adult polar bear with a locking plate technique using 2 plates. Previously, femoral fractures in polar bears were considered irreparable. Use of 2 plates applied with a locking plate technique can result in successful fracture repair despite large body weight and inability to restrict postoperative activity.

  13. A Technique of Distal Clavicle Fracture Fixation Using The Tightrope Procedure

    Directory of Open Access Journals (Sweden)

    CJ Soh

    2011-11-01

    Full Text Available We present here a technique of fracture stabilization using the Tightrope procedure in a patient with a widely displaced Neer type IIB distal clavicle fracture. The Tightrope system, typically used for stabilization of acromioclavicular joint dislocation, has not been widely described for distal clavicle fractures. The patient achieved satisfactory results after surgery; we feel that this technique is appealing as it is simple, reproducible and avoids the complications associated with extensive metalwork. This technique may also appeal to the arthroscopic surgeon.

  14. DEVELOPMENT OF RESERVOIR CHARACTERIZATION TECHNIQUES AND PRODUCTION MODELS FOR EXPLOITING NATURALLY FRACTURED RESERVOIRS

    Energy Technology Data Exchange (ETDEWEB)

    Michael L. Wiggins; Raymon L. Brown; Faruk Civan; Richard G. Hughes

    2002-12-31

    For many years, geoscientists and engineers have undertaken research to characterize naturally fractured reservoirs. Geoscientists have focused on understanding the process of fracturing and the subsequent measurement and description of fracture characteristics. Engineers have concentrated on the fluid flow behavior in the fracture-porous media system and the development of models to predict the hydrocarbon production from these complex systems. This research attempts to integrate these two complementary views to develop a quantitative reservoir characterization methodology and flow performance model for naturally fractured reservoirs. The research has focused on estimating naturally fractured reservoir properties from seismic data, predicting fracture characteristics from well logs, and developing a naturally fractured reservoir simulator. It is important to develop techniques that can be applied to estimate the important parameters in predicting the performance of naturally fractured reservoirs. This project proposes a method to relate seismic properties to the elastic compliance and permeability of the reservoir based upon a sugar cube model. In addition, methods are presented to use conventional well logs to estimate localized fracture information for reservoir characterization purposes. The ability to estimate fracture information from conventional well logs is very important in older wells where data are often limited. Finally, a desktop naturally fractured reservoir simulator has been developed for the purpose of predicting the performance of these complex reservoirs. The simulator incorporates vertical and horizontal wellbore models, methods to handle matrix to fracture fluid transfer, and fracture permeability tensors. This research project has developed methods to characterize and study the performance of naturally fractured reservoirs that integrate geoscience and engineering data. This is an important step in developing exploitation strategies for

  15. Development of the transverse tensile and fracture toughness test techniques for spent fuel cladding

    Energy Technology Data Exchange (ETDEWEB)

    Ahn, S. B.; Hong, K. P.; Jung, Y. H.; Seo, H. S.; Oh, W. H.; Yoo, B. O.; Kim, D. S.; Seo, K. S

    2001-12-01

    To define the cause of cladding damage which can take place during the operation of nuclear power plant and the storage through the degradation aspect of mechanical characteristics, the transverse tensile an fracture toughness test were developed in hot cell at IMEF(Irradiated Material Experiment Facility). The following hot cell techniques were developed. 1. The development of a jig and a specimen for transverse tensile test 2. The acquisition of a manufacturing technique for the transverse tensile specimen at hot cell 3. The acquisition of testing procedures and an analysis technque for the transverse tensile 4. The dimensional determination of an optimized fracture toughness specimen 5. The acquisition of manufacturing technique for the fracture toughness test specimen at the hot cell 6. The acquisition of testing procedures and analysis technique for the fracture toughness test (Multiple specimen method, DCPD method, Load ratio method)

  16. Scanning tunneling microscopy - STM: history, principle, construction, and related techniques

    International Nuclear Information System (INIS)

    Ostadal, I.; Sobotik, P.

    1998-01-01

    The method of scanning tunneling microscopy (STM) is discussed. The principle of STM and some other related methods is highlighted, and spectroscopy using STM is dealt with. A brief summary is given of problems to be solved in microscope design, and the influence of these on the resolution obtained is presented. A comparison of STM with other methods used at present in the physics of thin films and surfaces confirms its irreplaceability

  17. Sandia National Laboratories cask drop test programme: a demonstration of fracture mechanics principles for the prevention of brittle fracture

    International Nuclear Information System (INIS)

    McConnell, P.; Sorenson, K.B.

    1995-01-01

    Sandia National Laboratories recently completed a cask drop test programme. The aims of the programme were (1) to demonstrate the applicability of a fracture mechanics-based methodology for ensuring cask integrity, and (2) to assess the viability of using a ferritic materials for cask containment. The programme consisted of four phases: (i) materials characterisation; (ii) non-destructive examination of the cask; (iii) finite element analyses of the drop events; and (iv) a series of drop tests of a ductile iron cask. The first three phases of the programme provided information for fracture mechanics analyses and predictions for the drop test phase. The drop tests were nominally based upon the IAEA 9 m drop height hypothetical accident scenario although one drop test was from 18 m. All tests were performed in the side drop orientation at a temperature of -29 o C. A circumferential, mid-axis flaw was introduced into the cask body for each drop test. Flaw depth ranged from 19 to 76 mm. Steel saddles were welded to the side wall of the cask to enhance the stresses imposed upon the cask in the region of the introduced flaw. The programme demonstrated the applicability of a fracture mechanics methodology for predicting the conditions under which brittle fracture may occur and thereby the utility of fracture mechanics design for ensuring cask structural integrity by ensuring an appropriate margin of safety. Positive assessments of ductile iron for cask containment and the quality of the casting process for producing ductile iron casks were made. The results of this programme have provided data to support IAEA efforts to develop brittle fracture acceptance criteria for cask containment. (author)

  18. Technique Comparison of the Fracture Toughness Tests for Irradiated Fuel Claddings in a Hot Cell

    International Nuclear Information System (INIS)

    Ahn, Sangbok; Kim, Dosik; Jung, Yanghong; Choo, Yongsun; Ryu, Wooseog

    2007-01-01

    The degradation of a fracture toughness in a fuel cladding is a important factor to restrict the operation safety in nuclear power plants. The fracture properties of claddings were traditionally measured through a rubber bung test, a burst test, etc. Those results were the qualitative fracture characteristics, and could not be used as design or operation safety evaluation data. We need to evaluate the quantitative characteristics of claddings under normal operation and in accidents. The application of a fracture mechanics concept in testing a fuel cladding is restricted by the cladding geometry and creating the correct stress-state conditions. The geometry of claddings does not meet the requirement of the ASTM Standards for a specimen configuration and an applied load. The specimen may be produced from previously flattened claddings, but the flattening causes some uncertainties in the results due to changes in the microstructure of the material and a new distribution of the internal stresses. Therefore many efforts have been devoted to developing new test techniques, to quantify the fracture characteristics of claddings. Researchers from JAEA and NFI in Japan, Studsvik Company Ltd in Sweden, IAEA in Australia, and KAERI in Korea have independently developed fracture test techniques. This study is designed to review the independently developed techniques and to compare of their merits. Finally we shall apply the other techniques to upgrade our developing techniques

  19. Structural and geochemical techniques for the hydrogeological characterisation and stochastic modelling of fractured media

    International Nuclear Information System (INIS)

    Vela, A.; Elorza, F.J.; Florez, F.; Paredes, C.; Mazadiego, L.; Llamas, J.F.; Perez, E.; Vives, L.; Carrera, J.; Munoz, A.; De Vicente, G.; Casquet, C.

    1999-01-01

    Safety analysis of radioactive waste storage systems require fractured rock studies. The performance assessment studies of this type of problems include the development of radionuclide flow and transport models to predict the evolution of possible contaminants released from the repository to the biosphere. The methodology developed in the HIDROBAP project and some results obtained with its application in El Berrocal granite batholith are presented. It integrates modern tools belonging to different disciplines. A Discrete Fracture Network model (DFT) was selected to simulate the fractured medium and a 3D finite element flow and transport model that includes the inverse problem techniques has been coupled to the DFT model to simulate the water movement trough the fracture network system. Preliminary results show that this integrated methodology can be very useful for the hydrogeological characterisation of rock fractured media. (author)

  20. Transosseous fixation of pediatric displaced mandibular fractures with polyglactin resorbable suture--a simplified technique.

    Science.gov (United States)

    Chandan, Sanjay; Halli, Rajshekhar; Joshi, Samir; Chhabaria, Gaurav; Setiya, Sneha

    2013-11-01

    Management of pediatric mandibular fractures presents a unique challenge to surgeons in terms of its numerous variations compared to adults. Both conservative and open methods have been advocated with their obvious limitations and complications. However, conservative modalities may not be possible in grossly displaced fractures, which necessitate the open method of fixation. We present a novel and simplified technique of transosseous fixation of displaced pediatric mandibular fractures with polyglactin resorbable suture, which provides adequate stability without any interference with tooth buds and which is easy to master.

  1. A multi-packer technique for investigating resistance to flow through fractured rock and illustrative results

    International Nuclear Information System (INIS)

    Bourke, P.J.; Rae, J.

    1981-01-01

    A multi-packer technique was used to locate twelve discrete fractures in the lower half of a 200 m deep drill hole in Cornish granite. The resistances to water flows into these fractures both singly and together were measured. Geological explanations of the results obtained were sought by examination of core from the hole. Analysis of the results and the further data needed and now being sought to determine resistance to flow over long distances through the pattern of interconnected fractures are discussed. This information is required for the assessment of the safety of burial of radioactive wastes

  2. A Conservative Method for Treating Severely Displaced Pediatric Mandibular Fractures: An Effective Alternative Technique

    OpenAIRE

    Sahand Samieirad; Saeedeh khajehahmadi; Elahe Tohidi; Meysam Pakravan

    2016-01-01

    Pediatric mandibular fractures have been successfully managed in various ways. The use of a lingual splint is an option. This article presents a 4-year old boy who was treated by an alternative conservative method with a combination of an arch bar plus a lingual splint, circum-mandibular wiring and IMF for the reduction, stabilization and fixation of a severely displaced bilateral man‌dibular body fracture. This technique is a reliable, noninvasive procedure; it also limits the discomfort and...

  3. First principle leakage current reduction technique for CMOS devices

    CSIR Research Space (South Africa)

    Tsague, HD

    2015-12-01

    Full Text Available This paper presents a comprehensive study of leakage reduction techniques applicable to CMOS based devices. In the process, mathematical equations that model the power-performance trade-offs in CMOS logic circuits are presented. From those equations...

  4. Double row anchor fixation: a novel technique for a diabetic calanceal insufficiency avulsion fracture.

    Science.gov (United States)

    Greenhagen, Robert M; Highlander, Peter D; Burns, Patrick R

    2012-01-01

    Avulsion fractures of the calcaneal tuberosity represent only 1.3% to 2.7% of calcaneal fractures. These fractures are common pathologically in nature and attributed to decreased bone mineral density. Calcaneal insufficiency avulsion (CIA) fracture in patients with diabetes mellitus is most likely due to Charcot neuroarthropathy (CN) as described by the Brodsky classification (Brodsky 3B). Traditional open reduction and internal fixation is difficult in all calcaneal avulsion fractures because of poor bone quality. The authors report the first known description of the use of fracture fragment excision and double row anchor fixation.A 39-year-old woman with type I diabetes mellitus and a history of CN presented with an avulsion fracture of the calcaneal tuberosity. Excision of the fracture fragment and a gastrocnemius recession and reattachment of the Achilles tendon with double row anchor fixation to the calcaneus were performed. At 1 year, the patient's American Orthopaedic Foot & Ankle Society rearfoot score improved from 27/100 to 88/100. CIA fractures are an infrequently described injury. Because diabetes mellitus is frequently associated with this disease, it most likely represents a CN event. Traditionally, CIA fractures have been operatively treated with open reduction internal fixation. Previous authors have described difficulty with fixation because of poor quality. In the current report, the authors describe a novel operative approach to CIA fractures through the use of double row anchor fixation and excision of the fracture fragments. The authors feel that this previously undescribed treatment is superior to traditional methods and may serve as a new treatment option for all patients who have sustained this unusual pathology regardless of the underlying cause. The current authors provide a novel operative technique that provides inherent advantages to the traditional repair of CIA fractures. We believe CIA fractures represent a CN-type event and care

  5. Physical and measuring principles of nuclear well logging techniques

    International Nuclear Information System (INIS)

    Loetzsch, U.; Winkler, R.

    1981-01-01

    Proceeding from the general task of nuclear geophysics as a special discipline of applied geophyscis, the essential physical problems of nuclear well logging techniques are considered. Particularly, the quantitative relationship between measured values and interesting geologic parameters to be determined are discussed taking into account internal and external perturbation parameters. Resulting from this study, the technological requirements for radiation sources and their shielding, for detectors, electronic circuits in logging tools, signal transmission by cable and recording equipment are derived, and explained on the basis of examples of gamma-gamma and neutron-neutron logging. (author)

  6. Pre-clinical MR elastography: Principles, techniques, and applications

    Science.gov (United States)

    Bayly, P. V.; Garbow, J. R.

    2018-06-01

    Magnetic resonance elastography (MRE) is a method for measuring the mechanical properties of soft tissue in vivo, non-invasively, by imaging propagating shear waves in the tissue. The speed and attenuation of waves depends on the elastic and dissipative properties of the underlying material. Tissue mechanical properties are essential for biomechanical models and simulations, and may serve as markers of disease, injury, development, or recovery. MRE is already established as a clinical technique for detecting and characterizing liver disease. The potential of MRE for diagnosing or characterizing disease in other organs, including brain, breast, and heart is an active research area. Studies involving MRE in the pre-clinical setting, in phantoms and artificial biomaterials, in the mouse, and in other mammals, are critical to the development of MRE as a robust, reliable, and useful modality.

  7. Determination techniques of characteristics of brittle fracture for materials on the CMEA 1-35 problem

    International Nuclear Information System (INIS)

    Makhutov, N.A.; Tananov, A.I.; Koshelev, P.F.; Zatsarinnyj, V.V.

    1981-01-01

    The problems concerning the development and improvement of the investigation techniques and the evaluation of the resistance to brittle fracture of a wide class of materials (the reactor ones, in particular) under different conditions of loading using modern test means are considered in the review. It is reflected in the plan of works on the theme 1-35.3 ''Development of the methods of determination of resistance to brittle fracture of the materials and elements of construct Specialists from CMEA member-countries took an active part in its implementation. The development of the 1-35.3 theme presupposes the creation of scientific bases of calculation methods of the details of machines and elements of constructions according to the criteria of resistance to brittle fracture. The results obtained when using the methods of fracture mechanics are of significant importance in the substantiation of strength and admissible defectiveness of large-size constructions operating under the extremum conditions [ru

  8. Imaging a spinal fracture in a Kohaku Koi (Cyprinus carpio): techniques and case history report

    International Nuclear Information System (INIS)

    Bakal, R.S.; Love, N.E.; Lewbart, G.A.; Berry, C.R.

    1998-01-01

    An ornamental pet fish was diagnosed with a spinal fracture and subluxation involving truncal vertebrae 5 and 6 (T5-T6) using conventional radiography, nuclear scintigraphy, and computed tomography. Attempts to evaluate the dynamic nature of the lesion using conventional fluoroscopy in the unanesthetized, moving patient were? unsuccessful, Adaptation of imaging techniques to accommodate a fish patient was not difficult and diagnostic images were obtained. The use of multiple imaging techniques was useful in the diagnosis and determination of the treatment plan of the spinal fracture in this patient

  9. Development of ductile cast iron for spent fuel cask applications using fracture mechanics principles

    International Nuclear Information System (INIS)

    Ray, K.K.; Tiwari, S.; Hemlata Kumari; Mamta Kumari; Kumar, Hemant; Albert, S.K.; Bhaduri, A.K.

    2016-01-01

    The structure-property relations of ductile cast irons (DCIs) with varying Cu content and ~1 wt.% Ni has been investigated with an emphasis on examining their fracture toughness property towards the development of suitable materials for large volume containers for transport of spent fuel. The detailed microstructural characteristics, hardness, tensile and fracture toughness properties of three DCIs were assessed in as-cast and annealed conditions. Fracture toughness values were determined using both ball indentation (K BI ) and J-integral (KJ Ic ) test. The obtained results assist to infer that: (i) the amount of pearlite and nodule count increases with increased amount of Cu, (ii) the hardness and strength values increases whereas fracture toughness values marginally decreases with increased Cu content, and (iii) the magnitudes of K BI estimated using a proposed analysis are in good agreement with KJ Ic values for the as-cast materials. (author)

  10. Review of fixation techniques for the four-part fractured proximal humerus in hemiarthroplasty

    Directory of Open Access Journals (Sweden)

    Lorenzetti Silvio

    2011-07-01

    Full Text Available Abstract Introduction The clinical outcome of hemiarthroplasty for proximal humeral fractures is not satisfactory. Secondary fragment dislocation may prevent bone integration; the primary stability by a fixation technique is therefore needed to accomplish tuberosity healing. Present technical comparison of surgical fixation techniques reveals the state-of-the-art approach and highlights promising techniques for enhanced stability. Method A classification of available fixation techniques for three- and four part fractures was done. The placement of sutures and cables was described on the basis of anatomical landmarks such as the rotator cuff tendon insertions, the bicipital groove and the surgical neck. Groups with similar properties were categorized. Results Materials used for fragment fixation include heavy braided sutures and/or metallic cables, which are passed through drilling holes in the bone fragments. The classification resulted in four distinct groups: A: both tuberosities and shaft are fixed together by one suture, B: single tuberosities are independently connected to the shaft and among each other, C: metallic cables are used in addition to the sutures and D: the fragments are connected by short stitches, close to the fragment borderlines. Conclusions A plurality of techniques for the reconstruction of a fractured proximal humerus is found. The categorisation into similar strategies provides a broad overview of present techniques and supports a further development of optimized techniques. Prospective studies are necessary to correlate the technique with the clinical outcome.

  11. Techniques developed to evaluate the fracture toughness offast breeder reactor duct

    International Nuclear Information System (INIS)

    Huang, F.H.; Wire, G.L.

    1979-01-01

    Large changes in strength and ductility of metals after irradiation are known to occur. The fracture toughness of irradiated metals, which is related to the combined strength and ductility of a material, may be significantly reduced and the potential for unstable crack extension increased. Therefore, the resistance of cladding and duct materials to fracture after exposure to fast neutron environments is of concern. Existing Type 316 stainless steel irradiated ducts are relatively thin and since this material retains substantial ductility, even after irradiation, the fracture behavior of the duct material cannot be analyzed by linear elastic fracture mechanics techniques. Instead, the multispecimen R-curve method and J-integral analysis were used to develop an experimental approach to evaluate the fracture toughness of thin breeder reactor duct materials irradiated at elevated temperatures. Alloy A-286 was chosen for these experiments because the alloy exhibits elastic/plastic behavior and the fracture toughness data of thicker (12 mm) specimens were available for comparison. Technical problems associated with specimen buckling and remote handling were treated in this work. The results are discussed in terms of thickness criterion for plane strain

  12. A clinical evaluation of alternative fixation techniques for medial malleolus fractures.

    Science.gov (United States)

    Barnes, Hayley; Cannada, Lisa K; Watson, J Tracy

    2014-09-01

    Medial malleolus fractures have traditionally been managed using partially threaded screws and/or Kirschner wire fixation. Using these conventional techniques, a non-union rate of as high as 20% has been reported. In addition too many patients complaining of prominent hardware as a source of pain post-fixation. This study was designed to assess the outcomes of medial malleolar fixation using a headless compression screw in terms of union rate, the need for hardware removal, and pain over the hardware site. Saint Louis University and Mercy Medical Center, Level 1 Trauma Centers, St. Louis, MO. After IRB approval, we used billing records to identify all patients with ankle fractures involving the medial malleolus. Medical records and radiographs were reviewed to identify patients with medial malleolar fractures treated with headless compression screw fixation. Our inclusion criteria included follow-up until full weight bearing and a healed fracture. Follow-up clinical records and radiographs were reviewed to determine union, complication rate and perception of pain over the site of medial malleolus fixation. Sixty-four ankles were fixed via headless compression screws and 44 had adequate follow-up for additional evaluation. Seven patients had isolated medial malleolar fractures, 23 patients had bimalleolar fractures, and 14 patients had trimalleolar fractures. One patient (2%) required hardware removal due to cellulitis. One patient (2%) had a delayed union, which healed without additional intervention. Ten patients (23%) reported mild discomfort to palpation over the medial malleolus. The median follow-up was 35 weeks (range: 12-208 weeks). There were no screw removals for painful hardware and no cases of non-union. Headless compression screws provide effective compression of medial malleolus fractures and result in good clinical outcomes. The headless compression screw is a beneficial alternative to the conventional methods of medial malleolus fixation. Copyright

  13. An in vitro study to determine fracture resistance of tooth roots after different instrumentation techniques

    Directory of Open Access Journals (Sweden)

    Marri Shilpa Reddy

    2016-01-01

    Conclusion: Preparation of canals with a conventional hand instrumentation technique using 0.02 taper K-files showed highest fracture resistance with least amount of dentin removed at all levels followed by Endowave, ProTaper Hand, and Rotary files.

  14. [Clinical experience with various techniques integrated treat the wounded with gunshot fractures of limbs].

    Science.gov (United States)

    Kozlov, V K; Akhmedov, B G; Chililov, A M

    To increase an efficiency of complex treatment of patients with diaphyseal gunshot fractures of long bones by introduction of modern minimally invasive surgical techniques of internal osteosynthesis into clinical practice of civil health care and to improve the outcomes in victims. Prospective comparative clinical trial included 104 victims from the Republic of Yemen with gunshot wounds of limbs of various severity for the period 2009-2011. There were diaphyseal fractures of long bones of limbs associated with soft tissue injuries. Men were predominant (80.7%). Age ranged from 15 to 80 years (mean 38,5 ± 5,7 years). Various surgical techniques of simultaneous and staged treatment were used for gunshot fractures of long bones of limbs. Additional immune therapy was prescribed to prevent infectious complications in the most severe cases. Victims were comprehensively treated according to different staged treatment: conventional surgical treatment with external fixation devices or early primary minimally invasive functionally stable osteosynthesis with LCP/BIOS plates were applied for low-energy fractures; in case of high-energy fractures the first stage included external fixation devices deployment followed by their subsequent replacement during delayed minimally invasive osteosynthesis. The essence of improvement is pursuit to simultaneous minimally invasive surgery by using of current plates for osteosynthesis and preventive immunotherapy of immune dysfunction to eliminate infectious complications. As a result, we obtained 2-fold decrease of surgical invasiveness (r≤0,01) and hospital-stay (r≤0,01). Repeated osteosynthesis was not made. Also 4-fold and 40-fold reduction of infectious and noninfectious complications was observed. This management was accompanied by reduced rehabilitation tine and significantly improved quality of life. Improved technique and algorithm of complex treatment of diaphyseal gunshot fractures of long bones of limbs were described

  15. Isotope techniques in the study of the hydrology of fractured and fissured rocks

    International Nuclear Information System (INIS)

    1989-01-01

    It is generally agreed that the hydrology of fractured rocks refers to the occurrence and movement of groundwater in rocks whose porosity is due to cracks, fissures and fractures in compact rocks. Until recently, crystalline rocks were considered to be impervious (the role of karst reservoirs for groundwater storage is already known). Thus, although fractured rocks cover approximately one-third of the Earth's surface, knowledge of groundwater flow dynamics still needs to be substantively improved. The Proceedings include the papers presented at the Advisory Group Meeting on the Application of Isotope Techniques in the Study of the Hydrology of Fractured and Fissured Rocks, which took place in Vienna from 17 to 21 November 1986. The meeting was attended by 21 scientists from 10 Member States. The Group agreed that the following topics should be given the highest priority: (1) Protection of groundwater resources should be incorporated into all future activities. This implies that recharge areas have to be delineated, not only using nuclear techniques but also other hydrogeological and geochemical methods. Research efforts in this direction should be intensified. (2) The Group was aware that new isotope techniques are being developed in hydrogeology and agreed that their application in fractured and fissured rocks showed promise. It was therefore suggested that information on new isotopes such as 36 Cl and 129 I should be gathered, either in the form of the various techniques currently being used by different laboratories or through the various activities that are being undertaken. Ways of co-ordinating the work being done and exchanging information at the international level should be encouraged. The Proceedings should be of interest to scientists responsible for the evaluation of water resources in crystalline rocks. It is hoped that hydrologists and hydrogeologists working in such terrains who are not familiar with the use of isotope techniques will find ideas and

  16. Internal fixation of severely displaced mandibular condylar neck fracture with the aid of ramus osteotomy. A revised technique

    DEFF Research Database (Denmark)

    Hillerup, S

    1997-01-01

    A technique is described whereby the mandibular condyle can be located, replaced and fixed in case of a severely displaced fracture with exarticulation of the condylar head.......A technique is described whereby the mandibular condyle can be located, replaced and fixed in case of a severely displaced fracture with exarticulation of the condylar head....

  17. A Conservative Method for Treating Severely Displaced Pediatric Mandibular Fractures: An Effective Alternative Technique

    Directory of Open Access Journals (Sweden)

    Sahand Samieirad

    2016-06-01

    Full Text Available Pediatric mandibular fractures have been successfully managed in various ways. The use of a lingual splint is an option. This article presents a 4-year old boy who was treated by an alternative conservative method with a combination of an arch bar plus a lingual splint, circum-mandibular wiring and IMF for the reduction, stabilization and fixation of a severely displaced bilateral man‌dibular body fracture. This technique is a reliable, noninvasive procedure; it also limits the discomfort and morbidity associated with maxillomandibular fixation or open reduction and internal fixation in pediatric patients

  18. Fracture Resistance of Premolars Restored by Various Types and Placement Techniques of Resin Composites

    Directory of Open Access Journals (Sweden)

    Horieh Moosavi

    2012-01-01

    Full Text Available To verify the fracture resistance of premolars with mesioocclusodistal preparations restored by different resin composites and placement techniques. Sixty premolars were randomly divided into two groups based on type of composite resin: Filtek P60 or Nulite F, and then each group was separated into three subgroups: bulk, centripetal, and fiber insert according to the type of placement method (n=10. Single-bond adhesive system was used as composite bonding according to the manufacturer's instructions. Specimens were restored in Groups 1, 2, and 3 with Filtek P60 and in Groups 4, 5, and 6 with Nulite F. After being stored 24 hours at 37∘C, a 4 mm diameter steel sphere in a universal testing machine was applied on tooth buccal and lingual cusps at a cross-head speed of 5 mm/min until fracture occurred. Groups 3 and 6 showed higher fracture resistance than Groups 1, 2, 4, and 5. Among the placement techniques, the fiber insert method had a significant effect, but the type of composite was ineffective. The insertion technique in contrast to the type of material had a significant influence on the fracture resistance of premolar teeth.

  19. Evaluation of hot hardness, creep, fatigue and fracture properties of zirconia ceramics by an indentation technique

    International Nuclear Information System (INIS)

    Kutty, T.R.G.; Ganguly, C.; Upadhyaya, D.D.

    1996-01-01

    Zirconia ceramics have wide range engineering applications at room and elevated temperatures. For understanding the mechanical behaviour, the indentation technique was adapted for quick evaluation of hot hardness, creep, fatigue and fracture properties. A Vicker's diamond indentor with 10 N load was employed for hot hardness and creep measurement up to 1300 deg. The fatigue data were evaluated at room temperature by repeated indentation with a constant load (10-2500N) at the same location for a dwell time of 5s until it resulted in the formation of a lateral chip on the sample surface. Thus, the number of cycles for chip formation at a specific indentation load was obtained. The fracture toughness was evaluated at room temperature with a load of 300N using a Vicker's diamond indentor. The results of hot hardness, creep, fatigue, and fracture data ol 3Y-TZP and Mg-PSZ are discussed along with their microstructural features. (authors)

  20. Diagnosis of vertebral fractures in children: is a simplified algorithm-based qualitative technique reliable?

    International Nuclear Information System (INIS)

    Adiotomre, E.; Summers, L.; Digby, M.; Allison, A.; Walters, S.J.; Broadley, P.; Lang, I.; Offiah, A.C.

    2016-01-01

    Identification of osteoporotic vertebral fractures allows treatment opportunity reducing future risk. There is no agreed standardised method for diagnosing paediatric vertebral fractures. To evaluate the precision of a modified adult algorithm-based qualitative (ABQ) technique, applicable to children with primary or secondary osteoporosis. Three radiologists independently assessed lateral spine radiographs of 50 children with suspected reduction in bone mineral density using a modified ABQ scoring system and following simplification to include only clinically relevant parameters, a simplified ABQ score. A final consensus of all observers using simplified ABQ was performed as a reference standard for fracture characterisation. Kappa was calculated for interobserver agreement of the components of both scoring systems and intraobserver agreement of simplified ABQ based on a second read of 29 randomly selected images. Interobserver Kappa for modified ABQ scoring for fracture detection, severity and shape ranged from 0.34 to 0.49 Kappa for abnormal endplate and position assessment was 0.27 to 0.38. Inter- and intraobserver Kappa for simplified ABQ scoring for fracture detection and grade ranged from 0.37 to 0.46 and 0.45 to 0.56, respectively. Inter- and intraobserver Kappa for affected endplate ranged from 0.31 to 0.41 and 0.45 to 0.51, respectively. Subjectively, observers' felt simplified ABQ was easier and less time-consuming. Observer reliability of modified and simplified ABQ was similar, with slight to moderate agreement for fracture detection and grade/severity. Due to subjective preference for simplified ABQ, we suggest its use as a semi-objective measure of diagnosing paediatric vertebral fractures. (orig.)

  1. Diagnosis of vertebral fractures in children: is a simplified algorithm-based qualitative technique reliable?

    Energy Technology Data Exchange (ETDEWEB)

    Adiotomre, E. [Sheffield Teaching Hospitals NHS Foundation Trust UK, Radiology Department, Sheffield (United Kingdom); Sheffield Children' s NHS Foundation Trust, Radiology Department, Sheffield (United Kingdom); Summers, L.; Digby, M. [University of Sheffield UK, Sheffield Medical School, Sheffield (United Kingdom); Allison, A.; Walters, S.J. [University of Sheffield UK, School of Health and Related Research, Sheffield (United Kingdom); Broadley, P.; Lang, I. [Sheffield Children' s NHS Foundation Trust, Radiology Department, Sheffield (United Kingdom); Offiah, A.C. [Sheffield Children' s NHS Foundation Trust, Radiology Department, Sheffield (United Kingdom); University of Sheffield UK, Academic Unit of Child Health, Sheffield (United Kingdom)

    2016-05-15

    Identification of osteoporotic vertebral fractures allows treatment opportunity reducing future risk. There is no agreed standardised method for diagnosing paediatric vertebral fractures. To evaluate the precision of a modified adult algorithm-based qualitative (ABQ) technique, applicable to children with primary or secondary osteoporosis. Three radiologists independently assessed lateral spine radiographs of 50 children with suspected reduction in bone mineral density using a modified ABQ scoring system and following simplification to include only clinically relevant parameters, a simplified ABQ score. A final consensus of all observers using simplified ABQ was performed as a reference standard for fracture characterisation. Kappa was calculated for interobserver agreement of the components of both scoring systems and intraobserver agreement of simplified ABQ based on a second read of 29 randomly selected images. Interobserver Kappa for modified ABQ scoring for fracture detection, severity and shape ranged from 0.34 to 0.49 Kappa for abnormal endplate and position assessment was 0.27 to 0.38. Inter- and intraobserver Kappa for simplified ABQ scoring for fracture detection and grade ranged from 0.37 to 0.46 and 0.45 to 0.56, respectively. Inter- and intraobserver Kappa for affected endplate ranged from 0.31 to 0.41 and 0.45 to 0.51, respectively. Subjectively, observers' felt simplified ABQ was easier and less time-consuming. Observer reliability of modified and simplified ABQ was similar, with slight to moderate agreement for fracture detection and grade/severity. Due to subjective preference for simplified ABQ, we suggest its use as a semi-objective measure of diagnosing paediatric vertebral fractures. (orig.)

  2. Applied predictive analytics principles and techniques for the professional data analyst

    CERN Document Server

    Abbott, Dean

    2014-01-01

    Learn the art and science of predictive analytics - techniques that get results Predictive analytics is what translates big data into meaningful, usable business information. Written by a leading expert in the field, this guide examines the science of the underlying algorithms as well as the principles and best practices that govern the art of predictive analytics. It clearly explains the theory behind predictive analytics, teaches the methods, principles, and techniques for conducting predictive analytics projects, and offers tips and tricks that are essential for successful predictive mode

  3. A casting and imaging technique for determining void geometry and relative permeability behavior of a single fracture specimen

    Energy Technology Data Exchange (ETDEWEB)

    Cox, B.L.; Pruess, K.; Persoff, P.

    1990-01-01

    A casting technique has been developed for making translucent replicas of the void space of natural rock fractures. Attenuation of light shined through the cast combined with digital image analysis provides a pointwise definition of fracture apertures. The technique has been applied to a fracture specimen from Dixie Valley, Nevada, and the measured void space geometry has been used to develop theoretical predictions of two-phase relative permeability. A strong anisotropy in relative permeabilities has been found, which is caused by highly anisotropic spatial correlations among fracture apertures. 16 refs., 6 figs.

  4. Minimally invasive treatment of trochanteric fractures with intramedullary nails. Technique and results.

    Science.gov (United States)

    Todor, Adrian; Pojar, Adina; Lucaciu, Dan

    2013-01-01

    The aim of the study was to evaluate the results of minimally invasive treatment of trochanteric fractures with the use of intramedullary nails. From September 2010 to September 2012 we treated 21 patients with pertrochanteric fractures by a minimally invasive technique using the Gamma 3 (Stryker, Howmedica) nail. There were 13 females and 8 men with a mean age of 74.1 years, ranging from 58 to 88 years. Fractures were classified as being stable (AO type 31-A1) in 5 cases and unstable (AO type 31-A2 and A3) in the rest of 16 cases. Patients were reviewed at 6 weeks and 3 months postoperatively. Mean surgery time was 46.8 minutes and mean hospital stay was 14.9 days. No patients required blood transfusions. During the hospital stay all the patients were mobilized with weight bearing as tolerated. All patients were available for review at 6 weeks, and 2 were lost to the 3 months follow up. 16 patients regained the previous level of activity. This minimally invasive technique using a gamma nail device for pertrochanteric fractures gives reliable good results with excellent preservation of hip function.

  5. Evaluation of geophysical techniques for identifying fractures in program wells in Deaf Smith County, Texas: Revision 1, Topical report

    International Nuclear Information System (INIS)

    Gillespie, R.P.; Siminitz, P.C.

    1987-08-01

    Quantitative information about the presence and orientation of fractures is essential for the understanding of the geomechanical and geohydrological behavior of rocks. This report evaluates various borehole geophysical techniques for characterizing fractures in three Civilian Radioactive Waste Management (CRWM) Program test wells in the Palo Duro Basin in Deaf Smith County, Texas. Emphasis has been placed on the Schlumberger Fracture Identification Log (FIL) which detects vertical fractures and provides data for calculation of orientation. Depths of FIL anomalies were compared to available core. It was found that the application of FIL results to characterize fracture frequency or orientation is inappropriate at this time. The uncertainties associated with the FIL information render the information unreliable. No geophysical logging tool appears to unequivocally determine the location and orientation of fractures in a borehole. Geologic mapping of the exploratory shafts will ultimately provide the best data on fracture frequency and orientation at the proposed repository site. 22 refs., 6 figs., 3 tabs

  6. Quantitative Phase Imaging Techniques for the Study of Cell Pathophysiology: From Principles to Applications

    Directory of Open Access Journals (Sweden)

    Hyunjoo Park

    2013-03-01

    Full Text Available A cellular-level study of the pathophysiology is crucial for understanding the mechanisms behind human diseases. Recent advances in quantitative phase imaging (QPI techniques show promises for the cellular-level understanding of the pathophysiology of diseases. To provide important insight on how the QPI techniques potentially improve the study of cell pathophysiology, here we present the principles of QPI and highlight some of the recent applications of QPI ranging from cell homeostasis to infectious diseases and cancer.

  7. Multiple-output all-optical header processing technique based on two-pulse correlation principle

    NARCIS (Netherlands)

    Calabretta, N.; Liu, Y.; Waardt, de H.; Hill, M.T.; Khoe, G.D.; Dorren, H.J.S.

    2001-01-01

    A serial all-optical header processing technique based on a two-pulse correlation principle in a semiconductor laser amplifier in a loop mirror (SLALOM) configuration that can have a large number of output ports is presented. The operation is demonstrated experimentally at a 10Gbit/s Manchester

  8. [Treatment of Schatzker IV tibial plateau fractures with arthroscopy combined with MIPPO technique].

    Science.gov (United States)

    Li, Jian-Wen; Ye, Feng; Bi, Da-Wei; Zheng, Xiao-Dong; Chen, Jian-Liang

    2018-02-25

    To discusses the clinical effects of arthroscopy combined with minimally invasive percutaneous plate osteosynthesis(MIPPO) technology in treating Schatzker IV tibial plateau fractures. From January 2012 to January 2016, 19 patients with Schatzker type IV tibial plateau fractures were treated with arthroscopy combined with minimally invasive technique including 12 males and 7 females with an average age of 46.5 years old ranging from 19 to 78 years old. Patients were suffering knee pain, swelling, flexion and extension limited, and other symptoms preoperative. Patients were followed up and assessed by Rasmussen knee function score. No infection, traumatic arthritis, and knee joint valgus occurred after operation. Nineteen cases were followed up for 12 to 24 months with an average of 18.6 months. Fracture healing time was 3 to 5 months with an average of 3.8 months. The knee pain and limited mobility improved significantly. The range of autonomic movement of joints was from 90 to 136 degrees. According to Rasmussen functional score criteria, the total score was 27.00±2.49, the result was excellent in 16 cases, good in 2 cases, fair in 1 case. Arthroscopic treatment for Schatzker type IV tibial plateau fractures combined with MIPPO can simultaneously treat internal structural injuries such as meniscus and other knee joints, with less trauma, fewer complications, and faster joint function recovery, but we must strictly grasp surgical indications and avoid expanding injuries. Copyright© 2018 by the China Journal of Orthopaedics and Traumatology Press.

  9. Posterior malleolar fracture: technique and clinical ex-perience of the posterolateral approach

    Directory of Open Access Journals (Sweden)

    HUANG Ruo-kun

    2012-04-01

    Full Text Available 【Abstract】Objective: To introduce the postero-lateral surgical approach to the posterior malleolar fracture and report its clinical outcomes in 32 cases. Methods: This study consisted of 32 cases, 22 males and 10 females with the mean age of 48 years (range, 21-63 years, suffering from posterior malleolar fracture. All cases were treated with the posterolateral surgical approach to the ankle. The average follow-up period was 28 months (range, 24-35 months. The clinical outcomes of these cases were evaluated on the basis of the Olerud-Molander Ankle (OMA score and plain radiographs. Results: All cases showed radiological evidence of bony union at follow-up. The average OMA score was 82 points; 21 cases had excellent scores (90-100 points, 9 good (61-90 points, and 2 fair (31-60 points. The excellent-to-good rate was 93.8%. Although most cases did not show any wound dehiscence or necrosis, one patient had a su-perficial infection which healed after using antibiotic dress-ing and one had sural cutaneous nerve injury that under-went spontaneous remission without any treatment after three months. In addition, one presented with mild symp-toms of peroneal tendonitis that disappeared after plate removal. Conclusion: The posterolateral approach offers an effective technique for fracture reduction and fixation of large posterior malleolar fragments. Key words: Ankle injuries; Dislocations; Fracture fixation, internal

  10. Evaluation of deformation and fracture characteristics of nuclear reactor materials using ball indentation test technique

    International Nuclear Information System (INIS)

    Byun, T. S.; Hong, J. H.; Lee, B. S.; Park, D. G.; Kim, J. H.; Oh, Y. J.; Yoon, J. H.; Chi, S. H.; Kuk, I. H.; Kwon, D. I.; Lee, J. H.

    1998-05-01

    The present report describes the automated ball indentation test techniques and the results of their applications. The ball indentation test technique is an innovative method for evaluating the key mechanical properties from the indentation load-depth data. In the 1st chapter, the existing technique for evaluating basic deformation (tensile) properties is described in detail, and also the application result of the technique is presented. The through-thickness variations of mechanical properties in SA 508 C1.3 reactor pressure vessel steels were measured using an automated ball indentation (ABI) technique. In the 2nd chapter, a method under development, which is similar to that in the 1st chapter, is new method is based on the theoretical solutions rather than experimental relationships. The result of the application showed that the stress-strain curves of various metals were successfully determined with the method. In the 3rd chapter, a new theoretical model was proposed to estimate the fracture toughness of ferritic steels in the transition temperature region. The key concept of the model is that the indention energy to a critical load is related to the fracture energy of the material. The theory was applied to the reactor pressure vessel (RPV) base and weld metals. (author). 24 refs., 3 tabs., 6 figs

  11. Fracture detection in crystalline rock using ultrasonic reflection techniques: Volume 1

    International Nuclear Information System (INIS)

    Palmer, S.P.

    1982-11-01

    This research was initiated to investigate using ultrasonic seismic reflection techniques to detect fracture discontinuities in a granitic rock. Initial compressional (P) and shear (SH) wave experiments were performed on a 0.9 x 0.9 x 0.3 meter granite slab in an attempt to detect seismic energy reflected from the opposite face of the slab. It was found that processing techniques such as deconvolution and array synthesis could improve the standout of the reflection event. During the summers of 1979 and 1980 SH reflection experiments were performed at a granite quarry near Knowles, California. The purpose of this study was to use SH reflection methods to detect an in situ fracture located one to three meters behind the quarry face. These SH data were later analyzed using methods similar to those applied in the laboratory. Interpretation of the later-arriving events observed in the SH field data as reflections from a steeply-dipping fracture was inconclusive. 41 refs., 43 figs., 7 tabs

  12. [An improved reduction technique for depression fractures of lateral tibial plateau].

    Science.gov (United States)

    Wang, Hongchuan; Lou, Hua; Liu, Kai; Jiang, Junwei

    2013-01-01

    To investigate the improved reduction technique for depression fractures of the lateral tibial plateau and its effectiveness. Between January 2008 and December 2010; 48 patients (48 knees) with depression fractures of the lateral tibial plateau (Schatzker II or III fractures) were treated. There were 32 males and 16 females with an average age of 45.8 years (range, 16-79 years). All fractures were fresh closed fractures, which were caused by traffic accident in 27 cases, by falling from height in 5 cases, by crushing in 8 cases, and by sustained falls in 8 cases. According to Schatzker classification, 29 cases were classified as type II and 19 cases as type III. The lateral cortex was cut off to expose the depression and compacted cancellous bone was elevated to reset the articular surface. After reduction, autologous iliac bone graft and locking plate internal fixation were used. Healing of incision by first intention was achieved in all patients, and no complication occurred. All patients were followed up 1.7 years on average (range, 1-3 years). At last follow-up, the knee extension was (-0.5 +/- 0.3) degrees, and the knee flexion was (136.9 +/- 8.8) degrees. X-ray films showed that the fracture healing time was 52 weeks and no breakage of internal fixation occurred. According to Rasmussen clinical score, the results were excellent in 35 cases, good in 10 cases, and fair in 3 cases. According to Rasmussen radiographical score, the results were excellent in 41 cases, good in 7 cases; there were 41 excellent scores and 7 good scores of articular reduction; all gained good recovery of coronal and sagittal alignment and condylar width. The articular surface collapse was (1.0 +/- 0.7) mm at immediate postoperatively and (1.2 +/- 0.7) mm at last follow-up, showing no significant difference (t = -1.42, P = 0.20), but significant differences were found when compared with that at preoperation [(12.2 +/- 8.0) mm, P fracture reduction and can avoid loss of reduction. The

  13. Building Quakes: Detection of Weld Fractures in Buildings using High-Frequency Seismic Techniques

    Science.gov (United States)

    Heckman, V.; Kohler, M. D.; Heaton, T. H.

    2009-12-01

    Catastrophic fracture of welded beam-column connections in buildings was observed in the Northridge and Kobe earthquakes. Despite the structural importance of such connections, it can be difficult to locate damage in structural members underneath superficial building features. We have developed a novel technique to locate fracturing welds in buildings in real time using high-frequency information from seismograms. Numerical and experimental methods were used to investigate an approach for detecting the brittle fracture of welds of beam-column connections in instrumented steel moment-frame buildings through the use of time-reversed Green’s functions and wave propagation reciprocity. The approach makes use of a prerecorded catalogue of Green’s functions for an instrumented building to detect high-frequency failure events in the building during a later earthquake by screening continuous data for the presence of one or more of the events. This was explored experimentally by comparing structural responses of a small-scale laboratory structure under a variety of loading conditions. Experimentation was conducted on a polyvinyl chloride frame model structure with data recorded at a sample rate of 2000 Hz using piezoelectric accelerometers and a 24-bit digitizer. Green’s functions were obtained by applying impulsive force loads at various locations along the structure with a rubber-tipped force transducer hammer. We performed a blind test using cross-correlation techniques to determine if it was possible to use the catalogue of Green’s functions to pinpoint the absolute times and locations of subsequent, induced failure events in the structure. A finite-element method was used to simulate the response of the model structure to various source mechanisms in order to determine the types of elastic waves that were produced as well as to obtain a general understanding of the structural response to localized loading and fracture.

  14. Minimally invasive surgical technique: Percutaneous external fixation combined with titanium elastic nails for selective treatment of tibial fractures.

    Science.gov (United States)

    Tu, Kai-Kai; Zhou, Xian-Ting; Tao, Zhou-Shan; Chen, Wei-Kai; Huang, Zheng-Liang; Sun, Tao; Zhou, Qiang; Yang, Lei

    2015-12-01

    Several techniques have been described to treat tibial fractures, which respectively remains defects. This article presents a novel intra- and extramedullary fixation technique: percutaneous external fixator combined with titanium elastic nails (EF-TENs system). The purpose of this study is to introduce this new minimally invasive surgical technique and selective treatment of tibial fractures, particularly in segmental fractures, diaphysis fractures accompanied with distal or proximal bone subfissure, or fractures with poor soft-tissue problems. Following ethical approval, thirty-two patients with tibial fractures were treated by the EF-TENs system between January 2010 and December 2012. The follow-up studies included clinical and radiographic examinations. All relevant outcomes were recorded during follow-up. All thirty-two patients were achieved follow-ups. According to the AO classification, 3 Type A, 9 Type B and 20 Type C fractures were included respectively. According to the Anderson-Gustilo classification, there were 5 Type Grade II, 3 Type Grade IIIA and 2 Type Grade IIIB. Among 32 patients, 8 of them were segmental fractures. 12 fractures accompanied with bone subfissure. Results showed no nonunion case, with an average time of 23.7 weeks (range, 14-32 weeks). Among them, there were 3/32 delayed union patients and 0/32 malunion case. 4/32 patients developed a pin track infection and no patient suffered deep infection. The external fixator was removed with a mean time of 16.7 weeks (range, 10-26 weeks). Moreover, only 1/32 patient suffered with the restricted ROM of ankle, none with the restricted ROM of knee. This preliminary study indicated that the EF-TENs system, as a novel intra- and extramedullary fixation technique, had substantial effects on selective treatment of tibial fractures. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. [Measurement of screw length through drilling technique in osteosynthesis of the proximal humerus fractures].

    Science.gov (United States)

    Avcı, Cem Coşkun; Gülabi, Deniz; Sağlam, Necdet; Kurtulmuş, Tuhan; Saka, Gürsel

    2013-01-01

    This study aims to investigate the efficacy of screw length measurement through drilling technique on the reduction of intraarticular screw penetration and fluoroscopy time in osteosynthesis of proximal humerus fractures. Between January 2008 and June 2012, 98 patients (34 males, 64 females; mean age 64.4 years; range 35 to 81 years) who underwent osteosynthesis using locking anatomical proximal humerus plates (PHILOS) in our clinic with the diagnosis of Neer type 2, 3 or 4 were included. Two different surgical techniques were used to measure proximal screw length in the plate and patients were divided into two groups based on the technique used. In group 1, screw length was determined by a 3 mm blunt tipped Kirschner wire without fluoroscopic control. In group 2, bilateral fluoroscopic images for each screw at least were obtained. Intraarticular screw penetration was detected in five patients (10.6%) in group 1, and in 19 patients (37.3%) in group 2. The mean fluoroscopic imaging time was 10.6 seconds in group 1 and 24.8 seconds in group 2, indicating a statistically significant difference. Screw length measurement through the drilling technique significantly reduces the intraarticular screw penetration and fluoroscopy time in osteosynthesis of proximal humerus fractures using PHILOS plates.

  16. Construction techniques and working principles of external cathode Geiger-Mueller counters

    International Nuclear Information System (INIS)

    Sevegnani, Francisco Xavier

    1996-01-01

    In this paper, the construction technique and working principles of the external cathode Geiger-Mueller counter are described in detail. During the analysis of the behavior of these counters a new phenomena was observed, related to an increase int he background rate with the applied voltage. The experiments have also shown that the pulse amplitude of those counters decreases exponentially with the counting rate. The counters built with the techniques described in this paper has shown plateaus of about 1400 V with slope of 0,8%/100 V. (author)

  17. A Second-Order Maximum Principle Preserving Lagrange Finite Element Technique for Nonlinear Scalar Conservation Equations

    KAUST Repository

    Guermond, Jean-Luc; Nazarov, Murtazo; Popov, Bojan; Yang, Yong

    2014-01-01

    © 2014 Society for Industrial and Applied Mathematics. This paper proposes an explicit, (at least) second-order, maximum principle satisfying, Lagrange finite element method for solving nonlinear scalar conservation equations. The technique is based on a new viscous bilinear form introduced in Guermond and Nazarov [Comput. Methods Appl. Mech. Engrg., 272 (2014), pp. 198-213], a high-order entropy viscosity method, and the Boris-Book-Zalesak flux correction technique. The algorithm works for arbitrary meshes in any space dimension and for all Lipschitz fluxes. The formal second-order accuracy of the method and its convergence properties are tested on a series of linear and nonlinear benchmark problems.

  18. Clavicular fractures: Classification, diagnosis, therapy

    International Nuclear Information System (INIS)

    Schunk, K.; Strunk, H.; Schild, H.; Lohr, S.

    1988-01-01

    Clavicular fracture is one of the most frequent skeletal lesions. In most cases the median third of the clavicula is affected (this is due to the peculiar biomechanical structure). Accompanying lesions and complications of clavicular fractures are rare. A total of 13 X-ray diagnostic techniques are described of clavicular fractures. X-ray film should, as a matter of principle, always be taken in two planes. Definitely the major part of clavicular fractures are treated conservatively (rucsac dressing), whereas surgery is reserved for few and strictly defined indications. (orig.) [de

  19. Clavicular fractures: Classification, diagnosis, therapy

    Energy Technology Data Exchange (ETDEWEB)

    Schunk, K.; Strunk, H.; Schild, H.; Lohr, S.

    1988-09-01

    Clavicular fracture is one of the most frequent skeletal lesions. In most cases the median third of the clavicula is affected (this is due to the peculiar biomechanical structure). Accompanying lesions and complications of clavicular fractures are rare. A total of 13 X-ray diagnostic techniques are described of clavicular fractures. X-ray film should, as a matter of principle, always be taken in two planes. Definitely the major part of clavicular fractures are treated conservatively (rucsac dressing), whereas surgery is reserved for few and strictly defined indications.

  20. Imaging Fracture Networks Using Angled Crosshole Seismic Logging and Change Detection Techniques

    Science.gov (United States)

    Knox, H. A.; Grubelich, M. C.; Preston, L. A.; Knox, J. M.; King, D. K.

    2015-12-01

    We present results from a SubTER funded series of cross borehole geophysical imaging efforts designed to characterize fracture zones generated with an alternative stimulation method, which is being developed for Enhanced Geothermal Systems (EGS). One important characteristic of this stimulation method is that each detonation will produce multiple fractures without damaging the wellbore. To date, we have collected six full data sets with ~30k source-receiver pairs each for the purposes of high-resolution cross borehole seismic tomographic imaging. The first set of data serves as the baseline measurement (i.e. un-stimulated), three sets evaluate material changes after fracture emplacement and/or enhancement, and two sets are used for evaluation of pick error and seismic velocity changes attributable to changing environmental factors (i.e. saturation due to rain/snowfall in the shallow subsurface). Each of the six datasets has been evaluated for data quality and first arrivals have been picked on nearly 200k waveforms in the target area. Each set of data is then inverted using a Vidale-Hole finite-difference 3-D eikonal solver in two ways: 1) allowing for iterative ray tracing and 2) with fixed ray paths determined from the test performed before the fracture stimulation of interest. Utilizing these two methods allows us to compare and contrast the results from two commonly used change detection techniques. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  1. Accuracy of percutaneous pedicle screws for thoracic and lumbar spine fractures compared with open technique.

    Science.gov (United States)

    Paredes, Igor; Panero, Irene; Cepeda, Santiago; Castaño-Leon, Ana M; Jimenez-Roldan, Luis; Perez-Nuñez, Ángel; Alén, Jose A; Lagares, Alfonso

    2018-06-14

    This study aimed to compare the accuracy of screw placement between open pedicle screw fixation and percutaneous pedicle screw fixation (MIS) for the treatment of thoracolumbar spine fractures (TSF). Forty-nine patients with acute TSF who were treated with transpedicular screw fixation from January 2013 to December 2016 were retrospectively reviewed. The patients were divided into Open and MIS groups. Laminectomy was performed in either group if needed. The accuracy of the screw placement, the evolution of the Cobb sagital angle postoperatively and at 12-month follow up and the neurological status were recorded. AO type of fracture and TLICS score were also recorded. Mean age was 42 years old. Mean TLICS score was 6,29 and 5,96 for open and MIS groups respectively. Twenty five MIS and 24 open surgeries were performed, and 350 (175 in each group) screws were inserted (7,14 per patient). Twenty-four and 13 screws were considered ̈out ̈ in the open and MIS groups respectively (Odds ratio 1,98. 0,97-4,03 p=0,056). The Cobb sagittal angle went from 13,3o to 4,5o and from 14,9o to 8,2o in the Open and MIS groups respectively (both popen and MIS groups respectively. No neurological worsening was observed. For the treatment of acute thoracolumbar fractures, the MIS technique seems to achieve similar results to the open technique in relation to neurological improvement and deformity correction, while placing the screws more accurately.

  2. [Application of rafting K-wire technique for tibial plateau fractures].

    Science.gov (United States)

    Zhang, Xing-zhou; Yu, Wei-zhong; Li, Yun-feng; Liu, Yan-hui

    2015-12-01

    To summarize application of rafting K-wires technique for tibial plateau fractures. From January 2013 to January 2015,45 patients with tibial plateau fractures were treated by locking plate with rafting K-wires, including 33 males and 12 females with an average of 44.2 years old ranging from 22 to 56 years old. According to Schatzker classification, 6 cases were type II, 8 were type Ill, 4 were type IV, 4 were type V, and 5 were type VI. Allogeneic bone graft were performed for bone defects. All patients were fixed with two to five K-wires. Part of weight loading were encouraged at 3 months after operation,and full weight-loading were done at 5 months after operation. Postoperative complications were observed,and Rasmussen clinical and radiological assessment were used to evaluate clinical results. All Patients were followed up from 10 to 23 months with average of 14 months. According to Rasmussen clinical and radiological assessment, clinical scores 23.58 ± 6.33, radiological scores were 14.00 ± 6.33; and excellent and good rates were 82.2% and 77.8% respectively. Four patients occurred severe osteoporosis and collapse of articular surface; 5 patients occurred traumatic arthritis. Rafting K-wires technique with anatomized armor plate could effective fix and support platform collapse and joint bone fragments, increase support surface area and reduce postoperative reduction loss rate.

  3. Ionization techniques in capillary electrophoresis-mass spectrometry: principles, design, and application.

    Science.gov (United States)

    Hommerson, Paul; Khan, Amjad M; de Jong, Gerhardus J; Somsen, Govert W

    2011-01-01

    A major step forward in the development and application of capillary electrophoresis (CE) was its coupling to ESI-MS, first reported in 1987. More than two decades later, ESI has remained the principal ionization technique in CE-MS, but a number of other ionization techniques have also been implemented. In this review the state-of-the-art in the employment of soft ionization techniques for CE-MS is presented. First the fundamentals and general challenges of hyphenating conventional CE and microchip electrophoresis with MS are outlined. After elaborating on the characteristics and role of ESI, emphasis is put on alternative ionization techniques including sonic spray ionization (SSI), thermospray ionization (TSI), atmospheric pressure chemical ionization (APCI), atmospheric pressure photoionization (APPI), matrix-assisted laser desorption ionization (MALDI) and continuous-flow fast atom bombardment (CF-FAB). The principle of each ionization technique is outlined and the experimental set-ups of the CE-MS couplings are described. The strengths and limitations of each ionization technique with respect to CE-MS are discussed and the applicability of the various systems is illustrated by a number of typical examples. Copyright © 2011 Wiley Periodicals, Inc.

  4. Model-driven engineering of information systems principles, techniques, and practice

    CERN Document Server

    Cretu, Liviu Gabriel

    2015-01-01

    Model-driven engineering (MDE) is the automatic production of software from simplified models of structure and functionality. It mainly involves the automation of the routine and technologically complex programming tasks, thus allowing developers to focus on the true value-adding functionality that the system needs to deliver. This book serves an overview of some of the core topics in MDE. The volume is broken into two sections offering a selection of papers that helps the reader not only understand the MDE principles and techniques, but also learn from practical examples. Also covered are the

  5. Generalized multivalued equilibrium-like problems: auxiliary principle technique and predictor-corrector methods

    Directory of Open Access Journals (Sweden)

    Vahid Dadashi

    2016-02-01

    Full Text Available Abstract This paper is dedicated to the introduction a new class of equilibrium problems named generalized multivalued equilibrium-like problems which includes the classes of hemiequilibrium problems, equilibrium-like problems, equilibrium problems, hemivariational inequalities, and variational inequalities as special cases. By utilizing the auxiliary principle technique, some new predictor-corrector iterative algorithms for solving them are suggested and analyzed. The convergence analysis of the proposed iterative methods requires either partially relaxed monotonicity or jointly pseudomonotonicity of the bifunctions involved in generalized multivalued equilibrium-like problem. Results obtained in this paper include several new and known results as special cases.

  6. Hydrajet fracturing: an effective method for placing many fractures in openhole horizontal wells

    Energy Technology Data Exchange (ETDEWEB)

    Surjaatmadja, J. B.; Grundmann, S. R.; McDaniel, B.; Deeg, W. F. J.; Brumley, J. L.; Swor, L. C.

    1998-12-31

    A new method for openhole horizontal well fracturing that combines hydrajetting and fracturing techniques, which was developed on the basis of Bernoulli`s theorem, is described. This theorem has been effectively proven in many applications such as jet pumps, additive injection systems and jet aircraft engines. By using this method, operators can position a jetting tool, without the use of sealing elements, at the exact point where fracture is required. The method also permits the use of multiple fractures in the same well, which can be spaced evenly or unevenly as prescribed by the fracturing program. Damage can be avoided by placing hundreds of small fractures in a long horizontal section, or operators can use acid and/or propped sand techniques to place a combination of two fracture types in the well. The paper describes the basic principles of horizontal hydrajet fracturing, and elements of a laboratory model which was developed to demonstrate the effectiveness of the method.

  7. [Clinical application of blocking screws and rooting technique in the treatment of distal tibial fracture with interlocking intramedullary nail].

    Science.gov (United States)

    Zhu, Hai-Bing; Wu, Li-Guo; Fang, Zhi-Song; Luo, Cong-Feng; Wang, Qing-Feng; Ma, Yi-Ping; Gao, Hong; Fu, Guo-Hai; Hu, Cheng-Ting

    2012-07-01

    To introduce the clinical method of blocking screws and rooting technique in the treatment of distal tibial fracture with interlocking intramedullary nails. From June 2006 to March 2011, 26 patients with distal tibial fracture were treated with interlocking intramedullary nails using blocking screws and rooting technique, included 18 males and 8 females with an average age of 46.2 years old ranging from 24 to 64 years. According to AO classification: 10 cases of type A1, 4 cases of type A2, 8 cases of type B1, 4 cases of type B2. The average distance of the fractures end to the ankle joint was 85 mm ranging from 55 to 125 mm, the mean time between injured and operation was 4.5 days. The patients were evaluated with pain, range of motion, walking. All cases were followed-up for 6 to 22 months (averaged 15 months). According to Iowa ankle joint grading system,the score was improved from preoperative (66.8 +/- 8.2) to postoperative (94.6 +/- 4.8). All fractures had united, and got satisfactory reduction and stable fixation with no complications had happen such as breakage of screw. Fixation with interlocking intramedullary nail using blocking screws and rooting technique in treating distal tibial fracture, is a safe and effective technique for the improvement of stability.

  8. A new internal fixation technique for fractures of the proximal humerus--the Bilboquet device: a report on 26 cases.

    Science.gov (United States)

    Doursounian, L; Grimberg, J; Cazeau, C; Jos, E; Touzard, R C

    2000-01-01

    We describe a novel internal fixation device and report on 26 patients (mean age, 70 years) whose proximal humeral fractures were managed with this technique. The 2-part titanium implant consists of a circular staple impacted into the humeral head cancellous bone and a spigoted diaphyseal stem that inserts into the staple "cup." Of the 26 cases reviewed, 16 had 3-part fractures and 10 had 4-part fractures. Mean follow-up was 25.9 months. In the 16 3-part fractures, the mean active forward elevation was 114 degrees and the results were as follows: excellent, 7; good, 5; fair, 3; poor, 1. In the 10 4-part fracture patients, the mean active forward elevation was 101 degrees and the results were as follows: excellent, 2; good, 4; fair, 3; poor, 1. There were 5 cases of avascular necrosis and 1 case of tuberosity nonunion. Only 2 cases needed conversion to hemiarthroplasty. The new technique should simplify the surgery of these fractures and reduce the need for arthroplasty.

  9. State-of-the-art MRI techniques in neuroradiology: principles, pitfalls, and clinical applications

    Energy Technology Data Exchange (ETDEWEB)

    Viallon, Magalie [Universite de Lyon, CREATIS, UMR CNRS 5220 - INSERM U1044, INSA de Lyon, Lyon (France); Universite de Lyon-Saint-Etienne, Department of Radiology, Centre Hospitalier Universitaire de Saint-Etienne, Saint Etienne (France); Cuvinciuc, Victor; Barnaure-Nachbar, Isabelle; Lovblad, Karl-Olof; Haller, Sven [University Hospital of Geneva, Department of Neuroradiology, Geneva (Switzerland); Delattre, Benedicte; Toso-Patel, Seema; Becker, Minerva [University Hospital of Geneva, Department of Radiology, Geneva (Switzerland); Merlini, Laura [University Hospital of Geneva, Department of Pediatric Radiology, Geneva (Switzerland)

    2015-05-01

    This article reviews the most relevant state-of-the-art magnetic resonance (MR) techniques, which are clinically available to investigate brain diseases. MR acquisition techniques addressed include notably diffusion imaging (diffusion-weighted imaging (DWI), diffusion tensor imaging (DTI), and diffusion kurtosis imaging (DKI)) as well as perfusion imaging (dynamic susceptibility contrast (DSC), arterial spin labeling (ASL), and dynamic contrast enhanced (DCE)). The underlying models used to process these images are described, as well as the theoretic underpinnings of quantitative diffusion and perfusion MR imaging-based methods. The technical requirements and how they may help to understand, classify, or follow-up neurological pathologies are briefly summarized. Techniques, principles, advantages but also intrinsic limitations, typical artifacts, and alternative solutions developed to overcome them are discussed. In this article, we also review routinely available three-dimensional (3D) techniques in neuro MRI, including state-of-the-art and emerging angiography sequences, and briefly introduce more recently proposed 3D quantitative neuro-anatomy sequences, and new technology, such as multi-slice and multi-transmit imaging. (orig.)

  10. State-of-the-art MRI techniques in neuroradiology: principles, pitfalls, and clinical applications

    International Nuclear Information System (INIS)

    Viallon, Magalie; Cuvinciuc, Victor; Barnaure-Nachbar, Isabelle; Lovblad, Karl-Olof; Haller, Sven; Delattre, Benedicte; Toso-Patel, Seema; Becker, Minerva; Merlini, Laura

    2015-01-01

    This article reviews the most relevant state-of-the-art magnetic resonance (MR) techniques, which are clinically available to investigate brain diseases. MR acquisition techniques addressed include notably diffusion imaging (diffusion-weighted imaging (DWI), diffusion tensor imaging (DTI), and diffusion kurtosis imaging (DKI)) as well as perfusion imaging (dynamic susceptibility contrast (DSC), arterial spin labeling (ASL), and dynamic contrast enhanced (DCE)). The underlying models used to process these images are described, as well as the theoretic underpinnings of quantitative diffusion and perfusion MR imaging-based methods. The technical requirements and how they may help to understand, classify, or follow-up neurological pathologies are briefly summarized. Techniques, principles, advantages but also intrinsic limitations, typical artifacts, and alternative solutions developed to overcome them are discussed. In this article, we also review routinely available three-dimensional (3D) techniques in neuro MRI, including state-of-the-art and emerging angiography sequences, and briefly introduce more recently proposed 3D quantitative neuro-anatomy sequences, and new technology, such as multi-slice and multi-transmit imaging. (orig.)

  11. Bioremediation techniques-classification based on site of application: principles, advantages, limitations and prospects.

    Science.gov (United States)

    Azubuike, Christopher Chibueze; Chikere, Chioma Blaise; Okpokwasili, Gideon Chijioke

    2016-11-01

    Environmental pollution has been on the rise in the past few decades owing to increased human activities on energy reservoirs, unsafe agricultural practices and rapid industrialization. Amongst the pollutants that are of environmental and public health concerns due to their toxicities are: heavy metals, nuclear wastes, pesticides, green house gases, and hydrocarbons. Remediation of polluted sites using microbial process (bioremediation) has proven effective and reliable due to its eco-friendly features. Bioremediation can either be carried out ex situ or in situ, depending on several factors, which include but not limited to cost, site characteristics, type and concentration of pollutants. Generally, ex situ techniques apparently are more expensive compared to in situ techniques as a result of additional cost attributable to excavation. However, cost of on-site installation of equipment, and inability to effectively visualize and control the subsurface of polluted sites are of major concerns when carrying out in situ bioremediation. Therefore, choosing appropriate bioremediation technique, which will effectively reduce pollutant concentrations to an innocuous state, is crucial for a successful bioremediation project. Furthermore, the two major approaches to enhance bioremediation are biostimulation and bioaugmentation provided that environmental factors, which determine the success of bioremediation, are maintained at optimal range. This review provides more insight into the two major bioremediation techniques, their principles, advantages, limitations and prospects.

  12. Avulsion Fracture of the Calcaneus Treated With a Soft Anchor Bridge and Lag Screw Technique: A Report of Two Cases.

    Science.gov (United States)

    Yoshida, Kazushige; Kasama, Kentaro; Akahane, Tsutomu

    2016-01-01

    The displaced extra-articular avulsion fracture of the calcaneus has been classified as a Böhler type 1c calcaneal fracture, and most cases will require surgical repair. In the present report, we describe 2 patients in whom we performed the soft anchor bridge technique using single loaded suture anchors with lag screws for the repair of Böhler type 1c avulsion fractures of the calcaneus. In one of these patients, clinically relevant osteoporosis complicated the injury. In both cases, bone union was achieved, and by 1.5 months after surgery satisfactory recovery was observed. To our knowledge, the soft anchor bridge technique was first used for the treatment of rotator cuff tears, and the greatest merit of this technique is the ability to generate vertical compression force to the pulled out rotator cuff through the use of knotting sutures. In recent years, the soft anchor bridge technique using 4 suture anchors has also been used for fractures of the greater tuberosity of the humerus, an injury that poses operative difficulties similar to those encountered with an avulsion fracture of the calcaneus owing to the traction force of the rotator cuff and relative weakness of adjacent bone. The outcomes of our patients suggest that the soft anchor bridge technique combined with adjunct lag screws is useful in the fixation of avulsion fractures of the calcaneus. In addition, the result in the elderly patient indicates the possibility of using this technique for patients with osteoporosis. Copyright © 2016 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

  13. Prognosis of Open Type 3-B Tibia Fractures By Ilizarov Technique: A Prospective Study

    OpenAIRE

    Janak Rathod, Taral Shah

    2012-01-01

    Background: Open fractures of the tibial shaft are both common and may be fraught with complications. Open fractures of the tibia, with associated vascular injuries, have historically had a very poor outcome. Malunion, delayed union, nonunion, and infection are all seen regularly after open tibia fractures. Objectives: Objective of the study is to explore advantage of primary or early ilizarov surgery in Open type 3- B fracture tibia. Methodology: A follow up study of 10 cases of open type 3-...

  14. Life management of Zr 2.5% Nb pressure tube through estimation of fracture properties by cyclic ball indentation technique

    International Nuclear Information System (INIS)

    Chatterjee, S.; Madhusoodanan, K.; Rama Rao, A.

    2015-01-01

    In Pressurised Heavy Water Reactors (PHWRs) fuel bundles are located inside horizontal pressure tubes. Pressure tubes made up of Zr 2.5 wt% Nb undergo degradation during in-service environmental conditions. Measurement of mechanical properties of degraded pressure tubes is important for assessing its fitness for further service in the reactor. The only way to accomplish this important objective is to develop a system based on insitu measurement technique. Considering the importance of such measurement, an In-situ Property Measurement System (IProMS) based on cyclic ball indentation technique has been designed and developed indigenously. The remotely operable system is capable of carrying out indentation trial on the inside surface of the pressure tube and to estimate important mechanical properties like yield strength, ultimate tensile strength, hardness etc. It is known that fracture toughness is one of the important life limiting parameters of the pressure tube. Hence, five spool pieces of Zr 2.5 wt% Nb pressure tube of different mechanical properties have been used for estimation of fracture toughness by ball indentation method. Curved Compact Tension (CCT) specimens were also prepared from the five spool pieces for measurement of fracture toughness from conventional tests. The conventional fracture toughness values were used as reference data. A methodology has been developed to estimate the fracture properties of Zr 2.5 wt% Nb pressure tube material from the analysis of the ball indentation test data. This paper highlights the comparison between tensile properties measured from conventional tests and IProMS trials and relates the fracture toughness parameters measured from conventional tests with the IProMS estimated fracture properties like Indentation Energy to Fracture. (author)

  15. Cardiopulmonary resuscitation (CPR)-related posterior rib fractures in neonates and infants following recommended changes in CPR techniques.

    Science.gov (United States)

    Franke, I; Pingen, A; Schiffmann, H; Vogel, M; Vlajnic, D; Ganschow, R; Born, M

    2014-07-01

    Posterior rib fractures are highly indicative of non-accidental trauma (NAT) in infants. Since 2000, the "two-thumbs" technique for cardiopulmonary resuscitation (CPR) of newborns and infants has been recommended by the American Heart Association (AHA). This technique is similar to the grip on an infant's thorax while shaking. Is it possible that posterior rib fractures in newborns and infants could be caused by the "two-thumbs" technique? Using computerized databases from three German children's hospitals, we identified all infants less than 12 months old who underwent professional CPR within a 10-year period. We included all infants with anterior-posterior chest radiographs taken after CPR. Exclusion criteria were sternotomy, osteopenia, various other bone diseases and NAT. The radiographs were independently reviewed by the Chief of Pediatric Radiology (MB) and a Senior Pediatrician, Head of the local Child Protection Team (IF). Eighty infants with 546 chest radiographs were identified, and 50 of those infants underwent CPR immediately after birth. Data concerning the length of CPR was available for 41 infants. The mean length of CPR was 11min (range: 1-180min, median: 3min). On average, there were seven radiographs per infant. A total of 39 infants had a follow-up radiograph after at least 10 days. No rib fracture was visible on any chest X-ray. The results of this study suggest rib fracture after the use of the "two-thumbs" CPR technique is uncommon. Thus, there should be careful consideration of abuse when these fractures are identified, regardless of whether CPR was performed and what technique used. The discovery of rib fractures in an infant who has undergone CPR without underlying bone disease or major trauma warrants a full child protection investigation. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. [Sinus tarsi approach combined with medial distraction technique for treatment of intra-articular calcaneus fractures].

    Science.gov (United States)

    Zhou, Haichao; Ren, Haoyang; Li, Bing; Yu, Tao; Yang, Yunfeng

    2016-07-08

    ?To discuss the effectiveness of limited open reduction via sinus tarsi approach using medial distraction technique in the treatment of intra-articular calcaneus fractures by comparing with open reduction and internal fixation via extensile L-shaped incision. ?A retrospective analysis was made on the clinical data of 21 patients with intra-articular calcaneus fractures treated by sinus tarsi approach combined with medial distraction technique between April 2013 and November 2014 (minimally invasive group), and 32 patients treated by extensile L-shaped incision approach between June 2012 and September 2014 (extensile incision group). No significant difference was found in gender, age, injury pattern, fracture classification, time from injury to operation, preoperative Böhler angle, Gissane angle, calcaneal varus angle, the ankle and hind-foot score of American Orthopaedic Foot and Ankle Society (AOFAS), and visual analogue scale (VAS) score between 2 groups (P>0.05), which was comparable. The operation time, wound complications, and bone healing time were recorded. The postoperative function was also evaluated by AOFAS score and VAS score. The pre-and post-operative Böhler angle, Gissane angle, and calcaneal varus angle were measured on the X-ray films, and the corrective angle was calculated. ?Sixteen patients were followed up 6-18 months (mean, 11.5 months) in the minimally invasive group, and 23 patients for 6-24 months (mean, 13.5 months) in the extensile incision group. Difference was not significant in operation time between 2 groups (t=0.929, P=0.796). No complication occurred in the minimally invasive group; partial skin flap necrosis occurred in 3 cases of the extensile incision group, was cured after dressing change. There was no loosening of implants or reduction loss in 2 groups at last follow-up. Subtalar joint stiffness occurred in 1 case of the minimally invasive group and 4 cases of the extensile incision group, and 1 patient had discomfort for the

  17. Towards automating the discovery of certain innovative design principles through a clustering-based optimization technique

    Science.gov (United States)

    Bandaru, Sunith; Deb, Kalyanmoy

    2011-09-01

    In this article, a methodology is proposed for automatically extracting innovative design principles which make a system or process (subject to conflicting objectives) optimal using its Pareto-optimal dataset. Such 'higher knowledge' would not only help designers to execute the system better, but also enable them to predict how changes in one variable would affect other variables if the system has to retain its optimal behaviour. This in turn would help solve other similar systems with different parameter settings easily without the need to perform a fresh optimization task. The proposed methodology uses a clustering-based optimization technique and is capable of discovering hidden functional relationships between the variables, objective and constraint functions and any other function that the designer wishes to include as a 'basis function'. A number of engineering design problems are considered for which the mathematical structure of these explicit relationships exists and has been revealed by a previous study. A comparison with the multivariate adaptive regression splines (MARS) approach reveals the practicality of the proposed approach due to its ability to find meaningful design principles. The success of this procedure for automated innovization is highly encouraging and indicates its suitability for further development in tackling more complex design scenarios.

  18. Construction techniques and operation principles of Geiger-Mueller counters using external cathode (Mazetype)

    International Nuclear Information System (INIS)

    Sevegnani, F.X.

    1988-01-01

    The construction techniques for external cathode (Maze) and internal cathode Geiger-Muller counters are described, showing the operation principles and the used material nature. More than 200 counter types were evaluated analysing their characteristics. The influence of several types of guard-rings was studied, for optimizing counter operation conditions. Plateaus of the order of 700 V with slope of 0,3%/100 V for the net counting rate, and 1400 V with a slope of 0,8/100 V for total counts using total pressure of 10 cmHg, were obtained. A counter for β detection, using blown glass window in one of the edges of the cylinder was constructed. Counters of long life using materials such as, mica, adhesive glues, etc., were obtained. The results shown that the best counter operation occurs when it is empty in a vacuum of 10 -5 mmHg. (M.C.K.) [pt

  19. Hydraulic Parameter Generation Technique Using a Discrete Fracture Network with Bedrock Heterogeneity in Korea

    Directory of Open Access Journals (Sweden)

    Jae-Yeol Cheong

    2017-12-01

    Full Text Available In instances of damage to engineered barriers containing nuclear waste material, surrounding bedrock is a natural barrier that retards radionuclide movement by way of adsorption and delay due to groundwater flow through highly tortuous fractured rock pathways. At the Gyeongju nuclear waste disposal site, groundwater mainly flows through granitic and sedimentary rock fractures. Therefore, to understand the nuclide migration path, it is necessary to understand discrete fracture networks based on heterogeneous fracture orientations, densities, and size characteristics. In this study, detailed heterogeneous fracture distribution, including the density and orientation of the fractures, was considered for a region that has undergone long periods of change from various geological activities at and around the Gyeongju site. A site-scale discrete fracture network (DFN model was constructed taking into account: (i regional fracture heterogeneity constrained by a multiple linear regression analysis of fracture intensity on faults and electrical resistivity; and (ii the connectivity of conductive fractures having fracture hydraulic parameters, using transient flow simulation. Geometric and hydraulic heterogeneity of the DFN was upscaled into equivalent porous media for flow and transport simulation for a large-scale model.

  20. Wiring Techniques for the Fixation of Trochanteric Fragments during Bipolar Hemiarthroplasty for Femoral Intertrochanteric Fracture: Clinical Study and Technical Note.

    Science.gov (United States)

    Lee, Joong-Myung; Cho, Yongsuk; Kim, Junhyun; Kim, Dong-Won

    2017-03-01

    Femoral intertrochanteric fractures are common in the elderly. Appropriate surgical fixation of trochanteric fracture fragments can restore normal anatomical structure and ambulation, and can aid in the recovery of biomechanical function of the hip. We evaluated clinical outcomes of bipolar hemiarthroplasty using a wiring technique for trochanteric fracture fragment fixation. From September 2006 to February 2015, a total of 260 cases underwent simultaneous bipolar hemiarthroplasty and wire fixation. A total of 65 patients (69 hips) with an average age of 78 years and more than one year of follow-up was included in the study. Using pre-, postoperative and follow-up radiograms, we evaluated wire fixation failure and also assessed changes in walking ability. Loosening or osteolysis around the stem was not observed; however, we did observe bone growth around the stem (54 cases), cortical hypertrophy (6 cases), a wide range of sclerotic lines but no stem subsidence (1 case), wire breakage (9 cases), and fracture fragment migration with no significant functional deficiency (2 cases). Our study showed that additional wiring for trochanteric fracture fragment fixation following bipolar hemiarthroplasty can help restore normal anatomy. The added stability results in faster rehabilitation, and good clinical and radiographic outcomes. We recommend this procedure in this type of fracture.

  1. Evaluation of fracture toughness for metal/ceramics composite materials by means of miniaturized specimen technique

    International Nuclear Information System (INIS)

    Saito, Masahiro; Takahashi, Hideaki; Jeong, Hee-Don; Kawasaki, Akira; Watanabe, Ryuzo

    1991-01-01

    In order to evaluate fracture strength for Y 2 O 3 -ZrO 2 , 3 mol% Y 2 O 3 -ZrO 2 (PSZ)/SUS 304 composite materials, Macor as a machinable ceramics and comercially available ceramics (SiC, Si 3 N 4 , PSZ, Al 2 O 3 ), fracture toughness tests were carried out by use of RCT or bending specimens. On the other hand, the fracture strength of these materials was evaluated and inspected the correlation between fracture toughness and fracture stress of small punch (SP) or modified small punch (MSP) test data to predict the fracture toughness value by using miniaturized specimens. Characteristic of the MSP testing method is the ability to evaluate elastic modulus (Young's modulus), fracture strength, yield strength, fracture strain, and fracture energy, etc., with high accuracy and good reproducibility for brittle materials. For a series of metal/ ceramics composites which from ductile to brittle, this paper clarified clear the applicable range for SP and MSP testing methods, which suggested that the simultaneous use of SP and MSP test methods can evaluate the fracture strength of metal/ ceramics composites. (author)

  2. Sterile insect technique. Principles and practice in area-wide integrated pest management

    International Nuclear Information System (INIS)

    Dyck, V.A.; Hendrichs, J.; Robinson, A.S.

    2005-01-01

    For several major insect pests, the environment-friendly sterile insect technique (SIT) is being applied as a component of area-wide integrated pest management (AW-IPM) programmes. This technology, using radiation to sterilize insects, was first developed in the USA, and is currently applied on six continents. For four decades it has been a major subject for research and development in the Joint FAO/IAEA Programme on Nuclear Techniques in Food and Agriculture, involving both research and the transfer of this technology to Member States so that they can benefit from improved plant, animal and human health, cleaner environments, increased production of plants and animals in agricultural systems, and accelerated economic development. The socio-economic impacts of AW-IPM programmes that integrate the SIT have confirmed the usefulness of this technology. Numerous publications related to the integration of the SIT in pest management programmes, arising from research, coordinated research projects, field projects, symposia, meetings, and training activities have already provided much information to researchers, pest-control practitioners, programme managers, plant protection and animal health officers, and policy makers. However, by bringing together and presenting in a generic fashion the principles, practice, and global application of the SIT, this book will be a major reference source for all current and future users of the technology. The book will also serve as a textbook for academic courses on integrated pest management. Fifty subject experts from 19 countries contributed to the chapters, which were all peer reviewed before final editing

  3. Tomosynthesis: A new radiologic technique for rapid diagnosis of scaphoid fractures.

    Science.gov (United States)

    Compton, N; Murphy, L; Lyons, F; Jones, J; MacMahon, P; Cashman, J

    2016-12-21

    Scaphoid fractures constitute 71% of all carpal bone fractures. 1 Early diagnosis and treatment has significant bearing on fracture union rates and better clinical outcomes. While displaced fractures can be readily seen on plain radiograph, undisplaced fractures can require advanced imaging modalities to confirm that diagnosis. Advanced imaging such as Magnetic Resonance Imaging (MRI), Computerised tomography (CT) and bone scintigraphy are routinely used for the diagnosis of scaphoid fractures but require significant radiation exposure, increased cost and can be difficult to access. 2 Tomosynthesis is an emerging imaging modality which uses conventional x-ray systems to produce cross-sectional images. There has yet to be extensive research carried out investigating the diagnostic value of tomosynthesis in scaphoid fractures. The aim of this study is to optimise patient positioning for the diagnosis of scaphoid fractures in a cadaveric model and compare the diagnostic yield of tomography to conventional CT. Using four cadaveric specimens, three limb positions were examined in unfractured and fractured scaphoids to determine the optimal limb positions required for visualisation of the scaphoid. As a result of this study, the optimal position for visualisation of the scaphoid and diagnosis of scaphoid fractures has been determined. The results demonstrate that tomosynthesis is as effective as CT scanning in identifying scaphoid fractures in both sensitivity and specificity. By comparison to CT, tomosynthesis is cheaper, has lower radiation exposure, requires fewer hospital resources and can be performed quickly. Tomosynthesis is a valid diagnostic tool for the diagnosis of scaphoid fractures. Copyright © 2016 Royal College of Surgeons of Edinburgh (Scottish charity number SC005317) and Royal College of Surgeons in Ireland. Published by Elsevier Ltd. All rights reserved.

  4. Comparative characteristics of osteosynthesis techniques in patients with comminuted diaphyseal femoral fractures

    Directory of Open Access Journals (Sweden)

    A. P. Barabash

    2013-01-01

    Full Text Available The comparative analysis of the results of the surgical treatment of 130 patients with closed comminuted unilateral diaphyseal femoral fractures, including assessment of anatomic functional outcomes of treatment according to the technique of the standardized investigations in traumatology and orthopedy and determination of quality of life according to SF-36 method is carried out. Osteosynthesis with the help of external fixation devices was performed in 36 patients, intramedullary interlocking osteosynthesis - in 57 patients, compression plating - in 37 patients. Level of anatomic functional rehabilitation of the patients in the early postoperative period made up 69-79 %, 6 months later increased up to 74-92%, and after the expiration of 12 months the level of rehabilitation reached 85-99%. During the treatment quality of life concerning physical component was within the limits from 36,8 up to 55,5 %, and concerning mental component - 54,3-60,8 %. After the expiration of a year increase in the parameters of physical and mental components up to 55,7 - 59,8 % and 57,2-65,8 % is detected respectively. In the group where the transosseous osteosynthesis technique was applied we got 93,7-95 % of positive outcomes, with the average disability period of 212,3±18,1 days. In 47,2 % of cases the following complications are observed: knee contracture - 7; inflammation of the soft tissues located near the transosseous fixators - 5 (13,9%; shortening of the limb less than 5% of its length - 3; false joint formation - 1; fracture union with formation of varus deformity in the femoral bone - 1. When using intramedullary interlocking osteosynthesis we had positive results in 96,5 % of cases, with the average period of disability 176±17,8 days. In 10,5 % cases the following complications are observed: suture sinus - 1(1,75 %; femoral osteomyelitis - 1; break of the design - 1; false joint formation - 1; knee contracture - 1; shortening of the limb less than 5

  5. Value of Earth Observations: Key principles and techniques of socioeconomic benefits analysis (Invited)

    Science.gov (United States)

    Friedl, L.; Macauley, M.; Bernknopf, R.

    2013-12-01

    Internationally, multiple organizations are placing greater emphasis on the societal benefits that governments, businesses, and NGOs can derive from applications of Earth-observing satellite observations, research, and models. A growing set of qualitative, anecdotal examples on the uses of Earth observations across a range of sectors can be complemented by the quantitative substantiation of the socioeconomic benefits. In turn, the expanding breadth of environmental data available and the awareness of their beneficial applications to inform decisions can support new products and services by companies, agencies, and civil society. There are, however, significant efforts needed to bridge the Earth sciences and social and economic sciences fields to build capacity, develop case studies, and refine analytic techniques in quantifying socioeconomic benefits from the use of Earth observations. Some government programs, such as the NASA Earth Science Division's Applied Sciences Program have initiated activities in recent years to quantify the socioeconomic benefits from applications of Earth observations research, and to develop multidisciplinary models for organizations' decision-making activities. A community of practice has conducted workshops, developed impact analysis reports, published a book, developed a primer, and pursued other activities to advance analytic methodologies and build capacity. This paper will present an overview of measuring socioeconomic impacts of Earth observations and how the measures can be translated into a value of Earth observation information. It will address key terms, techniques, principles and applications of socioeconomic impact analyses. It will also discuss activities to pursue a research agenda on analytic techniques, develop a body of knowledge, and promote broader skills and capabilities.

  6. Plate Fixation With Autogenous Calcaneal Dowel Grafting Proximal Fourth and Fifth Metatarsal Fractures: Technique and Case Series.

    Science.gov (United States)

    Seidenstricker, Chad L; Blahous, Edward G; Bouché, Richard T; Saxena, Amol

    Metaphyseal and proximal diaphyseal fractures of the lateral column metatarsals can have problems with healing. In particular, those involving the fifth metatarsal have been associated with a high nonunion rate with nonoperative treatment. Although intramedullary screw fixation results in a high union rate, delayed healing and complications can occur. We describe an innovative technique to treat both acute and chronic injuries involving the metatarsal base from the metaphysis to the proximal diaphyseal bone of the fourth and fifth metatarsals. The surgical technique involves evacuation of sclerotic bone at the fracture site, packing the fracture site with compact cancellous bone, and plate fixation. In our preliminary results, 4 patients displayed 100% radiographic union at a mean of 4.75 (range 4 to 6) weeks with no incidence of refracture, at a mean follow-up point of 3.5 (range 1 to 5) years. The early results with our small series suggest that this technique is a useful treatment choice for metaphyseal and proximal diaphyseal fractures of the fourth and fifth metatarsals. Copyright © 2017 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

  7. Application of Rapid Prototyping Technique and Intraoperative Navigation System for the Repair and Reconstruction of Orbital Wall Fractures

    Science.gov (United States)

    Cha, Jong Hyun; Lee, Yong Hae; Ruy, Wan Chul; Roe, Young; Moon, Myung Ho

    2016-01-01

    Background Restoring the orbital cavity in large blow out fractures is a challenge for surgeons due to the anatomical complexity. This study evaluated the clinical outcomes and orbital volume after orbital wall fracture repair using a rapid prototyping (RP) technique and intraoperative navigation system. Methods This prospective study was conducted on the medical records and radiology records of 12 patients who had undergone a unilateral blow out fracture reconstruction using a RP technique and an intraoperative navigation system from November 2014 to March 2015. The surgical results were assessed by an ophthalmic examination and a comparison of the preoperative and postoperative orbital volume ratio (OVR) values. Results All patients had a successful treatment outcome without complications. Volumetric analysis revealed a significant decrease in the mean OVR from 1.0952±0.0662 (ranging from 0.9917 to 1.2509) preoperatively to 0.9942±0.0427 (ranging from 0.9394 to 1.0680) postoperatively. Conclusion The application of a RP technique for the repair of orbital wall fractures is a useful tool that may help improve the clinical outcomes by understanding the individual anatomy, determining the operability, and restoring the orbital cavity volume through optimal implant positioning along with an intraoperative navigation system. PMID:28913272

  8. Application of FIB technique to introduction of a notch into a carbon fiber for direct measurement of fracture toughness

    International Nuclear Information System (INIS)

    Ogihara, S; Imafuku, Y; Yamamoto, R; Kogo, Y

    2009-01-01

    For the direct measurement of the fracture toughness of the carbon fiber, a new technique was proposed and examined its applicability. At first, machining condition of the notch was examined. The notch was introduced using focused ion beam (FIB). The ion beam can be electronically scanned to introduce a sharp notch on the carbon fiber. Notches with various notch width and length were introduced by changing beam and scanning conditions. Tensile tests on notched carbon fibers were carried out following the test method for carbon fiber monofilaments. Fractured specimens were successfully corrected without secondary damage using protection films. SEM observations revealed that a crack propagated from a notch-tip, and notch size was able to be determined successfully. Effect of notch root radius was also examined to investigate the validity of the fracture toughness obtained by this method.

  9. A comparison of digital luminescence radiography and conventional film/screen techniques in the diagnosis of fractures

    International Nuclear Information System (INIS)

    Fink, U.; Schwerdtfeger, J.; Fink, B.K.; Schaetzl, M.; Reiser, M.

    1996-01-01

    The accuracy of digital luminescence radiography was compared with that of conventional film/screen techniques, using animal preparations and clinical examinations. Fine fissures were made in 8 animal bones and these were examined radiologically. The digital examinations were carried out with and without edge enhancement. 208 patients were examined in a similar way. Film quality and assessment of the fractures were evaluated quantitatively. In no instance did either of the digital methods provide inferior quality when compared with conventional films. ROC analysis for evaluation of fractures in patients, using an experienced radiologist, showed no significant difference between the various methods (ROC areas: Conventional 0.947, digital 0.958, digital with edge enhancement 0.943). With a less experienced observer there were significant advantages for both digital methods (ROC areas: 0.851, 0.886, 0.908). Our investigation has proved that fractures which are difficult to see can be reliably demonstrated by digital luminescence radiography. (orig.) [de

  10. A new in situ technique for studying deformation and fracture in thin film ductile/brittle laminates

    International Nuclear Information System (INIS)

    Hackney, S.A.; Milligan, W.W.

    1991-01-01

    A new technique for studying deformation and fracture of thin film ductile/brittle laminates is described. The laminates are prepared by sputtering a brittle coating on top of an electropolished TEM thin foil. The composites are then strained in situ in the TEM. In this preliminary investigation, the composites consisted of a ductile aluminum substrate and a brittle silicon coating. Cracks in the brittle film grew discontinuously in bursts several micrometers in length. The crack opening displacement initiated plastic deformation in the ductile film, thus dissipating energy and allowing crack arrest. The interface was well bonded, and delamination was not observed. Due to the good interfacial bond and the crack opening behind the crack tip, it was possible to study very large plastic deformations and ductile fracture in the aluminum in situ, without buckling of the foil. The possibility of micromechanical modeling of the fracture behavior is briefly discussed. (orig.)

  11. Fracture resistance of metal-free composite crowns-effects of fiber reinforcement, thermal cycling, and cementation technique.

    Science.gov (United States)

    Lehmann, Franziska; Eickemeyer, Grit; Rammelsberg, Peter

    2004-09-01

    The improved mechanical properties of contemporary composites have resulted in their extensive use for the restoration of posterior teeth. However, the influence of fiber reinforcement, cementation technique, and physical stress on the fracture resistance of metal-free crowns is unknown. This in vitro study evaluated the effect of fiber reinforcement, physical stress, and cementation methods on the fracture resistance of posterior metal-free Sinfony crowns. Ninety-six extracted human third molars received a standardized tooth preparation: 0.5-mm chamfer preparation and occlusal reduction of 1.3 to 1.5 mm. Sinfony (nonreinforced crowns, n=48) and Sinfony-Vectris (reinforced crowns, n=48) crowns restoring original tooth contour were prepared. Twenty-four specimens of each crown type were cemented, using either glass ionomer cement (GIC) or resin cement. Thirty-two crowns (one third) were stored in humidity for 48 hours. Another third was exposed to 10,000 thermal cycles (TC) between 5 degrees C and 55 degrees C. The remaining third was treated with thermal cycling and mechanical loading (TCML), consisting of 1.2 million axial loads of 50 N. The artificial crowns were then vertically loaded with a steel sphere until failure occurred. Significant differences in fracture resistance (N) between experimental groups were assessed by nonparametric Mann-Whitney U-test (alpha=.05). Fifty percent of the Sinfony and Sinfony-Vectris crowns cemented with glass ionomer cement loosened after thermal cycling. Thermal cycling resulted in a significant reduction in the mean fracture resistance for Sinfony crowns cemented with GIC, from 2037 N to 1282 N (P=.004). Additional fatigue produced no further effects. Fiber reinforcement significantly increased fracture resistance, from 1555 N to 2326 N (P=.001). The minimal fracture resistance was above 600 N for all combinations of material, cement and loading. Fracture resistance of metal-free Sinfony crowns was significantly increased by

  12. Two peg spade plate for distal radius fractures A novel technique

    Directory of Open Access Journals (Sweden)

    Sharad M Hardikar

    2015-01-01

    Conclusions: The two peg volar spade plate provides a stable subchondral support in comminuted intraarticular fractures and maintains reduction in osteoporotic fractures of the distal radius. Early mobilization with this implant helps in restoring wrist motion and to prevent development of wrist stiffness.

  13. ProTaper rotary instrument fracture during root canal preparation: a comparison between rotary and hybrid techniques.

    Science.gov (United States)

    Farid, Huma; Khan, Farhan Raza; Rahman, Munawar

    2013-03-01

    This study aimed to compare the frequency of ProTaper rotary instrument fracture with rotary (conventional) and hybrid (rotary and hand files) canal preparation techniques. Secondary objectives were to determine whether there was an association of ProTaper file fracture with the canal curvature and to compare the mean time required for canal preparation in the two techniques. An in vitro experiment was conducted on 216 buccal canals of extracted maxillary and mandibular first molars. After creating an access cavity and a glide path for each canal, a periapical radiograph was taken and the canal curvature was measured with Schneider's technique. The canals were then randomly divided into Group A (rotary technique) and Group B (hybrid technique). The length of ProTaper files were measured before and after each canal preparation. Time taken for each canal preparation was recorded. A total of seven ProTaper files fractured in Group A (P=0.014) in canals with a curvature >25 degrees (PProTaper rotary files, although time consuming, was safer in canals having a curvature greater than 25 degrees.

  14. A simplified technique for polymethyl methacrylate cranioplasty: combined cotton stacking and finger fracture method.

    Science.gov (United States)

    Kung, Woon-Man; Lin, Muh-Shi

    2012-01-01

    Polymethyl methacrylate (PMMA) is one of the most frequently used cranioplasty materials. However, limitations exist with PMMA cranioplasty including longer operative time, greater blood loss and a higher infection rate. To reduce these disadvantages, it is proposed to introduce a new surgical method for PMMA cranioplasty. Retrospective review of nine patients who received nine PMMA implants using combined cotton stacking and finger fracture method from January 2008 to July 2011. The definitive height of skull defect was quantified by computer-based image analysis of computed tomography (CT) scans. Aesthetic outcomes as measured by post-reduction radiographs and cranial index of symmetry (CIS), cranial nerve V and VII function and complications (wound infection, hardware extrusions, meningitis, osteomyelitis and brain abscess) were evaluated. The mean operation time for implant moulding was 24.56 ± 4.6 minutes and 178.0 ± 53 minutes for skin-to-skin. Average blood loss was 169 mL. All post-operative radiographs revealed excellent reduction. The mean CIS score was 95.86 ± 1.36%, indicating excellent symmetry. These results indicate the safety, practicability, excellent cosmesis, craniofacial symmetry and stability of this new surgical technique.

  15. An internal conical mandrel technique for fracture toughness measurements on nuclear fuel cladding

    Energy Technology Data Exchange (ETDEWEB)

    Sainte Catherine, C.; Le Boulch, D.; Carassou, S. [CEA Saclay, DEN/DMN, Bldg 625 P, Gif-Sur-Yvette, F-91191 (France); Lemaignan, C. [CEA Grenoble, 17 rue des Martyrs, Grenoble, F-38054 (France); Ramasubramanian, N. [ECCATEC Inc., 92 Deburn Drive, Toronto, Ontario (Canada)

    2006-07-01

    An understanding of the limiting stress level for crack initiation and propagation in a fuel cladding material is a fundamental requirement for the development of water reactor clad materials. Conventional tests, in use to evaluate fracture properties, are of limited help, because they are adapted from ASTM standards designed for thick materials, which differ significantly from fuel cladding geometry (small diameter thin-walled tubing). The Internal Conical Mandrel (ICM) test described here is designed to simulate the effect of fuel pellet diametrical increase on a cladding with an existing axial through-wall crack. It consists in forcing a cone, having a tapered increase in diameter, inside the Zircaloy cladding with an initial axial crack. The aim of this work is to quantify the crack initiation and propagation criteria for fuel cladding material. The crack propagation is monitored by a video system for obtaining crack extension {delta}a. A finite-element (FE) simulation of the ICM test is performed in order to derive J integrals. A node release technique is applied during the FE simulation for crack propagation and the J-resistance curves (J-{delta}a) are generated. This paper presents the test methodology, the J computation validation, and results for cold-worked stress relieved Zircaloy-4 cladding at 20 deg. and 300 deg. C and also for Al 7050-T7651 aluminum alloy tubing at 20 deg. C. (authors)

  16. Indirect reduction technique using a distraction support in minimally invasive percutaneous plate osteosynthesis of tibial shaft fractures.

    Science.gov (United States)

    Dong, Wen-Wei; Shi, Zeng-Yuan; Liu, Zheng-Xin; Mao, Hai-Jiao

    2016-12-01

    To describe an indirect reduction technique during minimally invasive percutaneous plate osteosynthesis (MIPPO) of tibial shaft fractures with the use of a distraction support. Between March 2011 and October 2014, 52 patients with a mean age of 48 years (16-72 years) sustaining tibial shaft fractures were included. All the patients underwent MIPPO for the fractures using a distraction support prior to insertion of the plate. Fracture angular deformity was assessed by goni- ometer measurement on preoperative and postoperative images. Preoperative radiographs revealed a mean of 7.6°(1.2°-28°) angulation in coronal plane and a mean of 6.8°(0.5°-19°) angulation in sagittal plane. Postoperative anteroposterior and lateral radio- graphs showed a mean of 0.8°(0°-4.0°) and 0.6°(0°-3.6°) of varus/valgus and apex anterior/posterior angulation, respectively. No intraoperative or postoperative complications were noted. This study suggests that the distraction support during MIPPO of tibial shaft fractures is an effective and safe method with no associated complications.

  17. [A therapeutic effect analysis of femur first principle and combined anteversion technique during total hip arthroplasty].

    Science.gov (United States)

    Wang, X Q; Wu, C S; Sun, S; Wang, J; Li, W; Zhang, W

    2018-04-01

    Objective: To investigate the situation of hip dislocation with the application of "femur first" principle and "combined anteversion technique" during total hip arthroplasty. Methods: A retrospective analysis has been done on the clinical data about 104 patients(133 hips)who were diagnosed as hip disease and were treated with total hip arthroplasty by the doctors from the Department of Joint Orthorpaedics of Shandong Provincial Hospital Affiliated to Shandong University from June 2014 to June 2016, and all the prostheses applied in the operation were cementless ones.Among them, 65 patients were males, 39 females and their age was 46.6 years (ranging from 23 to 76 years) .And 29 of them underwent bilateral hip operations and 75 unilateral ones.Seventy-six cases of aseptic necrosis of the femoral head in the terminal stage, 28 cases of hip dysplasia and osteoarthritis.Surgical approach: of all the operations, 103 hips were operated on with hardinge approach, 30 with posterolateral approach.During the operation, first of all, the femoral medullary cavity was broached and then the anteversion of intramedullary broacher was measured.After that, the anteversion of the acetabular cup was calculated as 37° minus the anteversion of the broacher, and the acetabular cup was implanted at that angle.The patients' prosthesis combined anteversion, range of motion of the hip joint, operation time, hemorrhage amount, and complications had been kept record.One, three, and six months respectively after the operation, all the patients received outpatient review, and took anteroposterior and lateral position X-ray examination.Harris hip score had been applied to evaluate their hip function before the operation and six months after the operation. Results: All the patients had been operated on smoothly, with the operation time of(57.6±14.5)minutes(36-115 minutes)and hemorrhage amount of (336.5±50.8)ml(180-620 ml). The operation finding showed that the combined anteversion by employing

  18. Results of Patello-Tibial Cerclage Wire Technique for Comminuted Patella Fractures Treated with Partial Patellectomy

    Directory of Open Access Journals (Sweden)

    Ender Alagöz

    2014-12-01

    Full Text Available Aim: Partial patellectomy and patellotibial cerclage technique used in comminuted inferior pole patellar fractures were evaluated and the results were discussed. Methods: Thirteen patients who have undergone partial distal patellar excision were evaluated in the study. In all patients, the inferior pole of the patella was resected, patellar tendon was sutured to the proximal patellar fragment and patellotibial cerclage was performed. At the last visit, the patients were evaluated using measurement of the distance between the superior pole of the patella and the tibial tubercle, the Lysholm knee scoring scale, knee range of motion and thigh circumference measurement. Results: The mean flexion value was 131.10 (±4.6 in normal knees and 117.20 (±8.0 in operated knees. The mean thigh diameter was 49.5 (±3.7 cm and 46.4 (±4.5 cm in normal knees and in operated knees, respectively. The mean Lysholm knee score in the patient group was 84.3 (±17.1 points. The mean distance between the superior pole of the patella and the tibial tubercle was 10.6 (±1.0 cm in normal knees and 10.1 (±1.2 cm in operated knees. The exstensor mechanism was intact in all patients and no revision surgery was performed. Conclusion: Patellotibial cerclage technique performed after partial patellectomy permits early motion and protects patients from harmful effects of immobilization; and good functional results are obtained if patients start early knee motion.

  19. General principles governing sampling and measurement techniques for monitoring radioactive effluents from nuclear facilities

    International Nuclear Information System (INIS)

    Fitoussi, L.

    1978-01-01

    An explanation is given of the need to monitor the release of radioactive gases and liquid effluents from nuclear facilities, with particular emphasis on the ICRP recommendations and on the interest in this problem shown by the larger international organizations. This is followed by a description of the classes of radionuclides that are normally monitored in this way. The characteristics of monitoring 'in line' and 'by sample taking' are described; the disadvantages of in line monitoring and the problem of sample representativity are discussed. There follows an account of the general principles for measuring gaseous and liquid effluents that are applied in the techniques normally employed at nuclear facilities. Standards relating to the specifications for monitoring instruments are at present being devised by the International Electrotechnical Commission, and there are still major differences in national practices, at least as far as measurement thresholds are concerned. In conclusion, it is shown that harmonization of practices and standardization of equipment would probably help to make international relations in the field more productive. (author)

  20. Principles, techniques and recent advances in fine particle aggregation for solid-liquid separation

    International Nuclear Information System (INIS)

    Somasundaran, P.; Vasudevan, T.V.

    1993-01-01

    Waste water discharged from various chemical and nuclear processing operations contains dissolved metal species that are highly toxic and, in some cases, radioactive. When the waste is acidic in nature, neutralization using reagents such as lime is commonly practiced to reduce both the acidity and the amount of waste (Kuyucak et al.). The sludge that results from the neutralization process contains metal oxide or hydroxide precipitates that are colloidal in nature and is highly stable. Destabilization of colloidal suspensions can be achieved by aggregation of fines into larger sized agglomerates. Aggregation of fines is a complex phenomenon involving a multitude of forces that control the interparticle interaction. In order to understand the colloidal behavior of suspensions a fundamental knowledge of physicochemical properties that determine the various forces is essential. In this review, a discussion of basic principles governing the aggregation of colloidal fines, various ways in which interparticle forces can be manipulated to achieve the desired aggregation response and recent advances in experimental techniques to probe the interfacial characteristics that control the flocculation behavior are discussed

  1. Principles of the NATM and other uses of the geologic monitoring techniques

    International Nuclear Information System (INIS)

    Jenkins, J.D.; Sander, H.J.

    1991-01-01

    The NATM (New Austrian Tunneling Method) differs in several respects from other construction methods. Also referred to as the open-quotes sequential method,close quotes or the open-quotes observational tunneling method,close quotes NATM offers outstanding flexibility by extending the design into the construction phase. Geologic monitoring of the underground opening (tunnel, shaft or cavern) on an on-going basis provides the means by which the precise support measures and tunnel advance sequence may be matched to varying rock conditions. The pragmatic principles, developed and perfected by NATM Engineers, depend upon sophisticated in situ monitoring of rock conditions on an ongoing basis. These same monitoring techniques, born of the need to determine safe, efficient ground support, are also utilized in the long term checking of existing tunnels. In addition, the instrumentation and program systems of NATM can provide accurate measurements to meet many of the site characterization requirements of underground nuclear repositories even when employed in combination with mechanical excavation

  2. Least possible fixation techniques of 4-part valgus impacted fractures of the proximal humerus: a systematic review

    Directory of Open Access Journals (Sweden)

    Andreas Panagopoulos

    2016-03-01

    Full Text Available The valgus-impacted (VI 4-part fractures are a subset of fractures of the proximal humerus with a unique anatomic configuration characterized by a relatively lower incidence of avascular necrosis after operative intervention. We systematically reviewed clinical studies assessing the benefits and harms of least possible fixation techniques (LPFT for this unique fracture type. Such information would be potentially helpful in developing an evidence-based approach in the management of these complex injuries. We performed analytic searches of PubMed, Embase, Web of Science, Google Scholar and the Cochrane Library, restricting it to the years 1991-2014. Included studies had to describe outcomes and complications after primary osteosynthesis with any type of LPFT apart from plate-screws and intramedullary nailing. Eligibility criteria were also included English language, more than 5 cases, minimum follow up of one year and report of clinical outcome using at least one relevant score (Constant, Neer or ASES. Based on 292 database hits we identified 12 eligible studies including 190 four-part valgus impacted fractures in 188 patients. All eligible studies were case series composed of min 8 to max 45 patients per study. The gender distribution was 60% (112 female and 40% (76 male. The average age of the patients at the time of injury was 54.5 years. In 8/12 studies an open reduction was used for fracture fixation using different surgical techniques including KW, cerclage wires, cannulated screws and osteosutures. Closed reduction and percutaneous fixation was used in 4 studies. Mean follow-up time ranged from 24 to 69 months. A good functional outcome (constant score >80 was reported in 9/12 studies. The most common complication was avascular necrosis of the humeral head with an overall incidence of 11% (range, 0-26.3%. Total avascular necrosis (AVN was found in 15/188 patients (7.9% and was more common in percutaneous techniques and partial AVN in 6

  3. Modified Labial Button Technique for Maintaining Occlusion After Caudal Mandibular Fracture/Temporomandibular Joint Luxation in the Cat.

    Science.gov (United States)

    Goodman, Alice E; Carmichael, Daniel T

    2016-03-01

    Maxillofacial trauma in cats often results in mandibular symphyseal separation in addition to injuries of the caudal mandible and/or temporomandibular joint (TMJ). Caudal mandibular and TMJ injuries are difficult to access and stabilize using direct fixation techniques, thus indirect fixation is commonly employed. The immediate goals of fixation include stabilization for return to normal occlusion and function with the long-term objective of bony union. Indirect fixation techniques commonly used for stabilization of caudal mandibular and temporomandibular joint fracture/luxation include maxillomandibular fixation (MMF) with acrylic composite, interarcade wiring, tape muzzles, and the bignathic encircling and retaining device (BEARD) technique. This article introduces a modification of the previously described "labial reverse suture through buttons" technique used by Koestlin et al and the "labial locking with buttons" technique by Rocha et al. In cases with minimally displaced subcondylar and pericondylar fractures without joint involvement, the labial button technique can provide sufficient stabilization for healing. Advantages of the modified labial button technique include ease of application, noninvasive nature, and use of readily available materials. The construct can remain in place for a variable of amount of time, depending on its intended purpose. It serves as an alternative to the tape muzzle, which is rarely tolerated by cats. This technique can be easily used in conjunction with other maxillomandibular repairs, such as cerclage wire fixation of mandibular symphyseal separation. The purpose of this article is to demonstrate a modified labial button technique for maintaining occlusion of feline caudal mandibular fractures/TMJ luxations in a step-by-step fashion.

  4. Fracture of coherent interfaces between an fcc metal matrix and the Cr23C6 carbide precipitate from first principles

    Science.gov (United States)

    Barbé, Elric; Fu, Chu-Chun; Sauzay, Maxime

    2018-02-01

    It is known that microcrack initiation in metallic alloys containing second-phase particles may be caused by either an interfacial or an intraprecipitate fracture. So far, the dependence of these features on properties of the precipitate and the interface is not clearly known. The present study aims to determine the key properties of carbide-metal interfaces controlling the energy and critical stress of fracture, based on density functional theory (DFT) calculations. We address coherent interfaces between a fcc iron or nickel matrix and a frequently observed carbide, the M23C6 , for which a simplified chemical composition Cr23C6 is assumed. The interfacial properties such as the formation and Griffith energies, and the effective Young's modulus are analyzed as functions of the magnetic state of the metal lattice, including the paramagnetic phase of iron. Interestingly, a simpler antiferromagnetic phase is found to exhibit similar interfacial mechanical behavior to the paramagnetic phase. A linear dependence is determined between the surface (and interface) energy and the variation of the number of chemical bonds weighted by the respective bond strength, which can be used to predict the relative formation energy for the surface and interface with various chemical terminations. Finally, the critical stresses of both intraprecipitate and interfacial fractures due to a tensile loading are estimated via the universal binding energy relation (UBER) model, parametrized on the DFT data. The validity of this model is verified in the case of intraprecipitate fracture, against results from DFT tensile test simulations. In agreement with experimental evidences, we predict a much stronger tendency for an interfacial fracture for this carbide. In addition, the calculated interfacial critical stresses are fully compatible with available experimental data in steels, where the interfacial carbide-matrix fracture is only observed at incoherent interfaces.

  5. Surgical stabilization of rib fractures using Inion OTPS wraps--techniques and quality of life follow-up.

    Science.gov (United States)

    Campbell, Nicole; Conaglen, Paul; Martin, Katherine; Antippa, Phillip

    2009-09-01

    A variety of operative techniques have been described in the past for the surgical stabilization of fractured ribs. From February 2004 to November 2008, consecutive patients who underwent open reduction and internal fixation of traumatic fractured ribs during their index admission using the Inion orthopedic trauma plating system (OTPS) at a Level I trauma center were retrospectively analyzed. Demographics, Injury Severity Scores, number and site of rib fractures, operative details, and complications were recorded. All patients were followed-up with a questionnaire assessing chest symptoms, disability, and quality of life. Thirty-two patients underwent surgical stabilization with Inion OTPS. Road crashes were the commonest mechanism of injury (81%), followed by falls. Seventy-two percent of patients were male, with a median age at operation of 53 years (interquartile range [IQR], 40-64 years). Median number of ribs fixed was 3 (IQR, 2-4), while median number of fractures was 9 (IQR, 6-13). Median time to fixation was 5 days (IQR, 3-7 days), intensive care unit stay 3 days (IQR, 0.8-6.3 days), and total hospital stay 13.5 days (IQR, 8.8-22 days). Wound infection occurred in 19%, with nonunion of a fixed fracture in one patient. Sixty-three percent of patients completed the survey with a mean time between open reduction and internal fixation and questionnaire of 1,039 days (+/-480 days). Patients reported low levels of pain at rest and with coughing (median at rest 1.0/10 [IQR, 0-2.3/10]; with coughing 1.3/10 [IQR, 0-3.75/10]). Chest wall stiffness was experienced by 60% of patients, while dyspnoea at rest was reported by 20% of patients. Mean return to work (for 55%) was 3.9 months (+/-3.3 months). All patients were satisfied with the results of their operation. Patients demonstrated low levels of pain and satisfactory rehabilitation. The Inion OTPS system has several advantages including gradual transference of stress loads to bone, micromotion across the fracture

  6. Fluoroscopically guided closed reduction and internal fixation of fractures of the lateral portion of the humeral condyle: prospective clinical study of the technique and results in ten dogs.

    Science.gov (United States)

    Cook, J L; Tomlinson, J L; Reed, A L

    1999-01-01

    To report a technique for fluoroscopically guided closed reduction with internal fixation of fractures of the lateral portion of the humeral condyle (FLHC) and determine the long-term results in 10 clinical cases. Prospective clinical case study. Ten dogs with 11 fractures. Fractures of the lateral portion of the humeral condyle were stabilized with transcondylar screws and Kirschner wires. Closed reduction and implant placement were achieved using intraoperative fluoroscopic guidance. After fracture repair, postoperative radiographs were evaluated for articular alignment and implant placement. Dogs were evaluated after surgery by means of lameness scores, elbow range of motion (ROM), radiographic assessment, and owner evaluation of function. Postoperative reduction was considered anatomic in 6 fractures with all other fractures having ROM values between affected and unaffected elbows. All of the dogs in this study regained 90-100% of full function, based on owner assessment. Fluoroscopic guidance for closed reduction and internal fixation of FLHC in dogs is an effective technique.

  7. Management of Gustilo Anderson III B open tibial fractures by primary fascio-septo-cutaneous local flap and primary fixation: The ′fix and shift′ technique

    Directory of Open Access Journals (Sweden)

    P R Ramasamy

    2017-01-01

    Full Text Available Background: Open fractures of tibia have posed great difficulty in managing both the soft tissue and the skeletal components of the injured limb. Gustilo Anderson III B open tibial fractures are more difficult to manage than I, II, and III A fractures. Stable skeletal fixation with immediate soft tissue cover has been the key to the successful outcome in treating open tibial fractures, in particular, Gustilo Anderson III B types. If the length of the open wound is larger and if the exposed surface of tibial fracture and tibial shaft is greater, then the management becomes still more difficult. Materials and Methods: Thirty six Gustilo Anderson III B open tibial fractures managed between June 2002 and December 2013 with "fix and shift" technique were retrospectively reviewed. All the 36 patients managed by this technique had open wounds measuring >5 cm (post debridement. Under fix and shift technique, stable fixation involved primary external fixator application or primary intramedullary nailing of the tibial fracture and immediate soft tissue cover involved septocutaneous shift, i.e., shifting of fasciocutaneous segments based on septocutaneous perforators. Results: Primary fracture union rate was 50% and reoperation rate (bone stimulating procedures was 50%. Overall fracture union rate was 100%. The rate of malunion was 14% and deep infection was 16%. Failure of septocutaneous shift was 2.7%. There was no incidence of amputation. Conclusion: Management of Gustilo Anderson III B open tibial fractures with "fix and shift" technique has resulted in better outcome in terms of skeletal factors (primary fracture union, overall union, and time for union and malunion and soft tissue factors (wound healing, flap failure, access to secondary procedures, and esthetic appearance when compared to standard methods adopted earlier. Hence, "fix and shift" could be recommended as one of the treatment modalities for open III B tibial fractures.

  8. Management of Gustilo Anderson III B open tibial fractures by primary fascio-septo-cutaneous local flap and primary fixation: The 'fix and shift' technique.

    Science.gov (United States)

    Ramasamy, P R

    2017-01-01

    Open fractures of tibia have posed great difficulty in managing both the soft tissue and the skeletal components of the injured limb. Gustilo Anderson III B open tibial fractures are more difficult to manage than I, II, and III A fractures. Stable skeletal fixation with immediate soft tissue cover has been the key to the successful outcome in treating open tibial fractures, in particular, Gustilo Anderson III B types. If the length of the open wound is larger and if the exposed surface of tibial fracture and tibial shaft is greater, then the management becomes still more difficult. Thirty six Gustilo Anderson III B open tibial fractures managed between June 2002 and December 2013 with "fix and shift" technique were retrospectively reviewed. All the 36 patients managed by this technique had open wounds measuring >5 cm (post debridement). Under fix and shift technique, stable fixation involved primary external fixator application or primary intramedullary nailing of the tibial fracture and immediate soft tissue cover involved septocutaneous shift, i.e., shifting of fasciocutaneous segments based on septocutaneous perforators. Primary fracture union rate was 50% and reoperation rate (bone stimulating procedures) was 50%. Overall fracture union rate was 100%. The rate of malunion was 14% and deep infection was 16%. Failure of septocutaneous shift was 2.7%. There was no incidence of amputation. Management of Gustilo Anderson III B open tibial fractures with "fix and shift" technique has resulted in better outcome in terms of skeletal factors (primary fracture union, overall union, and time for union and malunion) and soft tissue factors (wound healing, flap failure, access to secondary procedures, and esthetic appearance) when compared to standard methods adopted earlier. Hence, "fix and shift" could be recommended as one of the treatment modalities for open III B tibial fractures.

  9. Biomechanical comparison of two intraoperative mobilization techniques for maxillary distraction osteogenesis: Down-fracture versus non-down-fracture.

    Science.gov (United States)

    Yang, Lili; Suzuki, Eduardo Yugo; Suzuki, Boonsiva

    2014-01-01

    The purpose of this study was to compare the distraction forces and the biomechanical effects between two different intraoperative surgical procedures (down-fracture [DF] and non-DF [NDF]) for maxillary distraction osteogenesis. Eight patients were assigned into two groups according to the surgical procedure: DF, n = 6 versus NDF, n = 2. Lateral cephalograms taken preoperatively (T1), immediately after removal of the distraction device (T2), and after at least a 6 months follow-up period (T3) were analyzed. Assessment of distraction forces was performed during the distraction period. The Mann-Whitney U-test was used to compare the difference in the amount of advancement, the maximum distraction force and the amount of relapse. Although a significantly greater amount of maxillary movement was observed in the DF group (median 9.5 mm; minimum-maximum 7.9-14.1 mm) than in the NDF group (median 5.9 mm; minimum-maximum 4.4-7.6 mm), significantly lower maximum distraction forces were observed in the DF (median 16.4 N; minimum-maximum 15.1-24.6 N) than in the NDF (median 32.9 N; minimum-maximum 27.6-38.2 N) group. A significantly greater amount of dental anchorage loss was observed in the NDF group. Moreover, the amount of relapse observed in the NDF group was approximately 3.5 times greater than in the DF group. In this study, it seemed that, the use of the NDF procedure resulted in lower levels of maxillary mobility at the time of the maxillary distraction, consequently requiring greater amounts of force to advance the maxillary bone. Moreover, it also resulted in a reduced amount of maxillary movement, a greater amount of dental anchorage loss and poor treatment stability.

  10. A Technique of Teaching the Principle of Equivalence at Ground Level

    Science.gov (United States)

    Lubrica, Joel V.

    2016-01-01

    This paper presents one way of demonstrating the Principle of Equivalence in the classroom. Teaching the Principle of Equivalence involves someone experiencing acceleration through empty space, juxtaposed with the daily encounter with gravity. This classroom activity is demonstrated with a water-filled bottle containing glass marbles and…

  11. Sectional Fixed Orthodontic Extrusion Technique in Management of Teeth with Complicated Crown-Root Fractures: Report of Two Cases

    Directory of Open Access Journals (Sweden)

    S. Nagarajan M. P. Sockalingam

    2018-01-01

    Full Text Available Complicated crown-root fractures account for a small percentage of traumatic dental injuries seen in children; however, management of these injuries can be very challenging to clinicians. Factors such as complexity of the injury, patient’s age and dentition stage, patient’s cooperation, and parental demands may have some bearing on the type of treatment undertaken and its outcomes. In some children, these injuries may have significant impact on their quality of life. The purpose of this article is to describe two cases of complicated crown-root fracture which were successfully managed through orthodontic extrusion using a sectional fixed orthodontic technique. The basis for the treatment technique and its favourable outcomes were highlighted with its advantages and drawbacks.

  12. Repurposing Principles and Successful Pedagogical Techniques from Mister Rogers' Neighborhood for the Early Childhood Music Classroom

    Science.gov (United States)

    Poole, Harrison Grant

    2018-01-01

    Fred Rogers's television program, "Mister Rogers' Neighborhood", connected with young children and educated them about difficult concepts for more than 30 years. The author analyzes and discusses several principles and pedagogical techniques that were used in Rogers's television program, including communicating with children,…

  13. A versatile stereo photogrammetry based technique for measuring fracture mode displacements in structures

    DEFF Research Database (Denmark)

    Alvarado, Jonathan Shmueli; Eder, Martin Alexander; Tesauro, Angelo

    2015-01-01

    The measurement of fracture mode displacements in structures which are susceptible to cracking such as adhesive joints in composite components – is becoming increasingly important. Such measurements are essential for the understanding of the root causes for specific fracture damage types. Further......The measurement of fracture mode displacements in structures which are susceptible to cracking such as adhesive joints in composite components – is becoming increasingly important. Such measurements are essential for the understanding of the root causes for specific fracture damage types......-made automated image processing software (AIPS) allows a rapid and reliable evaluation of a multitude of subsequently taken measurements at a high-precision level. The SDMS is used to measure the LRDs at three different locations close to the trailing edge of a wind turbine rotor blade. In addition...

  14. Development of Numerical Analysis Techniques Based on Damage Mechanics and Fracture Mechanics

    International Nuclear Information System (INIS)

    Chang, Yoon Suk; Lee, Dock Jin; Choi, Shin Beom; Kim, Sun Hye; Cho, Doo Ho; Lee, Hyun Boo

    2010-04-01

    The scatter of measured fracture toughness data and transferability problems among different crack configurations as well as geometry and loading conditions are major obstacles for application of fracture mechanics. To address these issues, recently, concerns on the local approach employing reliable micro-mechanical damage models are being increased again in connection with a progress of computational technology. In the present research, as part of development of fracture mechanical evaluation model for material degradation of reactor pressure boundary, several investigations on fracture behaviors were carried out. Especially, a numerical scheme to determine key parameters consisting both cleavage and ductile fracture estimate models was changed efficiently by incorporating a genetic algorithm. Also, with regard to the well-known master curve, newly reported methods such as bimodal master curve, randomly inhomogeneous master curve and single point estimation were reviewed to deal with homogeneous and inhomogeneous material characteristics. A series of preliminary finite element analyses was conducted to examine the element size effect on micro-mechanical models. Then, a new thickness correction equation was derived from parametric three-dimensional numerical simulations, which was founded on the current test standard, ASTM E1921, but could lead to get more realistic fracture toughness values. As a result, promising modified master curves as well as fracture toughness diagrams to convert data between pre-cracked V-notched and compact tension specimens were generated. Moreover, a user-subroutine in relation to GTN(Gurson-Tvergaard-Needleman) model was made by adopting Hill's 48 yield potential theory. By applying GTN model combined with the subroutine to small punch specimens, the effect of inhomogeneous properties on fracture behaviors of miniature specimens was confirmed. Therefore, it is anticipated that the aforementioned enhanced research results can be utilized

  15. Applying physiological principles and assessment techniques to swimming the English Channel. A case study.

    Science.gov (United States)

    Acevedo, E O; Meyers, M C; Hayman, M; Haskin, J

    1997-03-01

    This study presents the use of physiological principles and assessment techniques in addressing four objectives that can enhance a swimmer's likelihood of successfully swimming the English Channel. The four objective were: (1) to prescribe training intensities and determine ideal swimming pace; (2) to determine the amount of insulation needed, relative to heat produced, to diminish the likelihood of the swimmer suffering from hypothermia; (3) to calculate the caloric expenditure for the swim and the necessary glucose replacement required to prevent glycogen depletion; and (4) to determine the rate of acclimatization to cold water (15.56 C/60 F). The subject participated in several pool swimming data collection sessions including a tethered swim incremental protocol to determine peak oxygen consumption and onset of lactate accumulation and several steady state swims to determine ideal swimming pace at 4.0 mM/L of lactate. Additionally, these swims provided information on oxygen consumption, which in combination with ultrasound assessment of subcutaneous fat was used to assess heat production and insulation capabilities. Finally, the subject participated in 18 cold water immersions to document acclimatization rate. The data demonstrated the high fitness level of this subject and indicated that at a stroke rate of 63 stokes/min, HR was 130 heats/min and lactate was 4 mM/L. At this swimming pace the swimmer would need to consume 470 kcal of glucose/hr. In addition, the energy produced at this swim pace was 13.25 kcal/min while the energy lost at the present subcutaneous fat quantity was 13.40 kcal/min, requiring a fat weight gain of 6,363.03 g (13.88 lbs) to resist heat loss. Finally, the data from the cold water immersions suggested that acclimatization occurred following two weeks of immersions. There results were provided to the swimmer and utilized in making decisions in preparation for the swim.

  16. Comparison of Neck Screw and Conventional Fixation Techniques in Mandibular Condyle Fractures Using 3-Dimensional Finite Element Analysis.

    Science.gov (United States)

    Conci, Ricardo Augusto; Tomazi, Flavio Henrique Silveira; Noritomi, Pedro Yoshito; da Silva, Jorge Vicente Lopes; Fritscher, Guilherme Genehr; Heitz, Claiton

    2015-07-01

    To compare the mechanical stress on the mandibular condyle after the reduction and fixation of mandibular condylar fractures using the neck screw and 2 other conventional techniques according to 3-dimensional finite element analysis. A 3-dimensional finite element model of a mandible was created and graphically simulated on a computer screen. The model was fixed with 3 different techniques: a 2.0-mm plate with 4 screws, 2 plates (1 1.5-mm plate and 1 2.0-mm plate) with 4 screws, and a neck screw. Loads were applied that simulated muscular action, with restrictions of the upper movements of the mandible, differentiation of the cortical and medullary bone, and the virtual "folds" of the plates and screws so that they could adjust to the condylar surface. Afterward, the data were exported for graphic visualization of the results and quantitative analysis was performed. The 2-plate technique exhibited better stability in regard to displacement of fractures, deformity of the synthesis materials, and minimum and maximum tension values. The results with the neck screw were satisfactory and were similar to those found when a miniplate was used. Although the study shows that 2 isolated plates yielded better results compared with the other groups using other fixation systems and methods, the neck screw could be an option for condylar fracture reduction. Copyright © 2015 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

  17. Survey to explore understanding of the principles of aseptic technique: Qualitative content analysis with descriptive analysis of confidence and training.

    Science.gov (United States)

    Gould, Dinah J; Chudleigh, Jane; Purssell, Edward; Hawker, Clare; Gaze, Sarah; James, Deborah; Lynch, Mary; Pope, Nicola; Drey, Nicholas

    2018-04-01

    In many countries, aseptic procedures are undertaken by nurses in the general ward setting, but variation in practice has been reported, and evidence indicates that the principles underpinning aseptic technique are not well understood. A survey was conducted, employing a brief, purpose-designed, self-reported questionnaire. The response rate was 72%. Of those responding, 65% of nurses described aseptic technique in terms of the procedure used to undertake it, and 46% understood the principles of asepsis. The related concepts of cleanliness and sterilization were frequently confused with one another. Additionally, 72% reported that they not had received training for at least 5 years; 92% were confident of their ability to apply aseptic technique; and 90% reported that they had not been reassessed since their initial training. Qualitative analysis confirmed a lack of clarity about the meaning of aseptic technique. Nurses' understanding of aseptic technique and the concepts of sterility and cleanliness is inadequate, a finding in line with results of previous studies. This knowledge gap potentially places patients at risk. Nurses' understanding of the principles of asepsis could be improved. Further studies should establish the generalizability of the study findings. Possible improvements include renewed emphasis during initial nurse education, greater opportunity for updating knowledge and skills post-qualification, and audit of practice. Copyright © 2018 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

  18. Aspects of internal fixation of fractures in porotic bone. Principles, technologies and procedures using locked plate screws.

    Science.gov (United States)

    Perren, S M; Linke, B; Schwieger, K; Wahl, D; Schneider, E

    2005-01-01

    Fractures of the bones of elderly people occur more often and have a more important effect because of a generally diminished ability to coordinate stance and walking. These fractures occur at a lower level of load because of lack of strength of the porotic bone. Prompt recovery of skeletal support function is essential to avoid respiratory and circulatory complications in the elderly. To prevent elderly people from the risks of being bedridden, demanding internal fixation of fractures is required. The weak porotic bone and the high level of uncontrolled loading after internal fixation pose complex problems. A combination of several technical elements of design, application and aftercare in internal fixation are proposed. Internal fixators with locked screws improve the biology and the mechanics of internal fixation. When such fixators are used as elevated splints they may stimulate early callus formation because of their flexibility, the limit of flexibility being set by the demands of resistance and function of the limb. Our own studies of triangulation of locked screws have demonstrated their beneficial effects and unexpected limitations.

  19. Mandible Fractures.

    Science.gov (United States)

    Pickrell, Brent B; Serebrakian, Arman T; Maricevich, Renata S

    2017-05-01

    Mandible fractures account for a significant portion of maxillofacial injuries and the evaluation, diagnosis, and management of these fractures remain challenging despite improved imaging technology and fixation techniques. Understanding appropriate surgical management can prevent complications such as malocclusion, pain, and revision procedures. Depending on the type and location of the fractures, various open and closed surgical reduction techniques can be utilized. In this article, the authors review the diagnostic evaluation, treatment options, and common complications of mandible fractures. Special considerations are described for pediatric and atrophic mandibles.

  20. Combining NDE and fracture mechanics by artifical intelligence expert systems techniques

    International Nuclear Information System (INIS)

    Mucciardi, A.N.; Riccardella, P.C.

    1986-01-01

    This paper reports on the development of a PC-based expert system for non-destructive evaluation. Software tools from the expert systems subfield of artificial intelligence are being used to combine both NDE and fracture mechanics algorithms into one, unified package. The system incorporates elements of computer-enhanced ultrasonic signal processing, featuring artificial intelligence learning capability, state-of-the-art fracture mechanics analytical tools, and all relevant metallurgical and design data necessary to emulate the decisions of the panel(s) of experts typically involved in generating and dispositioning NDE data

  1. Minimally invasive plate osteosynthesis for humeral shaft fracture: a reproducible technique with the assistance of an external fixator.

    Science.gov (United States)

    Lee, Hyun-Joo; Oh, Chang-Wug; Oh, Jong-Keon; Apivatthakakul, Theerachai; Kim, Joon-Woo; Yoon, Jong-Pil; Lee, Dong-Joo; Jung, Jae-Wook

    2013-05-01

    Minimally invasive plate osteosynthesis (MIPO) has become a popular option for treatment of humeral shaft fractures. However, indirect reduction might risk unpromising results, with mal-alignment/mal-union or nonunion. The purpose of this study was to describe a reproducible MIPO technique that used an external fixator during the procedure as a tool for reduction and maintenance, and to assess the outcomes in patients with humeral shaft fracture. Of 31 consecutive cases of humeral shaft fracture in 30 patients, 29 were included in this study. There were seven simple (type A) and 22 comminuted (type B or C) fractures. After the insertion of one Schanz pin on each proximal and distal humerus, a provisional reduction was achieved by connecting the pins with a monolateral external fixator. The MIPO procedure was then performed over the anterior aspect of the humerus. To evaluate the efficacy of the provisional reduction by external fixator, coronal and sagittal alignments were assessed. We also assessed bony and functional results, including complications, from this technique. There was no case of mal-union >10°, and mean angulation was 1.3° (range 0°-9°) in the coronal plane and 1.2° (range 0°-8°) in the sagittal plane. Twenty-eight of 29 fractures were united, including three delayed unions, with a mean union time of 19.1 weeks (range 12.3-38.4 weeks) and a mean follow-up of 20.8 months (range 13.5-31.0 months). There was one hypertrophic nonunion that healed after fixing with two additional screws. Except one patient with associated injury in the elbow, all patients recovered to pre-injury joint motion. There were two cases of postoperative radial nerve palsy that both recovered completely. We attributed them to manipulation, and not to the Schanz pins or plate fixation. Surgical treatment of humeral shaft fractures with external fixator-assisted reduction and MIPO resulted in excellent reductions and high union rates.

  2. Novel Principles and Techniques to Create a Natural Design in Female Hairline Correction Surgery.

    Science.gov (United States)

    Park, Jae Hyun

    2015-12-01

    Female hairline correction surgery is becoming increasingly popular. However, no guidelines or methods of female hairline design have been introduced to date. The purpose of this study was to create an initial framework based on the novel principles of female hairline design and then use artistic ability and experience to fine tune this framework. An understanding of the concept of 5 areas (frontal area, frontotemporal recess area, temporal peak, infratemple area, and sideburns) and 5 points (C, A, B, T, and S) is required for female hairline correction surgery (the 5A5P principle). The general concepts of female hairline correction surgery and natural design methods are, herein, explained with a focus on the correlations between these 5 areas and 5 points. A natural and aesthetic female hairline can be created with application of the above-mentioned concepts. The 5A5P principle of forming the female hairline is very useful in female hairline correction surgery.

  3. [Kirschner wire transfixation of unstable ankle fractures: indication, surgical technique and outcomes].

    Science.gov (United States)

    Marvan, J; Džupa, V; Bartoška, R; Kachlík, D; Krbec, M; Báča, V

    2015-01-01

    PURPOSE OF THE STUDY The aim of the study was to assess treatment outcomes in patients undergoing K-wire transfixation of unstable ankle fractures and compare the results with those of patients in whom it was possible to perform primary one-stage osteosynthesis. MATERIAL AND METHODS Between 2009 and 2012, a total of 358 patients (191 women and 167 men) had surgery for unstable ankle fracture. At 1-year follow-up, their subjective feelings, objective findings and ankle radiographs were evaluated. The fractures were categorised according to the Weber classification. A patient group treated by one-stage osteosynthesis, a group with definitive transfixation and a group of patients in whom temporary transfixation was converted to definitive osteosynthesis were assessed and compared. RESULTS The group treated by one-stage osteosynthesis included 278 patients with an average age of 47 years; the group of 20 patients with definitive transfixation had an average age of 67 years, and the group of 60 patients who had temporary transfixation with subsequent conversion to internal osteosynthesis were 55 years on average. In the group with one-stage osteosynthesis, 223 (80%) ankle fractures on post-injury radiographs were associated with minor joint dislocations and 55 (20%) with major dislocations. On the other hand, the radiographs of the patients treated by temporary transfixation and delayed open reduction with internal fixation showed major dislocations in 38 (63%) and minor dislocations in the rest of the patients (37%); the difference between the two groups was statistically significant (pfractures were most frequent in the group with temporary transfixation (60%) and least frequent in the group with primary osteosynthesis (44%); also this difference was statistically significant (p=0.032). At one-year follow-up, in the group with one-stage osteosynthesis, 220 patients (79%) had no radiographic signs of posttraumatic ankle osteoarthritis while, in the group with temporary

  4. Public Relations for Brazilian Libraries: Process, Principles, Program Planning, Planning Techniques and Suggestions.

    Science.gov (United States)

    Kies, Cosette N.

    A brief overview of the functions of public relations in libraries introduces this manual, which provides an explanation of the public relations (PR) process, including fact-finding, planning, communicating, evaluating, and marketing; some PR principles; a 10-step program that could serve as a model for planning a PR program; a discussion of PR…

  5. Adhesion and fracture toughness at α-Ti(0 0 0 1)/TiC(1 1 1): A first-principles investigation

    International Nuclear Information System (INIS)

    Li, Jian; Yang, Yanqing; Feng, Guanghai; Luo, Xian; Sun, Qing; Jin, Na

    2013-01-01

    The interfacial properties of α-Ti(0 0 0 1)/TiC(1 1 1) interface, such as adhesion, interface energy, interfacial fracture toughness, bonding nature, are investigated using first-principles calculations. Six interface models with different TiC(1 1 1) termination and stacking sites are investigated to clarify their influence on the interfacial stability and adhesion strength. C-terminated-hollow-site and Ti-terminated-center-site models exhibit identical epitaxial stacking style after fully relaxation, and can be regarded as the Ti and TiC sides of the most stable and strongest interface. The possible negative interface energy indicates the interfacial diffusion, and even new phase formation, is likely to happen across the interface. The largest interfacial fracture toughness is estimated about 4.8 MPa m 1/2 . The valence electron density and partial density of states (PDOS) indicate that its interfacial bonding is mainly contributed from C-Ti covalent bonds and Ti-Ti metallic interaction.

  6. Semiextended approach for intramedullary nailing via a patellar eversion technique for tibial-shaft fractures: Evaluation of the patellofemoral joint.

    Science.gov (United States)

    Yasuda, Tomohiro; Obara, Shu; Hayashi, Junji; Arai, Masayuki; Sato, Kaoru

    2017-06-01

    Intramedullary nail fixation is a common treatment for tibial-shaft fractures, and it offers a better functional prognosis than other conservative treatments. Currently, the primary approach employed during intramedullary nail insertion is the semiextended position is the suprapatellar approach, which involves a vertical incision of the quadriceps tendon Damage to the patellofemoral joint cartilage has been highlighted as a drawback associated with this approach. To avoid this issue, we perform surgery using the patellar eversion technique and a soft sleeve. This method allows the articular surface to be monitored during intramedullary nail insertion. We arthroscopically assessed the effect of this technique on patellofemoral joint cartilage. The patellar eversion technique allows a direct view and protection of the patellofemoral joint without affecting the patella. Thus, damage to the patellofemoral joint cartilage can be avoided. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Energy release rate analysis on the interface cracks of enamel-cement-bracket fracture using virtual crack closure technique

    Science.gov (United States)

    Samshuri, S. F.; Daud, R.; Rojan, M. A.; Mat, F.; Basaruddin, K. S.; Hassan, R.

    2017-10-01

    This paper presents the energy method to evaluate fracture behavior of enamel-cement-bracket system based on cement thickness. Finite element (FE) model of enamel-cement-bracket was constructed by using ANSYS Parametric Design Language (APDL). Three different thickness were used in this study, 0.05, 0.2, and 0.271 mm which assigned as thin, medium and thick for both enamel-cement and cement bracket interface cracks. Virtual crack closure technique (VCCT) was implemented as a simulation method to calculated energy release rate (ERR). Simulation results were obtained for each thickness are discussed by using Griffith’s energy balance approach. ERR for thin thickness are found to be the lowest compared to medium and thick. Peak value of ERR also showed a significant different between medium and thick thickness. Therefore, weakest bonding occurred at low cement thickness because less load required to produce enough energy to detach the bracket. For medium and thick thickness, both increased rapidly in energy value at about the mid-point of the enamel-cement interface. This behavior occurred because of the increasing in mechanical and surface energy when the cracks are increasing. However, result for thick thickness are higher at mid-point compared to thin thickness. In conclusion, fracture behavior of enamel cracking process for medium most likely the safest to avoid enamel fracture and withstand bracket debonding.

  8. Complicated Crown-Root Fracture Treated Using Reattachment Procedure: A Single Visit Technique

    Directory of Open Access Journals (Sweden)

    Akhil Rajput

    2011-01-01

    Full Text Available Complicated crown-root fracture of maxillary central and lateral incisors is common in case of severe trauma or sports-related injury. It happens because of their anterior positioning in oral cavity and protrusive eruptive pattern. On their first dental visit, these patients are in pain and need emergency care. Because of impaired function, esthetics, and phonetics, such patients are quite apprehensive during their emergency visit. Successful pain management with immediate restoration of function, esthetics and phonetics should be the prime objective while handling such cases. This paper describes immediate treatment of oblique crown root fracture of maxillary right lateral incisor with reattachment procedure using light transmitting fiber post. After two and half years, the reattached fragment still has satisfying esthetics and excellent function.

  9. The hematoma block: a simple, effective technique for closed reduction of ankle fracture dislocations.

    Science.gov (United States)

    Ross, Adrianne; Catanzariti, Alan R; Mendicino, Robert W

    2011-01-01

    Management of a dislocated ankle fracture can be challenging because of instability of the ankle mortise, a compromised soft tissue envelope, and the potential neurovascular compromise. Every effort should be made to quickly and efficiently relocate the disrupted ankle joint. Within the emergency department setting, narcotics and benzodiazepines can be used to sedate the patient before attempting closed reduction. The combination of narcotics and benzodiazepines provides relief of pain and muscle guarding; however, it conveys a risk of seizure as well as respiratory arrest. An alternative to conscious sedation is the hematoma block, or an intra-articular local anesthetic injection in the ankle joint and the associated fracture hematoma. The hematoma block offers a comparable amount of analgesia to conscious sedation without the additional cardiovascular risk, hospital cost, and procedure time. Copyright © 2011 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

  10. Management of displaced inferior patellar pole fractures with modified tension band technique combined with cable cerclage using Cable Grip System.

    Science.gov (United States)

    Yang, Xu; Wu, Qinfen; Lai, Chin-Hui; Wang, Xin

    2017-10-01

    We present a modified tension band technique combined with cable cerclage using Cable Grip System for the treatment of displaced inferior patellar pole fractures and report the knee functional outcome. The patients who had had operative treatment of a displaced inferior patellar pole fracture (AO/OTA 34-A1) between December 2013 and December 2015 were studied retrospectively. Eleven consecutive patients had had open reduction and internal fixation with the modified technique using Cable Grip System, of whom, five males and six females with an average age of 60.9 years (range, 29-81 years). All fractures occurred from direct fall onto the knee. The average time from injury to surgery was 6.1days (range, 2-12days). The range of motion (ROM) was measured in degrees by goniometry at postoperative intervals of 1, 2, 4, 12, and 48 weeks; Knee function was evaluated using the Rasmussen scores at final follow-up. No patients had nonunion, loss of reduction, migration of wire, irritation from the implant and fixation breakage during the follow-up period. Recovery of ROM was achieved at 12 weeks, with the average ROM at 1 week was 72° (range, 65°-78°), 86.4° (range, 78°-92°) at 2 weeks, 115.5° (range, 103°-122°) at 4 weeks, 129.6° (range, 122°-133°) at 12 weeks, 134.5° (range, 129°-139°) at 48 weeks after the operation. Concerning the knee function outcome assessment, all patients showed excellent results at final follow-up. The average Rasmussen scores was 27.9 out of 30 (range, 27-29). The modified tension band technique combined with cable cerclage using Cable Grip System for displaced inferior patellar pole fractures can provide stable fixation with excellent results in knee function, allows for immediate mobilization and early weight-bearing, which is a simple and valuable technique in routine clinical practice. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. New quantitative ultrasound techniques for bone analysis at the distal radius in hip fracture cases: differences between femoral neck and trochanteric fractures.

    Science.gov (United States)

    Horii, Motoyuki; Fujiwara, Hiroyoshi; Sakai, Ryo; Sawada, Koshiro; Mikami, Yasuo; Toyama, Syogo; Ozaki, Etsuko; Kuriyama, Nagato; Kurokawa, Masao; Kubo, Toshikazu

    2017-01-01

    Ample evidence on etiological and pathological differences between femoral neck and trochanteric fracture cases suggests the possibility of individualized treatment. There are many issues related to areal bone mineral density and other quantitative computed tomography parameters of the proximal femur. Although osteoporosis is a systemic problem, little has been reported regarding differences in bone structural parameters, including bone mineral density, between them in regions other than the proximal femur. Participants were consecutive female patients >50 years of age admitted to the Saiseikai Suita Hospital (Osaka prefecture, Japan) for their first hip fracture between January 2012 and September 2014. Cortical thickness (CoTh, mm), volumetric trabecular bone mineral density (TBD, mg/cm 3 ), and elastic modulus of trabecular bone (EMTb, GPa) were obtained as the new QUS parameters using the LD-100 system (Oyo Electric, Kyoto, Japan). The mean values of these parameters were compared between femoral neck and trochanteric fracture cases. In addition, correlations between age and each QUS parameter were investigated for each fracture type. A receiver operating characteristic (ROC) curve analysis was performed to examine the degree of effect each parameter on the fracture types. The area under the curve (AUC) for each parameter was compared to the AUC for age. There were 63 cases of femoral neck fracture (mean age, 78.2 years) and 37 cases of trochanteric fracture (mean age, 85.9 years). Mean TBD and EMTb were significantly higher for femoral neck fractures. There were significant negative correlations between QUS parameters and age for femoral neck fractures (P fractures were above those for trochanteric fractures for TBD and EMTb. AUCs were 0.72 for age, and 0.61, 0.65, and 0.65 for CoTh, TBD, and EMTb, respectively. The new QUS parameters indicated that TR fracture cases were more osteoporotic than were FN fracture cases, even at the distal radius. There might be

  12. Modified Carpal Box Technique in the Diagnosis of Suspected Scaphoid Fractures

    Energy Technology Data Exchange (ETDEWEB)

    Toth, F.; Mester, S.; Cseh, G.; Bener, A.; Nyarady, J.; Lovasz, G. [Pecs Univ. (Hungary). Medical School

    2003-05-01

    Purpose: To establish and test the clinical efficacy of a new diagnostic algorithm with the extensive utilization of modified carpal box radiography (mX-CB) in the detection of scaphoid fractures. Material and Methods: Initial and early follow-up radiographic evaluation of 146 suspected scaphoid fractures were carried out by mX-CB. Patients with unconfirmed diagnosis were referred to CT. Patients were followed for 1 year after injury. Sensitivity, specificity and interobserver agreement of reading mX-CB images were determined statistically. Results: No non-union or avascular necrosis was seen at 1 year after the injury. 90% of the fractures were diagnosed by mX-CB, only 6.8% of the patients needed referral to CT. Sensitivity of mX-CB at initial presentation was 81.6%. Interobserver agreement was very high among evaluators of mX-CB images. Conclusion: Extensive utilization of mX-CB as primary and early follow-up investigation resulted in high initial diagnostic accuracy and low referral rate to a more expensive diagnostic modality.

  13. Robotic technique improves entry point alignment for intramedullary nailing of femur fractures compared to the conventional technique: a cadaveric study.

    Science.gov (United States)

    Suero, Eduardo M; Westphal, Ralf; Citak, Musa; Hawi, Nael; Liodakis, Emmanouil; Krettek, Christian; Stuebig, Timo

    2017-08-11

    We aimed to test whether a robotic technique would offer more accurate access to the proximal femoral medullary cavity for insertion of an intramedullary nail compared to the conventional manual technique. The medullary cavity of ten femur specimens was accessed in a conventional fashion using fluoroscopic control. In ten additional femur specimens, ISO-C 3D scans were obtained and a computer program calculated the ideal location of the cavity opening based on the trajectory of the medullary canal. In both techniques, the surgeon opened the cavity using a drill and inserted a radiopaque tube that matched the diameter of the cavity. The mean difference in angle between the proximal opening and the medullary canal in the shaft of the femur was calculated for both groups. Robotic cavity opening was more accurate than the manual technique, with a mean difference in trajectory between the proximal opening and the shaft canal of 2.0° (95% CI 0.6°-3.5°) compared to a mean difference of 4.3° (95% CI 2.11°-6.48°) using the manual technique (P = 0.0218). The robotic technique was more accurate than the manual procedure for identifying the optimal location for opening the medullary canal for insertion of an intramedullary nail. Additional advantages may include a reduction in total radiation exposure, as only one ISO-C 3D scan is needed, as opposed to multiple radiographs when using the manual technique.

  14. Balloon osteoplasty--a new technique for reduction and stabilisation of impression fractures in the tibial plateau: a cadaver study and first clinical application.

    Science.gov (United States)

    Ahrens, Philipp; Sandmann, Gunther; Bauer, Jan; König, Benjamin; Martetschläger, Frank; Müller, Dirk; Siebenlist, Sebastian; Kirchhoff, Chlodwig; Neumaier, Markus; Biberthaler, Peter; Stöckle, Ulrich; Freude, Thomas

    2012-09-01

    Fractures of the tibial plateau are among the most severe injuries of the knee joint and lead to advanced gonarthrosis if the reduction does not restore perfect joint congruency. Many different reduction techniques focusing on open surgical procedures have been described in the past. In this context we would like to introduce a novel technique which was first tested in a cadaver setup and has undergone its successful first clinical application. Since kyphoplasty demonstrated effective ways of anatomical correction in spine fractures, we adapted the inflatable instruments and used the balloon technique to reduce depressed fragments of the tibial plateau. The technique enabled us to restore a congruent cartilage surface and bone reduction. In this technique we see a useful new method to reduce depressed fractures of the tibial plateau with the advantages of low collateral damage as it is known from minimally invasive procedures.

  15. A modified surgical technique for neglected fracture of lateral humeral condyle in children.

    Science.gov (United States)

    Sulaiman, Abdul Razak; Munajat, Ismail; Mohd, Emil Fazliq

    2011-11-01

    Operative treatment for neglected fracture of lateral humeral condyle (LHC) is difficult because of contracted muscle, fibrous tissue formation, and indistinct bony edges. Its success depends on the ability to preserve blood supply during the surgery. We retrospectively reviewed eight cases of neglected fracture of LHC in children treated with open reduction with selected multiple 'V' lengthening of common extensor muscle and internal fixation. The patients were between 3 and 8 years of age. The period of neglect was between 3 and 20 weeks. Four patients with displacement of more than 10 mm and neglect for 5 weeks or more required lengthening of common extensor muscle aponeurosis. The follow-up assessments were between 1 and 6.3 years with a mean of 4.4 years. All patients had union by 2 months. They gained improvement of flexion range of motion between 60° and 120° with a mean of 86.3°. Loss of final range of motion compared with the normal side was between 5° and 35° with a mean of 10°. No patient had limitation of activities or pain. Six cases had excellent and two cases had good Dillon functional score. All patients had lateral condyle prominent with different severities. There was one mild avascular necrosis and one fishtail deformity. Both of them had almost full range of motion. All patients had early physeal closure, except one, who had only 1 year follow-up. There was no case of progressive valgus deformity. Children with neglected fracture of LHC would benefit from anatomical reduction and internal fixation through a proper exposure and if indicated combined with multiple 'V' lengthening of common extensor muscle aponeurosis. This is a level IV study.

  16. Techniques for Source Zone and Plume Characterization of Tetrachloroethene in Fractured Limestone Aquifers

    DEFF Research Database (Denmark)

    Fjordbøge, Annika Sidelmann; Mosthaf, Klaus; Janniche, Gry S.

    Characterization of chlorinated solvents in fractured limestone aquifers is essential for proper development of site specific conceptual models and subsequent risk assessment and remediation. High resolution characterization is challenged by the difficulties involved in collection of intact core...... an improved conceptual understanding of contaminant transport. At both sites limestone cores were collected with significant core losses. The discrete quantification of chlorinated solvents in the retrieved limestone cores was compared to different FLUTe technologies at the DNAPL site and passive and active...... distribution compared to the data obtained by quantification of chlorinated solvents in the limestone cores....

  17. Integrity evaluation of power plant components by fracture mechanics and related techniques

    International Nuclear Information System (INIS)

    Mukherjee, B.; Vanderglas, M.L.; Davies, P.H.

    1982-01-01

    Power plant components can be subject to unexpected failures with serious consequences, unless careful attention is paid to minute crack defects and their possible growth. The Linear Elastic Fracture Mechanics approach to structural integrity evaluation, as it appears in the ASME Code, is discussed. Projects related to material data generation and the development of structural analysis methods to make the above method usable are described. Several integrity-related questions outside the scope of the Code guidelines are documented, concluding with comments on possible future developments

  18. Principle for the Realization of Dual-Orthogonal Linearly Polarized Antennas for UWB Technique

    Directory of Open Access Journals (Sweden)

    Grzegorz Adamiuk

    2011-01-01

    The presented method introduces a superior possibility of an extension of typical UWB technique to fully polarized systems, which improves significantly performance in, for example, UWB-MIMO or UWB-Radar.

  19. Complications and fixation techniques of trochanteric fractures with the TARGON(®) PF.

    Science.gov (United States)

    Takigawa, Naohide; Moriuchi, Hiromitsu; Abe, Muneki; Yasui, Kenji; Eshiro, Hisako; Kinoshita, Mitsuo

    2014-01-01

    The purpose of this study was to analyse clinical results of elderly patients with trochanteric fractures that were treated with use of TARGON(®) PF nail. Overall, 494 patients (113 males) were available for this study. On the basis of Jensen classification, there were 76 cases in type I, 164 cases in type II, 70 in type III, 129 in type IV and 55 in type V. (1) Sliding amount of lag screw in relation to the Jensen classification, (2) sliding amount of lag screw according to the Ikuta's classification that categorises the reduction in lateral view in three, Subtype A, Subtype N and Subtype P, (3) sliding amount of lag screw in correlation between Jensen classification and Ikuta's classification and (4) postoperative complications (9 cases; 1.7%) were assessed. Cut-out and back-out cases were seen in 6 cases (1.1%), and these severe complications were evaluated in details. In correlation between Jensen classification and Ikuta's classification, the excessive sliding of lag screw was prominent with the Subtype P, which was preoperatively in Jensen type III or V. Cut-out or back-out cases were caused either from (1) Subtype P that were preoperatively Jensen types III or V, or from (2) the fracture where there was bony defect anteriorly. Therefore, special care must be taken for these types. Copyright © 2013 Elsevier Ltd. All rights reserved.

  20. Approximate techniques for predicting size effects on cleavage fracture toughness (Jc)

    International Nuclear Information System (INIS)

    Kirk, M.T.; Dodds, R.H. Jr.

    1993-07-01

    This investigation examines the ability of an elastic T-stress analysis coupled with modified boundary layer (MBL) solution to predict stresses ahead of a crack tip in a variety of planar geometries. The approximate stresses are used as input to estimate the effective driving force for cleavage fracture (J 0 ) using the micromechanically based approach introduced by Dodds and Anderson. Finite element analyses for a wide variety of planar cracked geometries are conducted which have elastic biaxiality parameters (β) ranging from -0.99 (very low constraint) to +2.96 (very high constraint). The magnitude and sign of β indicate the rate at which crack-tip constraint changes with increasing applied load. All results pertain to a moderately strain hardening material (strain hardening exponent (η) of 10). These analyses suggest that β is an effective indicator of both the accuracy of T-MBL estimates of J 0 and of applicability limits on evolving fracture analysis methodologies (i.e. T-MBL, J-Q, and J/J 0 ). Specifically, when 1β1>0.4 these analyses show that the T-MBL approximation of J 0 is accurate to within 20% of a detailed finite-element analysis. As ''structural type'' configurations, i.e. shallow cracks in tension, generally have 1β1>0.4, it appears that only an elastic analysis may be needed to determine reasonably accurate J 0 values for structural conditions

  1. Remediation techniques for heavy metal-contaminated soils: Principles and applicability.

    Science.gov (United States)

    Liu, Lianwen; Li, Wei; Song, Weiping; Guo, Mingxin

    2018-08-15

    Globally there are over 20millionha of land contaminated by the heavy metal(loid)s As, Cd, Cr, Hg, Pb, Co, Cu, Ni, Zn, and Se, with the present soil concentrations higher than the geo-baseline or regulatory levels. In-situ and ex-situ remediation techniques have been developed to rectify the heavy metal-contaminated sites, including surface capping, encapsulation, landfilling, soil flushing, soil washing, electrokinetic extraction, stabilization, solidification, vitrification, phytoremediation, and bioremediation. These remediation techniques employ containment, extraction/removal, and immobilization mechanisms to reduce the contamination effects through physical, chemical, biological, electrical, and thermal remedy processes. These techniques demonstrate specific advantages, disadvantages, and applicability. In general, in-situ soil remediation is more cost-effective than ex-situ treatment, and contaminant removal/extraction is more favorable than immobilization and containment. Among the available soil remediation techniques, electrokinetic extraction, chemical stabilization, and phytoremediation are at the development stage, while the others have been practiced at full, field scales. Comprehensive assessment indicates that chemical stabilization serves as a temporary soil remediation technique, phytoremediation needs improvement in efficiency, surface capping and landfilling are applicable to small, serious-contamination sites, while solidification and vitrification are the last remediation option. The cost and duration of soil remediation are technique-dependent and site-specific, up to $500ton -1 soil (or $1500m -3 soil or $100m -2 land) and 15years. Treatability studies are crucial to selecting feasible techniques for a soil remediation project, with considerations of the type and degree of contamination, remediation goals, site characteristics, cost effectiveness, implementation time, and public acceptability. Copyright © 2018 Elsevier B.V. All rights

  2. [Management of spinal metastasis by minimal invasive surgery technique: Surgical principles, indications: A literature review].

    Science.gov (United States)

    Toquart, A; Graillon, T; Mansouri, N; Adetchessi, T; Blondel, B; Fuentes, S

    2016-06-01

    Spinal metastasis are getting more frequent. This raises the question of pain and neurological complications, which worsen the functional and survival prognosis of this oncological population patients. The surgical treatment must be the most complete as possible: to decompress and stabilize without delaying the management of the oncological disease. Minimal invasive surgery techniques are by definition, less harmful on musculocutaneous plan than opened ones, with a comparable efficiency demonstrated in degenerative and traumatic surgery. So they seem to be applicable and appropriate to this patient population. We detailed different minimal invasive techniques proposed in the management of spinal metastasis. For this, we used our experience developed in degenerative and traumatic pathologies, and we also referred to many authors, establishing a literature review thanks to Pubmed, Embase. Thirty eight articles were selected and allowed us to describe different techniques: percutaneous methods such as vertebro-/kyphoplasty and osteosynthesis, as well as mini-opened surgery, through a posterior or anterior way. We propose a surgical approach using these minimal invasive techniques, first according to the predominant symptom (pain or neurologic failure), then characteristics of the lesions (number, topography, type…) and the deformity degree. Whatever the technique, the main goal is to stabilize and decompress, in order to maintain a good quality of life for these fragile patients, without delaying the medical management of the oncological disease. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  3. Acoustic emission technique for characterisation of deformation, fatigue, fracture and phase transformation and for leak detection with high sensitivity- our experiences

    International Nuclear Information System (INIS)

    Jayakumar, T.; Mukhopadhyay, C.K.; Baldev Raj

    1996-01-01

    Acoustic emission technique has been used for studying tensile deformation, fracture behaviour, detection and assessment of fatigue crack growth and α-martensite phase transformation in austenitic alloys. A methodology for amplification of weak acoustic emission signals has been established. Acoustic emission technique with advanced spectral analysis has enabled detection with high sensitivity of minute leaks in noisy environments. (author)

  4. Report on alternative techniques to hydraulic fracturing for the exploration and exploitation of non conventional hydrocarbons - National Assembly No. 1581 / Senate No. 174

    International Nuclear Information System (INIS)

    LENOIR, Jean-Claude; BATAILLE, Christian

    2013-01-01

    Based on several hearings, and on missions in the USA and in Poland, this report addresses the issue of alternative techniques to hydraulic fracturing which appeared to be more advanced than hearings performed for a preliminary report had suggested. A first part outlines the necessity of fracturing the rock, and presents several possible modalities, proposes a detailed overview of alternative techniques to hydraulic fracturing used in the USA and in Poland. The second part outlines that coal gas is already an exploitable resource without rock fracturing; it discusses the possible perspectives thus associated for the old French coal-mining sites, outlines that this resource can be exploited without requiring hydraulic fracturing, and comments the first assessments. The third part addresses the possible management of risks associated with hydraulic fracturing: risks vary from one region to the other and therefore require further studies; the non-conventional hydrocarbon issue is addressed in different ways in the USA; the use of this technique must be controlled by public authorities. The next part outlines the need of an assessment of national resources before any assessment of the economic impact. The last part formulates several proposals for the future

  5. Improved techniques for outgoing wave variational principle calculations of converged state-to-state transition probabilities for chemical reactions

    Science.gov (United States)

    Mielke, Steven L.; Truhlar, Donald G.; Schwenke, David W.

    1991-01-01

    Improved techniques and well-optimized basis sets are presented for application of the outgoing wave variational principle to calculate converged quantum mechanical reaction probabilities. They are illustrated with calculations for the reactions D + H2 yields HD + H with total angular momentum J = 3 and F + H2 yields HF + H with J = 0 and 3. The optimization involves the choice of distortion potential, the grid for calculating half-integrated Green's functions, the placement, width, and number of primitive distributed Gaussians, and the computationally most efficient partition between dynamically adapted and primitive basis functions. Benchmark calculations with 224-1064 channels are presented.

  6. Musculoskeletal wide detector CT: Principles, techniques and applications in clinical practice and research

    International Nuclear Information System (INIS)

    Gondim Teixeira, Pedro Augusto; Gervaise, Alban; Louis, Matthias; Lecocq, Sophie; Raymond, Ariane; Aptel, Sabine; Blum, Alain

    2015-01-01

    Highlights: • Wide area-detector CT availability is growing steadily. • Advanced techniques such as Dynamic CT, Perfusion CT and dual energy can be used in clinical practice. • Optimal acquisition protocol is needed to increase diagnostic performance and limit dose exposure. • Guidelines for data acquisition and interpretation may increase diagnostic performance and reproducibility. - Abstract: A progressive increase in the detector width in CT scanners has meant that advanced techniques such as dynamic, perfusion and dual-energy CT are now at the radiologist's disposal. Although these techniques may be important for the diagnosis of various musculoskeletal diseases, data acquisition and interpretation can be challenging. This article offers a practical guide for the use of these tools including acquisition protocol, post-processing options and data interpretation based on 7 years of clinical experience in a tertiary university hospital

  7. Toughness-Dominated Regime of Hydraulic Fracturing in Cohesionless Materials

    Science.gov (United States)

    Germanovich, L. N.; Hurt, R. S.; Ayoub, J.; Norman, W. D.

    2011-12-01

    This work examines the mechanisms of hydraulic fracturing in cohesionless particulate materials with geotechnical, geological, and petroleum applications. For this purpose, experimental techniques have been developed, and used to quantify the initiation and propagation of hydraulic fractures in saturated particulate materials. The fracturing liquid is injected into particulate materials, which are practically cohesionless. The liquid flow is localized in thin self-propagating crack-like conduits. By analogy we call them 'cracks' or 'hydraulic fractures.' When a fracture propagates in a solid, new surfaces are created by breaking material bonds. Consequently, the material is in tension at the fracture tip. Because the particulate material is already 'fractured,' no new surface is created and no fracturing process per se is involved. Therefore, the conventional fracture mechanics principles cannot be directly applied. Based on the laboratory observations, performed on three particulate materials (Georgia Red Clay, silica flour, and fine sand, and their mixtures), this work offers physical concepts to explain the observed phenomena. The goal is to determine the controlling parameters of fracture behavior and to quantify their effects. An important conclusion of our work is that all parts of the cohesionless particulate material (including the tip zone of hydraulic fracture) are likely to be in compression. The compressive stress state is an important characteristic of hydraulic fracturing in particulate materials with low, or no, cohesion (such as were used in our experiments). At present, two kinematic mechanisms of fracture propagation, consistent with the compressive stress regime, can be offered. The first mechanism is based on shear bands propagating ahead of the tip of an open fracture. The second is based on the tensile strain ahead of the fracture tip and reduction of the effective stresses to zero within the leak-off zone. Scaling indicates that in our

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

    International Nuclear Information System (INIS)

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

    2005-01-01

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

  9. Gravity Reduction View: A Radiographic Technique for the Evaluation and Management of Weber B Fibula Fractures

    Directory of Open Access Journals (Sweden)

    Lauren Ehrlichman

    2017-03-01

    Full Text Available Background: While various radiographic parameters and application of manual/gravity stress have been proposed to elucidate instability for Weber B fibula fractures, the prognostic capability of these modalities remains unclear. Determination of anatomic positioning of the mortise is paramount. We propose a novel view, the Gravity Reduction View (GRV, which helps elucidate non-anatomic positioning and reducibility of the mortise.Methods: The patient is positioned lateral decubitus with the injured leg elevated on a holder with the fibula directed superiorly. The x-ray cassette is placed posterior to the heel, with the beam angled at 15˚ of internal rotation to obtain a mortise view. Our proposed treatment algorithm is based upon the measurement of the medial clear space (MCS on the GRV versus the static mortise view (and in comparison to the superior clear space (SCS and is based on reducibility of the MCS. A retrospective review of patients evaluated utilizing the GRV was performed.Results: 26 patients with Weber B fibula fractures were managed according to this treatment algorithm. Mean age was 50.57 years old (range: range:18-81, SD=19. 17 patients underwent operative treatment and 9 patients were initially treated nonoperatively. 2 patients demonstrated late displacement and were treated surgically. Using this algorithm, at a mean follow-up of 26 weeks, all patients had a final MCS that was less than the SCS (final mean MCS 2.86 mm vs. mean SCS of 3.32 indicating effectiveness of the treatment algorithm.Conclusion: The GRV is a novel radiographic view in which deltoid competency, reducibility and initial positioning of the mortise are assessed by comparing a static mortise view with the appearance of the mortise on the GRV. We have developed a treatment algorithm based on the GRV and have found it to be useful in guiding treatment and successful at achieving anatomic mortise alignment.

  10. Using Mitrofanoff's principle and Monti's technique as a surgical option for bladder augmentation with a continent stoma: a case report

    Directory of Open Access Journals (Sweden)

    Martins Antonio CP

    2011-02-01

    Full Text Available Abstract Introduction Hydronephrosis, reflux and renal failure are serious complications that occur in patients with neurogenic bladder associated with myelomeningocele. When the bladder compliance is lost, it is imperative to carry out surgery aimed at reducing bladder storage pressure. An ileocystoplasty, and for patients not suitable for intermittent catheterization, using the Mitrofanoff principle to form a continent stoma and the subsequent closure of the bladder neck, can be used. We report here, for the first time to the best of our knowledge, an association between two previously described techniques (the Mitrofanoff principle and the technique of Monti, that can solve the problem of a short appendix in obese patients. Case presentation A 33-year-old male Caucasian patient with myelomeningocele and neurogenic bladder developed low bladder compliance (4.0 mL/cm H2O while still maintaining normal renal function. A bladder augmentation (ileocystoplasty with continent derivation principle (Mitrofanoff was performed. During surgery, we found that the patient's appendix was too short and was insufficient to reach the skin. We decided to make an association between the Mitrofanoff conduit and the ileal technique of Monti, through which we performed an anastomosis of the distal stump of the appendix to the bladder (with an antireflux valve. Later, the proximal stump of the appendix was anastomosed to an ileal segment of 2.0 cm that was open longitudinally and reconfigured transversally (Monti technique, modeled by a 12-Fr urethral catheter, and finally, the distal stump was sutured at the patient's navel. After the procedure, a suprapubic cystostomy (22 Fr and a Foley catheter (10 Fr through the continent conduit were left in place. The patient had recovered well and was discharged on the tenth day after surgery. He remained with the Foley catheter (through the conduit for 21 days and cystostomy for 30 days. Six months after surgery he was

  11. Principles for new optical techniques in medical diagnostics for mHealth applications

    Science.gov (United States)

    Balsam, Joshua Michael

    Medical diagnostics is a critical element of effective medical treatment. However, many modern and emerging diagnostic technologies are not affordable or compatible with the needs and conditions found in low-income and middle-income countries and regions. Resource-poor areas require low-cost, robust, easy-to-use, and portable diagnostics devices compatible with telemedicine (i.e. mHealth) that can be adapted to meet diverse medical needs. Many suitable devices will need to be based on optical technologies, which are used for many types of biological analyses. This dissertation describes the fabrication and detection principles for several low-cost optical technologies for mHealth applications including: (1) a webcam based multi-wavelength fluorescence plate reader, (2) a lens-free optical detector used for the detection of Botulinum A neurotoxin activity, (3) a low cost micro-array reader that allows the performance of typical fluorescence based assays demonstrated for the detection of the toxin staphylococcal enterotoxin (SEB), and (4) a wide-field flow cytometer for high throughput detection of fluorescently labeled rare cells. This dissertation discusses how these technologies can be harnessed using readily available consumer electronics components such as webcams, cell phones, CCD cameras, LEDs, and laser diodes. There are challenges in developing devices with sufficient sensitivity and specificity, and approaches are presented to overcoming these challenges to create optical detectors that can serve as low cost medical diagnostics in resource-poor settings for mHealth.

  12. Using Electromagnetic Induction Technique to Detect Hydropedological Dynamics: Principles and Applications

    Science.gov (United States)

    Zhu, Qing; Liao, Kaihua; Doolittle, James; Lin, Henry

    2014-05-01

    Hydropedological dynamics including soil moisture variation, subsurface flow, and spatial distributions of different soil properties are important parameters in ecological, environmental, hydrological, and agricultural modeling and applications. However, technical gap exists in mapping these dynamics at intermediate spatial scale (e.g., farm and catchment scales). At intermediate scales, in-situ monitoring provides detailed data, but is restricted in number and spatial coverage; while remote sensing provides more acceptable spatial coverage, but has comparatively low spatial resolution, limited observation depths, and is greatly influenced by the surface condition and climate. As a non-invasive, fast, and convenient geophysical tool, electromagnetic induction (EMI) measures soil apparent electrical conductivity (ECa) and has great potential to bridge this technical gap. In this presentation, principles of different EMI meters are briefly introduced. Then, case studies of using repeated EMI to detect spatial distributions of subsurface convergent flow, soil moisture dynamics, soil types and their transition zones, and different soil properties are presented. The suitability, effectiveness, and accuracy of EMI are evaluated for mapping different hydropedological dynamics. Lastly, contributions of different hydropedological and terrain properties on soil ECa are quantified under different wetness conditions, seasons, and land use types using Classification and Regression Tree model. Trend removal and residual analysis are then used for further mining of EMI survey data. Based on these analyses, proper EMI survey designs and data processing are proposed.

  13. Principles and characteristics of surface radon and helium techniques used in uranium exploration

    International Nuclear Information System (INIS)

    Pacer, J.C.; Czarnecki, R.F.

    1980-09-01

    Studies were carried out to determine the nature of some of the surface radon and helium techniques used for uranium exploration. By performing radon and helium measurements at three sites with differing geology and accessibility, we were able to examine the constraints on the features determined. The sites are the Red Desert in south central Wyoming, Copper Mountain in central Wyoming, and Spokane Mountain in eastern Washington. The radon techniques employed were: zinc sulfide detectors, an ionization chamber, alpha track detectors, thermoluminescence detectors, charcoal canisters, and the partial extraction of lead-210 from soil samples. Helium was measured in soil-gas samples, soil gas from collectors, and soil samples. The ratio helium-4/argon-36 was measured in soil gas

  14. Principles and techniques of radiation hardening. Volume 2. Transient radiation effects in electronics (TREE)

    International Nuclear Information System (INIS)

    Rudie, N.J.

    1976-01-01

    The three-volume book is intended to serve as a review of the effects of thermonuclear explosion induced radiation (x-rays, gamma rays, and beta particles) and the resulting electromagnetic pulse (EMP). Volume 2 deals with the following topics: radiation effects on quartz crystals, tantalum capacitors, bipolar semiconductor devices and integrated circuits, field effect transistors, and miscellaneous electronic devices; hardening electronic systems to photon and neutron radiation; nuclear radiation source and/or effects simulation techniques; and radiation dosimetry

  15. A new mini-invasive technique in treating pediatric diaphyseal forearm fractures by bioabsorbable elastic stable intramedullary nailing: a preliminary technical report.

    Science.gov (United States)

    Sinikumpu, J-J; Keränen, J; Haltia, A-M; Serlo, W; Merikanto, J

    2013-01-01

    Operative treatment is often indicated in unstable pediatric diaphyseal forearm fractures. Recently minimally invasive reduction and elastic stable intramedullary nailing have been of increasing interest, instead of open reduction and internal fixation with plates. There are several disadvantages of metallic intramedullary implants, such as soft-tissue irritation and a risk of disturbing later imaging. Thus, they are generally removed in later operations. We aimed to develop a new technique to stabilize pediatric forearm fractures by the bioabsorbable intramedullary nailing. We developed a new, two-stage mini-invasive surgical technique to stabilize the unstable diaphyseal fractures in children. The procedure is bioabsorbable elastic stable intramedullary nailing. Ultra-high-strength bioabsorbable intramedullary nails of poly(lactide-co-glycolide) were manufactured for our purpose. The material has been widely proven to be biocompatible and stable enough for fracture treatment as screws and pins. We have used the new technique in the unstable both-bone diaphyseal forearm fractures in children between the ages of 5 and 15 years. We report the technique and our clinical experience in the series of those three cases that have been followed up for at least 12 months. The present series has been randomized for the procedure instead for titanium elastic stable intramedullary nailing, and the series represents a part of ongoing randomized trial. The reported cases operated by the new technique referred good union in the fractured bones and acceptable alignment in the follow-up. Removal of the implants was not required. No troubles with the procedure or implant per se were noticed, indicating good feasibility. One high-energy refracture occurred half year after the primary trauma. Traditional titanium implants were used to control the refracture. We report our preliminary experience of a new surgical mini-invasive procedure to stabilize the unstable pediatric forearm shaft

  16. Evidence-based medicine: Mandible fractures.

    Science.gov (United States)

    Morrow, Brad T; Samson, Thomas D; Schubert, Warren; Mackay, Donald R

    2014-12-01

    After studying this article, the participant should be able to: 1. Describe the anatomy and subunits of the mandible. 2. Review the cause and epidemiology of mandible fractures. 3. Discuss the preoperative evaluation and diagnostic imaging. 4. Understand the principles and techniques of mandible fracture reduction and fixation. The management of mandibular fractures has undergone significant improvement because of advancements in plating technology, imaging, and instrumentation. As the techniques in management continue to evolve, it is imperative for the practicing physician to remain up-to-date with the growing body of scientific literature. The objective of this Maintenance of Certification article is to present a review of the literature so that the physician may make treatment recommendation based on the best evidence available. Pediatric fractures have been excluded from this article.

  17. Advanced network programming principles and techniques : network application programming with Java

    CERN Document Server

    Ciubotaru, Bogdan

    2013-01-01

    Answering the need for an accessible overview of the field, this text/reference presents a manageable introduction to both the theoretical and practical aspects of computer networks and network programming. Clearly structured and easy to follow, the book describes cutting-edge developments in network architectures, communication protocols, and programming techniques and models, supported by code examples for hands-on practice with creating network-based applications. Features: presents detailed coverage of network architectures; gently introduces the reader to the basic ideas underpinning comp

  18. Insights to Superconducting Radio-Frequency Cavity Processing from First Principles Calculations and Spectroscopic Techniques

    Science.gov (United States)

    Ford, Denise Christine

    Insights to the fundamental processes that occur during the manufacturing of niobium superconducting radio-frequency (SRF) cavities are provided via analyses of density functional theory calculations and Raman, infrared, and nuclear magnetic resonance (NMR) spectra. I show that during electropolishing fluorine is bound and released by the reaction of the acid components in the solution: HF + H2SO4 HFSO3 + H2O. This result implies that new recipes can possibly be developed on the principle of controlled release of fluorine by a chemical reaction. I also show that NMR or Raman spectroscopy can be used to monitor the free fluorine when polishing with the standard electropolishing recipe. Density functional theory was applied to calculate the properties of common processing impurities---hydrogen, oxygen, nitrogen, and carbon---in the niobium. These impurities lower the superconducting transition temperature of niobium, and hydride precipitates are at best weakly superconducting. I modeled several of the niobium hydride phases relevant to SRF cavities, and explain the phase changes in the niobium hydrogen system based on the charge transfer between niobium and hydrogen and the strain field inside of the niobium. I also present evidence for a niobium lattice vacancy serving as a nucleation center for hydride phase formation. In considering the other chemical impurities in niobium, I show that the absorption of oxygen into a niobium lattice vacancy is preferred over the absorption of hydrogen, which indicates that oxygen can block these phase nucleation centers. I also show that dissolved oxygen atoms can trap dissolved hydrogen atoms to prevent niobium hydride phase formation. Nitrogen and carbon were studied in less depth, but behaved similarly to oxygen. Based on these results and a literature survey, I propose a mechanism for the success of the low-temperature anneal applied to niobium SRF cavities. Finally, I present the beginning of a model to describe magnetic

  19. Insights to Superconducting Radio-Frequency Cavity Processing from First Principles Calculations and Spectroscopic Techniques

    Energy Technology Data Exchange (ETDEWEB)

    Ford, Denise Christine [Northwestern Univ., Evanston, IL (United States)

    2013-03-01

    Insights to the fundamental processes that occur during the manufacturing of niobium superconducting radio-frequency (SRF) cavities are provided via analyses of density functional theory calculations and Raman, infrared, and nuclear magnetic resonance (NMR) spectra. I show that during electropolishing fluorine is bound and released by the reaction of the acid components in the solution: HF + H2SO4 <-> HFSO3 + H2O. This result implies that new recipes can possibly be developed on the principle of controlled release of fluorine by a chemical reaction. I also show that NMR or Raman spectroscopy can be used to monitor the free fluorine when polishing with the standard electropolishing recipe. Density functional theory was applied to calculate the properties of common processing impurities – hydrogen, oxygen, nitrogen, and carbon – in the niobium. These impurities lower the superconducting transition temperature of niobium, and hydride precipitates are at best weakly superconducting. I modeled several of the niobium hydride phases relevant to SRF cavities, and explain the phase changes in the niobium hydrogen system based on the charge transfer between niobium and hydrogen and the strain field inside of the niobium. I also present evidence for a niobium lattice vacancy serving as a nucleation center for hydride phase formation. In considering the other chemical impurities in niobium, I show that the absorption of oxygen into a niobium lattice vacancy is preferred over the absorption of hydrogen, which indicates that oxygen can block these phase nucleation centers. I also show that dissolved oxygen atoms can trap dissolved hydrogen atoms to prevent niobium hydride phase formation. Nitrogen and carbon were studied in less depth, but behaved similarly to oxygen. Based on these results and a literature survey, I propose a mechanism for the success of the low-temperature anneal applied to niobium SRF cavities. Finally, I

  20. Short frontal plane fractures involving the dorsoproximal articular surface of the proximal phalanx: Description of the injury and a technique for repair.

    Science.gov (United States)

    Wright, I M; Minshall, G J

    2018-01-01

    Chip fractures of the dorsoproximal articular margin of the proximal phalanx are common injuries in racehorses. Large fractures can extend distal to the joint capsule insertion and have been described as dorsal frontal fractures. To report the location and morphology of short frontal plane fractures involving the dorsoproximal articular surface of the proximal phalanx and describe a technique for repair under arthroscopic and radiographic guidance. Single centre retrospective case study. Case records of horses with frontal plane fractures restricted to the dorsoproximal epiphysis and metaphysis of the proximal phalanx referred to Newmarket Equine Hospital were retrieved, images reviewed and lesion morphology described. A technique for repair and the results obtained are reported. A total of 22 fractures in 21 horses commencing at the proximal articular surface exited the dorsal cortex of the proximal phalanx distal to the metacarpophalangeal/metatarsophalangeal joint capsule in 17 hind- and five forelimbs. All were in Thoroughbred racehorses. In 16 cases these were acute racing or training injuries; 20 fractures were medial, one lateral and one was midline. All were repaired with a single lag screw using arthroscopic and radiographically determined landmarks. A total of 16 horses raced after surgery with performance data similar to their preinjury levels. The study demonstrates substantial morphological similarities between individual lesions supporting a common pathophysiology, but does not identify precise causation. There are no cases managed differently that might permit assessment of the comparative efficacy of the treatment described. Short frontal plane fractures involving the dorsoproximal margin of the proximal phalanx that exit the bone distal to the metacarpophalangeal/metatarsophalangeal joint capsule have substantial morphological similarities, are amenable to minimally invasive repair and carry a good prognosis for return to training and racing.

  1. Influence of Ti addition on fracture behaviour of HSLA steel using TIG melting technique

    Science.gov (United States)

    Musa, M. H. A.; Maleque, M. A.; Ali, M. Y.

    2017-03-01

    The welding process is a critical stage in the production of structural parts and the microstructure and mechanical properties of the welded joints must be appropriate in order to guarantee the reliability and durability of the components. The fracture toughness behaviour, which accounts for the residual strength of the component in the presence of flaws or cracks, is one of the most important properties to be evaluated in terms of microstructure and mechanical properties. In this present study, the surface of high strength low alloy (HSLA) steel was surface modified with the preplacement of pure Titanium (Ti) powder using a tungsten inert gas (TIG) arc heat source, at 100 ampere current with a voltage 30 V and a constant traversing speed of 1.0 mm/s using Argon shielded gas. The effect of preplaced Ti powder on the strength and toughness properties of the modified HSLA steel surface was investigated. The results indicated that the tensile and yield strength of HSLA steel decreased by ∼12% and ∼14%, respectively. While the impact toughness increased by ∼33% and the ductility decreased by ∼50%. The fractography analysis results by scanning electron microscopy (SEM) were also presented in this paper.

  2. Handbook of thin film deposition processes and techniques principles, methods, equipment and applications

    CERN Document Server

    Seshan, Krishna

    2002-01-01

    New second edition of the popular book on deposition (first edition by Klaus Schruegraf) for engineers, technicians, and plant personnel in the semiconductor and related industries. This book traces the technology behind the spectacular growth in the silicon semiconductor industry and the continued trend in miniaturization over the last 20 years. This growth has been fueled in large part by improved thin film deposition techniques and the development of highly specialized equipment to enable this deposition. The book includes much cutting-edge material. Entirely new chapters on contamination and contamination control describe the basics and the issues-as feature sizes shrink to sub-micron dimensions, cleanliness and particle elimination has to keep pace. A new chapter on metrology explains the growth of sophisticated, automatic tools capable of measuring thickness and spacing of sub-micron dimensions. The book also covers PVD, laser and e-beam assisted deposition, MBE, and ion beam methods to bring together a...

  3. 40Ar-39Ar method for age estimation: principles, technique and application in orogenic regions

    International Nuclear Information System (INIS)

    Dalmejer, R.

    1984-01-01

    A variety of the K-Ar method for age estimation by 40 Ar/ 39 Ar recently developed is described. This method doesn't require direct analysis of potassium, its content is calculated as a function of 39 Ar, which is formed from 39 K under neutron activation. Errors resulted from interactions between potassium and calcium nuclei with neutrons are considered. The attention is paid to the technique of gradual heating, used in 40 Ar- 39 Ar method, and of obtaining age spectrum. Aplicabilities of isochronous diagram is discussed for the case of presence of excessive argon in a sample. Examples of 40 Ar- 39 Ar method application for dating events in orogenic regions are presented

  4. Allgöwer-Donati Versus Vertical Mattress Suture Technique Impact on Perfusion in Ankle Fracture Surgery: A Randomized Clinical Trial Using Intraoperative Angiography.

    Science.gov (United States)

    Shannon, Steven F; Houdek, Matthew T; Wyles, Cody C; Yuan, Brandon J; Cross, William W; Cass, Joseph R; Sems, Stephen A

    2017-02-01

    The purpose of this study was to evaluate which primary wound closure technique for ankle fractures affords the most robust perfusion as measured by laser-assisted indocyanine green angiography: Allgöwer-Donati or vertical mattress. Prospective, randomized. Level 1 Academic Trauma Center. Thirty patients undergoing open reduction internal fixation for ankle fractures were prospectively randomized to Allgöwer-Donati (n = 15) or vertical mattress (n = 15) closure. Demographics were similar for both cohorts with respect to age, sex, body mass index, surgical timing, and OTA/AO fracture classification. Skin perfusion (mean incision perfusion and mean perfusion impairment) was quantified in fluorescence units with laser-assisted indocyanine green angiography along the lateral incision as well as anterior and posterior to the incision at 30 separate locations. Minimum follow-up was 3 months with a mean follow-up 4.7 months. Allgöwer-Donati enabled superior perfusion compared with the vertical mattress suture technique. Mean incision perfusion for Allgöwer-Donati was 51 (SD = 13) and for vertical mattress was 28 (SD = 10, P ankle fractures. Theoretically, this may enhance soft tissue healing and decrease the risk of wound complications. Surgeons may take this into consideration when deciding closure techniques for ankle fractures. Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

  5. Estimation of fracture parameters in foam core materials using thermal techniques

    DEFF Research Database (Denmark)

    Dulieu-Barton, J. M.; Berggreen, Christian; Boyenval Langlois, C.

    2010-01-01

    is described. A mode I simulated crack in the form of a machined notch is used to establish the feasibility of the TSA approach to derive stress intensity factors for the foam material. The overall goal is to demonstrate that thermal techniques have the ability to provide deeper insight into the behaviour......The paper presents some initial work on establishing the stress state at a crack tip in PVC foam material using a non-contact infra-red technique known as thermoelastic stress analysis (TSA). A parametric study of the factors that may affect the thermoelastic response of the foam material...

  6. [Comparison of the grafting technique in treatment of thoracolumbar burst fractures:transpedicular intracorporeal versus posterolateral].

    Science.gov (United States)

    Li, Li; Shi, Ya-Min; Hou, Shu-Xun; Wang, Hua-Dong; Guo, Ji-Dong

    2011-02-01

    To retrospectively investigate the outcome of transpedicular intracorporeal grafting and posterolateral grafting in treatment of thoracolumbar burst fractures. Forty-six patients treated with transpedicular intracorporeal grafting from January 1999 to December 2009 and followed up for 19-119 months (average 67 ± 13 months) were reviewed retrospectively, and were compared with 18 patients who had underwent posterolateral fusion during the same period through radiographic analysis. Radiographic measurements included Cobb angle, vertebral wedge angle (VWA), ratio between anterior and posterior vertebral height (APHR), upper inter-vertebral angle, lower inter-vertebral angle on X-ray, CT and MRI. In transpedicular intracorporeal grafting group, the VWA was corrected from 27.2° ± 6.5° to 7.0° ± 3.0° and the APHR from (53.3 ± 11.8)% to (92.3 ± 2.4)%. In posterolateral fusion group, the VWA was corrected from 23.9° ± 4.4° to 8.8° ± 2.1° and the APHR from (60.7 ± 10.0)% to (88.5 ± 3.3)%. Transpedicular intracorporeal grafting group showed better postoperative correction results than posterolateral fusion group (P < 0.05), and had less loss of correction of Cobb angle, VWA and APHR at final follow-up (P < 0.05). The transpedicular intracorporeal grafting can improve injured vertebral body morphology recovery better than posterolateral bone grafting, but can not prevent the late loss of correction after implant removal.

  7. Prediction of posterior ligamentous complex injury in thoracolumbar fractures using non-MRI imaging techniques.

    Science.gov (United States)

    Rajasekaran, Shanmuganathan; Maheswaran, Anupama; Aiyer, Siddharth N; Kanna, Rishi; Dumpa, Srikanth Reddy; Shetty, Ajoy Prasad

    2016-06-01

    We aimed to formulate a radiological index based on plain radiographs and computer tomography (CT) to reliably detect posterior ligamentous complex (PLC) injury without need for MRI. Sixty out of 148 consecutive thoracolumbar fractures with doubtful PLC were assessed with MRI, CT and radiographs. PLC injury was assessed with the following radiological parameters: superior-inferior end plate angle (SIEA), vertebral body height (BH), local kyphosis (LK), inter-spinous distance (ISD) and inter-pedicular distance (IPD) and correlated with MRI findings of PLC injury. Statistical analysis was performed to identify the predictive values for the parameters to identify PLC damage. MRI identified PLC injury in 25/60 cases. The ISD and LK were found to be significant predictors of PLC injury. On radiographs the mean LK with PLC damage was 25.86° compared to 21.02° with an intact PLC (p = 0.006). The ISD difference was 6.70 mm in cases with PLC damage compared to 2.86 mm with an intact PLC (p = 0.011). In CT images, the mean LK with PLC damage was 22.96° compared to 18.44° with an intact PLC ( p = 0.019). The ISD difference was 3.10 mm with PLC damage compared to 1.62 mm without PLC damage (p = 0.005). On plain radiographs the presence of LK greater than 20 °(CI 64-95) and ISD difference greater than 2 mm (CI 70-97) can predict PLC injury. These guidelines may be utilised in the emergency room especially when the associated cost, availability and time delay in performing MRI are a concern.

  8. Evaluation of screen-film system quality: physical principles and measurement techniques

    International Nuclear Information System (INIS)

    Borasi, G.; Berardi, P.; Ferretti, P.P.; Piccagli, V.

    1990-01-01

    Comparative evaluation of radiographic filmscreen systems presents several problems from both the theoretical and the experimental point of view. From the theoretical point of view the main difficulties are related to the choice of the parameters best suited to express the 'overall quality' of a system. From the practical point of view the main problem is that to measure some basic quantities (resolution and noise) sophisticated and expensive instruments are required. This paper deals with both these problems. To express image quality we have assumed the signal-to-noise power ration: this index depends in a explicit way on contrast, resolution and noise of the system. The dependence on sensitivity is implicit and was derived using literature data. From a knowledge of the dependence of image quality on sensitivity it is possible to develop an 'overall quality' index which is considered to express the 'technological level' of the systems. In this work some basic phisical quantities (characteristic curve, sensitivity) were evaluated using standard instruments. To measure spatial resolution and noise an inexpensive, PC-based, TV-digitizer system was developed. As an example, both image and overall quality indices were evaluated on three mammographic systems which are typical of the three different 'phases' of the development of this technique

  9. MR-urography and CT-urography: principles, examination techniques, applications

    International Nuclear Information System (INIS)

    Nolte-Ernsting, C.; Adam, G.; Staatz, G.; Wildberger, J.

    2003-01-01

    MR-urography (MRU) and CT-urography (CTU) provide refined imaging of the upper urinary tract not achievable with conventional intravenous urography (IVU). The traditional MR-urographic technique utilizes unenhanced, heavily T 2 -weighted turbo spin-echo sequences for obtaining static fluid images of the urinary tract independent of the excretory renal function. T 2 -weighted MR-urograms have proved to be excellent in visualizing the dilated urinary tract, even in non-excreting kidneys. In contrast, T 1 -weighted MRU reflects the excretory renal function and displays the urine flow through the upper tract after renal excretion of an intravenously administered gadolinium chelate. The gadolinium-enhanced urine is visualized with fast T 1 -weighted 3D-gradient-echo sequences. The combination of gadolinium and low-dose furosemide (5-10 mg) is the key for achieving a uniform distribution of gadolinium in the collecting system and for avoiding susceptibility artifacts (T 2 *-effects) in the urine. T 1 -weighted excretory MRU provides impressive urograms of both non-dilated and obstructed collecting systems in patients with normal or moderately impaired renal function. Multislice-CT-urography (MS-CTU) is also an excretory urography like T 1 -weighted MRU. Furthermore, MS-CTU can be combined with low-dose furosemide for accelerated passage of excreted contrast material obviating the need for abdominal compression. CT-urography is limited by its radiation burden and the nephrotoxicity of radiographic contrast media. Combining MRU or MS-CTU with conventional MRI or CT offers several applications, e.g., diagnosis of intrinsic and extrinsic tumors. Meanwhile, MRU has replaced IVU in pediatric uroradiology and is also recommended for the assessment of renal transplants. MS-CTU may provide valuable information in chronic urolithiasis, especially if associated with a distorted urinary tract anatomy. Both MRU and MS-CTU will play an important role in modern uroradiology. (orig

  10. Stress fractures

    International Nuclear Information System (INIS)

    Berquist, T.H.; Cooper, K.L.; Pritchard, D.J.

    1985-01-01

    The diagnosis of a stress fracture should be considered in patients presented with pain after a change in activity, especially if the activity is strenuous and the pain is in the lower extremities. Since evidence of the stress fracture may not be apparent for weeks on routine radiographs, proper use of other imaging techniques will allow an earlier diagnosis. Prompt diagnosis is especially important in the femur, where displacement may occur

  11. Assessment of fracture risk

    International Nuclear Information System (INIS)

    Kanis, John A.; Johansson, Helena; Oden, Anders; McCloskey, Eugene V.

    2009-01-01

    Fractures are a common complication of osteoporosis. Although osteoporosis is defined by bone mineral density at the femoral neck, other sites and validated techniques can be used for fracture prediction. Several clinical risk factors contribute to fracture risk independently of BMD. These include age, prior fragility fracture, smoking, excess alcohol, family history of hip fracture, rheumatoid arthritis and the use of oral glucocorticoids. These risk factors in conjunction with BMD can be integrated to provide estimates of fracture probability using the FRAX tool. Fracture probability rather than BMD alone can be used to fashion strategies for the assessment and treatment of osteoporosis.

  12. Evaluation of the results from surgical treatment of fractures of the lateral extremity of the clavicle, using the double ligature technique

    Directory of Open Access Journals (Sweden)

    Alberto Naoki Miyazaki

    2015-04-01

    Full Text Available OBJECTIVE: To evaluate the incidence of consolidation in surgical treatment of fractures of the lateral extremity of the clavicle using the double subcoracoid ligature technique, with nonabsorbable No. 5 thread.METHODS: Between May 1993 and June 2013, the Shoulder and Elbow Group of our service surgically treated 116 patients (116 shoulders with fractures of the lateral extremity of the clavicle. Among these, we were able to reassess 65 cases. The surgical technique used consisted of double subcoracoid ligature with two nonabsorbable threads. In two patients classified as type III, we had to combine this technique with use of an interfragmentary screw for fixation of the intra-articular portion of the acromioclavicular joint.RESULTS: We achieved fracture consolidation in 90%. Fourteen cases (21% evolved with major complications: four cases of pseudarthrosis, five of adhesive capsulitis, two of delayed consolidation and three of loss of reduction. Two cases (3% evolved with minor complications of skin granuloma.CONCLUSION: The double ligature technique for fractures of the lateral extremity of the clavicle promotes the stabilization needed for consolidation to take place, without the need for synthesis using metal components. It avoids reoperation for the synthesis material to be removed. Moreover, it is a low-cost procedure with good reproducibility and preservation of the acromioclavicular joint.

  13. A Novel Minimally Invasive Reduction Technique by Balloon and Distractor for Intra-Articular Calcaneal Fractures: A Report of 2 Cases

    Directory of Open Access Journals (Sweden)

    M. Prod’homme

    2018-01-01

    Full Text Available Treatment of displaced intra-articular fractures of the calcaneus remains a challenge for the orthopaedic surgeon. Conservative therapy is known to produce functional impairment. Surgical approach is plagued by soft-tissue complications and insufficient fracture reduction. We describe a minimally invasive technique that will hopefully improve these issues. We want to present our first experience through two cases. The first was a 46-year-old man who presented with a Sanders type IIBC calcaneal fracture, and the second was a 86-year-old woman with a type IIIBC calcaneal fracture. We introduced 2 Schanz screws in the talus and the calcaneus. After distraction, we introduced an inflatable balloon inside the calcaneus. By inflating the balloon, the articular surface was reduced by lifting it up. Then bone cement was injected in order to maintain the reduction. Additional screw fixation was used in the young patient. Postoperative imaging showed good congruence of the subtalar joint without leakage of cement, for the two cases. After 2 months, the patients had no pain and were without soft-tissue complications. We advocate this technique to perform a minimally invasive reduction and fixation of intra-articular calcaneal fractures because it preserves soft-tissues and provides good clinical results with early weight-bearing.

  14. Novel management of distal tibial and fibular fractures with Acumed fibular nail and minimally invasive plating osteosynthesis technique: A case report.

    Science.gov (United States)

    Wang, Tie-Jun; Ju, Wei-Na; Qi, Bao-Chang

    2017-03-01

    Anatomical characteristics, such as subcutaneous position and minimal muscle cover, contribute to the complexity of fractures of the distal third of the tibia and fibula. Severe damage to soft tissue and instability ensure high risk of delayed bone union and wound complications such as nonunion, infection, and necrosis. This case report discusses management in a 54-year-old woman who sustained fractures of the distal third of the left tibia and fibula, with damage to overlying soft tissue (swelling and blisters). Plating is accepted as the first choice for this type of fracture as it ensures accurate reduction and rigid fixation, but it increases the risk of complications. Closed fracture of the distal third of the left tibia and fibula (AO: 43-A3). After the swelling was alleviated, the patient underwent closed reduction and fixation with an Acumed fibular nail and minimally invasive plating osteosynthesis (MIPO), ensuring a smaller incision and minimal soft-tissue dissection. At the 1-year follow-up, the patient had recovered well and had regained satisfactory function in the treated limb. The Kofoed score of the left ankle was 95. Based on the experience from this case, the operation can be undertaken safely when the swelling has been alleviated. The minimal invasive technique represents the best approach. Considering the merits and good outcome in this case, we recommend the Acumed fibular nail and MIPO technique for treatment of distal tibial and fibular fractures.

  15. Combined geophysical techniques for detailed groundwater flow investigation in tectonically deformed fractured rocks

    Directory of Open Access Journals (Sweden)

    John Alexopoulos

    2014-02-01

    Full Text Available In this paper we present a combination of several near surface geophysical investigation techniques with high resolution remote sensing image interpretations, in order to define the groundwater flow paths and whether they can be affected by future seismic events. A seasonal spring (Amvrakia located at the foot of Meteora pillars near the village of Kastraki (Greece was chosen as a test site. The Meteora conglomeratic formations crop out throughout the study area and are characterized by large discontinuities caused by post Miocene till present tectonic deformation [Ferriere et al. 2011, Royden and Papanikolaou 2011]. A network of groundwater pathways has been developed above the impermeable marls underlying the conglomeratic strata. Our research aims to define these water pathways in order to investigate and understand the exact mechanism of the spring by mapping the exposed discontinuity network with classic field mapping and remote sensing image interpretation and define their underground continuity with the contribution of near surface geophysical techniques. Five Very Low Frequency (VLF profiles were conducted with different directions around the spring aiming to detect possible conductive zones in the conglomeratic formations that the study area consists of. Moreover, two Electrical Resistivity Tomography (ERT sections of a total length of 140m were carried out parallel to the VLF profiles for cross-checking and verifying the geophysical information. Both techniques revealed important conductive zones (<200 Ohm m within the conglomerate strata, which we interpret as discontinuities filled with water supplying the spring, which are quite vulnerable to displacements as the hydraulic connections between them might be easily disturbed after a future seismic event.

  16. Solubilization of myofibrillar proteins in water or low ionic strength media: Classical techniques, basic principles, and novel functionalities.

    Science.gov (United States)

    Chen, Xing; Tume, Ron K; Xu, Xinglian; Zhou, Guanghong

    2017-10-13

    The qualitative characteristics of meat products are closely related to the functionality of muscle proteins. Myofibrillar proteins (MPs), comprising approximately 50% of total muscle proteins, are generally considered to be insoluble in solutions of low ionic strength ( 0.3 M) for solubilization. These soluble proteins are the ones which determine many functional properties of meat products, including emulsification and thermal gelation. In order to increase the utilization of meat and meat products, many studies have investigated the solubilization of MPs in water or low ionic strength media and determining their functionality. However, there still remains a lack of systematic information on the functional properties of MPs solubilized in this manner. Hence, this review will explore some typical techniques that have been used. The main procedures used for their solubilization, the fundamental principles and their functionalities in water (low ionic strength medium) are comprehensively discussed. In addition, advantages and disadvantages of each technique are summarized. Finally, future considerations are presented to facilitate progress in this new area and to enable water soluble muscle MPs to be utilized as novel meat ingredients in the food industry.

  17. A randomised prospective study of two different combined internal and external fixation techniques for distal tibia shaft fractures.

    Science.gov (United States)

    Sun, Liao-Jun; Yu, Xian-Bin; Dai, Cheng-Qian; Hu, Wei; Guo, Xiao-Shan; Chen, Hua

    2014-12-01

    External fixation combined with limited open reduction and internal fixation (EF + LORIF) is a well-accepted and effective method for distal tibia shaft fractures, but it was also related to complications. The objective of this study was to compare external fixation combined with closed reduction and internal fixation (EF + CRIF) with EF + LORIF in the treatment of distal tibia shaft fractures, and explore the benefits and defects of these two techniques. Fifty-six patients were randomised to operative stabilisation either by an external fixator combined with two closed titanium elastic nails or by external fixation combined with limited open reduction and internal fixation. Pre-operative variables included the patients’ age, sex, the affected side, cause of injury, Tscherne classification of soft tissue injury, fracture pattern, and time from injury to surgery. Peri-operative variables were the operating time and the radiation time. Postoperative variables were wound problems and other complications, union time, time of recovery to work, the functional American Orthopaedic Foot and Ankle surgery (AOFAS) score. There was no significant difference in the mean operating time (72.6 ± 11.5 vs. 78.5 ± 16.4 min, P = 0.125), the time to union (21.2 ± 11.0 vs. 22.5 ± 12.3 weeks, P = 0.678), the time of recovery to work (25.0 ± 14.5 vs. 26.4 ± 13.6 weeks, P = 0.711), pin track infection (3/28 vs. 4/28, P = 1.000), delayed union (2/28 vs. 3/28, P = 1.000), pain (38.3 ± 1.6 vs. 38.7 ± 1.5, P = 0.339), function (44.4 ± 6.0 vs. 45.0 ± 5.5, P = 0.698), and total AOFAS scores (91.5 ± 7.4 vs. 93.4 ± 6.8, P = 0.322) between the two groups. However, the mean radiation time was longer in the EF + CRIF group than in the EF + LORIF group (2.0 ± 1.2 vs. 0.3 ± 0.1 min, P alignment was obtained in 50 patients (22 in EF + CRIF vs. 28 in EF + LORIF, P = 0.023). Two cases with EF + CRIF had a 6 degrees of recurvatum deformity and four had 6–9 degrees of valgus deformity

  18. Fracture Mechanics

    International Nuclear Information System (INIS)

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

    1992-08-01

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

  19. Comparison of computer assisted surgery with conventional technique for treatment of abaxial distal phalanx fractures in horses: an in vitro study.

    Science.gov (United States)

    Rossol, Melanie; Gygax, Diego; Andritzky-Waas, Juliane; Zheng, Guoyan; Lischer, Christoph J; Zhang, Xuan; Auer, Joerg A

    2008-01-01

    To (1) evaluate and compare computer-assisted surgery (CAS) with conventional screw insertion (conventional osteosynthesis [COS]) for treatment of equine abaxial distal phalanx fractures; (2) compare planned screw position with actual postoperative position; and (3) determine preferred screw insertion direction. Experimental study. Cadaveric equine limbs (n=32). In 8 specimens each, a 4.5 mm cortex bone screw was inserted in lag fashion in dorsopalmar (plantar) direction using CAS or COS. In 2 other groups of 8, the screws were inserted in opposite direction. Precision of CAS was determined by comparison of planned and actual screw position. Preferred screw direction was also assessed for CAS and COS. In 4 of 6 direct comparisons, screw positioning was significantly better with CAS. Results of precision analysis for screw position were similar to studies published in human medicine. None of evaluated criteria identified a preferred direction for screw insertion. For abaxial fractures of the distal phalanx, superior precision in screw position is achieved with CAS technique compared with COS technique. Abaxial fractures of the distal phalanx lend themselves to computer-assisted implantation of 1 screw in a dorsopalmar (plantar) direction. Because of the complex anatomic relationships, and our results, we discourage use of COS technique for repair of this fracture type.

  20. SU-E-T-191: PITSTOP: Process Improvement Techniques, Software Tools, and Operating Principles for a Quality Initiative Discovery Framework.

    Science.gov (United States)

    Siochi, R

    2012-06-01

    To develop a quality initiative discovery framework using process improvement techniques, software tools and operating principles. Process deviations are entered into a radiotherapy incident reporting database. Supervisors use an in-house Event Analysis System (EASy) to discuss incidents with staff. Major incidents are analyzed with an in-house Fault Tree Analysis (FTA). A meta-Analysis is performed using association, text mining, key word clustering, and differential frequency analysis. A key operating principle encourages the creation of forcing functions via rapid application development. 504 events have been logged this past year. The results for the key word analysis indicate that the root cause for the top ranked key words was miscommunication. This was also the root cause found from association analysis, where 24% of the time that an event involved a physician it also involved a nurse. Differential frequency analysis revealed that sharp peaks at week 27 were followed by 3 major incidents, two of which were dose related. The peak was largely due to the front desk which caused distractions in other areas. The analysis led to many PI projects but there is still a major systematic issue with the use of forms. The solution we identified is to implement Smart Forms to perform error checking and interlocking. Our first initiative replaced our daily QA checklist with a form that uses custom validation routines, preventing therapists from proceeding with treatments until out of tolerance conditions are corrected. PITSTOP has increased the number of quality initiatives in our department, and we have discovered or confirmed common underlying causes of a variety of seemingly unrelated errors. It has motivated the replacement of all forms with smart forms. © 2012 American Association of Physicists in Medicine.

  1. A Study on the Fatigue-Fractured Surface of Normalized SS41 Steel and M.E.F. Dual Phase Steel by an X-ray Diffraction Technique

    International Nuclear Information System (INIS)

    Oh, Sae Wook; Park, Young Chul; Park, Soo Young; Kim, Deug Jin; Hue, Sun Chul

    1996-01-01

    This study verified the relationship between fracture mechanics parameters and X-ray parameters for normalized SS41 steel with homogeneous crystal structure and M.E.F. dual phase steel(martensite encapsulated islands of ferrite). The fatigue crack propagation test were carried out and X-ray diffraction technique was applied to fatigue fractured surface. The change in X-ray parameters(residual stress, half-value breadth) according to the depth of fatigue fractured surface were investigated. The depth of maximum plastic zone, W y , were determined on the basis of the distribution of the half-value breadth for normalized SS41 steel and that of the residual stress for M.E.F. dual phase steel. K max could be estimated by the measurement of W y

  2. Nr 1115 National Assembly, Nr 640 Senate - Stage report on alternate techniques to hydraulic fracturing for the exploration and exploitation of non conventional hydrocarbons

    International Nuclear Information System (INIS)

    Lenoir, Jean-Claude; Bataille, Christian

    2013-01-01

    While noticing that these resources are more supposed that demonstrated, this report first addresses the potential of non conventional hydrocarbon resources: definition, forms and assessment. It presents the status and locations of such resources in France, and discusses how uncertainties can be reduced as far as gas shale and hydrocarbons are concerned (exploration drillings seem necessary). The second part proposes an overview of the various extraction techniques: technologies without fracturing, and hydraulic fracturing (description, recall of previous uses in France, technique management). The third part presents alternate techniques as research topics to be explored: stimulation by another pressurized fluid than water, or by other physical processes (electric arc, thermal process). Proposals are stated. The document also comprised a report of meeting of the scientific committee, a list of heard persons, and a feasibility study

  3. A Study of Structural Stress Technique for Fracture Prediction of an Auto-Mobile Clutch Snap-Ring

    International Nuclear Information System (INIS)

    Kim, Ju Hee; Myeong, Man Sik; Oh, Chang Sik; Kim, Yun Jae

    2016-01-01

    The endurance reliability assessment of a highly complex mechanism is generally predicted by the fatigue life based on simple stress analysis. This study discusses various fatigue life assessment techniques for an automobile clutch snap ring. Finite element analyses were conducted to determine the structural stress on the snap ring. Structural stress that is insensitive in regards to the mesh size and type definition is presented in this study. The structural stress definition is consistent with elementary structural mechanics theory and provides an effective measure of a stress state that pertains to fatigue behavior of welded joints in the form of both membrane and bending components. Numerical procedures for both solid models and shell or plate element models are presented to demonstrate the mesh-size insensitivity when extracting the structural stress parameters. Conventional finite element models can be used with the structural stress calculations as a post-processing procedure. The two major implications from this research were: (a) structural stresses pertaining to fatigue behavior can be consistently calculated in a mesh-insensitive manner regardless of the types of finite element models; and (b) by comparing with the clutch snap-ring fatigue test data, we should predict the fatigue fractures of an automobile clutch snap ring using this method

  4. Comparative Evaluation of Marginal Adaptation and Fracture Strength of Different Ceramic Inlays Produced by CEREC Omnicam and Heat-Pressed Technique

    Directory of Open Access Journals (Sweden)

    F. D. Oz

    2018-01-01

    Full Text Available Objective. The aim of this in vitro study was to evaluate marginal adaptation and fracture strength of inlays produced by CEREC Omnicam using different types of blocs and heat-pressed technique. Methods: Seventy-five extracted human mandibular molars were divided randomly into 5 groups (n=15. 60 molars in four groups received MOD inlay preparations. Experimental groups were CO: Intact teeth, EC: IPS e.max CAD and CEREC, LU: Lava Ultimate and CEREC, EL: IPS Empress CAD and CEREC, EP: IPS Empress Esthetic ingots and heat-pressed technique. Marginal gap measurements were taken with a stereomicroscope. Restorations were cemented with Variolink N and stored in distilled water at 37°C for 24 hours. All samples were subjected to thermocycling. The fracture strength of specimens was determined at a 0.5 mm/min crosshead speed until fracture. Fracture modes were determined. Statistical analyses were performed using one-way analysis of variance for fracture strength data and Kruskal–Wallis for marginal gap data (p=0.05. Results. The mean marginal gap size of EC, LU, EL, and EP were 33.54 µm, 33.77 µm, 34.23 µm, and 85.34 µm, respectively. EP had statistically higher values than other groups. The fracture strength values were significantly higher in the intact teeth group (3959,00 ± 1279,79 N than those of restored groups EC (2408,00 ± 607,97 N, LU (2206,73 ± 675,16, EL (2573.27 ± 644,73 ve EP (2879,53 ± 897,30. Conclusion. Inlays fabricated using CEREC Omnicam demonstrated better marginal adaptation than inlays produced with heat-pressed technique, whereas fracture strength values of inlays fabricated with different type of blocks using CEREC Omnicam exhibited similarity to those fabricated with heat-pressed technique.

  5. Comparative Evaluation of Marginal Adaptation and Fracture Strength of Different Ceramic Inlays Produced by CEREC Omnicam and Heat-Pressed Technique.

    Science.gov (United States)

    Oz, F D; Bolay, S

    2018-01-01

    The aim of this in vitro study was to evaluate marginal adaptation and fracture strength of inlays produced by CEREC Omnicam using different types of blocs and heat-pressed technique. Methods: Seventy-five extracted human mandibular molars were divided randomly into 5 groups ( n =15). 60 molars in four groups received MOD inlay preparations. Experimental groups were CO: Intact teeth, EC: IPS e.max CAD and CEREC, LU: Lava Ultimate and CEREC, EL: IPS Empress CAD and CEREC, EP: IPS Empress Esthetic ingots and heat-pressed technique. Marginal gap measurements were taken with a stereomicroscope. Restorations were cemented with Variolink N and stored in distilled water at 37°C for 24 hours. All samples were subjected to thermocycling. The fracture strength of specimens was determined at a 0.5 mm/min crosshead speed until fracture. Fracture modes were determined. Statistical analyses were performed using one-way analysis of variance for fracture strength data and Kruskal-Wallis for marginal gap data ( p =0.05). The mean marginal gap size of EC, LU, EL, and EP were 33.54  µ m, 33.77  µ m, 34.23  µ m, and 85.34  µ m, respectively. EP had statistically higher values than other groups. The fracture strength values were significantly higher in the intact teeth group (3959,00 ± 1279,79 N) than those of restored groups EC (2408,00 ± 607,97 N), LU (2206,73 ± 675,16), EL (2573.27 ± 644,73) ve EP (2879,53 ± 897,30). Inlays fabricated using CEREC Omnicam demonstrated better marginal adaptation than inlays produced with heat-pressed technique, whereas fracture strength values of inlays fabricated with different type of blocks using CEREC Omnicam exhibited similarity to those fabricated with heat-pressed technique.

  6. Application of computer-aided three-dimensional skull model with rapid prototyping technique in repair of zygomatico-orbito-maxillary complex fracture.

    Science.gov (United States)

    Li, Wei Zhong; Zhang, Mei Chao; Li, Shao Ping; Zhang, Lei Tao; Huang, Yu

    2009-06-01

    With the advent of CAD/CAM and rapid prototyping (RP), a technical revolution in oral and maxillofacial trauma was promoted to benefit treatment, repair of maxillofacial fractures and reconstruction of maxillofacial defects. For a patient with zygomatico-facial collapse deformity resulting from a zygomatico-orbito-maxillary complex (ZOMC) fracture, CT scan data were processed by using Mimics 10.0 for three-dimensional (3D) reconstruction. The reduction design was aided by 3D virtual imaging and the 3D skull model was reproduced using the RP technique. In line with the design by Mimics, presurgery was performed on the 3D skull model and the semi-coronal incision was taken for reduction of ZOMC fracture, based on the outcome from the presurgery. Postoperative CT and images revealed significantly modified zygomatic collapse and zygomatic arch rise and well-modified facial symmetry. The CAD/CAM and RP technique is a relatively useful tool that can assist surgeons with reconstruction of the maxillofacial skeleton, especially in repairs of ZOMC fracture.

  7. Safety screw fixation technique in a case of coracoid base fracture with acromioclavicular dislocation and coracoid base cross-sectional size data from a computed axial tomography study.

    Science.gov (United States)

    Kawasaki, Yoshiteru; Hirano, Tetsuya; Miyatake, Katsutoshi; Fujii, Koji; Takeda, Yoshitsugu

    2014-07-01

    Coracoid base fracture accompanied by acromioclavicular joint dislocation with intact coracoclavicular ligaments is a rare injury. Generally, an open reduction with screw fixation is the first treatment choice, as it protects the important structures around the coracoid process. This report presents a new technique of screw fixation for coracoid base fracture and provides anatomic information on cross-sectional size of the coracoid base obtained by computed tomography (CT). An axial image of the coracoid base was visualized over the neck of the scapula, and a guidewire was inserted into this circle under fluoroscopic guidance. The wire was inserted easily into the neck of scapula across the coracoid base fracture with imaging in only 1 plane. In addition, 25 measurements of the coracoid base were made in 25 subjects on axial CT images. Average length of the long and short axes at the thinnest part of the coracoid base was 13.9 ± 2.0 mm (range 10.6-17.0) and 10.5 ± 2.2 mm (6.6-15.1), respectively. This new screw fixation technique and measurement data on the coracoid base may be beneficial for safety screw fixation of coracoid base fracture.

  8. Pediatric mandibular fractures.

    Science.gov (United States)

    Schweinfurth, J M; Koltai, P J

    1998-01-01

    Over the last 20 years, a revolution in the management of facial fractures has taken place. Refinements in biocompatible materials of great delicacy and strength along with advances in our understanding of biomechanics of the face, have rendered complex injuries consistently amenable to accurate 3-dimensional reconstruction. Furthermore, with the availability of education in the techniques of internal rigid fixation, these advanced techniques have become routine practice in adults. However, the suitability of rigid internal fixation for children remains controversial. There are many concerns about the effect of implanted hardware in the mandible of a growing child. In addition, some evidence suggests that the elevation of functional matrix off of bone may result in alterations in development. The goal is to restore the underlying bony architecture to its pre-injury position in a stable fashion, with a minimal of aesthetic and functional impairment. However, in children the treatment of bony injuries is most easily accomplished by techniques that may adversely effect craniofacial development. While it is not entirely possible to resolve this dilemma, there exists an extensive body of experimental and clinical information on the appropriate management of pediatric mandibular fractures which can be used to formulate a rational treatment plan for most cases. This paper presents an overview of the contemporary understanding and application of these treatment principles.

  9. Surgical treatment of mandibular condyle fractures using the retromandibular anterior transparotid approach and a triangular-positioned double miniplate osteosynthesis technique: A clinical and radiological evaluation of 124 fractures.

    Science.gov (United States)

    Dalla Torre, Daniel; Burtscher, Doris; Widmann, Gerlig; Pichler, Albina; Rasse, Michael; Puelacher, Wolfgang

    2015-07-01

    Different modalities have been described regarding the treatment of mandibular condyle fractures. The most advantageous and safest one is still a topic of discussion. The present analysis describes the combination of a retromandibular, transparotideal approach combined to a triangular-positioned double-miniplate osteosynthesis, with a special regard for the patients' long term outcomes. Clinical data of 102 patients with 124 condyle fractures treated with the mentioned surgical procedure were evaluated. Functional parameters such as the maximal interincisal distance, deviations/deflections, facial nerve function, occlusion as well as complications regarding the parotid gland, osteosynthesis, and esthetics were evaluated 1 week, 2 weeks, 3 months, and 6 months postoperatively. The mean maximal interincisal distance ranged from 38 mm after 1 week to 45 mm after 6 months. Deviations/deflections were seen in 22.5% of the cases 1 week postoperatively and decreased to 2% at 6 months postoperatively. A temporary facial palsy was diagnosed in 3.9% during the first follow-up, whereas no impairment was recorded after 3 or 6 months. At the same time, no patient had occlusional disturbances or complications regarding the parotid gland or the osteosynthesis 6 months postoperatively. Direct fracture visualization and a stable three-dimensional fracture stabilization are the main advantages of the presented combination of a surgical approach and osteosynthesis technique. Additionally, the absence of long-term complications confirms the safety of the procedure. Therefore, it may be considered as a successful treatment option for mandibular condyle fractures. Copyright © 2015 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

  10. A Complex Facial Trauma Case with Multiple Mandibular Fractures and Dentoalveolar Injuries

    Directory of Open Access Journals (Sweden)

    Yeliz Guven

    2015-01-01

    Full Text Available The principles of management of mandibular fractures differ in children when compared to adults and depend on the specific age-related status of the growing mandible and the developing dentition. This paper presents a case report with a complex facial trauma affecting the mandibular body and condyle region and dentoalveolar complex. Clinical examination revealed soft tissue injuries, limited mouth opening, lateral deviation of the mandible, an avulsed incisor, a subluxated incisor, and a fractured crown. CBCT examination revealed a nondisplaced fracture and an oblique greenstick fracture of the mandibular body and unilateral fracture of the condyle. Closed reduction technique was chosen to manage fractures of the mandible. Favorable healing outcomes on multiple fractures of the mandible throughout the 6-year follow-up period proved the success of the conservative treatment. This case report is important since it presents a variety of pathological sequelae to trauma within one case.

  11. Knee arthrodesis with lengthening: experience of using Ilizarov techniques to salvage large asymmetric defects following infected peri-articular fractures.

    Science.gov (United States)

    Barwick, Thomas W; Montgomery, Richard J

    2013-08-01

    We present four patients with large bone defects due to infected internal fixation of knee condylar fractures. All were treated by debridement of bone and soft tissue and stabilisation with flap closure if required, followed by bone transport arthrodesis of the knee with simultaneous lengthening. Four patients (three male and one female), mean age 46.5 years (37-57 years), with posttraumatic osteomyelitis at the knee (three proximal tibia and one distal femur) were treated by debridement of infected tissue and removal of internal fixation. Substantial condylar bone defects resulted on the affected side of the knee joint (6-10 cm) with loss of the extensor mechanism in all tibial cases. Two patients required muscle flaps after debridement. All patients received intravenous antibiotics for at least 6 weeks. Bone transport with a circular frame was used to achieve an arthrodesis whilst simultaneously restoring a functional limb length. In three cases a 'peg in socket' docking technique was fashioned to assist stability and subsequent consolidation of the arthrodesis. Arthrodesis of the knee, free of recurrent infection, was successfully achieved in all cases. None has since required further surgery. Debridement to union took an average of 25 months (19-31 months). The median number of interventions undertaken was 9 (8-12). Two patients developed deep vein thrombosis (DVT), one complicated by PE, which delayed treatment. Two required surgical correction of pre-existent equinus contracture using frames. The median limb length discrepancy (LLD) at the end of treatment was 3 cm (3-4 cm). None has required subsequent amputation. Bone loss and infection both reduce the success rate of any arthrodesis. However, by optimising the host environment with eradication of infection by radical debridement, soft-tissue flaps when necessary and bone transport techniques to close the defect, one can achieve arthrodesis and salvage a useful limb. The residual LLD can result from not

  12. Student-centered and ability training-oriented curriculum reform in teaching Microcontroller Principles and Interface Techniques

    Science.gov (United States)

    Wang, Xiaoping; Cai, Peijun; Liu, Yuling; Wang, Liqiang; Liang, Yiyong

    2017-08-01

    Courses are an important way of cultivating talents in college education. Advanced training schemes and the course system are implemented through course teaching. Advanced teaching notions and methods also rely on course teaching. Therefore, the quality of course teaching is the fundamental guarantor for grooming talent. The teachers of the course "Microcontroller Principles and Interface Techniques" in the Optical Science and Engineering College of Zhejiang University insist on course teaching becoming student centered and ability-training-oriented. They pay attention to students'all-round development in terms of learning ability, practical ability, innovation ability, and exploring spirit. They actively carried out course reforms in four aspects, namely teaching, learning, evaluation, and experimentation. This paper mainly introduced these reforms. First, the teaching method was reformed by introducing case analysis and the notion of a flipped classroom to shift the course focus from the teacher to the students. Second, the learning method was reformed through the use of techniques such as peer learning and project design to promote students' sense of enquiry and learning initiative. Third, the evaluation method was reformed through the use of process assessment and diversity evaluation to encourage students to develop logical thinking and a down-to-earth manner. Fourth, the experimentation method was reformed by introducing hierarchical content, process management, and diversification of examination to change students'learning attitude from "dependence, passivity, and imitation" to "independence, active involvement, and creation."In general, the teaching method reform promoted reforms in learning, evaluation, and experimentation methods and further improved the style of study. These reforms improved teachers' teaching abilities and enabled course teaching to transform from being teacher centered to student centered. Years of exploration and practice results have

  13. Estimation of fracture toughness of Zr 2.5% Nb pressure tube of Pressurised Heavy Water Reactor using cyclic ball indentation technique

    Energy Technology Data Exchange (ETDEWEB)

    Chatterjee, S., E-mail: subrata@barc.gov.in; Panwar, Sanjay; Madhusoodanan, K.; Rama Rao, A.

    2016-08-15

    Highlights: • Measurement of fracture toughness of pressure tube is required for its fitness assessment. • Pressure tube removal from the core consumes large amount of radiation for laboratory test. • A remotely operable In situ Property Measurement System (IProMS) has been designed in house. • Conventional and IProMS tests conducted on pressure tube spool pieces having different mechanical properties. • Correlation has been established between the conventional and IProMS estimated fracture properties. - Abstract: In Pressurised Heavy Water Reactors (PHWRs) fuel bundles are located inside horizontal pressure tubes made up of Zr 2.5 wt% Nb alloy. Pressure tubes undergo degradation during its service life due to high pressure, high temperature and radiation environment. Measurement of mechanical properties of degraded pressure tubes is important for assessing their fitness for further operation. Presently as per safety guidelines imposed by the regulatory body, a few pre-decided pressure tubes are removed from the reactor core at regular intervals during the planned reactor shut down to carry out post irradiation examination (PIE) in a laboratory which consumes lots of man-rem and imposes economic penalties. Hence a system is indeed felt necessary which can carry out experimental trials for measurement of mechanical properties of pressure tubes under in situ conditions. The only way to accomplish this important objective is to develop a system based on an in situ measurement technique. In the field of in situ estimation of properties of materials, cyclic ball indentation is an emerging technique. Presently, commercial systems are available for doing an indentation test either on the outside surface of a component at site or on a test piece in a laboratory. However, these systems cannot be used inside a pressure tube for carrying out ball indentation trials under in situ conditions. Considering the importance of such measurements, an In situ Property

  14. Right trisectionectomy with principle en bloc portal vein resection for right-sided hilar cholangiocarcinoma: no-touch technique.

    Science.gov (United States)

    Machado, Marcel Autran; Makdissi, Fabio F; Surjan, Rodrigo C

    2012-04-01

    The most favorable long-term survival rate for hilar cholangiocarcinoma is achieved by a R0 resection. A surgical concept involving a no-touch technique, with extended right hepatic resections and principle en bloc portal vein resection was described by Neuhaus et al. According to Neuhaus et al., their technique may increase the chance of R0, because the right branch of the portal vein and hepatic artery is in close contact with the tumor and is frequently infiltrated. The left artery runs on the left margin of the hilum and often is free. The 5-year survival rate for their patients is 61% but 60-day mortality rate is 8%. Given the increased morbidity, some authors do not agree with routine resection of portal vein and may perform the resection of portal vein only on demand, after intraoperative assessment and confirmation of portal vein invasion. This video shows en bloc resection of extrahepatic bile ducts, portal vein bifurcation, and right hepatic artery, together with extended right trisectionectomy (removal of segments 1, 4, 5, 6, 7, and 8). A 75-year-old man with progressive jaundice due to right-sided hilar cholangiocarcinoma underwent percutaneous biliary drainage with metallic stents for palliation. The patient was referred for a second opinion. Serum bilirubin levels were normal, and CT scan showed a resectable tumor, but volumetry showed a small left liver remnant. Right portal vein embolization was then performed, and CT scan performed after 4 weeks showed adequate compensatory hypertrophy of the future liver remnant (segments 2 and 3). Surgical decision was to perform a right trisectionectomy with en bloc portal vein and bile duct resection using the no-touch technique. The operation began with hilar lymphadenectomy. The common bile duct is sectioned. Right hepatic artery is ligated. Left hepatic artery is encircled. Portal vein is dissected and encircled. Right liver is mobilized and detached from retrohepatic vena cava. Right and middle hepatic

  15. Some probabilistic aspects of fracture

    International Nuclear Information System (INIS)

    Thomas, J.M.

    1982-01-01

    Some probabilistic aspects of fracture in structural and mechanical components are examined. The principles of fracture mechanics, material quality and inspection uncertainty are formulated into a conceptual and analytical framework for prediction of failure probability. The role of probabilistic fracture mechanics in a more global context of risk and optimization of decisions is illustrated. An example, where Monte Carlo simulation was used to implement a probabilistic fracture mechanics analysis, is discussed. (orig.)

  16. Clinical Comparison of Extensile Lateral Approach and Sinus Tarsi Approach Combined with Medial Distraction Technique for Intra-Articular Calcaneal Fractures.

    Science.gov (United States)

    Zhou, Hai-Chao; Yu, Tao; Ren, Hao-Yang; Li, Bing; Chen, Kai; Zhao, You-Guang; Yang, Yun-Feng

    2017-02-01

    To study and compare the clinical outcomes of open reduction and internal fixation via extensile L-shape incision and limited open reduction via the sinus tarsi approach using the medial distraction technique for intra-articular calcaneal fractures. We performed a retrospective review of 65 intra-articular calcaneal fractures treated operatively between March 2012 and February 2015. Patients were divided into two groups: 28 were in the sinus tarsi approach group and 37 were in the extensile lateral approach group. All patients were asked to return for a research visit that included radiography and clinical evaluation. The postoperative function was evaluated using the ankle and hindfoot score of the American Orthopaedic Foot and Ankle Society (AOFAS) and the visual analogue scale (VAS). No significant difference was found in demographics between the two groups. The corrected value of the calcaneal varus angle between the two groups is statistically significant (P articular calcaneal fractures could reduce the incidence of wound complications effectively, and the medial distraction technique is helpful for correcting the calcaneus varus deformity. © 2017 Chinese Orthopaedic Association and John Wiley & Sons Australia, Ltd.

  17. A novel technique for preventing skin pressure sores using a rubber tube during surgical treatment of mandibular condyle fractures.

    Science.gov (United States)

    Kawase-Koga, Yoko; Mori, Yoshiyuki; Hoshi, Kazuhito; Takato, Tsuyoshi

    2013-11-01

    Craniofacial surgery occasionally results in sores and necrosis of the facial skin because of pressure from surgical instruments. During surgical treatment of mandibular condylar process fractures, the main mandibular fragment is routinely retracted downward using a wire to achieve a satisfactory anatomic reduction. This procedure may injure the facial skin. This potential complication is easily overlooked by medical staff, but it is easily preventable. We herein describe a method of using a rubber tube to avoid causing pressure sores of the facial skin during surgical treatment of mandibular condylar process fractures.

  18. Is Anesthesia Technique Associated With a Higher Risk of Mortality or Complications Within 90 Days of Surgery for Geriatric Patients With Hip Fractures?

    Science.gov (United States)

    Desai, Vimal; Chan, Priscilla H; Prentice, Heather A; Zohman, Gary L; Diekmann, Glenn R; Maletis, Gregory B; Fasig, Brian H; Diaz, Diana; Chung, Elena; Qiu, Chunyuan

    2018-06-01

    Postoperative mortality and complications after geriatric hip fracture surgery remain high despite efforts to improve perioperative care for these patients. One factor of particular interest is anesthetic technique, but prior studies on this are limited by sample selection, competing risks, and incomplete followup. (1) Among older patients undergoing surgery for hip fracture, does 90-day mortality differ depending on the type of anesthesia received? (2) Do 90-day emergency department returns and hospital readmissions differ based on anesthetic technique after geriatric hip fracture repairs? (3) Do 90-day Agency for Healthcare Research and Quality (AHRQ) outcomes differ according to anesthetic techniques used during hip fracture surgery? We conducted a retrospective study on geriatric patients (65 years or older) with hip fractures between 2009 and 2014 using the Kaiser Permanente Hip Fracture Registry. A total of 1995 (11%) of the surgically treated patients with hip fracture were excluded as a result of missing anesthesia information. The final study sample consisted of 16,695 patients. Of these, 2027 (12%) died and 98 (< 1%) terminated membership during followup, which were handled as competing events and censoring events, respectively. Ninety-day mortality, emergency department returns, hospital readmission, deep vein thrombosis (DVT) or pulmonary embolism (PE), myocardial infarction (MI), and pneumonia were evaluated using multivariable competing risk proportional subdistribution hazard regression according to type of anesthesia technique: general anesthesia, regional anesthesia, or conversion from regional to general. Of the 16,695 patients, 58% (N = 9629) received general anesthesia, 40% (N = 6597) received regional anesthesia, and 2.8% (N = 469) patients were converted from regional to general. Compared with regional anesthesia, patients treated with general anesthesia had a higher likelihood of overall 90-day mortality (hazard ratio [HR], 1.22; 95

  19. Development of a computer code 'CRACK' for elastic and elastoplastic fracture mechanics analysis of 2-D structures by finite element technique

    International Nuclear Information System (INIS)

    Dutta, B.K.; Kakodkar, A.; Maiti, S.K.

    1986-01-01

    The fracture mechanics analysis of nuclear components is required to ensure prevention of sudden failure due to dynamic loadings. The linear elastic analysis near to a crack tip shows presence of stress singularity at the crack tip. The simulation of this singularity in numerical methods enhance covergence capability. In finite element technique this can be achieved by placing mid nodes of 8 noded or 6 noded isoparametric elements, at one fourth ditance from crack tip. Present report details this characteristic of finite element, implementation of this element in a code 'CRACK', implementation of J-integral to compute stress intensity factor and solution of number of cases for elastic and elastoplastic fracture mechanics analysis. 6 refs., 6 figures. (author)

  20. Analysis of Dynamic Fracture Parameters in Functionally Graded Material Plates with Cracks by Graded Finite Element Method and Virtual Crack Closure Technique

    Directory of Open Access Journals (Sweden)

    Li Ming Zhou

    2016-01-01

    Full Text Available Based on the finite element software ABAQUS and graded element method, we developed a dummy node fracture element, wrote the user subroutines UMAT and UEL, and solved the energy release rate component of functionally graded material (FGM plates with cracks. An interface element tailored for the virtual crack closure technique (VCCT was applied. Fixed cracks and moving cracks under dynamic loads were simulated. The results were compared to other VCCT-based analyses. With the implementation of a crack speed function within the element, it can be easily expanded to the cases of varying crack velocities, without convergence difficulty for all cases. Neither singular element nor collapsed element was required. Therefore, due to its simplicity, the VCCT interface element is a potential tool for engineers to conduct dynamic fracture analysis in conjunction with commercial finite element analysis codes.

  1. Treament of Tibial Plateau Schatzker Type VI Fractures with the Ilizarov Technique Using Ring External Fixators Across the Knee: A Retrospective Review

    Directory of Open Access Journals (Sweden)

    IR Ranatunga

    2010-07-01

    Full Text Available This is a retrospective review of 18 patients with tibial plateau fractures Schatzker type VI. These cases were performed in our medical centre from January 2003 to December 2004. The Ilizarov technique (Russian technique using the ring external fixator was the technique performed. Articular reconstruction and joint alignment were achieved with traction and olive wires with washers. One case required percutaneous elevation of the articular surface and bone grafting through a cortical window. Average clinical union was achieved within 4 months of trauma. Mean final knee flexion was 85°, which is compatible with walking. All patients successfully returned to their previous occupations. In conclusion, the Ilizarov technique has been shown to be a good option and a viable tool in the management of these complex and unstable injuries.

  2. Influence of core design, production technique, and material selection on fracture behavior of yttria-stabilized tetragonal zirconia polycrystal fixed dental prostheses produced using different multilayer techniques: split-file, over-pressing, and manually built-up veneers.

    Science.gov (United States)

    Mahmood, Deyar Jallal Hadi; Linderoth, Ewa H; Wennerberg, Ann; Vult Von Steyern, Per

    2016-01-01

    To investigate and compare the fracture strength and fracture mode in eleven groups of currently, the most commonly used multilayer three-unit all-ceramic yttria-stabilized tetragonal zirconia polycrystal (Y-TZP) fixed dental prostheses (FDPs) with respect to the choice of core material, veneering material area, manufacturing technique, design of connectors, and radii of curvature of FDP cores. A total of 110 three-unit Y-TZP FDP cores with one intermediate pontic were made. The FDP cores in groups 1-7 were made with a split-file design, veneered with manually built-up porcelain, computer-aided design-on veneers, and over-pressed veneers. Groups 8-11 consisted of FDPs with a state-of-the-art design, veneered with manually built-up porcelain. All the FDP cores were subjected to simulated aging and finally loaded to fracture. There was a significant difference (Pdesigns, but not between the different types of Y-TZP materials. The split-file designs with VITABLOCS(®) (1,806±165 N) and e.max(®) ZirPress (1,854±115 N) and the state-of-the-art design with VITA VM(®) 9 (1,849±150 N) demonstrated the highest mean fracture values. The shape of a split-file designed all-ceramic reconstruction calls for a different dimension protocol, compared to traditionally shaped ones, as the split-file design leads to sharp approximal indentations acting as fractural impressions, thus decreasing the overall strength. The design of a framework is a crucial factor for the load bearing capacity of an all-ceramic FDP. The state-of-the-art design is preferable since the split-file designed cores call for a cross-sectional connector area at least 42% larger, to have the same load bearing capacity as the state-of-the-art designed cores. All veneering materials and techniques tested in the study, split-file, over-press, built-up porcelains, and glass-ceramics are, with a great safety margin, sufficient for clinical use both anteriorly and posteriorly. Analysis of the fracture pattern shows

  3. Teaching Reluctant Students: Using the Principles and Techniques of Motivational Interviewing to Foster Better Student-Teacher Interactions

    Science.gov (United States)

    Wells, Harvey; Jones, Anna; Jones, Sue C.

    2014-01-01

    In formal learning settings, there will always be instances of resistance to learning from students, resulting in either open conflict or withdrawal and consequent disillusionment on the part of both students and teachers. This paper presents a set of principles and associated practices for responding to disengagement from learning in constructive…

  4. Ideas, properties, and standards of fracture repositioning with osteopathy in traditional Mongolian medicine in China.

    Science.gov (United States)

    Wang, Mei; Wang, Hongxia; Zhao, Namula

    2015-02-01

    To explore the unique ideas, properties, and standards of fracture repositioning with osteopathy in traditional Mongolian medicine in China. Based on the natural life concept of "integration of universe and man", osteopathy in traditional Mongolian medicine in China uses the modern principles and methods of physiology, psychology, and biomechanics. Against this background, we explored the unique ideas, properties, and stan- dards of fracture repositioning in traditional Mongolian medicine. Fracture treatment with osteopathy in traditional Mongolian medicine in China is based on (a) the ideas of natural, sealed, self and dynamic repositioning of fractures; (b) the properties of structural continuity and functional completeness; (c) the standards of "integration of movement and stillness" and "force to force". The unique ideas, properties, and standards of fracture repositioning with osteopathy in traditional Mongolian medicine in China have resulted in the widespread use of such techniques and represents the future direction of the development of fracture repositioning.

  5. A lower border augmentation technique to allow implant placement after a bilateral mandibular fracture as a complication of vertical distraction osteogenesis: a case report.

    Science.gov (United States)

    Perdijk, F B T; Meijer, G J; Soehardi, A; Koole, R

    2013-07-01

    As with other techniques, vertical distraction osteogenesis (VDO) can also induce complications. The case of a patient with a residual alveolar ridge in the symphyseal area of 8 mm is presented. After performing VDO, the patient returned at 1-day postoperatively complaining of pain and dislocation of the distractor device, due to a fracture of the lower mandibular segment on the right side. After removal of the distractor device and application of osteosynthesis plates, the patient returned 2 weeks later due to a second fracture of the lower segment, yet on the left side. After removing the osteosynthesis material, stabilization of the mandible was achieved with an acrylic splint, which was fixated with peri-mandibular wiring. Finally, reconstruction was accomplished by lower border onlay grafting, limited to the symphyseal area, in preparation for implant insertion. Ultimately, after a healing period of 5 months, two endosseous implants were installed. The patient's function has remained satisfactory for 3 years. Reinforcement of the extreme resorbed edentulous mandible after fracture healing by lower border bone augmentation can be a reliable method to allow implant installation in a second stage. Copyright © 2013 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

  6. Study of the hoop fracture behaviour of nuclear fuel cladding from ring compression tests by means of non-linear optimization techniques

    Energy Technology Data Exchange (ETDEWEB)

    Gómez, F.J., E-mail: javier.gomez@amsimulation.com [Advanced Material Simulation, AMS, Bilbao (Spain); Martin Rengel, M.A., E-mail: mamartin.rengel@upm.es [E.T.S.I. Caminos, Canales y Puertos, Universidad Politécnica de Madrid, C/Professor Aranguren SN, E-28040 Madrid (Spain); Ruiz-Hervias, J.; Puerta, M.A. [E.T.S.I. Caminos, Canales y Puertos, Universidad Politécnica de Madrid, C/Professor Aranguren SN, E-28040 Madrid (Spain)

    2017-06-15

    In this work, the hoop fracture toughness of ZIRLO{sup ®} fuel cladding is calculated as a function of three parameters: hydrogen concentration, temperature and displacement rate. To this end, pre-hydrided samples with nominal hydrogen concentrations of 0 (as-received), 150, 250, 500, 1200 and 2000 ppm were prepared. Hydrogen was precipitated as zirconium hydrides in the shape of platelets oriented along the hoop direction. Ring Compression Tests (RCTs) were conducted at three temperatures (20, 135 and 300 °C) and two displacement rates (0.5 and 100 mm/min). A new method has been proposed in this paper which allows the determination of fracture toughness from ring compression tests. The proposed method combines the experimental results, the cohesive crack model, finite elements simulations, numerical calculations and non-linear optimization techniques. The parameters of the cohesive crack model were calculated by minimizing the difference between the experimental data and the numerical results. An almost perfect fitting of the experimental results is achieved by this method. In addition, an estimation of the error in the calculated fracture toughness is also provided.

  7. Characterisation of fracture network and groundwater preferential ...

    African Journals Online (AJOL)

    Characterisation of fractured rocks and evaluation of fracture connectivity are essential for the study of subsurface flow and transport in fractured rock aquifers. In this study, we use a new method to present fracture networks and analyse the connectivity of the fractures, based on the technique of randomly-generated ...

  8. Dynamic intramedullary crosspinning technique for repair of distal femoral fractures in dogs and cats: 71 cases (1981-1985)

    International Nuclear Information System (INIS)

    Whitney, W.O.; Schrader, S.C.

    1987-01-01

    Dynamic intramedullary crosspinning was used in the surgical treatment of supracondylar and distal physeal fractures of the femur in 129 dogs and cats over a 5-year period; the records of the 44 dogs and 27 cats with follow-up information up to time of bony union were evaluated. The results were good or excellent in 66 of 71 animals (93%). The mean follow-up period was 22 months. Distal pin migration was the major complication (10 animals; 14%). The pin migrated before bony union in 2 animals because of instability and collapse at the fracture site. The pin migrated in 8 animals after bony union and was associated with intermittent lameness. In 5 of these, pin removal was performed and the lameness resolved

  9. Comparative Evaluation of Marginal Adaptation and Fracture Strength of Different Ceramic Inlays Produced by CEREC Omnicam and Heat-Pressed Technique

    OpenAIRE

    Oz, F. D.; Bolay, S.

    2018-01-01

    Objective. The aim of this in vitro study was to evaluate marginal adaptation and fracture strength of inlays produced by CEREC Omnicam using different types of blocs and heat-pressed technique. Methods: Seventy-five extracted human mandibular molars were divided randomly into 5 groups (n=15). 60 molars in four groups received MOD inlay preparations. Experimental groups were CO: Intact teeth, EC: IPS e.max CAD and CEREC, LU: Lava Ultimate and CEREC, EL: IPS Empress CAD and CEREC, EP: IPS Empr...

  10. Water quality studied in areas of unconventional oil and gas development, including areas where hydraulic fracturing techniques are used, in the United States

    Science.gov (United States)

    Susong, David D.; Gallegos, Tanya J.; Oelsner, Gretchen P.

    2012-01-01

    Domestic oil and gas production and clean water are critical for economic growth, public health, and national security of the United States. As domestic oil and gas production increases in new areas and old fields are enhanced, there is increasing public concern about the effects of energy production on surface-water and groundwater quality. To a great extent, this concern arises from the improved hydraulic fracturing techniques being used today, including horizontal drilling, for producing unconventional oil and gas in low-permeability formations.

  11. Determining the fracture resistance of fibre-reinforced glass matrix composites by means of the chevron-notch flexural technique

    Czech Academy of Sciences Publication Activity Database

    Boccaccini, A. R.; Kern, H.; Dlouhý, Ivo

    2001-01-01

    Roč. 308, 1/2 (2001), s. 111-117 ISSN 0921-5093 R&D Projects: GA ČR GV101/96/K264 Institutional research plan: CEZ:AV0Z2041904 Keywords : glass matrix composites * fracture toughness * chevron notch test Subject RIV: JH - Ceramics, Fire-Resistant Materials and Glass Impact factor: 0.978, year: 2001

  12. Seismic monitoring of hydraulic fracturing: techniques for determining fluid flow paths and state of stress away from a wellbore

    Energy Technology Data Exchange (ETDEWEB)

    Fehler, M.; House, L.; Kaieda, H.

    1986-01-01

    Hydraulic fracturing has gained in popularity in recent years as a way to determine the orientations and magnitudes of tectonic stresses. By augmenting conventional hydraulic fracturing measurements with detection and mapping of the microearthquakes induced by fracturing, we can supplement and idependently confirm information obtained from conventional analysis. Important information obtained from seismic monitoring includes: the state of stress of the rock, orientation and spacing of the major joint sets, and measurements of rock elastic parameters at locations distant from the wellbore. While conventional well logging operations can provide information about several of these parameters, the zone of interrogation is usually limited to the immediate proximity of the borehole. The seismic waveforms of the microearthquakes contain a wealth of information about the rock in regions that are otherwise inaccessible for study. By reliably locating the hypocenters of many microearthquakes, we have inferred the joint patterns in the rock. We observed that microearthquake locations do not define a simple, thin, planar distribution, that the fault plane solutions are consistent with shear slippage, and that spectral analysis indicates that the source dimensions and slip along the faults are small. Hence we believe that the microearthquakes result from slip along preexisting joints, and not from tensile extension at the tip of the fracture. Orientations of the principal stresses can be estimated by using fault plane solutions of the larger microearthquakes. By using a joint earthquake location scheme, and/or calibrations with downhole detonators, rock velocities and heterogeneities thereof can be investigated in rock volumes that are far enough from the borehole to be representative of intrincis rock properties.

  13. Progress in elastic-plastic fracture mechanics and its applications

    International Nuclear Information System (INIS)

    Paris, P.C.; Zahalak, G.I.

    1980-01-01

    This paper surveys recent developments in the application of J-Integral methods to problems of elastic-plastic fracture. The analytical and experimental development of the J-Integral concept over the last ten years is reviewed briefly. Tearing instability theory is presented in general terms, and specific applications of the theory are discussed. Principles of fracture-proof design are shown to follow naturally from the tearing instability theory. These principles are illustrated first for simple structures, and then generalized to more complex configurations and loading conditions. Examples include multiple member tension structures, beams, frames, nuclear reactor pressure vessel nozzles and piping, and beams on elastic foundations. It is concluded that J-integral based methods offer the best immediate opportunity for the development of sound analytical techniques for treating important practical problems of elastic-plastic fracture

  14. Influence of core design, production technique, and material selection on fracture behavior of yttria-stabilized tetragonal zirconia polycrystal fixed dental prostheses produced using different multilayer techniques: split-file, over-pressing, and manually built-up veneers

    Directory of Open Access Journals (Sweden)

    Mahmood DJH

    2016-02-01

    Full Text Available Deyar Jallal Hadi Mahmood, Ewa H Linderoth, Ann Wennerberg, Per Vult Von Steyern Department of Prosthetic Dentistry, Faculty of Odontology, Malmö University, Malmö, Sweden Aim: To investigate and compare the fracture strength and fracture mode in eleven groups of currently, the most commonly used multilayer three-unit all-ceramic yttria-stabilized tetragonal zirconia polycrystal (Y-TZP fixed dental prostheses (FDPs with respect to the choice of core material, veneering material area, manufacturing technique, design of connectors, and radii of curvature of FDP cores. Materials and methods: A total of 110 three-unit Y-TZP FDP cores with one intermediate pontic were made. The FDP cores in groups 1–7 were made with a split-file design, veneered with manually built-up porcelain, computer-aided design-on veneers, and over-pressed veneers. Groups 8–11 consisted of FDPs with a state-of-the-art design, veneered with manually built-up porcelain. All the FDP cores were subjected to simulated aging and finally loaded to fracture. Results: There was a significant difference (P<0.05 between the core designs, but not between the different types of Y-TZP materials. The split-file designs with VITABLOCS® (1,806±165 N and e.max® ZirPress (1,854±115 N and the state-of-the-art design with VITA VM® 9 (1,849±150 N demonstrated the highest mean fracture values. Conclusion: The shape of a split-file designed all-ceramic reconstruction calls for a different dimension protocol, compared to traditionally shaped ones, as the split-file design leads to sharp approximal indentations acting as fractural impressions, thus decreasing the overall strength. The design of a framework is a crucial factor for the load bearing capacity of an all-ceramic FDP. The state-of-the-art design is preferable since the split-file designed cores call for a cross-sectional connector area at least 42% larger, to have the same load bearing capacity as the state-of-the-art designed

  15. Influence of various bonding techniques on the fracture strength of thin CAD/CAM-fabricated occlusal glass-ceramic veneers.

    Science.gov (United States)

    Yazigi, Christine; Kern, Matthias; Chaar, Mohamed Sad

    2017-11-01

    To evaluate the efficiency of immediate dentin sealing and the effects of different bonding protocols on the fracture strength of CAD/CAM occlusal veneers bonded to exposed dentin. Ninety-six extracted maxillary premolars were initially divided into three main groups with 32 specimens each: without immediate dentin sealing, immediate dentin sealing/total etching and immediate dentin sealing/selective etching. Teeth were identically prepared in the dentin to receive occlusal veneers of 0.8mm thickness, milled from lithium disilicate ceramic blocks (IPS e.max CAD). Each main group was later subdivided, according to the pre-cementation surface etching protocol (total/selective), into two subgroups with 16 specimens each. All restorations were adhesively bonded using a resin cement (Variolink Esthetic). Half of the specimens of each subgroup were subjected to thermo-dynamic loading in a chewing simulator with 1,200,000 cycles at 10kg load. The other half and the surviving specimens were subjected to quasi-static loading until failure. Statistical analysis was performed using three-way ANOVA and Tukey's post-hoc tests. All specimens except one survived the artificial aging. A significantly higher fracture strength of restorations (p ≤ 0.001) was obtained when immediate dentin sealing was followed regardless of the etching method with values ranging from a minimum of 1122 ± 336N to a maximum of 1853 ± 333N. Neither the pre-cementation treatment nor the artificial aging had a statistical significant effect on the fracture strength. Immediate dentin sealing protocol is recommended whenever dentin is exposed during the preparation for thin glass-ceramic occlusal veneers. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Study of deformation and fracture micro mechanisms of titanium alloy Ti-6Al-4V using electron microscopy and and X-ray diffraction techniques

    International Nuclear Information System (INIS)

    Morcelli, Aparecido Edilson

    2009-01-01

    This present work allowed the study of deformation and fracture micro mechanisms of titanium alloy Ti-6Al-4V, used commercially for the manufacture of metallic biomaterials. The techniques employed for the analysis of the material under study were: scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD). The study of the influence and behavior of the phases present in titanium alloys is important to evaluate the behavior of cracks in titanium alloys with high mechanical strength, which have fine alpha (α), beta (β) and (α±β) microstructure, linking the presence of the phases with the strength of the material. The evaluation in situ of deformation and fracture micro mechanisms were performed by TEM and was also a study of phase transformations during cooling in titanium alloys, using the techniques of bright field, dark field and diffraction of electrons in the selected area. After heat treatment differences were observed between the amount of in relation to the original microstructure of the β and α phases material for different conditions used in heat treatment applied to the alloy. The presence of lamellar microstructure formed during cooling in the β field was observed, promoting the conversion of part of the secondary alpha structure in β phase, which was trapped between the lamellar of alpha. (author)

  17. A new surgical technique for traumatic dislocation of posterior tibial tendon with avulsion fracture of medial malleolus.

    Science.gov (United States)

    Jeong, Soon-Taek; Hwang, Sun-Chul; Kim, Dong-Hee; Nam, Dae-Cheol

    2015-01-01

    We introduce a case of traumatic dislocation of the posterior tibial tendon with avulsion fracture of the medial malleolus in a 52-year-old female patient who was treated surgically with periosteal flap and suture anchor fixation. Based in the posteromedial ridge of the distal tibia, a quadrilateral periosteal flap was created and folded over the tendon, followed by fixation on the lateral aspect of the groove by use of multiple suture anchors. Clinical and radiological findings 25 months postoperatively showed well-preserved function of the ankle joint with stable tendon gliding.

  18. The anterolateral supra-fibular-head approach for plating posterolateral tibial plateau fractures: A novel surgical technique.

    Science.gov (United States)

    Hu, Sun-Jun; Chang, Shi-Min; Zhang, Ying-Qi; Ma, Zhuo; Du, Shou-Chao; Zhang, Kai

    2016-02-01

    The posterolateral (PL) tibial plateau quadrant is laterally covered by the fibular head and posteriorly covered by a mass of muscle ligament and important neurovascular structures. There are several limitations in exposing and fixing the PL tibial plateau fractures using a posterior approach. The aim of this study is to present a novel anterolateral supra-fibular-head approach for plating PL tibial plateau fractures. Five fresh and ten preserved knee specimens were dissected to measure the following parameters:1) the vertical distance from the apex of the fibular head to the lateral plateau surface, 2) the transverse distance between the PL platform and fibula collateral ligament (FCL), and 3) the tension of the FCL in different knee flexion positions. Clinically, isolated PL quadrant tibial plateau fractures were treated via an anterolateral supra-fibular-head approach and lateral rafting plate fixation. The outcome of the patients was assessed after a short to medium follow-up period. The distance from the apex of the fibular head to the lateral condylar surface was 12.2 ± 1.6 mm on average. With the knee extended and the FCL tensioned, the transverse distance between the PL platform and the FCL was 6.7 ± 1.1 mm. With the knee flexed to 60° and the FCL was in the most relaxed position, the distance increased to 21.1 ± 3.0 mm. Clinically, a series of 7 cases of PL tibial plateau fractures were treated via this anterolateral supra-fibular-head approach. The patient was placed in a lateral decubitus position with the knee flexed to approximately 60 degrees. After the posterior retraction of the FCL, the plate was placed more posteriorly to provide a raft or horizontal belt fixation of the PL tibial plateau fragment. After an average of 14.3 months of follow up, the knee range of motion(ROM) was 121.4° ± 8.8° (range: 105°-135°), the HSS score was 96.7 ± 2.6 (range: 90-100), and the SMFA dysfunction score was 22.4 ± 3.8 (range: 16-28) points. The

  19. The basic principles of the application of sterile insect technique for area-wide insect pest control

    International Nuclear Information System (INIS)

    Singgih Sutrisno

    2006-01-01

    Sterile Insect Technique (SIT) is a new insect pest control technique, potential, and compatible to other techniques. This technique includes irradiation of insect colony in the laboratory using gamma, n, or x-rays and then release them in the field periodically to obtain the increase of sterility probability level from the first generation to the dependence as the result the decrease of the fertility level in the field. The effect the release of sterile insects ( 9:1 ratio to the male indigenous and reproductive potential every single female of each generation reproduce 5 females ) to the insect reduction population model is conceptually discussed. From one million of the female parental decrease to be 26, 316; 1,907; 10; and 0 insects at the first, second, third, and the forth progeny respectively. Then if sterile insect technique integrated with chemical technique (insecticide) 90% kill, it will be much more effective compared to the application sterile insect technique only. From the number of one million population of insects will decrease to be 2,632; 189; and 0 insects at the first, second, and the third progeny respectively. In the Lepidoptera insects was found a phenomenon of inherited sterility. According to Knipling (1970) the inherited sterility in the first offspring caused by chromosome translocation in the gamete . In the individual of heterozygote will be die and in the homozygotes is still alive. Interspecific hybrid sterility first time was found by Laster (1972) from a cross between males Heliothis virescens (F) and females Heliothis subflexa Guenee. Male moths of the first offspring from the cross between H. virescens and H. subflexa is sterile and the females still remain fertile. If the female moths of the first offspring back crossed with male H. virescens the phenomenon of sterility always found will same situation as mention earlier the male offspring is sterile and the females is fertile ( the male F2 will be sterile and the females will

  20. Fundamental principles, measurement techniques and data analysis in a ion accelerator; Principios fundamentales, tecnicas de medicion y analisis de datos en un acelerador de iones

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez M, O. [Facultad de Ciencias, UNAM, Ciudad Universitaria, 04510 Mexico D. F. (Mexico); Gleason, C. [Facultad de Ciencias, Universidad Autonoma del Estado de Morelos, Cuernavaca, Morelos (Mexico); Hinojosa, G. [Instituto de Ciencias Fisicas, UNAM, Ciudad Universitaria, 04510 Mexico D. F. (Mexico)]. e-mail: hinojosa@fis.unam.mx

    2008-07-01

    The present work is intended to be a general reference for students and professionals interested in the field. Here, we present an introduction to the analysis techniques and fundamental principles for data processing and operation of a typical ion accelerator that operates in the low energy range. We also present a detailed description of the apparatus and propose new analysis methods for the results. In addition, we introduce illustrative simulations of the ion's trajectories in the different components of the apparatus performed with specialized software and, a new computer data acquisition and control interface. (Author)

  1. Development of innovative techniques and principles that may be used as models to improve plant performance. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Hanna, Wayne W.; Burton, Glenn W.

    2000-06-25

    We developed fundamental methods and techniques for transferring germplasm from wild to cultivated species. Germplasm transferred included diverse cytoplasms, new genes for pest resistance, genes controlling dry matter yield and apomixis. Some of the germplasm has been shown to be valuable in plant breeding and has been incorporated into commercial cultivators.

  2. Polymer liquids fracture like solids

    DEFF Research Database (Denmark)

    Huang, Qian; Hassager, Ole

    2017-01-01

    While fracture in brittle solids has been studied for centuries until today, there are few studies on fracture in polymer liquids. Recent developments in experimental techniques, especially the combination of controlled filament stretching rheometry and high speed imaging, have opened new windows...... into the detailed study of fracture processes for polymer liquids. High speed imaging shows that polymer liquids fracture like solids with initiation and propagation of an edge fracture. However, remarkable features such as highly reproducible critical stress, independent appearance of multiple fractures...

  3. Characterization of fracture and deformation mechanism in a high strength beta titanium alloy Ti-10-2-3 using EBSD technique

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Jalaj, E-mail: jalaj@dmrl.drdo.in; Singh, Vajinder; Ghosal, Partha; Kumar, Vikas

    2015-01-19

    In the present study, fracture toughness tested specimens in longitudinal (LT) and transverse loading (TL) directions of beta titanium alloy have been investigated using Electron Back Scattered Diffraction (EBSD) technique. The orientation images captured at three different locations i.e. machine notch, fatigue pre-crack and final fracture have been compared. The LT sample exhibits with more facets than TL sample. The faceted aspect of the crack is generally associated with quasi-cleavage mechanism. The EBSD analysis clearly points out that in the LT specimen, the hexagonal orientation has moved towards near basal during the test. This may be the reason for the observance of facets in the LT specimen. The cracking in TL specimen might have been taken over by the bcc phase as it is oriented with harder planes of cubic {001} planes. Further, the Schmid factor has also been computed based on the defined loading conditions. Significant variation has been observed in the slip plane orientations and distributions at these three locations. The Schmid analysis has highlighted the significant contribution of different slip systems towards deformation and cracking in LT and TL specimens.

  4. A small punch test technique for characterizing the elastic modulus and fracture behavior of PMMA bone cement used in total joint replacement.

    Science.gov (United States)

    Giddings, V L; Kurtz, S M; Jewett, C W; Foulds, J R; Edidin, A A

    2001-07-01

    Polymethylmethacrylate (PMMA) bone cement is used in total joint replacements to anchor implants to the underlying bone. Establishing and maintaining the integrity of bone cement is thus of critical importance to the long-term outcome of joint replacement surgery. The goal of the present study was to evaluate the suitability of a novel testing technique, the small punch or miniaturized disk bend test, to characterize the elastic modulus and fracture behavior of PMMA. We investigated the hypothesis that the crack initiation behavior of PMMA during the small punch test was sensitive to the test temperature. Miniature disk-shaped specimens, 0.5 mm thick and 6.4 mm in diameter, were prepared from PMMA and Simplex-P bone cement according to manufacturers' instructions. Testing was conducted at ambient and body temperatures, and the effect of test temperature on the elastic modulus and fracture behavior was statistically evaluated using analysis of variance. For both PMMA materials, the test temperature had a significant effect on elastic modulus and crack initiation behavior. At body temperature, the specimens exhibited "ductile" crack initiation, whereas at room temperature "brittle" crack initiation was observed. The small punch test was found to be a sensitive and repeatable test method for evaluating the mechanical behavior of PMMA. In light of the results of this study, future small punch testing should be conducted at body temperature.

  5. Cephalomedullary fixation for femoral neck/intertrochanteric and ipsilateral shaft fractures: surgical tips and pitfalls

    Directory of Open Access Journals (Sweden)

    Bali Kamal

    2013-02-01

    Full Text Available 【Abstract】Objective: Surgical management op-tions for femoral shaft fracture and ipsilateral proximal fe-mur fracture vary from single-implant to double-implant fixation. Cephalomedullary fixation in such fractures has rela-tive advantages over other techniques especially because of less soft tissue dissection and immediate postoperative weight bearing with accelerated rehabilitation. However, the surgery is technically demanding and there is a paucity of literature describing the surgical techniques for this fixation. The aim of the study was to describe the surgical technique of cephalomedullary fixation for femoral shaft fracture and ipsilateral proximal femur fracture. Methods: Sixteen cases (10 males and 6 females with a mean age of 41.8 years of ipsilateral proximal femur and shaft fractures were treated by single-stage cephalomedullary fixa-tion at tertiary level trauma center in northern India. The fractures were classified according to AO classification. An intraoperative record of duration of surgery as well as tech-nical challenges unique to each fracture pattern was kept for all the patients. Results: The most common proximal femoral pattern was AO B2.1 observed in 9 of our patients. The AO B2.3 fractures were seen in 4 patients while the AO A1.2 fractures in 3 patients. Four of the AO B2.1 and 2 of the AO B2.3 frac-tures required open reduction with Watson-Jones approach. The mean operative time was around 78 minutes, which tended to decrease as the surgical experience increased. There was only one case of malreduction, which required revision surgery. Conclusion: Combination of ipsilateral femoral shaft fracture and neck/intertrochanteric fracture is a difficult frac-ture pattern for trauma surgeons. Cephalomedullary nail is an excellent implant for such fractures but it requires careful insertion to avoid complications. Surgery is technically de-manding with a definite learning curve. Nevertheless, a ma-jority of these

  6. Comparison Of Lateral Mass Screw Fixation Technique And Hartshill Rectangle Technique In The Treatment Of Sub-Axial Cervical Spine Fractures

    Directory of Open Access Journals (Sweden)

    Mohit KM

    2012-11-01

    Full Text Available INTRODUCTION: Cervical injury in a polytrauma patient is one of the most critical injuries. The aim of this study was to compare the lateral mass screw technique with the Hartshill rectangle technique for treatment of such cases. MATERIALS AND METHODS: This prospective study consisted of 40 patients. Both groups were followed for three years clinically and radiologically. RESULTS: In the lateral mass technique, there were no cases of vertebral artery injury, radiculopathy, screw pullout, dural tears, residual kyphosis or persistent pain. In the Hartshill technique 3 patients experienced intra- operative dural tears, 1 case of wire breakage at the six months follow up, 6 patients with persistent neck pain and 1 with worsening neurological status. One hundred per cent fusion was achieved in both groups. There was significant radiation exposure in the lateral mass group. Post-operative immobilisation was required only in the Hartshill. CONCLUSION: Lateral mass screw technique is definitely a relatively better procedure. But Hartshill rectangle still stands out in certain practical situations.

  7. Osteoporotic Hip and Spine Fractures

    OpenAIRE

    Cannada, Lisa K.; Hill, Brian W.

    2014-01-01

    Hip and spine fractures represent just a portion of the burden of osteoporosis; however, these fractures require treatment and often represent a major change in lifestyle for the patient and their family. The orthopedic surgeon plays a crucial role, not only in the treatment of these injuries but also providing guidance in prevention of future osteoporotic fractures. This review provides a brief epidemiology of the fractures, details the surgical techniques, and outlines the current treatment...

  8. Characterization of infiltration into fractured, welded tuff using small borehole data collection technique: State of Nevada, agency for nuclear projects/nuclear waste project office

    International Nuclear Information System (INIS)

    Linderfelt, W.

    1986-10-01

    Knowledge of all aspects of the hydrologic cycle is required for consideration of Yucca mountain as a high level radioactive waste site. Surface processes are especially important in controlling the quantity and quality of water infiltrating into the unsaturated zone, available for recharging the aquifer. The investigation reported herein uses small bore drill holes to access the near surface fractured rock environment. The study was conducted in northern Nevada at the north end of the Pah Rah range, east of Pyramid Lake as an analog to Yucca Mountain. The results of this study will be used to better understand the chemistry and flow of the near surface flow regime of Yucca Mountain and to evaluate proposed techniques for use in future investigations. 7 refs., 6 figs., 3 tabs

  9. Comparison of experimental techniques for measuring fracture toughness of austenitic stainless steels by performance of a comparative round-robin test

    International Nuclear Information System (INIS)

    Huthmann, H.; Akhurst, K.N.; Bethmont, M.; Picker, C.; Rongen, H.J.M. van; Soulat, P.

    1987-01-01

    The CEC fast breeder coordinating committee, activities group 3 Materials of the working group for codes and standards, has recently examined existing data on the fracture toughness of austenitic stainless steels. As a result, the committee decided to sponsor a round robin test programme aimed at comparing experimental techniques and assisting in establishing a standard test method for these steels. The contract for this programme was placed with Interatom, who have subcontracted with CEA-Saclay, CEGB-Leatherhead, TNO-Apeldoorn and UKAEA-Risley. Additionally CISE/ENEL-Milano and EdF-Les Renardieres took part in the round robin. This final report presents a common evaluation and discussion of the results gained by the different laboratories

  10. Principles and practice of radiation safety and protection in the application of nuclear techniques in water resource development and management

    International Nuclear Information System (INIS)

    Mallam, S. P.

    2000-07-01

    Nigeria, as is the case with many other countries of the world, is facing a problem with water supply and there is therefore a need to diversify the technology employed in the search for and management of water resources. Nuclear technology, including the use of isotopes (natural and artificial) has been found to be able to play a vital role in this search. The application of this technology is wide and varied in the types of radiation sources that can be applied as well as the type of problems that need to be solved. for example, in the search for groundwater, environmental isotopes such as 3 H and 14 C may be applied while NAA and XRF may become useful in the monitoring of fresh water quality. Neutron moisture probes and gamma-gamma well logging are sources of radiation that may be employed in the management of water sources for proper irrigation just as active and stable isotopes may be applied as tracers for the detection of leaks in pipes for domestic water. Because of this diversity, the radiation safety and protection problems associated with the application of nuclear technology in water resource development and management will depend on the particular condition of use. In this paper the aspects of radiation safety and the protection of human health and the environment from the detrimental effects of ionising radiation will be considered. The presentation will underscore the importance of an understanding of the nature and properties of ionising radiation and the associated hazards, familiarise participants with terminology used in radiation protection, highlight the relevant legislation in radiation safety and protection, give the basic principles of radiation protection with an emphasis on the importance of keeping doses as low as reasonably achievable (ALARA)

  11. MO-B-BRD-03: Principles, Pitfalls and Techniques of 3D Printing for Bolus and Compensators

    International Nuclear Information System (INIS)

    Baker, J.

    2015-01-01

    This session is designed so that the learning objectives are practical. The intent is that the attendee may take home an understanding of not just the technology, but also the logistical steps necessary to execute these 3D printing techniques in the clinic. Four practical 3D printing topics will be discussed: (i) Creating bolus and compensators for photon machines; (ii) tools for proton therapy; (iii) clinical applications in imaging; (iv) custom phantom design for clinic and research use. The use of 3D printers within the radiation oncology setting is proving to be a useful tool for creating patient specific bolus and compensators with the added benefit of cost savings. Creating the proper protocol is essential to ensuring that the desired effect is achieved and modeled in the treatment planning system. The critical choice of printer material (since it determines the interaction with the radiation) will be discussed. Selection of 3D printer type, design methods, verification of dose calculation, and the printing process will be detailed to give the basis for establishing your own protocol for electron and photon fields. A practical discussion of likely obstacles that may be encountered will be included. The diversity of systems and techniques in proton facilities leads to different facilities having very different requirements for beam modifying hardware and quality assurance devices. Many departments find the need to design and fabricate facility-specific equipment, making 3D printing an attractive technology. 3D printer applications in proton therapy will be discussed, including beam filters and compensators, and the design of proton therapy specific quality assurance tools. Quality control specific to 3D printing in proton therapy will be addressed. Advantages and disadvantages of different printing technology for these applications will also be discussed. 3D printing applications using high-resolution radiology-based imaging data will be presented. This data

  12. MO-B-BRD-03: Principles, Pitfalls and Techniques of 3D Printing for Bolus and Compensators

    Energy Technology Data Exchange (ETDEWEB)

    Baker, J. [Stony Brook University Medical Center (United States)

    2015-06-15

    This session is designed so that the learning objectives are practical. The intent is that the attendee may take home an understanding of not just the technology, but also the logistical steps necessary to execute these 3D printing techniques in the clinic. Four practical 3D printing topics will be discussed: (i) Creating bolus and compensators for photon machines; (ii) tools for proton therapy; (iii) clinical applications in imaging; (iv) custom phantom design for clinic and research use. The use of 3D printers within the radiation oncology setting is proving to be a useful tool for creating patient specific bolus and compensators with the added benefit of cost savings. Creating the proper protocol is essential to ensuring that the desired effect is achieved and modeled in the treatment planning system. The critical choice of printer material (since it determines the interaction with the radiation) will be discussed. Selection of 3D printer type, design methods, verification of dose calculation, and the printing process will be detailed to give the basis for establishing your own protocol for electron and photon fields. A practical discussion of likely obstacles that may be encountered will be included. The diversity of systems and techniques in proton facilities leads to different facilities having very different requirements for beam modifying hardware and quality assurance devices. Many departments find the need to design and fabricate facility-specific equipment, making 3D printing an attractive technology. 3D printer applications in proton therapy will be discussed, including beam filters and compensators, and the design of proton therapy specific quality assurance tools. Quality control specific to 3D printing in proton therapy will be addressed. Advantages and disadvantages of different printing technology for these applications will also be discussed. 3D printing applications using high-resolution radiology-based imaging data will be presented. This data

  13. Use of orthodontic brackets for intermaxillary fixation for management of mandibular fracture in a pediatric patient

    Directory of Open Access Journals (Sweden)

    Rajeev Pandey

    2017-01-01

    Full Text Available Fracture of mandible is relatively less common in pediatric population when compared to adults. Management of pediatric mandibular fracture is a very complex issue and requires accurate and early treatment. Although the general principles of treatment remain the same as adult but various factors which influence the choice of management: age, dentition status, site involved, amount of displacement, number of fractures, and socioeconomic status. This case report describes a conservative way of management of moderately displaced mandibular fracture with the help of closed reduction achieved using intermaxillary fixation (IMF with help of elastics using orthodontic brackets. A 9-year-old male child was treated for body of mandible fracture using this technique. The IMF was removed after 3 weeks and adequate bone union was demonstrated clinically and radiographically.

  14. Cosmological principles. II. Physical principles

    International Nuclear Information System (INIS)

    Harrison, E.R.

    1974-01-01

    The discussion of cosmological principle covers the uniformity principle of the laws of physics, the gravitation and cognizability principles, and the Dirac creation, chaos, and bootstrap principles. (U.S.)

  15. Fracture mechanics and parapsychology

    Science.gov (United States)

    Cherepanov, G. P.

    2010-08-01

    The problem of postcritical deformation of materials beyond the ultimate strength is considered a division of fracture mechanics. A simple example is used to show the relationship between this problem and parapsychology, which studies phenomena and processes where the causality principle fails. It is shown that the concept of postcritical deformation leads to problems with no solution

  16. A review on risk assessment techniques for hydraulic fracturing water and produced water management implemented in onshore unconventional oil and gas production.

    Science.gov (United States)

    Torres, Luisa; Yadav, Om Prakash; Khan, Eakalak

    2016-01-01

    The objective of this paper is to review different risk assessment techniques applicable to onshore unconventional oil and gas production to determine the risks to water quantity and quality associated with hydraulic fracturing and produced water management. Water resources could be at risk without proper management of water, chemicals, and produced water. Previous risk assessments in the oil and gas industry were performed from an engineering perspective leaving aside important social factors. Different risk assessment methods and techniques are reviewed and summarized to select the most appropriate one to perform a holistic and integrated analysis of risks at every stage of the water life cycle. Constraints to performing risk assessment are identified including gaps in databases, which require more advanced techniques such as modeling. Discussions on each risk associated with water and produced water management, mitigation strategies, and future research direction are presented. Further research on risks in onshore unconventional oil and gas will benefit not only the U.S. but also other countries with shale oil and gas resources. Copyright © 2015 Elsevier B.V. All rights reserved.

  17. Hip Fracture

    Science.gov (United States)

    ... hip fractures in people of all ages. In older adults, a hip fracture is most often a result of a fall from a standing height. In people with very weak bones, a hip fracture can occur simply by standing on the leg and twisting. Risk factors The rate of hip fractures increases substantially with ...

  18. Study of leakages at dam sites in fractured rocks with the aid of the borehole dilution technique

    International Nuclear Information System (INIS)

    Ozbek, E.

    1978-02-01

    The connection between springs which occurred after the impoundment of Keban Lake and the lake was proved by tritium measurements. By additional application of single borehole techniques using radioisotopes as tracers it was possible to localize solution channels in the karstic aquifer as preferential paths for the water movement

  19. The SAFT-UT (synthetic aperture focusing technique for ultrasonic testing) real-time inspection system: Operational principles and implementation

    Energy Technology Data Exchange (ETDEWEB)

    Hall, T. E.; Reid, L. D.; Doctor, S. R.

    1988-06-01

    This document provides a technical description of the real-time imaging system developed for rapid flaw detection and characterization utilizing the synthetic aperture focusing technique for ultrasonic testing (SAFT-UT). The complete fieldable system has been designed to perform inservice inspection of light-water reactor components. Software was written on a DEC LSI 11/23 computer system to control data collection. The unprocessed data is transferred to a VAX 11/730 host computer to perform data processing and image display tasks. A parallel architecture peripheral to the host computer, referred to as the Real-Time SAFT Processor, rapidly performs the SAFT processing function. From the host's point of view, this device operates on the SAFT data in such a way that one may consider it to be a specialized or SAFT array processor. A guide to SAFT-UT theory and conventions is included, along with a detailed description of the operation of the software, how to install the software, and a detailed hardware description.

  20. Partially to fully saturated flow through smooth, clean, open fractures: qualitative experimental studies

    Science.gov (United States)

    Jones, Brendon R.; Brouwers, Luke B.; Dippenaar, Matthys A.

    2018-05-01

    Fractures are both rough and irregular but can be expressed by a simple model concept of two smooth parallel plates and the associated cubic law governing discharge through saturated fractures. However, in natural conditions and in the intermediate vadose zone, these assumptions are likely violated. This paper presents a qualitative experimental study investigating the cubic law under variable saturation in initially dry free-draining discrete fractures. The study comprised flow visualisation experiments conducted on transparent replicas of smooth parallel plates with inlet conditions of constant pressure and differing flow rates over both vertical and horizontal inclination. Flow conditions were altered to investigate the influence of intermittent and continuous influx scenarios. Findings from this research proved, for instance, that saturated laminar flow is not likely achieved, especially in nonhorizontal fractures. In vertical fractures, preferential flow occupies the minority of cross-sectional area despite the water supply. Movement of water through the fractured vadose zone therefore becomes a matter of the continuity principle, whereby water should theoretically be transported downward at significantly higher flow rates given the very low degree of water saturation. Current techniques that aim to quantify discrete fracture flow, notably at partial saturation, are questionable. Inspired by the results of this study, it is therefore hypothetically improbable to achieve saturation in vertical fractures under free-draining wetting conditions. It does become possible under extremely excessive water inflows or when not free-draining; however, the converse is not true, as a wet vertical fracture can be drained.

  1. Partially to fully saturated flow through smooth, clean, open fractures: qualitative experimental studies

    Science.gov (United States)

    Jones, Brendon R.; Brouwers, Luke B.; Dippenaar, Matthys A.

    2017-11-01

    Fractures are both rough and irregular but can be expressed by a simple model concept of two smooth parallel plates and the associated cubic law governing discharge through saturated fractures. However, in natural conditions and in the intermediate vadose zone, these assumptions are likely violated. This paper presents a qualitative experimental study investigating the cubic law under variable saturation in initially dry free-draining discrete fractures. The study comprised flow visualisation experiments conducted on transparent replicas of smooth parallel plates with inlet conditions of constant pressure and differing flow rates over both vertical and horizontal inclination. Flow conditions were altered to investigate the influence of intermittent and continuous influx scenarios. Findings from this research proved, for instance, that saturated laminar flow is not likely achieved, especially in nonhorizontal fractures. In vertical fractures, preferential flow occupies the minority of cross-sectional area despite the water supply. Movement of water through the fractured vadose zone therefore becomes a matter of the continuity principle, whereby water should theoretically be transported downward at significantly higher flow rates given the very low degree of water saturation. Current techniques that aim to quantify discrete fracture flow, notably at partial saturation, are questionable. Inspired by the results of this study, it is therefore hypothetically improbable to achieve saturation in vertical fractures under free-draining wetting conditions. It does become possible under extremely excessive water inflows or when not free-draining; however, the converse is not true, as a wet vertical fracture can be drained.

  2. An alternative method in mandibular fracture treatment: bone graft use instead of a plate.

    Science.gov (United States)

    Alagöz, Murat Sahin; Uysal, Ahmet Cagri; Sensoz, Omer

    2008-03-01

    In the treatment of the mandibular fractures, one of the main principles is to use the least amount of foreign material. We present an alternative technique that the bone grafts harvested from the fracture borders or from the iliac crest were used instead of plates and the fixation was done with screws. In the study including 24 mandible fractures, the bone grafts harvested from the fracture borders were used in the 10 favorable fractures and the bone grafts harvested from the iliac crest were used in the 14 unfavorable fractures. In the combined mandible fractures, four fractures were fixated with titanium plates and the other side with the bone graft. The patients, who were followed up for 12 to 20 months, were evaluated with macroscopic occlusion, panoramic graphs, and three-dimensional computerized tomographs. The advantage of this technique of fixation with the autogenous tissue is reduced infection rates and reduced operation costs. In the pediatric patients, the second session operation of plate removal is not necessary.

  3. Management of civilian ballistic fractures.

    Science.gov (United States)

    Seng, V S; Masquelet, A C

    2013-12-01

    The management of ballistic fractures, which are open fractures, has often been studied in wartime and has benefited from the principles of military surgery with debridement and lavage, and the use of external fixation for bone stabilization. In civilian practice, bone stabilization of these fractures is different and is not performed by external fixation. Fifteen civilian ballistic fractures, Gustilo II or IIIa, two associated with nerve damage and none with vascular damage, were reviewed. After debridement and lavage, ten internal fixations and five conservative treatments were used. No superficial or deep surgical site infection was noted. Fourteen of the 15 fractures (93%) healed without reoperation. Eleven of the 15 patients (73%) regained normal function. Ballistic fractures have a bad reputation due to their many complications, including infections. In civilian practice, the use of internal fixation is not responsible for excessive morbidity, provided debridement and lavage are performed. Civilian ballistic fractures, when they are caused by low-velocity firearms, differ from military ballistic fractures. Although the principle of surgical debridement and lavage remains the same, bone stabilization is different and is similar to conventional open fractures. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

  4. Comparison of the Effect of Canal Preparation by Step Back Technique Using Hand Instruments and Gates Glidden Drills with ProTaper Universal Rotary System on the Root Resistance to Vertical Fracture

    Directory of Open Access Journals (Sweden)

    A Abbaszadegan

    2013-06-01

    Full Text Available Introduction: Cleaning and shaping of the root canal system with an efficient and safe technique are the major goals of root canal treatment. The aim of this study was to compare the conventional root canal preparation technique by hand instruments and Gates Glidden drills with ProTaper Universal Rotary system on the root susceptibility to vertical fracture. Methods: Thirty extracted human mandibular premolars were randomly assigned to two groups. In group I, apical preparation was performed with k-files up to #40 utilizing step back technique and coronal flaring was done with Gates Glidden drills. In group II, ProTaper Universal Rotary instruments were used up to the file F4. All teeth were obturated with lateral compaction technique using gutta-percha and AH26 sealer. A simulated periodontal ligament was fabricated, and the teeth were mounted. A stainless steel finger spreader #35 was mounted in an Instron testing machine and the necessary load to cause a root fracture was inserted and recorded. The obtained data were analyzed statistically using T-test. Results: The force required to fracture was significantly lower for the roots prepared by ProTaper instruments in comparison with the specimens prepared by hand instruments and Gates Glidden drills (P< 0.001. Conclusion: Canal preparation with ProTaper rotary instruments can make the roots more susceptible to vertical fracture than traditional instrumentation with k-files and Gates Glidden drills.

  5. Comparison of the Effect of Canal Preparation by Step Back Technique Using Hand Instruments and Gates Glidden Drills with ProTaper Universal Rotary System on the Root Resistance to Vertical Fracture

    OpenAIRE

    A Abbaszadegan; Z Sadat Aleyasin; M Sedigh Shamsi; Sh Shahriari

    2013-01-01

    Introduction: Cleaning and shaping of the root canal system with an efficient and safe technique are the major goals of root canal treatment. The aim of this study was to compare the conventional root canal preparation technique by hand instruments and Gates Glidden drills with ProTaper Universal Rotary system on the root susceptibility to vertical fracture. Methods: Thirty extracted human mandibular premolars were randomly assigned to two groups. In group I, apical preparation was performed ...

  6. Classical fracture mechanics methods

    International Nuclear Information System (INIS)

    Schwalbe, K.H.; Heerens, J.; Landes, J.D.

    2007-01-01

    Comprehensive Structural Integrity is a reference work which covers all activities involved in the assurance of structural integrity. It provides engineers and scientists with an unparalleled depth of knowledge in the disciplines involved. The new online Volume 11 is dedicated to the mechanical characteristics of materials. This paper contains the chapter 11.02 of this volume and is structured as follows: Test techniques; Analysis; Fracture behavior; Fracture toughness tests for nonmetals

  7. Rib Fractures

    Science.gov (United States)

    ... Video) Achilles Tendon Tear Additional Content Medical News Rib Fractures By Thomas G. Weiser, MD, MPH, Associate Professor, ... Tamponade Hemothorax Injury to the Aorta Pulmonary Contusion Rib Fractures Tension Pneumothorax Traumatic Pneumothorax (See also Introduction to ...

  8. Root fractures

    DEFF Research Database (Denmark)

    Andreasen, Jens Ove; Christensen, Søren Steno Ahrensburg; Tsilingaridis, Georgios

    2012-01-01

    The purpose of this study was to analyze tooth loss after root fractures and to assess the influence of the type of healing and the location of the root fracture. Furthermore, the actual cause of tooth loss was analyzed....

  9. Bernoulli's Principle

    Science.gov (United States)

    Hewitt, Paul G.

    2004-01-01

    Some teachers have difficulty understanding Bernoulli's principle particularly when the principle is applied to the aerodynamic lift. Some teachers favor using Newton's laws instead of Bernoulli's principle to explain the physics behind lift. Some also consider Bernoulli's principle too difficult to explain to students and avoid teaching it…

  10. Use of nanoindentation technique for a better understanding of the fracture toughness of Strombus gigas conch shell

    International Nuclear Information System (INIS)

    Romana, L.; Thomas, P.; Bilas, P.; Mansot, J.L.; Merrifiels, M.; Bercion, Y.; Aranda, D. Aldana

    2013-01-01

    In this work the nanochemical properties of the composite organomineral biomaterial constituting Strombus gigas conch shell are studied by means of dynamic mechanical analyses associated to nanoidentation technique. The measurements are performed on shell samples presenting different surface orientations relative to the growth axis of the conch shell. The influence of the organic component of the biomaterial on its nanomechanical properties is also investigated by studying fresh and dried S. gigas conch shells. Monocrystalline aragonite is used as a reference. For the understanding of nanochemical behaviour, special attention is paid to the pop in events observed on the load/displacement curves which results from nanofractures' initiation and propagation occuring during the load process. In order to better understand the mechanical properties systematic studies of the structure and morphology are performed using scanning electron microscopy, atomic force microscopy and X-ray diffractometry. The hardness and Young's modulus values measured on bio aragonite samples are close to those of the aragonite mineral standard. This surprising result shows that, H and E values are not related to the bio composition and lamellar structure of the bio aragonite. However, it was found that the organic layer and the micro architecture strongly influence the nanofracture initiation and propagation processes in the samples. Statistic study of the pop-in events can help to predict the macroscopic mechanical behaviour of the material. - Highlights: ► Nanomechanical properties of Strombus gigas conch shell ► Low influence of the crossed lamellar structure on H and E values at the nano scale ► Strong influence of the crossed lamellar on nanocracks initiation ► Correlation between mechanical behaviors at the macro and nano scales

  11. Stress Fractures

    Science.gov (United States)

    Stress fractures Overview Stress fractures are tiny cracks in a bone. They're caused by repetitive force, often from overuse — such as repeatedly jumping up and down or running long distances. Stress fractures can also arise from normal use of ...

  12. [Trochanteric femoral fractures].

    Science.gov (United States)

    Douša, P; Čech, O; Weissinger, M; Džupa, V

    2013-01-01

    , 31-A2) and intertrochanteric (31-A3) fractures is considered an important approach because of their different behaviour at reduction. Pertrochanteric fractures occurred more frequently (81.5%); the patients' age was higher (80 years on the average) and women outnumbered men at a ratio of 3:1. Intertrochanteric fractures were found in significantly younger patients (average, 72 years), with a women-to-men ratio of 1.3:1. Stable pertrochanteric fractures (31-A1) were preferably indicated for DHS surgery. Unstable pertrochanteric (31-A2) and intertrochanteric (31- A3) fractures were treated with a nail. The patients underwent surgery on the day of injury or the next day. In the case of contraindications to an urgent intervention, surgery was performed after the patient's medical condition had stabilised. The number of complications was largely related to technical errors, such as insufficient reduction or an incorrectly inserted implant. Intertrochanteric fractures were associated with a higher occurrence of complications. No implant can compensate for errors due to surgery. Serious complications can be reduced by the correct assessment of fracture type, the use of an appropriate operative technique and early treatment of potential complications. The necessity of restoring continuity in the medial cortex of the femoral neck (Adams' arch) is the requirement that should be observed. Pseudoarthrosis or varus malalignment in a healed hip should be managed by valgus osteotomy. When the femoral head or the acetabulum is damaged, total hip arthroplasty is indicated. A prerequisite for successful surgical outcome is urgently and correctly performed osteosynthesis allowing for early rehabilitation and mobilisation of the patient.

  13. High temperature fracture of ceramic materials

    International Nuclear Information System (INIS)

    Wiederhorn, S.M.

    1979-01-01

    A review is presented of fracture mechanisms and methods of lifetime prediction in ceramic materials. Techniques of lifetime prediction are based on the science of fracture mechanics. Application of these techniques to structural ceramics is limited by our incomplete understanding of fracture mechanisms in these materials, and by the occurrence of flaw generation in these materials at elevated temperatures. Research on flaw generation and fracture mechanisms is recommended as a way of improving the reliability of structural ceramics

  14. Distinguishing stress fractures from pathologic fractures: a multimodality approach

    International Nuclear Information System (INIS)

    Fayad, Laura M.; Kamel, Ihab R.; Kawamoto, Satomi; Bluemke, David A.; Fishman, Elliot K.; Frassica, Frank J.

    2005-01-01

    Whereas stress fractures occur in normal or metabolically weakened bones, pathologic fractures occur at the site of a bone tumor. Unfortunately, stress fractures may share imaging features with pathologic fractures on plain radiography, and therefore other modalities are commonly utilized to distinguish these entities. Additional cross-sectional imaging with CT or MRI as well as scintigraphy and PET scanning is often performed for further evaluation. For the detailed assessment of a fracture site, CT offers a high-resolution view of the bone cortex and periosteum which aids the diagnosis of a pathologic fracture. The character of underlying bone marrow patterns of destruction can also be ascertained along with evidence of a soft tissue mass. MRI, however, is a more sensitive technique for the detection of underlying bone marrow lesions at a fracture site. In addition, the surrounding soft tissues, including possible involvement of adjacent muscle, can be well evaluated with MRI. While bone scintigraphy and FDG-PET are not specific, they offer a whole-body screen for metastases in the case of a suspected malignant pathologic fracture. In this review, we present select examples of fractures that underscore imaging features that help distinguish stress fractures from pathologic fractures, since accurate differentiation of these entities is paramount. (orig.)

  15. Emergency department management of pain and anxiety related to orthopedic fracture care: a guide to analgesic techniques and procedural sedation in children.

    Science.gov (United States)

    Kennedy, Robert M; Luhmann, Jan D; Luhmann, Scott J

    2004-01-01

    Orthopedic fractures and joint dislocations are among the most painful pediatric emergencies. Safe and effective management of fracture-related pain and anxiety in the emergency department reduces patient distress during initial evaluation and often allows definitive management of the fracture. No consensus exists on which pharmacologic regimens for procedural sedation/analgesia are safest and most effective. For some children, control of fracture pain is the primary goal, whereas for others, relief from anxiety is an additionally important objective. Furthermore, strategies for the management of fracture pain may vary by fracture location and patient characteristics; thus, no single regimen is likely to provide the best means of analgesia and anxiolysis for all patients. Effective analgesia can be provided by local or regional anesthesia, such as hematoma, Bier, or nerve blocks. Alternatively, induction of deep sedation with analgesic agents such as ketamine or fentanyl, often combined with sedative-anxiolytic agents such as midazolam, may be used to manage distress associated with fracture reduction. A combination of local anesthesia with moderate sedation, for example nitrous oxide, is another attractive option.

  16. Principle and geomorphological applicability of summit level and base level technique using Aster Gdem satellite-derived data and the original software Baz

    Directory of Open Access Journals (Sweden)

    Akihisa Motoki

    2015-05-01

    Full Text Available This article presents principle and geomorphological applicability of summit level technique using Aster Gdem satellite-derived topographicdata. Summit level corresponds to thevirtualtopographic surface constituted bylocalhighest points, such as peaks and plateau tops, and reconstitutes palaeo-geomorphology before the drainage erosion. Summit level map is efficient for reconstitution of palaeo-surfaces and detection of active tectonic movement. Base level is thevirtualsurface composed oflocallowest points, as valley bottoms. The difference between summit level and base level is called relief amount. Thesevirtualmapsareconstructed by theoriginalsoftwareBaz. Themacroconcavity index, MCI, is calculated from summit level and relief amount maps. The volume-normalised three-dimensional concavity index, TCI, is calculated from hypsometric diagram. The massifs with high erosive resistance tend to have convex general form and low MCI and TCI. Those with low resistance have concave form and high MCI and TCI. The diagram of TCI vs. MCI permits to distinguish erosive characteristics of massifs according to their constituent rocks. The base level map for ocean bottom detects the basement tectonic uplift which occurred before the formation of the volcanic seamounts.

  17. Acetabular Fracture

    Directory of Open Access Journals (Sweden)

    Chad Correa

    2017-09-01

    Full Text Available History of present illness: A 77-year-old female presented to her primary care physician (PCP with right hip pain after a mechanical fall. She did not lose consciousness or have any other traumatic injuries. She was unable to ambulate post-fall, so X-rays were ordered by her PCP. Her X-rays were concerning for a right acetabular fracture (see purple arrows, so the patient was referred to the emergency department where a computed tomography (CT scan was ordered. Significant findings: The non-contrast CT images show a minimally displaced comminuted fracture of the right acetabulum involving the acetabular roof, medial and anterior walls (red arrows, with associated obturator muscle hematoma (blue oval. Discussion: Acetabular fractures are quite rare. There are 37 pelvic fractures per 100,000 people in the United States annually, and only 10% of these involve the acetabulum. They occur more frequently in the elderly totaling an estimated 4,000 per year. High-energy trauma is the primary cause of acetabular fractures in younger individuals and these fractures are commonly associated with other fractures and pelvic ring disruptions. Fractures secondary to moderate or minimal trauma are increasingly of concern in patients of advanced age.1 Classification of acetabular fractures can be challenging. However, the approach can be simplified by remembering the three basic types of acetabular fractures (column, transverse, and wall and their corresponding radiologic views. First, column fractures should be evaluated with coronally oriented CT images. This type of fracture demonstrates a coronal fracture line running caudad to craniad, essentially breaking the acetabulum into two halves: a front half and a back half. Secondly, transverse fractures should be evaluated by sagittally oriented CT images. By definition, a transverse fracture separates the acetabulum into superior and inferior halves with the fracture line extending from anterior to posterior

  18. Stress fractures in athletes

    International Nuclear Information System (INIS)

    Kirschberger, R.; Henning, A.; Graff, K.H.

    1984-01-01

    The early exclusion of the presence of a stress fracture may be decisive for the success of an athlete. Scintigraphy with a bone-seeking radiopharmaceutical is suitable for the early detection of stress lesions. Of 30 athletes, fractures were demonstrated in 17 whereas in 6 they were excluded. We found most fractures in the tarsal bones such as os naviculare pedis, ossa cuneiformia and talus. The type of sport engaged in appears to be an important factor in determining the location of the fracture. Scintiphotos were taken in several views using region of interest techniques and two phase-scintigraphy. This method is considered to be useful for localization and follow-up of skeletal stress lesions as well as for differential diagnosis. (orig.) [de

  19. Stress fractures in athletes

    Energy Technology Data Exchange (ETDEWEB)

    Kirschberger, R; Henning, A; Graff, K H

    1984-12-01

    The early exclusion of the presence of a stress fracture may be decisive for the success of an athlete. Scintigraphy with a bone-seeking radiopharmaceutical is suitable for the early detection of stress lesions. Of 30 athletes, fractures were demonstrated in 17 whereas in 6 they were excluded. We found most fractures in the tarsal bones such as os naviculare pedis, ossa cuneiformia and talus. The type of sport engaged in appears to be an important factor in determining the location of the fracture. Scintiphotos were taken in several views using region of interest techniques and two phase-scintigraphy. This method is considered to be useful for localization and follow-up of skeletal stress lesions as well as for differential diagnosis.

  20. On the Processing of Spalling Experiments. Part II: Identification of Concrete Fracture Energy in Dynamic Tension

    Science.gov (United States)

    Lukić, Bratislav B.; Saletti, Dominique; Forquin, Pascal

    2017-12-01

    This paper presents a second part of the study aimed at investigating the fracture behavior of concrete under high strain rate tensile loading. The experimental method together with the identified stress-strain response of three tests conducted on ordinary concrete have been presented in the paper entitled Part I (Forquin and Lukić in Journal of Dynamic Behavior of Materials, 2017. https://doi.org/10.1007/s40870-017-0135-1). In the present paper, Part II, the investigation is extended towards directly determining the specific fracture energy of each observed fracture zone by visualizing the dynamic cracking process with a temporal resolution of 1 µs. Having access to temporal displacement fields of the sample surface, it is possible to identify the fracture opening displacement (FOD) and the fracture opening velocity of any principle (open) and secondary (closed) fracture at each measurement instance, that may or may not lead to complete physical failure of the sample. Finally, the local Stress-FOD curves were obtained for each observed fracture zone, opposed to previous works where indirect measurements were used. The obtained results indicated a much lower specific fracture energy compared to the results often found in the literature. Furthermore, numerical simulations were performed with a damage law to evaluate the validity of the proposed experimental data processing and compare it to the most often used one in the previous works. The results showed that the present method can reliably predict the specific fracture energy needed to open one macro-fracture and suggested that indirect measurement techniques can lead to an overestimate of specific fracture energy due to the stringent assumption of linear elasticity up-to the peak and the inability of having access to the real post-peak change of axial stress.

  1. Complications of ankle fracture in patients with diabetes.

    Science.gov (United States)

    Chaudhary, Saad B; Liporace, Frank A; Gandhi, Ankur; Donley, Brian G; Pinzur, Michael S; Lin, Sheldon S

    2008-03-01

    Ankle fractures in patients with diabetes mellitus have long been recognized as a challenge to practicing clinicians. Complications of impaired wound healing, infection, malunion, delayed union, nonunion, and Charcot arthropathy are prevalent in this patient population. Controversy exists as to whether diabetic ankle fractures are best treated noninvasively or by open reduction and internal fixation. Patients with diabetes are at significant risk for soft-tissue complications. In addition, diabetic ankle fractures heal, but significant delays in bone healing exist. Also, Charcot ankle arthropathy occurs more commonly in patients who were initially undiagnosed and had a delay in immobilization and in patients treated nonsurgically for displaced ankle fractures. Several techniques have been described to minimize complications associated with diabetic ankle fractures (eg, rigid external fixation, use of Kirschner wires or Steinmann pins to increase rigidity). Regardless of the specifics of treatment, adherence to the basic principles of preoperative planning, meticulous soft-tissue management, and attention to stable, rigid fixation with prolonged, protected immobilization are paramount in minimizing problems and yielding good functional outcomes.

  2. Growth Kinematics of Opening-Mode Fractures

    Science.gov (United States)

    Eichhubl, P.; Alzayer, Y.; Laubach, S.; Fall, A.

    2014-12-01

    Fracture aperture is a primary control on flow in fractured reservoirs of low matrix permeability including unconventional oil and gas reservoirs and most geothermal systems. Guided by principles of linear elastic fracture mechanics, fracture aperture is generally assumed to be a linear function of fracture length and elastic material properties. Natural opening-mode fractures with significant preserved aperture are observed in core and outcrop indicative of fracture opening strain accommodated by permanent solution-precipitation creep. Fracture opening may thus be decoupled from length growth if the material effectively weakens after initial elastic fracture growth by either non-elastic deformation processes or changes in elastic properties. To investigate the kinematics of fracture length and aperture growth, we reconstructed the opening history of three opening-mode fractures that are bridged by crack-seal quartz cement in Travis Peak Sandstone of the SFOT-1 well, East Texas. Similar crack-seal cement bridges had been interpreted to form by repeated incremental fracture opening and subsequent precipitation of quartz cement. We imaged crack-seal cement textures for bridges sampled at varying distance from the tips using scanning electron microscope cathodoluminescence, and determined the number and thickness of crack-seal cement increments as a function of position along the fracture length and height. Observed trends in increment number and thickness are consistent with an initial stage of fast fracture propagation relative to aperture growth, followed by a stage of slow propagation and pronounced aperture growth. Consistent with fluid inclusion observations indicative of fracture opening and propagation occurring over 30-40 m.y., we interpret the second phase of pronounced aperture growth to result from fracture opening strain accommodated by solution-precipitation creep and concurrent slow, possibly subcritical, fracture propagation. Similar deformation

  3. Facial Fractures.

    Science.gov (United States)

    Ghosh, Rajarshi; Gopalkrishnan, Kulandaswamy

    2018-06-01

    The aim of this study is to retrospectively analyze the incidence of facial fractures along with age, gender predilection, etiology, commonest site, associated dental injuries, and any complications of patients operated in Craniofacial Unit of SDM College of Dental Sciences and Hospital. This retrospective study was conducted at the Department of OMFS, SDM College of Dental Sciences, Dharwad from January 2003 to December 2013. Data were recorded for the cause of injury, age and gender distribution, frequency and type of injury, localization and frequency of soft tissue injuries, dentoalveolar trauma, facial bone fractures, complications, concomitant injuries, and different treatment protocols.All the data were analyzed using statistical analysis that is chi-squared test. A total of 1146 patients reported at our unit with facial fractures during these 10 years. Males accounted for a higher frequency of facial fractures (88.8%). Mandible was the commonest bone to be fractured among all the facial bones (71.2%). Maxillary central incisors were the most common teeth to be injured (33.8%) and avulsion was the most common type of injury (44.6%). Commonest postoperative complication was plate infection (11%) leading to plate removal. Other injuries associated with facial fractures were rib fractures, head injuries, upper and lower limb fractures, etc., among these rib fractures were seen most frequently (21.6%). This study was performed to compare the different etiologic factors leading to diverse facial fracture patterns. By statistical analysis of this record the authors come to know about the relationship of facial fractures with gender, age, associated comorbidities, etc.

  4. [Periprosthetic knee fractures].

    Science.gov (United States)

    Mittlmeier, T; Beck, M; Bosch, U; Wichelhaus, A

    2016-01-01

    The cumulative incidence of periprosthetic fractures around the knee is increasing further because of an extended indication for knee replacement, previous revision arthroplasty, rising life expectancy and comorbidities. The relevance of local parameters such as malalignment, osseous defects, neighbouring implants, aseptic loosening and low-grade infections may sometimes be hidden behind the manifestation of a traumatic fracture. A differentiated diagnostic approach before the treatment of a periprosthetic fracture is of paramount importance, while the physician in-charge should also have particular expertise in fracture treatment and in advanced techniques of revision endoprosthetics. The following work gives an overview of this topic. Valid classifications are available for categorising periprosthetic fractures of the femur, the tibia and the patella respectively, which are helpful for the selection of treatment. With the wide-ranging modern treatment portfolio bearing in mind the substantial rate of complications and the heterogeneous functional outcome, the adequate analysis of fracture aetiology and the corresponding transformation into an individualised treatment concept offer the chance of an acceptable functional restoration of the patient at early full weight-bearing and prolonged implant survival. The management of complications is crucial to the final outcome.

  5. Dynamic Response in Transient Stress-Field Behavior Induced by Hydraulic Fracturing

    Science.gov (United States)

    Jenkins, Andrew

    Hydraulic fracturing is a technique which is used to exploit geologic features and subsurface properties in an effort to increase production in low-permeability formations. The process of hydraulic fracturing provides a greater surface contact area between the producing formation and the wellbore and thus increases the amount of recoverable hydrocarbons from within the reservoir. The use of this stimulation technique has brought on massive applause from the industry due to its widespread success and effectiveness, however the dynamic processes that take part in the development of hydraulic fractures is a relatively new area of research with respect to the massive scale operations that are seen today. The process of hydraulic fracturing relies upon understanding and exploiting the in-situ stress distribution throughout the area of study. These in-situ stress conditions are responsible for directing fracture orientation and propagation paths throughout the period of injection. The relative magnitude of these principle stresses is key in developing a successful stimulation plan. In horizontal well plan development the interpretation of stress within the reservoir is required for determining the azimuth of the horizontal well path. These horizontal laterals are typically oriented in a manner such that the well path lies parallel to the minimum horizontal stress. This allows for vertical fractures to develop transversely to the wellbore, or normal to the least principle stress without the theoretical possibility of fractures overlapping, creating the most efficient use of the fluid energy during injection. The orientation and magnitude of these in-situ stress fields however can be dynamic, controlled by the subsequent fracture propagation and redistribution of the surrounding stresses. That is, that as the fracture propagates throughout the reservoir, the relative stress fields surrounding the fractures may see a shift and deviate from their original direction or

  6. Fracture sacrum.

    Directory of Open Access Journals (Sweden)

    Dogra A

    1995-04-01

    Full Text Available An extremely rare case of combined transverse and vertical fracture of sacrum with neurological deficit is reported here with a six month follow-up. The patient also had an L1 compression fracture. The patient has recovered significantly with conservative management.

  7. Fracture Mechanics

    CERN Document Server

    Zehnder, Alan T

    2012-01-01

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

  8. Titanium elastic nailing in pediatric femoral diaphyseal fractures

    Directory of Open Access Journals (Sweden)

    Singh Roop

    2006-01-01

    Full Text Available Background: The need for operative fixation of pediatric femoral fractures is increasingly being recognised in the present decade. The conventional traction and casting method for management of pediatric femoral fractures is giving way for the operative stabilisation of the fracture. Methods : Thirty five pediatric patients in age group 6-14 years with diaphyseal femoral fractures were stabilised with two titanium nails. Patients were followed up clinically and radiologically for two years. The final results were evaluated using the criteria of Flynn et al. Technical problems and complications associated with the procedure were also analysed. Results : Overall results observed were excellent in 25, satisfactory in 8 and poor in 2 patients. Hospital time averaged 12.30 days in the series. All the fractures healed with an average time to union of 9.6 (6-14.4 weeks. Return to school was early with an average of 7.8 weeks. The soft tissue discomfort near the knee produced by the nails ends was the most common problem encountered. Shortening was observed in three cases and restriction of knee flexion in 5 patients. There was no delayed union, infection or refractures. Per operative technical problems included failure of closed reduction in 2 cases and cork screwing of nails in one case. Conclusion : We believe that with proper operative technique and aftercare TENs may prove to be an ideal implant for pediatric femoral fracture fixation. The most of the complication associated with the procedure are infact features of inexact technique and can be eliminated by strictly adhering to the basic principles and technical aspects.

  9. A STUDY ON THE MANAGEMENT OF DISPLACED FRACTURES OF PATELLA USING MODIFIED TENSION BAND WIRING

    Directory of Open Access Journals (Sweden)

    Hari Babu

    2015-10-01

    Full Text Available INTRODUCTION: Patella is an important component of the extensor mechanism of the knee. A patella fracture constitutes 1% of all skeletal fractures resulting from either direct or indirect trauma. Any improper and inadequate treatment would inevitably lead to a disability which would be most perceptibly felt in a country like India, where squatting is important activity in daily life. The goal of treatment is to regain the continuity of the extensor mechanism and congruity of patellofemoral a rticulation so that the normal function of the knee can be restored. Several techniques have been described for internal fixation of fractures of patella. The ideal fixation for the fracture patella is that it should be strong enough to allow early mobiliz ation, reduce posttraumatic stiffness and perhaps help the healing of the articular surface . AIMS: To analyze the functional outcome of displaced transverse fractures of the patella treated by Modified Tension Band Wiring principle (Muller using A. Dutta & S. K. Gupta Scoring System. To extend the application of Modified Tension Band wiring for minimally comminuted fractures of patella and assesses the results. CONCLUSION : The present study shows that modified tension band wiring (Muller is an effective p rocedure in the management of displaced transverse patellar fractures, with excellent to good results. Minimally comminuted patellar fractures also yielded excellent to good results with Modified tension band wiring as an extended application. The results in the present study are comparable to other modifications of Tension Band Wiring principle. The surgery of Modified Tension Band Wiring gives rigid fixation and helps in early mobilization. Regular and scheduled post- operative physiotherapy plays an impor tant role in the functional outcome.

  10. Biomedical engineering principles

    CERN Document Server

    Ritter, Arthur B; Valdevit, Antonio; Ascione, Alfred N

    2011-01-01

    Introduction: Modeling of Physiological ProcessesCell Physiology and TransportPrinciples and Biomedical Applications of HemodynamicsA Systems Approach to PhysiologyThe Cardiovascular SystemBiomedical Signal ProcessingSignal Acquisition and ProcessingTechniques for Physiological Signal ProcessingExamples of Physiological Signal ProcessingPrinciples of BiomechanicsPractical Applications of BiomechanicsBiomaterialsPrinciples of Biomedical Capstone DesignUnmet Clinical NeedsEntrepreneurship: Reasons why Most Good Designs Never Get to MarketAn Engineering Solution in Search of a Biomedical Problem

  11. Circummandibular Wires for Treatment of Dentoalveolar Fractures Adjacent to Edentulous Areas: A Report of Two Cases.

    Science.gov (United States)

    Maloney, Karl

    2015-09-01

    In general, dentoalveolar fractures are a common injury seen in emergency departments, dental offices, and oral and maxillofacial surgery practices. These injuries can be the result of direct trauma or indirect trauma. Direct trauma more often causes trauma to the maxillary dentition due to the exposure of the maxillary anterior teeth. Indirect trauma is usually the result of forced occlusion secondary to a blow to the chin or from a whiplash injury. Falls are the most common mechanism of injury seen in the pediatric group. In adolescents, many of these fractures are sustained during sporting activities. However, the use of mouth guards and other protective equipment has decreased this number. Most adult injuries are caused by motor vehicle accidents, contact sports, falls, bicycles, interpersonal violence, medical/dental mishaps, and industrial accidents. Early intervention to reduce and stabilize the fracture is required to establish a bony union and ensure correct function. Most dentoalveolar fractures have bilateral stable adjacent dentition and are treated with a closed technique utilizing an acid-etch/resin splint followed by splint removal at 4 weeks. Other inferior stabilization treatments used are arch bars and other wiring techniques. It is widely accepted that semirigid stabilization techniques, such as an acid-etch/resin splint or wiring procedures, are adequate to treat dentoalveolar fractures. This is in contrast to the treatment of mandible fractures where AO principles of rigid fixation are often followed. Fractures that are unable to be reduced sometimes necessitate an open reduction followed by internal fixation, sometimes using a secondary splint for mobile teeth. In those rare cases when there are not stable adjacent teeth bilaterally other modalities must be considered. In the present report, two cases are presented where circummandibular wires were used to treat fractured mandibular dentoalveolar segments adjacent to edentulous areas.

  12. The limited anterior approach of the elbow for open reduction and internal fixation of capitellum fractures. Surgical technique and clinical experience in 2 cases with more than 2 years follow-up.

    Science.gov (United States)

    Ballesteros-Betancourt, J R; Fernández-Valencia, J A; García-Tarriño, R; Domingo-Trepat, A; Sastre-Solsona, S; Combalia-Aleu, A; Llusá-Pérez, M

    Fractures involving the capitellum can be treated surgically by excision of the fragment, or by reduction and internal fixation with screws, with or without heads. The lateral Kocher approach is the most common approach for open reduction. We believe that the limited anterior approach of the elbow, could be a valid technique for treating these fractures, as it does not involve the detachment of any muscle group or ligament, facilitating the recovery process. A description is presented of the surgical technique, as well as of 2cases with a Bryan-Morrey type 1 fracture (Dubberley type 1A). Two different final quality of life evaluation questionnaires were completed by telephone: the EuroQol Five Dimensions Questionnaire (EQ-5D), and the patient part of the Liverpool Elbow Score (PAQ-LES) questionnaire. The 2patients showed favourable clinical progress at 36 and 24 months, respectively, with an extension/flexion movement arc of -5°/145° and -10°/145°, as well as a pronosupination of 85°/80° and 90°/90°. The 2patients showed radiological consolidation with no signs of osteonecrosis. The EQ-5D score was 0.857 and 0.910 (range: 0.36-1), and a PAQ-SLE of 35 and 35 (range: 17-36), respectively. We believe that the limited anterior approach of the elbow is a technical option to consider for the open surgical treatment of a capitellum fracture, although further studies are needed to demonstrate its superiority and clinical safety compared to the classical lateral Kocher approach. Copyright © 2017 SECOT. Publicado por Elsevier España, S.L.U. All rights reserved.

  13. Elastic plastic fracture mechanics

    International Nuclear Information System (INIS)

    Simpson, L.A.

    1978-07-01

    The application of linear elastic fracture mechanics (LEFM) to crack stability in brittle structures is now well understood and widely applied. However, in many structural materials, crack propagation is accompanied by considerable crack-tip plasticity which invalidates the use of LEFM. Thus, present day research in fracture mechanics is aimed at developing parameters for predicting crack propagation under elastic-plastic conditions. These include critical crack-opening-displacement methods, the J integral and R-curve techniques. This report provides an introduction to these concepts and gives some examples of their applications. (author)

  14. Trans trochanteric approach with coronal osteotomy of the great trochanter: A new technique for extra-capsular trochanteric fracture patients treated by total hip arthroplasty (THA) in elderly.

    Science.gov (United States)

    Steffann, Francois; Prudhon, Jean-Louis; Puch, Jean-Marc; Ferreira, André; Descamps, Loys; Verdier, Régis; Caton, Jacques

    2015-06-05

    Several surgical approaches could be used in hip arthroplasty or trauma surgery: anterior, anterolateral, lateral, posterior (with or without trochanterotomy), using or not an orthopedic reduction table. Subtrochanteric and extra-capsular trochanteric fractures (ECTF) are usually treated by internal fixation with mandatory restrictions on weight bearing. Specific complications have been widely described. Mechanical failures are particularly high in unstable fractures. Hip fractures are a major public health issue with a mortality rate of 12%-23% at 1 year. An alternative option is to treat ECTF by total hip arthroplasty (THA) to prevent decubitus complications, to help rapid recovery, and to permit immediate weight bearing as well as quick rehabilitation. However, specific risks of THA have to be considered such as dislocation or cardiovascular failure. The classical approach (anterior or posterior) requires the opening of the joint and capsule, weakening hip stability and the repair of the great trochanter is sometimes hazardous. For 15 years, we have been treating unstable ECTF by THA with cementless stem, dual mobility cup (DMC), greater trochanter (GT) reattachment, and a new surgical approach preserving capsule, going through the fracture and avoiding joint dislocation. Bombaci first described a similar approach in 2008; our trans fractural digastric approach (medial gluteus and lateral vastus) is different. A coronal GT osteotomy is performed when there is no coronal fracture line. It allows easy access to the femoral neck and acetabulum. The THA is implanted without femoral internal rotation to avoid extra bone fragment displacement. With pre-operative planning, cup implantation is easy and stem positioning is adjusted referring to the top of the GT after trial reduction and preoperative planning. The longitudinal osteotomy and trochanteric fracture are repaired with wires and the digastric incision is closed. This variant of Bombaci approach could be use

  15. Correlation analysis of fracture arrangement in space

    Science.gov (United States)

    Marrett, Randall; Gale, Julia F. W.; Gómez, Leonel A.; Laubach, Stephen E.

    2018-03-01

    We present new techniques that overcome limitations of standard approaches to documenting spatial arrangement. The new techniques directly quantify spatial arrangement by normalizing to expected values for randomly arranged fractures. The techniques differ in terms of computational intensity, robustness of results, ability to detect anti-correlation, and use of fracture size data. Variation of spatial arrangement across a broad range of length scales facilitates distinguishing clustered and periodic arrangements-opposite forms of organization-from random arrangements. Moreover, self-organized arrangements can be distinguished from arrangements due to extrinsic organization. Traditional techniques for analysis of fracture spacing are hamstrung because they account neither for the sequence of fracture spacings nor for possible coordination between fracture size and position, attributes accounted for by our methods. All of the new techniques reveal fractal clustering in a test case of veins, or cement-filled opening-mode fractures, in Pennsylvanian Marble Falls Limestone. The observed arrangement is readily distinguishable from random and periodic arrangements. Comparison of results that account for fracture size with results that ignore fracture size demonstrates that spatial arrangement is dominated by the sequence of fracture spacings, rather than coordination of fracture size with position. Fracture size and position are not completely independent in this example, however, because large fractures are more clustered than small fractures. Both spatial and size organization of veins here probably emerged from fracture interaction during growth. The new approaches described here, along with freely available software to implement the techniques, can be applied with effect to a wide range of structures, or indeed many other phenomena such as drilling response, where spatial heterogeneity is an issue.

  16. Fractures of the shafts of the tibia and fibula

    International Nuclear Information System (INIS)

    Bender, C.E.; Campbell, D.C.

    1985-01-01

    Fractures of the shafts of the tibia and fibula are the most common long bone fractures. This chapter discusses tibial and fibular shaft fractures. Treatment of tibial and fibular fractures is similar and, therefore, reference is primarily made to the tibia. Diagnostic techniques are also evaluated

  17. Fracture mechanics

    CERN Document Server

    Perez, Nestor

    2017-01-01

    The second edition of this textbook includes a refined presentation of concepts in each chapter, additional examples; new problems and sections, such as conformal mapping and mechanical behavior of wood; while retaining all the features of the original book. The material included in this book is based upon the development of analytical and numerical procedures pertinent to particular fields of linear elastic fracture mechanics (LEFM) and plastic fracture mechanics (PFM), including mixed-mode-loading interaction. The mathematical approach undertaken herein is coupled with a brief review of several fracture theories available in cited references, along with many color images and figures. Dynamic fracture mechanics is included through the field of fatigue and Charpy impact testing. Explains computational and engineering approaches for solving crack-related problems using straightforward mathematics that facilitate comprehension of the physical meaning of crack growth processes; Expands computational understandin...

  18. Fracture analysis

    International Nuclear Information System (INIS)

    Ueng, Tzoushin; Towse, D.

    1991-01-01

    Fractures are not only the weak planes of a rock mass, but also the easy passages for the fluid flow. Their spacing, orientation, and aperture will affect the deformability, strength, heat transmittal, and fluid transporting properties of the rock mass. To understand the thermomechanical and hydrological behaviors of the rock surrounding the heater emplacement borehole, the location, orientation, and aperture of the fractures of the rock mass should be known. Borehole television and borescope surveys were performed to map the location, orientation, and aperture of the fractures intersecting the boreholes drilled in the Prototype Engineered Barrier System Field Tests (PEBSFT) at G-Tunnel. Core logging was also performed during drilling. However, because the core was not oriented and the depth of the fracture cannot be accurately determined, the results of the core logging were only used as reference and will not be discussed here

  19. Facial Fractures.

    Science.gov (United States)

    Ricketts, Sophie; Gill, Hameet S; Fialkov, Jeffery A; Matic, Damir B; Antonyshyn, Oleh M

    2016-02-01

    After reading this article, the participant should be able to: 1. Demonstrate an understanding of some of the changes in aspects of facial fracture management. 2. Assess a patient presenting with facial fractures. 3. Understand indications and timing of surgery. 4. Recognize exposures of the craniomaxillofacial skeleton. 5. Identify methods for repair of typical facial fracture patterns. 6. Discuss the common complications seen with facial fractures. Restoration of the facial skeleton and associated soft tissues after trauma involves accurate clinical and radiologic assessment to effectively plan a management approach for these injuries. When surgical intervention is necessary, timing, exposure, sequencing, and execution of repair are all integral to achieving the best long-term outcomes for these patients.

  20. Pisiform fractures

    International Nuclear Information System (INIS)

    Fleege, M.A.; Jebson, P.J.; Renfrew, D.L.; El-Khoury, G.Y.; Steyers, C.M. Jr.

    1991-01-01

    Fractures of the pisiform are often missed due to improper radiographic evaluation and a tendency to focus on other, more obvious injuries. Delayed diagnosis may result in disabling sequelae. A high index of clinical suspicion and appropriate radiographic examination will establish the correct diagnosis. Ten patients with pisiform fracture are presented. The anatomy, mechanism of injury, clinical presentation, radiographic features, and evaluation of this injury are discussed. (orig.)

  1. Probabilistic finite elements for fatigue and fracture analysis

    Science.gov (United States)

    Belytschko, Ted; Liu, Wing Kam

    1993-04-01

    An overview of the probabilistic finite element method (PFEM) developed by the authors and their colleagues in recent years is presented. The primary focus is placed on the development of PFEM for both structural mechanics problems and fracture mechanics problems. The perturbation techniques are used as major tools for the analytical derivation. The following topics are covered: (1) representation and discretization of random fields; (2) development of PFEM for the general linear transient problem and nonlinear elasticity using Hu-Washizu variational principle; (3) computational aspects; (4) discussions of the application of PFEM to the reliability analysis of both brittle fracture and fatigue; and (5) a stochastic computational tool based on stochastic boundary element (SBEM). Results are obtained for the reliability index and corresponding probability of failure for: (1) fatigue crack growth; (2) defect geometry; (3) fatigue parameters; and (4) applied loads. These results show that initial defect is a critical parameter.

  2. Stress fractures in athletes

    International Nuclear Information System (INIS)

    Steingruber, I.E.; Wolf, C.; Gruber, H.; Czermak, B.V.; Mallouhi, A.; Jaschke, W.; Gabriel, M.

    2002-01-01

    Stress fractures may pose a diagnostic dilemma for radiologists since they are sometimes difficult to demonstrate on plain films and may simulate a tumour. They were first described in military personnel and professional athletes. Recently, there is an increasing incidence in the general population due to increasing sportive activities. Stress fractures occur most often in the lower extremities, especially in the tibia, the tarsal bone, the metatarsal bone, the femur and the fibula. In the upper extremities, they are commonly found in the humerus, the radius and the ulna. Some fractures of the lower extremities appear to be specific for particular sports, for example, fractures of the tibia affect mostly distance runners. Whereas stress fractures of the upper extremities are generally associated with upper limb-dominated sports. A correct diagnosis requires a careful clinical evaluation. The initial plain radiography may be normal. Further radiological evaluation could be performed by means of computerised tomography, magnetic resonance imaging and bone scanning. The latter two techniques are especially helpful for establishing a correct initial diagnosis. (orig.) [de

  3. An Embedded 3D Fracture Modeling Approach for Simulating Fracture-Dominated Fluid Flow and Heat Transfer in Geothermal Reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Johnston, Henry [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Wang, Cong [Colorado School of Mines; Winterfeld, Philip [Colorado School of Mines; Wu, Yu-Shu [Colorado School of Mines

    2018-02-14

    An efficient modeling approach is described for incorporating arbitrary 3D, discrete fractures, such as hydraulic fractures or faults, into modeling fracture-dominated fluid flow and heat transfer in fractured geothermal reservoirs. This technique allows 3D discrete fractures to be discretized independently from surrounding rock volume and inserted explicitly into a primary fracture/matrix grid, generated without including 3D discrete fractures in prior. An effective computational algorithm is developed to discretize these 3D discrete fractures and construct local connections between 3D fractures and fracture/matrix grid blocks of representing the surrounding rock volume. The constructed gridding information on 3D fractures is then added to the primary grid. This embedded fracture modeling approach can be directly implemented into a developed geothermal reservoir simulator via the integral finite difference (IFD) method or with TOUGH2 technology This embedded fracture modeling approach is very promising and computationally efficient to handle realistic 3D discrete fractures with complicated geometries, connections, and spatial distributions. Compared with other fracture modeling approaches, it avoids cumbersome 3D unstructured, local refining procedures, and increases computational efficiency by simplifying Jacobian matrix size and sparsity, while keeps sufficient accuracy. Several numeral simulations are present to demonstrate the utility and robustness of the proposed technique. Our numerical experiments show that this approach captures all the key patterns about fluid flow and heat transfer dominated by fractures in these cases. Thus, this approach is readily available to simulation of fractured geothermal reservoirs with both artificial and natural fractures.

  4. Jogger's fracture and other stress fractures of the lumbo-sacral spine

    International Nuclear Information System (INIS)

    Abel, M.S.

    1985-01-01

    The posterior rings of the lower lumbo-sacral vertebrae are subject to stress fractures at any part - pedicle, pars, or lamina. The site of fracture is apparently determined by the axis of weight bearing. The three illustrative clinical examples cited include a jogger with a laminar fracture, a ballet dancer with pedicle fractures, and a nine-year-old boy with fractures of pars and lamina. Chronic low back pain is the typical complaint with stress fractures of the lower lumbo-sacral spine. Special imaging techniques are usually needed to demonstrate these lesions, including vertebral arch views, multi-directional tomography, and computed tomography (CT). (orig.)

  5. Scaphoid Fracture

    Directory of Open Access Journals (Sweden)

    Esther Kim, BS

    2018-04-01

    Full Text Available History of present illness: A 25-year-old, right-handed male presented to the emergency department with left wrist pain after falling from a skateboard onto an outstretched hand two-weeks prior. He otherwise had no additional concerns, including no complaints of weakness or loss of sensation. On physical exam, there was tenderness to palpation within the anatomical snuff box. The neurovascular exam was intact. Plain films of the left wrist and hand were obtained. Significant findings: The anteroposterior (AP plain film of this patient demonstrates a full thickness fracture through the middle third of the scaphoid (red arrow, with some apparent displacement (yellow lines and subtle angulation of the fracture fragments (blue line. Discussion: The scaphoid bone is the most commonly fractured carpal bone accounting for 70%-80% of carpal fractures.1 Classically, it is sustained following a fall onto an outstretched hand (FOOSH. Patients should be evaluated for tenderness with palpation over the anatomical snuffbox, which has a sensitivity of 100% and specificity of 40%.2 Plain films are the initial diagnostic modality of choice and have a sensitivity of 70%, but are commonly falsely negative in the first two to six weeks of injury (false negative of 20%.3 The Mayo classification organizes scaphoid fractures as involving the proximal, mid, and distal portions of the scaphoid bone with mid-fractures being the most common.3 The proximal scaphoid is highly susceptible to vascular compromise because it depends on retrograde blood flow from the radial artery. Therefore, disruption can lead to serious sequelae including osteonecrosis, arthrosis, and functional impairment. Thus, a low threshold should be maintained for neurovascular evaluation and surgical referral. Patients with non-displaced scaphoid fractures should be placed in a thumb spica splint.3 Patients with even suspected scaphoid fractures should be placed in a thumb spica splint and re

  6. Subtrochanteric Femoral Fracture during Trochanteric Nailing for the Treatment of Femoral Shaft Fracture

    OpenAIRE

    Yun, Ho Hyun; Oh, Chi Hun; Yi, Ju Won

    2013-01-01

    We report on three cases of subtrochanteric femoral fractures during trochanteric intramedullary nailing for the treatment of femoral shaft fractures. Trochanteric intramedullary nails, which have a proximal lateral bend, are specifically designed for trochanteric insertion. When combined with the modified insertion technique, trochanteric intramedullary nails reduce iatrogenic fracture comminution and varus malalignment. We herein describe technical aspects of trochanteric intramedullary nai...

  7. Sealing of rock fractures

    International Nuclear Information System (INIS)

    Pusch, R.; Erlstroem, M.; Boergesson, L.

    1985-12-01

    The major water-bearing fractures in granite usually from fairly regular sets but the extension and degree of connectivity is varying. This means that only a few fractures that are interconnected with the deposition holes and larger water-bearing structures in a HLW repository are expected and if they can be identified and cut off through sealing it would be possible to improve the isolation of waste packages very effectively. Nature's own fracture sealing mechanisms may be simulated and a survey of the involved processes actually suggests a number of possible filling methods and substances. Most of them require high temperature and pressure and correspondingly sophisticated techniques, but some are of potential interest for immediate application with rather moderate effort. Such a technique is to fill the fractures with clayey substances which stay flexible and low-permeable provided that they remain physically and chemically intact. It is demonstrated in the report that effective grouting requires a very low viscosity and shear strength of the substance and this can be achieved by mechanical agitation as demonstrated in this report. Thus, by superimposing static pressure and shear waves induced by percussion hammering at a suitable frequency, clays and fine-grained silts as well as cement can be driven into fractures with an average aperture as small as 0.1 mm. Experiments were made in the laboratory using concrete and steel plates, and a field pilot test was also conducted under realistic conditions on site in Stripa. They all demonstrated the practicality of the 'dynamic injection technique' and that the fluid condition of the grouts yielded complete filling of the injected space to a considerable distance from the injection point. The field test indicated a good sealing ability as well as a surprisingly high resistance to erosion and piping. (author)

  8. First-principles studies on vacancy-modified interstitial diffusion mechanism of oxygen in nickel, associated with large-scale atomic simulation techniques

    International Nuclear Information System (INIS)

    Fang, H. Z.; Shang, S. L.; Wang, Y.; Liu, Z. K.; Alfonso, D.; Alman, D. E.; Shin, Y. K.; Zou, C. Y.; Duin, A. C. T. van; Lei, Y. K.; Wang, G. F.

    2014-01-01

    This paper is concerned with the prediction of oxygen diffusivities in fcc nickel from first-principles calculations and large-scale atomic simulations. Considering only the interstitial octahedral to tetrahedral to octahedral minimum energy pathway for oxygen diffusion in fcc lattice, greatly underestimates the migration barrier and overestimates the diffusivities by several orders of magnitude. The results indicate that vacancies in the Ni-lattice significantly impact the migration barrier of oxygen in nickel. Incorporation of the effect of vacancies results in predicted diffusivities consistent with available experimental data. First-principles calculations show that at high temperatures the vacancy concentration is comparable to the oxygen solubility, and there is a strong binding energy and a redistribution of charge density between the oxygen atom and vacancy. Consequently, there is a strong attraction between the oxygen and vacancy in the Ni lattice, which impacts diffusion

  9. Subtrochanteric femoral fracture during trochanteric nailing for the treatment of femoral shaft fracture.

    Science.gov (United States)

    Yun, Ho Hyun; Oh, Chi Hun; Yi, Ju Won

    2013-09-01

    We report on three cases of subtrochanteric femoral fractures during trochanteric intramedullary nailing for the treatment of femoral shaft fractures. Trochanteric intramedullary nails, which have a proximal lateral bend, are specifically designed for trochanteric insertion. When combined with the modified insertion technique, trochanteric intramedullary nails reduce iatrogenic fracture comminution and varus malalignment. We herein describe technical aspects of trochanteric intramedullary nailing for femoral shaft fractures to improve its application and prevent implant-derived complications.

  10. Current Concepts in the Mandibular Condyle Fracture Management Part I: Overview of Condylar Fracture

    OpenAIRE

    Choi, Kang-Young; Yang, Jung-Dug; Chung, Ho-Yun; Cho, Byung-Chae

    2012-01-01

    The incidence of condylar fractures is high, but the management of fractures of the mandibular condyle continues to be controversial. Historically, maxillomandibular fixation, external fixation, and surgical splints with internal fixation systems were the techniques commonly used in the treatment of the fractured mandible. Condylar fractures can be extracapsular or intracapsular, undisplaced, deviated, displaced, or dislocated. Treatment depends on the age of the patient, the co-existence of ...

  11. Use of Cutting-Edge Horizontal and Underbalanced Drilling Technologies and Subsurface Seismic Techniques to Explore, Drill and Produce Reservoired Oil and Gas from the Fractured Monterey Below 10,000 ft in the Santa Maria Basin of California

    Energy Technology Data Exchange (ETDEWEB)

    George Witter; Robert Knoll; William Rehm; Thomas Williams

    2006-06-30

    This project was undertaken to demonstrate that oil and gas can be drilled and produced safely and economically from a fractured Monterey reservoir in the Santa Maria Basin of California by employing horizontal wellbores and underbalanced drilling technologies. Two vertical wells were previously drilled in this area with heavy mud and conventional completions; neither was commercially productive. A new well was drilled by the project team in 2004 with the objective of accessing an extended length of oil-bearing, high-resistivity Monterey shale via a horizontal wellbore, while implementing managed-pressure drilling (MPD) techniques to avoid formation damage. Initial project meetings were conducted in October 2003. The team confirmed that the demonstration well would be completed open-hole to minimize productivity impairment. Following an overview of the geologic setting and local field experience, critical aspects of the application were identified. At the pre-spud meeting in January 2004, the final well design was confirmed and the well programming/service company requirements assigned. Various design elements were reduced in scope due to significant budgetary constraints. Major alterations to the original plan included: (1) a VSP seismic survey was delayed to a later phase; (2) a new (larger) surface hole would be drilled rather than re-enter an existing well; (3) a 7-in. liner would be placed into the top of the Monterey target as quickly as possible to avoid problems with hole stability; (4) evaluation activities were reduced in scope; (5) geosteering observations for fracture access would be deduced from penetration rate, cuttings description and hydrocarbon in-flow; and (6) rather than use nitrogen, a novel air-injection MPD system was to be implemented. Drilling operations, delayed from the original schedule by capital constraints and lack of rig availability, were conducted from September 12 to November 11, 2004. The vertical and upper curved sections were

  12. [Distal clavicle fracture].

    Science.gov (United States)

    Seppel, G; Lenich, A; Imhoff, A B

    2014-06-01

    Reposition and fixation of unstable distal clavicle fractures with a low profile locking plate (Acumed, Hempshire, UK) in conjunction with a button/suture augmentation cerclage (DogBone/FibreTape, Arthrex, Naples, FL, USA). Unstable fractures of the distal clavicle (Jäger and Breitner IIA) in adults. Unstable fractures of the distal clavicle (Jäger and Breitner IV) in children. Distal clavicle fractures (Jäger and Breitner I, IIB or III) with marked dislocation, injury of nerves and vessels, or high functional demand. Patients in poor general condition. Fractures of the distal clavicle (Jäger and Breitner I, IIB or III) without marked dislocation or vertical instability. Local soft-tissue infection. Combination procedure: Initially the lateral part of the clavicle is exposed by a 4 cm skin incision. After reduction of the fracture, stabilization is performed with a low profile locking distal clavicle plate. Using a special guiding device, a transclavicular-transcoracoidal hole is drilled under arthroscopic view. Additional vertical stabilization is arthroscopically achieved by shuttling the DogBone/FibreTape cerclage from the lateral portal cranially through the clavicular plate. The two ends of the FibreTape cerclage are brought cranially via adjacent holes of the locking plate while the DogBone button is placed under the coracoid process. Thus, plate bridging is achieved. Finally reduction is performed and the cerclage is secured by surgical knotting. Use of an arm sling for 6 weeks. Due to the fact that the described technique is a relatively new procedure, long-term results are lacking. In the short term, patients postoperatively report high subjective satisfaction without persistent pain.

  13. Contemporary management of subtrochanteric fractures.

    Science.gov (United States)

    Joglekar, Siddharth B; Lindvall, Eric M; Martirosian, Armen

    2015-01-01

    Cephalomedullary interlocking nails that allow for trochanteric entry and minimally invasive fixation have revolutionized the contemporary management of subtrochanteric fractures with improved union rates and decreased incidence of fixation failure. The most successful alternative to intramedullary fixation remains the angled blade plate. Despite biomechanical superiority of contemporary intramedullary implants to previous intramedullary devices, the importance of achieving and maintaining satisfactory fracture reduction prior to and during hardware insertion cannot be overemphasized. In comminuted and more challenging fractures, additional techniques, such as limited open reduction with clamps and/or cables, can allow for canal restoration and more anatomic reductions prior to and/or during nail insertion. Published by Elsevier Inc.

  14. Pelvic and acetabular fractures

    International Nuclear Information System (INIS)

    Mears, D.C.; Rubash, H.E.

    1986-01-01

    This treatise focuses primarily on the clinical aspects of diagnosis and treatments of pelvic and acetabular fractures. However, considerable attention is also paid to the radiographic diagnosis of trauma and postoperative effects. The book begins with a succinct review of pelvic and acetabular anatomy and pelvic biomechanics. It continues with a radiographic classification of pelvic injury, which will represent the major source of the book's interest for radiologists. The remainder of the book is concerned with clinical management of pelvic and acetabular trauma, including preoperative planning, surgical approaches, techniques of reduction, internal fixation, eternal fixation, post-operative care, and late problems. Even throughout this later portion of the book there are extensive illustrations, including plain radiographs, computed tomographic (CT) scans, reconstructed three-dimensional CT scans, and schematic diagrams of diverse pelvic and acetabular fractures and the elementary surgical techniques for their repair

  15. Integration of different data gap filling techniques to facilitate assessment of polychlorinated biphenyls: A proof of principle case study (ASCCT meeting)

    Science.gov (United States)

    Data gap filling techniques are commonly used to predict hazard in the absence of empirical data. The most established techniques are read-across, trend analysis and quantitative structure-activity relationships (QSARs). Toxic equivalency factors (TEFs) are less frequently used d...

  16. Variational principles

    CERN Document Server

    Moiseiwitsch, B L

    2004-01-01

    This graduate-level text's primary objective is to demonstrate the expression of the equations of the various branches of mathematical physics in the succinct and elegant form of variational principles (and thereby illuminate their interrelationship). Its related intentions are to show how variational principles may be employed to determine the discrete eigenvalues for stationary state problems and to illustrate how to find the values of quantities (such as the phase shifts) that arise in the theory of scattering. Chapter-by-chapter treatment consists of analytical dynamics; optics, wave mecha

  17. Trochanteric fractures

    International Nuclear Information System (INIS)

    Herrlin, K.; Stroemberg, T.; Lidgren, L.; Walloee, A.; Pettersson, H.; Lund Univ.

    1988-01-01

    Four hundred and thirty trochanteric factures operated upon with McLaughlin, Ender or Richard's osteosynthesis were divided into 6 different types based on their radiographic appearance before and immediately after reposition with special reference to the medial cortical support. A significant correlation was found between the fracture type and subsequent mechanical complications where types 1 and 2 gave less, and types 4 and 5 more complications. A comparison of the various osteosyntheses showed that Richard's had significantly fewer complications than either the Ender or McLaughlin types. For Richard's osteosynthesis alone no correlation to fracture type could be made because of the small number of complications in this group. (orig.)

  18. Fracture Blisters

    Directory of Open Access Journals (Sweden)

    Uebbing, Claire M

    2011-02-01

    Full Text Available Fracture blisters are a relatively uncommon complication of fractures in locations of the body, such as the ankle, wrist elbow and foot, where skin adheres tightly to bone with little subcutaneous fat cushioning. The blister that results resembles that of a second degree burn.These blisters significantly alter treatment, making it difficult to splint or cast and often overlying ideal surgical incision sites. Review of the literature reveals no consensus on management; however, most authors agree on early treatment prior to blister formation or delay until blister resolution before attempting surgical correction or stabilization. [West J Emerg Med. 2011;12(1;131-133.

  19. Humeral Shaft Fracture: Intramedullary Nailing.

    Science.gov (United States)

    Konda, Sanjit R; Saleh, Hesham; Fisher, Nina; Egol, Kenneth A

    2017-08-01

    This video demonstrates the technique of intramedullary nailing for a humeral shaft fracture. The patient is a 30-year-old man who sustained a gunshot wound to his right arm. The patient was indicated for humeral nailing given the comminuted nature of the diaphysis and to allow for minimal skin incisions. Other relative indications include soft-tissue compromise about the arm precluding a large surgical exposure. This video presents a case of a comminuted humeral shaft fracture treated with an intramedullary nail. Anatomic reduction and stable fixation was obtained with this technique. This case demonstrates a soft-tissue sparing technique of humeral shaft fixation using a humeral intramedullary nail. The technique is easy to perform and has significant benefits in minimizing surgical exposure, decreasing operative time, and decreasing blood loss. In the correct clinical setting, humeral nailing provides an expeditious form of fixation that restores length, alignment, and rotation of the fracture humeral diaphysis.

  20. Effects of fracture distribution and length scale on the equivalent continuum elastic compliance of fractured rock masses

    Directory of Open Access Journals (Sweden)

    Marte Gutierrez

    2015-12-01

    Full Text Available Fracture systems have strong influence on the overall mechanical behavior of fractured rock masses due to their relatively lower stiffness and shear strength than those of the rock matrix. Understanding the effects of fracture geometrical distribution, such as length, spacing, persistence and orientation, is important for quantifying the mechanical behavior of fractured rock masses. The relation between fracture geometry and the mechanical characteristics of the fractured rock mass is complicated due to the fact that the fracture geometry and mechanical behaviors of fractured rock mass are strongly dependent on the length scale. In this paper, a comprehensive study was conducted to determine the effects of fracture distribution on the equivalent continuum elastic compliance of fractured rock masses over a wide range of fracture lengths. To account for the stochastic nature of fracture distributions, three different simulation techniques involving Oda's elastic compliance tensor, Monte Carlo simulation (MCS, and suitable probability density functions (PDFs were employed to represent the elastic compliance of fractured rock masses. To yield geologically realistic results, parameters for defining fracture distributions were obtained from different geological fields. The influence of the key fracture parameters and their relations to the overall elastic behavior of the fractured rock mass were studied and discussed. A detailed study was also carried out to investigate the validity of the use of a representative element volume (REV in the equivalent continuum representation of fractured rock masses. A criterion was also proposed to determine the appropriate REV given the fracture distribution of the rock mass.

  1. General principles of radiotherapy

    International Nuclear Information System (INIS)

    Easson, E.C.

    1985-01-01

    The daily practice of any established branch of medicine should be based on some acceptable principles. This chapter is concerned with the general principles on which the radiotherapy of the Manchester school is based. Though many radiotherapists in other centres would doubtless accept these principles, there are sufficiently wide differences in practice throughout the world to suggest that some therapists adhere to a fundamentally different philosophy. The authors believe it is important, especially for those beginning their formal training in radiotherapy, to subscribe to an internally consistent school of thought, employing methods of treatment for each type of lesion in each anatomical site that are based on accepted principles and subjected to continuous rigorous scrutiny to test their effectiveness. Not only must each therapeutic technique be evaluated, but the underlying principles too must be questioned if and when this seems indicated. It is a feature of this hospital that similar lesions are all treated by the same technique, so long as statistical evidence justifies such a policy. All members of the staff adhere to the accepted policy until or unless reliable reasons are adduced to change this policy

  2. Safety Principles

    Directory of Open Access Journals (Sweden)

    V. A. Grinenko

    2011-06-01

    Full Text Available The offered material in the article is picked up so that the reader could have a complete representation about concept “safety”, intrinsic characteristics and formalization possibilities. Principles and possible strategy of safety are considered. A material of the article is destined for the experts who are taking up the problems of safety.

  3. Maquet principle

    Energy Technology Data Exchange (ETDEWEB)

    Levine, R.B.; Stassi, J.; Karasick, D.

    1985-04-01

    Anterior displacement of the tibial tubercle is a well-accepted orthopedic procedure in the treatment of certain patellofemoral disorders. The radiologic appearance of surgical procedures utilizing the Maquet principle has not been described in the radiologic literature. Familiarity with the physiologic and biochemical basis for the procedure and its postoperative appearance is necessary for appropriate roentgenographic evaluation and the radiographic recognition of complications.

  4. Cosmological principle

    International Nuclear Information System (INIS)

    Wesson, P.S.

    1979-01-01

    The Cosmological Principle states: the universe looks the same to all observers regardless of where they are located. To most astronomers today the Cosmological Principle means the universe looks the same to all observers because density of the galaxies is the same in all places. A new Cosmological Principle is proposed. It is called the Dimensional Cosmological Principle. It uses the properties of matter in the universe: density (rho), pressure (p), and mass (m) within some region of space of length (l). The laws of physics require incorporation of constants for gravity (G) and the speed of light (C). After combining the six parameters into dimensionless numbers, the best choices are: 8πGl 2 rho/c 2 , 8πGl 2 rho/c 4 , and 2 Gm/c 2 l (the Schwarzchild factor). The Dimensional Cosmological Principal came about because old ideas conflicted with the rapidly-growing body of observational evidence indicating that galaxies in the universe have a clumpy rather than uniform distribution

  5. Elbow Fractures

    Science.gov (United States)

    ... is also an important factor when treating elbow fractures. Casts are used more frequently in children, as their risk of developing elbow stiffness is small; however, in an adult, elbow stiffness is much more likely. Rehabilitation directed by your doctor is often used to ...

  6. Wrist Fractures

    Science.gov (United States)

    ... All Topics A-Z Videos Infographics Symptom Picker Anatomy Bones Joints Muscles Nerves Vessels Tendons About Hand Surgery What is a Hand Surgeon? What is a Hand Therapist? Media Find a Hand Surgeon Home Anatomy Wrist Fractures Email to a friend * required fields ...

  7. Shoulder Fractures

    Science.gov (United States)

    ... All Topics A-Z Videos Infographics Symptom Picker Anatomy Bones Joints Muscles Nerves Vessels Tendons About Hand Surgery What is a Hand Surgeon? What is a Hand Therapist? Media Find a Hand Surgeon Home Anatomy Shoulder Fractures Email to a friend * required fields ...

  8. USE OF CUTTING-EDGE HORIZONTAL AND UNDERBALANCED DRILLING TECHNOLOGIES AND SUBSURFACE SEISMIC TECHNIQUES TO EXPLORE, DRILL AND PRODUCE RESERVOIRED OIL AND GAS FROM THE FRACTURED MONTEREY BELOW 10,000 FT IN THE SANTA MARIA BASIN OF CALIFORNIA

    Energy Technology Data Exchange (ETDEWEB)

    George Witter; Robert Knoll; William Rehm; Thomas Williams

    2005-02-01

    This project was undertaken to demonstrate that oil and gas can be drilled and produced safely and economically from a fractured Monterey reservoir in the Santa Maria Basin of California by employing horizontal wellbores and underbalanced drilling technologies. Two vertical wells were previously drilled in this area by Temblor Petroleum with heavy mud and conventional completions; neither was commercially productive. A new well was drilled by the project team in 2004 with the objective of accessing an extended length of oil-bearing, high-resistivity Monterey shale via a horizontal wellbore, while implementing managed-pressure drilling (MPD) techniques to avoid formation damage. Initial project meetings were conducted in October 2003. The team confirmed that the demonstration well would be completed open-hole to minimize productivity impairment. Following an overview of the geologic setting and local field experience, critical aspects of the application were identified. At the pre-spud meeting in January 2004, the final well design was confirmed and the well programming/service company requirements assigned. Various design elements were reduced in scope due to significant budgetary constraints. Major alterations to the original plan included: (1) a VSP seismic survey was delayed to a later phase; (2) a new (larger) surface hole would be drilled rather than re-enter an existing well; (3) a 7-in. liner would be placed into the top of the Monterey target as quickly as possible to avoid problems with hole stability; (4) evaluation activities were reduced in scope; (5) geosteering observations for fracture access would be deduced from penetration rate, cuttings description and hydrocarbon in-flow; and (6) rather than use nitrogen, a novel air-injection MPD system was to be implemented. Drilling operations, delayed from the original schedule by capital constraints and lack of rig availability, were conducted from September 12 to November 11, 2004. The vertical and upper

  9. Use of Cutting-Edge Horizontal and Underbalanced Drilling Technologies and Subsurface Seismic Techniques to Explore, Drill and Produce Reservoired Oil and Gas from the Fractured Monterey Below 10,000 ft in the Santa Maria Basin of California

    Energy Technology Data Exchange (ETDEWEB)

    George Witter; Robert Knoll; William Rehm; Thomas Williams

    2005-09-29

    This project was undertaken to demonstrate that oil and gas can be drilled and produced safely and economically from a fractured Monterey reservoir in the Santa Maria Basin of California by employing horizontal wellbores and underbalanced drilling technologies. Two vertical wells were previously drilled in this area with heavy mud and conventional completions; neither was commercially productive. A new well was drilled by the project team in 2004 with the objective of accessing an extended length of oil-bearing, high-resistivity Monterey shale via a horizontal wellbore, while implementing managed-pressure drilling (MPD) techniques to avoid formation damage. Initial project meetings were conducted in October 2003. The team confirmed that the demonstration well would be completed open-hole to minimize productivity impairment. Following an overview of the geologic setting and local field experience, critical aspects of the application were identified. At the pre-spud meeting in January 2004, the final well design was confirmed and the well programming/service company requirements assigned. Various design elements were reduced in scope due to significant budgetary constraints. Major alterations to the original plan included: (1) a VSP seismic survey was delayed to a later phase; (2) a new (larger) surface hole would be drilled rather than re-enter an existing well; (3) a 7-in. liner would be placed into the top of the Monterey target as quickly as possible to avoid problems with hole stability; (4) evaluation activities were reduced in scope; (5) geosteering observations for fracture access would be deduced from penetration rate, cuttings description and hydrocarbon in-flow; and (6) rather than use nitrogen, a novel air-injection MPD system was to be implemented. Drilling operations, delayed from the original schedule by capital constraints and lack of rig availability, were conducted from September 12 to November 11, 2004. The vertical and upper curved sections were

  10. Outcome analysis of retrograde nailing and less invasive stabilization system in distal femoral fractures: A retrospective analysis

    Directory of Open Access Journals (Sweden)

    Christian Hierholzer

    2011-01-01

    Full Text Available Background: Two major therapeutic principles can be employed for the treatment of distal femoral fractures: retrograde intramedullary (IM nailing (RN or less invasive stabilization on system (LISS. Both operative stabilizing systems follow the principle of biological osteosynthesis. IM nailing protects the soft-tissue envelope due to its minimally invasive approach and closed reduction techniques better than distal femoral locked plating. The purpose of this study was to evaluate and compare outcome of distal femur fracture stabilization using RN or LISS techniques. Materials and Methods: In a retrospective study from 2003 to 2008, we analyzed 115 patients with distal femur fracture who had been treated by retrograde IM nailing (59 patients or LISS plating (56 patients. In the two cohort groups, mean age was 54 years (17-89 years. Mechanism of injury was high energy impact in 57% (53% RN, 67% LISS and low-energy injury in 43% (47% RN, 33% LISS, respectively. Fractures were classified according to AO classification: there were 52 type A fractures (RN 31, LISS 21 and 63 type C fractures (RN 28, LISS 35; 32% (RN and 56% (LISS were open and 68% (RN and 44% (LISS were closed fractures, respectively. Functional and radiological outcome was assessed. Results: Clinical and radiographic evaluation demonstrated osseous healing within 6 months following RN and following LISS plating in over 90% of patients. However, no statistically significant differences were found for the parameters time to osseous healing, rate of nonunion, and postoperative complications. The following complications were treated: hematoma formation (one patient RN and three patients LISS, superficial infection (one patient RN and three patients LISS, deep infection (2 patients LISS. Additional secondary bone grafting for successful healing 3 months after the primary operation was required in four patients in the RN (7% of patients and six in the LISS group (10% of patients

  11. Flow and contaminant transport in fractured rocks

    International Nuclear Information System (INIS)

    Bear, J.; Tsang, C.F.; Marsily, G. de

    1993-01-01

    This book is a compilation of nine articles dealing with various aspect of flow in fractured media. Articles range from radionuclide waste to multiphase flow in petroleum reservoirs to practical field test methods. Each chapter contains copious figures to aid the reader, but is also a detailed in-depth analysis of some major flow problem. The subjects covered are as follows: an introduction to flow and transport models; solute transport in fractured rock with application to radioactive waste repositories; solute transport models through fractured networks; theoretical view of stochastic models of fracture systems; numerical models of tracers; multiphase flow models in fractured systems and petroleum reservoirs; unsaturated flow modeling; comparative analysis of various flow modeling techniques in fractured media; and, a summary of field methods for measuring transfers of mass, heat, contaminant, momentum, and electrical charge in fractured media

  12. Principles of nuclear magnetic resonance imaging

    International Nuclear Information System (INIS)

    Pykett, I.L.; Newhouse, J.H.; Buonanno, F.S.; Brady, T.J.; Goldman, M.R.; Kistler, J.P.; Pohost, G.M.

    1982-01-01

    The physical principles which underlie the phenomenon of nuclear magnetic resonance (NMR) are presented in this primer. The major scanning methods are reviewed, and the principles of technique are discussed. A glossary of NMR terms is included

  13. Infrared and Raman spectroscopy: principles and spectral interpretation

    National Research Council Canada - National Science Library

    Larkin, Peter

    2011-01-01

    "Infrared and Raman Spectroscopy: Principles and Spectral Interpretation explains the background, core principles and tests the readers understanding of the important techniques of Infrared and Raman Spectroscopy...

  14. Classification Technique for Ultrasonic Weld Inspection Signals using a Neural Network based on 2-dimensional fourier Transform and Principle Component Analysis

    International Nuclear Information System (INIS)

    Kim, Jae Joon

    2004-01-01

    Neural network-based signal classification systems are increasingly used in the analysis of large volumes of data obtained in NDE applications. Ultrasonic inspection methods on the other hand are commonly used in the nondestructive evaluation of welds to detect flaws. An important characteristic of ultrasonic inspection is the ability to identify the type of discontinuity that gives rise to a peculiar signal. Standard techniques rely on differences in individual A-scans to classify the signals. This paper proposes an ultrasonic signal classification technique based on the information tying in the neighboring signals. The approach is based on a 2-dimensional Fourier transform and the principal component analysis to generate a reduced dimensional feature vector for classification. Results of applying the technique to data obtained from the inspection of actual steel welds are presented

  15. Bimalleolar ankle fracture with proximal fibular fracture

    NARCIS (Netherlands)

    Colenbrander, R. J.; Struijs, P. A. A.; Ultee, J. M.

    2005-01-01

    A 56-year-old female patient suffered a bimalleolar ankle fracture with an additional proximal fibular fracture. This is an unusual fracture type, seldom reported in literature. It was operatively treated by open reduction and internal fixation of the lateral malleolar fracture. The proximal fibular

  16. Outcomes of The Isolated Closed Tibial Shaft Fractures Treated Nonsurgically

    Directory of Open Access Journals (Sweden)

    Dawood Jafari

    2011-05-01

    Full Text Available Background: Fractures of the tibia are important for their commonness and controversy in their management. Both conservative and surgical techniques have been introduced in an effort to speed time to union while minimizing the occurrence of complications. Standard treatment for low-energy tibial shaft fractures includes closed reduction and cast immobilization.The purpose of our study was to analyze retention of reduction after cast immobilization of simple isolated closed tibial fractures.Methods:All cases of the diagnosed isolated closed tibial shaft fracture treated non-surgically at Shafa Yahyaeian Hospital, between 2006 and 2009 were retrieved from medical records. We reviewed all medical records and radiographs of these patients to inquire about the patients’ demographic data used to analyze the outcomes of the non-surgical treatment.Results:Of the 26 patients examined, males were more commonly affected. The mean age was 27.46   (SD=7.58.The most common causes of injury were direct blow and motorcycle to pedestrian accident. Followup duration for each patient had an average of 9.12 months (SD=2.36. Using AO/OTA classification, distributed as 38.5% A1.1, 26.9% A2.1 and 34.6% A3.1 fractures. Most fractures were sustained in the lower third of the tibia (53.85%. All fractures eventually healed in an average of 13.7 weeks (SD=3.24. There was one case of delayed union in the 22nd week. In 92.3% of patients, shortening of bone was less than 1 cm, while in 7.7% patients, was more than 1.5 cm. We observed an anterior or posterior angulation > 10 ° in 2 (7.69% patients. Moreover, in 4 (15.38% patients we found varus angulation > 5°. Therefore, final deformity was observed in 8 (30.77% patients. No patient had non-union, rotational malalignment of more than 10 degrees, an infection, or a compartment syndrome.Conclusion : Our non-surgical treatment’s outcomes were not satisfactory, despite applying all principles for conservative treatment and

  17. Application of geophysical methods for fracture characterization

    International Nuclear Information System (INIS)

    Lee, K.H.; Majer, E.L.; McEvilly, T.V.; California Univ., Berkeley, CA; Morrison, H.F.; California Univ., Berkeley, CA

    1990-01-01

    One of the most crucial needs in the design and implementation of an underground waste isolation facility is a reliable method for the detection and characterization of fractures in zones away from boreholes or subsurface workings. Geophysical methods may represent a solution to this problem. If fractures represent anomalies in the elastic properties or conductive properties of the rocks, then the seismic and electrical techniques may be useful in detecting and characterizing fracture properties. 7 refs., 3 figs

  18. Comparative evaluation of rotary ProTaper, Profile, and conventional stepback technique on reduction in Enterococcus faecalis colony-forming units and vertical root fracture resistance of root canals.

    Science.gov (United States)

    Singla, Mamta; Aggarwal, Vivek; Logani, Ajay; Shah, Naseem

    2010-03-01

    The purpose of this in vitro study was to evaluate the effect of various root canal instrumentation techniques with different instrument tapers on cleaning efficacy and resultant vertical root fracture (VRF) strength of the roots. Fifty human mandibular first premolar roots were enlarged to ISO size 20, inoculated with Enterococcus faecalis [ATCC2912] for 72 hours and divided into 5 groups: group I: prepared with .02 taper hand instruments ISO size 40; group II: Profile .04 taper size 40; group III: Profile .06 taper size 40; group IV: ProTaper size F4; and group V (control group) further divided into: Va: with bacterial inoculation and no mechanical instrumentation; and Group Vb: neither bacterial inoculation nor mechanical instrumentation. Cleaning efficacy was evaluated in terms of reduction of colony forming units (CFUs). The VRF strength was evaluated using D11 spreader as wedge in an Instron testing machine. Root canals instrumented with ProTaper and 6% Profile instruments showed maximum reduction in CFUs, with statistically insignificant difference between them. The VRF resistance decreased in all instrumented groups. The difference of VRF between 2% and 4% taper Profile groups was statistically insignificant (P = .195). One-way analysis of variance showed that canals instrumented with ProTaper F4 showed maximum reduction in VRF resistance compared with control uninstrumented group. Profile 6% taper instruments offer the advantage of maximum debridement without significant reduction in root fracture resistance. Copyright 2010 Mosby, Inc. All rights reserved.

  19. Pediatric facial fractures: evolving patterns of treatment.

    Science.gov (United States)

    Posnick, J C; Wells, M; Pron, G E

    1993-08-01

    This study reviews the treatment of facial trauma between October 1986 and December 1990 at a major pediatric referral center. The mechanism of injury, location and pattern of facial fractures, pattern of facial injury, soft tissue injuries, and any associated injuries to other organ systems were recorded, and fracture management and perioperative complications reviewed. The study population consisted of 137 patients who sustained 318 facial fractures. Eighty-one patients (171 fractures) were seen in the acute stage, and 56 patients (147 fractures) were seen for reconstruction of a secondary deformity. Injuries in boys were more prevalent than in girls (63% versus 37%), and the 6- to 12-year cohort made up the largest group (42%). Most fractures resulted from traffic-related accidents (50%), falls (23%), or sports-related injuries (15%). Mandibular (34%) and orbital fractures (23%) predominated; fewer midfacial fractures (7%) were sustained than would be expected in a similar adult population. Three quarters of the patients with acute fractures required operative intervention. Closed reduction techniques with maxillomandibular fixation were frequently chosen for mandibular condyle fractures and open reduction techniques (35%) for other regions of the facial skeleton. When open reduction was indicated, plate-and-screw fixation was the preferred method of stabilization (65%). The long-term effects of the injuries and the treatment given on facial growth remain undetermined. Perioperative complication rates directly related to the surgery were low.

  20. Fracture mechanics

    International Nuclear Information System (INIS)

    Miannay, D.P.

    1995-01-01

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

  1. Fractures of the growing mandible.

    Science.gov (United States)

    Kushner, George M; Tiwana, Paul S

    2009-03-01

    Oral and maxillofacial surgeons must constantly weigh the risks of surgical intervention for pediatric mandible fractures against the wonderful healing capacity of children. The majority of pediatric mandibular fractures can be managed with closed techniques using short periods of maxillomandibular fixation or training elastics alone. Generally, the use of plate- and screw-type internal fixation is reserved for difficult fractures. This article details general and special considerations for this surgery including: craniofacial growth & development, surgical anatomy, epidemiology evaluation, various fractures, the role rigid internal fixation and the Risdon cable in pediatric maxillofacial trauma. It concludes with suggestions concerning long-term follow-up care in light of the mobility, insurance obstacles, and family dynamics facing the patient population.

  2. The treatment of subtrochanteric fractures

    Directory of Open Access Journals (Sweden)

    Vučetić Čedomir S.

    2011-01-01

    Full Text Available Subtrochanteric fractures of the femur have a special place because of a significant number of complications following treatment. Powerful loading forces asymmetrically acting to this bone segment, as well as poor vascularization interfere with bone union. There are basically two current approaches in the fixation of subtrochanteric fractures; the first involves a plate with a compression screw and another one is intramedullary (IM nail, with two options: centromedullary (standard interlocking femoral nail and cephalomedullary femoral nail with two modifications, reconstructive and trochanteric. All IM nails may be used by open technique or closed minimal invasive method. IM nailing is favoured in view of a shorter operative time, shorter hospitalisation and complications. Indirect fracture reduction and knowledge of biology of bone fracture may result in full success without any bone graft.

  3. [Development of Patient Transfer Techniques based on Postural-stability Principles for the Care Helpers in Nursing Homes and Evaluation of Effectiveness].

    Science.gov (United States)

    Ma, Ryewon; Jung, Dukyoo

    2016-02-01

    This study was done to develop a postural-stability patient transfer technique for care helpers in nursing homes and to evaluate its effectiveness. Four types of patient transfer techniques (Lifting towards the head board of the bed, turning to the lateral position, sitting upright on the bed, transferring from wheel chair to bed) were practiced in accordance with the following three methods; Care helpers habitually used transfer methods (Method 1), patient transfer methods according to care helper standard textbooks (Method 2), and a method developed by the author ensuring postural-stability (Method 3). The care helpers' muscle activity and four joint angles were measured. The collected data were analyzed using the program SPSS Statistic 21.0. To differentiate the muscle activity and joint angle, the Friedman test was executed and the post-hoc analysis was conducted using the Wilcoxon Signed Rank test. Muscle activity was significantly lower during Method 3 compared to Methods 1 and 2. In addition, the joint angle was significantly lower for the knee and shoulder joint angle while performing Method 3 compared to Methods 1 and 2. Findings indicate that using postural-stability patient transfer techniques can contribute to the prevention of musculoskeletal disease which care helpers suffer from due to physically demanding patient care in nursing homes.

  4. Principle and modelling of Transient Current Technique for interface traps characterization in monolithic pixel detectors obtained by CMOS-compatible wafer bonding

    International Nuclear Information System (INIS)

    Bronuzzi, J.; Mapelli, A.; Moll, M.; Sallese, J.M.

    2016-01-01

    In the framework of monolithic silicon radiation detectors, a fabrication process based on a recently developed silicon wafer bonding technique at low temperature was proposed. Ideally, this new process would enable direct bonding of a read-out electronic chip wafer on a highly resistive silicon substrate wafer, which is expected to present many advantages since it would combine high performance IC's with high sensitive ultra-low doped bulk silicon detectors. But electrical properties of the bonded interface are critical for this kind of application since the mobile charges generated by radiation inside the bonded bulk are expected to transit through the interface in order to be collected by the read-out electronics. In this work, we propose to explore and develop a model for the so-called Transient Current Technique (TCT) to identify the presence of deep traps at the bonded interface. For this purpose, we consider a simple PIN diode reversely biased where the ultra-low doped active region of interest is set in full depletion. In a first step, Synopsys Sentaurus TCAD is used to evaluate the soundness of this technique for interface traps characterization such as it may happen in bonded interfaces. Next, an analytical model is developed in details to give a better insight into the physics behind the TCT for interface layers. Further, this can be used as a simple tool to evidence what are the relevant parameters influencing the TCT signal and to set the basis for preliminary characterizations.

  5. Zymography Principles.

    Science.gov (United States)

    Wilkesman, Jeff; Kurz, Liliana

    2017-01-01

    Zymography, the detection, identification, and even quantification of enzyme activity fractionated by gel electrophoresis, has received increasing attention in the last years, as revealed by the number of articles published. A number of enzymes are routinely detected by zymography, especially with clinical interest. This introductory chapter reviews the major principles behind zymography. New advances of this method are basically focused towards two-dimensional zymography and transfer zymography as will be explained in the rest of the chapters. Some general considerations when performing the experiments are outlined as well as the major troubleshooting and safety issues necessary for correct development of the electrophoresis.

  6. Basic principles

    International Nuclear Information System (INIS)

    Wilson, P.D.

    1996-01-01

    Some basic explanations are given of the principles underlying the nuclear fuel cycle, starting with the physics of atomic and nuclear structure and continuing with nuclear energy and reactors, fuel and waste management and finally a discussion of economics and the future. An important aspect of the fuel cycle concerns the possibility of ''closing the back end'' i.e. reprocessing the waste or unused fuel in order to re-use it in reactors of various kinds. The alternative, the ''oncethrough'' cycle, discards the discharged fuel completely. An interim measure involves the prolonged storage of highly radioactive waste fuel. (UK)

  7. Principles of mathematical modeling

    CERN Document Server

    Dym, Clive

    2004-01-01

    Science and engineering students depend heavily on concepts of mathematical modeling. In an age where almost everything is done on a computer, author Clive Dym believes that students need to understand and "own" the underlying mathematics that computers are doing on their behalf. His goal for Principles of Mathematical Modeling, Second Edition, is to engage the student reader in developing a foundational understanding of the subject that will serve them well into their careers. The first half of the book begins with a clearly defined set of modeling principles, and then introduces a set of foundational tools including dimensional analysis, scaling techniques, and approximation and validation techniques. The second half demonstrates the latest applications for these tools to a broad variety of subjects, including exponential growth and decay in fields ranging from biology to economics, traffic flow, free and forced vibration of mechanical and other systems, and optimization problems in biology, structures, an...

  8. Autotransplantation of Mandibular Third Molar with Buccal Cortical Plate to Replace Vertically Fractured Mandibular Second Molar: A Novel Technique.

    Science.gov (United States)

    Zufía, Juan; Abella, Francesc; Trebol, Ivan; Gómez-Meda, Ramón

    2017-09-01

    Tooth replacement often leads to inadequate vertical volume in the recipient site bone when a tooth has been extracted because of a vertical root fracture (VRF). This case report presents the autotransplantation of a mandibular third molar (tooth #32) with the attached buccal cortical plate to replace a mandibular second molar (tooth #31) diagnosed with a VRF. After extraction of tooth #31, the recipient socket was prepared based on the size measured in advance with cone-beam computed tomographic imaging. The precise and calculated osteotomy of the cortical bone of tooth #32 allowed for the exact placement of the donor tooth in the position of tooth #31. The total extraoral time was only 25 minutes. The block was fixed to the recipient socket with an osteosynthesis screw and splinted with a double resin wire for 8 weeks. At the 6-month follow-up, the screw was removed, and the stability of the tooth and the regeneration obtained throughout the vestibular area were confirmed. At the 2-year follow-up, the transplanted tooth was asymptomatic and maintained a normal bone level. Advantages of autotransplantation over dental implants include maintenance of proprioception, possible orthodontic movements, and a relatively low cost. This case report demonstrates that an autotransplantation of a third molar attached to its buccal cortical plate is a viable option to replace teeth with a VRF. Copyright © 2017 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  9. Ultra-Fine Bubble Distributions in a Plant Factory Observed by Transmission Electron Microscope with a Freeze-Fracture Replica Technique

    Directory of Open Access Journals (Sweden)

    Tsutomu Uchida

    2018-03-01

    Full Text Available Water containing ultra-fine bubbles (UFB may promote plant growth. But, as UFBs are too small to distinguish from other impurities in a nutrient solution, it is not known if UFBs survive transport from the water source to the rhizosphere. Here we use the freeze-fracture replica method and a transmission electron microscope (TEM to observe UFBs in the nutrient solutions used in a crop-growing system known as a plant factory. In this factory, TEM images taken from various points in the supply line indicate that the concentration of UFBs in the nutrient solution is conserved, starting from their addition to the nutrient solution in the buffer tank, through the peat-moss layer, all the way to the rhizosphere. Measurements also show that a thin film formed on the surface of UFBs in the nutrient solution, with greater film thickness at the rhizosphere. This film is considered to be made from the accumulation of impurities coming from solute and the peat-moss layer.

  10. XFEM modeling of hydraulic fracture in porous rocks with natural fractures

    Science.gov (United States)

    Wang, Tao; Liu, ZhanLi; Zeng, QingLei; Gao, Yue; Zhuang, Zhuo

    2017-08-01

    Hydraulic fracture (HF) in porous rocks is a complex multi-physics coupling process which involves fluid flow, diffusion and solid deformation. In this paper, the extended finite element method (XFEM) coupling with Biot theory is developed to study the HF in permeable rocks with natural fractures (NFs). In the recent XFEM based computational HF models, the fluid flow in fractures and interstitials of the porous media are mostly solved separately, which brings difficulties in dealing with complex fracture morphology. In our new model the fluid flow is solved in a unified framework by considering the fractures as a kind of special porous media and introducing Poiseuille-type flow inside them instead of Darcy-type flow. The most advantage is that it is very convenient to deal with fluid flow inside the complex fracture network, which is important in shale gas extraction. The weak formulation for the new coupled model is derived based on virtual work principle, which includes the XFEM formulation for multiple fractures and fractures intersection in porous media and finite element formulation for the unified fluid flow. Then the plane strain Kristianovic-Geertsma-de Klerk (KGD) model and the fluid flow inside the fracture network are simulated to validate the accuracy and applicability of this method. The numerical results show that large injection rate, low rock permeability and isotropic in-situ stresses tend to lead to a more uniform and productive fracture network.

  11. Monolayer freeze-fracture autoradiography: quantitative analysis of the transmembrane distribution of radioiodinated concanavalin A

    International Nuclear Information System (INIS)

    Fisher, K.A.

    1982-01-01

    The technique of monolayer freeze-fracture autoradiography (MONOFARG) has been developed and the principles, quantitation, and application of the method are described. Cell monolayers attached to polylysine-treated glass were freeze-fractured, shadowed, and coated with dry, Parlodion-supported Ilford L4 photographic emulsion at room temperature. Quantitative aspects of MONOFARG were examined using radioiodinated test systems. Background was routinely -4 grains/μm 2 /day, the highest overall efficiency was between 25% and 45%, and grain density and efficiency were dependent on radiation dose for iodine-125 and D-19 development. Corrected grain densities were linearly proportional to iodine-125 concentration. The method was applied to an examination of the transmembrane distribution of radioiodinated and fluoresceinated concanavalin A ( 125 I-FITC-Con-A). Human erythrocytes were labeled, column-purified, freeze-dried or freeze-fractured, autoradiographed, and examined by electron microscopy. The number of silver grains per square micrometer of unsplit single membrane was essentially identical to that of split extracellular membrane halves. These data demonstrate that 125 I-FITC-Con-A partitions exclusively with the extracellular half of the membrane upon freeze-fracturing and can be used as a quantitative marker for the fraction of extracellular split membrane halves. This method should be able to provide new information about certain transmembrane properties of biological membrane molecules and probes, as well as about the process of freeze-fracture per se

  12. Principle and modelling of Transient Current Technique for interface traps characterization in monolithic pixel detectors obtained by CMOS-compatible wafer bonding

    CERN Document Server

    Bronuzzi, J.; Moll, M.; Sallese, J.M.

    2016-01-01

    In the framework of monolithic silicon radiation detectors, a fabrication process based on a recently developed silicon wafer bonding technique at low temperature was proposed. Ideally, this new process would enable direct bonding of a read-out electronic chip wafer on a highly resistive silicon substrate wafer, which is expected to present many advantages since it would combine high performance IC's with high sensitive ultra-low doped bulk silicon detectors. But electrical properties of the bonded interface are critical for this kind of application since the mobile charges generated by radiation inside the bonded bulk are expected to transit through the interface in order to be collected by the read-out electronics. In this work, we propose to explore and develop a model for the so-called Transient Current Technique (TCT) to identify the presence of deep traps at the bonded interface. For this purpose, we consider a simple PIN diode reversely biased where the ultra-low doped active region of interest is set ...

  13. Identifying Fracture Types and Relative Ages Using Fluid Inclusion Stratigraphy

    Energy Technology Data Exchange (ETDEWEB)

    Dilley, Lorie M.; Norman, David; Owens, Lara

    2008-06-30

    Enhanced Geothermal Systems (EGS) are designed to recover heat from the subsurface by mechanically creating fractures in subsurface rocks. Understanding the life cycle of a fracture in a geothermal system is fundamental to the development of techniques for creating fractures. Recognizing the stage of a fracture, whether it is currently open and transmitting fluids; if it recently has closed; or if it is an ancient fracture would assist in targeting areas for further fracture stimulation. Identifying dense fracture areas as well as large open fractures from small fracture systems will also assist in fracture stimulation selection. Geothermal systems are constantly generating fractures, and fluids and gases passing through rocks in these systems leave small fluid and gas samples trapped in healed microfractures. Fluid inclusions trapped in minerals as the fractures heal are characteristic of the fluids that formed them, and this signature can be seen in fluid inclusion gas analysis. Our hypothesis is that fractures over their life cycle have different chemical signatures that we can see in fluid inclusion gas analysis and by using the new method of fluid inclusion stratigraphy (FIS) the different stages of fractures, along with an estimate of fracture size can be identified during the well drilling process. We have shown with this study that it is possible to identify fracture locations using FIS and that different fractures have different chemical signatures however that signature is somewhat dependent upon rock type. Open, active fractures correlate with increase concentrations of CO2, N2, Ar, and to a lesser extent H2O. These fractures would be targets for further enhancement. The usefulness of this method is that it is low cost alternative to current well logging techniques and can be done as a well is being drilled.

  14. Hip fracture - discharge

    Science.gov (United States)

    ... neck fracture repair - discharge; Trochanteric fracture repair - discharge; Hip pinning surgery - discharge ... in the hospital for surgery to repair a hip fracture, a break in the upper part of ...

  15. Anchorage strategies in geriatric hip fracture management

    Directory of Open Access Journals (Sweden)

    Knobe Matthias

    2016-12-01

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

  16. A lower border augmentation technique to allow implant placement after a bilateral mandibular fracture as a complication of vertical distraction osteogenesis: a case report

    NARCIS (Netherlands)

    Perdijk, F.B.T.; Meijer, G.J.; Soehardi, A.; Koole, R.A.

    2013-01-01

    As with other techniques, vertical distraction osteogenesis (VDO) can also induce complications. The case of a patient with a residual alveolar ridge in the symphyseal area of 8mm is presented. After performing VDO, the patient returned at 1-day postoperatively complaining of pain and dislocation of

  17. On combination of strict Bayesian principles with model reduction technique or how stochastic model calibration can become feasible for large-scale applications

    Science.gov (United States)

    Oladyshkin, S.; Schroeder, P.; Class, H.; Nowak, W.

    2013-12-01

    Predicting underground carbon dioxide (CO2) storage represents a challenging problem in a complex dynamic system. Due to lacking information about reservoir parameters, quantification of uncertainties may become the dominant question in risk assessment. Calibration on past observed data from pilot-scale test injection can improve the predictive power of the involved geological, flow, and transport models. The current work performs history matching to pressure time series from a pilot storage site operated in Europe, maintained during an injection period. Simulation of compressible two-phase flow and transport (CO2/brine) in the considered site is computationally very demanding, requiring about 12 days of CPU time for an individual model run. For that reason, brute-force approaches for calibration are not feasible. In the current work, we explore an advanced framework for history matching based on the arbitrary polynomial chaos expansion (aPC) and strict Bayesian principles. The aPC [1] offers a drastic but accurate stochastic model reduction. Unlike many previous chaos expansions, it can handle arbitrary probability distribution shapes of uncertain parameters, and can therefore handle directly the statistical information appearing during the matching procedure. We capture the dependence of model output on these multipliers with the expansion-based reduced model. In our study we keep the spatial heterogeneity suggested by geophysical methods, but consider uncertainty in the magnitude of permeability trough zone-wise permeability multipliers. Next combined the aPC with Bootstrap filtering (a brute-force but fully accurate Bayesian updating mechanism) in order to perform the matching. In comparison to (Ensemble) Kalman Filters, our method accounts for higher-order statistical moments and for the non-linearity of both the forward model and the inversion, and thus allows a rigorous quantification of calibrated model uncertainty. The usually high computational costs of

  18. Hydraulic fracturing proppants

    Directory of Open Access Journals (Sweden)

    V. P. P. de Campos

    Full Text Available Abstract Hydrocarbon reservoirs can be classified as unconventional or conventional depending on the oil and gas extraction difficulty, such as the need for high-cost technology and techniques. The hydrocarbon extraction from bituminous shale, commonly known as shale gas/oil, is performed by using the hydraulic fracturing technique in unconventional reservoirs where 95% water, 0.5% of additives and 4.5% of proppants are used. Environmental problems related to hydraulic fracturing technique and better performance/development of proppants are the current challenge faced by companies, researchers, regulatory agencies, environmentalists, governments and society. Shale gas is expected to increase USA fuel production, which triggers the development of new proppants and technologies of exploration. This paper presents a review of the definition of proppants, their types, characteristics and situation in the world market and information about manufacturers. The production of nanoscale materials such as anticorrosive and intelligent proppants besides proppants with carbon nanotubes is already carried out on a scale of tonnes per year in Belgium, Germany and Asia countries.

  19. Internal Fixation of Transverse Patella Fractures Using Cannulated Cancellous Screws with Anterior Tension Band Wiring

    Directory of Open Access Journals (Sweden)

    Khan I

    2016-07-01

    Full Text Available Aims: To evaluate the effectiveness and safety of anterior tension band wiring technique using two cannulated cancellous screws in patients with transverse (AO34-C1 or transverse with mildly comminuted (AO34-C2 patellar fractures. Materials and Methods: This is a prospective study of 25 patients with transverse fracture or transverse fracture with mildly comminuted patella fractures. All the patients were treated with open reduction and internal fixation using two parallel cannulated screws and 18G stainless steel wire as per the tension band principle. Results: There were eighteen males (72% and seven females (28%. The age group ranged from 24 to 58 years, with mean age of 38 years. The most common mode of injury was fall (72% followed by road traffic accident (20% and violent quadriceps contraction (8%. Transverse fracture was present in 60% and transverse fracture with mild comminution in 40% of patients. Mean time to achieve union was 10.7 weeks (range 8-12 weeks. Mean ROM at three months was 113.8 degree (90-130 and at final follow up this improved to 125.4 degrees (range 100-140. There was one case of knee stiffness and no case of implant failure was observed. Patients were evaluated using Bostman scoring, the mean score at three months being 26.04 which improved to 27.36 at the end of final follow up at one year. Conclusion: Cannulated cancellous screws with anterior tension band wiring is a safe, reliable and reproducible method in management of transverse patellar fractures, with less chances of implant failure and soft tissue irritation.

  20. Proximal femoral fractures.

    Science.gov (United States)

    Webb, Lawrence X

    2002-01-01

    Fractures of the proximal femur include fractures of the head, neck, intertrochanteric, and subtrochanteric regions. Head fractures commonly accompany dislocations. Neck fractures and intertrochanteric fractures occur with greatest frequency in elderly patients with a low bone mineral density and are produced by low-energy mechanisms. Subtrochanteric fractures occur in a predominantly strong cortical osseous region which is exposed to large compressive stresses. Implants used to address these fractures must be able to accommodate significant loads while the fractures consolidate. Complications secondary to these injuries produce significant morbidity and include infection, nonunion, malunion, decubitus ulcers, fat emboli, deep venous thrombosis, pulmonary embolus, pneumonia, myocardial infarction, stroke, and death.

  1. Development of innovative techniques and principles that may be used as models to improve plant performance. Technical progress report, February 1, 1990--January 31, 1993

    Energy Technology Data Exchange (ETDEWEB)

    Hanna, W.W.; Burton, G.W.

    1992-06-01

    Methods and techniques for transferring germplasm from wild to cultivated species are being developed. The transferred germplasm is being shown to be valuable in plant breeding and in cultivar development. In the primary gene pool of the grassy Pennisetum glaucum subspecies monodii germplasm, some cytoplasms are being identified that appear to have significant effects on forage yields and morphological characteristics. One cytoplasm, A{sub 4}, is very stable for male sterility and fertility is not easily restored by other lines. It should be a valuable cytoplasm for producing commercial forage hybrids. Disease resistance and yield genes transferred from monodii to cultivated pearl millet lines are having a major impact on increasing production of animals grazing disease resistant Tifleaf 2 pearl millet. Genes controlling resistance to many of the world-wide diseases on pearl millet are being identified in the monodii germplasm. Valuable germplasm has been transferred from the secondary gene pool P. purpuroum) which is used as the pollinator of the first pearl millet grain hybrid in the US Production of 7-chromosome gametes in 42-chromosome interspecific hybrids appears to be genotype specific and makes possible transfer of germplasm from the secondary gene pool to cultivated diploid pearl millet. Significant progress has been made in transferring genes controlling apomixis from P. squamulatum (tertiary gene pool) to cultivated pearl millet. Highly apomictic BC{sub 4} plants have been recovered, one of which sets five times as much seed as the best BC{sub 3} plant.

  2. Imaging of vertebral fracture in osteoporosis

    International Nuclear Information System (INIS)

    Skowronska-Jozwiak, E.; Lewinski, A.; Bieganski, T.

    2008-01-01

    Vertebral collapses are the most frequent fractures in osteoporosis. They are often overlooked, although their presence is a strong risk factor for development of new fractures. Lateral radiographs of the spine are the accepted standard for assessment of fractures. Qualitative (visual), semiquantitative and quantitative (morphometric) techniques are useful in determining the compressive deformities of vertebral bodies. In the present paper, the advantages and the disadvantages of these methods are discussed. The improvement of scan quality allows to use DXA technique to diagnose the fractures, in both - the visual and the morphometric way. The vertebral morphologic assessment also seems to be an important diagnostic tool in pediatric osteoporosis. Application of multidetector CT and especially MR in vertebral imaging of osteoporosis, improves the sensitivity of fracture detection and enables the differentiation of benign from malignant vertebral body collapses. (author)

  3. Evaluation of Fractured Basement Complex Rock Porosity by ...

    African Journals Online (AJOL)

    current resistivity sounding as complementary geophysical technique to Schlumberger vertical electrical sounding in characterizing fractured geologic systems. Previously, Schlumberger vertical electrical sounding was used to collect data.

  4. Principles of Mechanical Excavation

    International Nuclear Information System (INIS)

    Lislerud, A.

    1997-12-01

    Mechanical excavation of rock today includes several methods such as tunnel boring, raiseboring, roadheading and various continuous mining systems. Of these raiseboring is one potential technique for excavating shafts in the repository for spent nuclear fuel and dry blind boring is promising technique for excavation of deposition holes, as demonstrated in the Research Tunnel at Olkiluoto. In addition, there is potential for use of other mechanical excavation techniques in different parts of the repository. One of the main objectives of this study was to analyze the factors which affect the feasibility of mechanical rock excavation in hard rock conditions and to enhance the understanding of factors which affect rock cutting so as to provide an improved basis for excavator performance prediction modeling. The study included the following four main topics: (a) phenomenological model based on similarity analysis for roller disk cutting, (b) rock mass properties which affect rock cuttability and tool life, (c) principles for linear and field cutting tests and performance prediction modeling and (d) cutter head lacing design procedures and principles. As a conclusion of this study, a test rig was constructed, field tests were planned and started up. The results of the study can be used to improve the performance prediction models used to assess the feasibility of different mechanical excavation techniques at various repository investigation sites. (orig.)

  5. Principles of Mechanical Excavation

    Energy Technology Data Exchange (ETDEWEB)

    Lislerud, A. [Tamrock Corp., Tampere (Finland)

    1997-12-01

    Mechanical excavation of rock today includes several methods such as tunnel boring, raiseboring, roadheading and various continuous mining systems. Of these raiseboring is one potential technique for excavating shafts in the repository for spent nuclear fuel and dry blind boring is promising technique for excavation of deposition holes, as demonstrated in the Research Tunnel at Olkiluoto. In addition, there is potential for use of other mechanical excavation techniques in different parts of the repository. One of the main objectives of this study was to analyze the factors which affect the feasibility of mechanical rock excavation in hard rock conditions and to enhance the understanding of factors which affect rock cutting so as to provide an improved basis for excavator performance prediction modeling. The study included the following four main topics: (a) phenomenological model based on similarity analysis for roller disk cutting, (b) rock mass properties which affect rock cuttability and tool life, (c) principles for linear and field cutting tests and performance prediction modeling and (d) cutter head lacing design procedures and principles. As a conclusion of this study, a test rig was constructed, field tests were planned and started up. The results of the study can be used to improve the performance prediction models used to assess the feasibility of different mechanical excavation techniques at various repository investigation sites. (orig.). 21 refs.

  6. Selectively placing many fractures in openhole horizontal wells improves production

    Energy Technology Data Exchange (ETDEWEB)

    Love, T. G.; McCarty, R. A. [Chevron USA Inc (United States); Suraatmadja, J. B.; Chambers, R. W.; Grundmann, S. R.

    1998-12-31

    Result of a simulation of an openhole horizontal well that was treated with hydrajet fracturing, a new fracturing process wherein fractures are placed at different locations in a horizontal well without using sectional isolation techniques, are discussed. The process uses high-pressure jetting to concentrate fracturing energy at a precise fracture location, and data is obtained by means of surface and downhole pressure recorders, flow recorders, and tracers. This technique was used in a substantially depleted horizontal well in New Mexico with good results. The new process is reported to be expensive to implement which prevents widespread application at the present time. 7 refs., 9 figs.

  7. Addresing environmental challenges to shale gas and hydraulic fracturing

    Energy Technology Data Exchange (ETDEWEB)

    Vadillo Fernandez, L.; Rodriguez Gomez, V.; Fernadez Naranjo, F.J.

    2016-07-01

    This article reviews the main issues of unconventional gas extracted by hydraulic fracturing techniques. Topics such as technology, fracturing stages, flowback characterization and alternatives of disposal and reuse, water consumption, physicochemical features of the geological formations, development of the fractures performed by hydraulic fracturing, well flow decline, land use and occupation and induced seismicity are presented, as well as the scientific debate: the potential steps of methane gas and groundwater contamination. (Author)

  8. Dating fractures and fracture movement in the Lac du Bonnet Batholith

    International Nuclear Information System (INIS)

    Gascoyne, M.; Brown, A.; Ejeckam, R.B.; Everitt, R.A.

    1997-04-01

    This report examines and summarizes all work that has been done from 1980 to the present in determining the age of rock crystallization, fracture initiation, fracture reactivation and rates of fracture movement in the Lac du Bonnet Batholith to provide information for Atomic Energy of Canada Limited's (AECL) Canadian Nuclear Fuel Waste Management Program. Geological and petrographical indicators of relative age (e.g. cross-cutting relationships, sequences of fracture infilling minerals, P-T characteristics of primary and secondary minerals) are calibrated with radiometric age determinations on minerals and whole rock samples, using 87 Rb- 87 Sr, 40 K- 39 Ar, 40 Ar- 39 Ar and fission track methods. Most fractures and fracture zones inclined at low angles are found to be ancient features, first formed in the Early Proterozoic under conditions of deuteric alteration. Following some movement on fractures in the Late Proterozoic and Early Paleozoic, reactivation of fractures during the Pleistocene is established from uranium-series dating methods and use of stable isotopic contents of fracture infilling minerals (mainly calcite). Some indication of movement on fracture zones during the Pleistocene is given by electron spin resonance dating techniques on fault gouge. The slow rate of propagation of fractures is indicated by mineral infillings, their P-T characteristics and U-series calcite ages in a fracture in sparsely fractured rock, accessible from AECL's Underground Research Laboratory. These results collectively indicate that deep fractures observed in the batholith are ancient features and the fracturing and jointing in the upper 200 m is relatively recent (< 1 Ma) and largely a result of stress release. (author)

  9. Principles of Stellar Interferometry

    CERN Document Server

    Glindemann, Andreas

    2011-01-01

    Over the last decade, stellar interferometry has developed from a specialist tool to a mainstream observing technique, attracting scientists whose research benefits from milliarcsecond angular resolution. Stellar interferometry has become part of the astronomer’s toolbox, complementing single-telescope observations by providing unique capabilities that will advance astronomical research. This carefully written book is intended to provide a solid understanding of the principles of stellar interferometry to students starting an astronomical research project in this field or to develop instruments and to astronomers using interferometry but who are not interferometrists per se. Illustrated by excellent drawings and calculated graphs the imaging process in stellar interferometers is explained starting from first principles on light propagation and diffraction wave propagation through turbulence is described in detail using Kolmogorov statistics the impact of turbulence on the imaging process is discussed both f...

  10. Principles of mobile communication

    CERN Document Server

    Stüber, Gordon L

    2017-01-01

    This mathematically rigorous overview of physical layer wireless communications is now in a 4th, fully revised and updated edition. The new edition features new content on 4G cellular systems, 5G cellular outlook, bandpass signals and systems, and polarization, among many other topics, in addition to a new chapters on channel assignment techniques. Along with coverage of fundamentals and basic principles sufficient for novice students, the volume includes finer details that satisfy the requirements of graduate students aiming to conduct in-depth research. The book begins with a survey of the field, introducing issues relevant to wireless communications. The book moves on to cover relevant discrete subjects, from radio propagation, to error probability performance, and cellular radio resource management. An appendix provides a tutorial on probability and random processes. The content stresses core principles that are applicable to a broad range of wireless standards. New examples are provided throughout the bo...

  11. MR-urography and CT-urography: principles, examination techniques, applications; MR-Urographie und CT-Urographie: Prinzipien, Untersuchungstechniken, Anwendungsmoeglichkeiten

    Energy Technology Data Exchange (ETDEWEB)

    Nolte-Ernsting, C.; Adam, G. [Universitaetsklinikum Hamburg-Eppendorf (Germany). Klinik fuer Diagnostische und Interventionelle Radiologie; Staatz, G.; Wildberger, J. [RWTH Aachen (Germany). Klinik fuer Radiologische Diagnostik

    2003-02-01

    MR-urography (MRU) and CT-urography (CTU) provide refined imaging of the upper urinary tract not achievable with conventional intravenous urography (IVU). The traditional MR-urographic technique utilizes unenhanced, heavily T{sub 2}-weighted turbo spin-echo sequences for obtaining static fluid images of the urinary tract independent of the excretory renal function. T{sub 2}-weighted MR-urograms have proved to be excellent in visualizing the dilated urinary tract, even in non-excreting kidneys. In contrast, T{sub 1}-weighted MRU reflects the excretory renal function and displays the urine flow through the upper tract after renal excretion of an intravenously administered gadolinium chelate. The gadolinium-enhanced urine is visualized with fast T{sub 1}-weighted 3D-gradient-echo sequences. The combination of gadolinium and low-dose furosemide (5-10 mg) is the key for achieving a uniform distribution of gadolinium in the collecting system and for avoiding susceptibility artifacts (T{sub 2}*-effects) in the urine. T{sub 1}-weighted excretory MRU provides impressive urograms of both non-dilated and obstructed collecting systems in patients with normal or moderately impaired renal function. Multislice-CT-urography (MS-CTU) is also an excretory urography like T{sub 1}-weighted MRU. Furthermore, MS-CTU can be combined with low-dose furosemide for accelerated passage of excreted contrast material obviating the need for abdominal compression. CT-urography is limited by its radiation burden and the nephrotoxicity of radiographic contrast media. Combining MRU or MS-CTU with conventional MRI or CT offers several applications, e.g., diagnosis of intrinsic and extrinsic tumors. Meanwhile, MRU has replaced IVU in pediatric uroradiology and is also recommended for the assessment of renal transplants. MS-CTU may provide valuable information in chronic urolithiasis, especially if associated with a distorted urinary tract anatomy. Both MRU and MS-CTU will play an important role in

  12. The art of trochanteric fracture reduction.

    Science.gov (United States)

    Biber, Roland; Berger, Johanna; Bail, Hermann Josef

    2016-12-01

    The name of Ender is primarily associated with the Ender nails, which were popular for trochanteric fracture fixation more than thirty years ago. However, Ender's concepts were not limited to the implant. Ender developed a unique classification system for trochanteric and subtrochanteric fractures, which provided the theory for closed reduction maneuvers that made the method so successful in his hands. While Ender's nails have become history in the meantime, his principles of fracture reduction can be readily applied on surgery with modern implants such as proximal femoral nails. This article reflects the classification and the principles published by Hans Georg Ender in some print work hardly available nowadays. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Traumatic thoracolumbar spine fractures

    NARCIS (Netherlands)

    J. Siebenga (Jan)

    2013-01-01

    textabstractTraumatic spinal fractures have the lowest functional outcomes and the lowest rates of return to work after injury of all major organ systems.1 This thesis will cover traumatic thoracolumbar spine fractures and not osteoporotic spine fractures because of the difference in fracture

  14. Fractures in multiple sclerosis

    DEFF Research Database (Denmark)

    Stenager, E; Jensen, K

    1991-01-01

    In a cross-sectional study of 299 MS patients 22 have had fractures and of these 17 after onset of MS. The fractures most frequently involved the femoral neck and trochanter (41%). Three patients had had more than one fracture. Only 1 patient had osteoporosis. The percentage of fractures increase...

  15. Numerical Investigation of Fracture Propagation in Geomaterials

    Science.gov (United States)

    Newell, P.; Borowski, E.; Major, J. R.; Eichhubl, P.

    2015-12-01

    Fracture in geomaterials is a critical behavior that affects the long-term structural response of geosystems. The processes involving fracture initiation and growth in rocks often span broad time scales and size scales, contributing to the complexity of these problems. To better understand fracture behavior, the authors propose an initial investigation comparing the fracture testing techniques of notched three-point bending (N3PB), short rod (SR), and double torsion (DT) on geomaterials using computational analysis. Linear softening cohesive fracture modeling (LCFM) was applied using ABAQUS to computationally simulate the three experimental set-ups. By applying material properties obtained experimentally, these simulations are intended to predict single-trace fracture growth. The advantages and limitations of the three testing techniques were considered for application to subcritical fracture propagation taking into account the accuracy of constraints, load applications, and modes of fracture. This work is supported as part of the Geomechanics of CO2 Reservoir Seals, a DOE-NETL funded under Award Number DE-FOA-0001037. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  16. Gesture & Principle

    DEFF Research Database (Denmark)

    Hvejsel, Marie Frier

    2018-01-01

    as a student, professional, or architectural researcher. It is the hypothesis of this paper that, in its initial questioning of the task of the Greek tekton (as a masterbuilder) capable of bringing together aesthetics and technique in a given context, tectonic theory has unique potential in this matter......, installations, and equipment threaten to undermine the primary spatial purpose and quality of architecture as a sensuous enrichment of everyday life. This calls for continuous critical positioning within the field as well as a systematic method for acquiring knowledge about an architectural problem, whether....... This potential is investigated through a rereading of the development of tectonic theory in architecture, which is done in relation to the present conditions and methodological challenges facing the discipline. As a result, this paper outlines a direction for the repositioning, development, and application...

  17. Materials characterization techniques

    National Research Council Canada - National Science Library

    Zhang, Sam; Li, L; Kumar, Ashok

    2009-01-01

    "With an emphasis on practical applications and real-world case studies, Materials Characterization Techniques presents the principles of widely used advanced surface and structural characterization...

  18. [Intramedullary osteosynthesis of distal metacarpal fractures with curved wires].

    Science.gov (United States)

    Schlageter, M; Winkel, R; Porcher, R; Haas, H G

    1997-07-01

    When intramedullary pinning is used to treat metacarpal fractures, as recently described by Förstner (1994) and Foucher (1995), the closed reduction technique developed by Jahss (1938) is applied in the same way as for conservative fracture treatment. It is not always possible to achieve complete anatomical reduction using this closed technique. The intramedullary pinning technique, that we have applied since 1989, involves a Kirschner wire which is bent at one end. Apart from reducing the fracture, the pre-set Kirschner wire serves as a butressing internal fixator. The elastic clamping of the wire acts as an internal wire spring splint, permitting early mobilisation. We have operated on 62 metacarpal fractures using the above-mentioned technique over a period of 6 years until 1995. Anatomic reduction was realized in 50 of 62 fractures. In the follow-up of 32 fractures, we noticed four complications: one infection, two paraesthesias, and one non-union.

  19. Fluid driven fracture mechanics in highly anisotropic shale: a laboratory study with application to hydraulic fracturing

    Science.gov (United States)

    Gehne, Stephan; Benson, Philip; Koor, Nick; Enfield, Mark

    2017-04-01

    The finding of considerable volumes of hydrocarbon resources within tight sedimentary rock formations in the UK led to focused attention on the fundamental fracture properties of low permeability rock types and hydraulic fracturing. Despite much research in these fields, there remains a scarcity of available experimental data concerning the fracture mechanics of fluid driven fracturing and the fracture properties of anisotropic, low permeability rock types. In this study, hydraulic fracturing is simulated in a controlled laboratory environment to track fracture nucleation (location) and propagation (velocity) in space and time and assess how environmental factors and rock properties influence the fracture process and the developing fracture network. Here we report data on employing fluid overpressure to generate a permeable network of micro tensile fractures in a highly anisotropic shale ( 50% P-wave velocity anisotropy). Experiments are carried out in a triaxial deformation apparatus using cylindrical samples. The bedding planes are orientated either parallel or normal to the major principal stress direction (σ1). A newly developed technique, using a steel guide arrangement to direct pressurised fluid into a sealed section of an axially drilled conduit, allows the pore fluid to contact the rock directly and to initiate tensile fractures from the pre-defined zone inside the sample. Acoustic Emission location is used to record and map the nucleation and development of the micro-fracture network. Indirect tensile strength measurements at atmospheric pressure show a high tensile strength anisotropy ( 60%) of the shale. Depending on the relative bedding orientation within the stress field, we find that fluid induced fractures in the sample propagate in two of the three principal fracture orientations: Divider and Short-Transverse. The fracture progresses parallel to the bedding plane (Short-Transverse orientation) if the bedding plane is aligned (parallel) with the

  20. CT of the acetabular fracture

    International Nuclear Information System (INIS)

    Magu, N.K.; Moda, S.K.; Magu, Sarita; Airon, R.K.

    1993-01-01

    Nine patients with 10 injured hips, in whom acetabular fractures with posterior dislocation of the femoral heads were demonstrated on initial radiography, underwent CT. CT was found superior in detecting the presence of intra-articular bony fragments in Group A patients (40%), where conventional radiography exhibited congruous manipulative reduction of the joint surfaces. The spatial position of the intra-articular fragments could not be ascertained on conventional radiography in 40% of the patients in Group B, in whom congruous manipulative reduction could not be achieved and subluxation of the femoral heads was observed. On conventional radiography, it was also difficult to appreciate the presence of intra-articular fragments in 60% of the patients in Group B, in whom either the dislocation could not be reduced (40%) or the femoral head redislocated after close manipulative reduction (20%). CT proved its superiority in detecting the extent of the fractures of the acetabular roof, posterior and anterior acetabular margins, the quadrilateral plate along with rotation of the acetabular columns and displacements of the major fractured fragments. Associated fractures of the sacrum (20%), and traumatic lesions of the sacro-iliac joint (20%), not apparent on conventional radiography were well demonstrated by CT. As a result of CT, the treatment was changed in 60% of the patients in Group A, and 40% in Group B. In addition, CT permitted a better choice of surgical technique in the management of acetabular fractures. (author). 9 refs., 3 figs., 2 tabs

  1. The Influence of Hydraulic Fracturing on Carbon Storage Performance

    Science.gov (United States)

    Fu, Pengcheng; Settgast, Randolph R.; Hao, Yue; Morris, Joseph P.; Ryerson, Frederick J.

    2017-12-01

    Conventional principles of the design and operation of geologic carbon storage (GCS) require injecting CO2 below the caprock fracturing pressure to ensure the integrity of the storage complex. In nonideal storage reservoirs with relatively low permeability, pressure buildup can lead to hydraulic fracturing of the reservoir and caprock. While the GCS community has generally viewed hydraulic fractures as a key risk to storage integrity, a carefully designed stimulation treatment under appropriate geologic conditions could provide improved injectivity while maintaining overall seal integrity. A vertically contained hydraulic fracture, either in the reservoir rock or extending a limited height into the caprock, provides an effective means to access reservoir volume far from the injection well. Employing a fully coupled numerical model of hydraulic fracturing, solid deformation, and matrix fluid flow, we study the enabling conditions, processes, and mechanisms of hydraulic fracturing during CO2 injection. A hydraulic fracture's pressure-limiting behavior dictates that the near-well fluid pressure is only slightly higher than the fracturing pressure of the rock and is insensitive to injection rate and mechanical properties of the formation. Although a fracture contained solely within the reservoir rock with no caprock penetration, would be an ideal scenario, poroelastic principles dictate that sustaining such a fracture could lead to continuously increasing pressure until the caprock fractures. We also investigate the propagation pattern and injection pressure responses of a hydraulic fracture propagating in a caprock subjected to heterogeneous in situ stress. The results have important implications for the use of hydraulic fracturing as a tool for managing storage performance.

  2. General principles

    International Nuclear Information System (INIS)

    Hutchison, J.M.S.; Foster, M.A.

    1987-01-01

    NMR characteristics are not unique - T/sub 1/ values of tumour tissues overlap with those from multiple sclerosis plaques or from areas of inflammation. Despite this, NMR imaging is an extremely powerful tool to the diagnostician and for other medical use such as following the course of treatment or planning or surgery or radiotherapy. Magnetic resonance imaging (MRI) is often used solely as an anatomical technique similar to X-ray CT. This is certainly an appropriate use for it and it has certain advantages over X-ray CT such as the greater ease with which sagittal and coronal sections can be obtained (or other views by suitable manipulation of the gradients) NMR is also less bothered by bone-related artefacts. There are disadvantages in terms of resolution (although this is improving) and of speed of acquisition of the image. The NMR signal, however, derives from a complex interaction of biophysical properties and, if properly used, can yield a considerable amount of information about its origin. The NMR image is capable of much more manipulation than that obtained by X-ray methods and, particularly with the addition of spectroscopy to the repertoire the authors expect in vivo NMR examinations to yield much metabolic and biophysical information in addition to providing a demonstration of the anatomy of the body

  3. Operative treatment of early infection after internal fixation of limb fractures (exclusive of severe open fractures).

    Science.gov (United States)

    Bonnevialle, P

    2017-02-01

    Early infection after open reduction and internal fixation (ORIF) of a limb bone is defined as bacteriologically documented, deep and/or superficial surgical-site infection (SSI) diagnosed within 6months after the surgical procedure. This interval is arbitrarily considered sufficient to obtain fracture healing. The treatment of early infection after ORIF should be decided by a multidisciplinary team. The principles are the same as for revision arthroplasty. Superficial SSIs should be differentiated from deep SSIs, based on the results of bacteriological specimens collected using flawless technique. A turning point in the local microbial ecology occurs around the third or fourth week, when a biofilm develops around metallic implants. This biofilm protects the bacteria. The treatment relies on both non-operative and operative measures, which are selected based on the time to occurrence of the infection, condition of the soft tissues, and stage of bone healing. Both the surgical strategy and the antibiotic regimen should be determined during a multidisciplinary discussion. When treating superficial SSIs after ORIF, soft-tissue management is the main challenge. The treatment differs according to whether the hardware is covered or exposed. Defects in the skin and/or fascia can be managed using reliable reconstructive surgery techniques, either immediately or after a brief period of vacuum-assisted closure. In deep SSIs, deciding whether to leave or to remove the hardware is difficult. If the hardware is removed, the fracture site can be stabilised provisionally using either external fixation or a cement rod. Once infection control is achieved, several measures can be taken to stimulate bone healing before the end of the classical 6-month interval. If the hardware was removed, then internal fixation must be performed once the infection is eradicated. Copyright © 2016. Published by Elsevier Masson SAS.

  4. Fraturas odontomaxilares e mandibulares em eqüídeos tratados por diferentes técnicas de osteossíntese Odontomaxillares and mandibularies fractures in equides treated with different osteosynthesis techniques

    Directory of Open Access Journals (Sweden)

    G.E.S. Alves

    2008-12-01

    Full Text Available Oito eqüinos e um muar com fraturas odontomaxilares e mandibulares foram tratados com diferentes técnicas de osteossíntese modificadas, consistindo de cerclagens associadas ou não a bandas de tensão, placa de neutralização e pino intraosseo, sendo este aplicado com metodologia não encontrada na literatura consultada. Os procedimentos cirúrgicos nos eqüideos foram realizados com os animais em estação mediante contenção física, em brete, e química, com sedação ou neuroleptoanalgesia associada a bloqueios anestésicos regionais. Os animais apresentaram capacidade de mastigação e ingestão voluntária no pós-operatório imediato e recuperação óssea adequada.Eight equines and one mule with odontomaxillaries and mandibularies fractures were treated with different osteosynthesis modified techniques, consisting of cerclages with or without tension bands, neutralization plates, and intraosseous pin applied by a methodology which was not found in the literature. The surgery procedures in equides were performed with the animals in stand position under physical contention, sedation, or neuroleptoanalgesy and regional nerve block. All animals were able to eat voluntarily in the immediate post-operatory time and had good bone recuperation.

  5. Fractures in sport: Optimising their management and outcome

    Science.gov (United States)

    Robertson, Greg AJ; Wood, Alexander M

    2015-01-01

    Fractures in sport are a specialised cohort of fracture injuries, occurring in a high functioning population, in which the goals are rapid restoration of function and return to play with the minimal symptom profile possible. While the general principles of fracture management, namely accurate fracture reduction, appropriate immobilisation and timely rehabilitation, guide the treatment of these injuries, management of fractures in athletic populations can differ significantly from those in the general population, due to the need to facilitate a rapid return to high demand activities. However, despite fractures comprising up to 10% of all of sporting injuries, dedicated research into the management and outcome of sport-related fractures is limited. In order to assess the optimal methods of treating such injuries, and so allow optimisation of their outcome, the evidence for the management of each specific sport-related fracture type requires assessment and analysis. We present and review the current evidence directing management of fractures in athletes with an aim to promote valid innovative methods and optimise the outcome of such injuries. From this, key recommendations are provided for the management of the common fracture types seen in the athlete. Six case reports are also presented to illustrate the management planning and application of sport-focussed fracture management in the clinical setting. PMID:26716081

  6. The laser principles and application techniques

    International Nuclear Information System (INIS)

    Maillet, H.

    1990-01-01

    In this book on laser applications chapter 4 is devoted to uranium isotopic separation and chapter 5 to laser inertial fusion, other topics include machining, medical applications, measurements, military applications, holography, reprography, telecommunications, compact discs, light shows and safety [fr

  7. Principles and techniques of data evaluation

    International Nuclear Information System (INIS)

    Froehner, F.H.

    1986-08-01

    The probabilistic foundations of data evaluations are reviewed, with special emphasis on parameter estimation based on Bayes' theorem and modern methods concerning prior probabilities. The process leading from raw data to evaluated data files is briefly explained for the example of nuclear reaction cross sections, with a discussion of systematic and statistical errors and their propagation. It is shown how evaluators can establish data covariances if error components are properly specified by experimentalists, and how correlated data uncertainties in covariance files are utilised in sensitivity studies and accuracy assessments. The problem of inconsistent data is also addressed briefly. (orig.) [de

  8. Principles and techniques of uranium enrichment

    International Nuclear Information System (INIS)

    Frejacques, Claude; Mezin, Michel

    1975-01-01

    The main separation processes already used industrially or likely to be used before the end of century (gas diffusion, ultracentrifugation, laser, the nozzle process, a process developed in South Africa) are presented. Some data on the costs of the enrichment are clarified. The main characteristics of the enrichment market in which the Eurodif plant is called upon, on the expiration of five years, to take a foremost place are reported [fr

  9. Measuring library performance principles and techniques

    CERN Document Server

    Brophy, Peter

    2006-01-01

    Provide an account of thinking and research on the evaluation of library services. Illustrated throughout with examples across the different library sectors, this book is structured to focus on the intended service user, then to look at service management and the building blocks of services, and finally to draw together these strands.

  10. Perioperative lateral trochanteric wall fractures: sliding hip screw versus percutaneous compression plate for intertrochanteric hip fractures.

    Science.gov (United States)

    Langford, Joshua; Pillai, Gita; Ugliailoro, Anthony D; Yang, Edward

    2011-04-01

    This study was performed to determine the incidence of perioperative lateral wall fractures with a standard sliding hip screw (SHS) versus a percutaneous compression plate (PCCP) using identical meticulous closed reduction techniques in both groups. Retrospective analysis of a prospective trauma registry. Urban Level I trauma center. Over a 7-year period, 337 patients with intertrochanteric hip fractures were treated with either a SHS or a PCCP at our institution. The PCCP group (Group 1) consisted of 200 patients, of which 141 (71%) had adequate images to be included in the study. The SHS group (Group 2) consisted of 137 patients, of which 100 (73%) had adequate images to be included in the study. Closed reduction and plate application with either a standard sliding hip screw or a percutaneous compression plate for an Orthopaedic Trauma Association 31A1 or 31A2 intertrochanteric hip fracture. : Radiographic evidence of lateral trochanteric wall fracture as measured by intraoperative and perioperative radiographs. There was an overall lateral wall fracture incidence of 20% in the SHS group versus 1.4% in the PCCP group (P fracture types, there was a lateral wall fracture incidence of 29.8% in the SHS group versus 1.9% in the PCCP group (P trochanteric wall fracture compared with the SHS group. This difference became greater when just unstable intertrochanteric fractures were analyzed. An anatomic reduction, combined with a device (PCCP) that uses small-diameter defects in the lateral trochanteric wall, essentially eliminates perioperative lateral trochanteric wall fractures.

  11. Fracture propagation in sandstone and slate – Laboratory experiments, acoustic emissions and fracture mechanics

    Directory of Open Access Journals (Sweden)

    Ferdinand Stoeckhert

    2015-06-01

    Full Text Available Fracturing of highly anisotropic rocks is a problem often encountered in the stimulation of unconventional hydrocarbon or geothermal reservoirs by hydraulic fracturing. Fracture propagation in isotropic material is well understood but strictly isotropic rocks are rarely found in nature. This study aims at the examination of fracture initiation and propagation processes in a highly anisotropic rock, specifically slate. We performed a series of tensile fracturing laboratory experiments under uniaxial as well as triaxial loading. Cubic specimens with edge lengths of 150 mm and a central borehole with a diameter of 13 mm were prepared from Fredeburg slate. An experiment using the rather isotropic Bebertal sandstone as a rather isotropic rock was also performed for comparison. Tensile fractures were generated using the sleeve fracturing technique, in which a polymer tube placed inside the borehole is pressurized to generate tensile fractures emanating from the borehole. In the uniaxial test series, the loading was varied in order to observe the transition from strength-dominated fracture propagation at low loading magnitudes to stress-dominated fracture propagation at high loading magnitudes.

  12. Hybrid external fixation in the treatment of tibial pilon fractures: A retrospective analysis of 162 fractures.

    Science.gov (United States)

    Galante, Vito N; Vicenti, Giovanni; Corina, Gianfranco; Mori, Claudio; Abate, Antonella; Picca, Girolamo; Conserva, Vito; Speciale, Domenico; Scialpi, Lorenzo; Tartaglia, Nicola; Caiaffa, Vincenzo; Moretti, Biagio

    2016-10-01

    To determine the efficacy of hybrid external fixation in the treatment of tibial pilon fractures. Retrospective, multicentre study. Adult patients with tibial pilon fractures treated with hybrid external fixation. Fracture reduction with ligamentotaxis and fixation with XCaliber hybrid external fixator. Fracture union, complications, functional outcome (Mazur Ankle Score). Union was obtained in 159 fractures at an average of 125days; there were three delayed unions and three non-unions. The most frequent complication was superficial pin-track infections (48), all of which responded to local wound care and antibiotics. There were no deep infections and no DVT. Only one fracture had loss of reduction that required frame revision. The overall functional scores were 91 (excellent) for AO/OTA type A fractures, 89 (good) for type B fractures, and 75 (satisfactory) for type C fractures. Hybrid external fixation is an effective method of stabilising tibial pilon fractures, particularly those with marked comminution. The minimally-invasive technique and stable fixation enable early mobilisation, with good functional results and minimal complications. Level IV Case series. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Paratrooper's ankle fracture: posterior malleolar fracture.

    Science.gov (United States)

    Young, Ki Won; Kim, Jin-su; Cho, Jae Ho; Kim, Hyung Seuk; Cho, Hun Ki; Lee, Kyung Tai

    2015-03-01

    We assessed the frequency and types of ankle fractures that frequently occur during parachute landings of special operation unit personnel and analyzed the causes. Fifty-six members of the special force brigade of the military who had sustained ankle fractures during parachute landings between January 2005 and April 2010 were retrospectively analyzed. The injury sites and fracture sites were identified and the fracture types were categorized by the Lauge-Hansen and Weber classifications. Follow-up surveys were performed with respect to the American Orthopedic Foot and Ankle Society ankle-hindfoot score, patient satisfaction, and return to preinjury activity. The patients were all males with a mean age of 23.6 years. There were 28 right and 28 left ankle fractures. Twenty-two patients had simple fractures and 34 patients had comminuted fractures. The average number of injury and fractures sites per person was 2.07 (116 injuries including a syndesmosis injury and a deltoid injury) and 1.75 (98 fracture sites), respectively. Twenty-three cases (41.07%) were accompanied by posterior malleolar fractures. Fifty-five patients underwent surgery; of these, 30 had plate internal fixations. Weber type A, B, and C fractures were found in 4, 38, and 14 cases, respectively. Based on the Lauge-Hansen classification, supination-external rotation injuries were found in 20 cases, supination-adduction injuries in 22 cases, pronation-external rotation injuries in 11 cases, tibiofibular fractures in 2 cases, and simple medial malleolar fractures in 2 cases. The mean follow-up period was 23.8 months, and the average follow-up American Orthopedic Foot and Ankle Society ankle-hindfoot score was 85.42. Forty-five patients (80.36%) reported excellent or good satisfaction with the outcome. Posterior malleolar fractures occurred in 41.07% of ankle fractures sustained in parachute landings. Because most of the ankle fractures in parachute injuries were compound fractures, most cases had to

  14. Neglected, semimembranosus osteochondral avulsion fracture of the posteromedial tibial plateau

    Directory of Open Access Journals (Sweden)

    Rakesh John

    2018-06-01

    Full Text Available Semimembranosus avulsion fracture is infrequently reported and is easy to miss on plain radiographs; the mechanism of injury is highly controversial. Initial reports linked it to anterior cruciate ligament and medial meniscal tears. We report an osteochondral semimembranosus avulsion fracture of the posteromedial tibial plateau with associated posterior cruciate ligament rupture. Also described is a novel surgical fixation technique for such osteochondral fractures where the surgical exposure is limited due to the obliquity of the fracture line resulting in a greater involvement of the articular cartilage than the small bony component. The fixation technique described may be used for osteochondral fractures where the application of a conventional compression screw may not be feasible. Keywords: Osteochondral fracture, Semimembranosus avulsion fracture, Posteromedial tibial plateau, Neglected, Nonunion

  15. The gauge principle vs. the equivalence principle

    International Nuclear Information System (INIS)

    Gates, S.J. Jr.

    1984-01-01

    Within the context of field theory, it is argued that the role of the equivalence principle may be replaced by the principle of gauge invariance to provide a logical framework for theories of gravitation

  16. Computed tomography of tibial plateau fractures

    International Nuclear Information System (INIS)

    Rafii, M.; Firooznia, H.; Golimbu, C.; Bonamo, J.

    1984-01-01

    Twenty patients with tibial plateau fractures were studied by conventional tomography and computed tomography (CT) in order to determine the role and feasibility of CT in management of such patients. CT resulted in less discomfort to the patient and provided optimal visualization of the plateau defect and the split fragments. It proved more accurate than conventional tomography in assessing depressed and split fractures when they involved the anterior or posterior border of the plateau and in demonstrating the extent of fracture comminution. Split fragments with an oblique plane of fracture also were seen better by CT. The degree of fracture depression and separation as measured by the computerized technique was often more accurate than measurements obtained from conventional tomograms

  17. Equivalence principles and electromagnetism

    Science.gov (United States)

    Ni, W.-T.

    1977-01-01

    The implications of the weak equivalence principles are investigated in detail for electromagnetic systems in a general framework. In particular, it is shown that the universality of free-fall trajectories (Galileo weak equivalence principle) does not imply the validity of the Einstein equivalence principle. However, the Galileo principle plus the universality of free-fall rotation states does imply the Einstein principle.

  18. Implant-supported rehabilitation after treatment of atrophic mandibular fractures: report of two cases.

    Science.gov (United States)

    Oliveira, Leandro Benetti de; Gabrielli, Marisa Aparecida Cabrini; Gabrielli, Mario Francisco Real; Pereira-Filho, Valfrido Antonio Pereira

    2015-12-01

    The objective of this article is to present options of rehabilitation with dental implants in two cases of severely atrophic mandibles (fractures. Two patients who sustained fractures in severely atrophic mandibles with less than 10 mm of bone height were treated by open reduction and internal fixation through a transcervical access. Internal fixation was obtained with 2.4-mm locking reconstruction plates. The first patient presented satisfactory bone height at the area between the mental foramens and after 2 years, received flapless guided implants in the anterior mandible and an immediate protocol prosthesis. The second patient received a tent pole iliac crest autogenous graft after 2 years of fracture treatment and immediate implants. After 5 months, a protocol prosthesis was installed in the second patient. In both cases, the internal fixation followed AO principles for load-bearing osteosynthesis. Both prosthetic devices were Branemark protocol prosthesis. The mandibular reconstruction plates were not removed. Both patients are rehabilitated without complications and satisfied with esthetic and functional results. With the current techniques of internal fixation, grafting, and guided implants, the treatment of atrophic mandible fractures can achieve very good results, which were previously not possible.

  19. Fracture mechanical materials characterisation

    International Nuclear Information System (INIS)

    Wallin, K.; Planman, T.; Nevalainen, M.

    1998-01-01

    The experimental fracture mechanics development has been focused on the determination of reliable lower-bound fracture toughness estimates from small and miniature specimens, in particular considering the statistical aspects and loading rate effects of fracture mechanical material properties. Additionally, materials aspects in fracture assessment of surface cracks, with emphasis on the transferability of fracture toughness data to structures with surface flaws have been investigated. Further a modified crack-arrest fracture toughness test method, to increase the effectiveness of testing, has been developed. (orig.)

  20. Spatial arrangement of faults and opening-mode fractures

    Science.gov (United States)

    Laubach, S. E.; Lamarche, J.; Gauthier, B. D. M.; Dunne, W. M.; Sanderson, David J.

    2018-03-01

    Spatial arrangement is a fundamental characteristic of fracture arrays. The pattern of fault and opening-mode fracture positions in space defines structural heterogeneity and anisotropy in a rock volume, governs how faults and fractures affect fluid flow, and impacts our understanding of the initiation, propagation and interactions during the formation of fracture patterns. This special issue highlights recent progress with respect to characterizing and understanding the spatial arrangements of fault and fracture patterns, providing examples over a wide range of scales and structural settings. Five papers describe new methods and improvements of existing techniques to quantify spatial arrangement. One study unravels the time evolution of opening-mode fracture spatial arrangement, which are data needed to compare natural patterns with progressive fracture growth in kinematic and mechanical models. Three papers investigate the role of evolving diagenesis in localizing fractures by mechanical stratigraphy and nine discuss opening-mode fracture spatial arrangement. Two papers show the relevance of complex cluster patterns to unconventional reservoirs through examples of fractures in tight gas sandstone horizontal wells, and a study of fracture arrangement in shale. Four papers demonstrate the roles of folds in fracture localization and the development spatial patterns. One paper models along-fault friction and fluid pressure and their effects on fault-related fracture arrangement. Contributions address deformation band patterns in carbonate rocks and fault size and arrangement above a detachment fault. Three papers describe fault and fracture arrangements in basement terrains, and three document fracture patterns in shale. This collection of papers points toward improvement in field methods, continuing improvements in computer-based data analysis and creation of synthetic fracture patterns, and opportunities for further understanding fault and fracture attributes in

  1. Petrous bone fracture: a virtual trauma analysis.

    Science.gov (United States)

    Montava, Marion; Deveze, Arnaud; Arnoux, Pierre-Jean; Bidal, Samuel; Brunet, Christian; Lavieille, Jean-Pierre

    2012-06-01

    The temporal bone shields sensorineural, nervous, and vascular structures explaining the potential severity and complications of trauma related to road and sport accidents. So far, no clear data are available on the exact mechanisms involved for fracture processes. Modelization of structures helps to answer these concerns. Our objective was to design a finite element model of the petrous bone structure to modelize temporal bone fracture propagation in a scenario of lateral impact. A finite element model of the petrous bone structure was designed based on computed tomography data. A 7-m/s lateral impact was simulated to reproduce a typical lateral trauma. Results of model analysis was based on force recorded, stress level on bone structure up to induce a solution of continuity of the bony structure. Model simulation showed that bone fractures follow the main axes of the petrous bone and occurred in a 2-step process: first, a crush, and second, a massive fissuration of the petrous bone. The lines of fracture obtained by simulation of a lateral impact converge toward the middle ear region. This longitudinal fracture is located at the mastoid-petrous pyramid junction. Using this model, it was possible to map petrous bone fractures including fracture chronology and areas of fusion of the middle ear region. This technique may represent a first step to investigate the pathophysiology of the petrous bone fractures, aiming to define prognostic criteria for patients' care.

  2. Surgical Management of a Mandible Subcondylar Fracture

    Directory of Open Access Journals (Sweden)

    Dong Hee Kang

    2012-07-01

    Full Text Available Open reduction and anatomic reduction can create better function for the temporomandibularjoint, compared with closed treatment in mandible fracture surgery. Therefore, the doubleminiplate fixation technique via mini-retromandibular incision was used in order to makethe most stable fixation when performing subcondylar fracture surgery. Those approachesprovide good visualization of the subcondyle from the posterior edge of the ramus, allow thesurgeon to work perpendicularly to the fracture, and enable direct fracture management.Understanding the biomechanical load in the fixation of subcondylar fractures is alsonecessary in order to optimize fixation methods. Therefore, we measured the biomechanicalloads of four different plate fixation techniques in the experimental model regardingmandibular subcondylar fractures. It was found that the loads measured in the two-platefixation group with one dynamic compression plate (DCP and one adaption plate showed thehighest deformation and failure loads among the four fixation groups. The loads measuredin the one DCP plate fixation group showed higher deformation and failure loads than theloads measured in the two adaption plate fixation group. Therefore, we conclude that theselection of the high profile plate (DCP is also important in order to create a stable load in thesubcondylar fracture.

  3. Surgical Management of a Mandible Subcondylar Fracture

    Directory of Open Access Journals (Sweden)

    Dong Hee Kang

    2012-07-01

    Full Text Available Open reduction and anatomic reduction can create better function for the temporomandibular joint, compared with closed treatment in mandible fracture surgery. Therefore, the double miniplate fixation technique via mini-retromandibular incision was used in order to make the most stable fixation when performing subcondylar fracture surgery. Those approaches provide good visualization of the subcondyle from the posterior edge of the ramus, allow the surgeon to work perpendicularly to the fracture, and enable direct fracture management. Understanding the biomechanical load in the fixation of subcondylar fractures is also necessary in order to optimize fixation methods. Therefore, we measured the biomechanical loads of four different plate fixation techniques in the experimental model regarding mandibular subcondylar fractures. It was found that the loads measured in the two-plate fixation group with one dynamic compression plate (DCP and one adaption plate showed the highest deformation and failure loads among the four fixation groups. The loads measured in the one DCP plate fixation group showed higher deformation and failure loads than the loads measured in the two adaption plate fixation group. Therefore, we conclude that the selection of the high profile plate (DCP is also important in order to create a stable load in the subcondylar fracture.

  4. Physical simulation study on the hydraulic fracture propagation of coalbed methane well

    Science.gov (United States)

    Wu, Caifang; Zhang, Xiaoyang; Wang, Meng; Zhou, Longgang; Jiang, Wei

    2018-03-01

    As the most widely used technique to modify reservoirs in the exploitation of unconventional natural gas, hydraulic fracturing could effectively raise the production of CBM wells. To study the propagation rules of hydraulic fractures, analyze the fracture morphology, and obtain the controlling factors, a physical simulation experiment was conducted with a tri-axial hydraulic fracturing test system. In this experiment, the fracturing sample - including the roof, the floor, and the surrounding rock - was prepared from coal and similar materials, and the whole fracturing process was monitored by an acoustic emission instrument. The results demonstrated that the number of hydraulic fractures in coal is considerably higher than that observed in other parts, and the fracture morphology was complex. Vertical fractures were interwoven with horizontal fractures, forming a connected network. With the injection of fracturing fluid, a new hydraulic fracture was produced and it extended along the preexisting fractures. The fracture propagation was a discontinuous, dynamic process. Furthermore, in-situ stress plays a key role in fracture propagation, causing the fractures to extend in a direction perpendicular to the minimum principal stress. To a certain extent, the different mechanical properties of the coal and the other components inhibited the vertical propagation of hydraulic fractures. Nonetheless, the vertical stress and the interfacial property are the major factors to influence the formation of the "T" shaped and "工" shaped fractures.

  5. Measurement of bone mineral density in the tunnel regions for anterior cruciate ligament reconstruction by dual-energy X-ray absorptiometry, computed tomography scan, and the immersion technique based on Archimedes' principle.

    Science.gov (United States)

    Tie, Kai; Wang, Hua; Wang, Xin; Chen, Liaobin

    2012-10-01

    To determine, for anterior cruciate ligament (ACL) reconstruction, whether the bone mineral density (BMD) of the femoral tunnel was higher than that of the tibial tunnel, to provide objective evidence for choosing the appropriate diameter of interference screws. Two groups were enrolled. One group comprised 30 normal volunteers, and the other comprised 9 patients with ACL rupture. Dual-energy X-ray absorptiometry was used to measure the BMD of the femoral and tibial tunnel regions of the volunteers' right knees by choosing a circular area covering the screw fixation region. The knees were also scanned by spiral computed tomography (CT), and the 3-dimensional reconstruction technique was used to determine the circular sections passing through the longitudinal axis of the femoral and tibial tunnels. Grayscale CT values of the cross-sectional area were measured. Cylindrical cancellous bone blocks were removed from the femoral and tibial tunnels during the ACL reconstruction for the patients. The volumetric BMD of the bone blocks was measured using a standardized immersion technique according to Archimedes' principle. As measured by dual-energy X-ray absorptiometry, the BMD of the femoral and tibial tunnel regions was 1.162 ± 0.034 g/cm(2) and 0.814 ± 0.038 g/cm(2), respectively (P difference in both femoral and tibial tunnel regions. For ACL reconstruction, the BMD of the femoral tunnel is higher than that of the tibial tunnel. This implies that a proportionally larger-diameter interference screw should be used for fixation in the proximal tibia than that used for fixation in the distal femur. Level IV, therapeutic case series. Copyright © 2012 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

  6. Freeze-fracture study of Trichomonas vaginalis

    Directory of Open Access Journals (Sweden)

    Marlene Benchimol

    1990-12-01

    Full Text Available The freeze-fracture technique was used to analyse the organization of the plasma membrane, as well as membranes of cytoplasmic organelles, of the pathogenic protozoan Trichomonas vaginalis. Rosettes formed by 4 to 14 intramembranous particles were seen on the fracture faces of the membrane lining the anterior flagella as well as in fracture faces of the plasma membrane enclosing the anterior region of the protozoan and in cytoplasmic organelles. Special organization of the membrane particles were also seen in the region of association of the recurrent flagellum to the cell body.

  7. Fractures (Broken Bones): First Aid

    Science.gov (United States)

    First aid Fractures (broken bones) Fractures (broken bones): First aid By Mayo Clinic Staff A fracture is a ... 10, 2018 Original article: http://www.mayoclinic.org/first-aid/first-aid-fractures/basics/ART-20056641 . Mayo Clinic ...

  8. Principles and practice of sonography

    International Nuclear Information System (INIS)

    Fleischer, A.C.; James, A.E.

    1987-01-01

    This book is a text of sonographic technique, emphasizing clinical and diagnostic procedures. Ultrasound images and explanatory line drawings are placed side-by-side to facilitate interpretation. This book covers instrumentation and scanning principles, obstetric, gynecologic, abdominal, renal and urologic, pediatric, plus superficial structure sonography

  9. Fracture toughness correlations

    International Nuclear Information System (INIS)

    Wallin, Kim

    1986-09-01

    In this study existing fracture parameter correlations are reviewed. Their applicability and reliability are discussed in detail. A new K IC -CVN-correlation, based on a theoretical brittle fracture model, is presented

  10. Rib fracture - aftercare

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/patientinstructions/000539.htm Rib fracture - aftercare To use the sharing features on this page, please enable JavaScript. A rib fracture is a crack or break in one or ...

  11. Sprains, Strains and Fractures

    Science.gov (United States)

    ... fractures. Many fractures and sprains occur during sports. Football players are particularly vulnerable to foot and ankle ... feet and ankles and take a complete medical history. He or she will also order tests, including ...

  12. Infant skull fracture (image)

    Science.gov (United States)

    Skull fractures may occur with head injuries. Although the skull is both tough and resilient and provides excellent ... or blow can result in fracture of the skull and may be accompanied by injury to the ...

  13. Ankle fracture - aftercare

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/patientinstructions/000548.htm Ankle fracture - aftercare To use the sharing features on this page, please enable JavaScript. An ankle fracture is a break in 1 or more ankle ...

  14. Fracture flow code

    International Nuclear Information System (INIS)

    Dershowitz, W; Herbert, A.; Long, J.

    1989-03-01

    The hydrology of the SCV site will be modelled utilizing discrete fracture flow models. These models are complex, and can not be fully cerified by comparison to analytical solutions. The best approach for verification of these codes is therefore cross-verification between different codes. This is complicated by the variation in assumptions and solution techniques utilized in different codes. Cross-verification procedures are defined which allow comparison of the codes developed by Harwell Laboratory, Lawrence Berkeley Laboratory, and Golder Associates Inc. Six cross-verification datasets are defined for deterministic and stochastic verification of geometric and flow features of the codes. Additional datasets for verification of transport features will be documented in a future report. (13 figs., 7 tabs., 10 refs.) (authors)

  15. Return to sports after ankle fractures: a systematic review.

    Science.gov (United States)

    Del Buono, Angelo; Smith, Rebecca; Coco, Manuela; Woolley, Laurence; Denaro, Vincenzo; Maffulli, Nicola

    2013-01-01

    This review aims to provide information on the time athletes will take to resume sports activity following ankle fractures. We systematically searched Medline (PubMED), EMBASE, CINHAL, Cochrane, Sports Discus and Google scholar databases using the combined keywords 'ankle fractures', 'ankle injuries', 'athletes', 'sports', 'return to sport', 'recovery', 'operative fixation', 'pinning', 'return to activity' to identify articles published in English, Spanish, French, Portuguese and Italian. Seven retrospective studies fulfilled our inclusion criteria. Of the 793 patients, 469 (59%) were males and 324 (41%) were females, and of the 356 ankle fractures we obtained information on, 338 were acute and 18 stress fractures. The general principles were to undertake open reduction and internal fixation of acute fractures, and manage stress fractures conservatively unless a thin fracture line was visible on radiographs. The best timing to return to sports after an acute ankle fracture is still undefined, given the heterogeneity of the outcome measures and results. The time to return to sports after an acute stress injury ranged from 3 to 51 weeks. When facing athletes with ankle fractures, associated injuries have to be assessed and addressed to improve current treatment lines and satisfy future expectancies. The best timing to return to sports after an ankle fracture has not been established yet. The ideas of the return to activity parameter and surgeon databases including sports-related information could induce research to progress.

  16. Atraumatic First Rib Fracture

    OpenAIRE

    Koray Aydogdu

    2014-01-01

    Rib fractures are usually seen after a trauma, while atraumatic spontaneous rib fractures are quite rare. A first rib fracture identified in our 17 years old female patient who had not a history of trauma except lifting a heavy weight was examined in details in terms of the potential complications and followed-up for a long time. We presented our experience on this case with atraumatic first rib fracture that has different views for the etiology in light of the literature.

  17. Fracture Union in Closed Interlocking Nail in Femoral Fracture

    Directory of Open Access Journals (Sweden)

    R L Sahu

    2010-09-01

    Full Text Available INTRODUCTION: Fractures shaft femur is a major cause of morbidity and mortality in patients with lower extremity injuries. The objective of this study was to find out the outcome of Interlocking nail in fracture femur. METHODS: This study was conducted in the Department of Orthopaedic surgery in M. M. Medical College from July 2006 to November 2008. Seventy eight patients were recruited from Emergency and out patient department having closed fracture of femoral shaft. All patients were operated under general or spinal anesthesia. All patients were followed for nine months. RESULTS: Out of seventy eight patients, sixty nine patients underwent union in 90 to 150 days with a mean of 110.68 days. Touch down weight bearing was started on 2nd post-operative day. Complications found in four patients who had non-union, and five patients had delayed union which was treated with dynamization and bone graft. The results were excellent in 88.46% and good in 6.41% patients. CONCLUSIONS: We concluded that this technique is advantageous because of early mobilization (early weight bearing, less complication with good results and is economical. Keywords: close reamed interlocking nail, dynamization, femoral shaft fractures, union

  18. An Improved SPH Technique for Fracture Modeling

    National Research Council Canada - National Science Library

    Libersky, Larry

    2000-01-01

    .... With these improvements, the MAGI code could solve the enormously complex problem of simulating Behind-Armor-Debris and subsequent interaction of the spall cloud with threat target components as well...

  19. Current Concepts in the Mandibular Condyle Fracture Management Part I: Overview of Condylar Fracture

    Science.gov (United States)

    Yang, Jung-Dug; Chung, Ho-Yun; Cho, Byung-Chae

    2012-01-01

    The incidence of condylar fractures is high, but the management of fractures of the mandibular condyle continues to be controversial. Historically, maxillomandibular fixation, external fixation, and surgical splints with internal fixation systems were the techniques commonly used in the treatment of the fractured mandible. Condylar fractures can be extracapsular or intracapsular, undisplaced, deviated, displaced, or dislocated. Treatment depends on the age of the patient, the co-existence of other mandibular or maxillary fractures, whether the condylar fracture is unilateral or bilateral, the level and displacement of the fracture, the state of dentition and dental occlusion, and the surgeonnds on the age of the patient, the co-existence of othefrom which it is difficult to recover aesthetically and functionally;an appropriate treatment is required to reconstruct the shape and achieve the function ofthe uninjured status. To do this, accurate diagnosis, appropriate reduction and rigid fixation, and complication prevention are required. In particular, as mandibular condyle fracture may cause long-term complications such as malocclusion, particularly open bite, reduced posterior facial height, and facial asymmetry in addition to chronic pain and mobility limitation, great caution should be taken. Accordingly, the authors review a general overview of condyle fracture. PMID:22872830

  20. Current Concepts in the Mandibular Condyle Fracture Management Part I: Overview of Condylar Fracture

    Directory of Open Access Journals (Sweden)

    Kang-Young Choi

    2012-07-01

    Full Text Available The incidence of condylar fractures is high, but the management of fractures of the mandibular condyle continues to be controversial. Historically, maxillomandibular fixation, external fixation, and surgical splints with internal fixation systems were the techniques commonly used in the treatment of the fractured mandible. Condylar fractures can be extracapsular or intracapsular, undisplaced, deviated, displaced, or dislocated. Treatment depends on the age of the patient, the co-existence of other mandibular or maxillary fractures, whether the condylar fracture is unilateral or bilateral, the level and displacement of the fracture, the state of dentition and dental occlusion, and the surgeonnds on the age of the patient, the co-existence of othefrom which it is difficult to recover aesthetically and functionally;an appropriate treatment is required to reconstruct the shape and achieve the function ofthe uninjured status. To do this, accurate diagnosis, appropriate reduction and rigid fixation, and complication prevention are required. In particular, as mandibular condyle fracture may cause long-term complications such as malocclusion, particularly open bite, reduced posterior facial height, and facial asymmetry in addition to chronic pain and mobility limitation, great caution should be taken. Accordingly, the authors review a general overview of condyle fracture.

  1. Current Concepts in the Mandibular Condyle Fracture Management Part I: Overview of Condylar Fracture

    Directory of Open Access Journals (Sweden)

    Kang-Young Choi

    2012-07-01

    Full Text Available The incidence of condylar fractures is high,but the management of fractures of the mandibularcondyle continues to be controversial. Historically, maxillomandibular fixation, externalfixation, and surgical splints with internal fixation systems were the techniques commonlyused in the treatment of the fractured mandible. Condylar fractures can be extracapsularor intracapsular, undisplaced, deviated, displaced, or dislocated. Treatment depends on theage of the patient, the co-existence of other mandibular or maxillary fractures, whether thecondylar fracture is unilateral or bilateral, the level and displacement of the fracture, thestate of dentition and dental occlusion, and the surgeonnds on the age of the patient, theco-existence of othefrom which it is difficult to recover aesthetically and functionally;anappropriate treatment is required to reconstruct the shape and achieve the function oftheuninjured status. To do this, accurate diagnosis, appropriate reduction and rigid fixation, andcomplication prevention are required. In particular, as mandibular condyle fracture may causelong-term complications such as malocclusion, particularly open bite, reduced posterior facialheight, and facial asymmetry in addition to chronic pain and mobility limitation, great cautionshould be taken. Accordingly, the authors review a general overview of condyle fracture.

  2. Modified tension band wiring of medial malleolar ankle fractures.

    Science.gov (United States)

    Georgiadis, G M; White, D B

    1995-02-01

    Twenty-two displaced medial malleolar ankle fractures that were treated surgically using the modified tension band method of Cleak and Dawson were retrospectively reviewed at an average follow-up of 25 months. The technique involves the use of a screw to anchor a figure-of-eight wire. There were no malreductions and all fractures healed. Problems with the technique included technical errors with hardware placement, medial ankle pain, and asymptomatic wire migration. Despite this, modified tension band wiring remains an acceptable method for fixation of selected displaced medial malleolar fractures. It is especially suited for small fracture fragments and osteoporotic bone.

  3. Metatarsal stress fractures - aftercare

    Science.gov (United States)

    ... Metatarsal stress fracture. In: Safran MR, Zachazewski J, Stone DA, eds. Instructions for Sports Medicine Patients . 2nd ed. Elsevier Saunders; 2012:648-652. Smith MS. Metatarsal fractures. In: Eiff PM, Hatch R, eds. Fracture Management for Primary Care . 3rd ed. ...

  4. Relationships between fractures

    Science.gov (United States)

    Peacock, D. C. P.; Sanderson, D. J.; Rotevatn, A.

    2018-01-01

    Fracture systems comprise many fractures that may be grouped into sets based on their orientation, type and relative age. The fractures are often arranged in a network that involves fracture branches that interact with one another. Interacting fractures are termed geometrically coupled when they share an intersection line and/or kinematically coupled when the displacements, stresses and strains of one fracture influences those of the other. Fracture interactions are characterised in terms of the following. 1) Fracture type: for example, whether they have opening (e.g., joints, veins, dykes), closing (stylolites, compaction bands), shearing (e.g., faults, deformation bands) or mixed-mode displacements. 2) Geometry (e.g., relative orientations) and topology (the arrangement of the fractures, including their connectivity). 3) Chronology: the relative ages of the fractures. 4) Kinematics: the displacement distributions of the interacting fractures. It is also suggested that interaction can be characterised in terms of mechanics, e.g., the effects of the interaction on the stress field. It is insufficient to describe only the components of a fracture network, with fuller understanding coming from determining the interactions between the different components of the network.

  5. Obesity and fracture risk

    OpenAIRE

    Gonnelli, Stefano; Caffarelli, Carla; Nuti, Ranuccio

    2014-01-01

    Obesity and osteoporosis are two common diseases with an increasing prevalence and a high impact on morbidity and mortality. Obese women have always been considered protected against osteoporosis and osteoporotic fractures. However, several recent studies have challenged the widespread belief that obesity is protective against fracture and have suggested that obesity is a risk factor for certain fractures.

  6. Imaging of insufficiency fractures

    Energy Technology Data Exchange (ETDEWEB)

    Krestan, Christian [Department of Radiology, Medical University of Vienna, Vienna General Hospital, Waehringerstr. 18-20, 1090 Vienna (Austria)], E-mail: christian.krestan@meduniwien.ac.at; Hojreh, Azadeh [Department of Radiology, Medical University of Vienna, Vienna General Hospital, Waehringerstr. 18-20, 1090 Vienna (Austria)

    2009-09-15

    This review focuses on the occurrence, imaging and differential diagnosis of insufficiency fractures. Prevalence, the most common sites of insufficiency fractures and their clinical implications are discussed. Insufficiency fractures occur with normal stress exerted on weakened bone. Postmenopausal osteoporosis is the most common cause of insufficiency fractures. Other conditions which affect bone turnover include osteomalacia, hyperparathyroidism, chronic renal failure and high-dose glucocorticoid therapy. It is a challenge for the radiologist to detect and diagnose insufficiency fractures, and to differentiate them from other bone lesions. Radiographs are still the most widely used imaging method for identification of insufficiency fractures, but sensitivity is limited, depending on the location of the fractures. Magnetic resonance imaging (MRI) is a very sensitive tool to visualize bone marrow abnormalities associated with insufficiency fractures. Thin section, multi-detector computed tomography (MDCT) depicts subtle fracture lines allowing direct visualization of cortical and trabecular bone. Bone scintigraphy still plays a role in detecting fractures, with good sensitivity but limited specificity. The most important differential diagnosis is underlying malignant disease leading to pathologic fractures. Bone densitometry and clinical history may also be helpful in confirming the diagnosis of insufficiency fractures.

  7. Physical Properties of Fractured Porous Media

    Science.gov (United States)

    Mohammed, T. E.; Schmitt, D. R.

    2015-12-01

    The effect of fractures on the physical properties of porous media is of considerable interest to oil and gas exploration as well as enhanced geothermal systems and carbon capture and storage. This work represents an attempt to study the effect fractures have on multiple physical properties of rocks. An experimental technique to make simultaneous electric and ultrasonic measurements on cylindrical core plugs is developed. Aluminum end caps are mounted with ultrasonic transducers to transmit pules along the axis of the cylinder while non-polarizing electrodes are mounted on the sides of the core to make complex conductivity measurements perpendicular to the cylinder axis. Electrical measurements are made by applying a sinusoidal voltage across the measurement circuit that consist of a resister and the sample in series. The magnitude and phase of the signal across the sample is recorded relative to the input signal across a range of frequencies. Synthetic rock analogs are constructed using sintered glass beads with fractures imbedded in them. The fracture location, size and orientation are controlled and each fractured specimen has an unfractured counterpart. Porosity, Permeability, electrical conductivity and ultrasonic velocity measurements are conducted on each sample with the complex electrical conductivities recorded at frequencies from 10hz to 1 Mhz. These measurements allow us to examine the changes induced by these mesoscale fractures on the embedding porous medium. Of particular interest is the effect of fracture orientation on electrical conductivity of the rock. Seismic anisotropy caused by fractures is a well understood phenomenon with many rock physics models dedicated to its understanding. The effect of fractures on electrical conductivity is less well understood with electrical anisotropy scarcely investigated in the literature. None the less, using electrical conductivity to characterize fractures can add an extra constraint to characterization based

  8. Gas-driven fracture propagation

    International Nuclear Information System (INIS)

    Nilson, R.H.

    1981-10-01

    A one-dimensional gas-flow drives a wedge-shaped fracture into a linearly elastic, impermeable half-space which is in uniform compression, sigma/sub infinity/, at infinity. Under a constant driving pressure, p 0 , the fracture/flow system accelerates through a sequence of three self-similar asymptotic regimes (laminar, turbulent, inviscid) in which the fracture grows like an elementary function of time (exponential, near-unity power, and linear; respectively). In each regime, the transport equations are reducible under a separation-of-variables transformation. The integro-differential equations which describe the viscous flows are solved by iterative shooting-methods using expansion techniques to accommodate a zero-pressure singularity at the leading edge of the flow. These numerical results are complemented by an asymptotic analysis for large pressure ratio (N = p 0 /sigma/sub infinity/ → infinity) which exploits the disparity between the fracture-length and penetration-length of the flow. The considered prototypic problem has geologic applications: containment evaluation of underground nuclear tests, explosive stimulation of oil and gas wells, and explosive permeability-enhancement prior to in-situ combustion of coal or oil-shale

  9. [A method for inducing standardized spiral fractures of the tibia in the animal experiment].

    Science.gov (United States)

    Seibold, R; Schlegel, U; Cordey, J

    1995-07-01

    A method for the deliberate weakening of cortical bone has been developed on the basis of an already established technique for creating butterfly fractures. It enables one to create the same type of fracture, i.e., a spiral fracture, every time. The fracturing process is recorded as a force-strain curve. The results of the in vitro investigations form a basis for the preparation of experimental tasks aimed at demonstrating internal fixation techniques and their influence on the vascularity of the bone in simulated fractures. Animal protection law lays down that this fracture model must not fail in animal experiments.

  10. The application of positron emission tomography to the study of mass transfer in fractured rock

    International Nuclear Information System (INIS)

    Gilling, D.; Jefferies, N.L.; Fowles, P.; Hawkesworth, M.R.; Parker, D.J.

    1991-06-01

    Water flow in hard rocks takes place dominantly in fractures. In order to predict the transport of dissolved radioelements through a fractured rock it is necessary to determine both the geometry of the fracture network and the hydraulic properties of the individual fractures. This paper describes a technique for studying mass transfer in a single fracture. The technique is positron emission tomography (PET) and it offers the potential for visualising quantitatively the migration of dissolved tracers. Preliminary experiments have been undertaken involving the flow of Na-22 and F-18 labelled solutions through artificial fractures. The results demonstrate that PET is well suited to this application. (author)

  11. Effect of Random Natural Fractures on Hydraulic Fracture Propagation Geometry in Fractured Carbonate Rocks

    Science.gov (United States)

    Liu, Zhiyuan; Wang, Shijie; Zhao, Haiyang; Wang, Lei; Li, Wei; Geng, Yudi; Tao, Shan; Zhang, Guangqing; Chen, Mian

    2018-02-01

    Natural fractures have a significant influence on the propagation geometry of hydraulic fractures in fractured reservoirs. True triaxial volumetric fracturing experiments, in which random natural fractures are created by placing cement blocks of different dimensions in a cuboid mold and filling the mold with additional cement to create the final test specimen, were used to study the factors that influence the hydraulic fracture propagation geometry. These factors include the presence of natural fractures around the wellbore, the dimension and volumetric density of random natural fractures and the horizontal differential stress. The results show that volumetric fractures preferentially formed when natural fractures occurred around the wellbore, the natural fractures are medium to long and have a volumetric density of 6-9%, and the stress difference is less than 11 MPa. The volumetric fracture geometries are mainly major multi-branch fractures with fracture networks or major multi-branch fractures (2-4 fractures). The angles between the major fractures and the maximum horizontal in situ stress are 30°-45°, and fracture networks are located at the intersections of major multi-branch fractures. Short natural fractures rarely led to the formation of fracture networks. Thus, the interaction between hydraulic fractures and short natural fractures has little engineering significance. The conclusions are important for field applications and for gaining a deeper understanding of the formation process of volumetric fractures.

  12. Llizarov technique

    International Nuclear Information System (INIS)

    Shankman, S.; Rosenberg, Z.S.; Frankel, V.; Golyakhovsky, V.

    1990-01-01

    This paper illustrates the radiographic manifestations of the Ilizarov distraction technique for the correction of short and deformed limbs. The radiographs of 130 patients who underwent Ilizarov distraction at 160 sites since December 1986 were reviewed retrospectively. Reasons for correction included fracture nonunion and malunion idiopathic leg length discrepancy, achondroplasia, and neurofibromatosis with tibial pseudarthrosis. Ninety patients were adults, and 40 were children. In order to assess cortical bone development during the fixation phase, CT of the regenerate bone was performed in 17 patients. Conventional tomograms were obtained in 20 patients for the evaluation of delayed or hypoplastic union at the distraction site

  13. Current management of posterior wall fractures of the acetabulum.

    Science.gov (United States)

    Moed, Berton R; Kregor, Philip J; Reilly, Mark C; Stover, Michael D; Vrahas, Mark S

    2015-01-01

    The general goals for treating an acetabular fracture are to restore congruity and stability of the hip joint. These goals are no different from those for the subset of fractures of the posterior wall. Nevertheless, posterior wall fractures present unique problems compared with other types of acetabular fractures. Successful treatment of these fractures depends on a multitude of factors. The physician must understand their distinctive radiologic features, in conjunction with patient factors, to determine the appropriate treatment. By knowing the important points of posterior surgical approaches to the hip, particularly the posterior wall, specific techniques can be used for fracture reduction and fixation in these often challenging fractures. In addition, it is important to develop a complete grasp of potential complications and their treatment. The evaluation and treatment protocols initially developed by Letournel and Judet continue to be important; however, the surgeon also should be aware of new information published and presented in the past decade.

  14. Advanced hydraulic fracturing methods to create in situ reactive barriers

    International Nuclear Information System (INIS)

    Murdoch, L.

    1997-01-01

    This article describes the use of hydraulic fracturing to increase permeability in geologic formations where in-situ remedial action of contaminant plumes will be performed. Several in-situ treatment strategies are discussed including the use of hydraulic fracturing to create in situ redox zones for treatment of organics and inorganics. Hydraulic fracturing methods offer a mechanism for the in-situ treatment of gently dipping layers of reactive compounds. Specialized methods using real-time monitoring and a high-energy jet during fracturing allow the form of the fracture to be influenced, such as creation of assymmetric fractures beneath potential sources (i.e. tanks, pits, buildings) that should not be penetrated by boring. Some examples of field applications of this technique such as creating fractures filled with zero-valent iron to reductively dechlorinate halogenated hydrocarbons, and the use of granular activated carbon to adsorb compounds are discussed

  15. Role of MRI in hip fractures, including stress fractures, occult fractures, avulsion fractures

    International Nuclear Information System (INIS)

    Nachtrab, O.; Cassar-Pullicino, V.N.; Lalam, R.; Tins, B.; Tyrrell, P.N.M.; Singh, J.

    2012-01-01

    MR imaging plays a vital role in the diagnosis and management of hip fractures in all age groups, in a large spectrum of patient groups spanning the elderly and sporting population. It allows a confident exclusion of fracture, differentiation of bony from soft tissue injury and an early confident detection of fractures. There is a spectrum of MR findings which in part is dictated by the type and cause of the fracture which the radiologist needs to be familiar with. Judicious but prompt utilisation of MR in patients with suspected hip fractures has a positive therapeutic impact with healthcare cost benefits as well as social care benefits.

  16. [Principles of PET].

    Science.gov (United States)

    Beuthien-Baumann, B

    2018-05-01

    Positron emission tomography (PET) is a procedure in nuclear medicine, which is applied predominantly in oncological diagnostics. In the form of modern hybrid machines, such as PET computed tomography (PET/CT) and PET magnetic resonance imaging (PET/MRI) it has found wide acceptance and availability. The PET procedure is more than just another imaging technique, but a functional method with the capability for quantification in addition to the distribution pattern of the radiopharmaceutical, the results of which are used for therapeutic decisions. A profound knowledge of the principles of PET including the correct indications, patient preparation, and possible artifacts is mandatory for the correct interpretation of PET results.

  17. Principles of asymmetric synthesis

    CERN Document Server

    Gawley, Robert E; Aube, Jeffrey

    2012-01-01

    The world is chiral. Most of the molecules in it are chiral, and asymmetric synthesis is an important means by which enantiopure chiral molecules may be obtained for study and sale. Using examples from the literature of asymmetric synthesis, this book presents a detailed analysis of the factors that govern stereoselectivity in organic reactions. After an explanation of the basic physical-organic principles governing stereoselective reactions, the authors provide a detailed, annotated glossary of stereochemical terms. A chapter on "Practical Aspects of Asymmetric Synthesis" provides a critical overview of the most common methods for the preparation of enantiomerically pure compounds, techniques for analysis of stereoisomers using chromatographic, spectroscopic, and chiroptical methods. The authors then present an overview of the most important methods in contemporary asymmetric synthesis organized by reaction type. Thus, there are four chapters on carbon-carbon bond forming reactions, one chapter on reductions...

  18. Principles & practice of physics

    CERN Document Server

    Mazur, Eric; Dourmashkin, Peter A; Pedigo, Daryl; Bieniek, Ronald J

    2015-01-01

    Putting physics first Based on his storied research and teaching, Eric Mazur's Principles & Practice of Physics builds an understanding of physics that is both thorough and accessible. Unique organization and pedagogy allow you to develop a true conceptual understanding of physics alongside the quantitative skills needed in the course. *New learning architecture: The book is structured to help you learn physics in an organized way that encourages comprehension and reduces distraction.*Physics on a contemporary foundation: Traditional texts delay the introduction of ideas that we now see as unifying and foundational. This text builds physics on those unifying foundations, helping you to develop an understanding that is stronger, deeper, and fundamentally simpler.*Research-based instruction: This text uses a range of research-based instructional techniques to teach physics in the most effective manner possible. The result is a groundbreaking book that puts physics first, thereby making it more accessible to...

  19. Principles of modern digital design

    CERN Document Server

    Lala, Parag K

    2007-01-01

    A major objective of this book is to fill the gap between traditional logic design principles and logic design/optimization techniques used in practice. Over the last two decades several techniques for computer-aided design and optimization of logic circuits have been developed. However, underlying theories of these techniques are inadequately covered or not covered at all in undergraduate text books. This book covers not only the ""classical"" material found in current text books but also selected materials that modern logic designers need to be familiar with.

  20. Orbital fractures: a review

    Directory of Open Access Journals (Sweden)

    Jeffrey M Joseph

    2011-01-01

    Full Text Available Jeffrey M Joseph, Ioannis P GlavasDivision of Ophthalmic Plastic and Reconstructive Surgery, Department of Ophthalmology, School of Medicine, New York University, New York, NY, USA; Manhattan Eye, Ear, and Throat Hospital, New York, NY, USAAbstract: This review of orbital fractures has three goals: 1 to understand the clinically relevant orbital anatomy with regard to periorbital trauma and orbital fractures, 2 to explain how to assess and examine a patient after periorbital trauma, and 3 to understand the medical and surgical management of orbital fractures. The article aims to summarize the evaluation and management of commonly encountered orbital fractures from the ophthalmologic perspective and to provide an overview for all practicing ophthalmologists and ophthalmologists in training.Keywords: orbit, trauma, fracture, orbital floor, medial wall, zygomatic, zygomatic complex, zmc fracture, zygomaticomaxillary complex fractures 

  1. Mechanics of Hydraulic Fractures

    Science.gov (United States)

    Detournay, Emmanuel

    2016-01-01

    Hydraulic fractures represent a particular class of tensile fractures that propagate in solid media under pre-existing compressive stresses as a result of internal pressurization by an injected viscous fluid. The main application of engineered hydraulic fractures is the stimulation of oil and gas wells to increase production. Several physical processes affect the propagation of these fractures, including the flow of viscous fluid, creation of solid surfaces, and leak-off of fracturing fluid. The interplay and the competition between these processes lead to multiple length scales and timescales in the system, which reveal the shifting influence of the far-field stress, viscous dissipation, fracture energy, and leak-off as the fracture propagates.

  2. Fracture in Soft Materials

    DEFF Research Database (Denmark)

    Hassager, Ole

    Fracture is a phenomenon that is generally associated with solids. A key element in fracture theory is the so-called weakest link idea that fracture initiates from the largest pre-existing material imperfection. However, recent work has demonstrated that fracture can also happen in liquids, where...... surface tension will act to suppress such imperfections. Therefore, the weakest link idea does not seem immediately applicable to fracture in liquids. This presentation will review fracture in liquids and argue that fracture in soft liquids is a material property independent of pre-existing imperfections....... The following questions then emerge: What is the material description needed to predict crack initiation, crack speed and crack shape in soft materials and liquids....

  3. Stress fractures in the lower extremity

    International Nuclear Information System (INIS)

    Berger, Ferco H.; Jonge, Milko C. de; Maas, Mario

    2007-01-01

    Stress fractures are fatigue injuries of bone usually caused by changes in training regimen in the population of military recruits and both professional and recreational athletes. Raised levels of sporting activity in today's population and refined imaging technologies have caused a rise in reported incidence of stress fractures in the past decades, now making up more than 10% of cases in a typical sports medicine practice. Background information (including etiology, epidemiology, clinical presentation and treatment and prevention) as well as state of the art imaging of stress fractures will be discussed to increase awareness amongst radiologists, providing the tools to play an important role in diagnosis and prognosis of stress fractures. Specific fracture sites in the lower extremity will be addressed, covering the far majority of stress fracture incidence. Proper communication between treating physician, physical therapist and radiologist is needed to obtain a high index of suspicion for this easily overlooked entity. Radiographs are not reliable for detection of stress fractures and radiologist should not falsely be comforted by them, which could result in delayed diagnosis and possibly permanent consequences for the patient. Although radiographs are mandatory to rule out differentials, they should be followed through when negative, preferably by magnetic resonance imaging (MRI), as this technique has proven to be superior to bone scintigraphy. CT can be beneficial in a limited number of patients, but should not be used routinely

  4. Treatment of root fracture with accompanying resorption using cermet cement.

    Science.gov (United States)

    Lui, J L

    1992-02-01

    A method of treating an apical root fracture with accompanying resorption at the junction of the fracture fragments using glass-cermet cement is described. Endodontically, the material had previously been used for repair of lateral resorptive root defects and retrograde root fillings. Complete bone regeneration was observed three years post-operatively following treatment of the root fracture in the conventional manner. The various advantages of glass-cermet cement as a root filling material used in the technique described are discussed.

  5. Hemiarthroplasty for proximal humeral fracture: restoration of the Gothic arch.

    Science.gov (United States)

    Krishnan, Sumant G; Bennion, Phillip W; Reineck, John R; Burkhead, Wayne Z

    2008-10-01

    Proximal humerus fractures are the most common fractures of the shoulder girdle, and initial management of these injuries often determines final outcome. When arthroplasty is used to manage proximal humeral fractures, surgery remains technically demanding, and outcomes have been unpredictable. Recent advances in both technique and prosthetic implants have led to more successful and reproducible results. Key technical points include restoration of the Gothic arch, anatomic tuberosity reconstruction, and minimal soft tissue dissection.

  6. Technical considerations for surgical intervention of Jones fractures.

    Science.gov (United States)

    Mendicino, Robert W; Hentges, Matthew J; Mendicino, Michael R; Catanzariti, Alan R

    2013-01-01

    Jones fractures are a common injury treated by foot and ankle surgeons. Surgical intervention is recommended because of the high rate of delayed union, nonunion, and repeat fracture, when treated conservatively. Percutaneous intramedullary screw fixation is commonly used in the treatment of these fractures. We present techniques that can increase the surgical efficiency and decrease the complications associated with percutaneous delivery of internal fixation. Copyright © 2013 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

  7. Novel Therapeutic Strategy for the Prevention of Bone Fractures

    Science.gov (United States)

    2014-08-01

    increased risk of falls and fractures. 3 Moreover, muscle paralysis using agents such as botulinum toxin induces bone loss 4 and impairs fracture...caused by botulinum toxin -A local injection impairs fracture healing in the rat femur . J Orthop Res 2012 ; 30 : 574 – 580 . 6 . Elkasrawy MN...Techniques 5 kg load cell. Structural, or extrinsic, properties including ultimate force (Fu; height of curve) and stiffness (S; slope of curve) were

  8. An efficient hydro-mechanical model for coupled multi-porosity and discrete fracture porous media

    Science.gov (United States)

    Yan, Xia; Huang, Zhaoqin; Yao, Jun; Li, Yang; Fan, Dongyan; Zhang, Kai

    2018-02-01

    In this paper, a numerical model is developed for coupled analysis of deforming fractured porous media with multiscale fractures. In this model, the macro-fractures are modeled explicitly by the embedded discrete fracture model, and the supporting effects of fluid and fillings in these fractures are represented explicitly in the geomechanics model. On the other hand, matrix and micro-fractures are modeled by a multi-porosity model, which aims to accurately describe the transient matrix-fracture fluid exchange process. A stabilized extended finite element method scheme is developed based on the polynomial pressure projection technique to address the displacement oscillation along macro-fracture boundaries. After that, the mixed space discretization and modified fixed stress sequential implicit methods based on non-matching grids are applied to solve the coupling model. Finally, we demonstrate the accuracy and application of the proposed method to capture the coupled hydro-mechanical impacts of multiscale fractures on fractured porous media.

  9. Dry fracture method for simultaneous measurement of in-situ stress state and material properties

    International Nuclear Information System (INIS)

    Serata, S.; Oka, S.; Kikuchi, S.

    1996-01-01

    Based on the dry fracture principle, a computerized borehole probe has been developed to measure stress state and material properties, simultaneously. The probe is designed to obtain a series of measurements in a continuing sequence along a borehole length, without any interruptive measures, such as resetting packers, taking indentation of borehole wall, overcoming, etc. The new dry fracture probe for the single fracture method is designed to overcome the difficulties posed by its ancestor which was based on the double fracture method. The accuracy of the single fracture method is confirmed by a close agreement with the theory, FE modeling and laboratory testing

  10. A New Tree-Type Fracturing Method for Stimulating Coal Seam Gas Reservoirs

    Directory of Open Access Journals (Sweden)

    Qian Li

    2017-09-01

    Full Text Available Hydraulic fracturing is used widely to stimulate coalbed methane production in coal mines. However, some factors associated with conventional hydraulic fracturing, such as the simple morphology of the fractures it generates and inhomogeneous stress relief, limit its scope of application in coal mines. These problems mean that gas extraction efficiency is low. Conventional fracturing may leave hidden pockets of gas, which will be safety hazards for subsequent coal mining operations. Based on a new drilling technique applicable to drilling boreholes in coal seams, this paper proposes a tree-type fracturing technique for stimulating reservoir volumes. Tree-type fracturing simulation experiments using a large-scale triaxial testing apparatus were conducted in the laboratory. In contrast to the single hole drilled for conventional hydraulic fracturing, the tree-type sub-boreholes induce radial and tangential fractures that form complex fracture networks. These fracture networks can eliminate the “blank area” that may host dangerous gas pockets. Gas seepage in tree-type fractures was analyzed, and gas seepage tests after tree-type fracturing showed that permeability was greatly enhanced. The equipment developed for tree-type fracturing was tested in the Fengchun underground coal mine in China. After implementing tree-type fracturing, the gas extraction rate was around 2.3 times greater than that for traditional fracturing, and the extraction rate remained high for a long time during a 30-day test. This shortened the gas drainage time and improved gas extraction efficiency.

  11. Disposal of waste by hydraulic fracturing

    International Nuclear Information System (INIS)

    Tamura, T.; Weeren, H.

    1984-01-01

    Liquid radioactive waste solutions at the Oak Ridge National Laboratory (ORNL) have been disposed of for nearly 20 years by preparing a slurry, injecting it into bedding plane fractures formed in low-permeability shale, and allowing the slurry to set into a solid. Three major considerations are required for this method: a rock formation that forms horizontal or bedding plane fractures and is highly impermeable, a plant facility that can develop sufficient hydraulic pressure to fracture the rock and to inject the slurry, and a slurry that can be pumped into the fracture and that will set, preferably, into a low-leaching solid. The requirements and desirable conditions of the formation, the process and facility as used for radioactive waste disposal, and the mix formulation and slurry properties that were required for injection and solidification are described. The intent of this paper is to stimulate interest in this technique for possible application to nonnuclear wastes

  12. [Management of disk displacement with condylar fracture].

    Science.gov (United States)

    Yu, Shi-bin; Li, Zu-bing; Yang, Xue-wen; Zhao, Ji-hong; Dong, Yao-jun

    2003-07-01

    To investigate clinical features of disk displacement during the course of condylar fracture and to explore the techniques of disk reposition and suturation. 32 patients (10 females and 22 males) who had disk displacements with condylar fractures were followed up. Reduction and reposition of the dislocated disks simultaneously with fixation of fractures were performed. 7 patients underwent intermaxillary fixation with elastic bands for 1 to 2 weeks. The occlusions were satisfactory in all cases but one for the reason of ramus height loss. No TMJ symptom was found when examined 3 months post operation. Anterior disk displacements were most occurred with high condylar process fractures. Surgical reposition and suturation of disk play an important role for the later TMJ-function.

  13. Illustration of Babinet's principle with ultracold atoms

    OpenAIRE

    Reinhard, Aaron; Riou, Jean-Félix; Zundel, Laura A.; Weiss, David S.

    2013-01-01

    We demonstrate Babinet's principle by the absorption of high intensity light from dense clouds of ultracold atoms. Images of the diffracted light are directly related to the spatial distribution of atoms. The advantages of employing Babinet's principle as an imaging technique are that it is easy to implement and the detected signal is large. We discuss the regimes of applicability of this technique as well as its limitations.

  14. Cone-beam CT in diagnosis of scaphoid fractures

    Energy Technology Data Exchange (ETDEWEB)

    Edlund, Rolf; Lapidus, Gunilla; Baecklund, Jenny [Capio St Goeran' s Hospital, Department of Radiology, Stockholm (Sweden); Skorpil, Mikael [Karolinska University Hospital, Department of Radiology, Stockholm (Sweden); Karolinska Institutet, Department of Molecular Medicine and Surgery, Stockholm (Sweden)

    2016-02-15

    This prospective study investigated the sensitivity of cone beam computed tomography (CBCT), a low dose technique recently made available for extremity examinations, in detecting scaphoid fractures. Magnetic resonance imaging (MRI) was used as gold standard for scaphoid fractures. A total of 95 patients with a clinically suspected scaphoid fracture were examined with radiography and CBCT in the acute setting. A negative CBCT exam was followed by an MRI within 2 weeks. When a scaphoid fracture was detected on MRI a new CBCT was performed. Radiography depicted seven scaphoid fractures, all of which were also seen with CBCT. CBCT detected another four scaphoid fractures. With MRI another five scaphoid fractures were identified that were not seen with radiography or with CBCT. These were also not visible on the reexamination CBCT. Sensitivity for radiography was 44, 95 % confidence interval 21-69 %, and for CBCT 69 %, 95 % confidence interval 41-88 % (p = 0.12). Several non-scaphoid fractures in the carpal region were identified, radiography and CBCT depicted 7 and 34, respectively (p < 0.0001). CBCT is a superior alternative to radiography, entailing more accurate diagnoses of carpal region fractures, and thereby requiring fewer follow-up MRI examinations. However, CBCT cannot be used to exclude scaphoid fractures, since MRI identified additional occult scaphoid fractures. (orig.)

  15. Fracture mechanics behaviour of neutron irradiated Alloy A-286

    International Nuclear Information System (INIS)

    Mills, W.J.; James, L.A.

    The effect of fast-neutron irradiation on the fatigue-crack propagation and fracture toughness behaviour of Alloy A-286 was characterized using fracture mechanics techniques. The fracture toughness was found to decrease continuously with increasing irradiation damage at both 24 deg. C and 427 deg. C. In the unirradiated and low fluence conditions, specimens displayed appreciable plasticity prior to fracture, and equivalent Ksub(Ic) values were determined from Jsub(Ic) fracture toughness results. At high irradiation exposure levels, specimens exhibited a brittle Ksub(Ic) fracture mode. The 427 deg. C fracture toughness fell from 129 MPa√m in the unirradiated condition to 35 MPa√m at an exposure of 16.2 dpa (total fluence of 5.2x10 22 n/cm 2 ). Room temperature fracture toughness values were consistently 40 to 60 percent higher than the 427 deg. C values. Electron fractography revealed that the reduction in fracture resistance was attributed to a fracture mechanism transition from ductile microvoid coalescence to channel fracture. Fatigue-crack propagation tests were conducted at 427 deg. C on specimens irradiated at 2.4 dpa and 16.2 dpa. Crack growth rates at the lower exposure level were comparable to those in unirradiated material, while those at the higher exposure were slightly higher than in unirradiated material. (author)

  16. Fractures of the proximal fifth metatarsal: percutaneous bicortical fixation.

    Science.gov (United States)

    Mahajan, Vivek; Chung, Hyun Wook; Suh, Jin Soo

    2011-06-01

    Displaced intraarticular zone I and displaced zone II fractures of the proximal fifth metatarsal bone are frequently complicated by delayed nonunion due to a vascular watershed. Many complications have been reported with the commonly used intramedullary screw fixation for these fractures. The optimal surgical procedure for these fractures has not been determined. All these observations led us to evaluate the effectiveness of percutaneous bicortical screw fixation for treating these fractures. Twenty-three fractures were operatively treated by bicortical screw fixation. All the fractures were evaluated both clinically and radiologically for the healing. All the patients were followed at 2 or 3 week intervals till fracture union. The patients were followed for an average of 22.5 months. Twenty-three fractures healed uneventfully following bicortical fixation, with a mean healing time of 6.3 weeks (range, 4 to 10 weeks). The average American Orthopaedic Foot & Ankle Society (AOFAS) score was 94 (range, 90 to 99). All the patients reported no pain at rest or during athletic activity. We removed the implant in all cases at a mean of 23.2 weeks (range, 18 to 32 weeks). There was no refracture in any of our cases. The current study shows the effectiveness of bicortical screw fixation for displaced intraarticular zone I fractures and displaced zone II fractures. We recommend it as one of the useful techniques for fixation of displaced zone I and II fractures.

  17. Ballistic fractures: indirect fracture to bone.

    Science.gov (United States)

    Dougherty, Paul J; Sherman, Don; Dau, Nathan; Bir, Cynthia

    2011-11-01

    Two mechanisms of injury, the temporary cavity and the sonic wave, have been proposed to produce indirect fractures as a projectile passes nearby in tissue. The purpose of this study is to evaluate the temporal relationship of pressure waves using strain gauge technology and high-speed video to elucidate whether the sonic wave, the temporary cavity, or both are responsible for the formation of indirect fractures. Twenty-eight fresh frozen cadaveric diaphyseal tibia (2) and femurs (26) were implanted into ordnance gelatin blocks. Shots were fired using 9- and 5.56-mm bullets traversing through the gelatin only, passing close to the edge of the bone, but not touching, to produce an indirect fracture. High-speed video of the impact event was collected at 20,000 frames/s. Acquisition of the strain data were synchronized with the video at 20,000 Hz. The exact time of fracture was determined by analyzing and comparing the strain gauge output and video. Twenty-eight shots were fired, 2 with 9-mm bullets and 26 with 5.56-mm bullets. Eight indirect fractures that occurred were of a simple (oblique or wedge) pattern. Comparison of the average distance of the projectile from the bone was 9.68 mm (range, 3-20 mm) for fractured specimens and 15.15 mm (range, 7-28 mm) for nonfractured specimens (Student's t test, p = 0.036). In this study, indirect fractures were produced after passage of the projectile. Thus, the temporary cavity, not the sonic wave, was responsible for the indirect fractures.

  18. Pediatric femur fractures, epidemiology and treatment

    Directory of Open Access Journals (Sweden)

    Petković Lazar

    2011-01-01

    Full Text Available Background/Aim. Femur fractures in children most often occur as a consequence of traffic accidents, during play and sport activities, and due to different pathological states. Diagnosis is rather simple and it includes physical and radiographycal examination. Femur fractures treatment in children can be operative and unoperative, depending on several facts: age, localisation and type of fracture, joint injuries of soft tissues, the presence of other injuries (in polytrauma, economical and social aspects, ect. The aim of this study was to present epidemiological characteristics of pediatric femur fractures, that is in the stage of development, including a special analysis of the used treatment techniques, as well as the comparison of the obtained data with those from the literature. Methods. The evaluation included following parameters: age, gender, cause, localisation and type of femur fracture, applied treatment and hospitalisation duration. Results. Among the presented 143 patients with femur fracture, 109 were boys and 34 were girls (3.2 : 1 ratio; p = 0.0001. Average age for both genders was 8.6 years, and no difference between boys and girls were found for the age (p = 0.758. In total, the most common fracture was diaphyseal fracture of femur in 93 (65.03% patients. The second was proximal fracture in 30 (20.98% patients, and the last distal fracture of the femur in 20 (13.99% patients (p = 0.0001. Three main causes of femur fracture can be distinguished: during play and sport activities in 67 (46.8% children, in traffic accidents in 64 (44.8% children, and pathological fractures in 12 (8.4% children. Inoperative treatment was applied in 82 (57.3% patients, and operative one in 61 (42.7% patients. The most common tretament was traction, in 71 (49.6% patients, followed by immobilization by hip spica cast mostly in young children. Intramedullar elastic nailing was applied in 16 (11.2% cases, and intramedullar rigid nailing (Küntscher in 19

  19. Hydraulic Fracturing and Production Optimization in Eagle Ford Shale Using Coupled Geomechanics and Fluid Flow Model

    Science.gov (United States)

    Suppachoknirun, Theerapat; Tutuncu, Azra N.

    2017-12-01

    the cumulative production and for the three wells individually. Significant reduction in the production rate in early production times is anticipated in tight reservoirs regardless of the fracturing techniques implemented. The simulations conducted using the alternating fracturing technique led to more oil production than when zipper fracturing was used for a 20-year production period. Yet, due to the decline experienced, the differences in cumulative production get smaller, and the alternating fracturing is not practically implementable while field application of zipper fracturing technique is more practical and widely used.

  20. Compartmentalization analysis using discrete fracture network models

    Energy Technology Data Exchange (ETDEWEB)

    La Pointe, P.R.; Eiben, T.; Dershowitz, W. [Golder Associates, Redmond, VA (United States); Wadleigh, E. [Marathon Oil Co., Midland, TX (United States)

    1997-08-01

    This paper illustrates how Discrete Fracture Network (DFN) technology can serve as a basis for the calculation of reservoir engineering parameters for the development of fractured reservoirs. It describes the development of quantitative techniques for defining the geometry and volume of structurally controlled compartments. These techniques are based on a combination of stochastic geometry, computational geometry, and graph the theory. The parameters addressed are compartment size, matrix block size and tributary drainage volume. The concept of DFN models is explained and methodologies to compute these parameters are demonstrated.