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Sample records for grady fragmentation failure

  1. Impact failure and fragmentation properties of metals

    Energy Technology Data Exchange (ETDEWEB)

    Grady, D.E. [Applied Research Associates, Albuquerque, NM (United States); Kipp, M.E. [Sandia National Labs., Albuquerque, NM (United States)

    1998-03-01

    In the present study we describe the development of an experimental fracture material property test method specific to dynamic fragmentation. Spherical test samples of the metals of interest are subjected to controlled impulsive stress loads by acceleration to high velocities with a light-gas launcher facility and subsequent normal impact on thin plates. Motion, deformation and fragmentation of the test samples are diagnosed with multiple flash radiography methods. The impact plate materials are selected to be transparent to the x-ray method so that only test metal material is imaged. Through a systematic series of such tests both strain-to-failure and fragmentation resistance properties are determined through this experimental method. Fragmentation property data for several steels, copper, aluminum, tantalum and titanium have been obtained to date. Aspects of the dynamic data have been analyzed with computational methods to achieve a better understanding of the processes leading to failure and fragmentation, and to test an existing computational fragmentation model.

  2. Genetic diversity of nifH gene sequences in Paenibacillus azotofixans strains and soil samples analyzed by denaturing gradiënt gel electrophoresis of PCR-amplified gene fragments

    NARCIS (Netherlands)

    Rosado, A.S.; Duarte, G.F.; Seldin, L.; Elsas, van J.D.

    1998-01-01

    The diversity of dinitrogenase reductase gene (nifH) fragments in Paenibacillus azotofixans strains was investigated by using molecular methods. The partial nifH gene sequences of eight P. azotofixans strains, as well as one strain each of the close relatives Paenibacillus durum, Paenibacillus

  3. Sperm DNA fragmentation, recurrent implantation failure and recurrent miscarriage

    Directory of Open Access Journals (Sweden)

    Carol Coughlan

    2015-01-01

    Full Text Available Evidence is increasing that the integrity of sperm DNA may also be related to implantation failure and recurrent miscarriage (RM. To investigate this, the sperm DNA fragmentation in partners of 35 women with recurrent implantation failure (RIF following in vitro fertilization, 16 women diagnosed with RM and seven recent fathers (control were examined. Sperm were examined pre- and post-density centrifugation by the sperm chromatin dispersion (SCD test and the terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL assay. There were no significant differences in the age of either partner or sperm concentration, motility or morphology between three groups. Moreover, there were no obvious differences in sperm DNA fragmentation measured by either test. However, whilst on average sperm DNA fragmentation in all groups was statistically lower in prepared sperm when measured by the SCD test, this was not seen with the results from the TUNEL assay. These results do not support the hypothesis that sperm DNA fragmentation is an important cause of RIF or RM, or that sperm DNA integrity testing has value in such patients. It also highlights significant differences between test methodologies and sperm preparation methods in interpreting the data from sperm DNA fragmentation tests.

  4. Fracture mechanics model of fragmentation

    International Nuclear Information System (INIS)

    Glenn, L.A.; Gommerstadt, B.Y.; Chudnovsky, A.

    1986-01-01

    A model of the fragmentation process is developed, based on the theory of linear elastic fracture mechanics, which predicts the average fragment size as a function of strain rate and material properties. This approach permits a unification of previous results, yielding Griffith's solution in the low-strain-rate limit and Grady's solution at high strain rates

  5. Dynamic Failure and Fragmentation of a Hot-Pressed Boron Carbide

    Science.gov (United States)

    Sano, Tomoko; Vargas-Gonzalez, Lionel; LaSalvia, Jerry; Hogan, James David

    2017-12-01

    This study investigates the failure and fragmentation of a hot-pressed boron carbide during high rate impact experiments. Four impact experiments are performed using a composite-backed target configuration at similar velocities, where two of the impact experiments resulted in complete target penetration and two resulted in partial penetration. This paper seeks to evaluate and understand the dynamic behavior of the ceramic that led to either the complete or partial penetration cases, focusing on: (1) surface and internal failure features of fragments using optical, scanning electron, and transmission electron microscopy, and (2) fragment size analysis using state-of-the-art particle-sizing technology that informs about the consequences of failure. Detailed characterization of the mechanical properties and the microstructure is also performed. Results indicate that transgranular fracture was the primary mode of failure in this boron carbide material, and no stress-induced amorphization features were observed. Analysis of the fragment sizes for the partial and completely penetrated experiments revealed a possible correlation between larger fragment sizes and impact performance. The results will add insight into designing improved advanced ceramics for impact protection applications.

  6. Dolan Grady relations and noncommutative quasi-exactly solvable systems

    Science.gov (United States)

    Klishevich, Sergey M.; Plyushchay, Mikhail S.

    2003-11-01

    We investigate a U(1) gauge invariant quantum mechanical system on a 2D noncommutative space with coordinates generating a generalized deformed oscillator algebra. The Hamiltonian is taken as a quadratic form in gauge covariant derivatives obeying the nonlinear Dolan-Grady relations. This restricts the structure function of the deformed oscillator algebra to a quadratic polynomial. The cases when the coordinates form the {\\mathfrak{su}}(2) and {\\mathfrak{sl}}(2,{\\bb {R}}) algebras are investigated in detail. Reducing the Hamiltonian to 1D finite-difference quasi-exactly solvable operators, we demonstrate partial algebraization of the spectrum of the corresponding systems on the fuzzy sphere and noncommutative hyperbolic plane. A completely covariant method based on the notion of intrinsic algebra is proposed to deal with the spectral problem of such systems.

  7. An endogenously produced fragment of cardiac myosin-binding protein C is pathogenic and can lead to heart failure.

    Science.gov (United States)

    Razzaque, Md Abdur; Gupta, Manish; Osinska, Hanna; Gulick, James; Blaxall, Burns C; Robbins, Jeffrey

    2013-08-16

    A stable 40-kDa fragment is produced from cardiac myosin-binding protein C when the heart is stressed using a stimulus, such as ischemia-reperfusion injury. Elevated levels of the fragment can be detected in the diseased mouse and human heart, but its ability to interfere with normal cardiac function in the intact animal is unexplored. To understand the potential pathogenicity of the 40-kDa fragment in vivo and to investigate the molecular pathways that could be targeted for potential therapeutic intervention. We generated cardiac myocyte-specific transgenic mice using a Tet-Off inducible system to permit controlled expression of the 40-kDa fragment in cardiomyocytes. When expression of the 40-kDa protein is induced by crossing the responder animals with tetracycline transactivator mice under conditions in which substantial quantities approximating those observed in diseased hearts are reached, the double-transgenic mice subsequently experience development of sarcomere dysgenesis and altered cardiac geometry, and the heart fails between 12 and 17 weeks of age. The induced double-transgenic mice had development of cardiac hypertrophy with myofibrillar disarray and fibrosis, in addition to activation of pathogenic MEK-ERK pathways. Inhibition of MEK-ERK signaling was achieved by injection of the mitogen-activated protein kinase (MAPK)/ERK inhibitor U0126. The drug effectively improved cardiac function, normalized heart size, and increased probability of survival. These results suggest that the 40-kDa cardiac myosin-binding protein C fragment, which is produced at elevated levels during human cardiac disease, is a pathogenic fragment that is sufficient to cause hypertrophic cardiomyopathy and heart failure.

  8. Hugh Grady (ed.), Shakespeare and Modernity : Early Modern to Millenium

    OpenAIRE

    Ribeyrol, Wendy

    2014-01-01

    Shakespeare and Modernity : Early Modern to Millenium, publié au tournant du troisième millénaire est un recueil de neuf essais d’universitaires américains et britanniques, précédé d’une introduction de Hugh Grady, auteur par ailleurs de The Modernist Shakespeare (1991), Shakespeare’s Universal Wolf (1996) et plus récemment de Shakespeare and Impure Aesthetics (2009). Ce livre offre à l’étudiant, à l’enseignant et au chercheur un état des lieux stimulant de l’évolution des études shakespearie...

  9. Fragmentation of Ceramics in Rapid Expansion Mode

    Science.gov (United States)

    Maiti, Spandan; Geubelle, Philippe H.; Rangaswamy, Krishnan

    The study of the fragmentation process goes back to more than a century, motivated primarily by problems related to mining and ore handling (Grady and Kipp, 1985). Various theories have been proposed to predict the fragmentation stress and the fragment size and distribution. But the investigations are generally case specific and relate to only a narrow set of fragmentation processes. A number of theoretical studies of dynamic fragmentation in a rapidly expanding body can be found in the literature. For example, the study summarized in (Grady, 1982) presents a model based on a simple energy balance concept between the surface energy released due to fracture and the kinetic energy of the fragments. Subsequent refinements of the energy balance model have been proposed by (Glenn and Chudnovsky, 1986), which take into account the strain energy of the fragments and specify a threshold stress below which no fragmentation occurs. These models assume that the fracture events are instantaneous and occur simultaneously. Evidently, these assumptions are quite restrictive and these models can not take into account the transient nature of the fragmentation process after the onset of fracture in the material. A more recent model proposed by (Miller et al., 1999) however takes into account this time-dependent nature of the fragmentation event and the distribution of flaws of various strengths in the original material.

  10. Dolan-Grady relations and noncommutative quasi-exactly solvable systems

    International Nuclear Information System (INIS)

    Klishevich, Sergey M; Plyushchay, Mikhail S

    2003-01-01

    We investigate a U(1) gauge invariant quantum mechanical system on a 2D noncommutative space with coordinates generating a generalized deformed oscillator algebra. The Hamiltonian is taken as a quadratic form in gauge covariant derivatives obeying the nonlinear Dolan-Grady relations. This restricts the structure function of the deformed oscillator algebra to a quadratic polynomial. The cases when the coordinates form the su(2) and sl(2,R) algebras are investigated in detail. Reducing the Hamiltonian to 1D finite-difference quasi-exactly solvable operators, we demonstrate partial algebraization of the spectrum of the corresponding systems on the fuzzy sphere and noncommutative hyperbolic plane. A completely covariant method based on the notion of intrinsic algebra is proposed to deal with the spectral problem of such systems

  11. Cijepani litički materijal s prapovijesnog nalazišta Slavča, Nova Gradiška

    OpenAIRE

    Šošić, Rajna; Karavanić, Ivor

    2005-01-01

    SUMMARY TECHNOLOGICAL AND TYPOLOGICAL ANALYSIS OF THE CHIPPED STONE ARTIFACTS FROM THE PREHISTORIC SITE OF SLAV^A, NOVA GRADI[KA The site of Slav~a is situated on the south flanks of Psunj Mountain, in the town of Nova Gradi{ ka, Western Slavonia. The site has been continuosly excavated since 1997 by the City Museum of Nova Gradi{ka. A total number of 1655 chipped stone artifacts have been analyised, classified to the Sopot, Kostolac and Lasinja cultures, in effect a peri...

  12. Strain-energy effects on dynamic fragmentation

    International Nuclear Information System (INIS)

    Glenn, L.A.; Chudnovsky, A.

    1986-01-01

    Grady's model of the dynamic fragmentation process, in which the average fragment size is determined by balancing the local kinetic energy and the surface energy, is modified to include the stored elastic (strain) energy. The revised model predicts that the strain energy should dominate for brittle materials, with low fracture toughness and high fracture-initiation stress. This conclusion is not borne out, however, by limited experimental data on brittle steels, even when the kinetic-energy density is small compared with the strain-energy density

  13. Marcella O'Grady Boveri (1863-1950): her three careers in biology.

    Science.gov (United States)

    Wright, M R

    1997-12-01

    The career of Marcella O'Grady Boveri (1863-1950), a nineteenth-century Catholic woman educated in biology at MIT and Bryn Mawr, is discussed both in the biological context of the times and with regard to the position of women in science. The thesis is that her life pattern differed strikingly from that of other woman biologists of her generation and that the character of her contributions to biology varied with that pattern. Perhaps it is in consequence that the significance of her considerable achievement has been hidden. Boveri's circumstances led her to collaboration rather than independence in research: she worked with skill and interest, but without formal recognition, on her husband's theoretically important and already established research program in Germany (1900-1915). She thought it a privilege to do so. Earlier (1889-1896), at Vassar College, and later (1927-1943), at the newly established Albertus Magnus College, she was an innovator who introduced and developed new curricula in biology, a stimulating and influential teacher, a mentor, and a role model. In addition, she did much to promote international communication, as exemplified both by her English translation of Theodor Boveri's prescient theory of cancer and by her influence in bringing important scientists to the United States.

  14. Failure by Fragmentation.

    Science.gov (United States)

    Gardner, Sid

    1990-01-01

    Because of a lack of program coordination and community accountability, services to children and youth are failing to address the problems of young people at risk. Collaboration among agencies can help social services to bypass program mentality. Communitywide interagency cooperation will include local scorecards, program linkages, and strategic…

  15. Marcella O'Grady Boveri (1865-1950) and the chromosome theory of cancer.

    Science.gov (United States)

    McKusick, V A

    1985-12-01

    Born into a Boston Irish family, Marcella Imelda O'Grady was the first woman graduate in biology from MIT (1885) where she came under the influence of two recent PhD graduates of Johns Hopkins University, William Townsend Sedgwick and Edmund Beecher Wilson. She taught science at Bryn Mawr School for girls in Baltimore 1885 to 1887 and was teaching assistant with E B Wilson at Bryn Mawr College for women in Bryn Mawr, Pennsylvania, 1887 to 1889. From 1889 to 1896 she headed the Department of Biology at Vassar College for women in Poughkeepsie, New York. On the recommendation of E B Wilson (who from the first edition in 1896 dedicated his famous book The cell in development and inheritance to Boveri) Marcella went to Würzburg to spend a sabbatical with Boveri. One year later she married Boveri and during the next 18 years until Boveri's untimely death in 1915 she was her husband's close scientific collaborator, especially in his work at the marine zoological stations in Naples and Villefranche, France. She also acquired (from Freiburg) the doctorate she had unsuccessfully attempted to get at Johns Hopkins. Marcella returned to the United States in 1926 and headed the Biology Department at Albertus Magnus College in New Haven. She was there in 1929 when her English translation of her husband's 1914 monograph advancing the chromosome theory of cancer was published. The translation did much to bring that theory to the attention of a wider audience which has thereby been able to rediscover Boveri, despite lack of a reading knowledge of German. Boveri's theory was based on the views that cancer is a cellular problem, cancers originate from a single cell, this cell has an abnormality of its chromosomal constitution, and the chromosomal abnormality which is passed on to all the descendants of the cell of origin is the cause of rapid cell proliferation.

  16. Treatment of sleep apnea in chronic heart failure patients with auto-servo ventilation improves sleep fragmentation: a randomized controlled trial.

    Science.gov (United States)

    Hetzenecker, Andrea; Escourrou, Pierre; Kuna, Samuel T; Series, Frederic; Lewis, Keir; Birner, Christoph; Pfeifer, Michael; Arzt, Michael

    2016-01-01

    Impaired sleep efficiency is independently associated with worse prognosis in patients with chronic heart failure (CHF). Therefore, a test was conducted on whether auto-servo ventilation (ASV, biphasic positive airway pressure [BiPAP]-ASV, Philips Respironics) reduces sleep fragmentation and improves sleep efficiency in CHF patients with central sleep apnea (CSA) or obstructive sleep apnea (OSA). In this multicenter, randomized, parallel group trial, a study was conducted on 63 CHF patients (age 64 ± 10 years; left ventricular ejection fraction 29 ± 7%) with CSA or OSA (apnea-hypopnea Index, AHI 47 ± 18/h; 46% CSA) referred to sleep laboratories of the four participating centers. Participants were randomized to either ASV (n = 32) or optimal medical treatment alone (control, n = 31). Polysomnography (PSG) and actigraphy at home (home) with centralized blinded scoring were obtained at baseline and 12 weeks. ASV significantly reduced sleep fragmentation (total arousal indexPSG: -16.4 ± 20.6 vs. -0.6 ± 13.2/h, p = 0.001; sleep fragmentation indexhome: -7.6 ± 15.6 versus 4.3 ± 13.9/h, p = 0.003, respectively) and significantly increased sleep efficiency assessed by actigraphy (SEhome) compared to controls (2.3 ± 10.1 vs. -2.1 ± 6.9%, p = 0.002). Effects of ASV on sleep fragmentation and efficiency were similar in patients suffering from OSA and CSA. At home, ASV treatment modestly improves sleep fragmentation as well as sleep efficiency in CHF patients having either CSA or OSA. Copyright © 2015 Elsevier B.V. All rights reserved.

  17. Effect of using ultrapure dialysate for hemodialysis on the level of circulating bacterial fragment in renal failure patients.

    Science.gov (United States)

    Kwan, Bonnie Ching-Ha; Chow, Kai-Ming; Ma, Terry King-Wing; Cheng, Phyllis Mei-Shan; Leung, Chi-Bon; Li, Philip Kam-Tao; Szeto, Cheuk-Chun

    2013-01-01

    Cardiovascular disease is the major cause of mortality and morbidity in dialysis patients. Recently, circulating endotoxin is found to associate with the systemic inflammatory state and cardiovascular disease of dialysis patients. Previous studies showed that the use of ultrapure dialysate for hemodialysis could reduce the exposure to exogenous endotoxin. We studied the effect of using ultrapure dialysate for hemodialysis on circulating endotoxin and bacterial DNA fragment levels and vascular stiffness. This is an open-labeled prospective study of 25 patients (14 male). Circulating endotoxin and bacterial DNA level, vascular stiffness as represented by arterial pulse wave velocity (PWV), nutrition and hydration status were monitored before and repeatedly throughout 12 months after the use of ultrapure dialysate for hemodialysis. The average age was 58.9 ± 10.2 years; 21 patients completed the study. Within 4 weeks of conversion to ultrapure dialysate for hemodialysis, the plasma endotoxin level fell from 0.302 ± 0.083 to 0.209 ± 0.044 EU/ml (p hemodialysis patients, circulating endotoxin level is associated with vascular stiffness and systemic inflammation. Using ultrapure dialysate for hemodialysis effectively reduces circulating endotoxin level in hemodialysis patients. The long-term benefit of using ultrapure dialysate for hemodialysis requires further study. © 2013 S. Karger AG, Basel.

  18. Integrating research and practice for optimal clinical outcomes: an interview with Tim Porter-O'Grady. Interview by Gail S Wick.

    Science.gov (United States)

    Porter-O'Grady, T

    1996-06-01

    Dr. Porter-O'Grady has written over 125 articles and book chapters and has published eight books and is completing a ninth. He has consulted with over 500 institutions and has spoken in 1300 settings in the U.S., Canada, Europe, and Asia and logs about 350,000 miles a year. Dr. Porter-O'Grady is listed in six different categories of Who's Who in America, serves on 7 editorial boards, and is a member of the New York Academy of Sciences and a Fellow in the American Academy of Nursing. He has served on a number of community boards and has been an elected officer in a variety of health related agencies and organizations. He is currently a health systems expert for the National Health Policy Council and is a member of the Georgia Health Care Reform Project. In this interview, which took place in Atlanta by ANNA Past President Gail Wick, Dr. Porter-O'Grady shares his wealth of knowledge and experience by challenging us to move beyond the old thinking of caring for a specific patient population to managing lives on a continuum of care in an interdependent relationship with other providers, to refine the term "patient care," letting go of the medical sickness model and returning to our life-centered, health-oriented nursing roots and to broaden our educational preparation to a systems perspective and a continuum of caring.

  19. Society News: Monica Grady awarded CBE; Grubb Parsons Lecture 2012; Join the RAS; Astronomy on radio for kids; New Fellows; Peter D Hingley

    Science.gov (United States)

    2012-08-01

    RAS Fellow Prof. Monica Grady has been made a Commander of the Most Excellent Order of the British Empire (CBE), in recognition of her services to space science. The RAS sponsors the annual Grubb Parsons Lecture, which this year took place on 6 June at the University of Durham. If you are a professional astronomer, geophysicist, or similar, a student studying these disciplines, or simply someone with a serious interest in them, we urge you to apply for membership of the RAS. Outreach is an important activity for the RAS. We recently supported an astronomy series called Deep Space High on the digital radio channel Fun Kids.

  20. Simulation of natural fragmentation of rings cut from warheads

    Directory of Open Access Journals (Sweden)

    John F. Moxnes

    2015-12-01

    Full Text Available Natural fragmentation of warheads that detonates causes the casing of the warhead to split into various sized fragments through shear or radial fractures depending on the toughness, density, and grain size of the material. The best known formula for the prediction of the size distribution is the Mott formulae, which is further examined by Grady and Kipp by investigating more carefully the statistical most random way of portioning a given area into a number of entities. We examine the fragmentation behavior of radially expanding steel rings cut from a 25 mm warhead by using an in house smooth particle hydrodynamic (SPH simulation code called REGULUS. Experimental results were compared with numerical results applying varying particle size and stochastic fracture strain. The numerically obtained number of fragments was consistent with experimental results. Increasing expansion velocity of the rings increases the number of fragments. Statistical variation of the material parameters influences the fragment characteristics, especially for low expansion velocities. A least square regression fit to the cumulative number of fragments by applying a generalized Mott distribution shows that the shape parameter is around 4 for the rings, which is in contrast to the Mott distribution with a shape parameter of ½. For initially polar distributed particles, we see signs of a bimodal cumulative fragment distribution. Adding statistical variation in material parameters of the fracture model causes the velocity numerical solutions to become less sensitive to changes in resolution for Cartesian distributed particles.

  1. Jet fragmentation

    International Nuclear Information System (INIS)

    Saxon, D.H.

    1985-10-01

    The paper reviews studies on jet fragmentation. The subject is discussed under the topic headings: fragmentation models, charged particle multiplicity, bose-einstein correlations, identified hadrons in jets, heavy quark fragmentation, baryon production, gluon and quark jets compared, the string effect, and two successful models. (U.K.)

  2. Nuclear fragmentation

    International Nuclear Information System (INIS)

    Chung, K.C.

    1989-01-01

    An introduction to nuclear fragmentation, with emphasis in percolation ideas, is presented. The main theoretical models are discussed and as an application, the uniform expansion approximation is presented and the statistical multifragmentation model is used to calculate the fragment energy spectra. (L.C.)

  3. Controlled fragmentation

    International Nuclear Information System (INIS)

    Arnold, Werner

    2002-01-01

    Contrary to natural fragmentation, controlled fragmentation offers the possibility to adapt fragment parameters like size and mass to the performance requirements in a very flexible way. Known mechanisms like grooves inside the casing, weaken the structure. This is, however, excluded for applications with high accelerations during launch or piercing requirements for example on a semi armor piercing penetrator. Another method to achieve controlled fragmentation with an additional grid layer is presented with which the required grooves are produced 'just in time' inside the casing during detonation of the high explosive. The process of generating the grooves aided by the grid layer was studied using the hydrocode HULL with respect to varying grid designs and material combinations. Subsequent to this, a large range of these theoretically investigated combinations was contemplated in substantial experimental tests. With an optimised grid design and a suitable material selection, the controlled fragment admits a very flexible adaptation to the set requirements. Additional advantages like the increase of perforation performance or incendiary amplification can be realized with the grid layer

  4. Chameleon fragmentation

    Energy Technology Data Exchange (ETDEWEB)

    Brax, Philippe [Institut de Physique Théorique, CEA, IPhT, CNRS, URA 2306, F-91191Gif/Yvette Cedex (France); Upadhye, Amol, E-mail: philippe.brax@cea.fr, E-mail: aupadhye@anl.gov [Institute for the Early Universe, Ewha University, International Education, Building #601, 11-1, Daehyun-Dong Seodaemun-Gu, Seoul 120-750 (Korea, Republic of)

    2014-02-01

    A scalar field dark energy candidate could couple to ordinary matter and photons, enabling its detection in laboratory experiments. Here we study the quantum properties of the chameleon field, one such dark energy candidate, in an ''afterglow'' experiment designed to produce, trap, and detect chameleon particles. In particular, we investigate the possible fragmentation of a beam of chameleon particles into multiple particle states due to the highly non-linear interaction terms in the chameleon Lagrangian. Fragmentation could weaken the constraints of an afterglow experiment by reducing the energy of the regenerated photons, but this energy reduction also provides a unique signature which could be detected by a properly-designed experiment. We show that constraints from the CHASE experiment are essentially unaffected by fragmentation for φ{sup 4} and 1/φ potentials, but are weakened for steeper potentials, and we discuss possible future afterglow experiments.

  5. Chameleon fragmentation

    International Nuclear Information System (INIS)

    Brax, Philippe; Upadhye, Amol

    2014-01-01

    A scalar field dark energy candidate could couple to ordinary matter and photons, enabling its detection in laboratory experiments. Here we study the quantum properties of the chameleon field, one such dark energy candidate, in an ''afterglow'' experiment designed to produce, trap, and detect chameleon particles. In particular, we investigate the possible fragmentation of a beam of chameleon particles into multiple particle states due to the highly non-linear interaction terms in the chameleon Lagrangian. Fragmentation could weaken the constraints of an afterglow experiment by reducing the energy of the regenerated photons, but this energy reduction also provides a unique signature which could be detected by a properly-designed experiment. We show that constraints from the CHASE experiment are essentially unaffected by fragmentation for φ 4 and 1/φ potentials, but are weakened for steeper potentials, and we discuss possible future afterglow experiments

  6. Bespoke Fragments

    DEFF Research Database (Denmark)

    Kruse Aagaard, Anders

    2017-01-01

    The PhD project Bespoke Fragments is investigating the space emerging in the exploration of the relationship between digital drawing and fabrication, and the field of materials and their properties and capacities. Through a series of different experiments, the project situates itself in a shuttli...

  7. Rock fragmentation

    Energy Technology Data Exchange (ETDEWEB)

    Brown, W.S.; Green, S.J.; Hakala, W.W.; Hustrulid, W.A.; Maurer, W.C. (eds.)

    1976-01-01

    Experts in rock mechanics, mining, excavation, drilling, tunneling and use of underground space met to discuss the relative merits of a wide variety of rock fragmentation schemes. Information is presented on novel rock fracturing techniques; tunneling using electron beams, thermocorer, electric spark drills, water jets, and diamond drills; and rock fracturing research needs for mining and underground construction. (LCL)

  8. Architectural fragments

    DEFF Research Database (Denmark)

    Bang, Jacob Sebastian

    2018-01-01

    I have created a large collection of plaster models: a collection of Obstructions, errors and opportunities that may develop into architecture. The models are fragments of different complex shapes as well as more simple circular models with different profiling and diameters. In this contect I have....... I try to invent the ways of drawing the models - that decode and unfold them into architectural fragments- into future buildings or constructions in the landscape. [1] Luigi Moretti: Italian architect, 1907 - 1973 [2] Man Ray: American artist, 1890 - 1976. in 2015, I saw the wonderful exhibition...... "Man Ray - Human Equations" at the Glyptotek in Copenhagen, organized by the Philips Collection in Washington D.C. and the Israel Museum in Jerusalem (in 2013). See also: "Man Ray - Human Equations" catalogue published by Hatje Cantz Verlag, Germany, 2014....

  9. Intermediate Fragment

    DEFF Research Database (Denmark)

    Kruse Aagaard, Anders

    2015-01-01

    This text and its connected exhibition are aiming to reflect both on the thoughts, the processes and the outcome of the design and production of the artefact ‘Intermediate Fragment’ and making as a contemporary architectural tool in general. Intermediate Fragment was made for the exhibition ‘Enga...... of realising an exhibition object was conceived, but expanded, refined and concretised through this process. The context of the work shown here is an interest in a tighter, deeper connection between experimentally obtained material knowledge and architectural design....

  10. Fragmentation based

    Directory of Open Access Journals (Sweden)

    Shashank Srivastava

    2014-01-01

    Gaining the understanding of mobile agent architecture and the security concerns, in this paper, we proposed a security protocol which addresses security with mitigated computational cost. The protocol is a combination of self decryption, co-operation and obfuscation technique. To circumvent the risk of malicious code execution in attacking environment, we have proposed fragmentation based encryption technique. Our encryption technique suits the general mobile agent size and provides hard and thorny obfuscation increasing attacker’s challenge on the same plane providing better performance with respect to computational cost as compared to existing AES encryption.

  11. Bespoke Fragments

    DEFF Research Database (Denmark)

    Kruse Aagaard, Anders

    2016-01-01

    , investigating levels of control and uncertainty encountering with these. Through tangible experiments, the project discusses materiality and digitally controlled fabrications tools as direct expansions of the architect's digital drawing and workflow. The project sees this expansion as an opportunity to connect...... architectural designs, tectonics and aesthetics. In this Ph.D.-project a series a physical, but conceptual, experiment plays the central role in the knowledge production. The experiments result in materialised architectural fragments and tangible experiences. However, these creations also become the driving...

  12. Improved Barriers to Turbine Engine Fragments: Interim Report II

    National Research Council Canada - National Science Library

    Shockey, Donald

    1999-01-01

    Because fragments from in-flight engine failures can damage critical aircraft components and produce catastrophic consequences, the Federal Aviation Administration is sponsoring research to mitigate...

  13. Framing Fragmentation

    DEFF Research Database (Denmark)

    Bundgaard, Charlotte

    2009-01-01

    Contemporary industrialized architecture based on advanced information technology and highly technological production processes, implies a radically different approach to architecture than what we have experienced in the past. Works of architecture composed of prefabricated building components......, contain distinctive architectural traits, not only based on rational repetition, but also supporting composition and montage as dynamic concepts. Prefab architecture is an architecture of fragmentation, individualization and changeability, and this sets up new challenges for the architect. This paper...... tries to develop a strategy for the architect dealing with industrially based architecture; a strategy which exploits architectural potentials in industrial building, which recognizes the rules of mass production and which redefines the architect’s position among the agents of building. If recent...

  14. OLD SCHOOL LINGUISTICS MADE NEW— REVIEW OF Contemporary Linguistics: An Introduction. 5th ed. By William O’Grady, John Archibald, Mark Arnoff, and Janie Rees-Miller. New York: Bedford/St. Martin’s, 2005. Pp. xxvi + 684.

    Directory of Open Access Journals (Sweden)

    Chris Wen-chao Li

    2008-06-01

    Full Text Available Amidst the recent explosion of interest in linguistic science and the subsequent publication of large numbers of introductory works on the subject, O'Grady et al.'s Contemporary Linguistics (5th ed. stands out as a solid general purpose primer directed at an academic audience. Written by some eighteen contributors specializing in each of the seventeen branches of linguistics covered, topics are judiciously chosen while drawing on current scholarship and integrating different theoretical persuasions, without losing sight of the book's target readership. The result is an up-to-date text balanced in its treatment of subject matter and perspectives--a work that lives up to its moniker of "Contemporary" Linguistics.

  15. Current fragmentation in deep inelastic scattering

    International Nuclear Information System (INIS)

    Hamer, C.J.

    1975-04-01

    It is argued that the current fragmentation products in deep inelastic electron scattering will not be distributed in a 'one-dimensional' rapidity plateau as in the parton model picture of Feynman and Bjorken. A reaction mechanism with a multiperipheral topology, but which the above configuration might have been achieved, does not in fact populate the current fragmentation plateau; and unless partons are actually observed in the final state, it cannot lead to Bjorken scaling. The basic reason for this failure is shown to be the fact that when a particle is produced in the current fragmentation plateau, the adjacent momentum transfer in the multiperipheral chain becomes large and negative: such processes are inevitably suppressed. Instead, the current fragmentation products are likely to be generated by a fragmentation, or sequential decay process. (author)

  16. Universal elements of fragmentation

    International Nuclear Information System (INIS)

    Yanovsky, V. V.; Tur, A. V.; Kuklina, O. V.

    2010-01-01

    A fragmentation theory is proposed that explains the universal asymptotic behavior of the fragment-size distribution in the large-size range, based on simple physical principles. The basic principles of the theory are the total mass conservation in a fragmentation process and a balance condition for the energy expended in increasing the surface of fragments during their breakup. A flux-based approach is used that makes it possible to supplement the basic principles and develop a minimal theory of fragmentation. Such a supplementary principle is that of decreasing fragment-volume flux with increasing energy expended in fragmentation. It is shown that the behavior of the decreasing flux is directly related to the form of a power-law fragment-size distribution. The minimal theory is used to find universal asymptotic fragment-size distributions and to develop a natural physical classification of fragmentation models. A more general, nonlinear theory of strong fragmentation is also developed. It is demonstrated that solutions to a nonlinear kinetic equation consistent with both basic principles approach a universal asymptotic size distribution. Agreement between the predicted asymptotic fragment-size distributions and experimental observations is discussed.

  17. Improved Barriers to Turbine Engine Fragments: Final Annual Report

    National Research Council Canada - National Science Library

    Shockey, Donald

    2002-01-01

    .... Previous large-scale fragment impact testing of comer peg-mounted fabric barriers indicated that the failure of the fabric around the pegged hole was a significant factor in the barrier's effectiveness...

  18. Full-Scale Tests of Lightweight Fragment Barriers on Commercial Aircraft

    National Research Council Canada - National Science Library

    Shockey, Donald

    1999-01-01

    Because fragments from inflight engine failures can damage critical aircraft components and produce catastrophic consequences, the Federal Aviation Administration is sponsoring research to mitigate...

  19. Universality of fragment shapes.

    Science.gov (United States)

    Domokos, Gábor; Kun, Ferenc; Sipos, András Árpád; Szabó, Tímea

    2015-03-16

    The shape of fragments generated by the breakup of solids is central to a wide variety of problems ranging from the geomorphic evolution of boulders to the accumulation of space debris orbiting Earth. Although the statistics of the mass of fragments has been found to show a universal scaling behavior, the comprehensive characterization of fragment shapes still remained a fundamental challenge. We performed a thorough experimental study of the problem fragmenting various types of materials by slowly proceeding weathering and by rapid breakup due to explosion and hammering. We demonstrate that the shape of fragments obeys an astonishing universality having the same generic evolution with the fragment size irrespective of materials details and loading conditions. There exists a cutoff size below which fragments have an isotropic shape, however, as the size increases an exponential convergence is obtained to a unique elongated form. We show that a discrete stochastic model of fragmentation reproduces both the size and shape of fragments tuning only a single parameter which strengthens the general validity of the scaling laws. The dependence of the probability of the crack plan orientation on the linear extension of fragments proved to be essential for the shape selection mechanism.

  20. Anomalous nuclear fragments

    International Nuclear Information System (INIS)

    Karmanov, V.A.

    1983-01-01

    Experimental data are given, the status of anomalon problem is discussed, theoretical approaches to this problem are outlined. Anomalons are exotic objects formed following fragmentation of nuclei-targets under the effect of nuclei - a beam at the energy of several GeV/nucleon. These nuclear fragments have an anomalously large cross section of interaction and respectively, small free path, considerably shorter than primary nuclei have. The experimental daa are obtained in accelerators following irradiation of nuclear emulsions by 16 O, 56 Fe, 40 Ar beams, as well as propane by 12 C beams. The experimental data testify to dependence of fragment free path on the distance L from the point of the fragment formation. A decrease in the fragment free path is established more reliably than its dependence on L. The problem of the anomalon existence cannot be yet considered resolved. Theoretical models suggested for explanation of anomalously large cross sections of nuclear fragment interaction are variable and rather speculative

  1. Fission fragment angular momentum

    International Nuclear Information System (INIS)

    Frenne, D. De

    1991-01-01

    Most of the energy released in fission is converted into translational kinetic energy of the fragments. The remaining excitation energy will be distributed among neutrons and gammas. An important parameter characterizing the scission configuration is the primary angular momentum of the nascent fragments. Neutron emission is not expected to decrease the spin of the fragments by more than one unit of angular momentum and is as such of less importance in the determination of the initial fragment spins. Gamma emission is a suitable tool in studying initial fragment spins because the emission time, number, energy, and multipolarity of the gammas strongly depend on the value of the primary angular momentum. The main conclusions of experiments on gamma emission were that the initial angular momentum of the fragments is large compared to the ground state spin and oriented perpendicular to the fission axis. Most of the recent information concerning initial fragment spin distributions comes from the measurement of isomeric ratios for isomeric pairs produced in fission. Although in nearly every mass chain isomers are known, only a small number are suitable for initial fission fragment spin studies. Yield and half-life considerations strongly limit the number of candidates. This has the advantage that the behavior of a specific isomeric pair can be investigated for a number of fissioning systems at different excitation energies of the fragments and fissioning nuclei. Because most of the recent information on primary angular momenta comes from measurements of isomeric ratios, the global deexcitation process of the fragments and the calculation of the initial fragment spin distribution from measured isomeric ratios are discussed here. The most important results on primary angular momentum determinations are reviewed and some theoretical approaches are given. 45 refs., 7 figs., 2 tabs

  2. String fragmentation; La fragmentation des cordes

    Energy Technology Data Exchange (ETDEWEB)

    Drescher, H.J.; Werner, K. [Laboratoire de Physique Subatomique et des Technologies Associees - SUBATECH, Centre National de la Recherche Scientifique, 44 - Nantes (France)

    1997-10-01

    The classical string model is used in VENUS as a fragmentation model. For the soft domain simple 2-parton strings were sufficient, whereas for higher energies up to LHC, the perturbative regime of the QCD gives additional soft gluons, which are mapped on the string as so called kinks, energy singularities between the leading partons. The kinky string model is chosen to handle fragmentation of these strings by application of the Lorentz invariant area law. The `kinky strings` model, corresponding to the perturbative gluons coming from pQCD, takes into consideration this effect by treating the partons and gluons on the same footing. The decay law is always the Artru-Menessier area law which is the most realistic since it is invariant to the Lorentz and gauge transformations. For low mass strings a manipulation of the rupture point is necessary if the string corresponds already to an elementary particle determined by the mass and the flavor content. By means of the fragmentation model it will be possible to simulate the data from future experiments at LHC and RHIC 3 refs.

  3. Tests of landscape influence: nest predation and brood parasitism in fragmented ecosystems

    Science.gov (United States)

    Joshua J. Tewksbury; Lindy Garner; Shannon H. Garner; John D. Lloyd; Victoria A. Saab; Thomas E. Martin

    2006-01-01

    The effects of landscape fragmentation on nest predation and brood parasitism, the two primary causes of avian reproductive failure, have been difficult to generalize across landscapes, yet few studies have clearly considered the context and spatial scale of fragmentation. Working in two river systems fragmented by agricultural and rural-housing development, we tracked...

  4. Dimensional crossover in fragmentation

    Science.gov (United States)

    Sotolongo-Costa, Oscar; Rodriguez, Arezky H.; Rodgers, G. J.

    2000-11-01

    Experiments in which thick clay plates and glass rods are fractured have revealed different behavior of fragment mass distribution function in the small and large fragment regions. In this paper we explain this behavior using non-extensive Tsallis statistics and show how the crossover between the two regions is caused by the change in the fragments’ dimensionality during the fracture process. We obtain a physical criterion for the position of this crossover and an expression for the change in the power-law exponent between the small and large fragment regions. These predictions are in good agreement with the experiments on thick clay plates.

  5. Embedded Fragments Registry (EFR)

    Data.gov (United States)

    Department of Veterans Affairs — In 2009, the Department of Defense estimated that approximately 40,000 service members who served in OEF/OIF may have embedded fragment wounds as the result of small...

  6. Physics of projectile fragments

    International Nuclear Information System (INIS)

    Minamisono, Tadanori

    1982-01-01

    This is a study report on the polarization phenomena of the projectile fragments produced by heavy ion reactions, and the beta decay of fragments. The experimental project by using heavy ions with the energy from 50 MeV/amu to 250 MeV/amu was designed. Construction of an angle-dispersion spectrograph for projectile fragments was proposed. This is a two-stage spectrograph. The first stage is a QQDQQ type separator, and the second stage is QDQD type. Estimation shows that Co-66 may be separated from the nuclei with mass of 65 and 67. The orientation of fragments can be measured by detecting beta-ray. The apparatus consists of a uniform field magnet, an energy absorber, a stopper, a RF coil and a beta-ray hodoscope. This system can be used for not only this purpose but also for the measurement of hyperfine structure. (Kato, T.)

  7. Fragmentation Main Model

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — The fragmentation model combines patch size and patch continuity with diversity of vegetation types per patch and rarity of vegetation types per patch. A patch was...

  8. Stone fragmentation by ultrasound

    Indian Academy of Sciences (India)

    Unknown

    In the present work, enhancement of the kidney stone fragmentation by using ultrasound is studied. The cavi- ... ment system like radiation pressure balance, the power is given by ... Thus the bubble size has direct relationship with its life and.

  9. Fragment capture device

    Science.gov (United States)

    Payne, Lloyd R.; Cole, David L.

    2010-03-30

    A fragment capture device for use in explosive containment. The device comprises an assembly of at least two rows of bars positioned to eliminate line-of-sight trajectories between the generation point of fragments and a surrounding containment vessel or asset. The device comprises an array of at least two rows of bars, wherein each row is staggered with respect to the adjacent row, and wherein a lateral dimension of each bar and a relative position of each bar in combination provides blockage of a straight-line passage of a solid fragment through the adjacent rows of bars, wherein a generation point of the solid fragment is located within a cavity at least partially enclosed by the array of bars.

  10. DNA fragmentation in spermatozoa

    DEFF Research Database (Denmark)

    Rex, A S; Aagaard, J.; Fedder, J

    2017-01-01

    Sperm DNA Fragmentation has been extensively studied for more than a decade. In the 1940s the uniqueness of the spermatozoa protein complex which stabilizes the DNA was discovered. In the fifties and sixties, the association between unstable chromatin structure and subfertility was investigated....... In the seventies, the impact of induced DNA damage was investigated. In the 1980s the concept of sperm DNA fragmentation as related to infertility was introduced as well as the first DNA fragmentation test: the Sperm Chromatin Structure Assay (SCSA). The terminal deoxynucleotidyl transferase nick end labelling...... (TUNEL) test followed by others was introduced in the nineties. The association between DNA fragmentation in spermatozoa and pregnancy loss has been extensively investigated spurring the need for a therapeutic tool for these patients. This gave rise to an increased interest in the aetiology of DNA damage...

  11. Fragment Impact Toolkit (FIT)

    Energy Technology Data Exchange (ETDEWEB)

    Shevitz, Daniel Wolf [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Key, Brian P. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Garcia, Daniel B. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-09-05

    The Fragment Impact Toolkit (FIT) is a software package used for probabilistic consequence evaluation of fragmenting sources. The typical use case for FIT is to simulate an exploding shell and evaluate the consequence on nearby objects. FIT is written in the programming language Python and is designed as a collection of interacting software modules. Each module has a function that interacts with the other modules to produce desired results.

  12. Respiratory Failure

    Science.gov (United States)

    Respiratory failure happens when not enough oxygen passes from your lungs into your blood. Your body's organs, ... brain, need oxygen-rich blood to work well. Respiratory failure also can happen if your lungs can' ...

  13. Fragmentation of relativistic nuclei

    International Nuclear Information System (INIS)

    Cork, B.

    1975-06-01

    Nuclei with energies of several GeV/n interact with hadrons and produce fragments that encompass the fields of nuclear physics, meson physics, and particle physics. Experimental results are now available to explore problems in nuclear physics such as the validity of the shell model to explain the momentum distribution of fragments, the contribution of giant dipole resonances to fragment production cross sections, the effective Coulomb barrier, and nuclear temperatures. A new approach to meson physics is possible by exploring the nucleon charge-exchange process. Particle physics problems are explored by measuring the energy and target dependence of isotope production cross sections, thus determining if limiting fragmentation and target factorization are valid, and measuring total cross sections to determine if the factorization relation, sigma/sub AB/ 2 = sigma/sub AA/ . sigma/sub BB/, is violated. Also, new experiments have been done to measure the angular distribution of fragments that could be explained as nuclear shock waves, and to explore for ultradense matter produced by very heavy ions incident on heavy atoms. (12 figures, 2 tables)

  14. Heart Failure

    Science.gov (United States)

    Heart failure is a condition in which the heart can't pump enough blood to meet the body's needs. Heart failure does not mean that your heart has stopped ... and shortness of breath Common causes of heart failure are coronary artery disease, high blood pressure and ...

  15. Land fragmentation and production diversification

    NARCIS (Netherlands)

    Ciaian, Pavel; Guri, Fatmir; Rajcaniova, Miroslava; Drabik, Dusan; Paloma, Sergio Gomez Y.

    2018-01-01

    We analyze the impact of land fragmentation on production diversification in rural Albania. Albania represents a particularly interesting case for studying land fragmentation as the fragmentation is a direct outcome of land reforms. The results indicate that land fragmentation is an important driver

  16. Heavy fragment radioactivity

    International Nuclear Information System (INIS)

    Silisteanu, I.

    1991-06-01

    The effect of collective mode excitation in heavy fragment radioactivity (HFR) is explored and discussed in the light of current experimental data. It is found that the coupling and resonance effects in fragment interaction and also the proper angular momentum effects may lead to an important enhancing of the emission process. New useful procedures are proposed for the study of nuclear decay properties. The relations between different decay processes are investigated in detail. We are also trying to understand and explain in a unified way the reaction mechanisms in decay phenomena. (author). 17 refs, 4 figs, 3 tabs

  17. Learning from Failures in Operations

    DEFF Research Database (Denmark)

    Koch, Christian

    2005-01-01

    parallelism and fragmentation due to their predominantly quantitative complexity. It is suggested that a number of critical junctions occur in these processes and that obtaining quality and avoiding failures quite often requires a series of competent and situational operation management actions. An empirical...... product. The analysis showed that, among others, design review, project review, commencing and finalizing operations turned out to be critical junctions in the control of failures. Practical implications and improvements are discussed. The focus on critical junctions, points to supply chain management......This paper discusses failures and quality in operations in design and production of buildings. The importance of human action, interpretations and interactions in tackling complexity, fragmentation and disturbances in the building industry is underlined. Building processes encompass requisite...

  18. PELE fragmentation dynamics

    NARCIS (Netherlands)

    Verreault, J.; Hinsberg, N.P. van; Abadjieva, E.

    2013-01-01

    An analytical model that describes the PELE fragmentation dynamics is presented and compared with experimental results from literature. The model accounts for strong shock effects and detailed interactions taking place between the filling – the inner core of the ammunition – and the target

  19. Cryobiology of coral fragments.

    Science.gov (United States)

    Hagedorn, Mary; Farrell, Ann; Carter, Virginia L

    2013-02-01

    Around the world, coral reefs are dying due to human influences, and saving habitat alone may not stop this destruction. This investigation focused on the biological processes that will provide the first steps in understanding the cryobiology of whole coral fragments. Coral fragments are a partnership of coral tissue and endosymbiotic algae, Symbiodinium sp., commonly called zooxanthellae. These data reflected their separate sensitivities to chilling and a cryoprotectant (dimethyl sulfoxide) for the coral Pocillopora damicornis, as measured by tissue loss and Pulse Amplitude Modulated fluorometry 3weeks post-treatment. Five cryoprotectant treatments maintained the viability of the coral tissue and zooxanthellae at control values (1M dimethyl sulfoxide at 1.0, 1.5 and 2.0h exposures, and 1.5M dimethyl sulfoxide at 1.0 and 1.5h exposures, P>0.05, ANOVA), whereas 2M concentrations did not (Pzooxanthellae. During the winter when the fragments were chilled, the coral tissue remained relatively intact (∼25% loss) post-treatment, but the zooxanthellae numbers in the tissue declined after 5min of chilling (Pzooxanthellae numbers declined in response to chilling alone (P0.05, ANOVA), but it did not protect against the loss of zooxanthellae (Pzooxanthellae are the most sensitive element in the coral fragment complex and future cryopreservation protocols must be guided by their greater sensitivity. Copyright © 2012 Elsevier Inc. All rights reserved.

  20. Fragments of the Past

    OpenAIRE

    Peter Szende; Annie Holcombe

    2016-01-01

    With travel being made more accessible throughout the decades, the hospitality industry constantly evolved their practices as society and technology progressed. Hotels looked for news ways up service their customers, which led to the invention of the Servidor in 1918. Once revolutionary innovations have gone extinct, merely becoming fragments of the past.

  1. Synthesis of arabinoxylan fragments

    DEFF Research Database (Denmark)

    Underlin, Emilie Nørmølle; Böhm, Maximilian F.; Madsen, Robert

    , or production of commercial chemicals which are mainly obtained from fossil fuels today.The arbinoxylan fragments have a backbone of β-1,4-linked xylans with α-L-arabinose units attached at specific positions. The synthesis ultilises an efficient synthetic route, where all the xylan units can be derived from D...

  2. Fragmented Work Stories

    DEFF Research Database (Denmark)

    Humle, Didde Maria; Reff Pedersen, Anne

    2015-01-01

    stories. We argue that meaning by story making is not always created by coherence and causality; meaning is created by different types of fragmentation: discontinuities, tensions and editing. The objective of this article is to develop and advance antenarrative practice analysis of work stories...

  3. Fragments of the Past

    Directory of Open Access Journals (Sweden)

    Peter Szende

    2016-10-01

    Full Text Available With travel being made more accessible throughout the decades, the hospitality industry constantly evolved their practices as society and technology progressed. Hotels looked for news ways up service their customers, which led to the invention of the Servidor in 1918. Once revolutionary innovations have gone extinct, merely becoming fragments of the past.

  4. PELE弹丸靶后破片尺寸分布研究%A study on fragmentation distribution of PELE

    Institute of Scientific and Technical Information of China (English)

    樊自建; 冉宪文; 汤文辉; 黄秋生

    2017-01-01

    Target plate rear damage effect is closely related to the fragment's size and quantity which are produced by penetrator with enhanced lateral effect (PELE).In order to study the factors influencing the scale of projectile shell fragments and determine the fragment distribution scale,the expansion process of PELE projectile shell was analyzed,according to the Mott-Grady fragmentation theory.The theoretical analysis method of the distribution range of the fragment scale was given.The correctness of the theoretical analysis was tested by experiments.By theoretical analysis and experimental study,the results show that projectile shell fragment size distribution is mainly affected by material density,crushing energy consumption,critical fracture strain and strain rate.The fragments width and number are greatly influenced by inner core material.With the increasing of density and elastic modulus of the inner core material,the width of front-end fragment decreases the number,the radial velocity becomes large.The shell fragment length is determined by projectile impacting target speed and less affected by the inner core material.%横向效应增强型弹丸(PELE)靶后毁伤效果与穿靶后形成的破片数量及大小密切相关.依据Mott-Grady破碎理论和PELE弹丸壳体膨胀过程假设,提出了弹丸壳体破片尺寸分布范围的理论分析方法,并通过实验回收弹体破片尺寸的统计分析,验证了理论分析方法的合理性.理论与实验研究表明,PELE弹丸壳体破片尺寸分布与壳体材料密度、破碎耗能、临界破碎应变、应变率等因素相关;破片的环向宽度和数量受内芯材料的影响较大,存在随着内芯材料的密度和弹性模量的增加前端破片环向宽度减小,数量增多,径向飞散速度变大的规律;但从实验结果看,外壳破片轴向长度则受内芯材料的影响较小,主要与弹靶碰撞速度相关.

  5. Contraceptive failure

    DEFF Research Database (Denmark)

    Rasch, Vibeke

    2002-01-01

    Most studies focusing on contraceptive failure in relation to pregnancy have focused on contraceptive failure among women having induced abortions, thereby neglecting those women who, despite contraceptive failure, accept the pregnancy and intend to carry the fetus to term. To get a more complete...... picture of the problem of contraceptive failure, this study focuses on contraceptive failure among women with diverse pregnancy outcomes. In all, 3520 pregnant women attending Odense University Hospital were included: 373 had induced abortions, 435 had spontaneous abortions, 97 had ectopic pregnancies......, and 2614 received antenatal care. The variables studied comprise age, partner relationship, number of births, occupational and economical situation, and contraceptive use.Contraceptive failure, defined as contraceptive use (condom, diaphragm, IUD, oral contraception, or another modern method...

  6. Heart Failure

    OpenAIRE

    McMurray, John; Ponikowski, Piotr

    2011-01-01

    Heart failure occurs in 3% to 4% of adults aged over 65 years, usually as a consequence of coronary artery disease or hypertension, and causes breathlessness, effort intolerance, fluid retention, and increased mortality. The 5-year mortality in people with systolic heart failure ranges from 25% to 75%, often owing to sudden death following ventricular arrhythmia. Risks of cardiovascular events are increased in people with left ventricular systolic dysfunction (LVSD) or heart failure.

  7. Fragments of Time

    DEFF Research Database (Denmark)

    Christiansen, Steen Ledet

    Time travel films necessarily fragment linear narratives, as scenes are revisited with differences from the first time we saw it. Popular films such as Back to the Future mine comedy from these visitations, but there are many different approaches. One extreme is Chris Marker's La Jetée - a film...... made almost completely of still images, recounting the end of the world. These stills can be viewed as fragments that have survived the end of the world and now provide the only access to the events that occured. Shane Carruth's Primer has a different approach to time travel, the narrative diegesis...... that is presented; how do we understand such films and to what extent is it even possible to make sense of a film that has no real beginning, middle or end?...

  8. Fragmentation of atomic systems

    International Nuclear Information System (INIS)

    Bohn, J.L.; Fano, U.

    1996-01-01

    We report recent progress toward a nonperturbative formulation of many-body quantum dynamics that treats all constituent particles on an equal footing. This formulation is capable of detailing the evolution of a system toward the diverse fragments into which it can break up. We illustrate the general concept with the simple example of the simultaneous excitation of both electrons in a helium atom. copyright 1996 The American Physical Society

  9. Modelling the fragmentation mechanisms

    International Nuclear Information System (INIS)

    Bougault, R.; Durand, D.; Gulminelli, F.

    1998-01-01

    We have investigated the role of high amplitude collective motion in the nuclear fragmentation by using semi-classical macroscopic, as well as, microscopic simulations (BUU). These studies are motivated by the search of instabilities responsible for nuclear fragmentation. Two cases were examined: the bubble formation following the collective expansion of the compressed nucleus in case of very central reactions and, in the case of the semi-central collisions, the fast fission of the two partners issued from a binary reaction, in their corresponding Coulomb field. In the two cases the fragmentation channel is dominated by the inter-relation between the Coulomb and nuclear fields, and it is possible to obtain semi-quantitative predictions as functions of interaction parameters. The transport equations of BUU type predicts for central reactions formation of a high density transient state. Of much interest is the mechanism subsequent to de-excitation. It seems reasonable to conceive that the pressure stocked in the compressional mode manifests itself as a collective expansion of the system. As the pressure is a increasing function of the available energy one can conceive a variety of energy depending exit channels, starting from the fragmentation due the amplification of fluctuations interior to the spinodal zone up to the complete vaporization of the highly excited system. If the reached pressure is sufficiently high the reaction final state may preserve the memory of the entrance channel as a collective radial energy superimposed to the thermal disordered motion. Distributions of particles in the configuration space for both central and semi-central reactions for the Pb+Au system are presented. The rupture time is estimated to the order of 300 fm/c, and is strongly dependent on the initial temperature. The study of dependence of the rupture time on the interaction parameters is under way

  10. Hot nuclei and fragmentation

    International Nuclear Information System (INIS)

    Guerreau, D.

    1993-01-01

    A review is made of the present status concerning the production of nuclei above 5 MeV temperature. Considerable progress has been made recently on the understanding of the formation and the fate of such hot nuclei. It appears that the nucleus seems more stable against temperature than predicted by static calculations. However, the occurrence of multifragment production at high excitation energies is now well established. The various experimental features of the fragmentation process are discussed. (author) 59 refs., 12 figs

  11. Excited nuclei fragmentation

    International Nuclear Information System (INIS)

    Ngo, C.

    1986-11-01

    Experimental indications leading to the thought of a very excited nucleus fragmentation are resumed. Theoretical approaches are briefly described; they are used to explain the phenomenon in showing off they are based on a minimum information principle. This model is based on time dependent Thomas-Fermi calculation which allows the mean field effect description, and with a site-bound percolation model which allows the fluctuation description [fr

  12. Azimuthal Anisotropies in Nuclear Fragmentation

    International Nuclear Information System (INIS)

    Dabrowska, A.; Szarska, M.; Trzupek, A.; Wolter, W.; Wosiek, B.

    2002-01-01

    The directed and elliptic flow of fragments emitted from the excited projectile nuclei has been observed for 158 AGeV Pb collisions with the lead and plastic targets. For comparison the flow analysis has been performed for 10.6 AGeV Au collisions with the emulsion target. The strong directed flow of heaviest fragments is found. Light fragments exhibit directed flow opposite to that of heavy fragments. The elliptic flow for all multiply charged fragments is positive and increases with the charge of the fragment. The observed flow patterns in the fragmentation of the projectile nucleus are practically independent of the mass of the target nucleus and the collision energy. Emission of fragments in nuclear multifragmentation shows similar, although weaker, flow effects. (author)

  13. Universality of projectile fragmentation model

    International Nuclear Information System (INIS)

    Chaudhuri, G.; Mallik, S.; Das Gupta, S.

    2012-01-01

    Presently projectile fragmentation reaction is an important area of research as it is used for the production of radioactive ion beams. In this work, the recently developed projectile fragmentation model with an universal temperature profile is used for studying the charge distributions of different projectile fragmentation reactions with different projectile target combinations at different incident energies. The model for projectile fragmentation consists of three stages: (i) abrasion, (ii) multifragmentation and (iii) evaporation

  14. Virtual fragment preparation for computational fragment-based drug design.

    Science.gov (United States)

    Ludington, Jennifer L

    2015-01-01

    Fragment-based drug design (FBDD) has become an important component of the drug discovery process. The use of fragments can accelerate both the search for a hit molecule and the development of that hit into a lead molecule for clinical testing. In addition to experimental methodologies for FBDD such as NMR and X-ray Crystallography screens, computational techniques are playing an increasingly important role. The success of the computational simulations is due in large part to how the database of virtual fragments is prepared. In order to prepare the fragments appropriately it is necessary to understand how FBDD differs from other approaches and the issues inherent in building up molecules from smaller fragment pieces. The ultimate goal of these calculations is to link two or more simulated fragments into a molecule that has an experimental binding affinity consistent with the additive predicted binding affinities of the virtual fragments. Computationally predicting binding affinities is a complex process, with many opportunities for introducing error. Therefore, care should be taken with the fragment preparation procedure to avoid introducing additional inaccuracies.This chapter is focused on the preparation process used to create a virtual fragment database. Several key issues of fragment preparation which affect the accuracy of binding affinity predictions are discussed. The first issue is the selection of the two-dimensional atomic structure of the virtual fragment. Although the particular usage of the fragment can affect this choice (i.e., whether the fragment will be used for calibration, binding site characterization, hit identification, or lead optimization), general factors such as synthetic accessibility, size, and flexibility are major considerations in selecting the 2D structure. Other aspects of preparing the virtual fragments for simulation are the generation of three-dimensional conformations and the assignment of the associated atomic point charges.

  15. An Archeology of Fragments

    Directory of Open Access Journals (Sweden)

    Gerald L. Bruns

    2014-10-01

    Full Text Available This is a short (fragmentary history of fragmentary writing from the German Romantics (F. W. Schlegel, Friedrich Hölderlin to modern and contemporary concrete or visual poetry. Such writing is (often deliberately a critique of the logic of subsumption that tries to assimilate whatever is singular and irreducible into totalities of various categorical or systematic sorts. Arguably, the fragment (parataxis is the distinctive feature of literary Modernism, which is a rejection, not of what precedes it, but of what Max Weber called “the rationalization of the world” (or Modernity whose aim is to keep everything, including all that is written, under surveillance and control.

  16. Heart Failure

    Science.gov (United States)

    ... Other diseases. Chronic diseases — such as diabetes, HIV, hyperthyroidism, hypothyroidism, or a buildup of iron (hemochromatosis) or ... transplantation or support with a ventricular assist device. Prevention The key to preventing heart failure is to ...

  17. Fragmentation processes in nuclear reactions

    International Nuclear Information System (INIS)

    Legrain, R.

    1984-08-01

    Projectile and nuclear fragmentation are defined and processes referred to are recalled. The two different aspects of fragmentation are considered but the emphasis is also put on heavy ion induced reactions. The preliminary results of an experiment performed at GANIL to study peripheral heavy ions induced reactions at intermediate energy are presented. The results of this experiment will illustrate the characteristics of projectile fragmentation and this will also give the opportunity to study projectile fragmentation in the transition region. Then nuclear fragmentation is considered which is associated with more central collisions in the case of heavy ion induced reactions. This aspect of fragmentation is also ilustrated with two heavy ion experiments in which fragments emitted at large angle have been observed

  18. Fragmentation of random trees

    International Nuclear Information System (INIS)

    Kalay, Z; Ben-Naim, E

    2015-01-01

    We study fragmentation of a random recursive tree into a forest by repeated removal of nodes. The initial tree consists of N nodes and it is generated by sequential addition of nodes with each new node attaching to a randomly-selected existing node. As nodes are removed from the tree, one at a time, the tree dissolves into an ensemble of separate trees, namely, a forest. We study statistical properties of trees and nodes in this heterogeneous forest, and find that the fraction of remaining nodes m characterizes the system in the limit N→∞. We obtain analytically the size density ϕ s of trees of size s. The size density has power-law tail ϕ s ∼s −α with exponent α=1+(1/m). Therefore, the tail becomes steeper as further nodes are removed, and the fragmentation process is unusual in that exponent α increases continuously with time. We also extend our analysis to the case where nodes are added as well as removed, and obtain the asymptotic size density for growing trees. (paper)

  19. Modeling Dynamic Anisotropic Behaviour and Spall Failure in Commercial Aluminium Alloys AA7010

    Science.gov (United States)

    Mohd Nor, M. K.; Ma'at, N.; Ho, C. S.

    2018-04-01

    This paper presents a finite strain constitutive model to predict a complex elastoplastic deformation behaviour involves very high pressures and shockwaves in orthotropic materials of aluminium alloys. The previous published constitutive model is used as a reference to start the development in this work. The proposed formulation that used a new definition of Mandel stress tensor to define Hill's yield criterion and a new shock equation of state (EOS) of the generalised orthotropic pressure is further enhanced with Grady spall failure model to closely predict shockwave propagation and spall failure in the chosen commercial aluminium alloy. This hyperelastic-plastic constitutive model is implemented as a new material model in the Lawrence Livermore National Laboratory (LLNL)-DYNA3D code of UTHM's version, named Material Type 92 (Mat92). The implementations of a new EOS of the generalised orthotropic pressure including the spall failure are also discussed in this paper. The capability of the proposed constitutive model to capture the complex behaviour of the selected material is validated against range of Plate Impact Test data at 234, 450 and 895 ms-1 impact velocities.

  20. Modelling Dynamic Behaviour and Spall Failure of Aluminium Alloy AA7010

    Science.gov (United States)

    Ma'at, N.; Nor, M. K. Mohd; Ismail, A. E.; Kamarudin, K. A.; Jamian, S.; Ibrahim, M. N.; Awang, M. K.

    2017-10-01

    A finite strain constitutive model to predict the dynamic deformation behaviour of Aluminium Alloy 7010 including shockwaves and spall failure is developed in this work. The important feature of this newly hyperelastic-plastic constitutive formulation is a new Mandel stress tensor formulated using new generalized orthotropic pressure. This tensor is combined with a shock equation of state (EOS) and Grady spall failure. The Hill’s yield criterion is adopted to characterize plastic orthotropy by means of the evolving structural tensors that is defined in the isoclinic configuration. This material model was developed and integration into elastic and plastic parts. The elastic anisotropy is taken into account through the newly stress tensor decomposition of a generalized orthotropic pressure. Plastic anisotropy is considered through yield surface and an isotropic hardening defined in a unique alignment of deviatoric plane within the stress space. To test its ability to describe shockwave propagation and spall failure, the new material model was implemented into the LLNL-DYNA3D code of UTHM’s. The capability of this newly constitutive model were compared against published experimental data of Plate Impact Test at 234m/s, 450m/s and 895m/s impact velocities. A good agreement is obtained between experimental and simulation in each test.

  1. Deformations and strain energy in fragments of tempered glass: experimental and numerical investigation

    DEFF Research Database (Denmark)

    Nielsen, Jens Henrik; Bjarrum, Marie

    2017-01-01

    energy and thereby the stress in a fragment post failure. The FE-model have been established in previous work Nielsen (Glass Struct Eng, 2016. doi: 10.1007/s40940-016-0036-z) and is applied here on the specific geometry and initial state of the investigated fragments. This is done by measuring...

  2. Fracture resistance of reattached incisor fragments with mini fibre-reinforced composite anchors.

    NARCIS (Netherlands)

    Fennis, W.M.M.; Kreulen, C.M.; Wolke, J.G.C.; Fokkinga, W.A.; Machado, C.; Creugers, N.H.J.

    2009-01-01

    OBJECTIVES: Fractured coronal fragments of incisors can be adhered to the remaining tooth with resin composite, but are prone to failure. This study explores whether mini fibre-reinforced composite (FRC) anchors increase fracture resistance of reattached fragments. METHODS: Forty-five extracted

  3. Fragment-based lead generation: identification of seed fragments by a highly efficient fragment screening technology

    Science.gov (United States)

    Neumann, Lars; Ritscher, Allegra; Müller, Gerhard; Hafenbradl, Doris

    2009-08-01

    For the detection of the precise and unambiguous binding of fragments to a specific binding site on the target protein, we have developed a novel reporter displacement binding assay technology. The application of this technology for the fragment screening as well as the fragment evolution process with a specific modelling based design strategy is demonstrated for inhibitors of the protein kinase p38alpha. In a fragment screening approach seed fragments were identified which were then used to build compounds from the deep-pocket towards the hinge binding area of the protein kinase p38alpha based on a modelling approach. BIRB796 was used as a blueprint for the alignment of the fragments. The fragment evolution of these deep-pocket binding fragments towards the fully optimized inhibitor BIRB796 included the modulation of the residence time as well as the affinity. The goal of our study was to evaluate the robustness and efficiency of our novel fragment screening technology at high fragment concentrations, compare the screening data with biochemical activity data and to demonstrate the evolution of the hit fragments with fast kinetics, into slow kinetic inhibitors in an in silico approach.

  4. Fragmented medial coronoid process

    International Nuclear Information System (INIS)

    Juhasz, Cs.; Juhasz, T.

    1997-01-01

    Fragmented medial coronoid process: (FCP) is often considered to be part of the osteochondrosis dissecans complex, but trauma and growth discrepancies between the radius and ulna are proposed as causes. There is little to clinically differentiate FCP, from osteochondrosis dissecans (OCD) of the elbow. Pain on, flexion-extension of the elbow and lateral rotation of the paw is a little more consistent in FCP. Radiographic examination of the elbow is important despite the, fact that radiographic signs of the FCP are often nonspecific. Excessive osteoarthrosis and superimposition of the radial head and coronoid process make identification of the FCP difficult. Craniocaudal, flexed mediolateral and 25 degree craniocaudal-lateromedial views are necessary for diagnosis. Osteophyte production is more dramatic with FCP than with OCD and suggests therefore the occurrence of OCP in many cases. Although the detached process may be seen on any view, the oblique projection offers the least obstructed view. Exposure of the joint is identical to that for OCD, that means a medial approach with osteotomy of the epicondyle. In most cases the process is loose enough to be readily apparent, but in some it is necessary to exert force on the process in order to find the cleavage plane. It is necessary to remove the osteophytes as well and to inspect and irrigate the joint carefully to remove cartilage fragments before closure. Confinement is advisable for 4 weeks before returning the dog to normal activity. The outlook for function is good if the FCP is removed before secondary degenerative joint disease is well established

  5. Fractal statistics of brittle fragmentation

    Directory of Open Access Journals (Sweden)

    M. Davydova

    2013-04-01

    Full Text Available The study of fragmentation statistics of brittle materials that includes four types of experiments is presented. Data processing of the fragmentation of glass plates under quasi-static loading and the fragmentation of quartz cylindrical rods under dynamic loading shows that the size distribution of fragments (spatial quantity is fractal and can be described by a power law. The original experimental technique allows us to measure, apart from the spatial quantity, the temporal quantity - the size of time interval between the impulses of the light reflected from the newly created surfaces. The analysis of distributions of spatial (fragment size and temporal (time interval quantities provides evidence of obeying scaling laws, which suggests the possibility of self-organized criticality in fragmentation.

  6. Fluctuations in the fragmentation process

    International Nuclear Information System (INIS)

    Botet, R.; Ploszajczak, M.

    1993-01-01

    Some general framework of sequential fragmentation is presented, as provided by the newly proposed Fragmentation - Inactivation - Binary model, and to study briefly its basic and universal features. This model includes as particular cases most of the previous kinetic fragmentation models. In particular it is discussed how one arrives in this framework to the critical behaviour, called the shattering transition. This model is then compared to recent data on gold multifragmentation at 600 MeV/nucl. (authors) 20 refs., 5 figs

  7. MRI of displaced meniscal fragments

    International Nuclear Information System (INIS)

    Dunoski, Brian; Zbojniewicz, Andrew M.; Laor, Tal

    2012-01-01

    A torn meniscus frequently requires surgical fixation or debridement as definitive treatment. Meniscal tears with associated fragment displacement, such as bucket handle and flap tears, can be difficult to recognize and accurately describe on MRI, and displaced fragments can be challenging to identify at surgery. A displaced meniscal fragment can be obscured by synovium or be in a location not usually evaluated at arthroscopy. We present a pictorial essay of meniscal tears with displaced fragments in patients referred to a pediatric hospital in order to increase recognition and accurate interpretation by the radiologist, who in turn can help assist the surgeon in planning appropriate therapy. (orig.)

  8. MRI of displaced meniscal fragments

    Energy Technology Data Exchange (ETDEWEB)

    Dunoski, Brian [University of Cincinnati College of Medicine, Department of Radiology, Cincinnati Children' s Hospital Medical Center, Cincinnati, OH (United States); Children' s Hospital of Michigan, Department of Radiology, Detroit, MI (United States); Zbojniewicz, Andrew M.; Laor, Tal [University of Cincinnati College of Medicine, Department of Radiology, Cincinnati Children' s Hospital Medical Center, Cincinnati, OH (United States)

    2012-01-15

    A torn meniscus frequently requires surgical fixation or debridement as definitive treatment. Meniscal tears with associated fragment displacement, such as bucket handle and flap tears, can be difficult to recognize and accurately describe on MRI, and displaced fragments can be challenging to identify at surgery. A displaced meniscal fragment can be obscured by synovium or be in a location not usually evaluated at arthroscopy. We present a pictorial essay of meniscal tears with displaced fragments in patients referred to a pediatric hospital in order to increase recognition and accurate interpretation by the radiologist, who in turn can help assist the surgeon in planning appropriate therapy. (orig.)

  9. Failure Modes

    DEFF Research Database (Denmark)

    Jakobsen, K. P.; Burcharth, H. F.; Ibsen, Lars Bo

    1999-01-01

    The present appendix contains the derivation of ten different limit state equations divided on three different failure modes. Five of the limit state equations can be used independently of the characteristics of the subsoil, whereas the remaining five can be used for either drained or undrained s...

  10. Thermodynamical string fragmentation

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, Nadine [Theoretical Particle Physics, Department of Astronomy and Theoretical Physics, Lund University,Sölvegatan 14A, Lund, SE-223 62 (Sweden); School of Physics and Astronomy, Monash University,Wellington Road, Clayton, VIC-3800 (Australia); Sjöstrand, Torbjörn [Theoretical Particle Physics, Department of Astronomy and Theoretical Physics, Lund University,Sölvegatan 14A, Lund, SE-223 62 (Sweden)

    2017-01-31

    The observation of heavy-ion-like behaviour in pp collisions at the LHC suggests that more physics mechanisms are at play than traditionally assumed. The introduction e.g. of quark-gluon plasma or colour rope formation can describe several of the observations, but as of yet there is no established paradigm. In this article we study a few possible modifications to the Pythia event generator, which describes a wealth of data but fails for a number of recent observations. Firstly, we present a new model for generating the transverse momentum of hadrons during the string fragmentation process, inspired by thermodynamics, where heavier hadrons naturally are suppressed in rate but obtain a higher average transverse momentum. Secondly, close-packing of strings is taken into account by making the temperature or string tension environment-dependent. Thirdly, a simple model for hadron rescattering is added. The effect of these modifications is studied, individually and taken together, and compared with data mainly from the LHC. While some improvements can be noted, it turns out to be nontrivial to obtain effects as big as required, and further work is called for.

  11. Types of Heart Failure

    Science.gov (United States)

    ... Introduction Types of Heart Failure Classes of Heart Failure Heart Failure in Children Advanced Heart Failure • Causes and ... and procedures related to heart disease and stroke. Heart Failure Questions to Ask Your Doctor Use these questions ...

  12. Classes of Heart Failure

    Science.gov (United States)

    ... Introduction Types of Heart Failure Classes of Heart Failure Heart Failure in Children Advanced Heart Failure • Causes and ... and Advanced HF • Tools and Resources • Personal Stories Heart Failure Questions to Ask Your Doctor Use these questions ...

  13. Polymer fragmentation in extensional flow

    Energy Technology Data Exchange (ETDEWEB)

    Maroja, Armando M.; Oliveira, Fernando A.; Ciesla, Michal; Longa, Lech

    2001-06-01

    In this paper we present an analysis of fragmentation of dilute polymer solutions in extensional flow. The transition rate is investigated both from theoretical and computational approaches, where the existence of a Gaussian distribution for the breaking bonds has been controversial. We give as well an explanation for the low fragmentation frequency found in DNA experiments.

  14. An Algebra for Program Fragments

    DEFF Research Database (Denmark)

    Kristensen, Bent Bruun; Madsen, Ole Lehrmann; Møller-Pedersen, Birger

    1985-01-01

    Program fragments are described either by strings in the concrete syntax or by constructor applications in the abstract syntax. By defining conversions between these forms, both may be intermixed. Program fragments are constructed by terminal and nonterminal symbols from the grammar and by variab...

  15. Mass spectrometry for fragment screening.

    Science.gov (United States)

    Chan, Daniel Shiu-Hin; Whitehouse, Andrew J; Coyne, Anthony G; Abell, Chris

    2017-11-08

    Fragment-based approaches in chemical biology and drug discovery have been widely adopted worldwide in both academia and industry. Fragment hits tend to interact weakly with their targets, necessitating the use of sensitive biophysical techniques to detect their binding. Common fragment screening techniques include differential scanning fluorimetry (DSF) and ligand-observed NMR. Validation and characterization of hits is usually performed using a combination of protein-observed NMR, isothermal titration calorimetry (ITC) and X-ray crystallography. In this context, MS is a relatively underutilized technique in fragment screening for drug discovery. MS-based techniques have the advantage of high sensitivity, low sample consumption and being label-free. This review highlights recent examples of the emerging use of MS-based techniques in fragment screening. © 2017 The Author(s). Published by Portland Press Limited on behalf of the Biochemical Society.

  16. Fission fragment spins and spectroscopy

    International Nuclear Information System (INIS)

    Durell, J.L.

    1988-01-01

    Prompt γ-ray coincidence experiments have been carried out on γ-rays emitted from post-neutron emission fission fragments produced by the aup 19F + 197 Au and 18 O + 232 Th reactions. Decay schemes have been established for even-even nuclei ranging from 78 Se to 148 Nd. Many new states with spin up to ∼ 12h have been observed. Apart from providing a wealth of new information on the spectroscopy of neutron-rich nuclei, the data have been analyzed to determine the average spin of primary fission fragments as a function of fragment mass. The results suggest that the fragment spins are determined by the temperature and shape of the primary fragments at or near to scission

  17. Fragment-based drug design.

    Science.gov (United States)

    Feyfant, Eric; Cross, Jason B; Paris, Kevin; Tsao, Désirée H H

    2011-01-01

    Fragment-based drug design (FBDD), which is comprised of both fragment screening and the use of fragment hits to design leads, began more than 15 years ago and has been steadily gaining in popularity and utility. Its origin lies on the fact that the coverage of chemical space and the binding efficiency of hits are directly related to the size of the compounds screened. Nevertheless, FBDD still faces challenges, among them developing fragment screening libraries that ensure optimal coverage of chemical space, physical properties and chemical tractability. Fragment screening also requires sensitive assays, often biophysical in nature, to detect weak binders. In this chapter we will introduce the technologies used to address these challenges and outline the experimental advantages that make FBDD one of the most popular new hit-to-lead process.

  18. Failure Analysis

    International Nuclear Information System (INIS)

    Iorio, A.F.; Crespi, J.C.

    1987-01-01

    After ten years of operation at the Atucha I Nuclear Power Station a gear belonging to a pressurized heavy water reactor refuelling machine, failed. The gear box was used to operate the inlet-outlet heavy-water valve of the machine. Visual examination of the gear device showed an absence of lubricant and that several gear teeth were broken at the root. Motion was transmitted with a speed-reducing device with controlled adjustable times in order to produce a proper fitness of the valve closure. The aim of this paper is to discuss the results of the gear failure analysis in order to recommend the proper solution to prevent further failures. (Author)

  19. Radioimmunoassay of an early plasmin degradation product of human fibrinogen, 'fragment A', and its clinical application

    Energy Technology Data Exchange (ETDEWEB)

    Takagi, K; Kawai, T [Jichi Medical School, Kawachi, Tochigi (Japan)

    1978-02-01

    Upon the plasmin digestion of human fibrinogen, an early cleavage product, which has been designated as fragment A, was isolated, and to study the action of plasmin in the circulation, radioimmunoassay for fragment A was carried out. This assay used rabbit immune serum obtained by injection of fragment A mixed with complete Freund's adjuvant, and fragment A was labelled with /sup 125/I using the Chloramin-T method. In 20 normal healthy donors its serum level was 3.57 +- 1.62..mu..g/ml (mean+-SD), and it was increased significantly in certain diseases, such as acute leukemias, candiovascular disorders, malignancies, renal failure, systemic lupus erythematosus and sepsis.

  20. Fragmentation cross sections outside the limiting-fragmentation regime

    CERN Document Server

    Sümmerer, K

    2003-01-01

    The empirical parametrization of fragmentation cross sections, EPAX, has been successfully applied to estimate fragment production cross sections in reactions of heavy ions at high incident energies. It is checked whether a similar parametrization can be found for proton-induced spallation around 1 GeV, the range of interest for ISOL-type RIB facilities. The validity of EPAX for medium-energy heavy-ion induced reactions is also checked. Only a few datasets are available, but in general EPAX predicts the cross sections rather well, except for fragments close to the projectile, where the experimental cross sections are found to be larger.

  1. Fragmentation functions approach in pQCD fragmentation phenomena

    International Nuclear Information System (INIS)

    Rolli, S.

    1996-07-01

    Next-to-leading order parton fragmentation functions into light mesons are presented. They have been extracted from real and simulated e + e - data and used to predict inclusive single particle distributions at different machines

  2. A model for projectile fragmentation

    International Nuclear Information System (INIS)

    Chaudhuri, G; Mallik, S; Gupta, S Das

    2013-01-01

    A model for projectile fragmentation is developed whose origin can be traced back to the Bevalac era. The model positions itself between the phenomenological EPAX parametrization and transport models like 'Heavy Ion Phase Space Exploration' (HIPSE) model and antisymmetrised molecular dynamics (AMD) model. A very simple impact parameter dependence of input temperature is incorporated in the model which helps to analyze the more peripheral collisions. The model is applied to calculate the charge, isotopic distributions, average number of intermediate mass fragments and the average size of largest cluster at different Z bound of different projectile fragmentation reactions at different energies.

  3. Gamma Radiation from Fission Fragments

    International Nuclear Information System (INIS)

    Higbie, Jack

    1969-10-01

    The gamma radiation from the fragments of the thermal neutron fission of 235 U has been investigated, and the preliminary data are presented here with suggestions for further lines of research and some possible interpretations of the data. The data have direct bearing on the fission process and the mode of fragment de-excitation. The parameters measured are the radiation decay curve for the time interval (1 - 7) x 10 -10 sec after fission, the photon yield, the total gamma ray energy yield, and the average photon energy. The last three quantities are measured as a function of the fragment mass

  4. Gamma Radiation from Fission Fragments

    Energy Technology Data Exchange (ETDEWEB)

    Higbie, Jack

    1969-10-15

    The gamma radiation from the fragments of the thermal neutron fission of {sup 235}U has been investigated, and the preliminary data are presented here with suggestions for further lines of research and some possible interpretations of the data. The data have direct bearing on the fission process and the mode of fragment de-excitation. The parameters measured are the radiation decay curve for the time interval (1 - 7) x 10{sup -10} sec after fission, the photon yield, the total gamma ray energy yield, and the average photon energy. The last three quantities are measured as a function of the fragment mass.

  5. The spectroscopy of fission fragments

    Energy Technology Data Exchange (ETDEWEB)

    Phillips, W.R. [Department of Physics and Astronomy, University of Manchester, Manchester, M13 9PL (United Kingdom); Collaboration: La Direction des Sciences de la Matiere du CEA (FR); Le Fonds National de la Recherche Scientifique de Belgique (BE)

    1998-12-31

    High-resolution measurements on {gamma} rays from fission fragments have provided a rich source of information, unobtainable at the moment in any other way, on the spectroscopy of neutron-rich nuclei. In recent years important data have been obtained on the yrast- and near yrast-structure of neutron-rich fission fragments. We discuss the scope of measurements which can be made on prompt gamma rays from secondary fission fragments, the techniques used in the experiments and some results recently obtained. (author) 24 refs., 8 figs., 1 tab.

  6. The spectroscopy of fission fragments

    International Nuclear Information System (INIS)

    Phillips, W.R.

    1998-01-01

    High-resolution measurements on γ rays from fission fragments have provided a rich source of information, unobtainable at the moment in any other way, on the spectroscopy of neutron-rich nuclei. In recent years important data have been obtained on the yrast- and near yrast-structure of neutron-rich fission fragments. We discuss the scope of measurements which can be made on prompt gamma rays from secondary fission fragments, the techniques used in the experiments and some results recently obtained. (author)

  7. Radioisotope thermoelectric generator/thin fragment impact test

    International Nuclear Information System (INIS)

    Reimus, M.A.H.; Hinckley, J.E.

    1998-01-01

    The General-Purpose Heat Source (GPHS) provides power for space missions by transmitting the heat of 238 Pu decay to an array of thermoelectric elements in a radioisotope thermoelectric generator (RTG). Because the potential for a launch abort or return from orbit exists for any space mission, the heat source response to credible accident scenarios is being evaluated. This test was designed to provide information on the response of a loaded RTG to impact by a fragment similar to the type of fragment produced by breakup of the spacecraft propulsion module system (PMS). The results of this test indicated that impact of the RTG by a thin aluminum fragment traveling at 306 m/s may result in significant damage to the convertor housing, failure of one fueled clad, and release of a small quantity of fuel

  8. FRAGMENTATION ISSUE IN MALAYSIAN INDUSTRIALISED BUILDING SYSTEM (IBS PROJECTS

    Directory of Open Access Journals (Sweden)

    MOHD NASRUN MOHD NAWI

    2014-02-01

    Full Text Available As a developing country, Malaysian is currently driving for implementing a new or modern construction method, the Industrialised Building System (IBS, as an alternative towards enhancing construction performance. Currently, most of the IBS project developments in Malaysia are still conducted by using the traditional construction process approach. This traditional construction process has been widely criticised for its fragmented approach to project delivery and its failure to form effective teams thus created a number of issues such as reworks, time delay, rising costs, lack of communication and coordination, and wastages. This paper through literature review aims to highlight this fragmentation issue and clarify how far it affects the process of IBS implementation. Suggestions on how an integrated approach in design and construction in order to minimise the fragmentation gaps will be concluded.

  9. Heart failure - tests

    Science.gov (United States)

    CHF - tests; Congestive heart failure - tests; Cardiomyopathy - tests; HF - tests ... the best test to: Identify which type of heart failure (systolic, diastolic, valvular) Monitor your heart failure and ...

  10. Analysis methods for Kevlar shield response to rotor fragments

    Science.gov (United States)

    Gerstle, J. H.

    1977-01-01

    Several empirical and analytical approaches to rotor burst shield sizing are compared and principal differences in metal and fabric dynamic behavior are discussed. The application of transient structural response computer programs to predict Kevlar containment limits is described. For preliminary shield sizing, present analytical methods are useful if insufficient test data for empirical modeling are available. To provide other information useful for engineering design, analytical methods require further developments in material characterization, failure criteria, loads definition, and post-impact fragment trajectory prediction.

  11. The dynamics of fragment formation

    International Nuclear Information System (INIS)

    Keane, D.

    1994-09-01

    We demonstrate that in the Quantum Molecular Dynamics model, dynamical correlations can result in the production rate for final state nucleon clusters (and hence composite fragments) being higher than would be expected if statistics and the available phase space were dominant in determining composite formation. An intranuclear cascade or a Boltzmann-Uehling-Uhlenbeck model, combined with a statistical approach in the late stage of the collision to determine composites, provides an equivalent description only under limited conditions of centrality and beam energy. We use data on participant fragment production in Au + Au collisions in the Bevalac's BOS time projection chamber to map out the parameter space where statistical clustering provides a good description. In particular, we investigate momentum-space densities of fragments up to 4 He as a function of fragment transverse momentum, azimuth relative to the reaction plane, rapidity, multiplicity and beam energy

  12. Chemical Production using Fission Fragments

    International Nuclear Information System (INIS)

    Dawson, J. K.; Moseley, F.

    1960-01-01

    Some reactor design considerations of the use of fission recoil fragment energy for the production of chemicals of industrial importance have been discussed previously in a paper given at the Second United Nations International Conference on the Peaceful Uses of Atomic Energy [A/Conf. 15/P.76]. The present paper summarizes more recent progress made on this topic at AERE, Harwell. The range-energy relationship for fission fragments is discussed in the context of the choice of fuel system for a chemical production reactor, and the experimental observation of a variation of chemical effect along the length of a fission fragment track is described for the irradiation of nitrogen-oxygen mixtures. Recent results are given on the effect of fission fragments on carbon monoxide-hydrogen gas mixtures and on water vapour. No system investigated to date shows any outstanding promise for large-scale chemical production. (author) [fr

  13. QGP and Modified Jet Fragmentation

    International Nuclear Information System (INIS)

    Wang, Xin-Nian

    2005-01-01

    Recent progresses in the study of jet modification in hotmedium and their consequences in high-energy heavy-ion collisions are reviewed. In particular, I will discuss energy loss for propagating heavy quarks and the resulting modified fragmentation function. Medium modification of the parton fragmentation function due to quark recombination are formulated within finite temperature field theory and their implication on the search for deconfined quark-gluon plasma is also discussed

  14. Robust Object Tracking Using Valid Fragments Selection.

    Science.gov (United States)

    Zheng, Jin; Li, Bo; Tian, Peng; Luo, Gang

    Local features are widely used in visual tracking to improve robustness in cases of partial occlusion, deformation and rotation. This paper proposes a local fragment-based object tracking algorithm. Unlike many existing fragment-based algorithms that allocate the weights to each fragment, this method firstly defines discrimination and uniqueness for local fragment, and builds an automatic pre-selection of useful fragments for tracking. Then, a Harris-SIFT filter is used to choose the current valid fragments, excluding occluded or highly deformed fragments. Based on those valid fragments, fragment-based color histogram provides a structured and effective description for the object. Finally, the object is tracked using a valid fragment template combining the displacement constraint and similarity of each valid fragment. The object template is updated by fusing feature similarity and valid fragments, which is scale-adaptive and robust to partial occlusion. The experimental results show that the proposed algorithm is accurate and robust in challenging scenarios.

  15. Recent progress on perturbative QCD fragmentation functions

    International Nuclear Information System (INIS)

    Cheung, K.

    1995-05-01

    The recent development of perturbative QCD (PQCD) fragmentation functions has strong impact on quarkonium production. I shall summarize B c meson production based on these PQCD fragmentation functions, as well as, the highlights of some recent activities on applying these PQCD fragmentation functions to explain anomalous J/ψ and ψ' production at the Tevatron. Finally, I discuss a fragmentation model based on the PQCD fragmentation functions for heavy quarks fragmenting into heavy-light mesons

  16. Heart failure - home monitoring

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/patientinstructions/000113.htm Heart failure - home monitoring To use the sharing features on ... your high blood pressure Fast food tips Heart failure - discharge Heart failure - fluids and diuretics Heart failure - what to ...

  17. Fragmentation of rotating protostellar clouds

    International Nuclear Information System (INIS)

    Tohline, J.E.

    1980-01-01

    We examine, with a three-dimensional hydrodynamic computer code, the behavior of rotating, isothermal gas clouds as they collapse from Jeans unstable configurations, in order to determine whether they are susceptible to fragmentation during the initial dynamic collapse phase of their evolution. We find that a gas cloud will not fragment unless (a) it begins collapsing from a radius much smaller than the Jeans radius (i.e., the cloud initially encloses many Jeans masses) and (b) irregularities in the cloud's initial structure (specifically, density inhomogeneities) enclose more than one Jeans mass of material. Gas pressure smooths out features that are not initially Jeans unstable while rotation plays no direct role in damping inhomogeneities. Instead of fragmenting, most of our models collapse to a ring configuration (as has been observed by other investigators in two-dimensional, axisymmetric models). The rings appear to be less susceptible to gragmentation from arbitrary perturbations in their structure than has previously been indicated in other work. Because our models, which include the effects of gas pressure, do not readily fragment during a phase of dynamic collapse, we suggest that gas clouds in the galactic disk undergo fragmentation only during quasi-equilibrium phases of their evolution

  18. Memory effects in nuclear fragmentation?

    International Nuclear Information System (INIS)

    Colonna, M.; Di Toro, M.; Guarnera, A.

    1994-01-01

    A general procedure to identify instability regions which lead to multifragmentation events is presented. The dominant mode at the instability point is determined from the knowledge of the mean properties (density and temperature) of the system at that point. For spinodal instabilities the dependence of fragment structures on the dynamical conditions is studied changing the beam energy and the considered equation of state. An important competition between two dynamical effects, expansion of the system and growth of fluctuations, is revealed. It is shown that in heavy-ion central collisions at medium energies memory effects of the configuration formed at the instability time could be observed in the final fragmentation pattern. Some hints towards a fully dynamical picture of fragmentation processes are finally suggested. ((orig.))

  19. Fragmentation properties of 6Li

    International Nuclear Information System (INIS)

    Lovas, R.G.; Kruppa, A.T.; Beck, R.; Dickmann, F.

    1987-01-01

    The α+d and t+τ cluster structure of 6 Li is described in a microscopic α+d cluster model through quantities that enter into the description of cluster fragmentation processes. The states of the separate clusters α, d, t and τ are described as superpositions of Os Slater determinants belonging to different potential size parameters. To describe both the 6 Li and fragment state realistically, nucleon-nucleon forces optimized for the used model state spaces were constructed. The fragmentation properties predicted by them slightly differ from those calculated with some forces of common use provided the latter are modified so as to reproduce the α, d and 6 Li energies. (author) 61 refs.; 9 figs

  20. Hands as markers of fragmentation

    Directory of Open Access Journals (Sweden)

    A. Barnard

    2005-07-01

    Full Text Available Margaret Atwood is an internationally read, translated, and critiqued writer whose novels have established her as one of the most esteemed authors in English (McCombs & Palmer, 1991:1. Critical studies of her work deal mainly with notions of identity from psychoanalytical perspectives. This study has identified a gap in current critical studies on Atwood’s works, namely the challenging of textual unity which is paralleled in the challenging of the traditional (single narrative voice. The challenging of textual unity and the single narrative voice brings about the fragmentation of both. This article will focus on the role that hands play as markers of fragmentation in “The Blind Assassin” (2000. In the novel, the writing hand destabilises the narrative voice, since it is not connected to the voice of a single author. If the author of the text – the final signified – is eliminated, the text becomes fragmentary and open, inviting the reader to contribute to the creation of meaning. Hands play a signficant role in foregrounding the narrator’s fragmented identity, and consequently, the fragmentation of the text. We will investigate this concept in the light of Roland Barthes’ notion of the scriptor, whose hand is metaphorically severed from his or her “voice”. Instead of the text being a unified entity, it becomes unstable and it displays the absence of hierarchical textual levels. Based mainly on Barthes’ writings, this article concludes that hands foreground the narrator’s fragmented identity, which is paralleled in the fragmented text.

  1. Fragmentation processes in nuclear reactions

    International Nuclear Information System (INIS)

    Baur, G.; Roesel, F.; Trautmann, D.; Shyam, R.

    1983-10-01

    Fragmentation processes in nuclear collisions are reviewed. The main emphasis is put on light ion breakup at nonrelativistic energies. The post- and prior-form DWBA theories are discussed. The post-form DWBA, appropriate for the ''spectator breakup'' describes elastic as well as inelastic breakup modes. This theory can also account for the stripping to unbound states. The theoretical models are compared to typical experimental results to illustrate the various possible mechanisms. It is discussed, how breakup reactions can be used to study high-lying single particle strength in the continuum; how it can yield information about momentum distributions of fragments in the nucleus. (orig.)

  2. Refolding Technologies for Antibody Fragments

    Directory of Open Access Journals (Sweden)

    Tsutomu Arakawa

    2014-05-01

    Full Text Available Refolding is one of the production technologies for pharmaceutical grade antibody fragments. Detergents and denaturants are primarily used to solubilize the insoluble proteins. The solubilized and denatured proteins are refolded by reducing the concentration of the denaturants or detergents. Several refolding technologies have been used for antibody fragments, comprising dilution, dialysis, solid phase solvent exchange and size exclusion chromatography, as reviewed here. Aggregation suppressor or folding-assisting agents, including arginine hydrochloride, ionic liquids and detergents or denaturants at low concentrations, are included in the refolding solvent to enhance refolding yield.

  3. Fragmentation of atomic clusters: A theoretical study

    International Nuclear Information System (INIS)

    Lopez, M.J.; Jellinek, J.

    1994-01-01

    Collisionless fragmentation of nonrotating model n-atom metal clusters (n=12, 13, and 14) is studied using isoergic molecular-dynamics simulations. Minimum-energy paths for fragmentation are mapped out as functions of the distance between the centers of mass of the fragments. These paths provide information on the fragmentation energies for the different fragmentation channels. Fragmentation patterns (distributions of the fragmentation channel probabilities) and global and channel-specific fragmentation rate constants are computed and analyzed as functions of the internal energy and of the size of the clusters. The trends derived from the dynamics are compared with those obtained using the RRK and TST statistical approaches. The dynamics of the fragmentation process is analyzed in terms of characteristic quantities such as the distance between the centers of mass of the fragments, their relative translational energy, and their interaction energy, all considered as functions of time

  4. Nuclear energy release from fragmentation

    Energy Technology Data Exchange (ETDEWEB)

    Li, Cheng [The Key Laboratory of Beam Technology and Material Modification of Ministry of Education, College of Nuclear Science and Technology, Beijing Normal University, Beijing 100875 (China); Beijing Radiation Center, Beijing 100875 (China); Souza, S.R. [Instituto de Física, Universidade Federal do Rio de Janeiro Cidade Universitária, Caixa Postal 68528, 21945-970 Rio de Janeiro (Brazil); Tsang, M.B. [The Key Laboratory of Beam Technology and Material Modification of Ministry of Education, College of Nuclear Science and Technology, Beijing Normal University, Beijing 100875 (China); Beijing Radiation Center, Beijing 100875 (China); National Superconducting Cyclotron Laboratory and Physics and Astronomy Department, Michigan State University, East Lansing, MI 48824 (United States); Zhang, Feng-Shou, E-mail: fszhang@bnu.edu.cn [The Key Laboratory of Beam Technology and Material Modification of Ministry of Education, College of Nuclear Science and Technology, Beijing Normal University, Beijing 100875 (China); Beijing Radiation Center, Beijing 100875 (China); Center of Theoretical Nuclear Physics, National Laboratory of Heavy Ion Accelerator of Lanzhou, Lanzhou 730000 (China)

    2016-08-15

    It is well known that binary fission occurs with positive energy gain. In this article we examine the energetics of splitting uranium and thorium isotopes into various numbers of fragments (from two to eight) with nearly equal size. We find that the energy released by splitting {sup 230,232}Th and {sup 235,238}U into three equal size fragments is largest. The statistical multifragmentation model (SMM) is applied to calculate the probability of different breakup channels for excited nuclei. By weighing the probability distributions of fragment multiplicity at different excitation energies, we find the peaks of energy release for {sup 230,232}Th and {sup 235,238}U are around 0.7–0.75 MeV/u at excitation energy between 1.2 and 2 MeV/u in the primary breakup process. Taking into account the secondary de-excitation processes of primary fragments with the GEMINI code, these energy peaks fall to about 0.45 MeV/u.

  5. Fission fragment driven neutron source

    Science.gov (United States)

    Miller, Lowell G.; Young, Robert C.; Brugger, Robert M.

    1976-01-01

    Fissionable uranium formed into a foil is bombarded with thermal neutrons in the presence of deuterium-tritium gas. The resulting fission fragments impart energy to accelerate deuterium and tritium particles which in turn provide approximately 14 MeV neutrons by the reactions t(d,n).sup.4 He and d(t,n).sup.4 He.

  6. Developments in SPR Fragment Screening.

    Science.gov (United States)

    Chavanieu, Alain; Pugnière, Martine

    2016-01-01

    Fragment-based approaches have played an increasing role alongside high-throughput screening in drug discovery for 15 years. The label-free biosensor technology based on surface plasmon resonance (SPR) is now sensitive and informative enough to serve during primary screens and validation steps. In this review, the authors discuss the role of SPR in fragment screening. After a brief description of the underlying principles of the technique and main device developments, they evaluate the advantages and adaptations of SPR for fragment-based drug discovery. SPR can also be applied to challenging targets such as membrane receptors and enzymes. The high-level of immobilization of the protein target and its stability are key points for a relevant screening that can be optimized using oriented immobilized proteins and regenerable sensors. Furthermore, to decrease the rate of false negatives, a selectivity test may be performed in parallel on the main target bearing the binding site mutated or blocked with a low-off-rate ligand. Fragment-based drug design, integrated in a rational workflow led by SPR, will thus have a predominant role for the next wave of drug discovery which could be greatly enhanced by new improvements in SPR devices.

  7. Nuclear fragmentation by nucleation approach

    International Nuclear Information System (INIS)

    Chung, K.C.

    1992-01-01

    The nucleation model is used to simulate nuclear fragmentation processes. The critical value of the effective interaction radius is shown to vary linearly with the expansion factor α. The calculated mass and charge distributions are compared with some experimental data. (author)

  8. Neutron multiplicity of fission fragments

    Energy Technology Data Exchange (ETDEWEB)

    Abdelrahman, Y S [Physics department, mu` rah university Al-Karak, (Jordan)

    1995-10-01

    The total average neutron multiplicity of the fission fragments produced by the spontaneous fission of {sup 248} Cm has been measured. This measurement has been done by using a new experimental technique. This technique mainly depends on {gamma}-{gamma} coincidence using a very high resolution high purity germanium (HPGe) detector. 2 figs.

  9. Fragmented nature: consequences for biodiversity

    NARCIS (Netherlands)

    Olff, H.; Ritchie, M.E.

    2002-01-01

    We discuss how fragmentation of resources and habitat operate differently on species diversity across spatial scales, ranging from positive effects on local species coexistence to negative effect on intermediate spatial scales, to again positive effects on large spatial and temporal scales. Species

  10. Fragmented nature : consequences for biodiversity

    NARCIS (Netherlands)

    Olff, Han; Ritchie, Mark E.

    2002-01-01

    We discuss how fragmentation of resources and habitat operate differently on species diversity across spatial scales, ranging from positive effects on local species coexistence to negative effect on intermediate spatial scales, to again positive effects on large spatial and temporal scales. Species

  11. Research of nuclear fragmentation characteristics

    International Nuclear Information System (INIS)

    Richert, J.

    1989-01-01

    Motivations for the study of nuclear fragmentation are presented. Different models and methods which were developed in the past are reviewed, critically discussed and confronted in connection with the experimental information gathered over the past years. Specific aspects related to the onset of the process, its characteristics and the mechanism which governs it are discussed [fr

  12. FRAGMENTED IDENTITIES: THE CULTURAL COLLISION ...

    African Journals Online (AJOL)

    User

    Born in the former French and German colony of. Togo, Komla-Ebri ... of how cultural barriers not only lead to isolation and fragmented identities, but also ..... and, in recreating bits of Italy, in the form of music, cinema and food, absorbs parts of ...

  13. Phthalocyanides sensitized fragmentation of proteins

    Czech Academy of Sciences Publication Activity Database

    Klementová, S.; Tothová, D.; Revaková, R.; Kasková, M.; Wagnerová, Dana Marie

    2001-01-01

    Roč. 5, č. 1 (2001), s. 13-18 ISSN 0972-0626 R&D Projects: GA ČR GA203/96/1322 Institutional research plan: CEZ:AV0Z4032918 Keywords : phthalocyanides * photosensitied fragmentation of proteins Subject RIV: CA - Inorganic Chemistry

  14. The VERDI fission fragment spectrometer

    Directory of Open Access Journals (Sweden)

    Frégeau M.O.

    2013-12-01

    Full Text Available The VERDI time-of-flight spectrometer is dedicated to measurements of fission product yields and of prompt neutron emission data. Pre-neutron fission-fragment masses will be determined by the double time-of-flight (TOF technique. For this purpose an excellent time resolution is required. The time of flight of the fragments will be measured by electrostatic mirrors located near the target and the time signal coming from silicon detectors located at 50 cm on both sides of the target. This configuration, where the stop detector will provide us simultaneously with the kinetic energy of the fragment and timing information, significantly limits energy straggling in comparison to legacy experimental setup where a thin foil was usually used as a stop detector. In order to improve timing resolution, neutron transmutation doped silicon will be used. The high resistivity homogeneity of this material should significantly improve resolution in comparison to standard silicon detectors. Post-neutron fission fragment masses are obtained form the time-of-flight and the energy signal in the silicon detector. As an intermediary step a diamond detector will also be used as start detector located very close to the target. Previous tests have shown that poly-crystalline chemical vapour deposition (pCVD diamonds provides a coincidence time resolution of 150 ps not allowing complete separation between very low-energy fission fragments, alpha particles and noise. New results from using artificial single-crystal diamonds (sCVD show similar time resolution as from pCVD diamonds but also sufficiently good energy resolution.

  15. Percutaneous transhepatic fragmentation of gall stones and extraction of fragments

    International Nuclear Information System (INIS)

    Guenther, R.; Klose, K.; Schmidt, H.D.; Staritz, M.; Mainz Univ.; Mainz Univ.

    1983-01-01

    Attempts at percutaneous removal have been made in 13 patients with solitary and multiple intra- and extra-hepatic biliary duct stones measuring 5 to 30 mm. The stones were fragmented with a Dormia basket and the fragments removed transhepatically. In ten patients the procedure was successful, including one patient with multiple intra-hepatic stones. The procedure can be recommended for cases of calculous obstruction of biliary anastomoses or of stones which could not be removed by endoscopy, or where there is already biliary drainage being carried out, or in patients with a high opertive risk. In two patients, dilatation of the papilla was also carried out, in four patients a stenosis was dilated and in a further two patients, electro-incision of a stenosis was performed. (orig.) [de

  16. Fragments

    Science.gov (United States)

    Moreira, Claudio

    2008-01-01

    This performance autoethnography shows the author's struggle in finding his place, scholarship, voice, and body, into the academic setting. Mixing together memories of his lived experience with sugar cane workers, notes, and leftovers of different fieldworks, plus 6 years of life as grad student at the University of Illinois, the author looks for…

  17. Fragmentation

    Science.gov (United States)

    K.H. Riitters

    2009-01-01

    Effective resource management takes into account the administrative and biophysical settings within which natural resources occur. A setting may be described in many ways; for example, by forest land ownership, by reserved and roadless designation, or by the distribution of human populations in relation to forest (chapter 3). The physical arrangement of forest in a...

  18. Energy production using fission fragment rockets

    International Nuclear Information System (INIS)

    Chapline, G.; Matsuda, Y.

    1991-08-01

    Fission fragment rockets are nuclear reactors with a core consisting of thin fibers in a vacuum, and which use magnetic fields to extract the fission fragments from the reactor core. As an alternative to ordinary nuclear reactors, fission fragment rockets would have the following advantages: Approximately twice as efficient if one can directly convert the fission fragment energy into electricity; by reducing the buildup of a fission fragment inventory in the reactor one could avoid a Chernobyl type disaster; and collecting the fission fragments outside the reactor could simplify the waste disposal problem. 6 refs., 4 figs., 2 tabs

  19. Heart failure - medicines

    Science.gov (United States)

    CHF - medicines; Congestive heart failure - medicines; Cardiomyopathy - medicines; HF - medicines ... You will need to take most of your heart failure medicines every day. Some medicines are taken ...

  20. Fragmentation of suddenly heated liquids

    International Nuclear Information System (INIS)

    Blink, J.A.

    1985-03-01

    Fragmentation of free liquids in Inertial Confinement Fusion reactors could determine the upper bound on reactor pulse rate. The x-ray ablated materials must cool and recondense to allow driver beam propagation. The increased surface area caused by fragmentation will enhance the cooling and condensation rates. Relaxation from the suddenly heated state will move a liquid into the negative pressure region under the liquid-vapor P-V dome. The lithium equation of state was used to demonstrate that neutron-induced vaporization uses only a minor fraction of the added heat, much less than would be required to drive the expansion. A 77% expansion of the lithium is required before the rapid vaporization process of spinodal decomposition could begin, and nucleation and growth are too slow to contribute to the expansion

  1. Fragment separator momentum compression schemes

    Energy Technology Data Exchange (ETDEWEB)

    Bandura, Laura, E-mail: bandura@anl.gov [Facility for Rare Isotope Beams (FRIB), 1 Cyclotron, East Lansing, MI 48824-1321 (United States); National Superconducting Cyclotron Lab, Michigan State University, 1 Cyclotron, East Lansing, MI 48824-1321 (United States); Erdelyi, Bela [Argonne National Laboratory, Argonne, IL 60439 (United States); Northern Illinois University, DeKalb, IL 60115 (United States); Hausmann, Marc [Facility for Rare Isotope Beams (FRIB), 1 Cyclotron, East Lansing, MI 48824-1321 (United States); Kubo, Toshiyuki [RIKEN Nishina Center, RIKEN, Wako (Japan); Nolen, Jerry [Argonne National Laboratory, Argonne, IL 60439 (United States); Portillo, Mauricio [Facility for Rare Isotope Beams (FRIB), 1 Cyclotron, East Lansing, MI 48824-1321 (United States); Sherrill, Bradley M. [National Superconducting Cyclotron Lab, Michigan State University, 1 Cyclotron, East Lansing, MI 48824-1321 (United States)

    2011-07-21

    We present a scheme to use a fragment separator and profiled energy degraders to transfer longitudinal phase space into transverse phase space while maintaining achromatic beam transport. The first order beam optics theory of the method is presented and the consequent enlargement of the transverse phase space is discussed. An interesting consequence of the technique is that the first order mass resolving power of the system is determined by the first dispersive section up to the energy degrader, independent of whether or not momentum compression is used. The fragment separator at the Facility for Rare Isotope Beams is a specific application of this technique and is described along with simulations by the code COSY INFINITY.

  2. Fragment separator momentum compression schemes

    International Nuclear Information System (INIS)

    Bandura, Laura; Erdelyi, Bela; Hausmann, Marc; Kubo, Toshiyuki; Nolen, Jerry; Portillo, Mauricio; Sherrill, Bradley M.

    2011-01-01

    We present a scheme to use a fragment separator and profiled energy degraders to transfer longitudinal phase space into transverse phase space while maintaining achromatic beam transport. The first order beam optics theory of the method is presented and the consequent enlargement of the transverse phase space is discussed. An interesting consequence of the technique is that the first order mass resolving power of the system is determined by the first dispersive section up to the energy degrader, independent of whether or not momentum compression is used. The fragment separator at the Facility for Rare Isotope Beams is a specific application of this technique and is described along with simulations by the code COSY INFINITY.

  3. Asymmetry effects in fragment production

    Energy Technology Data Exchange (ETDEWEB)

    Kaur, Manpreet [Sri Guru Granth Sahib World University, Fatehgarh Sahib-140406, Punjab (India); Kaur, Varinderjit, E-mail: drvarinderjit@gmail.com [Mata Gujri College, Fatehgarh Sahib-140406, Punjab (India)

    2016-05-06

    The production of different fragments has been studied by taking into account the mass asymmetry of the reaction and employing the momentum dependent interactions. Two different set of asymmetric reactions have been analyzed while keeping At{sub otal} fixed using soft momentum dependent equation of state. Our results indicate that the impact of momentum dependent interactions is different in lighter projectile systems as compared to heavier ones. The comparative analysis of IQMD simulations with the experimental data in case of heavier projectile and lighter target system for the reaction of {sup 197}Au+{sup 27}Al (η = 0.7) at E = 600 MeV/nucleon shows that with the inclusion of MDI we are able, upto some extent, to reproduce the experimental universality of rise and fall of intermediate mass fragments (IMFs).

  4. Fragmentation of percolation cluster perimeters

    Science.gov (United States)

    Debierre, Jean-Marc; Bradley, R. Mark

    1996-05-01

    We introduce a model for the fragmentation of porous random solids under the action of an external agent. In our model, the solid is represented by a bond percolation cluster on the square lattice and bonds are removed only at the external perimeter (or `hull') of the cluster. This model is shown to be related to the self-avoiding walk on the Manhattan lattice and to the disconnection events at a diffusion front. These correspondences are used to predict the leading and the first correction-to-scaling exponents for several quantities defined for hull fragmentation. Our numerical results support these predictions. In addition, the algorithm used to construct the perimeters reveals itself to be a very efficient tool for detecting subtle correlations in the pseudo-random number generator used. We present a quantitative test of two generators which supports recent results reported in more systematic studies.

  5. Analysis of Blade Fragment Risk at a Wind Energy Facility

    Energy Technology Data Exchange (ETDEWEB)

    Simms, David A [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Larwood, Scott [University of the Pacific

    2018-04-06

    An analysis was performed to determine the risk posed by wind turbine fragments on roads and buildings at the National Wind Technology Center at the National Renewable Energy Laboratory. The authors used a previously developed model of fragment trajectory and took into account the wind speed/direction distribution at the site and the probability of rotor failure. The risk was assessed by determining the likelihood of impact and related consequences. For both the roads and buildings, the risk varied from low to routine, which was considered acceptable. The analysis was compared with previous recommendations on wind turbine setback distances. The results showed that a setback to property lines of 2 times the overall turbine height would be acceptable. However, the setback to dwellings should probably be increased from 3 to 3.5 times the overall turbine height for an acceptable risk.

  6. Fragmented nature: consequences for biodiversity

    OpenAIRE

    Olff, Han; Ritchie, Mark E.

    2002-01-01

    We discuss how fragmentation of resources and habitat operate differently on species diversity across spatial scales, ranging from positive effects on local species coexistence to negative effect on intermediate spatial scales, to again positive effects on large spatial and temporal scales. Species with different size and mobility can be regulated by different processes at the same spatial scale, a principle that may contribute to diversity. Differences in species richness between local commu...

  7. Telomere Restriction Fragment (TRF) Analysis.

    Science.gov (United States)

    Mender, Ilgen; Shay, Jerry W

    2015-11-20

    While telomerase is expressed in ~90% of primary human tumors, most somatic tissue cells except transiently proliferating stem-like cells do not have detectable telomerase activity (Shay and Wright, 1996; Shay and Wright, 2001). Telomeres progressively shorten with each cell division in normal cells, including proliferating stem-like cells, due to the end replication (lagging strand synthesis) problem and other causes such as oxidative damage, therefore all somatic cells have limited cell proliferation capacity (Hayflick limit) (Hayflick and Moorhead, 1961; Olovnikov, 1973). The progressive telomere shortening eventually leads to growth arrest in normal cells, which is known as replicative senescence (Shay et al. , 1991). Once telomerase is activated in cancer cells, telomere length is stabilized by the addition of TTAGGG repeats to the end of chromosomes, thus enabling the limitless continuation of cell division (Shay and Wright, 1996; Shay and Wright, 2001). Therefore, the link between aging and cancer can be partially explained by telomere biology. There are many rapid and convenient methods to study telomere biology such as Telomere Restriction Fragment (TRF), Telomere Repeat Amplification Protocol (TRAP) (Mender and Shay, 2015b) and Telomere dysfunction Induced Foci (TIF) analysis (Mender and Shay, 2015a). In this protocol paper we describe Telomere Restriction Fragment (TRF) analysis to determine average telomeric length of cells. Telomeric length can be indirectly measured by a technique called Telomere Restriction Fragment analysis (TRF). This technique is a modified Southern blot, which measures the heterogeneous range of telomere lengths in a cell population using the length distribution of the terminal restriction fragments (Harley et al. , 1990; Ouellette et al. , 2000). This method can be used in eukaryotic cells. The description below focuses on the measurement of human cancer cells telomere length. The principle of this method relies on the lack of

  8. Intermittency in 197Au fragmentation

    International Nuclear Information System (INIS)

    Dabrowska, A.; Holynski, R.; Olszewski, A.; Szarska, M.; Wilczynska, B.; Wolter, W.; Wosiek, B.; Cherry, M.L.; Deines-Jones, P.; Jones, W.V.; Sengupta, K.; Wefel, B.

    1995-07-01

    The concept of factorial moments was applied to an analysis of the dynamical fluctuations in the charge distributions of the fragments emitted from gold nuclei with energies 10.6 and < 1.0 GeV/n interacting with emulsion nuclei. Clear evidence for intermittent fluctuations has been found in an analysis using all the particles released from the gold projectile, with a stronger effect observed below 1 GeV/n than at 10.6 GeV/n. For the full data sets, however, the intermittency effect was found to be very sensitive to the singly charged particles, and neglecting these particles strongly reduces the intermittency signal. When the analysis is restricted to the multiply charged fragments, an intermittency effect is revealed only for multifragmentation events, although one that is enhanced as compared to the analysis of all, singly and multiply charged, particles. The properties of the anomalous fractal dimensions suggest a sequential decay mechanism, rather than the existence of possible critical behaviour in the process of nuclear fragmentation. The likely influence of the charge conservation effects and the finite size of decaying systems on the observed intermittency signals was pointed out. (author). 37 refs, 9 figs, 5 tabs

  9. Residual Fragments after Percutaneous Nephrolithotomy

    Directory of Open Access Journals (Sweden)

    Kaan Özdedeli

    2012-09-01

    Full Text Available Clinically insignificant residual fragments (CIRFs are described as asymptomatic, noninfectious and nonobstructive stone fragments (≤4 mm remaining in the urinary system after the last session of any intervention (ESWL, URS or PCNL for urinary stones. Their insignificance is questionable since CIRFs could eventually become significant, as their presence may result in recurrent stone growth and they may cause pain and infection due to urinary obstruction. They may become the source of persistent infections and a significant portion of the patients will have a stone-related event, requiring auxilliary interventions. CT seems to be the ultimate choice of assessment. Although there is no concensus about the timing, recent data suggests that it may be performed one month after the procedure. However, imaging can be done in the immediate postoperative period, if there are no tubes blurring the assessment. There is some evidence indicating that selective medical therapy may have an impact on decreasing stone formation rates. Retrograde intrarenal surgery, with its minimally invasive nature, seems to be the best way to deal with residual fragments.

  10. Fragmentation measurement using image processing

    Directory of Open Access Journals (Sweden)

    Farhang Sereshki

    2016-12-01

    Full Text Available In this research, first of all, the existing problems in fragmentation measurement are reviewed for the sake of its fast and reliable evaluation. Then, the available methods used for evaluation of blast results are mentioned. The produced errors especially in recognizing the rock fragments in computer-aided methods, and also, the importance of determination of their sizes in the image analysis methods are described. After reviewing the previous work done, an algorithm is proposed for the automated determination of rock particles’ boundary in the Matlab software. This method can determinate automatically the particles boundary in the minimum time. The results of proposed method are compared with those of Split Desktop and GoldSize software in two automated and manual states. Comparing the curves extracted from different methods reveals that the proposed approach is accurately applicable in measuring the size distribution of laboratory samples, while the manual determination of boundaries in the conventional software is very time-consuming, and the results of automated netting of fragments are very different with the real value due to the error in separation of the objects.

  11. Geometrical scaling of jet fragmentation photons

    Energy Technology Data Exchange (ETDEWEB)

    Hattori, Koichi, E-mail: koichi.hattori@riken.jp [RIKEN BNL Research Center, Brookhaven National Laboratory, Upton NY 11973 (United States); Theoretical Research Division, Nishina Center, RIKEN, Wako, Saitama 351-0198 (Japan); McLerran, Larry, E-mail: mclerran@bnl.gov [RIKEN BNL Research Center, Brookhaven National Laboratory, Upton NY 11973 (United States); Physics Dept., Bdg. 510A, Brookhaven National Laboratory, Upton, NY-11973 (United States); Physics Dept., China Central Normal University, Wuhan (China); Schenke, Björn, E-mail: bschenke@bnl.gov [Physics Dept., Bdg. 510A, Brookhaven National Laboratory, Upton, NY-11973 (United States)

    2016-12-15

    We discuss jet fragmentation photons in ultrarelativistic heavy-ion collisions. We argue that, if the jet distribution satisfies geometrical scaling and an anisotropic spectrum, these properties are transferred to photons during the jet fragmentation.

  12. Evolution equations for extended dihadron fragmentation functions

    International Nuclear Information System (INIS)

    Ceccopieri, F.A.; Bacchetta, A.

    2007-03-01

    We consider dihadron fragmentation functions, describing the fragmentation of a parton in two unpolarized hadrons, and in particular extended dihadron fragmentation functions, explicitly dependent on the invariant mass, M h , of the hadron pair. We first rederive the known results on M h -integrated functions using Jet Calculus techniques, and then we present the evolution equations for extended dihadron fragmentation functions. Our results are relevant for the analysis of experimental measurements of two-particle-inclusive processes at different energies. (orig.)

  13. Polarization and alignment of nucleus fission fragments

    International Nuclear Information System (INIS)

    Barabanov, A.L.; Grechukhin, D.P.

    1987-01-01

    Correlation of fragment orientation with orientation axis of fissile nucleus and with n-vector f vector of fragment divergence is considered. Estimations of polarization and alignment of fission fragments of preliminarily oriented nuclei in correlation (with n-vector f recording) and integral (with n-vector f averaging) experiments were conducted. It is shown that high sensitivity of polarization and fragment alignment to the character of nucleus movement at the stage of descent from barrier to rupture point exists

  14. Advanced Heart Failure

    Science.gov (United States)

    ... Artery Disease Venous Thromboembolism Aortic Aneurysm More Advanced Heart Failure Updated:May 9,2017 When heart failure (HF) ... Making This content was last reviewed May 2017. Heart Failure • Home • About Heart Failure • Causes and Risks for ...

  15. Photon-hadron fragmentation: theoretical situation

    International Nuclear Information System (INIS)

    Peschanski, R.

    1983-07-01

    Using a selection of new experimental results models of hadronic fragmentation and their phenomenological comparison are presented. Indeed a convenient theory of hadronic fragmentation -for instance based on Q.C.D.- does not exist: low transverse momentum fragmentation involves the badly known hadronic long-range forces. Models should clarify the situation in the prospect of an eventual future theory

  16. Scaling and critical behaviour in nuclear fragmentation

    International Nuclear Information System (INIS)

    Campi, X.

    1990-09-01

    These notes review recent results on nuclear fragmentation. An analysis of experimental data from exclusive experiments is made in the framework of modern theories of fragmentation of finite size objects. We discuss the existence of a critical regime of fragmentation and the relevance of scaling and finite size scaling

  17. Remarks about the hypothesis of limiting fragmentation

    International Nuclear Information System (INIS)

    Chou, T.T.; Yang, C.N.

    1987-01-01

    Remarks are made about the hypothesis of limiting fragmentation. In particular, the concept of favored and disfavored fragment distribution is introduced. Also, a sum rule is proved leading to a useful quantity called energy-fragmentation fraction. (author). 11 refs, 1 fig., 2 tabs

  18. Quark fragmentation in e+e- collisions

    International Nuclear Information System (INIS)

    Oddone, P.

    1984-12-01

    This brief review of new results in quark and gluon fragmentation observed in e + e - collisions concentrates mostly on PEP results and, within PEP, mostly on TPC results. The new PETRA results have been reported at this conference by M. Davier. It is restricted to results on light quark fragmentation since the results on heavy quark fragmentation have been reported by J. Chapman

  19. Self-organized criticality in fragmenting

    DEFF Research Database (Denmark)

    Oddershede, L.; Dimon, P.; Bohr, J.

    1993-01-01

    The measured mass distributions of fragments from 26 fractured objects of gypsum, soap, stearic paraffin, and potato show evidence of obeying scaling laws; this suggests the possibility of self-organized criticality in fragmenting. The probability of finding a fragment scales inversely to a power...

  20. Neighbouring charge fragmentations in low energy fission

    International Nuclear Information System (INIS)

    Montoya, M.

    1986-10-01

    Shell and odd-even effects in fission have been largely studied until now. The structure in fragment mass, charge and kinetic energy distributions of fragments were interpreted as shell and even-odd effects. In this paper, we want to show that the discret change of fragment charge symmetry should produce also structures in those distribution. 19 refs

  1. Immune mediated liver failure

    OpenAIRE

    Wang, Xiaojing; Ning, Qin

    2014-01-01

    Liver failure is a clinical syndrome of various etiologies, manifesting as jaundice, encephalopathy, coagulopathy and circulatory dysfunction, which result in subsequent multiorgan failure. Clinically, liver failure is classified into four categories: acute, subacute, acute-on-chronic and chronic liver failure. Massive hepatocyte death is considered to be the core event in the development of liver failure, which occurs when the extent of hepatocyte death is beyond the liver regenerative capac...

  2. Chronic heart failure

    OpenAIRE

    Hopper, Ingrid; Easton, Kellie

    2017-01-01

    1. The common symptoms and signs of chronic heart failure are dyspnoea, ankle swelling, raised jugular venous pressure and basal crepitations. Other conditions may be confused with chronic heart failure, including dependent oedema or oedema due to renal or hepatic disease. Shortness of breath may be due to respiratory disease or severe anaemia. Heart failure secondary to lung disease (cor pulmonale) should be distinguished from congestive cardiac failure. Heart failure may also present with l...

  3. Fission fragment excited laser system

    Science.gov (United States)

    McArthur, David A.; Tollefsrud, Philip B.

    1976-01-01

    A laser system and method for exciting lasing action in a molecular gas lasing medium which includes cooling the lasing medium to a temperature below about 150 K and injecting fission fragments through the lasing medium so as to preferentially excite low lying vibrational levels of the medium and to cause population inversions therein. The cooled gas lasing medium should have a mass areal density of about 5 .times. 10.sup.-.sup.3 grams/square centimeter, relaxation times of greater than 50 microseconds, and a broad range of excitable vibrational levels which are excitable by molecular collisions.

  4. Fragment emission from modestly excited nuclear systems

    Energy Technology Data Exchange (ETDEWEB)

    Lou, Y. [Indiana Univ., Bloomington, IN (United States). Dept. of Chemistry]|[Indiana Univ., Bloomington, IN (United States). Cyclotron Facility; Souza, R.T. de [Indiana Univ., Bloomington, IN (United States). Dept. of Chemistry]|[Indiana Univ., Bloomington, IN (United States). Cyclotron Facility; Chen, S.L. [Indiana Univ., Bloomington, IN (United States). Dept. of Chemistry]|[Indiana Univ., Bloomington, IN (United States). Cyclotron Facility; Cornell, E.W. [Indiana Univ., Bloomington, IN (United States). Dept. of Chemistry]|[Indiana Univ., Bloomington, IN (United States). Cyclotron Facility; Davin, B. [Indiana Univ., Bloomington, IN (United States). Dept. of Chemistry]|[Indiana Univ., Bloomington, IN (United States). Cyclotron Facility; Fox, D. [Indiana Univ., Bloomington, IN (United States). Dept. of Chemistry]|[Indiana Univ., Bloomington, IN (United States). Cyclotron Facility; Hamilton, T.M. [Indiana Univ., Bloomington, IN (United States). Dept. of Chemistry]|[Indiana Univ., Bloomington, IN (United States). Cyclotron Facility; Mcdonald, K. [Indiana Univ., Bloomington, IN (United States). Dept. of Chemistry]|[Indiana Univ., Bloomington, IN (United States). Cyclotron Facility; Tsang, M.B. [Michigan State Univ., East Lansing, MI (United States). National Superconducting Cyclotron Lab.; Glasmacher, T. [Michigan State Univ., East Lansing, MI (United States). National Superconducting Cyclotron Lab.; Dinius, J. [Michigan State Univ., East Lansing, MI (United States). National Superconducting Cyclotron Lab.; Gelbke, C.K. [Michigan State Univ., East Lansing, MI (United States). National Superconducting Cyclotron Lab.; Handzy, D.O. [Indiana Univ., Bloomington, IN (United States). Dept. of Chemistry]|[Indiana Univ., Bloomington, IN (United States). Cyclotron Facility]|[Michigan State Univ., East Lansing, MI (United States). National Superconducting Cyclotron Lab.; Hsi, W.C.

    1996-07-08

    Fragment emission patterns occurring in nuclear systems of modest excitation are studied. Exclusive measurement of fragment emission in {sup 14}N+{sup 197}Au reactions at E/A=100, 130 and 156 MeV allows selection of central collisions where a single source dominates the decay. Low threshold measurement of IMF emission for these events allows investigation of the influence of detector threshold effects. The time scale of fragment emission is deduced using fragment-fragment velocity correlations. Comparisons are made to the predictions of a statistical decay model. (orig.).

  5. Velocity distribution of fragments of catastrophic impacts

    Science.gov (United States)

    Takagi, Yasuhiko; Kato, Manabu; Mizutani, Hitoshi

    1992-01-01

    Three dimensional velocities of fragments produced by laboratory impact experiments were measured for basalts and pyrophyllites. The velocity distribution of fragments obtained shows that the velocity range of the major fragments is rather narrow, at most within a factor of 3 and that no clear dependence of velocity on the fragment mass is observed. The NonDimensional Impact Stress (NDIS) defined by Mizutani et al. (1990) is found to be an appropriate scaling parameter to describe the overall fragment velocity as well as the antipodal velocity.

  6. Models of fragmentation with composite power laws

    Science.gov (United States)

    Tavassoli, Z.; Rodgers, G. J.

    1999-06-01

    Some models for binary fragmentation are introduced in which a time dependent transition size produces two regions of fragment sizes above and below the transition size. In the first model we assume a fixed rate of fragmentation for the largest fragment and two different rates of fragmentation in the two regions of sizes above and below the transition size. The model is solved exactly in the long time limit to reveal stable time-invariant solutions for the fragment size and mass distributions. These solutions exhibit composite power law behaviours; power laws with two different exponents for fragments in smaller and larger regions. A special case of the model with no fragmentation in the smaller size region is also examined. Another model is also introduced which have three regions of fragment sizes with different rates of fragmentation. The similarities between the stable distributions in our models and composite power law distributions from experimental work on shock fragmentation of long thin glass rods and thick clay plates are discussed.

  7. Extraction of 16th Century Calender Fragments

    DEFF Research Database (Denmark)

    Holck, Jakob Povl; Etheridge, Christian

    at the Cultural Heritage & Archaeometric Research Team, SDU. Upon finding medieval manuscript fragments in the university library’s special collections, scholars at the Centre for Medieval Literature are consulted. In most cases, digital pictures of the finds will circulate in the international community...... fragments may require extensive use of Big Data and other forms of analysis in order to be identified. Usually, the university library prefers not to remove the fragments from their “fragment carriers”. In order to read fragments that are only partially visible or invisible, x-ray technology may be deployed...... of medieval scholars. Thousands of 16th and 17th Century books are stored in the University Library of Southern Denmark. One out of five of these books is expected to contain medieval manuscript fragments or fragments of rare prints, e.g. incunabula....

  8. The formation of planets by disc fragmentation

    Directory of Open Access Journals (Sweden)

    Stamatellos Dimitris

    2013-04-01

    Full Text Available I discuss the role that disc fragmentation plays in the formation of gas giant and terrestrial planets, and how this relates to the formation of brown dwarfs and low-mass stars, and ultimately to the process of star formation. Protostellar discs may fragment, if they are massive enough and can cool fast enough, but most of the objects that form by fragmentation are brown dwarfs. It may be possible that planets also form, if the mass growth of a proto-fragment is stopped (e.g. if this fragment is ejected from the disc, or suppressed and even reversed (e.g by tidal stripping. I will discuss if it is possible to distinguish whether a planet has formed by disc fragmentation or core accretion, and mention of a few examples of observed exoplanets that are suggestive of formation by disc fragmentation.

  9. Reframing landscape fragmentation's effects on ecosystem services.

    Science.gov (United States)

    Mitchell, Matthew G E; Suarez-Castro, Andrés F; Martinez-Harms, Maria; Maron, Martine; McAlpine, Clive; Gaston, Kevin J; Johansen, Kasper; Rhodes, Jonathan R

    2015-04-01

    Landscape structure and fragmentation have important effects on ecosystem services, with a common assumption being that fragmentation reduces service provision. This is based on fragmentation's expected effects on ecosystem service supply, but ignores how fragmentation influences the flow of services to people. Here we develop a new conceptual framework that explicitly considers the links between landscape fragmentation, the supply of services, and the flow of services to people. We argue that fragmentation's effects on ecosystem service flow can be positive or negative, and use our framework to construct testable hypotheses about the effects of fragmentation on final ecosystem service provision. Empirical efforts to apply and test this framework are critical to improving landscape management for multiple ecosystem services. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Structures of endothiapepsin-fragment complexes from crystallographic fragment screening using a novel, diverse and affordable 96-compound fragment library.

    Science.gov (United States)

    Huschmann, Franziska U; Linnik, Janina; Sparta, Karine; Ühlein, Monika; Wang, Xiaojie; Metz, Alexander; Schiebel, Johannes; Heine, Andreas; Klebe, Gerhard; Weiss, Manfred S; Mueller, Uwe

    2016-05-01

    Crystallographic screening of the binding of small organic compounds (termed fragments) to proteins is increasingly important for medicinal chemistry-oriented drug discovery. To enable such experiments in a widespread manner, an affordable 96-compound library has been assembled for fragment screening in both academia and industry. The library is selected from already existing protein-ligand structures and is characterized by a broad ligand diversity, including buffer ingredients, carbohydrates, nucleotides, amino acids, peptide-like fragments and various drug-like organic compounds. When applied to the model protease endothiapepsin in a crystallographic screening experiment, a hit rate of nearly 10% was obtained. In comparison to other fragment libraries and considering that no pre-screening was performed, this hit rate is remarkably high. This demonstrates the general suitability of the selected compounds for an initial fragment-screening campaign. The library composition, experimental considerations and time requirements for a complete crystallographic fragment-screening campaign are discussed as well as the nine fully refined obtained endothiapepsin-fragment structures. While most of the fragments bind close to the catalytic centre of endothiapepsin in poses that have been observed previously, two fragments address new sites on the protein surface. ITC measurements show that the fragments bind to endothiapepsin with millimolar affinity.

  11. Structures of endothiapepsin–fragment complexes from crystallographic fragment screening using a novel, diverse and affordable 96-compound fragment library

    Science.gov (United States)

    Huschmann, Franziska U.; Linnik, Janina; Sparta, Karine; Ühlein, Monika; Wang, Xiaojie; Metz, Alexander; Schiebel, Johannes; Heine, Andreas; Klebe, Gerhard; Weiss, Manfred S.; Mueller, Uwe

    2016-01-01

    Crystallographic screening of the binding of small organic compounds (termed fragments) to proteins is increasingly important for medicinal chemistry-oriented drug discovery. To enable such experiments in a widespread manner, an affordable 96-compound library has been assembled for fragment screening in both academia and industry. The library is selected from already existing protein–ligand structures and is characterized by a broad ligand diversity, including buffer ingredients, carbohydrates, nucleotides, amino acids, peptide-like fragments and various drug-like organic compounds. When applied to the model protease endothiapepsin in a crystallographic screening experiment, a hit rate of nearly 10% was obtained. In comparison to other fragment libraries and considering that no pre-screening was performed, this hit rate is remarkably high. This demonstrates the general suitability of the selected compounds for an initial fragment-screening campaign. The library composition, experimental considerations and time requirements for a complete crystallographic fragment-screening campaign are discussed as well as the nine fully refined obtained endothiapepsin–fragment structures. While most of the fragments bind close to the catalytic centre of endothiapepsin in poses that have been observed previously, two fragments address new sites on the protein surface. ITC measurements show that the fragments bind to endothiapepsin with millimolar affinity. PMID:27139825

  12. Heart failure - surgeries and devices

    Science.gov (United States)

    ... surgery; HF - surgery; Intra-aortic balloon pumps - heart failure; IABP - heart failure; Catheter based assist devices - heart failure ... problem may cause heart failure or make heart failure worse. Heart valve surgery may be needed to repair or ...

  13. Revisiting the Lund Fragmentation Model

    International Nuclear Information System (INIS)

    Andersson, B.; Nilsson, A.

    1992-10-01

    We present a new method to implement the Lund Model fragmentation distributions for multi-gluon situations. The method of Sjoestrand, implemented in the well-known Monte Carlo simulation program JETSET, is robust and direct and according to his findings there are no observable differences between different ways to implement his scheme. His method can be described as a space-time method because the breakup proper time plays a major role. The method described in this paper is built on energy-momentum space methods. We make use of the χ-curve, which is defined directly from the energy momentum vectors of the partons. We have shown that the χ-curve describes the breakup properties and the final state energy momentum distributions in the mean. We present a method to find the variations around the χ-curve, which also implements the basic Lund Model fragmentation distributions (the area-law and the corresponding iterative cascade). We find differences when comparing the corresponding Monte Carlo implementation REVJET to the JETSET distributions inside the gluon jets. (au)

  14. Knowledge-based Fragment Binding Prediction

    Science.gov (United States)

    Tang, Grace W.; Altman, Russ B.

    2014-01-01

    Target-based drug discovery must assess many drug-like compounds for potential activity. Focusing on low-molecular-weight compounds (fragments) can dramatically reduce the chemical search space. However, approaches for determining protein-fragment interactions have limitations. Experimental assays are time-consuming, expensive, and not always applicable. At the same time, computational approaches using physics-based methods have limited accuracy. With increasing high-resolution structural data for protein-ligand complexes, there is now an opportunity for data-driven approaches to fragment binding prediction. We present FragFEATURE, a machine learning approach to predict small molecule fragments preferred by a target protein structure. We first create a knowledge base of protein structural environments annotated with the small molecule substructures they bind. These substructures have low-molecular weight and serve as a proxy for fragments. FragFEATURE then compares the structural environments within a target protein to those in the knowledge base to retrieve statistically preferred fragments. It merges information across diverse ligands with shared substructures to generate predictions. Our results demonstrate FragFEATURE's ability to rediscover fragments corresponding to the ligand bound with 74% precision and 82% recall on average. For many protein targets, it identifies high scoring fragments that are substructures of known inhibitors. FragFEATURE thus predicts fragments that can serve as inputs to fragment-based drug design or serve as refinement criteria for creating target-specific compound libraries for experimental or computational screening. PMID:24762971

  15. In situ fragmentation and rock particle sorting on arid hills

    Science.gov (United States)

    McGrath, Gavan S.; Nie, Zhengyao; Dyskin, Arcady; Byrd, Tia; Jenner, Rowan; Holbeche, Georgina; Hinz, Christoph

    2013-03-01

    Transport processes are often proposed to explain the sorting of rock particles on arid hillslopes, where mean rock particle size often decreases in the downslope direction. Here we show that in situ fragmentation of rock particles can also produce similar patterns. A total of 93,414 rock particles were digitized from 880 photographs of the surface of three mesa hills in the Great Sandy Desert, Australia. Rock particles were characterized by the projected Feret's diameter and circularity. Distance from the duricrust cap was found to be a more robust explanatory variable for diameter than the local hillslope gradient. Mean diameter decreased exponentially downslope, while the fractional area covered by rock particles decreased linearly. Rock particle diameters were distributed lognormally, with both the location and scale parameters decreasing approximately linearly downslope. Rock particle circularity distributions showed little change; only a slight shift in the mode to more circular particles was noted to occur downslope. A dynamic fragmentation model was used to assess whether in situ weathering alone could reproduce the observed downslope fining of diameters. Modeled and observed size distributions agreed well and both displayed a preferential loss of relatively large rock particles and an apparent approach to a terminal size distribution of the rocks downslope. We show this is consistent with a size effect in material strength, where large rocks are more susceptible to fatigue failure under stress than smaller rocks. In situ fragmentation therefore produces qualitatively similar patterns to those that would be expected to arise from selective transport.

  16. 2014 Grady County, GA DMC 4-Band 8 Bit Imagery

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set consists of one-foot pixel resolution, natural color orthoimages covering the urban area footprint. An orthoimage is remotely sensed image data in...

  17. Ray transference of a system with radial gradi- ent index

    Directory of Open Access Journals (Sweden)

    W. F. Harris

    2012-12-01

    Full Text Available The ray transference is central to the understanding of the first-order optical character of an optical system including the visual optical system of the eye.  It can be calculated for dioptric and catadioptric systems from a knowledge of curvatures, tilts and spacing of surfaces in the system provided the material between successive surfaces has a uniform index of refraction.  However the index of the natural lens of the eye is not uniform but varies with position.  There is a need, therefore, for a method of calculating the transference of systems containing such gradient-index elements.  As a first step this paper shows that the transference of elements in which the index varies radially can be obtained directly from published formulae.  The transferences of radial-gradient systems are examined.  Expressions are derived for several properties including the power, the front- and back-surface powers and the locations of the cardinal points.  Equations are obtained for rays through such systems and for the locations of images of object points through them.  Numerical examples are presented in the appen-dix. (S Afr Optom 2012 71(2 57-63

  18. DIGITAL FLOOD INSURANCE RATE MAP DATABASE, GRADY COUNTY, OKLAHOMA

    Data.gov (United States)

    Federal Emergency Management Agency, Department of Homeland Security — The Digital Flood Insurance Rate Map (DFIRM) Database depicts flood risk information and supporting data used to develop the risk data. The primary risk...

  19. Dynamic effects in fragmentation reactions

    International Nuclear Information System (INIS)

    Bertsch, G. F.; Esbensen, H.

    2002-01-01

    Fragmentation reactions offer a useful tool to study the spectroscopy of halo nuclei, but the large extent of the halo wave function makes the reaction theory more difficult. The simple reaction models based on the eikonal approximation for the nuclear interaction or first-order perturbation theory for the Coulomb interaction have systematic errors that they investigate here, comparing to the predictions of complete dynamical calculations. They find that stripping probabilities are underpredicted by the eikonal model, leading to extracted spectroscopy strengths that are two large. In contrast, the Coulomb excitation is overpredicted by the simple theory. They attribute this to a screening effect, as is well known in the Barkas effect on stopping powers. The errors decrease with beam energy as E(sub beam)(sup -1), and are not significant at beam energies above 50 MeV/u. At lower beam energies, the effects should be taken into account when extracting quantitative spectroscopic strengths

  20. Acute liver failure

    DEFF Research Database (Denmark)

    Larsen, Fin Stolze; Bjerring, Peter Nissen

    2011-01-01

    Acute liver failure (ALF) results in a multitude of serious complications that often lead to multi-organ failure. This brief review focuses on the pathophysiological processes in ALF and how to manage these.......Acute liver failure (ALF) results in a multitude of serious complications that often lead to multi-organ failure. This brief review focuses on the pathophysiological processes in ALF and how to manage these....

  1. In Support of Failure

    Science.gov (United States)

    Carr, Allison

    2013-01-01

    In this essay, I propose a concerted effort to begin devising a theory and pedagogy of failure. I review the discourse of failure in Western culture as well as in composition pedagogy, ultimately suggesting that failure is not simply a judgement or indication of rank but is a relational, affect-bearing concept with tremendous relevance to…

  2. Fragmentation and flow in central collisions

    International Nuclear Information System (INIS)

    Jacak, B.V.; Doss, K.G.R.; Gustafsson, H.A.

    1987-01-01

    Investigation of the fragmentation mechanism requires the measurement of complicated observables. To identify what part of the reacting system gives rise to the fragments, it would be useful to tag them as participants or spectators. A large acceptance for all the reaction products and an event-by-event measurement of the fragment multiplicity is required to distinguish fragment formation via sequential emission from a large equilibrated system and multifragmentation. In order to address whether fragments are formed early or late in the collision, information about the dynamical evolution of the reaction is necessary. This can be provided by study of the global properties of the events. This paper discusses experimental techniques applicable to studying fragmentation processes. 25 refs., 8 figs

  3. Gallstone fragmentation by control electrohydraulic lithotripsy

    International Nuclear Information System (INIS)

    Tung, G.A.; Mueller, P.R.; Brink, J.A.; Saini, S.; Picus, D.; Simeone, J.F.; Ferrucci, J.T.

    1989-01-01

    The authors have performed in vitro contact electrohydraulic lithotripsy (EHL) of 100 gallstones > 10 mm in diameter to identify physical and technical factors that affect fragmentation success. Ninety-one of 100 stones were fragmented with a 3-F electrode (average, seven shocks; range, 1--42); only 12 stones were fragmented with a single shock. Of the nine stones refractory to 50 shocks, four were > 30 mm in diameter and five stones were densely calcified. The most important variable determining power requirements for fragmentation was gallstone size (R = .58), but radiographic calcification of gallstones was also important (R = .47). Stones < 15 mm tended to produce fragments of left-angle 2 mm; stones right-angle 20 mm tended to produce two to five large discrete fragments (P , .05). In addition, lithotripsy could be conducted equally well in 1:1 dilute diatrizoate contrast agent as in 1:6 normal saline, suggesting that contact EHL could be performed under fluoroscopy

  4. Complex fragment emission from hot compound nuclei

    International Nuclear Information System (INIS)

    Moretto, L.G.

    1986-03-01

    The experimental evidence for compound nucleus emission of complex fragments at low energies is used to interpret the emission of the same fragments at higher energies. The resulting experimental picture is that of highly excited compound nuclei formed in incomplete fusion processes which decay statistically. In particular, complex fragments appear to be produced mostly through compound nucleus decay. In the appendix a geometric-kinematic theory for incomplete fusion and the associated momentum transfer is outlined. 10 refs., 19 figs

  5. Fragment Size Distribution of Blasted Rock Mass

    Science.gov (United States)

    Jug, Jasmin; Strelec, Stjepan; Gazdek, Mario; Kavur, Boris

    2017-12-01

    Rock mass is a heterogeneous material, and the heterogeneity of rock causes sizes distribution of fragmented rocks in blasting. Prediction of blasted rock mass fragmentation has a significant role in the overall economics of opencast mines. Blasting as primary fragmentation can significantly decrease the cost of loading, transport, crushing and milling operations. Blast fragmentation chiefly depends on the specific blast design (geometry of blast holes drilling, the quantity and class of explosive, the blasting form, the timing and partition, etc.) and on the properties of the rock mass (including the uniaxial compressive strength, the rock mass elastic Young modulus, the rock discontinuity characteristics and the rock density). Prediction and processing of blasting results researchers can accomplish by a variety of existing software’s and models, one of them is the Kuz-Ram model, which is possibly the most widely used approach to estimating fragmentation from blasting. This paper shows the estimation of fragmentation using the "SB" program, which was created by the authors. Mentioned program includes the Kuz-Ram model. Models of fragmentation are confirmed and calibrated by comparing the estimated fragmentation with actual post-blast fragmentation from image processing techniques. In this study, the Kuz-Ram fragmentation model has been used for an open-pit limestone quarry in Dalmatia, southern Croatia. The resulting calibrated value of the rock factor enables the quality prognosis of fragmentation in further blasting works, with changed drilling geometry and blast design parameters. It also facilitates simulation in the program to optimize blasting works and get the desired fragmentations of the blasted rock mass.

  6. Fragmentation of neck-like structures

    International Nuclear Information System (INIS)

    Montoya, C.; Bowman, D.R.; Peaslee, G.F.; Michigan State Univ., East Lansing, MI

    1994-01-01

    Evidence for intermediate mass fragment emission from neck-like structures joining projectile- and target-like residues has been observed for peripheral 129 Xe+ nat Cu collisions at E/A=50 MeV. These framents are emitted primarily at velocities intermediate between those of the projectile and the target. Relative to the charge distribution for fragments evaporated from the projectile-like residue, the distribution for ''neck'' emission shows an enhanced emission for fragments with 4 f < 8. (orig.)

  7. Plasma copeptin levels and prediction of outcome in heart failure outpatients

    DEFF Research Database (Denmark)

    Balling, Louise; Kistorp, Caroline; Schou, Morten

    2012-01-01

    Copeptin, a stable fragment of the vasopressin prohormone, has been shown to be a significant biomarker for morbidity and mortality in heart failure. The aims of this study were to evaluate the influence of plasma sodium on the prognostic significance of copeptin concentrations in heart failure o...

  8. Fragmentation of sperm DNA using the TUNEL method.

    Science.gov (United States)

    Chenlo, P H; Curi, S M; Pugliese, M N; Ariagno, J I; Sardi-Segovia, M; Furlan, M J; Repetto, H E; Zeitler, E; Cohen, M; Mendeluk, G R

    2014-11-01

    To establish the validity of the TUNEL assay in determining sperm DNA fragmentation, the relationship between the degree of fragmentation and the seminal parameters and the sample needed to conduct the test. We used semen samples from healthy fertile men (n=33), patients who consulted for infertility with a prescription for the TUNEL assay (n=77) and patients with intracytoplasmic sperm injection failure (n=20), analyzed according to the 2010 WHO. The TUNEL/propidium iodide test was performed by flow cytometry, on baseline and post-swim-up samples. The cutoff value for the TUNEL assay (ROC curves) was 26%, with a sensitivity and specificity of 85% and 89%, respectively. The pre-swim-up and post-swim-up medians of the results from the TUNEL assay showed no significant differences (17.0% vs. 12.9%, respectively). However, 39.1% of the samples showed a difference greater than 15 in absolute value between the results of the baseline and post-swim-up TUNEL assays. The linear correlation study of the morphology, mobility and vitality using the post-swim-up TUNEL assay showed a greater correlation than preselection, with significant results (r: -0.394, P<.0001; r: -0.461, P<.0001; r: -0.526, P<.0001). The TUNEL assay is a valid test for clinical use. DNA fragmentation is a factor independent from traditional semen tests. We found a greater susceptibility to damage generated in the laboratory procedures in the samples with lower quality. The sample of choice for evaluating DNA fragmentation will depend on whether the clinician is treating a natural or assisted fertilization. Copyright © 2014 AEU. Published by Elsevier Espana. All rights reserved.

  9. Fragment-based approaches to TB drugs.

    Science.gov (United States)

    Marchetti, Chiara; Chan, Daniel S H; Coyne, Anthony G; Abell, Chris

    2018-02-01

    Tuberculosis is an infectious disease associated with significant mortality and morbidity worldwide, particularly in developing countries. The rise of antibiotic resistance in Mycobacterium tuberculosis (Mtb) urgently demands the development of new drug leads to tackle resistant strains. Fragment-based methods have recently emerged at the forefront of pharmaceutical development as a means to generate more effective lead structures, via the identification of fragment molecules that form weak but high quality interactions with the target biomolecule and subsequent fragment optimization. This review highlights a number of novel inhibitors of Mtb targets that have been developed through fragment-based approaches in recent years.

  10. Gluon fragmentation in T(1S) decays

    International Nuclear Information System (INIS)

    Bienlein, J.K.

    1983-05-01

    In T(1S) decays most observables (sphericity, charged multiplicity, photonic energy fraction, inclusive spectra) can be understood assuming that gluons fragment like quarks. New results from LENA use the (axis-independent) Fox-Wolfram moments for the photonic energy deposition. Continuum reactions show 'standard' Field-Feynman fragmentation. T(1S) decays show a significant difference in the photonic energy topology. It is more isotropic than with the Field-Feynman fragmentation scheme. Gluon fragmentation into isoscalar mesons (a la Peterson and Walsh) is excluded. But if one forces the leading particle to be isoscalar, one gets good agreement with the data. (orig.)

  11. Measuring the temperature of hot nuclear fragments

    International Nuclear Information System (INIS)

    Wuenschel, S.; Bonasera, A.; May, L.W.; Souliotis, G.A.; Tripathi, R.; Galanopoulos, S.; Kohley, Z.; Hagel, K.; Shetty, D.V.; Huseman, K.; Soisson, S.N.; Stein, B.C.; Yennello, S.J.

    2010-01-01

    A new thermometer based on fragment momentum fluctuations is presented. This thermometer exhibited residual contamination from the collective motion of the fragments along the beam axis. For this reason, the transverse direction has been explored. Additionally, a mass dependence was observed for this thermometer. This mass dependence may be the result of the Fermi momentum of nucleons or the different properties of the fragments (binding energy, spin, etc.) which might be more sensitive to different densities and temperatures of the exploding fragments. We expect some of these aspects to be smaller for protons (and/or neutrons); consequently, the proton transverse momentum fluctuations were used to investigate the temperature dependence of the source.

  12. Kinetics of fragmentation-annihilation processes

    OpenAIRE

    Filipe, JAN; Rodgers, GJ

    1996-01-01

    We investigate the kinetics of systems in which particles of one species undergo binary fragmentation and pair annihilation. In the latter, nonlinear process, fragments react at collision to produce an inert species, causing loss of mass. We analyze these systems in the reaction-limited regime by solving a continuous model within the mean-field approximation. The rate of fragmentation for a particle of mass x to break into fragments of masses y and x-y has the form x(lambda-1) (lambda > 0), a...

  13. The failure of earthquake failure models

    Science.gov (United States)

    Gomberg, J.

    2001-01-01

    In this study I show that simple heuristic models and numerical calculations suggest that an entire class of commonly invoked models of earthquake failure processes cannot explain triggering of seismicity by transient or "dynamic" stress changes, such as stress changes associated with passing seismic waves. The models of this class have the common feature that the physical property characterizing failure increases at an accelerating rate when a fault is loaded (stressed) at a constant rate. Examples include models that invoke rate state friction or subcritical crack growth, in which the properties characterizing failure are slip or crack length, respectively. Failure occurs when the rate at which these grow accelerates to values exceeding some critical threshold. These accelerating failure models do not predict the finite durations of dynamically triggered earthquake sequences (e.g., at aftershock or remote distances). Some of the failure models belonging to this class have been used to explain static stress triggering of aftershocks. This may imply that the physical processes underlying dynamic triggering differs or that currently applied models of static triggering require modification. If the former is the case, we might appeal to physical mechanisms relying on oscillatory deformations such as compaction of saturated fault gouge leading to pore pressure increase, or cyclic fatigue. However, if dynamic and static triggering mechanisms differ, one still needs to ask why static triggering models that neglect these dynamic mechanisms appear to explain many observations. If the static and dynamic triggering mechanisms are the same, perhaps assumptions about accelerating failure and/or that triggering advances the failure times of a population of inevitable earthquakes are incorrect.

  14. Mechanisms Affecting Population Density in Fragmented Habitat

    Directory of Open Access Journals (Sweden)

    Lutz Tischendorf

    2005-06-01

    Full Text Available We conducted a factorial simulation experiment to analyze the relative importance of movement pattern, boundary-crossing probability, and mortality in habitat and matrix on population density, and its dependency on habitat fragmentation, as well as inter-patch distance. We also examined how the initial response of a species to a fragmentation event may affect our observations of population density in post-fragmentation experiments. We found that the boundary-crossing probability from habitat to matrix, which partly determines the emigration rate, is the most important determinant for population density within habitat patches. The probability of crossing a boundary from matrix to habitat had a weaker, but positive, effect on population density. Movement behavior in habitat had a stronger effect on population density than movement behavior in matrix. Habitat fragmentation and inter-patch distance may have a positive or negative effect on population density. The direction of both effects depends on two factors. First, when the boundary-crossing probability from habitat to matrix is high, population density may decline with increasing habitat fragmentation. Conversely, for species with a high matrix-to-habitat boundary-crossing probability, population density may increase with increasing habitat fragmentation. Second, the initial distribution of individuals across the landscape: we found that habitat fragmentation and inter-patch distance were positively correlated with population density when individuals were distributed across matrix and habitat at the beginning of our simulation experiments. The direction of these relationships changed to negative when individuals were initially distributed across habitat only. Our findings imply that the speed of the initial response of organisms to habitat fragmentation events may determine the direction of observed relationships between habitat fragmentation and population density. The time scale of post-fragmentation

  15. Carboxyl-terminal parathyroid hormone fragments: role in parathyroid hormone physiopathology.

    Science.gov (United States)

    D'Amour, Pierre; Brossard, Jean-Hugues

    2005-07-01

    Carboxyl-terminal parathyroid hormone (C-PTH) fragments constitute 80% of circulating PTH. Since the first 34 amino acids of the PTH structure are sufficient to explain PTH classical biological effects on the type I PTH/PTHrP receptor and since C-PTH fragments do not bind to this receptor, they have long been considered inactive. Recent data suggest the existence of a C-PTH receptor through which C-PTH fragments exert biological effects opposite to those of human PTH(1-84) on the type I PTH/PTHrP receptor. This is why a lot of attention has been paid to these fragments recently. In vivo, synthetic C-PTH fragments are able to decrease calcium concentration, to antagonize the calcemic response to human PTH(1-34) and human PTH(1-84) and to decrease the high bone turnover rate induced by human PTH(1-84). In vitro, they inhibit bone resorption, promote osteocyte apoptosis and exert a variety of effects on bone and cartilaginous cells. These effects are opposite to those of human PTH(1-84) on the PTH/PTHrP type I receptor. This suggests that the molecular forms of circulating PTH may control bone participation in calcium homeostasis via two different receptors. Clinically, the accumulation of C-PTH fragments in renal failure patients may cause PTH resistance and may be associated with adynamic bone disease. Rare parathyroid tumors, without a set point error, overproduce C-PTH fragments. The implication of C-PTH fragments in osteoporosis is still to be explored. C-PTH fragments represent a new field of investigation in PTH biology. More studies are necessary to disclose their real importance in calcium and bone homeostasis in health and disease.

  16. Analysis and performance assessment of a fragment retransmission scheme for energy efficient IEEE 802.11 WLANs.

    Science.gov (United States)

    Mafole, Prosper; Aritsugi, Masayoshi

    2016-01-01

    Backoff-free fragment retransmission (BFFR) scheme enhances the performance of legacy MAC layer fragmentation by eliminating contention overhead. The eliminated overhead is the result of backoff executed before a retransmission attempt is made when fragment transmission failure occurs within a fragment burst. This paper provides a mathematical analysis of BFFR energy efficiency and further assesses, by means of simulations, the energy efficiency, throughput and delay obtained when BFFR is used. The validity of the new scheme is evaluated in different scenarios namely, constant bit rate traffic, realistic bursty internet traffic, node mobility, rigid and elastic flows and their combinations at different traffic loads. We also evaluate and discuss the impact of BFFR on MAC fairness when the number of nodes is varied from 4 to 10. It is shown that BFFR has advantages over legacy MAC fragmentation scheme in all the scenarios.

  17. Parton fragmentation and string dynamics

    International Nuclear Information System (INIS)

    Andersson, B.; Gustafson, G.; Ingelman, G.; Sjoestrand, T.

    1983-01-01

    While much has been learned recently about quark and gluon interactions in the framework of perturbative Quantum Chromodynamics, the relation between calculated parton properties and observed hadron densities involves models where dynamics and jet empirical rules have to be combined. The purpose of this article is to describe a presently successful approach which is based on a cascade jet model using String dynamics. It can readily lead to Monte Carlo jet programmes of great use when analyzing data. Production processes in an iterative cascade approach, with tunneling in a constant force field, are reviewed. Expected differences between quark and gluon jets are discussed. Low transverse momentum phenomena are also reviewed with emphasis on hyperon polarization. In so far as this approach uses a fragmentation scheme based on String dynamics, it was deemed appropriate to also include under the same cover a special report on the Classical theory of relativistic Strings, seen as the classical limit of the Dual Resonance model. The Equations of motion and interaction among strings are presented. (orig.)

  18. Mini-Fragment Fixation Is Equivalent to Bicortical Screw Fixation for Horizontal Medial Malleolus Fractures.

    Science.gov (United States)

    Wegner, Adam M; Wolinsky, Philip R; Robbins, Michael A; Garcia, Tanya C; Amanatullah, Derek F

    2018-05-01

    Horizontal fractures of the medial malleolus occur through application of valgus or abduction force through the ankle that creates a tension failure of the medial malleolus. The authors hypothesize that mini-fragment T-plates may offer improved fixation, but the optimal fixation construct for these fractures remains unclear. Forty synthetic distal tibiae with identical osteotomies were randomized into 4 fixation constructs: (1) two parallel unicortical cancellous screws; (2) two parallel bicortical cortical screws; (3) a contoured mini-fragment T-plate with 2 unicortical screws in the fragment and 2 bicortical screws in the shaft; and (4) a contoured mini-fragment T-plate with 2 bicortical screws in the fragment and 2 unicortical screws in the shaft. Specimens were subjected to offset axial tension loading on a servohydraulic testing system and tracked using high-resolution video. Failure was defined as 2 mm of articular displacement. Analysis of variance followed by a Tukey-Kramer post hoc test was used to assess for differences between groups, with significance defined as Pfragment T-plate constructs (239±83 N/mm and 190±37 N/mm) and the bicortical screw construct (240±17 N/mm) were not statistically different. The mean stiffness values of both mini-fragment T-plate constructs and the bicortical screw construct were higher than that of a parallel unicortical screw construct (102±20 N/mm). Contoured T-plate constructs provide stiffer initial fixation than a unicortical cancellous screw construct. The T-plate is biomechanically equivalent to a bicortical screw construct, but may be superior in capturing small fragments of bone. [Orthopedics. 2018; 41(3):e395-e399.]. Copyright 2018, SLACK Incorporated.

  19. Baculovirus display of functional antibody Fab fragments.

    Science.gov (United States)

    Takada, Shinya; Ogawa, Takafumi; Matsui, Kazusa; Suzuki, Tasuku; Katsuda, Tomohisa; Yamaji, Hideki

    2015-08-01

    The generation of a recombinant baculovirus that displays antibody Fab fragments on the surface was investigated. A recombinant baculovirus was engineered so that the heavy chain (Hc; Fd fragment) of a mouse Fab fragment was expressed as a fusion to the N-terminus of baculovirus gp64, while the light chain of the Fab fragment was simultaneously expressed as a secretory protein. Following infection of Sf9 insect cells with the recombinant baculovirus, the culture supernatant was analyzed by enzyme-linked immunosorbent assay using antigen-coated microplates and either an anti-mouse IgG or an anti-gp64 antibody. A relatively strong signal was obtained in each case, showing antigen-binding activity in the culture supernatant. In western blot analysis of the culture supernatant using the anti-gp64 antibody, specific protein bands were detected at an electrophoretic mobility that coincided with the molecular weight of the Hc-gp64 fusion protein as well as that of gp64. Flow cytometry using a fluorescein isothiocyanate-conjugated antibody specific to mouse IgG successfully detected the Fab fragments on the surface of the Sf9 cells. These results suggest that immunologically functional antibody Fab fragments can be displayed on the surface of baculovirus particles, and that a fluorescence-activated cell sorter with a fluorescence-labeled antigen can isolate baculoviruses displaying specific Fab fragments. This successful baculovirus display of antibody Fab fragments may offer a novel approach for the efficient selection of specific antibodies.

  20. Fragmentation of eastern United States forest types

    Science.gov (United States)

    Kurt H. Riitters; John W. Coulston

    2013-01-01

    Fragmentation is a continuing threat to the sustainability of forests in the Eastern United States, where land use changes supporting a growing human population are the primary driver of forest fragmentation (Stein and others 2009). While once mostly forested, approximately 40 percent of the original forest area has been converted to other land uses, and most of the...

  1. Thermodynamics of the fuel fragmentation gas

    International Nuclear Information System (INIS)

    Perez, R.B.; Alsmiller, R.G. Jr.

    1977-01-01

    In the context of nuclear reactor safety studies, a program is in progress at ORNL whereby fuel-fragmentation situations are mocked up by the application of high-current capacitor discharges through solid UO 2 samples. The goal of the present work is to predict such quantities as the number of gas and liquid fragments and their energy distributions. The point of view adopted is that upon fragmentation, a cloud of UO 2 vapor is formed containing ''primeval'' liquid fragments which act as condensation centers. In the evolution of time, fragment growth is controlled by nucleation, coagulation and evaporation processes. Eventually, the vapor-droplet system will reach a situation in which clusters (fragments) of various sizes and UO 2 vapor will coexist in an ''association-disassociation'' equilibrium. Thus, the physical model considered here consists of the identification of the fragmentation gas with an ''imperfect'' vapor, made up of interacting UO 2 vapor and liquid fragments. The results of the study are presented

  2. Momentum sum rules for fragmentation functions

    International Nuclear Information System (INIS)

    Meissner, S.; Metz, A.; Pitonyak, D.

    2010-01-01

    Momentum sum rules for fragmentation functions are considered. In particular, we give a general proof of the Schaefer-Teryaev sum rule for the transverse momentum dependent Collins function. We also argue that corresponding sum rules for related fragmentation functions do not exist. Our model-independent analysis is supplemented by calculations in a simple field-theoretical model.

  3. A note on convex renorming and fragmentability

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    Abstract. Using the game approach to fragmentability, we give new and simpler proofs of the following known results: (a) If the Banach space admits an equivalent. Kadec norm, then its weak topology is fragmented by a metric which is stronger than the norm topology. (b) If the Banach space admits an equivalent rotund ...

  4. Temperatures of fragment kinetic energy spectra

    International Nuclear Information System (INIS)

    Bauer, W.

    1995-01-01

    Multifragmentation reactions without large compression in the initial state (proton-induced reactions, reverse kinematics, projectile fragmentation) are examined, and it is verified quantitatively that the high temperatures obtained from fragment kinetic energy spectra and lower temperatures obtained from observables such as level population or isotope ratios can be understood in a common framework

  5. Pollen and gene flow in fragmented habitats

    NARCIS (Netherlands)

    Kwak, Manja M.; Velterop, Odilia; van Andel, Jelte

    . Habitat fragmentation affects both plants and pollinators. Habitat fragmentation leads to changes in species richness, population number and size, density, and shape, thus to changes in the spatial arrangement of flowers. These changes influence the amount of food for flower-visiting insects and

  6. Long-term effects of fragmentation and fragment properties on bird species richness in Hawaiian forests

    Science.gov (United States)

    David J. Flaspohler; Christian P. Giardina; Gregory P. Asner; Patrick Hart; Jonathan Price; Cassie Ka’apu Lyons; Xeronimo. Castaneda

    2010-01-01

    Forest fragmentation is a common disturbance affecting biological diversity, yet the impacts of fragmentation on many forest processes remain poorly understood. Forest restoration is likely to be more successful when it proceeds with an understanding of how native and exotic vertebrates utilize forest patches of different size. We used a system of forest fragments...

  7. Managing Feelings about Heart Failure

    Science.gov (United States)

    ... About Heart Failure Module 6: Managing Feelings About Heart Failure Download Module Order Hardcopy Heart failure can cause ... professional help for emotional problems. Common Feelings About Heart Failure It is common for people to feel depressed ...

  8. The politics of municipal fragmentation in Ghana

    Directory of Open Access Journals (Sweden)

    Abdulai Kuyini Mohammed

    2015-06-01

    Full Text Available The scholarly debate over the rival merits of local government consolidation and fragmentation is an old but enduring one. However, in this debate very little attention has been focused on the political dimension of council amalgamation and fragmentation – yet political considerations play a central role in both the formulation and outcomes of de-concentration policy. The purpose of this article is to fill a gap in the literature by examining local government fragmentation in Ghana from 1988 to 2014. The article does this by identifying the key players and analysing their interests and gains, as well as the tensions arising from the fragmentation exercise. The implications from the Ghanaian case for more general theories of fragmentation are drawn out.

  9. Graph Theory. 1. Fragmentation of Structural Graphs

    Directory of Open Access Journals (Sweden)

    Lorentz JÄNTSCHI

    2002-12-01

    Full Text Available The investigation of structural graphs has many fields of applications in engineering, especially in applied sciences like as applied chemistry and physics, computer sciences and automation, electronics and telecommunication. The main subject of the paper is to express fragmentation criteria in graph using a new method of investigation: terminal paths. Using terminal paths are defined most of the fragmentation criteria that are in use in molecular topology, but the fields of applications are more generally than that, as I mentioned before. Graphical examples of fragmentation are given for every fragmentation criteria. Note that all fragmentation is made with a computer program that implements a routine for every criterion.[1] A web routine for tracing all terminal paths in graph can be found at the address: http://vl.academicdirect.ro/molecular_topology/tpaths/ [1] M. V. Diudea, I. Gutman, L. Jäntschi, Molecular Topology, Nova Science, Commack, New York, 2001, 2002.

  10. Automated multiple failure FMEA

    International Nuclear Information System (INIS)

    Price, C.J.; Taylor, N.S.

    2002-01-01

    Failure mode and effects analysis (FMEA) is typically performed by a team of engineers working together. In general, they will only consider single point failures in a system. Consideration of all possible combinations of failures is impractical for all but the simplest example systems. Even if the task of producing the FMEA report for the full multiple failure scenario were automated, it would still be impractical for the engineers to read, understand and act on all of the results. This paper shows how approximate failure rates for components can be used to select the most likely combinations of failures for automated investigation using simulation. The important information can be automatically identified from the resulting report, making it practical for engineers to study and act on the results. The strategy described in the paper has been applied to a range of electrical subsystems, and the results have confirmed that the strategy described here works well for realistically complex systems

  11. Heart Failure in Women

    Science.gov (United States)

    Bozkurt, Biykem; Khalaf, Shaden

    2017-01-01

    Heart failure is an important cause of morbidity and mortality in women, and they tend to develop it at an older age compared to men. Heart failure with preserved ejection fraction is more common in women than in men and accounts for at least half the cases of heart failure in women. When comparing men and women who have heart failure and a low left ventricular ejection fraction, the women are more symptomatic and have a similarly poor outcome. Overall recommendations for guideline-directed medical therapies show no differences in treatment approaches between men and women. Overall, women are generally underrepresented in clinical trials for heart failure. Further studies are needed to shed light into different mechanisms, causes, and targeted therapies of heart failure in women. PMID:29744014

  12. Definition of containment failure

    International Nuclear Information System (INIS)

    Cybulskis, P.

    1982-01-01

    Core meltdown accidents of the types considered in probabilistic risk assessments (PRA's) have been predicted to lead to pressures that will challenge the integrity of containment structures. Review of a number of PRA's indicates considerable variation in the predicted probability of containment failure as a function of pressure. Since the results of PRA's are sensitive to the prediction of the occurrence and the timing of containment failure, better understanding of realistic containment capabilities and a more consistent approach to the definition of containment failure pressures are required. Additionally, since the size and location of the failure can also significantly influence the prediction of reactor accident risk, further understanding of likely failure modes is required. The thresholds and modes of containment failure may not be independent

  13. The size distributions of fragments ejected at a given velocity from impact craters

    Science.gov (United States)

    O'Keefe, John D.; Ahrens, Thomas J.

    1987-01-01

    The mass distribution of fragments that are ejected at a given velocity for impact craters is modeled to allow extrapolation of laboratory, field, and numerical results to large scale planetary events. The model is semi-empirical in nature and is derived from: (1) numerical calculations of cratering and the resultant mass versus ejection velocity, (2) observed ejecta blanket particle size distributions, (3) an empirical relationship between maximum ejecta fragment size and crater diameter, (4) measurements and theory of maximum ejecta size versus ejecta velocity, and (5) an assumption on the functional form for the distribution of fragments ejected at a given velocity. This model implies that for planetary impacts into competent rock, the distribution of fragments ejected at a given velocity is broad, e.g., 68 percent of the mass of the ejecta at a given velocity contains fragments having a mass less than 0.1 times a mass of the largest fragment moving at that velocity. The broad distribution suggests that in impact processes, additional comminution of ejecta occurs after the upward initial shock has passed in the process of the ejecta velocity vector rotating from an initially downward orientation. This additional comminution produces the broader size distribution in impact ejecta as compared to that obtained in simple brittle failure experiments.

  14. On the effect of grain burnback on STS-SRM fragment velocity

    International Nuclear Information System (INIS)

    Eck, M.B.; Mukunda, M.

    1991-01-01

    Concerns raised during the Ulysses Final Safety Analysis Review (FSAR) process called the solid rocket motor (SRM) fragment velocity prediction model into question. The specific area of concern was that there was a section of the SRM casing which was exposed to SRM chamber pressure as the grain (fuel) was consumed. These questions centered on the velocity of fragments which originated from the field joint region given that failure occurred between 37 and 72 seconds mission elapsed time (MET). Two dimensional coupled Eulerian-Lagrangian calculations were performed to assess the hot gas flow field which resulted from SRM casing fragmentation. The fragment to gas interface-pressure time-history obtained from these analyses was reduced to a boundary condition algorithm which was applied to an explicit-time-integration, finite element, three dimensional shell model of the SRM casing and unburned fuel. The results of these calculations showed that the velocity of fragments originating in the field joint was adequately described by the range of velocities given in the Shuttle Data Book (1988). Based on these results, no further analyses were required, and approval was obtained from the Launch Abort Subpanel of the Interagency Nuclear Safety Review Panel to use the SRM fragment velocity environments presented in the Ulysses FSAR (1990)

  15. Exact Solutions of Fragmentation Equations with General Fragmentation Rates and Separable Particles Distribution Kernels

    Directory of Open Access Journals (Sweden)

    S. C. Oukouomi Noutchie

    2014-01-01

    Full Text Available We make use of Laplace transform techniques and the method of characteristics to solve fragmentation equations explicitly. Our result is a breakthrough in the analysis of pure fragmentation equations as this is the first instance where an exact solution is provided for the fragmentation evolution equation with general fragmentation rates. This paper is the key for resolving most of the open problems in fragmentation theory including “shattering” and the sudden appearance of infinitely many particles in some systems with initial finite particles number.

  16. Missing Fragments: Detecting Cooperative Binding in Fragment-Based Drug Design

    Science.gov (United States)

    2012-01-01

    The aim of fragment-based drug design (FBDD) is to identify molecular fragments that bind to alternate subsites within a given binding pocket leading to cooperative binding when linked. In this study, the binding of fragments to human phenylethanolamine N-methyltransferase is used to illustrate how (a) current protocols may fail to detect fragments that bind cooperatively, (b) theoretical approaches can be used to validate potential hits, and (c) apparent false positives obtained when screening against cocktails of fragments may in fact indicate promising leads. PMID:24900472

  17. Dual Fragment Impact of PBX Charges

    Science.gov (United States)

    Haskins, Peter; Briggs, Richard; Leeming, David; White, Nathan; Cheese, Philip; DE&S MoD UK Team; Ordnance Test Solutions Ltd Team

    2017-06-01

    Fragment impact can pose a significant hazard to many systems containing explosives or propellants. Testing for this threat is most commonly carried out using a single fragment. However, it can be argued that an initial fragment strike (or strikes) could sensitise the energetic material to subsequent impacts, which may then lead to a more violent reaction than would have been predicted based upon single fragment studies. To explore this potential hazard we have developed the capability to launch 2 fragments from the same gun at a range of velocities, and achieve impacts on an acceptor charge with good control over the spatial and temporal separation of the strikes. In this paper we will describe in detail the experimental techniques we have used, both to achieve the dual fragment launch and observe the acceptor charge response. In addition, we will describe the results obtained against PBX filled explosive targets; discuss the mechanisms controlling the target response and their significance for vulnerability assessment. Results of these tests have clearly indicated the potential for detonation upon the second strike, at velocities well below those needed for shock initiation by a single fragment.

  18. Introduction to fragment-based drug discovery.

    Science.gov (United States)

    Erlanson, Daniel A

    2012-01-01

    Fragment-based drug discovery (FBDD) has emerged in the past decade as a powerful tool for discovering drug leads. The approach first identifies starting points: very small molecules (fragments) that are about half the size of typical drugs. These fragments are then expanded or linked together to generate drug leads. Although the origins of the technique date back some 30 years, it was only in the mid-1990s that experimental techniques became sufficiently sensitive and rapid for the concept to be become practical. Since that time, the field has exploded: FBDD has played a role in discovery of at least 18 drugs that have entered the clinic, and practitioners of FBDD can be found throughout the world in both academia and industry. Literally dozens of reviews have been published on various aspects of FBDD or on the field as a whole, as have three books (Jahnke and Erlanson, Fragment-based approaches in drug discovery, 2006; Zartler and Shapiro, Fragment-based drug discovery: a practical approach, 2008; Kuo, Fragment based drug design: tools, practical approaches, and examples, 2011). However, this chapter will assume that the reader is approaching the field with little prior knowledge. It will introduce some of the key concepts, set the stage for the chapters to follow, and demonstrate how X-ray crystallography plays a central role in fragment identification and advancement.

  19. Fragmentation in DNA double-strand breaks

    International Nuclear Information System (INIS)

    Wei Zhiyong; Suzhou Univ., Suzhou; Zhang Lihui; Li Ming; Fan Wo; Xu Yujie

    2005-01-01

    DNA double strand breaks are important lesions induced by irradiations. Random breakage model or quantification supported by this concept is suitable to analyze DNA double strand break data induced by low LET radiation, but deviation from random breakage model is more evident in high LET radiation data analysis. In this work we develop a new method, statistical fragmentation model, to analyze the fragmentation process of DNA double strand breaks. After charged particles enter the biological cell, they produce ionizations along their tracks, and transfer their energies to the cells and break the cellular DNA strands into fragments. The probable distribution of the fragments is obtained under the condition in which the entropy is maximum. Under the approximation E≅E 0 + E 1 l + E 2 l 2 , the distribution functions are obtained as exp(αl + βl 2 ). There are two components, the one proportional to exp(βl 2 ), mainly contributes to the low mass fragment yields, the other component, proportional to exp(αl), decreases slowly as the mass of the fragments increases. Numerical solution of the constraint equations provides parameters α and β. Experimental data, especially when the energy deposition is higher, support the statistical fragmentation model. (authors)

  20. Fragmentation in the branching coral Acropora palmata (Lamarck): growth, survivorship, and reproduction of colonies and fragments.

    Science.gov (United States)

    Lirman

    2000-08-23

    Acropora palmata, a branching coral abundant on shallow reef environments throughout the Caribbean, is susceptible to physical disturbance caused by storms. Accordingly, the survivorship and propagation of this species are tied to its capability to recover after fragmentation. Fragments of A. palmata comprised 40% of ramets within populations that had experienced recent storms. While the survivorship of A. palmata fragments was not directly related to the size of fragments, removal of fragments from areas where they settled was influenced by size. Survivorship of fragments was also affected by type of substratum; the greatest mortality (58% loss within the first month) was observed on sand, whereas fragments placed on top of live colonies of A. palmata fused to the underlying tissue and did not experience any losses. Fragments created by Hurricane Andrew on a Florida reef in August 1992 began developing new growth (proto-branches) 7 months after the storm. The number of proto-branches on fragments was dependent on size, but growth was not affected by the size of fragments. Growth-rates of proto-branches increased exponentially with time (1.7 cm year(-1) for 1993-1994, 2.7 cm year(-1) for 1994-1995, 4.2 cm year(-1) for 1995-1996, and 6.5 cm year(-1) for 1996-1997), taking over 4 years for proto-branches to achieve rates comparable to those of adult colonies on the same reef (6.9 cm year(-1)). In addition to the initial mortality and reduced growth-rates, fragmentation resulted in a loss of reproductive potential. Neither colonies that experienced severe fragmentation nor fragments contained gametes until 4 years after the initial damage. Although A. palmata may survive periodic fragmentation, the long-term effects of this process will depend ultimately on the balance between the benefits and costs of this process.

  1. Recurrent implantation failure: definition and management.

    Science.gov (United States)

    Coughlan, C; Ledger, W; Wang, Q; Liu, Fenghua; Demirol, Aygul; Gurgan, Timur; Cutting, R; Ong, K; Sallam, H; Li, T C

    2014-01-01

    Recurrent implantation failure refers to failure to achieve a clinical pregnancy after transfer of at least four good-quality embryos in a minimum of three fresh or frozen cycles in a woman under the age of 40 years. The failure to implant may be a consequence of embryo or uterine factors. Thorough investigations should be carried out to ascertain whether there is any underlying cause of the condition. Ovarian function should be assessed by measurement of antral follicle count, FSH and anti-Mu¨llerian hormone. Increased sperm DNA fragmentation may be a contributory cause. Various uterine pathology including fibroids, endometrial polyps, congenital anomalies and intrauterine adhesions should be excluded by ultrasonography and hysteroscopy. Hydrosalpinges are a recognized cause of implantation failure and should be excluded by hysterosalpingogram; if necessary, laparoscopy should be performed to confirm or refute the diagnosis. Treatment offered should be evidence based, aimed at improving embryo quality or endometrial receptivity. Gamete donation or surrogacy may be necessary if there is no realistic chance of success with further IVF attempts. Copyright © 2013. Published by Elsevier Ltd.

  2. HETC-3STEP included fragmentation process

    Energy Technology Data Exchange (ETDEWEB)

    Shigyo, Nobuhiro; Iga, Kiminori; Ishibashi, Kenji [Kyushu Univ., Fukuoka (Japan). Faculty of Engineering

    1997-03-01

    High Energy Transport Code (HETC) based on the cascade-evaporation model is modified to calculate the fragmentation cross section. For the cascade process, nucleon-nucleon cross sections are used for collision computation; effective in-medium-corrected cross sections are adopted instead of the original free-nucleon collision. The exciton model is adopted for improvement of backward nucleon-emission cross section for low-energy nucleon-incident events. The fragmentation reaction is incorporated into the original HETC as a subroutine set by the use of the systematics of the reaction. The modified HETC (HETC-3STEP/FRG) reproduces experimental fragment yields to a reasonable degree. (author)

  3. Heart Rate Fragmentation: A Symbolic Dynamical Approach

    Directory of Open Access Journals (Sweden)

    Madalena D. Costa

    2017-11-01

    Full Text Available Background: We recently introduced the concept of heart rate fragmentation along with a set of metrics for its quantification. The term was coined to refer to an increase in the percentage of changes in heart rate acceleration sign, a dynamical marker of a type of anomalous variability. The effort was motivated by the observation that fragmentation, which is consistent with the breakdown of the neuroautonomic-electrophysiologic control system of the sino-atrial node, could confound traditional short-term analysis of heart rate variability.Objective: The objectives of this study were to: (1 introduce a symbolic dynamical approach to the problem of quantifying heart rate fragmentation; (2 evaluate how the distribution of the different dynamical patterns (“words” varied with the participants' age in a group of healthy subjects and patients with coronary artery disease (CAD; and (3 quantify the differences in the fragmentation patterns between the two sample populations.Methods: The symbolic dynamical method employed here was based on a ternary map of the increment NN interval time series and on the analysis of the relative frequency of symbolic sequences (words with a pre-defined set of features. We analyzed annotated, open-access Holter databases of healthy subjects and patients with CAD, provided by the University of Rochester Telemetric and Holter ECG Warehouse (THEW.Results: The degree of fragmentation was significantly higher in older individuals than in their younger counterparts. However, the fragmentation patterns were different in the two sample populations. In healthy subjects, older age was significantly associated with a higher percentage of transitions from acceleration/deceleration to zero acceleration and vice versa (termed “soft” inflection points. In patients with CAD, older age was also significantly associated with higher percentages of frank reversals in heart rate acceleration (transitions from acceleration to

  4. Gluon fragmentation into 3 PJ quarkonium

    International Nuclear Information System (INIS)

    Ma, J.P.

    1995-01-01

    The functions of the gluon fragmentation into 3 P j quarkonium are calculated to order α 2 s . With the recent progress in analysing quarkonium systems in QCD it is possible show how the so called divergence in the limit of the zero-binding energy, which is related to P-wave quarkonia, is treated correctly in the case of fragmentation functions. The obtained fragmentation functions satisfy explicitly at the order of α 2 s the Altarelli-Parisi equation and when z → 0 they behave as z -1 as expected. 19 refs., 7 figs

  5. Origin of fragments in multifragmentation reactions

    International Nuclear Information System (INIS)

    Zbiri, K.; Aichelin, J.

    2003-01-01

    Using the quantum molecular dynamics approach we have started analyzing the results of the recent INDRA experiments at GSI facilities. For the first time we could identify a midrapidity source in which fragments are formed from an almost identical fraction of projectile and target nucleons. In smaller systems we have found this source. Nevertheless the fragment spectra at small and large angles is completely determined by the dynamics. We discuss how fragments are formed in the different regions of phase space and what they tell us about the reaction mechanism. (authors)

  6. Bone fragments a body can make

    Energy Technology Data Exchange (ETDEWEB)

    Stout, S.D.; Ross, L.M. Jr. (Department of Anthropology, University of Missouri, Columbia (USA))

    1991-05-01

    Data obtained from various analytical techniques applied to a number of small bone fragments recovered from a crime scene were used to provide evidence for the occurrence of a fatality. Microscopic and histomorphometric analyses confirmed that the fragments were from a human skull. X-ray microanalysis of darkened areas on the bone fragments revealed a chemical signature that matched the chemical signature of a shotgun pellet recovered at the scene of the crime. The above findings supported the deoxyribonucleic acid (DNA) fingerprint evidence which, along with other evidence, was used to convict a man for the murder of his wife, even though her body was never recovered.

  7. Aspect Ratio Dependence of Impact Fragmentation

    International Nuclear Information System (INIS)

    Inaoka, H.; Toyosawa, E.; Takayasu, H.; Inaoka, H.

    1997-01-01

    A numerical model of three-dimensional impact fragmentation produces a power-law cumulative fragment mass distribution followed by a flat tail. The result is consistent with an experimental result in a recent paper by Meibom and Balslev [Phys. Rev. Lett. 76, 2492 (1996)]. Our numerical simulation also implies that the fragment mass distribution changes from a power law with a flat tail to a power law with a sudden cutoff, depending on the aspect ratio of the fractured object. copyright 1997 The American Physical Society

  8. Origin of fragments in multifragmentation reactions

    International Nuclear Information System (INIS)

    Zbiri, K.; Aichelin, J.

    2005-01-01

    Using the quantum molecular dynamics approach we have started to analyze the results of the recent INDRA experiments at GSI experiments. For the first time we could identify a midrapidity source in which fragments are formed from a almost identical fraction of projectile and target nucleons. In smaller systems we have not found this source. Nevertheless the fragment spectra at small and large angles are completely determined by the dynamics. We discuss how fragments are formed in the different regions of phase space and what they tell us about the reaction mechanism. (author)

  9. Immune mediated liver failure.

    Science.gov (United States)

    Wang, Xiaojing; Ning, Qin

    2014-01-01

    Liver failure is a clinical syndrome of various etiologies, manifesting as jaundice, encephalopathy, coagulopathy and circulatory dysfunction, which result in subsequent multiorgan failure. Clinically, liver failure is classified into four categories: acute, subacute, acute-on-chronic and chronic liver failure. Massive hepatocyte death is considered to be the core event in the development of liver failure, which occurs when the extent of hepatocyte death is beyond the liver regenerative capacity. Direct damage and immune-mediated liver injury are two major factors involved in this process. Increasing evidence has suggested the essential role of immune-mediated liver injury in the pathogenesis of liver failure. Here, we review the evolved concepts concerning the mechanisms of immune-mediated liver injury in liver failure from human and animal studies. Both innate and adaptive immunity, especially the interaction of various immune cells and molecules as well as death receptor signaling system are discussed. In addition, we highlight the concept of "immune coagulation", which has been shown to be related to the disease progression and liver injury exacerbation in HBV related acute-on-chronic liver failure.

  10. The Reconstruction of Failure

    Science.gov (United States)

    Turner, Ralph H.

    1972-01-01

    Seeks to explain the use of ideologies concerning the failure or non-failure in American education in terms of the struggle of sponsoring and professional groups to establish or maintain position on the social scene and, correspondingly, to gain control over those clienteles which are relevant to drives for social or professional mobility. (RJ)

  11. Success by Failure

    Science.gov (United States)

    Andrews, Benjamin D.

    2017-01-01

    By taking the step to talk openly about his failure, the author stumbled upon one of several important lessons that he learned from this experience. The author recognized that he did not have to pretend anymore. In this article, the author shares his story of developing a "growth mindset" to overcome his own failure and support his…

  12. Central oxygen pipeline failure

    African Journals Online (AJOL)

    surgical intensive care unit (ICU), with two patients on full ventilation and ... uncertainty around the cause of the failure and the restoration, .... soon as its level also falls below three tons. Should ... (properly checked and closed prior to each anaesthetic). ... in use at the time of the central oxygen pipeline failure at Tygerberg.

  13. Radiology of renal failure

    International Nuclear Information System (INIS)

    Griffiths, H.J.

    1990-01-01

    This book covers most aspects of imaging studies in patients with renal failure. The initial chapter provides basic information on contrast agents, intravenous urography, and imaging findings in the urinary tract disorders responsible for renal failure and in patients who have undergone transplantation. It illustrates common gastro-intestinal abnormalities seen on barium studies in patients with renal failure. It illustrates the cardiopulmonary complications of renal failure and offers advice for radiologic differentiation. It details different aspects of skeletal changes in renal failure, including a basic description of the pathophysiology of the changes; many excellent illustrations of classic bone changes, arthritis, avascular necrosis, and soft-tissue calcifications; and details of bone mineral analysis

  14. SOR-ring failure

    International Nuclear Information System (INIS)

    Kitamura, Hideo

    1981-01-01

    It was in the autumn of 1976 that the SOR-ring (synchrotron radiation storage ring) has commenced the regular operation. Since then, the period when the operation was interrupted due to the failures of SOR-ring itself is in total about 8 weeks. Failures and accidents have occurred most in the vacuum system. Those failure experiences are described on the vacuum, electromagnet, radio-frequency acceleration and beam transport systems with their interrupted periods. The eleven failures in the vacuum system have been reported, such as bellows breakage in a heating-evacuating period, leakage from the bellows of straight-through valves (made in U.S.A. and Japan), and leakage from the joint flange of the vacuum system. The longest interruption was 5 weeks due to the failure of a domestically manufactured straight-through valve. The failures of the electromagnet system involve the breakage in a cooling water system, short circuit of a winding in the Q magnet power transformer, blow of a fuse protecting the deflection magnet power source by the current less than the rating, and others. The failures of the RF acceleration system include the breakage of an output electronic tube the breakage of a cavity ceramic, RF voltage fluctuation due to the contact deterioration at a cavity electrode, and the failure of grid bias power source. It is necessary to select the highly reliable components for the vacuum system because the vacuum system failures require longer time for recovery, and very likely to induce secondary and tertiary failures. (Wakatsuki, Y.)

  15. Fission fragment assisted reactor concept for space propulsion: Foil reactor

    International Nuclear Information System (INIS)

    Wright, S.A.

    1991-01-01

    The concept is to fabricate a reactor using thin films or foils of uranium, uranium oxide and then to coat them on substrates. These coatings would be made so thin as to allow the escaping fission fragments to directly heat a hydrogen propellant. The idea was studied of direct gas heating and direct gas pumping in a nuclear pumped laser program. Fission fragments were used to pump lasers. In this concept two substrates are placed opposite each other. The internal faces are coated with thin foil of uranium oxide. A few of the advantages of this technology are listed. In general, however, it is felt that if one look at all solid core nuclear thermal rockets or nuclear thermal propulsion methods, one is going to find that they all pretty much look the same. It is felt that this reactor has higher potential reliability. It has low structural operating temperatures, very short burn times, with graceful failure modes, and it has reduced potential for energetic accidents. Going to a design like this would take the NTP community part way to some of the very advanced engine designs, such as the gas core reactor, but with reduced risk because of the much lower temperatures

  16. Burnout and gate rupture of power MOS transistors with fission fragments of 252Cf

    International Nuclear Information System (INIS)

    Tang Benqi; Wang Yanping; Geng Bin; Chen Xiaohua; He Chaohui; Yang Hailiang

    2000-01-01

    A study to determine the single event burnout (SEB) and single event gate rupture (SEGR) sensitivities of power MOSFET devices is carried out by exposure to fission fragments from 252 Cf source. The test method, test results, a description of observed burnout current waveforms and a discussion of a possible failure mechanism are presented. The test results include the observed dependence upon applied drain or gate to source bias and effect of external capacitors and limited resistors

  17. Dihadron fragmentation function and its evolution

    International Nuclear Information System (INIS)

    Majumder, A.; Wang Xinnian

    2004-01-01

    Dihadron fragmentation functions and their evolution are studied in the process of e + e - annihilation. Under the collinear factorization approximation and facilitated by the cut-vertex technique, the two hadron inclusive cross section at leading order is shown to factorize into a short distance parton cross section and a long distance dihadron fragmentation function. We provide the definition of such a dihadron fragmentation function in terms of parton matrix elements and derive its Dokshitzer-Gribov-Lipatov-Altarelli-Parisi evolution equation at leading log. The evolution equation for the nonsinglet quark fragmentation function is solved numerically with a simple ansatz for the initial condition and results are presented for cases of physical interest

  18. A Current Logical Framework: The Propositional Fragment

    National Research Council Canada - National Science Library

    Watkins, Kevin

    2003-01-01

    We present the propositional fragment CLF of the Concurrent Logical Framework (CLF). CLF extends the Linear Logical Framework to allow the natural representation of concurrent computations in an object language...

  19. Complementary DNA-amplified fragment length polymorphism ...

    African Journals Online (AJOL)

    Complementary DNA-amplified fragment length polymorphism (AFLP-cDNA) analysis of differential gene expression from the xerophyte Ammopiptanthus mongolicus in response to cold, drought and cold together with drought.

  20. Integration of fragment screening and library design.

    Science.gov (United States)

    Siegal, Gregg; Ab, Eiso; Schultz, Jan

    2007-12-01

    With more than 10 years of practical experience and theoretical analysis, fragment-based drug discovery (FBDD) has entered the mainstream of the pharmaceutical and biotech industries. An array of biophysical techniques has been used to detect the weak interaction between a fragment and the target. Each technique presents its own requirements regarding the fragment collection and the target; therefore, in order to optimize the potential of FBDD, the nature of the target should be a driving factor for simultaneous development of both the library and the screening technology. A roadmap is now available to guide fragment-to-lead evolution when structural information is available. The next challenge is to apply FBDD to targets for which high-resolution structural information is not available.

  1. An improved algorithm for MFR fragment assembly

    International Nuclear Information System (INIS)

    Kontaxis, Georg

    2012-01-01

    A method for generating protein backbone models from backbone only NMR data is presented, which is based on molecular fragment replacement (MFR). In a first step, the PDB database is mined for homologous peptide fragments using experimental backbone-only data i.e. backbone chemical shifts (CS) and residual dipolar couplings (RDC). Second, this fragment library is refined against the experimental restraints. Finally, the fragments are assembled into a protein backbone fold using a rigid body docking algorithm using the RDCs as restraints. For improved performance, backbone nuclear Overhauser effects (NOEs) may be included at that stage. Compared to previous implementations of MFR-derived structure determination protocols this model-building algorithm offers improved stability and reliability. Furthermore, relative to CS-ROSETTA based methods, it provides faster performance and straightforward implementation with the option to easily include further types of restraints and additional energy terms.

  2. Fragment Length of Circulating Tumor DNA.

    Science.gov (United States)

    Underhill, Hunter R; Kitzman, Jacob O; Hellwig, Sabine; Welker, Noah C; Daza, Riza; Baker, Daniel N; Gligorich, Keith M; Rostomily, Robert C; Bronner, Mary P; Shendure, Jay

    2016-07-01

    Malignant tumors shed DNA into the circulation. The transient half-life of circulating tumor DNA (ctDNA) may afford the opportunity to diagnose, monitor recurrence, and evaluate response to therapy solely through a non-invasive blood draw. However, detecting ctDNA against the normally occurring background of cell-free DNA derived from healthy cells has proven challenging, particularly in non-metastatic solid tumors. In this study, distinct differences in fragment length size between ctDNAs and normal cell-free DNA are defined. Human ctDNA in rat plasma derived from human glioblastoma multiforme stem-like cells in the rat brain and human hepatocellular carcinoma in the rat flank were found to have a shorter principal fragment length than the background rat cell-free DNA (134-144 bp vs. 167 bp, respectively). Subsequently, a similar shift in the fragment length of ctDNA in humans with melanoma and lung cancer was identified compared to healthy controls. Comparison of fragment lengths from cell-free DNA between a melanoma patient and healthy controls found that the BRAF V600E mutant allele occurred more commonly at a shorter fragment length than the fragment length of the wild-type allele (132-145 bp vs. 165 bp, respectively). Moreover, size-selecting for shorter cell-free DNA fragment lengths substantially increased the EGFR T790M mutant allele frequency in human lung cancer. These findings provide compelling evidence that experimental or bioinformatic isolation of a specific subset of fragment lengths from cell-free DNA may improve detection of ctDNA.

  3. Quark fragmentation into 3PJ quarkonium

    International Nuclear Information System (INIS)

    Ma, J.P.

    1996-01-01

    The functions of parton fragmentation into 3 P J quarkonium at order α 2 s are calculated, where the parton can be a heavy or a light quark. The obtained functions explicitly satisfy the Altarelli-Parisi equation and they are divergent, behaving as z -1 near z = O. However, if one choses the renormalization scale as twice of the heavy quark mass, the fragmentation functions are regular over the whole range of z. 15 refs., 2 figs

  4. The lund Monte Carlo for jet fragmentation

    International Nuclear Information System (INIS)

    Sjoestrand, T.

    1982-03-01

    We present a Monte Carlo program based on the Lund model for jet fragmentation. Quark, gluon, diquark and hadron jets are considered. Special emphasis is put on the fragmentation of colour singlet jet systems, for which energy, momentum and flavour are conserved explicitly. The model for decays of unstable particles, in particular the weak decay of heavy hadrons, is described. The central part of the paper is a detailed description on how to use the FORTRAN 77 program. (Author)

  5. Fragmentation of Continental United States Forests

    Science.gov (United States)

    Kurt H. Riitters; James D. Wickham; Robert V. O' Neill; K. Bruce Jones; Elizabeth R. Smith; John W. Coulston; Timothy G. Wade; Jonathan H. Smith

    2002-01-01

    We report a multiple-scale analysis of forest fragmentation based on 30-m (0.09 ha pixel-1) land- cover maps for the conterminous United States. Each 0.09-ha unit of forest was classified according to fragmentation indexes measured within the surrounding landscape, for five landscape sizes including 2.25, 7.29, 65.61, 590.49, and 5314.41 ha....

  6. Rapid detection of dihydropteroate polymorphism in AIDS-related Pneumocystis carinii pneumonia by restriction fragment length polymorphism

    DEFF Research Database (Denmark)

    Helweg-Larsen, J; Eugen-Olsen, Jesper; Lundgren, B

    2000-01-01

    are associated with failure of sulpha prophylaxis and increased mortality in HIV-1 positive patients with PCP, suggesting that DHPS mutations may cause sulpha resistance. To facilitate detection of DHPS mutations we developed a restriction fragment length polymorphism (RFLP) assay, detecting mutations at codon...

  7. Fragman: an R package for fragment analysis.

    Science.gov (United States)

    Covarrubias-Pazaran, Giovanny; Diaz-Garcia, Luis; Schlautman, Brandon; Salazar, Walter; Zalapa, Juan

    2016-04-21

    Determination of microsatellite lengths or other DNA fragment types is an important initial component of many genetic studies such as mutation detection, linkage and quantitative trait loci (QTL) mapping, genetic diversity, pedigree analysis, and detection of heterozygosity. A handful of commercial and freely available software programs exist for fragment analysis; however, most of them are platform dependent and lack high-throughput applicability. We present the R package Fragman to serve as a freely available and platform independent resource for automatic scoring of DNA fragment lengths diversity panels and biparental populations. The program analyzes DNA fragment lengths generated in Applied Biosystems® (ABI) either manually or automatically by providing panels or bins. The package contains additional tools for converting the allele calls to GenAlEx, JoinMap® and OneMap software formats mainly used for genetic diversity and generating linkage maps in plant and animal populations. Easy plotting functions and multiplexing friendly capabilities are some of the strengths of this R package. Fragment analysis using a unique set of cranberry (Vaccinium macrocarpon) genotypes based on microsatellite markers is used to highlight the capabilities of Fragman. Fragman is a valuable new tool for genetic analysis. The package produces equivalent results to other popular software for fragment analysis while possessing unique advantages and the possibility of automation for high-throughput experiments by exploiting the power of R.

  8. Microstructural characterization of pipe bomb fragments

    International Nuclear Information System (INIS)

    Gregory, Otto; Oxley, Jimmie; Smith, James; Platek, Michael; Ghonem, Hamouda; Bernier, Evan; Downey, Markus; Cumminskey, Christopher

    2010-01-01

    Recovered pipe bomb fragments, exploded under controlled conditions, have been characterized using scanning electron microscopy, optical microscopy and microhardness. Specifically, this paper examines the microstructural changes in plain carbon-steel fragments collected after the controlled explosion of galvanized, schedule 40, continuously welded, steel pipes filled with various smokeless powders. A number of microstructural changes were observed in the recovered pipe fragments: deformation of the soft alpha-ferrite grains, deformation of pearlite colonies, twin formation, bands of distorted pearlite colonies, slip bands, and cross-slip bands. These microstructural changes were correlated with the relative energy of the smokeless powder fillers. The energy of the smokeless powder was reflected in a reduction in thickness of the pipe fragments (due to plastic strain prior to fracture) and an increase in microhardness. Moreover, within fragments from a single pipe, there was a radial variation in microhardness, with the microhardness at the outer wall being greater than that at the inner wall. These findings were consistent with the premise that, with the high energy fillers, extensive plastic deformation and wall thinning occurred prior to pipe fracture. Ultimately, the information collected from this investigation will be used to develop a database, where the fragment microstructure and microhardness will be correlated with type of explosive filler and bomb design. Some analyses, specifically wall thinning and microhardness, may aid in field characterization of explosive devices.

  9. Fragmentation of molten core material by sodium

    International Nuclear Information System (INIS)

    Chu, T.Y.

    1982-01-01

    A series of scoping experiments was performed to study the fragmentation of prototypic high temperature melts in sodium. The quantity of melt involved was at least one order of magnitude larger than previous experiments. Two modes of contact were used: melt streaming into sodium and sodium into melt. The average bulk fragment size distribution was found to be in the range of previous data and the average size distribution was found to be insensitive to mode of contact. SEM studies showed that the metal component typically fragmented in the molten phase while the oxide component fragmented in the solid phase. For UO 2 -ZrO 2 /stainless steel melts no sigificant spatial separation of the metal and oxide was observed. The fragment size distribution was stratified vertically in the debris bed in all cases. While the bulk fragment size showed generally consistent trends, the individual experiments were sufficiently different to cause different degrees of stratification in the debris bed. For the highly stratified beds the permeability can decrease by as much as a factor of 20 from the bottom to the top of the bed

  10. Nondetectability of restriction fragments and independence of DNA fragment sizes within and between loci in RFLP typing of DNA

    Energy Technology Data Exchange (ETDEWEB)

    Chakraborty, R.; Zhong, Y.; Jin, L. (Univ. of Texas Health Science Center, Houston, TX (United States)); Budowle, B. (FBI Academy, Quantico, VA (United States))

    1994-08-01

    The authors provide experimental evidence showing that, during the restriction-enzyme digestion of DNA samples, some of the HaeIII-digested DNA fragments are small enough to prevent their reliable sizing on a Southern gel. As a result of such nondetectability of DNA fragments, individuals who show a single-band DNA profile at a VNTR locus may not necessarily be true homozygotes. In a population database, when the presence of such nondetectable alleles is ignored, they show that a pseudodependence of alleles within as well as across loci may occur. Using a known statistical method, under the hypothesis of independence of alleles within loci, they derive an efficient estimate of null allele frequency, which may be subsequently used for testing allelic independence within and across loci. The estimates of null allele frequencies, thus derived, are shown to agree with direct experimental data on the frequencies of HaeIII-null alleles. Incorporation of null alleles into the analysis of the forensic VNTR database suggests that the assumptions of allelic independence within and between loci are appropriate. In contrast, a failure to incorporate the occurrence of null alleles would provide a wrong inference regarding the independence of alleles within and between loci. 47 refs., 2 figs., 4 tabs.

  11. Fragment library design: using cheminformatics and expert chemists to fill gaps in existing fragment libraries.

    Science.gov (United States)

    Kutchukian, Peter S; So, Sung-Sau; Fischer, Christian; Waller, Chris L

    2015-01-01

    Fragment based screening (FBS) has emerged as a mainstream lead discovery strategy in academia, biotechnology start-ups, and large pharma. As a prerequisite of FBS, a structurally diverse library of fragments is desirable in order to identify chemical matter that will interact with the range of diverse target classes that are prosecuted in contemporary screening campaigns. In addition, it is also desirable to offer synthetically amenable starting points to increase the probability of a successful fragment evolution through medicinal chemistry. Herein we describe a method to identify biologically relevant chemical substructures that are missing from an existing fragment library (chemical gaps), and organize these chemical gaps hierarchically so that medicinal chemists can efficiently navigate the prioritized chemical space and subsequently select purchasable fragments for inclusion in an enhanced fragment library.

  12. Magnet failure workshop

    Energy Technology Data Exchange (ETDEWEB)

    Marston, P G [Massachusetts Institute of Technology, Cambridge (U.S.A.); Desportes, H [C.E.N.-Saclay, 91 - Gif-sur-Yvette (France); Morpurgo, M [C.E.R.N., Geneva (Switzerland); Komarek, P [Kernforschungszentrum, Karlsruhe (Germany, FR); Van Hulst, K [University of Nijmegen (The Netherlands); Hackley, D [General Dynamics Convair, San Diego, CA (U.S.A.); Young, J L [Westinghouse Electric Corporation, East Pittsburgh, PE (U.S.A.); Kibbe, K [Oak Ridge National Laboratory (U.S.A.)

    1984-01-01

    The dictionary defines failure as nonperformance or an unacceptable want of success. (The definition implies that the results should have been avoided). In an emerging technology such as ours, the boundaries of expectations and ''unacceptable success'' are often ill defined. Failures are often touted as hugh successes (occasionally rightfully so) and exceptional technological achievement can become dismal failure (if expectations are too high). We all, however, have experienced problems of one sort or another and the basic purpose of the workshop was simply to communicate these so that new or future workers don't make the same mistakes.

  13. Failure Diameter Resolution Study

    Energy Technology Data Exchange (ETDEWEB)

    Menikoff, Ralph [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-12-19

    Previously the SURFplus reactive burn model was calibrated for the TATB based explosive PBX 9502. The calibration was based on fitting Pop plot data, the failure diameter and the limiting detonation speed, and curvature effect data for small curvature. The model failure diameter is determined utilizing 2-D simulations of an unconfined rate stick to find the minimum diameter for which a detonation wave propagates. Here we examine the effect of mesh resolution on an unconfined rate stick with a diameter (10mm) slightly greater than the measured failure diameter (8 to 9 mm).

  14. Magnet failure workshop

    International Nuclear Information System (INIS)

    Marston, P.G.; Desportes, H.; Morpurgo, M.; Komarek, P.; Van Hulst, K.; Hackley, D.; Young, J.L.; Kibbe, K.

    1984-01-01

    The dictionary defines failure as nonperformance or an unacceptable want of success. (The definition implies that the results should have been avoided). In an emerging technology such as ours, the boundaries of expectations and ''unacceptable success'' are often ill defined. Failures are often touted as hugh successes (occasionally rightfully so) and exceptional technological achievement can become dismal failure (if expectations are too high). We all, however, have experienced problems of one sort or another and the basic purpose of the workshop was simply to communicate these so that new or future workers don't make the same mistakes

  15. Nutrition in Heart Failure

    OpenAIRE

    Reci Meseri

    2013-01-01

    Heart failure is defined as decreased ability of heart due to various reasons. It%u2019s seen 2-3% but the prevalence increases sharply after the age of seventy. The objectives of nutrition therapy in heart failure are to prevent from water retention and edema, to avoid from hard digestion and to offer a balanced diet. In order to avoid fluid retention and edema, daily sodium and fluid intake must be monitored carefully. Main dilemma of the heart failure patients is the obesity-cachexia dilem...

  16. Neurological Respiratory Failure

    Directory of Open Access Journals (Sweden)

    Mohan Rudrappa

    2018-01-01

    Full Text Available West Nile virus infection in humans is mostly asymptomatic. Less than 1% of neuro-invasive cases show a fatality rate of around 10%. Acute flaccid paralysis of respiratory muscles leading to respiratory failure is the most common cause of death. Although the peripheral nervous system can be involved, isolated phrenic nerve palsy leading to respiratory failure is rare and described in only two cases in the English literature. We present another case of neurological respiratory failure due to West Nile virus-induced phrenic nerve palsy. Our case reiterates the rare, but lethal, consequences of West Nile virus infection, and the increase of its awareness among physicians.

  17. Hypervelocity Impact Test Fragment Modeling: Modifications to the Fragment Rotation Analysis and Lightcurve Code

    Science.gov (United States)

    Gouge, Michael F.

    2011-01-01

    Hypervelocity impact tests on test satellites are performed by members of the orbital debris scientific community in order to understand and typify the on-orbit collision breakup process. By analysis of these test satellite fragments, the fragment size and mass distributions are derived and incorporated into various orbital debris models. These same fragments are currently being put to new use using emerging technologies. Digital models of these fragments are created using a laser scanner. A group of computer programs referred to as the Fragment Rotation Analysis and Lightcurve code uses these digital representations in a multitude of ways that describe, measure, and model on-orbit fragments and fragment behavior. The Dynamic Rotation subroutine generates all of the possible reflected intensities from a scanned fragment as if it were observed to rotate dynamically while in orbit about the Earth. This calls an additional subroutine that graphically displays the intensities and the resulting frequency of those intensities as a range of solar phase angles in a Probability Density Function plot. This document reports the additions and modifications to the subset of the Fragment Rotation Analysis and Lightcurve concerned with the Dynamic Rotation and Probability Density Function plotting subroutines.

  18. Acute heart failure syndrome

    African Journals Online (AJOL)

    and the classical syndrome of chronic persistent heart failure develops. The vast ... Flash pulmonary oedema: This is a severely elevated blood pressure with an .... (CPAP or bilevelNPPV) for cardiogenic pulmonary edema (review). Cochrane.

  19. Acute Liver Failure

    Science.gov (United States)

    ... can cause acute liver failure. It is an industrial chemical found in refrigerants and solvents for waxes, varnishes ... measures when spraying insecticides, fungicides, paint and other toxic chemicals. Follow product instructions carefully. Watch what gets on ...

  20. Failure to Fail

    Directory of Open Access Journals (Sweden)

    Samuel Vriezen

    2013-07-01

    Full Text Available Between pessimism and optimism, Samuel Vriezen attempts to intuit a third way through an assessment of failure and negativity in the consonances and tensions between the prosody of Irish playwright Samuel Becekett and American poet Gertrude Stein.

  1. Inverter ratio failure detector

    Science.gov (United States)

    Wagner, A. P.; Ebersole, T. J.; Andrews, R. E. (Inventor)

    1974-01-01

    A failure detector which detects the failure of a dc to ac inverter is disclosed. The inverter under failureless conditions is characterized by a known linear relationship of its input and output voltages and by a known linear relationship of its input and output currents. The detector includes circuitry which is responsive to the detector's input and output voltages and which provides a failure-indicating signal only when the monitored output voltage is less by a selected factor, than the expected output voltage for the monitored input voltage, based on the known voltages' relationship. Similarly, the detector includes circuitry which is responsive to the input and output currents and provides a failure-indicating signal only when the input current exceeds by a selected factor the expected input current for the monitored output current based on the known currents' relationship.

  2. Acute kidney failure

    Science.gov (United States)

    ... Renal failure - acute; ARF; Kidney injury - acute Images Kidney anatomy References Devarajan P. Biomarkers for assessment of renal function during acute kidney injury. In: Alpern RJ, Moe OW, Caplan M, ...

  3. Acute heart failure

    OpenAIRE

    Sénior Sánchez, Juan Manuel; Gándara Ricardo, Jairo Alfonso

    2015-01-01

    We describe the clinical case of a 26 year-old woman who came to Hospital Universitario San Vicente Fundación (Medellín, Colombia) with symptoms and signs of acute heart failure. She had been previously diagnosed with chronic heart failure with reduced ejection fraction without clear origin, pulmonary thromboembolism and ischemic stroke, without optimal neurohormonal modulation. She was admitted with clinical findings of fluid overload and low tissue perfusion, with inotropic support requirem...

  4. Dynamic fragmentation of laser shock-melted tin: experiment and modelling

    Energy Technology Data Exchange (ETDEWEB)

    De Resseguier, T. [CNRS ENSMA, Lab Combust and Deton, F-86961 Futuroscope (France); Signor, L.; Dragon, A. [CNRS ENSMA, Mecan and Phys Mat Lab, F-86961 Futuroscope (France); Signor, L.; Roy, G. [CEA Valduc, 21 - Is-sur-Tille (France)

    2010-07-01

    Dynamic fragmentation of shock-loaded metals is an issue of considerable importance for both basic science and a variety of technological applications, such as pyrotechnics or inertial confinement fusion, the latter involving high energy laser irradiation of thin metallic shells. Whereas spall fracture in solid materials has been extensively studied for many years, little data can be found yet about the evolution of this phenomenon after partial or full melting on compression or on release. Here, we present an investigation of dynamic fragmentation in laser shock-melted tin, from the 'micro-spall' process (ejection of a cloud of fine droplets) occurring upon reflection of the compressive pulse from the target free surface, to the late rupture observed in the un-spalled melted layer (leading to the formation of larger spherical fragments). Experimental results consist of time-resolved velocity measurements and post-shock observations of recovered targets and fragments. They provide original information regarding the loss of tensile strength associated with melting, the cavitation mechanism likely to occur in the melted metal, the sizes of the subsequent fragments and their ejection velocities. A theoretical description based on an energetic approach adapted to the case of a liquid metal is implemented as a failure criterion in a one-dimensional hydro-code including a multi-phase equation of state for tin. The resulting predictions of the micro-spall process are compared with experimental data. In particular, the use of a new experimental technique to quantify the fragment size distributions leads to a much better agreement with theory than previously reported. Finally, a complementary approach focused on cavitation is proposed to evaluate the role of this phenomenon in the fragmentation of the melted metal. (authors)

  5. Rapid decompression and desorption induced energetic failure in coal

    Directory of Open Access Journals (Sweden)

    Shugang Wang

    2015-06-01

    Full Text Available In this study, laboratory experiments are conducted to investigate the rapid decompression and desorption induced energetic failure in coal using a shock tube apparatus. Coal specimens are recovered from Colorado at a depth of 610 m. The coal specimens are saturated with the strong sorbing gas CO2 for a certain period and then the rupture disc is suddenly broken on top of the shock tube to generate a shock wave propagating upwards and a rarefaction wave propagating downwards through the specimen. This rapid decompression and desorption has the potential to cause energetic fragmentation in coal. Three types of behaviors in coal after rapid decompression are found, i.e. degassing without fragmentation, horizontal fragmentation, and vertical fragmentation. We speculate that the characteristics of fracture network (e.g. aperture, spacing, orientation and stiffness and gas desorption play a role in this dynamic event as coal can be considered as a dual porosity, dual permeability, dual stiffness sorbing medium. This study has important implications in understanding energetic failure process in underground coal mines such as coal gas outbursts.

  6. A Failure Locus for Hydrogen Assisted Failure

    DEFF Research Database (Denmark)

    Fuentes-Alonso, Sandra; Harris, Zach D.; Burns, James T.

    2017-01-01

    of a hydrogen-dependent traction separation law. A special control algorithm is employed to overcome numerical instabilities intrinsically associated with cohesive zone formulations. The fracture energy is degraded by means of an experimentally-motivated hydrogen degradation relation. Numerical results provide...... important insight into the failure process, enabling to identify critical values of hydrogen concentration and remote stresses that trigger cracking. The work builds upon previous works by the authors and brings important insight into the technologically important problem of hydrogen assisted cracking....

  7. Global-Scale Patterns of Forest Fragmentation

    Directory of Open Access Journals (Sweden)

    Kurt Riitters

    2000-12-01

    Full Text Available We report an analysis of forest fragmentation based on 1-km resolution land-cover maps for the globe. Measurements in analysis windows from 81 km 2 (9 x 9 pixels, "small" scale to 59,049 km 2 (243 x 243 pixels, "large" scale were used to characterize the fragmentation around each forested pixel. We identified six categories of fragmentation (interior, perforated, edge, transitional, patch, and undetermined from the amount of forest and its occurrence as adjacent forest pixels. Interior forest exists only at relatively small scales; at larger scales, forests are dominated by edge and patch conditions. At the smallest scale, there were significant differences in fragmentation among continents; within continents, there were significant differences among individual forest types. Tropical rain forest fragmentation was most severe in North America and least severe in Europe-Asia. Forest types with a high percentage of perforated conditions were mainly in North America (five types and Europe-Asia (four types, in both temperate and subtropical regions. Transitional and patch conditions were most common in 11 forest types, of which only a few would be considered as "naturally patchy" (e.g., dry woodland. The five forest types with the highest percentage of interior conditions were in North America; in decreasing order, they were cool rain forest, coniferous, conifer boreal, cool mixed, and cool broadleaf.

  8. Global-scale patterns of forest fragmentation

    Science.gov (United States)

    Riitters, K.; Wickham, J.; O'Neill, R.; Jones, B.; Smith, E.

    2000-01-01

    We report an analysis of forest fragmentation based on 1-km resolution land-cover maps for the globe. Measurements in analysis windows from 81 km 2 (9 ?? 9 pixels, "small" scale) to 59,049 km 2 (243 ?? 243 pixels, "large" scale) were used to characterize the fragmentation around each forested pixel. We identified six categories of fragmentation (interior, perforated, edge, transitional, patch, and undetermined) from the amount of forest and its occurrence as adjacent forest pixels. Interior forest exists only at relatively small scales; at larger scales, forests are dominated by edge and patch conditions. At the smallest scale, there were significant differences in fragmentation among continents; within continents, there were significant differences among individual forest types. Tropical rain forest fragmentation was most severe in North America and least severe in Europe - Asia. Forest types with a high percentage of perforated conditions were mainly in North America (five types) and Europe - Asia (four types), in both temperate and subtropical regions. Transitional and patch conditions were most common in 11 forest types, of which only a few would be considered as "naturally patchy" (e.g., dry woodland). The five forest types with the highest percentage of interior conditions were in North America; in decreasing order, they were cool rain forest, coniferous, conifer boreal, cool mixed, and cool broadleaf. Copyright ?? 2000 by The Resilience Alliance.

  9. Light fragment formation at intermediate energies

    International Nuclear Information System (INIS)

    Boal, D.H.

    1982-03-01

    This paper concerns itself mainly with the production of energetic protons and light fragments at wide angles. The experiments point to nucleon emission in proton-induced reactions as involving a mechanism in which the observed nucleon is directly knocked out of the nucleus. A similar feature seems to be required to explain (p,F) and (e,F) reactions: an energetic nucleon is produced in one scattering of the projectile, and the struck nucleon subsequently loses some of its energy as it traverses the remaining part of the nucleus, gathering up other nucleons as it goes, to become a fragment. This is what one might call the extreme snowball model, and a more accurate description probably involves multiple scattering of the projectile in addition to the extreme snowball contribution. This will be particularly true for fragments in the mass 6 to 9 region. This scenario also appears to apply to deuteron-induced fragment production. However, for alpha-induced reactions it would appear that the nucleons forming a fragment can originate from collisions involving different incident nucleons in the projectile. For heavy ions, this effect is even stronger, and the snowball contribution is greatly reduced compared to that of the traditional coalescence model

  10. Impact fragmentation of a brittle metal compact

    Science.gov (United States)

    Tang, Megan; Hooper, Joseph P.

    2018-05-01

    The fragmentation behavior of a metal powder compact which is ductile in compression but brittle in tension is studied via impact experiments and analytical models. Consolidated metal compacts were prepared via cold-isostatic pressing of powder at 380 MPa followed by moderate annealing at 365 °C. The resulting zinc material is ductile and strain-hardening in high-rate uniaxial compression like a traditional metal, but is elastic-brittle in tension with a fracture toughness comparable to a ceramic. Cylindrical samples were launched up to 800 m/s in a gas gun into thin aluminum perforation targets, subjecting the projectile to a complex multiaxial and time-dependent stress state that leads to catastrophic fracture. A soft-catch mechanism using low-density artificial snow was developed to recover the impact debris, and collected fragments were analyzed to determine their size distribution down to 30 μm. Though brittle fracture occurs along original particle boundaries, no power-law fragmentation behavior was observed as is seen in other low-toughness materials. An analytical theory is developed to predict the characteristic fragment size accounting for both the sharp onset of fragmentation and the effect of increasing impact velocity.

  11. Rock fragmentation control in opencast blasting

    Directory of Open Access Journals (Sweden)

    P.K. Singh

    2016-04-01

    Full Text Available The blasting operation plays a pivotal role in the overall economics of opencast mines. The blasting sub-system affects all the other associated sub-systems, i.e. loading, transport, crushing and milling operations. Fragmentation control through effective blast design and its effect on productivity are the challenging tasks for practicing blasting engineer due to inadequate knowledge of actual explosive energy released in the borehole, varying initiation practice in blast design and its effect on explosive energy release characteristic. This paper describes the result of a systematic study on the impact of blast design parameters on rock fragmentation at three mines in India. The mines use draglines and shovel–dumper combination for removal of overburden. Despite its pivotal role in controlling the overall economics of a mining operation, the expected blasting performance is often judged almost exclusively on the basis of poorly defined parameters such as powder factor and is often qualitative which results in very subjective assessment of blasting performance. Such an approach is very poor substitutes for accurate assessment of explosive and blasting performance. Ninety one blasts were conducted with varying blast designs and charging patterns, and their impacts on the rock fragmentation were documented. A high-speed camera was deployed to record the detonation sequences of the blasts. The efficiency of the loading machines was also correlated with the mean fragment size obtained from the fragmentation analyses.

  12. Molten aluminum alloy fuel fragmentation experiments

    International Nuclear Information System (INIS)

    Gabor, J.D.; Purviance, R.T.; Cassulo, J.C.; Spencer, B.W.

    1992-01-01

    Experiments were conducted in which molten aluminum alloys were injected into a 1.2 m deep pool of water. The parameters varied were (i) injectant material (8001 aluminum alloy and 12.3 wt% U-87.7 wt% Al), (ii) melt superheat (O to 50 K), (iii) water temperature (313, 343 and 373 K) and (iv) size and geometry of the pour stream (5, 10 and 20 mm diameter circular and 57 mm annular). The pour stream fragmentation was dominated by surface tension with large particles (∼30 mm) being formed from varicose wave breakup of the 10-mm circular pours and from the annular flow off a 57 mm diameter tube. The fragments produced by the 5 mm circular et were smaller (∼ mm), and the 20 mm jet which underwent sinuous wave breakup produced ∼100 mm fragments. The fragments froze to form solid particles in 313 K water, and when the water was ≥343 K, the melt fragments did not freeze during their transit through 1.2 m of water

  13. Supramolecular gel electrophoresis of large DNA fragments.

    Science.gov (United States)

    Tazawa, Shohei; Kobayashi, Kazuhiro; Oyoshi, Takanori; Yamanaka, Masamichi

    2017-10-01

    Pulsed-field gel electrophoresis is a frequent technique used to separate exceptionally large DNA fragments. In a typical continuous field electrophoresis, it is challenging to separate DNA fragments larger than 20 kbp because they migrate at a comparable rate. To overcome this challenge, it is necessary to develop a novel matrix for the electrophoresis. Here, we describe the electrophoresis of large DNA fragments up to 166 kbp using a supramolecular gel matrix and a typical continuous field electrophoresis system. C 3 -symmetric tris-urea self-assembled into a supramolecular hydrogel in tris-boric acid-EDTA buffer, a typical buffer for DNA electrophoresis, and the supramolecular hydrogel was used as a matrix for electrophoresis to separate large DNA fragments. Three types of DNA marker, the λ-Hind III digest (2 to 23 kbp), Lambda DNA-Mono Cut Mix (10 to 49 kbp), and Marker 7 GT (10 to 165 kbp), were analyzed in this study. Large DNA fragments of greater than 100 kbp showed distinct mobility using a typical continuous field electrophoresis system. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Simulations of High Speed Fragment Trajectories

    Science.gov (United States)

    Yeh, Peter; Attaway, Stephen; Arunajatesan, Srinivasan; Fisher, Travis

    2017-11-01

    Flying shrapnel from an explosion are capable of traveling at supersonic speeds and distances much farther than expected due to aerodynamic interactions. Predicting the trajectories and stable tumbling modes of arbitrary shaped fragments is a fundamental problem applicable to range safety calculations, damage assessment, and military technology. Traditional approaches rely on characterizing fragment flight using a single drag coefficient, which may be inaccurate for fragments with large aspect ratios. In our work we develop a procedure to simulate trajectories of arbitrary shaped fragments with higher fidelity using high performance computing. We employ a two-step approach in which the force and moment coefficients are first computed as a function of orientation using compressible computational fluid dynamics. The force and moment data are then input into a six-degree-of-freedom rigid body dynamics solver to integrate trajectories in time. Results of these high fidelity simulations allow us to further understand the flight dynamics and tumbling modes of a single fragment. Furthermore, we use these results to determine the validity and uncertainty of inexpensive methods such as the single drag coefficient model.

  15. Universal Rim Thickness in Unsteady Sheet Fragmentation

    Science.gov (United States)

    Wang, Y.; Dandekar, R.; Bustos, N.; Poulain, S.; Bourouiba, L.

    2018-05-01

    Unsteady fragmentation of a fluid bulk into droplets is important for epidemiology as it governs the transport of pathogens from sneezes and coughs, or from contaminated crops in agriculture. It is also ubiquitous in industrial processes such as paint, coating, and combustion. Unsteady fragmentation is distinct from steady fragmentation on which most theoretical efforts have been focused thus far. We address this gap by studying a canonical unsteady fragmentation process: the breakup from a drop impact on a finite surface where the drop fluid is transferred to a free expanding sheet of time-varying properties and bounded by a rim of time-varying thickness. The continuous rim destabilization selects the final spray droplets, yet this process remains poorly understood. We combine theory with advanced image analysis to study the unsteady rim destabilization. We show that, at all times, the rim thickness is governed by a local instantaneous Bond number equal to unity, defined with the instantaneous, local, unsteady rim acceleration. This criterion is found to be robust and universal for a family of unsteady inviscid fluid sheet fragmentation phenomena, from impacts of drops on various surface geometries to impacts on films. We discuss under which viscous and viscoelastic conditions the criterion continues to govern the unsteady rim thickness.

  16. Large scale meta-analysis of fragment-based screening campaigns: privileged fragments and complementary technologies.

    Science.gov (United States)

    Kutchukian, Peter S; Wassermann, Anne Mai; Lindvall, Mika K; Wright, S Kirk; Ottl, Johannes; Jacob, Jaison; Scheufler, Clemens; Marzinzik, Andreas; Brooijmans, Natasja; Glick, Meir

    2015-06-01

    A first step in fragment-based drug discovery (FBDD) often entails a fragment-based screen (FBS) to identify fragment "hits." However, the integration of conflicting results from orthogonal screens remains a challenge. Here we present a meta-analysis of 35 fragment-based campaigns at Novartis, which employed a generic 1400-fragment library against diverse target families using various biophysical and biochemical techniques. By statistically interrogating the multidimensional FBS data, we sought to investigate three questions: (1) What makes a fragment amenable for FBS? (2) How do hits from different fragment screening technologies and target classes compare with each other? (3) What is the best way to pair FBS assay technologies? In doing so, we identified substructures that were privileged for specific target classes, as well as fragments that were privileged for authentic activity against many targets. We also revealed some of the discrepancies between technologies. Finally, we uncovered a simple rule of thumb in screening strategy: when choosing two technologies for a campaign, pairing a biochemical and biophysical screen tends to yield the greatest coverage of authentic hits. © 2014 Society for Laboratory Automation and Screening.

  17. The dual role of fragments in fragment-assembly methods for de novo protein structure prediction

    Science.gov (United States)

    Handl, Julia; Knowles, Joshua; Vernon, Robert; Baker, David; Lovell, Simon C.

    2013-01-01

    In fragment-assembly techniques for protein structure prediction, models of protein structure are assembled from fragments of known protein structures. This process is typically guided by a knowledge-based energy function and uses a heuristic optimization method. The fragments play two important roles in this process: they define the set of structural parameters available, and they also assume the role of the main variation operators that are used by the optimiser. Previous analysis has typically focused on the first of these roles. In particular, the relationship between local amino acid sequence and local protein structure has been studied by a range of authors. The correlation between the two has been shown to vary with the window length considered, and the results of these analyses have informed directly the choice of fragment length in state-of-the-art prediction techniques. Here, we focus on the second role of fragments and aim to determine the effect of fragment length from an optimization perspective. We use theoretical analyses to reveal how the size and structure of the search space changes as a function of insertion length. Furthermore, empirical analyses are used to explore additional ways in which the size of the fragment insertion influences the search both in a simulation model and for the fragment-assembly technique, Rosetta. PMID:22095594

  18. Lower head failure analysis

    International Nuclear Information System (INIS)

    Rempe, J.L.; Thinnes, G.L.; Allison, C.M.; Cronenberg, A.W.

    1991-01-01

    The US Nuclear Regulatory Commission is sponsoring a lower vessel head research program to investigate plausible modes of reactor vessel failure in order to determine (a) which modes have the greatest likelihood of occurrence during a severe accident and (b) the range of core debris and accident conditions that lead to these failures. This paper presents the methodology and preliminary results of an investigation of reactor designs and thermodynamic conditions using analytic closed-form approximations to assess the important governing parameters in non-dimensional form. Preliminary results illustrate the importance of vessel and tube geometrical parameters, material properties, and external boundary conditions on predicting vessel failure. Thermal analyses indicate that steady-state temperature distributions will occur in the vessel within several hours, although the exact time is dependent upon vessel thickness. In-vessel tube failure is governed by the tube-to-debris mass ratio within the lower head, where most penetrations are predicted to fail if surrounded by molten debris. Melt penetration distance is dependent upon the effective flow diameter of the tube. Molten debris is predicted to penetrate through tubes with a larger effective flow diameter, such as a boiling water reactor (BWR) drain nozzle. Ex-vessel tube failure for depressurized reactor vessels is predicted to be more likely for a BWR drain nozzle penetration because of its larger effective diameter. At high pressures (between ∼0.1 MPa and ∼12 MPa) ex-vessel tube rupture becomes a dominant failure mechanism, although tube ejection dominates control rod guide tube failure at lower temperatures. However, tube ejection and tube rupture predictions are sensitive to the vessel and tube radial gap size and material coefficients of thermal expansion

  19. Phenomenological relation between distribution and fragmentation functions

    International Nuclear Information System (INIS)

    Ma Boqiang; Schmidt, Ivan; Soffer, Jacques; Yang Jianjun

    2002-01-01

    We study the relation between the quark distribution function q(x) and the fragmentation function D q (z) based on a general form D q (x)=C(z)z α q(z) for valence and sea quarks. By adopting two known parametrizations of quark distributions for the proton, we find three simple options for the fragmentation functions that can provide a good description of the available experimental data on proton production in e + e - inelastic annihilation. These three options support the revised Gribov-Lipatov relation D q (z)=zq(z) at z→1, as an approximate relation for the connection between distribution and fragmentation functions. The three options differ in the sea contributions and lead to distinct predictions for antiproton production in the reaction p+p→p-bar+X, thus they are distinguishable in future experiments at RHIC-BNL

  20. Projectile rapidity dependence in target fragmentation

    International Nuclear Information System (INIS)

    Haustein, P.E.; Cumming, J.B.; Hseuh, H.C.

    1979-01-01

    The thick-target, thick-catcher technique was used to determine mean kinetic properties of selected products of the fragmentation of Cu by 1 H, 4 He, and 12 C ions (180 to 28,000 MeV/amu). Momentum transfer, as inferred from F/B ratios, is ovserved to occur most efficiently for the lower velocity projectiles. Recoil properties of target fragments vary strongly with product mass, but show only a weak dependence on projectile type. The projectile's rapidity is shown to be a useful variable for quantitative intercomparison of different reactions. These results indicate that E/sub proj//A/sub proj/ is the dominant parameter which governs the mean recoil behavior of target fragments. 20 references

  1. Antiproton Induced Fission and Fragmentation of Nuclei

    CERN Multimedia

    2002-01-01

    The annihilation of slow antiprotons with nuclei results in a large highly localized energy deposition primarily on the nuclear surface. \\\\ \\\\ The study of antiproton induced fission and fragmentation processes is expected to yield new information on special nuclear matter states, unexplored fission modes, multifragmentation of nuclei, and intranuclear cascades.\\\\ \\\\ In order to investigate the antiproton-nucleus interaction and the processes following the antiproton annihilation at the nucleus, we propose the following experiments: \\item A)~Measurement of several fragments from fission and from multifragmentation in coincidence with particle spectra, especially neutrons and kaons. \\item B)~Precise spectra of $\\pi$, K, n, p, d and t with time-of-flight techniques. \\item C)~Installation of the Berlin 4$\\pi$ neutron detector with a 4$\\pi$ Si detector placed inside for fragments and charged particles. This yields neutron multiplicity distributions and consequently distributions of thermal excitation energies and...

  2. Fragmentation in central collisions of heavy systems

    International Nuclear Information System (INIS)

    Claesson, G.; Doss, K.G.R.; Ferguson, R.

    1987-01-01

    One of the goals of heavy ion reaction studies is to understand the fragmentation of hot nuclei. The LBL/GSI Plastic Ball detector system has been used to achieve a very high solid angle for detection of light and medium-heavy fragments emitted in 200 Mev/A Au + Au and Au + Fe reactions. The simultaneous measurement of almost all of the nucleons and nuclei resulting from each collision allows an estimation of the total charged particle multiplicity and hence the impact parameter. By choosing subsets of the data corresponding to a peripheral or central collision, the assumptions inherent in various models of nuclear fragmentation can be tested. 3 refs., 3 figs

  3. Experiences in fragment-based drug discovery.

    Science.gov (United States)

    Murray, Christopher W; Verdonk, Marcel L; Rees, David C

    2012-05-01

    Fragment-based drug discovery (FBDD) has become established in both industry and academia as an alternative approach to high-throughput screening for the generation of chemical leads for drug targets. In FBDD, specialised detection methods are used to identify small chemical compounds (fragments) that bind to the drug target, and structural biology is usually employed to establish their binding mode and to facilitate their optimisation. In this article, we present three recent and successful case histories in FBDD. We then re-examine the key concepts and challenges of FBDD with particular emphasis on recent literature and our own experience from a substantial number of FBDD applications. Our opinion is that careful application of FBDD is living up to its promise of delivering high quality leads with good physical properties and that in future many drug molecules will be derived from fragment-based approaches. Copyright © 2012 Elsevier Ltd. All rights reserved.

  4. The Injured Body: Humiliation and Fragmentation

    Directory of Open Access Journals (Sweden)

    Graciela Mayet

    2017-03-01

    Full Text Available Simone de Beauvoir’s nouvelles and Titus Andronicus by Shakespeare present us opposite and complementary corporeal nature. In the first case, two women about their sixties are in front of the personal drama of their lost which happen through the years of ageing. It is a kind of fragmentation of existence. Ageing is the most authentic state of the human condition because the human being can only hang on to himself. In Titus Andronicus, are shown mutilations, murderers as fragmentation of biological body and social body. Individualism of modernity doesn’t forgive the bodies deteriorated by the years. In the early modernity, in the times of Elizabeth the First, like in the Ancient Rome, it wasn’t spared humiliations and violence towards the enemy body in order to impose power and authority. In this Shakespeare’s play, the fragmentation of the other’s body and murder are the emergence of social and individual violence.

  5. Analysis of fission-fragment mass distribution within the quantum-mechanical fragmentation theory

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Pardeep; Kaur, Harjeet [Guru Nanak Dev University, Department of Physics, Amritsar (India)

    2016-11-15

    The fission-fragment mass distribution is analysed for the {sup 208}Pb({sup 18}O, f) reaction within the quantum-mechanical fragmentation theory (QMFT). The reaction potential has been calculated by taking the binding energies, Coulomb potential and proximity potential of all possible decay channels and a stationary Schroedinger equation has been solved numerically to calculate the fission-fragment yield. The overall results for mass distribution are compared with those obtained in experiment. Fine structure dips in yield, corresponding to fragment shell closures at Z = 50 and N=82, which are observed by Bogachev et al., are reproduced successfully in the present calculations. These calculations will help to estimate the formation probabilities of fission fragments and to understand many related phenomena occurring in the fission process. (orig.)

  6. Assessment of fragment projection hazard: probability distributions for the initial direction of fragments.

    Science.gov (United States)

    Tugnoli, Alessandro; Gubinelli, Gianfilippo; Landucci, Gabriele; Cozzani, Valerio

    2014-08-30

    The evaluation of the initial direction and velocity of the fragments generated in the fragmentation of a vessel due to internal pressure is an important information in the assessment of damage caused by fragments, in particular within the quantitative risk assessment (QRA) of chemical and process plants. In the present study an approach is proposed to the identification and validation of probability density functions (pdfs) for the initial direction of the fragments. A detailed review of a large number of past accidents provided the background information for the validation procedure. A specific method was developed for the validation of the proposed pdfs. Validated pdfs were obtained for both the vertical and horizontal angles of projection and for the initial velocity of the fragments. Copyright © 2014 Elsevier B.V. All rights reserved.

  7. Dependent failures of diesel generators

    International Nuclear Information System (INIS)

    Mankamo, T.; Pulkkinen, U.

    1982-01-01

    This survey of dependent failures (common-cause failures) is based on the data of diesel generator failures in U. S. nuclear power plants as reported in Licensee Event Reports. Failures were classified into random and potentially dependent failures. All failures due to design errors, manufacturing or installation errors, maintenance errors, or deviations in the operational environment were classified as potentially dependent failures.The statistical dependence between failures was estimated from the relative portion of multiple failures. Results confirm the earlier view of the significance of statistical dependence, a strong dependence on the age of the diesel generator was found in each failure class excluding random failures and maintenance errors, which had a nearly constant frequency independent of diesel generator age

  8. HIERARCHICAL FRAGMENTATION OF THE ORION MOLECULAR FILAMENTS

    International Nuclear Information System (INIS)

    Takahashi, Satoko; Ho, Paul T. P.; Su, Yu-Nung; Teixeira, Paula S.; Zapata, Luis A.

    2013-01-01

    We present a high angular resolution map of the 850 μm continuum emission of the Orion Molecular Cloud-3 (OMC 3) obtained with the Submillimeter Array (SMA); the map is a mosaic of 85 pointings covering an approximate area of 6.'5 × 2.'0 (0.88 × 0.27 pc). We detect 12 spatially resolved continuum sources, each with an H 2 mass between 0.3-5.7 M ☉ and a projected source size between 1400-8200 AU. All the detected sources are on the filamentary main ridge (n H 2 ≥10 6 cm –3 ), and analysis based on the Jeans theorem suggests that they are most likely gravitationally unstable. Comparison of multi-wavelength data sets indicates that of the continuum sources, 6/12 (50%) are associated with molecular outflows, 8/12 (67%) are associated with infrared sources, and 3/12 (25%) are associated with ionized jets. The evolutionary status of these sources ranges from prestellar cores to protostar phase, confirming that OMC-3 is an active region with ongoing embedded star formation. We detect quasi-periodical separations between the OMC-3 sources of ≈17''/0.035 pc. This spatial distribution is part of a large hierarchical structure that also includes fragmentation scales of giant molecular cloud (≈35 pc), large-scale clumps (≈1.3 pc), and small-scale clumps (≈0.3 pc), suggesting that hierarchical fragmentation operates within the Orion A molecular cloud. The fragmentation spacings are roughly consistent with the thermal fragmentation length in large-scale clumps, while for small-scale cores it is smaller than the local fragmentation length. These smaller spacings observed with the SMA can be explained by either a helical magnetic field, cloud rotation, or/and global filament collapse. Finally, possible evidence for sequential fragmentation is suggested in the northern part of the OMC-3 filament.

  9. Dynamical effects in the Colomb expansion following nuclear fragmentation

    International Nuclear Information System (INIS)

    Chung, K.C.; Donangelo, R.J.; Schechter, H.

    1987-01-01

    The effects of the Colomb expansion on the fragment Kinetic energy spectrum for a fragmentating hot nuclear system is investigated. In particular, 12 C fragment spectra are calculated and compared with those predicted by the uniform expansion approximation. The results indicate that energy spectra of fragments are quite sensitive to the details of the Coulomb expansion treatment. (Author) [pt

  10. Detection of fission fragments by secondary emission; Detection des fragments de fission par emission secondaire

    Energy Technology Data Exchange (ETDEWEB)

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

    1965-07-01

    This fission fragment detecting apparatus is based on the principle that fragments traversing a thin foil will cause emission of secondary electrons. These electrons are then accelerated (10 kV) and directly detected by means of a plastic scintillator and associated photomultiplier. Some of the advantages of such a detector are, its rapidity, its discriminating power between alpha particles and fission fragments, its small energy loss in detecting the fragments and the relatively great amount of fissionable material which it can contain. This paper is subdivided as follows: a) theoretical considerations b) constructional details of apparatus and some experimental details and c) a study of the secondary emission effect itself. (author) [French] Le detecteur de fragments de fission que nous avons realise est base sur le principe de l'emission secondaire produite par les fragments de fission traversant une feuille mince: les electrons secondaires emis sont acceleres a des tensions telles (de l'ordre de 10 kV), qu'ils soient directement detectables par un scintillateur plastique associe a un photomultiplicateur. L'interet d'un tel detecteur reside: dans sa rapidite, sa tres bonne discrimination alpha, fission, la possibilite de detecter les fragments de fission avec une perte d'energie pouvant rester relativement faible, et la possibilite d'introduire des quantites de matiere fissile plus importantes que dans les autres types de detecteurs. Ce travail comporte: -) un apercu bibliographique de la theorie du phenomene, -) realisation et mise au point du detecteur avec etude experimentale de quelques parametres intervenant dans l'emission secondaire, -) etude de l'emission secondaire (sur la face d'emergence des fragments de fission) en fonction de l'energie du fragment et en fonction de l'epaisseur de matiere traversee avant emission secondaire, et -) une etude comparative de l'emission secondaire sur la face d'incidence et sur la face d'emergence des fragments de

  11. Dynamics and instabilities in nuclear fragmentation

    International Nuclear Information System (INIS)

    Colonna, M.; Guarnera, A.; Di Toro, M.; Latora, V.; Smerzi, A.; Catania Univ.

    1993-01-01

    A general procedure to identify instability regions which lead to multifragmentation events is presented. The method covers all possible sources of dynamical instabilities. Informations on the instability point, like the time when the nuclear system enters the critical region, the most unstable modes and the time constant of the exponential growing of the relative variances, are deduced without any numerical bias. Important memory effects in the fragmentation pattern are revealed. Some hints towards a fully dynamical picture of fragmentation processes are finally suggested. (author) 7 refs., 3 figs

  12. Parton Propagation and Fragmentation in QCD Matter

    Energy Technology Data Exchange (ETDEWEB)

    Alberto Accardi, Francois Arleo, William Brooks, David D' Enterria, Valeria Muccifora

    2009-12-01

    We review recent progress in the study of parton propagation, interaction and fragmentation in both cold and hot strongly interacting matter. Experimental highlights on high-energy hadron production in deep inelastic lepton-nucleus scattering, proton-nucleus and heavy-ion collisions, as well as Drell-Yan processes in hadron-nucleus collisions are presented. The existing theoretical frameworks for describing the in-medium interaction of energetic partons and the space-time evolution of their fragmentation into hadrons are discussed and confronted to experimental data. We conclude with a list of theoretical and experimental open issues, and a brief description of future relevant experiments and facilities.

  13. Rotating bubble and toroidal nuclei and fragmentation

    International Nuclear Information System (INIS)

    Royer, G.; Haddad, F.; Jouault, B.

    1995-01-01

    The energy of rotating bubble and toroidal nuclei predicted to be formed in central heavy-ion collisions at intermediate energies is calculated within the generalized rotating liquid drop model. The potential barriers standing in these exotic deformation paths are compared with the three dimensional and plane fragmentation barriers. In the toroidal deformation path of the heaviest systems exists a large potential pocket localised below the plane fragmentation barriers. This might allow the temporary survival of heavy nuclear toroids before the final clusterization induced by the surface and proximity tension. (author)

  14. Complejo Ojosmin: fragment of ophiolite transamazonian

    International Nuclear Information System (INIS)

    Bossi, J.; Pineyro, D. . Email geologia@fagro.edu.uy

    2004-01-01

    A preliminary geological survey of a previously unknown basic igneous complex in the Padre Alta Terrane (Pat) is presented. We report petrographic, geochemical and stratigraphic data for more than 200 outcrops. Geological evolution of the complex can be described in terms of four main events: (1) formation Pat units around 2000 Ma; (2) granodiorite thrusting onto possible ophiolite ca 1900 Ma ; (3) granophyric magmatism around 1700 Ma(4) intrusion of trachyte dykes. Data available suggest thrusting onto fragment of oceanic crust. Since the described structure presupposes the existence of pre transamazonian continental fragments in the TPA, it is very important to study the area in detail in the future [es

  15. Radio Frequency Fragment Separator at NSCL

    International Nuclear Information System (INIS)

    Bazin, D.; Andreev, V.; Becerril, A.; Doleans, M.; Mantica, P.F.; Ottarson, J.; Schatz, H.; Stoker, J.B.; Vincent, J.

    2009-01-01

    A new device has been designed and built at NSCL which provides additional filtering of radioactive beams produced via projectile fragmentation. The Radio Frequency Fragment Separator (RFFS) uses the time micro structure of the beams accelerated by the cyclotrons to deflect particles according to their time-of-flight, in effect producing a phase filtering. The transverse RF (Radio Frequency) electric field of the RFFS has superior filtering performance compared to other electrostatic devices, such as Wien filters. Such filtering is critical for radioactive beams produced on the neutron-deficient side of the valley of stability, where strong contamination occurs at intermediate energies from 50 to 200 MeV/u.

  16. Experimental Investigation of the Influence of Confining Stress on Hard Rock Fragmentation Using a Conical Pick

    Science.gov (United States)

    Li, Xibing; Wang, Shaofeng; Wang, Shanyong

    2018-01-01

    High geostress is a prominent condition in deep excavations and affects the cuttability of deep hard rock. This study aims to determine the influence of confining stress on hard rock fragmentation as applied by a conical pick. Using a true triaxial test apparatus, static and coupled static and dynamic loadings from pick forces were applied to end faces of cubic rock specimens to break them under biaxial, uniaxial and stress-free confining stress conditions. The cuttability indices (peak pick force, insertion depth and disturbance duration), failure patterns and fragment sizes were measured and compared to estimate the effects of confining stress. The results show that the rock cuttabilities decreased in order from rock breakages under stress-free conditions to uniaxial confining stress and then to biaxial confining stress. Under biaxial confining stress, only flake-shaped fragments were stripped from the rock surfaces under the requirements of large pick forces or disturbance durations. As the level of uniaxial confining stress increased, the peak pick force and the insertion depth initially increased and then decreased, and the failure patterns varied from splitting to partial splitting and then to rock bursts with decreasing average fragment sizes. Rock bursts will occur under elastic compression via ultra-high uniaxial confining stresses. There are two critical uniaxial confining stress levels, namely stress values at which peak pick forces begin to decrease and improve rock cuttability, and those at which rock bursts initially occur and cutting safety decreases. In particular, hard rock is easiest to split safely and efficiently under stress-free conditions. Moreover, coupled static preloading and dynamic disturbance can increase the efficiency of rock fragmentation with increasing preloading levels and disturbance amplitudes. The concluding remarks confirm hard rock cuttability using conical pick, which can improve the applicability of mechanical excavation in

  17. Nutrition in Heart Failure

    Directory of Open Access Journals (Sweden)

    Reci Meseri

    2013-10-01

    Full Text Available Heart failure is defined as decreased ability of heart due to various reasons. It%u2019s seen 2-3% but the prevalence increases sharply after the age of seventy. The objectives of nutrition therapy in heart failure are to prevent from water retention and edema, to avoid from hard digestion and to offer a balanced diet. In order to avoid fluid retention and edema, daily sodium and fluid intake must be monitored carefully. Main dilemma of the heart failure patients is the obesity-cachexia dilemma. Since one of the main reasons of heart failure is cardiovascular diseases, in first phase, the patient may be obese. In the later phases, cachexia may show up. It was shown that cachexia is associated with mortality. Within this period, patients should not be over-fed and the patient should pass from catabolic state to anabolic state slowly. If the gastrointestinal track is functional oral/enteral feeding must be preferred. Multi vitamin and mineral supportsmay be beneficial, which may replace the increased loss, increase anti-inflammatory response and be anti-oxidants. Large, controlled and well-designed studies must be conducted in order to evaluate the benefits of nutritional practices such as nutritional assessment, enteral feeding and nutrient supports in heart failure patients.

  18. The Zero-Degree Detector system for fragmentation studies

    International Nuclear Information System (INIS)

    Adams, J.H.; Christl, M.J.; Howell, L.W.; Kuznetsov, E.

    2007-01-01

    The measurement of nuclear fragmentation cross-sections requires the detection and identification of individual projectile fragments. If light and heavy fragments are recorded in the same detector, it may be impossible to distinguish the signal from the light fragment. To overcome this problem, we have developed the Zero-degree Detector System (ZDDS). The ZDDS enables the measurement of cross-sections for light fragment production by using pixelated detectors to separately measure the signals of each fragment. The system has been used to measure the fragmentation of beams as heavy as Fe at the NASA Space Radiation Laboratory at Brookhaven National Laboratory and the Heavy Ion Medical Accelerator in Chiba, Japan

  19. Ductile failure modeling

    DEFF Research Database (Denmark)

    Benzerga, Ahmed Amine; Leblond, Jean Baptiste; Needleman, Alan

    2016-01-01

    Ductile fracture of structural metals occurs mainly by the nucleation, growth and coalescence of voids. Here an overview of continuum models for this type of failure is given. The most widely used current framework is described and its limitations discussed. Much work has focused on extending void...... growth models to account for non-spherical initial void shapes and for shape changes during growth. This includes cases of very low stress triaxiality, where the voids can close up to micro-cracks during the failure process. The void growth models have also been extended to consider the effect of plastic...... anisotropy, or the influence of nonlocal effects that bring a material size scale into the models. Often the voids are not present in the material from the beginning, and realistic nucleation models are important. The final failure process by coalescence of neighboring voids is an issue that has been given...

  20. Modeling Epidemic Network Failures

    DEFF Research Database (Denmark)

    Ruepp, Sarah Renée; Fagertun, Anna Manolova

    2013-01-01

    This paper presents the implementation of a failure propagation model for transport networks when multiple failures occur resulting in an epidemic. We model the Susceptible Infected Disabled (SID) epidemic model and validate it by comparing it to analytical solutions. Furthermore, we evaluate...... the SID model’s behavior and impact on the network performance, as well as the severity of the infection spreading. The simulations are carried out in OPNET Modeler. The model provides an important input to epidemic connection recovery mechanisms, and can due to its flexibility and versatility be used...... to evaluate multiple epidemic scenarios in various network types....

  1. Echo and heart failure

    DEFF Research Database (Denmark)

    Modin, Daniel; Andersen, Ditte Madsen; Biering-Sørensen, Tor

    2018-01-01

    Heart failure (HF) is a threat to public health. Heterogeneities in aetiology and phenotype complicate the diagnosis and management of HF. This is especially true when considering HF with preserved ejection fraction (HFpEF), which makes up 50% of HF cases. Natriuretic peptides may aid in establis......Heart failure (HF) is a threat to public health. Heterogeneities in aetiology and phenotype complicate the diagnosis and management of HF. This is especially true when considering HF with preserved ejection fraction (HFpEF), which makes up 50% of HF cases. Natriuretic peptides may aid...

  2. Generalized Block Failure

    DEFF Research Database (Denmark)

    Jönsson, Jeppe

    2015-01-01

    Block tearing is considered in several codes as a pure block tension or a pure block shear failure mechanism. However in many situations the load acts eccentrically and involves the transfer of a substantial moment in combination with the shear force and perhaps a normal force. A literature study...... shows that no readily available tests with a well-defined substantial eccentricity have been performed. This paper presents theoretical and experimental work leading towards generalized block failure capacity methods. Simple combination of normal force, shear force and moment stress distributions along...... yield lines around the block leads to simple interaction formulas similar to other interaction formulas in the codes....

  3. Melt Fragmentation Characteristics of Metal Fuel with Melt Injection Mass during Initiating Phase of SFR Severe Accidents

    Energy Technology Data Exchange (ETDEWEB)

    Heo, Hyo; Lee, Min Ho; Bang, In Cheol [Ulsan National Institute of Science and Technology, Ulsan (Korea, Republic of); Jerng, Dong Wook [Chung-Ang Univ., Seoul (Korea, Republic of)

    2016-05-15

    The PGSFR has adopted the metal fuel for its inherent safety under severe accident conditions. However, this fuel type is not demonstrated clearly yet under the such severe accident conditions. Additional experiments for examining these issues should be performed to support its licensing activities. Under initiating phase of hypothetic core disruptive accident (HCDA) conditions, the molten metal could be better dispersed and fragmented into the coolant channel than in the case of using oxide fuel. This safety strategy provides negative reactivity driven by a good dispersion of melt. If the coolant channel does not sufficient coolability, the severe recriticality would occur within the core region. Thus, it is important to examine the extent of melt fragmentation. The fragmentation behaviors of melt are closely related to a formation of debris shape. Once the debris shape is formed through the fragmentation process, its coolability is determined by the porosity or thermal conductivity of the melt. There were very limited studies for transient irradiation experiments of the metal fuel. These studies were performed by Transient Reactor Test Facility (TREAT) M series tests in U.S. The TREAT M series tests provided basic information of metal fuel performance under transient conditions. The effect of melt injection mass was evaluated in terms of the fragmentation behaviors of melt. These behaviors seemed to be similar between single-pin and multi-pins failure condition. However, the more melt was agglomerated in case of multi-pins failure.

  4. Effective Fragment Potential Method for H-Bonding: How To Obtain Parameters for Nonrigid Fragments.

    Science.gov (United States)

    Dubinets, Nikita; Slipchenko, Lyudmila V

    2017-07-20

    Accuracy of the effective fragment potential (EFP) method was explored for describing intermolecular interaction energies in three dimers with strong H-bonded interactions, formic acid, formamide, and formamidine dimers, which are a part of HBC6 database of noncovalent interactions. Monomer geometries in these dimers change significantly as a function of intermonomer separation. Several EFP schemes were considered, in which fragment parameters were prepared for a fragment in its gas-phase geometry or recomputed for each unique fragment geometry. Additionally, a scheme in which gas-phase fragment parameters are shifted according to relaxed fragment geometries is introduced and tested. EFP data are compared against the coupled cluster with single, double, and perturbative triple excitations (CCSD(T)) method in a complete basis set (CBS) and the symmetry adapted perturbation theory (SAPT). All considered EFP schemes provide a good agreement with CCSD(T)/CBS for binding energies at equilibrium separations, with discrepancies not exceeding 2 kcal/mol. However, only the schemes that utilize relaxed fragment geometries remain qualitatively correct at shorter than equilibrium intermolecular distances. The EFP scheme with shifted parameters behaves quantitatively similar to the scheme in which parameters are recomputed for each monomer geometry and thus is recommended as a computationally efficient approach for large-scale EFP simulations of flexible systems.

  5. Fragment informatics and computational fragment-based drug design: an overview and update.

    Science.gov (United States)

    Sheng, Chunquan; Zhang, Wannian

    2013-05-01

    Fragment-based drug design (FBDD) is a promising approach for the discovery and optimization of lead compounds. Despite its successes, FBDD also faces some internal limitations and challenges. FBDD requires a high quality of target protein and good solubility of fragments. Biophysical techniques for fragment screening necessitate expensive detection equipment and the strategies for evolving fragment hits to leads remain to be improved. Regardless, FBDD is necessary for investigating larger chemical space and can be applied to challenging biological targets. In this scenario, cheminformatics and computational chemistry can be used as alternative approaches that can significantly improve the efficiency and success rate of lead discovery and optimization. Cheminformatics and computational tools assist FBDD in a very flexible manner. Computational FBDD can be used independently or in parallel with experimental FBDD for efficiently generating and optimizing leads. Computational FBDD can also be integrated into each step of experimental FBDD and help to play a synergistic role by maximizing its performance. This review will provide critical analysis of the complementarity between computational and experimental FBDD and highlight recent advances in new algorithms and successful examples of their applications. In particular, fragment-based cheminformatics tools, high-throughput fragment docking, and fragment-based de novo drug design will provide the focus of this review. We will also discuss the advantages and limitations of different methods and the trends in new developments that should inspire future research. © 2012 Wiley Periodicals, Inc.

  6. Relationships between Liquid Atomization and Solid Fragmentation

    Science.gov (United States)

    2016-03-01

    1 2. Basic Definitions ...expressions for average fragment sizes. These observations are surprising, given the fundamental phenomenological differences between liquid and solid...smaller children droplets in the secondary stage. The basic phenomenology of the second stage is much the same as that of the first stage. For

  7. Modelling of the PELE fragmentation dynamics

    Science.gov (United States)

    Verreault, J.

    2014-05-01

    The Penetrator with Enhanced Lateral Effect (PELE) is a type of explosive-free projectile that undergoes radial fragmentation upon an impact with a target plate. This type of projectile is composed of a brittle cylindrical shell (the jacket) filled in its core with a material characterized with a large Poisson's ratio. Upon an impact with a target, the axial compression causes the filling to expand in the radial direction. However, due to the brittleness of the jacket material, very little radial deformation can occur which creates a radial stress between the two materials and a hoop stress in the jacket. Fragmentation of the jacket occurs if the hoop stress exceeds the material's ultimate stress. The PELE fragmentation dynamics is explored via Finite-Element Method (FEM) simulations using the Autodyn explicit dynamics hydrocode. The numerical results are compared with an analytical model based on wave interactions, as well as with the experimental investigation of Paulus and Schirm (1996). The comparison is based on the mechanical stress in the filling and the qualitative fragmentation of the jacket.

  8. Modelling of the PELE fragmentation dynamics

    NARCIS (Netherlands)

    Verreault, J.

    2014-01-01

    The Penetrator with Enhanced Lateral Effect (PELE) is a type of explosive-free projectile that undergoes radial fragmentation upon an impact with a target plate. This type of projectile is composed of a brittle cylindrical shell (the jacket) filled in its core with a material characterized with a

  9. Modelling of the PELE fragmentation dynamics

    International Nuclear Information System (INIS)

    Verreault, J

    2014-01-01

    The Penetrator with Enhanced Lateral Effect (PELE) is a type of explosive-free projectile that undergoes radial fragmentation upon an impact with a target plate. This type of projectile is composed of a brittle cylindrical shell (the jacket) filled in its core with a material characterized with a large Poisson's ratio. Upon an impact with a target, the axial compression causes the filling to expand in the radial direction. However, due to the brittleness of the jacket material, very little radial deformation can occur which creates a radial stress between the two materials and a hoop stress in the jacket. Fragmentation of the jacket occurs if the hoop stress exceeds the material's ultimate stress. The PELE fragmentation dynamics is explored via Finite-Element Method (FEM) simulations using the Autodyn explicit dynamics hydrocode. The numerical results are compared with an analytical model based on wave interactions, as well as with the experimental investigation of Paulus and Schirm (1996). The comparison is based on the mechanical stress in the filling and the qualitative fragmentation of the jacket.

  10. Diquark fragmentation in leptoproduction of hadrons

    International Nuclear Information System (INIS)

    Beavis, D.; Desai, B.R.

    1981-08-01

    In the analysis of the leptoproduction data for the charge ratios of hadrons, the Sukhatme, Lassila and Orava (SLO) model for diquark fragmentation is shown to be consistent with the hypothesis of a diquark acting as a single unit. The baryon contribution to the charge ratio, ignored earlier by SLO, makes a significant effect. (author)

  11. Heavy Flavor Fragmentation and Decay at SLD

    Energy Technology Data Exchange (ETDEWEB)

    Plano, Richard M

    1999-02-24

    Results on heavy quark fragmentation obtained using the SLD detector at the SLAC Linear Collider are presented. This talk will cover the ratio of vector to pseudoscalar charmed meson production, the inclusive B hadron energy distribution, the inclusive particle production in heavy jets compared to their production in light jets, and charged and neutral B meson lifetimes.

  12. Probabilistic Role Models and the Guarded Fragment

    DEFF Research Database (Denmark)

    Jaeger, Manfred

    2004-01-01

    We propose a uniform semantic framework for interpreting probabilistic concept subsumption and probabilistic role quantification through statistical sampling distributions. This general semantic principle serves as the foundation for the development of a probabilistic version of the guarded fragm...... fragment of first-order logic. A characterization of equivalence in that logic in terms of bisimulations is given....

  13. Probabilistic role models and the guarded fragment

    DEFF Research Database (Denmark)

    Jaeger, Manfred

    2006-01-01

    We propose a uniform semantic framework for interpreting probabilistic concept subsumption and probabilistic role quantification through statistical sampling distributions. This general semantic principle serves as the foundation for the development of a probabilistic version of the guarded fragm...... fragment of first-order logic. A characterization of equivalence in that logic in terms of bisimulations is given....

  14. OSCILLATING FILAMENTS. I. OSCILLATION AND GEOMETRICAL FRAGMENTATION

    Energy Technology Data Exchange (ETDEWEB)

    Gritschneder, Matthias; Heigl, Stefan; Burkert, Andreas, E-mail: gritschm@usm.uni-muenchen.de [University Observatory Munich, LMU Munich, Scheinerstrasse 1, D-81679 Munich (Germany)

    2017-01-10

    We study the stability of filaments in equilibrium between gravity and internal as well as external pressure using the grid-based AMR code RAMSES. A homogeneous, straight cylinder below a critical line mass is marginally stable. However, if the cylinder is bent, such as with a slight sinusoidal perturbation, an otherwise stable configuration starts to oscillate, is triggered into fragmentation, and collapses. This previously unstudied behavior allows a filament to fragment at any given scale, as long as it has slight bends. We call this process “geometrical fragmentation.” In our realization, the spacing between the cores matches the wavelength of the sinusoidal perturbation, whereas up to now, filaments were thought to be only fragmenting on the characteristic scale set by the mass-to-line ratio. Using first principles, we derive the oscillation period as well as the collapse timescale analytically. To enable a direct comparison with observations, we study the line-of-sight velocity for different inclinations. We show that the overall oscillation pattern can hide the infall signature of cores.

  15. Continuous fragment of the mu-calculus

    NARCIS (Netherlands)

    Fontaine, G.

    2008-01-01

    In this paper we investigate the Scott continuous fragment of the modal μ-calculus. We discuss its relation with constructivity, where we call a formula constructive if its least fixpoint is always reached in at most ω steps. Our main result is a syntactic characterization of this continuous

  16. Fragmentation of forest, grassland, and shrubland

    Science.gov (United States)

    Kurt H. Riitters

    2013-01-01

    As humans introduce competing land uses into natural landscapes, the public concerns regarding landcover patterns are expressed through headline issues such as urban sprawl, forest fragmentation, water quality, and wilderness preservation. The spatial arrangement of an environment affects all human perceptions and ecological processes within that environment, but this...

  17. Metagenome Fragment Classification Using -Mer Frequency Profiles

    Directory of Open Access Journals (Sweden)

    Gail Rosen

    2008-01-01

    Full Text Available A vast amount of microbial sequencing data is being generated through large-scale projects in ecology, agriculture, and human health. Efficient high-throughput methods are needed to analyze the mass amounts of metagenomic data, all DNA present in an environmental sample. A major obstacle in metagenomics is the inability to obtain accuracy using technology that yields short reads. We construct the unique -mer frequency profiles of 635 microbial genomes publicly available as of February 2008. These profiles are used to train a naive Bayes classifier (NBC that can be used to identify the genome of any fragment. We show that our method is comparable to BLAST for small 25 bp fragments but does not have the ambiguity of BLAST's tied top scores. We demonstrate that this approach is scalable to identify any fragment from hundreds of genomes. It also performs quite well at the strain, species, and genera levels and achieves strain resolution despite classifying ubiquitous genomic fragments (gene and nongene regions. Cross-validation analysis demonstrates that species-accuracy achieves 90% for highly-represented species containing an average of 8 strains. We demonstrate that such a tool can be used on the Sargasso Sea dataset, and our analysis shows that NBC can be further enhanced.

  18. Intraday Price Discovery in Fragmented Markets

    NARCIS (Netherlands)

    S.R. Ozturk (Sait); M. van der Wel (Michel); D.J.C. van Dijk (Dick)

    2014-01-01

    textabstractFor many assets, trading is fragmented across multiple exchanges. Price discovery measures summarize the informativeness of trading on each venue for discovering the asset’s true underlying value. We explore intraday variation in price discovery using a structural model with

  19. Targeting incentives to reduce habitat fragmentation

    Science.gov (United States)

    David Lewis; Andrew Plantinga; Junjie Wu

    2009-01-01

    This article develops a theoretical model to analyze the spatial targeting of incentives for the restoration of forested landscapes when wildlife habitat can be enhanced by reducing fragmentation. The key theoretical result is that the marginal net benefits of increasing forest can be convex, in which case corner solutions--converting either none or all of the...

  20. Fragmentation and structure of silicon microclusters

    International Nuclear Information System (INIS)

    Feuston, B.P.; Kalia, R.K.; Vashishta, P.

    1987-01-01

    It may be possible to determine the magic numbers and fragmentation spectra from the ground-state binding energies and structure, but the relationship between the lowest-energy zero-temperature configurations and the energetics of finite-temperature microclusters is not obvious. Recall fragmentation of Si clusters occurs at temperatures the order of the melting temperature (T∼2000 K). What is needed, a first-principles finite-temperature calculation, allowing the determination of all possible structures, their corresponding binding energies, and fragmentation spectra, is not presently possible. However, a molecular dynamics calculation does allow one to study the nature of fragmentation in addition to determination of the global ground-state structure and all mechanically stable configurations underlying the finite-temperature cluster, once given an interaction potential. The authors present results for such a calculation for Si/sub 2-14/ using the Stillinger-Weber 3-body potential. Their results indicate that the existence of magic numbers is determined by the topology and energetics of high-energy bound structures rather than the structure and ground-state energies at zero temperature

  1. Strategic Targeted Advertising and Market Fragmentation

    OpenAIRE

    Lola Esteban; Jose M. Hernandez

    2007-01-01

    This paper proves that oligopolistic price competition with both targeted advertising and targeted prices can lead to a permanent fragmentation of the market into a local monopoly. However, compared to mass advertising, targeting increases social welfare and turns out to be more beneficial for consumers than for firms.

  2. Habitat fragmentation causes rapid genetic differentiation and ...

    African Journals Online (AJOL)

    ... city buildings. These results were supported by multiple statistical analyses including Mantel's test, PCOORDA and AMOVA. Genetic enrichment and epigenetic variation studies can be included in habitat fragmentation analysis and its implications in inducing homogenization and susceptibility in natural plant populations.

  3. Searching Fragment Spaces with feature trees.

    Science.gov (United States)

    Lessel, Uta; Wellenzohn, Bernd; Lilienthal, Markus; Claussen, Holger

    2009-02-01

    Virtual combinatorial chemistry easily produces billions of compounds, for which conventional virtual screening cannot be performed even with the fastest methods available. An efficient solution for such a scenario is the generation of Fragment Spaces, which encode huge numbers of virtual compounds by their fragments/reagents and rules of how to combine them. Similarity-based searches can be performed in such spaces without ever fully enumerating all virtual products. Here we describe the generation of a huge Fragment Space encoding about 5 * 10(11) compounds based on established in-house synthesis protocols for combinatorial libraries, i.e., we encode practically evaluated combinatorial chemistry protocols in a machine readable form, rendering them accessible to in silico search methods. We show how such searches in this Fragment Space can be integrated as a first step in an overall workflow. It reduces the extremely huge number of virtual products by several orders of magnitude so that the resulting list of molecules becomes more manageable for further more elaborated and time-consuming analysis steps. Results of a case study are presented and discussed, which lead to some general conclusions for an efficient expansion of the chemical space to be screened in pharmaceutical companies.

  4. Element Distribution and Multiplicity of Heavy Fragments

    CERN Multimedia

    2002-01-01

    This experiment will measure the energy and angular distribution of heavy fragments produced in the reactions of |1|2C on several targets between |2|7Al and |2|3|8U at 86~MeV/u. The systematic investigation of a highly excited interaction region (fireball) by means of a clean N and Z identification of heavy tar fragments, may result in a better understanding of temperature concept and of the degree of equilibration of the local interaction region with respect to the total system. For this investigation a large-area position sensitive ionization chamber of 50~msr solid angle in conjunction with a time-of-flight telescope consisting of parallel-plate detectors will be used. \\\\ \\\\ In order to get information on the transverse momentum transfer and the inelasticity of the collision, the energy of the PROJECTILE-FRAGMENTS will be measured at forward angles with a plastic scintillator hodoscope. In addition to this inclusive measurement correlations between heavy fragments will be investigated by means of three pos...

  5. Efficient clustering aggregation based on data fragments.

    Science.gov (United States)

    Wu, Ou; Hu, Weiming; Maybank, Stephen J; Zhu, Mingliang; Li, Bing

    2012-06-01

    Clustering aggregation, known as clustering ensembles, has emerged as a powerful technique for combining different clustering results to obtain a single better clustering. Existing clustering aggregation algorithms are applied directly to data points, in what is referred to as the point-based approach. The algorithms are inefficient if the number of data points is large. We define an efficient approach for clustering aggregation based on data fragments. In this fragment-based approach, a data fragment is any subset of the data that is not split by any of the clustering results. To establish the theoretical bases of the proposed approach, we prove that clustering aggregation can be performed directly on data fragments under two widely used goodness measures for clustering aggregation taken from the literature. Three new clustering aggregation algorithms are described. The experimental results obtained using several public data sets show that the new algorithms have lower computational complexity than three well-known existing point-based clustering aggregation algorithms (Agglomerative, Furthest, and LocalSearch); nevertheless, the new algorithms do not sacrifice the accuracy.

  6. Molecular markers. Amplified fragment length polymorphism

    Directory of Open Access Journals (Sweden)

    Pržulj Novo

    2005-01-01

    Full Text Available Amplified Fragment Length Polymorphism molecular markers (AFLPs has been developed combining procedures of RFLPs and RAPDs molekular markers, i.e. the first step is restriction digestion of the genomic DNA that is followed by selective amplification of the restricted fragments. The advantage of the AFLP technique is that it allows rapid generation of a large number of reproducible markers. The reproducibility of AFLPs markers is assured by the use of restriction site-specific adapters and adapter-specific primers for PCR reaction. Only fragments containing the restriction site sequence plus the additional nucleotides will be amplified and the more selected nucleotides added on the primer sequence the fewer the number of fragments amplified by PCR. The amplified products are normally separated on a sequencing gel and visualized after exposure to X-ray film or by using fluorescent labeled primers. AFLP shave proven to be extremely proficient in revealing diversity at below the species level. A disadvantage of AFLP technique is that AFLPs are essentially a dominant marker system and not able to identify heterozygotes.

  7. Albumin modification and fragmentation in renal disease.

    Science.gov (United States)

    Donadio, Carlo; Tognotti, Danika; Donadio, Elena

    2012-02-18

    Albumin is the most important antioxidant substance in plasma and performs many physiological functions. Furthermore, albumin is the major carrier of endogenous molecules and exogenous ligands. This paper reviews the importance of post-translational modifications of albumin and fragments thereof in patients with renal disease. First, current views and controversies on renal handling of proteins, mainly albumin, will be discussed. Post-translational modifications, namely the fragmentation of albumin found with proteomic techniques in nephrotic patients, diabetics, and ESRD patients will be presented and discussed. It is reasonable to hypothesize that proteolytic fragmentation of serum albumin is due to a higher susceptibility to proteases, induced by oxidative stress. The clinical relevance of the fragmentation of albumin has not yet been established. These modifications could affect some physiological functions of albumin and have a patho-physiological role in uremic syndrome. Proteomic analysis of serum allows the identification of over-expressed proteins and can detect post-translational modifications of serum proteins, hitherto hidden, using standard laboratory techniques. Copyright © 2011 Elsevier B.V. All rights reserved.

  8. Quantum properties of QCD string fragmentation

    Directory of Open Access Journals (Sweden)

    Todorova-Nová Šárka

    2016-01-01

    Full Text Available A simple quantization concept for a 3-dim QCD string is used to derive properties of QCD flux tube from the mass spectrum of light mesons and to predict observable quantum effects in correlations between adjacent hadrons. The quantized fragmentation model is presented and compared with experimental observations.

  9. Modeling fragmentation with new high order finite element technology and node splitting

    Directory of Open Access Journals (Sweden)

    Olovsson Lars

    2015-01-01

    Full Text Available The modeling of fragmentation has historically been linked to the weapons industry where the main goal is to optimize a bomb or to design effective blast shields. Numerical modeling of fragmentation from dynamic loading has traditionally been modeled by legacy finite element solvers that rely on element erosion to model material failure. However this method results in the removal of too much material. This is not realistic as retaining the mass of the structure is critical to modeling the event correctly. We propose a new approach implemented in the IMPETUS AFEA SOLVER® based on the following: New High Order Finite Elements that can easily deal with very large deformations; Stochastic distribution of initial damage that allows for a non homogeneous distribution of fragments; and a Node Splitting Algorithm that allows for material fracture without element erosion that is mesh independent. The approach is evaluated for various materials and scenarios: -Titanium ring electromagnetic compression; Hard steel Taylor bar impact, Fused silica Taylor bar impact, Steel cylinder explosion, The results obtained from the simulations are representative of the failure mechanisms observed experimentally. The main benefit of this approach is good energy conservation (no loss of mass and numerical robustness even in complex situations.

  10. Experimental constraints on dynamic fragmentation as a dissipative process during seismic slip.

    Science.gov (United States)

    Barber, Troy; Griffith, W Ashley

    2017-09-28

    Various fault damage fabrics, from gouge in the principal slip zone to fragmented and pulverized rocks in the fault damage zone, have been attributed to brittle deformation at high strain rates during earthquake rupture. Past experimental work has shown that there exists a critical threshold in stress-strain rate space through which rock failure transitions from failure along a few discrete fracture planes to intense fragmentation. We present new experimental results on Arkansas Novaculite (AN) and Westerly Granite (WG) in which we quantify fracture surface area produced by dynamic fragmentation under uniaxial compressive loading and examine the controls of pre-existing mineral anisotropy on dissipative processes at the microscale. Tests on AN produced substantially greater new fracture surface area (approx. 6.0 m 2  g -1 ) than those on WG (0.07 m 2  g -1 ). Estimates of the portion of energy dissipated into brittle fracture were significant for WG (approx. 5%), but appeared substantial in AN (10% to as much as 40%). The results have important implications for the partitioning of dissipated energy under extreme loading conditions expected during earthquakes and the scaling of high-speed laboratory rock mechanics experiments to natural fault zones.This article is part of the themed issue 'Faulting, friction and weakening: from slow to fast motion'. © 2017 The Author(s).

  11. Isogeometric failure analysis

    NARCIS (Netherlands)

    Verhoosel, C.V.; Scott, M.A.; Borden, M.J.; Borst, de R.; Hughes, T.J.R.; Mueller-Hoeppe, D.; Loehnert, S.; Reese, S.

    2011-01-01

    Isogeometric analysis is a versatile tool for failure analysis. On the one hand, the excellent control over the inter-element continuity conditions enables a natural incorporation of continuum constitutive relations that incorporate higher-order strain gradients, as in gradient plasticity or damage.

  12. Beyond Success and Failure

    NARCIS (Netherlands)

    Etalle, Sandro; Jaffar, Joxan; van Raamsdonk, Femke

    We study a new programming framework based on logic programming where success and failure are replaced by predicates for adequacy and inadequacy. Adequacy allows to extract a result from a partial computation, and inadequacy allows to flexibly constrain the search space. In this parameterized

  13. Poverty and Aspirations Failure

    NARCIS (Netherlands)

    Dalton, P.S.; Ghosal, S.; Mani, A.

    2011-01-01

    We develop a theoretical framework to study the psychology of poverty and 'aspirations failure'. In our framework, the rich and the poor share the same preferences - and also a behavioral bias in setting aspirations. Greater downside risks imposed by poverty exacerbates the effects of this

  14. Poverty and aspirations failure

    NARCIS (Netherlands)

    Dalton, P.S.; Ghosal, S.; Mani, A.

    We develop a theoretical framework to study the psychology of poverty and ‘aspirations failure’, defined as the failure to aspire to one’s own potential. In our framework, rich and the poor persons share the same preferences and same behavioral bias in setting aspirations. We show that poverty can

  15. Copeptin in Heart Failure

    DEFF Research Database (Denmark)

    Balling, Louise; Gustafsson, Finn

    2016-01-01

    Heart failure (HF) is one of the most common causes of hospitalization and mortality in the modern Western world and an increasing proportion of the population will be affected by HF in the future. Although HF management has improved quality of life and prognosis, mortality remains very high...

  16. Acute liver failure

    DEFF Research Database (Denmark)

    Bernal, William; Lee, William M; Wendon, Julia

    2015-01-01

    Over the last three decades acute liver failure (ALF) has been transformed from a rare and poorly understood condition with a near universally fatal outcome, to one with a well characterized phenotype and disease course. Complex critical care protocols are now applied and emergency liver...

  17. Premature ovarian failure

    OpenAIRE

    Pacheco, José

    2011-01-01

    Premature ovarian failure is characterized by secondary amenorrhea affecting a woman before the age of 40, leading to hypoestrogenism, infertility, and consequences of premature menopause, such as osteoporosis, cardiovascular disease, neurovegetative alterations, and others. Follicular exhaustion is due to either follicles shortage or oocytes accelerated destruction. Main causes are genetic, autoimmune and iatrogenic. Among genetic causes Xq and Xp deletions, translocations, numeric aberratio...

  18. CMR in Heart Failure.

    OpenAIRE

    Sado, D. M.; Hasleton, J. M.; Herrey, A. S.; Moon, J. C.

    2011-01-01

    Heart Failure (HF) is a common syndrome with multiple causes. Cardiovascular magnetic resonance (CMR) is a medical imaging technique with significant advantages, allowing the understanding of aetiology and pathophysiology of HF in the individual patient, permitting specific therapy to be administered and predicting prognosis. This paper discusses the diverse role of CMR in HF.

  19. Perioperative acute renal failure.

    LENUS (Irish Health Repository)

    Mahon, Padraig

    2012-02-03

    PURPOSE OF REVIEW: Recent biochemical evidence increasingly implicates inflammatory mechanisms as precipitants of acute renal failure. In this review, we detail some of these pathways together with potential new therapeutic targets. RECENT FINDINGS: Neutrophil gelatinase-associated lipocalin appears to be a sensitive, specific and reliable biomarker of renal injury, which may be predictive of renal outcome in the perioperative setting. For estimation of glomerular filtration rate, cystatin C is superior to creatinine. No drug is definitively effective at preventing postoperative renal failure. Clinical trials of fenoldopam and atrial natriuretic peptide are, at best, equivocal. As with pharmacological preconditioning of the heart, volatile anaesthetic agents appear to offer a protective effect to the subsequently ischaemic kidney. SUMMARY: Although a greatly improved understanding of the pathophysiology of acute renal failure has offered even more therapeutic targets, the maintenance of intravascular euvolaemia and perfusion pressure is most effective at preventing new postoperative acute renal failure. In the future, strategies targeting renal regeneration after injury will use bone marrow-derived stem cells and growth factors such as insulin-like growth factor-1.

  20. Tests of models for parton fragmentation in e+e- annihilation

    International Nuclear Information System (INIS)

    Gary, J.W.

    1985-11-01

    We examine the distribution of particles in the three jet events of e + e - annihilation. The data was collected with the PEP-4/Time Projection Chamber detector at 29 GeV center-of-mass energy at PEP. The experimental distributions are compared to the predictions of several fragmentation models which describe the transition of quarks and gluons into hadrons. In particular, our study emphasizes the three fragmentation models which are currently in widest use: the Lund string model, the Webber cluster model and the independent fragmentation model. These three models each possess different Lorentz frame structures for the distribution of hadron sources relative to the overall event c.m. in three jet events. The Lund string and independent fragmentation models are tuned to describe global event properties of our multihadronic annihilation event sample. This tuned Lund string model provides a good description of the distribution of particles between jet axes in three jet events, while the independent fragmentation model does not. We verify that the failure of the independent fragmentation model is not a consequence of parameter tuning or of model variant. The Webber cluster model, which is untuned, does not describe the absolute particle densities between jets but correctly predicts the ratios of those densities, which are less sensitive to the tuning. These results provide evidence that the sources of hadrons are boosted with respect to the overall center-of-mass in three jet events, with components of motion normal to the jet axes. The distribution of particles close to jet axes provides additional support for this conclusion. 94 refs

  1. Fragmentation of molten copper drop caused by entrapment of liquid sodium

    International Nuclear Information System (INIS)

    Abe, N.; Sugiyama, K.; Nishimura, S.; Kinoshita, I.

    2001-01-01

    In core meltdown accidents, it is possible to occur thermal interactions between molten fuel and coolant. Analysis of the steam explosion, which is one of the most severe phenomena in such thermal interactions, is important for the safety evaluation. The steam explosion is a phenomenon that intensive pressure waves are caused by the explosive thermal interaction between high and low temperature liquids, and is considered to be one of the phenomena that can cause a serious failure of the nuclear reactor structures. In a large-scale steam explosion, the fragmentation of hot molten material causes a rapid increase of heat transfer area, and it is achieved to transmit instantaneously a large amount of heat to coolant. Two ideas are chiefly considered as the mechanism of the fragmentation. The one is the hypothesis that hydrodynamic effect causes fragmentation of hot liquid. According to this hypothesis, the high temperature drops flake off from the surface. The other is that fragmentation is caused by the interface instability accompanied by collapse of the steam bubble formed around a hot liquid. In this research, the possibility of the internal fragmentation caused by the coolant jet is focused in. Experiments were conducted on the condition that the surface of melt drops solidify at the moment drops contact the coolant. The possibility of the fragmentation of hot liquid from its surface was eliminated in this condition. To satisfy this condition, molten copper was chosen as hot liquid, and liquid sodium was used as coolant to verify the effect of the driving force of the sodium jet. (author)

  2. Diuretics for heart failure.

    Science.gov (United States)

    Faris, Rajaa F; Flather, Marcus; Purcell, Henry; Poole-Wilson, Philip A; Coats, Andrew J S

    2012-02-15

    Chronic heart failure is a major cause of morbidity and mortality worldwide. Diuretics are regarded as the first-line treatment for patients with congestive heart failure since they provide symptomatic relief. The effects of diuretics on disease progression and survival remain unclear. To assess the harms and benefits of diuretics for chronic heart failure Updated searches were run in the Cochrane Central Register of Controlled Trials in The Cochrane Library (CENTRAL Issue 1 of 4, 2011), MEDLINE (1966 to 22 February 2011), EMBASE (1980 to 2011 Week 07) and HERDIN database (1990 to February 2011). We hand searched pertinent journals and reference lists of papers were inspected. We also contacted manufacturers and researchers in the field. No language restrictions were applied. Double-blinded randomised controlled trials of diuretic therapy comparing one diuretic with placebo, or one diuretic with another active agent (e.g. ACE inhibitors, digoxin) in patients with chronic heart failure. Two authors independently abstracted the data and assessed the eligibility and methodological quality of each trial. Extracted data were analysed by determining the odds ratio for dichotomous data, and difference in means for continuous data, of the treated group compared with controls. The likelihood of heterogeneity of the study population was assessed by the Chi-square test. If there was no evidence of statistical heterogeneity and pooling of results was clinically appropriate, a combined estimate was obtained using the fixed-effects model. This update has not identified any new studies for inclusion. The review includes 14 trials (525 participants), 7 were placebo-controlled, and 7 compared diuretics against other agents such as ACE inhibitors or digoxin. We analysed the data for mortality and for worsening heart failure. Mortality data were available in 3 of the placebo-controlled trials (202 participants). Mortality was lower for participants treated with diuretics than for

  3. Use of biomarkers to guide outpatient therapy of heart failure.

    Science.gov (United States)

    DeBeradinis, Benedetta; Januzzi, James L

    2012-11-01

    Among patients with heart failure, concentrations of natriuretic peptides are strongly linked to the presence and severity of structural heart disease and are strongly prognostic in this setting. Additionally, favorable reduction in the concentration of either B-type natriuretic peptide (BNP) or B-type natriuretic peptide and its amino-terminal cleavage fragment (NT-proBNP) may be seen during treatment of heart failure, with parallel improvement in prognosis. This has led to the hypothesis that intensified treatment directed at reducing natriuretic peptide concentrations may improve outcomes in heart failure. In chronic heart failure, studies suggest that a strategy of standard-of-care management together with a goal to suppress BNP or NT-proBNP concentrations leads to greater application of guideline-derived medical therapy and is well tolerated. In certain studies of this BNP or NT-proBNP 'guided' approach, patients treated with biomarker-guided care had superior outcomes when compared with standard heart failure management alone, particularly in younger study populations, in patients with left ventricular systolic dysfunction, and particularly when substantial reductions in natriuretic peptides were achieved in association with biomarker-guided care. Natriuretic peptide 'guided' management appears promising in patients suffering from chronic heart failure. Large-scale pivotal trials to confirm the approach are planned.

  4. Failure cascade in interdependent network with traffic loads

    International Nuclear Information System (INIS)

    Hong, Sheng; Wang, Baoqing; Wang, Jianghui; Zhao, Tingdi; Ma, Xiaomin

    2015-01-01

    Complex networks have been widely studied recent years, but most researches focus on the single, non-interacting networks. With the development of modern systems, many infrastructure networks are coupled together and therefore should be modeled as interdependent networks. For interdependent networks, failure of nodes in one network may lead to failure of dependent nodes in the other networks. This may happen recursively and lead to a failure cascade. In the real world, different networks carry different traffic loads. Overload and load redistribution may lead to more nodes’ failure. Considering the dependency between the interdependent networks and the traffic load, a small fraction of fault nodes may lead to complete fragmentation of a system. Based on the robust analysis of interdependent networks, we propose a costless defense strategy to suppress the failure cascade. Our findings highlight the need to consider the load and coupling preference when designing robust interdependent networks. And it is necessary to take actions in the early stage of the failure cascade to decrease the losses caused by the large-scale breakdown of infrastructure networks. (paper)

  5. Fragmentation of massive dense cores down to ≲ 1000 AU: Relation between fragmentation and density structure

    International Nuclear Information System (INIS)

    Palau, Aina; Girart, Josep M.; Estalella, Robert; Fuente, Asunción; Fontani, Francesco; Sánchez-Monge, Álvaro; Commerçon, Benoit; Hennebelle, Patrick; Busquet, Gemma; Bontemps, Sylvain; Zapata, Luis A.; Zhang, Qizhou; Di Francesco, James

    2014-01-01

    In order to shed light on the main physical processes controlling fragmentation of massive dense cores, we present a uniform study of the density structure of 19 massive dense cores, selected to be at similar evolutionary stages, for which their relative fragmentation level was assessed in a previous work. We inferred the density structure of the 19 cores through a simultaneous fit of the radial intensity profiles at 450 and 850 μm (or 1.2 mm in two cases) and the spectral energy distribution, assuming spherical symmetry and that the density and temperature of the cores decrease with radius following power-laws. Even though the estimated fragmentation level is strictly speaking a lower limit, its relative value is significant and several trends could be explored with our data. We find a weak (inverse) trend of fragmentation level and density power-law index, with steeper density profiles tending to show lower fragmentation, and vice versa. In addition, we find a trend of fragmentation increasing with density within a given radius, which arises from a combination of flat density profile and high central density and is consistent with Jeans fragmentation. We considered the effects of rotational-to-gravitational energy ratio, non-thermal velocity dispersion, and turbulence mode on the density structure of the cores, and found that compressive turbulence seems to yield higher central densities. Finally, a possible explanation for the origin of cores with concentrated density profiles, which are the cores showing no fragmentation, could be related with a strong magnetic field, consistent with the outcome of radiation magnetohydrodynamic simulations.

  6. Fragmentation of massive dense cores down to ≲ 1000 AU: Relation between fragmentation and density structure

    Energy Technology Data Exchange (ETDEWEB)

    Palau, Aina; Girart, Josep M. [Institut de Ciències de l' Espai (CSIC-IEEC), Campus UAB-Facultat de Ciències, Torre C5-parell 2, E-08193 Bellaterra, Catalunya (Spain); Estalella, Robert [Departament d' Astronomia i Meteorologia (IEEC-UB), Institut de Ciències del Cosmos, Universitat de Barcelona, Martí i Franquès, 1, E-08028 Barcelona (Spain); Fuente, Asunción [Observatorio Astronómico Nacional, P.O. Box 112, E-28803 Alcalá de Henares, Madrid (Spain); Fontani, Francesco; Sánchez-Monge, Álvaro [Osservatorio Astrofisico di Arcetri, INAF, Lago E. Fermi 5, I-50125 Firenze (Italy); Commerçon, Benoit; Hennebelle, Patrick [Laboratoire de Radioastronomie, UMR CNRS 8112, École Normale Supérieure et Observatoire de Paris, 24 rue Lhomond, F-75231 Paris Cedex 05 (France); Busquet, Gemma [INAF-Istituto di Astrofisica e Planetologia Spaziali, Area di Recerca di Tor Vergata, Via Fosso Cavaliere 100, I-00133 Roma (Italy); Bontemps, Sylvain [Université de Bordeaux, LAB, UMR 5804, F-33270 Floirac (France); Zapata, Luis A. [Centro de Radioastronomía y Astrofísica, Universidad Nacional Autónoma de México, P.O. Box 3-72, 58090 Morelia, Michoacán (Mexico); Zhang, Qizhou [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Di Francesco, James, E-mail: palau@ieec.uab.es [Department of Physics and Astronomy, University of Victoria, P.O. Box 355, STN CSC, Victoria, BC, V8W 3P6 (Canada)

    2014-04-10

    In order to shed light on the main physical processes controlling fragmentation of massive dense cores, we present a uniform study of the density structure of 19 massive dense cores, selected to be at similar evolutionary stages, for which their relative fragmentation level was assessed in a previous work. We inferred the density structure of the 19 cores through a simultaneous fit of the radial intensity profiles at 450 and 850 μm (or 1.2 mm in two cases) and the spectral energy distribution, assuming spherical symmetry and that the density and temperature of the cores decrease with radius following power-laws. Even though the estimated fragmentation level is strictly speaking a lower limit, its relative value is significant and several trends could be explored with our data. We find a weak (inverse) trend of fragmentation level and density power-law index, with steeper density profiles tending to show lower fragmentation, and vice versa. In addition, we find a trend of fragmentation increasing with density within a given radius, which arises from a combination of flat density profile and high central density and is consistent with Jeans fragmentation. We considered the effects of rotational-to-gravitational energy ratio, non-thermal velocity dispersion, and turbulence mode on the density structure of the cores, and found that compressive turbulence seems to yield higher central densities. Finally, a possible explanation for the origin of cores with concentrated density profiles, which are the cores showing no fragmentation, could be related with a strong magnetic field, consistent with the outcome of radiation magnetohydrodynamic simulations.

  7. Modeling Fragment Simulating Projectile Penetration into Steel Plates Using Finite Elements and Meshfree Particles

    Directory of Open Access Journals (Sweden)

    James O’Daniel

    2011-01-01

    Full Text Available Simulating fragment penetration into steel involves complicated modeling of severe behavior of the materials through multiple phases of response. Penetration of a fragment-like projectile was simulated using finite element (FE and meshfree particle formulations. Extreme deformation and failure of the material during the penetration event were modeled with several approaches to evaluate each as to how well it represents the actual physics of the material and structural response. A steel Fragment Simulating Projectile (FSP – designed to simulate a fragment of metal from a weapon casing – was simulated for normal impact into a flat square plate. A range of impact velocities was used to examine levels of exit velocity ranging from relatively small to one on the same level as the impact velocity. The numerical code EPIC, used for all the simulations presented herein, contains the element and particle formulations, as well as the explicit methodology and constitutive models needed to perform these simulations. These simulations were compared against experimental data, evaluating the damage caused to the projectile and the target plates, as well as comparing the residual velocity when the projectile perforated the target.

  8. OBSTETRIC RENAL FAILURE

    Directory of Open Access Journals (Sweden)

    Rajeshwari

    2015-11-01

    Full Text Available Renal failure in obstetrics is rare but important complication, associated with significant mortality and long term morbidity.1,2 It includes acute renal failure due to obstetrical complications or due to deterioration of existing renal disease. AIMS AND OBJECTIVES: To evaluate the etiology and outcome of renal failure in obstetric patients. METHODS: We prospectively analyzed 30 pregnant and puerperal women with acute renal failure or pre-existing renal disease developing renal failure during pregnancy between November 2007 to sep-2009. Patients who presented/developed ARF during the hospital stay were included in this study. RESULTS: Among 30 patients, mean age was 23 years and 33 years age group. 12 cases (40% patients were primigravidae and 9(30% patients were multigravidae and 9 cases (30% presented in post-partum period. Eighteen cases (60% with ARF were seen in third trimester, followed by in postpartum period 9 cases (30%. Most common contributing factors to ARF were Pre-eclampsia, eclampsia and HELLP syndrome 60%, sepsis 56.6%, post abortal ARF 10%. DIC 40%. Haemorrhage as the aetiology for ARF was present 46%, APH in 20% and PPH in 26.6%. The type of ARF was renal in (63% and prerenal (36%; Oliguric seen in 10 patients (33% and high mortality (30%. Among the 20 pregnant patients with ARF, The average period of gestation was 33±2 weeks (30 -36 weeks, 5 cases (25% presented with intrauterine fetal demise and 18 cases (66% had preterm vaginal delivery and 2 cases (10% had induced abortion. And the average birth weight was 2±0.5 kg (1.5 kg. Eight cases (26% required dialysis. 80% of patients recovered completely of renal functions. 63% patients recovered without renal replacement therapy whereas 17% required dialysis. the maternal mortality was 20%, the main reason for mortality was septic shock and multi organ dysfunction (66%. CONCLUSION: ARF related pregnancy was seen commonly in the primigravidae and in the third trimester, the most

  9. BARNARD 59: NO EVIDENCE FOR FURTHER FRAGMENTATION

    Energy Technology Data Exchange (ETDEWEB)

    Roman-Zuniga, C. G. [Instituto de Astronomia, Universidad Nacional Autonoma de Mexico, Km 103 Carr. Tijuana-Ensenada, Ensenada BC 22860 (Mexico); Frau, P.; Girart, J. M. [Institut de Ciencies de l' Espai (CSIC-IEEC), Campus UAB, Facultat de Ciencies, Torre C-5p, 08193 Bellaterra, Catalunya (Spain); Alves, Joao F., E-mail: croman@astrosen.unam.mx [Institute of Astronomy, University of Vienna, Tuerkenschanzstr. 17, 1180 Vienna (Austria)

    2012-03-10

    The dense molecular clump at the center of the Barnard 59 (B59) complex is the only region in the Pipe Nebula that has formed a small, stellar cluster. The previous analysis of a high-resolution near-IR dust extinction map revealed that the nuclear region in B59 is a massive, mostly quiescent clump of 18.9 M{sub Sun }. The clump shows a monolithic profile, possibly indicating that the clump is on the way to collapse, with no evident fragmentation that could lead to another group of star systems. In this paper, we present new analysis that compares the dust extinction map with a new dust emission radio-continuum map of higher spatial resolution. We confirm that the clump does not show any significant evidence for prestellar fragmentation at scales smaller than those probed previously.

  10. BARNARD 59: NO EVIDENCE FOR FURTHER FRAGMENTATION

    International Nuclear Information System (INIS)

    Román-Zúñiga, C. G.; Frau, P.; Girart, J. M.; Alves, João F.

    2012-01-01

    The dense molecular clump at the center of the Barnard 59 (B59) complex is the only region in the Pipe Nebula that has formed a small, stellar cluster. The previous analysis of a high-resolution near-IR dust extinction map revealed that the nuclear region in B59 is a massive, mostly quiescent clump of 18.9 M ☉ . The clump shows a monolithic profile, possibly indicating that the clump is on the way to collapse, with no evident fragmentation that could lead to another group of star systems. In this paper, we present new analysis that compares the dust extinction map with a new dust emission radio-continuum map of higher spatial resolution. We confirm that the clump does not show any significant evidence for prestellar fragmentation at scales smaller than those probed previously.

  11. Fission fragment distributions within dynamical approach

    Energy Technology Data Exchange (ETDEWEB)

    Mazurek, K. [Institute of Nuclear, Physics Polish Academy of Sciences, Krakow (Poland); Nadtochy, P.N. [Omsk State Technical University, Omsk (Russian Federation); Ryabov, E.G.; Adeev, G.D. [Omsk State University, Physics Department, Omsk (Russian Federation)

    2017-04-15

    The review covers recent developments and achievements in the dynamical description of fission process at high excitation energy. It is shown that the dynamical approach based on multidimensional Langevin equations combined with the statistical description of nuclear decay by particles evaporation is capable of fairly well describing the formation of fission fragment mass-energy, charge, and angular distributions of fission fragments in coincidence with the pre- and post-scission particle emission. The final yields of fission and evaporation residues channels products could be obtained. The detailed description of fission dynamics allows studying different stages of fission process, indicating the most important ingredients governing fission process and studying in detail such fundamental nuclear properties as nuclear viscosity and fission timescale. The tasks and perspectives of multidimensional dynamical approach are also discussed. (orig.)

  12. Gastric Perforation by Ingested Rabbit Bone Fragment

    Directory of Open Access Journals (Sweden)

    Giulio Gambaracci

    2016-04-01

    Full Text Available The majority of accidentally ingested foreign bodies is excreted from the gastrointestinal (GI tract without any complications. Sometimes sharp foreign bodies – like chicken and fish bones – can lead to intestinal perforation and may present insidiously with a wide range of symptoms and, consequently, different diagnoses. We report the case of a 59-year-old woman presenting with fever and a 1-month history of vague abdominal pain. Computed tomography (CT showed the presence of a hyperdense linear image close to the gastric antrum surrounded by a fluid collection and free peritoneal air. At laparotomy, a 4-cm rabbit bone fragment covered in inflamed tissue was detected next to a gastric wall perforation. Rabbit bone fragment ingestion, even if rarely reported, should not be underestimated as a possible cause of GI tract perforation.

  13. Transport of Calcareous Fragments by Reef Fishes.

    Science.gov (United States)

    Bardach, J E

    1961-01-13

    The weight of sand, coral scrapings, algal fragments, and other calcareous materials which pass through the intestines of reef fishes was calculated on a hectare-per-year basis. It was found that browsing omnivorous reef fishes which rely, in part, on a plant diet ingested and redeposited at least 2300 kg of such material on a 1-hectare study reef near Bermuda. Reasons are presented why this estimate, certainly in order of magnitude, should be applicable to coral reefs in general.

  14. On the universality of quark jet fragmentation

    International Nuclear Information System (INIS)

    Dias de Deus, J.; Jadach, S.

    1977-01-01

    Universality of inclusive fragmentation density functions in lepton induced processes (ep, γp, e + e - ) and purely hadronic processes is discussed from the point of view of the Topological Expansion/Dual Unitarization Scheme. It is shown that planar, single jet dominated processes have universal inclusive distributions and average multiplicities. In multi-jet processes, treated in a simple approximation, is inversely proportional to the number N of jets and the magnitude of the seagull effect increases as N 2 . (Auth.)

  15. Fragmentation model analysis of EN2700 fireball

    Czech Academy of Sciences Publication Activity Database

    Spurný, Pavel; Ceplecha, Zdeněk

    2005-01-01

    Roč. 95, 1-4 (2005), s. 477-487 ISSN 0167-9295. [Meteoroids 2004. London, Ontario, 16.08.2004-20.08.2004] R&D Projects: GA ČR GA205/03/1404 Institutional research plan: CEZ:AV0Z10030501 Keywords : ablation * fireball * fragmentation Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 0.975, year: 2005

  16. Fragmentation in rotating isothermal protostellar clouds

    International Nuclear Information System (INIS)

    Bodenheimer, P.; Black, D.C.

    1980-01-01

    In this paper we report briefly the results of an extensive set of 3-D hydrodynamic calculations that have been performed during the past two and one-half years to investigate the susceptibility of rotating clouds to gravitational fragmentation. Because of the immensity of parameter space and the expense of computations, we have chosen to restrict this investigation to strictly isothermal collapse sequences. (orig./WL)

  17. Validating PHITS for heavy ion fragmentation reactions

    International Nuclear Information System (INIS)

    Ronningen, Reginald M.

    2015-01-01

    The performance of the Monte Carlo code system PHITS is validated for heavy-ion transport capabilities by performing simulations and comparing results against experimental data from heavy-ion reactions of benchmark quality. These data are from measurements of isotope yields produced in the fragmentation of a 140 MeV/u "4"8Ca beam on a beryllium target and on a tantalum target. The results of this study show that PHITS performs reliably. (authors)

  18. Autoimmune premature ovarian failure

    Directory of Open Access Journals (Sweden)

    Beata Komorowska

    2017-02-01

    Full Text Available Premature ovarian failure (POF, also termed as primary ovarian insufficiency (POI, is a highly heterogenous condition affecting 0.5-3.0% of women in childbearing age. These young women comprise quite a formidable group with unique physical and psychological needs that require special attention. Premature ovarian senescence (POS in all of its forms evolves insidiously as a basically asymptomatic process, leading to complete loss of ovarian function, and POI/POF diagnoses are currently made at relatively late stages. Well-known and well-documented risk factors exist, and the presence or suspicion of autoimmune disorder should be regarded as an important one. Premature ovarian failure is to some degree predictable in its occurrence and should be considered while encountering young women with loss of menstrual regularity, especially when there is a concomitant dysfunction in the immune system.

  19. Scarred by Failure?

    DEFF Research Database (Denmark)

    Mahieu, Jeroen; Melillo, Francesca; Reichstein, Toke

    Are failed entrepreneurs penalized in the labour market? The answer is yes under certain conditions. Using a novel dataset of matched entrepreneurs and employees in Belgium, we show that: on average, entrepreneurs returning to the labour market after a business failure are penalized, but this eff......Are failed entrepreneurs penalized in the labour market? The answer is yes under certain conditions. Using a novel dataset of matched entrepreneurs and employees in Belgium, we show that: on average, entrepreneurs returning to the labour market after a business failure are penalized...... years do not get penalized. Entrepreneurs who fail fast and move to a new employer limit the wage penalty by changing industry compared to the industry they were venturing in. These results are consistent with theories of adverse selection in the labour market....

  20. Satellite failures revisited

    Science.gov (United States)

    Balcerak, Ernie

    2012-12-01

    In January 1994, the two geostationary satellites known as Anik-E1 and Anik-E2, operated by Telesat Canada, failed one after the other within 9 hours, leaving many northern Canadian communities without television and data services. The outage, which shut down much of the country's broadcast television for hours and cost Telesat Canada more than $15 million, generated significant media attention. Lam et al. used publicly available records to revisit the event; they looked at failure details, media coverage, recovery effort, and cost. They also used satellite and ground data to determine the precise causes of those satellite failures. The researchers traced the entire space weather event from conditions on the Sun through the interplanetary medium to the particle environment in geostationary orbit.

  1. Rate based failure detection

    Science.gov (United States)

    Johnson, Brett Emery Trabun; Gamage, Thoshitha Thanushka; Bakken, David Edward

    2018-01-02

    This disclosure describes, in part, a system management component and failure detection component for use in a power grid data network to identify anomalies within the network and systematically adjust the quality of service of data published by publishers and subscribed to by subscribers within the network. In one implementation, subscribers may identify a desired data rate, a minimum acceptable data rate, desired latency, minimum acceptable latency and a priority for each subscription. The failure detection component may identify an anomaly within the network and a source of the anomaly. Based on the identified anomaly, data rates and or data paths may be adjusted in real-time to ensure that the power grid data network does not become overloaded and/or fail.

  2. LHC Magnet test failure

    CERN Multimedia

    2007-01-01

    "On Tueday, March 22, a Fermilab-built quadrupole magnet, one of an "inner triplet" of three focusing magnets, failed a high-pressure test at Point 5 in the tunnel of the LHC accelerator at CERN. Since Tuesday, teams at CERN and Fermilab have worked closely together to address the problem and have identified the cause of the failure. Now they are at work on a solution.:" (1 page)

  3. Failures of chain systems

    CSIR Research Space (South Africa)

    James, A

    1997-03-01

    Full Text Available ?C and intermittent exposure at 400--450 ?C. Unlike structural steels, which become softer and more ductile when reheated in service, manga- nese steels become brittle when reheated sufficiently to induce carbide... to form a roughly oval shaped crack until the link section could no longer withstand the applied loading experienced during normal dragline operations, and this resulted in final fast brittle failure. The general...

  4. Rethinking Heart Failure

    OpenAIRE

    F?rstenwerth, Hauke

    2012-01-01

    An increasing body of clinical observations and experimental evidence suggests that cardiac dysfunction results from autonomic dysregulation of the contractile output of the heart. Excessive activation of the sympathetic nervous system and a decrease in parasympathetic tone are associated with increased mortality. Elevated levels of circulating catecholamines closely correlate with the severity and poor prognosis in heart failure. Sympathetic over-stimulation causes increased levels of catech...

  5. Diastolic Heart Failure

    OpenAIRE

    Wake, Ryotaro; Yoshikawa, Junichi; Yoshiyama, Minoru

    2012-01-01

    Primary diastolic failure is typically seen in patients with hypertensive or valvular heart disease as well as in hypertrophic or restrictive cardiomyopathy but can also occur in a variety of clinical disorders, especially tachycardia and ischemia. Diastolic dysfunction has a particularly high prevalence in elderly patients and is generally associated, with low mortality but high morbidity. The pathophysiology of diastolic dysfunction includes delayed relaxation, impaired LV filling and/or in...

  6. Study of fragmentation reactions of light nucleus

    International Nuclear Information System (INIS)

    Toneli, David Arruda; Carlson, Brett Vern

    2011-01-01

    Full text: The decay of the compound nucleus is traditionally calculated using a sequential emission model, such as the Weisskopf-Ewing or Hauser-Feshbach ones, in which the compound nucleus decays through a series of residual nuclei by emitting one particle at a time until there is no longer sufficient energy for further emission. In light compound nucleus, however, the excitation energy necessary to fully disintegrate the system is relatively easy to attain. In such cases, decay by simultaneous emission of two or more particles becomes important. A model which takes into account all these decay is the Fermi fragmentation model. Recently, the equivalence between the Fermi fragmentation model and statistical multifragmentation model used to describe the decay for highly excited fragments for reactions of heavy ions was demonstrated. Due the simplicity of the thermodynamic treatment used in the multifragmentation model, we have adapted it to the calculation of Fermi breakup of light nuclei. The ultimate goal of this study is to calculate the distribution of isotopes produced in proton-induced reactions on light nuclei of biological interest, such as C, O e Ca. Although most of these residual nuclei possess extremely short half-lives and thus represent little long-term danger, they tend to be deficient in neutrons and to decay by positron emission, which allows the monitoring of proton radiotherapy by PET (Positron Emission Tomography). (author)

  7. Commissioning the A1900 projectile fragment separator

    CERN Document Server

    Morrissey, D J; Steiner, M; Stolz, A; Wiedenhöver, I

    2003-01-01

    An important part of the recent upgrade of the NSCL facility is the replacement of the A1200 fragment separator with a new high acceptance device called the A1900. The design of the A1900 device represents a third generation projectile fragment separator (relative to the early work at LBL) as it is situated immediately after the primary accelerator, has a very large acceptance, a bending power significantly larger than that of the cyclotron and is constructed from large superconducting magnets (quadrupoles with 20 and 40 cm diameter warm bores). The A1900 can accept over 90% of a large range of projectile fragmentation products produced at the NSCL, leading to large gains in the intensity of the secondary beams. The results of initial tests of the system with a restricted momentum acceptance (+-0.5%) indicate that the A1900 is performing up to specifications. Further large gains in the intensities of primary beams, typically two or three orders of magnitude, will be possible as the many facets of high current...

  8. Equilibrium and non equilibrium in fragmentation

    International Nuclear Information System (INIS)

    Dorso, C.O.; Chernomoretz, A.; Lopez, J.A.

    2001-01-01

    Full text: In this communication we present recent results regarding the interplay of equilibrium and non equilibrium in the process of fragmentation of excited finite Lennard Jones drops. Because the general features of such a potential resemble the ones of the nuclear interaction (fact that is reinforced by the similarity between the EOS of both systems) these studies are not only relevant from a fundamental point of view but also shed light on the problem of nuclear multifragmentation. We focus on the microscopic analysis of the state of the fragmenting system at fragmentation time. We show that the Caloric Curve (i e. the functional relationship between the temperature of the system and the excitation energy) is of the type rise plateau with no vapor branch. The usual rise plateau rise pattern is only recovered when equilibrium is artificially imposed. This result puts a serious question on the validity of the freeze out hypothesis. This feature is independent of the dimensionality or excitation mechanism. Moreover we explore the behavior of magnitudes which can help us determine the degree of the assumed phase transition. It is found that no clear cut criteria is presently available. (Author)

  9. Formation and fragmentation of protostellar dense cores

    International Nuclear Information System (INIS)

    Maury, Anaelle

    2009-01-01

    Stars form in molecular clouds, when they collapse and fragment to produce protostellar dense cores. These dense cores are then likely to contract under their own gravity, and form young protostars, that further evolve while accreting their circumstellar mass, until they reach the main sequence. The main goal of this thesis was to study the formation and fragmentation of protostellar dense cores. To do so, two main studies, described in this manuscript, were carried out. First, we studied the formation of protostellar cores by quantifying the impact of protostellar outflows on clustered star formation. We carried out a study of the protostellar outflows powered by the young stellar objects currently formed in the NGc 2264-C proto-cluster, and we show that protostellar outflows seem to play a crucial role as turbulence progenitors in clustered star forming regions, although they seem unlikely to significantly modify the global infall processes at work on clump scales. Second, we investigated the formation of multiple systems by core fragmentation, by using high - resolution observations that allow to probe the multiplicity of young protostars on small scales. Our results suggest that the multiplicity rate of protostars on small scales increase while they evolve, and thus favor dynamical scenarios for the formation of multiple systems. Moreover, our results favor magnetized scenarios of core collapse to explain the small-scale properties of protostars at the earliest stages. (author) [fr

  10. Intermittency in {sup 197}Au fragmentation

    Energy Technology Data Exchange (ETDEWEB)

    Dabrowska, A; Holynski, R; Olszewski, A; Szarska, M; Wilczynska, B; Wolter, W; Wosiek, B [Institute of Nuclear Physics, Cracow (Poland); Cherry, M L; Deines-Jones, P; Jones, W V; Sengupta, K; Wefel, B [Louisiana State Univ., Baton Rouge, LA (United States). Dept. of Physics and Astronomy; Waddington, C J [Minnesota Univ., Minneapolis, MN (United States). School of Physics and Astronomy; Pozharova, E A; Skorodko, T Yu [Inst. of Theoretical and Experimental Physics, Moscow (Russian Federation); KLMM Collaboration

    1995-07-01

    The concept of factorial moments was applied to an analysis of the dynamical fluctuations in the charge distributions of the fragments emitted from gold nuclei with energies 10.6 and < 1.0 GeV/n interacting with emulsion nuclei. Clear evidence for intermittent fluctuations has been found in an analysis using all the particles released from the gold projectile, with a stronger effect observed below 1 GeV/n than at 10.6 GeV/n. For the full data sets, however, the intermittency effect was found to be very sensitive to the singly charged particles, and neglecting these particles strongly reduces the intermittency signal. When the analysis is restricted to the multiply charged fragments, an intermittency effect is revealed only for multifragmentation events, although one that is enhanced as compared to the analysis of all, singly and multiply charged, particles. The properties of the anomalous fractal dimensions suggest a sequential decay mechanism, rather than the existence of possible critical behaviour in the process of nuclear fragmentation. The likely influence of the charge conservation effects and the finite size of decaying systems on the observed intermittency signals was pointed out. (author). 37 refs, 9 figs, 5 tabs.

  11. In silico fragment-based drug design.

    Science.gov (United States)

    Konteatis, Zenon D

    2010-11-01

    In silico fragment-based drug design (FBDD) is a relatively new approach inspired by the success of the biophysical fragment-based drug discovery field. Here, we review the progress made by this approach in the last decade and showcase how it complements and expands the capabilities of biophysical FBDD and structure-based drug design to generate diverse, efficient drug candidates. Advancements in several areas of research that have enabled the development of in silico FBDD and some applications in drug discovery projects are reviewed. The reader is introduced to various computational methods that are used for in silico FBDD, the fragment library composition for this technique, special applications used to identify binding sites on the surface of proteins and how to assess the druggability of these sites. In addition, the reader will gain insight into the proper application of this approach from examples of successful programs. In silico FBDD captures a much larger chemical space than high-throughput screening and biophysical FBDD increasing the probability of developing more diverse, patentable and efficient molecules that can become oral drugs. The application of in silico FBDD holds great promise for historically challenging targets such as protein-protein interactions. Future advances in force fields, scoring functions and automated methods for determining synthetic accessibility will all aid in delivering more successes with in silico FBDD.

  12. Integrated delivery systems: the cure for fragmentation.

    Science.gov (United States)

    Enthoven, Alain C

    2009-12-01

    Our healthcare system is fragmented, with a misalignment of incentives, or lack of coordination, that spawns inefficient allocation of resources. Fragmentation adversely impacts quality, cost, and outcomes. Eliminating waste from unnecessary, unsafe care is crucial for improving quality and reducing costs--and making the system financially sustainable. Many believe this can be achieved through greater integration of healthcare delivery, more specifically via integrated delivery systems (IDSs). An IDS is an organized, coordinated, and collaborative network that links various healthcare providers to provide a coordinated, vertical continuum of services to a particular patient population or community. It is also accountable, both clinically and fiscally, for the clinical outcomes and health status of the population or community served, and has systems in place to manage and improve them. The marketplace already contains numerous styles and degrees of integration, ranging from Kaiser Permanente-style full integration, to more loosely organized individual practice associations, to public-private partnerships. Evidence suggests that IDSs can improve healthcare quality, improve outcomes, and reduce costs--especially for patients with complex needs--if properly implemented and coordinated. No single approach or public policy will fix the fragmented healthcare system, but IDSs represent an important step in the right direction.

  13. Heart Failure Society of America

    Science.gov (United States)

    ... MACRA Resource Portal The Heart Failure Society of America, Inc. (HFSA) represents the first organized effort by heart failure experts from the Americas to provide a forum for all those interested ...

  14. Heart Failure in the Elderly

    NARCIS (Netherlands)

    B. Cost (Bernard)

    2000-01-01

    textabstractHeart failure is a clinical syndrome with various causes for which no universally accepted definition exists. Packer's definition of heart failure "representing a complex clinical syndrome characterised by abnonnalities of left ventricular function and neurohumoral regulation. which are

  15. Heart failure - fluids and diuretics

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/patientinstructions/000112.htm Heart failure - fluids and diuretics To use the sharing features ... to Expect at Home When you have heart failure, your heart does not pump out enough blood. This causes ...

  16. Fragmentation Point Detection of JPEG Images at DHT Using Validator

    Science.gov (United States)

    Mohamad, Kamaruddin Malik; Deris, Mustafa Mat

    File carving is an important, practical technique for data recovery in digital forensics investigation and is particularly useful when filesystem metadata is unavailable or damaged. The research on reassembly of JPEG files with RST markers, fragmented within the scan area have been done before. However, fragmentation within Define Huffman Table (DHT) segment is yet to be resolved. This paper analyzes the fragmentation within the DHT area and list out all the fragmentation possibilities. Two main contributions are made in this paper. Firstly, three fragmentation points within DHT area are listed. Secondly, few novel validators are proposed to detect these fragmentations. The result obtained from tests done on manually fragmented JPEG files, showed that all three fragmentation points within DHT are successfully detected using validators.

  17. Production of a phage-displayed single chain variable fragment ...

    African Journals Online (AJOL)

    Abstract. Purpose: To develop specific single chain variable fragments (scFv) against ... libraries. The binding ability of the selected scFv antibody fragments against the IBDV particles was ..... Hermelink H, Koscielniak E. A human recombinant.

  18. Towards a population synthesis model of self-gravitating disc fragmentation and tidal downsizing II: the effect of fragment-fragment interactions

    Science.gov (United States)

    Forgan, D. H.; Hall, C.; Meru, F.; Rice, W. K. M.

    2018-03-01

    It is likely that most protostellar systems undergo a brief phase where the protostellar disc is self-gravitating. If these discs are prone to fragmentation, then they are able to rapidly form objects that are initially of several Jupiter masses and larger. The fate of these disc fragments (and the fate of planetary bodies formed afterwards via core accretion) depends sensitively not only on the fragment's interaction with the disc, but also with its neighbouring fragments. We return to and revise our population synthesis model of self-gravitating disc fragmentation and tidal downsizing. Amongst other improvements, the model now directly incorporates fragment-fragment interactions while the disc is still present. We find that fragment-fragment scattering dominates the orbital evolution, even when we enforce rapid migration and inefficient gap formation. Compared to our previous model, we see a small increase in the number of terrestrial-type objects being formed, although their survival under tidal evolution is at best unclear. We also see evidence for disrupted fragments with evolved grain populations - this is circumstantial evidence for the formation of planetesimal belts, a phenomenon not seen in runs where fragment-fragment interactions are ignored. In spite of intense dynamical evolution, our population is dominated by massive giant planets and brown dwarfs at large semimajor axis, which direct imaging surveys should, but only rarely, detect. Finally, disc fragmentation is shown to be an efficient manufacturer of free-floating planetary mass objects, and the typical multiplicity of systems formed via gravitational instability will be low.

  19. [The fragmentation of representational space in schizophrenia].

    Science.gov (United States)

    Plagnol, A; Oïta, M; Montreuil, M; Granger, B; Lubart, T

    2003-01-01

    Existent neurocognitive models of schizophrenia converge towards a core of impairments involving working memory, context processing, action planning, controlled and intentional processing. However, the emergence of this core remains itself difficult to explain and more specific hypotheses do not explain the heterogeneity of schizophrenia. To overcome these limits, we propose a new paradigm based on representational theory from cognitive science. Some recent developments of this theory enable us to describe a subjective universe as a representational space which is displayed from memory. We outline a conceptual framework to construct such a representational space from analogical -representations that can be activated in working memory and are connected to a network of symbolic structures. These connections are notably made through an analytic process of the analogical fragments, which involves the attentional focus. This framework allows us to define rigorously some defense processes in response to traumatic tensions that are expressed on the representational space. The fragmentation of representational space is a consequence of a defensive denial based on an impairment of the analytic process. The fragmentation forms some parasitic areas in memory which are excluded from the main part of the representational space and disturb information processing. The key clinical concepts of paranoid syndromes can be defined in this conceptual framework: mental automatism, delusional intuition, acute destructuration, psychotic dissociation, and autistic withdrawal. We show that these syndromes imply each other, which in return increases the fragmentation of the representational space. Some new concepts emerge naturally in this framework, such as the concept of "suture" which is defined as a link between a parasitic area and the main representational space. Schizophrenia appears as a borderline case of fragmentation of the representational space. This conceptual framework is

  20. Stochastic failure modelling of unidirectional composite ply failure

    International Nuclear Information System (INIS)

    Whiteside, M.B.; Pinho, S.T.; Robinson, P.

    2012-01-01

    Stochastic failure envelopes are generated through parallelised Monte Carlo Simulation of a physically based failure criteria for unidirectional carbon fibre/epoxy matrix composite plies. Two examples are presented to demonstrate the consequence on failure prediction of both statistical interaction of failure modes and uncertainty in global misalignment. Global variance-based Sobol sensitivity indices are computed to decompose the observed variance within the stochastic failure envelopes into contributions from physical input parameters. The paper highlights a selection of the potential advantages stochastic methodologies offer over the traditional deterministic approach.

  1. Global patterns of fragmentation and connectivity of mammalian carnivore habitat

    OpenAIRE

    Crooks, Kevin R.; Burdett, Christopher L.; Theobald, David M.; Rondinini, Carlo; Boitani, Luigi

    2011-01-01

    Although mammalian carnivores are vulnerable to habitat fragmentation and require landscape connectivity, their global patterns of fragmentation and connectivity have not been examined. We use recently developed high-resolution habitat suitability models to conduct comparative analyses and to identify global hotspots of fragmentation and connectivity for the world's terrestrial carnivores. Species with less fragmentation (i.e. more interior high-quality habitat) had larger geographical ranges...

  2. Cross sections and kinematics of proton induced fragmentation of carbon

    International Nuclear Information System (INIS)

    Streibel, T.; Roecher, H.; Huentrup, G.; Heinrich, W.

    1997-01-01

    Charge changing fragmentation cross sections for C at a proton energy of about 70 MeV were measured. The discrepancies between measurement and model predictions indicate the necessity of further investigations. We have also measured distributions of fragment emission angles which can be described using a model with a momentum transfer to the fragmenting nucleus. The developed model leads to predictions for momentum distributions of proton induced target fragments of C at small energies. (orig.)

  3. Cross sections and kinematics of proton induced fragmentation of carbon

    Energy Technology Data Exchange (ETDEWEB)

    Streibel, T; Roecher, H; Huentrup, G; Heinrich, W [Siegen Univ. (Germany). Dept. of Physics

    1997-09-01

    Charge changing fragmentation cross sections for C at a proton energy of about 70 MeV were measured. The discrepancies between measurement and model predictions indicate the necessity of further investigations. We have also measured distributions of fragment emission angles which can be described using a model with a momentum transfer to the fragmenting nucleus. The developed model leads to predictions for momentum distributions of proton induced target fragments of C at small energies. (orig.)

  4. Effect of fragmentation on the Costa Rican dry forest avifauna

    OpenAIRE

    Barrantes, Gilbert; Ocampo, Diego; Ram?rez-Fern?ndez, Jos? D.; Fuchs, Eric J.

    2016-01-01

    Deforestation and changes in land use have reduced the tropical dry forest to isolated forest patches in northwestern Costa Rica. We examined the effect of patch area and length of the dry season on nestedness of the entire avian community, forest fragment assemblages, and species occupancy across fragments for the entire native avifauna, and for a subset of forest dependent species. Species richness was independent of both fragment area and distance between fragments. Similarity in bird comm...

  5. Generic component failure data base

    International Nuclear Information System (INIS)

    Eide, S.A.; Calley, M.B.

    1992-01-01

    This report discusses comprehensive component generic failure data base which has been developed for light water reactor probabilistic risk assessments. The Nuclear Computerized Library for Assessing Reactor Reliability (NUCLARR) was used to generate component failure rates. Using this approach, most of the failure rates are based on actual plant data rather then existing estimates

  6. Your Heart Failure Healthcare Team

    Science.gov (United States)

    ... Artery Disease Venous Thromboembolism Aortic Aneurysm More Your Heart Failure Healthcare Team Updated:May 9,2017 Patients with ... to the Terms and Conditions and Privacy Policy Heart Failure • Home • About Heart Failure • Causes and Risks for ...

  7. Planning Ahead: Advanced Heart Failure

    Science.gov (United States)

    ... Venous Thromboembolism Aortic Aneurysm More Planning Ahead: Advanced Heart Failure Updated:May 9,2017 An important part of ... Care This content was last reviewed May 2017. Heart Failure • Home • About Heart Failure • Causes and Risks for ...

  8. General-purpose heat source: Research and development program, radioisotope thermoelectric generator/thin fragment impact test

    International Nuclear Information System (INIS)

    Reimus, M.A.H.; Hinckley, J.E.

    1996-11-01

    The general-purpose heat source provides power for space missions by transmitting the heat of 238 Pu decay to an array of thermoelectric elements in a radioisotope thermoelectric generator (RTG). Because the potential for a launch abort or return from orbit exists for any space mission, the heat source response to credible accident scenarios is being evaluated. This test was designed to provide information on the response of a loaded RTG to impact by a fragment similar to the type of fragment produced by breakup of the spacecraft propulsion module system. The results of this test indicated that impact by a thin aluminum fragment traveling at 306 m/s may result in significant damage to the converter housing, failure of one fueled clad, and release of a small quantity of fuel

  9. Temporal change in fragmentation of continental US forests

    Science.gov (United States)

    James D. Wickham; Kurt H. Riitters; Timothy G. Wade; Collin Homer

    2008-01-01

    Changes in forest ecosystem function and condition arise from changes in forest fragmentation. Previous studies estimated forest fragmentation for the continental United States (US). In this study, new temporal land-cover data from the National Land Cover Database (NLCD) were used to estimate changes in forest fragmentation at multiple scales for the continental US....

  10. High efficiency hydrodynamic DNA fragmentation in a bubbling system

    NARCIS (Netherlands)

    Li, Lanhui; Jin, Mingliang; Sun, Chenglong; Wang, Xiaoxue; Xie, Shuting; Zhou, Guofu; Van Den Berg, Albert; Eijkel, Jan C.T.; Shui, Lingling

    2017-01-01

    DNA fragmentation down to a precise fragment size is important for biomedical applications, disease determination, gene therapy and shotgun sequencing. In this work, a cheap, easy to operate and high efficiency DNA fragmentation method is demonstrated based on hydrodynamic shearing in a bubbling

  11. Regional Forest Fragmentation and the Nesting Success of Migratory Birds

    Science.gov (United States)

    Scott K. Robinson; Frank R. Thompson III; Therese M. Donovan; Donald R. Whitehead; John Faaborg

    1995-01-01

    Forest fragmentation, the disruption in the continuity of forest habitat, is hypothesized to be a major cause of population decline for, some species of forest birds because fragmentation reduces nesting (reproductive) success. Nest predation and parasitism by cowbirds increased with forest fragmentation in nine midwestern (United States)landscapes that varied from 6...

  12. Fission fragment mass distributions via prompt γ-ray spectroscopy

    Indian Academy of Sciences (India)

    The distribution of fragment masses formed in nuclear fission is one of the most strik- ing features .... 80. 100. 120. 140. 160. 10. 3. 10. 4. Fragment Mass. Relative yield. Sn. Cd. Te. Pd ... the secondary fragment at Z = 50 and N = 82 shells, where the yields are depleted. Both ... More systematic experimental data are required.

  13. Autodigestion: Proteolytic Degradation and Multiple Organ Failure in Shock

    Science.gov (United States)

    Altshuler, Angelina E.; Kistler, Erik B.; Schmid-Schönbein, Geert W.

    2015-01-01

    There is currently no effective treatment for multiorgan failure following shock other than alleviation supportive care. A better understanding of the pathogenesis of these sequelae to shock is required. The intestine plays a central role in multiorgan failure. It was previously suggested that bacteria and their toxins are responsible for the organ failure seen in circulatory shock, but clinical trials in septic patients have not confirmed this hypothesis. Instead, we review here evidence that the digestive enzymes, synthesized in the pancreas and discharged into the small intestine as requirement for normal digestion, may play a role in multi-organ failure. These powerful enzymes are non-specific, highly concentrated and fully activated in the lumen of the intestine. During normal digestion they are compartmentalized in the lumen of the intestine by the mucosal epithelial barrier. However, if this barrier becomes permeable, e.g. in an ischemic state, the digestive enzymes escape into the wall of the intestine. They digest tissues in the mucosa and generate small molecular weight cytotoxic fragments such as unbound free fatty acids. Digestive enzymes may also escape into the systemic circulation and activate other degrading proteases. These proteases have the ability to clip the ectodomain of surface receptors and compromise their function; for example cleaving the insulin receptor causing insulin resistance. The combination of digestive enzymes and cytotoxic fragments leaking into the central circulation causes cell and organ dysfunction, and ultimately may lead to complete organ failure and death. We summarize current evidence suggesting that enteral blockade of digestive enzymes inside the lumen of the intestine may serve to reduce acute cell and organ damage and improve survival in experimental shock. PMID:26717111

  14. Habitat fragmentation reduces nest survival in an Afrotropical bird community in a biodiversity hotspot.

    Science.gov (United States)

    Newmark, William D; Stanley, Thomas R

    2011-07-12

    Ecologists have long hypothesized that fragmentation of tropical landscapes reduces avian nest success. However, this hypothesis has not been rigorously assessed because of the difficulty of finding large numbers of well-hidden nests in tropical forests. Here we report that in the East Usambara Mountains in Tanzania, which are part of the Eastern Arc Mountains, a global biodiversity hotspot, that daily nest survival rate and nest success for seven of eight common understory bird species that we examined over a single breeding season were significantly lower in fragmented than in continuous forest, with the odds of nest failure for these seven species ranging from 1.9 to 196.8 times higher in fragmented than continuous forest. Cup-shaped nests were particularly vulnerable in fragments. We then examined over six breeding seasons and 14 study sites in a multivariable survival analysis the influence of landscape structure and nest location on daily nest survival for 13 common species representing 1,272 nests and four nest types (plate, cup, dome, and pouch). Across species and nest types, area, distance of nest to edge, and nest height had a dominant influence on daily nest survival, with area being positively related to nest survival and distance of nest to edge and nest height being both positively and negatively associated with daily nest survival. Our results indicate that multiple environmental factors contribute to reduce nest survival within a tropical understory bird community in a fragmented landscape and that maintaining large continuous forest is important for enhancing nest survival for Afrotropical understory birds.

  15. Teton Dam failure

    Energy Technology Data Exchange (ETDEWEB)

    Snorteland, N. [United States Dept. of the Interior, Washington, DC (United States). Bureau of Reclamation

    2009-07-01

    This case summary discussed an internal erosion failure that occurred at the embankment foundation of Teton Dam. The project was designed as a run-of-the-river power generation facility and to provide irrigation, flood protection, and power generation to the lower Teton region of southern Idaho. The dam site was located next to the eastern Snake River plain, a volcanic filled depression. The foundation's cutoff trench was excavated into the bedrock along the length of the dam. The dam was designed as a zoned earthfill with a height of 305 feet. A trench made of low plasticity windblown silt was designed to connect the embankment core to the rock foundation. Seeps were noted in 1976, and a leak was observed near the toe of the dam. A wet spot appeared on the downstream face of the dam at elevation 5200. A sinkhole then developed. The embankment crest collapsed, and the dam breached. Peak outflow was estimated at 1,000,000 cfs. The failure was attributed to a lack of communication between designers, a failure to understand geologic information about the region, and an insufficient review of designs and specifications by designers and field personnel. No monitoring instrumentation was installed in the embankment. Approximately 300 square miles were inundated, and 25,000 people were displaced. Eleven people were killed. A review group noted that the rock surface was not adequately sealed, and that the dam failed as a result of inadequate protection of the impervious core material from internal erosion. 42 figs.

  16. Steam generator tube failures

    International Nuclear Information System (INIS)

    MacDonald, P.E.; Shah, V.N.; Ward, L.W.; Ellison, P.G.

    1996-04-01

    A review and summary of the available information on steam generator tubing failures and the impact of these failures on plant safety is presented. The following topics are covered: pressurized water reactor (PWR), Canadian deuterium uranium (CANDU) reactor, and Russian water moderated, water cooled energy reactor (VVER) steam generator degradation, PWR steam generator tube ruptures, the thermal-hydraulic response of a PWR plant with a faulted steam generator, the risk significance of steam generator tube rupture accidents, tubing inspection requirements and fitness-for-service criteria in various countries, and defect detection reliability and sizing accuracy. A significant number of steam generator tubes are defective and are removed from service or repaired each year. This wide spread damage has been caused by many diverse degradation mechanisms, some of which are difficult to detect and predict. In addition, spontaneous tube ruptures have occurred at the rate of about one every 2 years over the last 20 years, and incipient tube ruptures (tube failures usually identified with leak detection monitors just before rupture) have been occurring at the rate of about one per year. These ruptures have caused complex plant transients which have not always been easy for the reactor operators to control. Our analysis shows that if more than 15 tubes rupture during a main steam line break, the system response could lead to core melting. Although spontaneous and induced steam generator tube ruptures are small contributors to the total core damage frequency calculated in probabilistic risk assessments, they are risk significant because the radionuclides are likely to bypass the reactor containment building. The frequency of steam generator tube ruptures can be significantly reduced through appropriate and timely inspections and repairs or removal from service

  17. FRELIB, Failure Reliability Index Calculation

    International Nuclear Information System (INIS)

    Parkinson, D.B.; Oestergaard, C.

    1984-01-01

    1 - Description of problem or function: Calculation of the reliability index given the failure boundary. A linearization point (design point) is found on the failure boundary for a stationary reliability index (min) and a stationary failure probability density function along the failure boundary, provided that the basic variables are normally distributed. 2 - Method of solution: Iteration along the failure boundary which must be specified - together with its partial derivatives with respect to the basic variables - by the user in a subroutine FSUR. 3 - Restrictions on the complexity of the problem: No distribution information included (first-order-second-moment-method). 20 basic variables (could be extended)

  18. Automotive component failures

    CSIR Research Space (South Africa)

    Heyes, AM

    1998-06-01

    Full Text Available in service for approximately 19\\999 km[ 1[1[ Visual examination Upon stripping the engine it was found that one of the combustion chambers showed heavy carbonaceous deposits indicative of the burning of oil "Fig[ 2# Circumferential black marks were found... whether failures in other vehicles could be expected[ 2[1[ Visual and stereo microscope examination The section of torsion bar submitted for examination was coated with a black paint coating which had ~aked o} at localised spots\\ where light rusting had...

  19. Triggers of State Failure

    Science.gov (United States)

    2010-03-01

    à 1990) à l’aide de données collatérales additionnelles. Les auteurs du document n’ont pas essayé de suivre les événements qui étaient en cours...défaillance étatique, et les auteurs du document ont reconnu qu’il ne serait pas très utile de reproduire toutes ces informations. Le document s’appuie le...30 Carment, David. Assessing state failure: implications for theory and policy. in Third World Quarterly. Vol 24, no 3. pp 407-427. 30 DRDC

  20. New product failure

    DEFF Research Database (Denmark)

    Dijksterhuis, Garmt Bernard

    2016-01-01

    When new consumer products are developed and later launched, 50 to 75 percent of them are removed from the market far short of meeting their projected financial targets. In short: they fail. We conclude that this failure is due to institutionalized insufficiencies in the use of the sciences...... that are best geared to understand and predict consumer behaviour, viz. the behavioural sciences. These are not necessarily the same as the marketing science that is performed by marketing departments. A scientific approach to understanding consumer behaviour appears to be lacking in many corporate research...

  1. Premature ovarian failure

    Directory of Open Access Journals (Sweden)

    Persani Luca

    2006-04-01

    Full Text Available Abstract Premature ovarian failure (POF is a primary ovarian defect characterized by absent menarche (primary amenorrhea or premature depletion of ovarian follicles before the age of 40 years (secondary amenorrhea. It is a heterogeneous disorder affecting approximately 1% of women e.g. Turner syndrome represent the major cause of primary amenorrhea associated with ovarian dysgenesis. Despite the description of several candidate genes, the cause of POF remains undetermined in the vast majority of the cases. Management includes substitution of the hormone defect by estrogen/progestin preparations. The only solution presently available for the fertility defect in women with absent follicular reserve is ovum donation.

  2. Influence of spin on fission fragments anisotropy

    Directory of Open Access Journals (Sweden)

    Ghodsi Omid N.

    2005-01-01

    Full Text Available An analysis of selected fission fragment angular distribution when at least one of the spins of the projectile or target is appreciable in induced fission was made by using the statistical scission model. The results of this model predicate that the spins of the projectile or target are affected on the nuclear level density of the compound nucleus. The experimental data was analyzed by means of the couple channel spin effect formalism. This formalism suggests that the projectile spin is more effective on angular anisotropies within the limits of energy near the fusion barrier.

  3. Deciding Security for a Fragment of ASLan

    DEFF Research Database (Denmark)

    Mödersheim, Sebastian Alexander

    situations in security such as the interaction between the work ow of a system with its access control policies. While even the transition relation is undecidable for ASLan in general, we show the security problem is decidable for a large and useful fragment that we call TASLan, as long as we bound...... the number of steps of honest participants. The restriction of TASLan is that all messages and predicates must be in a certain sense unambiguous in their interpretation, excluding \\type-confusions" similar to some tagging results for security protocols....

  4. Fragmentation of Relativistic 56Fe Nuclei in Emulsion

    International Nuclear Information System (INIS)

    Chernov, G.M.; Gulamov, K.G.; Gulyamov, U.G.; Navotny, V.Sh.; Petrov, N.V.; Svechnikova, L.N.; Jakobsson, B.; Oskarsson, A.; Otterlund, I.

    1983-03-01

    Experimental data on general characteristics of projectile fragments in inelastic interactions of relativistic 56 Fe nuclei in emulsion (multiplicities, transverse momentum distributions, azimuthal correlations) are presented and discussed. A strong dependence on the mass number of the projectile nucleus is observed for the transverse momenta of the emitted projectile fragments. These fragments exhibit an azimuthal asymmetry caused by the transverse motion of the fragmenting residue, but it is shown that this motion can be responsible only for a part of the increase in the average transverse momentum of the fragments with increasing mass of the projectile. (author)

  5. Light particles emitted with the fission fragments of thorium

    Energy Technology Data Exchange (ETDEWEB)

    San-Tsiang, T; Faraggi, H

    1947-01-01

    The traces produced by the fission of thorium with fast neutrons have been recorded photographically and studied. The formation of a light fragment of long range by either quadripartition or tripartition was not observed. The release of a short-range light fragment by bipartition was observed about one hundred times more frequently than was the release of such a fragment by tripartition. The ratio of the range of the two heavy fragments produced by tripartition was 1:2; this compares with a ratio of 1:3 for the heavy fragments produced by bipartition.

  6. Scaling of structural failure

    Energy Technology Data Exchange (ETDEWEB)

    Bazant, Z.P. [Northwestern Univ., Evanston, IL (United States); Chen, Er-Ping [Sandia National Lab., Albuquerque, NM (United States)

    1997-01-01

    This article attempts to review the progress achieved in the understanding of scaling and size effect in the failure of structures. Particular emphasis is placed on quasibrittle materials for which the size effect is complicated. Attention is focused on three main types of size effects, namely the statistical size effect due to randomness of strength, the energy release size effect, and the possible size effect due to fractality of fracture or microcracks. Definitive conclusions on the applicability of these theories are drawn. Subsequently, the article discusses the application of the known size effect law for the measurement of material fracture properties, and the modeling of the size effect by the cohesive crack model, nonlocal finite element models and discrete element models. Extensions to compression failure and to the rate-dependent material behavior are also outlined. The damage constitutive law needed for describing a microcracked material in the fracture process zone is discussed. Various applications to quasibrittle materials, including concrete, sea ice, fiber composites, rocks and ceramics are presented.

  7. Delusions as performance failures.

    Science.gov (United States)

    Gerrans, P

    2001-08-01

    Delusions are explanations of anomalous experiences. A theory of delusion requires an explanation of both the anomalous experience and the apparently irrational explanation generated by the delusional subject. Hence, we require a model of rational belief formation against which the belief formation of delusional subjects can be evaluated. I first describe such a model, distinguishing procedural from pragmatic rationality. Procedural rationality is the use of rules or procedures, deductive or inductive, that produce an inferentially coherent set of propositions. Pragmatic rationality is the use of procedural rationality in context. I then apply the distinction to the explanation of the Capgras and the Cotard delusions. I then argue that delusions are failures of pragmatic rationality. I examine the nature of these failures employing the distinction between performance and competence familiar from Chomskian linguistics. This approach to the irrationality of delusions reconciles accounts in which the explanation of the anomalous experience exhausts the explanation of delusion, accounts that appeal to further deficits within the reasoning processes of delusional subjects, and accounts that argue that delusions are not beliefs at all. (Respectively, one-stage, two-stage, and expressive accounts.) In paradigm cases that concern cognitive neuropsychiatry the irrationality of delusional subjects should be thought of as a performance deficit in pragmatic rationality.

  8. Preparing for Failure

    International Nuclear Information System (INIS)

    Murphy, L.T.; Manson, A.W.

    2006-01-01

    Risk management is one of the most complex project management processes, requiring rigorous management and discipline. Unfortunately, for many organizations, the risk management process has become contaminated by poor management practices, an absence of meaningful risk assessments, meaningless risk event descriptions, incomplete and vague risk impact analyses, poor follow through on risk mitigation activities and a general lack of attention to accuracy, completeness and quality. At this point, the risk register, instead of being a key tool used by the organization to systematically identify and eliminate risk, while exploiting opportunities, has become a list of pre-prepared excuses based on the repeat of failures encountered on past projects. However, organizations are not condemned to repeat past failures. By returning to the basics of risk management, and through the application of some basic management guidelines, the risk register-instead of being an 'Excuse Register' - can become the cornerstone of a comprehensive risk management program to promote a systematic, pro-active approach within an organization that will result in accomplishing mitigation activities, reducing risk and gaining advantage through opportunities. (authors)

  9. SCEDS: protein fragments for molecular replacement in Phaser

    Energy Technology Data Exchange (ETDEWEB)

    McCoy, Airlie J., E-mail: ajm201@cam.ac.uk [University of Cambridge, Hills Road, Cambridge CB2 0XY (United Kingdom); Nicholls, Robert A. [MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge Biomedical Campus, Cambridge CB2 0QH (United Kingdom); Schneider, Thomas R. [Hamburg Unit c/o DESY, Notkestrasse 85, 22603 Hamburg (Germany); University of Cambridge, Hills Road, Cambridge CB2 0XY (United Kingdom)

    2013-11-01

    Protein fragments suitable for use in molecular replacement can be generated by normal-mode perturbation, analysis of the difference distance matrix of the original versus normal-mode perturbed structures, and SCEDS, a score that measures the sphericity, continuity, equality and density of the resulting fragments. A method is described for generating protein fragments suitable for use as molecular-replacement (MR) template models. The template model for a protein suspected to undergo a conformational change is perturbed along combinations of low-frequency normal modes of the elastic network model. The unperturbed structure is then compared with each perturbed structure in turn and the structurally invariant regions are identified by analysing the difference distance matrix. These fragments are scored with SCEDS, which is a combined measure of the sphericity of the fragments, the continuity of the fragments with respect to the polypeptide chain, the equality in number of atoms in the fragments and the density of C{sup α} atoms in the triaxial ellipsoid of the fragment extents. The fragment divisions with the highest SCEDS are then used as separate template models for MR. Test cases show that where the protein contains fragments that undergo a change in juxtaposition between template model and target, SCEDS can identify fragments that lead to a lower R factor after ten cycles of all-atom refinement with REFMAC5 than the original template structure. The method has been implemented in the software Phaser.

  10. SCEDS: protein fragments for molecular replacement in Phaser

    International Nuclear Information System (INIS)

    McCoy, Airlie J.; Nicholls, Robert A.; Schneider, Thomas R.

    2013-01-01

    Protein fragments suitable for use in molecular replacement can be generated by normal-mode perturbation, analysis of the difference distance matrix of the original versus normal-mode perturbed structures, and SCEDS, a score that measures the sphericity, continuity, equality and density of the resulting fragments. A method is described for generating protein fragments suitable for use as molecular-replacement (MR) template models. The template model for a protein suspected to undergo a conformational change is perturbed along combinations of low-frequency normal modes of the elastic network model. The unperturbed structure is then compared with each perturbed structure in turn and the structurally invariant regions are identified by analysing the difference distance matrix. These fragments are scored with SCEDS, which is a combined measure of the sphericity of the fragments, the continuity of the fragments with respect to the polypeptide chain, the equality in number of atoms in the fragments and the density of C α atoms in the triaxial ellipsoid of the fragment extents. The fragment divisions with the highest SCEDS are then used as separate template models for MR. Test cases show that where the protein contains fragments that undergo a change in juxtaposition between template model and target, SCEDS can identify fragments that lead to a lower R factor after ten cycles of all-atom refinement with REFMAC5 than the original template structure. The method has been implemented in the software Phaser

  11. Predicting "Hot" and "Warm" Spots for Fragment Binding.

    Science.gov (United States)

    Rathi, Prakash Chandra; Ludlow, R Frederick; Hall, Richard J; Murray, Christopher W; Mortenson, Paul N; Verdonk, Marcel L

    2017-05-11

    Computational fragment mapping methods aim to predict hotspots on protein surfaces where small fragments will bind. Such methods are popular for druggability assessment as well as structure-based design. However, to date researchers developing or using such tools have had no clear way of assessing the performance of these methods. Here, we introduce the first diverse, high quality validation set for computational fragment mapping. The set contains 52 diverse examples of fragment binding "hot" and "warm" spots from the Protein Data Bank (PDB). Additionally, we describe PLImap, a novel protocol for fragment mapping based on the Protein-Ligand Informatics force field (PLIff). We evaluate PLImap against the new fragment mapping test set, and compare its performance to that of simple shape-based algorithms and fragment docking using GOLD. PLImap is made publicly available from https://bitbucket.org/AstexUK/pli .

  12. Kaon fragmentation function from NJL-jet model

    International Nuclear Information System (INIS)

    Matevosyan, Hrayr H.; Thomas, Anthony W.; Bentz, Wolfgang

    2010-01-01

    The NJL-jet model provides a sound framework for calculating the fragmentation functions in an effective chiral quark theory, where the momentum and isospin sum rules are satisfied without the introduction of ad hoc parameters [1]. Earlier studies of the pion fragmentation functions using the Nambu-Jona-Lasinio (NJL) model within this framework showed good qualitative agreement with the empirical parameterizations. Here we extend the NJL-jet model by including the strange quark. The corrections to the pion fragmentation function and corresponding kaon fragmentation functions are calculated using the elementary quark to quark-meson fragmentation functions from NJL. The results for the kaon fragmentation function exhibit a qualitative agreement with the empirical parameterizations, while the unfavored strange quark fragmentation to pions is shown to be of the same order of magnitude as the unfavored light quark's. The results of these studies are expected to provide important guidance for the analysis of a large variety of semi-inclusive data.

  13. Heavy-Quark Production in the Target Fragmentation Region

    CERN Document Server

    Graudenz, Dirk

    1997-01-01

    Fixed-target experiments permit the study of hadron production in the target fragmentation region. It is expected that the tagging of specific particles in the target fragments can be employed to introduce a bias in the hard scattering process towards a specific flavour content. The case of hadrons containing a heavy quark is particularly attractive because of the clear experimental signatures and the applicability of perturbative QCD. The standard approach to one-particle inclusive processes based on fragmentation functions is valid in the current fragmentation region and for large transverse momenta $p_T$ in the target fragmentation region, but it fails for particle production at small $p_T$ in the target fragmentation region. A collinear singularity, which cannot be absorbed in the standard way into the phenomenological distribution functions, prohibits the application of this procedure. This situation is remedied by the introduction of a new set of distribution functions, the target fragmentation function...

  14. Agricultural matrices affect ground ant assemblage composition inside forest fragments.

    Directory of Open Access Journals (Sweden)

    Diego Santana Assis

    Full Text Available The establishment of agricultural matrices generally involves deforestation, which leads to fragmentation of the remaining forest. This fragmentation can affect forest dynamics both positively and negatively. Since most animal species are affected, certain groups can be used to measure the impact of such fragmentation. This study aimed to measure the impacts of agricultural crops (matrices on ant communities of adjacent lower montane Atlantic rainforest fragments. We sampled nine forest fragments at locations surrounded by different agricultural matrices, namely: coffee (3 replicates; sugarcane (3; and pasture (3. At each site we installed pitfall traps along a 500 m transect from the interior of the matrix to the interior of the fragment (20 pitfall traps ~25 m apart. Each transect was partitioned into four categories: interior of the matrix; edge of the matrix; edge of the fragment; and interior of the fragment. For each sample site, we measured ant species richness and ant community composition within each transect category. Ant richness and composition differed between fragments and matrices. Each sample location had a specific composition of ants, probably because of the influence of the nature and management of the agricultural matrices. Species composition in the coffee matrix had the highest similarity to its corresponding fragment. The variability in species composition within forest fragments surrounded by pasture was greatest when compared with forest fragments surrounded by sugarcane or, to a lesser extent, coffee. Functional guild composition differed between locations, but the most representative guild was 'generalist' both in the agricultural matrices and forest fragments. Our results are important for understanding how agricultural matrices act on ant communities, and also, how these isolated forest fragments could act as an island of biodiversity in an 'ocean of crops'.

  15. Agricultural matrices affect ground ant assemblage composition inside forest fragments.

    Science.gov (United States)

    Assis, Diego Santana; Dos Santos, Iracenir Andrade; Ramos, Flavio Nunes; Barrios-Rojas, Katty Elena; Majer, Jonathan David; Vilela, Evaldo Ferreira

    2018-01-01

    The establishment of agricultural matrices generally involves deforestation, which leads to fragmentation of the remaining forest. This fragmentation can affect forest dynamics both positively and negatively. Since most animal species are affected, certain groups can be used to measure the impact of such fragmentation. This study aimed to measure the impacts of agricultural crops (matrices) on ant communities of adjacent lower montane Atlantic rainforest fragments. We sampled nine forest fragments at locations surrounded by different agricultural matrices, namely: coffee (3 replicates); sugarcane (3); and pasture (3). At each site we installed pitfall traps along a 500 m transect from the interior of the matrix to the interior of the fragment (20 pitfall traps ~25 m apart). Each transect was partitioned into four categories: interior of the matrix; edge of the matrix; edge of the fragment; and interior of the fragment. For each sample site, we measured ant species richness and ant community composition within each transect category. Ant richness and composition differed between fragments and matrices. Each sample location had a specific composition of ants, probably because of the influence of the nature and management of the agricultural matrices. Species composition in the coffee matrix had the highest similarity to its corresponding fragment. The variability in species composition within forest fragments surrounded by pasture was greatest when compared with forest fragments surrounded by sugarcane or, to a lesser extent, coffee. Functional guild composition differed between locations, but the most representative guild was 'generalist' both in the agricultural matrices and forest fragments. Our results are important for understanding how agricultural matrices act on ant communities, and also, how these isolated forest fragments could act as an island of biodiversity in an 'ocean of crops'.

  16. Ternary-fragmentation-driving potential energies of 252Cf

    Science.gov (United States)

    Karthikraj, C.; Ren, Zhongzhou

    2017-12-01

    Within the framework of a simple macroscopic model, the ternary-fragmentation-driving potential energies of 252Cf are studied. In this work, all possible ternary-fragment combinations of 252Cf are generated by the use of atomic mass evaluation-2016 (AME2016) data and these combinations are minimized by using a two-dimensional minimization approach. This minimization process can be done in two ways: (i) with respect to proton numbers (Z1, Z2, Z3) and (ii) with respect to neutron numbers (N1, N2, N3) of the ternary fragments. In this paper, the driving potential energies for the ternary breakup of 252Cf are presented for both the spherical and deformed as well as the proton-minimized and neutron-minimized ternary fragments. From the proton-minimized spherical ternary fragments, we have obtained different possible ternary configurations with a minimum driving potential, in particular, the experimental expectation of Sn + Ni + Ca ternary fragmentation. However, the neutron-minimized ternary fragments exhibit a driving potential minimum in the true-ternary-fission (TTF) region as well. Further, the Q -value energy systematics of the neutron-minimized ternary fragments show larger values for the TTF fragments. From this, we have concluded that the TTF region fragments with the least driving potential and high Q values have a strong possibility in the ternary fragmentation of 252Cf. Further, the role of ground-state deformations (β2, β3, β4, and β6) in the ternary breakup of 252Cf is also studied. The deformed ternary fragmentation, which involves Z3=12 -19 fragments, possesses the driving potential minimum due to the larger oblate deformations. We also found that the ground-state deformations, particularly β2, strongly influence the driving potential energies and play a major role in determining the most probable fragment combinations in the ternary breakup of 252Cf.

  17. The Munich accelerator for fission fragments MAFF

    International Nuclear Information System (INIS)

    Habs, D.; Gross, M.; Assmann, W.; Ames, F.; Bongers, H.; Emhofer, S.; Heinz, S.; Henry, S.; Kester, O.; Neumayr, J.; Ospald, F.; Reiter, P.; Sieber, T.; Szerypo, J.; Thirolf, P.G.; Varentsov, V.; Wilfart, T.; Faestermann, T.; Kruecken, R.; Maier-Komor, P.

    2003-01-01

    The Munich Accelerator for Fission Fragments MAFF has been designed for the new Munich research reactor FRM-II. It will deliver several intense beams (∼3x10 11 s -1 ) of very neutron-rich fission fragments with a final energy of 30 keV (low-energy beam) or energies between 3.7 and 5.9 MeV·A (high-energy beam). Such beams are of interest for the creation of super-heavy elements by fusion reactions, nuclear spectroscopy of exotic nuclei, but they also have a potential for applications, e.g. in medicine. Presently the Munich research reactor FRM-II is ready for operation, but authorities delay the final permission to turn the reactor critical probably till the end of 2002. Only after this final permission the financing of the major parts of MAFF can start. On the other hand all major components have been designed and special components have been tested in separate setups

  18. Inclusive projectile fragmentation in the spectator model

    International Nuclear Information System (INIS)

    Hussein, M.S.; McVoy, K.W.

    1985-01-01

    Crazing-angle single spectra for projectile fragments from nuclear collisions exhibit a broad peak centered near the beam velocity, suggesting that these observed fragments play only a 'spectator' role in the reaction. Using only this spectator assumption (but not DWBA), it is found that a 'prior form' formulation of the reaction leads, via closure, to a -type estimate of the inclusive spectator spectrum, thus relating it to the reaction cross section for the 'participant' with the target. It is shown explicitly that this expression includes an improved multi-channel version of the Udagawa-Tamura formula for the 'breakup-fusion' or incomplete fusion cross section, and identifies it as the fluctuation part of the participant-target reaction cross section. A Glauber-type estimate of the distorted wave functions which enter clearly shows how the width of the peak in the spectator spectrum arises from the 'Fermi motion' within the projectile, as in the simple Serber model, but is modified by the 'overlap geometry' of the collision. (Author) [pt

  19. Alkaline glass as induced fission fragment detectors

    International Nuclear Information System (INIS)

    Amorim, A.M.M.

    1986-01-01

    The slide glass, registered trade marks INLAB, INVICT and PERFECTA were compared. For the three kinds of glasses the following studies were done: chemical composition; general dissolution rate for hydrofluoric acid solutions of concentrations between 1 and 10M, at 30 0 C and ultrasound shaking; relative efficiency for recording fission fragment tracks from 252 Cf. The INLAB glass was selected due to the better quality of its surface after chemical etching. The HF concentration 2.5M was determined for chemical etching of INLAB glass, and the optimum etching time was chosen between 8 and 10 minutes. The thermal attenuation of latent tracks in the environmental temperature was observed for intervals uo to 31 days between the detector exposure to the fission fragment source and etching of tracks. Several methods were used for determining the detector parameters, such as: critical angle, angle of the cone and efficiency of etching. The effects of gamma irradiation from 60 Co and reactor neutrons in material properties as track detector were studied. Attenuation of latent tracks and saturation of color centers were observed for doses over 100M Rad. Since this kind of material contains uranium as impurity, uniformely distributed, slide glass were calibrated to be applied as a monitor of thermal neutron flux in nuclear reactor. (Author) [pt

  20. Improvements to a model of projectile fragmentation

    International Nuclear Information System (INIS)

    Mallik, S.; Chaudhuri, G.; Das Gupta, S.

    2011-01-01

    In a recent paper [Phys. Rev. C 83, 044612 (2011)] we proposed a model for calculating cross sections of various reaction products which arise from disintegration of projectile-like fragments resulting from heavy-ion collisions at intermediate or higher energy. The model has three parts: (1) abrasion, (2) disintegration of the hot abraded projectile-like fragment (PLF) into nucleons and primary composites using a model of equilibrium statistical mechanics, and (3) possible evaporation of hot primary composites. It was assumed that the PLF resulting from abrasion has one temperature T. Data suggested that, while just one value of T seemed adequate for most cross-section calculations, a single value failed when dealing with very peripheral collisions. We have now introduced a variable T=T(b) where b is the impact parameter of the collision. We argue that there are data which not only show that T must be a function of b but, in addition, also point to an approximate value of T for a given b. We propose a very simple formula: T(b)=D 0 +D 1 [A s (b)/A 0 ] where A s (b) is the mass of the abraded PLF and A 0 is the mass of the projectile; D 0 and D 1 are constants. Using this model we compute cross sections for several collisions and compare with data.

  1. Construction of a 3D-shaped, natural product like fragment library by fragmentation and diversification of natural products.

    Science.gov (United States)

    Prescher, Horst; Koch, Guido; Schuhmann, Tim; Ertl, Peter; Bussenault, Alex; Glick, Meir; Dix, Ina; Petersen, Frank; Lizos, Dimitrios E

    2017-02-01

    A fragment library consisting of 3D-shaped, natural product-like fragments was assembled. Library construction was mainly performed by natural product degradation and natural product diversification reactions and was complemented by the identification of 3D-shaped, natural product like fragments available from commercial sources. In addition, during the course of these studies, novel rearrangements were discovered for Massarigenin C and Cytochalasin E. The obtained fragment library has an excellent 3D-shape and natural product likeness, covering a novel, unexplored and underrepresented chemical space in fragment based drug discovery (FBDD). Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. Failure analysis of buried tanks

    International Nuclear Information System (INIS)

    Watkins, R.K.

    1994-01-01

    Failure of a buried tank can be hazardous. Failure may be a leak through which product is lost from the tank; but also through which contamination can occur. Failures are epidemic -- because buried tanks are out of sight, but also because designers of buried tanks have adopted analyses developed for pressure tanks. So why do pressure tanks fail when they are buried? Most failures of buried tanks are really soil failures. Soil compresses, or slips, or liquefies. Soil is not only a load, it is a support without which the tank deforms. A high water table adds to the load on the tank. It also reduces the strength of the soil. Based on tests, structural analyses are proposed for empty tanks buried in soils of various quality, with the water table at various levels, and with internal vacuum. Failure may be collapse tank. Such collapse is a sudden, audible inversion of the cylinder when the sidefill soil slips. Failure may be flotation. Failure may be a leak. Most leaks are fractures in the welds in overlap seams at flat spots. Flat spots are caused by a hard bedding or a heavy surface wheel load. Because the tank wall is double thick at the overlap, shearing stress in the weld is increased. Other weld failures occur when an end plate shears down past a cylinder; or when the tank is supported only at its ends like a beam. These, and other, failures can be analyzed with justifiable accuracy using basic principles of mechanics of materials. 10 figs

  3. Insomnia Self-Management in Heart Failure

    Science.gov (United States)

    2018-01-05

    Cardiac Failure; Heart Failure; Congestive Heart Failure; Heart Failure, Congestive; Sleep Initiation and Maintenance Disorders; Chronic Insomnia; Disorders of Initiating and Maintaining Sleep; Fatigue; Pain; Depressive Symptoms; Sleep Disorders; Anxiety

  4. MaRaCluster: A Fragment Rarity Metric for Clustering Fragment Spectra in Shotgun Proteomics.

    Science.gov (United States)

    The, Matthew; Käll, Lukas

    2016-03-04

    Shotgun proteomics experiments generate large amounts of fragment spectra as primary data, normally with high redundancy between and within experiments. Here, we have devised a clustering technique to identify fragment spectra stemming from the same species of peptide. This is a powerful alternative method to traditional search engines for analyzing spectra, specifically useful for larger scale mass spectrometry studies. As an aid in this process, we propose a distance calculation relying on the rarity of experimental fragment peaks, following the intuition that peaks shared by only a few spectra offer more evidence than peaks shared by a large number of spectra. We used this distance calculation and a complete-linkage scheme to cluster data from a recent large-scale mass spectrometry-based study. The clusterings produced by our method have up to 40% more identified peptides for their consensus spectra compared to those produced by the previous state-of-the-art method. We see that our method would advance the construction of spectral libraries as well as serve as a tool for mining large sets of fragment spectra. The source code and Ubuntu binary packages are available at https://github.com/statisticalbiotechnology/maracluster (under an Apache 2.0 license).

  5. Fission fragment yields from heavy-ion-induced reactions measured with a fragment separator

    Science.gov (United States)

    Tarasov, O. B.; Delaune, O.; Farget, F.; Morrissey, D. J.; Amthor, A. M.; Bastin, B.; Bazin, D.; Blank, B.; Cacéres, L.; Chbihi, A.; Fernández-Dominguez, B.; Grévy, S.; Kamalou, O.; Lukyanov, S. M.; Mittig, W.; Pereira, J.; Perrot, L.; Saint-Laurent, M.-G.; Savajols, H.; Sherrill, B. M.; Stodel, C.; Thomas, J. C.; Villari, A. C.

    2018-04-01

    The systematic study of fission fragment yields under different initial conditions has provided valuable experimental data for benchmarking models of fission product yields. Nuclear reactions using inverse kinematics coupled to the use of a high-resolution spectrometer with good fragment identification are shown here to be a powerful tool to measure the inclusive isotopic yields of fission fragments. In-flight fusion-fission was used in this work to produce secondary beams of neutron-rich isotopes in the collisions of a 238U beam at 24 MeV/u with 9Be and 12C targets at GANIL using the LISE3 fragment separator. Unique identification of the A, Z, and atomic charge state, q, of fission products was attained with the Δ E- TKE-B ρ- ToF measurement technique. Mass, and atomic number distributions are reported for the two reactions. The results show the importance of different reaction mechanisms in the two cases. The optimal target material for higher yields of neutron-rich high- Z isotopes produced in fusion-fission reactions as a function of projectile energy is discussed.

  6. When fragments link : a bibliometric perspective on the development of fragment-based drug discovery

    NARCIS (Netherlands)

    Romasanta, A.K.S.; van der Sijde, P.C.; Hellsten, I.; Hubbard, Roderick E.; Keseru, Gyorgy M.; van Muijlwijk-Koezen, Jacqueline E.; de Esch, I.J.P.

    2018-01-01

    Fragment-based drug discovery (FBDD) is a highly interdisciplinary field, rich in ideas integrated from pharmaceutical sciences, chemistry, biology, and physics, among others. To enrich our understanding of the development of the field, we used bibliometric techniques to analyze 3642 publications in

  7. On the fragmentation of biomolecules: fragmentation of alanine dipeptide along the polypeptide chain

    DEFF Research Database (Denmark)

    Solov'yov, Ilia; Yakubovich, Alexander; Solov'yov, Andrey

    2006-01-01

    The interaction potential between amino acids in alanine dipeptide has been studied for the first time taking into account exact molecular geometry. Ab initio calculation has been performed in the framework of density functional theory taking into account all electrons in the system. The fragment...

  8. An analytical model for interactive failures

    International Nuclear Information System (INIS)

    Sun Yong; Ma Lin; Mathew, Joseph; Zhang Sheng

    2006-01-01

    In some systems, failures of certain components can interact with each other, and accelerate the failure rates of these components. These failures are defined as interactive failure. Interactive failure is a prevalent cause of failure associated with complex systems, particularly in mechanical systems. The failure risk of an asset will be underestimated if the interactive effect is ignored. When failure risk is assessed, interactive failures of an asset need to be considered. However, the literature is silent on previous research work in this field. This paper introduces the concepts of interactive failure, develops an analytical model to analyse this type of failure quantitatively, and verifies the model using case studies and experiments

  9. Forest Fragments Surrounded by Sugar Cane Are More Inhospitable to Terrestrial Amphibian Abundance Than Fragments Surrounded by Pasture

    Directory of Open Access Journals (Sweden)

    Paula Eveline Ribeiro D’Anunciação

    2013-01-01

    Full Text Available In recent years, there has been increasing interest in matrix-type influence on forest fragments. Terrestrial amphibians are good bioindicators for this kind of research because of low vagility and high philopatry. This study compared richness, abundance, and species composition of terrestrial amphibians through pitfall traps in two sets of semideciduous seasonal forest fragments in southeastern Brazil, according to the predominant surrounding matrix (sugar cane and pasture. There were no differences in richness, but fragments surrounded by sugar cane had the lowest abundance of amphibians, whereas fragments surrounded by pastures had greater abundance. The most abundant species, Rhinella ornata, showed no biometric differences between fragment groups but like many other amphibians sampled showed very low numbers of individuals in fragments dominated by sugar cane fields. Our data indicate that the sugar cane matrix negatively influences the community of amphibians present in fragments surrounded by this type of land use.

  10. Component failure data handbook

    International Nuclear Information System (INIS)

    Gentillon, C.D.

    1991-04-01

    This report presents generic component failure rates that are used in reliability and risk studies of commercial nuclear power plants. The rates are computed using plant-specific data from published probabilistic risk assessments supplemented by selected other sources. Each data source is described. For rates with four or more separate estimates among the sources, plots show the data that are combined. The method for combining data from different sources is presented. The resulting aggregated rates are listed with upper bounds that reflect the variability observed in each rate across the nuclear power plant industry. Thus, the rates are generic. Both per hour and per demand rates are included. They may be used for screening in risk assessments or for forming distributions to be updated with plant-specific data

  11. Iridium: failures & successes

    Science.gov (United States)

    Christensen, CarissaBryce; Beard, Suzette

    2001-03-01

    This paper will provide an overview of the Iridium business venture in terms of the challenges faced, the successes achieved, and the causes of the ultimate failure of the venture — bankruptcy and system de-orbit. The paper will address technical, business, and policy issues. The intent of the paper is to provide a balanced and accurate overview of the Iridium experience, to aid future decision-making by policy makers, the business community, and technical experts. Key topics will include the history of the program, the objectives and decision-making of Motorola, the market research and analysis conducted, partnering strategies and their impact, consumer equipment availability, and technical issues — target performance, performance achieved, technical accomplishments, and expected and unexpected technical challenges. The paper will use as sources trade media and business articles on the Iridium program, technical papers and conference presentations, Wall Street analyst's reports, and, where possible, interviews with participants and close observers.

  12. Comparative Failure in Science

    Directory of Open Access Journals (Sweden)

    Barney Glaser, PhD, Hon Phd

    2017-06-01

    Full Text Available A perennial problem for some scientists is their feeling of comparative failure as scientists. This problem becomes clearer if we consider two major sources of this feeling that are inherent in the vary nature of scientific work. (i In science, strong emphasis is placed on the achievement of recognition; (ii the typical basic scientist works in a community filled with “great men” who have made important and decisive discoveries in their respective fields; they are the acknowledge guiding lights. These esteemed scientists, who have attained honors beyond the reach of most of their colleagues, tend to become models for those who have been trained by them or who have worked under them. As Eiduson has put it in her recent psychological study of basic research scientists “Scientists: are idols-oriented.”

  13. Comparative Failure in Science

    Directory of Open Access Journals (Sweden)

    Barney G. Glaser, Ph.D., Hon. Ph.D

    2008-03-01

    Full Text Available A perennial problem for some scientists is their feeling of comparative failure as scientists. This problem becomes clearer if we consider two major sources of this feeling that are inherent in the vary nature of scientific work. (i In science, strong emphasis is placed on the achievement of recognition; (ii the typical basic scientist works in a community filled with “great men” who have made important and decisive discoveries in their respective fields; they are the acknowledge guiding lights. These esteemed scientists, who have attained honors beyond the reach of most of their colleagues, tend to become models for those who have been trained by them or who have worked under them. As Eiduson has put it in her recent psychological study of basic research scientists “Scientists: are idols-oriented.”

  14. Premature ovarian failure

    Directory of Open Access Journals (Sweden)

    Vujović Svetlana

    2012-01-01

    Full Text Available Premature ovarian failure (POF is the occurrence of hypergonadotropic hypoestrogenic amenorrhea in women under the age of forty years. It is idiopathic in 74-90% patients. Known cases can be divided into primary and secondary POF. In primary POF genetic aberrations can involve the X chromosome (monosomy, trisomy, translocations, deletions or autosomes. Genetic mechanisms include reduced gene dosage and non-specific chromosome effects impairing meiosis, decreasing the pool of primordial follicles and increasing atresia due to apoptosis or failure of follicle maturation. Autoimmune ovarian damage is caused by alteration of T-cell subsets and T-cell mediated injury, increase of autoantibody producing B-cells, a low number of effector/cytotoxic lymphocyte, which decreases the number and activity of natural killer cells. Bilateral oophorectomy, chemotherapy, radiotherapy and infections cause the secondary POF. Symptoms of POF include irritability, nervousness, loss of libido, depression, lack of concentration, hot flushes, weight gaining, dry skin, vaginal dryness, frequent infections etc. The diagnosis is confirmed by the level of FSH of over 40 IU/L and estradiol below 50 pmol/L in women aged below 40 years. Biochemical and other hormonal analysis (free thyroxin, TSH, prolactin, testosterone, karyotype (<30 years of age, ultrasound of the breasts and pelvis are advisable. Optimal therapy is combined estrogen progestagen therapy given in a sequential rhythm, after excluding absolute contraindications. Testosterone can be added to adnexectomized women and those with a low libido. Sequential estrogen progestagen replacement therapy is the first line therapy for ovulation induction in those looking for pregnancy and after that oocyte donation will be advised. Appropriate estro-progestagen therapy improves the quality of life and prevents complications such as cardiovascular diseases, osteoporosis, stroke etc.

  15. Vitamin D and Heart Failure.

    Science.gov (United States)

    Marshall Brinkley, D; Ali, Omair M; Zalawadiya, Sandip K; Wang, Thomas J

    2017-10-01

    Vitamin D is principally known for its role in calcium homeostasis, but preclinical studies implicate multiple pathways through which vitamin D may affect cardiovascular function and influence risk for heart failure. Many adults with cardiovascular disease have low vitamin D status, making it a potential therapeutic target. We review the rationale and potential role of vitamin D supplementation in the prevention and treatment of chronic heart failure. Substantial observational evidence has associated low vitamin D status with the risk of heart failure, ventricular remodeling, and clinical outcomes in heart failure, including mortality. However, trials assessing the influence of vitamin D supplementation on surrogate markers and clinical outcomes in heart failure have generally been small and inconclusive. There are insufficient data to recommend routine assessment or supplementation of vitamin D for the prevention or treatment of chronic heart failure. Prospective trials powered for clinical outcomes are warranted.

  16. Fragger: a protein fragment picker for structural queries.

    Science.gov (United States)

    Berenger, Francois; Simoncini, David; Voet, Arnout; Shrestha, Rojan; Zhang, Kam Y J

    2017-01-01

    Protein modeling and design activities often require querying the Protein Data Bank (PDB) with a structural fragment, possibly containing gaps. For some applications, it is preferable to work on a specific subset of the PDB or with unpublished structures. These requirements, along with specific user needs, motivated the creation of a new software to manage and query 3D protein fragments. Fragger is a protein fragment picker that allows protein fragment databases to be created and queried. All fragment lengths are supported and any set of PDB files can be used to create a database. Fragger can efficiently search a fragment database with a query fragment and a distance threshold. Matching fragments are ranked by distance to the query. The query fragment can have structural gaps and the allowed amino acid sequences matching a query can be constrained via a regular expression of one-letter amino acid codes. Fragger also incorporates a tool to compute the backbone RMSD of one versus many fragments in high throughput. Fragger should be useful for protein design, loop grafting and related structural bioinformatics tasks.

  17. Anisotropy in highly charged ion induced molecule fragmentation

    International Nuclear Information System (INIS)

    Juhasz, Z.; Sulik, B.; Fremont, F.; Chesnel, J.Y.; Hajaji, A.

    2006-01-01

    Complete text of publication follows. Studying fragmentation processes of biologically relevant molecules due to highly charged ion impact is important to understand radiation damage in biological tissues. Energy spectra of the charged molecule fragments may reveal the different fragmentation patterns meanwhile the angular distributions of the fragments characterize the dependence of fragmentation probability on the initial orientation of the molecule. The research to explore the angular distribution of the molecule fragments has only recently been started[1]. In 2006 we performed measurements at ARIBE facility at GANIL, Caen (France), in order to investigate orientation effects in molecule fragmentation. Fragmentation of H 2 O, C 6 H 6 and CH 4 , which represent different level of symmetry, have been studied by 60 keV N 6+ ion impact. Energy spectra of the charged fragments at different observation angles have been taken. As our example spectra show the different protonic peaks can be attributed to different fragmentation processes. Significant anisotropy can be seen in the different processes. The strongest evidence for the anisotropy can be seen in the spectra of C 6 H 6 , where the spectra appear isotropic in almost the whole observed energy range except one peak, which has a strong angular dependence and is maximal around 90 deg. (author)

  18. Microbial platform technology for recombinant antibody fragment production: A review.

    Science.gov (United States)

    Gupta, Sanjeev Kumar; Shukla, Pratyoosh

    2017-02-01

    Recombinant antibody fragments are being used for the last few years as an important therapeutic protein to cure various critical and life threatening human diseases. Several expression platforms now days employed for the production of these recombinant fragments, out of which bacterial system has emerged a promising host for higher expression. Since, a small antibody fragment unlike full antibody does not require human-like post-translational modification therefore it is potentially expressed in prokaryotic production system. Recently, small antibody fragments such as scFvs (single-chain variable fragments) and Fabs (antibody fragments) which does not require glycosylation are successfully produced in bacteria and have commercially launched for therapeutic use as these fragments shows better tissue penetration and less immunogenic to human body compared to full-size antibody. Recently developed Wacker's ESETEC secretion technology is an efficient technology for the expression and secretion of the antibody fragment (Fab) exceeded up to 4.0 g/L while scFv up to 3.5 g/L into the fermentation broth. The Pfenex system and pOP prokaryotic expression vector are another platform used for the considerably good amount of antibody fragment production successfully. In this review, we summarize the recent progress on various expression platforms and cloning approaches for the production of different forms of antibody fragments in E. coli.

  19. Physics-Based Fragment Acceleration Modeling for Pressurized Tank Burst Risk Assessments

    Science.gov (United States)

    Manning, Ted A.; Lawrence, Scott L.

    2014-01-01

    As part of comprehensive efforts to develop physics-based risk assessment techniques for space systems at NASA, coupled computational fluid and rigid body dynamic simulations were carried out to investigate the flow mechanisms that accelerate tank fragments in bursting pressurized vessels. Simulations of several configurations were compared to analyses based on the industry-standard Baker explosion model, and were used to formulate an improved version of the model. The standard model, which neglects an external fluid, was found to agree best with simulation results only in configurations where the internal-to-external pressure ratio is very high and fragment curvature is small. The improved model introduces terms that accommodate an external fluid and better account for variations based on circumferential fragment count. Physics-based analysis was critical in increasing the model's range of applicability. The improved tank burst model can be used to produce more accurate risk assessments of space vehicle failure modes that involve high-speed debris, such as exploding propellant tanks and bursting rocket engines.

  20. A Failure Criterion for Concrete

    DEFF Research Database (Denmark)

    Ottosen, N. S.

    1977-01-01

    A four-parameter failure criterion containing all the three stress invariants explicitly is proposed for short-time loading of concrete. It corresponds to a smooth convex failure surface with curved meridians, which open in the negative direction of the hydrostatic axis, and the trace in the devi......A four-parameter failure criterion containing all the three stress invariants explicitly is proposed for short-time loading of concrete. It corresponds to a smooth convex failure surface with curved meridians, which open in the negative direction of the hydrostatic axis, and the trace...

  1. Strategies of learning from failure.

    Science.gov (United States)

    Edmondson, Amy C

    2011-04-01

    Many executives believe that all failure is bad (although it usually provides Lessons) and that Learning from it is pretty straightforward. The author, a professor at Harvard Business School, thinks both beliefs are misguided. In organizational life, she says, some failures are inevitable and some are even good. And successful learning from failure is not simple: It requires context-specific strategies. But first leaders must understand how the blame game gets in the way and work to create an organizational culture in which employees feel safe admitting or reporting on failure. Failures fall into three categories: preventable ones in predictable operations, which usually involve deviations from spec; unavoidable ones in complex systems, which may arise from unique combinations of needs, people, and problems; and intelligent ones at the frontier, where "good" failures occur quickly and on a small scale, providing the most valuable information. Strong leadership can build a learning culture-one in which failures large and small are consistently reported and deeply analyzed, and opportunities to experiment are proactively sought. Executives commonly and understandably worry that taking a sympathetic stance toward failure will create an "anything goes" work environment. They should instead recognize that failure is inevitable in today's complex work organizations.

  2. Submersion and acute respiratory failure

    Directory of Open Access Journals (Sweden)

    Yu-Jang Su

    2014-01-01

    Conclusions: Submersion patients who are hypothermic on arrival of emergency department (ED are risky to respiratory failure and older, more hypothermic, longer hospital stay in suicidal submersion patients.

  3. Assessment of trochanteric osteotomy fragment union after acetabular fracture surgery.

    Science.gov (United States)

    Dubina, Andrew G; Wickramaratne, Niluka; O'Toole, Robert V; Manson, Theodore T

    2017-02-01

    Trochanteric osteotomies are performed in conjunction with standard approaches to improve surgical exposure during open reduction and internal fixation (ORIF) of acetabular fractures. The literature on total hip arthroplasty reports nonunion rates as high as 30% associated with trochanteric osteotomies; however, few data exist regarding the outcomes of trochanteric osteotomies for acetabular fracture surgery. Our hypotheses were 1) patients receiving trochanteric osteotomies during ORIF of acetabular fractures have a low rate of nonunion of the osteotomy fragment, and 2) hip abduction precautions are not necessary with digastric type osteotomies. A retrospective review was conducted to identify patients with acetabular fractures between July 2002 and June 2010 (n=734 fractures) who required trochanteric osteotomies (n=64, 9% of fractures). Forty-seven met inclusion criteria of adequate follow-up (>56days). No excluded patient experienced a complication. Fractures were classified using the Letournel-Judet classification system. Only seven (20%) of 35 patients who received digastric osteotomies had hip abduction precautions applied during the postoperative period. All study patients were shown to have radiographic union at the trochanteric osteotomy site (100% union rate, n=47). Hip abduction precautions intended to protect the osteotomy site and reduce the risk of nonunion and fixation failure were infrequently applied to patients with digastric osteotomies (20%) in this cohort. Multiple protective factors against nonunion were present in this study population compared with previous arthroplasty studies from other institutions. Trochanteric osteotomies are not associated with a significant nonunion rate, and digastric osteotomies might be safely managed without hip abduction precautions. Copyright © 2016. Published by Elsevier Ltd.

  4. Deciding Security for a Fragment of ASLan

    DEFF Research Database (Denmark)

    Mödersheim, Sebastian Alexander

    2012-01-01

    situations in security such as the interaction between the workflow of a system with its access control policies. While even the transition relation is undecidable for ASLan in general, we show the security problem is decidable for a large and useful fragment that we call TASLan, as long as we bound......ASLan is the input language of the verification tools of the AVANTSSAR platform, and an extension of the AVISPA Intermediate Format IF. One of ASLan's core features over IF is to integrate a transition system with Horn clauses that are evaluated at every state. This allows for modeling many common...... the number of steps of honest participants. The restriction of TASLan is that all messages and predicates must be in a certain sense unambiguous in their interpretation, excluding “type-confusions” similar to some tagging results for security protocols....

  5. A semiclassical model for quark jet fragmentation

    International Nuclear Information System (INIS)

    Andersson, B.; Gustafson, G.; Peterson, C.

    1979-01-01

    A semiclassical model is presented for the way the energy of a fast quark is transformed into observable hadrons. It reproduces the features of 1+1 dimensional QED (the Schwinger model) concerning a flat rapidity distribution in the central region. It also reproduces results from phenomenological considerations, which, based upon scaling, predict that meson formation in the fragmentation region can be described by an iterative scheme, implying a set of coupled integral equations. In particular the model predicts that the probability to find a meson containing the leading quark is independent of the Feynman scaling variable z. The iterative structure corresponds to a Brownian motion with relevance both to the cofinement problems and to the distribution of mass in the quark jet. (orig.) [de

  6. Characterization of IFR metal fuel fragmentation

    International Nuclear Information System (INIS)

    Gabor, J.D.; Purviance, R.T.; Aeschlimann, R.W.; Spencer, B.W.

    1987-01-01

    The integral fast reactor (IFR) employs a reactor design that has inherent safety features. An important safety advantage is derived from its pool configuration, which facilitates passive decay heat removal and isolates the core from accidents that might occur elsewhere in the plant. The metal-alloy fuel has superior heat transfer properties compared to oxide fuels. While the IFR design has these inherent safety features, a complete analysis of reactor safety requires assessment of the consequences of the melting of the uranium alloy fuel in the core and the contact of molten core materials with sodium. A series of eight tests was conducted in which the fragmentation and interaction behavior of kilogram quantities of uranium-zirconium alloy in sodium was studied

  7. FLORULA URBAN FRAGMENT OF TROPICAL DRY FOREST

    Directory of Open Access Journals (Sweden)

    Willington Barranco-Pérez

    2016-01-01

    Full Text Available The aim of this study was to record the composition of plant species in an urban fragment of tropical dry forest of secondary regeneration (bs-T to generate information that can be used in the planning and management of green spaces in the city of Santa Marta. Transects of 2 x 50 m were established equivalent to 0.1 ha and all species were counted >1.0 cm DBH (Diameter at Breast Height: 1.3m. 100 species of angiosperms were recorded of which 47% have herbaceous habit. The number of species recorded in this study represents 39.6% of the species reported for the hills of Santa Marta and 3.8% for the dry forests of Colombia. It is suggested to isolate this type of secondary formations of any intervention and contemplate the reintroduction of individuals and conservation strategies.

  8. Couleur de temps, fragments d’histoires.

    Directory of Open Access Journals (Sweden)

    Daniel Russo

    2003-12-01

    Full Text Available Exposition « Couleur de temps, fragments d’histoires : XIIe-XXe siècles », Dijon, Musée Archéologique, 20 juin-2 novembre 2003Le travail est le résultat d’une collaboration entre l’Université, les Services de l’Inventaire, le Musée Archéologique et l’“Association Patrimoine Ambiance et Couleurs en Bourgogne”. Dix ans après l’exposition “D’ocre et d’Azur”, en 1992, et la parution du catalogue, il était opportun de revenir sur les découvertes et les redécouvertes de peintures murales en Bourgog...

  9. Fragmentation Pathways of Lithiated Hexose Monosaccharides

    Science.gov (United States)

    Abutokaikah, Maha T.; Frye, Joseph W.; Tschampel, John; Rabus, Jordan M.; Bythell, Benjamin J.

    2018-05-01

    We characterize the primary fragmentation reactions of three isomeric lithiated D-hexose sugars (glucose, galactose, and mannose) utilizing tandem mass spectrometry, regiospecific labeling, and theory. We provide evidence that these three isomers populate similar fragmentation pathways to produce the abundant cross-ring cleavage peaks (0,2A1 and 0,3A1). These pathways are highly consistent with the prior literature (Hofmeister et al. J. Am. Chem. Soc. 113, 5964-5970, 1991, Bythell et al. J. Am. Soc. Mass Spectrom. 28, 688-703, 2017, Rabus et al. Phys. Chem. Chem. Phys. 19, 25643-25652, 2017) and the present labeling data. However, the structure-specific energetics and rate-determining steps of these reactions differ as a function of precursor sugar and anomeric configuration. The lowest energy water loss pathways involve loss of the anomeric oxygen to furnish B1 ions. For glucose and galactose, the lithiated α-anomers generate ketone structures at C2 in a concerted reaction involving a 1,2-migration of the C2-H to the anomeric carbon (C1). In contrast, the β-anomers are predicted to form 1,3-anhydroglucose/galactose B1 ion structures. Initiation of the water loss reactions from each anomeric configuration requires distinct reactive conformers, resulting in different product ion structures. Inversion of the stereochemistry at C2 has marked consequences. Both lithiated mannose forms expel water to form 1,2-anhydromannose B1 ions with the newly formed epoxide group above the ring. Additionally, provided water loss is not instantaneous, the α-anomer can also isomerize to generate a ketone structure at C2 in a concerted reaction involving a 1,2-migration of the C2-H to C1. This product is indistinguishable to that from α-glucose. The energetics and interplay of these pathways are discussed. [Figure not available: see fulltext.

  10. Quantum Correlated Multi-Fragment Reaction Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Feagin, James M. [California State Univ., Fullerton, CA (United States)

    2017-06-30

    This grant supported research in basic atomic, molecular and optical physics related to the interactions of atoms with particles and fields. This report will focus on the 12 year period from 2004 to 2017, although the DOE–BES has supported my research every year since 1986. All of the support from the grant was used to pay summer salaries of the PI and students and travel to conferences and meetings. The results were in the form of publications in peer reviewed journals as well as conference invited talks and colloquiums. There were 12 peer reviewed publications in these 12+ years. Innovations in few-body science at molecular and nano levels are a critical component of on- going efforts to establish sustainable environmental and energy resources. The varied research paths taken will require the development of basic science on broad fronts with increasing flexi- bility to crossover technologies. We thus worked to extract understanding and quantum control of few-body microscopic systems based on our long-time experience with more conventional studies of correlated electrons and ions. Given the enormous advances over the past 20 years to our understanding of quantum cor- relations with photon interferometry, AMO collision science generally is ready to move beyond the one-particle, single-port momentum detection that has dominated collision physics since Rutherford. Nevertheless, our familiar theoretical tools for collision theory need to be up- graded to incorporate these more generalized measurement formalisms and ultimately to give incentive for a new generation of experiments. Our interest in these topics remains motivated by the recent surge in and success of exper- iments involving few-body atomic and molecular fragmentation and the detection of all the fragments. The research described here thus involved two parallel efforts with (i) emphasis on reaction imaging while (ii) pursuing longtime work on quantum correlated collective excitations.

  11. Rockfall failure mechanisms in Yosemite Valley, California (USA)

    Science.gov (United States)

    Matasci, Battista; Guerin, Antoine; Carrea, Dario; Stock, Greg M.; Jaboyedoff, Michel; Collins, Brian

    2014-05-01

    Rockfall hazard is especially high in Yosemite Valley, with tens of rockfalls inventoried every year. A rockfall on 5 October 2013 from Ahwiyah Point consisted of a volume of 740 cubic meters and occurred within the perimeter of a larger event on 28 March 2009 that released 25'400 cubic meters of rock (Zimmer et al., 2012). In both events (2009 and 2013), the initial rockfall volumes dislodged a second one approximately equivalent in size by impacting the cliff below the source area during the fall. Rock fragments of up to several cubic meters were deposited on the talus slope, damaging a heavily used and recently reconstructed hiking path. We performed extensive mapping of structural features for several cliffs of Yosemite Valley to improve the assessment of the most susceptible rockfall areas. In particular we mapped and characterized the main brittle structures, the exfoliation joints and the failure mechanisms of the past rockfalls. Several failure mechanisms exist in Yosemite including the propagation of brittle structures that may lead to tensile, planar sliding, wedge sliding or toppling failures. Frequently, topographically-parallel exfoliation joints and topographically-oblique discontinuities coexist, resulting in complex failures. We also developed a methodology to examine how the distribution of joints within the cliff faces of Yosemite Valley affects overall stability with respect to the identified failure mechanisms. For these analyses, we used terrestrial laser scanning (TLS) to collect high resolution point clouds of the vertical and overhanging rock faces throughout the Valley. This provided the necessary 3D data to identify the main joint sets, perform spacing and trace length measurements, and calculate volumes of previous and potential rockfalls. We integrated this information with stability calculations to identify the likely failure mechanisms for each area of cliff and to obtain the number of potential failures per square meter of cliff face

  12. Public Choice, Market Failure, and Government Failure in Principles Textbooks

    Science.gov (United States)

    Fike, Rosemarie; Gwartney, James

    2015-01-01

    Public choice uses the tools of economics to analyze how the political process allocates resources and impacts economic activity. In this study, the authors examine twenty-three principles texts regarding coverage of public choice, market failure, and government failure. Approximately half the texts provide coverage of public choice and recognize…

  13. Comparing Learning from Productive Failure and Vicarious Failure

    Science.gov (United States)

    Kapur, Manu

    2014-01-01

    A total of 136 eighth-grade math students from 2 Singapore schools learned from either productive failure (PF) or vicarious failure (VF). PF students "generated" solutions to a complex problem targeting the concept of variance that they had not learned yet before receiving instruction on the targeted concept. VF students…

  14. Corrosion failure analysis as related to prevention of corrosion failures

    International Nuclear Information System (INIS)

    Suss, H.

    1977-10-01

    The factors and conditions which have contributed to many of the corrosion related service failures are discussed based on a review of actual case histories. The anti-corrosion devices which developed as a result of these failure analyses are reviewed, and the method which must be adopted and used to take advantage of the available corrosion prevention techniques is discussed

  15. arXiv Generalized Fragmentation Functions for Fractal Jet Observables

    CERN Document Server

    Elder, Benjamin T.; Thaler, Jesse; Waalewijn, Wouter J.; Zhou, Kevin

    2017-06-15

    We introduce a broad class of fractal jet observables that recursively probe the collective properties of hadrons produced in jet fragmentation. To describe these collinear-unsafe observables, we generalize the formalism of fragmentation functions, which are important objects in QCD for calculating cross sections involving identified final-state hadrons. Fragmentation functions are fundamentally nonperturbative, but have a calculable renormalization group evolution. Unlike ordinary fragmentation functions, generalized fragmentation functions exhibit nonlinear evolution, since fractal observables involve correlated subsets of hadrons within a jet. Some special cases of generalized fragmentation functions are reviewed, including jet charge and track functions. We then consider fractal jet observables that are based on hierarchical clustering trees, where the nonlinear evolution equations also exhibit tree-like structure at leading order. We develop a numeric code for performing this evolution and study its phen...

  16. Land reform and land fragmentation in Central and Eastern Europe

    DEFF Research Database (Denmark)

    Hartvigsen, Morten B.

    2014-01-01

    It has often been stated that land fragmentation and farm structures characterized by small agricultural holdings and farms divided in a large number of parcels have been the side-effect of land reform in Central and Eastern Europe. This article reports the findings of a study of land reform in 25...... countries in the region from 1989 and onwards and provides an overview of applied land reform approaches. With a basis in theory on land fragmentation, the linkage between land reform approaches and land fragmentation is explored. It is discussed in which situations land fragmentation is a barrier...... for the development of the agricultural and rural sector. The main finding is that land fragmentation is often hampering agricultural and rural development when both land ownership and land use is highly fragmented....

  17. Effective Fragmentation and Flyrock Control Strategies at Quarries

    Directory of Open Access Journals (Sweden)

    Sedat Esen

    2017-01-01

    Full Text Available This paper presents the effective fragmentation and flyrock control strategies that could be applied at quarries to improve the productivity and safety. Fragmentation measurement and modelling as well as a comprehensive drill and blast audit are essential for improving the fragmentation. Face profiling and bore tracking are good tools to manage the ―as-designed‖ and ―as-drilled‖ conditions to get reasonable fragmentation from face burden zone and minimise the flyrock risk. In general, a large scatter in fragmentation data was observed at sites and the causes should be analysed by a detailed root-cause analysis technique. Two case studies were presented in this paper showing some of the effective fragmentation strategies. Finally, a flyrock model was shown to determine the safe blast exclusion zone for the mining equipment and personnel. Some key guidelines were suggested to minimise the occurrence of the flyrock.

  18. Fragmentation of dimethyl ether in femtosecond intense field

    Science.gov (United States)

    Zhu, Jingyi; Guo, Wei; Wang, Yanqiu; Wang, Li

    2006-08-01

    The fragmentation of dimethyl ether (DME) in intense femtosecond laser field has been studied at 810, 405 and 270 nm with intensities up to 2.48 × 10 15, 3.86 × 10 15 and 1.62 × 10 14 W/cm 2, respectively. At 405 nm, DME is possibly firstly ionized by multiphoton absorption, and then parent ion DME + dissociates into fragments via filed-induced dissociation. For 810 and 270 nm laser fields, DME firstly dissociates into CH 3O and CH 3 fragments and then these neutral fragments are ionized by field tunneling. Another possible way for DME to dissociate at 810 and 270 nm is that DME is ionized by intense field ejection of inner valance electron and then the excited DME + dissociates into fragment ions. Ultrafast rearrangement of DME or DME + in intense field may be responsible to the unpredictable fragment ions, CHO+/C2H5+andH2+.

  19. On the application of gluon to heavy quarkonium fragmentation function

    International Nuclear Information System (INIS)

    Qi Wei; Wang Jianxiong

    2007-01-01

    We analyze the uncertainties induced by different definitions of the momentum fraction z in the application of gluon to heavy quarkonium fragmentation function. We numerically calculate the initial g→J/ψ fragmentation functions by using the non-covariant definitions of z with finite gluon momentum and find that these fragmentation functions have strong dependence on the gluon momentum k. As |k|→∞, these fragmentation functions approach to the fragmentation function in the light-cone definition. We find that when |k| is small (for instance in the typical energy scale (about 4-20GeV) of the gluon production at the hadron colliders, such as Tevatron and LHC), large uncertainty remains while the in-covariant definitions of z are employed in the application of the fragmentation functions. (authors)

  20. Public Values in Water Law: A Case of Substantive Fragmentation?

    OpenAIRE

    Ambrus, Monika; Gilissen, Herman Kasper; van Kempen, Jasper JH

    2014-01-01

    Horizontal fragmentation, from a public-values perspective, is a quite well-documented phenomenon in international (water) law. However, the literature does not provide any insight into vertical or substantive fragmentation, i.e. differences in the protection of public values at the various institutional levels. This article assesses whether there is substantive fragmentation in water law at the international, the European, the sub-regional (Danube River Basin), and the Dutch domestic level. ...

  1. Critical Features of Fragment Libraries for Protein Structure Prediction.

    Science.gov (United States)

    Trevizani, Raphael; Custódio, Fábio Lima; Dos Santos, Karina Baptista; Dardenne, Laurent Emmanuel

    2017-01-01

    The use of fragment libraries is a popular approach among protein structure prediction methods and has proven to substantially improve the quality of predicted structures. However, some vital aspects of a fragment library that influence the accuracy of modeling a native structure remain to be determined. This study investigates some of these features. Particularly, we analyze the effect of using secondary structure prediction guiding fragments selection, different fragments sizes and the effect of structural clustering of fragments within libraries. To have a clearer view of how these factors affect protein structure prediction, we isolated the process of model building by fragment assembly from some common limitations associated with prediction methods, e.g., imprecise energy functions and optimization algorithms, by employing an exact structure-based objective function under a greedy algorithm. Our results indicate that shorter fragments reproduce the native structure more accurately than the longer. Libraries composed of multiple fragment lengths generate even better structures, where longer fragments show to be more useful at the beginning of the simulations. The use of many different fragment sizes shows little improvement when compared to predictions carried out with libraries that comprise only three different fragment sizes. Models obtained from libraries built using only sequence similarity are, on average, better than those built with a secondary structure prediction bias. However, we found that the use of secondary structure prediction allows greater reduction of the search space, which is invaluable for prediction methods. The results of this study can be critical guidelines for the use of fragment libraries in protein structure prediction.

  2. Habitat connectivity and fragmented nuthatch populations in agricultural landscapes

    OpenAIRE

    Langevelde, van, F.

    1999-01-01

    In agricultural landscapes, the habitat of many species is subject to fragmentation. When the habitat of a species is fragmented and the distances between patches of habitat are large relative to the movement distances of the species, it can be expected that the degree of habitat connectivity affects processes at population and individual level. In this thesis, I report on a study of effects of habitat fragmentation and opportunities to mitigate these effects by planning ecological n...

  3. RECOVERY OF DOCUMENT TEXT FROM TORN FRAGMENTS USING IMAGE PROCESSING

    OpenAIRE

    C.Prasad; Dr.Mahesh; Dr.S.A.K. Jilani

    2016-01-01

    Recovery of document from its torn or damaged fragments play an important role in the field of forensics and archival study. Reconstruction of the torn papers manually with the help of glue and tapes etc., is tedious, time consuming and not satisfactory. For torn images reconstruction we go for image mosaicing, where we reconstruct the image using features (corners) and RANSAC with homography.But for the torn fragments there is no such similarity portion between fragments. Hence we propose a ...

  4. Observation for really cold fragmentation of heavy nucleus

    International Nuclear Information System (INIS)

    Goverdovskij, A.A.; Ketlerov, V.V.; Mitrofanov, V.F.; Ostapenko, Yu.B.; Khryachkov, V.A.

    1998-01-01

    The results of the detailed study on mass-energy charged correlations of the thorium-232 fission fragments, produced by the 5 MeV neutrons are presented. The event of the thorium nucleus really cold fragmentation into tellurium-134 and strontium-99 at the basic quantum states is identified. It is shown that the whole reaction energy is exhausted by the motion kinetic energy of the fragments in the mutual field

  5. Structural mechanisms of photoeffect in polyimide structures containing heterocyclic fragments

    International Nuclear Information System (INIS)

    Aleksandrova, E. L.

    2006-01-01

    Trends in the variation in the quantum yields of charge-carrier photogeneration in polyimide structures containing heterocyclic fragments are studied. It is shown that the efficiency of sensitization of polyimides depends on the donor and acceptor properties of the fragments of monomeric units of the polyimide. It is established that the range of spectral sensitivity for heterocyclic fragments representing intramolecular complexes with charge transport is wider than that for heterocycles that do not represent such complexes

  6. Heart failure report

    Directory of Open Access Journals (Sweden)

    Pamila Dua

    2015-01-01

    Full Text Available Despite advancements in diagnosis and pharmacotherapy, heart failure (HF remains as a major health problem. The prevalence in the general population is estimated to range from 0.3% to 2.0%, increases considerably with age, and approximately doubles with every additional decade of life. In the last two decades, hospital admission rates for HF have increased steadily. The prevalence of HF can be estimated at 1–2% in the Western world and the incidence approaches 5–10/1000 persons/year. Estimates of the occurrence of HF in the developing world are largely absent. In a recent US population-based study, the prevalence of HF was 2.2% (95 confidence interval 1.6–2.8%, increasing from 0.7% in persons aged 45 through 54 years to 8.4% for those aged 75 years or older. In this article, we look at the major papers published in HF in the past 1 year.

  7. Failure to recall.

    Science.gov (United States)

    Laming, Donald

    2009-01-01

    Mathematical analysis shows that if the pattern of rehearsal in free-recall experiments (of necessity, the pattern observed when participants rehearse aloud) be continued without any further interruption by stimuli (as happens during recall), it terminates with the retrieval of the same 1 word over and over again. Such a terminal state is commonly reached before some of the words in the list have been retrieved even once; those words are not recalled. The 1 minute frequently allowed for recall in free-recall experiments is ample time for retrieval to seize up in this way. The author proposes a model that represents the essential features of the pattern of rehearsal; validates that model by reference to the overt rehearsal data from B. B. Murdock, Jr., and J. Metcalfe (1978) and the recall data from B. B. Murdock, Jr., and R. Okada (1970); demonstrates the long-term properties of continued sequences of retrievals and, also, a fundamental relation linking recall to the total time of presentation; and, finally, compares failure to recall in free-recall experiments with forgetting in general.

  8. Adult intestinal failure

    Energy Technology Data Exchange (ETDEWEB)

    Davidson, J., E-mail: Jdavidson@doctors.org.u [Salford Royal Hospital, Salford (United Kingdom); Plumb, A.; Burnett, H. [Salford Royal Hospital, Salford (United Kingdom)

    2010-05-15

    Intestinal failure (IF) is the inability of the alimentary tract to digest and absorb sufficient nutrition to maintain normal fluid balance, growth, and health. It commonly arises from disease affecting the mesenteric root. Although severe IF is usually managed in specialized units, it lies at the end of a spectrum with degrees of nutritional compromise being widely encountered, but commonly under-recognized. Furthermore, in the majority of cases, the initial enteric insult occurs in non-specialist IF centres. The aim of this article is to review the common causes of IF, general principles of its management, some commoner complications, and the role of radiology in the approach to a patient with severe IF. The radiologist has a crucial role in helping provide access for feeding solutions (both enteral and parenteral) and controlling sepsis (via drainage of collections) in an initial restorative phase of treatment, whilst simultaneously mapping bowel anatomy and quality, and searching for disease complications to assist the clinicians in planning a later, restorative phase of therapy.

  9. Oral lead bullet fragment exposure in northern bobwhite (Colinus virginianus).

    Science.gov (United States)

    Kerr, Richard; Holladay, Jeremy; Holladay, Steven; Tannenbaum, Lawrence; Selcer, Barbara; Meldrum, Blair; Williams, Susan; Jarrett, Timothy; Gogal, Robert

    2011-11-01

    Lead (Pb) is a worldwide environmental contaminant known to adversely affect multiple organ systems in both mammalian and avian species. In birds, a common route of exposure is via oral ingestion of lead particles. Data are currently lacking for the retention and clearance of Pb bullet fragments in gastrointestinal (GI) tract of birds while linking toxicity with blood Pb levels. In the present study, northern bobwhite quail fed a seed-based diet were orally gavaged with Pb bullet fragments (zero, one or five fragments/bird) and evaluated for rate of fragment clearance, and changes in peripheral blood, renal, immune, and gastrointestinal parameters. Based on radiographs, the majority of the birds cleared or absorbed the fragments by seven days, with the exception of one five-fragment bird which took between 7 and 14 days. Blood Pb levels were higher in males than females, which may be related to egg production in females. In males but not females, feed consumption, body weight gain, packed cell volume (PCV), plasma protein concentration, and δ-aminolevulinic acid dehydratase (δ-ALAD) activity were all adversely affected by five Pb fragments. Birds of both sexes that received a single Pb fragment displayed depressed δ-ALAD, suggesting altered hematologic function, while all birds dosed with five bullet fragments exhibited greater morbidity.

  10. The split comets: gravitational interaction between the fragments

    International Nuclear Information System (INIS)

    Sekanina, Z.

    1979-01-01

    The n-body computer program by Schubart and Stumpff (1966) has been slightly modified to study the gravitational interaction between two fragments of a split comet nucleus in the sun's gravitational field. All calculations refer to the orbit of Comet West (1976 VI), the velocity of separation of the fragments is assumed to be equal in magnitude to the velocity of escape from the parent nucleus, and the numerical integration of the relative motion of one fragment (called the companion) with respect to the other (principal fragment) is carried over the period of 200 days from separation. (Auth.)

  11. Quantitative experimental modelling of fragmentation during explosive volcanism

    Science.gov (United States)

    Thordén Haug, Ø.; Galland, O.; Gisler, G.

    2012-04-01

    Phreatomagmatic eruptions results from the violent interaction between magma and an external source of water, such as ground water or a lake. This interaction causes fragmentation of the magma and/or the host rock, resulting in coarse-grained (lapilli) to very fine-grained (ash) material. The products of phreatomagmatic explosions are classically described by their fragment size distribution, which commonly follows power laws of exponent D. Such descriptive approach, however, considers the final products only and do not provide information on the dynamics of fragmentation. The aim of this contribution is thus to address the following fundamental questions. What are the physics that govern fragmentation processes? How fragmentation occurs through time? What are the mechanisms that produce power law fragment size distributions? And what are the scaling laws that control the exponent D? To address these questions, we performed a quantitative experimental study. The setup consists of a Hele-Shaw cell filled with a layer of cohesive silica flour, at the base of which a pulse of pressurized air is injected, leading to fragmentation of the layer of flour. The fragmentation process is monitored through time using a high-speed camera. By varying systematically the air pressure (P) and the thickness of the flour layer (h) we observed two morphologies of fragmentation: "lift off" where the silica flour above the injection inlet is ejected upwards, and "channeling" where the air pierces through the layer along sub-vertical conduit. By building a phase diagram, we show that the morphology is controlled by P/dgh, where d is the density of the flour and g is the gravitational acceleration. To quantify the fragmentation process, we developed a Matlab image analysis program, which calculates the number and sizes of the fragments, and so the fragment size distribution, during the experiments. The fragment size distributions are in general described by power law distributions of

  12. Fuel fragmentation data review and separate effects testing

    International Nuclear Information System (INIS)

    Yueh, Ken. H.; Snis, N.; Mitchell, D.; Munoz-Reja, C.

    2014-01-01

    A simple alternative test has been developed to study the fuel fragmentation process at loss of coolant accident (LOCA) temperatures. The new test heats a short section of fuel, approximately two pellets worth of material, in a tube furnace open to air. An axial slit is cut in the test sample cladding to reduce radial restraint and to simulate ballooned condition. The tube furnace allows the fuel fragmentation process be observed during the experiment. The test was developed as a simple alternative so large number of tests could be conducted quickly and efficiently to identify key variables that influence fuel fragmentation and to zeroing on the fuel fragmentation burn-up threshold. Several tests were conducted, using fuel materials from fuel rods that were used in earlier integral tests to benchmark and validate the test technique. High burn-up fuel materials known to be above the fragmentation threshold was used to evaluate the fragmentation process as a function of temperature. Even with an axial slit and both ends open, no significant fuel detachment/release was detected until above 750°C. Additional tests were conducted with fuel materials at burn-ups closer to the fuel fragmentation burn-up threshold. Results from these tests indicate a minor power history effect on the fuel fragmentation burn-up threshold. An evaluation of available literature and data generated from this work suggest a fuel fragmentation burn-up threshold between 70 and 75 GWd/MTU. (author)

  13. The multi-step prompt particle emission from fission fragments

    International Nuclear Information System (INIS)

    Zhivopistsev, A.; Oprea, C.; Oprea, I.

    2003-01-01

    The purpose of this work is the study of non-equilibrium high-energy gamma emission from 252 Cf. In the framework of the formalism of statistical multi-step compound processes in nuclear reactions. A relation was found between the shape of the high-energy part of the gamma spectrum and different mechanisms of excitation of the fission fragments. Agreement with experimental data for different groups of fission fragments was obtained. The analysis of the experimental high-energy part of gamma spectra yields information about the mechanism of excitation of fission fragments. The influence of dissipation of the deformation excess on intrinsic excitation of fission fragments was studied. (authors)

  14. Failure Rates in Introductory Programming

    DEFF Research Database (Denmark)

    Bennedsen, Jens; Caspersen, Michael Edelgaard

    2007-01-01

    It is a common conception that CS1 is a very difficult course and that failure rates are high. However, until now there has only been anecdotal evidence for this claim. This article reports on a survey among institutions around the world regarding failure rates in introductory programming courses...

  15. On the Quality of Failure

    Directory of Open Access Journals (Sweden)

    Bengt-Arne Vedin

    2014-05-01

    Full Text Available No innovation without failed experiments. No acquisition of competency without hard work, efforts to translate mistakes and insufficient – failed – attempts into mastery. The human condition is one defined by trial and error. Success equates with narrow escape from failure, whereas failure may be a success just missed. The purpose of management can be said to achieve success, so the management of failure is a key one, seeking to turn failure into profit. Almost no successful solutions remain eternally, so signals indicating that they have arrived in their twilight zone are important. Success may be too comforting and lulling, creating a dangerous success lock-in. Courting failure by acting against conventional wisdom and routine intuitions may, though risky, generate huge payoffs. A productive failure management should appreciate that failure is a way to uncertainty reduction, to better information and knowledge, new wisdom and new intuitions. Failure can and should be celebrated and harvested. The most successful mineral prospectors are those who drill more holes; while their percentage of dry ones is average, their number of lucky ones makes for success. The same holds for ideas, where there is the additional benefit that a larger number of ideas, diverse as they are, makes for improved idea handling proficiency.

  16. Biomarkers in acute heart failure.

    Science.gov (United States)

    Mallick, Aditi; Januzzi, James L

    2015-06-01

    The care of patients with acutely decompensated heart failure is being reshaped by the availability and understanding of several novel and emerging heart failure biomarkers. The gold standard biomarkers in heart failure are B-type natriuretic peptide and N-terminal pro-B-type natriuretic peptide, which play an important role in the diagnosis, prognosis, and management of acute decompensated heart failure. Novel biomarkers that are increasingly involved in the processes of myocardial injury, neurohormonal activation, and ventricular remodeling are showing promise in improving diagnosis and prognosis among patients with acute decompensated heart failure. These include midregional proatrial natriuretic peptide, soluble ST2, galectin-3, highly-sensitive troponin, and midregional proadrenomedullin. There has also been an emergence of biomarkers for evaluation of acute decompensated heart failure that assist in the differential diagnosis of dyspnea, such as procalcitonin (for identification of acute pneumonia), as well as markers that predict complications of acute decompensated heart failure, such as renal injury markers. In this article, we will review the pathophysiology and usefulness of established and emerging biomarkers for the clinical diagnosis, prognosis, and management of acute decompensated heart failure. Copyright © 2015 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.

  17. Bisoprolol for congestive heart failure

    DEFF Research Database (Denmark)

    Rosenberg, J.; Gustafsson, F.

    2008-01-01

    was obtained from the FDA website. Conclusion: Bisoprolol is an effective and well-tolerated first-line beta-blocker for patients with systolic heart failure. The knowledge is primarily based on study patients with moderate-to-severe heart failure from the three CIBIS trials Udgivelsesdato: 2008/2...

  18. Childhood heart failure in Ibadan

    African Journals Online (AJOL)

    Childhood heart failure in Ibadan. I. A. Lagunju and S. I. Omokhodion*. Department of Paediatrics. University College Hospital, Ibadan. Summary. One hundred consecutive admissions of children with a diagnosis of congestive cardiac failure to the paediatric department of the University College Hospital, Ibadan were.

  19. The effective fragment molecular orbital method for fragments connected by covalent bonds.

    Directory of Open Access Journals (Sweden)

    Casper Steinmann

    Full Text Available We extend the effective fragment molecular orbital method (EFMO into treating fragments connected by covalent bonds. The accuracy of EFMO is compared to FMO and conventional ab initio electronic structure methods for polypeptides including proteins. Errors in energy for RHF and MP2 are within 2 kcal/mol for neutral polypeptides and 6 kcal/mol for charged polypeptides similar to FMO but obtained two to five times faster. For proteins, the errors are also within a few kcal/mol of the FMO results. We developed both the RHF and MP2 gradient for EFMO. Compared to ab initio, the EFMO optimized structures had an RMSD of 0.40 and 0.44 Å for RHF and MP2, respectively.

  20. When fragments link: a bibliometric perspective on the development of fragment-based drug discovery.

    Science.gov (United States)

    Romasanta, Angelo K S; van der Sijde, Peter; Hellsten, Iina; Hubbard, Roderick E; Keseru, Gyorgy M; van Muijlwijk-Koezen, Jacqueline; de Esch, Iwan J P

    2018-05-05

    Fragment-based drug discovery (FBDD) is a highly interdisciplinary field, rich in ideas integrated from pharmaceutical sciences, chemistry, biology, and physics, among others. To enrich our understanding of the development of the field, we used bibliometric techniques to analyze 3642 publications in FBDD, complementing accounts by key practitioners. Mapping its core papers, we found the transfer of knowledge from academia to industry. Co-authorship analysis showed that university-industry collaboration has grown over time. Moreover, we show how ideas from other scientific disciplines have been integrated into the FBDD paradigm. Keyword analysis showed that the field is organized into four interconnected practices: library design, fragment screening, computational methods, and optimization. This study highlights the importance of interactions among various individuals and institutions from diverse disciplines in newly emerging scientific fields. Copyright © 2018. Published by Elsevier Ltd.

  1. Intelligent Design and Intelligent Failure

    Science.gov (United States)

    Jerman, Gregory

    2015-01-01

    Good Evening, my name is Greg Jerman and for nearly a quarter century I have been performing failure analysis on NASA's aerospace hardware. During that time I had the distinct privilege of keeping the Space Shuttle flying for two thirds of its history. I have analyzed a wide variety of failed hardware from simple electrical cables to cryogenic fuel tanks to high temperature turbine blades. During this time I have found that for all the time we spend intelligently designing things, we need to be equally intelligent about understanding why things fail. The NASA Flight Director for Apollo 13, Gene Kranz, is best known for the expression "Failure is not an option." However, NASA history is filled with failures both large and small, so it might be more accurate to say failure is inevitable. It is how we react and learn from our failures that makes the difference.

  2. Diabetes Mellitus and Heart Failure.

    Science.gov (United States)

    Lehrke, Michael; Marx, Nikolaus

    2017-06-01

    Epidemiologic and clinical data from the last 2 decades have shown that the prevalence of heart failure in diabetes is very high, and the prognosis for patients with heart failure is worse in those with diabetes than in those without diabetes. Experimental data suggest that various mechanisms contribute to the impairment in systolic and diastolic function in patients with diabetes, and there is an increased recognition that these patients develop heart failure independent of the presence of coronary artery disease or its associated risk factors. In addition, current clinical data demonstrated that treatment with the sodium glucose cotransporter 2 inhibitor empagliflozin reduced hospitalization for heart failure in patients with type 2 diabetes mellitus and high cardiovascular risk. This review article summarizes recent data on the prevalence, prognosis, pathophysiology, and therapeutic strategies to treat patients with diabetes and heart failure. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  3. Nuclear cardiology and heart failure

    International Nuclear Information System (INIS)

    Giubbini, Raffaele; Bertagna, Francesco; Milan, Elisa; Mut, Fernando; Dondi, Maurizio; Metra, Marco; Rodella, Carlo

    2009-01-01

    The prevalence of heart failure in the adult population is increasing. It varies between 1% and 2%, although it mainly affects elderly people (6-10% of people over the age of 65 years will develop heart failure). The syndrome of heart failure arises as a consequence of an abnormality in cardiac structure, function, rhythm, or conduction. Coronary artery disease is the leading cause of heart failure and it accounts for this disorder in 60-70% of all patients affected. Nuclear techniques provide unique information on left ventricular function and perfusion by gated-single photon emission tomography (SPECT). Myocardial viability can be assessed by both SPECT and PET imaging. Finally, autonomic dysfunction has been shown to increase the risk of death in patients with heart disease and this may be applicable to all patients with cardiac disease regardless of aetiology. MIBG scanning has a very promising prognostic value in patients with heart failure. (orig.)

  4. No significant fuel failures (NSFF)

    International Nuclear Information System (INIS)

    Domaratzki, Z.

    1979-01-01

    It has long been recognized that no emergency core cooling system (ECCS) could be absolutely guaranteed to prevent fuel failures. In 1976 the Atomic Energy Control Board decided that the objective for an ECCS should be to prevent fuel failures, but if the objective could not be met it should be shown that the consequences are acceptable for dual failures comprising any LOCA combined with an assumed impairment of containment. Out of the review of the Bruce A plant came the definition of 'no significant fuel failures': for any postulated LOCA combined with any one mode of containment impairment the resultant dose to a person at the edge of the exclusion zone is less than the reference dose limits for dual failures

  5. Bisoprolol for congestive heart failure

    DEFF Research Database (Denmark)

    Rosenberg, J.; Gustafsson, F.

    2008-01-01

    Background: beta-Blockers are a cornerstone in the treatment of systolic heart failure treatment, but not all beta-blockers are effective or in this setting. Objective: To define the role of bisoprolol, a highly selective beta(1)-antagonist in congestive heart failure due to systolic dysfunction....... Methods: Using the keywords 'bisoprolol' and 'heart failure' PubMed and BIOSIS databases were searched for information regarding pharmacology and relevant randomised clinical trials. Supplementary publications were acquired by scrutinising reference lists of relevant papers. Additional information...... was obtained from the FDA website. Conclusion: Bisoprolol is an effective and well-tolerated first-line beta-blocker for patients with systolic heart failure. The knowledge is primarily based on study patients with moderate-to-severe heart failure from the three CIBIS trials Udgivelsesdato: 2008/2...

  6. Failure Criteria for Reinforced Materials

    DEFF Research Database (Denmark)

    Rathkjen, Arne

    Failure of materials is often characterized as ductile yielding, brittle fracture, creep rupture, etc., and different criteria given in terms of different parameters have been used to describe different types of failure. Only criteria expressing failure in terms of stress are considered in what...... place until the matrix, the continuous component of the composite, fails. When an isotropic matrix is reinforced as described above, the result is an anisotropic composite material. Even if the material is anisotropic, it usually exhibits a rather high degree of symmetry and such symmetries place...... certain restrictions on the form of the failure criteria for anisotropic materials. In section 2, some failure criteria for homogenous materials are reviewed. Both isotropic and anisotropic materials are described, and in particular the constraints imposed on the criteria from the symmetries orthotropy...

  7. Nuclear cardiology and heart failure

    Energy Technology Data Exchange (ETDEWEB)

    Giubbini, Raffaele; Bertagna, Francesco [University of Brescia, Department of Nuclear Medicine, Brescia (Italy); Milan, Elisa [Ospedale Di Castelfranco Veneto, Nuclear Medicine Unit, Castelfranco Veneto (Italy); Mut, Fernando; Dondi, Maurizio [International Atomic Energy Agency, Nuclear Medicine Section, Division of Human Health, Vienna (Austria); Metra, Marco [University of Brescia, Department of Cardiology, Brescia (Italy); Rodella, Carlo [Health Physics Department, Spedali Civili di Brescia, Brescia (Italy)

    2009-12-15

    The prevalence of heart failure in the adult population is increasing. It varies between 1% and 2%, although it mainly affects elderly people (6-10% of people over the age of 65 years will develop heart failure). The syndrome of heart failure arises as a consequence of an abnormality in cardiac structure, function, rhythm, or conduction. Coronary artery disease is the leading cause of heart failure and it accounts for this disorder in 60-70% of all patients affected. Nuclear techniques provide unique information on left ventricular function and perfusion by gated-single photon emission tomography (SPECT). Myocardial viability can be assessed by both SPECT and PET imaging. Finally, autonomic dysfunction has been shown to increase the risk of death in patients with heart disease and this may be applicable to all patients with cardiac disease regardless of aetiology. MIBG scanning has a very promising prognostic value in patients with heart failure. (orig.)

  8. Failure detection system risk reduction assessment

    Science.gov (United States)

    Aguilar, Robert B. (Inventor); Huang, Zhaofeng (Inventor)

    2012-01-01

    A process includes determining a probability of a failure mode of a system being analyzed reaching a failure limit as a function of time to failure limit, determining a probability of a mitigation of the failure mode as a function of a time to failure limit, and quantifying a risk reduction based on the probability of the failure mode reaching the failure limit and the probability of the mitigation.

  9. Failure probabilistic model of CNC lathes

    International Nuclear Information System (INIS)

    Wang Yiqiang; Jia Yazhou; Yu Junyi; Zheng Yuhua; Yi Shangfeng

    1999-01-01

    A field failure analysis of computerized numerical control (CNC) lathes is described. Field failure data was collected over a period of two years on approximately 80 CNC lathes. A coding system to code failure data was devised and a failure analysis data bank of CNC lathes was established. The failure position and subsystem, failure mode and cause were analyzed to indicate the weak subsystem of a CNC lathe. Also, failure probabilistic model of CNC lathes was analyzed by fuzzy multicriteria comprehensive evaluation

  10. Plasminogen fragments K 1-3 and K 5 bind to different sites in fibrin fragment DD.

    Science.gov (United States)

    Grinenko, T V; Kapustianenko, L G; Yatsenko, T A; Yusova, O I; Rybachuk, V N

    2016-01-01

    Specific plasminogen-binding sites of fibrin molecule are located in Аα148-160 regions of C-terminal domains. Plasminogen interaction with these sites initiates the activation process of proenzyme and subsequent fibrin lysis. In this study we investigated the binding of plasminogen fragments K 1-3 and K 5 with fibrin fragment DD and their effect on Glu-plasminogen interaction with DD. It was shown that the level of Glu-plasminogen binding to fibrin fragment DD is decreased by 50-60% in the presence of K 1-3 and K 5. Fragments K 1-3 and K 5 have high affinity to fibrin fragment DD (Kd is 0.02 for K 1-3 and 0.054 μМ for K 5). K 5 interaction is independent and K 1-3 is partly dependent on C-terminal lysine residues. K 1-3 interacts with complex of fragment DD-immobilized K 5 as well as K 5 with complex of fragment DD-immobilized K 1-3. The plasminogen fragments do not displace each other from binding sites located in fibrin fragment DD, but can compete for the interaction. The results indicate that fibrin fragment DD contains different binding sites for plasminogen kringle fragments K 1-3 and K 5, which can be located close to each other. The role of amino acid residues of fibrin molecule Аα148-160 region in interaction with fragments K 1-3 and K 5 is discussed.

  11. RAY TRACING RENDER MENGGUNAKAN FRAGMENT ANTI ALIASING

    Directory of Open Access Journals (Sweden)

    Febriliyan Samopa

    2008-07-01

    Full Text Available Normal 0 false false false IN X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin-top:0cm; mso-para-margin-right:0cm; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0cm; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} Rendering is generating surface and three-dimensional effects on an object displayed on a monitor screen. Ray tracing as a rendering method that traces ray for each image pixel has a drawback, that is, aliasing (jaggies effect. There are some methods for executing anti aliasing. One of those methods is OGSS (Ordered Grid Super Sampling. OGSS is able to perform aliasing well. However, this method requires more computation time since sampling of all pixels in the image will be increased. Fragment Anti Aliasing (FAA is a new alternative method that can cope with the drawback. FAA will check the image when performing rendering to a scene. Jaggies effect is only happened at curve and gradient object. Therefore, only this part of object that will experience sampling magnification. After this sampling magnification and the pixel values are computed, then downsample is performed to retrieve the original pixel values. Experimental results show that the software can implement ray tracing well in order to form images, and it can implement FAA and OGSS technique to perform anti aliasing. In general, rendering using FAA is faster than using OGSS

  12. Release and characteristics of fungal fragments in various conditions

    Energy Technology Data Exchange (ETDEWEB)

    Mensah-Attipoe, Jacob [Department of Environmental Science, University of Eastern Finland, Yliopistonranta 1D, P. O. Box 1627, FI-70211 Kuopio (Finland); Saari, Sampo [Department of Physics, Tampere University of Technology, Korkeakoulunkatu 3, 33720 Tampere (Finland); Veijalainen, Anna-Maria; Pasanen, Pertti [Department of Environmental Science, University of Eastern Finland, Yliopistonranta 1D, P. O. Box 1627, FI-70211 Kuopio (Finland); Keskinen, Jorma [Department of Physics, Tampere University of Technology, Korkeakoulunkatu 3, 33720 Tampere (Finland); Leskinen, Jari T.T. [SIB Labs, University of Eastern Finland, Yliopistonranta 1E, P. O. Box 1627, FI-70211, Kuopio (Finland); Reponen, Tiina, E-mail: reponeta@ucmail.uc.edu [Department of Environmental Science, University of Eastern Finland, Yliopistonranta 1D, P. O. Box 1627, FI-70211 Kuopio (Finland); Department of Environmental Health, University of Cincinnati, P.O. Box 670056, Cincinnati, OH 45267-0056 (United States)

    2016-03-15

    Intact spores and submicrometer size fragments are released from moldy building materials during growth and sporulation. It is unclear whether all fragments originate from fungal growth or if small pieces of building materials are also aerosolized as a result of microbial decomposition. In addition, particles may be formed through nucleation from secondary metabolites of fungi, such as microbial volatile organic compounds (MVOCs). In this study, we used the elemental composition of particles to characterize the origin of submicrometer fragments released from materials contaminated by fungi. Particles from three fungal species (Aspergillus versicolor, Cladosporium cladosporioides and Penicillium brevicompactum), grown on agar, wood and gypsum board were aerosolized using the Fungal Spore Source Strength Tester (FSSST) at three air velocities (5, 16 and 27 m/s). Released spores (optical size, d{sub p} ≥ 0.8 μm) and fragments (d{sub p} ≤ 0.8 μm) were counted using direct-reading optical aerosol instruments. Particles were also collected on filters, and their morphology and elemental composition analyzed using scanning electron microscopes (SEMs) coupled with an Energy-Dispersive X-ray spectroscopy (EDX). Among the studied factors, air velocity resulted in the most consistent trends in the release of fungal particles. Total concentrations of both fragments and spores increased with an increase in air velocity for all species whereas fragment–spore (F/S) ratios decreased. EDX analysis showed common elements, such as C, O, Mg and Ca, for blank material samples and fungal growth. However, N and P were exclusive to the fungal growth, and therefore were used to differentiate biological fragments from non-biological ones. Our results indicated that majority of fragments contained N and P. Because we observed increased release of fragments with increased air velocities, nucleation of MVOCs was likely not a relevant process in the formation of fungal fragments. Based

  13. Lessons learned from failure analysis

    International Nuclear Information System (INIS)

    Le May, I.

    2006-01-01

    Failure analysis can be a very useful tool to designers and operators of plant and equipment. It is not simply something that is done for lawyers and insurance companies, but is a tool from which lessons can be learned and by means of which the 'breed' can be improved. In this presentation, several failure investigations that have contributed to understanding will be presented. Specifically, the following cases will be discussed: 1) A fire at a refinery that occurred in a desulphurization unit. 2) The failure of a pipeline before it was even put into operation. 3) Failures in locomotive axles that took place during winter operation. The refinery fire was initially blamed on defective Type 321 seamless stainless steel tubing, but there were conflicting views between 'experts' involved as to the mechanism of failure and the writer was called upon to make an in-depth study. This showed that there were a variety of failure mechanism involved, including high temperature fracture, environmentally-induced cracking and possible manufacturing defects. The unraveling of the failure sequence is described and illustrated. The failure of an oil transmission was discovered when the line was pressure tested some months after it had been installed and before it was put into service. Repairs were made and failure occurred in another place upon the next pressure test being conducted. After several more repairs had been made the line was abandoned and a lawsuit was commenced on the basis that the steel was defective. An investigation disclosed that the material was sensitive to embrittlement and the causes of this were determined. As a result, changes were made in the microstructural control of the product to avoid similar problems in future. A series of axle failures occurred in diesel electric locomotives during winter. An investigation was made to determine the nature of the failures which were not by classical fatigue, nor did they correspond to published illustrations of Cu

  14. Environmental toxicants cause sperm DNA fragmentation as detected by the Sperm Chromatin Structure Assay (SCSA[reg])

    International Nuclear Information System (INIS)

    Evenson, Donald P.; Wixon, Regina

    2005-01-01

    Studies over the past two decades have clearly shown that reproductive toxicants cause sperm DNA fragmentation. This DNA fragmentation can usually be detected prior to observing alterations of metaphase chromosomes in embryos. Thus, Sperm Chromatin Structure Assay (SCSA)-detected DNA damage is viewed as the molecular precursor to later gross chromosome damage observed under the light microscope. SCSA measurements of animal or human sperm consist of first obtaining a fresh or flash frozen neat semen sample in LN2 or dry ice. Samples are then sent to a SCSA diagnostic laboratory where the samples are thawed, diluted to ∼1-2 x 106 sperm/ml, treated for 30 s with a pH 1.2 detergent buffer and then stained with acridine orange (AO). The low pH partially denatures DNA at the sites of DNA strand breaks and the AO-ssDNA fluoresces red while the AO-dsDNA fluoresces green. Flow cytometry measurements of 5000 sperm/sample provide statistically robust data on the ratio of red to green sperm, the extent of the DNA fragmentation and the standard deviations of measures. Numerous experiments on rodents treated with reproductive toxicants clearly showed that SCSA measures are highly dose responsive and have a very low CV. Different agents that act on germ cells at various stages of development usually showed sperm DNA fragmentation when that germ cell fraction arrived in the epididymis or ejaculate. Some of these treated samples were capable of successful in vitro fertilization but with frequent embryo failure. A 2-year longitudinal study of men living a valley town with a reported abnormal level of infertility and spontaneous miscarriages and also a seasonal atmospheric smog pollution, showed, for the first time, that SCSA measurements of human sperm DNA fragmentation were detectable and correlated with dosage of air pollution while the classical semen measures were not correlated. Also, young men spraying pesticides without protective gear are at an increased risk for elevated

  15. The Nagoya Protocol: Fragmentation or Consolidation?

    Directory of Open Access Journals (Sweden)

    Carmen Richerzhagen

    2014-02-01

    Full Text Available In October, 2010, a protocol on access and benefit-sharing (ABS of genetic resources was adopted, the so-called Nagoya Protocol on Access to Genetic Resources and the Fair and Equitable Sharing of Benefits Arising from their Utilization to the Convention on Biological Diversity. Before the adoption of the Nagoya Protocol, the governance architecture of ABS was already characterized by a multifaceted institutional environment. The use of genetic resources is confronted with many issues (conservation, research and development, intellectual property rights, food security, health issues, climate change that are governed by different institutions and agreements. The Nagoya Protocol contributes to increased fragmentation. However, the question arises whether this new regulatory framework can help to advance the implementation of the ABS provisions of the Convention on Biological Diversity (CBD. This paper attempts to find an answer to that question by following three analytical steps. First, it analyzes the causes of change against the background of theories of institutional change. Second, it aims to assess the typology of the architecture in order to find out if this new set of rules will contribute to a more synergistic, cooperative or conflictive architecture of ABS governance. Third, the paper looks at the problem of “fit” and identifies criteria that can be used to assess the new ABS governance architecture with regard to its effectiveness.

  16. Fragmentation modeling of a resin bonded sand

    Science.gov (United States)

    Hilth, William; Ryckelynck, David

    2017-06-01

    Cemented sands exhibit a complex mechanical behavior that can lead to sophisticated models, with numerous parameters without real physical meaning. However, using a rather simple generalized critical state bonded soil model has proven to be a relevant compromise between an easy calibration and good results. The constitutive model formulation considers a non-associated elasto-plastic formulation within the critical state framework. The calibration procedure, using standard laboratory tests, is complemented by the study of an uniaxial compression test observed by tomography. Using finite elements simulations, this test is simulated considering a non-homogeneous 3D media. The tomography of compression sample gives access to 3D displacement fields by using image correlation techniques. Unfortunately these fields have missing experimental data because of the low resolution of correlations for low displacement magnitudes. We propose a recovery method that reconstructs 3D full displacement fields and 2D boundary displacement fields. These fields are mandatory for the calibration of the constitutive parameters by using 3D finite element simulations. The proposed recovery technique is based on a singular value decomposition of available experimental data. This calibration protocol enables an accurate prediction of the fragmentation of the specimen.

  17. Fragmentation functions of polarized heavy quarkonium

    International Nuclear Information System (INIS)

    Ma, Yan-Qing; Qiu, Jian-Wei; Zhang, Hong

    2015-01-01

    Investigating the production of polarized heavy quarkonia in terms of recently proposed QCD factorization formalism requires the knowledge of a large number of input fragmentation functions (FFs) from a single parton or a heavy quark-antiquark pair to a polarized heavy quarkonium. We study these universal FFs at the input factorization scale μ 0 ≳2m Q , with heavy quark mass m Q , in the framework of nonrelativistic QCD (NRQCD) factorization. We express these FFs in terms of perturbatively calculable coefficients for producing a heavy quark-antiquark pair in all possible NRQCD states, multiplied by corresponding NRQCD long-distance matrix elements for the pair to transmute into a polarized heavy quarkonium. We derive all relevant NRQCD operators for the long-distance matrix elements based on symmetries, and introduce a self-consistent scheme to define them in arbitrary d-dimensions. We compute, up to the first non-trivial order in α s , the perturbative coefficients for producing a heavy quark pair in all possible S-wave and P-wave NRQCD states. We also discuss the role of the polarized FFs in generating QCD predictions for the polarization of J/ψ produced at collider energies.

  18. In situ observation of ultrasonic cavitation-induced fragmentation of the primary crystals formed in Al alloys.

    Science.gov (United States)

    Wang, Feng; Tzanakis, Iakovos; Eskin, Dmitry; Mi, Jiawei; Connolley, Thomas

    2017-11-01

    The cavitation-induced fragmentation of primary crystals formed in Al alloys were investigated for the first time by high-speed imaging using a novel experimental approach. Three representative primary crystal types, Al 3 Ti, Si and Al 3 V with different morphologies and mechanical properties were first extracted by deep etching of the corresponding Al alloys and then subjected to ultrasonic cavitation processing in distilled water. The dynamic interaction between the cavitation bubbles and primary crystals was imaged in situ and in real time. Based on the recorded image sequences, the fragmentation mechanisms of primary crystals were studied. It was found that there are three major mechanisms by which the primary crystals were fragmented by cavitation bubbles. The first one was a slow process via fatigue-type failure. A cyclic pressure exerted by stationary pulsating bubbles caused the propagation of a crack pre-existing in the primary crystal to a critical length which led to fragmentation. The second mechanism was a sudden process due to the collapse of bubbles in a passing cavitation cloud. The pressure produced upon the collapse of the cloud promoted rapid monotonic crack growth and fast fracture in the primary crystals. The third observed mechanism was normal bending fracture as a result of the high pressure arising from the collapse of a bubble cloud and the crack formation at the branch connection points of dendritic primary crystals. The fragmentation of dendrite branches due to the interaction between two freely moving dendritic primary crystals was also observed. A simplified fracture analysis of the observed phenomena was performed. The specific fragmentation mechanism for the primary crystals depended on their morphology and mechanical properties. Copyright © 2017 The Author(s). Published by Elsevier B.V. All rights reserved.

  19. Fracture and embolization of a Björk-Shiley disc. Fatal failure of a prosthetic mitral valve.

    Science.gov (United States)

    Norenberg, D D; Evans, R W; Gundersen, A E; Abellera, R M

    1977-12-01

    A case of fracture of the disc occluder of a Bjork-Shiley mitral prosthesis with embolization of the disc fragments to distal aorta is presented. The possibility of valve dysfunction and the diagnostic value of echocardiography should be considered whenever acute heart failure occurs in a patient with an artificial valve.

  20. Application of tomographics methods for determination of rock failure in situ

    Directory of Open Access Journals (Sweden)

    Pandula Blažej

    1996-03-01

    Full Text Available Rock Failure determination closely connects with optimalization of rock disintegration as well excavation of underground openings. The aim of this optimalization is than to reach desired fragmentation during the blasting as well as choose the most suitable excavation technology. Study of rock failure can be very useful to reach this goal. In practice it can be done on the basis of personal technological experiences of blasting operator obtained in long term experiences in situ conditions. Because in many cases that experiences can not be utilised, it is necessary to learn against more precise rock failure evaluation. It can also down the costs of disintegration as well as excavation. The paper deals with results of common geophysical methods and methods of seismic tomography achieved at the hidden rock failure determination in the rock masses of the Ruzin dam during projecting the outlet equipment.