WorldWideScience

Sample records for benign stab detonators

  1. Environmentally Benign Stab Detonators

    Energy Technology Data Exchange (ETDEWEB)

    Gash, A E

    2006-07-07

    The coupling of energetic metallic multilayers (a.k.a. flash metal) with energetic sol-gel synthesis and processing is an entirely new approach to forming energetic devices for several DoD and DOE needs. They are also practical and commercially viable manufacturing techniques. Improved occupational safety and health, performance, reliability, reproducibility, and environmentally acceptable processing can be achieved using these methodologies and materials. The development and fielding of this technology will enhance mission readiness and reduce the costs, environmental risks and the necessity of resolving environmental concerns related to maintaining military readiness while simultaneously enhancing safety and health. Without sacrificing current performance, we will formulate new impact initiated device (IID) compositions to replace materials from the current composition that pose significant environmental, health, and safety problems associated with functions such as synthesis, material receipt, storage, handling, processing into the composition, reaction products from testing, and safe disposal. To do this, we will advance the use of nanocomposite preparation via the use of multilayer flash metal and sol-gel technologies and apply it to new small IIDs. This work will also serve to demonstrate that these technologies and resultant materials are relevant and practical to a variety of energetic needs of DoD and DOE. The goal will be to produce an IID whose composition is acceptable by OSHA, EPA, the Clean Air Act, Clean Water Act, Resource Recovery Act, etc. standards, without sacrificing current performance. The development of environmentally benign stab detonators and igniters will result in the removal of hazardous and toxic components associated with their manufacturing, handling, and use. This will lead to improved worker safety during manufacturing as well as reduced exposure of Service personnel during their storage and or use in operations. The

  2. Stab resistant body armour

    OpenAIRE

    Horsfall, I

    2000-01-01

    There is now a widely accepted need for stab resistant body armour for the police in the UK. However, very little research has been done on knife resistant systems and the penetration mechanics of sharp projectiles are poorly understood. This thesis explores the general background to knife attack and defence with a particular emphasis on the penetration mechanics of edged weapons. The energy and velocity that can be achieved in stabbing actions has been determined for a numb...

  3. Primary stabbing headache.

    Science.gov (United States)

    Pareja, Juan A; Sjaastad, Ottar

    2010-01-01

    Primary stabbing headache is characterized by transient, cephalic ultrashort stabs of pain. It is a frequent complaint with a prevalence of 35.2%, a female preponderance, and a mean age of onset of 28 years (Vågå study). Attacks are generally characterized by moderate to severe, jabbing or stabbing pain, lasting from a fraction of a second to 3s. Attack frequency is generally low, with one or a few attacks per day. The paroxysms generally occur spontaneously, during daytime. Most patients exhibit a sporadic pattern, with an erratic, unpredictable alternation between symptomatic and non-symptomatic periods. Paroxysms are almost invariably unilateral. Temporal and fronto-ocular areas are most frequently affected. Attacks tend to move from one area to another, in either the same or the opposite hemicranium. Jabs may be accompanied by a shock-like feeling and even by head movement - "jolts" -or vocalization. On rare occasions, conjunctival hemorrhage and monocular vision loss have been described as associated features. Primary stabbing headache may concur, synchronously or independently, with other primary headaches. In contrast to what is the case in adults, in childhood it is not usually associated with other headaches. Treatment is rarely necessary. Indomethacin, 75-150 mg daily, may seem to be of some avail. Celecoxib, nifedipine, melatonin, and gabapentin have been reported to be effective in isolated cases and small series of patients. The drug studies need corroboration. Copyright © 2011 Elsevier B.V. All rights reserved.

  4. Thermonuclear detonation

    International Nuclear Information System (INIS)

    Feoktistov, L.P.

    1998-01-01

    The characteristics of, and energy transfer mechanisms involved in, thermonuclear detonation are discussed. What makes the fundamental difference between thermonuclear and chemical detonation is that the former has a high specific energy release and can therefore be employed for preliminary compressing the thermonuclear mixture ahead of the burning wave. Consequently, with moderate (mega joule) initiation energies, a steady-state detonation laboratory experiment with unlimited energy multiplication becomes a possibility

  5. Thermonuclear detonation

    International Nuclear Information System (INIS)

    Feoktistov, L P

    1998-01-01

    The characteristics of, and energy transfer mechanisms involved in, thermonuclear detonation are discussed. What makes the fundamental difference between thermonuclear and chemical detonation is that the former has a high specific energy release and can therefore be employed for preliminarily compressing the thermonuclear mixture ahead of the burning wave. Consequently, with moderate (megajoule) initiation energies, a steady-state detonation laboratory experiment with unlimited energy multiplication becomes a possibility. (from the history of physics)

  6. Standing detonation wave engine

    KAUST Repository

    Kasimov, Aslan

    2015-01-01

    A detonation engine can detonate a mixture of fuel and oxidizer within a cylindrical detonation region to produce work. The detonation engine can have a first and a second inlet having ends fluidly connected from tanks to the detonation engine

  7. Multiple stabbing in sex-related homicides.

    Science.gov (United States)

    Radojević, Nemanja; Radnić, Bojana; Petković, Stojan; Miljen, Maletin; Curović, Ivana; Cukić, Dragana; Soć, Miodrag; Savić, Slobodan

    2013-07-01

    It is possible that sexually driven homicides are the consequence of sexual deviation, but more often than not the main cause of such homicides stems from a non-paraphilic person's emotional component. It is known that homicides which involve multiple stabbing are very often the result of the assailant's highly expressed affect. This study tries to establish whether such homicides are essentially related to the sexual motives of the murderer. This paper is conducted through a retrospective autopsy study that includes 766 cases of homicides. These were reviewed and analysed according to the motive of the homicide, as well as by method, age, and gender of the victim, and the relationship between the victim and the assailant. The motives of homicides are classified as non-sexual and sexual, including homicides related to rape, jealousy, amorous affairs outside of an established relationship, deviant sexual behaviour of psychiatric patients, paraphilia, and disturbed emotional relationships between the victim and the assailant. Cases include both hetero- and homosexual relationships. Multiple stabbing occurs significantly more frequently in sex-related homicides (≥ 3 stab wounds) than in other homicide types. When the criteria for multiple stabbing are changed (≥ 4, 5, or 25 stab wounds), the percentage of sex-related homicides rises in every group in relation to the increased number of wounds. Sensitivity and specificity are represented by ROC curves for 3, 5 and 7 stab wounds. The correlation coefficients between multiple stabbing and sex-related homicides regarding gender are all near 0.9. For female victims, all homicides committed by 25 and more stab wounds were found to be sex-related. Statistically, jealousy was the most frequent motive for sex-related multiple stabbing homicides. Regardless of age, homicides involving multiple stabbings should be considered sex-related, especially when the victim is female. Copyright © 2013 Elsevier Ltd and Faculty of

  8. Textile sensors for stab and cut detection

    Science.gov (United States)

    Graßmann, C.; Obermann, M.; Lempa, E.; Bache, T.; Siegel, P. K.; Freyer, T.; Paschko, S.; Beyer, T.; Kirsche, M.; Schwarz-Pfeiffer, A.

    2017-10-01

    Manufacturers are aiming for more flexible and lightweight protective clothing to increase wearing comfort. A cardigan with a knitted stab-resistant inlay and an alarm system is presented. The stab-resistant inlay is based on a multilayer ultra-high molecular weight poly ethylene (UHMW-PE) fabric. Stab resistance was evaluated according to the standard of the Association of Test Laboratories for Bullet, Stab or Pike Resistant Materials and Construction Standard (VPAM 2011). Furthermore sensors for the detection of cuts and pressure were integrated. Both sensors can trigger alarms if the wearer is attacked. Normal pressure occurring through leaning on a wall or sitting is filtered out and does not trigger an alarm.

  9. The imaging of stab injuries

    Energy Technology Data Exchange (ETDEWEB)

    Vries, Coert S. de; Africa, Mogoeemang; Gebremariam, Fekade A.; Rensburg, J. Janse van; Otto, Susan F.; Potgieter, Henrik F. (Dept. of Diagnostic Radiology, Faculty of Health Sciences, Univ. of the Free State and Academic Health Complex, Free State Province Dept. of Health, Bloemfontein (South Africa)), e-mail: devriesc.md@ufs.ac.za

    2010-01-15

    In the trauma unit of the Bloemfontein Academic Complex, the total number of stab wounds seen represents approximately 70.5% of penetrating injuries, which is 6.4% of 5004 trauma cases seen in a period of 1 year. The other cases are gunshot wounds and pedestrian or motor vehicle accidents. Specific guidelines and protocols are followed for penetrating trauma management. All imaging modalities are utilized, with chest radiography the mainstay of thoracic imaging in patients having sustained sharp penetrating chest injuries. Computed tomography (CT) is being used more frequently as the primary imaging modality in the evaluation of hemodynamically stable patients with penetrating injuries. The improved speed of data acquisition and superior image reconstruction of multidetector CT (MDCT) has further driven this change in imaging approach. Although digital subtraction angiography (DSA) has been the reference standard for the diagnosis of traumatic vascular injuries, it is giving way to faster, less invasive, and less personnel-intensive imaging techniques, e.g., MDCT angiography. Given the fact that we work in an academic environment and that we have a dedicated interventional unit, arteriography is still frequently performed and still has its place as the 'gold standard' in the diagnosis of vascular injuries. Penetrating chest injuries suspected of traversing the mediastinum or extending near the posterior mediastinal structures dictate esophageal and tracheal evaluation. Although radiology has a role to play, direct visualization (esophagoscopy, bronchoscopy) remains the most reliable method of excluding injuries to these structures. Transthoracic ultrasound (echocardiography) has become indispensable in helping to evaluate injuries to the heart and the ascending and descending aortas. More recent work has demonstrated that ultrasonography can also be used to detect hemothoraces and pneumothoraces with accuracy

  10. Penetrating Stab Wound of the Right Ventricle

    Directory of Open Access Journals (Sweden)

    Onursal Buğra

    2010-04-01

    Full Text Available 18 years old male patient was admitted to our emergency unit with a penetrating stab wound to the right ventricle. A stab wound to the right ventricle was found to be 3 cm in diameter. The bleeding was controlled by insertion of a Foley catheter and inflation of the balloon. The stab wound had transected distal acute marginal side ofthe right coronary artery. A successful repair was performed with the use of a foley catheter and application of the Medtronic Octopus Tissue Stabilization System. The wound was closed with pledgeted mattress sutures. The distal acute marginal side of the right coronary artery was ligated. In this presentation, the surgical intervention method was reported and followed by a discussion of emergency surgical procedures of the heart.

  11. Occult diaphragmatic injuries caused by stab wounds.

    Science.gov (United States)

    Leppäniemi, Ari; Haapiainen, Reijo

    2003-10-01

    Missed diaphragmatic perforation caused by penetrating trauma can lead to subsequent strangulation of a hollow viscus, which has prompted the use of invasive diagnostic procedures to exclude occult diaphragmatic injuries in asymptomatic, high-risk patients. The objective of this study was to determine the incidence of occult diaphragmatic injuries caused by stab wounds of the lower chest and upper abdomen, and to examine the natural history and consequences of missed diaphragmatic injuries. On the basis of patient data from two previous randomized studies from our institution, a retrospective analysis was performed on 97 patients treated for anterior stab wounds located between the nipple line, the umbilical level, and the posterior axillary lines not having indications for immediate surgical exploration. The patients were divided into two groups on the basis of their initial randomized management (open or laparoscopic exploration vs. expectant observation). In the exploration group (n = 47), four diaphragmatic injuries (9%) were detected (three left-sided and one right-sided). Excluding patients with associated injuries requiring surgical repair, the incidence of occult diaphragmatic injuries was 3 of 43 (7%). In the observation group (n = 50), there were two patients (4%) with delayed presentation of missed left-sided diaphragmatic injury 2 and 23 months later, respectively. Both injuries resulted from stab wounds of the left flank and presented with herniation of the stomach or small bowel and colon. The overall incidence of occult diaphragmatic injuries in left-sided thoracoabdominal stab wounds was 4 of 24 (17%), and was much lower after stab wounds of left epigastrium (0%), right lower chest (0%), and right epigastrium (4%). In asymptomatic patients with anterior or flank stab wounds of the lower chest or upper abdominal area, the risk of an occult diaphragmatic injury is approximately 7% which, if undetected, is associated with a high risk of subsequent

  12. 17th STAB/DGLR Symposium

    CERN Document Server

    Heller, Gerd; Kreplin, Hans-Peter; Nitsche, Wolfgang; Peltzer, Inken

    2013-01-01

    This volume contains the contributions to the 17th Symposium of STAB (German Aerospace Aerodynamics Association). STAB includes German scientists and engineers from universities, research establishments and industry doing research and project work in numerical and experimental fluid mechanics and aerodynamics, mainly for aerospace but also for other applications. Many of the contributions collected in this book present results from national and European Community sponsored projects. This volume gives a broad overview of the ongoing work in this field in Germany and spans a wide range of topics: airplane aerodynamics, multidisciplinary optimization and new configurations, hypersonic flows and aerothermodynamics, flow control (drag reduction and laminar flow control), rotorcraft aerodynamics, aeroelasticity and structural dynamics, numerical simulation, experimental simulation and test techniques, aeroacoustics as well as the new fields of biomedical flows, convective flows, aerodynamics and acoustics of high-s...

  13. 18th STAB/DGLR Symposium

    CERN Document Server

    Heller, Gerd; Krämer, Ewald; Kreplin, Hans-Peter; Nitsche, Wolfgang; Rist, Ulrich

    2014-01-01

    This book presents contributions to the 18th biannual symposium of the German Aerospace Aerodynamics Association (STAB). The individual chapters reflect ongoing research conducted by the STAB members in the field of numerical and experimental fluid mechanics and aerodynamics, mainly for (but not limited to) aerospace applications, and cover both nationally and EC-funded projects. By addressing a number of essential research subjects, together with their related physical and mathematics fundamentals, the book provides readers with a comprehensive overview of the current research work in the field, as well as its main challenges and new directions. Current work on e.g. high aspect-ratio and low aspect-ratio wings, bluff bodies, laminar flow control and transition, active flow control, hypersonic flows, aeroelasticity, aeroacoustics and biofluid mechanics is exhaustively discussed here.  .

  14. Standing detonation wave engine

    KAUST Repository

    Kasimov, Aslan

    2015-10-08

    A detonation engine can detonate a mixture of fuel and oxidizer within a cylindrical detonation region to produce work. The detonation engine can have a first and a second inlet having ends fluidly connected from tanks to the detonation engine. The first and second inlets can be aligned along a common axis. The inlets can be connected to nozzles and a separator can be positioned between the nozzles and along the common axis.

  15. Herpes simplex virus following stab phlebectomy.

    Science.gov (United States)

    Hicks, Caitlin W; Lum, Ying Wei; Heller, Jennifer A

    2017-03-01

    Herpes simplex virus infection following surgery is an unusual postoperative phenomenon. Many mechanisms have been suggested, with the most likely explanation related to latent virus reactivation due to a proinflammatory response in the setting of local trauma. Here, we present a case of herpes simplex virus reactivation in an immunocompetent female following a conventional right lower extremity stab phlebectomy. Salient clinical and physical examination findings are described, and management strategies for herpes simplex virus reactivation are outlined. This is the first known case report of herpes simplex virus reactivation following lower extremity phlebectomy.

  16. 11th AG STAB/DGLR Symposium

    CERN Document Server

    Heinemann, Hans-Joachim; Hilbig, Reinhard

    1999-01-01

    This volume contains the papers of the 11th Symposium of the AG STAB (German Aerospace Aerodynamics Association). In this association those scientists and engineers from universities, research-establishments and industry are involved, who are doing research and project work in numerical and experimental fluid mechanics and aerodynamics for aerospace and other applications. Many of the contributions are giving results from the "Luftfahrtforschungsprogramm der Bundesregierung (German Aeronautical Research Programme). Some of the papers report on work sponsored by the Deutsche Forschungsgemeinschaft, DFG, which also was presented at the symposium. The volume gives a broad overview over the ongoing work in this field in Germany.

  17. A Comparison of Self-Inflicted Stab Wounds Versus Assault-Induced Stab Wounds

    Science.gov (United States)

    Ahn, Sanghyun; Kim, Dong Jin; Paik, Kwang Yeol; Chung, Jae Hee; Park, Woo-Chan; Kim, Wook; Lee, In Kyu

    2016-01-01

    Background Although self-inflicted and assault-induced knife injuries might have different mortality and morbidity rates, no studies have actually evaluated the importance of the cause of knife injuries in terms of patient outcomes and treatment strategies. Objectives The aims of this study were to assess the difference between the outcomes of patients presenting with self-inflicted stab wounds (SISW) versus assault-induced stab wounds (AISW). Patients and Methods A retrospective review of the relevant electronic medical records was performed for the period between January 2000 and December 2012 for patients who were referred to the department of surgery for stab wounds by the trauma team. The patients were divided into either SISW (n = 10) or AISW groups (n = 11), depending on the cause of the injury. Results A total of 19 patients had undergone exploratory laparotomy. Of the nine patients with SISW undergoing this procedure, no injury was found in seven of the patients. In the AISW group, eight of the ten laparotomies were therapeutic. Three patients in the AISW group died during hospital admission. The average number of stab wounds was 1.2 for the SISW group and 3.5 for the AISW group. Organ injuries were more frequent in the AISW group, affecting the lung (2), diaphragm (3), liver (5), small bowel (2), colon (2), and kidney (1). Conclusions Although evaluations of the initial vital signs and physical examinations are still important, the history regarding the source of the stab wounds (AISW vs. SISW) may be helpful in determining the appropriate treatment methods and predicting patient outcomes. PMID:28184363

  18. Unusual Presentation of Meningitis following Stab Neck | Motsitsi ...

    African Journals Online (AJOL)

    Background: A case report of stab neck presenting at Kalafong Hospital, Pretoria, South Africa with atypical meningitis. The objective was to illustrate the challenge of diagnosing this unusual and late presentation of meningitis. Case Report: A 48 year-old male patient presented to us two days after a stab neck. He was ...

  19. Detonation Wave Profile

    Energy Technology Data Exchange (ETDEWEB)

    Menikoff, Ralph [Los Alamos National Laboratory

    2015-12-14

    The Zel’dovich-von Neumann-Doering (ZND) profile of a detonation wave is derived. Two basic assumptions are required: i. An equation of state (EOS) for a partly burned explosive; P(V, e, λ). ii. A burn rate for the reaction progress variable; d/dt λ = R(V, e, λ). For a steady planar detonation wave the reactive flow PDEs can be reduced to ODEs. The detonation wave profile can be determined from an ODE plus algebraic equations for points on the partly burned detonation loci with a specified wave speed. Furthermore, for the CJ detonation speed the end of the reaction zone is sonic. A solution to the reactive flow equations can be constructed with a rarefaction wave following the detonation wave profile. This corresponds to an underdriven detonation wave, and the rarefaction is know as a Taylor wave.

  20. Confined Detonations and Pulse Detonation Engines

    Science.gov (United States)

    2003-01-01

    detonation. Actes du Colloque International Berthelot-Vieille- Mallard- Le Chatelier Proceedings. Bordeaux, France 2:437-42. 13. Edwards, D., G. Hooper, and R...A.A. Vasil’ev 1 Introduction ... ... .... ... .... . .. .. .. .. 41 2 Principles of DDT Acceleration ............... 42 3 Construction of DDT...Universit6 de Poitiers 1, Avenue Clement Ader E. DANIAU BP 40109, 86961 Futuroscope Cedex, France MBDA-F 8, rue Le Brix, BP 35 S.M. FROLOV 18020

  1. Scientific Letter: Stabbing nails into the neck: an unusual self ...

    African Journals Online (AJOL)

    Scientific Letter: Stabbing nails into the neck: an unusual self-damaging behavior mandating neurosurgery. A Aghabiklooei, R Aghabiklooei, N Zamani. Abstract. Scientific Letter - No Abstract Available. Full Text: EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT.

  2. An optimal dynamic interval stabbing-max data structure?

    DEFF Research Database (Denmark)

    Agarwal, Pankaj Kumar; Arge, Lars; Yi, Ke

    2005-01-01

    In this paper we consider the dynamic stabbing-max problem, that is, the problem of dynamically maintaining a set S of n axis-parallel hyper-rectangles in Rd, where each rectangle s ∈ S has a weight w(s) ∈ R, so that the rectangle with the maximum weight containing a query point can be determined...

  3. Abdominal and lower back pain in pediatric idiopathic stabbing headache.

    Science.gov (United States)

    Kakisaka, Yosuke; Ohara, Tomoichiro; Hino-Fukuyo, Naomi; Uematsu, Mitsugu; Kure, Shigeo

    2014-01-01

    Idiopathic stabbing headache (ISH) is a primary headache syndrome characterized by transient, sharp, stabbing pains located in the first division of the trigeminal nerve. Reports of pediatric ISH are rare, and extracephalic pain in pediatric ISH is extremely rare. Here we report the case of a 7-year-old male patient suffering from frequent, short, stabbing headache, which was occasionally associated with abdominal and lower back pain. Various investigations were normal. He was diagnosed with ISH, and valproic acid was administered to relieve his headache and accompanying symptoms. Our case demonstrates that abdominal and lower back pain may occur in pediatric ISH. This case may provide new evidence linking ISH and migraine by showing that extracephalic symptoms accompanying ISH are similar to those of migraine. We hypothesize that the mechanism underlying the headache and abdominal and lower back pain associated with ISH may be similar to that of a migraine headache. Accumulating additional cases by asking specific questions regarding the presence of the unusual symptoms presented in our case may help to establish a detailed clinical profile of these unfamiliar and peculiar symptoms in the pediatric ISH population.

  4. A detonation model of high/low velocity detonation

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Shaoming; Li, Chenfang; Ma, Yunhua; Cui, Junmin [Xian Modern Chemistry Research Institute, Xian, 710065 (China)

    2007-02-15

    A new detonation model that can simulate both high and low velocity detonations is established using the least action principle. The least action principle is valid for mechanics and thermodynamics associated with a detonation process. Therefore, the least action principle is valid in detonation science. In this model, thermodynamic equilibrium state is taken as the known final point of the detonation process. Thermodynamic potentials are analogous to mechanical ones, and the Lagrangian function in the detonation process is L=T-V. Under certain assumptions, the variation calculus of the Lagrangian function gives two solutions: the first one is a constant temperature solution, and the second one is the solution of an ordinary differential equation. A special solution of the ordinary differential equation is given. (Abstract Copyright [2007], Wiley Periodicals, Inc.)

  5. Detonation Jet Engine. Part 2--Construction Features

    Science.gov (United States)

    Bulat, Pavel V.; Volkov, Konstantin N.

    2016-01-01

    We present the most relevant works on jet engine design that utilize thermodynamic cycle of detonative combustion. Detonation engines of various concepts, pulse detonation, rotational and engine with stationary detonation wave, are reviewed. Main trends in detonation engine development are discussed. The most important works that carried out…

  6. Flow Visualization of a Rotating Detonation Engine

    Science.gov (United States)

    2016-10-05

    SUPPLEMENTARY NOTES 14. ABSTRACT The rotating detonation engine ( RDE ) is a propulsion system that obtains thrust using continuously existing...2014 – 12/4/2015 Summary: The rotating detonation engine ( RDE ) is a propulsion system that obtains thrust using continuously existing detonation...structure. Studies have been conducted on rotating detonation engines ( RDE ) that obtain thrust from the continuously propagating detonation waves in the

  7. Detonation Processes USSR

    Science.gov (United States)

    1960-06-06

    second and quite definite for a given combustible mixture -- was an important. cientific re- sult of these researches discovered in 18881 by four...Consequently, the pulsating structure of the front of the "rnorr.ia]" detonation should be quite comrmon. (1) See K. i. Shchelkin, " Journal of...A1 "-൚ " 4 FOR REASONS OF SPEED AND ECONOMY THIS REPORT HAS BEEN REPRODUCED ELECTRONICALLY DIPWCTLY PROM OUR CONTRACTOR’S TYPESCRIPT THIS PUBLICATION

  8. The hydrodynamic theory of detonation

    Science.gov (United States)

    Langweiler, Heinz

    1939-01-01

    This report derives equations containing only directly measurable constants for the quantities involved in the hydrodynamic theory of detonation. The stable detonation speed, D, is revealed as having the lowest possible value in the case of positive material velocity, by finding the minimum of the Du curve (u denotes the speed of the gases of combustion). A study of the conditions of energy and impulse in freely suspended detonating systems leads to the disclosure of a rarefaction front traveling at a lower speed behind the detonation front; its velocity is computed. The latent energy of the explosive passes into the steadily growing detonation zone - the region between the detonation front and the rarefaction front. The conclusions lead to a new definition of the concept of shattering power. The calculations are based on the behavior of trinitrotoluene.

  9. Forensic evidence in apparel fabrics due to stab events.

    Science.gov (United States)

    Kemp, S E; Carr, D J; Kieser, J; Niven, B E; Taylor, M C

    2009-10-30

    Stab injuries and fatalities have been reported to be the most common crimes of violence in several countries, particularly in those where access to firearms is restricted [J.M. Taupin, F.-P. Adolf, J. Robertson, Examination of damage to textiles, in: J. Robertson, M. Grieve (Eds.), Forensic Examination of Fibres, CRC Press, United States of America, 1999, pp. 65-87; A.C. Hunt, R.J. Cowling, Murder by stabbing, Forensic Sci. Int. 52 (1991) 107-112; D.A. Rouse, Patterns of stab wounds: a six year study, Med. Sci. Law 34 (1994) 67-71]. Analysis of damaged apparel may provide important information about the cause of death and the events leading up to and after the victim's final moments [M.T. Pailthorpe, N.A.G. Johnson, The private forensic scientist and the criminal justice system, in: D. Biles, J. Vernon (Eds.), Private Sector and Community Involvement in the Criminal Justice System: Conference Proceedings, vol. 23, Australian Institute of Criminology, Wellington, 1994, 231-240]. A high proportion of stab wounds occur in the chest and as this area is generally clothed many sharp force cases involve damage to fabrics [J.M. Taupin, F.-P. Adolf, J. Robertson, Examination of damage to textiles, in: J. Robertson, M. Grieve (Eds.), Forensic Examination of Fibres, CRC Press, United States of America, 1999, pp. 65-87; A.C. Hunt, R.J. Cowling, Murder by stabbing, Forensic Sci. Int. 52 (1991) 107-112; D.A. Rouse, Patterns of stab wounds: a six year study, Med. Sci. Law 34 (1994) 67-71]. The structural stabilisation and degradation of fabric due to laundering significantly alters fabric properties [S.E. Gore, R.M. Laing, C.A. Wilson, D.J. Carr, B.E. Niven, Standardizing a pre-treatment cleaning procedure and effects of application on apparel fabrics, Text. Res. J. 76 (2006) 455-464], yet the effect of such on severance morphology does not appear to have been investigated. In this work the effect of blade type (hunting knife, kitchen knife, screwdriver) on new and laundered

  10. A Study of Stab wounds in Sexual Homicides

    OpenAIRE

    Dinesh Rao

    2014-01-01

    In the present a total of 236 of stab wound Homicides were studied of which 86 were Sexual Homicides and 150 were Nonsexual Homicides. The Gender distribution had contrasting findings, in Sexual Homicides the Male to Female ratio was 1:4 whereas in Nonsexual victims the ratio was 14:1.The major age group involved in Sexual homicides were 21-30yrs whereas the Majority of the victims of Nonsexual homicides belonged to age group 21-40yrs. The sexual homicides never affected victims belonging to ...

  11. Detonation in supersonic radial outflow

    KAUST Repository

    Kasimov, Aslan R.

    2014-11-07

    We report on the structure and dynamics of gaseous detonation stabilized in a supersonic flow emanating radially from a central source. The steady-state solutions are computed and their range of existence is investigated. Two-dimensional simulations are carried out in order to explore the stability of the steady-state solutions. It is found that both collapsing and expanding two-dimensional cellular detonations exist. The latter can be stabilized by putting several rigid obstacles in the flow downstream of the steady-state sonic locus. The problem of initiation of standing detonation stabilized in the radial flow is also investigated numerically. © 2014 Cambridge University Press.

  12. Detonation in supersonic radial outflow

    KAUST Repository

    Kasimov, Aslan R.; Korneev, Svyatoslav

    2014-01-01

    We report on the structure and dynamics of gaseous detonation stabilized in a supersonic flow emanating radially from a central source. The steady-state solutions are computed and their range of existence is investigated. Two-dimensional simulations

  13. Novel uses of detonator diagnostics

    Energy Technology Data Exchange (ETDEWEB)

    Gibson, John R. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Wilde, Zakary Robert [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Tasker, Douglas George [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Francois, Elizabeth Green [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Nakamoto, Teagan Kanakanui Junichi [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Smith, Dalton Kay [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Trujillo, Christopher J. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-09-15

    A novel combination of diagnostics is being used to research the physics of detonator initiation. The explosive PETN (Pentaerythritol tetranitrate) commonly used in detonators, is also a piezo-electric material that, when sufficiently shocked, emits an electromagnetic field in the radio frequency (RF) range, along crystal fracture planes. In an effort to capture this RF signal, a new diagnostic was created. A copper foil, used as an RF antenna, was wrapped around a foam fixture encompassing a PETN pellet. Rogowski coils were used to obtain the change in current with respect to time (di/dt) the detonator circuit, in and polyvinylidene difluoride (PVDF) stress sensors were used to capture shockwave arrival time. The goal of these experiments is to use these diagnostics to study the reaction response of a PETN pellet of known particle size to shock loading with various diagnostics including an antenna to capture RF emissions. Our hypothesis is that RF feedback may signify the rate of deflagration to detonation transition (DDT) or lack thereof. The new diagnostics and methods will be used to determine the timing of start of current, bridge burst, detonator breakout timing and RF generated from detonation. These data will be compared to those of currently used diagnostics in order to validate the accuracy of these new methods. Future experiments will incorporate other methods of validation including dynamic radiography, optical initiation and use of magnetic field sensors.

  14. Light-initiated detonation systems

    Science.gov (United States)

    Cooper, Stafford S.; Malone, Philip G.; Bartholomew, Stephen W.; Necker, William J.

    1986-09-01

    Numerous light sources could be employed in detonation systems, but lasers have the most efficient coupling to optical fibers and can generate energetic light pulses required for detonation. Flash lamp-pumped, solid state lasers are presently the most useful light source for explosive initiation. Laser diodes in current production cannot generate enough energy for practical applications. The most useful optical fiber for blast line application is a step index fiber with a large core-to-cladding ratio. The large core minimizes energy losses due to misalignment core of fibers in connectors. Couplers that involve mechanically crimped connectors and cleaved fibers, rather than the epoxy-cemented connectors with polished fibers, provide superior energy transmission due to the reduced carbonization at the fiber end. Detonators for optical initiation systems are similar in basic construction to those employed in electrical initiation systems. Explosive and pyrotechnic charges can also be similar. Either primary or secondary explosives can be initiated in present laser-based systems. Two laser detonation systems are presently accessible; a multiple-shot laser with a single-shot, single fiber system designed for use with detonators containing primary explosives. Additional research related to development of low-energy, photoreactive detonators, continuity checking techniques and improved connectors and fibers can produce significant improvements in presently fielded systems.

  15. The use of etoricoxib to treat an idiopathic stabbing headache: a case report

    Directory of Open Access Journals (Sweden)

    O'Connor Mortimer B

    2007-09-01

    Full Text Available Abstract According to the International Headache Society, idiopathic stabbing headache (ISH, an indomethacin-responsive headache syndrome, is a paroxysmal disorder of short duration manifested as head pain occurring as a single stab or a series of stabs involving the area supplied in the distribution of the first division of the trigeminal nerve. Stabs last for approximately a few seconds, occurring and recurring from once to multiple times per day in an irregular frequency, with no underlying attributable disorder. Previously indomethacin was the principle treatment option for ISH, despite therapeutic failure in up to 35% of cases, until reports showed gabapentin, melatonin and selective cyclo-oxygenase-2 (COX-2 inhibitors were also possibly effective. In this report we present the full case report of an 88 year old lady with a history of untreated ISH where etoricoxib, a selective COX-2 inhibitor, was used to effectively treat her ISH.

  16. Stab Resistance of Shear Thickening Fluid (STF)-Kevlar Composites for Body Armor Applications

    National Research Council Canada - National Science Library

    Egres Jr., R. G; Decker, M. J; Halbach, C. J; Lee, Y. S; Kirkwood, J. E; Kirwood, K. M; Wagner, N. J; Wetzel, E. D

    2004-01-01

    The stab resistance of shear thickening fluid (STF)-Kevlar and STF-Nylon fabric composites are investigated and found to exhibit significant improvements over neat fabric targets of equivalent areal density...

  17. Impulse generation by detonation tubes

    Science.gov (United States)

    Cooper, Marcia Ann

    Impulse generation with gaseous detonation requires conversion of chemical energy into mechanical energy. This conversion process is well understood in rocket engines where the high pressure combustion products expand through a nozzle generating high velocity exhaust gases. The propulsion community is now focusing on advanced concepts that utilize non-traditional forms of combustion like detonation. Such a device is called a pulse detonation engine in which laboratory tests have proven that thrust can be achieved through continuous cyclic operation. Because of poor performance of straight detonation tubes compared to conventional propulsion systems and the success of using nozzles on rocket engines, the effect of nozzles on detonation tubes is being investigated. Although previous studies of detonation tube nozzles have suggested substantial benefits, up to now there has been no systematic investigations over a range of operating conditions and nozzle configurations. As a result, no models predicting the impulse when nozzles are used exist. This lack of data has severely limited the development and evaluation of models and simulations of nozzles on pulse detonation engines. The first experimental investigation measuring impulse by gaseous detonation in plain tubes and tubes with nozzles operating in varying environment pressures is presented. Converging, diverging, and converging-diverging nozzles were tested to determine the effect of divergence angle, nozzle length, and volumetric fill fraction on impulse. The largest increases in specific impulse, 72% at an environment pressure of 100 kPa and 43% at an environment pressure of 1.4 kPa, were measured with the largest diverging nozzle tested that had a 12° half angle and was 0.6 m long. Two regimes of nozzle operation that depend on the environment pressure are responsible for these increases and were first observed from these data. To augment this experimental investigation, all data in the literature regarding

  18. STAB INJURY: RETROSPECTIVE AND PROSPECTIVE STUDY IN TERTIARY CENTRE S IN CENTRAL INDIA

    OpenAIRE

    Raikwar; Odiya; Ashish; Sachin

    2015-01-01

    AIMS AND OBJECTIVES: The aim of this study was to , 1. E valuate the incidence of stab injuries admitting in our institute, t o know various parameter and its association with injuries such as age group, sex ratio, clinical presentation . 2. V arious surgical interventi on and conservative treatment according the nature of stab injuries and through examination. 3. M orbidity and mortality of these patients , settings and design . ...

  19. Non-fatal suicide attempt by intentional stab wound: Clinical management, psychiatric assessment, and multidisciplinary considerations

    Directory of Open Access Journals (Sweden)

    James M Badger

    2012-01-01

    Full Text Available Background: Suicide by means of self-inflicted stab wounds is relatively uncommon and little is known about this population and their management. Materials and Methods: Retrospective review of adult trauma patients admitted to our Level-1 trauma center between January 2005 and October 2009 for management of non-fatal, self-inflicted stab wounds. Results: Fifty-eight patients were evaluated with self-inflicted stab wounds. Four patients died due to their injuries (mortality, 7%. Of the non-fatal stab wounds, 78% were male ranging in age from 19-82 (mean: 45 years. The most common injury sites were the abdomen (46%, neck (33%, and chest (20%. In terms of operative interventions, 56% of abdominal operations were therapeutic, whereas 100% of neck and chest operations were therapeutic. When assessing for suicidal ideation, 44 patients (81% admitted to suicidal intentions whereas 10 patients (19% described "accidental" circumstances. Following psychiatric evaluation, 8 of the 10 patients with "accidental injuries" were found to be suicidal. Overall, 54 patients (98% met criteria for a formal psychiatric diagnosis with 48 patients (89% necessitating inpatient or outpatient psychiatric assistance at discharge. Conclusions: Compared to previous reports of stab wounds among trauma patients, patients with self- inflicted stab wounds may have a higher incidence of operative interventions and significant injuries depending on the stab location. When circumstances surrounding a self-inflicted stabbing are suspicious, additional interviews by psychiatric care providers may uncover a suicidal basis to the event. Given the increased incidence of psychiatric illness in this population, it is imperative to approach the suicidal patient in a multidisciplinary fashion.

  20. Scissors stab wound to the cervical spinal cord at the craniocervical junction.

    Science.gov (United States)

    Zhang, Xiao-Yong; Yang, Ying-Ming

    2016-06-01

    Stab wounds resulting in spinal cord injury of the craniocervical junction are rare. A scissors stab wound to the cervical spinal cord has been reported only once in the literature. This paper aimed to report a case of Brown-Séquard-plus syndrome in an 8-year-old boy secondary to a scissors stab wound at the craniocervical junction. Case report and review of the literature. Case report of an 8-year-old boy accidentally stabbed in the neck by scissors, which were thrown as a dart. The case study of an 8-year-old boy who was hospitalized because of a scissors stab wound at the craniocervical junction. The patient developed Brown-Séquard-plus syndrome on the left side of the body. Magnetic resonance imaging revealed a laceration of the spinal cord at the craniocervical junction with cerebrospinal fluid leakage. Careful cleansing and interrupted sutures of the wounds were performed to prevent cerebrospinal fluid leakage. Rehabilitation therapy was performed 2 days later. A follow-up examination revealed complete recovery of the neurologic deficit 8 months post-injury. Treatment of scissors stab wounds to the cervical spinal cord, whether conservative management or thorough surgical exploration, should be individualized based on history, examination, and imaging. As shown in this case report, despite conservative management, complete recovery, which was unexpected, was attributed to the initial mild laceration of the spinal cord and ipsilateral spinal cord functional compensation. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. Detonation in TATB Hemispheres

    Energy Technology Data Exchange (ETDEWEB)

    Druce, B; Souers, P C; Chow, C; Roeske, F; Vitello, P; Hrousis, C

    2004-03-17

    Streak camera breakout and Fabry-Perot interferometer data have been taken on the outer surface of 1.80 g/cm{sup 3} TATB hemispherical boosters initiated by slapper detonators at three temperatures. The slapper causes breakout to occur at 54{sup o} at ambient temperatures and 42{sup o} at -54 C, where the axis of rotation is 0{sup o}. The Fabry velocities may be associated with pressures, and these decrease for large timing delays in breakout seen at the colder temperatures. At room temperature, the Fabry pressures appear constant at all angles. Both fresh and decade-old explosive are tested and no difference is seen. The problem has been modeled with reactive flow. Adjustment of the JWL for temperature makes little difference, but cooling to -54 C decreases the rate constant by 1/6th. The problem was run both at constant density and with density differences using two different codes. The ambient code results show that a density difference is probably there but it cannot be quantified.

  2. Detonation in TATB hemispheres

    Energy Technology Data Exchange (ETDEWEB)

    Druce, Robert L.; Souers, P. Clark; Chow, Charles; Roeske, Franklin; Vitello, Peter; Hrousis, Constantine [Lawrence Livermore National Laboratory, Livermore, CA, 94550 (United States)

    2005-04-01

    Streak camera breakout and Fabry-Perot interferometer data have been taken on the outer surface of 1.80 g/cm{sup 3} TATB (triamino-trinitrobenzene) hemispherical boosters initiated by slapper detonators at three temperatures. The slapper causes breakout to occur at 54 at ambient temperatures and 42 at -54 C, where the axis of rotation is 0 . The Fabry velocities may be associated with pressures, and these decrease for large timing delays in breakout seen at the colder temperatures. At room temperature, the Fabry pressures appear constant at all angles. Both fresh and decade-old explosive are tested and no difference is seen. The problem has been modeled with reactive flow. Adjustment of the JWL for temperature makes little difference, but cooling to -54 C decreases the rate constant by 1/6th. The problem was run both at constant density and with density differences using two different codes. The ambient code results show that a density difference is probably present, but it cannot be quantified. (Abstract Copyright [2005], Wiley Periodicals, Inc.)

  3. Stability of cosmological detonation fronts

    Science.gov (United States)

    Mégevand, Ariel; Membiela, Federico Agustín

    2014-05-01

    The steady-state propagation of a phase-transition front is classified, according to hydrodynamics, as a deflagration or a detonation, depending on its velocity with respect to the fluid. These propagation modes are further divided into three types, namely, weak, Jouguet, and strong solutions, according to their disturbance of the fluid. However, some of these hydrodynamic modes will not be realized in a phase transition. One particular cause is the presence of instabilities. In this work we study the linear stability of weak detonations, which are generally believed to be stable. After discussing in detail the weak detonation solution, we consider small perturbations of the interface and the fluid configuration. When the balance between the driving and friction forces is taken into account, it turns out that there are actually two different kinds of weak detonations, which behave very differently as functions of the parameters. We show that the branch of stronger weak detonations are unstable, except very close to the Jouguet point, where our approach breaks down.

  4. Pulse Detonation Physiochemical and Exhaust Relaxation Processes

    Science.gov (United States)

    2006-05-01

    based on total time to detonation and detonation percentage. Nomenclature A = Arrehenius Constant Ea = Activation Energy Ecrit = Critical...the precision uncertainties vary for each data point. Therefore, the total experimental uncertainty will vary by data point. A comprehensive bias

  5. Detonation Jet Engine. Part 1--Thermodynamic Cycle

    Science.gov (United States)

    Bulat, Pavel V.; Volkov, Konstantin N.

    2016-01-01

    We present the most relevant works on jet engine design that utilize thermodynamic cycle of detonative combustion. The efficiency advantages of thermodynamic detonative combustion cycle over Humphrey combustion cycle at constant volume and Brayton combustion cycle at constant pressure were demonstrated. An ideal Ficket-Jacobs detonation cycle, and…

  6. Benign positional vertigo

    Science.gov (United States)

    Vertigo - positional; Benign paroxysmal positional vertigo; BPPV: dizziness- positional ... Benign positional vertigo is also called benign paroxysmal positional vertigo (BPPV). It is caused by a problem in the inner ear. ...

  7. STAB INJURY: RETROSPECTIVE AND PROSPECTIVE STUDY IN TERTIARY CENTRE S IN CENTRAL INDIA

    Directory of Open Access Journals (Sweden)

    Raikwar

    2015-07-01

    Full Text Available AIMS AND OBJECTIVES: The aim of this study was to , 1. E valuate the incidence of stab injuries admitting in our institute, t o know various parameter and its association with injuries such as age group, sex ratio, clinical presentation . 2. V arious surgical interventi on and conservative treatment according the nature of stab injuries and through examination. 3. M orbidity and mortality of these patients , settings and design . The study was conducted in a retrospective and prospec tive manner and included cases b etween January 2009 and September 2013. METHODS AND MATERIAL S: 424 patients admitted with stab injuries in ICU and ward . Various surgical interventions were done according to standard indication such as laparotomies , thoracotomies, vascular repair etc. , and resul ts reported. RESULTS: Out of 424 patients t here were over all 413 mal es (97.4% and 11 female s (2.6% highest number of cases (226 in the third decade(21 - 30 i.e. 53.3% maximum number of cases are from 11 - 40 yrs. Majority of the stab wounds were homicidal in nature comprising 386 cases i.e. 91 % followed by are accidental. Chaku ( knife were the most common weapon . The Chaku was used in 351 cases i.e. 82.8% maximun numbers of patients 309 were presented with localised tende r ness at site of stab injury i.e 72.87%. In the perspective of management 244 abdominal stab that there were total 189(44.6% exploratory laparotomy . In 189 laparotomies peritoneal breech in 114 patients on local examination / exploration was the major indic ation there were 114 i.e ., 60.3% CONCLUSION: Stab injuri es are becoming common now a days because people often try to settle interpersonal relationship and political problems by mean of stabbing, although its incidence more in our country as compare d to European studies because of overpopulation unemployment and poverty. Incidence of stab injury can be reduced by improving the social morale of people especially the younger generation by

  8. Detonation of hydrogen-air mixtures

    International Nuclear Information System (INIS)

    Lee, J.H.S.; Knystautas, R.; Benedick, W.B.

    1983-01-01

    The detonation of a hydrogen-air cloud subsequent to an accidental release of hydrogen into ambient surroundings cannot be totally ruled out in view of the relative sensitivity of the hydrogen-air system. The present paper investigates the key parameters involved in hydrogen-air detonations and attempts to establish quantitative correlations between those that have important practical implications. Thus, for example, the characteristic length scale lambda describing the cellular structure of a detonation front is measured for a broad range of hydrogen-air mixtures and is quantitatively correlated with the key dynamic detonation properties such as detonability, transmission and initiation

  9. Turbulent deflagrations, autoignitions, and detonations

    KAUST Repository

    Bradley, Derek

    2012-09-01

    Measurements of turbulent burning velocities in fan-stirred explosion bombs show an initial linear increase with the fan speed and RMS turbulent velocity. The line then bends over to form a plateau of high values around the maximum attainable burning velocity. A further increase in fan speed leads to the eventual complete quenching of the flame due to increasing localised extinctions because of the flame stretch rate. The greater the Markstein number, the more readily does flame quenching occur. Flame propagation along a duct closed at one end, with and without baffles to increase the turbulence, is subjected to a one-dimensional analysis. The flame, initiated at the closed end of the long duct, accelerates by the turbulent feedback mechanism, creating a shock wave ahead of it, until the maximum turbulent burning velocity for the mixture is attained. With the confining walls, the mixture is compressed between the flame and the shock plane up to the point where it might autoignite. This can be followed by a deflagration to detonation transition. The maximum shock intensity occurs with the maximum attainable turbulent burning velocity, and this defines the limit for autoignition of the mixture. For more reactive mixtures, autoignition can occur at turbulent burning velocities that are less than the maximum attainable one. Autoignition can be followed by quasi-detonation or fully developed detonation. The stability of ensuing detonations is discussed, along with the conditions that may lead to their extinction. © 2012 by Pleiades Publishing, Ltd.

  10. Airbreathing Pulse Detonation Engine Performance

    Science.gov (United States)

    Povinelli, Louis A.; Yungster, Shaye

    2002-01-01

    This paper presents performance results for pulse detonation engines (PDE) taking into account the effects of dissociation and recombination. The amount of sensible heat recovered through recombination in the PDE chamber and exhaust process was found to be significant. These results have an impact on the specific thrust, impulse and fuel consumption of the PDE.

  11. Numerical Computation of Detonation Stability

    KAUST Repository

    Kabanov, Dmitry

    2018-01-01

    Then we investigate the Fickett’s detonation analogue coupled with a particular reaction-rate expression. In addition to the linear stability analysis of this model, we demonstrate that it exhibits rich nonlinear dynamics with multiple bifurcations and chaotic behavior.

  12. Experimental study of thermal comfort on stab resistant body armor.

    Science.gov (United States)

    Ji, Tingchao; Qian, Xinming; Yuan, Mengqi; Jiang, Jinhui

    2016-01-01

    This research aims to investigate the impacts of exercise intensity and sequence on human physiology parameters and subjective thermal sensation when wearing stab resistant body armor under daily working conditions in China [26 and 31 °C, 45-50 % relative humidity (RH)], and to investigate on the relationship between subjective judgments and objective parameters. Eight male volunteers were recruited to complete 3 terms of exercises with different velocity set on treadmill for 90 min at 26 °C and 31 °C, 45-50 % RH. In Exercise 1 volunteers were seated during the test. In Exercise 2, volunteers walked with the velocity of 3 km/h in the first 45 min and 6 km/h in the left 45 min. In Exercise 3, volunteers walked with the velocity of 6 km/h in the first 45 min and 3 km/h in the left 45 min. The body core temperature, skin temperature and subjective judgments were recorded during the whole process. Analysis of variance was performed among all the tests. Individual discrepancy of Exercise 1 is larger than that of Exercise 2 and 3. On the premise of the same walking distance and environmental conditions, core temperature in Exercise 3 is about 0.2 °C lower than that in Exercise 2 in the end; and with the velocity decrease from 6 km/h to 3 km/h in the end, thermal tolerance of Exercise 3 is about 1 degree lower than that in Exercise 2. Skin temperatures of human trunk were at least 1 °C higher than that of limbs. Activity narrows the individual discrepancy on core temperature. Within experimental conditions, decreasing of intensity at last stage makes the core temperature lower and the whole process much tolerable. The core temperature is more sensitive to the external disturbance on the balance of the whole body, and it can reflect the subjective thermal sensation and physical exertion.

  13. Development of a high-density nonwoven structure to improve the stab resistance of protective clothing material.

    Science.gov (United States)

    Bao, Limin; Wang, Yanling; Baba, Takeichiro; Fukuda, Yasuhiro; Wakatsuki, Kaoru; Morikawa, Hideaki

    2017-12-07

    The purpose of this research was to enhance the stab resistance of protective clothing material by developing a new high-density nonwoven structure. Ice picks often injure Japanese police officers due to the strict regulation of swords in the country. Consequently, this study was designed to improve stab resistance against ice picks. Most existing anti-stab protective clothing research has focused on various fabrics impregnated with resin, an approach that brings with it problems of high cost and complicated processing. Seldom has research addressed the potential for improving stab resistance by using nonwoven structures, which exhibit better stab resistance than fabric. In this research, we prepared a series of nonwoven structures with densities ranging from about 0.14 g/cm 3 to 0.46 g/cm 3 by varying the number of stacked layers of Kevlar/polyester nonwoven under a hot press. We then proposed two methods for producing such hot-press nonwovens: the multilayer hot-press method and the monolayer hot-press method. Stab resistance was evaluated according to NIJ Standard-0115.00. We also investigated the relationship among nonwoven density, stab resistance, and flexural rigidity, and here we discuss the respective properties of the two proposed methods. Our results show that stab resistance and flexural rigidity increase with nonwoven density, but flexural rigidity of nonwovens prepared using the monolayer hot-press method only shows a slight change as nonwoven density increases. Though the two methods exhibit little difference in maximum load, the flexural rigidity of nonwovens prepared using the monolayer hot-press method is much lower, which contributes to superior wear comfort. Finally, we investigated the mechanism behind the stabbing process. Stabbing with an ice pick is a complicated process that involves many factors. Our findings indicate that nonwovens stop penetration primarily in two ways: nonwoven deformation and fiber fractures.

  14. Detonation velocity in poorly mixed gas mixtures

    Science.gov (United States)

    Prokhorov, E. S.

    2017-10-01

    The technique for computation of the average velocity of plane detonation wave front in poorly mixed mixture of gaseous hydrocarbon fuel and oxygen is proposed. Here it is assumed that along the direction of detonation propagation the chemical composition of the mixture has periodic fluctuations caused, for example, by layered stratification of gas charge. The technique is based on the analysis of functional dependence of ideal (Chapman-Jouget) detonation velocity on mole fraction (with respect to molar concentration) of the fuel. It is shown that the average velocity of detonation can be significantly (by more than 10%) less than the velocity of ideal detonation. The dependence that permits to estimate the degree of mixing of gas mixture basing on the measurements of average detonation velocity is established.

  15. Numerical Computation of Detonation Stability

    KAUST Repository

    Kabanov, Dmitry

    2018-06-03

    Detonation is a supersonic mode of combustion that is modeled by a system of conservation laws of compressible fluid mechanics coupled with the equations describing thermodynamic and chemical properties of the fluid. Mathematically, these governing equations admit steady-state travelling-wave solutions consisting of a leading shock wave followed by a reaction zone. However, such solutions are often unstable to perturbations and rarely observed in laboratory experiments. The goal of this work is to study the stability of travelling-wave solutions of detonation models by the following novel approach. We linearize the governing equations about a base travelling-wave solution and solve the resultant linearized problem using high-order numerical methods. The results of these computations are postprocessed using dynamic mode decomposition to extract growth rates and frequencies of the perturbations and predict stability of travelling-wave solutions to infinitesimal perturbations. We apply this approach to two models based on the reactive Euler equations for perfect gases. For the first model with a one-step reaction mechanism, we find agreement of our results with the results of normal-mode analysis. For the second model with a two-step mechanism, we find that both types of admissible travelling-wave solutions exhibit the same stability spectra. Then we investigate the Fickett’s detonation analogue coupled with a particular reaction-rate expression. In addition to the linear stability analysis of this model, we demonstrate that it exhibits rich nonlinear dynamics with multiple bifurcations and chaotic behavior.

  16. A summary of hydrogen-air detonation experiments

    International Nuclear Information System (INIS)

    Guirao, C.M.; Knystautas, R.; Lee, J.H.

    1989-05-01

    Dynamic detonation parameters are reviewed for hydrogen-air-diluent detonations and deflagration-to-detonation transitions (DDT). These parameters include the characteristic chemical length scale, such as the detonation cell width, associated with the three-dimensional cellular structure of detonation waves, critical transmission conditions of confined detonations into unconfined environments, critical initiation energy for unconfined detonations, detonability limits, and critical conditions for DDT. The detonation cell width, which depends on hydrogen and diluent concentrations, pressure, and temperature, is an important parameter in the prediction of critical geometry-dependent conditions for the transmission of confined detonations into unconfined environments and the critical energies for the direct initiation of unconfined detonations. Detonability limits depend on both initial and boundary conditions and the limit has been defined as the onset of single head spin. Four flame propagation regimes have been identified and the criterion for DDT in a smooth tube is discussed. 108 refs., 28 figs., 5 tabs

  17. Gaseous detonation initiation via wave implosion

    Science.gov (United States)

    Jackson, Scott Irving

    Efficient detonation initiation is a topic of intense interest to designers of pulse detonation engines. This experimental work is the first to detonate propane-air mixtures with an imploding detonation wave and to detonate a gas mixture with a non-reflected, imploding shock. In order to do this, a unique device has been developed that is capable of generating an imploding toroidal detonation wave inside of a tube from a single ignition point without any obstruction to the tube flow path. As part of this study, an initiator that creates a large-aspect-ratio planar detonation wave in gas-phase explosive from a single ignition point has also been developed. The effectiveness of our initiation devices has been evaluated. The minimum energy required by the imploding shock for initiation was determined to scale linearly with the induction zone length, indicating the presence of a planar initiation mode. The imploding toroidal detonation initiator was found to be more effective at detonation initiation than the imploding shock initiator, using a comparable energy input to that of current initiator tubes.

  18. Influence of Chemical Surface Modification of Woven Fabrics on Ballistic and Stab Protection of Multilayer Packets

    Directory of Open Access Journals (Sweden)

    Diana GRINEVIČIŪTĖ

    2014-06-01

    Full Text Available In order to achieve enhanced protective and wear (flexibility, less bulkiness properties of ballistic and stab protecting panels the investigation of chemical surface modification of woven p-aramid fabrics was performed applying different chemical composition shear thickening fluid (STF which improves friction inside fabric structure. For the chemical treatment silicic acid and acrylic dispersion water solutions were used and influence of their different concentrations on panels’ protective properties were investigated. Results of ballistic tests of multilayer protective panel have revealed that shear thickening effect was negligible when shooting at high energy range (E > 440 J. Determination of stab resistance of p-aramid panels has shown that different chemical composition of STFs had different influence on protective properties of the panels. Application of low concentrations of silicic acid determined higher stab resistance values comparing to higher concentrations of acrylic dispersion water solutions. At this stage of research stab tests results as ballistic ones determined that STF application for multilayer p-aramid fabrics protective panels is more efficient at low strike energy levels. DOI: http://dx.doi.org/10.5755/j01.ms.20.2.3138

  19. Abdominal stab wound protocol: prospective study documents applicability for widespread use.

    Science.gov (United States)

    Rosemurgy, A S; Albrink, M H; Olson, S M; Sherman, H; Albertini, J; Kramer, R; Camps, M; Reiss, A

    1995-02-01

    Traditionally, stab wounds violating the abdominal wall fascia led to exploratory celiotomy that was often nontherapeutic. In an attempt to limit the number of nontherapeutic celiotomies (NTC), we devised a protocol to prospectively study stab wounds violating the anterior abdominal wall fascia. Through protocol, abdominal stab wounds were explored in stable adults. If the anterior fascia was violated, paracentesis and, if necessary, peritoneal lavage was undertaken in the absence of previous abdominal surgery. If evisceration was noted, it was reduced and the patient lavaged. Fascial penetration was noted in 72 patients. 46 patients underwent celiotomy: because of shock/peritonitis in 8 (2 NTC), fascial penetration with a history of previous celiotomy in 7 (5 NTC), positive paracentesis in 20 (5 NTC), or positive lavage in 10 (4 NTC). One patient underwent late celiotomy without ill-effect after a negative lavage because she subsequently developed fever and localized peritonitis (ice pick injury to cecum). Eleven patients had evisceration; nine underwent celiotomy. Patients with abdominal stab wounds can be selectively managed safely. More than one-third with fascial penetration, some with evisceration, avoided exploration. Only one patient underwent delayed celiotomy and did so without detriment. Nontherapeutic celiotomy rates were highest in patients with previous abdominal surgery who, thereby, could not undergo paracentesis/lavage; excluding these patients, the nontherapeutic celiotomy rate was 17% (11/65) for those with fascial penetration.

  20. Utility of Chest Computed Tomography after a "Normal" Chest Radiograph in Patients with Thoracic Stab Wounds.

    Science.gov (United States)

    Nguyen, Brian M; Plurad, David; Abrishami, Sadaf; Neville, Angela; Putnam, Brant; Kim, Dennis Y

    2015-10-01

    Chest computed tomography (CCT) is used to screen for injuries in hemodynamically stable patients with penetrating injury. We aim to determine the incidence of missed injuries detected on CCT after a negative chest radiograph (CXR) in patients with thoracic stab wounds. A 10-year retrospective review of a Level I trauma center registry was performed on patients with thoracic stab wounds. Patients who were hemodynamically unstable or did not undergo both CXR and CCT were excluded. Patients with a negative CXR were evaluated to determine if additional findings were diagnosed on CCT. Of 386 patients with stab wounds to the chest, 154 (40%) underwent both CXR and CCT. One hundred and fifteen (75%) had a negative screening CXR. CCT identified injuries in 42 patients (37%) that were not seen on CXR. Pneumothorax and/or hemothorax occurred in 40 patients (35%), of which 14 patients underwent tube thoracostomy. Two patients had hemopericardium on CCT and both required operative intervention. Greater than one-third of patients with a normal screening CXR were found to have abnormalities on CCT. Future studies comparing repeat CXR to CCT are required to further define the optimal diagnostic strategy in patients with stab wounds to chest after normal screening CXR.

  1. Eestlane säästab idaeurooplasest kaks korda vähem / Margit Aedla

    Index Scriptorium Estoniae

    Aedla, Margit, 1970-

    2006-01-01

    Eestlaste vähesest säästmisest ja selle põhjustest. Lisa: Miks peaks rohkem investeerima? Graafik: Võrdlus teiste Kesk- ja Ida-Euroopa riikidega näitab, et eestlased säästavad vähem. Diagramm: Enamik eestlasi säästab täna pensioni II samba varal

  2. Evaluation of Straight and Swept Ramp Obstacles on Enhancing Deflagration-to-Detonation Transition in Pulse Detonation Engines

    Science.gov (United States)

    2006-12-01

    This led to the work of H. Le Chatelier and E. Mallard, who in 1883 conducted experiments to examine the detonation process more closely. Their work...describes the history of research into detonation and the principles that govern detonation theory. A. DETONATION HISTORY 1. Early Research in...these favorable properties and for a propulsion system and is a principle means of detonation initiation in pulse detonation engines. DDT refers to a

  3. Pulse Detonation Assessment for Alternative Fuels

    Directory of Open Access Journals (Sweden)

    Muhammad Hanafi Azami

    2017-03-01

    Full Text Available The higher thermodynamic efficiency inherent in a detonation combustion based engine has already led to considerable interest in the development of wave rotor, pulse detonation, and rotating detonation engine configurations as alternative technologies offering improved performance for the next generation of aerospace propulsion systems, but it is now important to consider their emissions also. To assess both performance and emissions, this paper focuses on the feasibility of using alternative fuels in detonation combustion. Thus, the standard aviation fuels Jet-A, Acetylene, Jatropha Bio-synthetic Paraffinic Kerosene, Camelina Bio-synthetic Paraffinic Kerosene, Algal Biofuel, and Microalgae Biofuel are all asessed under detonation combustion conditions. An analytical model accounting for the Rankine-Hugoniot Equation, Rayleigh Line Equation, and Zel’dovich–von Neumann–Doering model, and taking into account single step chemistry and thermophysical properties for a stoichiometric mixture, is applied to a simple detonation tube test case configuration. The computed pressure rise and detonation velocity are shown to be in good agreement with published literature. Additional computations examine the effects of initial pressure, temperature, and mass flux on the physical properties of the flow. The results indicate that alternative fuels require higher initial mass flux and temperature to detonate. The benefits of alternative fuels appear significant.

  4. 14 CFR 33.47 - Detonation test.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Detonation test. 33.47 Section 33.47 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES Block Tests; Reciprocating Aircraft Engines § 33.47 Detonation test. Each engine...

  5. Tritium labeling of detonation nanodiamonds.

    Science.gov (United States)

    Girard, Hugues A; El-Kharbachi, Abdelouahab; Garcia-Argote, Sébastien; Petit, Tristan; Bergonzo, Philippe; Rousseau, Bernard; Arnault, Jean-Charles

    2014-03-18

    For the first time, the radioactive labeling of detonation nanodiamonds was efficiently achieved using a tritium microwave plasma. According to our measurements, the total radioactivity reaches 9120 ± 120 μCi mg(-1), with 93% of (3)H atoms tightly bonded to the surface and up to 7% embedded into the diamond core. Such (3)H doping will ensure highly stable radiolabeled nanodiamonds, on which surface functionalization is still allowed. This breakthrough opens the way to biodistribution and pharmacokinetics studies of nanodiamonds, while this approach can be scalable to easily treat bulk quantities of nanodiamonds at low cost.

  6. Initiation of Gaseous Detonation by Conical Projectiles

    Science.gov (United States)

    Verreault, Jimmy

    Initiation and stabilization of detonation by hypersonic conical projectiles launched into combustible gas mixtures is investigated. This phenomenon must be understood for the design and optimization of specific hypersonic propulsion devices, such as the oblique detonation wave engine and the ram accelerator. The criteria for detonation initiation by a projectile is also related to fundamental aspects of detonation research, such as the requirement for direct initiation of a detonation by a blast wave. Experimental results of this problem also offer useful references for validation of numerical and theoretical modeling. Projectiles with cone half angles varying from 15° to 60° were launched into stoichiometric mixtures of hydrogen/oxygen with 70% argon dilution at initial pressures between 10 and 200 kPa. The projectiles were launched from a combustion-driven gas gun at velocities up to 2.2 km/s (corresponding to 133% of the Chapman Jouguet velocity). Pictures of the flowfields generated by the projectiles were taken via Schlieren photography. Five combustion regimes were observed about the projectile ranging from prompt and delayed oblique detonation wave formation, combustion instabilities, a wave splitting, and an inert shock wave. Two types of transition from the prompt oblique detonation wave regime to the inert shock regime were observed. The first (the delayed oblique detonation wave regime) showed an inert shock attached to the tip of the projectile followed by a sharp kink at the onset of an oblique detonation wave; this regime occurred by decreasing the cone angle at high mixture pressures. The second (the combustion instabilities regime) exhibited large density gradients due to combustion ignition and quenching phenomena; this regime occurred by decreasing the mixture pressure at large cone angles. A number of theoretical models were considered to predict critical conditions for the initiation of oblique detonations. The Lee-Vasiljev model agreed

  7. STABILITY OF PLASMIDS IN 5 STRAINS OF SALMONELLA MAINTAINED IN STAB CULTURE AT DIFFERENT TEMPERATURES

    DEFF Research Database (Denmark)

    Olsen, J. E.; Brown, D. J.; Baggesen, Dorte Lau

    1994-01-01

    Four strains of Salmonella berta and one of Salm. enteritidis were stored as stab cultures in sugar-free agar at 5 degrees, 22 degrees and 30 degrees C and in 15% glycerol at -80 degrees C. The stability of the plasmid profiles in each of the strains was monitored over a period of 2.5 years....... Plasmid profiles were stable in all strains stored at -80 degrees C, and only six of 450 colonies examined from strains kept in sugar-free agar at 5 degrees C had lost plasmid molecules. Seventy of 440 colonies from stab cultures that were kept at 22 degrees C, and 71 of 440 colonies at 30 degrees C...

  8. REVERSIBLE CORTICAL BLINDNESS FOLLOWING SUCCESSFUL SURGICAL REPAIR OF TWO STAB WOUNDS IN THE HEART

    Directory of Open Access Journals (Sweden)

    Zaiton A

    2008-01-01

    Full Text Available This report describes a case of cortical blindness that followed successful surgical repair of two stab wounds in the heart in a 29-year old Libyan man. The patient presented in a state of pre cardiac arrest (shock and low cardiac output status, following multiple chest stab wounds. Chest tube was immediately inserted. Surgery was urgently performed suturing the two wounds; in the root of the aorta and in the left ventricle, and haemostasis was secured. Cardiac arrest was successfully prevented. The patient recovered smoothly, but 24 hours later he declared total blindness. Ophtalmic and neurological examinations and investigations that included fundoscopy, Electroencephalograms (EEGs and Computed Tomography Scans revealed no abnormalities, apart from absence of alpha waves in the EEGs. We diagnosed the case as cortical blindness and continued caring for the patient conservatively. Three days later, the patient regained his vision gradually and was discharged on the 7th postoperative day without any remarks.

  9. Astrocyte morphology after cortical stab wound revealed by single-cell confocal 3D morphometry

    Czech Academy of Sciences Publication Activity Database

    Chvátal, Alexandr; Anděrová, Miroslava; Petřík, David; Syková, Eva

    č. 2 (2003), s. 63 ISSN 0894-1491. [European Meeting on Glia l Cell Function in Health and Disease /6./. Berlín, 03.09.2003-06.09.2003] R&D Projects: GA ČR GA305/02/1528; GA MŠk LN00A065 Institutional research plan: CEZ:AV0Z5039906; CEZ:MSM 111300004 Keywords : cortical stab wound * morphometry Subject RIV: FH - Neurology Impact factor: 4.677, year: 2003

  10. IP-telefon säästab oluliselt sidekulusid / Kristjan Otsmann

    Index Scriptorium Estoniae

    Otsmann, Kristjan, 1971-

    2005-01-01

    Telekomifirma Norby Telecomi poolt pakutavast IP-telefonist ehk helistamisest läbi Interneti, millega saab vähendada sidekulusid mitmeid kordi. Erinevatest internetipõhise kõnesidelahenduse lisateenustest. Vt. samas: Saaremaa Spa Hotellid säästab tuhandeid kroone kuus [intervjuu Saaremaa Spa Hotellide IT-juhiga Andri Võrguga]; Kuus olulist tööd enne IP-lahenduse tellimist

  11. Reinforced concrete wall under hydrogen detonation

    International Nuclear Information System (INIS)

    Saarenheimo, A.

    2000-11-01

    The structural integrity of a reinforced concrete wall in the BWR reactor building under hydrogen detonation conditions has been analysed. Of particular interest is whether the containment integrity can be jeopardised by an external hydrogen detonation. The load carrying capacity of a reinforced concrete wall was studied. The detonation pressure loads were estimated with computerised hand calculations assuming a direct initiation of detonation and applying the strong explosion theory. The results can be considered as rough and conservative estimates for the first shock pressure impact induced by a reflecting detonation wave. Structural integrity may be endangered due to slow pressurisation or dynamic impulse loads associated with local detonations. The static pressure following the passage of a shock front may be relatively high, thus this static or slowly decreasing pressure after a detonation may damage the structure severely. The mitigating effects of the opening of a door on pressure history and structural response were also studied. The non-linear behaviour of the wall was studied under detonations corresponding a detonable hydrogen mass of 0.5 kg and 1.428 kg. Non-linear finite element analyses of the reinforced concrete structure were carried out by the ABAQUS/Explicit program. The reinforcement and its non-linear material behaviour and the tensile cracking of concrete were modelled. Reinforcement was defined as layers of uniformly spaced reinforcing bars in shell elements. In these studies the surrounding structures of the non-linearly modelled reinforced concrete wall were modelled using idealised boundary conditions. Especially concrete cracking and yielding of the reinforcement was monitored during the numerical simulation. (au)

  12. Shock wave interactions with detonable clouds

    International Nuclear Information System (INIS)

    Ripley, R.C.; Josey, T.; Donahue, L.; Whitehouse, D.R.

    2004-01-01

    This paper presents results from the numerical simulation of compressible multi-species gases in an unstructured mesh CFD code called Chinook. Multiple species gases are significant to a wide range of CFD applications that involve chemical reactions, in particular detonation. The purpose of this paper is to investigate the interaction of shock waves with localized regions of reactive and non-reactive gas species. Test cases are chosen to highlight shock reflection and acceleration through combustion products resulting from the detonation of an explosive charge, and detonation wave propagation through a fuel-air cloud. Computations are performed in a 2D axi-symmetric framework. (author)

  13. Qualitative and quantitative analysis of detonation products

    International Nuclear Information System (INIS)

    Xie Yun

    2005-01-01

    Different sampling and different injection method were used during analyzing unknown detonation products in a obturator. The sample analyzed by gas chromatography and gas chromatography/mass spectrum. Qualitative analysis was used with CO, NO, C 2 H 2 , C 6 H 6 and so on, qualitative analysis was used with C 3 H 5 N, C 10 H 10 , C 8 H 8 N 2 and so on. The method used in the article is feasible. The results show that the component of detonation in the study is negative oxygen balance, there were many pollutants in the detonation products. (authors)

  14. Influence of ignition energy, ignition location, and stoichiometry on the deflagration-to-detonation distance in a Pulse Detonation Engine

    OpenAIRE

    Robinson, John P.

    2000-01-01

    The feasibility of utilizing detonations for air-breathing propulsion is the subject of a significant research effort headed by the Office of Naval Research. Pulse Detonation Engines (PDE) have a theoretically greater efficiency than current combustion cycles. However, pulse detonation technology must mature beginning with research in the fundamental process of developing a detonation wave. This thesis explores various ignition conditions which minimize the deflagration-to- detonation transit...

  15. Confined detonations with cylindrical and spherical symmetry

    International Nuclear Information System (INIS)

    Linan, A.; Lecuona, A.

    1979-01-01

    An imploding spherical or cylindrical detonation, starting in the interface of the detonantion with an external inert media, used as a reflector, creates on it a strong shock wave moving outward from the interface. An initially weak shock wave appears in the detonated media that travels toward the center, and it could reach the detonation wave, enforcing it in its process of implosion. To describe the fluid field, the Euler s equations are solved by means of expansions valid for the early stages of the process. Isentropic of the type P/pγ-K for the detonated and compressed inert media are used. For liquid or solid reflectors a more appropriate equation is used. (Author) 8 refs

  16. Aerospike Nozzle for Rotating Detonation Engine Application

    Data.gov (United States)

    National Aeronautics and Space Administration — This proposal presents a graduate MS research thesis on improving the efficiency of rotating detonation engines by using aerospike nozzle technologies. A rotating...

  17. Recent advances in numerical modeling of detonations

    Energy Technology Data Exchange (ETDEWEB)

    Mader, C.L.

    1986-12-01

    Three lectures were presented on recent advances in numerical modeling detonations entitled (1) Jet Initiation and Penetration of Explosives; (2) Explosive Desensitization by Preshocking; (3) Inert Metal-Loaded Explosives.

  18. Qualitative and Asymptotic Theory of Detonations

    KAUST Repository

    Faria, Luiz

    2014-11-09

    Shock waves in reactive media possess very rich dynamics: from formation of cells in multiple dimensions to oscillating shock fronts in one-dimension. Because of the extreme complexity of the equations of combustion theory, most of the current understanding of unstable detonation waves relies on extensive numerical simulations of the reactive compressible Euler/Navier-Stokes equations. Attempts at a simplified theory have been made in the past, most of which are very successful in describing steady detonation waves. In this work we focus on obtaining simplified theories capable of capturing not only the steady, but also the unsteady behavior of detonation waves. The first part of this thesis is focused on qualitative theories of detonation, where ad hoc models are proposed and analyzed. We show that equations as simple as a forced Burgers equation can capture most of the complex phenomena observed in detonations. In the second part of this thesis we focus on rational theories, and derive a weakly nonlinear model of multi-dimensional detonations. We also show, by analysis and numerical simulations, that the asymptotic equations provide good quantitative predictions.

  19. Detonability of H2-air-diluent mixtures

    International Nuclear Information System (INIS)

    Tieszen, S.R.; Sherman, M.P.; Benedick, W.B.; Berman, M.

    1987-06-01

    This report describes the Heated Detonation Tube (HDT). Detonation cell width and velocity results are presented for H 2 -air mixtures, undiluted and diluted with CO 2 and H 2 O for a range of H 2 concentration, initial temperature and pressure. The results show that the addition of either CO 2 or H 2 O significantly increases the detonation cell width and hence reduces the detonability of the mixture. The results also show that the detonation cell width is reduced (detonability is increased) for increased initial temperature and/or pressure

  20. Detonation nanodiamonds for doping Kevlar.

    Science.gov (United States)

    Comet, Marc; Pichot, Vincent; Siegert, Benny; Britz, Fabienne; Spitzer, Denis

    2010-07-01

    This paper reports on the first attempt to enclose diamond nanoparticles--produced by detonation--into a Kevlar matrix. A nanocomposite material (40 wt% diamond) was prepared by precipitation from an acidic solution of Kevlar containing dispersed nanodiamonds. In this material, the diamond nanoparticles (Ø = 4 nm) are entirely wrapped in a Kevlar layer about 1 nm thick. In order to understand the interactions between the nanodiamond surface and the polymer, the oxygenated surface functional groups of nanodiamond were identified and titrated by Boehm's method which revealed the exclusive presence of carboxyl groups (0.85 sites per nm2). The hydrogen interactions between these groups and the amide groups of Kevlar destroy the "rod-like" structure and the classical three-dimensional organization of this polymer. The distortion of Kevlar macromolecules allows the wrapping of nanodiamonds and leads to submicrometric assemblies, giving a cauliflower structure reminding a fractal object. Due to this structure, the macroscopic hardness of Kevlar doped by nanodiamonds (1.03 GPa) is smaller than the one of pure Kevlar (2.31 GPa). To our knowledge, this result is the first illustration of the change of the mechanical properties induced by doping the Kevlar with nanoparticles.

  1. Morphometric analysis of stab wounds by MSCT and MRI after the instillation of contrast medium.

    Science.gov (United States)

    Fais, Paolo; Cecchetto, Giovanni; Boscolo-Berto, Rafael; Toniolo, Matteo; Viel, Guido; Miotto, Diego; Montisci, Massimo; Tagliaro, Franco; Giraudo, Chiara

    2016-06-01

    To analyze the morphology and depth of stab wounds experimentally produced on human legs amputated for medical reasons using multislice computed tomography (MSCT) and magnetic resonance imaging (MRI) after the instillation of a single contrast medium solution (CMS). For morphological analysis, MSCT and MRI scans were performed before and after the instillation of CMS into the wound cavity. Depth measurements were performed on the sagittal view only after CMS instillation. Subsequently, each wound was dissected using the layer-by-layer technique and the depth was measured by a ruler. One-way between-groups pairwise analysis of variance (ANOVA) and Bland-Altman plot analysis were used for comparing radiological and anatomical measurements. Unenhanced MSCT images did not identify the wound channels, whereas unenhanced MRI evidenced the wound cavity in 50 % of cases. After the instillation of CMS, both MSCT and MRI depicted the wound channel in all the investigated stabbings, although the morphology of the cavity was irregular and did not resemble the shape of the blade. The radiological measurements of the wounds' depth, after the application of CMS, exhibited a high level of agreement (about 95 % at Bland-Altman plot analysis) with the anatomical measurements at dissection. A similar systematic underestimation, however, has been evidenced for MSCT (average 11.4 %; 95 % CI 7-17) and MRI (average 9.6 %; 95 % CI 6-13) data after the instillation of CMS with respect to wound dissection measurements. MSCT and MRI after the instillation of CMS can be used for depicting the morphometric features of stab wounds, although depth measurements are affected by a slight systematic underestimation compared to layer-by-layer dissection.

  2. Stab injury and device implantation within the brain results in inversely multiphasic neuroinflammatory and neurodegenerative responses

    Science.gov (United States)

    Potter, Kelsey A.; Buck, Amy C.; Self, Wade K.; Capadona, Jeffrey R.

    2012-08-01

    An estimated 25 million people in the US alone rely on implanted medical devices, ˜2.5 million implanted within the nervous system. Even though many devices perform adequately for years, the host response to medical devices often severely limits tissue integration and long-term performance. This host response is believed to be particularly limiting in the case of intracortical microelectrodes, where it has been shown that glial cell encapsulation and localized neuronal cell loss accompany intracortical microelectrode implantation. Since neuronal ensembles must be within ˜50 µm of the electrode to obtain neuronal spikes and local field potentials, developing a better understanding of the molecular and cellular environment at the device-tissue interface has been the subject of significant research. Unfortunately, immunohistochemical studies of scar maturation in correlation to device function have been inconclusive. Therefore, here we present a detailed quantitative study of the cellular events and the stability of the blood-brain barrier (BBB) following intracortical microelectrode implantation and cortical stab injury in a chronic survival model. We found two distinctly inverse multiphasic profiles for neuronal survival in device-implanted tissue compared to stab-injured animals. For chronically implanted animals, we observed a biphasic paradigm between blood-derived/trauma-induced and CNS-derived inflammatory markers driving neurodegeneration at the interface. In contrast, stab injured animals demonstrated a CNS-mediated neurodegenerative environment. Collectively these data provide valuable insight to the possibility of multiple roles of chronic neuroinflammatory events on BBB disruption and localized neurodegeneration, while also suggesting the importance to consider multiphasic neuroinflammatory kinetics in the design of therapeutic strategies for stabilizing neural interfaces.

  3. Delayed pneumothorax after stab wound to thorax and upper abdomen: Truth or myth?

    Science.gov (United States)

    Zehtabchi, Shahriar; Morley, Eric J; Sajed, Dana; Greenberg, Oded; Sinert, Richard

    2009-01-01

    Stab wounds to the thorax and upper abdomen have the potential to cause pneumothorax (PTX). When a CXR (CXR) obtained during initial resuscitation is negative, a second CXR (CXR-2) is commonly performed with the goal of identifying delayed PTX. To assess the diagnostic yield of the CXR-2 in identifying delayed PTX. Prospective observational study of patients (age >or=13 years) with stab wounds to the thorax (chest/back) and upper abdomen with suspected PTX, in a level 1 trauma centre. Patients were included if they had a negative initial CXR followed by a repeat CXR 3-6h after the initial one. patients who died, were transferred out of the ED, or received chest tubes before the second CXR. The outcome of interest was delayed PTX. All CXR were read by an attending radiologist. To test the inter-observer agreement, another blinded radiologist reviewed 20% of CXR. Continuous data is presented as mean+/-standard deviation and categorical data as percentages with 95% confidence interval (CI). Kappa statistics were used to measure the inter-observer agreement between radiologists. Between January 2003 and December 2006 a total of 185 patients qualified for the enrollment (mean age: 28+/-10 years, age range: 13-65, 94% male). Only 2 patients (1.1%, 95% CI, 0.4- 4.1%) had PTX on the CXR-2. Both patients received chest tubes. The inter-observer agreement for radiology reports was high (kappa: 0.79). Occurrence of delayed PTX in patients with stab wounds to the thorax and upper abdomen and negative triage CXR is rare.

  4. Early MRI findings in stab wound of the cervical spine: two case reports

    Energy Technology Data Exchange (ETDEWEB)

    Alkan, A.; Baysal, T.; Sarac, K.; Sigirci, A.; Kutlu, R. [Inonu Universitesi Turgut Ozal Tip Merkezi, Radyoloji Anabilim Dali, Malatya (Turkey)

    2002-01-01

    MR imaging was found to be the most sensitive modality for the detection of spinal cord abnormalities in the acutely injured spine. Although it is reported that traumatic pneumomyelogram indicates a base-of-skull or middle cranial fossa fracture and is almost certainly associated with intracranial subarachnoid air, early MR imaging may demonstrate subarachnoid air in penetrating trauma of the spinal cord without head injury. We report two cervical-spine stab-wound cases, one of which had subarachnoid air on early MR findings. (orig.)

  5. Modeling Hemispheric Detonation Experiments in 2-Dimensions

    Energy Technology Data Exchange (ETDEWEB)

    Howard, W M; Fried, L E; Vitello, P A; Druce, R L; Phillips, D; Lee, R; Mudge, S; Roeske, F

    2006-06-22

    Experiments have been performed with LX-17 (92.5% TATB and 7.5% Kel-F 800 binder) to study scaling of detonation waves using a dimensional scaling in a hemispherical divergent geometry. We model these experiments using an arbitrary Lagrange-Eulerian (ALE3D) hydrodynamics code, with reactive flow models based on the thermo-chemical code, Cheetah. The thermo-chemical code Cheetah provides a pressure-dependent kinetic rate law, along with an equation of state based on exponential-6 fluid potentials for individual detonation product species, calibrated to high pressures ({approx} few Mbars) and high temperatures (20000K). The parameters for these potentials are fit to a wide variety of experimental data, including shock, compression and sound speed data. For the un-reacted high explosive equation of state we use a modified Murnaghan form. We model the detonator (including the flyer plate) and initiation system in detail. The detonator is composed of LX-16, for which we use a program burn model. Steinberg-Guinan models5 are used for the metal components of the detonator. The booster and high explosive are LX-10 and LX-17, respectively. For both the LX-10 and LX-17, we use a pressure dependent rate law, coupled with a chemical equilibrium equation of state based on Cheetah. For LX-17, the kinetic model includes carbon clustering on the nanometer size scale.

  6. Detonation measurements on damaged LX-04

    Energy Technology Data Exchange (ETDEWEB)

    Hsu, Peter; Souers, P.C.; Chidester, Steve; Alvarez, John; De Haven, Martin; Garza, Raul; Harwood, Pat; Maienschein, Jon [Lawrence Livermore National Laboratory, Livermore, CA 94551 (United States)

    2007-12-15

    We have applied thermal insults on LX-04 at 185 C and found that the material expanded significantly, resulting in a bulk density reduction of 12%. Subsequent detonation experiments (three cylinder tests) were conducted on the thermally damaged LX-04 samples and pristine low-density LX-04 samples and the results showed that the fractions reacted were close to 1.0. The thermally damaged LX-04 and pristine low-density LX-04 showed detonation velocities of 7.7-7.8 mm {mu}s{sup -1}, significantly lower than that (8.5 mm {mu}s{sup -1}) of pristine high-density LX-04. Detonation energy densities for the damaged LX-04, low-density pristine LX-04, and hot cylinder shot of LX-04 were 6.48, 6.62, and 6.58 kJ cm{sup -3}, respectively, lower than the detonation energy density of 8.11 kJ cm{sup -3} for the high density pristine LX-04. The break-out curves for the detonation fronts showed that the damaged LX-04 had longer edge lags than the high density pristine LX-04, indicating that the damaged explosive is less ideal. (Abstract Copyright [2007], Wiley Periodicals, Inc.)

  7. Benign Liver Tumors

    Science.gov (United States)

    ... Legacy Society Make Gifts of Stock Donate Your Car Personal Fundraising Partnership & Support Share Your Story Spread the Word Give While You Shop Contact Us Donate Now Benign Liver Tumors Back ...

  8. Benign positional vertigo - aftercare

    Science.gov (United States)

    Vertigo - positional - aftercare; Benign paroxysmal positional vertigo - aftercare; BPPV - aftercare; Dizziness - positional vertigo ... Your health care provider may have treated your vertigo with the Epley maneuver . These are head movements ...

  9. Benign Essential Blepharospasm

    Science.gov (United States)

    ... the same for many years; and, in rare cases, improve spontaneously. Clinical Trials Throughout the U.S. and Worldwide NINDS Clinical Trials Related ... Definition Benign essential blepharospasm (BEB) is a progressive neurological ...

  10. Detonation-synthesis nanodiamonds: synthesis, structure, properties and applications

    Energy Technology Data Exchange (ETDEWEB)

    Dolmatov, Valerii Yu [Federal State Unitary Enterprise Special Design-Technology Bureau (FSUE SDTB) ' ' Tekhnolog' ' at the St Petersburg State Institute of Technology (Technical University) (Russian Federation)

    2007-04-30

    The review outlines the theoretical foundations and industrial implementations of modern detonation synthesis of nanodiamonds and chemical purification of the nanodiamonds thus obtained. The structure, key properties and promising fields of application of detonation-synthesis nanodiamonds are considered.

  11. Detonation-synthesis nanodiamonds: synthesis, structure, properties and applications

    International Nuclear Information System (INIS)

    Dolmatov, Valerii Yu

    2007-01-01

    The review outlines the theoretical foundations and industrial implementations of modern detonation synthesis of nanodiamonds and chemical purification of the nanodiamonds thus obtained. The structure, key properties and promising fields of application of detonation-synthesis nanodiamonds are considered.

  12. Multistage reaction pathways in detonating high explosives

    International Nuclear Information System (INIS)

    Li, Ying; Kalia, Rajiv K.; Nakano, Aiichiro; Nomura, Ken-ichi; Vashishta, Priya

    2014-01-01

    Atomistic mechanisms underlying the reaction time and intermediate reaction products of detonating high explosives far from equilibrium have been elusive. This is because detonation is one of the hardest multiscale physics problems, in which diverse length and time scales play important roles. Here, large spatiotemporal-scale reactive molecular dynamics simulations validated by quantum molecular dynamics simulations reveal a two-stage reaction mechanism during the detonation of cyclotrimethylenetrinitramine crystal. Rapid production of N 2 and H 2 O within ∼10 ps is followed by delayed production of CO molecules beyond ns. We found that further decomposition towards the final products is inhibited by the formation of large metastable carbon- and oxygen-rich clusters with fractal geometry. In addition, we found distinct unimolecular and intermolecular reaction pathways, respectively, for the rapid N 2 and H 2 O productions

  13. Multistage reaction pathways in detonating high explosives

    Energy Technology Data Exchange (ETDEWEB)

    Li, Ying [Collaboratory for Advanced Computing and Simulations, Department of Physics and Astronomy, Department of Computer Science, and Department of Chemical Engineering and Materials Science, University of Southern California, Los Angeles, California 90089-0242 (United States); Argonne Leadership Computing Facility, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Kalia, Rajiv K.; Nakano, Aiichiro; Nomura, Ken-ichi; Vashishta, Priya [Collaboratory for Advanced Computing and Simulations, Department of Physics and Astronomy, Department of Computer Science, and Department of Chemical Engineering and Materials Science, University of Southern California, Los Angeles, California 90089-0242 (United States)

    2014-11-17

    Atomistic mechanisms underlying the reaction time and intermediate reaction products of detonating high explosives far from equilibrium have been elusive. This is because detonation is one of the hardest multiscale physics problems, in which diverse length and time scales play important roles. Here, large spatiotemporal-scale reactive molecular dynamics simulations validated by quantum molecular dynamics simulations reveal a two-stage reaction mechanism during the detonation of cyclotrimethylenetrinitramine crystal. Rapid production of N{sub 2} and H{sub 2}O within ∼10 ps is followed by delayed production of CO molecules beyond ns. We found that further decomposition towards the final products is inhibited by the formation of large metastable carbon- and oxygen-rich clusters with fractal geometry. In addition, we found distinct unimolecular and intermolecular reaction pathways, respectively, for the rapid N{sub 2} and H{sub 2}O productions.

  14. Multiple stab wounds: understanding the manner of death through the psychological autopsy.

    Science.gov (United States)

    Di Vella, G; Grattagliano, I; Curti, S; Catanesi, R; Sullivan, M K; Tattoli, L

    2017-01-01

    A 48-year-old physical therapist with no history of psychiatric disorders or suicidal tendencies was found dead by his relatives inside his apartment. Multiple stab wounds were present on the chest and the abdomen. Several more superficial cuts were also seen on the neck and the left wrist. At the death scene, there was a large pool of blood in the room, with secondary droplets and stains; a kitchen knife was found beside the body, and a suicide note on a table. Especially the number of wounds raised strong suspicion of a homicide in the first instance but some circumstances (the farewell letter, the absence of clothing injuries, no signs of third-party involvement) and autopsy findings (absence of defense or blunt injuries, the localization of the wounds, the presence of hesitation marks) pointed toward a suicide etiology. Because of the many stab injuries and the lack of a psychiatric history, further forensic investigations were required including a so-called psychological autopsy. This case report highlights that only a comprehensive interpretation of all the elements (circumstances, the scene of death, autopsy findings, and psychological autopsy) can lead to the correct solution of atypical cases of suicide.

  15. 30 CFR 75.1311 - Transporting explosives and detonators.

    Science.gov (United States)

    2010-07-01

    ... noncombustible materials. (c) When explosives and detonators are transported on conveyor belts— (1) Containers of... explosives or detonators, a person shall be at each transfer point between belts and at the unloading location; and (4) Conveyor belts shall be stopped before explosives or detonators are loaded or unloaded...

  16. 30 CFR 56.6402 - Deenergized circuits near detonators.

    Science.gov (United States)

    2010-07-01

    ... Electric Blasting § 56.6402 Deenergized circuits near detonators. Electrical distribution circuits within 50 feet of electric detonators at the blast site shall be deenergized. Such circuits need not be deenergized between 25 to 50 feet of the electric detonators if stray current tests, conducted as frequently...

  17. 30 CFR 57.6402 - Deenergized circuits near detonators.

    Science.gov (United States)

    2010-07-01

    ... Electric Blasting-Surface and Underground § 57.6402 Deenergized circuits near detonators. Electrical distribution circuits within 50 feet of electric detonators at the blast site shall be deenergized. Such circuits need not be deenergized between 25 to 50 feet of the electric detonators if stray current tests...

  18. 30 CFR 57.6400 - Compatibility of electric detonators.

    Science.gov (United States)

    2010-07-01

    ... Electric Blasting-Surface and Underground § 57.6400 Compatibility of electric detonators. All electric detonators to be fired in a round shall be from the same manufacturer and shall have similar electrical... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Compatibility of electric detonators. 57.6400...

  19. 30 CFR 56.6400 - Compatibility of electric detonators.

    Science.gov (United States)

    2010-07-01

    ... Electric Blasting § 56.6400 Compatibility of electric detonators. All electric detonators to be fired in a round shall be from the same manufacturer and shall have similar electrical firing characteristics. ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Compatibility of electric detonators. 56.6400...

  20. Investigation of hydrogen-deflagration/-detonation

    International Nuclear Information System (INIS)

    Breitung, W.; Redlinger, R.; Werle, H.; Moeschke, M.

    1992-01-01

    The static and dynamic loads of a PWR-containment from hydrogen combustion are investigated theoretically and experimentally. The primary goal is the determination of realistic, not too conservative, upper bounds. The load data are needed to define design requirements for a core-melt resistant containment structure. The following work was performed in 1991: balloon tests; design of a medium scale detonation tube; development of a 1D detonation code; analytical study with SNL/Albuquerque, USA and documentation and presentation of results. (orig./DG)

  1. Exergetic efficiency analysis of hydrogen–air detonation in pulse detonation combustor using computational fluid dynamics

    Directory of Open Access Journals (Sweden)

    Pinku Debnath

    2017-03-01

    Full Text Available Exergy losses during the combustion process, heat transfer, and fuel utilization play a vital role in the analysis of the exergetic efficiency of combustion process. Detonation is thermodynamically more efficient than deflagration mode of combustion. Detonation combustion technology inside the pulse detonation engine using hydrogen as a fuel is energetic propulsion system for next generation. In this study, the main objective of this work is to quantify the exergetic efficiency of hydrogen–air combustion for deflagration and detonation combustion process. Further detonation parameters are calculated using 0.25, 0.35, and 0.55 of H2 mass concentrations in the combustion process. The simulations have been performed for converging the solution using commercial computational fluid dynamics package Ansys Fluent solver. The details of combustion physics in chemical reacting flows of hydrogen–air mixture in two control volumes were simulated using species transport model with eddy dissipation turbulence chemistry interaction. From these simulations it was observed that exergy loss in the deflagration combustion process is higher in comparison to the detonation combustion process. The major observation was that pilot fuel economy for the two combustion processes and augmentation of exergetic efficiencies are better in the detonation combustion process. The maximum exergetic efficiency of 55.12%, 53.19%, and 23.43% from deflagration combustion process and from detonation combustion process, 67.55%, 57.49%, and 24.89%, are obtained from aforesaid H2 mass fraction. It was also found that for lesser fuel mass fraction higher exergetic efficiency was observed.

  2. Detonation characteristics of ammonium nitrate products

    NARCIS (Netherlands)

    Kersten, R.J.A.; Hengel, E.I.V. van den; Steen, A.C. van der

    2006-01-01

    The detonation properties of ammonium nitrate (AN) products depend on many factors and are therefore, despite the large amount of information on this topic, difficult to assess. In order to further improve the understanding of the safety properties of AN, the European Fertilizer Manufacturers

  3. Hydrogen detonation and detonation transition data from the High-Temperature Combustion Facility

    International Nuclear Information System (INIS)

    Ciccarelli, G.; Boccio, J.L.; Ginsberg, T.; Finfrock, C.; Gerlach, L.; Malliakos, A.

    1995-01-01

    The BNL High-Temperature Combustion Facility (HTCF) is an experimental research tool capable of investigating the effects of initial thermodynamic state on the high-speed combustion characteristic of reactive gas mixtures. The overall experimental program has been designed to provide data to help characterize the influence of elevated gas-mixture temperature (and pressure) on the inherent sensitivity of hydrogen-air-steam mixtures to undergo detonation, on the potential for flames accelerating in these mixtures to transition into detonations, on the effects of gas venting on the flame-accelerating process, on the phenomena of initiation of detonations in these mixtures by jets of hot reactant product,s and on the capability of detonations within a confined space to transmit into another, larger confined space. This paper presents results obtained from the completion of two of the overall test series that was designed to characterize high-speed combustion phenomena in initially high-temperature gas mixtures. These two test series are the intrinsic detonability test series and the deflagration-to-detonation (DDT) test series. A brief description of the facility is provided below

  4. Hydrogen detonation and detonation transition data from the High-Temperature Combustion Facility

    International Nuclear Information System (INIS)

    Ciccarelli, G.; Boccio, J.L.; Ginsberg, T.; Finfrock, C.

    1996-01-01

    The BNL High-Temperature Combustion Facility (HTCF) is an experimental research tool capable of investigating the effects of initial thermodynamic state on the high-speed combustion characteristic of reactive gas mixtures. The overall experimental program has been designed to provide data to help characterize the influence of elevated gas-mixture temperature (and pressure) on the inherent sensitivity of hydrogen-air-steam mixtures to undergo detonation, on the potential for flames accelerating in these mixtures to transition into detonations, on the effects of gas venting on the flame-accelerating process, on the phenomena of initiation of detonations in these mixtures by jets of hot reactant products, and on the capability of detonations within a confined space to transmit into another, larger confined space. This paper presents results obtained from the completion of two of the overall test series that was designed to characterize high-speed combustion phenomena in initially high-temperature gas mixtures. These two test series are the intrinsic detonability test series and the deflagration-to-detonation (DDT) test series. A brief description of the facility is provided below

  5. [Gunshot and stab wounds in Germany--epidemiology and outcome: analysis from the TraumaRegister DGU®].

    Science.gov (United States)

    Bieler, D; Franke, A F; Hentsch, S; Paffrath, T; Willms, A; Lefering, R; Kollig, E W

    2014-11-01

    The management of gunshot wounds is a rare challenge for trauma surgeons in Germany and Central Europe as a result of the low incidence of this type of trauma. Penetrating injuries occur with an incidence of 5% in Germany. They are caused by gunshots or more commonly by knives or other objects, for example during accidents. Since even the number of patients who are treated at level 1 trauma centres is limited by the low incidence, the objective of this study was to assess the epidemiology and outcome of gunshot and stab wounds in Germany. Since 2009, the trauma registry of the German Trauma Society (TraumaRegister DGU®) has been used to assess not only whether a trauma was penetrating but also whether it was caused by a gunshot or a stabbing. On the basis of this registry, we identified relevant cases and defined the observation period. Data were taken from the standard documentation forms that participating German hospitals completed between 2009 and 2011. We did not specify exclusion criteria in order to obtain as comprehensive a picture as possible of the trauma entities investigated in this study. As a result of the high incidence of gunshot wounds to the head and the implications of this type of injury for the entire group, a subgroup of patients without head injuries was analysed. From 2009 to 2011, there were 305 patients with gunshot wounds and 871 patients with stab wounds. The high proportion of suicide-related gunshot wounds to the head resulted in a cumulative mortality rate of 39.7%. Stab wounds were associated with a lower mortality rate (6.2%). Every fourth patient with a gunshot or stab wound presented with haemorrhagic shock, which was considerably more frequently seen during the prehospital phase than during the inhospital phase of patient management. Of the patients with gunshot wounds, 26.9% required transfusions. This percentage was three times higher than that for patients with blunt trauma. In Germany, gunshot and stab wounds have a low

  6. Differences between postmortem computed tomography and conventional autopsy in a stabbing murder case

    Directory of Open Access Journals (Sweden)

    Talita Zerbini

    2014-12-01

    Full Text Available Objective: The aim of the present work is to analyze the differences and similarities between the elements of a conventional autopsy and images obtained from postmortem computed tomography in a case of a homicide stab wound. Method: Comparison between the findings of different methods: autopsy and postmortem computed tomography. Results: In some aspects, autopsy is still superior to imaging, especially in relation to external examination and the description of lesion vitality. However, the findings of gas embolism, pneumothorax and pulmonary emphysema and the relationship between the internal path of the instrument of aggression and the entry wound are better demonstrated by postmortem computed tomography. Conclusions: Although multislice computed tomography has greater accuracy than autopsy, we believe that the conventional autopsy method is fundamental for providing evidence in criminal investigations.

  7. An unusual case of orbito-frontal rod fence stab injury with a good outcome.

    Science.gov (United States)

    Miscusi, Massimo; Arangio, Paolo; De Martino, Luca; De-Giorgio, Fabio; Cascone, Piero; Raco, Antonino

    2013-08-13

    High-energy non-missile penetrating injuries (stab injuries) account for a small percentage of penetrating head injuries and they present a series of special features. A 35-year-old man suffered orbito-frontal? and trans-cranial injuries after falling five meters from a terrace onto a rod iron fence. The removal of the metal rod was performed outside the operating room. The orbital roof was exposed and repaired through a bifrontal craniotomy and the frontal sinuses were cranialised. The orbital floor and zygoma were plated with micro-screws. The patient recovered without significant complications, apart from a slight paresis of the right superior rectus; the ocular globe remained intact.The positive outcome obtained in this very challenging case is attributable to the competency of the Neurotrauma Unit and to the use of a synergistic approach which involved the contribution of neurosurgeons, maxillo-facial surgeons, radiologists and anaesthesiologists.

  8. Benign bone tumors

    International Nuclear Information System (INIS)

    Gilday, D.L.; Ash, J.M.

    1976-01-01

    There is little information in the literature concerning the role of bone scanning in benign bone neoplasms except for sporadic reports. Since the advent of /sup 99m/Tc-polyphosphate, bone imaging has proven feasible and useful in locating the cause of bone pain, such as in osteoid osteomas, which are not always radiologically apparent, and in evaluating whether or not a radiologic lesion is indeed benign and solitary. Blood-pool images are particularly important in neoplastic disease, since the absence of hyperemia in the immediate postinjection period favors the diagnosis of a benign neoplasm, as does low-grade uptake on the delayed study. The scan, including pinhole magnification images, is especially valuable in diagnosing lesions in the spine and pelvis, which are poorly seen radiologically. We have studied various types of benign bone tumors, including simple and aneurysmal bone cysts, fibrous cortical defects, and nonossifying fibromas, all of which had minimal or no increased uptake of the radiopharmaceutical, unless traumatized. Although osteochondromas and enchondromas showed varied accumulation of activity, the scan was useful in differentiating these from sarcomatous lesions. All osteoid osteomas demonstrated marked activity, and could be accurately located preoperatively, as could the extent of fibrous dysplasia. The bone scan in the reticuloses also showed abnormal accumulation of activity, and aided in arriving at the prognosis and treatment of histiocytic bone lesions

  9. Postmortem ventilation in cases of penetrating gunshot and stab wounds to the chest.

    Science.gov (United States)

    Germerott, Tanja; Preiss, Ulrich S; Ross, Steffen G; Thali, Michael J; Flach, Patricia M

    2013-11-01

    We sought to determine the effect of postmortem ventilation in combination with a suction pump in cases showing penetrating trauma to the chest with haemo- and/or pneumothorax, for better evaluation of the lungs in postmortem computed tomography (PMCT). The study included 6 subjects (1 female, 5 male; age 32-67years) with a penetrating gunshot or stab wound to the chest and consecutive pneumo- and/or haemothorax. The pneumo- and haemothorax were evacuated by a suction pump, and postmortem ventilation was applied using a home care ventilator. PMCT images with and without postmortem ventilation were compared, as well as the autopsy results. In three cases haemo- and pneumothorax was clearly reduced. Postmortem ventilation led to distinct re-expansion of the lungs in two cases, and to re-expansion of single lung lobes in two cases with shotgun injuries. No visible effect was seen in the remaining two cases, because of extensive destruction of lung tissue and blood aspiration. In two cases the injuries sustained in the individual lung lobes were successfully located during postmortem ventilation. The bullet channel was apparent in one case; in another case, injury of the pericardium became visible by generating pneumopericardium. The present method is capable of improving evaluation of the postmortem lung in the presence of single stab or gunshot wounds and if there is no severe destruction of the respiratory system and aspiration. Forensic autopsy should still be considered as the gold standard, although in some cases the present method might be helpful, especially where no autopsy is required. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  10. Benign gastric filling defect

    International Nuclear Information System (INIS)

    Oh, K. K.; Lee, Y. H.; Cho, O. K.; Park, C. Y.

    1979-01-01

    The gastric lesion is a common source of complaints to Orientals, however, evaluation of gastric symptoms and laboratory examination offer little specific aid in the diagnosis of gastric diseases. Thus roentgenography of gastrointestinal tract is one of the most reliable method for detail diagnosis. On double contract study of stomach, gastric filling defect is mostly caused by malignant gastric cancer, however, other benign lesions can cause similar pictures which can be successfully treated by surgery. 66 cases of benign causes of gastric filling defect were analyzed at this point of view, which was verified pathologically by endoscope or surgery during recent 7 years in Yensei University College of Medicine, Severance Hospital. The characteristic radiological picture of each disease was discussed for precise radiologic diagnosis. 1. Of total 66 cases, there were 52 cases of benign gastric tumor 10 cases of gastric varices, 5 cases of gastric bezoar, 5 cases of corrosive gastritis, 3 cases of granulomatous disease and one case of gastric hematoma. 2. The most frequent causes of benign tumors were adenomatous polyp (35/42) and the next was leiomyoma (4/42). Others were one of case of carcinoid, neurofibroma and cyst. 3. Characteristic of benign adenomatous polyp were relatively small in size, smooth surface and were observed that large size, benign polyp was frequently type IV lesion with a stalk. 4. Submucosal tumors such as leiomyoma needed differential diagnosis with polypoid malignant cancer. However, the characteristic points of differentiation was well circumscribed smooth margined filling defect without definite mucosal destruction on surface. 5. Gastric varices showed multiple lobulated filling defected especially on gastric fundus that changed its size and shape by respiration and posture of patients. Same varices lesions on esophagus and history of liver disease were helpful for easier diagnosis. 6. Gastric bezoar showed well defined movable mass

  11. Benign gastric filling defect

    Energy Technology Data Exchange (ETDEWEB)

    Oh, K. K.; Lee, Y. H.; Cho, O. K.; Park, C. Y. [Yonsei University College of Medicine, Seoul (Korea, Republic of)

    1979-06-15

    The gastric lesion is a common source of complaints to Orientals, however, evaluation of gastric symptoms and laboratory examination offer little specific aid in the diagnosis of gastric diseases. Thus roentgenography of gastrointestinal tract is one of the most reliable method for detail diagnosis. On double contract study of stomach, gastric filling defect is mostly caused by malignant gastric cancer, however, other benign lesions can cause similar pictures which can be successfully treated by surgery. 66 cases of benign causes of gastric filling defect were analyzed at this point of view, which was verified pathologically by endoscope or surgery during recent 7 years in Yensei University College of Medicine, Severance Hospital. The characteristic radiological picture of each disease was discussed for precise radiologic diagnosis. 1. Of total 66 cases, there were 52 cases of benign gastric tumor 10 cases of gastric varices, 5 cases of gastric bezoar, 5 cases of corrosive gastritis, 3 cases of granulomatous disease and one case of gastric hematoma. 2. The most frequent causes of benign tumors were adenomatous polyp (35/42) and the next was leiomyoma (4/42). Others were one of case of carcinoid, neurofibroma and cyst. 3. Characteristic of benign adenomatous polyp were relatively small in size, smooth surface and were observed that large size, benign polyp was frequently type IV lesion with a stalk. 4. Submucosal tumors such as leiomyoma needed differential diagnosis with polypoid malignant cancer. However, the characteristic points of differentiation was well circumscribed smooth margined filling defect without definite mucosal destruction on surface. 5. Gastric varices showed multiple lobulated filling defected especially on gastric fundus that changed its size and shape by respiration and posture of patients. Same varices lesions on esophagus and history of liver disease were helpful for easier diagnosis. 6. Gastric bezoar showed well defined movable mass

  12. Benign gastric filling defect

    Energy Technology Data Exchange (ETDEWEB)

    Oh, K K; Lee, Y H; Cho, O K; Park, C Y [Yonsei University College of Medicine, Seoul (Korea, Republic of)

    1979-06-15

    The gastric lesion is a common source of complaints to Orientals, however, evaluation of gastric symptoms and laboratory examination offer little specific aid in the diagnosis of gastric diseases. Thus roentgenography of gastrointestinal tract is one of the most reliable method for detail diagnosis. On double contract study of stomach, gastric filling defect is mostly caused by malignant gastric cancer, however, other benign lesions can cause similar pictures which can be successfully treated by surgery. 66 cases of benign causes of gastric filling defect were analyzed at this point of view, which was verified pathologically by endoscope or surgery during recent 7 years in Yensei University College of Medicine, Severance Hospital. The characteristic radiological picture of each disease was discussed for precise radiologic diagnosis. 1. Of total 66 cases, there were 52 cases of benign gastric tumor 10 cases of gastric varices, 5 cases of gastric bezoar, 5 cases of corrosive gastritis, 3 cases of granulomatous disease and one case of gastric hematoma. 2. The most frequent causes of benign tumors were adenomatous polyp (35/42) and the next was leiomyoma (4/42). Others were one of case of carcinoid, neurofibroma and cyst. 3. Characteristic of benign adenomatous polyp were relatively small in size, smooth surface and were observed that large size, benign polyp was frequently type IV lesion with a stalk. 4. Submucosal tumors such as leiomyoma needed differential diagnosis with polypoid malignant cancer. However, the characteristic points of differentiation was well circumscribed smooth margined filling defect without definite mucosal destruction on surface. 5. Gastric varices showed multiple lobulated filling defected especially on gastric fundus that changed its size and shape by respiration and posture of patients. Same varices lesions on esophagus and history of liver disease were helpful for easier diagnosis. 6. Gastric bezoar showed well defined movable mass

  13. Reduced detonation kinetics and detonation structure in one- and multi-fuel gaseous mixtures

    Science.gov (United States)

    Fomin, P. A.; Trotsyuk, A. V.; Vasil'ev, A. A.

    2017-10-01

    Two-step approximate models of chemical kinetics of detonation combustion of (i) one-fuel (CH4/air) and (ii) multi-fuel gaseous mixtures (CH4/H2/air and CH4/CO/air) are developed for the first time. The models for multi-fuel mixtures are proposed for the first time. Owing to the simplicity and high accuracy, the models can be used in multi-dimensional numerical calculations of detonation waves in corresponding gaseous mixtures. The models are in consistent with the second law of thermodynamics and Le Chatelier’s principle. Constants of the models have a clear physical meaning. Advantages of the kinetic model for detonation combustion of methane has been demonstrated via numerical calculations of a two-dimensional structure of the detonation wave in a stoichiometric and fuel-rich methane-air mixtures and stoichiometric methane-oxygen mixture. The dominant size of the detonation cell, determines in calculations, is in good agreement with all known experimental data.

  14. A transient model to the thermal detonation

    International Nuclear Information System (INIS)

    Karachalios, K.

    1987-04-01

    The model calculates the escalation dynamics and the long time behavior of thermal detonation waves depending on the initial and boundary conditions (data of the premixture, ignition at a solid wall or at an open end, etc.). Especially, for a given mixture and a certain fragmentation behavior more than one stable steady-state cases resulted, depending on the applied ignition energy. Investigations showed a very good consistency between the transient model and a steady-state model which is based on the same physical description and includes an additional stability criterion. Also the influence of effects such as e.g. non-homogeneous coolant heating, spherical instead of plane wave propagation and inhomogeneities of the premixture on the development of the wave were investigated. Comparison calculations with large scale experiments showed that they can be well explained by means of the thermal detonation theory, especially considering the transient phase of the wave development. (orig./HP) [de

  15. Precursors in detonations in porous explosives

    International Nuclear Information System (INIS)

    Spaulding, R.L. Jr.

    1981-01-01

    Photographs of detonation waves in low-density HMX and PETN, made with an image-intensifier camera, show a brilliant band of light in front of the pressure jump. The radiation temperature is estimated to be 12,000 to 14,000 0 K. The spectrum of this light is continuous. A quartz gauge shows a gradual buildup of pressure from the material producing the light. The material has little effect on the propagation of detonation. Further observations, using pellets of plastic-bonded HMX and single crystals of PETN, show that the material thrown off the free surface is transparent, with a leading edge moving at approximately 20 mm/μs. Collision of this material with polymethyl methacrylate (PMMA) produces a brilliant light with a spectrum that is initially a narrow H/sub α/ line. Quartz gauges measure the rate of pessure buildup of this material

  16. [Large benign prostatic hiperplasia].

    Science.gov (United States)

    Soria-Fernández, Guillermo René; Jungfermann-Guzman, José René; Lomelín-Ramos, José Pedro; Jaspersen-Gastelum, Jorge; Rosas-Nava, Jesús Emmanuel

    2012-01-01

    the term prostatic hyperplasia is most frequently used to describe the benign prostatic growth, this being a widely prevalent disorder associated with age that affects most men as they age. The association between prostate growth and urinary obstruction in older adults is well documented. large benign prostatic hyperplasia is rare and few cases have been published and should be taken into account during the study of tumors of the pelvic cavity. we report the case of an 81-year-old who had significant symptoms relating to storage and bladder emptying, with no significant elevation of prostate specific antigen. this is a rare condition but it is still important to diagnose and treat as it may be related to severe obstructive uropathy and chronic renal failure. In our institution, cases of large prostatic hyperplasia that are solved by suprapubic adenomectomy are less than 3%.

  17. Benign breast myoepithelioma

    Directory of Open Access Journals (Sweden)

    L Khan

    2013-01-01

    Full Text Available Myoepithelioma of the breast is very rare. Breast myoepithelioma can develop in women from their early 20s right up to their 80s, but it is most common in women over 50. We report a case of 20-year-old female, who presented with a well-defined breast lump of 3 × 3 cm in size. Fine needle aspiration was performed. The cytological findings revealed good cellularity comprising monomorphic loosely cohesive sheets of plasmacytoid, round to polygonal cells with round to ovoid eccentrically placed nuclei, finely dispersed chromatin, and moderate amount of cytoplasm. On the basis of cytological findings, a diagnosis of benign myoepithelioma (plasmacytoid type was made which was confirmed on histopathologic examination. The breast is a very rare localization for this type of tumor. The benign character of the disease in conjunction with its slow progression could delay its detection and diagnosis. A detailed pathology examination is a prerequisite for avoidance of misleading diagnosis.

  18. Effects of Injection Scheme on Rotating Detonation Engine Operation

    Science.gov (United States)

    Chacon, Fabian; Duvall, James; Gamba, Mirko

    2017-11-01

    In this work, we experimentally investigate the operation and performance characteristics of a rotating detonation engine (RDE) operated with different fuel injection schemes and operating conditions. In particular, we investigate the detonation and operation characteristics produced with an axial flow injector configuration and semi-impinging injector configurations. These are compared to the characteristics produced with a canonical radial injection system (AFRL injector). Each type produces a different flowfield and mixture distribution, leading to a different detonation initiation, injector dynamic response, and combustor pressure rise. By using a combination of diagnostics, we quantify the pressure loses and gains in the system, the ability to maintain detonation over a range of operating points, and the coupling between the detonation and the air/fuel feed lines. We particularly focus on how this coupling affects both the stability and the performance of the detonation wave. This work is supported by the DOE/UTSR program under project DE-FE0025315.

  19. Radio controlled detonators and sequential real time blast applications

    Energy Technology Data Exchange (ETDEWEB)

    Bernard, T.; Laboz, J.M. [Delta Caps International, Nice (France)

    1995-12-31

    Among the numerous technical evolutions in the blasting environment the authors are going to describe below the concept of electronic detonator sequenced by radio waves, and also its numerous applications. Three major technologies are used in the initiation environment: fused-initiated detonators; electric detonators; and non-electric detonators. The last two technologies were made available under multiple variants. Two major innovations are going to substantially change the way traditional detonators operate: pyrotechnic delays are replaced by electronic delays (greater accuracy); and triggering orders, passing through a cable, is now replaced by radio-waves transmission (possibility to do real time delay pattern). Such a new product provided all the features offered by current detonators, but also allows mastering specific cases that were difficult to control with the current technology, such as: vibration control; underground blast; and building demolition.

  20. Insensitive detonator apparatus for initiating large failure diameter explosives

    Science.gov (United States)

    Perry, III, William Leroy

    2015-07-28

    A munition according to a preferred embodiment can include a detonator system having a detonator that is selectively coupled to a microwave source that functions to selectively prime, activate, initiate, and/or sensitize an insensitive explosive material for detonation. The preferred detonator can include an explosive cavity having a barrier within which an insensitive explosive material is disposed and a waveguide coupled to the explosive cavity. The preferred system can further include a microwave source coupled to the waveguide such that microwaves enter the explosive cavity and impinge on the insensitive explosive material to sensitize the explosive material for detonation. In use the preferred embodiments permit the deployment and use of munitions that are maintained in an insensitive state until the actual time of use, thereby substantially preventing unauthorized or unintended detonation thereof.

  1. Detonation of Meta-stable Clusters

    Energy Technology Data Exchange (ETDEWEB)

    Kuhl, Allen; Kuhl, Allen L.; Fried, Laurence E.; Howard, W. Michael; Seizew, Michael R.; Bell, John B.; Beckner, Vincent; Grcar, Joseph F.

    2008-05-31

    We consider the energy accumulation in meta-stable clusters. This energy can be much larger than the typical chemical bond energy (~;;1 ev/atom). For example, polymeric nitrogen can accumulate 4 ev/atom in the N8 (fcc) structure, while helium can accumulate 9 ev/atom in the excited triplet state He2* . They release their energy by cluster fission: N8 -> 4N2 and He2* -> 2He. We study the locus of states in thermodynamic state space for the detonation of such meta-stable clusters. In particular, the equilibrium isentrope, starting at the Chapman-Jouguet state, and expanding down to 1 atmosphere was calculated with the Cheetah code. Large detonation pressures (3 and 16 Mbar), temperatures (12 and 34 kilo-K) and velocities (20 and 43 km/s) are a consequence of the large heats of detonation (6.6 and 50 kilo-cal/g) for nitrogen and helium clusters respectively. If such meta-stable clusters could be synthesized, they offer the potential for large increases in the energy density of materials.

  2. Benign pneumatosis in children

    International Nuclear Information System (INIS)

    Fenton, L.Z.; Buonomo, C.

    2000-01-01

    Background. In pediatrics, pneumatosis intestinalis (PI) is usually due to necrotizing enterocolitis in premature newborns. Beyond infancy, PI is uncommon. ''Benign pneumatosis'' is PI in patients with few or no symptoms that resolves with conservative management. Objective. Our goal was to better characterize benign PI in children. Our investigation focused on identifying underlying risk factors, symptoms at time of diagnosis, management and outcome. Materials and methods. Available medical records and radiographs of children with pneumatosis intestinalis from 1990 to 1998 were reviewed for underlying conditions, symptoms at time of radiographs, management and outcome. Results. Thirty-seven children (mean age 4 years) were included. Thirty-two children had identifiable risk factors. Twenty -five children were immunocompromised by their underlying conditions or therapeutic regimen. Thirty-five children were managed conservatively with resolution of PI. Two patients, however, required surgery and one patient died. Conclusion. Benign pneumatosis does occur in children. The majority have underlying risk factors, most commonly related to immunosuppression. Clinical deterioration is the most useful indicator for surgical intervention. In most patients PI resolves with conservative management. (orig.)

  3. Benign acute childhood myositis.

    Science.gov (United States)

    Rajajee, Sarala; Ezhilarasi, S; Rajarajan, K

    2005-05-01

    To describe the clinical and laboratory features of benign acute childhood myositis. 40 children of BACM were seen during October 2001 to February 2002, 22 (52%) were male with mean age of 5.3 years. Duration of illness was 3.97 days. Preceding symptoms included fever, leg pain, vomiting and inability to walk. A provisional diagnosis of viral myositis was made in 26 (66%). Guillian Barre Syndrome was the most common referral diagnosis. 11 (27.5%) children had leucopenia with lymphocytic response and 16 (40%) had thrombocytopenia. CRP was negative in 32 (80%). CPK was markedly elevated (more than 1000 IU/l) in 18 (45%) and more than 500 IU/l in 11 (27.5%) remaining between 200 to 500 IU/l. Associated features were hepatitis (elevated SGOT & SGPT) in 28 (70%) and shock in 5 (12.5%). Serological test were indicative of dengue virus (Elisa PAN BIO) in 20 (50%) of which 8 (25%) were primary dengue and 12 (30%) were secondary dengue. The outcome of therapy mainly supportive were excellent. Benign acute myositis occurs often in association with viral infection. In the present study, Dengue virus was positive in 20 (50%) children. Benign acute myositis can be differentiated from more serious causes of walking difficulty by presence of calf and thigh muscle tenderness on stretching, normal power and deep tendon reflex and elevated CPK.

  4. THE DETONATION MECHANISM OF THE PULSATIONALLY ASSISTED GRAVITATIONALLY CONFINED DETONATION MODEL OF Type Ia SUPERNOVAE

    Energy Technology Data Exchange (ETDEWEB)

    Jordan, G. C. IV; Graziani, C.; Weide, K.; Norris, J.; Hudson, R.; Lamb, D. Q. [Flash Center for Computational Science, University of Chicago, Chicago, IL 60637 (United States); Fisher, R. T. [Department of Physics, University of Massachusetts Dartmouth, 285 Old Westport Road, North Dartmouth, MA 02740 (United States); Townsley, D. M. [Department of Physics and Astronomy, University of Alabama, Tuscaloosa, AL 35487 (United States); Meakin, C. [Steward Observatory, University of Arizona, Tucson, AZ 85721 (United States); Reid, L. B. [NTEC Environmental Technology, Subiaco WA 6008 (Australia)

    2012-11-01

    We describe the detonation mechanism composing the 'pulsationally assisted' gravitationally confined detonation (GCD) model of Type Ia supernovae. This model is analogous to the previous GCD model reported in Jordan et al.; however, the chosen initial conditions produce a substantively different detonation mechanism, resulting from a larger energy release during the deflagration phase. The resulting final kinetic energy and {sup 56}Ni yields conform better to observational values than is the case for the 'classical' GCD models. In the present class of models, the ignition of a deflagration phase leads to a rising, burning plume of ash. The ash breaks out of the surface of the white dwarf, flows laterally around the star, and converges on the collision region at the antipodal point from where it broke out. The amount of energy released during the deflagration phase is enough to cause the star to rapidly expand, so that when the ash reaches the antipodal point, the surface density is too low to initiate a detonation. Instead, as the ash flows into the collision region (while mixing with surface fuel), the star reaches its maximally expanded state and then contracts. The stellar contraction acts to increase the density of the star, including the density in the collision region. This both raises the temperature and density of the fuel-ash mixture in the collision region and ultimately leads to thermodynamic conditions that are necessary for the Zel'dovich gradient mechanism to produce a detonation. We demonstrate feasibility of this scenario with three three-dimensional (3D), full star simulations of this model using the FLASH code. We characterized the simulations by the energy released during the deflagration phase, which ranged from 38% to 78% of the white dwarf's binding energy. We show that the necessary conditions for detonation are achieved in all three of the models.

  5. Estimating heats of detonation and detonation velocities of aromatic energetic compounds

    Energy Technology Data Exchange (ETDEWEB)

    Keshavarz, Mohammad Hossein [Department of Chemistry, Malek-ashtar University of Technology, Shahin-shahr, P. O. Box 83145/115 (Iran)

    2008-12-15

    A new method is introduced to predict reliable estimation of heats of detonation of aromatic energetic compounds. At first step, this procedure assumes that the heat of detonation of an explosive compound of composition C{sub a}H{sub b}N{sub c}O{sub d} can be approximated as the difference between the heat of formation of all H{sub 2}O-CO{sub 2} arbitrary (H{sub 2}O, CO{sub 2}, N{sub 2}) detonation products and that of the explosive, divided by the formula weight of the explosive. Overestimated results based on (H{sub 2}O-CO{sub 2} arbitrary) can be corrected in the next step. Predicted heats of detonation of pure energetic compounds with the product H{sub 2}O in the liquid state for 31 aromatic energetic compounds have a root mean square (rms) deviation of 2.08 and 0.34 kJ g{sup -1} from experiment for (H{sub 2}O-CO{sub 2} arbitrary) and new method, respectively. The new method also gives good results as compared to the second sets of decomposition products, which consider H{sub 2},N{sub 2}, H{sub 2}O,CO, and CO{sub 2} as major gaseous products. It is shown here how the predicted heats of detonation by the new method can be used to obtain reliable estimation of detonation velocity over a wide range of loading densities. (Abstract Copyright [2008], Wiley Periodicals, Inc.)

  6. A library of prompt detonation reaction zone data

    Energy Technology Data Exchange (ETDEWEB)

    Souers, P. C., LLNL

    1998-06-01

    Tables are given listing literature data that allows calculation of sonic reaction zones at or near steady-state for promptly detonating explosive cylinders. The data covers homogeneous, heterogeneous, composite, inorganic and binary explosives and allows comparison across the entire explosive field. Table 1 lists detonation front curvatures. Table 2 lists Size Effect data, i.e. the change of detonation velocity with cylinder radius. Table 3 lists failure radii and detonation velocities. Table 4 lists explosive compositions. A total of 51 references dating back into the 1950`s are given. Calculated reaction zones, radii of curvature and growth rate coefficients are listed.

  7. Laser driven detonation waves above a solid target

    International Nuclear Information System (INIS)

    Emmony, D.C.

    1975-01-01

    The interaction of a TEA CO 2 laser pulse with a carbon target in an argon atmosphere (p approximately mmHg) is shown to produce a double detonation wave system. The laser driven detonation wave becomes the most important as the gas pressure is increased. Calculation of the energy in the detonation waves is in good agreement with the incident laser energy at different times during the main laser pulse and the long tail. The observation of the incident laser detonation wave accounts for the anomalous energies reported previously. (Auth.)

  8. Hydroxyapatite Reinforced Coatings with Incorporated Detonationally Generated Nanodiamonds

    International Nuclear Information System (INIS)

    Pramatarova, L.; Pecheva, E.; Hikov, T.; Fingarova, D.; Dimitrova, R.; Spassov, T.; Krasteva, N.; Mitev, D.

    2010-01-01

    We studied the effect of the substrate chemistry on the morphology of hydroxyapatite-detonational nanodiamond composite coatings grown by a biomimetic approach (immersion in a supersaturated simulated body fluid). When detonational nanodiamond particles were added to the solution, the morphology of the grown for 2 h composite particles was porous but more compact then that of pure hydroxyapatite particles. The nanodiamond particles stimulated the hydroxyapatite growth with different morphology on the various substrates (Ti, Ti alloys, glasses, Si, opal). Biocompatibility assay with MG63 osteoblast cells revealed that the detonational nanodiamond water suspension with low and average concentration of the detonational nanodiamond powder is not toxic to living cells.

  9. 19th Biannual Symposium of the German Aerospace Aerodynamics Association (STAB) and the German Society for Aeronautics and Astronautics (DGLR)

    CERN Document Server

    Heller, Gerd; Krämer, Ewald; Wagner, Claus; Breitsamter, Christian

    2016-01-01

    This book presents contributions to the 19th biannual symposium of the German Aerospace Aerodynamics Association (STAB) and the German Society for Aeronautics and Astronautics (DGLR). The individual chapters reflect ongoing research conducted by the STAB members in the field of numerical and experimental fluid mechanics and aerodynamics, mainly for (but not limited to) aerospace applications, and cover both nationally and EC-funded projects. Special emphasis is given to collaborative research projects conducted by German scientists and engineers from universities, research-establishments and industries. By addressing a number of cutting-edge applications, together with the relevant physical and mathematics fundamentals, the book provides readers with a comprehensive overview of the current research work in the field. Though the book’s primary emphasis is on the aerospace context, it also addresses further important applications, e.g. in ground transportation and energy. .

  10. Radiotherapy of benign diseases

    International Nuclear Information System (INIS)

    Haase, W.

    1982-01-01

    Still today radiotherapy is of decisive relevance for several benign diseases. The following ones are briefly described in this introductory article: 1. Certain inflammatory and degenerative diseases as furuncles in the face, acute thrombophlebitis, recurrent sudoriparous abscesses, degenerative skeletal diseases, cervical syndrome and others; 2. rheumatic joint diseases; 3. Bechterew's disease; 4. primary presenile osteoporosis; 5. synringomyelia; 6. endocrine ophthalmopathy; 7. hypertrophic processes of the connective tissue; 8. hemangiomas. A detailed discussion and a profit-risk analysis is provided in the individual chapters of the magazine. (MG) [de

  11. Endovascular Repair of an Actively Hemorrhaging Stab Wound Injury to the Abdominal Aorta

    International Nuclear Information System (INIS)

    Hussain, Qasim; Maleux, Geert; Heye, Sam; Fourneau, Inge

    2008-01-01

    Traumatic injury of the abdominal aorta is rare and potentially lethal (Yeh et al., J Vasc Surg 42(5):1007-1009, 2005; Chicos et al., Chirurgia (Bucur) 102(2):237-240, 2007) as it can result in major retroperitoneal hemorrhage, requiring an urgent open surgery. In case of concomitant bowel injury or other conditions of hostile abdomen, endovascular repair can be an alternative treatment. This case report deals with a 50-year-old man presenting at the emergency ward with three stab wounds: two in the abdomen and one in the chest. During explorative laparotomy, liver laceration and bowel perforation were repaired. One day later, abdominal CT-scan revealed an additional retroperitoneal hematoma associated with an aortic pseudoaneurysm, located anteriorly 3 cm above the aortic bifurcation. Because of the risk of graft infection, an endovascular repair of the aortic injury using a Gore excluder stent-graft was performed. Radiological and clinical follow-up revealed a gradual shrinkage of the pseudo-aneurysm and no sign of graft infection at two years' follow-up.

  12. [Forensic medical expertise of the stab wounds: the current state-of-the art].

    Science.gov (United States)

    Sarkisian, B A; Karpov, D A

    2014-01-01

    This review of special literature encompasses the publications on the injuries inflicted by piercing objects. The results of analysis of these materials indicate that both the mechanisms of formation and the morphological features of stab wounds and damages to the clothes are studied perfectly well. Their shape and morphological patterns are shown to be dependent on the size, shape, and cross-section area of the great variety of the piercing objects. However, investigations carried out thus far did not take into consideration the formation of the signs of skin plastic deformation, such as edge portions of borderline thickening, stretching of epidermis over the walls, transformation of the epidermal network pattern into longitudinal folding, etc. It is concluded that further studies are necessary to better characterize injuries inflicted by piercing objects differing in the sharpness and the shape of cross section and thereby to obtain a deeper insight in the morphological features. It can be expected that such studies will provide a basis for the development of criteria for the individual and intra-group expert identification of the traumatic agents.

  13. The spectrum of injuries resulting from posterior abdominal stab wounds: a South African experience.

    Science.gov (United States)

    Kong, V Y; Oosthuizen, G V; Clarke, D L

    2015-05-01

    The spectrum of injury associated with anterior abdominal stab wounds (SWs) is well established. The literature on the spectrum of organ injury associated with SWs to the posterior abdomen, however, is limited. We reviewed our experience of 105 consecutive patients who had established indications for laparotomy managed over a 4-year period in a high volume trauma service in South Africa. Of the 105 patients, 97 (92%) were male and the overall mean age was 24 years. Fifty-seven patients (54%) had immediate indications for laparotomy. The remaining 48 patients (46%) initially underwent active clinical observation and the indications for laparotomy became apparent during the observation period. Of the 105 laparotomies performed, 94 (90%) were positive and 11 (10%) were negative. Of the 94 positive laparotomies, 92 were therapeutic and 2 were non-therapeutic. A total of 176 organ injuries were identified: 50 (53%) of the 94 patients sustained a single organ injury while the remaining 44 (47%) sustained multiple organ injuries. The most commonly injured organs were the colon (n=63), spleen (n=21) and kidney (n=19). The pattern of intra-abdominal injuries secondary to SWs to the posterior abdomen is different to that seen with the anterior abdomen. Colonic injury is most commonly encountered, followed by injuries to the spleen and kidney. Clinicians must remain vigilant because of the potential for occult injuries.

  14. Determining injuries from posterior and flank stab wounds using computed tomography tractography.

    Science.gov (United States)

    Bansal, Vishal; Reid, Chris M; Fortlage, Dale; Lee, Jeanne; Kobayashi, Leslie; Doucet, Jay; Coimbra, Raul

    2014-04-01

    Unlike anterior stab wounds (SW), in which local exploration may direct management, posterior SW can be challenging to evaluate. Traditional triple contrast computed tomography (CT) imaging is cumbersome and technician-dependent. The present study examines the role of CT tractography as a strategy to manage select patients with back and flank SW. Hemodynamically stable patients with back and flank SW were studied. After resuscitation, Betadine- or Visipaque®-soaked sterile sponges were inserted into each SW for the estimated depth of the wound. Patients underwent abdominal helical CT scanning, including intravenous contrast, as the sole abdominal imaging study. Images were reviewed by an attending radiologist and trauma surgeon. The tractogram was evaluated to determine SW trajectory and injury to intra- or retroperitoneal organs, vascular structures, the diaphragm, and the urinary tract. Complete patient demographics including operative management and injuries were collected. Forty-one patients underwent CT tractography. In 11 patients, tractography detected violation of the intra- or retroperitoneal cavity leading to operative exploration. Injuries detected included: the spleen (two), colon (one), colonic mesentery (one), kidney (kidney), diaphragm (kidney), pneumothorax (seven), hemothorax (two), iliac artery (one), and traumatic abdominal wall hernia (two). In all patients, none had negative CT findings that failed observation. In this series, CT tractography is a safe and effective imaging strategy to evaluate posterior torso SW. It is unknown whether CT tractography is superior to traditional imaging modalities. Other uses for CT tractography may include determining trajectory from missile wounds and tangential penetrating injuries.

  15. Stiletto stabbing: penetrating injury to the hypothalamus with hyperacute diabetes insipidus.

    Science.gov (United States)

    Itshayek, Eyal; Gomori, John Moshe; Spektor, Sergey; Cohen, José E

    2010-12-01

    Diabetes insipidus (DI) is a well documented complication observed after traumatic head injuries. We report a case of hyperacute onset DI in a 19-year-old male who sustained a hypothalamic-pituitary injury when he was stabbed in the head with a 30-cm long thin-bladed knife. At CT, our patient showed significant hemorrhagic contusions of the lower hypothalamus. He developed polydipsia, polyuria, and mild hypernatremia in the Emergency Department. Diagnostic digital subtraction angiography showed a hypervascular congestive pituitary gland with prominent draining veins. On the third day his hypernatremia became severe (183mEq/L). He was managed with parenteral fluids and a regimen of intranasal DDAVP (1-desamino 8-d-arginine vasopressin), leading to improved plasmatic sodium levels, urine output, and urinary specific gravity. In patients presenting with hyperacute posttraumatic DI, emergency room physicians and neurosurgeons should rule out direct injury to the hypothalamus and/or the posterior lobe of the pituitary, and initiate early pharmacological treatment. Copyright © 2010 Elsevier B.V. All rights reserved.

  16. A new method of ergonomic testing of gloves protecting against cuts and stabs during knife use.

    Science.gov (United States)

    Irzmańska, Emilia; Tokarski, Tomasz

    2017-05-01

    The paper presents a new method of ergonomic evaluation of gloves protecting against cuts and stabs during knife use, consisting of five manual dexterity tests. Two of them were selected based on the available literature and relevant safety standards, and three were developed by the authors. All of the tests were designed to simulate occupational tasks associated with meat processing as performed by the gloved hand in actual workplaces. The tests involved the three most common types of protective gloves (knitted gloves made of a coverspun yarn, metal mesh gloves, and metal mesh gloves with an ergonomic polyurethane tightener) and were conducted on a group of 20 males. The loading on the muscles of the upper limb (adductor pollicis, flexor carpi ulnaris, flexor carpi radialis, and biceps brachii) was measured using surface electromyography. For the obtained muscle activity values, correlations were found between the glove type and loading of the upper limb. ANOVA showed that the activity of all muscles differed significantly between the five tests. A relationship between glove types and electromyographic results was confirmed at a significance level of α = 0.05. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Deflagration to detonation transition in thermonuclear supernovae

    International Nuclear Information System (INIS)

    Charignon, Camille

    2013-01-01

    Type Ia supernovae are an important tool to determine the expansion history of our Universe. Thus, considerable attention has been given to both observations and models of these events. The most popular explosion model is the central ignition of a deflagration in the dense C+O interior of a Chandrasekhar mass white dwarf, followed by a transition to a detonation (TDD). We study in this thesis a new mechanism for this transition. The most robust and studied progenitor model and the postulated mechanism for the TDD, the so called 'Zel'dovich gradient mechanism', are presented. State of the art 3D simulations of such a delayed detonation, at the price of some adjustments, can indeed reproduce observables. But due to largely unresolved physical scales, such simulations cannot explain the TDD by themselves, and especially, the physical mechanism which triggers this transition - which is not yet understood, even on Earth, for unconfined media. It is then discussed why the current Zel'dovich mechanism might be too constraining for a SN Ia model, pointing to a new approach, which is the core result of this thesis.In the final part, our alternative model for DDT in supernovae, the acoustic heating of the pre-supernova envelope, is presented. A planar model first proves that small amplitude acoustic perturbations (generated by a turbulent flame) are actually amplified in a steep density gradient, up to a point where they turn into shocks able to trigger a detonation. Then, this mechanism is applied to more realistic models, taking into account, in spherical geometry, the expanding envelope. A parametric study demonstrates the validity of the model for a reasonable range of acoustic wave amplitudes and frequencies.To conclude, some exploratory 2D and 3D MHD simulations, seeking for realistic acoustic source compatible with our mechanism, are presented. (author) [fr

  18. Benign joint hypermobility syndrome

    Directory of Open Access Journals (Sweden)

    Iwona Słowińska

    2014-11-01

    Full Text Available Benign joint hypermobility syndrome (BJHS, commonly known as loose ligament syndrome, is a non-inflammatory rheumatic condition. It is characterised by a greater than normal range of motion of the joints of the limbs and spine. The prevalence of the syndrome in preschool-age children is estimated to be between 2% and 30%, depending on ethnic background (with higher prevalence in Asian and African populations, occurring most often in families with a history of the condition and more frequently in girls. This paper presents a case report of a 12-year-old girl. A broad differential diagnostic approach to recurrent joint inflammation with joint effusion and pain made it possible to establish a diagnosis of benign joint hypermobility syndrome. The child met the Brighton criteria; her Beighton score was 7 out of 9. Patient education aimed at eliminating abnormal joint movement and an appropriate rehabilitation programme play key roles in the treatment of BJHS.

  19. Benign fibroosseous lesions

    Directory of Open Access Journals (Sweden)

    Cansu Köseoğlu Seçgin

    2016-05-01

    Full Text Available Benign fibroosseous lesions represent a group of lesions that share the same basic evolutive mechanism and are characterized by replacement of normal bone with a fibrous connective tissue that gradually undergoes mineralization. These lesions are presented by a variety of diseases including developmental, reactive-dysplastic processes and neoplasms. Depending on the nature and amount of calcified tissue, they can be observed as radiolucent, mixed or radiopaque. Their radiographic features could be well-defined or indistinguishable from the surrounding bone tissue. They can be asymptomatic as in osseous dysplasias and can be detected incidentally on radiographs, or they can lead to expansion in the affected bone as in ossifying fibroma. All fibroosseous lesions seen in the jaws and face are variations of the same histological pattern. Therefore, detailed clinical and radiographic evaluation in differential diagnosis is important. In this review, fibroosseous benign lesions are classified as osseous dysplasia, fibrous dysplasia and fibroosseous tumors; and radiographic features and differential diagnosis of these lesions are reviewed taking into account this classification.

  20. Carbon deflagration supernova, an alternative to carbon detonation

    Energy Technology Data Exchange (ETDEWEB)

    Nomoto, K; Sugimoto, D [Tokyo Univ. (Japan). Coll. of General Education; Neo, S [Kyoto Univ. (Japan). Dept. of Physics

    1976-02-01

    As an alternative to the carbon detonation, a carbon deflagration supernova model is presented by a full hydrodynamic computation. A deflagration wave, which propagates through the core due to convective heat transport, does not grow into detonation. Though it results in a complete disruption of the star, the difficulty of overproduction of iron peak elements can be avoided if the deflagration is relatively slow.

  1. STUDY OF THE DETONATION PHASE IN THE GRAVITATIONALLY CONFINED DETONATION MODEL OF TYPE Ia SUPERNOVAE

    International Nuclear Information System (INIS)

    Meakin, Casey A.; Townsley, Dean; Jordan, George C.; Truran, James; Lamb, Don; Seitenzahl, Ivo

    2009-01-01

    We study the gravitationally confined detonation (GCD) model of Type Ia supernovae (SNe Ia) through the detonation phase and into homologous expansion. In the GCD model, a detonation is triggered by the surface flow due to single-point, off-center flame ignition in carbon-oxygen white dwarfs (WDs). The simulations are unique in terms of the degree to which nonidealized physics is used to treat the reactive flow, including weak reaction rates and a time-dependent treatment of material in nuclear statistical equilibrium (NSE). Careful attention is paid to accurately calculating the final composition of material which is burned to NSE and frozen out in the rapid expansion following the passage of a detonation wave over the high-density core of the WD; and an efficient method for nucleosynthesis postprocessing is developed which obviates the need for costly network calculations along tracer particle thermodynamic trajectories. Observational diagnostics are presented for the explosion models, including abundance stratifications and integrated yields. We find that for all of the ignition conditions studied here a self-regulating process comprised of neutronization and stellar expansion results in final 56 Ni masses of ∼1.1 M sun . But, more energetic models result in larger total NSE and stable Fe-peak yields. The total yield of intermediate mass elements is ∼0.1 M sun and the explosion energies are all around 1.5 x 10 51 erg. The explosion models are briefly compared to the inferred properties of recent SN Ia observations. The potential for surface detonation models to produce lower-luminosity (lower 56 Ni mass) SNe is discussed.

  2. Numerical computation of linear instability of detonations

    Science.gov (United States)

    Kabanov, Dmitry; Kasimov, Aslan

    2017-11-01

    We propose a method to study linear stability of detonations by direct numerical computation. The linearized governing equations together with the shock-evolution equation are solved in the shock-attached frame using a high-resolution numerical algorithm. The computed results are processed by the Dynamic Mode Decomposition technique to generate dispersion relations. The method is applied to the reactive Euler equations with simple-depletion chemistry as well as more complex multistep chemistry. The results are compared with those known from normal-mode analysis. We acknowledge financial support from King Abdullah University of Science and Technology.

  3. Laser image recording on detonation nanodiamond films

    International Nuclear Information System (INIS)

    Mikheev, G M; Mikheev, K G; Mogileva, T N; Puzyr, A P; Bondar, V S

    2014-01-01

    A focused He – Ne laser beam is shown to cause local blackening of semitransparent detonation nanodiamond (DND) films at incident power densities above 600 W cm -2 . Data obtained with a Raman spectrometer and low-power 632.8-nm laser source indicate that the blackening is accompanied by a decrease in broadband background luminescence and emergence of sharp Raman peaks corresponding to the structures of nanodiamond and sp 2 carbon. The feasibility of image recording on DND films by a focused He – Ne laser beam is demonstrated. (letters)

  4. Laser image recording on detonation nanodiamond films

    Energy Technology Data Exchange (ETDEWEB)

    Mikheev, G M; Mikheev, K G; Mogileva, T N [Institute of Mechanics, Ural Branch of the Russian Academy of Sciences, Izhevsk (Russian Federation); Puzyr, A P; Bondar, V S [Institute of Biophysics, Siberian Branch of the Russian Academy of Sciences (Russian Federation)

    2014-01-31

    A focused He – Ne laser beam is shown to cause local blackening of semitransparent detonation nanodiamond (DND) films at incident power densities above 600 W cm{sup -2}. Data obtained with a Raman spectrometer and low-power 632.8-nm laser source indicate that the blackening is accompanied by a decrease in broadband background luminescence and emergence of sharp Raman peaks corresponding to the structures of nanodiamond and sp{sup 2} carbon. The feasibility of image recording on DND films by a focused He – Ne laser beam is demonstrated. (letters)

  5. Detonation engine fed by acetylene-oxygen mixture

    Science.gov (United States)

    Smirnov, N. N.; Betelin, V. B.; Nikitin, V. F.; Phylippov, Yu. G.; Koo, Jaye

    2014-11-01

    The advantages of a constant volume combustion cycle as compared to constant pressure combustion in terms of thermodynamic efficiency has focused the search for advanced propulsion on detonation engines. Detonation of acetylene mixed with oxygen in various proportions is studied using mathematical modeling. Simplified kinetics of acetylene burning includes 11 reactions with 9 components. Deflagration to detonation transition (DDT) is obtained in a cylindrical tube with a section of obstacles modeling a Shchelkin spiral; the DDT takes place in this section for a wide range of initial mixture compositions. A modified ka-omega turbulence model is used to simulate flame acceleration in the Shchelkin spiral section of the system. The results of numerical simulations were compared with experiments, which had been performed in the same size detonation chamber and turbulent spiral ring section, and with theoretical data on the Chapman-Jouguet detonation parameters.

  6. Numerical Study on Critical Wedge Angle of Cellular Detonation Reflections

    International Nuclear Information System (INIS)

    Gang, Wang; Kai-Xin, Liu; De-Liang, Zhang

    2010-01-01

    The critical wedge angle (CWA) for the transition from regular reflection (RR) to Mach reflection (MR) of a cellular detonation wave is studied numerically by an improved space-time conservation element and solution element method together with a two-step chemical reaction model. The accuracy of that numerical way is verified by simulating cellular detonation reflections at a 19.3° wedge. The planar and cellular detonation reflections over 45°–55° wedges are also simulated. When the cellular detonation wave is over a 50° wedge, numerical results show a new phenomenon that RR and MR occur alternately. The transition process between RR and MR is investigated with the local pressure contours. Numerical analysis shows that the cellular structure is the essential reason for the new phenomenon and the CWA of detonation reflection is not a certain angle but an angle range. (fundamental areas of phenomenology(including applications))

  7. Effect of Mixture Pressure and Equivalence Ratio on Detonation Cell Size for Hydrogen-Air Mixtures

    Science.gov (United States)

    2015-06-01

    In order to design combustion chambers for detonating engines, specifically PDEs and RDEs , the cell size is needed. Higher than atmospheric...8 Figure 4. RDE dimensions ................................................................................................ 11...Technology DDT Deflagration to Detonation MAPE Mean Absolute Percent Error PDE Pulsed Detonation Engine RDE Rotating Detonation Engine ZND

  8. The detection of metallic residues in skin stab wounds by means of SEM-EDS: A pilot study.

    Science.gov (United States)

    Palazzo, Elisa; Amadasi, Alberto; Boracchi, Michele; Gentile, Guendalina; Maciocco, Francesca; Marchesi, Matteo; Zoja, Riccardo

    2018-05-01

    The morphological analysis of stab wounds may often not be accurate enough to link it with the type of wounding weapon, but a further evaluation may be performed with the search for metallic residues left during the contact between the instrument and the skin. In this study, Scanning Electron Microscopy-Energy Dispersive Spectroscopy (SEM-EDS) was applied to the study of cadaveric stab wounds performed with kitchen knives composed of iron, chromium and nickel, in order to verify the presence of metallic residues on the wound's edge. Two groups of 10 corpses were selected: group A, including victims of stab wounds and a control group B (died of natural causes). Samplings were performed on the lesions and in intact areas of group A, whereas in group B sampling were performed in non-exposed intact skin. Samples were then analysed with optical microscopy and SEM-EDS. In group A, optical microscopic analysis showed the presence of vital haemorrhagic infiltration, while SEM-EDS showed evidence of microscopic metal traces, isolated or clustered, consisting of iron, chromium and nickel. Moreover, in two cases organic residues of calcium and phosphate were detected, as a probable sign of bone lesion. Control samples (group A in intact areas and group B), were negative for the search of exogenous material to optical microscopy and SEM-EDS. The results show the utility and possible application of the SEM-EDS in theidentification of metallic residues from sharp weapons on the skin. Copyright © 2017 The Chartered Society of Forensic Sciences. Published by Elsevier B.V. All rights reserved.

  9. Chemical kinetics of detonation in some liquid mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Raikova, Vlada M.; Likholatov, Evgeny A. [Mendeleev University of Chemical Technology, Moscow (Russian Federation)

    2005-09-01

    The main objective of this work is to study the chemical kinetics of detonation reactions in some nitroester mixtures and solutions of nitrocompounds in concentrated nitric acid. The main source of information on chemical kinetics in the detonation wave was the experimental dependence of failure diameter on composition of mixtures. Calculations were carried out in terms of classic theory of Dremin using the SGKR computer code. Effective values for the activation energies and pre-exponential factors for detonation reactions in the mixtures under investigation have been defined. (Abstract Copyright [2005], Wiley Periodicals, Inc.)

  10. Geometry-specific scaling of detonation parameters from front curvature

    International Nuclear Information System (INIS)

    Jackson, Scott I.; Short, Mark

    2011-01-01

    It has previously been asserted that classical detonation curvature theory predicts that the critical diameter and the diameter-effect curve of a cylindrical high-explosive charge should scale with twice the thickness of an analogous two-dimensional explosive slab. The varied agreement of experimental results with this expectation have led some to question the ability of curvature-based concepts to predict detonation propagation in non-ideal explosives. This study addresses such claims by showing that the expected scaling relationship (hereafter referred to d = 2w) is not consistent with curvature-based Detonation Shock Dynamics (DSD) theory.

  11. Combustion and Magnetohydrodynamic Processes in Advanced Pulse Detonation Rocket Engines

    Science.gov (United States)

    Cole, Lord Kahil

    A number of promising alternative rocket propulsion concepts have been developed over the past two decades that take advantage of unsteady combustion waves in order to produce thrust. These concepts include the Pulse Detonation Rocket Engine (PDRE), in which repetitive ignition, propagation, and reflection of detonations and shocks can create a high pressure chamber from which gases may be exhausted in a controlled manner. The Pulse Detonation Rocket Induced Magnetohydrodynamic Ejector (PDRIME) is a modification of the basic PDRE concept, developed by Cambier (1998), which has the potential for performance improvements based on magnetohydrodynamic (MHD) thrust augmentation. The PDRIME has the advantage of both low combustion chamber seeding pressure, per the PDRE concept, and efficient energy distribution in the system, per the rocket-induced MHD ejector (RIME) concept of Cole, et al. (1995). In the initial part of this thesis, we explore flow and performance characteristics of different configurations of the PDRIME, assuming quasi-one-dimensional transient flow and global representations of the effects of MHD phenomena on the gas dynamics. By utilizing high-order accurate solvers, we thus are able to investigate the fundamental physical processes associated with the PDRIME and PDRE concepts and identify potentially promising operating regimes. In the second part of this investigation, the detailed coupling of detonations and electric and magnetic fields are explored. First, a one-dimensional spark-ignited detonation with complex reaction kinetics is fully evaluated and the mechanisms for the different instabilities are analyzed. It is found that complex kinetics in addition to sufficient spatial resolution are required to be able to quantify high frequency as well as low frequency detonation instability modes. Armed with this quantitative understanding, we then examine the interaction of a propagating detonation and the applied MHD, both in one-dimensional and two

  12. Diagnostic techniques in deflagration and detonation studies.

    Science.gov (United States)

    Proud, William G; Williamson, David M; Field, John E; Walley, Stephen M

    2015-12-01

    Advances in experimental, high-speed techniques can be used to explore the processes occurring within energetic materials. This review describes techniques used to study a wide range of processes: hot-spot formation, ignition thresholds, deflagration, sensitivity and finally the detonation process. As this is a wide field the focus will be on small-scale experiments and quantitative studies. It is important that such studies are linked to predictive models, which inform the experimental design process. The stimuli range includes, thermal ignition, drop-weight, Hopkinson Bar and Plate Impact studies. Studies made with inert simulants are also included as these are important in differentiating between reactive response and purely mechanical behaviour.

  13. The masonry behaviour under contact detonation

    Directory of Open Access Journals (Sweden)

    Marin Lupoae

    2017-03-01

    Full Text Available Breaching in masonry wall as a process of quick intervention of special forces in emergency cases, may require the use of explosive charges. In order to maximize the explosive effects on the wall and to minimize the shock wave and fragments propulsion, such breaching systems usually use a water layer which cover the explosive charge. The thickness of the water layer has a significant influence both on the mitigation of unwanted effects and enhancing the demolition effect, but also increases the mass of the system which can have negative consequences on the maneuverability and rapidity of intervention, respectivly. In this respect, the paper under consideration addresses numerical and experimental research on masonry walls to determine the behavior of mortar and brick under contact detonation and to establish an optimal water layer thickness to balance the breaching system requirement related to the mass on the one hand and effects and offered protection on the other hand.

  14. Blasting detonators incorporating semiconductor bridge technology

    Energy Technology Data Exchange (ETDEWEB)

    Bickes, R.W. Jr.

    1994-05-01

    The enormity of the coal mine and extraction industries in Russia and the obvious need in both Russia and the US for cost savings and enhanced safety in those industries suggests that joint studies and research would be of mutual benefit. The author suggests that mine sites and well platforms in Russia offer an excellent opportunity for the testing of Sandia`s precise time-delay semiconductor bridge detonators, with the potential for commercialization of the detonators for Russian and other world markets by both US and Russian companies. Sandia`s semiconductor bridge is generating interest among the blasting, mining and perforation industries. The semiconductor bridge is approximately 100 microns long, 380 microns wide and 2 microns thick. The input energy required for semiconductor bridge ignition is one-tenth the energy required for conventional bridgewire devices. Because semiconductor bridge processing is compatible with other microcircuit processing, timing and logic circuits can be incorporated onto the chip with the bridge. These circuits can provide for the precise timing demanded for cast effecting blasting. Indeed tests by Martin Marietta and computer studies by Sandia have shown that such precise timing provides for more uniform rock fragmentation, less fly rock, reduce4d ground shock, fewer ground contaminants and less dust. Cost studies have revealed that the use of precisely timed semiconductor bridges can provide a savings of $200,000 per site per year. In addition to Russia`s vast mineral resources, the Russian Mining Institute outside Moscow has had significant programs in rock fragmentation for many years. He anticipated that collaborative studies by the Institute and Sandia`s modellers would be a valuable resource for field studies.

  15. Refractory benign esophageal strictures

    Directory of Open Access Journals (Sweden)

    Gopal Goyal

    2016-01-01

    Full Text Available Refractory benign esophageal stricture (RBES is a frequently encountered problem worldwide. These strictures arise from various causes such as corrosive injury, radiation therapy, peptic origin, ablative therapy, and after surgery. Most strictures can be treated successfully with endoscopic dilatation using bougies or balloons, with only a few complications. Those patients who fail after serial dilatation with bougies or balloons will come to the category of refractory strictures. Dilatation combined with intralesional steroid injections can be considered for peptic strictures, whereas incisional therapy has been demonstrated to be effective for short anastomotic strictures. When these therapeutic options do not resolve the stenosis, stent placement should be considered. Self-bougienage can be proposed to a selected group of patients with a proximal stenosis. Most of the patients of RBES respond to above-mentioned treatment and occasional patient may require surgery as the final treatment option. This review aims to provide a comprehensive approach toward endoscopic management of RBESs based on current literature and personal experience.

  16. Nihilism: a benign denial.

    Science.gov (United States)

    Skandalakis, John E; Mirilas, Petros

    2003-06-01

    Nihilism is the belief that all possible knowledge on a given topic has been amassed and codified. Ranging from benign denial to deliberate attempts at excommunication, nihilism is often encountered in the history of medicine. Eustachius, Columbus, and Sylvius strongly criticized Vesalius and defended the authority of Galen. Riolan fervently rejected Harvey's monumental work on the circulation of blood. Gross stated that no honest and sensible surgeon would ever sanction thyroidectomy. Sandstrom's discovery of the parathyroids was met with silence. Transplantation of parathyroids by Mandl was not appreciated when announced. Aristotle's dictum that the heart cannot withstand serious injury led to Paget's statement that cardiac surgery had reached the limits set by nature, which no new techniques could overcome. The first Billroth I operation was welcomed as, "Hopefully, also the last." Pancreatic surgery was opposed because the organ was of no clinical interest and was impossible for surgeons to reach. Pancreatic transplantation was rejected for many years, despite good results. When Blundell used blood transfusion for postpartum hemorrhage, critics averred that his next exploit would be radical removal of the spleen. Bassini stated that it could be risky to publish more about radical treatment of inguinal hernias. Carcinomas of the lower sigmoid and upper rectum were deemed untreatable because of their inaccessibility. Colostomy during pediatric surgery was rejected many times. Although it is difficult for the human mind to move from a familiar point of view, this propensity should not infect science, thereby impeding advancement.

  17. Numerical Investigation on the Propagation Mechanism of Steady Cellular Detonations in Curved Channels

    International Nuclear Information System (INIS)

    Li Jian; Ning Jian-Guo; Zhao Hui; Wang Cheng; Hao Li

    2015-01-01

    The propagation mechanism of steady cellular detonations in curved channels is investigated numerically with a detailed chemical reaction mechanism. The numerical results demonstrate that as the radius of the curvature decreases, detonation fails near the inner wall due to the strong expansion effect. As the radius of the curvature increases, the detonation front near the inner wall can sustain an underdriven detonation. In the case where detonation fails, a transverse detonation downstream forms and re-initiates the quenched detonation as it propagates toward the inner wall. Two kinds of propagation modes exist as the detonation is propagating in the curved channel. One is that the detonation fails first, and then a following transverse detonation initiates the quenched detonation and this process repeats itself. The other one is that without detonation failure and re-initiation, a steady detonation exists which consists of an underdriven detonation front near the inner wall subject to the diffraction and an overdriven detonation near the outer wall subject to the compression. (paper)

  18. Development and testing of pulsed and rotating detonation combustors

    Science.gov (United States)

    St. George, Andrew C.

    Detonation is a self-sustaining, supersonic, shock-driven, exothermic reaction. Detonation combustion can theoretically provide significant improvements in thermodynamic efficiency over constant pressure combustion when incorporated into existing cycles. To harness this potential performance benefit, countless studies have worked to develop detonation combustors and integrate these devices into existing systems. This dissertation consists of a series of investigations on two types of detonation combustors: the pulse detonation combustor (PDC) and the rotating detonation combustor (RDC). In the first two investigations, an array of air-breathing PDCs is integrated with an axial power turbine. The system is initially operated with steady and pulsed cold air flow to determine the effect of pulsed flow on turbine performance. Various averaging approaches are employed to calculate turbine efficiency, but only flow-weighted (e.g., mass or work averaging) definitions have physical significance. Pulsed flow turbine efficiency is comparable to steady flow efficiency at high corrected flow rates and low rotor speeds. At these conditions, the pulse duty cycle expands and the variation of the rotor incidence angle is constrained to a favorable range. The system is operated with pulsed detonating flow to determine the effect of frequency, fill fraction, and rotor speed on turbine performance. For some conditions, output power exceeds the maximum attainable value from steady constant pressure combustion due to a significant increase in available power from the detonation products. However, the turbine component efficiency estimated from classical thermodynamic analysis is four times lower than the steady design point efficiency. Analysis of blade angles shows a significant penalty due to the detonation, fill, and purge processes simultaneously imposed on the rotor. The latter six investigations focus on fundamental research of the RDC concept. A specially-tailored RDC data

  19. Laser-Supported Detonation Concept as a Space Thruster

    International Nuclear Information System (INIS)

    Fujiwara, Toshi; Miyasaka, Takeshi

    2004-01-01

    Similar to the concept of pulse detonation engine (PDE), a detonation generated in the 'combustion chamber' due to incoming laser absorption can produce the thrust basically much higher than the one that a laser-supported deflagration wave can provide. Such a laser-supported detonation wave concept has been theoretically studied by the first author for about 20 years in view of its application to space propulsion. The entire work is reviewed in the present paper. The initial condition for laser absorption can be provided by increasing the electron density using electric discharge. Thereafter, once a standing/running detonation wave is formed, the laser absorption can continuously be performed by the classical absorption mechanism called Inverse Bremsstrahlung behind a strong shock wave

  20. Theory of weakly nonlinear self-sustained detonations

    KAUST Repository

    Faria, Luiz

    2015-11-03

    We propose a theory of weakly nonlinear multidimensional self-sustained detonations based on asymptotic analysis of the reactive compressible Navier-Stokes equations. We show that these equations can be reduced to a model consisting of a forced unsteady small-disturbance transonic equation and a rate equation for the heat release. In one spatial dimension, the model simplifies to a forced Burgers equation. Through analysis, numerical calculations and comparison with the reactive Euler equations, the model is demonstrated to capture such essential dynamical characteristics of detonations as the steady-state structure, the linear stability spectrum, the period-doubling sequence of bifurcations and chaos in one-dimensional detonations and cellular structures in multidimensional detonations.

  1. Sensor for electromagnetic waves caused by nuclear detonation

    International Nuclear Information System (INIS)

    Weischedel, R.C.

    1980-01-01

    An electronic sensor is disclosed, having circuits for identifying electromagnetic radiation signals caused by nuclear detonations. Circuits also are provided for discriminating against false indications due to electromagnetic radiation caused by lightning

  2. Qualitative modeling of the dynamics of detonations with losses

    KAUST Repository

    Faria, Luiz; Kasimov, Aslan R.

    2015-01-01

    We consider a simplified model for the dynamics of one-dimensional detonations with generic losses. It consists of a single partial differential equation that reproduces, at a qualitative level, the essential properties of unsteady detonation waves, including pulsating and chaotic solutions. In particular, we investigate the effects of shock curvature and friction losses on detonation dynamics. To calculate steady-state solutions, a novel approach to solving the detonation eigenvalue problem is introduced that avoids the well-known numerical difficulties associated with the presence of a sonic point. By using unsteady numerical simulations of the simplified model, we also explore the nonlinear stability of steady-state or quasi-steady solutions. © 2014 The Combustion Institute.

  3. Theory of weakly nonlinear self-sustained detonations

    KAUST Repository

    Faria, Luiz; Kasimov, Aslan R.; Rosales, Rodolfo R.

    2015-01-01

    We propose a theory of weakly nonlinear multidimensional self-sustained detonations based on asymptotic analysis of the reactive compressible Navier-Stokes equations. We show that these equations can be reduced to a model consisting of a forced

  4. A Multidisciplinary Study of Pulse Detonation Engine Propulsion

    National Research Council Canada - National Science Library

    Santoro, Robert

    2003-01-01

    ... chemistry, injector and flow field mixing, and advanced diagnostics to study the fundamental phenomena of importance under both static and dynamic conditions representative of actual pulse detonation engine operation...

  5. Benign Breast Problems and Conditions

    Science.gov (United States)

    ... Hyperplasia: A condition in which cells in the breast ducts or lobes are increasing in number and do not look normal under a microscope. Benign: Not cancer. Biopsy: A minor surgical procedure to remove a small ...

  6. Diagnostic Imaging of Detonation Waves for Waveshaper Development

    Science.gov (United States)

    2009-07-01

    it is difficult to determine the depth of the detonation wave (due to the translucency of the sensitised nitromethane) and when it reaches the bottom...Charges For Use against Concrete Targerts, DSTO Client Report, DSTO-CR-2005-0164, 2005. [2] M. J. Murphy, R. M. Kuklo, T. A. Rambur, L. L. Switzer & M...Resnyansky, S. A. Weckert & T. Delaney, Shaping of Detonation Waves in Shaped Charges for Use against Concrete Targets: Part II, in preparation

  7. Sub-Chandrasekhar-mass White Dwarf Detonations Revisited

    Science.gov (United States)

    Shen, Ken J.; Kasen, Daniel; Miles, Broxton J.; Townsley, Dean M.

    2018-02-01

    The detonation of a sub-Chandrasekhar-mass white dwarf (WD) has emerged as one of the most promising Type Ia supernova (SN Ia) progenitor scenarios. Recent studies have suggested that the rapid transfer of a very small amount of helium from one WD to another is sufficient to ignite a helium shell detonation that subsequently triggers a carbon core detonation, yielding a “dynamically driven double-degenerate double-detonation” SN Ia. Because the helium shell that surrounds the core explosion is so minimal, this scenario approaches the limiting case of a bare C/O WD detonation. Motivated by discrepancies in previous literature and by a recent need for detailed nucleosynthetic data, we revisit simulations of naked C/O WD detonations in this paper. We disagree to some extent with the nucleosynthetic results of previous work on sub-Chandrasekhar-mass bare C/O WD detonations; for example, we find that a median-brightness SN Ia is produced by the detonation of a 1.0 {M}ȯ WD instead of a more massive and rarer 1.1 {M}ȯ WD. The neutron-rich nucleosynthesis in our simulations agrees broadly with some observational constraints, although tensions remain with others. There are also discrepancies related to the velocities of the outer ejecta and light curve shapes, but overall our synthetic light curves and spectra are roughly consistent with observations. We are hopeful that future multidimensional simulations will resolve these issues and further bolster the dynamically driven double-degenerate double-detonation scenario’s potential to explain most SNe Ia.

  8. On a stabilization mechanism for low-velocity detonations

    KAUST Repository

    Sow, Aliou; Semenko, Roman E.; Kasimov, Aslan R.

    2017-01-01

    We use numerical simulations of the reactive Lula equations to analyse the nonlinear stability of steady-state one-dimensional solutions for gaseous detonations in the presence of both momentum and heat losses. Our results point to a possible stabilization mechanism for the low-velocity detonations in such systems. The mechanism stems from the existence of a one-parameter family of solutions found in Semenko el al.

  9. Three Dimensional Analysis of Induced Detonation of Cased Explosive

    Science.gov (United States)

    2014-10-16

    hardness and ductility . RHA steel is largely used in military applications to manufacture armoured vehicles. The Johnson Cook (JC) constitutive...armour (RHA) steel were investigated through the LS-DYNA. The investigation focused on shock to detonation simulations of Composition B, with the... hot spots caused by the compression of the explosive from the initial shockwave. Detonation was also caused by pressure waves reflecting against the

  10. On a stabilization mechanism for low-velocity detonations

    KAUST Repository

    Sow, Aliou

    2017-03-08

    We use numerical simulations of the reactive Lula equations to analyse the nonlinear stability of steady-state one-dimensional solutions for gaseous detonations in the presence of both momentum and heat losses. Our results point to a possible stabilization mechanism for the low-velocity detonations in such systems. The mechanism stems from the existence of a one-parameter family of solutions found in Semenko el al.

  11. Fatal tiger attack: a case report with emphasis on typical tiger injuries characterized by partially resembling stab-like wounds.

    Science.gov (United States)

    Pathak, Hrishikesh; Borkar, Jaydeo; Dixit, Pradeep; Dhawane, Shailendra; Shrigiriwar, Manish; Dingre, Niraj

    2013-10-10

    Fatalities due to attacks by tigers on humans are uncommon and are rarely described in the medico-legal literature. We herein present a forensic investigation in a unique case of a fatal tiger attack in the wild on a 35 year old female in India by an Indian Bengal tiger (Panthera tigris tigris). The attack resulted in two pairs of puncture wounds over the nape area with occult cervical spine injuries resulting from transfixing of spine due to the tiger canines; multiple puncture wounds, numerous scratches and abrasions consistent with the tiger claw injuries and injury to the right jugulocarotid vessels. This case outlines the characteristic injury pattern from such an attack along with the multiple sources of the tiger injuries. The analysis of these injuries might reveal the motivation behind the attack and the big cat species involved in the attack. A tiger injury is sometimes compared with a stab injury, as the patterned injuries due to a tiger bite are characterized by multiple penetrating, stab-like wounds. So, a special attention is paid toward establishment of the cause of death from bites by the animal teeth under unknown circumstances of trauma and to exclude the possibility of a homicide beyond reasonable doubt in such cases. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  12. Is triple contrast computed tomographic scanning useful in the selective management of stab wounds to the back?

    Science.gov (United States)

    McAllister, E; Perez, M; Albrink, M H; Olsen, S M; Rosemurgy, A S

    1994-09-01

    We devised a protocol to prospectively manage stab wounds to the back with the hypothesis that the triple contrast computed tomographic (CT) scan is an effective means of detecting occult injury in these patients. All wounds to the back in hemodynamically stable adults were locally explored. All patients with muscular fascial penetration underwent triple contrast CT scanning utilizing oral, rectal, and IV contrast. Patients did not undergo surgical exploration if their CT scan was interpreted as negative or if the CT scan demonstrated injuries not requiring surgical intervention. Fifty-three patients were entered into the protocol. The time to complete the triple contrast CT scan ranged from 3 to 6 hours at a cost of $1050 for each scan. In 51 patients (96%), the CT scan either had negative findings (n = 31) or showed injuries not requiring exploration (n = 20). These patients did well with nonsurgical management. Two CT scans documented significant injury and led to surgical exploration and therapeutic celiotomies. Although triple contrast CT scanning was able to detect occult injury in patients with stab wounds to the back it did so at considerable cost and the results rarely altered clinical care. Therefore, its routine use in these patients is not recommended.

  13. Radiation treatment of benign diseases

    International Nuclear Information System (INIS)

    Reitan, J.B.; Flatby, J.; Backe, S.; Lundgren, L.

    1984-01-01

    The report deals with an estimation of the volume of radiation treatment of benign diseases in Norway and gives a survey of the subjective opinion of patients regarding the result of the treatment. Reported subjective recovery after radiation treatment seems to be at the same level as recovery without treatment. For an indication of the objective effect of radiation treatment of benign diseases, the subjective effect of this treatment has to be compared with objective findings

  14. Detonability of containment building atmospheres during core-meltdown accidents

    International Nuclear Information System (INIS)

    Jaung, R.; Berlad, L.; Pratt, W.

    1983-01-01

    During Core-Meltdown Accidents in Light Water Reactors, significant quantities of combustible gases could be released to the containment building. The highest possible peak pressure fields that may occur through combustion processes are associated with detonation phenomena. Accordingly, it is necessary to understand and identify the possible ways in which detonations may or may not occur. Although no comprehensive theory of detonation is currently available, there are useful guidelines, which can be derived from current theoretical concepts and the body of experimental data. This paper examines these guidelines and indicates how they may be used to evaluate the possible occurrence of detonation-related combustion processes. In particular, this study identifies three features that an initiation source must achieve if it is to ultimately result in a stable detonation. One of these features requires post-shock initial conditions that lead to very short ignition delays. This concept is used to examine the possibility of achieving quasi-steady detonation phenomena in nuclear reactor containment buildings during postulated core-melt accidents

  15. On the deflagration-to-detonation transition (DDT) process with added energetic solid particles for pulse detonation engines (PDE)

    Science.gov (United States)

    Nguyen, V. B.; Li, J.; Chang, P.-H.; Phan, Q. T.; Teo, C. J.; Khoo, B. C.

    2018-01-01

    In this paper, numerical simulations are performed to study the dynamics of the deflagration-to-detonation transition (DDT) in pulse detonation engines (PDE) using energetic aluminum particles. The DDT process and detonation wave propagation toward the unburnt hydrogen/air mixture containing solid aluminum particles is numerically studied using the Eulerian-Lagrangian approach. A hybrid numerical methodology combined with appropriate sub-models is used to capture the gas dynamic characteristics, particle behavior, combustion characteristics, and two-way solid-particle-gas flow interactions. In our approach, the gas mixture is expressed in the Eulerian frame of reference, while the solid aluminum particles are tracked in the Lagrangian frame of reference. The implemented computer code is validated using published benchmark problems. The obtained results show that the aluminum particles not only shorten the DDT length but also reduce the DDT time. The improvement of DDT is primarily attributed to the heat released from surface chemical reactions on the aluminum particles. The temperatures associated with the DDT process are greater than the case of non-reacting particles added, with an accompanying rise in the pressure. For an appropriate range of particle volume fraction, particularly in this study, the higher volume fraction of the micro-aluminum particles added in the detonation chamber can lead to more heat energy released and more local instabilities in the combustion process (caused by the local high temperature), thereby resulting in a faster DDT process. In essence, the aluminum particles contribute to the DDT process of successfully transitioning to detonation waves for (failure) cases in which the fuel gas mixture can be either too lean or too rich. With a better understanding of the influence of added aluminum particles on the dynamics of the DDT and detonation process, we can apply it to modify the geometry of the detonation chamber (e.g., the length of

  16. Benign fibrous histiocytoma of the lumbar vertebrae

    International Nuclear Information System (INIS)

    Demiralp, Bahtiyar; Oguz, Erbil; Sehirlioglu, Ali; Kose, Ozkan; Sanal, Tuba; Ozcan, Ayhan

    2009-01-01

    Benign fibrous histiocytoma is an extremely rare spinal tumor with ten reported cases in the literature. Benign fibrous histiocytoma constitutes a diagnostic challenge because it shares common clinical symptoms, radiological characteristics, and histological features with other benign lesions involving the spine. We present a case of benign fibrous histiocytoma of the lumbar spine and discuss its differential diagnosis and management. (orig.)

  17. Benign mixed tumor of the lacrimal sac

    Directory of Open Access Journals (Sweden)

    Jong-Suk Lee

    2015-01-01

    Full Text Available Neoplasms of the lacrimal drainage system are uncommon, but potentially life-threatening and are often difficult to diagnose. Among primary lacrimal sac tumors, benign mixed tumors are extremely rare. Histologically, benign mixed tumors have been classified as a type of benign epithelial tumor. Here we report a case of benign mixed tumor of the lacrimal sac.

  18. Radical pancreaticoduodenectomy for benign disease.

    LENUS (Irish Health Repository)

    Kavanagh, D O

    2008-01-01

    Whipple\\'s procedure is the treatment of choice for pancreatic and periampullary malignancies. Preoperative histological confirmation of malignancy is frequently unavailable and some patients will subsequently be found to have benign disease. Here, we review our experience with Whipple\\'s procedure for patients ultimately proven to have benign disease. The medical records of all patients who underwent Whipple\\'s procedure during a 15-year period (1987-2002) were reviewed; 112 patients underwent the procedure for suspected malignancy. In eight cases, the final histology was benign (7.1%). One additional patient was known to have benign disease at resection. The mean age was 50 years (range: 30-75). The major presenting features included jaundice (five), pain (two), gastric outlet obstruction (one), and recurrent gastrointestinal haemorrhage (one). Investigations included ultrasound (eight), computerised tomography (eight), endoscopic retrograde cholangiopancreatography (seven; of these, four patients had a stent inserted and three patients had sampling for cytology), and endoscopic ultrasound (two). The pathological diagnosis included benign biliary stricture (two), chronic pancreatitis (two), choledochal cyst (one), inflammatory pseudotumour (one), cystic duodenal wall dysplasia (one), duodenal angiodysplasia (one), and granular cell neoplasm (one). There was no operative mortality. Morbidity included intra-abdominal collection (one), anastomotic leak (one), liver abscess (one), and myocardial infarction (one). All patients remain alive and well at mean follow-up of 41 months. Despite recent advances in diagnostic imaging, 8% of the patients undergoing Whipple\\'s procedure had benign disease. A range of unusual pathological entities can mimic malignancy. Accurate preoperative histological diagnosis may have allowed a less radical operation to be performed. Endoscopic ultrasound-guided fine needle aspirate (EUS-FNA) may reduce the need for Whipple\\'s operation

  19. Radical Pancreaticoduodenectomy for Benign Disease

    Directory of Open Access Journals (Sweden)

    D. O. Kavanagh

    2008-01-01

    Full Text Available Whipple's procedure is the treatment of choice for pancreatic and periampullary malignancies. Preoperative histological confirmation of malignancy is frequently unavailable and some patients will subsequently be found to have benign disease. Here, we review our experience with Whipple's procedure for patients ultimately proven to have benign disease. The medical records of all patients who underwent Whipple's procedure during a 15-year period (1987–2002 were reviewed; 112 patients underwent the procedure for suspected malignancy. In eight cases, the final histology was benign (7.1%. One additional patient was known to have benign disease at resection. The mean age was 50 years (range: 30–75. The major presenting features included jaundice (five, pain (two, gastric outlet obstruction (one, and recurrent gastrointestinal haemorrhage (one. Investigations included ultrasound (eight, computerised tomography (eight, endoscopic retrograde cholangiopancreatography (seven; of these, four patients had a stent inserted and three patients had sampling for cytology, and endoscopic ultrasound (two. The pathological diagnosis included benign biliary stricture (two, chronic pancreatitis (two, choledochal cyst (one, inflammatory pseudotumour (one, cystic duodenal wall dysplasia (one, duodenal angiodysplasia (one, and granular cell neoplasm (one. There was no operative mortality. Morbidity included intra-abdominal collection (one, anastomotic leak (one, liver abscess (one, and myocardial infarction (one. All patients remain alive and well at mean follow-up of 41 months. Despite recent advances in diagnostic imaging, 8% of the patients undergoing Whipple'’s procedure had benign disease. A range of unusual pathological entities can mimic malignancy. Accurate preoperative histological diagnosis may have allowed a less radical operation to be performed. Endoscopic ultrasound–guided fine needle aspirate (EUS-FNA may reduce the need for Whipple's operation in

  20. Propagation of Axially Symmetric Detonation Waves

    Energy Technology Data Exchange (ETDEWEB)

    Druce, R L; Roeske, F; Souers, P C; Tarver, C M; Chow, C T S; Lee, R S; McGuire, E M; Overturf, G E; Vitello, P A

    2002-06-26

    We have studied the non-ideal propagation of detonation waves in LX-10 and in the insensitive explosive TATB. Explosively-driven, 5.8-mm-diameter, 0.125-mm-thick aluminum flyer plates were used to initiate 38-mm-diameter, hemispherical samples of LX-10 pressed to a density of 1.86 g/cm{sup 3} and of TATB at a density of 1.80 g/cm{sup 3}. The TATB powder was a grade called ultrafine (UFTATB), having an arithmetic mean particle diameter of about 8-10 {micro}m and a specific surface area of about 4.5 m{sup 2}/g. Using PMMA as a transducer, output pressure was measured at 5 discrete points on the booster using a Fabry-Perot velocimeter. Breakout time was measured on a line across the booster with a streak camera. Each of the experimental geometries was calculated using the Ignition and Growth Reactive Flow Model, the JWL++ Model and the Programmed Burn Model. Boosters at both ambient and cold (-20 C and -54 C) temperatures have been experimentally and computationally studied. A comparison of experimental and modeling results is presented.

  1. Deflagration to detonation experiments in granular HMX

    Energy Technology Data Exchange (ETDEWEB)

    Burnside, N.J.; Son, S.F.; Asay, B.W.; Dickson, P.M.

    1998-03-01

    In this paper the authors report on continuing work involving a series of deflagration-to-detonation transition (DDT) experiments in which they study the piston-initiated DDT of heavily confined granular cyclotetramethylenetetranitramine (HMX). These experiments were designed to he useful in model development and evaluation. A main focus of these experiments is the effect of density on the DDT event. Particle size distribution and morphology are carefully characterized. In this paper they present recent surface area analysis. Earlier studies demonstrated extensive fracturing and agglomeration in samples at densities as low as 75% TMD as evidenced by dramatic decreases in particle size distribution due to mild stimulus. This is qualitatively confirmed with SEM images and quantitatively studied with gas absorption surface area analysis. Also, in this paper they present initial results using a microwave interferometer technique. Dynamic calibration of the technique was performed, a 35 GHz signal is used to increase resolution, and the system has been designed to be inexpensive for repeated experiments. The distance to where deformation of the inner wall begins for various densities is reported. This result is compared with the microwave interferometer measurements.

  2. Reducing the Consequences of a Nuclear Detonation.

    Energy Technology Data Exchange (ETDEWEB)

    Buddemeier, B R

    2007-11-09

    The 2002 National Strategy to Combat Weapons of Mass Destruction states that 'the United States must be prepared to respond to the use of WMD against our citizens, our military forces, and those of friends and allies'. Scenario No.1 of the 15 Department of Homeland Security national planning scenarios is an improvised nuclear detonation in the national capitol region. An effective response involves managing large-scale incident response, mass casualty, mass evacuation, and mass decontamination issues. Preparedness planning activities based on this scenario provided difficult challenges in time critical decision making and managing a large number of casualties within the hazard area. Perhaps even more challenging is the need to coordinate a large scale response across multiple jurisdictions and effectively responding with limited infrastructure and resources. Federal response planning continues to make improvements in coordination and recommending protective actions, but much work remains. The most critical life-saving activity depends on actions taken in the first few minutes and hours of an event. The most effective way to reduce the enormous national and international social and economic disruptions from a domestic nuclear explosion is through planning and rapid action, from the individual to the federal response. Anticipating response resources for survivors based on predicted types and distributions of injuries needs to be addressed.

  3. Effects of injection nozzle exit width on rotating detonation engine

    Science.gov (United States)

    Sun, Jian; Zhou, Jin; Liu, Shijie; Lin, Zhiyong; Cai, Jianhua

    2017-11-01

    A series of numerical simulations of RDE modeling real injection nozzles with different exit widths are performed in this paper. The effects of nozzle exit width on chamber inlet state, plenum flowfield and detonation propagation are analyzed. The results are compared with that using an ideal injection model. Although the ideal injection model is a good approximation method to model RDE inlet, the two-dimensional effects of real nozzles are ignored in the ideal injection model so that some complicated phenomena such as the reflected waves caused by the nozzle walls and the reversed flow into the nozzles can not be modeled accurately. Additionally, the ideal injection model overpredicts the block ratio. In all the cases that stabilize at one-wave mode, the block ratio increases as the nozzle exit width gets smaller. The dual-wave mode case also has a relatively high block ratio. A pressure oscillation in the plenum with the same main frequency with the rotating detonation wave is observed. A parameter σ is applied to describe the non-uniformity in the plenum. σ increases as the nozzle exit width gets larger. Under some condition, the heat release on the interface of fresh premixed gas layer and detonation products can be strong enough to induce a new detonation wave. A spontaneous mode-transition process is observed for the smallest exit width case. Due to the detonation products existing in the premixed gas layer before the detonation wave, the detonation wave will propagate through reactants and products alternately, and therefore its strength will vary with time, especially near the chamber inlet. This tendency gets weaker as the injection nozzle exit width increases.

  4. Dynamic stabbing queries with sub-logarithmic local updates for overlapping intervals : Proc. 12th International Computer Science Symposium in Russia

    NARCIS (Netherlands)

    Khramtcova, Elena; Löffler, Maarten

    2017-01-01

    We present a data structure to maintain a set of intervals on the real line subject to fast insertions and deletions of the intervals, stabbing queries, and local updates. Intuitively, a local update replaces an interval by another one of roughly the same size and location. We investigate whether

  5. The development of laser ignited deflagration-to-detonation transition (DDT) detonators and pyrotechnic actuators

    Energy Technology Data Exchange (ETDEWEB)

    Merson, J.A.; Salas, F.J.; Harlan, J.G.

    1993-11-01

    The use of laser ignited explosive components has been recognized as a safety enhancement over existing electrical explosive devices (EEDs). Sandia has been pursuing the development of optical ordnance for many years with recent emphasis on developing optical deflagration-to-detonation (DDT) detonators and pyrotechnic actuators. These low energy optical ordnance devices can be ignited with either a semiconductor diode laser, laser diode arrays or a solid state rod laser. By using a semiconductor laser diode, the safety improvement can be made without sacrificing performance since the input energy required for the laser diode and the explosive output are similar to existing electrical systems. The use of higher powered laser diode arrays or rod lasers may have advantages in fast DDT applications or lossy optical environments such as long fiber applications and applications with numerous optical connectors. Recent results from our continued study of optical ignition of explosive and pyrotechnic materials are presented. These areas of investigation can be separated into three different margin categories: (1) the margin relative to intended inputs (i.e. powder performance as a function of laser input variation), (2) the margin relative to anticipated environments (i.e. powder performance as a function of thermal environment variation), and (3) the margin relative to unintended environments (i.e. responses to abnormal environments or safety).

  6. Mesotherapy for benign symmetric lipomatosis.

    Science.gov (United States)

    Hasegawa, Toshio; Matsukura, Tomoyuki; Ikeda, Shigaku

    2010-04-01

    Benign symmetric lipomatosis, also known as Madelung disease, is a rare disorder characterized by fat distribution around the shoulders, arms, and neck in the context of chronic alcoholism. Complete excision of nonencapsulated lipomas is difficult. However, reports describing conservative therapeutic measures for lipomatosis are rare. The authors present the case of a 42-year-old man with a diagnosis of benign symmetric lipomatosis who had multiple, large, symmetrical masses in his neck. Multiple phosphatidylcholine injections in the neck were administered 4 weeks apart, a total of seven times to achieve lipolysis. The patient's lipomatosis improved in response to the injections, and he achieved good cosmetic results. Intralesional injection, termed mesotherapy, using phosphatidylcholine is a potentially effective therapy for benign symmetric lipomatosis that should be reconsidered as a therapeutic option for this disease.

  7. Mechanisms of detonation formation due to a temperature gradient

    Science.gov (United States)

    Kapila, A. K.; Schwendeman, D. W.; Quirk, J. J.; Hawa, T.

    2002-12-01

    Emergence of a detonation in a homogeneous, exothermically reacting medium can be deemed to occur in two phases. The first phase processes the medium so as to create conditions ripe for the onset of detonation. The actual events leading up to preconditioning may vary from one experiment to the next, but typically, at the end of this stage the medium is hot and in a state of nonuniformity. The second phase consists of the actual formation of the detonation wave via chemico-gasdynamic interactions. This paper considers an idealized medium with simple, rate-sensitive kinetics for which the preconditioned state is modelled as one with an initially prescribed linear gradient of temperature. Accurate and well-resolved numerical computations are carrried out to determine the mode of detonation formation as a function of the size of the initial gradient. For shallow gradients, the result is a decelerating supersonic reaction wave, a weak detonation, whose trajectory is dictated by the initial temperature profile, with only weak intervention from hydrodynamics. If the domain is long enough, or the gradient less shallow, the wave slows down to the Chapman-Jouguet speed and undergoes a swift transition to the ZND structure. For sharp gradients, gasdynamic nonlinearity plays a much stronger role. Now the path to detonation is through an accelerating pulse that runs ahead of the reaction wave and rearranges the induction-time distribution there to one that bears little resemblance to that corresponding to the initial temperature gradient. The pulse amplifies and steepens, transforming itself into a complex consisting of a lead shock, an induction zone, and a following fast deflagration. As the pulse advances, its three constituent entities attain progressively higher levels of mutual coherence, to emerge as a ZND detonation. For initial gradients that are intermediate in size, aspects of both the extreme scenarios appear in the path to detonation. The novel aspect of this study

  8. Toward a microscopic theory of detonations in energetic crystals

    International Nuclear Information System (INIS)

    Peyrard, M.; Odiot, S.

    1991-01-01

    Investigations of microscopic structure of detonation waves are useful for extending our basic understanding of the solid state. In a detonation wave, a crystal cell can be compressed to one-half of its equilibrium size. As a result, detonations probe regions of the atom-atom interaction potential curves that can hardly be investigated by any other means. In this paper the authors describe the first investigations of energetic materials after discussing briefly the molecular dynamics techniques themselves and presenting their application to shock waves in solids. We then focus on two particular topics in which molecular dynamics has brought new insights to the propagation of a detonation wave in a crystal, the role of the crystal structure, and the effects of the different steps in the chemistry. Section V presents a new approach that combines a model for the chemistry with standard molecular dynamics techniques, an approach that extends the domain of investigation of the numerical simulations and provides a step toward a microscopic theory of the propagation of a detonation wave. Section VI discusses the results and the future of these approaches

  9. The development and testing of pulsed detonation engine ground demonstrators

    Science.gov (United States)

    Panicker, Philip Koshy

    2008-10-01

    The successful implementation of a PDE running on fuel and air mixtures will require fast-acting fuel-air injection and mixing techniques, detonation initiation techniques such as DDT enhancing devices or a pre-detonator, an effective ignition system that can sustain repeated firing at high rates and a fast and capable, closed-loop control system. The control system requires high-speed transducers for real-time monitoring of the PDE and the detection of the detonation wave speed. It is widely accepted that the detonation properties predicted by C-J detonation relations are fairly accurate in comparison to experimental values. The post-detonation flow properties can also be expressed as a function of wave speed or Mach number. Therefore, the PDE control system can use C-J relations to predict the post-detonation flow properties based on measured initial conditions and compare the values with those obtained from using the wave speed. The controller can then vary the initial conditions within the combustor for the subsequent cycle, by modulating the frequency and duty cycle of the valves, to obtain optimum air and fuel flow rates, as well as modulate the energy and timing of the ignition to achieve the required detonation properties. Five different PDE ground demonstrators were designed, built and tested to study a number of the required sub-systems. This work presents a review of all the systems that were tested, along with suggestions for their improvement. The PDE setups, ranged from a compact PDE with a 19 mm (3/4 in.) i.d., to two 25 mm (1 in.) i.d. setups, to a 101 mm (4 in.) i.d. dual-stage PDE setup with a pre-detonator. Propane-oxygen mixtures were used in the smaller PDEs. In the dual-stage PDE, propane-oxygen was used in the pre-detonator, while propane-air mixtures were used in the main combustor. Both rotary valves and solenoid valve injectors were studied. The rotary valves setups were tested at 10 Hz, while the solenoid valves were tested at up to 30 Hz

  10. Investigations on detonation shock dynamics and related topics. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Stewart, D.S. [Univ. of Illinois, Urbana, IL (United States). Dept. of Theoretical and Applied Mechanics

    1993-11-01

    This document is a final report that summarizes the research findings and research activities supported by the subcontract DOE-LANL-9-XG8-3931P-1 between the University of Illinois (D. S. Stewart Principal Investigator) and the University of California (Los Alamos National Laboratory, M-Division). The main focus of the work has been on investigations of Detonation Shock Dynamics. A second emphasis has been on modeling compaction of energetic materials and deflagration to detonation in those materials. The work has led to a number of extensions of the theory of Detonation Shock Dynamics (DSD) and its application as an engineering design method for high explosive systems. The work also enhanced the hydrocode capabilities of researchers in M-Division by modifications to CAVEAT, an existing Los Alamos hydrocode. Linear stability studies of detonation flows were carried out for the purpose of code verification. This work also broadened the existing theory for detonation. The work in this contract has led to the development of one-phase models for dynamic compaction of porous energetic materials and laid the groundwork for subsequent studies. Some work that modeled the discrete heterogeneous behavior of propellant beds was also performed. The contract supported the efforts of D. S. Stewart and a Postdoctoral student H. I. Lee at the University of Illinois.

  11. PULSATING REVERSE DETONATION MODELS OF TYPE Ia SUPERNOVAE. II. EXPLOSION

    International Nuclear Information System (INIS)

    Bravo, Eduardo; Garcia-Senz, Domingo; Cabezon, Ruben M.; DomInguez, Inmaculada

    2009-01-01

    Observational evidences point to a common explosion mechanism of Type Ia supernovae based on a delayed detonation of a white dwarf (WD). However, all attempts to find a convincing ignition mechanism based on a delayed detonation in a destabilized, expanding, white dwarf have been elusive so far. One of the possibilities that has been invoked is that an inefficient deflagration leads to pulsation of a Chandrasekhar-mass WD, followed by formation of an accretion shock that confines a carbon-oxygen rich core, while transforming the kinetic energy of the collapsing halo into thermal energy of the core, until an inward moving detonation is formed. This chain of events has been termed Pulsating Reverse Detonation (PRD). In this work, we present three-dimensional numerical simulations of PRD models from the time of detonation initiation up to homologous expansion. Different models characterized by the amount of mass burned during the deflagration phase, M defl , give explosions spanning a range of kinetic energies, K ∼ (1.0-1.2) x 10 51 erg, and 56 Ni masses, M( 56 Ni) ∼ 0.6-0.8 M sun , which are compatible with what is expected for typical Type Ia supernovae. Spectra and light curves of angle-averaged spherically symmetric versions of the PRD models are discussed. Type Ia supernova spectra pose the most stringent requirements on PRD models.

  12. Detonation Synthesis of Alpha-Variant Silicon Carbide

    Science.gov (United States)

    Langenderfer, Martin; Johnson, Catherine; Fahrenholtz, William; Mochalin, Vadym

    2017-06-01

    A recent research study has been undertaken to develop facilities for conducting detonation synthesis of nanomaterials. This process involves a familiar technique that has been utilized for the industrial synthesis of nanodiamonds. Developments through this study have allowed for experimentation with the concept of modifying explosive compositions to induce synthesis of new nanomaterials. Initial experimentation has been conducted with the end goal being synthesis of alpha variant silicon carbide (α-SiC) in the nano-scale. The α-SiC that can be produced through detonation synthesis methods is critical to the ceramics industry because of a number of unique properties of the material. Conventional synthesis of α-SiC results in formation of crystals greater than 100 nm in diameter, outside nano-scale. It has been theorized that the high temperature and pressure of an explosive detonation can be used for the formation of α-SiC in the sub 100 nm range. This paper will discuss in detail the process development for detonation nanomaterial synthesis facilities, optimization of explosive charge parameters to maximize nanomaterial yield, and introduction of silicon to the detonation reaction environment to achieve first synthesis of nano-sized alpha variant silicon carbide.

  13. Benign fibroushistiocytoma of the gingiva

    Directory of Open Access Journals (Sweden)

    Palani Rajathi

    2013-01-01

    Full Text Available Benign fibroushistiocytoma is a benign connective tissue tumor rarely seen affecting the head and neck region. These tumors were believed to be of histiocytic origin as they are comprised of cells, which showed spindled morphology and cells with a round histiocytic appearance. The current concept consents that the lesional cells rather represent a fibroblastic differentiation. Diagnosis of these tumors proves to be challenging even with the use of immunohistochemistry due to lack of any specific markers. Here, we describe a case which presented in the gingiva mimicking a reactive lesion, which in fact was a tumor.

  14. Effect of detonation nanodiamonds on phagocyte activity.

    Science.gov (United States)

    Karpukhin, Alexey V; Avkhacheva, Nadezhda V; Yakovlev, Ruslan Yu; Kulakova, Inna I; Yashin, Valeriy A; Lisichkin, Georgiy V; Safronova, Valentina G

    2011-07-01

    Detonation ND (nanodiamond) holds much promise for biological studies and medical applications. Properties like size of particles, inclination for modification of their surface and unambiguous biocompatibility are crucial. Of prime importance is interaction between ND and immune cells, which supervise foreign intrusion into an organism and eliminate it. Neutrophils are more reactive in inflammatory response implementing cytotoxical arsenal including ROS (reactive oxygen species). The aim of the work was to estimate the ability of two ND samples (produced by Diamond Center and PlasmaChem) to keep the vitality of neutrophils from the inflammatory site. The ability of cells to generate ROS in the presence of ND particles is considered as indicating their biocompatibility. IR spectra and size of particles in the samples were characterized. Acid modification of ND was carried out to get the luminescent form. In the biological aspect, ND demonstrated up or down action, depending on the concentration, time and conditions of activation of cells. Weak action of ND in whole blood was obtained possibly owing to the ND adsorbed plasma proteins, which mask active functional groups to interact with the cell membrane. ND did not influence the viability of isolated inflammatory neutrophils in low and moderate concentrations and suppressed it in high concentrations (≥1 g/l). Addition of ND to the cell suspension initiated concentration-dependent reaction to produce ROS similar to respiratory burst. ND up-regulated response to bacterial formylpeptide, but up- and down-modified (low or high concentrations, accordingly) response to such bacterial agents as OZ (opsonized zymosan), which neutrophils swallow up by oxygen-dependent phagocytosis. Localization of the particles on the cell surface as into the cells was identified by monitoring the intrinsic fluorescence of oxidized ND. The various mechanisms that could account for penetration of ND particles into the cell are discussed

  15. Unsteady Specific Work and Isentropic Efficiency of a Radial Turbine Driven by Pulsed Detonations

    Science.gov (United States)

    2012-06-14

    rotating detonation combustor RDE = rotating detonation engine SDC = steady deflagration combustor SiC = silicon carbide TDLAS = tunable diode...rotating detonation engine ( RDE ) configuration, illustrated in Fig. 80, has been proposed as an alternative to the axial pulsed detonation tube...arrangement (Bykovskii, et al. 2006; Daniau, et al. 2005; Hayashi, et al. 2009). The RDE contains an annular duct with one open end for exhausting

  16. Thermal stability of detonation-produced micro and nanodiamonds

    Science.gov (United States)

    Efremov, V. P.; Zakatilova, E. I.; Maklashova, I. V.; Shevchenko, N. V.

    2018-01-01

    Detonation nanodiamonds are produced at utilization of high explosives. When an explosive blasts in a water environment, the detonation products contain microdiamonds, and in a gaseous medium, nanodiamonds. It is known that with decreasing size the influence of the surface energy of particles on their properties increases. Thus, it is interesting to compare the properties of detonation nano and microdiamonds. In this study, we have examined the thermal stability of diamond materials by synchronous thermal analysis. The experiments were performed at atmospheric pressure in argon flow for different heating rates in a range from room temperature to 1500 °C. Samples of initial and annealed micro and nanomaterials were studied using electron microscopy, x-ray and x-ray-fluorescence analysis. It was established that thermal and structural properties of micro and nanodiamonds differ substantially.

  17. Simulating sympathetic detonation using the hydrodynamic models and constitutive equations

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Bo Hoon; Kim, Min Sung; Yoh, Jack J. [Dept. of Mechanical and Aerospace Engineering, Seoul National University, Seoul (Korea, Republic of); Sun, Tae Boo [Hanwha Corporation Defense Rand D Center, Daejeon (Korea, Republic of)

    2016-12-15

    A Sympathetic detonation (SD) is a detonation of an explosive charge by a nearby explosion. Most of times it is unintended while the impact of blast fragments or strong shock waves from the initiating donor explosive is the cause of SD. We investigate the SD of a cylindrical explosive charge (64 % RDX, 20 % Al, 16 % HTPB) contained in a steel casing. The constitutive relations for high explosive are obtained from a thermo-chemical code that provides the size effect data without the rate stick data typically used for building the rate law and equation of state. A full size SD test of eight pallet-packaged artillery shells is performed that provides the pressure data while the hydrodynamic model with proper constitutive relations for reactive materials and the fragmentation model for steel casing is conducted to replicate the experimental findings. The work presents a novel effort to accurately model and reproduce the sympathetic detonation event with a reduced experimental effort.

  18. The analysis of thermal stability of detonation nanodiamond

    International Nuclear Information System (INIS)

    Efremov, V P; Zakatilova, E I

    2016-01-01

    The detonation nanodiamond is a new perspective material. Ammunition recycling with use of high explosives and obtaining nanodiamond as the result of the detonation synthesis have given a new motivation for searching of their application areas. In this work nanodiamond powder has been investigated by the method of synchronous thermal analysis. Experiments have been carried out at atmospheric pressure in the environment of argon. Nanodiamond powder has been heated in the closed corundum crucible at the temperature range of 30-1500 °C. The heating rates were varied from 2 K/min to 20 K/min. After the heat treatment, the samples have been studied by the x-ray diffraction and the electron microscopy. As one of the results of this work, it has been found that the detonation nanodiamond has not started the transition into graphite at the temperature below 800 °C. (paper)

  19. Rotary wave-ejector enhanced pulse detonation engine

    Science.gov (United States)

    Nalim, M. R.; Izzy, Z. A.; Akbari, P.

    2012-01-01

    The use of a non-steady ejector based on wave rotor technology is modeled for pulse detonation engine performance improvement and for compatibility with turbomachinery components in hybrid propulsion systems. The rotary wave ejector device integrates a pulse detonation process with an efficient momentum transfer process in specially shaped channels of a single wave-rotor component. In this paper, a quasi-one-dimensional numerical model is developed to help design the basic geometry and operating parameters of the device. The unsteady combustion and flow processes are simulated and compared with a baseline PDE without ejector enhancement. A preliminary performance assessment is presented for the wave ejector configuration, considering the effect of key geometric parameters, which are selected for high specific impulse. It is shown that the rotary wave ejector concept has significant potential for thrust augmentation relative to a basic pulse detonation engine.

  20. The analysis of thermal stability of detonation nanodiamond

    Science.gov (United States)

    Efremov, V. P.; Zakatilova, E. I.

    2016-11-01

    The detonation nanodiamond is a new perspective material. Ammunition recycling with use of high explosives and obtaining nanodiamond as the result of the detonation synthesis have given a new motivation for searching of their application areas. In this work nanodiamond powder has been investigated by the method of synchronous thermal analysis. Experiments have been carried out at atmospheric pressure in the environment of argon. Nanodiamond powder has been heated in the closed corundum crucible at the temperature range of 30-1500 °C. The heating rates were varied from 2 K/min to 20 K/min. After the heat treatment, the samples have been studied by the x-ray diffraction and the electron microscopy. As one of the results of this work, it has been found that the detonation nanodiamond has not started the transition into graphite at the temperature below 800 °C.

  1. Benign paroxysmal positional vertigo treatment

    DEFF Research Database (Denmark)

    West, Niels; Hansen, Søren; Bloch, Sune Land

    2017-01-01

    Benign paroxysmal positional vertigo (BPPV) remains the most frequent cause of vertigo. The TRV chair is a mechanical device suited for optimization of managing complex cases of BPPV. Although the use of repositioning devices in the management of BPPV is increasing, no applicable guide for the TRV...

  2. Spectrum of benign breast diseases

    International Nuclear Information System (INIS)

    Khanzada, T.W.; Samad, A.; Sushel, C.

    2009-01-01

    Objective: To determine the frequencies of various benign breast diseases (BBD) in female patients in three private hospitals of Hyderabad. Methodology: This is a prospective cohort study of all female patients visiting the surgical clinic with breast problems. This study was conducted at Isra University Hospital Hyderabad and two other private hospitals of Hyderabad over a period of about three years starting from March 2004 to February 2007. All female patients visiting the surgical clinic with breast problems were included in the study. Patients with obvious clinical features of malignancy or those who on work up were diagnosed as carcinoma were excluded from the study. Results: A total of 275 patients were included in the study. About 44% (120/275) patients belonged to third decade of life (age between: 21-30 years) followed by 33% from forth decade (age between: 31- 40 years). Fibroadenoma was the most common benign breast disease, seen in 27% (75/275) of patients, followed by fibrocystic disease seen in about 21% (57/275) patients. Conclusion: Benign Breast Diseases (BBD) are common problems in females of reproductive age. Fibroadenoma is the commonest of all benign breast disease in our set up mostly seen in second and third decade of life. Fibrocystic disease of the breast is the next common BBD whose incidence increases with increasing age. (author)

  3. Numerical modeling of the deflagration-to-detonation transition

    International Nuclear Information System (INIS)

    Forest, C.A.

    1978-01-01

    The effect of a confined porous bed of burning explosive in contact with a solid explosive is studied by computer simulation. The burning is modeled using a bulk burn model that is a function of the surface area and the pressure. Once pressure excursions occur from the confined burning the transition to detonation is modeled using a pressure-dependent heterogeneous explosive shock decomposition model called Forest Fire. The occurrence of detonation in the solid explosive is shown to be dependent upon the surface-to-volume ratio, the confinement of the porous bed, and the geometry of the system

  4. The equation of state of predominant detonation products

    Science.gov (United States)

    Zaug, Joseph; Crowhurst, Jonathan; Bastea, Sorin; Fried, Laurence

    2009-06-01

    The equation of state of detonation products, when incorporated into an experimentally grounded thermochemical reaction algorithm can be used to predict the performance of explosives. Here we report laser based Impulsive Stimulated Light Scattering measurements of the speed of sound from a variety of polar and nonpolar detonation product supercritical fluids and mixtures. The speed of sound data are used to improve the exponential-six potentials employed within the Cheetah thermochemical code. We will discuss the improvements made to Cheetah in terms of predictions vs. measured performance data for common polymer blended explosives. Accurately computing the chemistry that occurs from reacted binder materials is one important step forward in our efforts.

  5. Towards Integrated Pulse Detonation Propulsion and MHD Power

    Science.gov (United States)

    Litchford, Ron J.; Thompson, Bryan R.; Lineberry, John T.

    1999-01-01

    The interest in pulse detonation engines (PDE) arises primarily from the advantages that accrue from the significant combustion pressure rise that is developed in the detonation process. Conventional rocket engines, for example, must obtain all of their compression from the turbopumps, while the PDE provides additional compression in the combustor. Thus PDE's are expected to achieve higher I(sub sp) than conventional rocket engines and to require smaller turbopumps. The increase in I(sub sp) and the decrease in turbopump capacity must be traded off against each other. Additional advantages include the ability to vary thrust level by adjusting the firing rate rather than throttling the flow through injector elements. The common conclusion derived from these aggregated performance attributes is that PDEs should result in engines which are smaller, lower in cost, and lighter in weight than conventional engines. Unfortunately, the analysis of PDEs is highly complex due to their unsteady operation and non-ideal processes. Although the feasibility of the basic PDE concept has been proven in several experimental and theoretical efforts, the implied performance improvements have yet to be convincingly demonstrated. Also, there are certain developmental issues affecting the practical application of pulse detonation propulsion systems which are yet to be fully resolved. Practical detonation combustion engines, for example, require a repetitive cycle of charge induction, mixing, initiation/propagation of the detonation wave, and expulsion/scavenging of the combustion product gases. Clearly, the performance and power density of such a device depends upon the maximum rate at which this cycle can be successfully implemented. In addition, the electrical energy required for direct detonation initiation can be significant, and a means for direct electrical power production is needed to achieve self-sustained engine operation. This work addresses the technological issues associated

  6. Process Investigation of Tube Expansion by Gas Detonation

    OpenAIRE

    Bach, F.-W.; Beerwald, C.; Brosius, A.; Gershteyn, G.; Hermes, M.; Kleiner, M.; Olivier, H.; Weber, M.

    2006-01-01

    The present paper deals with the expansion of tubes by direct application of gas detonation waves, i.e. the gas is both pressure medium and energy source. After an introduction to gas detonation forming, measurements of the motion process and the internal pressures are presented. Results of free expansion and of forming into a die are thoroughly studied and compared to the results of quasi-static burst tests and hydroforming. Using pure aluminum Al99.5 and a medium strength alloy AlMgSi1, ...

  7. The ABC of benign breast disease

    African Journals Online (AJOL)

    Benign breast disease is common, although the incidence is sparsely documented in ... The clinical presentation of benign breast diseases includes one or more of the ... problem, with various terms such as mastodynia, mastitis and fibrocystic ...

  8. Diffuse benign gastric inflammatory hyperplastic polyps presenting ...

    African Journals Online (AJOL)

    Benign gastric inflammatory hyperplasic polyps are benign lesions that rarely occur in young age. We report a case of diffuse benign gastric inflammatory hyperplastic polyps in a 19 year old boy who presented with cough, nausea, and hematamesis. In the presented case symptoms such as nausea and vomiting are non ...

  9. Project Rio Blanco: detonation related activities. Final report

    International Nuclear Information System (INIS)

    1975-01-01

    Project Rio Blanco is described in relation to detonation, its history, execution, and results. Topics discussed include generalized site activities, emplacement well, explosive services and operations, operational safety, environmental protection program, seismic effects and damage claims, and add-on programs. (U.S.)

  10. HERMES: A Model to Describe Deformation, Burning, Explosion, and Detonation

    Energy Technology Data Exchange (ETDEWEB)

    Reaugh, J E

    2011-11-22

    HERMES (High Explosive Response to MEchanical Stimulus) was developed to fill the need for a model to describe an explosive response of the type described as BVR (Burn to Violent Response) or HEVR (High Explosive Violent Response). Characteristically this response leaves a substantial amount of explosive unconsumed, the time to reaction is long, and the peak pressure developed is low. In contrast, detonations characteristically consume all explosive present, the time to reaction is short, and peak pressures are high. However, most of the previous models to describe explosive response were models for detonation. The earliest models to describe the response of explosives to mechanical stimulus in computer simulations were applied to intentional detonation (performance) of nearly ideal explosives. In this case, an ideal explosive is one with a vanishingly small reaction zone. A detonation is supersonic with respect to the undetonated explosive (reactant). The reactant cannot respond to the pressure of the detonation before the detonation front arrives, so the precise compressibility of the reactant does not matter. Further, the mesh sizes that were practical for the computer resources then available were large with respect to the reaction zone. As a result, methods then used to model detonations, known as {beta}-burn or program burn, were not intended to resolve the structure of the reaction zone. Instead, these methods spread the detonation front over a few finite-difference zones, in the same spirit that artificial viscosity is used to spread the shock front in inert materials over a few finite-difference zones. These methods are still widely used when the structure of the reaction zone and the build-up to detonation are unimportant. Later detonation models resolved the reaction zone. These models were applied both to performance, particularly as it is affected by the size of the charge, and to situations in which the stimulus was less than that needed for reliable

  11. Criteria for transition to detonation for hydrogen flames

    International Nuclear Information System (INIS)

    Chan, C.K.

    1992-01-01

    During postulated loss-of-coolant accidents in a nuclear power reactor, the H 2 generated from a metal/steam reaction may leak into the containment building and form a combustible atmosphere. If the gas mixture is ignited, the potential damage to the containment building and equipment within the containment depends on whether the combustion is a deflagration or a detonation. Direct initiation of detonation requires a high-energy initiation source such as a solid explosive. Such a source is not likely to be present in a containment environment. However, a detonation can occur via a deflagration-to-detonation transition (DDT). At the present time, the necessary conditions (or the criteria) for a DDT to occur have not been determined. It is not possible to predict a priori whether a transition can occur in a given situation. Recently, a few qualitative methods were proposed to assess the likelihood of a DDT. This paper reviews the current understanding of the transition phenomenon, and discusses the qualitative methods available for assessing the likelihood of a DDT. It briefly describes a recent study on turbulent/flame interaction to establish one of the necessary conditions for a DDT to occur. A new methodology for assessing DDT is also proposed to remove some of the conservatism that prevails in the other approaches

  12. Detonation and combustion of explosives: A selected bibliography

    Energy Technology Data Exchange (ETDEWEB)

    Dobratz, B. [comp.

    1998-08-01

    This bibliography consists of citations pertinent to the subjects of combustion and detonation of energetic materials, especially, but not exclusively, of secondary solid high explosives. These references were selected from abstracting sources, conference proceedings, reviews, and also individual works. The entries are arranged alphabetically by first author and numbered sequentially. A keyword index is appended.

  13. Using embedded fibers to measure explosive detonation velocities

    Energy Technology Data Exchange (ETDEWEB)

    Podsednik, Jason W.; Parks, Shawn Michael; Navarro, Rudolfo J.

    2012-07-01

    Single-mode fibers were cleverly embedded into fixtures holding nitromethane, and used in conjunction with a photonic Doppler velocimeter (PDV) to measure the associated detonation velocity. These measurements have aided us in our understanding of energetic materials and enhanced our diagnostic capabilities.

  14. Study of a Model Equation in Detonation Theory

    KAUST Repository

    Faria, Luiz; Kasimov, Aslan R.; Rosales, Rodolfo R.

    2014-01-01

    Here we analyze properties of an equation that we previously proposed to model the dynamics of unstable detonation waves [A. R. Kasimov, L. M. Faria, and R. R. Rosales, Model for shock wave chaos, Phys. Rev. Lett., 110 (2013), 104104]. The equation

  15. Exhaust Gas Emissions from a Rotating Detonation-wave Engine

    Science.gov (United States)

    Kailasanath, Kazhikathra; Schwer, Douglas

    2015-11-01

    Rotating detonation-wave engines (RDE) are a form of continuous detonation-wave engines. They potentially provide further gains in performance than an intermittent or pulsed detonation-wave engine (PDE). The overall flow field in an idealized RDE, primarily consisting of two concentric cylinders, has been discussed in previous meetings. Because of the high pressures involved and the lack of adequate reaction mechanisms for this regime, previous simulations have typically used simplified chemistry models. However, understanding the exhaust species concentrations in propulsion devices is important for both performance considerations as well as estimating pollutant emissions. Progress towards addressing this need will be discussed in this talk. In this approach, an induction parameter model is used for simulating the detonation but a more detailed finite-chemistry model including NOx chemistry is used in the expansion flow region, where the pressures are lower and the uncertainties in the chemistry model are greatly reduced. Results show that overall radical concentrations in the exhaust flow are substantially lower than from earlier predictions with simplified models. The performance of a baseline hydrogen/air RDE increased from 4940 s to 5000 s with the expansion flow chemistry, due to recombination of radicals and more production of H2O, resulting in additional heat release. Work sponsored by the Office of Naval Research.

  16. 29 CFR 1926.908 - Use of detonating cord.

    Science.gov (United States)

    2010-07-01

    ... connectors or short-interval-delay electric blasting caps are used with detonating cord, the practice shall conform strictly to the manufacturer's recommendations. (i) When connecting a blasting cap or an electric... (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Blasting and the Use of Explosives § 1926.908 Use...

  17. Benign chondroblastoma - malignant radiological appearances

    Energy Technology Data Exchange (ETDEWEB)

    Schulze, K.; Treugut, H.; Mueller, G.E.

    1980-04-01

    The very rare benign chondroblastoma occasionally invades soft tissues and may grow beyond the epiphysis into the metaphysis. In the present case such a tumour did not show the typical radiological appearances, but presented malignant features both on plain films and on the angiogram. The importance of biopsy of tumours which cannot be identified with certainty must be stressed before radical surgery is carried out.

  18. Blue breath holding is benign.

    OpenAIRE

    Stephenson, J B

    1991-01-01

    In their recent publication in this journal, Southall et al described typical cyanotic breath holding spells, both in otherwise healthy children and in those with brainstem lesions and other malformations. Their suggestions regarding possible autonomic disturbances may require further study, but they have adduced no scientific evidence to contradict the accepted view that in the intact child blue breath holding spells are benign. Those families in which an infant suffers an 'apparently life t...

  19. Haemocompatibility Of Non-Functionalized And Plasmachemical Functionalized Detonation Nanodiamond Particles

    Directory of Open Access Journals (Sweden)

    Mitura K.

    2015-09-01

    Full Text Available The purpose of this paper is to present the innovative design of microwave plasma system for modification of detonation nanodiamond particles (DNP using a special rotating drum placed inside the reactor. Nanodiamond particles manufactured by detonation method reveal the biological activity depending on surface functionalization. Plasmachemical modification of detonation nanodiamond particles gives the possibility of controlling surface of nanodiamonds particles in biological tests. In this paper we would like to compare detonation nanodiamond (the grain sizes from 2 to 5 nm with modified detonation nanodiamond in rotary reactor chamber, by microwave plasma activated chemical vapour deposition (MW PACVD method in materials research (Raman and FT-IR spectroscopy and in vitro examinations with full of human blood. The results indicate haemocompatibility of non-modified detonation nanodiamond and modified nanodiamond by MW PACVD method in rotary reactor chamber (modified ND-3 and the presence of haemolysis in commercial detonation nanodiamond.

  20. Rapid detonation initiation by sparks in a short duct: a numerical study

    Science.gov (United States)

    Hu, Z. M.; Dou, H. S.; Khoo, B. C.

    2010-06-01

    Rapid onset of detonation can efficiently increase the working frequency of a pulse detonation engine (PDE). In the present study, computations of detonation initiation in a duct are conducted to investigate the mechanisms of detonation initiation. The governing equations are the Euler equations and the chemical kinetic model consists of 19 elementary reactions and nine species. Different techniques of initiation have been studied for the purpose of accelerating detonation onset with a relatively weak ignition energy. It is found that detonation ignition induced by means of multiple sparks is applicable to auto-ignition for a PDE. The interaction among shock waves, flame fronts and the strip of pre-compressed fresh (unburned) mixture plays an important role in rapid onset of detonation.

  1. [Recurrent benign cystic peritoneal mesothelioma].

    Science.gov (United States)

    Stroescu, C; Negulescu, Raluca; Herlea, V; David, L; Ivanov, B; Nitipir, Cornelia; Popescu, I

    2008-01-01

    The benign cystic peritoneal mesothelioma (BCPM) is a rare neoplasm affecting mainly females at reproductive age. The natural history and physiopathology of the BCPM are not entirely known. It is mainly characterized by the lack of malignant elements, no tendency to metastasis and by a pervasive tendency to generate local recurrences after surgical removal. The clinical manifestations are insidious, uncharacteristic; the benign cystic peritoneal mesothelioma is often discovered during a surgical procedure addressing another condition. Imaging tests can raise the suspicion of BCPM but the diagnostic can only be confirmed by histopathological examination corroborated with an immunohistochemical analysis. There are no long term studies dictating a single therapeutic attitude but a high risk of local recurrences and the possibility of transformation into malignant mesothelioma have lead to the current tendency towards an aggressive treatment of the tumor. We present the case of a recurrent benign cystic peritoneal mesothelioma in a 40 years old female patient, emphasizing the therapeutic approach and the role of radical surgery in the treatment of BPCM.

  2. Gas pollutants from detonation and combustion of industrial explosives

    Energy Technology Data Exchange (ETDEWEB)

    Campos, J.; Pines, A.; Gois, J.C.; Portugal, A. (University of Coimbra, Coimbra (Portugal). Mechanical Engineering Dept.)

    1993-01-01

    The potential hazards of fumes, from blasting operations in underground mines, have long been recognised. Beyond this normal use of explosives, there are also large amounts of energy substances which cannot be used because their life time is outdated or they are not within the minimal quality requirements. There is a lack of information concerning tests, procedures and theoretical predictions of pollutant concentrations in fumes from detonation and combustion operations with industrial explosives. The most common industrial explosives in Portugal are ammonium nitrate-fuel oil compositions (anfo), and dynamite. Recently, ammonium nitrate based emulsion explosives are more and more used in industrial applications. This paper presents the structure and fundamental thermodynamic equations of THOR computer code to calculate the combustion and detonation products (CO[sub 2], CO, H[sub 2]O, N[sub 2], O[sub 2], H[sub 2], OH, NO, H, N, O, HCN, NH[sub 3], NO[sub 2], N[sub 2]O, CH[sub 4] gases and two kinds of solid carbon - graphite and diamond) for the minimum value of Gibbs free energy, using three well known equations of state - BKW, H9 and H12. Detonation experiments are described and gas analysis discussed. Measured pollutants concentrations (CO, CO[sub 2], NO and NO[sub 2]), as a function of volume of explosion chamber, prove the dependence of expansion mechanisms on CO and NO formation and recombination and validate theoretical predictions. Incineration of explosives in a fluidised bed is described. Products composition from isobare adiabatic combustion of selected explosives has been calculated and correlated with previous calculations for a detonation regime. The obtained results demonstrate the possibility of predicting gas composition of detonation and combustion products of industrial explosives. 22 refs., 14 figs., 1 tab.

  3. The selective conservative management of small traumatic pneumothoraces following stab injuries is safe: experience from a high-volume trauma service in South Africa.

    Science.gov (United States)

    Kong, V Y; Oosthuizen, G V; Clarke, D L

    2015-02-01

    The selective conservative management of small pneumothoraces (PTXs) following stab injuries is controversial. We reviewed a cohort of patients managed conservatively in a high volume trauma service in South Africa. A retrospective review over a 2-year period identified 125 asymptomatic patients with small PTXs measuring chest radiograph who were managed conservatively. Of the 125 patients included in the study, 92% were male (115/125), and the median age for all patients was 21 years (19-24). Ninety-seven per cent (121/125) of the weapons involved were knives, and 3% (4/125) were screwdrivers. Sixty-one per cent of all injuries were on the left side. Eighty-two per cent (102/125) sustained a single stab, and 18% (23/125) had multiple stabs. Thirty-nine per cent (49/125) had a PTX <0.5 cm (Group A), 26% (32/125) were ≥ 0.5 to <1 cm (Group B), 19% (24/125) were ≥ 1 to <1.5 cm (Group C) and 15% (20/125) were ≥ 1.5 to <2 cm (Group D). Three per cent of all patients (4/125) eventually required ICDs (one in Group C, three in Group D). All four patients had ICDs in situ for 24 h. The remaining 97% (121/125) were all managed successfully by active clinical observation alone. There were no subsequent readmissions, morbidity or mortality as a direct result of our conservative approach. The selective conservative management of asymptomatic small PTXs from stab injuries is safe if undertaken in the appropriate setting.

  4. The stabbing of Amelia (or how was extinguished the married women discrimination from the argentinian telephone service

    Directory of Open Access Journals (Sweden)

    Dora Barrancos

    2008-04-01

    Full Text Available This paper highlights the tracks of Amelia C. Her life story as switchboard is relevant to understand the women' s discrimination in laboral market in the early twentieth century. This article will be focused on the marital satatus as pattern of female exclusion. The strategy used by Amelia against that pattern, although individual and even desperate, detonated a series of revisions of existing legislation that were supported by different groups in society. The corpus is based on records of the telephone company in which Amelia was employed for several years and the impact of their strategies in the local press.

  5. Comparison Of Flat-Knitted Structures Made Of Poly(P-Phenylene-2,6-Benzobisoxazole) And Para-Aramid Referring To Their Stab Resistance

    Science.gov (United States)

    Obermann, M.; Aumann, S.; Heimlich, F.; Weber, M. O.; Schwarz-Pfeiffer, A.

    2016-07-01

    In the field of protective gear, developers always aim for lighter and more flexible material in order to increase the wearing comfort. Suppliers now work on knitted garments in the sports-sector as well as in workwear and protective gear for policemen or security-agents. In a recent project different knitted structures made of a poly(p-phenylene-2,6-benzobisoxazole) (PBO)-multifilament were compared to their counterparts made of para-aramid. In focus of the comparison stood the stab-resistance linked to either the mass per unit area or the stitch density. The tested fabrics were produced on hand flat knitting machines as well as on electronical flat knitting machines of the type Stoll CMS 330TC4, in order to analyse fabrics with different tightness factor and machine gauges. The stab resistance of the different knitted fabrics was examined according to the standard of the Association of Test Laboratories for Bullet, Stab or Pike Resistant Materials and Construction Standards. The presentation includes the depiction of the results of the test series and their interpretation. Furthermore it will give an outlook on most suitable combinations of materials and structures to be used in protective gear.

  6. The direct cost of traumatic secretion transfer in hermaphroditic land snails: individuals stabbed with a love dart decrease lifetime fecundity.

    Science.gov (United States)

    Kimura, Kazuki; Chiba, Satoshi

    2015-04-07

    Several taxa of simultaneously hermaphroditic land snails exhibit a conspicuous mating behaviour, the so-called shooting of love darts. During mating, such land snail species transfer a specific secretion by stabbing a mating partner's body with the love dart. It has been shown that sperm donors benefit from this traumatic secretion transfer, because the secretions manipulate the physiology of a sperm recipient and increase the donors' fertilization success. However, it is unclear whether reception of dart shooting is costly to the recipients. Therefore, the effect of sexual conflict and antagonistic arms races on the evolution of traumatic secretion transfer in land snails is still controversial. To examine this effect, we compared lifetime fecundity and longevity between the individuals that received and did not receive dart shooting from mating partners in Bradybaena pellucida. Our experiments showed that the dart-receiving snails suffered reduction in lifetime fecundity and longevity. These results suggest that the costly mating behaviour, dart shooting, generates conflict between sperm donors and recipients and that sexually antagonistic arms races have contributed to the diversification of the morphological and behavioural traits relevant to dart shooting. Our findings also support theories suggesting a violent escalation of sexual conflict in hermaphroditic animals. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

  7. A Study of Detonation Propagation and Diffraction with Compliant Confinement

    Energy Technology Data Exchange (ETDEWEB)

    Banks, J; Schwendeman, D; Kapila, A; Henshaw, W

    2007-08-13

    A previous computational study of diffracting detonations with the ignition-and-growth model demonstrated that contrary to experimental observations, the computed solution did not exhibit dead zones. For a rigidly confined explosive it was found that while diffraction past a sharp corner did lead to a temporary separation of the lead shock from the reaction zone, the detonation re-established itself in due course and no pockets of unreacted material were left behind. The present investigation continues to focus on the potential for detonation failure within the ignition-and-growth (IG) model, but now for a compliant confinement of the explosive. The aim of the present paper is two fold. First, in order to compute solutions of the governing equations for multi-material reactive flow, a numerical method of solution is developed and discussed. The method is a Godunov-type, fractional-step scheme which incorporates an energy correction to suppress numerical oscillations that would occur near the material interface separating the reactive material and the inert confiner for standard conservative schemes. The numerical method uses adaptive mesh refinement (AMR) on overlapping grids, and the accuracy of solutions is well tested using a two-dimensional rate-stick problem for both strong and weak inert confinements. The second aim of the paper is to extend the previous computational study of the IG model by considering two related problems. In the first problem, the corner-turning configuration is re-examined, and it is shown that in the matter of detonation failure, the absence of rigid confinement does not affect the outcome in a material way; sustained dead zones continue to elude the model. In the second problem, detonations propagating down a compliantly confined pencil-shaped configuration are computed for a variety of cone angles of the tapered section. It is found, in accord with experimental observation, that if the cone angle is small enough, the detonation fails

  8. Development of a Gas-Fed Pulse Detonation Research Engine

    Science.gov (United States)

    Litchford, Ron J.; Hutt, John (Technical Monitor)

    2001-01-01

    In response to the growing need for empirical data on pulse detonation engine performance and operation, NASA Marshall Space Flight Center has developed and placed into operation a low-cost gas-fed pulse detonation research engine. The guiding design strategy was to achieve a simple and flexible research apparatus, which was inexpensive to build and operate. As such, the engine was designed to operate as a heat sink device, and testing was limited to burst-mode operation with run durations of a few seconds. Wherever possible, maximum use was made of standard off-the-shelf industrial or automotive components. The 5-cm diameter primary tube is about 90-cm long and has been outfitted with a multitude of sensor and optical ports. The primary tube is fed by a coaxial injector through an initiator tube, which is inserted directly into the injector head face. Four auxiliary coaxial injectors are also integrated into the injector head assembly. All propellant flow is controlled with industrial solenoid valves. An automotive electronic ignition system was adapted for use, and spark plugs are mounted in both tubes so that a variety of ignition schemes can be examined. A microprocessor-based fiber-optic engine control system was developed to provide precise control over valve and ignition timing. Initial shakedown testing with hydrogen/oxygen mixtures verified the need for Schelkin spirals in both the initiator and primary tubes to ensure rapid development of the detonation wave. Measured pressure wave time-of-flight indicated detonation velocities of 2.4 km/sec and 2.2 km/sec in the initiator and primary tubes, respectively. These values implied a fuel-lean mixture corresponding to an H2 volume fraction near 0.5. The axial distribution for the detonation velocity was found to be essentially constant along the primary tube. Time-resolved thrust profiles were also acquired for both underfilled and overfilled tube conditions. These profiles are consistent with previous time

  9. Benign Biliary Strictures and Leaks.

    Science.gov (United States)

    Devière, Jacques

    2015-10-01

    The major causes of benign biliary strictures include surgery, chronic pancreatitis, primary sclerosing cholangitis, and autoimmune cholangitis. Biliary leaks mainly occur after surgery and, rarely, abdominal trauma. These conditions may benefit from a nonsurgical approach in which endoscopic retrograde cholangiopancreatography (ERCP) plays a pivotal role in association with other minimally invasive approaches. This approach should be evaluated for any injury before deciding about the method for repair. ERCP, associated with peroral cholangioscopy, plays a growing role in characterizing undeterminate strictures, avoiding both unuseful major surgeries and palliative options that might compromise any further management. Copyright © 2015 Elsevier Inc. All rights reserved.

  10. Far Field Modeling Methods For Characterizing Surface Detonations

    Energy Technology Data Exchange (ETDEWEB)

    Garrett, A. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2015-10-08

    Savannah River National Laboratory (SRNL) analyzed particle samples collected during experiments that were designed to replicate tests of nuclear weapons components that involve detonation of high explosives (HE). SRNL collected the particle samples in the HE debris cloud using innovative rocket propelled samplers. SRNL used scanning electronic microscopy to determine the elemental constituents of the particles and their size distributions. Depleted uranium composed about 7% of the particle contents. SRNL used the particle size distributions and elemental composition to perform transport calculations that indicate in many terrains and atmospheric conditions the uranium bearing particles will be transported long distances downwind. This research established that HE tests specific to nuclear proliferation should be detectable at long downwind distances by sampling airborne particles created by the test detonations.

  11. Polar Coordinate Lattice Boltzmann Kinetic Modeling of Detonation Phenomena

    International Nuclear Information System (INIS)

    Lin Chuan-Dong; Li Ying-Jun; Xu Ai-Guo; Zhang Guang-Cai

    2014-01-01

    A novel polar coordinate lattice Boltzmann kinetic model for detonation phenomena is presented and applied to investigate typical implosion and explosion processes. In this model, the change of discrete distribution function due to local chemical reaction is dynamically coupled into the modified lattice Boltzmann equation which could recover the Navier—Stokes equations, including contribution of chemical reaction, via the Chapman—Enskog expansion. For the numerical investigations, the main focuses are the nonequilibrium behaviors in these processes. The system at the disc center is always in its thermodynamic equilibrium in the highly symmetric case. The internal kinetic energies in different degrees of freedom around the detonation front do not coincide. The dependence of the reaction rate on the pressure, influences of the shock strength and reaction rate on the departure amplitude of the system from its local thermodynamic equilibrium are probed. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)

  12. Effect of turbulence on deflagration to detonation transition

    International Nuclear Information System (INIS)

    Radford, D.D.; Chan, C.K.; Azad, R.S.

    1995-01-01

    The interaction of a turbulent jet and an expanding flame kernel was examined using spark-schlieren photography and piezoelectric pressure transducers. Experiments were performed in a 9 by 9 cm, 4-m-long shock channel. Results show that an expanding flame kernel can be locally, or partially, quenched by flame stretching. The mixing of the hot combustion products, containing reactive species, with the unburnt gas in the turbulent flame-jet, created pockets of sensitized mixture. The subsequent re-ignition of the sensitized mixture could result in a local explosion. In a number of experiments the blast waves produced in the local explosion developed into detonation waves. A local explosion occurred only if there was partial quenching of the flame kernel. Partial quenching occurs when the Karlovitz-Kovaszney factor approaches unity and, therefore, it is possible to establish a set of conditions in terms of turbulent parameters for the transition to detonation. (author). 16 refs., 13 figs

  13. Study of a Model Equation in Detonation Theory

    KAUST Repository

    Faria, Luiz

    2014-04-24

    Here we analyze properties of an equation that we previously proposed to model the dynamics of unstable detonation waves [A. R. Kasimov, L. M. Faria, and R. R. Rosales, Model for shock wave chaos, Phys. Rev. Lett., 110 (2013), 104104]. The equation is ut+ 1/2 (u2-uu (0-, t))x=f (x, u (0-, t)), x > 0, t < 0. It describes a detonation shock at x = 0 with the reaction zone in x > 0. We investigate the nature of the steady-state solutions of this nonlocal hyperbolic balance law, the linear stability of these solutions, and the nonlinear dynamics. We establish the existence of instability followed by a cascade of period-doubling bifurcations leading to chaos. © 2014 Society for Industrial and Applied Mathematics.

  14. Set-valued solutions for non-ideal detonation

    KAUST Repository

    Semenko, Roman; Faria, Luiz; Kasimov, Aslan R.; Ermolaev, B. S.

    2015-01-01

    The existence and structure of a steady-state gaseous detonation propagating in a packed bed of solid inert particles are analyzed in the one-dimensional approximation by taking into consideration frictional and heat losses between the gas and the particles. A new formulation of the governing equations is introduced that eliminates the difficulties with numerical integration across the sonic singularity in the reactive Euler equations. With the new algorithm, we find that when the sonic point disappears from the flow, there exists a one-parameter family of solutions parameterized by either pressure or temperature at the end of the reaction zone. These solutions (termed “set-valued” here) correspond to a continuous spectrum of the eigenvalue problem that determines the detonation velocity as a function of a loss factor.

  15. Effect of turbulence on deflagration to detonation transition

    Energy Technology Data Exchange (ETDEWEB)

    Radford, D D; Chan, C K [Atomic Energy of Canada Ltd., Pinawa, MB (Canada). Whiteshell Labs.; Azad, R S [Manitoba Univ., Winnipeg, MB (Canada). Dept. of Mechanical Engineering

    1996-12-31

    The interaction of a turbulent jet and an expanding flame kernel was examined using spark-schlieren photography and piezoelectric pressure transducers. Experiments were performed in a 9 by 9 cm, 4-m-long shock channel. Results show that an expanding flame kernel can be locally, or partially, quenched by flame stretching. The mixing of the hot combustion products, containing reactive species, with the unburnt gas in the turbulent flame-jet, created pockets of sensitized mixture. The subsequent re-ignition of the sensitized mixture could result in a local explosion. In a number of experiments the blast waves produced in the local explosion developed into detonation waves. A local explosion occurred only if there was partial quenching of the flame kernel. Partial quenching occurs when the Karlovitz-Kovaszney factor approaches unity and, therefore, it is possible to establish a set of conditions in terms of turbulent parameters for the transition to detonation. (author). 16 refs., 13 figs.

  16. Evaluation of the effects of detonation in a spherical bomb

    International Nuclear Information System (INIS)

    Kurylo, J.; Oppenheim, A.K.

    1979-11-01

    An analysis is presented of the time-dependent pressure forces and impulse loadings on the walls of the hemispherical dome of a nuclear reactor pressure vessel arising from a centrally ignited hydrogen-oxygen detonation. Investigated in this context are the effects of richness of the detonable gas mixture as well as those due to the inclusion of water vapor. In the analysis the gas mixture was treated as a perfect gas, and the partial differential equations governing the gasdynamic flow were integrated using the CLOUD CODE - a finite-difference technique set in Lagrangian coordinates and incorporating the smoothing action of artificial viscosity. The most interesting results pertain to the ringing of pressure pulses at the walls. Their frequency is quite uniform, and their pressure peaks, at levels significantly higher than that of combustion at constant volume, decay at a negligible rate

  17. Ground-based Nuclear Detonation Detection (GNDD) Technology Roadmap

    International Nuclear Information System (INIS)

    Casey, Leslie A.

    2014-01-01

    This GNDD Technology Roadmap is intended to provide guidance to potential researchers and help management define research priorities to achieve technology advancements for ground-based nuclear explosion monitoring science being pursued by the Ground-based Nuclear Detonation Detection (GNDD) Team within the Office of Nuclear Detonation Detection in the National Nuclear Security Administration (NNSA) of the U.S. Department of Energy (DOE). Four science-based elements were selected to encompass the entire scope of nuclear monitoring research and development (R&D) necessary to facilitate breakthrough scientific results, as well as deliver impactful products. Promising future R&D is delineated including dual use associated with the Comprehensive Nuclear-Test-Ban Treaty (CTBT). Important research themes as well as associated metrics are identified along with a progression of accomplishments, represented by a selected bibliography, that are precursors to major improvements to nuclear explosion monitoring.

  18. Ground-based Nuclear Detonation Detection (GNDD) Technology Roadmap

    Energy Technology Data Exchange (ETDEWEB)

    Casey, Leslie A.

    2014-01-13

    This GNDD Technology Roadmap is intended to provide guidance to potential researchers and help management define research priorities to achieve technology advancements for ground-based nuclear explosion monitoring science being pursued by the Ground-based Nuclear Detonation Detection (GNDD) Team within the Office of Nuclear Detonation Detection in the National Nuclear Security Administration (NNSA) of the U.S. Department of Energy (DOE). Four science-based elements were selected to encompass the entire scope of nuclear monitoring research and development (R&D) necessary to facilitate breakthrough scientific results, as well as deliver impactful products. Promising future R&D is delineated including dual use associated with the Comprehensive Nuclear-Test-Ban Treaty (CTBT). Important research themes as well as associated metrics are identified along with a progression of accomplishments, represented by a selected bibliography, that are precursors to major improvements to nuclear explosion monitoring.

  19. Directly thiolated modification onto the surface of detonation nanodiamonds.

    Science.gov (United States)

    Hsu, Ming-Hua; Chuang, Hong; Cheng, Fong-Yu; Huang, Ying-Pei; Han, Chien-Chung; Chen, Jiun-Yu; Huang, Su-Chin; Chen, Jen-Kun; Wu, Dian-Syue; Chu, Hsueh-Liang; Chang, Chia-Ching

    2014-05-28

    An efficient method for modifying the surface of detonation nanodiamonds (5 and 100 nm) with thiol groups (-SH) by using an organic chemistry strategy is presented herein. Thiolated nanodiamonds were characterized by spectroscopic techniques, and the atomic percentage of sulfur was analyzed by elemental analysis and X-ray photoelectron spectroscopy. The conjugation between thiolated nanodiamonds and gold nanoparticles was elucidated by transmission electron microscopy and UV-vis spectrometry. Moreover, the material did not show significant cytotoxicity to the human lung carcinoma cell line and may prospectively be applied in bioconjugated technology. The new method that we elucidated may significantly improve the approach to surface modification of detonation nanodiamonds and build up a new platform for the application of nanodiamonds.

  20. Set-valued solutions for non-ideal detonation

    KAUST Repository

    Semenko, Roman

    2015-12-11

    The existence and structure of a steady-state gaseous detonation propagating in a packed bed of solid inert particles are analyzed in the one-dimensional approximation by taking into consideration frictional and heat losses between the gas and the particles. A new formulation of the governing equations is introduced that eliminates the difficulties with numerical integration across the sonic singularity in the reactive Euler equations. With the new algorithm, we find that when the sonic point disappears from the flow, there exists a one-parameter family of solutions parameterized by either pressure or temperature at the end of the reaction zone. These solutions (termed “set-valued” here) correspond to a continuous spectrum of the eigenvalue problem that determines the detonation velocity as a function of a loss factor.

  1. Mechanical effects of gaseous detonations on a flexible confinement

    International Nuclear Information System (INIS)

    Brossard, J.; Renard, J.

    1981-01-01

    A mathematical model was developed for evaluating the effect of a detonating gaseous mixture on its elastic circular confinement. The data provided by the model were compared with experimental results. The confinement materials investigated include polyvinylchloride and stainless steel. Measurements of transverse and longitudinal deformations of the confinement material at several detonation velocities and for different material properties made it possible to determine the deformation characteristics, taking into account the precursor effect, the oscillations and their frequencies, the deformation ratio, and the dynamic amplifying factors. A certain lack of agreement between the theoretical data obtained with the aid of the model and the experimental results is probably related to simplified assumptions made in the model regarding the pressure distributions and a failure to take into account viscosity effects

  2. Retroperitoneoscopic nephrectomy in benign pathology.

    Science.gov (United States)

    Quintela, Rodrigo S; Cotta, Leonardo R; Neves, Marcelo F; Abelha, David L; Tavora, Jose E

    2006-01-01

    We report our experience with 43 retroperitoneal laparoscopic nephrectomy for benign kidney disease. All patients had a poor function from obstructive uropathology and renal atrophy. None of these patients had a previous lumbotomy. Retroperitoneoscopy was performed with 4 trocar port technique in a lateral position. The retroperitoneal space is created by using a Gaur's balloon made of sterile glove. The approach to vascular pedicle was done posteriorly and vessels were clipped by metal and Hem-o-lock (Weck Closure Systems, North Carolina, USA) clips. The sample was intact extracted in an Endo-Bag prolonging one trocar incision. Median operative time was 160 minutes and median blood loss was 200 mL. Four cases (9%) were converted to open surgery: one case due to bleeding and 3 cases due to technical difficulties regarding perirenal adherences. Most patients (39) checked out from the Hospital in day two. Four of them were left over 3 days due to wound complications. Retroperitoneoscopy offers a safe, effective and reproductive access to nephrectomy for benign pathologies.

  3. Descriptive summary of airblast effects for buried cratering detonations

    International Nuclear Information System (INIS)

    Snell, C.M.

    1976-01-01

    Detonation of a buried nuclear or high-explosive charge induces an airblast signal in the air above the explosion site. The waveform of this signal may be complex, involving features created by ground surface motion effects, venting and expansion of gas from the explosive cavity, and energy release through an unstemmed or partly stemmed emplacement hole. The basic physical mechanisms responsible for the airblast pulse and some of the techniques commonly used to predict airblast effects are described

  4. Long-term worldwide effects of multiple nuclear weapons detonations

    International Nuclear Information System (INIS)

    Anon.

    1984-01-01

    The NAS report, issued in 1975 shocked the scientific community by suggesting that detonation of a fraction of the world's nuclear arsenal (10 4 megatons) could produce a major, 30-70%, reduction in stratospheric ozone, lasting a year or more. The consequences of such a reduction in the natural barrier to solar ultraviolet radiation include the potential extinction of mammalian life. The summary section of the 1975 report is reprinted here

  5. Characterization of Rotating Detonation Engine Exhaust Through Nozzle Guide Vanes

    Science.gov (United States)

    2013-03-21

    ENY/13-M09 Abstract A Rotating Detonation Engine ( RDE ) has higher thermal efficiencies in comparison to its traditional gas turbine counterparts. Thus...as budgets decrease and fuel costs increase, RDEs have become a research focus for the United States Air Force. An integration assembly for attaching...the first Nozzle Guide Vane (NGV) section from a T63 gas turbine engine to a 6 inch diameter RDE was designed and built for this study. Pressure

  6. Detonation waves in melt-coolant interaction. Part 2. Applied analysis

    International Nuclear Information System (INIS)

    Kolev, N.I.; Hulin, H.

    2001-01-01

    Making use of the detonation theory presented in part 1 for melt-water interaction, detonation solutions for different melt-water pairs at different conditions are compared to each other. Discussion is provided on the existence of detonation solutions for water droplet - melt droplet - gas systems. The conclusion is made that even if such solution can be realized in the nature, which is highly questionable, the resulting detonation pressures will be below 200 bar. This is an important result for judging the risk of the melt-water disperse mixtures in nuclear safety analysis. In addition, the detonation pressures for alumna-continuous water systems have been found to be stronger then those for urania-continuous water systems, in agreement with the experimental observations and seems to give finally the searched for a long time explanation why alumna-water systems detonate much more violent than urania-water systems. (orig.) [de

  7. Munitions having an insensitive detonator system for initiating large failure diameter explosives

    Science.gov (United States)

    Perry, III, William Leroy

    2015-08-04

    A munition according to a preferred embodiment can include a detonator system having a detonator that is selectively coupled to a microwave source that functions to selectively prime, activate, initiate, and/or sensitize an insensitive explosive material for detonation. The preferred detonator can include an explosive cavity having a barrier within which an insensitive explosive material is disposed and a waveguide coupled to the explosive cavity. The preferred system can further include a microwave source coupled to the waveguide such that microwaves enter the explosive cavity and impinge on the insensitive explosive material to sensitize the explosive material for detonation. In use the preferred embodiments permit the deployment and use of munitions that are maintained in an insensitive state until the actual time of use, thereby substantially preventing unauthorized or unintended detonation thereof.

  8. Lightning-resistant, low-inductance detonator cables

    Energy Technology Data Exchange (ETDEWEB)

    Druce, R.L.; Lee, R.S.; Moua, K.

    1994-04-01

    A lightning strike on a flat detonator cable in close proximity to a high explosive (HE) main charge poses a possible detonation hazard if the electrical explosion of the cable launches the dielectric cover coat of the cable at a high enough velocity to shock-initiate the HE. The detonator cable for the W87 system has been demonstrated to be incapable of initiating LX-17 main-charge explosive even for a 99 percentile negative lightning strike (1). The W87 cable is a relatively high inductance cable, unsuitable for use with low-inductance firesets. We have performed tests on a low-inductance cable designed for the W89 program, which show it to be marginal in its ability to withstand a lightning strike without the possibility of initiating a heated LX-17 main charge HE. A new cable design, proposed by R.E. Lee of LLNL has been tested and shown to be capable of withstanding a 99 percentile negative lightning strike without initiating LX-17 heated to 250{degree}C.

  9. Modification of the colony tower for the Rio Blanco detonation

    International Nuclear Information System (INIS)

    Blume, J.A.; Freeman, S.A.; Honda, K.K.; Lee, L.A.

    1975-01-01

    Supplemental structural bracing was designed and installed for the 180-ft-tall Colony Tower, an experimental oil shale processing retort structure, in anticipation of its lateral response to the Rio Blanco detonation. The tower is a steel structure with both horizontal and vertical diagonal bracing. Data obtained from the earlier Project Rulison detonation indicated that an evaluation study was necessary. Design criteria that would provide an adequate margin of safety were developed based on predicted Rio Blanco ground motion. The evaluation of the unmodified structure showed that several bracing members would be subjected to forces exceeding their yield strength, and some would reach a level at which failure could occur. Further analyses were made with assumed modified bracing members. A final scheme for modified vertical bracing was established and installed. After modification, the response of the tower during the Rio Blanco detonation was measured by instruments on the ground and at various locations on the tower, and no evidence of damage was discovered. The modification of the Colony Tower and the procedures used to determine these modifications show the usefulness of current ground motion and structural response prediction technology for forecasting dynamic behavior of important structures subjected to ground motion from underground nuclear explosions. (auth)

  10. Effect of Surface Chemistry on the Fluorescence of Detonation Nanodiamonds.

    Science.gov (United States)

    Reineck, Philipp; Lau, Desmond W M; Wilson, Emma R; Fox, Kate; Field, Matthew R; Deeleepojananan, Cholaphan; Mochalin, Vadym N; Gibson, Brant C

    2017-11-28

    Detonation nanodiamonds (DNDs) have unique physical and chemical properties that make them invaluable in many applications. However, DNDs are generally assumed to show weak fluorescence, if any, unless chemically modified with organic molecules. We demonstrate that detonation nanodiamonds exhibit significant and excitation-wavelength-dependent fluorescence from the visible to the near-infrared spectral region above 800 nm, even without the engraftment of organic molecules to their surfaces. We show that this fluorescence depends on the surface functionality of the DND particles. The investigated functionalized DNDs, produced from the same purified DND as well as the as-received polyfunctional starting material, are hydrogen, hydroxyl, carboxyl, ethylenediamine, and octadecylamine-terminated. All DNDs are investigated in solution and on a silicon wafer substrate and compared to fluorescent high-pressure high-temperature nanodiamonds. The brightest fluorescence is observed from octadecylamine-functionalized particles and is more than 100 times brighter than the least fluorescent particles, carboxylated DNDs. The majority of photons emitted by all particle types likely originates from non-diamond carbon. However, we locally find bright and photostable fluorescence from nitrogen-vacancy centers in diamond in hydrogenated, hydroxylated, and carboxylated detonation nanodiamonds. Our results contribute to understanding the effects of surface chemistry on the fluorescence of DNDs and enable the exploration of the fluorescent properties of DNDs for applications in theranostics as nontoxic fluorescent labels, sensors, nanoscale tracers, and many others where chemically stable and brightly fluorescent nanoparticles with tailorable surface chemistry are needed.

  11. Shock and Detonation Physics at Los Alamos National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Robbins, David L [Los Alamos National Laboratory; Dattelbaum, Dana M [Los Alamos National Laboratory; Sheffield, Steve A [Los Alamos National Laboratory

    2012-08-22

    WX-9 serves the Laboratory and the Nation by delivering quality technical results, serving customers that include the Nuclear Weapons Program (DOE/NNSA), the Department of Defense, the Department of Homeland Security and other government agencies. The scientific expertise of the group encompasses equations-of-state, shock compression science, phase transformations, detonation physics including explosives initiation, detonation propagation, and reaction rates, spectroscopic methods and velocimetry, and detonation and equation-of-state theory. We are also internationally-recognized in ultra-fast laser shock methods and associated diagnostics, and are active in the area of ultra-sensitive explosives detection. The facility capital enabling the group to fulfill its missions include a number of laser systems, both for laser-driven shocks, and spectroscopic analysis, high pressure gas-driven guns and powder guns for high velocity plate impact experiments, explosively-driven techniques, static high pressure devices including diamond anvil cells and dilatometers coupled with spectroscopic probes, and machine shops and target fabrication facilities.

  12. Equations of state of detonation products: ammonia and methane

    Science.gov (United States)

    Lang, John; Dattelbaum, Dana; Goodwin, Peter; Garcia, Daniel; Coe, Joshua; Leiding, Jeffery; Gibson, Lloyd; Bartram, Brian

    2015-06-01

    Ammonia (NH3) and methane (CH4) are two principal product gases resulting from explosives detonation, and the decomposition of other organic materials under shockwave loading (such as foams). Accurate thermodynamic descriptions of these gases are important for understanding the detonation performance of high explosives. However, shock compression data often do not exist for molecular species in the dense gas phase, and are limited in the fluid phase. Here, we present equation of state measurements of elevated initial density ammonia and methane gases dynamically compressed in gas-gun driven plate impact experiments. Pressure and density of the shocked gases on the principal Hugoniot were determined from direct particle velocity and shock wave velocity measurements recorded using optical velocimetry (Photonic Doppler velocimetry (PDV) and VISAR (velocity interferometer system for any reflector)). Streak spectroscopy and 5-color pyrometry were further used to measure the emission from the shocked gases, from which the temperatures of the shocked gases were estimated. Up to 0.07 GPa, ammonia was not observed to ionize, with temperature remaining below 7000 K. These results provide quantitative measurements of the Hugoniot locus for improving equations of state models of detonation products.

  13. Fundamental Structure of High-Speed Reacting Flows: Supersonic Combustion and Detonation

    Science.gov (United States)

    2016-04-30

    interim, memorandum, master’s thesis , progress, quarterly, research, special, group study, etc. 3. DATES COVERED. Indicate the time during which the...liquid rocket engines, studied the concept of rotating detonation rocket engine in both gaseous and two-phase propellants . Recently, there have been...detonation waves. 4.2 Experimental Setup The linear model detonation engine (LDME) serves as an “unwrapped” RDE test bed, shown in Fig. 4.1. Design

  14. Escalation and propagation of thermal detonation in the corium-water systems

    International Nuclear Information System (INIS)

    Melikhov, O.I.; Melikhov, V.I.; Sokolin, A.V.

    2001-01-01

    The thermal detonation taking into account micro-interaction processes model has been applied to study thermal detonation wave escalation and propagation in the corium-water mixture. Transient escalation stage and subsequent steady-state propagation stage of the thermal detonation have been calculated. The essential decrease of the escalation length in comparison with the previous results calculated without micro-interaction concept has been obtained. (authors)

  15. The role of multidimensional instabilities in direct initiation of gaseous detonations in free space

    KAUST Repository

    Shen, Hua

    2017-01-20

    We numerically investigate the direct initiation of detonations driven by the propagation of a blast wave into a unconfined gaseous combustible mixture to study the role played by multidimensional instabilities in direct initiation of stable and unstable detonations. To this end, we first model the dynamics of unsteady propagation of detonation using the one-dimensional compressible Euler equations with a one-step chemical reaction model and cylindrical geometrical source terms. Subsequently, we use two-dimensional compressible Euler equations with just the chemical reaction source term to directly model cylindrical detonations. The one-dimensional results suggest that there are three regimes in the direct initiation for stable detonations, that the critical energy for mildly unstable detonations is not unique, and that highly unstable detonations are not self-sustainable. These phenomena agree well with one-dimensional theories and computations available in the literature. However, our two-dimensional results indicate that one-dimensional approaches are valid only for stable detonations. In mildly and highly unstable detonations, one-dimensional approaches break down because they cannot take the effects and interactions of multidimensional instabilities into account. In fact, instabilities generated in multidimensional settings yield the formation of strong transverse waves that, on one hand, increase the risk of failure of the detonation and, on the other hand, lead to the initiation of local over-driven detonations that enhance the overall self-sustainability of the global process. The competition between these two possible outcomes plays an important role in the direct initiation of detonations.

  16. A discussion of the kamlet-jacobs formula for the detonation pressure

    Energy Technology Data Exchange (ETDEWEB)

    Kazandjian, Luc; Danel, Jean-Francois [Commissariat a l' Energie Atomique, Centre CEA-DIF, B. P. 12, F-91680 Bruyeres-le-Chatel (France)

    2006-02-15

    The main features of the Kamlet-Jacobs formula for the detonation pressure of C-H-N-O explosives are analytically derived from a BKW (Becker-Kistiakowsky-Wilson) equation of state of the detonation products. In the derivation, well-known typical values at the Chapman-Jouguet state, in particular the nearly constant value of the relative volume of the detonation products, are used. (Abstract Copyright [2006], Wiley Periodicals, Inc.)

  17. Phenomenological Model for Infrared Emissions from High-Explosive Detonation Fireballs

    Science.gov (United States)

    2007-09-01

    meterological data collected near the time of this detonation event. . . . . . . . . . . . . . . . . . . . . . . . . 26 6 Brilliant Flash II test geometry...from meterological data collected near the time of this detonation event. Most of the absorption features are due to water vapor; a few regions are noted...profile computed from meterological data collected near the time of this detonation event. of the instrument. Examination of the imaginary component does

  18. Influence of carbon monoxide additions on the sensitivity of the dry hydrogen-air mixtures to detonation

    International Nuclear Information System (INIS)

    Magzumov, A.E.; Kirillov, I.A.; Fridman, A.A.; Rusanov, V.D.

    1995-01-01

    Under severe accident conditions of water cooled nuclear reactors the hydrogen-air detonation represents one of the most hazardous events which can result in the reactor containment damage. An important factor related with the measure of gas mixture detonability is the detonation cell size which correlates with the critical tube diameter and detonation initiation energy. A numerical kinetic study is presented of the influence of carbon monoxide admixtures (from 0 vol.% to 40 vol.%) upon the sensitivity (detonation cell size) of the dry hydrogen-air gas mixtures to detonation in post-accident containment atmosphere. (author). 3 refs., 3 figs

  19. A survey on spinal cord injuries resulting from stabbings: a case series study of 12 years' experience.

    Science.gov (United States)

    Saeidiborojeni, Hamid Reza; Moradinazar, Mehdi; Saeidiborojeni, Sepehr; Ahmadi, Alireza

    2013-01-01

    Penetrating spinal cord injuries (SCIs) are an uncommon injury and not reported very frequently. SCIs cause sensory, motor and genitourinary system problems or a combination of sensorimotor dysfunctions. These are among the most debilitating kinds of disorders and negatively affect quality of life, not only for the patient, but also for their family members. Therefore, the present study aims to evaluate complete or incomplete SCIs and the course of the injury and the prognosis for SCIs caused by stab wounds. This case-series design study was performed on 57 patients attending the emergency department of Taleqani Trauma Center (Kermanshah, Iran) due to SCIs caused by violent encounters involving sharp objects such as a knife, dagger, whittle and Bowie-knife between 1999 and 2011. An assessment of sensory and motor functions was performed as part of the neurological examination on admission, and during the treatment, using the Frankel Classification grading system, and the results were recorded. The average age of patients was 27 years (SD= 7.9, Range=17 to 46 years). The results of the study showed a proportion of cervical, thoracic and lumbar injuries of 23 (40%), 24 (42%) and 10 (18%), respectively. There was no case of cerebrospinal fluid leakage (CSF) or infection at the wound site in the subjects. Regarding the extent of the SCI, the combined neurological assessment showed that several patients (43%) had a complete SCI with no sensory and motor functions in the sacral segments and the segments below the site of injury. In 32 patients (57%) incomplete injuries were observed; i.e. they showed only some degrees of sensory-motor functions that were below the neurological level. Both complete and incomplete SCIs are of great importance because the prognosis of SCI is directly associated with the location and extent of injury. It should be considered that partial recovery from SCIs is possible in few cases of complete injuries. Therefore, all the patients should be

  20. Shock-to-detonation transition in solid heterogeneous explosives; La transition choc-detonation dans les explosifs solides heterogenes

    Energy Technology Data Exchange (ETDEWEB)

    Belmas, R.

    2003-07-01

    This paper is an overview of the studies performed during the last decades on the shock-to-detonation transition process in heterogeneous explosives. We present the experimental and theoretical approaches mentioned in the literature and/or developed at CEA/DAM. The aim is to identify which main mechanisms govern this transition process and to evaluate the relevance of the available modeling tools. (author)

  1. Dynamics of the formation of the condensed phase particles at detonation of high explosives

    CERN Document Server

    Evdokov, O V; Kulipanov, G N; Luckjanchikov, L A; Lyakhov, N Z; Mishnev, S I; Sharafutdinov, M R; Sheromov, M A; Ten, K A; Titov, V M; Tolochko, B P; Zubkov, P I

    2001-01-01

    The article presents the results of the experimental study SAXS on condensed carbon particles that appear at the detonation of a high explosive. It was shown that the SAXS signal rises for 1.5-4 mu s after the detonation front passing. The SAXS signal in trotyl and its alloys with hexogen starts just after the compression of the material in the detonation wave. In octogen, hexogen and PETN, the SAXS signal appears in 0.5 mu s and is much smaller than the signal at the detonation of trotyl and its alloys with hexogen.

  2. Detonation and fragmentation modeling for the description of large scale vapor explosions

    International Nuclear Information System (INIS)

    Buerger, M.; Carachalios, C.; Unger, H.

    1985-01-01

    The thermal detonation modeling of large-scale vapor explosions is shown to be indispensable for realistic safety evaluations. A steady-state as well as transient detonation model have been developed including detailed descriptions of the dynamics as well as the fragmentation processes inside a detonation wave. Strong restrictions for large-scale vapor explosions are obtained from this modeling and they indicate that the reactor pressure vessel would even withstand explosions with unrealistically high masses of corium involved. The modeling is supported by comparisons with a detonation experiment and - concerning its key part - hydronamic fragmentation experiments. (orig.) [de

  3. Etiopathogenesis of benign prostatic hypeprlasia

    Directory of Open Access Journals (Sweden)

    Jie Tang

    2009-01-01

    Full Text Available Benign prostatic hyperplasia (BPH is the most common condition affecting men older than 50 years of age. It affects about 10 percent of men under the age of 40, and increases to about 80 percent by 80 years of age. BPH is a hyperplastic process of the fibromuscular stromal and glandular epithelial elements of the prostate. Aging and the presence of the functional testes are the two established risk factors for the development of BPH. The etiopathogenesis of BPH is still largely unresolved, but multiple partially overlapping and complementary theories have been proposed, all of which seem to be operative at least to some extent. This review is focused on recent progress in this area and on the growing consensus for the important mechanisms underlying the etiology and pathogenesis of BPH.

  4. Familial benign nonprogressive myoclonic epilepsies.

    Science.gov (United States)

    Striano, Pasquale; de Falco, Fabrizio A; Minetti, Carlo; Zara, Federico

    2009-05-01

    Work on the classification of epileptic syndromes is ongoing, and many syndromes are still under discussion. In particular, special difficulty still persists in correctly classifying epilepsies with myoclonic seizures. The existence of special familial epileptic syndromes primarily showing myoclonic features has been recently suggested on the basis of a clear pattern of inheritance or on the identification of new chromosomal genetic loci linked to the disease. These forms in development include familial infantile myoclonic epilepsy (FIME), benign adult familial myoclonic epilepsy (BAFME), or autosomal dominant cortical myoclonus and epilepsy (ADCME), and, maybe, adult-onset myoclonic epilepsy (AME). In the future, the identification of responsible genes and the protein products will contribute to our understanding of the molecular pathways of epileptogenesis and provide neurobiologic criteria for the classification of epilepsies, beyond the different phenotypic expression.

  5. Benign communicating hydrocephalus in children

    International Nuclear Information System (INIS)

    Kendall, B.; Holland, I.

    1981-01-01

    A review was performed of the computed tomograms (CTs) of 500 children which had been reported as showing widening of the supratentorial subarachnoid spaces with normal cerebral substance. On the basis of this a radiological diagnosis of cerebral atrophy had been made in all but five, who were said to have mengalencephaly. From these, the children with large or abnormally enlarging heads, but normal or only slightly enlarged ventricles, were selected; there were 40 such cases (8%). The clinical condition either improved or remained stable over a period of 2 years; in the majority the scan abnormality regressed (22.5%) or remained static (67.5%). In three cases there was slight progression of the CT changes before stabilisation, but only one case developed classical communicating hydrocephalus necessitating a shunt procedure. This condition is a generally benign and mild form of communicating hydrocephalus, for which an aetiological factor was apparent in about two-thirds of the cases studied. (orig.)

  6. Benign paroxysmal torticollis in infancy

    Directory of Open Access Journals (Sweden)

    Dimitrijević Lidija

    2006-01-01

    Full Text Available Background. Benign paroxysmal torticollis (BPT is an episodic functional disorder of unknown etiology, characterized by the periods of torticollic posturing of the head, that occurs in the early months of life in healthy children. Case report. We reported two patients with BPT. In the first patient the symptoms were observed at the age of day 20, and disappeared at the age of 3 years. There were 10 episodes, of which 2 were followed by vomiting, pallor, irritability and the abnormal trunk posture. In the second patient, a 12-month-old girl, BPT started from day 15. She had 4 episodes followed by vomiting in the first year. Both girls had the normal psychomotor development. All diagnostical tests were normal. Conclusion. The recognition of BPT, as well as its clinical course may help to avoid not only unnecessary tests and the treatment, but also the anxiety of the parents.

  7. Scintigraphy in benign thyroid disorders

    International Nuclear Information System (INIS)

    Mahlstedt, J.

    2004-01-01

    For diagnosis, therapy and prognosis of benign thyroidal disorders thyroidal scintigraphy has to be seen in full strength in relation to thyroid hormone metabolism and regulation. Thyroidal iodine avidity can easily be assessed by TcTU ( 99m Tc-thyroid-up-take 20 min p.inj.), as the well known standard measure for the service of goiter patients. TcTU and TSH show concordance, i.e. direct correlation, when thyroid regulation is intact, however there is no correlation, i.e. discordance, in disorders such as destruction, autonomy oder immunogenic stimulation. The strategy to evaluate concordance/discordance of TcTU and TSH in outpatient routine work (''one stop shop'') is demonstrated in a variety of clinical situations being not always conform to current guide lines and recommendations. (orig.)

  8. Benign paroxysmal positional vertigo in Parkinson's disease

    NARCIS (Netherlands)

    Wensen, E. van; Leeuwen, R.B. van; Zaag-Loonen, H.J. van der; Masius-Olthof, S.; Bloem, B.R.

    2013-01-01

    BACKGROUND: Dizziness is a frequent complaint of patients with Parkinson's disease (PD), and orthostatic hypotension (OH) is often thought to be the cause. We studied whether benign paroxysmal positional vertigo (BPPV) could also be an explanation. AIM: To assess the prevalence of benign paroxysmal

  9. Factors influencing the reliability of non-electric detonating circuit in underground uranium mines and preventive measures of misfiring

    International Nuclear Information System (INIS)

    Li Qin

    2010-01-01

    Characteristics of non-electric detonating circuit are introduced. The main factors influencing the reliability of non-electric detonating circuit are described. Taking an underground blasting of a uranium mine for example, the reliability of various kinds of detonating network system is calculated using the reliability theory and numerical analysis method. The reasons that cause the misfiring in non-electric detonating circuit system are analyzed, and preventive measures are put forward.(authors)

  10. Validating the Western Trauma Association algorithm for managing patients with anterior abdominal stab wounds: a Western Trauma Association multicenter trial.

    Science.gov (United States)

    Biffl, Walter L; Kaups, Krista L; Pham, Tam N; Rowell, Susan E; Jurkovich, Gregory J; Burlew, Clay Cothren; Elterman, J; Moore, Ernest E

    2011-12-01

    The optimal management of stable patients with anterior abdominal stab wounds (AASWs) remains a matter of debate. A recent Western Trauma Association (WTA) multicenter trial found that exclusion of peritoneal penetration by local wound exploration (LWE) allowed immediate discharge (D/C) of 41% of patients with AASWs. Performance of computed tomography (CT) scanning or diagnostic peritoneal lavage (DPL) did not improve the D/C rate; however, these tests led to nontherapeutic (NONTHER) laparotomy (LAP) in 24% and 31% of cases, respectively. An algorithm was proposed that included LWE, followed by either D/C or admission for serial clinical assessments, without further imaging or invasive testing. The purpose of this study was to evaluate the safety and efficacy of the algorithm in providing timely interventions for significant injuries. A multicenter, institutional review board-approved study enrolled patients with AASWs. Management was guided by the WTA AASW algorithm. Data on the presentation, evaluation, and clinical course were recorded prospectively. Two hundred twenty-two patients (94% men, age, 34.7 years ± 0.3 years) were enrolled. Sixty-two (28%) had immediate LAP, of which 87% were therapeutic (THER). Three (1%) died and the mean length of stay (LOS) was 6.9 days. One hundred sixty patients were stable and asymptomatic, and 81 of them (51%) were managed entirely per protocol. Twenty (25%) were D/C'ed from the emergency department after (-) LWE, and 11 (14%) were taken to the operating room (OR) for LAP when their clinical condition changed. Two (2%) of the protocol group underwent NONTHER LAP, and no patient experienced morbidity or mortality related to delay in treatment. Seventy-nine (49%) patients had deviations from protocol. There were 47 CT scans, 11 DPLs, and 9 laparoscopic explorations performed. In addition to the laparoscopic procedures, 38 (48%) patients were taken to the OR based on test results rather than a change in the patient's clinical

  11. Method and system for making integrated solid-state fire-sets and detonators

    Science.gov (United States)

    O`Brien, D.W.; Druce, R.L.; Johnson, G.W.; Vogtlin, G.E.; Barbee, T.W. Jr.; Lee, R.S.

    1998-03-24

    A slapper detonator comprises a solid-state high-voltage capacitor, a low-jitter dielectric breakdown switch and trigger circuitry, a detonator transmission line, an exploding foil bridge, and a flier material. All these components are fabricated in a single solid-state device using thin film deposition techniques. 13 figs.

  12. Method and system for making integrated solid-state fire-sets and detonators

    Energy Technology Data Exchange (ETDEWEB)

    O' Brien, Dennis W. (Livermore, CA); Druce, Robert L. (Union City, CA); Johnson, Gary W. (Livermore, CA); Vogtlin, George E. (Fremont, CA); Barbee, Jr., Troy W. (Palo Alto, CA); Lee, Ronald S. (Livermore, CA)

    1998-01-01

    A slapper detonator comprises a solid-state high-voltage capacitor, a low-jitter dielectric breakdown switch and trigger circuitry, a detonator transmission line, an exploding foil bridge, and a flier material. All these components are fabricated in a single solid-state device using thin film deposition techniques.

  13. 49 CFR 178.318 - Specification MC 201; container for detonators and percussion caps.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Specification MC 201; container for detonators and percussion caps. 178.318 Section 178.318 Transportation Other Regulations Relating to Transportation PIPELINE....318 Specification MC 201; container for detonators and percussion caps. ...

  14. Impact of Dissociation and Sensible Heat Release on Pulse Detonation and Gas Turbine Engine Performance

    Science.gov (United States)

    Povinelli, Louis A.

    2001-01-01

    A thermodynamic cycle analysis of the effect of sensible heat release on the relative performance of pulse detonation and gas turbine engines is presented. Dissociation losses in the PDE (Pulse Detonation Engine) are found to cause a substantial decrease in engine performance parameters.

  15. 30 CFR 75.1312 - Explosives and detonators in underground magazines.

    Science.gov (United States)

    2010-07-01

    ... magazines. 75.1312 Section 75.1312 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF... Blasting § 75.1312 Explosives and detonators in underground magazines. (a) The quantity of explosives kept..., explosives and detonators taken underground shall be kept in— (1) Separate, closed magazines at least 5 feet...

  16. 30 CFR 75.1313 - Explosives and detonators outside of magazines.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Explosives and detonators outside of magazines... § 75.1313 Explosives and detonators outside of magazines. (a) The quantity of explosives outside a magazine for use in a working section or other area where blasting is to be performed shall— (1) Not exceed...

  17. Effects of hypothetical improvised nuclear detonation on the electrical infrastructure

    International Nuclear Information System (INIS)

    Barrett, Christopher L.; Eubank, Stephen; Evrenosoglu, C. Yaman; Marathe, Achla; Marathe, Madhav V.; Phadke, Arun; Thorp, James; Vullikanti, Anil

    2013-01-01

    We study the impacts of a hypothetical improvised nuclear detonation (IND) on the electrical infrastructure and its cascading effects on other urban inter-dependent infrastructures of a major metropolitan area in the US. We synthesize open source information, expert knowledge, commercial software and Google Earth data to derive a realistic electrical transmission and distribution network spanning the region. A dynamic analysis of the geo-located grid is carried out to determine the cause of malfunction of components, and their short-term and long-term effect on the stability of the grid. Finally a detailed estimate of the cost of damage to the major components of the infrastructure is provided.

  18. Deflagration-to-Detonation Transition in Heteorogeneous Solids: A Bibliography.

    Science.gov (United States)

    1980-11-01

    and Rockets, Vol. 9. No. 6, 1972, pp. 415-419. 1.4 Francois, D., and L. Joly; " La Rupture des Metaux; Ecole d’ete de la Colle sur Loup ," Masson et Cie...Computer Program for Multifield Fluid Flows," Los Alamos Scientific Laboratory, LA -5680, 1974. 5.3, 9 Nnderssen, K. E. B.; "Pressure Drop in Ideal...5.6, 6, 9 Forest, C. A.: "Burning and Detonation," Los Alamos Scientific Laboratory, LA -7245, July 1978. 2, 3, 4 Fox, J.; "Flow Regimes in

  19. Introduction to Physics and Chemistry of Combustion Explosion, Flame, Detonation

    CERN Document Server

    Liberman, Michael A

    2008-01-01

    Most of the material covered in this book deals with the fundamentals of chemistry and physics of key processes and fundamental mechanisms for various combustion and combustion related phenomena in gaseous combustible mixture. It provides the reader with basic knowledge of burning processes and mechanisms of reaction wave propagation. The combustion of a gas mixture (flame, explosion, detonation) is necessarily accompanied by motion of the gas. The process of combustion is therefore not only a chemical phenomenon but also one of gas dynamics. The material selection focuses on the gas phase and

  20. Effects of hypothetical improvised nuclear detonation on the electrical infrastructure

    Energy Technology Data Exchange (ETDEWEB)

    Barrett, Christopher L.; Eubank, Stephen; Evrenosoglu, C. Yaman; Marathe, Achla; Marathe, Madhav V.; Phadke, Arun; Thorp, James; Vullikanti, Anil [Virginia Tech, Blacksburg, VA (United States). Network Dynamics and Simulation Science Lab.

    2013-07-01

    We study the impacts of a hypothetical improvised nuclear detonation (IND) on the electrical infrastructure and its cascading effects on other urban inter-dependent infrastructures of a major metropolitan area in the US. We synthesize open source information, expert knowledge, commercial software and Google Earth data to derive a realistic electrical transmission and distribution network spanning the region. A dynamic analysis of the geo-located grid is carried out to determine the cause of malfunction of components, and their short-term and long-term effect on the stability of the grid. Finally a detailed estimate of the cost of damage to the major components of the infrastructure is provided.

  1. Surface functionalization of detonation nanodiamonds by phosphonic dichloride derivatives.

    Science.gov (United States)

    Presti, Charlene; Alauzun, Johan G; Laurencin, Danielle; Mutin, P Hubert

    2014-08-05

    A new method for the functionalization of detonation nanodiamonds (DNDs) is proposed, on the basis of surface modification with phosphonic dichloride derivatives. DNDs were first modified by phenylphosphonic dichloride, and the grafting modes and hydrolytic stability under neutral conditions were investigated using (1)H, (13)C, and (31)P solid state NMR spectroscopy, Fourier transform infrared spectroscopy, as well as elemental analysis. Then, in order to illustrate the possibilities offered by this method, DNDs functionalized by mesityl imidazolium groups were obtained by postmodification of DNDs modified by 12-bromododecylphosphonic dichloride. The oxidative thermal stability of the functionalized DNDs was investigated using thermogravimetric analysis.

  2. High-resolution electron microscopy of detonation nanodiamond

    International Nuclear Information System (INIS)

    Iakoubovskii, K; Mitsuishi, K; Furuya, K

    2008-01-01

    The structure of individual nanodiamond grains produced by the detonation of carbon-based explosives has been studied with a high-vacuum aberration-corrected electron microscope. Many grains show a well-resolved cubic diamond lattice with negligible contamination, thereby demonstrating that the non-diamond shell, universally observed on nanodiamond particles, could be intrinsic to the preparation process rather than to the nanosized diamond itself. The strength of the adhesion between the nanodiamond grains, and the possibility of their patterning with sub-nanometer precision, are also demonstrated

  3. High-resolution electron microscopy of detonation nanodiamond

    Energy Technology Data Exchange (ETDEWEB)

    Iakoubovskii, K; Mitsuishi, K [Quantum Dot Research Center, National Institute for Materials Science, 3-13 Sakura, Tsukuba 305-0005 (Japan); Furuya, K [High Voltage Microscopy Station, National Institute for Materials Science, 3-13 Sakura, Tsukuba 305-0005 (Japan)], E-mail: Iakoubovskii.Konstantin@nims.go.jp

    2008-04-16

    The structure of individual nanodiamond grains produced by the detonation of carbon-based explosives has been studied with a high-vacuum aberration-corrected electron microscope. Many grains show a well-resolved cubic diamond lattice with negligible contamination, thereby demonstrating that the non-diamond shell, universally observed on nanodiamond particles, could be intrinsic to the preparation process rather than to the nanosized diamond itself. The strength of the adhesion between the nanodiamond grains, and the possibility of their patterning with sub-nanometer precision, are also demonstrated.

  4. Nocturia and benign prostatic hyperplasia

    Directory of Open Access Journals (Sweden)

    Laketić Darko

    2008-01-01

    Full Text Available Background/Aim. Nocturia often occurs in patients with benign prostate hyperplasia (BPH. The aim of the study was to investigate the frequency of nocturia in patients with BPH. Nocturia and other factors associated with it were also investigated. Methods. Forty patients with the confirmed diagnosis of BPH were studied. Transurethral and transvesical prostatectomy were performed in all the patients. Symptoms were evaluated with the International Prostate Symptom Score before, as well as three and six months after the surgery. All the results were compared with the control group. Results. There was no statistically significant difference between the patients before and after the surgery regarding nocturia. There was, however, a statistically significant difference between the operated patients and the control group regarding nocturia, as well as a statistically significant correlation between noctruia and the age of the patients in both the investigated and the control group. A correlation also existed between nocturia and the prostatic size. Conclusion. There was no statistically significant improvement in symptoms of nocturia after the surgery. It is necessary to be very careful in decision making in patients with nonabsolute indiction for surgery and isolated bothersome symptom of nocturia. Age of a patient should also be considered in the evaluation of favorable result of the surgery because of a significant correlation between noctura and the age of a patient.

  5. Management of Benign Biliary Strictures

    International Nuclear Information System (INIS)

    Laasch, Hans-Ulrich; Martin, Derrick F.

    2002-01-01

    Benign biliary strictures are most commonly a consequence of injury at laparoscopic cholecystectomy or fibrosis after biliary-enteric anastomosis. These strictures are notoriously difficult to treat and traditionally are managed by resection and fashioning of acholedocho- or hepato-jejunostomy. Promising results are being achieved with newer minimally invasive techniques using endoscopic or percutaneous dilatation and/or stenting and these are likely to play an increasing role in the management. Even low-grade biliary obstruction carries the risks of stone formation, ascending cholangitis and hepatic cirrhosis and it is important to identify and treat this group of patients. There is currently no consensus on which patient should have what type of procedure, and the full range of techniques may not be available in all hospitals. Careful assessment of the risks and likely benefits have to be made on an individual basis. This article reviews the current literature and discusses the options available. The techniques of endoscopic and percutaneous dilatation and stenting are described with evaluation of the likely success and complication rates and compared to the gold standard of biliary-enteric anastomosis

  6. Benign clavicular lesions that may mimic malignancy

    International Nuclear Information System (INIS)

    Gerscovich, E.G.; Greenspan, A.; Szabo, R.M.

    1991-01-01

    Nontraumatic lesions of the clavicle are infrequent. Of these, malignant tumors are more common than benign lesions. From January 1988 to January 1990, we examined 17 patients with benign lesions of the clavicle; in 8, the morphologic appearance of the lesion raised the possibility of malignancy in the differential diagnosis. The radiologic findings in these patients are presented. We propose that the unique shape and embryologic development of the clavicle may contribute to the atypical, aggressive presentation of some benign lesions in that bone. (orig.)

  7. A study of the benign cementoblastoma

    International Nuclear Information System (INIS)

    Choi, Won Jae; Choi, Eui Hwan

    1994-01-01

    The benign cementoblastoma is a benign odontogenic tumor of cemental-forming tissue, which has an unlimited growth potential, The radiographic appearance of the lesion is pathognomonic and consists of a radiopaque mass surrounded by a thin radiolucent line. This mass is inseparable, radiologically, from the tooth root and is attached to it, Microscopic evaluation suggests that the lesion enlarges by peripheral growth, with the center of the neoplasm being more calcified and inactive than the periphery. We have observed two cases of benign cementoblastoma (mature calcified stage) occurred in the left mandibular first molar of 22-year old man and 14-year-old man.

  8. Reflection Patterns Generated by Condensed-Phase Oblique Detonation Interaction with a Rigid Wall

    Science.gov (United States)

    Short, Mark; Chiquete, Carlos; Bdzil, John; Meyer, Chad

    2017-11-01

    We examine numerically the wave reflection patterns generated by a detonation in a condensed phase explosive inclined obliquely but traveling parallel to a rigid wall as a function of incident angle. The problem is motivated by the characterization of detonation-material confiner interactions. We compare the reflection patterns for two detonation models, one where the reaction zone is spatially distributed, and the other where the reaction is instantaneous (a Chapman-Jouguet detonation). For the Chapman-Jouguet model, we compare the results of the computations with an asymptotic study recently conducted by Bdzil and Short for small detonation incident angles. We show that the ability of a spatially distributed reaction energy release to turn flow streamlines has a significant impact on the nature of the observed reflection patterns. The computational approach uses a shock-fit methodology.

  9. Ignition Study on a Rotary-valved Air-breathing Pulse Detonation Engine

    Science.gov (United States)

    Wu, Yuwen; Han, Qixiang; Shen, Yujia; Zhao, Wei

    2017-05-01

    In the present study, the ignition effect on detonation initiation was investigated in the air-breathing pulse detonation engine. Two kinds of fuel injection and ignition methods were applied. For one method, fuel and air was pre-mixed outside the PDE and then injected into the detonation tube. The droplet sizes of mixtures were measured. An annular cavity was used as the ignition section. For the other method, fuel-air mixtures were mixed inside the PDE, and a pre-combustor was utilized as the ignition source. At firing frequency of 20 Hz, transition to detonation was obtained. Experimental results indicated that the ignition position and initial flame acceleration had important effects on the deflagration-to-detonation transition.

  10. Deflagration-to-detonation transition in gases in tubes with cavities

    Science.gov (United States)

    Smirnov, N. N.; Nikitin, V. F.; Phylippov, Yu. G.

    2010-12-01

    The existence of a supersonic second combustion mode — detonation — discovered by Mallard and Le Chatelier and by Berthélot and Vieille in 1881 posed the question of mechanisms for transition from one mode to the other. In the period 1959-1969, experiments by Salamandra, Soloukhin, Oppenheim, and their coworkers provided insights into this complex phenomenon. Since then, among all the phenomena related to combustion processes, deflagration-to-detonation transition is, undoubtedly, the most intriguing one. Deflagration-to-detonation transition (DDT) in gases is connected with gas and vapor explosion safety issues. Knowing mechanisms of detonation onset control is of major importance for creating effective mitigation measures addressing two major goals: to prevent DDT in the case of mixture ignition, or to arrest the detonation wave in the case where it has been initiated. A new impetus to the increase in interest in deflagration-to-detonation transition processes was given by the recent development of pulse detonation devices. The probable application of these principles to creation of a new generation of engines put the problem of effectiveness of pulse detonating devices at the top of current research needs. The effectiveness of the pulse detonation cycle turned out to be the key factor characterizing the Pulse Detonation Engine (PDE), whose operation modes were shown to be closely related to periodical onset and degeneration of a detonation wave. Those unsteady-state regimes should be self-sustained to guarantee a reliable operation of devices using the detonation mode of burning fuels as a constitutive part of their working cycle. Thus deflagration-to-detonation transition processes are of major importance for the issue. Minimizing the predetonation length and ensuring stability of the onset of detonation enable one to increase the effectiveness of a PDE. The DDT turned out to be the key factor characterizing the PDE operating cycle. Thus, the problem of

  11. Research on design and firing performance of Si-based detonator

    Directory of Open Access Journals (Sweden)

    Rui-zhen Xie

    2014-03-01

    Full Text Available For the chip integration of MEMS (micro-electromechanical system safety and arming device, a miniature detonator needs to be developed to reduce the weight and volume of explosive train. A Si-based micro-detonator is designed and fabricated, which meets the requirement of MEMS safety and arming device. The firing sensitivity of micro-detonator is tested according to GJB/z377A-94 sensitivity test methods: Langlie. The function time of micro-detonator is measured using wire probe and photoelectric transducer. The result shows the average firing voltage is 6.4 V when the discharge capacitance of firing electro-circuit is 33 μF. And the average function time is 5.48 μs. The firing energy actually utilized by Si-based micro-detonator is explored.

  12. Studies on the radioactive contamination due to nuclear detonations III. On the method of estimating the probable time of nuclear detonation from the measurements of gross-activity

    Energy Technology Data Exchange (ETDEWEB)

    Nishiwaki, Yasushi [Nuclear Reactor Laboratory, Tokyo Institute of Technology, Tokyo (Japan); Nuclear Reactor Laboratoroy, Kinki University, Fuse City, Osaka Precture (Japan)

    1961-11-25

    Since it has been observed in Spring of 1954 that a considerable amount of fission products mixture fell with the rain following a large scale nuclear detonation conducted in Bikini area in the South Pacific by the United States Atomic Energy Commission, it has become important, especially from the health physics standpoint, to estimate the effective average age of the fission products mixture after the nuclear detonation. If the energy transferred to the atmospheric air at the time of nuclear detonation is large enough (order of megaton at the distance of about 4000 km), the probable time and test site of nuclear detonation may be estimated with considerable accuracy, from the records of the pressure wave caused by the detonation in the microbarographs at different meteorological stations. Even in this case, in order to estimate the possible correlation between the artificial radioactivity observed in the rain and the probable detonation, it is often times desirable to estimate the effective age of the fission products mixture in the rain from the decay measurement of the radioactivity.

  13. Studies on the radioactive contamination due to nuclear detonations III. On the method of estimating the probable time of nuclear detonation from the measurements of gross-activity

    International Nuclear Information System (INIS)

    Nishiwaki, Yasushi

    1961-01-01

    Since it has been observed in Spring of 1954 that a considerable amount of fission products mixture fell with the rain following a large scale nuclear detonation conducted in Bikini area in the South Pacific by the United States Atomic Energy Commission, it has become important, especially from the health physics standpoint, to estimate the effective average age of the fission products mixture after the nuclear detonation. If the energy transferred to the atmospheric air at the time of nuclear detonation is large enough (order of megaton at the distance of about 4000 km), the probable time and test site of nuclear detonation may be estimated with considerable accuracy, from the records of the pressure wave caused by the detonation in the microbarographs at different meteorological stations. Even in this case, in order to estimate the possible correlation between the artificial radioactivity observed in the rain and the probable detonation, it is often times desirable to estimate the effective age of the fission products mixture in the rain from the decay measurement of the radioactivity

  14. Benign Metastatic Leiomyoma Presenting as a Hemothorax

    Directory of Open Access Journals (Sweden)

    Anna M. Ponea

    2013-01-01

    Full Text Available Uterine leiomyomas have been reported to metastasize to various organs including the lungs, skeletal muscles, bone marrow, peritoneum, and heart. They may present with symptoms related to the metastases several years after hysterectomy. These tumors regress after menopause, and it is rare to detect active tumors in postmenopausal women. Despite their ability to metastasize, they are considered to be benign due to the lack of anaplasia. Pulmonary benign metastasizing leiomyoma is usually detected in the form of pulmonary nodules incidentally on imaging. Tissue biopsy of these nodules is required to identify them as benign metastasizing leiomyomas. Immunohistochemical analysis and molecular profiling may further help detect any malignant transformation in it. Untreated pulmonary benign metastasizing leiomyoma may result in the formation of cystic structures, destruction of lung parenchyma, and hemothorax and may cause respiratory failure. Surgical resection and hormonal therapy help prevent progression of this disease and provide an avenue for a cure.

  15. Theoretical study on thermodynamic and detonation properties of polynitrocubanes

    Energy Technology Data Exchange (ETDEWEB)

    Ju, Xue-Hai [Department of Chemistry, Nanjing University of Science and Technology, Nanjing (China); Wang, Zun-Yao [School of Biological and Chemical Engineering, Jiaxing University, Zhejiang Jiaxing (China)

    2009-04-15

    We investigated the heat of formation ({delta}{sub f}H) of polynitrocubanes using density functional theory B3LYP and HF methods with 6-31G{sup *}, 6-311+G{sup **}, and cc-pVDZ basis sets. The results indicate that {delta}{sub f}H firstly decreases (nitro number m=0-2) and then increases (m=4-8) with each additional nitro group being introduced to the cubane skeleton. {delta}{sub f}H of octanitrocubane is predicted to be 808.08 kJ mol{sup -1} at the B3LYP/6-311+G{sup **} level. The Gibbs free energy of formation ({delta}{sub f}G) increases by about 40-60 kJ mol{sup -1} with each nitro group being added to the cubane when the substituent number is fewer than 4, then {delta}{sub f}G increases by about 100-110 kJ mol{sup -1} with each additional group being attached to the cubic skeleton. Both the detonation velocity and the pressure for polynitrocubanes increase as the number of substituents increases. Detonation velocity and pressure of octanitrocubane are substantially larger than the famous widely used explosive cyclotetramethylenetetranitramine (HMX). (Abstract Copyright [2009], Wiley Periodicals, Inc.)

  16. An Equilibrium-Based Model of Gas Reaction and Detonation

    International Nuclear Information System (INIS)

    Trowbridge, L.D.

    2000-01-01

    During gaseous diffusion plant operations, conditions leading to the formation of flammable gas mixtures may occasionally arise. Currently, these could consist of the evaporative coolant CFC-114 and fluorinating agents such as F2 and ClF3. Replacement of CFC-114 with a non-ozone-depleting substitute is planned. Consequently, in the future, the substitute coolant must also be considered as a potential fuel in flammable gas mixtures. Two questions of practical interest arise: (1) can a particular mixture sustain and propagate a flame if ignited, and (2) what is the maximum pressure that can be generated by the burning (and possibly exploding) gas mixture, should it ignite? Experimental data on these systems, particularly for the newer coolant candidates, are limited. To assist in answering these questions, a mathematical model was developed to serve as a tool for predicting the potential detonation pressures and for estimating the composition limits of flammability for these systems based on empirical correlations between gas mixture thermodynamics and flammability for known systems. The present model uses the thermodynamic equilibrium to determine the reaction endpoint of a reactive gas mixture and uses detonation theory to estimate an upper bound to the pressure that could be generated upon ignition. The model described and documented in this report is an extended version of related models developed in 1992 and 1999

  17. Detonation Propagation in Slabs and Axisymmetric Rate Sticks

    Science.gov (United States)

    Romick, Christopher; Aslam, Tariq

    Insensitive high explosives (IHE) have many benefits; however, these IHEs exhibit longer reaction zones than more conventional high explosives (HE). This makes IHEs less ideal explosives and more susceptible to edge effects as well as other performance degradation issues. Thus, there is a resulting reduction in the detonation speed within the explosive. Many HE computational models, e. g. WSD, SURF, CREST, have shock-dependent reaction rates. This dependency places a high value on having an accurate shock speed. In the common practice of shock-capturing, there is ambiguity in the shock-state due to smoothing of the shock-front. Moreover, obtaining an accurate shock speed with shock-capturing becomes prohibitively computationally expensive in multiple dimensions. The use of shock-fitting removes the ambiguity of the shock-state as it is one of the boundaries. As such, the required resolution for a given error in the detonation speed is less than with shock-capturing. This allows for further insight into performance degradation. A two-dimensional shock-fitting scheme has been developed for unconfined slabs and rate sticks of HE. The HE modeling is accomplished by Euler equations utilizing several models with single-step irreversible kinetics in slab and rate stick geometries. Department of Energy - LANL.

  18. Deaggregation, Modification, and Developing Applications for Detonation Nanodiamond

    Science.gov (United States)

    Mochalin, Vadym

    2017-06-01

    Nanodiamond powder (ND) is one of the most promising materials for advanced composites and biomedical applications. It is also a commercial precursor for carbon nanoonions - material for high power micrometer size supercapacitors and potentially, Li-ion batteries. ND is produced by detonation of explosives with negative oxygen balance in a closed chamber, where extremely high pressures and temperatures develop during detonation. ND consists of diamond particles of 5 nm diameter, combining fully accessible large surface and rich and tailorable surface chemistry. ND has unique properties including optical, electrical, thermal, and mechanical, and is biocompatible and non-toxic. Due to numerous surface functional groups, ND has catalytic and electrochemical activity. Several techniques have been proposed for ND deaggregation based on milling with costly ceramic microbeads, leaving difficult to remove contaminations in the resulting ND suspension. We have recently discovered a novel, green technique for ND deaggregation using sonication in aqueous sodium chloride slurry. Upon completion of the process sodium chloride can be easily washed out with water leaving behind no contaminants and yielding stable single-digit ND colloids. Modification and development of applications for ND in composites, drug delivery, biomedical imaging, etc., will be also discussed.

  19. Spall behaviors of high purity copper under sweeping detonation

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Yang, E-mail: yangyanggroup@163.com [School of Material Science and Engineering, Central South University, Changsha 410083 (China); Institute of Fluid Physics, China Academy of Engineering Physics, Mianyang 621900 (China); National Key Laboratory of Explosion Science and Technology, Beijing Institute of Technology, Beijing 100081 (China); Key Laboratory of Nonferrous Metals Material Science and Engineering of Ministry of Education, Central South University, Changsha 410083 (China); Zhi-qiang, Peng; Xing-zhi, Chen [School of Material Science and Engineering, Central South University, Changsha 410083 (China); Key Laboratory of Nonferrous Metals Material Science and Engineering of Ministry of Education, Central South University, Changsha 410083 (China); Zhao-liang, Guo; Tie-gang, Tang; Hai-bo, Hu [Institute of Fluid Physics, China Academy of Engineering Physics, Mianyang 621900 (China); Qing-ming, Zhang [National Key Laboratory of Explosion Science and Technology, Beijing Institute of Technology, Beijing 100081 (China)

    2016-01-10

    Suites of sweeping detonation experiments were conducted to assess the spall behavior of high purity copper samples with different heat treatment histories. Incipient spall samples were obtained at different sweeping detonation condition. Metallographic and Electron Backscattered Diffraction (EBSD) analyses were performed on the soft-recovered samples. The effects of grain boundaries, grain size, crystal orientation and loading direction on the spall behaviors were discussed. Spall plane branching was found in the main spall plane of the damage samples. For similar microstructure, the area of voids increase with the increase of shock stress, and the coalescence of voids also become more obvious. Results from EBSD analysis show that the grain sizes were decreased and the grains were elongated along the direction of the plate width. Triple junctions composed of two or more general high angle boundaries are the preferred locations for intergranular damage. Voids prefer to nucleate in the grain boundaries composed of grain with high Taylor Factor (TF) than other grains. The damage areas in the grains with high TF are more severe. Boundaries close to perpendicular to the loading direction are more susceptible to void nucleation than the boundaries close to parallel to the loading direction, but the difference of voids nucleated in these two boundaries is less significant than the results obtained by plate impact experiment. It would be caused by the obliquity between the shock loading direction and the plate normal.

  20. Benign Lesions of The Vocal Fold

    Directory of Open Access Journals (Sweden)

    Ozgur Surmelioglu

    2013-02-01

    Full Text Available Benign lesions of vocal folds are common disorders. Fifty percent of patients who have sound complaints are found to have these lesions after endoscopic and stroboscopic examinations. Benign vocal fold diseases are primarily caused by vibratory trauma. However they may also occur as a result of viral infections and congenital causes. These lesions are often presented with the complaints of dysphonia. [Archives Medical Review Journal 2013; 22(1.000: 86-95

  1. Near-limit propagation of gaseous detonations in narrow annular channels

    Science.gov (United States)

    Gao, Y.; Ng, H. D.; Lee, J. H. S.

    2017-03-01

    New results on the near-limit behaviors of gaseous detonations in narrow annular channels are reported in this paper. Annular channels of widths 3.2 and 5.9 mm were made using circular inserts in a 50.8 mm-diameter external tube. The length of each annular channel was 1.8 m. Detonations were initiated in a steel driver tube where a small volume of a sensitive C2H2+ 2.5O2 mixture was injected to facilitate detonation initiation. A 2 m length of circular tube with a 50.8 mm diameter preceded the annular channel so that a steady Chapman-Jouguet (CJ) detonation was established prior to entering the annular channel. Four detonable mixtures of C2H2 {+} 2.5O2 {+} 85 % Ar, C2H2 {+} 2.5O2 {+} 70 % Ar, C3H8 {+} 5O2, and CH4 {+} 2O2 were used in the present study. Photodiodes spaced 10 cm throughout the length of both the annular channel and circular tube were used to measure the detonation velocity. In addition, smoked foils were inserted into the annular channel to monitor the cellular structure of the detonation wave. The results show that, well within the detonability limits, the detonation wave propagates along the channel with a small local velocity fluctuation and an average global velocity can be deduced. The average detonation velocity has a small deficit of 5-15 % far from the limits and the velocity rapidly decreases to 0.7V_{CJ}-0.8V_{CJ} when the detonation propagates near the limit. Subsequently, the fluctuation of local velocity also increases as the decreasing initial pressure approaches the limit. In the two annular channels used in this work, no galloping detonations were observed for both the stable and unstable mixtures tested. The present study also confirms that single-headed spinning detonation occurs at the limit, as in a circular tube, rather than the up and down "zig zag" mode in a two-dimensional, rectangular channel.

  2. Imaging malignant and apparent malignant transformation of benign gynaecological disease

    Energy Technology Data Exchange (ETDEWEB)

    Lee, A.Y.; Poder, L.; Qayyum, A.; Wang, Z.J.; Yeh, B.M. [Department of Radiology, University of California San Francisco, San Francisco, CA (United States); Coakley, F.V., E-mail: Fergus.Coakley@radiology.ucsf.ed [Department of Radiology, University of California San Francisco, San Francisco, CA (United States)

    2010-12-15

    Common benign gynaecological diseases, such as leiomyoma, adenomyosis, endometriosis, and mature teratoma, rarely undergo malignant transformation. Benign transformations that may mimic malignancy include benign metastasizing leiomyoma, massive ovarian oedema, decidualization of endometrioma, and rupture of mature teratoma. The aim of this review is to provide a contemporary overview of imaging findings in malignant and apparent malignant transformation of benign gynaecological disease.

  3. Numerical simulations of cellular detonation diffraction in a stable gaseous mixture

    Directory of Open Access Journals (Sweden)

    Jian Li

    2016-09-01

    Full Text Available In this paper, the diffraction phenomenon of gaseous cellular detonations emerging from a confined tube into a sudden open space is simulated using the reactive Euler equations with a two-step Arrhenius chemistry model. Both two-dimensional and axisymmetric configurations are used for modeling cylindrical and spherical expansions, respectively. The chemical parameters are chosen for a stable gaseous explosive mixture in which the cellular detonation structure is highly regular. Adaptive mesh refinement (AMR is used to resolve the detonation wave structure and its evolution during the transmission. The numerical results show that the critical channel width and critical diameter over the detonation cell size are about 13±1 and 25±1, respectively. These numerical findings are comparable with the experimental observation and confirm again that the critical channel width and critical diameter differ essentially by a factor close to 2, equal to the geometrical scaling based on front curvature theory. Unlike unstable mixtures where instabilities manifested in the detonation front structure play a significant role during the transmission, the present numerical results and the observed geometrical scaling provide again evidence that the failure of detonation diffraction in stable mixtures with a regular detonation cellular pattern is dominantly caused by the global curvature due to the wave divergence resulting in the global decoupling of the reaction zone with the expanding shock front.

  4. A Semi-analytic Criterion for the Spontaneous Initiation of Carbon Detonations in White Dwarfs

    International Nuclear Information System (INIS)

    Garg, Uma; Chang, Philip

    2017-01-01

    Despite over 40 years of active research, the nature of the white dwarf progenitors of SNe Ia remains unclear. However, in the last decade, various progenitor scenarios have highlighted the need for detonations to be the primary mechanism by which these white dwarfs are consumed, but it is unclear how these detonations are triggered. In this paper we study how detonations are spontaneously initiated due to temperature inhomogeneities, e.g., hotspots, in burning nuclear fuel in a simplified physical scenario. Following the earlier work by Zel’Dovich, we describe the physics of detonation initiation in terms of the comparison between the spontaneous wave speed and the Chapman–Jouguet speed. We develop an analytic expression for the spontaneous wave speed and utilize it to determine a semi-analytic criterion for the minimum size of a hotspot with a linear temperature gradient between a peak and base temperature for which detonations in burning carbon–oxygen material can occur. Our results suggest that spontaneous detonations may easily form under a diverse range of conditions, likely allowing a number of progenitor scenarios to initiate detonations that burn up the star.

  5. Simulation of hydrogen deflagration and detonation in a BWR reactor building

    International Nuclear Information System (INIS)

    Manninen, M.; Silde, A.; Lindholm, I.; Huhtanen, R.; Sjoevall, H.

    2002-01-01

    A systematic study was carried out to investigate the hydrogen behaviour in a BWR reactor building during a severe accident. BWR core contains a large amount of Zircaloy and the containment is relatively small. Because containment leakage cannot be totally excluded, hydrogen can build up in the reactor building, where the atmosphere is normal air. The objective of the work was to investigate, whether hydrogen can form flammable and detonable mixtures in the reactor building, evaluate the possibility of onset of detonation and assess the pressure loads under detonation conditions. The safety concern is, whether the hydrogen in the reactor building can detonate and whether the external detonation can jeopardize the containment integrity. The analysis indicated that the possibility of flame acceleration and deflagration-to-detonation transition (DDT) in the reactor building could not be ruled out in case of a 20 mm 2 leakage from the containment. The detonation analyses indicated that maximum pressure spike of about 7 MPa was observed in the reactor building room selected for the analysis

  6. A Semi-analytic Criterion for the Spontaneous Initiation of Carbon Detonations in White Dwarfs

    Energy Technology Data Exchange (ETDEWEB)

    Garg, Uma; Chang, Philip, E-mail: umagarg@uwm.edu, E-mail: chang65@uwm.edu [Department of Physics, University of Wisconsin-Milwaukee, 3135 North Maryland Avenue, Milwaukee, WI 53211 (United States)

    2017-02-20

    Despite over 40 years of active research, the nature of the white dwarf progenitors of SNe Ia remains unclear. However, in the last decade, various progenitor scenarios have highlighted the need for detonations to be the primary mechanism by which these white dwarfs are consumed, but it is unclear how these detonations are triggered. In this paper we study how detonations are spontaneously initiated due to temperature inhomogeneities, e.g., hotspots, in burning nuclear fuel in a simplified physical scenario. Following the earlier work by Zel’Dovich, we describe the physics of detonation initiation in terms of the comparison between the spontaneous wave speed and the Chapman–Jouguet speed. We develop an analytic expression for the spontaneous wave speed and utilize it to determine a semi-analytic criterion for the minimum size of a hotspot with a linear temperature gradient between a peak and base temperature for which detonations in burning carbon–oxygen material can occur. Our results suggest that spontaneous detonations may easily form under a diverse range of conditions, likely allowing a number of progenitor scenarios to initiate detonations that burn up the star.

  7. Shock wave and flame front induced detonation in a rapid compression machine

    Science.gov (United States)

    Wang, Y.; Qi, Y.; Xiang, S.; Mével, R.; Wang, Z.

    2018-05-01

    The present study focuses on one mode of detonation initiation observed in a rapid compression machine (RCM). This mode is referred to as shock wave and flame front-induced detonation (SWFID). Experimental high-speed imaging and two-dimensional numerical simulations with skeletal chemistry are combined to unravel the dominant steps of detonation initiation under SWFID conditions. It is shown that the interaction between the shock wave generated by the end-gas auto-ignition and the spherical flame creates a region of high pressure and temperature which enables the acceleration of the flame front and the detonation onset. The experimental observation lacks adequate spatial and temporal resolution despite good reproducibility of the detonation onset. Based on the numerical results, phenomenological interpretation of the event within the framework of shock wave refraction indicates that the formation of a free-precursor shock wave at the transition between regular and irregular refraction may be responsible for detonation onset. The present results along with previous findings on shock wave reflection-induced detonation in the RCM indicate that super-knock occurs after the interaction of the shock wave generated by end-gas auto-ignition with the RCM walls, preignition flame, or another shock wave.

  8. Thermodynamic Calculations of Hydrogen-Oxygen Detonation Parameters for Various Initial Pressures

    Science.gov (United States)

    Bollinger, Loren E.; Edse, Rudolph

    1961-01-01

    Composition, temperature, pressure and density behind a stable detonation wave and its propagation rate have been calculated for seven hydrogen-oxygen mixture at 1, 5, 25 and 100 atm initial pressure, and at an initial temperature of 40C. For stoichiometric mixtures that calculations also include an initial temperature of 200C. According to these calculations the detonation velocities of hydrogen-oxygen mixtures increase with increasing initial pressure, but decrease slightly when the initial temperature is raised from 40 to 200 C. The calculated detonation velocities agree satisfactorily with values determined experimentally. These values will be published in the near future.

  9. On investigation of optical and spin properties of NV centers in aggregates of detonation nanodiamonds

    Science.gov (United States)

    Bolshedvorskii, S. V.; Vorobyov, V. V.; Soshenko, V. V.; Zeleneev, A.; Sorokin, V. N.; Smolyaninov, A. N.; Akimov, A. V.

    2018-02-01

    Quickly developing application of nitrogen-vacancy color centers in diamond sets demands on cheap and high optical and spin properties nanodiamonds. Among other types, detonation nanodiamonds are easiest for production but often show no NV color centers inside. In this work we show, that aggregates of detonation nanodiamonds could be as good, or even better in terms of brightness and spin properties, than more expensive single crystal nanodiamonds. This way aggregates of detonation nanodiamonds could efficiently serve as cheap and bright source of single photon radiation or sensitive element of biocompatible sensor.

  10. Linear stability analysis of detonations via numerical computation and dynamic mode decomposition

    KAUST Repository

    Kabanov, Dmitry; Kasimov, Aslan R.

    2018-01-01

    We introduce a new method to investigate linear stability of gaseous detonations that is based on an accurate shock-fitting numerical integration of the linearized reactive Euler equations with a subsequent analysis of the computed solution via the dynamic mode decomposition. The method is applied to the detonation models based on both the standard one-step Arrhenius kinetics and two-step exothermic-endothermic reaction kinetics. Stability spectra for all cases are computed and analyzed. The new approach is shown to be a viable alternative to the traditional normal-mode analysis used in detonation theory.

  11. Preliminary investigation for the development of surrogate debris from nuclear detonations in marine-urban environments

    International Nuclear Information System (INIS)

    Seybert, A.G.; Auxier II, J.D.; University of Tennessee, Knoxville, TN; Hall, H.L.; University of Tennessee, Knoxville, TN; University of Tennessee, Knoxville, TN

    2017-01-01

    Since no nuclear weapon surface detonations have occurred in urban harbor environments, the nuclear forensic community has no actual debris from which to develop and validate analytical methods for radiochemistry analysis, making the development of surrogate debris representative of this a marine-urban detonation a vital undertaking. This work seeks to build a robust model that accounts for natural and manmade environmental variations in harbor environments and vessel compositions to statistically define the elemental composition of vaporized debris from a marine-urban nuclear detonation. This initial work is necessary for follow-on neutron-activation and debris formation analysis. (author)

  12. Linear stability analysis of detonations via numerical computation and dynamic mode decomposition

    KAUST Repository

    Kabanov, Dmitry I.

    2017-12-08

    We introduce a new method to investigate linear stability of gaseous detonations that is based on an accurate shock-fitting numerical integration of the linearized reactive Euler equations with a subsequent analysis of the computed solution via the dynamic mode decomposition. The method is applied to the detonation models based on both the standard one-step Arrhenius kinetics and two-step exothermic-endothermic reaction kinetics. Stability spectra for all cases are computed and analyzed. The new approach is shown to be a viable alternative to the traditional normal-mode analysis used in detonation theory.

  13. Structure of Biocompatible Coatings Produced from Hydroxyapatite Nanoparticles by Detonation Spraying

    Science.gov (United States)

    Nosenko, Valentyna; Strutynska, Nataliia; Vorona, Igor; Zatovsky, Igor; Dzhagan, Volodymyr; Lemishko, Sergiy; Epple, Matthias; Prymak, Oleg; Baran, Nikolai; Ishchenko, Stanislav; Slobodyanik, Nikolai; Prylutskyy, Yuriy; Klyui, Nickolai; Temchenko, Volodymyr

    2015-12-01

    Detonation-produced hydroxyapatite coatings were studied by scanning electron microscopy (SEM), X-ray powder diffraction (XRD), Raman spectroscopy, and electron paramagnetic resonance (EPR) spectroscopy. The source material for detonation spraying was a B-type carbonated hydroxyapatite powder. The coatings consisted of tetracalcium phosphate and apatite. The ratio depended slightly on the degree of crystallinity of the initial powder and processing parameters of the coating preparation. The tetracalcium phosphate phase was homogeneous; the apatite phase contained defects localized on the sixfold axis and consisted of hydroxyapatite and oxyapatite. Technological factors contributing to the transformation of hydroxyapatite powder structure during coating formation by detonation spraying are discussed.

  14. Linear stability analysis of detonations via numerical computation and dynamic mode decomposition

    KAUST Repository

    Kabanov, Dmitry

    2018-03-20

    We introduce a new method to investigate linear stability of gaseous detonations that is based on an accurate shock-fitting numerical integration of the linearized reactive Euler equations with a subsequent analysis of the computed solution via the dynamic mode decomposition. The method is applied to the detonation models based on both the standard one-step Arrhenius kinetics and two-step exothermic-endothermic reaction kinetics. Stability spectra for all cases are computed and analyzed. The new approach is shown to be a viable alternative to the traditional normal-mode analysis used in detonation theory.

  15. Influence of external-detonation-generated plasmas on the performance of semi-confined explosive charges

    Energy Technology Data Exchange (ETDEWEB)

    Udy, L.L.

    1979-02-01

    External-detonation-generated plasmas, highly ionized zones of reacting material ejected from the surface of detonating explosive charges, are shown to be the cause of channel desensitization, i.e., the self-quenching of a detonating explosive column loaded in a borehole with an air annulus between the explosive and the borehole wall. The effects of this phenomenon on several explosive compositions and types are demonstrated and discussed. The explosives tested include aluminum-sensitized and explosive-sensitized slurries, ANFO, liquid explosives and dynamites. Various techniques are described that can be used to reduce or eliminate the plasma effect.

  16. SSS: A code for computing one dimensional shock and detonation wave propagation

    International Nuclear Information System (INIS)

    Sun Chengwei

    1986-01-01

    The one-dimensional hydrodynamic code SSS for shock and detonation wave propagation in inert and reactive media is described. The elastic-plastic-hydrodynamic model and four burn techniques (the Arrhenius law, C-J volume, sharp shock and Forest Fire) are used. There are HOM and JWL options for the state equation of detonation products. Comparing with the SIN code published by LANL, the SSS code has several new options: laser effects, blast waves, diverging and instantaneous detonation waves with arbitrary initiation positions. Two examples are given to compare the SSS and SIN calculations with the experimental data

  17. High speed radiometric measurements of IED detonation fireballs

    Science.gov (United States)

    Spidell, Matthew T.; Gordon, J. Motos; Pitz, Jeremey; Gross, Kevin C.; Perram, Glen P.

    2010-04-01

    Continuum emission is predominant in fireball spectral phenomena and in some demonstrated cases, fine detail in the temporal evolution of infrared spectral emissions can be used to estimate size and chemical composition of the device. Recent work indicates that a few narrow radiometric bands may reveal forensic information needed for the explosive discrimination and classification problem, representing an essential step in moving from "laboratory" measurements to a rugged, fieldable system. To explore phenomena not observable in previous experiments, a high speed (10μs resolution) radiometer with four channels spanning the infrared spectrum observed the detonation of nine home made explosive (HME) devices in the 0.98) using blast model functional forms, suggesting that energy release could be estimated from single-pixel radiometric detectors. Comparison of radiometer-derived fireball size with FLIR infrared imagery indicate the Planckian intensity size estimates are about a factor of two smaller than the physical extent of the fireball.

  18. Efficient numerical simulation of the deflagration-to-detonation transition

    International Nuclear Information System (INIS)

    Ettner, Florian Anton

    2013-01-01

    In order to improve safety analyses of nuclear power plants, it is necessary to investigate if hydrogen-air mixtures (created in severe accidents) burn in a deflagrative manner or whether a deflagration-to-detonation transition (DDT) occurs. In this work a CFD solver has been developed for the simulation of a complete combustion process including DDT. The density-based solver incorporates a deflagration model and an auto-ignition model which are coupled via a progress variable. The application to both homogeneous and inhomogeneous mixtures shows very good agreement with experiments. Depending on the boundary conditions the presence of a hydrogen concentration gradient can either increase or decrease the probability of DDT when compared to a homogeneous mixture. Under certain circumstances extremely high pressure loads occur even in areas of low hydrogen content. This should be taken into consideration in future safety analyses.

  19. Oblique interactions of detonation waves with explosive/metal interfaces

    International Nuclear Information System (INIS)

    Walsh, J.M.

    1982-12-01

    The interaction of a detonation wave with an explosive/metal interface is considered. Theoretical models are discussed, and calculated results are given for PBX 9501 onto uranium, tantalum, copper, 304 stainless steel, aluminum, and nickel. For PBX 9501 onto aluminum and copper, regular shock reflection (in the PBX 9501) at small angles changes to regular rarefaction reflection (Prandtl-Meyer flow) at large angles, and the curve of metal-shock pressure vs incidence angle is smooth. For the other metals, there is a discontinuity in shock pressure where low-angle, regular reflection transists to Mach reflection, and a smaller discontinuity where the Mach reflection changes back to high-angle regular reflection

  20. Formation mechanisms and characteristics of transition patterns in oblique detonations

    Science.gov (United States)

    Miao, Shikun; Zhou, Jin; Liu, Shijie; Cai, Xiaodong

    2018-01-01

    The transition structures of wedge-induced oblique detonation waves (ODWs) in high-enthalpy supersonic combustible mixtures are studied with two-dimensional reactive Euler simulations based on the open-source program AMROC (Adaptive Mesh Refinement in Object-oriented C++). The formation mechanisms of different transition patterns are investigated through theoretical analysis and numerical simulations. Results show that transition patterns of ODWs depend on the pressure ratio Pd/Ps, (Pd, Ps are the pressure behind the ODW and the pressure behind the induced shock, respectively). When Pd/Ps > 1.3, an abrupt transition occurs, while when Pd/Ps 1.02Φ∗ (Φ∗ is the critical velocity ratio calculated with an empirical formula).

  1. Characterization Of High Explosives Detonations Via Laser-Induced Plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Villa-Aleman, E. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2015-10-08

    One objective of the Department of Energy’s National Security Administration is to develop technologies that can help the United States government to detect foreign nuclear weapons development activities. The realm of high explosive (HE) experiments is one of the key areas to assess the nuclear ambitions of a country. SRNL has participated in the collection of particulates from HE experiments and characterized the material with the purpose to correlate particulate matter with HE. Since these field campaigns are expensive, on-demand simulated laboratory-scale explosion experiments are needed to further our knowledge of the chemistry and particle formation in the process. Our goal is to develop an experimental test bed in the laboratory to test measurement concepts and correlate particle formation processes with the observables from the detonation fireball. The final objective is to use this knowledge to tailor our experimental setups in future field campaigns. The test bed uses pulsed laser-induced plasmas to simulate micro-explosions, with the intent to study the temporal behavior of the fireball observed in field tests. During FY15, a plan was prepared and executed which assembled two laser ablation systems, procured materials for study, and tested a Step-Scan Fourier Transform Infrared Spectrometer (SS-FTIR). Designs for a shadowgraph system for shock wave analysis, design for a micro-particulate collector from ablated pulse were accomplished. A novel spectroscopic system was conceived and a prototype system built for acquisition of spectral/temporal characterization of a high speed event such as from a high explosive detonation. Experiments and analyses will continue into FY16.

  2. Axisymmetric Numerical Modeling of Pulse Detonation Rocket Engines

    Science.gov (United States)

    Morris, Christopher I.

    2005-01-01

    Pulse detonation rocket engines (PDREs) have generated research interest in recent years as a chemical propulsion system potentially offering improved performance and reduced complexity compared to conventional rocket engines. The detonative mode of combustion employed by these devices offers a thermodynamic advantage over the constant-pressure deflagrative combustion mode used in conventional rocket engines and gas turbines. However, while this theoretical advantage has spurred considerable interest in building PDRE devices, the unsteady blowdown process intrinsic to the PDRE has made realistic estimates of the actual propulsive performance problematic. The recent review article by Kailasanath highlights some of the progress that has been made in comparing the available experimental measurements with analytical and numerical models. In recent work by the author, a quasi-one-dimensional, finite rate chemistry CFD model was utilized to study the gasdynamics and performance characteristics of PDREs over a range of blowdown pressure ratios from 1-1000. Models of this type are computationally inexpensive, and enable first-order parametric studies of the effect of several nozzle and extension geometries on PDRE performance over a wide range of conditions. However, the quasi-one-dimensional approach is limited in that it cannot properly capture the multidimensional blast wave and flow expansion downstream of the PDRE, nor can it resolve nozzle flow separation if present. Moreover, the previous work was limited to single-pulse calculations. In this paper, an axisymmetric finite rate chemistry model is described and utilized to study these issues in greater detail. Example Mach number contour plots showing the multidimensional blast wave and nozzle exhaust plume are shown. The performance results are compared with the quasi-one-dimensional results from the previous paper. Both Euler and Navier-Stokes solutions are calculated in order to determine the effect of viscous

  3. Benign multicystic peritoneal mesothelioma: a case report

    Directory of Open Access Journals (Sweden)

    Papapaulou Leonidas

    2010-11-01

    Full Text Available Abstract Introduction We report the case of a patient with a benign multicystic peritoneal mesothelioma and describe its appearance on computed tomography scans and ultrasonography, in correlation with gross clinical and pathological findings. Case presentation A 72-year-old Caucasian woman presented to our emergency department with acute abdomen signs and symptoms. A clinical examination revealed a painful palpable mass in her left abdomen. Abdominal ultrasonography and computed tomography demonstrated the presence of a large cystic mass in her left upper abdomen, adjacent to her left hemidiaphragm. The lower border of the mass extended to the upper margin of her pelvis. A complete resection of the lesion was performed. Pathological analysis showed a benign multicystic peritoneal mesothelioma. Conclusions Benign multicystic peritoneal mesothelioma is a rare lesion with a non-specific appearance on imaging. Its diagnosis always requires pathological analysis.

  4. Pharmacological treatment of the benign prostatic hyperplasia

    International Nuclear Information System (INIS)

    Perez Guerra, Yohani; Molina Cuevas, Vivian; Oyarzabal Yera, Ambar; Mas Ferreiro, Rosa

    2011-01-01

    Benign prostatic hyperplasia is a common disease in over 50 years-old men consisting in uncontrolled and benign growth of prostatic gland that leads to lower urinary tract symptoms. The etiology of benign prostatic hyperplasia is multifactoral involving the increased conversion of testosterone in dihydrotestosterone by the prostatic 5α-reductase action, which brought about events that encourage the prostate growth (static component) and the increase of the bladder and prostate smooth muscle tone (dynamic component) regulated by the aα 1 -adrenoceptors (ADR). The pharmacological treatment of the benign prostatic hyperplasia includes the prostatic 5aα-reductase inhibitors, the aα 1 -adrenoreceptor blockers, their combined therapy and the phytotherapy. This paper was aimed at presenting the most relevant aspects of the pharmacology of drugs used for treating the benign prostatic hyperplasia, and providing elements to analyze their efficacy, safety and tolerability. To this end, a review was made of the different drugs for the treatment of this pathology and they were grouped according to their mechanism of action. Natural products were included as lipid extracts from Serenoa repens and Pygeum africanum as well as D-004, a lipid extract from Roystonea regia fruits, with proved beneficial effects on the main etiological factors of benign prostatic hyperplasia. D-004 is a prostatic 5a-reductase inhibitor, an aα 1 -adrenoceptor antagonist, aα 5-lipooxygenase inhibitor and has antioxidant action, all of which reveals a multifactoral mechanism. The results achieved till now indicate that D-004 is a safe and well-tolerated product

  5. Benign breast lesions in Eastern Nigeria

    International Nuclear Information System (INIS)

    Anyikam, A.; Nzegwn, Martin A.; Olusina, Daniel B.; Okoye, I.; Ozumba, Ben C.

    2008-01-01

    Objective was to characterize benign breast diseases in Eastern Nigeria and to highlight the age variations of these lesions as base line data. The Department of Morbid Anatomy, University of Nigeria Teaching Hospital, Enugu caters for over 30 million African blacks and receives 2000 surgical pathology specimens yearly. Seven hundred and twenty-two benign breast specimens were analyzed over 5 years from Ist January 2000 to 31 December 2004, out of 1050 breast samples received. Of 1050 breast specimens received, 722 (68.8%) were benign. Fibroadenoma was the most common lesion with 318 cases (44%), occurring at a mean age of 16-32 years. Next were fibrocystic changes with 165 cases (22.9%) at a mean age of 23-45 years. Normal breast in the axillary tail region was seen in 32 cases (4.4%), represented as no pathology, with a mean presentation age of 20-46 years. Low grade Phyllodes tumor had 28 cases (3.9%), presenting at an average mean age of 17-32 years. Lactating adenoma had 19 (2.6%) cases. Other lesions made up less than 3% each. Benign breast lesions peaked at the 20-24 age range and then declined. Most were females. Benign breast lesions occur more frequently than malignant breast lesions with a ratio of 2.3:1 and were presented 20 years earlier than their malignant counterparts. Fibroadenoma was the most common benign lesions followed by fibrocystic disease, similar to the findings in Western Nigeria. In Northern Nigeria, fibrocystic breast disease was more common. (author)

  6. Carbon Condensation during High Explosive Detonation with Time Resolved Small Angle X-ray Scattering

    Science.gov (United States)

    Hammons, Joshua; Bagge-Hansen, Michael; Nielsen, Michael; Lauderbach, Lisa; Hodgin, Ralph; Bastea, Sorin; Fried, Larry; May, Chadd; Sinclair, Nicholas; Jensen, Brian; Gustavsen, Rick; Dattelbaum, Dana; Watkins, Erik; Firestone, Millicent; Ilavsky, Jan; van Buuren, Tony; Willey, Trevor; Lawrence Livermore National Lab Collaboration; Los Alamos National Laboratory Collaboration; Washington State University/Advanced Photon Source Team

    Carbon condensation during high-energy detonations occurs under extreme conditions and on very short time scales. Understanding and manipulating soot formation, particularly detonation nanodiamond, has attracted the attention of military, academic and industrial research. An in-situ characterization of these nanoscale phases, during detonation, is highly sought after and presents a formidable challenge even with today's instruments. Using the high flux available with synchrotron X-rays, pink beam small angle X-ray scattering is able to observe the carbon phases during detonation. This experimental approach, though powerful, requires careful consideration and support from other techniques, such as post-mortem TEM, EELS and USAXS. We present a comparative survey of carbon condensation from different CHNO high explosives. This work was performed under the auspices of the US DOE by LLNL under Contract DE-AC52-07NA27344.

  7. OGLE-2013-SN-079: A LONELY SUPERNOVA CONSISTENT WITH A HELIUM SHELL DETONATION

    International Nuclear Information System (INIS)

    Inserra, C.; Sim, S. A.; Smartt, S. J.; Nicholl, M.; Jerkstrand, A.; Chen, T.-W.; Wyrzykowski, L.; Fraser, M.; Blagorodnova, N.; Campbell, H.; Shen, K. J.; Gal-Yam, A.; Howell, D. A.; Valenti, S.; Maguire, K.; Mazzali, P.; Bersier, D.; Taubenberger, S.; Benitez-Herrera, S.; Elias-Rosa, N.

    2015-01-01

    We present observational data for a peculiar supernova discovered by the OGLE-IV survey and followed by the Public ESO Spectroscopic Survey for Transient Objects. The inferred redshift of z = 0.07 implies an absolute magnitude in the rest-frame I-band of M I ∼ –17.6 mag. This places it in the luminosity range between normal Type Ia SNe and novae. Optical and near infrared spectroscopy reveal mostly Ti and Ca lines, and an unusually red color arising from strong depression of flux at rest wavelengths <5000 Å. To date, this is the only reported SN showing Ti-dominated spectra. The data are broadly consistent with existing models for the pure detonation of a helium shell around a low-mass CO white dwarf and ''double-detonation'' models that include a secondary detonation of a CO core following a primary detonation in an overlying helium shell

  8. Detonation Nanodiamond Toxicity in Human Airway Epithelial Cells Is Modulated by Air Oxidation

    Science.gov (United States)

    Detonational nanodiamonds (DND), a nanomaterial with an increasing range of industrial and biomedical applications, have previously been shown to induce a pro-inflammatory response in cultured human airway epithelial cells (HAEC). We now show that surface modifications induced by...

  9. Analysis of GPS Satellite Allocation for the United States Nuclear Detonation Detection System (USNDS)

    National Research Council Canada - National Science Library

    Bell, Aaron

    2002-01-01

    ...) satellites to detect atmospheric nuclear detonations. Though there are currently over 24 operational GPS satellites, USNDS ground based antennas are only capable of actively monitoring 24 satellites at a time...

  10. Necessary conditions for the initiation and propagation of nuclear-detonation waves in plane atmospheres

    International Nuclear Information System (INIS)

    Weaver, T.A.; Wood, L.

    1979-01-01

    The basic conditions for the initiation of a nuclear-detonation wave in an atmosphere having plane symmetry (e.g., a thin, layered fluid envelope on a planet or star) are developed. Two classes of such a detonation are identified: those in which the temperature of the plasma is comparable to that of the electromagnetic radiation permeating it, and those in which the temperature of the plasma is much higher. Necessary conditions are developed for the propagation of such detonation waves for an arbitrarily great distance. The contribution of fusion chain reactions to these processes is evaluated. By means of these considerations, it is shown that neither the atmosphere nor oceans of the Earth may be made to undergo propagating nuclear detonation under any circumstances

  11. Research on laser detonation pulse circuit with low-power based on super capacitor

    Science.gov (United States)

    Wang, Hao-yu; Hong, Jin; He, Aifeng; Jing, Bo; Cao, Chun-qiang; Ma, Yue; Chu, En-yi; Hu, Ya-dong

    2018-03-01

    According to the demand of laser initiating device miniaturization and low power consumption of weapon system, research on the low power pulse laser detonation circuit with super capacitor. Established a dynamic model of laser output based on super capacitance storage capacity, discharge voltage and programmable output pulse width. The output performance of the super capacitor under different energy storage capacity and discharge voltage is obtained by simulation. The experimental test system was set up, and the laser diode of low power pulsed laser detonation circuit was tested and the laser output waveform of laser diode in different energy storage capacity and discharge voltage was collected. Experiments show that low power pulse laser detonation based on super capacitor energy storage circuit discharge with high efficiency, good transient performance, for a low power consumption requirement, for laser detonation system and low power consumption and provide reference light miniaturization of engineering practice.

  12. Detonation mode and frequency analysis under high loss conditions for stoichiometric propane-oxygen

    KAUST Repository

    Jackson, Scott; Lee, Bok Jik; Shepherd, Joseph E.

    2016-01-01

    The propagation characteristics of galloping detonations were quantified with a high-time-resolution velocity diagnostic. Combustion waves were initiated in 30-m lengths of 4.1-mm inner diameter transparent tubing filled with stoichiometric propane

  13. Fine Tuning the CJ Detonation Speed of a High Explosive products Equation of State

    Energy Technology Data Exchange (ETDEWEB)

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

    2017-05-12

    For high explosive (HE) simulations, inaccuracies of a per cent or two in the detonation wave speed can result from not suficiently resolving the reaction zone width or from small inaccuracies in calibrating the products equation of state (EOS) or from variation of HE lots. More accurate detonation speeds can be obtained by ne tuning the equation of state to compensate. Here we show that two simple EOS transformations can be used to adjust the CJ detonation speed by a couple of per cent with minimal effect on the CJ release isentrope. The two transformations are (1) a shift in the energy origin and (2) a linear scaling of the speci c volume. The effectiveness of the transformations is demonstrated with simulations of the cylinder test for PBX 9502 starting with a products EOS for which the CJ detonation speed is 1 per cent too low.

  14. OGLE-2013-SN-079: A LONELY SUPERNOVA CONSISTENT WITH A HELIUM SHELL DETONATION

    Energy Technology Data Exchange (ETDEWEB)

    Inserra, C.; Sim, S. A.; Smartt, S. J.; Nicholl, M.; Jerkstrand, A.; Chen, T.-W. [Astrophysics Research Centre, School of Mathematics and Physics, Queens University Belfast, Belfast BT7 1NN (United Kingdom); Wyrzykowski, L. [University of Warsaw, Astronomical Observatory, Al. Ujazdowskie 400-478 Warszawa (Poland); Fraser, M.; Blagorodnova, N.; Campbell, H. [Institute of Astronomy, University of Cambridge, Madingley Road, CB3 0HA Cambridge (United Kingdom); Shen, K. J. [Department of Astronomy and Theoretical Astrophysics Center, University of California, Berkeley, CA 94720 (United States); Gal-Yam, A. [Benoziyo Center for Astrophysics, Weizmann Institute of Science, 76100 Rehovot (Israel); Howell, D. A.; Valenti, S. [Las Cumbres Observatory Global Telescope Network, 6740 Cortona Drive, Suite 102 Goleta, CA 93117 (United States); Maguire, K. [European Southern Observatory for Astronomical Research in the Southern Hemisphere (ESO), Karl-Schwarzschild-Str. 2, 85748 Garching b. Munchen (Germany); Mazzali, P.; Bersier, D. [Astrophysics Research Institute, Liverpool John Moores University, Liverpool (United Kingdom); Taubenberger, S.; Benitez-Herrera, S. [Max-Planck-Institut für Astrophysik, Karl-Schwarzschild-Str. 1, 85741 Garching (Germany); Elias-Rosa, N., E-mail: c.inserra@qub.ac.uk [INAF - Osservatorio Astronomico di Padova, Vicolo dell' Osservatorio 5, I-35122 Padova (Italy); and others

    2015-01-20

    We present observational data for a peculiar supernova discovered by the OGLE-IV survey and followed by the Public ESO Spectroscopic Survey for Transient Objects. The inferred redshift of z = 0.07 implies an absolute magnitude in the rest-frame I-band of M{sub I} ∼ –17.6 mag. This places it in the luminosity range between normal Type Ia SNe and novae. Optical and near infrared spectroscopy reveal mostly Ti and Ca lines, and an unusually red color arising from strong depression of flux at rest wavelengths <5000 Å. To date, this is the only reported SN showing Ti-dominated spectra. The data are broadly consistent with existing models for the pure detonation of a helium shell around a low-mass CO white dwarf and ''double-detonation'' models that include a secondary detonation of a CO core following a primary detonation in an overlying helium shell.

  15. Confined detonations with cylindrical and spherical symmetry; Detonaciones confinadas con simetria esferica y cilindrica

    Energy Technology Data Exchange (ETDEWEB)

    Linan, A; Lecuona, A

    1979-07-01

    An imploding spherical or cylindrical detonation, starting in the interface of the detonantion with an external inert media, used as a reflector, creates on it a strong shock wave moving outward from the interface. An initially weak shock wave appears in the detonated media that travels toward the center, and it could reach the detonation wave, enforcing it in its process of implosion. To describe the fluid field, the Euler s equations are solved by means of expansions valid for the early stages of the process. Isentropic of the type P/p{gamma}-K for the detonated and compressed inert media are used. For liquid or solid reflectors a more appropriate equation is used. (Author) 8 refs.

  16. The role of multidimensional instabilities in direct initiation of gaseous detonations in free space

    KAUST Repository

    Shen, Hua; Parsani, Matteo

    2017-01-01

    We numerically investigate the direct initiation of detonations driven by the propagation of a blast wave into a unconfined gaseous combustible mixture to study the role played by multidimensional instabilities in direct initiation of stable

  17. Failure modes of a concrete nuclear-containment building subjected to hydrogen detonation

    International Nuclear Information System (INIS)

    Fugelso, L.E.; Butler, T.A.

    1983-01-01

    Calculated response for the Indian Point reactor containment building to static internal pressure and one case of a dynamic pressure representing hydrogen combustion and detonation are presented. Comparison of the potential failure modes is made. 9 figures

  18. Imaging of nontraumatic benign splenic lesions

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Jin Young; Kim, Eun Kyung; Chung, Jae Joon; Kim, Myeong Jin; Lee, Jong Tae; Yoo, Hyung Sik; Kim, Seong Joon [Yonsei Univ. College of Medicine Research Institute of Radiological Science, Seoul (Korea, Republic of); Kim, Lu Ci A [Yonsei Univ. College of Medicine, Seoul (Korea, Republic of)

    1999-04-01

    The spleen is one of the largest organ in the reticuloendothelial system and plays an important role in the activation of immune response. It is the organ most commonly injured after blunt abdominal trauma, and malignant lesions such as lymphoma, or these due to metastasis, occur not infrequently. Even so, it is ignored even in abdominal ultrasonography. Some benign splenic lesions, however can cause severe symptoms and result in high mortality, and their accurate diagnosis is therefore essential. This study describes the imaging findings and histopathologic features of various nontraumatic benign splenic lesions.

  19. Imaging of nontraumatic benign splenic lesions

    International Nuclear Information System (INIS)

    Choi, Jin Young; Kim, Eun Kyung; Chung, Jae Joon; Kim, Myeong Jin; Lee, Jong Tae; Yoo, Hyung Sik; Kim, Seong Joon; Kim, Lu Ci A

    1999-01-01

    The spleen is one of the largest organ in the reticuloendothelial system and plays an important role in the activation of immune response. It is the organ most commonly injured after blunt abdominal trauma, and malignant lesions such as lymphoma, or these due to metastasis, occur not infrequently. Even so, it is ignored even in abdominal ultrasonography. Some benign splenic lesions, however can cause severe symptoms and result in high mortality, and their accurate diagnosis is therefore essential. This study describes the imaging findings and histopathologic features of various nontraumatic benign splenic lesions

  20. Benign Cystic Mesothelioma Misdiagnosed as Peritoneal Carcinomatosis

    Directory of Open Access Journals (Sweden)

    Hyun Deok Shin

    2016-04-01

    Full Text Available Benign cystic mesothelioma (BCM is a rare benign disease that forms multicystic masses in the abdomen, pelvis, and retroperitoneum. It occurs predominantly in young to middle-aged women. The majority of cases were associated with a history of abdominal or pelvic operation, a history of endometriosis, and pelvic inflammatory disease. We present a unique case of BCM which is different to the previous cases. The patient was a 52-year-old man showing features of peritoneal carcinomatosis accompanied by ascites on abdominal computed tomography scans. We herein report a case of BCM misdiagnosed with peritoneal carcinomatosis.

  1. The decline of hysterectomy for benign disease.

    LENUS (Irish Health Repository)

    Horgan, R P

    2012-01-31

    Hysterectomy is one of the most common gynaecological surgical procedures performed but there appears to be a decline in the performance of this procedure in Ireland in recent times. We set out to establish the extent of the decline of hysterectomy and to explore possible explanations. Data for hysterectomy for benign disease from Ireland was obtained from the Hospital In-Patient Enquiry Scheme (HIPE) section of the Economic and Social Research Institute for the years 1999 to 2006. The total number of hysterectomies performed for benign disease showed a consistent decline during this time. There was a 36% reduction in the number of abdominal hysterectomy procedures performed.

  2. Prediction of detonation and JWL eos parameters of energetic materials using EXPLO5 computer code

    CSIR Research Space (South Africa)

    Peter, Xolani

    2016-09-01

    Full Text Available Ballistic Organization Cape Town, South Africa 27-29 September 2016 1 PREDICTION OF DETONATION AND JWL EOS PARAMETERS OF ENERGETIC MATERIALS USING EXPLO5 COMPUTER CODE X. Peter*, Z. Jiba, M. Olivier, I.M. Snyman, F.J. Mostert and T.J. Sono.... Nowadays many numerical methods and programs are being used for carrying out thermodynamic calculations of the detonation parameters of condensed explosives, for example a BKW Fortran (Mader, 1967), Ruby (Cowperthwaite and Zwisler, 1974) TIGER...

  3. Determination of favorable conditions of detonation in liquid and solid substance mixtures

    International Nuclear Information System (INIS)

    Aubeau, Raymond; Carles, Maurice; Cochet Muchy, Bernard; Ducouret, Andre

    1976-03-01

    Theoretical methods or testing techniques may be employed to provide for possible detonations of chemical substances capable of interreactions. The theoretical methods are based upon the determination of the specific energy of possible mixtures and the system geometry. But the testing techniques are the only ones to insure whether a given mixture may detonate, deflagrate or to be inert. Different possible examples are given [fr

  4. Shock-to-detonation transition of RDX and NTO based composite high explosives: experiments and modeling

    Science.gov (United States)

    Baudin, Gerard; Roudot, Marie; Genetier, Marc

    2013-06-01

    Composite HMX and NTO based high explosives (HE) are widely used in ammunitions. Designing modern warheads needs robust and reliable models to compute shock ignition and detonation propagation inside HE. Comparing to a pressed HE, a composite HE is not porous and the hot-spots are mainly located at the grain - binder interface leading to a different behavior during shock-to-detonation transition. An investigation of how shock-to-detonation transition occurs inside composite HE containing RDX and NTO is proposed in this lecture. Two composite HE have been studied. The first one is HMX - HTPB 82:18. The second one is HMX - NTO - HTPB 12:72:16. These HE have been submitted to plane sustained shock waves at different pressure levels using a laboratory powder gun. Pressure signals are measured using manganin gauges inserted at several distances inside HE. The corresponding run-distances to detonation are determined using wedge test experiments where the plate impact is performed using a powder gun. Both HE exhibit a single detonation buildup curve in the distance - time diagram of shock-to-detonation transition. This feature seems a common shock-to-detonation behavior for composite HE without porosity. This behavior is also confirmed for a RDX - HTPB 85:15 based composite HE. Such a behavior is exploited to determine the heterogeneous reaction rate versus the shock pressure using a method based on the Cauchy-Riemann problem inversion. The reaction rate laws obtained allow to compute both run-distance to detonation and pressure signals.

  5. Thermodynamic Cycle and CFD Analyses for Hydrogen Fueled Air-breathing Pulse Detonation Engines

    Science.gov (United States)

    Povinelli, Louis A.; Yungster, Shaye

    2002-01-01

    This paper presents the results of a thermodynamic cycle analysis of a pulse detonation engine (PDE) using a hydrogen-air mixture at static conditions. The cycle performance results, namely the specific thrust, fuel consumption and impulse are compared to a single cycle CFD analysis for a detonation tube which considers finite rate chemistry. The differences in the impulse values were indicative of the additional performance potential attainable in a PDE.

  6. Utilizing Near-IR Tunable Laser Absorption Spectroscopy to Study Detonation and Combustion Systems

    Science.gov (United States)

    2014-03-27

    A Hencken burner, Rotating Detonation Engine ( RDE ), and a detonation tube were studied using a Time-Devision Multiplexed Tunable Diode Laser...for the three systems. Velocity was calculated for the RDE system using the Doppler shift of the spectral lines. To perform the calculations necessary...however, the CH4 flame did not match as well. The exhaust of the RDE was studied at various equivalence ratios using a hydrogen-air mixture (H2-air

  7. Development and Testing of a Rotating Detonation Engine Run on Hydrogen and Air

    Science.gov (United States)

    2012-03-22

    Jay Rutledge (Member) Date v AFIT/GAE/ENY/12-M36 Abstract Rotating detonation engines ( RDEs ) have the potential for greater...efficiencies over conventional engines by utilizing pressure gain combustion. A new modular RDE (6 in diameter) was developed and successfully run on...hydrogen and standard air. The RDE allows for variation of injection scheme and detonation channel widths. Tests provided the operational space of the

  8. Build Up and Operation of an Axial Turbine Driven by a Rotary Detonation Engine

    Science.gov (United States)

    2012-03-01

    RDEs ) offer advantages over pulsed detonation engines (PDEs) due to a steadier exhaust and fewer total system losses. All previous research on...the integration and testing of an axial turbine driven by a rotary detonation engine ( RDE ) to determine turbine operability. In pursuit of this...objective, convergent nozzle sections were placed on the RDE to simulate the back-pressurization that would occur when placing the turbine behind the RDE

  9. Structure of Biocompatible Coatings Produced from Hydroxyapatite Nanoparticles by Detonation Spraying

    OpenAIRE

    Nosenko, Valentyna; Strutynska, Nataliia; Vorona, Igor; Zatovsky, Igor; Dzhagan, Volodymyr; Lemishko, Sergiy; Epple, Matthias; Prymak, Oleg; Baran, Nikolai; Ishchenko, Stanislav; Slobodyanik, Nikolai; Prylutskyy, Yuriy; Klyui, Nickolai; Temchenko, Volodymyr

    2015-01-01

    Detonation-produced hydroxyapatite coatings were studied by scanning electron microscopy (SEM), X-ray powder diffraction (XRD), Raman spectroscopy, and electron paramagnetic resonance (EPR) spectroscopy. The source material for detonation spraying was a B-type carbonated hydroxyapatite powder. The coatings consisted of tetracalcium phosphate and apatite. The ratio depended slightly on the degree of crystallinity of the initial powder and processing parameters of the coating preparation. The t...

  10. The corrosion resistance of zinc coatings in the presence of boron-doped detonation nanodiamonds (DND)

    Science.gov (United States)

    Burkat, G. K.; Alexandrova, G. S.; Dolmatov, V. Yu; Osmanova, E. D.; Myllymäki, V.; Vehanen, A.

    2017-02-01

    The effect of detonation nanodiamonds, doped with boron (boron-DND) in detonation synthesis on the process of zinc electrochemical deposition from zincate electrolyte is investigated. It is shown that the scattering power (coating uniformity) increases 2-4 times (depending on the concentration of DND-boron electrolyte conductivity does not change, the corrosion resistance of Zn- DND -boron coating increases 2.6 times in 3% NaCl solution (corrosion currents) and 3 times in the climatic chamber.

  11. Development of a Detonation Profile Test for Studying Aging Effects in LX-17

    International Nuclear Information System (INIS)

    Tran, T; Lewis, P; Tarver, C; Maienschein, J; Druce, R; Lee, R; Roeske, F

    2002-01-01

    A new small-scale Detonation Profile Test (DPT) is being developed to investigate aging effects on the detonation behavior of insensitive high explosives. The experiment involves initiating a small LX-17 cylindrical charge (12.7-19.1 mm diameter x 25.4-33 mm long) and measuring the velocity and curvature of the emerging detonation wave using a streak camera. Results for 12.7 mm diameter unconfined LX-17 charges show detonation velocity in the range between 6.79 and 7.06 km/s for parts up to 33 mm long. Since LX-17 can not sustain detonation at less than 7.3 km/s, these waves were definitely failing. Experiments with confined 12.7 mm diameter and unconfined 19.1 mm diameter samples showed wave velocities in the range of 7.4-7.6 km/s, values approaching steady state conditions at infinite diameter. Experiments with unconfined 19.1 mm diameter specimens are expected to provide reproducible and useful range of detonation parameters suitable for studying aging effects

  12. Development of a Detonation Profile Test for Studying Aging Effects in LX-17

    Energy Technology Data Exchange (ETDEWEB)

    Tran, T; Lewis, P; Tarver, C; Maienschein, J; Druce, R; Lee, R; Roeske, F

    2002-03-25

    A new small-scale Detonation Profile Test (DPT) is being developed to investigate aging effects on the detonation behavior of insensitive high explosives. The experiment involves initiating a small LX-17 cylindrical charge (12.7-19.1 mm diameter x 25.4-33 mm long) and measuring the velocity and curvature of the emerging detonation wave using a streak camera. Results for 12.7 mm diameter unconfined LX-17 charges show detonation velocity in the range between 6.79 and 7.06 km/s for parts up to 33 mm long. Since LX-17 can not sustain detonation at less than 7.3 km/s, these waves were definitely failing. Experiments with confined 12.7 mm diameter and unconfined 19.1 mm diameter samples showed wave velocities in the range of 7.4-7.6 km/s, values approaching steady state conditions at infinite diameter. Experiments with unconfined 19.1 mm diameter specimens are expected to provide reproducible and useful range of detonation parameters suitable for studying aging effects.

  13. Coupling Detonation Shock Dynamics in a Consistent Manner to Equations of State

    Science.gov (United States)

    Belfield, William

    2017-06-01

    In hydrocode simulations, detonating high explosives (HE) are often modelled using programmed burn. Each HE cell is assigned a ``burn time'' at which it should begin to behave as HE products in the subsequent simulation. Traditionally, these burn times were calculated using a Huygens construction to propagate the detonation wave at a constant speed corresponding to the planar Chapman-Jouguet (CJ) velocity. The Detonation Shock Dynamics (DSD) model improves upon this approach by treating the local detonation velocity as a function of wave curvature, reflecting that the detonation speed is not constant in reality. However, without alterations being made, this variable detonation velocity is inconsistent with the CJ velocity associated with the HE products equation of state (EOS). Previous work has shown that the inconsistency can be resolved by modifying the HE product EOS, but this treatment is empirical in nature and has only been applied to the JWL EOS. This work investigates different methods to resolve the inconsistency that are applicable both to JWL and to tabular HE product EOS, and their impact on hydrocode simulations.

  14. Comparative performance analysis of combined-cycle pulse detonation turbofan engines (PDTEs

    Directory of Open Access Journals (Sweden)

    Sudip Bhattrai

    2013-09-01

    Full Text Available Combined-cycle pulse detonation engines are promising contenders for hypersonic propulsion systems. In the present study, design and propulsive performance analysis of combined-cycle pulse detonation turbofan engines (PDTEs is presented. Analysis is done with respect to Mach number at two consecutive modes of operation: (1 Combined-cycle PDTE using a pulse detonation afterburner mode (PDA-mode and (2 combined-cycle PDTE in pulse detonation ramjet engine mode (PDRE-mode. The performance of combined-cycle PDTEs is compared with baseline afterburning turbofan and ramjet engines. The comparison of afterburning modes is done for Mach numbers from 0 to 3 at 15.24 km altitude conditions, while that of pulse detonation ramjet engine (PDRE is done for Mach 1.5 to Mach 6 at 18.3 km altitude conditions. The analysis shows that the propulsive performance of a turbine engine can be greatly improved by replacing the conventional afterburner with a pulse detonation afterburner (PDA. The PDRE also outperforms its ramjet counterpart at all flight conditions considered herein. The gains obtained are outstanding for both the combined-cycle PDTE modes compared to baseline turbofan and ramjet engines.

  15. Shock wave science and technology reference library. Vol. 4. Heterogeneous detonation

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Fan (ed.) [Defence Research and Development Canada, Suffield, AB (Canada)

    2009-07-01

    This book, as a volume of the Shock Wave Science and Technology Reference Library, is primarily concerned with detonation waves or compression shock waves in reactive heterogeneous media, including mixtures of solid, liquid and gas phases. The topics involve a variety of energy release and control processes in such media - a contemporary research field that has found wide applications in propulsion and power, hazard prevention as well as military engineering. The six extensive chapters contained in this volume are: - Spray Detonation (SB Murray and PA Thibault) - Detonation of Gas-Particle Flow (F Zhang) - Slurry Detonation (DL Frost and F Zhang) - Detonation of Metalized Composite Explosives (MF Gogulya and MA Brazhnikov) - Shock-Induced Solid-Solid Reactions and Detonations (YA Gordopolov, SS Batsanov, and VS Trofimov) - Shock Ignition of Particles (SM Frolov and AV Fedorov). Each chapter is self-contained and can be read independently of the others, though, they are thematically interrelated. They offer a timely reference, for graduate students as well as professional scientists and engineers, by laying out the foundations and discussing the latest developments including yet unresolved challenging problems. (orig.)

  16. Characterization of initiation and detonation by Lagrange gage techniques. Final report

    International Nuclear Information System (INIS)

    Cowperthwaite, M.

    1983-08-01

    The work on reactive flow Lagrange analysis (RFLA) was concerned with Lagrange particle velocity histories that exhibit double maxima similar to those recorded in RX26 and PBX9404. Conditions for particle velocity histories to exhibit extrema were formulated in terms of envelopes formed by Lagrange pressure histories. Lagrange analysis of the flow produced by the expansion of a detonation wave at a free surface was proposed to extend the determination of the release adiabat of detonation products from the Chapman-Jouguet (CJ) state to zero pressure. Solutions were constructed for steady-state nonideal detonation waves propagating in polytropic explosive with two reacting components. Overdriven detonation was treated both as a reactive discontinuity and as a Zeldovich-von Neumann-Doering (ZND) wave. The Rankine-Hugoniot (RH) jump conditions were used to calculate the first and second derivatives on the detonation velocity versus particle velocity Hugoniot at the CJ point. Methods of differential geometry were used to determine the conditions that allow the flow equations and RH boundary conditions to admit similarity solutions for overdriven detonation waves

  17. Effect of actuating voltage and discharge gap on plasma assisted detonation initiation process

    Science.gov (United States)

    Siyin, ZHOU; Xueke, CHE; Wansheng, NIE; Di, WANG

    2018-06-01

    The influence of actuating voltage and discharge gap on plasma assisted detonation initiation by alternating current dielectric barrier discharge was studied in detail. A loose coupling method was used to simulate the detonation initiation process of a hydrogen–oxygen mixture in a detonation tube under different actuating voltage amplitudes and discharge gap sizes. Both the discharge products and the detonation forming process assisted by the plasma were analyzed. It was found that the patterns of the temporal and spatial distributions of discharge products in one cycle keep unchanged as changing the two discharge operating parameters. However, the adoption of a higher actuating voltage leads to a higher active species concentration within the discharge zone, and atom H is the most sensitive to the variations of the actuating voltage amplitude among the given species. Adopting a larger discharge gap results in a lower concentration of the active species, and all species have the same sensitivity to the variations of the gap. With respect to the reaction flow of the detonation tube, the corresponding deflagration to detonation transition (DDT) time and distance become slightly longer when a higher actuating voltage is chosen. The acceleration effect of plasma is more prominent with a smaller discharge gap, and the benefit builds gradually throughout the DDT process. Generally, these two control parameters have little effect on the amplitude of the flow field parameters, and they do not alter the combustion degree within the reaction zone.

  18. Effect of the oxygen balance on ignition and detonation properties of liquid explosive mixtures

    International Nuclear Information System (INIS)

    Genetier, M; Osmont, A; Baudin, G

    2014-01-01

    The objective is to compare the ignition and detonation properties of various liquid high explosives having negative up to positive oxygen balance (OB): nitromethane (OB < 0), saccharose and hydrogen peroxide based mixture (quasi nil OB), hydrogen peroxide with more than 90% purity (OB > 0). The decomposition kinetic rates and the equations of state (EOS) for the liquid mixtures and detonation products (DP) are the input data for a detonation model. EOS are theoretically determined using the Woolfolk et al. universal liquid polar shock law and thermochemical computations for DP. The decomposition kinetic rate laws are determined to reproduce the shock to detonation transition for the mixtures submitted to planar plate impacts. Such a model is not sufficient to compute open field explosions. The aerial overpressure is well reproduced in the first few microseconds, however, after it becomes worse at large expansion of the fireball and the impulse is underestimated. The problem of the DP EOS alone is that it takes only the detonation into account, the secondary combustion DP – air is not considered. To solve this problem a secondary combustion model has been developed to take the OB effect into account. The detonation model has been validated on planar plate impact experiments. The secondary combustion parameters were deduced from thermochemical computations. The whole model has been used to predict the effects of the oxygen balance on open air blast effects of spherical charges.

  19. SPONTANEOUS INITIATION OF DETONATIONS IN WHITE DWARF ENVIRONMENTS: DETERMINATION OF CRITICAL SIZES

    International Nuclear Information System (INIS)

    Seitenzahl, Ivo R.; Meakin, Casey A.; Townsley, Dean M.; Truran, James W.; Lamb, Don Q.

    2009-01-01

    Some explosion models for Type Ia supernovae (SNe Ia), such as the gravitationally confined detonation (GCD) or the double detonation sub-Chandrasekhar (DDSC) models, rely on the spontaneous initiation of a detonation in the degenerate 12 C/ 16 O material of a white dwarf (WD). The length scales pertinent to the initiation of the detonation are notoriously unresolved in multidimensional stellar simulations, prompting the use of results of one-dimensional simulations at higher resolution, such as those performed for this work, as guidelines for deciding whether or not conditions reached in the higher dimensional full star simulations successfully would lead to the onset of a detonation. Spontaneous initiation relies on the existence of a suitable gradient in self-ignition (induction) times of the fuel, which we set up with a spatially localized nonuniformity of temperature-a hot spot. We determine the critical (smallest) sizes of such hot spots that still marginally result in a detonation in WD matter by integrating the reactive Euler equations with the hydrodynamics code FLASH. We quantify the dependences of the critical sizes of such hot spots on composition, background temperature, peak temperature, geometry, and functional form of the temperature disturbance, many of which were hitherto largely unexplored in the literature. We discuss the implications of our results in the context of modeling of SNe Ia.

  20. Benign neoplasms of the trachea : case reports

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hak Hee; Mun, Kyung Mi; Kim, Bum Soo; Choi, Kyu Ho; Shinn, Kyung Sub [Kangnam St. Mary' s Hospital Catholic Univ. Medical College, Seoul (Korea, Republic of)

    1997-03-01

    Benign tumors of the trachea are rare, accounting for approximately 10% of all primary tracheal neoplasms. They are frequently misdiagnosed and managed as bronchial asthma or chronic bronchitis. We report a lipoma and a leiomyoma of the trachea with emphasis on the clinical, radiographic and CT findings, and review the literature.

  1. PET in Benign Bone Marrow Disorders

    NARCIS (Netherlands)

    van der Bruggen, Wouter; Glaudemans, Andor W. J. M.; Vellenga, Edo; Slart, Riemer H. J. A.

    This review aims to describe the current status of benign bone marrow (BM) imaging using PET. BM imaging is important as the BM is not only involved in poiesis of different vital cell lines and. can be affected by primary BM disorders, but it is also frequently affected by several extramedullary

  2. Repositioning chairs in benign paroxysmal positional vertigo

    DEFF Research Database (Denmark)

    West, Niels; Hansen, Søren; Møller, Martin Nue

    2016-01-01

    The objective was to evaluate the clinical value of repositioning chairs in management of refractory benign paroxysmal positional vertigo (BPPV) and to study how different BPPV subtypes respond to treatment. We performed a retrospective chart review of 150 consecutive cases with refractory vertigo...

  3. Ultrasonographic findings of benign soft tissue tumors

    International Nuclear Information System (INIS)

    Kim, Ki Sung; Oh, Dong Heon; Jung, Tae Gun; Kim, Yong Kil; Kwon, Jung Hyeok

    1994-01-01

    To clarify the characteristic sonographic features of benign soft tissue tumors and to evaluate the usefulness of sonographic imaging. We retrospectively reviewed ultrasonographic images of 70 cases in 68 patients with histologically proved benign soft tissue tumors. The tumors include 33 lipomas, 11 hemangiomas, 11 lymphangiomas, 7 neurilemmomas, 4 epidermoid cysts, 2 fibromas, 1 mesenchymoma, and 1 myxoma. The sonographic appearances of the lesions were mainly solid in 53 cases(33 lipomas, 8 hemangiomas, 2 lymphangiomas, 7 neurilemmomas, 2 fibromas and 1 mesenchymoma), mainly cystic in 14 cases(1 hemangioma, 8 lymphangiomas, 4 epidermoid cysts, and 1 myxomal), and mixed in 3 cases(2 hemangiomas and 1 lymphangioma). Although an accurate histologic prediction could not be made in most cases, certain patterns appeared to be characteristic of specific tumor types. 26 cases(78%) of lipoma were seen as lentiform, iso- or hyperechoic, solid mass. Hemangioma had variable appearance and characteristic calcifications were seen in 3 cases. Unicameral or multiseptated cystic mass with variable thickness of echogenic septa and solid portion was the characteristic finding of lymhangioma. Neurilemmoma showed lobulated, oval to round , relatively hypoechoic mass or with without internal cystic portion. Sonographic evaluation of benign soft tissue tumors is useful in demonstrating the location, size, extent, and internal characteristic of the mass. A relatively confident diagnosis can made when the characteristic features of the benign soft tissue tumor are present on sonographic imaging

  4. Ultrasonographic findings of benign soft tissue tumors

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ki Sung; Oh, Dong Heon; Jung, Tae Gun; Kim, Yong Kil; Kwon, Jung Hyeok [Dongkang Genernal Hospital, Ulsan (Korea, Republic of)

    1994-05-15

    To clarify the characteristic sonographic features of benign soft tissue tumors and to evaluate the usefulness of sonographic imaging. We retrospectively reviewed ultrasonographic images of 70 cases in 68 patients with histologically proved benign soft tissue tumors. The tumors include 33 lipomas, 11 hemangiomas, 11 lymphangiomas, 7 neurilemmomas, 4 epidermoid cysts, 2 fibromas, 1 mesenchymoma, and 1 myxoma. The sonographic appearances of the lesions were mainly solid in 53 cases(33 lipomas, 8 hemangiomas, 2 lymphangiomas, 7 neurilemmomas, 2 fibromas and 1 mesenchymoma), mainly cystic in 14 cases(1 hemangioma, 8 lymphangiomas, 4 epidermoid cysts, and 1 myxomal), and mixed in 3 cases(2 hemangiomas and 1 lymphangioma). Although an accurate histologic prediction could not be made in most cases, certain patterns appeared to be characteristic of specific tumor types. 26 cases(78%) of lipoma were seen as lentiform, iso- or hyperechoic, solid mass. Hemangioma had variable appearance and characteristic calcifications were seen in 3 cases. Unicameral or multiseptated cystic mass with variable thickness of echogenic septa and solid portion was the characteristic finding of lymhangioma. Neurilemmoma showed lobulated, oval to round , relatively hypoechoic mass or with without internal cystic portion. Sonographic evaluation of benign soft tissue tumors is useful in demonstrating the location, size, extent, and internal characteristic of the mass. A relatively confident diagnosis can made when the characteristic features of the benign soft tissue tumor are present on sonographic imaging.

  5. Case Report: Benign Multicystic Peritoneal Mesothelioma

    Directory of Open Access Journals (Sweden)

    Nurettin Boran

    2011-08-01

    In conclusion BPMP is a rare benign cystic tumor which can be easily misdiagnosed as an ovarian cancer preoperatively. Intraoperative findings and appearence of the mass may mimic malignancy. For that reason frozen section examination will prevent overtreatment.

  6. Imaging features of benign adrenal cysts

    International Nuclear Information System (INIS)

    Sanal, Hatice Tuba; Kocaoglu, Murat; Yildirim, Duzgun; Bulakbasi, Nail; Guvenc, Inanc; Tayfun, Cem; Ucoz, Taner

    2006-01-01

    Benign adrenal gland cysts (BACs) are rare lesions with a variable histological spectrum and may mimic not only each other but also malignant ones. We aimed to review imaging features of BACs which can be helpful in distinguishing each entity and determining the subsequent appropriate management

  7. Construction of the effluent shaft at the Flamanville EPR plant. An example where electronic detonators are used

    International Nuclear Information System (INIS)

    Couvrat, Jean-Francois

    2012-01-01

    This paper gives some details on the mining procedure using electronic detonators for the mining of the effluent shaft on a highly sensitive site, the EPR reactor of Flamanville in France. The special constraints and issues associated with the use of electronic detonators are reviewed (close explosive charges, humidity and marine atmosphere, connection and current leaks, sensitization phenomena). The main advantage of electronic detonators is limiting the vibration levels

  8. Design and Testing of an H2/O2 Predetonator for a Simulated Rotating Detonation Engine Channel

    Science.gov (United States)

    2013-03-01

    Abstract A study is presented on the relationship between a pre-detonator and a detonation channel of an RDE . Testing was conducted on a straight...narrow channel made of clear polycarbonate windows connected to an H2/O2 pre-detonator to simulate the RDE initiation scheme and allow for flow...25 2.5 RDE Initiation Schemes . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 vi Page 2.5.1 Blasting Wire

  9. Containment analysis for the simultaneous detonation of two nuclear explosives

    International Nuclear Information System (INIS)

    Terhune, R.W.; Glenn, H.D.; Burton, D.E.; Rambo, J.T.

    1977-01-01

    The explosive phenomenology associated with the simultaneous detonation of two 2.2-kt nuclear explosives is examined. A comprehensive spatial-time pictorial of the resultant shock-wave phenomenology is given. The explosives were buried at depths of 200 m and 280 m, corresponding to a separation of approximately 4 final cavity radii. Constitutive relations for the surrounding medium were derived from the geophysical logs and core samples taken from an actual emplacement configuration at the Nevada Test Site. Past calculational studies indicate that successful containment may depend upon the development of a strong tangential-stress field (or ''containment cage'') surrounding the cavity at late times. A series of conditions that must be met to insure formation of this cage are presented. Calculational results, based on one- and two-dimensional finite-difference codes of continuum mechanics, describe how each condition has been fulfilled and illustrate the dynamic sequence of events important to the formation of the containment cage. They also indicate, at least for the geological site chosen, that two nuclear explosives do not combine to threaten containment

  10. Laser-supported detonation waves and pulsed laser propulsion

    International Nuclear Information System (INIS)

    Kare, J.

    1990-01-01

    A laser thermal rocket uses the energy of a large remote laser, possibly ground-based, to heat an inert propellant and generate thrust. Use of a pulsed laser allows the design of extremely simple thrusters with very high performance compared to chemical rockets. The temperatures, pressures, and fluxes involved in such thrusters (10 4 K, 10 2 atmospheres, 10 7 w/cm 2 ) typically result in the creation of laser-supported detonation (LSD) waves. The thrust cycle thus involves a complex set of transient shock phenomena, including laser-surface interactions in the ignition of the LSD wave, laser-plasma interactions in the LSD wave itself, and high-temperature nonequilibrium chemistry behind the LSD wave. The SDIO Laser Propulsion Program is investigating these phenomena as part of an overall effort to develop the technology for a low-cost Earth-to-orbit laser launch system. We will summarize the Program's approach to developing a high performance thruster, the double-pulse planar thruster, and present an overview of some results obtained to date, along with a discussion of the many research question still outstanding in this area

  11. Analysis of supercritical vapor explosions using thermal detonation wave theory

    Energy Technology Data Exchange (ETDEWEB)

    Shamoun, B.I.; Corradini, M.L. [Univ. of Wisconsin, Madison, WI (United States)

    1995-09-01

    The interaction of certain materials such as Al{sub 2}O{sub 3} with water results in vapor explosions with very high (supercritical) pressures and propagation velocities. A quasi-steady state analysis of supercritical detonation in one-dimensional multiphase flow was applied to analyze experimental data of the KROTOS (26-30) set of experiments conducted at the Joint Research Center at Ispra, Italy. In this work we have applied a new method of solution which allows for partial fragmentation of the fuel in the shock adiabatic thermodynamic model. This method uses known experiment values of the shock pressure and propagation velocity to estimate the initial mixing conditions of the experiment. The fuel and coolant were both considered compressible in this analysis. In KROTOS 26, 28, 29, and 30 the measured values of the shock pressure by the experiment were found to be higher than 25, 50, 100, and 100 Mpa respectively. Using the above data for the wave velocity and our best estimate for the values of the pressure, the predicted minimum values of the fragmented mass of the fuel were found to be 0.026. 0.04, 0.057, and 0.068 kg respectively. The predicted values of the work output corresponding to the above fragmented masses of the fuel were found to be 40, 84, 126, and 150 kJ respectively, with predicted initial void fractions of 112%, 12.5%, 8%, and 6% respectively.

  12. Detonation nanodiamonds are promising nontoxic delivery system for urothelial cells.

    Science.gov (United States)

    Zupančič, Daša; Kreft, Mateja Erdani; Grdadolnik, Maja; Mitev, Dimitar; Iglič, Aleš; Veranič, Peter

    2018-01-01

    Detonation nanodiamonds (DNDs) are carbon-based nanomaterials that are among the most promising nanoparticles available for biomedical applications so far. This is due to their biocompatibility, which could be contributed to their inert core and conformable surface nature. However, DNDs cytotoxicity for urothelial cells and the routes of their internalization remains an open question in the aspect of nanodiamond surface. We therefore analyzed four types of DNDs for cytotoxicity and internalization with normal urothelial cells and two types of cancer urothelial cell lines in vitro. Viability of any of the cell types we used was not compromised with any of four DNDs we evaluated after 24-, 48- and 72-h incubation in three different concentrations of DNDs. Transmission electron microscopy revealed that all four types of DNDs were endocytosed into all three types of urothelial cells tested here. We observed DNDs in endosomes, as well as in multivesicular bodies and multilamellar bodies. These results propose using of DNDs as a delivery system for urological applications in human nanomedicine.

  13. An integral model of plume rise from high explosive detonations

    International Nuclear Information System (INIS)

    Boughton, B.A.; De Laurentis, J.M.

    1987-01-01

    A numerical model has been developed which provides a complete description of the time evolution of both the physical and thermodynamic properties of the cloud formed when a high explosive is detonated. This simulation employs the integral technique. The model equations are derived by integrating the three-dimensional conservation equations of mass, momentum and energy over the plume cross section. Assumptions are made regarding (a) plume symmetry; (b) the shape of profiles of velocity, temperature, etc. across the plume; and (c) the methodology for simulating entrainment and the effects of the crossflow induced pressure drag force on the plume. With these assumptions, the integral equations can be reduced to a set of ordinary differential equations on the plume centerline variables. Only the macroscopic plume characteristics, e.g., plume radius, centerline height, temperature and density, are predicted; details of the plume intrastructure are ignored. The model explicitly takes into account existing meteorology and has been expanded to consider the alterations in plume behavior which occur when aqueous foam is used as a dispersal mitigating material. The simulation was tested by comparison with field measurements of cloud top height and diameter. Predictions were within 25% of field observations over a wide range of explosive yield and atmospheric stability

  14. Recent papers from DX-1, detonation science and technology

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-10-01

    Over the past year members of DX-1 have participated in several conferences where presentations were made and papers prepared for proceedings. There have also been several papers published in or submitted to refereed journals for publication. Rather that attach all these papers to the DX-1 Quarterly Report, we decided to put them in a Los Alamos report that could be distributed to those who get the quarterly, as well as others that have an interest in the work being done in DX-1 both inside and outside the Laboratory. This compilation does not represent all the work reported during the year because some people have chosen not to include their work here. In particular, there were a number of papers relating to deflagration-to-detonation modeling that were not included. However, this group of papers does present a good picture of much of the unclassified work being done in DX-1. Several of the papers include coauthors from other groups or divisions at the Laboratory, providing an indication of the collaborations in which people in DX-1 are involved. Discussed topics of submitted papers include: shock compression of condensed matter, pyrotechnics, shock waves, molecular spectroscopy, sound speed measurements in PBX-9501, chemical dimerization, and micromechanics of spall and damage in tantalum.

  15. Measurement of the pressure pulse from a detonating explosive

    International Nuclear Information System (INIS)

    Bourne, N K; Milne, A M; Biers, R A

    2005-01-01

    A series of experiments has been carried out to determine the pressure pulse exiting from a polymethylmethacrylate (PMMA) plate, of varying thickness, subject to the shock pulse exerted by a detonating charge of fixed mass. This calibration will define a new donor explosive and inert gap material for use in one of the qualification tests for energetic materials, the large scale gap test. The peak pressure was recorded on the central axis of the attenuator using calibrated piezoresistive manganin gauges as a function of the quantity of PMMA applied to the output of the donor charge. The stress history within the PMMA was measured as a function of run distance and the peak pressure plotted against thickness as a calibration. The shock front was known to have curvature and a measurement of this was attempted. The behaviour of the transmitted shock at small gap thicknesses was shown to be anomalous since the front was partially in a reactive and partially within an inert medium

  16. Numerical study of multiscale compaction-initiated detonation

    Science.gov (United States)

    Gambino, J. R.; Schwendeman, D. W.; Kapila, A. K.

    2018-02-01

    A multiscale model of heterogeneous condensed-phase explosives is examined computationally to determine the course of transient events following the application of a piston-driven stimulus. The model is a modified version of that introduced by Gonthier (Combust Sci Technol 175(9):1679-1709, 2003. https://doi.org/10.1080/00102200302373) in which the explosive is treated as a porous, compacting medium at the macro-scale and a collection of closely packed spherical grains capable of undergoing reaction and diffusive heat transfer at the meso-scale. A separate continuum description is ascribed to each scale, and the two scales are coupled together in an energetically consistent manner. Following piston-induced compaction, localized energy deposition at the sites of intergranular contact creates hot spots where reaction begins preferentially. Reaction progress at the macro-scale is determined by the spatial average of that at the grain scale. A parametric study shows that combustion at the macro-scale produces an unsteady detonation with a cyclical character, in which the lead shock loses strength and is overtaken by a stronger secondary shock generated in the partially reacted material behind it. The secondary shock in turn becomes the new lead shock and the process repeats itself.

  17. Instrumentation techniques for monitoring shock and detonation waves

    Science.gov (United States)

    Dick, R. D.; Parrish, R. L.

    1985-09-01

    CORRTEX (Continuous Reflectometry for Radius Versus Time Experiments), SLIFER (Shorted Location Indication by Frequency of Electrical Resonance), and pin probes were used to monitor several conditions of blasting such as the detonation velocity of the explosive, the functioning of the stemming column confining the explosive, and rock mass motion. CORRTEX is a passive device that employs time-domain reflectometry to interrogate the two-way transit time of a coaxial cable. SLIFER is an active device that monitors the changing frequency resulting from a change in length of a coaxial cable forming an element of an oscillator circuit. Pin probes in this application consist of RG-174 coaxial cables, each with an open circuit, placed at several known locations within the material. Each cable is connected to a pulse-forming network and a voltage source. When the cables are shorted by the advancing wave, time-distance data are produced from which a velocity can be computed. Each technique, installation of the gauge, examples of the signals, and interpretation of the records are described.

  18. Optical limiting in suspension of detonation nanodiamonds in engine oil

    Science.gov (United States)

    Mikheev, Konstantin G.; Krivenkov, Roman Yu.; Mogileva, Tatyana N.; Puzyr, Alexey P.; Bondar, Vladimir S.; Bulatov, Denis L.; Mikheev, Gennady M.

    2017-07-01

    The optical limiting (OL) of detonation nanodiamond (DND) suspensions in engine oil was studied at a temperature range of 20°C to 100°C. Oil suspensions were prepared on the basis of the DNDs with an average nanoparticle cluster size in hydrosols (Daver) of 50 and 110 nm. Raman spectroscopy was used to characterize the samples. The OL investigation was carried out by the z-scan technique. The fundamental (1064 nm) and second (532 nm) harmonic radiations of YAG:Nd3+ laser with passive Q-switching as an excitation source were used. The OL thresholds for both suspensions at 532 and 1064 nm were determined. It is shown that a decrease in the average nanoparticle cluster size as well as an increase of the wavelength of the incident radiation leads to the OL threshold increase. It is established that the OL performance is not influenced by increasing the temperature from 20°C to 100°C. The results obtained show the possibility of using the DNDs suspensions in engine oil as an optical limiter in a wide temperature range.

  19. Initiation of detonation by impact on granular explosives; Contribution a l'etude de la generation de la detonation provoquee par impact sur un explosif

    Energy Technology Data Exchange (ETDEWEB)

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

    1964-05-15

    A good number of experiments have shown up the particular behaviour of granular explosives when they are detonated by barrier transmitted shocks. Similar results can be obtained when the shock is induced by impact. In this case the pressure signal shape applied at the explosive is better known and both its intensity and duration can be varied. By using a mathematical model in which the law of chemical kinetics is a linear function of pressure, and different temperatures are used for solids and gases, it is possible to describe most of the behaviour of detonation initiation in solid granular explosives. (author) [French] De nombreuses etudes experimentales ont montre le comportement particulier des explosifs granulaires lors de la detonation provoquee par choc transmis a travers une barriere. Les memes resultats peuvent etre obtenus lorsque la detonation est engendree par impact. Dans ce cas, la forme du signal de pression induit dans l'explosif est mieux connue, et il est possible d'en faire varier l'intensite et la duree d'application. Un modele mathematique utilisant une loi de cinetique chimique fonction lineaire de la pression et ou les temperatures des etats solide et gazeux pendant la reaction sont differenciees, permet de retrouver la plupart des caracteres specifiques de la generation dans un explosif solide granulaire. (auteur)

  20. Characterizing the energy output generated by a standard electric detonator using shadowgraph imaging

    Science.gov (United States)

    Petr, V.; Lozano, E.

    2017-09-01

    This paper overviews a complete method for the characterization of the explosive energy output from a standard detonator. Measurements of the output of explosives are commonly based upon the detonation parameters of the chemical energy content of the explosive. These quantities provide a correct understanding of the energy stored in an explosive, but they do not provide a direct measure of the different modes in which the energy is released. This optically based technique combines high-speed and ultra-high-speed imaging to characterize the casing fragmentation and the detonator-driven shock load. The procedure presented here could be used as an alternative to current indirect methods—such as the Trauzl lead block test—because of its simplicity, high data accuracy, and minimum demand for test repetition. This technique was applied to experimentally measure air shock expansion versus time and calculating the blast wave energy from the detonation of the high explosive charge inside the detonator. Direct measurements of the shock front geometry provide insight into the physics of the initiation buildup. Because of their geometry, standard detonators show an initial ellipsoidal shock expansion that degenerates into a final spherical wave. This non-uniform shape creates variable blast parameters along the primary blast wave. Additionally, optical measurements are validated using piezoelectric pressure transducers. The energy fraction spent in the acceleration of the metal shell is experimentally measured and correlated with the Gurney model, as well as to several empirical formulations for blasts from fragmenting munitions. The fragment area distribution is also studied using digital particle imaging analysis and correlated with the Mott distribution. Understanding the fragmentation distribution plays a critical role when performing hazard evaluation from these types of devices. In general, this technique allows for characterization of the detonator within 6-8% error

  1. 1 Massive upper gastrointestinal bleeding and diffuse benign gastric ...

    African Journals Online (AJOL)

    Abstract: Benign gastric inflammatory hyperplasic polyps are benign lesions that rarely occur in young age. We report a case of diffuse benign gastric inflammatory hyperplastic polyps in a 19 year old male patient who presented with cough, nausea, and haematemesis. In the presented case symptoms such as nausea and.

  2. Benign Multicystic Mesothelioma in the Left Round Ligament: Case Report

    International Nuclear Information System (INIS)

    Bae, So Young; Yi, Boem Ha; Lee, Hae Kyung; Park, Seong Jin; Cho, Gyu Seok; Kwak, Jeong Ja

    2010-01-01

    Benign multicystic mesothelioma is a rare mesothelial lesion that forms multicystic masses in the upper abdomen, pelvis, and retroperitoneum. Most cases have a benign course. We present the ultrasound and MR findings of benign multicystic mesothelioma in the left round ligament, which caused a left inguinal hernia in a 46-year-old woman

  3. Benign Multicystic Mesothelioma in the Left Round Ligament: Case Report

    Energy Technology Data Exchange (ETDEWEB)

    Bae, So Young; Yi, Boem Ha; Lee, Hae Kyung; Park, Seong Jin; Cho, Gyu Seok; Kwak, Jeong Ja [Soonchunhyang University Bucheon Hospital, Bucheon (Korea, Republic of)

    2010-02-15

    Benign multicystic mesothelioma is a rare mesothelial lesion that forms multicystic masses in the upper abdomen, pelvis, and retroperitoneum. Most cases have a benign course. We present the ultrasound and MR findings of benign multicystic mesothelioma in the left round ligament, which caused a left inguinal hernia in a 46-year-old woman.

  4. Endoscopic Management of Benign Esophageal Strictures.

    Science.gov (United States)

    Ravich, William J

    2017-08-24

    This paper presents the author's approach to esophageal dilation. It offers a tailored approach to the application of dilation to specific types of esophageal stenotic lesions. In patients with inflammatory stricture, recent studies confirm the importance of treating the underlying inflammatory condition in order to decrease the rate of recurrence. The paper reviews some of the novel techniques that have been suggested for the treatment of refractory benign esophageal strictures, including incisional therapy, stenting, or the injection steroids or antifibrotic agents. The endoscopist who treats esophageal strictures must be familiar with the tools of the dilation and how they are best applied to specific types of stenotic lesions. If inflammation is present, effective management requires treatment of the inflammatory process in addition to mechanical dilation of the stenotic lesion. Controlled trials of novel approaches to treatment of refractory benign esophageal strictures are limited and will be necessary to determine efficacy.

  5. Benign nerve sheath tumor of stomach

    International Nuclear Information System (INIS)

    Chaudry, N.U.; Zafar, S.; Haque, I.U.

    2007-01-01

    Gastrointestinal mesenchymal tumors are a group of tumors, which originate from the mesenchymal stem cells of the gastrointestinal tract. Gastric schwannoma is a very rare gastrointestinal mesenchymal tumor, which represents only 0.2% of all gastric tumors and 4% of all benign gastric neoplasms. We report a 55 years old lady who suffered from pain epigastrium, vomiting, occasionally with blood, loss of appetite and weight loss. Endoscopic examination showed a round submucosal tumor with a central ulceration along the greater curvature of the stomach. The pathological examination revealed a picture of spindle cell tumor. Immunohistochemical stain was strongly positive for S-100 protein stain, and non-reactive for CD34, CD117, consistent with benign nerve sheath tumor of stomach i.e. gastric schwannoma. (author)

  6. Italian survey on benign paroxysmal positional vertigo

    OpenAIRE

    Messina, A.; Casani, A.P.; Manfrin, M.; Guidetti, G.

    2017-01-01

    SUMMARY Benign paroxysmal positional vertigo (BPPV) is the most common type of peripheral vertigo. BPPV often relapses after the first episode, with a recurrence rate between 15% and 50%. To date both the aetiopathogenetic processes that lead to otoconia detachment and the factors that make BPPV a relapsing disease are still unclear, but recent epidemiological studies have shown a possible association with cardiovascular risk factors. The aim of the present study (Sesto Senso Survey) was to e...

  7. Large Penile Mass With Unusual Benign Histopathology

    Directory of Open Access Journals (Sweden)

    Nate Johnson

    2015-09-01

    Full Text Available Pseudoepitheliomatous hyperplasia is an extremely rare condition presenting as a lesion on the glans penis in older men. Physical exam without biopsy cannot differentiate malignant from nonmalignant growth. We report a case of large penile mass in an elderly male with a history of lichen sclerosis, highly suspicious for malignancy. Subsequent surgical removal and biopsy demonstrated pseudoepitheliomatous hyperplasia, an unusual benign histopathologic diagnosis with unclear prognosis. We review the literature and discuss options for treatment and surveillance.

  8. Percutaneous treatment of benign bile duct strictures

    Energy Technology Data Exchange (ETDEWEB)

    Koecher, Martin [Department of Radiology, University Hospital, I.P.Pavlova 6, 775 20 Olomouc (Czech Republic)]. E-mail: martin.kocher@seznam.cz; Cerna, Marie [Department of Radiology, University Hospital, I.P.Pavlova 6, 775 20 Olomouc (Czech Republic); Havlik, Roman [Department of Surgery, University Hospital, I.P.Pavlova 6, 775 20 Olomouc (Czech Republic); Kral, Vladimir [Department of Surgery, University Hospital, I.P.Pavlova 6, 775 20 Olomouc (Czech Republic); Gryga, Adolf [Department of Surgery, University Hospital, I.P.Pavlova 6, 775 20 Olomouc (Czech Republic); Duda, Miloslav [Department of Surgery, University Hospital, I.P.Pavlova 6, 775 20 Olomouc (Czech Republic)

    2007-05-15

    Purpose: To evaluate long-term results of treatment of benign bile duct strictures. Materials and methods: From February 1994 to November 2005, 21 patients (9 men, 12 women) with median age of 50.6 years (range 27-77 years) were indicated to percutaneous treatment of benign bile duct stricture. Stricture of hepatic ducts junction resulting from thermic injury during laparoscopic cholecystectomy was indication for treatment in one patient, stricture of hepaticojejunostomy was indication for treatment in all other patients. Clinical symptoms (obstructive jaundice, anicteric cholestasis, cholangitis or biliary cirrhosis) have appeared from 3 months to 12 years after surgery. Results: Initial internal/external biliary drainage was successful in 20 patients out of 21. These 20 patients after successful initial drainage were treated by balloon dilatation and long-term internal/external drainage. Sixteen patients were symptoms free during the follow-up. The relapse of clinical symptoms has appeared in four patients 9, 12, 14 and 24 months after treatment. One year primary clinical success rate of treatment for benign bile duct stricture was 94%. Additional two patients are symptoms free after redilatation (15 and 45 months). One patient is still in treatment, one patient died during secondary treatment period without interrelation with biliary intervention. The secondary clinical success rate is 100%. Conclusion: Benign bile duct strictures of hepatic ducts junction or biliary-enteric anastomosis are difficult to treat surgically and endoscopically inaccessible. Percutaneous treatment by balloon dilatation and long-term internal/external drainage is feasible in the majority of these patients. It is minimally invasive, safe and effective.

  9. Benign pneumoperitoneum in progressive systemic sklerosis

    International Nuclear Information System (INIS)

    Reinbold, W.D.; Wenz, W.; Lang, B.; Freiburg Univ.

    1986-01-01

    The sclerodermatitis-specific vasculitis results in disturbed blood supply and, in rare cases, in a perforation of the intestinal wall. Prognosis is unfavourable for the intestinal pneumatosis described in sclero dermatitis. An asymptomatic benign pneumoperitoneum due to intestinal systemic sclerosis was reported for the first time in 1966. This rare complication in slerodermitis was observed in further individual cases. We want to report another case with pseudo-obstruction of the intestines and pneumoperitoneum. (orig./SHA) [de

  10. Benign Fibrous Tumour of the Parotid Gland

    Directory of Open Access Journals (Sweden)

    S.S. Sreetharan

    2005-01-01

    Full Text Available The case of a 44-year-old man with left parotid enlargement that was initially diagnosed as cementifying fibroma is presented. The lesion was found in the deep lobe of the parotid gland and was successfully removed. Postoperatively, the patient recovered well with intact facial nerve function and remained asymptomatic after 1 year. Subsequent histology revealed the mass to be a benign fibrous tumour. The diagnosis and management of this rare entity are discussed.

  11. Standard NIJ 0115.00 za testiranje otpornosti zaštitnih prsluka na ubode nožem i predmetima sa oštrim vrhom / NIJ 0115.00 standard for testing stab resistance of body armor

    Directory of Open Access Journals (Sweden)

    Đuro Jovanić

    2008-04-01

    Full Text Available Standard NIJ 0115.00 (prema Nacionalnom institutu pravde SAD, namenjen je za utvrđivanje minimuma tehničkih zahteva i metoda ispitivanja otpornosti zaštitnih prsluka, koji treba da zaštite gornji deo tela od uboda nožem i predmetima sa oštrim vrhom. Područje primene ovog standarda ograničeno je samo na pretnje ubodima, a ne na balističke pretnje, poput onih koje su obuhvaćene standardom NIJ 0101.04 za testiranje balističke otpornosti zaštitnih prsluka. / In this work made presentation of NIJ 0115.04. (National Institute of Justice standard, witch purpose is to establish minimum performance requirements and methods of testing for the stab resistance of body armor intended to protect the torso against slash and stab threats. The scope of the standard is limited to stab resistance only; the standard does not address ballistic threats, as those are covered by NIJ Standard 0101.04. Ballistic Resistance of Personal Body Armor.

  12. Numerical modelling of continuous spin detonation in rich methane-oxygen mixture

    International Nuclear Information System (INIS)

    Trotsyuk, A V

    2016-01-01

    A numerical simulation of a two-dimensional structure of the detonation wave (DW) in a rich (equivalence ratio φ=1.5) methane-air mixture at normal initial condition has been conducted. The computations have been performed in a wide range of channel heights. From the analysis of the flow structure and the number of primary transverse waves in the channel, the dominant size of the detonation cell for studied mixture has been determined to be 45÷50 cm. Based on the fundamental studies of multi-front (cellular) structure of the classical propagating DW in methane mixtures, numerical simulation of continuous spin detonation (CSD) of rich (φ=1.2) methane-oxygen mixture has been carried out in the cylindrical detonation chamber (DC) of the rocket-type engine. We studied the global flow structure in DC, and the detailed structure of the front of the rotating DW. Integral characteristics of the detonation process - the distribution of average values of static and total pressure along the length of the DC, and the value of specific impulse have been obtained. The geometric limit of stable existence of CSD has been determined. (paper)

  13. Double-detonation model of type Ia supernovae with a variable helium layer ignition mass

    International Nuclear Information System (INIS)

    Zhou Wei-Hong; Zhao Gang; Wang Bo

    2014-01-01

    Although Type Ia supernovae (SNe Ia) play an important role in the study of cosmology, their progenitors are still poorly understood. Thermonuclear explosions from the helium double-detonation sub-Chandrasekhar mass model have been considered as an alternative method for producing SNe Ia. By adopting the assumption that a double detonation occurs when a He layer with a critical ignition mass accumulates on the surface of a carbon—oxygen white dwarf (CO WD), we perform detailed binary evolution calculations for the He double-detonation model, in which a He layer from a He star accumulates on a CO WD. According to these calculations, we obtain the initial parameter spaces for SNe Ia in the orbital period and secondary mass plane for various initial WD masses. We implement these results into a detailed binary population synthesis approach to calculate SN Ia birthrates and delay times. From this model, the SN Ia birthrate in our Galaxy is ∼0.4 − 1.6 × 10 −3 yr −1 . This indicates that the double-detonation model only produces part of the SNe Ia. The delay times from this model are ∼ 70 – 710 Myr, which contribute to the young population of SNe Ia in the observations. We found that the CO WD + sdB star system CD–30 11223 could produce an SN Ia via the double-detonation model in its future evolution. (research papers)

  14. Experimental study of detonation of large-scale powder-droplet-vapor mixtures

    Science.gov (United States)

    Bai, C.-H.; Wang, Y.; Xue, K.; Wang, L.-F.

    2018-05-01

    Large-scale experiments were carried out to investigate the detonation performance of a 1600-m3 ternary cloud consisting of aluminum powder, fuel droplets, and vapor, which were dispersed by a central explosive in a cylindrically stratified configuration. High-frame-rate video cameras and pressure gauges were used to analyze the large-scale explosive dispersal of the mixture and the ensuing blast wave generated by the detonation of the cloud. Special attention was focused on the effect of the descending motion of the charge on the detonation performance of the dispersed ternary cloud. The charge was parachuted by an ensemble of apparatus from the designated height in order to achieve the required terminal velocity when the central explosive was detonated. A descending charge with a terminal velocity of 32 m/s produced a cloud with discernably increased concentration compared with that dispersed from a stationary charge, the detonation of which hence generates a significantly enhanced blast wave beyond the scaled distance of 6 m/kg^{1/3}. The results also show the influence of the descending motion of the charge on the jetting phenomenon and the distorted shock front.

  15. Saw palmetto for benign prostatic hyperplasia.

    Science.gov (United States)

    Bent, Stephen; Kane, Christopher; Shinohara, Katsuto; Neuhaus, John; Hudes, Esther S; Goldberg, Harley; Avins, Andrew L

    2006-02-09

    Saw palmetto is used by over 2 million men in the United States for the treatment of benign prostatic hyperplasia and is commonly recommended as an alternative to drugs approved by the Food and Drug Administration. In this double-blind trial, we randomly assigned 225 men over the age of 49 years who had moderate-to-severe symptoms of benign prostatic hyperplasia to one year of treatment with saw palmetto extract (160 mg twice a day) or placebo. The primary outcome measures were changes in the scores on the American Urological Association Symptom Index (AUASI) and the maximal urinary flow rate. Secondary outcome measures included changes in prostate size, residual urinary volume after voiding, quality of life, laboratory values, and the rate of reported adverse effects. There was no significant difference between the saw palmetto and placebo groups in the change in AUASI scores (mean difference, 0.04 point; 95 percent confidence interval, -0.93 to 1.01), maximal urinary flow rate (mean difference, 0.43 ml per minute; 95 percent confidence interval, -0.52 to 1.38), prostate size, residual volume after voiding, quality of life, or serum prostate-specific antigen levels during the one-year study. The incidence of side effects was similar in the two groups. In this study, saw palmetto did not improve symptoms or objective measures of benign prostatic hyperplasia. (ClinicalTrials.gov number, NCT00037154.). Copyright 2006 Massachusetts Medical Society.

  16. Environmentally benign silicon solar cell manufacturing

    Energy Technology Data Exchange (ETDEWEB)

    Tsuo, Y.S. [National Renewable Energy Lab., Golden, CO (United States); Gee, J.M. [Sandia National Labs., Albuquerque, NM (United States); Menna, P. [National Agency for New Technologies Energy and Environment, Portici (Italy); Strebkov, D.S.; Pinov, A.; Zadde, V. [Intersolarcenter, Moscow (Russian Federation)

    1998-09-01

    The manufacturing of silicon devices--from polysilicon production, crystal growth, ingot slicing, wafer cleaning, device processing, to encapsulation--requires many steps that are energy intensive and use large amounts of water and toxic chemicals. In the past two years, the silicon integrated-circuit (IC) industry has initiated several programs to promote environmentally benign manufacturing, i.e., manufacturing practices that recover, recycle, and reuse materials resources with a minimal consumption of energy. Crystalline-silicon solar photovoltaic (PV) modules, which accounted for 87% of the worldwide module shipments in 1997, are large-area devices with many manufacturing steps similar to those used in the IC industry. Obviously, there are significant opportunities for the PV industry to implement more environmentally benign manufacturing approaches. Such approaches often have the potential for significant cost reduction by reducing energy use and/or the purchase volume of new chemicals and by cutting the amount of used chemicals that must be discarded. This paper will review recent accomplishments of the IC industry initiatives and discuss new processes for environmentally benign silicon solar-cell manufacturing.

  17. Assessment of Blasting Performance Using Electronic Vis-à-Vis Shock Tube Detonators in Strong Garnet Biotite Sillimanite Gneiss Formations

    Science.gov (United States)

    Sharma, Suresh Kumar; Rai, Piyush

    2016-04-01

    This paper presents a comparative investigation of the shock tube and electronic detonating systems practised in bench blasting. The blast trials were conducted on overburden rocks of Garnet Biotite Sillimanite Gneiss formations in one of the largest metalliferous mine of India. The study revealed that the choice of detonating system was crucial in deciding the fragment size and its distribution within the blasted muck-piles. The fragment size and its distribution affected the digging rate of excavators. Also, the shape of the blasted muck-pile was found to be related to the degree of fragmentation. From the present work, it may be inferred that in electronic detonation system, timely release of explosive energy resulted in better overall blasting performance. Hence, the precision in delay time must be considered in designing blast rounds in such overburden rock formations. State-of-art image analysis, GPS based muck-pile profile plotting techniques were rigorously used in the investigation. The study revealed that a mean fragment size (K50) value for shock tube detonated blasts (0.55-0.59 m) was higher than that of electronically detonated blasts (0.43-0.45 m). The digging rate of designated shovels (34 m3) with electronically detonated blasts was consistently more than 5000 t/h, which was almost 13 % higher in comparison to shock tube detonated blasts. Furthermore, favourable muck-pile shapes were witnessed in electronically detonated blasts from the observations made on the dozer performance.

  18. Understanding the shock and detonation response of high explosives at the continuum and meso scales

    Science.gov (United States)

    Handley, C. A.; Lambourn, B. D.; Whitworth, N. J.; James, H. R.; Belfield, W. J.

    2018-03-01

    The shock and detonation response of high explosives has been an active research topic for more than a century. In recent years, high quality data from experiments using embedded gauges and other diagnostic techniques have inspired the development of a range of new high-fidelity computer models for explosives. The experiments and models have led to new insights, both at the continuum scale applicable to most shock and detonation experiments, and at the mesoscale relevant to hotspots and burning within explosive microstructures. This article reviews the continuum and mesoscale models, and their application to explosive phenomena, gaining insights to aid future model development and improved understanding of the physics of shock initiation and detonation propagation. In particular, it is argued that "desensitization" and the effect of porosity on high explosives can both be explained by the combined effect of thermodynamics and hydrodynamics, rather than the traditional hotspot-based explanations linked to pressure-dependent reaction rates.

  19. Research on verification and validation strategy of detonation fluid dynamics code of LAD2D

    Science.gov (United States)

    Wang, R. L.; Liang, X.; Liu, X. Z.

    2017-07-01

    The verification and validation (V&V) is an important approach in the software quality assurance of code in complex engineering application. Reasonable and efficient V&V strategy can achieve twice the result with half the effort. This article introduces the software-Lagrangian adaptive hydrodynamics code in 2D space (LAD2D), which is self-developed software in detonation CFD with plastic-elastic structure. The V&V strategy of this detonation CFD code is presented based on the foundation of V&V methodology for scientific software. The basic framework of the module verification and the function validation is proposed, composing the detonation fluid dynamics model V&V strategy of LAD2D.

  20. Critique of the Board-Hall model for thermal detonations in UO2--Na systems

    International Nuclear Information System (INIS)

    Williams, D.C.

    1976-01-01

    The Board--Hall model for detonating thermal explosions is reviewed and some criticisms are offered in terms of its application to UO 2 -Na systems. The basic concept of a detonation-like thermal explosion is probably valid provided certain fundamental conditions can be met; however, Board and Hall's arguments as to just how these conditions can be met in UO 2 -Na mixtures appear to contain serious flaws. Even as given, the model itself predicts that a very large triggering event is needed to initiate the process. More importantly, the model for shock-induced fragmentation greatly overestimates the tendency for such fragmentation to occur. The shock-dispersive effects of mixtures are ignored. Altogether, the model's deficiencies imply that, as given, it is not applicable to LMFBR accident analysis; nonetheless, one cannot completely rule out the possibility of meeting the fundamental conditions for detonation by other mechanisms

  1. The effect of initial pressure on detonation propagation across a mixture

    Directory of Open Access Journals (Sweden)

    Yao-Chung Hsu

    2016-07-01

    Full Text Available This study determines the effect of the initial pressure on the propagation of a Chapman–Jouguet detonation wave from a stoichiometric C3H8/O2 mixture (donor to a stoichiometric C3H8/air mixture (acceptor. Depending on the initial pressure ratio in the donor and the acceptor, the result can be a smooth transmission, a re-initiated detonation wave, or a transmitted shock wave. When the donor is divided into a driver donor and a driven donor, the degree of overdrive in a driven donor varies with the donor pressure ratio. There must be a greater degree of overdrive in the driven donor for re-initiation of a detonation wave in the acceptor, particularly if the initial pressure in the driven donor is lower than the Chapman–Jouguet pressure in the acceptor. The bi-dimensional effect is also another major factor.

  2. Deflagration to Detonation Transition (DDT) Simulations of HMX Powder Using the HERMES Model

    Science.gov (United States)

    White, Bradley; Reaugh, John; Tringe, Joseph

    2017-06-01

    We performed computer simulations of DDT experiments with Class I HMX powder using the HERMES model (High Explosive Response to MEchanical Stimulus) in ALE3D. Parameters for the model were fitted to the limited available mechanical property data of the low-density powder, and to the Shock to Detonation Transition (SDT) test results. The DDT tests were carried out in steel-capped polycarbonate tubes. This arrangement permits direct observation of the event using both flash X-ray radiography and high speed camera imaging, and provides a stringent test of the model. We found the calculated detonation transition to be qualitatively similar to experiment. Through simulation we also explored the effects of confinement strength, the HMX particle size distribution and porosity on the computed detonation transition location. This work was performed under the auspices of the US DOE by LLNL under Contract DE-AC52-07NA27344.

  3. Transmission of an overdriven plane detonation in lean hydrogen-air mixtures

    International Nuclear Information System (INIS)

    Desbordes, D.; Lannoy, A.

    1988-01-01

    This paper deals with hydrogen-air explosions hazards in nuclear power plants, if PWR Loss Of Coolant Accident occurs. The main objective concerns the determination of the size of the critical diameter of transmission of a detonation propagating in a near stoechiometric H 2 -Air mixture. In such a situation the diffracting detonation is an overdriven wave. Laboratory scale simulations are described which emphasize the importance of a negative step of concentration of combustible in a mixture (stoechio to lean) on plane detonation characteristics of the lean mixture, especially the drastric reduction (i) of the size of its inrinsic tridimensional structure and (ii) correlatively that of the critical diameter of transmission of the mixture

  4. Investigations on deflagration to detonation transition in porous energetic materials. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Stewart, D.S. [Univ. of Illinois, Urbana, IL (United States)

    1999-07-01

    The research carried out by this contract was part of a larger effort funded by LANL in the areas of deflagration to detonation in porous energetic materials (DDT) and detonation shock dynamics in high explosives (DSD). In the first three years of the contract the major focus was on DDT. However, some researchers were carried out on DSD theory and numerical implementation. In the last two years the principal focus of the contract was on DSD theory and numerical implementation. However, during the second period some work was also carried out on DDT. The paper discusses DDT modeling and DSD modeling. Abstracts are included on the following topics: modeling deflagration to detonation; DSD theory; DSD wave front tracking; and DSD program burn implementation.

  5. Numerical Analysis of a Rotating Detonation Engine in the Relative Reference Frame

    Science.gov (United States)

    Paxson, Daniel E.

    2014-01-01

    A two-dimensional, computational fluid dynamic (CFD) simulation of a semi-idealized rotating detonation engine (RDE) is described. The simulation operates in the detonation frame of reference and utilizes a relatively coarse grid such that only the essential primary flow field structure is captured. This construction yields rapidly converging, steady solutions. Results from the simulation are compared to those from a more complex and refined code, and found to be in reasonable agreement. The performance impacts of several RDE design parameters are then examined. Finally, for a particular RDE configuration, it is found that direct performance comparison can be made with a straight-tube pulse detonation engine (PDE). Results show that they are essentially equivalent.

  6. Calculations of hydrogen detonations in nuclear containments by the random choice method

    International Nuclear Information System (INIS)

    Delichatsios, M.A.; Genadry, M.B.

    1983-01-01

    Computer codes were developed for the prediction of pressure histories at different points of a nuclear containment wall due to postulated internal hydrogen detonations. These pressure histories are required to assess the structural response of a nuclear containment to hydrogen detonations. The compressible flow equations including detonation, which was treated as a sharp fluid discontinuity, were solved by the random choice method which reproduces maximum pressures and discontinuities sharply. The computer codes were validated by calculating pressure profiles and maximum wall pressures for plane and spherical geometries and comparing the results with exact analytic solutions. The two-dimensional axisymmetric program was used to calculate wall pressure histories in an actual nuclear containment. The numerical results for wall pressures are presented in a dimensionless form, which allows their use for different combinations of hydrogen concentration, and initial conditions. (orig.)

  7. Optimization long hole blast fragmentation techniques and detonating circuit underground uranium mine stope

    International Nuclear Information System (INIS)

    Li Qin; Yang Lizhi; Song Lixia; Qin De'en; Xue Yongshe; Wang Zhipeng

    2012-01-01

    Aim at high rate of large blast fragmentation, a big difficulty in long hole drilling and blasting underground uranium mine stope, it is pointed out at the same time of taking integrated technical management measures, the key is to optimize the drilling and blasting parameters and insure safety the act of one that primes, adopt 'minimum burden' blasting technique, renew the stope fragmentation process, and use new process of hole bottom indirect initiation fragmentation; optimize the detonating circuit and use safe, reliable and economically rational duplex non-electric detonating circuit. The production practice shows that under the guarantee of strictly controlled construction quality, the application of optimized blast fragmentation technique has enhanced the reliability of safety detonation and preferably solved the problem of high rate of large blast fragments. (authors)

  8. Analysis of sheltering and evacuation strategies for a national capital region nuclear detonation scenario.

    Energy Technology Data Exchange (ETDEWEB)

    Yoshimura, Ann S.; Brandt, Larry D.

    2011-12-01

    Development of an effective strategy for shelter and evacuation is among the most important planning tasks in preparation for response to a low yield, nuclear detonation in an urban area. Extensive studies have been performed and guidance published that highlight the key principles for saving lives following such an event. However, region-specific data are important in the planning process as well. This study examines some of the unique regional factors that impact planning for a 10 kT detonation in the National Capital Region. The work utilizes a single scenario to examine regional impacts as well as the shelter-evacuate decision alternatives at one exemplary point. For most Washington, DC neighborhoods, the excellent assessed shelter quality available make shelter-in-place or selective transit to a nearby shelter a compelling post-detonation strategy.

  9. Structural integrity of a reinforced concrete structure and a pipe outlet under hydrogen detonation conditions

    International Nuclear Information System (INIS)

    Saarenheimo, A.; Silde, A.; Calonius, K.

    2002-05-01

    Structural integrity of a reinforced concrete wall and a pipe penetration under detonation conditions in a selected reactor building room of Olkiluoto BWR were studied. Hydrogen leakage from the pressurised containment to the sur rounding reactor building is possible during a severe accident. Leaked hydrogen tends to accumulate in the reactor building rooms where the leak is located leading to a stable stratification and locally very high hydrogen concentration. If ignited, a possibility to flame acceleration and detonation cannot be ruled out. The structure may survive the peak detonation transient because the eigenperiod of the structure is considerably longer than the duration of the peak detonation. However, the relatively slowly decreasing static type pressure after a peak detonation damages the wall more severely. Elastic deformations in reinforcement are recoverable and cracks in these areas will close after the pressure decrease. But there will be remarkable compression crushing and the static type slowly decreasing over pressure clearly exceeds the loading capacity of the wall. Structural integrity of a pipe outlet was considered also under detonation conditions. The effect of drag forces was taken into account. Damping and strain rate dependence of yield strength were not taken into consideration. The boundary condition at the end of the pipe line model was varied in order to find out the effect of the stiffness of the pipeline outside the calculation model. The calculation model where the lower pipe end is free to move axially, is conservative from the pipe penetration integrity point of view. Even in this conservative study, the highest peak value for the maximum plastic deformation is 3.5%. This is well below the success criteria found in literature. (au)

  10. Detonation cell size measurements and predictions in hydrogen-air-steam mixtures at elevated temperatures

    International Nuclear Information System (INIS)

    Ciccarelli, G.; Ginsberg, T.; Boccio, J.; Economos, C.

    1994-01-01

    The present research reports on the effect of initial mixture temperature on the experimentally measured detonation cell size for hydrogen-air-steam mixtures. Experimental and theoretical research related to combustion phenomena in hydrogen-air-steam mixtures has been ongoing for many years. However, detonation cell size data currently exists or hydrogen-air-steam mixtures up to a temperature of only 400K. Sever accident scenarios have been identified for light water reactors (LWRs) where hydrogen-air mixture temperatures in excess of 400K could be generated within containment. The experiments in this report focus on extending the cell size data base for initial mixture temperatures in excess of 400K. The experiments were carried out in a 10-cm inner-diameter, 6.1-m long heated detonation tube with a maximum operating temperature of 700K and spatial temperature uniformity of ±14K. Detonation cell size measurements provide clear evidence that the effect of hydrogen-air initial gas mixture temperature, in the range 300K--650K, is to decrease cell size and, hence, to increase the sensitivity of the mixture to undergo detonations. The effect of steam content, at any given temperature, is to increase the cell size and, thereby, to decrease the sensitivity of stoichiometric hydrogen-air mixtures. The hydrogen-air detonability limits for the 10-cm inside-diameter test vessel, based upon the onset of single-head spin, decreased from 15 percent by hydrogen at 300K down to about 9 percent hydrogen at 650K. The one-dimensional ZND model does a very good job at predicting the overall trends in the cell size data over the range of hydrogen-air-steam mixture compositions and temperature studied in the experiments

  11. Empirical equation of state of the products of the detonation of a liquid explosive based on mixtures of tetranitromethane and nitrobenzene of various compositions

    International Nuclear Information System (INIS)

    Adigamova, T.A.; Davydov, N.B.

    2012-01-01

    The equation of state of the products of the detonation of liquid explosives has been derived by theoretical analysis and calculations. The dependence of the detonation rate on the oxygen balance has been obtained using the existing data on the physicomechanical and detonation properties of liquid explosive mixtures. Calculation dependences of the density on the weight content of nitrobenzene have been obtained [ru

  12. Controlling the position of a stabilized detonation wave in a supersonic gas mixture flow in a plane channel

    Science.gov (United States)

    Levin, V. A.; Zhuravskaya, T. A.

    2017-03-01

    Stabilization of a detonation wave in a stoichiometric hydrogen-air mixture flowing at a supersonic velocity into a plane symmetric channel with constriction has been studied in the framework of a detailed kinetic mechanism of the chemical interaction. Conditions ensuring the formation of a thrust-producing f low with a stabilized detonation wave in the channel are determined. The inf luence of the inf low Mach number, dustiness of the combustible gas mixture supplied to the channel, and output cross-section size on the position of a stabilized detonation wave in the f low has been analyzed with a view to increasing the efficiency of detonation combustion of the gas mixture. It is established that thrust-producing flow with a stabilized detonation wave can be formed in the channel without any energy consumption.

  13. Direct morphological comparison of vacuum plasma sprayed and detonation gun sprayed hydroxyapatite coatings for orthopaedic applications.

    Science.gov (United States)

    Gledhill, H C; Turner, I G; Doyle, C

    1999-02-01

    Hydroxyapatite coatings on titanium substrates were produced using two thermal spray techniques vacuum plasma spraying and detonation gun spraying. X-ray diffraction was used to compare crystallinity and residual stresses in the coatings. Porosity was measured using optical microscopy in conjunction with an image analysis system. Scanning electron microscopy and surface roughness measurements were used to characterise the surface morphologies of the coatings. The vacuum plasma sprayed coatings were found to have a lower residual stress, a higher crystallinity and a higher level of porosity than the detonation gun coatings. It is concluded that consideration needs to be given to the significance of such variations within the clinical context.

  14. Detonability of turbulent white dwarf plasma: Hydrodynamical models at low densities

    Science.gov (United States)

    Fenn, Daniel

    The origins of Type Ia supernovae (SNe Ia) remain an unsolved problem of contemporary astrophysics. Decades of research indicate that these supernovae arise from thermonuclear runaway in the degenerate material of white dwarf stars; however, the mechanism of these explosions is unknown. Also, it is unclear what are the progenitors of these objects. These missing elements are vital components of the initial conditions of supernova explosions, and are essential to understanding these events. A requirement of any successful SN Ia model is that a sufficient portion of the white dwarf plasma must be brought under conditions conducive to explosive burning. Our aim is to identify the conditions required to trigger detonations in turbulent, carbon-rich degenerate plasma at low densities. We study this problem by modeling the hydrodynamic evolution of a turbulent region filled with a carbon/oxygen mixture at a density, temperature, and Mach number characteristic of conditions found in the 0.8+1.2 solar mass (CO0812) model discussed by Fenn et al. (2016). We probe the ignition conditions for different degrees of compressibility in turbulent driving. We assess the probability of successful detonations based on characteristics of the identified ignition kernels, using Eulerian and Lagrangian statistics of turbulent flow. We found that material with very short ignition times is abundant in the case that turbulence is driven compressively. This material forms contiguous structures that persist over many ignition time scales, and that we identify as prospective detonation kernels. Detailed analysis of the kernels revealed that their central regions are densely filled with material characterized by short ignition times and contain the minimum mass required for self-sustained detonations to form. It is conceivable that ignition kernels will be formed for lower compressibility in the turbulent driving. However, we found no detonation kernels in models driven 87.5 percent

  15. An approach to incorporate the detonation shock dynamics into the calculation of explosive acceleration of metals

    International Nuclear Information System (INIS)

    Li Qingzhong; Sun Chengwei; Zhao Feng; Gao Wen; Wen Shanggang; Liu Wenhan

    1999-11-01

    The generalized geometrical optics model for the detonation shock dynamics (DSD) has been incorporated into the two dimensional hydro-code WSU to form a combination code ADW for numerical simulation of explosive acceleration of metals. An analytical treatment of the coupling conditions at the nodes just behind the detonation front is proposed. The experiments on two kinds of explosive-flyer assemblies with different length/diameter ratio were carried out to verify the ADW calculations, where the tested explosive was HMX or TATB based. It is found that the combination of DSD and hydro-code can improve the calculation precision, and has advantages in larger meshes and less CPU time

  16. Finite element analysis of Polymer reinforced CRC columns under close-in detonation

    DEFF Research Database (Denmark)

    Riisgaard, Benjamin

    2007-01-01

    Polymer reinforced Compact Reinforced Composite, PCRC, is a Fiber reinforced Densified Small Particle system, FDSP, combined with a high strength longitudinal flexural rebar arrangement laced together with polymer lacing to avoid shock initiated disintegration of the structural element under blast...... load. Experimental and numerical results of two PCRC columns subjected to close-in detonation are presented in this paper. Additionally, a LS-DYNA material model suitable for predicting the response of Polymer reinforced Compact Reinforced Concrete improved for close-in detonation and a description...

  17. Small-angle neutron scattering study of high-pressure sintered detonation nanodiamonds

    Energy Technology Data Exchange (ETDEWEB)

    Kidalov, S. V.; Shakhov, F. M., E-mail: fedor.shakhov@mail.ioffe.ru [Ioffe Physical-Technical Institute of the Russian Academy of Sciences (Russian Federation); Lebedev, V. T.; Orlova, D. N.; Grushko, Yu. S. [Russian Academy of Sciences, Konstantinov St. Petersburg Nuclear Physics Institute (Russian Federation)

    2011-12-15

    The structure of detonation diamonds sintered at a high pressure (7 GPa) and temperatures of 1200-1700 Degree-Sign C has been investigated by small-angle neutron scattering. It is shown that sintering leads to an increase in the particle size from 6 to 30 nm and established that this increase is due to the chainlike oriented attachment of particles. This study supplements the oriented-attachment model, which was suggested based on the X-ray diffraction spectra of detonation nanodiamonds (DNDs) sintered under the same conditions.

  18. On detonation dynamics in hydrogen-air-steam mixtures: Theory and application to Olkiluoto reactor building

    International Nuclear Information System (INIS)

    Silde, A.; Lindholm, I.

    2000-02-01

    This report consists of the literature study of detonation dynamics in hydrogen-air-steam mixtures, and the assessment of shock pressure loads in Olkiluoto 1 and 2 reactor building under detonation conditions using the computer program DETO developed during this work at VTT. The program uses a simple 1-D approach based on the strong explosion theory, and accounts for the effects of both the primary or incident shock and the first (oblique or normal) reflected shock from a wall structure. The code results are also assessed against a Balloon experiment performed at Germany, and the classical Chapman-Jouguet detonation theory. The whole work was carried out as a part of Nordic SOS-2.3 project, dealing with severe accident analysis. The initial conditions and gas distribution of the detonation calculations are based on previous severe accident analyses by MELCOR and FLUENT codes. According to DETO calculations, the maximum peak pressure in a structure of Olkiluoto reactor building room B60-80 after normal shock reflection was about 38.7 MPa if a total of 3.15 kg hydrogen was assumed to burned in a distance of 2.0 m from the wall structure. The corresponding pressure impulse was about 9.4 kPa-s. The results were sensitive to the distance used. Comparison of the results to classical C-J theory and the Balloon experiments suggested that DETO code represented a conservative estimation for the first pressure spike under the shock reflection from a wall in Olkiluoto reactor building. Complicated 3-D phenomena of shock wave reflections and focusing, nor the propagation of combustion front behind the shock wave under detonation conditions are not modeled in the DETO code. More detailed 3-D analyses with a specific detonation code are, therefore, recommended. In spite of the code simplifications, DETO was found to be a beneficial tool for simple first-order assessments of the structure pressure loads under the first reflection of detonation shock waves. The work on assessment

  19. Photographic investigation into the mechanism of combustion in irregular detonation waves

    Science.gov (United States)

    Kiyanda, C. B.; Higgins, A. J.

    2013-03-01

    Irregular detonations are supersonic combustion waves in which the inherent multi-dimensional structure is highly variable. In such waves, it is questionable whether auto-ignition induced by shock compression is the only combustion mechanism present. Through the use of high-speed schlieren and self-emitted light photography, the velocity of the different components of detonation waves in a {{ CH}}_4+2{ O}_2 mixture is analyzed. The observed burn-out of unreacted pockets is hypothesized to be due to turbulent combustion.

  20. Benign mass in tonsil- cavernous hemangioma.

    Science.gov (United States)

    Joseph, Sumitha; Prakash, M; Mohammed, Hafida K; Govar, Aberna

    2013-10-01

    Cavernous hemangioma is also called as 'ANGIOMA CAVERNOSUM' or 'CAVERNOMA' as benign lesion of blood vessels. They are similar to strawberry hemangioma but deeply situated. Although most often associated with skin it is also sometimes found in mucous membrane, brain and the viscera. The diagnosis of hemangiomas is mainly based on clinical evaluation . Isolated hemangiomas in the tonsillar tissue is a rare occurance. In this we report had a case of adult tonsillar hemangioma of left side associated with recurrent tonsillitis . He was effectively managed surgically without any complications.

  1. Differential diagnosis of benign intrahepatic tumours

    International Nuclear Information System (INIS)

    Koenig, R.; Herter, M.; Deutsches Krebsforschungszentrum, Heidelberg

    1983-01-01

    Differential diagnosis of benign intrahepatic tumours can be very difficult despite numerous non-invasive diagnostic approaches, as is evident from two case reports presented here. The problem appears particularly intricate if two or more masses or space-occupying growths are present at the same time, the diagnostic aspects being different. In the first case, echinococcus alveolaris occurred simultaneously with a cavernous haemangioma and a focal nodular hyperplasia (FNH). In the second case, FNH as a pendulating tumour was combined with a second focus in the superior part of the liver. These two examples are used as basis for discussing various diagnostic approaches, such as sonography, computed tomography and scintiscanning. (orig.) [de

  2. Differential diagnosis of benign intrahepatic tumours

    Energy Technology Data Exchange (ETDEWEB)

    Koenig, R.; Herter, M.

    1983-01-01

    Differential diagnosis of benign intrahepatic tumours can be very difficult despite numerous non-invasive diagnostic approaches, as is evident from two case reports presented here. The problem appears particularly intricate if two or more masses or space-occupying growths are present at the same time, the diagnostic aspects being different. In the first case, echinococcus alveolaris occurred simultaneously with a cavernous haemangioma and a focal nodular hyperplasia (FNH). In the second case, FNH as a pendulating tumour was combined with a second focus in the superior part of the liver. These two examples are used as basis for discussing various diagnostic approaches, such as sonography, computed tomography and scintiscanning.

  3. CT morphology of benign median nerve tumors

    International Nuclear Information System (INIS)

    Feyerabend, T.; Schmitt, R.; Lanz, U.; Warmuth-Metz, M.; Wuerzburg Univ.

    1990-01-01

    Computed tomography (CT) was performed in 3 patients with benign tumors of the median nerve, histologically confirmed as neurilemmoma, fibrolipoma and hemangioma. The neurilemmoma showed a ring-shaped contrast enhancement. The fibrolipoma presented with areas of solid soft tissue and areas of fat. The hemangioma was a solid tumor with a lacunar, vascular contrast enhancement. According to our experience and to the previous literature CT gives useful information regarding the anatomic location, size, and relationship of peripheral nerve sheath tumors to surrounding structures, and may help to differentiate between various tumor types. (orig.)

  4. Ureteritis cystica: A rare benign lesion

    Directory of Open Access Journals (Sweden)

    F. Ibrahim

    2014-09-01

    Full Text Available Ureteritis cystica is an uncommon benign pathology of the ureter. The etiology is unclear but the diagnosis has become much easier to make with the routine use of ureteroscopy for diagnosis of ureteric lesions. We present a case of a 63 year old Sudanese woman with a history of repeated attacks of right loin pain in whom magnetic resonance urography (MRU showed multiple filling defects in the right ureter. These were initially thought to be malignant urothelial lesions. Ureteroscopy revealed cystic smooth walled masses which discharged tiny turbid fluid on biopsy. An intraoperative diagnosis of ureteritis cystica was confirmed. The patient was managed conservatively.

  5. Urodynamic implications of benign prostatic hyperplasia

    DEFF Research Database (Denmark)

    Jensen, K M; Andersen, J T

    1990-01-01

    By the age of 60, about 70% of men have developed benign prostatic hyperplasia (BPH), and 85%-95% of these have symptomatic dysfunction of the lower urinary tract, 10%-20% undergoing prostatectomy. Although transurethral resection of the prostate is generally considered to be a safe and effective...... instability has no bearing on the postoperative result. Measurement of urinary flow, in contrast, is of predictive value in BPH, patients in whom the maximum urinary flow before surgery is more than 15 ml/s having significantly worse results of surgery than those with a maximum urinary flow of less than 15 ml...

  6. Impact of radiation therapy for benign diseases

    International Nuclear Information System (INIS)

    Kantor, G.; Van Houtte, P.; Beauvois, S.; Roelandts, M.

    1997-01-01

    Radiation therapy of benign diseases represent a wide panel of indications. Some indications are clearly identified as treatment of arteriovenous malformations (AVM), hyperthyroid ophthalmopathy, postoperative heterotopic bone formations or keloid scars. Some indications are under evaluation as complications induced by neo-vessels of age-related macular degeneration or coronary restenosis after angioplasty. Some indications remain controversial with poor evidence of efficiency as treatment of bursitis, tendinitis or Dupuytren's disease. Some indications are now obsolete such as warts, or contra-indicated as treatment of infant and children. (authors)

  7. The Universal Role of Tubulence in the Propagation of Strong Shocks and Detonation Waves

    Science.gov (United States)

    Lee, John H.

    2001-06-01

    The passage of a strong shock wave usually results in irreversible physical and chemical changes in the medium. If the chemical reactions are sufficiently exothermic, the shock wave can be self-propagating, i.e., sustained by the chemical energy release via the expansion work of the reaction products. Although shocks and detonations can be globally stable and propagate at constant velocities (in the direction of motion), their structure may be highly unstable and exhibit large hydrodynamic fluctuations, i.e., turbulence. Recent investigations on plastic deformation of polycrystalline material behind shock waves have revealed particle velocity dispersion at the mesoscopic level, a result of vortical rotational motion similar to that of turbulent fluid flows at high Reynolds number.1 Strong ionizing shocks in noble gases2, as well as dissociating shock waves in carbon dioxide,3 also demonstrate a turbulent density fluctuation in the non-equilibrium shock transition zone. Perhaps the most thoroughly investigated unstable structure is that of detonation waves in gaseous explosives.4 Detonation waves in liquid explosives such as nitromethane also take on similar unstable structure as gaseous detonations.5 There are also indications that detonations in solid explosives have a similar unsteady structure under certain conditions. Thus, it appears that it is more of a rule than an exception that the structure of strong shocks and detonations are unstable and exhibit turbulent-like fluctuations as improved diagnostics now permit us to look more closely at the meso- and micro-levels. Increasing attention is now devoted to the understanding of the shock waves at the micro-scale level in recent years. This is motivated by the need to formulate physical and chemical models that contain the correct physics capable of describing quantitatively the shock transition process. It should be noted that, in spite of its unstable 3-D structure, the steady 1-D conservation laws (in the

  8. Benign Angiomyolipoma with Renal Vein Invasion: A Case Report

    International Nuclear Information System (INIS)

    Kim, Mi Seon; Park, Soo Youn; Hwang, Seong Su

    2009-01-01

    Angiomyolipomas are the most common type of benign renal tumors and are characterized by a mixture of mature adipose tissue, sheet of smooth muscle, and thick-walled blood vessels of various proportions. Several cases of angiomyolipoma with partial malignant transformation invading the adjacent structure and lymph node have been reported. On the other hand, benign angiomyolipomas invading the adjacent structures has been rarely reported. We report a case of a benign angiomyolipoma with renal vein invasion

  9. Benign cementoblastoma (true cementoma in a cat

    Directory of Open Access Journals (Sweden)

    Lenin A Villamizar-Martinez

    2016-01-01

    Full Text Available Case summary A 10-year-old castrated male domestic shorthair cat was presented for assessment of a gingival mass surrounding the left maxillary third and fourth premolar teeth. The mass was surgically removed by means of a marginal rim excision, and the tissue was submitted for histological assessment. It was identified as a benign cementoblastoma (true cementoma. There was proliferation of mineralized eosinophilic material with multiple irregularly placed lacunae and reversal lines, reminiscent of cementum. The cat recovered uneventfully from the anesthesia, and there was no evidence of tumor recurrence 6 months after surgery. Relevance and novel information Cementoblastomas (true cementomas in domestic animals are rare, with just a few reports in ruminants, monogastric herbivores and rodents. Cementoblastoma is considered a benign tumor that arises from the tooth root. The slow, expansive and constant growth that characterizes these masses may be accompanied by signs of oral discomfort and dysphagia. This case report is intended to increase knowledge regarding this tumor in cats and also highlights the importance of complete excision of the neoplasm. To our knowledge, there are no previous reports in the literature of cementoblastoma in the cat.

  10. Benign renal complex cysts: MR imaging

    International Nuclear Information System (INIS)

    Levy, P.; Helenon, O.; Melki, P.; Paraf, F.; Chauveau, D.; Chretien, Y.; Moreau, J.F.

    1994-01-01

    The aim of this study was to assess the magnetic resonance imaging (MRI) characteristics of 13 benign complex renal cysts using T1 and T2-weighted images and contrast-enhanced images. The results have been compared to CT and ultrasonographic findings in all cases and correlated with histopathologic datas in 12 cases. Five groups have been defined according to the MR features. Group 1: homogeneous low signal intensity on T1-weighted images and homogeneous high signal intensity on T2-weighted images mimicking simple cyst (n = 2); group 2: homogeneous high signal intensity on both T1 and T2-weighted images mimicking hemorrhagic cyst (n = 1); group 3: characterized by high signal intensity on T1-weighted images and fluid-iron level on T2-weighted images (n = 3); group 4: characterized by fluid-iron level on both T1 and T2-weighted images (n = 3); group 5: pseudotumoral feature: heterogeneous signal intensity and/or wall contrast enhancement (n = 3). Among the 13 indeterminate lesions on ultrasonography and CT, MRI was of diagnostic value in 8 cases, whereas the 5 remaining cases remained indeterminate on MR images. Our results suggest that MRI can be useful in the diagnosis of benign complex cyst of the kidney presenting as indeterminate cystic lesion on other modalities. (authors). 40 refs., 7 figs., 2 tabs

  11. Surgery versus pharmacotherapy of benign thyroid diseases

    International Nuclear Information System (INIS)

    Younes, Nidal A.; Albousal, Abla M.

    2003-01-01

    Surgical management of thyroid diseases (BTDs) has been a topic of interest and confusion for many years. Almost 80% of thyroidectomies at an average endocrine surgical unit are carried out for BTDs.Resistance to surgical intervention in BTDs has been based on the belief that increased complication rate is inherent in its use, this is despite thepotential advatages in terms of confirming the benign nature of the lesion, controlling the disease, and relieving of local symptoms of large neck mass. Benign thyroid diseases are more likely to occur in middle-aged woman living in iodine deficient areas, or have a family history of goiter, or in patients taking iodine-containig drugs, like amoidarone, or in patients with previous history of x-ray exposure. However, the physician must be carefull in making the diagnosis of BTDsin patients of extremes of age or in presence of positive history of radiation, or in patients with family history of thyroid or colon cancer . In this atricle we will review the etiology,epidemiology , diagonastic methodologiesand the recent trends in the sugical and medical mangement of BTDs. (author)

  12. Percutaneous dilatation of biliary benign strictures

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jae Hyung; Choi, Byung Ihn; Sung, Kyu Bo; Han, Man Chung; Park, Yong Hyun; Yoon, Yong Bum [Seoul National University College of Medicine, Seoul (Korea, Republic of)

    1986-06-15

    Percutaneous biliary dilation was done in 3 patients with benign strictures. The first case was 50-year-old male who had multiple intrahepatic stones with biliary stricture. The second 46-year-old female and the third 25-year-old male suffered from recurrent cholangitis with benign stricture of anastomotic site after choledocho-jejunostomy. In the first case, a 6mm diameter Grunzing dilatation balloon catheter was introduced through the T-tube tract. In the second case, the stricture was dilated with two balloons of 5mm and 8mm in each diameter sequentially through the U-loop tract formed by surgically made jejunostomy and percutaneous transhepatic puncture. In the third case, the dilatation catheter was introduced through the percutaneous transhepatic tract. Dilatation was made with a pressure of 5 to 10 atmospheres for 1 to 3 minutes duration for 3 times. In all 3 cases, the strictures were successfully dilated and in second and third cases internal stent was left across the lesion for prevention of restenosis.

  13. Benign vascular sexual headache and exertional headache: interrelationships and long term prognosis.

    OpenAIRE

    Silbert, P L; Edis, R H; Stewart-Wynne, E G; Gubbay, S S

    1991-01-01

    There is a definite relationship between the vascular type of benign sexual headache and benign exertional headache. Forty five patients with benign vascular sexual headache were reviewed. Twenty seven (60%) experienced benign vascular sexual headache alone and eighteen (40%) had experienced both benign vascular sexual headache and benign exertional headache on at least one occasion. The mean age was 34.3 years with a male:female ratio of 5.4:1. Thirty patients with a history of benign vascul...

  14. [The cause and efficacy of benign tracheal stenosis].

    Science.gov (United States)

    Su, Zhu-quan; Wei, Xiao-qun; Zhong, Chang-hao; Chen, Xiao-bo; Luo, Wei-zhan; Guo, Wen-liang; Wang, Ying-zhi; Li, Shi-yue

    2013-09-01

    To analysis the causes of benign tracheal stenosis and evaluate the curative effect of intraluminal bronchoscopic treatment. 158 patients with benign tracheal stenosis in our hospital from September 2005 to September 2012 were collected to retrospectively analysis the causes and clinic features of tracheal stenosis. Interventional treatments through bronchoscopy were used to treat the benign tracheal stenosis and the curative effects were evaluated. 158 cases of benign tracheal stenosis were recruited to our study, 69.6% of them were young and middle-aged. The main causes of benign tracheal stenosis were as follows: secondary to postintubation or tracheotomy in 61.4% (97/158), tuberculosis in 16% (26/158), benign tumor in 5.1% (8/158) and other 27 cases. 94.3% patients improved in symptoms with alleviation immediately after bronchoscopic treatment, the average tracheal diameter increased form (4.22 ± 2.06) mm to (10.16 ± 2.99) mm (t = 21.48, P benign tracheal stenosis were increasing year by year. The most common cause of benign tracheal stenosis was postintubation and tracheotomy. Interventional treatments through bronchoscopy is effective in treating benign tracheal stenosis, but repeated interventional procedures may be required to maintain the favorable long-term effects.

  15. Benign and malignant tumors of the foot and ankle

    Energy Technology Data Exchange (ETDEWEB)

    Singer, Adam D.; Datir, Abhijit; Langley, Travis [Emory University Hospital, Department of Radiology, Section of Musculoskeletal Imaging, Atlanta, GA (United States); Tresley, Jonathan [University of Wisconsin, Department of Radiology, Madison, WI (United States); Clifford, Paul D.; Jose, Jean; Subhawong, Ty K. [University of Miami, Department of Radiology, Miami, FL (United States)

    2016-03-15

    Pain and focal masses in the foot and ankle are frequently encountered and often initiate a workup including imaging. It is important to differentiate benign lesions from aggressive benign or malignant lesions. In this review, multiple examples of osseous and soft tissue tumors of the foot and ankle will be presented. Additionally, the compartmental anatomy of the foot and ankle will be discussed in terms of its relevance for percutaneous biopsy planning and eventual surgery. Finally, a general overview of the surgical management of benign, benign aggressive and malignant tumors of the foot and ankle will be discussed. (orig.)

  16. Clustered microcalcifications without mass on mammography : benignancy vs. malignancy

    Energy Technology Data Exchange (ETDEWEB)

    Han, Yoon Hee; Do, Young Soo; Oh, Hoon Il; Kim, Ki Hwan; Chin, Soo Yil [Korean Cancer Center Hostpital, Seoul (Korea, Republic of); Cho, Byung Jae [Chung Dam Radiologic Clinics, Seoul (Korea, Republic of); Han, Heon [Chungang Gil Hospital, Seoul (Korea, Republic of); Choi, Yeun Hyeun; Han, Boo Kyung [Sam Sung Medical Center, Seoul (Korea, Republic of); Park, Jung Mi [Asan Medical Center, Seoul (Korea, Republic of)

    1996-11-01

    The purpose of this study is to evaluate the accuracy of differentiation between benign and malignant clustered microcalcifications without mass on mammogram. Fourty six mammograms of 44 patients showing clustered microcalcifications without mass were interpreted blindly by five independent observers majoring in breast imaging from different institutions. Twenty two were malignant (10 infiltrating ductal carcinomas, 12 intraductal carcinomas) and 24 were benign (all fibrocystic disease). The observers judge benignancy or malignancy of microcalcifications. The authors assess the accuracy of differential diagnosis of clustered microcalcifications. Of 24 cases proved benign microcalcifications, five radiologists correctly interpreted 20 on average as benign and of malignant 22 cases, 16 on average were correctly interpreted as malignant. The diagnostic accuracy of malignant microcalcifications was 71.8% on average(63.6%{approx}81.8%) and the diagnostic accuracy for benign microcalcifications was 83% on average(71%{approx}92%). It was 9 among total 46 cases that were misinterpreted by more than three radiologists. Among these 9 cases, malignant microcalcifications that had been misinterpreted as benign were seven, benign microcalcifications misinterpreted as malignant were two. The diagnostic accuracy of clustered malignant microcalcifications(71.8%) without mass on mammogram was lower than that of benign microcalcifications(83.3%). So, in case of suspected malignant microcalcification on mammogram, it is preferable that along with magnification view, histopathologic confirmation by core biopsy must be obtained.

  17. The use of light detectors to discriminate between detonation and deflagration of explosive charges

    CSIR Research Space (South Africa)

    Olivier, M

    2015-10-01

    Full Text Available It is well known that reacting explosives emit light of varying intensity across the spectrum. Measurement of this light emission could have many applications, i.a. the local or stand-off discrimination between full detonation and deflagration...

  18. A novel method for the measurement of the von Neumann spike in detonating high explosives

    Science.gov (United States)

    Sollier, A.; Bouyer, V.; Hébert, P.; Doucet, M.

    2016-06-01

    We present detonation wave profiles measured in T2 (97 wt. % TATB) and TX1 (52 wt. % TATB and 45 wt. % HMX) high explosives. The experiments consisted in initiating a detonation wave in a 15 mm diameter cylinder of explosive using an explosive wire detonator and an explosive booster. Free surface velocity wave profiles were measured at the explosive/air interface using a Photon Doppler Velocimetry system. We demonstrate that a comparison of these free surface wave profiles with those measured at explosive/window interfaces in similar conditions allows to bracket the von Neumann spike in a narrow range. For T2, our measurements show that the spike pressure lies between 35.9 and 40.1 GPa, whereas for TX1, it lies between 42.3 and 47.0 GPa. The numerical simulations performed in support to these measurements show that they can be used to calibrate reactive burn models and also to check the accuracy of the detonation products equation of state at low pressure.

  19. LX-17 and ufTATB Data for Corner-Turning, Failure and Detonation

    Energy Technology Data Exchange (ETDEWEB)

    Souers, P C; Lauderbach, L; Garza, R; Vitello, P; Hare, D E

    2010-02-03

    Data is presented for the size (diameter) effect for ambient and cold confined LX-17, unconfined ambient LX-17, and confined ambient ultrafine TATB. Ambient, cold and hot double cylinder corner-turning data for LX-17, PBX 9502 and ufTATB is presented. Transverse air gap crossing in ambient LX-17 is studied with time delays given for detonations that cross.

  20. Determination of γ value in equation of state of detonation products by cylinder test

    International Nuclear Information System (INIS)

    Hua Pinghuan

    2001-01-01

    A method for the determination of γ value in γ law equation of state (EOS) of detonation products (DP) by cylinder test (CT) is provided. The γ values determined by this method are not surely in agreement with that determined by free-surface velocity method (FVM), but they can be used to satisfactorily calculate DP's ability to do work

  1. Modeling reaction histories to study chemical pathways in condensed phase detonation

    International Nuclear Information System (INIS)

    Scott Stewart, D.; Hernández, Alberto; Lee, Kibaek

    2016-01-01

    The estimation of pressure and temperature histories, which are required to understand chemical pathways in condensed phase explosives during detonation, is discussed. We argue that estimates made from continuum models, calibrated by macroscopic experiments, are essential to inform modern, atomistic-based reactive chemistry simulations at detonation pressures and temperatures. We present easy to implement methods for general equation of state and arbitrarily complex chemical reaction schemes that can be used to compute reactive flow histories for the constant volume, the energy process, and the expansion process on the Rayleigh line of a steady Chapman-Jouguet detonation. A brief review of state-of-the-art of two-component reactive flow models is given that highlights the Ignition and Growth model of Lee and Tarver [Phys. Fluids 23, 2362 (1980)] and the Wide-Ranging Equation of State model of Wescott, Stewart, and Davis [J. Appl. Phys. 98, 053514 (2005)]. We discuss evidence from experiments and reactive molecular dynamic simulations that motivate models that have several components, instead of the two that have traditionally been used to describe the results of macroscopic detonation experiments. We present simplified examples of a formulation for a hypothetical explosive that uses simple (ideal) equation of state forms and detailed comparisons. Then, we estimate pathways computed from two-component models of real explosive materials that have been calibrated with macroscopic experiments.

  2. First-Principles Petascale Simulations for Predicting Deflagration to Detonation Transition in Hydrogen-Oxygen Mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Khokhlov, Alexei [Univ. of Chicago, IL (United States). Dept. of Astronomy and Astrophysics. Enrico Fermi Inst.; Austin, Joanna [Argonne National Lab. (ANL), Argonne, IL (United States). Argonne Leadership Computing Facility; Bacon, C. [Univ. of Illinois, Urbana, IL (United States). Dept. of Aerospace Engineering

    2015-03-02

    Hydrogen has emerged as an important fuel across a range of industries as a means of achieving energy independence and to reduce emissions. DDT and the resulting detonation waves in hydrogen-oxygen can have especially catastrophic consequences in a variety of industrial and energy producing settings related to hydrogen. First-principles numerical simulations of flame acceleration and DDT are required for an in-depth understanding of the phenomena and facilitating design of safe hydrogen systems. The goals of this project were (1) to develop first-principles petascale reactive flow Navier-Stokes simulation code for predicting gaseous high-speed combustion and detonation (HSCD) phenomena and (2) demonstrate feasibility of first-principles simulations of rapid flame acceleration and deflagration-to-detonation transition (DDT) in stoichiometric hydrogen-oxygen mixture (2H2 + O2). The goals of the project have been accomplished. We have developed a novel numerical simulation code, named HSCD, for performing first-principles direct numerical simulations of high-speed hydrogen combustion. We carried out a series of validating numerical simulations of inert and reactive shock reflection experiments in shock tubes. We then performed a pilot numerical simulation of flame acceleration in a long pipe. The simulation showed the transition of the rapidly accelerating flame into a detonation. The DDT simulations were performed using BG/Q Mira at the Argonne National Laboratory, currently the fourth fastest super-computer in the world.

  3. Numerical Simulation of the Deflagration-to-Detonation Transition in Inhomogeneous Mixtures

    Directory of Open Access Journals (Sweden)

    Florian Ettner

    2014-01-01

    different modes of DDT. Detonations occurring soon after ignition do not necessarily cause the highest pressure loads. In mixtures with concentration gradient, the highest loads can occur in regions of very low hydrogen content. These new findings should be considered in future safety studies.

  4. Characterization of Air Emissions from Open Burning and Open Detonation of Gun Propellants and Ammunition

    Science.gov (United States)

    Emissions from open burning (OB) and open detonation (OD) of military ordnance and static fires (SF) of rocket motors were sampled in fall, 2013 at the Dundurn Depot (Saskatchewan, Canada). Emission sampling was conducted with an aerostat-lofted instrument package termed the “Fl...

  5. Ultrafast Fiber Bragg Grating Interrogation for Sensing in Detonation and Shock Wave Experiments.

    Science.gov (United States)

    Rodriguez, George; Gilbertson, Steve M

    2017-01-27

    Chirped fiber Bragg grating (CFBG) sensors coupled to high speed interrogation systems are described as robust diagnostic approaches to monitoring shock wave and detonation front propagation tracking events for use in high energy density shock physics applications. Taking advantage of the linear distributed spatial encoding of the spectral band in single-mode CFBGs, embedded fiber systems and associated photonic interrogation methodologies are shown as an effective approach to sensing shock and detonation-driven loading processes along the CFBG length. Two approaches, one that detects spectral changes in the integrated spectrum of the CFBG and another coherent pulse interrogation approach that fully resolves its spectral response, shows that 100-MHz-1-GHz interrogation rates are possible with spatial resolution along the CFBG in the 50 µm to sub-millimeter range depending on the combination of CFBG parameters (i.e., length, chirp rate, spectrum) and interrogator design specifics. Results from several dynamic tests are used to demonstrate the performance of these high speed systems for shock and detonation propagation tracking under strong and weak shock pressure loading: (1) linear detonation front tracking in the plastic bonded explosive (PBX) PBX-9501; (2) tracking of radial decaying shock with crossover to non-destructive CFBG response; (3) shock wave tracking along an aluminum cylinder wall under weak loading accompanied by dynamic strain effects in the CFBG sensor.

  6. Explosion and detonation of ozone in mixtures with carrier gases employed in nuclear technology

    International Nuclear Information System (INIS)

    Weh, M.M.L.

    1988-09-01

    Explosive ozone is known to be formed during low temperature radiolysis of oxygen. Detailed knowledge on the explosion and the detonation of ozone is therefore required for safety considerations of nuclear installations such as proposed for the cryogenic separation of 85 krypton from the head end off gas of a reprocessing plant. The explosion properties of gaseous ozone in mixtures with oxygen, nitrogen, helium, argon, krypton, xenon and difluorodichloromethane were studied by varying the ozone concentration, the initial pressure and the shape of the vessel containing the gas. Detonation velocities were determined for gaseous mixtures of ozone with oxygen, argon, krypton or xenon as functions of the ozone concentration. In addition, the initial pressure was varied for ozone-xenon mixtures. The effect of a packing such as used in the 85 Kr-separation plant 'KRETA' in KfK on ozone-xenon detonation was investigated. In addition, the effect of low amounts of carbon monoxide, methane and nitrogen dioxide on the explosion (O 3 /Ar) and the detonation (O 3 /Xe) of an ozone-noble gas mixture was determined. (orig.) [de

  7. A Manganin Thin Film Ultra-High Pressure Sensor for Microscale Detonation Pressure Measurement

    Directory of Open Access Journals (Sweden)

    Guodong Zhang

    2018-03-01

    Full Text Available With the development of energetic materials (EMs and microelectromechanical systems (MEMS initiating explosive devices, the measurement of detonation pressure generated by EMs in the microscale has become a pressing need. This paper develops a manganin thin film ultra-high pressure sensor based on MEMS technology for measuring the output pressure from micro-detonator. A reliable coefficient is proposed for designing the sensor’s sensitive element better. The sensor employs sandwich structure: the substrate uses a 0.5 mm thick alumina ceramic, the manganin sensitive element with a size of 0.2 mm × 0.1 mm × 2 μm and copper electrodes of 2 μm thick are sputtered sequentially on the substrate, and a 25 μm thick insulating layer of polyimide is wrapped on the sensitive element. The static test shows that the piezoresistive coefficient of manganin thin film is 0.0125 GPa−1. The dynamic experiment indicates that the detonation pressure of micro-detonator is 12.66 GPa, and the response time of the sensor is 37 ns. In a word, the sensor developed in this study is suitable for measuring ultra-high pressure in microscale and has a shorter response time than that of foil-like manganin gauges. Simultaneously, this study could be beneficial to research on ultra-high-pressure sensors with smaller size.

  8. Detonation wear-resistant coatings, alloy powders based on Cr-Si

    Directory of Open Access Journals (Sweden)

    А.Г. Довгаль

    2009-03-01

    Full Text Available  Coatings from composition material Cr-Si-B on steel by detonation spraying method are obtained. Composition, structure and tribotechnical characteristics of coatings in comparison with traditional materials on the basis of Ni-Cr and alloy of tungsten and cobalt are investigated.

  9. Role of Air-Breathing Pulse Detonation Engines in High Speed Propulsion

    Science.gov (United States)

    Povinelli, Louis A.; Lee, Jin-Ho; Anderberg, Michael O.

    2001-01-01

    In this paper, the effect of flight Mach number on the relative performance of pulse detonation engines and gas turbine engines is investigated. The effect of ram and mechanical compression on combustion inlet temperature and the subsequent sensible heat release is determined. Comparison of specific thrust, fuel consumption and impulse for the two engines show the relative benefits over the Mach number range.

  10. Numerical investigation of unsteady detonation waves in combustion chamber using Shchelkin spirals

    Directory of Open Access Journals (Sweden)

    Repaka Ramesh

    2016-09-01

    Full Text Available : Pulse Detonation Engine (PDE is considered to be a propulsive system of future air vehicles. The main objective is to minimizing the Deflagration to Detonation transition run-up distance and time by placing Shchelkin spiral with varying pitch length. Here we have considered blockage-area ratio is 0.5 as optimal value from review of previous studies. In the present study the detonation initiation and propagation is modeled numerically using commercial CFD codes GAMBIT and FLUENT. The unsteady and two-dimensional compressible Reynolds Averaged Navier-Stokes equation is used to simulate the model. Fuel-air mixture of Hydrogen-air is used for better efficiency of PDE. It is very simple straight tube with Shchelkin spirals, one of the methods which is used to initiate detonation is creation of high pressure and temperature chamber region with 0.5cm from closed end of tube where shock will generate and transition into low pressure and temperature region propagates towards end of the tube. Two different zones namely high and low pressure zones are used as interface in modeling and patching has been used to fill the zones with hydrogen and oxygen with different pressure and temperatures hence shock leads to propagate inside the combustion chamber.

  11. Laser-shocked energetic materials with metal additives: evaluation of detonation performance

    Science.gov (United States)

    Gottfried, Jennifer; Bukowski, Eric

    A focused, nanosecond-pulsed laser with sufficient energy to exceed the breakdown threshold of a material generates a laser-induced plasma with high peak temperatures, pressures, and shock velocities. Depending on the laser parameters and material properties, nanograms to micrograms of material is ablated, atomized, ionized and excited in the laser-induced plasma. The subsequent shock wave expansion into the air above the sample has been monitored using high-speed schlieren imaging in a recently developed technique, laser-induced air shock from energetic materials (LASEM). The estimated detonation velocities using LASEM agree well with published experimental values. A comparison of the measured shock velocities for various energetic materials including RDX, DNTF, and LLM-172 doped with Al or B to the detonation velocities predicted by CHEETAH for inert or active metal participation demonstrates that LASEM has potential for predicting the early time participation of metal additives in detonation events. The LASEM results show that reducing the amount of hydrogen present in B formulations increases the resulting detonation velocities

  12. Turbulent flame acceleration and detonation quenching and reinitiation - modelling and validation

    International Nuclear Information System (INIS)

    Fischer, M.; Kratzel, T.; Pantow, E.

    1997-01-01

    For both, the reactor safety in an accidental release of hydrogen into containment compartments and also for the industrial safety of the production, storage and transport of combustibles like hydrogen, propane, methane and others in the Petroleum, Petrochemical and Pharmaceutical Industries, it is of great interest to know how the pressure forces of fast hydrogen combustion processes can be reduced. The numerical study of highly turbulent or detonation driven flame propagation processes is relatively recent because it depends on the availability of high performance computers and specialized numerical algorithms to solve the governing equations of reactive fluid dynamic processes. Numerical simulation can be used at a number of levels to study turbulent combustion and detonations. What is needed is both, to use modelling and numerical simulation to investigate fundamental interactions, and using modelling and numerical simulation as a tool to predict turbulent flame accelerating processes and decoupling or re-initiation of detonation waves in complex geometries of technical applications. Today, modelling and simulation show good agreement with a variety of fast combustion phenomena observed in experiments. Results of reactive computational fluid dynamics codes deliver inputs to reduce experimental parameters and provide the basis for an innovative design of arresters for deflagration and detonation processes. (author)

  13. Chemical Kinetics in the expansion flow field of a rotating detonation-wave engine

    Science.gov (United States)

    Kailasanath, Kazhikathra; Schwer, Douglas

    2014-11-01

    Rotating detonation-wave engines (RDE) are a form of continuous detonation-wave engines. They potentially provide further gains in performance than an intermittent or pulsed detonation-wave engine (PDE). The overall flow field in an idealized RDE, primarily consisting of two concentric cylinders, has been discussed in previous meetings. Because of the high pressures involved and the lack of adequate reaction mechanisms for this regime, previous simulations have typically used simplified chemistry models. However, understanding the exhaust species concentrations in propulsion devices is important for both performance considerations as well as estimating pollutant emissions. A key step towards addressing this need will be discussed in this talk. In this approach, an induction parameter model is used for simulating the detonation but a more detailed finite-chemistry model is used in the expansion flow region, where the pressures are lower and the uncertainties in the chemistry model are greatly reduced. Results show that overall radical concentrations in the exhaust flow are substantially lower than from earlier predictions with simplified models. The performance of a baseline hydrogen/air RDE increased from 4940 s to 5000 s with the expansion flow chemistry, due to recombination of radicals and more production of H2O, resulting in additional heat release.

  14. Numerical and Analytical Assessment of a Coupled Rotating Detonation Engine and Turbine Experiment

    Science.gov (United States)

    Paxson, Daniel E.; Naples, Andrew

    2017-01-01

    An analysis is presented of an experimental rig comprising a rotating detonation engine (RDE) with bypass flow coupled to a downstream turbine. The analysis used a validated computational fluid dynamics RDE simulation combined with straightforward algebraic mixing equations for the bypass flow. The objectives of the analysis were to supplement and interpret the necessarily sparse measurements from the rig, and to assess the performance of the RDE itself (which was not instrumented in this installation). The analysis is seen to agree reasonably well with available data. It shows that the RDE is operating in an unusual fashion, with subsonic flow throughout the exhaust plane. The detonation event itself is producing a total pressure rise relative to the pre-detonative pressure; however, the length of the device and the substantial flow restriction at the inlet yield an overall pressure loss. This is not surprising since the objective of the rig test was primarily aimed at investigating RDEturbine interactions, and not on performance optimization. Furthermore, the RDE was designed for fundamental detonation studies and not performance. Nevertheless, the analysis indicates that with some small alterations to the design, an RDE with an overall pressure rise is possible.

  15. 33 CFR Appendix A to Part 154 - Guidelines for Detonation Flame Arresters

    Science.gov (United States)

    2010-07-01

    ... SECURITY (CONTINUED) POLLUTION FACILITIES TRANSFERRING OIL OR HAZARDOUS MATERIAL IN BULK Pt. 154, App. A... constructed to minimize the effect of fouling under normal operating conditions. 8.11Detonation flame... diameters long with a plastic bag over the free end. (Alternate end of pipe closures are also acceptable...

  16. Antitumor Properties of Modified Detonation Nanodiamonds and Sorbed Doxorubicin on the Model of Ehrlich Ascites Carcinoma.

    Science.gov (United States)

    Medvedeva, N N; Zhukov, E L; Inzhevatkin, E V; Bezzabotnov, V E

    2016-01-01

    We studied antitumor properties of modified detonation nanodiamonds loaded with doxorubicin on in vivo model of Ehrlich ascites carcinoma. The type of tumor development and morphological characteristics of the liver, kidneys, and spleen were evaluated in experimental animals. Modified nanodiamonds injected intraperitoneally produced no antitumor effect on Ehrlich carcinoma. However, doxorubicin did not lose antitumor activity after sorption on modified nanodiamonds.

  17. Effects of modified detonation nanodiamonds on the biochemical composition of human blood.

    Science.gov (United States)

    Baron, A V; Puzyr, A P; Baron, I I; Bondar, V S

    2013-04-01

    In vitro experiments showed that protein and non-protein components of human blood serum could be absorbed on the surface of modified nanodiamonds obtained by detonation synthesis. The prospects of using nanodiamond as a new absorbent for hemodialysis, plasmapheresis, and laboratory diagnostics are discussed.

  18. On the lubrication mechanism of detonation-synthesis nanodiamond additives in lubricant composites

    Science.gov (United States)

    Shepelevskii, A. A.; Esina, A. V.; Voznyakovskii, A. P.; Fadin, Yu. A.

    2017-09-01

    The lubrication of detonation-synthesis diamond additives in lubricant composites has been discussed. The mechanism of interaction between nanodiamonds and friction surface has been shown to depend on the applied load. Two models of the lubrication of nanodiamonds and the conditions for their validity have also been proposed.

  19. Effect of graphite particle size and content on the formation mechanism of detonation polycrystalline diamond

    Science.gov (United States)

    Tong, Y.; Cao, Y.; Liu, R.; Shang, S. Y.; Huang, F. L.

    2018-03-01

    The formation mechanism of detonation polycrystalline diamond (DPD) generated from the detonation of a mixed RDX/graphite explosive is investigated. It is found experimentally that the DPD conversion rate decreases with both the content and the particle size of the graphite. Moreover, the particle sizes of the generated DPD powder are analyzed, which shows that, with the decrease in the graphite particle size, the mean number diameter of DPD decreases, but the mean volume diameter increases. In addition, with the help of scanning electron microscopy, it is observed that the in situ phase change occurs in the graphite particles, by which the small particles combine to form numerous large DPD particles. Based on both the experimental data and the classical ZND detonation model, we divide such a DPD synthesis process into two stages: In the first stage, the in situ phase change from graphite to diamond is dominant, supplemented by some coalescence growth at high pressure and temperature, which is affected mainly by the detonation performance of the mixed explosive under consideration. In the second stage, the graphitization of DPD caused by the residual heat is dominant, which is affected mainly by the unloading rate of the particle temperature.

  20. Electrical modeling of semiconductor bridge (SCB) BNCP detonators with electrochemical capacitor firing sets

    Energy Technology Data Exchange (ETDEWEB)

    Marx, K.D. [Sandia National Labs., Livermore, CA (United States); Ingersoll, D.; Bickes, R.W. Jr. [Sandia National Labs., Albuquerque, NM (United States)

    1998-11-01

    In this paper the authors describe computer models that simulate the electrical characteristics and hence, the firing characteristics and performance of a semiconductor bridge (SCB) detonator for the initiation of BNCP [tetraammine-cis-bis (5-nitro-2H-tetrazolato-N{sup 2}) cobalt(III) perchlorate]. The electrical data and resultant models provide new insights into the fundamental behavior of SCB detonators, particularly with respect to the initiation mechanism and the interaction of the explosive powder with the SCB. One model developed, the Thermal Feedback Model, considers the total energy budget for the system, including the time evolution of the energy delivered to the powder by the electrical circuit, as well as that released by the ignition and subsequent chemical reaction of the powder. The authors also present data obtained using a new low-voltage firing set which employed an advanced electrochemical capacitor having a nominal capacitance of 350,000 {micro}F at 9 V, the maximum voltage rating for this particular device. A model for this firing set and detonator was developed by making measurements of the intrinsic capacitance and equivalent series resistance (ESR < 10 m{Omega}) of a single device. This model was then used to predict the behavior of BNCP SCB detonators fired alone, as well as in a multishot, parallel-string configuration using a firing set composed of either a single 9 V electrochemical capacitor or two of the capacitors wired in series and charged to 18 V.

  1. Fast Hydrogen-Air Flames for Turbulence Driven Deflagration to Detonation Transition

    Science.gov (United States)

    Chambers, Jessica; Ahmed, Kareem

    2016-11-01

    Flame acceleration to Detonation produces several combustion modes as the Deflagration-to-Detonation Transition (DDT) is initiated, including fast deflagration, auto-ignition, and quasi-detonation. Shock flame interactions and turbulence levels in the reactant mixture drive rapid flame expansion, formation of a leading shockwave and post-shock conditions. An experimental study to characterize the developing shock and flame front behavior of propagating premixed hydrogen-air flames in a square channel is presented. To produce each flame regime, turbulence levels and flame propagation velocity are controlled using perforated plates in several configurations within the experimental facility. High speed optical diagnostics including Schlieren and Particle Image Velocimetry are used to capture the flow field. In-flow pressure measurements acquired post-shock, detail the dynamic changes that occur in the compressed gas directly ahead of the propagating flame. Emphasis on characterizing the turbulent post-shock environment of the various flame regimes helps identify the optimum conditions to initiate the DDT process. The study aims to further the understanding of complex physical mechanisms that drive transient flame conditions for detonation initiation. American Chemical Society.

  2. Study on the detonation properties of explosives in bore hole and precise controlled blasting; Happa konai no bakuyaku no bakugosei to seimitsu seigyo happa ni kansuru kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-10-08

    In order to perform efficient and safe controlled blasting, attaining sufficient detonation from explosive is important. Therefore, a mechanism of detonation in a bore hole was studied. Two detonation phenomenon measuring methods were established: one is a continuous detonation speed measuring method by using a resistance wire probe, and another is a detonation mark observing and evaluating method using aluminum and metallic lead plates. Assuming delay blastings in multiple bore holes used practically, discussions were given on detonation phenomena of explosives under pressurized condition. Under dynamic pressure condition, size of the pressurization and delay time of the detonations affected largely the detonation. Discussions were given on blasting effect and safety according to difference in forward initiation and reverse initiation. The reverse initiation method was verified to have excellent blasting effect, maintain good face conditions, and assure safety against inflammable gases. A precision initiation method was developed, which can control the initiation time of a detonator more precisely. The initiation accuracy is more than 1000 times greater than the ordinary instantaneously detonating electric detonator. The precision control of the initiation time proved to develop greater crack propagation. Vibration and stone scattering were also controlled. This paper also describes application of the method to a rock elastic wave exploration technique. 136 refs., 99 figs., 13 tabs.

  3. Development and application of theoretical models for Rotating Detonation Engine flowfields

    Science.gov (United States)

    Fievisohn, Robert

    As turbine and rocket engine technology matures, performance increases between successive generations of engine development are becoming smaller. One means of accomplishing significant gains in thermodynamic performance and power density is to use detonation-based heat release instead of deflagration. This work is focused on developing and applying theoretical models to aid in the design and understanding of Rotating Detonation Engines (RDEs). In an RDE, a detonation wave travels circumferentially along the bottom of an annular chamber where continuous injection of fresh reactants sustains the detonation wave. RDEs are currently being designed, tested, and studied as a viable option for developing a new generation of turbine and rocket engines that make use of detonation heat release. One of the main challenges in the development of RDEs is to understand the complex flowfield inside the annular chamber. While simplified models are desirable for obtaining timely performance estimates for design analysis, one-dimensional models may not be adequate as they do not provide flow structure information. In this work, a two-dimensional physics-based model is developed, which is capable of modeling the curved oblique shock wave, exit swirl, counter-flow, detonation inclination, and varying pressure along the inflow boundary. This is accomplished by using a combination of shock-expansion theory, Chapman-Jouguet detonation theory, the Method of Characteristics (MOC), and other compressible flow equations to create a shock-fitted numerical algorithm and generate an RDE flowfield. This novel approach provides a numerically efficient model that can provide performance estimates as well as details of the large-scale flow structures in seconds on a personal computer. Results from this model are validated against high-fidelity numerical simulations that may require a high-performance computing framework to provide similar performance estimates. This work provides a designer a new

  4. Detonation mode and frequency analysis under high loss conditions for stoichiometric propane-oxygen

    KAUST Repository

    Jackson, Scott

    2016-03-24

    The propagation characteristics of galloping detonations were quantified with a high-time-resolution velocity diagnostic. Combustion waves were initiated in 30-m lengths of 4.1-mm inner diameter transparent tubing filled with stoichiometric propane-oxygen mixtures. Chemiluminescence from the resulting waves was imaged to determine the luminous wave front position and velocity every 83.3 μ. As the mixture initial pressure was decreased from 20 to 7 kPa, the wave was observed to become increasingly unsteady and transition from steady detonation to a galloping detonation. While wave velocities averaged over the full tube length smoothly decreased with initial pressure down to half of the Chapman-Jouguet detonation velocity (DCJ) at the quenching limit, the actual propagation mechanism was seen to be a galloping wave with a cycle period of approximately 1.0 ms, corresponding to a cycle length of 1.3-2.0 m or 317-488 tube diameters depending on the average wave speed. The long test section length of 7300 tube diameters allowed observation of up to 20 galloping cycles, allowing for statistical analysis of the wave dynamics. In the galloping regime, a bimodal velocity distribution was observed with peaks centered near 0.4 DCJ and 0.95 DCJ. Decreasing initial pressure increasingly favored the low velocity mode. Galloping frequencies ranged from 0.8 to 1.0 kHz and were insensitive to initial mixture pressure. Wave deflagration-to-detonation transition and detonation failure trajectories were found to be repeatable in a given test and also across different initial mixture pressures. The temporal duration of wave dwell at the low and high velocity modes during galloping was also quantified. It was found that the mean wave dwell duration in the low velocity mode was a weak function of initial mixture pressure, while the mean dwell time in the high velocity mode depended exponentially on initial mixture pressure. Analysis of the velocity histories using dynamical systems ideas

  5. Performance and environmental impact assessment of pulse detonation based engine systems

    Science.gov (United States)

    Glaser, Aaron J.

    Experimental research was performed to investigate the feasibility of using pulse detonation based engine systems for practical aerospace applications. In order to carry out this work a new pulse detonation combustion research facility was developed at the University of Cincinnati. This research covered two broad areas of application interest. The first area is pure PDE applications where the detonation tube is used to generate an impulsive thrust directly. The second focus area is on pulse detonation based hybrid propulsion systems. Within each of these areas various studies were performed to quantify engine performance. Comparisons of the performance between detonation and conventional deflagration based engine cycles were made. Fundamental studies investigating detonation physics and flow dynamics were performed in order to gain physical insight into the observed performance trends. Experimental studies were performed on PDE-driven straight and diverging ejectors to determine the system performance. Ejector performance was quantified by thrust measurements made using a damped thrust stand. The effects of PDE operating parameters and ejector geometric parameters on thrust augmentation were investigated. For all cases tested, the maximum thrust augmentation is found to occur at a downstream ejector placement. The optimum ejector geometry was determined to have an overall length of LEJECT/DEJECT =5.61, including an intermediate-straight section length of LSTRT /DEJECT=2, and diverging exhaust section with 4 deg half-angle. A maximum thrust augmentation of 105% was observed while employing the optimized ejector geometry and operating the PDE at a fill-fraction of 0.6 and a frequency of 10 Hz. When operated at a fill-fraction of 1.0 and a frequency of 30 Hz, the thrust augmentation of the optimized PDE-driven ejector system was observed to be 71%. Static pressure was measured along the interior surface of the ejector, including the inlet and exhaust sections. The

  6. Genomic and Expression Profiling of Benign and Malignant Nerve Sheath Profiling of Benign and Malignant Nerve Sheath

    Science.gov (United States)

    2007-05-01

    Benign and Malignant Nerve Sheath Tumors in Neurofibromatosis Patients PRINCIPAL INVESTIGATOR: Matt van de Rijn, M.D., Ph.D. Torsten...Annual 3. DATES COVERED 1 May 2006 –30 Apr 2007 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER Genomic and Expression Profiling of Benign and Malignant Nerve...Award Number: DAMD17-03-1-0297 Title: Genomic and Expression Profiling of Benign and Malignant Nerve Sheath Tumors in Neurofibromatosis

  7. The influence of initial temperature on flame acceleration and deflagration-to-detonation transition

    International Nuclear Information System (INIS)

    Ciccarelli, G.; Boccio, J.L.; Ginsberg, T.

    1996-01-01

    The influence of initial mixture temperature on deflagration-to-detonation transition (DDT) has been investigated experimentally. The experiments were carried out in a 27-cm-inner diameter, 21.3-meter-long heated detonation tube, which was equipped with periodic orifice plates to promote flame acceleration. Hydrogen-air-steam mixtures were tested at a range of temperatures up to 650K and at an initial pressure of 0.1 MPa. In most cases, the limiting hydrogen mole fraction which resulted in transition to detonation corresponded to the mixture whose detonation cell size, λ, was approximately equal to the inner diameter of the orifice plate, d (e.g., d/λ∼1). The only exception was in dry hydrogen-air mixtures at 650K where the DDT limit was observed to be 11 percent hydrogen, corresponding to a value of d/λ equal to 5.5. For a 10.5 percent hydrogen mixture at 650K, the flame accelerated to a maximum velocity of about 120 m/s and then decelerated to below 2 m/s. This observation indicates that the d/λ = 1 DDT limit criterion provides a necessary condition but not a sufficient one for the onset of DDT in obstacle-laden ducts. In this particular case, the mixture initial condition (i.e., temperature) resulted in the inability of the mixture to sustain flame acceleration to the point where DDT could occur. It was also observed that the distance required for the flame to accelerate to the onset of detonation was a function of both the hydrogen mole fraction and the mixture initial temperature. For example, decreasing the hydrogen mole fraction or increasing the initial mixture temperature resulted in longer transition distances

  8. Critical deflagration waves leading to detonation onset under different boundary conditions

    International Nuclear Information System (INIS)

    Lin Wei; Zhou Jin; Lin Zhi-Yong; Fan Xiao-Hua

    2015-01-01

    High-speed turbulent critical deflagration waves before detonation onset in H 2 –air mixture propagated into a square cross section channel, which was assembled of optional rigid rough, rigid smooth, or flexible walls. The corresponding propagation characteristic and the influence of the wall boundaries on the propagation were investigated via high-speed shadowgraph and a high-frequency pressure sampling system. As a comprehensive supplement to the different walls effect investigation, the effect of porous absorbing walls on the detonation propagation was also investigated via smoke foils and the high-frequency pressure sampling system. Results are as follows. In the critical deflagration stage, the leading shock and the closely following turbulent flame front travel at a speed of nearly half the CJ detonation velocity. In the preheated zone, a zonary flame arises from the overlapping part of the boundary layer and the pressure waves, and then merges into the mainstream flame. Among these wall boundary conditions, the rigid rough wall plays a most positive role in the formation of the zonary flame and thus accelerates the transition of the deflagration to detonation (DDT), which is due to the boost of the boundary layer growth and the pressure wave reflection. Even though the flexible wall is not conducive to the pressure wave reflection, it brings out a faster boundary layer growth, which plays a more significant role in the zonary flame formation. Additionally, the porous absorbing wall absorbs the transverse wave and yields detonation decay and velocity deficit. After the absorbing wall, below some low initial pressure conditions, no re-initiation occurs and the deflagration propagates in critical deflagration for a relatively long distance. (paper)

  9. Management of benign prostatic hyperplasia with silodosin

    Directory of Open Access Journals (Sweden)

    Tomonori Yamanishi

    2009-08-01

    Full Text Available Tomonori Yamanishi1, Tomoya Mizuno1, Takao Kamai1, Ken-ichiro Yoshida1, Ryuji Sakakibara2, Tomoyuki Uchiyama31Department of Urology, Dokkyo Medical University, Tochigi, Japan; 2Department of Neurology, Sakura Hospital, Toho University, Toho, Japan; 3Department of Neurology, Chiba University, Chiba, JapanAbstract: It has been reported that blockade of α1A-adrenoceptor (AR relieves bladder outlet obstruction, while blockade of α1D-AR is believed to alleviate storage symptoms due to detrusor overactivity. Silodosin, (--1-(3-hydroxypropyl-5-[(2R-2-({2-[2-(2,2,2trifluoroethoxy phenoxy]ethyl}aminopropyl]-2,3-dihydro-1H-indole-7- carboxamide, is a new α1A-AR selective antagonist. Silodosin is highly selective for the α1A-AR subtype, showing an affinity for the α1A-AR that is 583- and 55.5-fold higher than its affinity for the α1B- and α1D-ARs, respectively. In randomized, double-blind, placebo-controlled phase III studies performed in Japan and the United States, silodosin has been shown to be effective for both storage and voiding symptoms associated with benign prostatic hyperplasia. Early effects of silodosin (after 2–6 hours or day 1 on lower urinary tract symptoms have also been reported. In urodynamic studies, detrusor overactivity disappeared in 40% and improved in 35% of patients after administration. In pressure flow studies, the grade of obstruction on the International Continence Society nomogram showed improvement in 56% of patients. The rate of adverse events in the silodosin, tamsulosin and placebo groups was 88.6%, 82.3%, and 71.6%, respectively. The most common adverse event was (mostly mild abnormal ejaculation (28.1%. However, few patients (2.8% discontinued silodosin because of abnormal ejaculation. Orthostatic hypotension showed a similar incidence in the silodosin (2.6% and placebo (1.5% groups. In conclusion, silodosin improves detrusor overactivity and obstruction and thus may be effective for both storage and voiding

  10. Advantages of robotics in benign gynecologic surgery.

    Science.gov (United States)

    Truong, Mireille; Kim, Jin Hee; Scheib, Stacey; Patzkowsky, Kristin

    2016-08-01

    The purpose of this article is to review the literature and discuss the advantages of robotics in benign gynecologic surgery. Minimally invasive surgery has become the preferred route over abdominal surgery. The laparoscopic or robotic approach is recommended when vaginal surgery is not feasible. Thus far, robotic gynecologic surgery data have demonstrated feasibility, safety, and equivalent clinical outcomes in comparison with laparoscopy and better clinical outcomes compared with laparotomy. Robotics was developed to overcome challenges of laparoscopy and has led to technological advantages such as improved ergonomics, visualization with three-dimensional capabilities, dexterity and range of motion with instrument articulation, and tremor filtration. To date, applications of robotics in benign gynecology include hysterectomy, myomectomy, endometriosis surgery, sacrocolpopexy, adnexal surgery, tubal reanastomosis, and cerclage. Though further data are needed, robotics may provide additional benefits over other approaches in the obese patient population and in higher complexity cases. Challenges that arose in the earlier adoption stage such as the steep learning curve, costs, and operative times are becoming more optimized with greater experience, with implementation of robotics in high-volume centers and with improved training of surgeons and robotic teams. Robotic laparoendoscopic single-site surgery, albeit still in its infancy where technical advantages compared with laparoscopic single-site surgery are still unclear, may provide a cost-reducing option compared with multiport robotics. The cost may even approach that of laparoscopy while still conferring similar perioperative outcomes. Advances in robotic technology such as the single-site platform and telesurgery, have the potential to revolutionize the field of minimally invasive gynecologic surgery. Higher quality evidence is needed to determine the advantages and disadvantages of robotic surgery in benign

  11. Comparison of detailed and reduced kinetics mechanisms of silane oxidation in the basis of detonation wave structure problem

    Science.gov (United States)

    Fedorov, A. V.; Tropin, D. A.; Fomin, P. A.

    2018-03-01

    The paper deals with the problem of the structure of detonation waves in the silane-air mixture within the framework of mathematical model of a nonequilibrium gas dynamics. Detailed kinetic scheme of silane oxidation as well as the newly developed reduced kinetic model of detonation combustion of silane are used. On its basis the detonation wave (DW) structure in stoichiometric silane - air mixture and dependences of Chapman-Jouguet parameters of mixture on stoichiometric ratio between the fuel (silane) and an oxidizer (air) were obtained.

  12. Shock-to-detonation transition of RDX, HMX and NTO based composite high explosives: experiments and modelling

    International Nuclear Information System (INIS)

    Baudin, G; Roudot, M; Genetier, M; Mateille, P; Lefrançois, A

    2014-01-01

    HMX, RDX and NTO based cast-cured plastic bounded explosive (PBX) are widely used in insensitive ammunitions. Designing modern warheads needs robust and reliable models to compute shock ignition and detonation propagation inside PBX. Comparing to a pressed PBX, a cast-cured PBX is not porous and the hot-spots are mainly located at the grain-binder interface leading to a different burning behavior during shock-to-detonation transition. Here, we review the shock-to-detonation transition (SDT) and its modeling for cast-cured PBX containing HMX, RDX and NTO. Future direction is given in conclusion.

  13. Shock-to-detonation transition of RDX, HMX and NTO based composite high explosives: experiments and modelling

    Science.gov (United States)

    Baudin, G.; Roudot, M.; Genetier, M.; Mateille, P.; Lefrançois, A.

    2014-05-01

    HMX, RDX and NTO based cast-cured plastic bounded explosive (PBX) are widely used in insensitive ammunitions. Designing modern warheads needs robust and reliable models to compute shock ignition and detonation propagation inside PBX. Comparing to a pressed PBX, a cast-cured PBX is not porous and the hot-spots are mainly located at the grain-binder interface leading to a different burning behavior during shock-to-detonation transition. Here, we review the shock-to-detonation transition (SDT) and its modeling for cast-cured PBX containing HMX, RDX and NTO. Future direction is given in conclusion.

  14. Combustion, detonation, shock waves. Proceedings of the Zel'dovich memorial - International conference on combustion. Volume 1

    International Nuclear Information System (INIS)

    Merzhanov, A.G.; Frolov, S.M.

    1995-01-01

    This book contains lectures by the experts in various fields of modern research in combustion, detonation and shock waves, presented at the Zel'dovich memorial - International conference on combustion dedicated to the 80-th birthday of academician Ya.B. Zel'dovich. There are eight chapters discussing the state-of-the-art in combustion kinetics, ignition and steady-state flame propagation, diffusion and heterogeneous combustion, turbulent combustion, unsteady combustion, detonation, combustion and detonation analogies, intense shock waves and extreme states of matter [ru

  15. Benign paroxysmal positional vertigo and comorbid conditions.

    Science.gov (United States)

    Cohen, Helen S; Kimball, Kay T; Stewart, Michael G

    2004-01-01

    To determine the prevalence of comorbid disease in patients with benign paroxysmal positional vertigo (BPPV) and the relationship of comorbid disease to symptoms of vertigo, disequilibrium, and anxiety. Patients who had posterior semicircular canal BPPV and who had been referred for vestibular rehabilitation at a tertiary care center completed a health status questionnaire and the Vertigo Symptom Scale, answered questions about level of vertigo, and were tested on computerized dynamic posturography. Subjects had high rates of diabetes, mild head trauma, and probable sinus disease. Balance was generally impaired, worse in diabetics and subjects with significant vestibular weakness. Subjects who smoked or had had mild head trauma had higher levels of anxiety. Comorbid conditions, particularly diabetes, mild head trauma, and sinus disease, are unusually prevalent in BPPV patients. Message: Patients with comorbid disease are at risk for having increased vertigo, anxiety, and disequilibrium compared to other patients. Copyright 2004 S. Karger AG, Basel

  16. Saw palmetto and benign prostatic hyperplasia.

    Science.gov (United States)

    Gong, Edward M; Gerber, Glenn S

    2004-01-01

    Benign prostatic hyperplasia (BPH) is a common health issue that affects 8% of all men at the age of 40, 60% of men in their 70s, and 90% of those greater than 80 years of age. One-fourth of these men will develop moderate to severe lower urinary tract symptoms that greatly affect their quality of life. Recent evidence suggests that the use of saw palmetto leads to improvements in urinary function for those suffering from BPH. The favorable comparison of saw palmetto with tamsulosin, a well-known first line agent in the treatment of urinary tract symptoms, demonstrates promise towards a beneficial effect of this herbal agent, with very few, if any, adverse effects. However, what degree of this beneficial activity is due to placebo effects is yet to be determined. In addition, the precise mechanism of action of saw palmetto in men with BPH remains unclear.

  17. A rare case of benign omentum teratoma

    Directory of Open Access Journals (Sweden)

    Sforza Marcos

    2012-01-01

    Full Text Available Introduction. Mature teratomas (benign cystic teratomas or dermoid cysts are among the most common ovarian tumours; however, teratomas of the omentum and mesentery are extremely rare. Teratoma in the intraperitoneal cavity is uncommon and atypical, and it is even more uncommon in adulthood. Case Outline. An 82-year-old female was admitted to our department with clinical signs of abdominal tumour. The ultrasound scan and preoperative laboratory tests were done. Explorative laparotomy revealed tumour with torsion on its pedicle at the greater omentum. After removal of the mass and the incision a tooth and hair were found, characteristics of teratoma. Conclusion. The excision was very effective and also definitive treatment for this case. The patient recovered well and was discharged 3 days later. The patient probably carried the tumour all her life asymptomatically until admission.

  18. The radiation therapy of benign diseases

    International Nuclear Information System (INIS)

    Hess, F.

    1980-01-01

    X-ray should only be applied when other forms of treatment of good-natured diseases do not provide equally good results. One should note that somatic lesion should be completely avoided and genetic lesion avoided to the greatest probability. One can distinguish according to ones aims between inflammation irradiation, pain irradiation, stimulation therapy and functional therapy. An indication for inflammation irradiation can be post-operative parotitis, furuncle in the face, mastitis puerperalis, panaritium ossale, recurrent sudoriparouns abscesses and repelling reactions after transplanting organs. Pain irradiation is indicated with degenerative diseases of the skeleton system. A further possible application is radiotherapy of hypotrophic processes and benign tumours. Functional radiotherapy is indicated with hyperendocrinism, neurovegetative disorders and allergies. (MG) [de

  19. Benign Duodenocolic Fistula: a Case Report.

    Science.gov (United States)

    Soheili, Marzieh; Honarmand, Shirin; Soleimani, Heshmatollah; Elyasi, Anvar

    2015-08-01

    Benign duodenocolic fistula (DCF), known as a fistula between the duodenum and colon with or without cecum of nonmalignant origin, is an unusual complication of different gastrointestinal diseases. The present paper records a case in which the patient presented with chronic diarrhea, abdominal pain, weight loss as well as having a history of gastric ulcer. Most frequently the condition presents with signs of malabsorption such as weight loss and diarrhea, but other symptoms include nausea, vomiting (sometimes with fecal), and abdominal pain. Gastrointestinal inflammatory conditions are the usual causes. The most common ones are perforated duodenal ulcer and Crohn's disease. Barium enemas are usually diagnostic. Treatment consists of excising the fistula and repairing the duodenal and colonic defects. Closure of the fistula provides quick relief.

  20. Benign Duodenocolic Fistula: a Case Report

    Directory of Open Access Journals (Sweden)

    Marzieh Soheili

    2015-10-01

    Full Text Available Benign duodenocolic fistula (DCF, known as a fistula between the duodenum and colon with orwithout cecum of nonmalignant origin, is an unusual complication of different gastrointestinal diseases. Thepresent paper records a case in which the patient presented with chronic diarrhea, abdominal pain, weight lossas well as having a history of gastric ulcer. Most frequently the condition presents with signs ofmalabsorption such as weight loss and diarrhea, but other symptoms include nausea, vomiting (sometimeswith fecal, and abdominal pain. Gastrointestinal inflammatory conditions are the usual causes. The mostcommon ones are perforated duodenal ulcer and Crohn’s disease. Barium enemas are usually diagnostic.Treatment consists of excising the fistula and repairing the duodenal and colonic defects. Closure of thefistula provides quick relief.

  1. Epidemiology of clinical benign prostatic hyperplasia

    Directory of Open Access Journals (Sweden)

    Kok Bin Lim

    2017-07-01

    Full Text Available Clinical benign prostatic hyperplasia (BPH is one of the most common diseases in ageing men and the most common cause of lower urinary tract symptoms (LUTS. The prevalence of BPH increases after the age of 40 years, with a prevalence of 8%–60% at age 90 years. Some data have suggested that there is decreased risk among the Asians compared to the western white population. Genetics, diet and life style may play a role here. Recent reports suggest the strong relationship of clinical BPH with metabolic syndrome and erectile dysfunction, as well as the possible role of inflammation as a cause of the prostatic hyperplasia. Lifestyle changes including exercise and diet are important strategies in controlling this common ailment.

  2. BENIGN PAROXYSMAL POSITIONAL VERTIGO- A PROSPECTIVE STUDY

    Directory of Open Access Journals (Sweden)

    Herman Guild Manayil John

    2017-03-01

    Full Text Available BACKGROUND Benign Paroxysmal Positional Vertigo (BPPV is one of the most common disorders of the vestibular system, which maybe unilateral or involve both labyrinths. It can be effectively treated by Canalith Repositioning Manoeuvers (CRM, but lack of awareness leads to delay in effective treatment. MATERIALS AND METHODS Study was conducted in a tertiary care center where 184 patients with BPPV were subjected to positional test and CRM. RESULTS M:F ratio was 1:2.1. 85% of BPPV patients were relieved of symptoms with one sitting of CRM. CONCLUSION CRM is very effective in treatment of BPPV. General practitioners and specialists should be more educated about this condition, which will reduce the delay in correct diagnosis and proper treatment.

  3. Environmentally benign chemical synthesis and processing

    International Nuclear Information System (INIS)

    Hancock, K.G.

    1992-01-01

    A new era of university-industry-government partnership is required to address the intertwined problems of industrial economic competitiveness and environmental quality. Chemicals that go up the stacks and down the drains are simultaneously a serious detriment to the environment, a waste of natural resources, and a threat to industrial profitability. Recently, the NSF Divisions of Chemistry and chemical and Thermal Systems have joined with the Council for Chemical research in a new grant program to reduce pollution at the source by underwriting research aimed at environmentally benign chemical synthesis and processing. Part of a broader NSF initiative on environmental science research, this new program serves as a model for university-industry-government joint action and technology transfer. Other features of this program and related activities will be described in this paper

  4. Benign meningiomas: primary treatment selection affects survival

    International Nuclear Information System (INIS)

    Condra, Kellie S.; Buatti, John M.; Mendenhall, William M.; Friedman, William A.; Marcus, Robert B.; Rhoton, Albert L.

    1997-01-01

    Purpose: To examine the effect of primary treatment selection on outcomes for benign intracranial meningiomas at the University of Florida. Methods and Materials: For 262 patients, the impact of age, Karnofsky performance status, pathologic features, tumor size, tumor location, and treatment modality on local control and cause-specific survival was analyzed (minimum potential follow-up, 2 years; median follow-up, 8.2 years). Extent of surgery was classified by Simpson grade. Treatment groups: surgery alone (n = 229), surgery and postoperative radiotherapy (RT) (n = 21), RT alone (n = 7), radiosurgery alone (n = 5). Survival analysis: Kaplan-Meier method with univariate and multivariate analysis. Results: At 15 years, local control was 76% after total excision (TE) and 87% after subtotal excision plus RT (SE+RT), both significantly better (p = 0.0001) than after SE alone (30%). Cause-specific survival at 15 years was reduced after treatment with SE alone (51%), compared with TE (88%) or SE+RT (86%) (p = 0.0003). Recurrence after primary treatment portended decreased survival, independent of initial treatment group or salvage treatment selection (p = 0.001). Atypical pathologic features predicted reduced 15-year local control (54 vs. 71%) and cause-specific survival rates (57 vs. 86%). Multivariate analysis for cause-specific survival revealed treatment group (SE vs. others; p = 0.0001), pathologic features (atypical vs. typical; p = 0.0056), and Karnofsky performance status (≥80 vs. <80; p = 0.0153) as significant variables. Conclusion: Benign meningiomas are well managed by TE or SE+RT. SE alone is inadequate therapy and adversely affects cause-specific survival. Atypical pathologic features predict a poorer outcome, suggesting possible benefit from more aggressive treatment. Because local recurrence portends lower survival rates, primary treatment choice is important

  5. Radiotherapy of benign diseases in Berlin (West)

    International Nuclear Information System (INIS)

    Saller, A.

    1979-01-01

    1. In Berlin (West), X-ray therapy was applied during the year 1973 in 18 hospitals and by 33 practicing physicians. The 3rd quarter of the year 1973 was taken as basis for the frequency of therapeutic X-ray application. From a total of 15912 patients, 9432 were X-rayed on account of malignant diseases, 6480 because of benigne diseases. This number definitely surpasses the number of cases treated in Munich by X-ray therapy. In Berlin, this might be connected to the age structure. 2. Utilizing the quotations and calculations put down in the report about the effect of atomic radiation by the Scientific Committee of the United Nations, and the values quoted for gonadal doses in the literature, a total-GSD-value of 0.82 +- 0.2 mrem/a was calculated for hospitals and practicing physicians in Berlin. In spite of higher frequencies, this value is approximately of the same order of magnitude as the values calculated for Munich for the year 1971 by I. and H.P. Schmelz. 3. The total-GSD-value for the population of the Federal Republic of Germany resulting from artificial radiation exposure during 1976 is reported to be approximately 60 mrem. Thus, the GSD-value for the X-ray therapy of benign diseases lies approximately at 1.3% and should be of minor significance for radiation-hygienic reflections. 4. Of primary concern is still the radiation exposure to individual patients. Because of possible secondary effects, X-ray therapy for keloids and hemangiomas in infancy and youth are of particular significance. For this reason, its proportion to GSD is also in Berlin relatively large. (orig.) [de

  6. Single benign metastasising leiomyoma of an inguinal lymph node.

    NARCIS (Netherlands)

    Laban, KG; Tobon-Morales, Roberto; Hodge, Janice; Schreuder, HWR

    2016-01-01

    Benign metastasising leiomyoma (BML) is a rare benign disease associated with uterine leiomyoma and history of uterine surgery. It most frequently occurs in premenopausal woman, with a pulmonary localisation, and consisting of multiple nodules. We present an uncommon case of a 69-year-old woman with

  7. Case report 525: Benign fibrous histiocytoma (BFH) of thumb

    International Nuclear Information System (INIS)

    Statz, E.M.; Philipps, E.; Pochebit, S.M.; Cooper, A.; Leslie, B.M.

    1989-01-01

    A case was presented of benign fibrous histiocytoma (BFH) involving the distal phalanx of the thumb, a location heretofore not described in the literature. The distinction between BFH and other lesions (e.g. non-ossifying fibroma) was considered in depth. The distinction between benign and malignant fibrous histiocytoma was also described. (orig.)

  8. Benign Strictures of the Esophagus and Gastric Outlet: Interventional Management

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jin Hyoung; Shin, Ji Hoon; Song, Ho Young [University of Ulsan College of Medicine, Asan Medical Center, Seoul (Korea, Republic of)

    2010-10-15

    Benign strictures of the esophagus and gastric outlet are difficult to manage conservatively and they usually require intervention to relieve dysphagia or to treat the stricture-related complications. In this article, authors review the non-surgical options that are used to treat benign strictures of the esophagus and gastric outlet, including balloon dilation, temporary stent placement, intralesional steroid injection and incisional therapy

  9. A contrast-enhanced ultrasound study of benign and malignant ...

    African Journals Online (AJOL)

    A contrast-enhanced ultrasound study of benign and malignant breast tissue. S Barnard, E Leen, T Cooke, W Angerson. Abstract. Objective. To determine the diagnostic value of haemodynamic contrast-enhanced ultrasound assessment in benign and malignant breast tissue, using histological examination as the reference ...

  10. Benign hepatic portal venous gas following caustic ingestion

    International Nuclear Information System (INIS)

    Lewin, Maite; Tubiana, Jean-Michel; Pocard, Marc; Caplin, Scott; Parc, Rolland; Blain, Antoine

    2002-01-01

    Hepatic portal vein gas has been documented in numerous conditions and is traditionally regarded as a poor prognostic sign. There are, however, several reports of portal vein gas with a benign course. We report the first case of transient hepatic portal vein gas secondary to the ingestion of a caustic substance. The literature of hepatic portal vein gas in benign disease is reviewed. (orig.)

  11. The ABC of benign breast disease | Ndhluni | Continuing Medical ...

    African Journals Online (AJOL)

    Benign breast disease is common, although the incidence is sparsely documented in the literature and is probably quite underestimated. The main reason is that it is regarded as unimportant, with far more attention being focused on breast cancer. However, benign breast disease is far more common than breast cancer.

  12. Large mid-esophageal granular cell tumor: benign versus malignant

    Directory of Open Access Journals (Sweden)

    Prarthana Roselil Christopher

    2015-06-01

    Full Text Available Granular cell tumors are rare soft tissue neoplasms, among which only 2% are malignant, arising from nervous tissue. Here we present a case of a large esophageal granular cell tumor with benign histopathological features which metastasized to the liver, but showing on positron emission tomography-computerized tomography standardized uptake value suggestive of a benign lesion.

  13. Perfusion MR imaging for differentiation of benign and malignant meningiomas

    NARCIS (Netherlands)

    Zhang, Hao; Rodiger, Lars A.; Shen, Tianzhen; Miao, Jingtao; Oudkerk, Matthijs

    Introduction Our purpose was to determine whether perfusion MR imaging can be used to differentiate benign and malignant meningiomas on the basis of the differences in perfusion of tumor parenchyma and/or peritumoral edema. Methods A total of 33 patients with preoperative meningiomas (25 benign and

  14. Benign breast lesions in Kano | Ochicha | Nigerian Journal of ...

    African Journals Online (AJOL)

    Results: Benign breast lesions accounted for 160 (73%) of all breast biopsies seen, and 71.9% of breast diseases in women with a benign to malignant ratio of 2.6 to 1. The mean age at presentation was 26 years. Fibrocystic disease was the commonest histological lesion comprising 55 (34.3%) of all cases, with a mean ...

  15. Case Report: Giant Benign Prostatic Hyperplasia in a Ghanaian ...

    African Journals Online (AJOL)

    Giant Benign Prostatic Hyperplasia (GBPH) is an uncommon pathology of the prostate gland. Up to date, only 17 cases have been described with specimen weights exceeding 500 g in the world literature. We report the successful removal of the largest ever benign prostatic hyperplasia (800 g) via transvesical prostatectomy ...

  16. Nerve Invasion by Epithelial Cells in Benign Breast Diseases

    Directory of Open Access Journals (Sweden)

    Yu-Jan Chan

    2009-03-01

    Full Text Available Nerve invasion by glandular epithelial cells in a lesion is usually regarded as invasive carcinoma. However, some benign conditions in the pancreas, prostate, breast and other organs may show involvement of nerve bundles by benign epithelial cells. We report an 18-year-old female with nerve invasion in benign breast disease. The lesion in her right breast revealed fibrocystic changes with ductal hyperplasia and stromal sclerosis. Perineural and intraneural involvement by bland-looking small ducts lined by 2 layers of cells including an outer layer of myoepithelial cells were found, suggestive of benign nerve invasion. There was no evidence of malignant cells in any of the sections. The patient remains well after 31 months of follow-up. About 44 cases of nerve invasion in benign breast diseases have been reported in the literature. It is necessary to carefully evaluate nerve involvement in breast lesions to avoid over-diagnosis and inappropriate operation.

  17. Modern role and issues of radiation therapy for benign diseases

    International Nuclear Information System (INIS)

    Miyashita, Tsuguhiro; Tateno, Atsushi; Kumazaki, Tatsuo

    1999-01-01

    Cases of radiation therapy for benign diseases have diminished in number because of recent alternative methods and knowledge about radiation carcinogenesis. In contrast to this tendency, our cases of benign diseases have recently increased. The facts made us reconsider today's radiation therapy of benign diseases. We reviewed 349 patients who were diagnosed as having benign tumors or non-neoplastic conditions and treated by radiation therapy in the past sixteen years. Analyzed items were the annual transition of treatment number, sorts of diseases, patients' age and sex, and the goal of therapy. Of all radiation therapy patients, benign diseases account for 9.26%. The annual percentages were 0.5%, 6.0%, 11.2% and 13.7% at intervals of five years since 1982. The majority was 246 post-operative irradiation for keloids (71%) and 41 pituitary adenomas (12%). Compared with malignant tumors, benign disease patients were statistically younger and female-dominant. Applications of radiation therapy in keloids and pituitary adenomas had definite goals, but were unclear in other rare diseases. Benign diseases should be treated by radiation therapy as the second or third option, provided the patients have serious symptoms and their diseases do not respond to other modalities. It seems to be widely accepted that favorite cases such as keloids and pituitary adenomas are treated by radiation therapy. But, optimal radiation therapies for other rare benign diseases have not been established. Therefore, the building of databases on radiation therapy on benign diseases should be pursued. Since benign disease patients were young and female-dominant and had many remaining years, their carcinogenicity potential should be considered. (author)

  18. Numerical Study of Detonation Wave Propagation in the Variable Cross-Section Channel Using Unstructured Computational Grids

    Directory of Open Access Journals (Sweden)

    Alexander Lopato

    2018-01-01

    Full Text Available The work is dedicated to the numerical study of detonation wave initiation and propagation in the variable cross-section axisymmetric channel filled with the model hydrogen-air mixture. The channel models the large-scale device for the utilization of worn-out tires. Mathematical model is based on two-dimensional axisymmetric Euler equations supplemented by global chemical kinetics model. The finite volume computational algorithm of the second approximation order for the calculation of two-dimensional flows with detonation waves on fully unstructured grids with triangular cells is developed. Three geometrical configurations of the channel are investigated, each with its own degree of the divergence of the conical part of the channel from the point of view of the pressure from the detonation wave on the end wall of the channel. The problem in consideration relates to the problem of waste recycling in the devices based on the detonation combustion of the fuel.

  19. GIS surface effects archive of underground nuclear detonations conducted at Yucca Flat and Pahute Mesa, Nevada Test Site, Nevada

    International Nuclear Information System (INIS)

    Grasso, D.N.

    2001-01-01

    This report presents a new comprehensive, digital archive of more than 40 years of geologic surface effects maps produced at individual detonation sites throughout the Yucca Flat and Pahute Mesa nuclear testing areas of the Nevada Test Site, Nye County, Nevada. The Geographic Information System (GIS) surface effects map archive on CD-ROM (this report) comprehensively documents the surface effects of underground nuclear detonations conducted at two of the most extensively used testing areas of the Nevada Test Site. Between 1951 and 1992, numerous investigators of the U.S. Geological Survey, the Los Alamos National Laboratory, the Lawrence Livermore National Laboratory, and the Defense Threat Reduction Agency meticulously mapped the surface effects caused by underground nuclear testing. Their work documented the effects of more than seventy percent of the underground nuclear detonations conducted at Yucca Flat and all of the underground nuclear detonations conducted at Pahute Mesa

  20. SLAG CHARACTERIZATION AND REMOVAL USING PULSE DETONATION TECHNOLOGY DURING COAL GASIFICATION

    Energy Technology Data Exchange (ETDEWEB)

    DR. DANIEL MEI; DR. JIANREN ZHOU; DR. PAUL O. BINEY; DR. ZIAUL HUQUE

    1998-07-30

    Pulse detonation technology for the purpose of removing slag and fouling deposits in coal-fired utility power plant boilers offers great potential. Conventional slag removal methods including soot blowers and water lances have great difficulties in removing slags especially from the down stream areas of utility power plant boilers. The detonation wave technique, based on high impact velocity with sufficient energy and thermal shock on the slag deposited on gas contact surfaces offers a convenient, inexpensive, yet efficient and effective way to supplement existing slag removal methods. A slight increase in the boiler efficiency, due to more effective ash/deposit removal and corresponding reduction in plant maintenance downtime and increased heat transfer efficiency, will save millions of dollars in operational costs. Reductions in toxic emissions will also be accomplished due to reduction in coal usage. Detonation waves have been demonstrated experimentally to have exceptionally high shearing capability, important to the task of removing slag and fouling deposits. The experimental results describe the parametric study of the input parameters in removing the different types of slag and operating condition. The experimental results show that both the single and multi shot detonation waves have high potential in effectively removing slag deposit from boiler heat transfer surfaces. The results obtained are encouraging and satisfactory. A good indication has also been obtained from the agreement with the preliminary computational fluid dynamics analysis that the wave impacts are more effective in removing slag deposits from tube bundles rather than single tube. This report presents results obtained in effectively removing three different types of slag (economizer, reheater, and air-heater) t a distance of up to 20 cm from the exit of the detonation tube. The experimental results show that the softer slags can be removed more easily. Also closer the slag to the exit of